description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
This Application is a Continuation-In-Part of prior application U.S. Ser. No. 09/514,089, filed Feb. 28, 2000, now U.S. Pat. No. 6,196,697, which is a CIP of Ser. No. 09/118,980 filed Jul. 10, 1998 U.S. Pat. No. 6,033,083, which is a CIP of Ser. No. 08/687,809 Jul. 26, 1996 U.S. Pat. No. 5,779,349.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to airport runway light support apparatus and methods. In one aspect, this invention relates to height and azimuth adjustable container apparatus and methods for embedded container light supports for airport runways and the alignment of their light fixtures. In one aspect, this invention relates to adjustable airport runway lights and to apparatus and methods for specialized, set-in-the-ground lighting systems utilized for the purpose of guiding pilots during their approach to an airport runway and during the landing and taxi of aircraft.
2. Background
Conventional lighting fixtures forming part of specialized, set-in-the-ground airport runway lighting systems are mounted on certain steel containers. The steel containers for these airport runway inset lights can be one-part or two-part and, sometimes, three-part containers and are set below the surface of runways, taxiways, and other aircraft ground traffic areas. The bottom sections of the containers are sometimes called shallow light bases. The top sections are called fixed-length extensions and are manufactured in different fixed lengths and diameters. Flat spacer rings are installed between the extensions and the lighting fixtures for providing further height and azimuth adjustments. These conventional steel containers, in addition to serving as bases for mounting the lighting fixtures, also serve as transformer housings and junction boxes to bring electrical power to the lighting fixtures.
In the installation of airport runway touchdown zone, centerline, and edge lighting systems, as well as in the construction or installation of taxiway centerline and edge lighting systems, and other lighting systems, these containers are embedded in the runway, taxiway, and other pavements at the time the runway and taxiway pavements are poured (concrete) or placed (bituminous). These containers, hereinafter referred to as embedded containers, vary in length and diameter. Conventional embedded containers provide an inverted flange at their top portion, which flange has a standard set of threaded holes to allow for the runway, taxiway, edge, and other light fixtures to be bolted onto them above the pavement surface, or to allow for the top section of the container to be bolted onto the bottom section, if it is a two-section container. A great majority of these existing, conventional containers are two section containers, bolted together at their inverted flanges. The light fixture then is bolted onto the top inverted flange of the top section of the two-section container. The top section of the two-section container is referred to as the fixed-length extension, which is part of the conventional embedded containers.
The top portions of the lighting fixtures are installed at a close tolerance, slightly above the pavement surface. Installations of the containers and their lighting fixtures are required on two different occasions. The first is when the runways, taxiways, and other aircraft ground traffic areas are built for the first time. The second is for resurfacing or repaving of the runways, taxiways, and other aircraft ground traffic areas. The latter is the most common, i.e., most frequent.
The light fixtures installed on the embedded containers, otherwise known as airport inset lights, have to be aligned with respect to each other in a precise, straight line on the horizontal plane known as azimuth correction, and their height has to be set within a fixed, strict tolerance measured from the pavement surface.
Each airport paving project may consist of installing hundreds or thousands of lighting fixtures and their airport inset light containers.
Runways, taxiways, and other aircraft ground traffic areas deteriorate with years of usage. This creates the need for resurfacing or repaving, i.e., replacing the asphalt of these ground surfaces. Repavement is a much more common, i.e., frequent, occurrence than the construction of new pavements.
When a runway, taxiway, or other aircraft ground traffic area is first built, or when upgrading or modernizing, or when maintenance projects require their resurfacing (repavement), the flanges on the embedded containers get buried under the pavement. This creates the need for height adjusting devices with flanges identical to those of the embedded containers to adapt the container up to the final surface and for the lighting fixtures to be installed and aligned above the payment. In many instances, this requires core-drilling the newly poured or placed pavement to reach down to the now buried top flange of the embedded container.
Depending on the lengths of the runways and taxiways, thousands of these embedded containers are affected, and a wide variety of height adjustments can be involved for each given size of embedded containers. In such an adjustment system, fixed-length extensions must be made available in many different lengths, so as to provide the many different gross height adjustments. A combination of one or more flat spacer rings, which are manufactured in thicknesses of {fraction (1/16)}, ⅛, ¼, and ½ inch (1.6, 5 3.2, 6.3, and 12.7 millimeters, approximately), and other thicknesses, can be used to provide the final height.
These fixed-length extensions have one inverted flange on each end to bolt onto the embedded container, and then flat rings are added on top of the fixed-length extension top flange before the lighting fixture is bolted onto the flange.
The fixed-length extensions and the flat spacer rings must be individually ordered to the required length. This adjustment system makes for a difficult and tedious conventional installation procedure involving (1) field measurement of each individual fixed extension length and flat spacer ring required for every container; (2) record keeping of all those field measurements and locations for ordering and verification; (3) ordering, receiving, and delivering to the field each size according to its location; and (4) frequently having to install more than one flat spacer ring to achieve the required height. The listed complications for the difficult conventional installation procedure are further magnified by the fact that the embedded containers are made in 4 different sizes: 10, 12, 15, and 16 inches (25.4, 30.5, 38.1, and 40.6 centimeters, approximately) in diameter.
These embedded containers below the pavement surface serve as light fixture bases. They also serve as transformer housings and junction boxes.
INTRODUCTION TO THE INVENTION
Depending on the location where these containers are installed, they are exposed to varying degrees and types of corrosive chemicals and materials applied to them by the aircraft and other vehicular traffic in that location. For example, runway and taxiway light fixtures, and the containers they are bolted onto, are subjected to rain water and to chemicals such as chemicals applied to the aircraft for the purpose of deicing.
It is therefore an object of the present invention to provide non-corrosive apparatus and method for mounting an airport runway light and adjusting with precision and simplicity the height and the azimuth of a runway embedded container and for aligning with efficiency, simplicity, and precision a lighting fixture installed upon the non-corrosive apparatus of the present invention.
A further object of the present invention is to provide non-corrosive apparatus and method for adjusting the height of a runway embedded container without having to install individual fixed-length extensions or flat spacer rings.
A still further object of the present invention is to provide non-corrosive apparatus and method for adjusting the height and azimuth of an array of airport runway embedded containers in a lighting system without having to install individual fixed-length extensions or flat spacer rings.
It is an object of the present invention to provide non-corrosive apparatus and method for adjusting with precision and simplicity the height and the azimuth of a container, previously installed and embedded as an airport inset light, and for aligning with efficiency, simplicity, and precision a lighting fixture installed upon the apparatus of the present invention.
It is a further object of the present invention to provide an alignment adjustments assembly that does not require the installation of a separate mud dam.
It is a further object of the present invention to provide a non-corrosive alignment adjustments assembly that does not require the installation of a separate mud dam.
A further object of the present invention is to provide non-corrosive apparatus and method for adjusting the height of a container, previously installed and embedded as an airport inset light, without having to install individual fixed-length extensions or flat spacer rings.
A still further object of the present invention is to provide non-corrosive apparatus and method for adjusting the height and azimuth of an array of containers, previously installed and embedded as airport inset lights, in a lighting system without having to install individual fixed-length extensions or flat spacer rings.
It is an object of the present invention to provide a non-corrosive alignment adjustments assembly which corrects the problem of tilting of the assembly from the vertical axis which increases the angle at which the light beam from an inset lighting fixture is projected, diverting the light beam away from incoming airplanes.
It is also another object of this invention to provide a non-corrosive alignments adjustments assembly which corrects the problem of the rotation of the assembly which alters the azimuth alignment of the lighting fixture, which in turn would impede the pilot of an incoming airplane from seeing the light.
It is yet another object of the present invention to provide a non-corrosive alignments adjustments assembly which will allow the longer, angled bottom type inset lights be installed upon it.
It is yet a further object of the present invention to provide a non-corrosive alignment adjustments assembly which does not require installing a separate flat spacer ring, with a groove on its top flat side.
These and other objects of the present invention will become apparent from a careful review of the detailed description and the figures of the drawings which follow.
SUMMARY OF THE INVENTION
Novel non-corrosive airport inset light adjustable alignment container set apparatus and method of the present invention include a light fixture and stainless steel support for airport runway, taxiway, or other aircraft ground traffic areas. A variable length means rotatably adjusts height by a vertical displacement and mounting means for mounting the airport inset light. Rotation locking means are provided for securing the rotatable adjustment apparatus from further rotation. A top flange is adapted to receive various different designs of inset lights and to provide a stainless steel protection ring “mud dam.”
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view, partially in section, of the existing fixed-length extensions installed on an embedded container and a lighting fixture installed thereon. FIG. 1 also shows a concrete encasement and three layers of pavement.
FIG. 2 is an elevation view, partially in section, of the same existing fixed-length extensions of FIG. 1 but now shown tilted.
FIG. 3 is a pictographic view, partially in section, showing a landing passenger jet airplane, a runway, and a tilted runway centerline inset lighting fixture.
FIG. 4 is an elevation view, partially in section, of the adjustable extension component of the present invention showing a mud dam and an “O” ring with its groove.
FIG. 5 is an elevation view, partially in section, showing an Allen-set screw component of the present invention.
FIG. 6 is an elevation view, partially in section, of the adapter flange component of the present invention.
FIG. 7 is an elevation view, partially in section, of an airport inset lighting fixture, showing a straight bottom.
FIG. 8 is an elevation view, partially in section, of an airport inset lighting fixture, showing an angled bottom.
FIG. 9 is a plan view of the lighting fixture of FIG. 7 and of FIG. 8 .
FIG. 10 is an elevation view, partially in section, of a mud dam protection ring.
FIG. 11 is an elevation view, partially in section, of the alignments adjustments assembly of the present invention shown installed on an existing embedded container. FIG. 11 also shows an airport inset lighting fixture mounted on the adjustments assembly.
FIG. 12 is a plan view of the top flange of the embedded container of FIGS. 1, 2 , and 11 .
FIG. 13 is an elevation view, partially in section, of the universal top adjustment container of the present invention and shows an airport inset lighting fixture and an “O” ring.
FIG. 14 is a plan view, i.e., a top view, of the universal top adjustment container of the present invention as shown in FIG. 13 without the lighting fixture.
DETAILED DESCRIPTION
The present invention provides a height and azimuth adjustable container set, utilized for all the purposes embedded containers are utilized, i.e., to serve as bases for lighting fixtures, as transformer housings, and as junction boxes, but with a major difference from conventional embedded containers. The adjustable container sets of the present invention also are utilized for the precise and simplified, economic mounting and adjusting of the height of the lighting fixture to be mounted upon it. Also, the adjustable containers of the present invention provide for precise and simplified, economic aligning of the azimuth of the lighting fixtures and aligning the lights with respect to each other, by virtue of the azimuth alignment.
The adjustable container set of the present invention is used to improve existing containers, while being efficiently and economically adjustable. These containers are installed in airport runways, taxiways, and other aircraft ground traffic areas to serve as bases for lighting fixtures, transformer housings, and junction boxes. The adjustments take place when the containers and their lighting fixtures are installed initially, e.g., when new runway, taxiway, and other aircraft ground traffic areas are first built and every time they are repaved.
The present invention provides a height and azimuth alignments adjustments assembly utilized for the more economic, precise, and simplified adjusting of the heights of concrete embedded containers and the azimuth alignment of airport inset lighting fixtures mounted thereon. These containers of the present invention are installed and reused in airport runways and taxiways and other aircraft ground traffic areas to serve as bases for lighting fixtures, transformer housings, and as junction boxes.
In the actual testings and installations of the alignments adjustments assembly disclosed and described in U.S. patent application Ser. No. 08/002,014 filed Jan. 8, 1993 and entitled “Alignments Adjustments Assembly Apparatus and Method,” now U.S. Pat. No. 5,541,362, I have discovered certain aspects which could be modified.
One drawback is that airport runway light bolts used to install the airport runway light on or in the airport runway light support can be part of a corrosion problem. Corrosive materials such as deicing chemicals used on the aircraft can accelerate corrosive problems between the light bolts and the light support. The airport runway light stainless steel bolts can accelerate corrosive attack by a galvanic action between dissimilar metals.
The present invention provides an alignment adjustments assembly which corrects the problem of corrosion.
One drawback is that a great number of the existing conventional, fixed-length extensions installed as stacked-on embedded containers have tilted from their vertical axis. This tilting, which at the place of tilting is relatively small, nevertheless increases the angle at which the light beam from an inset lighting fixture is projected, thereby diverting the light beam away from incoming airplanes. At one-half mile (1 kilometer) away from the approach area, it is difficult for the pilot of a landing airplane to see the light because of the very large divergence at that point from the point at which it should otherwise be, when properly height-adjusted.
The present invention provides an alignment adjustments assembly which corrects the problem of tilting.
Another drawback encountered is that the new larger and heavier airplanes, now becoming more common, exert a larger torsional force upon the inset lighting fixtures. Tests made to simulate those larger torsional forces on the alignment adjustment assembly disclosed and described in U.S. patent application Ser. No. filed Jan. 8, 1993 and entitled “Alignments Adjustments Assembly Apparatus and Method,” now U.S. Pat. No. 5,541,362, proved that a very slight rotational movement occurs, even though considered relatively insignificant today. Nevertheless, even heavier airplanes could provide a more significant rotational movement that would alter the azimuth alignment of the lighting fixture, which in turn would impede the pilot of an incoming airplane from seeing the light.
The present invention provides an alignments adjustments assembly which corrects the problem of the rotation of the assembly.
Yet another drawback encountered is the need to install a separate component called the mud dam, consisting of a flat, three-quarters inch (19 mm) thick spacer ring with a flat, thin steel band welded all around the periphery of the flat spacer ring. This band is about one and a quarter inches (3.3 cm) wide.
The present invention provides an alignment adjustments assembly that does not require the installation of a separate mud dam.
A further drawback encountered is that there are two types of inset light construction with respect to its bottom side. The bottom on one type is short and flat. The bottom on the other is longer and at an angle with respect to the light base vertical axis. The longer, angled bottom does not allow the light to fit properly on the top flange of the apparatus as disclosed and described in U.S. patent application Ser. No. 08/002,014 filed Jan. 8, 1993 and entitled “Alignments Adjustments Assembly Apparatus and Method,” now U.S. Pat. No. 5,541,362.
The present invention provides an alignments adjustments assembly which will allow the longer, angled bottom type inset lights to be installed upon it.
Yet a further drawback encountered is that, in a great many occasions, an “O” ring seal is specified. In such cases, a separate flat, three-quarters inch (19 mm) thick spacer ring, with a groove on its top flat side, is installed between the fixed-length extension and the lighting fixture.
The present invention provides an alignment adjustments assembly which does not require installing a separate flat spacer ring with a groove on its top flat side.
The invention includes an existing embedded container with an inverted flange on one end onto which an adapter flange bolts. The adapter flange has Acme threads in its center aperture. The apparatus and method of the present invention also include an outside Acme threaded adjustable extension, which threads down into the adapter flange, to provide the precise height required and the precise alignment of its lighting fixture. The adjustable height extension has a top flange to provide a base upon which the specified lighting fixture can be bolted.
The present invention provides height and azimuth light support sets utilized for the more efficient and economic, precise, and simplified adjusting of the heights of exiting art embedded containers and the alignment of their light fixtures. These containers are installed in airport runways and taxiways to serve as bases for lighting fixtures, as transformer housings, and as junction boxes.
Referring now to FIGS. 1 and 2, a container 1 is represented schematically with three fixed-length extensions 2 , 7 , and 11 bolted together. Container 1 is embedded in concrete 25 at the time an airport runway, taxiway, and other aircraft ground traffic areas (hereinafter aircraft ground traffic areas) are first built. These ground traffic areas generally are built upon a compacted granular sub-base 26 .
Steel containers 1 , in addition to serving as bases for mounting airport inset lighting fixtures 95 also serve as transformer housings and junction boxes to bring electrical power to lighting fixture 95 , as shown in FIGS. 1, 2 , and 7 . Fixed-length extension 2 is bolted to top flange 30 on container 1 , which has 12 threaded bolt holes 136 , as shown in FIG. 12, by means of its bottom flange 4 and bolts 3 . Fixed-length extension 2 is bolted to bottom flange 6 of fixed-length extension 7 by means of its top flange 5 and bolts 8 . Fixed-length extension 7 is bolted on top of fixed-length extension 2 .
Fixed-length extensions have twelve bolt holes in both of their flanges, i.e., top flange 5 and bottom flange 4 of extension 2 , as shown in FIG. 1 . The bolt holes, not shown, on the top flanges of the extensions are threaded, while the bolt holes, not shown, on the bottom flange are not threaded. Nevertheless, the bolt holes in both flanges of the fixed-length extensions are on a bolt hole circle diameter identical to bolt circle diameter 137 , as shown in FIG. 12, of container 1 .
Fixed-length extension 7 is bolted to bottom flange 10 of fixed-length extension 11 by means of its top flange 9 and bolts 12 . Fixed-length extension 11 is bolted on top of fixed-length extension 7 .
Fixed-length extensions provide only a gross height adjustment. One or a plurality of flat spacer rings 15 are required for providing the more precise final height adjustment.
Flat spacer rings 15 are installed on top flange 13 of fixed-length extension 11 , as shown in FIG. 1, i.e., the top fixed-length extension, to provide the final height adjustment 17 for inset lighting fixture 95 . Flat spacer rings 15 can be one or more. They are fabricated as thin as {fraction (1/16)} inch (1.6 mm) and as thick as three-quarters inch (19 mm) or thicker. Mud dam 36 , as shown in FIGS. 1 and 10, comes next on top of spacer rings 15 . The inset lighting fixture 95 is bolted together with flat spacer rings 15 and mud dam 36 onto the top flange 13 of the top fixed-length extension 11 by means of bolts 14 .
Continuing to refer to FIGS. 1 and 2, several layers of pavement 19 , 20 , 21 are shown, to exemplify the fact that fixed-length extensions 2 , 7 , and 11 are utilized for height adjustments every time an aircraft ground traffic area is first built or upgraded by the installation of new pavement, i.e., each new layer of pavement 19 , 20 , and 21 . The new layers create new surfaces 22 , 23 , and 24 and therefore new heights.
These airport aircraft ground traffic area upgrades create the need for heights adjusting devices, with flanges identical to those of the embedded container 1 , in order to adapt the container 1 to the new surface, i.e., the new height and further in order for the lighting fixture 95 to be installed slightly above the new pavement surface, i.e., surface 22 , 23 , or 24 , at a close tolerance 17 above new pavement surface 24 , for example.
In order to seal pavement layers 19 , 20 , 21 around container 1 , grout 18 is utilized. Pavement rings 36 , commonly known in the industry as mud dam 36 , as shown in FIGS. 1 and 10, are installed on top of spacer rings 15 to protect lighting fixture 95 from being splashed by the grout 18 at the time of its application.
Inset lighting fixture 95 is set inside mud dam protection ring 36 , as shown in FIG. 10 . Mud dam 36 consists of a flat ring 38 , as shown in FIG. 10, generally of ¾ inch (19 mm) in thickness, with a 1 to 1¼ inch (2.54 to 3.27 cm) wide, flat, thin steel band welded around the periphery of flat ring 38 . Flat ring 38 has bolt holes 39 which match bolt holes, not shown, on flat spacer rings 15 , on fixed-length extension 11 as well as on lighting fixture 95 . Bolt holes on fixed-length extension 11 are threaded. Lighting fixture 95 is bolted onto fixed-length extension 11 , together with mud dam 36 and flat spacer rings 15 by means of bolts 14 . Mud dams 36 are generally provided with grooves 43 in order to accept “O”-ring gasket 44 .
When any one layer of pavement is first placed, it is done by placing it over the entire surface, i.e., surface 31 . Then the pavement 19 is core-drilled at the location of each container 1 to remove the pavement at that location to install fixed-length extension 2 , any flat spacer ring 15 , mud dam 36 , and finally lighting fixture 95 at the new height created by pavement 19 and surface 22 , by way of example. This process is repeated every time a new layer of pavement is added, i.e., for further layers 20 and 21 . The core drilled hole is larger in diameter than the diameter of container 1 , hence the requirement to utilize grout 18 to fill in the void and therefore the need to install a mud dam 36 , as shown in FIG. 10, to protect lighting fixture 95 , as shown in FIGS. 1, 2 when grout 18 is poured.
A new method has been used for a few years already, whenever an aircraft ground traffic area reconstruction takes place, i.e., resurfacing or repaving. Instead of adding a new layer of pavement on top of the last one installed, the last one layer, i.e., pavement layer 21 , is milled down by large roto-milling machines. This method is extensively explained in my U.S. Pat. No. 5,431,510 entitled “Overlay Protection Plate Apparatus and Method.”
Prior to roto-milling the pavement top layer, i.e., layer 21 , the lighting fixtures, any spacer rings, the mud ring, and the top, existing fixed-length extensions have to be removed. An overlay protection plate, not shown, is bolted to top flange 30 , on container 1 , to prevent debris from falling into container 1 . After roto-milling, a new layer of pavement is installed, and the new pavement is core-drilled at the location of each container 1 to replace the items removed back to their original position. Core drilling at each embedded container location is done to provide access for reinstalling the items previously removed. Nevertheless, in a great percentage of the cases, i.e., at each of the individual container locations, differences of height occur, creating the need for the installation of additional flat spacer rings 15 on top of the ones removed and being reinstalled.
Referring to FIGS. 1 and 2, lighting fixture 95 is installed at a close tolerance 17 slightly above pavement surface 24 . The optical system, not shown, inside the lighting fixture, projects its light beam 32 through lens 107 in window 108 of lighting fixture 95 at a precise angle 34 from surface 24 to allow a pilot landing aircraft 51 , as shown in FIG. 3, see light beam 32 , from a distance of about one-half mile (1 kilometer), when landing at night or under other low visibility conditions. Lighting fixtures 95 are also known as centerline lights because they are installed on the embedded containers in the center of the aircraft ground traffic areas, i.e., runways, taxiways, and others.
The continuous landing of aircraft, day and night, year after year, on top of these lighting fixtures can provide a slight tilting 41 , as shown in FIG. 2, of the lighting fixture and fixed-length extension 11 , as represented by 41 (not to scale), as shown in FIG. 2, for the purpose of making this explanation more clearly understood. This tilting 41 will alter the installed height tolerance 17 , as shown in FIG. 1, which now would be larger as represented by 42 in FIG. 2 . The maximum installed height tolerance 17 is {fraction (1/16)} inch (1.6 mm), per F.A.A. (U.S. Federal Aviation Administration) specifications. Tilting 41 is shown as a separation of flange 10 of fixed-length extension 11 from flange 9 of fixed-length extension 7 .
Even the slightest tilting of lighting fixture 95 and the associated extension produces an angular deviation, angle 35 , as shown in FIGS. 2 and 3, which is larger than the precise angle 34 obtained by a combination of the precise height adjustment of lighting fixture 95 and the angle at which light beam 32 is emitted from lighting fixture 95 , through its lenses 107 , in windows 108 , as shown in FIGS. 1 and 2. This lighting fixture emitted light beam angle is set at the factory and is precisely established by F.A.A. regulations.
An increased angle 35 would project emitted light beam 33 away from a line of sight from the pilot when landing aircraft 51 , as shown in FIG. 3, as it descends for landing. As a result, the pilot of aircraft 51 would not be able to see light beam 33 when landing at night or during poor visibility conditions. An increase in the height adjustment 17 of lighting fixture 95 would have the same effect, i.e., the light beam would not be visible to the pilot at landing. In addition, an increased installed height creates the danger of the lighting fixture being plowed-off, during winter time, when snow is regularly plowed off airport ground traffic areas. This creates the danger of lighting fixtures, bolts, rings, and other components, being thrown onto these traffic areas, with the resulting danger to landing aircraft.
Conventionally, tilting is field-corrected by installing a thick tapered spacer ring, not shown. These tapered rings are custom made, per field measurement, and they are installed after first removing some of the existing flat spacer rings 15 , to correct angular deviation 35 of light beam 33 to the correct angular adjustment 34 of the light beam. Tilting of the fixed-length extension is corrected, when the apparatus and methods of the present invention are utilized, because fixed-length extensions, bolted one on top of the other are no longer required.
Referring to FIGS. 7, 8 , and 9 , lighting fixtures today are manufactured with two different types of bottom portions. FIG. 7 shows lighting fixture 95 with six non-threaded, counter sunk bolt holes 109 drilled through mounting flange 106 . Bolt holes 109 are set apart at an angle 115 of 60 degrees one from another, in bolt circle 114 . Lighting fixture 95 is provided with optical lenses 107 in countersunk windows 108 and with a flat, short, straight down bottom portion 100 . Electrical wires 111 and connector 112 are provided for bringing electrical power to lighting fixture 95 from an isolation transformer, not shown, in conventional container 1 , as shown in FIGS. 1 and 2.
Lighting fixture 105 of FIG. 8 has six non-threaded, countersunk bolt holes 109 drilled through mounting flange 106 . Bolt holes 109 are set apart at an angle 115 of 60 degrees one from another, in bolt circle 114 . Lighting fixture 105 is provided with optical lenses 107 in countersunk windows 108 and with a long, angled bottom 110 , hence the novel angled 66 opening 67 of adjustable extension 55 , as shown in FIG. 4 . Angled 66 opening 67 allows lighting fixture 105 to be installed on flange 62 of the extension, in addition to allowing also the installation of lighting fixture 95 , as shown in FIG. 7 .
Continuing to refer to FIG. 8, lighting fixture 105 is also provided with wires 111 and connector 112 for bringing electrical power to lighting fixture 105 from conventional embedded container 1 , as shown in FIGS. 1 and 2.
Azimuth orientation arrows 113 are engraved on mounting flange 106 in the countersunk windows 108 area. Arrows 113 are also engraved in countersunk windows 108 of lighting fixture 95 . The difference between lighting fixture 95 and lighting fixture 105 is in the short, flat bottom portion 100 of fixture 95 versus the longer, angled bottom portion of fixture 105 .
Engraved azimuth arrows 113 are required for aiding a lighting fixture installer in orienting lenses 107 , on windows 108 , directly to the exact azimuth alignment, to correctly align, in azimuth, the light beam projected through lenses 107 with the aircraft landing direction. The azimuth alignments are required when the lighting fixture is first installed and on every occasion maintenance is performed on the fixture, i.e., removal for bulb change and others.
FIG. 9 is a top view, i.e., a plan view, of the lighting fixtures of FIGS. 7 and 8. The lighting fixtures 95 , 105 have six countersunk bolt holes 109 each on bolt circle 114 , with a bolt circle diameter identical to the diameter of the bolt circle, not shown, of bolt holes 64 , on top flange 62 , as shown in FIG. 4 .
The bolt circle diameter, the number and size of bolts and bolt holes in the lighting fixtures, as well as in the flange where the lighting fixtures are to be installed, i.e., top flange 62 , as shown in FIG. 4, or in conventional top flange 13 , as shown in FIG. 1, are specified by specifications known as Circulars, issued by the F.A.A.
Referring now to FIGS. 4, 5 , and 6 , adjustable extension 55 and adapter flange 85 represent the preferred embodiment of the alignments adjustments assembly of the present invention.
Adjustable extension 55 consists of a tubular, cylindrical section, defined by a non-threaded top portion 58 which has its bottom portion 57 threaded with Acme threads 56 , e.g., by way of example at four threads per inch (2.54 cm). Top portion 58 and bottom threaded portion 57 are the wall of the cylindrical portion, i.e., the wall of a tubular cylinder, shown in elevation, partially in section, in FIG. 4 .
Acme threaded portion 57 is threaded for approximately six inches (15 cm) from bottom end 61 . Threaded portion 57 has a minimum of six vertical rows of threaded holes 59 , 60 , i.e., parallel to its vertical axis 68 , as opposed to three vertical rows of holes at 120 degrees apart, disclosed in U.S. patent application Ser. No. 08/002,014 filed Jan. 8, 1993 entitled “Alignments Adjustments Assembly Apparatus and Method,” now U.S. Pat. No. 5,541,362. Holes 59 are on a horizontal plane different from holes 60 , i.e., intercalated, i.e., staggered as shown in FIG. 4, so that at all times there will be a minimum of four and a maximum of six holes 59 , 60 for threading Allen set-screws 81 , as shown in FIG. 5, through them and for tightening against inside threaded surface 87 of adapter flange 85 , as shown in FIG. 6 . By the method of the present invention, at least one Allen set-screw 81 , as shown in FIG. 5, protruding through holes 59 or 60 , penetrates at least one eighth inch (3.2 mm) into a drilled aperture 86 , as shown in FIG. 6, on inside threaded surface 87 of adapter flange 85 .
Allen set-screws are threaded through both holes 59 and 60 , shown threaded through hole 59 on FIG. 5 for simplification purposes. Allen set-screws are of a minimum ½ inch (1.3 cm) nominal diameter.
Top flange 62 is welded at top portion 71 of the tubular, cylindrical portion of the extension 55 . Top flange 62 has 12 threaded bolt holes 64 through it, when seeing it in plan, but shown only in section in FIG. 4 . These threaded bolt holes 64 have a bolt circle diameter, not shown, that coincides with bolt circle diameter 114 , as shown in FIG. 9, of lighting fixture 95 and 105 , as shown in FIGS. 7 and 9, respectively. The bolt circle and bolt size are mandated by the F.A.A. specifications, i.e., U.S. Federal Aviation Administration specifications. All features shown on FIG. 9, a plan view, coincide with a plan view, not shown, of FIG. 7 in all respects, i.e., they are substantially identical. Therefore, either lighting fixtures of FIG. 7 or FIG. 8 can be bolted onto top flange 62 .
Top flange 62 has opening 67 at an angle 66 of approximately 45 degrees. In addition to accepting lighting fixture 95 , as shown in FIG. 7, it also accepts lighting fixture 105 , as shown in FIG. 9 .
Preferably top flange 62 and tubular cylindrical portion 57 are made of stainless steel. The stainless steel assembly 55 of the present invention provides an alignment adjustments assembly which corrects the problem of corrosion from materials such as corrosive deicing chemicals or by a galvanic action between dissimilar metals between the light bolts and the light support.
Novel mud dam protecting ring 69 , consisting of a 1 to 1¼ inches wide (2.54 to 3.27 cm), thin, stainless steel band, is built in one piece with top flange 62 , if adjustable extension 55 is built in one piece, which is the preferred method. Mud dam protecting ring 69 can also be welded all around the outer periphery of top flange 62 if adjustable extension 55 is built of individual components. Mud dam 69 is positioned to protect the lighting fixture and its lenses 107 , as shown in FIGS. 7, 8 , and 9 from grout 122 , as shown in FIG. 11, when grout 122 is poured. Groove 65 is provided on surface 63 of top flange 62 in order to accept “O”-ring 70 , shown lifted from groove 65 , on FIG. 4 .
The adjustable extension of the present invention can be cast, in one piece, e.g., from stainless steel, comprising the tubular, cylindrical portion as well as the top flange 62 and mud dam protection ring 69 . It can then be machine-finished including groove 65 and mud dam protection ring 69 . Acme-threads 56 are cut for a minimum of up to 6 inches (15 cm) or more from bottom end 61 . All holes 59 , 60 , and 64 are then drilled and tapped. Preferably, each individual component is made of stainless steel.
The adjustable extension can also be made of individual components, i.e., a tubular piece, to obtain the cylindrical portion and a standard steel plate, machine-finished to obtain the top flange 62 , to which a thin, steel band is welded to make the protection ring 69 . Then the flange 62 is welded at 71 , top end of non-threaded portion 58 of the tubular piece, i.e., the cylindrical portion. Any additional machine-finishing then is done, including groove 65 . Acme threads 56 are cut for a minimum of 6 inches (15 cm) or more from bottom end 61 . All holes 59 , 60 , and 64 are then drilled and tapped.
Optionally, Acme threads 56 could be cut, and holes 59 and 60 drilled and tapped in the field at the point of use.
The order in which the fabrication steps are herein described, i.e., for casting in one piece or for individual components, is not intended to limit the many variations of manufacturing sequencing, as those skilled in the art would recognize. Therefore, all sequencing steps, whether listed or not, are part of the apparatus and method of the present invention.
As it can be readily understood by those skilled in the art, the adjustable extension can be made in any overall length, including any length of its threaded portion 57 . This feature provides the design engineers a great advantage in planning for future aircraft ground traffic changes, i.e., additional layers of pavement or the replacement of existing layers of pavement with new, thicker layers, to upgrade these aircraft traffic areas to new generations of larger, heavier aircraft.
FIG. 5 represents the Allen set-screw 81 component of the present invention shown threaded-in and protruding through threaded portion 57 of the adjustable extension.
FIG. 6 represents the circular adapter flange 85 component part of the present invention shown in elevation. Non-threaded aperture 86 is at least ⅛ inch (3.2 mm) deep, drilled into Acme threaded surface 87 in opening 88 . Inside opening 88 is threaded with 4 Acme threads per inch (2.54 cm) in order to thread extension 55 into it. Non-threaded holes 89 are 12 in number (only two shown) and are drilled through surface 90 . Bolt holes 89 are drilled on a bolt circle, not shown, identical to the bolt circle 137 , as shown in FIG. 12, on top flange 30 of conventional embedded container 1 , as shown in FIGS. 1 and 2. Adapter flange 85 thereby provides the means for the installation of adjustable extension 55 onto embedded stainless steel container 1 A, as shown in FIGS. 11 and 12.
For the installation of the alignments adjustments assembly of the present invention on airport runway embedded stainless steel container 1 A, adapter flange 85 is bolted onto top flange 30 , as shown in FIGS. 1, 2 , and 12 of embedded container 1 after removing bolts 3 , as shown in FIGS. 1 and 2 and all fixed-length extensions 2 , 7 , and 11 . When adapter flange 85 is bolted onto stainless steel container 1 A, the adjustable extension 55 can be threaded into adapter flange 85 , through Acme threaded opening 88 , in order to install an airport inset lighting fixture upon top flange 62 , as shown in FIGS. 4 and 11, of adjustable extension 55 .
All Allen set screws are threaded through holes 59 , 60 of extension 55 and torqued to a minimum of 60 foot-pounds (8 kilogram-meters) against Acme threaded surface 87 of adapter flange 85 , one of them, torqued against the inside of drilled aperture 86 .
Referring now to FIG. 11, a completed installation of the apparatus of the present invention is represented. Aperture 86 on Acme threaded surface 87 is drilled as follows. First, adjustable extension 55 with “O” ring 70 , in groove 65 and with lighting fixture 105 bolted onto it, as shown in FIG. 11, is threaded into adapter flange 85 , which has been bolted already onto stainless steel container 1 A by means of bolts 121 . Lighting fixture 105 on adjustable extension 55 then is brought to the exact height and azimuth by threading in adjustable extension 55 until azimuth orientation arrows 113 are aligned to the precise azimuth at the required height. Prior to any installation, a surveyor provides the necessary centerline marks 138 , as shown in FIG. 12, on the pavement, i.e., of a runway, for aiding the installer in finding the correct azimuth line. At this point, the lighting fixture is removed, and all required Allen set-screws are installed through holes 59 , 60 of adjustable extension 55 and fully torqued at 60 foot-pounds (8 kilogram-meters) against Acme threaded surface 87 to immobilize adjustable extension 55 in place, keeping it at the desired azimuth alignment and height adjustment. Then, aperture 86 is drilled approximately ⅛ inch (3.2 mm) into surface 87 of adapter flange 85 , through one of threaded holes 59 or 60 of the adjustable extension 55 . Immediately after aperture 86 is drilled-in, the remaining Allen set-screw 81 is threaded through the respective hole 59 or 60 and fully torqued at 60 foot-pounds (8 kilogram-meters) against the inside of aperture 86 . By making at least one Allen set-screw 81 penetrate at least ⅛ inch (3.2 mm) into aperture 86 , on surface 87 of adapter flange 85 , by installing six Allen set-screws, and by making the set-screw ½ inch (12.7 mm) in diameter, the adjustable extension 55 and the lighting fixture mounted thereupon will not be made to turn by the torque tangentially applied by the force of airplane wheels, including those of the newer, heavier airplanes landing upon the lighting fixtures or by the twisting action created by heavy aircraft locked wheels when turning. All holes 59 , 60 not utilized are plugged-in with threaded, plastic plugs, not shown. When holes 59 , 60 are plugged-in, the lighting fixture is connected to electrical power connector 123 from imbedded container 1 by means of cable 111 and connector 112 . Then the lighting fixture is re-bolted onto top flange 62 of adjustable extension 55 with its azimuth orientation arrows 113 aligned in azimuth, by means of bolts 120 . “O” ring 70 is compressed by the bolting pressure, thereby providing a tight water seal. Angled bottom 110 of lighting fixture 105 fits very well in angled 66 opening 67 , as shown in FIG. 4, of the adjustable extension.
At this point, the installation is completed by pouring-in grout 122 all around the alignments adjustments assembly 55 , 85 , of the present invention. It can be seen that the novel protection ring 69 , as shown in FIGS. 4 and 11, prevents grout 122 from getting on the lighting fixture, especially so on its lens 107 through window 108 . It is also readily understood that groove 65 , as shown in FIG. 4, provided on surface 63 of top flange 62 of adjustable extension 55 eliminates the requirement for installing a separate spacer ring with a groove on it for the installation of “O” ring 70 .
The alignments adjustments assembly of the present invention is reusable. When the alignments adjustments assembly is installed and the airport aircraft ground traffic area is modified, creating a higher or lower surface, i.e., if surface 24 were made higher or lower, extension 55 can be threaded in or out, after first removing all Allen set-screws 81 , to provide a new height adjustment without affecting the azimuth alignment. Azimuth is a straight line, i.e., toward the horizon, in the direction of aircraft landings, with the centerline 138 , as shown in FIG. 12, of the aircraft ground traffic area runway, taxiway, defining this straight line. Thus the embedded containers with their inset lights mounted thereupon all are installed at a specified distance one from another on this centerline for the length of the aircraft ground traffic area.
At the time embedded stainless steel container 1 A is first installed, its top flange 30 , as shown in FIG. 12, is aligned in azimuth, by aligning centerline 138 of the aircraft ground traffic area to pass exactly aligned with two diametrically opposed threaded bolt holes 136 . Prior to its installation, a surveyor provides markings on the pavement for aiding in the azimuth alignment of stainless steel container 1 A. Bolt holes 136 are at an angle 135 of 30 degrees apart, and they are set on bolt circle 137 with a diameter identical to bolt circle 114 , as shown in FIG. 9, on the lighting fixtures 95 , 105 . Bolt circle diameter 137 on top flange 30 also is identical to the bolt circle diameter, not shown, on adapter flange 85 , which bolts thereupon, by the method of the present invention.
Adjusting the height of adjustable extension 55 would not affect the azimuth alignment of a lighting fixture installed upon its flange 62 , as shown in FIG. 11, because extension 55 Acme threaded portion 57 is provided with at least four Acme threads 56 per inch (2.54 cm). At four Acme threads per inch (2.54 cm), it would take four full, 360 degree turns of adjustable extension 55 , for it to go up or down one inch (2.54 cm). Therefore the adjustable extension will move up or down only ¼ inch (6.3 mm) when rotated 360 degrees about its axis 68 , i.e., one single, complete rotation. A 30 degree turn of adjustable extension 55 will produce a height change of only 0.0208 inches (0.05 mm), up or down, i.e., one twelfth of ¼ inch (6.3 mm). The measure of 0.0208 inches (0.05 mm) is slightly more than {fraction (1/64)} inch (1.6 mm) The overall tolerance 17 , as shown in FIG. 1 is {fraction (1/16)} inch (1.6 mm). A 30 degree turn equals one twelfth of one full 360 degree rotation. Therefore, adjustable extension 55 can be rotated a few degrees about its axis 68 in any direction to obtain a very precise azimuth alignment without negatively affecting its height adjustment. Any azimuth alignment adjustment would always be 15 degrees or less because bolt holes 109 , as shown in FIG. 9, of the lighting fixtures, by FAA mandate, are spaced apart 60 degrees, i.e., only six holes. Bolt holes 64 on top flange 62 , as shown in FIG. 4, are spaced at 30 degrees, exactly the same as bolt holes 136 , as shown in FIG. 12, on top flange 30 of the embedded container, i.e., 12 bolt holes, also by FAA specifications. The diameter of bolt circles 114 , as shown in FIG. 9, and 137 , as shown in FIG. 12, are also identical to that of the top flange 62 . Accordingly, a 30 degree azimuth alignment adjustment is obtained by properly positioning the lighting fixture upon top flange 62 of adjustable extension 55 , matching its bolt holes 109 with the two bolt holes 64 on flange 62 , positioning arrows 113 closest to the correct azimuth alignment marked on the pavement by a surveyor. The final, precise adjustment of 15 degrees or less is done by simply turning the adjustable extension. From FIG. 9, it can be seen that windows 108 are centered between two bolts 109 , and, therefore, orientation arrow 113 is at 30 degrees apart from the two adjacent bolt holes 109 .
Referring now to FIGS. 13 and 14, a universal top adjustable alignment container 255 is shown in elevation in FIG. 13 and in plan view, i.e. top view, in FIG. 14 . The non-corrosive top adjustable alignment container 255 is another preferred embodiment of the present invention.
FIG. 13 shows, for the purpose of illustration, an airport inset light 205 , a new type of airport inset lighting fixture, manufactured by Hughes Phillips. The novel features of the universal top adjustable alignment container 255 allow the installation of any of the three types of lighting fixtures that exist in the U.S. market today, e.g., lighting fixture 95 , shown in elevation in FIG. 7 and in plan view in FIG. 9; lighting fixture 105 , shown in elevation in FIG. 8 and in plan view in FIG. 9; and the newest inset lighting fixture 205 , shown in elevation in FIG. 13 .
Any of the three lighting fixtures 95 , 105 , and 205 can be installed on the universal top adjustable alignment container 255 without requiring its top flange 262 to have an angled opening 66 (FIG. 4 ), as it is required for the flange 62 of the adjustable extension 55 of FIG. 4 .
Continuing to refer to FIG. 13, the novel top flange 262 of the universal top adjustable alignment container 255 has an opening 267 with a straight inside surface 266 instead of an angled inside surface 66 as shown in FIG. 4 . In addition, the top flange 262 is thicker than the top flange 62 of FIG. 4 . This additional thickness allows a stepped bottom 201 of the lighting fixture 205 to be perfectly fit inside the opening 267 of the top flange 262 , with a flange 206 inside the mud dam 269 .
The universal top adjustable alignment container 255 of FIG. 13 is preferably cast in one piece, in stainless steel. The casting can then be machined to form the top flange 262 , a flat surface 263 , with a groove 265 in it, the mud dam 269 , and an opening 267 , with its straight surface 266 . Twelve threaded holes 264 (only two shown) are drilled and tapped through the surface 263 of the flange 262 . Then acme threads 256 are cut, at four threads per inch, on a surface 257 for a minimum of six inches from a bottom a 261 of a tubular section 257 . The tubular section 257 is of a required wall thickness 274 to allow for the required strength of the threads to resist shearing forces created by the axial loading forces applied upon the lighting fixtures by landing aircrafts. At this point, holes 259 and 260 are drilled and tapped through the tubular section 257 , through its wall thickness 274 .
Holes 259 and 260 are intercalated, i.e., staggered. These holes 259 and 260 , if required, could be drilled and tapped in the field instead of in the factory. Nevertheless, drilling and tapping holes 259 and 260 in the field is not the preferred method because it is not cost effective, and it is inefficient.
Threaded bolt holes 264 of the top flange 262 are a total of twelve, i.e., at 30 degrees 235 from each other, as shown on FIG. 14 . These holes 264 are drilled and tapped through a surface 263 of the flange 262 on a bolt circle 214 (FIG. 14 ), which is similar to the bolt circle 114 of FIG. 9, on the lighting fixtures 95 and 105 of FIGS. 7 and 8, respectively.
Bolt holes 209 of lighting fixture 205 are drilled through flange 206 on a bolt circle (not shown) similar to bolt circle 214 on top flange 262 . Lighting fixture 205 has six bolt holes (only two shown) spread at sixty degrees apart, similar to the configuration 235 shown of FIG. 9 for lighting fixtures 95 , 105 . The number of holes, sizes, and degrees apart are all mandated by the FAA, i.e., the Federal Aviation Administration, in specifications known as FAA Circulars.
Lighting fixture 205 of FIG. 13 has a stepped bottom comprising a portion 201 and a portion 200 . The portion 200 provides electrical wires 211 that bring electrical power to the lighting fixture 205 . Flange 206 is utilized to install the lighting fixture upon surface 263 of top flange 262 of universal top adjustable container 255 , inside its mud dam 269 . Lighting fixture 205 , when bolted onto top flange 262 , compresses an “O” ring 270 in a groove 265 , providing a water tight seal between the lighting fixture 205 and the inside of the universal top adjustable alignment container 255 of FIG. 13 .
Lighting fixture 209 has two countersunk windows 208 , similar to the countersunk windows 108 on lighting fixtures 95 , 105 of FIG. 9 . The lighting fixture 205 also has one azimuth orientation arrow (not shown) engraved in each of countersunk windows 208 . The countersunk windows 208 , engraved azimuth arrows, lighting system, and their angular positioning for all lighting fixtures manufactured in the U.S. are all very similar and they are all mandated by FAA regulations, i.e., FAA Circulars.
Engraved azimuth arrows (not shown) on the lighting fixture 205 are utilized to aid the installer in aligning the lighting fixture 205 in azimuth, on the runway centerline and in the direction 32 of landing aircraft 51 (FIG. 3 ).
Referring now to FIG. 14, a plan view, i.e., a top view, of the universal top adjustable alignment container 255 , of FIG. 13, is shown. FIG. 14 shows the top flange 262 , with its mud dam 269 and twelve threaded holds 264 drilled and tapped on the bolt circle 214 , at thirty degrees 235 from each other. FIG. 14 also shows groove 265 in surface 263 of top flange 262 . Groove 265 is provide for receiving “O” ring 270 . In addition, FIG. 14 shows straight surface 266 of inside opening 267 and inside surface 274 of tubular section 257 .
The universal top adjustable alignment container of the present invention can also be fabricated of individual components, which can be welded together. By way of an example, top flange 262 can be welded at 271 to the tubular section 257 , and mud dam 269 can be made of a piece of thin steel welded to the outer periphery of top flange 262 . Any machining including the cutting of acme threads 256 and the drilling and tapping of holes 259 , 260 , and 264 can be done at the time each component is fabricated or after all or part of the components have been welded together.
Whether cast in one piece or fabricated of individual components, the universal top adjustable alignment container 255 preferably is made of stainless steel, to provide for corrosion resistance.
The alignments adjustments precision makes the apparatus of the present invention an efficient and economical apparatus and method for the replacement of conventional, existing fixed-length extensions at the time of renovation, i.e., resurfacing of aircraft ground traffic areas, as well as for new installations of such traffic areas by eliminating the need for installing fixed-length extensions, by eliminating the need for installing several flat spacer rings of various thicknesses, by eliminating the need for installing and angle-correcting, tapered spacer rings, i.e., leveling rings, and by eliminating the need for installing a separate mud dam. In addition, the installation of alignments adjustments assembly of the present invention saves labor costs, and the assembly is reusable.
Thus it can be seen that the invention accomplishes all of its objectives.
The apparatus and process of the present invention are not limited to the descriptions of specific embodiments presented hereinabove, but rather the apparatus and process of the present invention should be viewed in terms of the claims that follow and equivalents thereof. Further, while the invention has been described in conjunction with several such specific embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing detailed descriptions. Accordingly, this invention is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims.
|
An airport inset light adjustable alignment container set provides a light fixture and stainless steel support for airport runway, taxiway, or other aircraft ground traffic areas. A variable length extension means rotatably adjusts height and azimuth by a rotatable vertical displacement. In one aspect, a previously installed, airport inset light and stainless steel base of the present invention receives a variable length extension assembly for rotatably adjusting the height and azimuth alignment of an airport inset light. Rotation locking means are provided for securing the rotatable adjustment apparatus from further rotation. A novel stainless steel base is adapted to receive various different designs of inset lights and, in one aspect, to provide a stainless steel protection ring “mud dam.”
| 4
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 08/759,760, filed Dec. 3, 1996, now pending.
The following co-pending and co-assigned application contains related information and is hereby incorporated by reference: Ser. No. 08/759,764, entitled DIGITAL STEP GENERATORS, SYSTEMS AND METHODS USING THE SAME, filed Dec. 3, 1996.
TECHNICAL FIELD OF THE INVENTION
The present invention relates in general to electronic memories and in particular to precision sense amplifiers and systems and methods using the same.
BACKGROUND OF THE INVENTION
In applications where access time is not critical, dynamic random access memory devices (DRAMs) have several advantages over other types of memories, in particular, static random access memories (SRAMs). In comparison to SRAMs, DRAMs are less expensive, consume substantially less power, and provide more bits in the same chip space (i.e. have a higher cell density). Hence, DRAMs are normally used to construct those memory subsystems, such as system memories and display frame buffers, where power conservation and high cell density are more critical than speed. In most computing systems, it is these subsystems which dominate the system architecture, and thus, DRAMs are the prevalent type of memory device on the market.
The cells of the typical DRAM array are arranged in rows and columns. A row is selected for access by activating a corresponding conductive wordline. Data accesses (reads and writes) are made to the cells of the selected row through conductive bitlines associated with each of the corresponding columns. Conventionally, each bitline is formed by a pair of half-bitlines. The cells coupled to one half-bitline form part of one set of rows, for example the even rows, and are therefore controlled by the corresponding set of even wordlines. Similarly, the cells coupled to the other half-bitline form part of a second set of rows, for example the odd rows, and are controlled by the corresponding set of even wordlines. A differential sense amplifier is provided to sense the voltage difference between each half-bitlines pairs during an access.
Wordline activation is by row address, as decoded by a row decoder. Typically, all cells of a selected row are activated and their data sensed and latched by the sense amplifiers. A column decoder coupled to the sense amplifiers selects one or more of the physical columns for access in response to a column address. For example, in a "by 8" device, eight physical columns are accessed per column address.
The vast majority of DRAMs require two operational periods per row access (precharge and active), as timed by a row address strobe (/RAS) and a column address strobe (/CAS). These two periods together constitute one cycle. When /RAS is in a logic high state, the DRAM device is in a precharge cycle, during which the nodes of various dynamic circuits, such as those used in the column and row decoders, are pulled to a predetermined voltage. Most importantly, during the precharge cycle the bitlines of the cell array are voltage equalized. Then, when /RAS transitions to a logic low, the device enters the active cycle. In Synchronous DRAM's, where a master clock controls the operation, /RAS and /CAS are timed off that particular master clock.
Typically, during the active cycle, the row address bits are presented to the address pins and latched into the DRAM device with the falling edge of /RAS. After a very small delay for set up, the column address bits are presented at the address pins and latched-in with the falling edge of /CAS. A short time thereafter the addressed cells (location) can be accessed. During page mode, additional column addresses are input with additional falling edges of /CAS (/CAS cycling) to access a series of "pages" along the selected row. At the end of the active cycle, /RAS returns to a logic high state and the device re-enters precharge (in any event, when a change in row is required, a complete new /RAS cycle, including a new precharge cycle and a new active cycle must be initiated.)
During a voltage-high precharge, all of the half-bitlines in the array are precharged to a predetermined voltage, for example 3.3 volts for a 3.3 V Vcc device, and then allowed to float (in some devices, precharge is to substantially zero volts but for purpose of the present discussion, precharge towards Vcc is assumed). Currently, the typical precharge cycle is between 50-60 nsec in length (the typical active row-reader or row-write cycle also known as random access cycle is also approximately 50-60 nsec long). While the nodes of most of the dynamic circuitry, such as that used in the row and column decoders, can be charged or discharged within 10 nsecs, the full 50 to 60 nsecs is required to precharge and equalize the bitlines of the cell array. A page cycle, or a burst cycle in a Synchronous DRAM could be shorter.
During the active cycle, the wordline selected in response to the received row address is activated and all the cells along the corresponding row are turned on. In this disclosure, all logic is positive--namely Logic 0 is V ss and Logic 1 is V cc . If the storage capacitor of a given activated cell is at ground potential (a logic 0), the corresponding half-bitline is pulled down slightly relative to the complementary half-bitline (the voltage on which is set by a reference or "dummy" cell). If the storage capacitor of a given active cell is at a higher voltage charge (a logic 1) the corresponding half-bitline is pulled up slightly (or maintained at V cc ) relative to its complementary half-bitline. During a read or refresh, the sense amplifiers differentially detect the voltage different between each half-bitline pair and latch one half-bitline of the pair to a full logic high and the other to a full logic low, depending on the direction of the swing. During a write of a logic 0, the sense amplifiers pull down the half-bitline which is to carry the logic zero and latch-high the other half-bitline. A write of a logic 1 is similar.
The voltage swings caused by the cell storage capacitors on the bitlines are extremely small. The typical storage cell capacitor has a capacitance of approximately 25-35 fF (femtofarads) while the half-bitline it couples with has a capacitance of approximately 300-500 fF. Therefore, to avoid incorrect sensing of the stored logic state, the precharge voltage on each bitline pair must be equalized during precharge as closely as possible. Notwithstanding, some voltage imbalance will always exist, often on the order of 2 to 3 millivolts. For example, constraints on the chip fabrication processes result in differences in the resistance and capacitance between the half-bitlines in each half-bitline pair. Similarly, the widths and lengths of the channels, and thus threshold voltages and gains, will vary between the (cross coupled) transistors in the sense amplifiers.
Additional problems must be accounted for during sensing. For example, it would be desirable to turn-on the sense amplifiers very quickly (e.g. on the order of 5 nanoseconds) to provide a short access time. However, if the "bottom" transistor controlling current flow through the sense amplifier differential transistor pair is turned on rapidly, capacitive coupling effects can cause unwanted voltages to couple to half-bitlines and cause mis-sensing.
Thus, the need has arisen for precision sense amplifier circuitry and methods and systems using the same. Among other things, such circuitry and methods should allow for fast, accurate sensing. In particular, problems associated with the differential sensing of small voltages should be accounted for while minimizing the coupling of noise voltage from the bottom capacitor. These circuits and methods should preferably be applicable to DRAMs, but should also be adaptable for use in other types of memories, such as SRAMs.
SUMMARY OF THE INVENTION
According to a first embodiment of the principles of the present invention, an amplifier is provided which includes a differential pair of transistors and a third transistor for controlling current through the transistors of the differential pair. The third transistor controls the current in response to a stepped control voltage signal.
According to a second embodiment of the principles of the present invention, a sense amplifier is provided which includes an amplification stage. The amplification stage includes a first transistor having a current path coupled to a first sensing node and a control terminal coupled to a second sensing node. The second transistor is included having a current path coupled to the second sensing node and a control terminal coupled to the first sensing node. A bottom transistor is included having a current path coupled to the current paths of the first and second transistors and a control node, a signal presented to the control terminal of the bottom transistor as a stepped voltage (with time).
According to a further embodiment of the principles of the present invention, a memory is provided which includes a bitline comprising first and second half-bitlines, at least one cell coupled to the first half-bitline and at least one cell coupled to the second half-bitline. The memory also includes a sense amplifier coupled between the first and second bitlines for detecting a voltage difference therebetween with current through the sense amplifier (transistors) controlled by a control signal having at least two steps.
The principles of the present invention are also embodied in memory sensing circuitry including a reference cell having a reference capacitance provided by a plurality of capacitors. The plurality of capacitors may comprise stacked capacitors and they may be coupled in series or in parallel.
The principles of the present invention are also embodied in methods of sensing digital data. According to one such method, a pair of half-bitlines is pre-charged. A storage cell coupled to a selected one of the half-bitlines is activated along with a reference cell coupled to a complimentary one of the half-bitlines. The voltage difference between the first and second half-bitlines is sensed with a amplifier coupled between the pair of half-bitlines. During an initial period when the voltage difference is small, current flow is initiated through the sense amplifier with at least one voltage step of a multiple step control signal to gradually amplify the voltage difference of the sensing nodes. During a subsequent period, the current flow through the sense amplifier is increased with at least one additional step of the multiple step control signal to further amplify the voltage difference.
Differential amplifiers, and in particular the sense amplifier embodiments thereof, according to the principles of the present invention, have substantial advantages over the prior art. Among other things the principles of the present invention allow for fast, accurate sensing with minimal risk of mis-sensing. In particular, the problems associated with the differential sensing of small voltages, such as those found during the sensing of memory cells, is provided. Further, these advantages are provided while at the same time minimizing the coupling of noise voltage from bottom transistor capacitance. The principles of the present invention may be applied to DRAMs, SRAMs, or other types of memories and may be constructed using either field effect transistors or bipolar transistors, or a combination thereof.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1A and 1B are high level functional block diagrams of exemplary data processing systems embodying the principles of the present invention;
FIG. 2 is a more detailed block functional diagram of an exemplary memory device according to the principles of the present invention;
FIG. 3 is an electrical schematic diagram of a first preferred sense amplifier, shown coupled to an exemplary half-bitline pair and exemplary memory cells, embodying the principles of the present invention;
FIG. 4 is a voltage-versus-time conceptual timing diagram illustrating the operation of the circuitry of FIG. 3 during a typical access;
FIG. 5 is an electrical schematic diagram of a second preferred sense amplifier, shown coupled to an exemplary half-bitline pair, and exemplary memory cells, embodying the principles of the present invention;
FIG. 6 is a high voltage versus time conceptual timing diagram illustrating the operation of the circuitry of FIG. 5 during a typical access; and
FIGS. 7A and 7B are electrical schematic diagrams of preferred reference cells embodying the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The principles of the present invention and their advantages are best understood by referring to the illustrated embodiment depicted in FIGS. 1-7 of the drawings, in which like numbers designate like parts. While memory devices embodying the principles of the present invention are useful in a wide number of applications, for purposes of illustration, such memory devices will be described in conjunction with a basic processing system architecture typically employed in personal computers.
FIG. 1 is a high level functional block diagram of a portion of a processing system 100. System 100 includes a central processing unit 101, a CPU local bus 102, core logic 103, a display controller 104, a system memory 105, a digital to analog converter (DAC) 106, frame buffer 108, a display device 107 and an optional display device 107.
CPU 101 is the "master" which controls the overall operation of system 100. Among other things, CPU 101 performs various data processing functions and determines the content of the graphics data to be displayed on display unit 107 in response to user commands and/or the execution of application software. CPU 101 may be for example a general purpose microprocessor, such as an Intel Pentium™ class microprocessor or the like, used in commercial personal computers. CPU 101 communicates with the remainder of system 100 via CPU local bus 102, which may be for example a special bus, or a general bus (common in the industry).
Core logic 103, under the direction of CPU 101, controls the exchange of data, addresses, control signals and instructions between CPU 101, display controller 104, and system memory 105. Core logic 103 may be any one of a number of commercially available core logic chip sets designed for compatibility with the remainder of the system, and in particular with CPU 101. One or more core logic chips, such as chip 112 in the illustrated system, are typically "address and system controller intensive" while one or more core logic chips, such as chip 114 in FIG. 1, are "data intensive." Address intensive core logic chip 112 generally: interfaces CPU 101 with the address path of CPU bus 102; maintains cache memory, including the cache tags, set associative cache tags and other data necessary to insure cache coherency; performs cache "bus snooping"; generates the control signals required for DRAMs in the system memory or cache; and controls general management transactions. Data intensive chip 114 generally: interfaces CPU 101 with the data path of CPU bus 102; issues cycle completion responses to address chip 112 or CPU 101; may abort operations if their cycles are incomplete; and arbitrates for the data path of bus 102.
CPU 101 can directly communicate with core logic 103 or through an external (L2) cache 115. L2 cache 115 may be for example a 256 K Byte fast SRAM device(s). It should be noted that CPU 101 can also include on-board (L1) cache, typically up to 16 kilobytes.
In addition to the conventional functions described above, core logic 103 and/or CPU 101 provide the additional functions described below, either through software programming (such as in the core logic 103) or hardware modification.
Display controller 104 may be any one of a number of commercially available VGA display controllers. For example, display controller 104 may be one of the Cirrus Logic CL-GD754x series of display controllers. The structure and operation of such controllers is described in CL-GD754x Application Book, Rev 1.0, Nov. 22, 1994, and CL-GD7542 LCD VGA Controller Preliminary Data Book, Rev. 1.0.2, June 1994, both available from Cirrus Logic, Inc., Fremont, Calif., and incorporated herein by reference. Display controller 104 may receive data, instructions and/or addresses from CPU 101 either through core logic 103 or directly from CPU 101 through CPU local bus 102. Data, instructions, and addresses are exchanged between display controller 104 and system memory 105 through core logic 103. Further, addresses and instructions may be exchanged between core logic 103 and display controller 104 via a local bus 116 which may be for example a PCI local bus. Generally, display controller 104 controls screen refresh, executes a limited number of graphics functions such as line draws, polygon fills, color space conversion, display data interpolation and zooming, and video streaming, and handles other ministerial chores such as power management. Most importantly, display controller 104 controls the raster of pixel data from frame buffer 108 to display unit 107 during screen refresh and interfaces CPU 101 and frame buffer 108 during display data update. Video data may be directly input into display controller 104.
Digital to analog converter 106 receives digital data from controller 104 and outputs the analog data to drive displays 107a and 107b (when used) in response. In the illustrated embodiment, DAC 106 is integrated with display controller 104 onto a single chip, preferably including a RAMDAC (combination digital-to-analog-converter and palette RAM) and phase locked loop (PLL). Depending on the specific implementation of system 100, DAC 106 may also include a color palette, YUV to RGB format conversion circuitry, and/or X- and Y- zooming circuitry, to name a few options. Displays 107 may be for example a CRT unit, a liquid crystal display, electroluminescent display, plasma display, or other type of display device which displays images on a screen as a plurality of pixels. It should also be noted that in alternate embodiments, "display" 107 may be another type of output device such as a laser printer or similar document view/print appliance.
The data paths in system 100 will vary with each design. For example, system 100 may be a "64-bit" or "72-bit" system. Assume for discussion purposes that a 64-bit system is chosen. Then, each of the data connections, including the data paths of CPU bus 102 and PCI bus 116, the data paths through core logic 103 to system memory 109 and display controller 104, and the data interconnection between display controller 104 and frame buffer 108, are all 64 bits wide. It should be noted that the address interconnections will vary depending on the size of the memory and such factors as the need to support data byte select, error detection correction, and virtual memory operations.
FIG. 1B is an alternate system architecture of system 100 to which the principles of the present invention may advantageously applied. In this example, memory 105 is a "unified" memory system since the system memory 109 and frame buffer 108 are collocated in a single integrated circuit or bank of integrated circuits. This is in contrast to those systems in which the frame buffer is separate and apart from the system memory and interfaces with the remainder of the system through the display controller. System memory 109 again is preferably a traditional system memory which stores data, addresses, and instructions under the command of CPU 101 as required for executing various processing functions and applications programs. As in traditional systems, the frame buffer 108 stores the pixel data required to generate the required images on the screen of display unit 107.
FIG. 2 is a high level functional block diagram of a memory subsystem (device) 200 embodying the principles of the present invention. Memory 200 may be used for example in the construction of either system memory 105 and/or display frame buffer 108 in the system of FIG. 1A or the unified memory 105 of FIG. 1B, to name a few examples. In the preferred embodiment, memory subsystem 200 is fabricated as a single integrated device (chip), although the present inventive principles are not limited to such single chip embodiments.
In the preferred embodiment, memory subsystem 200 includes one or more memory banks 201. In FIG. 2, four such banks 201, labeled Banks 0-Bank 3, are shown for illustration purposes. In alternate embodiments, the exact number of banks will vary depending on such factors as available chip space, the address space of core logic 103 and the amount of data storage capacity required.
In memory system 200, each memory bank includes two subarrays 202a and 202b of dynamic random access memory (DRAM) cells arranged as M number of rows and N number of columns. The subarrays 202a and 202b of each bank 201 are associated with column decoder/ sense amplifier circuitry 203. In memory subsystem 200, the subarrays 202a and 202b of each bank 201 are coupled to corresponding sense amplifiers in an open-bitline arrangement. For example, each subarray 202a may contain the "true" half-bitlines BLM and subarray 202b correspondingly would contain the complimentary
half-bitlines BL.sub.M for the corresponding bank 201.
Each memory bank 201 further contains precharging circuitry 204. Preferably, precharging circuitry 204 is conventional in nature, and includes one or more large pull up transistors per bank 201. A preferred interconnection of precharge circuitry 204 with the bitlines of subarrays 202 is discussed below in conjunction with FIGS. 3 and 5.
The wordlines associated with the rows of cells in each subarray 202 are coupled to and controlled by row decoder circuitry 205. Column addresses are presented to the column decoders 203 via column address bus (lines) 207. Row addresses are coupled to the blocks of row decoder circuitry 205 via a bus (lines) 208. Data is exchanged with an addressed location within the subarrays 202 of a selected bank 201 via a data bus 209 and the corresponding column decoder circuitry 203.
Data, address clocks, and control signals are exchanged with memory subsystem 200 through input/output and control circuitry 210. In system 100, these signals may be received from core logic 103 or display controller 104, depending on whether memory 200 is used as part of the system memory or the frame buffer and/or whether a unified memory architecture is being used. Circuitry 210 includes conventional clock generation circuitry for generating the clocks needed drive the dynamic circuitry of memory 200. Input/output circuitry 210 further includes conventional data buffers and latches, address level translators and address latches, page mode column incrementation circuitry and circuitry for controlling power distribution. Among the received clocks may be a master clock, if memory 200 is a synchronous DRAM.
Preferably, system 200 is designed for operation with a conventional multiplexed address bus, with row addresses input on the falling edge of /RAS and column addresses input on the falling edge of /CAS. In the illustrated embodiment, subsystem 200 includes a Y-bit wide address port (lines ADDO-ADDY) and a Z-bit wide data port (DQO-DQZ). Data reads and writes controlled by conventional write enable signal (/WE) and a conventional output enable signal (/OE).
It alternate embodiments groups of one or more banks may be independently controlled using multiple /RAS and /CAS signals. For example, banks 201a and 201b could be controlled by /RAS1 and /CAS1 and banks 201c and 201d could be controlled by /RAS2 and /CAS2. In this embodiment, one pair of banks could be in precharge while the other pair of banks are being accessed, essentially providing for interleaved accesses. Alternatively, a single /RAS signal could be used, with different sets of banks entering precharge/active periods on opposite phases. For example, banks 201a and 201b could precharge during /RAS high and enter the active period during /RAS low, while banks 201c and 201d could precharge during /RAS low and enter the active period during /RAS high.
In the preferred embodiment, row decoders 202, sense amplifiers 203 and column decoders 204 are dynamic circuitry known in the art. Typical dynamic decoding and sensing circuitry are illustrated in "A 5-volt Only 64k DRAM", L. S. White, N. H. Hong, D. J. Redwine, and G. R. Mohan Rao, International Solid State Circuit Conference 1980, Digest of Technical Papers, pp. 230-231, incorporated herein by reference.
Some of the fundamental principles of DRAM construction and operation are additionally described in: "A 64-k Dynamic RAM Needs Only One 5-volt Supply to Outstrip 16k Parts", G. R. Mohan Rao and John Hewkin, Electronics, Sep. 28, 1978, pp. 109-116; "A 4Mb DRAM With DRAM With Design-For-Test Functions," J. Neal, B. Holland, S. Inoue, W. K. Loh, H. McAdams and K. Poteet, International Solid State Circuit Conference 1986, Digest of Technical Papers, pp. 264-265; "A 4 Mb DRAM With Half Internal-Voltage Bitline Precharge, International Solid State Circuit Conference 1986, Digest of Technical Papers, pp. 270-271; "A Full Bit Prefetch Architecture For Synchronous DRAMs", T. Sunaga, K. Hosokawa, Y. Nakamura, M. Ichinose, A Moriwaki, S. Kakimi and N. Kato, IEEE Journal of Solid State Circuits, Vol 30., No. 9, Sep. 1995, pp. 994-1005; and "DRAM Macros For ASIC Chips", IEEE Journal of Solid State Circuits, Vol 30., No. 9, September 1995, pp. 1006-1014, each incorporated herein by reference.
FIG. 3 is a transistor level electrical schematic diagram depicting a representative sense amplifier 300 embodying the principles of the present invention. While the illustrated embodiments herein are constructed from field effect transistors, although in alternate embodiments bipolar transistors may also be used. Sense amplifier 300 is shown coupled between a corresponding pair of half-bitlines 301a and 301b in an open bitline configuration. In this case, half-bitline 301a is disposed in a corresponding subarray 201a, the cells of which are controlled by the even numbered wordlines X 0 -X N/2-1 (where N=1, 2 . . . , for integer values of N/2-1). Correspondingly, half-bitline 301b is disposed in the associated subarray 201b, the cells of which are controlled by the odd numbered wordlines X 1 to X N/2 (where N=1, 2 . . . , for integer values of N/2). In other words, if a wordline is chosen in the top half, the reference cell in the bottom half is accessed and vice versa. In alternate embodiments, a folded bitline approach may also be taken.
The precharging of a corresponding half-bitline 301 from the high voltage rail Vcc is controlled by one or more transistors 303 within precharge circuitry 204. There may be one precharge transistor 303 per half-bitline pair 301 or alternatively one large transistor for pulling up all the half-bitlines of each subarray 202. The precharge transistors 303 of the selected bank 201 are turned on and off in response to the precharge enable clock φ PC .
An equalization device 304 is also provided, controlled by a clock φ EQ . During precharge, φ EQ turns transistor 304 on just before the bitlines are allowed to float. This allows each half-bitline 301a (BL) and the complementary half-bitline 301b (/BL) of each pair to be voltage equalized as closely as possible.
For a complete description of precharging in sensing in DRAMs, reference is now made to the following papers which are hereby incorporated herein by reference: "High Speed Sensing Scheme for CMOS DRAMs", Dhong, et al., IEEE Journal of Solid State Circuits,. Vol. 23, No. 1, February, 1988; "50-ns 16-Mb DRAM with a 10-ns Data rate and On-chip ECC", Kalter, et al., IEEE Journal of Solid State Circuits, Vol. 25, No. 5, October, 1990; and "A Variable Precharge Voltage Sensing", Kirihata, et al., IEEE Journal of Solid State Circuits, Vol. 30, No. 1, January, 1995.
According to one embodiment of the principles of the present invention, the sense amplifier 300 has a single amplification stage including a differential pair of transistors 307a and 307b and a "bottom" transistor 306. The gates and drains of transistors 307a and 307b are cross-coupled, with voltage at sensing node A controlled by the current (source/drain) path of transistor 307a and the voltage at sensing node B is controlled by the current (source/drain) path of transistor 307b. The current flow through transistors 307a and 307b is in turn controlled by bottom transistor 306. Advantageously, the gate of bottom transistor 306 is controlled by a stepped control signal (clock) φ SB . The operation of sense amplifier 300 and the switching of clock φ SB are discussed further below in conjunction with FIG. 4. Preferred methods and circuitry for generating clock φ SB is described in copending and coassigned patent application Ser. No. 08/759,764 (Attorney's Docket No. 2836-P0054US), incorporated herein by reference.
FIG. 4 is a voltage versus time diagram illustrating the operation of sense amplifier 300 during a typical access cycle. It should be noted that FIG. 4 is a general conceptual timing diagram in which the time and voltage relationships between signals (clocks) are approximated in order to describe circuit operation.
With the rising edge of /RAS, at least one bank 201 enters the precharge period. After short delay, clock φ PC transitions high, turning on precharge device(s) 303. For illustration purposes in FIG. 4, it is assumed that after the last cycle bitline 301a and Node A maintained low residual charge from a logic zero and bitline 301b and Node B maintained higher residual charge from a logic high. Half-bitlines 301a and 301b are both charged towards Vcc, along with Nodes A and B. Next, φ PC transitions low and shortly thereafter, clock φ EQ transitions high. Equalization device 304 turns on voltage equalizing half-bitlines 301a and 301b as closely as possible. After φ EQ transitions low, equalization device 304 turns off and half-bitlines 301a and 301b are allowed to float.
With the falling edge of /RAS, a row address (not shown) is latched into the address latches and at least the selected bank 201 enters the active cycle. For purposes of illustration, it will be assumed that row X 0 is being accessed. Therefore, after decoding, wordline X 0 (an even wordline) and the reference wordline X REFOLD coupled to the complementary half-bitline 301b are charged. For discussion purposes, it is assumed that Cell O along wordline X 0 and column Y 0 (i.e. bitline 301 is associated with Column O) being read, and that Cell O is storing charge (a logic 1). Thus, with the turn-on of wordline X 0 , the charge on the capacitor Cell O slightly modifies/ influences the voltage on bitline 302a (whether the voltage on the bitline increases or decreases, depends on the digital state being detected/ sensed.) Also assume that the reference voltage V REF and the capacitance of the C REFOLD are selected to set the voltage on half-bitline 301b at voltage between Vcc and Vas. The voltage half-bitline 301b is selected to provide a voltage at Node B which can be accurately differentially amplified against the voltage of Node A, even if the voltage on the storage Cell O has deteriorated. This may be for example V cc/2 , V cc/3 or 2V cc/3 . The actual selection process is well known in the art and is dependant on a number of factors, such as the fabrication process.
According to the principles of the present invention, a stepped signal φ SB1 controls the current through bottom transistor 306 and subsequently through the differential pair transistors 307a and 307b. In the initial step, the current through bottom transistor 306 is slowly increased. This is during the period when the voltage difference between Node A and Node B is very small since substantially no amplification has taken place. As bottom transistor 306 slowly turns on, the voltage separation at Nodes A and B is gradually separated (towards V cc and V ss ).
In the preferred embodiment, signal φ SB1 includes a second step during which speed are amplification are the key considerations. In other words, during the second step, bottom transistor 306 is rapidly turned on to completion to fully drive Nodes A and B towards the rails (in this case a logic 1 was read from Cell O and therefore Node A is driven high and Node B is driven low). Preferably, the second step starts approximately when Nodes A and B are 100 mV apart. It should be noted that, while two steps are shown in the preferred embodiment of FIG. 4, can be also stepped in three or more steps, as needed for a smooth, accurate splitting of the voltages at Nodes A and B.
Once the differential amplification of the voltage difference between half-bitlines 301a and 301b is substantially complete, the active pull up is activated and then the column decoders for the given bank are activated and the access performed.
At least two substantial advantages are achieved by gradually turning-on bottom transistor 306, in view of the prior art in which the bottom transistor is turned-on in a single, fast step. First, during the initial step, the risk of mislatching, which otherwise may happen if the bottom transistor is quickly turned-on during the time the voltage difference between Node A and Node B is very small, is substantially reduced. Second, during a fast turn-on, parasitic capacitances in the bottom transistor can couple noise within the sense amplifier and consequently cause mislatching. Among other things, a single large bottom transistor 306 is typically provided per bank; the gate to drain overlap capacitance in such devices being substantial can cause mislatching stated above. By stepping the turn-on of the bottom transistor, these parasitic effects can also be substantially reduced.
FIG. 5 depicts a second sense amplifier configuration according to the principles of the present invention. In this embodiment, a second amplifier stage 400 is provided. Second stage 400 includes differential pair of transistors 401a and 401b and a bottom transistor 402. The gate of bottom transistor 402 is driven by signal (clock) φ SB2 , which is a stepped signal generated similar to φ SB1 , described in application Ser. No. 08/759,764, cited above. Similar to bottom transistor 306, with regards to transistors 307, bottom transistor 402 controls the current through transistors 401a and 401b. This concept is not limited to dual-stage sense amplifier configurations, but may be further extended to three or more stages in a similar fashion.
In the preferred embodiment, the lengths of the transistor channels of differential amplifier transistors 307a and 307b of first stage 300 are at least twice that of the channels of differerential amplifier transistors 401a and 401b of second stage 400. The channel widths to length rates of transistors 307 and 401 are preferably on the same order, although the channel width may be varied to vary current drive.
The longer channels of transistors 301a and 301b provide for less gain, but advantageously minimize the threshold voltage and gain imbalance between the two devices. By minimizing the threshold voltage and gain imbalance, the potential for mislatching is further reduced. Higher gain and increased drive is provided by second state 400.
FIG. 6 is a conceptualized timing diagram similar to FIG. 3. Again, for illustrative purposes, its is assumed that Row 0 is being read, such that Wordline X 0 and X REFOLD are active. Also, it is assumed for discussion purposes that Node A is carrying a lower and Node B is carrying a higher residual voltage from the previous access cycle. Again, a logic 1 (high) has been written into Cell 0.
The access operation proceeds essentially in the same fashion as in the case of the single stage sense amplifier described above in FIGS. 3 and 4. In this case however, after clock φ SB1 turns on first stage 300, clock φ SB2 turns on the second stage. Advantageously, stage 300 splits apart the voltages at Nodes A and B with minimal risk of mislatching and then second stage 300 drives the nodes towards the respective rails. In the preferred embodiment, clock signal φ SB2 has two steps, with the second step not occurring until after the peak in clock φ SB1 .
According to a further feature of the present invention, the capacitor of each reference (dummy) cell, for example the illustrative capacitors C REFOLD or CR REFEVEN of FIGS. 3 and 5, may be formed by a plurality of capacitors. As discussed above, the reference cells set the voltage of the half-bitline of each half-bitline pair, which do not include the cells being read (for discussion purposes the "reference half-bits"). When the transistor of a given reference cell is turned on, the voltage on the reference half-bitline, floating close to its precharge level, is pulled down to the reference voltage through the reference cell capacitor. By setting the capacitance of the reference cell and/or the reference voltage V REF , the voltage on the reference bitline can be appropriately set.
The reference cell capacitors are formed by a plurality of either series or parallel capacitors, selected generally as a function of the desired reference voltage V REF . Preferably, these capacitors are fabricated as stacked capacitors, thereby providing a given capacitance in a smaller surface area.
FIG. 7A is a schematic diagram of a reference cell 701 embodying a reference cell capacitor C REF fabricated from two serial capacitors 701 and 702. In this embodiment the capacitors are preferably stacked. The configuration of FIG. 7A is most advantageously employed when a reference capacitor smaller than each of the storage cell capacitors is desired. This case may arise for example, when a fixed reference voltage, such as V REF =V cc has been selected. This concept can be extended to series of three or more capacitors.
In FIG. 7B, a reference cell 703 includes a capacitance C REF provided by parallel capacitors 703 and 703 (as with the example of FIG. 7A, this concept can be extended to three or more capacitors). In this case, capacitors 703 and 704 are preferably stacked to provide a smaller device geometry, although planar capacitors may also be used. The parallel capacitor approach is advantageously used when a larger capacitance and/or a small reference voltage V REF is desired. Further the multiple parallel capacitor approach can advantageously provide for circuit adjustability during manufacturing. For example, a plurality of capacitors can be fabricated in parallel and connected to the reference cell transistor through corresponding programmable devices, such as fuses. To adjust the cell capacitance, one or more selected ones of the parallel are disconnected by using the corresponding programmable device.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
|
A memory includes a bitline comprised of 2 half-bitlines with at least one cell coupled to each of the half-bitlines. A sense amplifier for detecting a voltage difference is coupled between the half-bitlines. A control signal controls the current through the sense amplifier. A method is provided for sensing data by precharging a pair of half-bitlines, activating a storage cell coupled to one half-bitline and reference cell coupled to its complement. A sense amplifier senses the voltage difference between the half-bitlines by initiating current flow through the sense amplifier during an intitial period and increasing the current flow during a subsequent period.
| 6
|
RELATED APPLICATIONS
[0001] This is a divisional application of U.S. application Ser. No. 11/424,027 filed Jun. 14, 2006, the entire disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to the field of bowling lane maintenance machines, in particular, to machines that can both clean and dress the lanes as they move along the surface thereof. It relates especially to a machine whose various operating functions are carried out in such a manner as to render the machine suitable for, but not necessarily limited to, battery operation so as to eliminate the need for an electrical supply cord connecting the machine to a source of electrical house current.
BACKGROUND AND SUMMARY
[0003] It is well known in the prior art to provide a lane machine that applies cleaning liquid to the lane at the front of the machine, picks up the liquid, surface grime and old dressing (oil) near the middle of the machine, and then applies a new film of oil to the cleaned surface at the rear of the machine as the machine is traveling along the length of the lane. In the past, such machines have required connection to house current through a long, unwieldy supply cord because the sequence of operations performed by the machine drew too much electrical current to make battery operation practical considering the significant number of lanes in a bowling facility.
[0004] In a machine constructed in accordance with the principles of the present invention the operational steps of the machine are such that battery operation can become a practical reality, without sacrificing quality and speed. Although the inventive operating steps are beneficial even if not incorporated into a machine that is battery-powered, the convenience of battery operation makes incorporating these principles into a battery-powered machine particularly attractive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a left front perspective view of a maintenance machine embodying the principles of the present invention with its top cover removed to reveal internal details of construction;
[0006] FIG. 2 is a right rear perspective view of the machine;
[0007] FIG. 3 is a right front perspective illustration of certain internal components of the machine with walls and other structures removed for clarity;
[0008] FIG. 4 is a left rear perspective illustration of certain internal components of the machine with walls and other structures removed for clarity;
[0009] FIG. 5 is a right side elevational view of the machine with the near sidewall thereof removed to reveal internal details of construction;
[0010] FIG. 6 is an enlarged, fragmentary right side elevational view of the machine illustrating the action of the squeegee blades as they engage the lane during forward travel of the machine;
[0011] FIG. 7 is an enlarged, fragmentary right side elevational view of the machine similar to FIG. 6 but illustrating the machine stopped at the end of its forward travel with the squeegee assembly passed beyond and overhanging the edge of the pin deck to flip moisture off the squeegee assembly;
[0012] FIG. 8 is an enlarged, fragmentary right side elevational view of the machine similar to FIG. 6 but illustrating the squeegee assembly in a raised position; and
[0013] FIGS. 9-13 are block diagrams of the different portions of the electrical system of the machine.
DETAILED DESCRIPTION
[0014] The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments.
[0015] The machine 10 illustrated in the drawings is similar in many respects to the machine disclosed in U.S. Pat. No. 5,729,855 and U.S. Pat. No. 6,939,404. Accordingly, the '855 and '404 patents are hereby incorporated by reference into the present specification. In view of the full disclosure in the '855 and '404 patents of the construction and operation of the lane machine, the construction and operation of the machine 10 will be described only generally herein.
[0016] The machine 10 has a cleaning system denoted broadly by the numeral 12 and located generally in the front of the machine. A dressing (preferably oil) application system is denoted broadly by the numeral 14 and located generally in the rear portion of the machine. These two systems perform their functions as the machine is propelled down the lane and back by lane-engaging drive wheels 16 and 18 fixed to a transverse shaft 20 that is powered by a drive motor 22 (Baldor 24 VDC model 24A531Z019G1) and a chain and sprocket assembly 24 . A conventional proximity sensor speed tachometer 25 ( FIG. 9 ) is coupled with the end of drive shaft 20 .
[0017] The oil application system 14 includes an applicator roll 26 (hereinafter sometimes referred to as the “buffer”) disposed for engaging the lane surface, a reciprocating oil dispensing head 28 that travels back and forth across the width of the lane above buffer 26 , and a brush assembly 30 between buffer 26 and dispensing head 28 for receiving oil from head 28 and delivering it to buffer 26 . Buffer 26 is rotatably driven by a buffer motor 31 (Baldor 24 VDC model 24A532Z046G1) ( FIG. 10 ). Buffer 26 pivots up and down, in and out of contact with the bowling lane surface by way of linkage 27 operated by a buffer up/down motor 29 (Merkle Korff 31 RPM 24 VDC model S-3727-87D) ( FIG. 12 ). In the down position, buffer 26 operates a buffer down limit switch 21 and operates a buffer up limit switch 23 in the up position.
[0018] Details of the construction and manner of use of brush assembly 30 are disclosed in U.S. Pat. No. 7,056,384 titled “Strip Brush Bowling Lane Dressing Application Mechanism”, which is hereby incorporated by reference herein. Oil application system 14 additionally includes a reservoir 32 , a positive displacement pump (not shown) (FMI model RHOCKC Lab Pump Jr.) having a motor 33 ( FIG. 10 ) (Dayton 24 VDC model3XE19) for supplying oil from reservoir 32 to dispensing head 28 , and a three-way valve 35 ( FIG. 9 ) for controlling the flow of oil. In a recycle position valve 35 recycles oil back to reservoir 32 , and in a delivery position valve 35 delivers oil from pump 33 to dispensing head 28 .
[0019] Oil dispensing head 28 is mounted for reciprocation along a transverse guide track 34 extending between the sidewalls of the machine. An endless drive belt 36 is secured to head 28 and has its opposite ends looped around a pair of pulleys 38 and 40 , the pulley 40 being operably coupled with a reversible motor 42 (Crouzet 24 VDC model 808050Y07.66Z) to provide driving power to belt 36 and thus propel dispensing head 28 along track 34 . A pair of left and right sensors in the form of proximity switches 44 and 46 adjacent opposite ends of the path of reciprocal travel of dispensing head 28 are operable to sense the presence of dispensing head 28 as it reaches the limits of its path of travel so as to signal the motor 42 to reverse directions and drive dispensing head 28 in the opposite direction along track 34 .
[0020] The pulley 38 is fixed to a long fore-and-aft extending shaft 48 disposed just outboard of the right sidewall of the machine. Near its rear end, just forwardly of pulley 38 , shaft 48 is provided with a notched wheel 50 whose rotation is sensed by a sensor 52 . An output from sensor 52 is sent to the control system of the machine (described in more detail below) for the purpose of determining the precise location of the oil dispensing head 28 across the width of the machine and the bowling lane. Such location is coordinated with a particular lane oil pattern that has been programmed into the control system of the machine so that oil dispensing head 28 may be actuated to precisely dispense oil at predetermined locations along its path of reciprocation.
[0021] Distance down the lane is determined by a pair of lane-engaging wheels 53 ( FIGS. 3 , 4 and 5 ) located just in front of the rear wall of the machine. Wheels 53 are fixed to a common cross shaft 54 that rotates a notched wheel 55 ( FIG. 4 ) via a chain drive 56 ( FIG. 3 ). The number of revolutions of notched wheel 55 is detected by a sensor 57 ( FIG. 4 ) that sends a signal to the control system of the machine.
[0022] The cleaning system 12 includes one or more cleaning liquid dispensing heads 58 that reciprocate across the path of travel of the machine as it moves along the lane. While system 12 may also include one or more pressurized spray nozzles as in conventional machines, in a preferred embodiment no such conventional spray nozzles are utilized. In the particular embodiment disclosed herein, only a single dispensing head 58 is utilized, such head 58 traveling essentially the full transverse width of the machine to the same extent as the oil dispensing head 28 .
[0023] Dispensing head 58 includes a vertically disposed, depending discharge tube 60 provided with a tip 62 that is located close to the lane surface. In one form of the invention, tip 62 is not in the nature of an atomizing nozzle but is instead configured and arranged to emit liquid in a fairly coherent stream so that a bead of cleaning liquid is laid down on the lane surface. One suitable tip 62 for carrying out this particular non-atomizing function is available from the Value Plastics Company of Fort Collins, Colo. as part number VP S5401001N. Other types of tips (not shown) that atomize, breakup or diffuse liquid supplied to the tip may also be utilized where broader surface area coverage by the cleaning liquid is desired. In either case, tip 62 is preferably provided with an internal check valve (not shown).
[0024] Cleaning system 12 further includes a guide track 64 attached to the front wall of machine 10 that slidably supports dispensing head 58 for its reciprocal movement. Track 64 extends across substantially the entire width of machine 10 to the same extent as the track 34 associated with oil dispensing head 28 . An endless drive belt 66 is attached to dispensing head 58 for providing reciprocal drive thereto, the belt 66 at its opposite ends being looped around a pair of pulley wheels 68 and 70 respectively.
[0025] Although pulley 68 may be driven in a number of different ways, including by its own separate drive motor, in a preferred form of the invention pulley 68 is fixed to the forwardmost end of shaft 48 from pulley 38 so that both dispensing heads 28 and 58 are driven by the same reversible motor 42 . Consequently, both oil dispensing head 28 and cleaning liquid dispensing head 58 are reciprocated simultaneously by motor 42 when the latter is actuated. However, it will be noted that oil dispensing head 28 and cleaning liquid dispensing head 58 reciprocate in mutually opposite directions due to the fact that oil dispensing head 28 is secured to the upper run 36 a of its drive belt 36 while cleaning liquid dispensing head 58 is secured to the lower run 66 b of its drive belt 66 .
[0026] Cleaning system 12 further includes a cleaning solution reservoir 72 at the rear of machine 10 . A supply line 74 leading from reservoir 72 is coupled in flow communication with a reversible peristaltic pump 76 (Barnant 24 VDC model D-3138-0009). An outlet line 80 from pump 76 leads to discharge tube 60 of dispensing head 58 for supplying cleaning liquid to head 58 . A cleaner control 82 ( FIGS. 10 and 11 ) is electrically connected to cleaner pump 76 for adjusting the speed of pump 76 , and thus the amount of cleaner discharged by head 58 .
[0027] Because pump 76 is preferably a peristaltic pump, it supplies liquid to dispensing head 58 in constant volume slugs or squirts that enable the cleaning liquid to be very precisely and accurately metered onto the lane surface. Furthermore, it permits the supply of liquid to dispensing head 58 to be essentially instantaneously stopped and started, which, in conjunction with the control valve, affords precise, board-by-board control over the pattern of cleaning liquid applied to the lane surface by dispensing head 58 .
[0028] Cleaning system 12 additionally includes a wiping assembly 88 immediately behind cleaning liquid dispensing head 58 . Assembly 88 includes a web 90 of soft material such as duster cloth looped around a lower compressible back-up member 92 in the nature of a roller that extends across the full width of the machine. Cloth 90 is stored on a roll 94 and is paid out at intervals selected by the operator and taken up by a takeup roll 96 . Wiping assembly 88 is similar in principle to the corresponding wiping assembly disclosed in U.S. Pat. No. 6,615,434, which patent is hereby incorporated by reference into the present specification. A duster unwind motor 95 ( FIG. 12 ) (Merkle Korff 9 RPM 24 VDC S-3828-87D) is coupled with roll 94 and, when activated, rotates roll 94 to let out slack in the cloth, allowing backup member 92 to gravity to the lane surface. A duster windup motor 97 ( FIG. 12 ) (Merkle Korff 9 RPM 24 VDC S-3828-87D) is coupled with takeup roll 96 and, when activated, rotates roll 96 to raise backup member 92 off the lane surface.
[0029] A further component of cleaning system 12 comprises a vacuum pickup head 98 located behind wiping assembly 88 . Vacuum pickup head 98 extends essentially the full width of machine 10 and includes a squeegee assembly 99 comprising a pair of resilient, squeegee-type blades 100 and 102 that assist in picking up the thin film of cleaning liquid left on the lane surface after the wiping assembly 88 has acted upon the liquid. Lift linkage 101 is connected to a squeegee lift motor 103 ( FIG. 12 ) (Merkle Korff 31 RPM 24 VDC S-3727-87D) and is operably coupled with suction head 98 and squeegee assembly 99 for moving the same between an operating position in engagement with the lane as shown in FIGS. 5 , 6 and 7 and a raised position out of engagement with the lane as shown in FIG. 8 . A large vacuum hose 104 leads from pickup head 98 to a holding tank 106 for storing liquid picked up by head 98 . Vacuum pressure within holding tank 106 is obtained by means of a vacuum motor 107 (Ametek 24 VDC model 116155-00) ( FIG. 10 ) coupled with tank 106 .
[0030] FIGS. 9-12 are block diagrams illustrating various portions of the control system 108 of machine 10 . Control system 108 includes, in addition to the electrical components already mentioned above, controller 110 (programmable logic controller Omron model CPM2A), drive motor control 112 , printed circuit board 114 , and control relays CR 1 , CR 2 , CR 3 , CR 4 , CR 5 , CR 6 , CR 7 , CR 8 , CR 9 , CR 10 , CR 11 , and CR 12 . Control system 108 further includes start switch 116 ( FIG. 9 ) and an emergency stop switch 117 ( FIG. 13 ).
[0031] An electrical power supply system 120 for machine 10 is illustrated in FIG. 13 , portions of system 120 also being visible in FIGS. 1-12 . In a preferred embodiment of the invention, the heart of power system 120 comprises a pair of series-connected, 12 VDC rechargeable storage batteries 122 (EnerSys Energy Products model Odyessey PC925) that jointly provide up to 24 volts DC power to operating components of the machine. Batteries 122 are connected to a forty amp charger 124 (Iota charger model DLS-27-40 with IQ Smart Charge Controller) that, in turn, is connected to a receptacle 126 ( FIG. 1 ) on the left sidewall of the machine. Receptacle 126 may be connected to a 120 VAC outlet in the bowling center using an electrical supply cord (not shown) in order to recharge batteries 122 from time-to-time, or to run the machine on 120 VAC power supply. As is well understood by those skilled in the art, charger 124 converts 120 VAC power from the supply cord to 24 VDC power for recharging batteries 122 and/or for operating the 24 VDC operating and control components of the machine. Preferably, a constant voltage regulator 128 (Solar Converters Inc. model CVP 12/24-15) is interposed between batteries 122 on the one hand and dispensing head motor 42 , oil pump motor 33 , buffer motor 31 , three-way valve 35 , and drive motor 22 on the other hand to maintain constant voltage to such components.
Operation
[0032] The operation of machine 10 is controlled by way of the programmed operating controller 110 . Although machine 10 may be selectively operated through appropriate switches to clean the lanes only, or to oil the lanes only, in the following example machine 10 is operated to both clean and oil the lanes.
[0033] Initially machine 10 is placed on the approach of a bowling lane just behind the foul line. The operator presses start switch 116 one time, which initiates the sequence of maintenance operations. A variety of lane oil patterns can be selected by way of the key pad and display 130 ( FIG. 1 ) as is conventional. The duster unwind motor 95 comes on at this time to dispense a new section of cloth, but if the normally open contacts of duster up switch 134 do not open up, there will be a “duster empty” error displayed. The squeegee assembly 99 will move down and stop when the normally open contacts of down switch 132 close. If the switch contacts do not close, there will be a “squeegee did not lower” error displayed. The oil pump 33 also turns on.
[0034] The machine 10 is then pushed onto the lane and properly seated. The start switch 116 is pressed a second time and the dispensing heads motor 42 will start up and cause both heads 28 and 58 to begin moving. Oil dispensing head 28 moves from left to right, as the lane is viewed from the foul line looking toward the pin deck, while cleaner head 58 moves from right to left.
[0035] Cleaner pump motor 76 is energized at the same time as heads motor 42 . Thus, as cleaner head 58 starts to move, it also starts to apply cleaner instantly to the lane and does not stop until the last programmed “squirt distance” down the lane has been reached. When the oil head 28 reaches the right board edge proximity switch 46 , the moving heads 28 , 58 will reverse their directions and oil head 28 will begin to apply the first stream of oil.
[0036] The oiling head 28 is now moving in a right-to-left direction, while cleaner head 58 is moving in a left-to-right direction. When oiling head 28 reaches the left board edge proximity switch 44 , the heads motor 42 will reverse, at which time buffer motor 31 starts up and drive motor 22 is energized to start the machine moving down the lane. Vacuum motor 107 has remained in an “off” condition during this initial startup phase, but after machine 10 has traveled about two feet down the lane, vacuum motor 107 turns on. It is also to be noted that after start switch 116 has been pressed a second time, machine 10 will start a clock (not shown) to record the total amount of run time on the display 130 . The total amount of time the three-way valve 35 dispenses oil for each lane is also shown in the display 130 .
[0037] As machine 10 travels forward down the lane, the oiling and cleaning heads 28 , 58 continue to operate, applying oil and cleaner. The board-counting sensor 52 monitors the positions of the moving heads 28 , 58 . If the motion is interrupted, an error message will be displayed.
[0038] During movement of the machine 10 down the lane, the lane distance sensor 57 counts inches traveled and monitors movement of the machine. If travel is interrupted, an error message will be displayed. The speed of machine 10 is also being monitored by the speed tack 25 and is displayed continuously. As the machine continues to move forward, speeds will change (through a drive motor speed control (KB model KBBC-24)) and oil and cleaner will continue to be dispensed to the lane as programmed. As the machine approaches the applied oil distance in accordance with the selected program, the oil pump motor 33 turns off but the buffer motor 31 stays on so buffer 26 continues to buff oil onto the lane.
[0039] When the oil distance is reached, buffer 26 stops and buffer lift motor 29 is energized to raise buffer 26 off the lane until buffer up limit switch 23 is operated. If the contacts for raising buffer 26 do not close, there will be an error message displayed. If the up switch 23 sticks closed when it should be open, a “brush down” error message will be displayed.
[0040] Additionally, when the oil distance has been reached machine 10 will shift into high speed and continue to travel toward the pin deck. As the machine approaches the pin deck, the programmed distance for the application of cleaner will be reached, causing cleaner pump motor 76 to be turned off and heads motor 42 to be deenergized so as to stop movement of dispensing heads 28 , 58 . At the same time the machine will down-shift to low speed to reduce its momentum into the pin deck.
[0041] When machine 10 enters the pin deck, the duster windup motor 97 will turn on and start to windup the cloth to raise the backup member 92 . The normally open contacts of the duster up switch 134 will close to turn off the duster windup motor 97 . If the contacts do not close, there will be a “duster did not wind up” error message displayed.
[0042] Machine 10 then continues the rest of its travel with squeegee assembly 99 engaging the lane in the manner illustrated in FIG. 6 before coming to a stop at a point where the front of the machine, including squeegee assembly 99 , travels off and overhangs the edge 136 of the pin deck 138 as illustrated in FIG. 7 . Drive motor 50 has been shut off. This allows the resilient blades 100 , 102 of squeegee assembly 99 , which have been flexed rearwardly as the machine travels forwardly down the lane, to flip resiliently forwardly in a quick snapping action and throw off cleaning liquid moisture that may otherwise cling to the blades. Squeegee lift motor 103 is then activated to lift squeegee assembly 99 and suction head 98 into a raised position as illustrated in FIG. 8 . Squeegee lift motor 103 stops when the normally open contacts of the squeegee up limit switch 136 close. If the contacts do not close, an error message will be displayed.
[0043] Drive motor 50 is then driven in reverse for a short duration, causing machine 10 to move in the reverse direction toward the foul line and stop after moving four inches. The squeegee assembly 99 and suction head 98 are then lowered to re-engage the blades 100 , 102 with the pin deck 138 . Drive motor 50 is then driven in forward to advance the machine forwardly four inches, whereupon it stops to once again cause squeegee assembly 99 to overhang the edge 136 of pin deck 138 . Blades 100 , 102 snap forwardly to flip off any excess moisture. The squeegee assembly 99 then lifts.
[0044] Drive motor 50 now reverses to cause machine 10 to move in the reverse direction toward the foul line at high speed. At the same time vacuum motor 107 is turned off and cleaner pump motor 76 is run in reverse for one second to help reduce the possibility of dripping cleaner out of tip 62 of the cleaner head 58 .
[0045] As machine 10 travels in reverse, the lane distance sensor 57 counts inches traveled and continuously monitors movement of the machine. If travel is interrupted, an error message will be displayed. As the machine reaches the oil distance, buffer 26 begins to lower and stops in its down position when the normally open contacts of the buffer down switch 21 close. If the contacts do not close, an error message is displayed. If the down switch 21 sticks closed when it should be open, a “brush up” error message will be displayed.
[0046] Buffer motor 31 is then energized, causing buffer 26 to begin buffing as the machine continues its travel in reverse. The oil head 28 starts dispensing oil again when the machine reaches the first “reverse load” distance on the lane according to the selected oil pattern program. The machine progressively down-shifts to lower speeds as it continues toward the foul line. When the last reverse load of oil has been applied, the oil head 28 stops and parks. Once the machine reaches the foul line, drive motor 50 is deactivated, causing the machine to stop and await operator attention to move it to the approach of the next lane.
[0047] If at any time during its travel up and down the lane machine 10 stops and displays a “LOW BATTERY OR E-STOP PRESSED” warning, this means either battery voltage has dropped below seventeen volts or the emergency stop switch 117 ( FIG. 13 ) has been pressed. In either case, the machine will need to be returned to the foul line and connected to the 120 VAC house power supply for recharging or running on house current using the electrical power supply cord.
[0048] The constant voltage regulator 128 plays a significant role in the machine 10 if it is battery-powered (there is no requirement that the machine functions as above described be incorporated into battery-powered machines. However, significant ease-of-use benefits are achieved when they are.) Because the constant voltage regulator 128 is capable of maintaining a constant voltage of twenty-four volts to the key functions of the machine even though the batteries may run down to twenty or twenty-one volts, there is no gradual loss of performance. The machine shows no signs of losing battery power until the voltage drops so low (such as seventeen volts) that the controller 110 simply shuts down and the machine stops and displays the warning. The dispensing head motor 42 , oil pump motor 33 , buffer motor 31 , three-way valve 35 , and drive motor 22 all operate from the constant voltage regulator 128 .
[0049] The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.
|
A bowling lane maintenance machine has its operating functions designed and controlled in such a manner that the machine may be battery-operated without loss of performance. Included in the operation are special movements of the machine at the pin deck to flick moisture off blades of the squeegee assembly and limited activation of the vacuum motor to reduce battery drain.
| 0
|
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing sleeved clothing articles on a two bed flat knitting machine and, more particularly, to a process for producing sleeved clothing articles on a two bed flat knitting machine wherein the clothing article is a complete knitted article.
A clothing article producable on a flat knitting machine can be produced with sleeves and a torso portion by initially using different yarn guides for the sleeves and the torso portion to produce tubular knits for these clothing article components and then, subsequently, to connect these components to one another to make an integral single piece article. There are various possibilities for the formation of the sleeves and the sleeve formation process significantly impact the look of the finished clothing article.
SUMMARY OF THE INVENTION
The present invention provides three variations of a process for for interconnecting the sleeves and the torso portion of a sleeved clothing article during production of the sleeved clothing article on a two bed flat bed knitting machine. One variation of the process provides sleeves having seam regions extending perpendicularly to the shoulders; another variation provides sleeves having seam regions extending at an angle to the shoulders; and a further variation provides raglan sleeves.
The three variations of the process of the present invention commonly share the characteristic that the sleeved clothing article is of the type in which the two sleeves and the torso portion are finished as tubular knits with separated yarn guides and the stitches are disposed on the needle beds of the flat knitting machine such that the needles of one respective needle bed are not occupied when the needles of the other needle bed are occupied with stitches.
The advantage of the process of the present invention is a reduction in the number of yarn suspending steps necessitated by the stitch lessening requirements as compared with known processes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic front plan view of a pullover having respective seam regions perpendicular to the shoulder interconnecting the sleeves and the torso portion of the pullover;
FIGS. 2.1-2.3 is a schematic representation of the knitting sequence for creating the seam regions interconnecting the sleeves with the torso portion of the pullover shown in FIG. 1;
FIG. 3 is a schematic view of a pullover having respective seam regions extending at an angle to the shoulder and interconnecting the sleeves and the torso portion of the pullover;
FIGS. 4.1-4.5 is a schematic representation of the knitting sequence for creating the seam regions interconnecting the sleeves with the torso portion of the pullover shown in FIG. 3;
FIG. 5 is a schematic view of a pullover having raglan sleeves; and
FIGS. 6.1 and 6.2 is a schematic representation of the knitting sequence for creating a seam region of the pullover shown in FIG. 5 interconnecting the sleeves with the torso portion thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIG. 1, a pullover 10 has a torso portion 12 and a pair of sleeves 13 and 14. A seam region 15 and 16 interconnects the sleeves 13 and 14, respectively, and the torso portion 12 and is indicated by a broken line extending generally perpendicularly to the shoulders 17 and 18 of the pullover 10.
FIG. 2 schematically shows the knitting sequence accomplished by a flat knitting machine in creating the seam 15 and 16 between the sleeves 13 and 14 and the torso portion 12 in accordance with one variation of the process of the present invention. The areas for the needle beds for the left and right sleeves are shown as the darker shaded areas and the needle area for the torso portion is shown as the relatively lighter shaded areas. All stitch rows on the front and rear needle beds are knitted with the same yarn guide. The relationship of the knitted rows of the torso portion to the knitted rows of the sleeves is 2:1. This relationship can be varied without departing from the scope of the process of the present invention.
In row 1, a stitch row is knitted by a first knitting system in a carriage or shuttle direction from right to left with the needles b25-b1 of the rear needle bed in the region of both sleeves and the torso portion. In row 2, the stitches of the right sleeve on the needles b25-b21 of the rear needle bed are transferred to the needles B25-B21 of the front needle bed and the stitches of the left sleeve on the needles A5-A1 of the front needle bed are transferred to the needles a5-a1 of the rear needle bed.
In row 3, via a needle exchange, the following needles of the front needle bed are transferred to needles of the rear needle bed: B25-B21 to b22-8 and the following stitches on the needles in the rear needle bed are transferred to needles in the front needle bed: a1-a5 to A4-A8. Thereafter, after a return movement of the needles, in row 4, the stitches of the needles a19-a22 on the needles A19-A22 of the rear needle bed are transferred to the front needle bed and the stitches of the needles B4-B7 of the front needle bed are transferred to the needles b4-b7 of the rear needle bed. In this manner, the cover- and lessening steps of shaping the sleeves into interconnection with the torso portion is completed.
In row 5, in a carriage or shuttle direction from left to right, a stitch row is created with the needles A4-A21 on the front needle bed in the area of the left sleeve and the torso portion. Thereafter, in row 6, in a reverse carriage or shuttle direction, a stitch row is created with the needles A21-A6 of the front needle bed in the area of the torso portion and in row 7. in a carriage or shuttle direction from left to right and with the needles A6-A22 again on the front needle bed in the area of the torso portion and the right sleeve. In row 8, in reverse carriage or shuttle direction and with the needles b22-b6 on the rear needle bed in the area of the right sleeve and the entire torso portion, a stitch row is built. Thereafter, in row 9, in a carriage or shuttle direction from left to right and with the needles b6-b20 in the area of the torso portion, a stitch row is created on the rear needle bed. Subsequently, in row 10, in a carriage or shuttle direction from right to left and with the needles b20-b4 in the area of the torso portion and the left sleeve, a stitch row is created on the rear needle bed. In row 11, in a carriage or shuttle direction from left to right and with the needles A4-A22 in the area of both sleeves and the torso portion, a stitch row is built on the front needle bed. The just described steps can be repeated until the torso portion is completed and the sleeves are completely stitched in with the torso portion.
FIG. 3 shows another pullover 20 having a torso portion 22 and two sleeves 23 and 24, whereby the seam regions 25 and 26 between the sleeves 23 and 24 and the torso portion 22 extends at an angle or slant to the shoulders 27 and 28 of the pullover 20.
FIG. 4 schematically shows the knitting sequence for a flat knitting machine to create the pullover 20 in accordance with another variation of the process of the present invention. Again, all of the stitch rows on the front and rear needle beds are knitted with the same yarn guide. The shaping of tubular knits on the torso portion and the thereon hanging sleeves is achieved through a lessening step process. In the rows 3-5, a lessening step process of the torso portion is executed and a lessening step process is executed in the rows 10-12, 17-19, and 24 and 26. The count of knitted stitch rows in between the lessening steps can vary as a function of the shaping of the pullover; the same is true for the count of the per step lessened stitches, as the slant of the seam between the torso portion and the sleeves is a function of this. In the example illustrated in FIG. 4, the relationship between the count of the torso portion lessening to the count of the sleeve lessening is 1:3. The higher the count of the sleeve lessening, the steeper the seam between the sleeves and the torso portion.
In row 1, a stitch row is created on the front needle bed by a first knit system in a carriage or shuttle direction from left to right with the needles A2-A33 and, subsequently, in row 2, in reverse carriage or shuttle direction and with the needles b32-b1 on the rear needle bed, a stitch row is created. To lessen the stitch count of the torso portion, in row 3, the stitches A2-A13 are suspended from the front needle bed to the rear needle bed and the stitches b21-b32 on the rear needle bed are suspended to the front needle bed. In row 4, after a needle bed movement, all of the stitches suspended on the rear needle bed in the area of the needles b1-b12 and a2-a13 are suspended to the needles B3-B13 and A4-A15. Additionally, all of the stitches on the front needle bed in the area of the needles B21-B32 and A22-A33 are suspended to the needles b19-b30 and a20-a31 of the rear needle bed. After a return movement of the needle beds, the stitches associated with the back portion of the tubular knit are suspended from the needles B3-B14 on the front needle bed to the needles b3-b14 of the rear needle bed and the stitches associated with the front portion of the tubular knit are suspended from the needles A22-A31 of the rear needle bed to the needles A22-A31 of the front needle bed. In this manner, the lessening process for the torso portion is completed.
Thereafter, two stitch rows are knitted in each of the rows 6-9 on the front needle bed with the needles A4-A31 and on the rear needle bed with the needles b3-b30. Subsequently, the lessening process for both sleeves commences starting from row 10. In this context, the stitches A4-A11 of the front needle bed are suspended to the needles a4-a11 in the rear needle bed and the stitches on the needles b23-b30 of the rear needle bed are suspended on the needles B23-B30 of the front needle bed. In row 11, after a needle bed movement, the stitches of the needles b3-b10 and a4-a11 of the rear needle bed are suspended to the needles B5-B12 and A6-A13 of the front needle bed. Additionally, the stitches on the needles B23-B30 and A24-A31 of the front needle bed are transferred to the needles b21-b28 and a22-a29 of the rear needle bed. In row 12, the stitches associated with the back portion of the knit are suspended from the needle B5-B12 of the front needle bed to the needles b5-b12 of the rear needle bed and the stitches associated with the front portion of the knit are suspended from the needles a22-a29 of the rear needle bed to the needles A22-A29 of the front needle bed.
In rows 13-16, two stitch rows are created in each row with the needle A6-A29 of the front needle bed and the needles b5-b28 of the rear needle bed. In this manner, the stitches of the needles A6-A11 of the front needle bed are suspended to the needles a6-a11 of the rear needle bed and the stitches on the needles b23-b28 of the rear needle bed are suspended to the needles B23-B28 of the front needle bed. Thereafter, in row 18, following a needle bed movement, the stitches on the needles b5-b10 and a6-a11 of the rear needle bed are suspended to the needles B7-B12 and A8-A13 of the front needle bed and the stitches of the needles B23-B28 and A24-A29 of the front needle bed are suspended to the needles b21-b26 and a22-a27.
Subsequently, there follows in row 19 a re-suspension of the back portion stitches on the needles 137-1312 of the front needle bed to the needles b7-b12 of the rear needle bed as well as a re-suspension of the stitches associated with the front portion from the needles a22-a27 of the rear needle bed to the needles A22-A27 of the front needle bed. In rows 20-23, two stitch rows are created on each of the rows on the needles A8-A27 of the front needle bed and needles b7-b26 of the rear needle bed. Thereafter, a lessening process is executed in the rows 24-26 for the sleeves. In this connection, in row 24, the stitches on the needles A8-A11 of the front needle bed are suspended to the needles a8-a11 of the rear needle bed and the stitches of the needles b23-b26 of the rear needle bed are suspended to the needles B23-B26 of the front needle bed. In row 25, after a needle bed movement, the stitches on the needles b7-b10 and a8-a11 of the rear needle bed are suspended on the needles B9-B12 and A10-A13 of the front needle bed. Additionally, the stitches on the needles B23-B26 and A24-A27 of the front needle bed are suspended on the needles b21-b24 and a22-a25. Thereafter, there follows in row 26 a re-suspension of the back portion stitches on the needles B9-B12 of the front needle bed to the needless b9-b12 of the rear needle bed and a re-suspension of the front portion stitches on the needles a22-a25 of the rear needle bed to the needles A22-A25 of the front needle bed. Subsequently, the steps for the rows 1-26 can be repeated until the sleeve has been completely knitted together with the torso portion.
FIG. 5 shows a pullover 30 knitted in accordance with a further variation of the process of the present invention and having a torso portion 32 and two raglan sleeves 33 and 34. The seam regions 35 and 36 of the sleeves 33 and 34 extend at a slant from the sleeve undersides to the collar portion 37 of the pullover 30. A knit process to produce such a raglan seam 35 or 36 is shown in FIG. 6. The seam connection is again achieved through a lessening process on the torso portion and the sleeves. In the rows 3-5 there is executed a lessening of the stitch count of the torso portion and, in rows 8-10, a lessening of the stitch count of the sleeves. The rows in between the knitted lessened rows can vary in count as a function of the tailoring of the pullover. The same is true for the count of the per step lessened stitches. The greater the difference in the count of the lessened stitches between the torso portion and the sleeves, the wider is then the lessened area.
In row 1, a stitch row is created over both sleeves and the torso portion on the front needle bed by a first knit system in a carriage or shuttle direction from left to right with the needles A2-A33. Thereafter, in row 2, in reverse carriage or shuttle direction, a stitch row with both sleeves and the torso portion is created with the needles b32-b1 on the rear needle bed. Also, in row 3, stitches on the needles A2-A8 of the front needle bed are suspended to the needles a2-a8 of the rear needle bed by a further knit system and stitches on the needles b26-b32 of the rear needle bed are suspended to the needles B26-B32 of the front needle bed. In row 4, after a needle bed movement, the stitches on the needles b1-b7 and a2-a8 of the rear needle bed are suspended to the needles B3-B9 and A4-A10 of the front needle bed. Also, the stitches B26-B32 and A27-A33 of the front needle bed are suspended on the needles b24-b30 and a25-a31 of the rear needle bed. There then follows, in row 5, a re-suspension of the stitches B3-B9 of the front needle bed to the needles b3-b9 of the rear needle bed and a suspension of the needles a25-a31 of the rear needle bed to the needles A25-A31 of the front needle bed.
Following this lessening of the torso portion, a stitch row is created in each of the rows 6 and 7 with the needles A4-A31 of the front needle bed and with the needles b3-b30 of the rear needle bed for, respectively, each of the sleeves and the torso portion. Thereafter, in row 8, to lessen the sleeves, the stitches of the needles A4-A6 of the front needle bed are suspended to the needles a4-a6 of the rear needle bed and the stitches on the needles b28-b30 of the rear needle bed are suspended to the needles B28-B30 of the front needle bed. Subsequently, in row 9, after a needle bed movement, the stitches of the needles b3-b5 and a4-a6 are suspended to the needles B5-B7 and A6-A8 of the front needle bed and the stitches of the needles B28-B30 and A29-A31 are suspended to the needles b26-b28 and a27-a29 of the rear needle bed. In row 10, there follows a re-suspension of the stitches of the needles B5-B7 of the front needle bed to the needles b5-b7 of the rear needle bed and of the stitches on the needles a27-a29 of the rear needle bed to the needles A27-A29 of the front needle bed. The steps 1-10 can be repeated until the sleeve is completely knitted together with the torso portion.
|
Three variations of a process for interconnecting the sleeves and the torso portion of a sleeved clothing article during production of the sleeved clothing article on a two bed flat bed knitting machine include one variation of the process which provides sleeves having seam regions extending perpendicularly to the shoulders; another variation which provides sleeves having seam regions extending at an angle to the shoulders; and further variations which provides raglan sleeves.
| 3
|
FIELD OF THE INVENTION
The present invention relates to a section of composite material intended to constitute a prosthetic element, and particularly a tooth post, as well as to a process for manufacturing such a section.
BACKGROUND OF THE INVENTION
It is known that, in the dental domain, in order to ensure the perennity of the dental substance of a tooth, metal posts are called upon, which are screwed or sealed therein. Such metal posts present a certain number of drawbacks, which are principally associated with the great difference which exists between the mechanical characteristics of these posts and those of the dentine in which they are disposed.
In order to avoid such drawbacks, it has been proposed to employ posts made of composite material, constituted in particular by a matrix of bio-compatible resin, and particularly an epoxy resin, in which carbon or glass fibers are embedded.
In certain embodiments, the fibers are longitudinal fibers which extend over the whole length of the post and which are under equal tension therein. The posts thus constituted, by reason of their mechanical characteristics close to those of the dentine, considerably reduce the drawbacks set forth hereinabove.
However, such posts present the drawback of being transparent to X-rays, so that their positioning is particularly difficult to establish with the aid of the conventional apparatus available to practitioners.
These posts are usually manufactured by pultrusion, i.e. by a process of extrusion in which both the fibers, particularly the carbon or glass fibers, and a resin matrix are passed in the same die at the same time, the fibers being, all along the operation, maintained under tension. This operation of pultrusion is sometimes difficult to carry out by reason of the problems of obturation of the die of the extruder which occur during operation.
In the prior state of the art, products, or charges, are known, which are added to the dental reconstitution pastes, in order to give them a certain opacity to X-rays. U.S. Pat. No. 4,503,169 thus proposes to that end to include zirconium, oxides in dental reconstitution pastes.
Patent GB-A-2 028 855 also discloses a settable composition exempt of mercury based on a carboxylic polyacid and which contains, inter alia, filling elements which may possibly comprise fibrous elements which may be coated with metal oxides capable of reacting with the carboxylic polyacid in order to promote bond with the matrix.
SUMMARY OF THE INVENTION
The present invention has for its object to propose a means for solving both the problems associated with carrying out the pultrusion operation and those connected with the lack of opacity of the prosthetic elements used in the dental art, which are constituted by composite materials based on resins, particularly epoxy resins, reinforced by fibers, particularly long, unidirectional carbon fibers.
The present invention thus has for an object a section of composite material intended to constitute a prosthetic element, particularly a dental post, comprising a core, constituted by longitudinal fibers, which is embedded in a matrix of resin, characterized in that this resin matrix contains at least one metal oxide.
Applicants have in fact observed that the implementation of pultrusion was largely facilitated when metal oxides were added to the resin matrix. In fact, the added metal oxide behaves like a sliding agent which reduces the adhesion of the resin and promotes flow of the product in the die of the extruder. Implementation is even easier when the metal oxides are in the form of granules or microballs. It is also possible, in order to facilitate the pultrusion operation further, to use metal oxides which are contained in microballs, particularly glass microballs.
Under these conditions, the metal oxides introduced in the resin perform two functions, namely a first function of slide provoking the extrusion and a second function of opacity.
As set forth hereinafter, when one is obliged to add a relatively large quantity of metal oxides in the resin, oxides contained in glass microballs are totally or partly employed. A plurality of particles of oxides may, moreover, be grouped in the same microball.
According to the invention, the metal oxide or oxides chosen, necessary for giving the desired opacity to the prosthetic element, may be associated, wholly or partly, with the fibers, i.e. it is either introduced therein or disposed on their surface so as to constitute a coating adhering well thereto. In this last embodiment, the cohesion of the fibers with the resin is thus improved.
In an embodiment of the invention, the metal oxide presents a refraction index higher than the refraction index of the dentine. Such an embodiment of the invention is particularly interesting in that, with identical resultant overall opacity, the quantity of said metal oxide contained in the resin can be reduced, which avoids diminishing the mechanical qualities of the post. In addition, it is thus possible, for a given desired refraction index, to control the quantity of metal oxide used, in order to place in the post only the quantity which allows the sliding agent to act in optimum manner, which promotes the pultrusion operation.
The present invention also has for an object a process for manufacturing a section of composite material, intended to constitute a prosthetic element, and particularly a dental post, comprising a core constituted by longitudinal fibers, this core being embedded in a matrix of resin, characterized in that it comprises the steps consisting in mixing with said resin matrix at least one metal oxide, and in extruding the fibers and the resin matrix containing said metal oxide, while maintaining said fibers under equal tension.
In an embodiment of the invention, the metal oxides may be associated with the fibers, i.e. be introduced in the mass thereof or on their surface.
At least one of the metal oxides associated with the fibers may be identical to that, or to one of them, mixed with the resin matrix. Furthermore, the refraction index of the oxide used may advantageously be greater than the refraction index of the dentine.
In a particularly interesting embodiment of the invention, the fibers coated with metal oxides receive a specific bridging agent intended to promote bonding thereof with the resin matrix, this bridging agent being constituted, in the majority of cases, by silanes.
The coating of metal oxide may be made on the whole surface of the fibers, particularly by a thermic impregnation, when the melting temperature of the fibers is higher than that of the metal oxides. Under such conditions, the granulometry of the metal oxides has only little influence on the radio-opacity. The coating may also be made, particularly in the case of the melting temperature of the fibers being lower than that of the metal oxide, by employing a process of projection, and in particular a plasma projection process.
According to this embodiment, the fibers coming from storage reels traverse an impregnation tank where they are impregnated with metal oxide in the molten state, then these fibers are drained and dried in a second enclosure of which the temperature progressively decreases.
BRIEF DESCRIPTION OF THE DRAWINGS
A form of embodiment of the present invention will be described hereinafter by way of non-limiting example, with reference to the accompanying drawing, in which:
FIG. 1 is a schematic view illustrating a general embodiment of sections according to the invention.
FIG. 2 is a schematic view of a variant embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, dental posts are constituted by incorporating in a matrix constituted by a thermosettable resin, or a thermoplastic resin, metal oxides which are biocompatible, in order not to provoke problems of acceptation by the patient's organism. The quantity of metal oxide introduced in the resin is a function of the refraction index which it is desired to obtain. These oxides preferably present a refraction index higher than that of the dentine, and even than that of the osseous structure, and preferably much greater than them.
It is known that the refraction index of the osseous structure is of the order of 1.65 and that that of the dentine is of the order of 1.6. Under these conditions, for the dental prosthetic element to be detectable by X-rays, it must present a refraction index different from that of the dentine and/or the osseous structure, viz. it is slightly higher or lower than them. The refraction indices of the dental post must thus be either higher than 1.65 or lower than 1.6 if it is desired to be able to distinguish them both from the dentine or from the osseous structure.
The most interesting metal oxides which may thus be capable of being used in the implementation of the present invention are:
______________________________________ magnesium oxide MgO n = 1.74strontium oxide SrO n = 1.81calcium oxide CaO.sub.2 n = 1.89bariumoxide BaO n = 1.98BaO.sub.2 n = 1.98zinc oxide ZnO n = 2.01 to 2.03zirconium oxide ZrO.sub.2 n = 2.13 to 2.20titanium oxide TiO.sub.2 n = 2.61 to 2.90______________________________________
The quantity of metal oxide introduced in the resin depends on the refraction index which it is desired to give the post.
In a first step of the process according to the invention, the metal oxide chosen is firstly blended with a resin matrix, for example by mixing. In a second step, as shown in FIG. 1, a bundle of fibers 3, particularly carbon or glass fibers, which are stored on reels 5, are passed in a tank 1 containing the mixture of resin and chosen metal oxides. The assembly traverses a die 7 of an extruder 8 and, simultaneously to this extrusion, the fibers 3 are subjected to a tension by a system of drawing constituted in known manner by "caterpillars" 9, 9'. On leaving the die 7, the composite section obtained is polymerized. If such a section is intended to constitute dental posts, it is then cut to the desired length and possibly machined.
In a first example of embodiment of the invention, a mixture of epoxy resin with 25% by weight of barium oxide and 25% by weight of titanium oxide is made. Physically, the metal oxides introduced in the resin matrix are in the form of granules whose mean granulometry is less than the mean diameter of the fibers. The fibers used are high performance carbon fibers with a diameter of the order of 8 μm, which are preferably grouped together in tufts of 3000 to 6000 filaments. The diameter of the die 7 is such that a section with a diameter of about 2 mm is obtained on leaving the extruder 8. Such a section is particularly adapted to be used for making dental posts.
The radio-opacity of the section obtained has proved greater than that of the dentine, its refraction index being 1.69. If such a section is used as dental post, it is perfectly locatable in X-ray examinations when the tooth is observed towards the root.
In a second example of embodiment of the invention, a mixture of epoxy resin with 39% by weight of titanium oxide is made. Physically, the titanium fixed with the resin is, as before, in the form of microballs whose mean granulometry is of the order of 2 μm. The fibers used are high performance carbon fibers with a diameter of the order of 8 μm. The diameter of the die used is the same as previously.
Upon examination, the radio-opacity of the section obtained has proved to be much greater, not only than that of the dentine, but also than that of the osseous structure, and that of the enamel of the tooth (n=1.65), its refraction index being 1.82, so that such a section is locatable by X-rays even through the enamel of a tooth.
As mentioned hereinabove, it was observed, during the different implementations of the invention, that the passage of the product (i.e. of the assembly constituted on the one hand, by the mixture of resin and metal oxides and, on the other hand, the fibers) in the die of the extruder was rendered more difficult when the sections were of small diameter and necessitated large quantities of metal oxides in order to attain the desired refraction index.
In order to avoid this drawback, the fibers themselves are coated with a given metal oxide or with a mixture of several metal oxides. In such an embodiment, the fibers may possibly receive a prior treatment intended to promote catching thereof with the metal oxides with which it is desired to coat them. After such a coating, the fibers may be stored in a reel while awaiting their subsequent use. Such a modus operandi makes it possible, for a determined quantity of metal oxides necessary for ensuring the desired opacity, to reduce that mixed with the resin matrix, which diminishes the compactness of the resin/metal oxide mixture and at the same time improves the passage of the product in the die.
It is thus possible to obtain sections of composite material incorporating carbon fibers under equal tension which present high refraction indices, much higher than those of the adjacent osseous structure, which presents considerable interest in numerous medical applications such as for example articular implants, etc.
In order to coat the fibers with the metal oxides, they are preferably passed in a bath containing the molten metal oxides. When the melting temperature of a given oxide is higher than that of the fiber, which is particularly the case when it is desired to coat glass fibers with titanium oxide, a process of plasma projection of the metal oxide may be employed.
In a third example of embodiment of the invention, the proportions of titanium oxide and of barium oxide given in the first example are taken, but the barium oxide is deposited on the fibers and the titanium oxide is mixed with the resin. In this way, the fibers may be coated by hot immersion as the high value of the melting temperature of the titanium oxide is no hindrance, since the latter is mixed with the resin. It is thus possible, in this case, to use not only carbon fibers but also glass fibers since the melting temperature of the barium oxide is less than that of the glass.
According to the invention, the same metal oxide as that deposited on the fibers may be mixed with the resin matrix.
More than two metal oxides may of course be mixed with the resin. A fourth example of embodiment of the invention will be described hereinafter in which 8.5% by weight of zirconium oxide, 10.5% by weight of titanium oxide and 17.5% by weight of barium oxide are mixed with an epoxy resin.
The titanium and barium metal oxides are, in the present embodiment of the invention, introduced in the form of microballs. These oxides are both included in the same glass microball with a granulometry of the order of 20 to 40 μm. Zirconium oxide is in the form of granulates whose granulometry is of the order of a micrometer. The fibers used are high performance carbon fibers with a diameter of the order of 8 μm. The diameter of the die is such that a section with a diameter of 2 mm is obtained at the outlet of the extruder.
Upon examination, the radio-opacity of the section obtained proved to be slightly greater than that of the dentine, since its refraction index is 1.66. A simple dental radiograph of a section inserted in a tooth confirmed a radio-opacity of this section slightly greater than that of the dentine.
The metal oxides disposed in microballs proved to be particularly efficient sliding agents, which makes it possible to introduce them in large quantities in the resin without provoking packing at the level of the die of the extruder. For a given desired refraction index, their use makes it possible to control the quantity of metal oxide used, in order to place in the post only the quantity which allows the sliding agent to act in optimum manner, which promotes the pultrusion operation.
In order to improve adherence of the fibers, or the fibers coated with oxides, with the resin matrix, they may be sized prior to being introduced in the resin. Such sizing consists, in known manner, in making a surface treatment of the fibers, coated or not, with the aid of a "binding" agent whose role is to constitute a chemical bridging with the molecules of the resin matrix.
To that end, as shown in FIG. 2, fibers 3 stored on reels 5 are admitted in an enclosure 13 heated by resistors 15, where the metal oxides 17 are maintained in the molten state, then in a draining and drying enclosure 19 where the temperature decreases progressively. At the outlet of the enclosure 19, spray means 21 project onto the fibers the binding element chosen, and finally the treated fibers are wound on a storage reel 23.
The metal oxides may also be incorporated in the fiber itself For example, particularly in the case of glass fibers, the metal oxides may be introduced in the fibers during manufacture thereof.
The metal oxides may, in the same section, be both in the form of granules or microballs, and in a heterogeneous form. The majority will preferably be in the form of microballs.
|
A shaped member made of composite material for making a prosthetic element, particularly a tooth post, comprising a core of longitudinal fibers embedded in a resin matrix, and a method for making the member, are disclosed. The member is characterized in that the resin matrix contains at least one metal oxide.
| 0
|
CROSS REFERENCE TO RELATED PATENT APPLICATION
The present patent application claims the right of priority under 35 U.S.C. §119 (a)-(d) of German Patent Application No. 10 2006 000 822, filed Jan. 5, 2006.
BACKGROUND OF THE INVENTION
The invention relates to a process for the preparation of liquid, storage-stable isocyanate mixtures of low color number containing carbodiimide (CD) and/or uretonimine (UI) groups, the isocyanate mixtures obtainable by this process, the preparation of blends from these isocyanate mixtures with additional isocyanates, and to a process for the preparation of prepolymers containing isocyanate groups and of polyurethane plastics, and preferably polyurethane foams.
Isocyanate mixtures containing CD and/or UI groups can be prepared in a simple manner using the highly active catalysts from the phospholine series, and particularly the phospholine oxide series of catalysts. Such isocyanate mixtures are prepared by the processes as described in U.S. Pat. No. 2,853,473, U.S. Pat. No. 6,120,699 and EP-A-515 933.
The high catalytic activity of the phospholine catalysts, and specifically of the phospholine oxide catalysts, on the one hand is desirable in order to start up the carbodiimidization reaction under gentle temperature conditions. However, on the other hand, no process is known to date which ensures effective termination of the phospholine catalysis or phospholine oxide catalysis without limitation. The carbodiimidized isocyanates tend to after-react, i.e. they release gas as a result of evolution of CO 2 . This then leads to a build up of pressure, for example, in the storage tanks, and especially at higher temperatures.
There has been no lack of attempts to discover an effective means of terminating the phospholine catalysis. Various terminators are mentioned, for example, in the patent specifications DE-A-25 37 685, EP-A-515 933, EP-A-609 698 and U.S. Pat. No. 6,120,699. These terminators include, for example, acids, acid chlorides, chloroformates, silylated acids and halides of the main group elements. The termination of the phospholine catalysts with acids, which, for example, can also be in the form of acid chlorides, is not sufficiently effective.
According to the teaching of EP-A-515 933, CD/IU-containing isocyanate mixtures prepared by means of phospholine catalysis are terminated with at least an equimolar amount, and preferably from 1 to 2 times the molar amount, based on the catalyst employed, of e.g. trimethylsilyl trifluoromethanesulfonate (TMST). In practice, however, it has been found that CD/UI-containing isocyanates prepared in such a way are of only limited suitability for the preparation of prepolymers, i.e. reaction products of these CD/UI-containing isocyanates with polyols. The correspondingly prepared reaction products of polyols and the CD/UI-modified isocyanates tend to release gas, which can lead to a build up of pressure in the transportation tanks or to foaming during the handling of such products.
This problem can be by-passed by employing the silylated acid to terminate the phospholine catalyst analogously to EP-A-515 933 in higher molar equivalents (e.g. 5:1-10:1, based on the catalyst). In practice, however, it is then found that the resultant CD/UI-modified isocyanates have a significantly poorer color number. This then also applies to the prepolymers prepared therefrom.
This also applies if the phospholine catalyst is terminated with acids of the trifluoromethanesulfonic acid type, in accordance with U.S. Pat. No. 6,120,699. Prepolymers prepared from these CD/UI-modified isocyanates also have a considerably increased color number.
In the preparation of liquid, storage-stable isocyanate mixtures containing carbodiimide (CD) and/or uretonimine (UI) groups, significant variations are sometimes observed in the reactivity of the isocyanate employed, and therefore, in the reaction times required. An undesirable prolonging of the reaction time could be counteracted, for example, by increasing the reaction temperature and/or the catalyst concentration (and as a result the amount of terminator). However, this would be associated with process and/or safety risks and/or quality problems (such as, for example, increased color values).
Thus, the object of the present invention was to provide a simple and economical process for the preparation of liquid, storage-stable and light-colored isocyanate mixtures which contain carbodiimide and/or uretonimine groups that do not have the deficiencies referred to, and leads to liquid, storage-stable isocyanate mixtures of low color numbers.
SUMMARY OF THE INVENTION
The invention relates to a process for the preparation of organic isocyanates containing carbodiimide and/or uretonimine groups. This process comprises partially carbodiimidizing one or more organic isocyanates having a Hazen color number of ≦100 APHA, preferably ≦50 APHA, with one or more catalysts of the phospholine type, and one or more silylated acid amides; and subsequently terminating the carbodiimidization reaction. By means of this process, the required reaction time can be lowered or kept low and/or the amount of catalyst required can be reduced.
In accordance with the process of the invention, one silylated acid amide or also a mixture of several different silylated acid amides can be employed. In this context, the silylated acid amide can be added directly to the starting isocyanate or added to the reaction mixture during the carbodiimidization. The silylated acid amide is preferably added here in substance, i.e. without dilution, or as a masterbatch. A suitable masterbatch is, for example, present as a solution of the silylated acid amide in the starting isocyanate or in the already carbodiimidized isocyanate.
The present invention also relates to the organic isocyanates containing carbodiimide and/or uretonimine groups which are obtainable by the abovementioned process. These organic isocyanates containing carbodiimide and/or uretonimine groups are liquid at room temperature, and, depending on the CD/UI content and/or on the isocyanate employed, may be liquid down to low temperatures (e.g. 0° C.).
The present invention also provides a process for the preparation of isocyanate blends. These blends comprise the organic isocyanates containing carbodiimide and/or uretonimine groups according to the invention, and at least one other isocyanate component which is different than the isocyanates of the invention which contain carbodiimide and/or uretonimine groups. This invention also provides a process for the preparation of prepolymers which contain isocyanate groups and exhibit an improved color number from the isocyanates containing CD and/or UI groups of this invention.
Finally, the invention also provides a process for the preparation of polyurethane plastics, and preferably polyurethane foams, comprising reacting the organic isocyanates containing carbodiimide and/or uretonimine groups of the invention with at least one isocyanate-reactive component.
DETAILED DESCRIPTION OF THE INVENTION
As described and used herein, the Hazen color number can be measured in accordance with DIN/EN/ISO 6271-2 (draft of September 2002) in substance against water as the reference, at a layer thickness of 5 cm. For the measuring instrument, a Dr. Lange LICO 300 photometer e.g. can be employed.
Organic isocyanates having a higher color number can, of course, also be used as starting substances. When these higher color number isocyanates are used, however, the advantages with respect of the favorable color values are not utilized to the full extent.
Suitable organic isocyanates to be used as starting materials for the present invention include any desired organic isocyanates which have a Hazen color number of≦100 APHA, preferably ≦50 APHA. It is preferred that the process according to the invention provides for the carbodiimidization of organic diisocyanates which can in turn be employed in polyurethane chemistry.
Organic isocyanates having a higher color number can, of course, also be used as starting substances. In this case, however, the advantages with respect to the favorable color values cannot be utilized to the full extent.
Suitable isocyanates to be used in accordance with the present invention include, for example, aromatic, araliphatic, aliphatic and/or cycloaliphatic diisocyanates and/or polyisocyanates.
Representatives of the aliphatic and/or cycloaliphatic diisocyanates which may be mentioned by way of example are isophorone-diisocyanate, hexamethylene-diisocyanate and dicyclohexylmethane-diisocyanate. In each case, the pure isomers and/or any desired isomer mixtures may be used herein.
Representatives of the araliphatic diisocyanates which may be mentioned by way of example are the various isomers of xylidene-diisocyanates.
Aromatic di- and polyisocyanates, such as toluene-diisocyanate, and di- and polyisocyanates of the diphenylmethane series, are suitable for the starting isocyanate component of the present invention.
In particular, the following isocyanates are suitable starting materials:
aromatic diisocyanates, such as 2,4- and/or 2,6-diisocyanatotoluene (TDI), 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane (MDI) and any desired mixtures of such aromatic diisocyanates;
and
di- and polyisocyanate mixtures of the diphenylmethane series having a content of monomeric diisocyanatodiphenylmethane isomers of from 80 to 100 wt. % and a content of polyisocyanates of the diphenylmethane series which are more than difunctional of from 0 to 20 wt. %, with the diisocyanatodiphenylmethane isomers being composed of 0 to 100% by weight of 4,4′-diisocyanatodiphenylmethane, 100 to 0% by weight of 2,4′-diisocyanatodiphenylmethane, and 0 to 8% by weight of 2,2′-diisocyanatodiphenylmethane, with the sum of the percentages of the three isomers totalling 100% by weight of the monomer.
Organic isocyanates which are preferred as starting materials are, in particular, aromatic diisocyanates, such as 2,4- and/or 2,6-diisocyanatotoluene (TDI), 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane (MDI) and any desired mixtures of such aromatic diisocyanates. More preferred starting materials are 2,2′-, 2,4′-and/or 4,4′-diisocyanatodiphenylmethane (MDI) and any desired mixtures of such aromatic diisocyanates, with the sum of 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane in the starting material (organic isocyanate) being at least 85% by weight of the total weight, and the diisocyanatodiphenylmethane isomers being composed of from 0 to 100% by weight of 4,4′-diisocyanatodiphenylmethane, from 100 to 0% by weight of 2,4′-diisocyanatodiphenylmethane and of from 0 to 8% by weight of 2,2′-diisocyanatodiphenylmethane, with the sum of the percentages stated totalling 100% by weight. Most preferred starting materials are 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane (MDI), and any desired mixtures of aromatic diisocyanates, with the sum of 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane in the starting material (i.e. the starting organic isocyanate) being at least 90% by weight, and the diisocyanatodiphenylmethane isomers being composed of 0 to 100% by weight of 4,4′-diisocyanatodiphenylmethane, 100 to 0% by weight of 2,4′-diisocyanatodiphenylmethane and 0 to 8% by weight of 2,2′-diisocyanatodiphenylmethane, with the sum of the percentages of the three isomers totalling 100% by weight. Most particularly preferred starting materials are 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane (MDI) and any desired mixtures of aromatic diisocyanates, with the sum of 2,2′-, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane present in the starting material (i.e. the starting organic isocyanate) being at least 99% by weight and the diisocyanatodiphenylmethane isomers being composed of 0 to 100% by weight of 4,4′-diisocyanatodiphenylmethane, 100 to 0% by weight of 2,4′-diisocyanatodiphenylmethane, and 0 to 8% by weight of 2,2′-diisocyanatodiphenylmethane, with the sum of the percentages stated for the three isomers totalling 100% by weight.
The process according to the invention is carried out in the presence of catalysts of the phospholine type. The catalysts of the phospholine type are known and described in, for example, EP-A-515 933 and U.S. Pat. No. 6,120,699, the disclosures of which are hereby incorporated by reference. Typical examples of these catalysts are, for example, the mixtures, known from the prior art, of the phospholine oxides which correspond to the formulas:
The amount of catalyst employed depends on the quality and/or the reactivity of the starting isocyanates. Thus, the specific amount of catalyst needed can most easily and readily be determined in a preliminary experiment.
By using silylated acid amides, the reactivity of the starting isocyanate is increased. This can occur, for example, because these silylated acid amides counteract the reactivity-reducing action of secondary components in the starting isocyanate which potentially split off HCl (i.e. hydrochloric acid). Other action mechanisms are, however, also possible.
Suitable silylated acid amides to be used in accordance with the present invention include, for example, silylated carboxylic acid amides or silylated carbamates, such as e.g. N-trimethylsilylacetamide, N,O-bis(trimethylsilyl)acetamide, or trimethylsilyl N-trimethylsilylcarbamate or mixtures thereof. The compounds specifically mentioned are regarded only as examples. The suitable silylated acid amides are not limited to the specific compounds mentioned herein.
The silylated acid amide or the mixture of several different silylated acid amides can be added immediately before, at the same time as, or also, only after the addition of the catalyst to the starting isocyanate. It is preferred that the silylated acid amide is added only after the addition of the catalyst, i.e. during the carbodiimidization reaction. The best point in time for the addition of the silylated acid amide can be determined in a simple preliminary experiment, and is preferably before reaching 50%, more preferably before reaching 30% and most preferably before reaching 20% of the total desired conversion of isocyanate.
The optimum amount of the silylated acid amide which is employed can likewise be determined in a simple preliminary experiment. It is preferred to use ≦1,000 ppm, more preferred to use ≦250 ppm and most preferred to use ≦100 ppm, based on 100% by weight of the starting isocyanate employed.
Thus, the silylated acid amide can be added directly to the starting isocyanate, or to the reaction mixture during the carbodiimidization reaction. In this context, the silylated acid amide is preferably added in substance, i.e. without dilution, or as a masterbatch. A masterbatch, for example, is a solution of the silylated acid amide in the starting isocyanate or in already carbodiimidized isocyanate.
The addition of the silylated acid amide results in a higher reactivity with respect to the carbodiimidization reaction. As a result of this higher reactivity, one or both of the required reaction time and the required amount of catalyst can be reduced.
The carbodiimidization reaction is conventionally carried out in the temperature range between 50 to 150° C., preferably from 60 to 100° C. However, significantly higher reaction temperatures are also possible (i.e. up to approx. 280° C.). The optimum reaction temperature for the carbodiimidization reaction depends on the nature of the starting isocyanates and/or of the catalyst employed, and can be determined in a simple preliminary experiment.
The carbodiimidization reaction is in general, interrupted when a degree of carbodiimidization of from 3 to 50%, and preferably from 5 to 30%, is reached. The phrase “the degree of carbodiimidization” refers to the percentage of carbodiimidized isocyanate groups, with respect to the total amount of isocyanate groups present in the starting isocyanate.
The degree of carbodiimidization can be determined while the process according to the invention is being carried out, by determination of the % NCO by, for example, means of titration, which is known per se to the person skilled in the art, or by means of suitable online methods. A suitable online method is, for example, near infra-red or middle infra-red analysis.
The degree of carbodiimidization can likewise be ascertained while the process according to the invention is being carried out, for example, from the amount (i.e. quantity) of carbon dioxide escaping in the reactor mixture. This amount of carbon dioxide, which can be determined volumetrically, thus provides information about the degree of carbodiimidization reached at any point in time.
Furthermore, in principle, other suitable offline or online methods of process monitoring which are known to the person skilled in the art can also be employed.
To end the carbodiimidization reaction, it is preferable to add at least the equimolar amount, more preferably a 1- to 20-fold molar excess, and most preferably a 1- to 10-fold molar excess, based on the weight of the catalyst, of a terminator or an alkylating agent. A mixture of terminators may also be employed. A preferred catalyst terminator is trimethylsilyl trifluoromethanesulfonate (TMST). In this context, an alkylating agent or trimethylsilyl trifluoromethanesulfonate (TMST) is preferably employed as the sole terminator.
Preferred alkylating agents are esters of trifluoromethanesulfonic acid, esters of inorganic acids (preferably strong inorganic acids) or trialkyloxonium compounds.
The reaction product of the carbodiimidization reaction can contain color stabilizers such as those which are conventionally added to isocyanates. In this context, the point in time of the addition of the stabilizers is not critical. The color stabilizers can be added either to the isocyanate which is used as the starting material, before the carbodiimidization, or to the reaction product when the carbodiimization reaction has ended. Likewise, it is possible to add color stabilizers to both the starting material and to the reaction product. Such stabilizers are generally known to the person skilled in the art and include e.g. substances from the group consisting of sterically hindered phenols, phosphorous acid esters or sterically hindered amines. The color stabilizers can in each case be employed by themselves or in a mixture with other representatives of the same or different substance groups. The amounts of color stabilizers employed varies in the order of magnitude known to the person skilled in the art, conventionally in the range of from 100 ppm to 10,000 ppm for the individual substance or the mixture, based on the total weight of the isocyanate used as the starting material or of the reaction product of the carbodiimidization.
Prepolymers containing isocyanate groups are obtained by, for example, reaction of the organic isocyanates containing carbodiimide and/or uretonimine groups which are prepared by the process of the present invention with one or more conventional polyols which are known to be suitable in polyurethane chemistry. Suitable polyols include both simple polybasic alcohols having a molecular weight in the range of from 62 to 599 g/mol, preferably 62 to 300 g/mol, such as e.g. ethylene glycol, trimethylolpropane, propane-1,2-diol, butane-1,2-diol or butane-2,3-diol, hexanediol, octanediol, dodecanediol and/or octadecanediol, and in particular, higher molecular weight polyether polyols and/or polyester polyols of the type known per se from polyurethane chemistry which have molecular weights of from 600 to 8,000 g/mol, preferably 800 to 4,000 g/mol. Such higher molecular weight compounds typically contain at least two, and as a rule from 2 to 8, and preferably from 2 to 4 primary and/or secondary hydroxyl groups. Examples of such polyols are described in, for example, U.S. Pat. No. 4,218,543, at column 7, line 29 to column 9, line 32, the disclosure of which is hereby incorporated by reference.
The advantages of the process according to the invention are apparent: The reactivity of the reaction mixture is increased and/or standardized by the presence of a silylated acid amide during the carbodiimidization. As a result, the required reaction time can be lowered or kept low and/or the required amount of catalyst can be reduced. Both the isocyanates containing carbodiimide and/or uretonimine groups and the prepolymers prepared therefrom furthermore have a good storage stability and a light color.
These organic isocyanates containing carbodiimide and/or uretonimine groups and the prepolymers prepared therefrom by reaction of the isocyanates of the invention with polyols are valuable starting materials for the preparation of polyurethane plastics by the reaction of the isocyanates of the invention or prepolymers thereof with one or more polyols (e.g. polyether polyols and/or polyester polyols) by the isocyanate polyaddition process.
The following examples further illustrate details for the process of this invention. The invention, which is set forth in the foregoing disclosure, is not to be limited either in spirit or scope by these examples. Those skilled in the art will readily understand that known variations of the conditions of the following procedures can be used. Unless otherwise noted, all temperatures are degrees Celsius and all percentages are percentages by weight.
EXAMPLES
The following starting substances were used in the working examples:
Isocyanate A: 4,4′-diphenylmethane diisocyanate having an NCO group content of 33.6% by weight (Desmodur 44M®, Bayer AG) Catalyst A: a technical-grade mixture of 1-methyl-1-oxo-1-phosphacyclopent-2-ene and 1-methyl-1-oxo-1-phosphacyclopent-3-ene, 1 wt. % strength in toluene Terminator A: trifluoromethanesulfonic acid ethyl ester (TFMSEE) Terminator B: trimethylsilyl trifluoromethanesulfonate (TMST) Silylated Acid Amide A: N,O-bis(trimethylsilyl)acetamide Silylated Acid Amide B: trimethylsilyl N-trimethylsilylcarbamate
The following general instructions were used for the preparation of the organic isocyanate containing carbodiimide and/or uretonimine groups:
10 kg of Isocyanate A having a Hazen color number of <15 APHA, which contained 750 ppm 3,5-di-tert-butyl-4-hydroxytoluene, were heated to approx. 90° C. under N 2 /while stirring. The amount of catalyst solution as shown in the table in order to achieve the desired amount of catalyst was then added. The corresponding amount of the silylated acid amide was added to the reaction mixture (see the table for details including which silylated acid amide was added, the specific point in time of the addition, and the amount of silylated acid amide added in each example). The reaction mixture was heated at approx. 95° C. under N 2 while stirring until the desired NCO content was reached. Thereafter, the carbodiimidization reaction was terminated by the addition of the specific terminator (i.e. trifluoromethanesulfonic acid ethyl ester (TFMSEE) or trimethylsilyl trifluoromethanesulfonate (TMST); see table for specific details) and the mixture was subsequently stirred for 1 hour.
The results are summarized in the following table.
The Hazen color number was measured in accordance with DIN/EN/ISO 6271-2 (draft of September 2002), in substance against water as the reference at a layer thickness of 5 cm. A Dr. Lange LICO 300 photometer was employed as the measuring instrument.
Educt
Reaction conditions
Time of
addition of
Conc.
Silylated
of
acid
silylated
amide
acid
after
Product
Viscosity
Hydrolysable
Catalyst
Terminator
Silylated
amide
addition of
Reaction
NCO
at
chlorine
concentration
concentration
Acid
agent
catalyst
time
value
HAZEN
25° C.
[ppm]
[ppm]
Terminator
[ppm]
Amide
[ppm]
[min]
[min]
[%]
[APHA]
[mPas]
Comparison
10
2.5
TMST
50
—
—
—
310
29.4
—
—
Example 1
Comparison
20
2.5
TMST
50
—
—
—
360
31.6
—
—
Example 2
Example 1
19
2.5
TMST
50
A
100
0
195
29.5
—
—
Example 2
22
2.5
TMST
50
B
100
120
220
29.3
—
—
Example 3
11
1.0
TFMSEE
20
A
100
0
270
29.7
169
29
Comparison Examples 1 and 2 illustrate the influence of the increased content of hydrolysabe chlorine on the reactivity or the reaction time.
In Examples 1 and 2 according to the invention, an improved reactivity was achieved compared with Comparison Example 2. This leads to shorter reaction times in Examples 1 and 2 which are representative of the present invention, while using the same concentration of catalyst.
In spite of a lower concentration of catalyst employed in Example 3, which is also representative of the invention, this resulted in an even further shortened reaction time compared with Comparison Example 1. This demonstrates the increase in the reactivity of the 4,4′-diphenylmethane-diisocyanate employed as the starting isocyanate effected by the addition of the silylated acid amide.
The resultant isocyanate products achieved a good color level (HAZEN).
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
|
The invention relates to a process for the preparation of liquid, storage-stable isocyanate mixtures of low color number and which contain carbodiimide (CD) and/or uretonimine (UI) groups, the isocyanate mixtures obtainable by this process, and to a process for the preparation of blends of these isocyanates with additional isocyanate components and to a process for the preparation of prepolymers containing isocyanate groups and of polyurethane plastics, preferably polyurethane foams.
| 2
|
FIELD OF THE INVENTION
[0001] The invention relates to the manufacture of hot-rolled and cold-rolled austenitic iron/carbon/manganese steel sheets exhibiting very high mechanical properties, and especially a particularly advantageous combination of mechanical strength and fracture elongation, excellent formability and a high fracture resistance in the presence of defects or stress concentrations.
PRIOR ART
[0002] It is known that certain applications, especially in the automotive field, require metal structures to be lightened and have greater strength in the event of an impact, and also good drawability. This requires the use of structural materials that combine high tensile strength with great deformability. In the case of hot-rolled sheet, that is to say with a thickness ranging from 0.6 to 10 mm, these properties are advantageously used to manufacture floor connection parts or wheels, reinforcing parts such as door anti-intrusion bars, or parts intended for heavy vehicles (trucks, buses). In the case of cold-rolled sheet (ranging from 0.2 mm to 4 mm), the applications are for the manufacture of beams that absorb deformation energy or engine cradles, or else skin parts. However, tensile strength and deformability are competing properties, so much so that it is generally not possible to obtain very high values for one of the properties without drastically reducing the other. However, progress has been made recently in trying to meet these requirements better, in particular thanks to the development of what are called TRIP (Transformation Induced Plasticity) steels. However, this type of steel does not make it possible to obtain an elongation of greater than 25% for a strength level of 900 MPa. Although these properties may be satisfactory for a number of applications, they nevertheless remain insufficient if further lightening is desired, and under severe stressing conditions such as those encountered in automobile collisions.
[0003] Also known are austenitic Fe—C(0 to 1.5%)—Mn(15 to 35%)—Cr(0 to 20%)—Al(0.1 to 10%)—Si(0 to 4%) steels that combine good strength with excellent ductility. The mode of deformation of these steels depends only on the stacking fault energy or SFE. Among these modes, mechanical twinning makes it possible to obtain high work-hardenability. Twins, by acting as an obstacle to the propagation of dislocations, thus help to increase the flow stress. The twinning deformation mechanism is favoured by increasing the stacking fault energy up to a limit (about 30 mJ/m 2 ), above which perfect dislocation glide becomes the dominant deformation mechanism. The SFE increases with the carbon, manganese and aluminum contents. Patent EP 0 573 641 discloses a hot-rolled or cold-rolled austenitic steel containing less than 1.5% C, 15-35% Mn and 0.1-6% aluminum, the strength of which is greater than 490 MPa and the elongation greater than 40% at room temperature.
[0004] However, rolling this type of composition requires particular precautions to be taken so as to prevent the formation of defects.
[0005] There is also an unsatisfied need for having steel sheet exhibiting even more favorable (strength/elongation at fracture) combinations, while limiting the content of expensive alloying elements.
[0006] Furthermore, experience shows that, despite favorable elongation values in uniaxial tension, cold forming (drawing, relatively complex bending, etc.) may pose difficulties in certain cases. In addition, since the parts produced from such sheet very often include regions corresponding to stress concentrations, there is a major need to have steel of high toughness, that is to say in which the fracture or tear resistance in the presence of defects is high, in particular under dynamic stressing. This property is all the more important to take into consideration when the applications of these grades, for example in automobiles, relate specifically to very highly stressed regions and/or to safety components.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the invention to have a hot-rolled or cold-rolled steel sheet or product that is inexpensive to manufacture, has a strength of greater than 900 MPa after hot rolling, greater than 950 MPa after cold rolling, a (strength/elongation at fracture) combination such that the product P=strength (expressed in MPa)×elongation at fracture (in %) is greater than 45000, can be easily hot-rolled, is particularly suitable for undergoing cold forming, and has very good toughness under static or dynamic stressing conditions.
[0008] For this purpose, the subject of the invention is a hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 900 MPa, the product (strength (in MPa)×elongation at fracture (in %)) of which is greater than 45000 and the chemical composition of which comprises, the contents being expressed by weight: 0.5%≦C≦0.7%; 17%≦Mn≦24%; Si≦3%; Al≦0.050%; S≦0.030%; P≦0.080%; N≦0.1%, and, optionally, one or more elements such that: Cr≦1%; Mo≦0.40%; Ni≦1%; Cu≦5%; Ti−0.50%; Nb≦0.50%; V≦0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting, the recrystallized fraction of the steel being greater than 75%, the surface fraction of precipitated carbides of the steel being less than 1.5% and the mean grain size of the steel being less than 18 microns.
[0009] The subject of the invention is also a hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 900 MPa, the product (strength (in MPa)×elongation at fracture (in %)) of which is greater than 60000 and the chemical composition of which comprises, the contents being expressed by weight: 0.5%≦C≦0.7%; 17%≦Mn≦24%; Si≦3%; Al≦0.050%; S≦0.030%; P≦0.080%; N≦0.1%, and, optionally, one or more elements such that: Cr≦1%; Mo≦0.40%; Ni≦1%; Cu≦5%; Ti≦0.50%; Nb≦0.50%; V≦0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting, the recrystallized fraction of the steel being equal to 100%, the surface fraction of precipitated carbides of the steel being equal to 0% and the mean grain size of the steel being less than 10 microns.
[0010] The subject of the invention is also a process for manufacturing a hot-rolled sheet made of iron/carbon/manganese steel, in which: a steel is smelted whose chemical composition comprises, the contents being expressed by weight: 0.5%≦C≦0.7%; 17%≦Mn≦24%; Si≦3%; Al≦0.050%; S≦0.030%; P≦0.080%; N≦0.1%, and, optionally, one or more elements such that: Cr≦1%; Mo≦0.40%; Ni≦1%; Cu≦5%; Ti≦0.50%; Nb≦0.50%; V≦0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting; a semifinished product is cast from this steel; the semifinished product of said steel composition is heated to a temperature of between 1100 and 1300° C.; the semifinished product is rolled with an end-of-rolling temperature of 890° C. or higher; a delay is observed between said end of rolling and a subsequent rapid cooling operation, in such a way that the point defined by said delay and said end-of-rolling temperature lies within an area defined by the ABCD′E′F′A plot, and preferably the ABCDEFA plot, of FIG. 1 ; and the sheet is coiled at a temperature below 580° C.
[0011] Preferably, the semifinished product is cast in the form of thin strip, being cast between steel rolls.
[0012] According to another preferred feature, after the coiling, the hot-rolled sheet is subjected to a cold deformation operation with an equivalent deformation ratio of 30% or less.
[0013] The subject of the invention is also a cold-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 950 MPa, the product strength (in MPa)×elongation at fracture (in %) of which is greater than 45000 and the chemical composition of which comprises, the contents being expressed by weight: 0.5%≦C≦0.7%; 17%≦Mn≦24%; Si≦3%; Al≦0.050%; S≦0.030%; P≦0.080%; N≦0.1%, and, optionally, one or more elements such that: Cr≦1%; Mo≦0.40%; Ni≦1%; Cu≦5%; Ti≦0.50%; Nb≦0.50%; V≦0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting, the recrystallized fraction of the structure of the steel being greater than 75%, the surface fraction of precipitated carbides of the steel being less than 1.5% and the mean grain size of the steel being less than 6 microns.
[0014] The subject of the invention is also a process for manufacturing a cold-rolled austenitic iron/carbon/manganese steel sheet, characterized in that a hot-rolled sheet obtained by one of the processes described above is supplied; at least one cold-rolling step followed by an annealing operation is carried out, each step consisting in cold-rolling the sheet and annealing it at a temperature of between 600 and 900° C. for a time of between 10 and 500 seconds, followed by a cooling operation, the cooling rate being greater than 0.5° C./s, the austenitic grain size, before the final cold-rolling step followed by an annealing operation, being less than 18 microns.
[0015] Preferably, after the final annealing, a cold-deformation operation is carried out on the cold-rolled sheet with an equivalent deformation ratio of 30% or less.
[0016] The subject of the invention is also the use of a hot-rolled or cold-rolled sheet described above or the use of a sheet manufactured by means of a process described above for the manufacture of reinforcing elements that are statically or dynamically stressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Further features and advantages of the invention will become apparent over the course of the description below, which is given by way of example and with reference to the following appended figures:
[0018] FIG. 1 shows the influence of the end of hot rolling temperature and of the delay between the end of hot rolling and the start of a subsequent rapid cooling operation on the recrystallized fraction after coiling;
[0019] FIG. 2 shows the influence of the recrystallized fraction on the critical strain at fracture in bending;
[0020] FIG. 3 shows the influence of the coiling temperature on the surface fraction of precipitated carbides;
[0021] FIG. 4 is a micrograph illustrating an example of intergranular carbide precipitation;
[0022] FIG. 5 illustrates the influence of the surface fraction of precipitated carbides, of constant grain size, on the product P (strength×elongation at fracture);
[0023] FIG. 6 shows the influence of the mean austenitic grain size on the strength of Fe—C—Mn steel sheet, in particular hot-rolled sheet;
[0024] FIG. 7 illustrates the influence of the equivalent deformation ratio on the strength of a cold-rolled Fe—C—Mn steel sheet;
[0025] FIG. 8 shows the influence of the mean austenitic grain size on the strength of sheet, in particular cold-rolled sheet;
[0026] FIG. 9 illustrates the influence of the mean austenitic grain size on the specific fracture energy of cold-rolled sheet;
[0027] FIG. 10 shows the influence of the mean austenitic grain size on the Charpy fracture energy of cold-rolled sheet;
[0028] FIG. 11 illustrates the influence of the mean austenitic grain size on the critical cracking strain in bending; and
[0029] FIG. 12 shows the maximum drawing depth before fracture as a function of the mean austenitic grain size.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] After many trials, the inventors have shown that the various requirements reported above can be satisfied by observing the following conditions:
[0031] As regards the chemical composition of the steel, carbon plays a very important role in the formation of the microstructure: it increases the SFE and favors stability of the austenitic phase. When combined with a manganese content ranging from 17 to 24% by weight, this stability is achieved for a carbon content of 0.5% or higher. However, for a carbon content above 0.7%, it becomes difficult to prevent the precipitation of carbides that occurs during certain thermal cycles in industrial manufacture, in particular when the steel is being cooled at coiling, and that degrades both ductility and toughness.
[0032] Manganese is also an essential element for increasing the strength, increasing the stacking fault energy and stabilizing the austenitic phase. If its content is less than 17%, there is a risk of martensitic phases forming, which phases very appreciably reduce the deformability. Moreover, when the manganese content is greater than 24%, the ductility at room temperature is reduced. In addition, for cost reasons, it is undesirable for the manganese content to be high.
[0033] Aluminum is a particularly effective element for the deoxidation of steel. Like carbon, it increases the stacking fault energy. However, aluminum is a drawback if it is present in excess in steels having a high manganese content. This is because manganese increases the solubility of nitrogen in liquid iron, and if an excessively large amount of aluminum is present in the steel the nitrogen, which combines with aluminum, precipitates in the form of aluminum nitrides that impede the migration of grain boundaries during hot transformation and very appreciably increases the risk of cracks appearing. An Al content of 0.050% or less prevents the precipitation of AlN. Correspondingly, the nitrogen content must not exceed 0.1% so as to prevent this precipitation and the formation of volume defects (blowholes) during solidification.
[0034] Silicon is also an effective element for deoxidizing steel and for solid-phase hardening. However, above a content of 3%, it tends to form undesirable oxides during certain assembly processes and must therefore be kept below this limit.
[0035] Sulfur and phosphorus are impurities that embrittle the grain boundaries. Their respective contents must not exceed 0.030 and 0.080% so as to maintain sufficient hot ductility.
[0036] Chromium and nickel may be used as optional elements for increasing the strength of the steel by solution hardening. However, since chromium reduces the stacking fault energy, its content must not exceed 1%. Nickel contributes to the achievement of a high elongation at fracture, and in particular increases the toughness. However, it is also desirable, for cost reasons, to limit the nickel content to a maximum content of 1% or less. For similar reasons, molybdenum may be added in an amount of 0.40% or less.
[0037] Likewise, optionally, an addition of copper with a content not exceeding 5% is one means of hardening the steel by precipitation of copper metal. However, above this content, copper is responsible for the appearance of surface defects in hot-rolled sheet.
[0038] Titanium, niobium and vanadium are also elements that may optionally be used to achieve hardening by precipitation of carbonitrides. However, when the Nb or V or Ti content is greater than 0.50%, excessive carbonitride precipitation may cause a reduction in toughness, which has to be avoided.
[0039] The method of implementing the manufacturing process according to the invention is as follows. A steel having the composition mentioned above is smelted. After the smelting, the steel may be cast in ingot form, or cast continuously in slab form with a thickness of around 200 mm. The steel may also be cast in thin slab form, with a thickness of a few tens of millimeters. Of course, although the present invention illustrates the application of the invention to flat products, it may be applied in the same way to the manufacture of long products made of Fe—C—Mn steel.
[0040] These cast semifinished products are firstly heated to a temperature between 1100 and 1300° C. This has the purpose of making every point reach the temperature ranges favorable for the large deformations that the steel will undergo during rolling. However, the reheat temperature must not be above 1300° C. for fear of being too close to the solidus temperature, which could be reached in any manganese and/or carbon segregated zones, and of causing the local onset of a liquid state that would be deleterious to hot forming. Of course, in the case of the direct casting of thin slabs, the hot-rolling step for these semifinished products, may be carried out directly after casting, without passing via the intermediate reheat step.
[0041] The semifinished product is hot-rolled, for example down to a hot-rolled strip thickness of 2 to 3 millimeters in thickness. The low aluminum content of the steel according to the invention prevents excessive precipitation of AlN, which would impair hot deformability during rolling. To avoid any cracking problem through lack of ductility, the end-of-rolling temperature must be 890° C. or higher.
[0042] Moreover, it is known that industrial lines include rapid cooling devices, for example those operating by water spray, located between the final hot-rolling step and the coiling. These devices increase the rate of natural cooling of the products so that the length of the industrial lines is not excessively long.
[0043] In combination with a given end-of-rolling temperature, the inventors have shown, as indicated in FIG. 1 , that a minimum delay must be respected between the end of rolling and the start of rapid cooling, so as to achieve satisfactory recrystallization of the rolled product after coiling. During this delay, the product undergoes natural cooling. Thus, a minimum delay of 12 s at 890° C., or 4 s at 905° C., makes it possible to achieve complete recrystallization. More generally, parameters (temperature and minimum delay) lying within the region defined by ABCDEFA in FIG. 1 result in complete recrystallization under satisfactory productivity conditions. Recrystallization corresponding to a minimum fraction of 75% is obtained when these conditions (temperature and minimum delay) lie within the region defined by ABCD′E′F′A. FIG. 2 shows the influence of the recrystallized fraction on the critical strain for the appearance of cracks in bending. A high bendability, and more generally a high deformability, requires high critical strain values, of greater than 50%. FIG. 2 shows that this is obtained when the recrystallized fraction after rolling is greater than 75%.
[0044] After rolling, the strip has to be coiled at a temperature such that no significant precipitation of carbides (essentially cementite (Fe,Mn) 3 C)) occurs, something which, as will be seen later, would result in a reduction in certain mechanical properties. FIG. 3 illustrates the influence of the coiling temperature on the surface fraction of precipitated carbides. Carbide precipitation essentially takes place at the austenitic grain boundaries, as the micrograph of FIG. 4 shows. FIG. 5 shows the influence of this precipitation on the product P (the tensile strength multiplied by the elongation at fracture) after hot rolling, for constant grain size. High values of this parameter therefore express a combination of high strength and high ductility. To obtain a value of P of greater than 45000 MPa×%, it is necessary for the surface fraction of precipitated carbides to be less than 1.5%. Since this deleterious aspect of carbide precipitation applies both to hot-rolled sheet and to cold-rolled and annealed sheet, it is necessary to comply with this these maximum permissible level of precipitation in both these situations.
[0045] From the results shown in FIG. 3 , it may be seen that this condition is satisfied on hot-rolled product when the coiling temperature is below 580° C.
[0046] Moreover, FIG. 6 illustrates the influence of the mean austenitic grain size on strength. In the case of hot-rolled products, this figure thus shows that the grain size must not exceed 18 microns for fear of the strength being less than 900 MPa.
[0047] The inventors have also demonstrated that even higher mechanical properties are obtained under the following conditions on hot-rolled product: the simultaneous combination of a grain size of less than 10 microns, a recrystallized fraction of 100% and a surface fraction of precipitated carbides of 0% results in a value of the product P (R m ×elongation at fracture) of greater than 60000.
[0048] The hot-rolled strip obtained by the process described may be used as such, or may undergo subsequent cold rolling followed by annealing. This additional step makes it possible to achieve a finer grain size than that obtained on hot-rolled strip, and therefore higher strength properties are obtained. Of course, it has to be carried out if it is desired to obtain products of smaller thickness, typically ranging from 0.2 mm to 4 mm.
[0049] A hot-rolled product obtained by the process described above is cold-rolled after a possible prior pickling operation has been performed in the usual manner.
[0050] After this rolling step, the grains are highly work-hardened and it is necessary to carry out a recrystallization annealing operation. This treatment has the effect of restoring the ductility and simultaneously reducing the strength. The annealing heat treatment must therefore be adjusted so as to obtain the (strength/elongation at fracture) combination desired for the application. Preferably, this annealing is carried out continuously.
[0051] This annealing is performed at a temperature of 600 to 900° C. for a time of 10 to 500 seconds, and the cooling rate at the end of the soak must be sufficiently rapid, greater than 0.5° C./s, to prevent the precipitation of carbides. Starting with an initial mean grain size of 18 microns or less on hot-rolled product, the above parameters make it possible to achieve a mean grain size ranging from 0.5 to 15 microns on cold-rolled sheet.
[0052] According to one particular method of implementation, the thickness may be reduced by cold rolling, not by means of a single rolling step but by two or more steps, each of the rolling steps being followed by an annealing operation. The grain size prior to the last rolling-and-annealing step must not exceed 18 microns, for fear of reducing the strength and the deformability of the end-product.
[0053] For the same reasons as those mentioned in the case of hot-rolled sheet, cold-rolled sheet must have a sufficient recrystallized fraction, of greater than 75%, in order to obtain satisfactory deformability during cold forming.
[0054] As in the case of hot-rolled sheet, the surface fraction of precipitated carbides must be less than 1.5% so that the product P (R m ×elongation at fracture) is greater than 45000 MPa×%.
[0055] Steel sheets obtained, after hot or cold rolling, by the process according to the invention are characterized by an excellent ductility. Owing to the large reserve of plasticity, even higher strength values may be sought, at the expense of a slight lowering in ductility. Starting from a hot-rolled sheet, after coiling, or a cold-rolled and annealed sheet according to the process described above, an additional cold deformation operation is applied to it after the final annealing, for example by skin-pass rolling, reverse-bending tension leveling, simple drawing or any other suitable process. FIG. 7 shows the influence of the equivalent deformation ratio on the strength: the influence of the deformation ratio is relatively linear over a wide range—on average, 1% deformation increases the strength by 10 MPa. However, when the additional deformation exceeds 30%, the initial ductility of the product is excessively reduced, and this threshold must not be exceeded.
[0056] As FIG. 8 shows, a mean grain size on cold-rolled sheet of less than 6 microns makes it possible to achieve a strength of greater than 950 MPa.
[0057] By way of example, the following results will show advantageous characteristics provided by the invention, in particular as regards deformability with or without the presence of a defect, in static or dynamic stressing mode.
EXAMPLE 1
[0058] A steel of the following composition (contents expressed in percentages by weight): C: 0.6%; Mn: 22%; Si: 0.2% was smelted. A semifinished product was heated at 11850C and hot-rolled at a temperature of 9650C so as to achieve a thickness of 3.6 mm. A hold time of 3.5 s was observed before cooling. The coiling was carried out at a temperature below 450° C. The manufacturing conditions, identified by “I ” in Table 1 below correspond to the invention. The mean grain size thus obtained was 9.5 microns, the structure was 100% recrystallized and the fraction of carbides was 0%. The static mechanical properties obtained on this hot-rolled sheet were particularly high, namely strength: 1012 MPa; elongation at fracture: 65.4%; product P: 66184.
[0059] Starting with this same composition, a thermomechanical scheme not corresponding to the conditions of the invention was performed, which resulted in a surface fraction of precipitated carbides of greater than 1.5% (condition identified as “R3”).
[0060] The steel according to the invention was also compared with a hot-rolled reference steel identified as “R4”, the strength level of which was very similar. This was a TRIP (Transformation Induced Plasticity) steel with a complex (ferrite, bainite, austenite, martensite) structure. This steel had the following composition (contents in % by weight): C: 0.20; Mn: 1.7; Si: 1.6; S: 0.003; P: 0.080; Al: 0.050; and Cu, Cr, Ni, Mo and N: 0.001.
[0061] Dynamic fracture tests were carried out on Charpy V specimens of small thickness (t=3 mm) at temperatures of +20° C. and −60° C. The results of these tests are given in Table 1.
TABLE 1 Results of Charpy V tests on hot-rolled sheet Charpy fracture Charpy energy at fracture +20° C. energy at Identifier (Joules) −60° C. (Joules) Invention I 44 36 Reference R3 33 29 R4 25 9
[0062] The steel according to the invention has substantially better toughness properties than the reference steels. This superiority is manifested at room temperature, and also under severe stressing conditions at very low temperature. It therefore completely solves the problem of how to obtain very good toughness under dynamic conditions.
EXAMPLE 2
[0063] Steels with the compositions indicated in Table 2 below were smelted (compositions expressed in percentages by weight). Apart from steels I1 and I2, the composition of reference steels is given for comparison, these being dual-phase steel (R1) and TRIP (Transformation Induced Plasticity) steel (R2), the strength level of which (1000 MPa) lies within a similar range.
[0064] Semifinished products of steels I1 and I2 were reheated at 1200° C., hot-rolled at a temperature of 920° C., in order to bring them to a thickness of 3 mm, and then, after a hold time of 10 seconds before cooling, coiled at a temperature of 450° C. The mean grain size obtained under these conditions was 10 microns. The structure was completely recrystallized, with no precipitated carbides.
TABLE 2 Composition of the steels Steel C Mn Si S P Al Cu Cr Ni Mo N I1 0.61 21.5 0.49 0.001 0.016 0.003 0.02 0.053 0.044 0.009 0.01 I2 0.68 22.8 0.17 0.001 0.004 0.005 0.005 0.005 0.005 0.01 0.003 R1 0.19 1.9 0.33 0.003 0.03 0.025 0.019 0.02 0.09 R2 0.20 1.7 1.6 0.003 0.080 0.050 0.001 0.001 0.001 0.001 0.001
[0065] Steel I1 was then cold-rolled, then annealed under conditions resulting in various austenitic grain sizes ranging from 3 to 100 microns. Table 3 gives the annealing and recrystallization conditions (conditions a) to d)) and Table 4 gives the mechanical properties in tension, namely strength, elongation at fracture and the product P (strength×elongation at fracture) obtained under these conditions.
[0066] Under manufacturing condition b), the grain size prior to cold rolling and annealing at 800° C. was 100 microns.
[0067] It should be mentioned that a cold-rolling reduction ratio of 66% combined with annealing at 650° C. for 1 second results only in a partial recrystallization of 45%. The grain size of the recrystallized fraction was highly scattered, ranging from 1 to 10 microns.
[0068] Steel I2 was also cold-rolled with a reduction ratio of 55%, annealed at 700° C. for 120 seconds and cooled in air, at a rate of greater than 0.5° C./s (condition e), Table 3). A 1.5 micron mean grain size and a 1% surface fraction of precipitated carbides were thus obtained. Starting from condition e), a subsequent heat treatment with a soak at 850° C. for 60 seconds followed by water cooling (condition f), Table 3), allows this fraction of precipitated carbides to be reduced without excessive grain coarsening.
TABLE 3 Cold-rolling and annealing conditions Cold-rolling Annealing Mean grain size: reduction temperature Annealing Steel Microstructure ratio (%) (° C.) time(s) I1 a)* 3 microns 60 700 120 b) 15 microns 16 800 240 c) 100 microns 50 1200 180 d) Recrystallization: 66 650 1 45% I2 e)* 1.5 microns with 55 700 120 s + slow carbides cooling f)* 4 microns 55 + 5 700 + 850 120 s + slow cooling + 60 s + water cooling *According to the invention.
[0069]
TABLE 4
Tensile mechanical properties obtained
Elongation
Mean grain size:
Strength
at fracture
P = R m × A
Steel
Condition
Microstructure
(MPa)
(%)
(MPa × %)
I1
a)*
3 microns
1130
55
62150
b)
15 microns
950
30
28500
c)
100 microns
850
40
34000
d)
Recrystallization:
1200
25
30000
45%
I2
e)*
1.5 microns with
1100
50
55000
1% carbides
f)*
4 microns
1070
50
53500
*According to the invention.
[0070] The steel manufacturing conditions a) correspond to those of the invention and result in high values of strength and of parameter P. Under condition b), the 100 micron grain size before cold rolling exceeds the 18 micron grain size mentioned above, and the final grain size (15 microns) is greater than the 6 micron grain size also mentioned above. Under condition c), the 100 micron grain size in cold-rolled sheet is also excessive. Consequently, conditions b) and c) result in unsatisfactory values of the parameter P and the strength.
[0071] Condition d) corresponds to a situation in which the recrystallization is insufficient (crystallized fraction: 45%, i.e. less than the 75% value mentioned above), which results in a low value of the parameter P.
[0072] In the case of steel I2, the manufacturing conditions e) are associated with a fine grain size of 1.5 microns and an amount of precipitated carbides of less than 1.5%. In the same way as in the case for steel f), the fine grain size results in high values of strength and the parameter P.
[0073] Furthermore, fracture strength tests were carried out on CT (Compact Tension) type specimens having dimensions of 36×55 mm 2 and comprising an initial notch of 8 mm in depth. The tests were carried out at room temperature and comprised a recording of the load and the displacement. The fracture energy of the various steels, determined by the area under the curve of the force-displacement plot, was divided by the area of the fracture surface so as to determine a specific fracture energy. FIG. 9 indicates that recrystallized steels of small grain size, containing no precipitated carbides, have the best fracture toughness characteristics. For a similar grain size, a 1% content of precipitated carbides reduces the toughness by about one third. A very low fracture toughness is also observed when the mean grain size is increased up to 100 microns, or when there is greatly insufficient recrystallization.
[0074] FIG. 9 also demonstrates the fact that sheets manufactured according to the invention offer better toughness characteristics than reference steels R1 and R2, since, for equivalent strength, the fracture toughness is two to three times greater than that of these steels.
[0075] Moreover, dynamic fracture tests were carried out on a Charpy V specimen of reduced thickness (t=1 to 1.3 mm) over a range from 20° C. to −100° C. No reduction in fracture energy was observed at low temperatures. The various cold-rolling and annealing conditions for steel I1, the variation in fracture energy with grain size is indicated in FIG. 10 . In a similar way to that which was noted in static fracture, too large a grain size or insufficient recrystallization reduces the fracture energy. For comparison, the fracture energy values at 20° C. and at −20° C. for the above steel R2 have also been plotted: it should be noted that the fine-grained steels of the invention make it possible to achieve higher toughness values under dynamic conditions than those of this reference steel. In addition, as mentioned above, the steels according to the invention are practically insensitive to temperature variations, unlike the reference steels which exhibit a ductile/brittle transition temperature. Thus, even in the event of very substantial impacts (very low service temperature, high deformation rate) the use of steels of the invention avoids the risk of sudden fracture.
[0076] Apart from the notched fracture strength capability, the steels of the invention exhibit great deformability for the manufacture of relatively complex parts. FIG. 11 indicates the bending capability of steel I1 under the various manufacturing conditions presented in Table 3, that is to say for a mean grain size varying from 3 to 100 microns. As was seen previously, apart from the advantage of achieving a strength of greater than 950 MPa, a mean grain size of less than 6 microns also makes it possible to obtain excellent deformability in bending. Here again, insufficient recrystallization leads to inferior results.
[0077] FIG. 12 also illustrates the benefit of cold-rolled and annealed steels according to the invention under complex deformation conditions such as those encountered in drawing tests using a cruciform tool that stresses the material in expansion and in necking. The tests were carried out on a blank having dimensions of 300×300 mm 2 , with a tool of 60 mm in height. FIG. 12 , which illustrates the maximum drawing depth before fracture, indicates that the steels according to the invention, of small grain size, have greatly superior properties to the reference steels R1 and R2.
[0078] Thus, for the same strength, the steels according to the invention are very much more deformable than conventional dual-phase or TRIP steels, and greater toughness. For the same deformation, their strength level is much higher. When they are used in the automotive industry, they contribute very effectively to reducing the weight of vehicles, while increasing safety in the event of an impact. The hot-rolled or cold-rolled steel sheets according to the invention are therefore advantageously used to manufacture reinforcing parts that require very high mechanical properties under static or dynamic loading conditions.
|
The invention relates to a hot rolled sheet which is made from austenitic iron/carbon/manganese steel and which has a resistance of greater than 900 MPa, whereby: resistance (MPa) x elongation at rupture (%) is greater than 45000. The chemical composition of the inventive sheet comprises the following concentrations expressed as weight: 0.5%=C=0.7%, 17%=Mn=24%, Si=3%, Al=0.05%, S=0.03%, P=0.08%, N=0.1% and, optionally, one or more elements such as Cr=1%, Mo=0.4%, Ni=1%, Ti=0.5%, Nb=0.5%, V=0.5%, Cu=5%, Cu=5%, the rest of the composition comprising iron and impurities resulting from production. According to the invention, the recrystallised fraction of the steel is greater than 75% and the surface fraction of precipitated carbides of the steel is less than 1.5%, the average grain size of the steel being less than 18 micrometers.
| 8
|
FIELD OF THE INVENTION
[0001] This invention relates to a pipeline padder. In particular the invention relates to a pipeline padder that is able to cover pipes with sand. However it should be appreciated that the pipeline padder may be used with other particulate materials such as gravel, blue metal or other aggregates.
BACKGROUND OF THE INVENTION
[0002] Pipelines are integral to most countries infrastructure. The technology surrounding the laying of pipes has increased dramatically over the years. This increase in technology has enabled pipes made of various materials to be laid very quickly. Accordingly it has been necessary to develop technology that enables pipes that have been laid to also be covered quickly and without damage. This has led to the development of pipeline padders.
[0003] Pipeline padders are used to deliver particulate material to cover pipes both quickly and accurately. Some pipeline padders have been developed that screen the materials that have been excavated to form a trench in which the pipeline has been laid. This type of pipeline padder scoops up the excavated materials, then screens the excavated material removing the larger material and then delivers the screened material remaining back into the trench to cover the pipeline safely. However, in many instances, the specification of the pipeline does not allow the material that has been excavated from the trench to be redelivered on top of the pipes. Therefore these types of pipeline padders are unable to be used when specific material, such as sand, is specified to cover pipes within the pipeline.
[0004] When material such as sand is required to be used to cover the pipes, the sand typically needs to be transported from a remote location to site. When the sand arrives at site, the sand is usually dumped in piles adjacent to the trench and then moved by excavators onto the pipes. This is a very time consuming process.
[0005] As an alternative, trucks have been converted into pipeline padders to deliver particulate material. Unfortunately these pipeline padders are unable to transport a large amount of particular material and the conveyor systems are often too light. Further, if the particulate material is located in a remote location, a large number of vehicles are required to keep pace with the laying of pipe. This is a large capital cost that may not be able to be recuperated in subsequent operations.
[0006] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.
OBJECT OF THE INVENTION
[0007] It is an object of the invention to overcome and/or alleviate one or more of the above disadvantages and/or provide the consumer with a useful or commercial choice.
SUMMARY OF THE INVENTION
[0008] In one form not necessarily the only or broadest form, the invention resides in a pipeline padder comprising:
[0009] a storage unit including a hopper for storing particulate material and a storage conveyor to remove particulate material from the hopper;
[0010] a loading unit including a loading conveyor to load particulate material into the hopper;
[0011] a discharge unit including a discharge conveyor for discharging particular material supplied by the storage conveyor; and
[0012] a locomotion unit to move the storage unit.
[0013] The hopper typically has a pair of sidewalls and a pair of end walls. The side walls are typically inclined. The sidewalls may be inclined at an angle between 40 to 50 degrees. Preferably the sidewalls have an inclination of 45 degrees. An exit may be located in one of the end walls. The hopper may have an open top. A catcher may be located on the hopper.
[0014] One or more walkways may be located on the outside of the hopper. A control device may be located on the outside of the hopper. The control device may be accessible via a walkway. A remote control device can also be used for better accuracy of placing particulate on top of the pipes. A remote control can also provide more visibility.
[0015] A vibration device may be located on the hopper. The vibration device may be operated when there is build up of particular matter on the walls of the hopper.
[0016] The storage conveyor may form a base of the hopper. The storage conveyor may extend at least the length of the hopper. Typically the storage conveyor extends through the exit.
[0017] The storage conveyor is normally a flat belt conveyor. However it should be appreciated that the storage conveyor may be either a V-belt or trough belt conveyor.
[0018] A metering device may be associated with the exit. The metering device may be used to vary the size of the exit. Typically the metering device includes a metering wall that can be raised or lowered.
[0019] The loading conveyor is typically a trough conveyor. The loading conveyor is normally angled between 25 and 35 degrees. Preferably the loading conveyor is angled at approximately 30 degrees.
[0020] The loading conveyor may be supported by support wheels. The support wheels are normally located adjacent an end of the loading conveyor.
[0021] The loading unit may include a delivery device that delivers sand onto the loading conveyor. The delivery device may be used to catch particular material that is delivered from trucks that carry particular material.
[0022] The delivery device may include one or more delivery conveyors that deliver particular material onto the loading conveyor. Normally there are two delivery conveyors. A delivery conveyor may be mounted onto each side of the loading conveyor to move particular material toward the loading conveyor.
[0023] The delivery device may include a support frame. The frame is typically used to mount the delivery conveyors. The frame may also form a crash barrier for vehicles delivering sand into the delivery device. At least one roller may be located on the frame. The roller may enable the wheels of a vehicle to spin the crash rollers if the wheels contact the delivery device.
[0024] The loading unit is able to be moved between an operational position in which the loading unit is able to load particular matter into the hopper and a transport position in which the loading unit located on the hopper.
[0025] The discharge conveyor may be extended transversely with respect to a longitudinal axis of the hopper. The discharge conveyor may be moved transversely with respect to the hopper.
[0026] A discharge conveyor drive may be used to move the discharge conveyor. The discharge charge conveyor drive may include a at least one rack and at least one pinion. However, it should be appreciated that other drives known in the art would be suitable. The height of the discharged conveyor may be varied. A height adjustment mechanism may be used for this purpose.
[0027] The discharge unit may include a discharge storage conveyor mount to mount the discharge conveyor. The height of the discharge storage conveyor mount maybe be varied with respect to the storage conveyor. A height adjustment mechanism that is attached to the discharge storage conveyor mount may be used for this purpose.
[0028] A splitting device may be located adjacent an end of the discharge conveyor to split the particular material into different streams. The splitter device may form part of a hood that is located adjacent the end of the discharge conveyor.
[0029] The discharge conveyor may be moved between an operational position in which the delivery conveyor is substantially flat to a transport position in which the discharge conveyor is folded.
[0030] The locomotion unit is typically located adjacent the storage unit. The locomotion unit normally includes a pair of tracks. However it should be appreciated that any rotational device such as wheels may be utilised.
[0031] A remote control unit may operate the locomotion unit, storage unit, loading unit or discharge unit. Typically the remote control unit can operate the storage unit, loading unit, discharge unit and locomotion unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] An embodiment of the invention, by way of example only, will now be described with reference to the accompanying drawings in which:
[0033] FIG. 1 is a perspective view of a pipeline padder in an operation position according to an embodiment of the invention;
[0034] FIG. 2 is a further perspective view of a pipeline padder according to FIG. 1 ;
[0035] FIG. 3 is a perspective view of a discharge unit according to an embodiment of the invention;
[0036] FIG. 4 is a perspective view of a discharge conveyor and associated hood according to an embodiment of the invention;
[0037] FIG. 5A is a perspective view of a the discharge conveyor mount in a downward position according to an embodiment of the invention;
[0038] FIG. 5B is a perspective view of a the discharge conveyor mount in a upward position according to an embodiment of the invention;
[0039] FIG. 6 is a perspective view of a discharge conveyor in a transport position according to an embodiment of the invention;
[0040] FIG. 7 is a perspective view of a pipeline padder in a transport position according to an embodiment of the invention; and
[0041] FIG. 8 is a perspective view of a pipeline padder in an operation position with a catcher.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] FIGS. 1 and 2 shows a pipeline padder 100 that it used to deliver fine particular materials such as sand into a trench to cover a pipeline. The pipeline padder 100 includes a storage unit 200 , a loading unit 300 , a discharge unit 400 and a locomotion unit 500 .
[0043] The storage unit 200 includes a hopper 210 and a storage conveyor 220 . The hopper 210 is used to store particular material such as sand. The hopper 210 includes two end walls 211 and two side walls 212 . The two side walls 212 have a portion of the side wall 212 which is inclined. The inclination of the side wall 212 is approximately at 45 degrees. Both end walls 211 are substantially parallel to each other. The hopper has an open top 213 . An exit 214 is located in an end wall 211 of the hopper 210 .
[0044] The storage conveyor 220 forms the base of the hopper 210 . Any particulate material that is located within the hopper 210 will slide down the inclined side walls 212 and sit on top of the storage conveyor 220 . The storage conveyor 220 is a flat belt conveyor. The storage conveyor 220 extends the length of the hopper through the exit 214 .
[0045] A metering device 230 is located over the exit 214 in the end wall 211 of the hopper 210 . The metering device 230 is used to meter the amount of particulate material that flows from the hopper 210 dependent on the speed of the storage conveyor 220 . The metering device 230 includes a metering wall 231 which is mounted within a pair of tracks 232 . Pair of metering hydraulic rams 233 are used to move the metering device 230 to vary the size of the exit.
[0046] A walk way 240 is located on each of the sides of the hopper 210 . A ladder 241 is associated with each walk way 240 so that a user is able to access the walkway. A control unit 242 is located on the side of the hopper and can be accessed via a walkway 240 .
[0047] A number of vibration devices (not shown) are located on the side walls 212 of the hopper 210 . These vibration devices are used to vibrate the side walls 212 of the hopper 210 to dislodge any excess particulate material that has built up on the side walls 212 of the hopper 210 .
[0048] The loading unit 300 is used to load particulate material into the hopper 210 . The loading unit 300 is located at one end of the hopper 210 . The loading unit 300 includes a loading conveyor 310 that extends from close to ground level to above the open top of the hopper 210 . The loading conveyor 310 is a trough conveyor and is angled at approximately 30 degrees. Two support wheels 311 are used to support an end of the loading conveyor. The support wheels 311 contact the ground and follow the contours of the ground as the pipeline padder 100 moves along the ground.
[0049] The loading unit 300 also includes a delivery device 320 that is mounted above the loading conveyor 310 . The delivery device 320 is used to deliver particulate onto the loading conveyor 310 . The delivery device 320 includes a support frame 321 which is used to support two delivery conveyors 322 . The delivery conveyors 322 are spaced apart so that there is a delivery aperture located between the delivery conveyors 322 for the delivery of particulate material from the delivery conveyors 322 onto the loading conveyor 310 . The support frame 321 also provides a crash barrier for vehicles that are loading particulate into the delivery device 320 . Two rollers 323 are located on the support frame 321 to enable vehicle tires to touch the delivery device 320 without substantially damaging the delivery device 320 . The delivery device 320 can be removed and attached to the loading conveyor 310 as is required.
[0050] The loading unit 300 also includes a lifting arm 330 which extends from adjacent a lower end of the loading conveyor 310 to a bottom of the storage unit 200 . The lifting arm 330 is pivotally connected to the storage unit 200 . A lifting ram 331 is pivotally attached to adjacent a top of the storage unit 200 and also pivotally attached to the lifting arm 330 at a position spaced away from the storage unit 200 .
[0051] The discharge unit 400 is used to distribute particulate material that is discharged from the hopper 210 by the storage conveyor 220 . The discharge unit 400 is located at an opposite end of the hopper 210 to that of the loading unit 300 . The discharge unit 400 includes a discharge conveyor 410 that is located below the exit 214 of the hopper 210 when in use. The discharge conveyor 410 is a trough conveyor that it orientated transversely with respect to the storage conveyor 210 . The discharge conveyor 410 is mounted on a discharge storage conveyor mount 420 .
[0052] The discharge conveyor 410 can be moved transversely with respect to the hopper 210 . That is, the discharge conveyor 410 can be moved so that particulate material can be delivered into a trench containing a pipeline that is spaced a distance away from the storage unit 200 . The discharge conveyor 410 is able to be moved to either side of the hopper 210 using a discharge charge conveyor drive 430 as shown more clearly in FIG. 3 .
[0053] The discharge charge conveyor drive 430 includes two racks 431 that are mounted on respective sides of the discharge conveyor 410 . Driven pinion wheels 432 are located on the discharge storage conveyor mount and engage the racks. Rotation of the driven pinions wheel 432 which engage respective racks 431 cause the discharge conveyor 410 to move transversely with respect to the hopper 210 .
[0054] A hood 440 is located at each end of the discharge conveyor 410 shown more clearly in FIG. 4 . The hood 440 is used to distribute particulate material that passes from the delivery conveyor 410 into the trench. The hood 440 is pivotally mounted to the discharge conveyor 410 so that the angle of the hood 440 can be varied with respect to the discharge conveyor 410 . A pivoting ram (not shown) is connected to the hood 440 and to the discharge conveyor 410 to pivot the hood with respect to the discharge conveyor 410 .
[0055] A splitter device 441 forms part of each of the hoods 440 . The splitter device 441 includes a central member 442 which splits the particulate material that passes from the discharge conveyor 410 into two separate material flows on each side of the central member 442 . Two deflection members 443 located on each side of the central member 442 deflect particulate material into the trench at different angles. Each of these deflection members 443 is in the form of a U shaped channel. However, it should be appreciated that the deflection devices 443 could be of other shapes and forms.
[0056] The discharge storage conveyor mount 420 is connected to the storage unit 200 via a lifting assembly 450 as shown in FIGS. 5A and 5B . The lifting assembly 450 is in the form of a scissor mechanism. A lifting ram 451 is centrally located within the lifting assembly 450 . An extension of the lifting ram 450 causes the lifting assembly to move the discharge storage conveyor mount 420 downwardly as shown in HG 5 A whilst retraction of the lifting ram causes 451 the lifting assembly 450 to move the discharge storage conveyor mount 420 upwardly as shown in FIG. 5B . Accordingly, the lifting assembly 450 enables the height of the discharge conveyor 410 to be varied with respect to the exit 214 . It would be appreciated that the lifting assembly 450 maybe of a different form.
[0057] The discharge conveyor 410 shown in more detail in FIG. 6 , is split into three separate sections 411 with each section 411 being pivotally connected to an adjacent section 411 . Two pivotally rams 412 extend between each adjacent section 411 . Extension of the pivotally rams 412 enables the discharge conveyor to be substantially flat. This is the discharge conveyors 410 operational position. Retraction of each of the pivotally rams 412 causes each section to be angled with respect to each adjacent section. This is the discharge conveyors 410 transport position.
[0058] The locomotion unit 500 is located adjacent the storage unit and is used to move the pipeline padder 100 . The locomotion unit 500 includes two tracks 510 that are driven by one or more associate hydraulic motors 520 . These motors 520 are also used to drive the loading conveyor 310 , storage conveyor 220 and discharge conveyor 410 . The hydraulic motors 520 are also used to drive all of the rams located on the pipeline padder 100 . The control unit 242 located on the hopper 210 is used to control the functions of the pipeline padder 100 . As an alternative, a remote control unit (not shown) can be used to control the functions of the pipeline padder 100 .
[0059] In use, a vehicle carrying particulate material is located adjacent to the delivery device 320 . The vehicle unloads particulate material from the vehicle into the delivery device 320 . The delivery conveyors 322 rotate towards each other so that any particulate material that contacts them is pushed toward the delivery aperture 323 . Particulate material then passes onto the loading conveyor 310 which transports the particulate material into the hopper 210 . The storage conveyor 220 is then operated to deliver particulate material from the hopper 210 onto the discharge conveyor 410 via the exit 214 in the hopper 210 . The particulate material on the discharge conveyor 410 is pitched into one of the two hoods 440 . The particulate material is split into discrete flows by the splitter device 441 and is delivered onto different sides of a pipe located within a trench.
[0060] Typically, the pipeline padder 100 is operated continuously whilst a vehicle is unloading particulate material into the delivery device. That is, the pipeline padder 100 is moving whilst unloading is occurring. The crash rollers 323 on the frame of the delivery device provide a safe guard for operators of a vehicle if they misjudge the speed of the pipeline padder 100 and the wheels of the vehicle touch the support frame 321
[0061] It should be appreciated that the loading conveyor 310 , storage conveyor 220 and discharge conveyor 410 can be operated independently. For example, a vehicle can deliver particulate material into the discharge device 320 which passes onto the loading and into the hopper 210 to fill the hopper 210 with particulate whilst the storage conveyor 220 and discharge conveyor 410 are not operational. Similarly, particulate material can be discharged from the hopper 210 using the storage conveyor 220 and discharge conveyor 410 without the loading conveyor 310 needing to be operated.
[0062] The discharge conveyor 410 can move from side to side to deliver particulate material to either side of the hopper 210 . This is often required if there are two trenches and two pipelines being laid simultaneously.
[0063] When the pipeline padder 100 is to be moved from one location to another, it is necessary to load the pipeline padder 100 onto a transport vehicle. In most countries throughout the world, the length and width dimensions of the pipeline padder 100 do not allow the pipeline padder being transported in its operational position. Accordingly, when transportation of the pipeline padder 100 is needed, modification of the pipeline padder is required by moving the lifting loading conveyor 210 and the discharge conveyor from their operational positions to their transport positions as shown in FIG. 7 . This modification occurs by first removing the delivery device 320 from the front of the loading conveyor 310 . The lifting ram 331 is retracted so that the loading conveyor 310 is lifted to a substantially horizontal position as well as slid forward to extend further over the hopper 210 . Once this has been completed, the loading conveyor 310 is in its transport position. The pivotally rams 412 on the discharge conveyor 410 are retracted so that each of the sections 411 are substantially perpendicular with respect to adjacent sections 411 . That is, the discharge conveyor 410 will form C-shape once the discharge conveyor is in its transport position. The pipeline padder 100 can then be loaded onto a transport vehicle to transport the pipeline padder 100 .
[0064] FIG. 8 shows the pipeline padder 100 having a catcher 250 attached to the hopper 210 . The catcher 250 assists in preventing particulate material from passing over the top of the hopper 210 after it passes from the loading conveyor 310 . The catcher 250 has two catcher sides 251 , a catcher end 252 and a catcher top 252 . The catcher 250 sits on top of the hopper 210 so that the two catcher sides 251 contact the hopper side walls 212 and the catcher end 252 contacts the hopper end wall 211 . The catcher 250 is located at one end hopper 210 opposite the loading conveyor 310 .
[0065] In this specification, the terms “comprise”, “comprises”, “comprising” or similar terms are intended to mean a non-exclusive inclusion such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.
[0066] It should be appreciated that various other changes modifications may be made to the embodiment described with that departed from the spiritual scope of the invention.
|
A pipeline padder comprising: a storage unit including a hopper for storing particulate material and a storage conveyor to remove particulate material from the hopper; a loading unit including a loading conveyor to load particulate material into the hopper; a discharge unit including a discharge conveyor for discharging particular material supplied by the storage conveyor; and a locomotion unit to move the storage unit.
| 4
|
This application is a continuation of U.S. application Ser. No. 09/358,791 entitled “WINDOW FRAME SYSTEM” and filed on Jul. 22, 1999, now U.S. Pat. No. 6,412,239.
FIELD OF THE INVENTION
The invention relates generally to improvements in the field of window framing systems for buildings of all types, and more particularly to such frames as are easily formed and readily adaptable to substantially any size or shape opening.
BACKGROUND OF THE INVENTION
As is well realized, there is currently a need for reducing manufacturing costs and simplifying the on-site construction of window framing systems. Metal window frames are increasingly used due to their strength, durability and ease of assembly. Such frames are commonly formed from different types or kinds of extrusions, which are manufactured by forcing molten metal through a die. By using differently shaped dies, nearly any shape of extrusion imaginable can be created.
Window frames have, in accordance with prior designs, required various different extrusions having differently-shaped configurations. That is, with respect to a particular window frame, not all of the peripheral frame members have been of the same configuration. Also, for many designs, window frame members must be cut at their ends to a 45 degree angle and then must be assembled at their corners to produce a window frame of a given size. All of this has contributed to the costliness of providing window frames for buildings of virtually any and all types.
In view of the foregoing, it is an object of the present invention to provide a window frame wherein all of the frame members are made of the same material, and have identically-shaped extruded configurations.
Another object of the present invention is to simplify the manner in which the structural frame members are joined or connected together and to increase the efficiency both in production and in assembly.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, a window frame is provided by arranging a plurality of support members to form a supporting structure. Each support member includes a plurality of identically-shaped structural members. Each of the structural members have a U-shaped channel defined by a base portion and two arms spaced apart on opposite lengthwise sides of the base portion. The arms extend from the base and have end portions turned inward that extend in a direction toward the base portion. The arms are substantially perpendicular to the base portion and can be of the same longitudinal length as the base portion. The end portions of both arms are substantially parallel to one another. The end portions of both arms are also in substantially parallel relationship to the base portion. A plurality of fasteners detachably secure the structural members in a configuration that is adapted to detachably mount a translucent barrier, such as a window made of glass. The fasteners can be adapted to nest in the end portions of both arms and to slidingly engage therewith.
The structural members of the window frame can be formed of metal and can be identically-shaped metal extrusions. Also, a gasket can be disposed between the structural members and the translucent barrier to prevent heat loss and access to weather elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of support members arranged to form the window frame of the present invention.
FIG. 2 is a front cutaway view of structural members arranged to form a support member of the present invention.
FIG. 3 is a front cutaway view of structural members arranged to form a support member that permits installation of adjacent windows or panel assemblies.
FIG. 4 is a front cutaway view of structural members arranged to form two support members to detachably mount translucent barriers in perpendicular relationship to one another.
FIG. 5 is a front cutaway view of structural members arranged to form a support member of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The window frame according to the present invention comprises support members shown in FIGS. 1-5. As will be readily apparent to those persons skilled in the art, the subject invention is not limited to any particular type or style of window frame. The support members may or may not be arranged in a closed pattern and may be arranged in different shapes such as a rectangle, square, triangle, etc., as appropriate or aesthetically desired.
FIG. 1 shows a typical window frame of the invention having a plurality of support members arranged to form a supporting structure. Each support member ( 1 ), ( 2 ), ( 3 ), ( 4 ), and ( 4 ( a )) includes a plurality of structural members joined together to form the sides of the support member. In accordance with the present invention, the structural members are identical to each other. The use of identically-shaped frame members reduces the manufacturing costs and simplifies the on-site construction of the window frame. While the support members are generally metal extrusions (e.g., aluminum or an alloy of aluminum) any other appropriate material which is capable of being formed with the desired identically-shaped configuration may be used.
Each of the structural members of the present invention have identically-shaped configurations. For example, support member ( 1 ) depicted in FIG. 2 includes a first structural member ( 5 ), a second structural member ( 6 ) and a third structural member ( 7 ). Each structural member has a U-shaped channel defined therein. Structural member ( 5 ) illustrates a U-shaped channel defined by a base portion ( 8 ), a first arm ( 9 ) and a second arm ( 10 ). In accordance with the invention, the first arm ( 9 ) and second arm ( 10 ) of structural member ( 5 ) have end portions ( 11 ) and ( 12 ) that are turned inward. The end portions extend in a direction toward the base portion ( 8 ). Fastener ( 13 ) is adapted to nest on the inside surface of the end portions ( 11 ) and ( 12 ) and to slidingly engage therewith.
FIG. 2 is a close-up cutaway view of support member ( 1 ) that is depicted in the window frame of FIG. 1 . FIG. 2 illustrates the configuration of structural members ( 5 ), ( 6 ) and ( 7 ) wherein the three structural members are in overlying relation to one another and are configured to form a support member ( 1 ). In accordance with this invention, the outside surface of arm ( 14 ) of structural member ( 6 ) is in overlying relation with at least a portion of the outside surface of the end portion ( 11 ) of structural member ( 5 ). The outside surface of arm ( 15 ) of structural member ( 6 ) is in further overlying relation with at least a portion of the outside surface of the base portion ( 16 ) of structural member ( 7 ).
FIG. 2 also illustrates that gaskets ( 17 ) and ( 18 ) are disposed between the two structural members ( 5 ) and ( 7 ) and translucent barrier ( 19 ). The gaskets ( 17 ) and ( 18 ) are made of any suitable materials as are known to those skilled in the art such as elastomeric materials. The gaskets ( 17 ) and ( 18 ) serve the purpose of preventing heat loss and access to weather elements.
As seen in FIG. 2, support member ( 1 ) is firmly held together by fastener ( 13 ). Fastener ( 13 ) is a combination of a channel nut ( 20 ), a threaded rod ( 21 ), a flat washer ( 22 ), a lock washer ( 23 ), and a nut ( 27 ). Threaded rod ( 21 ) is seen positioned in a hole drilled through the outside surface of base portion ( 16 ) of structural member ( 7 ) and into the defined U-shaped channel of structural member ( 7 ). The defined U-shaped channel serves as an area to place nut ( 24 ) on the threaded rod ( 21 ). The hole in which threaded rod ( 21 ) is positioned is located outwardly beyond the region in which translucent barrier ( 19 ) is disposed. Securing nut ( 24 ) to the distal end of the threaded rod ( 21 ) detachably secures structural member ( 5 ) to structural ( 7 ) with structural member ( 6 ) and translucent barrier ( 19 ) detachably secured therebetween.
Significantly, the translucent barrier and the structural members may be detachably secured in place by any well known fastening devices readily apparent to those persons skilled in the art. The invention herein defined is not limited to any particular type or style of fastener.
Referring to FIG. 3, it is seen how the window frame of FIG. 1 permits installation of adjacent windows or paneling assemblies. As shown in FIG. 3, a support member ( 4 ) includes a first structural member ( 25 ) and a second structural member ( 26 ). Here, first structural member ( 25 ) and second structural member ( 26 ) are not in overlying relationship to one another. Rather, first structural member ( 25 ) and second structural member ( 26 ) are each on opposite sides of the two adjacent translucent barriers ( 27 ) and ( 28 ). Each structural member ( 25 ) and ( 26 ) overlie the junction between the two translucent barriers ( 27 ) and ( 28 ) to define support member ( 4 ).
In this configuration, the outside surface of end portion ( 29 ) of structural member ( 25 ) is in overlying relation with at least a portion of translucent barrier ( 28 ). The outside surface of end portion ( 30 ) of structural member ( 25 ) is also in overlying relation to at least a portion of translucent barrier ( 27 ). The base portion ( 31 ) of structural member ( 26 ) is in overlying relation with at least a portion of translucent barrier ( 27 ) and is also in overlying relation with at least a portion of translucent barrier ( 28 ). Gaskets ( 32 ) and ( 33 ) are disposed between structural member ( 26 ) and translucent barriers ( 27 ) and ( 28 ). Also, gaskets ( 34 ) and ( 35 ) are disposed between structural member ( 25 ) and translucent barriers ( 27 ) and ( 28 ).
Similar to FIG. 2, support member ( 4 ) of FIG. 3 is firmly held together by fastener ( 73 ). Threaded rod ( 74 ) of fastener ( 73 ) is seen positioned in a hole drilled through the outside surface of base portion ( 31 ) of structural member ( 26 ) and into the defined U-shaped channel of structural member ( 26 ). The hole in which threaded rod ( 74 ) is positioned is located outwardly beyond the region in which adjacent translucent barriers ( 27 ) and ( 28 ) are disposed. Securing nut ( 75 ) to the distal end of threaded rod ( 74 ) detachably secures structural member ( 25 ) to structural member ( 26 ) with translucent barriers ( 27 ) and ( 28 ) detachably secured therebetween.
FIG. 4 illustrates a close-up cutaway view of support members ( 2 ) and ( 3 ) configured to detachably mount two translucent barriers ( 36 ) and ( 37 ) in perpendicular relationship to one another. The configuration of FIG. 4 illustrates that structural member ( 38 ) is included as one of three structural members forming support member ( 2 ) and that structural member ( 38 ) is also included as one of the three structural members forming support member ( 3 ).
In accordance with the invention, FIG. 4 illustrates that structural members ( 38 ), ( 39 ) and ( 40 ) are in overlying relation to one another and are configured to form support member ( 2 ). The outside surface of arm ( 41 ) of structural member ( 38 ) is in overlying relation with at least a portion of the outside surface of base portion ( 42 ) of structural member ( 39 ). The outside surface of arm ( 43 ) of structural member ( 38 ) is in further overlying relation with at least a portion of the outside surface of end portion ( 44 ) of structural member ( 40 ).
As set forth in FIG. 4, structural members ( 38 ), ( 45 ) and ( 46 ) are also in overlying relation to one another and are configured to form support member ( 30 ). The outside surface of arm ( 47 ) of structural member ( 46 ) is in overlying relation with at least a portion of the outside surface of base portion ( 48 ) of structural member ( 38 ). The outside surface of arm ( 49 ) is in further overlying relationship with at least a portion of the outside surface of end portion ( 50 ) of structural member ( 45 ).
Similar to FIG. 2, support members ( 2 ) and ( 3 ) of FIG. 4 are firmly held together by fasteners ( 51 ) and ( 52 ). Threaded rod ( 53 ) of fastener ( 52 ) is seen positioned in a hole drilled through the outside surface of base portion ( 42 ) of structural member ( 39 ) and into the defined U-shaped channel of structural member ( 39 ). The hole in which threaded rod ( 53 ) is positioned is located outwardly beyond the region in which translucent barrier ( 37 ) is disposed. Securing nut ( 54 ) to the distal end of threaded rod ( 53 ) detachably secures structural member ( 39 ) to structural member ( 40 ) with structural member ( 38 ) and translucent barrier ( 37 ) detachably secured therebetween. Gaskets ( 59 ) and ( 60 ) are disposed between the two structural members ( 38 ) and ( 45 ) and translucent barrier ( 36 ).
Threaded rod ( 57 ) of fastener ( 52 ) is seen positioned in a hole drilled through the outside surface of base portion ( 48 ) of structural member ( 38 ). The hole in which threaded rod ( 57 ) is positioned is located outwardly beyond the region in which translucent barrier ( 36 ) is disposed. Securing nut ( 58 ) to the distal end of threaded rod ( 57 ) detachably secures structural member ( 38 ) to structural member ( 45 ) with structural member ( 46 ) and translucent barrier ( 36 ) detachably secured therebetween. Gaskets ( 59 ) and ( 60 ) are disposed between the two structural members ( 38 ) and ( 45 ) and translucent barrier ( 36 ).
FIG. 5 is a close-up cutaway view of support member ( 4 ( a )) that is depicted in the window frame of FIG. 1 . FIG. 5 illustrates a configuration of structural members ( 61 ), ( 62 ) and ( 63 ) that is very similar to the configuration of structural members ( 5 ), ( 6 ) and ( 7 ) as depicted in FIG. 2 .
As such, FIG. 5 illustrates the configuration of structural members ( 61 ), ( 62 ) and ( 63 ) wherein the three structural members are in overlying relation to one another and are configured to form a support member ( 4 ( a )). The outside surface of arm ( 64 ) of structural member ( 62 ) is in overlying relation with at least a portion of the outside surface of the end portion ( 65 ) of structural member ( 61 ). The outside surface of arm ( 66 ) of structural member ( 62 ) is in further overlying relation with at least a portion of the outside surface of the base portion ( 67 ) of structural member ( 63 ). FIG. 1 illustrates that gaskets ( 68 ) and ( 69 ) are disposed between the two structural members ( 61 ) and ( 63 ) and translucent barrier ( 37 ).
As seen in FIG. 5, support member ( 4 ( a )) is firmly held together by fastener ( 70 ). Threaded rod ( 71 ) of fastener ( 70 ) is seen positioned in a hole drilled through the outside surface of base portion ( 67 ) of structural member ( 63 ) and into the defined U-shaped channel of structural member ( 63 ). The hole in which threaded rod ( 71 ) is positioned is located outwardly beyond the region in which translucent barrier ( 37 ) is disposed. Securing nut ( 72 ) to the distal end of threaded rod ( 71 ) detachably secures structural member ( 61 ) to structural member ( 63 ) with structural member ( 62 ) and translucent barrier ( 37 ) detachably secured therebetween. Gaskets ( 68 ) and ( 69 ) are disposed between the two structural members ( 61 ) and ( 63 ) and translucent barrier ( 37 ).
Although the present invention has been described with particularity, it will be apparent to those of ordinary skill in the art at the time the invention was made that various modifications may be made to the described invention without departing from the spirit or scope thereof. Accordingly, the scope of the present invention is intended to be defined by the appended claims.
|
The present invention is a window frame wherein all of the structural members are formed with the same substantially identically-shaped configuration a metal extrusion. A plurality of structural members are arranged to form a supporting structure. Each structural member has a U-shaped channel defined by a base portion having a first arm and a second arm spaced apart on opposite lengthwise sides of said base portion. The first and second arms extending from said base portion have end portions turned inward and extending in a direction toward said base portion. Fasteners detachably secure the plurality of structural members into a configuration adapted to detachably mount a translucent barrier within the supporting structure formed by the structural members.
| 4
|
BACKGROUND OF THE INVENTION
The present invention relates to exercise equipment in general, and more particularly to a power training arrangement of the type provided with a driving motor which drives, via a transmission, a moving element which is connected with a gripping member.
For the training of athletes and the rehabilitation of handicapped or incapacitated persons, there are already known various constructions or power training arrangements, in which a moving element is driven by a motor. In such an arrangement, the moving element is provided with a gripping portion or member, which can be engaged by the hand or by the foot of the user of the arrangement, in order to slow down or stop the movement of the moving element. In many instances, the moving element is driven via a crank mechanism, so that it moves at a constant speed of the motor with different velocities at different times, and also the power transmission ratio varies in time. However, such known power training arrangements have the drawback that the individual phases of a movement cycle take different amounts of time, so that the user must adjust himself or herself to the time-varying velocity of movement of the moving element. Moreover, only movements of less than 180° can be performed by the moving element of the power training arrangement, so that an optimum training over the entire movement range (for instance, crossing of arms) is not possible.
Other known power training arrangements are provided with weights which are to be lifted by the user via a transmission mechanism in the various recommended or required ways, or springs which are to be tensioned. Power training arrangements of this variety render it possible, as a rule, to achieve muscle loading only in one direction, while muscle loading in the opposite direction cannot be exercised. At the very least, a fully effective training during a "negative" phase of movement is not possible, since the weight or the loading remains the same, whereas the muscle exerts up to two times the original force during the negative phase. Herein, the term "negative" as applied to phase of movement or to movement means an attempt at maintaining a muscle contraction against a load or a weight.
Thus, it may be seen that the heretofore proposed power training arrangements leave much to be desired in terms of structure but especially in the way in which they can be used to train or rehabilitate the users of such arrangements. Moreover, such known arrangements, more often than not, are rather expensive.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide a power training arrangement which does not possess the disadvantages of the known power training arrangements.
Still another object of the present invention is to develop a power training arrangement of the type here under consideration, which would lend itself for use in versatile muscle training.
It is yet another object of the present invention to construct the arrangement of the above type in such a manner that the full driving force of the driving motor is transmitted to the moving element at all times, so that the muscle being trained is loaded to a sufficient extent during the negative phase.
A concomitant object of the present invention is to design the above arrangement in such a manner as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet highly reliable in operation.
In keeping with these objects and others which will become apparent hereafter, one feature of the present invention resides in a power training arrangement which comprises a support; a moving element mounted on the support for movement in a predetermined path and including a gripping member; and means for moving the moving element in the predetermined path, including a regulated reversible motor including an output member, means for controlling the operation of the reversible motor, and a proportional transmission which proportionally transmits the movement of the output member of the reversible motor to the moving element. Advantageously, the reversible motor is either a rotor-slippage electric motor, or a direct current electric motor. The power training arrangement of the present invention as described so far has the advantage that, due to the provision of the controlling means, which is preferably constructed as electronic equipment, it is possible to control the operation of the driving motor electronically with respect to the muscle group to be trained so as to adhere to a predetermined regime.
In the power training arrangement of the present invention, the motor output force is transmitted via a proportional transmission to the moving elements, which is thus driven with a torque that remains constant over time, and which pivots or turns about a stationary axis. The motor can be controlled with respect to its speed of operation or number of revolutions per minute, in order to select various speeds of movement of the moving element. The user of the arrangement then has the choice to act with his or her musculature on the gripping member of the moving element in such a manner as to either enhance the motor-caused movement of the moving element, or to counteract such motor-caused movement (negative phase). Inasmuch as the motor is a regulated rotor-slippage motor or direct current motor, its speed of operation can be varied within predetermined limits by the force exerted by the user. Consequently, the user is able to retard or accelerate the movements of the moving element with his or her muscle force. For the protection of the user, the sense of rotation of the motor can be reversed in response to the action of respective end switches at the very latest when the moving element has reached a certain angular position. In this manner, there is accomplished a cyclical reversal of the movement of the moving element, which is otherwise caused by the electronic control means. In this manner, the user can stress his or her musculature alternatingly in the positive and in the negative phase while maintaining his or her body position.
It is also possible to accomplish a regulation of the speed of operation of the motor in order to perform the movements of the moving element either with a different constant speed or with a speed which changes in dependence on the region of operation of the muscle being trained. To this end, the motor output shaft or the transmission can be provided with a tachogenerator which generates a signal corresponding to the actual speed of operation of the motor, and this actual speed is then compared with a signal representative of the desired speed of the motor. A control signal is then produced from the difference between the values of such actual and desired speed signals, this control signal then controlling the electric current supplied to the motor in such a sense that the motor speed of operation corresponds to the desired speed of operation independently of the applied muscular force. The applied muscular force may be indicated by a display or indication device. The signal of the display or indicating arrangement can be derived from the electric current consumption of the motor by means of a measuring transmitter, sensor or transducer capable of measuring the loading of the motor, or it can be derived from a torque measuring apparatus.
According to another advantageous concept of the present invention, the power training arrangement comprises a support; two moving elements, each mounted on the support for movement in a different predetermined path and including a gripping member; and means for moving the moving elements in the predetermined paths thereof, including a motor including an output member, means for controlling the operation of the motor, and a transmission including two output shafts each of which transmits the movement of the output member of the motor to one of the moving elements. In this manner, it is possible for the user to simultaneously train both of his or her arms, in that each of the arms engages a different one of the two moving elements. Advantageously, these two moving elements are driven in opposite senses and with the same phase relative to one another. This means that the moving elements extend parallel to one another in their lower and upper positions, and point in different directions between these end positions.
The transmission may advantageously include a first and a second gear each mounted on one of the output shafts for joint rotation therewith and for meshing with the respective other gear. Then one of the output shafts is mounted on the support for axial displacement, together with that one of the gears which is mounted thereon, for disengaging the one gear from the gear which is mounted on the respective other shaft, and for removing the moving element of the one shaft from the predetermined path of movement of the moving element of the the respective other shaft. This particular construction renders possible a selective utilization of only one of, or of both, of the moving elements. Now, when only one of the moving elements is being used, then the other moving element is uncoupled from this active moving element and, as a result, it is no longer driven by the motor. On the other hand, the uncoupled moving element is brought into its inactive position, in which it does not present a disturbing appearance.
It is further advantageous when, in accordance with another advantageous facet of the present invention, there is provided a power training arrangement which comprises a support; a moving element mounted on the support for movement in a predetermined path and including a gripping member; means for moving the moving element in the predetermined paths thereof, including a motor including an output member, means for controlling the operation of the motor, and a transmission which transmits the movement of the output member of the motor to the moving element; a horizontal bar component; a slide mounted on the horizontal bar component for vertical movement; at least one deviating roller rotatably mounted on one of the support and the horizontal bar component; a tow cable trained about the deviating roller and having two end portions; and means for connecting one of the ends of the tow cable to the slide and the other of the ends to the moving element. As a result of the provision of the tow cable, the movement of the moving element is transmitted to the slide, which is then periodically lowered and lifted on the vertical posts of the horizontal bar component. The user of the arrangement can then act on this slide with his or her arms or legs, in order to either maintain the slide in position against the effect of the motor movement, or to lift the slide while supporting the effect of the movement of the motor. In this context, it is advantageous when the slide is constructed as a weight carrier and when there is further provided at least one weight selectively carried by the slide. Inasmuch as the motor causes the position of the slide to periodically change, the muscle movements are performed in various stretch conditions. It is also possible to press the slide upwardly with the shoulders, while simultaneously stretching or exercising the leg muscles.
Advantageously, the power training arrangement further comprises a bench arranged underneath the horizontal bar component. It is also advantageous when there is further provided a cable deviating device disposed at a lower region of the horizontal bar component, an additional tow cable having one end connected to the slide and another end remote from the slide, the additional tow cable being trained about the cable deviating device, and a handgrip secured to the other end of the additional tow cable and enabling the user of the arrangement to pull the other end of the additional tow cable upwardly or at an incline against the force exerted by the motor.
Last but not least, the power training arrangement is advantageously so constructed that the support includes a housing which accommodates the motor and the transmission and has a front wall, and the transmission includes at least one output shaft extending tnrough the front wall. Then, there is further provided a seat guide track arranged in front of the front wall and extending parallel to the front wall, and a seat displaceably supported on the guide track. Especially in this connection, it is advantageous when the horizontal bar component is rigidly connected to the housing and extends transversely with respect to the front wall.
The power training arrangement of the present invention renders it possible to perform numerous different exercises, in positions which may vary with time. This arrangement is particularly suited for rehabilitation purposes.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will now be discussed in more detail with reference to the accompanying drawing in which:
FIG. 1 is a perspective view of a power training arrangement of the present invention; and
FIG. 2 is a partially sectioned front elevational view taken in the direction of the line II--II of FIG. 1, but showing a somewhat modified construction of the power training arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing in detail, and first to FIG. 1 thereof, it may be seen that the reference numeral 10 has been used therein to identify a housing of a power training arrangement, which is adapted to stand on a floor or any other horizontal support surface in the position illustrated in the drawing. The housing 10 is substantially rectangular in top plan view and accommodates a driving motor 11 and a transmission 12. The transmission 12 drives a first output shaft 13 which is rotatably mounted in the housing 10 and carries a spur gear 14 (see FIG. 2) which is connected to the first output shaft 13 for joint rotation therewith, for instance, by a key, by a spline or a plurality of splines, or the like. As also illustrated in FIG. 2, this spur gear 14 meshes with another spur gear 15 which is mounted for rotation about a common axis on a second output shaft 16. The two output shafts 13 and 16 extend parallel to one another and are arranged at the same elevation above the horizontal support surface in the illustrated position of the power training arrangement. Free end portions of the output shafts 13 and 16 project outwardly of a front wall 17 of the housing 10.
A first moving element 18 is secured to the free end portion of the first output shaft 13. The first moving element 18 has the form of a lever which extends from the first output shaft 13 substantially perpendicular to the axis of the first output shaft 13. A second moving element 19 is secured to the output shaft 16 in an analogous manner. A gripping member 20 may be mounted on each of the moving elements 18 and 19. The gripping member 20 is shown to be constituted by a slide sleeve, from which there extends an arm 21 which extends substantially parallel to the respective output shaft 13 or 16. The slide sleeve of the gripping member 20 is fixed to the respective moving element 18 or 19 by means of a screw which is not illustrated in any particular detail in the drawing. The gripping member 20 has the purpose of being gripped by, for instance the hand of, the user of the power training arrangement, in order to exert muscular force on the respective output shaft 13 or 16.
The second output shaft 16 is axially shiftable in and opposite to the direction of an arrow 22 which is indicated in FIG. 1 of the drawing. Thus, the second output shaft 16 can be displaced more into the housing 10 in the direction of the arrow 22 in order to shift the other spur gear 15 out of meshing engagement with the one spur gear 14. In the inwardly displaced position of the second output shaft 16, which is indicated in FIG. 1 of the drawing, the second moving element 19 is not being driven and, simultaneously, it is removed out of the trajectory of movement of the first moving element 18. When the second moving element 19 is in its operating position, the two moving elements 18 and 19 are driven in opposite directions or senses. The motor 11 is operated in such a manner that the two moving elements 18 and 19 respectively move through an angle of about 180°. A non-illustrated end switch of any known construction is actuated when the respective end position is reached, and the direction of rotation of the motor 11 is reversed in response to such actuation.
The moving elements 18 and 19 are illustrated in FIG. 1 in their lower end positions, even though the moving element 19 is shown in its inactive condition. The user of the power training arrangement can grip the gripping members 20, which may be mounted on each of the moving elements 18 and 19, with both of his or her hands, in order to counteract the movements of the moving elements 18 and 19 with the force exerted by his or her muscles. As a result of the reciprocating movements of the moving elements 18 and 19, there is alternatingly achieved a positive and a negative muscle stressing, that is, the very same muscle or group of muscles alternatingly acts in a braking and in an accelerating manner on the respective movement element 18 or 19.
An auxiliary frame 23 is mounted in the front of the front wall 17 of the housing 10 of the power training arrangement. The auxiliary frame 23 is provided, in the vicinity of the floor or other horizontal support surface in the illustrated position of the power training arrangement, with a guiding track 24 for a movable carriage 25. The movable carriage 25 carries a seat 26 and it can be arrested, by a non-illustrated arresting device of any known construction, in one of a plurality of different positions along the guide track 24. Thus, the user of the power training arrangement is seated at a distance frontwardly of the front wall 17 of the housing 10 and can adjust the position of the seat 26 which is best suited for the respective exercise by moving the carriage 25 along the guide track 24. Inasmuch as the auxiliary frame 23 is secured to the housing 10, the reaction force applied by the user of the power training arrangement to the seat 26 is transferred via the carriage 25, the guide track 24, and the auxiliary frame 23 to the housing 10 of the power training arrangement. Therefore, it is not necessary to individually positionally fix the individual parts of the power training arrangement on the floor or other horizontal support surface, because all forces encountered during the use of the power training arrangement are accepted and transmitted by the power training arrangement itself.
The power training arrangement is further provided with a horizontal bar component 27 which is arranged laterally next to the housing 10 of the power training arrangement and is rigidly connected with such housing 10 by means of at least one connecting bar 28. The horizontal bar component 27 consists of a rigid rectangular frame including two vertical columns 29, each of which is provided with a vertical guiding slot 30. One end of a horizontally extending slide bar 31 is received in each of the slots 30. The slide bar 31 is constructed as a weight carrier. Corresponding associated weights, which may be exchangeably mounted as desired in the slide bar 31, are indicated by the reference numeral 32.
In the kind of use of the power training arrangement of the present invention which is illustrated in FIG. 2 of the drawing, one end of a tow cable 33 is connected to a weight 32 supported on the slide 31. The tow cable 33 is trained about a diverting roller or pulley 34 which is turnably mounted on a transverse horizontal upper bar of the horizontal bar component 27, and about a guiding roller or pulley 35 which is turnably mounted on the housing 10 of the power training arrangement, and extends all the way toward, and is connected to, a holder 36 which is removably mounted on the first moving element 18. When the first moving element 18 is pivoted by the turning of the first output shaft 13, the slide 31 is lifted or lowered in the horizontal bar component 27, depending on the sense and extent of turning of the first output shaft 13. The point of attachment of the tow cable 33 to the moving element 18 via the holder 36 is chosen in such a manner that the slide 31 performs a complete lifting or lowering movement on the horizontal bar component 27 during the movement of the moving element 18 through 180°.
The user of the power training arrangement can then attempt to lift the slide 31 with the weights 32, or to prevent the lowering of the slide 31 with muscular force. Inasmuch as the slide 31 moves in a vertical path, the muscle stressing occurs at different levels.
When the tow cable 33 is being used and when, accordingly, the holder 36 is mounted on the first moving element 18, the second moving element 19 is in its inactive or disengaged position, that is, the second output shaft 16 is displaced into the housing 10, so that the other spur gear 15 is not being driven. In this condition, it is also possible to let the first output shaft 13 to constantly rotate in the same sense or direction of rotation.
As also shown in FIG. 2 of the drawing, a bench 37 is provided on the horizontal bar component 27 underneath the slide 31. The user of the power training arrangement can then use this bench 37 to either lie or sit thereon in order to perform the required exercises.
In the form of use of the power training arrangement of the present invention which is illustrated in FIG. 1 of the drawing, the bench 37 is removed. The tow cable 33 extends from the upper deviating roller or pulley 34 to a lower deviating arrangement 38 which is arranged at the lower region of the horizontal bar component 27, and from there to a handgrip 39. The user of the power training arrangement can engage the handgrip 39 with both of his or her hands, in order to pull the end of the tow cable 33 up.
The user of the power training arrangement can perform, among others, the following exercises on the horizontal bar component 27:
1. Bench pressing; during this exercise, the user of the power training arrangement lies on the bench 37, in order to press with his or her arms against the slide 31.
2. Knee bending; during this exercise, the user of the power training arrangement stands below the horizontal bar component 27, without the bench 37 being present, the user supporting the slide 31 with his or her shoulders and pushing the weights 32 up with bent knees.
3. Back lifting; during this exercise, the user of the power training arrangement stands in front of the horizontal bar component 27, bends forward and lifts the weights 32 upwardly.
4. Leg pressing; during this exercise, the user of the power training arrangement lies on the bench 37 and presses with his or her feet from underneath against the slide 31.
It may be seen that various other exercises may also be performed using the power training arrangement of the present invention, if need be, with other auxiliary implements. The arrangement of the present invention is extremely versatile and renders it possible to stress various muscles in the various positions, in each instance, in bending and extending directions or senses.
While the present invention has been described and illustrated herein as embodied in a specific construction of a power training arrangement, it is not limited to the details of this particular construction, since various modifications and structural changes are possible and contemplated by the present invention. Thus, the scope of the present invention is to be determined exclusively by the appended claims.
|
A power training arrangement includes two moving elements which can be coupled with one another and which are jointly driven by a rotor-slippage electric motor or by a direct current motor. The user of the arrangement can then either brake or accelerate the movements of the two moving elements with his or her muscular force. A tow cable may be connected with one of the moving elements and may transmit periodic forces to a horizontal bar element and particularly to a slide mounted on the horizontal bar element for upward and downward movement and carrying a selected number of weight elements. The construction of the arrangement of the present invention renders it possible to accomplish a dynamic training.
| 0
|
TECHNICAL FIELD
The present invention is directed to a method for manufacturing an article of footwear from foam, and in particular, for molding an article of footwear upper having stiffness variations throughout by combining different grades of foam and applying heat and pressure to mold the foam to the desired shape.
BACKGROUND OF THE INVENTION
Numerous articles of footwear and methods for manufacturing the same are known in the prior art. The simplest of these constructions includes stitching together overlapping layers of leather or cloth to form an upper covering for the foot and then using an adhesive to attach a preformed outsole. The adhesive may be applied with a brush, or alternatively, as in U.S. Pat. No. 3,988,797 to Tornero, a shoe upper may be integrally joined to a preformed rubber outsole by placing both the shoe upper and outsole in a mold cavity and then injection molding an outsole adherent therein in order to join the outsole to the upper. Other constructions include forming an injection molded outsole and/or midsole and integrally joining the upper during the molding process of the sole unit. For example, U.S. Pat. No. 4,245,406 to Landay et al. discloses an athletic shoe in which an upper and a preformed rubber outsole are joined by a foamed polyurethane, injection-molded midsole. The shoe is manufactured by treating the inner surface of a preformed rubber outsole to prepare it for bonding to polyurethane, inserting the treated sole into the bottom of a mold, mounting a preformed upper on a last, lowering the last and closing the mold, with the last spaced above the rubber outsole, injecting a charge of foamable polyurethane between the outsole and the last, and allowing the polyurethane to foam under self-generated pressure to form the midsole and to bond with the outsole and upper.
Each of the above constructions utilizes an injection molding process to form all or part of the sole unit or to adhere the sole to the preformed upper. Further methods of construction, such as those disclosed in U.S. Pat. No. 4,150,455 to Fukuoka and U.S. Pat. No. 4,266,314 to Londner epouse Ours, extend the injection molding to improve the upper portion of the article of footwear. Fukuoka disposes an upper base in a mold and then injects a synthetic resin material for the upper into the upper molding cavity. After the upper portion of synthetic resin is cooled, the upper is transferred to the mold for the sole and the sole portion of synthetic resin is injected into the sole molding chamber. After the sole portion of synthetic resin is cooled, the finished molded shoe of synthetic resin is removed from the mold. Londner epouse Ours discloses a lining of leather or other suitable material for the shoe upper onto which are overmolded two overlapping portions of plastic materials of different types. The first layer of plastic material injection molded in direct contact with the lining and covers the entire upper while the second injection molded portion constitutes a stiffening reinforcement that surrounds only the rear counter of the upper and a thin intermediate sole. An outer wearing sole is then added to the article of footwear. The injection molding processes utilized in the above prior art, whether to mold only the sole or portions of the upper as well, have the disadvantages of requiring an additional finishing step for the upper of the article of footwear, injecting parts having difficult areas to fill while being limited to only one foam material per pour; these requirements limited the available foams to those which provided acceptable cosmetics, bonding strength and split tear resistance, no air bubbles, exposure to the elements survival, whiteness/color retention, and were generally flash control foams, such as DALTOPED and similar polyester and polyether based elastomer systems offered by ICI Americas Inc.
SUMMARY OF THE INVENTION
The present invention overcomes these disadvantages by providing a method of making a finished article of footwear upper and midsole from a foam material, but without injection molding. The method includes the steps of forming a foam shell for the article of footwear by wrapping a foam side wall material with variable physical properties around the periphery of a base, a portion of which is preferably foam, positioning the foam shell on a last, securing the last and the foam shell within a mold and closing the mold. Heat and pressure are then applied to mold the foam shell to the shape of the exterior and then, after opening the mold, the molded article of footwear is removed from the last. The method further includes the steps of forming an inner bootie and inserting the inner bootie over the last prior to positioning the foam shell thereon. Thus, the step of applying heat and pressure molds the inner bootie with the foam shell to form the article of footwear. The inner bootie includes an inner liner and a foam overlay which is attached to selected regions of the inner liner. Thus, the variance in the thickness of the foam allows the stiffness of the article of footwear to be adjusted in selected regions. The present invention provides the ability to position and provide the correct amount and type of material for each particular location as opposed to the injection process that is limited to one material provided everywhere.
The foam shell may be formed with a foam side wall having a uniform thickness throughout or with varying thicknesses and/or varying materials at selected regions. The foam sidewall also may be comprised of foams of varying densities and variances of rigidity. The step of applying heat and pressure while the last is positioned in the mold forms regions of increased foam thickness in the article of footwear as well as regions of decreased foam thickness in the article of footwear. An exterior layer of material may also be provided over the foam side wall to form the exterior surface of the article of footwear. In a further embodiment, a selected region of foam may also be removed entirely from the foam side wall to form an opening in the side wall. The application of heat and pressure thus forms a region of no foam thickness in the article of footwear by molding directly together the liner of the inner bootie and the exterior layer of material on the foam side wall by fusing together their adhesive linings.
The present invention thus provides a method for forming an article of footwear to virtually the exact shape of the last and allows a variety of sizes of the article of footwear to be manufactured merely by changing the last within the mold. For example, for a given size of a foam shell, variations of up to two or three full sizes can be accomplished by changing the size of the last. The present invention thereby provides a method for forming a custom molded article of footwear for an individual wearer, once a last corresponding to the user's foot has been made.
BRIEF DESCRIPTION OF THE DRAWINGS
The above description and other objects, advantages, and features of the present invention will be more fully understood and appreciated by reference to the specification and accompanying drawings, wherein:
FIGS. 1(A) and 1(B) are plan views of a foam sidewall and a foam bottom prior to assembly of the foam shell in accordance to the present invention;
FIG. 2 is a perspective view of an inner bootie according to the present invention;
FIG. 3 is a perspective view of an assembled foam shell with the inner bootie of FIG. 2 therein;
FIG. 4 is a cross-sectional view of the assembled foam shell and inner bootie disposed on a mold core;
FIG. 5 is a diagrammatic view of the mold core assembly of FIG. 4 positioned within a mold;
FIG. 6 is a cross-sectional view of an assembled foam shell and inner bootie according to a further embodiment of the present invention;
FIG. 7 is a cross-sectional view of an assembled foam shell and inner bootie according to a still further embodiment of the present invention;
FIG. 8 is a cross-sectional view of an assembled foam shell according to another embodiment of the present invention;
FIG. 9 is a side elevational view of an article of footwear formed in accordance with the present invention; and
FIG. 10 is a cross-sectional view taken generally along the line 10--10 of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An article of footwear manufactured in accordance with the present invention is illustrated generally by the reference numeral 10 in FIG. 9. Article of footwear 10 preferably includes a molded finished upper 12, a molded midsole unit 14, an optional cushioning unit (not shown), and an outsole 16. The finished upper 12 and midsole 14 are molded from a foam material and the outsole 16 is then adhered to the bottom surface thereof after the molding process. Alternatively, it is possible to attach outsole 16 to upper 12 and midsole 14 and mold all components together at the same time to provide a completely finished shell. Article of footwear 10 is designed to have stiffness variations in localized regions of the upper and midsole dependent upon the desired cushioning and support for a specific region. As described in detail below, the variation in the stiffness of the article of footwear may be obtained by utilizing different grades of foam material, or different foam materials, the same foam material with different density, or the same foam material with a different quantity in the localized regions, and forming the upper 12 and midsole 14 through an application of heat and pressure to mold the foam to the desired shape.
Referring to FIGS. 1-3, upper 12 and midsole 14 are constructed from a foam sidewall 18 and a foam base 20 which are combined together to form a foam core 22. Foam base 20, depending on the materials used to form it, their thickness and the type of shoe being manufactured, can function as an insole, or a combined insole and midsole. Foam sidewall 18 and foam base 20 as illustrated are one-piece components made of EVA, polyolefin foam and having a uniform thickness although, as discussed below, a non-uniform thickness may also be utilized. Other foams which can be used to form the sidewall 18 and/or base 20 include DuPont EVA 6301 (75% VA) and CIL EVA (18% VA). Foam side wall 18 is wrapped around foam base 20 and the two parts are adhered together, preferably only along the bottom edge and the toe area, to form foam core 22. The exterior surface of foam side wall 18 may include a material surface layer 19 which will form the finished exterior surface of the upper 12 and which acts to strengthen the foam and provide for cosmetics and environmental factors. Material layer 19 may be a solid color as illustrated or include any type of ornamentation, outer counters, lace locks, etc., or decoration which makes the finished upper more appealing to the user and which achieves a durable, flexible, and abrasion resistant exterior surface. An inner foam bootie 24, as shown in FIG. 2, is preferably inserted within foam core 22 to provide a dual density foam upper. Inner bootie 24 includes an inner liner 26 and a foam overlay 32. Inner liner 26 is stitched or otherwise attached to a bottom liner 34 to form a stretchable, glove-like liner for a mold core. The material used to form liners 26 and 34 is preferably DuraPlush®, a synthetic woven material having a soft, pliable and comfortable interior surface 28 for contact with the foot and a urethane adhesive applied to the exterior surface 30 to promote the bond between the liner exterior surface 30 and foam core 22 or foam overlay 32. As shown, selected regions generally along the sides of exterior surface 30 are covered by foam overlay 32 in order to provide more cushioning to the ankle and instep regions of the foot. Foam overlay 32 is preferably a foam such as EVA that will form a molded shape or urethane that will not form a molded shape, and may be more or less dense than the foam used to form foam core 22 depending on the location. Thus, during the molding process, as discussed below, foam overlay 32 may or may not compress to the same degree as the foam of foam core 22, depending on the foam material, and an article of footwear 10 is formed having stiffness variations in the upper 12.
Each of the components discussed above and the additional parts discussed below, must be primed or prepared with an adhesive prior to placement within the mold such that they will adhere during the molding process. It is not necessary to securely bond the components together, as long as they are correctly positioned such that when the mold closes the components are in the correct orientation to each other.
Thus, properly prepared foam core 22 and foam bootie 24 are then disposed on the last or mold core 36 in preparation for the molding process. As shown in FIGS. 4 and 5, mold core 36 is mounted within a mold 38, shown as a two-part mold in the preferred embodiment, and a pin 40 is used to secure the foam core 22 within mold 38. Either plastic inserts, depressions or holes cut in the foam core 22 may also be used to accurately position the foam core within the mold cavity 38 and/or around the last or mold core 36 by mating these elements with projections or depressions in the last or mold core.
Once the mold cavity 38 is closed, heat and pressure are applied in order to activate the adhesive primer and mold the foam to the desired form. This provides exceptional bonding of the components and eliminates individual pressing or attachment operations or the need for perfect matching parts to assemble the finished article of footwear. In a preferred embodiment of the invention, heat and pressure are applied simultaneously for a predetermined time and then they are both turned off and cooling is established to allow the foam to set. The applied heat is generally between 250° F. and 350° F., with the preferred temperature being approximately 300° F. The applied pressure is generally between 50 and 150 psi, with the preferred pressure being approximately 100 psi. The heat and pressure are applied for approximately 15 minutes and then allowed to cool so that the foam will set. Then, the mold is opened and the molded article of footwear 10 is removed. Since the foam core is molded directly around the mold core 36, the process of the present invention creates an article of footwear having a footshape virtually identical to the shape of the last or mold core 36. This process not only produces an article of footwear with a seamless shoe interior but also allows for a variety of sizes and customized articles of footwear merely by using a different last or mold core 36 within the same outer mold 38.
After removal from mold 38, the edges of the molded article of footwear 10 are trimmed, if necessary, dependent upon the shape of the foam core 22. The material layer 19 and foam sidewall 18 can be formed "tall" to extend past the desired height of the article of footwear during the molding process and then be trimmed off after the molding process is complete. Alternatively, foam core 22 can be carefully finished such that material layer 19 and foam sidewall 18 do not extend past the desired height of the article of footwear. In this instance, the present invention provides more finished and softer edges once the molding process is complete. Further, material layer 19 can be formed to extend past side wall 18, and then folded over the upper foam edge to give a finished edge surface. In each case, once the edges are properly finished, all that remains to complete the article of footwear is to attach an instep covering portion and adhere an outsole.
Referring to FIG. 4, a cross-section through the preferred foam core 22 illustrates the uniform thickness thereof and the positioning of foam overlay 32 in only selected regions of the upper. There are, however, several options for varying the preformed foam core to meet particular conditions. As shown in FIG. 6, foam core 22 may be provided with thinner portions 42 and thicker portions 44 in order to provide localized changes in the stiffness of the molded upper 12. That is, a thinner portion 42 of foam material provides a softer area to the upper 12, such as for greater flexibility, cushioning, comfort, and the like, while a thicker portion 44 of foam material provides a stiffer area to the upper, such as for ankle support, forefoot support, and medial/lateral stiffeners.
In accordance with the present invention, localized changes of the foam material can achieve the above benefits and also allow for specific non-thermoset areas, e.g., areas where it is not desired for the foam to compress and set to a give shape, such as the footbed. Non-thermoset areas are formed merely by utilizing a foam material which will not compress under the applied conditions of heat and pressure, such as polyurethane which will not compress at a temperature of 300° F. and a pressure of 100 psi, for example. Alternatively, as discussed further below, an area of the foam may be removed from the foam side wall 18 to provide an opening therein. Thus, during the molding process, the area of removed foam will form a non-thermoset area due to the lack of foam material at the localized area. The base forming the insole or combined insole/midsole may also be varied to customize or vary the footbed. Stiffness may be enhanced in certain areas, or the entire foot contact surface may be given a soft feel by using a top layer of non-thermoset material.
In a further embodiment of the present invention, the performance characteristics of molded upper 12 may be locally changed by positioning various additional elements with the foam core prior to the molding process. Referring to FIG. 7, a universally-shaped thermoplastic reinforcement 45 such as a generally shaped heel counter may be positioned between foam sidewall 18 and foam bootie 24 or, alternatively, reinforcement 45' such as an ankle support may be positioned on the exterior surface of foam sidewall 18. After the molding process, the universally or generally shaped reinforcement takes on the precise desired shape. Placement of the reinforcements or other additional elements exterior to the foam sidewall 18 or even between layers of foam on the upper, the present invention provides a layer of molded foam between the reinforcement and the foot of the user. The intervening layer of foam acts to protect the user's foot from localized pressure and/or impacts from external loads. Other universally-shaped thermoplastic or additional parts such as closure elements, eyelet reinforcements, ankle support devices, forefoot stability supports, etc., may also be disposed between the foam layers prior to the molding process and then formed to the desired shape during the molding process along with the foam core 22. Thus, the need for stock-fitting matching components after the molding process is eliminated.
Still further, foam core 22' may be formed from a foam wall 18' and a filler element 46 as shown in FIG. 8. In this embodiment of the present invention, wall 18' is wrapped around the lateral side, bottom surface, and medial side of the mold core 36, thereby eliminating the use of a foam base as in FIG. 1. A foam filler element 46 is either already attached to the mold core 36 or to foam wall 18'. Filler element 46 wraps around the mold core from the front to the rear to thereby completely surround the toe area and heel area of the mold core 36 prior to the molding process.
A finished article of footwear 10 in accordance with the present invention is illustrated in FIGS. 9 and 10. Molded upper 12 may include closure elements 48, thinner portions 42, thicker portions 44, as well as finishing elements such as the instep covering layer 50 that may be stitched or otherwise attached to the molded upper 12. Outsole 16 is also adhered to the finished molded upper 12 and midsole 14. As discussed above, molded upper 12 also includes a non-thermoset area 52 having no compressed foam between material layer 19 and inner liner 26 because a corresponding area of foam was removed from foam sidewall 18 prior to the molding process. This use of removed foam can form decorative patterns in the molded upper 12, such as the triangular elements illustrated, as well as provide extremely soft, lightweight, and flexible areas on the upper. Article of footwear 10, as a whole, is extremely lightweight due to the integration of the components and the assembly thereof in accordance with the present invention.
It can be readily understood that a variety of alternate or equivalent methods, processes and manufacturing techniques could be used to derive the article of footwear of the present invention. It will also be obvious to those of ordinary skill in the art that numerous modifications may be made without departing from the true spirit and scope of the present invention, which is to be limited only by the appended claims.
|
A method of making an article of footwear includes the steps of forming a foam shell for an article of footwear by wrapping a foam side wall around the periphery of a base, positioning the foam shell on a last, securing the last and the foam shell within a mold and closing the mold, applying heat and pressure to thereby mold the foam shell to the shape of the last, and then opening the mold and removing the molded article of footwear from the last. In a preferred embodiment, the method further includes the steps of forming an inner bootie, having an inner liner and a foam overlay, and inserting the inner bootie over the last prior to positioning the foam shell thereon. The inner bootie includes the inner liner with the foam overlay attached to selected regions thereof. The step of applying heat and pressure thereby includes molding the inner bootie with the foam shell to form the molded article of footwear.
| 1
|
RELATED CROSS-REFERENCING
[0001] The present invention claims the priority of European Patent Application No. 10 174 853.1 filed on Sep. 1, 2010, 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 device for generating a cooling air flow in a preferential flow direction for cooling electrical components, particularly electro-optical components such as e.g. LEDs. The present invention particularly relates to the integration of a device of the above type into a cooling body for cooling electrical components, particularly electro-optical components such as e.g. LEDs.
[0004] 2. Description of the Prior Art
[0005] On the sector of land and air vehicles, efforts have been under way for many years to install LEDs as a replacement of conventional illuminants of the type with filaments or of the gas discharge type. This trend is favored by the recent introduction of high-performance LEDs on the market, which due to their relatively high light intensity can also be used e.g. for headlights of automobiles and in aircraft. Further, there exist illumination applications wherein the light is switched on only for a short time, while, however, due to the power density and the available (cooling) surface, there is a risk of inadmissible overheating of the illuminant or lamp in the course of the typical operating period. This is the case e.g. in runway, turn-off, taxi, landing and take-off lights of aircraft equipped with LED illuminants.
[0006] Presently, for cooling LED illuminants, use is made inter alia of passive systems, i.e. cooling bodies, by which the LEDS or the component parts heated by LED illuminants are exposed to the ambience via an enlarged surface. Also such cooling bodies, however, cannot prevent the risk of overheating of the LED illuminants. For this reason, in situations where a predetermined temperature limit has been reached, the LED illuminants will be dimmed so that the power input will be reduced, thus taking into consideration the fact that the current-carrying capacity of LEDs tends to decrease with increasing temperature.
[0007] An apparatus for cooling an electronic device is described in EP-A-1 020 9121 A2 and includes a casing formed with a plurality of air intake/exhaust holes through which air will pass. A plate-type mobile member is installed to vibrate in said casing and divides an inner space of the case into an upper space and a lower space. An elastic support film is fixed in the casing to support the mobile member and has a bulged portion capable of being elastically deformed. A driving device is provided for vibrating the mobile member. By the vibration of the mobile member, air in the upper and lower spaces of the casing is exchanged with outside air through the air intake/exhaust holes which are each provided with valves.
[0008] A valveless micropump is known from DE 42 23 019 C1. Further cooling devices for cooling e.g. electronic components are disclosed in each of WO-A-2010/044047, US-A-2007/0272392 and US-A-2006/0048918.
[0009] It is an object of the invention to improve the cooling of electrical components, particularly electro-optical components such as e.g. LEDs, notably by providing a reliably operating device for generating a cooling air flow in a preferential flow direction for cooling the electrical components.
SUMMARY OF THE INVENTION
[0010] According to the invention, the above object is achieved by a device for generating a cooling air flow in a preferential flow direction for cooling electrical components, particularly LEDs, wherein said device comprises
a first and a second channel wall having mutually confronting inner sides, and an oscillation drive means for generating an oscillating movement of at least a partial region of at least one of said channel walls in the direction toward the other channel wall and away therefrom, the inner side of at least one of said two channel walls having a surface structure designed for anisotropic flow, said surface structure having a smaller flow resistance coefficient in the preferential flow direction than in a direction extending at an angle to the preferential flow direction and particularly in a direction extending opposite to the preferential flow direction.
[0014] In accordance with the invention, an air flow is generated between two channel walls, notably in a preferential flow direction. In the context of the invention, the term “channel wall” is to understood as denoting a wall delimiting an air volume or, more generally, a fluid volume. The two channel walls provided according to the invention need not be connected to each other, so that the region between the channel walls can be open toward the ambience via at least one edge of each channel wall. Preferably, the two channel walls provided according to the invention are the parallel cooling plate elements of a cooling body.
[0015] According to the invention, it is provided that at least one of the two channel walls or an additional element between the two channel walls can at least in partial regions thereof be subjected to an oscillating movement. For this purpose, the device of the invention comprises an oscillation drive unit. Said partial region of at least one of the two channel walls (or of an element arranged between them) which can be subjected to an oscillating motion, will now oscillate in a direction extending orthogonally to the extension of the channel wall. Starting from a specific time and point along the air flow, the air will be urged away in all directions in a uniform manner, namely when impinging onto that channel wall in whose direction the oscillating partial region is presently moving. The inner side of at least one of the two channel walls (or the outer side of the element arranged between the channel walls) is provided with an anisotropic surface structure. Under the aspect of flow technology, this surface structure has an anisotropic effect on an air flow sweeping along the surface structure. This means that the surface structure has a lower flow resistance in the preferential flow direction than in a direction extending at an angle to the preferential flow direction and in a direction opposite to the preferential flow direction. Thus, by the effect of the integrated anisotropic surface structure, there is generated an anisotropic air drag coefficient or air-flow drag coefficient which will hinder the “air-wave” to propagate at a uniform speed and will guide the air into the preferential flow direction. Generated in this manner is a net volume and mass flow which preferably, in relation to the orientation of the device in the mounted state, will be guided upward, i.e. in the direction of the air flow generated by the natural convection.
[0016] By the oscillation movement, there is first generated an air movement between the channel walls. In the region opposite the oscillating partial region, this air movement will be deflected, namely generally to all sides. By the effect of the anisotropic surface structure, the thus deflected air flow will now be largely deflected into the preferential flow direction, or, expressed in a different manner, the air will flow primarily in the preferential flow direction. On the whole, a net air flow is generated in the preferential flow direction.
[0017] Thus, according to the arrangement proposed by the invention, the air movement oscillating orthogonally to the extension of the channel walls is deflected into an air movement between the two channel walls, said air movement between the two channel walls streaming at different rates in the most different directions parallel to the channel walls and between the latter while, however, due to the anisotropic surface structure, a net or preferential flow direction is obtained. When applying this concept to the cooling plate elements of a cooling body, the device according to the invention can enhance the natural convection in that the cooling plate elements are vertically oriented and the anisotropic surface structure is oriented in such a manner that the preferential flow direction is pointing upward.
[0018] An essential advantage of the device of the invention resides in its reliable cooling effect, while the need for moving component parts, such as e.g. inlet and/or outlet valves operating in opposite senses to each other, is obviated (except for said oscillating partial region of at least one of the channel walls and respectively of an element arranged therebetween). Particularly, no active cooling devices such as e.g. ventilators are required. In aircraft industry, such active cooling measures are presently not admissible because it is feared that the cooling would be considerably impaired in case of a fallout of the active cooling devices such as e.g. ventilators and the like. Apart from the above advantage, the device of the invention and the cooling method of the invention will guarantee their functionality even under extreme ambient conditions. The influence of such ambient conditions or extreme external influences is to be expected on the landing gear of aircraft where the device would be exposed to aggressive media, dirt, flying stones or gravel, icing and vibration. A further advantage of the device of the invention is to be seen in that no complex electronic control process is required and that the oscillation drive unit can be fed directly by the vehicle or aircraft power supply system at different frequencies. The cooling concept provided by the invention is inexpensive and is easily put into practice under the constructional aspect while working with utmost reliability.
[0019] At lower temperatures, the stiffness of the channel wall(s) will increase in those regions where said oscillating partial regions are located. Thereby, the effectiveness of the air movement is reduced, which, however, is not critical because lower temperatures will also require less cooling performance. At higher temperatures, by contrast, the flexibility of the oscillating partial regions of the channel wall(s) will increase, namely exactly when a maximum cooling performance is required.
[0020] A further advantage of the device of the invention is to be seen in that the anisotropic surface structure results in an enlargement of the surface area of the channel wall(s). This is advantageous particularly if the anisotropic surface structure is provided on an element of the cooling body which is dissipating heat to the ambience.
[0021] Apart from the above effects, a further considerable cooling effect is obtained by the feature that, by the (rectangular) deflection of the air flow in the area of the oscillating partial region of at least one of the channel walls and respectively of the element optionally arranged therebetween, the “aerodynamic boundary layer” on the channel wall and respectively on the oscillating partial region is substantially thinner. Herein, an “aerodynamic boundary layer” is to be understood as a nearly immobile air layer arranged directly on the surface of the channel wall and respectively the partial region. Since the movement of air in this region is normally very slight, there is thus only a limited heat exchange between the respective component part and the ambience. Thus, by reduction of the thickness of this effective boundary layer, the heat exchange is improved. By “breaking up” this boundary layer, as achieved by the functionality of the inventive device, the air flowing through the channels can become considerably warmer and thus can dissipate considerably more energy than would be the case in a purely “parallel” flow through the channels.
[0022] According to an advantageous embodiment of the invention, it is provided that the anisotropic surface structure comprises a plurality of projections extending from the channel wall, each of said projections having a front side facing in a direction opposite to the preferential flow direction and a rear side facing in the preferential flow direction, and that the geometry of said front side of a protrusion is adapted to generate of a higher flow resistance coefficient than the geometry of said rear side of the protrusion.
[0023] A possible embodiment of said anisotropic surface structure is to be seen in that said front sides of the protrusions are formed by front flanks and the rear sides of the protrusions are formed by rear flanks, and that said rear flanks are steeper than said front flanks. This is realized e.g. in that the protrusions extend substantially transversely to the preferential flow direction and form a sawtooth profile.
[0024] As an alternative to the above serially arranged “ramps” extending transversely to the preferential flow direction and in combination forming a sawtooth profile, the anisotropic surface structure can also be realized by triangular or part-cylindrical protrusions. In case of triangular protrusions, these are arranged on the surface with their bases facing in a direction opposite to the preferential flow direction. In case of protrusions having a round or cylindrical circumferential surface in a partial region of their circumference while otherwise being flattened, these protrusions are to be arranged with their flattened portions facing in the preferential flow direction. As to the geometric configuration of the protrusions, it generally applies that, for fluid flowing over the surface structure, they offer a smaller flow resistance in the preferential flow direction than in a direction opposite to the preferential flow direction or, in broader terms, in a direction extending at an angle to the preferential flow direction.
[0025] Until now, the invention has been described for the case that at least one of the two channel walls is provided with an oscillating partial region. Suitably, both channel walls comprise oscillating partial regions, while these oscillating partial regions are movable for oscillation in opposite senses.
[0026] For the invention, it basically plays no role where exactly said anisotropic surface structure is arranged between the channel walls. Suitably, however, the channel wall which is movable in an oscillating manner should be provided with the anisotropic surface structure on its inner side.
[0027] A further advantageous embodiment of the invention is characterized by a third channel wall having an inner side facing toward the two other channel walls, the second channel wall being arranged between the first and the third channel wall and having two (inner) sides opposite to the third and respectively the first channel wall, said two sides being provided with an anisotropic surface structure, with either (i) the second channel wall or (ii) the first and third channel wall or (iii) all three channel walls being movable in an oscillating manner.
[0028] As an alternative, a further advantageous embodiment of the invention can be characterized by a third channel wall having an (inner) side facing toward the two other channel walls, the second channel wall being arranged between the first and the third channel wall and having two inner sides opposite to the third and respectively the first channel wall, said two inner sides being provided with an anisotropic surface structure, the inner faces of the first and the third channel wall being provided with a respective anisotropic surface structure, with either (i) the second channel wall or (ii) the first and third channel wall or (iii) all three channel walls being movable in an oscillating manner.
[0029] In these two alternative embodiments of the invention, it can be additionally provided that the preferential flow directions in the two intermediate spaces between the second channel wall and the first and respectively the third channel wall are identical or opposite to each other.
[0030] The oscillatable partial region of a channel wall and respectively of another element arranged between two channel walls is suitably formed as an elastic membrane operatively connected to the oscillation drive unit. The operative connection between the oscillation drive unit and the membrane can be provided, apart from the option of using a mechanical connection, particularly as a magnetic coupling wherein, in the latter case, the oscillation drive unit will generate a magnetic field and said membrane comprises a magnetic material which will be exposed to said magnetic field, wherein said membrane is movable in an oscillating manner as a result of magnetic and eddy-current effects.
[0031] The oscillatable channel wall comprises on at least one of its sides, particularly externally of the membrane, said anisotropic surface structure.
[0032] As already mentioned above, the device of the invention can be suitably integrated into the cooling plate elements of a cooling body. Thus, in this case, the two channel walls are formed by two adjacent cooling plate elements of the cooling body. If the device of the invention comprises three channel walls as provided according to one of its preferred embodiments, these channel walls are formed by three adjacent cooling plate elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] A full and enabling disclosure of the present invention, including the best mode thereof, enabling one of ordinary skill in the art to carry out the invention, is set forth in greater detail in the following description, including reference to the accompanying drawing in which
[0034] FIG. 1 is a lateral view of an LED light for an aircraft,
[0035] FIG. 2 is a rear view of the LED light with a cooling body arranged thereon,
[0036] FIG. 3 is a front perspective view of the light,
[0037] FIG. 4 is a horizontal sectional view taken along the plane IV in FIGS. 2 and 3 ,
[0038] FIGS. 5 and 6 illustrate the generation of the air flow in the preferential flow direction between respectively two cooling plate elements of the cooling body, these Figures showing the cooling body in sectional view taken at the level of line V in FIG. 1 ,
[0039] FIG. 7 is a sectional view taken along line VII-VII in FIG. 1 , i.e. a plan view onto the anisotropic surface structure with sawtooth profile according to the views in FIGS. 2 , 5 and 6 ,
[0040] FIG. 8 is a plan view of the anisotropic surface structure according to a an alternative embodiment, and
[0041] FIG. 9 is a plan view of the anisotropic surface structure according to a further alternative embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] In FIGS. 1 to 3 , an LED aircraft light 10 is shown in lateral, rear and perspective view. Said aircraft light 10 comprises a housing 12 provided with a receiving chamber 14 . In said receiving chamber 14 , a plurality of LEDs 16 are arranged whose light will be fed into (TIR) light conductors 18 which in turn will radiate this light to the outside via a lighting plate or a transparent cover 20 . It should be noted that the use of TIR is not absolutely necessary for the invention. Within the framework of the invention, also other LED illuminants with or without light-conducting optical elements can be used.
[0043] In the present embodiment, said LEDs 16 are high-performance LEDs and are held on a common support plate 22 . Said support plate 22 is in thermally conductive contact with a cooling body 24 which can form said housing 12 —or a part thereof—of aircraft light 10 and which comprises individual cooling plate elements 26 . Said cooling body 24 is provided with a device for generating, between said cooling plate elements 26 , air flows in a preferential flow direction 28 (see the flow arrows in FIGS. 2 , 3 , 5 , 6 and 7 ).
[0044] For this purpose, two of said cooling plate elements 26 are on both of their sides provided with anisotropic surface structures 30 . These two cooling plate elements 26 are hereunder referred to by the term “channel wall” 32 , the two adjacent cooling plate elements 26 being referred to as the first and second channel walls 34 , 36 . Said channel wall 32 is then the third channel wall. In addition to the anisotropic surface structures 30 , the third channel walls 32 comprise partial regions 38 , arranged to be moved in an oscillating manner, in the form of membranes 40 which can be brought into oscillating movements with the aid of an oscillation drive means 42 . Said oscillation drive means 42 are electro-magnetic coils 43 provided to generate alternating magnetic fields to which said membranes 40 are exposed. Due to magnetism and eddy-current effects, the membranes 40 will be caused to oscillate transversely to the extension of the channel walls 32 , 34 , 36 . For this purpose, the membranes 40 are provided with magnetically sensitive materials.
[0045] With reference to FIGS. 5 and 6 , the functionality of said device for generating air flows between the channel walls 32 , 34 , 36 will be described hereunder. The coil 43 will be driven by an electronics unit 44 , and the magnetic field of coil 43 will have an alternately attractive and repulsive effect on membrane 40 . FIG. 5 shows the situation where the membrane is attracted. In this situation, the air volume at 46 will be moved in the direction toward channel wall 36 where the air will be deflected in all directions. Since channel wall 32 comprises, on its side facing toward channel wall 36 , the anisotropic surface structure 30 , the major part of the deflected air flow will be conveyed in the direction of arrows 48 , 50 , i.e. in the preferential flow direction 28 . The anisotropic surface structure 30 comprises a plurality of protrusions 52 which in the present embodiment are respectively wedge-shaped and which together form a sawtooth profile. Each protrusion comprises a flat flank 54 and a steep flank 56 . With respect to the preferential flow direction 28 , said flat flank 54 is arranged upstream of said steep flank 56 . When viewed in the preferential flow direction 28 , protrusions 52 are positioned both upstream and downstream of the membrane, the latter being arranged substantially centrally on channel wall 32 . Thus, under the aspect of flow technology, the protrusions 52 arranged upstream of membrane 40 will have a different effect on the air flow from that of the protrusions 52 arranged downstream of membrane 40 . The protrusions 52 arranged upstream of membrane 40 will offer a higher flow resistance to the air flow deflected on channel walls 36 than the protrusions 52 arranged down-stream of membrane 40 . Thus, in other words, the major portion of the air flow deflected on channel wall 36 due to the deflective capacity of membrane 40 will flow in the preferential flow direction 28 ; only a small portion (see arrows 58 ) will flow e.g. oppositely to the preferential flow direction.
[0046] On that side of membrane 40 which in the situation according to FIG. 5 is facing away from oscillation drive unit 42 , an underpressure will be generated, thus now causing air to flow from all sides along channel wall 34 toward the center of the wall. These individual air flows in turn will be exposed to the anisotropic surface structure 30 of channel wall 32 which will have the same effect as described above. The major portion of the inflowing air will flow in the direction of arrow 60 , i.e. in the preferential flow direction 28 while e.g. only a smaller portion (see arrow 62 ) will flow oppositely to the preferential flow direction 28 .
[0047] FIG. 6 shows the situation in which the membrane 40 is repelled by the oscillation drive unit 42 . With reference to the arrows 48 , 50 and 58 , it can be seen also here that the major portion of the air will flow in the preferential flow direction 28 . A corresponding situation will occur on the other side of membrane 40 , which side is facing toward the oscillation drive unit 42 .
[0048] In the light 10 according to this embodiment, the above described mechanism has a dual effect, as evident e.g. from FIG. 2 . This because the cooling body 24 is provided with two cooling plate elements 26 and respectively channel walls 32 which comprise anisotropic surface structures 30 .
[0049] FIG. 7 is a plan view of the anisotropic surface structure 30 .
[0050] Illustrated in FIGS. 8 and 9 are two alternative embodiments of anisotropic surface structures 30 ′, 32 ″. As far as the other components of the lighting device which are shown in FIGS. 8 and 9 are identical with the components of the lighting device according to FIGS. 1 to 7 , they are marked by the same reference numerals in FIGS. 8 and 9 as in FIGS. 1 to 7 .
[0051] In FIG. 8 , the anisotropic surface structure 30 ′ comprises individual projections 52 ′ which in plan view have the shapes of partial circles. Said projections 52 ′ comprise flattened sides 56 ′ oriented toward the preferential flow direction 28 , and convexly curved sides 54 ′ oriented in a direction opposite to the preferential flow direction 28 . Also by this arrangement and orientation of the projections 52 ′, there is formed a surface structure 30 ′ which, for air flowing along the surface, offers a smaller flow resistance in the preferential flow direction 28 than in a direction opposite to the preferential flow direction 28 .
[0052] In FIG. 9 , the projections 52 ″ of the anisotropic surface structure 30 ″, when seen in plan view, have a triangular shape wherein the bases 56 ″ are oriented toward the preferential flow direction 28 while the tips 54 ″ are oriented in a direction opposite to the preferential flow direction 28 . Again, there is formed a surface structure 30 ″ having an anisotropic effect under the aspect of flow technology, which, for air flowing along the surface, offers a smaller flow resistance in the preferential flow direction 28 than in a direction opposite to the preferential flow direction 28 .
[0053] In the lighting device 10 according to the above described embodiments, the mechanism for generating air flows between the cooling plate elements of the cooling body in the preferential flow direction, can be provided as just a single unit or as a plural number of units and/or be used e.g. in combination with other cooling mechanisms and measures for prevention of overheating of the LEDs. According to FIGS. 4 , 5 and 6 , the cooling body comprises a chamber filled with a PCM material 70 . The PCM material 70 , as long as it is in a solid state of aggregation, will in a first phase serve for cooling the LEDs. As soon as the PCM material 70 has taken up a quantity of heat so large that the material has fully transitioned into the liquid state of aggregation, its cooling effect has been exhausted and the further cooling can be performed by the cooling mechanism described further above in that, between the cooling plate elements, an air flow is generated in the preferential flow direction 28 for supporting the normal air flow by convection from below to above. Should the cooling performance not be sufficient, the LEDs may be dimmed to prevent them from overheating.
[0054] Although the invention has been described and illustrated with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the true scope of the invention as defined by the claims that follow. It is therefore intended to include within the invention all such variations and modifications as fall within the scope of the appended claims and equivalents thereof.
|
The device for generating a cooling air flow in a preferential flow direction for cooling electrical components, particularly LEDs, comprises a first and a second channel wall ( 34,36 ) having mutually confronting inner sides, and an oscillation drive means ( 42 ) for generating an oscillating movement of at least a partial region ( 38 ) of at least one of said channel walls ( 34,36 ) in the direction toward the other channel wall and away therefrom. The inner side of at least one of said two channel walls ( 34,36 ) has a surface structure ( 30 ) designed for anisotropic flow, which has a smaller flow resistance coefficient in the preferential flow direction ( 28 ) than in a direction extending at an angle to the preferential flow direction ( 28 ) and particularly in a direction extending opposite to the preferential flow direction ( 28 ).
| 5
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part of Co-pending application Ser. No. 10/632,573, which was filed Aug. 1, 2003, entitled “DISINFECTING ARTICLE WITH EXTENDED EFFICACY”, and incorporated herein.
FIELD OF THE INVENTION
[0002] The present invention relates to disinfecting articles providing effective cleaning and antimicrobial treatment of microbiologically contaminated surfaces. More particularly, it relates to the use of sealable housings and aqueous hypohalite compositions associated with a hypohalite stable and hypohalite non-degrading absorbent substrate that preserves the antimicrobial efficacy of the disinfectant article over representative storage conditions.
BACKGROUND OF THE INVENTION
[0003] There is a need for a stable cleaning and disinfecting wipe and article that is capable of cleaning and removing residues from soiled surfaces while simultaneously destroying undesirable microorganisms, e.g. bacteria, mold, viruses, prions and the like that colonize on common surfaces with which people come into contact, such as door knobs, countertops, toilet seats, floors, beds, walls, and the like.
[0004] Hypohalite releasing compounds, such as the hypohalites and related compounds that release active forms of hypohalite and/or halogens, are extremely effective disinfectants capable of destroying a wide range of microorganisms. Hypohalite releasing antimicrobial compounds, and in particular the hypohalites, constitute a class of strong chemical oxidants possessing both cleaning and bleaching properties in addition to their antimicrobial properties making them superior to other disinfectants, such as quaternary ammonium biocides. The hypohalite class of chemical oxidants act to rapidly oxidize susceptible substances found in inorganic, organic and biological materials, rendering them more easily removed from surfaces, and in the case of colored or pigmented materials, bleaching them to white or colorless end products resulting in effective cleaning and stain removal from soiled surfaces. Owing to their strong oxidizing capability, hypohalites also posses inherent disinfection properties and additionally possess desirable characteristics including excellent aqueous solubility, mobility and a highly dissociative ionic nature. A further advantage of the hypohalite class with regard to disinfectancy, is the speed and efficacy with which they attack microorganisms and either destroy them or render them non-viable following very short contact times. Yet a further advantage of the hypohalites is the wide susceptibility of many different types of microbial pests to their strong oxidizing potential and essentially the absence of any known microbe to develop an effective resistance against the action of these materials.
[0005] Typically, microbiologically contaminated surfaces seldom comprise only the microorganisms themselves, but include the presence of soils and other residues, including organic, inorganic and biological residues associated with the source of the microbiological contamination. These residues, including, for example, saliva, bodily is fluids, blood and common soils such as foods, oils and dirt, not only host microorganisms, but can act to shield and protect the microorganisms from the disinfectant action of non-hypohalite disinfectant materials.
[0006] One seeming disadvantage of the hypohalite class of materials is their susceptibility to decomposition, including self-decomposition and reactive decomposition owing to the interaction of the hypohalites with the substrates and materials, which they contact during packaging and storage. Particularly in the case of pre-wetted wipes, the disinfecting hypohalite composition is impregnated onto and interacts with the absorbent carrier substrate during storage. Hence, freshly prepared solutions or disinfectant articles utilizing these materials are typically required to ensure adequate activity for ensuring effective disinfection of surfaces. Attempts have been made in the past to provide a convenient disinfectant article by absorbing a hypohalite solution onto an absorbent towel or carrier. However, prior attempts have failed to produce a hypohalite releasing disinfectant wipe with sufficient stability to ensure suitable disinfecting efficacy at time of use, particularly following typical storage times and/or less than ideal storage conditions representative of real world environments encountered in the home, office, business, hospital or field where needed.
[0007] U.S. Pat. No. 4,998,984, to McClendon, describes a premoistened disinfectant article impregnated with a disinfectant composition that may include sodium hypochlorite and is prepackaged in a liquid impermeable container. U.S. Pat. No. 5,087,450, to Lister, describes a viral wipe to remove organic material having viral contaminants from a surface which consists of a porous gauze pad lined with a non-porous flexible fluid impervious barrier layer fused to one side and impregnated with 10% sodium hypochlorite and stored in a protective foil, plastic and paper layered package. Lister notes that the 10% sodium hypochlorite solution becomes unstable within a short period of time.
[0008] U.S. Pat. No. 5,985,302, to Dorr, et al., describes a method for inactivating HIV infected blood which involves first swabbing a contaminated surface with a first aqueous calcium and/or sodium hypochlorite impregnated fibrous towelette, followed by a second swabbing with a second towelette impregnated with a neutralizing sodium thiosulfate solution. However, the Dorr, et al. example exhibits poor stability and complete loss of disinfectant power even of a dry calcium hypochlorite/methyl cellulose system freshly dissolved in water to produce a disinfecting solution after only 10 days storage at 50° C. U.S. Pat. No. 6,313,049, to Heady, describes a pre-packaged fabric-saturated absorbent sheet with the U.S. food-industry legal chlorine disinfectant solution and discloses the use of cotton, paper or sponge sheets as absorbents. U.S. Pat. No. 6,387,384, to Probert, describes a prepackaged towelette bearing sodium hypochlorite and discloses the use of gauze or bandage material as absorbents.
[0009] The prior art fails to provide a stable disinfectant article that maintains acceptable stability after storage times and storage conditions typical of actual usage conditions encountered in the real world. For instance, most commercial product distribution channels result in products ageing several months following manufacture before being placed on sale, followed by significant delays before actually being used. During this time, products are seldom stored under ideal conditions, but rather are exposed to temperature variations typical of the home, field and industrial environment. Most significantly, the prior art fails to disclose suitable absorbent carrier substrates with acceptable stability or a reliable means for selecting an appropriate absorbent material suitable for extended stability of aqueous hypohalite disinfectant articles to ensure reliable antimicrobial efficacy when needed.
[0010] Clearly, there remains an unmet need for an aqueous hypohalite disinfecting article with improved stability that can provide the required antimicrobial efficacy for disinfecting microbiologically contaminated surfaces, particularly following typical storage times and/or less than ideal storage conditions representative of real world environments encountered in the home, office, business, hospital or field where needed.
SUMMARY OF THE INVENTION
[0011] The present invention relates to a disinfecting article, a housing system for disinfecting articles, and disinfecting composition, for cleaning and disinfecting surfaces, with improved stability and extended efficacy for cleaning and disinfecting surfaces with residues such as foods, dirt, microorganisms and many other common contaminates. The disinfecting article is preferably a wipe. In one embodiment of the invention, the disinfecting article comprises an aqueous hypohalite releasing composition and an absorbent carrier containing said aqueous hypohalite releasing composition, wherein said absorbent carrier comprises fibers having a denier of 1.5 or greater. In another aspect of the invention, the disinfecting article comprises an aqueous hypohalite releasing composition comprising a surfactant and an absorbent carrier containing said aqueous hypohalite releasing composition. In another aspect of the invention, the housing system for disinfecting articles comprises a disinfecting article comprising an aqueous hypohalite releasing composition and an absorbent carrier containing the aqueous hypohalite releasing composition, and a sealable container for storing and dispensing said disinfecting article.
[0012] The disinfectant articles provide a sufficient amount of active hypohalite which remains effective for an extended period of time to reliably disinfect hard surfaces such as countertops, toilet seats, door knobs and the like commonly found in the home, hospital, food service and other industries.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified systems or process parameters as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only, and is not intended to limit the scope of the invention in any manner.
[0014] All publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference.
[0015] It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a “surfactant” includes two or more such surfactants.
[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although a number of methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.
[0017] The following examples illustrate disinfecting articles and compositions of the described invention. The exemplified compositions and articles are illustrative only and do not limit the scope of the invention. Unless otherwise specified, the proportions in the examples and elsewhere in the specification are by weight percent of the total liquid composition, and loading ratios of the example compositions are by unit weight of composition per unit weight of the absorbent carrier matrix and thus expressed as a unit-less weight/weight ratio.
[0018] As used herein, the term “disinfect” shall mean the elimination of many or all pathogenic microorganisms on the surface with the exception of bacterial endospores. As used herein, the term “sanitize” shall mean the reduction of contaminants on the device surface to levels considered safe according to public health ordinance, or that reduces the bacterial population by significant numbers where public health requirements have not been established. And at least 99% reduction in bacterial population within a 24 hour time period is deemed “significant.” As used herein, the term “sterilize” shall mean the complete elimination or destruction of all forms of microbial life.
[0019] The present invention relates to a disinfecting article, housing system and disinfecting composition for cleaning and disinfecting surfaces, in which the disinfecting article comprises an aqueous hypohalite releasing composition adsorbed onto an absorbent carrier material. The disinfecting articles comprise an aqueous hypohalite releasing composition and an absorbent carrier comprising a substrate. The present invention also relates to a housing system for storing and dispensing a single or multiple number of disinfectant substrates.
[heading-0020] Absorbent Carrier
[0021] Suitable absorbent carriers may be provided by a variety of sources, including woven and non-woven webs, fabrics, foams, sponges and similar material constructs capable of absorbing the liquid disinfectant composition of the present invention. In one embodiment, the absorbent carriers have a series of apertures, which improve substrate stability, because apertures can decrease the overall surface area by up to 20%. Generally, the absorbent carrier is preferred to be in sheet form. Preferably, the cross-sectional thickness dimension of the absorbent carrier sheet is proportionally smaller than either its approximate width or length dimension in order to provide at least one surface whose surface area is sized appropriately with respect to the intended surface to be treated with the disinfectant article. The absorbent carrier may be formed into individual sheets or wipes or as a continuous sheet. In continuous sheet form, it is preferred to provide means, such as partial tears or perforations across at least one dimension of the sheet, such that the continuous sheet may be subdivided prior to use to a suitable size for the particular need at hand.
[0022] The absorbent carrier may comprise a wipe or cleaning pad. The wipe or cleaning pad can be used with the hand, or as part of a cleaning implement attached to a tool or motorized tool, such as one having a handle. Examples of tools using a wipe or pad include U.S. Pat. No. 6,611,986 to Seals, WO00/71012 to Belt et al., U.S. Pat. App. 2002/0129835 to Pieroni and Foley, and WO00/27271 to Policicchio et al.
[0023] The absorbent carrier may comprise a single layer or multiple layers of one or more materials. The absorbent carrier may also comprise a combination of one or more materials and/or one or more forms of materials. The multiple layers or multiple forms of materials are bonded to each other by suitable means to prevent separation. For example, a sheet of one material may be combined with a second sheet of a second material and bonded together by suitable means. Suitable means of bonding sheets together includes, by way of example and not by way of limitation, adhesion and heat or sonic welding. A further example, a non-woven sheet of one material may be combined with a second material formed into deformable and compressible foam, and bound together by a suitable means. In this manner, all conceivable combinations of materials may be combined to provide useful articles for a variety of cleaning and disinfecting requirements.
[0024] Further, the absorbent carrier can be combined with non-absorbent materials, preferably in the form of films, sheets or blocks. Preferably, the non-absorbent materials are liquid impervious, in that they do not permit the passage of the disinfectant compositions of the present invention. In one example, the non-absorbent materials may be bonded to one side of a suitable absorbent carrier creating a layered disinfectant article. The layered disinfectant article has a liquid impervious barrier to prevent passage of the disinfectant composition from the absorbent material to the outside surface of the barrier material. Thus the liquid impervious barrier allows the user to handle the layered disinfectant article without direct contact with the disinfectant wetted side of the layered article. Another example is a thin liquid impervious plastic sheet bounded to an absorbent foam, whereby the user contacts the plastic sheet during use rather than contacting the liquid disinfectant that is absorbed into the foam and that is displaced by pressure applied while wiping the surface to be treated.
[0025] According to the present invention, the absorbent carrier may be produced by any method known in the art. For example, non-woven material substrates can be manufactured by dry forming techniques such as air laying or wet laying such as on a paper making machine. Other non-woven manufacturing techniques, such as hydroentangling, melt blown, spun bonded, needle punched and related methods may also be used. However, it is preferred that the substrate be made substantially free of binder or latex and other impurities that may degrade or interact with the disinfectant composition. Thus, many manufacturing techniques, such as air laying, are not preferred because they do not lend themselves to the formation of binder-free and latex-free absorbent carriers. Hydroentrangling manufacturing techniques using high speed water jets are generally preferred due to the high density matrices produced and the high degree of cleanliness of the resulting non-woven articles produced by this method.
[0026] Suitable absorbent carriers are generally selected from man-made and synthetic construction materials or substrates, preferably including synthetic polymers. For good cleaning, absorption, handling and loading characteristics, it is desirable that the absorbent carrier materials be in the form of fiber, webs or foams of the suitable construction materials.
[0027] Suitable forms of employing fibers include woven and non-woven structures. Suitable woven structures include, by way of example and not by way of limitation, meshes, screens, knits, fabrics and other similarly woven structures, of sufficiently high fiber count and strength to be handled by typical machinery and process equipment needed for forming, cutting and packaging the disinfectant articles, preferably when in a dry state. Suitable woven structures include those structures that are of sufficiently high fiber count and strength to be dispensed and handled during use, preferably when in a dry state, and more preferably when in a wetted state.
[0028] Suitable woven and non-woven structures are composed of fibers with both sufficient fiber sizes and fiber densities to provide some absorption capacity and enable loading of a sufficient quantity of the disinfectant solution so as to provide for effective treatment of surfaces. The standard fiber size is 1 denier or 1 D. Fibers with a larger than standard denier size are preferable because they can improve the stability of the substrates which makes them effective for a longer period of time. Most preferably, the fibers in the substrate will have about 1.5 to 6.0 denier. Denier is a weight-per-unit-length measurement of a linear material defined as the number of grams per 9000 meters. Suitable non-woven structures include those structures that are of sufficiently high fiber count and strength to be dispensed from the packaging articles, without significant deformation, tearing or ripping, and handled during use, without unraveling, abrading or tearing, preferably when in a wetted state.
[0029] The nonwoven substrate may comprise apertures. The apertures may be formed by the PUB pattern, which is described in U.S. Pat. No. 5,858,515 to Stokes et al, the entire contents of which are hereby incorporated by reference. Apertured structures also include apertured films as described in U.S. Pat. No. 6,635,799 to Osborn et al.
[heading-0030] Absorbent Carrier Substrates
[0031] Suitable substrates employed for constructing the absorbent carrier may be provided by a variety of sources, and include all suitable substrates that are hypohalite stable, in that they undergo no significant degradation. That is, suitable substrates that undergo no significant chemical or physical change in structure, properties or form, owing to contact with the disinfectant compositions employed in the present invention, even after extending contact or storage times under representative storage conditions. Preferred are suitable substrates that do not cause significant degradation of the associated or absorbed disinfecting compositions, that is, substrates that do not catalyze or significantly accelerate the decomposition of the associated hypohalite compositions.
[0032] Suitable materials of construction generally include synthetic polymer substrates, such as, by way of example and not by way of limitation, polyethylene terephthalate (PET), polyester (PE), high density polyethylene (HDPE), polyvinyl chloride (PVC), chlorinated polyvinylidene chloride (CPVC), polyacrylamide (ACAM), polystyrene (PS), polypropylene (PP), polycarbonate (PC), polyaryletherketone (PAEK), poly(cyclohexylene dimethylene cyclohexanedicarboxylate) (PCCE), poly(cyclohexylene dimethylene terephthalate) (PCTA), poly(cyclohexylene dimethylene terephtalate) glycol (PCTG), polyetherimide (PEI), polyethersulfone (PES), poly(ethylene terephthalate) glycol (PETG), polyketone (PK), poly(oxymethylene); polyformaldehyde (POMF), poly(phenylene ether) (PPE), poly(phenylene sulfide) (PPS), poly(phenylene sulfone) (PPSU), syndiotactic polystyrene (syn-PS), polysulfone (PSU), polytetrafluoroethylene (PTFE), polyurethane (PUR), poly(vinylidene fluoride) (PVDF), polyamide thermoplastic elastomer (TPA), polybutylene (PB), polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), polyethylene naphthalate (PEN), polyhydroxyalkanoate (PHA), poly(methyl)methacrylate (PMMA) and polytrimethylene terephthalate (PTT).
[0033] Suitable materials of construction also include copolymers made from the following monomers: acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), ethylene-propylene (E/P), ethylene-vinyl acetate (EVAC), methyl methacrylate-acrylonitrile-butadiene-styrene (MABS), methacrylate-butadiene-styrene (MBS), melamine-formaldehyde (MF), melamine-phenol-formaldehyde (MPF), phenol-formaldehyde (PF), styrene-butadiene (SB), styrene-maleic anhydride (SMAH), copolyester thermoplastic elastomer (TPC), olefinic thermoplastic elastomer (TPO), styrenic thermoplastic elastomer (TPS), urethane thermoplastic elastomer (TPU), thermoplastic rubber vulcanisate (TPV), copolymer resins of styrene and acrylonitrile (SAN), styrene butadiene copolymer (SBC) and vinyl acetate-ethylene copolymer (VAE).
[0034] Preferably, the substrate is a blend of polypropylene and polyethylene terephthalate. The ratio may vary, but a preferred ratio is 50% polypropylene to 50% polyethylene terephthalate and a more preferred ratio is 20% polypropylene to 80% polyethylene terephthalate.
[0035] The substrate and the absorbent carrier constructed from said substrate herein is substantially free, preferably devoid, of any binders or latex materials. Substantial elimination of binders and latexes, and the like, can be accomplished by pre-washing the dry absorbent carrier in soft, distilled or de-ionized water or other solvents, or by using a substantially binder-free and latex-free process, such as hydroentangling (also known in the art as spunlace technology). More specifically, in the hydroentangling process, a fibrous web is subjected to high-velocity water jets, preferably employing de-ionized, distilled or soft water that entangle the fibers. The non-woven material may then be subjected to conventional drying and wind-up operations, as known to those skilled in the art. Since the hydroentangling process precludes the use of binders, and can be used to wash off fiber latexes, it is on of the most preferred processes for use in the manufacture of materials of construction of the present invention. Suitable materials of construction that are readily available in commerce include the SONTARA® brand of non-woven fabrics produced by Dupont. Representative materials include 100% polyester substrate materials designated SONTARA® 8001, 8005H, 8010 and 8061, and 50% polyester/50% Dacron® blends designated SONTARA® 8100 and including hydrophilically modified 100% polyester substate material designated SONTARA® 8005H. Additional examples include materials commercially available from Polymer Group Inc, including 100% spunlaced polyester and polypropylene materials designated M001, M022, M040×, CG003, CG005, CG2009, M017, N2006 and T133. Representative materials also include spunlaced 100% polyester materials, designated as 350160 and 10203-003, available from Jacob Holms Industries.
[heading-0036] Absorbency and Loading
[0037] The absorbent carrier preferably has a weight of from about 10 g/m 2 (grams per meter squared) to about 200 g/m 2 . More preferably, the absorbent carrier has a weight of at least about 15 g/m 2 and more preferably less than about 150 g/m 2 , more preferably the weight is in the range of about 20 g/m 2 to about 120 g/m 2 , and most preferably from about 25 g/m 2 to about 100 g/m 2 .
[0038] In preparing pre-wetted disinfectant articles according to the present invention, the composition is applied to at least one surface of the absorbent carrier material. The composition can be applied at any time during the manufacture of the articles. Preferably the composition is applied to the absorbent carrier after the absorbent carrier has been dried. Any variety of application methods that evenly distribute disinfecting compositions can be used. Suitable methods include, for example, spraying, dipping, or rolling, whereby the composition is forced through tubes in contact with the absorbent carrier whilst the absorbent carrier passes across the tube. Combinations of these application techniques may also be used, for example, spraying the composition on a rotating surface, such as calender roll, which then transfers the composition to the surface of the absorbent carrier. The composition can be applied either to one surface of the absorbent carrier or both surfaces, and preferably both surfaces.
[0039] The composition can also be applied uniformly or non-uniformly to the surfaces of the absorbent carrier. By non-uniform it is meant that, for example, the amount or pattern of distribution of the composition can vary over the surface of the absorbent carrier. That is, some of the surface of the absorbent carrier can have greater or lesser amounts of disinfectant composition, including portions of the surface to which no composition has been applied. Preferably, however, the composition is uniformly applied to the surfaces of the absorbent carrier or to the absorbent surface of the disinfectant article that comprises multiple layers or multiple materials of construction.
[0040] Preferably, the composition can be applied to the absorbent carrier at any point after it has been dried. For example, the composition can be applied to the absorbent carrier prior to or after calendaring, and prior to being wound up onto a parent roll. Typically, the application will be carried out on an absorbent carrier unwound from a roll having a width equal to a substantial number of wipes it is intended to produce.
[0041] When the absorbent carrier substrate is produced with a bonded liquid impervious layer forming an essentially impervious barrier to one side of the disinfectant article, it is then preferred that application of the disinfectant composition is made to the absorbent side of the article.
[0042] Alternatively, the disinfectant composition can also be applied at a later stage in the processing of the disinfectant articles, such as being applied to the substantially dry absorbent carrier after it has been placed into the respective storage pouch, container, canister or other packaging means, but prior to sealing or closure of said packaging means. In this alternative application means, the disinfectant solution is preferably applied by spraying, dripping or nozzle injection of a metered aliquot of the liquid disinfectant composition directly onto the absorbent material within each open package at a convenient processing stage.
[0043] The disinfecting composition is typically applied in an amount of from about 1 gram to about 10 gram per gram of absorbent carrier, preferably from about 1.5 gram to about 8.5 gram per gram of absorbent carrier, most preferably from about 2 gram to about 5 gram per gram of dry absorbent carrier. The weight ratio of the disinfecting composition to the absorbent carrier is referred to as the loading ratio and is expressed as a unit-less weight/weight ratio. It is preferred for stability reasons that the loading ratio is greater than 3.0 because this improves the stability of the disinfecting article.
[0044] Those skilled in the art will recognize that the exact amount of aqueous composition applied to the absorbent carrier will depend on the basis weight of the absorbent carrier and on the end use of the product. In one preferred embodiment, a relatively low basis weight absorbent carrier, from about 20 g/m 2 to about 80 g/m 2 , is used in the making of a pre-moistened cleaning and disinfectant wipe suitable for cleaning lightly soiled counters, stove tops, cabinetry, walls, sinks and the like. For such end uses, the dry absorbent carrier is loaded with an aqueous composition of the invention at a factor of from about 2 grams to about 10 grams per gram of dry absorbent carrier. In another preferred embodiment, a higher basis weight absorbent carrier, from about 40 g/m 2 to about 200 g/m 2 is used in the making of the pre-moistened disinfectant wipe suitable for cleaning heavily soiled or larger area surfaces, including floors, walls and the like. In such instances, the wipe may further be sold with, or designed to work with, a hand held implement comprising a handle and designed for wiping and cleaning. Examples of such implements are commercially available under the trade names Ready-Mop®, a product of The Clorox Company, and Swiffer®, a product of the Procter and Gamble Company. For such end uses, the dry absorbent carrier is loaded with an aqueous composition of the invention at a factor of from about 2 grams to about 8 grams per gram of dry absorbent carrier.
[heading-0045] Disinfectant Actives
[0046] Suitable hypohalite compounds may be provided by a variety of sources, including bleaches that lead to the formation of positive halide ions and/or hypohalite ions, as well as bleaches that are organic based sources of halides, such as chloroisocyanurates, haloamines, haloimines, haloimides and haloamides, or mixtures thereof. These bleaches also produce hypohalite-bleaching species in situ. Preferred hypohalite bleaches for use herein include the alkali metal and alkaline earth metal hypochlorites, hypobromites, hypoiodites, chlorinated trisodium phosphate dodecahydrates, potassium and sodium dichloroisocyanurates, potassium and sodium trichlorocyanurates, N-chloroimides, N-chloroamides, N-chlorosulfamide, N-chloroamines, chlorohydantoins, such as dichlorodimethyl hydantoin and chlorobromo dimethylhydantoin, or mixtures thereof.
[0047] In a preferred embodiment wherein the compositions herein are liquid, said hypohalite bleach is an alkali metal and/or alkaline earth metal hypochlorite, or mixtures thereof. More preferably, for liquid compositions said hypohalite bleach is an alkali metal and/or alkaline earth metal hypochlorite selected from the group consisting of sodium hypochlorite, potassium hypochlorite, magnesium hypochlorite, lithium hypochlorite and calcium hypochlorite, and mixtures thereof. Even more preferably, for liquid compositions said hypohalite bleach is sodium hypochlorite.
[0048] The halogen bleach is preferably present in an amount from above zero (0 ppm) to about 15 weight percent (150,000 ppm) of the composition, and more preferably, from about 0.001 weight percent (10 ppm) to about 10 weight percent (100,000 ppm) of the composition, and most preferably from about 0.01 (100 ppm) to about 1 weight percent (10,000 ppm) of the composition. A particularly preferred bleach in this invention is sodium hypochlorite, having the chemical formula NaOCl, present in an amount ranging from about 0.001 (10 ppm) to about 15 weight percent (150,000 ppm) of the composition, more preferably from about 0.005 (50 ppm) to about 10 weight percent (100,000 ppm), and most preferably from about 0.01 (100 ppm) to about 1 weight percent of the composition.
[heading-0049] Electrolyte/Buffer
[0050] The electrolyte/buffer component of the cleaning and disinfecting composition promotes a favorable environment of pH and ionic strength in which the hypohalite releasing disinfectant is stabilized against accelerated decomposition and loss of disinfectant efficacy. An electrolyte functions to provide a source of ions (generally anions) in aqueous solution. The electrolyte thus provides a charged medium in which the optional surfactant and/or optional thickeners can associate to provide thickening, or other favorable rheological properties such as shear thinning and/or viscoelastic properties. These properties provide for thickened compositions that may be readily formulated, mixed and handled by commercial processing equipment and effectively transferred by commercial pumping and dosing equipment for convenient loading onto the absorbent carrier. Suitably thickened and rheologically enhanced disinfecting compositions provide the additional benefit of higher loading capabilities onto their respective absorbent carriers, reduced dripping and evaporation during storage and use. Suitably thickened and rheologically enhanced disinfecting compositions also provide the additional benefit of clinging to treated surfaces, particularly uneven, sloped or vertical surfaces with greater tenacity and resistance from gravity to provide more efficient coverage, effective contact time and overall enhancement of the cleaning and disinfectant efficacy of the compositions.
[0051] A buffer principally acts to maintain a favorable pH of the associated aqueous disinfectant compositions, particularly when absorbed in intimate contact with the absorbent carrier materials employed. In the present invention, alkaline pH is favored for purposes of maintaining halogen bleach stability. Some compounds will serve as both electrolyte and buffer. These particular electrolyte/buffer compounds are generally various inorganic acids, for example, borates, polyphosphates, pyrophosphates, triphosphates, tetraphosphates, silicates, metasilicates, polysilicates, carbonates, and hydroxides; alkali metal salts of such inorganic acids; and mixtures of same. Certain divalent salts, e.g., alkaline earth salts of phosphates, carbonates, hydroxides, etc., can function singly as buffers. If such a divalent salt compound is used, it is combined with at least one of the above-mentioned electrolyte/buffer compounds to provide the appropriate pH adjustment. It may also be suitable to use materials such as aluminosilicates (zeolites), borates, aluminates and bleach-stable organic materials, such as the lower C1-C10 alkyl dicarboxylic acids including gluconates, succinates, and maleates, as buffers. If necessary, sodium chloride or sodium sulfate can be used as electrolytes, but not buffers, to maintain the ionic strength necessary for the desired rheology, if optional surfactants and/or thickeners are employed.
[0052] An especially preferred electrolyte/buffer compound is an alkali metal silicate, which is employed in combination with an alkali metal hydroxide to provide effective pH control and can also function as a metal ion sequestrant. The preferred silicate is sodium silicate, which has the empirical formula NaO:SiO 2 . The ratio of sodium oxide: silicon dioxide is about 1:4 to 1:1, more preferably about 1:2. Silicates are available from numerous sources, such as the PQ Corporation. The electrolyte/buffer compounds function to keep the pH range of the inventive disinfecting article and composition preferably above 9.0, more preferably at between about 9.5 to about 13.0, and most preferably at between about 10 and 12.
[0053] The pH level of the disinfecting article was measured by squeezing out the liquid from the absorbent carrier because this takes into account any influence the absorbent carrier material has on the cleaning composition. The initial pH of the cleaning composition with no contact with an absorbent carrier was measured separately for its independent stability and for comparison purposes. It is preferred that the initial pH of the composition is between about 10 and 13, and more preferably between 11.8 and 12.5. The amount of electrolyte/buffer can vary from about 0.01 to about 10 weight percent of the composition, more preferably from about 0.05 to about 5 weight percent of the composition, and most preferably from about 0.05 to about 1.0 weight percent of the composition.
[heading-0054] Water
[0055] It should be noted that the main ingredient in the inventive compositions is water, preferably softened, distilled or deionized water. Water provides the continuous liquid phase into which the other ingredients are added to be dissolved/dispersed. The amount of water present generally exceeds 90% and, indeed, can be as high as 99.9%, although generally, it is present in a quantity sufficient (q.s.) to take up the remainder of the specially formulated disinfectant compositions of the present invention.
[heading-0056] Surfactant
[0057] Optionally, a surfactant suitable for use in this invention is selected from anionic, non-ionic, amphoteric, zwitterionic surfactants and mixtures thereof. It is especially preferred to use a combination of anionic and bleach-stable, non-ionic surfactants. The anionic surfactant is selected from bleach-stable surfactants such as alkali metal alkyl sulfates, secondary alkane sulfonates (also referred to as paraffin sulfonates), alkyl diphenyl ether disulfonates, fatty acid soaps, and mixtures thereof. Such an anionic surfactant will preferably have alkyl groups averaging about 8 to about 20 carbon atoms. In practice, the use of any other anionic surfactant, which does not degrade chemically when in contact with a hypohalite bleaching species, is considered suitable for use in this invention.
[0058] An example of a particularly preferred secondary alkane sulfonate is HOSTAPUR SAS, manufactured by Farbwerke Hoechst A. G., Frankfurt, West Germany. Examples of typical alkali metal salts of alkyl benzene sulfonic acids are those manufactured by Pilot Chemical Company sold under the trademark CALSOFT. An example of a typical alkali metal alkyl sulfate is CONCO SULFATE WR, sold by Continental Chemical Company, which has an alkyl group of about 16 carbon atoms. When the electrolyte used is an alkali metal silicate, it is most preferable to include a soluble alkali metal soap of a fatty acid, such as a hexyl to tetradecyl fatty acid soaps. Especially preferred are sodium and potassium soaps of lauric and myristic acid. When used as a component of the inventive cleaning composition, the alkali metal soap of a fatty acid is present in an amount from above zero to about 10 weight percent of the composition.
[0059] Examples of preferred bleach-stable, non-ionic surfactants are amine oxides, especially trialkyl amine oxides, as represented in the formula expression RR′R″NO, in which R′ and R″ may be alkyls of 1 to 3 carbon atoms and are most preferably methyls, and R is an alkyl of about 10 to 20 carbon atoms. When R′ and R″ are both methyl and R is alkyl averaging about 12 carbon atoms, the structure for dimethyldodecylamine oxide, a particularly preferred amine oxide, is obtained. Representative examples of these particular types of bleach-stable, non-ionic surfactants include the dimethyldodecylamine oxides sold under the trademark AMMONYX LO by Stepan Chemical. Yet other preferred amine oxides are those sold under the trademark BARLOX by Lonza, CONCO XA sold by Continental Chemical Company, AROMAX sold by Akzo, and SCHERCAMOX, sold by Scher Brothers, Inc. These amine oxides preferably have main alkyl chain groups averaging about 10 to about 20 carbon atoms. Other types of suitable surfactants include amphoteric surfactants such as, for example, betaines, imidazolines and certain quaternary phosphonium and tertiary sulfonium compounds.
[0060] It is suitable to use one or more surfactants in the inventive compositions. In the inventive composition, total surfactant, when present, is included in an amount ranging from about 0.001 to about 20 weight percent of the composition, preferably in an amount ranging from about 0.01 to about 5 weight percent of the composition. For reduced surface residue and to decrease the tendency of the compositions to contribute to excess foaming, residual filming or streaking, and particularly for use on glossy or shiny surfaces, total surfactant, when present, is included in an amount most preferably from about 0.01 to about 1.0 weight percent of the composition.
[heading-0061] Secondary Surfactant
[0062] Optionally, an additional co-surfactant may be added to the disinfectant composition of this invention. The bleach stable anionic surfactants include alkali metal alkyl sulfates, alkylarylsulfonates, primary and secondary alkane sulfonates (also referred to as paraffin sulfonates), alkyl diphenyloxide disulfonates, and mixtures thereof. The anionic surfactants have alkyl groups preferably averaging about 8 to 20 carbon atoms. The alkyl arylsulfonic acid salts of preference are linear alkylbenzene sulfonates, known as LAS's. Typical LAS's have C8-16 alkyl groups, non-limiting examples of which include Stepan Company's Biosoft and Pilot Chemical Company's Calsoft. Still further suitable surfactants are the alkyldiphenylether disulfonates (also called alkyldiphenyloxide disulfonates), such as, by way of example only, those sold by Dow Chemical Company under the name “Dowfax,” e.g., Dowfax 3B2. Still other potentially suitable anionic surfactants include alkali metal alkyl sulfates such as Conco Sulfate WR, sold by Continental Chemical Company, which has an alkyl group of about 16 carbon atoms; and secondary alkane sulfonates such as Hostapur SAS, manufactured by Farbwerke Hoechst AG.
[heading-0063] Hydrotropes
[0064] Hydrotropes, on the other hand, are dispersants, which do not form a critical micelle concentration (CMC) in water (See Colbom, et al, U.S. Pat. No. 4,863,633, column 8, line 20 through column 10, line 22, incorporated herein by reference). These hydrotropes may interact with some of the bleach stable surfactants bearing at least one nitrogen atom to form thickened, viscoelastic formulations. However, it is notable that the thickening phenomenon is not critical to the enhanced brightness retention of the invention. The hydrotropes are preferably selected from short chain alkylarylsulfonates, salts of benzoic acid, benzoic acid derivatives (such as chlorobenzoic acid), and mixtures thereof. As used herein, aryl includes, without limitation, at least benzene, naphthalene, xylene, cumene and similar aromatic nuclei. These aryl groups can be substituted with one or more substituents known to those skilled in the art, e.g., halo (chloro, bromo, iodo, fluoro), nitro, or C1-4 alkyl or alkoxy. Most preferred is sodium xylene sulfonate (such as Stepanate SXS, available from Stepan Company).
[heading-0065] Sequestrant/Chelant
[0066] Optionally, sequestering agents are suitable for use in the inventive disinfectant articles. Sequestering agents are selected from the group consisting of metal chelators, metal sequestrants and ion exchange materials known in the art. Preferably, metal chelators and metal sequestrants are selected from the group consisting of the alkali and alkaline earth salts of the phosphates, phosphonates, borates, silicates, polyfunctionally-substituted aromatic chelating agents, ethylenediamine tetra-acetate (EDTA) and ethylenediamine —N,N′-disuccinic acids, or mixtures thereof. Preferred sequestering agents are the silicates and ethylenediamine tetra-acetate.
[0067] Polyfunctionally-substituted aromatic chelating agents may also be useful in the bleaching compositions herein. See U.S. Pat. No. 3,812,044, issued May 21, 1974, to Connor et al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,-5-disulfobenzene. A preferred biodegradable chelating agent for use herein is ethylene diamine N,N′-disuccinic acid, or alkali metal, or alkaline earth, ammonium or substituted ammonium salts thereof or mixtures thereof.
[0068] Sequestering agents are also selected from the group consisting of polyacrylic acid, a polyacrylic acid derivative, or a copolymer of acrylic acid or methacrylic acid and a comonomer, which is maleic acid or maleic anhydride. By “polyacrylic acid derivative” is meant copolymers derived from acrylic monomers and non-acrylic monomers. Acrylic monomers generally refer to esters of acrylic acid and methacrylic acid as well as those of other α-substituted acrylic acids (e.g., α-chloroacrylic, and α-ethylacrylic acids). Preferred acrylic monomers include, for example, acrylic acid and methacrylic acid. Suitable non-acrylic acid monomers include, for example, ethylene and propylene.
[0069] Other suitable polycarboxylate sequestering agents include, for example and no by way of limitation, polymethacrylate (DAXAD 30,35,37™ from W. R. Grace & Co. and ALCOSPERSE 124™ from ALCO Chemical), acrylic acid/methacrylic acid (SOKOLAN CP 135™ from BASF Corp.), an oxidized ethylene/acrylic acid, carboxylated vinyl acetate (DARATAK 78L™ from W. R. Grace), vinyl acetate/crotonic acid (LUVISET CA66™ from BASF Corp.), vinyl acetate/vinyl propionate/crontonic (LUVISET CAP™ by BASF Corp.), vinyl acetate/vinyl neodecanoate/crontonic acid (Resyn 28-2930(by National Starch Co.), vinyl acetate/methacryloxy 1-benzophenone/crontonic acid (RESYN 28-3307™ from National Starch Co.), acrylic acid/methylethyl acrylate, ethylene/maleic acid (EMATM from Monsanto Co.), poly(isobutylene/maleic acid) (DAXAD 31™ from W. R. Grace & Co.), maleic acid/vinyl acetate (LYTRON X 886™ from Monsanto Co.), poly(methyl vinyl ether/maleic acid) (SOKALAN CP2™ from BASF Corp.), poly(styrene/maleic anhydride) and mixtures thereof. Preferably the average molecular weight of the polycarboxylate polymer sequestering agent is between about 500 to about 500,000 daltons and preferably ranges from about 1,000 to about 200,000 daltons, more preferably from about 3,000 to about 70,000 daltons.
[0070] Most preferably the sequestering agent is selected from polyacrylic acid, a polyacrylic acid derivative, a copolymer of acrylic acid or methacrylic acid and a comonomer, which is preferably maleic acid or maleic anhydride and mixtures thereof.
[heading-0071] Other Adjuncts
[0072] The disinfectant composition of the present invention may optionally be formulated to include further adjuncts, for example, thickening agents, rheology modifiers, fragrances, coloring agents, pigments (e.g., ultramarine blue), bleach-stable dyes (e.g., anthraquinone dyes), whiteners, including the optional surfactants, solvents, chelating agents and builders, which enhance performance, stability or aesthetic appeal of the composition. Generally, such adjuncts may be added in relatively low amounts, e.g., each from about 0.001 to about 5.0 weight percent of the composition. By way of example, a fragrance such as a fragrance commercially available from International Flavors and Fragrance, Inc., may be included in the inventive composition in an amount from about 0.01 to about 0.5 weight percent of the composition. Dyes and pigments may be included in small amounts in the composition of the present invention. Examples of widely used, suitable pigments include ultramarine blue (UMB) and copper phthalocyanines.
[0073] Solvents may also be added to the inventive compositions to enhance cleaning and/or disinfectant efficacy of the compositions. For example, certain less water soluble or dispersible organic solvents, some of which are advantageously stable in the presence of hypochlorite bleach, may be included. These bleach-stable solvents include those commonly used as constituents of proprietary fragrance blends, such as terpenes and essential oils, and their respective derivatives.
[0074] The terpene derivatives suitable for the present invention include terpene hydrocarbons with a functional group. Effective terpenes with a functional group include, but are not limited to, alcohols, ethers, esters, aldehydes and ketones. Representative examples of each of the above-mentioned terpenes with a functional group include, but are not limited to, the following: (1) terpene alcohols, including, for example, verbenol, transpinocarveol, cis-2-pinanol, nopol, iso-borneol, carbeol, piperitol, thymol, alpha-terpineol, terpinen-4-ol, menthol, 1,8-terpin, dihydroterpineol, nerol, geraniol, linalool, citronellol, hydroxycitronellol, 3,7-dimethyl octanol, dihydromyrcenol, beta-terpineol, tetrahydro-alloocimenol and perillalcohol; (2) terpene ethers and esters, including, for example, 1,8-cineole, 1,4-cineole, iso-bomyl methylether, rose pyran, alpha-terpinyl methyl ether, menthofuran, trans-anethole, methyl chavicol, allocimene diepoxide, limonene mono-epoxide, iso-bornyl acetate, nopyl acetate, alpha-terpinyl acetate, linalyl acetate, geranyl acetate, citronellyl acetate, dihydro-terpinyl acetate and neryl acetate; and (3) terpene aldehydes and ketones, including, for example, myrtenal, campholenic aldehyde, perillaldehyde, citronellal, citral, hydroxy citronellal, camphor, verbenone, carvenone, dihydrocarvone, carvone, piperitone, menthone, geranyl acetone, pseudo-ionone, alpha-ionone, beta-ionone, iso-pseudo-methyl ionone, normal-pseudo-methyl ionone, iso-methyl ionone and normal-methyl ionone. Terpene hydrocarbons with functional groups which appear suitable for use in the present invention are discussed in substantially greater detail by Simonsen and Ross, The Terpenes, Volumes I-V, Cambridge University Press, 2 nd Ed., 1947, which is incorporated herein in entirety by this reference. See also, commonly assigned U.S. Pat. No. 5, 279,758, issued to Choy on Jan. 18, 1994, which is incorporated herein in entirety by this reference.
[heading-0075] Housing Systems and Packaging Materials
[0076] Suitable packaging materials may be provided by a variety of sources, and include all suitable materials that are hypohalite stable, in that they undergo no significant degradation. That is, the packaging materials undergo no significant chemical or physical change in structure, properties or form, owing to contact with the hypohalite compositions employed in the present invention. Suitable packaging materials include those materials common to the art.
[0077] Housing systems include both individually packaged disinfectant wipes and bulk packaged one or more disinfectant wipes or other suitable disinfecting articles. The housing system preferably comprises a sealable container, which is substantially impervious to both liquid and gas. The term “container”, refers to, but is not limited to, packets containing one or more individual disinfectant wipes and bulk dispensers, such as canisters, tubs and jars, which dispense one disinfectant wipe at a time, and further feature suitable means to reseal the bulk dispenser between uses to preserve the integrity of the disinfecting articles. One example is a cylindrical canister dispenser that hosts a roll of individual wipes, separated by perforations to permit the tearing off of individual wipes for use. Such dispenser is conveniently gripped by the user and held in position while the user removes a wipe. Preferred are dispensers featuring a resealable dispensing cap and orifice (See, e.g., Chong, U.S. Pat. No. 6,554,156, of common assignment and incorporated herein by reference thereto) that dispenses individual wipes from a roll and retains the next wipe in a ready-to-dispense position, yet allows sealing of the dispensing cap to close the container against the environment when not in use. A further example, within the scope of the present invention, is to package individual wipes in a non-linked manner, in a dispenser permitting their removal one at a time, as is the case with many wipe/dispenser combinations known in the art.
[0078] Experimental Results
TABLE 1 Stability Testing Using pH Levels and Expected Consumer Behavior Number pH level for wipes pH level for wipes pH level for wipes of Days stored at 70° F. stored at 100° F. stored at 120° F. 0 11.8 11.8 11.8 4 11.75 11.73 10.74 5 11.15 10.57 10.17 6 11.56 10.96 10.34 11 11.64 10.95 10.11 13 11.59 10.83 10.10 18 10.68 10.67 9.80 20 10.06 10.43 9.56 22 10.77 10.35 9.66
[0079] The disinfectant wipes for this stability test contained about 0.6% NaOCl, 0.015% NaOH, 0.03% fragrance, 0.55% Ammonyx DO, 0.15% SXS, and 0.5% Silicate N on a PET substrate. During the course of the stability test, the results of which are in table 1, 9 wipes were pulled and tested from each sealable cylindrical container. The containers hold a roll of wipes and have an orifice for dispensing wipes individually. The testing of the three containers was performed over the period of 22 days where each canister was stored at controlled temperatures of 70° F., 100° F. and 120° F. These temperatures were intended to replicate different types of consumer use and test long-term stability. The testing was performed by squeezing the liquid from the disinfecting wipes to measure the pH. The pH levels of the 70° F. articles were overall higher than those of the 100° F. articles, which in turn had higher pH levels than the 120° F. article. Each of the samples showed a substantial drop in pH levels around the 4th day and then pH levels increased a little before they began to decrease more steadily over time. Acceleration calculations done with this data indicated that the stability and effectiveness of the wipes could be maintained for about a year at 70° F.
TABLE 2 Effect of Buffer Type on Stability of PET Wipe Number of Days 0 14 21 28 35 % NaOCl for NaOH only 0.59 0 0 0 0 % NaOCl for 0.5% Silicate N, 0.59 0.49 0.46 0.38 0.24 pH = 11.59 % NaOCl for 0.5% Silicate N, 0.63 0.45 0.41 0.35 0.21 pH = 12.44 % NaOCl for 0.5% Silicate N, 0.63 0.47 0.31 0.21 0.06 pH = 12.89 % NaOCl for 0.015% Silicate N 0.59 0.58 0.58 0.51 0.005 +0.005% Na 3 PO 4 % NaOCl for 0.5% Na 3 PO 4 , 0.66 0.53 0.36 0.11 0 pH = 12.45 % NaOCl for 0.5% Borate, 0.64 0 0 0 0 pH = 12.41 % NaOCl for 0.5% Na 2 CO 3 , 0.63 0.45 0 0 0 pH = 12.44
[0080] To perform a stability test on the effect of buffer type, the results of which are shown in Table 2, each buffer sample was put on a PET substrate that contained about 0.6% NaOCl, 0.015% NaOH, 0.03% fragrance, 0.55% Ammonyx DO, 0.15% SXS, and 0.5% Silicate N. The test was performed over the period of 28 days in a 120° F. controlled temperature room. The testing was performed by squeezing the liquid from the disinfecting wipes to measure the remaining percentage of NaOCl. The disinfecting articles were evaluated for activity using oxidation/reduction titration methods known to those in the art to determine the percentage of remaining sodium hypochlorite. The results indicate the NaOH only and 0.5% Borate samples were the least stable and after 14 days because neither one had a significant amount of sodium hypochlorite remaining. The carbonate and phosphate samples demonstrated good stability until approximately the 14′ day and then the level of NaOCl began to decrease dramatically. Unlike the other buffer samples, the 0.5% Silicate N samples showed a steady decline in the percentage of NaOCl over time, but the overall percentage of NaOCl remained substantially higher than the other buffer samples at the end of the 28-day period, which correlates to a higher level of stability and efficacy for the disinfecting articles.
TABLE 3 The Effect of the Loading Ratio on PET Wipe Stability Using pH Number of Days 0 7 14 21 28 % NaOCl for 0.69 0.66 0.52 0.37 0.17 3.0 Loading Ratio % NaOCl for 0.69 0.66 0.53 0.41 0.17 3.5 Loading Ratio % NaOCl for 0.69 0.66 0.56 0.46 0.26 4.5 Loading Ratio Sample without 0.69 0.68 0.65 0.63 0.61 PET substrate
[0081] As shown in Table 3, the disinfectant articles for the loading ratio test contained about 0.69% NaOCl, 0.015% NaOH, 0.03% fragrance, 0.55% Ammonyx DO, 0.15% SXS, and 0.5% Silicate N on a PET substrate. The loading test was performed at a controlled temperature of 120° F. The test samples were obtained by squeezing the liquid from the disinfecting wipes to measure the remaining percentage of NaOCl. The disinfecting articles were evaluated for activity using oxidation/reduction titration methods known to those in the art to determine the percentage of remaining sodium hypochlorite. The table shows that a higher loading ratio improves the stability of the disinfecting substrate slightly over the course of 28 days. This increase in 28-day stability correlates to a much more dramatic increase in stability over the course of an entire year.
TABLE 4 Fiber's Denier Size Effect on Stability Number of Days 0 7 14 21 28 pH level of 100% PET 1D fibers 11.90 11.64 11.50 11.43 11.38 DuPont 8090 pH level of 100% PP 1.5D fibers 11.90 11.65 11.52 11.48 11.42 DuPont T133 pH level of 100% PPWA a 4D fibers 11.90 11.71 11.69 11.66 11.61 from FiberVisions PH level of 100% PPWA 6D fibers 11.90 11.73 11.71 11.65 11.62 from FiberVisions a hydrophilically modified PP with hypochlorite stable wetting agent
[0082] As shown in Table 4, the disinfectant articles for the denier size stability test contained about 0.6% NaOCl, 0.015% NaOH, 0.03% fragrance, 0.55% Ammonyx 5 DO, 0.15% SXS, and 0.5% Silicate N. The testing was performed at a controlled temperature of 100° F. over the course of 28 days. The larger denier PP fibers, 1.5 denier or higher, are more effective at maintaining pH levels and have better stability than the standard denier size fibers.
TABLE 5 Substrate Type Effect on Stability Number of Days 0 7 14 21 28 pH level of 100% PET 8090 11.90 11.11 10.81 10.44 10.05 N Silicate 0.5% pH level of 100% PP T133 11.90 11.77 11.42 11.27 10.84 N Silicate 0.5% pH level of 80% PP/20% 12.50 12.22 12.04 11.69 11.41 PET 89D Metasilicate 0.5% pH level of 50% PP/50% 12.50 12.09 11.77 11.34 11.02 PET 89C Metasilicate 0.5%
[0083] The disinfectant wipes for substrate testing, the results of which are shown in Table 5, contained about 0.6% NaOCl, 0.015% NaOH, 0.03% fragrance, 0.55% Ammonyx DO and 0.15% SXS. The testing was performed in at a controlled temperature of 100° F. The data indicates that the 100% PP wipe was able to maintain a higher pH level than the 100% PET wipe over the span of 28 days. Since PP is less absorbent than PET, blends of PP and PET were tested to see if the substrate absorbency could be increased while maintaining high pH levels. The results indicate that blends of PP and PET are significantly more stable at higher pH levels than either PP or PET alone. The 80% PP and 20% PET wipe showed the best results and was noticeably more stable than the 50% PP and 50% PET wipe.
[0084] The testing methods described are not intended to limit in any manner the scope or equivalents to which the invention is entitled, the invention is further characterized by the claims, which follow.
|
The present invention relates to a disinfecting article, a sealable housing system for disinfecting articles, and a disinfecting composition comprising a hypohalite composition and a surfactant, for cleaning and disinfecting surfaces, with improved stability and extended efficacy for cleaning and disinfecting surfaces with residues such as foods, dirt, microorganisms and many other common contaminates. The disinfecting article is preferably a wipe that is comprised of high denier fibers and stored in a sealable housing system to ensure the stability of the substrate in the hypohalite releasing solution.
| 0
|
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to methods and coatings for alleviating reactions between components, such as the components of support structures in turbine sections of gas turbines. More particularly, this invention relates to methods and coatings for inhibiting diffusion of silicon from a silicon-containing component into a metallic component supporting the silicon-containing component.
[0002] Silicon-containing (Si-containing) monolithic ceramics and ceramic matrix composites (CMC's) are currently under development for high temperature components, such as combustors, shrouds, nozzles (vanes), and other hot stage components of industrial and aircraft gas turbines. Materials of particular interest include continuous fiber ceramic composite (CFCC) materials, as well as monolithic silicon nitride (Si 3 N 4 ) and silicon carbide (SiC) materials. A notable example of a CFCC has been developed by the General Electric Company under the name HiPerComp®, and contains continuous silicon carbide fibers in a matrix of silicon carbide and silicon. In the applications under consideration, backside superalloy support structures will typically be required to support monolithic ceramic and CMC components. The resulting ceramic-superalloy interface must be capable of tolerating temperatures of up to 1100° C. for long periods of time while physically maintaining intimate contact between the ceramic component and its superalloy support structure to avoid stressed-induced vibration.
[0003] Above about 1400° F. (about 760° C.), chemical compatibility of superalloys materials and Si-containing ceramics, in particular SiC fiber-reinforced SiC matrix composites, becomes an issue. Degradation has been observed in the physical properties of many nickel-base and cobalt-base superalloys when contacting Si-containing ceramics at high temperatures (e.g., about 900 to 1200° C.) as a result of silicon (and, to a lesser extent, carbon) diffusion across the ceramic-superalloy interface. In the well-known Hastelloy X superalloy, contact with a Si-containing ceramic for 500 hours at a temperature of 900° C. has been shown to result in silicon diffusion and the formation of brittle suicides to a depth of about twenty micrometers beneath the superalloy surface. Diffusion and silicide formation have been observed to increase to a depth of more than 40 mils (about one millimeter) if the same alloy is exposed for 120 hours to a temperature of about 1150° C. A number of complex reactions are potentially responsible for the precipitation of brittle silicide (and carbide) phases within a superalloy. In any event, such phases can act as sites for the initiation and propagation of cracks through the superalloy.
[0004] In view of the above, it would be desirable to prevent or at least inhibit the diffusion of silicon from a Si-containing ceramic component into a superalloy component that contacts the ceramic component, and inhibit reactions between the Si-containing ceramic and superalloy.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention provides a method for inhibiting diffusion of silicon into a metallic support structure from a component formed of a silicon-containing material, and an assembly formed thereby. The invention is particularly directed to a component-support structure assembly that will be subjected to very high temperatures over extended periods, as is the case with various assemblies of gas turbines.
[0006] In the assembly of this invention, the component is supported and contacted by the support structure so as to define a contact interface therebetween. A barrier coating is present on the component and/or the support structure, so as to be disposed at the contact interface to prevent direct physical contact between the Si-containing component and a metallic substrate of the support structure. The barrier coating consists essentially of an oxide that is more thermally stable than silica, and inhibits diffusion of silicon from the Si-containing material into the metallic substrate.
[0007] In the method of this invention, the barrier coating is deposited on either or both of the component and support structure. The component is then attached to the support structure so that the component is supported and contacted by the support structure so as to define a contact interface between the component and a metallic substrate of the support structure. As a result of assembly, the barrier coating is disposed at the contact interface to prevent direct physical contact between the Si-containing material and the metallic substrate.
[0008] A significant advantage of this invention is that the barrier coating is effective to inhibit and substantially prevent diffusion of silicon from a Si-containing material, such as a monolithic ceramic or CMC, to a superalloy substrate contacted by the Si-containing material at temperatures of up to at least 1200° C. More particularly, the barrier coating inhibits the formation within a superalloy surface region of brittle silicide phases that can serve as sites for the initiation and propagation of cracks in the superalloy. As such, the invention is beneficial for components and support structures of the type used within the turbine sections of gas turbines, such as combustors, shrouds, nozzles (vanes), and other hot stage components of industrial and aircraft gas turbines.
[0009] Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 represents a cross-sectional view of a CMC component secured to a superalloy substrate in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] FIG. 1 represents a sectional view of an assembly 10 that includes a ceramic component 12 mounted to a support structure 14 with a pin 16 . The component 12 may be a component of a gas turbine engine, such as a combustor liner or a shroud surrounding the outer blade tips within the turbine section of a gas turbine. Ceramic materials of particular interest are those containing silicon, such as Si-containing monolithic ceramics and CMC's containing silicon carbide as the reinforcement and/or matrix material, a specific example of the latter being the HiPerComp® CFCC developed by the General Electric Company and made up of continuous silicon carbide fibers in a matrix of silicon carbide and silicon. However, other silicon-containing materials are also within the scope of the invention, including monolithic ceramics such as silicon nitride and suicides (intermetallics) such as niobium silicide and molybdenum silicide. In the preferred embodiment, the support structure 14 is formed of a high-temperature superalloy, particularly a nickel-base or cobalt-base superalloy containing chromium. While FIG. 1 shows the ceramic component 12 and superalloy support structure 14 as being secured together with the pin 16 , the pin 16 or other types of fasteners would not be a necessary component of ceramic-superalloy assemblies within the scope of this invention.
[0012] When heated to temperatures of about 1400° F. (about 760° C.) or more, free silicon and carbon within the component 12 tend to migrate from the component 12 and, if permitted, diffuse into the superalloy of the support structure 14 , leading to a number of potential reactions that form brittle suicides and carbides in the surface region of the support structure 14 . For example, penetration of silicon into nickel-base superalloys containing chromium can result in the formation of stable suicides such as NiSi, Ni 2 Si, and Cr 3 Si, which form numerous eutectic phases that may be molten at temperatures lower than those to which combustor and turbine components are subjected in their operating environments. In the reaction zone, marked increases in microhardness have been observed, resulting in subsurface embrittlement of the alloy. Even small amounts of silicon impurity in many superalloys can cause the precipitation of brittle Laves phases. Diffusion of carbon into a superalloy substrate can also be detrimental, resulting in the formation of carbides and leading to excess levels of carbon in the alloy that may cause the precipitation of brittle sigma phases. Consequently, the diffusion of silicon and carbon from the ceramic component 12 into the superalloy support structure 14 , and the subsequent reaction of the diffused silicon and carbon within the structure 14 , can present serious problems.
[0013] To prevent the above-noted detrimental reactions, the present invention makes use of a barrier layer 18 capable of inhibiting the diffusion of free silicon (and, to some degree, carbon) from Si-containing materials. Suitable materials for the barrier layer 18 are those that are at least as thermally stable as the oxide(s) that may be present on the component 12 or structure 14 and therefore contacted by the barrier layer 18 . If deposited on the component 12 , an example of a suitable material for the barrier layer 18 is mullite (3Al 2 O 3 .2SiO 2 ), which is more thermally stable than the silica inherently present on the surface of the Si-containing material of the component 12 . Other suitable materials for the barrier layer 18 include rare earth silicates such as Y 2 Si 2 O 7 , Y 2 SiO 5 , Lu 2 Si 2 O 7 and Lu 2 SiO 5 , alkaline earth silicates such as calcium silicate and barium silicate, and alkaline earth aluminosilicates such as barium-strontium aluminosilicate. A barrier layer 18 deposited directly on the component 12 may have a thickness of about 25 to about 150 micrometers. If deposited on the superalloy support structure 14 , the barrier layer 18 may be alumina, stabilized zirconia, yttria, mullite, titania, or chromia, each of which is also more thermally stable than silica. If the barrier layer 18 is to be deposited on the support structure 14 , an alumina-forming metallic coating 20 such as an MCrAlY (where M is iron, cobalt, and/or nickel, and X is yttrium or another rare earth or reactive element) is preferably first deposited to a thickness of about 25 to about 250 micrometers on the support structure 14 to minimize the thermal expansion mismatch between the oxide barrier layer 18 and the superalloy of the support structure 14 . In this case, a preferred material for the barrier layer 18 is yttria-stabilized zirconia deposited to a thickness of about 25 to about 250 micrometers.
[0014] Leading up to the present invention, studies were undertaken that suggested a coating of alumina or yttria would be capable of serving as a barrier to the diffusion of silicon from a Si-containing ceramic into a superalloy contacting the ceramic. While their effectiveness as a diffusion barrier was noted, the coatings were found to not adhere well to the ceramic material during thermal cycling because of thermal mismatches, in some cases resulting in detachment and fracture of the coatings after a single thermal cycle.
[0015] In a subsequent investigation, a number of superalloy materials were evaluated with oxide coatings of different types to assess the capability of the coatings to inhibit the diffusion of silicon across Si-containing ceramic:superalloy couples subjected to temperatures in a range about 900° C. to about 1200° C. for durations of about 50 to about 1600 hours. For this investigation, coupons of the superalloy materials were formed to have approximate dimensions of 1×½×⅛ inch (about 25×13×3 mm). Surfaces of the coupons were polished using 600 grit SiC paper and then buffed to a mirror finish. Similarly-sized coupons of a Si-containing ceramic composite material containing silicon and silicon carbide formed by silicon melt infiltration were also prepared and polished. Such ceramic materials are also known as reaction-bonded silicon carbide, or Silcomp in the literature. These materials are representative of the matrix of SiC fiber-reinforced Si-SiC matrix composites made by melt infiltration (HiPerComp®). The alloy and ceramic coupons were pressed together and wrapped tightly with platinum-rhodium wire, and the resulting specimen assemblies were placed in alumina boats and heated in air at selected test temperatures. In some cases, the assemblies were heated in flowing helium to reduce the extent of oxidation resulting from the diffusion of air into the contact zone between the two coupons. The assemblies were subjected to the test temperatures for varying periods of time, after which the assemblies were sectioned and the interfacial reaction zones examined by standard metallographic techniques.
[0016] Additional specimen assemblies essentially identical to those described above were also prepared, but with the additional step of depositing an oxide coating on the superalloy coupons prior to mating of the coupons to form the specimen assemblies. The coatings were zirconia (ZrO 2 ) stabilized with about 8 weight percent yttria (Y 2 O 3 ), titania (TiO 2 ), chromia (Cr 2 O 3 ), and alumina (Al 2 O 3 ) applied to thicknesses of about 4 to 5 mils (about 100 to 125 micrometers) by low pressure plasma spraying (LPPS). Prior to depositing the oxide coatings, a bond coat of NiCrAlY alloy was deposited to a thickness of about 1 to 2 mils (about 25 to 50 micrometers) directly on the superalloy coupon surface. As previously noted, the intended purpose of the NiCrAlY bond coats was to minimize the thermal expansion mismatches between the oxide coatings and their superalloy substrates.
[0017] In those specimens not provided with an oxide coating, reaction zones were found to have formed in the superalloy coupons at the completion of the high-temperature exposure. Table 1 summarizes the superalloys and the temperatures and durations at which they were evaluated, and the approximate penetration depths of silicide precipitates, as determined visually from micrographs. In each case, sectioning and examination of the contact zones of the superalloy and ceramic coupons evidenced that silicon had diffused from the ceramic coupons into the superalloy coupons, resulting in the formation of voids in the ceramic matrix of the ceramic material and precipitates within the superalloys.
TABLE I Si Duration Temperature Penetration k Superalloy (hr) (° C.) (μm) (cm · s −1/2 ) Hastelloy X 500 900 20 1.6 × 10 −6 1622 900 35 1.4 × 10 −6 100 1000 65 1.1 × 10 −5 672 1000 250 1.6 × 10 −5 500 1100 >300 >2.2 × 10 −5 120 1150 1100 1.7 × 10 −4 Inconel 718 120 1150 875 1.3 × 10 −4 René 80 1000 1000 >140 >7.5 × 10 −6 120 1150 1350 2.1 × 10 −4 Ni—50Cr 120 1150 1200 1.8 × 10 −4 Ni—20Cr—10Ti 140 1175 ˜1250 >2.0 × 10 −4
[0018] For a diffusion-controlled process such as what occurred in this investigation, a plot of penetration depth/(time) 1/2 vs. reciprocal temperature should give a straight line, which can be used to predict approximate silicon penetration depths at intermediate temperatures. The results of the investigation appeared to follow this generalization, and indicated an apparent activation energy for the diffusion process of about 62 Kcal/mole. The observed migration of silicon into the evaluated superalloys inherently results in a loss of mechanical properties in the superalloys, such as low and high cycle fatigue life, rupture strength, and ductility. While the investigation did not indicate that the rate of silicon diffusion is a strong function of alloy composition, the extent of property degradation probably is. For example, Hastelloy X is a more ductile superalloy than, for example, René 80 and IN718, and hence the loss of properties would be expected to be correspondingly less severe in the former. Nevertheless, even with Hastelloy X, an embrittled zone having a depth of as little as about 10 mils (about 250 micrometers) would be considered unacceptable for many structural applications.
[0019] The details of the reaction at the interface between a ceramic material and a superalloy substrate appeared to depend in a complex manner on the composition of the particular superalloy. For example, the hemispherical reaction zones in the Ni-50Cr coupons were characterized by large voids, and appeared quite different from the more uniform attack and precipitation of fine suicide particles and acicular sigma phase observed in the IN718 coupons subjected to the same test exposure. In the Ni—Cr alloy, a molten silicide phase probably formed during testing, while the René 80 coupons formed a hemispherical reaction zone after only 120 hours at 1150° C. and developed a network of fine silicide particles after 1000 hours of testing. A more catastrophic reaction zone appeared to develop in the ternary alloy Ni-20Cr-10Ti after 1 40 hours at 1170° C., characterized by the development of voids and porosity within the superalloy that were probably the result of molten silicide formation.
[0020] The specimens assembled with a superalloy coupon having an oxide coating were tested under similar conditions as those described above. The specific specimen combinations included yttria-stabilized zirconia (YSZ) on IN738 (about 1004 hours at about 900° C.; about 600 hours at about 1000° C.), YSZ on Rene 80 (about 552 hours at about 1000° C.), alumina on Hastelloy X (about 672 hours at about 1000° C.), chromia on Hastelloy X (about 672 hours at about 1000° C.), titania on Hastelloy X (about 672 hours at about 1000° C.), and alumina on Hastelloy X (about 500 hours at about 1100° C.). Each of the specimens were sectioned and examined at the completion of the high temperature evaluation. Examination of the IN738 and René 80 specimens evidenced that none of these Si-containing ceramic:superalloy couples exhibited any evidence of silicon penetration through their YSZ coatings and into their superalloy substrates. Notably, the YSZ coatings were well adhered by the underlying NiCrAlY bond coat to their superalloy substrates.
[0021] The alumina, titania, and chromia coatings deposited on the Hastelloy X coupons remained intact during the high temperature tests, but disintegrated during metallographic mounting and sectioning. Nonetheless, all three oxide coating compositions proved to be effective in preventing the diffusion of silicon into their underlying superalloy substrates, as evidenced by no silicide formation beneath the coatings. EDS (energy dispersive spectrometry) element scans across the interfaces of TiO2-coated and Cr 2 O 3 -coated Hastelloy X specimens subjected to about 900° C. for about 1622 hours evidenced that silicon had not penetrated either oxide coating.
[0022] Based on the above, it was conjectured that, in addition to or instead of an oxide coating on the superalloy component of a ceramic:superalloy couple, an oxide coating deposited directly on the ceramic component could also be effective to inhibit silicon diffusion. However, limited oxides are candidates for this purpose as most have a higher thermal expansion coefficient than silicon carbide and hence would not remain adherent to a Si-containing ceramic during thermal cycling. Because its thermal expansion behavior closely matches silicon carbide, mullite (3Al 2 O 3 .2SiO 2 ; α=5.1-5.4×10 −6 /° C. between 25 and 1000° C.) was selected as a diffusion barrier coating material for a second investigation. However, other oxide materials believed to be suitable include rare earth silicates such as Y 2 Si 2 O 7 , Y 2 SiO 5 , Lu 2 Si 2 O 7 and Lu 2 SiO 5 , alkaline earth silicates such as calcium silicate and barium silicate, and alkaline earth aluminosilicates such as barium-strontium aluminosilicates. There are several oxides within these families that have expansion coefficients similar to silicon-containing ceramics, for example, stoichiometric barium-strontium aluminosilicate ((Ba 0.75 Sr 0.25 )O—Al 2 O 3 —SiO 2 ).
[0023] Mullite coatings having thicknesses of about 10 mils (about 250 micrometers) were directly applied to surfaces of additional Si-containing ceramic composite coupons by air plasma spraying. No attempt was made to polish the mullite coatings before assembling the ceramic coupons with Hastelloy X coupons obtained for testing. The efficacy of these mullite coatings in reducing the diffusion of free silicon from the Si-containing ceramic coupons was determined by subjecting the assemblies to thermal exposures in a range of about 900 to about 1200° C., followed by metallographic examination and EDXA (energy dispersive x-ray analysis) analysis of cut sections of the assemblies.
[0024] A first specimen subjected to about 100 hours at about 1100° C. exhibited a zone of Kirkendall voids resulting from the diffusion of chromium to the surface region of the Hastelloy X coupon. However, EDS analysis showed no evidence of the penetration of silicon into the superalloy. The mullite coating on the ceramic coupon was still intact after the test. An EDS profile beneath the surface of a second specimen held for about 100 hours at about 1200° C. indicated the presence of a small amount of silicon on the coupon surface, but no silicon within the Hastelloy X superalloy itself.
[0025] In a separate investigation, additional superalloy coupons were provided with aluminide coatings prior to testing. The coupons were polished rectangular coupons of the nickel-base superalloys Inconel 718, Inconel 738, Rene 80, Udimet 500, and Udimet 700. The aluminide coatings were deposited using a pack cementation process that entailed embedding the superalloy coupons in a powder mixture having an approximate composition of 5.8% aluminum, 0.2% NH 4 F, and 94% alumina. The coupons and powder mixture were heated in a covered retort to about 1050° C. for about two hours in an atmosphere of argon. During this procedure, a diffusion coating of dense nickel aluminide β-NiAl was formed on all surfaces of the coupons to thicknesses of about 10 to about 100 micrometers. After removal from the powder mixture, the coated coupons were lightly polished to remove any adhering alumina particles, assembled with Si-containing Silcomp (Si—SiC) coupons, and held at about 1150° C. for about 120 hours.
[0026] At the conclusion of the test, the aluminide coatings were found to have prevented the formation of brittle silicide phases in the underlying superalloy coupons. Because aluminide coatings grow a dense coherent layer of alumina on their surfaces, this alumina layer was concluded to have prevented migration of silicon across the superalloy-ceramic interface. Accordingly, it was concluded that, in addition to a deposited alumina layer, a thermally-grown alumina layer could effectively serve as an oxide barrier layer for purposes of this invention.
[0027] From the above, it was concluded that superalloys coupled with a Si-containing ceramic component and heated to temperatures of 900° C. and above undergo silicon diffusion across the superalloy-ceramic interface, resulting in the formation of brittle suicides in the superalloy, with the depth of penetration largely dependent on temperature and time. Exposures of as little as 500 hours at 900° C. resulted in silicon penetrating 20 micrometers, which is believed to be detrimental to the properties of the superalloy, especially if used as hot stage components of industrial gas turbines and aircraft gas turbine engines. Silicon diffusion was alleviated at temperatures of up to 1200° C. by the application of YSZ, alumina, chromia, and titania diffusion barriers to the superalloy component and/or mullite to the Si-containing ceramic component, so that these oxide coatings are interposed between the superalloy and ceramic components.
[0028] While the invention has been described in terms of one or more particular embodiments, it is apparent that other forms could be adopted by one skilled in the art. Therefore, the scope of the invention is to be limited only by the following claims.
|
A method for inhibiting diffusion of silicon into a support structure from a component formed of a silicon-containing material, and an assembly formed thereby. The component is supported and contacted by the support structure so as to define a contact interface therebetween. An barrier coating is present on the component and/or the support structure, so as to be disposed at the contact interface to prevent direct physical contact between the silicon-containing material and the superalloy substrate.
| 2
|
This is a continuation in part of applicant's copending application Ser. No. 07/978,490 filed Nov. 18, 1992, now U.S. 5,295,946.
BACKGROUND OF THE INVENTION
This invention relates to devices for overcoming male impotence and more particularly to a device applied externally to the shaft of the penis that inflates to constrict the shaft to enhance rigidity.
With advancing age, and also in certain pathological conditions, men may not be able to achieve an erection with sufficient rigidity for satisfactory coitis. Various devices of the prior art for overcoming the problem are surgically implanted within the penis. Some are permanently rigid and hinged. Others provide a flaccid inflatable chamber which becomes rigid when inflated with fluid. The inflating apparatus is also implanted within the body. These invasive procedures destroy normal tissue, they are attended by the usual surgical risks, such as infection and hemorrhage, and they are not always successful. There is little chance of restoring normal function when they are removed.
There is no way to temporarily try the devices to predict success following the operation. It is devastating to go through the expense, trauma, and risk of an irreversible procedure and then find out that it does not improve function. It is also discouraging to the physician to deal with the dissatisfied patient for whom he has recommended the procedure. Non surgical treatments includes use of a vacuum chamber to expand the penis followed by a constrive cuff at the base.
U.S. Pat. No. 4,407,275 issued Oct. 4, 1983 to Schroeder discloses a semi rigid annular ring having individual expandable chambers on the internal wall that is applied to the outside of the penis. A multiple lumen flexible conduit connected to the ring has individual connections for each chamber connecting to a pressure bulb and valve arrangement remote from the device for expanding and contracting the chambers in sequence in a wave fashion to allow only one chamber at a time to be pressurized, sending pressure down only one of the lumens at a time. This is a cumbersome, and complex apparatus which may allow blood to pass back to the heart while a chamber is being depressurized.
The Physiology of Physical Impotence
The penis shaft is made up of three cylindrical masses of erectile tissue covered by skin. The erectile tissue masses are composed of large venous sinusoids or spaces which are fed by blood from arteries and drained by veins. They contain very little blood when not aroused. When aroused, the arteries pump extra blood to the tissue and the penis enlarges. The veins draining the sinusoids are equipped with constrictor muscle to block off venous drainage during arousal. This causes the sinusoids to engorge with blood at arterial pressure. The inflated erectile tissue expands to fill the skin of the penis tightly, resulting in an enlarged and rigid organ.
In many cases of impotence, there is adequate arterial blood supply, but apparently inadequate closing off of the venous channels to inflate the sinusoids to maintain satisfactory rigidity or erection.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a temporary, non-invasive, inexpensive device to overcome impotence that is completely under the control of the user. It is another object to provide such a device that will readily fit a user regardless of the size of the organ. It is yet another object that the device be safe and harmless and not disturbing to the user or his female partner.
The device of the invention comprises an inflatable cuff means which completely encircle the shaft of the penis at its proximal portion near the pubic bone. The cuff has a substantial length, extending distally toward the glans a distance preferably of thirty-three to fifty millimeters. The cuff is inflated with fluid by a squeeze bulb with either liquid or gas. The outer wall of the cuff does not stretch readily so that its diameter remains unchanged by inflation. The inner wall, adjacent the penis, expands during inflation so that its diameter decreases until it compresses the shaft of the penis, obstructing the venous drainage thereof. This causes the venous sinusoids to engorge with blood, causing an erection.
The entire inner wall does not expand uniformly during inflation. The device is so constructed that the proximal portion of the cuff, i.e. the portion closest to the body, expands first. Then, after the venous return is blocked, the inflation of the cuff and constriction of the shaft advances distally until the entire cuff is inflated and forced tightly against the shaft. This action forces the trapped blood into a smaller portion of the shaft, further expanding the sinusoids and enhancing rigidity. The penis is hard and capable of normal coitis with the device in place with normal sensations. It is not ordinarily felt by the female.
When fluid pressure is released by the user, the cuff deflates, and the penis becomes flaccid. The device is removed for later reuse. It causes no permanent changes to the penis. If it is not successful, no harm has been done. Ordinarily, the user must be sexually aroused by massage, foreplay, or by use of a vacuum chamber before inflating the cuff for successful operation. The inflatable cuff is a sequentially activated tourniquet which constricts the shaft progressively along the proximal to distal axis.
The cuff is inflated by means of a hand operated pressure bulb connected to the cuff by a single lumen tube. The sequential filling of the individual chambers, beginning at the proximal end and progressively pressurizing chambers distally is controlled by internal valves in the cuff. The bulb and single lumen tube may be detached from the cuff after all the chambers have been inflated, before intercourse for enhanced sensory experience. A check valve and quick disconnect simplify this procedure.
These and other objects, advantages and features of the invention will become more apparent when the detailed description is studied in conjunction with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a device of the invention.
FIG. 2 is a side elevation view, partially broken away, of a device of the invention.
FIG. 3A is a sectional view taken on line 99--99 of FIG. 1.
FIG. 4A is a sectional view taken on line 99--99 of FIG. 1 with another internal structure in uninflated condition.
FIG. 4B is a sectional view of the device of FIG. 4A in one-third inflated condition.
FIG. 4C is a sectional view of the device of FIG. 4A in two-thirds inflated condition.
FIG. 4D is a sectional view of the device of FIG. 4A in fully inflated condition.
FIG. 5A is a sectional view taken on line 99--99 of FIG. 1 with another internal structure.
FIG. 6 is an exploded perspective view of the device of FIG. 2.
FIG. 7 is an exploded perspective view of another embodiment of the invention.
FIG. 8A is a view as in FIG. 4A of an embodiment with a non-resilient inner surface layer.
FIG. 9 is a diagrammatic illustration of another embodiment of the invention in plan view.
FIG. 10 is a sectional view through line 10--10 of FIG. 9.
FIG. 11 is a sectional detail view of a valve of FIG. 9 in filling mode.
FIG. 12 is a sectional view as in FIG. 11 with valve in emptying mode.
FIG. 13A is a diagrammatic sectional view of another valve in closed mode.
FIG. 13B is a view as in FIG. 13A in filling mode.
FIG. 13C is a view as in FIG. 13A in emptying mode.
FIG. 14A is a diagrammatic sectional view of another valve in closed mode.
FIG. 14B is a view as in FIG. 14A in filling mode.
FIG. 14C is a view as in FIG. 14A in emptying mode.
FIG. 15A is a diagrammatic view of a valve arrangement with a middle chamber filling.
FIG. 15B is a view as in FIG. 15A with first chamber filling.
FIG. 15C is a view as in FIG. 15A with chambers emptying.
FIG. 15D is a sectional view taken through line 1 of FIG. 15A.
FIG. 16A is a diagrammatic view of a valve arrangement with middle chamber filling.
FIG. 16B is a view as in FIG. 16A with first chamber filling.
FIG. 16C is a view as in FIG. 16A during emptying.
FIG. 16D is a sectional view taken through line 2--2 of FIG. 16A.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now first to FIGS. 1, 2 and 4A, B, C and D, a penis 1 is shown in phantom with a shaft 2 and arrow 3 indicating the proximal to distal axis and the inflatable penile erection device 4 of the invention enclosing the shaft 2 at its base 5. The device 4 is comprised of an inner circumferential surface layer 6 of a thin, resilient, stretchy material. Surrounding the inner surface layer are a series of parallel spacer bands 7, and surrounding the spacer bands is an outer, less stretchy, circumferential surface layer 8 which together define three parallel annular expandable spaces 9, 10, 11. An inflating bulb 12 and quick disconnect check valve 13 are connected through single lumen tube 14 to the first space 9 at connection 21. Squeezing the bulb forces fluid, either liquid such as water or gas such as air, into the first space 9 under pressure causing the space to expand. The inner circumferential surface layer being thinner and more stretchable than the outer circumferential surface layer, it stretches inward, reducing the inside diameter 15 which is forced against the penile shaft at its base 5, thereby constricting the venous return from the penis and trapping blood therein as shown in FIG. 4B. A valve 16 provides a fluid communication between space 9 and space 10. After space 9 is expanded, when pressure in space 9 reaches a preset value, fluid moves through valve 16 into space 10 which expands as it fills as shown in FIG. 4C. When space 10 is filled, pressure builds up to another higher preset value, and fluid moves from space 10 through a second valve 17 into space 11 which then fills and expands as shown in FIG. 4D. As spaces 10 and 11 expand sequentially and distally in the direction of arrow 3 along the proximal to distal axis, the shaft is further compressed, causing the trapped blood to be forced distally along the shaft, increasing the turgor and rigidity of the penis. The device may be constructed from a series of endless bands cemented together.
FIG. 6 illustrates another embodiment in which three rectangular strips are joined together, a thin, resilient, stretchy, inner strip 18, a thick, non-stretchy, outer strip 19, and a spacer strip 20 sandwiched between the two which provides the partitions 7, dividing the assembly into three parallel expandable spaces 9, 10 and 11. Fastening means 22 and 23 at the opposite ends of the assembled strip provide means for joining the two ends together after the device is wrapped around the penis. This permits adjustment to organs of different diameters. The fastening means may be hook and loop fasteners, adhesives or other means well known in the art. The bulb 12 and single lumen tube 14 are connected to the first expandable space 9. Fluid connection valve 16 provides for filling of space 10 only after space 9 is pressurized. Fluid connection valve 17 provides for filling space 11 only after space 10 is pressurized.
FIG. 7 shows another embodiment of the invention in which an extruded three channel tube 24, preferably molded of a thermoplastic elastomer, is formed into a circular band 25 with connector 26 providing selective access to the three expandable channels 9, 10 and 11 via rotation of internal valve plug 27 which is provided with fluid under pressure through a pressure bulb and single lumen tube as shown above. With this system, the valve connects the pressurizing fluid first to space 9 until it is expanded. The plug 27 is then rotated until space 9 is sealed and space 10 is connected to the fluid source until it is expanded. The plug is then rotated until space 10 is also sealed and space 11 is connected. After the space 11 is expanded, the plug is again rotated to seal space 11 also, to produce effective erection of the penis. FIG. 3A shows an embodiment in which a single expandable space 28 is provided with an inner stretchable circumferential surface which is thinner and more stretchable at its proximal end 29 and becomes thicker and progressively less stretchable toward the distal end 30 thereof. As shown in phantom, the inner diameter becomes reduced progressively from proximal to distal end of the cuff as the inner surface layer stretches under the force of the inflating fluid.
Referring now to FIG. 5A, an embodiment is shown in which three expandable spaces 9, 10 and 11 are provided with increasing thickness of the resilient inner layer 31 from proximal to distal ends of the cuff. When the spaces are pressurized simultaneously, space 9 will expand first, followed by space 10 and then space 11.
The device is typically formed of a soft, resilient, stretchable elastic material having a durometer of 30 and a 2000 P.S.I. tensile strength such as natural rubber, silicone rubber, polyurethane or thermoplastic elastomer.
Referring now to FIG. 8 an embodiment is shown in which the inner layer 32 as well as well as the outer layer 33 is made of a non-stretchable material such as polyester providing a flaccid inner surface layer with enlarged spaces 9, 10, 11. When not pressurized, these spaces are readily collapsed as shown. The fluid transfer means is arranged to pressurize the three spaces sequentially, along the proximal to distal axis as shown, for example, in FIG. 7.
Referring now to FIGS. 9 and 10 a tourniquet 40 of the invention is provided with hook and loop fasteners 22, 23 to form a cuff adjustable to various diameters, with three expandable spaces 9, 10, 11 arranged to be expanded in that sequence, while space 9 is positioned most proximal. A quick connect check valve/release valve 21 connects a single lumen flexible tube 14 to a pressure generating squeeze bulb 12. Pressure flows from the bulb, through tube 14 and valve 21 into space 9. As pressure builds up, the flexible inner wall 6 inflates inward compressing the shaft until pressure is greater than venous pressure but less than arterial pressure. This simulates the physiological erection process in which the penis becomes engorged with blood as blood enters the organ but cannot leave. When pressure reaches a preset value at valve 41 it opens so that pressurizing fluid enters and inflates space 10 constricting the engorged penis distal to the constriction from space 9. This forces some of the trapped blood more distally to further enlarge and stiffen the organ.
When pressure reaches a preset value at valve 42, it opens so that pressurizing fluid may enter space 11, further constricting the penis distally and forcing more blood distally. The cuff may be made with any number of constricting bands. The valves 41 and 42 may be arranged so that valve 41 opens at a first preset pressure and valve 42 opens at a second preset pressure greater than the first. Alternatively, they may open at the same pressure, relying upon the fact that considerable pressure cannot build up at the input of a valve until the space open to it is filled. The opening pressures are preset at a value below the usual arterial pressure.
A combined preset check valve and release valve 44 is shown in the filling mode at FIG. 11 and the release mode at FIG. 12. Pressure at inlet 43 must be great enough to overcome bias spring 45 to lift ball 46 from seat 47 in order to fill a space. Input pressure keeps flap valve 48 closed. When input pressure drops below a preset value, flap valve 48 opens, to release the pressure after use.
FIGS. 13A, 13B and 13C show another valve configuration serving a similar purpose, with flap valve 49 in ball 46. Input pressure not great enough to open the valve in FIG. 13A, great enough to open the valve at FIG. 13B and the releasing mode at FIG. 13C.
FIGS. 14A, B and C show an alternative valve with a resilient body 49 providing the necessary spring bias.
The valve arrangement of FIGS. 15A-C show a valve cover flap 50 which closes off orifice 51 until the space expansion pulls the flap away from the orifice. This arrangement ensures that the valve won't open until the preceding space is inflated.
The valve arrangement of FIGS. 16A-C show a deformable slit opening 52 between spaces. As a space 53 inflates, the slit deforms enough to open a channel to the next space 54. When inlet pressure is released, the pressure slowly leaks out through the narrow slits. The user may simply open the fasteners to release the entire cuff so that slow deflation is not a problem.
The above disclosed invention has a number of particular features which should preferably be employed in combination although each is useful separately without departure from the scope of the invention. While I have shown and described the preferred embodiments of my invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that certain changes in the form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention within the scope of the appended claims.
|
A device for affecting or enhancing erection of the penis comprises an external inflatable cuff which encircles the shaft of the penis at its base and extends distally. The cuff is provided with a plurality of volume expandable annular spaces arranged parallel to one another. The spaces are filled with fluid under pressure from a squeeze bulb to affect a tourniquet action. The spaces are inflated sequentially in a proximal to distal direction. As the spaces become sequentially pressurized, the inner diameter of the cuff is reduced, constricting the penis and trapping blood within the shaft and forcing it distally to thereby increase the rigidity of the penis.
| 0
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to poles for elevating items, and in particular to apparatus and methods of attaching cross-arms to vertical poles.
2. Problems in the Art
Different ways to attach cross-arms to vertical poles have evolved over the years. Wooden poles remain one popular method of elevating structures. Cross-arms are generally attached to wooden poles by clamps which surround the solid wooden pole. Clamps are also used to attach cross-arms to concrete and hollow metal poles. Some of the problems with the use of clamps include the risk that the clamping hardware will deteriorate or fatigue over the years. This includes the possibility of the clamping hardware loosening and making the cross-arm subject to failure. It is also time-consuming and sometimes difficult to install cross-arms with clamps. Many times the installation must occur after the vertical pole has been anchored in the ground. The installer must therefore be elevated to the location that the cross-arm is to be placed and many times has to work from substantial heights with cross-arms that are heavy and unwieldy. Installation of cross-arms is also subject to the risk that the installer will not be completely accurate in the installation process, including insuring the correct alignment of the cross-arm to the pole, which many times can be critical. One example where such alignment is critical is when the cross-arm holds sports lighting fixtures which collectively, for several poles and several lighting fixtures, optimally will have precise aimings based on pre-calculations of height and orientation of the cross-arm.
Because of the afore-mentioned difficulties, the owner of the present invention developed what will be called a “spacer” that could be attached at one end to the pole and at the other end to a cross-arm. An example of this development can be seen in FIG. 3 . Spacer 2 consists of a hollow body having one end having a curved cut-out which matches the exterior of the pole. The other end is square-cut and matches a flat side of the cross-arm. The spacer 2 could be welded to the metal pole and the metal cross-arm. The structure then does not bear the risk of a loosening of clamping hardware and is very strong.
Another benefit of spacer 2 is the fact the it holds the cross-arm a distance away from the pole. This frees up even the portion of the cross-arm right in front of the pole to be used to suspend items, including the mounting structure for a lighting fixture. Thus, a portion of the cross-arm that otherwise could not be easily utilized with some other mounting systems, can be utilized.
In the example shown in FIG. 3, spacer 2 could be utilized with a pre-fabricated vertical pole section 4 made of hollow metal and having an upper end 6 and a lower end 8 . Aperture 7 along pole top 4 would be put in the position where each cross-arm 3 was to be located. Spacers 2 , being hollow, would then be welded between pole top 4 over an aperture 7 , and then to a cross-arm 3 which in turn would have an aperture 7 ′, which would be surrounded by the other end of spacer 2 . In this manner, not only could a pole top with cross-arms be pre-assembled at the factory, but the cross-arms and pole top could also be pre-wired through the hollow interior of section 4 , through aperture 7 , through hollow spacers 2 , and through apertures 7 ′ in cross-arms 3 . This lends itself to pre-construction of an entire pole top, including the items to be elevated, for example, electrically powered sports lighting fixtures that would be attached as indicated at reference numeral 1 to various spaced-apart locations along cross-arms 3 (other locations not shown).
Spacers 2 at FIG. 3 therefore achieve the function of allowing a strong factory-assembled connection between pole top 4 and the cross-arms 3 , along with the ability to pre-wire the same. The pole top 4 , with pre-installed and pre-wired cross-arms 3 , could be shipped pre-assembled to location. The bottom 8 of pole top 4 could then be slip-fit over the top of the main part of the pole to be erected, with sports lighting which could be many tens of feet tall (including over a 100 feet tall).
Such a combination is described in more detail in U.S. Pat. No. 5,600,537, issued Feb. 4, 1997, co-owned by the owner of the present application, and the contents thereof are incorporated by reference herein.
Although the structure shown in FIG. 3 works well for its intended purpose, in certain situations the structure, over long periods of time, has developed fractures at or near the junction of spacers 2 and hollow metal pole or pole top 4 . Although it is not precisely known how and why such fractures occur, one explanation is that in certain environmental conditions, oscillation of cross-arms is believed to occur. Over time the oscillations or vibrations are believed to be transferred through spacers 2 to the relatively thin walled tubular pole 4 . It is believed that spacers 2 can act somewhat like punching tubes which fracture the vertical tube 4 at their junction. It is believed that such fatigue problems are caused by a repeating or long-term cyclic vibration. Many times this is believed to be set up when, for example, lighting fixtures on the order of 30 ″ diameter are supported on the cross-arms and the wind causes such vibration.
It is therefore believed that there is room for improvement with respect to the method of spacing cross-arms 3 from pole 4 as shown in FIG. 3, or, at least, room for trying to eliminate any punching action by spacers 2 relative to the pole.
It is therefore a primary object of the present invention to provide an apparatus and method for connecting and spacing a cross-arm relative a pole section which improves over or solves the problems and deficiencies in the art.
Further options, features, and advantages of the invention include an apparatus and method which:
1. Reduces or eliminates punching action by a spacer between cross-arm and pole.
2. Provides more support of the cross-arm relative to the spacer and the pole relative to the spacer.
3. Reduces or eliminates any punch-through problems between cross-arms and pole.
4. Is durable and long-lasting.
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus and method for attaching one or more cross-arms to a vertical pole where the cross-arm is held at a somewhat spaced apart position from the pole. With respect to the apparatus, the invention comprises a spacer having a first portion including a aperture for receipt of the vertical pole. A second portion, for attachment to a cross-arm, extends from the first portion transversely relative to the aperture.
With regard to the method of the invention, a spacer member is attached in a manner so that it surrounds a part of the pole. A portion of the spacer member extends transversely away from the pole and a cross-arm is attached to the extended part of the member.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the invention associated with a pole top section.
FIG. 2 is a partially exploded view of FIG. 1 .
FIG. 3 is a partially exploded view similar to FIG. 2, but showing a prior spacer between pole and cross-arm.
FIG. 4 is an enlarged side elevational view of a spacer according to Preferred embodiment of the present invention.
FIG. 5 is a top plan view of FIG. 4 .
FIG. 6 is an enlarged side elevational view of FIG. 1 with a top cover for the pole top section shown in exploded fashion.
FIG. 7 is a top plan view of FIG. 6 with the top cover removed and not shown.
FIG. 8 is a front elevational view of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For a better understanding of the invention, a detailed description of one preferred embodiment the invention can take will now be set forth. Frequent reference will be taken to the drawings. References numerals will be used to indicate certain parts or locations in the drawings. The same reference numerals will be used to indicate the same parts and locations throughout the drawings unless otherwise indicated.
The preferred embodiment is a connection between a vertical pole section and a cross-arm. More specifically, the preferred embodiment's designed function is to suspend from an elevated height high-intensity light fixtures for wide-area sports lighting or similar applications. Therefore, the cross-arms, the connector, and the pole must be sufficiently strong and durable to suspend the plurality of fixtures, and in many cases a plurality of cross-arms, each with fixtures, at substantial heights. Thus, this strength and durability must not only apply to the inherent weight of all of those components, but also to such things as wind-load that creates additional stresses on such apparatus. All of this is well-known in the art.
For a description of some of the considerations that go into designing high-intensity lighting systems, reference can be taken to U.S. Pat. No. 5,600,537.
The specifics regarding how the lighting fixtures are mounted to the cross-arms and how the entire vertical pole is constructed and anchored in the ground will not be discussed here and are matters well within the skill and knowledge of those skilled in the art. One way is shown and described in U.S. Pat. No. 5,600,537. A comparison will be made with a prior system to assist in an understanding of the advantages of the invention.
As stated earlier, the configuration of FIG. 3 provided a strong durable way to mount metal cross-arms to metal hollow poles. It eliminates the need for clamps or other securing hardware and allows precise manufacturing, construction, preassembly, and orientation of the relative parts to one another. Pole section 4 is several feet long and, therefore, could be worked on in the factory without difficulty. In particular, it could be transported to distance locations in regular sized transportation vehicles such as conventional semi tractor-trailer combinations. The size and configuration of spacer 2 is welded between the metal of pole 4 and a cross-arm 3 , and as mentioned above allowed pre-wiring. Welding of the pieces would be within the skill of those skilled in the art. The dimensions of spacer 2 would depend upon a number of factors including the size of pole 4 , the size and length of cross arm 3 , and the items intended to be carried by cross-arm 3 . An example of one spacer 2 is as follows:
Material
{fraction (3/16)}″ Ga. Tubing, ASTM A
500 Grade B
Width side to side
4″
Length front to back
2.215″
Thickness
2″
Radius to receive pole
2⅜″
For larger radius poles, the dimensions change as set forth in the following table.
Radius Of Pole
Width
Length
2⅞″
3¾″
5{fraction (3/16)}″
5″
6″
8″
2.542″
2.645″
3.045″
As can seen in FIG. 3, spacer 2 does mate with part of the circumference of pole 4 , but no more than approximately 180°. The other end of spacer 2 abuts a vertical flat surface of cross-arm 3 .
A preferred embodiment of the present invention, in comparison, is shown at FIGS. 1 and 2. Spacers 10 , like spacers 2 , connect cross-arms 3 to pole top section 4 . Spacer 10 includes a main body 12 that includes a portion 14 which completely surrounds pole 4 . A second portion 16 is essentially an extension from main body 12 . As can be seen (see also FIG. 4 ), second portion 16 has a cut-out portion 18 which receives a cross-arm 3 . As shown in FIGS. 1 and 2, therefore, extension portion 16 , with its cut-out 18 , abuts and allows securement between spacer 10 and a cross-arm 3 not only on one vertical flat side of cross-arm 3 , but also extends over the top flat vertical part of cross-arm 3 .
The specific construction of spacers 10 can be seen in more detail in FIGS. 4 and 5. Body 12 consists of an upper surface 20 and a bottom surface 22 , and a side wall 24 . As can be seen specifically in FIG. 5, an aperture 26 exists in top wall 20 and a similar aperture 28 exists in bottom wall 22 . Apertures 26 and 28 are aligned along a central axis 30 . The radius of apertures of 26 and 28 may or may not be the same depending on whether pole section 4 has a constant radius or is tapered from top to bottom. The interior of body 12 is generally hollow. Body 12 is open to its interior at the area defined by cut-out 18 .
The following table provides dimensions (see FIGS. 5 and 6) with respect to a spacer 10 associated with a 6.06″ diameter opening or aperture 26 :
LETTERS
DIAMETER
A
3.13″
B
7.38″
C
10.69″
D
1.94″
E
7.00″
R
3.03″
Spacer 10 can be made of the material as described with regard to spacer 2 or other similar materials such as are well-known in the art.
FIGS. 6-8 illustrate the assembly of spacers 10 to a pole top 4 and then the attachment of cross-arms 3 to spacers 10 . By referring to FIG. 6, the uppermost part of pole section 4 (indicated at reference numeral 32 ), can be formed of hollow metal tube of 6.06″ approximate outside diameter. The diameter can be constant all the way down to step 36 between upper section 32 and lower section 34 of pole portion 4 . The spacers 10 of FIGS. 4 and 5 could be slipped over the top end of upper part 32 of pole top 4 and slid down to their intended point of attachment. By referring back to FIG. 2, both spacers 10 would be positioned at a point along pole 4 where apertures 7 exist in pole 4 . By means well within the skill of those skilled in the art, both spacers would be rotationally adjusted so that they are aligned with holes 7 and so that extensions 16 point in the correct orientation. Both spacers 10 would then be welded into place on upper part 32 of pole section 4 .
FIG. 6 shows that the cover-plate 5 for pole section 4 is detachable for access to the hollow interior of pole section 4 .
As FIG. 6 shows, spacers 10 completely surround pole 4 and thus have attachment support and structural support all the way around pole 4 .
The next step would be to attach cross-arms 3 to spacers 10 . As shown in FIGS. 6, 7 , and 8 , the cross-arms could then be brought into place in cut-outs 18 . By methods well within the skill of those skilled in the art, each cross-arm 3 can be accurately positioned relative to spacers 10 and then welded into place. As shown in FIGS. 6-8, spacers 10 would not only abut the closest vertical side of cross-arm 3 , but also the top of cross-arm 3 for additional support. Note how the top side of extension 16 is sloped down or tapered to its outer edge.
Therefore, by comparing FIGS. 2 and 3, the major differences between spacers 2 and 10 can be seen.
The included preferred embodiment is given by way of example only and not by way of limitation to the invention which is solely described by the claims herein. Variations obvious to one skilled in the art will be included within the invention defined by the claims.
|
An apparatus and method for connecting a cross-arm to a pole. The apparatus includes a portion which completely surrounds the pole and an extending member extending transversely or outwardly from the pole. A cross-arm is connectable to the extended member.
| 4
|
The invention relates to apparatus for detecting rotation a rotary element such as the spinner of a water meter, and more particularly a water meter integrated in a calorimeter for metering the energy delivered by a hot water circuit.
BACKGROUND OF THE INVENTION
Conventionally most water meters include a totalizing counter which is driven mechanically, i.e. rotation of the spinner drives the index wheels of the meter via a transmission which is mechanical and/or magnetic.
More recently, proposals have been made to detect rotation of the spinner by means of a proximity sensor placed facing a rotary element integral with the spinner and designed to detect the passage of a mark placed eccentrically on the rotary element. For example, the proximity detector may be based on an inductive method, in which case the mark is constituted by a material whose magnetic and/or electrical characteristics are different from the remainder of the rotary element. Such detectors nevertheless suffer from drawbacks.
Firstly there are various parameters that vary as a function of time; for example for a water meter integrated in a calorimeter, these parameters include: the temperature of the water that may cause the characteristics of the detector to vary; the power supply voltage to the detector circuit, in particular when the power supply is provided by a battery; and the distance between the proximity detector and the rotary element because of the way the spinner rises at high speed.
In general, there are various parameters that vary from one detector to another and that are difficult and expensive to bring under control in mass production. For example, for an inductive type of detector, such parameters include the inductance of the coil and its Q-factor, which means that each detector needs to be calibrated or else that components need to be sorted.
An object of the invention is to remedy these drawbacks by using a system that is adaptive and includes at least two proximity detectors.
SUMMARY OF THE INVENTION
The present invention provides a device for detecting the rotation of a rotary element about an axis XX', the device comprising:
a) m proximity detectors situated in a plane perpendicular to the axis XX' on m radial directions;
b) a mark fixed to said element eccentrically relative to the axis XX', said mark being suitable for modifying the response of the proximity detectors when said element is rotating;
c) a power supply for powering said proximity detectors;
d) selection means for selecting a series of m-1 proximity detectors to be powered; and
e) processor means firstly for observing changes in the signals delivered by each of the detectors in said series using parameters representative of such changes, thereby identifying the passage of the mark past one of the detectors situated at the end of said series, and secondly, as soon as such a passage has been identified, for:
deducing therefrom the number of revolutions;
actuating the selection means so as to cause it to select a new series of m-1 proximity detectors excluding the detector at which passage of the mark has just been identified; and
reinitializing said parameters in readiness for observing changes in the forthcoming signals from said new series in such a manner that the parameters reinitialized in this manner are representative of the fact that, at that time, the mark cannot be at one of the detectors of said new series.
Advantageously, the rotary element is made of non-metallic material; the mark is constituted by a metalized portion of said rotary element; each proximity detector is constituted by an oscillator circuit including a coil and a capacitor; and the power supply means comprise a pulse generator feeding each detector in said selected series in succession, with pulses of about 3 V at a frequency lying in the range 400 Hz to 800 Hz.
In a first embodiment for which m=2, the processor means comprise:
for each signal delivered, means for counting the number N of periods in the signal exceeding a predetermined threshold value Vthreshold;
for each value N obtained in this way, means for comparing N with two parameters Nmax and Nthreshold representative of the said changes and for calculating two new values of said parameters, said values of said parameters concerning said changes being calculated as follows:
if N>Nmax
Nmax=N
Nthreshold=f(Nmax) with f being a linear function of Nmax and with Nthreshold<Nmax
if Nthreshold<N<Nmax
Nmax=Nmax
Nthreshold=Nthreshold
if N<Nthreshold
Nmax=0
Nthreshold=0
and means for generating said control signal for actuating said selection means and for incrementing an index used for counting the number of revolutions when N is less than Nthreshold.
In a second embodiment, m=3, i.e. the device includes three detectors, in which case processing is applied to the signals delivered by two detectors Le=Lp or Ln. In this second embodiment, the processor means comprise:
for each signal delivered by a detector Le, means for counting the number N of periods that exceed a predetermined threshold voltage Vthreshold;
for each value N obtained in this way, means for comparing N with a parameter Nmax(Le) representative of changes in the signals delivered by the detector Le, and with a fixed parameter Nthreshold which is valid for all three detectors, and for calculating new values of said parameters as follows:
if N>Nmax
Nmax(Le)=N
if Nmax(Le)-Nthreshold<N<Nmax(Le)
Nmax(Le)=Nmax(Le)
if N<Nmax(Le)-Nthreshold
Nmax(Lp)=0 and Nmax(Ln)=0
when N<Nmax(Le)-Nthreshold, means for applying a signal IP or IN to the counter circuits as a function of whether the detector Le=Lp or Ln, the signals IP and IN being respectively representative of one-third of a revolution in the positive direction of rotation and in the negative direction of rotation, and for selecting two new detectors, excluding the detector at which the mark was detected.
Preferably, the processor means also include:
means for ensuring that each detector is operating properly by comparing the number N with a value Nmin; and
if one of the detectors should break down, means enabling the device to continue to operate using the other two detectors.
A particularly advantageous application of the invention lies in water metering.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described by way of example with reference to the accompanying drawings, in which:
FIG. 1 shows a first embodiment of the invention using two detectors;
FIG. 2 is a diagram of the circuits associated with the two proximity detectors of FIG. 1;
FIG. 3 shows the signals obtained using inductive type proximity detectors;
FIG. 4 is a flow chart showing the way in which signals are processed in the first embodiment of the invention;
FIGS. 5 and 6 show a second embodiment of the invention including three proximity detectors and enabling direction of rotation to be detected;
FIG. 7 is a flow chart of the logic that applies to successive sequences in the second embodiment; and
FIG. 8 is a flow chart showing the processing for analyzing changes in the signals delivered in the second embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 shows a first embodiment of the invention in which the rotary assembly is constituted, for example, by the spinner 1 of a flow meter (not shown) and by a disk 2 which is integral with the spinner 1. While a fluid such as water is flowing, the spinner 1 and the disk 2 rotate about an axis XX'. The speed of rotation of the rotary element is directly related to the instantaneous flow rate of the fluid.
Two proximity detectors L0 and L1 situated in a plane P perpendicular to the axis XX' and at two different radial directions relative to the axis XX' respond to the proximity of a mark 5 integral with the disk 2 and disposed eccentrically relative to the axis of rotation XX'. It follows that when the rotary element (spinner 1 and disk 2) is rotated, the response of the proximity detectors L0 and L1 changes as a function of the position of the mark 5.
By way of illustration, the two proximity detectors L0 and L1 are magnetic coils 3a and 4a coupled in parallel with capacitors 3b and 4b, thereby forming two oscillator circuits disposed on two opposite radial directions. The disk 2 is made of non-metallic material, e.g. molded plastic, and the mark 5 is a metallized radial sector on the disk.
FIG. 2 shows the architecture of the circuits associated with the proximity detectors L0 and L1. A power supply 10, e.g. a battery, applies the energy required to excite one or other of the two proximity detectors L0 and L1 via a switch 11.
Processor means 12 connected via the switch 11 serve to analyze the signals delivered by the excited proximity detector so as to identify passage of the mark 5 close to the active proximity detector.
The passage of the mark 5 past the active detector is identified by analyzing changes in the signals delivered in succession by the active proximity detector, e.g. by comparing the signal as delivered with parameters representative of said changes and calculated on the basis of the preceding signal(s).
Once the processor means 12 have identified the passage of the mark close to one of the proximity detectors, they trigger the following stages:
they deliver a control signal to actuate the switch 11 so as to select the other proximity detector;
they deliver a rotation signal representative of the rotary element performing a half turn and used for controlling a counter circuit that stores the number of turns performed by the rotary element; and
they reinitialize the analysis parameters for use with the following signal coming from the newly-connected other proximity detector, thereby ensuring that the reinitialized parameters are representative of the mark not being in the vicinity of the newly-connected detector; the reinitialized parameters are thus independent of the distance between the detector and the rotary element.
It is thus possible to track the approach of the mark towards the newly-connected detector by tracking changes in the signal delivered by the detector until an indication is obtained without any possibility of doubt that the mark is beneath the detector in question.
An adaptive tracking system is thus obtained which does not require a previously fixed detection threshold. The system also takes account of the differences that exist between the two proximity sensors without it being necessary to calibrate both of the sensors and to store calibration coefficients in memory for the purpose of analyzing the signals. As mentioned above, such calibration coefficients vary not only from one detector to another, but also as a function of time, as a function of temperature, as a function of power supply voltage, and as a function of the distance between each of the detectors and the rotary element.
In addition, because only one or other of the detectors is excited in alternation, energy saving is obtained which is particularly advantageous when the system is battery powered and when the lifetime of the battery is to be several years.
Returning to the illustrative example mentioned above, there follows a description with reference to FIG. 4 of one possible way of processing the signals delivered by the oscillator circuits L1 and L2. Naturally, the person skilled in the art will be aware of other ways in which these signals may be examined.
As shown in FIG. 3, the signal delivered by the oscillator circuit is damped to a greater or lesser extent as a function of the position of the mark 5: when the metallized sector 5 is level with the magnetic coil, then the signal is strongly damped whereas when the metallized sector is remote therefrom, then the signal is weakly damped.
To evaluate the damping on the signal delivered by an oscillator circuit L1 or L2, the oscillator circuit in question is excited using pulses of about 3 V that are delivered by the power supply 10 operating at a sampling frequency of about 400 Hz. This method of operation by sampling provides considerable savings with respect to battery consumption in comparison with operating in continuous mode.
The signal delivered (block 20) is sampled and the number of periods N in the signal exceeding a voltage threshold Vthreshold is counted (block 21), with Vthreshold being taken from the power supply 10. For each value of N obtained in this way parameters Nmax and Nthreshold are calculated on the basis of the value N and on the basis of the preceding parameters Nmax and Nthreshold calculated during the preceding cycle, as follows:
a) if N>Nmax (block 22)
then Nmax=N
Nthreshold=f(Nmax) where Nthreshold<Nmax (block 24), and where the function f is a linear function in which the coefficients are determined on the basis of minimum and maximum numbers of periods exceeding the threshold voltage when the signal is strongly damped and when the signal is weakly damped; for example, Nthreshold could be selected to be equal to nNmax with 0<n<1, or Nthreshold could be selected to be equal to Nmax-b where b is a constant, and then the following sample from the same oscillator circuit is waited for;
b) if Nthreshold<N<Nmax (blocks 22 and 23) then the parameters are not changed and the following sample from the same oscillator circuit is waited for; and
c) if N<Nthreshold (block 23), i.e. if it is certain that the mark is beneath the coil, then the parameters are reinitialized, e.g. by being reset to zero:
Nmax=0 and Nthreshold=0 (block 25)
in which case the processor means (12a) deliver a rotation signal which increments the counter circuit (12b) by one half-turn, and the counter circuit in turn delivers a control signal to actuate the switch 11 and thus select the other oscillator circuit prior to the arrival of the following sample.
The embodiment described above can naturally be transposed to any other type of proximity sensor, e.g. to a sensor of the capacitive type or of the optical type.
In addition, it may be generalized to a device comprising m proximity detectors, which generalization is now illustrated by means of a second embodiment as shown in FIG. 5 in which the rotation detection device comprises three inductive type proximity detectors L0, L1, and L2 disposed on three radial directions at 120° intervals, i.e. m=3.
An oscillator 50 controls a processor unit 51 for processing the signals delivered by the detectors L0, L1, and L2, and controls the sequences in which the detectors are selected via a selector circuit 53. Two outputs from the processor unit 51 respectively marked IP for rotation signals in positive direction and IN for rotation signals in the negative direction provide the electronic counter circuits 52 with the information required to count rotations. In a particularly advantageous embodiment, all of the circuits 50 to 53 may be implemented in the form of integrated circuit technology.
Such a device has several advantages over a two-detector device as described above: in particular it enables the direction of spinner rotation to be determined (cf. FIG. 6) and to keep count separately or cumulatively of revolutions in the positive direction and in the negative direction; in addition it provides the device with redundancy in that if any one of the detectors breaks down, then the device can continue to operate on the other two detectors, albeit without being able to detect direction of rotation.
The logic processing that controls the successive sequences of the three-detector device is now described with reference to FIG. 7. The processing applies to (m-1) detectors, i.e. to two detectors of indices p and n, respectively Lp and Ln.
On starting, arbitrary initial values Lp=L1 and Ln=L2 (block 100) are taken, i.e. the device starts on detectors L1 and L2.
Initially, the signal delivered by the detector Lp is sampled (block 101) and it is verified (block 102) that this detector has not been declared to be out of operation, e.g. following a detector breakdown or a deliberate choice to operate on two detectors only. If the detector Lp is out of operation, then the index or the electronic counting circuits are informed (block 105) so that the counting circuits change the weight given to each signal IP that they receive, and the system passes directly to sampling the signal delivered by the detector Ln (block 201). Otherwise, the signal delivered by the detector Lp is analyzed and verified to see whether it is damped or not (block 103), i.e. whether the mark is being detected or not. The detailed processing for analyzing the signal and identifying passage of the mark is described below with reference to FIG. 8.
If the signal delivered by the detector Lp is not damped, then the system passes directly to sampling the signal delivered by the detector Ln (block 201). Otherwise, i.e. if the mark is detected as being level with the detector Lp, the following are performed in succession:
a signal IP is applied to the electronic counting circuits 52 corresponding to 1/3 of a turn in the positive direction of rotation (block 106);
the selected detectors Lp and Ln are altered as follows:
if Lp=L0 (block 107), then Lp=L1 and Ln=L2 (block 108);
if Lp=L1 (block 109), then Lp=L2 and Ln=L0 (block 110); or
if Lp=L2, then Lp=L0 and Ln=L1 (block 111); and
finally the signal delivered by the detector Ln is sampled (block 201).
The processing applied to the signal delivered by the detector Ln is almost identical to that described above with respect to the signal delivered by the detector Lp.
The signal delivered by the detector Ln is sampled (block 201) and it is verified that this detector is not declared to be out of operation (block 202). If it is out of operation, then the index or the counting circuits are informed (block 205) so that the counting circuits modify the weight given to each signal IP received thereby such that two signals IP correspond to one rotation and the system returns directly to sampling the detector Lp. Otherwise, the signal delivered by the detector Ln is analyzed and verified to see whether it is damped or not (block 203).
If the signal delivered by the detector Ln is not damped, then the system returns to sampling the detector Lp (block 101). Otherwise, it is verified that the detector Lp has not been declared to be out of operation (block 204) and if it has been declared out of operation, then a signal IP is applied to the electronic counter circuits (block 212) given that if one of the detectors has broken down, it is no longer possible to detect the direction of rotation. Under such circumstances it is assumed that the spinner always rotates in the positive direction of rotation. If the detector Lp has not been declared to be out of operation, then a signal IN is applied to the electronic counter circuits corresponding to 1/3 of a turn in the negative direction of rotation (block 206).
After a signal IP or IN has been delivered, the detectors Lp and Ln are reselected as follows:
if Ln=L0 (block 207), then Lp=L1 and Ln=L2 (block 208);
if Ln=L1 (block 209), then Lp=L2 and Ln=L0 (block 210); and
if Ln=L2, then Lp=L0 and Ln=L1 (block 211); and
finally the system returns to sampling the signal delivered by the detector Lp (block 101).
The sampling and the processing of the signal delivered by a detector Le=Lp or Ln (block 300) to decide whether the signal is damped or not, i.e. whether the mark is being detected or not at the detector Le in question is now described with reference to FIG. 8.
Sampling takes place at a frequency of 800 Hz, which value makes it possible to measure spinner speeds of rotation in the range 0 to 40 revolutions per second. Sampling begins by applying a drive pulse of about 3 V to the detector Le (block 301) with Le=Lp or Ln.
In response to this pulse, the detector Le delivers a damped sinewave signal at a frequency of about 250 kHz. The number N of periods above a specified threshold Vthreshold, e.g. about 0.3 V (block 302), is then counted and it is verified that the detector is working by comparing the number N with a minimum value Nmin (block 303), where Nmin is representative of the minimum number of periods, below which the detector is declared to be out of operation.
If N<Nmin, then the fact that the detector Le is out of service is stored (block 305) to inform the sequence logic (blocks 102, 202) so as to enable the device to operate with the other two detectors only but without being able to detect the direction of rotation. The counting circuits are also informed so that each signal IP delivered to the counting circuits represents 1/2 of a revolution instead of 1/3 of a revolution. Thereafter the system passes directly to waiting for the following sample (block 310).
Otherwise, i.e. if N>Nmin, the fact that the detector is in operation is stored (block 304) and the number N is compared with a value Nmax(Le)-Nthreshold (block 306), where Nmax(Le) corresponds to the parameter calculated for the corresponding detector Le during the preceding cycle and where Nthreshold corresponds to a predetermined threshold value that is valid for all three detectors.
If N<Nmax(Le)-Nthreshold, then the signal delivered by the detector Le has been damped, and that corresponds to a mark going past the corresponding detector Le. Under such circumstances, the parameters are reinitialized Nmax(Ln)=Nmax(Lp)=0 (block 307) and the system waits for the following sample (block 310).
Otherwise, a test is made to see whether N>Nmax(Le) (block 308); if so, the parameter Nmax(Le)-N is updated and the system waits for the following sample (block 310).
Finally, if Nmax(Le)-Nthreshold<N<Nmax(Le), then the parameter Nmax(Le) is not changed and the system waits for the following sample (block 310).
|
The rotation detecting device comprises m proximity detectors for detecting the passage of a mark fixed to a rotary element. Changes in the signals delivered by each of the detectors in a selected series of m-1 detectors are analyzed. Once a mark is detected at one of the sectors situated at an end of the series, a revolution counting index is incremented, a new series of m-1 detectors is selected excluding the detector which has just detected the passage of the mark, and criteria representative of changes in the signals are reinitialized for the forthcoming signals from the newly-selected series. An adaptive system is thus obtained applicable to detecting the rotation of a spinner in a water meter.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 60/031,053 filed Nov. 18, 1996, which application is incorporated herein to the extent not inconsistent herewith.
BACKGROUND OF THE INVENTION
The removal of heavy metal ions from waste solutions has received considerable study due to their toxic nature. Adsorption on solid substrates is one of the main techniques that has been studied. Substrates include inorganic substances such as alumina, ferric oxide and manganese oxide, and organic substrates such as various plants, e.g., algae and water hyacinth.
The control of ferric iron in metallurgical processing solutions is a major problem facing the industry, particularly in solutions obtained from biotreatment of iron-containing sulfide ores. In some instances, the concentration of ferric iron is 5-20 grams/liter. Use of conventional neutralization and/or precipitation techniques is inadequate and difficult to implement commercially.
The use of an acid phosphate salt, followed by pH adjustment and addition of a calcium source has been disclosed for making toxic metals such as lead, chromium, cadmium, arsenic, selenium, silver and barium less soluble in waste sludges. See U.S. Pat. No. 4,671,882 issued Jun. 9, 1987 to Douglas at al. for "Phosphoric Acid/Lime Hazardous Waste Detoxification Treatment Process." The use of phosphate materials has been disclosed for rendering lead and cadmium in solid wastes even more insoluble. See U.S. Pat. No. 4,737,356 issued Apr. 12, 1988 to O'Hara et al. for "Immobilization of Lead and Cadmium in Solid Residues from the Combustion of Refuse Using Lime and Phosphate." The use of solid calcium phosphate materials, e.g. gypsum powder, has been disclosed to fixate and stabilize leachable lead in toxic wastes. See U.S. Pat. No. 5,193,936 issued Mar. 16, 1993 to Pal et al. for "Fixation and Stabilization of Lead in Contaminated Soil and Solid Waste." Phosphorylated polysaccharides, chitin phosphate and chitosan phosphate have been disclosed as useful to adsorb heavy metal ions such as uranium. See Sakaguchi, T., et al. (1993), "Recovery and Removal of Heavy Metal Elements such as Uranium by using Phosphate Compounds," (1933) in Beneficiation of Phosphate: Theory and Practice, H. El-Shall, et al., eds., Society for Mining, Metallurgy and Exploration, Littleton, Colo., Chapter 44, p. 463.
The use of hydroxyapatite materials has been disclosed for removal of certain heavy metal ions from solution. For example, Suzuki, T., et al. (1980), "Synthetic Hydroxyapatites Employed as Inorganic Cation-exchangers," (1981) J. Chem. Soc. Faraday Trans. 77:1059-1062 discloses that ions such as Cd 2+ , Zn 2+ , Ni 2+ , Mg 2+ , and Ba 2+ are removed from aqueous solution by a mechanism involving ion exchange using synthetic hydroxyapatite. Lead (Pb 2+ ) was shown to be exchanged for Ca 2+ ions in aqueous solutions using synthetic hydroxyapatites. See Suzuki, T., et al. (1984), "Synthetic Hydroxyapatites as Inorganic Cation Exchanges," J. Chem. Soc. Farady Trans. 80:3157-3165; and Takeuchi, Y., et al. (1988), "Study of Equilibrium and Mass Transfer in Processes for Removal of Heavy-metal Ions by Hydroxyapatite," (1988) J. Chem Eng. of Japan 21:98-100. Solid calcium phosphate materials such as naturally-occurring apatite and synthetic hydroxyapatite have been disclosed as useful for in-situ immobilization of lead-contaminated soils, wastes and sediments by mixing with the lead-contaminated materials and leaving the mixture in place. See U.S. Pat. No. 5,512,702 issued Apr. 30, 1996 to Ryan, et al. for "Method for In-Situ Immobilization of Lead in Contaminated Silts, Wastes, and Sediments Using Solid Calcium Phosphate Materials." Hydroxyapatite has been disclosed as a useful component of filtering material for drinking water for removal of lead. See U.S. Pat. No. 5,665,240 issued Sep. 9, 1997 to Hong for "Point-of-Use Removal of Lead in Drinking Water Using Phosphate and Carbonate Minerals." Use of hydroxyapatite or a calcium depleted hydroxyapatite for immobilization of heavy metals in toxic waste materials has been disclosed. See U.S. Pat. No. 5,678,233 issued Oct. 14, 1997 to Brown for "Method of Immobilizing Toxic or Radioactive Inorganic Wastes and Associated Products." Hydroxyapatite has also been disclosed as useful or the removal of heavy metals from aqueous brine. See U.S. Pat. No. 5,681,447 issued Oct. 28, 1997 to Maycock, et al. for "Removal of Trace Metal and Metalloid Species from Brine."
Although hydroxyapatite materials have been known to be able to remove certain heavy metal ions from solution, their efficiency in doing so in view of their cost has precluded their use in many applications. A process using a less expensive, more efficient material is therefore needed.
SUMMARY OF THE INVENTION
A method for removing a selected heavy metal ion from an aqueous solution is provided herein. Said method comprises contacting the solution with collophane at a pH effective for capture of the selected heavy metal ion by the collophane.
Collophane (also called collophanite) is a massive, cryptocrystalline calcium phosphate constituting the bulk of phosphate rock and fossil bone. In physical appearance it is usually dense and massive with a concretionary or colloform structure. It is chemically similar to apatite but compared with commercially available conventional apatite particles in the same size range (-147+104μ) the collophane has a specific surface area of 10.85 square meters per gram compared to 0.7 for apatite. Collophane is a naturally-occurring mineral which is usually impure, containing small amounts of calcium carbonate. It is an important constituent of the rock phosphorite or phosphate rock. Bone is calcium phosphate and large bodies of phosphorite are derived from the accumulation of animal remains as well as from chemical precipitation from seawater. Commercial deposits of phosphorite are found in northern France, Belgium, Spain, and especially in northern Africa in Tunisia, Algeria and Morocco. In the United States, high-grade phosphate deposits are found in Tennessee and Wyoming, Utah and Idaho, as well as the Atlantic Coast and Florida. It is a principal component of many fertilizers. Collophane is much less expensive than apatite, and is commercially available as of the time of this writing at about one cent per pound. Surprisingly, applicants have found it to be significantly more efficient than conventional apatite for removal of heavy metal ions from solution.
Collophane may be used as it occurs naturally, without removal of typical impurities. It may also be used without screening; however, to optimize the methods of this invention it may be desired to use only the smaller size fractions, e.g. less than about 1 mm, and preferably less than about 833 microns.
Heavy metals include antimony, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, uranium and zinc. Preferably the heavy metal ion removed from solution is Sb 2+ , As 3+ , Cd 2+ , Cr 3+ , Co 2+ , Cu 2+ , Fe 3+ , Pb 2+ , Mn 2+ , Hg 2+ , UO 2 2+ or Zn 2+ . A preferred class of such ions includes Cd 2+ , Cu 2+ , Fe 3+ , Pb 2+ , Hg 2+ , and Zn 2+ . A further preferred class of heavy metal ions includes Fe 3+ , Pb 2+ , and Hg 2+ . Uranium (UO 2 2+ ) is also a preferred heavy metal ion for practicing the process of this invention. Arsenic (As 3+ ) and iron (Fe 3+ ) also form a preferred class of heavy metal ions for practicing the process of this invention. It has been found that the presence of ferric ions in solution with arsenic at at least about a 1:1 weight ratio, and preferably greater, e.g. about a 5:1 weight ratio of ferric to arsenic ions, allows for the removal of arsenic from solution. One or more heavy metal ions may be selected for removal in a particular process.
The process is pH-sensitive, with removal of certain heavy metal ions (e.g. lead (Pb 2+ ), iron (Fe 3+ ), arsenic (As 3+ ) and mercury (Hg 2+ )), being favored at low pH (3.5 or less), and removal of certain other heavy metal ions (e.g. copper (Cu 2+ ), cadmium (Cd 2+ ), uranium (UO 2 2+ ) and zinc (Zn 2+ )) being favored at neutral to slightly acidic pH (above 3.5 to 7). Selective capture of desired heavy metal ions may therefore be achieved by varying pH and/or other conditions in accordance with the teachings hereof to favor removal of the desired ions.
At low pH, e.g., about 2.5, using a solution containing a first selected heavy metal ion such as iron (Fe 3+ ) and a second unselected heavy metal ion such as uranium (UO 2 2+ ), iron would be selectively removed from solution, leaving uranium in solution. Selective removal means that a higher proportion of the selected heavy metal ion(s) is removed than the second unselected heavy metal ion(s). Such selective removal processes can be repeated to achieve separation of the selected and unselected heavy metal ions to desired levels.
Solutions containing mixtures of several different heavy metal ions can be treated for selective removal of selected ions by adjusting pH and other conditions as taught below. For example, at pH 3.5, in a solution containing lead (Pb 2+ ), iron (Fe 3+ ), arsenic (As 3+ ), mercury (Hg 2+ ), copper (Cu 2+ ), cadmium (Cd 2+ ), uranium (UO 2 2+ ), and zinc (Zn 2+ ), the first four ions will be preferentially removed, and proportionally more of the remaining ions will remain in solution. Finer separations may be achieved by further pH adjustments in accordance with the teachings hereof.
Uranium (UO 2 2+ ) is best removed at pH about 4-6.5, preferably about 5-6. A selective removal of uranium (UO 2 2+ ) as a selected heavy metal ion from solutions containing other heavy metal ions can be performed at pH about 6.5 to maximize uranium removal and inhibit removal of other heavy metal ions.
Selective capture of desired heavy metal ions may therefore be achieved by varying pH and other conditions in accordance with the teachings hereof to favor removal of the desired ions and leave other heavy metal ions whose removal is inhibited under such conditions in solution.
As shown in more detail below, removal of selected heavy metal ions may occur over a wide or relatively narrow pH range, depending on the ion. A pH effective for removal of a particular ion is one at which measurable removal occurs. Preferably, the amount of ion removed by the process of this invention will be sufficient to achieve the purposes for which the process is being carried out, e.g. removal to a particular environmentally or economically mandated level. In some instances maximization of removal will be desired, and in some embodiments removal down to environmentally mandated levels is preferably obtained. In other embodiments, it may only be necessary to remove a small fraction of the heavy metal ions present.
The solutions useful for the present process may contain large amounts of other impurities and be highly acidic or alkaline. pH adjustment may be necessary as taught herein; however, in general no pre-treatment of such solutions to remove impurities is required. Aqueous solutions suitable for use in this invention include leaching solutions and drainage solutions from mining operations, water supplies, slurries containing high concentrations of solids, bio-oxidation solutions from processes for gold or copper recovery, and any other solutions containing heavy metal ions whose removal is desired.
The process may be conducted by contacting the solution containing heavy metal ions with collophane in any way known to the art. For example, collophane may be added to such a solution, and the solution agitated or stirred. The solution may be essentially free of solids or may contain large concentrations of solids. For example, toxic heavy metals may be immobilized on solid wastes by wetting the wastes with a small amount of water or aqueous solution and mixing collophane therewith. Or solutions containing heavy metal ions may be trickled through a bed of collophane.
After removal of the heavy metal ions on the collophane, the collophane may be disposed of or, in the case of valuable ions, such may be recovered from the collophane by means known to the art.
Capture of the heavy metal ion by the collophane may occur by absorption, adsorption, ion exchange or any other mechanism known to the art. Capture of the heavy metal ion by collophane means removal of the heavy metal ion from solution. The term "attenuation" is also used herein to mean removal of the heavy metal ion from solution.
DETAILED DESCRIPTION
Collophane has been found to be an effective agent for removing heavy metal ions from solution. It has been found to be significantly more effective than hydroxyapatite. The pH of the solution may require adjustment as taught herein or as will be readily ascertainable to those skilled in the art without undue experimentation to effect the removal of selected ions. No heating is required. Generally about one to three hours of contact of the aqueous solution with the collophane is sufficient to achieve substantial removal of the selected heavy metal ion although, as taught below, longer periods of time, e.g., up to 24 hours or longer, may be useful. Over 90% removal of heavy metal ions is generally achievable. Parameters such as pH, conditioning time, collophane particle size and initial heavy metal ion concentration (or ratio of collophane to solution) should be optimized in accordance with the teachings hereof to achieve maximum heavy metal ion removal from solution. Reagents used for pH adjustment can be any reagents know to the art for this purpose; however, in some applications, it may not be desirable to precipitate the heavy metal ion as a salt of the reagent used, and reagents not forming precipitants with the heavy metal ions should be selected. For example, in bioleaching solutions, ferric ion may be precipitated as ferric hydroxide when calcium oxide is used for pH adjustment, which may be undesirable in downstream processing operations.
Although any collophane may be used in the processes of this invention, in general, collophane of lower particle sizes are preferred, e.g. about 833 microns or less. The amount of collophane required will depend on the concentration of heavy metal ion in the solution as will be appreciated by those skilled in the art; however about one gram of collophane has generally been found sufficient for the treatment of about 100 ml of solution, depending on the concentration of heavy metal ion in the solution. The attenuation capacity of collophane varies with the type of heavy metal ion removed, as is taught below and as will be readily ascertainable by those skilled in the art without undue experimentation.
The collophane may be added to the solution, preferably with continuous agitation during the period of contact, and separated from the solution after removal of heavy metal ions by means known to the art, e.g. centrifugation. Alternatively, the solution can be passed through a column of collophane. With ores that have been bioleached, for example, the collophane can be mixed with leached ore and introduced into a unit for solid/liquid separation, e.g., a thickener. Alernatively, the collophane can be combined with the ore prior to bioleaching.
It has been found that lead (Pb +2 ) is most effectively removed from solution at low pH, i.e. over 90% removal, at pH values of about 2.5 to about 3.5, with better removal observed at pH 2.5 after one hour of contact; however, removals up to 99% are possible using three hours of contact time at higher pH, i.e., about 3.5. One gram of collophane per 100 ml of solution was found to be effective for treatment of solutions having concentrations up to about 2,600 mg/l of lead. In packed column experiments collophane was found to have an attenuation capacity for Pb +2 of over 350 mg/g up to about 600 mg/g.
Iron (Fe +3 ) is best removed at low pH, i.e. less than about 3. Better than 90% attenuation can be achieved. Further optimization experiments with bioleaching solutions, which have initial pH's below about 2, i.e., about 1.9, showed complete adsorption of ferric ion from solution after two hours contact with 5.0 g collophane in 75 ml de-ionized water containing 200 g wet ore. Attenuation is essentially independent of solids concentration of ore in the solution. Removal of ferric ion is more efficient than removal of ferrous ion.
Arsenic (As 3+ ) can also be removed from solutions using collophane at low pH, e.g. around 2; however the presence of ferric ion appears to be necessary, and long contact times, e.g. about 24 hours, are recommended.
Mercury (Hg 2+ ) is also most effectively removed at low pH, e.g. around 2-6, and preferably about 3. Greater than 90% attenuation has been achieved, with residual mercury concentrations less than 1 ppm and down to less than about 0.05 ppm.
Copper (Cu 2+ ) was found to be effectively removed from solutions down to 0.9 ppm (starting with a concentration of 8.3 ppm) at pH 6, achieving close to 90% attenuation, i.e 89.2%.
Cadmium (Cd +2 ) has also been removed from solution at better than 90% attenuation. Best removal is achieved at pH greater than about 4.5, preferably about 6.5 and initial concentration less than about 5.5 ppm using one hour of conditioning time.
Uranium (UO 2 2+ ), has been found to be effectively removed from solution at neutral to slightly acidic conditions, i.e. about 3.5 to about 7. Uranium was removed down to a concentration of 18.7 ppb using two grams of collophane per 100 ml of solution having an initial concentration of uranium of 70 ppm at pH 6.5.
Zinc (Zn 2+ ) was also effectively removed to greater than 90% attenuation at around neutral pH, although removal also occurs down to pH about 4. Best percent attenuation was obtained using solutions having low, e.g. less than about 25 ppm, concentrations.
The methods of this invention can be used for separation of heavy metal ions in solutions by varying conditions to favor removal of a selected heavy metal ion and inhibit removal of a second heavy metal ion. For example, using low pH, e.g. about 3.5 or less, allows selective removal of heavy metal ions requiring low pH for best removal, e.g., lead (Pb 2+ ), iron (Fe 3+ ), arsenic (As 3+ ) and mercury (Hg 2+ ), from solutions which also contain heavy metal ions requiring higher pH, copper (Cu 2+ ), cadmium (Cd 2+ ), uranium (UO 2 2+ ), and zinc (Zn 2+ ). In addition, uranium ions can be separated from many other heavy metals by further raising the pH to around 6.5.
EXAMPLES
Experiments were conducted by placing a specified amount of collophane (commercially available calcium fluorophosphate from Florida) in 100 ml of aqueous solution containing the specified initial metal ion concentrations at the specified pH. The pH was adjusted with either NaOH or HNO 3 , and the temperature was controlled at 23° C. The suspensions were stirred for the stated amount of time, after which the solids were separated from their respective solutions by centrifuging at 5000 rpm for 6 minutes. The metal ion concentrations in the separated solutions were then determined analytically.
Example 1
Attenuation of Lead.
Lead acetate was used as the source of Pb 2+ for the experimental work. The parameters investigated were:
1. Effect of pH;
2. Effect of conditioning time;
3. Effect of collophane size; and
4. Effect of Pb 2+ concentration.
System 1. Effect of pH
The effect that pH exhibits was examined and values of pH were varied from 2.5 to 5.5. As the results presented in Table 1 show, effective remediation of Pb 2+ occurs only in quite acid conditions. About 93% attenuation was attained at pH 2.5. Attenuation is achieved by the ion exchange of Pb 2+ for Ca 2+ .
TABLE 1______________________________________The Effect of pHConditions: 1 g collophane (-104 + 74μ); initial lead concentration:796 mg/l; 100 ml solution; 1 hour conditioning time. ResidualInitial Conc. Conc. of Pb, Attenuated Pb, Attenuation,pH of Pb, ppm ppm mg/g %______________________________________2.5 796 57 73.9 92.83.5 796 302 52.6 63.54.5 796 590 20.6 25.95.5 796 528 26.8 33.7______________________________________
System 2. Effect of conditioning time.
The effect that conditioning time has on attenuation was also investigated. See Table 2. For this series of experiments, an initia Pb 2+ concentration of about 800 mg/l and pH 3.5 were selected. As the conditioning time is increased, the attenuation of Pb 2+ was increased. After three hours of conditioning, about 99% of the Pb 2+ was removed from solution.
TABLE 2______________________________________Effect of conditioning time.Conditions: 1 g collophane (-104 + 74μ); initial lead concentration:828 mg/l 100 ml solution; pH 3.5Conditioning Initial Conc. Residual Attenuated Pb AttenuationTime, min mg/l Conc. mg/l mg/g %______________________________________15 828 445 38.3 46.330 828 435 39.3 47.560 828 302 52.6 63.5120 828 78 75.0 90.6180 828 11 81.7 98.7______________________________________
System 3. Effect of particle size.
The effect of particle size was examined with Pb 2+ attenuation experiments. As shown in Table 3, attenuation is essentially independent of size of collophane within the size range, -833+74μ. When the collophane is coarser than 833μ, however, attenuation is reduced.
TABLE 3______________________________________The effect of size of collophane.Conditions: 1 g collophane; 100 ml of solution;3 hour conditioning time; pH 2.5. Initial Conc. Residual Attenuated Pb AttenuationSize microns mg/l Conc. mg/l mg/g %______________________________________-1651 + 833 1595 1446 14.9 9.3-833 + 295 1772 33.5 173.8 98.1-295 + 147 1772 42.0 173.0 97.6-147 + 105 1772 42.0 173.0 97.6-104 + 74 1772 45.5 172.6 97.4______________________________________
System 4. Effect of Pb 2+ concentration.
The concentration of Pb 2+ was varied from 758 to 3,111 mg/l at pH 2.5. About 98% of the Pb 2+ was attenuated up to about 2,600 mg/l which is shown in Table 4. Above about 2,800 mg/l Pb 2+ , attenuation was noted to decrease under these conditions.
TABLE 4______________________________________Effect of Pb.sup.2+ concentration.Conditions: 1 g collophane (-104 + 74μ); 100 ml solution3 hour conditioning time; pH 2.5. Residual Conc. Attenuated PbInitial Conc. mg/l mg/l mg/g Attenuation %______________________________________ 758 22.5 73.5 97.01313 22.4 129.0 98.21772 42.0 173.0 97.61929 22.0 190.7 98.82583 38.8 254.4 98.52822 446 237.6 84.43050 872 217.8 71.43111 833 227.8 73.2______________________________________
Column as a plug flow reactor.
A column was set up, 66 cm high, 0.91 cm 2 cross section area; 70.0 gram collophane (-833+295μ) 30.0 cm 3 vacancy, initial Pb 2+ concentration 640 ppm; pH 2.5; flow rate 1.46 cm 3 /min; calculated contact time 20.5 min.
When the initial Pb 2+ concentration was 640 ppm, a Pb 2+ attenuation capacity of 365 mg/g of collophane was obtained, and the Pb 2+ concentration of the effluent was 0.3 ppm. With a prolonged time, a capacity of 575 mg/g was achieved with a Pb 2+ ion concentration of about 4 ppm in the effluent.
Example 2
Attenuation of Cadmium.
Adsorption experiments were conducted with cadmium nitrate as a function of pH and cadmium (Cd 2+ ) concentration.
System 1. Effect of pH.
TABLE 5______________________________________Attenuation of Cd.sup.2+Conditions: 1 g collophane (-147 + 104μ); initial cadmiumconcentration: 120 ml solution; 1 hour conditioning time. Residual Conc. of Cd,pH ppm Attenuation %______________________________________2.0 81 334.5 60 505.5 58 526.5 57 53______________________________________
Attenuation of cadmium ion is effected with collophane, especially when the pH is greater than about 4.5
System 2. Effect of initial concentration.
1 gram collophane (-147+104μ); 100 cm 3 solution; 1 hour conditioning time; pH 5.5.
TABLE 6______________________________________ Residual Conc. of Cd,Initial Conc. of Cd, ppm ppm Attenuation %______________________________________0.22 0.005 97.70.55 0.012 96.81.1 0.038 96.72.2 0.076 96.55.5 0.45 91.810 1.4 86.027 7 74.962 32 48.486 33 61.6102 36 64.7______________________________________
Greater than 90% attenuation was obtained when the initial concentration of cadmium was lower than 5-10 ppm, at pH 5.5.
Example 3
Attenuation of Iron.
Experiments were conducted to establish the extent of attenuation of Fe 3+ by collophane.
System 1.
Initial concentration of ferric sulfate 560 ppm; 1 gram of collophane; 100 cm 3 solution; 2 hours conditioning time.
TABLE 7______________________________________ ResidualInitial Conc. of Conc. of Fe.sup.3+, AttenuatedpH Fe.sup.3+, ppm ppm Fe.sup.3+, mg/g Attenuation %______________________________________1.8 560 52 50.8 90.32.3 560 62 49.8 88.9______________________________________
Collophane attenuates Fe 3+ very effectively in acid medium, preferably below about pH 3.
System 2. Hydrometallurgical Solution.
Initial pH 1.15; solution contained 7.4 g Fe 3+ /1 and 2.7 g Ni/1; 2 gram collophane (-147+104μ); 1 hour conditioning time; CaO used a pH modifier; attenuation experiments conducted at pH 1.8.
TABLE 8______________________________________ Residual Conc. of Residual Conc. of Attenuation of Fe.sup.3+, g/l Ni, g/l Fe.sup.3+, %______________________________________Collophane 2.2 2.6 70.3Blank (without 4.2 2.7 43.2collophane)______________________________________
Collophane attenuates about 70% of Fe from this solution at pH 1.8 with very little or no attenuation of Ni. A capacity of about 100 mg Fe/g collophane (referring to the blank) was established.
Example 4
Attenuation of Uranium.
Collophane is an excellent adsorbent of dissolved uranium; two systems have been studied.
System 1.
Standard solution (Aldrich Chemical Company); uranium concentration was 70 ppm; 1 gram collophane (-147+104μ); 100 cm 3 solution; 1 hour conditioning time.
TABLE 9______________________________________pH Residual Conc. of U, ppm Attenuation of U, %______________________________________3.0 10.9 84.34.0 0.3 99.65.0 0.2 99.76.0 0.1 99.8______________________________________
System 2. Uranium contaminated soil leached with sodium carbonate.
In another series of experiments a uranium-contaminated soil was leached with sodium carbonate. For the remediation experiments, the initial uranium concentration was 4.3 mg/l, and the pH was 9.5. These results are shown in Table 10; as shown, no attenuation was achieved at pH 9.5 whereas essentially complete attenuation was experienced at pH 6.5. When two grams of collophane were used with a conditioning time of three hours with a solution containing the same concentration of uranium at pH 6.5, a residual uranium concentration of 18.7 ppb was measured.
TABLE 10______________________________________pH Residual Conc. of U, ppm Attenuation of U, %______________________________________9.5 4.3 08.5 4.2 2.37.5 3.1 27.96.5 0.1 97.6______________________________________
Example 5
Attenuation of Mercury.
Attenuation experiments were conducted with mercuric nitrate as a function of concentration and pH.
System 1.
Attenuation experiments were conducted with mercuric nitrate as a function of pH. The initial Hg 2+ concentration was 42.8 mg/l. Optimal pH for adsorption and attenuation was found to be about pH 3.0. See Table 11.
TABLE 11______________________________________Attenuation of mercury.Conditions: 1 g collophane (-147 + 104μ); initial mercuryconcentration: 42.8 mg/l 100 ml solution; 1 hour conditioning time Residual Conc. of Hg,pH ppm Attenuation of Hg, %______________________________________2.0 18.1 57.72.5 9.8 77.13.0 5.1 88.14.0 13.9 67.55.0 23.5 45.16.0 29.4 31.3______________________________________
System 2.
pH 3.0; 1 gram collophane; 100 cm 3 solution; 1 hour conditioning time.
TABLE 12______________________________________ Residual Conc. of Hg,Initial Conc. of Hg, ppm ppm Attenuation of Hg, %______________________________________0.54 0.042 92.21.1 0.087 92.12.2 0.24 89.14.3 2.7 37.210.7 4.3 59.221.4 7.0 67.234.2 7.3 78.851.4 8.2 74.9______________________________________
Attenuation of Hg 2+ is obtained from pH 2 to 6. Preferabiy pH is about 3.0.
Example 6
Attenuation of Zinc.
Attenuation experiments were conducted with zinc nitrate as a function of concentration and pH.
System 1.
Attenuation experiments were conducted with zinc nitrate as a functon of concentration and pH. Very little attenuation was experienced in acid medium, but about 70% of the Zn 2+ was attenuated at pH 7.0 (Table 13). With lower Zn 2+ concentrations, e.g., 10 to 20 mg/l, about 90% attenuation was achieved.
TABLE 13______________________________________Attenuation of Zn.sup.2+.Conditions: 1 g collophane (-147 + 104μ); initial zinc concentraiton:80 mg/l; 100 ml solution; 1 hour conditioning time. Residual Conc. of Zn,pH ppm Attenuation of Zn, %______________________________________4.0 79.6 5.05.0 69.5 13.16.0 57.6 28.07.0 22.8 71.5______________________________________
System 2.
pH 7.0; 1 gram collophane; 100 cm 3 solution; 1 hour conditioning time.
TABLE 14______________________________________ Residual Conc. of Zn,Initial Conc. of Zn, ppm ppm Attenuation of Zn, %______________________________________11 0.6 94.422 1.7 92.345 15.2 66.267 20.7 69.180 22.8 71.5______________________________________
Zinc ion is attenuated about pH 4. The preferred pH for attenuation is about pH 7.0.
Example 7
Attenuation of Copper.
Experiments on the attenuation of copper were conducted with cupric sulfate. The results indicate that when the initial concentration of Cu 2+ was 25.6 ppm at pH 6.0 (calculated concentration was 8.3 ppm because the solubility product of Cu(OH) 2 is 1.3×10 -20 ), the residual concentration of Cu 2+ was 0.9 ppm. Attenuation of copper was 89.2%.
Example 8
Removal of Ferric Ion from Bio-oxidized ore.
About 55 pounds of bio-oxidized gold ore was provided. The size distribution of 1000 g of wet ore was determined after 15 minutes of screening. See Table 15.
TABLE 15______________________________________Size distribution of wet ore.Size (mm) Wet Weight (g) Percent (%)______________________________________+18.85 185.73 18.65-18.85 + 12.50 245.65 24.67-12.50 + 8.00 231.54 23.25-8.00 + 3.35 14.22 1.43 -3.35 14.22 1.43Total 995.74 100.00______________________________________
The wet ore of different size ranges was dried to determine moisture content. These results are shown in Table 16.
TABLE 16______________________________________Moisture content of wet ore. Moisture ContentSize (mm) Wet Weight (g) Dry Weight (g) (%)______________________________________+18.85 185.73 181.69 2.18-18.85 + 12.50 245.65 235.02 4.33-12.50 + 8.00 231.54 219.87 5.04 -8.00 332.82 311.06 6.54Total 995.74 947.64 4.83______________________________________
Wet ore, -12.50 mm in size, was selected for further experiments, since its weight percentage is about 55%, and its moisture content is about 6.0%.
1. Effect of Adsorption Time.
200 g of wet ore and 75 ml of de-ionized water were placed into a plastic bottle. Then, 5.0 g of collophane (-104+74μ) was added, and the bottle was turned for predetermined times. Initial Fe 3+ concentration was 5.0 g/L. Thee results are presented in Table 17. As shown, essentially complete adsorption is effected after two hours of contact under these conditions.
TABLE 17______________________________________Effect of adsorption time.Conditions: 200 g wet ore (-12.5 mm); 75 ml de-ionized water;collophane (-106 + 75μ). Residual Conc. of Fe.sup.3+Collophane Amount (g) (g/l) Attenuation (%)______________________________________0 4.97 01.0 1.9 61.82.0 0.01 99.83.0 0.01 99.85.0 0.00 100.0______________________________________
3. Effect of Solids Concentration.
Solids concentration was also examined in the presence of 1.0 g collophane (Table 18). As presented in Table 18, attenuation is essentially independent of solids concentration.
TABLE 18______________________________________Effect of solids concentration.Conditions: 200 g wet ore (-12.5 mm); 1.0 g collophane (-106 + 75μ);24 hours conditioning time. Initial Fe.sup.3+ Conc. Residual Conc.Solids Conc. (%) (g/l)* (g/l) Attenuation (%)______________________________________19.74 0.53 0.19 64.240.00 1.44 0.53 63.268.72 4.97 1.90 61.8______________________________________ *Determined with waterwash of solids.
Example 9
Adsorption of Arsenic on Collophane.
1. Bio-oxidized Ore.
200 g of wet ore and 75 ml of de-ionized water were placed into a plastic bottle. Then 5.0 g of collophane (-104+74μ) was added, and the bottle was turned for 24 hours. Initial arsenic concentration was 119.35 mg/L. The residual solution contained 1.08 mg/l arsenic.
2. Arsenate Solution.
TABLE 19______________________________________Effect of Fe.sup.3+ on adsorption of arsenate onto collophane.Conditions: pH 2.00; initial concentration of As 105.60 ppm;5.0 g collophane; 100 ml solutiondifferent amount of Fe.sub.2 (SO.sub.4).sub.3 ; agitation for 24 hours.Fe.sup.3+ Conc. (ppm) As Conc. (ppm) Attenuation (%)______________________________________ 0 106.68 0100 101.3 4.07500 89.74 15.02______________________________________
Example 10
Comparison Between Collophane and Apatite.
A comparison of the attenuation obtained with collophane and with naturally occurring apatite has been conducted using 1 g of mineral (-104+74μ); 100 ml solution; 1 hour conditioning time; 24° C. The specific surface areas of the two materials were measured; collophane has about 1,000 times more surface area than apatite.
1. At pH 5.0, 1 g of apatite attenuated about 50 percent of the dissolved uranium. One g of collophane attenuated 99.7 percent of the dissolved uranium.
2. At pH 2.5, 1 g of apatite attenuated about 75 percent of the dissolved lead. One g of collophane attenuated about 95 percent of the dissolved lead.
3. At pH 2.3, 1 g of apatite attenuated about 10 percent of the dissolved ferric ion. One g of collophane attenuated about 90 percent of the dissolved iron.
TABLE 20______________________________________Comparison of Collophane with Apatite______________________________________ Specific SurfaceMineral Deposit Size, μ Area M.sup.2 /g______________________________________Apatite Canada -147 + 104 0.17Collophane Florida -147 + 104 10.85______________________________________Element Result Apatite Collophane______________________________________Uranium Initial Conc., ppm 70 70(pH 5.0) Residual Conc., 32.5 0.2 ppm Attenuation, % 53.6 99.7Lead Initial Conc., ppm 656 656(pH 2.5) Residual Conc., 174.7 35.0 ppm Attenuation, % 73.4 94.7Iron Initial Conc., ppm 488 488(pH 2.3) Residual Conc., 450 52 ppm Attenuation, % 7.8 89.3______________________________________
The preceding examples are set forth to illustrate the principles of the invention, and specific embodiments of operation of the invention. The examples are not intended to limit the scope of the method. Additional embodiments and advantages within the scope of the claimed invention will be apparent to one of ordinary skill in the art.
|
A method for removing a selected heavy metal ion from an aqueous solution is provided herein. Said method comprises contacting the solution with collophane at a pH effective for capture of the selected heavy metal ion by the collophane. Heavy metal ions include Sb 2+ , As 3+ , Cd 2+ , Cr 3+ , Co 2+ , Cu 2+ , Fe 3+ , Pb 2+ , Mn 2+ , Hg 2 +, UO 2 2+ or Zn 2+ , preferably Fe 3+ , Pb 2+ , and Hg 2+ , As 3+ and UO 2 2+ . The process is pH-sensitive and selective removal of desired heavy metal ions may be achieved by varying pH and other conditions to favor removal of the desired ions and leave other heavy metal ions whose removal is inhibited under such conditions in solution. Aqueous solutions suitable for use in this invention include leaching solutions and drainage solutions from mining operations, water supplies, slurries containing high concentrations of solids, bio-oxidation solutions from processes for gold or copper recovery, and any other solutions containing heavy metal ions whose removal is desired.
| 2
|
FIELD OF THE INVENTION
[0001] This invention relates to communication systems, and in particular to a system and method for providing a visual indication of a radio communication directed to a unique identified vehicle. This system and method having particular utility in aircraft and ground test equipment.
BACKGROUND ART
[0002] The air space is a busy place, especially near airports or other landing strips, for both pilots and air-traffic controllers. As the air traffic becomes increasingly populated, controllers must efficiently and systematically give instructions via radio to pilots in that heavily populated air space. Similarly, pilots rely on the radio transmissions from the air traffic controllers as a means of increasing safety.
[0003] There may be many reasons why a pilot might not clearly receive radio instructions from air traffic controllers such as workload, cockpit noise, weather, other closely spaced aircraft, or any number of other reasons. If the pilot-air traffic controller communications routine is disrupted because a pilot missed a radio instruction, then multiple errors can occur. Not only are there delays because the controller has to repeat his instructions, but other aircraft are vulnerable because that one pilot did not receive instructions in a timely fashion.
[0004] Many inventions have addressed this and similar problems. For instance, U.S. Pat. No. 4,369,425 to Anderson et al. teaches a pilot unique transmission radio frequency signal to communicate with the air traffic controllers. The prior art also describes various methods of warning pilots of faulty conditions. U.S. Pat. No. 2,259,123 to Wells et al described a complex system for aircraft instrumentation where a unitary panel of lights would show at a glance, all the aircraft instruments status. U.S. Pat. No. 2,337,535 to Acs Jr., describes a visual warning system activated by an abnormal condition in the aircraft instrument panel. In U.S. Pat. No. 3,582,949 to Forst, discloses an audiovisual warning system activated as a result of a monitored condition in fault. Unfortunately, none of the prior art has sought to exploit the idea of a redundant visual indication to uniquely identify a transmission from air traffic controllers to a given aircraft.
[0005] There have been various in home applications of audio signals driving a visual indication. In U.S. Pat. No. 3,798,638 to Goldschmied, an audio responsive display where the lights are modulated to the audio signal is described. In U.S. Pat. No. 3,890,381 to Hopkins, a system for energizing a lamp upon receipt of predetermined acoustic signals such as telephones or alarm clocks is described. These systems employ fixed circuits that cannot be programmed or changed without physically adjusting the receiving circuit components.
SUMMARY OF THE INVENTION
[0006] Essentially, the prior art does not address let alone sufficiently solve the problem of a pilot missing radio instructions from an air traffic controller. The prior art does not teach the idea of using the pilot unique, existing call sign from the radio output to activate a visual indication which results in a redundant method of notifying a pilot of an air traffic controller instruction. Also, none of the prior art teaches the idea of a programmable call activated system whereby any aircraft can have a qualified person set or change the unique call sign. Additionally, the prior art does not teach the idea that fixed ground test equipment or portable ground test or monitoring systems could also be programmed to be call activated in the same fashion as the aircraft system previously described.
[0007] These and other objects and features of the present invention will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a block diagram of a preferred embodiment of an aircraft visual indicating system;
[0009] [0009]FIGS. 2A and 2B are logic flow diagrams depicting the operation of an aircraft visual indicating system; and
[0010] [0010]FIG. 3 is a block diagram of the call recognition circuit of the aircraft visual indicating system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] While the present invention may be embodied in many different forms, there is shown in the drawings and discussed herein a few specific embodiments with the understanding that the present disclosure is to be considered only as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.
[0012] Modem aircraft utilize a transponder to transmit and receive radio frequency (RF) signals from the ground or control tower. As illustrated by the block diagram in FIG. 1, the aircraft visual is indicating system 100 includes a radio transponder 101 , a transponder audio line 102 , audio output device 103 , mode switching means 108 , audio input device 107 , call recognition circuit 104 and visual display 106 . It is contemplated that the aircraft visual indicating system 100 will use the radio transponder, transponder audio line, and audio output device already found in most modem day aircraft and ground test equipment and consequently be retrofitted thereto. Alternatively, though, 20 the aircraft visual indicating system 100 can be produced as a specific unit including all of the requisite components.
[0013] Radio transponder 101 may be any commercially available radio transponder rated for aircraft use, such as King model KT76C, Terra model TRT250D, Narco model AT-150, Garmin model GTX320, or Rockwell Collins model RTU-4200. Some of these transponders have associated microphones which accept vocal input from the pilots. These transponders are connected by means known by those skilled in the art to an audio panel. The audio panel generally will also house one or more audio output devices such as a speaker and a headset jack. This audio panel may be any audio panel rated for use in commercial aircrafts such as King model KMA-24, Terra model TMA-350D, Apollo model SL1O or Garmin model GMA340. The audio output device can be a speaker, but is commonly a pilot headset.
[0014] Ground test or monitoring equipment such as hand held transceivers or aviation scanners (not shown) would similarly include the radio transponder 101 , the transponder audio line 102 , and audio device 103 shown in FIG. 1. For instance, hand held transceivers currently used in the industry are ICOM model IC-A4 or Communications Specialists model TR70, however, any hand held transceiver may benefit from the advantages provided by the present invention. The aviation scanners used in the industry are Bearcat Aviation Uniden model BC350A or model BC120XLT.
[0015] As shown in FIG. 1, the input of the call recognition circuit 104 is operably connected to the transponder output audio line 102 from the radio transponder 101 . As shown in the preferred embodiment of FIG. 1, audio input device 107 —which preferably comprises a microphone—is operably connected to a second input of call recognition circuit 104 . Alternatively, in embodiments where the radio transponder has an associated audio input device, that input device can be used in place of audio input device 107 .
[0016] Visual display 106 is connected to an output of call recognition circuit 104 . The visual display device may comprise one or more devices known by those skilled in the art that provide a visual indication to a human being, including lamps, LED's, and graphical displays. The visual display may be mounted in a variety of locations. For instance, in aircraft applications, visual display 106 can be located in the cockpit, including incorporating same into the instrument panel, physically attaching it to a pilot's helmet, or incorporating same into a heads up display. In ground test equipment applications, the visual display can be included in the existing package, attached or otherwise physically associated with the test equipment packaging/housing.
[0017] The mode switching means 108 is operably connected to the call recognition circuit 104 and is used to toggle between either a set up or operation mode. As is known in the art, mode switching means can be a mechnical switch, touch switch, computer-controlled status or any other mechanism for selecting between modes.
[0018] The initialization of the system begins by switching to setup mode. Among other possible operations, “setup mode” enables the aircraft's unique call sign (i.e. N721A, WH2238, United 310 Heavy) to be entered and stored in call recognition circuit 104 . In a preferred approach, a qualified person performs this function by reading the call sign into the audio input device. However, it is also contemplated that the call sign could be “keyed in” or selected from a software display pull-down menu (or other graphical means) by using a mouse or similar pointing device. The operation of the system continues by switching to the operation mode where the call recognition circuit monitors the audio line 102 for the correct call sign.
[0019] [0019]FIG. 2A describes the setup mode of call recognition circuit 104 . First, the call recognition circuit prompts (visually or orally) the qualified person (through the audio output device 103 ) to enter the aircraft's specific call sign. The qualified person then “inputs” the correct call sign into the call recognition circuit via audio input device 107 , keyboard, or other user input device. In a preferred embodiment, the call recognition circuit then repeats the prompt sequence (visually or orally) to verify the stored call sign. The qualified person is notified by audio output device 103 , by visual output device 106 , or by a combination of the two that the setup is complete. The qualified person can now change the system mode via mode switching means 108 to the operation mode.
[0020] In the operation mode, as shown in FIG. 2B, call recognition circuit 104 (FIG. 1) listens for a radio transmission that contains a call sign that matches the stored call sign. Once the call sign is detected, an output signal is sent to visual display 106 (shown in FIG. 1).
[0021] The detailed layout of the call recognition circuit 104 (FIG. 1) is shown in FIG. 3. A commercially available speech recognition integrated circuit such as Sensory Circuits, Inc. RSC 164 or Images Company HM 2007 known by those skilled in the art functions as speech recognition circuit 205 . Such a circuit is adaptable to this type of application and information about it is readily available from the manufacturer. The power control switch 207 is used to control power from the power supply 209 to the speech recognition circuit 205 , the audio impedance transformer 203 , and the visual display driver 211 . The audio from the transponder or microphone is connected to the audio impedance transformer 203 which is used to pre-condition the audio signal for the speech recognition circuit 205 . When activated, the speech recognition circuit 205 outputs a signal to the visual display driver 211 which provides signal conditioning and can optionally include a is predetermined time circuit that provides the visual output signal. The time circuit will allow the visual display 106 of FIG. 1 to be illuminated for any desired length of time. In addition, the time the visual indication is provided could alternatively be tied to the vocal response from the user. In particular, if an air traffic controller sends an instruction, including the programmed aircraft call sign, a visual indicator would be activated by call recognition circuit 104 . In response, the pilot confirming receipt of the instruction would repeat the instruction into audio input device along with his call sign. This repetition of the call sign from a local audio source would, in turn, shut off the visual indicator. Similarly, a manual switch, such as a momentary contact switch could be used to shut-off the visual display.
[0022] Referring to FIG. 1, the identification is programmed by entering setup mode as selected by mode switching means 108 by a qualified person who provides the desired call pattern. Once the setup is completed, the mode switching means 108 can be switched to the operation mode. In this mode, the speech recognition circuit 205 of FIG. 3 monitors the audio speech patterns from the radio transponder and audio input device. Detailed operation of the speech recognition circuit 205 can be found in the manufacturer's literature and is readily available. If the transmitted speech pattern matches the desired speech pattern of the stored call sign, then the speech recognition integrated circuit 205 provides an output signal that is sent to visual display 106 of FIG. 1 via the visual display driver 211 of FIG. 3 to warn the pilot of an instruction. In this manner, fewer radio instructions will be missed by the pilot.
[0023] The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto. Those of the skill in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the present invention. For instance, it would be apparent to those of skill in the art having the present specification and claims to incorporate this system into an emergency vehicle, such as a police car and perhaps even utilize the pre-existing emergency lights to indicate receipt of directed radio instruction when the police officers are outside the police car.
|
A system for visually indicating receipt of a radio communication directed to a user having an associated unique identification code. The system includes a radio transponder having an audio output, means for obtaining and storing the unique identification code; a speech recognition circuit operably connected to the radio transponder audio output and the stored identification code; and a visual indicator operably connected to an output of the speech recognition circuit, such that when the stored identification code and said audio input are substantially the same the visual indicator is driven to activation. A method is similarly disclosed.
| 6
|
This application is a continuation application of and claims priority to U.S. patent application Ser. No. 08/511,114, filed Aug. 4, 1995, now U.S. Pat. No. 5,808,625.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of graphics, and more particularly, to the use of dependency graphs for the control and management of the graphics creation process.
2. Related Art
Conventional graphics systems have a plurality of subsystems. These subsystems include, for example, animation, construction history, deformation, and most recently user defined functions. These subsystems, however, all compete for control of certain data and each subsystem is rigidly defined by the structure of the software. FIG. 2 illustrates five subsystems, each of which is connected to communicate with the others. The main drawback of these systems is that they all required complete knowledge of each other in order to operate. As additional subsystems (functions) are added to the system additional connections have to be added. A further problem is that users are never sure how a particular function will react with other functions. As a result, programmers were forced to write code that had to interact with the growing number of subsystems and their own particular quirks. Yet another problem was that the sequential order in which the subsystems executed was rigidly defined by the software.
A prior solution to this problem concentrated solely on the transfer of data. For example, the dataflow method of control has been used for many years in the scientific visualization and image processing domain. However, a more flexible structure is to allow the transfer of information as well (e.g., algorithms or actions).
Thus what is needed is a method of controlling a graphics processing system which includes a plurality of unrelated operations in which information, and not just data, can be transferred between the operations.
SUMMARY OF THE INVENTION
The present invention merges all subsystems within a graphics system into a single control entity. Seamless interaction is accomplished by defining a strongly typed, rigidly enforced interface to a set of dependency nodes. Any dependency node that wants to interact with another dependency node must do so through a connection. The only parts of a dependency node that another node can control must be specified by attributes. In order for connections between attributes to be valid they must use the same type of information. Lastly, dependency nodes may communicate with each other by sending or receiving messages.
The present invention is based on a dependency graph. The term "dependency graph" refers to a set of dependency nodes and the information flowing between the dependency nodes. The dependency graph describes the process that is used, for example, to build an entire scene and display it on a display device. A directed acyclic graph (DAG) is an example of a simplified dependency graph where the connections consist solely of the DAG parenting information. A DAG conceptually captures parenting (or hierarchical) relationships between graphic objects. Scenes are built by travelling from the root dependency nodes to the leaf dependency nodes, accumulating a transformation matrix as the DAG is traversed and applying the transformation matrix to whatever geometry is found in the leaf DAG nodes. The dependency graph extends this by capturing notions of "building" geometry via a modeling function, or deformation (for example). In this way, all of the previously separate subsystems (expressions, deformation, animation, construction history) are brought together and given a well-defined relationship.
A dependency node in the dependency graph represents a means to manipulate information. Data can take two forms: data that lives in a DAG node (e.g., geometry, lights, cameras, etc.) or information that lives in other dependency nodes. Dependency nodes offer a set of parameters to be controlled through the graph. These parameters are called "attributes." A dependency node is meant to be a completely encapsulated object, with only these attributes as connections to the rest of the graph.
Attributes are the parameters on a dependency node that may be controlled through the dependency graph. Attributes have Read/Write permissions associated therewith which indicate what can be done with them. Generally, there is a set of input attributes with read and write permission, and there is a set of output attributes with read permission only. Input attributes are data that the dependency nodes needs to perform their function. Output attributes are data that the dependency node has either created or modified in the course of performing its function. All attributes have a set of predefined data types that they accept. This means that any attribute which outputs the predefined data type may be connected to an attribute that inputs the predefined data type.
The present invention puts a "wrapper" around all data objects (e.g., DAG nodes). The "wrapper" is a window into the dependency graph. The dependency graph and DAG nodes communicate with each other through a client/server notification scheme. Thus, if one changes the other will also change. The "wrapper" is an interface. In order to communicate, dependency nodes must adhere to a predefined protocol.
Dependency nodes' attributes that are connected must exchange the same data type. This is known as strong typing. Each dependency node operates independently of the other dependency nodes. As such, a first dependency node does not know what a second dependency node is doing. This assures that no matter where a dependency node comes from all dependency nodes within the dependency graph will behave similarly. This independence is known as "black box operation."
In a preferred embodiment, the present invention provides a system and method for operating a graphics processing system that includes a plurality of unrelated operations.
Each of the plurality of unrelated operations are wrapped with a node, each node providing an interface for communicating information to and from the operation upon which it is wrapped. Each interface defines at least one node attribute. In response to a user request, a connection is established between a first selected node and a second selected node in accordance with the node attributes of the first and second selected nodes. Further in response to the user request, an operation of said first selected node is performed. Next, information of said second selected node is evaluated based on the connection with the first selected node and in response to an information request from the operation of the first selected node, wherein the operation of the first selected node is provided with the requested information.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.
FIG. 1 illustrates a general hardware environment in which a preferred embodiment of the present invention can operate.
FIG. 2 illustrates a conventional approach to controlling a set of subsystems.
FIG. 3 illustrates an architectural overview of the present invention.
FIG. 4 illustrates the exchange of data between two dependency nodes.
FIG. 5 illustrates the dataflow method.
FIG. 6 is a legend used to define graphical objects that are used in FIGS. 7-12
FIG. 7 illustrates an example of applying the present invention to a REVOLVE operation.
FIG. 8 illustrates an example of applying the present invention to an animating the results of a REVOLVE operation.
FIG. 9 illustrates an application of the present invention to a RENDER operation.
FIG. 10 illustrates an application of the present invention to a Paint/Compositing operation.
FIG. 11 illustrates a collaborative development using the invention to communicate between multiple developers.
FIG. 12 illustrates the creation of dependencies on events and data outside of the graphics creation process.
The preferred embodiment of the invention is now described with reference to the figures where like reference numbers indicate like elements. Also in the figures, the left most digits of each reference number corresponds to the figure in which the reference number is first used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Environment
FIG. 1 illustrates a general hardware environment in which a preferred embodiment of the present invention can operate. The environment 100 of the present invention includes application programs 102a, 102b and 102c. Computer platform 104 includes a hardware unit 112, which includes potentially multiple central processing units (CPUs) 116, a random access memory (RAM) 114, and an input/output interface 118. Computer platform 104 includes an operating system 108. Various peripheral components can be connected to computer platform 104, such as a graphics terminal 126, a data storage device 130, and a printing device 134.
Computer platform 104 is any personal computer, workstation or mainframe computer. In a preferred embodiment, CPU 116 is any processor from the MIPS™ family of processors including R3000. Operating System 108 can be any operating system compatible with computer platform 104. In a preferred embodiment, operation system 108 is the IRIX™ operating system version 5.3 or greater available from Silicon Graphics. IRIX supports an XWindows™ based graphical user interface (GUI) 140.
2.0 Introduction
The dependency graph, hereinafter referred to as "the invention", describes a method of controlling systems including but not limited to all of those involved in the computer graphics content creation process. At a minimum this includes modeling, animation, rendering, compositing, digital paint, and image processing. We claim the invention is suitable for use in not only this minimal set of the content creation process but all other areas that are used to create the final output as well.
2.1 Glossary
This section will define some terms used throughout the rest of this document. In the case that the word has a more common usage the usage described herein should be taken as the intended meaning.
Attribute: A piece of information that a node uses in order to perform its operation. This is information in the abstract sense, (e.g., the statement "I need a banana to perform my operation" is abstract information, as opposed to an actual banana which is data).
Connection: A data pathway between two nodes through which they can pass information. A directed connection restricts the information to only pass in one direction.
Control System: A subsystem dedicated to the control of communication and relationships between other subsystems.
Data: Any type of information that is represented by some concrete object, (e.g., a particular banana would be data but the concept of what a banana is would not).
Dependency: An object A has a dependency on an object B if altering some part of B would affect some part of A.
Evaluation: The process of interpreting data using an algorithm to produce a resulting set of data.
Fan-in: Multiple connections at the same input.
Fan-out: Multiple connections at the same output.
Graph: An arrangement of nodes and connections between them. A graph is taken in the general form where it is not necessary that all nodes have connections (nor all subgraphs be connected together).
Information: Some form of knowledge that flows through the graph. This could be either abstract (algorithms or descriptions) or concrete (data).
Node: An entity in the graph that embodies an operation of some sort.
Subsystem: A particular section of a system that controls unrelated operations that are logically similar.
System: All of the pieces that go into defining how a process (e.g., graphics content creation) works.
Wrapping: The process of creating an external data object that refers to an presents an alternate interface for an internal data object.
3.0 Description
The invention is a method of controlling operations that have dependencies on each other. It can be conceptualized by using a graph where the nodes represent operations and the connections (lines) represent the dependencies.
3.1 Merging Control Systems
In previous approaches there were a collection of subsystems all representing the various phases of graphics content creation (Animation, Model Creation, Model Deformation, etc.). The main drawback to these systems was that they all required complete knowledge of each other in order to operate. In addition, since this knowledge was in actual code, they had to be executed in some hard-wired order according to what the code dictates. Changing the order of application of any system was difficult (e.g., animation of construction history, creating a model and using deformation) and adding new systems as new technology became available was at the point of being prohibitive (e.g., adding motion capture and dynamics simulation). This is shown generally in FIG. 2.
The invention removes the restrictions implicit in this subsystem model by introducing itself as a control system that manages all of the inter-system relationships. This is shown generally in FIG. 3. The dependency graph serves as a "hub" so that independent systems need not know anything about each other. Note that each system contains a set of unrelated operations. As can be seen, there is no limitation placed on the execution order of the individual subsystems. Accordingly, arbitrary, and possibly repetitive execution order allows systems to interact in any way possible.
3.2 Making a Graph
The main job of the invention is to allow independent subsystems to work together without knowledge of each other. In order to accomplish this it establishes itself as the single point of contact between systems. To do this it defines a communication and connection protocol that all systems must adhere to. This ensures that it can not only communicate with them but also interpret and pass on this information to other systems as appropriate.
3.2.1 Nodes
The nodes are the components of the graph that implement the operations that the graph will be performing. In order to enforce the single point of contact all nodes have black-box operation. That is, the only information they are allowed to send/receive to the rest of the world must be presented as attributes of the node. Conversely if a node has the information from all of its input attributes it must be able to produce the information it is presenting at its output attributes.
3.2.2 Attributes
An attribute on a node defines a potential communications channel. These attributes may be input only, output only, or both. An input attribute is defined as an information channel that can only feed information into the node. Similarly an output attribute can only feed information out from the node. The attributes are used to define the "allowable" connections between nodes. They tell the graph what kind of plugs and sockets the node understands.
Attributes are not shown in the diagrams but are assumed to be present at both ends of all connections.
3.2.3 Connections
Given a pair of attributes with compatible plugs/sockets in order to get them to communicate you must wire the plug on the input attribute to the socket on the output attribute. This wiring is referred to as the connection. (Note that since the attribute is merely a description of the plugs available it is entirely possible but not required that more than one connection to the same attribute can be made. This is commonly referred to as fan-in and fan-out.) Connections need not be physical entities, just a method of getting information from one attribute to another.
Connections are drawn as arrows with the flow of information indicated by the direction of the arrow.
3.2.4 Information
If the system described so far is like the plumbing then the information is the water that flows through it. Information travels through the connections between attributes on nodes. Information is exactly as the dictionary defines it: "a report of events or conditions not previously known". This can come in the form of concrete data, like a floating value, or abstract knowledge, like a matrix inversion algorithm. In all cases it is something that a node requires in order to perform its function.
In traditional approaches to the problem of an integrated control system found in any of the dataflow systems is a protocol set up with the limitations that the connection between operations ("nodes") is hard wired and only a specific type of data propagates ("flows") between connected nodes (and only in one direction). The invention removes these restrictions by using a plug-and-socket metaphor to define the available communications channels.
Each node must define the information that it requires ("attributes") in order for it to perform its function, as well as the information that it produces. Information flowing out is like a plug. The legal connections between nodes are any two attributes where the plug type matches the socket type. The plug/socket types are defined by what type of information is required/available for the given attributes. At the highest level three plug types represent abstract information (algorithms/descriptions), concrete information (data), and pure communication. This is like having a North American outlet, a European outlet, and a phone outlet. You cannot plug communications into a data outlet no more that you could plug your home phone into the hydro socket. This strong typing can be broken into as fine or coarse a granularity as is needed for the particular application. The way that it is superior to traditional approaches is that objects can be identical at certain levels of granularity so that more than one type of data can flow across the connection depending on what is being generated.
In addition, since this system is not bound by the limitations of physical objects, information sockets can be defined that accept a variety of different plugs; not necessarily just those that look kind of the same. It is then up to the node to decide what to do with the information that arrives through its sockets.
The above shows how the invention removes the "data only" and "hardwired" restrictions of the data-flow model. Plugs can be arbitrarily removed and inserted into new sockets, so long as they are of compatible type. No concrete data needs flow across these connections; it can be abstract information such as an algorithm to be used in computation, or a description of how to get at the other hidden data (like a file handle for getting data from a file).
The restriction of one-way dataflow is removed by the fact that these connections are communications channels and information can flow in either direction. There will be a usual flow of information from dependees to dependents but there is no restriction on information flowing the opposite way.
Once all nodes are connected in this way the invention controls the flow of information by remembering what connections need evaluation, ensuring the dependee/dependent relationships propagate their information correctly and in a timely manner, and managing all connections and disconnections of nodes within the graph.
3.3 Separate Controller or Integrated System
Although the invention successfully merges many subsystems together into a unified whole it is still desirable for some systems to maintain autonomy outside of graph operations. An example of this is a hierarchical modeling system, commonly known as DAG (Directed Acyclic Graph). Each node in a DAG defines a transformation and the connections define a parenting relationship, creating a very powerful metaphor for the construction and manipulation of computer models, (e.g., a DAG allows you to create a model so that when you move the shoulder the forearm moves with it, but when you move the forearm the shoulder remains still).
The invention does not desire to take away the power. inherent in alternate paradigms such as this, but still needs to integrate their operation with the other subsystems being controlled. (It may also be the case that the system to be integrated is closed in that the invention cannot alter the original in any way and so must make use of it as is.)
In order to solve this the invention uses a wrapping technique. Operations or objects in the separate system are identified at the granularity that they require control (e.g., DAG nodes from a DAG based system) and then dependency graph nodes are created that present the available controls of the object/operation as attributes of the node (e.g., Translate X, Translate Y, Translate Z would be typical attributes of a DAG transformation node). This technique can be used to allow the dependency graph to control any external interface presented by the separate system, while still allowing the seperate system to use its own internal functions to be used normally.
In addition, since typically the separate system may modify things that affect the output attributes, a communication system can be used to detect and propagate any changes that the separate system makes internally.
FIG. 4 illustrates the exchange of data between two dependency nodes: node A and node B. Dependency node A is "wrapped" around a DAG node 230. Dependency node A receives data from dependency node B across communication link 220. When dependency node B changes, it must update dependent node A. In order to achieve this result, dependency node B sends a message to dependency node A stating that "you are dirty" and therefore must update yourself. Dependency node can either ignore this message or respond to this message. When DAG node 230 requests redraw of dependency node A, dependency node A sends an "evaluate me" message to dependency node B. Dependency node B then evaluates and returns results to dependency node A over communication channel 220. Note that dependency node A knows how to control DAG node 230. Thus, when data is returned from dependency node B, dependency node A can pass the data onto DAG node 230.
3.4 Pseudo-Code
This section will describe one possible implementation method for the invention, although many more are possible. A C++-like form of pseudocode is used since that is the first implementation language of the invention.
3.4.1 Defining Nodes
Defining nodes involves at least two main functions. Defining the interface and defining the evaluation.
______________________________________DefineInterface() For each attribute the node is allowed define the attribute add the attribute to the node's list}Evaluate (OutAttr){ if( outAttr is not readable ) quit For each input attribute required to compute OutAttr if( input attribute is connected ) Evaluate input attribute connection and save also save default attribute value Do comparison to find outAttr value Return the value to the calling routine}______________________________________
3.4.2 Making Connections
In order to make a connection two things are required; an input side and an output side. The definition of each side requires an attribute and a node.
______________________________________inAttr= input attribute to be connectedoutAttr= output attribute to be connectedif( information types used by outAttr and inAttr do not match) quitinNode = input node that is to be connectedoutNode = output node that is to be connectedif( inNode is connected to InAttror outNode is connected to outAttr ) (for later use)______________________________________
3.4.3 Evaluation
The evaluation loop occurs entirely through the node's evaluation process. The only other thing required is that the same external (or internal) agent request the value of some node's output. This causes the node to evaluate that output, which in turn (as shown above) causes the node's inputs to be evaluated which themselves cause others to evaluate, and so on.
One addition to this loop, the use of a dirty status, within the connections allows minimal recomputation via a push-pull evaluation model.
______________________________________PUSH<User changes something that invalidates some node data>For each ( output attribute on the node ) if( attribute is connected ) mark the connection as dirty set the connected node to be dirty as well (recurse)PULL<User requests some node evaluation>For each ( output attribute requested to evaluate ) if( attribute is connected .English Pound..English Pound. connection is dirty Evaluation the node at the attribute else Return the current value of the attribute.______________________________________
3.5 Pseudo-Code (Specific Examples)
This section shows some actual node/attribute/connection implementations as a more concrete form of the pseudo-code presented earlier. A C++-like form of pseudo-code is used since that is the first implementation language of the invention.
3.5.1 Data Structures
The format used will be
______________________________________StructureNameFieldName FieldDescription::MethodName (methodParameters) MethodDescription______________________________________
When "StructureName" is the name of the data structure, "FieldName" is the name of one of its components and "FieldDescription" describes the component. "MethodName" is the name of member function that the structure uses. Its parameters "methodParameters" and its operation is described by "MethodDescription." When referred to in the pseudo-code the abbreviation StructureName FieldName will be used to indicate a particular component of a data structure.
______________________________________NodeInputList List of all input connections on this nodeOutputList List of all output connections on this nodeAttributeListList List of all attributes available on this node::create () Constructor::evaluate (Attribute) Evaluates the output attribute and returns the resulting value.AttributeReadable If "true" the attribute can be an outputWritable If "true" the attribute can be an inputInfoType Type of information the attribute expectsConnection Connection to this attribute (if any)::evaluate() Evaluate this attribute (if connected)::connectTo (Attribute) Makes a connection with another attribute. The assumption is that the attribute that calls the method is to be the input side.ConnectionInAttribute Attribute at the connection's input sideOutAttribute Attribute at the connection's output sideInDirty Is the connection currently dirty?InNode Node at the connection's input sideOutNode Node at the connection's output sideInformationId Value to identify the type of informationData Actual data needed to define the information______________________________________
3.5 Node/Attiibute Definition
This section will show how to define some simple types of Node (and the interface to be presented in the graph). First some common code:
______________________________________Attribute ::evaluate() { if( Attribute is Connected .English Pound..English Pound. Attribute isInput return evaluated valtie of output attribute on the output node; }::connectTo(inNode,Other,OutNode) if( InfoType == other:InfoType .English Pound..English Pound. connection is okay with both nodes create new connection add it both attributes}______________________________________
The first operation is ADD which will take as input two floating point numbers and produce their sum as the output.
______________________________________AddNode ::create() { Create Input 1 Attribute(Writable,Float) Create Input 2 Attribute(Writable,Vector) Create Output Attribute (Readable, Float)::evaluate (Attribute){ if( Attribute == Output Attribute ) vector1 = Input 1 Attribute::evaluate() vector2 = Input 2 Attribute::evaluate() return (valuel + value2);}______________________________________
The second operation is DOT -- PRODUCT which will take as input two vectors and produce a floating point number (the inner product of the vectors) as output
______________________________________DotProductNode ::create() { Create Input 1 Attribute(Writable,Vector) Create Input 2 Attribute(Writable,Vector) Create Output Attribute (Readable, Float) } ::evaluate() { if( Attribute == Output Attribute ) vector1 = Input 1 Attribute::evaluate() vector2 = Input 2 Attribute::evaluate() return( DotProduct(vector1, vector2) ); }______________________________________
The third operation creates a Surface of revolution from a Curve and a Float (sweep angle) using an internal operation called::Revolve(Curve,SweepAngle)
______________________________________RevolveNode ::create () { Create Curve Input Attribute(Writable,Curve) Create Sweep Input Attribute(Writable,Float) Create Surface output Attribute (Readable, Surface) } ::evaluate (Attribute) { if( Attribute == Surface Output Attribute ) curve = Curve Input Attribute::evaluate() angle = Sweep Input Attribute::evaluate() return( ::Revolve(curve,angle) ); }______________________________________
3.5.3 Connection
For this example the ADD method will get the sum of two DOT -- PRODUCTS which will feed into the sweep angle of a REVOLVE.
______________________________________Create the two DOT.sub.-- PRODUCT nodesGet the DOT.sub.-- PRODUCT output attributeGet the ADD input 1 attributeConnect the ADD node attribute with the first DOT.sub.-- PRODUCT node's attributeGet the ADD input 2 attributeConnect the ADD node's input 2 attribute with the second DOT.sub.-- PRODUCT node's output attributeGet the ADD output attributeGet the REVOLVE input sweep angle attributeConnect the two attributes______________________________________
All information that flows between attributes in the dependency graph must be wrapped in a class from the information hierarchy. The hierarchy provides a common base class so that information can be at least partially type checked and read/write permissions can be used to allow smart caching of results. There are two types of data in the information classes: lightweight and heavyweight. Lightweight data is anything which is normally passed by value (e.g. double precision, floating point, integer, boolean). Heavyweight data is anything which is normally passed by reference, or which has an expensive copy function (e.g., Surface, Curve, shape). Information classes uses the permission data to determine when copying of the data is necessary and when a reference will suffice. In general, a copy is necessary when the data is read-only and the user wants to write on it.
While the attributes indicate what sorts of information may be connected in the dependency graph, the connections are the actual arcs in the dependency graph which define the information channels that have been created. Connections are split into three parts: the identification of the two actual attributes that are connected and the data that is common to both of them. The former is further broken into derived classes which handle simple attributes, multiple attributes and compound attributes. These derived classes are not usually used explicitly since everything needed for querying the connection sites is available in the base class. Some notable things that the connection classes do are pass on messages from one dependency node to another, retain dirty status for smarter evaluation, perform evaluation (by passing information to the output-side node).
Messaging forms the heart of the graph's communications. Nodes pass messages to each other to indicate that things have changed, that they need evaluation or for any other reason that they might request some work/data from another dependency node. The base node class knows how to handle only the above messages but a major goal of the messaging is to allow anybody to teach any dependency node how to react to a given message. The messages all derive from a common base class which itself is derived from the normal client-server message class. The reason for this second level of indirection is in order to add a unique Id to the message which can be used to detect and avoid loops.
4.0 Improvements on Existing Systems
There are three main types of similar existing control systems which will be addressed separately. The most unique thing about the invention is that it tackles a very broad spectrum of tasks using combinations of old and new methods that were originally meant for very defined and narrow tasks.
4.1 DataFlow
The dataflow method of control has been used for many years in the scientific visualization and image processing domain. It is probably the most similar to the dependency graph system in that it involves creating a graph consisting of data operations as nodes and data pathways as connections.
Referring to FIG. 5, the data pathway takes data from Op1, feeds it through Op2 and Op3 to finish up in Op5. Typically, one of these will be a display node so that the data can be seen by the user. Most applications using this paradigm have been single data types (e.g., in image processing the data type is always "image") or at most a few well defined data types. The dependency graph's notion of data is not restricted in this manner. It can handle as many different types of data as can be created.
The dataflow solution can be thought of as a pipeline through which water (data) "flows". Each node represents an operation on that data, like coloring the water or reducing the volume and so forth. Each operation alters the water in some way but never changes the inherent nature of water; it is still liquid, it still has the same chemical formula (H 2 O), it still occupies space, and so forth.
4.1.1 Strengths
Excellent paradigm for single-data type systems.
This is just a special case for the invention. Single data type means that only one type of plug/socket is available, thus simplifying the connection process.
Linear sequence of operations handled very well.
Again this is just a special case where the invention is restricted to not use fan-in/fan-out.
Can view data at any stage of the pipeline.
The invention allows for this in two ways: first for geometry a DAG node can be inserted in the connection that the data to be viewed is flowing, and second any data can have a "View" node created for it that will take the data as input and pass it on unchanged with the side effect of displaying the data as it passes through.
Operations can be parallelized.
The black box operation of the invention ensures that parallelization of the graph is possible by having the graph dispatch the requests for evaluation to as many processors as it controls.
4.1.2 Shortcomings
Strictly defined data pathways.
The pathways in the invention are just communication channels and they can be rewired at any time. All that is required is the new connections meet the same guidelines for plug/socket matching as the originals.
All information must be available at all connection pipes.
This is caused by the dataflow "view anywhere" ability. For instance in order to view geometry halfway through a pipe all of the display information for the geometry must be available (including shader information, resolution, etc.). By having a separate DAG for display the invention can carry along only as much information as it needs for the operations, keeping the rest in the DAG nodes to be displayed.
Only data can move between nodes.
An obvious shortcoming when trying to define interchangeable algorithms the invention overcomes this by generalizing the definition of communication between nodes from strictly data to "information". The dependency graph allows data which is not an object, but an algorithm. This would be akin to having water travel through the pipe along with the rules for how it behaves. Now a node is free to alter not only the water but also its behavior; for example, a dependency graph node could change data from water to ice, or to rock, or make it more or less viscous, and so forth. Since it is not necessarily "data" that is flowing through a dependency graph it's usage is more general.
4.2 Simulation
Some techniques are in use which make extensions from dataflow similar to those of the dependency graph for the purpose of running simulations (usually some form of physically based modeling/animation). In these systems algorithms and rules of behavior are passed through the graph as in the dependency graph.
There are two main differences in the way the graph is managed in a simulation system. The first is that all animation must run synchronously so the entire graph has the notion of "current time" embedded in it. This makes these systems ineffective for modeling based operations such as construction history, since in the majority of cases modeling operations do not happen over time they simply describe the history of the object's creation.
This is different from "animation history" which describes how you want the object to move through the course of an animation. Construction history is in the past, animation is in the future. The dependency graph uses time not as a special entity but just as another part of the system that nodes may have a special interest in. (This moves the uniqueness of time out of the graph and into the individual implementation-defined nodes.)
The second restriction that simulation systems employ is the fact that all connections must have a well-defined coupling. That is, the simulation requires a certain feedback loop to be implemented in the graph in order for it to iterate to its solutions. If this feedback loop was altered then the simulator would be confused as to how convergence happens since its output may be tampered with to the extent that it never comes close to a solution.
4.2.1 Strengths
Excellent control of physically based events.
The invention allows for the same time-specific operations through the addition of a node in the graph that represents time. This is more general than embedding time into the graph because this time node can be replaced by any other node that supports the same data type (e.g., an expression, a warped time, a real-time clock, etc.).
Can roll time forward/backwards in any increment for collision detection, etc.
As above the invention has full control over time. In addition the communication connections can be used to propagate information to time itself (e.g., to change, to slow down, to speed up, to change increments).
No worries about objects at different times since time is so entrenched.
Again, since time is under full control using the invention this is handled.
Motion of objects entirely defined by simulation algorithm.
If this is the desire then it is a subset of the invention which does not allow any nodes outside of the simulation nodes. While greatly desirable for pure simulation, the more general applications in animation make this a weakness which the invention does not share.
4.2.2 Shortcomings
Hard or impossible to combine simulated/non-simulated controls.
Since the invention does not even know what simulation is the combination of non-simulation based controls is a basic part of the system.
Unsimulated operations (like modeling) don't fit well.
Again since time is only another node in the system modeling operations can safely ignore it and operate in the manner they wish. The invention is particularly well suited to pure modeling operations since the restrictions they require of the invention make it very simple to understand.
Everything typically has its own unique time, leading to confusion.
Every piece of data in the invention has a value, without any notion of time or anything else. So long as the proper data is updated when required there is no confusion about what certain data means.
Arbitrary connectivity causes trouble for the simulator.
Any simulation that is put into the invention will have all of the communication channels available to it, allowing for the possibility of either non-converging simulation or value overrides when multiple controls are present on a single object (i.e., the simulation can either remember where it is iterating to or can be allowed to provide non-unique solutions that are "steered" by the other nodes in the graph).
5.0 Perceived Uses
This section outlines but does not limit some uses for the invention in the field of computer graphics content creation. FIG. 6 is a legend that defines graphical objects used in FIGS. 7-12.
5.1 Modeling
The invention provides a "recipe" for creating the final model by tracing the final result back through all of the dependees that created it.
By "reading" through the connection path we can describe how the surface was created. In the example shown in FIG. 7 the curve goes through a REVOLVE operation to become a surface of revolution, which is then in turn deformed to produce the final output surface.
5.2 Animation
The invention itself has no notion of what time is so it is up to the external application to introduce the concept by introducing a "time" dependency node. A node is said to be "animated" if somewhere along the line it is dependent on the time node. Lets take the REVOLVE example above and assume that the REVOLVE node has a second input attribute representing the sweep angle. We can make this surface create itself over time by controlling the sweep angle with a function of time. This is shown in FIG. 8.
In order to show this animating you only have to change the TIME node. This informs its dependent (FUNCTION) that it needs to evaluate, which informs its dependent (REVOLVE) and so on up to SURFACE. The new surface will be based on the DEFORMed REVOLVEed CURVE with a swept angle equal to the FUNCTION of TIME. Note that all updating happens automatically, requiring no knowledge of how the invention works inside of the nodes or connections.
5.3 Rendering
Referring to FIG. 9, Once a project has an animated model the next thing you typically do with it is render it. Typically this is a separate process with no knowledge of the modeling and animation that went into its creation, however the invention merges these processes so that changing the model can have information sent to the renderer to make it rerender.
5.4 Paint/Compositing
Referring to FIG. 10, painting can occur at any point in the creation process. At the beginning it can be used to sketch out rough models for preliminary animation, in the middle it can be used to paint textures for objects, and at the end it can be used to alter the rendered image. Compositing usually happens at the end but of course the invention makes no restrictions along these lines.
The left hand side of FIG. 10 shows creation and application of a painted texture onto a model. The right hand side of FIG. 10 shows compositing of the rendered image with a painted video output to yield the final image. Now the creators of the renderer, compositor, paint program, and modeler are freed from having to know how their output will affect the next step in the creation process. It is all encoded into the dependencies.
5.5 Project Management
FIG. 10 is an illustration of a high level project management task implemented by the invention. All of the functions of modeling, rendering, painting, and compositing are controlled by the invention. Once again this illustrates the difference between the invention and other similar processes; the invention has not restricted its problem domain in one particular niche task, but rather keeps itself general enough to handle a whole spectrum of tasks.
Another illustration of the possibility of collaborative development using the invention to communicate between multiple developers. This is shown in FIG. 11 Communication nodes which wrap around a file system or even the World Wide Web can be used to notify developers when other developers have changed objects.
5.6 General Purpose
Jumping out further to take in an even larger picture, the invention allows the creation of dependencies on events and data outside of the entire creation process. For example in a typical video game the joystick will control the initiation of certain actions (like move left, right, run, walk, jump, etc.). A dependency graph can be set up between the control joystick) and the animation parameters that it controls. Even though the content has been created the use of the content can be controlled through a dependency graph; and the control itself determines how to react based on a lower level to dependency graph. This is shown in FIG. 12.
In one embodiment, the present invention is a computer program product (such as a floppy disk, compact disk, etc. also referred to as a computer usable medium) comprising a computer readable media having control logic recorded thereon. The control logic, when loaded into memory 114 and executed by the CPU 116, enables the CPU 116 to perform the operations described herein. Accordingly, such control logic represents a controller, since it controls the CPU 116 during execution.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
|
A system and method for merging all subsystems within a graphics system into a single control entity, referred to herein as a dependency graph. The term "dependency graph" refers to a set of dependency nodes and the information flowing between the dependency nodes. Seamless interaction is accomplished by defining a strongly typed, rigidly enforced interface to the set of dependency nodes. Any dependency node that wants to interact with another dependency node must do so through a connection. The only parts of a dependency node that another node can control must be specified by attributes. In order for connections between attributes to be valid they must use the same type of information. Lastly, dependency nodes may communicate with each other by sending or receiving messages.
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 USC 119(e) to U.S. Provisional Applications Ser. No. 61/874,794, 61/874,810, 61/874,856, 61/874,914, 61/874,880, 61/874,889, and 61/874,866, all filed on Sep. 6, 2013, and all of which are incorporated herein by reference.
[0002] This application is related to:
[0003] U.S. patent application Ser. No. ______ entitled “METHOD AND APPARATUS FOR ASYNCHRONOUS PROCESSOR WITH FAST AND SLOW MODE” and filed on the same date herewith, and identified by attorney docket number HUAW07-06583, and which is incorporated herein by reference;
[0004] U.S. patent application Ser. No. ______ entitled “METHOD AND APPARATUS FOR ASYNCHRONOUS PROCESSOR WITH AUXILIARY ASYNCHRONOUS VECTOR PROCESSOR” and filed on the same date herewith, and identified by attorney docket number HUAW07-06502, and which is incorporated herein by reference;
[0005] U.S. patent application Ser. No. ______ entitled “METHOD AND APPARATUS FOR ASYNCHRONOUS PROCESSOR WITH A TOKEN RING BASED PARALLEL PROCESSOR SCHEDULER” and filed on the same date herewith, and identified by attorney docket number HUAW07-06376, and which is incorporated herein by reference;
[0006] U.S. patent application Ser. No. ______ entitled “METHOD AND APPARATUS FOR ASYNCHRONOUS PROCESSOR PIPELINE AND BYPASS PASSING” and filed on the same date herewith, and identified by attorney docket number HUAW07-06364, and which is incorporated herein by reference; and
[0007] U.S. patent application Ser. No. ______ entitled “METHOD AND APPARATUS FOR ASYNCHRONOUS PROCESSOR BASED ON CLOCK DELAY ADJUSTMENT” and filed on the same date herewith, and identified by attorney docket number HUAW07-06351, and which is incorporated herein by reference.
TECHNICAL FIELD
[0008] The present disclosure relates generally to asynchronous circuit technology, and more particularly, to a self-clocked circuit generating a clocking signal using a programmable time period.
BACKGROUND
[0009] High performance synchronous digital processing systems utilize pipelining to increase parallel performance and throughput. In synchronous systems, pipelining results in many partitioned or subdivided smaller blocks or stages and a system clock is applied to registers between the blocks/stages. The system clock initiates movement of the processing and data from one stage to the next, and the processing in each stage must be completed during one fixed clock cycle. When certain stages take less time than a clock cycle to complete processing, the next processing stages must wait—increasing processing delays (which are additive).
[0010] In contrast, asynchronous systems (i.e., clockless) do not utilize a system clock and each processing stage is intended, in general terms, to begin its processing upon completion of processing in the prior stage. Several benefits or features are present with asynchronous processing systems. Each processing stage can have a different processing delay, the input data can be processed upon arrival, and consume power only on demand.
[0011] FIG. 1 illustrates a prior art Sutherland asynchronous micro-pipeline architecture 100 . The Sutherland asynchronous micro-pipeline architecture is one form of asynchronous micro-pipeline architecture that uses a handshaking protocol built by Muller-C elements to control the micro-pipeline building blocks. The architecture 100 includes a plurality of computing logic 102 linked in sequence via flip-flops or latches 104 (e.g., registers). Control signals are passed between the computing blocks via Muller C-elements 106 and delayed via delay logic 108 . Further information describing this architecture 100 is published by Ivan Sutherland in Communications of the ACM Volume 32 Issue 6, June 1989 pages 720-738, ACM New York, N.Y., USA, which is incorporated herein by reference.
[0012] Now turning to FIG. 2 , there is illustrated a typical section or processing stage of a synchronous system 200 . The system 200 includes flip-flops or registers 202 , 204 for clocking an output signal (data) 206 from a logic block 210 . On the right side of FIG. 2 there is shown an illustration of the concept of meta-stability. Set-up times and hold times must be considered to avoid meta-stability. In other words, the data must be valid and held during the set-up time and the hold time, otherwise a set-up violation 212 or a hold violation 214 may occur. If either of these violations occurs, the synchronous system may malfunction. The concept of meta-stability also applies to asynchronous systems. Therefore, it is important to design asynchronous systems to avoid meta-stability. In addition, like synchronous systems, asynchronous systems also need to address various potential data/instruction hazards, and should include a bypassing mechanism and pipeline interlock mechanism to detect and resolve hazards.
[0013] Accordingly, there are needed asynchronous processing systems, asynchronous processors, and methods of asynchronous processing that are stable, and detect and resolve potential hazards (i.e, remove meta-stability).
SUMMARY
[0014] According to one embodiment, there is provided a clock-less asynchronous processor including a processing pipeline having a plurality of successive processing stages. Each processing stage includes asynchronous logic circuitry configured to process input data and output processed data, and a data storage element coupled to the asynchronous logic circuitry and configured to receive and store the processed output data in response to a current stage active complete signal. A self-clocked generator configured to receive a previous stage active complete signal is also included in each stage to generate the current active complete signal in response thereto, and output the current active complete signal to the data storage element and to a next processing stage.
[0015] In another embodiment, there is provided a method of operating a clock-less asynchronous processor having a processing pipeline having a plurality of successive processing stages, where each processing stage includes asynchronous logic circuitry, a data storage element coupled to the output of the asynchronous logic circuitry and a self-clocked generator. The method includes receiving input data from a previous stage data storage element; receiving, at the self-clocked generator, a previous stage active complete signal; processing the received input data through the asynchronous logic circuitry and outputting processed data; generating a current active complete signal in response to the received previous stage active complete signal and transmitting the current stage active complete signal to a next successive processing stage; and storing the processed data in a current data storage element in response to the current stage active complete signal.
[0016] In another embodiment, there is provided a clock-less asynchronous processor including a plurality of processing pipelines each having a plurality of successive processing stages configured to operate asynchronously. The plurality of processing stages include a first, second and third processing stages. The first asynchronous processing stage includes first asynchronous logic circuitry configured to process first input data and output first processed data, a first data storage element coupled to the first asynchronous logic circuitry and configured to receive and store the first processed output data in response to a first stage active complete signal generated and output by a first self-clocked generator. The second asynchronous processing stage includes second asynchronous logic circuitry configured to process the first output processed data and output second processed data, a second data storage element coupled to the second asynchronous logic circuitry and configured to receive and store the second processed output data in response to a second stage active complete signal, and a second self-clocked generator configured to receive the first stage active complete signal, generate the second active complete signal in response thereto, and output the second stage active complete signal to the second data storage element. The third asynchronous processing stage includes third asynchronous logic circuitry configured to process the second output processed data and output third processed data, a third data storage element coupled to the third asynchronous logic circuitry and configured to receive and store the third processed output data in response to a third stage active complete signal, and a third self-clocked generator configured to receive the second stage active complete signal, generate the third stage active complete signal in response thereto, and output the third stage active complete signal to the third data storage element.
[0017] In still another embodiment, there is provided a clock-less asynchronous circuit including asynchronous logic circuitry configured to process input data and output processed data, and further configured to perform either a first processing function associated with a first processing delay or a second processing function associated with a second processing delay. The circuit further includes a data storage element coupled to the asynchronous logic circuitry and configured to receive and store the processed output data in response to an active complete signal, and a self-clocked generator configured to: receive a trigger signal, and generate and output the active complete signal after receiving the trigger signal, the active complete signal generated and output after a predetermined time period from receipt of the trigger signal, wherein the predetermined time period is substantially equal to or greater than the first processing delay when the asynchronous logic circuitry will perform the first processing function or the predetermined time period is substantially equal to or greater than the second processing delay when the asynchronous logic circuitry will perform the second processing function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which:
[0019] FIG. 1 illustrates a prior art asynchronous micro-pipeline architecture;
[0020] FIG. 2 is a block diagram illustrating the concept of meta-stability in a synchronous system;
[0021] FIG. 3 illustrates an asynchronous processing system in accordance with the present disclosure;
[0022] FIG. 4 is a block diagram illustrating a single asynchronous processing stage within an asynchronous processor in accordance with the present disclosure;
[0023] FIG. 5 is a block diagram of one implantation of the self-clocked generator shown in FIG. 4 ;
[0024] FIGS. 6 and 7 illustrate other implementations of the self-clocked generator shown in FIG. 4 ;
[0025] FIG. 8 is a block diagram illustrating a processing pipeline having multiple processing stages in accordance with the present disclosure; and
[0026] FIGS. 9A , 9 B and 9 C illustrate an example communication system, and example devices, in which the asynchronous processor and processing system may be utilized.
DETAILED DESCRIPTION
[0027] Asynchronous technology seeks to eliminate the need of synchronous technology for a global clock-tree which not only consumes an important portion of the chip power and die area, but also reduces the speed(s) of the faster parts of the circuit to match the slower parts (i.e., the final clock-tree rate derives from the slowest part of a circuit). To remove the clock-tree (or minimize the clock-tree), asynchronous technology requires special logic to realize a handshaking protocol between two consecutive clock-less processing circuits. Once a clock-less processing circuit finishes its operation and enters into a stable state, a signal (e.g., a “Request” or “Complete” signal) is triggered and issued to its ensuing circuit. If the ensuing circuit is ready to receive the data, the ensuing circuit sends a signal (e.g., an “ACK” signal) to the preceding circuit. Although the processing latencies of the two circuits are different and varying with time, the handshaking protocol ensures the correctness of a circuit or a cascade of circuits.
[0028] Hennessy and Patterson coined the term “hazard” for situations in which instructions in a pipeline would produce wrong answers. A structural hazard occurs when two instructions might attempt to use the same resources at the same time. A data hazard occurs when an instruction, scheduled blindly, would attempt to use data before the data is available in the register file.
[0029] With reference to FIG. 3 , there is shown a block diagram of an asynchronous processing system 300 in accordance with the present disclosure. The system 300 includes an asynchronous scalar processor 310 , an asynchronous vector processor 330 , a cache controller 320 and L1/L2 cache memory 340 . As will be appreciated, the term “asynchronous processor” may refer to the processor 310 , the processor 330 , or the processors 310 , 330 in combination. Though only one of these processors 310 , 330 is shown, the processing system 300 may include more than one of each processor. In addition, it will be understood that each processor may include therein multiple CPUs, control units, execution units and/or ALUs, etc. For example, the asynchronous scalar processor 310 may include multiple CPUs with each CPU having a desired number of pipeline stages. In one example, the processor 310 may include sixteen CPUs with each CPU having five processing stages (e.g., classic RISC stages—Fetch, Instruction Decode, Execute, Memory and Write Back). Similarly, the asynchronous vector processor 330 may include multiple CPUs with each CPU having a desired number of pipeline stages.
[0030] The L1/L2 cache memory 340 may be subdivided into L1 and L2 cache, and may also be subdivided into instruction cache and data cache. Likewise, the cache controller 320 may be functionally subdivided.
[0031] Aspects of the present disclosure provide architectures and techniques for a clock-less asynchronous processor architecture that utilizes a configurable self-clocked generator to trigger the generation of the clock signal and to avoid meta-stability problems.
[0032] FIG. 4 illustrates a portion of a processing pipeline within the asynchronous processor 310 (or 330 ). The processing pipeline will include a plurality of successive processing stages. For illustrative purposes, FIG. 4 illustrates a single processing stage 400 within the pipeline. Each stage 400 includes a logic block 410 (or asynchronous logic circuitry), an associated self-clocked generator 420 , and a data storage element or latch (or flip-flop or register) 404 . In addition, a data latch (identified as 402 ) of a previous stage (identified as 412 ) is also shown. As will be appreciated for each stage, data processed by the respective logic block is output and latched into its respective data latch upon receipt of an active “complete” signal from the self-clocked generator associated with that stage. The logic block 410 may be any block or combination of processing logic configured to operate asynchronously as a unit or block. Some examples of such a block 410 may be an arithmetic logic unit (ALU), adder/multiplier unit, memory access logic, etc. In one example, which will be utilized hereafter to further explain the teachings and concepts of the present disclosure, the logic block 410 is a logic block configured to perform at least two different functions, such as an adder/multiplier unit. In this example, the logic block 410 has two processing time delays: the processing time required to complete the adding function and the processing time required to complete the multiplication function. In other words, the period of time between trigger and latching.
[0033] Data processed from the previous stage is latched into the data latch 402 (the previous stage has completed its processing cycle) in response to an active Complete signal 408 . The Complete signal 408 (or previous stage completion signal) is also input to the next stage self-clocked generator 420 indicating that the previous stage 412 has completed processing and the data in the data latch 402 is ready for further processing by stage 400 . The Complete signal 408 triggers the self-clocked generator 420 and activates self-clocked generation to generate its own current active Complete signal 422 . However, the self-clocked generator 420 delays outputting the current Complete signal 422 for a predetermined period of time to allow the logic block 410 to fully process the data and output processed data 406 .
[0034] The processing latency or delay of the logic block 410 depends on several factors (e.g., logic processing circuit functionality, temperature, etc.). One solution to this variable latency is to configure the delay to a delay value that is at least equal to, or greater than, than the worst case latency of the logic processing circuit 410 . This worst case latency is usually determined based on latency of the longest path in the worst condition. In the example of the adder/multiplier unit, the required processing delay for the adder may be 400 picoseconds, while the required processing delay for the multiplier may be 1100 picoseconds. In such case, the worst case processing delay would be 1100 picoseconds. This may be calculated based on theoretical delays (e.g., by ASIC level simulation: static timing analysis (STA) plus a margin), or may be measured during a calibration stage, of the actual logic block circuits 410 . Stage processing delay values for each stage 400 (and for each path/function in each stage 400 ) are stored in a stage clock delay table (not shown). During the initialization, reset or booting stage (referred to hereinafter as “initialization”), these stage delay values are used to configure clock-delay logic within the self-clocked generators 420 . In one embodiment, the stage delay values in the table are loaded into one or more storage register(s) (not shown) for fast access and further processing when needed. In the example of the adder/multiplier, the values 400 and 1100 (or other indicators representative of those values) are loaded into the register.
[0035] During initialization, the self-clocked generator 420 is configured to generate and output its active Complete signal 422 at a predetermined period of time after receiving the previous Complete signal 408 from the previous stage 412 . To ensure proper operation (processed data will be valid upon latching) the required processing delay will equal or exceed the time necessary for the block to complete its processing. Using the same example, then when the logic block is tasked with performing an adding function, the required processing delay should equal or exceed 400 picoseconds. Similarly, when the logic block is tasked with performing an adding function, the required processing delay should equal or exceed 1100 picoseconds. The self-clocked generator 1420 generates its Complete signal 1422 at the desired time which latches the processed output data 406 of logic block 410 into the data latch 404 . At the same time, the current active Complete signal 422 is output or passed to the next stage.
[0036] Now turning to FIG. 5 , there is illustrated a more detailed diagram of the configurable or programmable self-clocked generator 420 of FIG. 4 . The self-clocked generator 420 includes a first delay gate (or module or circuit) 502 A, a second delay gate (or module or circuit) 502 B, a first delay input multiplexor (mux) 504 A and a second delay input multiplexer 504 B. The multiplexors are configured to control an amount of delay between receipt of the previous Complete signal 408 and output (activation or assertion) of the current Complete signal 422 . Thus, the self-clocked generator 420 is configured to control/program a predetermined amount of delay (or time period). In one embodiment, the programmed period is operation dependent.
[0037] A configuration parameter 510 controls operation of the multiplexors 504 A, 504 B to select a signal path for the previous Complete signal 408 . This enables selection or configuration (programming) of when the clocking signal should be issued (i.e., how much delay)—a configurable amount of delay. For example, the first delay gate 502 A may be configured to generate a signal 503 having added 500 picoseconds of delay, while the second delay gate 502 B may be configured to generate a signal 505 having added 600 picoseconds of delay, for a possible total delay of 1100 picoseconds.
[0038] The configuration parameter 510 may be an N-bit select signal generated from the one or more storage registers (not shown) when the processor 310 , 330 is initialized. Therefore, the select signal may select the first signal 503 , the second signal 505 , a combination of the first signal 503 and the second signal 505 , or virtually no delay. In this example, the current Complete signal 422 may be generated and output with 0, 500, 600 or 1100 picoseconds of delay. For example, a first configuration parameter output 512 will cause the first multiplexor 504 A to select and output either the delayed signal (500 picoseconds) 503 or the undelayed signal 408 . Similarly, a second configuration parameter output 514 will cause the second multiplexor 504 B to select and output either (1) the delayed signal 505 (which is either delayed by 500 or 1100 picoseconds), (2) the delayed signal (600 picoseconds) output from the multiplexor 504 A, or (3) the undelayed signal 408 . In general terms, the self-clocked generator 420 provides a programmable delay measured defined as the amount of time between receipt of the previous Clocking signal 408 and activation of the current Complete signal 422 . Assertion of the Complete signal 422 latches the data and further signals the data is valid and ready for next stage processing.
[0039] In another embodiment, the configuration parameter 510 may generated by a controller 550 . The controller 550 determines which processing function (e.g., adding or multiplying) the logic block 410 will perform and programs the self-clocked generator 420 to generate the clocking signal 422 with the “correct” delay for that processing function. In other words, the controller 550 programs the self-clocked generator to issue its clocking signal after a predetermined processing time has passed. This predetermined processing time is defined and associated with the function to be performed. Various methods and means may be utilized to determine a priori which function will be performed by the logic block 410 . In one example, an instruction pre-decode indicates the particular processing function will be an add function or a multiply function. This information may be stored in a register or register file. Thus, the self-clocked generator 420 is programmed to generate the clocking signal 422 a predetermined amount of time after receipt of a previous clock signal (or other signal) signaling to the logic block 422 that the input data is ready for processing. This predetermined amount of time is programmed in response to a determination of what function the logic block 422 will perform.
[0040] While first and second delay gates, first and second multiplexors, and first and second configuration parameters have been described in the examples above for ease of explanation, it should be appreciated that additional delay gates (and differing delay times) and multiplexors may be utilized.
[0041] Now turning to FIG. 6 , there is illustrated another implementation of the programmable delay self-clocked generator 420 having an M-to-1 multiplexer 600 with M clock input signals 620 . Similar to the configuration parameter 510 , an N-bit configuration parameter 610 (and/or a controller) controls multiplexer 600 to select one of the M clock inputs 620 for output of the current Complete signal 422 . As will be appreciated, the clock input signals 620 are generated from the previous stage Complete signal (e.g., signal 408 in FIG. 5 ) and each are delayed by a different amount. The clock input signals are generated using any suitable configuration of clock delay gates/circuits (not shown). For example, if M=8, the eight clock input signals may be delayed in increments of 100 picoseconds beginning with 400 picoseconds. In such example, current Complete signal 422 can be selected to have a delay ranging from 400-1100 picoseconds, in increments of 100 picoseconds. It will be understood that any suitable number of clock input signals 620 and delay amounts can be configured and utilized.
[0042] Now turning to FIG. 7 , there is illustrated another implementation of the programmable delay self-clocked generator 420 . In this configuration, the self-clocked generator 420 includes a number of logic gates (as shown) and two clock input signals 702 , 704 configured to select and output one of the clock input signals. A single Select line 720 controls which clock input signal 702 , 704 is selected and output as the clock output signal 422 (Complete signal).
[0043] Now turning to FIG. 8 , there is illustrated a block diagram of a portion of a processing pipeline 800 having a plurality of processing stages within the asynchronous processor 310 , 330 . As will be appreciated, the pipeline 800 may have any number of desired stages 400 . As an example only, the pipeline 800 may include 5 stages (with only 3 shown in FIG. 8 ) with each stage 400 providing different functionality (e.g., Instruction Fetch, Instruction Decode, Execution, Memory, Write Back). Further, the processor may include any number of separate pipelines 800 (e.g., CPUs or execution units).
[0044] As shown, the pipeline 800 includes a plurality of successive processing stages 400 A, 400 B, 400 C. Each respective processing stage 400 A, 400 B and 400 C includes a logic block (asynchronous logic circuitry) 410 A, 410 B and 410 C, and associated self-clocked generators 420 A, 420 B and 420 C and data latches 404 A, 404 B, 404 C. Reference is made to FIG. 4 illustrating more details and operation of a stage 400 .
[0045] As will be appreciated, each logic block 410 A, 410 B and 410 C includes asynchronous logic circuitry configured to perform one or more processing functions on the input data. When data processing is complete (i.e., sufficient time has passed to complete processing), the processed data is latched into the data storage element or flip-flop 404 A, 404 B, 404 C in response to the Complete signal 422 A, 422 B and 422 C (which also indicates to a subsequent stage that processing is complete). Each intermediate successive stage 400 processes input data output from a previous stage.
[0046] The amount of processing time necessary for each logic block 410 to complete processing depends on the particular circuits included therein and the function(s) it performs. Each logic block 410 A, 410 B and 410 C has one or more predetermined processing time delays which indicate the amount of time it takes to complete a processing cycle. As previously described, stage processing delay values for each stage 400 are stored in a stage clock delay table (not shown) and may be loaded into a data register or file during initialization.
[0047] For example only, the processing delays may be 500, 400 or 1100, and 600 or 800 picoseconds for stages 400 A, 400 b , 400 C, respectively. This means that stage 400 A is either capable of performing only one function (or has only one path) or can perform multiple functions, but each function requires about the same processing delay. Stages 400 B, 400 C are capable of performing at least two functions (or have at least two paths) with each function requiring a different processing delay.
[0048] Aspects of the present disclosure also provide architectures and techniques for a clock-less asynchronous processor that utilizes a first mode to initialize and set up the asynchronous processor during boot up and that uses a second mode during “normal” operation of the asynchronous processor.
[0049] With continued reference to FIG. 8 , the processor 310 , 330 includes mode selection (and delay configuration) logic 850 . The mode selection circuit 850 configures the processor 310 , 330 to operate in one of two modes. In one embodiment, these two modes include a Slow mode and a Fast mode. Additional modes could be configured if desired. It will be understood that the mode selection logic may be implemented using logic hardware, software or a combination thereof. The logic 850 configures, enables and/or switches the processor 310 , 330 to operate in a given mode and switch between modes.
[0050] In the Slow mode, each self-clocked generator 420 A, 420 B, 420 C is configured to generate its respective active Complete signal 422 A, 422 B, 422 C with a maximum amount of delay (which may be the same or different for each stage). In the Fast mode, each self-clocked generator 420 A, 420 B, 420 C is configured to generate its respective Complete signal 422 A, 422 B, 422 C with a predetermined (or “correct”) amount of delay (again, this may be the same or different for each stage, depending on functionality of the logic as well as different processing, voltage and temperature (PVT) corners). In general terms, the amount of delay in the Slow mode is greater than the amount of delay in the Fast mode and, therefore, the Fast mode performs processing at a faster speed.
[0051] Using the example above in which the processing delays are 500, 400 or 1100, and 600 or 800 picoseconds, for stages 400 A, 400 b , 400 C, respectively, the Slow mode will initialize or program the self-clocked generators 420 A, 420 B, 420 C for processing delays of 500, 1100 and 800 picoseconds. This ensures that each stage will be programmed with a sufficient processing delay amount to handle initialization procedures. The Fast mode enables each stage to operate in accordance with the procedures and methods described above—the processing delay for a stage will be programmed or set based on which particular function that respective logic block 410 will be performing at that time.
[0052] It will be understood there may be some hardware initialization/setup sequence(s) for which it may be desirable to operate in a slower mode to properly configure the logic. During slow mode, the delay can be set relatively large to ensure logic functionality and no meta-stability. Other examples may include applications for which the circuit speed should be slowed down, such as a special register configuration or process. As will be appreciated, different asynchronous logic circuits could be switched to faster speeds globally or locally (one by one).
[0053] Various factors may determine when the processor 310 , 330 should operate in either one of the modes. These may include power consumption/dissipation requirements, operating conditions, types of processing, PVT corners, application real time requirements, etc. Different factors may apply to different applications, and any suitable determination of when to switch from one mode to another mode is within the knowledge of those skilled in the art. In other embodiments, the concepts described herein are broader, and may include switching between a first and second mode, switching between slow and fast modes, and having multiple modes (three or more). Multiple modes within normal operation may be provided, and may be implemented to vary core speeds and to adapt to different PVT or application real time requirement(s).
[0054] In one embodiment, the processor 310 , 330 is configured to operate in the Slow mode during initialization and setup (e.g., boot, reset, initialization, etc.). After initialization is completed, the processor 310 , 330 is configured to operate in the Fast mode—which is considered “normal” operation of the processor. The mode selection and configurable delay logic 850 includes a slow mode module 812 configured to generate a maximum delay for each of the self-clocked generators 420 A- 420 C and a fast mode module 814 configured to generate a “correct” delay for each of the self-clocked generators 420 A- 420 C. The maximum delay for a given self-clocked generator may be different than the maximum delay for another one of the self-clocked generators. Similarly, the “correct” delay(s) for a given self-clocked generator may be different than the “correct” delay(s) for another one of the self-clocked generators.
[0055] In one embodiment, the maximum delay for a given self-clocked generator 420 may be equal to a guaranteed delay without meta-stability+margin. For example, the configurable delay logic 850 may be configured to generate a slow mode configure signal corresponding to a slow mode delay value that is associated with a slowest speed at which the given self-clocked generator 420 can successfully process and operate. If it can perform multiple functions (or have multiple paths), the maximum processing delay for the logic block is the longest delay of the longest path of a given logic block 410 in the worst working condition. This may be measured at the wafer calibration stage for the given logic block 410 (or calculated theoretically). The configurable delay logic 850 is also configured to generate a fast mode configure signal that enables the logic block to operate in a “normal” mode—the processing delay for a stage will be programmed or set based on which particular function that respective logic block 410 will be performing at that time. Each of the self-clocked generators 420 A- 420 C is configured to generate an active Complete signal 422 A- 422 C in response to receipt of a corresponding delay configure signal 820 A- 820 C from the delay logic 850 .
[0056] During initialization of the processor 310 , 330 , the self-clocked generator 420 A may receive the delay configure signal 820 A and enter the slow mode during initialization and set up the processor. Alternatively, the self-clocked generator 420 A may enter the slow mode by default during initialization. After completion of initialization, the self-clocked generator 420 A may enter the fast mode for normal operation (in response to the delay configure signal 820 A). The other self-clocked generators 420 B, 420 C may similarly operation in response to the delay configure signal 820 B and delay configure signal 820 C. Alternatively, these self-clocked generators may enter the slow mode by default during initialization, and after initialization and set up, they may enter the fast mode during normal operation (in response to the delay configure signals 820 B, 820 C).
[0057] During operation, the mode selection and configurable delay logic 850 is configured to generate a maximum delay such that asynchronous logic circuitry 410 executes in the first or slow mode during initialization. In a particular implementation, the slow mode may include a maximum delay for each of the self-clocked generators 420 A- 420 C. A first flag may be written to a register or other memory location in the processor 310 , 330 to maintain the slow mode until initialization is complete. Thereafter, the configurable delay logic 850 configures the self-clocked generators to generate “correct” delay(s) such that the asynchronous logic circuitry 410 executes in the second or fast mode during normal operation. Thus, in the embodiment described mainly in FIG. 8 , the programmed processing delay (or period of time between trigger and latching) is mode dependent.
[0058] FIG. 9A illustrates an example communication system 300 A that may be used for implementing the devices and methods disclosed herein. In general, the system 900 A enables multiple wireless users to transmit and receive data and other content. The system 900 A may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA).
[0059] In this example, the communication system 900 A includes user equipment (UE) 910 a - 910 c , radio access networks (RANs) 920 a - 920 b , a core network 930 , a public switched telephone network (PSTN) 940 , the Internet 950 , and other networks 960 . While certain numbers of these components or elements are shown in FIG. 9A , any number of these components or elements may be included in the system 900 A.
[0060] The UEs 910 a - 910 c are configured to operate and/or communicate in the system 900 A. For example, the UEs 910 a - 910 c are configured to transmit and/or receive wireless signals or wired signals. Each UE 910 a - 910 c represents any suitable end user device and may include such devices (or may be referred to) as a user equipment/device (UE), wireless transmit/receive unit (WTRU), mobile station, fixed or mobile subscriber unit, pager, cellular telephone, personal digital assistant (PDA), smartphone, laptop, computer, touchpad, wireless sensor, or consumer electronics device.
[0061] The RANs 920 a - 920 b include base stations 970 a - 970 b , respectively. Each base station 970 a - 970 b is configured to wirelessly interface with one or more of the UEs 910 a - 910 c to enable access to the core network 930 , the PSTN 940 , the Internet 950 , and/or the other networks 960 . For example, the base stations 970 a - 970 b may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node-B (NodeB), an evolved NodeB (eNodeB), a Home NodeB, a Home eNodeB, a site controller, an access point (AP), or a wireless router, or a server, router, switch, or other processing entity with a wired or wireless network.
[0062] In the embodiment shown in FIG. 9A , the base station 970 a forms part of the RAN 920 a , which may include other base stations, elements, and/or devices. Also, the base station 970 b forms part of the RAN 920 b , which may include other base stations, elements, and/or devices. Each base station 970 a - 970 b operates to transmit and/or receive wireless signals within a particular geographic region or area, sometimes referred to as a “cell.” In some embodiments, multiple-input multiple-output (MIMO) technology may be employed having multiple transceivers for each cell.
[0063] The base stations 970 a - 970 b communicate with one or more of the UEs 910 a - 910 c over one or more air interfaces 990 using wireless communication links. The air interfaces 990 may utilize any suitable radio access technology.
[0064] It is contemplated that the system 900 A may use multiple channel access functionality, including such schemes as described above. In particular embodiments, the base stations and UEs implement LTE, LTE-A, and/or LTE-B. Of course, other multiple access schemes and wireless protocols may be utilized.
[0065] The RANs 920 a - 920 b are in communication with the core network 930 to provide the UEs 910 a - 910 c with voice, data, application, Voice over Internet Protocol (VoIP), or other services. Understandably, the RANs 920 a - 920 b and/or the core network 930 may be in direct or indirect communication with one or more other RANs (not shown). The core network 930 may also serve as a gateway access for other networks (such as PSTN 940 , Internet 950 , and other networks 960 ). In addition, some or all of the UEs 910 a - 910 c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and/or protocols.
[0066] Although FIG. 9A illustrates one example of a communication system, various changes may be made to FIG. 9A . For example, the communication system 900 A could include any number of UEs, base stations, networks, or other components in any suitable configuration, and can further include the EPC illustrated in any of the figures herein.
[0067] FIGS. 9B and 9C illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, FIG. 9B illustrates an example UE 910 , and FIG. 9C illustrates an example base station 970 . These components could be used in the system 900 A or in any other suitable system.
[0068] As shown in FIG. 9B , the UE 910 includes at least one processing unit 905 . The processing unit 905 implements various processing operations of the UE 910 . For example, the processing unit 905 could perform signal coding, data processing, power control, input/output processing, or any other functionality enabling the UE 910 to operate in the system 900 A. The processing unit 905 also supports the methods and teachings described in more detail above. Each processing unit 905 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 905 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit. The processing unit 905 may be an asynchronous processor 310 , 330 or the processing system 300 as described herein.
[0069] The UE 910 also includes at least one transceiver 902 . The transceiver 902 is configured to modulate data or other content for transmission by at least one antenna 904 . The transceiver 902 is also configured to demodulate data or other content received by the at least one antenna 904 . Each transceiver 902 includes any suitable structure for generating signals for wireless transmission and/or processing signals received wirelessly. Each antenna 904 includes any suitable structure for transmitting and/or receiving wireless signals. One or multiple transceivers 902 could be used in the UE 910 , and one or multiple antennas 904 could be used in the UE 910 . Although shown as a single functional unit, a transceiver 902 could also be implemented using at least one transmitter and at least one separate receiver.
[0070] The UE 910 further includes one or more input/output devices 906 . The input/output devices 906 facilitate interaction with a user. Each input/output device 906 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen.
[0071] In addition, the UE 910 includes at least one memory 908 . The memory 908 stores instructions and data used, generated, or collected by the UE 910 . For example, the memory 908 could store software or firmware instructions executed by the processing unit(s) 905 and data used to reduce or eliminate interference in incoming signals. Each memory 908 includes any suitable volatile and/or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and the like.
[0072] As shown in FIG. 9C , the base station 970 includes at least one processing unit 955 , at least one transmitter 952 , at least one receiver 954 , one or more antennas 956 , one or more network interfaces 966 , and at least one memory 958 . The processing unit 955 implements various processing operations of the base station 970 , such as signal coding, data processing, power control, input/output processing, or any other functionality. The processing unit 955 can also support the methods and teachings described in more detail above. Each processing unit 955 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 955 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit. The processing unit 955 may be an asynchronous processor 310 , 330 or the processing system 300 as described herein.
[0073] Each transmitter 952 includes any suitable structure for generating signals for wireless transmission to one or more UEs or other devices. Each receiver 954 includes any suitable structure for processing signals received wirelessly from one or more UEs or other devices. Although shown as separate components, at least one transmitter 952 and at least one receiver 954 could be combined into a transceiver. Each antenna 956 includes any suitable structure for transmitting and/or receiving wireless signals. While a common antenna 956 is shown here as being coupled to both the transmitter 952 and the receiver 954 , one or more antennas 956 could be coupled to the transmitter(s) 952 , and one or more separate antennas 956 could be coupled to the receiver(s) 954 . Each memory 958 includes any suitable volatile and/or non-volatile storage and retrieval device(s).
[0074] Additional details regarding UEs 910 and base stations 970 are known to those of skill in the art. As such, these details are omitted here for clarity.
[0075] In some embodiments, some or all of the functions or processes of the one or more of the devices are implemented or supported by a computer program that is formed from computer readable program code and that is embodied in a computer readable medium. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory.
[0076] It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
[0077] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.
|
A clock-less asynchronous processing circuit or system having a plurality of pipelined processing stages utilizes self-clocked generators to tune the delay needed in each of the processing stages to complete the processing cycle. Because different processing stages may require different amounts of time to complete processing or may require different delays depending on the processing required in a particular stage, the self-clocked generators may be tuned to each stage's necessary delay(s) or may be programmably configured.
| 6
|
PRIORITY CLAIM
[0001] This patent application is a U.S. National Phase of International Patent Application No. PCT/EP2010/007091, filed 23 Nov. 2010, which claims priority to German Patent Application No. 10 2009 060 169.4, filed 23 Dec. 2009, the disclosures of which are incorporated herein by reference in their entirety.
FIELD
[0002] Embodiments of the present disclosure relate to a method for the automatic forward parking of a motor vehicle in a perpendicular parking space and to a corresponding driver assistance system.
BACKGROUND
[0003] In current parking assist systems or driver assistance systems for automatic parking, in which case parking both in the longitudinal parking spaces and in perpendicular parking spaces is carried out here, a parking space is measured using a suitable sensor system as the parking space is passed, and reverse parking is then carried out. With longitudinal parking spaces, this is the only possible way of parking in a longitudinal parking space since the rear axle generally cannot be steered. Longitudinal parking spaces in which forward parking is possible are so large, however, that it would be necessary to refer to a lane change, rather than parking.
[0004] Such a reverse parking operation into a parking space is described, for example, in DE 10 2009 006 336 A1. There, an automatic parking operation of a motor vehicle is monitored, in which case, before the actual parking operation, a parking space is measured using a camera-based method as the motor vehicle passes the parking space, and obstacles in the environment of the parking space are also determined. During the automatic parking operation, the camera-based method is still used to measure the environment of the motor vehicle, the obstacles newly detected in the measurement during the parking operation being compared with previously detected obstacles and a corresponding measure being carried out if there is a discrepancy between newly detected obstacles and known obstacles.
[0005] A method for automatically parking a motor vehicle in a parking space or for moving a motor vehicle out of a parking space can also be gathered from DE 10 2009 006 331 A1. In this case, the parking space is determined by an environment detection system of the motor vehicle and a target trajectory and a position end point relative to the parking space on the target trajectory are defined. A suitable steering angle is then calculated on the basis of the current vehicle position and this steering angle is used for parking or leaving a parking space.
[0006] The common feature of all of these known methods is that, after the parking space has been measured, a target trajectory is defined and is iteratively readjusted if necessary, along which trajectory the motor vehicle reverses into the parking space in one or more maneuvers.
[0007] The disadvantage of the reverse-parking strategies is that, on the one hand, the subsequent traffic is hindered during reverse-parking into a perpendicular parking space and there is also the risk of a subsequent vehicle taking the free parking space by means of forward parking and of forward parking usually being carried out both in parking garages and in garages.
SUMMARY
[0008] Therefore, the disclosed embodiments are based on specifying a method for the forward parking of a motor vehicle in a perpendicular parking space, including a garage.
[0009] This is achieved by means of a method without previous measurement of the parking space having the features of claim 1 , a method with previous measurement of the perpendicular parking space according to the features of claim 10 and a driver assistance apparatus for carrying out the methods having the features of claim 12 .
BRIEF DESCRIPTION OF THE FIGURES
[0010] The embodiments of the disclosure are described below using the drawings, in which:
[0011] FIG. 1 shows a forward parking operation according to a first disclosed embodiment,
[0012] FIGS. 2 a and 2 b show single-maneuver forward parking maneuvers,
[0013] FIG. 3 shows a diagrammatic illustration of multi-maneuver parking, and
[0014] FIG. 4 shows a diagrammatic illustration of a parking operation according to a second disclosed embodiment.
DETAILED DESCRIPTION
[0015] In a first disclosed embodiment, the method for the forward parking of a motor vehicle in a perpendicular parking space, the motor vehicle having environment sensors for determining environment data and obstacles in the environment of the motor vehicle, includes:
prealigning the motor vehicle in front of the perpendicular parking space in such a manner that a setpoint steering angle is between a maximum steering angle δ max and a minimum steering angle δ min , iteratively searching the permissible steering angle range between the maximum steering angle δ max and the minimum steering angle δ min for a current steering angle δ curr,i during a forward maneuvering movement of the motor vehicle into the perpendicular parking space, the current steering angle δ curr, i giving rise to a maximum free path length s i , i=0, . . . n, into the perpendicular parking space without the vehicle hitting obstacles, and terminating the forward maneuvering movement if the end of the parking operation has been reached or a reverse maneuvering movement must be carried out on account of an obstacle.
[0019] In this case, the maximum steering angle δ max and minimum steering angle δ min may be in the range ±17°.
[0020] Obstacles which have been found are optionally recorded, that is to say stored, in a map of the environment by the environment sensors. Obstacles which disappear again are likewise removed again from the map of the environment.
[0021] The first step i=0 of the iterative search may be carried out by scanning a predefined curvature range κveh;i=0 with a predefined curvature iteration size Δκ in order to determine an ideal curvature estimated value, and the forward maneuvering movement of the motor vehicle is carried out along the ideal curvature estimated value of the first step. In this case, the curvature estimated value of the first step corresponds to the maximum free path length si=0. Furthermore, the curvature estimated value determines the steering angle of the vehicle.
[0022] The predefined curvature range of the first step comprises the range of −0.15 to 0.15, the curvature iteration size Δκ of the first iteration step being 0.0005. In this case, the predefined curvature range of −0.15 to +0.15 corresponds to a minimum steering angle and a maximum steering angle of approximately ±17° for a wheel base of approximately 2 m.
[0023] For the second step and the subsequent steps i=1, 2, . . . , n of the iteration, the curvature estimated value of the previous step is used as the initial value for the current step, scanning being carried out around the initial value of the previous step with a current curvature iteration size to determine the current curvature estimated value of the i-th step, the current curvature iteration size being a function of the maximum path length si-1 of the previous step. Furthermore, the curvature range to be searched in the current step to determine the current curvature estimated value is a function of the curvature iteration size of the current step, and the forward maneuvering movement of the motor vehicle is carried out along the current curvature estimated value of the second step and the subsequent steps.
[0024] The curvature iteration size of the second step and the subsequent steps is optionally determined by means of the following formula:
[0000]
Δ
κ
=
Δ
κ
0
(
min
(
s
i
-
1
,
σ
0
)
/
σ
0
)
2
(
1
)
[0025] In this case, s i-1 is the maximum distance determined in the previous step and σ 0 is an experimentally determined constant. In the present case, σ 0 =3 m has proved to be a reasonable value.
[0026] To determine the current curvature estimated value, the curvatures, that is to say the following curvature range, are optionally searched:
[0000] κ search,j =κ 0 +( j− 3)Δκ (2)
[0027] In this case, optionally j=0, 1, m, where m is a natural number >0. Optionally, m=6, in other words the search range comprises seven values. Other values for m are naturally possible, as a result of which the search range becomes larger or smaller. Furthermore, K o is defined as the curvature of the previous step, that is to say
[0000] κ 0 =κ veh,i-1 (3)
[0000] Furthermore, it is possible to determine the vehicle alignment relative to the parking space by considering the detected lateral obstacles which are within a predefined distance value, a left-hand regression line and a right-hand regression line respectively being placed through the obstacle points defined by distances between the lateral, that is to say left-hand and right-hand, obstacles. The position and alignment of the vehicle relative to the perpendicular parking space can then be determined from the two regression lines by means of averaging and by considering the enclosed angle. In this case, the position and alignment during the forward maneuvering movement can likewise be taken into account. For the reverse maneuvering movement, the detection of the alignment of the vehicle in the parking space and, therefrom, the average distances from the vehicle to the left and the right is used to look for a favorable starting position for the subsequent forward maneuvering movement.
[0028] A second disclosed embodiment of the method for the forward parking of a motor vehicle in a perpendicular parking space involves the motor vehicle having environment sensors for determining environment data and obstacles in the environment of the motor vehicle, a perpendicular parking space being measured by the environment sensors as the motor vehicle passes the perpendicular parking space. A parking trajectory for the forward parking of the motor vehicle relative to the current location of the motor vehicle is then calculated, the motor vehicle being aligned by a reverse movement in such a manner that it can park in the perpendicular parking space with a subsequent forward movement. For the iterative forward parking of the motor vehicle in the perpendicular parking space, the vehicle can move along the calculated trajectory, the trajectory being able to be corrected again and again by means of current environment data. It is also possible for the forward movement of the motor vehicle to be effected by means of the above-described iterative method of the first embodiment.
[0029] As already mentioned, during the automatic parking operation, the environment sensors can still measure the environment of the vehicle, and the parking trajectory can thus be adapted to the new environment data.
[0030] A driver assistance system for the automatic parking of a motor vehicle and for carrying out the methods described above comprises environment sensors for determining environment data relating to the motor vehicle, a calculation unit for continuously calculating a parking trajectory from the environment data, and a controller which moves the motor vehicle. In this case, the controller comprises actuators for accelerating and decelerating the motor vehicle, actuators for a braking intervention and actuators for a steering intervention.
[0031] FIG. 1 shows a vehicle 1 which has a diagrammatically illustrated front axle 2 and rear axle 3 and is in front of a parking space 4 . In this case, a steering angle range 5 min and δmax is diagrammatically illustrated in FIG. 1 . The steering angle range between δmin and δmax is searched for steering angles which make it possible to travel as far as possible without hitting obstacles. Two possible curvatures, that is to say steering angles, 5 , 6 are illustrated in FIG. 1 , in which case it is clear that it is possible to travel further into the perpendicular parking space 4 with the curve 5 than with the curve 6 . The route which provides the greatest distance without hitting an obstacle, that is to say the curve 5 in the present case, predefines the steering angle, that is to say the curvature, which is then taken in the first step. As a note, it is remarked that travel straight ahead is carried out with the proposed iterative method in the absence of obstacles. Therefore, the method can be used not only in garages but also in confined driving situations.
[0032] At the start of the keying-in algorithm, the entire possible curvature range κi=0=−0.15 . . . 0.15 is scanned in curvature iteration sizes of Δκ=0.0005 to obtain a lower initial value for κi=0. This initial value and also all subsequent values always use the curvature determined last as a good estimation of the current iteration step to restrict the search space for the subsequent steps. This is because, in the subsequent steps, there is a restriction for reasons of the computation power of the search space and a search is carried out for new optimum curvatures only in the area surrounding the curvature determined last. to escape from local minima which are produced, in particular, when the vehicle approaches an obstacle, the curvature iteration size of each step is coupled to the free path length si-1 from the last step, that is to say
[0000]
Δ
κ
=
Δ
κ
0
(
min
(
s
i
-
1
,
σ
0
)
/
σ
0
)
2
(
1
)
[0000] where σ 0 =3 m is an experimentally determined constant and s i-1 is the maximum distance determined from the last step. The local minima, where a current minimum may also be a global minimum, can be recognized from the fact that the maximum distance becomes smaller and smaller. Therefore, the search range is then increased to possibly escape from a local minimum.
[0033] When searching for a new ideal curvature, the curvatures
[0000] κ search,j =κ 0 +( j− 3)Δκ (2)
[0000] around the curvature from the last step are checked, where j can assume the values j=0, . . . , 6 and K 0 is the curvature found in the preceding step, that is to say K 0 =K veh,i-1 .
[0034] With each of these path curvatures, an area on the roadway which is restricted by the vehicle boundaries is defined. Therefore, in the case of a left turn, the left rear corner and the front right corner form the area boundary and, in the case of a right turn, the front left corner and the rear right corner form the area boundary, as is also illustrated by the curves 5 , 6 in FIG. 1 .
[0035] There are now two possibilities of why a forward movement must be stopped. Either the vehicle has reached the end of the parking operation or the vehicle must carry out a reverse maneuvering movement to circumvent an obstacle.
[0036] FIG. 2 a and FIG. 2 b thus show two possible single-maneuver parking scenarios for different starting positions of the vehicle 1 in front of the parking space 4 . In other words, the driver approaches a favorable starting position for forward parking, that is to say he positions himself favorably in front of a garage, for example, and gives the driver assistance system the signal to carry out the parking operation using the iterative procedure.
[0037] However, during forward parking, the situation may occur in which the steering lock would mean a long collision-free route for the front of the vehicle but the side of the vehicle would collide with an obstacle, for example one of the corners of a garage. If this is the case, the vehicle must first reverse to achieve a favorable starting position.
[0038] This is illustrated in FIG. 3 in which the vehicle 1 would hit the left-hand edge (viewed in the direction of travel) of the perpendicular parking space in the fifth iteration step. Consequently, the vehicle carries out a reverse movement to avoid a collision with an obstacle. In other words, starting from an unfavorable starting position of the vehicle 1 in front of the perpendicular parking space 4 , the vehicle carries out a first forward movement 8 until the risk of a collision between a side of the vehicle 1 and a corner 7 of the perpendicular parking space 4 is imminent. To avoid the collision, the vehicle carries out a first reverse movement 9 to maneuver the vehicle 1 into a more favorable new starting position. For this purpose, the last position of the vehicle 1 in the parking space 4 along the first forward movement and its alignment can be taken into account to arrive at a more favorable new starting position. In other words, the longitudinal axis of the vehicle 1 must be brought closer to the longitudinal axis 11 of the perpendicular parking space 4 . The vehicle 1 then carries out a new second forward movement 10 into the parking space 4 .
[0039] The end of the forward parking operation is reached when either the end of the parking space is reached, in which case a parking space detection defines a destination, or when the driver forwards a corresponding signal to the vehicle. The realization of whether onward travel is blocked with an obstacle can be predefined by means of a minimum distance.
[0040] FIG. 4 finally shows a parking operation after previous measurement of the parking space. In this case, the vehicle 1 is driven past the parking space 4 and has measured the parking space 4 using suitable environment sensors. It was also signaled to the driver that the parking space is large enough. Starting from a starting position A, the driver assistance unit calculates a parking trajectory, a first reverse movement 12 changing the vehicle from the position A to an intermediate position B which is suitable for a forward parking operation. The vehicle 1 is changed to the position C in the parking space 4 with a subsequent forward movement 13 . Conventional trajectory planning systems can be used to plan the trajectory of the forward movement, the iterative forward parking method described above likewise being able to be used for the forward trajectory 13 .
LIST OF REFERENCE SYMBOLS
[0000]
1 Vehicle
2 Front axle (steerable)
3 Rear axle
4 Parking space
5 Curve
6 Curve
7 Corner of the perpendicular parking space
8 First forward movement
9 First reverse movement
10 Second forward movement
11 Longitudinal axis of the parking space
12 Reverse movement
13 Forward movement
A Starting position
B Intermediate position
C End position
|
A method for forward parking a motor vehicle in a perpendicular parking space, wherein the motor vehicle has environment sensors for detecting environment data and obstacles in the environment of the motor vehicle, including pre-aligning the motor vehicle in front of the perpendicular parking space such that a target steering angle lies between a maximum steering angle δ max and a minimum steering angle δ min , iterative searching of the admissible steering angle range between the maximum steering angle δ max and the minimum steering angle δ min for a current steering angle δ akt , during a forward maneuver of the vehicle into the perpendicular parking space, wherein the current steering angle δ akt,i ensures a maximum free path length s i , i=01 . . . , n into the perpendicular parking space without the vehicle hitting obstacles, and terminating the forward maneuver if the end of the parking operation has been reached or a reversing maneuver has to be carried out owing to an obstacle.
| 1
|
FIELD OF THE INVENTION
[0001] The instant invention is directed generally to devices used by orthopedic surgeons to stabilize and align skeletal structures. More specifically, the instant invention includes a fastener capable of rotation about an axis within a supporting cup, the cup contoured to receive a rod therein and a means to fix the rod and rotationally oriented fastener in a fixed position.
BACKGROUND OF THE INVENTION
[0002] Orthopedic procedures involving stabilization of skeletal structure presently suffer from two common frailties: the first is the inability to orient the stabilizing structure for a multiplicity of common angulations and the second is the failure to provide a reliable thread portion which engages bone of the patient.
SUMMARY OF THE INVENTION
[0003] The instant invention provides the ability to address various skeletal components in a relational way by allowing articulation of the device in a multiplicity of angulations and to fasten to the skeletal structure to provide greater stabilization with an improved thread pattern which provides both axially compressive forces along the length of the fastener and radially inward drawing forces.
OBJECTS OF THE INVENTION
[0004] Accordingly, it is a primary object of the present invention to provide an orthopedic stabilization structure.
[0005] A further object of the present invention is to provide an improved threaded portion therefore.
[0006] A further object of the present invention is to accommodate a plurality of angulations when addressing a skeletal structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a top view of the fastener.
[0008] [0008]FIG. 2 is a side view of the fastener.
[0009] [0009]FIG. 3 is a sectional view of the fastener geometry.
[0010] [0010]FIG. 3A shows FIG. 3 with a taper.
[0011] [0011]FIG. 4 shows the fastener and stabilization structure.
[0012] [0012]FIG. 5 is another view of FIG. 4.
[0013] [0013]FIG. 6 displays angulation of the FIG. 4 structure.
[0014] [0014]FIG. 7 details a bolt used in the structure.
[0015] [0015]FIG. 8 details the bolt receiving area.
[0016] [0016]FIG. 9 shows one side of the cup.
[0017] [0017]FIG. 10 shows an adjacent side (90 degrees) relative to FIG. 9, showing a diametrical slot.
[0018] [0018]FIG. 11 is a top view of FIGS. 9 and 10.
[0019] [0019]FIG. 12 is a bottom view of FIGS. 9 through 11.
[0020] [0020]FIG. 13 is a sectional view of FIG. 9 along lines 13 - 13 .
[0021] [0021]FIG. 14 is a sectional view similar to FIG. 4.
[0022] [0022]FIG. 15 adds a fastener and rod to FIG. 14.
[0023] [0023]FIG. 16 adds a fixing bolt to FIG. 15.
[0024] [0024]FIG. 17 shows the device deployed by way of example.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral 100 is directed to the orthopedic stabilization device according to the present invention.
[0026] The device 100 allows a threaded fastener 10 to move about the arrow C as shown in FIG. 4 such that although the long axis of the threaded shaft is depicted as presently aligned, it can be rotated and skewed from a vertical long axis of a cup 130 as in FIG. 6. A rotational means 120 embodied as a disc has a cylindrical outer face 122 and planar top and bottom faces 124 , 126 . Thus, rotation about the arrow C occurs about a geometrical center 128 . The disc 120 is integrally fixed to fastener 10 . The rotational means 120 is constrained within a cup 130 having a central bore 132 , an upper portion of which is provided with threads 111 . In addition, a transverse slot 134 is cut along a diameter of the cup which allows slideable insertion therein of both the fastener 10 and integral disc 120 as well as a rod 136 transverse to a long axis of the cup 130 . Please see FIGS. 9 through 16. The cup 130 is dimensioned such that the rotational means 120 is in tangential registry along one cylindrical face 122 with the rod 136 . The threaded bore 132 receives a threaded fixing bolt 110 therewithin to press the rod 136 against the rotational means 120 to fix their relative relationship once appropriate orientation has occurred.
[0027] In its essence, the fastener 10 includes a threaded shaft 32 having a first thread pattern 12 at one end and a second thread pattern 14 at an opposite end. As shown in FIGS. 1 and 2, the first end thread pattern 12 terminates in a point 16 and the threads increase in diameter to form a thread pattern with its spiral increasing as it extends away from the point 16 .
[0028] The second thread pattern 14 has a larger diameter but a similar thread contour which shall be discussed in detail infra. Preferably, the shaft 32 is of variable length and tapers and narrows from end 18 to point 16 . Please see FIGS. 1 and 2.
[0029] A further nuance of the first and second thread patterns is that the first thread pattern 12 has a coarser thread than the second thread pattern 14 which is a finer thread. The point 16 is the point of initiation for insertion into a bone during an orthopedic procedure. To facilitate same, a pilot hole may be drilled in the bone but thereafter, because of the tapering nature of the first thread 12 , this portion is thereafter self-threading. Notice that the crest 70 for both first and second thread patterns are sharp. This allows cutting into the bone which typically has a harder exterior than the interior. By providing a coarser thread pattern for the first thread 12 , this thread will insert into the bone faster than the second thread pattern 14 . As a consequence, when the bone begins to be engaged by the second thread pattern, an axial compression of the bone occurs along the direction of the two arrow A. In addition, because of the thread geometry, the threads will exert a radially inwardly directed force along the direction of the double-ended arrows B. Whereas in the prior art, conventional fasteners induced radially outwardly spreading (the opposite direction from arrow B), the instant invention provides radially inwardly or a drawing force B as well as the compressive force A.
[0030] The threads 60 of fastener 10 for threads 12 and 14 are actually one continuous helically wound thread which begins at the ends and spirals towards the medial portion of shaft 32 as it migrates from the ends. Please see FIG. 3.
[0031] The threads 60 include a sharpened crest 70 defining a major diameter 62 of the threads and a root 80 defining a minor diameter 64 of the threads 60 . As shown in detail in FIG. 3, the threads 60 have an upper surface 66 which extends from a bottom edge 84 of the root 80 to the sharpened crest 70 . The threads 60 also include a lower surface 68 which extends from a top edge 82 of the root 80 to the sharpened crest 70 . Both the upper surface 66 and lower surface 68 angle toward the medial portion of the fastener as the surfaces 66 , 68 extend from the root 80 to the crest 70 .
[0032] In section, the surfaces 66 , 68 extend linearly from the root 80 to the sharpened crest 70 . However, as this contour is rotated helically about the threaded shaft 32 along with the threads 60 , the upper surface 66 and lower surface 68 take on a curved surface appearance. This appearance is similar to that which would be formed by a linear section of the surface of a cone with a tip of the cone oriented downward and the cone rotated and translated upward along a central axis thereof. The upper surface 66 and lower surface 68 thus have a curved surface in three dimensions similar to that of a cone, but a linear character when viewed in section.
[0033] The upper surface 66 extends from the root 80 to the sharpened crest 70 at an upper surface angle α diverging from a reference plane orthogonal to the central long axis 2 of the fastener. The upper surface angle α is preferably 20° but could be any angle between 0° and 90°. The lower surface 68 extends from the root 80 to the sharpened crest 70 at a lower surface angle β with respect to the reference plane. The lower surface angle β 0 is preferably 40° but could vary between 0° and 90°.
[0034] The upper surface angle α is preferably less than the lower surface angle β. In this way, the threads 60 are provided with greater thickness, and hence greater strength adjacent the minor diameter 64 than at the major diameter 62 and are thus more capable of bearing the loads experienced within the bone.
[0035] It is the angulation of the surfaces, especially upper surface 66 which encourages the radially inward force. When the upper and lower thread patterns are combined, axial compressive forces can be seen. Note the flat wall 54 of FIG. 3. This could replace point 16 and require a deeper pilot hole.
[0036] The second thread portion 14 has the same FIG. 3 geometry except that the threads 60 a are inverted, and as mentioned earlier are a finer thread (greater threads per inch axially) than the first thread portion 12 . In other words FIG. 3 would be viewed upside down for threads 14 .
[0037] [0037]FIG. 3A shows a section of thread with a pronounced taper. For thread pattern 14 , FIG. 3A would be viewed upside down and with a reverse taper to that shown.
[0038] A bottom 129 of cup 130 (FIG. 4) has clearance 22 which extends within an included arc preferably approaching 90 degrees to allow a wide range of fastener 10 rotation about arrow C. Rotation beyond this clearance 22 is prevented by cup wall structure 24 that survives both the clearance aperture 22 and the slot 134 that runs diametrically down two sides of the substantially cylindrical cup 100 . Free ends 138 of the cup 100 need the support a bolt 110 (FIG. 16) to: (first) press the rod 136 in place by (second) applying pressure to the disk 120 and retaining it by (third) uniting the free ends 138 .
[0039] The threads 60 of the threaded bolt 110 (FIGS. 7 and 16) are actually one continuous helically wound thread which begins at the bottom 54 and spirals up to the top 52 . While this single thread design is preferred, other arrangements including compound series of threads which wind helically together from the bottom 54 to the top 52 could also be utilized.
[0040] The threads 60 include a crest 170 defining a major diameter 62 of the threads and root 80 defining a minor diameter 64 of the threads 60 . As shown in detail in FIG. 7, the threads 60 have an upper surface 66 which extends from a bottom edge 84 of the root 80 to the upper edge 72 of crest 170 . The threads 60 also include a lower surface 68 which extends from a top edge 82 of the root 80 to a lower edge 74 of the crest 170 . Both the upper surface 66 and lower surface 68 angle upwards as the surfaces 66 , 68 extend from the root 80 to the crest 170 . Both the crest 170 and root 80 exhibit a constant distance from the central axis 2 between the top edge 82 and the bottom edge 84 . Compared to FIG. 3, crest 170 is blunt, while crest 70 is sharpened. Also, bolt 110 and thread 111 could have sharp contours like crest 70 (replacing crest 170 ) and vice versa.
[0041] In section, the surfaces 66 , 68 extend linearly from the root 80 to the crest 170 . However, as this contour is rotated helically about the threaded bolt 110 along with the threads 60 , the upper surface 66 and lower surface 68 take on a curved surface appearance. This appearance is similar to that which would be formed by a linear section of the surface of a cone with a tip of the cone oriented downward and the cone rotated and translated upward along a central axis thereof. The upper surface 66 and lower surface 68 thus have a curved surface in three dimensions similar to that of a cone, but a linear character when viewed in section.
[0042] The upper surface 66 extends from the root 80 to the crest 170 at an upper surface angle α diverging from a reference plane 4 orthogonal to the central axis 2 . The upper surface angle α is preferably 20 degrees but could be any angle between 0 degrees and 90 degrees. The lower surface 68 extends from the root 80 to the crest 170 at a lower surface angle β with respect to the reference plane 4 . The lower surface angle β is preferably 40 degrees but could vary between 0 degrees and 90 degrees.
[0043] The upper surface angle α is preferably less than the lower surface angle β such that a thickness of the threads 60 at the crest 170 is less than a thickness of the threads 60 between adjacent roots 80 . In this way, the threads are provided with greater thickness, and hence greater strength adjacent the minor diameter 64 than at the major diameter 62 and are thus more capable of bearing the loads experienced within the threaded bore 132 .
[0044] Referring now to FIG. 8, details of the threaded bore 132 on free ends 138 bore are shown. The bore is preferably substantially complemental in form to the threaded shaft of the bolt 110 . The bore includes threads T. The thread geometry of the bolt 110 and threads T draw free ends 136 of cup 130 together along arrow D.
[0045] [0045]FIG. 17 shows a fractured bone and the device 100 being applied. The fasteners 10 with discs 120 and the cups 130 are located such that the fasteners 10 are located in the bone, but the disc can rotate within clearance 22 as described. Recall the threads 12 , 14 axially compress and radially inwardly drawing in the bone. Next the rod 138 is placed within the slots 134 of the cups 130 .
[0046] The rod is shown as having a bend 165 to demonstrate the system's versatility. Next the bolts 110 are threaded into threads 111 in the free ends 138 of the cups 130 . As the bolts 110 bear on rod 136 , the rod 136 , disc 120 and fastener 10 become rigid. The free ends 138 also draw together tightly.
[0047] Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.
|
An orthopedic stabilization structure including a threaded fastener capable of articulation to accommodate various skeletal geometries, a rod, and a cup supporting said threaded fastener and said rod to be subsequently held in fixed position with respect to the skeletal structure.
| 0
|
FIELD OF THE INVENTION
The invention relates to the field of microbial enhanced oil recovery and bioremediation of subterranean contaminated sites. Specifically, it relates to methods of treating the toxic chemicals accumulated in subterranean sites adjacent to the water injection wells prior to introduction of microbial inocula for microbial enhanced oil recovery or bioremediation of these sites.
BACKGROUND OF THE INVENTION
Traditional oil recovery techniques which utilize only the natural forces present at an oil well site, allow recovery of only a minor portion of the crude oil present in an oil reservoir. Oil well site generally refers to any location where wells have been drilled into a subterranean rock containing oil with the intent to produce oil from that subterranean rock. An oil reservoir typically refers to a deposit of subterranean oil. Supplemental recovery methods such as water flooding have been used to force oil through the subterranean location toward the production well and thus improve recovery of the crude oil (Hyne, N.J., 2001, “Non-technical guide to petroleum geology, exploration, drilling, and production”, 2nd edition, Pen Well Corp., Tulsa, Okla., USA).
To meet the rising global demand on energy, there is a need to further increase production of crude oil from oil reservoirs. An additional supplemental technique used for enhancing oil recovery from oil reservoirs is known as Microbial Enhanced Oil Recovery (MEOR) as described in U.S. Pat. No. 7,484,560. MEOR, which has the potential to be a cost-effective method for enhanced oil recovery, involves either stimulating the indigenous oil reservoir microorganisms or injecting specifically selected microorganisms into the oil reservoir to produce metabolic effects that lead to improved oil recovery.
The production of oil and gas from subterranean oil reservoirs requires installing various equipment and pipelines on the surface or the subterranean sites of the oil reservoir which come in contact with corrosive fluids in gas- and oil-field applications. Thus, oil recovery is facilitated by preserving the integrity of the equipment needed to provide water for water injection wells and to convey oil and water from the production wells. As a result, corrosion can be a significant problem in the petroleum industry because of the cost and downtime associated with replacement of corroded equipment.
Sulfate reducing bacteria (SRB) microorganisms, which produce hydrogen sulfide (H 2 S), are amongst the major contributors to corrosion of ferrous metal surfaces and oil recovery equipment. These microorganisms can cause souring, corrosion and plugging and thus can have negative impact on a MEOR or a bioremediation process. Bioremediation refers to processes that use microorganisms to cleanup oil spills or other contaminants from either the surface or the subterranean sites of soil.
To combat corrosion, corrosion inhibitors which are chemicals or agents that decrease the corrosion rate of a metal or an alloy and are often toxic to microorganisms, are used to preserve the water injection and oil recovery equipment in such wells. In the practice of the present invention a water injection well is a well through which water is pumped down into an oil producing reservoir for pressure maintenance, water flooding, or enhanced oil recovery. The significant classes of corrosion inhibitors include compounds such as: inorganic and organic corrosion inhibitors. For example, organic phosphonates, organic nitrogen compounds, organic acids and their salts and esters (Chang, R. J. et al., Corrosion Inhibitors, 2006, Specialty Chemicals, SRI Consulting).
US2006/0013798 describes using bis-quaternary ammonium salts as corrosion inhibitors to preserve metal surfaces in contact with the fluids to extend the life of these capital assets.
U.S. Pat. No. 6,984,610 describes methods to clean up oil sludge and drilling mud residues from well cuttings, surface oil well drilling and production equipment through application of acids, pressure fracturing and acid-based microemulation for enhanced oil recovery.
WO2008/070990 describes preconditioning of oil wells using preconditioning agents such as methyl ethyl ketone, methyl propyl ketone and methyl tertiary-butyl ether in the injection water to improve oil recovery. Mechanisms such as modifying the viscosity of the oil in the reservoir and enlivening the heavy oil were attributed to this method.
US2009/0071653 describes using surfactants, caustic agents, anti-caking agents and abrasive agents to prevent or remove the build-up of fluid films on the processing equipment to increase the well's capacity.
Studies indicate that long-term addition of chemicals or agents used to control undesirable events such as corrosion, scale, microbial activities, and foam formation in the water supply of a water injection well does not lead to their accumulation in high enough concentrations to adversely affect the microorganisms used in MEOR (Carolet, J-L. in: Ollivier and Magot ed., “Petroleum Microbiology”, chapter 8, pages 164-165, 2005, ASM press, Washington, D.C.).
However, viability of microorganisms used in MEOR or bioremediation processes is a concern. It can be desirable to modify MEOR or bioremediation treatments such that the viability of microorganisms used is maintained throughout the process thus making them more effective.
SUMMARY OF THE INVENTION
The present disclosure relates to a method for improving the effectiveness of a MEOR or bioremediation process by detoxifying subterranean sites adjacent to oil wells, wherein the wells have been previously treated with corrosion inhibitors prior to inoculation of the microorganisms required for MEOR or bioremediation.
In one aspect, the present invention is an oil recovery method comprising the steps of:
a) treating a subterranean site in a zone adjacent to a water injection well with a detoxifying agent wherein, prior to the treatment, corrosion inhibitors and their degradation products have been adsorbed into the zone and have accumulated to concentrations that are toxic to microorganisms used in microbial enhanced oil recovery and/or bioremediation processes, and thereby have formed a toxic zone; and b) adding an inoculum of microorganisms for microbial enhanced oil recovery to the water injection well wherein the inoculum of microorganisms comprises Shewanella putrefaciens (ATCC PTA-8822);
wherein the corrosion inhibitor is an inorganic compound selected from the group consisting of chlorine, hypochlorite, bromine, hypobromide, chlorine dioxide, hydrazine, anthraquinone, phosphates, and salts containing chrome, molybdenum, zinc, nitrates, nitrites and sodium sulfite.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is the schematic representation of a water injection well and the subterranean sites adjacent to the water injection well. ( 1 ) is the flow of injection water into the well casing ( 7 ), ( 2 and 3 ) are rock layers, ( 4 ) is the perforations in the casing, ( 5 ) is the well bore, ( 6 ) is the face of the rock layer made by the well bore, ( 7 ) is the well casing, ( 8 ) is one side of the watered zone that is axi-symmetric with the injection well, shown by a dotted box in the rock layer ( 3 ).
FIG. 2 is the schematic of a model system used to simulate formation of a toxic zone. ( 9 ) is a long slim tube; ( 10 ) is a pressure vessel to constrain the slim tube; ( 11 and 12 ) are the opposite ends of the pressurized vessel; ( 13 ) is a pump; ( 14 ) is the feed reservoir; ( 15 ) is the water inlet for the pressure vessel; ( 16 ) is the back pressure regulator; ( 17 ) is the high pressure air supply; ( 18 ) is an inlet fitting connecting the slim tube inside the pressure vessel to the pump and pressure transducers; ( 21 ) is an outlet fitting connecting the slim tube inside the pressure vessel to the back pressure regulator and the low side of the differential pressure transducer; ( 19 ) is a differential pressure transducer; and ( 20 ) is an absolute pressure transducer.
FIG. 3 depicts titration of amine coated core sand; ♦ represent amine coated sand and □ represent first derivative of the titration curve (central differences).
FIG. 4 depicts titration of brine and core sand with 1N HCl; ▪ represent brine #1 with 10 grams of core sand; diamonds ♦ represent brine #1 only; represents the slope of brine #1 with 10 grams of core sand; and Δ represents the slope of brine #1 only.
FIG. 5 depicts titration of brine and core sand with 10% nitric acid; ♦ represent the concentration of amine observed in solution for a given pH.
FIG. 6 depicts titration of brine and core sand with 10% acetic acid; ♦ represent the concentration of amine observed in solution for a given pH.
DETAILED DESCRIPTION OF THE INVENTION
In one aspect, the present invention is a method for detoxifying the corrosion inhibitors and their degradation products in a subterranean site adjacent to a water injection well of an oil well site. Applicants have found that oil recovery processing aids—such as corrosion inhibitors, for example—can accumulate in the area adjacent to the water injection well and build to concentrations that are toxic to microorganisms used in MEOR or bioremediation. As the term is used herein, “detoxifying” or “detoxification of” a water injection site means removing or reducing the toxicity caused by corrosion inhibitors and their degradation products to microorganisms to allow their growth and activity of said microorganisms, used in MEOR or bioremediation.
For the purposes of the present invention, the term “toxic zone” refers to a subterranean site adjacent to the water injection well comprising toxic concentrations of agents such as corrosion inhibitors or their degraded products which have adverse effects on growth and metabolic activities of microorganisms used in MEOR and/or bioremediation. A toxic agent, as the term is used herein, is any chemical or biological agent that adversely affects growth and metabolic functions of microorganisms used in MEOR and/or bioremediation.
FIG. 1 is a schematic of a subterranean site adjacent to a water injection well. The injection water ( 1 ) flows into the well casing ( 7 ) which is inside the well bore ( 5 ) drilled through rock layers ( 2 and 3 ). A gap exists between the well casing ( 7 ) and the face ( 6 ) of the rock layer made by the well bore ( 5 ). Rock layer ( 2 ) represents impermeable rock above and below a permeable rock ( 3 ) that holds or traps the oil. The injection water ( 1 ) flows down the well casing ( 7 ) and passes through perforations in the casing ( 5 ) and into fractures ( 4 ) in the permeable rock ( 3 ). This injection water then flows through the permeable rock layer ( 3 ) and displaces oil from a watered zone ( 8 ) adjacent to the well bore. This zone extends radially out from the well bore ( 5 ) in all directions in the permeable rock layer ( 3 ). While the volume of permeable rock ( 3 ) encompassed by the dash line ( 8 ) is illustrated only on one side of the well bore it actually exists on all sides of the well bore. This watered zone represents the subterranean site adjacent to the water injection well.
Corrosion inhibitors that can accumulate to levels that are toxic to microorganisms used in MEOR are, for example: inorganic corrosion inhibitors such as chlorine, hypochlorite, bromine, hypobromide and chlorine dioxide. Those used to combat corrosion caused by SRB microorganisms include, but are not limited to: nitrates (e.g., calcium or sodium salts), nitrite, molybdate, (or a combination of nitrate, nitrite and molybdate), anthraquinone, phosphates, salts containing chrome and zinc and other inorganics, including hydrazine and sodium sulfite (Sanders and Sturman, chapter 9, page 191, in: “Petroleum microbiology” page 191, supra and Schwermer, C. U., et al., Appl. Environ. Microbiol., 74: 2841-2851, 2008).
Organic compounds used as corrosion inhibitors include: acetylenic alcohols, organic azoles, gluteraldehyde, tetrahydroxymethyl phophonium sulfate (THPS), bisthiocyanate acrolein, dodecylguanine hydrochloride, formaldehyde, chlorophenols, organic oxygen scavengers and various nonionic surfactants.
Other organic corrosion inhibitors include, but are not limited to: organic phosphonates, organic nitrogen compounds including primary, secondary, tertiary or quaternary ammonium compounds (hereinafter referred to generically as “amines”), organic acids and their salts and esters, carboxylic acids and their salts and esters, sulfonic acids and their salts.
Applicants have determined that corrosion inhibitors can accumulate by adsorption into or on the subterranean site (e.g., sand stone, unconsolidated sand or limestone) or into the oil that has been trapped in the oil reservoir subterranean site. Long-term addition of these chemicals results in their accumulation and formation of a toxic zone in subterranean sites adjacent to the water well with adverse effects on microbial inocula intended for MEOR and/or bioremediation applications.
A model system to simulate formation of a toxic zone can be used to study its effects on the survival of microorganisms. For example, a model system called a slim tube can be set up and packed with core sand from an oil well site. The model system as described herein can be set up using tubing, valves and fittings compatible with the crude oil or the hydraulic solution used that can withstand the range of applied pressure during the process. An absolute pressure transducer, differential pressure transducer and back pressure regulator for Example made by (Cole Plamer, Vernon hill, IL and Serta, Boxborough, Mass.) are required and are commercially available to those skilled in the art.
The model toxic zone can be established using solutions of amines and/or amine mixtures and flushing them through a tube packed with core sand from an oil reservoir. Other corrosion inhibitors suitable for use in constructing a model can comprise organic phosphonates or anthraquinone or phosphates. The concentration of the corrosion inhibitors used to create the model toxic zone may be from 0.01 to 100 parts per million.
Detoxification of the toxic zone involves degradation, desorption or dispersion of the accumulated toxic chemicals or agents using detoxifying agents. The term “detoxifying agent” therefore refers to any chemical that either disperses or destroys the toxic chemicals and agents described herein and renders them non-toxic to microorganisms.
Detoxification of the chemicals accumulated in the toxic zone may be achieved using a degradation agent. A degradation agent, as the term is used herein, is an agent that destroys or assists in the destruction of toxic agents found in the toxic zone. Degradation agents can include, for example, strong oxidizers that chemically react with corrosion inhibitors when added to the injection water and degrade them into less toxic or non-toxic products. Degradation agents include strong oxidizing agents such as, for example, nitrates, nitrites, chlorates, percholorates and chlorites.
Detoxification of the chemicals accumulated at the toxic zone may also be achieved using a dispersing agent. A “dispersing agent” as the term is used herein includes any chemical that lowers the pH of the solution, ionizes the amines and solubilizes them into the water during water flooding and allows for natural dispersion and diffusion to lower the concentration where it is no longer toxic to MEOR or bioremediation microorganisms. For example, amines are fairly non-reactive under mild conditions, however, they become ionized at lower pH. Thus treatment of the amines with an acid increases their solubility and releases them from oil and/or from rocks and disperses them from the toxic zone. The solubilized amines may therefore enter into the water flowing through the well. A combination of radial flow, dispersion and desorption may allow the solubilized amines to be diluted and dispersed over a large area (from at least 10 to about 200 feet (from at least 3 meters to about 7 meters)) of the oil well. Following dilution and dispersion of the amines over a much larger area, their concentrations within the subterranean site of the well would have been consequently reduced to non-toxic levels for MEOR or bioremediation microorganisms. However, even if the amines concentrations were still at toxic levels, the toxic zone in the subterranean site adjacent to the injector well will have become non-toxic to microorganisms. Thus, the microbial inoculum may pass through the subterranean site adjacent to the water injection well without encountering toxic levels of the amines.
In another embodiment, hydrogen peroxide may be added to the toxic zone, as both a degradation and a dispersing agent, from about 1,000 parts per million to 70,000 parts per million by volume of water. In another embodiment, perchlorates may be added, as both a degradation and a dispersing agent, from about 1 parts per million to about 10,000 parts per million.
In another embodiment, any acid capable of lowering the pH at least 1 unit less than the equivalence point of the amine (as measured in the Examples below) may be used. The acid used to ionize the amines may include, but is not limited to, nitric acid, acetic acid, oxalic acid, hydrofluoric acid, and hydrochloric acid. Acid may be added from about 0.1 weight % to about 20 weight % to the water that is being pumped into the toxic zone.
In a MEOR process, viable microorganisms are added to the water being injected into the water injection well. The term “inoculum of microorganisms” refers to the concentration of viable microorganisms added. These microorganisms colonize, that is to grow and propagate, at the subterranean sites adjacent to the water injection well to perform their MEOR.
Microorganisms useful for this application may comprise classes of facultative aerobes, obligate anaerobes and denitrifiers. The inoculum may comprise of only one particular species or may comprise two or more species of the same genera or a combination of different genera of microorganisms.
The inoculum may be produced under aerobic or anaerobic conditions depending on the particular microorganism(s) used. Techniques and various suitable growth media for growth and maintenance of aerobic and anaerobic cultures are well known in the art and have been described in “Manual of Industrial Microbiology and Biotechnology” (A. L. Demain and N. A. Solomon, ASM Press, Washington, D.C., 1986) and “Isolation of Biotechnological Organisms from Nature”, (Labeda, D. P. ed. p 117-140, McGraw-Hill Publishers, 1990).
Examples of microorganisms useful in MEOR in this application include, but are not limited to: Comamonas terrigena, Fusibacter paucivorans, Marinobacterium georgiense, Petrotoga miotherma, Shewanella putrefaciens, Pseudomonas stutzeri, Vibrio alginolyticus, Thauera aromatics, Thauera chlorobenzoica and Microbulbifer hydrolyticus.
In one embodiment an inoculum of Shewanella putrefaciens (ATCC PTA-8822) may be used to inoculate the slim tube test. In another embodiment Pseudomonas stutzeri (ATCC PTA8823) may be used to inoculate the slim tube. In another embodiment Thauera aromatica (ATCC9497) may be used to inoculate the slim tube.
The inoculum of microorganisms useful for bioremediation may comprise, but are not limited to, various species of: Corynebacteria, Pseudomonas, Achromobacter, Acinetobacter, Arthrobacter, Bacillus, Nocardia, Vibrio , etc. Additional useful microorganisms for bioremediation are known and have been cited, for example, in Table 1 of U.S. Pat. No. 5,756,304, columns 30 and 31.
The inoculum for injecting into the water well injection site may comprise one or more of the microorganisms listed above.
EXAMPLES
The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and make various changes and modifications to the invention to adapt it to various uses and conditions.
General Methods
Chemicals and Materials
All reagents, and materials used for the growth and maintenance of microbial cells were obtained from Aldrich Chemicals (Milwaukee, Wis.), DIFCO Laboratories (Detroit, Mich.), GIBCO/BRL (Gaithersburg, Md.), or Sigma Chemical Company (St. Louis, Mo.), unless otherwise specified.
Amines Analysis
Concentration of amines, in media and water, were analyzed by gas chromatography (GC). An Agilent Model 5890 (Agilent, Wilmington, Del.), GC equipped with a flame photoionization detector and a split/splitless injector, a DB-FFAP column (30 meter length×0.32 millimeter (mm) depth×0.25 micrometer particle size). The equipment had an Agilent ALS Autoinjector, 6890 Model Series with a 10 milliliter (ml) syringe. The system was calibrated using a sample of N,N-Dimethyl-1-Dodecaneamine (Aldrich). Helium was used as the carrier gas. A temperature gradient of 50 degrees Celsius (° C.) to 250° C. at 30° C. increase per minute (min) was used. Retention times (in minutes, min) for various chemicals of interest included: N,N-Dimethyl-1-Dodecaneamine (8.08 min); N,N-Dimethyl-1-Tetradecaneamine (8.85 min); N,N-Dimethyl-1-Hexadecane-amine (9.90 min); N,N-Dimethyl-1-Octadecaneamine (10.26 min) and N-Methyl,N-Benzyll-1-Tetradecaneamine (11.40 min).
Example 1
Establishing a Toxic Zone in Core Sand from an Oil Well Using a Mixture of Amines in a Model System
A sample of the sand obtained from the Schrader Bluff formation at the Milne Point Unit of the Alaska North Slope was cleaned by washing with a solvent made up of a 50/50 (volume/volume) mixture of methanol and toluene. The solvent was subsequently drained and then evaporated off the core sand to produce clean, dry, flow able core sand. This core sand was sieved to remove particles with less than one micrometer in size and was then packed tightly into a four foot (121.92 cm) long flexible slim tube ( 9 ) and compacted by vibration using a laboratory engraver. Both ends of the slim tubes were capped to keep the core sand in it. The complete apparatus is shown in FIG. 2 . Tubing that can sustain the amount of pressures used in the slim tube, was connected to the end caps. The slim tube ( 9 ) was mounted into the pressure vessel ( 10 ) with tubing passing through the ends ( 11 and 12 ) of the pressure vessel using pressure fittings ( 18 and 21 ). Additional fittings and tubing were used to connect the inlet of the slim tube ( 11 ) to a pressure pump ( 13 ) and a feed reservoir ( 14 ).
Additional fittings and tubing connected the inlet of the slim tube to an absolute pressure transducer ( 20 ) and the high pressure side of a differential pressure transducer ( 19 ). Fittings and tubing connected the outlet of the slim tube ( 12 ) to the low pressure side of a differential pressure transducer ( 19 ) and to a back pressure regulator ( 16 ). The signals from the differential pressure and the absolute pressure transducer were ported to a computer and the pressure readings were monitored and periodically recorded. The pressure vessel ( 10 ) around the slim tube was filled with water through a water port ( 15 ). This water was then slowly pressurized with air ( 17 ) to a pressure of about 105 per square inch (psi) (0.72 mega Pascal) while brine #1 from the feed reservoir ( 14 ) (Table 1) flowed through the slim tube and left the slim tube through the back pressure regulator ( 16 ). This operation was performed such that the pressure in the slim tube was always 5 to 20 psi (0.034-0.137 mega Pascal) below the pressure in the pressure vessel ( 10 ).
TABLE 1
Ingredients of Brine #1
(no nutrient brine - gram per liter (gr/L) of tap water
NaHCO 3
1.38
grams (gr)
CaCl 2 *6H 2 O
0.39
gr
MgCl 2 *6H 2 O
0.220
gr
KCl
0.090
gr
NaCl
11.60
gr
NaHCO 3
1.38
gr
Trace metals
1
ml
Trace vitamins
1
ml
Na 3 (PO 4 )
0.017
gr (=10 parts per million (ppm) PO 4 )
NH4Cl
0.029
gr (=10 ppm NH 4 )
Acetate
0.2
gr (200 ppm acetate)
The pH of brine #1 was adjusted to 7.0 with either HCl or NaOH and the solution was filter sterilized.
TABLE 2
Concentration of the amines added to Brine #1
NN-
NN-
NN-
N-methylN-
Dimethyl-1-
Dimethyl-1-
Dimethyl-
Benzyl-1-
Minor
other
Dodeca-
tetradeca-
Methane-
tetradeca-
amine
amine
neamine
neamine
thioamide ??
Caprolactam
neamine
Sample
PPM
PPM
PPM
PPM
PPM
PPM
PPM
Brine #1
25
124
23
1
0
0
2
w/amine
Once the pressure inside and outside the slim tube was established, one pore volume of the crude oil from an oil reservoir of the Milne Point Unit of the Alaskan North Slope was pumped into the slim tube. This process was performed in several hours (h). Once the crude oil had saturated the core sand in the slim tube and was observed in the effluent, the flow was stopped and the oil was allowed to age in the core sand for 3 weeks. At the end of this time, brine #1 was pumped through the slim tube at a rate of ˜1.5-3.5 milliliter per hour (ml/h) (˜1 pore volume every 20 h). Samples were taken from the effluent and the concentration of natural microflora in them was determined.
After 51 pore volumes of flow through the slim tube the concentration of natural microflora in the system was about 1×10 7 colony forming units per milliliter (CFU/ml). At this point, a mixture of amines (hereafter amines/brine mixture) was added at 150 ppm concentration to brine #1. The approximate composition of the mixture of amines (Table 2) consisted of 7 different amine components that were identified. Five were identified by Mass Spectrometry (Agilent Technologies, Inc. Santa Clara, Calif.) as N-N-dimethyl-1-dodecaneamine, N-N-dimethyl-1-tetradecane-amine, N-N-dimethyl-methane-thioamide, caprolactam and N-methyl-N-benzyl-1-tetradecaneamine. Two of the components were identified as amines but specific chemical formulas could not be assigned to them because the Mass Spectral Fragmentation patterns could not be deciphered. These are labeled in Table 2 as “minor amine” and “other amine”. Analysis of the effluent from the slim tube did not indicate presence of any amines in it. The experiment was continued by pumping 150 ppm of the mixture of amines in brine #1 through the slim tube.
After 77 pore volumes of the mixture of brine #1 with 150 ppm of mixture of amines was pumped into the slim tube no amines were observed in the effluent.
After 80 pore volumes of the mixture of brine #1 with 150 ppm of mixture of amines was pumped into the slim tube a total of about 1 gr of the mixture of amines had flowed through the slim tube. At this point, 80 ppm of amines was finally observed in the effluent of the slim tube. This very long delay in seeing the amines in the effluent means that virtually all the amines had been trapped in the slim tube. In addition, at this time, no natural microflora could be seen in the effluent indicating that the slim tube had become toxic enough to kill all existing microflora. At this point, pumping the amines-free brine #1 was started in an attempt to flush the amines out of the slim tube and to make it less toxic.
After 24 pore volumes of the amines-free brine #1 had been pumped through the slim tube, 51 ppm of amines was detected in the effluent. The slim tube was then inoculated with one pore volume of Shewanella putrefaciens (ATCC PTA-8822) at a concentration of approximately 1×10 9 CFU/ml. This inoculation was not allowed to remain in the slim tube. Instead, amines-free brine #1 was flushed through the slim tube immediately after the inoculation. Consequently the microbes resided in the slim tube for only a few hours during the transit through it. Thus, it was anticipated that the microorganisms' concentration in the effluent could be measured in the effluent eluting the slim tube. However, remarkably no microorganisms (representing about a 9 log kill) were detected in the slim tube effluent despite the short residence time of the inoculum in the slim tube. This experiment confirmed that a toxic zone had been established in the slim tube. In a continued attempt to detoxify the slim tube, brine #1 alone was continuously pumped through it.
After 79 pore volumes of the amines-free brine #1 had been pumped through the slim tube, the amines concentration in the effluent of the slim tube was measured at 30 ppm. The slim tube was inoculated with another pore volume of Shewanella putrefaciens (at 1×10 9 CFU/ml). The CFU/ml in an effluent sample was about 1×10 4 showing more than a 5 log kill of this microorganism had occurred immediately following inoculation. This experiment underlined the continued toxic effect of the amines despite extended washing of the tube with the amines-free brine #1 solution.
After 108 pore volumes of the amines-free brine #1 had been pumped through the slim tube, the amine concentration in the effluent was measured at 5 ppm. The slim tube was inoculated with an additional one pore volume of Shewanella putrefaciens containing 1×10 9 CFU/ml. The CFU/ml in the effluent sample of the slim tube immediately following inoculation indicated a 4-5 log kill of this microorganism despite the extended washing with the amines-free brine #1 and the decrease in the amines concentration in the effluent. These results further confirmed the continued toxic effect of the mixture of amines accumulated in the slim tube.
After 143 pore volumes of the amines-free brine #1 had been pumped through the slim tube one pore volume of an inexpensive odorless mineral spirits (OMS)(Parks OMS, Zinsser Co., Inc., Somerset Jew Jersey #2035 CAS #8052-41-3) was pumped through the slim tube in an attempt to remove the remaining mixture of amines. After this flush of OMS, pumping of amines-free brine #1 through the slim tube was continued.
After 149 pore volumes of amines-free brine #1 had been pumped through the slim tube, the amines concentration in the effluent was measured at 4 ppm and the slim tube was inoculated with an additional one pore volume of Shewanella putrefaciens (1×10 9 CFU/ml). A count of microorganisms in the sample of the slim tube's effluent showed a 2-3 log kill (99 to 99.9%) despite the OMS flush and the extended washing with the amines-free brine #1. These results confirmed that the toxic zone in the slim tube was still killing virtually all the microorganisms added to the tube.
After 168 pore volumes of the amines-free brine #1 had been pumped through the slim tube, one pore volume of a solution of 10% HCl in water was pumped through the slim tube to remove the amines. After this acid wash, the amines-free brine #1 was continuously pumped through the slim tube.
Following the acid wash treatment, an additional 2 pore volumes of the amines-free brine #1 was pumped through the slim tube and the amines concentration in the effluent was measured at 0.5 ppm. The slim tube was then inoculated with an additional one pore volume of Shewanella putrefaciens (1×10 9 CFU/ml). The CFU/ml in the effluent showed about a 0.4 log kill of this microorganism. These results underlined survival of more microorganisms following the acid wash of the slim tube and the effectiveness of using an acid to detoxify the toxic zone in the slim tube. Table 3 below summarizes results of the various tests described above.
TABLE 3
Summary of the amount of amine observed in the slim tube's effluent and
the fraction of the microorganisms killed (log kill) during residence in the
slim tube.
Total Pore
volume of fluid
ppm
pumped
amines
log kill
through slim
in the
after
tube
effluent
inoculating
51
0
0
131
80.5
nd
amines flood
stopped
155
51.1
9.6
210
29.5
5.3
(at
least)
239
4.7
4.5
(at
least)
274
OMS flooded
~1 pore volume
280
4.2
2.4
299
10% HCL flooded
for 1 PV
301
0.5
0.4
PV = pore volume;
nd = not detected
Example 2
Removal of N N-Dimethyl-1-Dodecanamine from Core Sand Through their Ionization at Low pH Using Hydrochloric Acid
38 milligrams (mg) of N N-Dimethyl-1-Dodecanamine (hereafter referred to as “the amine”) was added to 10.210 gr of Pentane. This solution was added to 10.1845 gr of specific sand layers (Oa and Ob) obtained from the Schrader Bluff formation of the Milne Point Unit of the Alaskan North slope. The oil content of the sand was first removed using a mixture of methanol and toluene (50/50, volume/volume) as solvent washes. The solvent mixture was subsequently evaporated off the core sand to produce clean, dry, flowable core sand. This sand was mixed with the amine and pentane solution to produce a slurry. This slurry was thoroughly mixed and the pentane was evaporated off leaving the amine on the sand (hereafter referred to as sand/amine mixture). 100 ml of brine #2 (Table 3) was added to the sand/amine mixture to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.4. The concentration of the amine in the water should have been 380 ppm if all the amine were dissolved in brine #2. Analysis of a sample of sand/amine/brine mixture by GC did not reveal the presence of any amines in the test sample (i.e., the amine conc. was ˜<1 ppm). The fact that the amine was not detected underlined its strong binding to the sand particles. 0.1 ml of 1 normal (N) HCl was added to this solution, and the pH and the amine concentration was measured again. This step was repeated several times and the analyses results are shown in both Table 4 and in FIG. 3 . Complete ionization and solubilization of the amine in the water was observed at pH below ˜6.0. This is a surprising finding since the pKa of HCl is −6.2 (Langes Handbook of Chemistry, 14 th edition, page 8.14, 1992, McGraw-Hill, Inc., New York). Therefore, the concentration of the HCl required for this step to completely ionize the amine and removed it from the toxic core sand may be further reduced several orders of magnitude from the 10% concentration used in this example. The data underlines the remarkable efficiency of an acid at ionizing and removing the amine from the sand.
TABLE 3
Composition of brine #2 (gr/L of deionized water)
NaHCO 3
1.38
gr
CaCl 2 *6H 2 O
0.39
gr
MgCl 2 *6H 2 O
0.220
gr
KCl
0.090
gr
NaCl
11.60
gr
TABLE 4
Amine concentration measured in Example 2
N-N-
First
dimethyl-1-
derivative
dodeanamine
(change in
(ppm) in slim
amine/change
1N HCl
sample
tube effluent
in pH)
pH
(ml)
Amine titrate st
0.00
8.14
0.00
Amine titrate 1
46.41
63.75
7.37
0.10
Amine titrate 2
59.29
63.42
7.21
0.10
Amine titrate 3
67.97
24.34
7.03
0.10
Amine titrate 4
74.38
160.35
6.59
0.10
Amine titrate 5
212.28
412.18
6.13
0.10
Amine titrate 6
288.72
679.86
6.07
0.10
Amine titrate 7
273.47
−148.78
6.04
0.05
Amine titrate 8
275.33
119.35
5.98
0.05
Amine titrate 9
303.31
65.90
5.79
0.05
Amine titrate 10
314.21
15.17
5.39
0.05
Amine titrate 11
328.48
3.24
4.13
0.05
Amine titrate 12
321.33
11.80
3.19
0.05
Amine titrate 13
342.88
47.42
2.91
0.05
Amine titrate 14
342.67
−6.52
2.74
0.05
Amine titrate 15
340.92
79.86
2.61
0.05
Amine titrate 16
369.02
80.22
2.41
0.10
Amine titrate 17
368.19
2.25
2.27
0.10
Amine titrate 18
369.54
7.51
2.18
0.10
Amine titrate 19
369.47
0.12
2.10
0.10
Amine titrate 20
369.56
2.04
0.10
Example 3
Capacity of Core Sand to Neutralize Acid
A. Titration of Brine #2 in the Absence of Core Sand
The intent of this experiment was to determine the capacity of the core sand described in Example 2 to neutralize the HCl intended to ionize the amine accumulated in the sand.
To set up a control test, 100 ml of brine #2 was titrated with 1N HCl to initial pH of 8.1. An aliquot (0.1 ml) of 1N HCl was added to the brine #2 and the pH was measured. The HCl addition was repeated several times and the pH was measured after each addition. Results of these analyses are shown in both Table 5 and in FIG. 4 . The data indicated that about 2.25 milliequivalents of HCl were needed to achieve the equivalence point of about pH 4 corresponding to about 100% recovery of the carbonate present in brine #2.
TABLE 5 Titration of synthetic injection brine #2 in the absence of the amine First derivative of 1N HCl sample pH pH (ml) Addition 1 8.10 0.00 Addition 2 7.67 0.73 0.10 Addition 3 7.37 0.49 0.10 Addition 4 7.18 0.35 0.10 Addition 5 7.02 0.29 0.10 Addition 6 6.89 0.23 0.10 Addition 7 6.79 0.21 0.10 Addition 8 6.68 0.19 0.10 Addition 9 6.60 0.17 0.10 Addition 10 6.51 0.15 0.10 Addition 11 6.45 0.15 0.10 Addition 12 6.36 0.18 0.10 Addition 13 6.27 0.18 0.10 Addition 14 6.18 0.18 0.10 Addition 15 6.09 0.17 0.10 Addition 16 6.01 0.17 0.10 Addition 17 5.92 0.18 0.10 Addition 18 5.83 0.19 0.10 Addition 19 5.73 0.33 0.10 Addition 20 5.50 0.32 0.10 Addition 21 5.41 0.33 0.10 Addition 22 5.17 0.74 0.10 Addition 23 4.67 1.94 0.10 Addition 24 3.23 1.86 0.10 Addition 25 2.81 0.62 0.10 Addition 26 2.61 0.36 0.10 Addition 27 2.45 0.25 0.10 Addition 28 2.36 0.17 0.10 Addition 29 2.28 0.10
B. Titration of Brine #2 with Core Sand
100 ml of brine #2 plus 10 gr of the same core sand (brine/sand mixture) used in Example 2, was titrated with 1N HCl. The initial pH of the brine/sand mixture was 7.88. 0.1 ml aliquots of 1N HCl were added to this mixture repeatedly, and the pH was measured after each HCl addition. The results shown in both Table 6 and in FIG. 4 indicated that addition of 0.3 milliequivalents of HCl was needed to achieve the equivalence point with 10 gr of sand present. The data obtained in this experiment underlines the slight capacity of the core sand to neutralize the added HCl. Consequently a small concentration of an acid, such as HCl, ionized the amine associated with the core sand without getting neutralized by reaction with the sand.
TABLE 6
Titration of brine #2 and 10 gr of core sand
Brine contained
1.87 gr NaHCO 3
Used 10.103 gr
2.60 ml of 1N HCL at
of core sand
ml 1N
Sample
pH
Slope of pH (first derivative)
HCl
1
7.88
0.00
2
7.55
0.53
0.10
3
7.35
0.36
0.10
4
7.19
0.30
0.10
5
7.05
0.24
0.10
6
6.95
0.20
0.10
7
6.85
0.18
0.10
8
6.77
0.18
0.10
9
6.67
0.17
0.10
10
6.60
0.14
0.10
11
6.53
0.14
0.10
12
6.46
0.13
0.10
13
6.40
0.12
0.10
14
6.34
0.13
0.10
15
6.27
0.13
0.10
16
6.21
0.13
0.10
17
6.14
0.15
0.10
18
6.06
0.16
0.10
19
5.98
0.16
0.10
20
5.90
0.17
0.10
21
5.81
0.21
0.10
22
5.69
0.29
0.10
23
5.52
0.34
0.10
24
5.35
0.45
0.10
25
5.07
0.80
0.10
26
4.55
1.14
0.10
27
3.93
1.13
0.10
28
3.42
0.86
0.10
29
3.07
0.52
0.10
30
2.90
0.33
0.10
31
2.74
0.24
0.10
32
2.66
0.29
0.10
33
2.45
0.34
0.20
34
2.32
0.23
0.20
35
2.22
0.18
0.20
36
2.14
0.20
Example 4
Removal of N-N-Dimethyl-1-Dodecanamine from Core Sand Through their Ionization at Low pH Using 10% Nitric Acid
The procedure outlined in Example 2 was used to produce the sand/amine mixture except that 519 mg of the amine, 10 gr of Pentane. and 60.062 gr of sand from the Oa and Ob layers were used. 29.065 gr of this sand/amine mixture was added to 100 ml of brine #2 (Table 3) to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.28. The concentration of the amine in the water should have been about 2000 ppm if all the amine was dissolved in brine #2. Instead, analysis of a sample of brine #2 in contact with the sand/amine/brine mixture as described above showed that the amine concentration was ˜85 ppm, i.e., far less than what was expected. The fact that only a small amount of the amine was detected in brine #2 underlined the strong binding of the amine to the sand particles. 0.1 ml of 10 weight percent (wt %) nitric acid in water was added to this solution, and the pH and the amine concentration were measured again. This step was repeated several times and the analyses results are shown in both Table 7 and in FIG. 5 . Complete ionization and solubilization in the water of the amine was observed at a pH below ˜6.7. This is a surprising finding since the pKa of nitric acid is −1.37 (Langes Handbook of Chemistry, 14 th edition, page 8.15, 1992, McGraw-Hill, Inc., New York), the concentration of the nitric acid required for this step may be further reduced several orders of magnitude from the 10 wt % used in this experiment without any negative impact on removal of the amines from the core sand.
TABLE 7
Amine concentration measured in Example 4
ppm N-N-
dimethyl-1-
sample
dodeanamine
pH
ml 10% HNO 3
start
85
8.28
0
1
110
8.13
0.1
2
211
7.72
0.1
3
216
7.42
0.1
4
235
7.25
0.1
5
540
7.2
0.1
6
745
7.29
0.1
7
1153
7.33
0.1
8
1210
7.29
0.1
9
1327
7.18
0.1
10
1315
7.11
0.1
11
1413
6.99
0.1
12
1667
6.85
0.1
13
1897
6.73
0.1
14
1853
6.64
0.1
15
1858
6.59
0.1
16
1788
6.28
0.2
17
1822
5.8
0.2
18
1975
3.46
0.2
Example 5
Removal of N-N-Dimethyl-1-Dodecanamine from Core Sand Through its Ionization at Low pH Using 10% Acetic Acid
The same procedure outlined in Example 4 was repeated here to produce the sand/amine mixture. 30.85 grams (gr) of the sand/amine mixture was added to 100 ml of brine #2 (Table 3) to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.52. The concentration of the amine in the water should have been about 2000 ppm if all the amine were dissolved in brine #2. Instead, analysis of brine #2 in contact with the sand/amine/brine mixture, as described above, showed that the amine concentration was ˜67 ppm, i.e., far less than what was expected. The fact that only a small amount of the amine was detected in the brine #2 underlined the strong binding of the amine to the sand particles. 0.1 ml of 10 wt % acetic acid was added to this solution, and the pH and the amine concentration were measured again. This step was repeated several times and the analyses results are shown in both Table 8 and in FIG. 6 . Complete ionization and solubilization in the water of the amine was observed at pH below ˜6.7. This is a surprising finding since the pKa of acetic acid is 4.756 (Langes Handbook of Chemistry, 14 th edition, page 8.19, 1992, McGraw-Hill, Inc., New York). Consequently, the concentration of the acetic acid required for this step may be further reduced significantly from what was used in this example without any negative impact on removal of the amine from the core sand.
The observations described above illustrate that a weak organic acid, like acetic acid can be as effective as a strong inorganic acid, like hydrochloric acid, at ionizing and separating the amines from the toxic core sand. It can therefore be concluded that to remove the toxic zone from a subterranean site, any acid that decreases the pH of a solution below about 6.7 can be used.
TABLE 8
Amine concentration measured in Example
ppm N-N-
dimethyl-1-
sample
dodeanamine
pH
ml 10% acetic acid
start
67
8.52
0
1
63
8.01
0.1
2
107
7.41
0.1
3
215
7.4
0.1
4
497
7.37
0.1
5
512
7.23
0.1
6
969
7.12
0.1
7
1239
6.98
0.1
8
1453
6.89
0.1
9
1583
6.75
0.1
10
1579
6.56
0.1
11
1616
6.39
0.1
12
1759
6.4
0.1
13
1736
6.02
0.2
14
1718
5.4
0.2
15
1743
5.04
0.2
16
1931
4.86
0.2
17
1995
4.73
0.2
18
1913
4.61
0.2
19
1881
4.52
0.2
20
1837
4.43
0.2
21
1885
4.36
0.3
|
A method to improve the effectiveness of MEOR or bioremediation processes. In this method toxic chemicals accumulated in subterranean sites adjacent to the water injection wells are either dispersed or removed prior to introduction of microbial inocula for enhanced microbial oil recovery or bioremediation of these sites.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Division of application Ser. No. 11/089,910, filed Mar. 24, 2005 now U.S. Pat. No. 7,009,107, which is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-82377, filed Mar. 22, 2005, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic circuit unit built in small-sized electronic apparatuses such as mobile phones and PDA (Personal digital Assistants), and to its shield structure.
2. Description of the Related Art
In general, small-sized electronic apparatuses such as mobile phones and PDA have a built-in electronic circuit unit, which is mounted with many circuit devices on a printed circuit board. The circuit devices include the following circuit device groups. One is a circuit device group such as CPU (Central Processing Unit) and DSP (digital signal Processor) radiating a noise. Another is a circuit device group such as radio circuit, which is easy to receive an influence by noise. In the foregoing circuit device groups, the noise radiated from the circuit device group such as CPU gives an influence to the circuit device group such as radio circuit depending on the positional relationship. As a result, this is very unfavorable because radio transmitting and receiving performance is reduced.
Conventionally, the following structure has been employed. For example, two frames produced by sheet metal processing are prepared. The circuit device group radiating the noise is enclosed with one of two frames; on the other hand, the circuit device group readily receiving the influence by noise is enclosed with the other thereof. The structure described above is given, and thereby, each frame functions as a shield case; therefore, the influence by the noise is reduced between the foregoing circuit device groups.
However, if the foregoing two frames are located separately from each other, a clearance area for repair must be secured between these frames. For this reason, these frames must be arranged with a given distance or more. As a result, the electronic circuit unit is inevitably configured into a large size. This is difficult to meet the requirements such as miniaturization of electronic apparatus and high packaging density of circuit device resulting from high function of apparatus.
Moreover, the shield structure given below has been proposed. According to the shield structure, a partition plate is provided in a rectangular frame to form two independent rooms. The foregoing two rooms each receive the circuit device group radiating the noise and the circuit device group readily receiving the influence by noise. The technique is detailedly disclosed in JPN. PAT. APPLN. KOAKI Publication No. 2001-144487.
However, according to the foregoing shield structure, the frame is configured to a large size. If the frame is produced using sheet metal processing, the flatness of the frame is reduced. This is a factor of causing packaging failure when the frame is mounted on a printed circuit board. Moreover, if the upper opening portion of the frame is attached with a cover, the frame and the cover are formed into a large size; for this reason, a gap is readily formed between the frame and the cover. This is a factor of reducing the uniformity of isolation characteristic between circuit devices.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing circumstances. An object of the present invention is to provide an electronic circuit unit, which prevents a reduction of packaging quality by the scale-up of a frame, and enables high density of device packaging while securing a necessary clearance area, and to its shield structure.
In order to achieve the foregoing object, according to one aspect of the present invention, there is provided an electronic circuit unit and its shield structure. A first frame is arranged on a printed circuit board mounted with a first circuit radiating a noise and a second circuit having a need to protect it from the noise to enclose the first circuit. A second frame is prepared in a state of removed one of several sides forming the frame, which is faces the side of the first frame. The second frame is arranged on the printed circuit board to enclose the second circuit with a given clearance area with respect to one side of the first frame.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a perspective view showing the shield structure of a first shield case of an electronic circuit unit according to one embodiment of the present invention;
FIG. 2 is a perspective view showing the shield structure of a second shield case of the electronic circuit unit according to one embodiment of the present invention;
FIG. 3 is a top plan view to explain the relationship in arrangement between the first and second shield cases of the electronic circuit unit according to one embodiment of the present invention;
FIG. 4 is a top plan view to explain the electronic circuit unit shown in FIG. 1 to FIG. 3 and the effect of the shield structure;
FIG. 5 is a top plan view to explain the electronic circuit unit shown in FIG. 1 to FIG. 3 and the effect of the shield structure;
FIG. 6 is a perspective view showing the shield structure of a second shield case of the electronic circuit unit according to another embodiment of the present invention; and
FIG. 7 is a cross-sectional view to explain the relationship in arrangement between the first shield case of the electronic circuit unit according to one embodiment of the present invention and the second shield case shown in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the accompanying drawings.
An electronic circuit unit according to one embodiment of the present invention includes first and second shield cases. The first shield case receives circuit devices radiating a noise, and the second shield case receives circuit devices having a need to protect them from the noise.
The circuit devices radiating a noise include circuit devices forming a digital circuit such as CPU (Central Processing Unit) and DSP (Digital Signal Processor). On the other hand, the circuit devices having a need to protect them from the noise include high frequency circuit devices such as LSI (Large Scale integrated Circuit) forming a radio circuit.
As shown in FIG. 1 , the first shield case is composed of a metal frame 1 and a metal cover 2 attached to the metal frame 1 . The metal frame 1 comprises a rectangular frame having four sides 11 to 14 , and is produced using sheet metal processing. A pair of mutually opposed sides 11 and 13 of the metal frame 1 is connected via a bridge member 15 . The bridge member 15 functions as a reinforcement member for protecting the metal frame 1 from deformation. The bridge member 15 is provided with an adsorption member 16 at the central portion. The adsorption member 16 is used for lifting up the metal frame 1 by a robot arm when the metal frame 1 is mounted on a printed circuit board 10 .
The metal frame 1 is positioned and fixed on the printed circuit board 10 to enclose circuit devices (not shown) radiating a noise. Soldering is used as the fixing means. In FIG. 1 , reference numerals 17 denote the soldering pattern.
The metal cover 2 is produced using sheet metal processing like the metal frame 1 . The metal cover 2 closes the metal frame 1 so that noise radiated from circuit devices received in the metal frame 1 does not externally leak from there. The metal cover 2 is attached to the upper opening portion of the metal frame 1 .
As illustrated in FIG. 2 , the second shield case is composed of a metal frame 3 and a metal cover 4 attached to the metal frame 3 . The metal frame 3 is produced using sheet metal processing in a manner that one of four sides forming a rectangular frame is removed. A pair of mutually opposed sides 31 and 33 of the metal frame 3 is connected via a bridge member 35 . The bridge member 35 functions as a reinforcement member for protecting the metal frame 3 from deformation. The bridge member 35 is provided with an adsorption member 36 at the central portion. The adsorption member 36 is used for lifting up the metal frame 3 by a robot arm when the metal frame 3 is mounted on a printed circuit board 10 like the metal frame 1 described before.
The metal frame 3 is positioned and fixed on the printed circuit board 10 to enclose circuit device groups 6 having a need to protect them from a noise. Soldering is used as the fixing means. In FIG. 2 , reference numerals 37 denote the soldering pattern.
The metal cover 4 is produced using sheet metal processing like the metal frame 3 . The metal cover 4 closes the metal frame 3 to prevent a noise radiated from circuit devices received in the metal frame 1 from intruding into the metal frame 3 and from giving an influence to the circuit device group 6 . The metal cover 4 is attached to the upper opening portion of the metal frame 3 .
The foregoing metal frames 1 and 3 are arranged on the printed circuit board 10 in the following manner. FIG. 3 is a top plan view to explain the arrangement relationship. More specifically, the metal frame 3 is arranged so that the removed side is opposed to the side 12 of the metal frame 1 . In this case, the metal frame 3 is positioned opposing to the metal frame 1 with a distance L 2 . The distance L 2 is given, and thereby, a clearance area is secured between the metal frames 1 and 3 . The clearance area is used for repairing packaging (mounting) failure relevant to the metal frames 1 and 3 .
As described above, one side of the metal frame 3 forming the second shield case is removed. By doing so, the clearance area required for repair is secured between the metal frames 1 and 3 while the packaging distance of circuit devices 5 and 6 is made small. As a result, circuit device packaging density is enhanced in the printed circuit board 10 having a limited packaging area. In other words, it is possible to meet the requirements such as miniaturization and high packaging density in the electronic circuit unit.
For example, metal frames 1 and 7 formed into a frame shape are used as the first and second shield cases, respectively, as depicted in FIG. 4 . In this case, the packaging distance must be set considering the thickness of the sides of both metal frames 1 and 7 as seen from a wide distance L 3 in FIG. 4 . This is a factor of causing a reduction of the packaging density.
According to this embodiment, the metal frames 1 and 3 are produced separately from each other. Thus, the flatness of these metal frames 1 and 3 is enhanced. As a result, it is possible to reduce packaging failure cased when the metal frames 1 and 3 are mounted on the printed circuit board 10 . This contributes to improving the yield and the shield effect.
Moreover, the metal covers 2 and 4 are produced separately from each other. Thus, the flatness of these metal covers 2 and 4 is enhanced. As a result, a gap is hard to be formed between the frame and cover in a state that the covers 2 and 4 are attached to the metal frames 1 and 3 . Therefore, this contributes to enhancing uniformity in isolation characteristic between circuit devices 5 and 6 .
If the first and second shield cases are each composed of one rectangular frame and its cover, the frame and the cover are formed into a large scale. For this reason, the flatness of the frame and the cover is reduced. As a result, a gap is readily formed between the frame and the printed circuit board and between the frame and the cover. This is a factor of reducing isolation characteristic between circuit devices.
For example, a rectangular metal frame 8 having four sides 81 to 84 is prepared as seen from FIG. 5 . A partition plate 85 is provided in the metal frame 8 to form two independent rooms 86 and 87 . These rooms 86 and 87 receive a circuit device group radiating a noise and a circuit device group easy to receive an influence by noise, respectively. In FIG. 5 , a reference numeral 9 denotes a metal cover, and a reference numeral 88 denotes a soldering pattern for mounting the metal frame 8 on a printed circuit board.
If the foregoing shield case is produced using sheet metal processing, both frame 8 and cover 9 are made into a large scale. For this reason, the flatness is reduced; as a result, uniformity of isolation characteristic is not obtained as described before.
According to this embodiment, mutually opposing sides of the metal frames 1 and 3 are connected via the bridge members 15 and 35 . Therefore, the structural strength of these metal frames 1 and 3 is enhanced, thereby reducing packaging failure of the metal frames 1 and 3 and enhancing the shield effect. Moreover, it is possible to improve the reliability of an electronic circuit unit.
According to this embodiment, the foregoing bridge members 15 and 35 are provided with the adsorption members 16 and 36 , respectively. Thus, these metal frames 1 and 3 are lifted up using a robot arm when mounting them on the printed circuit board 10 . By doing so, the metal frames 1 and 3 are automatically mounted.
The present invention is not limited to the foregoing embodiment. For example, at least one of the metal covers 2 and 4 shown in FIG. 1 and FIG. 2 may be provided with an extended portion. For example, as shown in FIG. 6 , a cover 40 including an extended portion 41 may be attached to the metal frame 3 according to another embodiment of the present invention. The extended portion 41 comprises a flange or protrusion. When the metal covers 2 and 40 are attached to the metal frames 1 and 3 , the extended portion 41 is overlapped with the metal cover 2 , as shown in FIG. 7 . The structure described above is given, and thereby, the metal covers 2 and 40 are electrically integrated. This serves to further enhance the shield effect. The metal cover 40 may be attached to the metal frame 1 instead of to the metal frame 3 .
In the foregoing embodiment, the metal frames 1 and 3 each comprise a rectangular shape having four sides. In this case, the metal frames 1 and 3 may each comprise a polygon frame having four sides or more. If several sides of the metal frame 1 are opposed to those of the metal frame 3 , these opposed sides may be removed.
Besides, various modifications of the features given below may be made within the scope without diverging from the subject matter of the present invention. The features are as follows:
Structure and shape of the printed circuit board;
Shape and structure of first and second frames and covers;
Presence, position and shape of the bridge member; and
Kind of a first circuit radiating a noise and a second circuit having a need to protect it from the noise
In short, the present invention is not limited to the foregoing embodiment. In the wording stage, components may be modified within the scope without diverging from the subject matter of the invention. Several components disclosed in the foregoing embodiment are properly combined, and thereby, various inventions are formed. For example, some components may be deleted from all components disclosed in the embodiment. Components relevant to different embodiment may be properly combined.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
|
A first frame is arranged on a printed circuit board to enclose a first circuit that radiates a noise. The printed circuit board also has mounted thereon a second circuit that has a need to be protected from the noise. A second frame is arranged on the printed circuit board to enclose the second circuit. The second frame is separated from one side of the first frame by a given clearance area, and the second frame has an open side facing the one side of the first frame.
| 8
|
FIELD OF THE INVENTION
The present invention generally relates to online gaming computer systems, and more particularly to a method and system for preventing cheating on online gaming computer systems.
DISCUSSION OF THE BACKGROUND
In recent years, online gaming has seen a dramatic increase in popularity. For example, in the year 2000, computer and video game sales in the U.S. were estimated at 6 billion dollars, with 219 million computer and video games sold and with a majority of the games including an online play capability. The popularity of online gaming will only increase in the future. However, as online gaming popularity increases, so do the number of players employing various types of cheats, hacks, and exploits.
Cheating in online games, defined as an attempt by a player to gain an unfair advantage over other players through exploitation of bugs in or manipulation or hacking of online gaming software, is a widespread and serious problem that negatively affects the level of entertainment and enjoyment legitimate or non-cheating players get from playing online games. Most online games use an architecture involving a game client program or software, including the client-side and display code, which is activated and interfaced by the player, and a game server program or software, which allows a number of clients to interact with each other in an online gaming environment.
There have been various programs or software developed to aid in the detection and identification of cheating players on individual game servers. However, such programs are easily bypassed, so that cheaters can continue cheating during online games. Therefore, there is a need for a method and system that can prevent cheating on online gaming computer systems, even for cheaters that try to circumvent cheat detection programs running on individual game servers.
SUMMARY OF THE INVENTION
The present invention includes recognition that while cheat detection and/or game server are may allow a server administrator to remove or permanently ban detected or suspected cheaters from a game server, this by itself is not a complete solution to the cheating problem. For example, game servers are typically operated by multiple independent entities or individuals not affiliated with each other and with no higher oversight authority. As a result, individual game servers themselves are often the highest authority to which a cheating player must answer. As there can be thousands or tens of thousands of separate game servers available for a player to join, a cheating player is able to simply join a game server from which the cheating player has been banned in order to continue cheating and thereby circumvent any cheat detection performed on the other game servers. Therefore, there is a need for a method and system that prevent cheating on online gaming computer systems, even for cheaters that try to circumvent cheat detection programs running on individual game servers by jumping from game server to game server.
The above and other needs are addressed by the present invention, which provides an additional level of authority, above the individual game servers, via a master database of cheaters that resides on one or more master servers and with which individual game servers communicate to transmit cheaters banned on the individual game servers and to receive a master list of cheaters aggregated from the individual game servers. In this way, once a cheater is banned on one game server, information identifying the cheater is transmitted to the master databases of the master servers for distribution to the other game servers. Advantageously, cheaters can no longer move from game server to game server in an attempt to continue cheating.
Accordingly, one aspect of the present invention relates to a method, system, and software for preventing cheating during online gaming on a first computer system, including receiving information regarding cheaters detected during online gaming gathered by a second computer system; and making the received information available to the first computer system. Advantageously, a cheater identified on the second computer system is prevented from online gaming on the first computer system.
Another aspect pertains to a method, system, and software for preventing cheating during online gaming, including receiving information regarding cheaters detected during online gaming from a first computer system; and transmitting information regarding cheaters detected during online gaming gathered from a plurality of online gaming computer systems to the first computer system. Advantageously, cheaters identified on the plurality of online gaming computer systems are prevented from online gaming on the first computer system.
Still other aspects, features, and advantages of the present invention are readily apparent the following detailed description, simply by illustrating a number of particular 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 several details can be modified in various respects, all without departing from the spirit and 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
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 is a block diagram depicting an online gaming cheater prevention system, according to an embodiment of the present invention;
FIG. 2 is a flowchart depicting processes performed by an exemplary cheater detection program;
FIG. 3 is a flowchart depicting processes performed by an exemplary cheater prevention program;
FIG. 4 is a flowchart depicting processes performed by an exemplary cheater prevention program; and
FIG. 5 is an exemplary computer system, which may be programmed to perform one or of the processes described with respect to FIGS. 1–4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An online gaming cheater prevention system and method are described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It is apparent to one skilled in the art, however, that the present invention may be practiced without these specific details or with an equivalent arrangement. In some instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, there is illustrated an online gaming cheater prevention system 100 , according to an embodiment of the present invention.
In FIG. 1 , generally, the cheater prevention system 100 provides for centralization and sharing of a master file 117 of identified online gaming cheaters. The system 100 includes, for example, a cheating prevention Server Module, including one or more master servers 101 and master databases 107 , and a cheater prevention server program or software 111 . The system 100 further includes, for example, a cheating prevention Client Module, including one or more individual game servers 103 , a cheater prevention client program or software 113 , and a cheat detection program 115 .
The master server 101 communicates with the master database 107 for storing information about identified cheating players, for example, including Internet Protocol (IP) addresses of the cheating players, in-game names or handles of the cheating players, unique online gaming identifications (IDs, e.g., WonIDs used in several popular online games, etc.) of the cheating players, etc. The cheater prevention server program 111 running on the master server 101 handles the connection with the cheater prevention client programs 113 running on the game servers 103 and interacts with the master database 107 . The cheater prevention client program 113 and the cheat detection or anti-cheat program 115 reside on the individual game servers 103 .
The master database 107 receives instructions (e.g., database update instructions, database query instructions, etc.) from the cheater prevention server program 111 . The master database 107 also receives, via the cheater prevention server program 111 , new cheater entries or information 121 extracted by the cheater prevention client programs 113 from cheater log files 119 of cheaters detected on and/or banned from the game servers 103 . Accordingly, the master server 101 communicates with the master database 107 and the cheater prevention server program 111 . The game servers 103 provide online game connectivity for one or more online gaming clients 105 .
The software portion of the cheater prevention Client Module resides on the game servers 103 and includes the cheat detection and/or logging program 115 (e.g., HLGuard, CSGaurd, etc.) and the cheater prevention client program or software 113 . The cheater prevention client program 113 provides connectivity between the cheater prevention client program 113 of the Client Module and the cheater prevention server program 111 of the Server Module.
Accordingly, the devices and subsystems of the cheater prevention system 100 of FIG. 1 can include, for example, any suitable servers, workstations, personal computers (PCs), laptop computers, PDAs, Internet appliances, set top boxes, modems, handheld devices, telephones, cellular telephones, wireless devices, other devices, etc., capable of performing the processes of the embodiments of the present invention. The devices and subsystems can communicate with each other using any suitable protocol and can be implemented using the computer system 500 of FIG. 5 , for example. One or more interface mechanisms can be used in the system 100 including, for example, Internet access, telecommunications in any form (e.g., voice, modem, etc.), wireless communications media, etc.
Accordingly, communications network 123 connecting the master sever 101 with the game servers 103 and communications network 125 connection the game servers 103 with the online gaming clients 105 can include, for example, wireless communications networks, cellular communications networks, G3 communications networks, Public Switched Telephone Networks (PSTNs), Packet Data Networks (PDNs), the Internet, intranets, etc. In addition, the communications networks 123 and 125 can be the same or different networks, as will be appreciated by those skilled in the relevant art(s).
It is to be understood that the system 100 of FIG. 1 is for exemplary purposes, as many variations of the specific hardware used to implement the embodiments of the present invention are possible, as will be appreciated by those skilled in the relevant art(s). For example, the functionality of the devices and the subsystems of the system 100 can be implemented via one or more programmed computer systems or devices.
To implement such variations as well as other variations, a single computer system (e.g., the computer system 500 of FIG. 5 ) can be programmed to perform the special purpose functions of one or more of the devices and subsystems of the system 100 . On the other hand, two or more programmed computer systems or devices can be substituted for any one of the devices and subsystems of the system 100 . Accordingly, principles and advantages of distributed processing, such as redundancy, replication, etc., also can be implemented, as desired, to increase the robustness and performance of the system 100 , for example.
FIG. 2 is a flowchart depicting processes performed by an exemplary cheater detection program 115 running on the game servers 103 of FIG. 1 . As the online game clients or players 105 connect to the game server 103 , the cheat detection/logging program 115 scans for the clients 105 using known or suspected cheats. Upon detection of a cheating client or player 105 , the relevant information about the cheater is logged to the cheater log file 119 by the cheat detection/logging software 115 . Accordingly, in FIG. 2 , at step 201 , the cheater detection/logging program 115 gets detected cheater information and logs the cheater information to the log file 119 , at step 203 . Execution then returns to step 201 , completing the cheater information logging processing.
FIG. 3 is a flowchart depicting processes performed by an exemplary cheater prevention client program 113 running on the game servers 103 of FIG. 1 . Generally, the cheater log file 119 is read and parsed by the cheater prevention client program 113 . Then, when the cheater prevention client program 113 is appropriately commanded or called, the cheater prevention client program 113 attempts to connect to the master server 101 to transmit the cheater information 121 .
Accordingly, in FIG. 3 , at step 301 , the cheater prevention client program 113 is called and then connects to the master server 101 , at step 303 . Once a stable connection is established between the master server 101 and the game server 103 , at step 305 , the cheater prevention client program 113 waits for the cheater prevention server program 111 to perform an authentication process. The authentication process can be performed, for example, by the cheater prevention server program 111 comparing the IP address associated with the game server 103 running the cheater prevention client program 113 with a list of authorized game servers 103 and/or by checking a security password. This feature, however, is optional and no authentication can be performed, if desired.
If the authentication fails, the connection is closed, at step 307 . Otherwise, upon positive authentication or upon disabling of the authentication feature, the cheater prevention client program 113 waits for the cheater prevention server program 111 to verify software versions to ensure compatibility, at step 305 . If the version comparison fails, the connection can be terminated, at step 307 .
Otherwise, at step 309 , the cheater prevention client program 113 reads and parses the cheater log file 119 generated by the anti-cheat software 115 and transmits the cheater information 121 extracted from the log file 119 to the master server 101 . Then, at step 311 , the master server 101 then appends and stores the new cheater entries from the cheater information 121 into the master file 117 on the master database 107 . The cheater prevention client program 113 then receives the master file 117 of the cheaters identified by the various game servers 103 from the master server 101 .
The cheater prevention client program 113 , at step 311 , also stores the cheater information from the master file 117 into one or more files that can be read by online gaming software running on the game server 103 . Advantageously, the cheating players listed in the master file 117 are automatically banned by the online gaming software on the game server 103 . Then, at step 307 , the cheater prevention client program 113 closes the connection with the master server 101 and terminates execution, and returns to step 301 to wait for the next program call, completing the cheater prevention client process.
FIG. 4 is a flowchart depicting processes performed by an exemplary cheater prevention server program 111 running on the master server 101 . As noted above, the Server Module includes, for example, the master database 107 , including the master list 117 of cheaters, and the cheater prevention server program or software 111 . Accordingly, in FIG. 4 , at step 401 , the cheater prevention server program 111 listens for or gets connection requests from the cheater prevention client programs 113 running on the game servers 103 .
When a connection is requested and after a connection is established, at step 403 , the cheater prevention server program 111 optionally performs the previously described authentication process, followed by the previously described version checking process, at step 405 , and closes the connection, at step 407 , if necessary. Otherwise, at step 409 , the cheater prevention server program 111 receives the cheater information 121 , parsed from the log file 119 by the cheater prevention client program 113 , from the cheater prevention client program 113 . Then, at step 411 , the cheater prevention server program 111 transmits the updated master file 117 to the cheater prevention client program 113 . The connection is then closed, at step 407 , and control returns to step 401 for further cheater information 121 processing, completing the cheater prevention server process.
An exemplary implementation of the present invention will now be described. The cheater prevention program (e.g., written in Perl, C++, etc.), including the Server and Client modules, allows the online game (e.g., Half-Life, Counter-strike, etc.) servers 103 to transmit the cheater information 121 regarding cheaters during online games to the master database 107 and automatically receive master files 117 of cheaters (e.g., banned cheaters) from participating game servers 103 from the master database 107 . The cheater prevention client program 113 automatically parses the anti-cheat program 115 (e.g., CSGuard, HLGuard, etc.) log files 119 of detected online game cheaters that are in a standard log format and transmits the cheater information 121 to the master server 101 , where the data is stored in the master file 117 on the master database 107 by the server module. Game server plugins 115 (e.g., CSGuard, HLGuard, etc.) perform the cheater detection on the individual game servers 103 .
The cheater prevention program 113 can be implemented, for example, as a standalone executable program. The cheater prevention client program 113 can work in conjunction with an automatic execution scheduling program (e.g., Cron, etc.) for scheduled execution operation. The client program 113 runs on an Operating System (OS) capable of running a dedicated game server 103 , such as a Half-Life Dedicated Server (HLDS), etc., and remote system access can be employed. In a preferred embodiment, the client program 113 is not configured as a server module or a plugin (e.g., an adminmod plugin, etc.) so that the client program 113 is not run via file transfer protocol (FTP), etc. However, the client program 113 can be configured as a server module or a plugin (e.g., an adminmod plugin, etc.) so that the client program 113 can run via FTP, etc., as will be appreciated by those skilled in the relevant art(s)
As noted above, the cheater prevention client program 113 works on systems that support online games (e.g., Half-Life with any of the various configurations, etc.). In the Windows environment, the master file 117 and the cheater log file 119 (e.g., a *.cfg file, etc.) paths employ forward slashes (“/”) rather than the standard Windows backslash (“\”). Accordingly, the path “c:\Windows\Desktop” would be written as “c:/Windows/Desktop”.
Although an infinite number of possible log formats can be employed, the cheater prevention client program 113 employs a standard log format. Accordingly, an end user of the online game server 103 can add a line to the configuration file of the anti-cheat detection program 115 (e.g., CSGuard, HLGuard, etc.) to appropriately format output for the cheater prevention client program 113 . For example, the standard log format can be given by:
mm/dd/yyyy:cheatername:wonid:ip:cheattype
where mm/dd/yyyy is a timestamp in month, day, and year format, cheatername is an online handle or name used by a detected cheater, wonid is an online gaming identification (e.g., a WON identification) of the detected cheater, ip is an Internet Protocol (IP) address of the online gaming client 105 of the detected cheater, and cheattype is the type of online game cheat detected.
The data that is relevant to cheater prevention program 113 , for example, is included in a single string separated by colons. Advantageously, this simple yet effective format all but eliminates the chance for errors in parsing and conserves memory space and bandwidth. For most anti-cheat detection programs 115 , one line can be added to the configuration file. For example, in the case of the HLGuard anti-cheat detection program 115 , the following line is added to the configuration file (e.g., csgconfig.cfg):
csg_action “b:found” “csg_writefile cstrike/cheaterlist.txt; csg_write \‘% d:% n:% w:% i:% y\’”
where cheaterlist.txt is the cheater log file 119 that the detected cheater information is stored in, % d:% n:% w:% i:% y is the standard format described above, and the remaining terms are commands specific to the HLGuard anti-cheat detection program 115 .
In the above example, the added command line is written as one line (e.g., not including any hard returns). In a similar manner, other types of anti-cheat detection programs 115 can be configured to support the Standard format. If the game server 103 is rented from a hosting company (e.g., Martnet, TheNetGamer, etc.), the hosting company can technically support the cheater prevention program 113 by providing any necessary system and program access and permit use of the program 113 .
In a preferred embodiment, only cheaters who are actually banned from a game server 103 are added to the master file 117 . Otherwise, minor offenders and questionable cheaters (e.g., cheaters detected by methods that are potentially faulty, such as aimbot detection, etc.) can get added to the master file 117 , leading to undesirable results.
The cheater prevention client program 113 can be installed by storing the executable program file scripts on the game server 103 where the anti-cheat program 115 cheater log files 119 are stored. This usually entails some sort of shell access to the game server 103 . As noted above, the configuration file (e.g., csgconfig.cfg) for the anti-cheat program 115 can be modified to support the Standard log format. In addition, in the case of the cheater prevention client program 113 being implemented via a Perl script, Perl script support can be installed on the game server 103 .
Accordingly, the above process includes extracting executable and other program files (e.g., filename.tar.gz) to a directory where the client program 113 is to reside. For example, this creates an installation instruction file (e.g., Readme.txt), an executable file, (e.g., client.pl) and a configuration file (e.g., config.cfg) for the cheater prevention client program 113 .
Advantageously, variables in the cheater prevention client program 113 configuration file can be edited for user customization. For example, the configuration file can include the following variables:
allowupload=1;
allowdownload=1;
where these variables control what action the client program 113 performs when the client program 113 connects to the master server 101 . For example, the allowupload variable determines whether or not the client program 113 is to parse the cheater log file 119 and upload the cheater information 121 to the master server 101 . The allowdownload variable determines whether or not the client program 113 is to download the latest version of the master file 117 from the master server 101 . In both cases, for example, a setting of “1” enables the specified function.
The configuration file also can include the following variable:
port=0;
where this variable control which port on the game server 103 is used by the client program 113 . For example, users behind a firewall can specify a port for the client program 113 to use via the port variable. If the port variable is set to zero, a random port can be employed.
The configuration file also can include the following variables:
bannedfilepath=/path/to/csbl_banned.cfg;
cheaterlistpath=/path/to/cheaterlist.txt;
where these variables control which files the client program 113 uses for its operations. For example, the bannedfilepath variable is the full path to the file that the client program 113 writes to when it downloads a new master file 117 (e.g., csbl_banned.cfg) from the master server 101 . By default, this file is given a different name than the cheater log file 119 (e.g., banned.cfg), so that it will not overwrite the original cheater log file 119 of the anti-cheat detection program 115 . If another name is used, exec yourbannedfilename.cfg can be added to the config.cfg file of the game server 103 . The csbl_banned.cfg file gets overwritten every time a new master file 117 is downloaded from the master server 101 . The cheaterlistpath variable is the full path to the file cheaterlist.txt that contains the anti-cheat detection program 115 output cheater log file 119 in the Standard log format.
The configuration file also can include the following variable:
verbose=0;
where this variable controls verbose logging. When turned on by being set to a value of 1, details of data transfers are logged for debugging purposes.
The configuration file also can include the following variable:
password=nopass;
where this variable controls the client program 113 authentication on the master server 101 . When turned off by being set to a value of nopass, no authentication is performed by the master server 101 . Otherwise, the password variable can be set with a valid security password used by the master server 101 for authentication purposes. In this way, the client program 113 hosts with invalid security passwords will not be allowed to connect to the master server 101 .
The configuration file also can include the following variable:
max_filesize=1500;
where this variable is employed for game servers 103 having an excessive number of banned player entries (e.g., banid) in a single *.cfg file, which can cause lag, slow game map changes and even crash the game server 103 . In one embodiment, the client program 113 automatically distributes the cheater entries to several different files. In this case, these files take the format of the csbl_banned.cfg file name followed by a number (e.g., csbl_bannedl.cfg). The csbl_banned.cfg file executes each of such files in sequence. Accordingly, adding exec csbl_banned.cfg to the game server 103 server.cfg file is sufficient. The max_filesize variable controls the maximum number of cheater entries that can be placed in each of such files. Advantageously, if the game server 103 is experiencing lag or crash problems, the value assigned to this variable can be adjusted, as necessary.
As noted above, the configuration file (e.g., csgconfig.cfg for CSGuard, etc.) for the anti-cheat detection program 115 can be edited to create detected cheater log files 119 in the Standard format. Otherwise, the parser in the client program 113 may not work with other formats, including any default anti-cheat program 115 formats. However, the client program 113 can be configured to support formats used by the anti-cheat program 115 , as will be appreciated by those skilled in the relevant art(s).
In addition, since the client program 113 downloads the latest master file 117 to a specified file, a single line can be added to the configuration file (e.g., server.cfg, autoexec.cfg, etc.) of the game server 103 . For example, if the master file 117 is called csbl_banned.cfg (e.g., the default name), the following line can be added:
exec csbl_banned.cfg
Otherwise, if the master file 117 is called something other than csbl_banned.cfg, the corresponding filename can be substituted for csbl_banned.cfg.
As noted above, for scheduled execution, a program (e.g., Cron) can be used to schedule the client program 113 (e.g., client.pl) to run automatically. For example, a Cron job to run the client program 113 can be scheduled. Although it does not really matter how often the client program 113 is run, running the client program 113 once daily is adequate for most game servers 103 . Advantageously, such a schedule will ensure that the master file 117 is updated daily and that new cheaters are logged every time the client program 113 runs.
For example, for scheduling the running of the client program 113 once daily, a crontab of the Cron program can be given by:
# Run client program once daily
@daily /path/to/client-os
where the real path to the client program 113 executable is used in place of path, and the actual name and version for the client program 113 is used in place of client.
Otherwise, manual operation or other programs can be employed to schedule the execution of the client program 113 . However, the client program 113 can be modified to perform automatically scheduled execution, as will be appreciated by those skilled in the relevant art(s).
Accordingly, the above and other features of the present invention include, for example, enabling or disabling of client program 113 authentication at the master server 101 ; optimized network communications; automatic generation of multiple sequential csbl_banned.cfg files to address potential game server lag and efficient program operation; printing of various client program 113 output to console, as an indication that the client program 113 is working properly; providing routines for terminating a connection to the master server 101 to reduce hangs; including a SO_KEEPALIVE variable so dead clients 113 get pushed out of the connection queue faster; providing a verbose logging configuration option; providing an executable for other systems (e.g., libc5 Linux systems, etc.); logging and printing of an error if a new version of the client program 113 exists; database queries that do no take place during the client/server interaction to speed program operation; user selection of a port for use by the client program 113 ; and use of a timeout value for the client program 113 , so connections to the master server 101 do not hang.
The system 100 can store information relating to various processes described herein. This information can be stored in one or more memories, such as a hard disk, optical disk, magneto-optical disk, RAM, etc., of the devices of system 100 One or more databases of the devices and subsystems of the system 100 of FIG. 1 can store the information used to implement the embodiments of the present invention. The databases can be organized using data structures (e.g., records, tables, arrays, fields, graphs, trees, and/or lists) included in one or more memories, such as the memories listed above or any of the storage devices listed below in the discussion of FIG. 5 , for example.
The previously described processes can include appropriate data structures for storing data collected and/or generated by the processes of the system 100 of FIG. 1 in one or more databases thereof. Such data structures accordingly can include fields for storing such collected and/or generated data. In a database management system, data can be stored in one or more data containers, each container including records, and the data within each record can be organized into one or more fields. In relational database systems, the data containers can be referred to as tables, the records can be referred to as rows, and the fields can be referred to as columns. In object-oriented databases, the data containers can be referred to as object classes, the records can be referred to as objects, and the fields can be referred to as attributes. Other database architectures can be employed and use other terminology. Systems that implement the embodiments of the present invention are not limited to any particular type of data container or database architecture.
All or a portion of the system 100 (e.g., as described with respect to FIGS. 1–4 ) can be conveniently implemented using one or more conventional general purpose computer systems, microprocessors, digital signal processors, micro-controllers, etc., programmed according to the teachings of the embodiments of the present invention (e.g., using the computer system of FIG. 5 ), as will be appreciated by those skilled in the computer and software art(s). Appropriate software can be readily prepared by programmers of ordinary skill based on the teachings of the present disclosure, as will be appreciated by those skilled in the software art. Further, the system 100 can be implemented on the World Wide Web (e.g., using the computer system of FIG. 5 ). In addition, the system 100 (e.g., as described with respect to FIGS. 1–4 ) can be implemented by the preparation of application-specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be appreciated by those skilled in the electrical art(s).
FIG. 5 illustrates a computer system 500 upon which the embodiments of the present invention (e.g., the devices and subsystems of the system 100 of FIG. 1 ) can be implemented. The embodiments of the present invention can be implemented on a single such computer system, or a collection of multiple such computer systems. The computer system 500 can include a bus 501 or other communication mechanism for communicating information, and a processor 503 coupled to the bus 501 for processing the information. The computer system 500 also can include a main memory 505 , such as a random access memory (RAM), other dynamic storage device (e.g., dynamic RAM (DRAM), static RAM (SRAM), synchronous DRAM (SDRAM)), etc., coupled to the bus 501 for storing information and instructions to be executed by the processor 503 .
In addition, the main memory 505 also can be used for storing temporary variables or other intermediate information during the execution of instructions by the processor 503 . The computer system 500 further can include a ROM 507 or other static storage device (e.g., programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.) coupled to the bus 501 for storing static information and instructions.
The computer system 500 also can include a disk controller 509 coupled to the bus 501 to control one or more storage devices for storing information and instructions, such as a magnetic hard disk 511 , and a removable media drive 513 (e.g., floppy disk drive, read-only compact disc drive, read/write compact disc drive, compact disc jukebox, tape drive, and removable magneto-optical drive). The storage devices can be added to the computer system 500 using an appropriate device interface (e.g., small computer system interface (SCSI), integrated device electronics (IDE), enhanced-IDE (E-IDE), direct memory access (DMA), or ultra-DMA).
The computer system 500 also can include special purpose logic devices 515 , such as application specific integrated circuits (ASICs), full custom chips, configurable logic devices (e.g., simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs), etc.), etc., for performing special processing functions, such as signal processing, image processing, speech processing, voice recognition, communications functions, etc.
The computer system 500 also can include a display controller 517 coupled to the bus 501 to control a display 519 , such as a cathode ray tube (CRT), liquid crystal display (LCD), active matrix display, plasma display, touch display, etc., for displaying or conveying information to a computer user. The computer system can include input devices, such as a keyboard 521 including alphanumeric and other keys and a pointing device 523 , for interacting with a computer user and providing information to the processor 503 . The pointing device 523 can include, for example, a mouse, a trackball, a pointing stick, etc., or voice recognition processor, etc., for communicating direction information and command selections to the processor 503 and for controlling cursor movement on the display 519 . In addition, a printer can provide printed listings of the data structures/information of the system shown in FIG. 1 , or any other data stored and/or generated by the computer system 500 .
The computer system 500 can perform a portion or all of the processing steps of the invention in response to the processor 503 executing one or more sequences of one or more instructions contained in a memory, such as the main memory 505 . Such instructions can be read into the main memory 505 from another computer readable medium, such as the hard disk 511 or the removable media drive 513 . Execution of the arrangement of instructions contained in the main memory 505 causes the processor 503 to perform the process steps described herein. One or more processors in a multi-processing arrangement also can be employed to execute the sequences of instructions contained in the main memory 505 . In alternative embodiments, hard-wired circuitry can be used in place of or in combination with software instructions. Thus, embodiments are not limited to any specific combination of hardware circuitry and/or software.
Stored on any one or on a combination of computer readable media, the embodiments of the present invention can include software for controlling the computer system 500 , for driving a device or devices for implementing the invention, and for enabling the computer system 500 to interact with a human user (e.g., users of the system 100 of FIG. 1 , etc.). Such software can include, but is not limited to, device drivers, firmware, operating systems, development tools, applications software, etc. Such computer readable media further can include the computer program product of an embodiment of the present invention for performing all or a portion (if processing is distributed) of the processing performed in implementing the invention. Computer code devices of the embodiments of the present invention can include any interpretable or executable code mechanism, including but not limited to scripts, interpretable programs, dynamic link libraries (DLLs), Java classes and applets, complete executable programs, Common Object Request Broker Architecture (CORBA) objects, etc. Moreover, parts of the processing of the embodiments of the present invention can be distributed for better performance, reliability, and/or cost.
The computer system 500 also can include a communication interface 525 coupled to the bus 501 . The communication interface 525 can provide a two-way data communication coupling to a network link 527 that is connected to, for example, a local area network (LAN) 529 , or to another communications network 533 (e.g. a wide area network (WAN), a global packet data communication network, such as the Internet, etc.). For example, the communication interface 525 can include a digital subscriber line (DSL) card or modem, an integrated services digital network (ISDN) card, a cable modem, a telephone modem, etc., to provide a data communication connection to a corresponding type of telephone line. As another example, the communication interface 525 can include a local area network (LAN) card (e.g., for Ethernet™, an Asynchronous Transfer Model (ATM) network, etc.), etc., to provide a data communication connection to a compatible LAN. Wireless links can also be implemented. In any such implementation, the communication interface 525 can send and receive electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. Further, the communication interface 525 can include peripheral interface devices, such as a Universal Serial Bus (USB) interface, a PCMCIA (Personal Computer Memory Card International Association) interface, etc.
The network link 527 typically can provide data communication through one or more networks to other data devices. For example, the network link 527 can provide a connection through the LAN 529 to a host computer 531 , which has connectivity to the network 533 or to data equipment operated by a service provider. The LAN 529 and the network 533 both can employ electrical, electromagnetic, or optical signals to convey information and instructions. The signals through the various networks and the signals on the network link 527 and through the communication interface 525 , which communicate digital data with computer system 500 , are exemplary forms of carrier waves bearing the information and instructions.
The computer system 500 can send messages and receive data, including program code, through the network 529 and/or 533 , the network link 527 , and the communication interface 525 . In the Internet example, a server can transmit requested code belonging to an application program for implementing an embodiment of the present invention through the network 533 , the LAN 529 and the communication interface 525 . The processor 503 can execute the transmitted code while being received and/or store the code in the storage devices 511 or 513 , or other non-volatile storage for later execution. In this manner, computer system 500 can obtain application code in the form of a carrier wave. With the system of FIG. 5 , the embodiments of the present invention can be implemented on the Internet as a Web Server 500 performing one or more of the processes according to the embodiments of the present invention for one or more computers coupled to the web server 500 through the network 533 coupled to the network link 527 .
The term “computer readable medium ” as used herein can refer to any medium that participates in providing instructions to the processor 503 for execution. Such a medium can take many forms, including but not limited to, non-volatile media, volatile media, transmission media, etc. Non-volatile media can include, for example, optical or magnetic disks, magneto-optical disks, etc., such as the hard disk 511 or the removable media drive 513 . Volatile media can include dynamic memory, etc., such as the main memory 505 . Transmission media can include coaxial cables, copper wire and fiber optics, including the wires that make up the bus 501 . Transmission media can also take the form of acoustic, optical, or electromagnetic waves, such as those generated during radio frequency (RF) and infrared ( 1 R) data communications.
As stated above, the computer system 500 can include at least one computer readable medium or memory for holding instructions programmed according to the teachings of the invention and for containing data structures, tables, records, or other data described herein. Common forms of computer-readable media can include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, CDRW, DVD, any other optical medium, punch cards, paper tape, optical mark sheets, any other physical medium with patterns of holes or other optically recognizable indicia, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can read.
Various forms of computer-readable media can be involved in providing instructions to a processor for execution. For example, the instructions for carrying out at least part of the embodiments of the present invention can initially be borne on a magnetic disk of a remote computer connected to either of the networks 529 and 533 . In such a scenario, the remote computer can load the instructions into main memory and send the instructions, for example, over a telephone line using a modem. A modem of a local computer system can receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal and transmit the infrared signal to a portable computing device, such as a personal digital assistant (PDA), a laptop, an Internet appliance, etc. An infrared detector on the portable computing device can receive the information and instructions borne by the infrared signal and place the data on a bus. The bus can convey the data to main memory, from which a processor retrieves and executes the instructions. The instructions received by main memory can optionally be stored on storage device either before or after execution by processor.
Although the present invention is described in terms of applications in online gaming over a communications network 123 and/or 125 , such as the Internet, the present invention can be applied to online gaming over other communications networks, such as intranets, extranets, Local Area Networks (LANs), etc., as will be appreciated by those skilled in the relevant art(s). For example, the communications network 125 can be an intranet for hosting a LAN online gaming session. In this case, cheaters identified by the anti-cheat software 115 can be transmitted to the master server 101 via the cheater prevention client program 113 over the communications network 123 , including the Internet.
Although the present invention is described in terms of cheating prevention client and server programs separate from cheat detection and/or gaming server programs, the cheating prevention client and/or server programs can be implemented as modules included within the cheat detection and/or gaming server programs, as will be appreciated by those skilled in the relevant art(s).
While the present invention have been described in connection with a number of embodiments and implementations, the present invention is not so limited but rather covers various modifications and equivalent arrangements, which fall within the purview of the appended claims.
|
A method, system, and software for preventing cheating during online gaming on a first computer system, include receiving information regarding cheaters detected during online gaming gathered by a second computer system; and making the received information available to the first computer system. Advantageously, a cheater identified on the second computer system is prevented from online gaming on the first computer system. A method, system, and software for preventing cheating during online gaming also is described, including receiving information regarding cheaters detected during online gaming from a first computer system; and transmitting information regarding cheaters detected during online gaming gathered from a plurality of online gaming computer systems to the first computer system. Advantageously, cheaters identified on the plurality of online gaming computer systems are prevented from online gaming on the first computer system.
| 0
|
FIELD OF THE INVENTION
This invention is directed to the marine industry and in particular to multi-blade propellers.
BACKGROUND OF THE INVENTION
The propulsion system on a boat is one of the most important aspects of boat design, yet least understood. There are variety of items that make up the propulsion system and numerous items that affect how well the propulsion system works.
The propeller remains the most critical aspect of the propulsion system. Shaft angle, boat trim, stern gear, boat weight, engine horsepower and gear ratio are but a few items that affect propeller performance and behavior.
A major concern of propeller design is the amount of vibration that the propeller will produce while under way. As a general rule, in order to minimize vibration the number of blades on the propeller should be increased. There is no particular limit to the number of blades a propeller may have however, costs increase with the number of blades while the gain in reduction of vibration decreases with each additional blade. A negative consequence of increasing the number of blades on the propeller is the progressive reduction of efficiency of the propeller while operating in reverse to back down the boat.
Another major concern in propeller design is cavitation. One of the most unpredictable conditions that affects propeller operation is cavitation. Cavitation is a partial vacuum caused by excessive propeller speed or loading. The vacuum causes bubbles to form and implode irregularly causing uneven pressure on both sides of the blades resulting in vibration that feels like an unbalanced or unequally pitched blades. Further, the force of imploding bubbles can actually pull materials off the surface of the propeller leading to pitting, uneven wear, and resulting in bad balance and additional vibration.
On higher speed vessels, those operating over 40 knots, shaft rpms frequently force the propellers into a condition that some cavitation is difficult to avoid. For this reason super cavitating propellers have been developed that are capable of operating at high speeds without cavitation. These high speed propellers have blades shaped so that the low pressure side of the blade where cavitation forms, is vented to the atmosphere making cavitation almost impossible. The super cavitating propellers, commonly referred to as surface piercing propellers, were typically found only on high speed boats.
The surface piercing propellers are designed to work when partially submerged, e.g. about half in and half out of the water. Typically, such propellers are mounted aft of the transom except in cases like Small U.S. Pat. No. 4,689,026 where the propeller operates in a tunnel.
A disadvantage to these types of propellers is their inability to provide sufficient reversing thrust. The blade shape required for high efficiency at speed in a super cavitating design inhibits reversing properties that are normal to the typical propeller. This is caused by two factors. First, the blade has a progressive pitch which means that the pitch gets progressively higher as it approaches the trailing edge of the blade. When used in reverse, the trailing edge has too much pitch for efficient operation. Second, the trailing edge of a super cavitating propeller is sharp because, in forward, it is desired to have the flow of water separate from the blade efficiently. While required in forward, this sharp trailing edge becomes the leading edge in reverse and, as such, degrades reverse thrust by causing a ventilation bubble. If the blades are close together, the bubble from one blade can extend to the adjacent blade causing a total loss in reverse thrust. Yet a high number of blades is desired to minimize vibration so an inherent design conflict exists.
Thus what is lacking in the art is a multi-blade propeller having a shape that does not affect forward performance yet allows reversing properties similar to those of a conventional propeller.
SUMMARY OF THE INVENTION
The instant invention is directed toward a marine propeller with increased performance in reverse but without decreased performance in forward, having a hub and a multiplicity of blades extending radially outward from the hub. The separation of these blades about the hub lessens interference between the blades and increases the efficiency of the propeller. Interference between adjacent blades may be reduced by decreasing the number of blades or increasing the length of certain blades beyond the length of other blades or increasing the diameter of certain blades beyond the diameter of other blades.
Accordingly, it is an object of this invention to provide a multi-blade propeller with improved performance for backing down a boat.
It is a further object of this invention to decrease the interference of each propeller blade with the performance of the blades directly adjacent to it while operating in reverse.
Another object of this invention is to provide multi-blade propellers with a portion of the trailing edge of some of the blades further aft than the trailing edges of the other blades.
It is a further object of this invention to provide a propeller with blades having different widths.
It is a further object of this invention to provide a propeller with a modified trailing edge.
It is a further object of this invention to provide the trailing edge of the blades with a shallow concavity.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial elevation of a propeller having blades of differing widths;
FIG. 2 shows a partial elevation of a propeller having blades with different diameter on the same hub;
FIG. 3 shows a partial elevation of a propeller having blades with a modified trailing edge; and
FIG. 4 shows a cross section of a modified blade along line 4 — 4 of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 a boat propeller 10 is shown with only two blades for simplicity. Also, the blades are shown without pitch so they appear flat. These propellers may be made with any number of blades on a hub. The blades of these multi-blade propellers are disposed symmetrically about the hub, for example, the blades of a four bladed propeller are ninety degrees apart and a ten blade propeller has blades 36 degrees apart. The forward end of hub 11 has a keyway 12 into which a drive shaft (not shown) is fitted. The drive shaft transmits the power from the engine(s) to the propeller. The blade 13 has a leading edge 14 and trailing edge 15 . The trailing edge 15 intersects the leading edge 14 defining the blade surface. The length of the blade is determined as the distance from hub to the point where the leading edge and trailing edge intersect. The width of the blade is determined as the distance from the leading edge to the trailing edge at a fixed radius from the hub. The chord of the blade is, in general, the thickness of the blade at its thickest point.
During rotation, the blades of the propeller have a high pressure side and a low pressure side. The high pressure side of the blade is the forward or leading side in the direction of the rotation of the propeller. The low pressure side of the blade is the following or back side. The blades of the propeller are designed to operate most efficiently in forward gear with the high pressure side leading in the direction of rotation. These considerations, in general, dictate the form of the back side of the blades. However, in reverse, the low pressure side becomes the leading side.
In FIG. 1 and all the other Figures, the surface R of the blades is the low pressure side and initially contacts the water in reverse. This denotes a rotation of the blades, in reverse, toward the viewer of the Figures.
The blade 16 has a leading edge (not shown) which is shaped identically with leading edge 14 and extends from the hub in the same plane as the leading edge 14 . Blade 16 has a trailing edge 17 . Blades 13 and 16 have the same profile in length and chord. Blade 13 has a width w which is less than the width w′ of blade 16 .
While FIG. 1 shows the blades 13 and 16 as being adjacent, in practice, not every adjacent blade must have a different width. For example, a propeller with eight blades may have four alternating blades with one width and the other four blades with a greater width while a propeller with nine blades may only have three blades with a greater width than the others. The only prerequisite is that the propeller must remain balanced.
When the propeller of FIG. 1 is turned in reverse, the trailing edge 17 and any other blade with a greater width w′ cuts into undisturbed water because the blade which preceded it is now behind it in the axial direction. The ventilation bubble created by each wider blade is separated from the next wider blade by the number of intervening blades. Since the interference on the wider blades is reduced, the propeller becomes more efficient in reverse.
In FIG. 2 propeller 30 has hub 31 with a keyway 32 . Blade 33 has a leading edge 34 , a trailing edge 35 and a length L. Leading edge 38 of blade 36 extends from the hub 31 in the same plane as the leading edge 34 of blade 33 . Blade 36 has a trailing edge 37 , a leading edge 38 and a length L′. In FIG. 2, blade 36 has a greater length than blade 33 . Blade 36 and blade 33 can have the same profile in width and chord or they can have different width and chord as shown. As stated above, the blades shown in the FIG. 2 are adjacent but in practice there can be a number of blades interposed between the longer and/or wider blades.
In the embodiments shown in FIG. 3, the modification to the blades to increase reverse efficiency is on the trailing edge of the propeller blade. The trailing edge modification is kept inside an imaginary extension of the high pressure surface 49 and an imaginary extension of the low pressure side of the blade 50 (shown in FIG. 4 ). In this manner, the modifications do not affect the propeller operation in forward motion.
FIG. 3 shows a marine propeller with a hub 41 , a keyway 42 , and blades 43 . The blades 43 have the same profile in width, length and chord. The leading edges 44 of the blades extend from the hub in the same plane. The trailing edge of blades 43 have an addendum 51 , shown in FIG. 4, which extends further aft on what would normally be a flat surface in the case of a “cleaver” type super cavitating propeller. In reverse, the modified blades with the addendum 51 or radius 48 to smooth the flow of water in the reverse direction of rotation reduce the tendency to form a ventilation or cavitation bubble on the low pressure side of the blade because the water is flowing around a smooth radius 48 rather than a sharp edge, thereby increasing the bite of the modified blades. As stated above, the blade with the addendum or radius may be on every blade, on alternate blades or on any combination of blades as long as the entire propeller remains balanced.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.
|
A marine propeller with increased performance in reverse has a hub and a multiplicity of blades extending radially outward. A portion of the trailing edges of some or all of the blades are modified to lessen interference between blades and increase the bite of those blades when operated in reverse.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application is a divisional application of U.S. patent application Ser. No. 11/957,324 filed on Dec. 14, 2007, entitled “METHOD FOR MANUFACTURING MULTILAYER FLEXIBLE PRINTED CIRCUIT BOARD”, assigned to the same assignee, and disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a method for manufacturing a flexible printed circuit board, and particularly to a method for manufacturing a multilayer flexible printed circuit board having different thicknesses in different areas.
[0004] 2. Discussion of Related Art
[0005] Flexible printed circuit boards (FPCB) have been widely used in electronic products such as mobile phones, printing heads and hard disks. In these electronic products, some parts may move relative to a main body. In such a situation, FPCBs are applied to provide electrical connections and transmit signals between such parts and the main body due to their flexibility.
[0006] FIG. 34 shows a multilayer FPCB structure, which has different numbers of layers in different areas. In other words, there are thick areas and thin areas within the same FPCB. The thick area can have a higher circuit density, whilst the thin area exhibits higher flexibility.
[0007] FIGS. 29-34 show a process for manufacturing such a type of FPCB. As shown in FIGS. 29 and 30 , a first copper clad laminate (CCL) 41 , a binder layer 45 and a second CCL 42 are laminated. As is shown in FIG. 31 , dry films 412 , 422 are respectively applied on the first CCL 41 and the second CCL 42 , and then, the dry films 412 , 422 are exposed and developed. Because there is a cliff-like thickness difference between the first CCL 41 and the second CCL 42 , a gap 46 is formed in the included angle at the base of the ‘cliff’.
[0008] As shown in FIG. 32 , during an etching process, when the first CCL 41 and the second CCL 42 are immersed in an etching solution, the solution can seep into the gap 46 and react with the dielectric layers of the first CCL 41 and/or the second CCL 42 . As a result, the dielectric layers may become unstable and peel from the first CCL 41 and/or the second CCL 42 .
[0009] Referring to FIG. 33 , a third CCL 43 and a fourth CCL 44 are respectively laminated with the first CCL 41 and the second CCL 42 , to make another multilayer FPCB. Referring to FIG. 34 , in order to electrically connect the copper layers of the third CCL 43 , the first CCL 41 , the second CCL 42 , and the fourth CCL 44 , a via hole 47 is defined so as to penetrate all the four CCLs. The via hole 47 can be made by drilling or by laser ablation. After the via hole 47 is formed, a conductive layer, e.g., a copper layer, is formed on a sidewall of the via hole 47 by electroless plating or electroplating. In the plating process, the dielectric layer of the second CCL 42 is exposed in a plating solution, thereby forming a number of copper lumps 48 thereon. These copper lumps 48 can pierce dry film that is applied onto the second CCL 42 in the next pattern-forming process, and the etching solution used for developing the dry film can react with dielectric layer or copper layer of second CCL 42 and result in a poor quality product.
[0010] In the aforementioned process for manufacturing multilayer FPCB that has different number of layers in different areas, a step structure between different CCLs can causes a series of quality problems. Therefore, a new process for manufacturing multilayer FPCB is desired to overcome the aforementioned quality problems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Many aspects of the present method can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present method.
[0012] FIGS. 1 to 10 are schematic views, showing a process for manufacturing a multilayer FPCB having a different number of layers in different areas, in accordance with a first embodiment.
[0013] FIGS. 11 to 28 are schematic views, showing a process for manufacturing a multilayer FPCB having a different number of layers in different areas, in accordance with the second embodiment.
[0014] FIGS. 29 to 34 are schematic views, showing a process for manufacturing a multilayer FPCB having a different number of layers in different areas, in accordance with the third embodiment.
DETAILED DESCRIPTION
[0015] FIGS. 1-10 show the successive stages of a process for manufacturing an FPCB that has a different number of layers in different areas, in accordance with a first embodiment.
[0016] Referring to FIG. 1 , a first substrate 11 includes a dielectric layer 111 and a conductive layer 112 formed on the dielectric layer 111 . The second substrate 12 includes a dielectric layer 121 and a conductive layer 122 formed on the dielectric layer 121 . A binder layer 13 is sandwiched between the first substrate 11 and the second substrate 12 . A locating hole 104 is defined so as to penetrate through the first substrate 11 , the binder layer 13 and the second substrate 12 .
[0017] Referring to FIG. 2 , the first substrate 11 includes a main portion 113 surrounded by an imaginary boundary line 116 (i.e. a functional portion prepared for making a circuit thereon according to need) and an excess portion 114 surrounded by an imaginary boundary line 117 (i.e. a sacrificing portion which will be removed in a later step). An imaginary boundary line 115 is defined between the main portion 113 and the excess portion 114 . The main portion 113 is encompassed by an imaginary boundary line 116 and the imaginary boundary line 115 . The excess portion 114 is encompassed by another imaginary boundary line 117 and the imaginary boundary line 115 .
[0018] Materials of the dielectric layers 111 , 121 and the binder layer 13 can be selected from the group consisting of polyimide, polytetrafluoroethylene, polythiamine, polymethacrylic acid, polycarbonate, polycarbonate ester, polyester, copolymer of imide, ethylene and dimethyl terephthalate. The conductive layers 112 , 122 can be a film made of copper, silver or aluminum.
[0019] Referring to FIGS. 3 and 4 , the binder layer 13 includes two opposite surfaces 131 , 132 . An opening 133 is formed in the binder layer 13 thereby an inner side wall surface 134 of the binder layer 13 is defined. The opening 133 can be formed by cutting, stamping, laser ablation or etching. In this embodiment, the opening 133 has a rectangular shape, but the opening 133 can also be of other shapes, for example, trapezium, triangle etc.
[0020] Referring to FIG. 5 , a first slit 110 is formed in the dielectric layer 111 of the first substrate 11 along the boundary line 115 . The first slit 110 can be formed by laser ablation or etching. E-beam etching or plasma etching can also be used to form the first slit 110 .
[0021] Referring to FIG. 6 , the first substrate 11 and the second substrate 12 are respectively laminated on the two opposite surfaces 131 , 132 of the binder layer 13 , thereby a semi-finished FPCB 14 is obtained. The excess portion 114 is exposed to and suspended above the opening 133 . The boundary line 115 is aligned with the inner side wall surface 134 of the binder layer 13 .
[0022] Referring to FIG. 7 , conductive patterns are formed in the conductive layers 112 , 122 . In this embodiment, the conductive patterns are formed using a DES (Developing, Etching and Stripping) process. Alternatively, the conductive patterns can also be formed using laser. A second slit 120 is formed in the conductive layer 112 along the boundary line 115 . The second slit 120 can be formed with the conductive patterns in the conductive layer 112 simultaneously, that is, the second slit 120 is a portion of the conductive patterns in the conductive layer 112 . Alternatively, the second silt 120 can also be formed after the making of the conductive patterns in the conductive layer 112 . For example, the second slit 120 can be formed using laser ablation after the conductive patterns is formed.
[0023] Referring to FIGS. 8 and 9 , the semi-finished FPCB 14 is cut along the boundary 116 and 117 . The excess portion 114 is not conglutinated with the binder layer 13 and is therefore very easy to remove. In this embodiment, the semi-finished FPCB 14 is cut using a stamper, and the excess portion 114 can be removed together with the stamper.
[0024] Referring to FIG. 10 , a FPCB 140 with a different number of layers in different areas is obtained.
[0025] FIGS. 11-17 show the successive stages of a process for manufacturing an FPCB that has a different number of layers in different areas, in accordance with a second embodiment.
[0026] Referring to FIG. 11 , a first substrate 21 includes a dielectric layer 211 , a conductive layer 212 and an outer conductive layer 213 . The conductive layer 212 and the outer conductive layer 213 are respectively formed on two opposite surfaces of the dielectric layer 211 . The conductive layer 212 has conductive patterns formed therein, i.e., the conductive layer 212 is made into a conductive pattern. The first substrate 21 includes a main portion 201 (i.e. a remaining portion which is designed in a particular fashion) and an excess portion 202 (i.e. a sacrificing portion which will be removed in a later step). A boundary 203 is sandwiched between the main portion 201 and the excess portion 202 . The main portion 201 has a boundary 204 . The excess portion has a boundary 205 .
[0027] The second substrate 22 includes two dielectric layers 221 and 223 , two conductive layers 222 and 224 , and a binder layer 225 . The conductive layer 222 is formed on the dielectric layer 221 . The conductive layer 224 is formed on the dielectric layer 223 . The binder layer 225 is in contact with the conductive layer 222 and the dielectric layer 223 .
[0028] Referring to FIG. 12 , the binder layer 23 includes two opposite surfaces 231 and 232 . An opening 233 is formed in the binder layer 23 in such a way that an inner sidewall surface 234 of the binder layer 23 is formed. The opening 233 can be formed by cutting, stamping, laser ablation or etching. In this preferred embodiment, the opening 233 has a rectangular shape, but the opening 233 can also be of other shapes, for example, trapezium, triangle etc.
[0029] Referring to FIG. 13 , a first slit 210 is formed in the dielectric layer 211 and the conductive layer 212 along the boundary 203 , that is, the first slit 210 is formed in all the layers in the first substrate 21 except the outer conductive layer 213 .
[0030] Referring to FIG. 14 , the first substrate 21 and the second substrate 22 are respectively laminated on two opposite surfaces 231 and 232 of the binder layer 23 . The conductive layer 212 is in contact with the surface 231 . The dielectric layer 221 is in contact with the surface 232 . The boundary 203 is aligned with the inner sidewall surface 234 . The excess portion 202 of the first substrate 21 is exposed to and suspended above the opening 233 .
[0031] Referring to FIG. 15 , conductive patterns are formed in the outer conductive layer 213 and the conductive layer 224 , thereby a semi-finished FPCB 24 is obtained. A second slit 220 is also formed in the outer conductive layer 213 along the boundary 203 . In this embodiment, the conductive patterns and the second slit are formed at a same time using a DES process.
[0032] Referring to FIGS. 16 and 17 , the semi-finished FPCB 24 is cut along the boundary 204 and 205 so as to remove the excess portion 202 , thereby a FPCB 240 with a different number of layers in different areas is obtained.
[0033] FIGS. 18-26 show the successive stages of a process for manufacturing an FPCB that has different number of layers in different areas, in accordance with a third preferred embodiment.
[0034] Referring to FIG. 18 , the first substrate 31 includes a dielectric layer 311 and a conductive layer 312 formed on the dielectric layer 311 . Referring to FIG. 19 , the first substrate 31 includes a main portion 301 and an excess portion 302 . The main portion 31 has a boundary 304 . The excess portion 302 has a boundary 305 . A boundary 303 is provided between the main portion 301 and the excess portion 302 . A first slit 310 is formed in the first substrate 31 along the boundary 303 .
[0035] Referring to FIGS. 20 and 21 , an inner binder layer 35 has two opposite surfaces 351 , 352 . An opening 353 is formed in the inner binder layer 35 , thereby an inner sidewall surface 354 is formed in the inner binder layer 35 .
[0036] Referring to FIG. 22 , a first substrate 31 and a second substrate 32 are respectively laminated on two opposite surfaces 351 , 352 . The second substrate 32 includes a dielectric layer 321 and a conductive layer 322 formed on the dielectric layer 321 . The dielectric layer 311 contacts the surface 351 . The dielectric layer 321 contacts the surface 352 . The boundary 303 is aligned with the inner sidewall surface 354 .
[0037] Referring to FIG. 23 , conductive patterns are formed in the conductive layer 312 and 322 thereby an inner laminated structure 330 is obtained. A second slit 320 is formed in the conductive layer 312 along the boundary 303 . In the present embodiment, the conductive patterns are formed using a DES process. The second slit 320 is formed at a same time with conductive patterns.
[0038] Referring to FIG. 24 , a first outer binder layer 36 includes a third slit 362 formed therein, in such a way that an inner sidewall surface 363 is formed in the first outer binder layer 36 . Referring to FIG. 25 , the first outer binder layer 36 is applied on the conductive layer 312 , an second outer binder layer 37 is applied on the conductive layer 322 . Another first substrate 31 is applied on the first outer binder layer 36 and another second substrate 32 is applied on the second outer binder layer 37 . Then, the first substrate 31 , the first outer binder layer 36 , the inner laminated structure 330 , the second outer binder layer 37 and the second substrate 32 are laminated using a laminating machine. The dielectric layer 311 is in contact with the first outer binder layer 36 . The dielectric layer 321 is in contact with the second outer binder layer 37 .
[0039] Referring to FIG. 26 , conductive patterns are formed in the conductive layer 312 and 322 thus a semi-finished FPCB 350 is obtained. A second slit 340 is formed in the conductive layer 312 . In this embodiment, the second slit 340 is formed together with the conductive patterns. The two first slits 310 , the two second slits 320 and the third slit 362 are configured to be aligned and in communication with the opening 353 .
[0040] Referring to FIG. 27 , the semi-finished FPCB 350 is cut along the boundary of the main portion 301 and the excess portion 302 of the first substrate 31 , so as to remove the excess portion 302 of the first substrate 31 . Referring to FIG. 28 , all the excess portion 302 of the first substrate 31 is removed, thereby a FPCB 360 with different number of layers in different areas is obtained.
[0041] In this embodiment, FPCBs are manufactured with the first substrate 31 and the second substrate 32 . The inner binder layer 35 separates the FPCB 360 into a first side and a second side. Two first substrates 31 and corresponding binder outer layer 36 constitute the first side. Two second substrate 32 and corresponding second outer binder layer 37 constitute the second side. Because the first substrate 31 has a first slit 310 preformed in the dielectric layer, thus when a second slit 320 aligned with the first slit 310 is formed in the conductive layer 312 of the first substrate 31 , the first substrate 31 is cut off at the first slit 310 . Furthermore, a third slit 362 aligned with first slit 310 is preformed in the first outer binder layer 36 . As a result, after the FPCB 360 is cut along the boundaries of the main portion 301 and the excess portion 302 of the first substrate 31 , the excess portion 302 exposed to the opening 353 of the inner binder layer 35 can be easily removed. Thus, a FPCB 360 with a different number of layers in different areas is obtained. In the present embodiment, the FPCB 360 is a four-layer structure. However, more first substrates 31 can be built up on the first side, until the predetermined number of layers is obtained.
[0042] In all of these preferred embodiments of manufacturing a FPCB has a different number of layers in different areas, there is no cliff-like structure created in the process, therefore all the aforementioned disadvantages are overcome.
[0043] Finally, it is to be understood that the above-described embodiments are intended to illustrate rather than to limit the invention. Variations may be made to the embodiments without departing from the spirit of the invention as claimed. The above-described embodiments illustrate the scope of the invention but do not restrict the scope of the invention.
|
A method for manufacturing a multilayer FPCB which includes providing a first substrate, a second substrate and a binder layer; defining an opening on the binder layer; defining a first slit in the dielectric layer of the first substrate; laminating the first substrate, the binder layer and the second substrate; forming a second slit in the conductive layer of the first substrate, the second slit being created so as to align with the first slit, cutting the first substrate, the binder layer and the second substrate thereby forming a multilayer flexible printed circuit board having different numbers of layers in different areas.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] This disclosure relates to the field of power amplifier circuits, and more specifically to the detection and correction of saturation in power amplification circuits.
[0003] 2. Discussion of Related Art
[0004] In some applications where power amplification of signals is required, precise control of the power gain may be desirable to achieve desired signal properties. For example, transmission modules used in communications devices such as cellular telephones, personal digital assistants (PDAs), etc. may require precise internal power control in certain modes of operation, such as Gaussian Minimum Shift Keying (GMSK) mode. In such applications, a power control circuit may be used that controls the gain of an amplifier stage. A typical control loop controls the amplifier gain via a loop error voltage based upon the difference between the output of a RF detector and a loop set point. The detector (which may be either a linear or a logarithmic detector) samples the amplified signal and produces a detector output indicative of the magnitude of the amplified signal (e.g., based upon the rf amplitude or the power of the amplified signal). The loop error voltage typically passes through an error amplifier (which may be proportional, integral, derivative, or a combination of any such elements, according to the requirements of the control loop design), yielding a gain control signal that controls the gain of the power amplifier.
[0005] Such power control feedback loops suffer severe degradation of performance as the amplifier approaches saturation. When the power amplifier saturates, increases in the gain control signal no longer result in increases in the power amplifier output. This leads to breakdown of the loop performance, such as, for example, the gain control voltage being pinned to the high rail as it increases in an attempt increase the output of the saturated power amplifier output. This condition is sometimes referred to as “loop saturation.”
[0006] In some applications, loop performance can be exceptionally sensitive to saturation, resulting in a power amplifier output other than what is desired. For example, in a typical circuit, control loop performance can degrade beyond acceptable limits at as little as 0.1 dB power amplifier saturation. One way to avoid loop saturation is to monitor the loop error signal and reduce the loop setpoint when saturation (or the imminent onset of saturation) is detected. Saturation can be difficult to detect, however, where the error induced by the saturation is small. In a typical loop circuit using a logarithmic detector to measure the amplifier output, for example, the detector sensitivity may be 50 mV per dB. An error of 0.1 dB in power then results in only 5 mV of error in the loop feedback signal. Since 5 mV is on the order of the error in standard CMOS amplifier input offsets, it may not be possible for the system to cleanly distinguish loop saturation from normal production variation in the performance of the amplifier itself.
[0007] Loop saturation may be easier to detect using a linear detector, where the detector sensitivity near saturation may be considerably higher; saturation can be observed directly by monitoring the loop error signal for deviation from zero when saturation occurs. However, as discussed further below, in a circuit using linear detection, applying a constant reduction to the loop setpoint results in an unacceptable distortion of the loop output. Further, in some applications it may be preferable for other reasons to use logarithmic detection. For example, compared to linear detection, logarithmic detection can provide a much wider dynamic range, which is desirable in many applications.
[0008] Thus, in many applications, it is preferable to use a logarithmic detector in the control loop, making saturation more difficult to detect.
SUMMARY OF THE INVENTION
[0009] Systems described herein include power amplification circuits that include circuitry to monitor signals at certain points in a control loop to determine when saturation exists (or is imminent), and process those signals to cause a step in an indicator voltage upon the commencement (or upon the imminent commencement) of saturation. This step can be observed by a controller that may respond to loop saturation in an appropriate manner. In particular, systems described herein include power amplification circuits that include logarithmic detection, and detect saturation (or the imminent onset of saturation) by monitoring a gain control voltage. According to another aspect, systems described herein include analog circuitry that responds to and corrects the detected saturation. In particular, the systems described include control circuits that correct detected saturation by applying an offset to a setpoint signal.
[0010] According to one aspect of the present invention, a power amplification circuit is presented, the circuit comprising a power amplifier having a power input to receive an input signal, a gain control input to receive a gain control signal, and a power output to provide an amplified output signal based upon the input signal and the gain control signal; a power detector to provide a power detector signal indicative of a magnitude of the amplified output signal of the power amplifier; an error amplifier having a first input to receive an amplification control signal, a second input to receive a signal based upon the detector signal, and an output electrically coupled to the gain control input of the power amplifier; and a saturation detector having a first input to receive a signal based upon the gain control signal, a second input to receive a reference signal, and an output to provide a saturation detection signal indicating whether gain control signal exceeds the reference signal. According to one embodiment, the output of the error amplifier is electrically coupled to the gain control input through a transistor. According to another embodiment, the transistor is powered by a battery voltage, and the reference signal is the battery voltage minus a voltage drop larger than a limit voltage of the transistor. According to still another embodiment, the power amplifier is not saturated when the gain control signal is less than the reference signal. According to still another embodiment, the power detector signal is proportional to the logarithm of an RF voltage at the output of the power amplifier. According to still another embodiment, the power detector signal is proportional to an RF voltage at the output of the power amplifier.
[0011] According to another embodiment a power amplification circuit further comprises a linear amplifier to receive the detector signal and to provide an amplified detector signal to the second error amplifier input. According to still another embodiment, the linear amplifier has unity gain. According to still another embodiment, the linear amplifier has non-unity gain.
[0012] According to still another embodiment, the saturation detector is a comparator.
[0013] According to another embodiment, a power amplification circuit further comprises an offset generator circuit to receive the saturation detection signal from the saturation detector and to provide, in response to the saturation detection signal indicating that the gain control signal exceeds the reference signal, an offset signal to the first input of the error amplifier. According to still another embodiment the offset generator circuit comprises a current source; a switch to activate the current source in response to the saturation detection signal indicating that the gain control signal exceeds the reference signal; and a linear amplifier having an input coupled to the current source and an output providing an offset signal, the output electrically coupled to the first input of the error amplifier. According to still another embodiment the output of the linear amplifier is electrically coupled to the first input of the error amplifier through a transistor. According to still another embodiment, the offset generator circuit generates a ramping offset signal in response to the saturation detection signal indicating that the gain control signal exceeds the reference signal.
[0014] According to another embodiment, a power amplification circuit further comprises an offset cutoff circuit to freeze the ramping offset signal in response to a signal based upon the offset signal exceeding an offset cutoff threshold signal. According to still another embodiment, the offset cutoff threshold signal is a signal based upon the power detector signal minus a predetermined voltage. According to still another embodiment, the offset cutoff circuit comprises: a cutoff comparator having a first input to receive a signal based upon the offset signal; a second input to receive the offset cutoff threshold signal; and an output indicating whether the signal at the first input exceeds the offset cutoff threshold signal, the output being electrically coupled to the offset generator circuit; wherein the offset generator circuit is deactivated in response to the comparator output indicating whether the signal at the first input exceeds the offset cutoff threshold signal.
[0015] According to another embodiment, a power amplification circuit further comprises a capacitor electrically coupled between the current source and ground.
[0016] According to another aspect of the present invention, a method of amplifying a first signal is presented, the method comprising acts of: receiving a gain setpoint signal; generating a gain control signal based upon the gain setpoint signal; amplifying the first signal based upon the gain control signal; detecting whether the gain control signal exceeds a predetermined threshold; and providing a saturation detection signal indicative of whether the gain control signal exceeds the predetermined threshold. According to one embodiment, the act of generating the control signal further comprises: receiving a power detector signal indicative of the amplified first signal; and generating a gain control signal based upon the power detector signal and the gain setpoint signal.
[0017] According to another embodiment, the method further comprises generating a correction signal in response to the saturation detection signal indicating that the gain control signal exceeds the predetermined threshold; and applying the correction signal to the gain setpoint signal. According to still another embodiment, the method further comprises detecting whether the correction signal exceeds a predetermined cutoff threshold; and generating a correction cutoff signal in response to the correction signal exceeding a cutoff threshold. According to still another embodiment, the method comprises ceasing an increase of the correction signal in response to the correction cutoff signal. According to still another embodiment, the method comprises maintaining the correction signal at a constant value in response to the correction cutoff signal.
[0018] According to another aspect of the present invention, a power amplification circuit is disclosed, the circuit comprising a power amplifier to receive an input signal and generate an amplified output signal; a power detector to provide a power detector signal indicative of the output signal of the power amplifier; a control circuit to receive a setpoint signal and producing a gain control signal that controls a gain of the power amplifier according to the setpoint signal; and means for providing a saturation detection signal indicating whether the gain control signal is within a saturation detection threshold of a reference signal. According to one embodiment, the power amplification circuit further comprises correction means for generating and applying a correction signal to the setpoint signal in response to the saturation detection signal indicating that the gain control signal is within a saturation detection threshold of a reference signal. According to another embodiment, a power amplification circuit further comprises monitor means for generating a correction cutoff signal if the correction signal exceeds a cutoff threshold. According to still another embodiment, a power amplification circuit further comprises cutoff means for ceasing an increase of the correction signal in response to the correction cutoff signal. According to still another embodiment, a power amplification circuit further comprises sustaining means for maintaining the correction signal in response to the correction cutoff signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
[0020] FIG. 1 is a block diagram of an exemplary transmission system having an amplification module;
[0021] FIG. 2 is a block diagram of an exemplary embodiment of a circuit for detecting and correcting saturation in a power control loop;
[0022] FIG. 3 is an exemplary embodiment of a power amplification circuit having loop saturation detection circuitry;
[0023] FIG. 4 is an exemplary embodiment of a power amplification circuit having circuitry for detecting and correcting saturation in the power amplification control loop; and
[0024] FIG. 5 is a graph showing the response curve of an exemplary logarithmic RF detector and an exemplary linear RF detector.
DETAILED DESCRIPTION
[0025] This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0026] The methods and systems described herein may be used in a transmission application where there is an amplification stage whose gain is controlled by a control loop. A diagram of one exemplary embodiment of such a system is illustrated in FIG. 1 . The system 10 of FIG. 1 may be, for example, a transmission module of a cellular telephone, personal digital assistant, etc. The exemplary system 10 includes a signal generation module 70 that includes signal generation circuitry and a controller module 80 that includes control circuitry. The signal generation module 70 and the controller module 80 may be implemented in one or more digital processors, and/or incorporate some analog circuitry. Amplification module 100 receives and amplifies the signals generated in the signal generation module, and delivers them to a transmitter 90 (such as an antenna) for transmission. Controller module 80 provides a gain control signal to amplification module 100 . Amplification module 100 includes a gain control loop that uses the control signal to determine the gain by which the signal is amplified for transmission.
[0027] As noted above, saturation of the amplification control loop can degrade performance of the control loop, leading to amplifier output that is not optimized FIG. 2 illustrates, in block diagram form, an exemplary amplification module 100 having circuitry to detect saturation (or the imminent onset of saturation) and, optionally, to apply a correction signal to correct saturation.
[0028] The amplification module 100 includes a power amplification circuit 60 , which includes power amplifier 102 having an input terminal 104 and an output terminal 106 . The power amplification circuit 60 also includes a RF detector 114 (which may be logarithmic or linear in its response) that samples the output of the power amplifier and provides feedback to an error amplifier 110 (optionally through a buffer or other amplifier, not shown). The output of RF detector 114 may also be provided (optionally through a buffer 118 ) to an output V OUT , which may be monitored, for example, by another module of the device 10 in which the amplification module 100 is deployed, such as the controller module 80 .
[0029] The error amplifier 110 also receives (either directly or indirectly via an injection circuit 40 discussed further below) as an input a loop control signal V SET which provides a setpoint for the gain of the power amplifier 102 . In one exemplary embodiment, loop control signal V SET provides a time-varying profile such as a sine wave or other ramping profile that the gain of the power amplifier, and therefore the power profile of the amplifier output, will follow. The output of the error amplifier 110 is a gain control signal V GAIN , provided to the power amplification circuit 60 to control the gain of the power amplifier 102 . Thus, in normal loop operation, error amplifier 110 outputs V GAIN such that the (optionally amplified) output of detector 114 is equal to the input control signal V SET . Error amplifier 110 may be configured as a proportional amplifier, integral amplifier, derivative amplifier, or any suitable combination of those elements in accordance with loop design requirements. As discussed further below in connection with FIG. 3 , error amplifier 110 may also include a high-current output stage, either integrated into the error amplifier, or as a discrete output stage.
[0030] The gain control signal V GAIN is also sent to a saturation detection circuit 20 that determines if saturation exists or is imminent. In one exemplary embodiment (discussed further below in connection with FIG. 3 ) saturation detection circuit 20 compares V GAIN with a threshold or reference voltage that is below the V GAIN value at which loop performance is noticeably degraded due to saturation, and if V GAIN exceeds that threshold or reference voltage, returns a signal affirmatively indicating saturation. In this way, the saturation detection circuit 20 can provide an unambiguous result (used to indicate, and in some embodiments to initiate correction of, saturation) when saturation is approaching, but before either the loop performance or the power amplifier performance has begun to degrade appreciably.
[0031] The saturation detection circuit, in one embodiment, provides a saturation indication signal 50 that indicates whether saturation exists. The saturation indication signal 50 may be, for example, a binary signal that is high when saturation exists and low when it does not. The saturation indication signal 50 may alternatively be any detectable offset voltage that distinguishes saturation from non-saturation, added to (or even subtracted from) V OUT of the detector 118 . The saturation indication signal 50 may be received by the controller module 80 , for example, and the controller module 80 may respond in some appropriate way. In some embodiments the controller module 80 responds, for example, by reducing V SET until the loop saturation is corrected.
[0032] In another embodiment, the amplification module 100 includes an offset generator circuit 30 which receives the saturation indication signal 50 provided by the saturation detection circuit 20 . The offset generator circuit 30 generates an offset voltage that is summed with V SET by offset injection circuitry 40 , to reduce the gain of the power amplifier. In one exemplary embodiment, the offset voltage generated by offset generator circuit 30 ramps to a value sufficient to bring the power amplifier control loop out of saturation. The offset generator circuit 30 may, in some embodiments, include circuitry that stops the ramping of the offset voltage when the reduction in gain of amplifier 102 is sufficient to bring the control loop out of saturation. In one exemplary embodiment, the offset generator circuit 30 includes circuitry, such as a capacitance, to hold the offset voltage after the ramp of the offset voltage is stopped. In embodiments in which the amplification module 100 is used in the transmission module of a device, such as a cellular telephone or a PDA, the offset generator circuit 30 may hold the offset voltage for the duration of the transmission burst. A reset signal may be used to clear the offset voltage prior to the commencement of the next burst. For example, in one embodiment, the reset is achieved by closing a switch in offset generation circuitry 30 that shorts to ground a capacitor holding the offset voltage.
[0033] FIGS. 3 and 4 illustrate in more detail certain exemplary embodiments of the system depicted in the block diagram of FIG. 2 .
[0034] FIG. 3 illustrates one exemplary embodiment of an amplification module 100 having a capability to detect saturation and to provide a detection signal that may be used to alert another device or component, for example controller module 80 , to the presence or imminence of loop saturation. As discussed further below, the detection circuit may be designed to provide an unambiguous indication of saturation (for example, a positive saturation indication signal) with whatever tolerance is desired; in some applications the detection circuit may respond when the loop is near saturation but not yet in saturation, while in others, the detection circuit may respond when actual saturation occurs. Throughout this disclosure, the term “saturation” is generally used to refer to any saturation or near-saturation condition to which an embodiment of the saturation detection circuit is designed to respond. In some embodiments, therefore, “saturation” may refer to a gain control signal exceeding a certain threshold above which saturation is expected to occur.
[0035] In the embodiment illustrated in FIG. 3 , the amplification module 100 includes a power amplifier 102 , which may include a plurality of cascaded gain stages. In the illustrated embodiment, for example, power amplifier 102 includes three cascaded gain stages, although other types of power amplifiers (for example, with more or fewer cascaded gain stages) may be used. The power amplifier 102 receives at input terminal 104 a signal to be amplified (such as a transmission burst) and produces at output terminal 106 an amplified output signal. The signal at input terminal 104 may be received, for example, from the signal generation module 70 of FIG. 1 , and the signal at output terminal 106 may be provided, for example, to the transmitter 90 .
[0036] Returning to FIG. 3 , the gain of power amplifier 102 is driven by V GAIN , which, in one exemplary embodiment, is coupled to power amplifier 102 through an inductor 108 to filter any ac components that may be present in the dc signal V GAIN . V GAIN is determined by the feedback network on the error amplifier 110 . The error amplifier 110 operates to keep V DET equal to the input signal V SET , which is the external control signal controlling the overall gain of amplification module 100 . In the embodiment illustrated in FIG. 3 , V GAIN is sourced by a FET 112 which is driven by the error amplifier 110 . An advantage of using FET 112 is that many operational amplifiers (such as high-precision operational amplifiers that might be desirable to use for error amplifier 110 in a control loop where precision control is desired) cannot source sufficient current to drive the power amplifier 102 . In one exemplary embodiment power amplifier 102 draws as much as 200 mA from the V GAIN drive. In the illustrated embodiment, FET 112 is a PFET, but it should be recognized that FET 112 can be replaced by other types of transistors such as an NFET or pnp bipolar transistors, or any like component that can provide the necessary current to drive power amplifier 102 . Additionally, FET 112 need not be a discrete component at all, but can be the output stage of an error amplifier 110 which is capable of sourcing the required current. In the embodiment of FIG. 3 , in which FET 112 is a discrete component, in order to ensure that V GAIN increases with an increase in V SET , V SET is applied to the inverting input of error amplifier 110 and the feedback signal (discussed further below) is applied to the non-inverting input of error amplifier 110 . It should be understood that where FET 112 is the output stage of the error amplifier 110 , rather than a discrete component, the inputs to the error amplifier 110 may be reversed to achieve a stable control loop.
[0037] As noted above, error amplifier 110 operates to keep V DET equal to the input signal V SET . V DET is a buffered and/or amplified version of the output signal from a RF detector 114 that samples the amplified signal at the output terminal 106 of the power amplifier 102 and provides a signal indicative of the magnitude of the signal at the output terminal 106 of the power amplifier 102 . In one exemplary embodiment RF detector 114 is a logarithmic (log) power detector, meaning that it outputs a voltage that is proportional to the log of the RF voltage at its input. Alternatively, RF detector 114 may, in certain embodiments, be a linear detector, producing an output voltage proportional to the RF voltage at its input.
[0038] In one exemplary embodiment, the output signal from RF detector 114 is provided to a pair of linear amplifiers 116 and 118 whose output signals are V DET and V OUT respectively. V DET provides the feedback for the power control loop. In certain embodiments, V OUT is used as the saturation indicator signal; V OUT and switch 128 are discussed further below. In one exemplary embodiment, amplifiers 116 and 118 are very closely matched, e.g., by appropriate selection of the amplifiers themselves and resistors 120 , 122 , 124 , and 126 , so that V OUT is equal to V DET as long as switch 128 is open. In one exemplary embodiment, resistors 120 and 122 are chosen to give amplifier 116 a suitable gain for closed-loop control of the power amplifier 102 via error amplifier 110 , FET 112 , and V GAIN . Generally speaking linear amplifier 116 may have unity gain, non-unity gain, or a derivative and/or integral component to its gain (achieved, for example, by adding one or more capacitors in parallel or in series with resistor 120 ). The optimal value for the gain of amplifier 116 will depend upon the sensitivity of RF detector 114 , and other loop parameters. (As discussed further below, the use of V OUT amplifier 118 is optional; it may be used in embodiments where it is convenient to have a saturation detection signal V OUT that is based upon the feedback signal V DET ; in certain embodiments the V OUT amplifier 118 is absent.) Additional components (not illustrated) may also be used in accordance with loop design principles in order to achieve desired loop performance. For example, the feedback network of error amplifier 110 may include a capacitor to achieve integration in the feedback loop.
[0039] In one exemplary embodiment, the saturation detection portion of the circuit illustrated in FIG. 3 (corresponding to saturation detection circuit 20 in FIG. 2 ) includes the comparator 130 , the current source 136 , the switch 128 , the amplifier 118 , and the resistors 124 and 126 . In the embodiment shown, the comparator 130 is a Schmitt trigger; in other embodiments comparator 130 may be any suitable comparator. Comparator 130 compares V GAIN to a voltage drop determined by current source 132 , resistor 134 , and battery voltage V BATT . The voltage drop may be selected based upon the parameters of FET 112 as follows.
[0040] In normal (non saturated) operation, V GAIN changes with V SET , adjusting the gain of the power amplifier 102 such that V DET =V SET . If V GAIN gets too close to V BATT , however, FET 112 (which, in one exemplary embodiment, is a PFET) enters an ohmic region, causing V GAIN —and hence the loop gain—to drop significantly. The saturation detector permits detection of the approach of this condition before V GAIN gets close enough to V BATT to cause the gain to drop.
[0041] The voltage at which the FET 112 —and hence the control loop—ceases to function is a property of the FET 112 . Thus, in one exemplary embodiment, the value of resistor 134 and/or of the current sourced by current source 132 are chosen such that the voltage drop across resistor 134 is equal to or slightly greater than the FET limit voltage. Thus, the output of the comparator 130 will change when V GAIN exceeds V BATT minus the voltage drop across resistor 134 —that is, when V GAIN comes within the FET limit of V BATT . (As noted previously, component 112 need not be a FET; it will be readily appreciated that the comparator activation condition may be selected analogously for whatever type of transistor is used to source V GAIN . Additionally, while in the illustrated circuit the comparator 130 is configured such that its output goes positive when V GAIN comes within the FET limit of V BATT , it should be appreciated that the comparator can be configured with the opposite polarity, provided its output distinguishes whether or not V GAIN exceeds the reference at the comparator's other input terminal.) In applications where loop saturation is particularly deleterious or where avoidance of saturation is particularly desirable for whatever reason, the resistor 134 and/or current source 132 may be selected so that the comparator is triggered well before V GAIN is high enough for the loop to actually reach saturation. In such a circuit some amount of peak power output is traded for the security of an assured avoidance of loop saturation. In other applications—for example, where the ramp profile defined by time variance of V SET is less critical, or in applications in which it is desirable to maximize the power output of the power amplifier 102 and the risk of a closer approach to saturation is acceptable—the resistor 134 and/or current source 132 may be selected to allow V GAIN to come closer to V BATT before triggering the comparator 130 . In this way sensitivity may be set to detect either an impending saturation or an actual saturation.
[0042] In the illustrated embodiment, V BATT is the DC voltage supplied by the battery of the device (such as a cell phone, personal digital assistant, etc.) in which amplification module 100 is deployed. It should be appreciated that V BATT may vary from device to device or even within a single device depending upon what battery is used, its state of charge, etc. In an alternative embodiment, comparator 130 compares V GAIN to a separate reference voltage V REF (not illustrated) rather than to a reference voltage based upon V BATT as in the embodiment illustrated in FIG. 3 . In such an embodiment V REF can be used as the input signal to comparator 130 instead of V BATT minus the voltage drop across resistor 134 . The voltage reference V REF in such an embodiment is then selected such that, at the lowest V BATT at which the circuit might operate, V BATT —V REF is large enough to keep FET 112 in the desired operating region; that is, FET 112 does not enter the ohmic region as long as V GAIN is less than V REF . In such an embodiment, comparator 130 will be triggered when V GAIN exceeds V REF , even if the circuit is deployed with a higher V BATT . Such an embodiment may be desirable where the circuit as a whole is designed to operate effectively at some minimum value of V BATT ; in such embodiments there may be little advantage in allowing V GAIN to go higher even if a higher V BATT is used. The voltage reference V REF may be provided externally to the amplifier module 100 ; by a voltage regulator on the same board as the amplifier module 100 ; by a current source applied across a resistor; or by any other suitable means of providing a constant reference voltage.
[0043] Regardless of which approach to generating a reference voltage is used, when saturation occurs or is imminent—when V GAIN approaches V BATT to less than the voltage drop across resistor 134 or when V GAIN exceeds whatever reference voltage V REF is used as the comparator input signal—the output signal from comparator 130 changes, closing switch 128 . When switch 128 is closed, current I OFF flows from current source 136 , causing a negative offset in the saturation detector output voltage V OUT . Thus, while (as discussed above) V OUT =V DET in normal non-saturated operation, when saturation occurs switch 136 closes and a step change occurs in V OUT . The current I OFF from current source 136 may be selected so that the change in V OUT is readily detected.
[0044] In alternative embodiments, the output signal from comparator 130 is itself used as the saturation detection signal, without the need for current source 136 , switch 128 , or V OUT amplifier 118 . As noted previously, there may be applications in which it is desirable or convenient to have a saturation detection signal V OUT that is based upon the feedback signal V DET ; and the illustrated configuration of current source 136 , switch 128 , and V OUT amplifier 118 is one way to achieve that. However, the comparator 130 output signal can itself provide a digital indication of saturation.
[0045] Whether the output signal from comparator 130 is used directly or converted into a step offset on the detector signal, the detection circuit shown in FIG. 3 converts the onset of saturation into an easy-to-detect step either in V OUT or in the output signal from comparator 130 , despite the fact that the onset of saturation may be difficult to detect directly in V GAIN or in the signal at the output terminal 106 of the power amplifier 102 . Referring back to FIG. 1 , the step in V OUT or in the output signal from comparator 130 may be detected by the controller module 80 that responds, for example, by lowering V SET until saturation ends.
[0046] The embodiment illustrated in FIG. 4 includes circuitry to both detect the saturation, and to respond to saturation and correct it. Like the circuit in FIG. 3 , the embodiment illustrated in FIG. 4 includes a power amplifier 102 whose gain is controlled by the output of a FET stage 112 , coupled through inductor 108 . A RF detector 114 samples the signal at the output terminal 106 of the power amplifier 102 , and the output signal from the RF detector serves as the feedback signal to the error amplifier 110 . The gain of the control feedback loop may be set as appropriate by amplifier 202 (analogous to amplifier 116 in FIG. 3 ).
[0047] As with the saturation detection circuit of FIG. 3 , the embodiment illustrated in FIG. 4 includes a comparator 130 , the output of which indicates when V GAIN comes within the FET limit of V BATT , signaling saturation. The output signal from comparator 130 indicates the presence of saturation and may be used to correct saturation as follows.
[0048] Under normal, non-saturated operation, a negligible amount of current flows through resistor 204 , and the voltage at node 206 is substantially the same as the gain setpoint V SET . In saturation, however, it is advantageous to modify the gain setpoint so that V GAIN , which controls the gain of power amplifier 102 , will also be reduced, pulling the amplifier 102 out of saturation. The circuit illustrated in FIG. 4 is one way to achieve that objective, with circuits corresponding to the offset generator circuit 30 and the injection circuit 40 of FIG. 2 .
[0049] In the embodiment illustrated in FIG. 4 , in response to the output signal from the comparator 130 indicating saturation, current source 208 is switched on. Because of capacitor 224 , this causes the voltage at the non-inverting input terminal of the amplifier 210 to increase, which turns on the transistor 212 and draws current through resistors 204 and 214 , pulling down the voltage at node 206 . Thus, using the output signal from the comparator 130 to control the current source 208 reduces the input signal to the error amplifier 110 when saturation is indicated. The result is that the circuit automatically applies a correction to the setpoint of the control loop, and hence automatically reduces the gain of the power amplifier 102 , pulling the amplifier 102 back out of saturation.
[0050] An advantage of using logarithmic (as opposed to linear) detection which is realized in the embodiment of the correction circuit illustrated in FIG. 4 is now described. When logarithmic detection is used, the control signal V SET may be reduced without affecting its overall profile (which, in one exemplary embodiment in which the amplifier module 100 is used in the transmission stage of a cellular telephone, is sinusoidal). Preserving the shape of the V SET profile may be important, for example, for compliance with cellular telephone specifications such as adjacent channel spectral emission and time mask boundaries. An exemplary curve of RF detector response versus the power output of amplifier 102 is shown in FIG. 5 for both logarithmic (curve 501 ) and linear (curve 502 ) detectors. Because the power output of the amplifier 102 varies according to the square of the RF voltage, the response curve 502 of a linear detector (which produces a detector signal proportional to the RF voltage) is exponential. On the other hand, the response curve 501 of the logarithmic detector (which produces a detector signal proportional to the log of the RF voltage) is linear.
[0051] Because the detector is in the control loop that controls the amplifier gain according to V SET , where a linear detector is used, attempting to apply a fixed offset correction would distort the response of the loop to a time-varying (i.e. sinusoidal) V SET profile. Because of the exponential response curve of the linear detector, the slope of the response differs at the high end and low ends of the power range. For a detector with the exemplary sensitivity illustrated in FIG. 5 , at power levels near saturation (near the top of an exemplary sinusoidal V SET profile), a nearly 100 mV correction to V SET is required to achieve a 0.5 dB power reduction. If that 100 mV correction is applied as a constant correction, however, at low output power (near the bottom of an exemplary sinusoidal V SET profile), the 100 mV correction to V SET would result in over 10 dB reduction of the output power. Thus, a simple dc offset correction to V SET could result in unacceptable distortion of the profile of the amplified signal. It should be appreciated that linear detection could be used, provided the correction signal applied at node 206 were multiplied to compensate for the nonlinearity in the V DET signal as a function of the power output of amplifier 102 , instead of simply added to V SET as an offset. In contrast, the simple additive properties of the control loop with logarithmic detection permit applying a correction to the loop control input signal without distortion of the control signal profile.
[0052] Returning to FIG. 4 , it is desirable for the circuit to stop modifying the gain setpoint provided to the error amplifier 110 when the loop is no longer saturated, so that the gain of the power amplifier 102 is not reduced more than is necessary to correct saturation. The embodiment illustrated in FIG. 4 achieves this objective as well with comparator 216 , which compares the voltage at node 206 with V DET . (Since V DET is the buffered and/or amplified output of RF detector 114 , V DET is directly representative of the output of the power amplifier. During amplifier saturation, V DET is a direct indication of the saturated power of the amplifier 102 .) The voltage at the negative input terminal of the comparator 216 is determined by current source 220 and resistor 218 . The output signal from the comparator 216 is high when the voltage at node 206 is greater than V DET minus the voltage drop across resistor 218 . Thus, the voltage drop across resistor 218 limits how far the voltage at node 206 will be reduced relative to V DET at saturation. Because of AND gate 222 , the correction to V SET will only occur when comparator 130 indicates saturation and comparator 216 indicates that the corrected V SET voltage (at node 206 ) exceeds V DET minus the threshold set by resistor 218 and current source 220 .
[0053] The appropriate threshold depends upon the properties of the circuit, such as the sensitivity of the RF detector 114 and the desired safety margin for maximizing the gain of power amplifier 102 while keeping it out of a saturated regime. In one exemplary embodiment, a 0.5 dB reduction below the saturation power of the amplifier 102 is generally sufficient to take the amplifier 102 out of saturation. In an embodiment having a typical detector sensitivity of 40 mV/dB, reducing V SET by 20 mV upon detection of saturation would be satisfactory. In such an embodiment current source 220 and resistor 218 may be chosen such that the voltage drop across resistor 218 , and hence the threshold at which the ramping of the correction ceases, is 20 mV.
[0054] The use of this threshold and comparator 216 to prevent the corrected V SET voltage (at node 206 ) from dropping too far below what is needed to correct saturation is advantageous because checking the corrected V SET directly can be faster than waiting for comparator 130 to register the end of the saturation. In particular, in the embodiment illustrated in FIG. 4 , the V SET input to the control loop is filtered by resistor 226 and capacitor 228 (in one exemplary embodiment, 1/RC˜300 kHz), to remove undesirable higher-frequency noise from the V SET input (such as noise from a digital-to-analog converter (DAC) providing V SET to the loop circuit). Because of this filter, detection of saturation on the signal at the output terminal 106 of the power amplifier 102 is considerably slower than using the corrected V SET instead. In alternative embodiments, this filter may not be required; in such embodiments the saturation correction may be added to V SET using any other way of summing voltage signals.
[0055] Even when the output signal from comparator 216 reflects that the voltage at node 206 has dropped enough to correct saturation, and shuts off current source 208 , capacitor 224 will hold the voltage to which it was charged while current source 208 was on. Thus, FET 212 will continue to draw current, keeping the voltage at node 206 at the reduced level relative to V SET that maintains the gain of power amplifier 102 at just below saturation. How long capacitor 224 can hold that state depends upon its capacitance; in one exemplary embodiment, in which the power amplification module 200 is used in the transmission stage of a wireless device, capacitor 224 may be chosen to hold most of its charge for the duration of a transmission burst.
[0056] Thus, comparing the exemplary embodiment illustrated in FIG. 2 with the specific exemplary embodiment illustrated in FIG. 4 , an exemplary offset generator circuit 30 comprises the current source 208 and the capacitor 224 that commence the ramping of a correction voltage in response to a positive signal from AND gate 222 . AND gate 222 in turn responds to a positive signal from comparator 216 , turning off the ramping of the correction voltage when the correction voltage reaches the desired maximum correction. Likewise, an exemplary injection circuit 40 comprises the operational amplifier 210 , transistor 212 , and resistor 214 that operate together to inject the offset into the control loop by altering the voltage at node 206 .
[0057] In the embodiment illustrated in FIG. 4 , OR gate 230 provides an optional additional way of triggering the current source 208 and applying a correction to the control signal V SET . In addition to the circuits shown in FIG. 3 and/or FIG. 4 that monitor a voltage saturation of the control loop, there may be other circuitry (not shown) that monitors the power amplifier 102 for the existence of saturation. An OR gate 230 supplied with an input I SAT allows a current limit monitor to alternatively trigger the saturation correction circuitry even when the saturation detection circuitry based upon V GAIN does not indicate saturation. I SAT may be, for example, a logical signal output by a current limit monitor to indicate saturation of a current flow somewhere in the loop. The use of one or more OR gates 230 can allow triggering of the saturation correction circuit upon any condition desired, even in the absence of voltage saturation.
[0058] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
|
A power amplification circuit includes a power amplifier, an RF detector, an error amplifier, a saturation detector, and an offset circuit. The power amplifier provides an amplified signal based on an input signal and a gain control signal. The RF detector provides a detection signal indicative of a logarithm of the power of the amplified signal. The error amplifier provides the gain control signal based on an amplification control signal and the detection signal. The saturation detector provides a saturation signal in response to the gain control signal differing from a reference signal by less than a first predetermined voltage. The offset circuit decreases a voltage level of the amplification control signal by up to a second predetermined voltage in response to the saturation signal and the amplification control signal differing from the detection signal by less than the second predetermined voltage.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to new methods and devices for placing stitches in relatively thick, moving tissue so that when the ends of the suture are drawn tightly together, the tissue within the suture is constricted and more particularly to methods and devices for the minimally invasive remote simultaneous and hemostatic placement of multiple horizontal mattress sutures centered circumferentially around a placed guide wire traversing through a tissue wound site that will subsequently be enlarged (to provide a passageway to facilitate a medical intervention) and then hermetically closed. An embodiment of the invention includes a hand actuated suturing instrument with multiple needles that drive through relatively thick engaged tissue each picking up an end of a strand of suture for the precisely oriented suture placement at predetermined depths of multiple concentric horizontal mattress sutures with pre-loaded pledgets. To enable accurate device placement on a potentially moving tissue structures, such as a beating heart, this suturing instrument incorporates a novel low profile pivoting or rotating mechanical alignment guide to enable controlled positioning of the distal end of the instrument at the desired location identified by a temporary guide wire traversing and centered on the pending access site. In accordance with another embodiment, to maintain reliable purchase (i.e., engagement) on such thick, moving tissue structures, this invention provides an additional mechanical means to accurately and securely engage the suturing instrument's suture placement distal end with the targeted tissue site. Examples illustrating novel methods of the use of this invention for the safe and secure closure of transapical heart access wounds and ascending aorta cannulation sites are also herein described.
2. Description of Related Art
Wounds in living tissues and organs are often created by physicians to provide a passageway or access to more internal structures for diagnostic and therapeutic interventions. Access wounds made in tissue structures that are thicker walled, not fixed in position (e.g., mobile or actively moving) or acting as barriers to hold pressurized fluids or gases can be more challenging to establish and close. Temporary guide wires are routinely positioned at proposed entry wound sites to provide a central target and guiding element for improved device placement accuracy during tissue access. For example, for access to the inside of the beating human heart, transmyocardial cannulation of the lateral left ventricle near the apex permits accessibility through the ventricular chamber to the region of the aortic root, the mitral valve and the left atrium. Another cardiac intervention example is the cannulation of the anterior ascending aorta to provide a site for antegrade passage of oxygenated blood during cardiopulmonary bypass. Guide wires can be installed to better enable transapical access to the moving, contracting left ventricle along with transmural access to the pulsatile ascending aorta. While a number of techniques and technologies already exist for closing various types of wounds, the need still exists for improved means for closing many tissue wounds created for advanced minimally invasive interventions. This need is critical for closing wounds accessed remotely through small openings, and especially, for securing wound closures of relatively thick tissues containing pressurized fluids, such as circulating arterial blood.
While this invention can be used for securing a wide variety of tissue structures, it is particularly useful for thicker, non-fixed tissue, as is often encountered in cardiac interventions. Since the invention has multiple potential cardiac applications, abridged heart anatomy highlights are presented next. The healthy human heart has four chambers: the right atrium, right ventricle, left atrium and left ventricle. This critical circulatory system organ is generally considered to have a “right” side, in which the right atrium receives from the body deoxygenated blood that the right ventricle pumps to the lungs and a “left” side, in which the left atrium receives from the lungs oxygenated blood that the left ventricle pumps into the systemic circulation. To maintain normal unidirectional blood flow and physiologic pressures, hearts have four valves: the right atrio-ventricular tricuspid valve, the pulmonary valve between the right ventricle and the pulmonary artery, the left atrio-ventricular mitral valve and the aortic valve between the left ventricle from the ascending aorta.
Over the past decade, a growing appreciation has developed for the potential to surgically intervene on the inside of the beating heart through small access wounds made directly through the muscular myocardial wall, typically near the pointed tip or apex of the anterior left ventricle. This so-called, Transapical Access approach has been proposed for interventions ranging from atrial endocardial ablations to mitral valve repairs to transcatheter aortic valve replacements. Transapical aortic heart valve replacement procedures are now in clinical use in Europe and North America.
A brief review of transapical endocardial ablations and mitral valve repairs include, for example, Lattouf (Pub. No: US2007/0270793 A1) proposed accessing the interior chamber of the left atrium via a penetrating access wound in the left ventricular apex wall, then retrograde through the chamber of the left ventricle and the mitral valve. After accessing the chamber of the left atrium and destroying the aberrant endocardial tissue, the apical closure was left to be performed by open traditional surgical techniques requiring a painful highly invasive thoracotomy incision in the chest wall. Lattouf also teaches (U.S. Pat. No. 6,978,176 B2) a method and devices for repair of the mitral valve's chordal attachments anchored within the left ventricle; they propose using a plastic plug for cannulation of the apical access wound, anchoring the new mitral chordal repair filaments and closing the apical wound. Gammie (U.S. Pat. No. 7,635,386 B1) showed a similar transapical approach to mitral valve repair with a different suturing device.
Transcatheter transapical aortic valve replacement is an area of concentrated research and significant clinical excitement at this time. At the May, 2010 American Association of Thoracic Surgeons, over twenty different presentations were offered on this subject; none offered minimally invasive or single port access or percutaneous technology for a least invasive route for transapical interventions. Reviews of the published literature on this subject demonstrate that no means currently exists clinically or proposed in research that has been publically offered for the minimally invasive closure of a transapical access site. Transcatheter transapical aortic valve replacement is currently reserved for the sickest cardiac patients, who are usually quite elderly, with multiple other co-morbidities and dying from otherwise inoperable critical aortic stenosis disease. A true minimally invasive access option would offer these highly compromised patients their best chance for a safe recovery.
While transcatheter transapical heart valve replacement products are already helping many patients, especially in Europe, until now an excellent means to remotely close transapical access wounds has remained elusive. Edwards® Lifesciences® provides the 31 Fr. Ascendra® transapical delivery system for 23 and 26 mm stainless steel bovine pericardium balloon expandable aortic valve xenografts; their full product launch is expected around 2012. In Europe, Medtronic® sells its Core Valve® re-valving system which incorporates a porcine aortic valve on an hourglass shaped nitinol frame, which is self expanding at body temperature. Medtronic's® Embracer® transapical delivery system products along with its Ventor® transfemoral versions are expected to be both released in 2014. The Medtronic® delivery system is 18Fr. and delivers valves that ultimately expand out to 20 and 27 mm. Medtronic® Melody® transcatheter pulmonary valve was first available in the United States in 2010. Other international companies, such as St. Jude Medical®, are reporting the development of transcatheter transapical valve products. To our knowledge, despite the clear need acknowledged for over the past half-decade, no one has yet reported an automated technology to facilitate truly minimally invasive transapical access site wound closure.
Many critically ill cardiac patients need their heart valves replaced, but no one would prefer a significantly large chest wall wound if a less traumatic, safe and effective alternative were clinically available. The first patient transcatheter aortic valve replacement occurred in France in 2002. Now, an estimated 50 transapical aortic valve replacement procedures occur each week throughout the world; all of these critically ill patients have required open chest surgery predominantly through the anterior lateral 6 th costal interspace. This open technique is to expose the front of (i.e., the anterior surface of) the beating heart to enable traditional hand suturing techniques for preparation of the heart transapical access site. Hybrid operating rooms offer the convergence of interventional cardiology techniques with the effectiveness of heart valve replacement, which until recently required the direct application of the skilled hands of a cardiac surgeon. This modern collaboration will remain limited until a safe and reliable technology and techniques for truly minimally cardiac transapical interventions are available.
Over the past 5 decades, millions of patients have benefitted from cardio-pulmonary bypass to enable extracorporeal oxygenation and pressurization of blood reintroduced back into the open-heart surgery patients circulation during arresting of the heart. A common technique to provide a conduit for returning oxygenated blood back into cardio-pulmonary bypass patient's systemic circulation involves cannulating the patient's ascending aorta with a tube carrying pressurized oxygenated blood to provide access to the systemic circulation above the cross clamped aortic root. A better, less invasive means is needed for installing perfusion cannula tubes and subsequently closing an aortic cannulation site wound.
Many minimally invasive cardiac surgical procedures still require an arrested heart to ensure an effective intervention and enable required visualization. The patient can benefit enormously from the much smaller chest wound utilized for a minimally invasive mitral valve repair and still receive a long-term therapeutic effectiveness. Hand sewing a traditional double purse string suture into the ascending aorta through a minimally invasive small remote port site using standard needle drivers is so challenging that for most surgeons it would not be worth the additional risks. To avoid the direct transmural cannulation of the ascending aorta minimally invasive heart surgery, several suboptimal products are available. For example, Edwards® Lifesciences® offers a long balloon catheter, called EndoDirect®. This product can be threaded retrograde through the pulsating femoral artery in the groin up beyond the arch of the aorta, where its balloon is infused to occlude the most proximal aorta and permit infusion of pressurized, oxygenated blood into systemic circulation during iatrogenic cardiac arrest. These balloons tend to migrate to less appropriate locations and frequently require repositioning. Any catheter traversing the arch of the aorta risks displacing embolic material and inducing stroke and other complications. The large transmural wound in the femoral artery typically requires open surgery for arteriotomy repair. A minimally invasively delivered device to secure an aortic cannula during cardio-pulmonary bypass and to subsequently hermetically close the transmural access wound site would be a significant advance.
With the Minimally Invasive Surgery (MIS) revolution, several available suture placement products have offered surgeons working through small access sites alternatives to hand suturing and hand knot tying. The use of non-specialized laparoscopic or thoracoscopic needle drivers presents significant limitations to ergonomic and accurate remote suture placement. MIS suturing devices, such as the LSI SOLUTIONS® S EW -R IGHT ® SR●5® (U.S. Pat. No. 5,431,666) and Running Device® (U.S. Pat. No. 7,407,505 B2) along with their TK-5® Ti-Knot® technology, Covidien's® Endostitch and Boston Scientific's® Capio®, provide shafted instruments for placing suture remotely. None of these products readily permits the accurate and simultaneous placement of concentric sutures at the tissue locations required in the applications.
Another related category of remote suturing instruments are usually called trocar wound closure devices, which are typically used to close the access site wound at trocar cannulation sites in the anterior abdominal wall. Typically these devices are suture mediated and their device distal ends enter the hole they are intended to close, which may be problematic in the above mentioned examples. These types of devices also typically close holes that are not associated with pressurized fluids, like blood. While many variations of trocar wound closure devices have come into use over the past two decades (U.S. Pat. Nos. 5,368,611 and 5,620,456), none are known to enable this transapical wound or aortic cannulation site preparation and closure.
Arteriotomy wound closure devices are another group of products that can be used to close some vascular wounds (e.g., a femoral artery percutaneous access site in the groin). Several suture mediated devices have been described to offer puncture wound closure options; U.S. Pat. Nos. 5,766,183; 6,368,334 B1; 6,641,592 B1 cover such technology. Alternatively, metal clips opposing wound edges U.S. Pat. No. 4,929,240 and absorbable plugs U.S. Pat. Nos. 4,852,568 and 5,342,393 were developed. Since these devices have also been available for some time, they appear unacceptable for the proposed related applications, including transapical access and aortic cannulation site closure.
A previous invention (Medical Instrument To Place A Pursestring Suture, Open A Hole And Pass A Guidewire, U.S. Pat. No. 7,731,727 B2) is somewhat similar in appearance to the current invention but has many distinct differences. The previous technology is remotely applied to thin walled tissue, which is sucked into place by vacuum for needle deployment using an integrated vacuum chamber; this tissue, such as stomach or rectal wall, needs to be highly conformal to avail itself to vacuum mediated deformation. Thicker walled structures may not be held reliably enough by vacuum alone. This previous instrument is not intended for use on tissue which is acting as a barrier to hold back pressurized fluids. The needles generally penetrate the full thickness of the tissue, which could cause immediate leakage of the pressurized fluid. Also the use of integrated cutting blade could cause an immediate hemorrhage, for example, in a beating heart. In addition, with this vacuum mediated technology, the guide wire is through the instrument at the end of the procedure after the purse string suture is placed and the transmural incision has been made; this is opposite of the current invention which traverses a pre-placed guide wire. In accordance with the present new invention for use with thicker tissue, the device end is inserted onto and follows an already existing temporary guide wire, which was previously installed to serve as a guide to the targeted tissue site. The previous technology does not teach a mechanical instrument-to-tissue alignment mechanism or an instrument-to-tissue secure engagement means based on compression between external and internal anchors. The previous technology was not intended for use with thick walled moving structures.
Despite a long recognized critical clinical need, no technology is known to exist that provides for the safe and effective minimally invasive closure of certain access wounds required for many therapeutic interventions, especially several related to cardiac procedures involving thicker tissue. This innovation now offers a new potentially highly effective and safe option for future patients.
BRIEF SUMMARY OF THE INVENTION
The surgical act of placing one or more filamentous structures through a single or multiple tissue sites is often called suturing or stitching. The filamentous structure itself, such as a string, cord or wire which can be made of a wide variety of materials including cotton, silk, plastic polymer, metal, etc., is referred to as a suture or stitch. The process and location of placing a single segment of suture through tissue is called “taking a bite” of tissue and “the bite”, respectively.
A horizontal mattress suture, alternatively also described as a U-stitch after its shape, involves employing a single suture for placing (i.e., running) two parallel tissue bites located usually at approximately the same depth in the tissue and separated from each other by an area of tissue. Usually the length of each tissue bite is approximately the same; therefore, the distance in tissue from where one end of the suture enters and exits the tissue is comparable to the distance spanned in adjacent tissue by the other end of the suture. The simplest horizontal mattress suture constructed can be described as an inverted three-sided flat bottomed U-shape or, more simply, an open box. The flat bottom of the open box is outside of the tissue, two segments of contiguous sutures are placed into the tissue perpendicular to the bottom of the open box, parallel to each other and passing out of the tissue in the same direction. By connecting (outside of the tissue) one exiting suture end to the other suture end, a four-sided, closed box, square or rectangular suture configuration is developed. By pulling the suture end tighter, the tissue held between the tissue bites is drawn or tightened together. Such a surgical technique is known for holding tissue or wounds in apposition for healing, for controlling bleeding or both.
The present invention reliably places two concentric horizontal mattress sutures around a targeted tissue site, which can be thicker walled and potentially moving. To protect a suture closure site, an additional element called a pledget is sometimes used. The pledget, also called a bolster, can be made from sturdy but soft and compliant pad-like material, such as Teflon cloth or rolled cotton linen. The pledget is placed between the narrow suture and the delicate tissue to avoid overly compressing the tissue with the suture during tightening and healing. The outside segment of both sutures at the flat bottom of the box passes over a central portion of a single four holed pledget held in the distal end of the device. The two ends of each suture pass through four corresponding holes in the pledget so that after taking the four tissue bites, the pledget is pulled down onto the tissue. To close the top of the box, a second single four holed pledget or alternatively two, two holed pledgets can be used to secure the free ends of the suture that have exited the proximal side of the tissue suturing site. The free ends of the suture pass through holes in the pledgets and provide a cushion buffer between the knotted suture connection and the underlying tissue. Knotting or otherwise securing the suture together essentially permanently closes the top of box and compresses together the tissue between the sutures and pledgets.
This is a novel suturing instrument for the remote placement of multiple pledgeted sutures centered circumferentially surrounding a targeted tissue wound site in relatively thick and less compliant tissue, such as the beating heart and aortic wall structures. Its sutures are precisely delivered to predetermined tissue depths and for pre-set distances. It does not require the distal end of the device to enter the wound site and can place the secure sutures around an existing guide wire before the access wound is fully opened. The suturing instrument includes a pistol grip style handle and a hand actuated lever for the precise placement of multiple pledgeted horizontal mattress sutures at the targeted access site, such as the anterior surface of the heart near its apex or the ascending aorta. The shaft of the instrument connects at its proximal end to the handle, which remains outside of the patient and in direct control of the surgeon. For example, in creating and closing a transapical access site, the shaft enters and traverses the patient's body at the left chest wall to deliver the device distal end where suture placement occurs to the targeted anatomic location (e.g., the apex of the beating heart).
This suturing instrument incorporates a low profile rotating, lockable, mechanical tissue alignment guide to enable more automatic controlled positioning of its distal end at its desired tissue location. The unlocked alignment mechanism rotates to allow the device end and its indwelling guide wire to pass more freely through narrow openings. When locked, the alignment guide provides a stable guide mechanism orienting the indwelling guide wire in a favorable position perpendicular to the tissue receiving jaw or welting trough of the suturing instrument for placing the sutures.
Further, this instrument provides a mechanical assembly to accurately and securely engage the distal end of this suture delivery instrument with the targeted tissue site. One tissue engagement assembly provides two linked balloons. When both balloons are filled and expanded, a tissue ridge or welt is compressed and sandwiched in the space between the balloons and the receiving gap or welting trough in the distal end of the instrument, thereby moving and re-conforming the targeted tissue into the most appropriate suturing position. An alternative tissue engagement assembly provides an expandable, mechanical assembly such as an internal hinged mechanical anchor that pulls tissue up into the suturing position against the welting trough in the undersurface of the suturing jaw, while an external compression spring exerts force on the top of the rotating alignment guide mechanism to further press the welting trough onto the tissue suturing site.
The results of current research involving this invention were recently submitted for presentation at the 2011 Society for Thoracic Surgery's Annual Conference. This submission is entitled, “Automated Remote Transapical Wound Closure System: Fresh Porcine Heart Bursting Pressure Study and Cadaver Endoscopic Demonstration.” Abridged highlights from this research submission include:
Transcatheter therapies are rapidly becoming mainstream for the treatment of structural heart disease. A transthoracic non-rib spreading single port option providing short distance, non-torturous direct access and including a secure transapical wound closure could further advance the benefits of this antegrade procedure.
Anterior left ventricular transapical access wounds in 50 porcine (47 ex vivo, 3 beating) and 10 human cadaver (8 open, 2 endoscopic) hearts were all successfully closed during the development of this hand activated remote suturing technology, which places two concentric pledgeted horizontal mattress sutures at precise depths ranging from 3 to 5 mm. Routine wound closure time was less than 2 minutes. For this bursting pressure study, a clinically available dilator was used to create transapical wounds through freshly harvested porcine hearts, in which automated (N=10) and hand sutured closures (N=5) were tested for leakage by pressurized saline infusion. This technology was used through a thoracotomy to close transapical wounds in the beating hearts of three non-survivor pigs. Human cadavers received automated transapical wound closures via this videoscopic single port technique.
All dilated then closed transapical access wounds sutured throughout this development project were hermetically closed. In the fresh porcine heart bursting pressure study, the first two hand sutured control closures received fully transmural sutures; both showed sustained leakage isolated to the suture tracks at 222 and 298 mm Hg mean peak. All other closures remained leak free despite high intraventricular infusion pressures (mean, min., max in mm Hg, automated: 327, 262, 348 and hand sutured: 303,222, 358) causing this ex vivo model's heart valves and atria to fail so that greater pressures could not be generated. Videos illustrate the extent of distention of the infused hearts tested in this study. The porcine beating heart closures were hemostatic. Endoscopic videos show the ease of use of this method for single port closure of transapical access sites in the human cadaver model.
Advanced customized tools are needed to assure cardiothoracic surgeons continue to lead in the critically important arena of minimally invasive therapeutic heart procedures. This automated transapical access wound closure technology and technique developed for endoscopic use was demonstrated to be ergonomic, fast, effective and highly reliable. The fresh porcine heart bursting pressure study showed these remote suture mediated wound closures remained hermetic beyond the supra physiologic infusion pressures intolerable to other structural elements of the hearts tested in this model. The early successful results illustrating hemostatic closures in porcine in vivo beating hearts and transthoracic totally endoscopic apical closures through a single port in the human cadaver model encourage further evaluation.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects, features and advantages of the invention will become more apparent from a reading of the following description in connection with the accompanying drawing, in which:
FIG. 1 is a perspective view of a preferred embodiment of a tissue suturing instrument of the present invention;
FIG. 2A is a perspective view of the tissue suturing instrument of FIG. 1 in which the right cover of the housing of the instrument is removed;
FIG. 2B is a blown up cross-sectional view of the shaft elements along Section A-A of FIG. 2A ;
FIG. 3 is a partially exploded perspective view of the tissue suturing instrument of FIG. 1 in which the handle halves are separated and the functional components for suture placement, mechanical alignment and tissue engagement are highlighted;
FIG. 4 is an exploded perspective view of the tissue suturing instrument of FIG. 1 ; except, to simplify this illustration for clarity, the suture and the tissue engagement assembly are omitted;
FIG. 5 is a perspective view of the tissue suturing instrument of FIG. 1 showing a curved distal end of the instrument;
FIG. 6A is a perspective view highlighting the needle drive components of FIG. 3 ;
FIG. 6B is a perspective view of the needle connecting fixture and the four needles;
FIGS. 6C and 6D are blown-up perspective views of the proximal and distal ends, respectively, of the needles of FIG. 6B ;
FIG. 7A is a perspective view showing the suture and pledget storage features of FIG. 3 ;
FIG. 7B shows the ferrules at each end of both strands of suture and both sutures incorporated through a single pledget and the indicator suture loops of FIG. 7A ;
FIG. 8A is a partial perspective view of the instrument of FIG. 1 highlighting the tell-tale suture loops proximal to the suture pad seen through the handle window indicating the ferrules are in their ferrule compartments;
FIG. 8B is a partial perspective view of the distal end of the instrument of FIG. 8A shown from underneath to highlight the ferrules in place in the distal side of the jaw;
FIG. 8C is a partial perspective view of the instrument similar to FIG. 8A except now the suture loops are distal to the suture pad as seen through the handle window indicating the ferrules are retracted back and showing the sutures spanning the welting trough of the instrument;
FIG. 8D is a partial perspective view of the distal end of the instrument of FIG. 8C shown from underneath to highlight the sutures now traversing the welting trough;
FIG. 9A is a partial perspective view of components of the pivoting mechanical alignment guide of the instrument of FIG. 1 showing the lock control knob fully forward and the mechanical alignment feature unlocked;
FIG. 9B is a partial perspective view of components of the mechanical alignment guide of the instrument of FIG. 9A showing the lock control knob in the fully back, locked position and the mechanical alignment guide rotated up and locked in place;
FIG. 10A shows a cross-sectional view of the unlocked mechanical alignment guide;
FIG. 10B shows a cross-sectional view of the locked mechanical alignment guide;
FIG. 11A shows a perspective view of tissue engagement assembly before activation of either balloon;
FIG. 11B shows a perspective view of the tissue engagement assembly with its internal engagement balloon expanded;
FIG. 11C shows a perspective view of the tissue engagement assembly with both its internal engagement balloon and its external engagement balloon expanded;
FIG. 12A shows a section view of FIG. 11A ;
FIG. 12B shows a section view of FIG. 11B ;
FIG. 12C shows a section view of FIG. 11C ;
FIG. 13A shows a partial perspective view of a second embodiment alternative tissue engagement assembly that provides a mechanical expandable hinged frame internal tissue engagement anchor and a compressive spring mechanism for external engagement;
FIG. 13B shows a section view of FIG. 13A ;
FIG. 14A shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism unlocked, both tissue engagement features not expanded, the suture and pledget in the loaded configuration and the needles fully retracted;
FIG. 14B shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism locked, both tissue engagement features not expanded, the suture and pledget in the loaded configuration and the needles fully retracted;
FIG. 14C shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism locked, both tissue engagement features expanded, the suture and pledget in the loaded configuration and the needles fully retracted;
FIG. 14D shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism locked, both tissue engagement features expanded, the suture and pledget in the loaded configuration and the needles partially advanced;
FIG. 14E shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism locked, both tissue engagement features expanded, the pledget in the loaded configuration, the ferrules, attached sutures and the needles fully retracted;
FIG. 14F shows a partial perspective view highlighting the instrument's distal end with the alignment mechanism unlocked with the inner tissue engagement balloon still expanded, the outer tissue engagement balloon not expanded and with the needles, ferrules and sutures fully retracted back, while the pledget remains in the loaded configuration;
FIG. 14G shows a partial perspective view presenting the instrument's distal end with the alignment mechanism unlocked with the inner tissue engagement balloon still expanded, the outer tissue engagement balloon not expanded while the suture is shown now paying out and the pledget is displaced from its loaded position;
FIG. 15A is a partial perspective view of the instrument's distal end with the loaded alignment guide being fed over a guide wire and co-axial to the common balloon tube towards a tissue site;
FIG. 15B is a partial perspective view of the distal end of the instrument in place on the tissue site with the tissue alignment feature in the locked up position and the internal balloon expanded;
FIG. 15C is the same as FIG. 15B except now the external balloon is also expanded to compress the welting trough to the tissue held between the two expanded balloons;
FIG. 15D is a partial perspective view showing the welting trough in place compressed between the balloons; hidden lines are used to indicate the needles passing through the tissue;
FIG. 15E is similar to FIG. 15D except now the hidden lines indicate sutures that now traverse the tissue bite;
FIG. 15F shows the distal end of the instrument with the mechanical alignment feature in the unlocked position being pulled away over the common balloon tube and guide wire from the tissue site with the suture paying out and the pledget coming down onto the tissue;
FIG. 15G shows the tissue closure site after complete removal of the instrument distal end with the pledget in place, the proximal sutures exiting the tissue, and the internal balloon still expanded in place;
FIG. 15H shows the wound closure site with both pledgeted horizontal mattress sutures secured in place at the targeted tissue site;
FIG. 16A is an illustration of thorax of an elderly man with the rib structures highlighted overlying a silhouette of the heart;
FIG. 16B is the same elderly man's thorax now with the rib structures removed to highlight the location of the heart in the human chest;
FIG. 17A is the schematic representation of the human heart with a guide wire entering the apical “bald spot” on the left anterior surface of the left ventricle;
FIG. 17B shows the distal end of the instrument of the present invention in place over the guide wire secured against the apex of the left ventricle, prior to expanding the external balloon;
FIG. 17C shows the closed apical access site secured between the pledgeted horizontal mattress sutures;
FIG. 18A is a schematic of the human heart with a guide wire shown entering the anterior surface of the ascending aorta;
FIG. 18B shows the distal end of the instrument of the present invention positioned onto the anterior surface of the ascending aorta prior to expanding the external balloon;
FIG. 18C shows the pledgeted double mattress suture wound closure site on the anterior ascending aorta.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with a presently preferred embodiment of the invention, a remote suturing instrument is provided for the precise placement of multiple pledgeted horizontal mattress sutures at a guide wire targeted location in a predetermined orientation, depth and length for securing thicker, less compliant tissue structures. An embodiment of the innovation disclosed here includes a multiple needle drive feature along with a pledgeted suture storage and release concept, a rotating tissue alignment guide mechanism, which includes an extended tube, and two alternative mechanical tissue engagement assemblies (one incorporating balloons and the other a hinged anchor and compression spring) to better hold and position the tissue for suturing.
FIG. 1 is a perspective view of a tissue suturing instrument 10 in accordance with a first embodiment of the present invention. A pistol grip style handle assembly 20 is constructed from a right handle portion 22 and a left handle portion 24 which are preferably made of an injection molded plastic or the like and to which subsequent components are attached. An elongated shaft tube 34 extends proximal from the handle to the distal end 32 of the instrument at which a tissue receiving jaw or welting trough 32 A is located. A sliding lock control knob 82 is disposed on the proximal end of shaft tube 34 and can be slid towards the handle to lock a rotating mechanical tissue alignment guide 46 in its upward orientation. A suture viewing window 62 is preferably located on the top of handle 20 as is described in more detail below.
Now referring to FIGS. 1-4 , certain aspects of the illustrated suturing technique using needles and suture attached to ferrules of instrument 10 may be similar to that shown in U.S. Pat. Nos. 5,431,666; 5,766,183; 6,997,931 B2; 7,731,727 B2 and European Patent No. EP 0669101, filed Feb. 23, 1995 and granted Oct. 14, 1998, which are incorporated by reference herein and used in the S EW -R IGHT ® SR●5® and Running Device® and ESD™ products manufactured by LSI SOLUTIONS, Inc. (formerly LaserSurge, Inc.) of Victor, N.Y.
FIG. 2A is a perspective view of the tissue suturing instrument of FIG. 1 in which the right handle portion 22 of the housing of the instrument is removed to illustrate internal components. Note Section A-A of FIG. 2A is shown in cross section FIG. 2B . FIG. 3 is a partially exploded perspective view of the tissue suturing instrument of FIG. 1 in which the handle halves are separated highlighting the functional components for needle delivery, pledgeted concentric double mattress suture placement, rotating mechanical tissue alignment and a balloon assembly for enhancing tissue engagement. FIG. 4 is an exploded perspective view of the tissue suturing instrument of FIG. 1 .
A lever 64 configured to be operated by the fingers of a user while grasping handle 20 provides for the extension and retraction of inner needles 56 and outer needles 58 of the instrument 10 . Distally, an elongated shaft tube 34 , shown here as rigid, but which may also be flexible, protrudes from the handle assembly 20 . The housing of the handle assembly 20 has a body shaped like a pistol having a handle portion made of a two-piece construction of molded plastic components right handle 22 and left handle 24 . Two pairs of elongated inner and outer needles 56 and 58 , which may be made of metal, such as surgical stainless steel, extend from housing 20 through the shaft tube 34 into the tissue engaging distal end 32 . Each of the inner and outer needles 56 and 58 has a non-tissue engaging end, the proximal attachment ends 56 A and 58 A, in the housing that are attached by gluing, welding, brazing or other such means into four corresponding holes in a needle attachment fixture 42 . This needle attachment fixture 42 is fixed to a rotatable axle 42 B using a slender connector shaft 42 A.
The suturing instrument 10 includes an actuator member 64 preferably including a lever having two lever pins 64 A extending into holes 22 A and 24 A in the sides of housing right and left handles 22 and 24 respectively, upon which pins the actuator member is pivotally mounted in the housing. A portion of the actuator lever 64 ( FIGS. 3 and 4 ) extends through lever openings 22 G and 24 G ( FIG. 4 ) in housing 20 to enable pivotal movement about pins 64 A. An extension spring 66 is provided which hooks at one end in a spring attachment notch 64 E of actuator lever 64 and is connected at the other end around a handle spring post 24 E, which extends into a handle post receiving pocket located in the side of housing right and left handles 22 and 24 respectively, such that the actuator lever 64 is spring biased to retain actuator lever 64 normally in a forward position, as shown for example in FIG. 1 . FIG. 3 illustrates the balloon tissue engaging assembly 90 , which provides a common balloon tube 94 attached to a common hub 94 a which communicates approximately with three ports; namely the guide wire port 92 , the internal balloon port 96 A and the external balloon port 98 A. Internal balloon 96 and external balloon 94 are attached to common balloon tube 94 proximal to its distal open end 94 B.
A slotted axle receiver 64 B is formed in the actuator lever 64 and is shaped to receive the axle 42 B of the needle attachment fixture 42 and its connector shaft 42 A. The inner and outer needles 56 and 58 are driven forward by an operator pulling actuator lever 64 to pivot on lever pin axle 64 A of actuator lever 64 within lever openings 22 G and 24 G. Shaft slot 64 C ( FIG. 3 ) is provided for connector shaft 42 A to allow connection and rotation of the needle attachment fixture 42 about its axle 42 B. While the lever illustrated is presently preferred, other mechanisms, such as a linear push-pull knob, a trigger or buttons, may be used.
With its right handle half 22 shown removed and its left handle half 24 shown in place, FIG. 2A best illustrates the relationship between the handle housing 20 and the elongated shaft tube 34 . Note the winged shaft connector 72 nested in left handle 24 with its wing 72 A on the right exposed along with its suture hole 72 B. The unexposed left shaft connector wing engages in a corresponding connector wing opening 24 D in left handle 24 , which is best seen in FIG. 4 . The winged shaft connector 72 may be attached to the elongated shaft tube 34 by glue, fasteners or other such means. To hold the shaft 34 within the handle 20 , the protruding wings 72 A of the shaft connector 72 engage the corresponding openings 22 D (not shown) and 24 D of handles 22 and 24 . At its interface with handle assembly 20 , elongated shaft tube 34 exits through shaft openings 22 B and 24 B. Also contained therein, as shown in FIG. 2B , are the inner needles 56 and outer needles 58 , suture storage tubes 38 with inner suture 52 and outer suture 54 , along with lock control tube 84 and lock control wire 86 . Suture passes through suture passage openings 22 F and 24 F and handles 22 and 24 , respectively.
The partially exploded perspective view of FIG. 3 highlights the major functional elements of the tissue suturing instrument 10 , which include the handle assembly 20 , a shaft tube assembly 30 , a needle drive and suture, pledget storage assembly 40 , a rotating mechanical alignment guide assembly 80 , and a balloon tissue engaging assembly 90 , which enable, respectively, pledgeted suture placement, more automated tissue alignment guidance and enhanced tissue engagement, all oriented over a guide wire placed through the targeted tissue. A clear plastic suture viewing window 62 revealing a compressive suture pad 76 gently holding the proximal tell-tale suture indicator loops 52 B and 54 B is shown in position relative to handle 20 .
FIG. 4 is a fully exploded, perspective view of the tissue suturing instrument 10 showing its right handle 22 , left handle 24 , needle actuating lever 64 and its extension spring 66 ; however, the suture and balloon tissue engagement assembly are removed from this drawing for illustration clarity. The disassembled shaft tube assembly 30 comprises, from distal to proximal ends, a distal end 32 , an elongated shaft tube 34 , four needle guide tubes 44 , a lock control tube 84 and two suture tubes 38 . The lock control wire 86 is connected at its proximal end 86 A to the sliding lock control knob 82 and bent at its distal end to engage the cam track 46 A of the rotating mechanical tissue alignment guide 46 .
FIG. 5 is a perspective view of the instrument 10 similar to FIG. 1 now shown having an elongated shaft tube 34 and an alternative distal end 36 that is bent, flexible, malleable or steerable as indicated at the bent section 36 A. A non-straight or non-rigid shaft enables access to many potentially clinically relevant sites that are not reachable by straight or rigid instruments.
A primary function of this embodiment of the invention is to enable the accurate placement of two pledgeted horizontal mattress sutures at controlled depths in thick tissue; the individual components for this critical function are best seen isolated in FIG. 6A through FIG. 8D . A horizontal mattress suture, sometimes alternatively called a U-stitch, is created by enclosing a tissue location with a single stitch.
Now referring to FIGS. 6A-6D , the presently preferred embodiment of the invention uses two pairs of inner and outer needles 56 and 58 passing through an opening or welting trough 32 A in a tissue receiving jaw in the distal end 32 . Tissue appropriately held in this trough would receive four tissue bites and could thus accommodate two bites each for the two (or more) mattress sutures. Bite depths depend on location of the passing needle relative to the top of the tissue welt and to the tissue compression within the jaw. For example, for closure of the apex in the heart, one preferred device configuration has two inner needles 56 traveling 9.0 mm apart at a tissue depth of 4.0 mm across a tissue span of 9.5 mm. The two outer needles 58 are 13.2 mm apart from each other (2.1 mm apart from the adjacent corresponding inner needles) and pass at a tissue depth of 5 mm across 13.1 mm of tissue.
The distal ends of both sets of needles 56 B and 58 B engage and pick up both ends of the sutures by engaging their corresponding ferrules 52 D and 54 D ( FIGS. 7A and 7B ). Once the needles pass completely through the tissue and are fully advanced into the ferrules, the ferrules with their attached sutures are now secured to the needles, so that the retraction of the inner and outer needles 56 and 58 back through the tissue also pulls the inner and outer sutures 52 and 54 back through the tissue at the targeted site.
The needle advancement and retraction drive mechanism is isolated in FIGS. 6A-6D . The two inner needles 56 are shown here attached to the top two holes of the needle attachment fixture 42 at the proximal attachment ends 56 A of the needles. The inner needle distal ends 56 B lie between the outer distal ends 58 B of the two outer needles 58 . Outer needles 58 connect to the two lower holes of the needle attachment fixture 42 at their proximal attachment ends 58 A. Force or squeezing on the lower half of the lever 64 directed toward the handle causes rotation about the lever pins, axle 64 A. Forward pressure on the needle attachment fixture axle 42 B by the slotted axle receiver 64 B is translated by connector shaft 42 A to drive the needle attachment fixture 42 forward along with the top of lever 64 upon lever squeezing. The needle attachment fixture 42 attached by its shaft 42 A to its axle 42 B can maintain a substantially horizontal orientation while being driven forward by rotating in the slotted axle receiver 64 B of lever 64 .
Release of lever 64 causes counter rotation about lever pins, axle 64 A augmented by extension spring 66 . Needle attachment fixture 42 then pulls its connected inner and outer needles 56 and 58 (along with their ferrules and sutures) back to the initial starting retracted position.
The needles are constrained within the elongated shaft tube 34 and the distal end 32 of the instrument so that translational forces extended on the proximal needle attachment fixture 42 cause the distal ends 56 B and 58 B of the inner and outer needles 56 and 58 to advance from their proximal retracted position across the tissue receiving jaw and through any tissue held within this trough. The distal ends 56 B and 58 B enter into the ferrules 52 D and 54 D (shown in FIGS. 7A and 7B ) held in their ferrule compartments 32 B (shown in FIGS. 8B and 8D ) on the distal side of the tissue engaging jaw or welting trough 32 A.
FIG. 7A highlights the suture storage capacity of this preferred embodiment. Note, for the purpose of clearer illustration, all four ferrules 52 D and 54 D are shown outside of their ferrule compartments 32 B (where they would actually be located prior to pick up). The suture pad 76 held between the clear suture viewing window 62 and the space in the top of handle 20 holds suture indicator loops 52 B and 54 B in place by mild compression. The suture pad 76 holds the suture indicator loops 52 B and 54 B while maintaining tension on the suture segments to keep the distal ferrules 52 D and 54 D securely in place in their ferrule compartments. Movement or shortening of suture indicator loops 52 B and 54 B is seen through window 62 thereby indicating needle retraction, successful ferrule pick up and that the corresponding sutures 52 and 54 have been pulled through the tissue engaging jaw 32 A. The elongated shaft tube break-out segment of FIG. 7A , shows the suture storage tubes 38 along with inner and outer sutures 52 and 54 . The inner and outer sutures 52 and 54 again are shown in the suture passage hole 72 B of the winged shaft connector 72 .
FIG. 8A illustrates a partial top view of the device showing the indicator loops 52 B and 54 B held by the suture pad 76 beneath the clear suture window 62 . Note all four suture loops 52 B and 54 B are on the proximal side of the suture pad 76 indicating the ferrules are in their compartments. FIG. 8B is a partial end view of the distal end of the instrument of FIG. 8A . This view shows all four ferrules 52 D and 54 D still held within their ferrule compartments 32 B.
FIG. 8C shows the altered, more distal location of the suture indicator loops 52 B and 54 B relative to the suture pad 76 indicating that the suture has now passed through the tissue engaging jaw 32 A in the distal end 32 . By pulling the ferrules 52 D and 54 D, the distal ends of each inner and outer sutures 52 and 54 pass through the tissue engaging jaw 32 A, and the indicator loops 52 B and 54 B of the corresponding sutures are moved distally in the same direction as the movement of the sutures through the elongated shaft tube 34 . FIG. 8D shows four segments of inner and outer sutures 52 and 54 now spanning the welting trough in the jaw 32 A of the distal end 32 .
FIGS. 9A-10B and FIGS. 11A-13B next address the components of the mechanical tissue alignment guide and the tissue engagement assemblies, respectively.
FIGS. 9A and 9B illustrate the pivotal mechanical alignment guide of the instrument of FIG. 1 . Note that the right side of the distal end 32 has been removed to better reveal the functional components of this tissue alignment mechanism. This novel alignment guide integrated into this device permits the aligned passage of the instrument over a pre-placed temporary guide wire centered in the protruding guide nipple 46 B (shown separated from 46 in FIG. 4 ) of the rotating mechanical tissue alignment guide 46 . This rotation is important because the end of the device 10 may need to traverse a narrow access channel, such as the space between non-retracted ribs. With a rotating alignment guide in the end 32 of this device, the guide wire within the mechanical alignment guide can pass longitudinally through narrow openings in the body; if the mechanical alignment guide did not rotate and was held in the up, perpendicular orientation, the guide wire would also be held perpendicular (normal or 90 degrees) relative to the long access of the shaft, necessitating a larger access opening.
In FIGS. 9A-9B , the elongated body shaft tube 34 (shown shortened) connects the distal end 32 to the handle 20 (not shown) via the winged shaft connector 72 . Connected to the elongated shaft tube 34 is the proximal lock control tube holder fixture 88 , which fixes the proximal end of the lock control tube 84 inside of the elongated shaft tube 34 and is best shown in FIGS. 10A and 10B . The sliding lock control knob 82 slides toward the handle, which is here represented by the winged shaft connector 72 . The sliding lock control knob 82 is connected to the lock control wire 86 at the lock control wire proximal end 86 A; also best seen in FIGS. 10A and 10B . By moving the sliding lock control knob 82 and its attached lock control wire 86 toward the handle, the lock control wire moves away from the proximal lock control tube holder 88 and its connected lock control tube 84 . A passageway exists in the distal end 32 for the lock control wire 86 which has a distal bent end 86 B that engages a cam track 46 A integrated into the rotating mechanical tissue alignment guide 46 . When unlocked, the rotating mechanical tissue alignment guide 46 partially rotates about its axle 48 .
FIG. 9B illustrates the same features as FIG. 9A except now the sliding lock control knob 82 is moved proximally, pulling its attached lock control wire 86 also proximally thereby causing the rotating mechanical tissue alignment guide 46 to rotate and lock in place with the lock control wire distal bent end 86 B engaging the straight part of the cam track 46 A.
FIGS. 10A and 10B are the cross-sectional views corresponding to FIGS. 9A and 9B ; these views better illustrate the mechanism in which the sliding lock control knob 82 attached to the lock control wire 86 moves relative to the proximal lock control tube holder 88 and the lock control tube 84 . In FIG. 10A , the mechanical tissue alignment guide 46 is shown rotated down in the unlocked position with the integrated protruding nipple 46 B facing forward. As best seen in FIG. 10A , the distal bent end 86 B runs in a curved portion of the cam track or radially about the rotating alignment guide axle 48 so that the mechanical tissue alignment guide 46 moves freely when the lock control wire distal bent end 86 B is in the forward unlocked position. In FIG. 10B , with the distal bent end of the lock control wire 86 B now pulled back by moving the sliding lock control knob 82 toward the handle, the rotating mechanical tissue alignment guide 46 is fixed in the up position with its integrated protruding nipple 46 B oriented facing down, perpendicular to the long axis of the distal end 32 and generally centered within the tissue receiving jaw or welting trough 32 B and pointing directly towards the surface of the targeted tissue (not shown).
FIGS. 11A-12C show the components of a preferred embodiment of a balloon-based tissue engaging and compressing assembly of this device. FIGS. 13A and 13B show an alternative tissue engagement assembly providing an internal expanding hinged frame and an external compression spring. Either tissue engagement assembly of this invention allows the tissue to be compressed within the tissue engaging jaw 32 A of the device using mechanical forces applied to the tissue to form a welt and better enable needle passage. This mechanical tissue engagement approach permits the distal end to form a welt and hold tissue even if the end of the device cannot be pushed down upon that tissue due to its remote location.
FIG. 11A shows the distal end 32 attached to the end of the elongated shaft tube 34 . In FIGS. 11A-11C , the right side of the distal jaw is partially removed to better illustrate functionality. The rotating mechanical tissue alignment guide 46 is shown locked into the up and perpendicular position. A common balloon tube 94 with both balloons not expanded is shown passing parallel along the elongated shaft tube 34 , along the distal end 32 of this device and passing through the downward facing integrated protruding nipple 46 B of the rotating mechanical tissue alignment guide 46 . This common balloon tube 94 follows over an existing guide wire (not shown), which will be further addressed starting in FIGS. 15A-15H .
FIG. 11B shows the same features as FIG. 11A except now the internal balloon 96 is expanded on the distal side of the rotating mechanical tissue alignment guide 46 ; when in actual use, internal balloon 96 would be positioned internal to the targeted tissue.
FIG. 11C shows the same features as FIG. 11B , but now the external balloon 98 is expanded to draw the internal balloon feature 96 back toward the distal end 32 . By inflating both the internal 96 and external 98 balloons, the jaw welt forming trough 32 A is sandwiched on top of the targeted tissue between the balloons.
FIGS. 12A-12C are cross sections corresponding to the previous drawings. These illustrations highlight the relative location of the common balloon tube 94 and its distal end 94 B. They show the elongated shaft tube 34 relative to the distal end 32 and the common balloon tube 94 passing through the now downward oriented integrated protruding nipple 46 B of the rotating mechanical tissue alignment guide 46 in the up and locked position.
FIG. 12A shows the common balloon tube 94 with both balloons not expanded. FIG. 12B shows the same as FIG. 12A except now the internal balloon is expanded. FIG. 12C shows the same as FIG. 12B except now the external balloon 98 is also expanded. The expansion of the external balloon 98 draws the internal balloon 96 and the common balloon tube distal opening 94 B back up towards the jaw. When the tissue is sandwiched between the two balloons 96 and 98 and the welting trough 32 A of the distal end 32 , the tissue is compressed in the desired location for forming a welt and ensuring adequate tissue bites for suturing.
FIGS. 13A and 13B provide a perspective view and a cross-sectional view, respectively, of an alternative tissue engagement mechanism assembly embodiment. FIG. 13A shows the elongated shaft tube 34 attached to distal end 32 with its right side segment partially removed for illustration. The mechanical alignment guide 46 is in the up and locked position with its integrated protruding nipple 46 B facing the tissue site. Now, however, instead of having a balloon internal tissue engagement means, an internal hinged frame mechanical expander anchor 102 is provided in this embodiment. The expander anchor 102 shown here is a slit tube with living hinges which when under compression expands radially outward. Tension in the proximal direction on the push-pull conduit internal mechanical expander 102 A of the expander anchor 102 causes shortening of this hinged frame mechanism, so that the hinged frame segments expand outwardly creating an internal anchor 102 . The push-pull conduit 102 A traverses through another conduit, the internal hinged frame mechanical expander conduit 102 B, which travels inside of the external compression spring tube 104 A. That spring tube 104 A is connected to an external compression spring 104 . By pulling on the push-pull conduit internal mechanical expander 102 A and holding the conduit 102 B, the internal hinged frame mechanical expander anchor 102 opens and draws the tissue up into the welting jaw. By pushing on the external compression spring tube 104 A, the external compression spring 104 pushes distally out on the exposed top of the alignment guide 46 of distal end 32 so tissue is pushed and pulled into the tissue receiving trough 32 A.
Next the features of the present invention will be shown together to illustrate the coordination of suturing, alignment and engagement component functionality. For clarity, FIGS. 14A-14G will not include an element to represent a segment of tissue.
FIG. 14 shows a partial perspective view of the handle and a more blown up distal end view of the instrument of FIG. 1 . This series of drawings utilizes the common balloon tube 94 mediated assembly embodiment as a tissue engagement assembly. Handle 20 is shown with a suture viewing window 62 and suture pad 76 . In FIG. 14A , the sliding lock control knob 82 is shown in the unlocked position. Lever 64 is shown in its forward position. The common balloon tube 94 is shown coursing through the tissue alignment guide 46 of the distal end 32 , the mechanical alignment guide 46 is pointed with its nipple 46 B (not seen in this view) directed generally forward along the long axis of the instrument end. The common balloon tube 94 is shown going through the mechanical alignment guide 46 with its distal open end 94 B now outside of the device. Inner and outer sutures 52 and 54 are shown in their loading position along with a four-holed pledget 78 .
FIG. 14B is much like FIG. 14A except now the sliding lock control knob 82 is pulled back and the rotating mechanical tissue alignment guide 46 has been rotated up and locked so that the protruding guide tube (not seen) projects downward towards and perpendicular to the tissue surface. The common balloon tube 94 is now oriented generally perpendicular to the jaw, where it is most useful in wound site alignment for pulling the tissue directly into welting trough 32 A. FIGS. 14A and 14B best illustrate so far why a rotatable alignment guide provides better access through narrow spaces; the vertical profile at the distal end 32 is much lower in the configuration shown in FIG. 14A than it is in the configuration shown in FIG. 14B . In FIG. 14A , the orientation of common balloon tube 94 within the distal end 32 can be appreciated to permit longitudinal passage through a narrow space. Whereas in FIG. 14B , with the rotating mechanical tissue alignment locking guide 46 now locked in its up position, the vertical height necessary to pass this instrument over a perpendicular oriented guide wire through a narrow space (such as between ribs) would be much greater.
FIG. 14C follows FIG. 14B but now shows both the internal balloon 96 and the external balloon 98 expanded. The actual sequence of use of this device would have the internal balloon filled first, and the external balloon filled next, to optimize compression of the device onto the tissue. The rotating mechanical tissue alignment guide 46 is locked up and the other elements are in their loaded positions.
FIG. 14D now illustrates that lever 64 is partially squeezed and the needle tips 56 B and 58 B are partially entering the tissue receiving jaw space 32 A. If tissue was in the jaw's welting trough 32 A, these needles would penetrate that tissue.
FIG. 14E shows the same configuration and function as 14 D except now the needles have traveled fully forward, entered the ferrules held in the ferrule compartments and have been pulled back along with their attached sutures through the jaw. FIG. 14E shows inner and outer sutures 52 and 54 traversing the trough 32 A, after being pulled back with their attached ferrules on their retracted needles. In actual use, the needles, ferrules and sutures would pass through a welt formed in the tissue.
FIG. 14F shows the same of configuration as FIG. 14E except now the external balloon has been unexpanded and the sliding lock control knob 82 has been pushed back forward thereby releasing the rotating mechanical tissue guide 46 so that it can now swing freely. In 14 F, the distal end 32 of the device can be pulled away from the targeted tissue site and the still expanded internal balloon. FIGS. 14E and 14F show the suture indicator loops 52 B and 54 B are now distal to the suture pad 76 .
The final illustration of this functional series demonstration, FIG. 14G , shows even a larger view of the distal end 32 . The suture indicator loops 52 B and 54 B indicate even further payout of the suture. While the internal balloon 96 is still up, the device distal end 32 is pulled away from the proposed wound site leaving the four suture bites in place and permitting the four-holed pledget 78 to release from its loaded position at the far end of the device distal end 32 . The suture passage slot 32 C is well seen here in the distal end 32 with four suture segments passing through it along with both integrated suture storage tubes 38 .
FIGS. 15A-H are similar in their contents to the last series, FIGS. 14A-14G , except in these illustrations a guide wire 122 is shown going through a planar tissue sample segment 124 .
FIG. 15A shows the distal end 32 advancing with the common balloon tube 94 passing through the unlocked rotating mechanical tissue alignment guide 46 , passing over a guide wire 122 , toward a planar tissue sample 124 which is also traversed by the guide wire 122 . Sutures and needles are in their loaded pre-activated position.
FIG. 15B shows the instrument of FIG. 15A now with its rotating mechanical tissue alignment guide 46 locked in the upright position, the nipple entering the wound site, the common balloon tube 94 passing through a planar tissue sample structure 124 , and the internal balloon 96 inflated.
FIG. 15C shows the next step in which the external balloon 98 is now inflated. With both the internal and external balloons 96 and 98 inflated, the planar tissue sample 124 conforms to a zone of tissue compression 124 A to form a welt through mechanical engagement with the welting trough 32 A and the internal balloon 96 .
FIG. 15D illustrates with hidden lines how the inner and outer needles 56 and 58 could pass through the welted zone of tissue compression 124 A now engaged in the welting trough of the jaw. FIG. 15E illustrates with hidden lines, the needles are now retracted back and sutures 52 and 54 are traversing the four suture bites in the targeted tissue.
FIG. 15F illustrates the distal end 32 with the rotating mechanical tissue alignment guide 46 unlocked, the external balloon 98 down, the internal balloon 96 still inflated and inside of the planar tissue sample 124 to illustrate how sutures 52 and 54 would traverse from the pledget 78 around the common balloon tube 94 and out on the opposite side of the planar tissue segment 124 now without a zone of tissue compression over a guide wire 122 . The pledget 78 has been lifted away from the planar tissue sample 124 to illustrate how the suture 52 and 54 would traverse from the pledget 78 around the common balloon tube 94 and out on the opposite side.
FIG. 15G now completes the removal of the distal end that was shown in FIG. 15F . Four segments of sutures 52 and 54 are placed now in configuration around the guide wire and the balloon. Not shown here is the therapeutic intervention step to provide cannula or instrument access between the placed horizontal mattress sutures as would be needed in a therapeutic procedure. In a heart apical access procedure, for example, a cannula must be placed over the guide wire into the heart. The internal balloon 96 would be deflated and the common balloon tube 94 would be removed leaving the guide wire 122 still in place in the heart. To ensure hemostasis, tension can be placed on the sutures exiting the tissue to temporarily tighten the mattress suture configuration. A dilator or balloon assembly could be passed over the indwelling guide wire to expand the hole between the mattress sutures to enable cannula placement access for a therapeutic intervention.
FIG. 15H now shows the tightened closure of the horizontal mattress sutures provided in the previous steps. Surgical hand tied or mechanical suture knots 132 can be placed to complete the closure of each horizontal mattress suture. The curved line 1248 at the wound closure site between the pledgets represents the subsequently closed dilated access site that has now been secured between the two horizontal mattress sutures.
FIG. 16A illustrates the thorax 140 of an elderly man. The rib structure is highlighted to reveal the location of the space between the ribs and the underlying heart 152 . The front or anterior surface of the heart's apex projects towards the patient's left lateral chest wall, below the nipple 146 , where, for example, access to the apex of the heart is enabled through the left lateral approach. The interspaces 144 below the 5 th and 6 th ribs 142 provide a more direct access route. Access to the ascending aorta can be through a right upper lateral approach.
FIG. 16B illustrates cardiac anatomy in the thorax 140 without ribs to obscure viewing the underlying structures. The apex 152 A of the left ventricle of the heart 152 lies in the left lateral direction. The anterior ascending aorta 154 , a potential access site for a cardio-pulmonary bypass cannulation, is shown central in the mid chest.
FIG. 17A shows a guide wire 122 placed in the apex 152 A of the left ventricle. The region typically is somewhat devoid of fat and is often called the left ventricular “bald spot.” Placing a guide wire through the heart into the chamber enables the subsequent placement of an access tube into the chamber for minimally invasive heart interventions. In FIG. 17B , the device end 32 shown placed over the guide wire, but prior to external balloon expansion on the common balloon tube 94 , is oriented so the elongated shaft tube 34 would pass through the left lateral chest wall. FIG. 17C shows the completed wound closure site at the end of the transapical procedure. The initial pledget 78 along with the inner suture pledget 126 and outer suture pledget 128 surround the closed access site.
FIGS. 18A-18C are similar to FIGS. 17A-17C described in the previous series. FIG. 18A , however, shows a guide wire now placed in the anterior surface of the anterior ascending aorta 154 . This tubular structure, the body's largest artery, is a frequent place for cannulation for procedures requiring cardio-pulmonary bypass. With the distal end 32 of the device as shown in position over the guide wire 122 in FIG. 18B , the elongated shaft tube 34 of this instrument would pass through the right lateral chest wall. The common balloon tube 94 is again shown in place with its external balloon not expanded. The final aortic wound site closure secured with pledgets 78 , 126 and 128 and horizontal mattress sutures 52 and 54 is shown in FIG. 18C .
While the invention has been described in connection with a number of presently preferred embodiments thereof, those skilled in the art will recognize that many modifications and changes may be made therein without departing from the true spirit and scope of the invention which accordingly is intended to be defined solely by the appended claims.
|
A device for placing sutures through thick and/or moving tissue such as the wall of a beating heart. The device includes a tissue welting tip having a trough for forming a welt in a tissue section, an alignment guide having an opening receiving a guide wire and pivotally mounted in the distal end adjacent to the trough, and an elongated sleeve slidably engagable with the guide wire. The device also includes one or more expandable tissue engaging member(s) on the sleeve expandable from a collapsed configuration having a diameter small enough to pass through the opening in the tip to an expanded configuration having a diameter large enough to engage a tissue section and urge it into the trough to form a welt in the tissue section and a retractable needle extendable through at least two portions of a tissue section while the tissue section is engaged with the trough.
| 0
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to an apparatus and system for applying limited torque to a plug. In one aspect, the invention relates to an apparatus that can be secured to a new or used plug to limit the torque that can be applied in a closing direction to the plug when the plug is used to seal a container.
[0003] 2. Description of the Related Art.
[0004] A typical sealing assembly for a container comprises a plug a tab used to rotate the plug, a gasket associated with the plug, and a flange secured within a container. When a torque-providing device (e.g., wrench, torque wrench, etc.) applies torque (i.e., a rotational force) to the tab in a closing direction, the plug rotates in the closing direction such that the plug is threadably received within the flange. As rotation in the closing direction continues, the gasket is compressed between the plug and the flange. Compression of the gasket between the plug and the flange is expected to form a liquid-impermeable seal, thereby sealing the container and preventing the container from leaking.
[0005] Unfortunately, if an inappropriate amount of torque is administered to the plug, the liquid-impermeable seal will not be formed and the container can leak. For example, if too much torque is applied to the plug, the gasket can be too forcefully compressed, potentially damaging the gasket. On the other hand, if too little torque is applied to the plug, the gasket will not be compressed forcefully enough and the liquid-impermeable seal cannot be achieved. In either case, leaking of the container can result. To ensure the proper application of torque, and consequently prevent the containers from leaking, several solutions have been suggested.
[0006] One solution known to combat over-torquing the plug and/or over-compressing the gasket calls for the use of a torque wrench to provide torque to the tabs. A torque wrench is a device that is calibrated to permit the application of a limited amount of torque to a component such as, for example, the plug. When the limited amount of torque has been delivered, the torque-wrench provides a signal to a torque wrench operator by “slipping”, “giving”, and/or “breaking-away”. The torque wrench can be configured such that the limited torque that is applied to the plug equals the torque necessary to form the liquid-impermeable seal with the compressed gasket. Therefore, by using the torque wrench, the limited torque is theoretically guaranteed to be delivered. However, the torque wrench is often improperly or unskillfully used. All too frequently, the torque wrench operator fails to perceive, or simply ignores, the signal provided by the torque wrench. As such, the torque wrench operator can apply, despite the torque wrench signal, too much torque to the plug. Therefore, the gasket is over-compressed and the sealing assembly can permit the container to leak. Thus, the solution of employing the torque wrench to deliver the limited amount of torque is often ineffectual.
[0007] Another solution to the problem of over-torquing the plug and/or over-compressing the gasket proposes using a torque-limiting device with the plug. As known in the art, such torque-limiting devices typically contain an independent, helical compression spring. For example, in U.S. Pat. No. 4,809,869 to Cosgrove, et. al., pawls, biased by a helical compression spring, engage with ratchet teeth as torque is applied. When the torque becomes excessive, the pawls and ratchet teeth disengage. Also, in U.S. Pat. No. 3,715,075 to Blau, et. al., coupling members, biased by a helical compression spring, engage with groove-like recesses as torque is applied. Again, when the torque becomes excessive, the coupling members and the groove-like recesses disengage. While the torque-limiting apparatus of both Cosgrove and Blau may be useful for some applications, each apparatus critically relies on the independent, helical compression springs to limit the amount of torque. Since each helical compression spring is an integral component within the torque-limiting device/plug combination, it would be difficult, if not impossible, to efficiently fit, retro-fit, and/or adapt the torque-limiting devices disclosed in Cosgrove and Blau to a used, existing, recycled, or previously manufactured plug. Thus, such torque-limiting devices fail to provide the most practical and cost-efficient solution to the problem of over-tightening the plug and/or over-compressing the gasket which can result in container leakage.
[0008] Another proposed solution to the problem of over-torquing the plug and/or over-compressing the gasket involves a more indirect remedy. This solution uses a sealing cap (i.e., a safety cap) in combination with the typical sealing assembly. After the plug has been rotated to compress the gasket between the plug and the flange, the sealing cap is crimped onto, and over, the flange and/or the sealing assembly. Thus, the sealing cap can protectively cover the plug and the gasket. This indirectly prevents the container from leaking even if the gasket fails. While the use of the sealing cap may prevent the container from leaking, the sealing cap neglects the underlying problem (i.e., a damaged or ineffectual gasket). Further, if the plug is to be subsequently removed from the container, reused, and/or recycled, the sealing cap must be damaged to access the plug. A new sealing cap can be required each time the container is to be sealed and/or resealed. As such, maintaining container integrity can become expensive. Therefore, sealing caps provide a less durable and/or less comprehensive solution to the fundamental problem of over-torquing the plug and/or over-compressing the gasket.
[0009] Thus, an apparatus and system that can limit torque applied to a plug by a torque-producing device, permit a gasket to be compressed between the plug and a flange in a container until a liquid-impermeable seal is formed, prevent damage to the gasket, and seal the container, would be highly desirable. Likewise, the apparatus would be constructed of few components and be utilized with used and/or existing plugs.
SUMMARY OF THE INVENTION
[0010] In one aspect, the invention provides an apparatus for limiting torque applied by a torque-providing device. The apparatus can comprise a torque ring rotatably seatable upon a plug and a torque collar securable to the plug and holding the torque ring rotatably captive. The torque ring includes a torque ring aperture that engages the torque-providing device and an axially-protruding resilient finger that provides a resisting force. The torque collar has a torque collar aperture that receives the torque-providing device and a finger aperture that receives and engages the axially-protruding resilient finger. When torque is applied to the torque ring by the torque-providing device in a closing direction, the axially-protruding resilient finger engages the finger aperture to transfer torque from the torque ring to the torque collar. This permits the torque collar to rotate the plug in the closing direction until torque overcomes the resisting force of the axially-protruding resilient finger. When this occurs, the axially-protruding resilient finger disengages from the finger aperture. As a result, the torque ring continues to rotate in the closing direction independent of the torque collar and the plug.
[0011] Disengagement of the axially-protruding resilient finger from the finger aperture can occur when the axially-protruding resilient finger is biased toward the plug, biased away from the torque collar, flattened by the torque collar, forced axially downwardly, radially urged downwardly, and/or bent flush with the torque ring. Therefore, disengagement can cause the axially-protruding resilient finger to temporarily deform such that the finger is not axially-protruding from the torque ring. Also, disengagement can ensure that a gasket, used in conjunction with the plug, is not damaged and a container is sealed. Further, the plug can be removed from being sealably inserted within the container without damage occurring to the plug.
[0012] The resisting force can be determined by friction generated between the axially-protruding resilient finger and the torque collar or by upward protrusion of the axially-protruding resilient finger and friction generated between the axially-protruding resilient finger and the torque collar. Because the resisting force is mechanically determined, the apparatus can eliminate human error by automatically disengaging when the torque applied to the torque ring overcomes the resisting force.
[0013] In one embodiment, the apparatus can be employed with used plugs. In other words, the apparatus can be retro-fitted upon the used plugs. In another embodiment, torque can be applied to the torque ring by the torque-providing device in an opening direction. When this occurs, the to axially-protruding resilient finger engages the finger aperture such that torque is transferred to the torque collar and causes the plug to rotate in the opening direction until the torque is no longer applied by the torque-providing device.
[0014] The axially-protruding resilient finger can include a front surface and a friction surface, the friction surface providing a resisting force. Also, the torque collar can define a sliding surface while the finger aperture can define a camming surface.
[0015] In another aspect, the invention comprises an assembly for limiting torque applied by a torque-providing device. The assembly can include a plug having a periphery, a gasket disposed upon the plug proximate the periphery, and an apparatus secured to the plug. The apparatus can comprise a torque ring and a torque collar. The torque ring, rotatably seatable upon the plug, can include a torque ring aperture that engages the torque-providing device and an axially-protruding resilient finger that provides a resisting force. The torque collar, securable to the plug and holding the torque ring rotatably captive, can include a torque collar aperture that receives the torque-providing device and a finger aperture that receives and engages the axially-protruding resilient finger.
[0016] When torque is applied to the torque ring by the torque-providing device in an opening direction, the axially-protruding resilient finger engages the finger aperture to transfer the torque from the torque ring to the torque collar. This permits the torque collar to rotate the plug in the opening direction until the torque is no longer applied by the torque-providing device.
[0017] Also, when torque is applied to the torque ring by the torque-providing device in a closing direction, the axially-protruding resilient finger engages the finger aperture to transfer the torque from the torque ring to the torque collar. This permits the torque collar to rotate the plug in the closing direction and compress the gasket until the torque overcomes the resisting force of the axially-protruding resilient finger. When torque overcomes the resisting force, the axially-protruding resilient finger disengages from the finger aperture. This results in the torque ring continuing to rotate in the closing direction independent of the torque collar and the plug such that the torque applied to the plug in the closing direction is limited and the compressed gasket is not damaged. Thus, containers using the assembly can be sealed and prevented from leaking.
[0018] In another aspect, the invention comprises a system for sealing. The system can include a plug having a periphery, a gasket disposed upon the plug proximate the periphery, a container, and a torque-limiting apparatus. The container can include a flange that threadably receives the plug and the gasket. Thus, the flange and the plug can compress the gasket thereby sealing the container.
[0019] The container in the system can be a 55-gallon metal drum and the flanges can be two-inch flanges and/or three-quarters inch flanges. The system can further comprise a cap seal that provides protection from leaks. The cap seal is typically secured to the plug after the plug has been secured in the flange within the container.
[0020] In another aspect, the invention comprises a method of limiting torque applied by a torque-providing device. The method comprises providing a plug having a torque-limiting apparatus which includes a torque ring and a torque collar. The torque ring, rotatably seatable upon the plug, can have a torque ring aperture that engages the torque-providing device and an axially-protruding resilient finger that provides a resisting force. The torque collar, securable to the plug and holding the torque ring rotatably captive, can have a torque collar aperture that receives the torque-providing device and a finger aperture that receives and engages the axially-protruding resilient finger.
[0021] Next, torque is applied, in a closing direction, to the torque ring using the torque-providing device. This results in the axially-protruding resilient finger and the finger aperture engaging to translate torque to the plug. The plug is thereby rotated, in the closing direction, until torque overcomes a resisting force of the axially-protruding resilient finger. When the resisting force is overcome, the axially-protruding resilient finger and the finger aperture disengage such that the torque ring rotates relative to the torque collar. Thus, the amount of torque that can be applied to the plug is limited.
[0022] The method can further comprise inserting the plug into a flange disposed within a lid of a container. The method can also include compressing a gasket on the plug against the flange when the plug is rotated in the closing direction to seal the container. Further, the method can insure that damage to gaskets is inhibited and/or prohibited by disengaging the torque ring and the torque collar when the resisting force is overcome.
[0023] Additionally, the method can comprises applying torque, in an opening direction, to the torque ring using the torque-providing device. Opening-direction torque can cause the axially-protruding resilient finger and the finger aperture to engage and translate torque to the plug. As such, the plug can rotate in the opening direction until the torque-providing device ceases to apply the torque.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Embodiments of the invention are disclosed with reference to the accompanying drawings and are for illustrative purposes only. The invention is not limited in its application to the details of construction, or the arrangement of the components, illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in other various ways. Like reference numerals are used to indicate like components.
[0025] [0025]FIG. 1 illustrates an exploded, perspective view of a prior art sealing assembly for use with a container.
[0026] [0026]FIG. 2 illustrates an elevational, cross-sectional view, taken along line 2 - 2 of FIG. 1, showing a plug with tabs.
[0027] [0027]FIG. 3 illustrates a top, plan view of the plug of FIG. 2.
[0028] [0028]FIG. 4 illustrates an elevational, cross-sectional view of the plug of FIG. 2 employing an embodiment of a torque-limiting apparatus according to the invention.
[0029] [0029]FIG. 5 illustrates a top, plan view of the plug of FIG. 4.
[0030] [0030]FIG. 6 illustrates an elevational, cross-sectional view of the plug of FIG. 2 employing an embodiment of torque-limiting apparatus according to the invention with the tabs having been removed.
[0031] [0031]FIG. 7 illustrates a top, plan view of the plug of FIG. 6.
[0032] [0032]FIG. 8 illustrates a top, plan view of a torque ring within the torque-limiting apparatus of FIGS. 4 and 6.
[0033] [0033]FIG. 9 illustrates a elevational, cross-sectional view of the torque ring of FIG. 8 taken along line 9 - 9 .
[0034] [0034]FIG. 10 illustrates a top, plan view of a torque collar within the torque-limiting apparatus of FIGS. 4 and 6.
[0035] [0035]FIG. 11 illustrates a elevational, cross-sectional view of the torque collar of FIG. 10 taken along line 11 - 11 .
[0036] [0036]FIG. 12 illustrates a side, elevational view of a portion of the torque-limiting apparatus from FIG. 6 which highlights engagement of an axially-protruding resilient finger and a finger aperture when torque is applied in a closing direction.
[0037] [0037]FIG. 13 illustrates a side, elevational view of the portion of the torque-limiting apparatus from FIG. 6 which highlights disengagement of the axially-protruding resilient finger and the finger aperture when a resisting force is overcome by the applied torque.
[0038] [0038]FIG. 14 illustrates a side, elevational view of the portion of the torque-limiting apparatus from FIG. 6 which highlights engagement of the axially-protruding resilient finger and the finger aperture when torque in applied an opening direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Referring to FIG. 1, an exploded view of conventional sealing assembly 2 , as known in the art, is illustrated in association with lid 4 of container 6 . The typical sealing assembly 2 comprises flange 8 , gasket 10 , and plug 12 .
[0040] As known in the art, flange 8 (i.e., a bunghole) typically comprises a circular, threaded member that is crimped or otherwise secured within lid 4 of container 6 . One or more flanges 8 can be employed on lid 4 , or elsewhere upon container 6 , to permit the container to receive and discharge fluids. Often, container 6 will comprise a 55-gallon metal drum containing two differently-sized flanges 8 , namely a 2-inch flange and a ¾-inch flange. The 2-inch flange can permit the ingress of one fluid (e.g., water, fuel oil, liquid chemicals) while the 4-inch flange can concurrently permit the egress of another fluid (e.g., air, other gases). After container 6 is filled, flanges 8 are generally sealed to prepare the container for shipping, transportation, and/or storage. To seal the container 6 , it is known in the art to employ sealing assembly 2 , as illustrated in FIG. 1, or another like sealing assembly.
[0041] In FIG. 1, gasket 10 is illustrated in a typical arrangement within sealing assembly 2 . As shown, gasket 10 can be positioned between flange 8 and plug 12 . Usually, gasket 10 is received and seated upon flange 8 , fitted upon plug 12 proximate a plug periphery 14 , or the like. Gasket 10 can be incorporated within, or as a part of, sealing assembly 2 in various arrangements, such arrangements being known in the art. Gasket 10 can be made of rubber, or a like material, which provides the gasket with the ability to form a liquid-impermeable seal between adjacent components (e.g., plug 12 and flange 8 ), particularly when the gasket is compressed.
[0042] As illustrated in FIGS. 2 and 3, plug 12 can comprise a circular, threaded member configured to be threadably received within flange 8 . When plug 12 is rotated, the plug can be either drawn toward, or away from, flange 8 , depending on the direction of rotation. For example, when plug 12 is rotated in a “closing” direction (e.g., clockwise), the plug is drawn and/or pulled closer to flange 8 . Alternatively, when plug 12 is rotated in an “opening” direction (e.g., counter-clockwise), the plug is urged, biased, and/or pushed away from the flange.
[0043] Referring back to FIG. 1, if plug 12 receives torque (i.e., a rotational force) in the closing direction, the plug is drawn towards the flange and gasket 10 is compressed between the plug and the flange. As such, gasket 10 can form a seal that inhibits and/or prevents fluid penetration. Similarly, if torque is applied to plug 12 in the opening direction, gasket 10 can be decompressed and thereby release, discharge, and/or terminate the liquid-impermeable seal that inhibits and/or prevents fluid penetration. If rotation in the opening direction continues long enough, plug 12 can be removed, ejected, and/or expelled from flange 8 altogether.
[0044] In order to accept torque, plug 12 can be equipped with tabs 16 (i.e., lugs, drive lugs, and the like) as illustrated in FIGS. 1 - 3 . Tabs 16 can comprise one or more pieces of plastic, metal, and/or other like materials secured to, for example, top surface 18 of plug 12 . Securement of tabs 16 to plug 12 can be accomplished with spot welds (not shown) or other methods known in the art.
[0045] Tabs 16 on plug 12 can be configured to receive and/or engage a multitude of torque-providing devices, such as a wrench, a torque wrench, and/or similar tools (not shown). Engagement of the torque-providing device and tabs 16 facilitates translation and/or transfer of torque from the torque-producing device to plug 12 . Thus, the torque-producing device can rotate plug 12 in either the opening or the closing direction. Unfortunately, this system of providing torque, and therefore rotation, to plug 12 is fraught with perils. Therefore, gasket 10 can be over-compressed, under-compressed, damaged, and the like. Thus, sealing assembly 2 , which relies on the liquid-impermeable seal being formed by gasket 10 , can fail. Failure of sealing assembly 2 and/or gasket 10 allows fluids to escape from container 6 . In other words, sealing assembly 2 and/or gasket 10 can be ineffectual and container 6 can leak.
[0046] To prevent, inhibit, and/or eliminate over-compressed, under-compressed, damaged, and otherwise ineffectual gaskets and sealing assemblies, a torque-limiting apparatus 20 according to the invention is illustrated in FIGS. 4 - 7 . In FIGS. 4 and 5, an embodiment of torque-limiting apparatus 20 is secured to a conventional plug, such as plug 12 (FIG. 1), while tabs 16 are still secured to and/or disposed on the plug. However, in a preferred embodiment as illustrated in FIGS. 6 and 7, torque-limiting apparatus 20 can be secured to the conventional plug 12 where tabs 16 have been removed and/or otherwise eliminated. In each of these embodiments, torque-limiting apparatus 20 is intended to replace and/or be used in lieu of tabs 16 to provide torque and/or a rotational force to plug 12 .
[0047] In addition to torque-limiting apparatus 20 being adaptable to conventional plugs 12 and/or capable of being retro-fit (i.e., installed after manufacture) to the conventional plugs as illustrated in FIGS. 4 and 6, the torque-limiting apparatus can also be installed on a newly manufactured plug (not shown). Whether employed on a new or used plug, torque-limiting apparatus 20 can function and/or perform effectively. Thus, torque-limiting apparatus 20 is universally adaptable and/or securable to newly manufactured plugs, previously manufactured plugs, plugs with tabs 16 , plugs without the tabs, and the like. In preferred embodiments, torque-limiting apparatus 20 is employed within conventional sealing assembly 2 when plug 12 is a used plug, an existing plug, a re-used plug, an old plug, and/or a recycled plug.
[0048] As shown in FIGS. 4 - 7 , torque-limiting apparatus 20 comprises torque ring 22 and torque collar 24 . Torque ring 22 and torque collar 24 can each be manufactured from a variety of materials such as metal, metal alloys, plastic, and the like. In preferred embodiments, torque ring 22 and/or torque collar 24 are constructed of stainless steel.
[0049] In a preferred embodiment, as illustrated in detail in FIGS. 8 and 9, torque ring 22 comprises a circular, metal member having flange portion 26 and raised, central portion 28 . Central portion 28 , when viewed from above (FIG. 8), can be round, square, hexagonal, octagonal, or similarly shaped. Further, central portion 28 can include torque ring aperture 30 which is designed and configured to receive the torque-providing device (not shown). Torque ring aperture 30 , when viewed from above (FIG. 8), can be also be round, square, hexagonal, octagonal, or similarly shaped. Torque ring aperture 30 is capable of complimenting, through engagement, the host of possible torque-providing devices available. It is also contemplated that torque ring aperture 30 can be adjustable to provide wide-ranging acceptance of available torque-providing devices.
[0050] Still referring to FIGS. 8 and 9, flange portion 26 can include one or more axially-protruding, resilient fingers 32 (i.e., coupling members, ratchet teeth, extensions, protrusions, and the like). Each finger 32 can be formed by making incisions within torque ring 22 along a periphery 34 of each finger and thereafter vertically elevating, axially raising, and/or upwardly bending the finger at vertex end 36 . As used herein, “upward” and “upwardly” are defined as being toward plug opening 38 and/or away from top surface 18 when torque-limiting apparatus 20 is secured to plug 12 as illustrated in FIGS. 4 and 6. Similarly, as used herein, “downward” and “downwardly” are defined as being away from plug opening 38 and/or towards top surface 18 when torque-limiting apparatus 20 is secured to plug 12 as illustrated in FIGS. 4 and 6.
[0051] When finger 32 is bent upwardly and/or protrudes from torque ring 22 , salient end 40 of the finger is extracted from torque ring 22 and becomes exposed as illustrated in FIG. 9. Exposure of finger 32 from within torque ring 22 creates and/or defines a front surface 42 and a friction surface 44 .
[0052] In a preferred embodiment, after upwardly bending finger 32 , the finger maintains the upwardly-bent position. However, despite being upwardly disposed, finger 32 remains flexible and, furthermore, resilient. As such, finger 32 can be biased downwardly upon the application of a downward and/or radial force, yet return to the upwardly-bent configuration when the downward and/or radial force is removed. For example, upon the application of sufficient downward and/or radial force, finger 32 can flexibly retreat back to the original, “un-bent” or flush position within torque ring 22 . Thereafter, upon removal of the downward and/or radial force, finger 32 is capable of “springing back” to the upwardly-bent position as illustrated in FIG. 9.
[0053] In an exemplary embodiment, torque ring 22 , and/or particularly finger 32 , can be hardened, flexibly stiffened, made resilient and/or otherwise treated to ensure that the finger possess a resilient, “spring-like” property which will encourage the finger to remain upwardly (i.e., axially) biased. Because finger 32 is resilient, the finger is capable of withstanding shock without permanent deformation and will tend to recover from, or adjust to, misfortune and/or change. Therefore, finger 32 can have the ability to recover size and/or shape after deformation caused by stress, and especially compressive stress. Such methods of treating metal and/or other to substances to provide resiliency, for example through chemical and/or thermal exposure, are well known and contemplated.
[0054] Torque collar 24 presents a circular, metal member having flange portion 46 , raised, central portion 48 , and lower surface 50 . Disposed within central portion 48 are one or more finger apertures 52 and torque collar aperture 54 . Each finger aperture 52 , which extends entirely through torque collar 24 , includes and defines camming surface 56 as illustrated in FIGS. 4, 6, and 10 . Torque collar aperture 54 is designed and configured to receive central portion 28 of torque ring 22 . As such, torque collar aperture 54 can be round, square, hexagonal, octagonal, or similarly shaped to correspond to the shape of central portion 28 .
[0055] Finger apertures 52 are designed and configured to receive and engage fingers 32 . As such, in preferred embodiments, the number of finger apertures 48 within torque collar 24 agrees with and/or corresponds to the number of fingers 32 on torque ring 22 . For example, as illustrated in FIGS. 8 and 10, four fingers 32 and four finger apertures 52 are shown. However, it is contemplated that one or more fingers 32 , as well as one or more finger apertures 48 , can be used. Furthermore, there is no requirement that the number of fingers 32 correspond to the number of finger apertures 48 although such an arrangement can be preferred.
[0056] Referring back to FIGS. 4 and 6, in a preferred embodiment torque-limiting apparatus 20 is assembled and/or constructed when torque collar 24 is disposed upon torque ring 22 . As shown, central portion 28 of torque ring 22 is received by torque collar aperture 54 in torque collar 24 . In this mating arrangement, central portion 28 is placed within, and upwardly protrudes from, collar aperture 54 . At the same time, any fingers 32 on torque ring 22 are received by finger apertures 52 in torque collar 24 . Thus, fingers 32 are placed within, and upwardly protrude into, corresponding finger apertures 52 . As assembled, torque ring 22 would be free to rotate underneath torque collar 24 if not for the impediment produced by the engagement of fingers 32 and finger apertures 52 .
[0057] After torque collar 24 has been mounted on torque ring 22 , torque-limiting apparatus 20 can be secured to plug 12 (or a new plug). As illustrated in FIGS. 5 and 7, securement can be performed by forming one or welds 58 between torque collar 24 and plug 12 . In preferred embodiments, welds 58 are formed at, or upon, flange portion 46 of torque collar 24 . As such, torque collar 24 is directly connected to plug 12 . Conversely, torque ring 22 is only indirectly connected to plug 12 by the interaction of torque collar 24 with torque ring 22 and/or fingers 32 with finger apertures 52 .
[0058] In operation, plug 12 can employ torque-limiting apparatus 20 as shown in FIGS. 4 and 6 and can be disposed within, for example, sealing assembly 2 (FIG. 1). In such an arrangement, plug 12 can begin to be threadably inserted into flange 8 . Thereafter, the torque-providing device (not shown) can be inserted into and/or received by torque ring aperture 30 . If torque is supplied in the closing direction by the torque-providing device, torque ring 22 will correspondingly attempt to, be encouraged to, and/or begin to rotate in the closing direction. As shown in FIG. 12 , when torque ring 22 begins to rotate in the closing direction, friction surface 44 , provided by finger 32 , engages torque collar 24 , particularly at lower surface 54 . Such engagement can permit the finger 32 to generate and/or produce a resisting force that, for the most part, opposes the torque applied in the closing direction.
[0059] In one embodiment, the resisting force can be comprised of friction when, for example, friction surface of finger 32 and lower surface 54 of finger aperture 52 (i.e., torque ring 22 and torque collar 24 ) abrade against each other. In another embodiment, the resisting force can be comprised of shear resistance generated by the upwardly (i.e., axially) protruding finger abutting the torque collar. In yet another embodiment, the resisting force can be comprised of both friction and shear resistance by combining both of the above embodiments.
[0060] To adjust the resisting force, the resiliency of finger 32 can be increased or decreased, friction surface 44 of finger 32 can be altered, lower surface 54 of torque collar 24 can be altered, additional fingers 32 can be added to torque ring 22 , and the like. Such actions will either increase or decrease the magnitude of the resisting force. By varying these properties, the engagement of finger 32 and finger aperture 52 can be consequently prolonged or diminished.
[0061] Since the resisting force holds finger 32 and finger aperture 52 (i.e., torque ring 22 and torque collar 24 ) in engagement, the torque applied to the torque ring in the closing direction is translated from the torque ring to the torque collar. In turn, since torque collar 24 is secured to plug 12 , the torque is thereafter translated from the torque collar to the plug 12 . As such, plug 12 can be rotated in the closing direction by application of torque to torque ring 22 .
[0062] If plug 12 , using torque-limiting apparatus 20 , is part of sealing assembly 2 (FIG. 1), rotation of the plug in the closing direction can cause the plug to be drawn toward flange 8 . As the rotation continues, plug 12 can compress gasket 10 against flange 8 . Thus, gasket 10 is capable of forming a liquid-impermeable seal. However, as noted above, if gasket 10 is too forcefully compressed, or insufficiently compressed, container 6 can leak. Therefore, torque-limiting apparatus 20 is designed to provide an “appropriate” amount of torque by disengaging when the appropriate amount of torque has been administered and/or achieved. When torque-limiting apparatus disengages, no further torque is supplied to plug 12 and further compression of gasket 10 ceases.
[0063] The “appropriate” torque can be defined as that amount of torque that causes disengagement of finger 32 and finger aperture 52 , that amount of torque that inhibits and/or prevents damage to gasket 10 , that amount of torque that permits gasket 10 to form the liquid-impermeable seal between plug 12 and flange 8 , or that amount of torque that inhibits and/or prevents container 6 from leaking.
[0064] For torque-limiting apparatus to disengage, the torque applied in the closing direction overcomes and/or exceeds the resisting force. When the resisting force succumbs to the superiority of the torque, finger 32 is temporarily biased downwardly and/or radially by finger aperture 52 and/or lower surface 54 as illustrated in FIG. 13. In other words, finger 32 can be biased toward plug 12 , biased away from torque collar 24 , flattened by the torque collar, and/or bent flush with torque ring 22 . The downward and/or radial pressure causes finger 32 to be displaced from the upwardly-bent, protruding position. Therefore, finger 32 can be persuaded to retreat within torque ring 22 until friction surface 44 becomes flush with torque ring 22 as depicted in FIG. 13.
[0065] When finger 32 achieves the position illustrated in FIG. 13, torque ring 22 no longer drives torque collar 24 and plug 12 . With plug 12 idled, compression of gasket 10 halts. Therefore, during disengagement, torque ring 22 is capable of rotating, at least temporarily, underneath torque collar 24 . Since torque-limiting apparatus 20 discontinues providing torque to plug 12 upon disengaging at the “appropriate” torque, over-compressing, under-compressing, and/or damaging of gasket 10 is discouraged and/or avoided altogether. Thus, torque-limiting apparatus 20 ensures, by disengaging at the “appropriate” torque, that the liquid-impermeable seal will be formed and container 6 will not leak.
[0066] Because the appropriate amount of torque and the resisting force directly correspond to each other, the resisting force can adjusted to correspondingly adjust the appropriate torque applied to plug 12 . When the appropriate amount of torque is adjusted, the point at which torque-limiting apparatus 20 disengages can be altered and/or changed. Thus, the amount of torque applied to plug 12 , which compresses gasket 10 , can be modified and/or varied as desired.
[0067] Additionally, the amount of compression experienced by gasket 10 can be adapted and/or adjusted to suit various container sealing conditions (e.g., where the gasket is composed of variable materials, where the gasket is compressed at different temperatures, where the fluid being contained is pressurized, etc.).
[0068] Notably, the torque-limiting benefit bestowed upon plug 12 by torque-limiting apparatus 20 is provided without the need or requirement for an independent, helical compression spring or other distinct, independent “spring-like” component. The axially-protruding, resilient fingers 32 are integrated and/or incorporated directly within torque ring 22 .
[0069] After disengagement occurs as shown in FIG. 13, if torque ring 22 rotates beneath torque collar 24 far enough, finger 32 on the torque ring will once more encounter finger aperture 52 (or another finger aperture) and can become engaged with the finger aperture as shown in FIG. 12. When this “re-engagement” takes place, finger 32 springs upwardly within finger aperture 52 and resiliently resumes the upwardly-bent position.
[0070] In addition to preventing over-compression of gasket 10 , torque-limiting apparatus 20 discourages under-compressing the gasket as well. Until the appropriate amount of torque has been administered to torque ring 22 , and resultantly torque collar 24 and plug 12 , the torque ring and the torque collar remain engaged due to the resisting force. While engagement continues, torque and rotation in the closing direction persist, thereby causing gasket 10 to be increasingly compressed. Thus, torque-limiting apparatus can simultaneously and/or concurrently cope with both the problem of over-compression and under-compression of gasket 10 .
[0071] As illustrated in FIG. 14, in addition to rotating plug 12 in the closing direction, torque-limiting apparatus 20 can also rotate the plug in an opening direction. In fact, rotation in the opening direction and rotation in the closing direction are generally performed by the same pair of components, namely finger 32 and finger aperture 52 . However, engagement of finger 32 with finger aperture 52 during rotation in an opening direction is unique.
[0072] The torque-providing device (not shown) can be inserted into and/or received by torque ring aperture 30 . If torque is supplied in the opening direction by the torque-providing device, torque ring 22 will correspondingly attempt to, be encouraged to, and/or begin to rotate in the opening direction. As shown in FIG. 14, when torque ring 22 begins to rotate in the opening direction, front surface 42 , provided by finger 32 , engages torque collar 24 , particularly at camming surface 56 . The engagement of front surface 42 and camming surface 56 causes the torque applied in the opening direction to be translated from torque ring 22 to torque collar 24 . Since torque collar 24 is secured to plug 12 , the torque experienced by the torque collar is supplied to plug 12 . Thus, engagement of finger 32 with finger aperture 42 , and particularly front surface 42 and camming surface 56 , allows torque to be indirectly distributed from torque ring 22 to plug 12 . As such, plug 12 can be rotated in the opening direction and biased and/or pushed away from flange 8 , thereby decompressing gasket 10 .
[0073] Plug 12 can be threadably loosened, removed from container 6 , and thereafter reused. Thus, plug 12 can beneficially be inserted and removed from container 6 as many times as desired. Such reuse does not damage plug 12 , container 6 , or any other component associated with sealing assembly 2 .
[0074] Also, even though a cap seal (i.e., a safety seal) may not be necessary to prevent container 6 from leaking, torque-limiting apparatus 20 , as secured to plug 12 , does not interfere with the later attachment of such a cap seal. This can be of consequence if municipal, county, state, and/or government regulations, or the like, require and/or encourage the use of cap seals to augment or further guarantee protection from leaks.
[0075] Despite any methods being outlined in a step-by-step sequence, the completion of acts or steps in a particular chronological order is not mandatory. Further, elimination, modification, rearrangement, combination, reordering, or the like, of acts or steps is contemplated and considered within the scope of the description and claims.
[0076] While the present invention has been described in terms of the preferred embodiment, it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
|
Apparatus for limiting torque comprising a torque ring rotatably seatable upon a plug and a torque collar securable to the plug and holding the torque ring rotatably captive. Torque ring includes a torque ring aperture and an axially-protruding resilient finger. Torque collar includes a torque collar aperture and a finger aperture. Closing-direction torque applied to torque ring is transferred to torque collar and then to plug to rotate plug in the closing direction. Rotation continues until torque overcomes a resisting force wherein finger disengages from finger aperture, torque ring rotates relative to torque collar, and the amount of closing-direction torque that can be applied is limited. Opening-direction torque and rotation of plug is without limit. Over-compressing or under-compressing of gaskets can be eliminated and containers can be inhibited and/or prevented from leaking. The apparatus is compatible with both new and used plugs.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of German application No. 10 2006 001 884.2 filed Jan. 13, 2006, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a hollow space wherein the hollow space has an access point and a target point for a surgical instrument which can be introduced at least partially into the hollow space, and wherein a three dimensional image data set of a section of the hollow space having the access point and/or the target point is determined and spatially displayed.
BACKGROUND OF THE INVENTION
[0003] Hollow spaces in an object under investigation, for example vascular pathologies, in particular intracranial vascular pathologies, are frequently dealt with by means of a catheter introduced into the femoral artery and fed via the blood vessels to the site of the lesion. As a rule the positioning and/or location of the catheter is performed using continuously pulsed X-ray transillumination to capture two dimensional projection data sets, together with the application of contrast medium. In so doing it often proves difficult for the neuroradiologist to reconcile the captured two dimensional projection data sets with the complex, three dimensional shape of the actual vascular tree.
[0004] Three dimensional images of a hollow space or hollow organ can nowadays be generated by various imaging modalities, such as magnetic resonance, computed tomography and 3D C-arm methods. Angiographic procedures are a suitable way of displaying blood vessels. In the case of 3D angiography, performed for example by means of a C-arm, a spatial display of the vascular tree is reconstructed and visualized from a plurality of preoperative or intraoperative two dimensional X-ray projection images captured from different angles. The recording techniques mentioned above provide the neuroradiologist with a spatial display of the hollow space system, for instance an intracranial vascular tree.
[0005] The gastrointestinal tract, trachea system, lymphatic system, bladder, ureter, blood vessel system etc. can be thought of as further examples of hollow spaces in the bodies of humans and animals that also include a hollow organ. There may also be other types of objects of investigation containing a hollow space or system of hollow spaces. The example of the surgical instrument designed as a catheter also needs to be taken into account.
[0006] Patent application DE 199 19 907 A1 discloses a method and a device for catheter navigation in three dimensional vascular tree recording, wherein the catheter position is determined by means of a miniaturized position detection system built into its tip and displayed in the 3-D view of the vascular tree recorded preoperatively and reconstructed in a navigation computer. The disadvantage of this method is that it does not provide the medical staff with a rapid means of guidance within the vascular tree recording.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to provide a method of the type described in the introduction, providing the medical staff with improved guidance in the object being examined.
[0008] This object is achieved by an inventive method of the type described in the introduction, in that the access point and/or the target point is highlighted in the spatial display of the hollow space section. Highlighting of the access point and/or target point in the spatial display of the hollow space section is carried out as a rule by the medical staff. Not only the target point to be reached by the surgical instrument but also in appropriate cases the access point are highlighted in the spatial display. Highlighting the access point and target point proves to be advantageous when the medical staff need to be sure of their direction in a hollow space taking the form of a blood vessel system with a high degree of branching—such as a coronary or intracranial vascular tree. Highlighting makes the course of the blood vessel from the access point to the target point easier to recognize among a high number of branches and further blood vessels. For this it is not necessarily obligatory for a surgical instrument to be introduced into the hollow space section. However the method can be used during a surgical operation and for planning an operation.
[0009] The highlighting of an appropriate point is carried out for example on an input/output unit using for instance a mouse-controlled cursor on a monitor display surface where the spatial display of the hollow space section is visualized. The highlighted target and/or access points are then visualized in the spatial display, possibly by making them colored and flashing.
[0010] Advantageously the spatial display can be freely rotated on the monitor, a zoom function is provided, and intersecting planes through the spatially displayed hollow space section can be selected and viewed. This approach enables far simpler highlighting of the access point and/or target point, which is particularly advantageous in the case of intracranial vascular trees. Alternatively an automated method can be used to search for possible target points and highlight them as necessary in the display, including stenosis, aneurysms, etc.
[0011] In an advantageous embodiment of the invention, points of interest between the access and target points on the hollow space section are shown as highlighted reference points in the spatial display. These points can include narrowing of a blood vessel, bending of a blood vessel or the branching of blood vessels from the blood vessel connecting the access point and the target point. The highlighting of points of interest in the spatial display provides further reference points to assist in the guidance of surgical specialists, delivering valuable and easily recognizable information when an operation is being performed or planned.
[0012] In a further advantageous embodiment of the invention, a planned path for the surgical instrument from the access point to the target point in the hollow space section is highlighted in the spatial display. The planned path for the surgical instrument can be manually selected taking the existing situation into account, for example by the surgical specialists selecting a sufficient number of reference points for a special blood vessel connecting the access point and the target point.
[0013] Alternatively the blood vessel connecting the access point and the target point can be determined in spatial displays with the aid of structure detection software, and then be highlighted to particularly good advantage in the display, likewise with the aid of software.
[0014] The blood vessel to be highlighted can be determined according to defined criteria, such as the shortest path between the access point and the target point, or the path with the largest of the smallest blood vessel diameters, so as to enable a high degree of freedom of navigation, etc. For this purpose equidistant reference points on the blood vessel are established by software to determine the path, adjacent reference points being linked by a polygonal line. The distance between reference points needs to be chosen in such a way that within a tolerance range the polygonal line takes virtually the same course as the blood vessel needing to be highlighted.
[0015] Alternatively, highlighting can be applied manually by the user, by highlighting the blood vessel needing to be highlighted, for instance by means of a pointer on a touchscreen showing the spatial displays, and then displaying it complete with highlighting. Highlighting, in the sense of the improved visibility of an entire blood vessel or point, can be carried out using any means. For example the highlighting can be colored to make it stand out from the rest of the spatial display, or may flash periodically, or parts of the vascular tree may be hidden.
[0016] In a further advantageous embodiment of the invention the position and/or situation of at least one section of the introduced surgical instrument is determined and shown in the spatial display of the hollow space section. The method is used while a surgical operation is being performed. The blood vessel connecting the access and target points, or at least some section thereof, is highlighted in the display.
[0017] In addition, the position and/or situation of the introduced surgical instrument is determined during the surgical operation and shown in the spatial display. Advantageously the highlighted section in the spatial display of the hollow space section shows at least the introduced end of the surgical instrument. This makes it easier to recognize when the instrument is no longer being fed along the planned blood vessel—which as a rule is the highlighted one. This makes it easier to guide the instrument.
[0018] A deviation when guiding the surgical instrument during an operation can thus be more quickly and easily identified. The position and/or situation of the instrument can be shown by, for example, registration marks applied to the object under investigation, or by anatomically significant points.
[0019] In a preferred embodiment of the invention the hollow space section is displayed without the surroundings imposed by the object under investigation. For the purpose of the operation, potentially distracting anatomical background is removed from the spatial display of the hollow space section. This makes the display of the hollow space even clearer. For determining a vascular system or vascular tree displayed in this way, subtraction image methods can be used among other things to determine the spatial display of the hollow space section, or the magnetic resonance angiography method can also be used. By using a spatial display of a hollow space system showing only the hollow space system itself, the highlighting for the appropriate hollow space can be simplified, and if necessary the position and/or situation of the surgical instrument can be superimposed on the spatial display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further advantages of the invention will emerge from an exemplary embodiment that is further explained with the aid of the accompanying drawings, in which
[0021] FIG. 1 shows a device for determining a spatial display of a hollow space section
[0022] FIG. 2 shows a spatial display of a hollow space section in the form of diagrams.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 shows a device for determining the spatial display 1 of a hollow space in the form of a hollow organ 1 ′ in a human body 2 . In the exemplary embodiment, the hollow organ 1 ′ of which a spatial display is to be determined takes the form of an intracranial vascular tree 1 ′. Data concerning the body 2 is captured by means of a recording unit 40 in order to determine a spatial display 1 of the intracranial vascular tree 1 ′. For this purpose the human body 2 is arranged on a couch 50 . The recording unit 40 can be produced in numerous forms, such as a magnetic resonance device or a tomography-enabled C-arm.
[0024] When the recording unit 40 has captured the data, said data is available either as a three dimensional image data set, as in magnetic resonance methods, or is converted by suitable methods, such as back projection in the case of projection data sets recorded with X-rays, into a three dimensional image data set. For this purpose the data is passed to a data processing unit 41 and processed. A spatial display 1 of the measured hollow space section 1 ′ in the object under investigation 2 is determined from the captured data and then displayed on an input/output unit 42 .
[0025] An intracranial catheter 20 is then introduced into the human body 2 in FIG. 1 . The intracranial catheter 20 is introduced through an access point 5 in the human body 2 . In FIG. 1 the intracranial catheter 20 is introduced into the brachial artery in the upper arm and from there into the intracranial vascular tree 1 ′.
[0026] FIG. 2 is explained below in conjunction with the device shown in FIG. 1 , the reference numbers of device components referring to said FIG. 1 . FIG. 2 shows the spatial display 1 of an intracranial vascular tree 1 ′, determined by means of the device described in FIG. 1 . The intracranial vascular tree 1 ′ is composed of a plurality of blood vessels which supply blood to the brain of an object under investigation 2 —in this case a human patient—and are shown in the spatial display 1 as blood vessels 3 . In this particular case the intracranial vascular tree 1 ′ has a blood vessel exhibiting pathological narrowing.
[0027] This pathological narrowing, known as a stenosis, is defined by the medical staff with the aid of the spatial display 1 of the intracranial vascular tree 1 ′ or by automated means with subsequent checking by the medical staff as target point 4 , and has to undergo surgical treatment performed by medical staff using an intracranial catheter 20 .
[0028] As a rule, before the surgical operation on the patient 2 a spatial display 1 of the intracranial vascular tree 1 ′ is determined by for example computed tomography angiography, magnetic resonance angiography or 3D C-arm angiography. The spatial display 1 can if necessary visualize the entire vascular tree 1 ′ from the target point 4 to an access point 5 through which the surgical instrument 20 is introduced into the patient 2 . In the case of intracranial operations a section of the brachial artery may be used as the access point 5 . A section of the femoral artery is frequently used as the access point for heart operations.
[0029] If the entire vascular tree 1 ′ from the access point 5 to the target point 4 is recorded, it is preferably done at a single examination so as to avoid assembling displays of vascular tree subsections taken at relatively widely separated times.
[0030] The access point end of the vascular tree section is not completely shown in FIG. 2 and merely refers to the remote access point 5 for the intracranial catheter 20 on the right upper arm of the human body 2 . In the exemplary embodiment the target point 4 is selected on a touchscreen 42 by the surgical staff with the aid of the spatial display 1 of the vascular tree 1 ′.
[0031] Highlighting is applied by exerting pressure at the appropriate point on the touchscreen 42 . For the purpose of selecting the target point 4 the spatial display 1 can be freely rotated, and there is a facility to zoom in on sections of the spatial display 1 . If the target point 4 is determined by selecting an appropriate section of blood vessel—in this case the narrowing—said target point is clearly highlighted in color in the spatial display 1 . Once the target point 4 is established it is passed to a data processing unit 41 .
[0032] With regard to guiding the instrument 20 from an access point 5 to a target point 4 , a path 6 is selected for the surgical instrument 20 provided a plurality of options exist. The path 6 is established as a rule by surgical staff, for instance by highlighting further reference points for the blood vessel 3 established as the path 6 in the spatial display. Alternatively said blood vessel can also be determined with the aid of software, calculating for instance the shortest connection between the access point 5 and the target point 4 , or the connection with the largest of the smallest diameters so as to avoid damaging the blood vessel. Contrast methods can be used for detecting the blood vessel 3 to be highlighted, or other methods for detecting structures in images may be used.
[0033] Furthermore critical points in the spatial display 1 of the blood vessel 3 connecting the access point 5 and the target point 4 are highlighted and shown in the spatial display 1 as branch points. Not all branch points in the blood vessel 3 connecting the access point 5 and the target point 4 are highlighted, but rather only those where there could be a risk of confusion when threading the intracranial catheter 20 . This is the case for the branch points or reference points 7 to 10 highlighted in FIG. 2 .
[0034] In addition to the reference points 7 to 10 , the entire course of the blood vessel 3 connecting the access point 5 and the target point 4 can be shown in the spatial display 1 with highlighting 30 .
[0035] Advantageously the highlighting 30 is applied using a computer, a starting point for the highlighting 30 being established in the same way as the access point 5 , reference points 7 or 8 or 9 or 10 and target point 4 are established, as a rule manually. In FIG. 2 the starting point for the highlighting 30 is identical to the access point 5 . With the aid of the established target point 4 and the starting point—in this case the access point 5 —as well as the highlighted reference points 7 to 10 , the blood vessel 3 concerned can be determined in the spatial display 1 by means of the data processing unit 41 and can for example be highlighted in color on the input/output unit 42 .
[0036] Alternatively the highlighting 30 for a length of the blood vessel 3 connecting the access point 5 and the target point 4 can be applied manually by the surgical staff on the touchscreen 42 , though as a rule this requires more time. The highlighting 30 for the blood vessel 3 connecting the access point 5 and the target point 4 makes it possible to obtain a very clear overview of the spatial course taken by the path 6 for the surgical instrument 20 , together with an overview of significant or critical points on the course of said blood vessel.
[0037] When the spatial display 1 showing the highlighted blood vessel is used during an operation, the guidance provided to the surgical staff in the object under investigation 2 can be further improved. For this purpose the intracranial catheter 20 is located by means of an image-based method, for example. The position and/or situation of the surgical instrument 20 or the spatial display determined for the surgical instrument is superimposed on the spatial display 1 of the intracranial vascular tree 1 ′ with highlighted path 6 . To ensure the correct location and position for the superimposed image, as a rule the various coordinate systems need to be mutually registered. This may be achieved by appropriate calibration procedures.
[0038] By using a common spatial display 1 for the vascular tree 1 ′ with the highlighted path 6 and the instrument position and/or situation, it is easy to check whether the surgical instrument 20 may have strayed too far from the highlighted blood vessel 3 or the planned path 6 and been fed along the wrong branch. If necessary, deviation from the position and/or situation of the surgical instrument 20 can be checked by automated means. If the position of the instrument 20 deviates—preferably the position of the guided end of the catheter 20 —from the highlighted path 6 , this can be visually and acoustically signaled to the surgical staff. Such a comparison can be made for example with the aid of a control unit (not shown in FIG. 1 ) which could also be responsible for allocating the coordinate systems.
[0039] It is even more advantageous if the vascular tree 1 ′, the highlighting for the spatial display 1 and the surgical instrument 20 that is guided during the operation are determined in common, since this enables a different point in time for the capture of the instrument 20 and the vascular tree 1 ′ to be avoided. This could be carried out by means of magnetic resonance angiography in conjunction with an electromagnetic location method.
[0040] By determining the coordinate systems consecutively, for example by suitably highlighting the patient 2 , it is then possible to determine the spatial display 1 of the vascular tree 1 ′, the highlighted blood vessel 3 , and the position and/or situation of the intracranial catheter 20 in common. For this purpose it is necessary to transfer the target point 4 and possibly the access point 5 from preceding spatial displays 1 of the vascular tree 1 ′ or vascular tree section to the next spatial display 1 , so that the blood vessel 3 connecting the target point 4 and the access point 5 can be highlighted again by means of software.
[0041] By means of clearly visible highlighting 30 for the path 6 of the surgical instrument 20 and/or for the target point 4 and/or the access point 5 , and further, reference points 7 to 10 in the spatial display 1 of the hollow space or hollow space system, the safety of the object under investigation 2 can be increased and the work of the surgical staff can be simplified.
|
The invention relates to a method for displaying a hollow space in an object under investigation, wherein the hollow space has an access point and a target point for a surgical instrument which can be introduced at least partially into the hollow space, and wherein a three dimensional image data set of a section of the hollow space having the access point and/or the target point is determined and spatially displayed. By highlighting the access point and/or the target point in the spatial display of the hollow space section it is possible to make a method available which provides the surgical staff with improved guidance in the object under investigation.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority on U.S. Provisional Patent Application No. 60/771,953, filed on Feb. 10, 2006.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to paneling for walls and, more particularly, to a wainscot paneling system and a method of installation.
[0004] 2. Background Art
[0005] Wainscot is a popular decorative paneling system, by which wood planks of various sizes and shapes are installed on a wall from the floor upwardly, to bring wooden ornamentation to the wall of a room. Wainscot brings the rich look of wood to a wall.
[0006] The installation of wainscot to a wall involves a substantial amount of craftsmanship. More specifically, wainscot is an expensive decorative solution, as it is typically customized to a consumer's taste by a craftsman. Various pieces and manpower are required in order to install wainscot on a wall. Permanent fasteners are also used in wainscoting, whereby the wainscot becomes a permanent decorative item.
[0007] Wall paneling systems are typically available as individual parts. It may, therefore, be complicated for consumers to purchase the right amount of parts of wall paneling systems as a function of the length of wall to be covered.
SUMMARY OF INVENTION
[0008] It is an aim of the present invention to provide a novel decorative wall paneling system.
[0009] It is a further aim of the present invention to provide a decorative paneling system that addresses issues of the prior art.
[0010] It is a still further aim of the present invention to provide a method for installing a decorative paneling system on a wall.
[0011] Therefore, in accordance with the present invention, there is provided a kit of decorative paneling for walls, comprising: a lower crosspiece adapted to be positioned at a bottom of a wall; main panels each having a bottom portion shaped so as to be connected to the lower crosspiece; at least one adjustable main panel having a bottom portion shaped so as to be connected to the lower crosspiece, the adjustable main panel having a connector configuration such that a first and a second lateral vertical segment of the adjustable main panel are interconnectable after a central vertical segment is removed from the adjustable main panel to select a length of the adjustable main panel; and posts each having a bottom portion shaped so as to be connected to the lower crosspiece, and lateral edge portions connectable to lateral edges portions of the main panels/adjustable main panel in a decorative configuration of the decorative paneling system; whereby a sequence of main panels/adjustable main panel and posts is received in the longitudinal channel of the lower crosspiece, so as to form decorative paneling of adjustable length for the wall.
[0012] Further in accordance with the present invention, there is provided a method for installing decorative paneling on a wall, comprising the steps of: providing a decorative paneling system having at least one adjustable panel; determining a desired length of the at least one adjustable panel as a function of a length of a wall to cover; removing a central vertical segment from the adjustable panel such that two remaining lateral vertical segments have said desired length when assembled; assembling the two lateral vertical segments to form an adjusted panel with said desired length; and installing the decorative paneling system to the wall using said adjusted panel.
BRIEF DESCRIPTION OF DRAWINGS
[0013] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
[0014] FIG. 1 is a perspective view of walls having a decorative paneling system in accordance with the present invention;
[0015] FIG. 2 is a front elevation view of a kit of decorative paneling system of FIG. 1 , as assembled;
[0016] FIG. 3 is a side elevation view, enlarged, of a female connector edge of a lower crosspiece of the decorative paneling system of FIG. 2 ;
[0017] FIG. 4 is a perspective view of a central post of the decorative paneling system of FIG. 2 ;
[0018] FIG. 5 is a side elevation view, enlarged, of an edge of a main panel of the decorative paneling system of FIG. 2 ;
[0019] FIG. 6 is a front elevation view of the kit of decorative paneling system of FIG. 2 , with an adjustable main panel fitted at the end of a wall;
[0020] FIG. 7 is a front elevation view of the kit of decorative paneling system of FIG. 2 , with a central post fitted at the end of a wall;
[0021] FIG. 8 is a rear exploded view of an adjustable main panel reduced in width; and
[0022] FIG. 9 is a schematic view of an assembly groove of the adjustable main panel.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Referring to the drawings, and more particularly to FIGS. 1 and 2 , a decorative paneling system in accordance with the present invention is generally shown at 10 . The decorative paneling system 10 is also referred to as “wainscot.” The decorative paneling system 10 has lower crosspieces 13 , central posts 14 , main panels 15 , adjustable main panels 15 A, and upper crosspieces 17 . The decorative paneling system 10 may be provided with various sizes of main panel 15 (e.g., height, width).
[0024] In FIG. 2 , a kit of the decorative paneling system 10 is illustrated at 20 . The kit 20 has one lower crosspiece 13 , one upper crosspiece 17 , and an equal number of central posts 14 and main panels 15 / 15 A. In the kit 20 of FIG. 2 , there is provided two main panels 15 and one adjustable main panel 15 A (i.e., a total of three main panels 15 / 15 A), therefore three central posts 14 are provided. Kits with different amounts of panels are also considered.
[0025] When assembled, the parts of the kit 20 form a segment of decorative paneling. The crosspieces 13 and 17 are generally equal in length to the series of central posts 14 and main panels 15 / 15 A assembled in side-by-side relation, as illustrated in FIG. 2 . The kit 20 may also include, although not shown, moldings and the like.
[0026] The parts of the kit 20 are preferably provided with a connector configuration allowing easy assembly of the decorative paneling. One contemplated connector configuration is now described.
[0027] Referring to FIG. 3 , the lower crosspiece 13 has an elongated vertically positioned rectangularly shaped body 30 . The body 30 has an exposed surface 31 and a hidden surface 32 . The exposed surface 31 and the hidden surface 32 are separated by vertical edge surfaces 33 (only one of which is shown in FIG. 3 ), and by a bottom edge surface (not visible) and a female connector edge 35 facing upwardly. The illustrated vertical edge surface 33 and the bottom edge surface are generally flat. The female connector edge 35 defines a longitudinal channel 36 , of rectangular cross-section.
[0028] Holes 37 are provided in the illustrated vertical edge surface 33 , so as to receive connectors (e.g., connector pegs) for interconnecting lower crosspieces 13 end to end. An opposed vertical edge surface (not visible) is provided with a complementary connector configuration, such as a channel or corresponding peg holes. The upper crosspiece 17 is essentially an upside-down version of the lower crosspiece 13 , in that it has a downwardly facing female connector edge, as well as a connector configuration at the vertical edge surfaces for end-to-end connection of the upper crosspieces 17 .
[0029] Referring to FIG. 4 , the central post 14 is shown having an upstanding elongated rectangularly shaped body 40 . The body 40 has an exposed surface 41 and a hidden surface 42 . The exposed surface 41 and the hidden surface 42 are separated from one another by edge surfaces 43 at top and bottom ends of the body 40 , and female connector edges 44 at the sides of the body 40 . As best seen in FIG. 4 , the edge surfaces 43 define a generally flat surface having holes provided to receive connector pegs 45 . The female connector edges 44 each have a longitudinal channel 46 . It is pointed out that the connector pegs 45 of the central post 14 have a shape complementary to the longitudinal channel 36 of the lower crosspiece 13 so as to be received therein. Moreover, the longitudinal channel 46 of the central post 14 generally has the same cross-sectional shape as the longitudinal channel 36 of the lower crosspiece 13 .
[0030] Referring to FIG. 5 , the main panel 15 / 15 A is shown having a rectangularly shaped body 50 . The body 50 has an exposed surface 51 and a hidden surface 52 . The exposed surface 51 typically has some ornamentation, molding and/or shaping. For instance, in FIG. 5 , the exposed surface 51 has a protruding surface portion 53 with sloping periphery 54 . The exposed surface 51 is separated from the hidden surface 52 by flat edge surfaces 55 of the body 50 . The flat edge surfaces 55 form a square edge portion to be received in the longitudinal channel 36 of the lower crosspiece 13 and similarly in the upper crosspiece 17 ( FIG. 3 ), and in the longitudinal channels 46 of the central post 14 ( FIG. 4 ). Therefore, the parts of the kit 20 can be assembled to form the segment of decorative paneling of FIG. 2 with the connector configuration described previously.
[0031] The lip/channel configuration is preferably used to interconnect the main panels 15 / 15 A of the decorative paneling system 10 to posts 14 and crosspieces 13 and 17 . The central posts 14 and/or the adjustable posts 16 are provided with pegs or dowel pins. As described previously, the pegs or dowel pins are then received in the channels of the adjacent panels. This represents a cost-effective solution.
[0032] In order to adjust the decorative paneling system 10 to a length of wall to be covered, the adjustable main panel 15 A is configured to be reduced in size. More specifically, referring concurrently to FIGS. 5 , 6 and 8 , it is seen that the adjustable main panel 15 A is the same in shape and dimensions as the main panel 15 (whereby like reference numerals are used to represent like elements). However, a pair of parallel horizontal grooves 60 are provided in the hidden surface 52 of the adjustable main panel 15 A.
[0033] Referring to FIG. 9 , a cross-section of one of the grooves 60 is illustrated. The cross-sections have a dovetail shape in the illustrated embodiment. The adjustable main panel 15 A is cut vertically to remove a central vertical segment, in order to be shortened in length. As shown in FIG. 8 , once the two remaining lateral vertical segments of the adjustable main panel 15 A are sized to form a panel of desired length when positioned side by side, splines 61 (which are part of the kit 20 ) are used to interconnect the main panel segments, to form an adjusted main panel 15 A′ of reduced dimensions ( FIGS. 1 and 6 ), having a full sloping periphery 54 ( FIG. 6 ). The splines 61 are inserted into the grooves 60 and the lateral vertical segments are brought together in side-by-side contact. As an example, the central vertical segment is sawn off (e.g., at the installation site) so as to create the two lateral vertical segments.
[0034] The grooves 60 /spline 61 configuration is advantageous in that it ensures the planar interconnection of main panel segments. It is in fact desired that the resulting exposed surface 51 be flat when the panel segments are interconnected to form the main panel 15 A′ of reduced length, so as to reduce the visibility of the seam between the two lateral vertical segments. It is pointed out that more or fewer grooves 60 may be provided in an adjustable main panel 15 A. Alternative connector configurations are considered (e.g., use of glue, dowel pins in combination with drilled holes) between lateral vertical segments.
[0035] The grain in the adjustable main panels 15 A is preferably vertical in instances where the main panels 15 / 15 A show wood grain, so as to reduce the visibility of the vertical interconnection line between interconnected panel segments.
[0036] The central posts 14 may also be reduced in length by being cut vertically, to fit between an adjacent main panel 15 / 15 A and a wall intersection. However, considering that no molding pattern (e.g., sloping periphery 54 of the panel 15 A′ in FIG. 6 ) must be preserved, the central posts 14 are simply cut vertically to remove an unwanted segment. One such central post of reduced length is illustrated at 14 A in FIG. 7 .
[0037] In order to install the decorative paneling system to a wall, an adhesive, such as silicone, a glue or the like, is deposited on the hidden surface 32 of the lower crosspiece 13 ( FIG. 3 ), which is then pressed against the wall so as to remain in position thereagainst. It may be required that lower crosspieces 13 be put end to end in the event that the wall is too long for a single lower crosspiece 13 . In such a case, connector pegs in the holes 37 ( FIG. 3 ) are used to connect crosspieces end to end. Alternatively, other fasteners such as nails or other suitable mechanical fasteners may be used. In the event that mechanical fasteners are used, it is suggested to position these fasteners where they will be hidden, for instance, by moldings (e.g., reversed ogee, plinth).
[0038] Thereafter, a sequence of central post 14 (with suitable connector pegs 45 of FIG. 4 ) and main panel 15 / 15 A are positioned side by side with respective exposed surfaces 41 and 51 facing away from the wall. It is suggested to start from a central portion of the wall, with a main panel 15 if an odd number of panels 15 fit on the wall (with respect to the sequence of central posts 14 and main panels 15 ), or with a central post 14 if an even number of panels fit on the wall (again with respect to the sequence). More specifically, it is the connector pegs 45 of the central post 14 , and one of the edges 55 of the main panel 15 , that are received in the longitudinal channel 36 of the lower crosspiece 13 .
[0039] Referring to FIG. 1 , the central posts 14 and the main panels 15 are in a side-by-side relationship, with one of the edges 55 of the main panel 15 being received in one of the longitudinal channels 46 of the central post 14 . In the event that the sequence of central post 14 and main panel 15 / 15 A stops at the central post 14 adjacent to an end of the wall, with a gap between the central post 14 and the adjacent intersection of walls being too small to be breached by a full main panel 15 / 15 A, the adjustable main panel 15 A is reduced in length into panel 15 A′, in the manner illustrated in FIG. 8 , to fit between the central post 14 and the intersection of walls. This results in the paneling as illustrated in FIG. 6 .
[0040] Alternatively, if the sequence of central post 14 and main panel 15 stops at the main panel 15 with a gap smaller than the length of the central post 14 , the central post 14 has a vertical segment removed therefrom to form central post 14 A in the manner illustrated in FIG. 7 .
[0041] Other sequences are possible, such as an adjusted main panel 15 A′ centrally positioned on a wall with full main panels 15 on opposed sides of the adjusted main panel 15 A′.
[0042] Nails and other suitable fasteners may be used, for instance, in portions of the panels 15 / 15 A and posts 14 that will not be visible, e.g., hidden by moldings, once the complete decorative paneling system 10 is installed.
[0043] Once the sequence of central posts 14 and main panels 15 / 15 A has been installed, the upper crosspiece 17 is installed. More specifically, the longitudinal channel of the upper crosspiece 17 will host the exposed edges 55 ( FIG. 5 ) of the main panels 15 / 15 A, as well as the connector pegs 45 ( FIG. 4 ) of the central posts 14 , which are jointly paneling the wall.
[0044] If desired, nails (or other suitable fasteners) may be used to secure the upper crosspiece 17 to the panels 15 / 15 A and posts 14 , and to the wall. As various moldings will be positioned on the upper crosspiece 17 , it is contemplated to use mechanical fasteners in locations that will be hidden by the moldings.
[0045] Referring to FIG. 1 , various decorative pieces may be used to cover the lower crosspiece 13 (plinths), the upper crosspiece 17 (upper crosspiece cover) and corners (e.g., corner covers), as well as top molding. Such decorative pieces are secured to a remainder of the paneling system 10 by way of an adhesive or mechanical fasteners. Alternatively, the panels 13 , 14 , 15 / 15 A and 17 may each be preshaped to incorporate moldings. The panels of the kit 20 , and additional decorative pieces, are preferably veneer panels, of different varieties of wood and of various wood grain. The panels of the kit 20 may be painted or varnished to provide a customized appearance to the decorative paneling system 10 .
[0046] By selling the panels of the above-mentioned decorative paneling system 10 in kits 20 , it is only required to know the length of wall to be covered. The kit 20 typically indicates the maximum length of wall covered by the assembled kit 20 .
|
A kit of decorative paneling for walls and method for installation therefor, comprises a lower crosspiece, and main panels connected to the lower crosspiece. Adjustable main panels are connected to the lower crosspiece, and have a connector configuration such that a first and a second lateral vertical segment of the adjustable main panel are interconnectable after a central vertical segment is removed from the adjustable main panel to select a length of the adjustable main panel. Posts are connected to the lower crosspiece, with lateral edge portions connectable to lateral edges portions of the main panels/adjustable main panel in a decorative configuration of the decorative paneling system, whereby a sequence of main panels/adjustable main panel and posts is received in the longitudinal channel of the lower crosspiece, so as to form decorative paneling of adjustable length for the wall.
| 4
|
This invention was made with government support under Grant 5-R37-DK-14334-21 awarded by the National Institutes of Health. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
This invention relates to substances which mimic the action of insulin.
It has long been known that the cellular metabolic actions of Insulin involve the generation of a low molecular weight substance that mimics certain actions of insulin. See, U.S. Pat. No. 4,446,064. An inositol glycan structure was first proposed for an insulin mediator in 1986. See, Saltiel, A. R. et al. Proc. Nat. Acad. Sci. Vol. 83, pp 5793-97 (1986). Since these initial studies, structural variations in the insulin mediator have been reported in a number of laboratories. See, Saltiel, Second Messengers of Insulin Action, Diabetes Care, Vol, 13, No. 3, pp.244-256 (1990). Specifically, compositional analyses from the laboratory of Larner demonstrated the presence of significant amounts of D-chiroinositol and galactosamine as features of the inositol glycan structure. Larner et al., Biochem. Biophys. Res. Comm. Vol. 151, pp.1416-26 (1988). Despite progress in identifying the structure and biogenesis of inositol glycans released from the plasma membrane in response to insulin, identification of the precise biological utility of these compounds will depend upon the precise structural identification and examination of their insulin mimetic properties.
The identification of substances that mediate or mimic the action of insulin could lead to the development of novel structures which may be of clinical use in the treatment of persons having disorders of glucose metabolism, such as impaired glucose tolerance, elevated blood glucose associated with Type II diabetes, and insulin resistance.
Insulin mimetic molecules extracted from biological sources present a variety of undesirable characteristics, including possible contamination as well as unreliable or limited sources of supply of naturally occurring molecules. It is, therefore, desirable to devise a synthetic molecule which mimics the activity of insulin or its mediators and which can be synthesized without resort to extracts from animal tissue.
SUMMARY OF THE INVENTION
It has been found that certain small amino disaccharides can mimic the action of insulin. Specifically, they act to reduce elevated blood glucose levels. These substances consist of an amino sugar moiety and inositol, joined by a beta linkage. Derivatives of these disaccharides also act to reduce elevated blood glucose levels. Examples of amino sugars used in the present invention include glucosamine and galactosamine. The 2-deoxy form of these compounds is most preferred (e.g., 2-deoxy-2-amino hexapyranosyl inositols). Amino disaccharides of the present invention include molecules consisting of amino derivatives of galactopyranose and isomers and derivatives of inositol. Compounds such as 2-deoxy-2-amino-galactopyranosyl pinitol are most important in this regard. It has also been found that beta anomers are most important.
Examples of substances within the scope of this invention include various derivatives of these amino disaccharides, such as 4'-O-(2 deoxy-2-amine-D-galactopyranosyl)-D-pinitol-5'-phosphate or 4'-O-(2 deoxy-2-amine-D-galactopyranosyl)-D-pinitol-2'-phosphate.
DESCRIPTION OF THE FIGURES
FIG. 1 is an illustration of the numbering system used to describe compounds of the present invention.
FIGS. 2 through 7 illustrate synthetic pathways used to prepare compounds of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention contemplates a broad range of compounds. The amino sugar component of these compounds is preferably a hexosamine or a pentose amine, with hexose amines, such as allosamine and gulosamine generally preferred, especially glucosamine, and galactosamine. Among the inositols, chiroinositol and myoinositol are preferred. The numbering system used to describe the compounds of the present invention is shown in FIG. 1.
The hydroxyl groups of both the amino sugar and the inositol component may be replaced by a variety of substituents. Alkoxy, aryloxy, ether, ester, and phosphate group replacements are useful in protecting the molecule, modifying its hydrophilicity or modulating its insulin-mimetic properties. Replacement of the hydroxyl group at the number 3 position of chiroinositol is preferred, with replacement with a methoxy group (i.e. pinitol) especially preferred. Substitutions at the 2 and 1 positions of chiroinositol (as well as at the corresponding positions of other inositol components) are also preferred.
Insulin mimetics of this invention can be prepared in the following manner.
The beta-glycosides of 2-deoxy-2-amino sugars with derivatives of inositol of this invention are prepared by the reaction of an appropriately protected amino sugar precursor having a leaving group at the 1-position (glycosyl donor) with a free hydroxyl group of a suitably protected inositol (glycosyl acceptor) in the presence of a promoter, followed by deprotection. For example, 4'-O-(2-deoxy-2-amino-b-D-galactopyranosyl)-D-pinitol is prepared by the glycosylation/deprotection sequence shown in Scheme 1, which is set forth in FIG. 2.
The glycosyl donor, 1-bromo-1,2-dideoxy-3,4,6-tri-O-acetyl-2-dinitrophenylaminogalactose, is prepared as shown in Scheme 2, which is set forth in FIG. 3, and described in detail below.
Other glycosyl donors are prepared by straight forward synthetic manipulation of available precursors. For instance, selective derivatization of the 4-position of galactal can be achieved by treating the compound with 2-equivalents of t-butyldimethylsilyl chloride as shown in Scheme 3, which is set forth in FIG. 4. Compound A can be easily converted to an ether or ester by known Williamson or Schotten-Bauman techniques. Azidonitration and bromide displacement on B provides a glycosyl donor which, following reaction with a glycosyl acceptor in the presence of silver silicate, reduction of the azido group by hydrogenation and deprotection with fluoride, yields a beta-glycoside of 2-deoxy-2-aminogalactose substituted at the 4-position with an ether or an ester.
Similarly, as is shown in scheme 5 which is set forth in FIG. 5, compounds C and D can be easily separated and converted into beta-glycosides of 2-deoxy-2-aminogalactose substituted at the 3 or 6-position with an ether or an ester.
The glycosyl acceptor, 1',2';5',6'-di-O-isopropylidene-D-pinitol, used in the synthesis of 4'-O-(2-deoxy-2-amino-beta-D-galacopyranosyl)-D-pinitol as in Scheme 1 was prepared by the reaction of D-pinitol with dimethoxypropane in the presence of a catalytic amount of p-toluenesulfonic acid. Other glycosyl acceptors can be prepared readily. For instance, compounds E and F, which can be prepared as shown in Scheme 6, which is set forth in FIG. 6, can be mono or dialkylated regioselectivly using Williamson techniques. Glycosides containing chiroinositols with alkoxy substituents at the 2 and 6 positions can be obtained by catalytic debenzylation of G to give glycosyl acceptor H as set forth in FIG. 7, followed by glycosylation of H and deprotection using standard techniques. Similarly, glycosides containing chiroinositols with alkoxy substituents at the 1 and 5-positions can be prepared from G.
I. Preparation of 4'-O-(2-deoxy-2-amino-beta-D-galactopyranosyl)-D-chiroinositol.
A detailed procedure for preparing this compound is as follows.
1. Preparation of 1',2';5',6'-di-O-isopropylidene-3-O-(trimethylsilylethoxymethyl)-D-chiroinositol.
1,2;5,6-Di-O-isopropylidene-D-chiroinositol (942 mg), 0.83 ml of trimethylsilylethoxymethyl chloride (SEM-Cl) and 1.9 ml of diisopropylethyl amine (DIPEA) were dissolved in 20 ml of dry methylene chloride and refluxed for 16 hours. The solution was concentrated in vacuo and the last traces of volatile material were removed under high vacuum (500 m Torr) for four days to yield pure product. The yield was 1.04 g (73%).
2. Preparation of 2-deoxy-2-dinitrophenylamino D-galactose.
Galactosamine hydrochloride (10 g) was stirred with 20 ml of distilled acetone and 50 ml of deionized water. 2,4-Dinitrofluorobenzene (5.8 ml) was added followed by 4.9 g of sodium carbonate. The mixture was stirred at room temperature for 18 hours when a yellow precipitate was formed. The material was suction filtered to dryness, dissolved in 30 ml of dry methanol. Benzene (120 ml) was added followed by enough hexane to make the solution slightly cloudy (approximately 50 ml) at which time the cloudy suspension was seeded to produce 5.6 g (35%) of the product.
An alternate procedure was used to concentrate the mixture after 18 hours reaction time and load the crude material on a 3×20 cm flash column packed with silica gel 60 and elute the column with 3:1 chloroform:isopropanol and removing the solvent in vacuo to dryness. From 6 g of galactosamine hydrochloride, 3.48 ml of dinitrofluorobenzene, 2.94 g of sodium carbonate, 30 ml of water and 120 ml of acetone, 7.37 g (77%) of the product was obtained.
Preparation of 1,3,4,6-tetra-O-acetyl-2-deoxy-2-dinitrophenylamino-D-galactose.
2-Deoxy-2-dinitrophenylamino galactose (7.37 g) was dissolved in 50 ml of dry pyridine and the solution was cooled to 0° C. Acetic anhydride (50 ml) was added and the solution stirred for ten hours while allowing to warm to 10°-15° C. The solution was poured into 500 ml of ice water and the mixture was suction filtered. The precipitate was recrystallized from 500 ml hot 95% ethanol to yield 11.06 g (100%) of the product.
3.Preparation of 1-bromo-1,2-dideoxy-2-dinitrophenylamino-3,4,6-tri-O-acetyl-D-galactose.
1,3,4,6-Tetra-O-acetyl-2-deoxy-2-dinitrophenylamino-galactose (6.83 g) was moistened with 12 ml of dry chloroform and cooled to 0° C where 100 ml of 30% hydrogen bromide in acetic acid was added dropwise and the solution was stirred for two hours after the addition was complete. The solution was poured into 350 ml of ice water and extracted with 4×100 ml of chloroform. The combined chloroform extracts were washed with 2×100 ml saturated aqueous sodium bicarbonate, 100 ml of water, dried over magnesium sulfate, filtered and concentrated in vacuo. After 25 hours of drying under high vacuum, 7.08 g (99%) of the product was obtained.
1. Glycosylation procedure to prepare 4'-O-[3,4,6-tri-O-acetyl-2-deoxy-2-dinitrophenylamino- ,β-D-galactopyranosyl]-3'-O-trimethylsilylethoxymethyl-1',2';5',6'-di-O-isopropylidene-D-chiroinositol.
Vacuum dried 1-bromo-1,2-dideoxy-3,4,6-tri-O-acetyl-2-dinitrophenylamino-D-galactose (170 mg) and 1,2;5,6-di-O-isopropylidene-3-O-(trimethylsilylethoxymethyl)-D-chiroinositol (100 mg) were dissolved in 10 ml of dry methylene chloride and the solution stirred at room temperature. Under a nitrogen shroud, 500 mg of freshly activated 4 angstrom powdered molecular sieves was added and stirred for one hour. At that time 0.04 ml of tetramethyl urea and 82 mg of silver triflate were added under a nitrogen shroud. The heterogeneous mixture was stirred at room temperature for 21 hours where three drops of triethylamine was added; the mixture was filtered and the solvents removed in vacuo. The crude material was loaded on a 2×25 cm flash column packed with silica gel 60 and the column was eluted with 790 ml of 4:1 petroleum ether:ethyl acetate and 100 ml of 2:1 petroleum ether:ethyl acetate to isolate 90 mg of the--isomer (23%) and 42 mg of the beta-isomer (19%)
1.Preparation of 4'-O-[2-deoxy-2-amino-beta-D-galactopyranosyl]-3'-O-trimethylsilylethoxymethyl-1',2';5',6'-di-O-isopropylidene-D-chiroinositol.
4'-O-[3,4,6-Tri-O-acetyl-2-deoxy-2-dinitrophenylamino-beta-D-galactopyranosyl]-3'-O-trimethylsilylethoxymethyl-1',2';5',6'-di-O-isopropylidene-D-chiroinositol (37.5mg) was stirred with 3.5 ml of 1M aqueous lithium hydroxide and 7 ml of dioxan and heated to 90° C. for 28 hours. Acetic acid (4 ml) was added to pH 5 and the solvents were removed in vacuo. The residue was dissolved in methanol, 1 g of silica gel 60 was added and the methanol was removed in vacuo. The preabsorbed material was loaded on a 1×15 cm flash column packed with silica gel 60 and the column was eluted with 3:1 chloroform:isopropanol to isolate 22.1 mg of the product (90%) .
2.Preparation of 4'-O-[2-deoxy-2-amino-beta-D-galactopyranosyl]-D-chiroinositol.
4'-O-[2-Deoxy-2-amino-beta-D-galactopyranosyl]-3'-O-trimethylsilylethoxymethyl-1',2';5',6'-di-O-isopropylidene-D-chiroinositol (124 mg) was dissolved in 10 ml of 80% acetic acid and the solution heated to 75° C. for 18 hours. The solvents were removed in vacuo to yield 76 mg (99%) of the product. The product was further purified using HPLC with a C 18 stationary phase and a water eluant.
1. Preparation of 4'-O-(2-deoxy-2-amino-beta-D-galactopyranosyl)-D-pinitol.
A detailed description of the synthetic pathway by which this compound is prepared is as follows.
2. Preparation of 4'-O-[2-deoxy-2-dinitrophenylamino-3,4,6-tri-O-acetyl-beta-galactopyranosyl]-1',2';5',6'-di-O-isopropylidene-D-pinitol.
Vacuum dried 1-bromo-1,2-dideoxy-3,4,6-tri-O-acetyl-2-dinitrophenylamino-galactose (3.9 g) and 1 g of 1,2;5,6-di-O isopropylidene-D-pinitol were dissolved in 100 ml of dry methylene chloride and the solution stirred at room temperature. Under a nitrogen shroud, freshly activated 4 angstrom powdered molecular sieves was added and the mixture stirred for one hour. At that time 0.87 ml of tetramethyl urea and 1.86 of vacuum dried silver triflate was added under a nitrogen shroud and the mixture stirred at 0° C. for 18 hours. The mixture was filtered and the filtrate was dried in vacuo. The crude oil was loaded on a 5×20 cm flash column packed with silica gel 60 and the column was eluted with 2:1 petroleum ether:ethyl acetate to yield 2.108 g (76%) of the beta anomer.
3.Preparation of 4'-O-[2-deoxy-2-amino-beta-D-galactopyranosyl]-1',2';5',6'-di-O-isopropylidene-D-pinitol.
4'-O-[3,4,6-Tri-O-acetyl-2-deoxy-2-dinitrophenylamino-beta-D-galactopyranosyl]-1',2';5',6'-di-O-isopropylidene-D-pinitol (902.1 mg) was stirred with 3.5 ml of 1M aqueous lithium hydroxide and 7 ml dioxan and heated to 95° C. for 72 hours. Acetic acid (2 ml) was added and the solvents were removed in vacuo. The crude material was loaded on a 2×10 cm flash column packed with silica gel 60 and eluted with 3:1 chloroform:isopropanol to yield 361 mg (61%) of the product, which was recrystallized from isopropanol to yield 74 mg of crystalline product.
4. Preparation of 4'-O-(2-deoxy-2-amino-beta-D-galactopyranosyl)-D-pinitol.
4'-O-[2-Deoxy-2-amino-beta-D-galactopyranosyl]-1',2';5',6'-di-O-isopropylidene-D-pinitol (101 mg) was dissolved in 5 ml of 80% acetic acid and the solution heated to 75° C. for 24 hours. The solvents were removed in vacuo. The residue was passed through a C-18 Millipore cartridge and eluted with acetonitrile. The residue (which weighed 64 mg) was recrystallized from isopropanol to yield 25 mg of the product.
Reduction of Elevated Blood Glucose Concentration
These compounds are useful in the treatment of defects in glucose metabolism such as impaired glucose tolerance insulin resistance, or the elevated blood sugar associated with type II diabetes. For example, rats were injected intravenously with 70 mg/kg of streptozotocin. After ten days, when resultant hyperglycemia was established, the animals were anesthetized with ketamine and zero time blood glucose levels were established by way of tail vein sampling. An experimental group was given 2 mg/kg 4'-O-(2-deoxy-2-amino-beta-D-galactopyranosyl)-D-pinitol by intravenous injection via the tail vein, and a control group was given an equal volume of saline. Blood glucose levels were measured over time in both groups. All measurements were made while the subjects were under ketamine anesthesia. Evaluation of the time course data by two-way analysis of variance indicated a significant overall effect of the disaccharide to lower blood glucose concentration (p<0.01). Thirty minutes after administration of the disaccharide, blood glucose levels were decreased from pretreatment concentration by 30% (±9.5) in the experimental group, while levels in the control group decreased only 2.5% (±2.6).
Compounds according to the present invention can be administered byway of a preparation containing a suitable carrier and an effective amount of the compound. Doses in the range of 0.1 to 10.0 mg/kg are preferred, with the range of 1.0 to 2.0 mg/kg most preferred.
|
A synthetic insulin mimetic compound is disclosed. Small synthetic amines of disaccharides, such as 2-deoxy-2-amino-galactopyranosyl pinitol are shown to mimic the action of insulin and to modulate its action.
| 8
|
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to septic tank cover systems, and more particularly to septic tank cover systems which are designed to provide access to septic tanks, seal septic tanks from water, and prevent tank leakage.
II. Discussion of the Prior Art
It is well known that access to septic tanks buried underground is periodically needed so that material can be pumped from the tank and maintenance performed. It is important for structures which provide access to the tanks to maintain a water tight environment leading to the buried septic system. The seals for these structures are greatly susceptible to leaks due to their exposure to an outdoor conditions. Frost heaving, forces related to vertical ground movement, and rotational forces due to lateral ground movement can each have a potentially detrimental impact on the integrity of septic tank access structures.
To improve the longevity and durability of access points to septic tanks, it is desirable, as much as possible, to protect the structure from potentially damaging types of ground forces. Various aspects of these problems have been addressed in some previous disclosures although a design specifically suited to properly address these concerns has never been as fully and effectively designed before. For example, in the Meyers. U.S. patent application Pub. No. 2003/0145527, a riser component for an on-site waste system is described which incorporates a riser pan, a cover, and various interconnecting riser elements. The Airhart U.S. Patent Application Pub. No. 2004/0040221 is directed at a molded manhole unit. This application shows a unit with a manifold riser having a beveled riser edge, a riser extension which mates with the manifold riser, a sealing ring, and a riser cap.
The present invention offers important advantages over the prior art due to new concepts included in its design. Specifically, the arrangement of the riser base of the present invention offers several superior features not found in the prior art. These features relate to the ledge and depressions below the ledge that allow secure anchoring of the device into a concrete casting. These advantages also include the uninterrupted surface upon which the pipe member can rest. This surface provides an effective mechanism for sealing the junction between the base and the pipe. The use of corrugated pipe also provides certain advantages in terms of cost, strength, and the ability for one to cut the pipe to length rather than having to buy a specific piece of a specific height. The invention overcomes the problems associated with using such a pipe by providing a novel sealing surface between the pipe and the top cover, a novel sealing arrangement between the riser base and the pipe, and also by providing a sleeve that covers the corrugations in the pipe to prevent the pipe from coming loose from the base due to ground forces. Finally, the manner in which the top cover of the present invention engages the pipe to provide an effective seal that is much more refined and simple than what is shown in the prior art.
SUMMARY OF THE INVENTION
The present invention provides for a cover system for septic tanks which is adapted to be attached to a septic tank and provide a water tight seal access for pumping the contents of the tank and maintaining the tank. The assembly includes a base member which is embedded into the concrete of an underground septic tank providing a seal between the concrete and the base. A pipe member is joined to and sits atop this stationary base member. A wrap made of high density polyethylene surrounds the pipe and covers its corrugations to reduce outside forces upon the pipe. Additionally, there is a top cover which is designed to engage the top of the pipe. Further, a channel is provided on the base to catch the edge of the pipe, novel seals are provided to prevent leakage between the pipe and cover and between the pipe and base. These features work together to form a stable and water tight structure for closing an access opening to a septic tank.
These and other objects, features, and advantages of the present invention will become readily apparent to those skilled in the art through a review of the following detailed description in conjunction with the claims and accompanying drawings in which like numerals in several views refer to the same corresponding parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the septic cover assembly of the present invention without the outer wrap member;
FIG. 2 is a perspective view of the base member of the septic cover assembly;
FIG. 3 is a perspective view of the pipe member of the septic cover assembly;
FIG. 4 is a perspective view of the cover member of the septic cover assembly;
FIG. 5 is a perspective view of the septic cover assembly without the outer wrap member; and
FIG. 6 is a perspective view of the septic cover assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention represents broadly applicable improvements for septic tank design to provide an effective sealed means and stable structure for accessing a septic tank. The embodiments herein are intended to be taken as representative of those in which the invention may be incorporated and are not intended to be limiting.
Referring first to FIG. 1 , there is a perspective view of the septic cover assembly shown which would be buried in the ground and cemented in place to provide convenient access to a septic tank from above the ground. The assembly itself is indicated generally by numeral 10 and includes a base 12 , a pipe 14 , a top cover 16 , and a wrap 17 (see FIG. 6 ). These four components work together to form an invention which create a passageway of structural integrity well-suited for continued and efficient access to a desired septic tank.
FIG. 2 discloses a perspective view of the base member 12 of the septic cover assembly allowing for a more detailed examination of its features. Base 12 is a largely cylindrical component which is made of high density polyethylene. It provides a riser coupling which is primarily embedded within concrete and forms a seal between the concrete and the base 12 . The riser coupling has a 24-inch opening providing access to the concrete tank in which the base 12 is embedded. Base 12 is comprised of four annular sections 18 , 20 , 22 , and 24 . The first annular section 18 is made up of a cylindrical wall containing a plurality of depressions 26 which fill with concrete that encapsulates section 18 of the base member 12 when concrete is poured around it. This arrangement prevents the base member from rotating in the concrete.
Directly above first annular section 18 is a second annular section, ledge 20 . Ledge 20 is an annular protrusion which extends radially outward to achieve a diameter substantially larger than the previous diameter of section 18 . Ledge 20 has an upper lip 28 and a lower lip 30 that diverge from one another as the annular protrusion extends radially outward. Lip 28 and lip 30 are joined by a vertically disposed outer surface 31 . These features prevent the base member from moving up or down with respect to the tank when the ledge 20 is embedded in the concrete. These features of ledge 20 also stiffen the upper structure of the base when the ledge 20 is fully encapsulated by concrete.
Juxtaposed directly above ledge 20 is a third annular section 22 . Section 22 has a smaller diameter than ledge 20 . The top rim edge 32 of rim 22 marks the height to which concrete is filled when poured around base 12 . The rim edge 32 is the feature pipe 14 abuts up against when it is slid onto base 12 , as will be later discussed. The edge 32 also assists in providing a water tight seal between the pipe 14 and the base 12 .
The last annular section is a riser coupling 24 which has a cylindrical portion 34 of constant diameter and an inwardly projecting lip 36 . This section provides a sturdy projection which mates with and is generally covered by pipe 14 . It also provides a further barrier to the outside environment.
Referring now to FIG. 3 , a section of pipe 14 is shown. Pipe 14 is a 24-inch diameter dual wall pipe. The pipe must extend from the base 12 when it is buried underground to above ground level. Thus, dual wall pipe is used that can be cut to length. The length of pipe is typically cut at the time of installation and is made between the corrugations. Only the length of two corrugations of pipe are shown in FIG. 3 although various much longer lengths of pipe containing many more corrugations are common. The pipe 14 is designed to be slid over the top of the riser coupling 24 so that the bottom edge 38 of the pipe 14 will come in contact with the concrete filled to rim edge 32 . A seal can be provided at the intersection of the pipe 14 and the concrete to prevent leakage.
Pipe 14 has a smooth inner wall 40 and a corrugated outer wall 42 (i.e. with grooves and ridges, as seen in FIGS. 1 , 3 and 5 ). The corrugations serve to strengthen the pipe. Because this cut-off edge can be non-uniform, it is not a suitable surface for sealing. Therefore, for an effective seal to be made between the pipe 14 and the cover 16 , one must be made on the top surface 44 of the top corrugation of the pipe.
FIG. 4 shows the cover 16 of the present invention. The cover generally comprises a flat upper disc component 46 and a lower cylinder component 48 protruding downward from the upper disc 46 . The lower cylinder 48 is formed so that it may be inserted snugly within the smooth inner diameter of pipe 14 . The upper disc 46 maintains a diameter slightly larger than the corrugated outer wall of the pipe 42 and is the above ground, exposed portion of the cover system 10 . In the area surrounding the lower cylinder's protrusion from the upper disc is a slightly raised ring of material 48 . This portion of the upper disc 46 is the contact surface corresponding to the seal on the top corrugation surface 44 of pipe 14 . The mating established between the cover surface 48 and the seal is water tight. Additionally, there is an inclined surface 49 between the flat outer portion of the disc and the raised material 48 . The upper disc 46 of cover 16 contains multiple holes 50 around its periphery which can be used to place a padlock or some other kind of locking mechanism for the prevention of unauthorized access to the septic system. Two cylindrical depressions 52 also exist on the top surface of the cover (see FIG. 5 ).
FIG. 5 shows the cover 16 , pipe 14 , and base 12 of the device as they would be in an assembled device, absent the wrap 17 . Cylindrical depressions 52 are shown as well. Suitable gaskets or other sealing materials are also provided in the seal ares between the pipe 14 and the concrete and between the relatively flat area of the top corrugation of the pipe 14 and the cover.
FIG. 6 discloses the final component of the device, wrap 17 , added to the assembly. Wrap 17 is made of high density polyethylene material which surrounds the pipe 14 . Often the corrugations of pipe 14 present a problem when the pipe is buried in the ground, due to frost or other heaving of the surrounding soil. This can cause the pipe to actually be lifted off of the base 12 due to the forces imparted by changing soil conditions. Wrap 17 is intended to prevent this heaving problem. Wrap 17 surrounds the pipe and covers the corrugations so that forces caused by frost or the like are not applied to bottom portions of the corrugations in the pipe. Such forces are what would otherwise cause the pipe to be lifted from the base. The wrap provides a smooth outer wall surface rather than the corrugations in the pipe.
Now that the details of the mechanical construction of the septic cover assembly 10 of the present invention have been described, consideration will next be given to its mode of operation.
During construction of an underground concrete septic tank, the base member 12 in imbedded into the concrete. The concrete surrounds the outer edge of base member 12 such that concrete, embeds within depressions 26 , completely encapsulates ledge 20 , and extends to the level of rim edge 32 and top of the concrete. A watertight attachment is thus formed between the tank, the base member 12 and the bottom of pipe 14 . Once the concrete hardens, the tank is placed in a hole in the ground. The pipe 14 is cut such that the top of the pipe is approximately even with or slightly above ground level. A seal such as a gasket is positioned so that it surrounds the base member 12 . Corrugated pipe 14 is slid over the exposed riser coupling 24 of the base and up against the channel formed by the rim edge 32 . Next, a seal is placed along the pipe's top corrugation surface 44 as opposed to the cut edge which tends to be uneven. A cover 16 is then placed within and above pipe 14 , engaging against the seal on the top corrugation surface 44 to form a second watertight connection. The cover 16 is locked with a padlock and opened when access is needed for maintenance or repair of the septic tank.
It can be seen, then, that the present invention provides an improved and efficient apparatus for gaining access to a septic tank which functions to effectively seal the tank from water and prevent tank leakage.
This invention has been defined herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself.
|
A cover system for septic tanks adapted to be attached to the a septic tank and provide access for repair and maintenance. The assembly includes a base which is embedded into the concrete and provides a seal between the concrete and the base. A pipe member is joined to and sits atop the stationary base member. A wrap made of high density polyethylene surrounds the pipe and covers its corrugations to reduce outside forces upon the pipe. Finally, there is a top cover which is designed to engage the top of the pipe. Additionally, a channel is provided to catch the edge of the pipe and a seal is provided to prevent leakage between the pipe and cover.
| 4
|
FIELD OF THE INVENTION
The present invention relates to a method for the synthesis and utilization of cross-linked substituted polystyrene copolymers as surface treatments (PXSTs) for control of the orientation of the physical features of a block copolymer deposited over the first copolymer. Such methods have many uses including multiple applications in the semiconductor industry including production of templates for nanoimprint lithography.
BACKGROUND OF THE INVENTION
Appropriately structured block copolymers (BCs) self-assemble into regular patterns with features that are less than 100 nm [1] and can be exploited in nanomanufacturing applications such as microelectronics, solar cells, and membranes. Hexagonally packed cylinders aligned perpendicular to the substrate surface are one of the more useful nanostructures for these applications. Multiple surface treatment techniques have been reported that enable this orientation including surface treatment with alkyl chlorosilanes [2, 3], chemical patterning [4-6], and polymer “brushes” [7-10]. However, control over feature size and orientation is still lacking. What is needed is a method which provides a large process latitude in the necessary control over feature orientation.
SUMMARY OF THE INVENTION
The present invention relates to a method for the synthesis and utilization of random cross-linked substituted polystyrene copolymers as surface treatments (PXSTs) for control of the orientation of the physical features of a block copolymer deposited over the first copolymer. Such methods have many uses including multiple applications in the semiconductor industry including production of templates for nanoimprint lithography. A wide range of surface energies can be obtained from these materials, and the results show the PXSTs need not be constituted from the identical two monomers in the block copolymer (BC) to obtain a wide process latitude for perpendicular orientation.
In one embodiment, the invention relates to a method, comprising: a) providing: i) a crosslinkable polymer comprising first and second monomers, ii) a block copolymer comprising third and fourth monomers, wherein said third and fourth monomers are chemically different from said first and second monomers; b) coating a surface with said crosslinkable polymer to create a first film; c) treating said first film under conditions such that crosslinkable polymer is crosslinked; d) coating said first film with said block copolymer to create a second film, and e) treating said second film under conditions such that nanostructures form, wherein the shape (and/or orientation) of the nanostructures is controlled (at least in part) by the chemical nature of said first film (and in some embodiments, it is also controlled in part by film thickness). In one embodiment, the block copolymer forms cylindrical nanostructures, said cylindrical nanostructures being substantially vertically aligned with respect to the plane of the first film. In one embodiment, said coating of step b) comprises spin coating. In one embodiment, the thickness of said first film is greater than 5.5 nm and less than 30 nm. In one embodiment, the thickness of said first film is between 10 and 30 nm. In one embodiment, said thickness of said first film is between 15 and 20 nm. In one embodiment, said crosslinkable polymer comprises an azido group on said first or second monomer (although other crosslinkable groups are used in other embodiments). In one embodiment, the PXST can contain one or several comonomers, the comonomers need not be those that are used to produce the block copolymer. In one embodiment, said treating of said first film in step c) comprises heating. Alternatively said treating comprises treating with light. Furthermore, in one embodiment said treating comprises light and heat. In one embodiment, said third monomer is styrene and said block copolymer comprises polystyrene. In one embodiment, said block copolymer is a polystyrene-block-poly(methyl methacrylate) copolymer. In one embodiment, said coating of said first film in step d) comprises spin coating. In one embodiment, wherein the thickness of said second film is between 10 and 100 nm. In one embodiment, said thickness of said second film is between 20 and 70 nm. In one embodiment, the treating of step e) comprises heating (e.g. under vacuum) so that the film is annealed. In one embodiment, the nanostructures are less than 100 nm in height.
In further embodiments, the invention relates to a composition, comprising a second polymer film coated on a first polymer film, said first polymer film comprising first and second monomers, said second polymer film comprising third and fourth monomers, wherein said third and fourth monomers are chemically different from said first and second monomers. In one embodiment, said second film comprises physical structures on a nanometer scale or “nanostructures”, said physical structures controlled by the chemical nature of said first film. In one embodiment, said second film comprises cylindrical nanostructures, said cylindrical nanostructures being substantially vertically aligned with respect to the plane of the first film. In one embodiment, the nanostructures are less than 100 nm in height (and more typically between 20 nm and 70 nm in height).
In one embodiment, said second film comprises a polystyrene-block-poly(methyl methacrylate) copolymer. In one embodiment, said first polymer film is coated on a surface. In one embodiment, said first polymer film is crosslinked. In one embodiment of the composition, the thickness of said first film is between 10 and 30 nm. In other embodiments, said thickness of said first film is between 15 and 20 nm. In one embodiment, the thickness of said second film is between 10 and 100 nm. In other embodiments, said thickness of said second film is between 20 and 70 nm.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures.
FIG. 1 shows the synthesis of poly(styrene-b-methyl methacrylate) (PS-b-PMMA). PS-b-PMMA was anionically synthesized via standard Schienk line techniques [11, 12].
FIG. 2 shows the Refractive Index detector response from a Gel Permeation Chromatography (RI GPC) of PS-b-PMMA.
FIG. 3 shows the of a family of polymers with different surface energies made by polymerization of monomers having a variety of different substituents. The characterization of P(SR)-r-P(SBnAz) and the impact of the various substituents are shown in Table 1.
FIG. 4 shows the surface energies of PXSTs where R=tBu, Cl, Me, H, and Br (blue), homopolymers (red), and wafer (grey).
FIG. 5A-D show an atomic force microscopy (AMF) phase images of PS-b-PMMA on PXST where (R═Br). FIG. 5A shows an atomic force microscopy (AMF) phase image of PS-b-PMMA on PXST where R═Br with a 23 nm process window. FIG. 5B shows an atomic force microscopy (AMF) phase image of PS-b-PMMA on PXST where R═Br with a 30 nm process window. FIG. 5C shows an atomic force microscopy (AMF) phase image of PS-b-PMMA on PXST where R═Br with a 36 nm process window. FIG. 5D shows an atomic force microscopy (AMF) phase image of PS-b-PMMA on PXST where R═Br with a 41 nm process window.
FIG. 6 is a schematic which shows the difference between homopolymers, random polymers and block polymers.
DEFINITIONS
To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims.
The present invention also contemplates styrene “derivatives” where the basic styrene structure is modified, e.g. by adding substituents to the ring (but preferably maintaining the vinyl group for polymerization). Derivatives can be, for example, hydroxy-derivatives, oxo-derivatives or halo-derivatives. As used herein, “hydrogen” means —H; “hydroxy” means —OH; “oxo” means ═O; “halo” means independently —F, —Cl, —Br or —I.
In addition, atoms making up the compounds of the present invention are intended to include all isotopic forms of such atoms. Isotopes, as used herein, include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium, and isotopes of carbon include 13 C and 14 C. Similarly, it is contemplated that one or more carbon atom(s) of a compound of the present invention may be replaced by a silicon atom(s). Furthermore, it is contemplated that one or more oxygen atom(s) of a compound of the present invention may be replaced by a sulfur or selenium atom(s).
Styrene is represented by the following structure:
1-(chloromethyl)-4-vinylbenzene is represented by the following structure:
P-methylstyrene is an example of a styrene derivative and is represented by the following structure:
P-chlorostyrene is another example of a styrene haloderivative and is represented by the following structure:
It is desired that the second film deposited over the first film develop “physical features on a nanometer scale,” “nanofeatures” or “nanostructures” with controlled orientation. These physical features have shapes and thicknesses. For example, various structures can be formed by components of a block copolymer, such as vertical lamellae, in-plane cylinders, and vertical cylinders, and may depend on surface energies and film thickness. In a preferred embodiment, the second film develops cylindrical nanostructures, said cylindrical structures being substantially vertically aligned with respect to the plane of the first film. Orientation of structures in regions or domains at the nanometer level (i.e. “microdomains” or “nanodomains”) may be controlled to be approximately uniform. The methods described herein can generate structures with the desired size, shape, orientation, and periodicity. Thereafter, in one embodiment, these nanostructures may be etched or otherwise further treated.
DETAILED DESCRIPTION OF THE INVENTION
Surface Energies of PXSTs. In the course of our efforts to employ non-traditional monomers for BCs, we became interested in the effect of surface energy on BC orientation. Films thicker than 15 nm of polymer 3 ( FIG. 3 ) were spin-coated, heated to cross-link through the azide functionality, and thoroughly rinsed to remove any non-cross-linked materials. Surface energies of these films were obtained by goniometry with water, glycerol, and diiodomethane contact angles. Several measurements were made over the entire wafer, and the error was consistently +/−2 dyne/cm. FIG. 4 displays these data and shows that the substituents affect the surface energy of the film. Additionally, the surface energies of non-cross-linked homopolymer films of PS and PMMA and a wafer cleaned with piranha were measured, and these values are consistent with the literature [2, 13].
In one embodiments, the invention relates to the PS-b-PMMA films of various thicknesses were coated on the PXSTs. These were annealed and investigated by AFM. The AFM images display very different process windows for perpendicular orientation of the PXSTs. The Cl-substituted PXST resulted in perpendicular cylinders for block film thicknesses of 30 to 35 nm, and the PXST with a Br substituent had a process window from 23 to 41 nm ( FIG. 5A-D ). These process window results are similar to other polymeric surface treatments reported by Nealey [14] and Hawker and Russell [10, 15, 16]. This leads to the conclusion that a PXST need not consist of the same monomers as the BC being coated.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
It is not intended that the present invention be limited to specific block polymers. However, to illustrate the invention, examples of various copolymers are provided. In one embodiment, the invention relates to the synthesis of the polystyrene-containing block copolymer “PS-b-PMMA.” PS-b-PMMA was anionically synthesized via standard Schlenk line techniques ( FIG. 1 ) [11, 12]. 1 H-NMR showed the resulting polymer is 31 mol % PMMA, which corresponds to a volume fraction of 0.27 [17]. This is within the range for cylinder morphology [1]. The Mn of the PS aliquot was 45.8 kDa with a PDI of 1.18; the total molecular weight was 65.6 kDa with a PDI of 1.18. FIG. 2 shows GPC chromatograms of the PS aliquot and PS-b-PMMA.
In one embodiment, the invention relates to the synthesis of P(SR)-r-P(SBnAz). In a procedure similar to Hawker et al. [9], several commercially available styrene derivatives were radically copolymerized with vinyl benzyl chloride to investigate the role of substituents on the surface energy of PS. Upon isolation of 2, nucleophilic substitution of the chloride with azide ion led to cross-linkable polymers 3 ( FIG. 3 ). The presence of the azide was confirmed by IR, and the resulting polymers are described in Table 1. Table 1 shows the characterization of P(SR)-r-P(SBnAz) (shown in FIG. 3 ) with different substituents at the R position.
General Materials and Methods
Materials.
All reagents were purchased from Sigma-Aldrich Chemical Co. and used without further purification unless otherwise noted. THF was purchased from JT Baker. 100 mm silicon wafers were purchased from Silicon Quest International.
Instrumentation.
All 1 H and 13 C NMR spectra were recorded on a Varian Unity Plus 400 MHz instrument. All chemical shifts are reported in ppm downfield from TMS using the residual protonated solvent as an internal standard (CDCl 3 , 1 H 7.26 ppm and 13 C 77.0 ppm). Molecular weight and polydispersity data were measured using an Agilent 1100 Series Isopump and Autosampler and a Viscotek Model 302 TETRA Detector Platform with 3 I-series Mixed Bed High MW columns against polystyrene standards. Polymer solutions were filtered with 0.20 μm PTFE filters prior to spin coating. Films were spin coated and baked on a Brewer CEE 100CB Spincoater & Hotplate. Film thicknesses were determined with a J.A. Woollam Co, Inc. VB 400 VASE Ellipsometer using wavelengths from 382 to 984 nm with a 70° angle of incidence. Contact angles were measured with a Ramé-Hart, inc. NRL C.A. Goniometer (Model #100-00). A Heraeus Vacutherm Type VT 6060 P from Kendro was used to thermally anneal the films under reduced pressure. A Digital Instruments Dimension 3100 atomic force microscope with NCHR Pointprobe® Non-Contact Mode tips with a force constant of 42 N/m was used to collect AFM images.
EXAMPLE 1
Synthesis of poly(styrene-b-methyl methacrylate) (PS-b-PMMA (1))
PS-b-PMMA was synthesized as previously reported by sequential anionic polymerization of styrene and methyl methacrylate in THF at −78° C. under Ar atmosphere via standard Schlenk line techniques [11]. The initiator was sec-BuLi; diphenyl ethylene was used to properly initiate MMA, and LiCl was added to suppress side reactions during MMA propagation[12].
EXAMPLE 2
P(SR)-r-P(SBnAz) (3)
In a procedure adopted from Hawker et al. [9], a substituted styrene (20 mmol) and vinyl benzyl chloride (0.62 mmol) were radically copolymerized in refluxing THF (20 mL) for 48 h with enough AIBN to obtain a theoretical MW of 25 kDa. Once polymer 2 was precipitated in 0° C. MeOH, filtered, and dried in vacuo, the mol ratio of substituted styrene to vinyl benzyl chloride was determined by 1H-NMR. Taking into account this ratio and the Mn as determined by GPC, polymer 2 (1.0 g) and sodium azide (3 equiv/BnCl) were dissolved in DMF (20 mL) and stirred overnight at room temperature (rt). The polymer was precipitated in MeOH, filtered, redissolved in THF (10 mL), and stirred with H 2 O (1 mL) to remove any unreacted salts. Finally, the polymer was isolated by precipitation in 0° C. MeOH, filtered, and dried in vacuo to yield white powder 3. Typical yields over these two steps were 50%; IR (KBr) 2100 cm-1. Complete characterization is shown in Table 1.
EXAMPLE 3
Surface Treatment with PXSTs
A film of P(SR)-r-P(SBnAz) was spin coated from a 1.0 wt % solution in toluene at 3770 rpm for 30 sec onto a wafer that had been rinsed with IPA and acetone. The wafer was immediately baked at 250° C. for 5 min to cross-link the film. The wafer was then submerged in toluene for 2 min, blown dry, submerged again for 2 min, and blown dry. Typical film thicknesses as determined by ellipsometry were 15-20 nm.
EXAMPLE 4
Surface Energy Measurements by Goniometry
Contact angles were measured with H 2 O, diiodomethane, and glycerol, and analyzed via the Young-Dupre equation (Eq 1) and the Acid-Base Surface Energy Model (Eq 2) [18].
γ SV =γ SL +γ LV cos θ−π eq Eq 1
γ SV is the surface energy of the solid-vapor interface, γ SL is the interfacial energy of the solid-liquid interface, γ LV is the surface tension of the fluid, θ is the angle between the solid and liquid, and π eq is the equilibrium spreading pressure, which is approximately zero for polymeric surfaces.
γ 12 =γ 12 LW +γ 12 AB Eq 2
−γ 2 cos θ=γ 2 LW −2(γ 1 LW γ 2 LW ) 1/2 +2[(γ 2 P+ γ 2 P− ) 1/2 −(γ 1 P+ γ 2 P− ) 1/2 −(γ 1 P− γ 2 P+ ) 1/2 ] Eq 3
Briefly, Eq 2 describes the interfacial energy between two components (γ 12 ) as the sum of the dispersion (γ 12 LW ) and acid-base components (γ 12 AB ). Eq 3 relates the surface energy of the film and cosine of the contact angle (−γ 2 cos θ) to the dispersion (γ 2 LW ), Lewis acid (γ 2 P+ ), and Lewis base components (γ 2 P− ). Using literature values for H 2 O, diiodomethane, and glycerol, a system of equations was solved to obtain the surface energy of the PXST films.
Spin Coating and Annealing.
A clean, surface-treated wafer was spin coated with a film of PS-b-PMMA from toluene at various speeds and concentrations to give 20-70 nm films as determined by ellipsometry. Once cast, the wafer shards were annealed at 170° C. under reduced pressure for 12-18 h.
REFERENCES
1. Bates, F. S., and Fredrickson, G. H. (1999) Block Copolymers—Designer Soft Materials Phys. Today 52, 32-38.
2. Peters, R. D., Yang, X. M., Kim, T. K., Sohn, B. H., and Nealey, P. F. (2000) Using Self-Assembled Monolayers Exposed to X-Rays to Control the Wetting Behavior of Thin Films of Diblock Copolymers, Langmuir 16, 4625-4631.
3. Niemz, A., Bandyopadhyay, K., Tan, E., Cha, K., and Baker, S. M. (2006) Fabrication of Nanoporous Templates from Diblock Copolymer Thin Films on Alkylchlorosilane-Neutralized Surfaces, Langmuir 22, 11092-11096.
4. Ruiz, R., Kang, H., Detcheverry, F. A., Dobisz, E., Kercher, D. S., Albrecht, T. R., de Pablo, J. J., and Nealey, P. F. (2008) Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly, Science 321, 936-939.
5. Stoykovich, M. P., Müller, M., Kim, S. O., Solak, H. H., Edwards, E. W., Pablo, J. J. d., and Nealey, P. F. (2005) Directed Assembly of Block Copolymer Blends into Nonregular Device-Oriented Structures, Science 5727, 1442-1446.
6. Kim, S. O., Kim, B. H., Kim, K., Koo, C. M., Stoykovich, M. P., Nealey, P. F., and Solak, H. H. (2006) Defect Structure in Thin Films of a Lamellar Block Copolymer Self-Assembled on Neutral Homogeneous and Chemically Nanopattemed Surfaces, Macromolecules 39, 5466-5470.
7. Mansky, P., Liu, Y., Huang, E., Russell, T. P., and Hawker, C. (1997) Controlling Polymer-Surface Interactions with Random Copolymer Brushes Science 275, 1454-1457.
8. Han, E., In, I., Park, S.-M., La, Y.-H., Wang, Y, Nealey, P. F., and Gopalan, P. (2007) Photopattemable Imaging Layers for Controlling Block Copolymer Microdomain Orientation, Adv. Mater. 19, 4448-4452.
9. Bang, J., Bae, J., Löwenhielm, P., Spiessberger, C., Given-Beck, S. A., Russell, T. P., and Hawker, C. J. (2007) Facile Routes to Patterned Surface Neutralization Layers for Block Copolymer Lithography, Adv. Mater. 19, 4552-4557.
10. Ham, S., Shin, C., Kim, E., Ryu, D. Y., Jeong, U., Russell, T. P., and Hawker, C. J. (2008) Microdomain Orientation of Ps-B-Pmma by Controlled Interfacial Interactions, Macromolecules 41, 6431-6437.
11. Uhrig, D., and Mays, J. W. (2005) Experimental Techniques in High-Vacuum Anionic Polymerization, J. Polym. Sci. A. 43, 6179-6222.
12. Allen, R. D., Long, T. E., and McGrath, J. E. (1986) Preparation of High Purity, Anionic Polymerization Grade Alkyl Methacrylate Monomers Polym. Bull. 15, 127-134.
13. Jung, Y. S., and Ross, C. A. (2007) Orientation-Controlled Self-Assembled Nanolithography Using a Polystyreneâ^’ Polydimethylsiloxane Block Copolymer, Nano Lett. 7, 2046-2050.
14. Han, E., Stuen, K. O., Leolukman, M., Liu, C.-C., Nealey, P. F., and Gopalan, P. (2009) Perpendicular Orientation of Domains in Cylinder-Forming Block Copolymer Thick Films by Controlled Interfacial Interactions, Macromolecules 42, 4896-4901.
15. Ryu, D. Y, Wang, J.-Y., Lavery, K. A., Drockenmuller, E., Satija, S. K., Hawker, C. J., and Russell, T. P. (2007) Surface Modification with Cross-Linked Random Copolymers:Â ‰ Minimum Effective Thickness, Macromolecules 40, 4296-4300.
16. Ryu, D. Y., Ham, S., Kim, E., Jeong, U., Hawker, C. J., and Russell, T. P. (2009) Cylindrical Microdomain Orientation of Ps-B-Pmma on the Balanced Interfacial Interactions: Composition Effect of Block Copolymers, Macromolecules 42, 4902-4906.
17. Fetters, L. J., Lohse, D. J., Richter, D., Witten, T. A., and Zirkel, A. (1994) Connection between Polymer Molecular Weight, Density, Chain Dimensions, and Melt Viscoelastic Properties, Macromolecules 27, 4639-4647.
18. Van Oss, C. J., Good, R. J., and Chaudhury, M. K. (1988) Additive and Nonadditive Surface Tension Components and the Interpretation of Contact Angles, Langmuir 4, 884-891.
TABLE 1
% BnAz
R
M w (kDa)
M n (kDa)
PDI
( 1 H-NMR)
H
26.6
15.5
1.71
7.7
Cl
30.2
17.3
1.75
8.9
Br
38.1
19.5
1.95
5.0
Me
36.6
21.8
1.68
8.1
tBu
32.0
17.6
1.81
7.0
|
The present invention relates to a method the synthesis and utilization of random, cross-linked, substituted polystyrene copolymers as polymeric cross-linked surface treatments (PXSTs) to control the orientation of physical features of a block copolymer deposited over the first copolymer. Such methods have many uses including multiple applications in the semiconductor industry including production of templates for nanoimprint lithography.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to a safe ice rink for use in areas of water adjacent to shore in natural bodies of water or in fabricated aquatic bodies, such as reflecting or swimming pools. The invention consists of a platform which floats on the surface of such body of water, the platform supporting a separate shallow water containment structure which is filled with water. The water in the platform containment structure can be frozen either by natural (low ambient atmospheric temperatures) or by artificial means (refrigeration coils). The floating platform can include multiple units seasonally assembled and disassembled and stored.
SUMMARY OF THE INVENTION
According to the practice of this invention, swimming pools of hotels, marinas, health clubs and the like, as well as private homes can be converted, during the winter season, to safe ice skating rinks or for other winter sports such as curling. This is accomplished by use of a floating platform which supports a layer of ice. The ice may be reinforced with metal mesh to provide additional safety by increasing the tensile strength of the ice layer and further to enhance freezing of the water. It is generally the practice to maintain fabricated (home, motel, etc.) swimming pools filled with water in the winter season, to thereby provide lateral support to the pool walls which would otherwise be cracked due to lateral earth pressure and/or freezing. It is also the practice to cover such pools with sheets of polyethylene or similar sheet material to prevent leaves and dirt from entering the pools in the winter season. These pool covers also help prevent small children and house pets from injury due to falling in the pools.
Certain embodiments of this invention function not only for the use of the ice for winter sports, but also provide a cover to keep out dirt and support the weight of adults and large house pets and provide a barrier to accidental immersion.
The following elements in combination define the invention. (1) A pool or other aquatic body in which the floating skating rink floats. (2) Floats, typically made of styrofoam or similar lightweight, water tight materials, pneumatic tubes, spheres or buoyant bodies such as rigid or semirigid pontoons. (3) A platform consisting of either the top surface of the float elements or a material such as plywood, fiberglass, semi or rigid plastic supported by the float material. (4) A containment system for the water to be frozen, consisting of a peripheral curb and a water tight base or water tight blanket or sheet such as the polyethylene sheets typically used as linings in pools or as boat covers. (5) A system for containing the float elements or of fastening prefabricated float units together to provide uniform support to the platform underlying the ice. This system may consist of mechanical means such as bolting together the frames of adjacent float units; encirclement with rope, wire rope or cable tensioned to hold all units in position; floatation blocks penetrated with horizontal lateral and transverse holes through which tensioning strands of rope, wire tope, cable or rods are placed and tensioned against exterior frame units. Other methods such as a horizontal grillage may be employed to secure and hold the floatation units in the desired position. The above five elements are essential to this invention. The second, third and fourth elements may be combined into a single unit.
Additionally, the following elements may optionally be used in the ice rink: (1) Ice making equipment such as is used for indoor arenas or for portable rinks such as is used with traveling ice shows. (2) Metal mats made of crossed wires or rods; in effect as safety net which has the dual purpose of strengthening the ice and preventing cracks, and also increases the rate of freezing the water on the platform, turning it into ice in less time and more efficiently. (3) Stiffening trusses or frames for large installations or where the skating rink is to be located over moving or tidal water. (4) A guide for positioning the ice rink a few inches from pool walls, or an anchoring system for when the ice rink is to be located over moving or tidal water. (5) An air bubbling system to prevent the formation of ice between the pool walls and the floats is desirable in climatic areas where natural freezing of ponded water frequently exceeds three inches. (6) A ramp or stair is provided when the floating ice skating rink is located over tidal or flowing water. (7) Guard rails on the perimeter of all ice rinks that do not fully occupy a pool to within four inches of all adjacent walls and for all pools over open water.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially broken perspective view of a rectangular embodiment of the floating platform ice skating rink of this invention.
FIG. 2 is a plan view of the rink of FIG. 1.
FIG. 3 is a partially broken perspective view of a typical floatation block which forms a part of the rink and through which holes or tubes have been placed to receive tensioning strands.
FIG. 4 is a cross sectional view of a typical floatation block showing details of the tensioning system and end frame and anchorage of the tensioning strands.
FIG. 5 is a partially broken perspective view of a section of an ice rink for a circular, elliptical or other convexly curved rink.
FIG. 6 is a partial perspective view of a tension cable and surrounding tube of FIG. 5.
FIG. 7 is a cross sectional view of a circular ice rink similar to that of FIG. 5.
FIG. 8 is a partially broken perspective view of a floatation unit.
FIG. 9 is a partial sectional view taken along two coupled units of FIG. 8.
FIG. 10 is a partially broken perspective view of a tubular blanket pneumatic flotation unit.
FIG. 11 is a cross-sectional view of an ice rink using blanket type pneumatic tubular elements of FIG. 10 for floatation.
FIG. 12 is a side elevational view of a truss that can be incorporated with the skating rink of this invention to provide greater support and stiffness.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, the ice rink of this invention is shown. A layer of ice 1 is bordered by a peripheral water/ice retaining curb 2 whose height, measured vertically from the bottom of the ice, is greater than the depth of the ice layer. A water impervious sheet 3 of polyethylene or rubber impregnated woven material rests on the top surface of a rigid sheet platform 4, typically of plywood, with ice layer 1 resting on sheet 3. The platform and curb define a shallow container. A continuous serpentine refrigeration tube 5, mounted on wooden pad supports 13 on sheet 3 becomes embedded in the ice after freezing of the water. A plurality of flotation blocks 6 are pierced by a plurality of orthogonally running tension cables or tendons 7, the tendons passing through holes or tubes 10 in the blocks. Each block receives two or more tendons. Exterior frame panels 8, fashioned typically of wood, surround the rink and carry tendon anchorages 9 of known construction. A layer of wire reinforcement 14 is positioned on top of refrigerant tube 5 (see FIG. 7) and functions to both speed up freezing and strengthen the ice.
FIG. 2 illustrates the relation between floatation blocks 6, tendons or cables 7, panels 8 and tendon anchorages 9. The flotation blocks are illustrated as rectangular, although they may be square in plan view.
FIG. 3 illustrates a typical block 6 having tubes 10 passing therethrough. Tubes 10 of any block are aligned with corresponding holes in the other blocks to form continuous passages for receiving respective tendons 7.
FIG. 4 illustrates a cross-section of a typical block near the periphery of the rink, showing exterior frame panels 8 and tendon attachment members 9. The latter are defined, conventionally, by an apertured block of wood with a split frusto conical wedge member for frictionally engaging the periphery of a typical flexible tendon or cable 7. It will be understood that the cable anchorage 9 may assume any of a number of known forms and that tendons 7 may be flexible, as cable, or rigid, as with metal bars.
Referring now to FIGS. 5 and 6 of the drawings, a modified form of the ice rink is illustrated. Flotation elements 6 are arcuate in form, with the radially innermost elements pie shaped. The outer periphery of each radially distinct group of flotation elements is provided with tension cables or tendons 7 running within associated tubes 10, as shown FIG. 6.
Turning now to FIG. 7, a partial transverse cross-section of the ice rink shown at FIG. 5 is illustrated, without exterior frame panels 8 and tension with cables 7. Curb 2 may be of wood or plastic or a tube filled with sand for example, but should not be a pneumatic tube or a water filled tube subject to puncture by ice skates. Further, reinforcing wire grid 14 and refrigerant tube 5 are usually both made of aluminum to eliminate electrolysis. If a particular environment for the ice rink does not require artificial refrigeration, then the refrigerant tubes 5 may be omitted and reinforcing grid 14 may be of steel rods, glass fiber or other material with a high modulus of elasticity and will not become brittle at temperatures down to -20° F. (-28° C). The numeral 15 denotes the maximum level of water which will form ice layer 1. Normally, a minimum level of 1 inch over the reinforcing wire grid 14 is required, but the thickness may be greater and almost up to the top of curb 2 as indicated. Typically, the thickness of ice layer 1 will be from 3 to 5 inches. Referring to FIG. 8, another embodiment of a float for the ice rink is illustrated. The floats are fashioned from a plurality of sections 16. Each section is generally rectangular shape but can be truncated triangular as shown or of any shape and includes wooden frame members 17 which form the sides and cross frames and which divides the interior of each section into cells. Each cell contains flotation material 19 which may assume the form of blocks of styrofoam, pneumatic balls in plastic bags or other flotation elements. The top of each section 16 is closed by a rigid panel 18. The sections are provided with openings 21 which accommodate elongated, flat and apertured coupling brackets 22. FIG. 9 illustrates bolts 20 passing through aligned openings in the sides of adjacent flotation elements 16. Brackets 22 also couple these elements together.
FIG. 10 illustrates a flotation unit 23 similar to an air mattress used by campers and body surfers. This element consists of a series of longitudinal tubes 24 which can be individually inflated and deflated and are encased in a cover of fabric 25. The periphery of the unit includes a plurality of eyelets 26 for fasteners securing abutting flotation units together.
FIG. 11, an ice rink as shown with flotation units 23 of FIG. 10. Several flotation units are secured together by means of fasteners in eyelets 26. Overlying flotation units 23 is a platform of plywood 4 upon which is set a curb 2, the plywood platform is covered with a water retention sheet 3 of polyethylene. Wooden blocks 13 lie on top of sheet 4 and wire grid 14 is placed on top of the wooden blocks. Water in a typical concrete swimming pool receives the ice rink. A bubbler tube insures an ice free pool periphery. The ice rink of FIG. 11 may or may not require artificial refrigeration, such as coil 5 of FIG. 1. One advantage of the embodiment of FIG. 11 is that without rigid flotation elements, storage requirements of the skating rink during summer months will be appreciably less.
FIG. 12 illustrates frame or lattice 27 formed by coupled pipe trusses. Again, a layer of ice 1 has wire grid elements 14 embedded therein. A plywood sheet 4 is provided at regular intervals with apertures, with one end of a typical vertical pipe 30 extending through a respective aperture. Washers 34 are positioned on the top underside of sheet 4 and function to seal the annular space around pipes 30 as they pass through the plywood. Flotation blocks 6 are located beneath the plywood for flotation of the entire structure. Diagonal pipes 29 are secured to the vertically extending pipes by coupling elements 33, with sleeve coupling members 32 securing horizontally running truss members 28 together. The weight of the truss, the ice and the other elements will determine the size and character of flotation blocks 6. The assembly illustrated in FIG. 12 is shown without refrigeration elements, although it is obvious that they may be employed, as with the embodiment of FIG. 1. The entire structure is adapted to float.
|
An ice rink formed from a shallow container having flotation elements on its bottom. The container is filled with water to such an extent that when frozen, the resultant ice layer will be suitable for ice skating. The bottom of the container may be provided with a refrigerant coil to freeze the water in the container. The specific gravity of the rink is less than unity to permit is use in a swimming pool.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims a benefit of priority to Japanese Application No. 2002-262311 filed on Sep. 9, 2002, now abandoned, and Japanese Application No. 2003-84232 filed on Mar. 26, 2003, currently pending, and a continuation-in part of U.S. application Ser. No. 10/664,266 filed Sep. 17, 2003, currently pending, the contents of these applications are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Guardrails are installed along roadsides in order to prevent cars from jumping into oncoming lanes, sidewalks and rolling down steep embankments. Collision with a guardrail normally occurs when a driver looses control of a vehicle through inattention, poor road conditions or collision with another vehicle.
[0003] One type of guardrail generally consists of a long sheet fence, a support post, and a rigid mid-filler attachment connected between the first two components. Such a guardrail can be made more rigid only by narrowing the span of the support posts. This type of guardrail absorbs collision energy mainly by deformation of the fence or support post.
[0004] Japanese Patent No. 6-280222 modifies an ordinary guardrail to include a modified support post with an elastically recoverable elastic body. Japanese Patent No. 7-150529 discloses a guardrail having a housing with several pipes connected into the cushion cover and that covers the support post. Japanese Patent No. 10-18257 discloses a guardrail made with components having different rigidities, a rigid face to end portion and a relatively brittle face to others.
SUMMARY OF THE INVENTION
[0005] The invention is a shock-absorbing device for use in a guardrail that can be situated, for example, at a median or parapet of a bridge. This device absorbs the shock of a car collision and prevents components of the guardrail, such as support posts and parapets of a bridge, from collapsing.
[0006] One type of guardrail that can reduce the shock of impact transmitted to its support post by reduces the speed of a colliding car by absorbing shock via deformation of the rail or collapse of its support post. Using more support posts increases the rigidity of the guardrail's entire structure, but the support posts do not have the capability of absorbing much shock.
[0007] If more support posts are to be employed, however, extra area for the collapse of the support post is required to allow for an appropriate guardrail area. Failure to provide this area may endanger cars driving on the opposite side of the roadway or pedestrians walking on the outside of the guardrail.
[0008] If the collision energy is excessive, collapse of the support post may increase the possibility of the colliding car bursting through the guardrail and causing further damage to property and/or individuals. If the guardrail collapses, the colliding car may exit the travel lane making it difficult to bring the car safely back into the travel lane.
[0009] When repairing a bent support post by bending it in an opposite direction of the bend to bring it back to a vertical position often results in a break at the bend. Metal fatigue is often the cause. This necessitates replacement of the damaged foundation and the need to mount a new support post, which is inconvenient and costly when combined with replacement of any breakage in the guardrail. If the damaged support post is left in a state of disrepair, it can become an obstacle for the passage of vehicles and pedestrians.
[0010] One way these problems are addressed is by increasing the rigidity of the support post to reduce the amount of deformation. The rigid guardrail, however, loses the capability of absorbing enough collision energy and allows the transmission of collision shock. This reduces the safety of the occupants of car that collides with the rigid guardrail.
[0011] When the support post has an elastically recoverable elastic body, it has the ability to absorb shock by reducing the speed of a colliding car before it collides into the support post. The elastically recoverable body, however, may cause severe secondary injuries and damage due to the elastic restoring force that can transmit elastic force to the occupants of the colliding car after the car has come to a stop.
[0012] The present invention solves the above-mentioned problems by providing a shock-absorbing guardrail device that has a simple structure. The structure can prevent the support post from collapsing by absorbing the shock caused by the collision of a car.
[0013] A further goal is to reduce the necessity of repairing damaged foundations and the need for new support posts during reconstruction of the guardrail. This invention utilizes a mid-filler attachment that undergoes an irreversible deformation during collision. The attachment has either an ohm-shaped cross-section or a vertically-opened, pipe-shaped cross section attached to a support post or structure. The guard fence attaches to and bridges each support post by connection parts to absorb colliding energy of a car, which overcomes the problems mentioned above.
[0014] In one embodiment, irreversible deformation of the mid-filler attachment with either the ohm-shaped cross section or the vertically-opened, pipe-figured cross-section and is utilized and connected to a construct. The back of the guard fence faces and is attached to, the surface of the construct by connection parts and absorbs the collision energy of the car, which overcomes the above-mentioned problems.
[0015] A further embodiment utilizes a shock-absorbing pipe or shock-absorbing resin along with the shock-absorbing elements mentioned above.
[0016] Another embodiment involves attaching the shock-absorbing guardrail device, discussed above, onto a construct located at a hydrant, a semaphoric pole, a bifurcation (diverging point), an anti-collision section, and a sectional wall.
[0017] A further embodiment utilizes a mid-filler attachment characterized by its cross section comprising a layered, laminated, or stratified ohm figure in place of the mid-filler attachment or pipe discussed above.
[0018] The above-described shock-absorbing guardrail device can absorb collision energy of a car by an irreversible deformation of a mid-filler attachment and deformation of the guardrail itself. The deformation absorbs the impact of the collision transmitted to the support post by reducing the speed of a colliding car.
[0019] The shock-absorbing guardrail device does not employ an elastic body and prevents transmission of elastic force to the occupants of a colliding car when stopped. The shock-absorbing guardrail device will not cause secondary injury or damage caused by the elastic restoring force as is common with guardrails having elastic bodies.
[0020] The shock-absorbing guardrail device has a simple structure that is easy to install and remove, even after an impact by a vehicle. The device has the capability of preventing the support post from collapsing by absorbing shock through the deformation of a collision energy absorbing pipe or mid-filler attachment. The substantial absorption of crash energy reduces the necessity of repairing damaged post foundations and setting up new support posts during repairs, which therefore reduces costs.
[0021] When an excessive load is applied to the guardrail as with a high speed collision or collision with a vehicle having excessive weight, the collision energy can be absorbed by deformation or collapse of the support posts that enables the car to safely return to the travel lane so as to secure the safety of the cars occupants.
[0022] This shock-absorbing device can be installed on hydrants, semaphoric poles, bifurcations (diverging point), column-shaped safety drums located at bifurcations, anti-collision sections in front of toll booths, and sectional building blocks (i.e. walls at parking lots, concrete walls) and so on. The shock-absorbing device can be attached to those structures and provide the same benefit as explained above by covering the surface of the structure either partially or fully with the device.
BRIEF DESCRIPTION OF THE FIGURES
[0023] [0023]FIG. 1( a ) shows side view of one embodiment shock-absorbing device. (Guard fence is shown as shape of cross section.)
[0024] [0024]FIG. 1( b ) is a cross-sectional view of the main portion of the shock-absorbing device.
[0025] [0025]FIG. 2 is a cross-sectional view showing one embodiment of the shock-absorbing device in a squashed condition after a collision.
[0026] [0026]FIG. 3 is a cross-sectional view of one embodiment of the shock-absorbing device.
[0027] [0027]FIG. 4 is a cross-sectional view of a main part of another embodiment of the shock-absorbing device.
[0028] [0028]FIG. 5 is a cross-sectional view of a main part of a mid-filler attachment embodiment.
[0029] [0029]FIG. 6 is a graph showing the results of static experimentation of one embodiment of the shock-absorbing device wherein the horizontal axis represents change in vertical size (mm), and the vertical axis represents a load (kg) placed on a top surface.
[0030] [0030]FIG. 7( a ) is a side view of an ordinary guardrail. The guard fence is shown in cross section.
[0031] [0031]FIG. 7( b ) shows a cross-sectional view of a main part of an ordinary guardrail.
DETAILED DESCRIPTION OF THE INVENTION
[0032] [0032]FIG. 1( a ) is a side view of one possible embodiment of the shock-absorbing device shown generally as 10 . A guard fence 14 is shown in cross section. FIG. 1( b ) is a cross-sectional view of the main portion of the shock-absorbing device 10 .
[0033] Shock-absorbing device 10 comprises support post 12 that is erected parallel to the roadside with certain span. A back surface 14 a of guard fence 14 back 14 a is attached to support post 12 and bridges each support post 12 . A mid-filler attachment 16 is installed in-between each support post 12 and guard fence 14 and acts as a connecting element between them. Connector 17 , which can be a bolt, rivet, screw or other equivalent fastener, connects support post 12 and mid-filler attachment 16 . When connector 17 is a bolt or other releasable type of equipment, it allows for faster repair and installation. Guard fence connector 18 attaches guard fence 14 to mid-filler attachment 16 .
[0034] As shown in FIG. 1( b ), an elliptical Mid-filler attachment 16 a conforms to the shape of an ellipse.
[0035] Support post 12 can be a rust proofed steel product or other material having equivalent properties of strength and is affixed on the roadside by mounting a lower portion into a foundation such as concrete. The support post 12 may also be attached at its lower portion to the foundation via bolting or other means of attachment.
[0036] In one potential embodiment, a through-Hole 17 is placed at an upper part of the support post 12 so that connector 17 can perforate support post 12 and connect support post 12 and mid-filler attachment 16 . Other means of mounting the mid filler attachment 16 to the support post 12 (not shown) can be accomplished without the perforation of support post 12 by the use of a U-bolt passing around the body of the post 12 or the use of a cap containing a perforation and connector 17 that could be mounted over the top of the support post 12 by such method as a friction fit to perform the identical function of attaching the mid-filler attachment 16 to the support post 12 . It should be understood that many other means of fastening the mid-filler attachment 16 to the support post 12 can also be envisioned by one skilled in the art to provide similar function.
[0037] Guard fence 14 may be a rust proofed steel product or a material having similar properties, having a flat or a contoured deck plate as displayed in FIG. 1( a ). One method of attaching guard fence 14 is by the placement of a through-hole 18 to receive fence connection parts 18 in order to affix mid-filler attachment 16 . Conversely, fence connector parts 18 could be welded or affixed to guard fence 14 so that a through-hole 18 could be omitted if desired. There are many possible methods of attaching guard fence 14 to incorporate the mid-filler attachment 16 between the support posts 12 .
[0038] In FIG. 3, the Mid-filler attachment 16 comprises a collision energy absorbing pipe 16 a (having a closed elliptical cross section that changes shape with irreversible deformation) and arm parts 16 b (which may be welded or otherwise affixed to the guard fence 14 side). A through-hole 19 may be placed on each of the arm parts 16 b at corresponding positions of through-Hole 18 a.
[0039] It should be understood and appreciated that the one possible embodiment described and explained above, is by way of illustration and not limitation. There are other obvious design changes that can be employed to accomplish the same ends.
[0040] [0040]FIG. 3 shows another embodiment of installing a collision energy absorbing pipe 16 a between the support post 12 and guard fence 14 . These elements are connected directly by connection parts 17 and connection parts 18 . (This is designated as shock-absorbing device 10 ′)
[0041] The material, size, and shape of the support post 12 , guard fence 14 , and mid-filler attachment 16 can be modified to direct a car that has collided with the guardrail to be brought safely back to the travel lane. The optimization of the cushioning performance influenced by the type of car, its speed at collision, its weight, angle of impact, etc.
[0042] When a car collides into a guardrail, made in accordance with the invention, it absorbs the energy of the moving car and irreversibly deforms the collision energy absorbing pipe 16 a . The absorption of energy results in a reduction of the speed of the colliding car. (See FIG. 2) Absorbing collision energy through deformation of the collision energy absorbing pipe 16 a reduces the likelihood of the support post 12 being bent. The remaining collision energy that is transmitted to support post 12 after deformation of the collision energy absorbing pipe 16 a reduces the possibility of collapsing the support post 12 during impact. The prevention of damage to the support post 12 will prevent the need for replacing the support post 12 or fixing damaged foundations thereby reducing the costs of maintaining and repairing the guardrail.
[0043] When an excessive load is applied such as that which occurs when a vehicle with excessive speed or excessive weight collides with the guardrail, the excess collision energy can be absorbed by deformation or collapse of the support posts 12 .
[0044] It should be understood that if the rigidity of the mid-filler attachment is either too small or too large, it cannot absorb the energy of the colliding car in some circumstances. This may reduce the safety of the occupants of the vehicle.
[0045] [0045]FIG. 4 shows a cross-sectional view of a main portion for a shock-absorbing device 20 . Shock-absorbing device 20 is similar to shock-absorbing device 10 except that the mid-filler attachment 26 has an ohm-shaped cross-section that is comprised of an integrated combination of a collision energy absorbing pipe 16 a and arm parts 16 b . The mid-filler attachment 26 may optionally contain the mid-filler attachment 16 a either within the center of the hollow of the mid-filler attachment 26 between the guard fence 14 and the mid-filler attachment 26 or positioned between the support post 12 or structure and the outside top of the mid-filler attachment 26 . Furthermore, the above combinations can include a shock absorbing resin within any hollow section between the back of the guard fence 14 and the support post 12 or structure.
[0046] The mid filler attachment 26 having the ohm-shaped cross-section has a body that is a portion of a radius of a circle or an ellipse that transitions into at least one integrated arm. The arm has an angle of about 5 to 90 degrees to that of the body. The mid-filler attachment 26 with a short length can be oriented in any direction and at least one of the integral arms is attached to the back of the guard fence 14 . The mid-filler attachment 26 can have a length similar to the diameter of the support post 12 or be oriented so that it can span the entire length of any portion thereof of the guard fence 14 .
[0047] Optionally the ohm-shaped mid-filler attachment 26 can have a means for propagating crash energy along the length of the ohm-shaped mid-filler attachment by providing a thicker area along the length of the mid-filler attachment that intersects with the point of attachment of the mid-filler attachment 26 to either the support post 12 or structure (not shown).
[0048] [0048]FIG. 5 shows a cross-sectional view of a shock-absorbing device 30 having at least two of the ohm-shaped mid-filler members comprising a large mid-filler member 36 and a small mid-filler member 26 . The small mid-filler member 26 can be arranged or positioned within the large mid-filler member 36 .
[0049] Materials, sizes, and shapes of ohm-shaped mid-filler attachments 26 and mid-filler attachments 36 can be changed to maximize the ability to bring a car safely back to the travel lane. The mid-filler attachment can be optimized for cushioning performance according to the kind of car, its speed at collision, its weight, etc.
[0050] Optionally, a shock-absorbing resin can be employed and installed within the collision energy absorbing pipe 16 , or the U-shaped portion of mid-filler attachment 26 or within the back portion of the guardrail 14 . The structure can be designed so that only the shock-absorbing resin changes shape or both the shock-absorbing resin and collision energy absorbing pipe or U shape portion of mid-filler attachment change shape. (No Figure shown).
[0051] This shock-absorbing device can be installed not only in the space between the support post 12 erected in line with the ground and guard fence and bridging several support posts, but also on hydrants, semaphoric poles, bifurcations (diverging point), column-shaped safety drums located at bifurcations, anti-collision sections in front of toll booths, and sectional building blocks such as walls at parking lots, concrete walls and so on. The shock-absorbing device can be attached to these structures and provide the same benefits as explained above by covering the surface either partially or fully with it.
[0052] Static experimentation was carried out to determine the static performance of the mid-filler attachment. Two kinds of mid-filler attachments were tested, a mid-filler attachment 26 (made of SS400 steel [Height: 50 mm], made by folding a plate having a thickness: 4.5 mm, and Width: 50 mm] into an ohm shape) and a mid-filler attachment 36 (made of SS400 steel [Height: 100 mm], made by folding a plate [Thickness: 4.5 mm, and Width: 50 mm] into an ohm shape) outside and a mid-filler attachment 26 inside. The attachments were examined by setting each attachment onto a base plate and applying a load (kg) from above. The relationship between load and the change in vertical size (mm) was monitored and measured.
[0053] [0053]FIG. 6 shows that when a 330 kg load was applied to a mid-filler attachment 26 the change in vertical size reached 5 mm, and when 710 kg load was applied, the change in vertical size reached 40 mm. (A mid-filler attachment 26 can change vertical size only up to about 40 mm.)
[0054] When a 500 kg load was applied to the mid-filler attachment 36 the change in vertical size reached 20 mm, and when 865 kg load was applied the change in vertical size reached 25 mm. FIG. 6 shows that a mid-filler attachment 36 is capable of absorbing the collision energy equivalent to a load of 1830 kg.
[0055] Materials, size (thickness, width, etc.), shape, and the number of mid-filler attachments used can be varied to optimize the cushioning performance according to the kind of car, collision speed, the car's weight, and so on.
[0056] A method of producing a shock-absorbing guardrail comprises the step of providing a guard fence having a back. Attaching a mid-filler attachment to the back of the guard fence.
[0057] The method can further comprising the step of attaching the mid-filler attachment to a support post so that the mid-filler attachment is positioned between the back of the guard fence and the support post. The method can further comprise attaching a shock absorbing resin between the back of the guard fence and the support post. The method can also further comprise attaching the mid-filler attachment to a structure so that the mid-filler attachment is positioned between the back of the guard fence and the structure.
[0058] The practical examples provided above of the shock-absorbing device described in detailed description is but just a representative example of the possible combinations or assembly of elements disclosed. The examples provided should not be used to limit the usage of the shock-absorbing device. The scope of this invention should be determined by the claims. Therefore, implementation of this invention varies with design change according to the requirements of the specific application.
|
A shock-absorbing guardrail that is easy to install and remove that prevents a support post from collapsing by absorbing the shock caused by a car collision thus reducing repair time. The shock-absorbing device is attached to the guard fence between the structure or support post. A mid-filler attachment may have an ohm-shaped cross-section or vertically opened pipe-shaped cross-section. The guard fence and mid-filler attachment may be attached to the support post or structure with removable connectors for faster installation and removal. The shock-absorbing device is designed to absorb collision energy by irreversible deformation of the mid-filler attachment.
| 4
|
INTRODUCTION
The present invention relates to vehicle parts and components, and the preferred embodiments relate to, e.g., systems and methods for providing vehicle storage and for mounting electronic devices within vehicles, such as, most particularly, trucks or commercial vehicles.
BACKGROUND
In modern times, vehicles, such as, e.g., trucks, buses, cars and the like, often include a variety of electronic devices for an assortment of purposes. By way of example, vehicles can often include one or more of the following electronic devices: citizens band (CB) radios; AM/FM radios; cassette players; CD players; DVD players; video players; cellular phones; global position system (GPS) devices; radar detectors; entertainment devices; computers; etc. Often, these electronic devices are ancillary electronic devices that are not required for the operation of the vehicle itself, but for other purposes (such as, e.g., for business use or operator convenience) during the time period in which the operator is within the vehicle.
However, along with this increase in the number of ancillary electronic devices comes the need for features and structures to accommodate these ancillary electronic devices. The requirements imposed upon vehicle dash boards, consoles and other interior elements have, thus, increased over recent years, becoming increasingly complex and costly. Among other things, consoles often need to accommodate a variety of ancillary electronic devices. Meanwhile, there is also an increasing need to provide vehicle operators with increased vehicle storage space. As the complexities of vehicle dash boards, consoles and the like increase so do the costs related to the manufacture of these components.
While the foregoing issues are germane to both family vehicles (such as, e.g., cars and the like) and commercial vehicles (such as, e.g., trucks, buses and the like), these issues are often more significant in the context of commercial vehicles because, among other things, commercial entities often have business needs to, among other things, a) limit costs, b) increase productivity, and c) reduce equipment down time.
With reference to FIG. 7 , in some existing trucks of the present assignee, an overhead compartment 10 has been implemented for storage and for supporting a CB radio. In such implementations, the compartment 10 has a length in a lateral direction L that is substantially smaller than a width of the truck in which the compartment 10 is installed. In order to mount a CB radio (not shown), a mounting strap 15 (e.g., a strap that is manually attached using hook and loop fastening fabric such as, e.g., VELCRO fastening fabric) has been used to retain the CB radio. In order to mount the compartment 10 within a vehicle, the compartment 10 has been fixedly attached to a headliner (not shown) of the truck via a plurality of mounting brackets BK, which facilitate attachment to the headliner via bolts B.
While the system shown in FIG. 7 provides convenient overhead access for an operator, it is appreciated that there are a variety of limitations associated with such systems. Among other things, the present invention considers a) that it can be difficult to install a CB radio into such a system (which has limited manual manipulation room for the strap 15 , the power connectors, etc.), b) that a substantial number of components (e.g., including mounting brackets, etc.) are required in such a system, and c) that a substantial number of components parts and associated costs are required to manufacture such a system. Thus, there has been a need to improve such systems to overcome one or more of the above and/or other limitations therein.
In addition to the foregoing background art, a variety of other systems and devices are also known. By way of example, additional background documents include:
a) U.S. Pat. No. 4,888,072, which shows an overhead “accessory support device for [a] vehicle windshield and [a] method of installing;” b) U.S. Pat. No. 4,818,010, which shows an overhead “mounting system for equipment in police vehicles;” c) U.S. Pat. No. 4,717,193, which shows an overhead “shelf for a vehicle cab;” d) U.S. Pat. No. 4,421,190, which shows an “overhead instrument console;” e) U.S. Pat. No. 4,226,460, which shows an overhead “long-distance truck cabin;” and f) U.S. Pat. No. 4,079,987, which shows an overhead “container system for entertainment and communications equipment.”
As set forth below, the preferred embodiments of the present invention provide notable advancements over those described in the documents outlined as well as other existing systems and devices.
SUMMARY
The preferred embodiments of the invention greatly improve upon existing systems and methods.
In some of the illustrative embodiments disclosed herein, an overhead storage unit is provided within a vehicle, such as, e.g., a truck. The storage unit can be used, e.g., to provide storage and/or for supporting an ancillary electronic device, such as, e.g., a CB radio in the vicinity of the operator. As described below, the preferred embodiments include a variety of features having a variety of advantages and/or benefits over existing systems. In some illustrative embodiments, some or all of the following advantages can be achieved over existing systems: 1) consolidation of parts; 2) reduction of costs; 3) improved electronic device mounting structure; 4) ease of use (e.g., freedom for fingers and phalange flexibility); 5) ease of upgrading and/or option changes; and 6) improved electronic-device-storage embodiments.
According to some embodiments, an ancillary electronic device storage assembly for a vehicle is provided that includes: a base configured to support an electronic device; a retaining mechanism configured to span over the electronic device when supported on the base; a moving mechanism configured to move the retaining mechanism against and retain the electronic device; the moving mechanism having a manually driven element that is accessed from an exterior of the storage assembly; whereby the retaining mechanism can move against and retain the electronic device by forces imparted manually by a user while the user's hands are located externally to the storage assembly. In some embodiments, the storage assembly is an overhead storage unit. Preferably, the manually driven element is accessed from below the overhead storage unit. In some preferred embodiments, the electronic device is a CB radio. In some embodiments, the moving mechanism is a screw drive mechanism, and the manually driven element is a head of a screw that can be manually driven with a screw driver.
According to some other embodiments of the invention, an ancillary electronic device assembly for a vehicle is provided that includes: a base configured to support the electronic device; a channel along an upper surface of the base configured to receive wiring of the electronic device; a well proximate a front side of the base into which the channel extends; and at least one electrical connector within the well for electrically connecting the wiring of the electronic device. In some embodiments, the electronic connector is a power connector. Preferably, the base is mounted upon a storage unit having at least one additional storage area, or, more preferably, is mounted upon a storage unit having a plurality of additional storage areas.
According to some other embodiments, an assembly for providing a multi-option overhead storage unit for a vehicle which includes: a single integrally molded storage unit: the storage unit being configured to be mounted proximate a juncture between a ceiling of a vehicle and a front windshield of the vehicle, and the storage unit being sized so as to span across substantially the entire lateral width of the windshield; the storage unit including a plurality of storage compartments located laterally along the storage unit; and at least one of the storage compartments being configured to receive an ancillary electronic device supported on an electronic device support; and an ancillary electronic device support that is mountable within the at least one of the storage compartments; whereby the ancillary electronic device support can be omitted from the storage unit to provide a first option without a supported electronic device, and can be mounted within the at least one of the storage compartments to provide a second option with a supported electronic device. In some embodiments, the storage unit includes a plurality of mounting members, wherein the mounting members are adapted to accommodate headliner mounting locations in a plurality of vehicles having different headliner mounting locations. In some embodiments, the storage unit is configured to be mounted within the plurality of vehicles without additional brackets between the storage unit and the headliners.
According to some other embodiments, an overhead storage unit for a vehicle is provided that includes: a plurality of compartments, the compartments having openings through which a user can access the compartments; a removable electronics components support plate configured to be located over at least one of the openings, the electronics components support plate including at least one of a microphone mount, a plurality of switches, and a power source.
According to some other embodiments, a vehicle having a manufacturer supplied CB radio microphone support is provided that includes: removable manufacturer supplied support plate mounted upon a storage unit of the vehicle; a manufacturer supplied microphone support integrally formed in the support plate; and a CB radio microphone supported on the microphone support.
The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages where applicable. In addition, various embodiments can combine one or more aspect or feature of other embodiments where applicable. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the present invention are shown by way of example, and not limitation, in the accompanying figures, in which like reference numerals indicate like or similar parts, and in which:
FIG. 1 is a side view of an illustrative storage unit within a vehicle in an illustrative overhead position to a vehicle operator;
FIG. 2(A) is a bottom front perspective view of an embodiment of a storage unit along with an ancillary electronic device (such as, e.g., a CB radio) and with an electronics component support plate (such as, e.g., for supporting switches or the like);
FIG. 2(B) is a top rear perspective view of the embodiment shown in FIG. 2(A) ;
FIG. 2(C) is a bottom front perspective view of an embodiment similar to that shown in FIG. 2(A) without an added ancillary electronic device (such as, e.g., a CB radio) and without an added electronics component support plate (such as, e.g., for supporting switches or the like);
FIG. 3(A) is a front top perspective view of certain components of an illustrative support device having a retaining mechanism depicted in a displaced position for explanatory purposes;
FIG. 3(B) is a front top perspective view of certain components of an illustrative support device like that shown in FIG. 3(A) , and with a retaining mechanism depicted in an adjacent position for explanatory purposes;
FIG. 3(C) is a bottom front perspective view of certain components of an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
FIG. 3(D) is a top rear perspective view of certain components of an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
FIG. 3(E) is a top front perspective view of a CB radio mounted upon an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
FIG. 4 is a partial bottom view depicting a storage unit in the vicinity of a CB radio similar to that shown in FIG. 3(A) according to some preferred embodiments;
FIG. 5(A) is a bottom perspective view of an embodiment of a storage unit similar to that shown in FIG. 2 , which includes an ancillary electronic device and an electronics component support plate;
FIG. 5(B) is a top rear perspective view of the embodiment shown in FIG. 5(A) ;
FIG. 5(C) is a perspective view of an illustrative mounting structure that receives a hanging element of a microphone;
FIG. 6 is a diagram schematically depicting a bottom view of a storage unit 210 mounted upon a headliner or ceiling within a vehicle; and
FIG. 7 is a top perspective view of another system of the present assignee over which the present invention improves upon.
DETAILED DESCRIPTION
While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and that such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
1. General
With reference to FIG. 1 , an illustrative embodiment of an overhead storage unit 110 is shown within a vehicle, such as, e.g., a truck 140 . The storage unit 110 can be used, e.g., to provide storage and/or for supporting an ancillary electronic device, such as, e.g., a CB radio 120 in the vicinity of the operator 130 . Preferably, the electronic device is located in an ergonomically desirable position, such as in the illustrative example shown in FIG. 1 . As described below, the preferred embodiments include a variety of features having a variety of advantages and/or benefits over existing systems. In some illustrative embodiments, some or all of the following advantages can be achieved over existing systems.
a. Consolidation of Parts
In the preferred embodiments, a storage unit 110 is provided that greatly limits the amount of materials and component parts. By way of example, in the preferred embodiments, the storage unit 110 can include, e.g., a) a single unitary unit configured to span across of width of the vehicle, b) a unit that is mounted without the use of additional brackets required in existing systems (such as, e.g., employing reinforcing ribs to structurally enhance the storage unit itself, employing mounting hole positions arranged to match headliners of plural vehicles and/or the like), d) an elimination of rigid door structures by implementing, e.g., nets, fabrics and/or the like.
b. Reduction of Costs
In the preferred embodiments, a storage unit 110 is provided that can reduce costs considerably over existing systems.
c. Improved Electronic Device Mounting Structure
In the preferred embodiments, a storage unit 110 is provided that includes an electronic device mounting structure having substantial advantages and benefits over existing systems.
d. Ease of Use (e.g., Freedom For Fingers and Phalangeal Motion)
In the preferred embodiments, a storage unit 110 is provided upon which, e.g., an electronic device can be easily manually installed by an individual, without space restrictions that may otherwise impede freedom of movement as in existing devices.
e. Ease of Upgrading and/or Option Changes
In the preferred embodiments, a storage unit 110 is provided that can be readily adapted to different installations options. For example, in some embodiments, a storage unit 110 is provided that can be readily marketed in a first option as a storage unit without an ancillary-electronic-device (e.g., storage-only) or, alternately, in a second option as an ancillary-electronic-device(s) (e.g., CB radio and/or other devices) supporting storage unit.
2. Electronic-Device-Storage Embodiments
FIGS. 2(A) and 2(B) show an illustrative embodiment of a storage unit 210 which includes at least one storage area(s) and at least one mounting structure for an ancillary-electronic-device 220 .
As shown, the storage unit 210 preferably has a length in a lateral direction L such that it extends across substantially the entire width of a vehicle (such as, e.g., a truck 140 as shown in FIG. 1 ) between left and right sides of the vehicle. In this regard, the length of the storage unit 210 in the lateral direction L is preferably approximately the same as that of the front windshield 150 shown in FIG. 1 . In addition, as depicted in FIG. 1 , the storage unit 210 is preferably configured so as to be located predominantly above the operator's field of view through the front windshield 150 .
In some preferred embodiments, the storage unit 210 is formed from an integral unitary piece of material (such as, e.g., from an injection molded elastomeric or plastic material and/or any other suitable material). In some preferred constructions, the storage unit 210 includes at least a front wall 211 and a bottom wall 212 . In some preferred embodiments, the upper end of the front wall 211 includes mounting members 211 M located to facilitate mounting directly to the roof of the vehicle (such as, e.g., shown in FIG. 1 ) without intermediate brackets structures or the like. In addition, the storage unit 210 can also include left and right lateral side walls 213 L and 213 R, respectively. As depicted, the upper edges 213 UE of the left and right lateral side walls 213 L and 213 R are preferably contoured to follow the contour of the vehicle ceiling in some embodiments.
In some embodiments, as illustrated, the bottom wall 212 can include other elements mounted thereon, such as, e.g., sun visors 212 V and/or other elements (such as, e.g., lights, electronic-devices, radar detectors, etc.). In embodiments having visors 212 V mounted thereto, such visors 212 V can be mounted, e.g., to pivot from an underside of the bottom wall 212 , such as, e.g., about hinges 212 HI. The hinges 212 HI can, in some instances, be mounted so as to pivot from a rearward side of the bottom wall 212 (such as, e.g., shown at the left or driver's side of the storage unit 210 ) and/or from a forward side of the bottom wall 212 (such as, e.g., shown at the right or passenger's side of the storage unit 210 ).
In some preferred embodiments, as shown, the front wall 211 includes a plurality of storage openings 230 through which personal items and/or the like for the vehicle operator or user can be placed for storage. In the illustrative embodiment shown in FIGS. 2(A) and 2(B) , the storage openings include three storage openings 230 A, 230 B and 230 C. However, in other embodiments, the storage unit 210 can include any number of openings, such as, e.g., from one opening to any number of desired openings.
In some preferred embodiments, as shown in FIG. 2(A) , the storage unit 210 also includes a plurality of other storage openings 230 D and 230 E that are used for pre-mounting vehicular items. In particular, in the preferred embodiments, the opening 230 E is configured to receive an ancillary-electronic-device, such as, e.g., a CB radio 220 , and the opening 230 D is configured to receive an electronics-components-support structure, such as, e.g., an electronics-components-support-plate 240 .
As shown in FIG. 2(B) , and as discussed further below, with reference to FIGS. 3(A)-3(E) , the CB radio 220 , or the like, is preferably mounted upon the support unit 210 via an electronic-device-support 250 (including, e.g., a support platform) and a retaining mechanism 260 (including, e.g., a clamping member, such as, e.g., a rigid element, such as, e.g., a beam, and/or a flexible element, such as, e.g., a strap). In the preferred embodiments, however, the retaining mechanism is configured to retain the CB radio 220 or the like by the application of a manual force external to the support unit 220 such as to, e.g., effect movement of the retaining mechanism 260 by easy access external to the storage unit 210 . See, e.g., arrow AA shown in FIG. 1 representing an illustrative point of external access in some illustrative embodiments.
Preferably, the storage openings 230 A, 230 B and/or 230 C, which have no pre-mounted vehicular items therein, can be used by a vehicle operator or the like to freely store items therein as desired. In some preferred embodiments, rather than utilizing, e.g., rigid doors to cover the front of these openings 230 A, 230 B and/or 230 C, these openings are at least partly covered with a retaining-netting 230 RN that is stretched across these openings. In some embodiments, the netting can be replaced with a retaining fabric (see, e.g., retaining fabric 230 RF shown in FIGS. 5(A) and 5(B) ) or another flexible material. Or, alternatively, one or more of the openings can either remain uncovered or can be provided with a rigidly attached door or the like. As illustrated in FIG. 2(A) , the retaining netting preferably extends upwardly a vertical height that is sufficient to retain items within compartments behind the openings, while providing a sufficient depth d to allow a user to freely pass their hands through the opening to grasp items stored thereon and/or to place items thereon. In the preferred embodiments, the upper edge of the retaining-netting 230 RN is supported upon an elastic wire or string 230 EL. The retaining netting 230 RN can be mounted to the storage unit 210 using a variety of mounting mechanisms, such as, e.g., rivets, screws, clamps and/or tying the netting to mounts on the storage unit.
As shown in FIG. 2(B) , in some preferred embodiments, the storage unit 210 includes a plurality of divider elements 270 distributed at one or more position, preferably at a plurality of positions, along the lateral length L of the unit. In the illustrative example, three divider elements 270 are implemented. In some examples, the divider elements could be integrally formed with the storage unit 220 (such as, e.g., by forming the unit 210 and the divider elements 270 together in the same injection molding process). In other examples, the divider elements could be removably attachable to the unit 210 , such as, e.g., by inserting the elements into respective receiving slots and/or otherwise mounting the divider elements to the unit 210 . Among other things, the employment of insertable divider elements 270 can enable the elements to be added and/or removed as desired; for example, to accommodate larger items, in some examples a removable divider element 270 could be either omitted in the original installation by the manufacturer or removed by a consumer or user after purchase of the vehicle.
3. Limited Use (e.g., Storage Only) Embodiments
FIG. 2(C) shows another embodiment of the invention in which a storage unit 210 similar to that shown in FIGS. 2(A) and 2(B) is implemented without an electronics-components-support-plate 240 and without an ancillary electronic device, such as, e.g., a CB radio 220 . Accordingly, in this illustrative embodiment, the storage unit 210 can be used to provide a plurality of convenient storage compartments. It should be appreciated based on this disclosure that this embodiment can be substantially similar to and can be modified in a like manner to the embodiment shown in FIGS. 2(A) and 2(B) . By way of example, all of the various other features described above but not shown in FIG. 2(C) can be employed herein, such as, e.g., divider elements 270 , mounting elements 211 M, etc. In addition, as in the foregoing embodiment shown in FIGS. 2(A) and 2(B) , the number of openings 230 can be modified between different embodiments.
In some preferred embodiments, at least some of the same component parts can be used to provide a first storage unit option that is similar to that shown in FIG. 2(C) and to provide a second storage unit option that is similar to that shown in FIGS. 2(A) and 2(B) . In this manner, by way of example, a manufacturer can utilize the same or similar parts to manufacture both options, with the exception that, e.g., in the second storage unit option, one or more of the electronics-components-support-plate 240 and/or the ancillary-electronics-device 220 can be provided.
4. Illustrative Electronic Device Mounting Structures
FIGS. 3(A) to 3(E) show some preferred embodiments depicting an illustrative electronic device support 250 and an illustrative corresponding retaining mechanism 260 . In this regard, as shown in FIG. 3(A) , in some embodiments, the electronic device support 250 can include, e.g., a base wall 251 upon which an electronic device can be supported. As also shown in FIG. 3(A) , in some embodiments, the support 250 can include left and right side walls 252 L and 252 R. In some embodiments, at least one of the sidewalls, such as, e.g., the side wall 252 L can include an integrally formed (e.g., integrally molded) mount 252 M, such as, e.g., an upwardly extending hook-shaped member (e.g., or clip) as shown for receiving wiring of the electronic device and/or the like.
In the preferred embodiments, the base wall 251 includes a number of advantageous features, such as, e.g., one or more, preferably all of the following features in the preferred embodiments.
First, the base wall 251 preferably includes a large array of through-holes 251 H. Preferably, these through-holes 251 H are sufficient to allow an electronic device that allow for the passage of acoustic sounds to and/or from the electronic device (such as, e.g., via a speaker, which in, e.g., a CB radio is often mounted on a bottom surface of the CB radio) so as to freely transmit and/or receive sound therethrough. With reference to FIG. 4 , when mounted within the storage unit 210 , the through-holes 251 H preferably align with an array of through-holes 212 HH formed in the bottom wall 212 of the storage unit 210 . In the preferred embodiments, as shown, the through-holes 212 HH are located within a forward protrusion section 211 FP of the front wall 211 .
Second, with reference to FIGS. 3(A) and 3(B) , during placement of the support 250 upon the storage unit 210 , downward projections 251 DP preferably are received within respective receptacles (not shown) such as to readily align the support 250 with respect to the storage unit 210 structure. In some illustrative and non-limiting embodiments, the downward projections 251 DP and the receptacles can include connection mechanisms (such as, e.g., snap-fit members, press-fit members, clamps, bolts and/or the like) to facilitate retention of the support 250 upon the storage unit 210 once assembled thereon. By way of example, one or more of the projections 251 DP can include a projecting pin 251 P that can be press-fit into a resilient press-fit retaining washer 251 R that is fixed in relation to the support unit receptacles (not shown). In some preferred embodiments, the members 251 P can be screws that are screwed into the support unit.
Third, the support 250 preferably also includes a variety of elements to facilitate usage and management of electronic device wiring, cables and/or the like. In this regard, the support 250 preferably includes at least one, preferably all, of the following features.
a. A channel 251 S for receiving wiring, cables and/or the like of the electronic device 220 mounted thereon, such as, e.g., in preferred embodiments a CB radio wiring harness. In this regard, often CB radios and other electronic devices include wires that extend from a rear of the device 220 , such as, e.g., shown in dashed lines at reference number W in FIG. 3(D) . In preferred embodiments, the channel 251 S is adapted to extend from proximate a rear of the support 250 toward a front side of the support 250 where a user can more easily and/or more ergonomically access the wiring. As shown in FIGS. 3(A) and 3(B) , the channel 251 S can also include one or more, preferably a plurality, of overhanging tang members 251 T which can help to retain wiring within the channel 251 S after it is manipulated therein. It is contemplated, however, that in some embodiments, in which wiring may extend from a side of the device, a channel 251 S could extend along a different path as long as it is directed to a well region 251 W as discussed below. b. A well region 251 W formed proximate a front of the support 250 . In use, an installer, a customer or the like can manipulate flexible wiring of a CB radio or the like so as to be situated within the channel 251 S and to rest upon the base 251 as shown in FIG. 3(D) . As shown in FIG. 3(E) , a forward end of the wiring can be connected at, e.g., Wa and Wb, respectively, to the power connectors PC 1 and PC 2 which are conveniently located within the well 251 W proximate a front side of the support 250 . While any known type of electrical connector can be employed, in some illustrative embodiments, the connectors PC 1 and PC 2 include rotatable connector members (such as, e.g., employing two threadingly engaged clamping members) that can be conveniently rotated clockwise or counter clockwise around axes generally parallel to a front face of the CB radio or the like. In this manner, the power connectors PC 1 and PC 2 can be easily and ergonomically grasped and manipulated (e.g., rotated with one's fingers) within the well 251 W. Here, the size and depth of the well is preferably configured to provide appreciable user freedom of movement (e.g., freedom for fingers and phalanges) c. One or a plurality of integrally formed, e.g., molded-in, mounts (such as, e.g., two in the illustrated embodiments), such as, e.g., clips 251 CL, for CB-radio connectors. In the preferred embodiments, these integrally formed mounts, e.g., clips 251 CL, will enable the electrical harness to be readily secured at a proper location without the need for additional hardware. In this regard, as described above, it is also noted that the support 250 can also include one or more integrally formed mount 252 M, such as, e.g., an upwardly extending hook-shaped member (e.g., clip) for receiving wiring of the electronic device and/or the like, such as, e.g., shown in FIGS. 3(A) and 3(B) .
As indicated above, FIGS. 3(A) to 3(E) also show some preferred embodiments of a retaining mechanism 260 . As shown in FIG. 3B , the retaining mechanism 260 includes a retaining member 262 . According to one aspect of the present embodiment, the retaining member and the support 250 cooperate to define an electronic device receiving space 250 R located between the retaining member 262 and the support 250 . As shown, the retaining member 262 includes a first position 262 A whereat the electronic device receiving space 250 R is provided with a first dimension 250 R 1 . Also, shown therein, the retaining member 262 includes a second position 262 B whereat the electronic device receiving space 250 R is provided with a second dimension 350 R 2 . As shown, the first dimension 250 R 1 is greater than the second dimension 250 R 2 .
Referring now to FIG. 3(E) , as shown in this illustrative embodiment, the retaining mechanism 260 includes the inverted generally U-shaped member 262 . In some preferred embodiments, the generally U-shaped member is a generally rigid member made with an elastomeric or plastic material. In some illustrative embodiments, as with the support 250 and the storage unit 210 , the generally U-shaped member 262 can be made as an injection molded element. In some preferred embodiments, the retaining mechanism is normally biased upwardly, such as, e.g., by using a spring. In this manner, a user can freely locate a CB radio or the like beneath the generally U-shaped member 262 and into the electronic device receiving portion 250 R while the springs bias the member upwardly. Preferably, the retaining mechanism 260 is movably mounted via a movement mechanism 264 so that it can be moved (e.g., drawn) downward, such as, for example, from the first position 262 A, shown in FIG. 3B , to the second position 262 B, shown in FIG. 3B , so as to impinge against the surface of the CB radio or the like so as to retain the device. In this regard, any appropriate movement mechanism 264 can be employed in various embodiments, such as, e.g., a threaded screw shaft assembly, a cam mechanism, a pulley structure, a flexible strap or lanyard, a motor and/or the like.
In an illustrative preferred embodiment, screws 267 , the heads of which are seen in FIG. 4 , extend through through-holes 251 RH, shown in, e.g., FIG. 3(C) , within the base 251 of the support 250 in such a manner that heads of the screws will not pass there-through. Then, the threaded ends of the screws 267 are threaded into a threaded element 265 fixed to, and integrally formed with, the generally U-shaped member 262 . Moreover, as illustrated in FIG. 4 , the bottom wall 212 of the storage unit 210 preferably includes through-holes 212 H via which the screws 267 can be readily accessed for tightening and/or loosening from a user access position external to the storage unit 210 (e.g., from beneath the storage unit 210 in this illustrative example). Preferably, this external user access can be made with a minimal amount of access room for manipulation inside the storage unit 210 in order to achieve mounting of the CB radio or the like. By way of example, the diameter of the through-holes 212 H can be significantly less than a minimum size required for manual access, such as, e.g., being less than an inch in diameter, or even less than one half of an inch in diameter, or even substantially less in some embodiments.
As a result, in order to mount a CB radio or another electronic device on the support 250 , the generally U-shaped member 262 can be clamped against the device, such as, e.g., shown in FIG. 3(D) . Preferably, as shown in FIGS. 3(C) and 3(E) , a bottom side of the member 262 is generally flat so as to apply a generally consistent force against the electronic device. In addition, preferably, the bottom side of the member 262 includes a thin foam pad attached thereto (such as, e.g., having a thickness of a few millimeters) so as to enhance gripping of the CB radio or the like, to distribute forces and/or the like. As shown in FIG. 3(D) , in some preferred embodiments, the member 262 can be formed with one or more, preferably a plurality of reinforcing ribs 262 to enhance the strength and rigidity of the member.
Referring once again to FIG. 3(A) , in some illustrative and non-limiting embodiments, the member 262 is configured such that a maximum width or span s 1 is between about 180 and 270 millimeters, or, more preferably, between about 200 and 250 millimeters, or, more preferably, between about 220 and 230 millimeters, or, more preferably, about 226 millimeters. In addition, in some illustrative and non-limiting embodiments, the member 260 is movably supported, such as, e.g., via a movement mechanism 264 , so as to have a maximum height (such as, e.g., in a fully outwardly biased state) from a bottom of the member 262 to the surface of the base 251 of between about 60 to 80 millimeters, or, more preferably, about 70 millimeters, and so as to have a minimum height from a bottom of the member 262 to the surface of the base 251 of between about 40 to 50 millimeters, or, more preferably, about 46 millimeters. In some illustrative and non-limiting embodiments, the devices shown in FIGS. 2(A) to 5(B) are depicted as to scale and proportional in size, such that some illustrative sizes and proportions can be understood based upon a comparison of the figures and the illustrative dimensions identified above in this paragraph.
5. Illustrative Electronics-Components-Support-Plate Structures
As discussed above, and as best shown in FIGS. 2(A) and 5(A) , in some preferred embodiments a storage unit 210 is adapted so as to include an electronics-components-support structure, such as, e.g., an electronics-components-support-plate 240 .
In some preferred embodiments, the electronics-components-support-plate 240 preferably includes a plurality of switches 240 S. Although FIGS. 2(A) and 5(A) depict illustrative embodiments having 4 switches, it is contemplated that in various embodiments one or more switches can be provided. In a various embodiments, the switches can enable an increased level of versatility, and can be employed by a manufacturer, an owner of the vehicle and/or an operator of the vehicle to provide desired functionality based on existing electrical needs, etc.
In some preferred embodiments, the electronics-components-support-plate 240 preferably includes an electrical outlet (not shown, but which can be, e.g., located at opening 240 E) for electrical power supply. In some embodiments, the electrical outlet can be adapted to function as a 24 Volt electrical outlet, as a 12 Volt electrical outlet and/or as another desired electrical outlet. In a various embodiments, the provision of an electrical outlet can similarly provide an increased level of versatility.
In some preferred embodiments, electronics-components-support-plate 240 includes an fixedly attached or integrally formed mounted mounting structure 240 MK, which is adapted for receiving a hanging element HM of a microphone (such as, e.g., the microphone M shown in FIG. 1 ). With the provision of such a hanging element, a CB radio or the like can readily be mounted within the vehicle in a simplistic manner without the need for the addition of unsightly or crude microphone supports by a consumer. Among other things, by providing the hanging element HM as formed as part of a component of the vehicle, a higher level of aesthetic quality and craftsmanship can be achieved, additional convenience can be achieved, and increased utility can be achieved. Moreover, by providing the hanging element HM in a manner that it can be readily added to and/or removed from the storage unit, a higher level of versatility and a wider range of user options can be achieved.
The manner in which the electronics-components-support-plate 240 is mounted upon the storage unit 210 can vary depending on circumstances. By way of example, in some embodiments, a lower end of the plate 240 can be received in a slot (not shown) and the upper end can be pivoted into position. Then, the mounting members 211 M (e.g., which can include, for example, screws or the like) can be used to retain the upper end of the plate 240 in position. In some embodiments (as shown in FIG. 5 (B)), the same screws that are used to support the upper end of the plate 240 can also be used to mount the storage unit 210 upon the headliner of a vehicle (e.g., by attachment directly to the headliner).
In addition to the foregoing electronics components that can be supported on the electronics-components-support-plate 240 , in various other embodiments a variety of other electronics components can be supported thereon based on circumstances.
6. Illustrative Vehicle Ceiling and/or Headliner Mounting Structures
As discussed above, in existing systems of the present assignee, as depicted in FIG. 7 , an overhead storage unit 10 required the implementation of mounting brackets BK (shown in dashed lines) which were used to mount the storage unit to a headliner of the vehicle. As shown in FIG. 7 , the bracket BK includes two illustrative bolts B that pass through mounting bracket BK so as to retain the bracket to the headliner. In turn, the mounting bracket, which is fixed to the storage unit, thus, supports the storage unit indirectly from the headliner.
On the other hand, according to some preferred embodiments of the invention, such additional mounting brackets are eliminated. Accordingly, the storage unit 210 according to these preferred embodiments can be directly mounted to the headliner. In this regard, as shown in FIG. 5(B) , the upwardly projecting screws at the mounting member locations 211 M can be directly screwed into the headliner.
In order to facilitate such direct attachment without the use of added bracket structures (i.e., since such bracket structures are typically made of metal and provide a higher strength and rigidity), the storage unit 210 is preferably modified to include strength enhanced edges, so as to facilitate such attachment. By way of example, as shown in FIG. 5(B) , in some embodiments the upper end of the front wall 211 preferably includes a widened strengthening element 280 that is integrally and unitarily formed with the storage unit 210 . By way of example, the strengthening element 280 can include, e.g., as shown, an overhanging wall having a plurality of reinforcing ribs 281 distributed there-over. In the preferred embodiments, the strengthening element 280 extends substantially along the length of the storage unit and extends between and connects the respective mounting member locations 211 M as shown.
In addition, in some preferred embodiments as shown in FIG. 5(A) , a plurality of caps or cover elements CP can be mounted (e.g., snap fit, or press fit) over the respective screw locations corresponding to mounting member locations 211 M. Accordingly, in order to mount the storage unit within a vehicle, the caps CP can be removed, the unit can be screwed into place, and then the caps CP can be added. In this manner, the storage unit can be readily attached without costly, complex and bulky bracket members, and while the storage unit is, hence, itself screwed to the headliner in some preferred embodiments, the screws for such an attachment are kept from view and an increased level of aesthetic appeal and refinement can be achieved.
In order to maintain a high quality aesthetic appearance, it is helpful to avoid unnecessary exposure of screws, connectors or the like. In addition to the use of caps CP, which help to obscure unsightly screws, it is noteworthy that the screws 267 (shown in FIG. 4 ) which remain uncovered in some preferred embodiments (e.g., to facilitate easy opening and closing of the moving mechanism 264 via the use of, e.g., an ordinary screw-driver by the owner or user) are, while uncovered, effectively obscured from view. First, the screw located in the array of holes 212 HH, is located within a similarly shaped hole 212 H in such a manner as to camouflage the screws presence. Second, the other of the two screws is located underneath the visor 212 V, such that, for the most part, the second screw is similarly obstructed from view.
In prior overhead storage systems, there have typically been additional complexities and costs that arise due to the implementation of such overhead storage systems in a plurality of vehicle models, having a plurality of internal structures, and, including a variety of headliner structures. Previously, different parts were required to be used for different vehicles and different headliner structures. This previously lead to increased complexities and increased costs. Accordingly, in some of the preferred embodiments herein, the mounting structure is specifically designed so as to accommodate a variety of vehicles, such as, e.g., by accommodating a variety of headliner structures.
By way of example, in some illustrative embodiments, with reference to FIGS. 5(A) and 5(B) , the multiple mounting member locations 211 M are preferably selected upon initial design and manufacture to correspond to the headliner structure of a plurality of vehicles (such as, e.g., a whole line of vehicles, which can include, e.g., two, five, ten or more vehicles). By way of example, in mounting the storage unit 210 into certain vehicles one or more of the mounting members 211 M may be extraneous and, hence, not utilized depending on the headliner structure of that vehicle. For example, FIG. 6 is a schematic diagram depicting an upward view of the bottom of a storage unit 210 as mounted upon the headliner 290 . By way of example, consider that one vehicle may have mounting locations corresponding to positions A 1 , A 2 and A 4 , while another vehicle may have mounting locations corresponding to positions A 1 , A 3 and A 4 . Accordingly, in the preferred embodiments, the storage unit 210 is modified so as to include appropriate mounting locations for a plurality of vehicles. In this manner, a substantial reduction in parts and cost savings can be realized. Moreover, in some embodiments, the mounting members 211 M can include through-holes for receiving screws that are screwed into the headliner. In some cases, to provide increased versatility in the applicability of the storage unit 210 to different vehicles, at least some of the through-holes can be elongated in the lateral direction L an amount to accommodate variations between at least some of the vehicle mounting requirements (i.e., such that the screw attachment position can vary laterally to some extent within such through-holes).
Broad Scope of the Invention
While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. By way of example, while the detailed description and drawings depict an illustrative overhead storage unit, various aspects of the invention (such as, e.g., the improved electronic device mounting methods) can be employed within a wide variety of environments. In this regard, various features could, e.g., be implemented within dash boards of vehicles, consoles and/or at any other appropriate location as would be appreciated based on this disclosure.
The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language present invention or invention should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure, the following abbreviated terminology may be employed: “e.g.” which means “for example.”
|
An overhead console ( 10 ) spanning the header above the windshield ( 150 ) includes support for a removable electronic device ( 120 ).
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a decorative soffit system for mounting on the bottom of vertically disposed ceiling tile to enclose projections depending from the normal ceiling plane.
2. Description of the Prior Art
Suspended ceiling systems which use inverted-T runners have wide usage in residential and industrial construction. Frequently, the normal plane of the ceiling cannot be continued through portions of a full room size due to depending projections. Projections normally encountered are air ducts, beams, pipes, utility boxes, electrical wiring, and the like. Since it would be undesirable to drop the overall plane of the ceiling to the minimum level required below the deepest of such projections, a soffit construction is typically envisioned for encasing these items.
It would be desirable, considering the wide variety of presently used suspended ceiling systems, to provide a soffit system which is adaptable for use with this assortment, particularly systems utilizing inverted-T runners for ceiling tile support. Such systems typically involve the suspension of inverted-T runners by hanger wires, clips, or adjustable brackets to facilitate leveling. Although particular systems may have soffit members, they usually require specific accommodating features for use in that one system. Moreover, with the wide usage by the individual home owner in constructing suspended ceilings, it would be desirable to accommodate many types of suspended ceiling system designs with a soffit system adaptable for use therein. Typically, in single family residential construction particularly, many depending utility devices exist, such as in basements, where ceiling concealment is desired. It would be most useful in these cases to provide a decorative soffit system which encases such projections without the need for complicated erection procedures and a multiplicity of specialized components.
The particular problems discovered in many prior art ceiling systems involve the proper location and retention of the vertical ceiling tiles, which are disposed alongside the depending projection, and lower support while yet maintaining esthetically pleasing bottom and corner portions. It would be useful to support the lower edges of such vertically extending ceiling tile without the need for rigid mechanical affixation by nails, screws, or the like. This would alleviate additional construction steps and also permit the use of leveling brackets such that the bottom surface of the enclosing soffit structure could be easily aligned parallel planar with the normal ceiling plane.
Moreover, many residential and commercial suspended ceiling systems utilize basically three types of tile edges for various decorative configurations. One conformation is a simple square-edged tile which rests atop flanges of inverted-T runners. A second tile construction has longitudinal kerfing centrally located in the tile edge which accept the flanges of inverted-T runners and conceal them within the kerf. A third type of edge is a rabbet, or notched, design which disposes the lower visible tile surface below the level of the flanges of the inverted-T runner. It would clearly be advantageous to provide a soffit system which is compatible with all three of these basic edge configurations without the need for structural changes in order to enclose such aforementioned depending projections and appurtenances.
In typical installation, main-runners are generally transposed at right angles to upper support joist members with cross-runners transverse thereto. Occasionally, such systems eliminate cross-runners and spline members connect adjacent ceiling tile at joints transverse to the main-runners. Such systems are additionally installable with main-runners being parallel to upper joist members. In either situation, it would be highly desirable to provide a soffit system which would be adaptable to cover depending ceiling projections which run either parallel or transverse to the upper support joist members without the need for special construction techniques or additional components.
OBJECTS OF THE INVENTION
It is a primary object of this invention to provide a decorative soffit system for mounting on the bottom of vertically disposed ceiling tile to enclose a projection depending from a ceiling.
It is accordingly an important object of this invention to provide a suspended ceiling boxed around a projection depending from a ceiling.
It is an attendant object of this invention to provide a soffit system for enclosing projections from the ceiling in a suspended ceiling system which utilize conventional inverted-T runners.
It is therefore a goal of this invention to provide a soffit system for enclosing such depending projections wherein ceiling tile may have kerfed, square, or rabbet edges.
It is also an object of this invention to provide a soffit system which is adaptable for use with suspended ceiling systems wherein main-runners run either parallel or transverse to upper support joist members and wherein depending projections from the ceiling run either parallel, or transverse, to such upper support joist members.
It is a concomitant object of this invention to provide a soffit system which requires no penetrating mechanical fastening at lower edges of vertically disposed soffit ceiling tile and is easily installable by the home consumer.
It is also a goal of this invention to provide a soffit system for both residential and commercial use for enclosing depending projections from the ceiling wherein vertically disposed ceiling tile comprise the side facing of the box-like enclosure for the projection and wherein a ceiling tile is disposed below said projection in parallel planar relationship with the normal plane of the ceiling.
SUMMARY OF THE INVENTION
All the objects and goals of the invention are attained by the provision of a unique decorative soffit system for mounting on the bottom of vertically disposed ceiling panels to enclose a projection depending from a ceiling. The system has a U-shaped channel member adapted to rest on an inverted-T runner and said U-shaped channel member also has a resilient spacer therein to hold the vertically disposed ceiling tile therein against one side thereof.
The goals of the invention are further attained by providing a supported inverted-T runner, a U-shaped channel member resting on one side of the inverted-T runner, a vertically disposed ceiling tile resting in the U-shaped channel member on the side opposite the inverted-T runner, and, means within the U-shaped channel member to hold the vertically disposed ceiling tile against the side thereof.
In further fulfilling the needs of the industry, a suspended ceiling is provided for boxing around a projection depending from ceiling joists. The suspended ceiling system comprises a plurality of suspension brackets depending from the ceiling and terminating at the bottom thereof in inverted-T runners, a plurality of ceiling tiles resting on the inverted-T runners, and, at least one U-shaped channel resting on an inverted-T runner adjacent to the projection depending from the ceiling and having a vertically disposed ceiling tile resting therein, and means for holding the ceiling tile against the side of the U-shaped channel member.
In further fulfilling the desirable goals of the invention, an apparatus is provided for use in the soffit system for enabling a decorative suspended ceiling system to be boxed around a projection depending from a ceiling joist, said apparatus comprising a U-shaped channel member with a decorative outside surface.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating the preferred embodiment for the soffit system of this invention boxing around a beam supported transverse to an upper support joist member which is a support for a suspended ceiling system.
FIG. 2 is a cross-sectional view of a soffit system in accordance with the preferred embodiment of this invention showing an air duct and pipe depending from an upper support joist member with said air duct and pipe being enclosed by the soffit system.
FIG. 3 is a partially blown apart perspective view looking downwardly at the preferred embodiment of the soffit system in this invention illustrating the enclosing for projections depending from a ceiling in a suspended ceiling system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The soffit system for suspended ceiling system of this invention is more fully described by reference to the embodiments illustrated in the attached drawings wherein, with first reference to FIG. 1, soffit system 10 is depicted in a cross-sectional view. Upper support joist 11 has beam 12 projecting downwardly therefrom. Disposed below, providing the normal plane of the ceiling, resides ceiling tile 13 in parallel planar relationship having edges 14 supported at and along inverted-T runners 15. Connecting inverted-T runners 15 with upper support joists 11 are adjustable brackets 16 attached thereto by screw fasteners 17. In order to level ceiling tile 13 after installation, adjustable means 18 comprises part of adjustable bracket 16. Adjustable bracket 16 further has alternate attachment plate 19 disposed at 90° to question mark-shaped body portion 20. Adjacent inverted-T runners 15 at the side opposite ceiling tile 13, reside ceiling tile 21 disposed in a vertical orientation and providing the decorative side facing for the enclosing box-like configuration of soffit system 10. Inverted-T runners 15 secure ceiling tile 21 with said screw fastener 17 passing through the web of the runner and extending into the ceiling tile 21.
A characterizing feature of this invention, shown in FIG. 1, involves the connection at lower edges 22 of ceiling tile 21 with decorative members and supportive members whereby projections from ceilings may be easily enclosed in a sturdy soffit structure. A second set of brackets being adjustable brackets 26 extend from upper joist 11 for support of a lower set of runners being inverted-T runners 25 which are conventionally used flanged runners. Adjustable brackets 26 engage inverted-T runners 25 by means of screw fasteners 27 extending therethrough. In order to level lower ceiling tile 23 of soffit system 10, adjustable means 28 comprises part of adjustable bracket 26 and affords leveling during installation procedures such that ceiling 23 may be placed in parallel planar relationship with ceiling tile 13. Adjustable brackets 26 are substantially identical to adjustable brackets 16 with regard to alternate attachment plate 29 residing at generally 90° relationship with the question mark- shaped body portion 30. In order to effectively support ceiling tile 21 in a vertical orientation while at the same time providing a decorative lower portion for soffit system 10, U-shaped channel 31 is provided and interconnects lower edge 24 with inverted-T runners 25. Thus ceiling tile 21 rests within U-shaped channel 31. Disposed between ceiling tile 21 and inverted-T runner 25 is resilient clip 35 which upon installation effectively retains ceiling tile 21 in position within U-shaped channel 31 and additionally allows removability for access within the enclosure since no mechanical affixation at lower edge 24 is required. U-shaped channel 31, at the side opposite ceiling tile 21, rests upon inverted-T runner 25 in supportive relationship thereto. Disposed between parallel adjacent inverted-T runners 25 is ceiling tile 23 having edges 24 resting on flanges of inverted-T runners 25 for support. U-shaped channels 31 are preferably comprised of light-gauge steel having an enamel finish which can be provided in various colors to coordinate in a decorative and esthetically pleasing combination with decorative lower flange portions of inverted-T runners 15 and 25 which are viewable from below.
Soffit system 10 as shown in FIG. 1 is provided wherein inverted-T runners 15 are main-runners supporting ceiling tiles 13 and are disposed transverse to upper support joists 11. It is readily apparent that main-runners, inverted-T runners 15, could be alternately disposed parallel to upper support joists 11 and thus in order to enclose beam 12, cross-runners would be disposed transverse to upper support joists 11 in an orientation which in cross-section, would appear substantially identical to the configuration shown in FIG. 1. Soffit system 10 is usable whether the orientation of main-runners is parallel or transverse to upper support members and in either case whether projections run parallel or transverse to upper support members.
Turning now to FIG. 2, soffit system 10 is shown in an altered conformation illustrating the versatility of the invention for use with multiple projections to be enclosed. In this Figure, an air duct 36 and pipe assembly 37 are enclosed. Similar to FIG. 1, FIG. 2 provides upper support joist 11 wherein an adjustable bracket 16 is dependent therefrom but having a different manner of vertical adjustability from that disclosed in FIG. 1. Differing from the embodiment shown in FIG. 1, adjustable bracket 16 is not provided with adjustable means 18 but vertical adjustment is alternately attained nonetheless whereby alternate attachment plate is vertically movable by means of slot 38 with fastener 39 extending therethrough. Slot 38 allows for adjustment by vertically moving it to position slot 38 and fastener 39 at the proper elevation. A second hole 40 allows rigid securement by means of fastener 41 extending therethrough after proper vertical alignment is attained. Attachment plate 19 is disposed at 90° with question-mark shaped body portion 20 wherein body portion 20 connects with inverted-T runners 15 by means of screw fasteners 17 extending therethrough. Ceiling tile 13, lying in the normal plane of the ceiling, has edge 14 resting on a flange of inverted-T runner 15 for support. Additionally, screw fastener 17 penetrates vertically disposed ceiling tile 21 for affixation thereto. Ceiling tile 21 terminates in a lower edge 22 resting within U-shaped channel 31 and resiliently spaced from inverted-T runners 25 by resilient clip 35.
Continuing with FIG. 2, adjustable brackets 26 depend from upper joist member 11 and secure inverted-T runner 25 below. Adjustable brackets 26 have adjustable means 28 for vertical alteration in order to properly level ceiling panel 23 below. Ceiling tile 23 is attached to inverted-T runners 25 which are supported by adjustable brackets 26. Ceiling tile 23 terminates in side edges 24 which in this configuration are shown to be kerfed edges nested around flanges of inverted-T runners 25. U-shaped channel 31 is supported at the flange opposite the attachment with lower edge 24 and provides a decorative surface when viewed from below. FIG. 2 additionally provides a second projection depending from the ceiling above, being pipe assembly 37, and a second ceiling tile 23 is shown disposed below to provide a lower ceiling surface for soffit system 10 enclosing both air duct 36 and pipe 37. Ceiling tile 23 below pipe assembly 37 is shown having side edge 24 also with a kerfed configuration nested around flanges of inverted-T runner 25 for support. A second vertically disposed ceiling tile 21, not shown, but, if required, could be placed at the other side of pipe 37 in a similar manner as shown in FIG. 1 for completing the enclosing of the projection by extending upward to the normal ceiling plane at a ceiling tile 13. If, however, pipe assembly 37 was adjacent a wall, a ceiling tile 21 would not be mandated and ceiling tile 23 would simply horizontally continue to supportively engage the wall.
With reference to FIG. 3, soffit system 10 is shown in an exploded perspective view illustrating the characterizing novel elements therein provided. As previously discussed with regard to FIGS. 1 and 2, ceiling tile 13 is shown supported along flanges of inverted-T runners 15 which in turn are supported by adjustable brackets 16 depending from upper support joists 11. Adjustable brackets have screw fasteners 17 extending therethrough for supportive engagement with inverted-T runner 15. Additionally, adjustable bracket 16 has alternate attachment plate 19 disposed at substantially 90° to body portion 20 whereby affixation may be made with upper support joist 11 with attachable body portion 20 disposed at 90° rotation from the view shown in FIG. 3. Thus accommodation can be made for alignments wherein inverted-T runners 15 are either parallel or transverse to upper support joists 11 and whether projections to be enclosed are disposed in either orientation. Inverted-T runners 15, although shown preferably as main-runners, may be cross-runners of a suspended ceiling system in accordance with this invention. Adjustable means 18 additionally provides for any angle of disposition for projections in that the adjustable means allows omni-directional attachment for adjustable bracket 16. Such adjustable brackets are widely known to the construction industry and suitable apparatuses are disclosed in U.S. Pat. Nos. 3,998,020 and 3,998,419. Such and similar adjustable brackets, and other fixed brackets having a capability of at least attaching parallel or transverse to upper support joist members, are equally suitable for the invention.
Screw fastener 15 penetrates ceiling panel 21 for supportive engagement. Ceiling panel 21 is disposed in a vertical orientation providing the side face of soffit system 10 for enclosing projections depending from ceiling portions above. Lower edge 22 of ceiling panel 21 rests within U-shaped channel 31 below. U-shaped channel 31 is provided with a longer side 32 integrally connected with a bottom side 34 that terminates in a shorter side 33 creating a generally U-shape. Ceiling tile 21 abuts shorter side 33 and a resilient clip 35 extends between ceiling tile 21 and longer side 32 affording retentive positioning and removability of ceiling tile 21. Bottom side 34 rests on flanges of inverted-T runners 25 for support. Resilient clip 35 has a generally W-shape formed from light-gauge sheet steel and having a resilient property for securing ceiling tile 21. Disposed at the other side of inverted-T runner 25 is ceiling tile 23 providing the bottom planar surface of soffit system 10 wherein edges 24 supportively engage flanges of inverted-T runners 25. In this embodiment, edges 24 are provided with a rabbet, or notched edge, for a shadow-line effect well known to the construction industry. Supporting inverted-T runner 25 from above is adjustable clip 26 having a similar conformation to adjustable clip 16 and also having such suitable alternative embodiments as those shown in the aforementioned patents. Adjustable bracket 26 engages inverted-T runners 25 by screw fasteners 27 extending therethrough. Adjustable means 28 allows for vertical alterability of the brackets such that during installation ceiling tile 23 are placed in generally parallel planar relationship to ceiling tiles 13 for an esthetically pleasing and workmanlike soffit construction.
Ceiling tile 13 and 23 are preferably comprised of gypsum but may additionally be formed from other well-known construction materials such as wood fiber, mineral wool acoustical tile, wood, ceramic tile, and other well-known materials which are utilized in ceiling systems having inverted-T runners for support. Moreover, as seen in FIGS. 1-3, soffit system 10 of this invention is equally adaptable with varying edge configurations such as previously noted kerfed edge, rabbet edge, or square-edged ceiling tile.
The ease of installation is apparent with reference to the Figures. Whether utilized by the relatively unskilled home owner or the skilled tradesman, the effectiveness of this invention will be well understood. Resilient clip 35 effectively holds ceiling tile 21 within U-shaped channel 31 by its spring-like property. The material desirably comprising U-shaped channel 31 is enamel-covered light-gauge steel providing a decorative surface when viewed from below. Other well-known coatings or surface treatments may be provided for U-shaped channel 31 as would be well known to the metalworking arts. Not only is installation quick, but manufacture is reduced since a multiplicity of components is not required. Additionally, removability of soffit system 10 is provided, whereby access to utility appurtenances is readily available without prolonged time and effort.
It may thus be seen that the new and novel soffit system made possible by this invention is a highly adaptable enclosing apparatus for projections from a ceiling above that produces significant advantages over previously known soffit systems. While the invention has been described in conjunction with specific embodiments thereof, it is evident that alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
|
A decorative soffit system for mounting on the bottom of vertically disposed ceiling tile to enclose a projection depending from the ceiling as disclosed. The soffit system having a U-shaped channel member adapted to rest on an inverted-T runner and said U-shaped channel member having a resilient spacer therein to hold a vertically disposed ceiling tile against one side thereof.
| 4
|
REFERENCE TO PROVISIONAL APPLICATION
Pursuant to 35 U.S.C. § 119(e), this application derives from a provisional application for the same invention filed on Jun. 14, 1996, provisional Ser. No. 60/019,922.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an apparatus and method for increasing the fusion area of a rotatable workpiece (stud, shaft or other) to be friction welded to a substrate of either similar or dissimilar materials or two circular shafts that are to be friction welded together by use of an apparatus that can be removable from the stud, shaft or other weldable devices after the stud is friction welded to the substrate, while limiting the build-up of plastisized matter around the peripheral of the rotatable workpiece. Friction welding, in general, is covered by prior art and it is envisioned the invention disclosed herein could be adaptable to a wide range of friction welding apparatuses since the apparatus disclosed herein could be adapted to most friction welder rotatable workpieces. This invention specifically relates to a friction welding fusion enhancer apparatus which can be utilized with a wide range of friction welder apparatuses, and methods for its use, although not limited to the geometric configurations provided herein.
2. Description of the Prior Art
The joining of materials to form a strong cohesive, high strength, fine grain weld bond is common to industry throughout the world. It is commonly achieved by arc welding, o-xyfule gas welding, flash welding, brazing, soldering, electron beam welding, laser beam welding and other techniques where open flame does not present an explosive hazard. In most cases, the exposed flame or arc creates no hazard and is practical to use. In areas where combustible gases are present, it is not usually possible to use an open flame or arc welding procedure, due to the attendant danger of fire or explosion. Another concern in the bonding of materials is material compatibility. Some materials, such as stainless steel, will not easily bond with aluminum alloys using the aforementioned welding processes.
One solution to the above-outlined problems is the friction weld procedure, which achieves a fusion bond. The friction welding fusion bonding process and its related processes rely on friction heat generation between surfaces to provide a material flux which may be forged to produce an integral bond between the surfaces. In the friction welding process, relative rotation between a pair of workpieces (i.e., the two pieces to be welded together, a rotatable workpiece and a stationary substrate workpiece) is caused while the workpieces are urged together.
After the friction welding process has started, on initial contact of the welding surfaces, there is a "burn-off" phase which removes foreign materials from contact area of both workpieces, The "burn-off" phase, is immediately followed, in an outward radial direction, by an "upset" phase where specific contact areas of both workpieces are turned to a plastic condition causing the establishment of a flux of hot metal due to the relative rotation and high axial pressure urging the two workpieces together, caused by resistive friction between the workpieces. After automatic or operator shutdown of the rotation of the rotatable workpiece, there is a "forging" phase where axial pressure is maintained between the workpieces until the plastisized material cools and the weld fuses during "fusion bonding" phase.
Typically, once sufficient heat is built up at the interface between the workpieces and both workpieces are plastisized at their respective contact areas, relative rotation is stopped and the workpieces are urged together under a forging force which may be the same as or greater than the original forging force.
The advantages of the friction welding process include, but are not limited to: (1) flux and shielding gas are not required; (2) in most cases, the weld strength is as strong as or stronger than the weaker of the two materials being joined; (3) surface cleanliness is not as significant, compared with other welding processes, since friction welding tends to disrupt and displace surface films; (4) there are narrow heat-affected zones; (5) the process is generally environmentally clean; (6) friction welding is suitable for welding most engineering materials and is well suited for joining many dissimilar metal combinations; (7) no filler material is needed; (8) operators are not required to have manual welding skills; (9) the process is easily automated for mass production; and (10) welds are made rapidly compared to other welding processes.
In conventional friction welding, the rotatable workpiece is attached to a motor driven unit and rotated at a predetermined speed, while the other stationary workpiece is maintained in a fixed, stationary orientation. When the appropriate rotational speed is reached, the two workpieces are brought together and an axial force is applied. Heat is generated as a result of the friction generated by the interface of the respective surfaces, which continues for a predetermined time or until a preset amount of upset takes place. Thereafter, the rotational driving force is discontinued and the rotation of the rotatable workpiece is stopped. The axial force between the two members is maintained or increased, however, for a predetermined period of time to finalize the weld. The rotatable workpiece can be cylindrical such as a stud or shaft, square, rectangular or other geometric configuration. The stationary workpiece can also be cylindrical such as a stud or shaft, square, rectangular or other geometric configuration.
The weld product resulting from a conventional friction weld process is characterized by a narrow heat affected zone and the presence of plastically deformed material around the weld which is identified as the fusion area. There are several disadvantages of the friction weld process that impede the achievement of maximum strength at the fusion area: (1) the residual plastically deformed material that is general built up at the base of the weld fusion area, during the upset phase, could cause interference with a mating part unless it is machined or ground off; (2) the plastically deformed material that is generally built up at the base of the weld fusion area, during the upset phase, heats up and cools down at different times and conditions than the center of the fusion area, causing inconsistent fusion zones throughout the rotatable workpiece and stationary substrate workpiece fusion weld area (3) the residual plastically deformed material that is generally built up at the base of the weld fusion area, during the upset phase, could impede the manner in which the material fused together bonds, thus leaving voids and other variations of inconsistent bonding throughout the fusion area and limiting the overall area and strength of the bond.
The friction welding fusion bond achieved, using special automatic techniques developed by the inventor of this invention, has proven the ability to provide for near elimination of build-up of the plastically deformed material which permits free threading of nuts on studs down to the substrate and clean bond areas where shafts are joined together. This may resolve some critical problems. However, the use of this new technique, which limits the build-up plastisized materials, does not eliminate all the concerns. For example, there are still some concerns for maximum achievable strength of the rotatable workpiece when joined to a substrate because: (1) the complete area of the rotatable workpiece is generally not fused, leaving outer perimeter voids, because of difference of temperature strata conditions on both heating and cooling down in both the rotatable workpiece and stationary substrate workpiece; (2) as with conventional friction welding described above, temperature strata conditions on both heating and cooling down will generally leave the outer peripheral edge weak if a bond to the substrate workpiece is achieved.
All friction welders have a means of holding the rotatable workpiece in a collett type device. Some colletts hold the workpiece by mechanically tightening and clamping against the workpiece, other colletts hold the workpiece by threads, still others have a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal clamping mechanism, which tightens up against the workpiece when rotation begins, and other colletts have various geometries to hold the rotatable workpiece during the friction welding process. This invention does not describe a new concept in a friction welding apparatus or a new concept in holding the friction welding rotatable fitting (bolt, stud, shaft, or etc.), but rather this invention deals with a concept that can be made an integral part or attachment to a rotatable friction welding fitting and, in some cases, the substrate, so as to increase strength and versatility of the rotatable workpiece and stationary substrate workpieces. It is pointed out that in some friction welding systems, both workpieces rotate and this invention may become part of both workpieces.
One solution to the above-outlined problems is the friction welding fusion enhancer apparatus, the subject of this invention. The friction welding fusion enhancer apparatus can be made an integral part or attachment to a rotatable friction welding fitting and, in some cases, applicable to the substrate workpiece, so as to increase strength and versatility of the rotatable workpiece and stationary substrate workpieces.
The advantages of the friction welding fusion enhancer apparatus include, but are not limited to: (1) maximum fusion bonding and weld strength can be achieved to and, in some cases, beyond the minor diameter of stud thread areas; (2) undesirable upset material in the form of plastic build-up outside of the fitting fusion area on a substrate can be virtually eliminated, depending on the desired strength of the end product; (3) nuts can be tightened down to the substrate because threads can remain usable once the friction welding fusion enhancer apparatus is removed; (4) rods, shafts or other components can be left in a clean condition, free of undesirable upset material in the form of residual plastisized material build-up present using normal friction welding techniques where maximum strength is achieved by bonding the complete area of the original fitting to the substrate; (5) removal of the friction welding fusion enhancer apparatus can be via threads or this apparatus, if made an integral part of the fitting, can be designed to break-away from the fitting after installation is completed, leaving a clean surface; (6) greater strength is achieved with the friction welding fusion enhancer apparatus.
Thus, while friction welding of one material has met with general acceptance in industry in the installation of fasteners and other components, there has been a need in the art for achieving predictable greater strengths for geometric configuration of specific size and material.
There has been an additional need in the art for friction welding of rods and other geometrical configurations, either to one another or to another substrate where the excessive plastic build-up of material is minimized after the weld is complete.
There has also been a need in the art for friction welding of threaded studs and other threaded components, where the excessive plastic build-up of material is minimized or nearly eliminated, after the weld is complete and nuts or other components can be placed directly against the substrate without the need to first remove unwanted excessive residual plastisized build-up of material normally found when the weld is completed.
There has been an additional need in the art for achieving greater strength in the weld area, eliminating excessive residual build-up of plastisized material without the need for additional machining or grinding and with an apparatus that is easy to install and remove.
SUMMARY OF THE INVENTION
The present invention solves significant problems in the art by providing a friction welding fusion enhancer apparatus and a method for its use. Generally described, the present invention provides for an apparatus that can be installed on an existing rotatable workpiece fitting or become an integral part of a friction welding rotatable workpiece, or in some cases, stationary substrate workpiece, to enhance both strength and versatility of the finished welded product. The friction welding fusion enhancer apparatus generally includes an extended temporary fusion area of similar or dissimilar area to the rotatable workpiece, that can be easily removed after the friction weld process has been completed.
In a preferred embodiment for achieving greater strengths and more even temperature distribution in the fusion area of both the rotatable workpiece and stationary substrate workpiece during the friction welding process, the friction welding fusion enhancer apparatus provides a means and method to achieve stronger bonding of both similar and dissimilar materials. Custom designed adapters that distribute greater temperature in desired fusion bonding area, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece, are easily installed and later removed on the rotatable workpiece fitting, and in specific applications, on both the rotatable workpiece fitting and the stationary workpiece, such as when welding two rods together.
The apparatus includes one or more design type friction welding fusion enhancer apparatuses designed to fit a specific workpiece. The adapters can be threaded onto a stud or be slipped over a rod, stud, or other geometric configuration and held in place by a set screw or other holding means. The adapters will be custom shaped for a range of applications and friction welder apparatuses to achieve greater strength and versatility.
In another preferred embodiment of the invention for achieving greater strengths and more even temperature distribution in the fusion area of both the rotatable workpiece and stationary substrate workpiece during the friction welding process, the friction welding fusion enhancer apparatus provides a means and method to achieve stronger bonding of both similar and dissimilar materials.
Custom fittings where the friction welding fusion enhancer apparatus becomes an integral part of a rotatable workpiece are designed adapters that distribute greater temperature in the fusion bonding area, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece and, in specific applications, on both the rotatable workpiece fitting and the stationary workpiece, such as when welding two rods together.
The apparatus includes a friction welding fusion enhancer apparatus designed as an integral part of a specific workpiece. The rotatable workpiece fittings or stationary workpiece fittings will be shaped for a range of applications and friction welder apparatuses to achieve greater strength and versatility. However, in this embodiment, the friction welding fusion enhancer apparatus will be designed to break-away after the fusion weld is completed to eliminate the excess material, thus offering a clean product, while enhancing the strength of the welded fitting, rod or other fastener. One or more design concepts could be effective.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an exemplary fusion welder which may be used in conjunction with the apparatus of the invention.
FIG. 2 is an overall cross-sectional side view of a preferred embodiment of the adapter type friction welding fusion enhancer apparatus showing the backup threaded nut of the present invention.
FIG. 3 is a proximal end view of the embodiment illustrated in FIG. 2.
FIG. 4 is a distil end view of the embodiment illustrated in FIG. 2.
FIG. 5 is an overall cross-sectional side view of a preferred embodiment of the adapter type friction welding fusion enhancer apparatus showing the set screw fastening of the present invention.
FIG. 6 is an overall cross-sectional side view of a preferred embodiment of the break-away slotted type integrated fitting type friction welding fusion enhancer apparatus of the present invention.
FIG. 7 is a proximal end view of a preferred embodiment of the break-away slotted type integrated fitting type friction welding fusion enhancer apparatus of the present invention.
FIG. 8 is a distal end view of the embodiment of of the apparatus illustrated in FIG. 7.
FIG. 9 is an overall cross-sectional side view of a preferred embodiment of the break-away reaction surface ridge type integrated fitting type friction welding fusion enhancer apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1-9 of the drawings where several preferred embodiments of the friction welding fusion enhancer apparatus are shown where like numerals indicate like elements throughout the views. In any preferred embodiment, the friction welding fusion enhancer apparatus is generally held in place by a standard or custom designed friction welder apparatus workpiece fitting collett 100 (See FIG. 1)
Referring initially to FIGS. 2-5 of the drawings, where preferred embodiments of the friction welding fusion enhancer apparatus are shown where like numerals indicate like elements throughout the views, and the friction welding fusion enhancer apparatus is generally held in place by a standard or custom designed friction welder apparatus workpiece fitting collett 100. Also included is a friction welder rotatable workpiece, a non-integrated rotatable fitting 200, where a slip-on type a friction welding fusion enhancer apparatus 300 is installed on non-integrated rotatable fitting 200. Also included is a substrate workpiece 500 (included for reference--not shown), which could be stationary or rotatable. Friction welding fusion enhancer apparatus 300 can be fabricated as an adapter or be made an integral part of a friction welding fitting as will be described, respectively, in the two preferred embodiments below. Non-integrated rotatable fitting 200, friction welding fusion enhancer apparatus 300 and substrate workpiece 500 can be made from a number of materials, each similar to or dissimilar from the other depending on the application. Such materials include, but are not limited to stainless steel, carbon steel, aluminum alloys, brass, titanium, zirconium alloys and other alloys. These components are integrally coupled in a manner described below.
Referring to FIGS. 1-5, specific friction welder apparatus workpiece fitting colletts 100 could include colletts from any type friction welder, portable or stationary type, where such colletts could hold a non-integrated rotatable fitting 200 by mechanically tightening and clamping against the non-integrated rotatable fitting 200, or hold the non-integrated rotatable fitting 200 by threads, or hold the non-integrated rotatable fitting 200 by means of a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal type clamping mechanism, which tightens up against non-integrated rotatable fitting 200 when rotation begins. There are many other various geometries which are designed to hold the rotatable workpiece during the friction welding process. The collett is part of a friction welder apparatus (see FIG. 1) and is rotated or otherwise moved to create friction and, at the same time, the collett is urged toward the stationary workpiece to complete the friction welding process.
The non-integrated rotatable fitting 200, for a specific application, is designed to fit a specific collett and is inserted into the friction welder apparatus workpiece collett 100 in a secure fashion to permit friction welding of non-integrated rotatable fitting 200 to a substrate of similar or dissimilar materials.
Prior to the installation of non-integrated rotatable fitting 200 into friction welder apparatus workpiece fitting collett 100, a friction welding fusion enhancer apparatus 300 is secured in place in a manner shown in FIGS. 2-5, depending on whether or not the friction welding fusion enhancer apparatus 300 adapter is threaded or otherwise mechanically attached to the non-integrated rotatable fitting 200.
The non-integrated rotatable fitting 200 is generally round in geometry, but can be of other cross-sectional geometries such as square, rectangular, hex or other geometric configurations. Non-integrated rotatable fitting 200 consists of a non-integrated fitting shank 205 with threads if serving as a stud and rough or machined surface if serving as a shaft or other fastener.
Substrate workpiece 500 can be of various geometries such as flat, round, or other geometric configurations. Substrate workpiece 500 is generally stationary and clamped in place, but can be circular and moved in an axial direction in certain friction welding conditions and configurations.
Referring to FIGS. 2-5, non-integrated rotatable fitting 200 is depicted as a stud with a non-integrated fitting threads 201. A non-integrated fitting proximal end 202 is inserted into friction welder apparatus workpiece fitting collett 100. A non-integrated fitting distal end 203 is generally shaped with an angle to flat section to accommodate the friction welding process, but could be other type shaped geometry. Non-integrated fitting proximal end 202 will be designed to meet the geometric shape and locking requirements of a specific friction welder apparatus workpiece fitting collett 100.
Friction welding fusion enhancer apparatus 300 has a enhancer adapter internal threads 301 which permits threading friction welding fusion enhancer apparatus 300 onto threaded type non-integrated rotatable fitting 200 located where a enhancer adapter reaction surface 302 is located in line with a non-integrated fitting external peripheral edge 204 of non-integrated rotatable fitting 200 located at non-integrated fitting distal end 203, but may be formed to other geometric configurations that best serve the requirements of a specific friction welding application. Enhancer adapter reaction surface 302 is also designed to have minimum surface area contact with substrate workpiece 500 between the area of non-integrated fitting external peripheral edge 204 and a enhancer adapter external peripheral edge 304. At the completion of the friction welding process, enhancer adapter reaction surface 302 is rotated and urged against substrate workpiece 500 at the area adjacent to a enhancer adapter interface gap 303 to generate heat and plastisized material beyond non-integrated fitting external peripheral edge 204.
Enhancer adapter reaction surface 302 may extends out past area of non-integrated fitting threads 201 major diameter, from non-integrated fitting external peripheral edge 204, at non-integrated fitting distal end 203, to enhancer adapter external peripheral edge 304 to a distance of approximately 50% of non-integrated fitting shank 205 diameter and is generally shaped at the same angle of non-integrated fitting distal end 203, but may be shaped differently. Enhancer adapter interface gap 303 is designed to provide isolation between friction welding fusion enhancer apparatus 300 and non-integrated rotatable fitting 200, specifically at the area of non-integrated fitting external peripheral edge 204. Enhancer adapter interface gap 303 is designed to a width and depth nominally 10 to 40% +/- of non-integrated fitting shank 205 diameter. A enhancer adapter backup nut 305 with a enhancer adapter backup nut threads 306, as shown in FIG. 2, may be used to tighten against and secure friction welding fusion enhancer apparatus 300 onto non-integrated rotatable fitting 200 depending on the application requirements. Friction welding fusion enhancer apparatus 300 may also be secured to non-integrated rotatable fitting 200 by one or more of a enhancer adapter set screw 307 as shown in FIG. 5. Other anchoring techniques could include lock type nuts, pins and other such devices (not shown) all of which secure friction welding fusion enhancer apparatus 300 onto non-integrated rotatable fitting 200.
In another preferred embodiment and referring initially to FIGS. 6-9, of the drawings, in which like numerals indicate like elements throughout the several views, the friction welding fusion enhancer apparatus 300 is set forth in FIGS. 6-9, and generally includes a standard or specific friction welder apparatus workpiece fitting collett 100 (included for reference--not shown), friction welding fusion enhancer apparatus 300, which is, in this embodiment, machined integral with the friction welding rotatable workpiece, a friction welder break-away rotatable fitting 400, which is, in itself, a rotatable workpiece with a friction welding fusion enhancer apparatus 300, made part thereof, but can be removed after the friction weld process has been completed. Friction welding fusion enhancer apparatus 300 can be fabricated as an adapter, as was previously described above, or be made an integral part of a friction welding fitting as will be described in the other preferred embodiments below. Also included is substrate workpiece 500 (included for reference--not shown), which could be stationary or rotatable. Friction welder break-away rotatable fitting 400, friction welding fusion enhancer apparatus 300 and substrate workpiece 500 can be made from a number of materials, each similar to or dissimilar from the other, depending on the application. Such materials include, but are not limited to stainless steel, carbon steel, aluminum alloys, brass, titanium, zirconium alloys and other alloys. These components are integrally coupled in a manner described below.
Referring to FIGS. 6-9, friction welder apparatus workpiece fitting collett 100 (see FIG. 1) could include colletts from any type friction welder, portable or stationary type, where such colletts could hold friction welder break-away rotatable fitting 400 by mechanically tightening and clamping against the friction welder break-away rotatable fitting 400, or hold the friction welder break-away rotatable fitting 400 by threads, or hold the friction welder break-away rotatable fitting 400 by means of a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal type clamping mechanism, which tightens up against friction welder break-away rotatable fitting 400 when rotation begins. There are many other various geometries which are designed to hold the rotatable workpiece during the friction welding process. The collett is part of a friction welder apparatus and is rotated or otherwise moved to create friction and, at the same time, the collett is urged toward the stationary workpiece to complete the friction welding process.
The friction welder break-away rotatable fitting 400, for a specific application, is designed to fit a specific collett and is inserted into the friction welder apparatus workpiece fitting collett 100 in a secure fashion to permit friction welding of friction welder break-away rotatable fitting 400 to a substrate workpiece 500, which can be made of similar or dissimilar materials.
The friction welder break-away rotatable fitting 400 is a friction weld fitting made integral with a similar type of friction welding fusion enhancer apparatus 300 generally described in the first preferred embodiment herein, but with changes required for an integral structure that can be removed after the friction welding fusion bond has been completed. Friction welder break-away rotatable fitting 400 and friction welding fusion enhancer apparatus 300 integral component are generally round in geometry, but can be of other cross-sectional geometries such as square, rectangular, hex or other geometric configurations. Friction welder break-away rotatable fitting 400 consists of a shank with threads if serving as a stud and rough or machined surface if serving as a shaft or other fastener, or of another configuration. Substrate workpiece 500 can be of various geometries such as flat, round, or other geometric configurations. Substrate workpiece 500 is generally stationary and clamped in place, but can be circular and moved in an axial direction in certain friction welding conditions and configurations.
Referring to FIGS. 3-4, friction welder break-away rotatable fitting 400 is depicted as a stud with a break-away fitting threads 401. A break-away fitting proximal end 402 is inserted into friction welder apparatus workpiece fitting collett 100. A break-away fitting distal end 403 is generally shaped with an angle to flat section to accommodate the friction welding process, but could be of other type shaped geometry. Break-away fitting proximal end 402 will be designed to meet the geometric shape and locking requirements of a specific friction welder apparatus workpiece fitting collett 100.
Friction welder break-away rotatable fitting 400, and integral friction welding fusion enhancer apparatus 300, has at its break-away fitting distal end 403, a integrated enhancer reaction surface 309 which extends out radially, past break-away fitting distal end 403, from a integrated enhancer interface gap 308 out to a integrated enhancer external peripheral edge 310. Integrated enhancer interface gap 308, whose width and depth is nominally 10 to 40% +/- of a break-away fitting shank 405 diameter. Integrated enhancer reaction surface 309 may extend out past area of break-away fitting threads 401 major diameter to integrated enhancer external peripheral edge 310 from a break-away fitting external peripheral edge 404, to a distance of approximately 50% of break-away fitting shank 405 diameter. The actual dimensions of integrated enhancer interface gap 308, integrated enhancer reaction surface 309 and integrated enhancer external peripheral edge 310 will vary depending on the application and materials used.
At the top of friction welding fusion enhancer apparatus 300 configuration opposite break-away fitting distal end 403, there is a integrated enhancer break-away groove 311 which allows for removal of friction welding fusion enhancer apparatus 300 configuration from friction welder break-away rotatable fitting 400. The removal point of friction welding fusion enhancer apparatus 300 configuration that was originally made part of friction welder break-away rotatable fitting 400 is further facilitated by a integrated enhancer break-away slots 312, machined outward toward integrated enhancer external peripheral edge 310, starting from the major diameter of break-away fitting threads 401 or break-away fitting shank 405 diameter at a point identified as break-away fitting external peripheral edge 404 or other geometric configuration at the same general location, if not threaded. Number, shape and size of integrated enhancer break-away slots 312 may vary from application to application.
Integrated enhancer reaction surface 309 provides additional contact surface to generate greater surface area heat with substrate workpiece 500. During the fusion process, friction welder break-away rotatable fitting 400 is rotated and urged toward substrate workpiece 500 to create friction and complete the friction welding process. The contact of integrated enhancer reaction surface 309 to stationary substrate workpiece 500 is essential for achieving greater strengths and more even temperature strata during the friction welding process, so as to distribute greater temperature in desired fusion bonding area, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece.
Integrated enhancer break-away groove 311 is machined to provide a thin section between its bottom and integrated enhancer interface gap 308, so when combined with integrated enhancer break-away slots 312, friction welding fusion enhancer apparatus 300 can be easily removed once the friction welding of friction welder break-away rotatable fitting 400 to substrate workpiece 500 has been completed and removed from friction welder break-away rotatable fitting 400 shank at a point where integrated enhancer interface gap 308 meets break-away fitting distal end 403. The removal of expended friction welding fusion enhancer apparatus 300 will, with proper techniques, permit a clean shank with no permanent build-up of the residual plastisized material which would normally be present in increasing the fusion area to the full cross-section
Referring to FIG. 9, another alternate design concept of the friction welding fusion enhancer apparatus 300 made integral with friction welder break-away rotatable fitting 400 is inserted into friction welder apparatus workpiece fitting collett 100 in the same manner as described above for a specific application. Break-away fitting threads 401, break-away proximal end 402, break-away fitting distal end 403 and break-away fitting shank 405 diameter are similar in design and applications as described above for friction welder break-away rotatable fitting 400. The interface at break-away fitting distal end 403 has been changed to include a integrated enhancer interface reaction ridge 313 at the location where break-away fitting external peripheral edge 404 previously existed. Additionally, integrated enhancer break-away groove 311 has been replaced with a integrated enhancer break-away deep groove 314 which provides for a thin cross section between its bottom and integrated enhancer interface reaction ridge 313 at the break-away fitting distal end 403 interface with friction welding fusion enhancer apparatus 300. Integrated enhancer reaction surface 309 continues out to integrated enhancer external peripheral edge 310 as described above. Integrated enhancer break-away slots 312, of the type illustrated in FIGS. 7-8, may or may not be included in this alternate concept. The shape, size, and arrangement of integrated enhancer break-away slots 312, integrated enhancer interface reaction ride, and integrated enhancer break-away deep groove 314 may vary from application to application.
Integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309 provide additional contact surface to generate greater surface area heat with substrate workpiece 500. During the fusion process, friction welder break-away rotatable fitting 400 is rotated and urged toward substrate workpiece 500 to create friction and complete the friction welding process. The contact of integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309 to stationary substrate workpiece 500 is essential for achieving greater strengths and more even temperature strata during the friction welding process, so as to distribute greater temperature in desired fusion bonding area, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece. The integrated enhancer interface reaction ridge 313 and integrated enhancer break-away deep groove 314 should be designed so that the material cross-section area between these two elements is such that the material is expended during the friction welding fusion bonding process to the extent that friction welding fusion enhancer apparatus 300 can easily be removed, with proper techniques, so as to permit a clean shank with no permanent build-up of the residual plastisized material which would normally be present in increasing the fusion area to the full cross-section
OPERATION
Operation of friction welding fusion enhancer apparatus 300 is governed by the particular friction welder apparatus and, specifically, the control of speed and axial force provided at the point where the rotatable friction welding fitting is installed in a friction welder apparatus workpiece fitting collett 100. Prior to commencing the use of the friction welding fusion enhancer apparatus 300, the operator must determine if it is more desirable to utilize a non-integrated rotatable fitting 200 or custom designed friction welder break-away rotatable fitting 400. The operator's choice will depend on the particular application.
Considering using the first preferred embodiment, the operator made the decision to install non-integrated rotatable fitting 200 and install a threaded non-integrated fitting shank 205 or slip on friction welding fusion enhancer apparatus 300 of either the threaded type with enhancer adapter internal threads 301, backed up with enhancer adapter back-up nut 305 with enhancer adapter backup nut threads 306 or mechanically secured type such as secured by enhancer adapter set screw 307 on non-integrated fitting shank 205. The operator, in the case of a threaded device, will thread friction welding fusion enhancer apparatus 300 via enhancer adapter internal threads 301 on to non-integrated rotatable fitting 200 until enhancer adapter reaction surface 302 is located in line with non-integrated fitting external peripheral edge 204 of non-integrated rotatable fitting 200 located at non-integrated fitting distal end 203.
In considering the installation of a slip-on friction welding fusion enhancer apparatus 300, the operator will slide friction welding fusion enhancer apparatus 300 over non-integrated fitting threads 201 or non-integrated fitting shank 205, if not threaded and onto non-integrated rotatable fitting 200, until enhancer adapter reaction surface 302 is located in line with non-integrated fitting external peripheral edge 204 of non-integrated rotatable fitting 200 non-integrated fitting distal end 203. The operator will then secure friction welding fusion enhancer apparatus 300 to non-integrated rotatable fitting 200 with enhancer adapter set screw 307 or other type of mechanical fastener.
The operator then installs non-integrated rotatable fitting 200 non-integrated fitting proximal end 202 into friction welder apparatus workpiece fitting collett 100. The design of friction welder apparatus workpiece fitting collett 100 could include colletts of various designs from any type friction welder, portable or stationary type, where such colletts could hold a non-integrated rotatable fitting 200 by mechanically tightening and clamping against the non-integrated rotatable fitting 200, or hold the non-integrated rotatable fitting 200 by threads, or hold the non-integrated rotatable fitting 200 by means of a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal type clamping mechanism which tightens up against non-integrated rotatable fitting 200 when rotation begins. There are many other various geometries which are designed to hold the rotatable workpiece during the friction welding process. The collett is part of a friction welder apparatus and is rotated or otherwise moved to create friction, and at the same time, the collett is urged toward the stationary workpiece to complete the friction welding process.
In operation, non-integrated rotatable fitting 200, installed in friction welder apparatus workpiece fitting collett 100, and friction welding fusion enhancer apparatus 300, securely attached to non-integrated rotatable fitting 200 in either a threaded manner with non-integrated fitting threads 201, or slip on manner described above, will be rotated and urged toward substrate workpiece 500 to complete the friction welding process.
After the friction welding process has started, on initial contact of the welding surfaces, there is a "burn-off" phase which removes foreign materials from contact area both workpieces, (where the workpiece contact areas are defined as non-integrated rotatable fitting 200 non-integrated fitting distal end 203, contact area of friction welding fusion enhancer apparatus 300 enhancer adapter reaction surface 302 and contact area of substrate workpiece 500). The "burn-off" phase, is immediately followed, in an outward radial direction, by an "upset" phase where specific defined contact areas of both workpieces are turned to a plastic condition causing the establishment of a flux of hot metal due to the relative rotation and high axial pressure urging the two workpieces together, caused by resistive friction between the workpieces. After automatic or operator shutdown of the rotation of the rotatable workpiece, there is a "forging" phase where axial pressure is maintained between the workpieces until the plastisized material cools and the weld fuses during "fusion bonding" phase.
The friction welder will be programmed to stop so that fusion extends out to non-integrated fitting external peripheral edge 204, thereby achieving greater strengths and more even temperature strata during the friction welding process, so as to distribute greater temperature in desired fusion bonding area, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece. It is believed that the more even and extended fusion area is achieved because enhancer adapter reaction surface 302, out to enhancer adapter external peripheral edge 304, becomes extremely hot and causes the substrate workpiece 500 fusion area to become plastisized over a greater area and out to enhancer adapter interface gap 303, thus permitting non-integrated rotatable fitting 200 to fuse to substrate workpiece 500 out to its non-integrated fitting external peripheral edge 204, rather than a smaller fusion area as would be achieved without the use of friction welding fusion enhancer apparatus 300. Considering using the second preferred embodiment, the operator made the decision to install friction welder break-away rotatable fitting 400 with its integrated friction welding fusion enhancer apparatus 300. There are no adjustments to be made by the operator prior to installing friction welder break-away rotatable fitting 400.
In considering the installation of an integrated friction welding fusion enhancer apparatus 300, the operator will install friction welder break-away rotatable fitting 400 into friction welder apparatus workpiece fitting collett 100. The design of friction welder apparatus workpiece fitting collett 100 could include colletts of various designs from any type friction welder, portable or non-movable stationary type, where such colletts could hold a friction welder break-away rotatable fitting 400 by mechanically tightening and clamping against the friction welder break-away rotatable fitting 400, or hold the friction welder break-away rotatable fitting 400 by break-away fitting threads 401 located at break-away fitting proximal end 402, or hold the friction welder break-away rotatable fitting 400 by means of a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal type clamping mechanism which tightens up against friction welder break-away rotatable fitting 400 when rotation begins. There are many other various geometries which are designed to hold the rotatable workpiece during the friction welding process. The collett is part of a friction welder apparatus and is rotated or otherwise moved to create friction, and at the same time, the collett is urged toward the stationary workpiece to complete the friction welding process.
In operation, friction welder break-away rotatable fitting 400 break-away fitting shank 405 is installed in friction welder apparatus workpiece fitting collett 100 with friction welding fusion enhancer apparatus 300, securely and integrally attached to friction welder break-away rotatable fitting 400. Friction welder break-away rotatable fitting 400, securely installed in either a threaded or slip on manner described above, will be rotated and urged toward substrate workpiece 500 to create friction and complete the friction welding process.
After the friction welding process has started, on initial contact of the welding surfaces, there is a "burn-off" phase which removes foreign materials from contact area on both workpieces, (where the workpiece contact areas are defined as friction welder break-away rotatable fitting 400 break-away fitting distal end 403, contact area of friction welding fusion enhancer apparatus 300 integrated enhancer reaction surface 309 and contact area of substrate workpiece 500). The "burn-off" phase, is immediately followed, in an outward radial direction, by an "upset" phase where specific defined contact areas of both workpieces are turned to a plastic condition, causing the establishment of a flux of hot metal due to the relative rotation and high axial pressure urging the two workpieces together, caused by resistive friction between the workpieces. After automatic or operator shutdown of the rotation of the rotatable workpiece, there is a "forging" phase where axial pressure is maintained between the workpieces until the plastisized material cools and the weld fuses during "fusion bonding" phase.
The friction welder will be programmed to stop, so that fusion extends out to break-away fitting external peripheral edge 404, thereby achieving greater strengths and more even temperature strata during the friction welding process, so as to distribute greater temperature in desired fusion bonding area at the break-away fitting distal end 403 area and out to and including break-away fitting external peripheral edge 404, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece.
The more even and extended fusion area is achieved because integrated enhancer reaction surface 309 become extremely hot and causes the substrate workpiece 500 fusion area to become plastisized over a greater area and out to integrated enhancer interface gap 308, thus permitting friction welder break-away rotatable fitting 400 to fuse to substrate workpiece 500 out to break-away fitting external peripheral edge 404, rather than a smaller fusion area as would be achieved without the use of friction welding fusion enhancer apparatus 300.
Once the friction welding of friction welder break-away rotatable fitting 400 is completed and the friction welder operation has ceased, the integral friction welding fusion enhancer apparatus 300 will then be broken away and removed from friction welder break-away rotatable fitting 400 by severing friction welding fusion enhancer apparatus 300 from the integral structure at integrated enhancer interface gap 308, integrated enhancer break-away groove 311 and integrated enhancer break-away slots 312 out to integrated enhancer external peripheral edge 310, all located outside of break-away fitting distal end 403 and break-away fitting shank 405.
Now in considering using the alternate design of the second preferred embodiment, the operator made the decision to install friction welder break-away rotatable fitting 400 with its integrated friction welding fusion enhancer apparatus 300. Again, there are no adjustments to be made by the operator prior to installing friction welder break-away rotatable fitting 400. The operator will install friction welder break-away rotatable fitting 400 into friction welder apparatus workpiece fitting collett 100. As aforementioned, the design of friction welder apparatus workpiece fitting collett 100 could include colletts of various designs from any type friction welder, portable or non-movable stationary type, where such colletts could hold a friction welder break-away rotatable fitting 400 by mechanically tightening, clamping or threading, or hold the friction welder break-away rotatable fitting 400 by means of a slip-and lock arrangement, either direct mechanical linkage or by some sort of centrifugal type clamping mechanism which tightens up against friction welder break-away rotatable fitting 400 when rotation begins. There are many other various geometries which are designed to hold the rotatable workpiece during the friction welding process. The collett is part of a friction welder apparatus and is rotated or otherwise moved to create friction, and at the same time, the collett is urged toward the stationary workpiece to complete the friction welding process.
In operation, friction welder break-away rotatable fitting 400 break-away fitting shank 405 is installed in friction welder apparatus workpiece fitting collett 100 with friction welding fusion enhancer apparatus 300, securely attached to friction welder break-away rotatable fitting 400. Friction welder break-away rotatable fitting 400 is securely installed in either a threaded or slip on manner described above, and will be rotated and urged toward substrate workpiece 500 to create friction and complete the friction welding process.
After the friction welding process has started on initial contact of the welding surfaces, there is a "burn-off" phase which removes foreign materials from contact area on both workpieces, (where the workpiece contact areas are defined as friction welder break-away rotatable fitting 400 break-away fitting distal end 403, contact area of friction welding fusion enhancer apparatus 300, integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309 and contact area of substrate workpiece 500). The "burn-off" phase, is immediately followed, in an outward radial direction, by an "upset" phase where specific defined contact areas of both workpieces are turned to a plastic condition causing the establishment of a flux of hot metal due to the relative rotation and high axial pressure urging the two workpieces together caused by resistive friction between the workpieces. After automatic or operator shutdown of the rotation of the rotatable workpiece, there is a "forging" phase where axial pressure is maintained between the workpieces until the plastisized material cools and the weld fuses during "fusion bonding" phase.
The friction welder will be programmed to stop, so that fusion extends past integrated enhancer interface reaction ridge 313, thereby achieving greater strengths and more even temperature strata during the friction welding process, so as to distribute greater temperature in desired fusion bonding area at the break-away fitting distal end 403 area and out to and including integrated enhancer interface reaction ridge 313 which is located near break-away fitting shank 405 break-away fitting external peripheral edge 404, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece.
The more even and extended fusion area is achieved because integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309, out to integrated enhancer external peripheral edge 310, becomes extremely hot and causes the substrate workpiece 500 fusion area to become plastisized over a greater area and out to, or beyond, integrated enhancer interface reaction ridge 313, thus permitting friction welder break-away rotatable fitting 400 to fuse to substrate workpiece 500 out to a distance equal break-away fitting shank 405 break-away fitting external peripheral edge 404, at the break-away fitting distal end 403, rather than a smaller fusion area as would be achieved without the use of friction welding fusion enhancer apparatus 300.
In this alternate operation, the integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309 provides additional contact surface to generate greater surface area heat with substrate workpiece 500. During the fusion process, friction welder break-away rotatable fitting 400 is rotated and urged toward substrate workpiece 500 to create friction and complete the friction welding process. The contact of integrated enhancer interface reaction ridge 313 and integrated enhancer reaction surface 309 to stationary substrate workpiece 500 generates greater temperature over an extended fusion area and assures a more even temperature strata during the friction welding process, so as to eliminate weak areas at the peripheral areas of the rotatable workpiece. The integrated enhancer interface reaction ridge 313 and integrated enhancer break-away deep groove 314, designed with a limited material cross-section area between these two elements, permits material to be expended during the friction welding fusion bonding process to the extent that friction welding fusion enhancer apparatus 300 can easily be removed, with proper techniques, so as to permit a clean shank with no permanent build-up of the residual plastisized material which would normally be present in increasing the fusion area to the full cross-section.
From the foregoing description, those skilled in the art will appreciate that all of the objectives of the present invention are realized. The friction welding fusion enhancer apparatus 300 could be made an integral part of or adapted to the substrate workpiece 500, whether substrate workpiece be stationary or rotatable. The friction welding fusion enhancer apparatus 300 can also be made from different materials than the rotatable fitting workpiece, whether or not friction welding fusion enhancer apparatus 300 is an adapter as described in the preferred embodiment shown with non-integrated rotatable fitting 200 or an integral part with a rotatable friction welder break-away rotatable fitting 400. Prototype test results, completed by the inventor, have shown the present invention effective in enhancing friction weld fusion bonding strength, while permitting significant reduction of plastisized material build-up.
Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments, illustrated and described. Rather, it is intended that the scope of the invention be determined by the appended claims and their equivalents.
Although particular detailed embodiments of the apparatus and method have been described herein, it should be understood that the invention is not restricted to the details of the preferred embodiment. Many changes in design, composition, configuration and dimensions are possible without departing from the spirit and scope of the instant invention.
|
A friction welding fusion enhancer apparatus. This invention relates generally to an apparatus and method for increasing the fusion area of a rotatable workpiece (stud, shaft or other) to be friction welded to a substrate of either similar or dissimilar materials or two circular shafts that are to be friction welded together by use of an apparatus that can be removable from the stud, shaft or other weldable devices after the stud is friction welded to the substrate, while limiting the build-up of plastisized matter around the peripheral edge of the rotatable workpiece. It is envisioned the invention disclosed herein could be adaptable to a wide range of friction welding apparatuses since the apparatus disclosed herein could be adapted to most friction welder rotatable workpieces. The friction welding fusion enhancer apparatus includes the following integrally coupled components: reaction surface area, peripheral edge, engagement means and rotatable workpiece.
| 1
|
This is a continuation of application Ser. No. 09/553,000, filed Apr. 19, 2000, now U.S. Pat. No. 6,350,283, incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to interbody spinal implants preferably adapted for placement in pairs side by side to either side of the midline with or without a space therebetween into a space created across the height of a disc space and between two adjacent vertebral bodies, after the removal of damaged spinal disc material, for the purpose of correcting spinal disease at that interspace. The spinal implants comprise of cortical bone either in a form such as a material that may naturally be available from a body; or as a composite material of cortical bone in particles or spindles, and the like in a resorbable plastic, ceramic, or other so long as it is structurally suitable for the intended purpose. The implants are adapted such that fusion occurs at least in part through the implants themselves.
2. Description of the Related Art
Surgical interbody spinal fusion generally refers to the methods for achieving a bridge of bone tissue in continuity between adjacent vertebral bodies and across the disc space to thereby substantially eliminate relative motion between the adjacent vertebral bodies. The term “disc space” refers to the space between adjacent vertebral bodies normally occupied by a spinal disc.
Spinal implants can have opposed upper and lower surfaces that are arcuate or non-arcuate transverse to the longitudinal axis of the implant along at least a portion of the length of the implant. Implants having arcuate opposed portions are adapted to be implanted across and beyond the height of the restored disc space, generally into a bore formed across the height of a disc space. Some of the advantages offered by implants with arcuate opposed portions include: 1) the installation of the implant into vascular bone made possible by the creation of a bore into the bone of the adjacent vertebral bodies; 2) the implant's geometric shape is easy to manufacturer 3) the implant can include external threads to facilitate insertion into the implantation space; and 4) the implant provides more surface area to contact the adjacent vertebral bodies, than would a flat surface. Some disadvantages associated with implants having arcuate opposed portions include: 1) the creation of a bore into the adjacent vertebral bodies to form the implantation space results in a loss of the best structural bone of the vertebral endplate; 2) the implant needs to have a larger cross section to fill the prepared implantation site which may be more difficult to install, especially from a posterior approach; and 3) the width of the implant is generally related to the height of the implant, so if the implant is for example a cylinder, then the width of the implant may be a limiting factor as to the height of the implant and therefore its possible usefulness.
Implants having non-arcuate upper and lower opposed portions may be impacted into a space resembling the restored disc space and need only be placed against a “decorticated endplate”. A decorticated endplate is prepared by a surgeon to provide access to the underlying vascular bone. Some of the advantages provided by implants having non-arcuate opposed portions include: 1) preserving the best bone in the endplate region; 2) the height of the implant is independent of its width; 3) the implant can be of a geometric shape and the opposed upper and lower surfaces can be flat; 4) the implant can be installed as modular unit; and 5) the implant can provide a broad surface contact. Some of the disadvantages provided by implants having non-arcuate opposed portions include: 1) the implants cannot be threaded in and must be impacted into the installation space; and 2) the recipient site may be more difficult to prepare.
Human vertebral bodies have a hard outer shell of compacted dense cancellous bone (sometimes referred to as the cortex) and a relatively softer, inner mass of cancellous bone. Just below the cortex adjacent the disc is a region of bone referred to herein as the “subchondral zone”. The outer shell of compact bone (the boney endplate) adjacent to the spinal disc and the underlying subchondral zone are together herein referred to as the boney “end plate region” and, for the purposes of this application, is hereby so defined. A circumferential ring of dense bone extends around the perimeter of the endplate region and is the mature boney successor of the “apophyseal growth ring”. This circumferential ring is formed of very dense bone and for the purposes of this application will be referred to as the “apophyseal rim”. For purposes of this application, the “apophyseal rim area” includes the apophyseal rim and additionally includes the dense bone immediately adjacent thereto. The spinal disc that normally resides between the adjacent vertebral bodies maintains the spacing between those vertebral bodies and, in a healthy spine, allows for the normal relative motion between the vertebral bodies.
FIG. 1 of the attached drawings shows a cross-sectional top plan view of a vertebral body V in the lumbar spine to illustrate the dense bone of the apophyseal rim AR present proximate the perimeter of the vertebral body V about the endplate region and an inner mass of cancellous bone CB. The structure of the vertebral body has been compared to a core of wet balsa wood encased in a laminate of white oak. The apophyseal rim AR is the best structural bone and is peripherally disposed in the endplate of the vertebral body.
FIG. 2 is a top plan view of a fourth level lumbar vertebral body V shown in relationship anteriorly with the aorta and vena cava (collectively referred to as the “great vessels” GV). FIG. 3 is a top plan view of a first sacral level vertebral body V shown in relationship anteriorly with the iliac arteries and veins referred to by the designation “IA-V”. Because of the location of these fragile blood vessels along the anterior aspect of the lumbar vertebrae, no hardware should protrude from between the vertebral bodies and into the great vessels GV and iliac arteries and veins IA-V.
Fusion implants preferably have a structure designed to promote fusion of the adjacent vertebral bodies by allowing for the growth of bone through the implant from vertebral body to adjacent vertebral body. This type of implant is intended to remain indefinitely within the patient's spine unless made of a resorbable or bioresorbable material such as bone that can be biologically replaced in the body over time such that it need not be removed as it is replaced over time will no longer be there. Implants may be sized to have a width generally as great as the nucleus portion of the disc or as wide as the area between the limit lines LL as shown in FIG. 4 . There are at least two circumstances where the use of such a wide implant is not desirable. Under these circumstances, the use of a pair of implants each having a width less than one half the width of the disc space to be fused is preferred. The first circumstance is where the implants are for insertion into the lumbar spine from a posterior approach. Because of the presence of the dural sac within the spinal canal, the insertion of a full width implant in a neurologically intact patient could not be performed from a posterior approach. The second circumstance is where the implants are for endoscopic, such as laproscopic, insertion regardless of the approach as it is highly desirable to minimize the ultimate size cross-sectionally of the path of insertion.
The ability to achieve spinal fusion is inter alia directly related to the vascular surface area of contact over which the fusion can occur, the quality and the quantity of the fusion mass, and the stability of the construct. The overall size of interbody spinal fusion implants is limited, however, by the shape of the implants relative to the natural anatomy of the human spine. For example, if such implants were to protrude from the spine they might cause injury to one or more of the proximate vital structures including the large blood vessels or neurological structures.
FIG. 4 shows a top plan view of the endplate region of a vertebral body V with the outline of a related art implant A and implant 100 of one embodiment of the present invention installed, one on each side of the centerline of the vertebral body V. The length and width of related art implant A is limited by its configuration and the vascular structures anteriorly (in this example) adjacent to the implantation space. The presence of limiting corners LC on the implant precludes the surgeon from utilizing an implant of this configuration having both the optimal width and length because the implant would markedly protrude from the spine.
Related art implants also fail to maximally sit over the best structural bone, which is located peripherally in the apophyseal rim of the vertebral body and is formed of the cortex and dense subchondral bone. The configurations of previous implants do not allow for maximizing both the vital surface area over which fusion could occur and the area available to bear the considerable loads present across the spine. Previous implant configurations do not allow for the full utilization of the apophyseal rim bone and the bone adjacent to it, located proximate the perimeter of the vertebral body to support the implants at their leading ends and to maximize the overall support area and area of contact for the implants. The full utilization of this dense peripheral bone would be ideal.
Therefore, there is a need for an interbody spinal fusion implant having opposed portions for placement toward adjacent vertebral bodies that is capable of fitting within the outer boundaries of the vertebral bodies between which the implant is to be inserted and to maximize the surface area of contact of the implant and vertebral bone. The implant should achieve this purpose without interfering with the great vessels or neurological structures adjacent to the vertebrae into which the implant is to be implanted. There exists a further need for an implant that is adapted for placement more fully on the dense cortical bone proximate the perimeter of the vertebral bodies at the implant's leading end.
SUMMARY OF THE INVENTION
The present invention relates to a spinal implant formed or manufactured prior to surgery and provided fully formed to the surgeon for use in interbody fusion formed of bone. The implant is of a width preferably sized to be used in pairs to generally replace all or a great portion of all of the width of the nucleus portion of the disc. To that end, the width of the implant is less than half of the width of the disc space. Preferably, the implant generally has parallel side walls and is used where it is desirable to insert an implant of enhanced length without the leading lateral wall protruding from the spine.
The interbody spinal implant of the present invention is for placement between adjacent vertebral bodies of a human spine across the height of the disc space between those adjacent vertebral bodies. The implant preferably does not extend beyond the outer dimensions of the two vertebral bodies adjacent that disc space and preferably maximizes the area of contact of the implant with the vertebral bone. In a preferred embodiment, the implant has a leading end configured to conform to the anatomic contour of at least a portion of the anterior, posterior, or lateral aspects of the vertebral bodies depending on the intended direction of insertion of the implant, so as to not protrude beyond the curved contours thereof. The implant has an asymmetrical leading end modified to allow for enhanced implant length without the corner of the leading end protruding out of the disc space. As used herein, the phrase “asymmetrical leading end” is defined as the leading end of the implant lacking symmetry from side-to-side along the transverse axis of the implant when the leading end is viewed from a top elevation.
The configuration of the leading end of the implant of the present invention allows for the safe use of an implant of maximum length for the implantation space into which it is installed. Benefits derived from a longer length implant include, but are not limited to, providing a greater surface area for contacting the vertebral bodies and for carrying bone growth promoting materials at the implant surface, increasing the load bearing support area, increased stability, increased internal volume for holding fusion promoting material, and the ability to have a portion of the implant rest upon the apophyseal rim, the best structural bone of the vertebral endplate region. These fusion promoting and bone growth promoting materials may be bone, bone products, bone morphogenetic proteins, mineralizing proteins, genetic materials coding for the production of bone, or any other suitable material.
The spinal implant of the present invention may also include a trailing end opposite the leading end that is configured to conform to the anatomic contour of the anterior, posterior, or lateral aspects of the vertebral bodies, depending on the direction of insertion, so as not to protrude beyond the curved contours thereof. The present invention can benefit interbody spinal fusion implants having spaced apart non-arcuate opposed surfaces adapted to contact and support opposed adjacent vertebral bodies as well as implants having spaced apart arcuate opposed surfaces adapted to penetrably engage opposed vertebral bodies. As used herein, the term “arcuate” refers to the curved configuration of the opposed upper and lower portions of the implant transverse to the longitudinal axis of the implant along at least a portion of the implant's length.
In one embodiment of the present invention, an implant adapted for insertion from the posterior approach of the spine, and for achieving better, safe filling of the posterior to anterior depth of the disc space between two adjacent vertebral bodies, and for the possibility of having the leading end of the implant supported by the structurally superior more peripheral bone including the apophyseal rim and the bone adjacent to it, includes opposed portions adapted to be oriented toward the bone of the adjacent vertebral bodies, a leading end for inserting into the spine, and an opposite trailing end that may be adapted to cooperatively engage a driver. In the alternative, the implant may receive a portion of the driver through the trailing end to cooperatively engage the implant from within and/or at the implant trailing end. The leading end of this embodiment of the implant of the present invention is generally configured to conform to the natural anatomical curvature of the perimeter of the anterior aspect of the vertebral bodies, so that when the implant is fully inserted and properly seated within and across the disc space the implant contacts and supports a greater surface area of the vertebral bone in contact with the implant to provide all the previously identified advantages. Moreover, at the election of the surgeon, the implant of the present invention is configured to be able to be seated upon the more densely compacted bone about the periphery of the vertebral endplates for supporting the load through the implant when installed in or across the height of the intervertebral space.
Related art bone ring implants where the implant is a circle, oval, or oblong have trailing ends that are either modified to be squared-off, or unmodified so as to remain a portion of a circle, an oval, or an oblong and have a medial side wall that is incomplete due to a portion of the medullary canal interrupting the side wall. The present invention implants may have an interior facing medial side wall adapted for placement medially within the disc space with the side wall intact and substantially in the same plane and an exterior facing lateral side wall opposite to the medial side wall and adapted for placement laterally. The implants of the present invention also have a mid-longitudinal axis between the medial and lateral side walls wherein the mid-longitudinal axis at the leading end extends forward further than the lateral side wall of the leading end while the medial side wall is not equal in length to the lateral side wall, but is greater in length.
In another embodiment of the present invention, an implant for insertion from the anterior approach of the spine and for achieving better filling of the anterior to posterior depth of the disc space has a leading end generally configured to better conform to the natural anatomical curvature of the perimeter of the posterior aspect of the vertebral bodies and does not protrude laterally.
In yet another embodiment of the present invention, the implant has a trailing end that is either asymmetric or symmetric from side-to-side along the transverse axis of the implant. The trailing end may be adapted to conform to the anatomical contours of the anterior or posterior aspects of the vertebral bodies. For example, an implant for insertion from the posterior or anterior approach of the spine has a leading end that is generally configured to better conform to the natural anatomical curvature of at least one of the perimeter of the anterior and posterior aspects, respectively, of the vertebral bodies and a trailing end that is generally configured to conform to the natural anatomical curvature of the opposite one of the posterior and anterior aspects, respectively, of the vertebral bodies depending on the intended direction of insertion and that does not protrude laterally from the vertebral bodies. When the implant is fully seated and properly inserted within and across the disc space, the surface area of the vertebral bone in contact with the implant is more fully utilized.
As another example, an implant in accordance with the present invention for insertion from a translateral approach to the spine and across the transverse width of the vertebral bodies has a leading end that is generally configured to better conform to the natural anatomical curvature of the perimeter of at least one of the lateral aspects, respectively, of the vertebral bodies. The implant also may have a trailing end that is generally configured to conform to the natural anatomical curvature of the opposite one of the lateral aspects, respectively, of the vertebral bodies depending on the intended direction of insertion. Implants for insertion from a translateral approach and methods for inserting implants from a translateral approach are disclosed in Applicant's U.S. Pat. Nos. 5,860,973 and 5,772,661, respectively, incorporated by reference herein.
The implant of the present invention is better able to sit upon the dense compacted bone about the perimeter of the vertebral bodies of the vertebral endplate region for supporting the load through the implant when installed in the intervertebral space. The spinal fusion implants of the present invention has at least one opening therethrough from the upper vertebral body contacting surface through to the lower vertebral body contacting surface to permit for the growth of bone in continuity from adjacent vertebral body to adjacent vertebral body through the implant for fusion across the disc space.
For any of the embodiments of the present invention described herein, the implant preferably includes protrusions or surface roughenings for engaging the bone of the vertebral bodies adjacent to the implant. In a preferred embodiment, the material of the implant is bone that is either in a naturally occurring state, or a composite material made of bone particles. In a naturally occurring state, the implant can be manufactured from a piece of bone obtained from a major long bone or other suitable source and can include bone dowels and diaphyseal bone rings, for example. Alternatively, the implants can be manufactured from a composite of bone made up of cortical fibers, bone filaments, or bone particles, as examples, and at least a second substance preferably bioresorbable such as a plastic or ceramic suitable for the intended purpose. The composite material could be machineable, or moldable, into the desired shape.
Bones offers the advantages of an appropriate modulus of elasticity and strength for the prescribed use, the capacity to be bioactive, including being osteoconductive, osteoinductive, osteogenic, and to more generally provide a good substrate for the formation of new bone as fusion occurs. Further, the bone material being bioabsorable is replaced by the patient's own bone over time preventing stress shielding and leading to the eventual elimination of any foreign body from the implantation site.
In addition to bone, the implants may further include other osteogenic materials such as bone morphogenetic proteins, or other chemical compounds, or genetic material coding for the production of bone, the purpose of which is to induce or otherwise encourage the formation of bone or fusion. In addition to bone, where the implants are of a composite material, they could comprise of a bioresorbable material including, but not limited to various ceramics or plastics. Suitable plastics may include those comprising lactides, galactides, glycolide, capronlactone, trimethylene carbonate, dioxanone, in various polymers and/or combinations.
Materials other than bone for use as the base material used to form the implant are specifically excluded from the definition of implant materials for the purpose of this application. The implants may be adapted to receive fusion promoting substances within them such as cancellous bone, bone derived products, or others.
It is appreciated that the features of the implant of the present invention as described herein are applicable to various embodiments of the present invention including implants having non-arcuate or arcuate upper and lower opposed portions adapted to be oriented toward the bone of the adjacent vertebral bodies.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a horizontal cross-section through a boney endplate region of a vertebral body.
FIGS. 2-3 are top plan views of the fourth lumbar and first sacral vertebral bodies, respectively, in relationship to the blood vessels located anteriorly thereto.
FIG. 4 is a top plan plan view of an endplate region of a vertebral body with a prior art implant on the left side of the center line and an implant in accordance with one embodiment of the present invention on the right side of the centerline inserted from the posterior aspect of the spine.
FIG. 5 is a side perspective view of the outline of an implant in accordance with one embodiment of the present invention.
FIG. 6 is a partial enlarged fragmentary view along line 6 — 6 of FIG. 5 .
FIG. 7 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant in accordance with one embodiment of the present invention inserted from the posterior aspect of the vertebral body.
FIG. 8 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant in accordance with one embodiment of the present invention inserted from the anterior aspect of the vertebral body.
FIG. 9 is a top plan view of an implant in accordance with one embodiment of the present invention illustrating the mid-longitudinal axis and a plane bisecting the mid-longitudinal axis along the length of the implant.
FIG. 10 is a top plan view of a lumbar vertebral body in relationship to the blood vessels located proximate thereto and an implant having arcuate upper and lower opposed portions in accordance with an embodiment of the present invention inserted from the posterior aspect of the vertebral body.
FIG. 11 is a trailing end view of a spinal implant shown in FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4 shows an embodiment of the present invention comprising an interbody spinal implant generally referred by the numeral 100 , inserted in the direction of arrow P from the posterior aspect of a vertebral body V on one side of the centerline M in the lumbar spine. In a preferred embodiment of the present invention, the implant can be made of bone that is either in a naturally occurring state, or can be made of a composite material comprising bone particles. In a naturally occurring state, the implant can be manufactured from a piece of bone obtained from a major long bone or other suitable source and can include bone dowels and diaphyseal bone rings, for example. Alternatively, the implants can be manufactured from a composite of bone made up of cortical fibers, bone filaments, bone particles, as examples. In addition to bone, the composite may also include a material which may or may not be bioactive and/or bioresorbable such as a plastic, ceramic, or other. Once formed, the bone composite implant could be machineable, or moldable, into the desired shape.
In addition to bone, the implants may further include other osteogenic materials such as bone morphogenetic proteins, or other chemical compounds, or genetic material coding for the production of bone, the purpose of which is to induce or otherwise encourage the formation of bone or fusion. In addition to bone, the implants could comprise a bioresorbable material including, but not limited to cortical bone, plastics and composite plastics. Suitable plastics may include those comprising lactides, glycolide, capronlactone, trimethylene carbonate, dioxanone in various polymers and/or combinations.
Implant 100 has a leading end 102 for insertion into the disc space and an opposite trailing end 104 . In a preferred embodiment, leading end 102 is configured to not extend beyond the outer dimensions of the two vertebral bodies adjacent the disc space proximate leading end 102 after implant 100 is installed, to maximize the area of contact of the implant with the vertebral bone. Leading end 102 could be described as being generally configured to generally conform to at least a portion of the natural anatomical curvature of the aspect of the vertebral bodies adjacent the disc space proximate leading end 102 after implant 100 is installed. The general configuration of leading end 102 is further described in connection with FIG. 9 below.
As shown in FIGS. 7 and 8, depending on the direction of insertion, for example, when implant 100 is installed in the direction of arrow P from the posterior aspect of the vertebral body V, leading end 102 a is adapted to conform to at least a portion of the anterior aspect of the vertebral body V. When implant 100 is installed in the direction of arrow A from the anterior aspect of vertebral body V, leading end 102 b is adapted to conform to at least a portion of the posterior aspect of vertebral body V. Trailing end 104 may be symmetrical or asymmetrical from side-to-side along the transverse axis of the implant and can conform to at least a portion of the natural curvature of the aspect of vertebral body V opposite to leading end 102 . Trailing end 104 may or may not be configured to conform to the aspect of vertebral body V proximate trailing end 104 after implant 100 is installed. Trailing end 104 need only have a configuration suitable for its intended use in the spine.
As shown in FIGS. 5 and 6, implant 100 has opposed portions 106 and 108 that are adapted to contact and support adjacent vertebral bodies when inserted across the intervertebral space. In this embodiment, opposed portions 106 , 108 have a non-arcuate configuration transverse to the longitudinal axis of implant 100 along at least a portion of the length of implant 100 . Opposed portions 106 , 108 are spaced apart and connected by an interior side wall 112 and an exterior side wall 114 opposite interior side wall 112 . Interior side wall 112 is the portion of implant 100 adapted to be placed toward another implant when implant 100 is inserted in pairs into the disc space between the adjacent vertebral bodies to be fused. Interior side wall 112 is not the internal surface of a hollow interior of implant 100 . Exterior side wall 114 is adapted to be placed into the disc space nearer to the perimeter of the vertebral bodies than interior side wall 112 . Side walls 112 , 114 are preferably continuous from leading end to trailing end. Sidewalls 112 , 114 may also include at least one opening for permitting for the growth of bone therethrough.
Preferably, each of the opposed portions 106 , 108 have at least one opening 110 in communication with one another to permit for the growth of bone in continuity from adjacent vertebral body to adjacent vertebral body and through implant 100 . Opening 110 is preferably a through-hole with a maximum cross-sectional dimension greater than 0.5 mm between interior side wall 112 and exterior side wall 114 passing completely through the implant and is preferably adapted to hold bone growth promoting material for permitting for the growth of bone from vertebral body to vertebral body through the implant. The perimeter of the through-hole is preferably continuous and uninterrupted. Implant 100 may further be hollow or at least in part hollow. Implant 100 may also include surface roughenings on for example, at least a portion of opposed portions 106 , 108 for engaging the bone of the adjacent vertebral bodies.
As illustrated in FIG. 9, implant 100 has a mid-longitudinal axis MLA along its length. Mid-longitudinal axis MLA is bisected by a plane BPP perpendicular to and bisecting the length of implant 100 along the mid-longitudinal axis MLA. Implant 100 has a first distance as measured from point C at leading end 102 to bisecting perpendicular plane BPP at point E that is greater than a second distance as measured from bisecting perpendicular plane BPP at point F to the junction of leading end 102 and exterior side wall 114 at point B. Implant 100 has a third distance as measured from point A at the junction of leading end 102 and interior side wall 112 to bisecting perpendicular plane BPP at point D that is greater than the second distance as measured from at point F to point B. While in the preferred embodiment as shown in FIG. 9, the third distance from points A to D is illustrated as being longer than the first distance from points C to E, the third distance can be equal to or less than the first distance. In a preferred embodiment, the first distance measured from points C to E is greater than the second distance measured from points B to F; the third distance measured from points A to D can be less than the first distance measured from points C to E; and the third distance measured from points A to D does not equal the second distance measured from points B to F.
In a preferred embodiment of the present invention, when implant 100 is inserted between two adjacent vertebral bodies, implant 100 is contained completely within the vertebral bodies so as not to protrude from the spine. Specifically, the most lateral aspect of the implanted implant at the leading end has been relieved, foreshortened, or contoured so as to allow the remainder of the implant to be safely enlarged so as to be larger overall than the prior implants without the leading end lateral wall protruding from the disc space. Although overall enlargement of the implant is a preferred feature of one embodiment of the present invention, it is not a requisite element of the invention.
While a preferred embodiment of the present invention has been illustrated and described herein in the form of an implant having non-arcuate upper and lower portions along a portion of the length of the implant, another preferred embodiment of the present invention as best shown in FIG. 10 includes an implant having arcuate upper and lower portions along at least a portion of the length of the implant. All of the features described in association with the non-arcuate embodiments are equally applicable to the arcuate embodiments of the present invention.
FIGS. 10-11 show two interbody spinal implants generally referred to by the numeral 200 , inserted in the direction of arrow P from the posterior aspect of a vertebral body V, one on either side of the centerline M in the lumbar spine. Implant 200 is non threaded and is configured for linear insertion into the disc space in a direction along the mid-longitudinal axis of implant 200 . Implant 200 has a leading end 202 for insertion into the disc space and an opposite trailing end 204 . In a preferred embodiment, leading end 202 is configured to not extend beyond the outer dimensions of the two vertebral bodies adjacent the disc space proximate leading end 202 after implant 200 is installed, to maximize the area of contact of the implant with the vertebral bone. Leading end 202 could be described as being generally configured to generally conform to at least a portion of the natural anatomical curvature of the aspect of the vertebral bodies adjacent the disc space proximate leading end 202 after implant 200 is installed. In a preferred embodiment, less than half of asymmetric leading end 202 is along a line perpendicular to the mid-longitudinal axis of the implant in a plane dividing the implant into an upper half and a lower half.
In a further preferred embodiment of either arcuate or non-arcuate implants, more than half of the leading end can be a contour that goes from the exterior side wall toward the mid-longitudinal axis of the implant in the plane dividing the implant into an upper half and a lower half. In another preferred embodiment of either arcuate or non-arcuate implants, the leading end includes a curve that extends from the exterior side wall beyond the mid-longitudinal axis of the implant. The more pronounced curve of the leading end of the implant of the present invention as compared to the chamfer of related art implants advantageously provides for closer placement of the implant's leading end to the perimeter of the vertebral body, without the limiting corner protruding therefrom, to more fully utilize the dense cortical bone in the perimeter of the vertebral bodies. The configuration of the implant of the present invention provides the use of an implant having a longer overall length as measured from leading end to trailing end for a better fill of the disc space.
Implant 200 has opposed portions 206 and 208 that are arcuate transverse to the longitudinal axis of implant 200 along at least a portion of the length of implant 200 and are adapted to contact and support adjacent vertebral bodies when inserted across the intervertebral space and into the vertebral bodies. Implant 200 can further include protrusions or surface roughenings such as ratchetings 220 for enhancing stability. Surface roughenings may also include ridges, knurling and the like.
The present invention is not limited to use in the lumbar spine and is useful throughout the spine. In regard to use in the cervical spine, by way of example, in addition to various blood vessels the esophagus and trachea also should be avoided.
Further, the implant of the present invention preferably includes non-arcuate opposed surface portions that are either generally parallel to one another along the length of the implant or in angular relationship to each other such that the opposed surfaces are closer to each other proximate one end of the implant than at the longitudinally opposite other. The spinal implant of the present invention allows for a variable surface, or any other configuration and relationship of the opposed surfaces.
Implant 100 may be adapted to cooperatively engage a driver instrument for installation of the implant into the recipient site. For example, in a preferred embodiment trailing end 104 may be configured to complementary engage an instrument for driving implant 100 .
While the exact contour and/or curvature of a particular vertebral body may not be known, the teaching of having the implant leading end be arcuate or truncated along one side (the lateral leading end) or from side to side so as to eliminate the length limiting lateral leading corner LC or the side wall or lateral aspect junction to the implant leading end is of such benefit that minor differences do not detract from its utility. Further, the range of describable curvatures may be varied proportionately with the size of the implants as well as their intended location within the spine and direction of insertion to be most appropriate and is easily determinable by those of ordinary skill in the art.
Generally for use in the lumbar spine, and where the leading end is a portion of a circle, then the arc of radius of the curvature of the leading end of the implant should be from 10-30 mm to be of greatest benefit, though it could be greater or less, and still be beneficial. The same is true for the cervical spine where the arc of radius is preferably 8-20 mm. While particular preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects.
While specific innovative features were presented in reference to specific examples, they are just examples, and it should be understood that various combinations of these innovative features beyond those specifically shown are taught such that they may now be easily alternatively combined and are hereby anticipated and claimed.
|
An interbody spinal implant is formed of cortical bone adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies. An asymmetrical leading end on the implant is adapted to sit upon the peripheral areas, such as the apophyseal rim and the apophyseal rim area, of the vertebral end plate region of the vertebral bodies without protruding therefrom. The asymmetrical leading end allows for the safe use of an implant of maximum length for the implantation space into which it is installed. The implant can also include an asymmetric trailing end adapted to sit upon the more peripheral areas of the vertebral end plate region of the vertebral bodies.
| 0
|
This is a Continuation-in-part application of U.S. patent application Ser. No. 352,496 filed Feb. 25, 1982, now U.S. Pat. No. 4,516,881.
DISCLOSURE STATEMENT
Reference is made to the following publications which provide information regarding the art of vertically moored platforms.
A. The Vertically Moored Platform, for Deepwater Drilling and Production; by M. Y. Berman, K. A. Blenkarn, and D. A. Dixon; OTC Paper #3049, Copyright 1978 Offshore Technology Conference; and
B. Motion, Fatigue and the Reliability of Characteristics of a Vertically Moored Platform; by P. A. Beynet, M. Y. Berman, and J. T. von Aschwege; OTC Paper #3304; Copyright 1978, Offshore Technology Conference.
Reference is also made to U.S. Pat. No. 4,127,005 issued Nov. 28, 1978, entitled: "Riser/Jacket Vertical Bearing Assembly for Vertically Moored Platform" and U.S. Pat. No. 4,130,995 issued Dec. 26, 1978, entitled: "VMP Riser Horizontal Bearing". U.S. Pat. Nos. 4,127,005 and 4,130,995 are assigned to the assignee of this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention lies in the field of vertically moored platforms (VMP) or other floating structures, for offshore, deepwater oil production which are connected to anchors in the sea floor by large diameter pipes commonly called riser pipes. More particularly, it concerns improvements in the manner by which the riser pipes are attached at their upper ends to the floating platform, and at their lower ends to anchor means at the mudline, such as conductor pipe set in holes driven into the sea floor. The riser pipes are maintained in tension at all times. When the platform is directly over the conductor pipes, there is no deflection in the riser pipes, and therefore no lateral stress in the riser pipes. However, as the pressure of wind, tide and current causes the platform to move laterally, there must be a bending of the riser pipes.
2. Description of the Prior Art
The vertically moored platform (VMP) is anchored by vertical pipes called riser pipes, kept under high tension. As the platform and jacket move horizontally, under the influence of wind, wave and current, the riser pipes are deformed. The high tension has a tendency to concentrate the bending deformation in the riser pipes at each end of the risers, where they extend vertically into the ground at the bottom end, and into the platform at the upper end.
These large deformations are detrimental to the risers. To distribute these deformations along the riser pipes, to decrease the maximum stresses, terminators have been designed. The terminators are sections of pipe constructed of varying diameter and wall thickness, the diameter and wall thickness both decrease from a mid-section towards each end, so that the flexibility of the end portions is greater than at the mid portion of the terminator. This variable flexibility introduced into the riser pipe system by the terminator distributes the curvature and helps appreciably to reduce the maximum stresses in the riser pipes.
Horizontal bearings have been introduced and positioned at the mid-section of the terminator, so that the terminator itself can rotate in a vertical plane throughout its axis, and, therefore, distribute part of the bending above and below the horizontal bearing, which supports the riser.
SUMMARY OF THE INVENTION
In the past, terminators were made as short as possible from the point of rigid connection to the midpoint, which is held by a horizontal bearing. However, it has been found that if such portion is lengthened and allowed to bend with certain limits, then the overall lengths and thickness of the terminator can, surprisingly, be reduced.
We have found that by use of our invention a greater flexibility in angular deflection at the support point (which may for convenience be called rotation) can be provided without increased stress in the terminator/riser structure, while permitting the design of a smaller terminator with a consequent saving of construction and installation cost.
It is a primary object of this invention to provide a terminator and terminator extension, for anchoring the VMP or other floating structure to the upper end of each riser pipe, and also to provide a terminator and terminator extension at the lower end of the riser when it connects to anchor means at the sea floor.
It is a further object to provide a novel bearing arrangement for transmitting axial and lateral forces from the riser pipe to the jacket leg.
These and other objects are realized and the limitations of the prior art are overcome in this invention by using (a) a terminator and (b) a terminator extension, which when (a) and (b) are combined may be called a "multiterminator" (1) to anchor the upper end of the riser pipe to legs or other appropriate structures of the vertically moored platform and (2) to anchor the lower end of the riser pipe in the conductor pipe at the mudline.
A terminator is a steel tubular device, made of pipe sections of varying length, diameter and wall thickness so that the outer contour of the terminator varies from a cylindrical mid-section, where it is of maximum diameter and selected length, tapering towards both ends. Normally, one end is farther from the largest diameter portion than the other end and consequently tapers more slowly and gradually than does the shorter end. The precise diameters and wall thicknesses vary throughout the length of the tapered portions and are designed to provide a graduated bending as a function of position on either side of the widest portion of the terminator, where it is mounted in an encircling sleeve supported in a leg or jacket of the VMP at the top and supported at the bottom by a pile secured in the earth.
In the first or long terminator of a multiterminator mounted to a floating structure, the longest tapered end is directed downwardly and becomes an extension of the riser pipe which continues downwardly to the mudline where it is connected to a corresponding first or long terminator and a terminator extension, both making up a second multiterminator.
In order to provide tension in the riser pipe, which is necessary to provide the properly controlled motion of the VMP, an axial or thrust bearing can be provided between the terminator and the encircling sleeve, so that the tension in the riser pipe can be transmitted to the jacket of the VMP.
In accordance with our invention the upper short end of the first or long terminator is preferably connected to a short length of riser pipe and then to a second or "short" terminator structure which is connected to surface equipment on the deck of the VMP. A second or upper horizontal bearing can be, but not necessarily, attached between the sleeve inside a leg of a VMP and the second or short terminator so that the pipe passing through the two horizontal bearings can be deflected at each point. Thus the total deflection by this type of rotation support will permit a reduction in stress along the pipe, from the long terminator up to the surface, without providing a very large deflection in the vicinity of the first or lower horizontal bearing.
By the use of a terminator extension, the combined length, weight and cost of the terminator and extension is much less than in the case where the terminator is used alone.
As mentioned, the terminator and extension can be supported in a sleeve inside the jacket (or leg) of the VMP or a floating structure. We have found that an increased flexibility can be provided if the lateral restraints of the horizontal bearings are flexible, in the sense that the pipe can bend in a vertical plane about the center of the horizontal bearing which then acts as a buffer against which the pipe is being bent and the two ends are pressed in a direction opposite the thrust of the bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of this invention and a better understanding of the principles and details of the invention will be evident from the following description taken in conjunction with the appended drawings, in which:
FIG. 1 illustrates schematically a complete section of the riser pipe, from below the mudline up through the sea and up into the jacket of a vertically moored platform showing the type of curvature that is experienced.
FIG. 2. illustrates a general design for a terminator.
FIG. 3 illustrates the construction of a terminator and terminator extension of our invention, positioned inside a jacket leg with proper horizontal bearings.
FIGS. 4 and 5 show schematically the arrangement of the terminator extensions respectively at the mudline, and inside the jacket leg.
FIG. 6 illustrates an alternate embodiment of that shown in FIG. 3.
FIG. 7 illustrates a combination horizontal and thrust bearing for positioning the terminator in the jacket leg.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1, there is shown a simple diagram of a vertically moored platform (VMP) indicated generally by the numeral 10 having a jacket leg 12 into which is inserted, through the bottom, a riser pipe 26 which is in effect a continuation of a pipe or casing 38 which is anchored below the mudline after passing through conductor casing 36. The bottom anchor of the riser pipe is such that it can support the tension which will be required to hold the vertically moored platform in position on the sea surface. At the point 22 there is a horizontal bearing for transmitting lateral or horizontal forces, and at point 14 there is a vertical bearing for transmission of axial forces.
There are flexure zones 24 and 28 within the length of the riser pipe near the platform and the mud-line, respectively. The portion 26A between the flexure point is substantially straight but non-vertical, while the riser pipe is vertical in the earth and is vertical inside the platform leg. Thus bending is concentrated where the curvature is shown just below the platform leg and just above the well template 32 which rests on the mud surface 34.
The object of the terminator is not only to anchor the riser pipe at the platform but also to design the anchor mechanism so as to properly provide the necessary curvature shown in FIG. 1 without stressing the pipe or terminator and other tubular members, that may be inside the riser, more than a selected maximum.
FIG. 2 illustrates a typical prior art design of a terminator, which is joined at its two ends 42A and 42B, to riser pipes extending upwardly and downwardly. The terminator is designated generally by the numeral 40 and has a cylindrical portion 40D of selected length and diameter which tapers off through appropriate conical pipes 40E going down to the riser pipe, and various sections 40C, 40B, 40A, etc. going upwardly to the riser pipe. As shown on the drawing, the inner diameter and outer diameter vary throughout the length of the terminator, while one is constant the other varies and vice versa, or both vary simultaneously depending upon the most convenient way to design and construct the device. There is no precise dimension for the overall length of the terminator. It can have the two ends of equal length or have a longer portion in one direction, length L1, and a shorter portion of length L2 in the other direction. The reason that this is preferred is that in the end which is joined to pipe inside a containing pipe or sleeve, the amount of deflection that can be permitted is less than the other long end L1, where the pipe is in the water and has no lateral constraint. If the design were symmetrical about the anchor point 43, then the deflection would be symmetrical on each side of the point, and the design of the terminator would be symmetrical also.
The mathematics for determining lateral deflection of a vertically suspended pipe are well known. The system can be described by the following beam column differential equation: ##EQU1## where: E(x)=modulus of elasticity,
I(x)=moment of inertia,
P(x)=axial load,
y(x)=lateral deflection, and
x=location along the length of the beam column.
By applying the known boundary conditions of a system, the differential equation can be solved such as to satisfy all required conditions. Such required conditions can include stress level, lateral deflection limits, or structural section size and/or configuration.
Referring now to FIG. 3, there is shown in schematic outline a construction of a novel multiterminator having a terminator indicated generally by the numeral 58 and a termination extension generally indicated by numeral 64. Terminator 58 has a short leg 59 and a long leg 60. The long leg is directed downwardly and joins a length of riser pipe 26. The mid section, which is preferably not in the center of the terminator, is held in a horizontal bearing 54. This horizontal bearing 54 provides a lateral restraint for the terminator 58. If the horizontal bearing 54 is modified as shown in FIGS. 6 or 7, it can also provide for axial force transmission. As previously indicated, the lengths of the short and long ends 59A and 60A preferably are not equal and may roughly be defined in a ratio of approximately 1:2. The overall length can vary depending on the size and dimensions of the pipes, etc., and the tension required. The terminator 58 is provided with horizontal support at the lower horizontal bearing 54 which will be discussed in connection with FIG. 7. The length of the terminator extension is indicated by the numeral 62 and is a portion of the assembly reaching from the point of horizontal bearing 54 of the terminator 58 to the point 66, above a second horizontal bearing 56. The length of the terminator 58 is indicated by 58A. A suitable horizontal bearing is shown in U.S. Pat. No. 4,130,995 entitled "VMP Riser Horizontal Bearing" issued on Dec. 26, 1978.
Sleeve 50 forms an inner opening through the jacket leg 12 through which the riser pipe enters up into the drilling and producing portions of the platform. The top of the short leg 59 goes to a short length 26' of the riser pipe which is connected to a "short" or second terminator 63 that has a double-ended, substantially symmetrical, tapered section 64, which can be provided with a second horizontal bearing 56 inside sleeve 50. Riser pipe section 26' and short terminator 63 and terminator end 58 form what can be called a terminator extension 62. That portion of FIG. 3 indicated by sections 60A and 62 can be called a "multiterminator". The upper end 66 of the terminator extension is roughly set at the point where there is little or no bending moment in the pipe 26". The riser pipe 26" then extends through an optional vertical bearing 57, which permits sliding contact of very small amounts which occur as the curvature of the pipe 26 varies. However, since the motion of the pipe 26" through the vertical bearing 56 is very small, the construction can be simple friction contact. A suitable vertical bearing 57 can be such as shown in U.S. Pat. No. 4,127,005 entitled "Riser/Jacket Vertical Bearing Assembly for Vertically Moored Platform" issued Nov. 28, 1978.
For the purposes of the following discussions, three bearings 54, 56 and 57 will be referred to, as well as two terminators 58 and 63; however, it should be understood that only two bearings are needed for the purposes of the present invention. That is, bearing 54 and 56 can be used, but bearing 57 is optional as design loads dictate its use. The use of bearing 56 and the second terminator 63 may not be needed, as shown in FIG. 6, if design loads dictate; however, it has been found for most applications the use of the two terminators and at least two bearings is preferable to provide the beneficial results described hereinbelow.
Referring to FIGS. 4 and 5, FIG. 4 shows the lower end of the riser pipe as it is anchored to the conductor pipe 70, which is anchored in the earth 71. The principal terminator 58 with legs 60 and 59, are the same as illustrated in FIG. 3 and the section of riser pipe 26' and also the second terminator 64 and horizontal bearings 56 and 54 are all as shown in FIG. 3, except that at the lower end of the pipe, the terminator is inverted with respect to the upper end of the anchoring at the VMP or other floating structure.
FIG. 5 is similar except that it is now in the same direction of installation as in FIG. 3, with the long leg 60 of the principal terminator pointed downwardly into the water, while the short end is connected through a section of riser pipe 26A and the short terminator 63 and the pipe 26B going up through the vertical bearing 57.
The curved line 76 which passes through the center 86 of the lower horizontal bearing 54 and also through the center 88 of the upper horizontal bearing 56 would illustrate in an exaggerated fashion, the curvature of the structure of FIG. 5 when there is a deflection, for example, of the VMP to the left. The lower portion 75 of the curve is deflected to the right of the upper portion 76 of the curve as the jacket tends to move to the left. The terminator rotates, i.e., angularly deflects inside bearing 54. Again, the upper terminator 64 angularly deflects a small amount in its bearing 56 in a reverse direction with decreasing amplitude over the amplitude in the section between the two terminators. Thus the curvature would be greatest at the lower end 75, less on the top 77 of the lower 58 terminator and lower still 78 above the smaller terminator 64.
The arrow 80 is shown as the direction of the force being applied by the platform to the riser pipe through the horizontal bearing 54. The lower portion of the riser pipe is anchored in the earth and the earth provides a restraining force 82. There is also a restraining force 89 applied above the lower terminator by a horizontal force applied at the upper bearing 56.
Any type of bearing support 54 may be used between the upper terminator 63 and the platform leg, as previously mentioned, so long as it provides for a bending in any vertical plane through the leg of the jacket of the VMP. It is also necessary to provide a tension in the riser pipe below the lower bearing 54. A bearing of the type shown in FIG. 7 provides for transmission of both vertical and horizontal forces.
The direction of portion 75 of the line 79 in FIG. 5 makes an angle 81 with the axis of sleeve 72. The direction of the line 79 above the lower bearing 54 makes an angle 83. The lower terminator 58 mid section angularly deflects about point 86 to be tangent to this curve. Angle 83 is smaller than 81. Again, the upper terminator 63 will rotate about point 88 to be tangent to the line 79 at 88. There will be a smaller deflection 78 of the pipe above the upper terminator. Thus, by providing the multiple terminators (there could be a third and fourth one above the top terminator 63, not shown), each in its own bearing 54, 56, a much greater deflection angle 81 can be provided without increasing the stress in the riser pipe.
The first horizontal bearing 54 of FIG. 3 can be as shown in FIG. 7, which indicates a fixture 90 surrounding the pipe 58B which is the cylindrical center portion of the terminator 58. The fixture 90 has two rings, an upper ring 92, and a lower ring 94. Point 86 represents the center of the spherical portions. The horizontal bearing centerline 54A will pass through that center 86. The bearing elements are essentially an outer steel base ring 96 and an inner steel ring 98 supported by ring 92. Ring 98 is attached to ring 92 and its outer surface is spherical. The inner surface of the outer portion 96 which is attached to the sleeve 50 is also spherical and the center shell portion 100 is a resilient elastomeric compliant material, which is bonded to the spherical suriaces of the portions 98 and 96. Thus the two surfaces 98 and 96 have limited movement to rotate about the center 86 with respect to each other, while the inner material 100 moves in a shearing action, so that a substantially frictionless rotation is possible over a limited angle.
The lower spherical bearing has an inner ring 98A and an outer ring 96A, with a corresponding intermediate portion 100A. This is an alternate means to provide the thrust transmission means required to maintain the tension in the riser pipe, but still permits the rotational feature controlled by the horizontal bearings 54. The bearing rings 98A, 96A, and 100A are supported on ring 94. The center of the spherical surfaces 98A, 96A is at point 86.
While the success of the bearing, such as the one illustrated in FIG. 7, is important to the success of the entire anchoring system, including the terminator and the terminator extension; and while the design shown in FIG. 3 may be preferred, other designs can, of course, be used provided they meet all of the motion and stress requirements, and utilize flexibility of the terminator and terminator extension previously described.
The upper horizontal bearing 56 of FIG. 5, which supports the upper terminator 63, is not required to take thrust. Therefore, bearing 56 may simply be the horizontal bearing portion 92 of the bearing assembly shown in FIG. 7. This would include the ring 92, the two spherical rings 98 and 96 and the compliant shell 100.
Ring 98 has an outer surface which is spherical, centered at point 86. Ring 96 has an inner surface which is spherical, also centered at point 86. Point 86 is on the axis of the terminator and sleeve 50. It also lies on the central horizontal plane 54A through the rings 98, 96. The spherical surfaces of the rings 98 and 96 are spaced apart a selected distance, and this space is filled with a selected elastomeric material, which is preferably bonded to both spherical surfaces.
The two portions of the bearing assembly lateral bearing 92 and thrust bearing 94 are mounted on a rigid internal pipe 58B, which comprises the cylindrical midsection of the principal terminator 58. The tubular members 91, shown by dashed lines, represent one of a plurality of casings which may lie in the annulus between the innermost casing or conductor pipe 93. These are all substantially co-axial pipes, and form another reason for limiting the maximum stress and deflection at all points along the riser pipe.
We have shown in FIGS. 3 and 5 a complete set of bearings for the multiterminator or terminator extension of this invention. In FIG. 7 we have shown the thrust bearing 94 as a part of an assembly with one of the lateral bearings 92. However, it is equally possible to apply the thrust bearing widely spaced from the lateral bearings.
With the thrust bearing widely spaced from the lateral bearings, a lateral bearing is required which has a combination of rotary and sliding motion. Such a bearing is illustrated in FIG. 5 of U.S. Pat. No. 4,130,995 which has a portion 48 which combines an outer cylindrical surface 82 with an inner spherical surface 56.
Another embodiment of the present invention is shown in FIG. 6, wherein a terminator assembly is provided with only two bearings 54 and 57. In this embodiment, the first terminator 58 has its long leg 60 connected to a riser pipe 26 which extends up from the sea floor or downward from the sleeve 50. A bearing 57, either a horizontal or a combination of a horizontal and a vertical bearing, is spaced a certain distance up or down the riser 26". This distance is important because it should be of a length such that under maximum design loads the riser 26" and 26' will deflect or bend no more than to allow the riser to contact the interior wall of the sleeve 50. Depending upon the sleeve's 50 construction and structural support, the sleeve 50 can withstand some amount of force exerted on it by the riser. However, it is preferable that the distance between the bearing 57 and bearing 54 is such that under maximum design loads there will be no contact between the riser and the sleeve 50.
We have described a multiterminator which is an improvement in the anchoring mechanism by which a riser pipe is attached in a vertical manner inside a jacket leg of a vertically moored platform or other floating structure. The same construction can also be utilized at the lower anchorage of the riser pipe with the earth. By the use of the terminator and terminator extension (multiterminator), it is possible to maintain a greater total angular deflection of the pipe without providing any greater maximum value of stress in the pipe at any point.
The required length and weight of the prior art terminator and of the multiterminator of our invention were calculated using known tension beam equations for the following design conditions of an offshore location.
Water depth--1000 feet
Wind--130 knots
Wave--90 feet maximum; 13.5 second period
Current--4.4 feet/second
Riser outside diameter--18.625 inches
Riser wall thickness--0.625 inches
Pre-tension per riser--600,000 pounds
Pre-tension per riser--600,000 pounds
Diameter of sleeve 50 in jacket leg through which riser passes--45 inches
Diameter of piles or conductor pipes 70 in sea floor through which riser extends--40 inches
Maximum allowable outer fiber stress--65,000 pounds/sq. in.
The following table shows the results of our calculations comparing the length and weight of our multiterminator (as indicated in FIG. 3) and the prior art terminator (as indicated in FIG. 2) in which the outer fiber stress from the combined effects of axial tension and bending moment is equal to the maximum allowable value along the entire length of the terminator assembly.
______________________________________Length Length Weight Weight(Prior Art (Multi- (Prior art (Multi-terminator) terminator) terminator) terminator)______________________________________Upper Assembly176 ft. 106 ft. 83,300 lbs 42,700 lbsLower Assembly176 ft. 127 ft. 6 in. 127,000 lbs 90,800 lbs______________________________________
This reduction in overall length and total weight is most important. For example, these terminators will have to be manufactured at specially equipped fabrication centers and shipped and installed as a unit. The reduction in length and weight of multiterminators using our invention makes the offshore installation much more practical and in some cases permits installations which might otherwise be prohibited because of the size of terminator required under the prior art system.
While we have described this invention as related to the vertically moored platform, for which it is admirably suited, it can also be used with other types of floating structure.
While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the exemplified embodiments set forth herein but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.
|
This invention is an improvement over the simple riser pipe terminator, which has been applied at the mudline and at the platform level, to resist very large stresses in the riser pipes when a vertically moored platform (VMP) or other similarly tethered structure is subjected to wind, tide and current. A second or short terminator is used with the terminator to form a multiterminator which results in the length and weight of the terminator assembly for a given site being greatly reduced from that of the prior art terminator. Thus, the cost of construction of the terminator assembly is drastically reduced with the use of our invention. Also disclosed is a novel bearing arrangement between the structure VMP and the terminator assembly.
| 4
|
FIELD OF THE INVENTION
The invention relates to the preparation of a cationically modified (meth)acrylamide polymer by the Mannich reaction. The invention additionally relates to the use of the polymer as a flocculation, retention and dewatering agent.
BACKGROUND
A known process for preparing cationic polymers of a high molecular weight is to modify copolymers of poly(meth)acrylamide or (meth)acrylamide by the Mannich reaction, wherein the modification is carried out using a secondary amine and an aldehyde, typically formaldehyde, or reaction products of these. When the Mannich reaction is used in the preparation of cationic polymers, the modification is often carried out in an aqueous solution of the polymer. For example, the polymers needed in the treatment of waste waters are polymers of a very high molecular weight, and therefore the treatment must be carried out in very dilute aqueous solutions, typically less than five per cent aqueous solutions. The transport of dilute solutions over long distances is uneconomical, and additionally Mannich-treated (meth)acrylamide polymer solutions are known to be unstable, which is observable as an increase of viscosity with time.
Means of avoiding the transportation of dilute solutions include carrying out the Mannich treatment so that the (meth)acrylamide polymer is in the form of an aqueous solution emulsified in a water-insoluble solvent by means of surface active agents. The other treatment chemicals are then added to this emulsion, which may be more concentrated than the polymer solution, typically 10-40%. Thus the transportation of a dilute polymer solution to the point of use of the cationic polymer can be avoided. At the point of use, water is added to the emulsion, whereupon the polymer in the emulsion will dissolve. However, the method has the disadvantage that it is difficult to separate the solvents and surface active agents present in the emulsion from the solution to be used, and thus they will pass to the target of use in the solution, thus causing process problems and environmental problems.
The disadvantages of the solvents and surface active agents present in the emulsion polymer can be avoided only by using aqueous solutions. However, in order to avoid the transportation of dilute solutions to the point of use, it is preferable to transport the components needed in the reaction to the point of use of the cationic polymer and to carry out the Mannich treatment there.
The simplest method is first to dissolve the required (meth)acrylamide polymer in water and then to add the secondary amine and the formaldehyde at a suitable temperature, and to allow the reaction mixture to react for a suitable time. This has the disadvantage that two different chemicals are required for the modification of the polymer. Furthermore, the formaldehyde and the amines used, such as dimethylamine, are substances difficult to handle, causing, for example, odor problems and a risk of ignition. In addition, it is often necessary to carry out the treatment in a separate container, to which the dissolved polymer must be transferred for the treatment. This increases the treatment time and the number of treatment steps.
In CA patent publication 1 031 096 (G. Sackman et al.), an attempt is made to solve the problems of handling difficult chemicals by using amines which boil at higher temperatures than do simple dialkylamines. However, such amines are less reactive and less economical to use than simpler dialkylamines.
FI patent publication 62846 (Nalco Chemical Co.) proposes as a solution to the problem the Mannich reaction as a continuous process treatment by means of which it is possible to avoid unnecessary transfers between the polymer dissolution apparatus and the treatment vessel. However, the problem of handling two difficult chemicals is not avoided.
The handling of difficult chemicals can be avoided by using the mixture disclosed in U.S. Pat. No. 3,367,918 (The Dow Chemical Co.), which contains, mixed, all the components required in the Mannich treatment, such as a solid salt of a secondary amine, paraformaldehyde as a formaldehyde-producing substance, a solid polyacrylamide, and sodium carbonate as a component which raises the pH. When the mixture is dissolved in water, the Mannich reaction occurs. However, amine salts and solid high-boiling secondary amines are highly hygroscopic. In mixtures with polyacrylamide, their hygroscopicity causes adhesion of the particles in the mixture, a factor which makes the mixed powders difficult to handle.
The separate handling of secondary amine and formaldehyde is avoided if the Mannich treatment is carried out using their reaction product, dialkylaminomethanol, the handling of which is not as difficult as that of secondary amines and formaldehyde. Furthermore, the use of the reaction product reduces the number of the chemicals required for the Mannich treatment from two to one. The preparation of such a reaction product and its use together with acrylamide polymers is described in, for example, U.S. Pat. No. 2,328,901 (Grimm et al.), U.S. Pat. No. 4,010,131 (Philips et al.), U.S. Pat. No. 4,166,828 (McDonald) and U.S. Pat. No. 4,288,390 (McDonald). However, in EP patent 210 784 (Farrar et al.) it is noted that such a reaction product is unstable, for which reason it cannot be stored for long periods of time. During storage the reactivity of the reaction product is at the same time lowered.
SUMMARY OF THE INVENTION
As a result of the present invention, a process has now been achieved by which the stability of the reaction product of a secondary amine and an aldehyde can be improved significantly. The process also provides the further advantage that the cation exchange capacity of a cationically modified (meth)acrylamide polymer can easily be adjusted; this need for modifying the cation exchange capacity is very necessary in particular at waste water treatment plants.
The invention is based on the fact that it is possible to prepare in advance an aldehyde-secondary amine adduct the stability and reactivity of which remain for quite a long period. Thus the handling of two difficult chemicals is avoided, and at the same time the number of work steps is reduced and it is possible to prepare a cationic (meth)acrylamide polymer suited specifically for a given treatment plant.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, an aldehyde-secondary amine adduct prepared in advance is obtained by mixing an aqueous solution of a secondary amine with an aqueous solution of an aldehyde. The aldehyde may be formaldehyde, paraformaldehyde or 1,3,5-trioxane, preferably formaldehyde. The secondary amine may be any dialkylamine, the alkyl carbon chain of which may have 1-5 carbon atoms, the most preferable being dimethylamine. The mixing ratio of the aldehyde to the secondary amine may vary within the range 2:1-1:2. The reaction temperature may vary from room temperature to very high temperatures, depending on how rapid an adduct formation is desired. The formed aldehyde-amine adduct is stabilized to increase shelf life and resistance to reactions by adjusting the pH to 7 or below or by adding methanol to the mixture, or most preferably my adjusting the pH to 7 or below and by adding methanol. The adjustment of the pH may be carried out using either an organic or an inorganic acid, preferably hydrochloric acid, sulfric acid or oxalic acid. The adduct thus stabilized can be transported ready-made to the point of use, where the actual cationic modification of the (meth)acrylamide polymer is carried out to the desired degree of cation exchange capacity.
It is recommended that at the point of use the actual modification of the (meth)acrylamide polymer is carried out in a polymer dissolution apparatus. The adduct solution is added to the dissolution apparatus after the dissolution of the polymer or already during the dissolving. The reaction will progress to some degree at any pH, but in order to accelerate the reaction the pH of the polymer-adduct solution is adjusted to a sufficiently high value, typically above 9, with the necessary amount of an alkali, typically an alkali metal hydroxide or an alkali metal carbonate. The alkali is preferably sodium hydroxide, sodium carbonate, potassium hydroxide or potassium carbonate. The alkali may be added to the solution at the same time as the polymer or separately. The treatment may be carried out at various temperatures, typically at 20-80° C. At a higher temperature the reaction time is shortened, being 10-15 hours at 20° C., 2-5 hours at 40° C., and 0.5-1 hour at 60° C. Preferably polymer is dissolved in hot water in the dissolution apparatus in order that a temperature higher than room temperature should at the same time be obtained for the reaction.
The polymer used in the treatment may be polyacrylamide or polymethacrylamide, or a copolymer of acrylamide or methacrylamide with one or more monomers. Preferably the polymer is polyacrylamide or a copolymer of acrylamide with a cationic monomer. The polymer may be immediately soluble in water, or may become water-soluble only along with the treatment. The molecular weight of the polymer should in general be very high, typically above 100,000. For this reason the concentration of the polymer solution treated is low, typically below 5%, preferably below 1%. The degree of treatment, i.e. the molar ratio of the reacting amine groups and polymer amide groups used, may vary within the range 0.01-1.
The cationic polymer obtained from the treatment may be used, as can other cationic polymers, for example as a flocculant in the settling of colloidal fines, as a retention agent in paper making, for the dewatering of slurry in the treatment of waste waters, and as a filtration aid.
The invention is described with the help of the following examples, the purpose of which is not to limit the scope of the invention.
EXAMPLE 1
100 g of a 37 wt. % formaldehyde and 138.9 g of a 40 wt. % dimethylamine are mixed together. 7 g of methanol is added. This is called reaction product A.
100 g of a 37 wt. % formaldehyde and 138.9 g of a 40 wt. % dimethylamine are mixed together. 118.3 g of a 32 wt. % hydrochloric acid is added (pH of the mixture 7). This is called reaction product B.
100 of a 37 wt. % formaldehyde and 138.9 g of a 40 wt. % dimethylamine are mixed together. 31.6 g of methanol and 118.6 g of a 32 wt. % hydrochloric acid is added (pH of the mixture 7). This is called reaction product C.
Mannich treatments are performed using reaction products A, B and C by adding the reaction products in an amount indicated in Table 1 to 150 g of a 1 wt. % polyacrylamide solution (viscosity of the polymer in a 2 wt. % solution 700 mPas 25° C.). The pH of the solution is adjusted to 10 by using a 12 wt. % sodium hydroxide solution. The mixture is allowed to react for 5 hours at 40° C.
Mannich treatments are performed at different times. The cation exchange capacities of the solutions are measured. The results shown in Table 2 are obtained.
TABLE 1
Reaction
Reaction
Reaction
product A
product B
product C
Dose in the treatment, g
3.2
4.6
5.8
Degree of treatment
0.75
0.75
0.87
(= molar ratio of the
amine used to the amide
groups in the polymer)
TABLE 2
(Values indicate cation exchange capacity, meq/g)
Time from the
making of the
Reaction
Reaction
Reaction
Reaction
Reaction
Reaction
reaction
product
product
product
product
product
product
product, d
A
B
C
A
B
C
pH 4
pH 4
pH 4
pH 7
pH 7
pH 7
0
0.07
0.07
0.06
0.06
2
0.07
0.07
0.06
0.06
5
0.07
0.06
0.07
0.06
0.05
0.06
7
0.06
0.06
0.07
0.06
0.06
0.06
14
0.06
0.06
0.07
0.05
0.05
0.06
21
0.05
0.06
0.06
0.05
0.05
0.06
The example shows that methanol and a lowering of the pH each even alone stabilizes the reaction product, but the stabilization is most effective when they are used together.
The following example describes how the reaction mixture ages when stabilization is not used.
EXAMPLE 2
To 200 g of a 2 wt. % polyacrylamide solution (same polymer as in Example 1), 3.4 g of a 37 wt. % formaldehyde and 4.8 g of a 40 wt. % dimethylamine are added (treatment degree 0.75). The mixture is allowed to react for 5 hours at 40° C. The cation exchange capacity of the solution is measured. The result is 0.18 meq/g at a pH of 4and 0.10 meq/g at a pH of 7.
3.4 g of a 37 wt. % formaldehyde and 4.8 g of a 40 wt. % dimethylamine are mixed together. After 24 hours this mixture is added to 200 g of a 2 wt. % polyacrylamide solution (same polymer as in Example 1). The mixture is allowed to react for 5 hours at 40° C. The cation exchange capacity of the solution is measured. The result obtained is 0.18 meq/g at a pH of 4 and 0.07 meq/g at a pH of 7.
3.4 g of a 37 wt. % formaldehyde and 4.8 g of a 40 wt. % dimethylamine are mixed together. After 3 weeks this mixture is added to 200 g of a 2 wt. % polyacrylamide solution (same polymer as in Example 1). The mixture is allowed to react for 5 hours at 40° C. The cation exchange capacity of the solution is measured. The result obtained is 0.14 meq/g at a pH of 4 and 0.05 meq/g at a pH of 7.
The effects of the pH and methanol content of the mixture are illustrated in the following example.
EXAMPLE 3
Reaction products according to Table 3 are prepared:
TABLE 3
DMA
PFA
HCl
HCOOH
MeOH
Storage
Dosage
Degree of
g
g
g
g
g
pH
g
treatment
Reaction product D
84.5
22.5
75.2
6
1.8
0.75
Reaction product E
84.5
22.5
72.2
7
1.8
0.75
Reaction product F
84.5
22.5
77.2
5
1.8
0.75
Reaction product G
84.5
22.5
72.2
12.6
7
1.9
0.75
Reaction product H
84.5
22.5
72.2
1.6
7
1.8
0.75
Reaction product I
84.5
22.5
29.3
9.5
7
1.5
0.75
DMA = 40 wt. % dimethylamine
PFA = paraformaldehyde, J. T. Baker (Laboratory Grade)
HCl = 32 wt. % hydrochloric acid
HCOOH = formic acid
MeOH = methanol
Mannich treatments are performed using reaction products D-I so that the reaction products are added in the amounts indicated in Table 3 to 142 g of a 0.5 wt. % polyacrylamide solution (molecular weight approx. 6,500,000). The pH of the solution is adjusted to 10 by using a 10 wt. % sodium carbonate solution. The mixture is allowed to react for 5 hours at 40° C.
Mannich treatments are performed at different times. The cation exchange capacities of the solutions are measured.
The results shown in Table 4 are obtained:
TABLE 4
(Values indicate cation exchange capacity, meq/g)
Reaction
product:
D
E
F
G
H
I
Measurement pH
pH 4
pH 4
pH 4
pH 4
pH 4
pH 4
Storage time of
reaction product
d
1
0.023
0.023
0.023
0.024
0.023
0.022
7
0.021
0.020
0.020
0.020
0.020
0.010
14
0.020
0.021
0.020
0.020
0.019
0.007
56
0.022
0.017
0.018
0.016
0.017
0.001
Measurement pH
pH 7
pH 7
pH 7
pH 7
pH 7
pH 7
Storage time of
reaction product
d
1
0.021
0.021
0.021
0.021
0.021
0.021
7
0.017
0.018
0.018
0.018
0.018
0.009
14
0.017
0.017
0.018
0.018
0.018
0.006
56
0.015
0.014
0.015
0.014
0.014
0.002
The example shows that hydrochloric acid is a better acid for pH adjustment than formic acid. The lowering of the pH from 7 to 5 does not improve stability. Methanol improves stability somewhat when it is used together with the lowering of the pH.
EXAMPLE 4
11.9 g of paraformaldehyde (containing 84 wt. % formaldehyde) and 35.7 g of a 40 wt. % dimethylamine are mixed together. This is called reaction product J. The lowering of its activity is observed as a function of time.
At each point of time, 3.2 g of reaction product J (degree of treatment 1.00) is added to 200 g of a 1 wt. % polyacrylamide solution (same polymer as in Example 1). The mixture is allowed to react for 5 hours at 40° C.
The cation exchange capacity of the solution is measured. The results shown in Table 5 are obtained:
TABLE 5
Storage time of
reaction product
Cation exchange capacity
Cation exchange capacity
d
at pH 4, meq/g
at pH 7, meq/g
0
0.13
0.07
2
0.09
0.04
4
0.07
0.05
7
0.06
0.05
14
0.04
0.03
The examples show that if the dimethylamine solution and the formaldehyde solution are mixed together before the reaction with polyacrylamide, the reaction capacity of the reaction product is lowered in three weeks so that the cation capacity of a 2 wt. % polyacrylamide solution with a treatment degree of 0.75 drops from 0.18 meq/g to 0.15 meq/g at a pH of 4 and from 0.10 meq/g to 0.05 meq/g at a pH of 7.
When paraformaldehyde is used instead of a formaldehyde solution, the reaction capacity of the reaction product is lowered in two weeks so that the cation exchange capacity of a 1 wt. % polyacrylamide solution with a treatment degree of 1.00 drops from 0.13 meq/g to 0.04 meq/g at a pH of 4 and from 0.07 meq/g to 0.03 meq/g at a pH of 7. The more rapid lowering of the reaction capacity is due to the fact that, when paraformaldehyde is used, methanol used for the stabilization of a formaldehyde solution does not end up in the reaction product.
The significance of the storage pH of the adduct is examined in greater detail in the following example.
EXAMPLE 5
Reaction products according to Table 6 are prepared. They are called reaction products K-O.
TABLE 6
Reaction product
K
L
M
N
O
DMA, g
100.0
100.0
100.0
100.0
100.0
CH 2 O, g
72.0
72.0
72.0
72.0
72.0
HCl, g
12.6
50.6
91.8
100.8
101.1
Storage pH
pH 9
pH 8
pH 7
pH 6
pH 5
Dose, g
1.6
1.9
2.2
2.3
2.3
Treatment degree
0.75
0.75
0.75
0.75
0.75
DMA = 40 wt. % dimethylamine
CH 2 O = 37 wt. % formaldehyde
HCl = 32 wt. % hydrochloric acid
Mannich treatments are performed using reaction products K-O after 4 weeks of storage of the reaction product so that the reaction products are added in the amounts shown in Table 6 to 142 g of a 0.5 wt. % polyacrylamide solution (molecular weight approx. 6,500,000). The pH of the solution is adjusted to 10 by using a 10 wt. % sodium carbonate solution. The mixture is allowed to react for 5 hours at 40° C.
The cation exchange capacities of the solutions are measured. The results shown in Table 7 are obtained.
TABLE 7
Reaction product
K
L
M
N
O
Storage pH
pH 9
pH 8
pH 7
pH 6
pH 5
Cation exchange
0.016
0.014
0.022
0.024
0.024
capacity at pH 4, meq/g
Cation exchange
0.013
0.012
0.020
0.022
0.022
capacity at pH 7, meq/g
The results show that the stability of the adduct is at its best when the storage pH of the adduct is 7 or lower.
In the following example, the ratio of formaldehyde to dimethylamine is examined from the viewpoint of stability.
EXAMPLE 6
Reaction products according to Table 8 are prepared. They are called reaction products P-T.
TABLE 8
Reaction product
P
Q
R
S
T
CH 2 O/DMA mol/mol
1.2
1.1
1.0
0.9
0.8
DMA, g
100.0
100.0
100.0
100.0
100.0
CH 2 O, g
86.4
79.2
72.0
64.8
57.6
HCl, g
94.0
93.1
91.8
93.2
94.2
Storage pH
pH 7
pH 7
pH 7
pH 7
pH 7
Dose, g
2.0
2.1
2.2
2.4
2.7
Treatment degree
0.75
0.75
0.75
0.75
0.75
DMA = 40 wt. % dimethylamine
CH 2 O = 37 wt. % formaldehyde
HCl = 32 wt. % hydrochloric acid
Mannich treatments are performed using reaction products P-T after 4 weeks of storage of the reaction products so that the reaction products are added in the amounts shown in Table 8 to 142 g of a 0.5 wt. % polyacrylamide solution (molecular weight approx. 6,500,000). The pH of the solution is adjusted to 10 by using a 10 wt. % sodium carbonate solution. The mixture is allowed to react for 5 hours at 40° C.
The cation exchange capacities of the solutions are measured. The results shown in Table 9 are obtained.
TABLE 9
Reaction product
P
Q
R
S
T
CH 2 O/DMA mol/mol
1.2
1.1
1.0
0.9
0.8
Cation exchange capacity
0.021
0.021
0.022
0.024
0.023
at pH 4, meq/g
Cation exchange capacity
0.019
0.019
0.020
0.021
0.020
at pH 7, meq/g
The results show that the stability of the adduct is at its best when a small excess of amine has been used in the preparation of the adduct.
In the following example, the significance of different acids is examined.
EXAMPLE 7
Reaction products according to Table 10 are prepared. They are called reaction products U-W.
TABLE 10
Reaction product
U
V
W
DMA, g
100.0
100.0
100.0
CH 2 O, g
72.0
72.0
72.0
HCl, g
91.8
H 2 SO 4 , g
42.4
C 2 H 2 O 4 · 2H 2 O
53.7
Storage pH
pH 7
pH 7
pH 7
Dose, g
1.8
1.9
2.2
Treatment degree
0.75
0.75
0.75
DMA = 40 wt. % dimethylamine
CH 2 O = 37 wt. % formaldehyde
HCl = 32 wt. % hydrochloric acid
H 2 SO 4 = strong sulfuric acid
C 2 H 2 O 4 · 2H 2 O = oxalic acid dihydrate
Mannich treatments are performed using reaction products U-W after 4 weeks of storage of the reaction products so that the reaction products are added in the amounts shown in Table 10 to 142 g of a 0.5 wt. % polyacrylamide solution (molecular weight approx. 6,500,000). The pH of the solution is adjusted to 10 by using a 10 wt. % sodium carbonate solution. The mixture is allowed to react for 5 hours at 40° C.
The cation exchange capacities of the solutions are measured. The results shown in Table 11 are obtained.
TABLE 11
Reaction product
U
V
W
Cation exchange
0.024
0.025
0.022
capacity at pH 4, meq/g
Cation exchange
0.019
0.019
0.020
capacity at pH 7, meq/g
The results show that even other acids in addition to hydrochloric acid function in the stabilization of the adduct.
In the following example the significance of the pH of the reaction solution is illustrated.
EXAMPLE 8
81.2 g of a 37 wt. % formaldehyde solution and 118.3 g of a 40 wt. % dimethylamine are mixed together. The mixture is allowed to react for 2 hours at 45° C., whereafter the mixture is cooled and its pH is lowered to 6.5 by using a 32 wt. % hydrochloric acid (122.5 g).
Mannich treatments are performed using the reaction product, at different pH values, by adding 2.3 g of the reaction product to 142 g of a 0.5 wt. % polyacrylamide solution (molecular weight approx. 6,500,000). The pH values of the solutions are adjusted to the values shown in Table 12 by using a 10 wt. % sodium carbonate solution. The mixture is allowed to react for 5 hours at 40° C.
TABLE 12
pH of reaction
10 wt. % sodium
Charge at pH
Charge at pH
solution
carbonate solution, g
4, meq/g
7, meq/g
7.4
0
0.007
−0.0004
8
0.43
0.007
0.004
9
2.95
0.017
0.014
9.5
5.85
0.024
0.014
10
12.29
0.025
0.022
The charges of the solution are measured. The results shown in Table 12 are obtained. It is seen that the reaction progresses more rapidly at high pH values.
EXAMPLE 9
Mannich treatments are performed by adding the amounts shown in Table 13 of dimethylamine and formaldehyde to 200 g of a 1 wt. % polyacrylamide solution (polymer viscosity in 2 wt. % solution 700 mPas 25° C. Brookfield, spindle No. 31, 12 rpm). The pH of the solution is adjusted to the values shown in the table, first by using a 32 wt. % hydrochloric acid and finally by using a 3.2 wt. % hydrochloric acid. The mixture is allowed to react for 5 hours at 40° C. The cation exchange capacities of the solutions are measured at pH values of 4 and 7.
TABLE 13
Reaction conditions:
40 wt. % dimethylamine, g
2.50
2.50
2.38
37 wt. % formaldehyde, g
1.71
1.88
1.71
Treatment degree with respect to
0.79
0.79
0.75
dimethylamine
Treatment degree with respect to
0.75
0.82
0.75
formaldehyde
Initial pH of the reaction solution
4.4
3.0
3.0
Consumption of 32 wt. % hydrochloric
2.0
2.1
2.2
acid, g
Consumption of 3.2 wt. % hydrochloric
3.5
2.3
1.4
acid, g
Product obtained:
Cation exchange capacity at pH 4,
0.024
0.010
0.009
meq/g
Cation exchange capacity at pH 7,
0.019
0.009
0.008
meq/g
A comparison of the results with those presented in Example 1, obtained at a pH of 10, shows that the cation exchange capacities of the solutions remain clearly lower. This shows that the Mannich reaction does not progress nearly as well in acid conditions as in alkaline conditions.
|
The invention relates to a process for preparing a cationically modified (meth)acrylamide polymer by the Mannich reaction. There is prepared in advance a stable aldehyde-secondary amine adduct, which is obtained as a reaction product of an aqueous solution of the secondary amine and an aqueous solution of the aldehyde, and which, after the formation of the adduct, is stabilized to endure storage, by lowering the pH of the mixture of 7 or below and/or by adding methanol, and the adduct thus prepared is added to an aqueous solution of the (meth)acrylamide polymer and the pH is adjusted to an alkaline level, whereupon modification occurs. The invention also relates to the use of the modified (meth)acrylamide polymer as a flocculation, retention or dewatering agent.
| 2
|
BACKGROUND OF THE INVENTION
The field of this invention relates to the liquid-phase oxidation of pseudocumene (PSC). In one aspect, this invention relates to conducting the initial part of the reaction in a semi-continuous or batch mode followed by a batch tail-out wherein most of the bromine promoter and cerium in the plus three valence is added in the batch tail-out stage, thus reducing the contact time of the polycarboxylic acid moieties with cobalt-manganese-bromine or zirconium-cobalt-manganese-bromine catalysts and improving the yield of trimellitic acid (TMLA) from PSC.
The bromine-polyvalent metal catalysts in acetic acid solvent have been in commercial use in many countries for the manufacture of terephthalic acid from p-xylene for many years. However, in the absence of acetic acid solvent, the best yield of a single phthalic acid (e.g., terephthalic acid) on a once-through basis of the xylene amounted to about 20 weight percent (12.8 mole %), according to U.S. Pat. No. 2,833,816. According to U.S. Pat. No. 3,920,735, the Mn-Br and Co-Mn-Br catalyst systems are improved by the addition of zirconium. However, not mentioned, but illustrated in Tables I, II and IV in U.S. Pat. No. 3,920,735, is the fact that, when part of the zirconium is added, combustion of the feedstock to carbon dioxide increases. The use of cerium has been disclosed in the U.S. Pat. No. 3,491,144 however, in that reference cerium is not added to the batch tail-out part of the reaction in the plus three valence state wherein the amount of bromine added is reduced.
DESCRIPTION
My novel invention is a process for the oxidation of pseudocumene PSC with molecular oxygen to TMLA under liquid-phase conditions in the presence of a cobalt-manganese-cerium-bromine catalyst or a cerium zirconium-cobalt-manganese-bromine catalyst wherein the atomic ratio of cerium to cobalt is in a range from 1 to about 2 to about 1 to about 25, which process comprises conducting a semi-continuous oxidation of the PSC so that the concentration of the polycarboxylic acids is very low, permitting only partial oxidation of the PSC, thus avoiding the poisoning of the catalyst and completing the reaction in a non-continuous process at a temperature of about 120° C. to about 175° C. to about 150° C. to about 275° C. wherein most of the bromine and all of the cerium catalyst is added in the tail-out part of the reaction.
In a preferred embodiment my process comprises the oxidation of PSC with molecular oxygen to TMLA under liquid-phase conditions in the presence of a zirconium-cobalt-manganese-cerium-bromine catalyst or a cobalt-manganese-cerium-bromine catalyst, wherein the atomic ratio of cerium to cobalt is about 1:2 to about 1:25 at a temperature in the range of about 100° C. to about 200° C., conducted using a semi-continuous or batch oxidation of the pseudocumene so that the amount of bromine in the first stage added is about 0 to about 35 percent of the total bromine added and the remainder is added in the second stage which is calculated to provide the total bromine-to-metals atomic ratio of about 0.3 to about 1.5, preferably in the range of about 0.4 to about 0.7. The concentration of pseudocumene is kept low so that only one methyl group on the average on the benzene ring is converted to a carboxylic acid group, thus avoiding the poisoning of the catalyst and completing the reaction in a non-continuous process at a temperature of about 120° C. to about 175° C. to about 150° C. to about 250° C.
In another preferred embodiment, my process for the oxidation of PSC with molecular oxygen to TMLA under liquid-phase conditions in the presence of a cerium-zirconium-cobalt-manganese-bromine catalyst wherein the atomic ratio of total zirconium to cobalt is about 1:15 to about 1:45, and the ratio of cerium to cobalt is about 1:2 to about 1:25, at a temperature in the range of about 100° C. to about 275° C. comprises conducting a semi-continuous oxidation of PSC so that only about one to about two of the methyl groups on a benzene ring are converted to carboxylic acid groups, thus avoiding the poisoning of the catalyst and completing the reaction in a non-continuous process at a temperature of about 120° C. to about 175° C. to about 150° C. to about 250° C. Cerium is added only in the non-continuous process stage. For each gram mole of PSC, the concentration of catalyst metals, i.e., cerium, zirconium and cobalt plus manganese, used is in the range of about 3 to about 10 milligram atoms total, and the concentration of bromine used is in a range of about 1.4 to about 10 milligram atoms total per gram mole of PSC.
Zirconium can be added to the reaction in any form soluble in the PSC being oxidized or in acetic acid when it is being used as reaction solvent. For example, zirconium octanoate or naphthanate can be used with manganese and cobalt octanoates or naphthanics for oxidation of PSC in the absence of reaction solvent and each of Zr, Mn, and Co can be conveniently used as its acetate when PSC is oxidized in the presence of acetic acid solvent. Zirconium is available on a commercial basis as a solution of ZrO 2 in acetic acid and, as such, is ideally suited for liquid-phase oxidations using acetic acid as reaction solvent. The cerium is added in the tail-out reaction having a valence of plus three. Suitable cerium compounds must be soluble in the tail-out solution and they include cerium carbonate and cerium acetate.
The source of molecular oxygen for the enhanced oxidation of this invention can vary in O 2 content from that of air to oxygen gas. Air is the preferred source of molecular oxygen for oxidations conducted at temperatures of 120° C. and above up to 275° C. For oxidation conducted with molecular oxygen, the preferred temperatures are in the range of 100° C. to 200° C. The minimum pressure for such oxidations is that pressure which will maintain a substantial liquid phase of 70-80 percent of the reaction medium, either neat PSC, or PSC and 70-80 percent of the acetic acid. The acetic acid solvent, when used, can amount to 1-10 parts on a weight basis per part of the PSC. The PSC and/or acetic acid not in the liquid phase because of vaporization by heat of reaction is advantageously condensed and the condensate returned to the oxidation as a means for removing heat and thereby temperature controlling the exothermic oxidation reaction. Such vaporization of PSC reactant and/or acetic acid solvent is also accompanied by vaporization of lower boiling by-product water. When it is desired to take advantage of the benefits of withdrawing acetic acid and water of reaction from the liquid-phase oxidation, as will be hereinafter demonstrated, condensate is not returned to the oxidation.
My reaction, as applied to PSC, is very difficult and has only been practiced as a batch process in the prior art for the oxidation of PSC because the reaction product, TMLA, is poison for the catalyst. Batch reactions are successful because high concentrations of the product acid occur only near the end of the oxidation, while in continuous oxidations, the product concentration is at a constant high level. Batch oxidations, however, have disadvantages because the concentration of the hydrocarbon near the beginning of the oxidation is high and its rate of oxidation difficult to control. This leads to a low concentration of dissolved oxygen and increased amounts of hydrocarbon radical reactions producing dimeric, high-boiling side products which reduce the yield. Thermally induced destruction of methyl groups of PSC is also known to occur, leading to xylene which eventually become oxidized to dicarboxylic acid groups, thus leading to yield loss. In my novel process, I bypass the difficulties of both batch and continuous oxidations. In this two-step process, I first conduct a semi-continuous oxidation in a manner so that (1) only about one to about two methyl groups on a benzene ring become oxidized to avoid catalyst poisoning, (2) the hydrocarbon concentration is kept low to eliminate much of the radical dimerization reactions, and (3) the temperature is maintained sufficiently low to minimize the destruction of methyl groups. Then, in the second step, I batch oxidize in the presence of cerium and bromine the resultant material from the semi-continuous oxidation so that high concentrations of poisonous product acids occur only near the end of the oxidation.
I have established that my novel process results in predominantly dimethylbenzoic acids under the conditions used in my semi-continuous step. The semi-continuous part of the oxidation is carried out suitably during the first 30 minutes of the oxidation.
The semi-continuous part of the oxidation is conducted so that the concentration of polycarboxylic acids is low, usually about 1-5 mole percent, thus preventing premature catalyst deactivation. Thus, the theoretical oxygen uptake is somewhere between 1 and 2.5 moles O 2 /mole hydrocarbon, with 1.5-2 moles being preferred. Because of side reactions, the actual oxygen uptake may be slightly higher. Also, the semi-continuous oxidation is run at a low enough temperature, usually about 120° C. to about 200° C., to allow maintenance of an oxygen concentration above 0.5 percent in the vent gas, with 2-8 percent being preferred. After all the hydrocarbon has been pumped in, the oxidation is finished in a non-continuous process. In the non-continuous batchwise step, the temperature of reaction is increased from a temperature in the range of about 120° C. to about 175° C., to a final temperature in the range of about 150° C. to about 250° C. to compensate for the decreasing reaction rate. In this step, cerium, bromine, manganese, zirconium, and optionally cobalt, alone or in any combination, are added.
In the batchwise oxidation of PSC, the exothermic heat of reaction vaporizes some of the liquid solvent which is carried out by the reactor by the process air. The solvent is condensed and returned to the reactor as reflux. This liquid reflux is reheated toward the end of the reaction cycle to ensure temperatures high enough to bring the oxidation to completion. After reaction, the reactor contents are depressurized and TMLA is crystallized out to form a 50-60 percent solids slurry (close to the maximum solids concentration that is pumpable). The solids are filtered out and further processed into final product. The filtrate is disposed of and, therefore, represents a significant yield loss.
Under the conditions embodied by my novel process, the solvent condensed out of the reactor vent gas is withdrawn and not returned as reflux to the reactor. Solvent withdrawal maintains reactor temperatures high enough to compete the reaction thereby saving energy due to the elimination of reflux reheating. The withdrawn solvent is rich in water as opposed to a saturated lower aliphatic acid, i.e., acetic acid. Therefore, since TMLA is ten times more soluble in water than in acetic acid, with water-rich solvent withdrawal the crystallizer effluent is suitably thickened to 70 percent solids instead of 60 percent, thereby recovering more TMLA and reducing filtrate losses. In practice, a slurry containing more than 70 percent solids is difficult to pump. To ease operating problems, enough filtrate, which is saturated with TMLA is pumped to the crystallization section to provide pumpability while maintaining an overall increase in yield. Usually, about 20 to about 80 percent of the total filtrate is pumped to the crystallization section.
An alternate suitable embodiment of the present invention comprises the withdrawal of the condensed solvent, acetic acid and water of reaction during the last 5 to about 20 percent of the oxidation reaction period using acetic acid reaction medium in the weight ratio to PSC of about 1.0:1.0 to about 2.5:1.0. The metal oxidation catalyst components are cerium, cobalt, zirconium and manganese or cerium, cobalt and manganese. Total metal concentration for each gram mole of PSC is in the range of about 3 to about 10, preferably about 5 to about 8 milligram atoms in combination with a source of bromine, providing a bromine concentration of about 1.4 to about 10, preferably about 3 to about 7 milligram atoms per gram mole of PSC. The manganese component of the catalyst is at least 8 weight percent, preferably in the range of about 25 to about 40 weight percent based on the total weight of catalyst metals. The cerium content of the total metals used is in the range of about 9 to about 30, preferably about 15 to about 22 weight percent. The zirconium content of the total metals used is in the range of about 2 to about 5, preferably about 3 to about 4 by weight percent of the total metals. The cobalt component of the catalyst is in the range of about 30 to about 70 weight percent of the total metals.
Another alternate and suitable mode of conduct for the catalytic liquid-phase air oxidation of PSC to TMLA is staged addition of the cerium and bromine component. This improved mode of conduct provides a shorter overall reaction cycle, reduces metals corrosion and contamination of desired crude product while improving the high yields of the desired acid and low production of methylphthalic acids' and formylphthalic acids' impurities which are features of the prior art. This improved staging of the cerium and bromine component permits the use of lower metals and acetic acid-to-PCS ratio, and provides crude TMLA products of lower metals and bromine-containing impurities which can be more conveniently removed from crude TMLA as the case may be. Other advantages from this improved mode of conduct for cerium and bromine staging will be apparent from the disclosure which follows.
It is particularly desirable to oxidize PSC as completely as possible to TMLA not only to obtain high yields of the acid product in the oxidation effluent, but also to provide potential of recovery of crude TMLA product with low partial oxidation impurities without extensive oxidation of acetic acid. Low impurity formation is a goal also desirable because TMLA is rather soluble in acetic acid and the methylphthalic acids' and formylphthalic acids' impurities appear to enhance the solubilities of TMLA and leading to contamination of the product precipitated from the oxidation effluent, especially a concentrate thereof. Thus, the partial oxidation products in the oxidation effluent have a limiting effect on TMLA precipitations by crystallization from said effluent, making necessary additional processing steps to effect recovery of the remaining TMLA solutes in the mother liquor after separation from first crop product. Also, the presence of the impurities requires special processing of the total crude TMLA to obtain it in commercially acceptable quality as its intramolecular anhydride.
The present inventive staged addition of cerium and bromine for the catalytic liquid-phase air oxidation of PSC to TMLA is conducted using acetic acid reaction medium in the weight ratio of PSC of about 1.0:1.0 to about 2.5:1.0. The metal oxidation catalyst components are cerium, cobalt, zirconium and manganese or cerium, cobalt and manganese. Total metal concentration based on a gram mole of PSC is in the range of about 3 to about 10, preferably about 5 to about 8, milligram atoms in combination with a source of bromine, providing a bromine concentration of about 1.4 to about 10, preferably about 3 to about 7 milligram atoms per gram mole of PSC. The manganese component of the catalyst is at least 8 weight percent, preferably in the range of about 25 to about 40 weight percent based on the total weight of catalyst metals. The zirconium content of the total metals used is in the range of about 2 to about 5, preferably about 3 to about 4, percent by weight of total metals. The cobalt component of the catalyst is in the range of about 30 to about 70 weight percent of the total metals. The cerium content of the total metals used is in the range of about 9 to about 30, preferably about 15 to about 22, percent by weight of total metals.
When the oxidation of PSC is conducted batchwise, all of the PSC and most (90-99 percent) of the acetic acid and initial amount of catalyst components except cerium and bromine are charged at or near oxidation initiation temperature, preferably at about 120° C. to about 165° C., and at a pressure to maintain liquid-phase conditions. Then, pressurized air is injected into the reaction mixture, and the reaction temperature is permitted to increase by heat evolved by the oxidation reaction to about 175° C. to about 225° C.
The total bromine added can be from a single source of bromine, for example, ionic bromine sources (HBr, NaBr, NH 4 Br and the like) or from a combined form of bromine, for example, organic bromides such as benzyl bromide, tetrabromoethane and others.
My novel process relates to the liquid-phase oxidation of PSC to TMLA using cerium, cobalt, manganese and/or other variable-valence metals plus bromine, and when desired, zirconium. A useful catalyst for my process is a cerium-zirconium-cobalt-manganese-bromine catalyst wherein the molecular ratio of cerium to cobalt is about 1:2 to about 1:25, and the molecular ratio of zirconium to cobalt is about 1 to about 10 to about 1 to about 100 and the oxidation is conducted at a temperature in the range of about 100° C. to about 220° C., which process comprises conducting an oxidation of the pseudocumene so that the first stage is a continuous or alternatively is a batch stage oxidation of PSC so that the concentration of bromine in the first stage is 0 to about 0.5 mole per mole of metals while all the remaining bromine is added during the second stage. The total amount of bromine added is about 30 to about 180 weight percent of the total metal catalysts present. The reaction is completed in a non-continuous process at a temperature of about 140° C. to about 250° C. and, if desired, the solvent and water of reaction is withdrawn during the last 5 to about 20 percent of the period of the reaction, usually during the last 5 to 20 minutes of the reaction, thus leaving higher TMLA of PA concentrations in the liquid-phase oxidation reactor effluent. In this process, the cerium is added during the second stage.
In an advantageous embodiment of my process for the oxidation of PSC with molecular oxygen to TMLA under liquid-phase conditions in the presence of a cerium-zirconium-cobalt-manganese-bromine catalyst, the atomic ratio of zirconium to cobalt is about 1:10 to about 1:100. The atomic ratio of cerium to cobalt is about 1:2 to about 1:25, and the initial temperature is in the range of about 100° C. to about 220° C. This process comprises conducting an oxidation of the PSC so that in the first stage the amount of bromine added is below about 35 weight percent of the total bromine to be added, and the cerium is added during the second stage. Also, this process comprises permitting only partial oxidation of the PSC, thus avoiding the poisoning of the catalyst and completing the reaction in a non-continuous process at a temperature of about 140° C. to about 175° C. to about 150° C. to about 250° C. During the last 5 to about 20 percent of the reaction time, the solvent and water of reaction are withdrawn leaving about 60 to about 75 weight percent solids in the crystallizer effluent.
In a suitable embodiment of my process for the oxidation of PSC with molecular oxygen to TMLA under liquid-phase conditions in the presence of a cerium-zirconium-cobalt-manganese-bromine catalyst, the molecular ratio of zirconium to cobalt is about 1:10 to about 1:100, and the molecular ratio of cerium to cobalt is about 1:2 to about 1:25. This process comprises conducting a semi-continuous or batch oxidation of the PSC so that in the first stage the amount of bromine added is below 20 weight percent of the total bromine to be added. The cerium is added during the second stage. The reaction is completed in a non-continuous process at a temperature of about 120° C. to about 175° C. to about 150° C. to about 250° C.
In an alternate embodiment, my process for the oxidation of PSC with molecular oxygen to TMLA under liquid-phase conditions is conducted in the presence of a cerium-cobalt-manganese-bromine catalyst. This process comprises conducting a semi-continuous or batch oxidation of pseudocumene so that in the first stage no bromine is added or not more than 35 percent of the total bromine is added. The reaction is completed with the addition of cerium in a non-continuous process at a temperature of about 120° C. to about 175° C. to about 150° C. to about 250° C.
It has now been discovered that my novel, staged cerium and bromine addition process can be further improved by running a semi-continuous oxidation at a partial conversion which is high enough so that the concentration of unreacted hydrocarbon is very low throughout the run, improving product quality and yields. The semi-continuous part of the oxidation is conducted so that the concentration of TMLA is low, usually about 1-5 mole percent, thus preventing premature catalyst deactivation, and the bromine concentration is zero or below 35 percent of the total bromine added. The total bromine added is about 0.5 to about 1.5 moles per mole of cobalt. Thus, the theoretical oxygen uptake is somewhere between 1 and 2.5 moles O 2 /mole hydrocarbon, with 1.5-2 moles being preferred. Because of side reactions, the actual oxygen uptake may be slightly higher. Also, the semicontinuous oxidation may be run at a low enough temperature, usually about 120° C. to about 200° C., to allow maintenance of an oxygen concentration above 0.5 percent in the vent gas, with 2-8 percent being preferred. After all the hydrocarbon has been pumped in, the oxidation is finished batchwise after the addition of cerium. In the batchwise step, the temperature of reaction is increased from about 140° C. to about 175° C. to about 150° C. to about 250° C. to compensate for the decreasing reaction rate. In this step, all, or at least 65 percent, of the bromine used in the catalyst is added including all of the cerium.
Clearly, the species, with one of the three methyl groups oxidized (dimethylbenzoic acids), are formed first, and their concentration is highest at 15-30 minutes. The monomethyl dicarboxylic acids are also formed early, but they peak at about 45 minutes into the run. The desired product, TMLA, does not appear in significant concentrations until about 45 minutes, but it then rises rapidly to its maximum at the conclusion of the run at 79 minutes.
In all of the embodiments and processes of this invention as described above it is, for a variety of reasons, preferable to conduct the oxidation of PSC to TMLA using an atomic ratio of bromine to total catalyst metals in the range of about 0.4:1 to about 0.7:1. These ratios of bromine-to-catalyst metals are particularly effective when cerium is added only during the last or, in the case of a two-stage reaction, the second stage of the pseudocumene oxidation reaction. The use of bromine-to-metals ratios in the range of about 0.4:1 to about 0.7:1 in conjunction with adding cerium only during the second stage of the oxidation results in improved yields of TMLA, a reduction in the levels of side products and, as evidenced by lower CO and CO 2 levels in the reactor effluent gas, reduced burning. The ability to use lower amounts of bromine also results in a cost saving. Finally, the lower bromine levels are less corrosive to the reactor metallurgy.
The following examples illustrate the preferred embodiment of this invention. It will be understood that the example are for illustrative purposes only and do not purport to be wholly definitive with respect to the conditions and scope of the invention.
EXAMPLE 1
The oxidation of pseudocumene is accomplished by bubbling air through a hot (320° F.) mixture of pseudocumene (225 g) with 420 g of 95% acetic acid in the presence of cobalt and manganese acetates and HBr and zirconium to 320° F. The base case concentration of cobalt is 0.18 wt. %, manganese is 0.084 wt. %, Zr is 0.004 wt. %, all based on pseudocumene. Hydrogen bromide is added to equal a 0.9 molar bromine-to-metals ratio, but only 20 percent of the total bromine is added at the beginning of the oxidation. The remainder is added gradually with the so-called tail-out catalyst which also includes some manganese (0.01 wt. %) and zirconium (0.004 wt. %).
The temperature is gradually ramped from 320° F. to 400° F. over the 60 minute run, and the pressure is also ramped from about 120 psig to 280 psig over the same period. After the oxidation the reactor contents are collected and analyzed.
EXAMPLE 2
This oxidation was carried out just as in Example 1, but the manganese in the initial mix was 0.12 wt. % of pseudocumene, the cobalt was 0.20%, and the bromine was added at a level which produced a total molar bromine-to-metals ratio of 0.5. The bromine addition was staged such that 80% of the bromine was added via the tail-out catalyst just as in Example 1.
EXAMPLE 3
This oxidation was carried out just as in Example 2, but cerium was added via the tail-out catalyst to a concentration of 0.06% of pseudocumene.
EXAMPLE 4
This oxidation was identical to that of Example 3, but the cobalt concentration was 0.18 wt. %, the initial manganese was 0.16 wt. %, and the cerium in the tail-out was 0.10 wt. %.
EXAMPLE 5
This oxidation was similar to Example 4, but the cerium was added to the initial mix instead of the tail-out catalyst. The cerium was added at a level of 0.08 wt. % of pseudocumene. The initial manganese was 0.14 wt. %, and the cobalt was 0.18 wt. % of pseudocumene.
Table 1 contains the yield breakdown for each of these examples and shows the impact of reducing the bromine as well as the impact of adding cerium into the tail-out catalyst. Comparing Examples 1 and 2 shows the positive effect of increasing the manganese and lowering the bromine. However, the yield increase was only 1.3%.
When cerium was added (compare Examples 3 and 4 with Example 2) the yield increase becomes 2.0-2.2 mole %. Example 5 shows that adding the cerium to the initial catalyst eliminates the benefits.
TABLE 1______________________________________Mole % Example Example Example Example ExampleYield 1 2 3 4 5______________________________________Trimellitic 90.0 91.3 92.2 92.4 89.7Interme- 0.9 0.8 0.6 0.6 1.4diatesLow 2.6 2.2 2.0 1.9 3.3BoilersHigh 1.8 1.5 1.5 1.3 1.4BoilersCO + CO.sub.2 4.7 4.2 3.7 3.9 4.2______________________________________
|
A process for the manufacture of trimelitic acid from pseudocumene is disclosed. The pseudocumene is oxidized in the presence of a cerium, cobalt, manganese, and optionally zirconium, bromine catalyst wherein all of the cerium is added in the second stage of the oxidation, and wherein most of the bromine is also added during the second oxidation stage. Trimellitic acid is useful in the manufacture of polyester and polyamide-imides.
| 2
|
This application is a continuation of application Ser. No. 08/630,388, filed Apr. 10, 1996, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to semiconductor fabrication and more particularly to an improved process for planarizing trench isolation regions of varying geometry.
2. Description of the Relevant Art
The fabrication of an integrated circuit involves placing numerous devices in a single semiconductor substrate. Select devices are interconnected by a conductor which extends over a dielectric which separates or "isolates" those devices. Implementing an electrical path across a monolithic integrated circuit thereby involves selectively connecting isolated devices. When fabricating integrated circuits it must therefore be possible to isolate devices built into the substrate from one another. From this perspective, isolation technology is one of the critical aspects of fabricating a functional integrated circuit.
A popular isolation technology used for an MOS integrated circuit involves the process of locally oxidizing silicon. Local oxidation of silicon, or LOCOS process involves oxidizing field regions between devices. The oxide grown in field regions are termed field oxide, wherein field oxide is grown during the initial stages of integrated circuit fabrication, before source and drain implants are placed in device areas or active areas. By growing a thick field oxide in field regions pre-implanted with a channel-stop dopant, LOCOS processing serves to prevent the establishment of parasitic channels in the field regions.
While LOCOS has remained a popular isolation technology, there are several problems inherent with LOCOS. First, a growing field oxide extends laterally as a bird's-beak structure. In many instances, the bird's-beak structure can unacceptably encroach into the device active area. Second, the pre-implanted channel-stop dopant oftentimes redistributes during the high temperatures associated with field oxide growth. Redistribution of channel-stop dopant primarily affects the active area periphery causing problems known as narrow-width effects. Third, the thickness of field oxide causes large elevational disparities across the semiconductor topography between field and active regions. Topological disparities cause planarity problems which become severe as circuit critical dimensions shrink. Lastly, thermal oxide growth is significantly thinner in small field (i.e., field areas of small lateral dimension) regions relative to large field regions. In small field regions, a phenomenon known as field-oxide-thinning effect therefore occurs. Field-oxide-thinning produces problems with respect to field threshold voltages, interconnect-to-substrate capacitance, and field-edge leakage in small field regions between closely spaced active areas.
Many of the problems associated with LOCOS technology are alleviated by an isolation technique known as the "shallow trench process." Despite advances made to decrease bird's-beak, channel-stop encroachment and non-planarity, it appears that LOCOS technology is still inadequate for deep submicron MOS technologies. The shallow trench process is better suited for isolating densely spaced active devices having field regions less than one micron in lateral dimension.
The trench process involves the steps of etching a silicon substrate surface to a relatively shallow depth, e.g., between 0.3 to 0.5 microns, and then refilling the shallow trench with a deposited dielectric. Some trench processes include an interim step of growing oxide on trench walls prior to the trench being filled with a deposited dielectric. After the trench is filled, it is then planarized to complete the isolation structure.
The trench process eliminates bird's-beak and channel-stop dopant redistribution problems. In addition, the isolation structure is fully recessed, offering at least a potential for a planar surface. Still further, field-oxide thinning in narrow isolation spaces does not occur and the threshold voltage is constant as a function of channel width.
While the trench isolation process has many advantages over LOCOS, it cannot in all instances achieve complete global planarization across the entire semiconductor topography. The upper surface of fill dielectric in large isolation areas are at lower elevation levels than the upper surface of the fill dielectric in small isolation areas. Further, manipulation of the fill dielectric surface is needed to provide an elevationally uniform fill dielectric surface across both large isolation areas (e.g., greater than 2.0 microns per side) and small isolation areas (e.g., less than 1.0 micron per side). The trench process presents many additional problems besides that of local planarization. First, conventional chemical vapor deposition (CVD) processes exhibit a tendency to form cusps and/or voids at the midline between closely spaced active areas, hereinafter termed "silicon mesas." These voids can lead to reliability problems and inadequate isolation performance. Second, conventional planarization techniques used to remove the fill dielectric from the upper surface of silicon mesas may over etch the fill dielectric in the isolation areas relative to the silicon mesas. An over etched fill surface which is elevationally lower than an adjacent active area silicon mesa causes the mesa sidewall and corner to be partially exposed. Any exposure at the silicon mesa corner or sidewall causes inappropriate fringing field effects and/or parasitic sidewall conduction. It is therefore important when choosing a planarization method, that the method not expose the silicon mesa corner or sidewall. Lastly, it is important to protect the silicon mesa upper surface during the fill procedure and subsequently during planarization. The silicon mesa surface must be left in pristine condition so as to allow formation of a high quality gate or tunnel oxide thereon. Local thinning of the resulting gate and/or tunnel oxide cannot be tolerated in high density integrated circuits employing short channels.
SUMMARY OF THE INVENTION
The problems outlined above are in large part solved by an improved shallow trench process of the present invention. The shallow trench process hereof demonstrates substantially global planarization of both large and small trench isolation regions relative to silicon mesas. Moreover, the trench process protects the silicon mesa upper surface during the dielectric fill procedure and subsequent planarization procedure by configuring the silicon mesa upper surface with a unique combination of stacked layers. Preferably, the stacked layers are placed on the silicon substrate prior to trench formation. After the trench is formed, a fill dielectric (i.e., oxide) is deposited across the trench and stacked layers. The fill dielectric is preferably deposited from within a low pressure chemical vapor deposition (LPCVD) chamber. The oxide source material is suitably derived from a tetraethoxysilane source, generally referred to in the industry as "TEOS." Alternatively, the fill dielectric can be obtained from an atmospheric-pressure, ozone-TEOS source. In either instance, the TEOS source and LPCVD or atmospheric-pressure, ozone-enhanced TEOS produces a fill dielectric with minimal voids in small trench isolation regions.
The fill dielectric covering the trench isolation and silicon mesa regions is planarized by applying a chemical-mechanical polish step after small trench isolation regions are filled. One or more additional fill procedures may be necessary to fill any remaining, larger trenches which were not filled by the first fill procedure. Chemical-mechanical polish is reapplied to the second fill dielectric upper surface, and determination is then made as to whether global planarization has been achieved. If global planarization does not occur after the second fill and second chemical-mechanical polish, then the fill and polish steps are again repeated for as many times as necessary to fill larger isolation trenches. Between each fill and polish step, a masking step is used to selectively mask (or protect) fill dielectric in large isolation regions. The masking step prevents fill dielectric at the base of large isolation regions from being removed by an etch step. By masking the large isolation regions, small indentations are produced in the fill dielectric upper surface near the periphery of large isolation regions. Depending upon the size of the trench isolation region, the small indentations can be removed during the subsequent chemical-mechanical polish step. If the indentations are not removed, then the dielectric fill/mask/polish step is repeated as described above.
To ensure the corners and sidewalls of silicon mesa upper surfaces are not exposed, a carefully selected combination of layers are stacked across the silicon mesa upper surface. The stacked layers are selectively removed with careful control and attention paid to the rate at which fill dielectric in adjoining isolation trenches is removed. The patterned layers are chosen such that after their removal, the exposed silicon mesa upper surface is elevationally below the fill dielectric upper surface within isolation trenches. Further, the stacked layers are chosen to prevent damage to the underlying silicon mesa upper surface during the etch and/or chemical-mechanical polish processes. The gate and/or tunnel oxide subsequently formed on the exposed silicon mesa upper surface demonstrates improved quality of, e.g., higher charge breakdown voltage (Q BD ).
Broadly speaking, the present invention contemplates a method for forming a silicon mesa between a pair of trench isolation regions. The method comprises the steps of providing a silicon substrate of substantially uniform substrate thickness. A first oxide is then formed upon the silicon substrate. Thereafter, polysilicon is deposited upon the first oxide, followed by second oxide deposited upon the polysilicon. Finally, silicon nitride is deposited upon the second oxide. The resulting stack of silicon nitride, second oxide, polysilicon, first oxide, and a portion of the substrate thickness is removed to form a trench isolation region.
The present invention further contemplates a method for forming a planarized integrated circuit topography. The method includes the steps of removing layers of silicon nitride, oxide and polysilicon as well as a partial thickness of silicon substrate underlying the silicon nitride, oxide and polysilicon to form a spaced pair of isolation trenches within the semiconductor substrate. Thereafter, a first fill oxide is deposited within the pair of isolation trenches. A portion of the first fill oxide is removed except for that which has been selectively masked by photoresist. Thereafter, a second fill oxide is deposited to form indents within an upper surface of the second fill oxide in registry above the periphery of the region being masked. A chemical-mechanical polishing step is used to remove the indents and all fill oxide (first and second fill oxide) to an elevational level approximately equal to the median thickness of the silicon nitride layer. The remaining layers of silicon nitride, oxide and polysilicon are then removed from the silicon mesa surfaces in regions between respective pairs of isolation trenches.
The present invention still further contemplates a method for forming a planarized topography of dielectric material, wherein an integrated circuit topography comprises at least three silicon surfaces, or silicon mesas, extending from a silicon substrate. Two of the three silicon surfaces are spaced from each other a short distance, and two of the three silicon surfaces dissimilar from one of the first two silicon surfaces, are spaced from each other a long distance greater than the short distance. A first oxide fill layer is deposited upon the silicon surfaces and the silicon substrate, followed by a masking layer applied over the first oxide fill layer and across a portion of the long distance. The first oxide fill layer, except for the first oxide fill layer underlying the masking layer, is removed. A second oxide fill layer is deposited upon what remains of the first oxide fill layer to form indents within the upper surface of the second oxide layer underlying a periphery of the masking layer.
The present invention yet further contemplates a silicon mesa comprising a stack of first oxide, polysilicon, second oxide and silicon nitride layers placed over an elevationally raised silicon surface. The silicon mesa further comprises a laterally adjoining isolation trench filled with LPCVD oxide. The LPCVD oxide comprises an upper oxide surface of higher elevation than the elevationally raised silicon surface.
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 cross-section of a semiconductor substrate having a stacked set of layers formed thereon;
FIG. 2 illustrates the semiconductor substrate stacked layers of FIG. 1 patterned to form large and small trench isolation regions interspersed between silicon mesas;
FIG. 3 illustrates a first oxide fill layer deposited over the trench isolation regions and silicon mesas of FIG. 2;
FIG. 4 illustrates a masking material placed over a portion of the lower elevation plane of the large trench isolation region;
FIG. 5 illustrates an etch applied to the masked topography of FIG. 4;
FIG. 6 illustrates a second oxide fill layer deposited over the trench isolation regions and silicon mesas formed in FIG. 5;
FIG. 7 illustrates a chemical-mechanical polish applied to the silicon oxide upper surface of FIG. 6;
FIG. 8 illustrates removal of the stacked layers from the silicon mesas and the relative elevation levels of the silicon mesa and isolation region upper surfaces;
FIG. 9 is a detailed view along plane A of FIG. 3, showing a silicon mesa corner configured in a conventional fashion absent the stacked layers of FIG. 3; and
FIG. 10 is a detailed view along plane A, showing a silicon mesa corner after removal of the stacked layers according to present invention.
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 INVENTION
Turning now to drawings, FIG. 1 illustrates a partial cross-sectional view of a semiconductor substrate 10. Substrate 10, preferably made from a single crystal silicon source, includes an upper surface 12 upon which a plurality of stacked layers 14 are deposited. According to one embodiment, stacked layers 14 comprise a first oxide 16, polysilicon 18, second oxide 20 and nitride 22. First oxide 16 can be either deposited from a chemical vapor deposition (CVD) source or thermally grown to a thickness between, e.g., 100 to 300 angstroms. Polysilicon 18 is deposited either from an atmospheric pressure CVD (APCVD) or a low pressure CVD (LPCVD) system to a thickness between, e.g., 400 to 2000 angstroms. Second oxide 20 is deposited from a CVD chamber or grown from a thermal source to a thickness suitably similar to first oxide 16. Nitride 22 is deposited from a CVD chamber or a plasma source to a thickness between, e.g., 400 to 2000 angstroms. CVD techniques and the various feed gas compositions necessary to form layers 16 through 22 are generally known in the art. It is the particular combination of nitride 22 over second oxide 20, and second oxide 20 over polysilicon 18, and polysilicon 18 over first oxide 16 which imparts a benefit set forth hereinbelow. According to an alternative embodiment, second oxide 20 can be eliminated leaving nitride 22 deposited directly upon polysilicon 18. It is preferred, however, that the first embodiment be used to minimize stress at the nitride-polysilicon boundary, and to allow process control in the selective patterning and removal of layers.
FIG. 2 indicates a subsequent processing step to that shown in FIG. 1. Specifically, FIG. 2 illustrates selective patterning of stacked layers 14 and surface 12. Stacked layers 14 and substrate 10 are selectively removed through a series of etch steps beginning by selectively removing nitride 22. Nitride 22 is preferably dry etched using a chlorine species within the plasma. Combined with the chlorine species is typically polymer-forming species such as carbon which helps passivate the remaining nitride sidewall. The dry etch process is fairly selective to the underlying oxide, i.e., second oxide 20.
Once nitride 22 is selectively removed, underlying oxide 20 is removed using, e.g., a HF and H 2 O wet etch solution. Alternatively, a plasma etch using, for example, CHF 3 etchant can be used. In either instance, the etch material chosen demonstrates high selectivity to underlying polysilicon 18. Accordingly, the etch material assures, like nitride 22, that exposed second oxide 20 is fully removed. Polysilicon 18, exposed as a result of second oxide 20 selective removal, is then removed using a plasma etching scheme to achieve high selectivity to underlying first oxide 16. Poly 18 plasma etch material includes any halogen component such as fluorine or chlorine (i.e., BCl 3 , Cl 2 ), and may also include an SF 6 component. The plasma etch material removes exposed poly 18 in lieu of underlying first oxide 16. The resulting exposed first oxide 16 is removed using HF wet etch solution or dry etch separately or in combination with the nitride etch.
Whenever wet etching is called for, the wet etching process involves immersing the exposed (non-masked) surfaces in an etchant solution followed by, for example, a cleaning step involving deionized water. Plasma etching can be carried out using a parallel plate reactor configured in the plasma etch mode or reactive ion etch (RIE) mode. In either instance, wet etch or plasma etch conditions are chosen to carefully and controllably remove layer-by-layer select regions of stacked layers 14. The unique configuration of layers, and the method in which they are removed, ensures high selectivity to the underlying base material. Removal of the upper surface 12 is continued to a depth within substrate 10 but prior to removal of more than, for example, 0.3 to 0.5 microns as measured from upper surface 12. Thus, FIG. 2 illustrates the formation of isolation trenches 24 etched within substrate 10 to a depth of 0.3 to 0.5 microns. Isolation trenches 24 have substantially vertical sidewalls resulting from high selectivity to the masking function of patterned stacked layers 14'.
An LPCVD-deposited TEOS or an atmospheric-pressure ozone-TEOS is used to blanket deposit first fill oxide layer 26 across the entire wafer topography, including patterned stacked layers 14' and isolation trenches 24. It is understood that layer 26 may comprise several applications of oxide in order to fill small area isolation trenches, such as that shown in reference numeral 24'. The successive layers of oxide 28 form first fill oxide 26, as shown in FIG. 3. While first fill oxide 26 planarizes small isolation area 24' with substantially no voids, it cannot adequately fill large isolation area 24". A subsequent planarization process is needed to achieve global planarization across the entire wafer topography, i.e., across small isolation trenches 24' having a length less than 1.0 microns per side as well as across large isolation trenches 24" having a length greater than 2.0 microns per side.
FIG. 4 illustrates an initial processing step needed to achieve substantially full global planarization. In particular, a photoresist layer is selectively polymerized by mask 32 to present a hardened photoresist pattern 34, as shown. Hardened photoresist 34 is shown to be somewhat thin in cross-section, however, it is understood that the cross-sectional dimension will increase commensurate with the isolation trench area. Accordingly, FIG. 4 is shown only for illustrative purposes, and is not indicative of the size of all possible isolation trench of sizes and photoresist cross-sections.
FIG. 4, in combination with FIG. 5, illustrates the purpose of masking material 34 used to prevent etch removal of first fill oxide 26 underneath photoresist 34. In all other areas, first fill oxide 26 will be removed. In large isolation areas 24", the resulting first fill oxide 26 upper surface appears with spacers 36 on opposed silicon sidewalls 38. Spacers 36 extend toward one another and meet at or near first fill oxide 26 underlying photoresist 34. First fill oxide 26 is removed in small isolation trenches substantially flush with patterned stacked layers 14' upper surface. The reason for planarity in small isolation areas is due primarily to the planarization achieved by the previous fill steps. Although the fill steps cannot achieve global planarization, as shown in FIGS. 3-5, FIG. 6 illustrates a subsequent fill step used for planarizing large isolation region 24". The large isolation regions 24" are deemed those not capable of being filled with planarity by first fill oxide 26, and are thus those needing further fill and planarization steps described hereinbelow.
By depositing a second fill oxide 40 on top of the remaining first fill oxide 26, planarization of large isolation area trenches can be achieved. There may be instances when the second oxide, like the first oxide, requires patterned etch back, and the process repeated for a third oxide deposition. This process can be continued and repeated for as many oxides as are necessary to planarize large area isolation trenches. If the isolation trenches are relatively small in lateral dimension, then either one or two oxides is all that is needed. However, large area isolation trenches exceeding, for example, 50 to 100 microns might require numerous oxide deposition and selective etch back steps. FIGS. 3 through 6 illustrate, for brevity, only a first fill oxide 26 followed by a second fill oxide 40. Interposed between the first and second oxide deposition steps is a select removal step used in large area trenches which are not planarized by the step shown in FIG. 3.
Second fill oxide 40 may retain indents 44 upon its upper surface 42. Indents 44 are in alignment above the area between spacer 36 and the masked portion of first fill oxide 26. Indents 44 are therefore in registry about the periphery of large area isolation regions, a spaced distance inside that periphery as defined by spacer 36. Spacer 36, in combination with masked oxide 26 aids the deposition of second fill oxide 40 over area 24".
FIG. 7 illustrates a step subsequent to that shown in FIG. 6. Namely, global planarization is achieved by chemical-mechanical polishing (CMP) upper surface 42 across the entire wafer surface. Upper surface 42 is preferably removed to an elevational level near the mid line thickness of nitride layer 22. CMP removes indents 40 to present a globally planarized upper surface 42'.
Using the same process for removing exposed regions of stacked layers 14, the remaining patterned stacked layers 14' are shown removed in the process step of FIG. 8. The high selectivity demonstrated by the various wet etch and plasma etch routines set forth above, are purposefully used to remove patterned stacked layers 14' so as not to significantly etch surface 42 beyond that of the silicon mesa upper surface. It is preferred, however, that a wet etch solution of HF or hot phosphoric acid (H 3 PO 4 ) be used to strip the remaining nitride 22.
FIG. 8 illustrates the resulting structure having silicon mesa 45 upper surface 46 slightly recessed from the upper surface of filled isolation region 30. By carefully removing, according to the present features and process steps, patterned stacked layers 14' relative to filled isolation regions 30, the present process achieves the benefits of not exposing mesa 45 corners and sidewall. As such, present mesas 45 avoid two dimensional fringing fields and parasitic sidewall conductor problems associated with many conventional processes.
Referring now to FIG. 9, a conventional silicon mesa 50 corner and sidewall is shown according to detail A of FIG. 3. Typically, conventional mesa 50 utilizes an oxide layer 52 and a nitride layer 54 instead of the present patterned stacked layer configuration 14'. A problem of conventional trench isolation techniques is illustrated when nitride 54 is removed and the reaction between the formation of removed nitrogen species combines on the upper surface of silicon mesa 50. The removed nitride species accumulates on the silicon to form silicon nitride 56. Silicon nitride 56 results from what is often referred to as the Kooi effect, or more specifically termed the white ribbon effect. Residue of white ribbon silicon nitride 56 causes problems during subsequent gate oxidation. A gate oxide formed on the upper surface of silicon mesa 50 will be locally thin over silicon nitride 56, leading to narrow gate width problems. Material 56 may also include a thermally grown oxide which occurs after the trenches are formed. Material 56 oxide drives the nitride 54 in an upward direction at the corner of each silicon mesa. The thickening of oxide results from the absence of a poly buffer layer. Local oxide thickening may leave the uneven formation of gate oxide on silicon mesa 50.
FIG. 10 illustrates the present process, relative to the conventional process shown in FIG. 9. Specifically, FIG. 10 illustrates the purpose of polysilicon layer 18, as well as first oxide 16 and second oxide 20. Polysilicon 18, in combination with oxide 26 and 40, serves to buffer migration of nitrogen from etched nitrogen layer 22. Moreover, polysilicon 18 minimizes thermal growth of oxide at the sidewall corners. Accordingly, local areas of silicon nitride and thermal oxide do not form, and the problems of localized gate oxide thinning do not appear.
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is capable of applications with numerous types of MOS-processed circuits. Furthermore, it is to be understood that the form of the invention shown and described is to be taken as presently preferred embodiments. Various modifications and changes may be made to each and every processing step as would be obvious to a person skilled in the art having the benefit of this disclosure. It is intended that the following claims be interpreted to embrace all such modifications and changes and, accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
|
An isolation technique is provided for improving the overall planarity of filled isolation regions relative to adjacent silicon mesas. The isolation process results in a silicon mesa having enhanced mechanical and electrical properties. Planarity is performed by repeating the steps of filling isolation trenches, patterning large area isolation trenches, and refilling isolation trenches to present an upper surface having indents which can be readily removed by a chemical-mechanical polish. The silicon mesa upper surface is enhanced by utilizing a unique set of layers stacked upon the silicon substrate, and thereafter patterning the substrate to form raised silicon surfaces, or mesas, having the stacked layers thereon. The patterned, stacked layers include a unique combination of dissimilar compositions which, when removed, leave a silicon mesa upper surface which is recessed below the adjacent, filled trenches. The patterned stacked layers incorporate a polysilicon and/or oxide buffer which prevents deleterious migration of nitrogen from the overlying nitride layer to the underlying silicon mesa upper surface.
| 8
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/346,432, filed Jan. 7, 2002.
FIELD OF THE INVENTION
[0002] This invention relates to the field of data storage, and more particularly to write heads and methods for recording information on data storage media using near-field optical coupling structures.
BACKGROUND OF THE INVENTION
[0003] Magnetic recording heads are used in magnetic disc drive storage systems. Most magnetic recording heads used in such systems today are “longitudinal” magnetic recording heads. Longitudinal magnetic recording in its conventional form has been projected to suffer from superparamagnetic instabilities at densities above approximately 40 Gbit/in 2 . It is believed that reducing or changing the bit cell aspect ratio will extend this limit up to approximately 100 Gbit/in 2 . However, for recording densities above 100 Gbit/in 2 , different approaches will likely be necessary to overcome the limitations of longitudinal magnetic recording.
[0004] An alternative to longitudinal recording that overcomes at least some of the problems associated with the superparamagnetic effect is “perpendicular” magnetic recording. Perpendicular magnetic recording is believed to have the capability of extending recording densities well beyond the limits of longitudinal magnetic recording. Perpendicular magnetic recording heads for use with perpendicular magnetic storage media may include a pair of magnetically coupled poles, including a write pole having a relatively small bottom surface area and a return pole having a larger bottom surface area. A coil having a plurality of turns is located adjacent to the write pole for inducing a magnetic field between the pole and a soft underlayer of the storage media. The soft underlayer is located below a hard magnetic recording layer of the storage media and enhances the amplitude of the field produced by the write pole. In the recording process, an electric current in the coil energizes the write pole, which produces a magnetic field. The image of this field is produced in the soft underlayer to enhance the field strength produced in the magnetic media. Magnetic flux that emerges from the write pole passes into the soft underlayer and returns through the return flux pole. The return pole is located sufficiently far apart from the main write pole such that the material of the return pole does not affect the magnetic flux of the write pole, which is directed vertically into the hard layer of the storage media. This allows the use of storage media with higher coercive force, consequently, more stable bits can be stored in the media.
[0005] As the magnetic media grain size is reduced for high areal density recording, superparamagnetic instabilities become an issue. The superparamagnetic effect is most evident when the grain volume V is sufficiently small that the inequality K U V/k B T >40 can no longer be maintained. K u is the material's magnetic crystalline anisotropy energy density, k B is Boltzmann's constant, and T is absolute temperature. When this inequality is not satisfied, thermal energy demagnetizes the individual grains and the stored data bits will not be stable. Therefore, as the grain size is decreased in order to increase the areal density, a threshold is reached for a given material K u and temperature T such that stable data storage is no longer feasible.
[0006] The thermal stability can be improved by employing a recording medium formed of a material with a very high K u . However, the available recording heads are not able to provide a sufficient or high enough magnetic writing field to write on such a medium. Heat assisted magnetic recording, sometimes referred to as optical or thermal assisted recording, has been proposed to overcome at least some of the problems associated with the superparamagnetic effect. Heat assisted magnetic recording generally refers to the concept of locally heating a recording medium to reduce the coercivity of the recording medium so that an applied magnetic writing field can more easily direct the magnetization of the recording medium during the temporary magnetic softening of the recording medium caused by the heat source.
[0007] By heating the medium, the K u or the coercivity is reduced such that the magnetic write field is sufficient to write to the medium. Once the medium cools to ambient temperature, the medium has a sufficiently high value of coercivity to assure thermal stability of the recorded information. When applying a heat or light source to the medium, it is desirable to confine the heat or light to the track where writing is taking place and to generate the write field in close proximity to where the medium is heated to accomplish high areal density recording. The separation between the heated spot and the write field spot should be minimal or as small as possible so that writing may occur while the medium temperature is substantially above ambient temperature. This also provides for the efficient cooling of the medium once the writing is completed.
[0008] In order to increase areal density in an optically assisted write head, the spot size of the optical beam can be decreased by either decreasing the wavelength of the light or increasing the numerical aperture of the focusing elements. Other optical techniques which either directly or indirectly reduce the effective optical spot size are generally referred to as “superresolution” techniques. For example, it is well known that the resolving power of a microscope can be increased by placing an aperture with a pinhole (having a diameter smaller than the focused spot size) sufficiently close to the object being observed. As another example, tapered optical fibers have been used to achieve superresolution in near field scanning optical microscopy.
[0009] There is identified a need for an improved magnetic recording head that overcomes limitations, disadvantages, and/or shortcomings of known optically assisted magnetic recording heads.
SUMMARY OF THE INVENTION
[0010] This invention provides a recording head for use in conjunction with a magnetic storage medium, comprising a waveguide for providing a path for transmitting radiant energy; a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface; and means for applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy.
[0011] The recording head can further comprise a semi-reflective layer positioned in the path to form a resonant cavity with a surface of the magnetic storage medium. The means for applying a magnetic write field to the magnetic recording medium can comprise a magnetic yoke having a write pole, a return pole, and a coil for producing magnetic flux in the yoke, wherein the near-field coupling structure is position adjacent to the write pole.
[0012] The waveguide can comprise a transparent layer mounted adjacent to the write pole, wherein the write pole is located down track from the near-field coupling structure. The near-field coupling structure can form a square opening adjacent to the air bearing surface of the recording head.
[0013] The invention also encompasses a magnetic disc drive storage system comprising a housing; means for supporting a magnetic storage medium positioned in the housing; and means for positioning a recording head adjacent to the rotatable magnetic storage medium, wherein the recording head includes a waveguide for providing a path for transmitting radiant energy; a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface; and means for applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy.
[0014] The invention further encompasses a method of recording data on a data storage medium, comprising heating a section of the data storage medium by applying radiant energy to a waveguide including a transparent layer, a semi-reflective layer, and a near-field coupling structure at a frequency such that radiant energy resonates between the semi-reflective layer and a surface of the data storage medium; and applying a magnetic write field to the section of data storage medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a pictorial representation of a disc drive that can include a recording head constructed in accordance with this invention;
[0016] [0016]FIG. 2 is a side view of a recording head constructed in accordance with the invention;
[0017] [0017]FIG. 3 is a cross-sectional view of a portion of the waveguide of the recording head of FIG. 2;
[0018] [0018]FIG. 4 is a cross-sectional view of the portion of the waveguide of FIG. 3 taken in a plane perpendicular to the view shown in FIG. 3;
[0019] [0019]FIG. 5 is an isometric view of the near-filed coupling structure of the recording head of FIG. 2;
[0020] [0020]FIG. 6 is a side view of an alternative recording head constructed in accordance with the invention; and
[0021] [0021]FIG. 7 is a cross-sectional view of a portion of the waveguide of the recording head of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to the drawings, FIG. 1 is a pictorial representation of a disc drive 10 that can use a recording head constructed in accordance with this invention. The disc drive 10 includes a housing 12 (with the upper portion removed and the lower portion visible in this view) sized and configured to contain the various components of the disc drive. The disc drive 10 includes a spindle motor 14 for rotating at least one magnetic storage medium 16 . At least one arm 18 is contained within the housing 12 , with the arm 18 having a first end 20 for supporting a recording head or slider 22 , and a second end 24 pivotally mounted on a shaft by a bearing 26 . An actuator motor 28 is located at the arm's second end 24 for pivoting the arm 18 to position the recording head 22 over a desired sector or track of the disc 16 . The actuator motor 28 is controlled by a controller, which is not shown in this view and is well known in the art.
[0023] [0023]FIG. 2 is a partially schematic side view of a perpendicular magnetic recording head 30 constructed in accordance with the invention. The recording head includes a magnetic write head 32 that is constructed using known technology and includes a yoke 34 that forms a write pole 36 and a return pole 38 . The recording head 30 is positioned adjacent to a perpendicular magnetic storage medium 40 having a magnetically hard layer 42 and a magnetically soft layer 44 supported by a substrate 46 . An air bearing 48 separates the recording head from the storage medium by a distance D. A coil 50 is used to control the magnetization of the yoke to produce a write field at an end 52 of the write pole adjacent to an air bearing surface 54 of the write head. The recording head 30 can also include a read head, not shown, which may be any conventional type read head as is generally known in the art.
[0024] The perpendicular magnetic storage medium 40 is positioned adjacent to or under the recording head 30 and travels in the direction of arrow A. The recording medium 40 includes a substrate 46 , which may be made of any suitable material such as ceramic glass or amorphous glass. A soft magnetic underlayer 44 is deposited on the substrate 46 . The soft magnetic underlayer 44 may be made of any suitable material such as, for example, alloys or multilayers having Co, Fe, Ni, Pd, Pt or Ru. A hard magnetic recording layer 42 is deposited on the soft underlayer 44 , with the perpendicular oriented magnetic domains 56 contained in the hard layer 42 . Suitable hard magnetic materials for the hard magnetic recording layer 42 may include at least one material selected from, for example, FePt or CoCrPt alloys having a relatively high anisotropy at ambient temperature.
[0025] The recording head 30 also includes means for heating the magnetic storage medium 40 proximate to where the write pole 36 applies the magnetic write field H to the storage medium 40 . Specifically, the means for heating includes an optical waveguide 58 formed by a transparent layer 60 . The optical waveguide 58 acts in association with a source 62 of radiant energy which transmits radiant energy via an optical fiber 64 that is in optical communication with the optical waveguide 60 . The radiant energy can be, for example, visible light, infrared or ultra violet radiation. The source provides for the generation of surface plasmons or guided modes that travel through the optical waveguide 58 toward a heat emission surface 66 that is formed along the air-bearing surface thereof. The transmitted radiant energy, generally designated by reference number 68 , passes from the heat emission surface 66 of the optical waveguide 58 to the surface of the storage medium for heating a localized area of the storage medium 40 , and particularly for heating a localized area of the hard magnetic layer 42 .
[0026] The source 62 may be, for example, a laser diode, or other suitable laser light source. At the surface of the medium 40 , the surface plasmons convert a portion of their energy into heat in the medium 40 . The transparent layer may be formed, for example, from a silica based material, such as SiO 2 . The transparent layer should be a non-conductive dielectric, and have extremely low optical absorption (high transmissivity). It will be appreciated that in addition to the transparent layer, the waveguide 58 may include an optional cladding layer, such as aluminum, positioned adjacent the transparent layer or an optional overcoat layer, such as an alumina oxide, for protecting the waveguide 58 .
[0027] In addition, the waveguide 58 includes a near-field coupling structure 70 for confining the radiant energy to the recording spot. Specifically as shown in FIGS. 3, 4 and 5 , the near-field coupling structure includes a plurality of arms 72 , 74 , 76 and 78 .
[0028] [0028]FIG. 3 is an enlarged cross-sectional view of a portion of the optical waveguide 58 . The waveguide includes a transparent layer 60 and first and second arms 72 and 74 , which in this embodiment are embedded within the transparent layer 60 . Arm 72 includes a first section 80 that is positioned substantially parallel the surface of the storage medium, and a second section 82 that extends from the first section toward the air bearing surface at a first angle θ 1 . Arm 74 includes a first section 84 that is positioned substantially parallel the surface of the storage medium, and a second section 86 that extends from the first section toward the air bearing surface at a second angle θ 2 . The ends 88 and 90 of the second sections of arms 72 and 74 are separated to form a gap 92 . The gap has a width that can be, for example, less than 50 nm. The width of the gap determines the breadth of the near radiation field, and the resulting thermal field in the medium is desired to be no larger than 50 nm in the largest dimension.
[0029] [0029]FIG. 4 is an enlarged cross-sectional view of the portion of the optical waveguide 58 of FIG. 3 taken in a plane perpendicular to the plane of FIG. 3. The waveguide is shown to further include third and fourth arms 76 and 78 , which are also embedded within the transparent layer. Arm 76 includes a first section 94 that is positioned substantially parallel the surface of the storage medium, and a second section 96 that extends from the first section toward the air bearing surface at a first angle θ 3 . Arm 78 includes a first section 98 that is positioned substantially parallel the surface of the storage medium, and a second section 100 that extends from the first section toward the air bearing surface at a second angle θ 4 . The ends 102 and 104 of the second sections of arms 76 and 78 are separated to form a gap 106 .
[0030] [0030]FIG. 5 is an isometric view of the arms 72 , 74 , 76 and 78 , which are positioned together to form the near-field coupling structure 70 . In this view, the bent sections of the arms are seen to have a trapezoidal shape. The ends of the arms form an opening 110 for passage of radiant energy from the light source. While the opening is illustrated as having a square shape, it will be appreciated that other shapes can be used. The arms should be made of excellent conductors in the optical frequency band, such as Au, Ag or Cu. The overall length of the arms, designated as L in FIGS. 3 and 4, can be determined by a resonant condition with the exciting radiation in the waveguide, so that the overall length of a pair of arms will be comparable to an integer multiple of half or full wavelengths of the radiation in the waveguide. This will achieve a resonant coupling condition. The overall length is the total span of the antenna formed by arms 72 , 74 , 76 and 78 . That is, for example, the distance from that outside edge of arm section 80 to the outside edge of arm section 84 in FIG. 3. This distance is distinct from, and independent of, the gap length of the structure. The opening or gap between the arms is comparable to the desired near radiation field extent, as indicated above.
[0031] To most effectively heat the recording medium 40 , the heat emission surface 66 of the optical waveguide 58 is preferably spaced apart from the medium 40 and, more specifically, spaced apart from the hard magnetic layer 42 , by a distance of about 2 nm to about 50 nm. It will be appreciated that the separation distance is also dependent on the fly height required to maintain acceptable reading and writing (electromagnetic coupling for heating) by the recording head 30 .
[0032] The write head of FIG. 2 allows for heating of the recording medium 40 in close proximity to the write pole 36 , which applies a magnetic write field H to the recording medium 40 . It also provides for the ability to align the waveguide 58 with the write pole 36 to maintain the heating application in the same track of the medium 40 where the writing is taking place. Locating the optical waveguide 58 adjacent to the write pole 36 , provides for increased writing efficiency due to the write field H being applied immediately down track from where the recording medium 40 has been heated. The hot spot will ideally raise the temperature of the medium 40 to approximately 200° C. The recording takes place at the thermal profile, which can also be called the thermal field or the thermal distribution, in the medium 40 for which the coercivity is equal to the applied recording field. Ideally, this thermal profile should be near the edge of the write pole 36 where the magnetic field gradients are the largest. This will record the sharpest transition in the medium 40 . The optical waveguide 58 may be integrally formed with the write pole 36 . In operation, the recording medium 40 passes under the recording head 30 , in the direction indicated by arrow A in FIG. 2. The source 62 transmits radiant energy via the optical fiber 64 to the optical waveguide 58 . The optical waveguide 58 transmits the optical energy for heating the storage medium 40 . More specifically, a localized area of the recording layer 42 is heated to lower the coercivity thereof prior to the write pole 36 applying a magnetic write field H to the recording medium 40 . Advantageously, this allows for higher coercivity storage media to be used while limiting the superparamagnetic instabilities that may occur with such recording media used for high recording densities.
[0033] At a down track location from where the medium 40 is heated, the magnetic write pole 36 applies a magnetic write field to the medium 40 for storing magnetic data in the recording medium 40 . The write field H is applied while the recording medium 40 remains at a sufficiently high temperature for lowering the coercivity of the recording medium 40 . This ensures that the write pole 36 can provide a sufficient or high enough magnetic write field to perform a write operation on the recording medium 40 . As described herein, the recording head 30 advantageously allows for the point of writing to be in close proximity to where the recording medium 40 is heated.
[0034] [0034]FIG. 6 is a side view of a recording head 112 that can be constructed in accordance with an alternative embodiment of the invention. In the embodiment of FIG. 6, a semitransparent layer 114 is added within a transparent layer 60 .
[0035] [0035]FIG. 7 is a cross-sectional view of a portion of the waveguide of FIG. 6. The semitransparent layer 114 , in combination with the surface of the data storage medium creates a resonant cavity 116 . The resonant cavity will enable “recycling” of the electromagnetic energy, and will thus enhance the throughput efficiency of the device. The height from the semitransparent layer to the reflecting surface can be comparable to an integer times half the wavelength of the radiation.
[0036] While particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials, and arrangements of parts may be made without departing from the scope of the invention as defined in the appended claims.
|
A recording head for use in conjunction with a magnetic storage medium, comprises a waveguide for providing a path for transmitting radiant energy, a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface, and means for applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy. A disc drive including the recording head and a method of recording data using the recording head are also provided.
| 6
|
BACKGROUND OF THE INVENTION
This invention relates to plotting apparatus in general and more particularly to an improved plotting apparatus wherein in operation, a modifying system introduces a significant time delay between the generation of a dependent variable quantity and the plotting thereof against an independent variable quantity.
The two quantities will hereinafter be referred to as the dependent variable and the independent variable, respectively.
The range of applications and usefulness of the present invention is best illustrated with specific reference to a spectrophotometer, both as regards the background discussion and the description of practical embodiments which follow.
In a spectrophotometric context, the dependent variable is identifiable with percentage sample transmission or absorption and the independent variable with wavenumber or wavelength scan. Reference to transmission and wavenumber will henceforth be assumed to include absorption and wavelength as possible respective alternatives.
Sample percentage transmission is generated in the form of a varying flux of suitable radiation handled by a modifying system that transduces the flux into correspondingly varying electrical signals, filters the signals to reduce their noise bandwith, routes them to the pen servo of a strip chart recorder and finally plots them as the ordinate against an absicssa slaved to the wavenumber scan.
The modifying system inevitably includes components with a finite, although substantially constant, electrical response. This, and the deliberate holding of electrical signals for the performance of specific functions within the system, such as digital computation, cause a time delay between the occurrence of a radiation flux change and the plotting of the corresponding electrical signal change that can be regarded as essentially fixed for any given instrument design and independent of any operational parameter selected.
The filter for limiting the noise bandwith is not, of course, one of the aforesaid components. Its response is strictly related to its time constant, which is one of the parameters that fundamentally affects the operation of a spectrophotometer and which, therefore, must be chosen with certain performance criteria in mind. This effectively means that the filter is bound to superimpose upon the fixed delay referred to a further delay which varies with the choice of its time constant. In other words: the total time delay introduced by the modifying system is variable.
While the modified sample transmission signal is being held up, the wavenumber scan is naturally proceeding at whatever rate the user has selected. By the time the electrical signal is recorded, the abscissa has moved ahead by a number of abscissa units, i.e., wavenumbers, which depends on the total signal delay encountered in the modifying system and the wavenumber scan rate is use. As a result, sample percentage transmission is plotted with a positional phase lag with respect to the wavenumber scan (assuming, of course, that corresponding instantaneous values of the two variable quantities are considered) and consequently fidelity of the plot must suffer.
More specifically, if the variable time delay and the fixed time dealy introudced by the modifying system are denoted as f and t, respectively, f+t is clearly the total time delay between the generation of sample percentage transmission as an optical signal and the corresponding electrical signal being recorded on the chart. Now, if S is the scan rate in wavenumbers per second, S(f+t) must naturally represent the wavenumbers scanned in time T, or in other words, the positional phase lead of the abscissa, which must, of course, be numerically equal to the positional phase lag of the plotted ordinate referred to the abscissa.
To appreciate the generality of the expression S(f+t), it will be sufficient to generalize the meaning of S as units of the independent variable passed per second.
It is assumed that the total time delay is substantially constant irrespective of the rate of change of the electrical signal or is made so by introducing suitable known means in the modifying system.
In the description that follows, the phrase "dependent phase lag" refers to the positional phase lag in plotting the dependent variable and the phrase "independent phase lead" refers to the positional phase lead in plotting the independent variable, both in terms of units of the independent variable. Furthermore, the phrase "phase tracking means" refers to the tracking of either the dependent phase lag or the independent phase lead, bearing in mind the equivalency therebetween as regards establishing the amount of dependent phase lag caused by the total time delay due to the modifying system.
It should be understood, moreover, that the term "plotting" refers to any suitable representation of the manner in which the dependent variable changes with respect to the independent variable and is in no way limited to the recording of a trace upon a chart. Computer printout or oscilloscope displays are examples of alternatives to be included within the meaning of the term.
SUMMARY OF THE INVENTION
The object of the present invention is to provide apparatus of the type defined above wherein means are included for enabling the effect of dependent phase lag to be substantially cancelled in the interest of plot fideltiy.
According to the present invention, there is provided in plotting apparatus of the type defined above, including a modifying system as referred to, phase tracking means and dependent phase lag compensating means responsive thereto for introducing any required compensating phase shift in the plot of the two variables that in operation will substantially cancel the effect of the dependent phase lag on plotting fidelity.
The above concept may be carried into effect by introducing the appropriate phase lead in the plotting of the dependent variable simply by introducing a phase lead in the generation of the dependent variable.
It may also be carried into effect by providing an appropriate phase lag in the plotting of the independent variable, such as by interposing such a lag between the generation of the independent variable and the plotting thereof.
The phase tracking means and the dependent phase lag compensating means may be adapted for cooperation either on a continuous or a stepwise basis, depending on whether the design of the plotting apparatus is such that the expression S(f+t) may vary continuously or in steps.
Apparatus for implementing the present invention for continuous operation may be embodied in a mechanical arrangement in which the phase tracking means comprise log and anti-log cams as well as an intermediate log adding device to produce a displacement representing a phase lead to be introduced in the generation of the dependent variable and the dependent phase lag compensating means comprise a suitable insertion device, e.g., a differential mechanism, for converting the displacement into the required phase lead.
The present invention may equally well be embodied in an electrical layout, such as one based on digital techniques which is particularly suitable where one master stepper motor is used to generate the independent variable, e.g., to provide the drive for the wavenumber scan in a spectrophotometer, and a slave stepper motor to produce the plot thereof, e.g., to drive a strip chart phased to the wavenumber scan in said spectrophotometer. The phase tracking means may be made to translate S(f+t) into the number of steps by which the slave stepper motor is leading, i.e., into the independent phase lead, and the dependent phase lag compensating means may be arranged to cause the start and stop of the slave stepper motor to be delayed relatively to the master stepper motor by that number of steps at the start and stop of the plotting operation.
A particularly convenient and simple way of providing for stepwise operation is to have an indexable multi-lobed rotary cam represent the phase tracking means, each lobe having a predetermined radius to produce, through a cam follower, a corresponding displacement which a differential device translates into a phase lead in the generation of the dependent variable. This solution has been found quite satisfactory in a spectrophotometer having what is known as "integrated mode" operation, meaning by this that the user may select only predetermined combinations of the three fundamental parameters: resolution, noise filter time constant and wavenumber scan rate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a mechanical arrangement for providing dependent phase lag compensation in a plotting apparatus, such as included in a spectrophotometer, in which the independent variable may be scanned at continuously variable rates;
FIG. 2 is a schematic diagram of an essentially mechanical arrangement for providing compensation in a plotting apparatus forming part of a spectrophotometer in which the independent variable may be scanned only at certain predetermined scan rates;
FIG. 3 is a perspective view detailing the cooperation of the phase tracking means and the dependent phase lag compensating means symbolized in FIG. 2; and
FIG. 4 is a block-logic diagram of an electrical layout for providing compensation in a plotting apparatus forming part of a spectrophotometer in which the independent variable may be scanned at continuously variable rates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The block diagram of FIG. 1 is assumed to relate to a plotting apparatus including a modifying system (not indicated), the response of which may be altered by the user through a control 1 which enables the time constant of a low pass filter in the system to be adjusted. Manipulation of control 1 rotates a cam 2, the contour of which cooperates with a cam follower to track the log of the sum of the variable time delay introduced by the system (said delay being identifiable with the filter time delay, which is proportional to the time constant selected by the user) and the fixed system delay. In terms of the notation referred to earlier, the displacement of said cam follower represents, therefore, the log of f+t. Similarly, manipulation of the scan rate control 3 for the independent variable rotates a cam 4 the contour of which cooperates with a cam follower in tracking the log of the scan rate. The two cam displacements are added together in a differential mechanism 5 to yield a displacement representing the log of the scan rate S multiplied by f+t. The output of the differential mechanism 5 drives the anti-log cam 6, the cam follower of which is displaced proportionally to S(f+t) and therefore tracks the independent phase lead.
A dependent phase lag compensating mechanism 7 introduces a phase lead in the generation of the dependent variable proportional to the displacement of the anti-log cam follower. The lead offsets the independent phase lead and consequently substantially cancels the effect of dependent phase lag on plotting fidelity. The manner in which it is introduced and the construction of mechanism 7 will be detailed below with reference to FIG. 3.
The schematic arrangement shown in FIG. 2 relates to a plotting apparatus forming part of spectrophotometer wherein only predetermined combinations (hereinafter called modes) of resolution, noise filter time constant and wavenumber scan rate may be selected by the user in what has already been referred to as the integrated mode of operation. The spectrophotometric parameters that concern the present embodiment of the invention are the time constant of the noise limiting low pass filter and the wave-number scan rate, since only these two parameters enter into the computation of S(f+f). The remaining parameter, resolution, has no specific role to play, but the selection thereof is accounted for in FIG. 2 for completeness in outlining the essentials of integrated mode operation.
In FIG. 2, two-way push-button switches 8 through 18 constitute the integrated mode control, enabling the user to select any one of eleven modes. When none of the switches is depressed, a series connection is established from positive DC supply point 19, through the winding of relay 20, through the upper contacts of said switches to negative ground 21, which connection causes the armature of relay 20 to be attracted and the relay contacts 20A to open. When any one of the switches 8 through 18 is depressed, the supply to relay 20 is interrupted, the contacts 20A are closed and an AC supply is extended through contacts 20A to the winding 22A of a shaded pole motor 22 integral in rotation with an eleven lobe cam 23, representing the phase tracking means, and ganged wafer switches 24A and 24B.
The switch 24A has a wiper 24A1 which as the motor 22 rotates sweeps over and against one or more of fixed contacts 24A2 to 24A12 until it meets the particular contact which through the switch which is depressed establishes a connection to ground 25 from the positive supply point 19 through the relay 20 whereupon the contacts 20A open and the motor 22 stops.
In FIG. 2, the switch 16 is shown in the depressed state and the wiper 24A1 has therefore been represented in alignment with fixed contact 24A4 connected to the lower contact of switch 16. Since for any mode selected there can only be one of contacts 24A2 to 24A12 which is connected to ground 25 through the wiper 24A1, there are eleven input combinations available for controlling the scan speed selector 26, in which one input is in logic state 0 and the remainder in a logic state of 1. With a logic 0 input established through the contact 24A4, the wavenumber scan rate associated with the mode activated by switch 16 is now selected.
Switch 24B, identical with switch 24A and having a wiper 24B1 in angular alignment with wiper 24A1, similarly provides selection of the filter time constant. To this end, resistors 27 to 37, for selecting the time constant, have one end connected in common to a line extending to filter time constant selector 38 and the other connected to one of contacts 24B2 to 24B12. The wiper 24B1 forms another connection to selector 38. In FIG. 2, resistor 35 has been selected and its value is designed to set a filter time constant which is appropriate for the mode selected by depressing switch 16.
Ganged with wipers 24A1 and 24B1, as well as cam 23, is an integrated mode slit-control cam 39 having as many lobes as the cam 23, i.e., 11. Each lobe cooperates with a cam follower 40 to route a mechanical displacement, representing the slit opening selected through the depression of the corresponding integrated mode switch, to the mechanical multiplier unit 41, to which there is also routed a mechanical displacement that is a function of the angular position of grating cam 42. Alternatively, if this function is first translated into log form by means of a log cam, a differential summing mechanism followed by an anti-log cam may be substituted for the multiplier 41. The output of the multiplier 41 controls resolution by adjusting the entry and exit slits 43 forming part of the spectrophotometer monochromator.
The function of the angular travel of grating cam 42 referred to hereinabove is designed to program the monochromator slits for constant energy at the detector of the spectrophotometer. The function generated by the cam 39 and follower 40 merely supplies a factor by which the first function is multiplied to superimpose an integrated mode resolution setting on the instantaneous setting given by the constant energy program.
Now, the dependent phase lag associated with each mode must be fixed because the parameters determining it are fixed. The radius of each of the eleven lobes of the cam 23 is proportioned in manufacture to represent the predetermined dependent phase lag associated with the corresponding mode. Consequently, the displacement of the cam follower 44 tracks the dependent phase lag from mode to mode in a stepwise fashion. This displacement is converted into a lead angle of the grating cam 42 through a differential mechanism 45, which represents the dependent phase lag compensating means and which will be described in greater detail later, with reference to FIG. 3.
It will be appreciated that no compensating lead angle is required when the spectrophotometer is used in a "time drive" mode to observe sample percentage transmission with respect to time at a chosen wavelength. Since wavelength is not scanned, no dependent phase lag can arise. Provision must, therefore, be made for cam follower 44 to be displaced to a position corresponding to zero compensation before the time drive is enabled. In FIG. 2, this is achieved by means of a shaded pole motor 46 provided with a disc 46A having a step 46B cut into its periphery for cooperation with the respective followers (not shown) of microswitches 46C and 46D, positioned 180° apart. The line L of an AC supply is extended to one end of the field winding 46I of motor 46 via a change-over switch 47 and whichever of microswitches 46C and 46D is made, the neutral N being permanently connected to the other end of field winding 46I.
When the switch 47 is in the position shown in FIG. 2 corresponding to "scan on", the follower of the microswitch 46C is accommodated in the step 46B and microswitch 46C is "off". Microswitch 46D, on the other hand, is "on" because its follower abuts against the unbroken periphery of the disc 46A. The disc 46A remains in the active position shown, corresponding to "scan on" until the switch 47 is changed over to the "scan off" position when the line L of the AC supply is extended to the motor 46 through the microswitch 46D. After the motor 46D has turned clockwise by 180°, switch 46D is broken and the motor stops at the rest position of the disc 46A, corresponding to "scan off". The motor 46 turns another 180° when the scan is switched on again, to stop once more at the active position of disc 46A.
Motor 46 drives an eccentric 46E, the rise of which acts on the prolongation of the follower arm 44B to lift the follower pin 44C of the cam 23 and urge the follower 44 against the pull exerted thereon by the spring 44A, to a datum angular position corresponding to zero dependent phase lag compensation, when the disc 46A is at its rest position following a scan stop.
When the disc 46A turns to its active position following the resumption of scan, the fall of the eccentric 46E faces the prolongation of the arm 44B and the spring 44A urges the follower pin 44C into contact with whichever lobe of the cam 23 has been selected through the operation of one of the switches 8 to 18. (Note that this arrangement is merely intended to convey in convenient diagrammatic form the mechanical function involved, without regard to constructional correspondence with the practical equivalent arrangement shown in FIG. 3.)
FIG. 3 depicts in particular the cooperation between the phase tracking means and the dependent phase lag compensating means represented in FIG. 2 by cam 23 (and follower 44) and unit 45, respectively.
In FIG. 3, a stepper motor 48, supplying the motive power for the entire spectrophotometer insofar as major functions are concerned, is coupled through a toothed belt 49, cooperating with toothed pulleys 50 and 51, to a main shaft 52 rotatable in bearings 53 and 54 supported in frame members 55 and 56 respectively.
Differential mechanism 45 comprises a bevel gear 45A pinned to main shaft 52, and spaced therefrom, a symmetrically disposed bevel gear 45B cut at one end of a cylindrical sleeve 45C rotatable with endwise location on main shaft 52. A generally cylindrical assembly 45D is located in the space between the gears 45A and 45B and is free to rotate on shaft 52. It comprises an upstanding section gear portion 45E and a radial stub 45F, the latter mounting a rotatable end-located bevel gear 45G meshing with both gears 45A and 45B, the three meshing gears being identical. The cylindrical sleeve 45C is formed at its other end into a bevel gear 45H engaging bevel gear 57 pinned to shaft 58, which drives the grating cam (not shown). The sector gear portion 45E meshes with sector gear 44D mounted for rotation with shaft 44E at one end of the follower arm 44B.
Shaded pole motor 22 drives a shaft 59 in a counterclockwise direction, the shaft 59 having pinned thereto the cam 23, against the contour of which the follower pin 44C is urged by the spring 44A secured to frame part 44F. An integrally machined assembly freely rotatable on shaft 59, behind cam 23, comprises eccentric 46E and gear 46F. The latter meshes with an identical gear 46G forming part of another integrally machined assembly, further including disc 46A provided with step 46B, the assembly being keyed to the motor shaft 46H.
Microswitch 46C is mounted on a frame part of motor 46 so that the follower 46C1 at the end of the follower arm 46C2 is resiliently urged towards the disc 46A. Microswitch 46D is similarly mounted at a diametrically opposite position and, therefore, cannot be seen in FIG. 3. The representations of motor 46 and disc 46A in FIG. 2 and FIG. 3, respectively, are consistent if one imagines that in FIG. 2 disc 46A is seen from the rear whereas in FIG. 3, it is seen from the front.
Shaft 59 is also made to drive a rotary switch 24 comprising switch wafers 24A and 24B.
Pin 44C acts as a follower of cam 23, and through a rearward extension, as follower of eccentric 46E. The instant "frozen" in FIG. 3 is the same as in FIG. 2, i.e., at scan start, except that cam 23 is in a different position. The follower 46C1 of microswitch 46C is therefore located in the step 46B and the pin 44C bears against cam 23 under the pull exerted by spring 44A, the restraint applied by the eccentric 46E having been removed.
Bearing in mind what has already been said about cam 23 in the description relating to FIG. 2, it is now clear that for any angular position of the follower arm 44 around the longitudinal axis of shaft 44E, as determined by the lobe of cam 23 that is engaged by the follower pin 44C, the sector gear 44D communicates a corresponding angular displacement to the sector gear portion 45E, which angular displacement through the action of bevel gear 45G meshing with bevel 45A (which is keyed, as stated above to shaft 52) and bevel gear 45B (which as was described is free to rotate on shaft 52), causes bevel gear 45B and, consequently, shaft 58 to acquire a lead angle over shaft 52 which cancels the effect, on the recorded plot, of the dependent phase lag associated with the mode selected.
In FIG. 3, the plot is assumed to be recorded on a strip chart (not shown) by a servo-positioned recording pen (not shown). The motion for the strip chart is derived from shaft 52 through bevel gear 60 pinned to shaft 52.
Bevel gear 60 meshes with a similar gear 61 pinned to shaft 62 rotatable in bearing 63 supported in frame part 64 (another bearing and support thereof must be imagined at the other end of shaft 62 shown broken in FIG. 3). Shaft 62 communicates with a sprocketed shaft (not shown) for transporting a strip chart provided with engaging perforations along its two longitudinal sides.
The shaft 59 has pinned thereto a bevel gear 65 cooperating with an identical bevel gear 66 pinned to shaft 67 rotatable in sleeve bearings 68 and 69 supported in frame part 70. The shaft 67 represents, in practical form, the command drive between the cam 23 and the cam 39 shown symbolically in FIG. 2.
Referring back to FIG. 2, it can now be readily seen that the manner in which the outputs of units 26 and 38, respectively, are utilized forms no part of the present invention and need not be described.
In describing the FIG. 1 embodiment, it was stated that the construction and operation of mechanism 7 would be detailed with reference to FIG. 3. That mechanism is in fact represented by the differential mechanism 45, the construction and operation of which has been amply covered in the foregoing description of FIG. 3. It is easy to imagine the follower of the anti-log cam 6 shown in FIG. 1 taking the place of the follower arm 44B in FIG. 3.
FIG. 4 is a block-logic diagram of an electrical implementation of the present invention. The arrangement of FIG. 4 is intended to enable dependent phase lag compensation to be applied for any selection of the three major spectrophotometer parameters. It is essentially capable of computing on a continuous basis the aforementioned general expression S(f + t) giving the wavenumber units (Δν) scanned during the total time delay caused by the modifying system, which is the independent phase lead, of course.
It does so by representing the abscissa lead over the ordinate as so many steps -- conveniently referred to as Delta-nu steps of the chart stepper motor. Having done so, it provides the logic for ensuring that at scan start, the wavenumber stepper motor is advanced by the Delta-nu steps with respect to the chart stepper motor and at scan stop, the chart stepper motor is adanced by the same Delta-nu steps with respect to the wavenumber stepper motor. In other words, at scan start, the chart stepper motor is held stationary and the wavenumber stepper motor is advanced by the Delta-nu steps, after which both motors drive; and at scan stop, the wavenumber stepper motor is stopped and the chart stepper motor is advanced by the Delta-nu steps, after which both motors stop. In this manner, the abscissa lead is effectively cancelled, which is tantamount to saying that the effect of dependent phase lag on plot fidelity is substantially cancelled.
The fixed system delay t is set in digital form in device 68. The filter time lag f, assumed to be available in analogue form through unit 69 (which may represent, for example, the rotational angle of a shaft as set either by the operator or through a servosystem enabling the third major parameter to be automatically determined once the other two major parameters are chosen by the operator) is digitized in digitizer 70. The digital outputs of units 68 and 69 are added together in adder 71, the output of which thus represents the first part of the computation, i.e., f + t.
The scan rate S, assumed to be available in analogue form through unit 72 (the parenthetical observation expressed in regard to unit 69 applies to unit 72 as well) is digitized in digitizer 73. The digital output of digitizer 73 and that of the adder 71 are multiplied in multiplier 74, the output of which represents the completion of the computation in terms of the number of steps by which the chart motor leads the ordinate. The cooperating parts so far described represent the phase tracking means.
Digitizers 70 and 73 would naturally be dispensed with if S and f were available in digital form from units 69 and 72 respectively.
In the scheme represented in FIG. 4 for suppressing the Delta-nu steps, i.e., cancelling the abscissa lead and therefore applying dependent phase lag compensation, an oscillator 75 supplies timing pulses through AND gate 76 to the pulse handling unit 77 from which timing pulses in a selected frequency ratio are available in channels A and B. The A channel extends through the AND gate 78 to the drive pulse generator 79 supplying the chart stepper motor 80. The B channel extends through the AND gate 81 to the drive pulse generator 82 supplying the wavenumber stepper motor 83. Clearly motors 80 and 83 are de-energized if the controlling inputs of AND gates 78 and 81, respectively, are in state 0.
The A output channel of unit 77 is in addition extended through AND gate 84 to a counter 85, the output of which is compared with the output of multiplier 74 in comparator 86. The output of comparator 86, which is in state 0 when its two inputs are not equal, is passed through OR gate 87 to form the controlling input of AND gate 78. It is also passed through inverter 88 and OR gate 89 to form the controlling input of AND gate 84.
A SCAN ON/OFF control 90 has an output logic state of 1 when the "ON" function is selected and this state commands the counter 85 to count up. Conversely, logic 0 will correspond to the "OFF" and "COUNT DOWN" functions being selected. The output state of control 90 is inverted by inverter 91 before forming an input of both OR gates 87 and 89.
Counter 85 is assumed to be reset to zero by a reset device 92 when the spectrophotometer is first switched on. The reset device 92 may be part of a re-setting arrangement which comes into operation by first reversing the wavenumber drive past the scan origin and then lining up scan origin and chart origin before an actual scan may commence in forward drive with counter 85 reset to zero.
Assume that the lining up process has been completed and that the "ON" function has been selected in control 90. The logic 1 output of control 90 will enable the AND gate 81 and by placing a logic 1 input on OR gate 93, whose other input is zero when counter 85 reads zero, will enable AND gate 76 so that the wavenumber stepper motor 83 is set in motion. It will also command the counter 85 to count up and through the inverter 91, it will cause a logic 0 input to be present at OR gates 87 and 89.
Now, the input to comparator 86 derived from multiplier 74 cannot at first be equal to that derived from counter 85, with the result that initially comparator 86 will have a logic 0 output which makes the other input and consequently the output of OR gate 87 also 0, this keeping the AND gate 78 disabled and the chart stepper motor 80 stationary. The 0 output state of comparator 86, inverted by inverter 88 gives the OR gate 89 an output state of 1 which enables the AND gate 84. With the wavenumber stepper motor 83 running and the chart stepper motor 80 stationary a count accumulates in counter 85 until the output state of the comparator 86 changes from 0 to 1 upon the equalization of its two inputs. When that happens, AND gate 84 is disabled, but the count in counter 85, now equal to the output of multiplier 74, remains stored therein. In addition, the output state of OR gate 87, and consequently, the state of the controlling input of AND gate 78, changes to 1 so that the chart motor 80 begins to drive.
When the "STOP" function is selected in control unit 90, the 0 output state resulting commands the counter 85 to count down; causes the AND gate 81 to be disabled, thus stopping the wavenumber stepper motor 83; places a logic 1 input through the inversion of the 0 state at inverter 91, on OR gate 87, thus keeping AND gate 78 enabled and the chart stepper motor 80 running; changes to 0 the input to OR gate 93 set to 1 when the "ON" scan function was selected (note that the other input of OR gate 93 is still at 1, and therefore, AND gate 76 is still enabled, because there is a count other than zero in counter 85); and, finally, places a logic 1 input on OR gate 80 and consequently, keeps AND gate 84 enabled. When the counter 85 resets to zero, both inputs of OR gate 93 are in a logic state 0 and the AND gate 76 is disabled. Thus, the stop function initiated through control unit 90 is finally made effective for both stepper motors.
The system so far described assumes that the timing pulses on channels A and B of unit 77 are in the frequency ratio of 1:1. Unit 77 is in fact designed to provide other frequency ratios to enable for example a comprehensive range of abscissa scale expansions to be included. When an abscissa scale other than ×1 (× stands for times) is required, the proper scale expansion factor is chosen through the expansion factor unit 94 which multiplies the output of the digitizer (or on the unit 72 if such unit provides a digital output) by that factor.
The general concept of the present invention, but with particular regard to the embodiments described with reference to FIGS. 1 to 4, is particularly useful in conjunction with the abscissa scale change systems detailed in applicant's copending U.S. patent application Ser. No. 716,301, filed Aug. 20, 1976, now U.S. Pat. No. 4,073,198, issued on February 14, 1978, and entitled "Apparatus for Changing the Speed Ratio Between First and Second Displaceable Members", the specification of which is being hereby incorporated by reference into the present application. Since the dependent phase lag is affected by scan rate, it would clearly be a tiresome task to reset the abscissa to compensate for said lag every time the scale abscissa was changed.
The invention is also useful, however, where no scale change system is employed. Referring once more to the case of a spectrophotometer, the abscissa would not read correctly unless the chart was accurately set against the wavenumber dial reading (assuming such reading could be relied upon) or against the peak of an accurately known band in the spectrum of a test sample.
The crucial point that need be emphasized is that the abscissa must be set when the instrument is not scanning and there is no means of telling whether the setting is correct until it has been verified through an actual run that a test peak appears at the correct abscissa value. Several runs may be required before satisfactory accuracy is achieved by trial and error. This is inconvenient enough where only one or two abscissa scales are provided. It becomes a serious disadvantage in the case of multi-scale instruments. The present invention thus avoids this problem by insuring that proper compensation is provided at all different operating scales.
|
In a plotting apparatus such as a spectrophotometer having a modifying system which introduces a phase lag between the occurrence of a change in a dependent variable quantity and plotting thereof against an independent variable quantity, in one embodiment, a cam is used to provide a quantity representing the dependent phase lag and the output of the cam is coupled to the driving system for the plotter so as to introduce therein a phase shift to compensate for the phase lag. In another, electrical embodiment the same object is accomplished by digitizing the phase lag and using the digital value to offset the wavenumber stepper motor and the chart stepper motor in the spectrophotometer with respect to each other.
| 6
|
[0001] This patent application claims priority to U.S. Provisional Patent Application No. 60/592,446 filed Jul. 30, 2004. The contents of to U.S. Provisional Patent Application No. 60/592,446 are hereby incorporated by reference.
BACKGROUND
[0002] The weight bearing walls, floors and ceilings of a large building are frequently constructed from steel reinforced concrete. Within each floor of these buildings, walls are installed to partition areas and form separate rooms in the building. The walls are formed from wallboards mounted on steel beam wall frames. The wallboards provide a solid and insulative wall surfaces but are not structural. The steel beam frames provide a strong surface to support the wallboards.
[0003] With reference to FIG. 1 , the steel beam wall frame 105 is made of a plurality of steel beam components, including: a floor runner 109 , studs 111 and a ceiling runner 115 . A ceiling runner 115 is a horizontal beam that defines the top edge of the wall and a floor runner 109 is a horizontal beam that defines the bottom edge of the wall. The studs are vertical pieces which are placed between the ceiling runner and floor runner. The studs are evenly spaced parallel to each other and perpendicular to the ceiling and floor runners. At the corners of the room, the ceiling and floor runners may be cut at 45 degree angles and the adjacent ceiling and floor runners are connected to form the 90 degree corners. The cross-section of these steel beams is designed to be structurally rigid while minimizing weight. The C-channel is a common cross section of a steel beam.
[0004] Conventional building practices include the initial laying out of markings on the floor showing wall locations in accordance with the floor plan. Thereafter, starting with an outer wall, a ceiling runner in the form of an inverted C-channel is secured to the concrete ceiling around the perimeter of the new wall. The next conventional step is to secure the floor runners, which are upwardly facing C-channels, to the floor along the perimeter walls. Thereafter, the spacing of the studs is determined. This involves laying out such spacing by applying markings to the channels of both of the upper and lower runners. The next step is to measure the distances between the lower runner and the ceiling runner in order to determine the length of the studs. The studs are then cut according to such measured lengths.
[0005] The cut studs are then stood in place free-stand within the ceiling and floor runners. The studs are secured to the ceiling runner at their upper ends and the floor runner at their lower ends. Screws or welds may be used to secure the studs to the ceiling and floor runners. Once the steel frame is constructed, the wallboard is attached to the studs with screws or other fasteners. The wallboards is then typically covered with plaster, textured and painted to conceal the screw holes.
[0006] Modem buildings are designed to resist damage during seismic activity by swaying with the movement rather than attempting to remain rigid. A problem with steel wall frames used in buildings placed in areas of high seismic activity is that as the building flexes, there is relative movement between the floors and ceilings of the buildings. Because traditional walls are secured to both the floor and ceiling, the wallboards tend to be damaged as the studs deflect with the movement. This bending of the studs frequently causes damage to the wallboard and fasteners. After the seismic activity is complete, the damaged walls must be repaired.
[0007] What is needed is a system that prevents steel wall frames from being damaged during an earthquake.
SUMMARY OF THE INVENTION
[0008] The inventive ceiling runner and wall system prevents damage within a building by providing a wall frame that is flexible both vertically and horizontally. The wall system has the basic configuration of vertical studs mounted between floor runners that are secured to the floors of the building and ceiling runners that are attached to the ceilings. The ceiling runner has channels that hold the tops of the studs in place but also allow the stud to slide vertically within the ceiling runner. There are no fasteners or other components that rigidly secure the stud to the inventive ceiling runner.
[0009] The ceiling runner also has mounting slots that are used to secure the ceiling runner to the ceiling but also allow the ceiling runner to move horizontally. Fasteners are placed in the slots of the ceiling runner and secure the ceiling runners vertically to the ceiling. The bodies of the fasteners fit loosely within the slot but the heads of the mounting bolts are wider than the slots so the fastener heads hold the ceiling runners to the ceiling. The fasteners are adjusted to minimize the friction between the ceiling runner and the fastener and ceiling surface. The loose fasteners allow the inventive ceiling runner to slide horizontally along the path of the mounting slots.
[0010] When a building that has the inventive interior wall system moves, the ceiling can move vertically and/or horizontally relative to the floor. If the distance between the floor and ceiling expands, the studs slide partially out of the ceiling runner channels. Conversely, if the distance between the floor and ceiling contracts, the studs slide further into the ceiling runner channels. If the movement of the building causes horizontal shearing between the floor and ceiling, the mounting slots allow the wall to move horizontally relative to the ceiling without damaging the wall. If the movement is perpendicular to the slots, the wall will rotate about the floor runner however the wall can rotate in this manner without sustaining any damage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a drawing of a prior art stud and runner wall system;
[0012] FIG. 2 a is a cross section view of the seismic wall system;
[0013] FIG. 2 b is a side view of the seismic wall system;
[0014] FIGS. 3 a is a cross section view of the ceiling runner;
[0015] FIG. 3 b is a side view of the inventive ceiling runner;
[0016] FIG. 3 c is a perspective view of the inventive ceiling runner;
[0017] FIG. 3 d is a bottom view of the inventive ceiling runner; and
[0018] FIG. 4 is a view of the fasteners and spacers used with the ceiling runner.
DETAILED DESCRIPTION
[0019] The inventive ceiling runner prevents seismic damage to interior walls of a building with a system that securely supports the wallboard but is not rigidly fasten the wall to the ceiling. The wall using the inventive ceiling runner may initially assembled by attaching the studs to the floor and ceiling runners as shown in FIG. 1 .
[0020] Interior walls for a building are first laid out in a plan before installing the walls. Measures are taken to determine the dimensions of the existing space as well as the lengths of the new walls. The dimensions are plotted to create a top view of the walls for the project. The spacing of the studs within the walls are determined by the wall height and the stud size. The walls are strengthened by with more studs and larger studs. Shorter walls do not require as much strength and can use smaller studs that are spaced farther apart. Higher walls require closer stud spacing and possibly larger studs. The standard spacing between studs is either 12″, 16″ or 24″ on the centers of the studs. See table 1 below.
TABLE 1 Stud Spacing 12″ 16″ 24″ Stud Size (in.) Allowable Wall Height (ft.-in.) 1-⅝ 7-10 7-1 6-2 2-½ 10-10 9-10 8-6 3-⅝ 14-4 13-0 11-5
[0021] After the walls have been designed, they are constructed. The studs and runners are cut to the required lengths. This cutting can be performed with aviator snips or circular saw with abrasive metal-cutting blade. The ceiling runner is attached to the ceiling. Drywall screws are used to attach the ceiling runner to joists. For parallel joists, C-runners spaced 24″ or less are used to bridge two joists. The ceiling runner is then installed across the bridges. The inventive ceiling runner has slots that the body of the fasteners are placed through. The heads of the fasteners are wider than the slots so the ceiling runners are supported by the fastener heads. The fasteners can slide within the slots allowing the entire ceiling runner to move horizontally relative to the ceiling. The runner slot and horizontal sliding movement will be described in more detail below.
[0022] A floor runner is installed directly below each ceiling runner. The floor runner may be more difficult to install if the building has concrete floors because powder-actuated fasteners may be required. If the building has wood subfloors, drywall screws can be used to fasten the floor runner. The studs are then inserted into the floor and ceiling runners. The stud can be attached to the floor runner with 7/16″ pan or wafer-head screws. The drywall is then attached to the studs typically with screw fasteners.
[0023] In the described method, the wall studs are installed after the runners have been attached to the floor and ceiling. In alternative embodiments, the studs and runners can be assembled before the wall is positioned within the building. In this alternative method, the wall assembly of runners and studs may be assembled like a normal wall frame but without any fasteners attached between the stud and the ceiling runner. The assembled wall is then moved into position in the building. The floor runners are attached to the floor of the building and the ceiling runners are attached to the ceiling. The wallboard is attached to the studs but not the ceiling runner. Because the tops of the studs are not fastened to the ceiling runner, a manufacturing step eliminating and construction speed is increased.
[0024] The inventive ceiling runner is a substantial improvement over the prior art because it is less prone to damage when the building moves as a result of an external force such as an earthquake. A rigid wall can easily be damaged by relative movement between the ceiling and floor. With a rigid wall assembly, if there is horizontal movement, the studs are forced out of vertical alignment causing damage to the wallboard. Similarly, if there is vertical movement, the fasteners holding the studs to the floor and ceiling runners can be damaged and the wall is exposed to compression or tension.
[0025] The inventive ceiling runner overcomes these problems by allowing the ceiling to move both vertically and horizontally without any damage to the wall. With reference to FIGS. 2 a and 2 b, the studs 205 are placed in slots in the ceiling runner 215 and are not rigidly connected with a fastener or a weld. The ceiling runner 215 is loosely attached to the ceiling 231 with fasteners 241 and the floor runner 209 is attached the floor 233 with fasteners 243 . If there is vertical movement, the stud 205 slides within the ceiling runner 215 . This eliminates any vertical forces that are applied to the floor 207 or ceiling 209 from being transmitted to the studs 205 .
[0026] The fasteners 241 hold the ceiling runner 215 in place vertically, but allow the ceiling runner 215 some horizontal movement. If the ceiling 231 moves horizontally in line with ceiling runner 215 , the ceiling runner 215 and wall assembly remain stationary relative to the floor 233 . The horizontal ceiling 231 movement causes the fasteners 241 to slide within the slots in the web of the ceiling runner 215 . This horizontal sliding capability also allows the studs 205 to remain in a straight vertical orientation perpendicular to the ceiling runner 215 and the floor runner 209 . The vertical studs 205 keep the wall square so the wall board attached to the studs 205 will not be damaged, i.e. the wall remains rectangular rather than being forced into a slanted parallelogram.
[0027] A more detailed illustration of the inventive ceiling runner is shown in FIGS. 3 a - 3 d. The inventive ceiling runner 301 has a modified C-channel cross section 303 . The C-channel cross section 303 has a “web” 311 which is a horizontal section, two “flanges” 315 which extend vertically down from the web, and two “returns” 319 which extend inward from the flanges 315 . The returns 319 are notched so that portions of the C-channel do not have returns. These notched sections 321 of the C-channel are designed to accommodate the ends of the studs (not shown) which fit between the flanges 315 of the ceiling runner 301 . The notched sections 321 allow the steel studs to move up and down within the ceiling runner 301 . In the installed configuration there are no screws, weld attachments or fasteners holding the stud within the ceiling runner 301 . The notched sections 321 do prevent any significant horizontal or axial rotation movement of the studs. Although the returns 319 are shown as very short sections, it is also possible for these to extend partially or entirely across the width of the ceiling runner 301 . This “floating” interconnection allows the wall frame to be flexible during an earthquake.
[0028] In another embodiment, the inventive ceiling runner has only a single return connected to only one of the flanges. This single return would still prevent horizontal movement of the top of the stud after it has been inserted into the inventive ceiling runner. However this single return design would not be as strong as the double return embodiment. Although the returns are illustrated as being at the upper edge of the flange, it is possible to form the returns from a different portion of the flange. A ceiling runner can be formed from a C-channel which originally only has a web and two flanges. The flange can be cut and bent inward to form the returns. Thus, the notches are created at the normal sections of the C-channel and the returns are formed at the sections where the flange is bent inward. Although the returns are illustrated as being bent at about 90 degrees inward from the flange, the return can be bent at any other inward angle as long as the edge of the return can engage the end of a stud and prevent horizontal movement.
[0029] In order for the ceiling runner to be able to slide, it is important to not have the fasteners tightly secured. Normally, construction workers use power screwdrivers or power wrenches to efficiently install all fasteners. The power tools are problematic because they inherently screw in all fasteners very tightly. To properly install the inventive runner, the fastener must be unscrewed to minimize the horizontal friction between the fastener and the ceiling runner.
[0030] In an embodiment, the over tightening of the fasteners to the ceiling runner can be accomplished by using a spacer. With reference to FIG. 4 , the spacer 461 is slightly longer than the thickness of the web 411 of the ceiling runner 415 and fits within the slot 425 in the web 411 . In this embodiment, the spacer 461 is placed around the fastener 441 to prevent the fastener 441 from tightly contacting the web 411 . The spacer 461 may be made of a plastic that allows the ceiling runner to slide with less friction than metal In another embodiment, the fastener 442 may have an integrated spacer 465 . This would eliminate the need to place the spacer 461 around each fastener 441 improving the efficiency of the installation. In yet embodiment, the spacer 467 may also include a flange 469 that would rest between the head of the fastener 441 and the web 411 of the ceiling runner 415 . Similarly, a washer can be used in combination with the spacer 465 . This flange 469 or washer is intended to further reduce the friction between the ceiling runner and the fasteners. By using a spacer with the fasteners, a worker can use the power tools to attach the fastener to the ceiling without having to loosen the fasteners to allow the ceiling runner to move horizontally.
[0031] The ceiling runner described may be fabricated from steel sheet metal which is bent into the specified C-channel cross section. Alternatively, the C-channel may be made using an extrusion process which uses a die. Once the C-channel is formed, the notches may be cut into the returns. In alternative embodiments, materials other than steel may be used to make the inventive ceiling runners.
[0032] The installation process for interior walls is simplified with the inventive ceiling runner. The ceiling and floor runners are installed first like the existing method, however, the studs are now inserted into the desired notched sections and then fastened to the floor runner only. Because the inventive ceiling runner holds the studs horizontally, there is no need to fasten the studs to the ceiling runner. The wallboards are then attached to the studs in the normal manner described above. Installation is simplified because the studs are not fastened to the ceiling runner and the fasteners are not removed after the wallboard installation.
[0033] Normally, the studs are placed at uniform intervals across the width of the wall. This interval may be 8, 16 or 24 inches. By forming notches at 8 inch intervals, the spacing of the studs can be any of these normal standards. Alternatively, the notches may be formed at 4 inch or 12 inch intervals. The 4 inch notch configuration allows the stud intervals to be 4, 8, 12, 16, 18 or 24 inches. The 12 inch notch confirmation allows the stud intervals to be 12 or 24 inches. Ceiling runners which have any other notch length interval can easily be fabricated. The slot in the web of the beam is used as bolt holes to attach the ceiling runner to the building's ceiling. The body of the bolt is screwed into the ceiling while the head of the bolt is wider than the slot and holds the ceiling runner to the ceiling.
[0034] The inventive ceiling runner comes in various sizes depending upon the building requirements. These dimensions and the physical characteristics of each size are listed in table 1. In the first column, the “depth” refers to the width of the ceiling runner. The numbers in the column are in inches, 250=2½ inches, 362=3⅝ inches, 400=4 inches, etc. The second column is the thickness of the sheet metal used to make the ceiling runner. The area is the cross sectional area of the ceiling runner. The weight is in pounds per foot length of the ceiling runner. The Section Modulus (Sx), Moment of Inertia for Deflection (Ixx), Effective Section Modulus (Sy) and Moment of Inertia (Iyy) are engineering characteristics for the ceiling beam which are not significantly altered by the inventive notch design.
[0035] Although the invention has been described with respect to the ceiling runner, it is also possible to use the inventive runner as a floor runner. By using a floor runner that has mounting slots in the web, the floor runner can also move horizontally. This may further reduce the damage to walls in an earthquake.
[0036] Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but merely providing illustrations of some of the presently preferred embodiment of this invention.
|
The wall system includes a ceiling runner, a floor runner and studs that are mounted between the ceiling runner and the floor runner. The ceiling runner is specially designed to allow for movement of the ceiling relative to the floor without damaging the wall. The ceiling runner design accommodates this movement with loose slots for the studs that allow for vertical movement and mounting slots that allow for vertical support but also allows for horizontal movement.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The application claims priority under 35 U.S.C. §119 and 35 U.S.C. §365 to Korean Patent Application No. 10-2016-0000950 filed on Jan. 5, 2016 and Korean Patent Application No. 10-2016-0072600 filed on Jun. 10, 2016, the entire content of the prior applications is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present application generally relates to refrigerator control technology.
BACKGROUND
[0003] In general, a refrigerator includes a plurality of storage compartments for storing a storage to be refrigerated or frozen, and one surface of each of the storage compartments is opened such that food can be inserted and withdrawn. The plurality of storage compartments includes a freezing compartment for freezing food and a refrigerating compartment for refrigerating food.
[0004] In a refrigerator, a freezing system in which refrigerant is circulated is driven. An apparatus configuring the freezing system includes a compressor, a condenser, an expansion device and an evaporator. The evaporator may include a first evaporator provided at one side of the refrigerating compartment and a second evaporator provided at one side of the freezing compartment.
[0005] Recently, a refrigerator including evaporators and expansion devices individually provided in freezing and refrigerating compartments was developed. This refrigerator controls each expansion device to adjust the amount of refrigerant supplied to each evaporator in a compressor, thereby respectively maintaining the internal temperatures of the freezing and refrigerating compartments at freezing and refrigerating temperatures.
SUMMARY
[0006] The present disclosure is related to a refrigerator for selectively performing load shift according to the load thereof and a method of controlling the same.
[0007] In general, one innovative aspect of the subject matter described in this specification can be embodied in a refrigerator including a compressor configured to compress a refrigerant; a condenser configured to condense the refrigerant; a first evaporator that is configured to evaporate the refrigerant condensed by the condenser, the evaporated refrigerant being configured to cool a refrigerating compartment; a second evaporator that is configured to evaporate the refrigerant condensed by the condenser, the evaporated refrigerant being configured to cool a freezing compartment; a first heat exchanger coupled to the first evaporator; a refrigerating-compartment expansion device that is coupled to the first heat exchanger and that is configured to expand the refrigerant and provide the expanded refrigerant to the first heat exchanger; a second heat exchanger coupled to the second evaporator; and a freezing-compartment expansion device that is coupled to the second heat exchanger and that is configured to expand the refrigerant and provide the expanded refrigerant to the second heat exchanger, wherein the first heat exchanger is configured to cool the second heat exchanger.
[0008] The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In particular, one embodiment includes all the following features in combination. The freezing-compartment expansion device includes: a first expansion device coupled to an inlet side of the second heat exchanger, and a second expansion device coupled to an outlet side of the second heat exchanger, and wherein the refrigerant expanded by the second expansion device passes through the second evaporator. The refrigerator further includes a suction pipe that is configured to couple the second evaporator to the compressor, wherein the first expansion device, the second expansion device, and the suction pipe exchange heat with each other. A first surface of the first heat exchanger and a first surface of the second heat exchanger are coupled together. The refrigerator further includes a valve device that couples the condenser to the second heat exchanger and that is configured to control an amount of the refrigerant provided from the condenser to the second heat exchanger. The refrigerator further includes a first expansion device that is coupled to a first outlet side of the valve device and that is configured to expand the refrigerant that is provided to the second heat exchanger; and a second expansion device that is coupled to an outlet side of the second heat exchanger and that is configured to expand the refrigerant that is output from the second heat exchanger. The refrigerator further includes a third expansion device that is coupled to a second outlet side of the valve device and that is configured to expand the refrigerant that bypasses the second heat exchanger. Each of the first expansion device, the second expansion device, and the third expansion devices includes a respective capillary tube, and wherein a diameter of the capillary tube of the third expansion device is greater than a diameter of the capillary tube of the first expansion device or a diameter of the capillary tube of the second expansion device. The valve device includes a first valve including a first inlet, a first outlet, and a second outlet, and wherein the first valve is coupled to a first flow channel that extends from the first outlet of the first valve and that is coupled to the first expansion device, the second expansion device, and the second heat exchanger; and a second flow channel that extends from the second outlet of the first valve and that is coupled to the third expansion device. The refrigerator further includes: a coupler that couples the first flow channel to the second flow channel, wherein the coupler is coupled to an inlet side of the second evaporator. The compressor includes a first compressor configured to draw first refrigerant of the refrigerant and compress the first refrigerant, and a second compressor configured to draw second refrigerant of the refrigerant and compress the second refrigerant, and wherein the condenser includes a first condenser that is coupled to an outlet side of the first compressor and that is configured to condense the first refrigerant, and a second condenser that is coupled to an outlet side of the second compressor and that is configured to condense the second refrigerant. The compressor includes a first compressor, and a second compressor configured to draw second refrigerant of the refrigerant and compress the second refrigerant, and wherein the first compressor is configured to (i) draw first refrigerant of the refrigerant, the first refrigerant being evaporated by the first evaporator and (ii) compress the first refrigerant and the second refrigerant. The refrigerator further includes a second valve that includes a first inlet, a first outlet, a second outlet, and a third outlet, wherein the second valve is coupled to a first flow channel that extends from the first outlet of the second valve to the first heat exchanger; a second flow channel that extends from the second outlet of the second valve to the second heat exchanger; and a third flow channel that extends from the third outlet of the second valve to the second evaporator. The refrigerator further includes a refrigerating-compartment expansion device that is provided in the first flow channel and that is coupled to the first heat exchanger; a first expansion device that is provided in the second flow channel and that is coupled to the second heat exchanger; and a second expansion device that is provided in the second flow channel and that is coupled to the second heat exchanger. The refrigerator further includes: a third expansion device provided in the third flow channel.
[0009] In general, another innovative aspect of the subject matter described in this specification can be embodied in a method of controlling a refrigerator that includes (i) a first compressor, a first condenser, a first heat exchanger, and a first evaporator for a refrigerating-compartment cycle and (ii) a second compressor, a second condenser, a second heat exchanger, a freezing-compartment expansion device, and a second evaporator for a freezing-compartment cycle, wherein the first heat exchanger is configured to cool the second heat exchanger, the method including operations of sensing a temperature of an indoor space of the refrigerator; sensing cooling capacity of the second compressor; and controlling an amount of a refrigerant provided to the second heat exchanger based on the temperature of the indoor space or the cooling capacity of the second compressor.
[0010] The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In particular, one embodiment includes all the following features in combination. The method further includes determining that the cooling capacity of the second compressor satisfies a threshold cooling capacity; providing the refrigerant to the second heat exchanger based on the determination that the cooling capacity of the second compressor satisfies the threshold cooling capacity; and providing the refrigerant to the second evaporator based on the determination that the cooling capacity of the second compressor satisfies the threshold cooling capacity. The method further includes decompressing the refrigerant that is provided to the second heat exchanger; and decompressing the refrigerant that is provided to the second evaporator. The method further includes exchanging heat among (i) a suction pipe that extends from the second evaporator to the second compressor and (ii) one or more expansion devices of the freezing-compartment expansion device. The method further includes providing the refrigerant into two different channels using a three-way valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram illustrating an example refrigerator.
[0012] FIG. 2 is a diagram illustrating an example freezing cycle of a refrigerator.
[0013] FIG. 3 is a diagram illustrating an example heat exchanger.
[0014] FIG. 4 is a diagram illustrating example arrangements of refrigerant pipes.
[0015] FIG. 5 is a diagram illustrating an example refrigerator.
[0016] FIG. 6 is a graph illustrating an example P-H curve with reference to FIG. 2 .
[0017] FIG. 7 is a diagram illustrating an example refrigeration cycle of a refrigerator.
[0018] FIG. 8 is a diagram illustrating an example refrigerator.
[0019] FIG. 9 is a block diagram illustrating an example refrigerator.
[0020] FIG. 10 is a flowchart of an example process for controlling a refrigerator.
[0021] FIG. 11 is a diagram illustrating an example freezing cycle of a refrigerator.
[0022] FIG. 12 is a diagram illustrating an example refrigerator.
[0023] FIG. 13 is a graph illustrating an example P-H curve with reference to FIG. 11 .
[0024] FIG. 14 is a diagram illustrating an example freezing cycle of a refrigerator.
[0025] Like reference numbers and designations in the various drawings indicate like elements
DETAILED DESCRIPTION
[0026] FIG. 1 illustrates an example refrigerator. Referring to FIG. 1 , a refrigerator 1 includes a main body 11 having an openable front surface and forming storage compartments 12 and 13 . The storage compartments include the refrigerating compartment 12 and the freezing compartment 13 , and the refrigerating compartment 12 and the freezing compartment 13 may be partitioned by a partition 14 . The refrigerating compartment 12 and the freezing compartment 13 may be referred to as a “first storage compartment” and a “second storage compartment”, respectively.
[0027] The main body 11 may include an outer case 15 forming the appearance of the refrigerator 1 , a refrigerating-compartment inner case 16 provided inside the outer case 15 and forming the inside of the refrigerating compartment 12 and a freezing-compartment inner case (not shown) provided inside the outer case 15 and forming the inside of the freezing compartment 13 . An insulation material may be provided in a space between the outer case 15 and the freezing-compartment inner case 16 and a space between the outer case 15 and the freezing-compartment inner case.
[0028] In addition, the refrigerator 1 may further include a freezing-compartment door 21 and a refrigerating-compartment door 22 coupled to the front side of the main body 11 to selectively shield the freezing compartment 13 and the refrigerating compartment 12 .
[0029] In some implementations, for example, a bottom freezer type refrigerator in which a freezing compartment is provided under a refrigerating compartment will be described. However, the present application is not limited to the bottom freezer type refrigerator and is applicable to a top mount type refrigerator in which a freezing compartment is provided on a refrigerating compartment and a side-by-side type refrigerator in which a freezing compartment and a refrigerating compartment are provided side by side.
[0030] The refrigerating compartment 12 may include a cool-air discharger 18 for discharging air cooled in a first evaporator 140 to the refrigerating compartment 12 . The cool-air discharger 18 may be provided on the rear surface of the refrigerating compartment 12 and may be formed on a refrigerating-compartment cover plate 23 . A freezing-compartment cover plate (not shown), on which a cool-air discharger (not shown) for discharging cool air is formed, may be provided on the rear surface of the freezing compartment 13 .
[0031] FIG. 2 illustrates an example freezing cycle of a refrigerator. FIG. 3 illustrates an example heat exchanger. FIG. 4 illustrates example arrangements of refrigerant pipes. FIG. 5 illustrates an example refrigerator. FIG. 6 illustrates a graph showing an example P-H curve with reference to FIG. 2 .
[0032] First, referring to FIG. 2 , the refrigerator 1 includes a refrigerating-compartment cycle 10 for operating the refrigerating cycle for cooling the refrigerating compartment 12 and a freezing-compartment cycle 20 for operating the refrigerating cycle for cooling the freezing compartment 13 . First refrigerant may be circulated in the refrigerating-compartment cycle 10 and second refrigerant may be circulated in the freezing-compartment cycle 20 . The first and second refrigerants are not mixed or distributed to form independent cycles.
[0033] More specifically, the freezing-compartment cycle 10 includes a first compressor 100 as a “refrigerating-compartment compressor” for compressing the first refrigerant into high-temperature, high-pressure refrigerant, a first condenser 110 for condensing the high-temperature, high-pressure first refrigerant compressed by the first compressor 100 through heat radiation, a refrigerating-compartment expansion device 120 for decompressing the refrigerant condensed by the first condenser 110 , and a first evaporator 140 for evaporating the refrigerant decompressed by the refrigerating-compartment expansion device 120 .
[0034] The first condenser 110 may be provided in a mechanical compartment located at the rear side of the freezing compartment 13 as a “refrigerating-compartment condenser”. A first condensing fan 110 a may be provided at one side of the first condenser 110 . The first condensing fan 110 a may operate such that air in the mechanical compartment or air in an indoor space provided in the refrigerator flows toward the first condenser 110 .
[0035] The refrigerating-compartment expansion device 120 may include a capillary tube. The capillary tube has a relatively small diameter. The capillary tube may act as resistance to the flow of the refrigerant when the refrigerant passes through the capillary tube, thereby expanding the refrigerant. A first heat exchanger 130 may be provided between the refrigerating-compartment expansion device 120 and the first evaporator 140 . That is, the refrigerating-compartment expansion device 120 may be provided at the inlet side of the first heat exchanger 130 and the first evaporator 140 may be provided at the outlet side of the first heat exchanger 130 .
[0036] The first evaporator 140 may be provided at the rear side of the refrigerating compartment 12 as a “refrigerating-compartment evaporator”. A first evaporation fan 140 a may be provided at one side of the first evaporator 140 . The first evaporation fan 140 a may operate such that cool air in the refrigerating compartment 12 flows toward the first evaporator 140 . Air cooled while passing through the first evaporator 140 may flow into the refrigerating compartment 12 again.
[0037] The freezing-compartment cycle 20 includes a second compressor 200 as a “freezing-compartment compressor” for compressing the second refrigerant into high-temperature, high-pressure refrigerant, a second condenser 210 for condensing the high-temperature, high-pressure second refrigerant compressed by the second compressor 200 through heat radiation, freezing-compartment expansion devices 220 and 240 for decompressing the refrigerant condensed by the second condenser 210 and a second evaporator 250 for evaporating the refrigerant decompressed by the freezing-compartment expansion devices 220 and 240 .
[0038] The second condenser 210 may be provided in a mechanical compartment located at the rear side of the freezing compartment 13 as a “freezing-compartment condenser”. A second condensing fan 210 a may be provided at one side of the second condenser 210 . The second condensing fan 210 a may operate such that air in the mechanical compartment or air in an indoor space provided in the refrigerator flows toward the second condenser 210 .
[0039] The freezing-compartment expansion devices 220 and 240 include a plurality of expansion devices. The plurality of expansion devices includes the first expansion device 220 and the second expansion device 240 . Each of the first and second expansion devices 220 and 240 may include a capillary tube. A second heat exchanger 230 is provided between the first expansion devices 220 and 240 . That is, the first expansion device 220 may be provided at the inlet side of the second heat exchanger 230 and the second expansion device 240 may be provided at the outlet side of the second heat exchanger 230 .
[0040] The second evaporator 250 may be provided at the rear side of the freezing compartment 12 as a “freezing-compartment evaporator”. A second evaporation fan 250 a may be provided at one side of the second evaporator 250 . The second evaporation fan 250 a may operate such that cool air in the freezing compartment 13 flows toward the second evaporator 250 . Air cooled while passing through the second evaporator 250 may flow into the freezing compartment 12 again. The first evaporator 140 may be referred to as a “refrigerating-compartment evaporator” and the second evaporator 250 may be referred to as a “freezing-compartment evaporator”.
[0041] The refrigerator 1 may further include a device for shifting a load required for the freezing-compartment cycle 20 to the refrigerating-compartment cycle 10 . More specifically, the refrigerator 1 further includes an intermediate heat exchange unit 330 for exchanging heat between the refrigerating-compartment cycle 10 and the freezing-compartment cycle 20 .
[0042] The intermediate heat exchange unit 330 includes a first heat exchanger 130 provided in the refrigerating-compartment cycle 10 and a second exchanger 230 provided in the freezing-compartment cycle 20 . Heat may be exchanged between the first refrigerant passing through the first heat exchanger 130 and the second refrigerant passing through the second heat exchanger 230 .
[0043] The first heat exchanger 130 is provided at the outlet side of the refrigerating-compartment expansion device 120 . The first evaporator 140 may be provided at the outlet side of the first heat exchanger 130 . The temperature of the first refrigerant decompressed by the refrigerating-compartment expansion device 120 may be less than that of the second refrigerant flowing in the second heat exchanger 230 .
[0044] Accordingly, the first refrigerant may absorb heat from the second heat exchanger 230 while passing through the first heat exchanger 130 . In this process, the first refrigerant may be evaporated. Accordingly, the first heat exchanger 130 may be referred to as an “auxiliary evaporator”.
[0045] The second heat exchanger 230 may be provided at the outlet side of the freezing-compartment expansion device 220 . The second expansion device 240 may be provided at the outlet side of the second heat exchanger 230 . The second refrigerant decompressed by the freezing-compartment expansion device 220 may pass through the second heat exchanger 230 to radiate heat toward the first heat exchanger 130 . In this process, the second refrigerant may be supercooled. Accordingly, the second heat exchanger 230 may be referred to as an “auxiliary condenser”.
[0046] The first and second heat exchangers 130 and 230 may be provided adjacent to each other to perform heat exchange. More specifically, the first and second heat exchangers 130 and 230 may exchange heat using a conduction method according to mutual contact. For example, as shown in FIG. 3 , the first and second heat exchangers 130 and 230 may contact each other. The outer circumferential surface of the refrigerant pipe 135 of the first heat exchanger 130 and the outer circumferential surface of the refrigerant pipe 235 of the second heat exchanger 230 may be soldered.
[0047] The diameter of the first refrigerant pipe 135 of the first heat exchanger 130 may be greater than the refrigerant pipe 235 of the second heat exchanger 230 . More specifically, the refrigerant of the first refrigerant pipe 135 may be evaporated by heat exchange and the refrigerant of the second refrigerant pipe 235 is condensed. The volume of gaseous refrigerant is greater than that of liquefied refrigerant. When the diameter of the pipe in which the gaseous refrigerant flows is too small, drop of the pressure of the gaseous refrigerant increases and thus heat exchange efficiency may deteriorate. Accordingly, by increasing the diameter of the first refrigerant pipe 135 to be greater than that of the second refrigerant pipe 235 , it is possible to improve heat exchange efficiency of the intermediate heat exchange unit 330 .
[0048] As shown in FIGS. 2 and 3 , the first refrigerant flowing in the first heat exchanger 130 may flow in a direction opposite to the direction of the second refrigerant flowing in the second heat exchanger 230 . More specifically, some of the second refrigerant of the second refrigerant pipe 235 is condensed while heat is delivered to the first refrigerant of the first refrigerant pipe 135 . When the refrigerant flow directions of the first and second refrigerant pipes 135 and 235 are opposite to each other, the amount of condensed second refrigerant gradually increases toward the downstream side of the second refrigerant pipe 235 , thereby improving heat exchange efficiency.
[0049] The second expansion device 240 is provided at the outlet side of the second heat exchanger 230 to decompress the refrigerant supercooled by the second heat exchanger 230 . The refrigerant decompressed by the second heat exchanger 230 may be evaporated by the second evaporator 250 . The first evaporator 140 is provided at the outlet side of the first heat exchanger 130 and the refrigerant evaporated by the first heat exchanger 130 may be additionally evaporated by the first evaporator 140 .
[0050] The refrigerating-compartment cycle 10 further includes a first suction pipe 145 extending from the outlet side of the first evaporator 140 to the first compressor 100 . The first suction pipe 145 may exchange heat with the refrigerating-compartment expansion device 120 . For example, the first suction pipe 145 and the refrigerating-compartment expansion device 120 may be coupled to each other through soldering to perform heat exchange using the conduction method. The first suction pipe 145 and the refrigerating-compartment expansion device 120 form a first suction line heat exchange unit 160 .
[0051] Low-temperature refrigerant flowing in the first suction pipe 145 and relatively-high-temperature refrigerant passing through the refrigerating-compartment expansion device 120 exchange heat with each other, thereby increasing refrigerant overheating degree of the first suction pipe 145 and increasing the refrigerant supercooling degree of the refrigerating-compartment expansion device 120 . As a result, it is possible to improve operational efficiency of the refrigerating-compartment cycle 10 .
[0052] The freezing-compartment cycle 20 further includes a second suction pipe 255 extending from the outlet side of the second evaporator 250 to the second compressor 200 . The second suction pipe 255 may exchange heat with the first and second expansion devices 220 and 240 . For example, the second suction pipe 255 and the first and second expansion devices 220 and 240 may be coupled to each other through soldering to perform heat exchange using the conduction method. The second suction pipe 255 and the first and second expansion devices 220 and 240 form a second suction line heat exchange unit 260 .
[0053] Low-temperature refrigerant flowing in the second suction pipe 255 and relatively-high-temperature refrigerant passing through the first and second expansion devices 220 and 240 exchange heat with each other, thereby increasing refrigerant overheating degree of the second suction pipe 255 and increasing the refrigerant supercooling degree of the first and second expansion devices 220 and 240 . As a result, it is possible to improve operational efficiency of the freezing-compartment cycle 20 .
[0054] The flow of the refrigerant will be briefly described. First, the refrigerant is compressed by the first compressor 100 and the compressed refrigerant is condensed by the first condenser 110 . The condensed refrigerant is guided to the first heat exchanger 130 after passing through the refrigerating-compartment expansion device 120 . At this time, the refrigerating compartment expansion device 120 is soldered to the first suction pipe 145 connecting the first evaporator 140 to the first compressor 110 in the first suction line heat exchange unit 160 to exchange heat with each other, as shown in FIG. 5 .
[0055] The first heat exchanger 130 functions as an evaporator while exchanging heat with the second heat exchanger 230 in the intermediate heat exchange unit 330 and the refrigerant in the first heat exchanger 130 may be vaporized. The refrigerant may cool ambient air while passing through the first evaporator 140 to supply cool air to the refrigerating compartment 12 .
[0056] The refrigerant passing through the first evaporator 140 may be sucked into and compressed by the first compressor 100 through the first suction pipe 145 .
[0057] In some implementations, the refrigerant compressed by the second compressor 200 is guided into the second condenser 210 . The refrigerant is guided to the first expansion device 220 after passing through the second condenser 210 and the first expansion device 220 exchanges heat with the second suction pipe 255 connecting the first evaporator 250 to the second compressor 220 in the second suction line heat exchange unit 260 .
[0058] The refrigerant passing through the first expansion device 220 may flow into the second heat exchanger 230 and exchange heat with the first heat exchanger 130 . In this process, the refrigerant of the second heat exchanger 230 may be condensed.
[0059] Here, the condensation capacity of the refrigerant additionally condensed in the second heat exchanger 230 may correspond to a part “A” of FIG. 6 . By the part “A”, the load of the cooling cycle of the second compressor 200 is shifted to the cooling cycle of the first compressor 100 , thereby improving operational efficiency of the refrigerator. That is, since the refrigerant compressed by the second compressor 200 is additionally condensed in the part “A”, more cool air may be generated in the second evaporator 250 .
[0060] The refrigerant passing through the second heat exchanger 230 is guided to the second evaporator 250 after passing through the second expansion device 240 . At this time, the second expansion device 240 exchanges heat with the second suction pipe 255 in the second suction line heat exchange unit 260 .
[0061] The second evaporator 250 may exchange heat with ambient air passing therethrough to generate cool air and to supply the generated cool air to the freezing compartment. The refrigerant passing through the second evaporator 250 may be sucked into and compressed by the second compressor 200 through the second suction pipe 255 .
[0062] The intermediate exchange unit 330 including the first heat exchanger 130 and the second heat exchanger 230 may be provided at the rear side of the first evaporator 140 . More specifically, the intermediate heat exchanger unit 330 is manufactured in a refrigerant pipe structure shown in FIG. 5 and is provided between the outer case 15 and the refrigerating-compartment inner case 16 , the ends of the refrigerant pipes are connected to the other refrigerant pipes and then the refrigerant pipes are embedded by injecting an insulation material. The intermediate heat exchanger unit 330 is embedded in the insulation material such that heat exchange between the two refrigerant pipes is possible but heat exchange with ambient air is impossible.
[0063] If the intermediate heat exchange unit 330 is provided behind the second evaporator 250 , the second evaporator 250 is used to supply cool air to the freezing compartment and, at this time, the intermediate heat exchange unit 330 may function as a load of the freezing compartment. Accordingly, the intermediate heat exchange unit 330 is preferably provided behind the first evaporator 140 .
[0064] As compared to a refrigerator without the intermediate heat exchange unit 330 , cooling efficiency of the refrigerator can be improved.
[0065] FIG. 7 illustrates an example refrigeration cycle of a refrigerator. FIG. 8 illustrates an example refrigerator. Referring to FIGS. 7 and 8 , the refrigerator 1 a includes a refrigerating-compartment cycle 10 a and a freezing-compartment cycle 20 a.
[0066] The refrigerating-compartment cycle 10 a further includes a valve device 290 provided at the outlet side of the second condenser 210 to control the flow of refrigerant such that the refrigerant passing through the second condenser 210 selectively flows into the second heat exchanger 230 . For example, the valve device 290 may include a three-way valve having one inlet and two outlets.
[0067] The freezing-compartment cycle 20 a includes a first flow channel 294 extending from the first inlet 290 a of the valve device 290 to the second heat exchanger 230 and a second flow channel 295 extending from the second outlet 290 b of the valve device 290 to a coupler 276 of the first flow channel 294 . According to the control state of the valve device 290 , the refrigerant may flow through at least one of the first and second flow channels 294 and 295 .
[0068] When the valve device 290 is controlled such that the first flow channel 294 is opened and the second flow channel 295 is closed, the refrigerant flows into the second heat exchanger 230 to perform heat exchange in the intermediate heat exchange unit 330 . That is, the load of the freezing-compartment cycle 20 a is shifted to the refrigerating-compartment cycle 10 a, thereby obtaining supercooling effect of the refrigerating-compartment cycle 10 a. The load of the refrigerating compartment is less than that of the freezing compartment and the operational efficiency of the refrigerating-compartment cycle 10 a is higher than that of the freezing-compartment cycle 20 a, thereby improving the operation performance of the refrigerator.
[0069] In some implementations, when the valve device 290 is controlled such that the second flow channel 295 is opened and the first flow channel 294 is closed, the refrigerant may bypass the second heat exchanger 230 and flow toward the inlet side of the second evaporator 250 . That is, the shift of the load of the refrigerating-compartment cycle 10 a to the freezing-compartment cycle 20 a is restricted, thereby improving the cooling speed of the refrigerating compartment 12 .
[0070] In the first flow channel 294 , the first expansion device 220 , the second heat exchanger 230 and the second expansion device 240 may be provided. Accordingly, the refrigerant flowing in the first flow channel 294 may flow into the second evaporator 250 through the first expansion device 220 , the second heat exchanger 230 and the second expansion device 240 .
[0071] In the second flow channel 295 , a third expansion device 275 may be provided. The third expansion device 275 may be understood as a refrigerating-compartment expansion device. For example, the third expansion device 275 may include a capillary tube.
[0072] Accordingly, the refrigerant flowing in the second flow channel 295 may flow into the second evaporator 250 through the third expansion device 275 and the coupler 276 . The coupler 276 is a point where the first flow channel 294 and the second flow channel 295 meet and may be provided at the inlet side of the second evaporator 250 .
[0073] The length or diameter of the refrigerating-compartment expansion device 120 may be determined such that the decompression level of the refrigerating-compartment expansion device 120 is greater than that of the first expansion device 220 . For example, the diameter of the refrigerating-compartment expansion device 120 may be less than that of the first expansion device 220 . The length of the refrigerating-compartment expansion device 120 may be greater than that of the first expansion device 220 .
[0074] The diameter of the third expansion device 275 may be greater than that of the first expansion device 220 or the second expansion device 240 . For example, the diameter of the third expansion device 275 may be 0.9 mm and the diameter of the first and second expansion devices 220 and 240 may be 0.7 mm.
[0075] Accordingly, the flow resistivity of the refrigerant passing through the second flow channel 295 may be less than that of the refrigerant passing through the first flow channel 294 . As a result, the amount of refrigerant flowing when the second flow channel 295 is opened may be greater than that of refrigerant flowing when the first flow channel 294 is opened.
[0076] The valve device 290 may be controlled based on a load required for the refrigerator. For example, upon cooling operation or cooling-after-defrosting operation of the refrigerator, that is, if the load of the refrigerator is high, the valve device 290 is controlled to prevent heat exchange in the intermediate heat exchange unit 330 . That is, the valve device 290 is controlled such that the first outlet 290 a is closed and the second outlet 290 b is opened. Therefore, the refrigerant may flow in the second flow channel.
[0077] In this example, the amount of refrigerant flowing into the second evaporator 250 through the second flow channel 295 may increase, and the load of the freezing-compartment cycle 20 a may not be shifted to the refrigerating-compartment cycle 10 a, thereby rapidly performing cooling of the refrigerating compartment 12 .
[0078] In some implementations, if a stable cooling cycle is performed after cooling operation or cooling-after-defrosting operation of the refrigerator, that is, if the load of the refrigerator is low, the valve device 290 is controlled such that heat exchange is performed in the intermediate heat exchange unit 330 . That is, the valve device 290 is controlled such that the second outlet 290 b is closed and the first outlet 290 a is opened. Thus, the refrigerant may flow in the first flow channel 294 .
[0079] In this example, the amount of refrigerant flowing into the second evaporator 250 through the first flow channel 294 may be slightly low but the load of the freezing-compartment cycle 20 ′ may be shifted to the refrigerating-compartment cycle 10 ′, thereby improving the supercooling degree of the freezing-compartment cycle 20 ′.
[0080] The second suction pipe 255 may exchange heat with the first to third expansion devices 220 , 240 and 275 . For example, the second suction pipe 255 and the first to third expansion devices 220 , 240 and 275 are coupled to each other through soldering to perform heat exchange according to the conduction method. The second suction pipe 255 and the first to third expansion devices 220 , 240 and 275 form a second suction line heat exchange unit 260 .
[0081] Here, the third expansion device 275 may lengthily extend to be coupled with the first and second expansion devices 220 and 240 and the second suction pipe 255 . More specifically, the third expansion device 275 may include a first expansion part 275 a coupled with the first expansion device 220 and the second suction pipe 255 and a second expansion part 275 b coupled with the second expansion device 240 and the second suction pipe 255 as illustrated in FIG. 8 .
[0082] FIG. 9 illustrates an example refrigerator. FIG. 10 is a flowchart of an example process for controlling a refrigerator.
[0083] Referring to FIG. 9 , the refrigerator 1 a includes an indoor temperature sensor 351 for sensing the temperature of an indoor space where the refrigerator 1 a is provided, an indoor humidity sensor 352 for sensing the humidity of the indoor space and a compressor stroke sensor 353 for sensing the stroke of the second compressor 200 . The compressor stroke sensor 353 senses the stroke of reciprocal motion of a piston of the second compressor 200 . The stroke may be used to determine the cooling capacity of the second compressor 200 . Accordingly, the compressor stroke sensor 353 is understood as a “cooling capacity sensor”.
[0084] The refrigerator 1 a further includes a controller 350 for controlling operation of the first and second compressors 100 and 200 or the valve device 290 based on the temperature information sensed by the indoor temperature sensor 351 .
[0085] For example, if the indoor temperature sensed by the indoor temperature sensor 351 is equal to or greater than a predetermined temperature or if the refrigerator 1 a initially operates, the controller 350 may regard the load of the refrigerator 1 a as being high, increase the operating frequency of the first compressor 100 or the second compressor 200 , and increase the cooling capacity (stroke).
[0086] The indoor temperature information and the operating frequencies and cooling capacities of the first and second compressors 100 and 200 may be mapped and pre-stored. The operation state of the refrigerator 1 , that is, the condition related to the cooling operation, cooling-after-defrosting operation or stabilization operation and the operating frequencies and cooling capacities of the first and second compressors 100 and 200 may be mapped and pre-stored. Here, the “stabilization operation” may be understood as a state in which the pressure ranges of the refrigerating-compartment cycle 10 ′ and the freezing-compartment cycle 20 a reach a normal range to stably perform operation.
[0087] The controller 350 may determine the load of the refrigerator 1 a based on the cooling capacity sensed by the compressor stroke sensor 353 and adjust the control state of the valve device 290 .
[0088] Referring to FIG. 10 , the refrigerator 1 a is powered on and the cooling operations of the refrigerating compartment 12 and the freezing compartment 13 may be performed (S 11 ). Then, the temperature or humidity of the indoor space where the refrigerator 1 a is provided may be sensed (S 12 ).
[0089] Along with the operation state of the refrigerator 1 a, the cooling capacity of the second compressor 200 may be sensed. The cooling capacity of the second compressor 200 may be set to a value previously mapped based on the operation state of the refrigerator 1 a.
[0090] For example, if the cooling operation or cooling-after-defrosting operation of the refrigerator 1 is performed, since a relatively high load is required, the cooling capacity of the second compressor 200 may be determined to output first cooling capacity. The first cooling capacity is the highest cooling capacity and may be greater than predetermined cooling capacity.
[0091] In some implementations, if the cooling cycle of the refrigerator 1 a is stabilized, since a relatively low load is required, the cooling capacity of the second compressor 200 may be determined to output second cooling capacity. The second cooling capacity is less than the first cooling capacity and may be less than the predetermined cooling capacity (S 13 ).
[0092] Based on the operation state of the refrigerator 1 a and the cooling capacity of the second compressor 200 , the control state of the valve device 290 is determined. The control state of the valve device 290 may include a “first control state” for opening the first flow channel 294 and closing the second flow channel 295 , a “second control state” for opening the second flow channel 295 and closing the first flow channel 294 and a “third control state” for opening the first and second flow channels 294 and 295 .
[0093] Whether the condition of opening the first and second flow channels 294 and 295 is satisfied may be determined. For example, the condition may include the operation state from the start to the end of the defrosting operation after a rapid freezing operation is finished. At this time, the valve device 290 may be controlled to open the first and second outlets 290 a and 290 b and the operation of the second compressor 200 may be stopped (S 14 and S 21 ).
[0094] If the condition of opening the first and second flow channels 294 and 295 is not satisfied, whether the condition of shifting the load from the freezing-compartment cycle 20 to the refrigerating-compartment cycle 10 is satisfied may be determined
[0095] The condition that load shift is not performed may include the case where the second compressor 200 outputs the first cooling capacity, the case where the indoor temperature is relatively low or the case where the indoor humidity is relatively high. If the indoor temperature is relatively low, the density of the refrigerant circulated in the freezing-compartment cycle 20 may increase and thus the amount of gaseous refrigerant sucked into the first compressor 200 may decrease. Accordingly, the load of the refrigerator may increase and thus the amount of circulated refrigerant needs to increase.
[0096] If the indoor humidity is relatively high, the load needs to increase in order to prevent dew from being formed in the refrigerator and thus the amount of circulated refrigerant needs to increase.
[0097] In some implementations, load shift is not performed and the valve device 290 is switched to the second control state to close the first flow channel 294 and open the second flow channel 295 . Accordingly, the refrigerant may bypass the intermediate heat exchange unit 330 to flow toward the inlet side of the second evaporator 250 . As a result, since the refrigerant flows in the second flow channel 295 having relatively low flow resistivity, the amount of circulated refrigerant may increase (S 16 , S 19 and S 20 ).
[0098] The condition of performing load shift includes conditions other than the condition of opening the first and second flow channels 294 and 295 and the condition that load shift is not performed. In this example, the load of the refrigerator is recognized as being relatively low. Accordingly, the valve device 290 may be switched to the first control state to open the first flow channel 294 and close the second flow channel 295 . Accordingly, the refrigerant flows into the intermediate heat exchange unit 330 and exchanges heat with the refrigerating-compartment cycle 10 , thereby increasing the supercooling degree (S 17 and S 18 ).
[0099] According to the control method, by changing the control state of the valve device 290 according to the load of the refrigerator, the refrigerant may bypass the intermediate heat exchange unit 330 and flow in the second flow channel 295 having low flow resistivity if a large amount of refrigerant of the system is necessary, and the refrigerant may be guided to the intermediate heat exchange unit 330 if a large amount of refrigerant of the system is not necessary, thereby improving system performance and reducing power consumption.
[0100] FIG. 11 illustrates an example freezing cycle of a refrigerator. FIG. 12 illustrates an example refrigerator. FIG. 13 illustrates a graph showing an example P-H curve with reference to FIG. 11 .
[0101] Referring to FIGS. 11 to 13 , the refrigerator 1 b includes a plurality of devices for driving the freezing cycle.
[0102] More specifically, the refrigerator 1 b includes a plurality of compressors 400 and 500 for compressing refrigerant, a condenser 510 for condensing the refrigerant compressed by the plurality of compressors 400 and 500 , a plurality of expansion devices 420 , 520 and 540 for decompressing the refrigerant condensed by the condenser 510 and a plurality of evaporators 440 and 550 for evaporating the decompressed refrigerant by the plurality of expansion devices 420 , 520 and 540 .
[0103] The plurality of compressors 400 and 500 includes the first compressor 400 and the second compressor 500 . The second compressor 500 is a “low-pressure compressor” provided at a low pressure side to first-stage compress the refrigerant and the first compressor 400 is a “high-pressure compressor” for further compressing (second-stage compressing) the refrigerant compressed by the second compressor 500 . The second compressor 500 may be understood as a freezing-compartment cooling compressor and the second compressor 400 may be understood as a refrigerating-compartment cooling compressor.
[0104] The plurality of evaporators 440 and 550 includes the first evaporator 440 for generating cool air to be supplied to the refrigerating compartment and the second evaporator 550 for generating cool air to be supplied to the freezing compartment. The refrigerator 1 b may further include a condensation fan 510 a provided at one side of the condenser 510 and first and second evaporation fans 440 a and 550 a provided at one sides of the first and second evaporators 440 and 550 .
[0105] The refrigerator 1 b further includes a second suction pipe 555 extending from the outlet side of the second evaporator 550 to the inlet side of the second compressor 500 . Accordingly, the refrigerant passing through the second evaporator 550 may be sucked into the second compressor 500 .
[0106] The refrigerator 1 b further includes a first suction pipe 445 extending from the outlet side of the first evaporator 440 to the inlet side of the first compressor 400 and a coupler 505 where the first suction pipe 445 and the outlet-side refrigerant pipe, that is, a low-pressure discharge pipe 570 , of the second compressor 500 are coupled. Accordingly, the first-stage compressed refrigerant flowing the low-pressure discharge pipe 570 is coupled with the refrigerant passing through the first evaporator 440 in the coupler 505 and is sucked into the first compressor 400 . The refrigerant sucked into the first compressor 400 flows into the condenser 510 after being compressed.
[0107] The plurality of expansion devices 420 , 520 and 540 includes a refrigerating-compartment expansion device 420 for expanding the refrigerant which will flow into the first evaporator 440 . The refrigerator 1 b further includes a first heat exchanger 430 provided at the outlet side of the refrigerating-compartment expansion device 420 . The first evaporator 440 may be provided at the outlet side of the first heat exchanger 430 . The first heat exchanger 430 forms an intermediate heat exchange unit along with the second heat exchanger 530 and absorbs heat from the heat exchanger 530 to guide evaporation of the refrigerant.
[0108] The first suction pipe 445 and the refrigerating-compartment expansion device 420 may exchange heat with each other. For example, the first suction pipe 445 and the refrigerating-compartment expansion device 420 may be coupled to each other through soldering. By heat exchange, the supercooling degree of the refrigerant flowing in the refrigerating-compartment expansion device 420 and the overheating degree of the refrigerant flowing in the first suction pipe 445 can be improved. The first suction pipe 445 and the refrigerating-compartment expansion device 420 form a first suction line heat exchange unit 460 .
[0109] The plurality of expansion devices 420 , 520 and 540 further includes the first expansion device 520 and the second expansion device 540 . The refrigerator 1 b further includes a second heat exchanger 530 provided between the first and second expansion devices 520 and 540 . The refrigerant decompressed by the first expansion device 520 may be cooled by the second heat exchanger 530 and may be decompressed by the second expansion device 540 again. Then, the refrigerant decompressed by the second expansion device 540 may flow into the second evaporator 550 .
[0110] The second heat exchanger 530 may faun the intermediate heat exchange unit along with the first heat exchanger 430 and radiate heat to the second heat exchanger 530 to guide supercooling of the refrigerant.
[0111] The second suction pipe 555 and the freezing-compartment expansion devices 520 and 540 may exchange heat with each other. For example, the second suction pipe 555 and the freezing-compartment expansion devices 520 and 540 may be coupled to each other through soldering. By heat exchange, the supercooling degree of the refrigerant flowing in the freezing-compartment expansion devices 520 and 540 and the overheating degree of the refrigerant flowing in the second suction pipe 555 can be improved. The second suction pipe 555 and the freezing-compartment expansion devices 520 and 540 form a second suction line heat exchange unit 560 .
[0112] The refrigerator 1 b further includes a valve device 300 provided at the outlet side of the condenser 510 to control the flow of the refrigerant such that the refrigerant passing through the condenser 510 selectively flows into the first and second evaporators 440 and 550 . For example, the valve device 300 includes a three-way valve having one inlet and two outlets.
[0113] The refrigerator 1 b includes a first flow channel 301 extending from the first outlet 300 a of the valve device 300 to the first heat exchanger 430 and a second flow channel 302 extending from the second outlet 300 b of the valve device 300 to the second heat exchanger 530 . According to the control state of the valve device 600 , the refrigerant may flow through at least one of the first and second flow channels 301 and 302 .
[0114] The refrigerant branched to the first flow channel 301 by the valve device 300 is guided to the first heat exchanger after passing through the refrigerating-compartment expansion device 420 . The refrigerant absorbs external heat while primarily evaporating in the first heat exchanger 430 and further evaporates after passing through the first evaporator 440 , thereby supplying cool air to the refrigerating compartment. The refrigerant passing through the first evaporator 440 may be sucked into and compressed by the first compressor 400 through the first suction pipe 445 .
[0115] The refrigerant branched to the second flow channel 302 by the valve device 300 is guided to the first expansion device 520 and the first expansion device 520 exchanges heat with the second suction pipe 555 in the second suction line heat exchange unit 460 .
[0116] The refrigerant passing through the first expansion device 520 flows into the second heat exchanger 530 and the second heat exchanger 530 exchanges heat with the first heat exchanger 430 . In this process, some of the refrigerant of the second heat exchanger 530 may be condensed while radiating heat. That is, as shown in FIG. 13 , the refrigerant may be further condensed in a part “B” while passing through the second heat exchanger 530 . Since the load may be shifted upon cooling while the refrigerant passes through the part “B”, operational efficiency of the refrigerator can be improved.
[0117] The refrigerant passing through the second heat exchanger 530 is guided to the second evaporator 550 for supplying cool air to the freezing compartment after passing through the second expansion device 540 . At this time, the second expansion device 540 exchanges heat with the second suction pipe 555 . The second evaporator 550 may exchange heat with ambient air passing therethrough to generate cool air and the generated cool air may be supplied to the freezing compartment. The refrigerant passing through the second evaporator 550 may be sucked into and compressed by the second compressor 500 through the second suction pipe 555 .
[0118] FIG. 14 illustrates an example freezing cycle of a refrigerator. Referring to FIG. 14 , the refrigerator 1 c includes a plurality of compressors 400 and 500 for compressing refrigerant, a condenser 510 for condensing the refrigerant compressed by the plurality of compressors 400 and 500 , a plurality of expansion devices 420 , 520 , 540 and 575 for decompressing the refrigerant condensed by the condenser 510 and a plurality of evaporators 440 and 550 for evaporating the decompressed refrigerant by the plurality of expansion devices 420 , 520 , 540 and 575 .
[0119] The plurality of expansion devices 420 , 520 , 540 and 575 includes the refrigerating-compartment expansion device 420 for expanding the refrigerant flowing into the first evaporator 440 , the first expansion device 530 and the second expansion device 540 . The plurality of expansion devices 420 , 520 , 540 and 575 further includes the third expansion device 575 . The third expansion device 575 configures a freezing-compartment expansion device along with the first and second expansion devices 520 and 540 . The refrigerator 1 c further includes a valve device 600 provided at the outlet side of the condenser 510 to control the flow of the refrigerant such that the refrigerant passing through the condenser 510 selectively flows into the first and second evaporators 440 and 550 . For example, the valve device 600 includes a four-way valve having one inlet and three outlets. The valve device 600 may control the flow of the refrigerant such that the refrigerant selectively flows into the second heat exchanger 530 .
[0120] The refrigerator 1 c includes a first flow channel 601 extending from the first outlet 600 a of the valve device 600 to the first heat exchanger 430 , a second flow channel 602 extending from the second outlet 600 b of the valve device 600 to the second heat exchanger 530 , and a third flow channel 630 extending from the third outlet 600 c of the valve device 600 to the coupler 576 . According to the control state of the valve device 600 , the refrigerant may flow through at least one of the first to third flow channels 610 , 620 and 630 . When the valve device 600 is controlled such that the first and second flow channels 610 and 620 are opened and the third flow channel 630 is closed, the refrigerant may flow into the first and second heat exchangers 430 and 530 to perform heat exchange in the intermediate heat exchanger unit 330 . That is, the load of the freezing-compartment cycle 60 is shifted to the refrigerating-compartment cycle 50 , thereby obtaining supercooling effect of the refrigerating-compartment cycle 50 .
[0121] In some implementations, when the valve device 600 is controlled such that the first and third flow channels 610 and 630 are opened and the second flow channel 620 is closed, some of the refrigerant may flow into the first heat exchanger 430 but the remaining refrigerant may bypass the second heat exchanger 530 and flow toward the inlet side of the second evaporator 250 . That is, the shift of the load of the freezing-compartment cycle 60 to the refrigerating-compartment cycle 20 a is restricted, thereby improving the cooling speed of the refrigerating compartment 12 .
[0122] If cooling of the refrigerating compartment 12 is not necessary, the first flow channel 610 may be closed and the third flow channel may be opened, thereby operating only the freezing-compartment cycle 60 . Of course, at this time, heat exchange in the intermediate heat exchange units 430 and 530 may be restricted.
[0123] In the first flow channel 610 , the refrigerating-compartment expansion device 420 may be provided. Accordingly, the refrigerant flowing in the first flow channel 610 may flow into the first evaporator 440 through the refrigerating-compartment expansion device 420 and the first heat exchanger 430 .
[0124] In the second flow channel 620 , the first and second expansion devices 520 and 540 may be provided. Accordingly, the refrigerant flowing in the second flow channel 620 may flow into the second evaporator 250 through the first expansion device 520 , the second heat exchanger 530 and the second expansion device 540 .
[0125] In the third flow channel, the third expansion device 575 may be provided.
[0126] The three outlets of the valve device 600 may include the first outlet 600 a connected to the first flow channel 610 , the second outlet 600 b connected to the second flow channel 620 and the third outlet 600 c connected to the third flow channel 630 . The valve device 600 may be controlled to open at least one of the three outlets. The third flow channel 630 extends from the third outlet 600 c to the coupler 576 . The coupler 576 is a point where the second and third flow channels 620 and 630 meet and may be provided at the inlet side of the second evaporator 250 .
[0127] Each of the refrigerating-compartment expansion device 420 and the first to third expansion devices 520 , 540 and 575 may include a capillary tube.
[0128] The diameter of the third expansion device 575 may be greater than that of the first expansion device 520 or the second expansion device 540 . For example, the diameter of the third expansion device 575 may be 0.9 mm and the diameter of the first and second expansion devices 520 and 540 may be 0.7 mm.
[0129] Accordingly, the flow resistivity of the refrigerant passing through the third flow channel 630 may be less than that of the refrigerant passing through the second flow channel 620 . As a result, the amount of refrigerant flowing when the third flow channel 630 is opened may be greater than that of refrigerant flowing when the second flow channel 620 is opened.
[0130] Accordingly, in the refrigerator, to which a cooling system using two-stage compression is applied, the control state of the valve device 600 can be changed according to the load of the refrigerator. More specifically, if the load of the refrigerator is high and thus refrigerant flows in the third flow channel 630 , heat exchange in the intermediate heat exchange units 430 and 530 is not performed and the amount of refrigerant flowing into the second evaporator 550 through the third flow channel 630 may increase. As a result, since the load of the freezing-compartment cycle 60 is not shifted to the refrigerating-compartment cycle 50 , it is possible to rapidly perform cooling of the refrigerating compartment.
[0131] In some implementations, if the load of the refrigerator is low and thus the refrigerant flows into the second flow channel 250 , the amount of refrigerant flowing into the second evaporator 250 may slightly decrease but the load of the load of the freezing-compartment cycle 60 is shifted to the refrigerating-compartment cycle 50 , thereby improving the supercooling degree of the freezing-compartment cycle 60 .
[0132] The second suction pipe 555 and the freezing-compartment expansion devices 520 , 540 and 575 may exchange heat with each other. The second suction pipe 555 and the freezing-compartment expansion devices 520 , 540 and 575 may be coupled to each other through soldering. By heat exchange, the supercooling degree of the refrigerant flowing in the freezing-compartment expansion devices 520 , 540 and 575 and the overheating degree of the refrigerant flowing in the second suction pipe 555 can be improved.
[0133] The second suction pipe 555 and the freezing-compartment expansion devices 520 , 540 and 575 form a second suction line heat exchange unit 560 .
|
A refrigerator that includes a compressor configured to compress a refrigerant; a condenser configured to condense the refrigerant; a first evaporator that is configured to evaporate the refrigerant, the evaporated refrigerant being configured to cool a refrigerating compartment; a second evaporator that is configured to evaporate the refrigerant, the evaporated refrigerant being configured to cool a freezing compartment; a first heat exchanger; a refrigerating-compartment expansion device that is coupled to the first heat exchanger and that is configured to expand the refrigerant and provide the expanded refrigerant to the first heat exchanger; a second heat exchanger coupled to the second evaporator; and a freezing-compartment expansion device that is coupled to the second heat exchanger and that is configured to expand the refrigerant and provide the expanded refrigerant to the second heat exchanger, wherein the first heat exchanger is configured to cool the second heat exchanger is disclosed.
| 5
|
This application is a continuation-in-part of U.S. patent application Ser. No. 07/965,831 filed on Oct. 23, 1992, entitled "Selectively Actuatable Lighter," which issued on Aug. 29, 1995 as U.S. Pat. No. 5,445,518. U.S. patent application Ser. No. 07/965,831 is a continuation-in-part of U.S. patent application Ser. No. 07/723,989 filed on Jul. 1, 1991, entitled "Selectively Actuatable Lighter," which issued on Oct. 10, 1995 as U.S. Pat. No. 5,456,598, and is a continuation-in-part of U.S. patent application Ser. No. 07/912,421 filed on Jul. 10, 1992, entitled "Selectively Actuatable Lighter," abandoned. U.S. patent application Ser. No. 07/723,989 is a continuation-in-part of U.S. patent application 07/609,668 filed on Nov. 6, 1990, entitled "Selectively Actuatable Lighter," abandoned, which is a continuation of U.S. patent application Ser. No. 07/239,734 filed Sep. 2, 1988, entitled "Selectively Actuatable Lighter," which issued on Mar. 26, 1991 as U.S. Pat. No. 5,002,482. U.S. patent application Ser. No. 07/912,421 is a continuation of U.S. patent application Ser. No. 07/609,668 filed on Nov. 6, 1990, entitled "Selectively Actuatable Lighter," abandoned, which is a continuation of U.S. patent application Ser. No. 07/239,734 filed Sep. 2, 1988, entitled "Selectively Actuatable Lighter," which issued on Mar. 26, 1991 as U.S. Pat. No. 5,002,482.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to lighters which consume fuel such as, for example, butane which is stored in a reservoir in a liquid state, then passed through a valve means and finally ignited by a spark or other similar means. More particularly, the invention relates to a butane cigarette lighter having a feature which interferes with depression of a valve actuator and in turn hinders expulsion of fuel from a valve nozzle (i.e., fuel nozzle) and/or generation of sparks thereby rendering operation of the lighter by young children more difficult. Advantageously, this feature of the lighter may be deactivated by moving a latch to a non-interfering position, thus facilitating flame production. The present invention further includes an anti-defeat feature to increase the difficulty of disabling the latch.
2. Description of the Art
Numerous lighters are known, some of them incorporating features which are designed to render operation of the lighter more difficult by certain users. Some of such features relate to mechanisms which are designed to prevent ignition of a fuel source unless the lighter is properly oriented, mechanisms which are designed to automatically turn off a fuel source supply valve, and tamper protection arrangements.
More recently, attention has been directed toward preventing ready actuation of such lighters by persons normally not able to appreciate the potential danger of the flame. Individuals normally contemplated in these efforts are young children, in the age category of younger than five years.
U.S. Pat. No. 4,784,601 to Nitta relates to a gas lighter having an L-shaped slidable stopper which is positionable to prevent descent of a gas lever which controls fuel flow. The lighter is rendered operable by moving the stopper outward so that its vertical leg is displaced from the top surface of the lighter housing. The L-shaped slidable stopper must be manually moved into its locking position each time it is desired to lock the lighter.
U.S. Pat. No. 4,784,602 to Nitta relates to a gas lighter having an L-shaped slidable stopper which is positionable to prevent descent of a gas lever which controls fuel flow. The lighter is rendered operable by moving the stopper inward so that its vertical pin engages a hole in the surface of the lighter housing. The L-shaped slidable stopper must be manually moved into its locking position each time it is desired to lock the lighter.
U.S. Pat. No. 4,786,248 to Nitta relates to a piezoelectric lighter equipped with a thumb-latch slidable fitted within a lighter casing. The thumb latch is manually slidable into and out of a position which interferes with depression of a thumb-pusher. The lighter is rendered operable by manually sliding the thumb-latch to an unlocked position. After operation of the lighter a user must manually slide the thumb-latch to its locked position in order to lock the lighter.
U.S. Pat. No. 4,904,180 to Nitta relates to a piezoelectric lighter equipped with a lock means which automatically returns to a locked position after use of the lighter. The lock means includes a stopper and a leaf-spring which keeps the stopper urged toward the windshield. The lighter may only be operated after the stopper is drawn backwards, away from the windshield. The lighter cannot maintain the stopper in the drawn back position without the application of constant force by a user. That is, no means are provided to maintain the lighter in an unlocked configuration.
U.S. Pat. No. 1,895,032 to Fisher relates to a lighter in which a manual control means is movable out of engagement with a shoulder portion of the lighter so as to enable the manual control means to be depressed thereby causing the lighter to operate. The control means returns to its position in engagement with the shoulder portion after use of the lighter. The lighter cannot maintain the control means in its out of engagement position without the application of constant force by a user.
U.S. Pat. No. 4,830,603 to Cirami relates to a cigarette lighter in which a locking mechanism is provided partially under a valve-actuating pushbutton and extends into a compartment appended to but distinct from a fuel compartment. The locking mechanism relocks itself after each depression of the pushbutton. In particular, one end of a stiffly flexible spring steel wire is held firmly in place in the compartment. Another end of the spring steel wire forms a probe extending into a channel provided in the underside of the pushbutton. The spring steel wire, in a locked configuration, prevents depression of the pushbutton by engaging a low ceiling on the underside of the pushbutton. A portion of the spring steel wire in the form of a loop extending outward from the lighter is accessible by an operator and may be suitably moved by the operator thereby causing the probe to move within the channel in the underside of the pushbutton.
U.S. Pat. No. 4,832,596 to Morris, Sr. relates to a cigarette lighter having a stop member slidable mounted thereon for releasably engaging a gas valve actuating lever. In particular, a spring biased stop member is slidable mounted on a top portion of a conventional disposable cigarette lighter. The stop member is biased so as to place one of its ends under the lighter's gas valve actuating lever so as to prevent movement of the lever in a direction which may open the gas valve. The lever may be actuated once the stop member is pushed in a direction opposite to the biasing force of the spring so as to slide the end which is under the lighter's gas valve outward.
U.S. Pat. No. 4,717,335 to Loveless relates to a cigarette lighter in which rotation of a spark-producing wheel is limited. In particular, the spark-producing wheel may be rotated in one direction to deliver a spark toward a nozzle through which gaseous fuel is passed, thereby causing the fuel to ignite and operating the lighter. Rotation of the spark-producing wheel in the other direction may deliver a spark away from the nozzle. The spark-producing wheel has a pin-shaped structure attached thereto which serves to limit the rotation of the wheel to under 360° by contacting the housing structure. Thus, whether a spark indeed is produced depends upon the direction of attempted rotation and the position of the pin-shaped structure relative to the housing structure. In theory, once the lighter is operated and the fuel ignited, and the pin-shaped structure has traversed its entire path of travel, subsequent operation of the lighter is impeded since the pin-shaped structure comes into contact with the housing, preventing a spark from occurring in the vicinity of the fuel nozzle.
U.S. Pat. Nos. 4,028,043 and 4,049,370 each to Neyret relate to presale tamper protection mechanisms which partially surround a spark-producing wheel, fuel nozzle or depressible valve actuation member of a lighter. These presale tamper protection mechanisms are attached to the lighter housing by frangible webs and are removed by a purchaser after sale of the lighter to expose the spark-producing wheel, fuel nozzle and/or depressible valve actuation member. However, such a presale tamper protection mechanism is of limited value once initially removed by a purchaser.
U.S. Pat. Nos. 3,547,566 to Tamarin and 3,899,286 to Lockwood et al. relate to lighters having orientation sensing mechanisms which hinder or prevent actuation of the lighter in an inverted position. Unfortunately, such mechanisms may not provide a sufficient degree of child resistancy to young children who tamper with the lighter since they merely hinder operation in prescribed orientations.
U.S. Pat. No. 4,921,420 to Johnston relates to a disposable lighter having a release means that is physically separated from the conventional lighting means. The lighter may only be operated once the release means is released. The distance separating the release means and the conventional lighting means is intended to be sufficiently large so as to make it difficult for small children to operate the lighter.
U.S. Pat. No. 5,074,781 to Fujita relates to a cigarette lighter having a lock member which must be rotated in a specified direction towards one side of the lighter so as to allow a depressible valve actuator to be depressed and the lighter to operate.
U.S. Pat. No. 5,076,783 to Fremund relates to a lighter having a depressible valve actuator which is coupled to a vertical rod which extends to an opposite end of the lighter where it contacts a locking member. The locking member must first be displaced so as to enable depression of the valve actuator.
U.S. Pat. No. 5,090,893 to Floriot relates to a lighter having a slide member which, when in a first position, prevents depression of a valve actuator. The slide member is slidable movable to a second position in which the valve actuator may be depressed. The slide member is not capable of vertical movement. Additionally, the slide member protrudes from the lighter when in its first position.
Many mechanisms which are designed to render operation of the lighter more difficult by certain users are unnecessarily complicated, present difficulty in their manufacture and/or exhibit a high likelihood of mechanical failure during use. Another disadvantage found in some devices is that the particular construction employed limits the shape and size of the lighter housing due to the requirement that the housing be large enough to accommodate such mechanism(s). Further disadvantages relate to the relative ease with which some mechanisms may be defeated and to the reliability of the mechanisms. For example, some mechanisms may be overridden or removed with relative ease. Additionally, some devices are not equally adaptable for use by both right-handed and left-handed users, and some include inconveniently shaped or positioned levers or knobs which need to be actuated by the user in order to operate the lighter. Furthermore, some of these devices require repositioning of the lighter in an operator's hand after actuation of the mechanism and before the lighter is operated to produce a flame. For example, some lighters include an actuatable mechanism located sufficiently far from a valve actuation means, or on another side of the lighter than the valve actuation means, so as to result in awkward operation of the lighter.
Although it is known to prevent or hinder presale actuation of a depressible valve actuation member or actuation of a lighter in a specified orientation, none of the above-described lighters provides an efficiently manufacturable, relatively small, reliable mechanism for preventing actuation of the depressible valve actuation member and equally adaptable for use by both right-handed and left-handed users.
As will be appreciated, development of a "child-proof" lighter per se is probably not viable. At best, it can be reasonably sought to create a lighter having features which enhance its child-resistant capability, but how "child-resistant" a lighter will be will depend upon many factors and circumstances. Nevertheless, any lighter having features which enhance its child-resistant capability will have limitations with respect to young children, and no such lighter should provide parents or adults with a false sense of security so that they may become less cautious in their handling of the lighter or permit access to the lighter by young children. Further, such lighters should not be made so difficult to light as to cause adults to use alternative forms of lighting, i.e., matches, which are generally considered to be potentially more dangerous.
The invention of, for example, U.S. patent application Ser. No. 07/965,831 is directed toward a reliable flame producing lighter which is selectively actuatable by means of a latch in such a manner as to provide a substantial degree of difficulty for young children--younger than five years--to actuate the lighter and produce a flame, while being user friendly and capable of actuation by adults. The latch prevents depression of the actuator means when a normal amount of pressure is applied by a user's hand. However, if an extreme amount of force is applied, it could cause the latch to break, due to the fact that the latch can not move to release the excess force. The amount of force required to break the latch is not encountered in normal use, but possibly could arise if a user intentionally attempted to disable the latch, for example, by striking it with a hammer.
SUMMARY OF THE INVENTION
This invention relates to a selectively actuatable flame producing lighter having a latch means comprising a latch which is normally in a latched position and which is movable to an unlatched or non-interfering position in which the lighter may be operated. The latch is preferably relatively flush mounted with respect to the lighter housing when in its normally latch position. The latch means further comprises a latch biasing means such as a spring for biasing the latch. Advantageously, the latch may be operated with the same finger a user employs to depress a valve actuation lever, without requiring repositioning of the lighter in a user's hand. The lighter is adapted for use by right-handed as well as left-handed users with the same relative ease.
One particular embodiment of the invention relates to a flame producing lighter which comprises a housing defining a reservoir for containing a combustible gaseous medium such as fuel under pressure; valve means arranged for selective actuation between a normally closed position which prevents exit of the gaseous medium from the reservoir, and an open position which permits exit of gaseous medium from the reservoir through the valve means; means for selectively producing sparks at a location proximate the gaseous medium exit opening of the valve means thereby selectively causing ignition of the gaseous medium; means normally positioned for preventing actuation of the valve means to the open position, the valve actuation prevention means being capable of generally vertical movement in the lighter and being movable out of the normal position into a second position only by application of an external force; spring means for applying a biasing force to the valve actuation prevention means; means for selectively moving the valve actuation prevention means to the second position whereby actuation of the valve means to the open position is permitted thereby selectively permitting exit of the combustible gaseous medium from the valve means and ignition of the gaseous medium by sparks produced by the spark producing means, wherein the valve actuation prevention means automatically returns to the normal position after actuation of the lighter. The lighter preferably includes means to retain the valve actuation prevention means in the second position, thus retaining the lighter in an unlatched configuration. Such retention means may include portions of the housing and/or the spring means and/or portions of the valve actuation prevention means and/or portions of the valve actuator. Additionally, the valve actuation prevention means of the lighter is constrained to move along only a single path from its normal, or latched, position to the second, or unlatched, position.
In this embodiment, the valve means is preferably actuated to the open position by actuator means and the means for preventing actuation of the valve means to the open position comprises interference means for preventing movement of the actuator means, the valve actuation interference means being selectively movable to a position out of interference with the valve actuator means. The valve actuation interference means is normally retained in a valve actuation interference position, the movement thereof to the position out of interference with the valve actuator means is resiliently provided by the spring means. Advantageously, the resilient movement of the valve actuation interference means causes the valve actuation interference means to return to its position beneath the valve actuator once the valve actuator is released, thus preventing the valve nozzle from opening. The spring means preferably comprises a spring which applies a biasing force biasing the valve actuation interference means outward.
The valve actuation interference means may take on a variety of forms such as a latch means, a latch or an interference member and may be movable in a variety of directions. Such movement is generally first in one direction, then in another direction. For example, the latch may be movable first inward and then upward into a notch or cavity in or near the valve actuator until the valve actuator is depressed, whereby fuel exits the valve and the latch moves back under the valve actuator when the valve actuator is released.
The spark producing means of the lighter preferably includes flint material and a rotatable spark-producing wheel which has a toothed surface positioned and arranged to selectively frictionally contact the flint material. Alternatively, the means for selectively producing sparks may be an electric spark-producing means, such as a piezoelectric spark-producing means.
Another embodiment of the invention relates to a flame producing lighter resistant to unauthorized use and normally maintained in a latched configuration comprising a housing; fuel supply means for supplying fuel to be ignited; ignition means for igniting the fuel; valve means for controlling the flow of the fuel; a valve actuator which normally prevents the flow of the fuel when in a first position and is depressible to a second position which permits actuation of the fuel supply means thereby permitting fuel to flow out from the fuel supply means; a latch positioned so as to normally prevent depression of the depressible valve actuator and normally maintain the lighter in the latched configuration; and spring means for applying a biasing force to the latch. Preferably, the latch includes at least a portion normally positioned between at least a portion of the valve actuator and at least a portion of the housing.
In this embodiment, inward movement of the latch enables a tip portion of the latch to become aligned with a cavity in or near the actuator, the cavity being sufficient in size to accommodate the tip portion so as to eventually enable the valve actuator to be depressed.
Such inward movement of the latch is followed by upward movement which causes the aligned tip portion of the latch to enter the cavity and places the lighter in an unlatched configuration in which the valve actuator is capable of being depressed, thereby permitting fuel to flow, the unlatched configuration preferably being resiliently maintained by forces exerted among the latch, the valve actuator, the spring means which biases the latch, and the housing.
Another embodiment of the lighter employs actuator means having a first interfering portion, and means for preventing movement of the actuator means, such prevention means having a finger actuatable portion and a second interfering portion, the first and second interfering portions being normally in alignment with each other thereby preventing movement of the actuator means, the finger actuatable portion being selectively movable so as to move the second interfering portion out of alignment with the first interfering portion, the second interfering portion being normally retained in a valve actuation interference position, the movement thereof to a position out of interference with the valve actuator means being resiliently provided so as to return the second interfering portion to its position in interference with the valve actuator when the valve actuator is released, thus preventing the valve nozzle from opening, and spring means for providing the resilient movement.
In this embodiment, the movement of the finger actuatable portion which causes the second interfering portion to move out of alignment with the first interfering portion is constrained to movement in a single path. The movement of such finger actuatable portion comprises movement first in an inward direction and then movement in an upward direction. Such a lighter preferably includes spring means for retaining the second interfering portion out of alignment with the first interfering portion.
Another embodiment of the invention relates to a fuel cut-off mechanism for use in combination with a lighter which comprises means for normally preventing release of fuel from a fuel supply; means for selectively permitting release of the fuel including a depressible valve actuator which upon depression releases the fuel; a latch which normally interferes with depression of the depressible valve actuator, at least a portion of the latch being normally positioned so as to normally interfere with depression of the valve actuator, the latch being arranged such that inward movement of the latch provides a void sufficient in size to enable depression of the valve actuator wherein fuel is permitted to flow; and spring means for supplying a biasing force to the latch. The latch portion is preferably positioned between at least a portion of the valve actuator and at least a portion of a main body housing of the lighter.
Another embodiment of the invention relates to a flame developing lighter comprising a housing; fuel supply means for supplying fuel to be ignited; ignition means for igniting the fuel; valve means for selectively permitting flow of the fuel; and control means for preventing the combination of production of fuel flow and spark generation so as to prevent production of a flame and for permitting production of fuel flow and spark generation to produce a flame.
The control means of this embodiment preferably includes a valve actuator which normally prevents release of the fuel from the fuel supply means when in a first position and is depressible to a second position which permits release of the fuel, the valve actuator having a cavity formed therein; a latch having an interfering portion which is normally in an interfering position thereby preventing depression of the depressible valve actuator; and a spring means for applying a biasing force to the latch. Inward movement of the latch causes the interfering portion to move toward a non-interfering position and further movement in another direction, subsequent to the inward movement, of the latch into the non-interfering position, provides the lighter in an unlatched configuration in which the valve actuator is capable of being depressed, thereby permitting fuel to flow.
The present invention also relates to an improved lighter of the type having valve means for selectively releasing fuel, means for igniting the fuel, valve actuator means for actuating the valve means so as to release fuel, the valve means including a fuel nozzle which expels fuel when the fuel nozzle is lifted upward by the valve actuator means, wherein the improvement comprises a compensator spring which maintains the fuel nozzle in its downward position when the valve actuator is initially actuated. The compensator spring is preferably positioned between the valve actuator means and a portion of the fuel nozzle so as to urge the fuel nozzle downward. The compensator spring is preferably a metallic coiled spring. The fuel nozzle is preferably normally biased downward by the valve actuator means.
In another embodiment, such lighter includes interference means positioned so as to normally interfere with actuation of the valve actuator means, and the compensator spring means compensates for movement of the valve actuator means when the interference means is normally positioned so as to interfere with the actuation of the valve actuator means.
Operation of the lighter requires a certain amount of dexterity and the application of concentrated forces as well as the application of a plurality of forces in multiple directions and in a specified sequence. Additionally, operation of the lighter requires a certain level of cognitive ability.
Furthermore, the lighter of the present invention is a passive latching lighter. Advantageously, the lighter automatically returns to its latched configuration once the depressed valve actuator is released. Thus, the lighter is maintained in an at-rest or default configuration which is latched thereby preventing the flow of fuel and the production of a flame.
Advantageously, the lighter is adapted for use by right-handed as well as left-handed users with the same relative ease. Furthermore, the user may operate the latch mechanism with the same finger as used to depress the valve actuator without requiring the user to reposition the lighter in the user's hand.
The improved lighter according to the present invention further includes an anti-defeat latch with a modified design to resist forcible disabling of the latch by excessive forces, i.e., about 20 pounds or greater. The inventive design preferably incorporates an angled contact point and an enlarged cavity, so that the lower portion of the latch will move inward, so as to relieve the excessive downward pressure. The angled contact point can be provided at various locations where the latch and the lighter housing or valve actuator come into contact.
The alternative anti-defeat designs disclosed herein achieve the goal of allowing the latch to slide into the cavity of the lighter housing at an angle, instead of having a blunt contact with the valve actuator at the top of the latch and blunt contact with the lighter housing at the bottom of the latch.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features, and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which like elements are labeled similarly. In general, FIGS. 1-6 and 9-15 depict the lighter of the present invention with one embodiment of the valve actuator and latch means, FIGS. 7 and 8 schematically illustrate a piezoelectric embodiment, and FIGS. 16-19 depict anti-defeat embodiments of the lighter and latch which resists forcible disabling of the latch.
FIG. 1 is a partial perspective view of a preferred embodiment of a selectively actuatable lighter of the present invention in a latched configuration;
FIG. 2 is a partial cross-sectional view of the lighter of FIG. 1 depicting the latch in a latched configuration;
FIG. 3 is an exploded view of the valve actuator, latch and latch spring means depicted in FIGS. 1 and 2;
FIG. 4 is a bottom view of the valve actuator depicted in FIG. 3;
FIG. 5 is a side view of the latch depicted in FIG. 3;
FIG. 6 is a side view of the latch spring means depicted in FIG. 3;
FIG. 7 is a schematic diagram depicting a piezoelectric lighter apparatus in which the present invention may be employed and having an optional switch depicted in the open position and a latch means depicted in the latched position to prevent the production of sparks and the flow of fuel;
FIG. 8 is a schematic diagram depicting the piezoelectric lighter of FIG. 7 with the switch depicted in the closed position and the latch means depicted in the unlatched position and depicting a flame;
FIG. 9 is a perspective view of a preferred embodiment of the lighter in an unlatched configuration in which the latch is at its unlatched position thereby permitting depression of the valve actuator so as to permit a valve to open and gas to be released through a fuel nozzle;
FIG. 10 is a perspective view of the lighter of FIG. 9 with the valve actuator in a depressed position and the valve open and depicting a flame;
FIG. 11 is a partial cross-sectional view of the preferred embodiment of the lighter in its latched configuration thereby preventing depression and actuation of the valve actuator;
FIG. 12 is a partial cross-sectional view of the lighter of FIG. 11 in its unlatched configuration and the valve actuator not depressed and the lighter ready for actuation;
FIG. 13 is a partial cross-sectional view of the lighter of FIG. 12 in its partially unlatched configuration and the valve actuator fully depressed so as to permit the flow of fuel;
FIG. 14 is a partial cross-sectional view of the lighter of FIG. 13 in greater detail;
FIG. 15 is a partial cross-sectional view of the lighter of FIG. 13 after the value actuator has been fully depressed and released;
FIG. 16 is a cross-sectional view of a further embodiment of the lighter according to the invention with an anti-defeat latch to resist forcible disabling of the latch;
FIG. 17 is a partial cross-sectional view of the latch shown in FIG. 16 as assembled in the lighter housing; and
FIG. 18 is a partial cross-sectional view of an alternative embodiment of the lighter shown in FIG. 17; and
FIG. 19 is a perspective view of the anti-defeat latch of FIG. 16.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, there is depicted, in a default or at-rest configuration, the lighter 10 of the present invention comprising a main body portion 12, a depressible valve actuator 14, latch 16, and a spark-producing wheel assembly 18 which includes a toothed surface 19. Advantageously, the default configuration is also a latched configuration in which valve actuator 14 cannot be depressed due to the interference presented by latch 16. Depression of valve actuator 14 permits fuel to flow through a fuel nozzle and to be ignited by sparks produced by toothed surface 19 of spark-producing wheel assembly 18 frictionally engaging a flint. Advantageously, unless latch 16 is positioned away from its depicted at-rest or default position and into a non-interfering position, any attempted depression of valve actuator 14 will not result in the flow of fuel and the lighter will be inoperable. The position of latch 16 as shown in FIGS. 1 and 2 may best be characterized as a "default position" under normal conditions.
As will be appreciated, a variety of configurations, shapes and relative positioning exists for the valve actuator and the latch means in which the latch is movable, with respect to the valve actuator, between an interfering or latched position and a non-interfering or unlatched position. The invention will be described in terms of a preferred embodiment in which an illustrative latch normally interferes with depression of the valve actuator when in a latched position, and is movable to an unlatched position in which the valve actuator may be depressed. In this embodiment, the latch is moved from its latched position to its unlatched position along a single path, which is equally suitable for right-handed as well as left-handed users. Such movement is illustratively in an inward direction followed by an upward direction. Alternatively, such movement may be in an inward direction followed by a downward direction, or in an inward direction followed by a cross-wise direction, or in a cross-wise direction followed by a downward direction or in a cross-wise direction followed by an upward direction. Additionally, the reverse of any of these combinations may be employed. For example, the reverse of the inward and then upward movement comprises an upward and then inward movement. Additionally, the latch may be movable along a plurality of paths to a plurality of unlatched positions. As will be appreciated, for ease of understanding, such inward motion of the latch is deemed to include any inward motion or component thereof of any portion of the latch, such upward motion of the latch is deemed to include any upward motion or component thereof of any portion of the latch, and such cross-wise motion of the latch is deemed to include any cross-wise motion or component thereof of any portion of the latch. Additionally, while a first movement may be described as being followed by a separate movement in a different direction, it will be appreciated that such movements or portions thereof can occur simultaneously or overlap each other as in the case of a diagonal movement having inward and upward components. The latch is preferably maintained in its unlatched position after being moved there by a user, and preferably automatically returns to its latched position once a user depresses and releases the valve actuator.
A user typically holds the main body portion of a conventional lighter in his hand, rotates with his thumb the spark-producing wheel in a direction generally toward the depressible surface of the valve actuator to produce a spark, and depresses the valve actuator to allow fuel to pass through the fuel, or valve, nozzle. The spark produced by the wheel ignites the fuel. This is a relatively conventional structure for most lighters, including disposable lighters.
Referring now to FIG. 2, there is depicted a cross-section of the lighter of FIG. 1 in a latched configuration. More particularly, valve actuator 14 is mounted between side wall portions 13 (see FIG. 1) which illustratively comprise extensions of the side walls of body portion 12. Illustratively, valve actuator 14 is pivotally mounted to sidewall portions 13. Valve actuator 14 is attached to hollow fuel nozzle 20 slidably supported within a valve housing 28. Hollow fuel nozzle 20 is held within an opening such as a bore in valve actuator 14 by flange 21, compensator spring means 11 and flange extension 23A. Flange 21 and flange extension 23A each has a sufficient size and is configured so as to prevent slippage of nozzle 20 through the bore in valve actuator 14. Additionally, spring means 11 is maintained as shown in FIG. 2 by flange 23 which is attached to fuel nozzle 20 as is flange 21. A compressed spring means 30 resides beneath valve actuator 14 and causes fuel nozzle 20 to be urged downward into valve housing 28 and body portion 12. In particular, compressed spring 30 causes valve actuator 14 to apply force to spring means 11 which supplies force to flange 23, thereby urging nozzle 20 downward into valve housing 28 and body portion 12 and preventing the flow of fuel through nozzle 20. Additionally, downward movement of value actuator 14 in the vicinity of nozzle 20 is limited by contact between the underside of valve actuator 14 and flange extension 23A. In such an embodiment, valve actuator 14 is employed to lift nozzle 20 by the application of force to flange 21 in order to expel fuel. A valve assembly (not fully shown) is located near the recessed end of nozzle 20 and permits fuel to flow through nozzle 20 only when valve actuator 14 is depressed and nozzle 20 lifted.
As will be appreciated, actuation of valve actuator 14 generally results in upward movement of the valve actuator in the vicinity of nozzle 20. However, in the embodiment depicted in FIG. 2, nozzle 20 remains downward during the initial upward movement of valve actuator 14 in the vicinity of nozzle 20 due to the action of compensator spring 11. More specifically, nozzle 20 only moves upward once the valve actuator in the vicinity of nozzle 20 moves upward a sufficient amount such that a top surface of valve actuator 14 in the vicinity of nozzle 20 contacts flange 21. Advantageously, depression of the valve actuator while the lighter is in a latched configuration, while possibly causing the valve actuator in the vicinity of nozzle 20 to move upward due to, for example, a gap between valve actuator interfering portion 14A and latch interfering portion 16A, will not result in any upward movement of the fuel nozzle. Accordingly, fuel will not be released in the event the valve actuator is depressed while the lighter is in a latched configuration. As will be appreciated, such use of a compensator spring is desirable in lighters which incorporate a gap allowing some depression of a latched valve actuator which would otherwise release fuel due to such depression.
Latch 16 is maintained in its latched configuration as depicted in FIGS. 1 and 2 by latch spring means 33 which is positioned within the lighter such that its movement is limited. Illustratively, spring means 33 is firmly attached to housing 12 at cavity 34. As will be shown, latch 16 may only be moved inward by an external force, i.e., a force applied by a user to latch 16, against the force exerted by latch spring means 33 on latch 16. As will be appreciated by those of ordinary skill in the art, spring 33 may also be formed as a biasing means integral with the latch or the housing, such as by a resilient plastic extension member.
Lighter 10 further comprises a sparking flint 22 mounted within a bore 24 defined by flint and spring housing 29 in main body 12. Flint 22 is urged toward toothed surface 19 of wheel assembly 18 by spring 26. Spark-producing wheel assembly 18, which includes toothed surface 19 which is preferably suitably hardened and against which flint 22 is urged, is mounted for rotation between side wall extension portions 13 in a conventional manner. Toothed surface 19 includes suitable indentations which define teeth such that when spark-producing wheel assembly 18 is rotated toothed surface 19 cuts against flint 22 causing the generation of ignition sparks. Additionally, spark-producing wheel assembly 18 includes suitable indentations 17 which facilitate rotation of spark-producing wheel assembly 18 by an operator's finger.
Main body 12 defines an internal chamber 15 which is filled with a fuel 9 such as butane fuel capable of vaporizing in a conventional manner to produce a gaseous medium which passes through fuel nozzle 20 under the control of a valve. Main body 12 is constructed from any suitable structural material or materials, and is preferably constructed from a plastic material. A shield 32, preferably constructed from metal, is provided and functions as a wind guard around the flame thereby assisting in the ignition of the fuel.
As will be appreciated, main body 12 generally encompasses any part, portion, structure or substructure of the lighter except for the valve actuator and spring, spark-producing wheel assembly, flint and spring, valve assembly, and latch means. Accordingly, what will be described as housing interfering portion 12B is deemed to include any such part, portion, etc.
As depicted in FIG. 1 and 2, a notched opening 25 is provided in body portion 12 to accommodate valve actuator 14 and latch 16 and, in particular, vertical movement of valve actuator 14 and inward as well as vertical movement of latch 16. As will be appreciated, FIGS. 1 and 2 depict the lighter in a latched configuration, i.e., a default configuration. In this latched configuration, an interfering portion 16A of latch 16 is positioned beneath an interfering portion 14A of valve actuator 14 and prevents depression of valve actuator 14, thereby preventing actuation of the valve means and thus the release of fuel.
Referring again to FIG. 2, latch 16 is depicted in its latched configuration in which interfering portion 16A of latch 16 is positioned and configured so as to interfere with and prevent depression of valve actuator 14. More specifically, interfering portion 14A of valve actuator 14 contacts interfering portion 16A of latch 16 upon attempted depression of valve actuator 14, thus preventing the release of fuel from fuel nozzle 20. In its latched configuration, latch 16 is prevented from any downward travel by the contact between interfering portion 16B of latch 16 and interfering portion 12B of main body 12. Alternatively, any such downward travel of valve actuator 14 may be prevented by another portion of latch 16 contacting another portion of body 12 or another portion of latch 16 contacting another portion of valve actuator 14. As will be discussed in conjunction with FIGS. 4 and 5, the underside of valve actuator 14 is provided with a notch or cavity 27 suitably shaped for receiving a portion of latch 16 including a tip portion 16C which in turn includes interfering portion 16A.
Referring now to FIG. 3, there is depicted valve actuator 14, latch 16 and latch spring means 33 in greater detail. Valve actuator 14 comprises a finger depressible surface 31, extensions 36, an opening such as a bore 38, and cavity 27. Preferably, cavity 27 is shaped so as to accommodate tip portion 16C of latch 16, including interfering portion 16A. A user desiring to actuate the lighter must first force tip portion 16C into or near cavity 27 by initially applying a component F1 of force to a finger actuatable portion 16D of latch 16 so as to force tip portion 16C inward and into alignment with cavity 27, and then applying a component F2 of force to finger actuatable portion 16D so as to force tip portion 16C upward into cavity 27. The user may then depress finger depressible surface 31.
Extensions 36 are provided to matingly engage with bores in side wall portions 13 of body portion 12 to provide pivotal movement of the valve actuator about extensions 36. Bore 38 is adapted for receiving and grasping a portion of fuel nozzle 20 between flanges 21 and 23. In the latched or closed configuration depicted in FIGS. 1 and 2, an upper surface of interfering portion 16A of latch 16 abuts a lower surface of interfering portion 14A of valve actuator 14, and a lower surface of interfering portion 16B of latch 16 abuts an upper surface of interfering portion 12B of body 12, thereby preventing depression of valve actuator 14. Alternatively, a small gap may be provided between the upper surface of interfering portion 16A of latch 16 and a lower surface of interfering portion 14A of valve actuator 14, or between the lower surface of interfering portion 16B and the upper surface of interfering portion 12B.
Referring now to FIGS. 3-6, and in particular to FIG. 5, latch 16 is preferably provided with a portion 16E for contact with portion 33A of latch spring 33. More specifically, portion 33A of latch spring 33 applies force to portion 16E of latch 16 so as to normally maintain the lighter in a latched configuration, and also to facilitate retention of the lighter in an unlatched configuration. Alternatively, portion 33A may normally be positioned a slight distance away from latch 16 such that spring 33 is not normally under loading. Additionally, the size, shape, and configuration of latch 16 facilitates stabilization of latch 16 within the lighter and assures proper positioning and retention of latch 16 in notched opening 25 especially when the latch is moved. Finger actuatable portion 16D of latch 16 is employed by a user to move the latch and, in particular, to move tip portion 16C inward and then upward so as to enter cavity 27 of actuator 14.
Advantageously, such a configuration facilitates movement of latch 16 between its latched position and its unlatched position. Additionally, such a configuration facilitates retention of the lighter and, in particular, latch 16, in an unlatched or non-interfering position or configuration once the latch is placed in such an unlatched position or configuration and until valve actuator 14 is depressed and released.
It is desirable that the material from which latch 16 is constructed is relatively inflexible material which will not deform under normal use. Latch 16 is preferably constructed from any sufficiently rigid metal or plastic, although a wide variety of other suitable materials having a sufficient degree of rigidity may be employed.
Referring now to FIG. 4, there is depicted a view of the underside of valve actuator 14 of FIG. 3. A portion 35 of valve actuator 14 is adapted to receive spring 30 as depicted in FIG. 2 and may take on a variety of forms such as a protruding member or, alternatively, an indentation or bore partially into valve actuator 14. The fuel nozzle is illustratively maintained in bore 38 by fuel nozzle flanges 21 and 23 and spring means 11 (FIG. 2) which have a diameter greater than that of a corresponding portion of bore 38. Cavity 27 is formed in the underside of valve actuator 14 as depicted in FIG. 4, and may take on any shape suitable to properly receive tip portion 16C of latch 16.
Valve actuator 14 is constructed from material having sufficient dimensional stability and rigidity to continuously over the life of the lighter assure proper relative positioning between interfering portion 14A of valve actuator 14 and interfering portion 16A of latch 16. Actuator 14 is preferably constructed from zinc or glass-filled polyetherimide. Other illustrative materials from which valve actuator 14 may be constructed are aluminum and other glass filled polymers such as polyethersulfone or the like, as well as combinations of these materials.
Referring now to FIG. 6, there is depicted a side view of latch spring means 33 in which portion 33A contacts portion 16E of latch 16 (FIGS. 2, 3, 5). Spring means 33 is mounted in the lighter housing and is dimensioned and structured to slidably engage portion 16E on latch 16. As will be appreciated, a variety of configurations, shapes and relative positioning exist for spring means 33 in which the spring means normally maintains the lighter in a latched configuration and is resiliently movable to configure the lighter in an unlatched configuration. For example, spring means 33 may be integrally formed with or permanently attached to latch 16. It is desirable that the material from which spring means 33 is constructed is relatively rigid material which is sufficiently resilient to permit movement of latch 16 from its latched position to its unlatched position. Spring means 33 is preferably constructed from any sufficiently resilient elastomer or metal, although a wide variety of other suitable materials having a sufficient degree of elastic memory and a suitable modulus of rigidity may be employed.
FIG. 7 schematically depicts a piezoelectric type lighter in which the present invention may be employed. The piezoelectric lighter comprises hammer and fuel release means 64, spark providing means 66, optional electrical cut-off switch 68, latch means 70 and valve means 71. The piezoelectric lighter operates in a conventional manner except for depression of hammer means 64 which is prevented by inclusion of latch means 70 operative in accordance with the present invention. Illustratively, such latch means comprises a latch and a latch spring means which prevent the production of sparks. In particular, latch means 70 may prevent the production of sparks by electrically and/or mechanically isolating an energy source from the spark producing means. Alternatively, the latch means may be arranged to selectively prevent only the flow of fuel or it may be arranged to selectively prevent both the production of sparks and the flow of fuel. As depicted in FIG. 7, the lighter is in a latched configuration since latch means 70 is positioned so as to prevent actuation of hammer means 64. Additionally, optional switch 68 is depicted in an open, or off, position.
FIG. 8 schematically depicts the piezoelectric type lighter of FIG. 7 in an unlatched configuration. In particular, latch means 70 is positioned so as to enable actuation of hammer means 64. Additionally, switch 68 is depicted in a closed, or on, position. As will be appreciated, incorporation of optional switch 68 requires that it be closed and that latch means 70 be unlatched in order for fuel to be ignited.
In operation of the present invention, and as depicted in FIGS. 1, 9 and 10, a user must first move latch 16 in an inward direction (FIG. 9) so as to sufficiently displace interfering portion 16A of latch 16 out of interference with interfering portion 14A of actuator 14, and at least partially align tip portion 16C of latch 16 with cavity 27 of actuator 14 so as to ultimately permit depression of valve actuator 14. However, in order to facilitate retention of latch 16 in a non-interfering position, latch 16 is then displaced in an upward direction such that tip portion 16C of latch 16 engages a portion of valve actuator 16 defined by cavity 27 (see also FIGS. 2 and 3). Such an unlatched configuration is depicted in FIG. 9. Depression of valve actuator 14 at this point and suitable rotation of the spark-producing wheel assembly 18 will cause the lighter to operate, and will also cause latch 16 to travel downward as indicated in FIG. 10. In particular, the sparks thus produced will ignite the gaseous fuel which is permitted to be expelled from the fuel nozzle when valve actuator 14 lifts the nozzle thereby actuating the valve. The lifting action of valve actuator 14 in a vicinity near the nozzle releases fuel from the fuel chamber thereby permitting the flow of fuel as a gaseous medium through the nozzle and the subsequent burning of such fuel.
Thus, the presently preferred embodiment of the invention may be placed in an unlatched configuration from its default latched configuration by sufficiently displacing interfering portion 16A relative to interfering portion 14A. This may be accomplished by moving tip portion 16C into engagement or alignment with a portion of valve actuator 14 defined by cavity 27. Advantageously, the path defined by such movement is the same for right-handed and left-handed users, and each of such users may unlatch the lighter with the same relative ease. Thus, this embodiment of the lighter of the present invention enables every user, whether right-handed or left-handed, to actuate the lighter by suitably urging the latch out of interference with the valve actuator.
FIGS. 11-15 depict the sequence of operations required for the unlatching of the lighter by positioning tip portion 16C in cavity 27 of actuator 14. In particular, FIG. 11 depicts latch 16 and valve actuator 14 in the default or latched configuration. In this configuration, depression of valve actuator 14 by finger pressure on surface 31 is prevented by the contact between interfering portion 14A of valve actuator 14 and interfering portion 16A of latch 16. As depicted in FIG. 11, interfering portion 16A is positioned directly beneath interfering portion 14A of valve actuator 14 and latch 16 is prevented from any further downward movement since interfering portion 16B of latch 16 abuts interfering portion 12B of body 12. Additionally, FIG. 11 depicts a small gap separating interfering portions 16A and 14A. For ease of illustration, the gap between portions 14A and 16A in the figures is not necessarily drawn to scale. Additionally, such a gap is not necessary for proper operation of the invention.
FIG. 12 depicts latch 16 and valve actuator 14 in an unlatched configuration ready for depression of valve actuator 14. Tip portion 16C of latch 16 has been moved inward and upward as indicated by the arrows into engagement with cavity 27 of valve actuator 14. Advantageously, due to, inter alia, the loading which latch 16 is under when tip portion 16C engages part of actuator 14 defined by cavity 27, removal of holding pressure from finger actuatable portion 16D once tip portion 16C has been engaged with, i.e., inserted into, cavity 27 will not result in tip portion 16C or finger actuatable portion 16D slipping toward their respective latched positions but will maintain the lighter in the unlatched configuration depicted in FIG. 12, until valve actuator 14 is depressed. In other words, the lighter may be readied for actuation and flame production by applying suitable force to finger actuatable portion 16D to first move portion 16D in an inward direction and then in an upward direction so as to place tip portion 16C into engagement with cavity 27 of valve actuator 14.
Application of finger pressure to the finger depressible surface of valve actuator 14 as depicted in FIG. 12 will yield the configuration depicted in FIG. 13 in which valve actuator 14 has been depressed thereby permitting fuel to flow through the valve and the fuel nozzle (not shown). In particular, depression of valve actuator 14 urges latch 16 downward toward its partially latched position. Additionally, and as more clearly depicted in FIG. 14, such depression of valve actuator 14 will cause compression of spring 30 and urging of fuel nozzle 20 upward and partially out of valve housing 28 and body portion 12. Such lifting of fuel nozzle 20 upward will permit fuel to flow from chamber 15 through the valve and out of nozzle 20 whereupon it will have been ignited by sparks produced by flint 22 and toothed surface 19 of spark-producing assembly wheel 18. Such fuel will continue to flow and burn as long as sufficient pressure is maintained on valve actuator 14.
As depicted in FIG, 15, once pressure is removed from valve actuator 14, the valve actuator will move upward due to the biasing force provided by spring 30, and the flame will be extinguished. Advantageously, as valve actuator 14 moves upward, latch 16 remains in the down position since frictional forces between latch 16 and actuator 14 are less than the forces required to lift the latch and overcome, for example, forces between latch 16 and portions of body 12 and forces between latch 16 and latch spring means 33. Once valve actuator 14 moves upward a sufficient amount, tip portion 16C and finger actuatable portion 16D move in an outward direction toward their at-rest or default position.
FIGS. 16-19 depict a further alternative embodiment including an anti-defeat design which resists forcible-disabling of the child-resistant nature of the latch. According to this embodiment, the lighter has an angled or curved portion provided at one or more of the contact points between the latch and the housing or actuator. At least three possible contact points are shown in FIGS. 17 and 18 at 121, 123 and 140. Others may be identified by persons skilled in the art. The angled portion is more preferably provided on the latch itself for ease of manufacture. In one preferred embodiment, as shown in FIG. 16, anti-defeat latch 120 is provided with angled portion 122, located at the contact point 121 with the lighter housing, located on the lower end of the latch. In use, when a user attempts to disable the latch by applying extreme pressure, the latch will slide along the angled portion 122 into the enlarged cavity 124 of the lighter housing. Cavity 124 is of sufficient size to easily accommodate the lower end of latch 120.
Angled portion 122 is generally formed at an angle (A) between about 10° to 30° and preferably at about 20°. It is not necessary that a precise angle be employed as long as the effect is as described herein. The angled portion preferably should not occupy the entire contact surface, as is shown in FIG. 16. By way of non-limiting example, if the depth of the entire contact surface is about 0.75 mm, then preferably the depth (D) of the non-angled portion is from about 0.25 mm to 0.50 mm, and more preferably about 0.40 mm. Based on the disclosure contained herein, persons of ordinary skill can size the latch as required for a particular lighter. As shown in FIG. 17, the lighter housing is also preferably modified to provide a larger cavity 124 within the housing, as compared to the embodiment of FIG. 2, so that latch 120 can easily slip inside the housing when excessive force is applied. Once the pressure is released, the latch 120 will return to its normal position, preventing actuation of the lighter until the latch is properly moved inward and upward by a user.
FIG. 18 illustrates an alternative preferred embodiment in which the angled portion is located on the lighter housing itself. In this embodiment housing 130 has an angled portion 132, located at lower contact point 123 with latch 16. Contact point 123 on the housing is formed with substantially the same, but inverted, configuration as contact point 121, shown in FIGS. 16 and 17. The design illustrated in FIG. 18 will achieve the same effect as providing the angled portion on the latch, allowing the latch to slip inside the cavity created by the lighter housing to relieve the pressure created by extreme downward force being applied. Lighter housing 130 can be used as illustrated with latch 16 or with the alternative angled latch 120 of FIGS. 17 and 18.
Similarly, an angled portion can be provided on the latch, housing, or actuator at other contact points. For example, at contact point 140 either the latch or valve actuator could be provided with an angled portion as described herein that would allow the latch to slip into the cavity of the lighter housing.
FIG. 19 is a perspective view of the anti-defeat latch 120 of the preferred embodiment shown in FIG. 16, which illustrates side flanges 144 and angled portion 122. Side flanges 144 assist in guiding the latch in the housing.
While it is apparent that the invention herein disclosed is well-calculated to fulfill the objects above stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.
More specifically, the latch means and lighter disclosed and claimed herein are not limited to use in disposable lighters. Moreover, the present invention is not limited to a latch means in which a latch is moved first in an inward direction then in an upward direction ninety degrees from the inward direction, then in an inward direction and then in an upward direction in order to align an interfering portion of the latch with a cavity in the valve actuator so as to enable depression of the actuator. For example, any of a wide variety of latches or actions may be employed, such as latches having right-left, front-rear, over and down, in and over, over and up, etc. type actions, or any of such actions coupled with an inward movement. Similarly, the latch may be positioned at other locations within the lighter body so as to prevent depression of the valve actuator by interfering with other portions of the valve actuator. For example, the latch may be positioned at a side of the lighter as opposed to the rear of the lighter depicted in the figures.
|
A selectively actuatable lighter is disclosed which includes a body defining reservoir for containing a combustible gaseous medium such as butane, and having a valve arranged to be selectively actuated between a normally closed position and an open position which permits the exit of the gaseous medium. Such lighter can selectively produce sparks at a location proximate to the gaseous medium exit to ignite the gaseous medium. Such lighter embodies a resiliently releasable latch means which normally prevents actuation of a valve actuator to the open position thereby preventing actuation of the valve. The latch means includes a latch which is selectively movable to a position out of interference with the valve actuator, so that the gaseous medium may be released and ignited by the sparks. The latch means is resiliently structured and mounted such that once the valve actuator is depressed and released, the latch returns to its closed or latched position to prevent actuation of the valve to the open position. The lighter according to the present invention also resists forcible disabling of the latch by providing an angled portion at one of the contact points of the latch with the housing (or of the latch with the valve actuator), so that the latch will displace to a secondary position. This displacement absorbs the excessive force applied without deformation or damage to the latching mechanism, allowing for the latch to return to the normal closed or latched position after release of the excessive force.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the filing date of U.S. Provisional Application No. 61/760,167 filed Feb. 4, 2013 and entitled “METHOD AND APPARATUS FOR DETECTING INCONSISTENT CONTROL INFORMATION IN LTE DOWNLINK CONTROL CHANNEL,” the entire disclosure of which is hereby expressly incorporated by reference herein.
BACKGROUND OF THE INVENTION
The present invention relates generally to wireless communication systems and, more particularly, to mobile station receiver architectures and methods that employ decoding multiple hypotheses such as in case of 3rd Generation Partnership Project (“3GPP”) Long Term Evolution (“LTE”) wireless communication system.
As shown in FIG. 1 , a wireless communication system 10 comprises elements such as a client terminal or mobile station 12 and base stations 14 . Other network devices which may be employed, such as a mobile switching center, are not shown. As illustrated, the communication path from the base station (“BS”) to the client terminal direction is referred to herein as the downlink (“DL”) and the communication path from the client terminal to the base station direction is referred to herein as the uplink (“UL”). In some wireless communication systems the client terminal or mobile station (“MS”) communicates with the BS in both DL and UL directions. For instance, this is the case in cellular telephone systems. In other wireless communication systems the client terminal communicates with the base stations in only one direction, usually the DL. This may occur in applications such as paging.
Most wireless communication systems have an overhead in terms of managing and controlling the wireless link between the network and the client terminal. A number of beacon signals may need to be transmitted by the base station that enables the client terminal to detect the base station and synchronize to it. For example, in LTE wireless communication system the Primary Synchronization Signal (“PSS”), the Secondary Synchronization Signal (“SSS”), and Physical Broadcast Channel (“PBCH”) are used to enable the client terminal to detect and synchronize to the base station. Even after the client terminal detects and synchronizes with the base station, it needs additional information about the detailed structure of the channel and various parameters required for communication with the base station in both DL and UL. This information is generally referred to as “System Information.” Depending on the particular wireless communication system, the base station may transmit the System Information in one or more smaller independent units of information.
Even after the client terminal has detected the base station, synchronized to it and had decoded the System Information, it does not have any specific resources allocated to it for communication. For this purpose, it has to first transmit a signal in UL to request resources in DL, UL, or both. In many wireless communication systems, multiple client terminals use the same resources for communication. The base station manages the overall allocation of the resources to the multiple client terminals contending for the same shared channel. While making resource allocation decisions, the base station considers a number of factors such as the required bit rate, latency, quality of service required, bit error rate, channel conditions, the loading of the cell in terms of number of active users, etc. Furthermore, these factors vary continuously and the base station adapts its decisions dynamically.
Conventional wireless communication systems are primarily used for voice calls and text messaging. The resource allocation for a voice can be done once and then it does not change for a relatively long time. For example, average phone call duration may be in the order of minutes. Similarly, text messaging may be much less frequent. The latency in allocation of resources for setting up a voice call is usually in the order of several seconds. This latency is generally acceptable to the users since it is a onetime latency during the call setup. After the call is setup the allocated channel resources are dedicated to the user for the duration of the call. Another part of the resource allocation is the overhead incurred in the process of allocating the resources. For example, number and size of control messages required to establish a phone call may be significant. However, the call setup overhead due to control message is a small percentage of the duration of the call since the overhead is incurred only once per call.
Over the years, the use of the internet has increased over the wireless communication networks. Normally the traffic pattern of internet usage is very bursty, e.g., the request for resources comes very frequently but each request is only for a short duration of time. Under such traffic conditions the latency of several seconds in the conventional wireless communication systems may not be acceptable. Therefore, one requirement is to have a resource allocation method that can allocate resources with low latency. Another requirement is that the allocation of the resources must incur low overhead since the allocation, release and reallocation of resources occur much more frequently.
The LTE wireless communication system is designed for low latency and high throughput applications. Examples of such applications include the web browsing, mobile online gaming, video calls, media streaming, etc. Supporting such applications requires the allocation of resources in a dynamic manner. This is in contrast with respect to the previous generation wireless communication systems that are designed for allocations that do not change for tens of seconds and even minutes and hours. In LTE wireless communication system, the resource allocation may change once every millisecond.
The potential penalty for such dynamic resource allocation may be that the overhead for allocating the resources is incurred every millisecond. To keep the overhead of resource allocation low while keeping the resource allocation dynamic and the latency low, the LTE wireless communication system employs several techniques.
The LTE wireless communication system employs Orthogonal Frequency Division Multiple Access (“OFDMA”) technology in the DL air interface. The basics of OFDMA are described in “4G LTE/LTE-Advanced for Mobile Broadband” by Dahlman, Erik, et al., copyright 2011 and published by Academic Press, MA, the entire disclosure of which is hereby expressly incorporated by reference herein. The high level structure of the LTE DL air interface, as described in 3GPP TS 36.211: “Evolved Universal Terrestrial Radio Access (“E-UTRA”); Physical channels and modulation,” is shown in FIG. 2 . The air interface consists of series of frames of 10 ms each and each frame consists of 10 subframes with 1 ms per subframe. As shown in FIG. 3 each subframe in turn consists of 12 or 14 OFDM symbols depending on the length of Cyclic Prefix (“CP”) used. The FIG. 3 shows the structure for Normal CP with 14 OFDM symbols per subframe for the case of 10 MHz channel bandwidth with 50 Resource Blocks (“RBs”). FIG. 3A focuses on certain subframes from FIG. 3 for clarity purposes.
The first few OFDM symbols of each subframe are used for control channel purposes and it is called Control Region as shown in FIG. 3 . A control channel, called Physical Downlink Control Channel (“PDCCH”) is designed for the purpose of dynamic resource allocation. The payload data describing the resource allocation information that is transmitted using PDCCH is called Downlink Control Information (“DCI”). The DCI describes the allocation of the resources in the remaining portion of the subframe call Data region.
The PDCCH is transmitted within the control region of each subframe. The number of OFDM symbols used for the control region may vary from one subframe to another. The actual number of OFDM symbols used for a subframe is given by another control channel called Physical Control Format Indicator Chanel (“PCFICH”). The PCFICH is always transmitted in the first OFDM symbol of each subframe. The number of control symbols in each subframe is at least one OFDM symbol. Each PDCCH allocates resources for one client terminal in either DL or UL. Therefore, there may be multiple PDCCHs in the control region.
In LTE wireless communication systems the base station is referred as Enhanced Node B (“eNB”). One of the requirements from eNB in LTE wireless communication systems is the flexibility in addressing (sending resource allocation to) a particular client terminal through the PDCCH. This flexibility in turn requires the client terminal to search all the possible PDCCH candidates within different parts of the control region in each subframe, as shown in FIG. 3 , for possible resource allocation to it. In any given subframe, there may or may not be any resource allocation for a particular client terminal. The allocation for DL and UL are provided separately since the internet traffic pattern in general may be asymmetric. Therefore, in a single subframe there may be zero, one or two PDCCHs transmitted by the base station to a particular client terminal. In some special conditions, there may be more than two PDCCHs transmitted to a particular client terminal in a single subframe.
To keep the allocation overhead low, the PDCCH may be transmitted with different level of Forward Error Correction (“FEC”). This is referred to as Aggregation Level (“AL”) in LTE wireless communication systems. Depending on the expected signal conditions of the client terminal to which the PDCCH is transmitted, the base station may dynamically use a different AL. However, the client terminal may not be a priori aware of the AL used by the base station. The AL used for different client terminals may be different. A Control Channel Elements (“CCE”) consists of 72 transmission bits (coded bits after FEC) and it is a basic allocation unit for PDCCH transmission within a subframe. Each aggregation level uses one or more CCEs within the control region of a subframe. There are total of four different aggregation levels used in LTE wireless communication systems as shown in FIG. 4 , employing 1, 2, 4, and 8 CCEs with 72, 144, 288 and 576 transmission bits respectively.
In LTE wireless communication systems different formats for the DCI messages are used for handling different allocation requirements. For example, DL allocation and UL allocation messages may have different types of information. In LTE wireless communication systems different multi-antenna transmission modes are used. Depending on the particular transmission mode used the type and length of the DCI messages may vary. At any given time, a UE (user equipment) is required to decode DCI messages of at most two possible different lengths.
Considering all the above factors, the PDCCH AL, the length of the DCI message and all the possible PDCCHs that may be transmitted by the base station, the client terminal has to perform PDCCH decoding with a number of different combinations. This is often referred to as blind PDCCH decoding.
In LTE wireless communication systems different UEs are identified using various identities known Radio Network Temporary Identifier (“RNTI”) which is unique within a cell. There are some RNTIs that are broadcast type which address all the UEs in a cell whereas there are other RNTIs that address a particular client terminal. Each client terminal is assigned a unique RNTI within the cell when it first camps on a cell. In a PDCCH, a particular client terminal is addressed by the eNB by using the RNTI for that client terminal. However, in order to keep the overhead low, the RNTI is not explicitly added to the DCI payload.
A concept of search space is used in LTE wireless communication systems to reduce the number of PDCCH candidates that a client terminal must decode in each subframe. The search space is divided into two parts: Common Search Space (“CSS”) and UE Specific Search Space (“UESSS”). The PDCCHs with broadcast RNTIs may be transmitted only in the CSS whereas the PDCCH with UE specific RNTI may be transmitted in either the CSS or UESSS. The CSS is common to all the UEs that are camped on a cell. The UESSS is derived from the UE specific RNTI. Within the control region of each subframe, the UE only searches within the CSS and its UESSS for possible PDCCHs being transmitted to it. The specific CCEs to which a particular PDCCH is mapped to is a function of the search space, aggregation level and the RNTI of the UE in case of UESSS. For the CSS, the PDCCHs are always mapped to the first 16 CCEs as shown in FIG. 5 . The mapping of the UESSS PDCCH candidates depends on its RNTI and an example of that is shown in FIG. 6 . The summary of the PDCCH candidates a UE is required search under normal operation is summarized in the table contained in FIG. 7 . Considering all the PDCCH candidates and two different DCI lengths, total of 44 blind PDCCH decoding attempts may be required in each subframe.
In addition to the FEC, error detection is used for PDCCH to enable the client terminal to ensure whether the PDCCH decoding is successful or not. The error detection is performed using a 16-bit Cyclic Redundancy Check (“CRC”). The RNTI of the client terminal to which the PDCCH is addressed is XOR-ed with the computed CRC over the DCI payload as shown in FIG. 8 . The intended RNTI may be a broadcast RNTI or client terminal specific RNTI.
During the course of blind PDCCH decoding the client terminal must match the locally computed CRC against one of the broadcast RNTIs or its assigned unique RNTIs. Only when the XOR-ed CRC match, a PDCCH decoding is considered successful.
During blind PDCCH decoding in the client terminal, the input to the PDCCH decoder may be from an actual signal transmitted by eNB or from some random values from parts of the downlink signal. This may be because the eNB may not be transmitting any information at all or may be transmitting information intended for other client terminals. Only few (typically two or three) of the 44 blind decoding attempts may have a useful signal transmitted by eNB intended for the particular client terminal as input to the PDCCH decoder. The probability that a random 16-bit pattern matches the true CRC for the payload portion of the data is 1/2 16 . When a computed CRC on the received PDCCH matches the received CRC when there was no PDCCH transmitted, it is defined as a false PDCCH decoding. Considering that there are 44 blind decoding attempts made by the client terminal per subframe, the probability of getting a false PDCCH decoding per subframe is 44*(1/2 16 ). Furthermore, the PDCCH CRC is checked in conjunction multiple RNTIs that may be used by the client terminal. Assuming that on average two identifiers may be used by the client terminal at any given time, the probability of false PDCCH detection may be increased further by a factor of two, i.e., 2*44*(1/2 16 ). Since there are 1000 subframes in one second, the probability of getting one false PDCCH per second is 1000*2*44*(1/2 16 ). This translates to about a 134% chance of one false PDCCH decoding per second. This means that at least one false PDCCH is likely to occur every second. When a UE is required to decode PDCCH with additional RNTIs such as SI-RNTI or SPS-RNTI, the probability of false PDCCH detection is further increased.
The false PDCCH decoding may lead to false DCI which in turn leads to false resource allocation in the client terminal. Such false PDCCH detection may cause two types of problems. If the false PDCCH detection is related to downlink resource allocation then it may cause the client terminal to receive the downlink data that does not actually contain any information for that particular client terminal. This results in unnecessary power consumption in the client terminal. Furthermore, if there was another allocation in the same subframe that was actually intended for the client terminal there may be conflict in the allocated resources. This may cause the client terminal to behave in an unpredictable manner and could result in the client terminal not receiving the data that was intended for it. For the uplink direction, the false detection of the PDCCH may result in the client terminal transmitting on resources that are not granted to it. This may cause interference to other client terminal which may be allocated those particular resources. This may lead to unnecessary power consumption on all the client terminals that may be transmitting on those particular resources. Furthermore, the bandwidth is wasted in both the downlink and the uplink of the wireless communication system.
The LTE wireless communication system uses Hybrid Automatic Repeat Request (“HARQ”). False PDCCH detection can also cause the HARQ Finite State Machine (“FSM”) running at the client terminal and at the eNB to be out of sync. For each downlink resource allocation there is a corresponding HARQ acknowledgement in the uplink. The location of uplink acknowledgement is based on the start position of the PDCCH blind decoding candidate. The false PDCCH decoding then in turn leads to transmission of HARQ acknowledgment (positive or negative) in the uplink direction at the wrong location in uplink resources and possibly interfering with other client terminals that may be sending HARQ acknowledgements. The false PDCCH decoding may lead to a series of problems that compound over a period of few subframes.
Multiple successful PDCCH detection may occur when single set of PDCCH data is processed by the receiver in the client terminal assuming different message sizes and coding rates and AL. For example, it may be possible to successfully decode a message of the same size with different AL assumption. This leads to multiple successful decoding of a single PDCCH for a given client terminal. This is referred herein as duplicate PDCCH detection.
SUMMARY OF THE INVENTION
In accordance with aspects of the invention, a computer-implemented method of checking for false downlink control information in a wireless communication system is provided. The method comprises selecting one or more radio network temporary identifiers (RNTI) for which a physical downlink control channel (PDCCH) needs to be configured for a present operating mode of a client device; for every subframe, configuring, by one or more processors, the one or more selected RNTI into a PDCCH decoder; for every subframe, configuring a number of PDCCHs to be received for each configured RNTI to the PDCCH decoder; and performing PDCCH decoding using the PDCCH decoder.
In one example, the method further comprises limiting a maximum number of blind PDCCH decoding attempts based on an expected maximum number of successful PDCCHs in any given subframe. In another example, the method further comprises, after performing the PDCCH decoding, determining whether a cyclic redundancy check (CRC) of the decoded PDCCH matches any of the configured RNTI. Here, when the PDCCH CRC does not match with any of the configured RNTI, the method may further comprise determining whether to continue further PDCCH decoding based on whether a maximum number of PDCCH decoding attempts has been completed. Alternatively, when the PDCCH CRC matches with one of the configured RNTI, the method may further comprise incrementing the number of PDCCH decoded for the matching RNTI. In this case, the method may further comprises determining whether the configured number of PDCCHs for a given RNTI is decoded or not; when the configured number of PDCCHs for a given RNTI is not decoded yet, determining whether the maximum number of PDCCH decoding attempts has been completed; and when the configured number of PDCCHs for a given RNTI is decoded, removing from the list of configured RNTIs for the current subframe the RNTI for which the configured number of PDCCHs are decoded.
According to other aspects, a processing system configured to check for false downlink control information in a wireless communication network is provided. The system comprises memory configured to store information associated with one or more radio network temporary identifiers (RNTI) and one or more physical downlink control channels (PDCCH), and one or more processors. The processors are configured to select one or more RNTI for which a PDCCH needs to be configured for a present operating mode of a client device; for every subframe, configure the one or more selected RNTI into a PDCCH decoder; for every subframe, configure a number of PDCCHs to be received for each configured RNTI to the PDCCH decoder; and perform PDCCH decoding using the PDCCH decoder.
In one example, the one or more processors are further configured to: determine whether a cyclic redundancy check (CRC) of the decoded PDCCH matches any of the configured RNTI; when the PDCCH CRC does not match with any of the configured RNTI, determine whether to continue further PDCCH decoding based on whether a maximum number of PDCCH decoding attempts has been completed; and when the PDCCH CRC matches with one of the configured RNTI, incrementing the number of PDCCH decoded for the matching RNTI. In this case, the one or more processors may be further configured to: determine whether the configured number of PDCCHs for a given RNTI is decoded or not; when the configured number of PDCCHs for a given RNTI is not decoded yet, determine whether the maximum number of PDCCH decoding attempts has been completed; and when the configured number of PDCCHs for a given RNTI is decoded, remove from the list of configured RNTIs for the current subframe the RNTI for which the configured number of PDCCHs are decoded.
According to further aspects, a wireless communication device is configured to check for false downlink control information in a wireless communication network. The device comprises a transceiver, memory, a PDCCH decoder, and one or more processors. The transceiver is configured to receive downlink control information; memory configured to store information associated with one or more radio network temporary identifiers (RNTI) and one or more physical downlink control channels. The PDCCH decoder is configured to perform PDCCH decoding. And the one or more processors are operatively coupled to the transceiver, the memory and the PDCCH decoder. The one or more processors are configured to: select one or more RNTI for which a PDCCH needs to be configured for a present operating mode of a client device; for every subframe, configure the one or more selected RNTI into the PDCCH decoder; for every subframe, configure a number of PDCCHs to be received for each configured RNTI to the PDCCH decoder; and cause the PDCCH decoder to perform the PDCCH decoding.
In accordance with other aspects, a computer-implemented method of detecting false downlink control information in a wireless communication system is provided. The method comprises: determining, by one or more processors, whether a physical downlink control channel (PDCCH) candidate has been successfully decoded at a first aggregation level of a particular tree structure; when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skipping PDCCH candidates at a second, higher, aggregation level within the particular tree structure; performing, by the one or more processors, duplicate PDCCH detection; when the detection determines that the PDCCH candidate is not a duplicate, extracting a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and determining whether the HARQ process identity is within an expected limit.
In one example, when the detection determines that the PDCCH candidate is a duplicate, the method declares the PDCCH candidate a duplicate and discarding it. In another example, performing the duplicate PDCCH detection includes checking whether a message is identical to another successfully decoded message of the same length. In a further example, performing the duplicate PDCCH detection includes checking whether a cyclic redundancy check (CRC) of a decoded PDCCH message is identical to the CRC of a previously decoded PDCCH message.
In yet another example, the method further comprises: extracting new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message; determining whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and when it is determined that the extracted NDI field has toggled, checking the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI. Here, the method may further comprise: when it is determined that the extracted NDI field has not toggled, determining whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identifying the received DCI as the true DCI.
In accordance with further aspects of the invention, a processing system is configured to detect false downlink control information in a wireless communication network. The system comprises: memory configured to store information associated one or more physical downlink control channels (PDCCH) and one or more processors coupled to the memory. The one or more processors are configured to: determine whether a PDCCH candidate has been successfully decoded at a first aggregation level of a particular tree structure; when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skip PDCCH candidates at a second, higher, aggregation level within the particular tree structure; perform duplicate PDCCH detection; when the detection determines that the PDCCH candidate is not a duplicate, extract a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and determine whether the HARQ process identity is within an expected limit.
In one example the one or more processors are further configured to: extract new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message; determine whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and when it is determined that the extracted NDI field has toggled, check the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI. In this case, the one or more processors may be further configured to: when it is determined that the extracted NDI field has not toggled, determine whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identify the received DCI as the true DCI.
And in accordance with yet another aspect, a wireless communication device is configured to detect false downlink control information in a wireless communication network. The device comprises a transceiver configured to receive downlink control information; memory configured to store information associated with one or more physical downlink control channels (PDCCH); a PDCCH decoder configured to perform PDCCH decoding; and one or more processors operatively coupled to the transceiver, the memory and the PDCCH decoder. The one or more processors are configured to: determine whether a PDCCH candidate has been successfully decoded at a first aggregation level of a particular tree structure; when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skip PDCCH candidates at a second, higher, aggregation level within the particular tree structure; perform duplicate PDCCH detection; when the detection determines that the PDCCH candidate is not a duplicate, extract a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and determine whether the HARQ process identity is within an expected limit.
In one example, the one or more processors are further configured to: extract new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message; determine whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and when it is determined that the extracted NDI field has toggled, check the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI. In this case, the one or more processors may be further configured to: when it is determined that the extracted NDI field has not toggled, determine whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identify the received DCI as the true DCI.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a conventional cellular wireless communication system.
FIG. 2 illustrates a conventional wireless communication system.
FIGS. 3 and 3A illustrate subframe level details for the air interface structure of the LTE wireless communication system.
FIG. 4 illustrates different Aggregation Levels for PDCCH in LTE wireless communication system.
FIG. 5 illustrates PDCCH candidate mapping to CCEs for Common Search Space illustrates.
FIG. 6 illustrates PDCCH candidate mapping to CCEs for UE Specific Search Space.
FIG. 7 summarizes the PDCCH Candidates per Search Space and Aggregation Level.
FIG. 8 illustrates the PDCCH CRC generation and XOR-ing with RNTI.
FIG. 9 lists the subframes in which DCI for UL allocation may occur.
FIG. 10 lists the simultaneous parallel reception type required for UE of the LTE wireless communication system.
FIGS. 11A-B illustrate the false PDCCH decoding detection and avoidance according to an aspect of the present invention.
FIG. 12 lists the maximum number of HARQ processes for different (“Time Division Duplex”) TDD configurations.
FIGS. 13A-B illustrate the parsing of DCI for detection and avoidance of false DCI according to an aspect of the present invention.
FIGS. 14A-B illustrate an example of checks to be performed for false DCI detection according to an aspect of the present invention.
FIG. 15 illustrates a diagram of a wireless mobile station usable in accordance with aspects of the present invention.
FIG. 16 illustrates a diagram of a baseband subsystem for a wireless mobile station usable in accordance with aspects of the present invention.
FIG. 17 illustrates an RF subsystem for a wireless mobile station diagram.
DETAILED DESCRIPTION
Methods and apparatus are described that reduce the probability of false PDCCH detection and duplicate PDCCH detection.
According to an aspect of the present invention, some false PDCCH detections may be identified by checking the content of the decoded message. The PDCCH carries payloads of different DCI messages. Each of the DCI messages is transmitted according to a specific format comprising a number of bit fields. The output of the PDCCH decoder is parsed for the expected format. In one scenario, the following list of checks is performed for identifying the false PDCCH detection:
Checks to be Performed to Avoid False PDCCH before DCI Data Parsing
1. Only one SI-RNTI based PDCCH or P-RNTI based PDCCH may be detected in a subframe. 2. Only one RA-RNTI or C-RNTI or SPS-C RNTI or Temp-C RNTI based PDSCH is allowed in a subframe. 3. Only one PUSCH grant (DCI Format 0) based on C-RNTI, SPS-C RNTI or Temp-C RNTI is allowed in a subframe. For TDD Configuration 0, at most two grants, based on C-RNTI, SPS-C RNTI or Temp-C RNTI, are allowed. 4. The protocol software is aware of the maximum number of successful PDCCHs to be expected in any given subframe. This information is used to limit the maximum number of blind PDCCH decoding attempts. 5. In a TDD configuration, some subframes may never carry a UL grant related DCI. In some TDD configurations, some subframes may never carry DL allocation related DCI. This information is controlled by limiting the number of decoded DCIS on a per subframe basis according to the table contained in FIG. 9 .
a. Maximum number of DL DCI matching with C-RNTI [possible values 0, 1] b. Maximum number of DL DCI matching with Temp-C RNTI [possible values 0, 1] c. Maximum number of UL DCI (DCI with Format 0) matching with C-RNTI [possible values are 0, 1, 2]. The value of 2 is only applicable in case of TDD duplexing scheme with TDD Configuration-0. d. Max DCI with Format 0 matching with Temp-C RNTI [possible values are 0, 1]
6. The client terminal may need to use multiple identities, i.e., RNTIs such as RA-RNTI, C-RNTI, SPS-C RNTI, Temp-C RNTI, SI-RNTI, and P-RNTI. The CRC is checked after XOR-ing the received CRC with only the expected RNTIs for any given subframe based on the a priori information and the information exchanged between the UE and eNB. For example, the timing of the transmission of subframes with SI-RNTIs is known to the UE partially before camping on to a cell and fully after camping on to a cell. 7. Some RNTIs are only valid when the client terminal is in certain modes. For example, the P-RNTI is valid only when the client terminal is not having an active data connection with the eNB. Therefore, the P-RNTI is enabled only when the client terminal does not have an active data connection with the eNB. 8. Broadcast messages can only be transmitted by the eNB in the common search of the blind PDCCH decoder. Therefore, any enabled broadcast RNTI (SI-RNTI, P-RNTI, RA-RNTI, Temp-C-RNTI) are used only when the decoded PDCCH candidate is from the CSS. 9. The LTE specifications 3GPP TS 36.302: “Evolved Universal Terrestrial Radio Access (E-UTRA); Services provided by the physical layer” defines a variety of Reception Types as shown in table contained in FIG. 10 . False DCI can be detected based on DL Reception Type violations as follows:
a. Only one SI-RNTI based DCI is allowed in “Reception Type-B” b. Only one P-RNTI based DCI is allowed in “Reception Type-C” c. Only one DCI from “Reception Type D/E/G/I” are allowed d. Only one DCI from “Reception Type F/H/J” are allowed in FDD mode e. One DCI from “Reception Type F/H/J” and one DCI from “Reception Type H/J” are allowed in TDD mode.
The flow diagram contained FIGS. 11A-B illustrate an example of the processing steps for checks to be performed for false DCI before DCI data parsing. The steps 1 through 9 described above are implemented at processing blocks 1102 , 1104 and 1106 in FIG. 11A . The processing blocks 1110 , 1112 , 1114 , 1116 , 1118 , 1120 and 1122 in FIG. 11B implement the checking of the received decoded PDCCH against the information generated by the blocks in FIG. 11A as per steps 1 to 9 paragraph.
For each subframe, a determination is made in block 1102 about the RNTIs for which PDCCH need to be performed for the present operating mode of the UE. This determination is made anew for every subframe. Once the determination is made in block 1102 , the selected RNTIs are configured into the PDCCH decoder as shown in block 1104 .
Next the number of PDCCHs to be received for each RNTI is configured to the PDCCH decoder as shown in block 1106 . Next the PDCCH decoding is started as shown in block 1108 . At this point a decision made in block 1110 as to whether the decoded PDCCH CRC matches with any of the configured RNTIs. If the PDCCH CRC does not match with any of the configured RNTIs, a decision is made in block 1112 whether to continue further PDCCH decoding. This decision is based on whether the maximum number of PDCCH decoding attempts has been completed or not. If the maximum number of PDCCH decoding attempts is completed, then the processing flow jumps to block 1114 and the PDCCH decoding for the given subframe stops at that point. If the maximum number of PDCCH decoding attempts is not completed, then the processing flow returns to block 1108 .
Returning to block 1110 , if the PDCCH CRC matches with one of the configured RNTIs, the number of PDCCH decoded for the matching RNTI is incremented in block 1116 . At this point a check is performed in block 1118 to determine whether the configured number of PDCCHs for a given RNTI is decoded or not. If the configured number of PDCCHs for a given RNTI is not decoded yet, the processing flow returns to block 1112 .
If the configured number of PDCCHs for a given RNTI is decoded, the RNTI for which the configured number of PDCCHs are decoded is removed from the list of configured RNTIs for the current subframe in block 1120 to eliminate it from further PDCCH decoding consideration.
Next a check is performed in block 1122 to determine whether a configured number of PDCCH for all configured RNTIs is received or not. If the configured number of PDCCH for all configured RNTIs is not received, the processing returns to block 1112 . If the configured number of PDCCH for all configured RNTIs is not received, the processing returns to block 1112 . If configured number of PDCCH for all configured RNTIs is received, the processing goes to block 1114 and the PDCCH decoding for the given subframe stops at that point.
Checks to be Done for False PDCCH after DCI Data Parsing
1. Duplicate DCI detection may be performed as follows:
a. The aggregation levels (AL) are defined as trees structured such that the PDCCH candidates at lower aggregation level are subset of PDCCH candidates at higher aggregation level. If a PDCCH candidate is decoded successfully at a lower aggregation level, candidates at higher aggregation level within the same tree are skipped. This may avoid possible duplicate DCI detection. This step is implemented in block 1303 in FIG. 13A . b. Duplicate PDCCH detection may be performed by checking whether the message is identical to another successfully decoded message of the same length. Note that it is possible to have different messages of the same length; therefore comparing the length alone may not be sufficient. Block 1304 in FIG. 13A implements this step. c. Another method to avoid duplicate PDCCH detection is to check whether the CRC of a decoded PDCCH message is identical to the CRC of a previously decoded PDCCH. Block 1404 in FIG. 14A implements this step.
2. The number of HARQ processes for FDD mode is fixed to eight whereas it varies for TDD based on the configuration type as shown in table contained in FIG. 12 . The DCIS with invalid HARQ Process Identity for a given TDD Configuration may be used to detect False DCI. This step is implemented in blocks 1308 and 1310 in FIG. 13A . 3. The New Data Indicator (“NDI”) field value compared to previously received value for a given HARQ process must be consistent with the Modulation and Coding Scheme (“MCS”) and Redundancy Version (“RV”) fields of the DCI message. Specifically, the initial transmission must not use the MCS and RV values that correspond to retransmission. This step is implemented by the blocks 1312 , 1314 , 1316 , 1318 , 1320 and 1322 as shown in FIG. 13B .
The flowchart contained in FIGS. 13A-B illustrates an example of the processing steps for checks to be performed for false DCI detection. The processing flow starts at block 1302 .
In block 1304 a determination is made as to whether the decoded PDCCH CRC matches with any of the previously decoded PDCCH CRC. If the decoded PDCCH CRC matches with any of the previously decoded PDCCH CRC, then the processing jumps to block 1306 where the newly decoded PDCCH is determined to be duplicate of previously decoded PDCCH and it is discarded.
Returning to block 1304 , if the decoded PDCCH CRC does not match with any of the previously decoded PDCCH CRC, the HARQ process ID field is extracted from the DCI payload from the decoded PDCCH. Next, in block 1310 a determination is made whether the extracted HARQ process ID is within the expected limits according to the table contained in FIG. 12 .
If the extracted HARQ process ID is not within the expected limits according to the table contained in FIG. 12 , the DCI is determined to be a false DCI in block 1312 and it is discarded. Returning to block 1310 , if the extracted HARQ process ID is within the expected limits according to the table contained in FIG. 12 , the processing continues in block 1314 where the NDI and MCS fields are extracted from the DCI message.
Next in block 1316 , a determination is made whether the extracted NDI, which is a one bit field, has toggled compared to the NDI value in a last received DCI for the same HARQ Process ID. If the NDI value has toggled, in block 1318 the value of the MCS field is checked to determine whether it is less than 29 to ensure that the required information for a new transmission is available. If the MCS field is less than 29, the received DCI may be determined as true DCI in block 1320 . If the MCS field is greater than or equal to 29, the received DCI may be determined as false DCI in block 1320 . Returning to block 1316 , if the NDI value has not toggled, a determination is made in block 1322 whether the extracted MCS≧29 and if so whether any DCI for the same HARQ process ID was previously received with MCS<29. If the extracted MCS≧29 and a DCI for the same HARQ process ID was previously received with MCS<29, the received DCI is determined to be a true DCI in block 1320 . Otherwise, the received DCI is determined to be a false DCI in block 1312 .
The flowchart contained in FIGS. 14A-B illustrates an example of the processing steps for checks to be performed for false DCI detection. The processing flow starts at block 1402 and follows similar processing steps as in FIGS. 13A-B , but the function of duplicate DCI detection block 1304 is achieved in block 1404 using an alternate method described in step 1 c above.
The above methods can be used independently or jointly to reduce the false and duplicate PDCCH detection probability.
By way of example only, the above-described example methods may be implemented in a receiver, e.g., a user device such as a wireless mobile station (“MS”) 12 as shown in FIG. 1 .
As shown in FIG. 15 , MS 100 may include a baseband subsystem 102 and a radio frequency (“RF”) subsystem 104 for use with a wireless communication network. A display/user interface 106 provides information to and receives input from the user. By way of example, the user interface may include one or more actuators, a speaker and a microphone.
The baseband subsystem 102 and a RF subsystem 104 may be high speed serial communication devices communicating through the high speed communication link.
The baseband subsystem 102 as shown in FIG. 16 may include a controller 108 such as a microcontroller or other processor. The RF subsystem 104 as shown in FIG. 17 may include a controller 108 such as a microcontroller or other processor. The controller 108 desirably handles overall operation of the MS 100 , including management of the RF subsystem 104 . This may be done by software or firmware running on the controller 108 . Such software/firmware may embody any methods in accordance with aspects of the present invention.
A signal processor 110 may be used to process samples from the RF subsystem 104 or other information sent or received by the MS 100 . The signal processor 110 may be a stand-alone component or may be part of the controller 108 . Memory 112 may be shared by or reserved solely for one or both of the controller 108 and the signal processor 110 . For instance, signal processing algorithms may be stored in a non-volatile section of memory 112 while coefficients and other data parameters may be stored in RAM. Peripherals 114 such as a full or partial keyboard, video or still image display, audio interface, etc may be employed and managed through the controller 108 .
The RF subsystem 104 preferably provides two-way communication operation. It may include one or more receivers/receive chains, a transmitter, a synthesizer, a power amplifier, and one or more antennas operatively coupled together to enable communication. The receive chain(s) is operable to receive signals from one or more channels in a wireless communication network. A signal processor 120 may be used to process samples from the baseband subsystem 102 . The signal processor 120 may be a stand-alone component or may be part of the controller 128 . Memory 122 may be shared by or reserved solely for one or both of the controller 128 and the signal processor 120 . For instance, signal processing algorithms may be stored in a non-volatile section of memory 122 while coefficients and other data parameters may be stored in RAM.
Aspects of the present invention may be implemented in firmware of the signal processor 110 and/or the controller 108 of the baseband subsystem. In another alternative, aspects of the present invention may also be implemented as a combination of firmware and hardware of the baseband subsystem. For instance, a signal processing entity of any or all of the FIG. 16 may be implemented in firmware, hardware and/or software. It may be part of the baseband subsystem, the receiver subsystem or be associated with both subsystems. In one example, the controller 108 and/or the signal processor 110 may include or control the protocol entity circuitry. The software may reside in internal or external memory and any data may be stored in such memory. The hardware may be an application specific integrated circuit (“ASIC”), field programmable gate array (“FPGA”), discrete logic components or any combination of such devices. The terms controller and processor are used interchangeably herein.
Aspects of the present invention may also be implemented in firmware of the signal processor 120 and/or the controller 128 of the RF subsystem 104 . In another alternative, aspects of the present invention may also be implemented as a combination of firmware and hardware of the RF subsystem. For instance, a signal processing entity of any or all of the FIG. 17 may be implemented in firmware, hardware and/or software. The software may reside in internal or external memory and any data may be stored in such memory. The hardware may be an ASIC, FPGA, discrete logic components or any combination of such devices.
Although aspects of the invention herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. Aspects of each embodiment may be employed in the other embodiments described herein.
|
In order to support low latency and bursty internet data traffic, the 3GPP LTE wireless communication system uses dynamic allocation. To keep the allocation overhead lower, the system is designed such that the client terminal must perform a number of decoding attempts to detect resource allocations. During course of the decoding attempts a false resource allocation may be decoded by the client terminal. The false detection may lead to multiple issues for the performance efficiency of the client terminal and the overall communication system. A method and apparatus are disclosed than enable the detection of false resource allocation. This in turn improves the performance and efficiency of the client terminal and the wireless communication system.
| 7
|
FIELD OF THE INVENTION
The invention relates to a laser treatment apparatus for ophthalmic surgery, said apparatus comprising a contact glass, which can be placed on the eye and through which a treatment laser beam is incident, and a safety mechanism holding the contact glass movable such that it retracts when a force is directed onto the contact glass counter to the direction of incidence of the laser beam. The invention further relates to a laser treatment apparatus for ophthalmic surgery comprising a beam-deflecting unit which variably deflects a treatment laser beam about at least one axis; focusing optics arranged following the beam-deflecting unit and focusing the laser beam into or onto the eye along an optical axis; a contact glass which can be placed on the eye and is arranged following the focusing optics, and a safety mechanism holding the contact glass movable such that it retracts when a force is directed onto the contact glass counter to the direction of incidence of the laser beam.
BACKGROUND OF THE INVENTION
Such laser treatment apparatuses are used for laser-surgical methods on the eye. In doing so, the treatment laser radiation is focused such that an optical breakthrough causes changes to the tissue. The treatment laser radiation acts, for example, by photo-disruption or photo-ablation. A particularly advantageous application of these effects is found in correction of visual deficiency in ophthalmology. Visual deficiencies of the eye often result from the fact that the diffractive properties of the cornea and of the lens do not cause proper focusing on the retina. In the case of near-sightedness (also referred to as myopia), the focus of the relaxed eye is located in front of the retina, whereas in the case of far-sightedness (also referred to as hyperopia) the focus is located behind the retina. A visual deficiency can also be present in the form of an astigmatism if focusing is not effected in a focal point but with linear distortion.
For correction of visual deficiencies, it is known to suitably influence the diffractive properties of the cornea by means of treatment laser beams. Such methods are described, for example, in U.S. Pat. No. 5,984,916 and U.S. Pat. No. 6,110,166. In this case, a multiplicity of optical breakthroughs are sequentially arranged such that a partial volume is isolated within the cornea of the eye. This isolated partial volume, which is thus separated from the remaining corneal tissue, is then extracted from the cornea through a laterally opening cut. The shape of the partial volume is selected such that the diffractive properties of the cornea after removal of the partial volume are modified so that the desired correction of visual deficiencies is achieved.
In order to form the cut by sequential arrangement of optical breakthroughs, it is, of course, indispensable to generate the optical breakthroughs at exactly predetermined locations. This requires exact positioning of the laser beam in the cornea of the eye. Therefore, displacement of the eye relative to the laser treatment apparatus must be avoided or compensated for as far as possible. U.S. Pat. No. 6,373,571 and WO 0/002008A1, therefore, propose contact lenses which are placed on the cornea of the eye as adapters and immobilize the eye relative to the laser treatment apparatus. The eye is usually secured to the adapter by suction using a vacuum. Such adapter, also referred to as contact glass, performs two functions: on the one hand, it deforms the eye in accordance with the adapter's predetermined surface shape. Thus, a defined surface shape is present in the beam path of the laser treatment apparatus. On the other hand, the contact glass fixes the eye and thereby prevents displacement of the eye during therapeutic intervention.
In order to hold the contact glass securely to the eye even when the patient moves, U.S. Pat. No. 5,336,215 proposes a device of the above mentioned type, wherein the lens focusing the laser radiation is seated in a frame together with a contact glass, which frame is in turn resiliently suspended. The lens and the contact glass are thus displaceable together along the optical axis of incidence of the treatment laser radiation. Any movement by the patient will thus automatically lead to a displacement of the contact glass and of the focusing optics in the beam path. Such movement of the optics has meanwhile turned out to be disadvantageous in terms of the quality with which the treatment laser beam can be focused.
As a remedy, it might be conceivable to mount the contact glass and the focusing optics permanently and irremovably to the laser treatment apparatus. However, this approach involves the risk of the eye being damaged by by bruising when the patient moves. Such movement could either be caused by a physical movement of the patient or could occur when placing the eye in contact with the contact glass.
Therefore, it is an object of the invention to improve a laser treatment apparatus of the above-mentioned type such that the safety mechanism can reliably avoid squeezing of the eye without adversely affecting the optical quality of the laser treatment apparatus.
This object is achieved in a laser treatment apparatus for ophthalmic surgery, said apparatus comprising a contact glass which can be placed on the eye and through which a treatment laser beam is incident, with a safety mechanism being provided which holds the contact glass movable on the housing such that the contact glass retracts when a force is directed onto the contact glass in a direction opposed to the direction of incidence of the laser beam, the safety mechanism enabling such retraction only in case of a force which exceeds a limit value of force and holding the contact glass fixed at a force which is below the limit value of force.
According to the invention, the object is further achieved by a laser treatment apparatus for ophthalmic surgery, said apparatus comprising a beam deflecting unit which variably deflects a treatment laser beam about at least one axis; focusing optics arranged following the beam-deflecting unit and focusing the laser beam along an optical axis into or onto the eye; a contact glass which is arranged following the focusing optics and can be placed on the eye, and a safety mechanism holding the contact glass movable in such a manner that it retracts when a force is directed onto the contact glass counter to the direction of incidence of the laser beam, wherein the beam-deflecting unit is arranged in the entrance pupil of the focusing optics, with respect to a deflecting element being effective for said one axis of deflection, and the safety mechanism couples the contact glass, the focusing optics and the deflecting element such that, during retraction, the deflecting element remains in the entrance pupil and the length of the light path between the deflecting element and the contact glass is constant.
According to the invention, the object is also achieved by a laser treatment apparatus for ophthalmic surgery, said apparatus comprising a contact glass which can be placed on the eye and through which a treatment laser beam is incident, and a safety mechanism holding the contact glass movable in such a manner that it retracts, when a force is directed onto the contact glass counter to the direction of incidence of the laser beam, wherein the safety mechanism comprises a detecting unit, which monitors retraction of the contact glass and which interrupts laser treatment operations of the laser treatment apparatus in case of a contact glass movement exceeding a threshold value.
Thus, the invention fundamentally deviates from the concept pursued by the prior art, which consists in compensating for any eye movements by a resilient support of the contact glass, and provides a contact glass which is rigid under certain basic conditions. In a first version of the invention, this rigidity is embodied such that the contact glass is movable only above a limit value of force. Thus, optimal optical conditions are ensured during irradiation of the eye with the treatment laser beam, and at the same time, compression of the eye is prevented, because the limit value of force causes a sort of panic release mechanism.
In another version of the invention, the rigidity of the contact glass does not relate to the eye, but to the mutual position of the contact glass, the focusing optics and the deflecting element. The coupling of the safety mechanism having this effect now allows movement of the contact glass due to eye or head movements of the patient, but now these movements have no effect on the optical properties of the focusing of the treatment laser beam.
In a third version of the invention, the rigidity of the contact glass provided for according to the concept of the invention is achieved in a functional manner. Laser treatment operation is interrupted if the contact glass is moved beyond a certain maximum amount.
Thus, the above-mentioned solutions provided by the invention realize different variants of the same inventive concept, namely to cause rigidity of the contact glass by means of a safety mechanism, said rigidity preventing unwanted defocusing or faulty positioning of the treatment laser radiation by eye movements or head movements. As mentioned above, said rigidity can be realized either structurally, with respect to the eye or the optics of the laser treatment apparatus, or functionally. These three approaches will be referred to hereinafter as the first variant (retraction of the contact glass above a limit value of force), the second variant (coupling of the contact glass, the focusing optics and the deflecting element) and the third variant (abortion of laser treatment if a movement of the contact glass exceeds a threshold value), respectively.
All three variants have in common that they prevent bruising of the eye. If there is danger of bruising, the contact glass and the patient are moved apart. This fact is referred to herein as retraction. This means, on the one hand, that the contact glass as well as possibly further parts of the laser treatment apparatus are moved away from the desired position of the patient. On the other hand, this term, of course, also covers a kinematically reversed approach, wherein the patient is moved away from the contact glass. From the patient's view, this is also a retraction of the contact glass, which justifies the generalization made herein.
Of course, the variants of the invention can also be combined with each other. This also applies to any embodiments and improvements.
In the first variant of the invention, an increase in the pressure which the patient exerts on the laser treatment apparatus, for example by his eye, only leads to a retraction of the contact glass if the limit value of force has been exceeded. Bruising of the eye is excluded if a suitable limit value of force is selected, and at the same time optimal operation is achieved under normal conditions.
In a particularly simple construction, the limit value of force is caused by an elastic force or weight force. One possibility of achieving this, is, for example, an elastic support for the patient on a bed, which support is selected such that the patient's bed retracts upon an apparent increase in the patient's weight. An increased pressure of the eye on the contact glass manifests itself in such apparent increase in the patient's weight so that the desired retraction then occurs. The laser treatment apparatus or the optical component of this apparatus can remain spatially fixed. Instead of the described possibility of mechanical compensation, a corresponding closed-loop control can also be effected, of course, e.g. in the form of electronic closed-loop control.
In a kinematically reversed construction, which is comparatively more simple in mechanical terms, it is advantageous to mount the contact glass to a holding element, which is pressed against a stop of the housing by a force defining the limit value of force. In case of a contact pressure force exceeding the limit value of force, the contact glass can then be displaced relative to the housing so that the desired safety features are achieved. Retraction is then effected by the contact glass; the bed need not be moved for this purpose.
This can also be combined by mounting a force sensor to the holding element but effecting retraction through movement of the bed.
In an advantageous further embodiment of the invention, laser treatment can be continued even if the contact glass retracts, as long as certain basic conditions are complied with. For this purpose, retraction not only of the contact glass, but also of the relevant components of the optics by which the treatment laser beam is focused into or onto the eye is convenient. Therefore, the holding element which is mounted to the contact glass may also carry focusing optics which focus the treatment laser beam into or onto the eye. When retracting, the contact glass and the focusing optics then move together.
The limit value of force is conveniently set such that bruising of the eye is definitely prevented. A suitable value for this purpose is approximately 1N.
The first variant of the invention is suitable not only to prevent damage caused by a patient's fault, but apparatus malfunction can also be checked thereby. During laser treatment, the patient is usually supported on a bed. A height adjustment unit allows adjustment of the distance between the laser treatment apparatus or the contact glass, respectively, and the patient. The safety mechanism according to the invention reliably prevents malfunction of this height adjustment mechanism resulting in bruising of the eye. If, for example, the height adjustment mechanism moves the patient too far towards the contact glass, the safety mechanism automatically causes retraction of the contact glass before there is a risk of the eye being squashed.
The second variant of the invention ensures that retraction of the contact glass has as little effect as possible on the optical quality with which the treatment laser radiation is introduced into the eye. Since in a laser treatment apparatus the laser treatment beam is guided to a great diversity of points (e.g. during the above-mentioned correction of visual deficiencies), three-dimensional shifting of the focus of the laser beam is usually required. This regularly requires deflecting elements in the form of two scanners, for example galvanometer scanners, for lateral movement of the laser focus.
In a simple construction, optical errors which occur during retraction of the contact glass can be minimized by rigidly connecting the contact glass and the focusing optics which focus the treatment laser beams into the eye such that they retract together. If a beam path section which is insensitive to changes in the length of the optical path, for example a parallel or near parallel beam path, is additionally arranged preceding the focusing optics, the optical errors occurring during retraction of the unit consisting of the focusing optics and the contact glass are automatically small.
In order to minimize errors induced by retraction of the contact glass, it is generally advantageous if the length of the light path following the deflecting element remains unchanged even during retraction. Otherwise, the distance in a projecting lens would change, which would be equal to a change in the effective focal length of the entire system. In particular, curved contact glasses, which have a concave curvature on the side facing towards the patient and which thus only add little to the internal pressure of the eye, would be difficult to use. Instead, contact glasses would have to be used, which flatten the front surface of the eye and are, therefore, disadvantageous with a view to keeping the internal pressure of the eye as constant as possible. Therefore, further minimizing is achieved if the contact glass, the focusing optics and at least one of the deflecting elements of the beam-deflecting unit are connected to form one single unit, and the safety mechanism causes longitudinal guiding of this unit.
The second variant of the invention then keeps the distance between the deflecting unit and the focus of the treatment laser radiation constant. If the axial position of the laser focus were shifted, unpredictable side effects could appear in the patient's cornea. In the worst case, a laser effect could even damage the epithelium or the endothelium.
The deflecting elements, e.g. AOD or scanners, are favourably arranged in pupil planes of the optics. In most cases, they effect beam deflection about two mutually perpendicular axes. However, other approaches, e.g. using a tumbling mirror, are also possible, if they effect 2-dimensional beam deflection. Common scanners operate by reflection at surfaces which are variable with respect to their clearance angle relative to the beam path. This has the effect that the entire beam path is folded at an angle at the scanners. In doing so, folding angles of approximately 90° are preferably realized. It is advantageous to design one of said bends such that part of the optical system is supported there rotatable about an axis. Retraction of the contact glass can then be achieved by rotating the optical system about said bend, so that the subsequent beam path is only pivoted, in principal, but otherwise does not change. If another deflection of the beam path, e.g. by 90°, is provided at this bend, retraction of the contact glass is realized as a pivoting movement about the axis of rotation located in the first bend. This enables pivoting of the subsequently arranged optics about the bend and, thus, a retraction of the contact glass without any changes appearing in the beam path.
Therefore, it is preferred that the light path of the laser beam be deflected at least once following the entrance pupil of the focusing optics and that the safety mechanism cause a joint rotary or pivoting movement of the contact glass, the focusing optics and the deflecting element during retraction. A particularly convenient construction is one in which the contact glass, the focusing optics and the deflecting element are rigidly connected to form an arm and the safety mechanism comprises a rotary support for the arm with the axis of rotation in the plane of the deflecting element. The arrangement of the axis of rotation at the deflecting element has the advantage that, during rotation or pivoting, no disadjustments are generated with respect to deflection.
However, a weight compensation may be necessary, because the rotary or pivoting movement requires the entire optical unit to be raised from the contact glass up to the pupil with the deflecting element. Therefore, it is favourable for this embodiment to provide corresponding balancing weights, reducing the force required to raise the arm and thus to retract the contact glass.
This embodiment is a variant of a generally preferable safety mechanism comprising a weight force compensation unit, in particular in the form of a counterweight or a spring element. If it is desired to combine the advantages of the first or second variants, the weight force compensation unit can conveniently set the limit value of force. In particular, it is possible for the arm to be supported by the housing of the laser treatment apparatus at the limit value of force.
Another approach involves placing the axis of rotation in the beam path at the location of the weight center of gravity, because, in doing so, a balanced structure and, consequently, a low force for the retraction of the contact glass is automatically achieved.
In the third variant of the invention, a detecting unit is provided for functional rigidity of the contact glass, which unit blocks the laser treatment operation upon a contact glass movement exceeding a threshold value. In this case, the threshold value can be selected according to different criteria. Depending on the design of the laser treatment apparatus, the threshold value can be selected in the sense of an emergency deactivation, which deactivates just before an inadmissibly great load on the eye, or may serve as a quality-ensuring feature and may consider the optical errors caused by said movement.
If the threshold value is selected such that it should prevent an inadmissibly high eye pressure, deactivation is effected before retraction of the contact glass reaches a mechanically determined end of said movement. Even after the threshold value has been exceeded, counter measures can still be initiated without the contact glass abutting at the end of its movement. For example, a height adjustment mechanism of the patient's bed can be deactivated or the patient's bed can be quickly lowered.
Thus, one of the counter measures consists in actively moving the contact glass and the eye apart. Therefore, it is preferred that the safety mechanism comprise a drive for active retraction of the contact glass and that a control unit control the drive to actively retract the contact glass in case of a force exceeding the limit value of force or a contact glass movement exceeding the threshold value, respectively.
In the case of the above-mentioned rotatable or pivotable optical arrangement of the second variant, the drive will usually initiate a pivoting or rotary movement, in particular rotating the arm mentioned above with respect to the second variant.
The detecting unit may use a light barrier located near a mechanical stop for the path of movement of the contact glass. Of course, a multi-level stepwise response detecting unit or continuous monitoring of the position of the contact glass is also possible according to the invention.
One possibility of additionally detecting that a desired maximum movement is exceeded consists in sensing at the mounting mechanism by which the eye is fixed to the contact glass. For this purpose, a vacuum is conventionally used. The detecting unit may then sense the pressure in the vacuum system and thus determine an inadmissible movement of the eye relative to the contact glass.
Due to the human physiognomy an eye movement directed towards the contact glass automatically involves a movement of the head. Therefore, it is possible to sense the force directed towards the contact glass not only at the eye, but also at the patient's body, preferably at the head. This procedure gives further protection to the eye. Therefore, it is convenient for all the above mentioned variants if a supporting unit is provided comprising a support that can be applied to the patient's body and is coupled to the safety mechanism such that a certain force on the support opposed to the direction of incidence of the laser beam also causes retraction of the contact glass. In the third variant, the detecting unit may detect pressure on the support.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail below, by way of example and with reference to the drawings, wherein:
FIG. 1 shows a schematic perspective view of a laser treatment apparatus for treatment of a patient lying on a patient's bed;
FIG. 2 shows a schematic partial view of the beam path of the laser treatment apparatus of FIG. 1 , viewed against the patient's viewing direction;
FIG. 3 shows a representation of the beam path of FIG. 2 in a plane rotated by 90°, i.e. as seen by a surgeon sitting behind the patient;
FIGS. 4 and 5 show representations of a laser treatment apparatus similar to that of FIG. 3 in a similar view as in FIG. 3 ;
FIGS. 6 and 7 show representations of a further modified laser treatment apparatus in a view similar to those of FIGS. 4 and 5 ;
FIG. 8 shows a schematic representation of the laser treatment apparatus of FIG. 1 with a modified construction in a view similar to that of FIG. 3 ;
FIG. 9 shows a weight balancing mechanism provided in the laser treatment apparatus of FIG. 1 ;
FIG. 10 shows a schematic representation of a laser treatment apparatus similar to that of FIG. 1 , but in lateral reversal, comprising an additional safety mechanism in order to protect a patient against bruises;
FIG. 11 shows an enlarged detail of FIG. 10 ;
FIG. 12 shows a diagram illustrating the forces appearing at the eye during operation of a laser treatment apparatus according to FIG. 1 , and
FIG. 13 shows a schematic representation of a circuit diagram for the laser treatment apparatus of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a laser treatment apparatus in the form of a laser-surgical treatment station 1 . It comprises a bed 2 on which a patient (not shown) is made to lie down during treatment. A laser unit 3 comprising a treatment head 4 is arranged beside and above the bed. The distance between the bed 2 or the patient lying thereon, respectively, and the treatment head 4 can be adjusted by a height adjustment unit 5 provided at the bed 2 . The treatment head 4 is arranged on a cantilever 6 of the laser unit 3 such that it protrudes beyond a patient's head.
A surgeon can survey the progress of treatment through a microscope eyepiece 7 provided at the cantilever 6 . A keyboard 8 as well as a monitor 9 serve to adjust parameters of the laser treatment method. The laser-surgical treatment station 1 is controlled by a computer C and is intended for ophthalmic correction of visual deficiencies.
The treatment head 4 has a nozzle 10 , at which a treatment laser beam exits, and which nozzle contacts the eye for treatment. As will be explained below, the treatment head 4 comprising the nozzle 10 is movably supported within the cantilever 6 so that further space for movement exists between the nozzle 10 and a patient lying on the bed 2 , or his eye respectively, in addition to the adjustability moved by the height adjustment unit 5 .
FIG. 2 shows a detail of the treatment beam path 11 , which is used by the laser-surgical treatment station 1 in order to focus treatment laser radiation L in the eye of the patient, to thereby generate optical breakthroughs and to ultimately effect correction of visual deficiency. The laser unit 3 comprises a laser emitting the treatment laser radiation L and expansion optics expanding the treatment laser radiation L.
These two elements are of no further relevance to the safety function of the laser-surgical treatment statement 1 , which function is to be explained herein, and are therefore not shown in the Figures. The expansion optics include axially displaceable elements so that the laser focus can be shifted in an axial direction with the cornea.
Following the expansion optics, a first scanner is arranged comprising a scanning mirror 12 , which is driven by a motor 13 to be pivotable about a first deflecting axis S 1 . The first scanning mirror 12 is located in a pupil of an optical system which will be explained later. Following the first scanning mirror 12 , the pupil is imaged at elements 14 to ensure that the first scanning mirror 12 is located in a pupil of the optical system. In a further pupil lies a second scanning mirror 15 , which is also driven by a motor 16 . The axis of rotation of the second scanning mirror 15 is perpendicular to the deflecting axis S 1 of the first scanning mirror 12 . The second mirror 15 rotates about a second deflecting axis S 2 , shown in broken lines in FIG. 3 . The deflecting axes S 1 and S 2 of the two scanning mirrors 12 and 15 are at right angles to each other.
Arranged following the second scanning mirror 15 are scanning optics 17 , in whose pupil the second scanning mirror 15 is located and whose beam path is deflected into the nozzle 10 by a beam splitter 18 . The nozzle 10 contains focusing optics 20 which focus the laser radiation L via a contact glass 23 into the cornea 21 of the patient's eye 22 . The beam splitter 18 couples in an observation beam path 19 for the microscope eyepiece 7 . At the same time, it deflects the beam path after the second scanning mirror 15 by 90°.
The scanning optics 17 , the beam splitter 18 , the focusing optics 20 and the contact glass 23 form an arm 24 . The arm 24 is mounted to a rotary joint 25 together with the motor 16 and the scanning mirror 15 . As a result, the arm 24 is pivotable about the rotary joint. The pivoting axis is located in the pupil, in which also the scanning mirror 15 is arranged, and extends perpendicular to the deflecting axis S 2 . Pivoting of the arm 24 consequently moves the contact glass 23 away from the cornea 21 .
The scanning optics of the embodiment according to FIGS. 2 and 3 is mounted to a support 26 and is thus combined to the arm 24 . This arm is connected to the rotary joint 25 in the form of a ball bearing. The axis of the ball bearing—for the sake of stability, a plurality of bearings can also be used on a common axis—is identical with the optical axis of the preceding pupil imagery 14 . For example, a very large ball bearing having a large diameter can be used and placed directly on the mount of the pupil imagery 14 . Thus, simple centering of the rotary joint 25 relative to the optical axis of the pupil imagery 14 is achieved, and the pivoting axis is located exactly in the pupil plane. The mounting of the second scanner 15 to the rotary joint provided here, which mounting, of course, is understood to be optional, ensures that the deflecting axes S 1 , S 2 of the two scanners 12 , 15 remain perpendicular to each other even when the arm 24 is raised and the beam reflected by the second scanning mirror 15 nevertheless always passes through the scanning optics 17 in a predetermined direction even when the arm 24 is pivoted.
Of course, it is alternatively possible to also have the pupil imaging elements 14 rotate together with the scanning optics 17 , i.e. with the arm 24 . This allows to realize a great length of guidance for the axis of rotation, thus achieving greater accuracy in guiding. In a further embodiment of this approach the entire optical unit, including laser(s), rotates. Such embodiment is favorable in terms of stability of the entire optical arrangement, but the forces of inertia which have to be overcome in order to initiate retraction of the contact glass increase with the mass of the supported unit.
In a further embodiment fiber coupling between the laser and its expansion optics is used. In this case all remaining elements of the optics are mounted on the pivotable supporting unit. Advantageously a chirp caused by the fiber is compensated for by a compressor unit either before entering the fiber or thereafter. The compressor unit is preferably arranged preceding the fiber, because the peak performance in the fiber is reduced thereby and light intensity-dependent damage to the fiber is avoided. At the same time self-phase modulation is reduced.
The construction of FIGS. 2 and 3 in the laser-surgical treatment station 1 of FIG. 1 allows the patient to push away the contact glass 23 , which is being mounted to his eye by means of a vacuum, for example. The contact glass 23 can move away from the eye together with the focusing optics 20 and the scanning optics 17 and relieve the eye in order to avoid bruises. However, due to the mass of the elements to be moved initiation of said movement may require a force which cannot be applied via the patient's eye alone without auxiliary means.
Therefore, in the case of bulky optical structures, an embodiment as shown in FIGS. 4 and 5 is provided. In this case the arm 24 is stiffened by the support 26 to which the scanning optics 17 , including the beam splitter 18 and the nozzle 10 , are mounted. Further, a spring suspension 27 reducing the static forces is effective at the free end of the support 26 . The arm 24 or the support 26 , respectively, is further supported by the cantilever 6 such that it contacts the latter with a defined force. This bearing load is set by the suspension 27 .
Thus, by exerting pressure on the contact glass 23 , the patient can push the arm 24 on the support 26 away from himself using comparatively little force, so that the arm reaches the raised position shown in FIG. 5 . It is merely required to overcome the bearing load. The force required to do so is set such that bruising of the eye is avoided. For instance, said force is 1N.
FIG. 5 further clearly shows that the scanning mirror 15 rotates along with the pivoting of the arm 24 . Thus, the coupling of the laser radiation from the scanning mirror 15 into the scanning optics 17 remains unchanged even if the support 26 is deflected and the contact glass 23 is thus raised.
However, the construction of FIGS. 4 and 5 can not compensate for dynamic forces which are required in order to initiate rotation of the arm. Such dynamic forces appear as forces of inertia, when the patient moves towards the contact glass, because the bed 2 is being moved upwards. For acceleration of the arm 24 which is required for the contact glass 23 to retract, an additional force is required which can lead to at least temporary squeezing of the eye. In order to avoid this effect, which becomes relatively large from a certain moment of inertia of the arm 24 mounted to the rotary joint 25 , it is favorable to provide a mechanism which actively retracts the contact glass 23 , i.e. which assists the eye during acceleration of the contact glass 23 on the arm 24 . For this purpose, it is necessary for the construction described herein to actively raise the arm 24 .
FIGS. 5 and 6 show an exemplary embodiment of such mechanism operating here by means of a vacuum. A vacuum cell is mounted to the rotatable end of the arm 24 at the support 26 . If there is negative pressure in the vacuum cell, it contracts and raises the support 26 at its free end. This condition is shown in FIG. 7 . By means of a sensor 29 , which is provided here as a mechanical feeler 30 actuating a switch 31 , a control unit 32 is switched on as soon as the patient raises the arm 24 by a certain minimum amount from the arm's lower position. The control unit 23 then activates the negative pressure drive 28 which raises the support 26 with the arm 24 and, thus, pulls the contact glass 23 away from the eye. A small movement of the scanning optics, thus, leads to actuation of the negative pressure drive.
In a modified form only a part of the scanning optics or an additional part mounted to different optics may be mounted axially moveable with the rest of the scanning optics. If this component is moved upwards by the pressure of the eye, a corresponding signal for the control unit 32 is derived, which in turn activates the negative pressure drive 28 . In doing so, the valve actuation required for this purpose can also be effected directly by mechanical means or even electrically. Of course, sensing of the scanning optics' movement can also be effected contact-free, e.g. by light barriers or a capacitive distance sensors.
As an alternative to the negative pressure drive described here, any suitable drive is conceivable, of course, for example also one comprising electrically driven servo motors.
Instead of or in addition to actively driving the arm 24 , support by way of a mechanical spacer can be used as shown in FIG. 8 . The spacer comprises a stem 34 , which can be placed in contact with the patient's head 33 and contacts the patents' forehead 35 when the contact glass 23 is in place. In doing so, the stem 34 is set such by a locking mechanism that it contacts the forehead 35 directly. The stem extends parallel to the direction of irradiation along which the laser treatment radiation L is incident in the contact glass 23 and the cornea 21 through the nozzle 10 . As soon as the cornea 21 contacts the contact glass 23 , the stem is displaced downwards, e.g. moved by the force of its own weight, such that it contacts the patient's forehead. In this position, it locks automatically or is externally locked. If the patient's eye 22 moves upwards now, the arm 24 is automatically raised by the stem 34 .
In addition or as an alternative to the stem 34 , support may also be effected directly at the patient's bed 2 . Thus, inadvertent actuation of the height adjustment unit 5 is immediately converted to retraction of the contact glass 23 by pivoting of the arm 24 .
It is also possible to cause actuation of the negative pressure drive 28 by purely pneumatic means. The feeler 30 then actuates a switch 31 , which is provided as a valve and is located in a vacuum duct between a vacuum source, which corresponds to the control unit 32 in the drawing, and the negative pressure drive 28 . The valve is opened when the feeler 30 has moved upwards, as is the case during a slight movement of the support 26 with the arm 24 . When the valve is open, the negative pressure drive 28 is evacuated, contracts and thereby tilts the support 26 with the arm 24 upwards.
If the optics accommodated in the arm 24 have a suitable design, the suspension 27 is sufficient to avoid bruising of the patient's eye. Assuming a length of the arm of half a meter and realizing a moment of inertia of the arm 24 of 2 kg·m 2 , an eye movement at 6 mm per second towards the contact glass 23 , at a radius of curvature of 7.8 mm and a radius of curvature of the contact glass of 2 cm leads to a force of 0.3N, if the eye is pushed in by 0.77 mm during acceleration of the contact glass 23 . The contact glass 23 with the entire arm 24 is then accelerated to the speed of movement of the eye within a third of a second. Thus, it is evident that an external drive is not stringently required if the arm 24 is skillfully designed.
FIG. 9 shows a possible design of a spring mechanism serving the function of the suspension 27 . It is a supporting mechanism 37 which supports the arm 24 from below. The arm 24 is supported on a roll 38 which is connected to a spring 41 via a lever 40 , said spring pushing the roll 38 upwards. The weight force of the arm 24 acting in the direction of the arrow 39 can be compensated for as desired, except for a residual bearing load, by suitably selecting or positioning the spring 41 .
It is of absolutely no importance in the constructions described above whether the actuating movement is caused by the patient or by a movement of the bed 2 . The arm 24 is always raised.
FIG. 10 shows a further detailed view of an extension 6 of a laser-surgical treatment station similar to the construction shown in FIG. 1 , although the representation in FIG. 10 is mirror-inverted relative to that chosen in FIG. 1 . It is evident again that the arm 24 with the nozzle 10 is provided in the extension 6 , of which merely some components of a housing B are shown. The arm 24 is pivotable with the support 26 relative to the extension 6 about a pivot point located to the left in FIG. 10 , but not shown. In this pivotal movement, the nozzle 10 is raised relative to the housing B such that it retreats into the housing B. The arm 24 or the support 26 , respectively, contacts the extension 6 at a support not illustrated. LRaising the extension 6 can be effected by a force acting on the nozzle 10 (via the contact glass 23 ).
In the construction of FIG. 10 , a safety mechanism is additionally provided which also protects the patient's body from bruises caused by the arm 24 . For this purpose, a baffle plate 42 is mounted to the housing B by means of a joint 43 , which may be designed, for example, as a bendable attachment in the form of a steel plate. The baffle plate 42 is supported on the arm 24 or its support 26 by a ridge 45 . A force acting on the baffle plate 42 in the direction of the arrow 44 thereby exerts an upward pressure on the arm 24 . A position sensor 46 detects raising of the arm 24 . A possible embodiment of this position sensor 46 , which senses the displacement of the arm 24 relative to the housing B or the extension 6 , respectively, is shown by way of example in FIG. 11 .
As is evident from FIG. 11 , light barriers 48 and 49 comprising slits 50 and 51 are mounted to a mounting surface 47 of the extension 6 on the housing side. Through these slits a position mark 42 can pass which is attached to the support 26 or to the arm 24 , respectively. Thus, when the arm 24 is raised, the position mark 52 moves into the slot 50 and, if raised further, also into the slot 51 . If the position mark 52 is located in the slot 50 or 51 , respectively, of the light barrier 48 or 49 , it generates a corresponding signal which is transmitted to a control unit (not shown), for example the computer C of the laser-surgical treatment station 1 (cf. FIG. 1 ). The computer C then controls a corresponding reaction of the system, for example deactivating the treatment laser radiation L or lowering of the patient's bed 2 .
FIG. 12 schematically shows an exemplary relationship between the position P of the arm 24 or of the nozzle 10 , respectively, of the laser-surgical treatment station 1 and the force F on the eye of the patient, each as a function of the eye's position x, which is given for a patient lying on the bed 2 by the position of the height adjustment unit 5 . When a patient is being prepared for treatment, a new, sterile contact glass 23 is first attached to the nozzle 10 . Then, the patient is placed on the bed 2 whose height adjustment unit 5 is controlled by the surgeon at the laser-surgical treatment station 1 . For this purpose, the computer C comprises a suitable input device, for example a joy stick, and controls the height adjustment unit 5 accordingly. At the beginning the height adjustment unit 5 is moved downwards, resulting in the location x 0 . At the same time, the nozzle 10 is located at its lowermost position P 0 , because the arm 24 contacts the extension 6 at the lower stop. The surgeon then moves the patient upwards by means of the height adjustment unit 5 until the patient's eye contacts the contact glass 23 at the location x 1 . The surgeon now slowly moves the patient further up, until the eye fully contacts the contact glass 23 . This is the case at the location x 2 , which is characterized in that the vacuum for fixing the contact glass 23 to the cornea 21 can be applied.
In order for the cornea 21 to contact the internal surface of the contact glass 23 as completely as possible, the eye 23 presses against the contact glass 23 with a certain force. However, since this force is still weaker than the force Fmin, by which the arm 24 is raised, the arm 24 continues to rest in this case.
Upon activating the vacuum, the computer C automatically raises the height adjustment unit 5 slightly, so that the bed 2 is still raised slightly above the location x 2 , in order to ensure secure fixation of the contact glass 23 to the cornea 21 by means of a vacuum. The height adjustment unit 5 or the patient's head, respectively, is thus located between the locations x 2 and x 3 . The eye presses against the contact glass 23 with a force below the minimum force Fmin, so that the arm 24 still remains in the position P 0 , i.e. is not raised. The eye is fixed to the contact glass, and treatment can be started.
If the patient's head moves upwards during treatment, for example because the patient is moving his head, or due to an involuntary actuation of the height adjustment unit 5 , the force on the arm 24 will not be equal to the minimum force Fmin with which the arm 24 contacts the cantilever 6 , until the location x 3 is reached. Upon a further upward movement of the head, the cantilever 24 will be raised. This case corresponds to the rising of graph 53 (shown as a solid line) in FIG. 12 , and the arm 24 leaves its resting position P 0 . If the cantilever has reached the position P 1 , because the patients head, or in the case of a malfunction or faulty operation, the height adjustment unit 5 has reached the location x 4 , the first light barrier 48 will output a switching signal. Because the arm 24 can be lifted through the set force Fmin, the force exerted on the eye, and, thus, the pressure on the eye does not increase any further.
The switching signal reached at position P 1 causes the computer C to switch the laser beam L such that no treatment is effected anymore. For example, the laser can be switched off or the laser beam energy can be reduced such that no optical breakthroughs are generated anymore. Moreover, it is possible to output an alert to the surgeon, for example in the form of a corresponding display on the monitor 9 .
Finally, a switching mechanism can be provided in the computer C, which mechanism automatically moves the height adjustment unit 5 downwards, i.e. to lower x-values, upon reaching position P 1 , in order to lead the eye back into the normal treatment region between x 2 and x 3 . Once this has been achieved, the switching signal from the light barrier 48 changes back to the resting condition, normal treatment operation is resumed and the alert is deactivated. If the relative movement of the eye and the contact glass is caused only by moving the bed, the switching mechanism can be adapted to the x-values such that, for example, movement is effected upon reaching x 3 .
However, if the arm 24 moves further up due to a malfunction or a corresponding action by the patient and reaches position P 2 , the second light barrier 49 will respond and the computer C will then initiate an emergency shutdown, which deactivates the height adjustment unit 5 and moves it down, on the one hand, as well as deactivating the laser-surgical treatment station 1 , except for the control, on the other hand. This happens in order to prevent that beyond the location x 5 the location x 6 is reached, where the arm 24 arrives at its maximum deflection at position Pmax, at which no further retraction is possible. If the raising movement of the head still continued, the force on the cornea 21 or on the eye 22 would suddenly increase from the location x 6 onwards, as clearly shown by the curve of force 24 of FIG. 12 . At the location x 7 , the maximum admissible force Fmax on the eye 22 would be reached and there would be danger of bruising.
Due to the emergency shutdown of the laser-surgical treatment station 1 effected at the location x 5 or the position P 2 , bruising of the eye 22 is avoided even if the patient panics.
Since the baffle plate 42 is located below the cantilever 6 in the embodiment according to FIG. 10 , bruising of the patients body is also avoided, which may occur if the height adjustment unit pushes the patient against the cantilever 6 .
FIG. 13 shows a circuit which may be realized for example by the computer C in order to carry out the method of protection described with reference to FIG. 12 . FIG. 13 shows the exemplary light barriers 48 and 49 of FIG. 11 generally as sensors sensing whether the arm 24 has reached positions P 1 or P 2 , respectively. FIG. 13 further schematically illustrates a suction pressure sensor 55 , which monitors whether the vacuum used for suction of the contact glass 23 is in a range of values in which reliable suction of the eye 22 to the contact glass 22 is given. The sensors as well as the vacuum sensor 55 act on a drive 56 of the height adjustment unit 5 in a manner yet to be described. The drive 56 is supplied by a d. c. source 57 , which feeds a power supply 58 of the drive 56 . The current source 57 is connected to the power supply 58 by two lines. Two emergency switches 59 and 60 are switched into a feed line, which open upon actuation and which are closed in their deactivated condition.
The emergency switch 59 is controlled by the second light barrier 49 , and the emergency switch 60 serves as a mechanical emergency switch for the surgeon, so that the connection between the current source 57 and the power supply 58 of the drive 56 can be interrupted at any time, and thus, the drive 56 can be deactivated.
The drive 56 further comprises a blocking mechanism 61 whose actuation deactivates the drive 56 . Such blocking occurs if a vacuum sensor 62 indicates that the suction of the eye 22 to the contact glass 23 is switched on and also if the vacuum sensor 55 indicates suction of the eye. In this condition the blocking mechanism 61 prevents any further action of the height adjustment unit 5 by the drive 56 because a shift in the height adjustment unit 5 may not be required and may even cause damage when the eye is subject to suction.
The drive 56 is further provided with a blocking mechanism 63 , which is controlled by the first light barrier 48 and, in parallel with the locking mechanism 61 , prevents any activity of the drive 56 when the first light barrier 58 indicates that the arm 24 has reached position P 1 . This prevents the height adjustment unit 5 inadvertently being actuated and raising the patient, which would be possible if the vacuum were cut by a movement of the patient and the vacuum sensor 55 thus no longer signaled that the eye is subject to the correct suction. Thus, for example when the patient moves sideways or upwards, operation of the drive 56 and, consequently, action of the height adjustment unit 5 is also prevented.
The parallel provision of the locking mechanism 61 as well as the blocking mechanism 63 thus allows to effect closed-loop control by means of the height adjustment unit 5 , said control guaranteeing secure suction of the eye.
The second light barrier 49 , which emits a signal when the arm is in position P 2 , is connected to the emergency switch 59 via a relay 64 . If the second light barrier 49 emits a signal indicating position P 2 , the emergency switch 59 will be opened and the drive 56 will be de-energized. Depending on the design of the drive 56 , the bed 2 then remains at the presently set height or smoothly glides downwards.
The described system according to the invention avoids bruising of the eye in a laser-surgical treatment station, due to the component which contacts the eye automatically executing a deflecting movement, if the patient is lifted or raises his head. At the same time, the deflecting movement is advantageously realized such that the optical quality of the treatment during such deflection remains unchanged, if possible. Moreover, it is ensured by corresponding sensors and control mechanisms that a movement leading to bruising of the eye cannot occur.
|
The invention relates to a laser treatment unit for performing eye surgery, comprising a contact glass ( 23 ), which can be placed onto the eye ( 21 ) and via which a treatment laser beam ( 2 ) passes. A safety mechanism ( 24, 25 ) is provided that displaceably holds the contact glass ( 23 ) in such a manner that the contact glass retreats when the contact glass ( 23 ) is subjected to the action of a force contrary to the direction of incidence of the laser beam. The safety mechanism ( 24, 25 ) enables this retreating when a force is greater than a force limit value (Fmin) and holds the contact glass ( 23 ) in a fixed manner when the force is less than the force limit value.
| 0
|
TECHNICAL FIELD
The present invention relates generally to a butterfly-type check valve. More specifically, the invention relates to a butterfly-type check valve which is operative to effect translational movement of the valve plate relative to a pivot axis and incident to rotational movement of the plate.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 2,641,485 discloses a valved pipe fitting comprising a rotationally-based valve plate 60. The valve plate 60 has lugs 64 through which apertures 66 are formed. The plate is biased by a coil spring having outwardly projecting arm portions 68,70 which engage the apertures 66 so that the coil spring also serves as a pivot element for the valve plate. The coil spring in said to operate in two modes, either biasing the valve plate 60 to a closed position or maintaining the same in a fully open position.
To applicant's knowledge, the only reference that discloses a check valve of the above description is U.S. Pat. No. 4,964,422 Ball et al.
This invention addresses two concerns presented by the structure illustrated in the '422 patent. The first concern is that the rack and pinion arrangement disclosed therein raises the potential for mechanical binding. The second concern is that the use of a pilot valve may be undesirable in many applications for two reasons. The first reason is that in applications which do not permit leakage, a sealing arrangement must be provided for the pilot valve as well as the main valve. The second reason is that in applications characterized by high back-pressure, the pilot valve may (depending on its design and composition) be closed violently, thus presenting the additional concerns of wear, damage, and noise.
SUMMARY OF THE INVENTION
The invention is a butterfly-type check valve wherein the valve plate moves translationally relative to a pivot axis and incident to its own rotational movement. The invention employs biasing means for initiating movement of the valve plate when the latter is at a closed rotational position, thereby eliminating the need for a pilot valve.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally cross-sectional and partially elevational view of a butterfly-type check valve, taken along broken line 1--1 of FIG. 2.
FIG. 2 is a partially cross-sectional and partially elevational view taken along line 2--2 of FIG. 1.
FIG. 3 is a partially cross-sectional and partially elevational view taken along line 3--3 of FIG. 1.
FIG. 4 is a perspective view of a trunnion member and an operatively associated rod.
FIGS. 5 and 6 are partial cross-sectional views illustrating a circumferential sealing arrangement.
FIG. 7 is a schematic view of a butterfly-type check valve. The drawing includes vectors to illustrate the use of a biasing mechanism to effect initial opening of the valve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 of the drawings, a mounting body or flow body 10 defines a flow path 12 extending therethrough. Arrow 14 indicates the direction of desired flow, whereas arrow 16 indicates the direction of checked pressure. A valve plate assembly is formed by a valve plate 18 and two guide rods 20, 22. The rods, which can be hollow rather than solid, have flattened ends as indicated in FIG. 4, and are rigidly secured to the valve plate 18 by bolts 24 extending through each end and into tapped bores formed in the plate. The valve plate 18 has first recesses 26 providing lands for the rods 20, 22, a second recess 28 providing clearance for two trunnion members (hereinafter "trunnions") 30, 32, and two deeper recesses 34, 36 providing clearance for two link members 38, 40 (hereinafter, "links"). Each of the rods 20, 22 extends through an operatively associated one of the trunnions 30, 32. Cylindrical bearings (as at 42) are provided to facilitate sliding movement of the rods relative to the trunnions. The trunnions (as at 30) have first and second transverse cylindrical portions 44, 46, and the first portion has a bore 48 (FIG. 4) formed therethrough to receive the associated bearing 42 and rod 20. Each end of each second cylindrical portion 46 (FIG. is pressed into the inner race of an operatively associated bearing (as at 50).
Referring now to FIG. 3, the outer race of each bearing 50 is pressed into an operatively associated one of three support members 52, 54, 56. The center support member 54 has a generally tubular portion 58 and a bent cylindrical portion 60, the tubular portion having an inner annular boss 62 (FIG. 2) which serves as a spacer for its operatively associated bearings 50 and trunnions 30, 32. The outer support members 52, 56 are bent cyclinders having transverse bores 64, 66 formed therein to receive respective bearings 50 and trunnion portions 46 from the inward-facing side, and pins (as at 68) from the outward-facing side. The longitudinal axes of the pins 68 are aligned with the pivot axis 90, as determined in the direction indicated by the arrow 86, which should be viewed as extending into the sheet of the drawing at an angle of about four degrees.
Referring again to FIGS. 1 and 2, the pins 68 extend from the links 38, 40. An additional pair of pins (as at 70) extend from the links and are pressed into bores (as at 72) formed in the valve plate 18. When the valve plate 18 is at the closed rotational position, the longitudinal axes of the pins 70 are aligned with the pivot axis 90, as determined in the direction indicated by the arrow 84. The bores 72 extend into a wall 74 formed incident to the formation of the second recess 28. Needle bearings (not shown) are provided between the links and pins.
Referring back to FIG. 3, the above-described assembly is positioned in the flow path 12 and supported by fourth and fifth support members 76, 78 (FIG. 3). The latter support members extend through bores formed through the flow body 10 and the remaining support members 52, 54, 56, as indicated. The ends of the fourth and fifth support members project from the flow body 10 and are threaded to receive nuts (as at 80), or are otherwise rigidly secured to the flow body. These support members 76, 78, or their equivalent, extend across the flow path 12 at an angle 82 of about four degrees from a line 84 perpendicular to the longitudinal direction 86 of the path. This offset geometry is a known expedient for preventing interference between the circumferential edge of the valve plate 18 and the inner, circular-cylindrical surface 88 (FIG. 1) of the flow body. It should also assist in permitting a limited range of translational movement of the plate relative to the pivot axis 90 (FIG. 4), although selective shaping of the inner surface 88 may still be needed to accommodate the required range of translational movement, especially in applications which demand a complete seal at the closed position of the plate 18.
The support members 52, 54, 56, 76, 78 collectively form a support assembly, the purpose of which is to properly orient and support the valve plate 18 for pivotal movement in the flow path 12. Accordingly, the fourth and fifth support members 76, 78 are provided to secure the remainder of the support assembly to the flow body 10 while preventing movement of the support assembly. Rotational movement of the entire support assembly is prevented by providing both of the fourth and fifth members 76, 78. However, it is clear that only one such member is needed, provided that rotational movement of the same about its own longitudinal axis is prevented. For example, a single member of square cross-section would suffice. As illustrated, the support members 52, 54, 56, 76, 78 are suitably bored and tapped to accommodate intersecurement by bolts (as at 92).
FIGS. 5 and 6 illustrate the currently preferred sealing arrangement. The valve plate 18 has two annular recesses 94, 95 formed in its circumferential edge. An annular V-seal 96 (obtainable from such sources as Furon of Los Alamitos, Calif.) is retained on the recess 94 by a retainer 97 which in turn is retained on the angled second recess 95 by shrinkage. One leg 98 of the V-seal is entrapped. The other leg 100 is flexible about the apex of the seal, and is normally in the position illustrated in FIG. 5. Accordingly, the leg 100 has negative resistance to pressure exerted in the direction 14 of desired flow if the seal is positioned as illustrated in FIG. 6. However, as the valve plate 18 returns to its closed position in response to back-pressure, the leg 100 is flexed in a radially outward direction, and is pressed against the inner surface 88 (FIG. 1) by the checked pressure 16.
Returning to FIG. 1, a piston housing member 102 having an arcuate bottom surface (not shown) conformal with the inner surface 88 of the flow body 10 is rigidly secured to the latter at a bottom-centered position. A piston 104 is slidably disposed in a bore 106 formed in the housing member, and a spring 108 is secured to and interposed in compression between the piston and the bottom of the bore. The spring 108 is maximally compressed when the valve plate 18 is at the illustrated closed position. (NOTE: Although the drawings indicate that the plate is oriented at zero degrees relative to the axis 84 shown in FIG. 3, that angle is not quite reached at the closed position).
Referring now to the schematic drawing of FIG. 7, arrows 110, 112, 114 are force vectors representing the center of unchecked pressure, the center of checked pressure, and the biasing force exerted by the piston 104, respectively, when the valve plate 18 is at the closed position. The pivot axis 90 is centered in the flow path, and at the closed position the valve plate 18 does not quite reach the zero angle, as noted above. Accordingly, when the valve 8 is checking, the force 112 is exerted at a point just below the pivot axis. Although this force 112 is relatively large compared to the biasing force 114, its associated moment arm is relatively small and the forces 112 and 114 balance or, with the presence of the seal 96, the sum of the associated friction force and the biasing force 114 balance the checking force 112. The force 110 is absent when the valve 8 is checking. When pressure is reversed, the force 112 is absent and the force 110, also exerted just below the pivot axis 90, cooperates with the biasing force 114 so that the plate 18 pivots to an open position.
It will be understood that numerous structural equivalents could be used in place of the illustrated piston/spring arrangement. A rotationally-biased traction wheel mounted on and carried with the valve plate 18 should be workable, for example.
Referring now to FIGS. 1, 2, 3, and 7, when the valve plate 18 opens it rotates in the direction indicated by the arrow 118.
Rotational torque is transmitted through the rods 20, 22 to the bearings 42 and trunnions 30, 32, which rotationally move relative to the stationary support members 52, 54, 56, but which rotationally move with the valve plate 18. As the plate 18 rotates from the closed position it applies force on the links 38, 40 via the pins 70 in the direction 86. The force exerted in the direction 86 has a rotational component exerted on the pins 70 in a direction perpendicular to the longitudinal axes of the links 38, 40, and that component tends to rotate the links about the fixed longitudinal axes of the pins 68. The force exerted in the direction 86 also has a translational component that tends to move the valve plate 18 in a downward direction (as viewed in FIG. 1) parallel to the longitudinal axes of the rods 20, 22. Accordingly, as the plate 18 rotates, the links 38, 40 and pins 68, 70 cooperate with the plate and support members 52, 56 to translationally move the plate relative to the pivot axis 90, and the latter movement is guided by the trunnions 30, 32. In accord with the teaching of the above-referenced '422 patent, the translational movement increases the fluid-exerted torque on the plate, and the latter continues to translate and rotate. This movement continues until the longitudinal axes of the links 38, 40 are substantially parallel to the rods 20, 22. The movement is reversed in response to pressure associated with transitory back-flow. Note that the range of translational movement is limited to some multiple of the distance between the longitudinal axes of the pins 68, 70.
The foregoing portion of the description, which includes the accompanying drawings, is not intended to restrict the scope of the invention to the preferred embodiment thereof or to specific details ancillary to the teaching contained herein. Thus, the invention should be construed as broadly as is consistent with the following claims and their equivalents.
|
The invention is a butterfly-type check valve (8) wherein the valve plate (18) moves translationally relative to a pivot axis (90) and incident to its own rotational movement. The invention employs biasing means (102, 104, 108) for initiating movement of the valve plate when the latter is at a closed rotational position, thereby eliminating the need for a pilot valve.
| 8
|
This Application is a division of application Ser. No. 08/461,385, filed Jun. 5, 1995, now U.S. Pat. No. 5,726,181.
BACKGROUND OF THE INVENTION
1. Field of the Invention
During the past three decades it has been observed that camptothecin (CPT) and most of the highly lipophilic derivatives of camptothecin (HLCD) in their lactone form are poorly water soluble. For example, less than 5 micrograms of drug will dissolve in one milliliter of water to form a solution at a pH of 2 to 6. A range of pH from 2 to 6 maintains the dissolved camptothecin in the lactone form. Camptothecin and many of its poorly water soluble derivatives are known potent anticancer drugs, however, their very poor water solubility has prevented their use in the treatment of human cancer. The potency of these anticancer drugs was determined by their ability to inhibit in vitro and in vivo tumor cell growth. This invention solves the poor solubility problems of camptothecins and its derivatives. Thus, the purpose of this invention is to overcome the poor solubility of highly lipophilic camptothecin derivatives in their lactone form by designing novel formulations of the drug (at sufficient concentrations) which can be administered orally, topically or parenterally for the purpose of treating human patients with cancer.
2. Description of the Related Art
Introduction
A. DNA Topoisomerases
Several clinically important anticancer drugs kill tumor cells by affecting DNA topoisomerases. Topoisomerases are essential nuclear enzymes that function in DNA replication and tertiary structural modifications, such as overwinding, underwinding, and catenation, which normally arise during cellular replication, transcription, and perhaps other DNA processes. Two major topoisomerases have been identified, both of which are ubiquitous to eukaryotic cells: (1) Topoisomerase I (topo I) cleaves single stranded DNA; and (2) Topoisomerase II (topo II) cleaves double stranded DNA. Topoisomerase I is involved in DNA replication; it relieves the torsional strain introduced ahead of the moving replication fork.
Topoisomerase I, purified from human colon carcinoma cells or calf thymus, has been shown to be inhibited by camptothecin and many of its derivatives. Camptothecin, and water soluble camptothecin derivatives including CPT-11, topotecan, 9-amino camptothecin, 9-nitro camptothecin, DX8951 and 7-(4-methylpiperazinomethylene)-10,11-methylenedioxy camptothecin, 10,11-methylenedioxy camptothecin and 10,11-ethylenedioxy camptothecin have either been studied preclinically or used in clinical trials to treat certain types of human cancer. To date, there have been no clinical studies in human patients involving poorly water soluble highly lipophilic camptothecins, other than for camptothecin (in the late 1970's).
This absence of clinical use of lipophilic camptothecins has been due to the lack of pharmaceutical formulations which allow the direct administration of the poorly water soluble camptothecin lactone species to human patients with cancer. For the purpose of this invention, examples of highly lipophilic camptothecin derivatives include camptothecin, 10-hydroxy-7-ethyl camptothecin (SN38), 7-ethyl camptothecin (SN22), 10,11-methylenedioxy camptothecin, 10,11-ethylenedioxy camptothecin and other poorly water soluble derivatives of camptothecin which are active antitumor agents.
For the purpose of this invention, poorly water soluble and highly lipophilic camptothecin derivatives (referred to as "HLCD" for the purposes of this invention) are defined interchangeably as any A- and/or B-ring substituted camptothecin which have a water solubility of less than 5 micrograms per milliliter of water. Also for the purposes of the instant invention, the terms "highly lipophilic" and "poorly water soluble" are used interchangeably to describe their fundamental bioavailability and chemical behavior. Poorly water soluble camptothecin derivatives use the same mechanism to inhibit Topo I; they stabilize the covalent complex of enzyme and strand-cleaved DNA, which is an intermediate in the catalytic mechanism. These compounds have no binding affinity for topoisomerase I but do bind with measurable affinity to the enzyme-DNA complex. The stabilization of the topoisomerase I "cleavable complex" by camptothecin and its derivatives is readily reversible.
Although camptothecin and the aforementioned poorly water soluble camptothecin derivatives have no effect on topoisomerase II, these camptothecin derivatives stabilize the Topoisomerase I - DNA "cleavable complex" in a manner analogous to the way in which epipodophyllotoxin glycosides and various anthracyclines inhibit topoisomerase II.
Inhibition of topoisomerase I by camptothecin and highly lipophilic camptothecin derivatives induces protein-associated DNA single-strand breaks. Virtually all of the DNA strand breaks observed in vitro cells treated with camptothecin are protein linked. However, an increase in unexplained protein-free breaks can be detected in L1210 cells treated with camptothecin. The compounds appear to produce identical DNA cleavage patterns in end-labeled linear DNA. It has not been demonstrated that camptothecin or highly lipophilic camptothecin derivatives cleaves DNA in the absence of the topoisomerase I enzyme.
B. Activity of Highly Lipophilic Camptothecin Derivatives is Cell Cycle Specific
The activity of highly lipophilic camptothecin derivatives is cell cycle specific. The greatest quantitative biochemical effect observed in cells exposed to camptothecin and its derivatives is DNA single-strand breaks that occur during the S-phase. Because the S-phase is a relatively short phase of the cell cycle, longer or repetitive exposures to the drugs results in increased cell killing. Brief exposure of tumor cells to the drugs produces little or no cell killing, and quiescent cells are refractory. These results are likely due to two factors:
(1) The drugs inhibit topoisomerase I reversibly. Although they may produce potentially lethal modifications of the DNA structure during DNA replication, the breaks may be repaired after washout of the drug; and
(2) Cells treated with topo I inhibitors, such as camptothecins tend to stay in GO of the cell cycle until the drug is removed and the cleaved DNA is repaired. Inhibitors of these enzymes can affect many aspects of cell metabolism including replication, transcription, recombination, and chromosomal segregation.
C. Lactone Form of Highly Lipophilic Camptothecin Derivatives Increases Antitumor Activity and Reduces Water Solubility
Utilizing HPLC and NMR techniques, researchers have demonstrated that camptothecin and many of it's derivatives undergo an alkaline, pH-dependent hydrolysis of the E-ring lactone. The slow reaction kinetics allows one to assess whether both the lactone and non-lactone forms of the drug stabilizes the topoisomerase I-cleaved DNA complex. Studies indicate that only the closed lactone form of the drug helps stabilize the cleavable complex. This observation provides reasoning for the high degree of drug activity observed in solid tumor models. Tumor cells, particularly hypoxic cells prevalent in solid neoplasms, have relatively lower intracellular pH levels than normal cells. At pH levels below 7.0, the lactone E-ring form of camptothecins predominates. Thus, the inventors believe that camptothecins will be more effective at inhibiting topoisomerase I in an acidic environment than in cells having higher intracellular pH levels.
One of the objects of this invention is to provide lactone stable poorly water soluble camptothecin derivatives as the basis of the claimed subject matter. For this invention, lactone stable camptothecin derivatives are defined as poorly water soluble A- and/or B-ring substituted camptothecins which are dissolved in N-methyl-2-pyrrolidinone (referred to as "NMP") in the presence of an acid with or without additional excipients as desired. The inventors have discovered that highly lipophilic camptothecins display an unusually high degree of solubility (greater than 1.0 mg per milliliter)in N-methyl-2-pyrrolidinone (referred to as "NMP"). NMP, as a pharmaceutical excipient, is safe for human administration and has been found by the inventors to be chemically inert with respect to poorly water soluble camptothecins. The presence of an acid in the solution further stabilizes the lactone E-ring form of the HLCD; this is particularly useful when additional excipients are used and when the drug formulation is diluted with aqueous media. For the purpose of this invention, lactone stable camptothecin and highly lipophilic camptothecin are used interchangeably.
D. Camptothecin and Highly Lipophilic Camptothecins
In 1966, Wall and Wani isolated camptothecin from the plant, Camptotheca acuminata. In the early 1970's camptothecin reached Phase I and Phase II human trials and was found to have antitumor activity, but it caused unpredictable myelosuppression and hemorrhagic cystitis. It is important to note that all of these studies used sodium hydroxide formulations of camptothecin which greatly increased the water solubility of the molecule due to base mediated hydrolysis of the lactone E-ring to form the carboxylate species of camptothecin in appreciable quantities. At that time, however, it was not recognized that the lactone E-ring species of camptothecin had significantly (e.g., greater than 10 fold) greater anti-tumor activity than the carboxylate form of camptothecin. Phase II studies with sodium camptothecin were limited because patients given sodium camptothecin experienced unpredictable and severe myelosuppression, gastrointestinal toxicity, hemorrhagic cystitis, and alopecia. Clinical trials with sodium camptothecin (referred to as "SCPT" for the purposes of this invention) were eventually discontinued because of these unpredictable toxicities and the lack of consistent antitumor activity.
To demonstrate the utility and novelty of the present invention, it is useful to review the literature on human clinical trials conducted with SCPT administered parenterally to human patients with cancer. Gottlieb and coworkers (Cancer Chemotherapy Reports 54:461; 1970) reported on clinical studies with the sodium salt of camptothecin (SCPT) which were begun at the Baltimore Cancer Research Center in January 1969. In this clinical trial, SCPT was administered as a rapidly running i.v. solution over a 5-10 minute period at a concentration of 2 mg of SCPT per milliliter of saline. Doses of SCPT ranged from 0.5 to 10.0 mg/kg of actual or ideal body weight (whichever was less). These investigators reported that because hemorrhagic cystitis was noted in several of the early trials, patients receiving camptothecin sodium were well hydrated either i.v. or orally for 72 hours after drug administration. It is interesting to note that the mean urine recovery of camptothecin was 17.4% over the first 48 hours (range: 3.6-38.9%) with most of the drug excretion occurring in the initial 12 hours. When these investigators excluded the 5 patients with impaired urinary excretion, the mean urine recovery of camptothecin was 22.8%. These investigators noted that unmetabolized camptothecin in high concentrations rapidly appeared in the urine after i.v. drug administration and went further to state that this finding probably accounted for the sterile hemorrhagic cystitis noted in 3 moderately dehydrated patients. Although maintaining a copious urine outflow seemed to prevent this complication, the investigators explored various alterations in urine pH as another possible way of decreasing the risk of this debilitating type of toxicity.
Muggia et. al. (Cancer Chemotherapy Reports 56:515; 1972) reported results of a Phase I clinical trial in fifteen patients treated with SCPT at four weekly dose levels ranging from 20-67 mg/m 2 . No clinical benefit was observed in eight patients with measurable disease who were treated with the 5-day courses at dose levels associated with toxicity. The drug was administered in concentrations of 1 to 10 mg/ml and it was always administered by intravenous push. Cystitis was the most prominent non-hematologic toxic effect observed in this study. Bladder toxicity was dose limiting in three patients receiving doses of 20 to 30 mg/m 2 , and occurred in two additional patients at doses of 44 and 30 mg/m 2 . Cystitis, another toxic effect occurring frequently after treatment with SCPT, was not predicted by preclinical toxicologic studies. Their clinical experience suggested that the occurrence of cystitis may be related to the duration of the patient's exposure to the drug when administered as the carboxylate form. Camptothecin is excreted unchanged by the kidneys, although a large percentage of the drug administered cannot be accounted for in the urine and is likely conjugated in the liver to form the glucuronide and excreted via the hepatobiliary route. It is possible that relatively less drug is excreted in the urine of animals since an extremely active transport of camptothecin into bile has been demonstrated. Alternatively, these investigators postulated that the mucosa of the human bladder is more susceptible to the toxic action of camptothecin or that the effect on the human bladder is due to some unrecognized camptothecin metabolite.
Moertel and coworkers reported results of a Phase II Study of Camptothecin (NSC-100880) in the Treatment of Advanced Gastrointestinal Cancer (Cancer Chemotherapy Reports 56:95; 1972.) These investigators administered camptothecin sodium dissolved in physiologic saline at a concentration of 2 mg/ml and administered by rapid intravenous infusion over 5-10 minutes. Two schedules of administration were used in this study: (a) a single injection repeated at 3-week intervals; and (b) a 5-day course repeated ever 4 weeks. The initial dose for the single-dose method was 180 mg/m 2 . Because of toxic effects which were considered excessive by the investigators, later patients were treated at doses ranging between 90 and 120 mg/m 2 . Dosages for the 5-day course ranged between 11 and 22 mg/m 2 /day (total course, 55-110 mg/m 2 ). Diarrhea was only a problem at higher doses, but then could be quite severe to the point of fecal incontinence and persistent for as long as 4 weeks. Cystitis usually began about 7-10 days after treatment and was characterized clinically by dysuria and frequency. With more severe toxicity, gross hematuria developed. Pathologically, this was characterized by multiple necrotic ulcerations which could involve the entire urinary tract from kidney pelvis to bladder. According to these investigators, the occurrence of hemorrhagic cystitis did not preclude further treatment with camptothecin, and its severity could be titrated down by lowering the dose in subsequent courses. These investigators also reported that the more prolonged schedule produced more severe toxicity at a given total dose level, but the difference was not as great as might have been predicted by preclinical animal studies. These investigators proposed that a reasonable initial dose of SCPT is 110-120 mg/m 2 for the single-injection method or 17 mg/m 2 /day (total dose, 85 mg/m 2 ) for the 5-day course. They noted that after 2 months (8 or 9 weeks) only two of their 61 patients showed evidence of partial objective improvement, and none showed improvement at 3 months. Both patients who demonstrated an objective response at 2 months had large bowel cancer. These investigators concluded that camptothecin "is a drug of protean and unpredictable toxicity that has no clinical value in the management of gastrointestinal cancer." See Tables 1, 2, 3, and 4.
TABLE 1______________________________________Toxic Reactions: Single-Dose Administration ofSodium Camptothecin (Moertel et. al. Cancer ChemotherapyReports 56:95; 1972.)Nonhematologic Toxicity No. of patients with: No. ofDose patients(mg/m.sup.2) treated Diarrhea Cystitis______________________________________ 90 10 -- 1100 6 -- 2110 2 1 1120 7 4 2180 9 2 3______________________________________
TABLE 2______________________________________Toxic Reactions: 5 Consecutive Day Administrationof Sodium Camptothecin (Moertel et. al. Cancer ChemotherapyReports 56:95; 1972.)Nonhematologic No. of patients with: No. ofDose patients(mg/m.sup.2 × 5) treated Diarrhea Cystitis______________________________________11 2 -- 115 9 1 417 5 4 220 10 4 622 1 1 --______________________________________
TABLE 3______________________________________Relationship of Method of Administration to Cystitis(Moertel et. al. Cancer Chemotherapy Reports 56:95; 1972.)Method of administration Single dose 5-Day courseCystitis (% of 34 patients) (% of 27 patients)______________________________________ 24 48 (P < 0.05)______________________________________
TABLE 4______________________________________Objective Responses (Moertel et. al. CancerChemotherapy Reports 56:95; 1972.)Single-dose method (34 patients) Time after start of therapyObjective Responses* 3 wks 6 wks 9 wks 12 wks______________________________________Improved 4 2 2 --Stable 17 11 8 6Worse 13 21 24 28______________________________________5-Day course (27 patients) Time after start of therapyObjective Responses* 4 wks 8 wks 12 wks______________________________________Improved 1 -- --Stable 12 7 6Worse 14 20 21______________________________________ *3 patients showed 25%-50% response at 3 wks only.
Gottlieb and Luce reported the results of treatment of patients with malignant melanoma with camptothecin sodium (Cancer Chemotherapy Reports 56:103,1972). Fifteen patients with advanced malignant melanoma were treated with SCPT at doses of 90-360 mg/m 2 repeated every 2 weeks. SCPT was administered as a single rapid intravenous (i.v.) injection starting at a dose of 120 mg/m 2 repeated at 2-week intervals. The dose in subsequent courses was increased by increments of 60 mg/m 2 per dose (to a maximum of 360 mg/m 2 ) in eight patients who tolerated their initial doses with minimal toxicity. To prevent the known bladder toxicity of this drug, patients were well hydrated for 3 days after therapy. None of the patients had a 50% or greater decrease in tumor diameter. Less pronounced transient tumor regression was noted in three patients, but no clinical benefit was associated with these responses. The remaining patients had no change or progression in their disease. Toxic effects included myelosuppression (11 patients), nausea and vomiting (9 patients), alopecia (8 patients), diarrhea (3 patients), and hemorrhagic cystitis (1 patient). These investigators concluded that SCPT, at least as administered in this study, had little to offer the patient with advanced disseminated melanoma.
Creaven and co-investigators reported studies of plasma camptothecin levels during a 5 consecutive day course of treatment (Cancer Chemotherapy Reports 56:573-578, 1972). These investigators state that the toxicity of SCPT has been widely and unpredictably variable in the course of initial clinical evaluation. Severe toxic effects including cystitis occurred even though patients with obvious renal disease were excluded. In this study they investigated plasma camptothecin levels 24 hours after the administration of SCPT administered on a once daily ×5 schedule to determine whether such measurements would be of value in predicting toxicity, and observed that plasma camptothecin levels have little relation to the dose given when the dose is in the range of 6.5-20 mg/m 2 /day.
In another clinical study Muggia and co-workers reported the results of a Phase I Trial of weekly and daily treatment with SCPT (Cancer Chemotherapy Reports 56: 515-521, 1972). Fifteen patients were treated at four weekly dose levels ranging from 20 to 67 mg/m 2 of SCPT. Reversible leukopenia was the major dose-limiting toxic effect. Five-day loading courses were begun at total doses of 1.5 mg/m 2 per course because increased sensitivity to daily administration had been noted in animal studies. Leukopenia was more prolonged after daily treatment than after weekly treatment and occurred in four of six patients receiving a total dose of 100 mg/m 2 . Tolerance to 5-day courses was an unexpected clinical result. Also unpredicted by preclinical studies was human susceptibility to cystitis with either schedule of treatment. They noted clinical responses in two of ten patients in whom responses could be evaluated after weekly courses of treatment. No clinical benefit was observed in eight patients with measurable disease who were treated with the 5-day courses at dose levels associated with toxicity. Cystitis was another toxic effect occurring frequently after treatment with SCPT, and this toxicity was not predicted by preclinical toxicologic studies. The investigators suggested that the occurrence of cystitis may be related to the duration of the patient's exposure to the drug, and proposed that camptothecin is excreted unchanged by the kidneys, although a large percentage of the drug administered cannot be accounted for in the urine. They also proposed from this study that it is possible that relatively less drug is excreted in the urine of animals since an extremely active transport of camptothecin into bile had been demonstrated. They also postulated that the mucosa of the human bladder is more susceptible to the toxic action of camptothecin or that the effect on the human bladder is due to some unrecognized camptothecin metabolite.
There are several features which are common in these earlier clinical studies with SCPT. First is the use of SCPT ("SCPT") which made the camptothecin more water soluble. Hydrolysis of the lactone E-ring to form the water soluble carboxylate species was accomplished by formulating camptothecin in sodium hydroxide. The antitumor activity of the carboxylate form of camptothecin is reduced by at least 10-fold, which partially accounts for the lack of clinical response in these studies. Second is the rapid intravenous administration of the drug. Camptothecin is an S-phase specific drug and therefore will exert a greater antitumor effect under conditions of prolonged or repetitive exposure, as in a continuous intravenous infusion or repetitive daily dosing. The short infusion (i.v. push or rapid i.v. infusion) times in all of these earlier studies do not allow a long enough exposure time to the drug to attain suitable plasma drug levels, and is further compounded by the administration of the water soluble carboxylate form of camptothecin. A third common feature is the notable frequency of cystitis in these studies using water soluble SCPT.
The novel features of the present invention includes the following: (1) pharmaceutically acceptable formulations which allow direct parenteral administration of lactone stable highly lipophilic camptothecin derivatives to human patients with cancer (referred to as "HLCD"); (2) pharmaceutically acceptable formulations which allow the direct oral administration of lactone stable HLCD to human patients with cancer. The inventors predict that by administering the carboxylate species of HLCD a higher incidence of renal toxicity is likely to be observed than if the lactone species of HLCD is administered to patients.
The inventors maintain that the previous use of SCPT caused hemorrhagic cystitis relates to the enhanced renal excretion of the carboxylate form of camptothecin which when exposed to the lower pH (˜pH 6 or less) of the distal convoluted tubule and collecting duct in the kidney, as significant proportions of the carboxylate form of camptothecin is converted into the lactone form. The formation of the lactone species in high concentration at the distal convoluted tubule and collecting duct resulted in a high concentration of the lactone form of camptothecin being excreted and damaging the uroepithelium which resulted in hemorrhagic cystitis. Elimination of a greater concentration of the lactone form of camptothecin by the renal route is enhanced by administration of the water soluble carboxylate form and is greatly reduced by administration of the lactone form of the drug. Thus, additional significant utilities of the present invention are that the administration of HLCD substantially in the lactone form orally or parenterally to cancer patients will significantly reduce the renal elimination of HLCD and further that the incidence of hemorrhagic cystitis will be significantly reduced in patients who receive the formulations of HLCD claimed in this invention.
In addition to the previously noted toxicities and limited clinical responses to camptothecin, HLCD have also been considered unsuitable for clinical use because they are all poorly soluble in water (e.g. less than 5 micrograms of HLCD per milliliter of water). The poor water solubility of HLCD requires the use of large volumes of water-based parenteral vehicle, which results in administering the drug for a prolonged period of time and causes inconvenience and discomfort to patients. Also, administering the drug for prolonged period of time increases the costs associated with treatment of patients. Hence, an HLCD formulation which permits higher concentrations of the active drug in the infusion after dilution with a suitable parenteral vehicle is desired. Also desired is that the drug remains in the diluted solution for sufficient amount of time to be effective. Such an infusion solution will be greatly beneficial to patients, by bringing down the time required for administering useful amounts of drug and also the costs associated with administering the drug for a more prolonged period of time.
One highly useful purpose of this invention is to formulate the HLCD in a pharmaceutically acceptable manner using an organic or a mixture of organic co-solvents with a high degree of physiologic safety to dissolve the HLCD in desirable concentrations and concurrently stabilize HLCD in the lactone E-ring form. It is this formulation invention which permits direct administration of HLCD to human patients with cancer.
The inventors believe that direct administration of a lactone stable HLCD to human patients has another important utility for treating patients with cancer. It is well known that cell membranes are comprised largely of lipid, and that lipid soluble drugs in general have superior ability to penetrate hydrophobic cellular membranes relative to water soluble drugs. HLCD are poorly water soluble and are therefore lipid soluble which facilitates their penetration into various body tissues and will improve the bioavailability and anticancer activity of the drug. The anticancer activity of the camptothecins in general is closely linked with their ability to inhibit the intracellular Topoisomerase I which is concentrated within the nucleus of the cell. The inventors contend that the present invention increases the amount of HLCD drug diffusion through the cellular and nuclear membranes in tumor cells and will result in superior antitumor activity of the drug. Water soluble camptothecin derivatives are predicted to have a lesser ability to diffuse through the cellular and nuclear membranes in the body.
The utility of suitable organic solvents for this invention involving pharmaceutical dosage forms of HLCD is restricted to those which have a high degree of physiological safety in humans. This invention teaches new methods for making pharmaceutical formulations for a variety of lactone stable HLCD with water solubility of 5 micrograms per milliliter or less. Some examples of poorly water soluble camptothecins (HLCD) include 10,11-methylenedioxy camptothecin, 10,11-ethylenedioxy camptothecin, 7-ethyl camptothecin(SN22), 7-ethyl-10-hydroxy camptothecin (SN38) and congeners thereof. Any poorly water soluble camptothecin with a solubility of 5 micrograms per milliliter of water or less may be dissolved or suspended in these novel formulations and will have appreciable quantities (greater than 90%) of the lactone form of drug in the resulting solution. 10,11-Methylenedioxy camptothecin, 10,11-ethylenedioxy-camptothecin, 7-ethyl camptothecin, and 7-ethyl-10-hydroxy camptothecin and congeners thereof are reportedly very active in preclinical studies, but they are also reported to be poorly soluble in water (less than 5 micrograms of drug will dissolve in one milliliter of water) which limits their utility because of the inability to readily administer these drugs to human patients with cancer (Pommier, et al. 1992, Wall et. al. 1994).
One of the advantages of the instant invention is that the instant formulations provide clinicians with the ability to directly adjust the plasma levels of HLCD to the point of therapeutic tolerance by controlling the dose and the schedule of drug administration. The inventors contend that this should lead to a superior ability to achieve more effective antitumor activity and reduced interpatient variability of the plasma levels of HLCD.
The different observations made in these studies suggest that direct administration of HLCD by parenteral and oral administration could provide significant clinical benefit for patients undergoing treatment for cancer. However, in the past, HLCD have been considered insufficiently water soluble for clinical use. The current invention overcomes the solubility problem by providing lactone stable pharmaceutically acceptable formulations of HLCD which upon dilution with an acceptable parenteral vehicle gives a stable solution of useful concentrations of HLCD for parenteral use and also a concentrated solution or suspension of HLCD suitable for encapsulation within a gelatin capsule for oral HLCD formulations.
SUMMARY OF THE INVENTION
This invention involves the pharmaceutical formulation of lactone stable highly lipophilic camptothecin derivatives ("HLCD") to treat cancer in humans. Also within the scope of the present invention is a stable HLCD solution or suspension in NMP (1-Methyl-2-Pyrrolidinone, defined above) which, upon dilution with suitable parenteral vehicle, provides a final infusion containing a HLCD activity in the range of about 0.001 mg to about 1.0 mg per ml. The present invention also relates to a highly concentrated solution or suspension of HLCD in the range of about 1.0 mg to about 40.0 mg per ml in NMP suitable for encapsulation within a gelatin capsule. For the purposes of this invention, lactone stable HLCD is defined as any A- and/or B-ring substituted camptothecin derivative (HLCD) having a water solubility of less than 5 micrograms per milliliter of water in the lactone form.
For the purpose of this invention, a highly lipophilic camptothecin derivative ("HLCD"), having a water solubility of 5 micrograms per milliliter or less, has the general structural formula: ##STR1## wherein R 1 , R 2 , R 3 , R 4 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 1 and R 2 together may represent --X l --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 ; and wherein R 5 , R 6 , R 7 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 2 and R 3 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 ; and wherein R 5 , R 6 , R 7 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 3 and R 4 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 7 , O, S or NR 7 ; and wherein R 5 , R 6 , R 6 =H lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, cyano group;
Another embodiment of this invention is an injectable, sterile solution comprising N-methyl-2-pyrrolidinone and a highly lipophilic camptothecin derivative ("HLCD") having a water solubility of 5 micrograms per milliliter or less, with the general structural formula: ##STR2## wherein R 1 , R 2 , R 3 , R 4 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 1 and R 2 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R 5 , R 6 , or R 7 =H lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 2 and R 3 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R 5 , R 6 , or R 7 =H lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group; and
wherein R 3 and R 4 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R 5 , R 6 , or R 7 =H lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group.
A further embodiment of this invention is a pharmaceutically acceptable acid selected from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, hydrochloric acid, phosphoric acid, gluconic acid, lactic acid, and hydrochloric acid may also be added to the above defined injectable sterile solution. For the purposes of this invention, a pharmaceutically acceptable acid is defined as an acid selected from the group consisting of, but not limited to, acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, hydrochloric acid, phosphoric acid, gluconic acid, lactic acid, and hydrochloric acid.
Additionally, the above injectable sterile solution may also include one or more excipients including, for example, but not limiting to, ethanol, benzyl alcohol, glycerin, polaxomer, PEG-300, PEG-400, Tween-80, Cremaphor or taurocholic acid or a pharmaceutically acceptable salt thereof.
For the purpose of this invention, one of ordinary skill in this art would know that the A-ring is the first ring on the left side of the above chemical structure and that the B-ring is the second from the left ring of the above structure. Additionally, one of ordinary skill in this art knows that R-1 in the above chemical structure is also defined as position 7 of the B-ring. R-2 in the above chemical structure is also defined as position 9 of the A-ring. R-3 in the above chemical structure is also defined as position 10 of the A-ring and R-4 in the above chemical structure is also defined as position 11 of the A-ring.
Another embodiment of this invention is substitutions in only the A-ring of the above structure only, substitutions in only the B-ring only and also substitutions in both the A-ring and the B-ring. Examples of HLCD A-ring substituted camptothecin derivative include, but are not limited to, substitutions at positions 9, 10, or 11 and combinations thereof. For example, A-ring substitutions could be at position 9 only, at position 10 only, at position 11 only, as well as A-ring substitutions at positions 9 and 10, at positions 9 and 11, and at positions 9, 10, and 11. Additionally, B-ring substituted camptothecin derivatives include, but are not limited to, substitutions at position 7. This invention also embodies substitutions in both the A-ring and in the B-ring. For example, this invention includes substitutions at positions 7 and 9, at positions 7 and 10, at positions 7 and 11, at positions 7, 9, 10, and 11 and at positions 7, 10, and 11. The above substitutions are examples only and do not intend to limit the instant invention to the substitutions listed.
Examples of HLCD (any A- and/or B-ring substituted camptothecin derivative) as defined in the instant invention include, without restriction or limitation, 10,11-methylenedioxy camptothecin, 10,11-ethylenedioxy camptothecin, 7-ethyl camptothecin, 7-ethyl-10-hydroxy camptothecin, 9-methyl camptothecin, 9-chloro-10,11-methylenedioxy camptothecin, 9-chloro camptothecin, 10-hydroxy camptothecin, 9,10-dichloro camptothecin, 10-bromo camptothecin, 10-chloro camptothecin, 9-fluoro camptothecin, 10-methyl camptothecin, 10-fluoro camptothecin, 9-methoxy camptothecin, and 11-fluoro camptothecin.
Direct administration of HLCD to human patients with cancer is likely to offer several important clinical advantages over administration of more water soluble camptothecin derivatives such as SCPT, CPT-11, topotecan, 9-amino camptothecin, 9-nitro camptothecin and 7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy camptothecin.
For example
(1) direct administration of HLCD allows the clinician to tailor the administration of the active cytoxic species (lactone stable form of HLCD) to suit the patient's tolerance;
(2) direct administration of HLCD overcomes interpatient variability which may be due to polymorphism of key enzyme(s) in the metabolism of CPT-11 to 7-ethyl-10-hydroxy camptothecin;
(3) clinicians can more consistently optimize the drug dosage and schedule to achieve the maximum tolerated dose of HLCD which is likely to lead to the most beneficial clinical anti-cancer effect; and
(4) direct administration of an HLCD in the lactone form will have a generally superior ability to penetrate tissue than the direct administration of water soluble camptothecin derivatives in the lactone stable or carboxylate forms.
Regarding the clinical utility of lactone stable pharmaceutical formulations of HLCD for the treatment of human cancer, this invention provides the following:
(1) solutions and suspensions comprising lactone stable HLCD;
(2) formulations of lactone stable HLCD suitable for parenteral administration;
(3) oral formulations of lactone stable HLCD; and
(4) use of formulations of HLCD for the treatment of localized complications of cancer by direct administration via instillation into various body cavities.
HLCD Dissolved or Suspended in N-Methyl-2-Pyrrolidinone With or Without Additional Excipients
Another embodiment of the claimed invention is a highly lipophilic camptothecin derivative (HLCD) solution or suspension containing HLCD and N-methyl-2-pyrrolidinone ("NMP"). Yet another embodiment of the claimed invention is a highly lipophilic camptothecin derivative (HLCD) solution or suspension containing HLCD, N-methyl-2-pyrrolidinone ("NMP") and a pharmaceutically acceptable acid.
There are many pharmaceutically acceptable acids for this invention, but the inventors prefer to select one from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, hydrochloric acid, phosphoric acid, gluconic acid, lactic acid, and hydrochloric acid.
Taurocholic acid, a bile acid with very weak acidic properties may be used for certain oral formulations if desired, and is not incorporated in any formulation for the purpose of lowering the pH of the formulation. Also for the purposes of this invention, the term "pharmaceutically acceptable" is defined as a reference to the high degree of physiologic safety of the liquid organic excipients contained within the undiluted formulations when administered to human patients in the amounts contained within a range of 1 to 50 milliliter volumes administered to humans patients for one to five consecutive days.
One of the key discoveries in the present invention is the unexpectedly high solubility of HLCD in N-methyl-2-pyrrolidinone (NMP). N-Methyl-2-pyrrolidinone is an organic liquid excipient and is also known as 1-methylpyrrolidinone, N-methyl-2-pyrrolidinone, 1-methyl-5-pyrrolidinone, methylpyrrolidinone, N-methyl pyrrolidinone, methylpyrrolidinone, N-methylpyrrolidone, N-methyl-2-pyrrolidone, M-pyrol, and NMP.
NMP exhibits a high degree of physiologic safety in mammals with the following LD50 values: (rat) oral--7000 mg/kg, intraperitoneal--2472 mg/kg, intravenous--2266 mg/kg, (mice) oral--7725 mg/kg, intraperitoneal--4429 mg/kg, intravenous--3605 mg/kg, (rabbit) skin--8000 mg/kg (Registry of Toxic Effects of Chemical Substances, 1983-84 Supplement, Page 1628). NMP has been used to formulate etoposide (Etoposide, U.S. Pat. No. 4,772,589) and acridine derivatives (M-AMSA, U.S. Pat. No. 5,034,397). Etoposide and acridine derivatives (1) are anticancer drugs; (2) are chemically unrelated to HLCD; (3) are more water soluble than HLCD; and (4) exert their antitumor effects by vastly different mechanisms than HLCD.
NMP has also been used for oral formulations of the antibiotic clarithromycin (Clarithromycin, WO patent #9,014,094) and other drugs. NMP is a key excipient of the instant invention which allows an exceptionally high degree of drug solubility of HLCD (range 1 mg/ml to 40 mg/ml) in NMP as a solution or suspension. An HLCD solution comprising NMP with or without other combinations of excipients described herein, which can be diluted with a parenteral vehicle such as sterile injectable water USP, 5% Dextrose solution for injection USP or 0.9% sodium chloride solution for injection USP, such that the amount of HLCD dissolved in the diluted infusion is from about 0.001 mg/ml to about 1.0 mg/ml, is taught in the present invention. The inventors have discovered that HLCD show remarkably high solubility in NMP compared to other common pharmaceutical solvents such as water, ethanol, benzyl alcohol, propylene glycol, PEG 300, PEG 400, dimethylisosorbide or dimethylacetamide (Table 5). This high solubility of HLCD in NMP makes NMP a unique and highly useful pharmaceutical solvent for making useful solutions or suspensions of HLCD.
TABLE 5______________________________________Solubility of Camptothecin in Various SolventsSolvent Concentration, mg/ml______________________________________Milli-Q Water 0.0002Ethanol 0.051Benzyl alcohol 1.674Propylene glycol 0.281PEG 300 0.706Dimethylisosorbide 0.928Dimethylacetamide 5.000N-Methyl-2-pyrrolidinone (NMP) >15.000 (range 15-20)______________________________________
NMP is inert with respect to undesirable chemical reactions with HLCD and is therefore a highly useful excipient to create solutions of HLCD in the lactone form. Further utility of NMP in the present invention is the discovery that NMP allows the introduction of additional excipients which further improve the overall utility of the HLCD dissolved in the NMP solution in a manner which are of additional benefit for parenteral or oral administration to human patients with cancer. The HLCD solution or suspension is prepared by mixing the desired components with NMP and adding a pharmaceutically acceptable acid to adjust the pH to 3-5.
A pharmaceutically acceptable acid is preferably included in the NMP solutions and suspensions of the present invention. Any pharmaceutically acceptable acid may be used; for example mineral acids such as hydrochloric acid or phosphoric acid; and carboxylic acids such as tartaric, lactic, ascorbic, gluconic, citric, succinic, fumaric, or maleic acids. Hydrochloric acid, phosphoric acid and carboxylic acids are the most preferred for the novel oral and parenteral formulations described in the present invention. The amount of acid used may be from about 100 to about 5000 parts by weight of acid per part by weight of HLCD and preferably from about 1000 to 2500 parts by weight of acid per part by weight of HLCD. Citric acid is preferably used in a proportion of from about 1000 to about 2000 parts by weight. Oral formulations of NMP and HLCD can additionally contain taurocholic acid. The NMP HLCD solution is miscible with ethanol, benzyl alcohol, polysorbate-80 (Tween-80), polyethylene glycol (PEG), polyoxyethylated castor oil, propylene glycol, isopropyl myristate, corn oil, cottonseed oil, and the like.
An object of the present invention is to provide a solution or suspension of HLCD in the lactone form in NMP. A more concentrated HLCD-NMP solution or suspension (10 mg or more per milliliter of solution or suspension) is particularly useful as a filling solution or suspension for gelatin capsules. A HLCD-NMP solution may also be formulated for parenteral administration providing a useful and practical means to dissolve the drug.
The present invention is prepared by mixing HLCD in NMP alone or by subsequent addition of additional excipients including or excluding any combination the following: (a) a carboxylic acid and/or mineral acid, (b) polyethylene glycol (PEG-300 and/or PEG-400), (c) alcohol (ethyl and/or benzyl alcohol) (d) polysorbate-80 (Tween-80) and (e) taurocholic acid. The amount of HLCD contained in the solution or suspension described in this invention is not specifically restricted but may be any amount convenient for pharmaceutical purposes, and may be selected according to the dosage to be prepared. A preferred capsule filling solution or suspension contains from about 1 mg to about 40 mg of HLCD activity per ml of solution or suspension.
Another preferred embodiment of the claimed invention is an HLCD solution or suspension prepared by dissolving or suspending the desired components in NMP in the presence of a pharmaceutically acceptable acid.
In the formulations provided by the instant invention, the HLCD is soluble or suspended and maintained in its active lactone form. The non-enzymatic conversion of the pH labile E-ring from the closed lactone (active) to the open carboxylate form (inactive) is reduced by formulating HLCD under acidic pH conditions (pH range of 3 to 5). Thus, an acid is included by the inventors to assure that an acidic pH value is maintained upon dilution to form a micellar solution or suspension. Examples of preferred carboxylic acids effective in this invention include citric, gluconic, lactic, maleic, tartaric, or ascorbic acids. Other acids such as hydrochloric acid and phosphoric acid can be employed instead or in addition to citric acid to form the most preferred solution.
Yet another embodiment of the claimed invention is that the solution or suspension of HLCD contains from about 1.0 mg to about 40.0 mg activity of HLCD per ml of solution or suspension. This concentration of HLCD in the resulting formulation solution or suspension would be useful and effective for both oral and parenteral administration of the HLCD to human patients with cancer.
When oral dosages are to be administered in a capsule form, it is advantageous to have a concentrated solution or suspension of HLCD suitable for encapsulation within a soft or hard gelatin capsule. Concentrated solutions or suspensions allow the preparation of capsules of smaller size which allows easier ingestion by the patient, and may also reduce the number of capsules to be swallowed. These factors are important in view of the generally poor condition of cancer patients.
Taurocholic acid, a bile acid, may enhance in the intestinal absorption of the drug in certain patients. The present invention takes advantage of the discovery that taurocholic acid, or a pharmaceutically acceptable salt thereof, when included with HLCD in a solution or suspension dosage composition, results in improved absorption of the drug following oral ingestion of the composition. It is believed that this is due to the formation of a micellar solution of HLCD on dilution thereof with the gastric contents.
The phenomenon of micellar solubilization of poorly water-soluble drugs mediated by bile acids, including taurocholic acid, has been previously reported with respect to glutethimide, hexesterol, griseofulvin (Bates et al.), reserpine (Malone et al.) and fatty acids and cholesterol (Westergaard et al.). The use of taurocholic acid or a pharmaceutically acceptable salt thereof in the present invention involves a pharmaceutical solution of HLCD which has the useful property of providing a stable apparent solution of the drug upon dilution thereof with from 1 to 100 volumes of water. The solution is stable and free of precipitate for a period of at least two hours; sufficient time to permit administration and absorption by the patient.
It has been observed with similar solutions of etoposide, which is a chemically different anticancer drug, that the bioavailability of the drug following oral administration is substantially equivalent to that achieved by intravenous administration of a solution of the chemically unrelated anticancer drug etoposide (U.S. Pat. No. 4,713,246). Analogous to that of etoposide, it is believed that ingestion of the present dosage form of HLCD and resulting dilution thereof by the stomach contents, results in the formation of a micellar solution of HLCD in the stomach which is readily absorbed by the gastrointestinal tract. However, the Applicants do not wish to be bound by any theoretical explanation of the mechanism by which the superior oral bioavailability of the present HLCD formulation is achieved.
Antitumor Compositions Comprising HLCD
Yet another preferred embodiment of the claimed invention is an antitumor composition comprising a solution or suspension of a HLCD dissolved or suspended in NMP or NMP containing from about 1.0 mg to about 40.0 mg HLCD activity per milliliter of solution or suspension and containing from about 100 to about 5000 parts of a pharmaceutically acceptable carboxylic acid or hydrochloric acid, or phosphoric acid per part by weight of HLCD. The inventors prefer to use 1000 to 2000 parts by weight of a pharmaceutically acceptable carboxylic acid and/or mineral acid per part by weight of HLCD. For the purpose of this invention, examples of carboxylic acid that can be used in this invention are tartaric, lactic, ascorbic, gluconic, citric, succinic, fumaric, or maleic acids and examples of mineral acids useful in this invention are hydrochloric acid or phosphoric acid.
Another embodiment of this invention is an antitumor composition comprising of a solution or suspension of HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises polyethylene glycol.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises polyethylene glycol and ethyl alcohol or benzyl alcohol or the solution or suspension further comprises ethyl alcohol and benzyl alcohol.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises polyethylene glycol, and polysorbate-80.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises polyethylene glycol, ethyl alcohol or benzyl alcohol (or ethyl alcohol and benzyl alcohol) and polysorbate-80.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises polyethylene glycol, polysorbate-80 and taurocholic acid or a pharmaceutically acceptable salt thereof.
Yet another embodiment of this invention is wherein the solution or suspension of antitumor composition contains for each part by weight of HLCD, 1,000-10,000 parts by weight of NMP, 100-5,000 parts by weight of a pharmaceutically acceptable acid, 1-10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof, 1,000-10,000 parts by weight of polyethylene glycol (PEG-300 and/or PEG-400). An additional embodiment is wherein said acid is an carboxylic acid and the inventors prefer citric acid.
Another embodiment of the claimed invention is the antitumor composition further comprising a lower alcohol. Many different alcohols would be effective in this invention, but the inventors prefer to use ethanol or a combination of ethanol and benzyl alcohol. Another embodiment of the claimed invention is an antitumor composition further comprised of glycerin as a co-solvent.
Yet another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid preferably citric acid and or hydrochloric or phosphoric acid, polyethylene glycol (PEG-300 and/or PEG-400), polysorbate-80, ethanol, and glycerin.
An additional embodiment of this invention is wherein said solution or suspension contains for each part by weight of HLCD, 1,000-10,000 parts by weight of NMP, 1,000-5,000 parts by weight of a pharmaceutically acceptable acid, 1-10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof, 1,000-10,000 parts by weight of polyethylene glycol, 0.1-2.0 parts by weight of glycerin, 1,000-5,000 parts by weight of ethanol.
Yet another embodiment of this invention is an antitumor composition comprising a solution or suspension of HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid, wherein said solution or suspension further comprises ethyl alcohol or ethyl alcohol and benzyl alcohol, and polyethylene glycol.
As a more preferred embodiment for this antitumor composition, the pharmaceutically acceptable acid is citric acid, the polyethylene glycol is PEG-400, the lower alcohol is ethanol and the surfactant is polysorbate-80.
Another embodiment of this invention, is an antitumor composition comprising a solution or suspension of about 1.0 mg to about 150.0 mg of HLCD dissolved or suspended in 1,000-10,000 parts by weight of NMP in the presence of about 100 to 5000 parts by weight of a pharmaceutically acceptable-organic carboxylic acid. This antitumor composition further comprises about 1,000-10,000 parts by weight of polyethylene glycol, about 1,000 to 5,000 parts of a pharmaceutically acceptable alcohol.
More preferred for this antitumor composition is when the acid is citric acid, the polyethylene glycol is PEG-400, the alcohol is ethanol and the surfactant is polysorbate-80.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension about 1.0 mg to about 150.0 mg of HLCD dissolved or suspended in 1,000 to 10,000 parts of NMP in the presence of 100 to 5,000 parts of a pharmaceutically acceptable carboxylic acid. This solution or suspension further comprises about 1,000 to 5,000 parts of a pharmaceutically acceptable alcohol 1,000 to 10,000 part of polyethylene glycol, and 1,000 to 10,000 parts of polysorbate-80.
More specifically for this antitumor composition, the acid is citric acid, the alcohol is ethanol, and the polyethylene glycol is PEG-400.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension of 1.0 mg to about 150.0 mg of HLCD dissolved or suspended in 1,000 to 10,000 parts of NMP, wherein this solution or suspension further comprises about 1,000 to 10,000 parts polyoxyethylated castor oil, about 1,000 to 5,000 parts by weight ethyl alcohol, and about 1,000 to 5,000 parts citric acid, 1,000 to 10,000 parts of polyethylene glycol, and 1,000 to 10,000 parts of polysorbate-80.
In a more preferred embodiment, HLCD is solubilized or suspended in a manner suitable for clinical use by forming a solution or suspension of 1.0 to 40.0 mg of HLCD per 1 ml in vehicle comprising 1,000 to 10,000 parts by weight of NMP, ethyl alcohol 1,000 to 5,000 parts by weight, benzyl alcohol-1,000 to 5,000 parts by weight, citric acid 1,000 to 5,000 parts by weight, polyethylene glycol (PEG-300 or PEG-400) 1,000 to 10,000 parts by weight, and polysorbate-80 (Tween-80) 1,000 to 10,000 parts. While either polyethylene glycol (PEG-300 or PEG-400) would be effective in this embodiment, the inventors prefer to employ PEG-400.
This preferred embodiment of a HLCD composition is summarized in Table 6 as follows:
TABLE 6______________________________________COMPONENT PARTS BY WEIGHT FORPARENTERAL OR ORAL FORMULATIONS OF HLCDIngredients Parts by Weight______________________________________HLCD 1.0 to 40.0.sup.(1) EtOH 1,000 to 5,000.sup.(1) Benzyl Alcohol 1,000 to 5,000Acid 100 to 5,000PEG 400 1,000 to 10,000NMP 1,000 to 10,000.sup.(1) Cremaphor-EL 1,000 to 10,000.sup.(2) Glycerin 0.5 to 2.5.sup.(2) Taurocholic Acid 1 to 10Polysorbate 80 1,000 to 10,000(Tween-80)______________________________________ .sup.(1) optional additions individually or in any combination to oral or parenteral HLCD formulations .sup.(2) used in oral formulations only
Another more preferred parenteral formulation comprises HLCD formulated for dilution prior to parenteral administration made of 1 to 40 mg of HLCD in 1 ml of solvents including 1,000 to 10,000 parts by weight of HLCD of Cremaphor EL (polyoxyethylated castor oil), 1,000 to 5,000 parts ethyl alcohol, NMP 1,000 to 10,000 parts, and citric acid 1,000 to 5,000 parts.
Yet another embodiment of this invention for oral administration to a patient with cancer is the HLCD dissolved or suspended in NMP in the presence of a pharmaceutically acceptable acid.
A further embodiment of this invention is the claimed composition and method of administering the composition by encapsulating the claimed formulations within a hard gelatin capsule. Yet another embodiment of the claimed composition and method of administering the composition is encapsulating the claimed formulations within a soft gelatin capsule or hard gelatin capsule. One of ordinary skill in the art will know that any of the claimed formulations adapted for oral administration can be used as the fill for the soft or hard gelatin capsule.
A more specific embodiment of the claimed invention is an oral formulation of HLCD in hard or soft gelatin capsules (comprised of gelatin/glycerin/sorbitol/purifiers) containing 1.0 to 40.0 mg of HLCD per milliliter in a solution or suspension comprising citric acid 1,000 to 5,000 parts by weight, glycerin 0.5 to 2.5 parts by weight, polyethylene glycol (molecular weight 300 to 400) 1,000 to 10,000 parts by weight, ethyl alcohol 1,000 to 5,000 parts by weight, PEG-400 1,000 to 10,000 parts by weight, polysorbate-80 1,000 to 10,000 parts by weight, and 1,000 to 10,000 parts NMP.
Another preferred oral formulation will include the addition of taurocholic acid 1 to 10 parts by weight. The soft gelatin capsules may also be composed of any of a number of compounds used for this purpose including, for example, a mixture of gelatin, glycerin, sorbitol, and parabens.
Table 7 below indicates parts by weight of different components to be included in the oral formulation to be administered in capsules. Several components are marked with an "**" which denotes that the components are "optional." For the purpose of this invention, inclusion of these components depends on a variety of different factors; i.e. type of cancer the patient has, pretreated previously, etc.
TABLE 7______________________________________COMPONENT PARTS BY WEIGHTFOR ORAL FORMULATION OF HLCDIngredients Parts by Weight______________________________________HLCD 1 to 40NMP 1,000 to 10,000Citric Acid 1,000 to 5,000EtOH 1,000 to 5,000Polysorbate-80 (Tween-80) 1,000 to 10,000PEG-400 1,000 to 10,000Glycerin ** 0.5 to 2.5Taurocholic Acid ** 1 to 10______________________________________
Clinicians will administer HLCD in these formulations to human patients with cancer according to schedules which maximize its potential antitumor effects and diminish its potential toxic side effects. Except at extremely high doses which produce high plasma concentrations of the drug, the antitumor activity of HLCD can be increased by increasing the duration of exposure (time dependent) rather than increasing the dose (dose dependent) of the drug. Increased antitumor effects associated with increasing the duration of exposure is most likely related to the predominant S-phase mode of antitumor activity of HLCD. HLCD are S-phase-active agents therefore, the greatest antitumor effect in humans will likely be observed with prolonged infusion or closely spaced repetitive administration schedules. Such schedules of administration would expose more cycling tumor cells to the drug and increase the frequency of exposure of the tumorcells in S-phase to sufficiently toxic levels of the drug.
A further embodiment of this invention is that the claimed HLCD antitumor composition can be used to treat a variety of different cancer types. The claimed formulations and compositions of this invention may be used in treatment of a number of tumors (cancers) including, without limitation, human cancers of the lung, breast, colon, prostate, melanoma, pancreas, stomach, liver, brain, kidney, uterus, cervix, ovaries, and urinary tract.
In many cases, the site and type of tumor to be treated will influence the preferred route of administration and therapeutic regimen to be applied. Consequently, although the formulations of the invention may be most usually administered by intravenous injection, infusion or orally, these formulations may also can be delivered directly into the tumor site or by other methods designed to target the drug directly to the tumor site. For example, in patients with malignant pleural effusion, the intrapleural route may be preferred; in patients with poor venous access the subcutaneous route of administration may be preferred; in patients with primary or metastatic cancer involving the brain or nervous system, the intracisternal or intrathecal route of administration may be most advantageous; in patients with malignant ascites secondary to cancer, one may select intraperitoneal administration; and in patients with bladder cancer direct intravesicular instillation may be most advantageous. Similarly, in tumors of the skin, the formulation may be topically applied. An oral formulation is also taught for use where suitable for patients taking the medication outside of the hospital or clinic.
An additional embodiment of this invention is a HLCD solution or suspension comprising HLCD dissolved or suspended in NMP, in the presence of a pharmaceutically acceptable acid and this solution or suspension is prepared for oral, intrapleural, intrathecal, subcutaneous, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer.
A further embodiment of claimed HLCD is a method of treatment of cancer in humans with convergent therapy or combination therapy. This method uses HLCD dissolved in NMP, in the presence of pharmaceutically acceptable acid and co-administers it with additional drugs selected from the group consisting of, but not limited to, carmustine, azathioprine, cis-platinum, carboplatin, iproplatin, cyclophosphamide, ifosfamide, etoposide, ara-C, doxorubicin, daunorubicin, nitrogen mustard, 5-fluorouracil, bleomycin, mitomycin-C, fluoxymesterone, mechlorethamine, teniposide, hexamethylmelamine, leucovorin, melphelan, methotrexate, mercaptopurine, mitoxantrone, BCNU, CCNU, procarbazine, vincristine, vinblastine, vindesine, thioTEPA, amsacrine, G-CSF, GM-CSF, erythropoietin, γ-methylene-10-deazaaminopterin or γ-methylene-10-ethyl-10-deazaaminopterin, taxol, and 5-azacytidine. For the purpose of this invention, the terms convergent, co-administered, and combination are used interchangeably.
HLCD dissolved or suspended in NMP with or without the described combination of other formulation excipients that have been taught in the foregoing section have additional utility when administered parenterally using a prolonged schedule of administration. To increase the utility of HLCD for parenteral infusions, the HLCD parenteral compositions may be diluted with an appropriate volume of an aqueous vehicle to a concentration of about 0.001 mg/ml to 1.0 mg/ml of HLCD activity.
A further embodiment of the claimed invention is a solution of any of the claimed HLCD compositions and formulations for administration to a patient with cancer upon dilution with a sterile aqueous parenteral vehicle. For the purposes of this invention, parenteral aqueous vehicles suitable for dilution include dextrose 5 to 10% in water, 0.9% NaCl in water with or without 5% or 10% Dextrose, 0.45% NaCl in water with or without 5% or 10% Dextrose, Lactated Ringer's Solution, 3% NaCl in water with or without 5% to 10% Dextrose, water USP for injection or sterile lipid formulations, such as intralipid, used for parenteral nutritional support for cancer patients.
This invention is also directed to a solution or suspension comprising an A-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein the substituted camptothecin is dissolved or suspended in an effective amount of N-methyl-2-pyrrolidinone. A-ring substitutions include any substitutions on the A-ring but the inventors prefer to employ substitutions at position 9, 10 or 11 of the A-ring.
This invention is also directed to a solution or suspension comprising an B-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein the substituted camptothecin is dissolved or suspended in an effective amount of N-methyl-2-pyrrolidinone. B-ring substitutions include any substitutions on the B-ring but the inventors prefer to employ substitutions at position 7 of the B-ring.
This invention is also directed to a solution or suspension comprising a substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein the camptothecin has substitutions on the A-ring and on the B-ring and wherein the substituted camptothecin is dissolved or suspended in an effective amount of N-methyl-2-pyrrolidinone. This invention includes substitutions at all possible locations on the A- and B-ring but the inventors prefer substitutions at position 7 of the B-ring and at positions 9, 10, and/or 11 of the A-ring.
This invention is also directed to a solution or suspension comprising an B-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein the substituted camptothecin is dissolved or suspended in an effective amount of N-methyl-2-pyrrolidinone.
All of the embodiments outlined below apply to A-ring substituted camptothecins, B-ring substituted camptothecins and to substituted camptothecins containing both A-ring and B-ring substitutions. For this invention, "dissolved" and "suspended" have regular meanings known to one of ordinary skill in this art.
The above solution or suspension may further contain a pharmaceutically acceptable acid wherein this acid can be a carboxylic acid selected from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, gluconic acid, and lactic acid. The above solution or suspension may further contain a pharmaceutically acceptable acid wherein this acid can be a mineral acid selected from a group consisting of hydrochloric acid and phosphoric acid. Additionally, the pharmaceutically acceptable acid in the above solution or suspension may be selected from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, phosphoric acid, gluconic acid, lactic acid, and hydrochloric acid. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension may further contain a lower alcohol selected from the group consisting of ethanol and benzyl alcohol. The above solution or suspension may also contain a polyethylene glycol selected from a group consisting of PEG-300 and PEG-400. And the above solution or suspension may further contain a non-ionic surfactant. The inventors prefer to employ polysorbate-80 (Tween-80) but most surfactants are suitable. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone may also further contain a polyethylene glycol and a non-ionic surfactant. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
The above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone may also contain a lower alcohol, polyethylene glycol and a non-ionic surfactant. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Yet another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and lower alcohol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Yet another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and polyethylene glycol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and non-ionic surfactant may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, polyethylene glycol and non-ionic surfactant may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, polyethylene glycol, non-ionic surfactant and lower alcohol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above solution or suspension comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone wherein this solution or suspension contains from about 1.0 mg to about 40.0 mg activity per ml of solution or suspension of the substituted camptothecin having a water solubility of less than 5 micrograms per ml of water. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Yet another embodiment of this invention is an antitumor composition comprising a solution or suspension containing an A-ring substituted camptothecin or containing a B-ring substituted camptothecin or containing both an A-ring substituted and a B-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter dissolved or suspended in N-methyl-2-pyrrolidinone wherein said composition contains from about 1 mg to about 40 mg camptothecin activity per ml and contains about 1,000 to 10,000 parts by weight of N-methyl-2-pyrrolidinone.
For this invention "substituted camptothecin" applies to substitutions in the A-ring or substitutions in the Bring or substitutions in both the A-ring and the B-ring. This invention includes substitutions at all possible locations on the A- and B-ring but the inventors prefer substitutions at position 7 of the B-ring and at positions 9, 10, and/or 11 of the A-ring.
The antitumor composition comprising a substituted camptothecin and N-methyl-2-pyrrolidinone may also contain from about 100 to about 5,000 parts by weight of a pharmaceutically acceptable acid per part by weight of the substituted camptothecin.
The antitumor composition comprising a substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may further contain 1,000 to 10,000 parts by weight of polyethylene glycol selected from the group consisting of PEG-300 and PEG-400.
The antitumor composition comprising a substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may further contain a non-ionic surfactant. Many different non-ionic surfactants are available but the inventors prefer to employ polysorbate-80 (Tween-80).
The antitumor composition comprising a substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may further contain a lower alcohol selected from the group consisting of ethanol and benzyl alcohol.
The antitumor composition comprising a substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may further a lower alcohol, polyethylene glycol, and a non-ionic surfactant.
The antitumor composition comprising a substituted camptothecin, N-methyl-2-pyrrolidinone, and acid and further containing a lower alcohol, polyethylene glycol, and a non-ionic surfactant wherein said acid is citric acid, wherein said lower alcohol is selected from the group consisting of ethanol and benzyl alcohol, wherein said polyethylene glycol is selected from the group consisting of PEG-300 and PEG-400, and wherein said surfactant is polysorbate-80.
Another embodiment of this invention is an antitumor composition comprising a solution or suspension containing an A-ring substituted camptothecin or containing a B-ring substituted camptothecin or containing both an A-ring substituted and a B-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein for each part by weight of substituted camptothecin said solution or suspension contains 1,000 to 10,000 parts N-methyl-2-pyrrolidinone, 100 to 5,000 parts of a pharmaceutically acceptable acid, 1,000 to 10,000 parts by weight of polyethylene glycol, and 1,000 to 5,000 parts of lower alcohol selected from the group consisting of ethanol and benzyl alcohol.
Yet another embodiment of this invention is an antitumor composition comprising a solution or suspension containing an A-ring substituted camptothecin or containing a B-ring substituted camptothecin or containing both an A-ring substituted and a B-ring substituted camptothecin having a water solubility of 5 micrograms or less than 5 micrograms per milliliter wherein for each part by weight of substituted camptothecin said solution or suspension contains 1,000 to 10,000 parts N-methyl-2-pyrrolidinone, 100 to 5,000 parts of a pharmaceutically acceptable acid, 1,000 to 5,000 parts of a lower alcohol, and 1,000 to 10,000 parts of a non-ionic surfactant. This invention also embodies the above antitumor composition wherein the acid is citric acid, wherein the alcohol is ethanol, and wherein the non-ionic surfactant is polysorbate-80.
For this invention "substituted camptothecin" applies to substitutions in the A-ring or substitutions in the B-ring or substitutions in both the A-ring and the B-ring. This invention includes substitutions at all possible locations on the A- and B-ring but the inventors prefer substitutions at position 7 of the B-ring and at positions 9, 10, and/or 11 of the A-ring.
This invention further embodies an injectable, sterile solution comprising N-methyl-2-pyrrolidinone, and a highly lipophilic camptothecin derivative having a water solubility 5 micrograms per milliliter or less, with the general structural formula: ##STR3## wherein R 1 , R 2 , R 3 , R 4 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 1 and R 2 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R 5 , R 6 , R 7 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 2 and R 3 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R.sub. 5, R 6 , R 7 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
wherein R 3 and R 4 together may represent --X 1 --X 2 --X 3 -- and wherein X 1 , X 2 , X 3 may be CR 5 R 6 , O, S or NR 7 and wherein R 5 , R 6 , R 7 =H, lower alkyl, alkoxy, acyloxy, hydroxy, acyl, halo, amido, or cyano group;
Another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, and a highly lipophilic camptothecin derivative further containing a pharmaceutically acceptable acid. This acid may be a carboxylic acid selected from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, gluconic acid, and lactic acid. Or, this acid may be a mineral acid selected from a group consisting of hydrochloric acid and phosphoric acid. The acid may also an acid selected from the group consisting of acetic acid, citric acid, fumaric acid, maleic acid, ascorbic acid, phosphoric acid, gluconic acid, lactic acid, and hydrochloric acid.
Yet another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, a highly lipophilic camptothecin derivative, and a pharmaceutically acceptable acid further containing a lower alcohol selected from the group consisting of ethanol and benzyl alcohol.
Yet another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, a highly lipophilic camptothecin derivative, and a pharmaceutically acceptable acid further containing a polyethylene glycol selected from a group consisting of PEG-300 and PEG-400.
Yet another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, a highly lipophilic camptothecin derivative, and a pharmaceutically acceptable acid further containing a non-ionic surfactant wherein the non-ionic surfactant is polysorbate-80 (Tween-80).
Yet another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, a highly lipophilic camptothecin derivative, and a pharmaceutically acceptable acid further containing a polyethylene glycol and a non-ionic surfactant.
Yet another embodiment of this invention is the above injectable, sterile solution comprising N-methyl-2-pyrrolidinone, a highly lipophilic camptothecin derivative, and a pharmaceutically acceptable acid further containing a lower alcohol, polyethylene glycol and a non-ionic surfactant.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, and acid may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Yet another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and lower alcohol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Yet another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and polyethylene glycol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, and non-ionic surfactant may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin, N-methyl-2-pyrrolidinone, acid, polyethylene glycol and non-ionic surfactant may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone, acid, polyethethylene glycol, non-ionic surfactant and lower alcohol may also further contain 1 to 10 parts by weight of taurocholic acid or a pharmaceutically acceptable salt thereof. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, inthrathecal, intracisternal, intravesicular intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension encapsulated within a hard gelatin capsule or a soft gelatin capsule.
Another embodiment of this invention is the above injectable sterile solution comprising an A-ring substituted or B-ring substituted or A- and B-ring substituted camptothecin and N-methyl-2-pyrrolidinone wherein this solution or suspension contains from about 1.0 mg to about 40.0 mg activity per ml of solution or suspension of the substituted camptothecin having a water solubility of less than 5 micrograms per ml of water. Another embodiment of this invention is the above solution or suspension prepared and sterilized for oral, intrapleural, intrathecal, intracisternal, intravesicular, intraperitoneal, topical or intravenous administration to a patient with cancer. Yet another embodiment of this invention is this solution or suspension is encapsulated within a hard gelatin capsule or a soft gelatin capsule.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In its preferred embodiments, this invention involves preparation and use of novel HLCD solutions or suspensions as described below.
EXAMPLES
The following examples illustrate selected modes for carrying out the claimed invention and are not to be construed as limiting the specification and claims in any way. These examples are provided so as to enable those in ordinary skill in the art to make the compositions of this invention. These examples are not intended to limit the scope of what the inventors regard as the invention. Efforts have been made to ensure accuracy with respect to numbers used to characterize the measured conditions; however, some experimental errors and deviations may be present.
Maintaining an acidic pH (3 to 5) in the HLCD solution or suspension is particularly important to reduce the slow conversion of HLCD lactone to the E-ring-hydrolyzed carboxylate, which occurs at physiological pH. At equilibrium under physiologic pH, the ratio of the open-ring (carboxylate) form to lactone species increases. Hydrolysis of the HLCD lactone ring will be substantially reduced if the drug is kept in an acidic environment. Some of the unpredictable toxicity seen in earlier clinical trials using SCPT may have been due to the in vivo formation of greater amounts of the lactone form of camptothecin, which is 10-fold more toxic than SCPT in mice. The lactone form of HLCD, as in camptothecin, is less water soluble than the carboxylate E-ring form. When early clinical trials were first conducted with camptothecin using sodium hydroxide, the significance of maintaining the closed lactone ring for uniform efficacy and safety in treating patients with cancer was poorly understood. The early reported unpredictable clinical toxicities associated with camptothecin administration may have been exacerbated by the sodium hydroxide formulation which promotes the formation of the carboxylate form, and by the relative lack of understanding of the significance of the lactone form of camptothecin as it relates to antitumor activity.
Example 1
Highly Lipophilic Camptothecin Derivative-NMP Formulation for Injection or Infusion
For injection or infusion into aqueous body fluids, a formulation contains from about 1.0 to about 40.0 parts by weight of HLCD in 1,000 to 10,000 parts by weight of NMP in a vehicle comprising between about 1,000 to about 5,000 part by weight of an acceptable alcohol, about 1,000 to about 10,000 parts by weight of polyethylene glycol, and about 1,000 to about 10,000 parts of a non-ionic surfactant. Suitable alcohols include dehydrated ethyl alcohol or benzyl alcohol, or combination of ethyl alcohol and benzyl alcohol. Suitable polyethylene glycols, include polyethylene glycol 300, polyethylene glycol 400, and polypropylene glycol. Suitable non-ionic surfactants include polysorbate-80 (Tween-80). In a preferred embodiment, the formulation of HLCD is supplied as an intravenous injectable in a vial comprising a solution of drug in a vehicle comprising ethyl alcohol and/or benzyl alcohol, citric acid, polyethylene glycol 400, and polysorbate (Tween 80).
Example 2
Highly Lipophilic Camptothecin Derivative-NMP Formulation #2
A second formulation contains from about 1.0 to about 40.0 parts by weight of HLCD in 1,000 to 10,000 part of NMP further comprising between about 1,000 to 5,000 parts of an alcohol, about 100 to 5,000 parts by weight of an pharmaceutically acceptable acid and about 1,000 to 10,000 parts of polyethylene glycol 400. Suitable alcohols include ethyl alcohol, and benzyl alcohol. Suitable acids for this formulation include citric acid, hydrochloric acid or phosphoric acid. In a preferred embodiment 1 to about 20 parts of HLCD by weight is formulated in 1,000 to 10,000 parts of NMP, 1,000 to 10,000 parts of PEG-400, 1,000 to 5,000 parts by weight ethyl alcohol, and 1,000 to 5,000 parts of citric acid by weight.
Example 3
Highly Lipophilic Camptothecin Derivative-NMP Oral Formulation
An oral formulation of HLCD in soft gelatin capsules (comprised of gelatin/glycerin/sorbitol/purifiers) containing from about 1.0 part to about 40.0 parts by weight of HLCD dissolved in 1,000 to 10,000 parts of NMP, citric acid 1,000 to about 5,000 parts by weight, glycerin 0.5 to 2.5 parts by weight, and polyethylene glycol (PEG-300 or PEG-400) 1,000 to 10,000 parts by weight, ethyl alcohol 1,000 to 5,000 parts by weight, and taurocholic acid 1 to 10 parts by weight. The soft gelatin capsules may also be composed of any of a number of compounds used for this purpose including for example, a mixture of gelatin, glycerin, sorbitol, and parabens.
Example 4
7-Ethyl Camptothecin-NMP Formulation
A formulation containing from about 1.0 to about 40.0 parts by weight of 7-ethyl camptothecin in 1,000 to 10,000 part of NMP further comprising between about 1,000 to 5,000 parts of an alcohol, about 100 to 5,000 parts by weight of an pharmaceutically acceptable acid and about 1,000 to 10,000 parts of polyethylene glycol 400. Suitable alcohols include ethyl alcohol, and benzyl alcohol. Suitable acids for this formulation include citric acid, hydrochloric acid or phosphoric acid. In a preferred embodiment 1 to about 20 parts of 7-ethyl camptothecin by weight is formulated in 1,000 to 10,000 parts of NMP, 1,000 to 10,000 parts of PEG-400, 1,000 to 5,000 parts by weight ethyl alcohol, and 1,000 to 5,000 parts of citric acid by weight.
Example 5
7-Ethyl-10-Hydroxy Camptothecin-NMP Formulation
A formulation containing from about 1.0 to about 40.0 parts by weight of 7-ethyl-10-hydroxy camptothecin in 1,000 to 10,000 part of NMP further comprising between about 1,000 to 5,000 parts of an alcohol, about 100 to 5,000 parts by weight of an pharmaceutically acceptable acid and about 1,000 to 10,000 parts of polyethylene glycol 400. Suitable alcohols include ethyl alcohol, and benzyl alcohol. Suitable acids for this formulation include citric acid, hydrochloric acid or phosphoric acid. In a preferred embodiment 1 to about 20 parts of 7-ethyl-10-hydroxy camptothecin by weight is formulated in 1,000 to 10,000 parts of NMP, 1,000 to 10,000 parts of PEG-400, 1,000 to 5,000 parts by weight ethyl alcohol, and 1,000 to 5,000 parts of citric acid by weight.
Example 6
10,11-Methylenedioxy Camptothecin-NMP Formulation
A formulation containing from about 1.0 to about 40.0 parts by weight of 10,11-methylenedioxy camptothecin in 1,000 to 10,000 part of NMP further comprising between about 1,000 to 5,000 parts of an alcohol, about 100 to 5,000 parts by weight of an pharmaceutically acceptable acid and about 1,000 to 10,000 parts of polyethylene glycol 400. Suitable alcohols include ethyl alcohol, and benzyl alcohol. Suitable acids for this formulation include citric acid, hydrochloric acid or phosphoric acid. In a preferred embodiment 1 to about 20 parts of 10,11-methylenedioxy by weight is formulated in 1,000 to 10,000 parts of NMP, 1,000 to 10,000 parts of PEG-400, 1,000 to 5,000 parts by weight ethyl alcohol, and 1,000 to 5,000 parts of citric acid by weight.
Example 7
10-Bromo Camptothecin-NMP Formulation
A formulation containing from about 1.0 to about 40.0 parts by weight of 10-bromo camptothecin in 1,000 to 10,000 part of NMP further comprising between about 1,000 to 5,000 parts of an alcohol, about 100 to 5,000 parts by weight of an pharmaceutically acceptable acid and about 1,000 to 10,000 parts of polyethylene glycol 400. Suitable alcohols include ethyl alcohol, and benzyl alcohol. Suitable acids for this formulation include citric acid, hydrochloric acid or phosphoric acid. In a preferred embodiment 1 to about 20 parts of 10-bromo camptothecin by weight is formulated in 1,000 to 10,000 parts of NMP, 1,000 to 10,000 parts of PEG-400, 1,000 to 5,000 parts by weight ethyl alcohol, and 1,000 to 5,000 parts of citric acid by weight.
Example 8
Use of N-methyl-2-pyrrolidinone (NMP) in the Formulations
One of the key discoveries in the present invention is the unexpectedly high solubility of HLCD in N-methyl-2-pyrrolidinone (NMP). N-Methyl-2-pyrrolidinone is an organic liquid excipient and is also known as 1-methylpyrrolidinone, N-methyl-2-pyrrolidinone, 1-methyl-5-pyrrolidinone, methylpyrrolidinone, N-methyl pyrrolidinone, methylpyrrolidinone, N-methylpyrrolidone, N-methyl-2-pyrrolidone, M-pyrol, and NMP.
NMP exhibits a high degree of physiologic safety in mammals with the following LD50 values: (rat) oral--7000 mg/kg, intraperitoneal--2472 mg/kg, intravenous--2266 mg/kg, (mice) oral--7725 mg/kg, intraperitoneal--4429 mg/kg, intravenous--3605 mg/kg, (rabbit) skin--8000 mg/kg (Registry of Toxic Effects of Chemical Substances, 1983-84 Supplement, Page 1628). NMP has been used to formulate etoposide (Etoposide, U.S. Pat. No. 4,772,589) and acridine derivatives (M-AMSA, U.S. Pat. No. 5,034,397). Etoposide and acridine derivatives (1) are anticancer drugs; (2) are chemically unrelated to HLCD; (3) are more water soluble than HLCD; and (4) exert their antitumor effects by vastly different mechanisms than HLCD.
NMP has also been used for oral formulations of the antibiotic clarithromycin (Clarithromycin, WO patent #9,014,094) and other drugs. NMP is a key excipient of the instant invention which allows an exceptionally high degree of drug solubility of HLCD (range 1 mg/ml to 40 mg/ml)in NMP as a solution or suspension. An HLCD solution comprising NMP with or without other combinations of excipients described herein, which can be diluted with a parenteral vehicle such as sterile injectable water USP, 5% Dextrose solution for injection USP or 0.9% sodium chloride solution for injection USP, such that the amount of HLCD dissolved in the diluted infusion is from about 0.001 mg/ml to about 1.0 mg/ml, is taught in the present invention. The inventors have discovered that HLCD show remarkably high solubility in NMP compared to other common pharmaceutical solvents such as water, ethanol, benzyl alcohol, propylene glycol, PEG 300, PEG 400, dimethylisosorbide or dimethylacetamide (Table 5). This high solubility of HLCD in NMP makes NMP a unique and highly useful pharmaceutical solvent for making useful solutions or suspensions of HLCD.
______________________________________Solubility of Camptothecin in Various SolventsSolvent Concentration, mg/ml______________________________________Milli-Q Water 0.0002Ethanol 0.051Benzyl alcohol 1.674Propylene glycol 0.281PEG 300 0.706Dimethylisosorbide 0.928Dimethylacetamide 5.000N-Methyl-2-pyrrolidinone (NMP) >15.000 (range 15-20)______________________________________
NMP is inert with respect to undesirable chemical reactions with HLCD and is therefore a highly useful excipient to create solutions of HLCD in the lactone form. Further utility of NMP in the present invention is the discovery that NMP allows the introduction of additional excipients which further improve the overall utility of the HLCD dissolved in the NMP solution in a manner which are of additional benefit for parenteral or oral administration to human patients with cancer. The HLCD solution or suspension is prepared by mixing the desired components with NMP and adding a pharmaceutically acceptable acid to adjust the pH to 3-5.
REFERENCES
The following references may facilitate understanding or practice of certain aspects of the present invention. Inclusion of a reference in this list is not intended to and does not constitute an admission that the reference represents prior art with respect to the present invention.
______________________________________U.S. Pat.4,545,880 10/85 Miyasaka et al.4,473,692 9/84 Miyasaka et al.4,778,891 10/88 Tagawa et al.5,061,800 10/91 Miyasaka et al.4,772,589 9/88 Kaplan et al.5,034,397 7/91 Kaplan et al.World Patent9,014,094 11/90 Hui et al.______________________________________
Other Publications
Barilero et al., Simultaneous Determination of the Camptothecin Analogue CPT-11 and Its Active Metabolite SN38 by High Performance Liquid Chromatography: Application to Plasma Pharmacokinetic Studies in Cancer Patients. J. Chromat. 575:275-280; 1992.
Bates et al., Solubilizing Properties of Bile Salt Solutions. I. Effect of Temperature and Bile Salt Concentration On Solubilization of Glutethimide, Griseofulvin and Hexostrol. Journal of Pharmaceutical Sciences, 55:191-199, (1966).
Bates et al., Rates of Dissolution of Griseofulvin and Hexestrol in Bile Salt Solutions. Chem. Abstracts 65:8680b, 1966.
Bates et al., Solubilizing Properties of Bile Salt Solutions on Glutethimide, Griseofulvin, and Hexestrol. Chem. Abstracts 64 :9517e 1966; 65:15165a, 1966.
Clavel, M. et al., Phase I Study of the Camptothecin Analogue CPT-11, Administered Daily for 3 Consecutive Days. Proc. Amer. Assoc. Cancer Res. 3:83, 1992.
Creaven, P. J. et al., Plasma Camptothecin (NSC-100880) Levels During a 5-Day Course of Treatment: Relation to Dose and Toxicity. Cancer Chem. Rep. 56: 573-578, 1972.
Culine, S., Phase I Study of the Camptothecin Analog CPT-11, Using a Weekly Schedule. Proc. of Amer. Soc. Clin. Onc. 11:110, 1992.
Emerson, D. L., In Vivo Antitumor Activity of Two New Seven-substituted Water-soluble Camptothecin Analogues. Cancer Research. 55: 603-609, 1995.
Fukuoka, M. et al., A Phase II Study of CPT-11, A New Derivative of Camptothecin, for Previously Untreated Small-Cell Lung Cancer. J. Clin. Onc. 10(1):16-20, 1992.
Giovanella B. C., et al., DNA Topoisomerase I-Targeted Chemotherapy of Human Colon Cancer in Xenografts. Science 246: 1046-1048; 1989.
Gottlieb, J. A. et al., Preliminary Pharmacologic and Clinical Evaluation of Camptothecin Sodium (NSC-100880). Cancer Chem. Rep. 54: 461-470, 1970.
Gottlieb, J. A. et al., Treatment of Malignant Melanoma With Camptothecin (NSC-100880). Cancer Chem. Rep. 56: 103-105, 1972.
Hsiang et al., Arrest of Replication Forks by Drug-stabilized Topoisomerase I-DNA Cleavable Complexes as a Mechanism of Cell Killing by Camptothecin Analogues. Cancer Res. 49:5077-5082, 1989.
Houghton, P. J. et al., Therapeutic Efficacy of the Topoisomerase I Inhibitor 7-Ethyl-10-(4- 1-piperidino!-1-piperidino) -carbonyloxy-camptothecin against Human Tumor Xenografts: Lack of Cross-Resistance in Vivo in Tumors with Acquired Resistance to the Topoisomerase I Inhibitor 9-Dimethylaminomethyl-10-hydroxycamptothecin. Cancer Res. 53:2823-2829, 1993.
Jaxel, C. et al., Structure Activity Study of the Actions of Camptothecin Derivatives on Mammalian Topoisomerase I: Evidence for a Specific Receptor Site and a relation to Antitumor Activity. Cancer Res. 49:1465-1469, 1989.
Kaneda, N. et al., Metabolism and Pharmacokinetics of the Camptothecin Analogue CPT-11 in the Mouse. Cancer Research 50:1715-1720, 1990.
Kano Y, et al., Effects of CPT-11 in Combination with other Anti-Cancer Agents in Culture. Int. J. Cancer 50:604-610;1992.
Kanzawa F, et al., Role of Carboxylesterase on Metabolism of Camptothecin Analog (CPT-11) in Non-Small Cell Lung Cancer Cell Line PC-7 Cells (Meeting Abstract). Proc. Annual Meet. Am. Assoc. Cancer Res. 33:A2552; 1992.
Kawato, Y. et al., Intracellular Roles of SN38, a Metabolite of the Camptothecin Derivative CPT-11, in the Antitumor Effect of CPT-11. Cancer Res. 51:4187-4191, 1991.
Kunimoto, T. et al., Antitumor Activity of 7-Ethyl-10- 4-(1-piperidino) -1-piperidinol!Carbonyloxy-Camptothecin, a Novel Water Soluble Derivative of Camptothecin Against Murine Tumors. Cancer Res. 47:5944-5947, 1987.
Luzzio, M. J., et al., Synthesis and Antitumor Activity of Novel Water Soluble Derivatives of Camptothecin as Specific Inhibitors of Topoisomerase I. J. Med. Chem. 38: 395-401, 1995.
Malone et al., Desoxycholic Acid Enhancement of Orally Administered Reserpine. Journal of Pharmaceutical Sciences, 55:972-974 (1966).
Masuda, N. et al., CPT-11: A New Derivative of Camptothecin for the Treatment of Refractory or Relapsed Small-Cell Lung Cancer. J. Clin. Onc. 10(8):1225-1229 1992.
Moertel, C. G. et al., Phase II Study of Camptothecin (NSC-100880) in the Treatment of Advanced Gastrointestinal Cancer. Cancer Chem. Rep. 56: 95-101, 1972.
Muggia, F. M. et al., Phase I Clinical Trial of Weekly and Daily Treatment with Camptothecin (NSC-100880): Correlation with Preclinical Studies. Cancer Chem. Rep. 56: 515-521, 1972.
Negoro, S. et al., Phase I Study of Weekly Intravenous Infusions of CPT-11, a New Derivative of Camptothecin, in the Treatment of Advanced Non-Small Cell Lung Cancer. JNCI 83(16): 1164-1168, 1991.
Negoro, S. et al., Phase II Study of CPT-11, New Camptothecin Derivative, in Small Cell Lung Cancer. Proc. of Amer. Soc. Clin. Onc. 10:241, 1991.
Niimi S, et al., Mechanism of Cross-Resistance to a Camptothecin Analogue (CPT-11) in a Human Ovarian Cancer Cell Line Selected by Cisplatin. Cancer Res. 52:328-333; 1992.
Ohe, Y. et al., Phase I Study and Pharmacokinetics of CPT-11 with 5-Day Continuous Infusion. JNCI 84(12):972-974, 1992.
Ohno, R. et al., An Early Phase II Study of CPT-11: A New Derivative of Camptothecin, for the Treatment of Leukemia and Lymphoma. J. Clin. Onc. 8(11):1907-1912, 1990.
Pantazis, P. et al., Cytotoxic Efficacy of 9-Nitrocamptothecin in the Treatment of Human Malignant Melanoma Cells in Vitro. Cancer Research. 54: 771-776, 1994.
Pommier, Y. et al., Camptothecins: Mechanism of Action and Resistance (Meeting Abstract). Cancer Investigation, Presented at the "Chemotherapy Foundation Symposium X Innovative Cancer Chemotherapy for Tomorrow," page 3, 1992.
Potmesil, M. et al., Preclinical and Clinical Development of DNA Topoisomerase I Inhibitors in the United States. in Andoh,T., Ikeda, H. Oguro, M. (eds): Molecular Biology of DNA Topoisomerases and Its Application to Chemotherapy. Boca Raton, Fla., CRC Press, Inc. 301-311, 1993.
Rivory, L. P., et al., Kinetics of the in Vivo Interconversion of the Carboxylate and Lactone Forms of Irinotecan (CPT-11) and of its Metabolite SN-38 in Patients. Cancer Research. 54:6330-6333, 1994.
Rothenberg, M. L. et al., A Phase I and Pharmacokinetic Trial of CPT-11 in Patients with Refractory Solid Tumors. Amer. Soc. Clin. Onc. 11:113, 1992.
Rothenberg, M. L., Kuhn, J. G., Burris, H. A., Nelson, J., Eckardt, J. R., Tristan-Morales, M., Hilsenbeck, S. G., Weiss, G. R., Smith, L. S., Rodriguez, G. I., Rock, M. K., Von Hoff, D. D. Phase I and Pharmacokinetic Trial of Weekly CPT-11. Journal of Clinical Oncology. 11:2194-2204 (1993).
Rowinsky, E. et al., Phase I Pharmacologic Study of CPT-11, A Semisynthetic Topoisomerase I-Targeting Agent, on a Single-Dose Schedule (Meeting Abstract). Proc. of Amer. Soc. Clin. Onc. 11:115, 1992.
Sawada S. et al., Synthesis and Antitumor Activity of 20 (S)-Camptothecin Derivatives: Carbonate-Linked, Water Soluble, Derivatives of 7-Ethyl-10-hydroxycamptothecin. Chem. Pharm. Bull. 39:14446-1454; 1991.
Shimada, Y. et al., Phase II Study of CPT-11, New Camptothecin Derivative, In the Patients with Metastatic Colorectal Cancer. Proc. of Amer. Soc. Clin. Onc. 10:135, 1991.
Supko, J. G. et al., Pharmacokinetics of the 9-Amino and 10,11-Methylenedioxy Derivatives of Camptothecin in Mice. Cancer Res. 53: 3062-3069, 1993.
Takeuchi, S. et al., Late Phase II Study of CPT-11, A Topoisomerase I Inhibitor, In Advanced Cervical Carcinoma (CC) (Meeting Abstract). Proc. of Amer. Soc. Clin. Onc. 11:224, 1992.
Wall, M. E. et al., Camptothecin and Taxol: Discovery to Clinic-Thirteenth Bruce F. Cain Memorial Award Lecture. Cancer Research. 55:753-760, 1995.
Wall, M. E. et al., Camptothecin, in Cassady J.M., Douros J.D. (eds): Anticancer Agents Based on Natural Product Models, San Diego, Calif., Academic Press, 1980, 417-436.
Wall, M. E. et al., Plant Antitumor Agents: Synthesis and Structure Activity of Novel Camptothecin Anaglogs. J. Med. Chem., 36:2689-2700 (1993).
Westergaard et al., The Mechanism Whereby Bile Acid Micelles Increase the Rate of Fatty Acid and Cholesterol Uptake Into the Intestinal Mucosal Cell. Journal of Clinical Investigation, 58: 97-108 (1976)).
The foregoing description has been directed to particular embodiments of the invention in accordance with requirements of the Patent Statutes for the purposes of illustration and explanation. It will be apparent, however, to those skilled in this art, that many modifications, changes and variations in the claimed antitumor compositions, solutions, methods of administration of the antitumor compositions set forth will be possible without departing from the scope and spirit of the claimed invention. It is intended that the following claims be interpreted to embrace all such modifications and changes.
|
A- and/or B-ring substituted camptothecin derivatives, which are poorly water soluble (less than 5 micrograms per milliliter of water), are highly lipophilic camptothecin derivatives (HLCD) and are very active against a variety of human cancers. Because of their very poor water solubility, HLCD have not been used to treat human patients with cancer due to the inability to administer sufficient quantities of the HLCD dissolved in a pharmaceutical formulation. This invention overcomes these limitations by teaching novel pharmaceutically acceptable HLCD formulations for the direct administration of HLCD to human patients with cancer. The claimed invention also describes the methods to create solutions of HLCD and antitumor compositions of HLCD to allow the administration of HLCD in sufficient amounts to treat human patients with various types of cancer. This invention is also directed to injectable sterile solutions, antitumor compositions, solutions and suspensions comprising N-methyl-2-pyrrolidinone and a highly lipophilic camptothecin derivative.
| 0
|
BACKGROUND OF THE INVENTION
The invention relates to the longitudinal compressive treatment of webs in which a stationary retarder surface acts upon a driven web to cause the web to slow and longitudinally compact or crepe in a treatment zone. This technique, sometimes referred to as microcreping because of its ability to produce fine crepes, is exemplified by our prior U.S. Pat. Nos. 3,810,280, 4,142,278 and 5,060,349, which are incorporated herein by reference.
As described in our '349 patent, a particularly-advantageous retarder sheet for a microcreper comprises a large multiplicity of parallel ridges and grooves biased obliquely to the direction of drive of the web. However, in some cases a web treated by such a retarder member, as it passes from the smooth primary surface to the obliquely-grooved retarder surface, may tend to travel at an angle to the feeding direction of the roll, and deform into a parallelogram. The treated web may retain this deformation even after it is wound onto a take-up roll.
Previous methods of correcting this parallelogram deformation have resulted in deformations to the web, for instance stretching that has tended to defeat the purpose of the compressive treatment, or uneven stretching of the web that give the web an undesired, Moire textured appearance.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved microcreper that uses a retarder surface with a large multiplicity of parallel ridges and grooves biased obliquely to the direction of drive of the web, but which produces a treated web without having a detrimental tendency to travel at an angle to the feed direction of the roll and without distorting the web into a parallelogram, and that does not impart a Moire pattern, or other blemishes, to the web.
In general, in a first aspect, the invention relates to an apparatus for longitudinal compressive treatment of a continuous web of material, the apparatus comprising a cylindrical drive roll for advancing the web, a smooth-surfaced primary member to press the web against the drive roll, and a generally-stationary retarder downstream of the primary member to engage and retard the web before the web has left the drive roll. According to the invention, the initially-effective retarder surface of the retarder, which has a large multiplicity of parallel ridges and grooves extending across the width of the web, is combined with a reorienting retarding surface. The ridges of the initially-effective retarding surface are uniformly biased obliquely to the direction of drive of the web, and are effective to cause longitudinal compression of the web together with orientation of the web to flow at an angle to the original direction of drive of the web induced by the drive roll. The reorienting retarding surface is disposed to be effective after an incremental advance of the web at the angle, the reorienting retarding surface constructed to have a supplementary retarding effect that is cooperative with said drive roll to reorient the travel of the web to a direction generally parallel to the original direction of drive.
In one preferred embodiment, the retarder has two ridge-and-groove regions, the upstream region providing the initially-effective retarder surface, and the more-downstream region forming the reorienting retarding surface. The ridges of the downstream region are biased in a reverse angle relative to that of the ridges and grooves of the upstream ridge-and-groove region. In preferred cases, the bias angle of the downstream region, e.g., forty-five degrees, is larger than the bias angle of the upstream region, e.g., thirty degrees.
In another preferred embodiment, the reorienting retarding surface comprises roughening of the surface within the grooves of the retarder, the ridges having smooth flat tops over which the web can slide. The roughening is applied to the surface within the grooves of the retarder by plasma coating. The drive roll has a rougher surface than the surface within the grooves of the retarder.
These and other preferred embodiments may include the following features. The retarder comprises a sheet-form member that can be reoriented in the machine to expose a different portion of the sheet to wear. The ridges have flat top surfaces for engaging the web, which, in certain preferred embodiments, are plated with a hard, smooth material. The ridges have sharp edges. The primary member and retarder comprise an assembly of superposed sheet members extending across the width of the web on the drive roll.
Microcrepers according to the invention offer a number of advantages. During the process of manufacturing knit goods, the knit web is stretched, cut, and pulled through a number of processing steps. Because the web is in longitudinal tension during much of this manufacture process, the web tends to neck down, that is, to reduce in width and stretch in length. These manufacturing steps tend to impart uneven deformations to the web, degrading the appearance of the web and impairing easy manufacture of dimensionally-stable finished goods. A microcreper according to the invention, when used as the last stage in a knit manufacture line before the knit is cut and sewn, tends to widen the web, correcting the necking-down. The uneven tensions in the web are allowed to even out across the length and width of the web, improving the manufacturing characteristics of the web. The multiple grooves and ridges of the retarder surface produce a treated web with especially desireable properties. The web comes off the microcreper straight, without parallelogram deformation. Because the retarder surface does not have sharp points, as would be found on a roughened retarder surface, the retarder surface does not pick loops from nor cause fuzziness in the web, nor does it ablate dust from the web.
In a second aspect, the invention relates to an apparatus for longitudinal compressive treatment of a continuous web of material, the apparatus comprising a cylindrical drive roll for advancing the web, an assembly of sheet-form members to press the web against the drive roll, said drive roll and primary member being wider than the web, and a tape of a tough, slippery material, the tape held generally stationary in the portion of the engagement region between the sheet assembly and the drive roll not occupied by the web. The tape may preferably be of polyester film.
Other advantages and features of the invention will become apparent from the following description of a preferred embodiment, and from the claims.
FIG. 1 is a perspective view of a so-called bladeless microcreper.
FIG. 1a is a top plan view, partially cut away, detailing the treatment region of the microcreper of FIG. 1.
FIG. 1b is a diagrammatic cross-section on enlarged scale taken on lines 1b/1b of FIG. 1a.
FIGS. 1c-1e are section views of the microcreper.
FIG. 2 is a perspective view of a sheet assembly.
FIG. 2a is a sectional view of a retarder sheet.
FIG. 3 is a plan view of the underside of a retarder sheet.
FIG. 3a is a perspective view of a sheet assembly.
FIG. 3b is a side plan view of a sheet assembly.
FIG. 4 is a plan view of the underside of a retarder sheet.
FIG. 4a is a sectional view of a retarder sheet.
FIG. 5 is a side plan view of a sheet assembly.
FIG. 6 is a perspective view of a microcreper, partially cut-away.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a microcreper according to the invention. A cylindrical drive roll 100 rotates in direction 106 to advance a web of material 190 past feeding shoe surface 112 and retarder surface 114. The roll is typically steel, of e.g. 12-inch diameter, and has a web-gripping surface 102 provided by fine carbide particles applied by plasma coating. The feeding and retarder surfaces are provided as an assembly of sheet-form members mounted in a sheet holder 200 and extending forward. The assembly passes under presser member 150 and over roll surface 102 where it engages web 190 against the ro11.
Referring to FIGS. 1a and 1b, the sheet assembly comprises a primary feeding member 112 closest to the roll, and a retarder sheet 114. The roll-facing surface of the retarder sheet comprises a large multiplicity of parallel ridges and grooves biased obliquely to the direction of drive 106 of the web. The retarder sheet is shown partially cut away, exposing ridges 202. As the web 190 engages the ridges, friction causes longitudinal compression of the web, and the web orients to flow at an angle 107 to the original direction of drive 106 induced by the drive roll, as shown in region 170. For instance, in FIG. 1a the ridges are set at 30°, and the web flows at 20°. The retarder surface comprises reorienting retarding surface, not shown, so that after the web has advanced incrementally beyond the region 170 of angled flow, the reorienting retarding surface reorients the travel of the web to a direction generally parallel to the original direction of drive, as shown in region 172. The web, no longer following the grooves, ratchets past the remaining grooves and ridges.
Referring to FIG. 1c, from the bottom up, the sheet assembly consists of a primary feeding member 112, one or more retarder sheets 114 which support a retarder surface formed by ridges 202 and grooves 204, and a conformer member 118 of form specially curved to apply force to the tip portion of the sheet assembly. Typically, each of feeding primary 112, retarder 114, and conformer members 118 are formed of sheets of blue spring steel. Feeding primary member 112 has a smooth under-surface and is arranged, by the influence of presser member edge 150', to press web 190 into driven engagement with the surface 102 of drive roll 100. The downstream edge 112' of primary member 112 lies slightly downstream from alignment with presser member edge 150'. Retarder sheet 114 has a large multiplicity of grooves 204 and ridges 202 set obliquely to the direction of drive of the web. The sheet form members are positioned by sheet holder 200, with the free end of the pre-curved conformer member 118 engaged upon the retarder sheet 114 near the free tip of the latter. To reach the operative condition, the head, comprising the presser member 150, the holder 200 and the sheet assembly 110, are rotated as a unit by pneumatic actuators, not shown, to the operative position of FIGS. 1b and 1c.
FIG. 1d and the magnified view of FIG. 1e show a microcreper in operative position. Pressure member 150 forces each of the sheet members, particularly primary member 112, into engagement with web 190 against roll 100. The retarder sheet 114 is bowed to conform to the roll, as a result of pressure applied to its tip region by the cantilevered end of conformer member 118. As seen most clearly in FIG. 1e, as the web emerges from under the edge 112' of the primary member 112, it expands vertically to fill the cavity between roll 100 and retarder sheet 114, and compresses longitudinally. The web is retarded at the leading edge of each ridge 202.
Referring to FIGS. 2 and 2a, the roll-facing surface of a retarder sheet has a retarder surface comprising a large multiplicity of parallel ridges 202 and grooves 204 biased obliquely to the direction of drive of the web. As shown in FIG. 2a, in one such retarder sheet, the overall thickness of the polished steel sheet is 0.010", the ridges are 0.010" wide and the grooves are 0.040" wide and 0.005" deep. Bias angles of 10° to 50° from the direction of drive have been found useful, and 30° to 45° preferable, varying with the material to be treated. Because this retarder surface does not have sharp points (as would be found on a roughened retarder surface), the biased retarder surface does not pick loops from the web, nor cause fuzziness in the web, nor raise dust.
In the invention, the retarder sheet of FIGS. 2 and 2a is modified so that the web, after initially being diverted by the grooves and ridges to travel at an angle to the original direction of drive induced by the drive roll, is reoriented to travel in a direction generally parallel to the original direction of drive 106, thereby causing the web to ratchet past the grooves and ridges 202. This reorienting overcomes a deficiency of the unmodified retarder sheet, in that the web emerges from the microcreper in a square conformation, rather than deformed into a parallelogram.
FIGS. 3, 3a and 3b show an embodiment of the invention in which the retarder sheet of the invention is divided into three regions. The center region 310 uses 0.010" ridges and 0.040×0.005" grooves biased at 30°, as in the retarder sheet of FIG. 2. In addition, a strip 312 of 0.010" ridges and 0.040×0.005" grooves back-biased at -45° is appended on the downstream edge. Typically, half or more of the retarder sheet is covered under the primary sheet member, the edge 112' of which is shown in phantom. As the retarder sheet wears, it can be reversed end-for-end, exposing the other -45° region 314, doubling the life of the retarder sheet. The full length of the center 30° portion 310 (measured in the direction of drive of the web) is typically two inches, about 3/4" of which is typically exposed out from under the primary member. The length of -45° sections 312 and 314 is typically 1/4". Because the grooves of both the 30° and -45° regions are set on the same 0.050" centers, the grooves do not meet end-for-end at the boundary 316 between the regions. As most clearly seen in FIG. 3b, the sheet is precurved to conform to the circumference of the roll, and conformer member 118 exerts its maximum force very near the downstream edge of the retarder. Thus, the downstream edge of the retarder surface exerts a larger force on the web than more-upstream portions of the retarder.
The 30 °/-45° embodiment can either be milled into a single sheet as shown in FIG. 3, or the embodiment can be formed of a 45° sheet lapped over a 30° sheet, as shown in FIGS. 3a and 3b.
The embodiment of FIGS. 3, 3a and 3b is especially useful for knits thicker than 0.030", for instance fleecy knits with a nap. The web is fed through the microcreper with the nap face against the roll.
Referring to FIG. 4, in a second embodiment, a 30° single-region 410 retarder sheet is plasma-coated with tungsten carbide to a roll surface 100-120 RMS. The plasma coating is sanded or stoned off of the ridges. Thus, as shown in section in FIG. 4a, the retarder sheet has slightly-roughened grooves 404 and smooth ridges 402. The roll is also typically plasma-coated, to a surface roughness of RMS 100-110. Thus, the retarder grooves are somewhat smoother than the roll surface. The embodiment of FIG. 4 is especially useful for treating knits of 0.025" thickness or less, for instance pique, jersey and interlock knits which are typically about 0.015" thick.
Referring to FIG. 5, in a third embodiment, the retarder surface includes an uncoated 30° ridge-and-groove retarder sheet 502 followed by a plasma-coated 30° ridge-and-groove retarder sheet 504. This retarder surface works well to reduce shine or gloss on the surface of the web.
It is desireable that the edges of the ridges, especially the upstream edge of each ridge, be relatively sharp. As the retarder sheet wears, the edges should be periodically resharpened, for instance by replacing the retarder sheet, by reversing the member and exposing a new surface, by stoning the faces smooth, or by running the microcreper with no web engaged, thereby polishing the retarder sheet against the face of the roll.
The retarder sheet, especially the faces of the ridges, can be chrome-plated for longer life.
Note that the mirror image of each of the three retarder sheets would work just as well. Bias angles for regions 310, 410, 502, and 504 from 20° to 40° may be useful, and for edge strip 312 from -40° to -50°. The configuration of the ridges and grooves may vary with the nature of the web. The grooves should be wider than the ridges, preferably several times wider. The ridges should be on centers no wider than 0.25" and no narrower than 0.010", and will typically be near the inter-rib spacing of the knit. The retarder sheet should be fairly thin, typically 0.010", so that it is flexible enough to conform to the roll. This, in turn, limits the depth of the grooves to no more than the thickness of the retarder sheet.
All knit fabrics have ribs or similar surface features produced by the loops of the knit. In some knits, the ribs are subtle, for instance the lines where threads of adjacent loops cross. Some knits have obvious ribs; these should not be crushed by the microcreper. It has been found preferable that the ridge-to-ridge spacing of the retarding surface be about equal to the rib-to-rib spacing of the fabric, up to a few times larger. It is believed that the ridges should have flat top faces, rather than, for instance, a saw-tooth profile.
The choice from among the three embodiments, or from among other embodiments within the claims, will vary with the material to be treated, and the desired result of the treatment.
Chemical milling is the preferred method of forming the grooves into the retarder sheet, though various ablating, grinding and machining methods are also possible.
In a knit manufacturing line, a microcreper is typically the last step in the line before the knit web is inspected and batched (rolled or folded) for shipment to a finished goods manufacturer. Knitting machines typically knit a tube of material; before batching the material undergoes a number operations, including slitting, that impart desireable and undesirable deformations to the web. Among the undesirable deformations are those that stretch the web longitudinally, causing it to neck down laterally, and those that stretch the web non-uniformly. Further, the weight of the yarn varies, imparting further non-uniformity to the web.
A microcreper with a grooved retarder sheet according to the invention generally causes the web to compact longitudinally and regain some of its lateral width, and allows much of the non-uniform deformation to even out across the length and width of the web, without deforming the web into a parallelogram. Further, the described retarder surfaces allow this evening-out to occur in spite of the unevenness of the yarn, etc. For instance, a grooveless plasma-coated retarder sheet has been found to produce streaks in the web where irregularities in the web are retarded differentially and unevenly stretch the web.
The retarder sheets of the invention, with biased grooves and a grooved reorienting retarding surface, result in webs with especially desireable properties, apparently because the diagonal ridges and grooves function as small compaction zones: each ridge tends to isolate irregularities in one groove's compaction zone from the next groove's zone. Also, the web receives multiple compressive treatments as it is driven under multiple grooves and ridges before it leaves the retarder surface.
Referring again to FIG. 1e, in these three embodiments, the web follows the drive roll 100 and is gradually pressed between the roll and the smooth under-surface of the primary member 112, into driving engagement with the gripping surface of the roll. When the web emerges from under the edge 112' of the primary, it immediately engages the ridges 202 of the retarding surface or against previously compressed material, and longitudinally compacts. In the case of embodiments employing roughening of the surface within the grooves of the retarder, e.g. FIGS. 1b and 2, the roughening resists sliding of the web along the biased ridges 202, causing enhanced compaction. Thus, the web thickens and engages the drive roll sufficiently that the urging of the drive roll takes over and causes the web to resume travel essentially parallel to the original direction of drive, so that the web passes over the ridges of the downstream portion of the retarder.
In the 30°/-45° embodiment of FIGS. 3, 3a and 3b, the web initially slides along the 30° ridges, during which it may be progressively compressed longitudinally. When the web reaches the -45° section, because of the curvature of the retarder member and the force exerted by conformer member 118, significant retarding can be applied at this downstream edge of the retarder. Also, the now-thickened web is forced to leave the original grooves and pass over the ridges of the reverse set. Therefore, in this region, the web is caused to more tightly engage the drive roll surface, and the forward urging of the drive roll causes the web to reorient to essentially follow the direction of the drive roll.
Referring to FIG. 6, the web under treatment is often narrower than the full width of the drive roll and sheet assembly. The sheet assembly 110 drags on the drive roll 100, and both wear prematurely. A roll 600 of a tough, slippery plastic tape 602, for instance 8"×5 mil mylar, can be mounted between the sheet assembly 110 and the drive roll 100. The tape roll is mounted on a fixed shaft so that it does not unroll under the force applied by the drive roll, but can be inspected every hour or so and advanced as necessary by an operator. Thus, the drive roll slips against the relatively slippery and inexpensive tape 602 instead of wearing against the relatively hard and expensive sheet assembly 110. The tape can be positioned on the shaft, by sliding in the direction of the axis of the roll, so that the space between the edge of the tape and the edge of the web is narrow enough so that the sheet assembly is cantilevered at both ends of the space and does not drag on the roll.
Other embodiments are within the following claims.
|
Apparatus for longitudinal compressive treatment of a continuous web of material. The apparatus comprises a cylindrical drive roll for advancing the web, a smooth-surfaced primary member to press the web against the drive roll, and a generally-stationary retarder downstream of the primary member to engage and retard the web before the web has left the drive roll. The retarder surface has a large multiplicity of parallel ridges and grooves set on a diagonal, and effective to cause longitudinal compression of the web and to cause the web to flow at an angle to the original direction of drive. The retarder surface also has a reorienting retarding surface, effective after the web advances incrementally at the angle, to effect further compression and to reorient the travel of the web to be generally parallel to the original direction of drive.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(a) from Korean Patent Application No. 2006-0116463, filed on Nov. 23, 2006 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present general inventive concept relates to a head chip and ink cartridge and an image forming apparatus having the same, and more particularly, to a head chip and ink cartridge having an improved ink supplying slit structure and an image forming apparatus having the same.
[0004] 2. Description of the Related Art
[0005] An image forming apparatus forms image data onto a recording medium according to a printing signal which is applied by a host. Generally, the image forming apparatus is divided into an inkjet type where an image is formed by discharging ink onto a recording medium, an electrophotographic type where the image is formed by selectively applying developer onto the recording medium using electric potential differences among a photosensitive member, the developer, and a transfer roller, and a thermal printing type where the image is formed by contacting an ink ribbon coated with ink with the recording medium and applying heat and pressure to transfer the ink to the recording medium.
[0006] According to the inkjet type image forming apparatus, an ink cartridge in which the ink is stored discharges the ink onto the recording medium to form the image. The inkjet type image forming apparatus is divided into a shuttle type, where the ink cartridge discharges the ink while it shuttles in a direction perpendicular to a feeding direction of the recording medium, and a line head type, where the ink cartridge is provided to have a width to correspond to a width of the recording medium and forms the image by discharging the ink per whole width.
[0007] FIG. 1 is a perspective view illustrating a conventional ink cartridge 10 . As illustrated in FIG. 1 , the ink cartridge 10 comprises an ink storing part 11 which stores the ink, and a flexible printed circuit board (FPCB) 20 , which is attached to the ink storing part 11 and exchanges an electrical signal with an image forming apparatus main body (not illustrated) through a contact pad 21 . The FPCB 20 comprises a head chip 30 which discharges the ink of the ink storing part 11 onto the recording medium. The head chip 30 is attached to a head chip receiving hollow 13 of the ink cartridge 10 . The head chip 30 is coupled with the head chip receiving hollow 13 by an adhesive.
[0008] FIGS. 2A and 2B are sectional views illustrating the ink cartridge 10 of FIG. 1 . Referring to FIGS. 2A and 2B , the head chip 30 comprises a substrate layer 32 having an ink supplying slit 31 which is supplied with the ink from an ink supplying hole 15 of the ink storing part 11 , a chamber layer 34 having a heater 33 which heats the ink supplied from the ink supplying slit 31 , and a nozzle layer 36 having a nozzle 35 where an ink bubble generated by heat from the heater 33 is used to discharge the ink to an outside.
[0009] To manufacture the conventional ink cartridge having above structure, an adhesive A is applied onto a border surface to couple the head chip 30 with the ink storing part 11 , and then the ink cartridge goes through a heat treatment at about 110° C. Therefore, the head chip 30 and the ink storing part 11 are solidly coupled therebetween.
[0010] However, since the ink storing part 11 of the conventional ink cartridge 10 is made of plastics and the substrate layer 32 of the head chip 30 is made of silicon, a shear stress F is generated on the border surface between the two materials which are of different kinds by a difference in coefficients of thermal expansion while the ink cartridge 10 goes through the heat treatment at about 110° C. In particular, as the coefficient of thermal expansion of the plastics is 50 times greater than that of the silicon, a bending deformation δ is generated in the substrate layer 32 as illustrated in FIG. 2B . The bending deformation of the substrate layer 32 causes a bending deformation of the nozzle layer 36 , which is provided at an upper side of the substrate 32 .
[0011] If the deformation is generated in the nozzle layer 36 , the ink is discharged through the nozzle 35 obliquely instead of perpendicularly onto the recording medium, so that a printing quality is deteriorated.
[0012] Also, during a wiping process for removing foreign substances or ink which is attached to a surface of the nozzle, the nozzle layer 36 may be damaged due to the bending deformation of the nozzle layer 36 .
[0013] Moreover, the problem caused by the bending deformation of the head chip 36 as described above may be more serious in a case of a line head, where the head chip 30 is plurally provided.
SUMMARY OF THE INVENTION
[0014] The present general inventive concept provides a head chip and ink cartridge having a reinforcing bridge to minimize deformation of the head chip when the head chip is coupled with an ink storing part, and an image forming apparatus having the same.
[0015] Additional aspects and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present general inventive concept.
[0016] The foregoing and/or other aspects and utilities of the present general inventive concept can be achieved by providing a head chip usable in an image forming apparatus, the head chip comprising a nozzle layer having a nozzle to discharge ink onto a recording medium, a substrate layer having at least one ink supplying slit provided to be parallel with the nozzle layer to supply the nozzle with the ink, and at least one reinforcing bridge provided along an extending direction of the ink supplying slit and blocks at least one region of the ink supplying slit.
[0017] A thickness of the reinforcing bridge may not greater than the thickness of the substrate layer.
[0018] A width d of the reinforcing bridge may be p×2≦d≦p×6 and p may be a pitch between adjacent nozzles.
[0019] The reinforcing bridge may be provided plurally along the extending direction of the ink supplying slit.
[0020] The substrate layer may comprise a plurality of ink supplying slits which are provided to be parallel therewith.
[0021] Each of the plurality of ink supplying slits may supply the nozzle with ink of a different color.
[0022] A reinforcing bridge of a first ink supplying slit may be aligned with a reinforcing bridge of a neighboring ink supplying slit.
[0023] A reinforcing bridge of a first ink supplying slit may not align with a reinforcing bridge of an adjacent ink supplying slit.
[0024] The foregoing and/or other aspects and utilities of the present invention can also be achieved by providing an ink cartridge usable in an image forming apparatus, the ink cartridge comprising an ink storing part, and a head chip disposed at a lower side of the ink storing part to discharge ink onto a recording medium, the head chip comprising a nozzle layer having a nozzle to discharge ink onto a recording medium, a substrate layer having at least one ink supplying slit provided to be parallel with the nozzle layer and supplies the nozzle with the ink, and at least one reinforcing bridge provided along an extending direction of the ink supplying slit and blocks at least one region of the ink supplying slit.
[0025] The ink storing part may be provided to correspond to a width of a printing medium and may comprise a plurality of head chips.
[0026] The foregoing and/or other aspects and utilities of the present invention can also be achieved by providing an ink cartridge usable in an image forming apparatus, the ink cartridge comprising an ink storing part, and a head chip coupled to the ink storing part, the head chip comprising a substrate, a plurality of ink supplying slits formed in the substrate, a chamber layer formed on the substrate and defining a plurality of ink chambers, a nozzle layer defining a plurality of nozzles to eject ink, an ink discharging device disposed in the ink chamber to provide an energy to eject ink from the ink chamber through the nozzles, and a plurality of reinforcing bridges disposed within the ink supplying slits to strengthen the head chip and prevent a deformation thereof when the head chip is coupled to the ink storing part.
[0027] Each of the plurality of reinforcing bridges may have a thickness equal or less than a thickness of the substrate.
[0028] The plurality of reinforcing bridges may be disposed in an alternating pattern with respect to adjacent ink supplying slits.
[0029] The plurality of reinforcing bridges may be disposed in an aligning pattern with respect to adjacent ink supplying slits.
[0030] A width of each reinforcing bridge may be p×2≦d≦p×6 and p may be a pitch between adjacent nozzles.
[0031] The ink cartridge may be a line printing type head cartridge and the head chip may comprise a plurality of head chips disposed along a length of the ink cartridge corresponding to a width of a printing medium.
[0032] The ink discharging device may be one of a piezoelectric device to apply a deformation pressure to the ink and a heater to heat the ink and generate bubbles in the ink to eject ink through the nozzles.
[0033] The foregoing and/or other aspects and utilities of the present invention can also be achieved by providing a reinforced head chip usable in an image forming apparatus, the head chip comprising a substrate having ink supplying slits formed thereon, a chamber layer formed on the substrate to define an ink chamber, a nozzle layer formed above the chamber layer to define a nozzle, an ink discharging device disposed in the ink chamber to provide an energy to eject ink from the ink chamber through the nozzles, and at least one reinforcing bridge provided in at least one ink supplying slit to strengthen the head chip and prevent a deformation thereof when the head chip is coupled to an ink storing part of an ink cartridge.
[0034] A height of the at least one reinforcing bridge may be equal or less than a height of the substrate where the reinforcing bridge is disposed.
[0035] A width of each reinforcing bridge may be p×2≦d≦p×6 and p may be a pitch between adjacent nozzles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] These and/or other aspects and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0037] FIG. 1 is an exploded perspective view illustrating a conventional ink cartridge;
[0038] FIG. 2A and FIG. 2B are sectional views illustrating the conventional ink cartridge of FIG. 1 before deformation and after deformation, respectively;
[0039] FIG. 3A and FIG. 3B illustrate a plan view and a sectional view, respectively, of a substrate layer of a head chip according to an exemplary embodiment of the present general inventive concept;
[0040] FIG. 4A and FIG. 4B are sectional views illustrating the head chip according to the exemplary embodiment of the present general inventive concept;
[0041] FIG. 5 is an expanded plan view illustrating a reinforcing bridge of the head chip according to an exemplary embodiment of the present general inventive concept;
[0042] FIG. 6A and FIG. 6B illustrate experimental results about a strength of the head chip according to an exemplary embodiment of the present general inventive concept; and
[0043] FIG. 7 is a plan view illustrating an ink cartridge according to an exemplary embodiment of the present general inventive concept.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present general inventive concept by referring to the figures.
[0045] FIG. 3A and FIG. 3B are a plan view and a sectional view, respectively, illustrating a substrate layer of a head chip according to an exemplary embodiment of the present general inventive concept. FIG. 4A is a sectional view illustrating the head chip of FIGS. 3A and 3B .
[0046] As illustrated in FIG. 3A , FIG. 3B , and FIG. 4A , an ink cartridge 100 according to the exemplary embodiment of the present general inventive concept may comprise an ink storing part 200 to store ink, and a head chip 300 which is provided at a lower side of the ink storing part 200 to discharge the ink from the ink storing part 200 onto a recording medium.
[0047] The ink storing part 200 may comprise an ink chamber (not illustrated) in which the ink is stored, a foam chamber (not illustrated) to discharge the ink into the head chip 300 by a predetermined negative pressure, and a partitioning wall (not illustrated) to separate the ink chamber (not illustrated) from the foam chamber (not illustrated). A connecting opening part (not illustrated) may be provided at a lower end part of the partitioning wall (not illustrated) to allow the ink to flow from the ink chamber (not illustrated) to the foam chamber (not illustrated).
[0048] A flexible printed circuit board (similar to FPCB 20 of FIG. 1 ) can be combined to a lower part of the ink storing part 200 to exchange an electrical signal with an image forming part main body (not illustrated) through a contact pad (similar to contact pad 21 of FIG. 1 ). The ink storing part 200 may store ink of one color or ink of a plurality of colors. That is, the ink storing part 200 may comprise only a black ink storing part, or may comprise a plurality of ink storing parts 200 to correspond to each color of yellow, magenta, cyan, black and/or other known ink colors, respectively.
[0049] The ink storing part 200 may be provided integrally with the head chip 300 . Alternatively, the head chip 300 may also be provided on the image forming apparatus main body (not illustrated) and only the ink storing part 200 may be detachably provided.
[0050] Since a structure of the ink storing part 200 is similar to that illustrated in FIG. 1 , a detailed description thereof is omitted.
[0051] As illustrated in FIG. 3A and FIG. 4A , the head chip 300 may comprise a substrate layer 310 having an ink supplying slit 311 having a reinforcing bridge 313 , a nozzle layer 330 having a nozzle 333 to discharge an ink droplet onto the recording medium, and a chamber layer 320 having an ink discharging device 321 to supply an energy to discharge the ink through the nozzle 333 .
[0052] The substrate layer 310 may comprise the ink supplying slit 311 which guides the ink in the ink storing part 200 to the nozzle layer 330 , and the reinforcing bridge 313 which is provided in the ink supplying slit 311 to partially block an ink supply and to reinforce a strength of the substrate layer 310 . The substrate layer 310 may be provided as a silicon wafer which is generally used in a manufacture of an integrated circuit.
[0053] The ink supplying slit 311 is filled with the ink, which is supplied from the ink storing part 200 , and supplies the ink to the chamber layer 320 . As illustrated in FIG. 3A , the ink supplying slit 311 can be provided to have a predetermined length l. The ink supplying slit 311 may be formed by etching a surface of a substrate 315 which is exposed through the nozzle 333 . Alternatively, the ink supplying slit 311 may be formed by etching the surface of the substrate 315 prior to formation of the nozzle layer 330 , or may be formed by etching a lower surface of the substrate 315 prior to coupling the substrate to the ink storing part 200 .
[0054] The ink supplying slit 311 may be provided as a single slit or may be provided plurally as illustrated in FIG. 3A . If the ink supplying slit 311 is provided plurally, each ink supplying slit 311 ( 311 M, 311 Y, 311 C, and 311 K in FIG. 3A ) may supply ink of the same color or ink of different color with respect to the other ink supplying slits 311 . For example, each ink supplying slit 311 Y, 311 M, 311 C, and 311 K may supply yellow, magenta, cyan, and black ink, respectively.
[0055] The reinforcing bridge 313 is provided at the ink supplying slit 311 to prevent a bending deformation of the substrate layer 310 , which may be generated when the head chip 300 is coupled with the ink storing part 200 . As illustrated in FIG. 4A , the reinforcing bridge 313 may partially block the ink supplying slit 311 and reinforces the substrate layer 310 so that the substrate layer 310 may not be deformed by a shear stress F which may be generated by a difference in coefficients of thermal expansion between materials of the substrate 315 and the ink storing part 200 . As a length of a part of the ink supplying slit 311 where the bending deformation may occur is decreased due to the reinforcing bridge 313 , a maximum bending deformation amount may also be decreased.
[0056] For example, a thickness h 1 of the reinforcing bridge 313 may be provided not to be greater than a thickness h of the substrate 315 . That is, the thickness h 1 of the reinforcing bridge 313 may be provided to be smaller than the thickness h of the substrate 315 as illustrated in FIG. 4A or a thickness h 2 may be provided same as the thickness h of the substrate 315 as illustrated in FIG. 4B . The ink, which surrounds the reinforcing bridge 313 , may be more easily supplied to the chamber layer 320 when the thickness h 1 of the reinforcing bridge 313 is provided to be smaller than the thickness h of the substrate 315 than when the thickness h 2 of the reinforcing bridge 313 is provided to be the same as the thickness h of the substrate 315 .
[0057] However, the amount of the deformation which is generated if the ink storing part 200 is combined with the head chip 300 is small when the thickness h 2 of the reinforcing bridge 313 is provided to be the same as the thickness h of the substrate 315 . Therefore, the thickness of the reinforcing bridge 313 may be provided properly by considering the ink supply to the nozzle 333 and the amount of the deformation of the substrate layer 310 .
[0058] On the other hand, a width d of the reinforcing bridge 313 may be provided not to obstruct the flow of the ink which is supplied to the nozzle 333 . Experimentally, as illustrated in FIG. 5 , the width d of the reinforcing bridge 313 may be 2 to 6 times as large as a distance p between adjacent nozzles 333 . If the width d of the reinforcing bridge 313 is smaller than twice the distance p, the ink may not be smoothly supplied to the nozzle 333 which surrounds the reinforcing bridge 313 . Also, if the width d of the reinforcing bridge 313 is larger than six times the distance p, the ink may not be smoothly supplied to the nozzle 333 which is disposed at a center of the plurality of the nozzles 333 surrounding the reinforcing bridge 313 .
[0059] Also, if a distance between adjacent reinforcing bridges 313 provided at the ink supplying slit 311 is small, deformation of the substrate layer can be reduced. However, the small distance between adjacent reinforcing bridges 313 may be an influence upon the smooth supply of the ink. Therefore, the distance between adjacent reinforcing bridges 313 may be properly provided by considering a width w and the thickness h of the ink supplying slit 311 .
[0060] The reinforcing bridge 313 may be provided at each of the plurality of the ink supplying slits 311 . In this case, as illustrated in FIG. 3A , the reinforcing bridges 313 may be provided in an alternating pattern so as to not align with a reinforcing bridge of an adjacent ink supplying slit 311 . For example, as illustrated in FIG. 3A , reinforcing bridge 313 A of ink supplying slit 311 Y is provided to alternate with reinforcing bridges 313 of the ink supplying slit 311 M. Alternatively, as illustrated in FIG. 6A , the reinforcing bridges 313 may be provided to align with reinforcing bridges 313 B which are provided at an adjacent ink supplying slit 311 .
[0061] The reinforcing bridge 313 may be formed by not etching a part of the substrate 315 to correspond to the thickness h 1 and the width d of the reinforcing bridge 313 when the substrate 315 is etched to form the ink supplying slit 311 . In this case, the reinforcing bridge 313 is provided integrally with the substrate 315 . Alternatively, the reinforcing bridge 313 may be provided by attaching an additional member in the ink supplying slit 311 formed by etching.
[0062] The chamber layer 320 may comprise the ink discharging device 321 which supplies the ink with the energy to discharge the ink through the nozzles 333 , which is supplied through the ink supplying slit 311 , onto the recording medium, and a chamber wall 323 which accommodates the ink discharging device 321 . In this case, the ink discharging device 321 may be provided as a piezoelectric device or an electricity-heat transforming device, such as a heater. The chamber wall 323 can be made of epoxy resin. However, the chamber wall 323 may also be made of a photoresist resin of a silicon base, an acryl base, or an imide base.
[0063] An electrode 340 can be provided at an outer side of the chamber layer 320 to apply a current to the ink discharging device 321 . The electrode 340 may be made of aluminum or aluminum alloy which has a superior conductivity and may be easily patterned. Additionally, the electrode 340 can be provided as a layer formed over the ink discharging device 321 to supply a current thereto.
[0064] The nozzle layer 330 may comprise the plurality of the nozzles 333 to discharge ink by the energy supplied by the ink discharging device 321 of the chamber layer 320 . In this case, the more nozzles 333 that are provided, the more a printing quality is improved. Therefore, the nozzles 333 may be provided to be disposed in their maximum number per unit area.
[0065] Hereinafter, an operating process of the ink cartridge 100 according to the present general inventive concept is described. First, the ink which is supplied from the ink storing part 200 flows through the ink supplying slit 311 of the substrate layer 310 and into the chamber layer 320 . The ink which fills the chamber layer 320 is discharged to the outside through the nozzle 333 by the energy supplied by the ink discharging device. For example, by an abrupt heating or vibration of the ink discharging device 321 . That is, if the ink discharging device 321 is heated, an ink bubble is generated in the ink in the chamber layer 320 . Then, the generated bubble pushes the ink via an expanding force of the bubble, so that the ink can be discharged through the nozzle 333 .
[0066] FIG. 6B illustrates an experimental result of an analysis through ANSYS on the deformation amount of the substrate layer 310 when the shear stress F of 20 [MPa] is applied to the head chip 300 of the ink cartridge 100 according to the present general inventive concept.
[0067] According to the experimental result, when there is no reinforcing bridges, the maximum deformation amount of the ink supplying slit 311 of the substrate layer 310 was 6.57 [μm]. On the other hand, as illustrated in FIG. 6A , in the head chip 300 according to the present general inventive concept having five reinforcing bridges 313 each with a respective width of 84 [μm] for each ink supplying slit 311 , the maximum deformation amount due to the same shear stress F was estimated to be 0.276 [μm]. Therefore, it can be seen that a hardness of the head chip 300 according to the present general inventive concept is increased by about 24 times as much as that of the head chip lacking reinforcing bridges.
[0068] As described above, as the head chip according to embodiments of the present general inventive concept and the ink cartridge having the head chip comprise the plurality of the reinforcing bridges in the ink supplying slit, the bending deformation, which is generated when the ink storing part is combined with the head chip, can be minimized.
[0069] Also, as described above, the bending deformation of the head chip can be minimized by the reinforcing bridge, so that an ink discharging direction can be uniformly maintained, thus enhancing the printing quality.
[0070] Also, as a degree of the bending deformation is small, a surface of the nozzle can be maintained undamaged during a wiping process.
[0071] In the above description, the ink cartridge according to the exemplary embodiment of the present general inventive concept is a shuttle type ink cartridge which comprises only one head chip. However, the present general inventive concept is not limited thereto, and as illustrated in FIG. 7 , the ink cartridge according to the present general inventive concept is applicable to a line head type ink cartridge with a width that corresponds to a width of the printing medium and comprising a plurality of the head chips.
[0072] As described above, according to the present general inventive concept, the head chip and the ink cartridge, where the bending deformation of the substrate layer can be minimized, may be provided by having the reinforcing bridge in the ink supplying slit to reinforce the strength of the substrate layer.
[0073] Although a few exemplary embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
|
A head chip usable in an image forming apparatus, the head chip includes a nozzle layer having a nozzle to discharge ink onto a recording medium, a substrate layer having an ink supplying slit provided to be parallel with the nozzle layer to supply the nozzle with the ink, and a reinforcing bridge provided along an extending direction of the ink supplying slit and blocks at least one region of the ink supplying slit.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to novel liquid crystalline compounds and liquid crystalline mixtures containing the same, and more particularly, it relates to chiral smectic compounds which have a high response rate and are superior as a ferroelectric liquid cyrstalline material, and also to chiral smectic mixtures containing the same.
2. Description of the Prior Art
Twisted nematic (TN) type display mode has currently been most widely employed as liquid crystal display elements, but it is inferior in the response rate as compared with emissive type display elements such as electroluminescence, plasma display, etc., and various attempts for overcoming this drawback have been made, but, nevertheless, it seems that its improvement to a large extent has not been left behind. Thus, various liquid crystal display equipments based on different principles in place of TN type display elements have been attempted, and as one of them, there is a display mode utilizing ferroelectric liquid crystals (N. A. Clark and S. T. Layerwall, Applied Phys. lett., 36,899 (1980)). This mode utilizes the chiral smectic C phase (hereinafter abbreviated to SC* phase) or chiral smectic H phase (hereinafter abbreviated to SH* phase) of ferroelectric liquid crystals. As such ferroelectric liquid crystal compounds, the following compounds (1) to (4) have been known up to the present (ph. Martino Lagarde, J. de Physique, 37, C3-129 (1976)): ##STR7##
In the foregoing, C represents crystalline phase; SA, smectic A phase; I, isotropic liquid phase; SC* and SH*, as described above; and "*", asymmetric carbon atom.
Further, as ferroelectric liquid crystal compounds, the following two compounds (5) and (6) have also been known: ##STR8##
(B. I. Ostrovski, A. Z. Rabinovich, A. S. Sonin, E. L. Sorkin, B. A. Strukov, and S. T. Taraskin; Ferroelectrics, 24, 309 (1980)).
Among these compounds, since the compounds (1) to (4) have C═C double bond and azomethine group, they have drawbacks of being inferior in light resistance and water resistance. The compounds (5) also have azomethine group and hence are inferior in water resistance. The compounds (6) do not have these bonds and hence are superior in stability, but the above Ostrovski et al's article discloses as to their phase transition temperatures, only that the upper limit temperatures of SC* phase are 324.8° K. (in the case of n=9) and 326.2° K. (in the case of n=10), but nothing is disclosed therein as to other liquid crystalline phase modifications.
The present inventors have investigated and studied various compounds including the above compounds (1) to (6) and as a result, have found ferroelectric liquid crystal compounds having a superior stability.
SUMMARY OF THE INVENTION
The present invention resides in:
compounds expressed by the general formula ##STR9## wherein ##STR10## represents 1,4-phenylene group ##STR11## or 1,4-trans-cyclohexane group ##STR12## R*, an optically active alkyl group; m=o, 1 or 2; n=1 or 2; X, a linear chain or branched alkyl group or alkoxy group, each having 1 to 18 carbon atoms; and when ##STR13## represents ##STR14## m=1; and n=1, X represents a linear chain or branched alkyl group having 1 to 18 carbon atoms or a linear chain alkoxy group having 11 to 18 carbon atoms, and chiral smectic liquid crystalline compositions containing at least one kind of the same.
The compounds of the above formula (I) include those exhibiting SC* phase, alone, those exhibiting SC* phase and SA phase, those exhibiting three phases of SC* phase, SA phase and Ch phase (cholesteric phase), those exhibiting SA phase and Ch phase, etc., that is, they are a group of compounds exhibiting physically very diversified liquid crystalline phases.
DETAILED DESCRIPTION OF THE INVENTION
As for the R* in the above formula (I), i.e. optically active alkyl group, currently commercially readily available compounds containing the group, as raw material, are optically active 2-methylbutyl alcohol in the first place and optically active 2-octanol in the second place; thus 2-methylbutyl group and 2-octyl group are suitable as the group.
Among the compounds of the present invention, particularly important compounds are those which exhibit SC* phase suitable for displays using ferroelectric liquid crystals. Namely, compounds corresponding to the above are those of the formula (I) wherein R* is 2-methylbutyl; ##STR15## m=1; n=2; and X represents a linear chain alkyl group or alkoxy group. These compounds do not exhibit SA phase at higher temperatures than those at which SC* phase having ferroelectric properties is existent, but exhibit chloesteric phase (Ch phase). This is particularly preferably when they are employed for display elements using ferroelectric liquid crystals. A reason thereof is that when display elements are produced, liquid crystals are aligned in cholesteric state and then cooled; hence it is possible to directly form SC* phase not via other phases, to thereby easily obtain an aligned liquid crystalline phase having a high uniformity. Another reason is that rather in the case where SA phase is absent at higher temperatures than those at which SC* phase is existent, than in the case where SA phase is present at the above higher temperatures, the temperature change in the direction of the helical axis of SC* phase is small to thereby reduce the temperature change in the contrast of displays, down to a negligible small extent.
On the other hand, compounds of the formula (I) wherein ##STR16## have a strong tendency of exhibiting SA phase in place of SC*.
On the other hand, compounds of the formula (I) wherein m is zero have drawbacks that temperatures at which they exhibit SC* phase are within a lower and narrower temperature range as compared with compounds of the formula (I) wherein m is 1 or 2, but since the former compounds also have lower melting point, they are effective for lowering the freezing points of SC* liquid crystalline compositions and also extending the lower limits of SC* liquid crystalline temperature ranges.
Further, compounds of the formula (I) wherein m is 1; ##STR17## and n is 1, also have generally rather lower temperatures and are suitable as a component of liquid crystalline compositions exhibiting a liquid crystalline state in the vicinity of room temperature. Further, compounds of the formula (I) wherein m is 2; ##STR18## and n is 1, have relatively high melting points as compared with the above compounds wherein m is 1 and others are the same as above, but they also have a specific feature of exhibiting a liquid crystalline phase up to high temperatures and hence are suitable for extending the upper limits of the temperature ranges of liquid crystalline compositions. Furthermore, compounds of the formula (I) wherein m is 1 and others are the same as above have cholesteric phase when X═C 7 H 15 O or lower and compounds of the formula (I) wherein m is 2 and others are the same as above have the phase when X═C 3 H 7 O or lower; hence by suitably mixing these compounds, it is possible to easily obtain liquid crystalline compositions having cholesteric phase on the higher temperature side of smectic phase and also exhibiting SC* phase in the vicinity of room temperature.
When SC* liquid crystalline compositions are formed, it is possible to form them from a plurality of compounds of the formula (I), alone, and it is also possible to prepare liquid crystalline compositions exhibiting SC* phase, by mixing compounds of the formula (I) with other smectic liquid crystals.
When the light switching effect of the SC* phase is applied to display elements, the resulting display elements have the following three superior specific features:
The first specific feature is that the elements reply at a very high rate and the response times are 1/100 or less of those of display elements according to the usual TN display mode.
The second specific feature is that the elements have a memory effect; hence multiplex drive is easy in combination of this effect with the above-mentioned high rate response properties.
The third specific feature is that gray scale in TN display mode is attained by controlling the impressed voltage applied to display elements, but this is accompanied with difficult problems of the temperature depency of threshold voltage value and the voltage dependency of response rate. However, in the case where the light switching effect of SC* phase is applied to the display elements, it is possible to easily attain the gray scale by controlling the switching time of polarity; hence the display elements are very suitable for graphic display.
As for the display modes, the following two may be considered:
One mode is of birefringence type using two pieces of polarizers and another is of guest-host type using dichloric dyestuffs. Since SC* phase has a spontaneous polarization, molecules reverse around the helical axis thereof as a revolving axis by reversing the polarity of impressed voltage. A liquid crystal composition having SC* phase is filled into a liquid crystal display cell subjected to an aligning treatment so that liquid crystal molecules can align in parallel to the surface of electrodes, followed by placing the liquid crystal cell between two pieces of polarizers arranged so that the director of the liquid crystal molecules can be in parallel to the polarization plane on another side, impressing a voltage and reversing the polarity to be thereby able to obtain a bright field and a dark field (determined by the opposed angles of polarizers). On the other hand, in the case where display elements are operated in guest-host mode, it is possible to obtain bright field and colored field (determined by the arrangement of polarization sheets) by reversing the polarity of impressed voltage.
In general, it is difficult to align liquid crystal molecules in smectic state in parallel to the wall surface of glass; hence liquid crystal molecules have been aligned by cooling them very slowly (e.g. 1°˜2° C./hr) initially starting from their isotropic liquid, in a magnetic field of several tons Kilogauss or more, but in the case of liquid crystal substances having cholesteric phase, the substances are cooled at a cooling rate of 1° C./min. under impression of a direct current voltage of 50 to 100 V in place of magnetic field, whereby it is possible to easily obtain a monodomain state where liquid crystal molecules are uniformly aligned.
Compounds of the formula (I) also have an optically active carbon atom; hence when they are added to nematic liquid crystals, they have a performance of having a twisted structure induced in the mixtures. Nematic liquid crystals having a twisted structure, i.e. chiral nematic liquid crystals, form no reverse domain (striped pattern); hence it is possible to use the compounds of the formula (I) as an agent for preventing reverse domain. Compounds suitable for such an application field are those which by themselves exhibit cholesteric phase, and examples thereof are compounds of the formula (I) wherein R* represents 2-methylbutyl; ##STR19## m, 1;n, 2; and X, an alkoxy group having 4 carbon atoms or less in the main chain, and compounds of the formula (I) wherein n represents 1; X, an alkoxy group of 8 carbon atoms or less; and the remaining symbols, the same as above. When these compounds are added to nematic liquid crystals in an amount of about 0.05 to 3% by weight based on the latter, a twisting force in the definite direction is imparted to molecules so that the resulting nematic liquid crystals are free from the reverse domain.
Compounds of the formula (I) wherein m=1 or 2; ##STR20## and n=1 may be prepared according to such steps as described below. The compounds may be most suitably prepared by first reacting hydroquinonemono (optically active 2-methylbutyl) ether with a corresponding carboxylic acid halide such as p-alkoxybenzoic acid halides, 4-(p-alkoxyphenyl)-benzoic acid halides, 4-(p-alkylphenyl)benzoic acid halides, trans-4-alkylcyclohexanecarboxylic acid halides, trans-4-alkoxycyclohexanecarboxylic acid halides, etc., in a basic solvent such as pyridine. The hydroquinonemono (optically active 2-methylbutyl) ether may be prepared from hydroquinone and optically active 2-methylbutyl halide or optically active 2-methylbutyl-p-toluenesulfonic acid ester according to a conventional method.
Compounds of the formula (I) wherein m=0,1 or 2; ##STR21## and n=2 may be prepared according to such steps as described below. The compounds may be prepared by first mono-etherifying 4,4'-dihydroxybiphenyl with an optically active alkylhalide or an optically active alkyl p-toluenesulfonic acid ester according to a conventional method to obtain a 4,4'-dihydroxydiphenyl monoether ##STR22## which is then reacted with fatty acid halide, chloroformic acid ester, p-alklybenzoic acid halide, p-alkoxybenzoic acid halide, trans-4-alkylcyclohexanecarboxylic acid halide, 4'-alkyl-4-biphenylcarboxylic acid halide, 4'-alkoxy-4-biphenylcarboxylic acid halide or the like, corresponding to the respective final objective compounds, in a basic solvent represented by pyridine to obtain the objective products.
Liquid crystal compounds and liquid crystal compositions of the present invention will be further described in detail by way of Examples.
EXAMPLE 1
Preparation of p-n-dodecyloxybenzoic acid-p'-(2-methylbutyloxy)phenyl ester (compounds of the formula (I) wherein m=1; ##STR23## n=1; R*=2-methylbutyl; and X═n--C 12 --H 25 O) (I) Preparation of optically active hydroquinonemono (2-methylbutyl)ether
Optically active p-toluenesulfonic acid 2-methylbutyl ester was first prepared according to a conventional method i.e. by reacting p-toluenesulfonic acid chloride with (-)2-methylbutanol in pyridine.
Next, into a solution obtained by dissolving hydroquinone (248 g) and potassium hydroxide (88 g) in water (30 ml) and ethanol (2 l) was added the above p-toluenesulfonic acid 2-methylbutyl ester (366 g) and the mixture was heated with stirring at 60° C. for 2 hours and then under reflux for 7 hours, followed by distilling off ethanol (1.7 l), adding water (1.9 l) and 6N hydrochloric acid for acidification to separate a brown oily substance, extracting this substance with heptane (150 ml), water-washing the resulting heptane layer, distilling it under reduced pressure to obtain a fraction of b.p. 115°˜135° C.(2.5 mmHg) (176 g), dissolving this fraction in heptane (300 ml), subjecting the solution to extraction with 1N aqueous solution of KOH (1 l), washing the resulting extract liquid with heptane (100 ml), adding 6N hydrochloric acid to the alkaline aqueous layer for acidification to separate an oily substance, water-washing this substance, and distilling it under reduced pressure to obtain a fraction of b.p. 107°˜111° C. (2 mmHg) (140 g), dissolving this fraction in hexane (200 ml), and keeping the solution at 0° C. for crystal deposition to obtain optically active hydroquinonemono (2-methylbutyl) ether (m.p. 41°˜42° C.) (129 g).
(II) Esterification
p-n-Dodecyloxybenzoic acid (8 g) together with thionyl chloride (20 ml) were heated under reflux for 2 hours, followed by distilling off excess thionyl chloride to obtain p-n-dodecyloxybenzoic acid chloride, which was made up into a toluene solution thereof without any particular purification. On the other hand, optically active hydroquinonemono (2-methylbutyl) ether (4.7 g) obtained above in the item (I) was dissolved in pyridine (30 ml). To this solution kept at 0° C. was dropwise added the toluene solution of p-n-dodecyloxybenzoic acid chloride obtained above, followed by heating the mixture at 90° C. for 2 hours for reaction, separating the resulting esterified substance in a conventional manner, and twice repeating recrystallization to obtain colorless crystals of p-n-dodecyloxybenzoic acid p'-(2-methylbutyloxy)phenyl ester (C-SC* point, 50.5° C.; SC*-SA point, 51.2° C.; SA-I point, 65° C.; and [α] D 25 ° =+5.2° (as measured in chloroform solution)) (6.5 g). Further its elemental analysis values accorded well with its theoretical values as follows:
______________________________________ Theoretical values Analytical values (as C.sub.30 H.sub.44 O.sub.4)______________________________________C 76.6% 76.88%H 9.6% 9.46%______________________________________
EXAMPLES 2-21
Compounds of the formula (I) wherein m=1 or 2; ##STR24## and n=1 were prepared as in Example 1 except that p-n-dodecyloxybenzoic acid chloride was replaced by various kinds of p-alkyloxybenzoic acid chlorides, 4'-alkyl-4-biphenylcarboxylic acid chlorides, or 4'-alkyloxy-4-biphenylcarboxylic acid chlorides. The physical properties of the compounds obtained are shown together with the results of Example 1 in Table 1. In addition, R* of the formula (I) in this Table all refers to optically active 2-methylbutyl group.
TABLE 1__________________________________________________________________________In formula (I) Ex. X ##STR25## m n Phase transition point (°C.) CS.sub.3SC*SAChI__________________________________________________________________________ 2 n-C.sub.4 H.sub.9 O ##STR26## 1 1 . 77 -- -- -- (. 40)* . 3 n-C.sub.6 H.sub.13 O " 1 " . 63 -- -- (. 45.5) (. 53.5) . 4 n-C.sub.7 H.sub.15 O " 1 " . 53 -- -- (. 48) (. 52) . 5 n-C.sub.8 H.sub.17 O " 1 " . 47.1 -- (. 42.7) .sup. . 58.5 -- . 6 n-C.sub.9 H.sub.19 O " 1 " . 45 -- . 47 .sup. . 59 -- . 7 n-C.sub.10 H.sub.21 O " 1 " . 45.5 -- . 50 .sup. . 63 -- . 8 n-C.sub.11 H.sub.23 O " 1 " . 48 -- . 50 .sup. . 63 -- . 1 n-C.sub.12 H.sub.25 O " 1 " . 50.5 -- . 51.2 .sup. . 65 -- . 9 n-C.sub.13 H.sub.27 O " 1 " . 59 -- (. 50) .sup. . 66 -- .10 n-C.sub.14 H.sub.29 O " 1 " . 56 -- -- .sup. . 65 -- .11 n-CH.sub.3 O " 2 " . 120 -- -- .sup. . 164 . 213.5 .12 n-C.sub.3 H.sub.7 O " 2 " . 133.5 -- -- .sup. . 173 . 183 .13 n-C.sub.6 H.sub.13 O " 2 " . 111.5 -- (. 91.5) .sup. . 196 -- .14 n-C.sub.7 H.sub.15 O " 2 " . 103 . 106 . 116 .sup. . 182.5 -- .15 n-C.sub.8 H.sub.17 O " 2 " . 102.5 -- . 150 .sup. . 189 -- .16 n-C.sub.9 H.sub.19 O " 2 " . 99 -- . 157 .sup. . 186 -- .17 n-C.sub.10 H.sub.21 O " 2 " . 95.5 . 99 . 152 .sup. . 182 -- .18 n-C.sub.12 H.sub.25 O " 2 " . 90 -- . 150 .sup. . 175 -- .19 n-C.sub.18 H.sub.37 O " 2 " . 100 -- . 128 .sup. . 153 -- .20 n-C.sub.7 H.sub.15 " 2 " . 96 -- -- .sup. . 161.5 -- .21 n-C.sub.8 H.sub.17 " 2 " . 88 -- -- .sup. . 157 -- .__________________________________________________________________________
In the column of "phase transition point" of the above Table, S 3 represents a smectic phase whose identity is unclear; "." and numeral figures on the right side of "." represent the temperature of phase transition from the phase corresponding thereto to a phase on the right side of the above phase; "-" means that the phase is not exhibited; "()" represents a monotropic phase transition temperature; and "*" represent approximate values obtained by extrapolation method.
EXAMPLE 22 (USE EXAMPLE 1)
A liquid crystal composition consisting of
______________________________________4-ethyl-4'-cyanobiphenyl 20 parts by weight4-pentyl-4'-cyanobiphenyl 40 parts by weight4-octyloxy-4'-cyanobiphenyl 25 parts by weight4-pentyl-4'-cyanoterphenyl 15 parts by weight______________________________________
was filled in a cell consisting of transparent electrodes (distance therebetween: about 10 μm) subjected to parallel aligning treatment by applying polyvinyl alcohol thereonto and rubbing the resulting surface to prepare a TN type display cell, and when this cell was observed with a polarizing microscope, formation of a reverse domain was observed.
To the above nematic liquid crystal composition was added a compound of the formula (I) wherein m=1; ##STR27## n=1; X=C 8 H 17 O; and R*=2-methylbutyl, in an amount of 0.1% by weight. From this mixture was similarly prepared a TN cell, which was then observed, and as a result it was observed that the reverse domain disappeared and a uniform nematic phase was exhibited.
EXAMPLE 23 (USE EXAMPLE 2)
Compounds of the formula (I) wherein m=1; ##STR28## n=1; R* is 2-methylbutyl; and X=n--C 8 H 17 O, n--C 9 H 19 O, n--C 10 H 21 O, n--C 12 H 25 O, or n--C 14 H 29 O were respectively mixed in equal amount. The mixtures exhibited SC* phase up to 40° C., exhibited SA phase at higher temperatures than 40° C. and this SA phase became an isotropic liquid at 62° C. directly, not via cholesteric phase.
Each of the mixtures was filled in a cell subjected to aligning treatment by applying an oblique evaporation of silica onto the surfaces of the electrodes to align liquid crystal molecules in parallel to the surfaces of the electrodes (the distance therebetween: 10 μm). The resulting cell was placed between polarizers in a perpendicularly crossed Nicol state, arranged so that the director of liquid crystal molecules could be in parallel to a polarization plane on another side, and an alternating current voltage of low frequency (0.5 Hz, 5 V) was impressed. As a result, a clear switching effect was observed, and liquid crystal display elements having a very good contrast and a high response rate (several m sec) were obtained.
EXAMPLE 24 (USE EXAMPLE 3)
Five compounds of the formula (I) wherein m=1; ##STR29## n=1; R*=2-methylbutyl; and X=n--C 8 H 17 O, n--C 11 H 23 O, n--C 12 H 25 O, n--C 13 H 27 O or n--C 14 H 29 O (the respective weights of these compounds being 4 parts, 4 parts, 4 parts, 4 parts and 3 parts) were mixed with three compounds of the formula (I) wherein m=2; ##STR30## n=1; R*=2-methylbutyl; and X=n--C 8 H 17 O, n--C 10 H 21 O or n--C 12 H 25 O (the respective weights of these compounds being one part, 2 parts and one part). Each of these mixtues exhibited SC* phase up to 45° C., exhibited SA phase above 45° C. and became an isotropic liquid at 80°˜82° C. directly not via cholesteric phase.
To this mixture was added a dyestuff of anthraquinone group, D-16 (a product of BDH company) in an amount of 3% by weight to prepare a composition of the so-called guest-host type. This was then filled in the same cell as in Example 3, and one piece of a polarizer was so arranged that its polarization plane was perpendicular to the axis of molecules. When an alternating current (0.5 Hz, 5 V) was impressed, a clear switching effect was observed and a color liquid display element having a very good contrast and a high response rate (several m sec) was obtained.
EXAMPLE 25 (USE EXAMPLE 4)
A mixture of a compound of the formula (I) wherein m=1; ##STR31## n=1; R*=2-methylbutyl; and X=n--C 8 H 17 O (85 parts), with a compound of the formula (I) wherein m=2; ##STR32## n=1; R*=2-methylbutyl; and X=n--C 6 H 13 O (15 parts), exhibited SC* phase up to 43° C., exhibited SA phase at temperatures above 43° C., and this SA phase turned to cholesteris phase (Ch phase) at 57° C. and became an isotropic phase at 74° C.
This mixture was filled in a cell provided with transparent electrodes subjected to parallel aligning treatment by applying PVA onto the surfaces of electrodes and rubbing the resulting surfaces, and while a direct current voltage of 50 V was impressed to the cell in the temperature range exhibiting Ch phase, it was slowly cooled till it exhibited SC* phase, to obtain a uniform monodomain cell. When this liquid crystal cell was placed between two pieces of polarizers arranged so as to give a perpendicularly crossed Nicol state, and an alternating current voltage of low frequency (15 V, 0.5 Hz) was impressed to the cell, a clear switching effect was observed and a color liquid crystal element having a very good contrast and a high response rate (1 m sec or less).
In addition, the value of the spontaneous polarization of this liquid crystal composition, P s was 3 nC/cm 2 .
EXAMPLE 26 (Use Example 5)
Four compounds of the formula (I) wherein m=1; ##STR33## n=1; R*=2-methylbutyl; and X=n--C 8 H 17 O, n--C 9 H 19 O, n--C 10 H 21 O or n--C 12 H 25 O (each 20% by weight) were mixed with two compounds of the formula (I) wherein m=2; ##STR34## n=1; R*=2-methylbutyl; and X=n--C 6 H 13 O or n--C 8 H 17 O (each 10% by weight). The resulting mixture exhibited SC* phase up to 51° C., exhibited SA phase at temperatures above 51° C., and this SA phase became an isotropic liquid at 75° C. directly not via cholesteric phase.
This mixture was filled in the same cell as in Use Example 3, and the resulting cell was placed between two pieces of polarizers arranged to as to give a perpendicularly crossed Nicol state, and when an alternate current of 15 V and low frequency (0.5 Hz) was impressed, a clear switching effect was observed and a liquid crystal display element having a very good contrast and a high response rate (1 m sec or less) was obtained.
In addition, its P s value was 2 nC/cm 2 and its tilt angle was 20° in the range of 20° C.˜40° C.
EXAMPLE 27 (USE EXAMPLE 6)
A liquid crystal composition consisting of a compound of the formula (I) wherein m=1; ##STR35## n=1; R*=2-methylbutyl; and X=C 8 H 17 O (one part) and as other smectic compounds, ##STR36## exhibited SC* phase up to 70° C., exhibited Ch phase above 70° C. and became an isotropic liquid at 105° C. That is, it is a composition exhibiting no SA phase. To this liquid crystal composition was added a dyestuff of anthraquinone group, D-16 (made by BDH company), in an amount of 3% by weight to prepare a liquid crystal composition of the so-called guest-host type. This composition was filled in the same as in Example 25, and while a direct current voltage of 50 V was impressed in the temperature range of Ch phase, the cell was slowly cooled, to obtain a uniform monodomain. This liquid crystal cell was provided with two pieces of polarizers arranged so that the polarization plane could be perpendicular to the axis of molecules, and when an alternating current voltage of 15 V and low frequency (0.5 Hz) was impressed, a clear switching effect was observed and a liquid crystal display element having a very good contrast and a high response rate (1 m sec or less) was obtained.
EXAMPLE 28
Preparation of 4'-(2-methylbutyloxy)-4-n-pentanoyloxybiphenyl (a compound of the formula (I) wherein m=0; ##STR37## n=2; R*=2-methylbutyl; and X=n--C 4 H 9 )
(i) Preparation of 4'-(2-methylbutyloxy)-4-hydroxybiphenyl
A mixture of 4,4'-dihydroxybiphenyl (500 g), ethanol (7.5 l) and KOH (302 g) was heated under reflux with stirring, and (+) 2-methylbutyl bromide (prepared from (-)2-methylbutanol with phosphorus bromide) (530 g) was dropwise added for 4 hours to react them, followed by distilling off ethanol, adding water (2 l), filtering, collecting an insoluble substance, and treating this insoluble substance with toluene to remove a soluble substance. This soluble part was recrystallized from ethanol to give scaly crystals of m.p. 80.5° C., which was confirmed to be di-(2-methylbutyloxy)-biphenyl. On the other hand, the above insoluble part was heated together with hydrochloric acid with stirring, followed by cooling, collecting the resulting solid substance and recrystallizing it from toluene and then from ethanol to obtain 4'-(2-methylbutyloxy)-4-hydroxybiphenyl of m.p. 137.5° C. (125 g).
(ii) Preparation of subject compound
4'-(2-Methylbutyloxy)-4-hydroxybiphenyl (5.1 g) obtained above in the item (i) was dissolved in pyridine and cooled with water. To this solution was dropwise added with stirring a toluene solution of valeic acid chloride (2.5 g), followed by reacting them at 60° C. for one hour, adding ice and 6N hydrochloric acid for acidification, washing with water, distilling off toluene, and recrystallizing the residue from ethanol to obtain the objective 4'-(2-methylbutyloxy)-4-n-pentanoyloxybiphenyl (4.2 g) having a m.p. of 86° C., which exhibited SB phase through monotropic phase transition at 85° C. (see Table 2). Its chemical structure was confirmed by NMR and elemental analyses.
EXAMPLES 29-46
Example 28 was repeated except that valeic acid chloride was replaced by various kinds of fatty acid chlorides, chloroformic acid alkyl, p-alkylbenzoic acid chloride, p-alkyloxy benzoic acid chloride, trans-4-alkylcyclohexanecarboxylic acid chloride, 4'-alkyl-4-biphenylcarboxylic acid chloride or 4'-alkyloxy-4-biphenylcarboxylic acid chloride, to obtain compounds of the formula (I) wherein m=0, 1 or 2; n=2; and ##STR38## The physical properties of these compounds are shown in Table 2 together with the results of Example 28.
TABLE 2__________________________________________________________________________In formula (I) Example X R* ##STR39## m n Phase transition point (°C.)CSBSC*SAChI__________________________________________________________________________28 n-C.sub.4 H.sub.9 2-methylbutyl group -- 0 2 . 86 . 85 -- -- -- .29 n-C.sub.6 H.sub.13 O " -- 0 " . 49 -- (. 46) -- -- .30 n-C.sub.8 H.sub.17 O " -- 0 " . 55 -- (. 47) -- (. .9.5)31 n-C.sub.9 H.sub.19 O " -- 0 " . 59 -- (. 46) -- (. .9)32 n-C.sub.5 H.sub.11 " ##STR40## 1 " . 99.5 -- (. 91) -- . .933 n-C.sub.7 H.sub.15 " " 1 " . 80 -- . 97.5 -- . .6634 n-C.sub.8 H.sub.17 " " 1 " . 85.5 -- . 105 -- . .51.535 n-C.sub.10 H.sub.21 " " 1 " -- unclear -- . 109 -- . .49.536 n-C.sub.4 H.sub.9 O " " 1 " . 113 -- -- -- . .4137 C.sub.2 H.sub.5 *CH(CH.sub.3)CH.sub.2 O " " 1 " . 105 -- -- -- . .9538 n-C.sub.7 H.sub.15 O " " 1 " . 83 -- . 122 -- . .48.539 n-C.sub.8 H.sub.17 O " " 1 " . 81 -- . 130.5 -- . .7540 n-C.sub.9 H.sub.19 O " " 1 " . 82 -- . 125 -- . .6041 n-C.sub.16 H.sub.33 O " " 1 " . 90.5 -- . 132 -- . .4242 n-C.sub.8 H.sub.17 " ##STR41## 1 " . 84.5 -- -- . 160.5 . .67.543 n-C.sub.8 H.sub.17 O " ##STR42## 2 " . 142 -- . 229 . 251 . .8144 n-C.sub.8 H.sub.17 2-octyl group ##STR43## 1 " . 63.2 -- . 68.2 -- . .1.745 n-C.sub.8 H.sub.17 O " " 1 " . 72.1 . 68.5 . 100.6 -- . .25.446 n-C.sub.8 H.sub.17 " ##STR44## 1 " -- . 109.4 -- . 110.7 -- .__________________________________________________________________________ SB shows smectic B phase.
EXAMPLE 47 (USE EXAMPLE 7)
A composition consisting of
______________________________________4-ethyl-4'-cyanobiphenyl 20 parts by weight4-pentyl-4'-cyanobiphenyl 40 parts by weight4-octyloxy-4'-cyanobiphenyl 25 parts by weight and4-pentyl-4'-cyanoterphenyl 15 parts by weight______________________________________
was filled in a TN cell of transparent electrodes (the distance therebetween: about 10 μm) subjected to parallel aligning treatment by applying PVA and rubbing the surfaces, and when it was observed with a polarizing microscope, a reverse domain was observed.
To this composition was added a compound of the formula (I) wherein m=0; ##STR45## n=2, X=n--C 4 H 9 ; and R*=2-methylbutyl (the compound of Example 28) in an amount of 1% by weight. As a result, the reverse domain disappeared and a uniform nematic phase was observed.
As other agents for preventing reverse domain, a compound of the formula (I) wherein X=n--C 4 H 9 O; m=1, ##STR46## n=2; and R*=2-methylbutyl, and a compound of the formula (I) wherein X=C 2 H 5 --CH(CH 3 )CH 2 O; m=1; ##STR47## n=2; and R*=2-methylbutyl, were tested according to the same method, to obtain good results.
EXAMPLE 48 (USE EXAMPLE 8)
A mixture consisting of two compounds of the formula (I) wherein m=0; ##STR48## n=2; R*=2-methylbutyl; and X=C 6 H 13 O or C 8 H 17 O (each 30 parts) and two compounds of the formula (I) wherein m=1; ##STR49## n=2; R*=2-methylbutyl; and X=C 8 H 17 O or C 9 H 19 O (each 20 parts), exhibited SC* phase up to 75° C., exhibited Ch phase at temperatures above 75° C. and became an isotropic phase at 95° C., that is, it exhibited no SA phase.
This mixture was filled between transparent electrodes (10 μm) subjected to parallel aligning treatment by applying PVA and rubbing the surfaces, and while a direct current voltage (50 V) was impressed in the temperature range of Ch phase, it was slowly cooled so as to give SC* phase. As a result, a uniform monodomain was obtained. This liquid crystal cell was placed between two pieces of polarizers arranged in a perpendicularly crossed Nicol state, and an alternating current of 15 V and a low frequency (about 0.5 Hz) was impressed. As a result, a clear switching effect was observed, and a liquid crystal display element having a very good contrast and a high response rate (1 m sec or less) was obtained.
EXAMPLE 49 (USE EXAMPLE 9)
A liquid crystal mixture consisting of two compounds of the formula (I) wherein m=0; ##STR50## n=2; R*=2-methylbutyl; and X=n--C 6 H 13 O or n--C 8 H 17 O (each 20 parts), four compounds of the formula (I) wherein m=1; ##STR51## n=2; R*=2-methylbutyl; and X=n--C 7 H 15 O, n--C 8 H 17 O, n--C 9 H 19 O or n--C 16 H 33 O (each 10 parts) and a compound of the formula (I) wherein m=1; ##STR52## n=2; R*=2-methylbutyl; and X=n--C 8 H 17 O (10 parts), exhibited SC* phase up to 70° C., exhibited Ch phase at temperatures above 70° C. and became an isotropic liquid at 105° C., that is, it exhibited no SA phase.
To this mixture was added a dyestuff of anthraquinone group, D-16 (made by BDH Co.) in an amount of 3% by weight, to obtain a composition of the so-called guest-host type. It was then filled in the same cell as in Example 48, and one piece of a polarizer was arranged so that the polarization plane could be perpendicular to the axis of molecules. When an alternating current of 15 V and a low frequency (about 0.5 Hz) was impressed, a clear switching effect was observed, and a liquid crystal display element having a very good contrast and a high response rate (1 m sec or less) was obtained.
|
Novel ferroelectric liquid crystalline compounds having a superior stability and chiral, smectic liquid crystalline compositions containing at least one kind of the same are provided, which compounds are expressed by the general formula ##STR1## wherein ##STR2## represents 1,4-phenylene group ##STR3## or 1,4-trans-cyclohexane group ##STR4## R*, an optically active alkyl group; m=o, 1 or 2; n=1 or 2; X, a linear chain or branched alkyl group or alkoxy group, each having 1 to 18 carbon atoms; and when ##STR5## represents ##STR6## m=1; and n=1, X represents a linear chain or branched alkyl group having 1 to 18 carbon atoms or a linear chain alkoxy group having 11 to 18 carbon atoms.
| 2
|
BACKGROUND OF THE INVENTION
This invention relates to a means of construction for portable tents whereby an inner waterproof tent is contained within an outer "open-air" tent. More specifically, it relates to an outer tent comprised mainly of "mosquito net" open mesh fabric which is assembled and combined with an easily deployed inner tent of nylon, canvas, or similar material affording the user with easily erected protection in adverse weather conditions.
In the history of portable tents, as well as most other temporary shelters, provisions for "open-air" enclosures as an attachment within more protective materials is well known. In the past, when it is desired that the heavier "weather tent" material be put in place, it has been the conventional and usual practice for the tent user to exit the structure to secure the covering. Various methods for securing this outer covering have been presented with varying degrees of success.
Typically, tents have been constructed of canvas, made from cotton or other natural fiber, or nylon from a polyester or other man made fiber, which is woven tightly to provide a more or less weather impervious enclosure surface or wall. In more resent years, with greater emphasis on naturalism, fabrics for this purpose have become lighter in weight with the objective of not sacrificing the weather proof qualities of prior heavy canvas materials. When fabrics are made "weather proof" by tight weaving, the passage of air is restricted through the fabric so that tents constructed of very tight materials tend to be stuffy and warm inside because of the lack of air movement, unless they are provided with openings.
It is the usual practice to provide such openings and to cover the openings with an open mesh screen-like material, sometimes called mosquito netting. U.S. Pat. No. 1,198,773--Robinson, shows such a typical opening and also discloses the further usual practice of providing an additional piece of the weather material, sometimes called a "fly", to cover the open mesh material in the event of rain or other inclement weather. By these coverings for the openings, the necessary versatility is provided.
U.S. Pat. No. 3,621,857--R. L. May et al. and U.S. Pat. No. 1,704,945--Lefert, disclose other examples of the typical prior art technique of combining open mesh coverings for tent apertures and covering drapes or flys for weather protection and privacy.
U.S. Pat. No. 4,102,352--Kirkham, reveals a tent structure combining inner and outer fabrics with an air space between in which each of the inner and outer fabrics are relatively close knit for weather and enclosure purposes, the air space between having the purpose of providing insulation against either a cold or hot temperature differential between the outside air and that desired within the tent.
All of these prior approaches to the problems of providing versatility in the circumstance when the outer fly closer must be fastened, and the weather has turned inclement so that it is raining and storming, require that the camper exit the tent to put the protective material in place. Most all campers will recall the experience of fumbling around in the rain while snapping or tying the weather fly into place.
U.S. Pat. No. 3,621,858--Steele and U.S. Pat. No. 3,441,037--Transeau, show tent constructions in which an outer weather tent covers an inner "open-air, see-through" mesh inner tent. In the Transeau patent the outer tent is erected from the outside while in the Steele patent a draw string and eye arrangement is provided to pull the weather fly into place over the open mesh tent from a position within the open mesh tent. While this accomplishes the result of eliminating the need to exit the tent, it continues the practice of covering the mesh from the outside. It also requires a certain amount of extra set-up procedures and complications.
Other tents exist which include "open-air, see-through" mesh as the outer walls but which ignore the circumstance of inclement weather. Such tents are promoted for use in dry "desert-like" conditions.
SUMMARY OF THE INVENTION
Briefly and in summary, this invention is comprised of an outer tent of conventional design with side walls and end walls constructed of an open mesh material resistant to penetration by mosquitos and other insects or pests and having a waterproof ground covering bottom attached to the upper open mesh top. It is supported at either end by aluminum A-frames secured by guy-lines to stakes and anchored at each of four corners by ground pegs. Permanently attached to the interior of one of the side walls of the outer tent is a second inner tent which is stored in a rolled-up condition until needed. It may then be unrolled and attached at its apex to suspension hooks provided above the camper, and then secured to the side walls of the outer tent by means of zippers on three sides. A weather flap is provided to prevent water from seeping through the zippers, leaving the camper warm and dry with a minimum of inconvenience and effort.
It is a purpose of this invention to provide a convenient method of allowing the user of a portable tent to enjoy open-air camping while providing an effective waterproof covering should the need arise. It is a feature of the invention that this can be accomplished in a simple and uncomplicated procedure under any and all circumstances.
The foregoing and other advantages of the invention will become apparent from the following disclosure in which a preferred embodiment of the invention is described in detail and illustrated in the accompanying drawing. It is contemplated that variations and structural features and arrangement of parts may appear to the person skilled in the art, without departing from the scope or sacrificing any of the advantages of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an outer tent of this invention in erected condition with a weather tent rolled up along one side.
FIG. 2 is a perspective view of the outer tent with the weather tent erected to the apex for use as a sun shade on one side.
FIG. 3 is a perspective view of the outer tent with the weather tent erected within and in its completely weather proof condition.
FIG. 4 is an enlarged cross section through the bottom to wall connection of the outer and inner tents.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, an outer tent 10 of this invention is shown erected with an A-frame support means 11, preferably constructed of light weight metal such as aluminum, in place at both ends. Guy-lines 12 are attached at the pinnacle of the support means 11 and stretched taut to a ground peg 13. The outer tent is constructed of open mesh screen-like material at both side walls 22 and end walls 23. The outer "mosquito net" tent 10 is attached to and suspended by support cords 16 to a pinnacle of the support means 11, thereby maintaining the outer tent 10 in an erected position.
A waterproof bottom 17 rests upon a substrate such as the ground. The bottom 17 with upstanding border elements 18 is fastened to the side walls 22 and end walls 23 of the outer tent 10 at a first lower edge by sewing along a connection line 19 a portion of the distance up the border elements 18. Each of the four corners of the bottom 17 are secured by ground pegs 20 and held in a taut condition. The bottom 17 may be omitted with the border elements 18 pegged directly to the ground.
An end opening zipper 21 is shown at one end wall 23 of the outer tent 10 to provide an entrance. Of course, the other end may have a similar entrance/exit also. Thus, the structure created is of a well-known triangular four-sided apex A-frame configuration.
Connected to a border element 18 on a side wall 22 is a weather tent fly 25, preferrably rolled up and resting on the bottom 17. In its undeployed position shown, the weather tent fly 25 is rolled but it could be folded accordion style or in another position occupying a minimum space.
When the outer tent 10 is erected as shown in FIG. 1, the structure is relatively open because of the mesh fabric from which the tent walls 22 and 23 are constructed. Air-breezes may pass readily through, and occupants within the tent or observers outside the tent may see what is happening on the other side in the opposite position. When the weather is good and comfortable, occupants may enjoy the "outdoors" to a large degree, almost approximating the experience of sleeping out under the stars and the pleasures thereof.
Referring to FIGS. 2 and 4 also, an upper edge of the border element 18 is provided with fastening means, preferrably a zipper edge 28, which is attached continuously around three sides not occupied by the weather tent fly 25. A matching zipper edge 29 extends entirely around the edge of the weather tent fly 25, for connection to the zipper edge 28, as will be later explained. When the occasion arises, at the desire of the occupant of the outer tent 10, the weather tent fly 25 is unfurled or deployed upward along one side 22 of the outer tent 10 to the apex where it attaches to an anchor 26 with fastening means, such as through an eyelet on the edge, or by an elastic cord, for example.
In this erection position, the erected portion of the fly 25 acts as a sun and wind shield, having many of the aspects of a "lean-to", which will be familiar to most campers. In this position fly 25 will ward off the direct rays of the sun providing shade within the enclosure without obstructing breezes.
Wnen the tent 10 is deployed in the arrangement of FIG. 2, additional material 41 not required for the "lean to" side, is tied back parallel to that side. Folded end flaps 42 may be tucked in between the sides 25 and 41.
Referring to FIG. 3, in the event of inclement weather or even to prevent the moisture of a morning dew from settling on the occupants of the tent 10, the remainder of the weather fly 25 is unfurled or deployed on the other side and the zipper edge 28 is connected to the zipper edge 29 by zipping at a second lower edge all around the border element 18. Because the fly 25 makes connection to the border element 18 within the outer tent wall, as mostly clearly seen in FIG. 4, connection can be made completely from within the inner and outer tents and without exiting. In a small one or two person triangular tent, such as that shown in FIGS 1-4, this may be accomplished simply by sitting up and without climbing out of the sleeping bag or other sleeping material. As shown in FIG. 4, an overlapping edge 31 extends over the enclosed zipper edges 28, 29 making the enclosure weather tight from the outside and accessible from the inside.
Referring again to FIG. 3, an end closure 33 or 42 may be provided in one or both end walls 23 leaving access to the interior as necessary and desirable.
Additional guy lines 40 may be added at various places on the tent walls to pull the sides out with more tension and provide more room inside. The weather tent 25 may be tied to the outer tent 10 at additional places to create greater tension and pull the sides out.
The tent construction means is shown as it relates to a well known triangular four sided apex A-frame type of tent, but of course there are many other shapes of tents including those shown in the references cited above. The tent construction of this invention is equally applicable to other shapes and should not be considered referring only to the preferred embodiment as revealed in this disclosure. Pyramid, umbrella, cabana, etc. type shapes could equally be constructed having an outer open mesh tent and an inner weather fly/tent where the advantages of the invention can be used.
Without departing from the spirit of this invention, various means of fastening the material together may be used, including the zippers shown, eyelets, snaps and snap buttons, and sewing or plastic heat sealing may be employed.
It is therefore understood that although the present invention has been specifically disclosed with the preferred embodiment and examples, modifications to the design concerning sizing and shape may be apparent to those skilled in the art, and such modifications and variations are considered to be within the scope of the invention and the appended claims.
|
A portable tent construction in which an outer tent of see-through "mosquito net-like" material completely encloses an inner waterproof weather tent which can be erected by the occupant from within the outer tent without the inconvenient necessity of exiting the tent. Implementation is uncomplicated and may be partially or totally completed as desired.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of International Application No. PCT/EP2006/067568 filed Oct. 19, 2006, which designates the United States of America, and claims priority to German application number 10 2005 054 880.6 filed Nov. 17, 2005, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The invention relates to a method for verifying the tightness of a tank venting system of a motor vehicle.
BACKGROUND
In such systems, the tank venting system has a tank venting valve in a regeneration line which connects a storage container collecting fuel vapors from a fuel tank with an intake pipe of an internal combustion engine, a stop valve for sealing the tank venting system such that it is air-tight relative to an atmosphere prevailing outside the motor vehicle, and a bistable pressure switch, the switched state of which indicates whether a predefined switching pressure is exceeded or not reached in the tank venting system.
In the usual methods used to verify the tightness of a tank venting system while a motor vehicle is in motion, as described in DE-19713085-A1 for example, the tank venting valve is opened so that the negative pressure in the intake pipe can disperse in the tank venting system. Once the tank venting valve has been subsequently closed, the pressure should remain approximately at the level of the negative pressure reached. Both the extent of the negative pressure reached as well as the period until this negative pressure is reached and the behavior of the pressure after the tank venting valve is closed enable conclusions to be drawn regarding a possible leak in the tank venting system. A pressure sensor is required in order to be able to continually observe and monitor the pressure curve.
By way of contrast, various methods for verifying a possible leak in a tank venting system which can be performed when the engine is switched off are known from DE 102 45 158 A1. In one of these methods, the drop in the engine coolant temperature after the warm engine is switched off is observed. If there is a sufficiently small temperature, it is assumed that the fuel tank has also cooled and that the pressure prevailing in the tank venting system has also dropped. At the same time, a vacuum switch is monitored which is triggered at a certain negative pressure. If the vacuum switch has not been triggered even though the temperature has already dropped sufficiently, it is suggested that there is a leak in the tank venting system.
The advantage in this method lies in that a pressure sensor is no longer required. The considerably more reasonably priced vacuum switch or pressure switch reduces the cost of the method. However, the comparatively long waiting time of up to several hours until the temperature has dropped sufficiently to be able to come to a reliable conclusion about the existence of a leak is disadvantageous.
SUMMARY
According to an embodiment, a method of the type mentioned above can be specified with which the time required for verifying the tightness of the tank venting system is reduced and without the use of a pressure sensor. According to various embodiments, a method for verifying the tightness of a tank venting system of a motor vehicle comprising a tank venting valve in a regeneration line, which connects a storage container collecting fuel vapor from a fuel tank to an intake pipe of an internal combustion engine, a stop valve for sealing the tank venting system so that it is air-tight against an atmosphere prevailing outside the vehicle and a bistable pressure switch, the switching states of which indicate that the pressure in the tank venting system is above or below a predetermined switching pressure, the method comprising the steps:—Waiting for the vehicle speed to drop below a threshold,—Opening the tank venting valve,—Closing the tank venting valve when a negative pressure has been attained that is below the switching pressure,—Measuring the period from an initial pressure that is below the switching pressure until the next time the pressure exceeds the switching pressure,—Assessing the tightness using the measured duration.
According to a further embodiment, once the tank venting valve is opened, a constant volumetric flow through the tank venting valve may be regulated by means of varying the degree of opening of said valve and that the stop valve is opened at the same time as the tank venting valve and the degree of opening of the stop valve is varied such that the pressure alternately drops below, exceeds and then again drops below the switching pressure at least once in succession, whereupon the stop valve is closed, while the tank venting valve remains open for a defined period. According to a further embodiment, the duration between the closing of the stop valve and the next time the pressure exceeds the switching pressure may be determined as the sum of defined duration and the duration until the switching pressure is exceeded. According to a further embodiment, the stop valve may be closed when the vehicle speed has reached zero. According to a further embodiment, during the varying of the degree of opening of the stop valve, a value for escaping fuel vapor may be determined from the regulated cycle of changes of pressure above and below the switching pressure and from a value for the charge state of the storage container with fuel vapor. According to a further embodiment, a membrane may be provided which is able to form a connection between the tank venting system and the atmosphere prevailing outside the vehicle, whereby the membrane opens slightly at a specified negative pressure that is less than the switching pressure, and that the tank venting valve is held open after the pressure has dropped below the switching pressure for the first time until the specified negative has been reliably achieved. According to a further embodiment, the stop valve may be actuated with a pulse at the same time the tank venting valve closes and that the membrane is thus abruptly closed. According to a further embodiment, the stop valve may be actuated before the pulse in such a way that there is a constant and very small degree of opening. According to a further embodiment, the tank venting valve may not be closed until the vehicle speed has reached zero. According to a further embodiment, during the measuring of the duration until the switching pressure is exceeded, the vehicle may be monitored to determine whether it still has a vehicle speed of zero.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in more detail below with reference to exemplary embodiments and drawings, in which;
FIG. 1 shows an internal combustion engine with fuel tank and tank venting system;
FIG. 2 shows chronological sequences during a first embodiment of the tightness verification;
FIG. 3 shows a comparison of the pressure reduction and pressure build-up times with and without a leak;
FIG. 4 shows chronological sequences during a second embodiment of the tightness verification.
DETAILED DESCRIPTION
According to various embodiments, the method may start with checking whether the vehicle has dropped below a threshold for vehicle speed. This threshold is selected so as to be low enough that strong vibrations of the vehicle need no longer be expected, i.e. the threshold is in a range close to the vehicle being stationary, preferably 10 km/h or less. Once the speed has dropped below the threshold, the tank venting valve is opened so that the pressure in the tank venting system drops due to the negative pressure in the intake pipe. The tank venting valve is kept open until a negative pressure has been attained that lies below the switching pressure. Because the switching pressure is selected so that it lies below the pressure that prevails in the tank venting system under normal operating conditions, this means that, while the tank venting valve is open, the pressure drops below the switching pressure at least once, so that the pressure switch is triggered accordingly. Once the tank venting valve has closed, the duration until the switching pressure is exceeded again is measured, starting from an initial pressure that is less than the switching pressure. The tightness of the tank venting system is then assessed using the measured duration. Essential to the method according to various embodiments is the determination of a defined negative pressure that lies below the switching pressure and that can also be designated as the initial pressure. Starting from this initial pressure, the duration is then determined until the next time the pressure switch is triggered due to the switching pressure being exceeded. Using the values of the initial pressure, switching pressure and duration, a pressure build-up rate can be calculated, the value of which is used as an indicator of whether there is a leak or not. However, it is also sufficient to assess only the value of the measured duration, because the pressure difference always remains constant. Essentially, the quicker the pressure build-up, the more likely a leak is present or the greater any leak.
The advantage of the method is that, on the one hand, there may be no need for a pressure sensor, because, as the initial pressure is known, it is only necessary to determine a second pressure, which is possible using a simple pressure switch. On the other hand, it may no longer be necessary to wait several hours until a negative pressure is attained in the tank venting system due to natural reduction in temperature; instead the negative pressure is generated systematically and within a few seconds by opening the tank venting valve.
The initial pressure is generated in two different ways according to various embodiments.
In one embodiment, a constant volumetric flow is regulated through the tank venting valve after the tank venting valve is opened by varying the degree to which the latter is opened. This is achieved by the actuation of the tank venting valve by means of an appropriate PWM signal according to the known methods (e.g. DE 10 2005 003 924). The stop valve is opened at the same time as the tank venting valve and the degree to which the stop valve is opened is varied such that the pressure alternately and successively drops below, exceeds and then again drops below the switching pressure. This process is also known as toggling around the switching pressure, whereby the stop valve is preferably again actuated by means of a PWM signal. The stop valve is then closed, while the tank venting valve remains open for a fixed duration.
While the tank venting valve and stop valve are open at the same time and before the toggling begins, the pressure in the tank venting system drops, despite the air flowing in from the outside atmosphere, because the volumetric flow through the tank venting valve is greater than that through the stop valve. Accordingly, the pressure drops below the switching pressure for the first time. Once the switching pressure has been dropped below for the first time, the toggling around the switching pressure begins, i.e. the opening in the stop valve is first enlarged until the switching pressure is exceeded again, and then reduced until pressure next drops below the switching pressure again. The pressure in the tank venting system is thus regulated to the switching pressure, whereby the alternate enlarging and reducing of the opening of the stop valve can be repeated as often as required. Starting from the switching pressure as a fixed initial value, a drop in pressure is then generated for a defined duration with the stop valve closed. This drop in pressure occurs in every case so that, at the end of the defined duration, the initial pressure is present from which the subsequent duration until the next time the switching pressure is exceeded is measured. The shorter the duration until the switching pressure is exceeded, the greater the size of any leak. Alternatively, the total of the defined duration and measured duration can be calculated and assessed. The variation according to the size of a leak is even clearer here, because any leak prevents a particularly low pressure from being reached during the pressure reduction within the defined duration, which already shortens the subsequent duration of the pressure build-up until the switching pressure is exceeded. Furthermore, the pressure build-up is accelerated by the leak, such that the total duration is much shorter than with an intact tank venting system. The calculation of the total of the durations thus utilizes a dual effect of the reduced time as a consequence of a leak.
In order to increase the precision of the method, in an embodiment, the stop valve is not closed until the vehicle speed has reached zero, because various operational influences can distort the pressure curve in the tank venting system when the vehicle is in motion.
According to a further embodiment, a value is determined for the fuel vapor flowing out of the storage container while the degree that the stop valve is open is being varied. This value is determined using the set cycle of alternation between the pressure exceeding and falling below the switching pressure and using the charge level of the storage container with fuel vapor. If the calculated value for fuel vapor flowing out is within an expected range, which primarily depends on the charge level, it is concluded that there is at least a small leak. Because this method only permits a rough estimate, it is used to identify whether there is a large leak of greater than 1 mm in diameter. This conclusion is then checked and substantiated by means of the following duration measurement.
The generation of the initial pressure that is below the switching pressure by toggling around the switching point with an initial opening of the tank venting valve for a fixed duration is particularly suitable for stop valves in which the degree to which it is opened can be fractionally varied. For stop valves with which the precision adjustment of a desired opening of this type is not directly possible, a second method for generating the initial pressure is suggested.
According to an alternative embodiment, a membrane is provided to create a connection between the tank venting system and the atmosphere prevailing outside the motor vehicle. The membrane either forms a connection with the atmosphere in addition to the stop valve or, in an appropriately designed embodiment, it can take on the full functionality of the stop valve. The membrane opens to a minimal degree at a specified negative pressure, which is less than the switching pressure. Once the pressure falls below the switching pressure for the first time, the tank venting valve is then held open until the specified negative pressure is reliably achieved.
In terms of its shape and the selected material, the membrane is designed in such a way that it deforms at the specified negative pressure, so that air from the outside atmosphere can flow into the tank venting system. This prevents the falling pressure caused by the opening of the tank venting valve from falling to a level that would result in the damage or destruction of the tank and/or the tank venting system. The specified negative pressure is thus greater than the pressure level that would cause damage.
The longer opening of the tank venting valve for a duration of a few seconds ensures that the specified negative pressure is reliably achieved. This is then designated as the initial pressure, i.e. once the specified negative pressure has been reliably achieved, the tank venting valve is closed and the duration until the next time the switching pressure is exceeded is determined in order to assess the tightness.
In an embodiment with a stop valve and additional membrane, the stop valve is actuated with a pulse at the same time that the tank venting valve is closed and the membrane is thus abruptly closed. This prevents the conclusion about tightness from being distorted by the membrane deformation which would otherwise still be present. If the membrane is not closed at the same time as the tank venting valve, the proportion of the air flowing in via the membrane would have to be deducted from the duration of the pressure build-up from the initial pressure to the switching pressure.
In a development of the embodiment, the stop valve is actuated before the pulse in such a way that a constant and very small opening is present. In this way, the specified negative pressure at which the membrane deforms can be influenced and set to a desired value.
Also in the alternative embodiment in which the initial pressure is generated by means of the deformable membrane, the precision of the tightness verification can be increased whereby the tightness verification is performed when the vehicle is stationary. In a development, the tank venting valve is therefore not closed until the vehicle speed has reached zero.
According to a development in all embodiments mentioned, the vehicle is monitored during the measuring of the duration until the switching pressure is exceeded to determine whether it is still exhibiting a vehicle speed of zero. As soon as the vehicle starts to move again, i.e. as soon as a low speed threshold is exceeded, the method is cancelled in order to prevent incorrect conclusions.
The internal combustion engine 1 of a motor vehicle shown in FIG. 1 has an intake pipe 2 in which a throttle valve 3 is located. The intake pipe 2 is connected to a storage container 5 of a tank venting system by means of a regeneration line 4 , and the storage container 5 is in turn connected to a fuel tank 7 by means of a venting line 6 . The fuel vapor 9 that collects above the liquid fuel 8 in the fuel tank 7 is routed via the venting line 6 into the storage container 5 , where it is trapped in an activated carbon filter. The fuel tank 7 is closed by means of a tank cap 10 . The storage container 5 is connected to the external atmosphere 11 by means of a ventilation line 12 . This connection can be interrupted by means of a stop valve 13 , whereby a bistable pressure switch 54 is arranged in the stop valve which emits a switching signal 55 which alternates between low and high. A tank venting valve 14 is arranged in the regeneration line 4 . Several sensor measurements from the internal combustion engine are fed to an engine control unit 15 , containing a computing unit among other things, for example the air fuel ratio 17 of the exhaust emitted from the internal combustion engine 1 via an exhaust system 18 that is determined by means of a λ sensor 16 , as well as the gas mass flow rate 19 of the air sucked into the internal combustion engine 1 by means of the intake pipe 2 . The computing unit of the engine control unit 15 uses these and other measurements, such as the speed and torque of the internal combustion engine 1 to determine various actuating variables for influencing the operation of the internal combustion engine 1 , for example the injection time 21 which is to be set in an injection system 20 for introducing fuel. Furthermore, the computing unit of the engine control unit 15 calculates the degree of opening 22 of the tank venting valve 14 and the degree of opening 23 of the stop valve 13 and controls both valves 13 and 14 by means of appropriate PWM signals.
FIG. 2 shows the temporal course of a tightness verification, in which the toggling around the switching pressure takes place. The various curves show in detail: the path of the vehicle speed 24 (v), the path of the volumetric flow 25 through the tank venting valve 14 (CPS_F), the path of the pressure 26 inside the tank venting system (DTP), the switching status 27 of the pressure switch (S), and the degree of opening 28 of the stop valve 13 .
The path of the pressure 26 is only given here for illustration purposes. It is not measured during normal operation, because there is no pressure sensor in the tank venting system. A total of four periods are indicated with Roman numerals. Period I represents an initial phase; the switching pressure 33 is set in period II; the initial pressure below the switching pressure is reached in period III; and the pressure build-up for the tightness verification takes place in period IV. The processes are described in more detail below.
In time period I, the vehicle speed 24 slowly drops, because the vehicle is rolling up to a junction for example. As soon as the speed drops below the speed threshold 29 of 6 km/h for example at point in time 30 , the tank venting valve 14 is opened in a controlled manner by means of a PWM signal so that the volumetric flow 25 increases linearly until it is maintained at a desired constant value 31 . At the same time, the stop valve 13 is opened in a controlled manner, as can be seen from its degree of opening 28 . The reduction in the pressure 26 regulated by the opening of the tank venting valve 14 causes the pressure 26 to drop below the switching pressure 33 for the first time at point in time 32 . A maximum of 2 seconds pass between point in time 30 and point in time 32 . Now the toggling around the switching pressure 33 begins, i.e. the PWM signal for actuating the stop valve 13 is varied in such a way that the pressure alternately exceeds and drops below the switching pressure 33 several times, as can be seen from the switching status 27 of the pressure switch. At point in time 34 , the vehicle reaches a standstill, i.e. the speed is zero and the engine is idling. Because, at this point in time 34 , the switching pressure 33 in the tank ventilation system has already been regulated, i.e. because the switching pressure 33 has alternately dropped below, exceeded and then again dropped below the switching pressure 33 at least once in succession, the stop valve 13 is closed. The tank venting valve 14 remains open for a previously determined duration in period III, which causes the pressure 26 in the tank venting system to drop below the switching pressure 33 until it reaches an initial pressure 56 . At point in time 35 , the tank venting valve 14 is also closed. Due to the natural emission of fuel vapor 9 , the pressure 26 now begins to climb again. The duration between point in time 35 and the next time the pressure switch is triggered at point in time 36 is measured and added to the defined duration of period III. In this example, there is no leak present, i.e. the total duration is sufficiently long.
In FIG. 3 , the path of the pressure 26 in periods III and IV is compared to a pressure 37 where a leak is present. As a consequence of the leak, the pressure 37 drops more slowly during the opening phase of the tank venting valve 14 in period III, because air from the atmosphere 11 is able to enter the tank venting system. Once the tank venting valve 14 has closed, the pressure 37 also climbs more quickly, because not only fuel vapor 9 from the tank 7 is flowing in, but also air from the outside. Due to this dual effect, there is a clear difference 38 between when pressure 37 and pressure 26 exceed the switching pressure 33 , i.e. a clear conclusion can be made about the presence of a leak.
FIG. 4 shows the temporal course of a tightness verification with a stop valve 13 that has a membrane that opens slightly at a specified negative pressure 48 that lies below the switching pressure 33 . It shows the paths of the vehicle speed 39 (v), the volumetric flow 40 through the tank venting valve 14 (CPS_F), the pressure 41 inside the tank venting system (DTP), the switching status 42 of the pressure switch (S), and the degree of opening 43 of the stop valve 13 generated by means of a PWM signal. In a slight modification to FIG. 2 , the three periods indicated with Roman numerals represent the following: period I is again the initial phase; the initial pressure below the switching pressure 22 is achieved in period II; and the pressure build-up for the tightness verification takes place in period III.
Once the vehicle speed 39 has dropped below a threshold value 45 of 10 km/h for example at point in time 44 , the tank venting valve 14 is opened. The stop valve 13 remains closed, as can be seen from its degree of opening 43 . As a consequence of the opening of the tank venting valve 14 , the pressure 41 in the tank venting system drops, so that, at point in time 46 , it drops below the switching pressure 33 . The pressure 41 continues to drop until it reaches the specified negative pressure 48 at point in time 47 at which the membrane of the stop valve 13 opens a little on its own. Because this process is not controlled, no change can be seen in the path of the controlled degree of opening 43 . However, the slight opening of the membrane stops any further pressure reduction, which creates a virtual equilibrium around the specified negative pressure 48 , wherein the value of the negative pressure 48 that is currently present depends on the fuel fill level and the current temperature. At point in time 49 , the vehicle speed 39 reaches zero. However, the tank venting valve 14 is not closed until after a predetermined duration of period II expires at point in time 50 . The duration of period II is determined beforehand using measurements or model calculation and in such a way that the specified negative pressure 48 is reliably reached following the expiry of the period. This should be the case after a few seconds. So that the observed increase in pressure 41 after point in time 50 is not distorted, a pulse 51 is emitted to the stop valve 13 at the exact time that the tank venting valve 14 closes, so that the membrane of the stop valve is abruptly pushed closed. The duration between point in time 50 and the next time the pressure exceeds the switching pressure 33 at point in time 52 can be used again as an indicator for any leak present in the tank venting system, i.e. the shorter the period, the more likely it is that a leak is present.
In order to move the level of the specified negative pressure 48 , in an alternative embodiment, the stop valve is very slightly opened in a controlled manner during periods I and II, that is until the tank venting valve 14 is closed at point in time 50 , as is shown with path 53 .
|
In a method for verifying the tightness of a tank bleeding system with a tank bleeding valve, a stop valve for air-tightly closing the tank bleeding system relative to an atmosphere prevailing outside the motor vehicle, and a bistable pressure switch whose switched condition indicates whether a predefined switching pressure is exceeded or not reached in the tank bleeding system, in order to be able to determine the tightness of the tank bleeding system without using a pressure sensor, the following steps are carried out: waiting until the vehicle speed drops below a certain threshold; opening the tank bleeding valve; closing the tank bleeding valve when a negative pressure has been attained which lies below the switching pressure; measuring the duration from the time an initial pressure lies below the switching pressure until the moment the switching pressure is exceeded again; and assessing the tightness is assessed based on the measured duration.
| 5
|
This application claims benefit of Provisional Application No. 60/061,339, filed Oct. 8, 1997.
BACKGROUND OF THE INVENTION
This invention relates to metal oxide and/or organofunctionalized metal oxide coated metal oxide particles, where the two metals are not the same. Such materials are obtained by reaction of the pre-formed particles with a monomeric precursor to the coating, and characterized by extremely high levels of uniformity in coating thickness over both the surface of individual particles and the particle population.
In many applications using titania particles as a white pigment, the lifetime of the pigmented material, paints or plastics for example, is reduced by chemical processes initiated by photo-excitation of the pigment particles. As a result, technologies to improve the durability of pigmented objects have been developed which suppress the photocatalytic activity of titania pigments. The most successful approach to this problem has been coating the particles with silica or silica/alumina layers. Pigments with silica coatings at 1.5-2.0 weight % are characterized as "durable" pigments, and at 5-6 weight % are described as "high durability" pigments.
These efforts to reduce photocatalytic activity of titania pigments are not without disadvantages. First, pigment gloss degrades rapidly with added silica. High gloss and durability are therefore difficult to attain simultaneously in products based on this approach. Second, titania particles with pure silica surfaces do not disperse well in many of the vehicles in which pigments are used. This requires additional surface treatments, typically involving deposition of partially crystalline alumina layers. Therefore, other methods for suppressing the inherent photoactivity of pigment particles are of interest, either to minimize the severity of the tradeoffs in the properties of the finished pigment, or to confer cost or flexibility advantages in new manufacturing production facilities.
SUMMARY OF THE INVENTION
The present invention discloses a process for preparing metal oxide particles having a substantially uniform coating, the process comprising the steps of reacting a plurality of metal oxide particles with at least one precursor selected from the group consisting of monomeric metal oxide precursors and organofunctionalized metal oxide precursors, wherein the monomeric metal oxide precursors are selected from the group consisting of tetraalkoxysilane; SiCl 4 ; Al(i-propoxide) 2 (acetoacetate); and Zr(alkoxide) 4 ; and wherein the organofunctionalized metal oxide precursors are selected from the group consisting of n-alkylalkoxysilane, wherein the n-alkyl is C 1 -C 16 and the alkoxy is C 1 -C 6 ; n-alkyltrichlorosilane wherein the n-alkyl is C 1 -C 16 ; and n-alkyltrialkoxysilane wherein the n-alkyl is C 1 -C 16 and the alkoxy is C 1 -C 6 ; with the proviso that the metal oxide of the coating is different from the metal oxide of the particles.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1a is a histogram of the coating thickness distribution obtained from analysis of transmission electron microscopy images of a representative sample of the uniformly coated (at 0.68 wt % SiO 2 ) metal oxide particles of this invention using tetraethylorthosilicate as an SiO 2 precursor.
FIG. 1b is a histogram of the coating thickness distribution obtained from analysis of transmission electron microscopy images of a representative sample of coated (at 0.52 wt % SiO 2 ) metal oxide particles produced using a sodium silicate solution as the SiO 2 precursor in accordance with U.S. Pat. No. 2,885,366.
FIG. 2 is a transmission electron micrograph (TEM) image of a TiO 2 sample of this invention having a silica coating of approximately 2% by weight, particularly illustrating the substantially uniform coating of a particle and among particles.
DETAILED DESCRIPTION OF THE EMBODIMENTS
As part of our investigation of the photocatalytic chemistry of TiO 2 pigment particles we have prepared and characterized samples of coated particles that are extremely uniform in microstructure. In contrast to the traditional routes for coating pigments which use colloidal precursors to metal oxides, these coatings are applied using monomeric precursors to a metal oxide, for example, tetraethylorthosilicate (TEOS), as a silica (SiO 2 ) precursor. At the same weight % silica, these particle coatings are distributed much more uniformly than in the conventional coated pigments. For example, using transmission electron microscopy we can demonstrate that with 0.5-0.7 weight % silica deposited onto the particle population, over 90% of the particles have a coherent surface coating. Furthermore, the coating can be described with a thickness probability distribution that closely approximates a delta function with a significant population only at the thickness that would be expected if the measured weight percentage of silica were uniformly distributed over the entire sample's surface area. This stands in marked contrast to the best laboratory-produced coatings from polymeric silicate precursors, where more than 50% of the particles are partially uncoated at this weight % silica, and for which the thickness probability distribution approximates a Gaussian function with a mean near the expected thickness for uniformly applied amorphous silica, and a standard deviation roughly equal to half the mean. The high degree of coating uniformity in these materials has value in pigmentary applications. It leads to an improvement in the efficiency of silica utilization for photoactivity suppression. It is expected to enable the preparation of pigments that combine high gloss and high durability. It results in pigments that show more uniform behavior in subsequent processing steps.
In the second aspect of the invention, metal oxide particles are coated via reaction of monomeric oxide precursors with the surface of preformed metal oxide particles, especially silica deposited onto titania. Simply speaking the process comprises the step reacting a monomeric precursor with the particle in the presence of water in an amount sufficient to hydrolyze the precursor. First a metal oxide particle sample is wetted by adding water in an amount sufficient to stoichiometrically hydrolyze the oxide coating precursor. Some of this water may also be present simply by the natural adsorption of water vapor from humid air in which case it may be defined by a TGA analysis. The dampened metal oxide particles are then exposed to one or more monomeric metal oxide and/or functionalized metal oxide precursors. Such precursor is typically slurried into an inert organic solvent carrier such as toluene, hexane etc. in which it is completely soluble/miscible. The slurry of the damp titania in the precursor solution is then allowed to react, under moderate heating (reflux of solvent vehicle) and with excellent mixing for ˜4 hours so as to allow adequate time for the hydrolysis reaction between the precursor molecules, the particle surface and the adsorbed water to reach completion. The sample is then filtered, washed and dried over flowing air to recover the coated metal oxide particles.
Examples of monomeric metal oxide precursors that may be used to advantage include TEOS, tetramethylorthosilicate (TMOS), SiCl 4 , Al(i-propoxide) 2 (acetoacetate), Zr(alkoxide) 4 , etc. Examples of organofunctionalized metal oxide precursors include n-alkyltrialkoxysilanes where the n-alkyl is C 1 -C 16 and the alkoxy is C 1 -C 6 ; (e.g., methyltriethoxysilane, ethyltriethoxysilane octyltriethoxysilane, etc.); and C 1 -C 16 alkyltrichlorosilanes.
Examination of the photoactivity, particle morphology and chemical analysis of the resulting particles indicate a high level of control over the resulting coating morphology in terms of uniform thickness and excellent particle to particle homogeneity. The control of water content and monomeric reagent quantity added to the original particle dictates the final coating thickness, etc.
EXAMPLE
2 g of pyrogenic TiO 2 was placed in a small round-bottom flask and 8 microliters of water was added by syringe. The damp TiO 2 was then tumbled thoroughly for 30 minutes at room temperature and atmospheric pressure so as to uniformly disperse the water over the TiO 2 surface. The flask was taken into an inert atmosphere glove box and 2 mL toluene containing 0.07 g tetraethylorthosilicate (TEOS) was added. The flask was attached to a rotary evaporator and the system was freeze-pump-thawed to evacuate. The flask, with slurry, was then tumbled under static vacuum at 100° C. (oil bath heater) for 4 hours. At the end of the time, 25 mL ethanol was added and the resulting slurry was filtered, washed with another 100 mL ethanol, then 25 mL water and finally 25 mL acetone. The solid was then suction dried before drying in flowing air at 80° C. for 1 hour.
The recovered dry solid was analyzed for silicon by x-ray fluorescence. The sample contained 0.58 weight percent Si as SiO 2 . A histogram of the coating thickness distribution obtained from analysis of transmission electron microscopy images of a representative sample prepared by this method is shown in FIG. 1a. A comparison of FIG. 1a with FIG. 1b shows that the compositions of the present invention have substantially more uniform coatings on the surfaces of the individual particles and among particles in the composition.
Photo-oxidation of 2-propanol.
10 mg of TiO 2 powder is placed in a test tube containing a magnetic stir bar. 2 mL of an 0.40M solution of 2-propanol in pentane [containing 0.01M cis/trans decalin as an internal standard] is added. The test tube is sealed by attaching a stopcock and a vacuum adapter using a Viton® "o ring" and a pinch clamp. The solution is irradiated with continuous stirring for 2 hours at a fixed distance from a medium pressure Hg lamp contained inside a Pyrex immersion well. Standard samples are irradiated simultaneously and identically to assure run-to-run reproducibility. Conversion of 2-propanol to acetone is determined by gas chromatography. See generally, P. R. Harvey, R. Rudham and S. Ward; J. Chem. Soc., Faraday Trans, 1, 1983, 79, pp. 1381-1390.
Results are reported in Table 1. For comparison purposes, the photoactivity of uncoated TiO 2 pigment, R902 grade "durable" pigment (available from DuPont), and TiO 2 pigment coated at the same weight percent silica by the sodium silicate solution method are also reported.
TABLE 1______________________________________Sample Identification Photoactivity______________________________________Uncoated TiO2 14.3 Coated TiO.sub.2 (Sodium Silicate Method) 7-10 DuPont R902 durable pigment 1.0 Coated TiO.sub.2 (Inventive Method) 1.7______________________________________
The difference in photoactivity at the same weight percent silica can be ascribed to the more uniform surface coverage obtained from the present invention. The particles of the present invention are comparable to commercial "durable" pigments in photoactivity, but comprise a lower weight percent silica and thus have higher gloss. In addition, at lower weight percent silica, the raw material costs to produce these pigments is lower as compared to commercially available durable pigments.
|
Metal oxide particles having a substantial uniform and homogeneous (across-particle) coating of a metal oxide or organofunctionalized metal oxide are disclosed and are prepared by hydrolysis of a monomeric precursor to the coating.
| 2
|
FIELD OF THE INVENTION
The present invention relates to a control circuit for an inductive load driver suitable for use in electronic ignition applications and smart power devices.
BACKGROUND OF THE INVENTION
As it is well known in the art, in smart power devices a linear control circuit is generally capable of driving a power element and allowing the highest voltage and deliverable current to be provided and diagnostic functions to be performed. These smart power devices are powered in two different modes. In a first mode, the control circuit receives a trigger signal and is powered by a battery. In a second mode, the control signal receives a trigger signal, and is also powered by the trigger signal, and is not coupled to the battery.
In particular, FIG. 1( a ) shows a known solution. A control block 1 drives a first power element, in particular an IGBT transistor TR 1 of electronic device 2 . Control block 1 is powered by a supply voltage Vbat and activated by a trigger signal V TRIGGER .
The first power element TR 1 is inserted between a first voltage reference, in particular a supply voltage Vbat and a second voltage reference, for example a ground reference GND. The first power element TR 1 has a first conduction terminal, in particular a collector terminal C, coupled to the first voltage reference Vbat, a second conduction terminal, in particular an emitter terminal E, coupled to GND, as well as a control terminal, in particular a gate terminal G coupled to control block 1 . The first power element TR 1 is also coupled to an inductive load, for example a primary winding 3 A of a coil, coupled in turn to the supply voltage reference Vbat and to an igniter plug 3 B of the coil itself.
A second power element, in particular an IGBT sensing transistor TR 1 SENSE , and a sensing resistance Rs are coupled in series to each other and in parallel between the terminals C and E of the first power element TR 1 .
During conduction, the two power elements TR 1 and TR 1 SENSE sink different fractions of the same conduction current I COIL .
FIG. 1( b ) shows a second known solution. FIG. 1( b ) shows a control block 10 , which is changed with respect to the control block 1 shown in FIG. 1( a ). The supply voltage of block 10 is provided by the voltage at the high state of the trigger signal, as well as being used to activate the control block 10 .
For the smart power devices such as those shown in FIGS. 1( a ) and 1 ( b ), the lowest and the highest output current I COIL and the lowest and the highest voltage of control signal V TRIGGER are specified. It is necessary that the smart power device 2 shown in FIGS. 1( a ) and 1 ( b ) correctly operates even in the worst case operating situations. A worst case operating situation occurs for low battery voltages Vbat at extreme temperatures, when the trigger voltage V TRIGGER , at the high state, can be reduced. For example, the signal ground can be separated from the power ground, and the real voltage being applied between the gate G and emitter E terminals of the first power element TR 1 is further reduced by the voltage drop ΔV introduced by connection cables and connectors.
FIG. 2 shows the same control block 10 of FIG. 1( b ), wherein the voltage drop ΔV introduced by cables and connectors is shown.
For electronic ignition applications, in the automotive field, under “normal” operating conditions, it is traditionally required that a power element, in the case of FIG. 2 the first power element TR 1 , is capable of delivering an output current I COIL no lower than 17 amperes, with a trigger signal V TRIGGER at the input of the block whose level is equal to 5 volts. Under worst case operating conditions, however, the voltage value of the trigger signal V TRIGGER can be reduced down to 2.5 volts.
In the non-limiting case wherein the power element TR 1 is an IGBT transistor, the highest voltage applied on the gate terminal G is given by the trigger voltage V TRIGGER minus the voltage drop ΔV introduced by the control block 10 . This voltage also determines the highest output current I COIL deliverable by smart power device 2 .
In this situation, it is very difficult to meet the required specification concerning the minimum output current I COIL of 17 amperes, with the reduced-voltage trigger signal V TRIGGER , unless an IGBT transistor with an oversized area is used.
FIGS. 3( a ) and 3 ( b ) shows, in a series of graphs, signals related to simulations on the circuit of FIG. 2 performed for the first power element TR 1 . In particular an IGBT transistor whose active area is equal to 10 mm 2 , driven by the control block 10 limiting the output current I COIL to 20 amperes was used.
FIG. 3( a ) relates to the case of the trigger voltage V TRIGGER at the high state of 2.5 volts and FIG. 3( b ) shows the simulation results as the amplitude of the voltage varies.
When the trigger voltage V TRIGGER is 2.5 volts [V(TRIGG — 1)], the output current I(COIL — 1) stays lower than 4 amperes, which is quite lower than the predetermined limitation current, since the actual voltage V(GATE — 1) calculated on the gate terminal G corresponds to about 2.3 volts.
When the trigger signal V TRIGGER reaches a low state, the IGBT transistor TR 1 is disabled and the power accumulated in the primary winding 3 A of a coil transfers to the secondary winding generating a spark on the igniter plug 3 B.
When the current in the collector terminal C of the IGBT transistor TR 1 is too low, the accumulated power can be insufficient for generating the mixture combustion in the explosion chamber, with the subsequent misfiring phenomenon which is, as is well known, very damaging for the motor.
From the simulations of FIG. 3( b ) it can thus be appreciated how the current I COIL , to reach the limitation value of 20 amperes, requires a trigger signal V TRIGGER whose amplitude is no lower than 4 volts.
To overcome the above-mentioned problems, the prior art suggests the use of a charge pump fed by a trigger signal V TRIGGER , capable of generating an output voltage being sufficiently high as to conveniently bias the gate terminal G of the IGBT transistor TR 1 , allowing thus the current I COIL required by the application to be delivered therefrom.
Although this solves the problem, the solution has a serious drawback. The noise generated by the inner oscillator of the charge pump can cause electromagnetic noise making the device incompatible with emission regulations.
Moreover, this noise, which is also reflected on the voltage of collector terminal C, is transferred to the coil secondary winding, by means of the turn ratio, which can generate undesired overvoltages.
To address these problems, it would be thus necessary to further increase the circuit complexity of the control block 10 by inserting filters.
What is desired, therefore, is a control circuit for a smart power device having a reduced amplitude trigger signal, such that a sufficiently high current is produced to avoid ignition problems, but overcomes the problems associated with the prior art solutions described above.
SUMMARY OF THE INVENTION
According to an embodiment of the present invention, an auxiliary current generator capable of delivering an auxiliary current is added to the current output of the control circuit in order to bias, according to the provided specifications, the control terminal of an IGBT power element.
According to an embodiment of the present invention a control circuit for an inductive load driver includes a control block for receiving a trigger signal (V TRIGGER ) and an output coupled to a control terminal of a power element such as an IGBT transistor. An auxiliary current generator delivers a current that is added to the current output by the control block to supply a driving current I GATE to the power element.
According to an embodiment of the present invention, the control block of the inductive load driver is not coupled to an external power supply, so that it can be assembled in simpler and cheaper packages like three pin packages.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
FIG. 1 a schematically shows a first control block, fed by a battery, driving a power element of an electronic device driving an inductive load, according to the prior art;
FIG. 1 b schematically shows a second control block, fed by a trigger signal, driving the power element of the electronic device driving an inductive load, according to the prior art;
FIG. 2 schematically shows the second control block, fed by the trigger signal, driving the power element of the electronic device and wherein a voltage drop introduced by cables and connectors is also shown, according to the prior art;
FIGS. 3( a ) and 3 ( b ) are timing diagrams that show the evolution of voltage and current waveforms obtained by simulating the operation of the electronic device of FIG. 2 , according to the prior art;
FIG. 4 is a cross-sectional diagram of a portion of a semiconductor integrated circuit comprising a power element and bonding pad for the extraction of a collector voltage value;
FIG. 5 schematically shows a control circuit according to an embodiment of the present invention for a power element of an inductive load driver;
FIG. 6 shows a typical operating curve of a JFET structure for being integrated inside the control circuit, according to the present invention; and
FIG. 7 schematically shows a testing circuit for the optional evaluation of a particular configuration of the control circuit of FIG. 5 , according to the present invention.
FIGS. 8( a ) and 8 ( b ) show the result of the simulation of the circuit of FIG. 7 .
DETAILED DESCRIPTION
FIG. 5 shows a control circuit 6 receiving at its input a trigger signal V TRIGGER and a collector voltage value V L and outputting a current value I GATE driving a first power element, particularly an IGBT transistor TR 1 of an inductive driver circuit 9 .
In particular, control circuit 6 comprises a control block 10 receiving, as in the prior art, at its input the trigger signal V TRIGGER and generating a first current I DRIV .
Control circuit 6 also comprises, according to the invention, a current generator block A receiving at its input voltage V L and producing a second current, in particular an auxiliary current I AUX .
According to the invention, the input voltage V L of the control circuit 6 , by means of the auxiliary current I AUX generator block A, is detected at node L, which is the cathode terminal common to two intrinsic diodes D 1 and D 2 located in series between the collector and the emitter of the power element TR 1 of the inductive driver device 9 .
Voltage V L is proportional to the collector voltage of power element TR 1 and it is produced in an area located in the physical structure of the transistor itself as is shown in detail in FIG. 4 .
Referring again to FIG. 5 , according to the present invention, the contributions of the currents—first I DRIV and second I AUX —are added, by means of a logic OR gate 7 , and they output a current I GATE to control the power element TR 1 of inductive load driver 9 .
Power element TR 1 is associated, as already described in the prior art, to a second power element, in particular an IGBT sensing transistor TR SENSE .
FIG. 4 shows the structure used to provide voltage V L from the IGBT transistor TR 1 of inductive load driver 9 , which is coupled to block A, which in turn provides the auxiliary current I AUX . FIG. 4 shows an integrated structure comprising the first power element TR 1 as well as the sensing transistor TR SENSE . A bonding pad 19 is also provided near the edge structure of power element TR 1 in order to provide the value of voltage V L .
The composite structure of the transistor TR 1 comprises, a collector layer 11 , a heavily doped P+ semiconductor layer 12 , and a heavily doped N+ semiconductor layer 13 .
On semiconductor layer 13 a weakly doped N− epitaxial layer 14 is formed including P-type wells 15 . Pairs of N-type active areas with electrodes 18 are formed in wells 15 .
Additional pad 19 is located on the edge of the transistor TR 1 structure. Using pad 19 , the voltage V L of the transistor is provided, which is brought back to the input of the auxiliary current I AUX generator block A.
FIG. 4 also shows diodes D 1 and D 2 coupled together with a common cathode coupled to node “L”.
According to an embodiment of the present invention, by using high voltage technology, such as VIPower® technology, the auxiliary current I AUX generator block A can be realised with a J-FET transistor structure [(I=f(V)] integrated inside the control circuit 6 . This solution has the advantage of pinching at high voltage, as shown in the curve of FIG. 6 .
Referring now to FIG. 7 , a second possible optional solution to realise the auxiliary current I AUX generator block A is the use of a third power element, in particular a JFET transistor TR 2 which can be integrated inside the same IGBT transistor TR 1 of inductive load driver 9 . According to the present invention, in this case, the control circuit 6 can be realised with low voltage technology.
As can be appreciated in FIG. 7 , block A has been realised with a JFET transistor TR 2 monolithically integrated inside the IGBT transistor TR 1 of the inductive load driver 9 .
In the evaluation circuit of the effectiveness of this second solution shown in FIG. 7 , the JFET transistor TR 2 has the control terminal coupled to the emitter E of transistor TR 1 , a first conduction terminal connected to the cathode node L being common to the two intrinsic diodes D 1 and D 2 , and a second conduction terminal coupled to the gate terminal G of the transistor TR 1 of the inductive load driver 9 . A diode D 3 is inserted between the second conduction terminal of the JFET transistor TR 2 and the gate terminal G of the transistor TR 1 , while a Zener diode Dz is coupled between the second conduction terminal of the JFET transistor TR 2 and GND.
An operational amplifier OP 1 is also provided, serving as current limiter, with an inverting input (−) coupled to a generator block 8 of reference voltage VREF, receiving at its input the trigger signal V TRIGGER , a non-inverting input (+) coupled to the emitter terminal E SENSE of the sensing transistor TR 1 SENSE , and an output coupled to the gate terminal G of transistor TR 1 .
The voltage reference block 8 and the operational amplifier OP 1 serving as current limiter allow the limitation function of the highest current output from the first transistor TR 1 to be provided.
To implement the evaluation circuit of the effectiveness of this second solution shown in FIG. 7 , it is necessary that control block 10 have the following features: it delivers the current I DRIV when the input voltage V TRIGGER is higher than the output voltage thereof, coinciding with the voltage Vg of the control terminal G of the transistor TR 1 ; and it does not absorb current, similarly to a diode.
FIGS. 8( a ) and 8 ( b ) show the result of the simulation of the circuit of FIG. 7 . In FIG. 8( a ) the voltage V(GATE — 1), which can be applied on the control terminal G of the transistor TR 1 , can overcome the trigger voltage V(TRIGG — 1) at the high state, which is the supply voltage of the control block, allowing the transistor TR 1 to operate with a high output current.
The control terminal G capacitance is charged in two following steps: in a first step the current I DRIV charges the control terminal G of transistor TR 1 , until the gate voltage is lower than the V_TRIGGER voltage at the high state; and in a second step, when I DRIV is zero, the control terminal G of transistor TR 1 is charged only by current I AUX coming from the JFET transistor TR 2 .
The voltage on control terminal G of transistor TR 1 is at the end limited by operational amplifier OP 1 serving as current limiter, operating in adjustment, in order to have the predetermined coil current I(COIL — 1).
In FIG. 8( b ) the limitation current is always reached, as the amplitude of the trigger voltage V TRIGGER varies. As the amplitude of the signal V TRIGGER varies, the corresponding voltage V(GATE) of the control terminal G of the transistor TR 1 reaches a value which is sufficient to let the collector current reach the limitation value.
This type of solution allows the device to reach the nominal current even in the worst case, in order to always charge the coil in an optimal way, and to have in the turn-off step the convenient amount of energy available.
According to an embodiment of the present invention a control circuit is provided for power devices driven by input signals having, at a high logic state, a non-optimal voltage value.
While there have been described above the principles of the present invention in conjunction with a preferred embodiment thereof, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. Such modifications may involve other features which are already known per se and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure herein also includes any novel feature or any novel combination of features disclosed either explicitly or implicitly or any generalization or modification thereof which would be apparent to persons skilled in the relevant art, whether or not such relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as confronted by the present invention. The applicants hereby reserve the right to formulate new claims to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.
|
A control circuit for an inductive load driver includes a control block activated by a trigger signal and an output coupled to the control terminal of a power element. The control circuit includes an auxiliary current generator capable of delivering a current that is added to the current provided by control block and the sum of these currents is provided to the control terminal of the power element. The auxiliary current generator enables the inductive load driver to operate normally even though the trigger voltage is less than an optimal voltage value.
| 5
|
This application claims the benefit of U.S. Provisional Application No. 60/231,048 filing date Sep. 8, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention includes new polymers that comprise adjacent saturated carbon atoms, either integral or pendant to the polymer backbone, that have a substantially gauche conformation. Polymers of the invention are particularly useful as a resin binder component of chemically-amplified positive-acting resists that can be effectively imaged at short wavelengths such as sub-200 nm and preferably about 157 nm. In such short-wavelength imaging applications, polymers of the invention that have a population of dihedral angles of adjacent saturated carbon atoms that are enriched in substantially gauche conformations can provide reduced undesired absorbance of the high energy exposure radiation.
2. Background
Photoresists are photosensitive films used for transfer of images to a substrate. A coating layer of a photoresist is formed on a substrate and the photoresist layer is then exposed through a photomask to a source of activating radiation. The photomask has areas that are opaque to activating radiation and other areas that are transparent to activating radiation. Exposure to activating radiation provides a photoinduced chemical transformation of the photoresist coating to thereby transfer the pattern of the photomask to the photoresist-coated substrate. Following exposure, the photoresist is developed to provide a relief image that permits selective processing of a substrate.
A photoresist can be either positive-acting or negative-acting. For most negative-acting photoresists, those coating layer portions that are exposed to activating radiation polymerize or crosslink in a reaction between a photoactive compound and polymerizable reagents of the photoresist composition. Consequently, the exposed coating portions are rendered less soluble in a developer solution than unexposed portions. For a positive-acting photoresist, exposed portions are rendered more soluble in a developer solution while areas not exposed remain comparatively less developer soluble. Photoresist compositions are described in Deforest, Photoresist Materials and Processes, McGraw Hill Book Company, New York, ch. 2, 1975 and by Moreau, Semiconductor Lithography, Principles, Practices and Materials, Plenum Press, New York, ch. 2 and 4.
While currently available photoresists are suitable for many applications, current resists also can exhibit significant shortcomings, particularly in high performance applications such as formation of highly resolved sub-half micron and sub-quarter micron features.
Consequently, interest has increased in photoresists that can be photoimaged with short wavelength radiation, including exposure radiation of about 250 nm or less, or even about 200 nm or less, such as wavelengths of about 193 nm. Use of such short exposure wavelengths can enable formation of smaller features. Accordingly, a photoresist that yields well-resolved images upon 248 nm or 193 nm exposure could enable formation of extremely small (e.g. sub-0.25 m) features that respond to constant industry demands for smaller dimension circuit patterns, e.g. to provide greater circuit density and enhanced device performance.
Recently, use of an F 2 excimer laser imaging source which provides radiation having a wavelength of about 157 nm, has been considered as a route to manufacture of even smaller features. See, generally, Kunz et al., SPIE Proceedings (Advances in Resist Technology), vol. 3678, pages 13–23 (1999).
SUMMARY OF THE INVENTION
We have now found novel polymers and photoresist compositions that comprise the polymers as a resin binder component. The photoresist compositions of the invention can provide highly resolved relief images upon exposure to extremely short wavelengths, particularly sub-200 nm wavelengths, and even sub-170 nm or sub-160 nm wavelengths, such as 157 nm.
More particularly, polymers of the invention have adjacent carbons that can a dihedral angle of less or greater than 180°, preferably a dihedral angle of less than about 170°, about 160° or about 150°, or less than about 140°, more preferably less than about 130°, about 120°, about 110°, about 100°, about 90°, about 80° or about 70°. A dihedral angle of about 60° (i.e. gauche conformation) is particularly preferred. The term “dihedral angle” as used herein means the same as the term “torsion angle”, both of which terms are discussed in Carey and Sundberg, Advanced Organic Chemistry , Part A: page 100 et seq. (2 nd ed. Plenum Press).
Corresponding dihedral angles that are greater than 180° also are preferred, i.e. preferred are dihedral angles of adjacent carbon atoms or greater than about 190°, more preferably greater than about 200°, about 210°, about 220°, about 230°, about 240°, about 250°, about 260°, about 270°, about 280°, about 290° or about 300°. A dihedral angle of about 300° is particularly preferred. To further illustrate, set forth immediately below are schematic depictions of the undesired (i.e. 180°, trans or anti) and preferred (i.e. less than or greater than 180°) conformations including gauche conformations of 60° and 300° and other suitable conformations of other than 180°.
Trans or Anti Conformation
Gauche and Other Preferred Conformations
By reducing the content of trans conformations of a polymer, the polymer can exhibit reduced absorption of short wavelength radiation, particularly sub-160 nm radiation such as 157 nm radiation. Without being bound by theory, with saturated carbons positioned in trans conformations, such high energy radiation can be absorbed via the sigma→sigma* absorption band. That absorption band is less accessible where adjacent carbons are positioned in other than trans conformation (i.e. 180° dihedral angle), and the absorption band is particularly remote where adjacent carbons are in substantially gauche conformations, i.e. dihedral angles of about 60° or 300°.
Such offset configurations can be provided by a number of approaches. For instance, to offset carbons of a polymer backbone, a variety of groups may be incorporated into the polymer backbone to provide such preferred dihedral angles (i.e. less than or greater than 180°). More particularly, one or more hetero atoms, particularly N, O or S atoms, may be polymer backbone members (i.e. insertion of hetero atoms into the carbon backbone skelton), which will can inhibit neighboring carbon atoms from adopting a substantially trans conformation. The polymer backbone also may comprise alicyclic groups, such as cyclohexyl or cyclopentyl groups, which can inhibit neighboring carbon atoms from adopting a trans conformation. Such groups may be introduced into a polymer backbone by co-polymerization of corresponding monomers such as a vinyl ether, vinyl amine, vinyl sulfide, vinyl sulfinyl or vinyl sulfonyl compound; a divinyl cyclohexyl ether; divinyl cyclopentyl ether; and the like. Backbones of polymers of the invention suitably are at least substantially composed of carbon atoms, more particularly, at least about 60, 70, 80, 90, 95 or 98 mole percent of backbone atoms are carbon.
The polymer also may be appropriately substituted to provide other than a trans conformation of adjacent carbon atoms of a polymer backbone. For example, one carbon of the polymer backbone may be substituted with a hydrogen bond donor (e.g. hydroxy) and an adjacent carbon can be substituted with a hydrogen bond acceptor (e.g. cyano), which will promote hydrogen bonding of those two groups that will promote a conformation of the substituted carbons that is other than trans. Adjacent carbons also could be substituted with groups that sterically promote a conformation that is other than 180°, e.g. one carbon of the backbone could be substituted with a bulky group, e.g. an alkyl moiety having 3, 4, 5, 6 or more carbons such as t-butyl, sec-pentyl, cyclopentyl, cyclohexyl and the like.
Pendant polymer groups also may contain groups that will disrupt neighboring carbon atoms from adopting a trans conformation. For instance, polymers may contain pendant photoacid-labile groups that can comprise a moiety that contains adjacent saturated carbon atoms that are in an other than trans conformation, i.e. other than 180° as discussed above. More particularly, a polymer may contain pendant alicyclic groups such as pendant cyclohexyl or cyclopentyl groups, where adjacent ring carbons are in other than a trans conformation, and typically are in a substantially gauche conformation.
In yet another approach, a polymer may contain unsaturated groups, either integral to the polymer backbone or as a pendant group, which unsaturated group can position neighboring adjacent saturated carbons in other than substantially trans conformation. For instance, a terminal acetylenic compound can be polymerized to provide a carbon-carbon double bond either integral or pendant to the polymer backbone, which double bond can prevent neighboring adjacent saturated carbons from adopting a trans conformation.
Polymers of the invention preferably will have a significant portion of adjacent saturated carbons in other than a trans conformation. For instance, preferably at least about 5 mole percent of adjacent carbon atoms of a polymer will have dihedral angles of other than 180°, more preferably about 10, 15, 20 or 25 mole percent of adjacent carbon atoms will have dihedral angles other than 180°. Particularly suitably will be polymers where at least about 30, 40, 50, 60, 70, 80, or 90 mole percent of adjacent carbon atoms will have dihedral angles other than 180°. Even more preferred is where such polymers have a significant portion of adjacent saturated carbon atoms that are in a substantially gauche conformation, i.e. within about 5°, 10°, 15° or 20° degrees of a dihedral angle of about 60° or about 300°. More particularly, preferred are polymers where at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70 or 80 mole percent of adjacent carbon atoms of the polymer have such a substantially gauche conformation.
For a polymer having a carbon-containing backbone, preferably at least about 5 mole percent of adjacent carbon atoms of the backbone will have dihedral angles of other than 180°, more preferably about 10, 15, 20 or 25 mole percent of adjacent carbon atoms will have dihedral angles other than 180°. Particularly suitably will be polymers where at least about 30, 40, 50, 60, 70, 80, or 90 mole percent of adjacent carbon atoms of the backbone have dihedral angles other than 180°. Even more preferred is where such polymers have a significant portion of adjacent saturated carbon atoms that are in a substantially gauche conformation, i.e. within about 5°, 10°, 15° or 20° degrees of a dihedral angle of about 60° or about 300°. More particularly, preferred are polymers where at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70 or 80 mole percent of adjacent carbon atoms of the backbone have such a substantially gauche conformation.
It is also preferred not to have “extended runs” of carbons in trans conformations, e.g. where 10, 15, 20, 30, 40, 50, 80, 100, 150 or 200 or more adjacent carbons are in a trans conformation. Such extended trans conformation can be highly absorbing of short wavelength radiation such as 157 nm.
Polymers of the invention may contain a variety of groups. For example, polymers of the invention suitably may contain polymerized cyclic olefin units such as optionally substituted norbornene units; acrylate groups (which includes 2-alkylacrylate groups such as methacrylate herein) such as methyl methacrylate, ethyl methacrylate, and the like; cyano groups such as provided by polymerization of acrylonitrile or methacrylonitrile.
Polymers of the invention also may contain a variety of aromatic groups, preferably substituted with one or more electron-withdrawing groups to reduce undesired absorbance of the short wavelength radiation such as 157 nm by the aromatic group. More particularly suitable are polymers that contain phenyl repeat units, particularly phenolic repeat units that have one or more electron-withdrawing ring substituents such as halogen particularly fluoro, perhaloalkyl particularly perhaloC 1-8 alkyl such as perfluoroC 1-8 alkyl e.g. trifluoromethyl and the like; cyano; nitro; sulfinyl; sulfonyl; etc. Other suitable aromatic groups for polymer repeat units of the invention include polyaromatichydrocarbons e.g. naphthyl, anthracenyl, and the like, preferably substituted at one or more ring positions by electron-withdrawing groups such as those mentioned directly above with respect to phenyl units.
Photoresists of the invention in general comprise a polymer of the invention as discussed above and a photoactive component. Generally preferred resists of the invention are deblocking positive systems, often referred to as chemically amplified resists where a photogenerated acid induces a chemical reaction of one or more components of the resist. Typically preferred is where the resin contains photoacid-labile groups, e.g. a photoacid-labile ester where acid deblocks the ester to provide a polar carboxy group in exposed regions of the resist coating layer. Preferably, such ester groups have adjacent carbon atoms that are in a conformation other than trans, preferably a substantially gauche conformation. For example, a resin may contain polymerized units of cyclohexylacrylate, cyclohexylmethacrylate, cyclopentylacrylate, cyclopentylmethacrylate, tert-butylacrylate, tert-butylmethacrylate, and the like. Those ester groups can undergo a deblocking in the presence of photogenerated acid. For many systems, polymerizered alkyl acrylate (which includes methacrylates and other substituted acrylates) are preferred photoacid-labile moieties of a positive resist. Other suitable acid-labile moieties will include polymerized acetal or ketal moieties, acid-labile moieites that are substituents of phenyl groups, such as photoacid-labile esters (particularly alkyl ester such as cyclohexylesters or cyclopentyl esters), acetals and ketals that are grafted onto phenolic hydroxy moieties.
In addition to positive resists, negative-acting photoresists are also provided that comprise a resin as disclosed above.
The invention also includes methods for forming relief images, including methods for forming a highly resolved relief image such as a pattern of lines where each line has essentially vertical sidewalls and a line width of about 0.40 microns or less, or even about 0.25, 0.20, 01.5 or 0.10 microns or less. The invention further comprises articles of manufacture comprising substrates such as a microelectronic wafer having coated thereon the photoresists and relief images of the invention. Other aspects of the invention are disclosed infra.
DETAILED DESCRIPTION OF THE INVENTION
As discussed above, the invention provides new polymers that can exhibit reduced absorbance (i.e. greater transparency) of high energy radiation, such as radiation having a wavelength of less than 170 or 160 nm, particularly 157 nm.
Polymers of the invention may be homopolymers, or more typically are copolymers that contains two or more distinct repeat units, generally two, three, four or five distinct repeat units. Polymers that have two or three distinct repeat units are particularly preferred. At least one of the repeat units should contain a moiety as discussed above that can inhibit adjacent saturated carbons from adopting a substantially trans conformation.
Polymers of the invention may be substantially free of aromatic groups. More particularly, preferred polymers that are substantially free of aromatic groups contain less than about 5 mole percent aromatic groups, more preferably less than about 1 or 2 mole percent aromatic groups, more preferably less than about 0.1, 0.08, 0.04 and 0.02 mole percent aromatic groups and still more preferably less than about 0.01 mole percent aromatic groups. Particularly preferred polymers are completely free of aromatic groups. Aromatic groups can be highly absorbing of sub-200 nm radiation and thus can be undesirable for polymers used in photoresists imaged with such short wavelength radiation.
Suitable polymers that are substantially or completely free of aromatic groups suitably contain acrylate units such as photoacid-labile acrylate units as may be provided by polymerization of methyladamanatylacrylate, methyladamanylmethacrylate, ethylfencylacrylate, ethylfencylmethacrylate, and the like; fused non-aromatic alicyclic groups such as may be provided by polymerization of a norbornene compound or other alicyclic compound having an endocyclic carbon-carbon double bond; an anhydride such as may be provided by polymerization of maleic anhydride; and the like.
Polymers of the invention may contain aromatic groups. As discussed above, such aromatic groups preferably have one or more ring substituents that are electron-withdrawing groups, e.g. halogen particularly fluoro; or perhaloalkyl, particularly perfluoroalkyl such as trifluoromethyl.
As discussed above, copolymers are preferred resins of the invention. Such copolymers are suitably prepared by polymerization of two or more distinct monomers or oligomers, where at least one of the monomers or oligomers can inhibit adjacent saturated carbon atoms from adopting a substantially trans confoirmation. For example, the following monomers can be co-polymerized: a vinyl phenol preferably substituted with one or more electron withdrawing groups such as fluoro, a styrene preferably substituted with one or more electron withdrawing groups such as fluoro or perfluoroalkyl, and an acrylate with a ester group that is in a non-trans conformation such as cyclohexyl methacrylate (H 2 C═C(CH 3 )CO 2 C 6 H 11 ).
Polymers of the invention can be prepared by free radical polymerization, e.g., by reaction of a plurality of monomers to provide the various units as discussed above in the presence of a radical initiator under an inert atmosphere (e.g., N 2 or argon) and at elevated temperatures such as about 70° C. or greater, although reaction temperatures may vary depending on the reactivity of the particular reagents employed and the boiling point of the reaction solvent (if a solvent is employed). See Example 1 which follows for exemplary reactions conditions. Suitable reaction temperatures for any particular system can be readily determined empirically by those skilled in the art.
A reaction solvent may be employed if desired. Suitable solvents include alcohols such as propanols and butanols and aromatic solvents such as benzene, chlorobenzene, toluene and xylene. Dimethylsulfoxide and dimethylformamide are also suitable. The polymerization reaction also may be run neat.
A variety of free radical initiators may be employed to prepare the copolymers of the invention. For example, azo compounds may be employed such as azo-bis-2,2′-isobutyronitrile (AIBN) and 1,1′-azobis(cyclohexanecarbonitrile). Peroxides, peresters, peracids and persulfates also can be employed.
Preferably a polymer of the invention will have a weight average molecular weight (Mw) of 1,000 to about 100,000, more preferably about 2,000 to about 30,000 with a molecular weight distribution (Mw/Mn) of about 3 or less, more preferably a molecular weight distribution of about 2 or less. Molecular weights (either Mw or Mn) of the polymers of the invention are suitably determined by gel permeation chromatography.
As discussed above, the polymers of the invention are highly useful as the resin binder component in photoresist compositions, particularly chemically-amplified positive resists. Photoresists of the invention in general comprise a photoactive component and a resin binder component that comprises a polymer as disclosed herein.
The resin binder component preferably is used in an amount sufficient to render a coating layer of the resist developable with an aqueous alkaline developer.
The resist compositions of the invention also comprise a photoacid generator (i.e. “PAG”) that is suitably employed in an amount sufficient to generate a latent image in a coating layer of the resist upon exposure to activating radiation. Generally, sulfonate compounds are preferred PAGs, particularly sulfonate salts. Two specifically preferred agents are the following PAGS 1 and 2:
Such sulfonate compounds can be prepared as disclosed in U.S. Pat. No. 5,861,231.
Other suitable sulfonate PAGS including sulfonated esters and sulfonyloxy ketones. See J. of Photopolymer Science and Technology, 4(3):337–340 (1991), for disclosure of suitable sulfonate PAGS, including benzoin tosylate, t-butylphenyl alpha-(p-toluenesulfonyloxy)-acetate and t-butyl alpha-(p-toluenesulfonyloxy)-acetate. Preferred sulfonate PAGs are also disclosed in U.S. Pat. No. 5,344,742 to Sinta et al.
Onium salts are also generally preferred acid generators of compositions of the invention. Onium salts that comprise weakly nucleophilic anions have been found to be particularly suitable. Examples of such anions are the halogen complex anions of divalent to heptavalent metals or non-metals, for example, Sb, Sn, Fe, Bi, Al, Ga, In, Ti, Zr, Sc, D, Cr, Hf, and Cu as well as B, P, and As. Examples of suitable onium salts are diaryl-diazonium salts and onium salts of pnictogen, calcogen and halaogen elements, for example, halonium salts, quaternary ammonium, phosphonium and arsoniium salts, aromatic sulfonium salts and sulfoxonium salts or selenium salts. Examples of suitable preferred onium salts can be found in U.S. Pat. Nos. 4,442,197; 4,603,101; and 4,624,912.
Other useful acid generators include the family of nitrobenzyl esters, and the s-triazine derivatives. Suitable s-triazine acid generators are disclosed, for example, in U.S. Pat. No. 4,189,323.
As mentioned above, negative-acting compositions of the invention are also provided. A negative resist of the invention will comprise a mixture of materials that will cure, crosslink or harden upon exposure to acid, and a photoactive component of the invention. Typically negative resists of the invention contain a resin as disclosed herein together with a photoactive compound and a crosslinker component. The crosslinker can be integral to the resin or a separate component.
Particularly preferred negative acting compositions of the invention comprise a separate crosslinker component and a photoactive component of the invention. The photoactive component is suitably a photoacid generator as discussed above. Preferred crosslinkers include amine-based materials, including melamine, glycolurils, benzoguanamine-based materials and urea-based materials. Melamine-formaldehyde resins are generally most preferred. Such crosslinkers are commercially available, e.g. the melamine resins sold by American Cyanamid under the trade names Cymel 300, 301 and 303. Glycoluril resins are sold by American Cyanamid under trade names Cymel 1170, 1171, 1172, urea-based resins are sold under the trade names of Beetle 60, 65 and 80, and benzoguanamine resins are sold under the trade names Cymel 1123 and 1125.
A optional additive of resists of the invention is an added base, such as tetrabutylammonium hydroxide (TBAH), or a salt of TBAH, which can enhance resolution of a developed resist relief image. The added base is suitably used in relatively small amounts, e.g. about 1 to 20 percent by weight relative to the photoactive component (PAG).
Photoresists of the invention also may contain other optional materials. For example, other optional additives include anti-striation agents, plasticizers, speed enhancers, etc. Such optional additives typically will be present in minor concentration in a photoresist composition except for fillers and dyes which may be present in relatively large concentrations such as, e.g., in amounts of from about 5 to 30 percent by weight of the total weight of a resist's dry components.
Photoresists of the invention can be readily prepared. For example, a resist of the invention can be prepared as a coating composition by dissolving the components of the photoresist (e.g., for a positive resist, the resin and a PAG; for a negative resists, a resin, PAG and crosslinker) in a suitable solvent such as, e.g., a glycol ether such as 2-methoxyethyl ether (diglyme), ethylene glycol monomethyl ether, propylene glycol monomethyl ether; lactates such as ethyl lactate or methyl lactate, with ethyl lactate being preferred; proponiates, particularly methyl propionate, ethyl propionate and ethyl ethoxy propionate; or a ketone such as 2-alkanones or cycloalkanones. Cyclohexanone and 2-heptanone are generally preferred. Typically the solid content of the photoresist varies between 5 and 35 percent by weight of the total weight of the photoresist composition.
The photoresists of the invention can be used in accordance with known procedures. Though the photoresists of the invention may be applied as a dry film, they are preferably applied on a substrate as a liquid coating composition, dried by heating to remove solvent preferably until the coating layer is tack free, exposed through a photomask to activating radiation such as 157 nm or other short wavelength radiation, optionally post-exposure baked to create or enhance solubility differences between exposed and nonexposed regions of the resist coating layer, and then developed preferably with an aqueous alkaline developer to form a relief image. Following development of the photoresist coating over the substrate, the developed substrate may be selectively processed on those areas bared of resist, e.g. by chemically etching or plating substrate areas bared or resist in accordance with known procedures. For the manufacture of microelectronic substrates, e.g. the manufacture of silicon dioxide wafers, suitable etchants include a gas etchant, e.g. a chlorine or fluorine-based etchant such as a CF 4 or CF 4 /CHF 3 etchant applied as a plasma stream.
All documents disclosed herein are incorporated herein by reference. The following non-limiting examples are illustrative of the invention.
EXAMPLE 1
Polymer Synthesis
A polymer of the invention may be suitably prepared as follows. Vinylphenol (1 molar equivalent) cyclohexyl methacrylate (0.5 molar equivalent), and 2,6-difluorostyrene (0.5 molar equivalent) are dissolved in isopropyl alcohol or other solvent. Reaction initiator (azo-bis-2,2′-isobutyronitrile (AIBN)) is added and the reaction is heated until the polymerization is at least substantially complete. Suitably the reaction is heated overnight. The resulting polymer then can be filtered, washed with water and dried.
EXAMPLE 2
Photoresist Preparation and Lithographic Processing
A photoresist of the invention is prepared by mixing the following components with amounts expressed as weight percent based on total weight of the resist compositions:
Resist components
Amount (wt. %)
Resin binder
15
Photoacid generator
3
Cyclohexanone
81
The resin binder is the terpolymer of Example 1 above. The photoacid generator is di-t-butylphenyl iodonium camphor sulfonate. Those resin and PAG components are admixed in cyclohexanone solvent.
The formulated resist composition is spin coated onto HMDS vapor primed 4 inch silicon wafers and softbaked via a vacuum hotplate at 90° C. for 60 seconds. The resist coating layer is exposed through a photomask at 157 nm, and then the exposed coating layers are post-exposure baked at 110° C. The coated wafers are then treated with aqueous alkaline solution to develop the imaged resist layer.
The foregoing description of the invention is merely illustrative thereof, and it is understood that variations and modifications can be effected without departing from the spirit or scope of the invention as set forth in the following claims.
|
This invention relates to resins and photoresist compositions that comprise such resins. Preferred polymers of the invention comprise adjacent saturated carbon atoms, either integral or pendant to the polymer backbone, that have a substantially gauche conformation. Polymers of the invention are particularly useful as a resin binder component of chemically-amplified positive-acting resists that can be effectively imaged at short wavelengths such as sub-200 nm and preferably about 157 nm. In such short-wavelength imaging applications, polymers of the invention that have a population of dihedral angles of adjacent saturated carbon atoms that are enriched in substantially gauche conformations can provide reduced undesired absorbance of the high energy exposure radiation.
| 8
|
BACKGROUND
[0001] Process control valves are used in many industries to control fluid movement for a plethora of reasons. Some of the fluids controlled by such valves are difficult to handle such that their escape from the system is undesirable. Hydrogen Sulfide is one such fluid and will be recognized by those of skill in the art as a gas that one would prefer did not escape the system in which it is housed.
[0002] Traditional process control valves include an open or close lever that is mechanically actuated either manually or by mechanism. While such valves do control flow of the subject fluid, they also suffer from the fact that they contain a dynamic seal between the subject fluid and the environmental atmosphere. This dynamic seal exists about a shaft connected between the valve member itself and the lever. Since dynamic seals require periodic maintenance and represent a potential leak path for the subject fluid to reach environmental atmosphere and since as has been stated above it would be desirable to provide systems that more robustly contain the subject fluid within the system in which they are housed, the art would well receive alternate process control valves that improve confidence of containment.
SUMMARY
[0003] A thermo-hydraulically actuated valve including a housing; a closure member capable of preventing and permitting fluid flow through the housing; an actuation fluid chamber disposed at the housing and sealed from an external environment; a motive force transmitter in force transmissive communication with the closure member, the transmitter being in fluid communication with the actuation fluid chamber; and a heating element in thermal communication with the actuation fluid chamber, the valve being devoid of a dynamic seal between an area of the valve to be contacted by a managed fluid within the valve and an environment outside of the valve.
[0004] A thermo-hydraulically actuated valve including a housing devoid of a dynamic seal between a managed fluid area of the valve and an environment outside of the valve; a closure member in the housing; an actuation fluid in pressure communication with the closure member; and an element capable of causing a change in the pressure of the actuation fluid.
[0005] A thermo-hydraulically actuated valve including a housing devoid of a dynamic seal between a managed fluid area of the valve and an environment outside of the valve; a closure member in the housing; a first actuation fluid in pressure communication with the closure member configured to have a motive effect with respect to the closure member in one direction; a second actuation fluid in pressure communication with the closure member configured to have a motive effect with respect to the closure member in another direction; a first element capable of causing a change in the pressure of the first actuation fluid; and a second element capable of causing a change in the pressure of the second actuation fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0007] FIG. 1 is a Thermo-Hydraulically Actuated Process Control Valve disclosed herein in a closed position;
[0008] FIG. 2 is the Thermo-Hydraulically Actuated Process Control Valve of FIG. 1 in an open position;
[0009] FIG. 3 is a representation of an alternate embodiment of the valve disclosed herein;
[0010] FIG. 4 is a representation of another alternate embodiment of the valve disclosed herein;
[0011] FIG. 5 is a representation of another embodiment of the valve disclosed herein;
[0012] FIG. 6 is a representation of another embodiment of a valve disclosed herein in an closed position;
[0013] FIG. 7 is a representation of the embodiment of FIG. 6 disclosed herein in a open position;
[0014] FIG. 8 is a representation of another embodiment of a valve disclosed herein in an open position; and
[0015] FIG. 9 is a representation of the embodiment of FIG. 8 disclosed herein in a closed position.
DETAILED DESCRIPTION
[0016] Referring to FIG. 1 , a process control valve 10 includes a tubular housing 12 that is connectable in series with other tubular members (not shown) that are a part of an overall fluid management system. Within the housing 12 is a closure member 14 capable of preventing and permitting managed fluid flow though the housing, such as a flapper. The closure member is in communication with a motive force transmitter 15 , which is itself in operable communication with an actuation fluid discussed below.
[0017] In the embodiment illustrated in FIG. 1 , the flapper 14 is pivotable from a closed position to an open position about pivot 16 . The pivot 16 is connected to the housing 12 so that a flow tube 18 , in the illustrated embodiment will force the flapper 14 open upon stroking of the flow tube 18 . A support 20 is schematically illustrated that is interactive with a power spring 22 connected to the flow tube 18 at flange 24 . The flow tube when moved to the right of the Figure will cause compression of the spring 22 between the support 20 and the flange 24 . The flow tube 18 will also urge the flapper 14 to the open position. If a motive force acting on the flow tube to compress the power spring 22 is withdrawn, the spring will move the flow tube 18 toward the left of the figure and allow a torsion spring (not shown) within the pivot 16 to close the flapper 14 . The motive force alluded to is transmitted to the flange 24 via a piston rod 26 that is disposed within a piston cylinder 28 and includes a piston 30 . The piston 30 includes a dynamic seal thereabout (not shown) such as a piston ring or set of rings to allow the piston to respond to fluid pressure acting thereon. It will be understood that although a discrete piston is shown, more of these may be employed or an annular piston might be substituted therefor. The other side of the piston 30 is exposed to an actuation fluid 31 that is contained within a sealed chamber 32 . In the illustrated embodiment, the chamber is an annular chamber but it is to be understood that any shape is acceptable. The chamber is penetrated, in the embodiment of FIGS. 1 and 3 , by a static seal 34 that admits at least one of a heating element 36 / 136 and/or energy supply conduit 35 . It is to be understood that the element or conduit are examples and that other things could also be admitted via the seal 34 as the particular application might require. Note however, in an alternate embodiment illustrated in FIG. 4 that the heating element 236 is disposed entirely outside of the chamber 32 and requires no penetration of the chamber 32 . Power and or communication with the element 236 is supplied via line 237 entirely outside of the chamber 32 . If a particular embodiment using heating element 236 has no other reason for a penetration of the chamber 32 , then no seal 34 would be needed in such embodiment. The embodiment of FIG. 4 otherwise works identically to that of the other embodiments herein including any optional configurations.
[0018] It will be appreciated that other things could also be admitted through this seal 34 if desired depending upon what might be necessary or desirable for a particular application. In the illustrated embodiment, also admitted is a communication line 38 connected to a position sensor 40 . Because the seal 34 is static in nature, there is no significant possibility of a leak. The seal must suffer no dynamic capability and hence is by definition more reliable.
[0019] The position sensor may be a magnetic type or other proximity sensor that allows for a confirmation of the location of the flow tube 18 .
[0020] For clarity, it is noted that the element 36 in FIG. 1 is a rod type element and the element 136 in FIG. 3 is annular configured. In each case, the element functions to heat the actuation fluid.
[0021] In order to increase fluid pressure within chamber 32 , the heating element 36 / 136 is energized and causes the temperature of the actuation fluid such as hydraulic fluid in chamber 32 to increase leading to expansion thereof. The coefficient of thermal expansion of the actuation fluid may be selected (by selection of a suitable fluid or by chemically modifying a fluid to custom tailor the coefficient of thermal expansion of the fluid.) as desired to create the degree of motive force needed for the application. Upon the heating of the fluid in chamber 32 , the piston 30 is urged toward the flapper 14 thereby causing the rod 26 to bear against the flange 24 and force the flow tube 18 to move toward the flapper 14 and to push the flapper 14 to the open position as shown in FIG. 2 . Cooling of the fluid in chamber 32 will allow the flow tube to return to the position in FIG. 1 pursuant to the power spring 22 urging the flow tube 18 to an unactuated position.
[0022] It is to be appreciated that the exact configuration of the invention is not limited to that illustrated in the drawings. Rather, the concept of the invention has broader reach in that it requires a fluid in a chamber that can be heated so that the fluid pressure in the chamber increases whereby the fluid causes the piston that ultimately acts on a flapper or other valve member to open the same. The use of heat and an actuation fluid to provide motive force for the change in position of a valve means that there need be no dynamic seals in the system and hence that there can be no leaks of the managed fluid within the system to the environment.
[0023] In one embodiment, it is noted that the actuation fluid 31 is pre pressurized so that the amount of thermal expansion needed for actuation of the valve is less. This of course translates to less needed power for the heating element as the temperature increase necessary in the actuation fluid will be comparatively less due to the preexisting pressurization of the actuation fluid. Such pressurization of the fluid may be accomplished at manufacture of the valve or could be applied on site, but in the latter embodiment a static seal will be required in the chamber. In the event a static seal is already supplied as in the FIG. 1 or 3 embodiments, there is no additional seal required but in the case of FIG. 4 , a seal would be needed where one was not before required.
[0024] In another embodiment, referring to FIG. 5 , the valve is again prepressurized but also included is a pressure dump configuration 350 so that the valve can be quickly closed. The dumped pressure can be to anywhere that is convenient but in keeping with the concept of having fewer seals (and no dynamic ones) between the managed fluid and atmosphere, the dump may be to a dump chamber 352 having a predetermined lower pressure than the pressure of the actuation fluid. The chamber will itself comprise a valve 354 of some type to admit the pressurized actuation fluid in the event a dump is desired. This may be by way of burst disk, such that increasing the pressure of the actuation fluid will automatically at a predetermined pressure threshold cause the valve to close due to rapid depressurization of the chamber 332 . Alternately this may be by way of a remotely controllable valve in the same location 354 such that upon command the valve will open and reduce the actuation fluid pressure by flooding the dump chamber 352 . The valve 354 may be externally powered thought the seal 334 or may use local power source that does not require a seal 334 and as such would be used in the configuration of FIG. 4 .
[0025] Regardless of which type of valving method or mechanism is used to admit fluid to the dump chamber 352 , immediately upon opening of the chamber, the actuation fluid pressure will drop due to the effectively increased volume of the chamber 332 (volume of 332 plus volume of 352 ).
[0026] Referring again to the FIG. 4 embodiment, it is to be understood that the heating element 236 illustrated therein may be an inductive heating element.
[0027] It should be understood that it is possible not only to actuate the closure member to open and closed positions within the embodiments hereof but is also possible to actuate the closure member to any position between open and closed if desired depending upon fluid pressure applied to the piston.
[0028] It is further to be understood that there is no requirement that the valve as disclosed herein be of a fail-safe closed design. There is no requirement that the power spring be incorporated at all. In view hereof, an alternative embodiment (see FIGS. 6 and 7 ) utilizes two configurations of heating elements and volumes to move the flow tube in opposing directions based upon which fluid volume is energized. Reference to FIGS. 6 and 7 will make the concept clear where numerals as disclosed above are retained for one side of the device and four hundred series similar numerals are used to denote the mimicked components that will be positioned to actuate in a direction opposed to the first set of components. More specifically, and with direct reference to FIGS. 6 and 7 , a reader having understood the foregoing disclosure will recognize the components numbered on the left side of the Figures. The reader will also understand the four hundred series numbers on the right side of the Figures. It is noted that the fluid volumes 31 and 431 are separate so that thermal input thereto will be substantially restricted to one of the sets of components. Components with four hundred series numerals are introduced below in list form for convenience of the reader: additional actuation fluid volume 431 , heating element 436 (note other heating means as described herein are applicable to this embodiment as well as those in which they are illustrated), piston 430 /and rod 426 . These are configured such that when actuated the components identified provide a motive force to retract the flow tube 418 , consequently enabling the closure member 414 to return to the closed position. The functional valve condition (open or closed) in this alternative embodiment will correspond to that actuation fluid volume which has been selectively and exclusively energized.
[0029] Referring to FIGS. 8 and 9 , it is easily recognized that the embodiment is similar to the foregoing FIGS. 6 and 7 but the distinction therefrom, i.e. the ball valve in substitution for the flapper is equally employable for any of the other embodiments illustrated herein where a flapper is illustrated. Ball valve 500 is illustrated in an open position in FIG. 8 and a closed position in FIG. 9 . The motive force to move the ball valve 500 in one direction or the other is provided by the same components as discussed with respect to FIGS. 6 and 7 . In addition, it will be appreciated that either of the sets of components in those figures could be substituted for by a spring configuration such as in FIG. 1 . In embodiments where the flapper is substituted by the ball valve 500 , the flow tube 518 causes the ball valve to rotate to either a closed position from an open position or an open position from a closed position by means of rotation pins 501 incorporated on the flow tube 518 and grooves 503 on the exterior of the ball 505 . Pivot pins 507 are also incorporated on the exterior of the ball 505 at its rotational axis. As the Flow Tube 518 extends and retracts during actuation, the rotation pins 501 engage the exterior grooves 503 on the ball causing the ball to rotate between the open and closed position. The configuration may also incorporate a means of translation of the ball relative to the ball seat, in addition to the rotational action described above.
[0030] While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
|
A thermo-hydraulically actuated valve including a housing; a closure member capable of preventing and permitting fluid flow through the housing. An actuation fluid chamber disposed at the housing and sealed from an external environment. A motive force transmitter in force transmissive communication with the closure member. The transmitter being in fluid communication with the actuation fluid chamber; and a heating element in thermal communication with the actuation fluid chamber. The valve being devoid of a dynamic seal between an area of the valve to be contacted by a managed fluid within the valve and an environment outside of the valve.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to bulkheads for vehicle bodies containing refrigeration systems in general. More specifically to refrigeration unit protecting and air flow duct bulkheads that collapse to reduce the overall depth.
2. Description of Prior Art
Previously, bulkheads have been used in conjunction with refrigerated trucks and trailers. Although these bulkheads are of similar construction, there are two basic uses. The first is to isolate the interior into compartments to provide different environmental conditions of temperature and humidity or to reduce the volume being refrigerated. The second purpose of a bulkhead is to protect a mechanical vapor cycle refrigeration unit from physical damage during loading and load shifting while operating over the road. Further, the bulkhead provides an air passageway for the cooled air to enter the return side of the evaporator coil when a load is touching the interior front wall. This invention is related to the latter utility with prior art limited to fixed bulkheads constructed integral with the trailer wall. These are usually fabricated of a wood or metal structure attached vertically and plywood or composition material affixed to the exposed surface forming a protective shield with vertical openings in between. The plywood is located a distance up from the floor, providing an opening for the return air. Other art utilizes a series of rails usually of structural metal located strategically on the front wall to accomplish the same purpose, except the plywood is omitted.
Learmont in U.S. Pat. No. 3,057,284 teaches a movable bulkhead for the former purpose hinging from the top to compartmentize the trailer with a propeller fan moving air from one compartment to the other. The bulkhead also moves forward and aft on rollers with tracks embedded longitudinally into the trailer walls. The apparatus also hinges from the top and swings upward to the ceiling for storage. This top hinging may become dangerous when worn or improperly latched and the thickness of the bulkhead remains the same regardless of its position. U.S. Pat. No. 2,633,714 issued to Wehby discloses interior doors that open at the center and swing planar to the walls, however, the volume of the door is not reduced but is only relocated to the interior sides of the trailer.
Other patents which lend themselves to refrigerated trailer bulkheads and may be considered material in the sense of prior art with respect to this application are U.S. Pat. Nos. 1,704,758 of Meinhardt, and 2,895,309 issued to Kuhlmeier. However, neither of these are considered to have teachings which disclose or suggest the overall arrangement of this invention.
SUMMARY OF THE INVENTION
With the advent of the energy shortage, enlarging the interior cubic foot area of trailers and truck bodies has become increasingly important. As government regulations have limited the overall size of over-the-road equipment, the efficiency of the loading and interior length has been carefully studied. Refrigerated trailers are often used for dry back hauls or returning from their destination with a load of non-refrigerated freight. The available interior length, especially with items that will "cube out" or fill the interior completely before it "grosses out" in maximum allowable gross vehicle weight, becomes a major consideration.
The refrigeration industry has reacted to this problem by developing nosemounted mechanical refrigeration units that protrude into the trailer interior only a fraction of the distance, heretofore considered acceptable. Even further, units that are completely flush with the front wall are now marketed.
Another factor is the increasing use of palletized loads. The pallet is loaded outside of the trailer, the approximate height and unitary width of the interior, creating a problem if the front end of the trailer is unduly restricted. A few additional inches in interior trailer length may permit the loading of an additional pallet.
It is, therefore, the primary object of this invention to overcome this problem by providing a collapsible bulkhead. The bulkhead not only protects the evaporator from physical damage and allows optimum return air flow, but collapses against the wall providing additional loading space.
An important object reduces the air flow to the evaporator only approximately 25% when the bulkhead is collapsed. This is sufficient volume to operate a refrigeration unit without adverse effect if the bulkhead is inadvertently left collapsed.
Another object provides the use of the invention with not only flush or minimum evaporator penetration units, but also full evaporator extending refrigeration systems. The bulkhead may be installed below the evaporator with cargo loaded underneath utilizing effectively the collapsible advantage.
Still another feature allows the use of independent vertical members for palletized cargo in closed containers where the air flow cannot be blocked due to the solid load configuration. Collapsing may be accomplished singally by individual manual operation. An optional feature allows the members to be attached together with a solid partition creating an air flow duct and offering protection to the refrigeration unit when smaller objects are loaded or when stacking individual containers at the front wall.
Openings in the extending support members line-up with similar holes in the base to allow a tool to be inserted for attaching the base to the wall without dissembly of the apparatus. A further object provides a bulkhead with sufficient structural integrety to withstand load shifting while either extended or retracted without relying on the flow structure or other peripheral trailer members for support.
Finally, the apparatus may be easily collapsed by one person. This is accomplished by lifting up on the individual extending support members, or attached partition, and locking in place with a friction latch in its upwardly retracted position. This requires no rotating or threaded fasteners or removable hardware that may be lost or misplaced.
These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial isometric view of the preferred embodiment with a cut-away showing the bulkhead attached to the front wall and the rear of the trailer omitted for clarity.
FIG. 2 is a partial isometric view of the invention illustrated in the extended position.
FIG. 3 is a partial isometric view of the invention depicted in the collapsed condition.
FIG. 4 is a top view taken along lines 4--4 of FIG. 2 showing the invention extended.
FIG. 5 is a top view taken along lines 5--5 of FIG. 3 showing the invention collapsed.
FIG. 6 is a view taken along lines 6--6 of FIG. 1 showing the bulkhead without the partition.
FIG. 7 is a partial isometric view of the preferred embodiment remote from the trailer.
FIG. 8 is a view taken along lines 8--8 of FIG. 7 in the extended position.
FIG. 9 is a view taken along lines 9--9 of FIG. 7 in the collapsed position.
FIG. 10 is a partial isometric view of a toggle arm removed from the assembly.
FIG. 11 is a view taken along lines 11--11 of FIG. 7 with a cutout showing the retaining means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings and describing the preferred embodiment, the invention consists of a plurality of channel shaped attaching bases 20 having a length less than the inside height of a refrigerated trailer. The web of the base 20 further contains bores 22, best depicted in FIG. 7, used for attachment to the trailer wall with self-tapping screws, drive rivets or the like. A plurality of spring retaining clips 24, preferably two or more, are attached to the inner web of the base 20, as illustrated in FIGS. 7 and 11. This clip 24 is fabricated of a flexible material with a memory such as spring steel or stainless steel. The clip 24 is angle shaped with one end radiused and the flat portion indented to receive and retain a round member. This clip 24 is fastened to the base 20 with threaded fasteners, self-tapping devices, welding or the like with riveting being preferred utilizing at least a pair of rivets 26.
Each of the legs of the base 20 contain a series of aligned bores 28 to receive a swiveling attaching arm. These bores 28 are equidistant, except a closer spacing is utilized near the bottom for added strength at the maximum load dispersing area.
The base 20 may be fabricated of any material having the structural integrety to withstand shock loads coincident with trailer loading and over-the-road operation. Steel, structural plastic including fiberglass, or magnesium may be utilized with aluminum being preferred. This material may be extruded, however, forming from flat stock is preferable, as this allows the holes to be punched in the flat, which is a more economical method of production.
The bores 28 are aligned with a plurality of toggle arms 30 that are channel shaped with legs that are extended and radiused. Each of the four legs contain a hole 32 to match the above bores 28.
The toggle arm is best illustrated in FIG. 10 separated from the assembly for clarity, and shown extended in FIGS. 2 and 8 and collapsed in FIGS. 3 and 9. This arm 30 is wider at the end coupled to the base, however, the channel shape is maintained. The legs on the wide end are sized to slip inside the base 20 and rotate freely when attached together through the bore 28 and hole 32. This attachment is accomplished by a rivet 34 held in place with a push-on keeper 36, however, any suitable fastener may be used such as a cotter pin with a key or screws, nuts and washers. The extended legs of the toggle arm 30 allow rotation completely inside of the channel shaped base 20 with no interference by the web of the arm nesting unobstructively together.
The other end of the arm 30 is similarly attached to an extending support member 38. This member 38 is also in channel shape but is attached reversely with the web opposite that of the base 20. This member 38 is best depicted extended in FIGS. 2 and 8 and collapsed in FIGS. 3 and 9 with an end view of FIGS. 4 and 5.
The extending support member 38 is the same approximate length as the base 20 with a plurality of bores 40 in spaced relationship to those of the base 20. These bores 40 are located in each leg and mate with the holes 32 of the toggle arms 30. The extended legs of the arm 30 are positioned on the outside of the support member 38 with the bore 40 aligned with the hole 32 and secured with attaching means. This attachment is accomplished preferably with a bearing pin in the form of a rivet 42 extending through both sides of the arm 30 and member 38 being held in place with a push-on keeper 36 the same as used on the opposite end. This fastening arrangement may incorporate the use of dowels with cotter pins in each end or shoulder bolts and nuts or any other suitable method providing a continuity is maintained between the two sides of the arm 30 and member 38.
The rotatable attachment of both ends allows the arm 30 to swivel within the confines of the base 20 and member 38, moving the member 38 away from the base 20 in parallelogram fashion to the extended position and then rotate inwardly to the collapsed condition. This allows the toggle arm 30 to be completely retained within the base 20 and the member 38. This allows the entire assembly to collapse to perhaps one quarter of its extended depth.
The web of the toggle arm 30 embraces the legs of the support member 38 in its extended position holding the apparatus open or extended by the force of gravity. The arrangement of the toggle 30 in relationship to the base 20 and member 38 is over the center of gravity and when extended is positioned by the physical interference of the members. When rotated upwards, nesting of the two open channels takes place reducing the thickness of the device. When unrestrained, the channels separate and seek their angle of repose which is below the horizontal centerline. The extended apparatus has the strength to withstand a horizontal linear force such as inflicted by a shifting load of cargo or horizontal G-loads due to trailer deceleration or downhill operation.
A plurality of toggle arms 30 are utilized in the preferred embodiment with at least two required for operation. Six arms have proven optimum for test loadings of 26,400 lbs. (11,974 kilograms) or 0.4 G's at a theoretical load of 66,000 lbs. (29,937 kilograms). The limiting factor has been the bearing pin 42 which yielded at a load of 30,000 lbs. (13,608 kilograms) with five assemblies attached together.
The web of the extending support members 38 further contain a plurality of clearance holes 44 in spaced relationship with the openings 22 in the base 20. These holes 44 and openings 22 are juxtapositioned when the assembly is collapsed allowing fasteners and tools to be inserted into the holes 44 and secure the assembly to the trailer wall with the forementioned attachments.
When the assembly is collapsed, the shank of the bearing pin 42 is urgingly embraced by the spring retaining clip 24 and is held in place by friction. The radiused end of the clip 24 moves upwardly when forced by the pin 42 from its relaxed position and the indented surface, having a corresponding shape, securely holds the pin in place. When a force is applied in the opposite direction, the pin is released and the assembly is extended by gravity to its normal open position.
The bulkhead assemblies may be used individually, as shown in FIG. 6, in multiples of at least two, and as many as required to be smaller than the cargo outline and still accomplish the air flow duct utility. The preferred number is five, allowing two pallets to be loaded side-by-side and not block the air flow path.
A partition 44, shown in FIG. 1, is secured to the bulkhead assemblies in another embodiment. This partition 44 is narrower than the trailer interior allowing it to move radially with the toggle arms 30.
The bulkhead is normally fabricated of plywood but may be composition wood, thermoplastic, fiberglass or metal, or any suitable substance. The partition 44 is attached to the extended support members 38 by blind fasteners such as drive or blind rivets, self-tapping screws, insert nuts or the like.
The partition 44 is located above the floor line at least two thickness of the bulkhead, allowing unrestricted evaporator return air.
The top of the bulkhead is below the outlet of a refrigeration unit supply air opening, and in the case of a flush evaporator refrigeration unit it completely covers the return air opening. The depth of the bulkhead may vary, however, laboratory tests have indicated that using a 3.80 inch (96.52 millimeter) distance from the trailer wall to the interior of the partition 44 allows an air flow rate of 3300 cubic feet per minute (93.42 cubic meters per minute) to be achieved with a conventional refrigeration unit operating at high speed. This air flow rate is optimum for units in trailers 28 feet (8.46 meters) and above. The velocities through the bulkhead at this air flow rate are approximately 1544 feet per minute (470.6 meters per minute). When the bulkhead is collapsed the air flow rate is reduced to approximately 2475 cubic feet per minute (70.07 cubic meters per minute), which is adequate for unit operation in most normal load and ambient temperature conditions.
When the bulkhead is extended, the support members 38 do not touch the floor but transmit the load directly to the trailer wall through the toggle arms 30. This allows the load bearing surface of the front wall to evenly absorb the shock load of the bulkhead throughout the entire surface, rather than dividing the load horizontally to the wall and vertically to the floor.
Although the invention has been described in complete detail and pictorially shown in the accompanying drawings, it is not to be limited to such details since many changes and modifications may be in the invention without departing from the spirit and scope thereof hence it is described to cover any and all modifications and forms which may come within the language and scope of the appended claims.
|
A bulkhead formed of nesting channels connected together with toggle arms. The channels are attached to the forward wall of a refrigerated trailer and form a barrier to protect a refrigeration unit and provide an unrestricted air passage duct for return air. A channel shaped outboard extending support member swivels on toggle arms and due to its overcenter arrangement, remains extended vertically. When the outboard member is rotated upwardly, the channels and toggles nest together decreasing the depth of the apparatus. The collapsed position is maintained by several spring retaining clips that grasp a toggle arm connecting member.
In another embodiment the channels are connected together with a solid partition which is positioned above the floor and below the air discharge opening of a refrigeration unit.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of and is related to two co-pending and commonly-owned applications entitled “SURGICAL STAPLING INSTRUMENT INCORPORATING A MULTISTROKE FIRING MECHANISM HAVING A ROTARY TRANSMISSION”, Ser. No. 10/881,105, and “SURGICAL STAPLING INSTRUMENT INCORPORATING AN UNEVEN MULTISTROKE FIRING MECHANISM HAVING A ROTARY TRANSMISSION”, Ser. No. 10/881,091, both to Frederick E. Shelton IV, Michael Earl Setser, and Douglas B. Hoffman and filed on 30 Jun. 2004, the disclosure of both of which is hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates in general to surgical stapler instruments that are capable of applying lines of staples to tissue while cutting the tissue between those staple lines and, more particularly, to improvements relating to stapler instruments and improvements in processes for forming various components of such stapler instruments that accomplish firing with multiple strokes of a trigger.
BACKGROUND OF THE INVENTION
[0003] Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
[0004] Known surgical staplers include an end effector that simultaneously makes a longitudinal incision in tissue and applies lines of staples on opposing sides of the incision. The end effector includes a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
[0005] An example of a surgical stapler suitable for endoscopic applications is described in U.S. Pat. No. 5,465,895, which advantageously provides distinct closing and firing actions. Thereby, a clinician is able to close the jaw members upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler with a single firing stroke, thereby severing and stapling the tissue. The simultaneous severing and stapling avoids complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.
[0006] One specific advantage of being able to close upon tissue before firing is that the clinician is able to verify via an endoscope that a desired location for the cut has been achieved, including a sufficient amount of tissue has been captured between the opposing jaws. Otherwise, opposing jaws may be drawn too close together, especially pinching at their distal ends, and thus not effectively forming closed staples in the severed tissue. At the other extreme, an excessive amount of clamped tissue may cause binding and an incomplete firing.
[0007] Generally, a single closing stroke followed by a single firing stroke is a convenient and efficient way to perform severing and stapling. However, in some instances, it would be desirable for multiple firing strokes to be required. For example, surgeons are able to select, from a range of jaw sizes, a corresponding length of staple cartridge for the desired length of cut. Longer staple cartridges require a longer firing stroke. Thus, a hand-squeezed trigger to effect the firing is required to exert a larger force for these longer staple cartridges in order to sever more tissue and drive more staples as compared to a shorter staple cartridge. It would be desirable for the amount of force to be lower and comparable to shorter cartridges so as not to exceed the hand strength of some surgeons. In addition, some surgeons not familiar with the larger staple cartridges may become concerned that binding or other malfunction has occurred when an unexpectedly higher force is required.
[0008] One approach to lower the required force for a firing stroke is a ratcheting mechanism that allows a firing trigger to be stroked multiple times, as described in U.S. Pat. Nos. 5,762,256 and 6,330,965. However, it is believed that the conversion of the reciprocating motion of the firing trigger directly into a solid rack by a pawl constrains design options for a desired amount of firing motion during each firing stroke. In addition, these known surgical stapling instruments with multiple-stroke firing mechanisms do not have the advantages of a separate closure and firing action.
[0009] Consequently, a significant need exists for a surgical stapling instrument that uses multiple firing strokes to achieve a desired length of severing and stapling with a desired relationship of firing stroke travel to longitudinal firing motion produced for an end effector.
BRIEF SUMMARY OF THE INVENTION
[0010] The invention overcomes the above-noted and other deficiencies of the prior art by providing a surgical stapling and severing instrument having a rotary transmission that transfers a sequence of multiple firing strokes while preventing backup of a firing member. Thereby, an end effector of the instrument requiring increased firing forces and/or increased firing travel may be readily fired with a multiple stroke firing trigger.
[0011] In one aspect of the invention, a surgical instrument has an end effector that is responsive to a longitudinal firing motion to perform a surgical operation. A user causes movement in a firing actuator to create the firing motion that is selectively transferred by a firing mechanism. Specifically, a rotary transmission receives firing and return motion from a firing actuator that is cycled at the discretion of the operator. An input rotary member rotates in correspondence to the firing and return direction motions thereof. Those rotations that correspond to the firing direction are then selectively communicated by a one-way clutch to an output rotary member that engages an elongate firing member to transfer this intermittent firing motion to the end effector. Thereby, multiple firing strokes are achieved to reduce the required force required per individual stroke over a single stroke device. In addition, a gear reduction relationship may be selected by appropriate sizing of the input and output rotary members as well as any mechanical advantage given by the firing actuator to select the desired force exerted at the firing actuator and have it realized as longitudinal travel and force at the elongate firing member.
[0012] In another aspect of the invention, a surgical instrument has an end effector that severs and staples tissue. In particular, a staple applying assembly distal has an anvil having a staple forming surface moveable from an open position spaced away from a plurality of staples to a closed position adjacent to the plurality of staples. A staple applying mechanism has the rotary transmission that causes the application of at least a portion of the staples from the staple applying assembly. Thereby, a multiple stroke firing may be used to sever and staple tissue.
[0013] These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
[0015] FIG. 1 is a perspective view of a surgical stapling and severing instrument having an open end effector.
[0016] FIG. 2 is a left side elevation view in cross section along lines 2 - 2 of the open end effector of FIG. 1 .
[0017] FIG. 3 is a perspective view of the open end effector of FIG. 1 .
[0018] FIG. 4 is an exploded, perspective view of an implement portion of the surgical stapling and severing instrument of FIG. 1 .
[0019] FIG. 5 is an exploded, perspective view of a handle of the surgical stapling and severing instrument of FIG. 1 .
[0020] FIG. 6 is a left side view in elevation of the handle of the surgical stapling and severing instrument of FIG. 1 in an open condition with a left portion of a handle housing removed to expose a firing mechanism including a rotary transmission for multiple firing strokes.
[0021] FIG. 7 is a right side view in elevation of the handle of FIG. 6 with a right portion of the handle portion removed to expose a closure mechanism and anti-backup features.
[0022] FIG. 8 is a downward perspective view of the handle of FIG. 7 .
[0023] FIG. 9 is a side elevation view of the handle of FIG. 6 with the closure trigger closed and the firing trigger omitted to expose a firing drive wedge and cam lobes in a cam disk.
[0024] FIG. 10 is a downward perspective view of the firing drive wedge and cam lobes of FIG. 9 .
[0025] FIG. 11 is an aft perspective view of a rotary transmission firing mechanism of the handle of FIG. 1 .
[0026] FIG. 12 is a side elevation view of the handle of FIG. 6 in a closed and fired condition with a small idler gear of the rotary transmission firing mechanism omitted to expose an anti-backup pendulum contacting a solid rack.
[0027] FIG. 13 is perspective view of an alternative rotary transmission firing mechanism incorporating a rotary slip clutch for the surgical stapling and severing instrument of FIG. 1 with implement portions, left handle shell and closure mechanisms omitted.
[0028] FIG. 14 is a perspective exploded view of the slip clutch rotary transmission firing mechanism of FIG. 13 with implement portions, left handle shell and closure mechanisms omitted.
[0029] FIG. 15 is a right side elevation detail view of the slip clutch assembly of the rotary transmission firing mechanism of FIG. 13 with a left spur gear thereof shown in phantom, depicted as disengaged as a firing trigger is released.
[0030] FIG. 16 is a right side elevation detail view of the slip clutch assembly of the rotary transmission firing mechanism of FIG. 13 , depicted as engaged as the firing trigger is actuated.
[0031] FIG. 17 is a left side elevation view of the rotary transmission firing mechanism of FIG. 13 in an initial, unfired state with implement portions, left handle shell and closure mechanisms omitted.
[0032] FIG. 18 is a left side elevation view of the rotary transmission firing mechanism of FIG. 13 after a first firing stroke with implement portions, left handle shell and closure mechanisms omitted.
[0033] FIG. 19 is a left side elevation view of the rotary transmission firing mechanism of FIG. 13 after the firing trigger is released following the first firing stroke with implement portions, left handle shell and closure mechanisms omitted.
[0034] FIG. 20 is a left side elevation view of the rotary transmission firing mechanism of FIG. 13 after a second firing stroke with implement portions, left handle shell and closure mechanisms omitted.
DETAILED DESCRIPTION OF THE INVENTION
[0035] Turning to the Drawings, wherein like numerals denote like components throughout the several views, FIGS. 1-4 depict a surgical stapling and severing instrument 10 that is capable of practicing the unique benefits of the present invention. The surgical stapling and severing instrument 10 incorporates an end effector 12 having an anvil 14 pivotally attached to an elongate channel 16 , forming opposing jaws for clamping tissue to be severed and stapled. The end effector 12 is coupled by a shaft 18 to a handle 20 . An implement portion 22 , formed by the end effector 12 and shaft 18 , is advantageously sized for insertion through a trocar or small laparoscopic opening to perform an endoscopic surgical procedure while being controlled by a surgeon grasping the handle 20 . The handle 20 advantageously includes features that allow separate closure motion of the end effector 12 from firing, as well as enabling multiple firing strokes to effect firing (i.e., severing and stapling) of the end effector 12 while indicating the degree of firing to the surgeon.
[0036] To these ends, a closure tube 24 of the shaft 18 is coupled between a closure trigger 26 and the anvil 14 to cause closure of the end effector 12 . Within the closure tube 24 , a frame 28 is coupled between the elongate channel 16 and the handle 20 to longitudinally position and support the end effector 12 . A rotation knob 30 is coupled with the frame 28 , and both elements are rotatably coupled to the handle 20 with respect to a rotational movement about a longitudinal axis of the shaft 18 . Thus, the surgeon can rotate the end effector 12 by turning the rotation knob 30 . The closure tube 24 is also rotated by the rotation knob 30 but retains a degree of longitudinal movement relative thereto to cause the closure of the end effector 12 . Within the frame 28 , a firing rod 32 is positioned for longitudinal movement and coupled between the anvil 14 of the end effector 12 and a multiple-stroke firing trigger 34 . The closure trigger 26 is distal to a pistol grip 36 of the handle 20 with the firing trigger 34 distal to both the pistol grip 36 and closure trigger 26 .
[0037] In endoscopic operation, once the implement portion 22 is inserted into a patient to access a surgical site, a surgeon refers to an endoscopic or other diagnostic imaging device to position tissue between the anvil 14 and elongate channel 16 . Grasping the closure trigger 26 and pistol grip 36 , the surgeon may repeatably grasp and position the tissue. Once satisfied as to the location of the tissue relative to the end effector 12 and the amount of tissue therein, the surgeon depresses the closure trigger 26 fully toward the pistol grip 36 , clamping the tissue in the end effector 12 and locking the closure trigger 26 in this clamped (closed) position. If not satisfied with this position, the surgeon may release the closure trigger 26 by depressing a release button 38 ( FIG. 4 ), whose operation is described more fully below, and thereafter repeat the procedure to clamp tissue.
[0038] If clamping is correct, the surgeon may proceed with firing the surgical stapling and severing instrument 10 . Specifically, the surgeon grasps the firing trigger 34 and pistol grip 36 , depressing the firing trigger 34 a predetermined number of times. The number of firing strokes necessary is ergonomically determined based on a maximum hand size, maximum amount of force to be imparted to the instrument during each firing stroke, and the longitudinal distance and force needed to be transferred through the firing rod 32 to the end effector 12 during firing. As will be appreciated in the discussion below, individual surgeons may choose to cycle the firing trigger 34 a different angular range of motion, and thus increase or decrease the number of firing strokes.
[0039] In FIG. 1 , after firing the surgical stapling and severing instrument 10 , a closure release lever 40 is activated to retract the firing mechanism. Depressing the closure release lever 40 disengages a rotary transmission firing mechanism 42 within the handle 20 , enabling a spring 172 to retract the firing rod 32 from the end effector 12 .
[0040] Implement Portion Including an E-Beam End Effector.
[0041] The advantages of a handle 20 capable of providing multiple-stroke firing motion has application to a number of instruments, with one such end effector 12 being depicted in FIGS. 1-4 . The anvil 14 of end effector 12 responds to the closure motion from the handle 20 that is transferred longitudinally and distally by the closure tube 24 . The elongate channel 16 slidingly engages the translating and closing anvil 14 to form opposing jaws, and the frame 28 fixedly engages the stationary channel 16 to form a rigid attachment to the handle 20 . The closure tube 24 engages the anvil 14 distal to the pin in slot connection between the anvil 14 and elongate channel 16 . Thus, a distal movement of the closure tube 24 relative to the frame 28 effects closure and a proximal movement relative to the frame 28 effects opening of the end effector 12 .
[0042] With particular reference to FIG. 4 , the implement portion 22 also includes components that respond to a firing motion from the handle 20 , specifically of the firing rod 32 (not shown in FIG. 4 ) that couples a longitudinal motion between the firing mechanism 42 in the handle 20 and the implement portion 22 . In particular, the firing rod 32 (shown disassembled in FIG. 5 ) rotatably engages a firing trough member 46 slidably located within a longitudinal recess 48 in frame 28 . Firing trough member 46 moves longitudinally within frame 28 in direct response to longitudinal motion of firing rod 32 . A longitudinal slot 50 in the closure tube 24 operably couples with the rotation knob 30 (not shown), the longitudinal slot 50 further allowing the rotation knob 30 to engage the frame 28 at a small longitudinal slot 52 therein to effect rotation. A tab is located in front of slot 50 on the closure tube 24 and the tab is bent down into slot 52 in the frame 28 to couple the closure tube 24 to the frame 28 . The length of the longitudinal slot 50 in the closure tube 24 is sufficiently long as to allow relative longitudinal motion with the rotation knob 30 to accomplish closure motions respectively.
[0043] The distal end of the frame trough member 46 is attached to a proximal end of a firing bar 56 that moves with the frame 28 , to distally project an E-beam 60 into the end effector 12 . The end effector 12 includes a staple cartridge 62 that is actuated by the E-beam 60 that causes staples to be drive up from staple apertures 64 of the cartridge 62 into contact with staple forming grooves 68 of the anvil 14 , creating formed “B” shaped staples. With particular reference to FIG. 3 , the staple cartridge body 86 further includes a proximally open, vertical slot 70 for passage of a vertically oriented cutting surface provided along a distal end of E-beam 60 to cut tissue while being stapled.
[0044] The illustrative end effector 12 is described in greater detail in five co-pending and commonly-owned U.S. patent applications, the disclosure of each being hereby incorporated by reference in their entirety: (1) “SURGICAL STAPLING INSTRUMENT HAVING A SINGLE LOCKOUT MECHANISM FOR PREVENTION OF FIRING”, Ser. No. 10/441,424, to Frederick E. Shelton, Mike Setser, Bruce Weisenburgh, filed 20 Jun. 2003; (2) “SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS”, Ser. No. 10/441,632, to Frederick E. Shelton, Mike Setser, Brian J. Hemmelgarn, filed 20 Jun. 2003; (3) “SURGICAL STAPLING INSTRUMENT HAVING A SPENT CARTRIDGE LOCKOUT”, Ser. No. 10/441,565, to Frederick E. Shelton, Mike Setser, Bruce Weisenburgh, filed 20 Jun. 2003; (4) “SURGICAL STAPLING INSTRUMENT HAVING A FIRING LOCKOUT FOR AN UNCLOSED ANVIL”, Ser. No. 10/441,580, to Frederick E. Shelton, Mike Setser, Bruce Weisenburgh, filed 20 Jun. 2003; and (5) “SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM”, Ser. No. 10/443,617, to Frederick E. Shelton, Mike Setser, Bruce Weisenburgh, filed 20 Jun. 2003.
[0045] It should be appreciated that although a nonarticulating shaft 18 is illustrated herein, applications of the present invention may include instruments capable of articulation, such as described in five co-pending and commonly owned U.S. patent applications, the disclosure of each being hereby incorporated by reference in their entirety: (1) “SURGICAL INSTRUMENT INCORPORATING AN ARTICULATION MECHANISM HAVING ROTATION ABOUT THE LONGITUDINAL AXIS”, Ser. No. 10/615,973, to Frederick E. Shelton, Brian J. Hemmelgarn, Jeff Swayze, Kenneth S. Wales, filed 9 Jul. 2003; (2) “SURGICAL STAPLING INSTRUMENT INCORPORATING AN ARTICULATION JOINT FOR A FIRING BAR TRACK”, Ser. No. 10/615,962, to Brian J. Hemmelgarn, filed 9 Jul. 2003; (3) “A SURGICAL INSTRUMENT WITH A LATERAL-MOVING ARTICULATION CONTROL”, Ser. No. 10/615,972, to Jeff Swayze, filed 9 Jul. 2003; (4) “SURGICAL STAPLING INSTRUMENT INCORPORATING A TAPERED FIRING BAR FOR INCREASED FLEXIBILITY AROUND THE ARTICULATION JOINT”, Ser. No. 10/615,974, to Frederick E. Shelton, Mike Setser, Bruce Weisenburgh, filed 9 Jul. 2003; and (5) “SURGICAL STAPLING INSTRUMENT HAVING ARTICULATION JOINT SUPPORT PLATES FOR SUPPORTING A FIRING BAR”, Ser. No. 10/615,971, to Jeff Swayze, Joseph Charles Hueil, filed 9 Jul. 2003.
[0046] Multi-Stroke Firing Handle.
[0047] In FIGS. 5-8 , the handle 20 responds to actuation of the closure trigger 26 and firing trigger 34 to generate respectively the closure and firing motions to the implement portion 22 . With regard to the closure motion, the closure trigger 26 includes an upper portion 76 that includes three lateral apertures, a forwardly positioned pin hole 78 , a lower, aft pivot hole 80 , and a center cutout 82 . Three rods are laterally oriented between and engaged to right and left half shells 84 , 86 of a handle housing 88 (with the right half shell 84 shown in FIGS. 5-6 and the left half shell 86 shown in FIG. 7 ). In particular, an aft rod 90 passes through the aft pivot hole 84 of the upper portion 80 of the closure trigger 26 , and thus the closure trigger 26 pivots about the aft rod 90 . A front rod 92 , which is distally positioned to the aft rod 90 , and a top rod 94 , which is above the front rod 92 , pass through the center cutout 86 , which is shaped to constrain movement of the closure trigger 26 by contacting the front and top rods 92 , 94 at each extreme of trigger travel. Thus, the center cutout 86 includes a vertical portion, whose bottom surface contacts the front rod 92 when the closure trigger 26 is forward (distal), and includes an upper, proximally sloped portion, whose top and forward surfaces contact the top rod 94 respectively when the closure trigger 26 is at its forward, relaxed position and its proximal, actuated position.
[0048] A closure yoke 96 , which engages the closure tube 24 , is longitudinally slidingly received within the handle housing 92 and is engaged at its distal end to a proximal end of the closure tube 24 , thus transferring longitudinal closure motion to the closure tube 24 and hence to the anvil 14 for closing the end effector 12 . This engagement allows rotation of the closure tube 24 while the closure yoke 96 does not rotate. Above this engagement, a lateral pin hole 100 is coupled to a closure link 102 by a front pin 104 , with the other end of the closure link 102 coupled to the pin hole 82 of the closure trigger 26 via an aft pin 106 .
[0049] A triangular spacer 120 includes holes 122 , 124 , 126 to receive the rods 90 , 92 , 94 respectively and is sandwiched between a cam disk 130 and the upper portion 80 of the closure trigger 26 . Cam disk 130 rotates about the front rod 92 and includes a semi-circular slot 132 that receives the aft and top rods 90 , 94 . A central hole 134 receives front rod 92 . To the left of the cam disk 130 , a rod hole 136 at an upper end 138 of the firing trigger 34 receives the top rod 94 . Firing trigger 34 rotatably mounts onto rod 94 to sandwich cam disk 130 between the triangular spacer 120 and firing trigger 34 . A distally opened recess 140 in the firing trigger 34 below the rod hole 136 is registered to receive the front rod 92 , allowing the firing trigger 34 to be drawn distally during firing. Actuation of the closure trigger 26 swings the cam link 102 downward into contact with drive wedge pin 184 extending inwardly from firing trigger 34 causing the firing trigger 34 to be partially drawn distally and staging the firing trigger 34 for grasping.
[0050] With particular reference to FIGS. 5, 9 , and 10 , the cam disk 130 presents a series of cam lobes 142 - 144 ( FIG. 9 ) about the forward portion (when in its unfired state as depicted), specifically along its left side, that are respectively engaged by the firing trigger 34 to impart a top-to-front (counter-clockwise as viewed from the left) rotation to the cam disk 130 . This rotation is transferred through a gear train 150 ( FIGS. 5 and 11 ) of the rotary transmission firing mechanism 42 , beginning with a gear portion 152 about a lower portion of the right side of the cam disk 120 that engages a small idler gear 154 , which thus rotates top to the rear (clockwise) at an increased rate relative to the cam disk 130 . A large idler gear 156 is connected by an idler axle 158 to the small idler gear 154 and thus rotates in the same direction and rate. A second small gear 160 is enmeshed to the larger idler gear 156 , and is thus rotated top to the front (counter-clockwise as viewed from the left) at a greater rate. A fine-toothed large gear 162 is connected by a second axle 164 to the second small gear 160 and thus rotates in the same direction and rate as the second small gear 160 . The gear train 150 thus amplifies the motion of the cam disk 120 by including a double gear reduction feature to provide additional longitudinal firing motion. The fine-toothed large gear 162 engages a gear segment 168 on an underside of a solid rack 170 whose distal end engages the proximal end of the firing rod 32 . The rack 170 has its distal portion longitudinally slidingly received within the closure yoke 96 and its proximal portion longitudinally slidingly received between right and left shell halves 84 , 86 of the handle housing 88 .
[0051] The selective engagement of the firing trigger 34 to the cam lobes 142 - 144 provides further longitudinal travel by enabling multiple firing strokes of the firing trigger 34 . To prepare the gear train 150 for firing, the cam disk 130 is urged clockwise toward its unfired position by a gear train retraction spring 172 attached to a leftward projecting integral pin 174 formed within an annular recess 176 at a lower proximal edge of the cam disk 120 ( FIGS. 9-10 ). The gear train retraction spring 172 has its other end attached to a pin 178 integral to the handle housing 88 . Activation of the firing trigger 34 rotates cam disk 130 counter-clockwise to elongate the retraction spring 172 . Continued actuation of the firing trigger 34 wraps the elongated retraction spring 172 about the outer diameter of the cam disk 130 as it rotates and into the annular recess 176 (not shown).
[0052] With particular reference to FIGS. 5, 9 , 11 , below and distal to the upper end 128 of the firing trigger 34 is a drive wedge pin hole 180 and a proximal pin hole 190 . Drive wedge pin 184 and pin 196 extend inwardly from holes 180 and 190 (respectively) in firing trigger 34 . Drive wedge 182 and a standoff finger 186 are pivotally mounted on drive wedge pin 184 and operably connected by a mousetrap-style spring 188 . An opposing tension spring 194 between drive wedge 182 and pin 196 urge the drive wedge 182 , standoff finger 186 , and spring 188 clockwise ( FIG. 10 ). When firing trigger 34 is actuated ( FIG. 9 ), standoff finger 186 is brought into contact with a center, uncammed circumferential surface of the cam disk 120 , rotating the standoff finger 186 , spring 188 and drive wedge 182 counterclockwise. The counterclockwise motion of standoff finger 186 biases drive wedge 182 into firing engagement with the cam lobes 142 - 144 ( FIG. 9 ).
[0053] With particular reference to FIG. 12 , when the drive wedge 182 is drawn away from one of the cam lobes 142 - 144 between firing strokes, the cam disk 130 would tend to rotate top to the rear by the action of the gear train retraction spring 172 but for the action of an anti-backup lever 200 . Lateral pins 202 , 204 of the anti-backup pendulum 200 engage respective right and left shell halves 84 , 86 of the handle housing 88 . Above the pins 202 , 204 , an anti-backup tension spring 206 is attached to an integral pin 208 of the right half shell 88 distal to the anti-backup pendulum 200 . With particular reference to FIG. 5 , a lower foot 210 of the anti-backup pendulum 200 makes frictional contact with an upper surface 212 of the solid rack 170 . When the lower foot 210 of the anti-backup pendulum 200 is drawn proximally by a retracting solid rack 170 , the anti-backup lever 20 approaches a perpendicular engagement to the solid rack 170 that increases the frictional force, locking the solid rack 170 , which is sufficient to overcome the backdriving force provided by the gear train retraction spring 172 . When the solid rack 170 is driven distally by the firing trigger 34 , the lower foot 210 is pushed distally, reducing the friction and allowing firing. Excessive forward movement of the lower foot 210 is prevented by the idler axle 158 and by the urging from the anti-backup tension spring 206 .
[0054] In FIG. 12 , the release button 38 is pivoted upward about its aft pivot pins 220 , 222 , raising its distal arm 224 above a proximally directed arm 226 of the anti-backup pendulum 200 allowing distal movement of the lower foot 210 for locking the rack 170 between firing strokes. A clamp locking lever 230 rocks about its lateral pivot pins 232 , 234 to effect this raising of the release button 38 . In particular, a proximally and upwardly projecting arm 236 of the clamp locking lever 230 slidingly abuts an undersurface of the distal arm 224 of the release button 38 . A distally projecting locking arm 238 of the clamp locking lever 230 locks the closure yoke 96 in its clamped condition. In particular, a tab 240 extending down between the proximally and upwardly projecting arm 236 and the distally projecting locking arm 238 is urged proximally by a tension spring 242 that is also attached to the right half shell 84 of the handle housing 88 at a pin 244 . With reference to FIGS. 6-7 , the distally projecting locking arm 238 rests upon a step 246 presented on a top, proximal portion of the closure yoke 96 , allowing the closure yoke 96 to be distally moved to transfer the closure motion. A clamp locking notch 248 , which is a distally and upwardly open recess of the step 246 , receives the distally projecting locking arm 238 when the closure yoke 96 reaches its distal actuated position ( FIG. 8, 9 ). Thus, the surgeon may release the closure trigger 26 with the end effector 12 remaining clamped.
[0055] With reference to FIGS. 5-8 , 12 , in addition to the afore-described anti-backup feature and closure clamping feature, a firing lockout feature is provided by a firing lockout lever 250 . With the surgical stapling and severing instrument 10 in its initial open and unfired state, the firing lockout lever 250 responds to the closure yoke 96 being retracted by blocking distal, firing movement of the solid rack 170 , as shown particularly in FIGS. 7 and 8 . The firing lockout lever 250 includes a distally extending arm 252 having a distally ramped upper surface 254 that is aligned with a right edge 256 along the proximal portion of the solid rack 170 . A recessed right edge 258 along the remaining distal portion of the solid rack 170 allows the distally ramped upper surface 254 of the firing lockout lever 250 to rotate upward, pivoting about its proximal lateral pins 260 , 262 urged by a tension spring 264 connected to a vertical tab 266 that is perpendicularly and proximally attached to the distally extending arm 252 . The other end of the tension spring 264 is connected to an integral pin 268 formed in the right half shell 84 of the handle housing 88 aft of the vertical tab 266 .
[0056] As shown in FIG. 8 , the distally ramped surface 254 blocks distal movement of the solid rack 170 by being wedged upward by a step 270 formed across the proximal end of the closure yoke 96 , open proximally and upwardly to receive the downwardly pivoting distally extending arm 252 of the firing lockout lever 250 . With the closure yoke 96 moved distally to close the end effector 12 as shown in FIG. 12 , the right edge 256 of the solid rack 170 is allowed to pass over the distally ramped surface 254 that responds thereto by moving the distally extending arm 252 downward to engage a lower step 272 formed in the closure yoke 96 proximal to the higher and more distal step 270 . The engagement of the firing lockout lever 250 to the lower step 272 has a benefit of preventing retraction (proximal movement) of the closure yoke 96 until the solid rack 170 is fully retracted. Thus, initiating retraction of the firing mechanism 42 advantageously occurs prior to unclamping of the end effector 12 , which may otherwise cause binding in the firing mechanism 42 . Moreover, enough frictional contact may exist between the lower step 272 and the firing lockout lever 250 to advantageously require a two-step procedure to return the surgical stapling and severing instrument 10 to its open and retracted condition. In particular, once the firing mechanism 42 has been retracted by depressing the release button 38 , a slight squeeze on the closure trigger 26 would tend to allow the firing lockout lever 250 to raise to its firing lockout position. Thereafter, the release of the closure trigger 26 may proceed with the firing lockout lever 250 aligned for engagement of the higher step 270 when the closure yoke 96 is fully retracted and thus the end effector 12 opened.
[0057] In use, the surgeon positions the end effector 12 and shaft 18 through the cannula of a trocar to a surgical site, and positions the anvil 14 and elongate channel 16 as opposing jaws to grasp tissue to be stapled and severed. Once satisfied with the position of end effector 12 , the closure trigger 26 is fully depressed toward the pistol grip 36 of the handle 20 , causing a closure link 102 to advance a closure yoke 96 and thus a closure tube 24 to close the end effector 12 . The distally moved closure yoke 96 presents a clamp locking notch 248 that receives a clamp locking lever 230 , clamping the end effector 12 . Stroking the firing trigger 34 multiple times effects firing of the firing rod 32 by sequentially engaging a drive wedge 182 that is coupled to the firing trigger 34 to cam lobes 142 - 144 on the cam disk 130 . This ratcheting rotation is transferred through the rotary transmission firing mechanism 150 to distally advance the solid rack 170 . With the closure yoke 96 advanced, the rack 170 is able to depress a firing lockout lever 250 out of the way. Between firing strokes, the anti-backup pendulum 100 is drawn into a perpendicular locking contact with the rack 170 , opposing a retraction force imparted by the gear train retraction spring 172 connected to the cam gear 130 . Once full firing travel is achieved, depressing the closure release lever 40 first disengages the anti-backup pendulum 100 , allowing the solid rack 170 to retract and secondly disengages the clamp locking lever 230 from the closure yoke 96 to remove one impediment from opening the end effector 12 . The surgeon squeezes the closure yoke 26 to allow the firing lockout lever 250 to release from the closure yoke 96 and releases the closure trigger 26 , allowing the closure yoke 96 to proximally move to where it holds up the firing lockout lever 250 to lock out the sold rock 170 from firing. Thereafter, the implement portion 22 of the surgical stapling and severing instrument 10 may be removed such as for replacing the staple cartridge 62 in preparation for another operation.
[0058] Slip Clutch Rotary Transmission.
[0059] In FIGS. 13-14 , an alternative rotary transmission firing mechanism 300 for a surgical stapling and severing instrument 310 incorporates a rotary slip clutch assembly 312 for one way engagement of movement of a firing actuator (trigger) 314 into a solid rack 316 and firing rod 318 . It will be appreciated that other components of the closure mechanism and implement portion of the surgical stapling and severing instrument 310 are omitted from FIGS. 13-14 but operate similarly to that described above.
[0060] The firing trigger 314 at its upper portion 320 includes a lateral pivot hole 322 that engages a pin 324 projecting leftward from a right handle shell 326 . A hollow cylindrical spacer 328 and a female pin receptacle registered in a left handle shell (not shown in FIGS. 13-14 ) to engage pin 324 pivotally positions the firing trigger 314 in a vertical plane to the left and proximate to the solid rack 316 .
[0061] An arcuate gear aperture 330 is laterally defined in the firing trigger 314 below the pin hole 322 and is registered below a bottom toothed surface 332 of the solid rack 316 . The slip clutch assembly 312 includes a left spur gear 342 that is in gear engagement to a curved gear segment 344 along a bottom portion of the arcuate gear aperture 330 . The slip clutch assembly 312 also includes a right spur gear 346 that is in gear engagement to the bottom toothed surface 332 of the solid rack 316 . A slip clutch shaft 348 projects from a receptacle 350 ( FIG. 14 ) in the right handle shell 326 to be engaged within a hole in the left handle shell (not shown) with both spur gears 342 , 346 freely rotating on the slip clutch shaft 348 . The relative sizes of the left and right spur gears 342 , 346 may be advantageously selected for a desired gear ratio between movement of firing trigger 314 and the amount of longitudinal translation of the solid rack 316 .
[0062] Attached for rotational movement with the right face of the left spur gear 342 is an inner cam wheel 360 having three ramped outer recesses 362 , 364 , 366 . This inner cam wheel 360 is received inside of a central hole 372 in the right spur gear 346 . Between the central hole 372 and respective ramped outer recesses 362 - 366 are rollers 380 , 382 , 384 . As show in FIGS. 15-16 , the assembly acts as a roller-ramp clutch (a.k.a., over running clutch, one way clutch, and free wheeling clutch). In FIG. 15 , as the firing trigger 314 is brought distally (counter clockwise (CCW) as viewed from the right), the left spur gear 342 is maintained in position within the housing by slip clutch shaft 348 and thus left spur gear 342 rotates top to the rear (CCW). The inner cam wheel 360 rotates with the left spur gear 342 . The rollers 380 - 384 thus tend to remain within a roomier portion (i.e., clockwise (CW)) of their respective ramped outer recesses and thus do not transfer this motion to the right spur gear 346 , and thus to the solid rack 316 .
[0063] With reference to FIGS. 13-14 , the alternative rotary transmission firing mechanism 300 incorporates an anti-backup mechanism 400 that operates distal to the slip clutch mechanism 312 . In particular, a pendulum 402 has a pivot hole 403 that rotates about a left portion of a pendulum axle 404 , which is received in an axle hole 406 of the right handle shell 326 and the corresponding axle hole in the left handle shell (not shown). A foot 408 of the pendulum 402 rotates about the pendulum axle 404 either distally and out of engagement to a top surface 409 or proximally to a more vertical alignment into frictional engagement with the top surface 409 . The pendulum 402 has an upper portion 410 opposite to the foot 408 about the pivot hole 404 that is resiliently urged forward by an anti-backup spring 412 that is engaged to a proximal pin 414 that passes through the upper portion 410 and a distal pin 416 that is received between a pin receptacle 418 in the right handle shell 326 and a corresponding pin receptacle in the left handle shell (not shown). Thus, the pendulum foot 408 is urged into locking the solid rack 316 . The anti-backup spring 412 is overcome by the forward motion of the solid rack 316 during firing.
[0064] Applications consistent with the present invention may employ other anti-backup mechanisms, such as described in co-pending and commonly-owned patent application Ser. No. 10/673,929, titled “SURGICAL STAPLING INSTRUMENT WITH MULTISTROKE FIRING INCORPORATING AN ANTI-BACKUP MECHANISM”, filed on Sep. 29, 2003, the disclosure of which is hereby incorporated by reference in its entirety.
[0065] Retraction of the alternative rotary transmission firing mechanism 300 is achieved by simultaneously disengaging the anti-backup mechanism 400 and the slip clutch assembly 312 , thus allowing the solid rack 316 to be urged proximally by a retraction spring 500 , which is connected between a proximal spring hole 502 in the solid rack 316 and a proximal-most pin 504 projecting from the right handle shell 326 . Manual disengagement of the anti-backup mechanism 400 is achieved by an operator depressing a retraction button 510 ( FIG. 14, 17 ), which pivots a forward arm 512 downward about a lower aft pivot attachment 514 of the retraction button 510 . The forward arm 512 in turn draws down an aft arm 520 of a rocker member 522 about its center pivot attachment 524 , causing its distal and upward projecting arm 526 to rotate up and aft, thus drawing aft a retraction link 528 that is attached to the proximal pin 414 that passes through the upper portion 410 of the pendulum 402 , causing thereby the pendulum foot 408 to rotate distally out of engagement to the upper surface 409 of the solid rack 316 . It should be appreciated thus that when the anti-backup mechanism 400 is in its locked position, the opposite movement of these components causes the retraction button 510 to be lifted.
[0066] Generally, the proximal movement of the solid rack 316 , and thus the right spur gear 346 of the slip clutch assembly 312 , should be sufficient to cause the rollers 380 - 384 to disengage, even if the firing trigger 314 is in a partially actuated position wherein the left spur gear 342 is still engaged to the curved gear segment 344 along the bottom portion of the arcuate gear aperture 330 therein. It should be appreciated that some applications may further include retraction features that force the rollers 380 - 384 out of engagement with the right spur gear 346 to ensure disengagement (e.g., three cam pins that are forced into the ramped recesses 362 - 366 ).
[0067] In use, the alternative rotary transmission firing mechanism 300 achieves multiple stroke firing as depicted in a sequence as depicted in FIGS. 17-20 . In FIG. 17 , the solid rack 316 is fully retracted proximally and the firing trigger 314 has been drawn back slightly to a ready position wherein the slip clutch assembly 312 is about to engage. In FIG. 18 , the firing trigger 314 has been drawn proximally after a first stroke. The slip clutch assembly 312 has rotated a corresponding amount driving the solid rack 316 distally, extending the retraction spring 500 . As the firing trigger 314 is released and allowed to rotate distally under the action of a spring (not shown), the slip clutch assembly 312 disengages and the anti-backup mechanism 400 locks the solid rack 316 by the aft movement of the pendulum foot 408 . In FIG. 19 , the firing trigger 314 is beginning a second stroke causing the slip clutch assembly 312 to again engage, transmitting the firing motion of the firing trigger 314 into a distal movement of the solid rack 316 from where it was left in FIG. 18 . This firing motion causes the anti-backup mechanism 400 to disengage as the pendulum foot 408 rotates distally against the anti-backup spring 412 .
[0068] While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
[0069] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping a handle of an instrument. Thus, the end effector 12 is distal with respect to the more proximal handle 20 . It will be further appreciated that for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.
[0070] The present invention is being discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as “endoscopic”, should not be construed to limit the present invention to a surgical stapling and severing instrument for use only in conjunction with an endoscopic tube (i.e., trocar). On the contrary, it is believed that the present invention may find use in any procedure where access is limited to a small incision, including but not limited to laparoscopic procedures, as well as open procedures.
[0071] For instance, while a surgical stapling and severing instrument 10 is described herein that advantageously has separate and distinct closing and firing actuations, it should be appreciated that applications consistent with the present invention may include a handle that converts a single user actuation into a firing motion that closes and fires the instrument.
[0072] In addition, while a manually actuated handle is illustrated, a motorized or otherwise powered handle may benefit from incorporating a linked rack as described herein, allowing reduction of the size of the handle or other benefits. For instance, while partially stowing the linked rack into the pistol grip is convenient, it should be appreciated that the pivot connection between links allows for stowing the link parallel to the straight portion defined by the shaft and the barrel of the handle.
[0073] It should further be appreciated that the rack 170 may be advantageously formed of links that allow a portion proximal to the firing mechanism 42 to be curved into the handle, allowing for a more compact design. Such a linked rack is described in greater detail in co-owned “SURGICAL STAPLING INSTRUMENT INCORPORATING A FIRING MECHANISM HAVING A LINKED RACK TRANSMISSION”, Ser. No. 10/673,930, to Jeffrey S. Swayze, Frederick E. Shelton IV, filed 29 Sep. 2003, which is incorporated herein by reference in its entirety.
|
A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector.
| 0
|
CLAIM OF PRIORITY
The present invention claims priority from Japanese application JP 2004-169749 filed on Jun. 8, 2004, the content of which is hereby incorporated by reference to this application.
BACKGROUND OF THE INVENTION
The present invention concerns a mass spectrometer.
In the following description, mass or m/z means a mass to charge ratio, and a mass range or a m/z range means a range for the mass to charge ratio.
In the linear ion trap mass spectrometer used for proteome analysis, etc., high sensitivity, high mass accuracy, MS n analysis, etc. are required. Mass spectrometry using the linear ion trap in the prior art is to be described.
In the prior art described, for instance, in U.S. Pat. No. 5,420,425 (Patent Document 1), after accumulation of ions introduced into an linear ion trap, ion selection or ion dissociation is conducted as required. Then, ions are ejected mass selectively from the linear ion trap in the radial direction by scanning a trapping RF voltage. It is described that the mass resolution is improved by superposing a supplemental AC voltage on quadrupole rods in this case. This enables mass analysis at high sensitivity.
In the prior art described in U.S. Pat. No. 6,177,668 (Patent Document 2), after accumulation of ions introduced into a linear ion trap, ion selection or ion dissociation is conducted as required. Then, ions are ejected mass selectively from the linear ion trap in the axial direction by applying a supplemental AC voltage on the quadrupole rods. Mass analysis at high sensitivity is possible by scanning the frequency of the supplemental AC voltage or the amplitude of the trapping RF voltage.
In the prior art described in U.S. Pat. No. 5,783,824 (Patent Document 3), after accumulation of ions introduced into a linear ion trap, ion selection or ion dissociation is conducted as required. Inserted lenses are interposed between quadrupole rods and a harmonization potential is formed on the linear ion trap axis by a DC bias between the inserted lenses and the quadrupole rod. Then, by applying a supplemental AC voltage between the inserted lenses, ions are ejected mass selectively from the linear trap in the axial direction. Mass analysis at high sensitivity is possible by scanning the DC bias or the frequency of the supplemental AC voltage.
Then, a method of measuring neutral loss scan or precursor ion scan in the prior art is to be described.
In a quadrupole time-of-flight mass spectrometer (QqTOF) or a triple quadrupole mass spectrometer (TripleQ), it has been proposed a method of conducting precursor ion scanning. For example, in the prior art described in ‘Organic Mass spectrometry, vol. 28, pp 1135 to 1143, 1993’ (Non-Patent Document 1), only the ion species having a predetermined modified portion can be screened from a sample where a great amount of chemical noises are present, by the precursor ion scan of scanning the mass (m/z) range of the quadrupole mass filter in the pre-stage (Q 1 ) while fixing the mass (m/z) range for the ion detection in the succeeding stage, or neutral loss scan for scanning the mass (m/z) range of the quadrupole mass filter in the pre-stage while fixing the difference of mass between the detection mass (m/z) range in the succeeding stage and the mass (m/z) range in the quadrupole mass filter at the pre-stage. The method is utilized, for example, for confirming the presence of phosphorylated peptide ion species from a specimen where various peptides are mixed.
In order to enhance an extremely low ion utilization efficiency (herein after referred to as Duty Cycle) of the precursor ion scan or neutral loss scan in the prior art, a method of mass selectively ejecting ions from the linear ion trap has been proposed. For instance, U.S. Pat. No. 6,504,148 (Patent Document 4), a method of accumulating ions in a linear ion trap disposed in the pre-stage of a collision chamber, then, introducing only the ions within a specified mass (m/z) range (exactly, at specified mass to charge ratio) from the linear ion trap into the collision reaction chamber to dissociate ions and then detecting the ions by a TOF or quadrupole mass filter thereby improving the Duty Cycle in the neutral loss scan or the precursor scan.
On the other hand, a method of decreasing the space charge of the ion trap is proposed. For example, in the method of the prior art described in US No. 2003/0071206 A1 (Patent Document 5), a quadrupole mass filter is located at the pre-stage of an ion trap and ions other than those required are previously excluded therein. This can introduce only the specified ions as the target for measurement to the ion trap portion, to moderate the space charge of the ion trap.
Further, a method of decreasing the space charge is proposed. For example, in the method of the prior art described in U.S. Pat. No. 5,179,278 (Patent Document 6), a linear ion trap is located to the pre-stage of the 3d quadrupole ion trap and the ions other than those required are excluded in the linear ion trap based on the information such as previously acquired mass spectrum by the application of a supplemental AC voltage. This can introduce only the specified ions as a target for measurement to the 3d quadrupole ion trap portion to moderate the space charge.
SUMMARY OF THE INVENTION
Also in any of the prior art describes in the Patent Documents 1 to 3, the linear ion trap has a larger ion accumulation capacity (by the number of about 10 6 ) than the 3d quadrupole ion trap and can attain relatively high Duty Cycle (=ion accumulation time/(total measuring time) upon MS 1 measurement). The Duty Cycle is about 50% at the current typical ion accumulation time of 100 ms and the scan time of 100 ms.
However, even the linear ion trap results in a problem of causing the space charge due to increase of the ion introduction rate and the ion accumulation time. That is, the ion introduction rate will be improved more in the future by the improvement for the ion source or the ion transport region and, correspondingly, this will give rise to a problem of requiring shortening of the ion accumulation time capable of permitting the space charge. Assuming that the ion introduction rate will increase by ten times, the ion accumulation time not causing the space charge will decrease from 100 ms to 10 ms, resulting in a problem that the Duty Cycle lowers from 50% to 9%. Further, in a case where the ion introduction amount increases by 100 times, this results in a problem that the ion accumulation time is decreased from 100 ms to 1 ms and the Duty Cycle lowers from 50% to 1% or less. Further, a high resolution mode, with the mass resolution being improved than usual, is present also at present. In this case, it is necessary to lower the scan speed further and shorten the accumulation time of the ion trap further and, accordingly, the problem that the Duty Cycle lowers to 1% or less has already been present.
Further, in the prior art described in the Non-Patent Document 1 involves a subject that the Duty Cycle is remarkably low upon precursor ion scan and neutral loss scan. For example, in a case of scanning at 1000 amu with the transmission mass (m/z) window of 1 amu for the quadrupole mass filter in the pre-stage, since the ions other than the transmission mass (m/z) window are not utilized, the duty ratio is: 1 amu/1000 amu=0.1%.
Further, in the prior art described in the Patent Document 4, after trapping the ions of a wide m/z (m/z range in the first linear ion trap, ions of predetermined mass are successively introduced into a collision chamber in the subsequent stage. It is to be described below that the same problem as that in the prior art described in Paten Documents 1 to 3 becomes more conspicuous in this case.
It takes about 10 ms for the ion transmission time inside the collision cell. In order to prevent cross-talk, a low scan speed at about 10 ms/amu is generally used for the linear ion trap at the pre-stage. Accordingly, it needs 10 s for the scan at 1000 amu. Since the typical ion introduction rate into the trap is about 10 7 /sec, ions by the number of about 10 8 are introduced into the linear ion trap during 10 s. When such a great amount of ions are present in the trap, the ions cause the space charge and the mass resolution lowers to about several tens.
To avoid space charge effect from degrading the mass resolution ejected from the linear ion trap, it is necessary to restrict the total amount of ions inside the ion trap below about 10 6 , and only the ions for 100 ms can be accumulated in the ion trap. As a result, the Duty Cycle is about 100 ms/(100 ms+10 s)=1%. In addition, since the typical axial ejection efficiency from the linear ion trap is about 20%, it can be said that the effect of the prior art described in the Patent Document 4 is further smaller. In view of the foregoings, it is suggested that an effective reduction of the space charge is necessary for attaining higher Duty Cycle.
Further, the prior arts described in the Patent Documents 5 and 6 each proposes a method of suppressing the space charge of the ion trap in the subsequent stage. However, in each of them, the m/z transmitting the filter in the pre-stage is fixed in a predetermined mass (m/z) range and the space charge inside the ion trap is decreased by selecting only the ions corresponding thereto in the pre-stage. On the contrary for the method of scanning for wide mass (m/z) range, the existent method described in the Patent Documents 5 and 6 involves a problems that the mass (m/z) range that can be measured is restricted.
The present invention intends to provide a mass spectrometer using a linear ion trap capable of efficiently suppressing the space charge and capable of attaining scanning for a wide mass (m/z) range at a high Duty Cycle and capable of conducting analysis at high sensitivity.
In order to attain the forgoing object, the mass spectrometer according to the present invention has features to be described below.
The constituent A for the mass spectrometer according to the invention comprises an ion source for ionizing a specimen to generate ions, an ion transport portion for transporting the ions, a linear ion trap portion for accumulating the transported ions by a potential formed axially, and a control portion of ejecting the ions within a second m/z range different from a first m/z range from the linear ion trap portion substantially at the same timing as the timing of accumulating the ions within the first m/z range to the linear ion trap portion, in which the control portion conducts control of ejecting the ions mass selectively from the linear ion trap portion by any of voltage application of (1) applying a supplemental AC voltage between at least a pair of linear ion trap rods constituting the linear ion trap portion, (2) applying a supplemental AC voltage to an end lens constituting the linear ion trap portion, and (3) applying a supplemental AC voltage between inserted lenses, the inserted lenses constituting the linear ion trap portion.
The constituent B for the mass spectrometer according to the invention comprises an ion source for ionizing a specimen to generate ions, an ion transport portion for transporting the ions, a linear ion trap portion for accumulating the transported ions by a potential formed axially, a reaction chamber for reacting the ions ejected from the linear ion trap portion with a gas, light or electron, etc. introduced from the outside to the inside and conducting reactions such as decomposing reaction, dissociating reaction and charge reduction reaction from multi-charged ions to lower charged ions, a mass spectrometric portion for mass spectrometry of reaction products formed in the reaction chamber and ejected through the reaction chamber, and a control portion of ejecting the ions within a second m/z range different from a first m/z range from the linear ion trap portion substantially at the same timing as the timing of accumulating the ions within the first m/z range to the linear ion trap portion, in which the control portion conducts control of ejecting the ions mass selectively from the linear ion trap portion by any of voltage application of (1) applying a supplemental AC voltage between at least a pair of linear ion trap rods constituting the linear ion trap portion, (2) applying a supplemental AC voltage to an end lens constituting the linear ion trap portion, and (3) applying a supplemental AC voltage between inserted lenses, the inserted lenses constituting the linear ion trap portion.
In the constitution A or the constitution B, the ion transport portion comprises a mass selection means for selecting the ions within the first m/z range in which (1) the linear ion trap portion ejects the ions mass selectively within the first m/z range within the second m/z range, (2) the linear ion trap portion changes the second m/z range in accordance with the change of the first ion m/z range, (3) the transmission mass (m/z) window within the first m/z range transmitting the ion transport portion by the mass selection means is set (controlled) by the previously measured mass spectrum (mass distribution) of the ions introduced to the linear ion trap portion, (4) the mass selection means is a quadrupole mass filter, and (5) the mass selection means is constituted with a linear ion trap and mass selectively ejects the ions from the ion transport portion, etc.
The constitution C of the mass spectrometer according to the invention comprises an ion source for ionizing a specimen to generate ions, a mass selection means for selecting the ions within a first m/z range, a linear ion trap portion of accumulating the selected ions by the potential formed axially and ejecting the ions mass selectively within the second m/z range different from the first m/z range from the linear ion trap portion substantially at the same timing as the timing for accumulating the ions, and a control portion for conducting control for accumulation of the ions and control for ejecting the ions mass selectively from the linear ion trap portion, in which the control portion conducts control for ejecting the ions mass selectively from the linear ion trap portion by any of voltage application of (1) applying a supplemental AC voltage between at least a pair of linear ion trap rods constituting the linear ion trap portion, (2) applying the supplemental AC voltage to the end lens constituting the linear ion trap portion, (3) applying a supplemental AC voltage between inserted lenses, the inserted lenses constituting the linear ion trap portion and, further, the mass selection means is constituted with a quadrupole mass filter portion having quadrupole rods.
According to the invention, it is possible to provide a mass spectrometer using a linear ion trap capable of efficiently suppressing the space charge and capable of attaining high Duty Cycle and remarkably improving the sensitivity in a case of scanning a wide range of m/z.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a constitutional example of a linear ion trap mass spectrometer of Example 1 according to the present invention;
FIG. 2 is a view for explaining an example of a measuring sequence upon positive ion measurement in an apparatus of the prior art;
FIG. 3 is a view for explaining an example of a measuring sequence in Example 1 according to the invention;
FIG. 4 is a view showing an example of change with time for the m/z range of in-taken ions and for the m/z range of ejected ions in Example 1 according to the invention;
FIGS. 5( a ) and 5 ( b ) are views showing an example of relation between the total ion amount in the ion trap and the time in Example 1 of the invention;
FIG. 6 is a view showing an example of the dependence of the Duty Cycle on k in Example 1 and in the prior art;
FIG. 7 is a view showing a constitutional example of a linear ion trap mass spectrometer as Example 2 of the invention;
FIG. 8 is a view showing a constitutional example of a linear ion trap mass spectrometer as Example 3 of the invention;
FIG. 9 is a view showing a constitutional example of a linear ion trap mass spectrometer as Example 4 of the invention;
FIG. 10 is a view showing a constitutional example of a linear ion trap mass spectrometer as Example 5 of the invention; and
FIG. 11 is a view showing an example of a flow chart for measurement in Example 6 of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE 1
FIG. 1 is a view showing a constitutional example of a linear ion trap mass spectrometer of Example 1 according to the present invention. FIG. 1 shows, in the lower part, a potential for each of portions of a quadrupole mass filter and a linear ion trap near the center axis for z axis.
In FIG. 1 , as an ion source 1 for ionizing a specimen to generate ions, one of ion sources of an electro spray ion source, an atmospheric pressure chemical ion source, an atmospheric pressure photo-ion source, or an atmospheric pressure matrix assisted laser desorption ion source is used. Ions generated from the specimen in the ion source 1 are passed through a not illustrated differential pumping region and an orifice 2 and introduced to a quadrupole mass filter comprising quadrupole rods 3 .
An RF voltage at 1 MHz of about several tens V to several kV at the reversed phase is applied alternately to each of the quadrupole rods 3 , and a DC voltage of several tens V to several kV is applied between them. By the application of the voltages, ions within the specified m/z range can pass through the quadrupole mass filter. In a general case of using the quadrupole mass filter alone for mass separation, the transmission m/z window is set to about 0.5 amu to 3 amu.
In Example 1, a broad transmission m/z window of several tens amu to several hundreds amu is set to the quadrupole mass filter. Accordingly, the gas pressure in the region where the quadrupole mass filter is disposed can be set to a wide vacuum range of 3×10 −2 Torr to 10 −6 Torr. Further, it has been generally known that by conducting ion cooling in the region, energy of the ions is made uniform to improve the trapping efficiency in the linear ion trap at the subsequent stage. For improving the trapping efficiency in the linear ion trap at the subsequent stage, it is most appropriate to set the vacuum degree to about 10 −4 to 3×10 −2 Torr.
The ions within the specified m/z range selected by the quadrupole mass filter are passed through a gate lens 4 , a linear ion trap inlet lens 5 and introduced into the quadrupole electric fields of the linear ion trap formed by the linear ion trap rods 6 . A buffer gas is introduced by an appropriate method into the region where the linear ion trap rods 6 are disposed to maintain the vacuum degree to a predetermined value for the range. As the buffer gas, inert He, Ar, N 2 etc. are used. In a case of using He as the buffer gas, the vacuum degree is kept at about 10 −2 Torr to 10 −4 Torr and, in a case of using Ar, N 2 as the buffer gas, the vacuum degree is kept at about 3×10 −3 Torr to 3×10 −5 Torr.
The ions are cooled by collision with the buffer gas in the region where the linear ion trap is disposed and converged radially on a center axis of the quadrupole electric fields formed by the linear ion trap rods 6 (center axis of linear ion trap). A DC bias of about 5V to 30 V relative to the DC bias on the linear ion trap electrodes 6 is applied to the linear ion trap inlet lens 5 and the linear ion trap end lens 7 .
The ions are trapped stably inside the linear ion trap by the DC potential on the center axis and by the quadrupole electric field potential formed by the linear ion trap rods 6 . By applying the supplemental AC voltage between a pair of opposed linear ion trap rods 6 , the ion orbit is enlarged in the radial direction and ions are ejected from the linear ion trap. The ejected ions are detected by a detector 9 and recorded in the memory of a controller (control portion) 12 .
The controller (control portion) 12 controls the voltage to be applied to each of the electrodes of the gate lens 4 , linear ion trap inlet lens 5 , linear ion trap end lens 7 , ion stop lens 8 (lens controlling the introduction of ions to the detector 9 ), and control the power supply (power supply 10 for the quadrupole rod generating a voltage to be applied to the quadrupole rod 3 and a linear ion trap power supply 11 generating a voltage to be applied to the linear ion trap rod 6 ), and controls the operation sequence of the mass spectrometer.
In the manner similar to the constitution as described above, a supplemental quadrupole rod (not illustrated) may sometimes be inserted between the liner trap inlet lens 5 and linear ion trap end lens 7 , and the linear ion trap rods 6 to eliminate so called ‘fringing field’ effects. In this case, a DC bias is applied between the supplemental quadrupole rod and the linear ion trap rods to trap the ions.
In Example 1, the operation sequence of the mass spectrometer is controlled by the method to be described below. For making the difference clear with respect to the prior art, description is at first made to the operation sequence of the apparatus in the prior art (for example upon positive ion measurement).
FIG. 2 is a diagram for explaining the example of the measuring sequence upon positive ion measurement in the prior art apparatus.
In the prior art apparatus, ions are trapped for several ms to several hundreds ms in accordance with the ion strength. During ion accumulation, a negative DC bias of 0V to several tens V relative to the off set potential of the quadrupole rod 3 is applied to the gate lens 4 , and a positive DC bias of several V to several tens V relative to the off set potential on the quadrupole rod 3 is applied to the ion stop lens 8 . This enables to enter and accumulate the ions to the inside of the ion trap while not introducing the ions to the detector 9 .
On the other hand, during mass selective ejection of ions (that is, during scanning) a positive DC bias of several V to several tens V relative to the off set potential on the quadrupole rod 3 is applied to the gate lens 4 and, further, a trapping RF voltage is applied to the linear ion trap lens 6 such that the amplitude value increases with time to conduct scanning under the application of the supplemental DC voltage to the linear ion trap lens 6 , and a negative DC bias of several V to several tens V relative to the end lens 7 is applied to the ion stop lens 8 .
As described above, in the prior art apparatus, ion trap (accumulation) and mass selective ejection (scanning) of ions were controlled by the voltage applied to the gate lens 4 .
FIG. 3 is a diagram for explaining an example of the measurement sequence during positive ion measurement in Example 1 of the invention.
In the measurement sequence in Example 1, there is no distinction in view of time for the trap (accumulation) and scanning of ions. Also during ion scanning, the gate lens 4 is set to a low voltage (negative DC bias of 0 V to several tens V relative to the off set potential to the quadrupole rod 3 ), to conduct ion trapping (accumulation).
By applying a DC voltage that increases with time (pre-Q filter DC voltage) and an RF voltage changing such that the amplitude value of the trapping RF voltage increase with time (pre-Q filter RF voltage) to the quadrupole rod 3 , only the ions with m/z window of several tens amu to several hundreds amu (the range being defined as the first m/z range (M 1 )) are entered to the linear ion trap. At the same time with the application of the DC voltage and the RF voltage to the quadrupole rod 3 , the trapping RF voltage is applied such that the amplitude value thereof increases with time to the linear ion trap rod 6 under the application of a supplemental AC voltage to the linear ion trap rod 6 to conduct scanning, while a positive DC voltage of several V to several tens V relative to the off set potential on the quadrupole rod 3 is applied to the ion stop lens 8 such that ions are introduced to the detector 9 thereby inhibiting ions from ejecting in the axial direction.
As described above, appropriate RF voltage and supplemental AC voltage are supplied from the power source 11 for linear ion trap to the linear ion trap rod 6 and ions within m/z range of about 0.2 amu to 3 amu (the range being defined as the second m/z range (M 2 )) are ejected as to be described later. The supply voltage is to be described specifically. As explained previously, the quadrupole rod power supply 10 and the linear power supply 11 are controlled by the controller 12 .
Voltage; VQ(t)sin □Qt+UQ(t), and −VQ(t)cos □Qt−UQ(t) (DC bias component is not shown in the formulae for the voltage) are supplied on every other quadrupole rods 3 shown in FIG. 1 from the quadrupole rod power supply 10 . Further, the voltages: VL(t)cos □L t+VS(t)cos ωSt, and −VL(t)cos □Lt, VL(t)cos □Lt, VS(t)cos ω St, and −VL(t)cos □Lt (DC bias component is not shown in the formula for the voltage) is supplied to each of the linear ion trap rods 6 from the linear ion trap power supply 11 . In the formulae, t represents the variant of time, and VQ, UQ, □Q, VL, □L VS, and ωS represent quadrupole RF voltage amplitude, quadrupole DC voltage, quadrupole RF angular frequency, trap RF voltage amplitude, trap RF angular frequency, supplemental AC voltage amplitude, and supplemental AC angular frequency, respectively.
FIG. 4 is a graph showing an example of change with time for the first m/z range (M 1 ) (m/z range for accumulated ion) and the second m/z range (M 2 ) (ejected ion m/z range). In FIG. 4 , the ordinate indicates m/z (exactly, mass to charge ratio) and the abscissa indicates the measuring period. In the graph, arrows in the lateral direction represent ion accumulation time relative to the m/z of m 1 (herein after means, exactly, mass to charge ratio m 1 /e) and m 2 (herein after means, exactly, mass to charge ratio m 2 /e). The region of the longitudinal arrow indicates the first m/z range (M 1 (t)) and blank circle shows the second m/z range (M 2 (t)) at time t.
As shown in FIG. 3 , by applying the pre-Q filter DC voltage and the pre-Q filter RF voltage to the quadrupole rods 3 and applying the supplemental AC voltage and the trapping RF voltage to the linear ion trap rods 6 , only the ions within the fist m/z range (M 1 ) of about several tens amu to 300 amu are entered to the linear ion trap, while the ions within the second m/z range (M 2 ) of about 0.2 amu to 3 amu are scanned and ejected from the linear ion trap.
As shown in FIG. 4 , the first and the second m/z ranges M 1 (t) and M 2 (t) change with time t. Further, the ion accumulation period is set to each of different timings in accordance with m/z m (for example m 1 , m 2 ) as shown by hatched line portion in FIG. 4 . This can effectively suppress the space charge to improve the Duty Cycle as will be explained below.
In Example 1, different two effects that can not be obtained in the prior art can be attained for suppressing the space charge. For the sake of simplicity, it is assumed here a model in which the distribution for the m/z to ion strength is uniform, the first m/z range (transmission m/z range), ΔL, is constant and the scanning speed is constant.
FIGS. 5( a ) and 5 ( b ) are graphs showing an example of a relation between the total ion amount C in the ion trap and the time in Example 1 of the invention. The abscissa in FIGS. 5( a ) and 5 ( b ) indicates the measuring period based on the total measuring period assumed being as 1.
In the prior art shown in FIG. 5( b ), ions accumulated during scanning decreases monotonously along with the time (measuring period). Since the limit for the space charge is determined by the initial ion amount, a state with a margin for the space charge continues in the latter half of the detection time as a result.
On the other hand, in Example 1 as shown in FIG. 5( a ), since the total ion amount in the trap is constant substantially over the total measuring period, it can be seen that more ions can be accumulated inside the trap. While it is assume in this model that the limit for the space charge is identical relative to the measuring time or the detection time and the m/z of ions ejected mass selectively, the ion amount permitted for the trap is increased actually as the m/z of the ions ejected mass selectively increases because of increase of the pseudo-potential along with increase in the amplitude of the RF voltage for the linear ion trap. Accordingly, the effect calculated for the model is further increased.
Then, it is considered for the effect of mass selection by the pre-stage quadrupole mass filter. It is assumed that the amount of ion that can be accumulated as C, the ion stream as I 0 , the total scanning time as T 0 , the first selection range as ΔL, the total ion range as L 0 , and k=T 0 I 0 /C. In the prior art, since the Duty Cycle is maximized when the ions are accumulated up to the limit amount for the space charge, it is represented by (equation 1) and (equation 2). k is an index for the space charge.
Duty
Cycle
=
(
Trapping
Time
)
/
(
Total
Time
)
=
(
C
/
I
0
)
/
{
(
C
/
I
0
)
+
T
0
}
(
equation
1
)
Duty
Cycle
≦
1
/
(
1
+
k
)
(
equation
2
)
The index k takes a larger value as the scanning time is longer, the ion introduction amount to the ion trap is larger, or the amount of ion that can be accumulated is smaller. In the existent usual scan mode, T 0 =100 ms, I 0 =10 7 m/sec, and C=10 6 and k=1 approximately, in which Duty Cycle is ensured by about 50% thus causing no significant problem. However, for obtaining a higher resolution than usual, it is necessary to suppress the amount of trapped ions and scanning at low speed is required. Accordingly, T 0 =1 s and C=10 5 , approximately, and k=100, so that the ion Duty Cycle lowers to about 1%. It is expected that the ion source, the differential pumping region, etc. will be improved in the future, and k in the usual measuring mode also tends to increase.
Then, the Duty Cycle in Example 1 is to be derived. The total ion amount Q inside the linear ion trap in Example 1 is represented by (equation 3).
Q =( T 0 I 0 /2)(Δ L/L ) (equation 3)
For defining the charge amount Q to less than the ion amount C that can be accumulated, the condition of (equation 4) is necessary, and the Duty Cycle in Example 1 is represented by (equation 5). By substituting (equation 4) into (equation 5), (equation 6) is derived as the Duty Cycle of Example 1.
(
Δ
L
/
L
)
≦
(
2
/
k
)
1
/
2
(
equation
4
)
Duty
Cycle
=
(
Δ
L
/
L
)
T
0
/
{
(
Δ
L
/
L
)
T
0
+
T
0
}
=
(
Δ
L
/
L
)
/
{
1
+
(
Δ
L
/
L
)
}
(
equation
5
)
Duty
Cycle
≦
1
/
{
1
+
(
k
/
2
)
1
/
2
}
(
equation
6
)
FIG. 6 is a graph showing an example of dependence of Duty Cycle on k in the prior art and in Example 1. In FIG. 6 , the Duty Cycle in each of the prior art and Example 1 is determined according to (equation 2) and (equation 6), respectively.
In view of FIG. 6 , while the Duty Cycle is 1% in the prior art at k=100, the Duty Cycle of about 12% is obtained in Example 1. It is apparent that Example 1 can provide a remarkable effect of improving the sensitively as k increases compared with the prior art.
EXAMPLE 2
FIG. 7 is a view showing a constitutional example of a linear ion trap mass spectrometer in Example 2 according to the invention. FIG. 7 shows, in the lower part, the potential for each of portions near the center axis of z axis of the quadrupole mass filter and the linear ion trap. Example 2 is different in that ions are mass selectively ejected in the axial direction with respect to example 1. Accordingly, the voltage on the ion stop lens 8 is set lower than the potential on the linear ion trap end lens.
As a buffer gas, inert He, Ar, N 2 , etc. are used and the pressure inside the linear ion trap is kept about at 10 −2 Torr to 10 −4 Torr for He, and about at 3×10 −3 Torr to 3×10 −5 Torr for Ar, and N 2 . Ions are cooled by collision with the buffer gas and converged on the center axis of the linear ion trap.
A DC bias at about 3V to 5V relative to the DC bias on the linear ion trap rod 6 is applied to the linear ion trap inlet lens 5 and the linear ion trap end lens 7 . Ions are trapped stably inside the linear ion trap by the potential gradient on the center axis for the linear ion trap and the radial potential gradient formed by the linear ion trap quadrupole electric field.
Example 2 has a feature that the DC bias voltage on the linear ion trap rod 6 can be applied only to a lower level than that in Example 1 in view of the characteristics of ion ejection. In this case, if the ion energy incident to the linear ion trap has an extension, it may be a possibility that the ions are not trapped but reach as noises to the detector 9 . In Example 2, energy conversion in the pre-stage quadrupole mass filter is important, and it is desirable that the pressure in the range where the quadrupole mass filter is disposed is kept at 10 −3 Torr to 3×10 −2 Torr.
A supplemental AC voltage is applied to the linear ion trap rod 6 or the linear ion trap end lens 7 . The resonated ions are mass selectively ejected in the direction of the center axis of the linear ion trap by the fringing field formed by the linear ion trap end lens 7 . The ejected ions are detected by the detector 9 and recorded in the controller 12 .
Also in Example 2, substantially identical control with that in the measuring sequence shown in FIG. 3 is conducted. As a result, the first m/z range and the second m/z range are set as shown in FIG. 4 . Also in Example 2, an outstandingly higher Duty Cycle can be obtained than in the prior art with the same reason as explained for Example 1.
EXAMPLE 3
FIG. 8 is a view showing a constitutional example of a linear ion trap mass spectrometer in Example 3 according to the invention. FIG. 8 shows, in the lower part, the potential for each of portions near the center axis of z axis of the quadrupole mass filter and the linear ion trap. An inserted lens 16 is inserted and a DC bias is applied to the linear ion trap rod 15 , whereby a harmonic potential can be formed on the axis.
Example 3 has the constitution in which linear ion trap rods 15 are disposed instead of the linear ion trap rods 6 of Example 2 shown in FIG. 7 and the inserted lens 16 is interposed between the linear ion trap rods 15 , and a linear ion trap power source 13 for supplying voltage to the linear ion trap rods 15 and a inserted lens power supply 14 for supplying voltage to the inserted lens 16 are disposed. The constitution of introducing the buffer gas into the region where the linear ion trap rods 15 are disposed and the pressure condition inside the linear ion trap are identical with those in Example 2.
The inserted lenses 16 are disposed such that lenses of different length are inserted along the axis in the linear ion trap rods.
By applying a DC bias of several V to several tens V relative to the linear ion trap electrodes 15 on the inserted lens 16 , a harmonic potential is formed in the direction of the center axis of the linear ion trap. Details for the shape of the lens are described in the prior art of the Patent Document 3 described previously. Ions resonated by applying the supplemental AC voltage are accelerated in the direction of the center axis of the linear ion trap and ejected mass selectively. Since the resonance frequency of the ions is in inverse proportion to the square root of the mass (m/z) of the ions, only the specified ions can be ejected. The ejected ions are detected by the detector 9 and recorded in the controller 12 .
In Example 3, operation for each of the portions of the apparatus is controlled by the method substantially identical with that for the measuring sequence shown FIG. 3 . As a result, it is possible to control such that the first m/z range and the second m/z range are set as shown in FIG. 4 . Also in Example 3, an outstandingly higher Duty Cycle than the prior art can be obtained by the same reasons as explained for Example 1.
EXAMPLE 4
FIG. 9 is a view showing a constitutional example of a linear ion trap mass spectrometer of Example 4 according to the invention. FIG. 9 shows an example of using a triple quadrupole mass spectrometer. FIG. 9 shows, in the lower part, a potential for each of the portions near the center axis of z axis of the quadrupole mass filter, the linear ion trap and the quadrupole rods 17 .
The constitution shown in FIG. 9 is substantially identical with the constitution of Example 2 shown in FIG. 7 till the ions formed by the ion source 1 are introduced from the quadrupole mass filter to the linear ion trap. In the constitution shown in FIG. 9 , the constitution in which the ions formed by the ion source 1 are introduced from the quadrupole mass filter to the linear ion trap may be identical with the constitution of Example 3 shown in FIG. 8 .
Ions mass selectively ejected in the direction from the linear ion trap to the direction of the center axis of the linear ion trap are introduced into a collision chamber 23 where quadrupole rods 17 are disposed, undergo ion dissociation, etc. and are then introduced into the electric fields formed by the quadrupole rods 18 .
The collision chamber 23 comprises an ion stop lens 8 for the collision chamber inlet lens on the inlet thereof and a collision chamber end lends 24 on the inlet side thereof. A quadrupole rod power source 25 for supplying a voltage to the quadrupole rods 17 , a voltage applied to a collision chamber end lens 24 , and a quadrupole rod power source 26 for supplying a voltage to the quadrupole rods 18 are controlled by a controller 12 .
Usually, the collision chamber 23 is filled with an inert gas at about 1 mTorr to 100 mTorr introduced from a not illustrated gas introduction system, and a predetermined reaction can also be taken place by adding a reactive gas or the like to the inert gas. It takes from several ms to several tens ms of passing time for passing the ions through the collision chamber 23 . A slow scanning speed at several ms/amu to several tens ms/amu is used for preventing cross-talk of ions ejected mass selectively from the linear ion trap. For example, when scanning by 1000 amu at 10 ms/amu, T 0 =10 s. Since I 0 =10 7 and C=10 6 , k=100.
In the prior art disclosed in the Patent Document 4 described previously, the value of k described in Example 1 increases and the Duty Cycle only of 1% or less can be obtained. On the contrary, 12% Duty Cycle can be obtained in Example 4 like in Example 1 described previously. Example 4 is extremely suitable for use in the case where the scanning time is long. Ions dissociated in the collision chamber 23 are converged on the center axis of the quadrupole rods 17 and then introduced to the quadrupole mass filter comprising the quadrupole rods 18 (act as the quadrupole mass spectrometer). In the quadrupole mass filter, precursor scan and neutral loss scan can be conducted by passing the ions of specified m/z. Further, although not illustrated in the drawing, a linear ion trap, a quadrupole ion trap, or the like may also be disposed instead of the quadrupole rod 18 that act as a quadrupole mass filter and the same effects as described in Example 1 can also be provided.
EXAMPLE 5
FIG. 10 is a view showing a constitutional example of a linear ion trap mass spectrometer of Example 5 according to the invention. FIG. 10 shows an example of using a time-of-flight mass spectrometer (comprising a pusher 19 , a reflectron 20 , and a detector (MCP) 21 ) instead of the quadrupole rods 18 that act as the quadrupole mass filter and the detector 9 . FIG. 10 shows, in a lower part, a potential for each of the portions near the center axis of z axis of the quadrupole mass filter, the linear ion trap and the quadrupole rods 17 .
The constitution shown in FIG. 10 is substantially identical with the constitution of Example 2 shown in FIG. 7 till the ions formed by the ion source 1 are introduced from the quadrupole mass filter to the linear ion trap. In the constitution shown in FIG. 10 , the constitution in which the ions formed by the ion source 1 are introduced from the quadrupole mass filter to the linear ion trap may be identical with the constitution of Example 3 shown in FIG. 8 .
Ions ejected from the linear ion trap in the direction of the center axis of the linear ion trap are introduced to a collision chamber 23 where quadrupole rods 17 are disposed and undergo ion dissociation, etc. Usually, the collision chamber 23 is filled with an inert gas at about 1 mTorr to 100 mTorr and predetermined reaction can also be taken place by adding a reactive gas or the like to the inert gas. It takes from several ms to several tens ms of passing time for passing the ions through the collision chamber 23 . A slow scanning speed at several ms/amu to several tens ms/amu is used for preventing cross-talk of ions ejected mass selectively from the linear ion trap. For example, when scanning by 1000 amu at 10 ms/amu, T 0 =10 s. Since I 0 =10 7 and C=10 6 , k=100.
In the prior art disclosed in the Patent Document 4 described previously, the value of k described in Example 1 increases to 100 or more and the Duty Cycle only of 1% or less can be obtained. On the contrary, 12% Duty Cycle can be obtained in Example 5 like in Example 1 described previously.
Example 5 is extremely suitable for use in the case where the scanning time is long. Ions dissociated in the collision chamber 23 are converged on the center axis of the quadrupole rods 17 and then introduced to the time-of-flight mass spectrometer.
The ions are accelerated in a pusher 19 controlled by a pusher power source 26 in the direction perpendicular to the center axis of the electric fields formed by the quadrupole rods 17 , reflected at a reflectron 20 , then detected by a detector 21 comprising MCP, etc. and then the data are sent to a controller 12 and stored in a memory. Although not particularly illustrated in the drawing, a type with no reflectron 20 in FIG. 10 , or a multi-reflection type reflectron, etc. can also be used, where the effect as described for Example 1 can also be provided.
Further, although not illustrated, the effects described for Example 1 can also be provided in a case of disposing a Fourier transformation type ion cyclotron mass spectrometer (FT-ICRMS) instead of the TOF portion in FIG. 10 .
EXAMPLE 6
FIG. 11 is a view showing an example of a flow chart for the measurement in Example 6 of the invention.
For the ions introduced to the linear ion trap, while it has been assumed that the distribution of the m/z to ion strength (M(5) to I(t)) is a uniform distribution in Example 1 to Example 5, they are actually not uniform. Then, in Example 6, pre-scanning (preliminary measurement) is conducted prior to the measurement in Example 1 to Example 5 (usual measurement) and mass spectrum was measured to actually acquire the distribution for the m/z to ion strength (M(t) to I(t)) distribution (that is, mass spectral profile) as shown in the diagramon the left of FIG. 11 . High scanning speed may be used for the pre-scanning since not so high resolution and sensitivity are required.
The m/z window ΔL for the first m/z range of the ions introduced to the linear ion trap is changed by using the mass spectra profile acquired from the result of the pre-scanning, according to the m/z (that is, scanning time t) based on the data for the ion signal amount relative to the m/z (that is, scanning time t). That is, as shown in the diagram on the right of FIG. 11 , the m/z window ΔL(t) is determined setting it narrower for t where the value of the m/z to ion strength (M(t) to I(t)) is larger and, on the other hand, the m/z window ΔL(t) is determined setting it broader for t where the value of the m/z to ion strength (M(t) to I(t)) is smaller.
The total ion amount inside the linear ion trap can be kept substantially constant by the determination for the m/z window ΔL(t) Further, since the total ion amount permitting the space charge differs somewhat also depending on the RF voltage or the resonance frequency, it is possible for feedback control of the information to the m/z window ΔL(t) to use the permissible total charge amount C as a function of the RF voltage. It is also possible to determine the mass spectra profile based on previously measured data and determine the m/z range ΔL(t) with no particular use of the pre-scanning in the same manner as described above.
While the quadrupole mass filter is disposed to the pre-stage of the linear ion trap in Example 1 to Example 5 described above, the same effects can also be obtained by disposing a linear ion trap capable of mass selectively ejecting ions instead of the quadrupole mass filter disposed in the pre-stage. Further, it may also adopt a method of inhibiting introduction of ions to the linear ion trap by the control for the application of the supplemental AC voltage inside the linear ion trap, etc. without disposing the quadrupole mass filter or the linear ion trap in the pre-stage. While the method is advantageous in view of the cost but involves a demerit that the setting for the parameter is complicated.
In Example 2 to Example 5 described above, while a collision chamber to which the gas is introduced is used, it will be apparent that a constitution of irradiating light to conduct optical dissociation or a constitution of irradiating electron beam to conduct electron dissociation may also be adopted instead of the gas.
As has been described above specifically, the mass spectrometer according to the present invention can efficiently suppress the space charge and scan the wide m/z range at a high Duty Cycle thereby capable of providing a mass spectrometer using a linear ion trap capable of analysis at high sensitivity.
|
A mass spectrometer includes: an ion source for ionizing a specimen to generate ions, an ion transport portion for transporting the ions, a linear ion trap portion for accumulating the transported ions by a potential formed axially, and a control portion of ejecting the ions within a second m/z range different from a first m/z range, from the linear ion trap portion, and substantially at the same timing as the timing of accumulating the ions within the first m/z range from the transport portion into the linear ion trap portion. The ion transportation portion having a mass selection means for selecting the ions in the first m/z range.
| 7
|
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to downhole telemetry and, in particular to, utilizing the subsea template of a platform to carry an electrical current for communicating electromagnetic signals carrying information between surface equipment and downhole equipment.
BACKGROUND OF THE INVENTION
Without limiting the scope of the invention, its background is described in connection with communication between surface equipment and downhole devices during hydrocarbon production, as an example. It should be noted that the principles of the present invention are applicable not only during production, but throughout the life of a wellbore including, but not limited to, during drilling, logging, testing and completing the wellbore.
Heretofore, in this field, a variety of communication and transmission techniques have been attempted to provide real time communication between surface equipment and downhole devices. The utilization of real time data transmission provides substantial benefits during the production of hydrocarbons from a field. For example, monitoring of downhole conditions allows for an immediate response to potential well problems including production of water or sand.
One technique used to telemeter downhole data to the surface uses the generation and propagation of electromagnetic waves. These waves are produced by inducing an axial current into, for example, the production casing. This current produces the electromagnetic waves that include an electric field and a magnetic field, which are formed at right angles to each other. The axial current impressed on the casing is modulated with data causing the electric and magnetic fields to expand and collapse thereby allowing the data to propagate and be intercepted by a receiving system. The receiving system is typically connected to the ground or sea floor where the electromagnetic data is picked up and recorded.
As with any communication system, the intensity of the electromagnetic waves is directly related to the distance of transmission. As a result, the greater the distance of transmission, the greater the loss of power and hence the weaker the received signal at the surface. Additionally, downhole electromagnetic telemetry systems must transmit the electromagnetic waves through the earth's strata. In free air, the loss is fairly constant and predictable. When transmitting through the earth's strata, however, the amount of signal received is dependent upon the skin depth (δ) of the media through which the electromagnetic waves travel. Skin depth is defined as the distance at which the power from a downhole signal will attenuate by a factor of 8.69 db (approximately 7 times decrease from the initial power input), and is primarily dependent upon the frequency (f) of the transmission and the conductivity (σ) of the media through which the electromagnetic waves are propagating. For example, at a frequency of 10 hz, and a conductance of 1 mho/meter (1 ohm-meter), the skin depth would be 159 meters (522 feet). Therefore, for each 522 feet in a consistent 1 mho/meter media, an 8.69 db loss occurs. Skin depth may be calculated using the following equation.
Skin Depth=δ=1/√ (πfμσ) where:
π=3.1417;
f=frequency (hz);
μ=permeability (4π×10 6 ); and
σ=conductance (mhos/meter).
As should be apparent, the higher the conductance of the transmission media, the lower the frequency must be to achieve the same transmission distance. Likewise, the lower the frequency, the greater the distance of transmission with the same amount of power.
A typical electromagnetic telemetry system that transmits vertically through the earth's strata may successfully propagate through ten (10) skin depths. In the example above, for a skin depth of 522 feet, the total transmission and successful reception depth would only be 5,220 feet. It has been found, however, that in offshore applications, the boundary between the sea and the sea floor has a nonuniform and unexpected electrical discontinuity. Conventional electromagnetic systems are, therefore, unable to effectively transmit or receive the electromagnetic signals through the boundary between the sea and the sea floor. Additionally, it has been found that conventional electromagnetic systems are unable to effectively transmit the electromagnetic signals through sea water or through the boundary layer between the sea and air.
Therefore, a need has arisen for a system that is capable of telemetering real time data between the surface and downhole devices using electromagnetic waves to carry the information. A need has also arisen for an electromagnetic telemetry system that is capable of transmitting and receiving electromagnetic signals below the sea floor and relaying the information carried in the electromagnetic signals through the sea water to the surface. Further, a need has arisen for such an electromagnetic telemetry system that is capable communicating commands to specific downhole devices and receiving confirmation that the operation requested in the command has occurred.
SUMMARY OF THE INVENTION
The present invention disclosed herein comprises a subsea template electromagnetic telemetry system that is capable of telemetering real time data between the surface and downhole devices using electromagnetic waves to carry the information. The system transmits and receives electromagnetic signals below the sea floor and relays the information carried in the electromagnetic signals through the sea water to the surface. The system provides a method to communicate commands to specific downhole devices and receiving confirmation that the operation requested in the command has occurred.
The subsea template electromagnetic telemetry system comprises an electromagnetic downlink and pickup apparatus that includes a subsea conductor and a surface installation. The subsea conductor may be, for example, a subsea template of an offshore production platform. The subsea conductor and the surface installation are electrically connected using a pair of conduits. The conduits form a pair terminals on the subsea conductor between which a voltage potential may be established, thereby providing a path for current flow therebetween.
The surface installation includes a signal generator and a signal receiver. The signal generator injects a current carrying information into the subsea conductor that will generate electromagnetic waves carrying the information which are propagated downhole through the earth. The signal receiver interprets information carried in a current generated in the subsea conductor by electromagnetic waves received by the subsea conductor.
The conduits electrically connecting the subsea conductor to the surface installation may be electrical wires. Alternatively, one or both of the conduits electrically connecting the subsea conductor to the surface installation may be riser pipes including platform legs, conductor pipes of wells and the like.
The subsea conductor may have an electrical coupling extending outwardly therefrom and extending above the sea floor to provide a connection between an electric wire and the subsea conductor. The electrical coupling may be a post, a ring or the like.
The electromagnetic downlink and pickup apparatus may be used with the telemetry system for changing the operational state of a downhole device. In this case, the surface installation transmits a command signal to the subsea conductor. The subsea conductor retransmits the command signal using electromagnetic waves. The electromagnetic waves are received by an electromagnetic receiver disposed in a wellbore. An electronics package electrically connected to the electromagnetic receiver and operably connected to the downhole device, generates a driver signal in response to the command signal that prompts the downhole device to change operational states.
The downhole portion of the system may include an electromagnetic transmitter disposed in the wellbore. The electromagnetic transmitter may transmit a verification signal to indicate that the command signal has been received and that the command has been executed or both. The verification signal is received by the subsea conductor that forwards the signal to the surface installation.
The system is capable of operating numerous downhole devices disposed in multiple wells extending from one or more platforms. To achieve this result, the command signal generated by the surface installation are uniquely associated with specific downhole devices.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, including its features and advantages, reference is now made to the detailed description of the invention, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic illustration of an offshore oil and gas production platform operating a subsea template electromagnetic telemetry system of the present invention;
FIGS. 2A-2B are quarter-sectional views of a sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 3 is a schematic illustration of a toroid having primary and secondary windings wrapped therearound for a sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 4 is an exploded view of one embodiment of a toroid assembly for use as a receiver for a sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 5 is an exploded view of one embodiment of a toroid assembly for use as a transmitter for a sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 6 is a perspective view of an annular carrier of an electronics package for a sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 7 is a perspective view of an electronics member having a plurality of electronic devices thereon for sonde of a subsea template electromagnetic telemetry system of the present invention;
FIG. 8 is a perspective view of a battery pack for a sonde of a subsea template electromagnetic telemetry system of
FIG. 9 is a block diagram of a signal processing method used by a sonde of a subsea template electromagnetic telemetry system of the present invention; and
FIGS. 10A-B are flow diagrams of a method for operating a subsea template electromagnetic telemetry system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
Referring to FIG. 1, a subsea template electromagnetic telemetry system in use on an offshore oil and gas platform is schematically illustrated and generally designated 10. A production platform 12 is centered over submerged oil and gas formations 14, 15 located below sea floor 16. Wellheads 18, 20, 22 are located on deck 24 of platform 12. Wells 26, 28, 30 extend through the sea 32 and penetrate the various earth strata including formations 14, 15, forming, respectively, wellbores 34, 36, 38, each of which may be cased or uncased. Wellbore 36 includes a lateral or branch wellbore 37 that extends from the primary wellbore 36. The lateral wellbore 37 is completed in formation 15 which may be isolated for selective production independent of production from formation 14 into wellbore 36. Also extending from wellheads 18, 20, 22 are tubing 40, 42, 44 which are respectively, disposed in wellbores 34, 36, 38. Tubing 43 is disposed in lateral wellbore 37 and may join tubing 42 for production thererhrough.
Wells 26, 28, 30 along with legs 41, 45 extend through subsea template 47. Subsea template 47 helps to support platform 12 and allows for the accurate positioning of wells 26, 28, 30. Extending outwardly from subsea template 47 is coupling 49 which may be a ring, a post or the like. Coupling 49 is electrically connected to electrical wire 51 that extends through sea 32 and terminates at surface installation 58. An electrical wire 60 connects surface installation 58 to the conductor pipe of well 30. Thus, a complete electric circuit is formed that includes subsea template 47, coupling 49, electrical wire 51, surface installation 58, electrical wire 60 and the conductor pipe of well 30.
Surface installation 58 may be composed of a computer system that processes, stores and displays information relating to formations 14, 15 such as production parameters including temperature, pressure, flow rates and oil/water ratio. Surface installation 58 also maintains information relating to the operational states of the various downhole devices located in wellbores 34, 36, 37, 38. Surface installation 58 may include a peripheral computer or a work station with a processor, memory, and audio visual capabilities. Surface installation 58 includes a power source for producing the necessary energy to operate surface installation 58 as well as the power necessary to generate a current between electrical coupling 49 and well 30 through subsea template 47. This current will, in turn, generate electromagnetic wave fronts 65. As such, surface installation 58 is used to generate command signals that will operate various downhole devices. Electrical wires 51, 60 may be connected to surface installation 58 using an RS-232 interface.
As part of the final bottom hole assembly prior to production, a sonde 46 is disposed within wellbore 38. Likewise, sondes 48, 50, 53 are respectively disposed within wellbores 36, 34, 37. Sonde 46 includes an electromagnetic transmitter 52, an electronics package 54 and an electromagnetic receiver 56. Also disposed in wellbore 38 are sensors 67 which may obtain, for example, temperature, pressure, flowrate, or fluid composition data relating to production from formation 14. Thus, if the operator needs to obtain real time information from formation 14, surface installation 58 would generate a request for information by injecting a modulated current through subsea template 47 between coupling 49 and well 30. The current will produce the modulated electric and magnetic fields of electromagnetic wave fronts 65 to communicate the request to sonde 46. Electromagnetic wave fronts 65 are picked up by electromagnetic receiver 56 of sonde 46 and passed on to electronics package 54 for processing and amplification. Electronics package 54 interfaces with sensors 67 requesting the desired information.
Once sensors 67 obtain the information, the information is returned to electronics packages 54 for processing. Electronics package 54 then establishes the frequency, power and phase output of the information prior to forwarding the information to electromagnetic transmitter 52 of sonde 46 that radiates electromagnetic wave fronts 64 into the earth. The electric field of electromagnetic wave fronts 64 will generate a modulated current in subsea template 47 between coupling 49 and well 30 which serve as electrodes for sensing the voltage therebetween. The information then travels to surface installation 58 via electrical wave 51. The information may then be processed by surface installation 58 and placed in a useable format.
AlternativeLy, if the operator wanted to reduce the flow rate of production fluids in well 28, surface installation 58 would be used to generate a command signal to restrict the opening of bottom hole choke 62. The command signal would be injected into subsea template 47 via electrical wire 51. The command signal would then be radiated into the earth in the form of electromagnetic wave fronts 65. Electromagnetic wave fronts 54 are picked up by electromagnetic receiver 66 of sonde 48. The command signal is then forwarded to electronics package 68 of sonde 48 for processing and amplification. Electronics package 68 interfaces with bottom hole choke 62 and sends a driver signal to bottom hole choke 62 to restrict the flow rate therethrough.
Once the flow rate in well 28 has been restricted by bottom hole choke 62, bottom hole choke 62 interfaces with electronics package 68 of sonde 48 to provide verification that the command generated by surface installation 58 has been accomplished. Electronics package 68 then sends the verification signal to electromagnetic transmitter 70 of sonde 48 that radiates electromagnetic wave fronts 72 into the earth which are picked up by subsea template 47 and passed onto surface installation 58 via electrical wire 51 as describe above.
As another example, the operator may want to shut in production in lateral wellbore 37. As such, surface installation 58 would generate the shut in command signal and inject it into subsea template 47. Electromagnetic wave fronts 65 are then generated as described above. The shut in command would be packed up by electromagnetic receiver 55 of sonde 53 and processed in electronics package 57 of sonde 53. Electronics package 57 interfaces with valve 59 causing valve 59 to close. This change in the operational state of valve 59 would be verified to surface installation 58 as described above, by radiating electromagnetic wave fronts 61 from electromagnetic transmitter 63 which generate a current in subsea template 47 that relays the verification to surface installation 58 via electrical wire 51.
Similarly, the operator may want to actuate a sliding sleeve in a selective completion with sliding sleeves 74. A command signal would again be generated by surface installation 58 and injected into subsea template 47 via electrical wire 51. Electromagnetic wave fronts 65 would then be generated, thereby transmitting the command signal to electromagnetic receiver 76 of sonde 50. The command signal is forwarded to electronics package 78 for processing, amplification and generation of a driver signal. Electronics package 78 then interfaces with sliding sleeves 80, 82 and sends the driver signal to shut off production from the lower portion of formation 14 by closing sliding sleeve 82 and allow production from the upper portion of formation 14 by opening sliding sleeve 80. Sliding sleeves 80, 82 interface with electronics package 78 of sonde 50 to provide verification information regarding their respective changes in operational states. This information is processed and passed to electromagnetic transmitter 84 which generates electromagnetic wave fronts 86. Electromagnetic wave fronts 86 propagated through the earth and are picked up by subsea template 47. The verification information is then passed onto surface installation 58 via electrical wire 51 for analysis and storage.
Each of the command signals generated by surface installation 58 is uniquely associated with a particular downhole device such as bottom hole choke 62, valve 59, sensors 67 or sliding sleeves 80, 82. Thus, as will be further discussed with reference to FIGS. 9 and 10 below, electronics package 68 of sonde 46 will only process a command signal that is uniquely associated with a downhole device, such as bottom hole choke 62, located within wellbore 36. Similarly, electronics package 57 of sonde 46 will only process a command signal that is uniquely associated with a downhole device, such as valve 59, located within wellbore 37, while electronics package 54 of sonde 46 will only process a command signal that is uniquely associated with a downhole device, such as sensors 67, located within wellbore 38 and electronics package 78 of sonde 50 will only process a command signal uniquely associated with a downhole device, such as sliding sleeves 80, 82, located within wellbore 34. Thus, the subsea template electromagnetic telemetry system of the present invention allows for the monitoring of well data and the control of multiple downhole devices located in multiple wells from one central point.
Even though FIG. 1 depicts three wells 26, 28, 30 extending from a single platform 12, it should be apparent to those skilled in the art that the principles of the present invention are applicable to a single platform having any number of wells or to multiple platforms so long as the wells are within the transmission range of the electromagnetic wave such as electromagnetic wave fronts 65 from the master platform such as platform 12. It should be noted, that the transmission range of electromagnetic waves such as electromagnetic wave fronts 65 is significantly greater when transmitting horizontally through a single or limited number of strata as compared with transmitting vertically through numerous strata. For example, electromagnetic waves such as electromagnetic wave fronts 65 may travel between 3,000 and 6,000 feet vertically while traveling between 15,000 and 30,000 feet horizontally depending on factors such as the voltage, the frequency of transmission, the conductance of the transmission media, and the level of noise. The transmission range of electromagnetic waves such as electromagnetic wave fronts 65 may be extended, however, using electromagnetic repeaters that may extend either the vertical or horizontal transmission range or both.
Even though FIG. 1 depicts well 30 as completing the electrical circuit between surface installations 58 and subsea template 47, it should be understood by those skilled in the art that a variety of electrical connections could be used to complete the electrical circuit including, but not limited to, wells 26, 28, legs 41, 45 or other riser pipe in electrical contact with subsea template 47. Also, it should be understood by those skilled in the art that the current injected by surface installation 58 may travel either from well 30 to coupling 49 or from coupling 49 to well 30 for the generation of electromagnetic wave fronts 65. Similarly, it should be understood by those skilled in the art that the current generated between well 30 and coupling 49 by electromagnetic waves such as electromagnetic wave fronts 61, 64, 72, 86 may travel either from well 30 to coupling 49 and up electrical wire 51 to surface installation 58 or from coupling 49 to well 30 and up the conductor pipe of well 30 to surface installation 58.
Representatively illustrated in FIGS. 2A-2B is a sonde 77 of the present invention. For convenience of illustration, FIGS. 2A-2B depict sonde 77 in a quarter sectional view. Sonde 77 has a box end 79 and a pin end 81 such that sonde 77 is threadably adaptable to other tools in a final bottom hole assembly. Sonde 77 has an outer housing 83 and a mandrel 85 having a full bore so that when sonde 77 is disposed within a well, tubing may be inserted therethrough. Housing 83 and mandrel 85 protect the operable components of sonde 77 during installation and production.
Housing 83 of sonde 77 includes an axially extending and generally tubular upper connecter 87. An axially extending generally tubular intermediate housing member 89 is threadably and sealably connected to upper connecter 87. An axially extending generally tubular lower housing member 90 is threadably and sealably connected to intermediate housing member 89. Collectively, upper connecter 87, intermediate housing member 89 and lower housing member 90 form upper subassembly 92. Upper subassembly 92 is electrically connected to the section of the casing above sonde 77.
An axially extending generally tubular isolation subassembly 94 is securably and sealably coupled to lower housing member 90. Disposed between isolation subassembly 94 and lower housing member 90 is a dielectric layer 96 that provides electric isolation between lower housing member 90 and isolation subassembly 94. Dielectric layer 96 is composed of a dielectric material, such as teflon, chosen for its dielectric properties and capably of withstanding compression loads without extruding.
An axially extending generally tubular lower connecter 98 is securably and sealably coupled to isolation subassembly 94. Disposed between lower connecter 98 and isolation subassembly 94 is a dielectric layer 100 that electrically isolates lower connecter 98 from isolation subassembly 94. Lower connecter 98 is electrically connected to the portion of the casing below sonde 77.
It should be apparent to those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward, etc. are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. It is to be understood that the downhole component described herein, for example, sonde 77, may be operated in vertical, horizontal, inverted or inclined orientations without deviating from the principles of the present invention.
Mandrel 85 includes axially extending generally tubular upper mandrel section 102 and axially extending generally tubular lower mandrel section 104. Upper mandrel section 102 is partially disposed and sealing configured within upper connecter 87. A dielectric member 106 electrically isolates upper mandrel section 102 from upper connecter 87. The outer surface of upper mandrel section 102 has a dielectric layer disposed thereon. Dielectric layer 108 may be, for example, a teflon layer. Together, dielectric layer 108 and dielectric member 106 serve to electrically isolate upper connecter 87 from upper mandrel section 102.
Between upper mandrel section 102 and lower mandrel section 104 is a dielectric member 110 that, along with dielectric layer 108, serves to electrically isolate upper mandrel section 102 from lower mandrel section 104. Between lower mandrel section 104 and lower housing member 90 is a dielectric member 112. On the outer surface of lower mandrel section 104 is a dielectric layer 114 which, along with dielectric member 112, provides for electric isolation of lower mandrel section 104 from lower housing number 90. Dielectric layer 114 also provides for electric isolation between lower mandrel section 104 and isolation subassembly 94 as well as between lower mandrel section 104 and lower connecter 98. Lower end 116 of lower mandrel section 104 is disposed within lower connecter 98 and is in electrical communication with lower connecter 98. Intermediate housing member 89 of outer housing 83 and upper mandrel section 102 of mandrel 85 define annular area 118. A receiver 120, an electronics package 122 and a transmitter 124 are disposed within annular area 118.
In operation, sonde 77 receives a command signal in the form of electromagnetic wave fronts 65 generated by subsea template 47 of FIG. 1. Electromagnetic receiver 120 forwards the command signal to electronics package 122 via electrical conductor 126. Electronics package 122 processes the command signal as will be discussed with reference to FIGS. 9 and 10 and generates a driver signal. The driver signal is forwarded to the downhole device uniquely associated with the command signal to change the operational state of the downhole device. A verification signal is returned to electronics package 122 from the downhole device and is processed and forwarded to electromagnetic transmitter 124. Electromagnetic transmitter 124 transforms the verification signal into electromagnetic waves which are radiated into the earth and picked up by subsea template 47 and passed to surface installation 58 via electrical wire 51.
Referring now to FIG. 3, a schematic illustration of a toroid is depicted and generally designated 180. Toroid 180 includes magnetically permeable annular core 182, a plurality of electrical conductor windings 184 and a plurality of electrical conductor windings 186. Windings 184 and windings 186 are each wrapped around annular core 182. Collectively, annular core 182, windings 184 and windings 186 serve to approximate an electrical transformer wherein either windings 184 or windings 186 may serve as the primary or the secondary or the transformer.
In one embodiment, the ratio of primary windings to secondary windings is 2:1. For example, the primary windings may include 100 turns around annular core 182 while the secondary windings may include 50 turns around annular core 182. In another embodiment, the ratio of secondary windings to primary windings is 4:1. For example, primary windings may include 10 turns around annular core 182 while secondary windings may include 40 turns around annular core 182. It will be apparent to those skilled in the art that the ratio of primary windings to secondary windings as well as the specific number of turns around annular core 182 will vary based upon factors such as the diameter and height of annular core 182, the desired voltage, current and frequency characteristics associated with the primary windings and secondary windings and the desired magnetic flux density generated by the primary windings and secondary windings.
Toroid 180 of the present invention may serve, for example, as electromagnetic receiver 120 or electromagnetic transmitter 124 of FIG. 2. The following description of the orientation of windings 184 and windings 186 will therefore be applicable to each of the above.
With reference to FIGS. 2 and 3, windings 184 have a first end 188 and a second end 190. First end 188 of windings 184 is electrically connected to electronics package 122. When toroid 180 serves as electromagnetic receiver 120, windings 184 serve as the secondary wherein first end 188 of windings 184 feeds electronics package 122 with the command signal via electrical conductor 126. The command signal is processed by electronics package 122 as will be further described with reference to FIGS. 9, 10 below. When toroid 180 serves as electromagnetic transmitter 124, windings 184 serve as the primary wherein first end 188 of windings 184, receives the verification signal from electronics package 122 via electrical conductor 128. Second end 190 of windings 184 is electrically connected to upper subassembly 92 of outer housing 83 which serves as a ground.
Windings 186 of toroid 180 have a first end 192 and a second end 194. First end 192 of windings 186 is electrically connected to upper subassembly 92 of outer housing 83. Second end 194 of windings 186 is electrically connected to lower connecter 98 of outer housing 83. First end 192 of windings 186 is thereby separated from second end 192 of windings 186 by isolations subassembly 94 which prevents a short between first end 192 and second end 194 of windings 186.
When toroid 180 serves as electromagnetic receiver 120, electromagnetic wave fronts, such as electromagnetic wave fronts 65 induce a current in windings 186, which serve as the primary. The current induced in windings 186 induces a current in windings 184, the secondary, which feeds electronics package 122 as described above. When toroid 180 serves as electromagnetic transmitter 124, the current supplied from electronics package 122 feeds windings 184, the primary, such that a current is induced in windings 186, the secondary. The current in windings 186 induces an axial current on the casing, thereby producing electromagnetic waves.
Due to the ratio of primary windings to secondary windings, when toroid 180 serves as electromagnetic receiver 120, the signal carried by the current induced in the primary windings is increased in the secondary windings. Similarly, when toroid 180 serves as electromagnetic transmitter 124, the current in the primary windings is increased in the secondary windings.
Referring now to FIG. 4, an exploded view of a toroid assembly 226 is depicted. Toroid assembly 226 may be designed to serve, for example, as electromagnetic receiver 120 of FIG. 2. Toroid assembly 226 includes a magnetically permeable core 228, an upper winding cap 230, a lower winding cap 232, an upper protective plate 234 and a lower protective plate 236. Winding caps 230, 232 and protective plates 234, 236 are formed from a dielectric material such as fiberglass or phenolic. Windings 238 are wrapped around core 228 and winding caps 230, 232 by inserting windings 238 into a plurality of slots 240 which, along with the dielectric material, prevent electrical shorts between the turns of winding 238. For illustrative purposes, only one set of winding, windings 238, have been depicted. It will be apparent to those skilled in the art that, in operation, a primary and a secondary set of windings will be utilized by toroid assembly 226.
FIG. 5 depicts an exploded view of toroid assembly 242 which may serve, for example, as electromagnetic transmitter 124 of FIG. 2. Toroid assembly 242 includes four magnetically permeable cores 244, 246, 248 and 250 between an upper winding cap 252 and a lower winding cap 254. An upper protective plate 256 and a lower protective plate 258 are disposed respectively above and below upper winding cap 252 and lower winding cap 254. In operation, primary and secondary windings (not pictured) are wrapped around cores 244, 246, 248 and 250 as well as upper winding cap 252 and lower winding cap 254 through a plurality of slots 260.
As should be apparent from FIGS. 4 and 5, the number of magnetically permeable cores such as core 228 and cores 244, 246, 248 and 250 may be varied, dependent upon the required length for the toroid as well as whether the toroid serves as a receiver, such as toroid assembly 226, or a transmitter, such as toroid assembly 242. In addition, as will be known by those skilled in the art, the number of cores will be dependent upon the diameter of the cores as well as the desired voltage, current and frequency carried by the primary windings and the secondary windings, such as windings 238.
Turning next to FIGS. 6, 7 and 8 collectively, therein are depicted the components of an electronics package 195 of the present invention. Electronics package 195 may serve as the electronics package used in the sondes described above. Electronics package 195 includes an annular carrier 196, an electronics member 198 and one or more battery packs 200. Annular carrier 196 is disposed between outer housing 83 and mandrel 85. Annular carrier 196 includes a plurality of axial openings 202 for receiving either electronics member 198 or battery packs 200.
Even though FIG. 8 depicts four axial openings 202, it should be understood by one skilled in the art that the number of axial openings in annular carrier 196 may be varied. Specifically, the number of axial openings 202 will be dependent upon the number of battery packs 200 that are required.
Electronics member 198 is insertable into an axial opening 202 of annular carrier 196. Electronics member 198 receives a command signal from first end 188 of windings 184 when toroid 180 serves as, for example, electromagnetic receiver 120 of FIG. 2. Electronics member 198 includes a plurality of electronic devices such as limiter 204, preamplifier 206, notch filter 208, bandpass filters 210, phase lock loop 212, clock 214, shift registers 216, comparators 218, parity check 220, storage device 222, and amplifier 224. The operation of these electronic devices will be more full discussed with reference to FIGS. 9 and 10.
Battery packs 200 are insertable into axial openings 202 of axial carrier 196. Battery packs 200, which includes batteries such as nickel cadmium batteries or lithium batteries, are configured to provide the proper operating voltage and current to the electronic devices of electronics member 198 and to toroid 180.
Turning now to FIG. 9 and with reference to FIG. 1, one embodiment of the method for processing the command signal is described. The method 500 utilizes a plurality of electronic devices such as those described with reference to FIG. 7. Method 500 provides for digital processing of the command signal generated by surface installation 58 and transmitted via electromagnetic wave fronts 65. Limiter 502 receives the command signal from electromagnetic receiver 504. Limiter 502 may include a pair of diodes for attenuating the noise in the command signal to a predetermined range, such as between about 0.3 and 0.8 volts. The command signal is then passed to amplifier 508 which may amplify the command signal to a predetermined voltage suitable for circuit logic, such as 5 volts. The command signal is then passed through a notch filter 508 to shunt noise at a predetermined frequency, such as 60 hertz. The command signal then enters a bandpass filter 510 to attenuate high noise and low noise and to recreate the original waveform having the original frequency, for example, two hertz.
The command signal is then fed through a phase lock loop 512 that is controlled by a precision clock 513 to assure that the command signal which passes through bandpass filter 510 has the proper frequency and is not simply noise. As the command signal will include a certain amount of carrier frequency first, phase lock loop 512 will verify that the received signal is, in fact, a command signal. The command signal then enters a series of shift registers that perform a variety of error checking features.
Sync check 514 reads, for example, the first six bits of the information carried in the command signal. These first six bits are compared with the six bits stored in comparator 516 to determine whether the command signal is carrying the type of information intended for a sonde, such as sondes 46, 48, 50, 53. For example, the first 6 bits in the preamble of the command signal must carry the code stored in comparator 516 in order for the command signal to pass through sync check 514. Each of the sondes of the present invention, such as sonde 46, 48, 50, 53 may use the same code in comparator 516.
If the first six bits in the preamble correspond with that in comparator 516, the command signal passes to an identification check 518. Identification check 518 determines 14, whether the command signal is uniquely associated with a specific downhole device controlled by that sonde. For example, the comparator 520 of sonde 48 will require a specific binary code while comparator 520 of sonde 50 will require a different binary code. Specifically, if the command signal is uniquely associated with bottom hole choke 62, the command signal will include a binary code that will correspond with the binary code stored in comparator 520 of sonde 48.
After passing through identification check 515, the command signal is shifted into a data register 520 which is in communication with a parity check 522 to analyze the information carried in the command signal for errors and to assure that noise has not infiltrated and abrogated the data stream by checking the parity of the data stream. If no errors are detected, the command signal is shifted into storage registers 524, 526. For example, once the command signal has been shifted into storage register 524, a binary code carried in the command signal is compared with that stored in comparator 528. If the binary code of the command signal matches that in comparator 528, the command signal is passed onto output driver 530. Output driver 530 generates a driver signal that is passed to the proper downhole device such that the operational state of the downhole device is changed. For example, sonde 50 may generate a driver signal to change the operational state of sliding sleeve 82 from open to close.
Similarly, the binary code in the command signal stored in storage register 526 is compared with that in comparator 532. If the binary codes match, comparator 532 forwards the command signal to output driver 534. Output driver 534 generates a driver signal to operate another downhole device. For example, sonde 50 may generate a driver signal to change the operational state of sliding sleeve 80 from closed to open to allow formation fluids from the top of formation 14 to flow into well 26.
Once the operational state of the downhole device has been changed according to the command signal, a verification signal is generated and returned to sonde 50. The verification signal is processed by sonde 50 and passed on to electromagnetic transmitter 84 of sonde 50. Electromagnetic transmitter 84 transforms the verification signal into electromagnetic wave fronts 86, which are radiated into the earth to be picked up by subsea template 47. As explained above, the verification signal is then forwarded to surface installation 58 via electrical wire 51.
Even though FIG. 9 has described sync check 514, identifier check 518, data register 520 and storage registers 524, 526 as shift registers, it should be apparent to those skilled in the art that alternate electronic devices may be used for error checking and storage including, but not limited to, random access memory, read only memory, erasable programmable read only memory and a microprocessor.
In FIGS. 10A-B, a method for operating a subsea template electromagnetic telemetry system of the present invention is shown in a block diagram generally designated 600. The method begins with the generation of a command signal 602 by surface installation 58. When the command signal 602 is generated, a timer 604 is set. If the command signal 602 is a new message 606, surface installation 58 initiates the transmission of command signal 602 in step 608. if command signal 602 is not a new message, it must be acknowledged in step 607 prior to being transmitted in step 608.
Transmission 608 involves sending the command signal 602 to subsea template 47 via electrical wire 51 and generating electromagnetic wave fronts 65. The sondes listen for the command signal 602 in step 610. When a command message 602 is received by a sonde in step 612, the command signal 602 is verified in step 614 as described above with reference to FIG. 9. If the sonde is unable to verify the command signal 602, and the timer has not expired in step 616, the sonde will continue to listen for the command signal in step 610. If the timer has expired in step 616, and a second time out occurs in step 618, the command signal is flagged as a bad transmission in step 620.
If the command signal 602 is requesting a change in the operational state of a downhole device, a driver signal is generated in step 622 such that the operational state of the downhole device is changed in step 624. Once the operational state of the downhole device has been chanced, the sonde receives a verification signal from the downhole device in step 626. If the verification signal is not received, the sonde will again attempt to change the operational state of the downhole device in step 624. If a verification signal is not received after the second attempt to change the operational state of the downhole device, in step 628, a message is generated indicating that there has been a failure to change the operational state of the downhole device.
The status of the downhole device, whether operationally changed or not, is then transmitted by the sondre in step 630. The surface installation listens for the carrier in step 632 and receives the status signal in step 634, which is verified by the surface installation in step 636. If the surface installation does not receive the status message in step 634, the surface installation continues to listen for a carrier in step 632. If the timer has expired in step 638, and a second time out has occurred in step 640, the transmission is flagged as a bad transmission in step 642. Also, if the surface installation is unable to verify the status of the downhole device in step 636, the surface installation will continue to listen for a carrier in step 632. If the timers in steps 638, 640 have expired, however, the transmission will be flagged as a bad transmission in step 642.
In addition, the method of the present invention includes a check back before operate loop which may be used prior to the actuation of a downhole device. In this case, command message 602 will not change the operational slate of a downhole device, in step 622, rather the sonde will simply acknowledge the command signal 602 in step 644. The surface installation will listen for a carrier in step 646, receive the acknowledgment in step 648 for verification in step 650. If the surface installation does not receive the acknowledgment in step 648, the surface installation will continue to listen for a carrier in step 646. If the timers have expired in steps 652, 654, the transmission will be flagged as a bad transmission in step 620. Additionally, if the surface installation is unable to verify the acknowledgment in step 650, the surface installation will continue to listen for a carrier in step 646. If the timers in step 652 and step 654 have timed out, however, the transmission will be flagged as a bad transmission in step 620.
While this invention has been described with a reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations 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, intended that the appended claims encompass any such modifications or embodiments.
|
An electromagnetic downlink and pickup apparatus for transmitting and receiving electromagnetic signals is disclosed. The electromagnetic downlink and pickup apparatus includes a subsea conductor (47) disposed beneath the sea floor (16) and a surface installation (58) for generating and interpreting signals. The subsea conductor (47) and the surface installation (58) are electrically connecting by first and second conduits (30, 51) that form a pair terminals on the subsea conductor (47) between which a voltage potential may be established, thereby providing a path for current flow therebetween.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/947,513, filed on Nov. 20, 2015, which is a Continuation of U.S. patent application Ser. No. 13/117,729, filed on May 27, 2011, now U.S. Pat. No. 9,203,940, which is a Continuation of U.S. patent application Ser. No. 12/163,948, filed Jun. 27, 2008, now U.S. Pat. No. 8,224,379, which is a Continuation of U.S. patent application Ser. No. 09/976,475, filed on Oct. 12, 2001, now U.S. Pa. No. 7,395,089, which claims priority and benefit under 35 USC §119(e) to U.S. Provisional Patent Application No. 60/297,817, filed on Jun. 11, 2001, each of which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] The present invention is related generally to a user interface for a personal digital assistant device.
DESCRIPTION OF RELATED ART
[0003] Carrying a personal digital assistant (PDA) around is very convenient for tasks such as taking notes at a meeting or lecture, scheduling appointments, looking up addresses, and for performing a whole host of other functions. However, one function not easily performed with a PDA is that of telecommunications. A typical cellular telephone, meanwhile, offers a range of features, from speed dial to speakerphone to caller-ID, phonebook, etc. In order to have the functionality of a cellular telephone and the functionality of a PDA, consumers have generally had to choose from a selection of largely unsatisfactory options. The most common option is to carry both a PDA and cell phone. This is undesirable, however, because of the obvious impractical aspects of having to deal with two separate devices, both in terms of sheer bulk as well as the inconvenience of switching between units. Simply put, there are more things to buy, more things to break, and more things to lose.
[0004] Another option is to purchase an add-on telephone device for a PDA. While this option is preferable to carrying two devices around, it still has limitations. For example, an add-on telephone device adds bulk to and changes the form factor of the PDA. In addition, since such a PDA must be designed to operate without an add-on telephone, the degree to which the user interface of the PDA can be integrated with the user interface of the add-on telephone is limited. Thus, an add-on solution is of only limited value, since there is not a true integration between the cellular telephone device and the PDA, but rather two separate devices at best co-existing side-by-side.
[0005] Accordingly, what is needed is a system and method for providing a user interface to a device featuring integrated functionality of both a PDA and cellular telephone.
SUMMARY
[0006] In accordance with the present invention there is provided a system and method for using an integrated device featuring functionality of both a PDA and cellular telephone. Features of the present invention include a power button offering control of both the computing and telephony functions of the device; a lid that turns the device on and off depending on its state, and can also be used to begin and terminate calls; a jog rocker that activates the device and is used to select from a variety of menu options; application buttons that offer direct access to applications stored on the device, and which can be configured to operate in conjunction with secondary keys to offer added functionality; an override-able ringer switch; a keyboard; and an Auto Word Completion function that verifies and corrects a user's typing in real time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an illustration of a device with keyboard in accordance with an embodiment of the present invention.
[0008] FIG. 2 is an illustration of a device without keyboard in accordance with an embodiment of the present invention.
[0009] FIG. 3 is a flow chart illustrating power-on behavior of a device in accordance with an embodiment of the present invention.
[0010] FIG. 4 is a flow chart illustrating power-off behavior of a device in accordance with an embodiment of the present invention.
[0011] FIG. 5 is an illustration of a matrix describing behavior of a lid attached to a device in accordance with an embodiment of the present invention.
[0012] FIGS. 6 a and 6 b are illustrations of a keyboard layout in accordance with an embodiment of the present invention.
[0013] FIGS. 7 a and 7 b illustrates views of a display screen when Option mode and Option Lock mode are activate in accordance with an embodiment of the present invention.
[0014] FIG. 8 is an illustration of a dialog box presented to a user when a call is incoming in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0015] fir the discussion set forth below, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be appreciated by those skilled in the art that the present invention may be practiced without these specific details. In particular, those skilled in the art will appreciate that the methods described herein can be implemented in devices, systems and software other than the examples set forth. In other instances, conventional or otherwise well-known structures, devices, methods and techniques are referred to schematically or shown in block diagram form in order to facilitate description of the present invention.
[0016] The present invention includes steps that may be embodied in machine-executable software instructions, and includes method steps that are implemented as a result of one or more processors executing such instructions. In other embodiments, hardware elements may be employed in place of, or in combination with, software instructions to implement the present invention. The software instructions may be stored in RAM or ROM, or on other media including removable media.
[0017] The present invention includes a user interface for the operation of an integrated handheld personal computing device and wireless communication device. Referring now to FIG. 1 , there is shown an example of such an integrated device 100 . As illustrated in FIG. 1 , device 100 includes a base section 102 , a lid 104 , application and scroll buttons 106 , power button 110 , antenna 112 , jog rocker 114 , and ringer switch 116 , and display 118 . In addition, device 100 includes a keyboard 108 . As will be appreciated by those of skill in the art, the present invention may exist in a variety of embodiments, including embodiments in which the integrated device includes more or fewer physical components than are illustrated in FIG. 1 . For example, FIG. 2 illustrates another device 200 that does not have a keyboard, but instead has a writeable area 202 enabling input to the device 200 via, for example, a stylus. For convenience and clarity, device 100 of FIG. 1 serves as the illustration that will be referenced throughout this specification, but such reference should in no way be understood to restrict what is disclosed to such an embodiment.
[0018] Device 100 includes an integrated GSM radio (also referred to as a cellular telephone), and while in alternative embodiments is of varying sizes and shapes, in one embodiment the device is designed to fit comfortably in a pocket. While the radio uses the GSM standard in one embodiment, in alternative embodiments the radio may use the CDMA standard, or any of a variety of other well--known wireless standards.
Power Button
[0019] Device 100 has a power button 110 , located in one embodiment on the top face, next to the antenna 112 . In one embodiment, the power button 110 performs the following functions:
[0000] A single press and release of the power 110 button toggles device 100 on/off.
Pressing and holding the power button 110 toggles the radio on/off.
Double-tapping the power button 110 toggles a backlight on/off.
Triple-tapping the power button 110 inverts the display 118 and insures that the backlight is on.
A single press of the power button 110 when an incoming call is ringing silences the ring but does not turn off the device 100 .
[0020] Referring now to FIG. 3 , there is shown a flowchart of the operation of the power button functionality starting from a device-off state. Initially, the device 100 is off and the power key is pressed 300 . If the key is being pressed for the first time within a given period 302 (e.g., it has not been pressed for at least the previous half second), the device 100 is switched on 304 . If the power button is held down for longer than a threshold amount of time, e.g., 1 second 306 then the radio is toggled on or off 308 . If the power button is held down for less than the threshold amount 306 then upon release a countdown of predetermined length, ½ second, is begun 310 . If the power button is pressed 312 during the countdown, then the backlight is toggled on or off 314 . If the cycle is repeated and the power button is pressed for a third time during the countdown 312 , then the display 118 is inverted 316 , and the backlight is preferably turned on if it is not already on. If the power button is not pressed 312 during the countdown, then no additional actions take place as a result of the power button press. After the display is inverted in step 316 , the countdown is once again begun 318 . However, if the power button is pressed during this or subsequent countdowns 320 , the display is again inverted at step 316 . This countdown cycle continues until the power button is not pressed during the countdown 320 .
[0021] Referring now to FIG. 4 , there is shown a flowchart of the operation of the power button functionality starting from a device-on state. Initially, the device is on, and the power key is pressed 400 . If the power key is being pressed for the first time 402 (e.g., it has not been pressed for at least the previous half second), no action is initially taken. If the power button is held down for longer than a threshold amount of time, e.g., 1 second 404 then the radio is toggled on or off 406 . If the power button is held down for less than the threshold amount 404 , then upon release a countdown of predetermined length, e.g., ½ second, is begun 408 . If the power button is not pressed 410 during the countdown, then the device is turned off 416 . If the power button is pressed 410 during the countdown, then the backlight is toggled on or off 412 . If the cycle is repeated and the power button is pressed for a third time during the countdown, then the display is inverted 414 , and the backlight is turned on if not already on. After the display is inverted 414 , another countdown is begun 416 . If the power button is pressed again 418 during the countdown, then the display is once again inverted 414 , and countdown 416 restarted. This continues until the countdown expires without the power button being pressed 418 .
[0022] In addition, in one embodiment pressing the power button 110 when there is an incoming call silences the ring or vibrate. Further, if a call is in progress, pressing the power button turns off the device 100 but does not terminate the call. Finally, if the device is off when a call comes in, the device is turned on, and the backlight is illuminated, which helps to locate the device 100 , e.g., in a poorly-lit room.
Lid
[0023] Referring again to FIG. 1 , there is shown a view of device 100 , having a lid 104 attached to base 102 . In FIG. 1 , lid 104 is connected to base 102 via a hinge or other mechanism that allows lid 104 to open and close. Note that the lid 104 may be connected to base 102 in any of a variety of ways while still including features described herein. The particular embodiment of FIG. 1 is therefore meant to illustrate only one of many possible configurations.
[0024] In one embodiment, lid 104 features a hardware switch for lid open and lid close detection, and may additionally include an integrated speaker for flip phone-like functionality. When closed, in one embodiment, lid 104 covers all of base 102 except for application and scroll buttons 106 . In one embodiment, lid 104 also includes a transparent window for viewing the display 118 of device 100 while the lid 104 is closed.
[0025] The effect of opening and closing the lid 104 varies according to the state of device 100 at the time the lid 104 is opened or closed. In one embodiment, and referring now to FIG. 5 , opening and closing the lid 104 has the following effect:
[0026] If the device is off, opening the lid turns on the device 100 , and launches 502 a predetermined application. In one embodiment, the predetermined application is a speed dial view of a telephone application, however in other embodiments the application can be any application on the device 100 , assignable by the user in one embodiment via a preferences control panel-type application. If the device is off, closing the lid has no effect 504 .
[0027] If the device is on, then it is in one of three states: either a call is in progress, a call is incoming, or there is no call activity.
[0028] If a call is incoming, then an incoming call notification is given to the user. An illustration of such a notification is shown in FIG. 8 . It will be appreciated that a user may be in the process of opening the lid when a call comes in. In such a situation, the user may not want to actually take the incoming call. For that reason, if the lid is opened within, in one embodiment, one second of the incoming call notification, no action is taken 506 (although the user can still answer the call in other ways, e.g., by tapping a dialog box 802 on the display of device 100 ). In other embodiments, the time maybe shorter or longer than one second. If the lid is opened more than one second after the initial incoming call notification, then the call is answered 508 . Note also that in one embodiment a user can choose to accept or ignore any incoming telephone call by selecting the answer 802 or ignore 804 options presented in a popup dialog box.
[0029] Similarly, if the user is in the process of closing the lid when a call comes in, it is desirable to assume that the lid is being closed not in response to the incoming call, but rather by coincidence. Thus, if the lid is closed within an initial time, e.g., one second, of the first notification of an incoming call, no action is taken 510 . After this initial period, if the lid is closed, then in one embodiment the ring is silenced, the call is ignored, and the device is turned off 512 .
[0030] During an active call, the lid is open in a preferred embodiment, unless a headset is plugged in. If a call is in progress and the headset is being used, then opening the lid has no effect on the call 514 . If the lid is closed while a headset call is in progress, the device is turned off, but the call is not disconnected 516 . If a telephone call is in progress without using a headset, then closing the lid hangs up the telephone, in one embodiment after displaying a warning message confirming that the call is about to be disconnected, and turns the device off 518 . During the confirmation warning message, the user has the opportunity to tell the device not to disconnect the call, e.g. by pressing the scroll-up button. In alternative embodiments, the call is disconnected as soon as the lid is closed.
[0031] If a telephone call is not in progress, then in one embodiment, opening the lid when the device is already on has no effect 520 . That is, even if there is an application assigned to be launched upon the opening of the lid, when the power is already on, opening the lid does not launch the assigned application, but rather has no effect on what application is currently executing. Also, in one embodiment, if a call is not in progress, closing the lid turns the device off 522 .
[0032] In addition, in one embodiment keyboard 108 is deactivated when the lid 104 is closed, whether the device 100 is on or off. This guards against inadvertent input to the device when pressure is applied to the lid, e.g., if the device is carried in a pocket, or if something heavy is placed on top of the device. In alternative embodiments, the keyboard 108 remains active at all times regardless of lid position. In one embodiment, application and scroll buttons 106 remain active even when the lid 104 is closed. This allows the scroll buttons to be used to respond to dialog boxes that may be presented to the user when the lid is closed. For example, if an alarm goes off, the user can dismiss the alarm by pressing a scroll button, instead of having to open the lid to tap the display 118 or press a button on the keyboard 108 .
Jog Rocker
[0033] Device 100 includes a jog rocker 114 such as is pictured in FIG. 1 . A jog rocker in one embodiment allows four input actions: up, down, press in, and press and hold.
[0034] While individual applications provide specific responses to input from jog rocker 114 , in one embodiment pressing the jog rocker 114 when device 100 is turned off wakes device 100 up and launches a predefined application, such as the phone application in one embodiment.
[0035] In one embodiment, this behavior is executed on jog rocker 114 press, not release, so one embodiment, this behavior is executed on jog rocker 114 press, not release, so that a press and hold of the jog rocker 114 wakes the device up, launches the predefined application on the press, and then executes within the application whatever that application has specified for a jog rocker 114 hold on the hold.
[0036] In another embodiment, jog rocker 114 can be used to provide a scroll- up and scroll-down function similar to that provided by scroll buttons 106 . In one embodiment this is the default use for jog rocker 114 when an application does not provide additional functionality for the jog rocker.
Ringer Switch
[0037] Ringer switch 116 is used in a preferred embodiment to select whether incoming telephone calls should produce an audible ringing sound on device 100 . In a first position, device 100 produces such a ring tone, which is customizable in one embodiment using application software stored on device 100 . In a second position, device 100 does not produce a ring tone for an incoming call. In one embodiment, device 100 is configured to vibrate in response to an incoming telephone call. The vibrate feature of device 100 may additionally be activated by applications executing on device 100 , for example even when ringer switch 116 is in the first position (the audible ring position).
[0038] In one embodiment, when ringer switch 116 is in the second position, all sounds made by device 100 are muted, and not just the ring tone. Thus, for example, while a number of applications executed on device 100 , e.g., an alarm, a message alert, etc., may instruct device 100 to produce a sound, the location of the switch in the second position will stop device 100 from actually making the sounds. In yet another embodiment, device 100 allows software resident on device 100 to override the physical setting of ringer switch 116 . This may be of particular use, for example, if the ringer switch is in the first position while a call is in progress and it is undesirable to have sounds from device 100 interfering with the call in an annoying fashion.
Application Buttons
[0039] A device such as device 100 typically has one or more application and scroll buttons 106 located physically on the device, providing direct access to applications associated with the buttons, as well as up-down and left-right scroll functionality. Using a keyboard 108 of device 100 , different applications are assignable to the application buttons 106 being pressed in combination with a modifier key. In one embodiment, an “option” key is the modifier key for these key combinations.
[0040] In one embodiment, the following applications are mapped to option and (“+”) application button combinations:
[0000] Option+Phone Application button maps to Memo Pad.
Option+Calendar Application button maps to To-Do.
Option+Internet Browser Application button maps to City Time.
Option+Messaging Application button maps to the calculator.
[0041] In one embodiment, the Option+Application button key combination works both in series and in parallel. For example, pressing and releasing the Option button (a serial combination), then pressing an application button 106 launches the application that is mapped to that application button's option modification. Similarly, pressing and holding the Option button while pressing the application button 106 (a parallel combination) also launches that application button's option modification.
[0042] If the option modification times out before the application button 106 is pressed, then the functionality is the same as if only the application button had been pressed.
[0043] Pressing and holding Option, and then pressing an application button 106 while Option is still held down also launches the application that is mapped to that applications button's option modification. What occurs if the user continues to hold the application button in is controlled on an application-by-application basis.
[0044] In one embodiment, the following application buttons 106 and combinations are flappable:
[0000] a Phone Application button.
a Calendar Application button.
an Internet Browser Application button.
a Messaging Application button.
[0045] In alternative embodiments, the following; combinations are also mappable:
[0000] Option+Calendar Application button,
Option+Phone Application button.
Option+Internet Browser Application button.
Option+Messaging Application button.
Keyboard
[0046] In one embodiment, keyboard 108 includes the following keys:
[0000] a-z (26 keys)
. (period)
Symbol key
Space
Return
Backspace
Shift key
Option key
Menu key.
[0047] FIG. 6 a illustrates one embodiment of a keyboard 108 layout. In FIG. 6A , the bottom label of each key indicates its normal character, while the top left label indicates its shift key character, and the top right label indicates its option key character.
[0048] FIG. 6 b illustrations just the number/punctuation keys extracted from FIG. 6 a.
[0049] in an unmodified state, the keys produce the main character printed on them. In one embodiment, there is no on screen-modification state indicator for the unmodified keyboard state. In Shift state, the keys produce a capital version of the main character printed on them, as illustrated in FIG. 6 a.
[0050] In Option state, the keys produce the alternate character illustrated in FIG. 6 b.
[0051] in one embodiment, pressing the Option key once puts device 100 in Option state. Pressing Option in Option state puts the device in Option Lock state, Pressing Option in Option Lock state clears the state. Option state is canceled upon the entry of the Option-modified character. Option Lock state is not canceled upon the entry of the Option-modified character, hence the Lock-ness. Option state can be canceled without entering a character by pressing the Option key twice (once for lock, the second for clear) or pressing backspace. Note that in one embodiment, backspace cancels Option state, but not Option Lock state.
[0052] Referring now to FIG. 7 a , in one embodiment, an on-screen modification state indicator 702 for Option state, which indicates to the user that the Option key has been pressed, is an oval tilted to have the same appearance as the shape of the Option key itself.
[0053] Referring now to FIG. 7 b , the on-screen modification state indicator 704 for Option Lock state is similar to the Option state indicator except with a “bottom bar”.
[0054] Holding down a key for a prolonged period causes the key to repeat. In one embodiment, all text entry has the same repeat rate, i.e. holding down the j produces j's at the same rate as holding down shift+j produces J's and option +j produces 5's. The Option and Shift keys both “time out” if additional input is not received within a prescribed period of time, e.g., 3 seconds in one embodiment. Note that in one embodiment the Option Lock and Shift Lock states do not time out.
[0055] In addition, in a preferred embodiment, when the currently executing application on device 100 changes from a first application to a second application, the Shift state is cleared to avoid unintended Shifted input into the second application.
Auto Word Completion
[0056] in order to provide a fast and easy way to enter awkward or often-misspelled text, device 100 includes a word auto-completion/correction system that in one embodiment checks every word that a user enters against a database of common misspellings and convenient abbreviations and replaces the entered word with a preset correct or complete version of the word. For example, if a user enters ‘beleive’, it will automatically be replaced with ‘believe’. If a user enters ‘im’, it will be replaced with ‘I'm’.
[0057] In one embodiment, Word Completion executes whenever a user enters any character that signals that they are finished typing the previous word, e.g.:
Space
[0058] Any punctuation
Tab
Return
Next or Previous Field.
[0059] For instance, when a user types b,e,l,e,i,v,e the word ‘beleive’ is still displayed. If the user then enters a space (or any of the characters listed above) then ‘beleive’ is replace by believe'. Typing backspace once will erase the space (or tab, new line, etc.) that invoked the Word Completion. Typing backspace a second time will undo the word completion without deleting the last character of the word. At this point, typing any of the characters that usually invoke Word Completion will not invoke it again.
[0060] If the replacement, word in the database is not capitalized, then the capitalization of the word to be replaced is maintained. For instance, there is an entry in the Word Completion database that has the wrong word “feild” marked to be replaced with “field” so:
[0000] feild becomes field
Feild becomes Field.
[0061] If the replacement, word in the database is capitalized, then the resulting word is capitalized no matter what the capitalization of the word to be replaced was. For instance, there is an entry in the Word. Completion database that has the wrong word “im” marked to be replaced with “I'm” so:
[0000] im becomes I'm
lm becomes I'm.
[0062] Keyboard Navigation and Commands
[0063] In one embodiment, device 100 switches off or “sleeps” in order to conserve power after a predefined period of time. In such circumstance, pressing a. key on the keyboard 108 wakes the device back up, i.e. restoring the device to a power on state in the same condition that it was in prior to going to sleep. In other embodiments, waking the device 100 up is equivalent to a power on command, which starts the device with a predefined initial application. Note that the keys which will wake the device up may be predetermined, or may be changeable by the user.
[0064] In one embodiment, some navigational activities of device 100 are keyboard enabled. Buttons such as “OK,” “Done,” and “Cancel” are mapped to certain keys and key combinations. Common actions, which may also be on-screen buttons like “New” and “Details . . . ,”are frequently included as menu items. These menu items have menu button+letter combinations assigned to them so that they may be executed easily from the keyboard 108 .
[0065] In one embodiment, menus on device 100 are navigable via a menu key and menu mode. Pressing and releasing a dedicated hardware menu key on keyboard 108 displays a first pull-down menu of the current view. Pressing and releasing the menu key a second time dismisses the menu.
[0066] While the menu is being displayed, in one embodiment the user can navigate the menus and execute menu items with the following actions:
[0000] Scroll Up displays the next menu list to the right.
[0067] Scroll Up from the last menu list scrolls back to the first.
[0068] Holding Scroll Up repeats this action at the normal repeat rate.
[0000] Scroll Down moves a highlight down through the current displayed list of menu items.
[0069] If there is no highlighted item, such as when the menu list is first displayed, then the first press of Scroll Down highlights the first menu item.
[0070] Scroll Down from the last menu item in the list scrolls back to the first item in the same list.
[0071] Holding Scroll Down repeats this action at the normal repeat rate.
[0000] Space executes the :highlighted menu item on press.
Return also executes the highlighted menu item on press.
Backspace dismisses the menu.
At any time when any menu is displayed, pressing any of the short cut letters executes the corresponding menu item, even if that menu item is in a menu list that is not currently displayed.
Typing any character that is not detailed above or a short cut letter plays an error beep.
[0072] At any time, whether or not a menu is displayed, pressing and holding the menu key and pressing a one of the shortcut letters executes the corresponding menu item, in one embodiment, without the menu being drawn on the screen. Pressing and releasing the menu key and then pressing the shortcut letter will display the menu, however, in one embodiment.
[0073] Any menu that is being displayed is dismissed whenever a menu item is executed. Shift Lock and Option Lock are ignored when entering short cut letters. It is possible, however, to enter an option character as a short cut character in
[0000] User presses the menu button to enter menu mode.
User presses and holds Option.
User presses x for instance.
The menu item with the short cut character? would get executed, because the question mark (?) is formed by pressing Option-x.
Pressing and releasing Option and then pressing x would execute the menu item with the short cut letter x.
[0074] Menu mode itself will not clear the modification state, but the execution of a menu item may dear the modifications state depending on what that menu item does.
[0000] User starts in Option Lock.
User presses the menu button.
User presses the menu button again to dismiss the menu.
The user should still be in Option Lock.
[0075] Thus, when buttons containing certain text are on the screen, certain keys or key combinations can be pressed that will execute the buttons as if they were pressed on the screen.
[0000] The buttons that are mapped to the keyboard in one embodiment are:
[0076] OK
[0077] Done
[0078] Cancel
[0079] Yes
[0080] No
[0081] Next
[0082] Previous.
[0083] The following four keys/key combinations are used for mapping to certain common on-screen buttons in one embodiment:
Return
Backspace
Option+Return
Option+Backspace
[0084] Option+Return and Option+Backspace will work on in parallel.
[0085] Globally, in one embodiment:
[0000] Option+Return executes:
[0086] OK
[0087] Done
[0088] Yes
[0089] Next
[0090] Send
[0091] Accept
[0000] Option+Backspace executes:
[0092] Cancel
[0093] No
[0094] Previous
[0095] Back
[0096] Reject
[0097] In one embodiment, if there is no opportunity for text entry on a particular screen, then the holding down of the Option key may be unnecessary. Thus, for example, within the context of alert dialogs:
[0000] Return executes:
[0098] OK
[0099] Done
[0100] Yes
[0101] Next
[0102] Send
[0103] Accept
[0000] Backspace executes:
[0104] Cancel
[0105] No
[0106] Previous
[0107] Back
[0108] Reject
[0109] Return and Backspace do not map to buttons in other contexts in one embodiment, since in other contexts there will likely be text areas in which Return and Backspace benefit from their normal functionality.
[0110] In addition, in one embodiment the mappings described above also apply to non-English based applications. For example, Option+Return is mapped to “Oui” in a French language application. This allows a user to execute a foreign-language application on device 100 while providing similar functionality to an English-language application.
[0111] The foregoing discloses exemplary methods and embodiments of the present invention. It will be understood that the invention may be embodied in other forms and variations without departing from the spirit or scope of the invention. Accordingly, this disclosure of the present invention is illustrative, but not limiting, of the invention, the scope of which is defined by the following claims.
|
A mobile computing device is disclosed. In some aspects, the mobile computing device may execute a first application using one or more processors, and may receive, during execution of the first application, a user selection of a shift key. The mobile computing device may transition a state of the shift key from an unlocked non-shift state to a shift state based on the user selection. The mobile computing device may change the execution of the first application to an execution of a second application, and clear the state of the shift key in response to changing the execution from the first application to the second application.
| 8
|
The invention herein described relates generally to oil and gas production equipment and methods and, more particularly, to a gravel prepack production system and related apparatus and methodology which may be applied to short and ultra-short radius wells as well as medium and long radius wells.
BACKGROUND OF THE INVENTION
Horizontal wells are being widely used throughout the oil and gas industry to enhance project economics and to develop reservoirs that would otherwise not be commercially viable. Well productivity can be increased with horizontal wells and many fields have been developed for this reason. Horizontal wells have been completed in high productivity reservoirs for the purpose of reducing gas and/or water coning, thereby improving drainage efficiency and ultimate recovery.
Horizontal wells have been drilled and completed in poorly consolidated formations that typically have high permeability and high production potential. These formations, however, are often incapable of producing without some type of control technique for sand and other fine solids. Sand and fine solids produced with oil and gas are major causes of uneconomic production, resulting in excessive expense as well as wear and down time on pumps, tubing, traps and other equipment. The industry has recognized the use of gravel packed completions as a solution to sand control problems.
In normal vertical wells, the cost of gravel packing is usually less than ten percent of the total well cost. Because the benefits of a successful gravel pack include unrestricted productivity, long term performance and selective production capability, the decision to gravel pack is normally made without much difficulty. However, faced with production intervals from 10-30 times the typical completion length in a vertical well, operators must give extra consideration in horizontal wells where the completion cost could equal or exceed the drilling cost.
A conventional gravel packing technique involves locating a perforated liner at a subsurface location in the well and thereafter placing gravel around the perforated liner. A slurry of gravel suspended in a liquid carrier is pumped into the annular space between the formation wall and the liner. As the suspension reaches the bottom of the annulus the gravel is compactly deposited in the annulus on the exterior of the liner and the liquid carrier withdraws through the liner perforations and back up the casing string. In this manner the gravel progressively builds up in the annulus surrounding the liner.
A problem encountered with this technique arises when the well bore deviates from the vertical. When the well is inclined, the gravel oftentimes fails to pack uniformly, resulting in voids within the packed annulus which weaken the pack and permit the production of sand entrained fluids.
Various alternatives to such open hole gravel packs include the use of prepacked liners, i.e., gravel prepacks. A conventional gravel prepack has a layer of uniformly sized gravel contained between concentric screens such that fluid flow must pass through the gravel to enter the well bore. The gravel prepack may contain either loose or consolidated gravel, the latter offering more protection from erosion because the sand grains cannot settle, reorient or move which could allow formation sand to penetrate into the well bore. The screens may be, for example, perforated tubes or wire wrapped screens.
A problem with conventional gravel prepacks is their inability to pass through a severe dog-leg in the well. Many conventional gravel prepacks are too rigid to withstand deviations over 10-12 degrees per 100 feet.
SUMMARY OF THE INVENTION
The present invention provides for extension of the benefits afforded by gravel prepacks to wells in which high dog-leg severity previously inhibited or precluded use of conventional gravel prepacks. As a result of the present invention, wells may be drilled with shorter radii while maintaining a gravel prepack option.
In accordance with the invention, a gravel prepack to be installed in a hole formed in a fluid bearing formation to prevent sanding during production comprises an inner tube and a plurality of discrete annular filter elements carried on the inner tube and being relatively movable during flexing of the inner tube. The inner tube has openings therein for flow of fluid from the filter elements into the interior of the inner tube.
More particularly, each annular filter element includes axially spaced apart end caps at opposite axial ends of an interior chamber containing filter media, and radially outer and inner concentric screens extending between the end caps and surrounding the filter media in the interior chamber. Spacers are interposed between the annular filter elements to space them apart longitudinally along the inner tube. Preferably, the annular filter elements and spacers are strung onto the inner tube, and stop collars are mounted to the inner tube at opposite axial ends of the string for securing the string of annular filter elements and spacers against axial movement along the inner tube. The inner tube may be perforated in the regions between the spaced apart filter elements, and the spacers surround the intermediate regions to close the openings in such regions.
According to another aspect of the invention, gravel prepack equipment for assembly into a gravel prepack to be installed in a hole formed in a fluid bearing formation to prevent sanding during production, comprises a perforated inner tube, a plurality of annular filter elements adapted to be slid onto the inner tube, and a plurality of spacers adapted to be slid onto the inner tube for spacing the filter elements longitudinally along the inner tube.
According to a further aspect of the invention, a method of assembling a gravel prepack to be installed in a hole formed in a fluid bearing formation to prevent sanding during production, comprises the steps of stringing a plurality of annular filter elements onto an inner tube alternately with spacers operative to space the filter elements longitudinally along the inner tube, and then securing the string of filter elements and spacers against longitudinal movement along the inner tube. The securing step preferably includes securing stops to the inner tube at opposite ends of the string of filter elements and spacers, and preferably at least one of the stops is secured to the inner tube by screwing the stop onto a threaded portion of the inner tube.
The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings:
FIG. 1 is a side elevational view, partly broken away in cross-section, of a gravel prepack according to the invention;
FIG. 2 is an enlarged side elevational view of one of the gravel pack elements employed in the assembly of FIG. 1;
FIG. 3 is a transverse cross-sectional view through the gravel pack element of FIG. 2 taken substantially along the line 3--3 of FIG. 2;
FIG. 4 is a schematic illustration of the gravel prepack traversing a dog-leg in an inclined well bore; and
FIG. 5 is a schematic illustration of the gravel prepack installed in a subterranean producing formation.
DETAILED DESCRIPTION
Referring now in detail to the drawings and initially to FIG. 1, a gravel prepack according to the invention is indicated generally at 10. The gravel prepack 10 comprises a plurality of gravel pack elements 12 carried on an inner tube 14. As is preferred, the gravel pack elements 12 (also herein referred to as donuts) are strung onto the inner tube and are maintained axially spaced apart along the length of the inner tube by spacers 16. The alternating gravel pack elements and spacers are held together in end-to-end butted relationship by and between stop collars 18 and 20. Although any suitable means may be employed to mount the stop collars to the inner tube, preferably the stop collars are internally threaded for screwing onto externally threaded end portions 24 and 26 of the inner tube. The externally threaded end portions 24 and 26 also provide for connection of the inner tube 14 to other components of a production string. At the left in FIG. 1, there is shown a conventional internally threaded coupling 28 which may be used to connect the adjacent end of the inner tube to the end of an adjacent liner section in a production string.
With additional reference to FIGS. 2 and 3, each gravel pack element 12 includes inner and outer screens 32 and 34 which extend between end caps 36 and 38. The inner and outer screens 32 and 34 are radially spaced apart and the end caps 36 and 38 are axially spaced apart to form a containment chamber 40 for filtering media and, more particularly, gravel 42. For purposes of this description, the term "gravel" is intended to encompass any granular or aggregate material used for filtering purposes in subterranean wells to control the amount of sand produced with the fluid being recovered from the subterranean formation, be it oil, gas, water or other fluid. As used herein, the term "sand" is intended to encompass sand and other fine solids that may be produced with oil, gas or water in a subterranean well.
The inner and outer screens 32 and 34 preferably are concentric to give the annular chamber 40 a cylindrical shape of uniform radial thickness. The inner and outer screens may be of any suitable type such as, for example, a perforated tube or a wire wrapped screen. Continuous slot, welded wire screens may be obtained from Johnson Screens of Scott, La. As shown, the ends of the screens are welded to the end caps 36 and 38 to form a unitary structure, although other suitable means such as support rods may be employed to hold together as a unit the components of the gravel pack element 12.
In the illustrated embodiment, the end caps 36 and 38 are in the form of annular flange plates or rings having an inner diameter sized to fit over the outer diameter of the inner tube 14. Preferably the rings 36 and 38 are sized to provide a close fit on the inner tube to preclude any significant passage of production fluids between the end caps and the inner tube. The inner screen 32 also has an inner diameter sized to fit over the inner tube. If desired, the inner screen may be spaced radially outwardly from the outer surface of the inner tube to form spaces for collection of filtered production fluid as may be desired to promote flow. The gravel retained between the screens may be loose or consolidated. In the latter case, at least one of the screens 32 and 34 and particularly the inner screen may be omitted, although usually both screens will be desired to maintain the integrity of the gravel pack element.
The above described gravel pack element 12 is generally of conventional construction apart from its assembly on the inner tube 14. In contrast to conventional gravel prepacks, plural gravel pack elements 12 are carried on the inner tube 14 and each gravel pack element is less than and preferably much less than one-half the length of the inner tube. The length of the gravel pack element preferably is less than four times the inner diameter of the inner tube and more preferably is less than about three times the inner diameter of the inner tube. Also, the inner tube preferably has a diameter less than the liner tube of common conventional gravel prepacks while the outer diameter of the gravel pack elements may be the same as that employed in common conventional gravel prepacks. The smaller diameter inner tube 14 provides for increased flexibility to facilitate flexing and traversing of severe dog-legs in a well. Preferably, the ratio of outer diameter of the gravel pack element to the inner diameter of the inner tube is greater than 2.75:1 and more preferably equal to or greater than about 3:1 for a four inch outer diameter gravel pack element. For a six inch outer diameter gravel pack element, a preferred and more preferable ratio of outer diameter of the gravel pack element to the inner diameter of the inner tube are 2.25:1 and 2.5:1, respectively. For other diameters the preferred and more preferred ratios may be extrapolated from the foregoing ratios given for four inch and six inch outer diameter gravel pack elements.
The gravel pack elements 12 are mounted on the inner tube 14 for relative movement during flexing of the inner tube. In the illustrated embodiment, this is obtained by spacing the gravel pack elements axially apart along the length of the inner tube. As a result, the gravel pack elements can freely shift angularly with respect to one another during flexing of the inner tube, i.e., without interfering contact between adjacent gravel pack elements. Moreover, the segments of the inner tube between the gravel pack elements are more free to flex or bend than the portions of the inner tube that are surrounded by the gravel pack elements which are relatively rigid or stiff. These intermediate segments of the reduced diameter inner tube provide for increased flexibility of the overall assembly thereby to enable traversal of even ultra-short radius wells. As used herein, an "ultra-short radius" is 20 degrees/foot to 30 degrees/foot, a "short radius" is 1 degree/foot to 3 degrees/foot, a "medium radius" is 9 degrees/100 feet to 45 degrees/100 feet and a "long radius" is 1 degree/100 feet to 8 degrees/100 feet. The intermediate segments of the inner tube preferably are of a length equal to or greater than the outer diameter of the inner tube to provide sufficient length for flexing to allow the relatively rigid filter elements to align tangentially to a curved section of a borehole.
The gravel pack elements 12 may be fixedly secured to the inner tube 14 as by welding of the end flanges or caps 36 and 38 to the inner tube. In such case the inner screen may be omitted by relying on the inner tube to contain the filtering media 42 as may be necessary if a loose aggregate filtering media is employed. The spacers 16 and stop collars 18 and 20 may also be omitted if the end caps are welded to the inner tube. The inner tube is perforated as by round holes or slits 48 in the regions circumscribed by the gravel pack elements to allow for passage of oil, gas or water through the gravel pack element and into the interior of the inner tube for flow through the production string to the surface.
Although the gravel pack elements 12 may be relatively permanently secured by welding to the inner tube 14 as above mentioned, preferably the gravel pack elements are strung onto the inner tube along with the spacers 16 which serve to maintain the spacing between adjacent gravel pack elements. As previously indicated, the string of alternating gravel pack elements 12 and spacers 16 is held together and in place on the inner tube by and between the stop collars 18 and 20.
The spacers 16 preferably closely surround the inner tube 14 to enable use of an inner tube which is substantially continuously perforated over an extent thereof normally spanning multiple gravel pack elements 12 and more preferably substantially from end-to-end. If the inner tube has perforations 48 substantially throughout its entire length or over a substantial portion thereof, the spacers additionally function to close the perforations in the segments of the inner tube located between the gravel pack elements.
As will be appreciated, the gravel pack elements 12 may be pre-made and stored until needed. When a gravel prepack is needed, the gravel pack elements may be assembled along with the spacers onto a perforated inner tube of selected length. In this manner, the gravel prepack may be configured on site to the particular application. For example, the spacing between gravel pack elements may be varied by using one or more spacers between adjacent elements or by cutting the spacers. Also, different lengths of gravel pack elements may be provided and assembled onto the inner tube to obtain a desired configuration, although gravel pack elements of the same length would normally be sufficient and advantageous by minimizing the number of different gravel pack elements that need to be stored. The gravel pack elements may also vary in outside diameter for use with production casings of different diameters. The gravel pack elements may also be butted end-to-end as may be desired in long radius wells to provide for increased production capacity per length of pipe. On the other hand, shorter gravel pack elements with greater spacing therebetween may be desired for use with short and ultra-short radius dog-legs. As will be appreciated, the use of interchangeable parts including the sleeves and gravel pack elements greatly facilitates the servicing and customizing of a gravel prepack to a particular application. The present invention provides for superior application flexibility.
The spacers 16 in the illustrated embodiment are metal sleeves. However, other types of spacers may be used such as rubber sleeves or boots. Of course, the material of the spacer, as well as the materials of the other components employed in the gravel prepack 10, should be capable of withstanding environmental conditions encountered downhole.
The assembled gravel prepack 10 may be connected to the end of a tubing string and fed in conventional manner into a bore hole which may include a dog-leg. FIG. 4 schematically shows a gravel prepack 10 traversing a dog-leg in an inclined well bore 50. The well bore contains a well casing 52 which extends through the well and is held in place by cement 54. As shown, the inner tube 14 flexes intermediate the gravel pack elements 12 to allow the gravel pack elements to rotate with respect to one another for passage through the dog-leg. The leading end of the gravel prepack is closed by a bull plug 56.
In FIG. 5 the gravel prepack is shown installed in the subterranean producing formation. The well casing 52 is provided with perforations 58 in the producing zone. If desired, the annular space 60 between the gravel prepack and the casing 52 may be packed with gravel using conventional gravel packing techniques. However, the gravel prepack normally eliminates the need to rely on pumping and placing sand in a horizontal or high angle application such as is done in conventional gravel packs.
Gravel pack devices according to the invention will have particular application in wells with sand control problems coupled with high dog-leg severity and/or high angle or horizontal completions.
|
A gravel prepack production system characterized by a flexible gravel prepack comprising an inner tube and a plurality of discrete annular filter elements carried on the inner tube and longitudinally spaced therealong by spacers. The tube is free to flex at the segments thereof intermediate the relatively rigid filter elements to enable the gravel prepack to traverse even severe doglegs in the well. The filter elements and spacers may be strung onto the inner tube at the production site to configure the gravel prepack to the particular application as by selecting a desired spacing between the filter elements.
| 4
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention describes a method of saving power in an implantable device, such as a pacemaker, which includes RF telemetry functionality.
2. Description of Related Art
Since the allocation of a special frequency band for implantable medical devices using RF telemetry, the so-called MICS (Medical Implantable Communication Service) band, by FCC in the late 1990's, the development of devices including this functionality has really taken off. However, since the battery capacity in an implantable device is very limited, the introduction of a RF transceiver operating at 402-405 MHz becomes a real challenge. If the transceiver operates at 5 mA in the active mode, this might be acceptable since in the normal user scenario the on-time is only a fraction (<0.01%) of the total device life time. A trickier problem is the issue of waking up the RF component from the off state to start communications in a reasonable amount of time without draining the battery.
The most common method of solving this problem today is to introduce the so-called sniff mode. This means that the complete receiver RF portion of the device is turned on for a limited period of time (e.g. 10 milliseconds) during which time the device listens to see if there are any transmitters active in the vicinity wanting to make contact. By duty cycling the on (sniff) time heavily with the off time a considerable power saving can be achieved. For example having the device on for 5 ms consuming 5 mA and then off for 995 ms while consuming only leakage current of maybe 100 nA will lower the average current consumption to only about 25 μA. This is very good in most applications. However, for an implantable device consuming less than 10 μA in total this is unacceptable. Lowering the average power consumption further by decreasing the on time is difficult since a certain time is needed to start up the RF receiver and to receive a message telling the device to start transmitting a response. Increasing the off time is not preferred since the doctor who is trying to get in contact with the device expects a response within a second or two.
An example of the prior art is found in U.S. Pat. No. 4,519,401 issued May 28, 1985.
SUMMARY OF THE INVENTION
According to the present invention there is provided an implantable electronic device, comprising a first radio receiver for receiving telemetry data, said first radio receiver having a wake mode and a sleep mode, and being configured to be in said sleep mode unless woken up by a triggering event; a second radio receiver with very low power consumption compared to said first radio receiver; a control unit coupled to the second radio receiver for periodically turning on the second radio receiver during a listen window to listen for an incoming radio frequency signal indicating an external device wishes to establish contact; an analyzer forming part of the second radio receiver for verifying the properties of an incoming radio signal, said analyzer, in response to receipt of said incoming radio frequency signal, prolonging the listening window to enable reception of a full wake-up message, wherein the prolongation of the listen window is sustained only as long as the properties of the incoming wake-up message match a correct message ; and said analyzer further being configured to place said first radio receiver in the wake mode to receive incoming telemetry data in response to the detection of a full correct wake-up message by the second radio receiver.
The first radio receiver normally forms part of a transceiver for exchanging two-way telemetry data with an external device.
Thus, in accordance with the invention, an implantable device with an RF telemetry transceiver has a separate low power receiver to wake-up the device to save power when an external RF unit wishes to communicate with the implanted device. The normal RF telemetry transceiver is turned off for most of the time except when there is an active telemetry link in operation.
The low power receiver has a simplified architecture to drive down the power consumption to about 200 μA and operates as a wake-up device for the full RF transceiver. Because of the simplicity of the low power receiver it can also be turned on very quickly (less than 200 μs).
For most of the time all the RF functionality in the implantable device is switched off and consumes less than 100 nA of leakage current. Every 1 second the lower power receiver is turned on by the application circuitry for about 0.5 ms to listen to see if there are any outside devices trying to get in contact. If an appropriate signal is received, the listen window is prolonged to enable the reception of a full wake-up message and trigger the turn on of the full-blown MICS transceiver, which starts to transmit and receive. The prolongation of the wake-up receiver's reception window is only sustained as long as the properties of the received message match a correct message. One example of such a property is to use so called Manchester encoding and to turn off the low power receiver as soon as any non-Manchester encoded signal is detected. This leads to additional power saving since the wake-up receiver is turned off immediately as soon as it becomes clear that the message is incorrect instead of receiving a complete wake-up message before checking if the message is correct or not.
With a power consumption of 200 μA from the low power receiver this will give a total average power consumption of 200 nA (100 nA leakage and 100 nA from the low power receiver).
In accordance with another aspect the invention provides a method of saving power in an implantable electronic device having a first radio receiver for receiving telemetry data, said first radio receiver having a wake mode and a sleep mode, and being configured to be normally in said sleep mode, said method comprising periodically listening in a sniff mode for a wake-up signal with a second radio receiver that has very low power consumption compared to said first radio receiver; in response to reception of part of a wake-up signal by said second radio receiver prolonging the sniff mode while the received part of a wake-up signal remains valid until a complete wake-up signal is received; and in response to a complete valid wake-up signal, placing said first radio receiver in the wake mode to receive incoming telemetry data.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:—
FIG. 1 is a block diagram of an implantable device in accordance with one embodiment of the invention; and
FIG. 2 is a more detailed block diagram of an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the simplified receiver comprises an antenna 1 receiving a wake-up signal (common with the MICS band antenna or separate), an amplifier 2 which amplifies the signal, and a comparator/detector 3 that detects the amplified signal if it is above a certain power level.
To further increase the security of the receiver against the device being woken up by noise, the wake-up signal comprises a predetermined coded pattern, which is analyzed in an analyzer 4 to see if it matches the wake-up pattern. Only if the pattern is correct the full transceiver 5 will be turned on by the analyzer 4 . The amplifier 2 , comparator 3 and analyzer 4 form part of a simple very low power receiver 20 , which is periodically turned on during a sniff period to listen for an incoming radio frequency signal by a control unit 21 .
FIG. 2 shows another embodiment where an RF signal is received by a tuned antenna 6 connected to an amplifier 7 , an optional band pass filter 8 , which in turn is connected to a rectifier 9 , connected to a comparator 10 , which is connected to an analyzer 11 . The analyzer 11 is connected to the full high power RF transceiver 12 . The amplifier 7 , the band pass filter 8 , the rectifier 9 , the comparator 10 form part of a simple low power RF receiver circuit 13 . The control block 15 controls the turning on and turning off of the low power receiver 13 .
The full transceiver may use the same antenna as the low power receiver as shown in FIG. 1 or may use a separate antenna as shown in FIG. 2 with antenna 14 shown as a separate entity.
The incoming RF signal picked up by the antenna 6 is fed into the simple receiver circuit 13 . The described solution uses a Manchester encoded On/Off Keying (OOK) modulation scheme, but other modulation schemes such as Frequency Shift Keying (FSK), Phase Shift Keying (PSK), etc. can also be envisioned for those skilled in the art.
The signal picked up by the antenna is amplified by the amplifier 7 , fed into the low power band-pass filter 8 that filters the signal around the chosen wake-up frequency, in or outside the MICS band. The filtered signal is then fed into the rectifier 9 and connected to the comparator 10 as a much lower frequency signal. The comparator 10 acts as a decoder that decodes the incoming RF-signal (if any), and if the level is above the comparators threshold, which can be made programmable, starts to convert the signal into logical ones ‘1’ and zeros ‘0’. The digital signal from the comparator 10 is fed into an analyzer 11 where it checked to see if it is a Manchester encoded signal and if so is compared to a predetermined digital signal pattern and if the incoming signal matches this pattern the analyzer turns on the full RF transceiver, which starts the full RF transmission. If there is no matching Manchester encoded signal detected within the 0.5 ms window the device just goes back to sleep until the next 0.5 ms on time 995.5 ms later.
For greater noise immunity it is an preferable to code the incoming signal using a more sophisticated scheme than one where the presence of signal represents a ‘1’ and absence of signal represents a ‘0’. Examples include pulse width modulation (PWM) where a long presence of a signal in a time slot represents a ‘1’ and a short presence represents a ‘0’. Alternatively the signal may be amplitude modulated using Pulse Position Modulation (PPM) or Pulse Amplitude Modulation (PAM), provided a suitable analyzer 14 is used.
An additional level of security can be achieved by letting the detection of the correct signal within the first 5 ms trigger a prolongation of the low power receiver to allow a longer coding pattern to be used before turning on the full transceiver. In this embodiment the prolongation only continues as long as the received pattern is Manchester code and thus matches the expected properties. However, those skilled in the art will appreciate that the said expected properties can mean any coding pattern as well as the correct pulse width, correct pulse position, correct frequency, correct pulse amplitude etc. This is done even before the digital wake-up message is decoded given the possibility of immediately going back to sleep as soon as the incoming message has the incorrect properties.
The simplicity of the receiver 13 makes it very difficult to achieve very good receiver sensitivity. In order to attain a reasonable wake-up range it can be advantageous to use another frequency band than the MICS band, which is very limited in the allowed output power (maximum 25 μW). Examples of such frequency bands that can be used are the ISM band at 2.45 GHz, the US ISM band at 902-928 MHz, the Short Range devices band at 868 MHz in Europe. These bands all have a much higher power limit than the MICS band.
The described circuitry lends itself to integration in a single chip, for example, using CMOS technology.
It will be appreciated by one skilled in the art that the above description represents an exemplary embodiment, and that many variants within the scope of the appended claims are possible without departing from the scope of the invention.
|
An electronic implantable device with a power saving circuit incorporates a radio frequency receiver with high power consumption. The first power radio receiver of high power is normally turned off during a period of inactivity. When an analyzer forming part of a second radio receiver and coupled to the first radio receiver detects a predetermined identification code in a received radio frequency signal received by the second radio receiver, it outputs a signal to turn on the first power receiver.
| 0
|
BACKGROUND OF THE INVENTION
In apparatus for removing coke from an inclined wharf using a roll disposed at the discharge end of the wharf for transferring the coke on to a horizontal conveyor which is provided parallel to the wharf at the discharge end it is known that the wharf has a row of retaining grates which are disposed at the discharge end above the wharf, which are individually opened in order to allow a desired amount of coke to slide at a determined point on to the conveyor belt. In order to ensure a uniform transfer it is known to arrange at the free end of the wharf a roll which rotates continuously and thus directs the coke on to the conveyor belt. In addition to the use of a roll having a smooth, closed surface, it is also known to provide on the surface of the roll chambers which are formed by radial ribs. The chambers can even extend as far as the shaft so that a bucket wheel results. The chambers in the form of segments or sectors are completely open externally so that the roll equalizes the coke flow approximately in the manner of an impeller, said flow being released by the retaining grates. The constructional expenditure for these retaining grates is considerable, in particular if the labour force for operating the retaining grates is replaced by automatic control systems.
SUMMARY OF THE INVENTION
This invention relates to an apparatus comprising a rotatably mounted roll which is provided with a circumferential shell enclosing a chamber within the cavity of said hollow roll, said chamber having a peripheral aperture provided in said circumferential shell and extending longitudinally over the entire length of said roll but only over a small portion of the periphery of said chamber. It is the object of the invention to make possible a uniform and controllable removal of coke from the wharf without the necessity of providing retaining grates.
The apparatus in accordance with the invention brings the advantage that the closed circumferential surface acts in the manner of the retaining grates, the peripheral aperture allowing the removal of a certain quantity of coke from the wharf. The hollow roll is advantageously driven continuously, its peripheral velocity being matched to the feed rate of the conveyor belt.
Advantageously the peripheral aperture extends helically over the periphery of the roll so that coke is successively discharged from the wharf at specific points thereon. The coke is then poured after a given period of time on to the conveyor belt. In conformity with the path of the helical peripheral aperture, the discharge points shifts over the entire length of the roll and of the coke wharf, in which case the conveyor belt carries out a relative movement so that from the outset in feed direction the coke deposited on the conveyor belt is immediately conveyed away from the region of the roll. In this way it is additionally possible to control the layer depth of the coke on the conveyor belt. At the same time it is possible to achieve an equalization of the loading of the conveyor belt.
The helical peripheral aperture, which extends approximately over an arc of 10 to 20 percent of the entire periphery of the chamber, extends advantageously only over a zone of about 270°, so that the circumferential surface of the shell is fully closed over the remaining zone. In this way the discharge of coke from the inclined wharf on to the conveyor belt can be completely interrupted temporarily.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows diagrammatically a cross-section through a coke wharf, a hollow roll and the conveyor;
FIG. 2 shows the development of the circumferential surface of the hollow roll and
FIGS. 3 to 5 show further examples of embodiment for the hollow roll.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An inclined wharf 10 is supported on columns 11 and has a sloping surface 12 in the form of a grating for receiving the extinguished coke. At the lower free or discharge end 13 there is mounted a hollow roll 14 which extends along the entire length of the inclined wharf 10. The hollow roll 14 has a circumferential shell 15 with a smooth exterior surface, to which there is assigned a correspondingly concave-shaped surface 16 at the discharge end 13 of the inclined wharf 10. The hollow roll 14 has at its free ends bearings and drive means (not shown) which impart rotational drive to the hollow roll 14 in the direction of the arrow 17.
The circumferential shell 15 of the hollow roll 14 has a longitudinally extending peripheral aperture 18 which is essentially of slot-type configuration, i.e. extends over a small portion of the periphery of the chamber 19 located inside the roll 14. Advantageously, the peripheral aperture 18 reaches over an arc of between 10 to 20 percent of the entire periphery of the chamber 19, whilst the remainder of the periphery is formed by the closed circumferential shell 15.
In the position of the hollow roll 14 shown in FIG. 1, coke arrives in the chamber 19 from the surface 12 through the aperture 18. The gap between the surface of the shell 15 and the surface 16 is in this case so chosen that at the prevailing grain size of coke no material can pass through the gap. The coke enters the aperture 18 as soon as the leading edge 20 of the aperture 18 is situated somewhat above the extension of the surface 12. The coke discharge is interrupted as soon as the trailing edge 21 reaches the extension of the surface 12. The smooth closed surface of the circumferential shell 15 adjoining the trailing edge 21 then acts as a retaining wall for the following coke load.
The coke remains in the chamber 19 until the leading edge 20 of the aperture 18 has reached a position above a conveyor belt 22, in which the coke pours out of the chamber 19. The discharge proceeds until all the coke is emptied from the chamber 19 on to the conveyor belt 22. This condition is reached when the trailing edge 21 (see FIG. 1) is located approximately above the right-hand side of the conveyor belt 22. From this position on no coke is delivered on to the conveyor belt 22 so that said belt runs past the inclined wharf 10 until the end of the coke layer reaches the front end of the inclined wharf 10. During this phase the hollow roll 14 continues its rotation so that the filled chamber 19 is again emptied, as soon as an empty stretch of conveyor belt arrives beneath the roll 14.
The conveyor is shown highly schematized as a conveyor belt 22 which in the practical embodiment is provided with a trough for accomodating the coke. Other endless conveyors are also suitable.
Whereas previously a straight peripheral aperture 18 has been described, which runs parallel to the axis of the hollow roll 14, it is particularly advantageous to arrange the peripheral aperture 18 helically, as evident from FIG. 2. Here there is shown a development of the circumferential shell 15 of the hollow roll 14. The helical peripheral aperture 18 extends only over a zone of about 270° of the roll 14, whereas a portion 23 of about 90° is closed. The helical peripheral aperture 18 is so arranged that, taking into consideration the direction of rotation 17, the leading edge 20 at the front free end 24 firstly reaches the extension of the surface 12. The filling of the chamber 19 therefore takes place from the front free end 24 in the direction of the rear free end 25 of the hollow roll 14. If, subsequently, the peripheral aperture 18 has turned through an angle of about 180° in the rotational direction 17, then somewhat more than the front half of the chamber 19 is filled with coke and there commences in the region of the front free end 24 of the roll 14 the discharge on to the conveyor belt 22, which is moving in the direction of the arrow 22', according to FIG. 2. Immediately after discharge, the coke situated on the conveyor belt 22 leaves the zone of the hollow roll 14 and the discharge site shifts from the end 24 towards the end 25, depending on the rotational velocity of the hollow roll 14. Subsequently, there follows the portion 23, in which the discharge of coke is interrupted, and the end of the coke layer is conveyed from the rear end 25 to the front end 24 of the roll 14. The feed rate of the conveyor belt 22 and the rotational velocity of the roll 14 are so co-ordinated with one another that as soon as the end of the coke layer reaches the front end 24, coke is again discharged in the vicinity of the end 24 over the leading edge 20 through the peripheral aperture 18.
The helical arrangement of the peripheral aperture 18 ensures uniform depositing of the coke on the conveyor belt 22. The transferred quantity of coke can be controlled practically infinitely variably, by synchronizing the drives of the roll 14 and of the conveyor belt 22 with one another.
If the hollow roll 14 is brought to a halt when the portion 23 is flush with the surface 12, then no coke can slide down, the chamber 19 is empty and the conveyor belt is likewise unladen.
The hollow roll shown in FIG. 1 has a chamber 19 which corresponds to the entire free interior cavity of the hollow roll 14. If a chamber 19 of such size is not required then, according to FIG. 3, it is possible to provide a false floor 26. The chamber 19 then corresponds to half the volume of the hollow roll 14, whereas a space 27 always remains free. In the case of a helical peripheral aperture 18, the false floor 26 is correspondingly twisted, as indicated in FIG. 3.
If a larger chamber 19 is desired then, according to FIG. 4, a smaller closed space 27 can be formed by false floors 26. Here too, the false floors 26 are twisted in conformity with the path of the helical peripheral aperture 18.
The false floor 26 is advantageously set back in relation to the trailing edge 21 (FIG. 3) in order to prevent coke which is entering the aperture 18 from the surface 12 from penetrating into the gap between the surface of the circumferential shell 15 and the surface 16. However, the false floor 26 causes the coke to be poured immediately rearwards into the chamber 19, so that it could also be advantageous to adjoin the false floor 26 immediately against the trailing edge 21, as shown in FIG. 4. This embodiment represents simultaneously an improved protection for the heavily stressed trailing edge 21, when this latter has to retain the following coke load in conjunction with the circumferential shell 15.
In order to strengthen the hollow roll the circumferential shell 15 can be provided internally with reinforcing rings which, however, do not reduce the free cross-section of the peripheral aperture 18.
The space 27 in the example of embodiment according to FIG. 3 may also be provided as a chamber 19 with a peripheral aperture 18. The two symmetrically arranged chambers 29 then each have one peripheral aperture 18 which extends over 10 to 20 percent of an arc of 180°. It is also possible for two completely closed portions 23 to be provided, which for example then extend through 45°. Such an arrangement can be used when exclusively small grain sizes occur.
Finally, according to FIG. 5, another aperture 18' can be provided diametrically opposite the aperture 18, so that a portion of the coke entering the chamber 19 at 18 immediately leaves again at 18'. The remaining amount of coke then left in the chamber 19 is discharged upon further rotation of the hollow roll 14 so that uniform depositing on the conveyor belt 22 is also achieved in transverse direction. The arrangements in the chamber 19 correspond approximately to those according to FIG. 4.
It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings, but also comprises any modifications within the scope of the appended claims.
|
An apparatus for transferring coke in measured quantities from an inclined wharf on to a horizontal conveyor, which comprises a roll being provided with a circumferential shell enclosing a chamber with a peripheral aperture. The peripheral apeture extends straight or helically over the entire length of the roll. The helical peripheral aperture extends only over a zone of about 270°.
| 2
|
REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT/DE03/02304, which was not published in English, that claims the benefit of the priority date of German Patent Application No. DE 102 31 183.8, filed on Jul. 10, 2002, the contents of which are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an amplifier circuit.
BACKGROUND OF THE INVENTION
[0003] Audio signals are normally amplified using class D amplifiers, inter alia. In line with the underlying principle, a reference signal is first compared with a signal fed back from the output and a corresponding error signal is output. This signal is processed on a pulse width modulation basis using a sawtooth signal and is passed to an output amplifier stage. In this case, the output stage is operated so as to switch at a particular duty ratio. To maintain a flow of current at the output, a freewheeling diode and an inductor are provided at the output. It is thus possible to provide a constant output current at the output.
[0004] FIG. 1 in the “Journal of the Audio Engineering Society”, Audio Engineering Society, New York, USA, vol. 39, No. 9, Sep. 1, 1991, pages 650, 662 shows an amplifier circuit with a differential amplifier whose output side is connected to a first input on a comparator. A second input on the comparator is supplied with a sawtooth-waveform signal. The output side of the comparator is connected to an output circuit which is pulse width modulated.
[0005] Printed document EP 0503571 A1 likewise shows a pulse width modulated amplifier circuit whose signal input is connected to a comparator. A second input on the comparator is supplied with a sawtooth-waveform signal. The output of the comparator is connected to an output stage.
[0006] However, such amplifiers have relatively poor properties in terms of the power supply rejection ratio (PSRR). If the low-level signal response of a circuit of this type is considered, the ratio of the output voltage to the input voltage is
Vout Vin = d 1 + s 2 LC ,
where L and C are the values of an LC filter at the output and d is the duty ratio of the pulse width modulation. The gain of the transfer function Vout/Vin is accordingly proportional to the duty ratio d, which may be between 0 and 1. However, this term determines the denominator of the formula for describing the power supply rejection ratio. Accordingly, fluctuations in the supply voltage or radio-frequency interference components in the supply voltage result in relatively severe unwanted effects on the output signal from the amplifier circuit.
[0007] A further problem of the principle described is the unwanted convolution of signals. If the supply voltage for the output stage behaves like a relatively low-frequency sinusoidal oscillation but the useful signal is likewise a (higher-frequency) sinusoidal oscillation, then the low-level signal gain also varies sinusoidally. The resultant harmonics are at the summed frequency and the differential frequency between the frequencies of the two signals at an amplitude which corresponds to half of the product of the amplitudes of the two signals. The problem is of great significance particularly because the interference may be at frequencies below the cut-off frequency of the low-pass filter at the output and is therefore not filtered out.
[0008] The relatively poor power supply rejection ratio is normally countered by increasing the signal gain. This increases the power consumption, however.
[0009] The convolution problems described may be reduced by reducing the noise components and interference components on the supply voltage, for example by using a linear controller. This severely reduces the efficiency of the amplifier, however.
SUMMARY OF THE INVENTION
[0010] The following presents a simplified summary in order to provide a basic understanding of one or more aspects of the invention. This summary is not an extensive overview of the invention, and is neither intended to identify key or critical elements of the invention, nor to delineate the scope thereof. Rather, the primary purpose of the summary is to present one or more concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
[0011] The present invention is directed to an amplifier circuit which operates on the basis of the class D principle and has an improved power supply rejection ratio.
[0012] In one embodiment of the invention, the amplifier circuit comprises an input for supplying a useful signal which is to be amplified, and an output for tapping off an amplified useful signal. The circuit further comprises a differential amplifier having a first input, which is connected to the input of the amplifier circuit, a second input, which is coupled to the output of the amplifier circuit, and an output. A comparator is also provided having a first input, which is connected to the output of the differential amplifier, and a second input, to which a periodic signal is supplied, along with an output stage having an input, which is connected to an output of the comparator, an output, and having a supply connection for supplying a supply voltage thereto. The circuit also comprises a signal generator which is connected to the second input of the comparator and provides the periodic signal at an amplitude which is proportional to the supply voltage for the output stage. The signal generator is configured in a phase locked loop to regulate the frequency of the periodic signal on the basis of a reference clock.
[0013] In accordance with the present invention, the periodic signal used for pulse width modulation is provided such that its amplitude is always proportional to the supply voltage for the amplifier circuit, particularly for the output stage of the amplifier circuit.
[0014] In accordance with another exemplary embodiment of the invention, the duty ratio is always proportional to the supply voltage.
[0015] In accordance with yet another embodiment of the invention, the transfer function for the output voltage in relation to the supply voltage in consideration of the low-level signal response is ideally 0, in practical terms at least very low, which means that the power supply rejection ratio PSRR is greatly improved.
[0016] The quotient of the supply voltage and the amplitude voltage of the periodic signal is always constant in one example of the present invention. However, this quotient also describes the low-level signal gain, in particular, of the circuit, and the circuit described accordingly always operates at constant gain such that an additional advantage is that no convolution with a harmonic signal component of the supply voltage may arise.
[0017] If the periodic signal, which, in accordance with the present invention, is used for pulse width modulation, is a ramp signal, a triangular-waveform signal or a sawtooth signal, for example, then the proportionality of this signal to the supply voltage relates to the fact that the peak-to-peak voltage of the ramp signal is proportional to the supply voltage.
[0018] The proportionality of the periodic signal to the supply voltage is produced, in one example, using an operational amplifier whose input side is connected to the supply voltage and whose output side is coupled to the signal generator in order to feed it.
[0019] So that the frequency of the periodic signal always remains constant despite the amplitude of the signal being linked to a possibly fluctuating supply voltage, there is advantageously provided a phase locked loop which ensures that the signal generator's frequency is constant.
[0020] The amplifier circuit described in one example is preferably of symmetrical design with two output stages which are each preferably in the form of inverters. The output nodes of the inverters are each preferably coupled to the output terminals of the output of the amplifier circuit via a series inductor. A stabilization capacitance is preferably connected between the two output terminals.
[0021] In one alternative, a digital implementation of the present invention is contemplated, wherein provision is made for the duty ratio always to be set proportionally to the supply voltage.
[0022] To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects and implementations of the invention. These are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention is explained below using an exemplary embodiment with reference to the figure.
[0024] FIG. 1 is a block diagram illustrating an amplifier circuit according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 shows an amplifier circuit based on the present invention using a block diagram. This circuit comprises an input 1 for supplying a useful signal to be amplified which is in the form of a symmetrical input with a pair of differential input terminals. The signal amplified using the present amplifier circuit, which signal is derived from the signal applied to the input 1 , can be tapped off at the output 2 , which is likewise symmetrically in the form of a pair of output terminals.
[0026] The input 1 has an amplifier 3 connected to it which forms a differential signal from the signal difference between the signal applied to the input 1 and the signal provided at the output 2 . This differential signal is provided at the symmetrical input of the operational amplifier 3 . For this, the pair of output terminals 2 is connected to the input of the amplifier 3 via a respective resistor 4 , 5 . In addition, the two output terminals of the operational amplifier 3 are connected to the two inputs of the amplifier 3 in an inverting feedback loop via a respective capacitor 6 , 7 . In addition to the differential input and the differential output, the amplifier 3 also has a common-mode input for supplying a common-mode level V cm . A common-mode signal may be supplied to this common-mode input.
[0027] Connected to one of the two output terminals of the differential amplifier 3 is the positive input of a comparator 8 , whose negative input is connected to a signal generator 9 . The output of the comparator 8 designed for pulse width modulation PWM is connected to a first output driver 10 l directly and to a second output driver 11 via an inverter 12 . The output drivers 10 , 11 are respectively connected to the control inputs of a CMOS inverter 13 , 14 . The CMOS inverters 13 , 14 each comprise a load-side series circuit comprising a p-channel MOS transistor and an n-channel MOS transistor which are connected between a supply potential connection 15 and a reference potential connection 16 , as is usual for CMOS inverters. The outputs of the CMOS inverters 13 , 14 , which form the output stages of the present amplifier, each have their output node at the connecting node for the MOS transistors. These output nodes are connected to the output terminals 2 via a respective series inductor 17 , 18 . Connected between the output terminals 2 is a stabilization capacitance 19 which forms an LC filter together with the series inductors 17 , 18 .
[0028] The signal generator 9 is in the form of a triangular-waveform signal generator which provides a periodic signal having a peak-to-peak voltage V max -V min at an output 20 , said voltage being obtained from the difference between an upper peak value V max and a lower peak valve V min .
[0029] The frequency (conditioned as a digital clock signal) of the periodic signal provided by the signal generator is provided at a digital clock output 21 which is connected to a first input on a phase detector 22 . A further input on the phase detector 22 is connected to a reference clock source 23 . The output of the phase detector 22 , which provides any phase error between the two input signals, is routed via a voltage/current converter 24 to the quiescent current input 25 of the signal generator 9 .
[0030] The amplitude V max -V min is set at a symmetrically designed amplitude control input 26 on the signal generator 9 . Connected to this input is the differential output of a further operational amplifier 27 . The negative input of the operational amplifier 27 is connected to reference potential 16 via a resistor 28 . The positive input of the operational amplifier 27 is connected to supply potential connection 15 via a further resistor 29 . In this case, the supply and reference potential connections 15 , 16 match the supply voltage connections 15 , 16 of the output stages 13 , 14 in the amplifier. The operational amplifier 27 likewise has a common-mode input which is connected to the common-mode input of the operational amplifier 3 for the purpose of supplying the common-mode signal V cm . The operational amplifier 27 has a negative feedback loop from the differential output to the differential input via a respective resistor 30 , 31 .
[0031] It can clearly be seen that the peak-to-peak voltage V max -V min of the ramp signal provided by the signal generator 9 is proportional to the supply voltage for the amplifier. The bias current of the signal generator 9 is controlled by a phase locked loop in order to keep the frequency of the periodic signal constant while the peak-to-peak voltage V max -V min changes. When designing the circuit, it is important to remember that the bandwidths of the two control loops, namely that of the amplifier and that of the phase controller, are greater than the cut-off frequency of the low-pass filter.
[0032] The present amplifier circuit significantly improves the linearity of the output stage. A further improvement could be attained, by way of example, by increasing the bandwidth of the open loop gain. With the feed-forward technology presented, there is no need for error compensation for any interference components on the supply voltage.
[0033] As already explained, the principle described, namely the setting of the peak-to-peak voltage of the periodic signal proportionally to the supply voltage, allows a significant improvement in the power supply rejection ratio and at the same time makes it possible to avoid unwanted convolution effects to a large extent. In this case, the principle described can be implemented using particularly simple circuit means and with little complexity.
[0034] Instead of the illustrated analog actuation of the reference signal generator 9 with the aim of keeping the duty ratio constant regardless of the supply voltage, a digital implementation may also be provided. For this, the supply voltage would be converted into a digital voltage signal using an analog/digital converter, and the duty ratio of the pulse width modulation would be tracked proportionally to the supply voltage.
[0035] While the invention has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “including”, “includes”; “having”, “has”, “with”, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.
|
The invention is directed to an amplifier circuit based on the principle of a class D amplifier. To avoid unwanted convolution effects and to improve the power supply rejection ratio, provision is made for the amplitude of the ramp signal used for pulse width modulation to track proportionally the supply voltage for the amplifier circuit. For this purpose, the ramp signal generator has an amplitude control input suitably connected to supply and reference potentials. This ensures a constant duty ratio which is independent of the supply voltage. The present circuit may be used, for example, as a DC/DC converter or as an audio amplifier.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to co-pending Provisional Patent Application No. 61/107,891, filed on Oct. 23, 2008 and entitled “Non-Invasive Blood Pressure Monitoring Device And Method”; that application being incorporated herein, by reference, in its entirety.
BACKGROUND OF THE INVENTION
[0002] a. Field of the Invention
[0003] The present invention relates to a device and method for measuring blood pressure, and more particularly, to a non-invasive device and method for measuring blood pressure utilizing an ultra-sound transducer and a conventional blood pressure cuff.
[0004] b. Description of the Related Art
[0005] Blood Pressure Monitoring is essential in the care of patients during surgery and in the ICU setting. To date there is no reliable method of instantaneously measuring blood pressure in a non-invasive way. The usual method used for non-invasive blood pressure measurement is to use a blood pressure cuff. This is a device consisting of an inflatable cuff connected to an air pump and a pressure transducer. The cuff is applied around a limb, usually the upper arm, and inflated to a pressure above the systolic (highest) pressure; the cuff is slowly deflated and the pressure at which blood first starts to pass through the artery underneath the cuff is recorded. The signal used to ascertain that the cuff has reached systolic pressure is the sound produced by the blood flowing through the underlying artery. This sound is pulsatile and either heard by the examiner via a stethoscope or detected by a machine that performs the operation automatically. When the cuff pressure is between systolic and diastolic (lowest pressure), the blood will flow in an intermittent manner through the artery underneath the cuff and produce a characteristic sound. When the pressure in the cuff reaches diastolic pressure, blood flow will become continuous and the sound will disappear, this signals the examiner that diastolic pressure has been reached. This operation is performed automatically by a machine every 3 minutes in the operating room and can also be performed by the touch of a button at the anesthesiologist's need. The problem with this method is that blood pressure may reach dangerous levels for a significant period of time before there is any evidence that such an event is occurring. Instantaneous and continuous measurement of blood pressure (beat to beat blood pressure monitoring) is available today through an arterial line. This method uses an indwelling catheter placed inside the lumen of an artery which is physically connected to a pressure transducer. Arterial lines are effective but invasive and can lead to serious damage to the tissues downstream to the catheter therefore; they are only used in very special situations such as open heart surgery. Non invasive methods of estimating blood pressure by correlating cuff measurements to mechanical sensing of the actual pulsation of peripheral arteries (usually the radial) by means of stress sensors have been attempted and commercialized but have proven unreliable. The reason for this is the variable thickness of the tissues overlying the small peripheral arteries that are accessible to this method and the fact that the pressure in small peripheral arteries frequently does not correlate well to central arterial pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0006] This invention provides non-invasive continuous (beat-to-beat) measurement of arterial pressure by combining conventional blood pressure cuff measurements, an imaging device, such as ultrasound, to monitor the size, shape and behavior of the underlying artery and a digital processor to create a virtual mechanical model of the artery. Instantaneous beat-to-beat blood pressure is calculated by correlating the model with the anatomical information obtained from the imaging device.
[0007] The invention comprises a blood pressure cuff that is connected to or incorporates an ultrasound transducer/transceiver and is applied around a limb and over a large artery such as the brachial artery at the upper arm. The ultrasound transceiver can be located proximal to the blood pressure cuff, but, in one preferred embodiments, is incorporated into the blood pressure cuff, in communication with the blood pressure cuff. Alternately, in another preferred embodiment, the ultrasound transducer can be removably affixed to the blood pressure cuff, for example, using a hook and loop type fastener, such as is sold under the brand name VELCRO™ Alternately, and less preferably, the ultrasound transceiver can be affixed to the skin of the patient, using an adhesive and/or tape. However, it can be recognized that certain advantages, such as ease of use, are provided by providing the blood pressure cuff and ultrasound transceiver in a single unit (i.e., integrated and/or previously connected together).
[0008] In the instant invention, the ultrasound transceiver of the blood pressure cuff/ultrasound device generates ultrasound waves that travel into the arm and bounce back preferentially from fluid filled structures such as arteries and veins. The signal that returns to the ultrasound transceiver is captured and relayed to a processor, which interprets the information by means of dedicated circuitry. Such information can be relayed to the processor either wirelessly, using the appropriate transmission electronics, or by wired communication. Using the Doppler Effect, the processor determines which vessel is the artery; this is possible due to differences in the velocity and waveform of the flow. The processor then measures and correlates vessel parameters such as cross-sectional area of the artery with blood pressure measurements, as determined by the cuff, to digitally calculate the vessel's mechanical properties, such as compliance, and to create a digital model of the vessel. This model is used by the processor to calculate instantaneous blood pressure based on the anatomical information provided by the transceiver in the intervals between cuff measurements. In other words, the vessel itself is used as a pressure transducer, once its properties have been ascertained. An arterial pressure wave is caused by the pumping action of the heart and, therefore, the measured vessel parameters must be properly timed into this cycle. In one particular embodiment of the instant invention, the timing of the cycle can be achieved by connecting the device's processor an electrocardiogram lead which would signal the ultrasound transceiver when to capture an image.
[0009] During each cycle, the cross-sectional area of the detected artery can be measured at the peak of arterial pressure and a second cross-sectional measurement can be obtained at the trough. Comparing these two with systolic and diastolic pressures will yield the vessel's compliance. Also the instantaneous blood pressure value can be obtained from equation (1), as follows:
[0000] P= 2 πL I (1 −r 0 /r ) (1)
Where:
[0010] P=Pressure;
[0011] L I =Vessel Coefficient of elasticity;
[0012] r 0 =Resting vessel radius; and
[0013] r=Instantaneous vessel radius.
[0014] Velocities of wall expansion as well as wall acceleration are parameters that may also be used to augment the virtual model of vessel behavior. All these measurements are repeated continuously in order to constantly recalibrate the instrument during the period of use.
[0015] The above-described device of the present invention can additionally be used in an inventive method to non-invasively determine the blood pressure of a patient under emergency conditions, such as during surgery, or in while the patient is in an intensive care unit (ICU). For example, the device of the particular invention can be applied to the arm of a patient, with the ultrasound transceiver being located over the patient's brachial artery. In a preferred embodiment of the present invention, wherein the ultrasound transceiver is removably connected to and/or integrated with a blood pressure cuff, the ultrasound transceiver is located proximal to the desired artery by affixing the blood pressure cuff to the upper arm of the patient.
[0016] In one particular embodiment of the present invention, ultrasound readings are taken at a single location along the artery to determine, among other characteristics, the cross-sectional area of the artery at the peak and trough of a cycle. These instantaneous cross-sectional areas of the artery are used to form a rough correlation to instantaneous blood pressure of a patient. For example, a memory device in communication with the processor can store a look-up table correlating each discrete cross-sectional area of the artery to, roughly, an associated, blood pressure. Alternately, known equations can be used to convert the detected cross-sectional areas of the artery to an associated blood pressure. Using such look-up table or equations, the processor is able to determine a surge or pulse that would correlate to an unacceptably high instantaneous blood pressure in the patient. For example, the processor determines whether the rough, instantaneous blood pressure of the patient exceeds a threshold value set by the user and/or by the system software. In response to a determination by the processor that the cross-sectional area(s) of the artery correlates, roughly, to an unacceptably high blood pressure of the patient, the system will trigger the operation and inflation of the blood pressure cuff, in order to obtain a more accurate blood pressure reading for the patient. If the blood pressure for the patient measured by the blood pressure cuff additionally indicates an unacceptably high blood pressure of the patient (i.e., exceeding a preset threshold), an alarm is triggered. Such alarm can be provided locally to the patient, on electrical monitors and biometric readout displays (i.e., in the operating room or ICU), and remotely, for example, at a remote nurses' station and/or doctor's area. Such alarm informs the patient's caretaker of a change in the patient's status so that corrective action can be taken.
[0017] Additionally, in one preferred embodiment of the present invention, software in communication with the processor can determine the compliance of the measured artery, as discussed above. Such software can be used to determine how “sick” is the selected artery. Using the information regarding the condition and elasticity of the artery, the system can be adjusted to each individual patient.
[0018] For example, depending on the elasticity of the artery, a user of the system, or the software itself, could set and/or adjust the parameters necessary for triggering the operation of the blood pressure cuff. Additionally, in one particular embodiment, using the information regarding the elasticity or “sickness” of the measured artery, the system could adjust what values of cross-sectional area of the artery correspond to which blood pressures in this particular patient. Then, the system could trigger the operation of the blood pressure cuff, and subsequently, the alarm, when the cross-sectional area of the artery of the particular patient correlates to an unacceptably high blood pressure, wherein such determination takes into account the actual characteristics of each patient's artery. For example, in one particular embodiment of the system of the instant invention, the system can be programmed to trigger the operation of the blood pressure cuff when the cross-sectional area of the artery of the particular patient (i.e., factoring the elasticity of this patient's artery) correlates to a blood pressure of 200 systolic/120 diastolic, or higher. Alternately, the amount of change in cross-sectional area from the peak measurement of the trough measurement of the cycle, adjusted for the individual characteristics of each patient's artery, can be used to trigger the operation of the blood pressure cuff.
[0019] In one particular embodiment of the instant invention, in a patient having ideal artery characteristics, a pulse or surge that results in a change of cross-sectional measurement of 30% or more, between two cycles of peak measurements and/or trough measurements, could trigger the operation of the blood pressure cuff and, resultantly, of an alarm. However, other factors and/or amounts of change can be pre-programmed into the system, for triggering the operation of the blood pressure cuff.
[0020] In summary, the instant invention includes a combined ultrasound transceiver/blood pressure cuff device and system for roughly determining, through ultrasound information obtained at a particular (i.e., single) location along the patient's artery, significant changes in the arterial cross-section, and correspondingly, in the blood pressure of a patient. Upon determination of a significant change, a more accurate blood pressure reading can be taken with the blood pressure cuff. Confirmation of an unacceptably high blood pressure reading from the blood pressure cuff can be, resultantly signaled to the patient's caregiver. The determination of what amount constitutes a “significant change” can be determined for each patient using characteristics of that patient's artery, as obtained from the received ultrasound information. As such, the trigger points of the system can be tailored to the personal characteristics of each individual patient.
|
A device and method for measuring blood pressure are provided. More particularly, a non-invasive device utilizing an ultra-sound transducer and a conventional blood pressure cuff are used, in combination, to measure blood pressure.
| 0
|
FIELD OF THE INVENTION
This invention relates generally to coaxial cable isolators and particularly to coaxial cable isolators for use in power line voltage applications.
BACKGROUND OF THE INVENTION AND PRIOR ART
Coaxial cable isolators, for providing an interruption or gap in the ground conductor between a user apparatus and an incoming cable ground, are well known in the art. Specifically, U.S. Pat. No. 4,399,419 to P. Dobrovolny and assigned to the assignee of the present invention includes a plurality of disc-shaped ceramic capacitors and ferrites. The capacitive elements had values selected to enable coupling of television signals while blocking direct current and 120 V 60 Hz low frequency power currents. Since the outer ground conductor is interrupted, the isolator is subject to electromagnetic interference (EMI) and the ferrites are used to absorb any such energy that enters the interruption. Coaxial cable isolators of this type have been well received.
The value of the capacitance exhibited by the capacitive elements should be as large as possible to maximize television signal coupling and yet not be so large as to pose safety problems. Also, the isolator ideally should be physically small to enable it to fit into a device, such as an amplifier, and should also exhibit a small capacitance to limit signal leakage, obviously somewhat incompatible requirements. High dielectric constant capacitors, such as those produced from titanate ceramics, have proven useful for such applications. A serious drawback is that the higher the dielectric constant of the titanate formulation, the greater the capacitance temperature coefficient and hence the greater the change in exhibited capacitance with temperature change and the more nonlinear the temperature coefficient is. There has long been a need to obtain a high dielectric constant ceramic formulation that has a minimum temperature dependence. The temperature coefficient of the ceramic is mainly a function of formulation, but is also dependent upon firing temperature.
In the United Kingdom a maximum limit of 5 nonofarads is specified for a 75 ohm coaxial cable isolator. It will be recalled that in the United Kingdom, as in many foreign countries, residential power is supplied at 240 volts rather than at 120 volts as in the United States. Consequently, the capacitance value of the isolator should be lower for safety reasons. Yet, for effective EMI attenuation, the lower limit of capacitance is about 3.8 nanofarad. When the range of environmental temperature to which the isolator is subject, and the large nonlinear temperature coefficient of a high dielectric constant material are considered, many problems are manifest. For a normal outdoor temperature of -15 degrees Centigrade to 40 degrees Centigrade, the capacitance presented by high dielectric constant materials is often too low to provide adequate signal coupling. On the other hand, adding capacitive elements results in too much capacitance at certain temperatures within the operating temperature range of the isolator.
In U.S. Pat. No. 3,549,415 issued to R. Capek and J. Mazintas and assigned to the assignee of the present invention a method of making a multilayer ceramic capacitor is described. In that patent a capacitor includes a plurality of ceramic layers or wafers separated by conductive plates that are alternately connected together to form end leads. The dielectric materials of the wafers are individually selected, based upon their temperature coefficients, to produce a more linear temperature coefficient for the capacitor. That invention involved calcining the thin, flat wafers before sintering to prevent material diffusion between wafers. Diffusion during sintering apparently generated chemical-like reactions that caused substantially different solid solutions, in which the temperature coefficient of the resulting ceramic was no longer related to the ingredient's proportions. The separate precalcining of the ferroelectric wafers precluded diffusion between the layers during sintering.
Thus, the concept of making a multilayer capacitor comprising dielectric materials of different temperature coefficient to achieve a more linear composite temperature coefficient for the capacitor is known. The patented multilayer capacitor was approximately 0.75 inch by 0.1 inch by 0.5 inch and included 6 to 12 layers, with each layer varying from about 0.002 inch to 0.015 inch. An average layer thickness, for low voltage circuits, was about 0.006 inch. The specified temperature range of 25 degrees Centigrade to 120 degrees Centigrade is significantly higher than that under present consideration and no indication of making disc-shaped or tubular capacitors is given.
This prior art method of making a temperature compensated capacitor is difficult and is generally inadequate for use in connection with a tubular coaxial cable isolator, especially one that is subjected to large working voltages, such as 240 volts and to test voltages 1180 volts AC or 2180 volts DC.
OBJECTS OF THE INVENTION
Accordingly, a principal object of the invention is to provide an improved coaxial cable isolator.
Another object of the invention is to provide a small coaxial isolator that provides substantially uniform capacitance for television signal coupling over a substantial temperature range.
SUMMARY OF THE INVENTION
In accordance with the invention, a temperature compensated coaxial cable isolator for couping television signals while blocking low frequency power currents includes an interrupted outer ground conductor. Capacitive television signal coupling means and EMI absorption means are positioned in the interruption. A plurality of individual capacitive elements make up the capacitive television coupling means, with the elements having temperature coefficients selected to exhibit a total capacitance in the range of 3.8 to 5 nanofarads over a temperature range of about 0 degrees Centigrade to +45 degrees Centigrade.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will be apparent upon reading the following description in conjunction with the drawings in which:
FIG. 1 is a cross sectional view of a coaxial cable isolator constructed in accordance with the invention;
FIG. 2 is a perspective view of the capacitive and ferrite elements of the isolator;
FIG. 3 is an electrical diagram of the outer ground conductor; and
FIG. 4 is a set of curves showing the composite capacitance and the individual capacitance exhibited by the capacitive elements.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an isolator 10 including a first outer conductive element 12 of stepped cylindrical configuration, a second outer conductive element 14 and an inner conductive element 16. Second outer conductive element 14 has a threaded end 18, adapted to receive a standard coaxial cable connector, and a small diameter tubular portion 20 and is concentrically arranged with respect to first outer conductive element 12. A large annular insulator 19 is positioned in the gap or interruption between conductive elements 12 and 14. It will be recognized that this gap remains even when a suitable metallic connector is affixed to threaded end 18. Hence the isolator is exposed to EMI. Inner conductive element 16 has a tubular contact tail 28 at one end and a pair of spring contacts 26 at its other end. Contact tail 28 may be adapted to accept an appropriate center conductor from a coaxial cable or to connect to a suitable wire for connection in a circuit. Spring contacts 26 are adapted to resiliently open upon insertion therein of an appropriate mating plug (not shown) for making electrical contact thereto. The spring contacts are confined in an end insulator 24 defining a centrally located aperture 25 of slightly greater diameter than the mating plug. The contact tail of inner conductive element 16 is surrounded by a tubular insulator 30 which concentrically supports inner conductive element 16 in tubular portion 20. The end of contact tail 28 is supported in an end insulator 36 which closes the circular opening in the small diameter end of first outer conductive element 12. The other end of contact tail 28 is supported by an annular insulator 34. In use, this end of outer conductive element 12 is not subject to EMI intrusion.
A tubular-shaped ceramic structure 50 has an inner opening in which tubular portion 20 is supported and an outer surface in contact with the inside of the small diameter end of first outer conductive element 12. Ceramic structure 50 is made up of three disc-shaped capacitive elements 52, 54 and 56 with disc-shaped ferrite elements 58 and 60 sandwiched therebetween. A metal sheath 38 or other suitable conductive element surrounds the outer surface of ceramic structure 50. The inner surface of ceramic structure 50 is preferably metal plated to make it conductive. This is illustrated by metallized area 40. Thus, capacitive elements 52, 54 and 56 are connected in parallel between metal sheath 38 and metallized area 40. The capacitance values of the individual elements are therefore added to arrive at the total capacitance in the interruption of the ground element.
Thus it is seen that the connection of metal sheath 38 to the inner surface of first outer conductive element 12 and the connection of metallized area 40 to the tubular portion 20 of the second outer conductive element 14, electrically connects ceramic structure 50 between the first and second outer conductive elements. As mentioned above, ferrite elements 58 and 60 serve to absorb any EMI which enters the interruption in the outer ground element of the isolator. The open spaces in the isolator may be filled with an epoxy type material indicated by reference numerals 55.
The temperature coefficients of capacitive elements 52, 54 and 56 are selected such that the total capacitance exhibited by the capacitive elements remains within predetermined limits over the operating temperature range of the isolator.
In FIG. 2, the perspective view of ceramic structure 50 clearly shows the arrangement of the disc-shaped capacitive elements 52, 54 and 56 and the sandwiched ferrite elements 58 and 60. A partially cut away view of metal sheath 38 is also shown. The inner metallized area 40 is indicated in the inner opening of ceramic structure 50.
In FIG. 3 the electrical diagram of the interrupted outer conductive element is shown. Specifically, capacitive elements 52, 54 and 56 are connected in parallel between the grounded first and second outer conductive elements 12 and 14, respectively. The EMI absorbing ferrite elements 58 and 60 are shown between the capacitive elements.
The curves of FIG. 4 illustrate the individual capacitance exhibited by capacitive elements 52, 54 and 56, with curve A corresponding to element 52, curve B to element 54, and curve C to element 56. Over the temperature range of interest, namely from 0 degrees Centigrade to +45 degrees Centigrade, the capacitive elements exhibit a substantial variation in capacitance. It will be appreciated that these curves of the capacitance of the capacitive elements will have the same shapes as the curves illustrating the temperature coefficients of the dielectric material of the same capacitive elements because of the linear relationship between dielectric constant and capacitance. These temperature coefficients are selected so that the peak of one of the capacitive elements is at approximately 5 degrees Centigrade, the peak of the other element is at approximately 25 degrees Centigrade and the peak of the third element is at approximately 45 degrees Centigrade. With this selection, the composite capacitance curve D is seen to have a minimum value of about 3.8 nanofarads and a maximum value of about 4.8 nanofarads between 0 degrees Centigrade and 60 degrees Centigrade. Consequently, the ceramic structure constructed with these type capacitive elements will retain sufficient capacitance over the environmental or operating temperature range to enable adequate television signal coupling without exceeding the maximum 5 nanofarads capacitance safety limit established in some foreign countries.
The disc-shaped capacitive element dimensions are 0.183 inch for the inner diameter, 0.324 inch for the outer diameter and 0.115 inch in length. The dimensions of the ferrite elements are not critical.
With the invention, a small tubular-shaped ceramic capacitor structure may be readily fabricated to exhibit a relatively linear temperature coefficient over a substantial temperature range. Further, the ceramic materials are of conventional barium titanate, fired to approximately 2350 degrees Fahrenheit and selected to exhibit peaks in their temperature coefficient characteristic curves at respectively 5 degrees Centigrade, 25 degrees Centigrade and 45 degrees Centigrade. These capacitive elements are readily fabricated and reproducible and enable mass production of temperature compensated coaxial cable isolators which permit adequate television signal coupling over an extreme of temperatures while exhibiting low signal leakage and a maximum capacitance to preclude safety problems, even in areas where 240 volts household power is used.
What has been described is a novel coaxial isolator that is temperature compensated and which solves many of the problems of the prior art. It is recognized that numerous changes in the described embodiments of the invention will be apparent to those skilled in the art without departing from its true spirit. The invention is to be limited only as defined in the claims.
|
A coaxial cable isolator includes a stepped diameter tubular outer conductive element and a threaded smaller diameter inner conductive element coaxially aligned therewith to form an interruption. A ceramic structure is positioned in the interruption and includes three ceramic capacitive elements, each having a different temperature coefficient selected to provide a minimum of 3.8 and maximum of 5.0 nanofarads of capacitance over the 0 degree Centigrade to +45 degree Centigrade operating temperature range of the isolator. Two ferrite elements for EMI absorption are sandwiched between the three capacitive elements.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 566,977, filed Aug. 13, 1990, now abandoned, and application Ser. No. PCT US91/00243, filed Jan. 11, 1991, that in turn is a continuation-in-part of applications Ser. Nos. 463,358, filed Jan. 11, 1990, now abandoned, and the above referenced Ser. No. 566,977, filed Aug. 13, 1990, now abandoned. The entire disclosure of each of these are assigned to the assignee of this application, are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to the design, synthesis and application of nuclease resistant oligonucleotides which are useful for antisense oligonucleotide therapeutics, diagnostics, and research reagents. Sugar modified oligonucleotide which are resistant to nuclease degradation and are capable of modulating the activity of DNA and RNA are provided. Methods for modulating the production of proteins utilizing the modified oligonucleotide of the invention are also provided.
BACKGROUND OF THE INVENTION
It is well known that most of the bodily states in mammals including infectious disease states, are affected by proteins. Such proteins, either acting directly or through their enzymatic functions, contribute in major proportion to many diseases in animals and man.
Classical therapeutics has generally focused upon interactions with such proteins in efforts to moderate their disease causing or disease potentiating functions. Recently however, attempts have been made to moderate the actual production of such proteins by interactions with molecules that direct their synthesis, intracellular RNA. By interfering with the production of proteins, it has been hoped to effect therapeutic results with maximum effect and minimal side effects. One approach for inhibiting specific gene expression is the use of oligonucleotide and oligonucleotide analogs as antisense agents.
Antisense methodology is the complementary hybridization of relatively short oligonucleotides to single-stranded mRNA or single-stranded DNA such that the normal, essential functions of these intracellular nucleic acids are disrupted. Hybridization is the sequence specific hydrogen bonding of oligonucleotides to Watson-Crick base pairs of RNA or single-stranded DNA. Such base pairs are said to be complementary to one another.
The naturally occurring event that provides the disruption of the nucleic acid function, discussed by Cohen in Oligonucleotides: Antisense Inhibitors of Gene Expression, CRC Press, Inc., Boca Raton, Fla. (1989) is thought to be of two types. The first, hybridization arrest, denotes the terminating event in which the oligonucleotide inhibitor binds to the target nucleic acid and thus prevents, by simple steric hindrance, the binding of essential proteins, most often ribosomes, to the nucleic acid. Methyl phosphonate oligonucleotides; P. S. Miller & P. O. P. Ts'O, Anti-Cancer Drug Design, 2:117-128 (1987), and α-anomer oligonucleotides are the two most extensively studied antisense agents which are thought to disrupt nucleic acid function by hybridization arrest.
The second type of terminating event for antisense oligonucleotides involves the enzymatic cleavage of the targeted RNA by intracellular RNase H. The oligonucleotide or oligonucleotide analog, which must be of the deoxyribo type, hybridizes with the targeted RNA and this duplex activates the RNase H enzyme to cleave the RNA strand, thus destroying the normal function of the RNA. Phosphorothioate oligonucleotides are the most prominent example of an antisense agent which operates by this type of antisense terminating event.
Considerable research is being directed to the application of oligonucleotide and oligonucleotide analogs as antisense agents for therapeutic purposes. All applications of oligonucleotides as diagnostic, research reagents, and potential therapeutic agents require that the oligonucleotides or oligonucleotide analogs be synthesized in large quantities, be transported across cell membranes or taken up by cells, appropriately hybridize to targeted RNA or DNA, and subsequently terminate or disrupt nucleic acid function. These critical functions depend on the initial stability of oligonucleotides toward nuclease degradation.
A serious deficiency of oligonucleotides for these purposes, particularly antisense therapeutics, is the enzymatic degradation of the administered oligonucleotide by a variety of ubiquitous nucleolytic enzymes, intracellularly and extracellularly located, hereinafter referred to as "nucleases". It is unlikely that unmodified, "wild type", oligonucleotides will be useful therapeutic agents because they are rapidly degraded by nucleases. Modification of oligonucleotides to render them resistant to nucleases is therefore currently a primary focus of antisense research.
Modifications of oligonucleotides to enhance nuclease resistance have heretofore exclusively taken place on the sugar-phosphate backbone, particularly on the phosphorus atom. Phosphorothioates, methyl phosphonates, phosphorimidates, and phosphorotriesters (phosphate methylated DNA) have been reported to have various levels of resistance to nucleases. However, while the ability of an antisense oligonucleotide to bind to specific DNA or RNA with fidelity is fundamental to antisense methodology, modified phosphorous oligonucleotides, while providing various degrees of nuclease resistance, suffer from inferior hybridization properties.
Due to the prochiral nature of the phosphorous atom, modifications on the internal phosphorus atoms of modified phosphorous oligonucleotides result in Rp and Sp stereoisomers. Since a practical synthesis of stereo regular oligonucleotides (all Rp or Sp phosphate linkages) is unknown, oligonucleotides with modified phosphorus atoms have n 2 isomers with n equal to the length or the number of the bases in the oligonucleotide. Furthermore, modifications on the phosphorus atom have unnatural bulk about the phosphorodiester linkage which interferes with the conformation of the sugar-phosphate backbone and consequently, the stability of the duplex. The effects of phosphorus atom modifications cause inferior hybridization to the targeted nucleic acids relative to the unmodified oligonucleotide hybridizing to the same target.
The relative ability Of an oligonucleotide to bind to complementary nucleic acids is compared by determining the melting temperature of a particular hybridization complex. The melting temperature (T m ), a characteristic physical property of double helixes, denotes the temperature in degrees centigrade at which 50% helical versus coil (unhybridized) forms are present. T m is measured by using the UV spectrum to determine the formation and breakdown (melting) of hybridization. Base stacking, which occurs during hybridization, is accompanied by a reduction in UV absorption (hypochromicity). Consequently a reduction in UV absorption indicates a higher T m . The higher the T m , the greater the strength of the binding of the strands. Non-Watson-Crick base pairing has a strong destabilizing effect on the T m . Consequently, absolute fidelity of base pairing is necessary to have optimal binding of an antisense oligonucleotide to its targeted RNA.
Considerable reduction in the hybridization properties of methyl phosphonates and phosphorothioates has been reported by Cohen. Methyl phosphonates have a further disadvantage in that the duplex formed with RNA does not activate degradation by RNase H as an terminating event, but instead acts by hybridization arrest which can be reversed due to a helical melting activity located on the ribosome. Phosphorothioates are highly resistant to most nucleases. However, phosphorothioates typically exhibit non-antisense modes of action, particularly the inhibition of various enzyme functions due to nonspecific binding. Enzyme inhibition by sequence-specific oligonucleotides undermines the very basis of antisense chemotherapy.
Therefore, oligonucleotides modified to exhibit resistance to nucleases, to activate the RNase H terminating event, and to hybridize with appropriate strength and fidelity to its targeted RNA (or DNA) are greatly desired for antisense oligonucleotide therapeutics.
M. Ikehara et al., European Journal of Biochemistry 139:447-450(1984) report the synthesis of a mixed octamer containing one 2'-deoxy-2'-fluoroguanosine residue or one 2'-deoxy-2'-fluoroadenine residue. W. Guschlbauer and K. Jankowski, Nucleic Acids Res. 8:1421 (1980) have shown that the contribution of the N form (3'-endo, 2'-exo) increases with the electronegativeness of the 2'-substituent. Thus, 2'-deoxy-2'-fluorouridine contains 85% of the C3'-endo conformer. M. Ikehara et al., Tetrahedron Letters 42:4073 (1979) have shown that a linear relationship between the electronegativeness of 2'-substituents and the % N conformation (3'-endo-2'-exo) of a series of 2'-deoxy-adenosines. M. Ikehara et al., Nucleic Acids Research 5:1877 (1978) have chemically transformed 2'-deoxy-2'-fluoro-adenosine to its 5'-diphosphate. This was subsequently enzymatically polymerized to provide poly(2'-deoxy-2'-fluoroadenylic acid).
Furthermore, evidence was presented which indicates that 2'-substituted 2'-deoxyadenosines polynucleotides resemble double stranded RNA rather, than DNA. M. Ikehara et al., Nucleic Acids Res. 5:3315 (1978) show that a 2'-fluorine substituent in poly A, poly I, and poly C duplexed to their U, C, or I complement are significantly more stable than the ribo or deoxy poly duplexes as determined by standard melting assays. M. Ikehara et al., Nucleic Acids Res. 4:4249 (1978) show that a 2'-chloro or bromo substituents in poly(2'-deoxyadenylic acid) provides nuclease resistance. F. Eckstein et al., Biochemistry 11:4336 (1972) show that poly(2'-chloro-2'-deoxyuridylic acid) and poly(2'-chloro-2'-deoxycytidylic acid) are resistant to various nucleases. H. Inoue et al., Nucleic Acids Research 15:6131 (1987) describe the synthesis of mixed oligonucleotide sequences containing 2'-OMe at every nucleotide unit. The mixed 2'-OMe substituted sequences hybridized to their ribooligonucleotide complement (RNA) as strongly as the ribo-ribo duplex (RNA-RNA) which is significantly stronger than the same sequence ribo-deoxyribo heteroduplex (T m s, 49.0 and 50.1 versus 33.0 degrees for nonamers). S. Shibahara et al., Nucleic Acids Research 17:239 (1987) describe the synthesis of mixed oligonucleotides sequences containing 2'-OMe at every nucleotide unit. The mixed 2'-OMe substituted sequences were designed to inhibit HIV replication.
It is thought that the composite of the hydroxyl group's steric effect, its hydrogen bonding capabilities, and its electronegativeness versus the properties of the hydrogen atom is responsible for the gross structural difference between RNA and DNA. Thermal melting studies indicate that the order of duplex stability (hybridization) of 2'-methoxy oligonucleotides is in the order of RNA-RNA, RNA-DNA, DNA-DNA.
The 2'-deoxy-2'-halo, azido, amino, methoxy homopolymers of several natural occurring nucleosides have been prepared by polymerase processes. The required 2'-modified nucleosides monomers have not been incorporated into oligonucleotides via nucleic acids synthesizer machines. Thus, mixed sequence (sequence-specific) oligonucleotides containing 2'-modifications at each sugar are not known except for 2'-deoxy-2'-methoxy analogs.
OBJECTS OF THE INVENTION
It is a principal object of the invention to provide nuclease resistant, sugar modified oligonucleotides or oligonucleotide analogs for use in antisense oligonucleotide diagnostics, research reagents, and therapeutics.
It is a further object of the invention to provide such oligonucleotides or oligonucleotides analogs which are effective in modulating the activity of a DNA or an RNA.
Another object of the invention is to provide such oligonucleotides or oligonucleotide analogs which are less likely to invoke undesired or toxic side reactions.
Yet another object of the invention is to provide research and diagnostic methods and materials for assaying bodily states in animals, especially diseased states.
A further object of the invention is to provide therapeutic and research methods and materials for the treatment of diseases through modulation of the activity of DNA and RNA.
These and other objects will become apparent to persons of ordinary skill in the art from a review of the present specification and attendant claims.
SUMMARY OF THE INVENTION
In accordance with the present invention, compositions which are resistant to nuclease degradation and but which modulate the activity of DNA and RNA are provided. These compositions are comprised of sugar modified oligonucleotides or oligonucleotide analogs, the targeting portions of which are specifically hybridizable with preselected nucleotide sequences of single-stranded or double-stranded DNA or RNA. The sugar modified oligonucleotides recognize and form double strands with single stranded DNA and RNA or triple strands with double stranded DNA and RNA.
The nuclease resistant oligonucleotides of this invention consist of a single strand of nucleic acid bases linked together through linking groups. The target portion of the nuclease resistant oligonucleotide may range in length from about 5 to about 50 nucleic acid bases. However, in accordance with the preferred embodiment of this invention, a target sequence of about 15 bases in length is optimal.
The nucleic acid bases may be pyrimidines such as thymine, uracil or cytosine, or purines such as guanine or adenine, or both, arranged in a specific sequence. The sugar moiety of such bases may be of the deoxyribose or ribose type. The groups linking the bases together may be the usual sugar phosphate nucleic acid backbone, but may also be modified as a phosphorothioate, methylphosphonate, or phosphate alkylated moiety to further enhance the sugar modified oligonucleotide properties, along with removal of a 5'-methylene group and/or carbocyclic sugar.
In accordance with this invention, the targeting portion is an analog of an oligonucleotide wherein at least one of the 2'-deoxy ribofuranosyl moieties of the nucleoside unit is modified. A hydrogen or a hydroxyl, halo, azido, amino, methoxy or alkyl group may be added. For example, H, OH, F, CN, CF 3 , OCF 3 , OCN, O-alkyl, S-alkyl, SO-alkyl, SO 2 -alkyl, ONO 2 , NO 2 , N 3 , NH 2 , NH-alkyl, OCH 2 CH═CH 2 (allyloxy), OCH═CH 2 , OCCH where alkyl is a straight or branched chain of C1 to C12 may be used, with unsaturation within the carbon chain, such as allyloxy being particularly preferred.
The resulting novel oligonucleotides or oligonucleotide analogs are resistant to nuclease degradation and exhibit hybridization properties of higher quality relative to wild type (DNA-DNA and RNA-DNA) duplexes and the phosphorus modified oligonucleotide antisense duplexes containing phosphorothioates, methylphosphonates, phophoramidates and phosphorotriesters.
The invention is also directed to methods for modulating the production of a protein by an organism comprising contacting the organism with a composition formulated in accordance with the foregoing considerations. It is preferred that the RNA or DNA portion which is to be modulated be preselected to comprise that portion of DNA or RNA which codes for the protein whose formation is to be modulated. The targeting portion of the composition to be employed is, thus, selected to be complementary to the preselected portion of DNA or RNA, that is to be an antisense oligonucleotide for that portion.
This invention is also directed to methods of treating an organism having a disease characterized by the undesired production of a protein. This method comprises contacting the organism with a composition in accordance with the foregoing considerations. The composition is preferably one which is designed to specifically bind with messenger RNA which codes for the protein whose production is to be inhibited.
The invention further is directed to diagnostic methods for detecting the presence or absence of abnormal RNA molecules or abnormal or inappropriate expression of normal RNA molecules in organisms or cells.
The invention is also directed to methods for the selective binding of RNA for research and diagnostic purposes. Such selective, strong binding is accomplished by interacting such RNA or DNA with compositions of the invention which are resistant to degradative nucleases and hybridize stronger and with greater fidelity than any other known oligonucleotide or oligonucleotide analog.
Additionally this invention is directed to a method of synthesis of 2'-deoxy-2'-substituted nucleosides, particularly guanosine compounds. In accordance with this method, the 2'-hydroxyl moiety of guanosine is first oxidized and then reduced with inversion about the 2' position to yield 9-(β-D-arabinofuranosyl)guanine. The 2' arabino hydroxyl group is derivatized with a leaving group. Nucleophilic displacement of the leaving group with a nucleophile is accomplished with a further inversion to give the 2'-deoxy-2'-substituted guanosine compound.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The compositions useful for modulating the activity of an RNA or DNA molecule in accordance with this invention generally comprise a sugar modified oligonucleotide containing a target sequence which is specifically hybridizable with a preselected nucleotide sequence of single stranded or double stranded DNA or RNA molecule and which is nuclease resistant.
It is generally desirable to select a sequence of DNA of RNA for or which is involved in the production of proteins whose synthesis is ultimately to be modulated or inhibited in entirety. The targeting portion of the composition is generally an oligonucleotide analog. It is synthesized, conveniently through solid state synthesis of known methodology, to be complementary to or at least to be specifically hybridizable with the preselected nucleotide sequence of the RNA or DNA. Nucleic acid synthesizers are commercially available and their use is generally understood by persons of ordinary skill in the art as being effective in generating nearly any oligonucleotide of reasonable length which may be desired.
In the context of this invention, the term "oligonucleotide" refers to a plurality of joined nucleotide units formed in a specific sequence from naturally occurring bases and pentofuranosyl groups joined through a sugar group by native phosphodiester bonds. These nucleotide units may be nucleic acid bases such as guanine, adenine, cytosine, thymine or uracil. The sugar group may be deoxyribose or ribose. This term refers to both naturally occurring or synthetic species formed from naturally occurring subunits.
"Oligonucleotide analog" as the term is used in connection with this invention, refers to moieties which function similarly to oligonucleotides but which have non-naturally occurring portions. Oligonucleotide analogs may have altered sugar moieties or inter-sugar linkages, for example, phosphorothioates and other sulfur containing species which are known for use in the art. Oligonucleotide analogs may also comprise altered base units or other modifications consistent with the spirit of this invention, and in particular such modifications as may increase nuclease resistance of the oligonucleotide composition in order to facilitate antisense therapeutic, diagnostic or research reagent use of a particular oligonucleotide.
It is generally preferred for use in some embodiments of this invention that some positions of the nucleotide base be substituted in order to increase the nuclease resistance of the composition while maintaining the integrity of the oligonucleotide binding capabilities.
It is preferred in some embodiments of the present invention to employ further modified oligonucleotides. In this context, modified oligonucleotide analogs refers to a structure which is generally similar to native oligonucleotides, but which have been modified in one or more significant ways.
Such modifications may take place at the sugar backbone of the invention. It is generally preferred to enhance the ability of the target sequence of the sugar modified oligonucleotides to penetrate into the intracellular spaces of cells where the messenger RNA or DNA, which are the targets of the overall composition, reside. Therefore, it is generally preferred to provide modifications of oligonucleotides which are substantially less ionic than native forms in order to facilitate penetration of the oligonucleotide into the intracellular spaces. Any of the existing or yet to be discovered methods for accomplishing this goal may be employed in accordance with the practice of the present invention. At present, it has been found preferable to employ substitutions for the phosphorodiester bond, which substitutions are not only relatively less ionic than the naturally occurring bonds but are also substantially non-chiral.
As will be appreciated, the phosphorus atom in the phosphorodiester linkage is "pro-chiral". Modifications at the phosphorus, such as is done in methyl phosphonates and phosphorothioates type oligonucleotides, results in essentially chiral structures. Chirality results in the existence of two isomers at each chiral center which may interact differently with cellular molecules. Such an unresolved mixture of isomers may inhibit the transport of the resulting compositions into the intracellular spaces or decrease the affinity and specificity of hybridization to the specific target RNA or DNA. Thus, it is preferred in some embodiments of this invention to employ substantially non-ionic, substantially non-chiral entities in lieu of some or all of the phosphorodiester bonds. For this purpose, short chain alkyl or cycloalkyl structures especially C 2 -C 4 structures are preferred. As is set forth in an application filed on even date herewith and assigned to a common assignee hereof, said application being entitled "Polyamine Oligonucleotides to Enhance Cellular Uptake," application Ser. No. 558,663 filed Jul. 27, 1990 (attorney docket ISIS-24) the modification of the sugar structure including the elimination of one of the oxygen functionality may permit the introduction of such substantially non-chiral, non-ionic substituents in this position. The entirety of the disclosure of application Ser. No. 558,663 is incorporation herein by reference in order to disclose more fully such modifications.
In keeping with the goals of the invention are the standard backbone modifications such as substituting P for S, Me-P, MeO-P, H 2 N-P, etc. These substitutions are thought in some cases to enhance the sugar modified oligonucleotide properties.
The targeting portion of the compositions of the present invention, are preferably oligonucleotide analogs having 5 to about 50 base units. It is more preferred that such functionalities have from 8 to about 40 base units and even more preferred that from about 12 to 20 base units be employed. Oligonucleotides or oligonucleotide analogs having about 15 base units are preferable for the practice of certain embodiments of the present invention.
It is desired that the targeting portion be adapted so as to be specifically hybridizable with the preselected nucleotide sequence of the RNA or DNA selected for modulation. Oligonucleotide analogs particularly suited for the practice of one or more embodiments of the present invention comprise 2'-sugar modified oligonucleotides wherein one or more of the 2'-deoxy ribofuranosyl moieties of the nucleoside unit is modified with a hydrogen or hydroxyl, halo, azido, amino, alkyoxy, thioalkoxy, alkylamino or alkyl group. For example, the substitutions which may occur include H, OH, F, CN, CF 3 , OCF 3 , OCN, O-alkyl, S-alkyl, SOMe, SO 2 Me, ONO 2 , NO 2 , N 3 , NH 2 , NH-alkyl, OCH═CH 2 , OCCH where alkyl is a straight or branched chain of C 1 to C 12 with unsaturation within the carbon chain such as allyloxy.
These modified bases are linked together and to the rest of the oligonucleotide or oligonucleotide analog through a sugar linking group. The linking group may be any of those structures described herein which are capable of linking sugar moieties of oligonucleotides together to form the targeting portion of the compositions of this invention. It is preferred that these sugar linking groups comprise the phosphodiester structure or a derivative of such. Derivatives of the phosphodiester structure may include substitution of a sulphur, an alkoxy group such as methyl, methyl oxide, or amine group for an oxygen. The sugar phosphate nucleic acid backbone may be modified as a phosphorothioate, alkylphosphonate such as methylphosphonate or phosphate alkylated moiety (a phosphotriester). The phosphodiester linkage may also be replaced by a carbon or ether linkage.
In further embodiment of this invention, a linking moiety has been devised to allow the direct attachment of a modified unit to the terminal position of the 3'-end of the modified oligonucleotides. Thus, an ester, or more preferably a bromomethylketo group, is attached to the 3'-hydroxyl of a modified 2'-modified nucleoside having its 5'-hydroxyl protected with a dimethoxytriphenylmethyl group and, if the heterocycle is of the cytosine series, having that heterocycle protected with a benzoyl protecting group. If the required targeting sequence has a terminal 3'-thymine or cytosine base, the desired modified thymine or cytosine base containing the bromomethylketo linker is utilized as the first monomer to attach to the control pore glass (CPG) solid support which contains a normal nucleoside attached via its 3'-hydroxyl group. The base sensitive ester linkage attaching the 2'-modified nucleoside to the nucleoside attached to the CPG is cleaved under the usual concentrated ammonium hydroxide conditions that are utilized to remove the oligonucleotide from the CPG support. This will allow the modified oligonucleotide to have a 2'-modified unit at its terminal, 3'-end.
Cleavage of oligonucleotides by nucleolytic enzymes require the formation of an enzyme-substrate complex, or in particular a nuclease-oligonucleotide complex. The nuclease enzymes will generally require specific binding sites located on the oligonucleotides for appropriate attachment. If the oligonucleotide binding sites are removed or hindered such that the nucleases will not attach to the oligonucleotides, the nuclease resistant oligonucleotides result. In the case of restriction endonucleases that cleave sequence-specific palindromic double-stranded DNA, certain binding sites such as the ring nitrogen in the 3- and 7-positions have been identified as required hiding sites. Removal of one or more of these sites or hindering the nuclease approach to these particular positions within the recognition sequence has provided various levels or resistance to the specific nucleases.
This invention provides antisense oligonucleotides characterized by superior hybridizing properties. We have discovered from structure activity relationships studies that a significant increase in binding (T m )s of certain 2'-sugar modified oligonucleotides to its RNA target (complement) is correlated with an increased "A" type conformation of the heteroduplex. Furthermore, absolute fidelity of the modified oligonucleotides is maintained. The increased binding of our 2'-sugar modified sequence-specific oligonucleotides provides superior potency and specificity compared to phosphorus modified antisense oligonucleotides such as methyl phosphonates, phosphorothioates, phosphate triesters and phosphoramidites as known in the literature.
The only structural difference between DNA and RNA duplexes is an hydrogen atom in the 2'-position of the DNA ribofuranosyl moieties versus a hydroxyl group in the 2'-position of the RNA ribofuranosyl moieties (assuming that the presence or absence of a methyl group in the uracil ring system has no effect). However, gross conformational differences exist between DNA and RNA duplexes.
It is known from X-ray diffraction analysis of nucleic acid fibers, Arnott and Hukins, Biochemical and Biophysical Research Communication, 47:1504-1510 (1970), and analysis of crystals of double-stranded nucleic acids that DNA takes a "B" form structure and that RNA only takes the much more rigid "A" form structure. The difference between the sugar puckering (C2' endo for "B" form DNA and C3' endo for A-form RNA) of the nucleoside monomeric units of DNA and RNA is the major conformational difference between double-stranded nucleic acids.
The primary contributor to the pentofuranosyl moiety conformation is the nature of the substituent in the 2'-position. Thus, the population of the C3'-endo form increases with respect to the C2'-endo as the electronegativity of the 2'-substituent increases. For example, among 2'-deoxy-2'-halo-adenine nucleosides, the 2'-fluoro derivative exhibits the largest population (65%) of C3'-endo, and the 2'-iodo shows the lowest (7%). Those of the adenosine (2'-OH) and deoxyadenosine (2'-H) are 36% and 19%, respectively. Furthermore, the effect of the 2'-fluoro group of adenine dinucleotides (2'-deoxy-2'-fluoroadenosine-2'-deoxy-2'-fluoroadenosine or uridine) is further correlated to the stabilization of the stacked conformations more than ribo or deoxyribo modified dimers. Research indicates that the dinucleosides phosphates have a stacked conformation with a geometry similar to that of A--A but with a greater extent of base-base overlapping than A--A. It was assumed that the highly polar nature of the C2'-F bond and the extreme preference for C3'-endo puckering may stabilize the stacked conformation in an "A" structure.
Data from UV hypochromicity, circular dichromism, and 'H NMR also indicate that the degree of stacking decreases as the electronegativeness of halogen decreases. Furthermore, a steric bulkiness in the 2'-position is better accommodated in an "A" form duplex than a "B" form duplex.
Thus, a 2'-substituent on the 3'-nucleotidyl unit of a dinucleoside monophosphate is thought to exert a number of effects on the stacking conformation: steric repulsion, furanose puckering preference, electrostatic repulsion, hydrophobic attraction, and hydrogen bonding capabilities. These substituent effects are thought to be determined by the molecular size, electronegativity, and hydrophobicity of the substituent.
The 2'-iodo substituted nucleosides possess the lowest C3'-endo population (7%) of the halogen series. Thus, on steric effects alone, one would predict an 2'-iodo or similar groups would contribute stacking destabilizing properties and thus reduced binding (T m )s for antisense oligonucleotides. However, the lower electronegativeness and high hydrophobic attractive forces of the iodine atom and similar groups complicates the ability to predict stacking stabilities and binding strengths.
Studies with the 2'-OMe modification of 2'-deoxy guanosine, cytidine, and uridine dinucleoside phosphates exhibit enhanced stacking effects with respect to the corresponding unmethylated species (2'-OH). In this case, the hydrophobic attractive forces of the methyl group tend to overcome the destablilizing effects of its steric bulkiness (hindrance).
2'-Fluoro-2'-deoxyadenosine has been determined to have an unusually high population of 3'-endo puckering among nucleosides. Adenosine, 2'-deoxyadenosine, and other derivatives typically have population below 40% in the 3'-endo conformer. It is known that a nucleoside residue in well-stacked oligonucleotides favors 3'-endo ribofuranose puckering.
Melting temperatures (complementary binding) are increased with the 2'-substituted adenosine diphosphates. It is not clear whether the 3'-endo preference of the conformation or the presence of the substituent is responsible for the increased binding. However, as noted, greater overlap of adjacent bases (stacking) can be achieved with the 3'-endo conformations.
The present novel approach to obtaining stronger binding is to prepare antisense RNA mimics to bind to the targeted RNA. Therefore, a random structure-activity relationship approach was undertaken to discover nuclease resistant antisense oligonucleotides that maintained appropriate hybridization properties.
A series of 2'-deoxy-2'-modified nucleosides of adenine, guanine, cytosine, thymidine and certain analogs of these bases have been prepared and have been inserted as the modified nucleosides into sequence-specific oligonucleotides via solid phase nucleic acid synthesis. The novel antisense oligonucleotides were assayed for their ability to resist degradation by nucleases and to possess hybridization properties comparable to the unmodified parent oligonucleotide. Initially, small electronegative atoms or groups were selected because these type are not likely to sterically interfere with required Watson-Crick base pair hydrogen bonding (hybridization). However, electronic changes due to the electronegativeness of the atom or group in the 2'-position may profoundly effect the sugar conformation. During our structure activity relationship studies we discovered that the sugar modified oligonucleotides hybridized to the targeted RNA stronger than the unmodified (2'-deoxyribosyl type).
2'-Substituted oligonucleotides are synthesized by the standard solid phase, automated nucleic acid synthesizer such as the Applied Biosystems, Incorporated 380B or MilliGen/Biosearch 7500 or 8800. Triester, phosphoramidite, or hydrogen phosphonate coupling chemistries (Oligonucleotides. Antisense Inhibitors of Gene Expression. M. Caruthers, pp 7-24, Edited by J. S. Cohen, CRC Press, Inc. Boca Raton, Fla., 1989) are used in with these synthesizers to provide the desired oligonucleotides. The Beaucage reagent (Journal of American Chemical Society, 112, 1253-1255, 1990) or elemental sulfur (S. Beaucage et al., Tetrahedron Letters, 22,1859-1862, 1981) is used with phosphoramidite or hydrogen phosphonate chemistries to provide 2'-substituted phosphorothioate oligonucleotides.
The requisite 2'-substituted nucleosides (A, G, C, T(U), and nucleic acid base analogs) are generally prepared by modification of several literature procedures as described below.
Procedure 1. Nucleophilic Displacement of 2'-Leaving Group in Arabino Purine Nucleosides. Nucleophilic displacement of a leaving group in the 2'-up position (2'-deoxy-2'-(leaving group)arabino sugar) of adenine or guanine or their analog nucleosides. General synthetic procedures of this type have been described by M. Ikehara et al., Tetrahedron 34:1133-1138 (1978); ibid., 31:1369-1372 (1975); Chemistry and Pharmaceutical Bulletin, 26:2449-2453 (1978); ibid., 26:240-244 (1978); M. Ikehara Accounts of Chemical Research, 2:47-53 (1969); and R. Ranganathan Tetrahedron Letters, 15:1291-1294 (1977).
Procedure 2. Nucleophilic Displacement of 2,2'-Anhydro Pyrimidines. Nucleosides thymine, uracil, cytosine or their analogs are converted to 2'-substituted nucleosides by the intermediacy of 2,2'-cycloanhydro nucleoside as described by J. J. Fox, et al., Journal of Organic Chemistry, 29:558-564 (1964).
Procedure 3. 2'-Coupling Reactions. Appropriately 3',5'-sugar and base protected purine and pyrimidine nucleosides having a unprotected 2'-hydroxyl group are coupled with electrophilic reagents such as methyl iodide and diazomethane to provide the mixed sequences containing a 2'-OMe group H. Inoue, et al., Nucleic Acids Research 15: 6131-6148.
Procedure 4. 2-Deoxy-2-substituted Ribosylations. 2-Substituted-2-deoxyribosylation of the appropriately protected nucleic acid bases and nucleic acids base analogs has been reported by E. T. Jarvi, et al., Nucleosides & Nucleotides 8:1111-1114 (1989) and L. W. Hertel, et al., Journal of Organic Chemistry 53:2406-2409 (1988).
Procedure 5. Enzymatic Synthesis of 2'-Deoxy-2'-Substituted Nucleosides. The 2-Deoxy-2-substituted glycosyl transfer from one nucleoside to another with the aid of pyrimidine and purine ribo or deoxyribo phosphorolyses has been described by J. R. Rideout and T. A. Krenitsky, U.S. Pat. No. 4,381,344 (1983).
Procedure 6. Conversion of 2'-Substituents Into New Substituents. 2'-Substituted-2'-deoxynucleosides are converted into new substituents via standard chemical manipulations. For example, S. Chladek et al., Journal of Carbohydrates, Nucleosides & Nucleotides 7:63-75 (1980) describes the conversion of 2'-deoxy-2'-azidoadenosine, prepared from arabinofuranosyladenine, into 2'-deoxy-2'-aminoadenosine.
Procedure 7. Free Radical Reactions. Conversions of halogen substituted nucleosides into 2'-deoxy-2'-substituted nucleosides via free radical reactions has been described by K. E. B. Parkes and K. Taylor, Tetrahedron Letters 29:2995-2996 (1988).
Procedure 8. Conversion of Ribonucleosides to 2'-Deoxy-2'-Substituted Nucleoside. Appropriately 3',5'-sugar and base protected purine and pyrimidine nucleosides having a unprotected 2'-hydroxyl group are converted to 2'-deoxy-2'-substituted nucleosides by the process of oxidation to the 2'-keto group, reaction with nucleophilic reagents, and finally 2'-deoxygenation. Procedures of this type have been described by F. De las Heras, et al., Tetrahedron Letters 29:941-944 (1988).
Procedure 9. In a preferred process of the invention, 2'-deoxy-substituted guanosine compounds are prepared via n (arabinofuranosyl)guanine intermediate obtained via an oxidation-reduction reaction. A leaving group at the 2' position of the arabinofuranosyl sugar moiety of the intermediate arabino compound is displaced via an SN 2 reaction with an appropriate nucleophile. This procedure thus incorporate principles of both Procedure 1 and Procedure 8 above. 2'-Deoxy-2'-fluoroguanosine is preferably prepared via this procedure. The intermediate arabino compound was obtained utilizing a variation of the oxidation-reduction procedure of Hansske, F., Madej, D. and Robins, M. J. (1984), Tetrahedron, 40:125. According to this invention, the reduction was effected starting at -78° C. and allowing the reduction reaction to exothermically warm to about -2° C. This results in a high yield of the intermediate arabino compound.
In conjunction with use of a low temperature reduction, utilization of a tetraisopropyldisiloxane blocking group (a "TPDS" group) for the 3' and 5' positions of the starting guanosine compound contributes in an improved ratio of intermediate arabino compound verses the ribo compound following oxidization and reduction. Following oxidation/reduction, the N 2 guanine amino nitrogen and the 2'-hydroxyl moieties of the intermediate arabino compound are blocked with isobutyryl protecting groups ("Ibu" groups). The tetraisopropyldisiloxane blocking group is removed and the 3' and 5' hydroxyl's are further protected with a second blocking group, a tetrahydropyranyl blocking group (a "THP" group). The isobutyryl group is selectively removed from 2'-hydroxyl group followed by derivation of the 2' position with a triflate (a trifluoromethylsulfonyl) leaving group. The triflate moiety was then displaced with inversion about the 2' position to yield the desire 2'-deoxy-2'-fluoroguanosine compound.
In addition to the triflate leaving group, other leaving groups include but are not necessarily limited to alkysulfonyl, substituted alkylsulfonyl, arylsulfonyl, substituted arylsulfonyl, heterocyclosulfonyl or trichloroacetimidate. Representative examples include p-(2,4-dinitroanilino)benzenesulfonyl, benzenesulfonyl, methylsulfonyl, p-methylbenzenesulfonyl, p-bromobenzenesulfonyl, trichloroacetimidate, acyloxy, 2,2,2-trifluoro-ethanesulfonyl, imidazolesulfonyl and 2,4,6-trichlorophenyl.
The isobutyryl group remaining on the N 2 heterocycllc amino moiety of the guanine ring can be removed to yield a completely deblocked nucleoside; however, preferably for incorporation of the 2'-deoxy-2'-substituted compound in an oligonucleotide, deblocking of the N 2 isobutyryl protecting group is deferred until after oligonucleotide synthesis is complete. Normally for use on automated nucleic acid synthesizers, blocking of the N 2 guanine amino moiety with an isobutyryl group is preferred. Thus advantageously, the N 2 -isobutyryl blocked 2'-deoxy-2'-substituted guanosine compounds resulting from the method of the invention can be directly used for oligonucleotide synthesis on automatic nucleic acid synthesizers.
The oligonucleotides or oligonucleotide analogs of this invention can be used in diagnostics, therapeutics, and as research reagents and kits. For therapeutic use the oligonucleotide is administered to an animal suffering from a disease affected by some protein. It is preferred to administer to patients suspected of suffering from such a disease with amounts of oligonucleotide which are effective to reduce the symptemology of that disease. It is within the scope of a person's skill in the art to determine optimum dosages and treatment schedules for such treatment regimens.
It is generally preferred to apply the therapeutic agents in accordance with this invention internally such as orally, intravenously, or intramuscularly. Other forms of administration, such as transdermally, topically, or intralesionally may also be useful. Inclusion in suppositories may also be useful. Use of pharmacologically acceptable carriers is also preferred for some embodiments.
The following examples illustrate the practice of this invention.
EXAMPLE 1
Preparation of 2'-Deoxy-2'-fluoro Modified Oligonucleotides
A. N 6 -Benzoyl- 2'-deoxy-2'-fluoro-5'-O-(4,4'-dimethoxytrityol)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethyl phosphoramidite.
N 6 -Benzoyl-9-(2'-fluoro-β-D-ribofuranosyl)adenine was prepared from 9-β-D-arabinofuranosyladenine in a five-step synthesis using a modification of a procedure reported by M. Ikehara at al., Nucleosides and Nucleotides 2:373-385 (1983). Thus, the N 6 -benzoyl derivative was obtained in good yield utilizing the method of transient protection with chlorotrimethylsilane. R. A. Jones, J. Am. Chem. Soc. 104:1316 (1982). Selective protection of the 3' and 5'-hydroxyl groups of N 6 -Benzoyl-9-β-D-arabinofuranosyladenine with tetrahydropyranyl (THP) was accomplished by modification of a literature procedure G. Butke, et al., in Nucleic Acid Chemistry, Part 3:149-152, Townsend, L. B. and Tipson, R. S. eds., (J. Wiley and Sons, New York 1986) to yield N 6 -Benzoyl-9- 3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabino furanosyl!adenine in good yield. Treatment of N 6 -Benzoyl-9- 3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl! adenine with trifluoromethanesulfonic anhydride in dichloromethane gave the 2'-triflate derivative N 6 -Benzoyl-9- 2'-O-trifluoromethylsulfonyl-3',5'-di-O-tetrahydropyran-2-yl)-β-D-arabino furanosyl!adenine which was not isolated due to its lability. Displacement of the 2'-triflate group was effected by reaction with tetrabutylammonium fluoride in tetrahydrofuran to obtain a moderate yield of the 2'-fluoro derivative N 6 -Benzoyl-9- 2'-fluoro-3',5'-di-O-tetrahydro-pyran-2-yl)-β-D-arabinofuranosyl!adenine. Deprotection of the THP groups of N 6 -Benzoyl-9- 2'-fluoro-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabino furanosyl!adenine was accomplished by treatment with Dowex-50W in methanol to yield N 6 -benzoyl-9-(2'-deoxy-2'-fluoro-β-D-ribofuranosyl)adenine in moderate yield. The 1 H-NMR spectrum of 6 was in agreement with the literature values. M. Ikehara and H. Miki, Chem. Pharm. Bull. 26: 2449-2453 (1978). Standard methodologies were employed to obtain the 5'-dimethoxytrityl-3'-phosphoramidite intermediates N 6 -Benzoyl-9- 2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-β-D-ribofuranosyl!adenine and N 6 -Benzoyl- 2'-deoxy-2'-fluoro-5'-O-(4,4'-dimethoxytrityl)! adenosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite, K. K. Ogilvie, Can J. Chem. 67: 831-839 (1989).
B. N 6 -Benzoyl-9-β-D-arabinofuranosyladenine.
9-β-D-arabinofuranosyladenine (1.07 g, 4.00 m.mol) was dissolved in anhydrous pyridine (20 mL) and anhydrous dimethylformamide (20 mL) under an argon atmosphere. The solution was cooled to ice temperature and chlorotrimethylsilane (3.88 ml, 30.6 m.mol) was added slowly to the reaction mixture via syringe. After stirring the reaction mixture at ice temperature for 30 minutes, benzoyl chloride (2.32 ml, 20 m.mol) was added slowly. The reaction mixture was allowed to warm to 20° C. and stirred for 2 hours. After cooling the reaction mixture to ice temperature, cold water (8 ml) was added and the mixture was stirred for 15 minutes. Concentrated ammonium hydroxide (8 ml) was slowly added to the reaction mixture to give a final concentration of 2M of ammonia. After stirring the cold reaction mixture for 30 minutes, the solvent was evaporated in vacuo (60 torr) at 20° C. followed by evaporation in vacuo (1 torr) at 40° C. to give an oil. This oil was triturated with diethyl ether (50 ml) to give a solid which was filtered and washed with diethyl ether three times. This crude solid was triturated in methanol (100 ml) at reflux temperature three times and the solvent was evaporated to yield N 6 -benzoyl-9-(β-D-arabinofuranosyladenine)adenine as a solid (1.50 g, 100%).
C. N 6 -Benzoyl-9- 3",5"-di-)-tetrahydropyran-2-yl)-D-arabinofuranosyl! adenine.
N 6 -benzoyl-9-(β-D-arabinofuranosyl)adenine (2.62 g, 7.06 m.mol) was dissolved in anhydrous dimethylformamide (150 ml) under an argon atmosphere and p-toluenesulfonic acid monohydrate (1.32 g, 6.92 m.mol) was added. This solution was cooled to ice temperature and dihydropyran (1.26 ml, 13.8 m.mol) was added via syringe. The reaction mixture was allowed to warm to 20° C. Over a period of 5 hours a total of 10 equivalents of dihydropyran were added in 2 equivalent amounts in the fashion described. The reaction mixture was cooled to ice temperature and saturated aqueous sodium bicarbonate was added slowly to a pH of 8, then water was added to a volume of 750 ml. The aqueous mixture was extracted with methylene chloride four times (4×200 ml), and the organic phases were combined and dried over magnesium sulfate. The solids were filtered and the solvent was evaporated in vacuo (60 torr) at 30° C. to give a small volume of liquid which was evaporated in vacuo (1 torr) at 40° C. to give an oil. This oil was coevaporated with p-xylene in vacuo at 40° to give an oil which was dissolved in methylene chloride (100 ml). Hexane (200 ml) was added to the solution and the lower-boiling solvent was evaporated in vacuo at 30° C. to leave a white solid suspended in hexane. This solid was filtered and washed with hexane three times (3×10 ml) then purified by column chromatography using silica and methylene chloride-methanol (93:7, v/v) as eluent. The first fraction yielded the title compound 3 as a white foam (3.19 g, 83%) and a second fraction gave a white foam (0.81 g) which was characterized as the 5'-mono-tetrahydropyranyl derivative of N 6 -benzoyl-9-(β-D-arabinofuranosyl)adenine.
D. N 6 -Benzoyl-9- 2'-O-trifluoromethylsulfonyl-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine.
N 6 -Benzoyl-9- 3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine (2.65 g, 4.91 m.mol) was dissolved in anhydrous pyridine (20 ml) and the solvent was evaporated in vacuo (1 mm Hg) at 40° C. The resulting oil was dissolved in anhydrous methylene chloride (130 ml) under an argon atmosphere and anhydrous pyridine (3.34 ml, 41.3 m.mol) and N,N-dimethylaminopyridine (1.95 g, 16.0 mmol) were added. The reaction mixture was cooled to ice temperature and trifluoromethanesulfonic anhydride (1.36 ml, 8.05 mmol) was added slowly via syringe. After stirring the reaction mixture at ice temperature for 1 h, it was poured into cold saturated aqueous sodium bicarbonate (140 ml). The mixture was shaken and the organic phase was separated and kept at ice temperature. The aqueous phase was extracted with methylene chloride two more times (2×140 ml). The organic extracts which were diligently kept cold were combined and dried over magnesium sulfate. The solvent was evaporated in vacuo (60 torr) at 20° C. then evaporated in vacuo (1 torr) at 30° C. to give N 6 -Benzoyl-9- 2'-O-trifluoromethylsulfonyl-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine as a crude oil which was not purified further.
E. N 6 -Benzoyl-9- 2'-fluoro-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine.
N 6 -Benzoyl-9- 2'-O-trifluoromethylsulfonyl-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine (<4.9 mmol) as a crude oil was dissolved in anhydrous tetrahydro-furan (120 ml) and this solution was cooled to ice temperature under an argon atmosphere. Tetrabutylammonium fluoride as the hydrate (12.8 g, 49.1 mmol) was dissolved in anhydrous tetrahydrofuran (50 ml) and half of this volume was slowly added via syringe to the cold reaction mixture. After stirring at ice temperature for 1 hour, the remainder of the reagent was added slowly. The reaction mixture was stirred at ice temperature for an additional 1 hour, then the solvent was evaporated in vacuo (60 torr) at 20° C. to give an oil. This oil was dissolved in methylene chloride (250 ml) and washed with brine three times. The organic phase was separated and dried over magnesium sulfate. The solids were filtered and the solvent was evaporated to give an oil. The crude product was purified by column chromatography using silica in a sintered-glass funnel (600 ml) and ethyl acetate was used as eluent. N 6 -Benzoyl-9- 2'-deoxy-2'-fluoro-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine was obtained as an oil (2.03 g, 76%).
F. N 6 -Benzoyl-9-(2'-deoxy-2'-fluoro-β-D-ribofuranosyl)adenine.
N 6 -Benzoyl-9- 2'-fluoro-3',5'-di-O-tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine (1.31 g, 2.42 mmol) was dissolved in methanol (60 ml), and Dowex 50W×2-100 (4 cm3, 2.4 m.eq) was added to the reaction mixture. The reaction mixture was stirred at 20° C. for 1 hour then cooled to ice temperature. Triethylamine (5 ml) was then slowly added to the cold reaction mixture to a pH of 12. The resin was filtered and washed with 30% triethylamine in methanol until the wash no longer contained UV absorbing material. Toluene (50 ml) was added to the washes and the solvent was evaporated at 24° C. in vacuo (60 torr then 1 torr) to give a residue. This residue was partially dissolved in methylene chloride (30 ml) and the solvent was transferred to a separatory funnel. The remainder of the residue was dissolved in hot (60° C.) water and after cooling the solvent it was also added to the separatory funnel. The biphasic system was extracted, and the organic phase was separated and extracted three times with water (3×100 ml). The combined aqueous extracts were evaporated in vacuo (60 torr then 1 torr Hg) at 40° C. to give an oil which was evaporated with anhydrous pyridine (50 ml). This oil was further dried in vacuo (1 torr Hg) at 20° C. in the presence of phosphorous pentoxide overnight to give N 6 -benzoyl-9-(2'-deoxy-2'-fluoro-β-D-ribofuranosyl)adenine as a yellow foam (1.08 g, 100%) which contained minor impurities.
G. N 6 -benzoyl-9- 2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-β-D-ribofuranosyl!adenine.
N 6 -benzoyl-9-(2'-fluoro-b-D-ribofuranosyl)adenine (1.08 g, 2.89 mmol) which contained minor impurities was dissolved in anhydrous pyridine (20 ml) under an argon atmosphere, and dry triethylamine (0.52 ml, 3.76 mmol) was added followed by addition of 4,4'-dimethoxytrityl chloride (1.13 g, 3.32 mmol). After 4 hours of stirring at 20° C. the reaction mixture was transferred to a separatory funnel and diethyl ether (40 ml) was added to give a white suspension. This mixture was washed with water three times (3×10 ml), the organic phase was separated and dried over magnesium sulfate. Triethylamine (1 ml) was added to the solution and the solvent was evaporated in vacuo (60 torr Hg) at 20° C. to give an oil which was evaporated with toluene (20 ml) containing triethylamine (1 ml). This crude product was purified by column chromatography using silica and ethyl-acetate-triethylamine (99:1, v/v) followed by ethyl acetate-methanol-triethylamine (80:19:1) to give the product in two fractions. The fractions were evaporated in vacuo (60 torr then 1 torr Hg) at 20° C. to give a foam which was further dried in vacuo (1 torr Hg) at 20° C. in the presence of sodium hydroxide to give N 6 -benzoyl-9- 2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-β-D-ribofuranosyl!adenine as a foam (1.02 g, 52%).
H. N 6 -Benzoyl- 2'-fluoro-5'-O-(4,4'-dimethoxytrityl)!adenosine-3'-O-N,N-diisopropyl-β-cyanoethyl phosphoramidite.
N 6 -Benzoyl-9- 2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-β-D-ribofuranosyl!adenine (1.26 g, 1.89 mmol) was dissolved in anhydrous dichloromethane (13 ml) under an argon atmosphere, diisopropylethylamine (0.82 ml, 4.66 mmol) was added, and the reaction mixture was cooled to ice temperature. Chloro(diisopropylamino)-β-cyanoethoxyphosphine (0.88 ml, 4.03 mmol) was added to the reaction mixture which was allowed to warm to 20° C. and stirred for 3 hours. Ethyl acetate (80 ml) and triethylamine (1 ml) were added and this solution was washed with brine solution three times (3×25 ml). The organic phase was separated and dried over magnesium sulfate. After filtration of the solids the solvent was evaporated in vacuo at 20° C. to give an oil which was purified by column chromatography using silica and hexane-ethyl acetate-triethyl-amine (50:49:1) as eluent. Evaporation of the fractions in vacuo at 20° C. gave a foam which was evaporated with anhydrous pyridine (20 ml) in vacuo (1 torr) at 26° C. and further dried in vacuo (1 torr Hg) at 20° C. in the presence of sodium hydroxide for 24 h to give N 6 -benzoyl- 2'-deoxy-2'-fluoro-5'-O-(4,4'-dimethoxytrityol)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite as a foam (1.05 g, 63%).
I. 2'-Deoxy-2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-uridine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
2,2'-Cyclouridine is treated with a solution of 70% hydrogen fluoride/pyridine in dioxane at 120° C. for ten hours to provide after solvent removal a 75% yield of 2'-deoxy-2'-fluorouridine. The 5'-DMT and 3'-cyanoethoxydiisopropylphosphoramidite derivitized nucleoside is obtained by standard literature procedures, M. J. Gait, ed., Oligonucleotide Synthesis. A Practical Approach, (IRL Press, Washington, D.C., 1984) or through the procedure of Example 1A.
J. 2'-Deoxy-2'-fluoro-5'-O-(4,4'-dimethoxytrityl)-cytidine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
2'-Deoxy-2'-fluorouridine is converted to the corresponding cytidine analog via a triazolo intermediate that in turn was aminated the heterocycle is then protected by selective N 4 -benzoylation. The 5'-O-(4,4'-dimethoxy-trityl)-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite) can be prepared in accordance with Example 1A.
K. 9-(3',5'- 1,1,3,3'-Tetraisopropyldisilox-1,3-diyl!-β-D-arabinofuranosyl)guanine.
The 3' and 5' positions of guanosine were protected by the addition of a TPDS (1,1,3,3-tetraisopropyldisilox-1,3-diyl) protecting group as per the procedure of Robins, M. J., Wilson, J. S., Sawyer, L. and James, M. N. G. (1983) Can. J. Chem., 61:1911. To a stirred solution of DMSO (160 mls) and acetic anhydride (20.0 ml, 212 mmol) was added the TPDS guanosine (21.0 g, 0.040 mol). The reaction was stirred for 36 hrs at room temperature and then cooled to 0° C. Cold EtOH (400 ml, 95%) was added and the reaction mixture further cooled to -78° C. in a dry ice/acetone bath. NaBH 4 (2.0 g, 1.32 mol.eq) was added. The reaction was allowed to come to -2° C., stirred at -2° C. for 30 mins, and again cooled to -78° C. This was repeated twice more. After addition of the NaBH 4 was complete, the reaction was stirred at ice temperature for 30 mins and then at RT for 1 hr. The reaction was taken up in EtOAc (11) and washed 2× with a saturated NaCl solution. The organic layer was dried over MgSO 4 and evaporated at RT. The residue was co-evaporated 2× with toluene and purified by silica gel column chromatography using CH 2 Cl 2 -MeOH (90:10) as the eluent. 6.02 g of pure product precipitate from the appropriate column fractions during evaporation of these fraction and an additional 11.49 g of product was obtained as a residue upon evaporated of the fractions.
L. N 2 -Isobutyryl-9-(2'-O-isobutyryl-3',5'- 1,1,3,3-tetraisopropyldisilox-1,3-diyl!-β-D-arabinofuranosyl)guanine.
9-(3',5'- 1,1,3,3-Tetraisopropyldisilox-1,3-diyl!-β-D-arabinofuranosyl)guanine (6.5 g, 0.01248 mol) was dissolved in anhydrous pyridine (156 ml) under argon. DMAP (9.15 g) was added. Isobutyric anhydride (6.12 ml) was slowly added and the reaction mixture stirred at RT overnight. The reaction mixture was poured into cold sat. NaHCO 3 (156 ml) and stirred for 10 min. The aqueous solution was extracted 3× with EtOAc (156 ml). The organic phase was washed 3× with sat. NaHCO 3 and evaporated to dryness at RT. The residue was co-evaporated with toluene at RT. The residue was purified by silica gel column chromatography using CH 2 Cl 2 -acetone (85:15) to yield 5.67 g (68%) of product.
M. N 2 -Isobutyryl-9-(2'-O-isobutyryl-β-D-arabinofuranosyl)guanine.
N 2 -Isobutyryl-9-(2'-isobutyryl-3',5'- 1,1,3,3-tetraisopropyldisilox-1,3-diyl!-β-D-arabinofuranosyl)guanine (9.83 g, 0.01476 mol) was dissolved in anhydrous THF (87.4 ml) at RT under argon. 1M N(nBu) 4 F in THF (29.52 ml, 2 eq.) was added and the mixture stirred for 1/2 hr. The reaction mixture was evaporated at RT and the residue purified by silica gel column chromatography using EtOAc-MeOH (85:15) to yield 4.98 g (80%) of product.
N. N 2 -Isobutyryl-9-(2'-O-isobutyryl-3',5'-di-O- tetrahydropyran-2-yl!-β-D-arabinofuranosyl)guanine.
N 2 -Isobutyryl-9-(2'-O-isobutyryl-β-D-arabinofuranosyl)guanine (4.9 g) was dissolved in anhydrous 1,4-dioxane (98 ml) at RT under argon. p-Toluenesulfonic acid monohydrate (0.97 g, 0.44 eq.) was added followed by 3,4-dihydro-2H-pyran, i.e. DHP, (9.34 ml, 8.8 sq.). The mixture was stirred for 2 hrs then cooled to ice temp and sat. NaHCO 3 (125 ml) was added to quench the reaction. The reaction mixture was extracted 3× with 125 ml portions of CH 2 Cl 2 and the organic phase dried over MgSO 4 . The organic phase was evaporated and the residue dissolved in a minimum, but sufficient amount to yield a clear liquid not a syrup, volume of CH 2 Cl 2 and dripped into 100 times the CH 2 Cl 2 volume of hexane. The precipitated was filtered to give 5.59 g (81.5%) of product.
O. N 2 -Isobutyryl-9-(3',5'-di-O- tetrahydropyran-2-yl!-β-D-arabinofuranosyl)guanine.
N 2 -Isobutyryl-9-(2'-O-isobutyryl-3',5'-di-O- tetrahydropyran-2-yl!-β-D-arabinofuranosyl)guanine (5.58 g) was dissolved in pyridine:MeOH:H 2 O (65:30:15, 52 ml) at RT. The solution was cooled to ice temp and 52 ml of 2N NaOH in EtOH-MeOH (95:15) was added slowly followed by stirring for 2 hrs at ice temp. Glacial AcOH was added to pH6. Sat. NaHCO 3 was then added to pH 7. The mixture was evaporated at RT and the residue co-evaporated with toluene. The residue was dissolved in EtOAc (150 ml) and wash 3× with sat. NaHCO 3 . The organic phase was evaporated and the residue purified by silica gel column chromatography using EtOAc-MeOH (95:5) to yield 3.85 g (78.3%) of product.
P. N 2 -Isobutyryl-9-(3',5'-di-O- tetrahydropyran-2-yl!-2'-O-trifluormethylsulfonyl-β-D-arabinofuranosyl)guanine.
N 2 -Isobutyryl-9-(3',5'-di-O- tetrahydropyran-2-yl!-β-D-arabinofuranosyl)guanine (3.84 g) was dissolved in anhydrous CH 2 Cl 2 (79 ml), anhydrous pyridine (5.0 ml) and 4-dimethylaminopyridine (2.93 g) at RT under argon. The solution was cooled to ice temp. and trifluoromethanesulfonic anhydride (1.99 ml) was slowly added with stirring. The mixture was stirred for 1 hr then poured into 100 ml of sat. NaHCO 3 . The aqueous phase was extracted 3× with cold CH 2 Cl 2 . The organic phase was dried over MgSO 4 , evaporated and co-evaporated with anhydrous CH 3 CN at RT to yield the crude product.
Q. N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-3',5'-di-O- tetrahydropyran-2-yl!-β-D-ribofuranosyl)guanine.
The crude product from Example 1-P, i.e. N 2 -isobutyryl-9-(3',5'-di-O- tetrahydropyran-2-yl!-2'-O-trifluormethylsulfonyl-β-D-arabinofuranosyl)guanine, was dissolved in anhydrous THF (113 ml) under argon at ice temp. 1M anhydrous N(nBu) 4 F (dried by co-evaporation with pyridine) in THF (36.95 ml) was added with stirring. After 1 hr a further aliquot of 1M N(nBu) 4 F in THF (36.95 ml) (10 mol. eq. total) was added. The mixture was stirred for 5 hrs at ice temp. and stored in a -30° C. freezer overnight. The reaction mixture was evaporated at RT and the residue dissolved in CH 2 Cl 2 (160 ml) and extracted 5× with deionized H 2 O. The organic phase was dried over MgSO 4 and evaporated. The residue was purified by silica gel column chromatography using EtOAc-MeOH (95:5) to yield 5.25 g of product.
R. N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-β-D-ribofuranosyl)guanine
N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-3',5'-di-O- tetrahydropyran-2-yl!-β-D-ribofuranosyl)guanine (3.85 g) was dissolved in MeOH (80 ml) at RT. 12.32 cm 3 of pre-washed Dowex 50W resin was added and the mixture stirred at RT for 1 hr. The resin was filtered and the filtrate evaporated to dryness. The resin was washed with pyridinetriethylamino-H 2 O (1:3:3) until clear. This filtrate was evaporated to an oil. The residues from the two filtrates were combined in H 2 O (200 ml) and washed 3× with CH 2 Cl 2 (100 ml). The aqueous phase was evaporated to dryness and the residue recrystallized from hot MeOH to yield a 0.299 g first crop of product as a white powder. The remaining MeOH solution was purified by silica gel column chromatography yielding a further crop of 0.783 g by elution with EtOH-MeOH (80:20).
S. N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-5'-O- 4,4'-dimethoxytrityl!-β-D-ribofuranosyl)guanine.
N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-β-D-ribofuranosyl)guanine (1.09 g) was dissolved in pyridine (20 ml) and triethylamine (0.56 ml) at RT under argon. 4,4'-Dimethoxytrityl chloride (1.20 g, 1.15 molar eq.) was added and the mixture stirred at RT for 5 hrs. The mixture was transferred to a separatory funnel and extracted with Et 2 O (100 ml). The organic phase was washed 3× with sat. NaHCO 3 (70 ml portions) and the aqueous phase back extracted 3× with Et 2 O. The combined organic phases were dried over MgSO 4 and triethylamine (4 ml) added to maintain the solution basic. The solvent was evaporated and the residue purified by silica gel column chromatography. The column was eluted with EtOAc-Et 3 N (100:1) and then EtOAc-MeOH-Et 3 N (95:5:1) to yield 1.03 g of product. 1 H-NMR (DMSO-d 6 ) δ 6.09 (dd, 1, H1', J 1-2 =2.61, J 1' ,F =16.2 Hz); δ 5.28 (ddd, 1, H2', J 2'-F =52.8 Hz); δ 4.38 (m, 1, H3', J 3' ,F =19.8 Hz).
T. N 2 -Isobutyzyl-9-(2'-deoxy-2'-fluoro-5'-O- 4,4'-dimethoxytrityl!)guanosine-3'-O-N,N-diisopropyl-β-cyanoethyl phosphoramidite.
N 2 -Isobutyryl-9-(2'-deoxy-2'-fluoro-5'-O- 4,4'-dimethoxytrityl!-β-D-ribofuranosyl)guanine (0.587 g) was dissolved in anhydrous CH 2 Cl 2 (31 ml) and diisopropylethylamine (0.4 ml) at RT under argon. The solution was cooled to ice temp and chloro(diisopropylamino)-β-cyanoethoxyphosphine (0.42 ml) was slowly added. The reaction was allowed to warm to RT and stirred for 3.5 hrs. CH 2 Cl 2 -Et 3 N (100:1, 35 ml) was added and the mixture washed 1× with sat. NaHCO 3 (6 ml). The organic phase was dried over MgSO 4 and evaporated at RT. The residue was purified by silica gel column chromatography using Hex-EtOAc-Et 3 N (75:25:1) for 2 column volumes, then Hex-EtOAc-Et 3 N (25:75:1) and finally EtOAc-Et 3 N. The product containing fractions were pooled and evaporated at RT. The resulting oil was co-evaporated 2× with CH 3 CN and placed on a vacuum pump overnight to dry. The resulting white solid was dissolved in CH 2 Cl 2 (3 ml) and dripped into stirring hexane (300 ml). The resulting precipitate was filtered and dried on a vacuum pump to yield 0.673 g (88%) of product. 31 P-NMR (CDCl 3 ) δ 150.5, 151.5.
EXAMPLE 2
Preparation of 2'-Deoxy-2'-cyano Modified Oligonucleotides
A. N 6 -Benzoyl- 2'-deoxy-2'-cyano-5'-O-(4,4'-dimethoxytrityl)! adenosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
2'-Deoxy-2'-cyanoadenosine is prepared by the free radical replacement of the 2'-iodo group of 2'-deoxy-2'-iodo-3',5'-O-(disiloxytetraisopropyl)-N6-benzoyladenosine according to a similar procedure described by K. E. B. Parkes and K. Taylor, Tetrahedron Letters 29:2995-2996 (1988). 2'-Deoxy-2'-iodoadenosine was prepared by R. Ranganathan as described in Tetrahedron Letters 15:1291-1294 (1977), and disilyated as described by W. T. Markiewicz and M. Wiewiorowski in Nucleic Acid Chemistry, Part 3, pp. 222-231, Townsend, L. B.; Tipson, R. S. eds. (J. Wiley and Sons, New York, 1986). This material is treated with hexamethylditin, AIBN, and t-butylisocyanate in toluene to provide protected 2'-deoxy-2'-cyanoadenosine. This material, after selective deprotection, is converted to its 5'-DMT-3'-phosphoramidite as described in Example 1A.
B. 2'-Deoxy-2'-cyano-5'-O-(4,4'-dimethoxytrityl)uridine-3'-O-(N,N-diisopropyl-β-cyanoethyl phosphoramidite).
2'-Deoxyuridine (or 5-methyluridine), 3',5'-disilylated as described above, is converted to the 2'-iodo derivative by triphenylphosphonium methyl iodide treatment as described by K. E. B. Parkes and K. Taylor, Tetrahedron Letters 29:2995-2996 (1988). Application of free radical reaction conditions as described by K. E. B. Parkes and K, Taylor, Tetrahedron Letters 29:2995-2996 (1988), provides the 2'-cyano group of the protected nucleoside. Deprotection of this material and subsequent conversion to the protected monomer as described above provides the requisite nucleic acid synthesizer material.
C. 2'-Deoxy-2'-cyano-5'-O-(4,4'-dimethoxytrityl)cytidine-3'-O-(N,N-diisopropyl-β-cyanoethyl phosphoramidite),
2'-Deoxy-2'-iodocytidine is obtained from the corresponding above described uridine compound via a conventional keto to amino conversion.
D. 2'-Deoxy-2'-cyano-5'-O-(4,4'-dimethoxytrityl)guanosine-3'-O-(N,N-diisopropyl-β-cyanoethyl phos-phoramidite).
2'-Deoxy-2'-cyanoguanosine is obtained by the displacement of the triflate group in the 2'-up position (arabino sugar) of 3',5'-disilylated N2-isobutrylguanosine. Standard deprotection and subsequent reprotection provides the title monomer.
EXAMPLE 3
Preparation of 2'-Deoxy-2'-(trifluoromethyl) Modified Oligonucleotides
The requisite 2'-deoxy-2'-trifluromethyribosides of nucleic acid bases A, G, U(T), and C are prepared by modifications of a literature procedure described by Q.-Y. Chen and S. W. Wu in the Journal of Chemical Society Perkin Transactions 2385-2387 (1989). Standard procedures, as described in Example 1A, are employed to prepare the 5'-DMT and 3'-phosphoramidites as listed below.
A. N 6 -Benzoyl- 2'-deoxy-2'-trifluoromethyl-5'-O-(4,4'-dimethoxytrityl)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethyl phosphoramidite).
B. 2'-Deoxy-2'-trifluoromethyl-5'-O-(4,4'-dimethoxytrityl)uridine-3'-O-(N,N-diisopropyl-β-cyanoethyl-phosphoramidite).
C. 2'-Deoxy-2'-trifluoromethyl-5'-O-(4,4'-dimethoxytrityl)cytidine-3'-O-(N,N-diisopropyl-β-cyanoethyl-phosphoramidite).
D. 2'-Deoxy-2'-trifluoromethyl-5'-O-(4,4'-dimethoxytrityl)guanosine-3'-O-(N,N-diisopropyl-β-cyano-ethylphosphoramidite).
EXAMPLE 4
Preparation of 2'-Deoxy-2'-(trifluoromethoxy) Modified Oligonucleotides
The requisite 2'-deoxy-2'-O-trifluoromethylribosides of nucleic acid bases A, G, U(T), and C are prepared by modifications of literature procedures described by B. S. Sproat, et al., Nucleic Acids Research 18:41-49 (1990) and H. Inoue, et al., Nucleic Acids Research 15:6131-6148 (1987). Standard procedures, as described in Example 1A, are employed to prepare the 5'-DMT and 3'-phosphoramidites as listed below.
A. N6-Benzoyl- 2'-deoxy-2'-(trifluoromethoxy)-5'-O-(4,4'-dimethoxytrityl)!adenosine-3'-O-(N,N-diisoporopyl-β-cyanoethylphosphoramidite).
B. 2'-Deoxy-2'-(trifluoromethoxy)-5'-O-(4,4'-dimethoxytrityl)uridine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
C. 2'-Deoxy-2'-(trifluoromethoxy)-5'-O-(4,4'-dimethoxytrityl)cytidine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
D. 2'-Deoxy-2'-(trifluoromethoxy)-5'-O-(4,4'-dimethoxytrityl)guanosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
EXAMPLE 5
Preparation of 2'-Deoxy-2'-(1-proproxy) Modified Oligonucleotides
The requisite 2'-deoxy-2'-O-propyl ribosides of nucleic acid bases A, G, U(T), and C are prepared by modifications of literature procedures described by B. S. Sproat, et al., Nucleic Acids Research 18:41-49 (1990) and H. Inoue, et al., Nucleic Acids Research 15:6131-6148 (1987). Standard procedures, as described in Example 1A, are employed to prepare the 5'-DMT and 3'-phosphoramidites as listed below.
A. N 6 -Benzoyl- 2'-deoxy-2'-(1-proproxy)-5'-O-(4,4'-dimethoxytrityl)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethyl phosphoramidite).
B. 2'-Deoxy-2'-(1-proproxy)-5'-O-(4,4'-dimethoxytrityl)uridine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
C. 2'-Deoxy-2'-(1-proproxy)-5'-O-(4,4'-dimethoxytrityl)cytidine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
D. 2'-Deoxy-2'-(1-proproxy)-5'-O-(4,4'-dimethoxytrityl)guanosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
EXAMPLE 6
Preparation of 2'-Deoxy-2'-(vinyloxy) Modified Oligonucleotides
The requisite 2'-deoxy-2'-O-vinyl ribosides of nucleic acid bases A, G, U(T), and C are prepared by modifications of literature procedures described by B. S. Sproat, et al., Nucleic Acids Research 18:41-49 (1990) and H. Inoue, et al., Nucleic Acids Research 15:6131-6148 (1987). In this case 1,2-dibromoethane is coupled to the 2'-hydroxyl and subsequent dehydrobromination affords the desired blocked 2'-vinyl nucleoside. Standard procedures, as described in Example 1A, are employed to prepare the 5'-DMT and 3'-phosphoramidites as listed below.
A. N 6 -Benzoyl- 2'-deoxy-2'-(vinyloxy)-5'-O-(4,4'-dimethoxytrityl)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
B. 2'-Deoxy-2'-(vinyloxy)-5'-O-(4,4'-dimethoxytrityl)uridine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
C. 2'-Deoxy-2'-(vinyloxy)-5'-O-(4,4'-dimethoxyltrityl)cytidine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
D. 2'-Deoxy-2'-(vinyloxy)-5'-O-(4,4'-dimethoxytrityl)guanosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
EXAMPLE 7
Preparation of 2'-Deoxy-2'-(allyloxy) Modified Oligonucleotides
The requisite 2'-deoxy-2'-O-allyl ribosides of nucleic acid bases A, G, U(T), and C are prepared by modifications of literature procedures described by B. S. Sproat, et al., Nucleic Acids Research 18:41-49 (1990) and H. Inoue, et al., Nucleic Acids Research 15:6131-6148 (1987). Standard procedures, as described in Example 1A, are employed to prepare the 5'-DMT and 3'-phosphoramidites as listed below.
A. N 6 -Benzoyl- 2'-deoxy-2'-(allyloxy)-5'-(4,4'-dimethoxytrityl)!adenosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphorsmidite).
B. 2'-Deoxy-2'-(allyloxy)-5'-O-(4,4'-dimethoxytrityl)-uridine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
C. 2'-Deoxy-2'-(allyloxy)-5'-O-(4,4'-dimethoxytrityl)-cytidine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
D. 2'-Deoxy-2'-(allyloxy)-5'-O-(4,4'-dimethoxytrityl)-guanosine-3'-O-(N,N-diisopropyl-β-cyanoethylphosphoramidite).
EXAMPLE 8
Preparation of 2'-Deoxy-2'-(methylthio), (methylsulfinyl) and (methylsulfonyl) Modified Oligonucleotides
A. 2'-Deoxy-2'-Methylthiouridine
2,2'-Anhydrouridine (15.5 g, 68.2 mmol) Rao, T. S. and Reese, C. B. (1989) J. Chem. Soc., Chem. Commun., 997!, methanethiol (15.7 g, 327 mmol), 1,1,3,3-tetramethylguanidine (39.2 g, 341 mmol) and dimethylforamide (150 ml), were heated together at 60° C. After 12 hr, the reaction mixture was cooled and concentrated under reduced pressure. The residual oil was purified by flash column chromatography on silica gel (300 g). Concentration of the appropriate, fractions, which were eluted with CH 2 Cl 2 -MeOH (9:1, v/v), and drying of the residue under high vacuum gave 2'-deoxy-2'-methylthiouridine as a pale yellow solid (14.11 g, 75.4%). Attempts to crystallize the solids from ethanol-hexanes (as reported by Imazawa, M., Ueda, T., and Ukita, T. (1975) Chem. Pharm. Bull., 23:604) failed and the material turned into a hygroscopic foam.
1 H NMR (Me 2 SO-d 6 ) δ 2.0 (3H, s, SCH 3 ), 3.34 (1H, dd, J 3' ,2' =54 Hz, 2'H), 3.59 (2H, br m, 5'CH 2 ), 3.84 (1H, m, 4'H), 4.2 (1H, dd, J 3' ,4' =2.2 Hz, 3'H), 5.15 (1H, t, 5'OH), 5.62 (1H, t, 3'OH), 5.64 (1H, d, J C6 ,C5 =8.2 Hz), 6.02 (1H, d, J 1' ,2' =6 Hz, 1'H), 7.82 (1H, d, J C5 ,C6 =8.2 Hz, C 6 H), 11.38 (1H, br s, NH).
B. 2,2'-Anhydro-5-Methyluridine
A mixture of 5-methyluridine (16.77 g, 69.2 mmol), diphenyl carbonate (17.8 g, 83.1 mmol) and sodium bicarbonate (100 mg) in hexamethylphosphoramide (175 ml) was heated to 150° C. with stirring until evolution of CO 2 ceased (approximately 1 hr). The reaction mixture was cooled and then poured into diethylether (11) while stirring to furnish a brown gum. Repeated washings with diethylether (4×250 ml) furnished a straw colored hygroscopic powder. The solid was purified by short column chromatography on silica gel (400 g). Pooling and concentration of appropriate fractions, which were eluted with CH 2 Cl 2 -MeOH (85:15, v/v) furnished the title compound as a straw colored solid (12 g, 77.3%) which crystallized from EtOH as long needles, m.p. 226°-227° C.
C. 2'-Deoxy-2'-Methylthio-5-Methyluridine
2.2'-Anhydro-5-methyluridine (17.02 g, 70.6 mmol), methanethiol (16.3 g, 339 mmol), 1,1,3,3-tetramethylguanidine (40.6 g, 353 mmol), and dimethylformamide (150 ml) were heated together at 60° C. After 12 hr, the products were cooled and concentrated under reduced pressure. The residual oil was purified by short silica gel (300 g) column chromatography. Concentration of appropriate fractions, which were eluted with CH 2 Cl 2 -MeOH (93:7, v/v), furnished the title compound as a white foam (15.08 g, 74.1%). Crystallization from EtOH-CH 2 Cl 2 furnished white needles.
D. 2'-Deoxy-2'-Methylsulfinyluridine
To a stirred solution of 2'-deoxy-2'methylthiouridine (1 g, 3.65 mmol) in EtOH (50 ml) was added a solution of m-chloroperbenzoic acid (50%, 1.26 g, 3.65 mmol in 50 ml EtOH) over a period of 45 min at 0° C. The solvent was removed under vacuum and the residue purified by short silica gel (30 g) column chromatography. Concentration of appropriate fractions, which were eluted with CH 2 Cl 2 -MeOH (75:25, v/v), afforded the title compound as a white solid (0.65 g, 61.4%). Crystallization from EtOH furnished white granules, m.p. 219°-221° C.
1 H NMR (Me 2 SO-d 6 ) δ 2.5(3H, s, SOCH 3 ), 3.56 (2H, br s, 5'CH 2 ), 3.8 (1H, m, 4'H), 3.91 (1H, m, 2'H), 4.57 (1H, m, 3'H), 5.2 (1H, br s, 5'OH), 5.75 (1H, d, C 5 H), 6.19 (1H, d, 3'OH), 6.35 (1H, d, 1'H), 7.88 (1H, d, C 6 H), 11.43 (1H, br s, NH).
E. 2'-Deoxy-2'-Methylsulfonyluridine
To a stirred solution of 2'-deoxy-2'-methyluridine (1 g, 3.65 mmol) in EtOH (50 ml) was added m-chloroperbenzoic acid (50%, 3.27 g, 14.6 mmol) in one portion at room temperature. After 2 hr., the solution was filtered to collect a white precipitate, which on washing (2×20 ml, EtOH and 2×20 ml Et 2 O) and drying furnished the title compound as a fine powder (0.76 g, 68%), m.p. 227°-228° C.
1 H NMR (Me 2 SO-d 6 ) δ 3.1 (3H, s, SO 2 CH 3 ), 3.58 (2H, m, 5'CH 2 ), 3.95 (1H, m, 2'H), 3.98 (1H, m, 4'H), 4.5 (1H, br s, 3'H), 5.2 (1H, br s, 5'OH), 5.75 (1H, d, C 5 H), 6.25 (1H, d, 3'OH), 6.5 (1H, d, 1'H), 7.8 (1H, d, C 6 H), 11.45 (1H, br s, NH).
F. 2'-Deoxy-5-O-(4,4'-Dimethoxytrityl)-2'-Methylthiouridine
To a stirred solution of 2'-deoxy-2'-methylthiouridine (1.09 g, 4 mmol)) in dry pyridine (10 ml) was added 4,4'-dimethoxytritylchloride (1.69 g, 5 mmol) and 4-dimethylaminopyridine (50mg) at room temperature. The solution was stirred for 12 hr and the reaction quenched by adding MeOH (1 ml). The reaction mixture was concentrated under vacuum and the residue dissolved in CH 2 Cl 2 (100 ml), washed with sat. aq. NaHCO 3 (2×50 ml), sat. aq. NaCl (2×50 ml), and dried (MgSO 4 ). The solution was concentrated under vacuum and the residue purified by silica gel (30 g) column Chromatography. Elution with CH 2 Cl 2 -MeOH:triethylamine (89:1:1, v/v) furnished the title compound as homogeneous material. Pooling and concentration of appropriate fractions furnished the 5'-O-DMT nucleoside as a foam (1.5 g, 66.5%).
1 H NMR (MeSO-d 6 ) δ 2.02 (3H, s, SCH 3 ), 3.15-3.55 (1H, m, 2'CH), 3.75 (6H, s, 2 OCH 3 ), 3.97 (1H, m, 4'H), 4.24 (1H, m, 3'H), 5.48 (1H, d, C 5 H), 5.73 (1H, d, 3'-OH), 6.03 (1H, d, C1'H), 6.82-7.4 (13H, m, ArH), 6.65 (1H, d, C 6 H), 11.4 (1H, br s, NH).
G. 2'-Deoxy-3'-O- (N,N-diisopropyl)-O-β-cyanoethylphosphoramide!-5'-O-(4,4'-dimethoxytrityl)-2'-Methylthiouridine
To a stirred solution of 2'-deoxy-5'-O-(4,4'-dimethoxytrityl)-2'-methylthiouridine (1.5 g, 2.67 mmol) in dry THF (25 ml) was added diisopropylethylamine (1.4 ml, 8 mmol) and the solution cooled to 0° C. N,N-diisopropyl-β-cyanoethylphosphoramidic chloride (1.26 ml, 5.34 mmol) was added dropwise over a period of 15 min. The reaction mixture was then stirred at room temperature for 2 hr. EtOAc (100 ml, containing 1% triethylamine) was added and the solution washed with sat NaCl (2×50 ml) and the organic layer dried over MgSO 4 . The solvent was removed under pressure and the residue purified by short silica gel (30 g) column chromatography. Elution with CH 2 Cl 2 :MeOH:triethylamine (98:1:1, v/v) furnished the product as a mixture of diastereoisomers. Evaporation of the appropriate fractions provided the title compound as a foam (1.32 g, 64.7%).
1 H NMR (CDCl 3 ) δ 2.0 and 2.02 (3H, 2s, SCH 3 ), 5.3 and 5.35 (1H, 2d, C 5 H), 6.23 (1H, d, 1'M), 7.8 and 7.78 (1H, 2d, C 6 H) and other protons. 31 P NMR (CDCl 3 ) δ 151.68 and 152.2 ppm.
H. 2'-Deoxy-3',5'-di-O-Acetyl-2'-Methylthiouridine
2'-Deoxy-2'-methylthiouridine (5.0 g, 18.24 mmol) and acetic anhydride (5.6 ml, 54.74 mmol) were stirred together in dry pyridine (30 ml) at room temperature for 12 hr. The products were then concentrated under reduced pressure and the residue obtained was purified by short silica gel column chromatography. The appropriate fractions, which were eluted with CH 2 Cl 2 :MeOH (9:1, v/v), were combined, evaporated under reduced pressure and the residue was crystallized from EtOH to give the title compound (6.0 g, 91.8%) as white needles, m.p. 132° C.
1 H NMR (CDCl 3 ) δ 2.17 (3H, s, SCH 3 ), 2.20 (6H, s, 2 COCH 3 ), 3.40 (1H, t, 2'H), 4.31-4.40 (3H, m, 4',5'H), 5.31 (1H, m, 3'H), 5.80 (1H, d, C 5 H), 6.11 (1H, d, 1'H), 7.45 (1H, d, C 6 H), 8.7 (1H, br s, NH).
I. 2'-Deoxy-3',5'-di-O-Acetyl-4-(1,2,4-triazol-1-yl)-2'-Methylthiouridine
Triethylamine (8.4 ml, 60.3 mmol) and phosphoryl chloride (1.2 ml, 12.9 mmol) were added to a stirred solution of 2'-deoxy-3',5'-di-O-acetyl-2'-methylthiouridine (4.6 g, 13 mmol) in CH 3 CN (50 ml). 1,2,4-Triazole (4.14 g, 59.9 mmol) was then added and the reactants were stirred together at room temperature. After 16 hr, triethylamine-water (6:1, v/v; 20 ml) followed by sat. aq. NaHCO 3 (100 ml) were added to the products and the resulting mixture was extracted with CH 2 Cl 2 (2×100 ml). The organic layer was dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by short silica gel column chromatography. The appropriate fractions, which were eluted with CH 2 Cl 2 :MeOH (9:1, v/v), were evaporated under vacuum and the residue was crystallized from EtOH to give the title compound (3.01 g, 56.4%) as pale needles, m.p. 127°-130° C.
1 H NMR (CDCl 3 ) δ 2.18 (6H, s, 2 COCH 3 ), 2.30 (3H, s, SCH 3 ), 3.67 (1H, m, 2'H), 4.38-4.50 (3H, m, 4',5'H), 5.17 (1H, t, 3'H), 6.21 (1H, d, 1'H), 7.08 (1H, d, C 5 H), 8.16 (1H,s, CH), 8.33 (1H, d, C 6 H), 9.25 (1H, s, CH).
J. 2'-Deoxy-2'-Methylthiocytidine
2'-Deoxy-3',5'-di-O-acetyl-4-(1,2,4-triazol-1-yl)-2-methylthiouridine (3.0 g, 7.5 mmol) was dissolved in a saturated solution of ammonia in MeOH (70 ml) and the solution was stirred at room temperature in a pressure bottle for 3 days. The products were then concentrated under reduced pressure and the residue was crystallized from EtOH:CH 2 Cl 2 to give the title compound (1.06 g, 51.7%) as crystals, m.p. 201° C.
1 H NMR (Me 2 SO-d 6 ) δ 1.95 (3H, s, SCH 3 ), 3.36 (1H, m, 2'H), 3.55 (2H, m, 5'CH 2 ), 3.82 (1H, m, 4'H), 4.18 (1H, dd, 3'H), 5.75 (1H, d, C 5 H), 6.1 (1H, d, 1'H), 7.77 (1H, d, C 6 H).
Anal. calcd. for C 10 H 15 N 3 O 4 S: C, 43.94; H, 5.53; N, 15.37; S, 11.73. Found, C, 44.07; H, 5.45; N, 15.47; S, 11.80.
K. 2'-Deoxy-N 4 -Benzoyl-2'-Methylthiocytidine
To a stirred solution of 2'-deoxy-2'-methylthiocytidine (0.86 g, 3.15 mmol) in dry pyridine (20 ml) was added trimethylchlorosilane (2.0 ml, 15.75 mmol), and stirring continued for 15 min. Benzoyl chloride (2.18 ml, 18.9 mmol) was added to the solution followed by stirring for 2 hr. The mixture was then cooled in an ice-bath and MeOH (10 ml) was added. After 5 mins., NH 4 OH (20 ml, 30% aq.) was added and the mixture stirred for 30 min. The reaction mixture was then concentrated under vacuum and the residue purified by short silica gel (70 g) column chromatography. Elution with CH 2 Cl 2 :MeOH (9:1, v/v), pooling of appropriate fractions and evaporation furnished the title compound (0.55 g, 46.6%) which crystallized from EtOH as needles, m.p. 193°-194° C.
L. N 4 -Benzoylamino-1- 2-Deoxy-5-(4,4'-Dimethoxytrityl)-2-Methylthio-β-D-Ribofuranosyl!pyrimidin-3(2H)-one (or 2'-Deoxy-N 4 -Benzoyl-5'-(4,4'-Dimethoxytrityl)-2'-Methylthiocytidine)
To a stirred solution of 2'-deoxy-N 4 -benzoyl-2'-methylthiocytidine (0.80 g, 2.12 mmol) in dry pyridine (10 ml) was added 4,4'-dimethoxytrityl chloride (1.16 g, 3.41 mmol) and 4-dimethylaminopyridine (10 mg) at room temperature. The solution was stirred for 2 hr and the products concentrated under vacuum. The residue was dissolved in CH 2 Cl 2 (70 ml), washed with sat. NaHCO 3 (50 ml), sat. NaCl (2×50 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by short silica gel (50 g) column chromatography. Elution with CH 2 Cl 2 :triethylamine (99:1, v/v), pooling and concentration of appropriate fractions furnished the title compound (1.29 g, 90%) as a White foam.
1 H NMR (DMSO-d 6 ) δ 2.1 (3H, s, SCH 3 ), 3.5 (1H, m, 2'H), 3.75 (6H, s, OCH 3 ), 4.15 (1H, m, 4'H) 4.4 (1H, t, 3'H), 5.74 (1H, br d, 3'OH), 6.15 (1H, d, C1'H) 6.8-8.0 (25H, m, ArH, and C 5 H), 8.24 (1H, d, C 6 H), 11.3 (1H, br s, NH).
M. 2'-Deoxy-N 4 -Benzoyl-3-O- (N,N-Diisopropyl)-β-Cyanoethylphosphoramide!-5'-O'(4,4'-Dimethoxytrityl)-2'-Methylthiocytidine
2'-Deoxy-N 4 -benzoyl-5'-(4,4'-dimethoxytrityl)-2'-methylthiocytidine (1.41 g, 2.07 mmol) was treated with diisopropylethylamine (1.4 ml, 8 mmol) and N,N-diisopropyl-β-cyanoethylphophoramide chloride (1.26 ml, 5.34 mmol) in dry THF (25 ml) as described in Example 8-G above. The crude product was purified by short silica gel (50 g) chromatography to furnish the title compound on elution with CH 2 Cl 2 :hexanes:triethylamine (89:10:1, v/v). The appropriate fractions were mixed and evaporated under pressure to give the title compound (1.30 g, 71%) as a white foam (mixture of diastereoisomers).
1 H NMR (CDCl 3 ) δ 2.31 (3H, s, SCH 3 ), 3.45-3.7 (3H, m, 2'H and 5'CH 2 ), 3.83 (6H, s, OCH 3 ), 4.27-4.35 (1H, m, 4'H), 4.6-4.8 (1H, m, 3'H), 6.35 (1H, 2d, 1'H), 6.82-7.8 (25H, m, ArH and C 5 H), 8.38 and 8.45 (1H, 2d, C 6 H) and other protons. 31 P NMR δ 151.03 and 151.08 ppm.
N. 2'-Deoxy-2'-Methylsulfinylcytidine
2'-Deoxy-2'-methylthiocytidine of Example 8-J was treated as per the procedure of Example 8-D to yield the title compound as a mixture of diastereoisomers having a complex 1 H NMR spectrum.
O. 2'-Deoxy-2'-Methylsulfonylcytidine
2'-Deoxy-2'-methylthiocytidine of Example 8-J was treated as per the procedure of Example 8-E to yield the title compound.
P. N 6 -Benzoyl-3',5'-di-O- Tetrahydropyran-2-yl!-2'-Deoxy-2'-Methylthioadenosine
N 6 -Benzoyl-9- 2'-O-trifluoromethylsulfonyl-3',5'-di-O-(tetrahydropyran-2-yl)-β-D-arabinofuranosyl!adenine from Example 1-D is prepared by treatment with methanethiol in the presence of tetramethylguanidine to yield the title compound.
Q. N 6 -Benzoyl-2'-Deoxy-2'-Methylthioadenosine
N 6 -Benzoyl-3',5'-di-O-(tetrahydropyran-2-yl)-2'-deoxy-2'-methylthioadenosine from Example 8-P is treated as per Example 1-F to yield the title compound.
R. N 6 -Benzoyl-2'-Deoxy-2'-Methylsulfinyladenosine
N 6 -Benzoyl-2'-deoxy-2'-methylthioadenosine from Example 8-Q was treated as per the procedure of Example 8-D to yield the title compound.
S. N 6 -Benzoyl-2'-Deoxy-2'-Methylsulfonyladenosine
N 6 -Benzoyl-2'-deoxy-2'-methylthioadenosine from Example 8-Q was treated as per the procedure of Example 8-E to yield the title compound.
T. N 2 -Isobutyryl-3',5'-di-O-(tetrahydropyran-2-yl)-2'-Deoxy-2'-Methylthioguanosine
N 2 -Isobutyryl-9-(3',5'-di-O- tetrahydropyran-2-yl!-2'-O-trifluoromethylsulfonyl-β-D-arabinofuranosyl)guanine from Example 1-P is treated with methanethiol in the presence of 1,1,3,3-tetramethylguanidine to yield the title compound.
U. N 2 -Isobutyryl-2'-Deoxy-2'-Methylthioguanosine
N 2 -Isobutyryl-3',5'-di-O-(tetrahydropyran-2-yl)-2'-deoxy-2'-methylthioguanosine is treated as per Example 1-R to yield the title compound.
V. N 2 -Isobutyryl-2'-Deoxy-2'-Methylsulfinylguanosine
N 2 -Isobutyryl-2'-Deoxy-2'-methylthioguanosine from Example 8-U was treated as per the procedure of Example 8-D to yield the title compound.
W. N 2 -Isobutyryl-2'-Deoxy-2'-Methylsulfonylguanosine
N 2 -Isobutyryl-2'-Deoxy-2'-methylthioguanosine from Example 8-U was treated as per the procedure of Example 8-E to yield the title compound.
X. 2'-Deoxy-5-O-(4,4'-Dimethoxytrityl)-2-Methylsulfinyluridine
2'-Deoxy-2'-methylsulfinyluridine from Example 8-D above is treated as per Example 8-F to yield the title compound.
Y. 2'-Deoxy-3'-O- (N,N-Diisopropyl)-O-β-cyanoethylphosphoramide!-5'-O-(4,4'-Dimethoxytrityl)-2'-Methylsulfinyluridine
2'-Deoxy-5'-O-(4,4'-dimethoxytrityl)-2-methylsulfinyluridine is treated as per Example 8-G to yield the title compound.
Z. N 6 -Benzoyl-2'-Deoxy-5-O-(4,4'-Dimethoxytrityl)-2'-Methylthioadenosine
N 6 -benzoyl-2'-Deoxy-2'-methylthioadenosine from Example 8-Q above is treated as per Example 8-F to yield the title compound.
AA. N 6 -Benzoyl-2'-Deoxy-3'-O- (N,N-Diisopropyl)-O-β-Cyanoethylphosphoramide!-5'-O-(4,4'-Dimethoxytrityl)-2'-Methylthioadenosine
N 6 -benzoyl-2'-Deoxy-5'-O-(4,4'-dimethoxytrityl)-2'-methylthioadenosine is treated as per Example 8-G to yield the title compound.
BB. 2'-Deoxy-N 2 -Isobutyryl-5-O-(4,4'-Dimethoxytrityl)-2'-Methylthioguanosine
2'-Deoxy-N 2 -isobutyryl-2'-methylthioguanosine from Example 8-U above is treated as per Example 8-F to yield the title compound.
CC. 2'-Deoxy-N 2 -Isobutyryl-3'-O- (N,N-Diisopropyl)-O-β-Cyanoethylphosphoramide!-5'-O-(4,4'-Dimethoxytrityl)-2'-Methylthioguanosine
2'-Deoxy-N 2 -isobutyryl-5'-O-(4,4'-dimethoxytrityl)-2'-methylthioguanosine is treated as per Example 8-G to yield the title compound.
DD. 2'-Deoxy-5-O-(4,4'-Dimethoxytrityl)-2'-Methylsulfonyluridine
2'-Deoxy-2'-methylsulfonyluridine from Example 8-E above is treated as per Example 8-F to yield the title compound.
EE. 2'-Deoxy-3'-O- (N,N-Diisopropyl)-O-β-Cyanoethylphosphoramide!-5'-O-(4,4'-Dimethoxytrityl)-2'-Methylsulfinyluridine
2'-Deoxy-5'-O-(4,4'-dimethoxytrityl)-2'-methylsulfinyluridine is treated as per Example 8-G to yield the title compound.
EXAMPLE 9
Chemical conversion of an thymine or cytosine (pyrimidine type base) to its β-D-2'-deoxy-2'-substituted erythro-pentofuranosyl nucleoside; 2'-substituted ribosylation).
The thymine or cytosine type analogs are trimethylsilylated under standard conditions such as hexamethyldisilazane (HMDS) and an acid catalyst (ie. ammonium chloride) and then treated with 3,5-O-ditoluoyl-2-deoxy-2-substituted-α-D-erythro-pentofuranosyl chloride in the presence of Lewis acid catalysts (ie. stannic chloride, iodine, boron tetrafluoroborate, etc.). A specific procedure has recently been described by J. N. Freskos, Nucleosides & Nucleotides 8:1075-1076 (1989) in which copper (I) iodide is the catalyst employed.
EXAMPLE 10
Chemical conversion of an adenine or guanine (purine type base) to its β-D-2'-deoxy-2'-substituted erythro-pentofuranosyl nucleoside; 2'-substituted ribosylation).
The protected purine type analogs are converted to their sodium salts via sodium hydride in acetonitrile and are then treated with 3,5-O-ditoluoyl-2-deoxy-2-substituted-α-D-erythro-pentofuranosyl chloride at ambient temperature. A specific procedure has recently been described by R. K. Robins et al., Journal of American Chemical Society 106:6379 (1984).
EXAMPLE 11
Conversion of 2'-deoxy-2-substituted thymidines to the corresponding 2'-deoxy-2'-substituted cytidines (chemical conversion of an pyrimidine type 4-keto group to an 4-amino group).
The 3',5'-sugar hydroxyls of the 2'-modified nucleoside types are protected by acyl groups such as toluoyl, benzoyl, p-nitrobenzoyl, acetyl, isobutryl, trifluoroacetyl, etc. using standards conditions of the acid chlorides or anhydrides and pyridine/dimethylaminopyridine solvent and catalyst. The protected nucleoside is now chlorionated with thionyl chloride or phosphoryl chloride in pyridine or other appropriate basic solvents. The pyrimidine type 4-chloro groups or now displaced with ammonium in methanol. Deprotection of the sugar hydroxyls also takes place. The amino group is benzoylated by the standard two-step process of complete benzylation (sugar hydroxyls and amino group) and the acyls are selectively removed by aqueous sodium hydroxide solution. Alternatively, the in situ process of first treating the nucleoside with chlorotrimethylsilane and base to protect the sugar hydroxyls from subsequent acylation may be employed. K. K. Ogilvie, Can J. Chem. 67:831-839 (1989). Another conversion approach is to replace the pyrimidine type 4-chloro group with an 1,2,4-triazolo group which remains intact throughout the oligonucleotide synthesis on the DNA synthesizer and is displaced by ammonium during the ammonium hydroxide step which removes the oligonucleotide from the CPG support and deprotection of the heterocycles. Furthermore, in many cases the pyrimidine type 4-chloro group can utilized as just described and replaced at the end of the oligonucleotide synthesis.
EXAMPLE 12
Procedure for the attachment of 2'-deoxy-2'-substituted 5'-dimethoxytriphenylmethyl ribonucleosides to the 5'-hydroxyl of nucleosides bound to CPG support.
The 2'-deoxy-2'-substituted nucleosides that will reside in the terminal 3'-position of certain antisense oligonucleotides is protected as their 5'-DMT (the cytosine and adenine exocyclic amino groups are benzoylated and the guanine amino is isobutyrylated) and treated with trifluoro-acetic acid/bromoacetic acid mixed anhydride in pyridine and dimethylaminopyridine at 50° C. for five hours. The solution is evaporated under reduced pressure to a thin syrup which is dissolved in ethyl acetate and passed through a column of silica gel. The homogenous fractions were collected and evaporated to dryness. A solution of 10 ml of acetonitrile, 10 micromoles of the 3'-O-bromomethylester modified pyrimidine nucleoside, and one ml of pyridine/dimethylaminopyridine (1:1) is syringed slowly (60 to 90 sec) through a one micromole column of CPG thymidine (Applied Biosystems, INC.) that had previously been treated with acid according to standard conditions to afford the free 5'-hydroxyl group. Other nucleoside bound CPG columns could be employed. The eluent is collected and syringed again through the column. This process is repeated three times. The CPG column is washed slowly with 10 ml of acetonitrile and then attached to an ABI 380B nucleic acid synthesizer. Oligonucleotide synthesis is now initiated. The standard conditions of concentrated ammonium hydroxide deprotection that cleaves the thymidine ester linkage from the CPG support also cleaves the 3',5' ester linkage connecting the pyrimidine modified nucleoside to the thymidine that was initially bound to the CPG nucleoside. In this manner, any 2'-substituted nucleoside or generally any nucleoside with modifications in the heterocycle and/or sugar can be attached at the very 3'-end of an oligonucleotide sequence.
EXAMPLE 13
Procedure for the conversion of 2'-deoxy-2'-substituted ribonucleoside-5'-DMT-3'-phosphoramidites into oligonucleotides.
The polyribonucleotide solid phase synthesis procedure of B. S. Sproat, et al., Nucleic Acids Research 17:3373-3386 (1989) is utilized to prepare the 2'-modified oligonucleotides.
Oligonucleotides of the sequence CGA CTA TGC AAG TAC having 2'-deoxy-2'-fluoro substituent nucleotides were incorporated at various positions within this sequence. In a first oligonucleotide each of the adenosine nucleotides at positions 3, 6, 10, 11 and 14 (counted in a 5' to 3' directed) were modified to include a 2'-deoxy-2'-fluoro moiety. In a further oligonucleotide, the adenosine and the uridine nucleotides at positions 3, 5, 6, 7, 10, 11, 13 and 14 were so modified. In even a further oligonucleotide, the adenosine, uridine and cytidine nucleotides at positions 1, 3, 4, 5, 6, 7, 9, 10, 11, 13 and 14 were so modified and in even a further oligonucleotide, the nucleotides (adenosine, uridine, cytidine and guanosine) at every position was so modified. Additionally an oligonucleotide having the sequence CTC GTA CCT TCC GGT CC was prepared having adenosine, uridine and cytidine nucleotides at positions 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 15 and 16 also modified to contain 2'-deoxy-2'-fluoro substituent moieties.
Various oligonucleotides were prepared that incorporated nucleotides having 2'-deoxy-2'-methylthio substituents. For ascertaining the coupling efficiencies of 2'-deoxy-2'-methylthio bearing nucleotides into oligonucleotides, the trimer TCC and the tetramer TUU U were synthesized. In the trimer, TCC, the central cytidine nucleotide (the second nucleotide) included a 2'-deoxy-2'-methylthio substituent. In the tetramer, each of the Uridine nucleotides included a 2'-deoxy-2'-methylthio substituent. In further oligonucleotides, 2'-deoxy-2'-methylthio substituent bearing nucleotides were incorporated within the oligonucleotide sequence in selected sequence positions. Each of the nucleotides at the remaining sequence positions incorporated a 2'-O-methyl substituent on its nucleotide. Thus all of the nucleotides within the oligonucleotide included a substituent group thereon, either a 2'-deoxy-2'-methylthio substituent or a 2'-O-methyl substituent. These oligonucleotides are: GAG CUC CCA GGC having 2'-deoxy-2'-methylthio substituents at positions 4, 5, 6, 7 and 8; CGA CUA UGC AAG UAC having 2'-deoxy-2'-methylthio substituents at positions 1, 4, 5, 7, 9 and 13; UCC AGG UGU CCG AUC having 2'-deoxy-2'-methylthio substituents are positions 1, 2, 3, 7, 9, 10, 11 and 14; TCC AGG CCGUUU C having 2'-deoxy-2'-methylthio substituents at positions 10, 11 and 12; and TCC AGG TGT CCC C having 2'-deoxy-2'-methylthio substituents at positions 10, 11 and 12.
EXAMPLE 14
Preparation of 2'-Deoxy-2'-fluoro Modified Phosphorothioates Oligonucleotides.
2'-Deoxy-2'-substituted 5'-DMT nucleoside 3'-phosphoramidites prepared as described in Examples 1-7 were inserted into sequence-specific oligonucleotide phosphorothioates as described by S. Beaucage et al., Journal of American Chemical Society 112:1253-1255 (1990) and B. S. Sproat, et al., Nucleic Acids Research 17:3373-3386 (1989).
Oligonucleotides of the sequence CGA CTA TGC AAG TAC having phosphorothioate backbone linkages and 2'-deoxy-2'-fluoro substituent nucleotides were incorporated at various positions within this sequence. In a first oligonucleotide each of the backbone linkages was a phosphorothioate linkage and each of the adenosine, uridine and cytidine nucleotides at positions 1, 3, 4, 5, 6, 7, 9, 10, 11, 13 and 14 (counted in a 5' to 3' directed) were modified to include a 2'-deoxy-2'-fluoro moiety. In a further oligonucleotide each of the backbone linkages was a phosphorothioate linkages and the nucleotides (adenosine, uridine, cytidine and guanosine) at every position were modified to include a 2'-deoxy-2'-fluoro moiety.
EXAMPLE 15
Preparation of 2'-Deoxy-2'-fluoro Modified Phosphate Methylated Oligonucleotides.
The protection, tosyl chloride mediated methanolysis, and mild deprotection described by L. H. Koole et al., in the Journal of Organic Chemistry 54:1657-1664 (1989), is applied to 2'-substituted oligonucleotides to afford phosphate-methylated 2'-substituted oligonucleotides.
EXAMPLE 16
Hybridization Analysis.
A. Evaluation of the thermodynamics of hybridization of 2'-modified oligonucleotides.
The ability of the 2'-modified oligonucleotides to hybridize to their complementary RNA or DNA sequences was determined by thermal melting analysis. The RNA complement was synthesized from T7 RNA polymerase and a template-promoter of DNA synthesized with an Applied Biosystems, Inc. 380B RNA species was purified by ion exchange using FPLC (LKB Pharmacia,Inc.). Natural antisense oligonucleotides or those containing 2'-modifications at specific locations were added to either the RNA or DNA complement at stoichiometric concentrations and the absorbance (260 nm) hyperchromicity upon duplex to random coil transition was monitored using a Gilford Response II spectrophotometer. These measurements were performed in a buffer of 10 mM Na-phosphate, pH 7.4, 0.1 mM EDTA, and NaCl to yield an ionic strength of 10 either 0.1M or 1.0M. Data was analyzed by a graphic representation of 1/T m vs ln Ct!, where Ct! was the total oligonucleotide concentration. From this analysis the thermodynamic para-meters were determined. Based upon the information gained concerning the stability of the duplex of heteroduplex formed, the placement of nucleotides containing 2'-deoxy-2'-substituents into oligonucleotides were assessed for their effects on helix stability. Modifications that drastically alter the stability of the hybrid exhibit reductions in the free energy (delta G) and decisions concerning their usefulness as antisense oligonucleotides were made.
As is shown in the following Table 1, the incorporation of 2'-deoxy-2'-fluoro nucleotides into oligonucleotides resulted in significant increases in the duplex stability of the modified oligonucleotide strand (the antisense strand) and its complementary RNA strand (the sense strand). In both phosphodiester backbone and phosphorothioate backbone oligonucleotides, the stability of the duplex increased as the number of 2'-deoxy-2'-fluoro containing nucleotides in the antisense strand increased. As is evident from Table 1, without exception, the addition of a 2'-deoxy-2'-fluoro bearing nucleotide, irrespective of the individual substituent bearing nucleotide or irrespective of the position of that nucleotide in the oligonucleotide sequence, resulted in a increase in the duplex stability.
In Table 1, the underline nucleotides represent nucleotides that include a 2'-deoxy-2'-fluoro substituent. The non-underlined nucleotides are normal nucleotides. The oligonucleotides prefaced with the designation "ps" have a phosphorothioate backbone. Unlabeled oligonucleotides are normal phosphodiester backboned oligonucleotides.
TABLE 1__________________________________________________________________________EFFECTS OF 2'-DEOXY-2'-FLUORO MODIFICATIONS ON DNA(ANTISENSE)RNA(SENSE) DUPLEX STABILITY G°37 G°37 Tm(°(C.)/Antisence Sequence (kcal/mol) (kcal/mol) Tm(°C.) Tm(°C.) subst__________________________________________________________________________CGA CTA TGC AAG TAC -10.11 ± 0.04 45.1CG A CT A TGC -13.61 ± 0.08 -3.50 ± 0.09 53.0 +7.9 +1.6CG A C UA UG C AAG UAC -16.18 ± 0.08 -6.07 ± 0.09 58.9 +13.8 +1.7 CG A CUA UG C AAG UAC -19.85 ± 0.05 -9.74 ± 0.06 65.2 +20.1 +1.8ps(CGA CTA TGC AAG TAC) -7.58 ± 0.06 33.9 -11.2ps( CG A CUA -15.90 ± 0.34 -8.32 ± 0.34 60.9 27.0 +2.5CTC GTA CCT TCC GGT CC -14.57 ± 0.13 61.6 CUC G UA CCU UCC GG U CC -27.81 ± 0.05 -13.24 ± 0.14 81.6 +20.0 +1.4__________________________________________________________________________
As is evident from Table 1, the duplexes formed between RNA and an oligonucleotides containing 2'-deoxy-2'-fluoro substituted nucleotides exhibited increased binding stability as measured by the hybridization thermodynamic stability. Delta Tm's of greater than 20° C. were measured. By modifying the backbone to a phosphorothioate backbone even greater delta Tm's were observed. In this instance delta Tm's greater than 31° C. were measured. These fluoro substituted oligonucleotides exhibited a consistent and additive increase in the thermodynamic stability of the duplexes formed with RNA. While we do not wish to be bound by theory, it is presently believed that the presence of the 2'-fluoro substituent results in the sugar moiety of 2'-fluoro substituted nucleotide assuming substantially a 3'-endo conformation and this results in the oligonucleotide-RNA duplex assuming an A-type helical conformation.
B. Fidelity of hybridization of 2'-modified oligonucleotides
The ability of the 2'-modified antisense oligonucleotides to hybridize with absolute specificity to the targeted mRNA was shown by Northern blot analysis of purified target mRNA in the presence of total cellular RNA. Target mRNA was synthesized from a vector containing the cDNA for the target mRNA located downstream from a T7 RNA polymerase promoter. Synthesized mRNA was electrophoresed in an agarose gel and transferred to a suitable support membrane (ie. nitrocellulose). The support membrane was blocked and probed using 32 P!-labeled antisense oligonucleotides. The stringency was determined by replicate blots and washing in either elevated temperatures or decreased ionic strength of the wash buffer. Autoradiography was performed to assess the presence of heteroduplex formation and the autoradiogram quantitated by laser densitometry (LKB Pharmacia, Inc.). The specificity of hybrid formation was determined by isolation of total cellular RNA by standard techniques and its analysis by agarose electrophoresis, membrane transfer and probing with the labeled 2'-modified oligonucleotides. Stringency was predetermined for the unmodified antisense oligonucleotides and the conditions used such that only the specifically targeted mRNA was capable of forming a heteroduplex with the 2'-modified oligonucleotide.
C. Base-Pair Specificity of Oligonucleotides and RNA
Base-pair specificity of 2-deoxy-2'-fluoro modified oligonucleotides with the RNA complement (a "Y strand") was determined by effecting single base-pair mismatches and a bulge. The results of these determinations are shown in Table 2. An 18 mer "X strand" oligonucleotide containing 14 adenosine, uridine and cytidine nucleotides having a 2'-deoxy-2'-fluoro substituent was hybridized with the RNA complement "Y strand" in which the 10 position was varied. In Table 2, the underline nucleotides represent nucleotides that include a 2'-deoxy-2'-fluoro substituent.
TABLE 2__________________________________________________________________________EFFECTS OF SINGLE BASE MISMATCHES ON 2'-DEOXY-2'-FLUOROMODIFIED DNA · RNA DUPLEX STABILITY base-pair G°37 G°37Y type (kcalol) (kcal/mol) Tm(°C.) Tm(°C.)__________________________________________________________________________X strand: deoxy(CTC GTA CCT TTC CGG TCC)Y strand: ribo(.sup.3' GAG CAU GGY AAG GCC AGG.sup.5')A Watson-Crick -14.57 ± 0.13 61.6C T--C mismatch -12.78 ± 0.11 1.79 ± 0.17 54.4 -7.2G T--G mismatch -16.39 ± 0.25 -1.82 ± 0.28 61.7 0.1U T--U mismatch -13.48 ± 0.17 1.09 ± 0.22 55.9 -5.7none bulged T -14.86 ± 0.35 -0.284 ± 0.37 59.4 -2.2X strand: deoxy( CUC G UA CCU UUC CGG UCC)Y strand: ribo(.sup.3' GAG CAU GGY AAG CCC AGG.sup.5')A Watson-Crick -27.80 ± 0.05 81.6C U--C mismatch -21.98 ± 0.26 5.82 ± 0.28 73.8 -7.8G U--G mismatch -21.69 ± 0.16 6.12 ± 0.17 77.8 -3.8U U--U mismatch -18.68 ± 0.15 9.13 ± 0.16 73.6 -8.0none bulged U -22.87 ± 0.27 4.94 ± 0.27 75.5 -6.2__________________________________________________________________________
As is evident from Table 2, the 2'-deoxy-2'-fluoro modified oligonucleotide formed a duplex with the RNA complement with greater specificity than a like sequenced unmodified oligonucleotide.
EXAMPLE 17
Nuclease Resistance
A. Evaluation of the resistance of 2'-modified oligonucleotides to serum and cytoplasmic nucleases.
Natural phosphorothioate, and 2-modified oligonucleotides were assessed for their resistance to serum nucleases by incubation of the oligonucleotides in media containing various concentrations of fetal calf serum or adult human serum. Labeled oligonucleotides were incubated for various times, treated with protease K and then analyzed by gel electrophoresis on 20% polyacrylamine-urea denaturing gels and subsequent autoradiography. Autoradiograms were quantitated by laser densitometry. Based upon the location of the modifications and the known length of the oligonucleotide it was possible to determine the effect on nuclease degradation by the particular 2'-modification. For the cytoplasmic nucleases, a HL60 cell line was used. A post-mitochondrial supernatant was prepared by differential centrifugation and the labeled oligonucleotides were incubated in this supernatant for various times. Following the incubation, oligo-nucleotides were assessed for degradation as outlined above for serum nucleolytic degradation. Autoradiography results were quantitated for comparison of the unmodified, the phosphorothioates, and the 2'-modified oligonucleotides. Utilizing these test systems, the stability of a 15-mer oligonucleotide having 2-deoxy-2'-fluoro substituted nucleotides at positions 12 and 14 and a phosphorothioate backbone was investigated. As a control, an unsubstituted phosphodiester oligonucleotide was 50% degraded within 1 hr and 100% degraded within 20 hours. In comparison for the 2'-deoxy-2'-fluoro substituted oligonucleotide having the phosphorothioate backbone, degradation was limited to less than 10% after 20 hours.
B. Evaluation of the resistance of 2'-modified oligonucleotides to specific endo- and exo-nucleases.
Evaluation of the resistance of natural and 2'-modified oligonucleotides to specific nucleases (ie, endonucleases, 3',5'-exo-, and 5',3'-exonucleases) was done to determine the exact effect of the modifications on degradation. Modified oligonucleotides were incubated in defined reaction buffers specific for various selected nucleases. Following treatment of the products with proteinase K, urea was added and analysis on 20% poly-acrylamide gels containing urea was done. Gel products were visualized by staining using Stains All (Sigma Chemical Co.). Laser densitometry was used to quantitate the extend of degradation. The effects of the 2'-modifications were determined for specific nucleases and compared with the results obtained from the serum and cytoplasmic systems.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 7(2) INFORMATION FOR SEQ ID NO: 1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1:CGACTATGCAAGTAC15(2) INFORMATION FOR SEQ ID NO: 2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2:CGACUAUGCAAGUAC15(2) INFORMATION FOR SEQ ID NO: 3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3:CTCGTACCTTCCGGTCC17(2) INFORMATION FOR SEQ ID NO: 4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4:CUCGUACCUUCCGGUCC17(2) INFORMATION FOR SEQ ID NO: 5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 5:CTCGTACCTTTCCGGTCC18(2) INFORMATION FOR SEQ ID NO: 6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 6:GAGCAUGGYAAGGCCAGG18(2) INFORMATION FOR SEQ ID NO: 7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18(B) TYPE: nucleic(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iv) ANTI-SENSE: yes(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 7:CUCGUACCUUUCCGGUCC18__________________________________________________________________________
|
Compositions and methods are provided for the treatment and diagnosis of diseases amenable to modulation of the production of selected proteins. In accordance with preferred embodiments, oligonucleotides and oligonucleotide analogs are provided which are specifically hybridizable with a selected sequence of RNA or DNA wherein at least two of the 2'-deoxyfuranosyl moieties of the nucleoside unit is modified. Treatment of HIV, herpes virus, papillomavirus and other infections is provided.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part and claims the priority of U.S. Patent Application No. 61/147,158, entitled “Mobile Water Recirculation System For Surface Cleaning Apparatus”, filed Jan. 26, 2009, the contents of which are incorporated herein in their entirety. This application is related to U.S. Pat. No. 7,255,116, entitled “Stripe Removal System”, issued Aug. 14, 2007, U.S. patent application Ser. No. 11/340,738, entitled, “Transportable Holding Tank For Stripe Removal System”, filed Jan. 26, 2006, and U.S. patent application Ser. No. 11/340,104, entitled “Mobile Mark Removal System”, filed Jan. 26, 2006, the contents of which are incorporated herein by reference.
FIELD OF INVENTION
The present invention generally relates to water treatment systems, and more particularly to a closed loop water treatment system that is particularly suited for surface cleaning apparatus.
BACKGROUND INFORMATION
Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment processes is to remove existing contaminants in the water, or reduce the concentration of such contaminants so the water becomes fit for its desired end-use. One such use can be returning water that has been used back into the natural environment without adverse ecological impact.
The processes that have been suggested for use in treating water for solids separation include physical processes such as settling and filtration, and chemical processes such as disinfection and coagulation.
Biological processes have also been employed in the treatment of water, and these processes may include, for example, aerated lagoons, activated sludge or slow sand filters.
Surface cleaning apparatus such as pressure washers are useful for cleaning a variety of objects. Such devices require a clean supply of water for proper operation, but create wastewater by entraining solids from the cleaned surface into the used source water. Although there are many types of pressure washing systems, a typical system utilizes an engine that powers a pump. The inlet side of the pump is connected to a low pressure water source such as a tank or a municipal water supply, while the high pressure side of the pump is connected to a high pressure hose and wand for controlling the flow of high pressure water generated by the pump. The high pressure water is directed at a surface to dislodge dirt, paint and the like, and the water is generally allowed to drain into the storm sewer.
Ultra-high pressure washers, supplying more than 25,000 P.S.I. are also known. These systems include a large engine, typically diesel, which operates a large multi-cylinder pump to generate high volumes of water at ultra-high pressures. The ultra-high pressure water is directed through piping and/or hoses to various types of blast heads suitable for controlling the flow and direction of the ultra-high pressure water. One particular use for ultra-high pressure water devices is the removal of stripes or other markings from road surfaces. When polymers such as paint or plastic are used for roadway marking, the surface of the pavement is penetrated from ⅛-⅜ inch; whereby water blasting is the only known method of removing the stripe material from below the surface without removing a portion of the roadway surface. Ultra-high pressure water washers are also utilized for removing paint from ships, cleaning industrial facilities, removing graffiti, removing rubber from aircraft runways and demolition.
One problem associated with both low and ultra-high pressure water cleaning equipment is maintaining an adequate supply of clean water for continuous operation of the system. Dirty or contaminated water causes numerous problems with water cleaning equipment such as excessive pump wear, clogged filters, nozzles, screens and the like. Because cleaning often needs to take place away from municipal water supplies, water is often transported to the cleaning site. Because the water cleaning equipment requires large volumes of water to be effective, additional equipment is needed to haul in tanks of water. Alternatively, cleaning must be stopped so that additional water may be obtained.
Recovery and disposal of the water is another problem facing water cleaning equipment users. Demolition or even the mere cleaning of surfaces results in the water becoming contaminated with dirt and debris. This problem is particularly exacerbated with ultra high pressure water cleaning equipment which breaks dirt and debris up into particles small enough to remain suspended within the water indefinitely. Therefore, the contaminated water should be properly recovered and thereafter cleaned or contained before it can be disposed of.
Industrial systems that utilize filter belts are also known to be used for solid/liquid separation processes, particularly the dewatering of sludges in the chemical industry, mining and water treatment. The process of filtration is primarily obtained by passing a pair of filtering cloths and belts through a system of rollers. The feed sludge to be dewatered is introduced from a hopper between two filter cloths (supported by perforated belts) which pass through a convoluted arrangement of rollers. As the belts are fed through the rollers, water is squeezed out of the sludge. When the belts pass through the final pair of rollers in the process, the filter cloths are separated and the filter cake is scraped off into a suitable container. Water sprays are typically utilized to clean the filter cloth before it is reused. The water spray is reclaimed to be reprocessed or diverted to a drain for disposal. However, in these systems it is typically the solid filter cake that the user is interested in recovering and not the water that was carrying the solid particles, and thus the water typically remains dirty and is discarded to the drain.
Therefore, there is a need in the art for a water recirculation system that is suitable for applications such as high pressure or ultra-high pressure water cleaning equipment. The water recirculation system should provide a predetermined amount of clean water to start the cleaning operation. The water recirculation system should recover the dirty and contaminated water expelled during the cleaning process for removal of dirt and debris so that the water can be recirculated through the pressure cleaning equipment. The water recirculation system should be efficient enough to recirculate a sufficient volume of water for continuous operation of the water cleaning system. The water recirculation system should retain the dirt and debris for proper disposal. The water recirculation system should be compact enough to fit on a mobile frame that may also contain the high or ultra-high pressure water cleaning equipment.
There is also a need in the art for a water filtration system that is suitable for municipal, industrial and private uses. The water filtration system should utilize a continuous filter belt in combination with a settling tank for water containing a coagulant. The filter belt should be submerged within the settling tank a predetermined distance to control the hydrostatic head pressure utilized to push the debris containing water through the filter belt to limit the adhesion of the particles to the filter belt so that vacuum can be utilized to clean the filter belt for continuous use. The filter belt should be sized and the head pressure selected to provide a desired volume of cleaned water. The water can then be used as is or supplied to additional equipment or processes for further cleaning.
Thus, the present invention provides a water recirculation system for stationary or mobile applications and is particularly suited for surface cleaning apparatus and the like which overcomes the disadvantages of the prior art systems.
SUMMARY OF THE INVENTION
The present invention relates generally to an environmentally sensitive mobile cleaning system, and more specifically relates to a closed loop water recirculation system for high or ultra-high pressure mobile cleaning apparatus. The water recirculation system works in combination with a mobile pressure cleaning apparatus for cleaning surfaces while minimizing water usage and containing contaminants before they enter a storm water drain system. The system includes a water tank sized to contain an established volume of fluid sufficient to circulate through the system, a pump to pressure the fluid to a cleaning head, a vacuum system to return the contaminated fluid to the system, and a filter means to remove the contaminants from the fluid so that clean fluid can be reintroduced to the cleaning head. The method comprises the steps of increasing the pressure of a fixed volume of fluid in a closed-loop system, jetting or blasting the surface with the pressurized fluid, vacuuming the blasted fluid into the system, and removing the contaminants from the fluid.
Accordingly, it is an objective of the present invention to provide an environmentally sensitive cleaning system.
It is a further objective of the present invention to provide a mobile water recirculation system for surface cleaning apparatus.
It is yet a further objective of the present invention to provide a mobile water recirculation system for surface cleaning apparatus that reduces particulate size within the recirculated water to less than 1 micron.
It is another objective of the instant invention to provide a novel sediment tank arrangement.
It is yet another objective of the instant invention to provide a mobile water recirculation system for surface cleaning apparatus that includes a coagulant injection system.
It is still yet another objective of the instant invention to provide a mobile water recirculation system for surface cleaning apparatus that includes a continuous belt type filter.
It is yet a further objective of the instant invention to provide a method of continuously cleaning water to remove suspended solids therefrom.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a block diagram that illustrates one embodiment of the mobile water recirculation system for surface cleaning apparatus of the instant invention;
FIG. 2A is a top perspective view illustrating one embodiment of the vacuum tank illustrated in FIG. 1 ;
FIG. 2B is a top perspective view illustrating one embodiment of the vacuum tank illustrated in FIG. 1 ;
FIG. 3 is a top perspective view of one embodiment of the sediment tank illustrated in FIG. 1 ;
FIG. 4 is a top perspective view of one embodiment of the continuous belt filter;
FIG. 5 shows the mobile water recirculation system mounted on a mobile truck frame;
FIG. 6 is a section view of the sediment tank illustrating separation of the solids suspended within the water.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.
Referring generally to FIGS. 1 and 5 , a mobile water recirculation system 10 for surface cleaning apparatus is illustrated. The preferred embodiment of the water recirculation system generally includes a water supply tank 12 , a vacuum tank 14 , a sediment tank 16 , a coagulant tank 18 , a muck tank 20 , an ultra-high pressure pump 22 , and a blast head 34 . Clean water is stored in the water tank 12 . Preferably, the water tank 12 has about a 2,700 gallon capacity. The water tank 12 functions not only to store substantially non-contaminated water, but also to provide a constant source of water to the ultra-high pressure water pump 22 . Water drains from the water tank through water port 40 , entering supply line 30 which extends to charge pump 24 . Charge pump 24 forces the water through a mixing tube 26 so that coagulant from the injection pump 28 is thoroughly mixed with the water. The injection pump injects coagulant and/or flocculent into supply line 30 based on the measured amount of coagulant in the water as measured by the coagulant tester 32 . It should be noted that the coagulant may be injected into the system as the water enters the water tank 12 or vacuum tank without departing from the scope of the invention. Fluid exiting the mixing tube is routed through a 5 micron filter 36 and thereafter through a 1 micron filter 38 . The and 5 micron filters are preferably cartridge type filters that allow for easy maintenance. Water exiting the 1 micron filter is routed to the ultra-high pressure pump 22 . The ultra-high pressure pump preferably pumps about 12 gallons of fluid per minute at a pressure of about 40,000 pounds per square inch (PSI). Fluid discharges from the ultra-high pressure pump via high pressure line 46 to the blast head 34 which includes a plurality of nozzles 42 . From the nozzles 42 , the fluid impinges upon a surface entraining particles within the fluid. It should be noted that while the water recirculation system is particularly suited for use with pressure cleaning systems, it could be utilized with many municipal, industrial, and private water cleaning operations without departing from the scope of the invention. Vacuum pump 44 provides a negative pressure to vacuum tank 14 via line 45 . Vacuum line 48 extends between vacuum tank 14 and shroud 41 that extends around blast head 34 . The shroud contains the water as it impinges upon the surface so that the vacuum can draw the solid containing dirty water into the vacuum tank 14 .
Referring to FIGS. 1 , 2 A and 2 B, the vacuum tank is illustrated. The vacuum tank 14 includes an outer wall having sufficient thickness to withstand the vacuum created by vacuum pump 44 which is preferably a roots blower type. Contained within the vacuum tank is a basket constructed from an expanded metal and supported to be spaced away from the outer wall 52 on all sides. A filter bag 56 is hung from the outer wall 52 on hooks 58 so that the top of the bag is open to accept the dirty water flowing into the vacuum tank through vacuum line 48 . The dirty water flows through the filter bag 56 to the area between the basket 54 and the outer wall 52 , leaving a large portion of the entrained solids within the filter bag 56 . As the vacuum tank 14 fills with water, transfer pump 60 moves water from the vacuum tank to the sediment tank 16 via transfer line 62 . Transfer line 62 includes a float assembly 64 at about a distal end thereof. The float assembly maintains the aperture 66 below the upper surface of the dirty water and above the bottom of the tank as it has been found that a layer of debris floats on the upper surface of the water while the larger solids settle to the bottom of the vacuum tank. FIG. 2B illustrates an alternative embodiment of the vacuum tank illustrated in FIG. 2A . In this embodiment, the vacuum tank 14 includes at least one magnet 55 secured to one of the tank walls. In a most preferred embodiment, the magnet 55 is an electro-magnet, secured to the tank so that the magnetic flux created by the magnet contacts the water flowing into the vacuum tank 14 . In this manner, magnetic particles or particles including a magnetic coagulant and/or flocculent are attracted to the magnet thereby removing them from the water. Turning off or scraping the magnet allows these particles to be removed from the tank when the vacuum tank is emptied.
Referring to FIGS. 1 , 3 , 4 and 5 , the sediment tank 16 is illustrated. The sediment tank includes an outer shell 66 . Within the outer shell 66 are one or more, and preferably a pair of horizontal baffles 68 . The horizontal baffles include a plurality of apertures sized to cooperate with a vertical baffle system illustrated herein as sediment tubes 69 . The sediment tubes 69 are preferably about 2 inches in diameter, and in a most preferred embodiment there are about 200 sediment tubes suspended between the horizontal baffles 68 within the sediment tank 16 . The sediment tubes 69 are sized to utilize vibrations from the mobile frame to cause the liquid contained therein to agitate suitably to allow the coagulant to function and bind the suspended solids 67 within the fluid 71 so that they drop to the bottom of the sediment tank faster than the water level rises through the tank. Tubes that are too small don't allow adequate agitation, while tubes that are too large provide too much agitation and prevent settling of the suspended solids. It should be noted that other vertically oriented baffles sized and shaped to utilize vibration to bind suspended solids within a liquid may be utilized without departing from the scope of the invention. It should also be noted that other means of applying free or forced vibration to the sediment tank may be utilized without departing from the scope of the invention. Such vibrations may be random or periodic and may be generated by one or more devices well known on the art. The outer shell 66 and the transfer pump 60 are preferably sized so that the water rises within the tank at about 2 inches per minute. It has been found through experimentation that a coagulant such as aluminum chlorhydrate will bind the suspended solids 77 together and they will fall through the tubes at about 4 inches per minute. In this manner, the fluid, e.g. water, retains less solids as it moves vertically through the sediment tank. Pivotally mounted within the lid 70 of the sediment tank 16 is a continuous filter 72 ( FIG. 4 ). The continuous filter includes a belt 74 of filter material such as, but not limited to, cloth, a pair of rollers 76 , a divider plate 78 and a vacuum head 80 . The belt 74 is sized to extend around the rollers 76 . At least one of the rollers includes a roller motor 82 sized to rotate the roller at about 6 inches per minute. Rollers having internal motors are well known in the art of conveyors and may include frequency generators or stepper motors to control the rotational speed of the roller. Fluid flowing upward through the sediment tank flows through the bottom portion of the filter belt depositing any remaining solids 77 on the surface thereof. The cleaned water is allowed to flow to the fresh water tank 12 for reuse. The divider plate 78 separates the lower (first) and upper (second) portions of the belt so that the upper portion of the belt is subjected to vacuum through the vacuum head to clean the upper portion of the filter belt. The vacuum head is preferably sized to cover the width of the belt. The filter belt is sized and positioned into the water column 71 so as to regulate the head pressure provided by the fluid flowing upward through the sediment tank. In a most preferred embodiment, the filter belt is a 1 micron cloth belt submerged about six inches into the water. This construction allows the user to precisely establish the pressure, per square unit of measure that is applied to the filter belt to force the liquid through the filter. In this manner, lowering the filter raises the head pressure and raising the filter toward the surface of the water lowers the head pressure. At a flow rate of about 12 gallons per minute, about 4,600 square inches of 1 micron filter belt have been found to be sufficient, so that about 5 inches of mercury vacuum are sufficient to clean the filter belt. The filter belt is sized to allow the desirable amount of water to flow therethrough at a head pressure that allows the solid particles 77 to be lifted from the filter belt 74 with vacuum after use. Altering the size of the mesh of the filter belt 74 may require repositioning of the filter belt in the column of water 71 to maintain the desired characteristics. The fluid then exits the sediment tank 16 through aperture 84 and flows through conduit 86 to the water supply tank 12 . As the dirty filter belt travels around the rollers, the vacuum head 80 uses vacuum from the vacuum tank 14 , supplied via conduit 88 , to remove the solid debris from the surface of the filter belt. A muck tank 20 may be provided within the vacuum conduit to aggregate the solid material vacuumed off of the filter belt. The tanks are all preferably provided with openings, hatches, doors or the like suitable to allow cleaning of the system as required. It has been found using this system and method that the coagulated solids are substantially only lightly adhered to the filter belt and are not embedded therein. This allows the vacuum to easily pull the solids off of the filter belt so that it can be used in continuous operation.
It should noted that while aluminum chlorhydrate is the preferred coagulant, other coagulants such as but not limited to aluminum chloride, aluminum sulfate, ferric chloride, ferric sulfate, poly aluminum chloride, clays, sodium aluminate, ULTRA-FLOC, WESTCHLOR, inorganic/polymer blends and suitable combinations thereof, may be utilized without departing from the scope of the invention. It should also be noted that these coagulants may include or be combined to carry iron to create a magnetic flocculent or coagulant.
|
The present invention relates generally to an environmentally sensitive mobile cleaning system, and more specifically relates to a closed loop water recirculation system for high or ultra-high pressure mobile cleaning apparatus. The system includes a water tank sized to contain an established volume of fluid sufficient to circulate through the system, a pump to pressure the fluid to a cleaning head, a vacuum system to return the contaminated fluid to the system, and a filter means to remove the contaminants from the fluid so that clean fluid can be reintroduced to the cleaning head. The method comprises the steps of increasing the pressure of a fixed volume of fluid in a closed-loop system, jetting or blasting the surface with the pressurized fluid, vacuuming the blasted fluid into the system, and removing the contaminants from the fluid.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority of the U.S. Provisional Patent Application 61/769,023 filed on Mar. 4, 2013 entitled “Container with Removable Dividers,” the contents of which are hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to storage containers with lids. More particularly, the present invention relates to storage containers with removable partitions allowing compartmentalization.
Traditional storage containers feature either a non-compartmentalized or compartmentalized interior enclosed by a lid for sealing and securing contents. Users often desire to store consumable and non-consumable goods in containers and are forced to use more than one container in order to avoid mixing contents or creating an undesired combination of certain types of contents as a result of having a non-compartmentalized container. Users may find compartmentalized containers are not always ideal, because the storage proportions in fixed-compartment containers do not match the user's requirements. As such, a container that allows users to reconfigure compartment sizes within the storage container is often useful, as it allows for separation of contents while allowing a level of customization not found in fixed compartment containers.
Prior art teaches containers with removable partitions so users can customize compartment sizes. The problem with the containers found in the prior art that feature removable partitions is the partitions do not provide a liquid-proof seal, leading to unwanted transfers of consumables or non-consumables between partitions.
The inventor performed a prior art search for storage containers of interest. The following U.S. patents of interest are:
U.S. Pat. No.:
Issue Date:
Inventor:
4,360,105
Nov. 23, 1982
Williams
5,547,098
Aug. 20, 1996
Jordan
6,467,647
Oct. 22, 2002
Tucker
D555,475
Nov. 20, 2007
Enriquez
8,322,530
Dec. 4, 2012
Furlong
8,328,034
Dec. 11, 2012
Miros
SUMMARY OF THE INVENTION
A storage container with a lid and an interior comprised of tracks and removable dividers that form a watertight seal between compartments so that contents are not inadvertently mixed. The container may be used for consumables and non-consumables in both solid and liquid states. The removable dividers may be arranged within the tracks to modify the sizes of the individual compartments. The lid of the container fits flush with the sides of the container and the seals on the removable dividers to form a leak-proof container.
The removable dividers are inserted into tracks inside the storage container and allow the user to customize the storage configurations within the container. Rubberized edges surround the exterior dimensions of the removable dividers and provide for a leak-proof seal between compartments. The tracks that hold the removable dividers may be designed in such a way as to apply pressure to the removable dividers to seal and further prevent leakage between compartments. The configuration of the removable dividers and tracks may vary in quantity, dimensions, design and shape.
The inventor believes the present invention is an improvement over prior art because it allows a level of customization not found in the prior art. By utilizing removable dividers with leak-proof seals, the present invention improves on prior art by stopping leakages between compartments in customizable storage containers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present invention showing the removable dividers and their insertion points in the tracks, according to the preferred embodiment of the present invention.
FIG. 2 is a perspective view of the present invention with the removable dividers placed in the tracks according to the preferred embodiment of the present invention.
FIG. 3 is the individual side view of the horizontal removable divider according to the preferred embodiment of the present invention.
FIG. 4 is an individual top view of the horizontal removable divider according to the preferred embodiment of the present invention.
FIG. 5 is an individual side view of the removable center vertical divider according to the preferred embodiment of the present invention.
FIG. 6 is a side view of the container, demonstrating the orientation of the horizontal and vertical dividers, their insertion points within the tracks and the lid of the preferred embodiment of the present invention.
FIG. 7 is an aerial view of an alternative embodiment of the present invention showing the removable dividers and their insertion points in the tracks.
FIG. 8 is an aerial view of an alternative embodiment of the present invention with the removable dividers placed in the tracks.
DETAILED DESCRIPTION OF THE INVENTION
The system and methods described herein are provided for container assemblies for storing and transporting consumable and non-consumable products. The container assembly generally comprises one or more modifiable compartments and a lid for sealing the contents within the container. The container assembly may include two or more tracks for housing removable dividers with rubberized edges. One or more removable dividers may be used to configure storage compartments in the interior of the container assembly.
Referring now to the preferred embodiment of the current invention as shown in FIG. 1 , there is shown the container 10 having removable horizontal divider 17 and removable vertical center divider 21 in disengaged mode. The preferred embodiment of the present invention consists of a container 10 with compartmentalization features. Side track channels 27 meet a bottom horizontal track channel 25 . A bottom center track channel 24 meets the bottom horizontal track channel 25 . A vertical center side track channel 26 meets the bottom center track channel 24 . The track channels 24 25 26 27 provide pressure to the removable horizontal divider 17 and removable center divider 21 when they are placed in the tracks to form a watertight seal between the storage chambers.
Still referring to the preferred embodiment of the present invention as shown in FIG. 1 , the removable horizontal divider 17 features rubberized side edges 18 , a rubberized bottom edge 19 and a vertical track 20 , which is configured to join flush with the bottom center track channel 24 . The removable horizontal divider 17 slides within the container's vertical center side track channel 26 and horizontal track channel 25 when so desired by the user. The removable center divider 21 features rubberized side edges 22 and a rubberized bottom edge 23 . The removable center divider 21 slides within the container's vertical center side track channel 26 and the vertical track 20 of the removable horizontal divider 17 when further separation of compartments is desired.
Still referring to FIG. 1 , the preferred order of compartmentalization is to engage the horizontal removable divider 17 prior to engaging the removable center divider 21 . FIG. 1 illustrates the fitting orientation of the horizontal removable divider 17 , wherein rubberized edges 18 19 slide into the horizontal track channels 25 27 . FIG. 1 . Illustrates the fitting orientation of the center vertical removable divider 21 , wherein the rubberized edges 22 slide into the vertical center side track channel 26 and the rubberized edge 23 slides into the bottom center track channel 24 .
In the preferred embodiment of the present invention, the container 10 , and all tracks 24 25 26 27 are formed from a single piece of molded plastic. The preferred embodiment of the present invention calls for the horizontal removable divider 17 and center removable divider 21 to be formed of molded plastic as well, with the edges 18 19 22 23 formed from silicone, which is bonded to the dividers 17 21 . Alternative embodiments of the present invention allow for construction of different materials, such as glass, Pyrex or metal, and utilizing differing forming techniques.
FIG. 2 shows how the different components of the container 10 and removable dividers 17 21 work together to provide sealed compartments when the removable dividers 17 21 are coupled into the tracks 24 25 26 27 . FIG. 2 shows the center vertical removable divider 21 perpendicular to the horizontal removable divider 17 , and between the vertical side track channel 26 and the vertical track 20 of the horizontal removable divider 17 .
FIG. 3 shows the horizontal removable divider 17 apart from the preferred embodiment of the present invention. Seen in FIG. 3 are the horizontal removable divider 17 , rubberized edges 18 19 and vertical track 20 .
FIG. 4 shows an alternative view of the horizontal removal divider 17 apart from the preferred embodiment of the present invention and from above and demonstrates the rubberized edges 18 and vertical track 20 .
FIG. 5 shows the removable center vertical divider 21 with rubberized edges 22 and 23 .
FIG. 6 is a side view of the container assembly 10 , showing the rubberized edges 18 19 and vertical track 20 of the horizontal removable divider 17 . FIG. 6 shows the position of the rubberized edges 18 19 of the horizontal removable divider 17 , in relation to the tracks of the container 25 27 . The lid 30 snaps securely in place onto the lip 11 of the container 10 . FIG. 6 shows the position of the rubberized edges 22 23 of the removable center vertical divider 21 as they fit within the container 10 .
FIG. 6 depicts the orientation of one end of the horizontal removable divider 17 into the side track channel 27 and the orientation of the fitting of the perpendicular, vertical center removable divider 21 wherein the edges 22 fit respectively into the vertical center track channel 26 and into the center track 20 of the horizontal removable divider 17 . FIG. 6 further depicts lid 30 and its orientation with the lip 11 of the container 10 .
FIG. 7 is an aerial view of an alternative embodiment of the present invention. FIG. 7 shows a circular container 10 , horizontal wall channel 27 , horizontal bottom channel 25 , bottom center channel 24 and a vertical center wall channel 26 . FIG. 7 also shows, in removed position, a removable divider 17 having rubberized edges 18 , and a center track 20 . FIG. 7 also shows, in removed position, a center vertical removable divider 21 having rubberized edges 22 . FIG. 7 illustrates the orientation of engagement of the components of this embodiment.
FIG. 8 is an aerial view of the container according to the alternative embodiment of the present invention from FIG. 7 . FIG. 8 shows horizontal wall channels 27 , a horizontal bottom channel 25 , a vertical bottom channel 26 , and the center bottom channel 24 . The horizontal removable divider 17 with a center track 20 and corresponding rubberized edges 18 is shown inserted within the channels 24 25 26 27 .
While particular embodiments have been shown and described, the above variations are for illustrative purposes. It will be apparent to those skilled in this art that a plurality of equivalent variations, changes, combinations to the idea of and without departing from the disclosing and explanation of this invention and its broader aspects shall also fall within the technical scope of the appended claims and encompass all such changes within the true spirit and scope of this invention. Therefore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those skilled in this art that, in general, terms used herein, particularly appended claims (e.g. bodies of the appended claims) are generally intended as “open” terms (e.g. the term “including” is to be interpreted as “including but not limited to”, the term “comprising” is not to be interpreted as limiting, the term ‘having” is not to be interpreted as “having only”.
Any elements described herein as singular can be pluralized, and plural elements can be used in the singular. The above-described elements, assemblies and methods, elements for carrying out the invention, and variations of aspects of the invention can be modified such as dimensions, volumes, shapes, sizes, method of manufacturing, in a plurality of different ways and type of utility.
|
A storage system is provided comprising a container, lid and removable dividers with rubberized edges. The container features at least one track into which corresponding removable dividers with rubberized edges are inserted and held in place. The removable dividers of the system are inserted into the track(s) of the container and form a watertight seals and separate the container into two or more sections. The lid of the system is secured to the container with a threaded or pressure snap attachment mechanism and forms a watertight seal.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image device and related electronic device, and more particularly to a composite image device combined with digital photographing, laser pointing and bar-code scan and related portable electronic device.
2. Description of the Prior Art
Nowadays, consumption electronic products gradually evolve into “All in one” feature. Therefore, for portable electronic product development, manufactures attempts to integrate various daily demands into one model. Consumers can choose a composite electronic product to decrease inconvenience caused by too many products in hand. So far, the products which consumers have used the most in daily lives are digital cameras, laser pointers and quick response (QR) code scanners.
In general, a mobile phone is provided with functionality of wireless communication, simple image capturing and music listening. A higher level multi-function camera-mobile phone even has a flash. In the camera mode, the mobile phone with a QR code scan function displays a scanning area calibration pattern on the monitor. A user calibrates a QR code on captured image within coverage of the scanning area calibration pattern for decoding. Please refer to FIG. 8 , which is a schematic diagram of a QR code scanning area calibration pattern 80 generated from a mobile phone 900 according to the prior art. In FIG. 8 , when the mobile phone 900 enters the camera mode, a monitor 910 displays a captured image and a scanning area calibration pattern 90 . The user must restrict a QR code image 920 of the captured image within the scanning area calibration pattern 90 . However, the use can have problem with calibration if the captured image is unclear or the resolution is low.
SUMMARY OF THE INVENTION
It is therefore an objective of the present invention to provide a composite image device and related portable electronic device for providing functions of image capturing, laser pointing and bar code scanning and generating an aimed pattern on a desired bar code in order to increase convenience of bar code scanning.
The present invention discloses a composite image device including a first perspective window, a second perspective window, a third perspective window, an image capturing module, laser source module, a light source module and a switchable light modulating module. The image capturing module includes a light-sensing device for capturing ambient light through the first perspective window to generate digital image data. The laser source module emits a laser through the second perspective window. The light source module emits illuminating light through the third perspective window. The switchable light modulating module includes at least a light modulating gate and a switching device for moving the at least a light modulating gate to a position relatively parallel to the second or third perspective window to modulate the emitted laser or the emitted illuminating light.
The present invention further discloses a portable electronic device. The portable electronic device includes a housing, a display panel, a digital signal processor, a connecting device and a composite image device. The digital signal processor is coupled to the display panel and used for processing a digital image data and outputting the processed digital image data to the display panel and generating a first controlling signal, a second controlling signal and a third controlling signal. The composite device is coupled to the connecting device and includes a first perspective window, a second perspective window, a third perspective window, an image capturing module, laser source module, a light source module and a switchable light modulating module. The image capturing module includes a light-sensing device for capturing ambient light through the first perspective window to generate digital image data. The laser source module emits a laser through the second perspective window. The light source module emits illuminating light through the third perspective window. The switchable light modulating module includes at least a light modulating gate and a switching device for moving the at least a light modulating gate to a position relatively parallel to the second or third perspective window to modulate the emitted laser or the emitted illuminating light.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a composite image device according the first embodiment of the present invention.
FIG. 2 is an external view of a composite image device according to FIG. 1 .
FIG. 3 is a schematic diagram of a bar code scanning area calibration pattern according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of a switchable light modulating module according to an embodiment of the present invention.
FIG. 5 is an external view of a composite image device according to the second embodiment of the present invention.
FIG. 6 is an external view of a mobile phone according to an embodiment of the present invention.
FIG. 7 is a block diagram of the mobile phone in FIG. 6 .
FIG. 8 is a schematic diagram of a bar code scanning area calibration pattern according to the prior art.
FIG. 9 is a schematic diagram of a bar code scanning area calibration pattern according to an embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram of internal structure of a composite image device 10 according to an embodiment of the present invention. FIG. 2 is an external view of the composite image device 10 . The composite image device 10 has image capturing, bar code scan, laser pointing, lighting and related functions and includes a housing 100 , a first perspective window 110 , a second perspective window 120 , a third perspective window 130 , an image capturing module 140 , laser source module 150 , a light source module 160 and a switchable light modulating module 170 . The lenses 112 , 122 and 132 are mounted on the first perspective window 110 , the second perspective window 120 , and the third perspective window 130 . The image capturing module 140 includes a light-sensing device 142 and an optical lens set 144 and is used for capturing ambient light through the first perspective window 110 . The light-sensing device 142 could be a Charge Couple Device (CCD) or Complementary Metal-Oxide Semiconductor (CMOS) light-sensing device. The optical lens set 144 could be a variable focus or fixed focus lens set. Besides, the image capturing module 140 includes signal processing components, such as amplifiers, analog to digital converters (ADCs) and image sensors, for processing the ambient light captured by the light-sensing device 142 and thereby generating an digital image data. The laser source module 150 includes a red laser diode 152 and is used for emitting a laser through the second perspective window 120 . The light source module 160 includes a white laser diode matrix 162 and is used for emitting illuminating light through the third perspective window 130 . The switchable light modulating module 170 includes a light modulating gate 172 and a switching device 174 . As known in FIG. 2 , the housing 100 has a rectangular gap 102 and the switching device 174 is bulged out of the housing 100 . Consequently, by adjusting the position of the switching device 174 , the user can move the light modulating gate 172 to a position relatively parallel to the second perspective window 120 or the third perspective window 130 . The light modulating gate 172 is a diffraction gate including a diffraction lens which generates a scanning area calibration pattern and has diffraction effect only upon laser. When the light modulating gate 172 is located between the second perspective window 120 and the laser source module 150 , the point light source is diffracted to a scanning area calibration pattern 30 as shown in FIG. 3 after passing through the light modulating gate 172 .
When the composite image device 10 works for capturing image, the image capturing module 140 is used for capturing image, the light source module 160 is used as a flash, and the laser source module 150 is suspended.
When the composite image device 10 works for scanning a bar code with one or two dimension, the laser source module 150 projects the scanning area calibration pattern 30 through the light modulating gate 172 for calibration of bar code reception area. The image capturing module 140 is used for capturing a bar code image. The light source module 160 can be an illuminating light in the dim surroundings for enhancement of brightness and clearness.
When the composite image device 10 is used as a laser pointer, the light modulating gate 172 needs to be moved to a position relatively parallel to the third perspective window 130 in order to allow the laser emission to pass throughout the second perspective window 120 without diffraction.
As known above, the user can use functions such as image capturing, code scanning, laser pointing and illuminating by use of the composition device 10 .
Please note that, the laser source module 150 can emit green laser or others, and red laser is preferable. The light source module 160 can emit green light and others, and white light is preferable. Besides, the scanning area calibration pattern 30 is just an exemplary embodiment of the present invention. Those skilled in the art can design appropriate patterns based on different bar code types.
Especially, according to an embodiment of the present invention, those skilled in the art can adjust functions or the number of the switchable light modulating module 170 according to product requirements and accordingly modify the shape or position of the related devices. For example, please refer to FIG. 4 , which is a schematic diagram of a switchable light modulating module 470 according to an embodiment of the present invention. The switchable light modulating module 470 includes light modulating gates 472 , 476 , and a switching device 474 . The light modulating gate 472 and the switching device 474 are identical to the light modulating gate 172 and the switching device 1474 in FIG. 1 respectively. The light modulating gate 476 is a light filtering gate and includes a filtering lens. Please refer to FIG. 5 , which is an external view of a composite image device 50 using the switchable light modulating module 470 according to an embodiment of the present invention. The external and internal structures of the composite image device 50 are similar to those of the composite image device 10 . Compared with FIG. 1 , a rectangular gap 502 in FIG. 5 is obtained by adjusting the size and position of that rectangular gap 102 in FIG. 1 . The distance between the first perspective window 110 and the second perspective window 120 is increased from L to L 1 . Correspondingly, the distance between the image capturing module 140 and the laser source module 150 is increased. Thus, by shifting the switching device 474 , the users can move the light modulating gate 476 to the position corresponding to the first perspective window 110 for light filtering or move the light modulating gate 472 to the position corresponding to the second perspective window 120 for diffraction pattern generation.
Preferably, the composite image device 10 is applied to portable electronic device such as a mobile phone, a laptop or a digital camera. In the case of the mobile phone, please refer to FIG. 6 , which is an external view of the mobile phone 60 according to an embodiment of the present invention. The mobile phone 60 includes a housing 600 , a display panel 610 , a connecting device 620 and a composite image device 630 . As can be seen in FIG. 6 , the housing 600 has a cylindrical notch 602 . The connecting device 620 has a cylindrical body housing that is able to be embedded into the cylindrical notch 602 for rotating the composition image device 630 . In addiction, the connecting device 620 transmits the controlling signals and digital image data between the composite image device 630 and the main part of the mobile phone 60 . The composite image device 630 could be the composite image device 10 in FIG. 1 , the composite image device 50 in FIG. 5 or any other composite device that is properly modified by those skilled in the art. The detailed structure and functions has been described above, and thus are not narrated herein. Consequently, the user can adjust a light emitting angle for code scanning, laser pointing and illuminating by rotation of the composite image device 630 rotated by the connecting device 620 .
Note that, the connecting device 620 of the mobile phone 60 is just an embodiment of the present invention. Besides rotating the composite image device, the connecting device 620 is used for mounting the composite image device 630 on the housing 600 . Those skilled in the art can modify the structure and shape of the connecting device 620 .
Please refer to FIG. 7 , which is a block diagram of the mobile phone 60 according to an embodiment of the present invention. The mobile phone 60 includes a core processor system 700 , an image capturing module 710 , a laser source module 720 and a light source module 730 . The core processor system 700 includes a panel controller 702 , memory 704 and a digital signal processor 706 . The digital signal processor 706 is used for processing digital image data DID generated by the image capturing module 710 and thereby outputting a display data DSD to the display panel 610 through the panel controller 702 . The memory 704 is used for storing processed or unprocessed digital image data DID. Moreover, the digital signal processor 706 generates a first controlling signal SC 1 , a second controlling signal SC 2 and a third controlling signal SC 3 which are all transmitted to the composite image device 630 via the connecting device 620 in FIG. 6 for controlling the image capturing module 710 , the laser source module 720 and the light source module 730 through respectively. The image capturing module 710 includes a lens subsystem 800 and a sensor subsystem 810 . The lens subsystem 800 includes an optical lens set 802 and a focus adjusting device 804 . The sensor subsystem 810 includes a light-sensing device matrix 812 , an amplifier 814 , an analog to digital converter (ADC) 816 , an image processor 818 and a controlling interface 820 . The first controlling signal SC 1 is used for opening or closing the image capturing module 710 or instructing the controlling interface 820 to perform related image capturing mode. The controlling interface 820 generates corresponding parameters to control the optical lens set 802 , the light-sensing device matrix 812 , the amplifier 814 , the ADC 816 and the image processor 818 . The amplifier 814 and the ADC 816 are responsible for adjusting and converting light sensing signals outputted from the light sensing device matrix 812 . The image processor 818 generates digital image data DID for the digital signal processor 706 . The laser source module 720 includes a laser diode driver unit 722 and a laser diode matrix 724 . The light source 730 includes a light emitting diode (LED) driver unit 732 and an LED matrix 734 . The laser diode driver unit 722 and LED driver unit 732 drive the laser diode matrix 724 and the LED matrix 734 according to the second controlling signal SC 2 and the third controlling signal SC 3 , respectively.
Please refer to FIG. 9 , which is a schematic diagram of a scanning area calibration pattern 1000 according to an embodiment of the present invention. FIG. 9 illustrates a laser source module 1100 projecting a scanning area calibration pattern 1000 on a bar code 1300 through a diffraction lens 1210 of a diffraction gate 1200 . The scanning area calibration pattern 1000 is identical to the scanning area calibration pattern 30 in FIG. 3 . The laser source module 1100 and diffraction gate 1200 can be realized by the laser source module 150 and the light modulating gate 172 in FIG. 1 and thus not narrated herein.
In conclusion, the embodiments of the present invention provide a image device with image capturing, code scanning, laser pointing and illuminating functions in one and related portable electronic product for meeting users' requirement. In addiction, in the code scanning function, the scanning area calibration pattern is directly projected on the target code to eliminate the use of screen image during capturing calibration of the bar code.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
|
A composite image device having image capturing, laser pointing, lighting and related functions in one includes a first perspective window, a second perspective window, a third perspective window, an image capturing module, laser source module, a light source module and a switchable light modulating module. The image capturing module captures ambient light through the first perspective window to generate digital image data. The laser source module emits a laser through the second perspective window. The light source module emits illuminating light through the third perspective window. The switchable light modulating module includes at least a light modulating gate and a switching device for moving the at least a light modulating gate to a position relatively parallel to the second or third perspective window to modulate the emitted laser or the emitted illuminating light.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reinforced plastic composite structure. More particularly, the present invention relates to a corrosion resistant plastic composite structure, such as pipe, which is not prone to failure when exposed to corrosive liquids, e.g. acid.
2. Description of Prior Art
Reinforced plastic composite structures, for example pipes, are commonly formed by winding resin-impregnated filaments on a removable mandrel, curing the resin-impregnated structure and subsequently removing the mandrel from the cured pipe. By appropriate selection of the filaments and the resin (typically glass filaments and a polyester resin), the composite pipe can be fabricated so as to exhibit generally acceptable corrosion resistance in applications not exposed to stress conditions. Such corrosion resistance is due to the inherent resistance of polyester resin to acid and alkali attack. However, when the pipe is subjected to heavy external loading, for example, by the weight of backfill placed over it when the pipe section is buried in the ground, crazing of the interior surface of the resin, often a gel coat, can occur, thereby exposing the filaments to acidic conditions.
More specifically, when a pipe section is subjected to such external loading, deformation of the pipe section is resisted by shear stresses which tend to concentrate along the inner-circumferential wall surface of the pipe. These shear stresses, in turn, can result in the resin crazing or cracking along this inner-circumferential surface. If excessive strain causes the resin to crack or craze, the glass filaments may be exposed to corrosive attack. When corrosive fluid, such as acid, attacks the glass filaments, penetration of the entire pipe wall structure by the acid can occur very rapidly and can result in mechanical failure of the entire composite structure. This cracking problem and resultant mechanical failure is particularly likely when the composite structure is used as sewer pipe. Bacteria and other microorganisms attack organic materials in domestic sewage to form acids capable of attacking the glass reinforcement filaments. Since the glass filaments provide strength to the composite structure, if these are weakened by corrosive attack, the entire pipe can fail.
Various attempts have been made in the past to overcome the potential failure problem of reinforced plastic pipe due to corrosive attack of the wall structure. Most of these attempts have concentrated on various improvements of a craze resistant interior surface gel coat lining to protect the glass fibers from acid attack. One known craze resistant gel coat is disclosed in U.S. Pat.No. 3,893,488. The present invention does not require a special inner lining or gel coat, but rather provides a reinforced plastic structure which throughout its entire thickness is designed to resist crazing under normal external stress conditions. Even if some cracking or crazing of the resin matrix results due to external stress on the structure, the resin matrix of the present invention has been found to inhibit propagation of such cracks. Since any cracks which do result do not increase in size or number by further exposure to acidic fluids, the glass filaments are not exposed to acid attack and retain their reinforcement ability.
Heretofore, the resin matrix in reinforced plastic pipe composites generally has been filled with a relatively inexpensive inert filler such as aluminum silicate clay. For example, U.S. Pat. No. 3,706,615 discloses the incorporation of additives such as sand, calcium carbonate generally, or clay in the resin and U.S. Pat. No. 3,406,724 discloses the incorporation of 20-85% of a filler such as quartz, chalk, kaolin, or rock flour in plastic sewer pipe. As will be seen hereinafter, the present invention is not intended to cover the incorporation of calcium carbonate generally as a filler. Rather, the present invention is directed to incorporating into the resin component a particulate substance having a specific particle size and selected from the group consisting of portland cement, marble dust or a mixture thereof. These substances are not merely inert fillers, but rather, their incorporation in the resin produces a structure exhibiting much greater acid resistance than prior art composite structures.
BRIEF DESCRIPTION OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide an improved reinforced plastic composite structure, specifically a pipe, which reduces the crazing or cracking tendency throughout the wall of the pipe.
Another object of the present invention is to eliminate the need for an interior gel coat layer in a reinforced plastic composite structure.
A further object of the present invention is to provide a method of making this composite structure.
The reinforced plastic composite structure includes at least one layer of fibers encased in a cured acid-resistant polymeric resin matrix. In accordance with the present invention, the improvement comprises incorporating a particulate substance selected from the group consisting of portland cement, marble dust or a mixture thereof in the polymeric resin matrix prior to curing thereof. Individual particles having an equivalent spherical diameter within the range of 10 to 70 microns comprise at least about 80% of the particulate substance or mixture incorporated into the resin matrix. Preferably about 65% of the particulate substance has an equivalent spherical diameter within the range of 10 to 40 microns. Since the particulate substance typically has an irregular configuration its size is represented by the diameter of a sphere having the same mass and specific gravity as the particle being measured. The comparative determination of the particle size can be achieved by any suitable means, e.g. a particle size analyzer such as a Coulter Counter manufactured by Coulter Counter Electronics, Inc., Hialeah, Fla.
When the composite structure of the present invention is a tubular article, e.g. a pipe, the method of making this pipe typically includes wrapping a fibrous sheet (or a layer of continuous filaments) saturated with an uncured polymeric resin matrix around a removable mandrel. Additional layers, for example, of continuous glass filaments or fiber glass tapes are subsequently wrapped around the mandrel. All of the layers are encased in the acid resistant polymeric resin matrix of the present invention. The resin matrix is subsequently cured so as to bond the layers together in a laminar relationship and the mandrel is removed.
The present invention provides a reinforced plastic composite structure which exhibits outstanding resistance to both acids and bases under typical external loading stress conditions. Propagation of cracks through the wall structure is inhibited, thereby providing a product having improved structural integrity.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention provides a reinforced plastic composite structure including an inner fibrous sheet, e.g. a veil cloth. A variety of fibers are suitable for use in the inner sheet including glass, polyester, polypropylene and polyamide fibers. In a preferred embodiment of the present invention, the inner sheet is a spunbonded veil cloth of crimped polyester fibers marketed by E. I. du Pont de Nemour and Co., Inc., under the trademark REEMAY. Such a spunbonded sheet exhibits good resistance to longterm exposure to both acids and alkalies in the range of 0.1 to 10.0 pH at temperatures below 100° F. and it exhibits a high break elongation.
The inner sheet is positioned around a forming surface, e.g. a mandrel, after saturation with an uncured polymeric resin matrix produced in accordance with the present invention.
The polymeric resin matrix of the present invention is formed from typical polymeric binder systems used in the preparation of reinforced plastic structures. The particular resin binder system utilized should be selected so as to enhance chemical bonding between the fibrous layers and the resin as the resin cures. Various promoters and catalysts may be incorporated in the resin matrix to accelerate or promote curing of the resin. For example, in an actual working embodiment, a polyester veil cloth is saturated with an isophthalic polyester resin to which a peroxide base catalyst and a diethyl-aniline promoter have been added.
In some instances it may be desirable to add flexibilizers to the resin. The incorporation of flexibilizers at levels of up to 15% by weight of the resin solids improves the elongation properties of the resin, and thereby tends to minimize the stress-cracking tendency of the resin. The selection of a particular flexibilizer will generally be in accordance with the recommendation of the manufacturer for a given resin.
The improvement according to the present invention comprises adding particulate marble dust or portland cement or a mixture thereof to a polyester or other suitable resin when the latter is in an uncured state. The actual amount of the particulate substance in the resin will be approximately 40-60 weight percent of the total resin matrix. The actual weight percent of particulate substance may vary depending on a number of known variables including for example the resin used and temperature of the resin. Generally speaking, however, the amount of particulate added should be sufficient to prevent "bleeding" or run off of the resin when saturating the fibers. The upper limit of the amount of particulate substance incorporated in the resin is reached when the resin is thickened to the point where it is unable to penetrate between the fibers during formation of the composite.
At least about 80% of the marble dust particles, portland cement particles, or mixtures thereof incorporated and dispersed throughout the uncured resin matrix have an equivalent spherical diameter within the range of about 10 to 70 microns. Preferably, approximately 65% of the particulate substance or substances incorporated into the uncured resin have an equivalent spherical diameter within the range of 10 to 40 microns.
The viscosity of the resin matrix having the particulate substance incorporated therein is generally within the range of 100-2000 centipoise, preferably within the range of 200-300 centipoise.
When portland cement is incorporated into the resin, it may be in the form of an unhydrated portland cement, a ground reacted (hydrated) portland cement or a mixture thereof. Furthermore, any of the five common types of portland cement can be utilized. In one actual working embodiment, Type 1 portland cement is incorporated into an isophthalic polyester resin. The term marble dust as used herein means particulate calcaceous rock capable of taking a polish, that is, dust from a metamorphic rock resulting from the recrystallization of limestone. The marble particles may be pure or they may have some impurities such as carbonaceous matter or iron oxides provided that any impurities are not of a nature or in an amount sufficient to interfere with the bonding or curing properties of the resin. Examples of suitable marble types which can be used in the present invention include Etowah, Creole, and Rutland marble. In an actual working embodiment Georga Marble Dust #7 marble particles, a Trademark of Georga Marble Co., Atlanta, Ga., were incorporated into a polyester resin.
The resin matrix, including the marble dust and/or portland cement particles, can be used to bond the inner layer to additional layers which typically include a plurality of layers of, for example, continuous glass filaments and glass tape. Sand or other granular material can be dispersed between these layers to increase the wall thickness of the structure.
In an actual working embodiment, a reinforced plastic composite structure of the present invention is formed directly on a conventional rotating mandrel commonly used in fabricating reinforced plastic pipes. A fibrous inner sheet is saturated with the uncured improved resin matrix according to the present invention using a conventional technique. The saturated sheet is then wrapped around the mandrel. Subsequently, the remainder of the wall structure is formed on the mandrel by a plurality of layers of the improved resin, glass filaments, glass woven roving tape and granular material such as sand. A resin-bonded outer layer of coarse granular material, e.g. sand, typically forms the exterior wall surface of the composite structure. The improved resin matrix is subsequently cured and the mandrel is removed from the composite structure.
The following examples are merely illustrative of the present invention and should not be understood as limiting the scope or principles of the invention.
EXAMPLES
A series of tests were made to determine the effect on sewer pipes as a result of exposure to sulfuric acid while under strain. The interior wall surface of arch samples made from 15 inch diameter pipe, (12 in. circumference, 0.3 in. wall thickness and approximately 3 in. wide), were exposed to 5% sulfuric acid while subjected to 11/2% load producing strain. The cut edges were blocked with a room temperature vulcanized rubber in order to form a vessel within the arch to hold the sulfuric acid.
Strength properties of the various test specimens were measured using an Instron testing machine, model number 1102, Instron Corporation, Canton, Mass., set at 0.2 inches per minute ram travel speed and at 2 inches per minute chart speed over a 4 inch span. The testing procedure outlined in the Instron test manual 10-1015-3 for testing load and deflection properties was followed. All of the test sample formulas were identical except for the particulate material incorporated into the resin. Six hundred grams of an isophthalic polyester self-curing resin were mixed with 7 grams of a benzoyl peroxide paste and 18 drops of a diethylaniline promoter. Glass hoops of Owens-Corning roving, standard "E" glass, K861-AA-675 and glass tapes manufactured by Ferro Corporation, "E" glass, style #502 were wrapped about a saturated fibrous layer of REEMAY brand veil cloth #201. The particulate substances tested were:
1. ASP 400 P (Pulverized aluminum silicate clay)-Engelhard Minerals and Chemical Corp.
2. Type 1 Portland Cement (at least 80% having an equivalent spherical diameter within the range of 10 to 70 microns)
3. Marble dust #7-Georga Marble Company (at least 80% having an equivalent spherical diameter within the range of 10 to 70 microns)
4. Whitcarb W-Whitcarb Chemical Company (precipitated chalk)
5. Gamasperse 6532-Georga Marble Company (highly pulverized calcium carbonate)
6. Plaster of Paris (CaSO 4 .1/2 H 2 O) commercial grade.
Equivalent spherical diameters for samples of the particulate substances of the types 1-5 listed above are indicated in Table I.
The test pipe samples were made by winding the resin saturated spunbonded polyester cloth on a conventional mandrel. A pipe build-up operation was performed wherein layers of resin and glass fiber and sand were applied to the rotating mandrel. More specifically, the pipe samples comprised an inner layer of REEMAY cloth, wrapped with successive resin impregnated layers comprising: (1) a layer of glass fiber hoops, (2) a layer of glass fiber tape, (3) a layer of glass fiber hoops, (4) a layer of sand, (5) a layer of glass fiber hoops, (6) a layer of sand, (7) a layer of glass fiber hoops, (8) a layer of sand, (9) two layers of glass fiber hoops, (10) a layer of glass fiber tape, and (11) two layers of glass fiber hoops. A final outer layer of coarse sand was used on all arch samples. Flat plate samples (51/2 in. in length by 3 in. thick, by 0.5 in. wide) were used for water boil testing. The flat plate samples were indentical in construction except for the outer layer. Instead of sand in the flat plate samples, an outer layer of REEMAY veil cloth was used to achieve a smooth flat uniformity on the outer surface of the sample. All samples were allowed to partially cure at room temperature (2-3 hours) before final oven curing of 30 minutes at 175° F.
The amount of particulate material incorporated in the polyester resin was based on resin viscosity (estimated to be between 200-500 centipoise). The portland cement and marble dust #7 which have surface areas of 3500-3800 cm 2 /gm were used at the 300 gram level. The remaining particulate materials tested had surface areas of 5000-6000 cm 2 /gm and were used at the 252 gram level.
Boiling tests were run in tap water over the time period indicated in Table II and the values reported are 5 specimen averages.
The results of these strain tests under corrosive conditions show that plastic pipe having particulate substances selected from the group consisting of portland cement or marble dust incorporated into the resin matrix provide outstanding service life.
As indicated in Table II, the samples with the Georga marble dust #7 had the highest initial flex modulus of rupture (MR) and they maintained about 70% of their initial strength after 3 days in boiling water. It should be noted that the Georgia Marble Dust #7 initial flex MR value is more than 60% greater than the sample using a conventional filler, i.e. ASP 400 P.
None of the samples containing Georga marble dust #7 or portland cement, i.e. samples 2, 3, 7 and 8, failed under the acid strain test during the 30 day test period. Samples 1, 4, 5, 6 and 9 did fail and upon failure the samples cracked and the acid penetrated through the entire wall structure.
TABLE I__________________________________________________________________________Equivalent Spherical Type I Portland Cement Marble Dust #7 Gamasperse 6532 Whitcarb W (ppt ASP 400 pDiameter of Particles % Fraction by % Fraction by % Fraction by % fraction by % Fraction byMeasured in Microns Coutler Counter* Coulter Counter Sedigraph** Coulter Counter Coulter__________________________________________________________________________ Counterless than 1.5 6 less than 1 less 1han 1.0 9 4 less 1han 2.0 less than 1 16 30 1 3.0 less than 1 1 16 30 8 4.0 less than 1 2 12 16 13 5.0 less than 1 2 10 9 12 6.0 less than 1 2 8 6 6 7.0 less than 1 2 4 1 8 8.0 less than 1 2 7 1 7 9.0 less than 1 2 7 1 5 10.0 15 3 4 *** 1 7 15.0 15 13 less than 1 16 20.0 13 15 10 25.0 10 5 4 30.0 7 16 less than 1 35.0 8 11 40.0 4 5 45.0 3 6 50.0 5 3 60.0 2 5 70.0 less than 1 2 80.0 less than 1 less than 1 90.0 less than 1 less than 1 100.0 less than 1 less than 1__________________________________________________________________________ *Coulter Counter - particle size analyzer manufactured by Coulter Counter Electronics, Inc., Hialeah, Florida **Sedigraph - particle size analyzer manufactured by Micromeritic Instrument Corp., Norcross, Georgia ***On random sampls up to 5% +625 mesh (20 microns) agglomerates were noted
TABLE II__________________________________________________________________________ FLAT PLATE SAMPLES 15" ARCH SAMPLES Flex MR (psi)SAMPLE DESCRIPTION Acid Failure Original 3 DAY Boil 7 Day Boil__________________________________________________________________________ ASP 400 P less than 2 days 4360 2850 3050 Portland Cement (Type 1) *greater than 30 days 4375 2670 2710 Marble Dust #7 greater than 30 days 6790 4790 4070 Whitcarb W (ppt Chalk) 13 days Gamaspers (finely pulverized CaCO.sub.3) 9 days Plaster of Paris (CaSO.sub.4) less than 3 days Portland Cement + 100 ppm L-77** greater than 30 days 4800 2400 2230 Marble Dust #7 + 100 ppm L-77 greater than 30 days 5960 4450 3120 90% Gamasperse +10% Type 1 Portland Cement 14 days__________________________________________________________________________ *30 days - arbitrary cut-off time period **L-77 - an organo-silicone surface active agent for polyester systems (Union Carbide)
|
A reinforced plastic composite structure, particularly a pipe, is disclosed herein. The composite pipe, which resists acid attack even in underground applications where the pipe is subjected to external loading stresses, typically includes at least an inner zone, e.g. a resin impregnated fibrous sheet and an outer zone including a layer or layers of fibers. A cured polymeric resin matrix bonds the fibrous sheet and the fibrous layers together in a laminar relationship. The improvement disclosed herein comprises incorporating into this polymeric resin matrix a particulate substance which has specific particle size limitations and which is selected from the group consisting of portland cement, marble dust or a mixture thereof.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an elongate metal body, for instance an aluminium rod with a chosen cross-sectional form manufactured by extrusion.
2. Background Information
Such a body is known in many applications. A well-known application is a skate frame for an ice-skate or roller-skate. Such a frame comprises for instance an elongate carrier manufactured from aluminium by means of extrusion, to which the runner or wheels are connected.
SUMMARY OF THE INVENTION
It is a first object of the invention to make an elongate metal body stiffer and stronger without this entailing an increase in weight. In respect of this objective the metal body according to the invention has the feature that the body has at least one cavity extending at least to a considerable degree in longitudinal direction, in which cavity is received a pre-manufactured elongate reinforcing rod, of which at least the ends are coupled to the body in force-transmitting manner.
The embodiment is recommended in which the rod consists substantially of a bundle of longitudinally extending, continuous fibres embedded in a plastic matrix, in particular consisting of carbon, aramid, glass, boron, reinforced polyethylene and other synthetic and ceramic materials. Such a rod of composite material combines a very great longitudinal strength with a low weight.
A very simple and inexpensive embodiment is that in which the rod is connected to the body by glue.
For strengthening and reinforcement this variant can have the special feature that the rod is connected substantially along its whole outer surface to the body.
A further variant is characterized by biasing means for holding the rod under longitudinal bias.
For particular applications this variant can have the special feature that the biasing means are adjustable.
A specific embodiment hereof has the feature that the biasing means comprise screw means.
The biasing means can be embodied such that the rod fits into the cavity with small clearance and the biasing means are adapted to exert a pressure force on the ends of the rod.
An embodiment with optionally adjustable biasing means can have the special feature that the cavity is positioned at a distance from the neutral fibre of the body. The metal body comes under strain of bending due to the longitudinal force exerted at a distance from the neutral fibre. A bending can thus be obtained which, in the case of adjustable biasing means, can be adjusted to a desired value.
This latter embodiment in particular can, as will be described hereinbelow, be important for application in the skating sport. This is the case however for the invention in general. The invention therefore also pertains to a skate frame for an ice-skate or roller-skate which is provided with an elongate metal body having connected thereto an elongate reinforcing rod as specified above.
A runner for an ice-skate is generally ground with a determined radius of curvature. This radius of curvature is arranged in the height direction of the skate.
In the case of short-track skating and 500 metre sprint skating on the track it is at the moment usual for the skates also to have a certain curvature in sideways direction. The value thereof, which can be expressed in the radius of curvature, is greatly dependent on personal wishes and preferences. At the moment the skate frame is herein usually clamped in a vice, wherein a part of the skate is bent manually. The object of this bending operation is to obtain a better grip on the ice in the bend, whereby the skater can negotiate the bend at an even greater angle and speed without the risk of slipping.
As has been stated, the value of the radius of curvature to be adjusted is very person-dependent. The degree of bending must moreover be adapted to the ice conditions, so that there is a need for an adjustable bending.
For the purpose of grinding the runner it is further desirable that the skate is straight or can be straightened when not in use, so that the runner can be clamped into usual grinding devices. It is therefore desirable that the runner can be straightened again with simple means.
The above described steps according to the invention, for instance biasing means adjustable by means of screw means, obviate the above described problem.
Due to the combination of materials with different coefficients of expansion there occurs a difference in expansion or shrink of the materials in the case of temperature changes. For instance in the combination of an aluminium frame in which a steel runner is arranged, the following phenomenon occurs. A radius in the runner of for instance 20 metres at room temperature will have a radius of curvature at minus 15° C. of about 17 metres. This temperature-dependent radius of curvature is undesirable if it does not correspond to the radius of curvature desired at these temperatures. There therefore exists a need to change the effective coefficient of expansion, locally or otherwise, of an aluminium skate frame in order to thus make it possible to compensate for the deformation due to temperature differences.
The stiffness of a skate frame is also of great importance. Due to the great forces during starting, sprinting and taking of a bend, the skate and the frame have a tendency to deform. This deformation must be limited to a minimum. If a skate is subjected to bending, a small radius of curvature must be arranged in advance both in height and in sideways direction in order to still have the correct radius of curvature in the bend. This has the disagreeable consequence that the straight part of the skate track must be skated with a small radius of curvature, which adversely affects the speed. For these reasons there therefore exists a need for a stiff skate frame.
This need for more stiffness and strength also exists in other constructions, such as for instance in aluminium boat masts, booms and the like. Other applications relate to ladders, for instance fire ladders, aluminium profiles in the building industry, glasshouse construction etc. Supporting aluminium profiles also often have the limitation of insufficient stiffness and strength. The invention provides a solution herefor.
It is noted that particularly the biasing means according to the invention can cause a bending in two directions. For this purpose two push or pull rods are then connected to the profile, this at mutually differing positions relative to the neutral fibre, for instance such that the one rod causes a sideward bending and the other rod a bending in vertical direction.
By arranging carbon rods in the outer wall of a skate frame the stiffness is improved to a significant extent. Carbon fibres have a stiffness which is a factor 3-6 times higher than that of aluminium, while the specific mass amounts to about half thereof. The strength of carbon is 4-10 times that of aluminium. The structure of the elongate metal body can thus be lighter while retaining strength and stiffness.
Another advantage of carbon fibres is that these fibres display a fully elastic behaviour. This in contrast to for instance the aluminium, where the elasticity limit is relatively low and a permanent plastic deformation occurs quite rapidly when there is load. The stiff and strong carbon fibres prevent this plastic deformation of the aluminium.
The reinforcing rod which according to the invention is added to the elongate metal body has in the most general sense better properties than the material of the metal body itself, particularly in respect of strength and stiffness. The gluing of the rod into the cavity takes place for instance with an epoxy glue. Aluminium bodies are preferably anodized with usual methods to thus obtain a suitable gluing surface. Other cleaning and surface treatments, such as for instance chrome-plating, can be used.
A reinforcing rod can have a desired cross-sectional form, for instance a round form or can have another cross section adapted to the geometry of the cavity or the metal body, for instance square, rectangular, polygonal.
The cavity can for instance be arranged completely internally in the body. A cavity can also be partially open to the outside in longitudinal direction, which simplifies the extrusion process for manufacturing the metal body. The opening of such semi-open forms can be situated on the inside or the outside of the profile. In this latter case the reinforcing rod is partly visible on the outside.
In the case of an enclosed cavity in a metal body a reinforcing rod, which is for instance obtained via a pulltrusion process, is pushed into the cavity. The glue can herein be pre-applied to the rod and/or in the cavity.
Another method is to insert the rod into the cavity without glue. By supplying glue to the one open side and sucking on the other side of the cavity (in which the rod is received), the glue can be applied between the wall of the cavity and the reinforcing rod so that it wholly fills the remaining space.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and special features of the invention will now be elucidated with reference to the annexed drawings. Herein:
FIG. 1 is a schematic perspective view of a skate with a frame according to the invention;
FIG. 2 shows the cross section II--II according to FIG. 1 on enlarged scale;
FIGS. 3, 4, 5 and 6 show cross sections through alternative profiled rods embodied as skate frames;
FIG. 7 is a partly broken away perspective view of a skate frame and device for gluing in a reinforcing rod;
FIGS. 8 and 9 show cross sections through other examples of extrusion profiles with a plurality of reinforcing rods in accordance with the teaching of the invention;
FIG. 10 shows a cross section through two coacting profiles for manufacturing a body according to the invention;
FIG. 11 shows a cross section through a variant;
FIG. 12 is a partial side view of a drive shaft according to the invention with torsion- and bending-stiffness;
FIG. 13 is a schematic perspective view of an interrupted profile with continuous reinforcing rods;
FIG. 14 is a schematic perspective partial view of a variant;
FIG. 15 shows a longitudinal cross sectional view of the embodiment according to FIG. 14 during production;
FIG. 16 shows a cross section through yet another embodiment;
FIG. 17 shows a schematic longitudinal section through a variant;
FIG. 18 shows a cross section through another variant;
FIG. 19a shows a cross section through a reinforcing profile;
FIG. 19b shows a section through an aluminium tube for reinforcing;
FIG. 19c shows the assembly of the parts according to FIGS. 19a and 19b with reinforcing rods;
FIG. 20a shows a reinforcing body according to the invention;
FIG. 20b shows a beam reinforced therewith;
FIG. 21a shows an alternative reinforcing body;
FIG. 21b shows an alternative beam reinforced therewith;
FIG. 22 shows a reinforced beam in cross section;
FIG. 23 shows an alternative reinforced beam in cross section;
FIG. 24 shows yet another beam in cross section;
FIG. 25 shows a reinforced tube in cross section;
FIG. 26 is a schematic view of a device for manufacturing a fixedly biased structure according to the invention;
FIG. 27 is a schematic view through a set of windmill blades;
FIG. 28 is a schematic view of a beam to be placed-under strain of three-point bending;
FIG. 29 is a schematic view of a vertical pole clamped on its underside and to be placed under strain of bending along its length;
FIG. 30 shows an example of a composite body with reinforcing rods according to the invention; and
FIG. 31 shows a graphic representation of tension curves of determined carbon fibres and aluminium extrusion material for the purpose of elucidating an important application of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an ice-skate 1. This comprises a shoe 2, a sole support 3 connected to the sole thereof and a heel support 4 connected to the heel. Connected to these supports 3 and 4 is an extruded aluminium profile 5, on the underside of which a runner 7 is glued into a groove 6. The profile 5 shows a downward tapering form and is provided with two cavities respectively 8 and 9 extending in longitudinal direction. The relatively large cavity 8 has the function of reducing the weight of profile 5. The cavity 9 has a cylindrical form in this embodiment. Arranged with small clearance in this cavity 9 is a reinforcing rod consisting of a bundle of continuous carbon fibres extending in longitudinal direction and embedded in a plastic matrix. At both ends of cavity 9 a screw thread is tapped in the wall thereof, into which are placed screws 11, 12 which are operable from outside by means of a tool 10. The screws engage for pressing on the carbon rod 13 in the manner shown in FIG. 2. By rotating the tool 10 as according to arrow 14 the pressure force exerted on rod 13 is increased, whereby as a result of the relatively great pressure strength of this rod 13 relative to the aluminium of the profile 5 this latter is subjected to a bending which is indicated with the dash-dot line 15. The profile and the runner 7 hereby acquire a bent form, the radius of curvature of which is adjustable.
FIGS. 3, 4, 5 and 6 show respectively frames 16, 17, 18, 19 in which the reinforcing rods 13 are arranged. Frames 17, 18, 19 have additional reinforcing rods 20, 21, 22 respectively.
For instance the embodiment according to FIG. 4 offers the possibility of influencing the curvature in the horizontal plane as well as that in the vertical plane. The rod 13 can influence the horizontal curvature in the same manner as described with reference to FIGS. 1 and 2, while the rod 20 influences the curvature in the vertical plane. This embodiment is such that the neutral fibre 23 of the structure is situated at the point of intersection of the vertical plane 24 through rod 20 and the horizontal plane 25 through rod 13. Hereby the bendings caused by rods 13 and 20 are substantially independent of one another.
The structure according to FIG. 5 comprises two cavities accessible via openings 26, in which cavities the rods 13 and 21 are situated. During manufacture the frame 18 can be turned over temporarily in order to pour glue into the cavities for the purpose of gluing rods 13, 21 therein.
Attention is drawn to the fact that the cavity 9 according to FIG. 1 is placed at a distance from the neutral fibre of the profile 5. Rod 13 can thereby only be bent in an inclining plane, which assumes a position between the planes 24 and 25 drawn in FIG. 4.
FIG. 7 shows a profile 27 which bears a strong resemblance to the profile 18 according to FIG. 5, but differs therefrom in that the cavities 28 are separate from the central cavity 29. In this embodiment a carbon rod 13 is first arranged in a cavity 28, a glue reservoir 31 is subsequently connected via a conduit 30 for supplying glue into cavity 28, into which rod 13 is placed beforehand. Glue is subsequently drawn in by means of a suction pump 32, which is connected to the other end of cavity 28 by means of a conduit 33, such that the glue fills the interspace between the wall of cavity 28 and the rod 13. The glue is optionally cured by an increase in temperature. If desired, the open ends of cavities 28 can be covered with a plug.
FIGS. 8 and 9 show cross sections through respective profiles 34 and 35. Profile 34 can for instance serve as sailing boat mast. Reinforcing rods are designated with reference numeral 36.
The profile 35 is an I-beam which is intended as construction element for building structures. These profiles 34, 35 can also be manufactured by extrusion from aluminium.
FIG. 10 shows two partially depicted profiles 41, 42 which can be moved toward one another as according to arrow 43 such that protrusions 44 of profile 42 are inserted into spaces 45 of profile 41 such that cylindrical channels result. Reinforcing rods are placed beforehand in the spaces 45. With suitable means, for instance glue, the profiles 41, 42 are held together such that the reinforcing rods (not shown) are connected to the obtained structure in force-transmitting manner.
FIG. 11 shows a variant in which an elongate body 46 has undercut recesses 47 in which reinforcing rods 48 are prearranged. The recesses 47 are subsequently covered by a plate 49. The profiles according to FIGS. 10 and 11 can be manufactured very suitably by means of pulltrusion. It is important to prevent corrosion between the carbon rod and the material of the relevant profile, in particular aluminium. A complete embedding and sealing relative to the environment can serve for this purpose.
FIG. 12 shows a drive shaft 50 with a very slightly helical form. This helical form is obtained after extrusion of shaft 50 by for instance applying a heavy torsional stress to the initially straight-extruded, tubular drive shaft, whereby a plastic deformation occurs. The drive shaft provided beforehand with reinforcing rods 51, 52 thus obtains in this embodiment a greatly increased one-sided torsion stiffness. A two-sided increase in the torsion stiffness can also be envisaged by arranging reinforcing rods running crosswise. The described manner of manufacture cannot be applied here.
It can be of importance to use a glue for gluing in reinforcing rods which has a high resistance to creep stresses at an increased temperature. An increased resistance can be obtained by adding temperature resistant particles to the glue. These may be metal or ceramic particles. A glue with a high glass transition temperature also provides an increased resistance of the glue connection to creep. It is noted that creep or relaxation occurs in glues and matrix materials in the case of prolonged load at increased temperature.
An epoxy glue can be provided with so-called flexibilizers, whereby shock and peak loads can be absorbed better. In the case of an epoxy glue for instance an increased flexibility is obtained by adding slightly more hardener relative to the resin part than is prescribed for normal applications. The addition of fine rubber particles is also very effective in relation to the desired flexibility.
When reinforcing rods of glass fibre are used, these glass fibres can also serve for data transmission.
Glass can be cast into cavities in extrusion profiles as reinforcing material. In this manner a very good vacuum or pressure through-feed can also be realized.
Profiles can be applied wherein at least a number of cavities extending in longitudinal direction are used for other purposes, for instance data transport, liquid transport or gas transport.
Additional channels can if desired also be used for bringing a profile to and holding thereof at a determined temperature. Particularly in situations where excessively high temperatures can adversely affect the quality of the construction, cooling of an aluminium profile can be realized by causing coolant to flow through the relevant channels.
The internal surface of the longitudinally extending cavity can be pretreated to improve adhesion of an applied glue. The surface can for instance be treated with a solution of sodium hydroxide, potassium hydroxide or the like. These agents dissolve a small portion of the surface, thereby removing the oxide skin which is disadvantageous in obtaining a good adhesion. After pickling with such a caustic soda the surface is washed well with water and then dried. Gluing must take place relatively quickly after this pickling process in order to prevent renewed oxide formation. After the pickling the surface can also be passivated in the usual manner by for instance chrome-plating or anodizing.
By pickling the inner surface of the cavities with caustic soda the inner diameter of the cavity can also be increased. The enlargement obtained is dependent on the duration, concentration and temperature of the caustic soda. The glue gap (see FIG. 7) between the wall of the cavity and the reinforcing rod requires a value with close tolerance. The extrusion process for manufacturing an extruded aluminium profile cannot be performed well in respect of this close tolerance. The cavity can be widened in the described manner by pickling. When the cavities have mutually differing diameters, different pickling times can be prescribed per cavity in order to eventually obtain the nominal diameter everywhere.
FIG. 13 shows an interrupted profile consisting of blocks 53 through which three carbon reinforcing rods 54 extend continuously. In this embodiment blocks 53 can provide the desired positioning of the carbon rods 54 and can be used to discharge the forces to the environment. The application of the structure shown in FIG. 13 is for instance reinforcing existing structures under strain of bending, such as bridges and other frames, for instance the heavily loaded frames of transport means such as trucks.
FIG. 14 shows a beam 55 in which three carbon rods 56 extend in longitudinal direction. Zones 57 pressed plastically inward are arranged from outside to fix the carbon rods 56.
FIG. 15 shows the manner in which these plastic deformations can be arranged. The beam 55 is carried through the pinch between a non-profiled lower roller 58 and a profiled upper roller 59. The form of the profiling of roller 59 is transferred to the beam 55 in the form of the depressions 57.
FIG. 16 shows a variant in which a reinforcing rod 60 is pressed from outside by a screw 61.
FIG. 17 shows a variant in which the outer end of a carbon rod 62 is glued and clamped fixedly by means of a wedge 63. The elongate body 64 has for this purpose a channel 65 with a form widening toward the outside.
FIG. 18 shows a floor part 66 which is embodied as aluminium extrusion part and comprises a flat upper plate 67 which is reinforced on its underside by ribs 68 which are reinforced on their bottom part with carbon rods 69. The plates 67 can be mutually coupled by means of undercut longitudinal recesses 70 and correspondingly formed longitudinal protrusions 71.
FIG. 19a shows a cross-shaped extruded aluminium profile 72 with cavities 73 for receiving reinforcing rods.
FIG. 19b shows an aluminium tube 74.
FIG. 19c shows the assembly of the reinforcing cross 72 and the aluminium tube 74, wherein carbon rods 75 are arranged in cavity 73 by means of glue. A unitary reinforced structure is hereby obtained.
FIG. 20a shows a reinforcing bar 76 into which carbon reinforcing rods 77 are glued. FIG. 20b shows that a beam 78 is reinforced with two such bars 76 which are connected thereto by screw means 178.
FIG. 21a shows an alternative reinforcing bar 79, which can be inserted in longitudinal direction in the manner shown in FIG. 21b in order to reinforce beam 80.
FIG. 22 shows a beam 81 which is reinforced with carbon reinforcing rods 77.
FIG. 23 shows an alternative, wherein a beam 82 is assembled from two equal parts 83. The flanges 841 are mutually connected by for instance bolts (not shown).
FIG. 24 shows a part of a beam 83 in accordance with the teaching of FIG. 11.
FIG. 25 shows a tube 184 reinforced with carbon rods 77. Due to the shown orientation and structure a very strong and light cycle frame can for instance be constructed with a high bending stiffness, in particular in the x and y direction.
FIG. 26 shows schematically the manner in which a very light and very elongate structure with bending stiffness can be manufactured. Between two flanges 85, 86 a number of tubes 186 are positioned in pressure-resistant manner. Carbon rods 87 extend in these aluminium tubes. Non-cured epoxy glue is present in the space between the inner wall of a tube and the carbon rod. The flanges 85, 86 are urged toward one another by the shown screw construction, whereby a pressure stress with associated shortening results in tubes 186. The carbon rod 87 is arranged freely in the inner space and therefore not subjected to this pressure force and associated shortening. Curing of the epoxy glue is subsequently carried out, optionally with a certain increase in temperature. Due to the relaxation there now results a biased construction whereby a pressure force is maintained in the aluminium tube in combination with a corresponding tensile force in the carbon rod. Heating can take place as desired by hot air, hot water or electrical heating, for instance by passing an electric current through the carbon rods. An electric current can also be passed through the aluminium profile.
FIG. 27 shows two windmill blades 88, 89 which are placed at a mutual distance but which are mutually connected by means of continuous carbon rods 90, which also extend in the middle zone. A central block 91 serves for coupling to the blade shaft 92. The block 91 is provided with continuous holes 93 for passage of carbon rods 90.
The blades can for instance consist of aluminium or plastic.
The blades 88, 89 may also consist of mutually coupled parts. What is important is that the carbon reinforcing rods hold together the total structure and provide the necessary tensile strength.
FIG. 29 shows a pole 95 which is clamped on its underside 94 and which can be placed under strain of bending by means of forces designated symbolically with an arrow 96. What can be envisaged here is for instance a mast, for instance a flagpole, a ships mast, a lamppost or the like. Glued-in carbon reinforcing rods of different length are drawn symbolically. These rods 97, 98, 99 respectively provide a reinforcement such that the effective cross-sectional surface of the collective rods along the length of pole 95 varies by and large in accordance with the reinforcement desired at each axial position.
FIG. 28 shows a beam 100 based on the same mechanical principle. The beam 100 supported on its ends is loaded in the middle with a bending force 101. Due to this three-point load the bending moment is zero at the ends of the beam and maximum in the middle. In accordance herewith four reinforcing rods are drawn symbolically, designated respectively from long to short with 102, 103, 104 and 105.
FIG. 30 shows the coupling of profiles 106, 107 placed at a mutual angle. The outer surfaces extending transversely of the connecting seam 108 have a rounded and recessed form and are thus made suitable for gluing in of carbon reinforcing rods.
FIG. 31 shows a graphic representation of four different carbon fibres of the Toray brand and also of an aluminium extrusion material (AlMgSi 1; 6061).
This graphic representation shows that in particular carbon fibre material of the type T800 from the manufacturer Toray combines a very high limit of elasticity of 1.9% with a very high tensile strength, i.e. 5586 Mpa. The modulus of elasticity of this fibre material amounts to 294 Gpa.
The three other fibre types T300, M40J and M46J also have the same favourable properties, albeit to a slightly lesser degree. The application of such fibres as reinforcing rods of the type according to the invention in the automobile manufacturing industry is very suitable in view of the ever increasing demands being made in respect of crash consequences. It is important in crashes that the bodywork remains intact but nevertheless provides the possibility of withstanding the great forces which occur by means of plastic deformations (crush zones).
In normal use a profile reinforced with carbon can already give a considerable weight-saving with improved properties. The aluminium may absorb without any problem as much stretch as is required for the stretch of the reinforcing fibres to utilize the full strength of the fibre material. Full benefit can hereby be derived from the strength and the stretch possibilities of the carbon material. Reference is made in this respect to the graph of FIG. 31.
It is noted that the above mentioned manufacturer Toray also supplies even stronger carbon fibres, for instance of the type T1000. Fibres with a considerably lesser stiffness can also be used, such as the above mentioned glass fibres, aramid fibres or polyethylene fibres. The designer of such structures must then realize that higher demands are then made of the stretch possibilities of the aluminium.
The coefficient of expansion of carbon fibre material is smaller than that of aluminium. The coefficient of expansion of the plastic matrix is however considerably larger than that of aluminium. By now choosing a suitable ratio of the quantity of carbon fibres and the plastic matrix material, a coefficient of expansion can be obtained which is equivalent to that of aluminium. Due to this equivalence of the coefficient of expansion the glue is variably loaded in radial direction either not at all or to a negligible degree in the case of temperature fluctuations, which will result in a longer lifespan.
Other very strong materials can also be glued in, such as special aluminium and/or lithium alloys. Such materials are often difficult to extrude in complicated forms and the strength can often be increased by for instance cold deformation. Known in this respect is the so-called cold-drawn wire. Benefit can here also be derived from the equal coefficients of expansion.
|
The invention relates to an elongate metal body, for instance an aluminium rod with a chosen cross-sectional form manufactured by extrusion. It is a first object of the invention to make an elongate metal body stiffer and stronger without this entailing an increase in weight. In respect of this objective the metal body according to the invention has the feature that the body has at least one cavity extending at least to a considerable degree in longitudinal direction, in which cavity is received a pre-manufactured elongate reinforcing rod, of which at least the ends are coupled to the body in force-transmitting manner.
| 0
|
[0001] Apparatuses and systems consistent with exemplary embodiments relate to fasteners. More particularly, apparatuses consistent with exemplary embodiments relate to fasteners such as rivets configured to attach two bodies together.
SUMMARY
[0002] One or more exemplary embodiments provide a fastener configured to attach or hold two bodies together. More particularly, one or more exemplary embodiments provide a fastener with a retainer portion configured to retain a portion of a body or bodies to which the fastener is attached.
[0003] According to an aspect of an exemplary embodiment, a fastener apparatus for a vehicle is provided. The fastener apparatus for a vehicle includes a head portion; a fastening portion connected to the head portion, the fastening portion configured to fasten a body of the vehicle; and a retaining portion configured to retain a portion of the body of the vehicle after the fastening portion is fastened to the body of the vehicle.
[0004] According to an aspect of another exemplary embodiment, a fastener apparatus is provided. The fastener apparatus includes: a head portion; a fastening portion connected to the head portion, the fastening portion configured to fasten a body; and a retaining portion configured to retain a portion of the body after the fastening portion is fastened to the body.
[0005] The fastener apparatus may also include a rivet comprising the head portion, the fastening portion and the retaining portion.
[0006] The fastening portion may include a cylindrical body.
[0007] The retaining portion may be an interior part of the cylindrical body.
[0008] The interior part of the cylindrical body may be partially hollow from a first end of the cylindrical body to a point that distal from a second end of the cylindrical body.
[0009] The interior part of the cylindrical body may include at least one from among serrations, teeth, notches, and jagged edges.
[0010] The interior part of the cylindrical body may be hollow from a first end of the cylindrical body a second end of the cylindrical body.
[0011] The interior part of the head portion may include a hollow center portion.
[0012] The body may include a polymeric composite material.
[0013] The interior part of the cylindrical body may include a first hollow interior portion and a second hollow interior portion. The first hollow interior portion may have a first diameter larger than a second diameter of the second hollow interior portion.
[0014] The retained portion of the body may include at least one from among a slug, a non-integral portion of the body, and a portion that is disconnected from the body.
[0015] According to an aspect of another exemplary embodiment, a fastener apparatus is provided. The fastener apparatus includes: a fastening portion configured to fasten a body; and a retaining portion configured to retain a portion of the body after the fastening portion is fastened to the body.
[0016] The fastener apparatus may also include a rivet comprising the head portion, the fastening portion and the retaining portion.
[0017] The fastening portion may include a cylindrical body.
[0018] The retaining portion may be an interior part of the cylindrical body.
[0019] The interior part of the cylindrical body may be partially hollow from a first end of the cylindrical body to a point that distal from a second end of the cylindrical body.
[0020] The interior part of the cylindrical body may include at least one from among serrations, teeth, notches, and jagged edges.
[0021] The interior part of the cylindrical body may be hollow from a first end of the cylindrical body a second end of the cylindrical body.
[0022] The body may include a polymeric composite material.
[0023] The interior part of the cylindrical body may include a first hollow interior portion and a second hollow interior portion. The first hollow interior portion may have a first diameter larger than a second diameter of the second hollow interior portion.
[0024] The retained portion of the body may include at least one from among a slug, a non-integral portion of the body, and a portion that is disconnected from the body.
[0025] Other objects, advantages and novel features of the exemplary embodiments will become more apparent from the following detailed description of exemplary embodiments and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 shows a perspective view of a fastener according to an exemplary embodiment;
[0027] FIG. 2 shows a cross-sectional view of a fastener piercing a composite body according to an aspect of an exemplary embodiment;
[0028] FIG. 3 shows a cross-sectional view of a fastener piercing a composite body according to an aspect of another exemplary embodiment; and
[0029] FIGS. 4A and 4B show cross-sectional views of a fastener and a fastener piercing a composite body according to an aspect of another exemplary embodiment.
DETAILED DESCRIPTION
[0030] Fasteners such as rivets are used to attach, bind or tie together separated bodies. One application of a fastener is to tie together parts of a body of a vehicle. As new materials are being used to construct lighter and more fuel efficient vehicles, there is a need for new types of fasteners to attach or hold together vehicle components made of newer materials such as polymeric composites.
[0031] A fastener with a retaining portion will now be described in detail with reference to FIGS. 1-4B of the accompanying drawings in which like reference numerals refer to like elements throughout. The following disclosure will enable one skilled in the art to practice the inventive concept. However, the exemplary embodiments disclosed herein are merely exemplary and do not limit the inventive concept to exemplary embodiments described herein. Moreover, descriptions of features or aspects of each exemplary embodiment should typically be considered as available for aspects of other exemplary embodiments.
[0032] It is also understood that where it is stated herein that a first element is “connected to,” “formed on,” or “disposed on” a second element, the first element may be connected directly to, formed directly on or disposed directly on the second element or there may be intervening elements between the first element and the second element unless it is stated that a first element is “directly” connected to, formed on, or disposed on the second element.
[0033] FIG. 1 shows a view of a fastener 100 according to an exemplary embodiment. Referring to FIG. 1 , a fastener 100 includes a head portion 101 and a fastening portion 102 . One or more of the head portion 101 and the fastening portion 102 may have hollow centers that make up a retaining portion. The head portion 101 may comprise a flat disc, a cylindrical disk, a spherical shape, or semi-spherical shape. The fastening portion 102 may comprise a shaft, a cylinder, a partially hollow cylinder, a hollow cylinder, etc. The cylinder may be circular, rectangular, squared, elliptical, etc., in shape. The interior part of the fastening portion, which may be partially or completely hollow, may make up the retaining portion. The interior part of the cylindrical body may be partially hollow from a first end of the cylindrical body to a point that distal from a second end of the cylindrical body. Here the first end of the cylindrical body is the piercing end that is configured to pierce a body.
[0034] The head portion 101 , the fastening portion 102 , and the retaining portion may integrally form the fastener 100 . In one example, the fastener 100 may be a rivet or other type of fastener. The fastener 100 may be formed by a machining process performed on a compound or material such as a metal. Alternatively, the fastener 100 may be formed by injecting a liquid or a gel compound into a mold and allowing the compound to solidify. However, the fastener 100 is not limited to above discussed processes and may be created using other processes.
[0035] FIG. 2 shows a perspective view of a fastener 200 piercing a composite body 210 according to an aspect of an exemplary embodiment. Referring to FIG. 2 , a fastener 200 includes a head portion 201 and a fastening portion 202 . As shown in FIG. 2 , the head portion 201 and the fastening portion 202 have an interior part that is hollow. The hollow interior part makes up the retaining portion 203 . The retaining portion 203 retains a slug 211 , which is a portion of the body 210 that has partially or fully broken away from the body 210 after the body 210 is pierced by the fastener 200 . The slug 211 may be a non-integral portion of the body 210 . The body may comprise a polymeric composite material.
[0036] FIG. 3 shows a perspective view of a fastener 300 piercing a composite body 310 according to an aspect of another exemplary embodiment. Referring to FIG. 3 , a fastener 300 includes a head portion 301 and a fastening portion 302 . As shown in FIG. 2 , the fastening portion 302 may be a cylindrical body that has an interior part that is partially hollow from one end to a point that distal from a second end of the cylindrical body. The hollow interior part makes up the retaining portion 303 . The retaining portion 303 may include serrations 304 (e.g., teeth, notches, threads or jagged edges). The serrations may be formed by tapping threads into the retaining portion 303 . The retaining portion 303 retains a slug 311 , which is a portion of the body 310 that has partially or fully broken away from the body 310 after the body 310 is pierced by the fastener 300 . The slug 311 may be a non-integral portion of the body 310 . The body may comprise a polymeric composite material (e.g., a thermoplastic composite material, a carbon fiber material, a fiberglass material, etc.).
[0037] FIGS. 4A and 4B show perspective views of a fastener 400 and a fastener 400 piercing a composite body 410 according to an aspect of another exemplary embodiment. Referring to FIG. 4A , a fastener 400 includes a head portion 401 and a fastening portion 402 . The hollow interior part makes up the retaining portion 403 . The retaining portion 403 may include a two-step hollow portion. The first hollow interior portion 404 may have a larger diameter than a second hollow interior portion 405 . The retaining portion 403 with the first hollow interior portion 404 and the second hollow interior portion 405 may be designed so that the fastener can withstand an impact force necessary to pierce one or more bodies while still holding the bodies together. Referring to FIG. 4B , the fastener 400 may pierce a composite body 410 and a slug 411 may be retained in the first hollow interior portion 404 and the second hollow interior portion 405 .
[0038] The fasteners describe above may be used to hold together polymeric composite to polymeric composite materials, metal to polymeric composite materials, etc. In particular, the fasteners described above may hold together a stack of sheets of material, where a composite sheet is at the bottom of the stack of sheets of materials being held together. The other materials in the stack may be different types of materials. The fastener, according to an exemplary embodiment, may be used to pierce through a composite sheet and form a hook to bind or hold the composite sheet to a body or set of sheets. The sheets may include one or more from among a metallic material, a polymeric composite material (e.g., a thermoplastic composite material, a carbon fiber material, a fiberglass material, etc).
[0039] One or more exemplary embodiments have been described above with reference to the drawings. The exemplary embodiments described above should be considered in a descriptive sense only and not for purposes of limitation. Moreover, the exemplary embodiments may be modified without departing from the spirit and scope of the inventive concept, which is defined by the following claims.
|
A fastener is provided. The fastener includes a fastening portion configured to fasten a body; and a retaining portion configured to retain a portion of the body after the fastening portion is fastened to the body. The fastener apparatus may be used to attach composite body materials to a vehicle.
| 5
|
BACKGROUND OF THE INVENTION
As disclosed by the Japanese Publication No. 2002-106697 (FIGS. 1, 2, 4 and 6), for example, a conventional work vehicle is constructed to operate a propelling speed change device automatically to a low speed side and a high speed side in response to loads acting on the engine.
This work vehicle detects an actual engine speed for determining a load acting on the engine. When the actual engine speed lowers, the propelling speed change device is operated to the low speed side. When the actual engine speed rises, the propelling speed change device is operated to the high speed side. By operating the propelling speed change device to the low speed side and high speed side, the actual engine speed is maintained in a set range (i.e. the load acting on the engine is maintained in a set range).
Generally, with a work vehicle, it is necessary to set a proper running speed according to the type of implement connected to the vehicle, and conditions of the operating ground.
SUMMARY OF THE INVENTION
The object of this invention is provide a work vehicle constructed to operate a propelling speed change device to a low speed side and a high speed side according to loads acting on an engine, the vehicle being capable of setting a proper running speed according to working conditions.
The above object is fulfilled, according to one aspect of the invention, by a work vehicle with a speed change device, comprising: a plurality of wheels including at least one driven wheel; an engine for driving said at least one driven wheel; a speed change device provided between said at least one driven wheel and said engine; and an automatic shifting means for operating said speed change device to a lower speed position within an automatic shifting range having a predetermined range and for operating said speed change device up to a speed position said speed change device was in before an operation to the lower speed position was effected, in response to load on said engine, wherein an entirety of said automatic shifting range is changeable to a low speed side and to a high speed side.
Thus, the automatic shifting device is capable of operating the speed change device to a lower speed position within an automatic shifting range having a predetermined range and is capable of operating the speed change device up to a speed position which the speed change device was in before an operation to the lower speed position was effected. Thus, the propelling speed change device is not automatically operated to the low speed side and high speed side beyond the automatic shifting range. And the entire automatic shifting range is changeable to the low speed side and high speed side. Thus, the automatic shifting range may be set appropriately according to working conditions.
The speed change performance of work vehicles can also be improved by providing a mechanism that can widen the automatic shifting range to include more speed positions and narrow the range to include less speed positions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing a transmission system in a transmission case;
FIG. 2 is a view showing a linkage among a shift lever, an up-shift button and a down-shift button, a setting switch and various other components;
FIG. 3 is a hydraulic circuit diagram showing forward and backward clutches, first and second main speed change devices, and so on;
FIG. 4 is a view showing a flow of control in time of operating a forward and backward drive switching lever;
FIG. 5 is a view showing a flow of control in time of pushing the up-shift button and down-shift button in a manual mode;
FIG. 6 is a view showing states of a first to a fourth speed clutches and a low speed and a high speed clutches in time of pushing the up-shift button and down-shift button in the manual mode;
FIG. 7 is a view showing a flow of control for operating the first and second main speed change devices automatically to a low speed side and a high speed side in a load mode;
FIG. 8 is a view showing the first half of a flow of control for operating the first and second main speed change devices automatically to the low speed side and the high speed side in a run mode;
FIG. 9 is a view showing the second half of the flow of control for operating the first and second main speed change devices automatically to the low speed side and the high speed side in the run mode;
FIG. 10 is a view showing a flow of control for setting an automatic speed change range in the load mode (run mode);
FIG. 11 is a view showing the first half of a flow of control for changing the automatic speed change range in the load mode (run mode);
FIG. 12 is a view showing the second half of the flow of control for changing the automatic speed change range in the load mode (run mode);
FIG. 13 is a view showing a relationship between position of a sensitivity adjusting switch, and first and second set values;
FIG. 14 a view showing a flow of control for setting an automatic speed change range in the load mode (run mode) in a different embodiment;
FIG. 15 is a view showing states of a speed indicator in another different embodiment; and
FIG. 16 is a view showing states of a speed indicator in a further embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Next, some embodiments of this invention will be described with reference to the drawings. It should be understood that a combination of a characteristic feature described in a certain embodiment with a characteristic feature described in a different embodiment is, unless a conflict occurs, within the scope of this invention.
[1]
FIG. 1 shows a transmission case 8 of the four-wheel drive type agricultural tractor which is one example of work vehicles. Power of an engine 1 is transmitted to a pair of rear wheels 14 through a forward clutch 5 or a backward clutch 6 , a tubular shaft 7 , a first main speed change device 10 (corresponding to the propelling speed change device), a second main speed change device 11 , an auxiliary speed change device 12 and a rear wheel differential 13 . The power branched off immediately upstream of the rear wheel differential 13 is transmitted to a pair of front wheels 19 through a transmission shaft 15 , a front wheel speed change device 16 of the hydraulic clutch type, a front wheel transmission shaft 17 and a front wheel differential 18 . The power of the engine 1 is transmitted also to a PTO shaft 4 through a transmission shaft 2 , a PTO clutch 3 and a PTO speed change device 9 of the hydraulic multi-plate type.
As shown in FIG. 1 , each of the forward and backward clutches 5 and 6 is the hydraulic multi-plate type having a combination of friction plates (not shown) and a piston (not shown), and is engageable by supplying hydraulic fluid. When the forward clutch 5 is engaged, the power of the engine 1 is transmitted from the forward clutch 5 directly to the tubular shaft 7 to drive the vehicle body forward. When the backward clutch 6 is engaged, the power of the engine 1 is transmitted through the backward clutch 6 and a transmission shaft 20 to the tubular shaft 7 in reversed rotation, to drive the vehicle body backward.
As shown in FIG. 1 , the first main speed change device 10 is the hydraulic clutch type having a first speed clutch 21 , a second speed clutch 22 , a third speed clutch 23 and a fourth speed clutch 24 arranged in parallel, to provide four speeds. By selectively engaging the first to fourth speed clutches 21 - 24 , the power on the tubular shaft 7 is transmitted to a transmission shaft 25 in four speeds.
As shown in FIG. 1 , the second main speed change device 11 is the hydraulic clutch type having a low-speed clutch 26 and a high-speed clutch 27 arranged in parallel. By selectively engaging the low-speed and high-speed clutches 26 and 27 , the power on the transmission shaft 25 is transmitted in two speeds to the auxiliary speed change device 12 . The auxiliary speed change device 12 is the synchromesh type with a slidable shift element 53 for providing two speeds, and is mechanically operable by a shift lever 28 shown in FIG. 2 .
A control unit shown in FIG. 2 has a CPU and memory, receives signals from switches and sensors to be described in this specification, generates control signals for controlling actuators of valves, and transmits the control signals to required components. Thus, even if not expressly described in the specification, each switch, each sensor, and each actuator and the control unit are in signal communication. The memory of the control unit stores one or more programs for executing a control algorism described in this specification.
[2]
A hydraulic circuit for the forward and backward clutches 5 and 6 and first and second main speed change devices 10 and 11 will be described next.
As shown in FIG. 3 , an oil line 30 extending from a pump 29 has, connected thereto, an electromagnetic proportional valve 35 and selector valves 36 a and 37 a of the pilot operated type for the forward and backward clutches 5 and 6 , selector valves 31 a, 32 a, 33 a and 34 a of the pilot operated type for the first to fourth speed clutches 21 - 24 , and electromagnetic proportional valves 38 and 39 for the low-speed and high-speed clutches 26 and 27 .
As shown in FIG. 3 , an oil line 40 branched from the oil line 30 has, connected thereto, a selector valve 42 a of the pilot operated type for a hydraulic clutch 41 for differential locking of the front wheel differential 18 , a selector valve 44 a of the pilot operated type for a hydraulic clutch 43 for differential locking of the rear wheel differential 13 , and selector valves 47 a and 48 a of the pilot operated type for a standard clutch 45 and an accelerating clutch 46 of the front wheel speed change device 16 . The selector valves 31 a - 34 a, 36 a, 37 a, 42 a, 44 a, 47 a and 48 a are biased by springs to drain positions (disengaging positions), and are operated to supply positions (engaging positions) by pilot pressure supplied.
As shown in FIG. 3 , a pilot oil line 50 branches through a reducing valve 49 from the oil line 30 . The pilot oil line 50 is connected to controls of the selector valves 31 a - 34 a, 36 a, 37 a, 42 a, 44 a, 47 a and 48 a. Solenoid operated valves 31 b, 32 b, 33 b, 34 b, 36 b, 37 b, 42 b, 44 b, 47 b and 48 b are connected to the controls. The solenoid operated valves 31 b - 34 b, 36 b, 37 b, 42 b, 44 b, 47 b and 48 b are biased by springs to drain positions (disengaging positions). When the solenoid operated valves 31 b - 34 b, 36 b, 37 b, 42 b, 44 b, 47 b and 48 b are operated to supply positions, pilot pressure is supplied to the controls of the selector valves 31 a - 34 a, 36 a, 37 a, 42 a, 44 a, 47 a and 48 a, to operate the selector valves 31 a - 34 a, 36 a, 37 a, 42 a, 44 a, 47 a and 48 a to supply positions (engaging positions).
[3]
A construction for operating the forward and backward clutches 5 and 6 and first and second main speed change devices 10 and 11 will be described next.
As shown in FIG. 3 , a switch valve 51 is provided for draining pilot pressure oil from the controls of the selector valves 36 a and 37 a. The switch valve 51 is biased to a closed position by a spring, and a clutch pedal 52 is provided for operating the switch valve 51 to an open position. As shown in FIG. 2 , a forward and backward switching lever 59 extends from a base of a steering wheel 58 for steering the front wheels 19 . The switching lever 59 is operable to a forward position F, a backward position R and a neutral position N.
As shown in FIG. 2 , the shift lever 28 is supported to be rockable about a transverse axis on a driving platform of the vehicle body. The shift lever 28 is mechanically linked by a link mechanism 55 to a shift rod 54 for sliding the shift element 53 of the auxiliary speed change device 12 . The shift lever 28 is operable to a neutral position N, a low-speed position L and a high-speed position H, to operate the auxiliary speed change device 12 (shift element 53 ) to a neutral position, a low-speed position and a high-speed position. A position sensor 70 is provided for detecting the operated positions of the shift lever 28 . An up-shift button 61 (corresponding to a manual shifter) and a down-shift button 62 (corresponding to a manual shifter) are arranged vertically on the left side of the shift lever 28 . When the up-shift button 61 and down-shift button 62 are pushed, the first and second main speed change devices 10 and 11 are operated as described in section [6] hereinafter.
As shown in FIG. 2 , the driving platform includes a seven-segment speed indicator 64 for indicating shift positions (first to eighth speeds) of the first and second main speed change devices 10 and 11 , a forward lamp 65 and a backward lamp 66 for indicating which of the forward and backward clutches 5 and 6 is engaged, and a neutral lamp 67 for indicating that the shift lever 28 or forward and backward switching lever 59 is in the neutral position N. As shown in FIG. 3 , pressure sensors 74 are provided for detecting a working pressure of the forward and the backward clutches 5 and 6 , and the forward lamp 65 and backward lamp 66 are lit based on detection by the pressure sensor 74 .
As shown in FIG. 2 , a setting switch 68 (corresponding to a manual selector) is provided to be manually operable. The setting switch 68 is operable to three positions including a manual mode position shown in FIG. 2 , a run mode position when pushed in a D 1 direction, and a load mode position when pushed in a D 2 direction. When the setting switch 68 is pushed to the manual mode position, run mode position and load mode position, a manual mode, a run mode (corresponding to the automatic mode) and a load mode (corresponding to the automatic mode) are set as described in sections [6], [7], [8] and [9] hereinafter.
[4]
Next, operation of the forward and backward switching lever 59 will be described with reference to FIG. 4 .
When the forward and backward switching lever 59 is operated to the forward position F (step S 1 ), a control current is supplied to the solenoid controlled valve 36 b to operate the selector valve 36 a to the supply position, which engages the forward clutch 5 (step S 2 ) and lights the forward lamp 65 (step S 3 ). When the forward and backward switching lever 59 is operated to the backward position R (step S 1 ), the control current is supplied to the solenoid controlled valve 37 b to operate the selector valve 37 a to the supply position, which engages the backward clutch 6 (step S 4 ), lights the backward lamp 66 (step S 5 ), and intermittently sounds a buzzer 71 shown in FIG. 2 (step S 6 ).
When the forward and backward switching lever 59 is operated to the neutral position N (step S 1 ), the control current to the solenoid controlled valves 36 b and 37 b is stopped to operate the selector valves 36 a and 37 a to the drain positions, which disengages the forward and backward clutches 5 and 6 (step S 7 ) and lights the neutral lamp 67 (step S 8 ). When the clutch pedal 52 is depressed, the switch valve 51 is operated to the open position to operate the selector valves 36 a and 37 a to the drain positions, which disengages the forward and backward clutches 5 and 6 , and lights the neutral lamp 67 . When both of the forward and backward clutches 5 and 6 are disengaged as above, power transmission through the forward and backward clutches 5 and 6 is broken to stop the vehicle body.
[5]
Next, operation of the auxiliary speed change device 12 by the shift lever 28 will be described.
When the shift lever 28 is operated to the neutral position N, the auxiliary speed change device 12 (shift element 53 ) is operated to the neutral position. When the shift lever 28 is operated to the low-speed position L, the auxiliary speed change device 12 (shift element 53 ) is operated to the low-speed position. When the shift lever 28 is operated to the high-speed position H, the auxiliary speed change device 12 (shift element 53 ) is operated to the high-speed position.
When, for example, the shift lever 28 is operated to the neutral position N, with the forward and backward switching lever 59 operated to the forward position F (i.e. with the forward clutch 5 engaged, and the backward clutch 6 disengaged), the selector valve 36 a is operated to the drain position by the solenoid controlled valve 36 b, based on the detection by the position sensor 70 , to disengage the forward clutch 5 .
Subsequently, when the shift lever 28 is operated to the low-speed position L (or high-speed position H), the selector valve 36 a is operated to the supply position by the solenoid controlled valve 36 b, based on the detection of the position sensor 70 , and the forward clutch 5 is gradually engaged by the electromagnetic proportional valve 35 .
When the shift lever 28 is operated to the neutral position N and to the low-speed position L (or high-speed position H) as described above, with the forward and backward switching lever 59 operated to the backward position R (i.e. with the backward clutch 6 engaged, and the forward clutch 5 disengaged), the backward clutch 6 is disengaged and then engaged, as is the forward clutch 5 .
[6]
Next, a state where the setting switch 68 is pushed to the manual mode position will be described with reference to FIG. 5 (this corresponding to the manual speed change device).
When the setting switch 68 is pushed to the manual mode position, the manual mode is set. As shown in FIG. 1 , the first main speed change device 10 can provide four speeds, and the second main speed change device 11 can provide two speeds. Thus, the first and second main speed change devices 10 and 11 together can provide eight speeds. When the low-speed clutch 26 is engaged, the first to fourth speed clutches 21 - 24 correspond to shift positions for the first to fourth speeds. When the high-speed clutch 27 is engaged, the first to fourth speed clutches 21 - 24 correspond to shift positions for the fifth to eighth speeds.
As shown in FIGS. 2 and 3 , the first to fourth speed clutches 21 - 24 and the low-speed and high-speed clutches 26 and 27 have pressure sensors 63 and 74 for detecting working pressure, respectively. The pressure sensors 63 and 74 detect a current shift position of the first and second main speed change devices 10 and 11 (i.e. one of the first to eighth speeds). The shift position detected of the first and second main speed change devices 10 and 11 is displayed on the speed indicator 64 .
Assume that, in the above state, the up-shift button 61 or down-shift button 62 is pushed (steps S 11 and S 12 ). When the up-shift button 61 is pushed (step S 11 ), as shown in a solid line A 1 (point of time B 1 ) in FIG. 6 , one of the first to fourth speed clutches 21 - 24 next higher than the current shift position of the first and second main speed change devices 10 and 11 begins to be engaged by a corresponding one of the solenoid controlled valves 31 b - 34 b (step S 13 ). When the down-shift button 62 is pushed (step S 12 ), one of the first to fourth speed clutches 21 - 24 next lower than the current shift position of the first and second main speed change devices 10 and 11 begins to be engaged by a corresponding one of the solenoid controlled valves 31 b - 34 b (step S 14 ).
When the shift lever 28 is in the low-speed position L or high-speed position H (step S 15 ), substantially simultaneously with steps S 13 and S 14 , as shown in a solid line A 2 (point of time B 1 ) in FIG. 6 , the working pressure of the low-speed or high-speed clutch 26 or 27 engaged is lowered from the working pressure P 2 for engagement to a predetermined low pressure P 3 by the electromagnetic proportional valve 38 or 39 (step S 16 ). When a change is made in this case from the shift position for the fourth speed to the shift position for the fifth speed, the working pressure of the low-speed clutch 26 is reduced to zero, and the working pressure of the high-speed clutch 27 is raised from zero to the predetermined low pressure P 3 . Conversely, when a change is made from the shift position for the fifth speed to the shift position for the fourth speed, the working pressure of the high-speed clutch 27 is reduced to zero, and the working pressure of the low-speed clutch 26 is raised from zero to the predetermined low pressure P 3 .
As shown in the solid line A 1 (from point of time B 2 to point of time B 3 ) in FIG. 6 , the working pressure of the next higher or lower one of the first to fourth speed clutches 21 - 24 begins to be raised by one of the solenoid controlled valves 31 b - 34 b to the working pressure P 1 for engagement. Simultaneously, as shown in a long dashed short dashed line A 3 (from point of time B 2 to point of time B 3 ) in FIG. 6 , the working pressure of one of the first to fourth speed clutches 21 - 24 operative before the up-shift button 61 or down-shift button 62 was pressed begins to be lowered by one of the solenoid controlled valves 31 b - 34 b from the working pressure P 1 for engagement to zero (step S 17 ).
When the shift lever 28 is in the low-speed position L or high-speed position H (step S 18 ), as shown in the solid line A 2 (from point of time B 3 to point of time B 4 ) in FIG. 6 , the working pressure of the low-speed or high-speed clutch 26 or 27 is gradually raised from the predetermined low pressure P 3 by the electromagnetic proportional valve 38 or 39 (step S 19 ). As a result, power begins to be transmitted from the next higher or lower one of the first to fourth speed clutches 21 - 24 through the low-speed or high-speed clutch 26 or 27 . When the pressure sensor 63 detects the working pressure of the low-speed or high-speed clutch 26 or 27 having reached the working pressure P 2 for engagement as at point of time B 4 of the solid line A 2 in FIG. 6 (step S 20 ), it is determined that the shifting operation based on the pushing of the up-shift button 61 or down-shift button 62 is completed. A speed position of the first and second main speed change devices 10 and 11 resulting from the shifting operation is displayed on the speed indicator 64 (step S 21 ). The buzzer 71 is sounded once to inform the operator of the end of the shifting operation (step S 22 ). Then, the operation moves to step S 11 to be ready for a next shifting operation based on pushing of the up-shift button 61 or down-shift button 62 .
When the shift lever 28 is in the neutral position N (steps S 15 and S 18 ), the auxiliary speed change device 12 (shift element 53 ) is operated to the neutral position, and the vehicle stands still. When the up-shift button 61 or down-shift button 62 is pushed, with the shift lever 28 placed in the neutral position N (steps S 11 and S 12 ), the first and second main speed change devices 10 and 11 (first to fourth speed clutches 21 - 24 , and the low-speed and high-speed clutches 26 and 27 ) are operated for a one-step higher or lower speed as described above (steps S 13 , S 14 and S 17 ). A speed position of the first and second main speed change devices 10 and 11 resulting from the shifting operation is displayed on the speed indicator 64 (step S 21 ), and the buzzer 71 is sounded once (step S 22 ).
In this case, since the vehicle is standing still, the operation for changing the working pressure of the low-speed or high-speed clutch 26 or 27 to the predetermined low pressure P 3 as in steps S 16 and S 19 is not carried out, nor the operation for changing to the working pressure P 2 for engagement (steps S 15 and S 18 ).
[7]
Next, a state where the setting switch 68 is pushed to the load mode position will be described with reference to FIG. 7 .
When the setting switch 68 is pushed to the load mode position, the load mode is set. In the load mode in which the vehicle engages in a cultivating operation with a plow (not shown), a subsoiler (not shown) or the like, the first and second main speed change devices 10 and 11 are automatically operated to a low speed side and a high speed side in an automatic shifting range R of the load mode as described hereinafter according to ups and downs of an operating ground, variations in soil texture and so on.
As shown in FIGS. 1 and 2 , a hand accelerator lever 73 is provided to be manually operable to set an accelerator opening for the engine 1 , and an opening sensor 75 of the potentiometer type is provided for detecting an operative position of the hand accelerator lever 73 . Further, a rotational frequency sensor 72 is provided for detecting an actual number of rotations N 2 of the engine 1 . A relationship is determined in advance between the number of rotations of the engine 1 in unloaded condition (i.e. a state in which the engine 1 is free from a load, with the forward and backward clutches 5 and 6 are disengaged, and the PTO clutch 3 is disengaged) and detection value of the opening sensor 75 (i.e. operative position of the hand accelerator lever 73 ). From the detection value of the opening sensor 75 (operative position of the hand accelerator lever 73 ), the number of rotations of the engine 1 in the unloaded condition is determined as a set number of rotations N 1 of the engine 1 (step S 31 ).
As described in section [12] hereinafter, the automatic shifting range R of the load mode is set to two stages, three stages or four stages. A shift position of the first and second main speed change devices 10 and 11 in time of the setting switch 68 being pushed to the load mode position is set as a high speed limit position RH in the automatic shifting range R of the load mode (step S 32 ). The shift position of the first and second main speed change devices 10 and 11 (the high speed limit position RH in the automatic shifting range R of the load mode) is displayed on the speed indicator 64 (step S 33 ), and the speed indicator 64 is lit (step S 34 ).
After step S 32 , a low speed limit position RL in the automatic shifting range R of the load mode is set based on the width of the automatic shifting range R of the load mode described in section [12] hereinafter (step S 35 ). When, for example, the fourth speed position is set as the high speed limit position RH of the automatic shifting range R of the load mode, and the width of the automatic shifting range R of the load mode is three stages, the second speed position is set as the low speed limit position RL of the automatic shifting range R of the load mode. In this case, where the low speed limit position RL of the automatic shifting range R of the load mode becomes lower than the first speed position (step S 36 ), the first speed position is set as the low speed limit position RL of the automatic shifting range R of the load mode (step S 37 ).
The actual number of rotations N 2 of the engine 1 is detected (step S 38 ), and a difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is determined (step S 39 ). When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is large, it can be determined that a large load is acting on the engine 1 and has greatly reduced the actual number of rotations N 2 of the engine 1 . When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is small, it can be determined that a small load is acting on the engine 1 and has little reduced the actual number of rotations N 2 of the engine 1 .
As shown in FIG. 13 , a first preset value N 11 and a second preset value N 12 are set for the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 . When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is greater than the first preset value N 11 (step S 40 ), it can be determined that the actual number of rotations N 2 of the engine 1 has reduced greatly. Then, steps S 14 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next lower speed (step S 43 ).
In this case, when the set number of rotations N 1 of the engine 1 is less than the preset value N 23 (e.g. 1,300 rpm) (step S 41 ), or a shift position of the first and second main speed change devices 10 and 11 prior to the above operation is the low speed limit position RL in the automatic shifting range R of the load mode (step S 42 ), the first and second main speed change devices 10 and 11 are not operated for the next lower speed, but are retained in the shift position prior to the above operation.
When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes less than the second preset value N 12 (step S 40 ), it can be determined that the actual number of rotations N 2 of the actual engine 1 has little reduced. Then, steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next higher speed (step S 46 ).
In this case, when the set number of rotations N 1 of the engine 1 is less than the preset value N 26 (e.g. 1,600 rpm) (step S 44 ), or a shift position of the first and second main speed change devices 10 and 11 prior to the above operation is the high speed limit position RH in the automatic shifting range R of the load mode (step S 45 ), the first and second main speed change devices 10 and 11 are not operated for the next higher speed, but are retained in the shift position prior to the above operation.
After steps S 40 -S 46 , the shift position of the first and second main speed change devices 10 and 11 is displayed on the speed indicator 64 (step S 47 ). In this case, when the shift position of the first and second main speed change devices 10 and 11 is the high-speed limit position RH in the automatic shifting range R of the load mode, the speed indicator 64 is lit (steps S 48 and S 49 ). When the shift position of the first and second main speed change devices 10 and 11 is not the high-speed limit position RH in the automatic shifting range R of the load mode, the speed indicator 64 is blinked (steps S 48 and S 50 ).
In the load mode, as described above, based on the set number of rotations N 1 of the engine 1 , the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 , and the first and second preset values N 11 and N 12 , the first and second main speed change devices 10 and 11 are automatically operated to the low speed side or high speed side in the automatic shifting range R of the load mode (the above corresponding to the automatic shifting device).
In this case, when the shift lever 28 is operated from the low-speed position L to the high-speed position H or from the high-speed position H to the low-speed position L, or when the setting switch 68 is pushed to the load mode position once again, with the first and second main speed change devices 10 and 11 automatically operated to the low speed side or high speed side in the automatic shifting range R of the load mode, the shift position of the first and second main speed change devices 10 and 11 is set again as the high-speed limit position RH in the automatic shifting range R of the load mode, and the operation moves to step S 33 .
[8]
Next, the first half of a state where the setting switch 68 is pushed to the run mode position will be described with reference to FIG. 8 .
When the setting switch 68 is pushed to the run mode position, the run mode is set. In the run mode in which the vehicle engages in a running operation towing a trailer (not shown) or the like, the first and second main speed change devices 10 and 11 are automatically operated to a low speed side and a high speed side in an automatic shifting range R of the run mode as described hereinafter according to operation of the hand accelerator lever 73 or variations in the actual number of rotations N 2 of the engine 1 in an uphill run.
As in the load mode described in section [7] above, from the detection value of the opening sensor 75 (operative position of the hand accelerator lever 73 ), the number of rotations of the engine 1 in the unloaded condition is determined as a set number of rotations N 1 of the engine 1 (step S 51 ). As described in section [12] hereinafter, the automatic shifting range R of the run mode is set to two stages, three stages or four stages. A shift position of the first and second main speed change devices 10 and 11 in time of the setting switch 68 being pushed to the run mode position is set as a high speed limit position RH in the automatic shifting range R of the run mode (step S 52 ). The shift position of the first and second main speed change devices 10 and 11 (the high speed limit position RH in the automatic shifting range R of the run mode) is displayed on the speed indicator 64 (step S 53 ), and the speed indicator 64 is lit (step S 54 ).
After the high speed limit position RH in the automatic shifting range R of the run mode is set, a low speed limit position RL in the automatic shifting range R of the run mode is set based on the width of the automatic shifting range R of the run mode described in section [12] hereinafter (step S 55 ). When, for example, the fourth speed position is set as the high speed limit position RH of the automatic shifting range R of the run mode, and the width of the automatic shifting range R of the run mode is three stages, the second speed position is set as the low speed limit position RL of the automatic shifting range R of the run mode. In this case, where the low speed limit position RL of the automatic shifting range R of the run mode becomes lower than the first speed position (step S 56 ), the first speed position is set as the low speed limit position RL of the automatic shifting range R of the run mode (step S 57 ).
The actual number of rotations N 2 of the engine 1 is detected (step S 58 ), and a difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is determined (step S 59 ). When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is large, it can be determined that a large load is acting on the engine 1 and has greatly reduced the actual number of rotations N 2 of the engine 1 .
As shown in FIG. 13 , the first preset value N 11 is set for the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 . When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is greater than the first preset value N 11 (step S 60 ), it can be determined that the actual number of rotations N 2 of the engine 1 has reduced greatly. Then, steps S 14 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next lower speed (step S 63 ).
In this case, when the set number of rotations N 1 of the engine 1 is less than the preset value N 23 (e.g. 1,300 rpm) (step S 61 ), or a shift position of the first and second main speed change devices 10 and 11 prior to the above operation is the low speed limit position RL in the automatic shifting range R of the run mode (step S 62 ), the first and second main speed change devices 10 and 11 are not operated for the next lower speed, but are retained in the shift position prior to the above operation.
After steps S 60 -S 63 , the shift position of the first and second main speed change devices 10 and 11 is displayed on the speed indicator 64 (step S 64 ). In this case, when the shift position of the first and second main speed change devices 10 and 11 is the high-speed limit position RH in the automatic shifting range R of the run mode, the speed indicator 64 is lit (steps S 65 and S 66 ). When the shift position of the first and second main speed change devices 10 and 11 is not the high-speed limit position RH in the automatic shifting range R of the run mode, the speed indicator 64 is blinked (steps S 65 and S 67 ).
[9]
Next, the second half of the state where the setting switch 68 is pushed to the run mode position will be described with reference to FIGS. 8 and 9 .
When, in step S 60 described in section [8] above, the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is less than the first preset value N 11 , and the hand accelerator lever 73 is not operated (step S 68 ), the first and second main speed change devices 10 and 11 are not operated.
When, in step S 60 described in section [8] above, the hand accelerator lever 73 is operated to a high rotation side at low speed (step S 68 ), the set number of rotations N 1 of the engine 1 is less than a preset value N 28 (e.g. 2,400 rpm) (step S 69 ), the set number of rotations N 1 of the engine 1 is equal to or greater than a preset value N 22 (e.g. 1,200 rpm) and less than a preset value N 24 (e.g. 1,400 rpm) (step S 70 ), and the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes less than a preset value N 4 (e.g. 100 rpm) (step S 73 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next higher speed (step S 75 ).
Next, when the set number of rotations N 1 of the engine 1 is equal to or greater than the above preset value N 24 (e.g. 1,400 rpm) and less than the preset value N 26 (e.g. 1,600 rpm) (step S 71 ), and the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes less than the preset value N 4 (e.g. 100 rpm) (step S 73 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a further higher speed (step S 75 ). Next, when the set number of rotations N 1 of the engine 1 is equal to or greater than the preset value N 26 (e.g. 1,600 rpm) and less than the preset value N 28 (e.g. 2,400 rpm) (step S 72 ), and the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes less than the preset value N 4 (e.g. 100 rpm) (step S 73 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a still higher speed (step S 75 ).
When, in step S 60 described in section [8] above, the hand accelerator lever 73 is operated to the high rotation side at high speed (step S 68 ), the set number of rotations N 1 of the engine 1 is equal to or greater than the preset value N 28 (e.g. 2,400 rpm) (step S 76 ), and the actual number of rotations N 2 of the engine 1 is equal to or greater than a preset value N 21 (e.g. 1,100 rpm) and less than a preset value N 23 (e.g. 1,300 rpm) (step S 77 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next higher speed (step S 75 ). Next, when the actual number of rotations N 2 of the engine 1 becomes equal to or greater than the preset value N 23 (e.g. 1,300 rpm) and less than a preset value N 25 (e.g. 1,500 rpm) (step S 78 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a further higher speed (step S 75 ).
Next, when the actual number of rotations N 2 of the engine 1 becomes equal to or greater than the set number of rotations N 1 (e.g. 1,500 rpm) of the engine 1 and less than a preset value N 27 (e.g. 2,300 rpm) (step S 79 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a still higher speed (step S 75 ). Next, when the set actual number of rotations N 2 of the engine 1 is equal to or greater than the preset value N 27 (e.g. 2,300 rpm) (step S 80 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a still higher speed (step S 75 ).
In this case, when, in steps S 68 -S 73 and S 76 -S 80 , the shift position of the first and second main speed change devices 10 and 11 prior to the operation is the high-speed limit position RH in the automatic shifting range R of the run mode (step S 74 ), the first and second main speed change devices 10 and 11 are not operated for a next higher speed, but are retained in the shift position prior to the operation. After the above steps S 68 -S 80 , the operation moves to step S 64 in FIG. 8 .
In the run mode, as described in sections [8] and [9] above, based on the set number of rotations N 1 of the engine 1 , the actual number of rotations N 2 of the engine 1 , the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 , the first preset value N 11 , and operation of the hand accelerator lever 73 , the first and second main speed change devices 10 and 11 are automatically operated to the low speed side or high speed side in the automatic shifting range R of the run mode (the above corresponding to the automatic shifting device).
In this case, when the shift lever 28 is operated from the low-speed position L to the high-speed position H or from the high-speed position H to the low-speed position L, or when the setting switch 68 is pushed to the run mode position once again, with the first and second main speed change devices 10 and 11 automatically operated to the low speed side or high speed side in the automatic shifting range R of the run mode, the shift position of the first and second main speed change devices 10 and 11 is set again as the high-speed limit position RH in the automatic shifting range R of the run mode, and the operation moves to step S 53 in FIG. 8 .
[10]
Operation for setting the first and second preset values N 11 and N 12 (see sections [7], [8] and [9] above) by a sensitivity adjusting switch 76 will be described next.
A dial type sensitivity adjusting switch 76 is provided as shown in FIG. 2 . The sensitivity adjusting switch 76 is operable to set the first preset value N 11 (solid line A 4 ) and second preset value N 12 (solid line A 5 ) as shown in FIG. 13 . The first preset value N 11 (solid line A 4 ) and second preset value N 12 (solid line A 5 ) determine an “operating range for the high speed side”, a “standard range” and an “operating range for the low speed side”.
Thus, when, as described in sections [7], [8] and [9] above, the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes equal to or greater than the first preset value N 11 “operating range for the low speed side”, the first and second main speed change devices 10 and 11 are operated for a next lower speed. When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 is between the first and second preset values N 11 and N 12 (“standard region”), the first and second main speed change devices 10 and 11 are not operated for a lower speed and higher speed. When the difference N 3 between the set number of rotations N 1 of the engine 1 and the actual number of rotations N 2 of the engine 1 becomes less than the second preset value N 12 “operating range for the high speed side”, the first and second main speed change devices 10 and 11 are operated for a next higher speed.
As shown in FIG. 13 , when the sensitivity adjusting switch 76 is in an operation range H 1 , the first preset value N 11 is maintained at “N 35 ” (“N 35 ” means a value shown by N 35 ), and the second preset value N 12 at “N 33 ”. When the sensitivity adjusting switch 76 is in an operation range H 2 , the first preset value N 11 remains at “N 35 ”, but the second preset value N 12 is changed linearly in a small range between “N 33 ” and “N 34 ” according to an operative position of the sensitivity adjusting switch 76 . In this case, the values are in a relationship N 33 <N 34 <N 35 .
As shown in FIG. 13 , when the sensitivity adjusting switch 76 is in an operation range H 3 , the second preset value N 12 is changed linearly in a range between “N 31 ” and “N 33 ” according to an operative position of the sensitivity adjusting switch 76 . In this case, the values are in a relationship N 31 <N 33 . The difference between “N 31 ” and “N 33 ” is larger than that between “N 33 ” and “N 34 ” (the rate of change of the second preset value N 12 (solid line A 5 ) is higher in the operation range H 3 than in the operation range H 2 ).
As shown in FIG. 13 , when the sensitivity adjusting switch 76 is in an operation range H 4 , the second preset value N 12 is set to “0”. Thus, with the sensitivity adjusting switch 76 is in the operation range H 4 and the second preset value N 12 set to “0”, the first and second main speed change devices 10 and 11 are not operated to the high speed side.
As shown in FIG. 13 , when the sensitivity adjusting switch 76 is in the operation ranges H 3 and H 4 , the first preset value N 11 is changed linearly in a range between “N 32 ” and “N 35 ” according to an operative position of the sensitivity adjusting switch 76 . In this case, the values are in a relationship 0<N 31 <N 32 <N 33 <N 34 <N 35 . The difference between “N 32 ” and “N 35 ” is larger than those between “N 33 ” and “N 34 ” and between “N 31 ” and “N 33 ” (the rate of change of the first preset value N 11 (solid line A 4 ) in the operation ranges H 3 and H 4 is higher than those of the second preset value N 12 (solid line A 5 ) in the operation range H 2 and operation range H 3 ).
[11]
A first automatic deceleration control and a second automatic deceleration control performed in the load mode and run mode described in sections [7], [8] and [9] hereinbefore will be described next.
The agricultural tractor has lift arms (not shown) at the rear of the vehicle body for raising and lowering a link mechanism (not shown). A working implement (e.g. a plough, subsoilder or rotary tiller) is connected to the link mechanism. The tractor makes a turn at an end of an operating field with the working implement raised from the ground.
When a manual control device (not shown) for operating the lift arms (e.g. a lift lever or lift switch) is operated to raise the lift arm or when the lift arms are in an upper limit position of a range of vertical movement, in the load mode (run mode) described in sections [7], [8] and [9] hereinbefore, the operation to the high speed side of the first and second speed change devices 10 and 11 is prohibited, and the first and second speed change devices 10 and 11 are operated to the low speed side by a first predetermined deceleration number of speeds (see section [12] hereinafter) in the automatic shifting range R of the load mode (run mode) (the above corresponding to the first automatic deceleration control).
In this case, where the first predetermined deceleration number of speeds requires the first and second speed change devices 10 and 11 to be operated to the low speed side beyond the low speed limit position RL in the automatic shifting range R of the load mode (run mode), the decelerating operation of the first and second speed change devices 10 and 11 will stop at the low speed limit position RL in the automatic shifting range R of the load mode (run mode).
Assume, for example, the hand accelerator lever 73 is operated to the low rotation side in time of vehicle turning or slowdown, the set number of rotations N 1 of the engine 1 is less than a preset value (e.g. 1,000 rpm), and the actual number of rotations N 2 of the engine 1 is less than a preset value (e.g. 2,300 rpm). In this case, the first and second speed change devices 10 and 11 are operated to the low speed side by a second predetermined deceleration number of speeds (see section [12] hereinafter) in the automatic shifting range R of the load mode (run mode) (the above corresponding to the second automatic deceleration control).
In this case, where the second predetermined deceleration number of speeds requires the first and second speed change devices 10 and 11 to be operated to the low speed side beyond the low speed limit position RL in the automatic shifting range R of the load mode (run mode), the decelerating operation of the first and second speed change devices 10 and 11 will stop at the low speed limit position RL in the automatic shifting range R of the load mode (run mode).
[12]
A state of setting the width of the automatic shifting range R of the load mode (run mode) described in sections [7], [8] and [9] hereinbefore to two speeds, three speeds or four speeds, and a state of setting the first and second predetermined deceleration numbers of speeds for the first and second automatic deceleration controls described in section [11] above, will be described next with reference to FIG. 10 .
When, with the shift lever 28 placed in the neutral position N, and after pushing the setting switch 68 to the load mode position (in D 2 direction), a long pushing operation E 1 (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction, the buzzer 71 sounds once, and the speed indicator 64 blinks while displaying “L” indicating a setting mode for the load mode (step S 81 ). In this state, the setting mode for the load mode remains unestablished. A pushing operation E 2 in D 2 direction of the setting switch 64 causes the speed indicator 64 to blink while displaying “P” indicating a setting mode for the first automatic deceleration control (step S 82 ) (the setting mode for the first automatic deceleration control also being unestablished).
In the state noted above where the setting mode for the load mode is unestablished (step S 81 ) and the setting mode for the first automatic deceleration control also unestablished (step S 82 ), each pushing operation E 2 in D 2 direction of the setting switch 64 causes an alternate display of the unestablished state of the setting mode for the load mode (step S 81 ) and the unestablished state of the setting mode for the first automatic deceleration control (step S 82 ).
When, in the state noted above where the setting mode for the load mode is unestablished (step S 81 ), a long pushing operation E 3 (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction, the buzzer 71 sounds once, and the setting mode for the load mode is established (step S 83 ). In step S 83 , the speed indicator 64 blinks while displaying “2”. Each pushing operation E 4 in D 2 direction of the setting switch 64 causes the speed indicator 64 to repeat in cycles the state of blinking while displaying “2”, a state of blinking while displaying “3” and a state of blinking while displaying “4”.
When, in step S 83 , a long pushing operation E 5 (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction, the buzzer 71 sounds once, the number (“2”, “3” or “4”) then displayed on the speed indicator 64 is set as the width of the automatic shifting range R of the load mode, and the speed indicator 64 becomes a continuously lit state (step S 84 ).
When, in the state noted above where the setting mode for the first automatic deceleration control is unestablished (step S 82 ), a long pushing operation E 6 (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction, the buzzer 71 sounds once, and the setting mode for the first automatic deceleration control is established (step S 85 ). In step S 85 , the speed indicator 64 blinks while displaying “0”. Each pushing operation E 7 in D 2 direction of the setting switch 64 causes the speed indicator 64 to repeat in cycles the state of blinking while displaying “0”, a state of blinking while displaying “1”, a state of blinking while displaying “2” and a state of blinking while displaying “3”.
When, in step S 85 , a long pushing operation E 8 (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction, the buzzer 71 sounds once, the number (“0”, “1”, “2” or “3”) then displayed on the speed indicator 64 is set as the first predetermined deceleration number of speeds, and the speed indicator 64 becomes a continuously lit state (step S 86 ). In this case, when “0” is set as the first predetermined deceleration number of speeds, the first automatic deceleration control will not be performed.
When, with the shift lever 28 placed in the neutral position N, and after pushing the setting switch 68 to the run mode position (in D 1 direction), a long pushing operation E 9 (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction, the buzzer 71 sounds once, and the speed indicator 64 blinks while displaying “r” indicating a setting mode for the run mode (step S 87 ). In this state, the setting mode for the run mode remains unestablished. A pushing operation E 10 in D 1 direction of the setting switch 64 causes the speed indicator 64 to blink while displaying “A” indicating a setting mode for the second automatic deceleration control (step S 88 ) (the setting mode for the second automatic deceleration control also being unestablished).
In the state noted above where the setting mode for the run mode is unestablished (step S 87 ) and the setting mode for the second automatic deceleration control also unestablished (step S 88 ), each push operation E 10 in D 1 direction of the setting switch 64 causes an alternate display of the unestablished state of the setting mode for the run mode (step S 87 ) and the unestablished state of the setting mode for the second automatic deceleration control (step S 88 ).
When, in the state noted above where the setting mode for the run mode is unestablished (step S 87 ), a long pushing operation E 11 (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction, the buzzer 71 sounds once, and the setting mode for the run mode is established (step S 89 ). In step S 89 , the speed indicator 64 blinks while displaying “2”. Each pushing operation E 12 in D 1 direction of the setting switch 64 causes the speed indicator 64 to repeat in cycles the state of blinking while displaying “2”, a state of blinking while displaying “3” and a state of blinking while displaying “4”.
When, in step S 89 , a long pushing operation E 13 (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction, the buzzer 71 sounds once, the number (“2”, “3” or “4”) then displayed on the speed indicator 64 is set as the width of the automatic shifting range R of the run mode, and the speed indicator 64 becomes a continuously lit state (step S 90 ).
When, in the state noted above where the setting mode for the second automatic deceleration control is unestablished (step S 88 ), a long pushing operation E 14 (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction, the buzzer 71 sounds once, and the setting mode for the second automatic deceleration control is established (step S 91 ). In step S 91 , the speed indicator 64 blinks while displaying “0”. Each pushing operation E 15 in D 1 direction of the setting switch 64 causes the speed indicator 64 to repeat in cycles the state of blinking while displaying “0”, a state of blinking while displaying “1”, a state of blinking while displaying “2” and a state of blinking while displaying “3”.
When, in step S 91 , a long pushing operation E 16 (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction, the buzzer 71 sounds once, the number (“0”, “1”, “2” or “3”) then displayed on the speed indicator 64 is set as the second predetermined deceleration number of speeds, and the speed indicator 64 becomes a continuously lit state (step S 92 ). In this case, when “0” is set as the second predetermined deceleration number of speeds, the second automatic deceleration control will not be performed.
[13]
The first half of changing of the automatic shifting range R of the load mode (or run mode) described in sections [7], [8] and [9] hereinbefore will be described next with reference to FIG. 11 (the width of the automatic shifting range R of the load mode (or run mode) described in section [12] above being maintained).
When, with the setting switch 68 pushed to the load mode position (or run mode position) and the shift lever 28 operated to the neutral position N (step S 101 ), the up-shift button 61 is pushed (step S 102 ), the first and second main speed change devices 10 and 11 are operated for a next higher speed (step S 104 ). When the down-shift button 62 is pushed in the same state (step S 103 ), the first and second main speed change devices 10 and 11 are operated to a next lower speed (step S 105 ). In this case, operations as in steps S 13 , S 14 , S 16 , S 17 and S 19 in FIG. 5 are not performed, One of the first to fourth speed clutches 21 - 24 providing the current speed position of the first and second main speed change devices 10 and 11 is immediately disengaged, and a different one of the first to fourth speed clutches 21 - 24 is immediately engaged to provide a next higher speed (or a next lower speed) position of the first and second main speed change devices 10 and 11 .
When the first and second main speed change devices 10 and 11 are operated for a next higher speed (or a next lower speed) as described above, the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is set as the high speed limit position RH in the automatic shifting range R of the load mode (or run mode) (step S 106 ). The shift position of the first and second main speed change devices 10 and 11 (the high speed limit position RH in the automatic shifting range R of the load mode (or run mode)) is displayed on the speed indicator 64 (step S 107 ), and the speed indicator 64 is lit (step S 108 ).
When the high speed limit position RH in the automatic shifting range R of the load mode (or run mode) has been set, the low speed limit position RL in the automatic shifting range R of the load mode (or run mode) is set next based on the width of the automatic shifting range R of the load mode (or run mode) as described in section [12] hereinbefore (step S 109 ). When, for example, the fourth speed position is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode), and the width of the automatic shifting range R of the load mode (or run mode) is three stages, the second speed position is set as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode). In this case, where the low speed limit position RL of the automatic shifting range R of the load mode (or run mode) becomes lower than the first speed position (step S 110 ), the first speed position is set as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode) (step S 111 ).
[14]
The second half of changing of the automatic shifting range R of the load mode (or run mode) described in sections [7], [8] and [9] hereinbefore will be described next with reference to FIGS. 11 and 12 (the width of the automatic shifting range R of the load mode (or run mode) described in section [12] above being maintained).
When, with the setting switch 68 pushed to the load mode position (or run mode position) and the shift lever 28 operated to the low speed position L or high speed position H (step S 101 ), the up-shift button 61 is pushed (step S 121 ), steps S 13 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next higher speed (step S 123 ), overriding the states described in sections [7], [8] and [9] hereinbefore (the states of the first and second main speed change devices 10 and 11 being operated to the low speed side and high speed side in the automatic shifting range R of the load mode (or run mode)).
When the down-shift button 62 is pushed in the same state (step S 122 ), steps S 14 , S 16 , S 17 and S 19 in FIG. 5 are executed to operate the first and second main speed change devices 10 and 11 for a next lower speed (step S 127 ), overriding the states described in sections [7], [8] and [9] hereinbefore (the states of the first and second main speed change devices 10 and 11 being operated to the low speed side and high speed side in the automatic shifting range R of the load mode (or run mode)).
When the up-shift button 61 and down-shift button 62 are pushed, the shift positions of the first and second main speed change devices 10 and 11 are displayed on the speed indicator 64 (step S 131 ). When the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is the high speed limit position RH in the automatic shifting range R of the load mode (or run mode), the speed indicator 64 is lit (steps S 132 and S 133 ). When the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is not the high speed limit position RH in the automatic shifting range R of the load mode (or run mode), the speed indicator 64 is blinked (steps S 132 and S 134 ).
When, with the shift position of the first and second main speed change devices 10 and 11 being the high speed limit position RH in the automatic shifting range R of the load mode (or run mode), the up-shift button 61 is pushed to operate the first and second main speed change devices 10 and 11 are operated to a next higher speed, the shift position of the first and second main speed change devices 10 and 11 will deviate to the high speed side from the automatic shifting range R of the load mode (or run mode). In such a state (steps S 121 , S 123 and S 124 ), the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is set as the high speed limit position RH in the automatic shifting range R of the load mode (or run mode) (step S 125 ).
Next, the low speed limit position RL in the automatic shifting range R of the load mode (or run mode) is set based on the width of the automatic shifting range R of the load mode (or run mode) as described in section [12] hereinbefore (step S 126 ). When, for example, the fourth speed position is set from the third speed position as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode), and the width of the automatic shifting range R of the load mode (or run mode) is three stages, the second speed position is set from the first speed position as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode) (which corresponds to the state where, with the first and second main speed change devices 10 and 11 in the high speed limit position in the automatic shifting range R of the load mode (or run mode), the first and second main speed change devices 10 and 11 are operated to the high speed side whereby the entire automatic shifting range R of the load mode (or run mode) is moved to the high speed side).
When, with the shift position of the first and second main speed change devices 10 and 11 being the low speed limit position RL in the automatic shifting range R of the load mode (or run mode), the down-shift button 61 is pushed to operate the first and second main speed change devices 10 and 11 are operated to a next lower speed, the shift position of the first and second main speed change devices 10 and 11 will deviate to the low speed side from the automatic shifting range R of the load mode (or run mode). In such a state (steps S 122 , S 127 and S 128 ), the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is set as the low speed limit position RL in the automatic shifting range R of the load mode (or run mode) (step S 129 ).
Next, the high speed limit position RH in the automatic shifting range R of the load mode (or run mode) is set based on the width of the automatic shifting range R of the load mode (or run mode) as described in section [12] hereinbefore (step S 126 ). When, for example, the first speed position is set from the second speed position as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode), and the width of the automatic shifting range R of the load mode (or run mode) is three stages, the fourth speed position is set from the third speed position as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode) (which corresponds to the state where, with the first and second main speed change devices 10 and 11 in the low speed limit position in the automatic shifting range R of the load mode (or run mode), the first and second main speed change devices 10 and 11 are operated to the low speed side whereby the entire automatic shifting range R of the load mode (or run mode) is moved to the low speed side).
Next, the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is displayed on the speed indicator 64 (step S 131 ). When the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is the high speed limit position RH in the automatic shifting range R of the load mode (or run mode), the speed indicator 64 is lit (steps S 132 and S 133 ). When the shift position of the first and second main speed change devices 10 and 11 resulting from the operation is not the high speed limit position RH in the automatic shifting range R of the load mode (or run mode), the speed indicator 64 is blinked (steps S 132 and S 134 ).
First Modified Embodiment
As shown in preceding section [10] and FIG. 13 , when the sensitivity adjusting switch 76 is in the operation range H 4 , the second preset value N 12 is set to “0”. Instead, the second preset value N 12 (solid line A 5 ) in the operation range H 3 may be extended linearly to “0” (for example the left end of the operation range H 4 in FIG. 13 is “0”). With this modification, even when the sensitivity adjusting switch 76 is operated to the operation range H 4 , an “operation range to the high speed side” is set.
Second Modified Embodiment
Instead of setting the first and second preset values N 11 and N 12 with one sensitivity adjusting switch 76 as described in preceding section [10], a sensitivity adjusting switch 76 for exclusive use in setting and changing the first preset value N 11 may be provided along with a sensitivity adjusting switch 76 for exclusive use in setting and changing the second preset value N 12 . In this way, the first and second preset values N 11 and N 12 may be set and changed independently of each other.
Third Modified Embodiment
The auxiliary speed change device 12 shown in FIG. 1 may include, as does the second main speed change device 11 , a low-speed clutch (not shown) and a high-speed clutch (not shown) of the hydraulically operable multi-plate type arranged in parallel. Electromagnetic proportional valves (not shown) may be provided for the low-speed and high-speed clutches of the auxiliary speed change device 12 , respectively. With this construction, the first and second main speed change devices 10 and 11 and auxiliary speed change device 12 together provide first to 16th speeds. By pushing the up-shift button 61 and down-shift button 62 , the first and second main speed change devices 10 and 11 and auxiliary speed change device 12 may be shifted to the first to 16th speed positions.
Fourth Modified Embodiment
The first and second main speed change devices 10 and 11 shown in FIG. 1 are constructed as the hydraulic clutch type. The first and second main speed change devices 10 and 11 may be constructed, as is the auxiliary speed change device 12 , the speed change gear type with slidable shift elements (not shown). The shift elements may be slid by hydraulic cylinders (not shown).
This invention is applicable also to a work vehicle with first and second main speed change devices 10 and 11 providing ten speeds or six speeds, a work vehicle with auxiliary speed change device 12 shiftable to a high-speed position, an intermediate speed position and a low-speed position, and a work vehicle with first and second main speed change devices 10 and 11 constructed as stepless transmissions of the hydrostatic type of the belt type.
Fifth Modified Embodiment
Another modified embodiment will be described next with reference to FIG. 14 . The embodiment relates to a method of setting the width of the automatic shifting range R of the load mode (run mode) described in sections [7], [8] and [9] to two stages, three stages or four stages.
When, with the shift lever 28 placed in the neutral position N (step AS 81 ) and the setting switch 68 pushed to the load mode position, a long pushing operation (e.g. three seconds or longer) of the setting switch 68 is effected in D 2 direction ( FIG. 2 ) (step AS 82 ), a setting mode for the load mode is set (step AS 83 ), the buzzer 71 sounds once (step AS 84 ), and the speed indicator 64 blinks while displaying “L” indicating the setting mode for the load mode (step AS 85 ).
When, with the shift lever 28 placed in the neutral position N (step AS 81 ) and the setting switch 68 pushed to the run mode position, a long pushing operation (e.g. three seconds or longer) of the setting switch 68 is effected in D 1 direction ( FIG. 2 ) (step AS 82 ), a setting mode for the run mode is set (step AS 86 ), the buzzer 71 sounds once (step AS 87 ), and the speed indicator 64 blinks while displaying “d” indicating the setting mode for the run mode (step AS 88 ).
When the up-shift button 61 is pushed in the setting mode for the load mode or in the setting mode for the run mode as described above (step AS 89 ), the width of the automatic shifting range R is increased by one stage (e.g. from two stages to three stages) (step AS 91 ). The new width of the automatic shifting range R is displayed on the speed indicator 64 (“2”, “3” or “4”), and the speed indicator 64 blinks (step AS 93 ). When the down-shift button 62 is pushed (step AS 90 ), the width of the automatic shifting range R of the load mode (or run mode) is decreased by one stage (e.g. from three stages to two stages) (step AS 92 ). The new width of the automatic shifting range R of the load mode (or run mode) is displayed on the speed indicator 64 (“2”, “3” or “4”), and the speed indicator 64 blinks (step AS 93 ).
After a desired width of the automatic shifting range R of the load mode (or run mode) is obtained by pushing the up-shift button 61 and down-shift button 62 , the setting switch 68 pushed to the load mode position is further pushed long (e.g. three seconds or longer) in the D 2 direction (see FIG. 2 ) (or the setting switch 68 pushed to the run mode position is further pushed long (e.g. three seconds or longer) in the D 1 direction (see FIG. 2 )) (step AS 94 ).
As a result, the width of the automatic shifting range R of the load mode (or run mode) is set (step AS 95 ). The speed indicator 64 is lit, displaying the set width of the automatic shifting range R of the load mode (or run mode) (“2”, “3” or “4”) (step AS 96 ). The buzzer 71 is sounded once (step AS 97 ), to complete the setting mode for the load mode and the setting mode for the run mode. In this way, the width of the automatic shifting range R of the load mode (or run mode) may be set.
Sixth Modified Embodiment
The speed indicator 64 , instead of being the seven-segment type, may be the liquid crystal type including, as shown in FIG. 15(A) , eight indicating elements 64 a, 64 b, 64 c, 64 d, 64 e, 64 f, 64 g and 64 h corresponding to the first to eighth speed positions.
In this case, the state described in section [13] (i.e. the up-shift button 61 and down-shift button 62 are pushed in the state that the setting switch 68 is pushed to the load mode position (or run mode position, and the shift lever 28 is operated to the neutral position N) is indicated by the speed indicator 64 as shown in FIGS. 15(A) and (B).
As shown in FIG. 15(A) , for example, the first and second main speed change devices 10 and 11 are operated to the fifth speed position, and the fifth speed position of the first and second main speed change devices 10 and 11 is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode). When the width of the automatic shifting range R of the load mode (or run mode) has three stages, the third speed position of the first and second main speed change devices 10 and 11 is the low speed limit position RL of the automatic shifting range R of the load mode (or run mode). Thus, the indicating elements 64 e, 64 d and 64 c of the speed indicator 64 corresponding to the fifth, fourth and third speed positions are surrounded by a different color as the automatic shifting range R of the load mode (or run mode). The indicating element 64 e of the speed indicator 64 corresponding to the fifth speed position is lit. The other indicating elements 64 a - 64 d and 64 f - 64 h of the speed indicator 64 are off.
When the down-shift button 62 is pushed and the first and second main speed change devices 10 and 11 are operated to the fourth speed position, as shown in FIG. 15(B) , the fourth speed position of the first and second main speed change devices 10 and 11 is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode). The second speed position of the first and second main speed change devices 10 and 11 becomes the low speed limit position RL of the automatic shifting range R of the load mode (or run mode). Thus, the indicating elements 64 d, 64 c and 64 b of the speed indicator 64 corresponding to the fourth, third and second speed positions are surrounded by the different color as the automatic shifting range R of the load mode (or run mode). The indicating element 64 d of the speed indicator 64 corresponding to the fourth speed position is lit. The other indicating elements 64 a - 64 c and 64 e - 64 h of the speed indicator 64 are off.
Seventh Modified Embodiment
Where the speed indicator 64 is the liquid crystal type including, as shown in FIG. 16(A) , eight indicating elements 64 a, 64 b, 64 c, 64 d, 64 e, 64 f, 64 g and 64 h corresponding to the first to eighth speed positions, the state described in section [14] (i.e. the up-shift button 61 and down-shift button 62 are pushed in the state that the setting switch 68 is pushed to the load mode position (or run mode position, and the shift lever 28 is operated to the low speed position L or high speed position H) is indicated by the speed indicator 64 as shown in FIGS. 16(A) , (B), (C), (D) and (E).
As shown in FIG. 16(A) , for example, the first and second main speed change devices 10 and 11 are operated to the fifth speed position, and the fifth speed position of the first and second main speed change devices 10 and 11 is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode). When the width of the automatic shifting range R of the load mode (or run mode) has three stages, the third speed position of the first and second main speed change devices 10 and 11 is the low speed limit position RL of the automatic shifting range R of the load mode (or run mode). Thus, the indicating elements 64 e, 64 d and 64 c of the speed indicator 64 corresponding to the fifth, fourth and third speed positions are surrounded by the different color as the automatic shifting range R of the load mode (or run mode). The indicating element 64 e of the speed indicator 64 corresponding to the fifth speed position is lit. The other indicating elements 64 a - 64 d and 64 f - 64 h of the speed indicator 64 are off.
When the down-shift button 62 is pushed and the first and second main speed change devices 10 and 11 are operated to the fourth speed position, as shown in FIG. 16(B) , the high speed limit position RH (fifth speed position), and low speed limit position RL (third speed position) in the automatic shifting range R of the load mode (or run mode), and the automatic shifting range R of the load mode (or run mode) remain as they are, the indicating element 64 d of the speed indicator 64 corresponding to the fourth speed position blinks, and the other indicating elements 64 a - 64 c and 64 e - 64 h of the speed indicator 64 are off. Further, when the down-shift button 62 is pushed and the first and second main speed change devices 10 and 11 are operated to the third speed position, as shown in FIG. 16(C) , the indicating element 64 c of the speed indicator 64 corresponding to the third speed position blinks, and the other indicating elements 64 a, 64 b and 64 d - 64 h of the speed indicator 64 are off.
When, as shown in FIG. 16(C) , the shift position of the first and second main speed change devices 10 and 11 is the low speed limit position RL (third speed position) of the automatic shifting range R of the load mode (or run mode), and when the down-shift button 62 is pushed and the first and second main speed change devices 10 and 11 are operated to the second speed position, as shown in FIG. 16(D) , the second speed position of the first and second main speed change devices 10 and 11 is set as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode), and the fourth speed position of the first and second main speed change devices 10 and 11 is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode). The indicating elements 64 d, 64 c and 64 b of the speed indicator 64 corresponding to the fourth, third and second speed position are surrounded by the different color as the automatic shifting range R of the load mode (or run mode). The indicating element 64 b of the speed indicator 64 corresponding to the second speed position blinks, and the other indicating elements 64 a, 64 c - 64 h of the speed indicator 64 are off.
When, as shown in FIG. 16(A) , the shift position of the first and second main speed change devices 10 and 11 is the high speed limit position RH (fifth speed position) of the automatic shifting range R of the load mode (or run mode), and when the up-shift button 62 is pushed and the first and second main speed change devices 10 and 11 are operated to the sixth speed position, as shown in FIG. 16 (E), the sixth speed position of the first and second main speed change devices 10 and 11 is set as the high speed limit position RH of the automatic shifting range R of the load mode (or run mode), and the fourth speed position of the first and second main speed change devices 10 and 11 is set as the low speed limit position RL of the automatic shifting range R of the load mode (or run mode). The indicating elements 64 f, 64 e and 64 d of the speed indicator 64 corresponding to the sixth, fifth and fourth speed position are surrounded by the different color as the automatic shifting range R of the load mode (or run mode). The indicating element 64 f of the speed indicator 64 corresponding to the sixth speed position blinks, and the other indicating elements 64 a - 64 e, 64 g and 64 h of the speed indicator 64 are off.
|
A work vehicle with a speed change device, comprises, a plurality of wheels including at least one driven wheel; an engine for driving the driven wheel; a speed change device provided between the driven wheel and the engine; and automatic shifting mechanism. The automatic shifting mechanism is capable of operating the speed change device to a lower speed position within an automatic shifting range having a predetermined range and is capable of operating the speed change device up to a speed position which the speed change device was in before an operation to the lower speed position was effected, in response to load on the engine. The entirety of the automatic shifting range is changeable to a low speed side and to a high speed side, or the automatic shifting range can be widened to include more speed positions and narrowed to include less speed positions.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention, involving a novel microorganism belonging to the species Bacillus pumilus, relates to a novel microorganism, and to its secretory products and plasmids employing them, having an activity that prompts the secretion of gastric juice, countering gastric-acid decrease due to chronic gastritis.
[0003] 2. Description of the Related Art
[0004] For gastric ulcers, duodenal ulcers, and other peptic ulcers, drugs (such as gastric-acid secretion blockers, and gastric antacids) that suppress digestive fluids and other visceral-wall invasive factors, and drugs (such as mucoprotective agents) that reinforce defense mechanisms have been used. Nevertheless, although promoting gastric-acid secretion presumably should be effective in patients with chronic gastritis, particularly atrophic gastritis, the present situation is that gastric-juice promoters that are nontoxic to living organisms have not been developed.
[0005] In cases of Helicobacter pylori infection, which is one of the causes of gastric ulcers, chronic gastritis is engendered, ultimately ending in inducing ulcers and cancer. That is, the bacteria is deleterious to the gastric condition; yet the reality is that a microorganism that improves the gastric condition while being a kindred microbe has yet to be discovered.
[0006] Accordingly, the discovery of a gastric-health meliorating microorganism antagonistic to H. pylori has been desired. Meanwhile, the manufacture of therapeutic agents utilizing discovered novel microorganisms and their secretory products has been an issue.
BRIEF SUMMARY OF THE INVENTION
[0007] According to experiments by the inventors, for an environment that is totally the opposite of H. pylori, that is, to counter chronic gastritis—particularly, the type of chronic gastritis in which gastric acid decreases—a novel microorganism of the present invention promotes gastric juice secretion to alleviate the chronic gastritis, and moreover is hypothesized to prevent cancer and ulcers from chronic gastritis. Thus, the novel microorganism can be detected from stomach and blood of all persons, and can also be detected from the blood of patients with chronic gastritis, ulcers, or cancer.
[0008] Not only does it have properties advantageous to promoting gastric-juice secretion, but because it also exhibits platelet-, erythrocyte-, and leukocyte-increasing action, it enables multifarious applications.
[0009] As a result of animal experiments, effectiveness in promoting gastric juice secretion was confirmed in a novel microorganism (International Deposit Number: NITE BP-295) belonging to the species Bacillus pumilus; moreover, it proved to be nontoxic because its LD 50 is 2 g or more.
[0010] This microorganism can be both punctuate and catenulate in form, is 0.5 to 1 μm×10 to 20 μm in size with a flagellum on either end, and has motility, making figure-eight movements. It has spores, and is a highly aerobic gram-positive bacillus and coccus. It takes on a catenulate form. The isolation source is the human stomach wall or blood. Alternatively, a virus giving rise to chronic gastritis may be implanted in a fertilized ovum and the antagonizing microbes that appear may be collected.
[0011] The cultivation conditions are as below.
[0000] Per 1000 ml medium, (trypto-soya broth) are added the nutrients
[0012] peptone—17 g,
[0013] soybean peptone—3 g,
[0014] sodium chloride—5 g,
[0015] glucose—2.5 g, and
[0016] potassium hydrogenphosphate—2.5 g,
[0000] and 3 g caustic soda is added in. The pH is adjusted to 8.5. Nutrient medium sterilization conditions: 121° C., perform 15 minutes; cultivation temperature: 37° C.; cultivation period: from 2 to 7 days.
[0017] The bacteria cultivated under the above conditions are characterized by being obligatory-aerobic; viability confirmation is by unaided visual observation or by observation under a microscope.
[0018] Storage conditions: possible by generally employed methods, including freeze drying.
[0019] The novel microorganism thus collected has the following characteristics. It should be noted that they are principally by microscopic observation.
1. When it phagocytoses pathogens, antibacterial properties intensify. 2. Changes form depending on the pathogenic bacterium. 3. Secretory substances that are metabolites are brown. 4. Does not invade erythrocytes. (As to erythrocytes: When ordinary anticancer drugs are employed, the red blood cell count will not decrease—with the Hb remaining 12 to 16, the red blood cell count does not decrease; with hepatitis C, it goes to about 6.) 5. The novel microorganism cleanses dead tissue. 6. The novel microorganism is susceptible to radioactive beams, ultraviolet rays, and microacoustic waves. 7. The novel microorganism is highly heat-resistant—can withstand 100° C. for several hours, and does not lyse. Survives autoclaving. 8. Prompts increase in erythrocytes, platelets, and leukocytes; remedying of anemia is seen.
(From the fact that in a patient whose leukocyte was 6000, a white-blood-cell count of over 500 was verified even after being administered an anticancer drug, the augmenting action owing to this bacterium was verified. From the fact that in a patient whose platelet was 200,000, it fell only to the 3,000 level even after the patient was administered an anticancer drug, the augmenting action owing to this bacterium was verified.)
[0029] Its sequence: Partial sequencing was carried out; proved to have the genetic sequence represented by Seq. No. 1. Furthermore, as illustrated in FIGS. 2 through 4 , the microorganism was determined to be, with 99% homology, the species Bacillus pumilus. The phylogenetic tree is as in FIG. 5 . With the sequence having been partially specified, application to, for example, plasmid expression vectors and other practical uses are possible, and in large-scale culturing, screening, and drug manufacture numerous benefits are anticipated.
[0030] A method of extracting the secretory products is as follows. First, bacteria are cultivated in broth at a temperature of 33 to 37° C. for seven days. Next, pure butyl alcohol, in the same amount as, is added is stirred well into the culture filtrate. After leaving the mixture for three hours, or centrifuging it, the clear butyl alcohol liquid is separated off. Decinormal hydrochloric acid is added to the liquid to bring the pH to 3.0, and the mixture is stirred thoroughly and left for 12 hours. The mixture is then vacuum-dried to obtain bright yellow crystals, and organic and inorganic substances.
[0031] The solution apart from the butyl alcohol liquid is mixed in with active carbon, stirred well, and left for one day.
[0032] Active carbon alone is added to butyl alcohol, and after 12 hours the butyl alcohol eluate is subjected to vacuum drying. Thereafter repeating likewise, crystal is obtained.
[0033] The present invention also relates to a method of manufacturing secretory products from the present invention, utilizing a phenotypically transformed microorganism incorporating an expression vector having a DNA sequence such as will code the amino-acid sequence of the secretory product. A phenotypically transformed microorganism according to the present invention is cultivated in the manner described above, and the secretory product is isolated from the nutrient medium.
[0034] The novel microorganism of the present invention and its secretory products have activity prompting secretion of gastric acid, and are heat-resistant. The extract is hypothesized to counter chronic gastritis of the type in which gastric acid decreases, and other chronic gastritis, by promoting gastric acid secretion to alleviate the chronic gastritis, and, by regulating the stomach condition, in turn to prevent cancer and ulcers from the chronic gastritis. The bacterium is detected from the stomach and blood of all persons, and occasionally from the blood of patients with chronic gastritis, ulcers, or cancer.
[0035] Not only does it have properties advantageous to promoting gastric-juice secretion, but because it also exhibits platelet-, erythrocyte-, and leukocyte-increasing action, and moreover is nontoxic, it enables multifarious applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0036] FIG. 1 is a homology search explanatory diagram.
[0037] FIG. 2 is a diagram presenting homology search results (bases 1-60).
[0038] FIG. 3 is a diagram presenting homology search results (bases 61-840).
[0039] FIG. 4 is a diagram presenting homology search results (bases 841-1480).
[0040] FIG. 5 is a diagram presenting a phylogenetic tree of a novel microorganism of the present invention.
[0041] FIG. 6 is a diagram presenting a nutrient-medium colony of the novel microorganism of the present invention.
[0042] FIG. 7 is an enlarged view of FIG. 6 .
[0043] FIG. 8 is a diagram presenting a Gram-stain of a large colony.
[0044] FIG. 9 is a diagram presenting a Gram-stain of a small colony.
[0045] FIG. 10 is a diagram representing an individual identifying method in which pigment is applied to mouse fur.
DETAILED DESCRIPTION OF THE INVENTION
[0046] The present invention becomes apparent from typical embodiments cited in the following examples, but the present invention is not limited to the scope of the examples.
[0047] In the embodiments of the present invention, Embodiment 1 first represents cultivation conditions and results, and Embodiment 2 next describes how to separate secretory product off, and animal experiment employing the secretory product. Furthermore, antitumor test (Embodiment 3), toxicity test (Embodiment 4), clinical test (Embodiment 5), staining test (Embodiment 6) are explained.
First Embodiment
[0048] This microorganism is punctuate or catenulate in shape and 0.5 to 1 μm×10 to 20 μm in size with flagella on its both ends, and has motility to perform figure-eight movement. Although the microorganism is aerobic gram-positive bacillus or coccus with spores, it also takes on catenulate shape. The isolation source is the human stomach wall or blood. The cultivation conditions are as below. Per 1000 ml medium, (trypto-soya broth) are added the nutrients
[0049] peptone—17 g,
[0050] soybean peptone—3 g,
[0051] sodium chloride—5 g,
[0052] glucose—2.5 g, and
[0053] potassium hydrogenphosphate—2.5 g,
[0000] and 3 g caustic soda is added in. The pH is adjusted to 8.5. Nutrient medium sterilization conditions: 121° C., perform 15 minutes; cultivation temperature: 37° C.; cultivation period: from 2 to 7 days. ( FIGS. 6 , 7 , 8 and 9 .)
[0054] The bacteria cultivated under the above conditions are characterized by being obligatory-aerobic; viability confirmation is by unaided visual observation or by observation under a microscope. FIG. 6 presents an image of colonies cultivated for one day in the designated medium.
[0055] Furthermore, that of the colonies which is boxed in a square on the right is the colony whose surface is greatly rough, and that of the colonies which is boxed in a rectangular on the left is the small colony whose surface is smooth. FIG. 7 is an enlarged part of the colonies. Results of Gram-staining demonstrate that the right side colony is gram-positive bacillus ( FIG. 8 ), and the left side colony is gram-positive coccus ( FIG. 9 ). As to the conditions under which the bacteria are stored, they can be stored in ways generally employed, including freeze dehydration.
Second Embodiment
[0056] As to a change in animal gastric juice, a reaction to secretion-product doses was checked.
How Secretion Product Extracted
[0057] The secretory product was extracted in the following manner: The colonies were put in an incubator with temperature of 37° C., and when the surfaces of the colonies became right gray or right yellow surfaces after two to seven days, the colonies were put in broth to cultivate bacteria for seven days at a temperature of 30° C. to 37° C.
[0058] Next, into the culture filtrate, the same amount of pure butyl alcohol as the culture filtrate was stirred.
[0059] After the culture filtrate into which the butyl alcohol had been stirred was left for three hours, or was centrifuged, clear butyl alcohol solution was separated off.
[0060] The butyl alcohol solution was added with decinomal hydrochloric acid to bring pH to 3.0, stirred thoroughly, and left for 12 hours. Subsequently, the solution was vacuum-dried to obtain right yellow crystal, organic and inorganic substances.
[0061] A solution other than butyl alcohol solution and active carbon was mixed, stirred thoroughly, and left for one day.
[0062] Only active carbon was added to butyl alcohol, and after 12 hours, butyl alcohol eluate was subjected to vacuum-dry. Afterwards, such procedures were repeated to obtain crystal.
Animal Experiment
[0063] In Embodiment 2 of the present invention, as to the product secreted by the novel microorganism, a test for measuring the amount of gastric juice secretion in Heidenhain pouch dogs was carried out.
[0064] Experimental: As medium, carbohydrate solution was used in the proportion of 5% to the secretory product of 2.6 g (and was stored at room temperatures).
Experimental animal: male dogs purchased at the age of 13 months were for 13 days medically inspected, acclimated, and bread. By observing their normal conditions, and by measuring their weights, whether or not the dogs are healthy animals was checked to use 13 month-old animals whose weights on the day of surgery was from 14.2 to 14.7 kg. Environment: The experimental environment was arranged in the range in which a temperature was from 20 to 28° C., a relative humidity was from 30 to 80%, the times of ventilation was from 12 to 18 times per hour, lighting hours were 2 hours (from 7:00 to 19:00). Feed: Labo D Stock® (Nosan Corporation) Drinking water: Water was taken freely from an automatic feed device in a water supply and sewerage system. Administration Method: The secretory product of 500 mg was put in a mortar, and then the carbohydrate solution in the proportion of 5% was put in the mortar to dissolve the secretory product with a pestle. The carbohydrate solution was added to the dissolved secretory product so as to be 50 ml, and was rendered a dosing solution. Dosing solution weight: 10 mg/kg Dosing solution volume: 1 mL/kg, three examples Measurement Method: The amount of secreted gastric acid was measured every 15 minutes within 2 hours after the dosing solution was administered, and changes in the secreted gastric acid amount were studied.
Heidenhain Pouch Dog Preparation and Management
[0073] The dogs were given nothing to eat for 18 hours or more as of the day before the surgery, and atropine hydrosulfate (0.1 mg/kg) was intramuscularly administered in the dogs 30 minutes before anesthesia induction. Sodium thiopental was given to the dogs from their forelimb cephalic veins to induce anesthesia, and then the dogs were laid on the back on a moisturizing pad of a body temperature controller, with the pad temperature being arranged to be 38° C. on a surgical bed. The dogs' tracheae were then cannulated and they were given artificial respiration and an inhalant anesthetic. The artificial-respiration single inhale/exhale volume was made 20 to 25 mg/kg, at 11 to 13 cylces/min. The inhalant anesthetic was introduced with an added 1 to 4% having been nitrous-oxide gasified, and maintenance anesthesia at 0.5 to 2.0% was carried out. After the hair on and around the dogs' abdominal region was removed with an electric clipper, the entire operating area was sterilized and an incision was made through the skin and muscle layers along a medial line from slightly below the xiphisternum to above the navel region, and then the stomachs were withdrawn from the abdominal cavities to expose the stomachs on the abdominal walls. The blood vessels in the greater curvature of the stomach intersecting with an excision marking line were double-ligated, and cut. After that, the excision marking line was cut and sutured with a gastrointestinal suturing instrument and a gastrostomy tube was set alongside the pouches, and then the opened abdominal region was sutured and the pouch interior was washed several times with a warmed physiological saline solution. The dogs were given nothing to eat within two days from the day after the surgery. During the food deprivation, the dogs received fluid of 150 mL/day (Lactec D®, Otuka Pharmaceutical Co., Ltd). After the food deprivation, the dogs were bred as usual, and in order to prevent dehydration, dietary salt (approx. 0.4 g/day) was mixed into feed, and given to the dogs.
Gastric Juice Secretion Measurement Method
[0074] The Heidenhain pouch dogs were used three weeks after the surgery. The dogs were deprived of feed for 18 hours or more in the situation in which water was given, and their gastric juice was collected with the dogs being hung with an abdominal bandage in a steel pipe frame. The gastric juice was collected every 15 minutes from 30 minutes before, to two hours after, secretory product administration, and the gastric juice volume (mL) and acidity (value measured by neutralizing titration technique with 0.01 N NaOH: mEq/L) were measured to calculate from the obtained gastric juice volume and acidity the secreted gastric juice amount (mEq/15 min) at each measuring time.
[0075] The results are set forth in Tables 1 through 4.
[0000]
TABLE 1
Change of secreted gastric juice amount by administrating
(test substance) A
Secretion
secreted gastric juice amount (mEq/15 min)
Experimental
amount
before
Inspection time after administration (min)
Group
(mg/kg)
n = 3
administration
15
30
45
60
75
90
105
120
Secretion
10
Average
0.82
0.97
0.96
1.18
1.20*
0.95
0.77
0.88*
0.72
(testsubstance) A
standard
0.09
0.12
0.16
0.19
0.12
0.16
0.04
0.08
0.05
deviation
*P < 0.05; Significant difference with respect to before administration rate (Paired t-test)
[0000]
TABLE 2
Change of secreted gastric juice amount by administrating secretion (test substance) A
secreted gastric juice amount (mEq/15 min)
Experimental
Individual
before
Inspection time after administration (min)
Group
number
administration
15
30
45
60
75
90
105
120
Secretion
1
0.75
0.80
0.90
1.20
1.00
0.65
0.72
0.80
0.64
(testsubstance) A
2
1.00
1.20
1.25
1.50
1.40
1.20
0.84
1.05
0.80
3
0.72
0.90
0.72
0.84
1.20
1.00
0.75
0.80
0.72
[0000]
TABLE 3
Change of secreted gastric juice amount by administrating secretion (test substance) A
secreted gastric juice amount (mEq/15 min)
Experimental
Secretion
before
Inspection time after administration (min)
Group
amount
n = 3
administration
15
30
45
60
75
90
105
120
meat extract
25%
Average
0.01
0.15
0.53
0.57
0.41
0.25
0.15
0.09
0.07
standard
0.0
0.1
0.1
0.0
0.0
0.1
0.0
0.0
0.0
deviation
[0000]
TABLE 4
Change of secreted gastric juice amount by administrating meat extract
secreted gastric juice amount (mEq/15 min)
Experimental
Individual
before
Inspection time after administration (min)
Group
number
administration
15
30
45
60
75
90
105
120
meat extract
1
0.02
0.27
0.55
0.52
0.42
0.31
0.19
0.12
0.12
2
0.02
0.16
0.61
0.57
0.32
0.31
0.20
0.11
0.07
3
0.00
0.02
0.42
0.61
0.48
0.14
0.07
0.03
0.02
[0076] Results of administering the secretory product demonstrated gastric juice secretion amounts of 0.82 to 1.20 on an average before, and within two hours of, the secretory product administration, and demonstrated the largest increase in gastric acid secretion amount 60 minutes after the secretory product administration. The increment was 0.38 mEq/15 min.
[0077] Experimental results on individual dogs 1, 2, and 3 are set forth in Table 2. The results demonstrated statistically significant increases in gastric juice secretion amount 60 minutes and 105 minutes after the secretory product administration, compared with the gastric juice secretion amount before the administration. On an average, gastric juice secretion amounts were of 0.01 to 0.57 before, and within two hours of, meet extract administration (Tables 3 and 4). The amount of gastric acid secretion increased most largely 45 minutes after the meet extraction administration, and the increment was 0.56 mEq/15 min.
[0078] In the secretory product of the present invention, above examples showed statistically significant differences in gastric acid secretion 60 minutes and 105 minutes after the secretory product administration, and also showed a tendency for the gastric acid secretion to increase even 15, 30, 45 and 75 minutes after the gastric acid secretion administration, even though there was no statistically significant difference. Compared with the results of administering meet extract, the secretory product (test substance) administration results demonstrated slightly smaller increment than that in the meet extract administration results, but demonstrated at the time at which the gastric acid secretion most largely increased, the gastric acid secretion increase and decrease similar to those in the meet extract administration results. From these results, it is believed that the secretory product (test substance) is effective in increasing gastric juice secretion amount, and this effect was the same with that of the meat extract.
Third Embodiment
[0079] In embodiment 3 of the present invention, in order to search effectiveness of the secretory product to Xenograft model, study of influence of the secretory product on tumor cell line MKN-45 was attempted. The secretory product as test substance was administered subcutaneously in experimental animals for four weeks. As end points, weight measurement, tumor volume measurement, hematological test, and pathological test were carried out.
Experimental Overview
[0080] 1. Experimental animal: Twenty animals 15.2 to 20.1 g in weigh—BALB/C-nu-type male mice purchased at the age of four weeks—were used. Through the experimental period, the animals were bred in an animal room arranged in a region in which a temperature was 20 to 26° C., a relative humidity was 40 to 70%, the times of ventilation was 10 to 20 times per hour, lighting hours were 12 hours.
[0081] 2. Breeding conditions: Water and feed are freely taken.
[0082] 3. Experimental groups: When tumors developed to have an average volume of 200 to 300 mm 3 , the animals were divided into two groups.
[0083] 4. Bulk powder of the product secreted by the novel microorganism was precisely weighed with a top-loading balance for highly precise analysis, and was dissolved into normal saline solution of 10 mL. All dosing solutions were prepared when used.
[0084] 5. Tumor cell preparation: Cell culture solution was prepared by adding to medium penicillin-streptomycin of 100 u/mL to 100 μmL.
[0085] Cells that had been frozen were thawed in warm water of approx. 37° C. to transfer the cells to a centrifuge tube containing the culture solution previously incubated at temperature of 37° C. After the culture solution in which the cells were transferred was centrifuged at 1000 rpm for five minutes, supernatant was cleared out, and the culture solution was added to the cells, and suspended thoroughly by pipetting. Subsequently, the suspension was moved into a culture flask to start culture in a CO 2 incubator (MCO-175 from Sanyo Electric Co., Ltd) in which temperature was arranged to be 37° C., and carbon dioxide concentration was arranged to be 5%. In subcultivating the cells, the culture solution was removed from the incubator before cell density increased excessively, and the surfaces of the cells were cleaned with PBS solution. After that, the cells were added with 0.25% trypsin and 1 m MEDTA solution, put in the CO 2 incubator, and completely separated off. The separated cells were collected with a proper amount of culture solution, and the cells and culture solution were centrifuged at 1000 rpm for 5 minutes. Then, supernatant was removed, and culture solution was added to the cells, and pipetted. After that, the cells were seeded in a different culture flask containing the culture solution. Subcultivation was carried out as frequently as two to four days, the cells subcultitvated two times or more were used for transplantation.
[0086] 6. Administration method: The test substances were subcutaneously administered dorsally in the mice once-daily for four weeks with a disposable syringe and a 27 G injection needle. The amount of dosing solution was calculated based on weights measured two times a week.
[0087] 7. Tumor cells: Tumor cells were subcutaneously administered dorsally in the mice with the disposable syringe and 27 G injection needle on the day of transplantation.
[0088] In the foregoing experiment, normal condition of the mice and whether or not the mice were living were checked once a day, and their weights were measured twice a week. Furthermore, the tumor longest diameter (A) and shortest diameter (B) were measured twice a week with a digital caliper. From the measured longest and shortest diameters, tumor volume was calculated using the following expression.
[0000] Tumor volume (mm 3 )= AB 2 /2
[0089] Furthermore, hematological test was carried out. As to blood EDTA-2K-trated after taken from abdominal great veins of all the mice, the following inspection items were measured with an automatic hematology analyzer (Sysmex corporation, E-4000). The results are set forth in Table 5.
[0000]
TABLE 5
Inspection Item
Measuring Method or Instrument
Unit/Sign
Red blood cell (RBC) count
Electrical-resistance detection
10 4 /μL
Hematocrit (Ht)
Maximum erythroid pulse detection
%
Hemoglobin (Hb) content
SLS hemoglobin method
g/dL
Platelet (Plt) count
Electrical-resistance detection
10 4 /μL
White blood cell (WBC) count
Eectrical-resistance detection
10 2 /μL
Mean red blood cell index
calculation method
Mean corpuscular volume (MCV)
Ht
(
%
)
RBC
(
10
4
/
μL
)
×
10
3
fL
Mean corpuscular hemoglobin (MCH)
Hb
(
g
/
dL
)
RBC
(
10
4
/
μL
)
×
10
3
pg
Mean corpuscular hemoglobin concentration (MCHC)
Hb
(
g
/
dL
)
Ht
(
%
)
)
×
10
2
%
[0090] Pathology test: After the blood drawing was completed, tumor tissues were extirpated to measure their weights, and then were fixed with a neutral buffered formalin solution. After the fixing, paraffin sections were prepared in accordance with a normal method, and then were subjected to hematoxylin-eosin staining. Subsequently, by carrying out immunohistochemical staining (TUNEL), positive cells in 1000 tumor cells were counted to calculate the ratio positive cells/tumor cells.
[0091] Twenty mice were used to subcutaneously transplant tumors dorsally in the mice. After the tumor transplantation, when the tumor developed to have an average volume of approx. 200 to 300 mm, the mice were divided into two groups so that the average tumor volume in one group equals to that in another. The test substances were administered subcutaneously in the mice continuously for four weeks. From the day of the test substance administration, normal condition of the mice, and whether or not the mice were living were observed once-daily for four weeks, and weights of the mice and sizes of the tumors were measured twice a week. Four weeks after the test substance administration, blood of the mice was taken from their abdominal great veins under ether anesthesia, and tumor tissues were extirpated.
[0092] The foregoing test results will be described in detail.
[0093] 1. Shifts in weight: Weight changes in the two groups for four weeks after the test substance administration were set forth in Tables 6 and 7. In both of the two groups: that of the groups in which normal saline solution was administered, and that of the groups in which the secretory product was administered, significant weight decreases were observed during the administration period. The peak of the weight decreases was on the twelfth day from the administration in the normal saline solution-administering group, and was on the second day from the administration in the secretory product-administering group. Compared with the weight on the first day from the administration, the normal saline solution-administering group experienced weight decrease of 1.9 g on the twelfth day, and the secretory product-administering group experienced weight decrease of 1.2 g on the second day.
[0000]
TABLE 6
Influence of repeated oral dosing of secretory product (test substance) A
for four weeks on weight in nude mouse antitumor test (MKN-45)
sample
Weight (g)
Dosage material
number
1
5
8
12
15
19
22
26
29 (day)
Normal saline
10
Average
18.1
17.2*
17.3
16.2**
16.3**
16.5**
16.3**
16.7**
17.4
solution
standard
0.4
0.4
0.4
0.4
0.5
0.4
0.4
0.5
0.5
deviation
Secretion
10
Average
19.3
19.2
19.1
18.6**
18.2**
18.2**
18.1**
18.6*
19.4
(testsubstance) A
standard
0.5
0.6
0.6
0.5
0.5
0.4
0.5
0.5
0.5
deviation
*, **p < 0.05, 0.01 Significant difference with respect to before administration rate (Paired t test)
[0000]
TABLE 7
Influence on four weeks repetition oral administration
of the secretion which gives it to the weight in the antitumor
examination of the nude mouse (MKN-45)
Dosage
Weight (g)
material
Animal No.
1
5
8
12
15
19
22
26
29 (day)
Normal saline
1
17.2
16.8
17.6
17.0
17.0
16.9
17.3
17.4
17.7
solution
2
17.8
16.3
16.0
14.9
14.9
15.1
14.5
15.0
15.9
3
18.7
18.6
18.6
17.4
18.0
18.0
17.8
18.8
19.2
4
18.0
16.4
16.6
15.6
15.6
15.7
15.6
16.4
17.7
5
17.6
17.0
17.5
16.6
16.9
17.1
16.6
16.2
18.0
6
17.7
16.4
16.2
15.1
15.1
15.7
15.8
16.2
16.8
7
19.5
18.7
19.3
17.8
18.1
18.5
18.0
18.7
19.0
8
16.9
18.3
17.9
16.0
15.9
16.8
16.5
16.8
17.2
9
18.7
16.5
16.3
15.6
15.6
15.9
15.3
15.6
16.0
10
18.5
17.4
17.2
15.9
15.8
15.7
15.7
16.0
16.5
Secretion
11
20.8
19.3
19.7
19.1
19.3
18.7
18.9
19.4
20.1
(testsubstance) A
12
17.7
17.6
17.3
16.7
16.5
16.8
16.3
17.3
17.9
13
16.5
15.9
16.0
15.9
15.4
15.8
15.5
15.5
16.7
14
21.3
20.9
20.7
20.2
19.5
19.1
18.7
18.5
18.8
15
19.6
19.8
19.7
19.6
19.0
18.9
18.8
19.7
20.0
16
19.6
19.6
19.1
18.7
18.0
18.4
17.8
18.4
19.4
17
18.9
19.3
19.2
18.3
18.1
18.3
18.3
19.1
20.6
18
18.5
18.5
18.7
18.0
17.5
17.5
17.7
18.2
19.2
19
21.0
22.3
22.2
20.9
20.4
20.4
20.6
21.3
22.2
20
19.1
18.4
18.5
18.3
18.2
18.3
18.2
18.1
19.3
[0094] 2. Tumor weight measurement: Tumor volume changes within four weeks of the test substance administration are set forth in Tables 8 to 9. The normal saline solution-administering group demonstrated day-by-day tumor volume increase during the solution administration period. Also in the secretory product-administering group, the similar tumor volume increase to that in the normal saline solution-administering group was observed. Both of the two groups experienced no significant tumor volume increase on each measurement date.
[0000]
TABLE 8
Influence of repeated oral dosing of secretory product (test substance) A
for four weeks on tumor volume in nude mouse antitumor test (MKN-45)
The number
tumor volume (mm 3 )
material
of the examples
1
5
8
12
15
19
22
26
29 (day)
Normal saline
10
Average
255.9
382.5
478.5
584.3
729.5
920.1
1094.6
1255.9
1479.9
solution
standard
21.9
22.9
23.3
33.8
42.8
55.2
66.9
76.0
89.8
deviation
Secretion
10
Average
223.7
350.3
433.8
575.5
703.9
884.8
1014.1
1189.6
1412.2
(test substance) A
standard
21.8
33.8
37.2
49.4
69.3
87.0
92.8
125.3
142.8
deviation
[0000]
TABLE 9
Influence of repeated oral dosing of secretory product (test substance) A
for four weeks on hematological inspection in nude mouse antitumor test (MKN-45)
Dosage
tumor volume (mm 3 )
material
Animal No.
1
5
8
12
15
19
22
26
29 (day)
Normal saline
1
290.1
578.0
760.8
940.8
1136.2
1403.6
1811.6
1963.5
2216.8
solution
2
292.5
366.7
539.6
602.8
761.3
873.3
1207.1
1488.2
1851.3
3
137.7
296.5
425.3
457.9
577.6
658.6
754.3
853.9
927.4
4
193.9
309.0
348.0
524.3
629.3
719.3
901.6
1111.6
1432.1
5
386.0
423.9
465.5
538.7
789.6
1074.6
1149.3
1362.9
1574.3
6
252.4
342.4
433.4
593.0
621.9
780.4
899.2
951.7
1081.3
7
234.5
371.2
465.7
543.3
685.6
875.5
1055.6
1204.0
1458.6
8
215.1
282.4
377.4
408.9
533.3
792.4
957.2
1099.0
1325.4
9
252.0
328.1
382.2
469.8
615.3
811.1
795.6
955.9
1207.3
10
305.2
527.3
586.8
763.1
945.3
1212.3
1414.5
1568.1
1724.7
(secretion test
11
305.8
396.1
471.0
684.1
879.3
1050.8
1228.1
1326.9
1526.7
substance) A
12
321.4
445.5
536.2
686.7
804.8
958.2
1094.0
1617.4
1779.9
13
256.0
379.5
405.0
450.6
540.7
821.5
915.1
990.9
1289.7
14
169.0
306.6
366.1
539.3
652.9
767.3
843.7
941.5
1158.6
15
113.4
136.1
186.4
252.5
288.8
385.6
489.1
635.1
788.2
16
245.0
436.4
564.1
766.4
993.7
1350.6
1453.8
1758.2
2002.8
17
134.5
256.0
489.8
530.5
551.4
773.3
943.2
993.6
1146.9
18
241.9
392.1
447.5
622.4
676.3
742.6
799.3
899.4
976.8
19
210.8
326.1
402.7
605.0
819.3
984.6
1196.1
1495.0
1898.7
20
239.1
428.5
469.3
617.2
831.7
1013.7
1178.6
1237.8
1553.7
[0095] 3. Hematological test: Results of hematological test in the two groups within four weeks of the test substance administration are set forth in Tables 10 and 11. The secretory product-administering group experienced a more significant increase in platelet count among inspection items, compared with the saline solution administering-group, but neither normal saline solution-administering group nor the secretion-administering group experienced any significant increase in other seven inspection items.
[0000]
TABLE 10
Influence of repeated oral dosing of secretory product (test substance) A for
four weeks on hematological inspection in nude mouse antitumor test (MKN-45)
Administered
No. of
RBC
Ht
Hb
MCV
MCH
MCHC
Plt
WBC
substance
Subjects
(10 4 /μL)
(%)
(g/dL)
(fL)
(pg)
(%)
(10 4 /μL)
(10 2 /μL)
Normal saline
10
Average
1046.6
46.7
15.5
44.7
14.8
33.1
76.0
16.8
solution
± standard
9.3
0.4
0.2
0.3
0.2
0.3
2.7
1.8
deviation
Secretion(test
10
Average
1040.6
45.6
14.9
43.9
14.3
32.7
94.0##
23.3
substance) A
± standard
12.5
0.5
0.2
0.3
0.2
0.4
2.8
3.8
deviation
RBC: red blood cell count,
Ht: hematocrit,
Hb: hemoglobin content,
MCV: mean corpuscular volume,
MCH: mean corpuscular hemoglobin,
MCHC: mean corpuscular hemoglobin concentration,
Plt: platelet count,
WBC: white blood cell count
#, ##p < 0.05, 0.01 significant difference with respect to normal saline solution (student t test)
[0000]
TABLE 11
Influence of repeated oral dosing of secretory product
(test substance) A for four weeks on hematological
inspection in nude mouse antitumor test (MKN-45)
Dosage
RBC
Ht
Hb
MCV
MCH
MCHC
Plt
WBC
material
Animal No.
(10 4 /μL)
(%)
(g/dL)
(fL)
(pg)
(%)
(10 4 /μL)
(10 2 /μL)
Normal saline
1
1030
46.7
15.3
45.3
14.9
32.8
88.0
23
solution
2
1051
46.1
15.6
43.9
14.8
33.8
59.5
19
3
1012
46.0
14.9
45.5
14.7
32.4
73.0
12
4
1019
44.5
14.6
43.7
14.3
32.8
77.8
10
5
1078
47.6
15.6
44.2
14.5
32.8
82.1
21
6
1030
45.4
14.7
44.1
14.3
32.4
71.3
10
7
1101
48.4
15.7
44.0
14.3
32.4
82.4
11
8
1044
48.4
17.0
46.4
16.3
35.1
69.4
15
9
1026
45.8
15.7
44.6
15.3
34.3
72.1
23
10
1075
48.3
15.5
44.9
14.4
32.1
84.0
24
Secretion
11
1061
46.0
14.0
43.4
13.2
30.4
90.7
19
(test substance) A
12
991
44.6
14.9
45.0
15.0
33.4
89.5
53
13
1021
46.5
14.9
45.5
14.6
32.0
94.1
23
14
1118
48.0
15.6
42.9
14.0
32.5
90.6
15
15
998
44.7
14.3
44.8
14.3
32.0
104.6
28
16
1053
45.3
15.1
43.0
14.3
33.3
100.0
22
17
1001
43.3
14.3
43.3
14.3
33.0
109.1
10
18
1074
47.7
15.5
44.4
14.4
32.5
94.1
28
19
1049
45.1
15.9
43.0
15.2
35.3
89.6
12
20
1040
45.1
14.7
43.4
14.1
32.6
77.9
23
RBC: red blood cell count,
Ht: hematocrit,
Hb: hemoglobin,
MCV: mean corpuscular volume,
MCH: mean corpuscular hemoglobin,
MCHC: mean corpuscular hemoglobin concentration,
Plt: platelet count,
WBC: white blood cell count
[0096] 4. Tumor weight measurement: Changes of tumor weight measured 4 weeks after the test substance administration are set forth in Tables 12 and 13. The tumor weights in the normal saline solution-administering and secretion-administering groups were respectively 0.093±0.109 g and 1.022±0.016 g, and neither of the two groups experienced significant tumor weight changes.
[0000]
TABLE 12
Influence of repeated oral dosing of secretory product
(test substance)A for four weeks on tumor weight in
nude mouse antitumor test (MKN-45)
Dosage material
sample No.
tumor weight (g)
Normal saline
10
Average ± standard
1.093 ± 0.109
solution
deviation
Secretion
10
Average ± standard
1.022 ± 0.016
(test substance)A
deviation
[0000]
TABLE 13
Influence of repeated oral dosing of secretory product
(test substance)A for four weeks on tumor weight in
nude mouse antitumor test(MKN-45)
Dosage
Animal
tumor
material
No.
weight (g)
Normal saline
1
1.665
solution
2
1.534
3
0.925
4
1.006
5
0.605
6
0.599
7
1.141
8
1.099
9
1.220
10
1.140
Secretion
11
1.174
(test substance) A
12
0.905
13
0.937
14
1.026
15
0.751
16
1.613
17
1.047
18
0.595
19
1.658
20
0.511
[0097] 5. Pathological test: Average values in the two groups in pathological test within four weeks of the test substance administration are set forth in Tables 14 and 15. Results of calculating the ratio positive cells/tumor cells in the normal saline solution-administering and secretion-administering groups demonstrated no numerical significant change.
[0000]
TABLE 14
Influence of repeated oral dosing of secretory product (test substance)A
for four weeks on illness physical examination in nude mouse antitumor test (MKN-45)
Dosage material
Normal saline
Secretion
solution
(test substance) A
parameter
number of sample
10
10
Histological grade
Grade
No therapeutic effects observed
0
10 (100.0) c
10 (100)
Degenerative changes in tumor cells, but no destruction of tumor nests
I
0
0
Destruction and disappearance of tumor nests, but viable cells remain
viable cells occupy large areas (≧⅓)
IIa
0
0
viable cells occupy small areas (<⅓)
IIb
0
0
Tumor cells remain but appear non-viable
III
0
0
No tumor cells remain
IV
0
0
TUNEL d index (% Average ± standard
1.17 ± 0.16
1.09 ± 0.08
deviation)
c Value in parenthesis indicates the % incidence
d TdT (terminal deoxynucleotidyl transferase) mediated dUTP-biotin Nick End Labeling
[0000]
TABLE 15
Influence of repeated oral dosing of secretory product (test substance) A
for four weeks on illness physical examination in nude mouse antitumor test (MKN-45)
Dosage material
Animal No.
Organs/tissues
Findings
Histological grade
TUNEL index (%)
Normal saline
1
Tumor
No therapeutic effects observed
0
1.6
solution
2
Tumor
No therapeutic effects observed
1.2
3
Tumor
No therapeutic effects observed
0
0.7
4
Tumor
No therapeutic effects observed
0
1.2
5
Tumor
No therapeutic effects observed
0
2.4
6
Tumor
No therapeutic effects observed
0
0.9
7
Tumor
No therapeutic effects observed
0
1.3
8
Tumor
No therapeutic effects observed
0
0.8
9
Tumor
No therapeutic effects observed
0
0.9
10
Tumor
No therapeutic effects observed
0
0.7
Average
1.17
standard
0.16
deviation
Secretion
11
Tumor
No therapeutic effects observed
0
0.9
(test substance) A
12
Tumor
No therapeutic effects observed
0
1.3
13
Tumor
No therapeutic effects observed
0
1.0
14
Tumor
No therapeutic effects observed
0
0.8
15
Tumor
No therapeutic effects observed
0
0.9
16
Tumor
No therapeutic effects observed
0
1.5
17
Tumor
No therapeutic effects observed
0
1.2
18
Tumor
No therapeutic effects observed
0
1.3
19
Tumor
No therapeutic effects observed
0
1.2
20
Tumor
No therapeutic effects observed
0
0.8
Average
1.09
standard
0.08
deviation
[0098] In both of the normal saline solution-administering and secretory product-administering groups, as to weight during the administration period, above results demonstrated weight decrease until the second or third day from the administration, but showed a tendency of regaining the weight on the first day of the administration after the second or third day from the administration. Such a weight decrease is believed to occur under the influence of the tumor transplantation, not of the test substance, because the normal saline solution-administering group also experiences the weight decrease. As to tumor volume, in the normal saline solution-administering and secretory product-administering groups, a tumor volume increase similar to the tumor weight increase was observed during the administration period, and a tumor volume decrease caused by secretory product administration was not demonstrated. In the hematological test, the secretory product-administering group experienced a significant increase in platelet count. These results made it clear that the secretory product of the present invention dose not have activity increasing tumor cells. Accordingly, it is apparent that the secretory product of the present invention can be safely given even to patients with stomach cancer and other tumors in digestive system in order to increase gastric juice of the patients.
[0099] In addition, although the weight decrease was demonstrated until the second or third day from the administration, no significant change was experienced. Tumor weight measurement: Tumor weight changes in the two groups within four weeks of the test substance administration are set forth in Tables 8 and 9. The normal saline solution-administering group demonstrated a day-by-day tumor volume increase during the administration period. Also in the secretory product-administrating group, a similar tumor volume increase to that in the normal saline solution-administering group was observed. Neither of the two groups experienced any significant tumor volume increase.
Fourth Embodiment
[0100] Embodiment 4 (single subcutaneous dose toxicity test on mice with the product secreted by the novel microorganism) of the present invention will be described with FIG. 10 . In this test, a study was made as to lethal dose and toxicological appearance in the situation in which the product secreted by the novel microorganism was subcutaneously administered in the mice one time.
[0000] Secretory Product from Present-Invention Novel Microorganism Employed
1. Characteristics: brownish-yellow colored; acicular crystalline. 2. Solubility: Soluble in distilled water, and in 5% dextrose in water. 3. Stability: Stable because not hydrolyzable, air-oxidizing, photodegradable, or thermally degradable. At a pH of 8 or more, however, becomes clouded. 4. Storing conditions: Hermetically sealed (with a desiccant being included) at room temperature. 5. Storing location: Stored in a room-temperature cabinet.
Experimental Mice
[0106] 1. Species, genealogy, sex: mouse {Slc:ICR}, SPF animal, male
[0107] 2. Age in week: Mice that are four weeks old are grouped at the age of 5 weeks to start using the mice at the age of 6 weeks.
[0108] 3. Weights of the mice when they are grouped: 29.4 to 33.9 g
[0109] 4. Breeding environment conditions: A temperature is from 22.2 to 22.7° C.; a relative humidity is from 48.6 to 64.2%; RH•light-dark cycle is12 hours; the times of ventilation is 10 times per hour; and feed and drinking water are taken freely.
[0110] 5. Individual identification: In 5 animals in each of the administrating groups, fur of the mice illustrated in FIG. 10 was applied with pigment by employing saturated picric acid solution to perform individual identification.
[0111] 6. Dosing solution adjusting method: After the secretory product and solvent (distilled water) were weighed, they were gradually blended, crushed and made cloud, and then were rendered a predetermined amount of dosing solution.
[0112] 7. Dosing solution amount: the dosing solution weight and grouping as shown in Table 5 with 2000 mg/kg that was the upper limit in guideline for non-clinical trials for pharmaceuticals being defined as high dose, dosing solution weight was 1,000 mg/kg half of the high dose, and a control (comparative group) was arranged.
[0113] 8. Administration Method: Dosing solution was subcutaneously administered, and in both the administering groups, dosing solution of 20 mL/kg was administered. Each dosing solution calculated from weight right before the administration was administred subcutaneously in backs of necks of the mice with a syringe on which a 26 G needle was put. Administration period was determined to be only one time on the first day (Day 1), and the administration was carried out in the morning.
[0114] 9. Observation period: Observation period was determined to be until the fifteenth day with the day of administration as the first day. As to when observation was carried out, whether or not the mice were living and normal condition of the mice were observed right after the administration, 1, 2, 4, and 6 hours after the administration only on the first day. On days other than the day of administration, whether or not the mice were living and normal condition of the mice were observed in the morning, and in the afternoon, only whether or not the mice were living was checked. In observing the normal condition, whether or not the mice was abnormal in appearance (fur, eyes, ears, nose, anus, and vulvar), behavior, posture, breathing, muscle stress, and enteruria, and the extent of the abnormality were observed with the naked eye, and weights of the mice were measured.
[0115] 10. Pathology inspection: There is no fatal case in the test. The survived mice in the groups therefore were abdominally operated on the fifteenth day under pentobarbital sodium salt anesthesia (100 mg/kg, intraperitoneal administration), and the abdominal great arterio-veins of the mice were cut to euthanize the mice by exsanguinations. After that, the mice were quickly dissected in accordance with pathological manner to observe organs and tissues on the surfaces of the bodies and in orifices, brainpans, chest cavities and abdominal cavities.
[0116] As a result of the experiment, the following became evident.
1. Incidence of Animal Death
[0117] Neither of the groups experienced death nor moribund condition of the mice.
2. Normal Condition
[0118] Neither of the groups experienced changes in normal condition of the mice.
3. Shifts in Weight
[0119] The group in which dosing solution of 1,000 mg/kg was administered and the group in which dosing solution of 2,000 mg/kg was administered showed a (slight) decrease in weight on the day after the administration. In the 2,000 mg/kg administering group experienced a significant decrease, compared with the comparative group. Herein, weight changes in the 1,000 mg/kg and 2,000 mg/kg administering groups from the third day to the fifteenth day were increase similar to those in the comparative group.
4. Pathology Inspection
[0120] In 2/5 cases in the 1,000 mg/kg administering group and 5/5 cases in the 2,000 mg/kg administering group, green-brown (slight) deposition that seemed to be secretory product was found in a site of the administration (subcutaneous tissue of the back of neck) depending on dosing solution weight. Furthermore, 1/5 cases in the 1000 mg/kg administering group experienced (left) testis (slight) diminishing. Abnormal findings other than the testis diminishing were not observed.
[0121] From the foregoing results, in the study of the lethal dose and toxicological appearance in the situation in which secretory product was administered one time subcutaneously in the mice to observe the mice for 15 days, although the weights of the mice on the second day (slightly) decreased depending on the dosing solution weight, weight changes similar to those in the comparative group was observed after the third day, so that is was believed that administering secretory product had a slight degree of influence on the weight changes. In the pathological inspection, although the fact that a (slight) deposition that seemed to be remaining secretory product was found on the site of administration suggested that the secretory product was not be subcutaneously absorbed well, the secretory product was presumably weak irritant because in the site of administration, changes such as inflammatory reaction was not observed. Furthermore, there were not any abnormal findings in other observation sites in the pathological inspection, so that clear toxicity changes originating in the exertion were not found.
[0122] From above results, it was apparent that the minimum lethal dose was 2,000 mg/kg or more because there were not any clear toxicity changes originating in the secretory products, and furthermore, moribund or dead animals were not found. Accordingly, the microorganism secretory product of the present invention is nontoxic, and thus can be used for treatment.
Fifth Embodiment
[0123] Embodiment 5 of the present invention will be explained.
Case 1
[0000]
In case 1, Results of subcutaneously injecting a patient A under treatment for Helicobacter pylori with the novel microorganism of the present invention, together with Helicobacter pylori bacteria scavenging agent.
[0125] Preparation method: The secretory product was extracted in the same manner as in Embodiment 2.
Administration Method: The secretory product of 0.2 g and a normal saline solution were mixed, and administered by subcutaneously injecting the patient A with the mixture twice a day for seven days. Results: The patient A showed gastric improvement 8 days later. The novel microorganism was viewed in any section collected from gastric wall under a microscope. The stomach felt light and free from something lying, heartburn did not occur next morning. Stomach condition was sufficiently improved.
Sixth Embodiment
[0128] Embodiment 6 of the present invention will be explained. When the section collected in Embodiment 5 was subjected to Giemsa staining, the novel microorganism of the present invention was confirmed to make figure-eight movement under a microscope.
INDUSTRIAL APPLICABILITY
[0129] According to the present invention, the novel microorganism was confirmed from the experiments to be able to promote gastric juice secretion, and furthermore, to be nontoxic. The present invention therefore has industrial applicability.
|
Designed to afford a novel microorganism promoting gastric juice secretion and having platelet increasing activity, and to afford a pharmaceutical agent composed of a product secreted by the novel microorganism. The novel microorganism, international deposit number: NITE BP-295, belongs to the species Bacillus pumilus, and is characterized by taking either form of coccus and bacillus, and makes figure-eight movement. The novel microorganism of the present invention is the novel microorganism having the gene represented by SEQ ID No: 1, and an object of the present invention is to afford the microorganism and a gastric juice secretion-promoting composition composed of the product secreted by the novel microorganism.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to sliding mechanisms and, particularly, to a portable electronic device with two or more housings configured with a sliding mechanism such that one housing is allowed to slide with respect to another housing in a longitudinal direction.
2. Description of related art
Portable electronic devices have been increasingly widely used with a multiplicity of functions. A mobile phone is exemplified as a portable electronic device that provides wireless communication services to its subscriber while wirelessly communicating with its base station. Rapid development in the field of information and telecommunication business has made it possible for mobile users to use a variety of functions and types of mobile phones available on the market. These mobile phones are generally classified into three or more types of handsets, such as, e.g., a bar-type handset, a flip-type handset with a flip cover, and a foldable handset with a folding mechanism adapted to be opened and closed about a main body at a given angle.
The sliding type of mobile handset has recently become more widely used. The sliding-type design typically includes two housings in which one housing is slidably opened or closed with respect to the other housing. However, these sliding type mobile handsets do not yet offer a variety of different designs, and for this reason, its users may feel some inconvenience in that they have to manually slide one housing with respect to the other housing in order to open or close it.
Thus, there is room for improvement within the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the sliding mechanism and portable electronic device using the same can be better understood with reference to the following drawings. These drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present sliding mechanism and portable electronic device using the same. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is an isometric view of a mobile handset incorporating a sliding mechanism in a standby state, in accordance with a preferred embodiment.
FIG. 2 is an isometric view of the mobile handset shown in FIG. 1 with a cover slid away from a base.
FIG. 3 is an exploded, isometric view of the sliding mechanism shown in FIG. 2 .
FIG. 4 is a disassembled view of a body of the mobile handset.
FIG. 5 is an assembled view of a body of the mobile handset.
FIG. 5 is an exploded, isometric view of the sliding mechanism shown in FIG. 3 viewed from another aspect.
FIG. 6 is a cut-away view of the mobile handset shown in FIG. 1 along an upper surface of a main board of the sliding mechanism.
FIG. 7 is a cut-away view of the mobile handset shown in FIG. 2 along an upper surface of a main board of the sliding mechanism.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present sliding mechanism is suitable for portable electronic devices with a main body and a slide unit, such as mobile phone handsets, digital cameras, etc.
Referring to the drawings in detail, FIGS. 1 and 2 show an exemplary mobile phone handset 100 . The mobile phone handset 100 includes a base 10 as the main body and a sliding cover 20 as the slide unit. The sliding cover 20 is oriented face-to-face with the base 10 and is slidably movable with respect thereto, due to the sliding mechanism (described below). As illustrated, the base 10 is provided with a keypad section 12 facing towards the sliding cover 20 , and the sliding cover 20 is equipped with a display unit 22 and function key section 24 on its outside. When the mobile phone handset 100 is in a standby state, the keypad section 12 is protected by the sliding cover 20 . Once the sliding mechanism enables the sliding cover to slide relative to the base 10 , the keypad section 12 is exposed and available for use.
Referring now to FIGS. 3 and 4 , the sliding mechanism includes a first plate 32 , a control assembly 34 , an elastic unit 36 and a second plate 38 . The first plate 32 is fixed to the base 10 and the second plate 38 is fixed to the sliding cover 20 . The control assembly 34 and the elastic unit 36 are both configured for positioning in the first plate 32 .
The first plate 32 is generally rectangular and fixed to the base 10 by a screw or a latching mechanism (not shown). The keypad section 12 is configured adjacent to one end of the first plate 32 . A sliding slot 322 is defined in the upper surface 320 of the first plate 32 beside the keypad section 12 . A latching slot 323 is defined perpendicularly to the end of the sliding slot 322 near the keypad section 12 . A control slot 325 is defined between the sliding slot 322 and a side surface 321 of the first plate 32 . The control slot 325 communicates perpendicularly with the sliding slot 322 and the side surface 321 of the first plate 32 . The control slot 325 is divided into three parts, including a first sliding area 3252 adjacent to the side surface 321 , a second sliding area 3254 connected to the sliding slot 322 , and a receiving area 3256 between the first sliding area 3252 and the second sliding area 3234 . The diameter of the receiving area 3256 is larger than the diameters of both the first and second sliding area 3252 and 3254 , and the diameter of the first sliding area 3252 is larger than the diameter of the second sliding area 3256 .
The control assembly 34 includes a reset spring 341 and an operating member 343 . The operating member 343 is generally cylindrical and includes a pressing portion 345 and a resisting portion 347 , and a stopper portion 349 positioned between the pressing portion 345 and the resisting portion 347 . The diameter of the pressing portion 345 is lager than the diameter of the resisting portion 347 . The stopper portion 349 is a flange at one end of the pressing portion 345 , and the diameter of the stopper portion 349 is larger than the pressing portion 345 .
Referring to FIG. 4 , the reset spring 341 is coiled around the resisting portion 347 , and then received in the control slot 325 . The pressing portion 345 is received in the first sliding area of the control slot 325 and partly exposed out of the control slot 325 for contact by a user's finger or palm. The stopper portion 349 and the reset spring 341 are retained in the receiving area 3256 of the control slot 325 . The resisting portion 347 is received in the receiving area 3256 and the second sliding area 3254 . The resisting portion 347 is slightly recessed in the control slot 325 and forms a space between the free end of resisting portion 347 and the sliding slot 322 . One end of the reset spring 341 resists the inner wall of one end of the receiving area 3256 , the other end of reset spring 341 contacts with the stopper portion 349 and abuts the inner wall of the other end of the receiving area 3256 . Due to a compression force of the reset spring 341 , the operating member 343 can stably received in the control slot 325 .
The elastic unit 36 includes a retaining member 361 and a main spring 362 . The retaining member 361 includes a rectangular base 363 having a first retaining protrusion 365 protruding from a surface of the base 363 . A pair of first positioning blocks 367 are configured in both sides of the first retaining protrusion 365 and form an arc space therebetween. Referring to FIG. 5 , one end of the main spring 362 is coiled around the first retaining protrusion 365 , and then the main spring 362 and the retaining member 361 are received in the sliding slot 322 , with the base 363 of the retaining member 361 received in the latching slot 323 .
The second plate 38 is generally rectangular. An exemplary second plate 38 is an inner housing of the sliding cover 20 . The second plate 38 is fixed to the sliding cover 20 by a screw or a latching mechanism (not shown). A sliding member 381 protrudes from a surface 380 of the second plate 38 facing the first plate 32 and slidably cooperates with the sliding slot 322 . The sliding member 381 includes a base block 382 . A second retaining protrusion 383 protrudes from a surface of the base block 382 . A pair of second positioning block 385 is configured in both sides of the second retaining protrusion 383 and form an arc space therebetween. One end of the main spring 362 is coiled around the second retaining protrusion 383 . A through hole 387 is defined through the base block 382 and is axially perpendicular to the second retaining protrusion 383 .
A positioning assembly 389 is configured and received in the through hole 387 . The positioning assembly 389 includes a first sliding block 3891 , a positioning spring 3893 and a second sliding block 3895 . Both of the first sliding block 3891 and the second sliding block 3895 are stage-shaped columns each of which includes two columns of different diameters. A smaller end of the first sliding block 3891 is used as a first latching portion 3892 to fix the positioning spring 3893 . A smaller end of the second sliding block 3895 is used as a second latching portion 3896 for positioning the sliding member 381 . The first sliding block 3891 , the positioning spring 3893 and the second sliding block 3895 are received in the through hole 387 . One end of the positioning spring 3893 is coiled around the first latching portion 3892 , the other end resists the second sliding block 3895 . In a normal state of the positioning spring 3893 , the second latching portion 3896 is exposed out of the through hole 387 .
When being assembled, the control assembly 34 is received in the control slot 325 in the first plate 32 . The retaining member 361 of the elastic unit 36 is fixed in one end of the sliding slot 322 . One end of the main spring 362 is fixed to the retaining member 361 . The sliding member 381 on the second plate 38 is received in the sliding slot 322 and resists the other end of the main spring 362 .
When used, in a standby state, the second plate 38 is closed relative to the first plate 32 . The sliding member 381 compresses the main spring 362 , to make the through hole 387 face and communicate with the control slot 325 . The second latching portion 3896 is inserted into the second sliding area 3254 of the control slot 325 , in the space adjacent the free end of the resisting portion 347 , thereby retaining the first plate 32 and second plate 38 in a fixed relative position.
If the second plate 38 should be slid away from the first plate 32 , a user can press the pressing portion 345 of the control assembly 34 to cause the resisting portion 347 to push the second latching portion 3896 out from the control slot 325 and into the through hole 387 . The positioning spring 3893 is compressed. With the release of the stored compression force of the main spring 341 by the release of the latching action of latching portion 3896 and control slot 325 , the sliding member 381 automatically slides to the other end of the sliding slot 322 . When the pressing portion 345 is released, with a compression force of the reset spring 341 , the operating member 343 automatically returns to its initial position. And then, the second plate 38 slides relative to the first plate 32 , and the keypad section 12 is exposed.
If the second plate 38 should be closed relative to the first plate 32 , a user can push the second plate 38 along the sliding slot 322 until the sliding member 381 connects with the control slot 325 , and the through hole 387 in the sliding member 381 communicates with the control slot 325 . With a compression force of the positioning spring 3893 , the second latching portion 3896 of the sliding member 381 is exposed out of the through hole 387 and inserted into the control slot 325 . The second plate 38 stops and is latched in a fixed position relative to the first plate 32 and the keypad section 12 in the base 10 is shielded.
It should be understood that, one end of the main spring 362 can be welded or bonded with the first plate 32 in one end of the sliding slot 322 , so that the latching slot 323 and the retaining member 361 can be omitted. The other end of the main spring 362 can also be fixed to the sliding member 381 by welding or bonding. Additionally, the through hole 387 can also be omitted. The first sliding block 3891 , the positioning spring 3893 and the second sliding block 3895 can be an elastic member protruding on the sidewall of the sliding member instead. With an outer force, the elastic member can be shrunk to the sidewall of the sliding member 381 . Furthermore, each of the reset spring 341 , the main spring 362 and the positioning spring 3893 can be instead with an elastic member made of elastic material.
Moreover, a protrusion or a recess can be defined in the sidewall of the sliding slot 322 along the sliding direction of the second plate 38 , another recess corresponding to the protrusion or another protrusion corresponding to the recess can be defined in a side surface of the sliding member 381 parallel to the sidewall of the sliding slot 322 . The corresponding protrusion and recess engage with each other to prevent the sliding member 38 pop out of the sliding slot 322 . Of course, the first plate 32 and the second plate 38 can be connected by another ways, such as by connecting rail.
A main advantage of the sliding mechanism and the portable electronic device 100 using the same is that, the second plate 38 can be slid away from the first plate 32 by only one key, that is, just by pressing the operating member 341 .
It is to be understood, however, that even through 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.
|
A sliding mechanism includes a first plate ( 32 ) having a sliding slot ( 322 ) and a control slot ( 325 ) defined therein. The sliding slot and the control slot having a certain angle therebetween and communicating with each other. A second plate ( 38 ) is longitudinally slidably connected to the first plate. The second plate including a sliding member ( 381 ) formed on a surface thereof facing the first plate. The sliding member engages with the sliding slot and includes an elastic positioning assembly ( 389 ). A control assembly ( 34 ) is slidably received in the control slot. A main elastic member ( 36 ) has one end thereof being fixed to one end of the sliding slot, the other end thereof being fixed with the sliding member. A portable electronic device ( 100 ) using the sliding mechanism is also disclosed.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a fermentative product. In particular, the present invention relates to a method for producing a useful substance such as an amino acid by fermentation utilizing a microorganism, and a microorganism to which resistance to stress that suppresses growth of the microorganism and/or production of a fermentative product by the microorganism is imparted.
When a cell is exposed to stress, such as high temperature, high osmotic pressure, metabolic inhibition, presence of heavy metal, and viral infection, synthesis of a family of proteins called “heat shock protein” (abbreviated as “HSP” hereinafter) is induced in a short period of time to cause defensive reactions against the stress. These HSPs show homology in a wide range from prokaryotic cells to eukaryotic cells, and they are roughly classified into several groups such as HSP60, HSP70, HSP90, TRiC, and other groups (Hendrick, J. P. and Hartl, F.-V., Annu. Rev. Biochem., 62, 349-384 (1993)).
The mechanism of the stress resistance imparted by the HSP is based on the function of the HSP to form higher-order structure of proteins (folding of proteins). Namely, the HSP can bind to a protein that has been denatured due to stress and become unable to form a correct higher order structure, and restore the normal function of the protein by refolding it into the correct higher order structure.
Because it has been elucidated that such function of the HSP in the formation of higher order structure of proteins serves as a molecular chaperon not only for denatured proteins but also for assembly, transmembrane transport and the like of proteins in normal cells, its importance has been recognized, and is attracting attentions (Ellis, R. J. et al., Science, 250, 954-959 (1990)). The term “chaperon” implies a supporter, and the name is given because the HSP exerts its function by binding to various proteins.
The expression of the HSP is induced when a cell is exposed to the stress as mentioned above. This induction is usually temporary. It is attenuated soon and reaches a new steady state. It has been revealed that this induction of the HSP is caused at transcription level (Cowing, D. C. et al., Proc. Natl. Acad. Sci. USA, 80, 2679-2683 (1985), Zhou, Y. N. et al., J. Bacteriol., 170, 3640-3649 (1988)). It has been known that a group of HSP genes commonly have a promoter structure called heat shock promoter, and that a factor specifically functioning for this heat shock promoter, σ−32 (σ 32 ) is present. It has also been known that σ 32 is encoded by rpoH gene, and it is a protein with a very short half life, about 1 minute, and closely relates to the temporary induction of the HSP (Straus, D. B. et al., Nature, 329, 348-351 (1987)). It has been shown that the expression control of σ 32 itself is attained at transcription level and translation level, but its major control is attained at translation level.
The induction of the HSP by heat shock is based on two mechanisms, i.e., increase in synthesized amount and stabilization of σ 32 . Among these mechanisms, as for the increase of synthesis amount of σ 32 , it has been revealed that the structure of σ 32 mRNA modified by heat enhances its translation (Yura, T. et al., Annu. Rev. Microbiol., 47, 321-350 (1993)). As for the stabilization of σ 32 , involvement of an HSP (DnaK etc.) in the decomposition of σ 32 has been shown, and it is considered that feedback control by the HSP works (Tilly, K. et al., Cell, 34, 641-646 (1983), Liberek and K., Proc. Natl. Acad. Sci. USA, 89, 3516-3520 (1994)).
As for Escherichia coli ( E. coli ), a relationship between the HSP and growth of cells under the presence of stress have been known (Meury, J. et al., FEMS Microbiol. Lett., 113, 93-100 (1993)), and it has also been known that dnaK and groE affect on the-production of human growth hormones and the secretion of procollagenase, respectively (Hockney, R. C., Trends in Biotechnology, 12, 456 (1994)).
International Publication No. WO96/26289 describes that resistance to stress that inhibits microorganism growth and/or fermentative product production can be imparted to a microorganism by introducing at least one of a gene coding for an HSP and a gene coding for a σ factor which specifically functions for an HSP, into the microorganism to enhance an expression amount of an HSP.
SUMMARY OF THE INVENTION
The object of the present invention is, in the production of a useful substance such as an amino acid by fermentation, to further improve productivity and yield of the fermentative product by reducing the influence of stress that inhibits microorganism growth and/or fermentative product production.
The present inventors conducted studies in order to achieve the aforementioned object. As a result, they sound that the productivity and the growth could be further improved under a high stress condition by introducing a gene coding for HSP derived from a hyperthermophilic archaeon strain KOD-1 into a microorganism to express the HSP, and accomplished the present invention.
Thus, the present invention provides a method for producing a fermentative product by utilizing a microorganism, the method comprising culturing the microorganism in a medium to produce and accumulate the fermentative product in the medium, and collecting the fermentative product, wherein the microorganism expresses an HSP derived from the hyperthermophilic archaeon strain KOD-1 in a cell of the microorganism by introduction of a gene coding for the HSP.
The present invention also provides a microorganism producing a fermentative product, which expresses an HSP derived from the hyperthermophilic archaeon strain KOD-1 in a cell of the microorganism by introduction of a gene coding for the HSP.
In the aforementioned method and-microorganism of the present invention, the fermentative product may be, for example, an amino acid such as L-threonine, L-lysine, L-glutamic acid, L-leucine, L-isoleucine, L-valine, and L-phenylalanine, a nucleic acid or a nucleoside such as guanylic acid, inosine, and inosinic acid, a vitamin, an antibiotic or the like, and an amino acid is preferred.
As the microorganism to which the present invention can be applied, bacteria belonging to the genus Escherichia and coryneform bacteria can be mentioned.
According to the present invention, in the production of useful substances such as amino acids by fermentation, the influence of stress can be further decreased, and productivity and yield can be further improved.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is an explanatory drawing representing the construction of plasmid pMWcpkB.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be explained in detail hereinafter.
The fermentative product to which the present invention can be applied is not particularly limited so long as it can be produced by fermentation utilizing a microorganism. Examples thereof include those produced by microorganisms, for example, various L-amino acids such as L-threonine, L-lysine, L-glutamic acid, L-leucine, L-isoleucine, L-valine, and L-phenylalanine, nucleic acids and nucleosides such as guanylic acid, inosine, and inosinic acid, vitamins, antibiotics and the like. Moreover, the present invention may be applied even to a substance that is not produced by utilizing microorganisms at present, once it becomes to be produced by utilizing microorganisms according to genetic recombination technique or the like. Among the aforementioned substances, the method of the present invention can be suitably applied to those secreted and accumulated in a medium and thereby increasing osmotic pressure of medium, especially, like amino acids.
The microorganism which is used to express the HSP derived from the hyperthermophilic archaeon strain KOD-1 in its cell by introduction of a gene coding for the HSP is not particularly limited so long as it produces a fermentative product by fermentation. Examples thereof include those conventionally used for the production by fermentation, for example, bacteria belonging to the genus Escherichia, coryneform bacteria, bacteria belonging to the genus Bacillus, bacteria belonging to the genus Serratia and the like. The microorganism is preferably a microorganism of which DNA fragment containing a replication origin for plasmid is obtained, and in which the aforementioned HSP gene can function, and copy number of the gene can be increased. The aforementioned coryneform bacteria refer to those of the microorganism class defined in Bargey's Manual of Determinative Bacteriology, 8th Edition, p. 599 (1974), and are aerobic, gram positive and non-acid-fast bacilli not having spore-forming ability. They include bacteria belonging to the genus Corynebacterium, those of bacteria belonging to the genus Brevibacterium formerly categorized into the genus Brevibacterium but currently classified as bacteria belonging to the genus Corynebacterium, and bacteria belonging to the genus Brevibacterium close to bacteria belonging to the genus Corynebacterium.
Specifically, such a microorganism as mentioned above may be Escherichia coli VKPM B-3996 (RIA1867, see U.S. Pat. No. 5,175,107), Corynebacterium acetoacidophilum AJ12318 (FERM BP-1172, see U.S. Pat. No. 5,188,949) or the like for L-threonine; Escherichia coli AJ11442 (NRRL B-12185 and FERM BP-1543, see U.S. Pat. No. 4,346,170), Escherichia coli W3110 (tyrA) (this strain can be obtained by removing plasmid pHATerm from Escherichia coli W3110 (tyrA)/pHATerm (FERM BP-3653), see International Publication No. WO95/16042), Brevibacterium lactofermentum AJ12435 (FERM BP-2294, see U.S. Pat. No. 5,304,476), Brevibacterium lactofermentum AJ3990 (ATCC 31269, see U.S. Pat. No. 15 4,066,501) or the like for L-lysine; Escherichia coli AJ12624 (FERM BP-3853, see French Patent Publication No. 2,680,178), Brevibacterium lactofermentum AJ12821 (FERM BP-4172, Japanese Patent Application Laid-Open No. 5-26811 (1993), French Patent Publication No. 2,701,489), Brevibacterium lactofermentum AJ12475 (FERM BP-2922, see U.S. Pat. No. 5,272,067), Brevibacterium lactofermentum AJ13029 (FERM BP-5189, see International Publication No. WO96/06180) or the like for L-glutamic acid; Escherichia coli AJ11478 (FERM P-5274, see Japanese Patent Publication No. 62-34397 (1987)), Brevibacterium lactofermentum AJ3718 (FERM P-2516, see U.S. Pat. No. 3,970,519) or the like for L-leucine; Escherichia coli KX141 (VKPM B-4781, see European Patent Publication No. 519,113), Brevibacterium flavum AJ12149 (FERM BP-759, see U.S. Pat. No. 4,656,135) or the like for L-isoleucine; Escherichia coli VL1970 (VKPM B-4411, see European Patent Publication No. 519,113), Brevibacterium lactofermentum AJ12341 (FERM BP-1763, see U.S. Pat. No. 5,188,948) or the like for L-valine; Escherichia coli AJ12604 (FERM BP-3579, Japanese Patent Application Laid-Open No. 5-236947 (1993), European Patent Publication No. 488,424), Brevibacterium lactofermentum AJ12637 (FERM BP-4160, see French Patent Publication No. 2,686,898) or the like for L-phenylalanine.
The microorganism of the present invention is such a microorganism as mentioned above in which the HSP derived from the hyperthermophilic archaeon strain KOD-1 is expressed in its cell by introducing a gene coding for the HSP. By this expression of the HSP, resistance to stress that inhibits growth of the microorganism and/or production of the fermentative product by the microorganism is given to the microorganism.
The gene coding for the HSP of the hyperthermophilic archaeon strain KOD-1 is preferably introduced in such a manner that the expression amount of the HSP should be increased. Specifically, the copy number of an HSP gene in a cell can be increased by utilizing a vector autonomously replicable in a microbial cell, especially a multi-copy type plasmid, as a vector for introduction of the HSP gene into the microbial cell. Further, the expression of HSP can also be efficiently enhanced by increasing the expression amount per HSP gene through use of a promoter having high expression efficiency.
The gene coding for the HSP derived from the hyperthermophilic archaeon strain KOD-1 can be obtained by the method described in Japanese Patent Application Laid-Open No. 9-173078 (1997). Specifically, it can be obtained by, for example, the method by performing PCR utilizing chromosome DNA prepared from the hyperthermophilic archaeon strain KOD-1 (Appl. Environ. Microbiol., 60 (12), 4559-4566 (1994)) as a template, and oligonucleotides prepared based on the nucleotide sequence of the gene coding for the HSP derived from the hyperthermophilic archaeon strain KOD-1 disclosed in Japanese Patent Application Laid-Open No. 9-173078 (1997) and the like as primers. Examples of the oligonucleotides used for the primers are oligonucleotides having the nucleotide sequences shown as SEQ ID NOS: 8 and 9 in Japanese Patent Application Laid-Open No. 9-173078 (1997).
The gene coding for the HSP of the hyperthermophilic archaeon strain KOD-1 can also be obtained as a plasmid incorporating a DNA fragment containing this gene. As such a plasmid, plasmid pTrc99AcpkB can be mentioned, and Escherichia coli JM109 harboring this plasmid pTrc99AcpkB was designated as Escherichia coli AJ13478, and it was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code 305-0046, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken, Japan) on Jul. 8, 1998, and received an accession number of FERM P-16887. This deposition was thereafter transferred to an international deposition under the Budapest Treaty on Jun. 14, 1999, and received an accession number of FERM BP-6758.
In order to introduce the gene obtained as described above into a bacterium belonging to the genus Escherichia, for example, a DNA fragment containing the aforementioned gene can be ligated to a vector DNA which can autonomously replicate in a cell of the bacterium, and the bacterium can be transformed with the obtained recombinant vector. In order to introduce the above gene into a microorganism other than bacteria belonging to the genus Escherichia, for example, a DNA fragment containing the aforementioned gene can be ligated to a vector DNA which can autonomously replicate in the microorganism, and the microorganism can be transformed with the obtained recombinant vector.
As the vector DNA that can be used in the present invention, a plasmid vector DNA is preferred. When the microorganism into which the gene is introduced is a bacterium belonging to the genus Escherichia, pUC19, pUC18, pBR322, pHSG299, pHSG399, RSF1010 and the like can be used, for example. Vectors of phage DNA can also be utilized. In order to obtain efficient expression of the HSP, a promoter functioning in microorganisms, such as lac, trp, and PL, may be used instead of the promoter of the HSP gene's own. In order to introduce the HSP gene into a microorganism, a DNA containing the gene can be incorporated into a chromosome of the aforementioned microorganism by a method utilizing a transposon (Berg, D. E. and Berg, C. M., Bio/Technol., 1, 417 (1983)), Mu phage (Japanese Patent Application Laid-Open No. 2-109985 (1990)), or homologous recombination (Experiments in Molecular Genetics, Cold Spring Harbor Lab. (1972)). Moreover, when the microorganism to which the gene is introduced is a coryneform bacterium, a plasmid vector which can autonomously replicate in coryneform bacteria, for example, pMA330 (see Japanese Patent Publication No. 1-11280 (1989)), pHM1519 (see Japanese Patent Application Laid-Open No. 58-77895 (1983)) and the like can be used.
The transformation can be attained according to conventional production of transformants of microorganisms. For example, bacteria belonging to the genus Escherichia can be transformed by the method of D. A. Morrison (Methods in Enzymology, 68, 326 (1979)) or a method in which recipient cells are treated with calcium chloride to increase permeability for DNA (Mandel, M. and Higa, A., J. Mol. Biol., 53, 159 (1970)). The transformation of coryneform bacteria can be attained by the aforementioned method of Mandel et al., or a method utilizing introduction of DNA into a cell at a growth phase (so-called competent cell) so that the cell can incorporate the DNA as reported for Bacillus subtilis (Duncan, C. H., Wilson, G. A., and Young, F. E., Gene, 1, 153 (1977)). It is also possible to prepare a protoplast or spheroplast of a DNA-recipient strain, which readily incorporates DNA, and introduce DNA into it as known for Bacillus subtilis , Actinomycetes and yeast (changs, S. and Choen, S. N., Molec. Gen. Genet., 168, 111 (1979); Bibb, M. J., Ward, J. M. and Hopwood, O. A., Nature, 274, 398 (1978); Hinnen, A., Hicks, J. B., and Fink, G. R., Proc. Natl. Acad. Sci. USA, 75, 1929 (1978)). Further, it is also possible to introduce a recombinant DNA into bacteria belonging to the genus Brevibacterium or Corynebacterium by utilizing the electric pulse technique (Sugimoto et al., Japanese Patent Application Laid-Open No. 2-207791 (1990)).
When an ordinary microorganism is exposed to stress such as elevation of culturing temperature, high osmotic pressure caused by a fermentative product, a high concentration medium ingredient or the like, or metabolic abnormality associated with the production of a target fermentative product, its growth may be inhibited or the productivity of the fermentative product may be reduced. However, by expressing the HSP derived from the hyperthermophilic archaeon strain KOD-1, excellent resistance to the stress can be imparted to the microorganism. As a result, the productivity of the fermentative product can further be improved under the circumstance where the microorganism is exposed to such stress as mentioned above. Therefore, the expression of the above HSP in a microorganism to which the gene coding for the HSP derived from the hyperthermophilic archaeon strain KOD-1 strain has been introduced to express the HSP in its cell may also be confirmed by evaluation of the above stress resistance, in addition to direct detection of the HSP.
The resistance to stress may not be complete resistance, and also implies a characteristic to decrease the influence from the stress. Further, depending on the kind of genes to be introduced and the kind of host microorganisms, both of the inhibition of growth and the reduction of the yield of the fermentative product are not necessarily improved, and only the yield of the fermentative product may be improved while the growth may be inhibited. The stress to which resistance can be given by the method of the present invention includes temperature (e.g., elevated temperature), osmotic pressure of medium (e.g., high osmotic pressure), high concentration of an amino acid in a medium and the like, which are undesirable for the microorganism growth.
The medium for the production by fermentation used for the present invention may be a conventionally-used well-known medium. Namely, it may be an ordinary medium containing a carbon source, a nitrogen source, inorganic ions, and other organic components as required. Any special medium is not required for the practice of the present invention.
As the carbon source, a saccharide such as glucose, lactose, galactose, fructose and starch hydrolysates, an alcohol such as glycerol and sorbitol, an organic acid such as fumaric acid, citric acid and succinic acid and the like may be used.
As the nitrogen source, an inorganic ammonium salt such as ammonium sulfate, ammonium chloride, and ammonium phosphate, an organic nitrogen source such as soy bean hydrolysates, ammonia gas, aqueous ammonia and the like may be used.
As the trace organic nutrient, it is desirable to add suitable amounts of required substances such as vitamin B 1 , L-homoserine, and L-tyrosine, or yeast extract and the like. Other than these, a trace amount of potassium phosphate, magnesium sulfate, iron ions, manganese ions and the like are added as required.
The culture may be performed under conditions selected from the conventionally-used well-known conditions depending on the kind of microorganisms to be used. For example, the culture may be performed under an aerobic condition for 16 to 120 hours while controlling fermentation temperature from 25 to 45° C., and pH from 5 to 8. In order to adjust pH, organic or inorganic acidic or alkaline substances, and ammonia gas and the like may be used.
Any special means is not required in the present invention for the collection of fermentative product from the culture medium after the culture is completed. Namely, the metabolic product produced according to the present invention can be collected by a well-known conventional means, for example, ion exchange chromatography, precipitation, any combination of these or other techniques or the like.
EXAMPLES
The present invention will be explained more specifically with reference to the following examples.
Example 1
L-Lysine production by L-lysine-producing Escherichia coli into which gene coding for HSP derived from the hyperthermophilic archaeon strain KOD-1 (cpkB gene) is introduced.
Escherichia coli W3110 (tyrA) was used as a host for L-lysine production. While the strain W3110 (tyrA) is described in European Patent Publication No. 488424 in detail, the preparation method therefor will be outlined below. E. Coli W3110 was obtained from the National Institute of Genetics (Mishima-shi, Shizuoka, Japan). This strain was inoculated on a LB plate containing streptomycin, and a streptomycin-resistant strain was obtained by selecting a strain that formed a colony. The cells of the selected streptomycin-resistant strain and E. coli K-12 ME8424 were mixed, and cultured as standing culture for 15 minutes at 37° C. in a complete medium (L-Broth: 1% Bacto trypton, 0.5% yeast extract, 0.5% NaCl) to induce cell conjugation. The E. coli K-12 ME8424 has genetic characters of (HfrPO45, thi, relA1, tyrA::Tn10, ung-1, nadB), and can be obtained from the National Institute of Genetics. Then, the culture was inoculated to a complete medium (L-Broth: 1% Bacto trypton, 0.5% yeast extract, 0.5% NaCl, 1.5% agar) containing streptomycin, tetracycline, and L-tyrosine, and a strain which formed a colony was selected. This strain was designated as E. coli W3110 (tyrA).
Many strains produced by introducing a plasmid into this strain are disclosed in European Patent Publication No. 488424. For example, a strain produced by introducing plasmid pHATerm into the strain was designated as Escherichia coli W3110 (tyrA)/pHATerm, and it was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code 305-0046, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken, Japan) on Nov. 16, 1991 as an international deposition under the Budapest Treaty, and received an accession number of FERM BP-3653. The Escherichia coli W3110 (tyrA) can be obtained by removing the plasmid pHATerm from the above strain by using an ordinary method.
The plasmid pCABD2 containing lysine biosynthesis genes, which is disclosed in International Publication No. WO95/16042, was introduced into the above Escherichia coli W3110 (tyrA). The transformant into which the plasmid was introduced was selected on an L plate medium (containing 10 g of polypeptone, 5 g of yeast extract, 5 g of NaCl, and 15 g of agar in 1 L of pure water, pH 7.2) containing 50 μg/ml of streptomycin.
On the other hand, a plasmid for introducing cpkB was constructed as follows. A PCR fragment containing the cpkB gene was obtained according to the method described in Example 5 of Japanese Patent Application Laid-Open No. 9-173078 (1997)), and digested with NcoI and BamHI. The excised fragment was cloned between the NcoI and BamHI sites of a vector plasmid pTrc99A (produced by Pharmacia) to obtain a plasmid pTrc99AcpkB. Escherichia coli JM109 harboring the plasmid pTrc99AcpkB was designated as Escherichia coli AJ13478, and it was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (postal code 305-0046, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken, Japan) on Jul. 8, 1998, and received an accession number of FERM P-16887. This deposition was thereafter transferred to an international deposition under the Budapest Treaty on Jun. 14, 1999, and received an accession number of FERM BP-6758. Further, a cpkB gene fragment containing added trc promoter, which was excised by digestion of the plasmid pTrc99AcpkB with EcoRV and BamHI, was cloned between the SmaI and BamHI sites of pMW218 (produced by Wako Pure Chemical Industries) to obtain a plasmid pMWcpkB. The outline of the construction of this plasmid is shown in FIG. 1 . This pMWcpkB was introduced into a cell of Escherichia coli W3110 (tyrA)/pCABD2 by the aforementioned method. A transformant cell into which the plasmid was introduced was selected on L plate medium containing 50 μg/ml of streptomycin and 50 μg/ml of kanamycin.
Further, a plasmid for introducing rpoH gene was constructed as follows. The rpoH gene was amplified by the PCR technique described in Example 1 <1> of International Publication No. WO96/26289, and the obtained amplification product was blunt-ended at the both ends by using a commercially available kit for blunt-ending DNA termini (Blunting kit, produced by Takara Shuzo), and cloned into the HincII site of a vector plasmid pMW119 (produced by Wako Pure Chemical Industries) to obtain a plasmid pMWrpoH. This plasmid was introduced into the Escherichia coli W3110 (tyrA)/pCABD2 by the method mentioned above. A transformant cell into which the plasmid was introduced was selected on L plate medium containing 50 μg/ml of streptomycin and 50 μg/ml of ampicillin.
L-Lysine productivity of the Escherichia coli W3110 (tyrA)/pCABD2 , Escherichia coli W3110 (tyrA)/pCABD2+pMWrpoH, and Escherichia coli W3110 (tyrA)/pCABD2+pMWcpkB obtained as described above was evaluated.
The evaluation of L-lysine productivity of the obtained transformants was performed as follows. The cells were refreshed by culturing them on an L plate medium, and each refreshed transformant was cultured at 37° C. for 30 hours in a medium containing 40 g of glucose, 1 g of KH 2 PO 4 , 0.01 g of MnSO 4 .7H 2 O, 0.01 g of FeSO 4 .7H 2 O, 2 g of yeast extract, 0.1 g of L-tyrosine, 1 g of MgSO 4 .7H 2 O, and 25 g of CaCO 3 in 1 L of pure water (pH was adjusted to 7.0 with KOH). The cells were also cultured in the same manner except that 40 g/L of L-lysine hydrochloride was added at the time of starting the culture. Quantitative assay of L-lysine was performed by using Biotech Analyzer AS210 produced by Asahi Chemical Industry Co., Ltd. The produced amount of L-lysine (the amount obtained by subtracting the initially added amount of L-lysine from the amount of L-lysine in the medium after the culture) was represented as a yield of L-lysine hydrochloride based on the saccharide in the medium (% by weight). The results are shown in Table 1.
TABLE 1
Yield of L-lysine
hydrochloride based on
saccharide(%)
Initially added L-lysine
hydrochloride (g/L)
Strain
0
40
W3110 (tyrA)/pCABD2
30.0
27.4
W3110 (tyrA)/pCABD2 + pMWrpoH
30.2
28.8
W3110 (tyrA)/pCABD2 + pMWcpkB
30.4
29.3
From these results, it is clear that Escherichia coli into which the cpkB gene is introduced exhibits improved L-lysine productivity even in the presence of L-lysine at a high concentration compared with the strain into which the cpkB gene is not introduced and the strain into which the rpoH gene is introduced.
Further, L-lysine productivity was similarly evaluated under the condition that 22 g/L of NaCl was added at the time of starting the culture. The results are shown in Table 2.
TABLE 2
Yield of L-lysine
hydrochloride based on
saccharide(%)
Initially added NaCl (g/L)
Strain
0
22
W3110 (tyrA)/pCABD2
30.0
24.3
W3110 (tyrA)/pCABD2 + pMWrpoH
30.2
25.0
W3110 (tyrA)/pCABD2 + pMWcpkB
30.4
25.5
From these results, it is clear that Escherichia coli into which the cpkB gene is introduced exhibits improved L-lysine productivity even in the presence of NaCl at a high concentration compared with the strain into which the CpkB gene is not introduced and the strain into which the rpoH gene is introduced. Therefore, it has been found that it has excellent resistance to a high osmotic pressure.
Then, the influence of culture temperature for L-lysine production was investigated. L-Lysine productivity was evaluated in the same manner as described above except that the culture was carried out at 37° C. as a standard condition and at 42° C. The results are shown in Table 3.
TABLE 3
Yield of L-lysine
hydrochloride based on
saccharide(%)
Culture temperature (° C.)
Strain
37
42
W3110 (tyrA)/pCABD2
30.0
26.3
W3110 (tyrA)/pCABD2 + pMWrpoH
30.2
27.7
W3110 (tyrA)/pCABD2 + pMWcpkB
30.4
27.9
From these results, it is clear that Escherichia coli into which the cpkb gene is introduced exhibits improved L-lysine productivity even in the culture at a high temperature compared with the strain into which the cpkB gene is not introduced and the strain into which the rpoH gene is introduced.
|
A method for producing a fermentative product by utilizing a microorganism, the method comprising culturing the microorganism in a medium to produce and accumulate the fermentative product in the medium, and collecting the fermentative product, wherein the microorganism expresses a heat shock protein derived from a hyperthermophilic archaeon strain KOD-1 in a cell of the microorganism by introduction of a gene coding for the heat shock protein.
| 2
|
[0001] This is a national stage of PCT/AT2011/000461 filed Nov. 15, 2011 and published in German, which has a priority of Austria, no. A 1897/2010 filed Nov. 17, 2010, hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like in a detector, wherein a charge pulse is generated in the detector when a particle passes through the detector and every charge pulse is subsequently converted into an electric signal and the signal is indicated and/or recorded, in particular after amplification, wherein individual signals are amplified in a first, fast amplifier and/or a plurality of signals are each integrated in a second, slow amplifier. The present invention, moreover, relates to a device for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like, including a detector for generating a charge pulse in the detector when a particle passes therethrough, wherein at least one consecutively arranged amplification device for converting every charge pulse into an electric signal and amplifying the same, and optionally a display and/or recording device, are provided, wherein, a first, fast amplifier for amplifying individual signals and a second, slow amplifier for integrating signals are provided.
PRIOR ART
[0003] In order to detect elementary particles such as protons, ions, electrons, neutrons, photons or the like in a detector, a detection or acquisition is usually performed in that an integration of a plurality of signals is performed at high frequencies or signal rates, wherein, upon amplification during such integration, an electric signal is substantially displayed or recorded as a function of the number or plurality of detected particles. The detection of individual particles can usually only be performed at comparatively low frequencies or signal rates while taking into account the options of a resolution of individual pulses or signals, wherein, as opposed to the integration of signals, such embodiments of detectors or detection devices require completely different structures of amplification and evaluation devices arranged to follow the detector. According to the presently known and available methods and devices, it is necessary to know in advance possible frequencies or signal rates in order to perform, in exceptional cases, a detection of individual particles for adaptation to count or signal rates to be expected, or, in particular with high-energy particles, to acquire data substantially averaged, over an extended or large period of time by an integration of the signals. In known methods and devices, it is thus normally not possible by one and the same device to both detect individual particles and their sequences or pulses over time and use an integration of particles when exceeding a count rate or signal rate in order to maintain a result averaged over an extended period of time.
[0004] A method and a device of the kind mentioned initially can be taken from WO 2007/010448 A2, for example, wherein for a X-ray detector a counting channel and an integrating channel being separate therefrom are provided for allowing a quantitative evaluation of information with a CT scanner, for example.
[0005] Further methods and devices for detecting different radiation and/or elementary particles, sometimes using several, potentially different detectors are known from US 2007/0075251 A1, US 2008/099689 A1, U.S. Pat. No. 3,579,127 A, U.S. Pat. No. 3,805,078 A or WO 97/00456 A1, for example.
SUMMARY OF THE INVENTION
[0006] The invention, therefore, aims to provide a method and device for detecting elementary particles of the initially defined kind, by which the above-mentioned drawbacks of the prior art can be reduced or completely avoided, and, in particular, to provide a method and device which enable both a measurement or detection of individual particles and an integration of count rates, in particular upon exceeding of a given threshold value for signal rates, as a function of such signal rates or desired boundary conditions, without knowing in advance count or signal rates to be expected and allow a reliable detection or evaluation of small-size signals.
[0007] To solve these objects, a method of the initially defined kind is essentially characterized in that discharging of a charge pulse or signal from the detector is performed on the low-voltage side. In that both an amplification of individual signals in a fast amplifier and, or alternatively, an integration of each of a plurality of signals in a second, slow amplifier are performed, it has become possible by a joint method, as opposed to the prior art, to provide both the detection or measurement of individual pulses or signals and the integration thereof, in particular where correspondingly high count rates occur, without knowing in advance count or signal rates to be possibly expected. The method according to the invention thus enables the detection of signals or pulses generated by elementary particles irrespectively of a, previous restriction as required in the prior art in respect to a possible detection of individual particles or an integration of the same. When detecting elementary particles, the detection and evaluation of small-size signals is usually required such that a good signal/noise ratio has to be sought. In order to avoid excessive noise, and enable a simpler distinction of such signals having small sizes relative to a base quantity, for instance a base voltage or a base current, it is thus proposed according to the invention that discharging of a charge pulse or signal from the detector is performed on the low voltage side. In that according to the invention discharging of a charge pulse or signal is provided on the low-voltage side of the detector, the distinction from a background, and/or detection, of small-size signals has become much simpler as compared to the prior art, where signals are tapped or detected on the high-voltage side required for operating the detector. The low-voltage-side discharge or wiring provided by the invention will, in particular, prevent a leakage current in a high-voltage cable possibly having a large length from being detected such that, in the main, the precise measuring of the measurement current of a detector will be enabled.
[0008] According to a preferred embodiment, it is proposed in this context that, as a function of the rate of the electric signals, individual signals are amplified in the first, fast amplifier and signals are integrated in the second, slow amplifier at least upon exceeding of a threshold value of the rate of the signals. In this manner, the measuring or detecting of individual particles is feasible at low rates or frequencies, in particular as a function of the signal rate actually occurring during measuring, while enabling the integration of each of a plurality of signals from at least a threshold value or limit value.
[0009] For a simple and proper subdivision into measurements of individual signals or pulses, or an integration of each of a plurality of detection signal amplifications differing therefrom, it is proposed according to a further preferred embodiment that the signals are separated as a function of the rate by a capacitor preceding at least a first amplifier for amplifying individual low-rate signals, or a high-pass element, and/or by an inductive element preceding at least a second amplifier for amplifying high-rate signals, or a low-pass element. By appropriately selecting the characteristic data or parameters of the elements arranged to precede the individual amplifiers, it has thus become possible, for instance also as a function of different measuring conditions or different elementary particles to be detected, or parameters threreof, to provide, if desired, an adjustment in view of a separate, or optionally also simultaneous, detection of individual signals or pulses as well as an integration of each of a plurality thereof for detecting an averaged value over an extended period of time.
[0010] In particular as a function of the individual elements used for amplification and signal processing, it is proposed according to a further preferred embodiment that amplifications in the different amplifiers are performed at overlapping rates of signals. By detecting signals in the different amplifiers at overlapping rates of signals, a check and, if required, a calibration within the overlapping range with a simultaneous detection of individual signals or pulses as well as an integration of each of a plurality thereof have also become possible, while providing a plurality of different parameters or characteristic data of the detected elementary particles.
[0011] While electrically charged particles generate appropriate electric signals in a detector, it is proposed according to a further preferred embodiment of the method according to the invention for detecting uncharged particles that the detector material is doped or coated with a converter material for the detection of uncharged particles. By providing such a converter material, electric pulses are generated by an uncharged particle when passing through the detector material because of said converter material, which electric pulses will subsequently serve to detect such an uncharged particle.
[0012] In order to detect particles over very wide ranges of possible signal or count rates, or large bandwidths, it is proposed according to a further preferred embodiment that a material enabling fast charge transport at room temperature, e.g. diamond, is used as said detector material. Such detector materials enabling fast charge transports at room temperature, for instance, enable not only the detection of individual particles up to high count or signal rates at a high time resolution, but also the precise and reliable integration of each of a plurality of such pulses or signals. Besides the fastness and insensitiveness to light, the radiation strength of diamond is, for instance, also a selection criterion for such a detector material.
[0013] To solve the above-cited objects, a device of the initially defined kind is, moreover, essentially characterized in that the tapping of the charge pulses or signals is provided on the low-voltage side of the detector, in particular with the arrangement of a support capacitor. As already pointed out above, it has thus become possible to provide both the detection of individual pulses or signals and the detection of a value averaged over an extended period of time by integrating each of a plurality of such signals using a joint device and, for instance, without knowing in advance count rates or signal rates to be expected in particular in order to improve the noise/signal ratio, it is proposed according to the invention that the tapping of the charge pulses or signals is provided on the low-voltage side of the detector, in particular with the arrangement of a support capacitor. As already pointed out above, the detection of an interfering leakage current in a high-voltage cable possibly having a large length can be prevented by tapping the charge pulses or signals on the low-voltage-side. Due to the support capacitor preferably provided by the invention, the discharge of the detector can be rapidly compensated for by the support capacitor, in particular at high beam rates, whereby it is, in particular, possible to keep the detector voltage at normal voltage and maintain the functionality of the detector even at high ionization rates. In this respect, it is essential that the wiring of a support capacitor will only be enabled if the charge pulses or signals are tapped on the low-voltage side as is preferably provided by the invention.
[0014] In this respect, it is proposed according to a preferred embodiment that the second, slow amplifier is provided for integrating signals upon exceeding of a threshold value of the rate of said signals.
[0015] For a reliable and simple separation during the detection of signals of elementary particles when performing a measurement of individual pulses or signals, and/or an integration of each of a plurality thereof, it is proposed according to a further preferred embodiment that, for separating the signals as a function of the rate, at least one amplification element for amplifying low-rate signals is preceded by a capacitor for blocking high-frequency signals, or a high-pass filter, and/or at least one amplifier for amplifying high-rate signals is preceded by an inductive element, or a low-pass filter, for blocking low-rate signals. As already pointed out above, it has become possible, by selecting or adjusting the parameters of the individual elements of the amplifier, or the elements preceding the same, to appropriately adjust the measuring ranges for measuring individual particles, or each integrating the same, optionally by taking into account measuring conditions and/or measuring parameters.
[0016] For instance for calibrating the different measuring methods possible in the device according to the invention within a signal or count rate range in which both a measurement and detection of individual particles or pulses and an integration of the same is possible, it is, moreover, proposed that the capacity of the capacitor and/or the inductance of the inductive element or the properties of the low-pass filter are selected for separating signals at overlapping rates, as in correspondence with a further preferred embodiment of the device according to the invention.
[0017] While, as already mentioned above, the detection of charged Particles is substantially directly enabled as the latter Pass through the detector by generating electric pulses or signals, it is proposed according to a further preferred embodiment for detecting uncharged particles that the detector material is provided with an implanted converter material or at least a coating comprising a converter material for the detection of uncharged particles.
[0018] In particular when taking into account the possibly high count rates or signal rates encountered in the detection of elementary particles, it is proposed according to a further preferred embodiment that a material enabling fast charge transport at room temperature, e.g. diamond, is provided as said detector material.
[0019] To solve the above-cited objects, the invention, moreover, proposes the use of a method according to the invention or a preferred embodiment thereof, or a device according to the invention or a preferred embodiment thereof, for detecting particles in particle accelerators, in reactor installations, in diagnostic devices such as X-ray devices, CT devices or the like.
SHORT DESCRIPTION OF THE DRAWINGS
[0020] In the following, the invention will be explained in more detail by way of exemplary embodiments schematically illustrated in the drawing, Therein:
[0021] FIG. 1 is a schematic wiring diagram of a device according to the invention for carrying out the method of the invention for detecting elementary particles;
[0022] FIG. 2 is a schematic illustration of a detector to be used in a device according to the invention for carrying out the method of the invention, substantially in consideration of the flow chart according to FIG. 1 , FIG. 2 a depicting a schematic top view of such a detector, including an energy supply and a signal discharge, and FIG. 2 b illustrating a section along line II of FIG. 2 a;
[0023] FIG. 3 is a schematic wiring diagram of a first embodiment a first amplifier and a second amplifier disposed downstream of the detector;
[0024] FIG. 4 in an illustration similar to that of FIG. 3 depicts a modified embodiment of a first amplifier disposed downstream of the detector, of a device according to the invention for carrying out the method of the invention;
[0025] FIG. 5 is a schematic illustration of different measuring ranges when measuring individual particles and integrating a plurality of measurements;
[0026] FIG. 6 schematically illustrates different measurements, FIG. 6 a illustrating the measurement or detection of individual signals or pulses, and FIG. 6 b depicting the integration of each of a plurality of signals or pulses;
[0027] FIG. 7 is a schematic illustration of a detector doped with a converter material, with a coating being provided on the surface of the detector material in the embodiment according to FIG. 7 a , and a converter material being partially integrated or doped into the interior of the detector material in the embodiment according to FIG. 7 b;
[0028] FIG. 8 is a further schematic wiring diagram of a device according to the invention for carrying out the method of the invention for detecting elementary particles, which substantially represents a combination of the illustrations according to FIG. 1 and FIG. 3 ; and
[0029] FIG. 9 in an illustration similar to that of FIG. 2 b depicts a section through a modified embodiment of a detector of a device according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] In FIG. 1 , a detector, e.g. a diamond detector, which is supplied via high voltage HV is schematically denoted by 1 , wherein a charging resistor R 3 and a charging capacity C 3 connected to ground via a grounding wire 2 are indicated. Tapping of the signals of the detector 1 is performed on the low-voltage side of the latter via a discharge or signal line 3 .
[0031] In FIG. 2 , a supporting plate 4 is schematically indicated, to which a detector element comprising, for instance, a diamond substrate 5 is mounted, wherein contactings of the detector are indicated by 6 in FIG. 2 b.
[0032] The fixation of the substrate 5 and a contact 6 to the supporting plate 4 is realized by an adhesive 7 .
[0033] In addition, a contact connection to the signal line, which is again denoted by 3 , is indicated via bonding wires 8 in FIGS. 2 a and 2 b.
[0034] The supply of the detector 1 is realized similarly as in the embodiment according to FIG. 1 , via a high-voltage supply HV, wherein a charging resistor is again indicated by R 3 and a charging capacity is again indicated by C 3 , the charging capacity C 3 being again connected to earth via a grounding wire 2 .
[0035] A further grounding wire provided on the low-voltage side is denoted by 9 in FIG. 2 a.
[0036] A signal emitted from the detector 1 reaches an amplification and evaluation unit via signal line 3 as shown in FIG. 3 , wherein, as a function of the frequency or count and/or signal rate as will be discussed in more detail below, an amplification is performed in a first, fast preamplifier 10 and an evaluation is subsequently made in an evaluation unit 11 , such an AC path enabling the detection and processing of individual particles.
[0037] The first, fast amplifier 10 is preceded by a capacitor C 1 so as to ensure, by suitable parameters of the capacitor C 1 , that signals will no longer reach the amplifier 10 and the evaluation unit 11 , for instance upon exceeding of a threshold value.
[0038] In the same manner, the signal line 3 is coupled to a second, slow amplifier 12 , to which signals are fed by the signal line 3 via an inductance L 1 , wherein an evaluation unit 13 of the signals to be integrated is provided downstream of the second, slow amplifier 12 in a so-called DC path. Similarly, it will be ensured by selecting suitable parameters of the inductance or inductive element L 1 that an amplification by an integration of each of a plurality of signals in the DC path will only be enabled if the number of signals has exceeded a given threshold value.
[0039] FIG. 4 depicts a modified embodiment, wherein the first, fast amplifier 10 is again preceded by a capacitor C 1 similarly as in the embodiment according to FIG. 3 .
[0040] In the modified embodiment according to FIG. 4 , the amplifier 12 and the evaluation unit 13 are preceded by a low-pass element comprised of a resistor R 1 of a capacity, or a capacitor C 2 , instead of the inductive element provided in FIG. 3 .
[0041] The fast, first amplifier 10 may be preceded by a high-pass element instead of the capacitor C 1 preceding the fast, first amplifier 10 , similarly to the low-pass element comprised of elements R 1 and C 2 .
[0042] Also in the embodiment according to FIG. 4 , splitting or partitioning of the signals fed via the signal line 3 is effected into an AC path formed by elements 10 and 11 for detecting and evaluating individual pulses or signals and a DC path formed by elements 12 and 13 for integrating each of a plurality of signals or pulses.
[0043] In FIG. 5 , it is schematically illustrated how either a separation or subdivision into substantially different measuring ranges or different pulse or signal rate ranges, or a respective overlap, can be achieved by the appropriate selection of the elements preceding the amplifiers 10 and 12 , respectively, with both a detection of individual particles and, at the same time, an integration of each of a plurality, of signals being feasible in the overlapping range.
[0044] In the schematic diagram according to FIG. 5 , full lines I and II are each indicated in a frequency or rate range, wherein the measuring of individual signals according to the AC path formed by elements 10 and 11 is performed up to a limiting frequency f 1 , with the sensitiveness for detecting individual signals decreasing subsequently.
[0045] The detection of signals each by integrating a plurality thereof according to the DC path formed by elements 12 and 13 is substantially made starting from a frequency or rate f 2 according to full line II. With such a selection of the parameters for the elements preceding the amplifiers 10 and 12 , substantially no detection of signals will thus occur in a subrange lying therebetween.
[0046] According to broken lines III, and IV, it is, on the other hand, provided that the detection of individual signals takes place up to a frequency f 3 , while an integration of signals is already effected from a frequency or rate f 4 , which is lower than the frequency or rate f 3 , so that in the overlapping range between rates f 4 and f 3 a detection and evaluation both according to the AC path using elements 10 and 11 and according to the DC path using elements 12 and 13 are performed.
[0047] FIGS. 6 a and 6 b schematically illustrate results or wave forms obtainable both by a measurement of individual particles and by integration, an arbitrary unit (a.u.) being each indicated on the ordinate for a measured quantity.
[0048] From FIG. 6 a , the detection of individual pulses or signals is clearly apparent, which can each be generated and detected by an individual particle as the latter passes through the detector 1 or impinges on the same, while the illustration according to FIG. 6 b substantially depicts an average over an extended period of time each by detecting and integrating several signals or pulses.
[0049] While during the detection of electrically charged particles, the latter trigger or cause electric signals immediately upon entry into or passage through a detector, which electric signals can subsequently be detected and evaluated in the manner described above, it is provided for the detection of uncharged particles that a detector material, which is denoted by 15 in FIG. 7 , is coated with a converter material 16 on one of its surfaces, the direction of an impinging particle or particle flow being indicated by arrow 17 .
[0050] Instead of the coating illustrated in FIG. 7 a with a converter material, such a converter material 18 can also be implanted into the detector material 15 , or the detector material 15 can be doped with the same, as is indicated in FIG. 7 b.
[0051] In particular as a function of the particles or signals to he determined or detected, it is, moreover, also possible to provide, for instance, a layered structure each comprising layers of a converter material alternating with layers of a detector material.
[0052] FIG. 8 is an illustration of a modified embodiment, said illustration substantially combining the illustrations according to FIGS. 1 and 3 such that the reference numerals of said preceding Figures have been retained for identical elements.
[0053] From FIG. 8 , it is apparent that tapping of the signals is again effected on the low-voltage side by a detector schematically denoted by 1 via a signal line 3 , wherein, as in the preceding embodiments, amplification, in a first, fast amplifier 10 according to the frequency or count and/or signal rate and subsequently in an evaluation unit 11 according to an AC path are performed for detecting individual particles.
[0054] The signal line 3 is again coupled via an inductance L 1 to a second, slow amplifier 12 and an evaluation unit 13 of the signals to be integrated in the so-called DC path.
[0055] From FIG. 8 , the support capacitor C 3 is clearly apparent, which has an essential task, in particular at high beam rates. The detector 1 is in each case discharged by ionization, discharging of the detector 1 causing the voltage on the detector 1 to break down and hence the functionality of the detector 1 to be lost. Such discharging is rapidly compensated for by the support capacitor C 3 , with the detector voltage remaining at nominal voltage and, the functionality of the detector I thus being preserved even at high radiation or ionization rates. Such a wiring or arrangement of a support capacitor C 3 is possible with a low-side wiring or a low-voltage-side tap of the signals, as is clearly apparent from FIG. 8 .
[0056] A cable 19 possibly having an extremely large length is additionally indicated in FIG. 8 on the high-voltage side HV. Such a cable may lead to a high leakage current, and hence an error source in the detection of the measurement current of the detector, any influence of such a leakage current being again prevented by the low-voltage-side wiring of the measuring electronics, as is clearly apparent from FIG. 8 .
[0057] FIG. 9 depicts a modified embodiment of a contact connection of a detector denoted by 21 . In said detector 21 , a detector element, which is again denoted by 5 and, for instance, comprised of diamond, is disposed on a base plate 22 , wherein an intermediate plate 23 and a cover plate 24 are, moreover, indicated in FIG. 9 .
[0058] In this embodiment, contacting of the detector element 5 is realized by spring elements 25 formed, for instance, by gold-plated beryllium springs. In this case, a contact pressure is applied purely mechanically by the clamping of the spring elements 25 , while, for instance, in the embodiment illustrated in FIG. 2 b contacting is provided by gluing and/or bonding.
[0059] The suitable selection of the dimensions between the individual plate-shaped elements 22 , 23 and 24 ensures the safe clamping, and hence reliable contacting, of the spring-shaped contact element 25 while simultaneously protecting the detector material.
[0060] In order to optimize the read-out performance of the detector 1 or 21 , respectively, the former is, for instance, optimized to a wave resistance of 50 ohms. This will result in the optimum adaptation to the input impedance of a preamplifier of likewise 50 ohms, and to the wave resistance of a 50-ohm-cable optionally provided between the detector and the preamplifier.
[0061] As a function of the elementary particles to be detected, it may be provided that packets of such particles each comprising more than a single particle are detected. Such packets, which, for instance in a particle accelerator, may comprise an extremely small distance of, e.g., less than 100 ns, in particular about 25 to 50 ns, can each be detected as a packet, wherein pulse heights will, in particular, be summed up in order to enable a statement or assessment as to the overall particle rate.
[0062] By enabling both the measurement or detection of individual particles in the processing or treatment of the signals derived from the detector over the AC path formed by elements 10 and 11 and the detection of each of a plurality of particles by an integration of the same, in particular at high rates or frequencies, it has thus become possible to provide an appropriate detection of elementary particles without knowing in advance signal rates to be expected.
[0063] Such a detection of elementary particles, for instance, is of special interest in the context of scientific examinations, e.g. in particle accelerators or particle detectors. The option of both detecting individual particles or pulses or signals and integrating the same can, for instance, also be used for measuring the intensity in particle accelerators or similar installations, both for supervision and, for instance, for detecting the actual formation of a particle beam.
[0064] In addition, such a detection of individual signals or particles and the substantially simultaneous integration thereof can, for instance, be used in the field of medical technology both for diagnosing and, for instance, for imaging processes, whereby monitoring to avoid overdosing has also become possible.
[0065] Similarly, the substantially simultaneous detection and integration of individual particles can also be used in electrical power engineering applications, e.g., in the context of the development of reactors.
|
Provision is made in a method and a device for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like in a detector, wherein a charge pulse is generated in the detector when a particle passes through the detector and every charge pulse is subsequently converted into an electric signal and the signal is indicated and/or recorded in particular after amplification, for individual signals to be amplified in a first, fast amplifier and/or in each case a plurality of signals to be integrated in a second, slow amplifier, as a result of which it becomes possible for individual particles to be detected and in particular at increased signal or count rates for an integration thereof to be provided.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotor type open-end spinning unit. More particularly, this invention relates to a spinning frame that has an outer rotor, which is provided with a collecting section for collecting opened fibers supplied, and an inner rotor, which is provided inside the outer rotor and is driven independently of the outer rotor.
2. Description of the Related Art
In an ordinary rotor type open-end spinning frame, a supplied sliver is opened by a combing roller and foreign matter is expelled. The opened fibers are supplied into a rotor by an airstream produced in a fiber transport channel due to negative pressure in the rotor, that rotates at a high speed. The fibers are then collected at a fiber-collecting section at the largest inner diameter portion of the rotor. The collected fibers are drawn from a guide hole or a yarn drawing passage, provided in the center of a navel, by a draw roller, and is simultaneously twisted in accordance with the rotation of the rotor to form a yarn. The yarn is then wound around a bobbin as a package.
It is known that open-end spinning frames have a higher productivity than ring spinning frames. In general, however, a fabric woven with yarn produced by an open-end spinning frame (hereinafter called open-end yarn) has a poorer texture than a fabric woven with yarn produced by a ring spinning frame (hereinafter called ring yarn). When fibers flown into the twisting area are wound around yarn that is being formed, the appearance of the yarn is deteriorated. Further, the open-end yarn has a lower strength than the ring yarn.
The present inventor thought that the poor texture of the manufactured fabric could be the result of the difference in structure between the open-end yarn and the ring yarn. The conventional open-end yarn has a prominent rough surface as if formed by twisting a ribbon or a tape, whereas the ring yarn has a relatively smooth outer surface. This may be because, in the conventional open-end spinning frame, as shown in FIG. 26, a fiber bundle F to be drawn to the guide hole (not shown) from a fiber-collecting section 72 of a rotor 71 is drawn from a separation point P almost vertically to the inner wall of the rotor 71. Because the angle θ between the fiber bundle F (yarn Y) at the separation point P and the inner wall of the rotor 71, or the twisting angle θ with respect to the fiber bundle F, is substantially 90 degrees, the fiber bundle F is bent by nearly 90 degrees so that tension is always applied to the outer fiber at the bent portion of the fiber bundle F while the inner fiber become slack. As the fiber bundle F is twisted under this condition, yarn is formed with fibers with lower tension wound around higher-tension fibers located at the center. As a result, the produced yarn becomes wavy and prominently shows a rough outer surface.
As a solution to the shortcoming of the conventional open-end yarn, another apparatus is disclosed in Japanese Unexamined Patent Publication No. 51-64034. This apparatus has a rotor having a fiber-collecting section or an outer rotor, and a draft rotor or an inner rotor, which is provided inside the outer rotor. This apparatus has a yarn drawing hole for drawing a fiber bundle collected at the collecting section and makes a differential rotation with respect to the outer rotor.
As shown in FIG. 27, this apparatus has an inner rotor 74 concentrically provided inside an outer rotor 73. The inner rotor 74 rotates slightly faster than the outer rotor 73 and the fiber bundle F is drawn through a yarn drawing hole 75 of the inner rotor 74. Accordingly, this apparatus spins out the fiber bundle F while drafting it. The aforementioned publication also discloses an apparatus that has a small disk 76, which is attached to the inner rotor 74 and revolves and rotates while being pressed against the fiber bundle F collected at the collecting section, as shown in FIG. 28(a). This apparatus spins out the fiber bundle F while drafting it with the floating of the fiber bundle F suppressed.
When the rotation speeds of both rotors 73 and 74 in the apparatus shown in FIG. 27 are relatively low, about 30,000 rpm, the fiber bundle F separated from the collecting section can be spun out along a gentle curve from the separation point P to the yarn drawing hole 75 as indicated by the solid line in FIG. 27. When the rotational speeds of the rotors become as fast as about 90,000 rpm, however, the fiber bundle F moving toward the yarn drawing hole 75 from the collecting section is stretched straight to very near the collecting section by the increased centrifugal force as indicated by the chain line. Consequently, the twisting angle becomes approximately 90 degrees, raising the above-discussed problem of the conventional open-end spinning frame having no inner rotor 74.
In the apparatus with the small disk 76 as shown in FIG. 28(a), it is possible to set the separation point P at a position immediately downstream of the position where the small disk 76 presses the fiber bundle F against the collecting section as shown in FIG. 28(a) by increasing the yarn drawing speed (winding speed) to increase the draft ratio when the rotational speed of the rotor becomes high. However, if the draft ratio is increased, the pressure by which the fiber bundle F contacts a point D of the end portion of the yarn drawing hole 75 raises so that twisting is hardly transmitted upstream from the point D, as shown in FIG. 28(b). This prevents the fibers collected at the collecting section from being drawn out. When the twisting force is increased to transmit twisting to the separation point P, bridge fibers Fb are produced between the inlet of the yarn drawing hole 75 and the point P and are wound around the fiber bundle F in a coil form. This yields so-called neck-wound fibers, which deteriorate the appearance of the yarn. This yarn reduces the texture quality of a fabric that is produced with the yarn.
When the pressure at which the small disk 76 contacts the outer rotor 73 is large, the inner rotor 74 causes the outer rotor 73 to rotate, making it difficult to rotate the inner rotor 74 and the outer rotor 73 with a predetermined speed difference. As the small disk 76 rotates while being in contact with the outer rotor 73, the small disk 76 or the outer rotor 73 is likely to wear.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a rotor type open-end spinning frame which can twist fibers constituting a fiber bundle that is to be drawn out while being twisted, into yarn while being stretched in a relatively straight fashion, thereby improving the texture of a fabric manufactured with this yarn. In addition, this can be accomplished at a high speed.
To achieve the above object, a rotor type open-end spinning unit has a collecting section collecting an opened and supplied fiber to make a fiber bundle. The fiber bundle is drawn through a yarn drawing passage to spin a yarn while twisting the fiber bundle. A rotatable outer rotor has an open-end, a closed end and a peripheral wall. The peripheral wall has the collecting section on an inner surface thereof. The collecting section is located in a plane normal to the rotational axis of the rotor. An inner rotor is located in the outer rotor and is driven independently. The inner rotor faces an end of the yarn drawing passage. A yarn path is provided with the inner rotor for guiding the fiber bundle from the collecting section to the yarn drawing passage. A first guide is provided with the inner rotor for contacting the fiber bundle guided to the yarn drawing passage through the yarn path from a frontward location with respect to the rotational direction of the inner rotor. A second guide is located frontward of the first guide and between the first guide and the inner surface of the outer rotor. The second guide guides the yarn toward the yarn drawing passage in cooperation with the first guide.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a partial cross-sectional view of a first embodiment of the present invention showing the relationship between an outer rotor and an inner rotor and the relationship between a support disk and a rotor shaft, as viewed from the opening side of the outer rotor;
FIG. 2 is a partial enlarged cross-sectional view of the outer rotor and inner rotor;
FIG. 3 is a partial cross-sectional view of an open-end spinning frame;
FIG. 4 is a partial enlarged cross-sectional view of a second embodiment;
FIG. 5 is a partial enlarged cross-sectional view of a third embodiment;
FIG. 6 is a partial enlarged cross-sectional view of a fourth embodiment;
FIGS. 7(a), 7(b) and 7(c) are partial cross-sectional views showing modifications in which a yarn passage is not located on the same plane as a yarn-collecting section;
FIG. 8 is a partial enlarged cross-sectional view of the outer rotor and inner rotor of a fifth embodiment;
FIG. 9 is a partial cross-sectional view of an open-end spinning frame according to the fifth embodiment;
FIG. 10 is a cross-sectional view taken along the line 10--10 in FIG. 8;
FIG. 11 is a partial enlarged cross-sectional view of a sixth embodiment;
FIG. 12 is a cross-sectional view taken along the line 12--12 in FIG. 11;
FIG. 13 is a partial enlarged cross-sectional view of a seventh embodiment;
FIG. 14 is a cross-sectional view taken along the line 14--14 in FIG. 13;
FIG. 15 is a partial cross-sectional view of an eighth embodiment;
FIG. 16 is a cross-sectional view taken along the line 16--16 in FIG. 15;
FIG. 17(a) is a partial enlarged cross-sectional view of a ninth embodiment, and FIG. 17(b) is an enlarged view of a vent hole;
FIG. 18 is a partial enlarged cross-sectional view of the ninth embodiment;
FIG. 19(a) is a partial enlarged cross-sectional view of a modification, and FIG. 19(b) is an enlarged view of a vent hole;
FIG. 20 is a partial enlarged cross-sectional view of this modification;
FIG. 21(a) is a partial cross-sectional view of another modification, and FIG. 21(b) is an enlarged view of a vent hole;
FIG. 22 is a partial enlarged cross-sectional view of this modification;
FIG. 23(a) is a partial enlarged cross-sectional view of a further modification, and FIG. 23(b) is an enlarged view of a vent hole;
FIG. 24 is a partial enlarged cross-sectional view of this modification;
FIG. 25 is a cross-sectional view of a still further modification;
FIG. 26 is an exemplary diagram showing the relationship between a drawn fiber bundle and a yarn-collecting section according to prior art;
FIG. 27 is a partial enlarged cross-sectional view of other prior art; and
FIG. 28(a) is a partial cut-away plan view of further prior art, and FIG. 28(b) is a partial enlarged view of the prior art of FIG. 28(a).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described referring to FIGS. 1 through 3. As shown in FIGS. 1 and 3, a pair of drive shafts 2 are supported parallel to each other, with a bearing 3 on a base 1 secured to a frame (not shown). Support disks 4 are fitted on both sides of each drive shaft 2 so as to be rotatable with that drive shaft 2. A pair of adjoining support disks 4 define a wedge-shaped recess 5, as shown in FIG. 1. A hollow rotor shaft 7 with an outer rotor 6 securely fitted on the distal end thereof is supported in the recess 5 in such a manner that the outer surface of the rotor shaft 7 contacts the individual support disks 4. A drive belt 8 common to a plurality of spindles is arranged between the two pairs of support disks 4 in a direction perpendicular to the rotor shaft 7 with the rotor shaft 7 pressed against the support disks 4. The drive belt 8 is driven by a drive motor (not shown), and the rotor shaft 7 rotates with running of the drive belt 8.
Bearings 9 are secured in large-diameter portions 7(a) formed at both ends of the rotor shaft 7, and a shaft 10 penetrating through the rotor shaft 7 is rotatably supported coaxial to the rotor shaft 7 via the bearings 9. The shaft 10 has a distal end on which an inner rotor 11 is rotatably fitted, and a proximal end abuts on a thrust bearing 12. A drive belt 13, provided common to a plurality of spindles, like the drive belt 8, is pressed against the shaft 10 so as to run in the direction perpendicular to the shaft 10. As the drive belt 13 runs, the shaft 10 rotates.
The thrust bearing 12 has a case 14 retaining a lubrication oil O, an oil supplying member 15 made of felt, a ball 16 rotatably supported on the oil supplying member 15, and an adjusting screw 15a which abuts on the ball 16 from the opposite side of the shaft 10. The support disks 4 are secured to the drive shafts 2 with slight inclination so that at the time the support disks 4 rotate in accordance with the rotation of the rotor shaft 7, a thrust load directed toward the thrust bearing 12 acts on the rotor shaft 7. The thrust load acting on the rotor shaft 7 is transmitted by the bearings 9 to the shaft 10 and is received by the thrust bearing 12.
A housing 17 is disposed to face the open side of the outer rotor 6, and a boss 18 is formed on the housing 17 so as to protrude inside the outer rotor 6. Bored in the boss 18 is one end of a fiber transport channel 22, which guides fibers, supplied by the actions of a feed roller 19 and a presser 20 and opened by a combing roller 21, into the outer rotor 6. A navel 24 in which one end of a yarn drawing passage 23 is bored is provided in the center of the boss 18. A yarn pipe 25, which constitutes a part of the yarn drawing passage 23, is laid so as to cross the center line of the navel 24, and its end portion 25a closer to the navel 24 of the yarn pipe 25 is a yarn (fiber bundle F) twist start point. A casing 26, which covers the outer rotor 6, abuts via an O-ring 27 on the end surface of the housing 17. The casing 26 is connected via a pipe 28 to a negative pressure source (not shown in FIG. 3).
The inner rotor 11 is designed so that part of its surface extends to the proximity of a fiber-collecting section 6a of the outer rotor 6, and has a recess 29 formed in the center portion of the inner rotor 11, in which the navel 24 is loosely fitted. The recess 29 also constitutes a part of a yarn passage 30. The radius of the largest outside-diameter portion of the inner rotor 11 is set larger than the radius of the inner wall of the opening of the outer rotor 6. A passage 30a is formed at the largest outside-diameter portion of the inner rotor 11, extending in the radial direction thereof. The passage 30a has one end open in the vicinity of the fiber-collecting section 6a of the outer rotor 6 and the other end open in the surface of the recess 29. The recess 29 and the passage 30a constitute the yarn path 30. The yarn path 30 is located on the plane where the collecting section 6a is positioned, and serves to guide the fiber bundle F from the vicinity of the collecting section 6a to the position at which it faces the yarn drawing passage 23.
As shown in FIGS. 1 and 2, a first guide 31 is disposed at the distal end of the inner rotor 11 in the proximity of the entrance of the yarn path 30, and is located on the forward side in the rotational direction of the inner rotor 11 with respect to the yarn path 30. The first guide 31 is formed in a substantially semi-cylindrical shape. The first guide 31 can contact the fiber bundle F, which is led to the yarn drawing passage 23 via the yarn path 30 from the forward or leading side (the right side in FIG. 1) with respect to the rotational direction (clockwise as viewed in FIG. 1) of the inner rotor 11. Formed opposite the first guide 31 is a wall 32 having a surface 32a which extends along the curved surface of the first guide 31. The distal end of the wall 32 is located forward of or leads the curved surface of the first guide 31 with respect to the rotational direction of the inner rotor 11, and this distal end forms a second guide 33. Therefore, the wall 32 inhibits fibers in the outer rotor 6 from entering the yarn path 30 downstream of the second guide 33, that is, from the rearward of lagging side with respect to the rotational direction of the inner rotor 11.
The inner rotor 11 is made of metal such as aluminum or aluminum alloy. The surfaces of both guides 31 and 33 and the wall 32 are subjected to plating, ion plating or the like, so that hard layer such as a chromium-plated layer or a titanium nitride layer, which has an excellent wear resistance, is formed.
The action of the thus structured spinning frame will now be described. In spinning mode, the drive belts 8 and 13 run in the same direction to rotate the outer rotor 6 and inner rotor 11 in the same direction via the rotor shaft 7 and the shaft 10. The rotational speed of the inner rotor 11, which is different from that of the outer rotor, is the speed of separation of the fiber bundle F from the fiber-collecting section 6a. This is slightly faster than the rotational speed of the outer rotor 6. In this state, the fibers, which have been opened by the action of the combing roller 21, are fed into the outer rotor 6 via the fiber transport channel 22 and slide along the inner wall of the outer rotor 6 to be collected at the collecting section 6a. The fiber bundle F collected at the collecting section 6a is linked to the yarn Y which is drawn via the yarn pipe 25 by the feed roller (not shown). As the yarn Y is drawn, therefore, the fiber bundle F is separated from the collecting section 6a, and is drawn while being twisted by the rotation of the inner rotor 11. Thus, the yarn Y is made longer. The twisting applied to the yarn Y and the fiber bundle F is transmitted to the collecting section 6a of the outer rotor 6 from the end portion 25a of the yarn pipe 25 as the starting point.
The fiber bundle F is drawn out at such a speed that the separation point P is set more forward with respect to the rotational direction of the inner rotor 11 than the second guide 33. The fiber bundle F separated from the collecting section 6a is introduced into the yarn path 30 while in contact with the second guide 33 and the first guide 31. More specifically, the fiber bundle F is drawn out on the forward side in the rotational direction of the inner rotor 11 while in contact with the arc surface of the first guide 31. Therefore, the angle between the direction of drawing the fiber bundle F at the separation point (twisting point) P and the fiber bundle F collected at the collecting section 6a, i.e., the twisting angle θ, becomes obtuse. The difference in passage between the inner fibers and outer fibers of the fiber bundle F, which is twisted while being separated from the collecting section 6a, becomes smaller, and the whole fiber bundle F is twisted with substantially uniform force with the fibers stretched almost straight. Consequently, it is less likely that the drawn-out yarn will have a rough surface. Consequently, a fabric produced with this yarn will have better texture.
When both rotors 6 and 11 rotate at a high speed, the centrifugal force acting on the fiber bundle F, which travels toward the first guide 31 from the separation point P, increases, thus increasing the force that presses the fiber bundle F toward the wall of the outer rotor 6. Because the second guide 33, located between the separation point P and the first guide 31, is positioned outward with the yarn path 30 in between, the movement of the fiber bundle F toward the wall of the outer rotor 6 is inhibited. Further, the rigidity of the fiber bundle F prevents the fiber bundle F from being bent after passing the second guide 33 to come in contact with the wall of the outer rotor 6. Even when both rotors 6 and 11 rotate at a high speed of about 90,000 rpm, the twisting angle θ of the fiber bundle F separated from the collecting section 6a is always held at an obtuse angle, unlike in the conventional apparatuses.
The yarn path 30 located downstream of the second guide 33 is provided with a wall 32 having a surface 32a, which extends along the curved surface of the first guide 31. Accordingly, the fiber bundle F, separated at the separation point P, positively moves in the yarn path 30 along the curved surface. With regard to the second guide 33, the presence of the wall 32 positively inhibits fibers from flying into the fiber bundle F on the rearward or lagging side of the guide 33, thus preventing the occurrence of neck-wound fibers.
A second embodiment will now be described with reference to FIG. 4. This embodiment differs from the first embodiment only in the structure of the first guide provided at the distal end of the inner rotor 11. Formed at the distal end of the inner rotor 11 is a retaining section 34, which makes the yarn path 30 open to the forward direction of or leading side of the inner rotor 11 and towards the opening of the outer rotor 6. A cylindrical pin 35, which constitutes the first guide, is secured in the retaining section 34 in such a way that a part of its outer surface faces the wall surface 32a. This surface 32a and the outer surface of the opposing pin 35 therefore constitute the first guide 31. The pin 35 is formed of a ceramic material, such as alumina, aluminum nitride (AlN), silicon carbide or boron nitride, which has an excellent wear resistance.
Both guides 31 and 33 and the wall 32 in this embodiment serve the same purposes as those of the first embodiment. Because the whole inner rotor 11 is formed integrally in the first embodiment, it is relatively troublesome to machine the surface 32a and the first guide 31. As the retaining section 34 is formed at the distal end of the inner rotor 11 in the second embodiment, however, the surface 32a can be worked after forming the retaining section 34, making the machining of the surface 32a easier. As the first guide 31 is constituted by the pin 35, the first guide 31 can be arranged at the desired position simply by securing the pin 35 to a predetermined position.
The first guide 31 through which the fiber bundle F passes with sliding contact is constituted by the ceramic pin 35. Therefore, the durability of the first guide 31 is improved, and when the first guide 31 is so worn after long use that it requires replacing, only the pin 35, not the entire inner rotor 11, needs to be replaced.
A third embodiment will be described below with reference to FIG. 5. This embodiment differs from the first embodiment only in the structures of the second guide 33 and the wall 32. The surface 32a of the wall 32 has a planar shape. Formed at the distal end of the inner rotor 11 is an opening portion 11a which opens towards the opening of the outer rotor 6. The second guide 33 is constituted by a ceramic pin, which is secured so as to contact the distal end of the wall 32 in the opening portion 11a.
Therefore, both guides 31 and 33 and the wall 32 in this embodiment also serve substantially the same purposes as those of the first embodiment. The second guide 33 through which the fiber bundle F passes with sliding contact is constituted by the ceramic pin, so that its durability is improved. Further, when the second guide 33 is so worn after long use that it requires replacing, only the pin, not the entire inner rotor 11, needs to be replaced.
A fourth embodiment will now be described with reference to FIG. 6. This embodiment differs from the second embodiment only in the structure of the first guide. A ceramic roller 36 is rotatably supported in the retaining section 34. The surface of the roller 36, which opposes the surface 32a, constitutes the first guide 31. Therefore, this embodiment exhibits the same action and advantages as the second embodiment, and has a reduced drawing resistance because of the rotation of the roller 36 in accordance with the movement of the fiber bundle F so that the first guide has a greater wear resistance.
In modifications illustrated in FIGS. 7(a) to 7(c), the yarn path 30 is located closer to the inside of the outer rotor 6 than to the plane where the collecting section 6a is present. In FIGS. 7(a) to 7(c), the top side is the opening side of the outer rotor 6.
The yarn path 30 is formed so as to correspond to the plane where the collecting section 6a is located in the embodiments of FIGS. 1-6. Thus, the fiber bundle F is drawn out straight toward the yarn path 30 along the plane where the collecting section 6a is located. The fibers supplied into the outer rotor 6 from the channel 22 slide toward the collecting section 6a on the inner wall (sliding wall) positioned closer to the opening of the outer rotor 6 than the collecting section 6a. If the fiber bundle F is drawn out straight toward the yarn path 30 from the collecting section 6a, therefore, the fibers that slide on the sliding wall, or the inner wall of the rotor 11, toward the collecting section 6a, may interfere with the fiber bundle F being drawn into the fiber bundle F (yarn Y). This will deteriorate the appearance of the yarn.
If the yarn path 30 is provided closer to the bottom of the outer rotor 6 than to the plane where the collecting section 6a is present, as in the illustrated modifications, the fiber bundle F slides on the inner wall of the outer rotor 6 to the position corresponding to the plane where the collecting section 6a is located, and is separated at the position away from the sliding wall. It is therefore less likely that the fibers sliding on the sliding wall will interfere with the fiber bundle F lying between the separation point P and the entrance of the yarn path 30.
In the modification shown in FIG. 7(a), the sliding portion of the fiber bundle F simply extends obliquely toward the inner wall 6b of the outer rotor 6. In the modification shown in FIG. 7(b), the sliding portion of the fiber bundle F has a shape substantially perpendicular to the inner wall 6b of the outer rotor 6. In the modification shown in FIG. 7(c), the sliding portion of the fiber bundle F extends in a direction substantially perpendicular to the inner wall 6b of the outer rotor 6 and then extends obliquely toward the inner wall 6b.
A fifth embodiment of this invention will be described below with reference to FIGS. 8 through 10. Like or same reference numerals as used for the above-described embodiments will be used to denote corresponding or identical components in this embodiment to avoid repeating their detailed descriptions.
The casing 26 is connected via the pipe 28 to a negative pressure source 134, which can adjust the level of the negative pressure which acts on the casing 26.
A recess 129 where the navel 24 is loosely fitted is formed in the center portion of the inner rotor 11 which faces the boss 18. The largest diameter portion of the inner rotor 11 has a path 130a located in the vicinity of the collecting section 6a of the outer rotor 6. Because an opening of the path 130a is provided on the plane where the collecting section 6a is present, it can serve to guide the fiber bundle F to the yarn drawing passage 23 from the vicinity of the collecting section 6a. The recess 129 and the path 130a comprise a yarn path 130.
As shown in FIG. 10, a first guide 131, which leads or is positioned forward of the inner rotor 11, is provided in the proximity of the path 130a of the inner rotor 11. This first guide 131, like the first guide 32 in FIG. 1, has a substantially semi-cylindrical shape. Therefore, the first guide 131 can contact the fiber bundle F (yarn Y), which is led to the yarn drawing passage 23, from the forward or leading side. A wall 132 having a surface 132a which extends along the curved surface of the first guide 131 is formed so as to confront the curved surface of the first guide 131. The distal end of the wall 132 leads or is forward of the curved surface of the first guide 131. This distal end forms a second guide 133.
Multiple vent holes 135 which permit the collecting section 6a to communicate with the outer surface of the outer rotor 6 are formed in the outer rotor 6 at predetermined pitches. The vent holes 135 extend in a direction perpendicular to the shaft 10.
When the outer rotor 6 and inner rotor 11 of this embodiment rotate, opened fibers are collected at the collecting section 6a to become a fiber bundle F as in the previously discussed embodiments. The fiber bundle F, which is linked to the yarn Y, is separated from the collecting section 6a in accordance with the drawing of the yarn Y, and is spun while being twisted. Twisting applied to the yarn Y and the fiber bundle F is transmitted to the collecting section 6a of the outer rotor 6 from the end portion 25a of the yarn pipe 25 as the starting point.
Since the vent holes 135 are so formed as to communicate with the bottom of the collecting section 6a of the outer rotor 6, an airstream directed outward of the outer rotor 6 from the collecting section 6a is generated in the vent holes 135 due to the self-exhausting action as the outer rotor 6 rotates fast. As the interior of the casing 26 is held in a reduced pressure state, an airstream directed outward of the outer rotor 6 is also generated in the vent holes 135 by the reduced pressure action. This airstream causes the fiber bundle F collected at the collecting section 6a to be pressed against the collecting section 6a.
Accordingly, the fiber bundle F is twisted at the separation point P while being firmly pressed against the collecting section 6a, thus suppressing the rotation of the fiber bundle F at the upstream of the separation point P. Thus, yarn having an excellent appearance is spun and a fabric produced with this yarn has a good texture. When the fibers which slide on the inner wall of the outer rotor 6 toward the collecting section 6a reach the collecting section 6a, the fibers are pressed on the collecting section 6a and restricted there by the aforementioned airstream. Even if the fiber bundle F at the upstream of the separation point P is twisted slightly, therefore, the fibers, before becoming a fiber bundle, are not loosely wound around the fiber bundle F in an unrestricted state, unlike in the prior art. This prevents a disturbance in the appearance of the produced yarn and prevents the deterioration of the texture of the resulting fabric. Since the fiber bundle F is pressed on the collecting section 6a by an airstream, the spinning frame of this embodiment has fewer components to wear out as compared with the apparatus that uses a roller or the like to mechanically press the fiber bundle F on the collecting section.
Both guides 131 and 133 and the wall 132 in this embodiment also serve the same purposes as those of the embodiments discussed previously.
By adjusting the negative pressure from the negative pressure source 134, the amount of air exhausted from the vent holes 135 is adjusted to change the force that presses the fiber bundle F on the collecting section 6a. It is therefore possible to apply an appropriate pressing force on the fiber bundle F by adjusting the negative pressure in accordance with the spinning conditions.
A sixth embodiment will now be described with reference to FIGS. 11 and 12. This embodiment differs from the above-described embodiments in the structures of the outer rotor 6 and inner rotor 11, but is the same as those embodiments in the remaining structure. As shown in FIGS. 11 and 12, an annular negative pressure chamber 136 (a negative pressure section) is formed in the outer rotor 6 outside the collecting section 6a. Multiple exhaust holes 137 are formed in, for example, the bottom of the negative pressure chamber 136 to connect this chamber 136 to the outside of the outer rotor 6. The outer rotor 6 comprises a body 6A and an annular portion 6B. The body 6A has the exhaust holes 137 in its bottom, and is fitted on the rotor shaft 7. The annular portion 6B has the collecting section 6a and is securely fitted on the body 6A by press fitting or the like. Multiple vent holes 135 are formed in the annular portion 6B so as to face the bottom of the collecting section 6a.
The inner rotor 11 is formed like a disk whose outside diameter is larger than the diameter of the collecting section 6a, so that the inner rotor 11 covers the exhaust holes 137 of the outer rotor 6. A cover 11a which faces the path 130a protrudes from the inner rotor 11 to cover the vent holes 135 from the negative pressure chamber side. In this embodiment, the cover 11a has such a length as to cover three vent holes 135 at a time.
While the spinning frame of this embodiment is running, air in the outer rotor is exhausted from the exhaust holes 137 based on the negative pressure in the casing 26, causing the negative pressure chamber 136 to have negative air pressure. As a result, an airstream which passes through the vent holes 135 from the collecting section 6a is generated to press the fiber bundle F at the collecting section 6aagainst this collecting section 6a. Accordingly, this embodiment performs the same action and has the same advantages as the above-discussed embodiments.
Because the vent holes 135 near the separation point P are covered with the cover 11a in this embodiment, the force that presses the fiber bundle F, separated from the collecting section 6a, on the collecting section 6a is lower and the drawing resistance of the fiber bundle F decreases. Consequently, the spinning becomes easier and this spinning frame is suitable particularly when soft twisting is performed, i.e. twisting is set low.
A seventh embodiment will now be described with reference to FIGS. 13 and 14. This embodiment differs from the sixth embodiment only in the shape of the inner rotor 11. A flange 138 which partly covers the exhaust holes 137 is formed in association with the bottom of the outer rotor 6. The flange 138 is so arranged as to reduce the clearance between the annular portion having the vent holes 135 and the collecting section 6a.
Accordingly, an airstream enters the negative pressure chamber 136 of the outer rotor 6 mainly from the vent holes 135 in accordance with the amount of air exhausted from the exhaust holes 137. The amount of exhausted air from the exhaust holes 137 is changed by changing the amount of coverage of the exhaust holes 137 by the flange 138 so that the pressing force on the fiber bundle F at the collecting section 6a can be changed by using the inner rotor 11, whose flange 138 has a different outside diameter. If inner rotors 11 with different outside diameters are prepared in association with the spinning conditions, therefore, even when the spinning frame is operated with the pressure in the negative pressure source 134 set constant, the pressing force that best matches the spinning conditions can be secured.
An eighth embodiment will now be described with reference to FIGS. 15 and 16. This embodiment differs from the sixth embodiment only in the shape of the inner rotor 11 and the shape of the vent holes 135. The inner rotor 11 is shaped in such a manner that the circumferential length of its maximum diameter portion is equal to the length of the cover 11a that covers the vent holes 135, and the inner rotor 11 is symmetrical with respect to the straight line that passes the center of the cover 11a and the rotational center of the inner rotor 11. The center of gravity of the inner rotor 11 coincides with the rotational center. The cover 11a is arranged rearward of or lagging the opening of the path 130a.
Each vent hole 135 has a circular cross section along its entire length, and is shaped in such a way that its diameter is the minimum on the collecting section (6a) side and gradually increases in the opposite direction. The minimum diameter portion of the vent hole 135 is set so as to permit the passing of dust such as short fibers unfit to form yarn, waste leaves or waste seeds, and restricts the passing of fibers effective to form yarn. The minimum diameter portion of the vent hole 135 should be almost 1 mm or less, preferably about 0.5 mm. This diameter differs depending on the operation conditions. When this diameter is greater than 1 mm, too many effective fibers are undesirably discharged. When the diameter is smaller than 0.5 mm, dust is not discharged, making clogging easier.
In addition to the same action and advantages as the sixth embodiment, therefore, this embodiment has such a feature to suppress the occurrence of clogging when dust such as short fibers unfit to form yarn, waste leaves or waste seeds, which have been supplied with the proper fibers into the outer rotor, are discharged from the vent holes 135. With vent holes 135 having a constant diameter, when the size of dust which has entered the vent holes 135 is close to the size of the vent holes 135, the dust may cause clogging midway in each vent hole 135. According to this embodiment, however, each vent hole 135 gradually becomes larger toward the exit from the entrance, i.e., from the collecting section (6a) side, so that the dust having entered the vent hole 135 smoothly moves toward the exit and will not cause clogging.
A ninth embodiment will now be described with reference to FIGS. 17 and 18. This embodiment differs from the seventh embodiment only in the shape of the vent holes 135. As shown in FIG. 17B, each vent hole 135 has a small diameter portion 135a and a tapered portion 135b extending from the small diameter portion 135a that is provided on the collecting section (6a) side. The small diameter portion 135a has a uniform inside diameter which is set equal to the diameter of the minimum diameter portion of the vent holes 135 of the eighth embodiment. The tapered portion 135b is formed in such a way that its inside diameter gradually increases toward the exit.
This embodiment therefore has a feature to suppress the occurrence of clogging when dust which has been supplied with the proper fibers into the outer rotor, is discharged from the vent holes 135. In addition, this embodiment exhibits the same action and advantages as the sixth embodiment.
This invention may be embodied in the following forms:
The entire inner rotor 11 may be formed of ceramics. In this case, wearing of the first guide 31 and second guide 33 is reduced to improve durability. When the entire inner rotor 11 is formed of ceramics, desirable ceramic materials include alumina, aluminum nitride (AlN), silicon carbide or boron nitride, which have excellent wear resistance.
In the second to fourth embodiments, both of the first guide 31 and second guide 33 may be formed of ceramics. In this case, both guides 31 and 33 have an improved durability and are easy to replace. In the fifth to ninth embodiments, only the first guide 131 and second guide 133 may be formed of ceramics. In this case, the first guide 131 and the second guide 133 experience reduced wearing and have an improved durability. Further, when the spinning frame is so worn after long use that it requires replacing, both guides 131 and 133 need only to be replaced. No replacement of the entire inner rotor 11 is required.
The second guide 33 or 133 may be structured to protrude alone, without the wall 32 or 132, which be accomplished by eliminating the wall 32 in FIG. 5. In this case too, the fiber bundle F separated at the separation point P does not contact the inner wall of the outer rotor 6, even when the centrifugal force acts on the fiber bundle F, so that the fiber bundle F is guided to the first guide while the twisting angle is kept obtuse.
The entire inner rotor 11 may be formed symmetric with respect to the rotational axis by providing an extending portion having substantially the same shape as the portion where the yarn path is formed, on the opposite side of the inner rotor 11 to the yarn and by extending the extending portion to the vicinity of the collecting section 6a.
This invention may also be embodied in the following forms.
The intensity of the forced exhaustion may be set in accordance with the spinning conditions based on the relation between the intensity of the forced exhaustion or the power of the negative pressure source 134 and the pressing force acting on the fiber bundle F at the collecting section 6a, which has been previously determined through test spinning.
The number and size of vent holes 135 and the pitch between the vent holes 135 may be changed as needed. Further, the number and size of exhaust holes 137 and the pitch between the exhaust holes 137 may be changed as needed. When the power of the negative pressure source 134 is set constant, the level of the negative pressure from the negative pressure chamber 136 can be adjusted by changing the number and/or size of the exhaust holes 137.
The cover 11a formed on the inner rotor 11 in the sixth embodiment may be formed so as to cover the vent holes 135 which are positioned in the vicinity of the opening for the introduction of the fiber bundle excluding the portion located on the forward side in the rotational direction of the inner rotor 11. In this case, because an airstream flows to the negative pressure chamber 136 mainly from the vent holes 135 near the separation point P, the pressing force on the fiber bundle F near the separation point P becomes stronger even when the power of the negative pressure source 134 and the number of rotations of the inner rotor 11 are the same.
In the ninth embodiment, the portion of the inner rotor 11, which is opposite to where the path 130a of the inner rotor 11 is formed, may be formed to extend to the vicinity of the collecting section 6a so that the entire inner rotor 11 is formed symmetrical with respect to the rotational axis or is formed in a disk shape. That is, the inner rotor 11 may take any shape as long as the dynamic balance can be maintained.
As shown in FIGS. 19(a), 19(b) and 20, each vent hole 135 in the eighth embodiment may include a tapered portion 135b provided on the collecting section (6a) side and a large diameter portion 135c extending from the tapered portion 135b. The minimum diameter of the tapered portion 135b is set the same as the minimum diameter of the vent hole 135. Dust can be smoothly discharged from the vent holes 135 in this case.
As shown in FIGS. 21(a), 21(b) and 22, each vent hole 135 in the ninth embodiment may be constituted by a small diameter portion 135a provided on the collecting section (6a) side, a tapered portion 135b and a large diameter portion 135c. Dust can be smoothly discharged from the vent holes 135 in this case.
The cross-sectional shape of the vent hole 135 may take other shapes than the circular shape, or may consist of a circular cross-sectional portion and a portion of another shape. As shown in FIGS. 23(a), 23(b) and 24, for example, the vent hole 135 may be constituted by an elongated groove 135d, which has a rectangular cross section and is provided on the collecting section (6a) side to extend perpendicular to the collecting section 6a, and a large diameter portion 135c whose diameter is greater than the width of the groove 135d or the length thereof along the extending direction of the collecting section 6a. Dust can be smoothly discharged from the vent holes 135 in this case. FIG. 24 is a partly enlarged view showing around the collecting section 6a of the outer rotor 6.
In the above-described embodiments and modifications, the vent holes 135 may be formed, not radially, but in such a way that the exit of the vent hole located opposite to the collecting section extends in the direction opposite to the rotational direction of the outer rotor 6 with respect to the entrance. In this case, the amount of air moving toward the negative pressure chamber 136 from the vent holes 135 increases. The vent holes 135 may be formed so as to obliquely extend toward the opening side or the bottom of the outer rotor 6, not on the plane perpendicular to the shaft 10.
The fiber-bundle introducing opening 130 which leads the fiber bundle F, collected at the collecting section 6a, to the yarn drawing passage 23 is not limited to the passage that continuously extends to the yarn drawing passage 23, but should only have a portion for guiding the fiber bundle F to the vicinity of the collecting section 6a. As shown in FIG. 25, for example, the inner rotor 11 may be provided with the first guide 131 and second guide 133, with open space S being defined between the first guide 131 and the yarn drawing passage 23.
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.
|
A rotor type open-end spinning unit has a collecting section collecting an opened and supplied fiber to make a fiber bundle. The fiber bundle is drawn through a yarn drawing passage to spin a yarn while twisting the fiber bundle. A rotatable outer rotor has an open end, a closed end and a peripheral wall. The peripheral wall has the collecting section on an inner surface thereof. The collecting section is located on a plane perpendicular to the rotational axis of the rotor. An inner rotor is located in the outer rotor and is driven independently. The inner rotor faces an end of the yarn drawing passage. A yarn path is provided with the inner rotor for guiding the fiber bundle from the collecting section to the yarn drawing passage. A first guide is provided with the inner rotor for contacting the fiber bundle guided to the yarn drawing passage through the yarn path from a frontward location with respect to the rotational direction of the inner rotor. A second guide is located frontward of the first guide and between the first guide and the inner surface of the outer rotor. The second guide guides the yarn toward the yarn drawing passage in cooperation with the first guide.
| 3
|
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection pump for internal combustion engines, which includes a cam drive for actuating at least one pump piston and an injection adjusting or timing mechanism.
The German patent publication No. DE-OS 27 29 807 (U.S. Pat. No. 4,177,775) discloses a fuel injection pump in which the adjustment of the injection start to "early" is obtained for a cold engine and a warmed-up engine with the aid of a thermostat which is applied against the force of the restoring spring on the adjusting lever. The stop provided in the adjustment device acts in a recess formed in a roller ring, on which the rollers are uniformly distributed and on which a cam disc runs, which is interconnected between the drive and the pump piston. The shaft, with which the stop of the adjustment device is in connection, is supported in the known fuel injection pump in a sleeve bearing. The lever arm is positioned in the operative position between the stop and the axis with which the stop is adjusted somewhat perpendicular to the direction of adjustment of the roller ring so that a high torque is required for the adjustment. Considerable displacement forces which act in the known adjustment device must be overcome.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved fuel injection pump.
This and other objects of this invention are attained by a fuel injection pump for internal combustion engines, comprising a housing; a cam drive including at least one roller running on a circular cam track, a pump piston, said cam drive effecting a conveying stroke of said pump piston, said cam drive including one portion which carries said at least one roller and is rotated by a drive of fuel injection pump, and another portion which is stationary in a direction of a cam elevation and is ring-shaped in a direction of a cam track circumference, said housing including a circular recess in which said another portion is positioned; an adjustment mechanism adapted to be rotated relative to said another portion for changing an injection start, said another portion being formed with a recess, said adjustment mechanism including an adjusting lever, a shaft positioned in said housing and connected to said lever and having an axis, and a stop engaged in the recess of said another portion and connected to said shaft, said stop being arranged eccentrically to said axis to form a lever arm, said adjustment mechanism further including an injection adjustment piston connected to said another portion of the cam drive and adjustable in dependence on the speed of the pump; said adjustment mechanism further including a sleeve having a bore, a roller bearing positioned in said bore and supporting said shaft, said housing having a wall formed with a circular recess, said sleeve having a cylindrical portion received in the circular recess of said wall, said cylindrical portion having an axis extending eccentrically with the axis of the shaft, fixing means for connecting said sleeve to the wall of said housing in a respective rotational position of the sleeve, at least one limiting stop member which defines such a rotational position of said shaft in which said lever arm is in alignment with a circumferential direction of said another portion of said cam drive.
The roller bearing may be a needle bearing which has an outer ring pressed in said sleeve, said shaft forming an inner ring of said needle bearing.
The sleeve may have a flange formed with oblong openings, said fixing means including bolts which are guided through said oblong openings, said bolts fixing said sleeve in said housing in an adjusted rotation position.
The pump may further include a plate formed with said limiting stop member, said plate being connected to said limiting stop member limiting at least one end position of said adjusting lever.
The plate may be mounted to the flange of said sleeve and is held on said flange by said bolts.
The chief advantage of the present invention resides in that the friction forces and restoring torques which act on the adjusting lever are substantially reduced as compared to those occurring in the conventional fuel injection pump. The restoring torques are specifically reduced due to the selection of the adjustment region of the stop which has only a very small lever arm acting in the restoring direction and which becomes ever smaller the closer it approaches its top dead center. The rotation of the stop up to its top dead center relative to the direction of adjustment of the aforementioned another portion of the cam drive (for example, cam ring) has the advantage that in this position the smallest holding forces are sufficient to maintain this adjustment position. Therefore a compensation for tolerances or the adjustability, by a turnability of the sleeve guiding the shaft and an eccentric support of the shaft relative to the axis of the sleeve, are possible in a simple fashion. The adjustment position can be easily and accurately controlled by the cooperation of the sleeve with one of the limiting stop members.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the amount of adjustment according to a number of revolutions;
FIG. 2 is a cross-sectional view of the injection pump;
FIG. 3 is a top plan view of the adjusting lever; and
FIG. 4 is a side view of the roller ring shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is known, the start of ignition of fuel into a Diesel engine and a further ignition process at pressure surges in a combustion chamber are determined in the region of the top dead center of the piston of the engine. In order to avoid high combustion noises the feed of fuel must be conducted so that a relatively uniform burning out of the mixture would take place in such a manner that no great peaks of pressure would occur before the dead center. The control of the injection time point at the delay of the ignition and the time of the ignition, which are required for the fuel to be ignited and burned out, must be taken into consideration. The ignition delay, as is known, depends upon temperatures of the fuel itself and also upon the temperature conditions of the environment. Since these times are practically constant the injection time point is shifted to "early" when the number of revolutions of the Diesel internal combustion engine is increased. Inasmuch as the ignition delay, specifically in a cold internal combustion engine, is very long it has been advantageous to shift the injection start to "early" already during the start-up of the internal combustion engine and at the low number of revolutions. This "early" injection point in time would cause a shifting forward of a combustion peak pressure in the warmed-up internal combustion engine before the top dead point is reached, which, as is known, has some disadvantages. The shifting of time point to "early" is favorable for the start in order to obtain a fast running-up of the internal combustion engine.
FIG. 1 of the drawings shows the relationship between the adjustment amounts and the speed of the machine. The injection adjustment angle α is plotted over the ordinate, and the speed is plotted over the abscissa. The curve S linearly rises as the number of revolutions is increased from n 1 to n 2 . Characteristic S 1 for the injection adjustment shows that angle α 1 in the region of the warmed-up running remains constant over a number of revolutions unless it reaches a point of intersection with the curve S, at which the injection adjustment angle α is adjusted to "early" at the increased number of revolutions. Curve S corresponds to the injection adjustment at normal operating temperature of the internal combustion engine whereas curve S 1 corresponds to the adjustment of the injection time point to "early" independently from the number of revolutions of the pump, which can be obtained by the arrangement according to the invention.
The fuel injection pump, with which the above described curve can be realized is illustrated in FIG. 2. FIG. 2 shows a partial sectional view through a distributor fuel injection pump in the region of the cam drive 1 and the injection adjustment mechanism 2. Only a housing 3 of the cam drive is partially shown in the drawing. A roller ring 4 is radially and axially guided in housing 3. Rollers 7 are positioned at a front side of the roller ring 4 in the known fashion. Axles 6 of rollers 7 are respectively inserted in an inner and outer ring of the roller ring 4. An adjusting pin 5 radially outwardly projects from the roller ring 4 and is connected thereto. The end of the adjusting pin 5 is received in a recess 8 of an injection adjusting piston 9 of the injection adjustment mechanism 2. The adjusting piston 9 is displaceable in a bore 13 of the adjustment mechanism 2. Bore 13 is enclosed at two sides by covers 14 and 15. The adjusting piston 9 has a work chamber 16 at one side of bore 13. Work chamber 16 is in communication with recess 8 through a throttle 12 formed in the adjusting piston 9 and with a pump suction chamber 17 through the recess 8. The pump suction chamber 17 is filled in the known fashion with fuel, the pressure of which depends on the number of revolutions of the pump but can be adjusted in dependence upon other parameters.
A restoring spring 10 is provided on the other side of adjusting piston 9 between the cover 15 and the front side of the piston. A hydraulic pressure of the fuel in the work chamber 16 acts against the restoring force of spring 10. As the number of revolutions of the pump increases the adjusting piston 9 is adjusted in the leftward direction and the roller ring is rotated against the direction indicated by the arrow or leftwardly.
The arrow in the drawing shows the direction of rotation of the cam disc (not shown) which runs on rollers 7; the cam disc is connected in the known fashion to the pump piston and is driven by the drive of the fuel injection pump synchronously with the number of revolutions of the internal combustion engine. If the roller ring 4 is rotated further in the left-hand direction then, the sooner the cams of the cam disc run on the roller 7 the sooner the feeding stroke of the pump piston and the injection start therewith will result.
A recess 19 is further provided in the roller ring 4, namely in its outer ring 20. This recess is also seen in FIG. 4. In the exemplified embodiment recess 19 is rectangular in shape. A stop 22 having the shape of a ball-like head extends into the recess 19. A disc or washer 23, which forms the end portion of a shaft 24, is connected to the stop 22. The diameter of disc 23 is greater than the diameter of shaft 24 and stop 22 is positioned axially eccentrically to central axis 25 of shaft 24 so that the eccentricity indicated by "e" forms a crank arm.
Shaft 25 is immediately supported on the rollers or needles of a needle bearing 26 and forms in a way an inner ring of the needle bearing 26. The latter is inserted, for example pressed, in a bore 27 of a sleeve 28 which has a flange 29 formed with two diametrally opposing oblong holes 30, through which fastening bolts 31 extend. Fastening bolts 31 guided in respective oblong holes 30 are screwed into housing 3 of the fuel injection pump. Sleeve 28 further has a cylindrical portion 32 which is inserted into a cylindrical recess 33 formed in the pump housing. The central axis of recess 33 is parallel to that of bore 27 but these recesses are formed with a predetermined eccentricity.
An adjusting lever 35 is secured on the end of shaft 24, extended outwardly from sleeve 28. Adjusting lever 35 together with the disc or washer 23 with the interposition of a protection washer 36 between the washer 23 and needle bearing 26 axially secures shaft 24. A plate-like element 38 is mounted to the flange 29 of sleeve 28. Plate 38 has two diametrally opposing bores, as shown in FIG. 3, through which fastening bolts 31 are guided. The plate-like element 38 is secured in its angular rotation position by means of the fastening bolts 31. This element 31 has two projecting lugs which form limiting stops 39 and 40, into contact with which adjusting lever 35 can be brought.
The operation of the fuel injection pump according to the invention is as follows:
The adjustment of the injection time point is obtained by means of the injection time adjustment mechanism 2 in dependence upon the number of revolutions of the pump and thus the engine in accordance with curve S depicted in FIG. 1. If the engine is cold the lever 35 is rotated by the hand of the operator to the left and is brought into contact with the limiting stop 39 as shown in dash-dotted line in FIG. 3. The stop 22 is thereby also adjusted and moves to the position shown by dashed line in FIG. 4. In this position the point of contact 41 of stop 22 with the limiting edge 42 lying in the circumferential direction of roller ring 4 is in alignment with the central axis 25 in the circumferential direction or the direction of rotation of roller ring 4. In this position the restoring spring 10 of the injection adjustment mechanism 2 exerts no torque on shaft 24 so that the holding forces on adjusting lever 35 for the maintenance of this position of stop 22 are practically zero. This position now defines, however an earlier point in time of injection α 1 in accordance with S 1 in FIG. 1 unless the number of revolutions of the internal combustion engine increases such that the injection adjusting piston 9 assumes the adjustment position at the point of intersection of curves S 1 and S when the number of revolutions of the engine is n 2 . At this point the adjustment of the start of the ignition takes place in a usual manner. When the internal combustion engine is warmed-up the adjusting lever 35 is rotated in the counter direction back and the stop 22 is also pivoted in the backward direction. Then even smaller injection adjustment angles α are possible during the running of the engine in accordance with curve S.
Owing to the above-described fashion of the adjustment of the onset of the ignition the adjustment to "early" can be conducted easily by an operator of the engine and without the requirement of servo-control or complicated lever transmission arrangements. Friction forces which act against the rotation of shaft 24 are substantially reduced due to the supporting of the shaft on the roller or needle bearings, and further the lever arm "e" is held very small so that the stop in its position at the top dead center, which causes the "early" adjustment of the internal combustion engine in case of a cold engine, and of the warmed-up engine as well, is in relation with the direction of the adjustment of the roller ring. The effective lever arm "e" is further reduced within a small operative rotation range of shaft 24 of about 50° so that the stop travels along a circular path shortly before the top dead center, and a change in a rotation angle produces only a very small stroke.
Since in the arrangement according to the present invention the position of the dead center of stop 22 is provided as an end position the adjustment of the whole shaft 24 is necessary, which is possible due to its eccentric position relative to the cylindrical portion 32 of sleeve 28. This sleeve is adjusted along the oblong openings 30 after bolts 31 have been loosened, and sleeve 28 can be then fixed in a desired end position by bolts 31. The adjusting lever 35 is mounted on the end of shaft 24 by means of a toothing 43 and is held on that end by a nut 44. The coordination of adjusting lever 35 with the stop lug 39 can be adjusted by means of toothing 43. Thereby an accurate adjustment is ensured. The actuation of the adjusting lever can be obtained by a pulling cable, whereby no locking device in the work position of the adjusting lever is necessary for the aforementioned reasons.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of fuel injection pumps for internal combustion engines differing from the types described above.
While the invention has been illustrated and described as embodied in a fuel rejection pump for an internal combustion engine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
|
A fuel injection pump is provided with a device for adjusting the start of fuel injection which includes a turnable roller ring and a stop engaged in the roller ring and mounted on a shaft turnable by an actuating adjusting lever between two end positions. The stop is positioned eccentrically to the axis of the shaft. The stop limits the angle of twist of the roller ring to adjust the start of fuel injection.
| 5
|
FIELD
[0001] The present disclosure relates to fluid tight seal structures and more particularly to fluid tight seals for installation between a drive motor housing and a housing of an automatic transmission.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
[0003] Modern passenger car and truck hybrid automatic transmissions frequently employ high torque electric motors to act as the sole energy source in certain operational modes and to operate in conjunction with a gasoline, Diesel or flexible fuel engine in other operational modes. Because these electric motors generate significant mechanical power for lengthy periods of time while consuming corresponding quantities of electrical power, they generate significant amounts of heat. In order to maintain a suitable, low operating temperature, it is necessary to remove such heat, typically by circulation of a heat transfer medium around the motor housing. Given the availability of transmission fluid, its system for circulation and heat rejection and its acknowledged heat transfer function, it is the obvious general solution to this requirement.
[0004] Because of the presence of pressurized or unpressurized moving fluid nearly everywhere within an automatic transmission, a first solution might appear to be simply exposing the motors to fluid circulating in the transmission. In reality, such fluid circulation at any given location within the transmission may vary widely depending upon the current operating state of the transmission and compromise cooling of the motor under certain conditions. It is thus apparent that a controlled, dedicated flow of transmission fluid to cool the motor is desirable.
[0005] However, due to the importance of maintaining relatively cool motor temperatures under all operating conditions with large motors occupying much or all of the transmission cross section, and the need to both positively provide fluid flow and control the volume of fluid flow, the choice to utilize a dedicated flow of transmission fluid for cooling creates a new array of engineering challenges. A first challenge relates to the fact that the motors may occupy all or a significant portion of the cross section of the transmission. This creates difficulties relating to fluid distribution to and within the motor. One solution to this challenge is to provide pressurized fluid to an annular passageway disposed between the motor housing and the inside of the transmission housing. Radial ports in the motor housing direct fluid to motor components such as the windings to absorb and carry away heat. A related challenge involves providing a secure, fluid tight seal between the transmission housing and motor housing so that a consistent, controlled flow of transmission fluid through the motor and its windings can be achieved.
[0006] One prior art approach to achieving a seal between a transmission and a drive motor housing utilizes O-rings disposed in channels extending about the circumference of the motor housing that engage complementarily located and configured circular shoulders or surfaces in the transmission housing. While this arrangement provides an acceptable seal, it is subject to assembly variations. For example, since the O-rings are installed on the outside of the motor housing, they are subject to being accidentally dislodged before or during mounting of the motor. Additionally, if an O-ring comes in contact with, for example, a sharp edge of the transmission housing during mounting of the motor, minor and possibly undetected damage to the O-ring can occur, resulting in initial or premature seal failure. Additionally, verification that the O-ring is assembled is very difficult due to its small size relative to the motor assembly. This precludes use of a vision system to ensure the O-ring is in place prior to assembly into the main housing.
[0007] From the foregoing brief review of the prior art of drive motor/transmission seal technology, it is apparent that improvements to this art are desirable.
SUMMARY
[0008] The present invention provides an improved seal between the housing of an automatic transmission and the housing (can) of a transmission drive motor. The seal, one of which is disposed at each end of the drive motor housing, includes a metal annulus having inner and outer elastomeric ribbed seals bonded thereto. The metal annulus, which defines a non-hardened “S” shape in cross section, maintains the shape and strength of the seal and the ribbed inner seal provides a fluid tight seal against the motor housing while the ribbed outer seal provides a fluid tight seal against the transmission housing. In pre-assembly configuration, rather than being installed on the outside of the motor housing, the motor seals according to the present invention are installed into the transmission housing where they are protected against damage and the drive motor is then installed into the transmission. The motor housing seal according to the present invention provides improved ease and certainty of correct installation as well as reduced likelihood of damage to the seal during installation, thereby reducing subsequent failures and service.
[0009] Thus it is an object of the present invention to provide a seal for disposition between the housing of an electric motor and the housing of an automatic transmission.
[0010] It is a further object of the present invention to provide a seal for disposition between the outside of a housing of an electric motor and the inside of a housing of an automatic transmission.
[0011] It is a still further object of the present invention to provide an annular seal for disposition between the housing of an electric motor and the housing of an automatic transmission having a metal ring and resilient sealing portions bonded to the ring.
[0012] It is a still further object of the present invention to provide a seal for disposition between the housing of an electric motor and the housing of an automatic transmission having a metal ring and resilient ribbed portions bonded to the ring.
[0013] It is a still further object of the present invention to provide an annular seal for disposition between the outside of a housing of an electric motor and the inside of a housing of an automatic transmission having a metal ring and resilient ribbed portions bonded to the ring.
[0014] Further objects, advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0015] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0016] FIG. 1 is a fragmentary, side elevational view of an automatic transmission incorporating the present invention,
[0017] FIG. 2 is a perspective view of an electric motor housing having front and rear seals according to the present invention;
[0018] FIG. 3 is an enlarged, side elevational view of a electric drive motor housing for an automatic transmission having front and rear seals according to the present invention; and
[0019] FIG. 4 is an enlarged perspective view of a control motor housing and seal according to the present invention.
DETAILED DESCRIPTION
[0020] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
[0021] With reference to FIG. 1 , a portion of an automatic vehicular transmission is illustrated and designated by the reference number 10 . The automatic transmission 10 includes a typically cast, metal housing 12 that supports, positions and protects various internal components such as an input shaft (not illustrated), a main output shaft 14 , one or more planetary gear assemblies 16 (one of which is illustrated), a plurality of electrical feed-throughs or connectors 18 (one of which is illustrated), an electric motor assembly 20 and a hydraulic vane or gerotor pump (not illustrated). It will be appreciated that although only one electric motor assembly 20 is illustrated in the automatic transmission 10 , more than one may be incorporated therein and the present invention is equally suitable for use with additional electric motor assemblies.
[0022] Referring now to FIGS. 1 and 2 , the electric motor assembly 20 includes a generally tubular or cylindrical housing 22 which encircles a stator 24 having electrical field windings 26 . Rotatably disposed within the housing 22 and the stator 24 is a rotor 28 which is supported upon a pair of anti-friction support devices such as ball bearing assemblies 30 . The ball bearing assemblies are, in turn, supported on a tubular member or bearing support 32 which is connected with a welded joint to the cylindrical motor housing 22 . The rotor 28 is coupled to the main shaft 14 by an internally and externally splined hub 34 or similar component.
[0023] The cylindrical motor housing 22 includes a plurality of radially oriented lubrication passageways or apertures 36 arranged in front and rear circumferential arrays at the upper portion of the housing 22 . The cylindrical motor housing 22 also includes two or more locating tabs or projections 38 that engage complementarily arranged slots or recesses (not illustrated) within the automatic transmission 10 . The slots and projections 38 are dimensionally related to ensure that the cylindrical motor housing 22 is oriented properly, that is, with the lubrication passageways or apertures 36 at the top of the automatic transmission 10 when it is installed therein.
[0024] Referring now to FIGS. 2 and 3 , about the outer surface of the motor housing 22 are disposed a pair of seals 40 according to the present invention. A front or first seal 40 A is located along a front or first edge of the cylindrical motor housing 22 outside the lubrication passageways 36 and a second or rear seal 40 B is located along a second or rear edge of the cylindrical motor housing 22 also outside the lubrication passageways 36 . Stated somewhat differently, the lubrication passageways or apertures 36 reside in an (axial) region between the front seal 40 A and the rear seal 40 B.
[0025] Referring now to FIGS. 3 and 4 , it should be appreciated that but for their distinct diameters, the front seal 40 A and the rear seal 40 B have an identical cross-section. Thus, in FIG. 4 , only the front seal 40 A is illustrated as the description applies with equal accuracy to the rear seal 40 B. The front seal 40 A includes a center metal band or annulus 42 that is formed into a non-hardened “S” shape having a first end 44 that is curved or formed inwardly at a right angle (90°) such that the first end face 46 of the annulus 42 is parallel to the axis of the cylindrical housing 22 and extends inwardly from the inner surface 48 of the annulus 42 . The other or second end 50 of the annulus 42 is curved or formed outwardly such that the second end face 52 is also parallel to the axis of the cylindrical housing 22 but is substantially flush or co-planar with the outer surface 54 of the annulus 42 . The shape of the metal band or annulus 42 in the seal 40 A provides rigidity and dimensional stability to the seal 40 A
[0026] Molded in-situ or bonded to the inner surface 48 of the annulus 42 by any suitable bonding or fastening technique is a first resilient internal seal 62 of, for example, an elastomeric material having two or more ribs 64 which contact and seal against the outside of the cylindrical motor housing 22 . Molded in-situ or bonded to the outer surface 54 of the annulus 42 by any suitable bonding or fastening technique is a second resilient internal seal 66 also of, for example, an elastomeric material having three or more ribs 68 which contact and seal against the inside surface of the transmission housing 12 .
[0027] Inspection of FIG. 3 reveals that the seals 40 A and 40 B are oriented with the first end surfaces 46 and the first end faces 46 of the metal bands 42 remote from the open end of the cylindrical motor housing 22 and the second end surfaces 52 of the metal bands 42 nearer the open end of the cylindrical motor housing 22 . Inspection of FIG. 4 reveals that the first end face 46 of the annulus 42 is preferably exposed because the bonding process requires a non-sealed portion of the metal band 42 for gating processes during fabrication and will assist properly locating the motor housing 22 whereas the second end face 52 of the annulus 42 is preferably covered or encased by a thin layer of the elastomeric material to ensure proper bonding of the elastomeric material to the metal band 42 .
[0028] Returning to FIG. 1 , It will be appreciated that the front seal 40 A and the rear seal 40 B define an annular cavity or region 70 that extends circumferentially about the motor housing 22 between it and the inside surface of the transmission housing 12 . This circumferential region 70 is pressurized by the hydraulic pump of the automatic transmission 10 and hydraulic fluid flows into the circumferential region 70 at low pressure, through the lubrication passageways or apertures 36 and is directed by the apertures 36 and contacts the motor windings 26 . Heat generated in the motor windings 26 is carried away by the hydraulic fluid and rejected to the atmosphere through a transmission fluid cooler (not illustrated).
[0029] The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention or the following claims.
|
A seal for use between the housing of an automatic transmission and the housing (can) of a transmission drive motor is disposed at each end of the drive motor housing. The seal includes a preferably metal annulus having inner and outer elastomeric ribbed seals secured thereto. The annulus, which defines a non-hardened “S” shape in cross section, maintains the shape and strength of the seal and the ribbed inner seal provides a fluid tight seal with the motor housing while the ribbed outer seal provides a fluid tight seal with the transmission housing.
| 5
|
The invention herein described was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457).
The invention relates to nacelles for gas turbine aircraft engines and, particularly, to cowls for contrarotating fans.
BACKGROUND OF THE INVENTION
FIG. 1 illustrates an aircraft 13 and a propulsion system 15 with which the invention may be used. Two sets of fan blades 10A and 10F rotate in opposite directions as indicated by arrows 13A and 13F, providing thrust, indicated by arrow 16. A nacelle 18 surrounds the engine (not shown) and defines a flow path along which freestream air 19 travels during flight. Rotating nacelle sub-regions (or cowls) 20A and 20F define the flow paths near fan blade roots.
A schematic cross section of region 22 is shown in FIG. 2. This region contains rotating turbo machinery 25 located within cowls 20A and 20F. It is desirable that maintenance personnel have easy access to the machinery contained within cowls 20A and 20F, such as fan blade mounts indicated as 27 (not shown in detail).
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an improved aircraft engine nacelle.
It is a further object of the present invention to provide a rotating cowling for use with a fan-powered aircraft engine.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates an aircraft powered by counterrotating unducted fans with which the invention can be used.
FIG. 2 illustrates in schematic form a counterrotating turbine for driving the unducted fans.
FIG. 3 illustrates one form of the invention.
FIG. 4 illustrates one of the turbine stages in the turbine shown in FIG. 2.
FIG. 5 illustrates the turbine stage of FIG. 4 in more detail.
FIG. 6 illustrates a polygonal ring which supports the fan blades.
FIG. 7 illustrates one of the sectors of the polygonal ring which supports a fan blade.
FIG. 7A illustrates the relative positioning of the turbine stage 36A, the polygonal ring 42 and the cowling 20F.
FIG. 8 illustrates a top view of one of the cowlings.
FIG. 9 is a more detailed cross-section of the type shown in FIG. 2.
FIG. 10 illustrates one of the propeller blade platforms.
DETAILED DESCRIPTION OF THE INVENTION
Introduction
One form of the invention is shown in FIG. 3. Cowlings 20A and 20F (shown schematically in FIGS. 1 and 2) surround the contra-rotating turbo machinery 25 shown in FIG. 2. The turbo machinery 25 in FIG. 2 receives high-energy gases 30 provided by a gas generator (not shown) which rotates turbines 36 and 39 in opposite directions. Each turbine drives a respective fan 10A or 10F. The fans are not directly fastened to the turbine, as shown in FIG. 2, but are each fastened to an intermediate polygonal ring, shown schematically as ring 42 in FIG. 5 and ring 42A in FIG. 7. Cowls 20A in FIG. 3 and 20F in FIG. 7 are also fastened to ring 42. The following discussion will describe (1) the polygonal rings which support both the fan blades 10 and the cowls 20; (2) the mounting rings which act as the attachment points between the cowls and the polygonal rings; and (3) the panels which span between the mounting rings and form the surface of the cowl along with the mounting rings.
Polygonal Rings
FIG. 4 shows the turbine stage 36A in FIG. 2, together with fan blades 10F and cowl region 20F in FIGS. 1 and 3. This stage 36A is shown in greater detail in FIG. 5, which shows schematically a ring 42 which supports the fan blades 10F. The fan blades 10F are carried by the ring 42, rather than connected directly to the turbine 36A, for at least two reasons.
One reason is that different design considerations apply to internal, turbine components, as compared to external, fan components because fans and turbines serve different purposes. For example, a new turbine may be designed which is smaller than a previous turbine, yet drives the same fan blades. The use of ring 42 in Figure as an intermediate component reduces the impact of the turbine change upon the fan: the new turbine need only be mounted to the ring 42, and the fan need not be modified.
A second reason is that the use of the ring 42 and bracket 50 decouples thermal growth of the turbine casing 2 from the fan blades 10. The casing 52 (to which turbine blades 53 are attached) can expand with increasing temperature, while supporting the ring 42, yet without unduly stressing the ring, because bracket 50 deforms: legs 52A and 52B separate from each other. That is, the deformation provides a type of floating mount of the ring 42 upon the casing 52.
The ring 42 does not actually take the form of the hoop shown in FIG. 5, but more resembles the polygonal ring shown in FIG. 6. Some sectors 42A of the ring 42 contain bearing races 54 and bearings 56 in FIG. 7 which react the centrifugal load imposed by the fan blades 10F, and allow blade rotation about pitch axis 58 in order to change pitch, as indicated by arrow 58A.
Each polygonal ring is mounted to the casing 52 of the turbine stage 36A by brackets 50 in FIG. 5. Details concerning the construction of one type of polygonal ring are found in the U. S. Patent Application "Blade Carrying Means", filed by Hauser, Strock, Morris & Wakeman on Nov. 2, 1984, and having Serial Number 667,663. This application is hereby incorporated by reference.
Mounting Rings
Each polygonal ring supports a forward and an aft mounting ring 60 and 62 in FIG. 3. FIG. 7A shows the relationship between the turbine stage 36A, the polygonal ring 42 and the cowling 20F. Brackets 50 (shown in FIG. 5) connect the ring 42 to the turbine casing 52. Other brackets, in the form of flange 51 in FIG. 3, connect the cowl 20F to the ring 42. Bolts extend through holes 51A to make the connection.
As shown in FIGS. 3 and 9, the forward mounting ring 60 contains a flange 64 near the inner surface 66 of the trailing edge 68 of nacelle 18. An annular channel 70, shown as an arrow in FIG. 9, is thereby formed which communicates with either or both (1) cavity 72 within the cowling 20F and (2) the interior region 74 of the nacelle 18.
Similarly, as shown in FIG. 3, the forward mounting ring 60 of the aft cowl 20A has a flange 82. This flange 82, in conjunction with the inner surface 86 of the trailing edge 88 of the aft mounting ring 62 of the forward cowl 20F, defines a channel 84. Thus, a second annular channel 84 communicates between cavity 94 and the external space 102 between fore and aft fan rotors 10F and 10A.
The flowpaths 70 and 84 allow ventilation of cavities 72 and 94 for cooling purposes, and for purging flammable vapors such as those emanating from lubricants. These cavities are maintained at higher pressures than external regions 101 and 102, in a manner known in the art, and so cooling air flows outward from the cavities as indicated by flowpath arrows 70 and 84. However, such cooling is not necessary in all situations, nor in all flight conditions.
Two important features of the flanges 64 and 82 in FIG. 9 are the following: One, the angle A which each flange makes with the cowl surface 110 should not exceed fifteen degrees. This angle constrains the flowpaths 70 and 84 to be nearly parallel with (or at least within 15 degrees of) the fanstream flow, indicated by arrow 112, to thereby promote mixing with reduced turbulence. It is desirable that the fans ingest air having as little turbulence as possible.
A second feature of flanges 60 in FIG. 9 is that their length, dimension 114, should not exceed twenty percent of the chord length 116 of the respective fan blade into which the flange directs air. One reason is that, in general, the boundary layer (not shown) of flow across a surface tends to increase in thickness in the downstream direction. Eventually, the boundary layer becomes turbulent. The twenty percent limit either (1) reduces the likelihood of delivering a turbulent boundary layer to a fan, or (2) prevents a thick boundary layer from entering a fan, or both. There is no flowpath downstream of aft fan 10A analogous to flowpath 84. Instead, the aft frame 62 of the aft cowl 20A supports a faired structure 111 in FIG. 1 which rotates along with aft fan and also defines the inner fan flow path and outer flowpath of the turbine.
Panels
In addition to defining the ventilation flow paths just described, the pairs of mounting rings 60 and 62 in FIG. 3 also support cowl panels 120, as will now be described. The panels define the fan flow path between the fan blades. For eight panels in FIG. 3 between eight fan blades, each panel 120 spans an arc (angle B) of approximately forty degrees. Other, filler panels 122 each span about five degrees (angle C). The reason each access panel does not span a full forty-five degree arc (360/8=45) is the difficulty that this would cause for panel removal.
That is, if an access panel 120 extended a full forty-five degrees, then the fan blade 10 would obstruct removal of the access panel. As shown in FIGS. 7 and 8, each fan blade 10 has fore and aft cuffs 126 and 128. The blade cuffs overhang the panels 120 in FIG. 8, while the central region 130 of the blade lies above a platform (later discussed), not above the panels.
Dashed line 132 indicates the interface which would exist between adjacent panels 120 in the absence of filler panels 122. That is, dashed lines 132 indicates that each panel 120 spans 45 degrees of arc. The cuffs make it difficult to remove the panels because the clearance 133 in FIG. 7 is of the order of 1/4 or 1/2 inch. Further, as shown in FIG. 8, no matter what pitch angle B the fan blade 10 has, part 136 of one panel 120 and another part 138 of a neighboring panel 120 will lie beneath the cuffs. Clearly, with the situation just described, it is difficult to lift panel 120 outward, in the direction perpendicular to the paper.
One solution is to construct the panels to span less than one pitch axis separation. (Pitch axis is the axis 58 in FIG. 4 about which a fan blade rotates in changing pitch. Pitch axis separation is the angular distance PAS, in degrees or equivalent, between neighboring pitch axes.) This solution is shown in FIG. 8, wherein filler panels 122 replace the ends of panels 120 in regions 123.
One removes a panel 120 in FIG. 8 by positioning the fan blade so that the cuffs lie above the filler panels 122, as shown. One removes one or more panels 120, and then one removes the filler panels 122, perhaps after changing blade pitch to increase clearance for the removal of filler panels.
Each panel 120 in FIGS. 3 and 8 contains two semicircular cutouts 140 and 142. As shown in FIG. 3, each cutout mates with a circular fan blade platform 146, also shown in FIG. 10. The periphery of the platform 146 bears a resilient seal 147 which seals the interface between the platform and the circle defined by cutouts 140 and 142.
When the platform cowl system is assembled, virtually all of the air within cavities 72, 74 and 94 in FIG. 9 is forced to exit through channels 70 and 84 rather than through the interface sealed by seal 147 in FIG. 10 between the platform and panel.
As shown in FIG. 10, platform 146 is slightly concave. That is, if a straight line 152 were drawn between the leading edge 161, and the trailing edge 162 of fan blade 10, a distance 164 would exist between the platform and the straight line near mid-chord. This concavity 164 allows a small diffusion of air to occur in order to reduce the tendency of the space between adjacent fan blades to behave as a nozzle. That is, as shown in FIG. 4, distance 168 (which is the distance between two imaginary lines located directly in front of the leading edges of neighboring fan blades 10) is greater than distance 169 (which is the distance between facing surfaces of neighboring blades), thus forcing air at point 170 to accelerate in passing between fan blades.
Several important features of the invention are the following:
1. As shown in FIG. 3, the access panels are mounted by bolts 171 to mounting rings 60 and 62 along the fore F and aft A edges of the panels. The center regions 172 are unsupported. In operation, centrifugal loading causes the center regions 172 to bulge outward as shown by phantom line 175 in FIG. 3. A bow of 1/10 inch (dimension 173) has been measured by the inventors. This tendency to bow is countered by the installation of stiffening ribs 174, which reduce bowing. Alternately, a stiffening layer of a honeycomb material (not shown) can be installed on the inner surface 178 of access panels 120. In addition, panels of narrow cross section can require stiffening for acoustic reasons.
2. Eight fan blades per cowl have been discussed. It is, of course, recognized that the number 8 is not critical, nor is it critical that an equal number be associated with each cowling.
3. The access panels shown have ends 180A and 180B in FIG. 8 which terminate at approximately the same position on fore and aft mounting rings 60 and 62, as indicated by phantom line 181. However, this is not necessary. For example, as shown in FIG. 3, ends 200A and 200B on the aft cowl can terminate at the positions shown. Appropriate filler panels, such as 200C and 200D, shown notched, are then used. Restated, the relative positions of filler panels 122 dictate the pitch angle B at which the blade must be set in order for removal of access panels 120.
4. The access panels, such as panel 120 in FIG. 8, can be split into two parts by a seam 130. This splitting can further facilitate removal of the panels from beneath the blades 10. The panel region near the seam 130 can be first raised, and then the panel can be slid out from under a blade.
An invention has been described wherein a counterrotating propeller pair surrounds a counterrotating turbine pair which drives the propellers. The propellers are not connected directly to the respective turbines, but each is connected to a polygonal ring which surrounds and is fastened to one of the turbines.
A rotating cowl is connected to each polygonal ring and defines the propeller flowpath. Each cowl includes (a) a pair of annular mounting rings and (b) several panels extending between the mounting rings and defining the flowpath shape. Further, there is an annular channel near the upstream ring of each pair which assists in ventilation of the space contained within each cowl. The ventilation air 70 in FIG. 9 exhausts into the propeller airstream 112.
The panels contain cutouts so that, when assembled, the panels resemble cylinders with a series of circular holes perforating the surface. The holes are to contain circular blade platforms which rotate along with the blades during pitch change. A resilient seal is positioned between the edge of the circular platform and the circular hole in the panels into which the platform fits.
Each platform contains a concavity which has the effect of increasing the annular height of the flowpath above the concavity. That is, the height 225 in FIG. 9 is greater than height 227. The increase in height decreases the tendency of air to accelerate through the channels defined by neighboring fan blades.
The terms "fan" and "propeller" have been used in the discussion above. It should be understood that, in the present context, there is no difference in ultimate function between the two: both of them provide thrust to an aircraft by imparting a momentum change to ambient air. While it is true that fans and propellers are generally viewed as having different characteristics, as respects, for example, (a) ducting or the lack of it, (b) the amount of pressure rise across the disc, (c) pitch change aspects, and (d) blade root diameter, it is not seen as critical whether the thrust-providing device is called a fan or propeller in the present invention.
Numerous substitutions and modifications can be undertaken without departing from the true spirit and scope of the invention as defined in the following claims:
|
The invention concerns a cowling for aircraft propulsion systems of the counterrotating propeller type. The cowling includes a pair of mounting rings located fore and aft of a propeller array. Removable panels extend between the mounting rings and contain openings through which the propeller blades extend.
| 1
|
BACKGROUND OF THE INVENTION
PRIOR ART
The invention concerns a firearm, in particular a hand firearm with a bolt carriage borne in a displaceable fashion in a weapon housing for motion, in or in opposition to, the firing direction between stops for the front firing position and the rear open position, with a barrel borne in an axially displaceable fashion in an opening at one radial side of the bolt carriage, the bolt carriage having an impact surface serving as a stop for the back end of the barrel, and with a guide rod borne at its front end section substantially parallel to the barrel in a guide opening of a yoke member disposed for formed fitting displacement with the bolt carriage and is connected at its rear side with the barrel via a carrier coupling allowing displacement play, and with an advancing spring (closing spring) which engages at its front end, the bolt carriage and, at its other end, the housing in the vicinity of the rear end section of the guide rod and with a locking mechanism which locks the barrel and the bolt carriage with respect to each other in a displacement direction in the front firing position and which unlocks them after the bullet leaves the barrel after a certain common recoil displacement in a direction opposite to the shooting direction in consequence of which the bolt carriage continues toward the open position whereas the path of the barrel is stopped by an abutment. Such firearms have a locked bolt and release the locking shortly after firing the bullet and after the shot has left the barrel and the bolt carriage, including the barrel, have recoiled along a certain length. After unlocking, the barrel travel is stopped by an abutment, whereas the bolt carriage continues along its path into the opened position. The empty cartridge is thereby expelled and a new cartridge having a bullet and a charge slips into the cartridge bearing provided in the rear end of the barrel due to the separation between the cartridge bearing and the impact surface resulting during the forward motion of the bolt carriage. After the bolt carriage returns to the firing position, the bolt carriage carries the barrel via its impact surface along with it into the forward firing position, wherein the barrel is once more locked to the bolt carriage. This construction has prevailed in particular with larger cartridges having high caliber e.g. 9 mm parabellum, since such a locked bolt structure facilitates a bolt carriage of substantially reduced weight. and also provides a maximum amount of safety for the rifleman.
In a conventional firearm (Colt-Browning system) mutually engaging grooves and protrusions are disposed on the upper side of the barrel and in the opposing inner side of the bolt carriage which snap into each other in the locked position. After the shot has been fired and after recoil along a certain length, a chain link member pulls the end of the barrel in a downward direction for unlocking. The link cooperates with a stationary transverse bolt which simultaneously serves as a stop. This type of construction with which the barrel, during its motion in the backward direction, is simultaneously pulled downwardly, requires an appropriate amount of play in guiding the barrel (also at its front portion) leading to a reduced accuracy which increases with use. The link motion of the barrel dictated by this structure can only assure firing precision when particular types of ammunition are used and not with other types of ammunition often preferred by the riflemen.
In another conventional firearm in accordance with the precharacterized part of the main claim (DE PS 43 41 131), the back section of the barrel has a reinforcement in the vicinity of the cartridge bearing which forms a shoulder cooperating with an opening in the bolt carriage in such a fashion that when firing, the barrel is firmly locked to the bolt and after the bullet has left the barrel, the barrel must be pivoted in a downward direction at its back end for unlocking, wherein the reinforcement moves through the opening to allow the bolt carriage to glide past this clearance. This unlocking motion is achieved by a link disposed below the barrel which, after recoil along a certain length, cooperates with a corresponding opposing member disposed in the housing in such a fashion that the back portion of barrel is pulled in a downward direction and unlocked during the additional common motion of the bolt carriage and barrel.
The mutually facing transverse surfaces on the bolt carriage and the barrel which serve for locking are relatively small in this conventional firearm so that a substantial degree of surface loading occurs after the shot has been fired. This is particularly disadvantageous, since the bolt carriage material and in particular that of the barrel is relatively soft, which could lead to distortions, jamming, and to increased play.
Particularly in the original Colt-Browning system)the slanted barrel leads to an increased torque acting on the weapon during firing due to the increased separation between the force vectors of the cartridge and the hand of the rifleman, resulting in a stronger upward recoil of the weapon. Particularly when a plurality of bullets are sequentially fired, a time consuming reaiming is thereby necessary.
The slanted pivoting of the barrel also disadvantageously necessitates a minimal separation between the barrel axis and the guide rod axis so that the triggering device must also have a point of rotation or a finger grip position which is relatively far from the axis of the barrel. This is disadvantageous during firing due to the resulting lever arm relationships.
SUMMARY OF THE INVENTION
The firearm in accordance with the invention having the locking mechanism disposed on the guide rod, the guide rod being rotatable and/or pivotable independent of the barrel for locking and unlocking purposes and the unlocking occurs without radial displacement or rotation of the barrel. This has, the advantage that the barrel is not pivoted. This feature also obtains for barrels preferred in recreational competitive shooting which, due to their targeting accuracy, function with a spring bolt only. For this reason, the barrel can be precisely guided in the bolt carriage. In addition, displacement of the locking mechanism into the region of the guide rod allows for increased locking surfaces and therefore the surface pressure on the locking surfaces can be reduced and/or a hard material can be utilized at these locations which is different than the material used for manufacturing the barrel or the bolt carriage.
An additional substantial advantage of the invention is that the separation between of the barrel and the guide rod axes can be as small as possible in order to maintain a lower "siting line" for improving the handling and reliable shooting behaviour of the firearm.
Additional important advantages are primarily associated with the freedom in design for the barrel and the bolt carriage particularly with regard to the stability, loadability and balancing of the weapon, since conventional locking mechanisms in the barrel jacket and in the walls of the bolt carriage always lead to an associated weakening thereof.
The free design possibilities for the barrel and the bolt carriage facilitate production of different types of pistols such as, for example, compact pistols in the 9 mm caliber range as well as magnum versions.
In accordance with an advantageous embodiment of the invention, the locking and unlocking is effected through cooperation between the collar member in the vicinity of the guide opening and the front end section of the guide rod.
Configuration in the front end portion of the guide rod leads to a corresponding load relief of the back end section and of the entire bolt region which are overloaded by rarious tasks. Since the guide rod is guided in the collar member guide opening, there is a sufficient amount of room for designing a locking device. Primarily advantageous are the compact space and low-weight structure with which the lock is disposed at a position removed from the cartridge bearing such that the barrel and the bolt carriage are not weakend. Since there is a sufficient amount of room in the region of the collar member, a locking device can be designed using appropriately hard materials without thereby weakening the barrel or the bolt carriage. As is known in the art, the barrel material is selected to have a high amount of toughness and not a great degree of hardness.
In accordance with an additional advantageous configuration of the invention, the locking device consists essentially of a bayonet locking connection opened in the forward direction which is disposed between the guide rod and the guide opening and with which a radial peg disposed on the guide rod engages in a corresponding locking groove to prevent a relative displacement in the axial direction between the bolt carriage and the barrel. Only after the guide rod has been rotated does the radial peg gain access to that part of the locking groove extending in the shooting direction, so that a relative longitudinal displacement between the bolt carriage and the barrel is facilitated. These mutually engaging bayonet locking mechanisms can be easily made from a hard material, wherein relatively large operating surfaces between the radial peg and the wall of the groove can be manufactured depending on design requirements. The radial peg can be a pin connected to the guide rod. A plurality of this type of radial pegs are however preferred in the form of noses of rectangular cross section which are preferentially disposed centrally and symmetric to each other.
In an additional advantageous embodiment in accordance with the invention, four locking grooves and corresponding radial pegs are provided for, wherein the guide opening in the end sided plan view has the shape of a thickened cross (iron cross, knight's cross). This intrinsically practical configuration provides improvement in appearance, since a thickened cross has positive associations for the riflemen. Of course the shape can also have only two or three radial pegs.
In accordance with an additional advantageous embodiment of the invention, the locking is effected through toothed engagement between the guide opening and the guide rod with a ring groove disposed in the end section to facilitate rotation for unlocking. This type of toothed engagement leads to a smooth axial guiding during relative displacement between the bolt carriage and the barrel which, however, first enters into effect when recoil is ended and when the locking mechanism permits, by means of rotation, this relative displacement between the bolt carriage and the barrel and of the guide rod coupled to the barrel. Since unlocking is effected through displacement of the radial peg into the transverse section of the locking groove, and since a rotation of the guide rod in the guide opening is thereby required, a ring groove on the outer surface of the guide rod in the vicinity of the guide opening is thereby required such that, subsequent to rotation, the longitudinal components of the guide rod can engage in corresponding longitudinal wedge grooves in the guide opening.
In accordance with an additional advantageous configuration of the invention, the recoil spring is disposed coaxially on the guide rod and is a spring "captured" via support shoulders to engage the end sections of the guide rod. The "captured spring" has the particular advantage that, when the firearm is disassembled, components such as the guide rod cannot spring off. Such disassembly is repeatedly necessary both for cleaning the firearm as well as for training people to use the firearm. The spring can therefore be captured on the guide rod since same is relatively long to therefore also advantage only permit simple introduction of a spring having the desired characteristics.
In accordance with an additional advantageous embodiment of the invention, the support shoulder is a ring disposed on the front end section of the guide rod with corresponding configuration for the locking mechanism. The ring can be disposed in a variety of differing ways on the end section of the guide rod, wherein displacement of the guide rod in the guide opening of the collar member causes the wedged portions of the guide opening or a support ring disposed behind the collar member, to push the spring together. The ring can also be fashioned from a press-fit bushing made from hard material and pressed onto the relatively soft material of the guide rod, wherein the guide rod can advantageously consist of non-rusting steel. In this manner, it is also possible in accordance with the invention for the radial pegs to be integrated into the radial region of such a pressed bushing and also possibly in a bushing pressed into the collar member. The ring can also be a spring plate displaceable on the guide rod.
In accordance with an additional advantageous configuration of the invention, the guide rod has two longitudinal components, wherein damping spring and/or a stop is disposed between the components coaxial with the recoil spring. Such a damping spring can minimize recoil effects occurring during firing as well as the load on the weapon. It is thereby possible, and in particular during training and competitions in differing shooting sport disciplines, to aim at a target rapidly and to fire a plurality of shots in the shortest possible amount of time This type of configuration also allows the recoil spring to be "captured".
In accordance with an additional advantageous configuration of the inventions a stop is disposed between the two portions of the guide rod coaxial with respect to the recoil spring. It is possible to do without the damping spring in particular for small caliber applications,to reduce production costs.
In accordance with an additional advantageous configuration of the invention, a rotation device is disposed in the rear end section of the guide rod and in the surrounding housing for rotating the guide rod after travel through the clearance displacement for unlocking. Separation of the locking and the rotating devices, wherein both locking and unlocking each occur by means of rotation, facilitates the practical design of the two end sections of the guide rod for their corresponding tasks and in a manner allowing disassembly.
In accordance with an additional advantageous embodiment of the invention, a clasp member can be inserted into the firearm housing to serve as a housing surrounding the rotation device. The inner surface of the clasp member faces the guide rod. This clasp member can also be made from a hardened material adapted for its particular purpose and can assume both guiding as well as structural tasks.
In accordance with an advantageous embodiment of the invention, the rotation device comprises a slotted hole extending transverse to the guide rod and penetrating through same which curves with respect to the longitudinal axis (spirals) and a pin penetrating therethrough which is borne in the surrounding housing. Following clearance displacement the spring guide rod is thereby rotated by guidance of the spiralled wall of the slot on the outer pin surface.
In accordance with an advantageous embodiment of the invention, ring collars disposed on the guide rod in the vicinity of the spiral portion of the longitudinal hole serve to strengthen the material in this region of particularly high load, since, in this location, the pins guide the guide rod into and out of the rotating path in response to its forward motion. In addition, the ring collars and the resulting ring groove serve for guiding the guide rod and for axial connection between the barrel and the guide rod.
In an additional advantageous embodiment, link pegs are radially disposed on the rear end of the guide rod with corresponding link grooves being disposed in the surrounding housing for producing the rotating motion of the barrel guide, wherein the link pegs serve as supporting shoulders for the advancing spring. In accordance with the invention, two linked pegs are advantageously disposed on opposite sides of the end section of the guide rod, wherein the linked pegs have surfaces co-operating with the associated guiding surfaces of the link grooves and also have surfaces disposed transverse to the longitudinal axis of the guide rod which serve as support shoulders for the advancing spring. The surrounding housing can be formed by a special component inserted into the firearm housing or could also be the firearm housing itself. This is a design issue for constructing either a particularly narrow firearm or for adapting to particular materials. Since the diameter of the guide rod can, in any event, be less than that of the barrel, which, together with the bolt carriage determines the overal width of the firearm, there is generally enough room for configuration of an additional component for accepting the link groove.
In accordance with an additional advantageous configuration of the invention, a barrel hook is disposed on the rear end section of the barrel which engages the guide rod, which is secured against rotation relative to the housing, and which serves as a stop for the guide rod. The guide rod is rotatable relative thereto. A barrel hook of this type is per se known in the art (DE OS 1 703 417) however not in cooperation with the guide rod such that the latter can independently rotate.
In accordance with an advantageous configuration of the invention, a peg or a bore hole is disposed on the stop side of the barrel hook or on the rear end of the guide rod which cooperates with a central axial bore hole or a central axial peg of the guide rod or of the barrel hook. Such a peg or bore hole primarily serves for guided rotation of the guide rod.
In accordance with an additional advantageous embodiment of the invention, the barrel hook has a bushing placed over the barrel and firmly connected to same. This allows the barrel to be made from a tough and possibly non-rusting material, whereas the bushing and barrel hook, which are subjected to completely different loads, can be made from a hard material. The combination of two different materials having different properties can be advantageous with respect to function and production costs, especially for small calibers.
In accordance with an additional advantageous configuration of the invention, a longitudinal slot or a path limiting opening is present on the barrel hook which co-operates with a retaining pin anchored in the housing. Since the barrel has an axial guide, the opening limiting the stroke of the barrel can be opened in a downward direction. Such a configuration is more advantageous to produce and more compact than embodiments having a slotted hole.
In accordance with an additional embodiment of the invention, the retaining pin serves as a carriage block and trigger bearing, to effect a more compact structure at reduced manufacturing cost.
In accordance with an additional advantageous embodiment of the invention, the axial peg has a spiralled flattened portion and the corresponding axial bore hole intersects with the opening or with the slotted hole in the barrel. In this manner, when assembling the firearm, the retaining pin can only be introduced when the firearm is locked or it locks the firearm through rotation of the guide rod in consequence of guiding by the spiralled flattened portion.
In accordance with an additional advantageous embodiment of the invention, the barrel is axially guided only in the vicinity of the side facing away from the opening in the barrel, wherein the barrel can freely vibrate after firing a round. Such a freely suspended barrel increases the precision of the firearm.
In accordance with an additional advantageous configuration of the invention, a leaf spring disposed in the firearm housing holds the trigger lever and/or pushes the interrupter in the forward and upward direction to facilitate a compact construction and low manufacturing costs.
Further advantages and advantageous embodiments of the invention can be extracted from the following description of the drawing and claims.
BRIEF DESCRIPTION OF THE DRAWING
Two embodiments of the object of the invention are shown in the drawing and more closely described below.
FIG. 1 shows a partial longitudinal cut of a first embodiment;
FIG. 2 shows a side view of the guide rod in accordance with FIG. 1;
FIG. 3 shows a longitudinal partial cut of a second embodiment;
FIG. 4 shows an exploded view of portions of FIG. 3;
FIG. 5 shows a cross section according to line III--III of FIG. 3;
FIG. 6 shows a side view of the barrel and guide rod section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 and FIG. 3 show the two embodiments in a locked position ready for firing. For purposes of simplicity, the spatial designations used below such as "down", "up", "back" and "front" refer to the normal shooting position of the firearm with a horizontal sighting axis, wherein the direction of firing is the "front".
The first embodiments shown in FIG. 1 shows a bolt carriage 2 guided in a longitudinally displaceable fashion on a conventional displacement guide of a weapon housing 1. A barrel 3 is guided in an axially displaceable fashion in the lower front open section of the bolt carriage 2, the barrel 3 having an additional guide in an opening 4 of the weapon housing. An advancing spring 5 is disposed below the bolt carriage 2 and cooperates therewith to slow down and return the bolt following firing. This advancing spring 5 is axially disposed on a spring guide rod 6 borne at its front section in a guide opening 7 with its back section being borne in an appropriate opening 8 in the weapon housing 1. The back end of the guide rod 6 is connected to the rear end section of the barrel 3 in an axially rotatable fashion in the vicinity of the barrel hook 9 and guided via two ring collars 53. A slightly curved slot 10 is provided in the rear end section of the guide rod 6 transverse to the longitudinal direction through which a pin 11 borne in the weapon housing 1 penetrates so that the guide rod 6 experiences a rotation corresponding to the spiral when axially displaced in the backward direction.
The guide opening 7 of the guide rod 6 is disposed in a yoke member 12 located at the front end of the bolt carriage 2 and projecting in a downward direction. In addition, this embodiment has a damping spring 56 on this guide rod 6 for minimizing the load or recoil occurring following firing. A stop ring 13 is disposed on that side of the guide rod 6 facing away from the yoke member 12 for limiting the recoil of the barrel 3 and therefore also of the guide rod 6 and functions as a stop upon which the damping spring seats to limit displacement. In the firing position of the weapon shown, i.e. in the rotated position of the guide rods 6 shown, the inner teething 14 and the outer teething 15 are disposed behind each other in such a manner that they do not mutually engage and, when the bolt carriage 2 is displaced in the backward direction, the guide rod 6 is carried along therewith and rotated by means of the slot 10 and the pin 11, wherein the inner teething 14 and the outer teething 15 mutually engage another so that the guide rod 6 can be displaced with its front end through the guide opening 7.
FIG. 2 shows the slotted hole 10 in the guide rod 6, wherein a material strengthening of the guide rod in the form of two ring collars 53 is effected in the regions of particularly high material loading where the pin 11 and the curved slotted hole 10 transform the transitional motion of the guide rod 6 into rotational motion. In addition, the ring collars serve for fixing and guiding the guide rod and for their axial fitted engagement with the barrel.
As soon as the round is fired, the recoil displaces the bolt carriage 2 in the backward direction. The bolt carriage 2 carries, via the guide rod 6 and the ring collars 53, the barrel along with it through a displacement defined by the slot 10 and the pin 11 wherein, following rotation of the guide rod 6, the damping spring 56 abuts against the holding ring 13. Due to the resulting unlocking at the inner teeth 14 and the outer teeth 15 of the yoke member 12, the bolt carriage 2 continues, via the guide rod 6, its path in a backward direction into its opened position, while carrying or compressing the advancing spring 5. At this point, the empty cartridge is expelled and a new cartridge is introduced into the barrel. A straight teething 16 is disposed on the guide rod 6 as is clearly shown in FIG. 2 which interlocks with the inner teething 14 in the guide opening 7 during the entire stroke of the bolt carriage 2 subsequent to unlocking. Upon return of the bolt carriage 2 into the locked position shown, an impact surface 17 disposed on the inner side of the bolt carriage 2 strikes against the back end of the barrel to carry same over the remaining return path. The return rotation of the guide rod 6 caused by the slotted hole 10 and the pin 11 cause the outer teething 15 to come to rest behind the inner teething 14 to once more lock the barrel 3 to the bolt carriage 2.
The second embodiment shown in FIG. 3 is in principle similar to the described embodiment of FIG. 1. In order to simplify understanding, the corresponding reference symbols in this embodiment are each increased by 20 compared to those of the first embodiment.
The firing pin 38 is borne in opposition to the force of a restoring spring 39 in the rear portion of the bolt carriage 22 in such a fashion that it strikes the back of the cartridge following firing of the hammer 41 to ignite same. The bolt carriage 22 is, as shown in FIG. 5, displaceable on a bed 42 wherein an inwardly engaging tongue 22 of the bolt carriage 42 engages into a corresponding groove 44 disposed in the weapon housing 21. In this manner, the bolt carriage 22 can be displaced on the bed 42 or the weapon housing 21 from the locked position into the open position and back again with firm radial anchoring. Stops (not shown) limit this displacement path.
A bayonet connection serves as a locking device in this case with which, in the locking position shown, radial pegs 45 disposed at the front of the guide rod 26 abut behind radially inwardly extending abutments 46 and only move from this locked position into a position in which the radial pegs 45 can slide past the stops 46 after travel through a clearance displacement with associated rotation of the guide rod 26. FIG. 4 shows an individual component representation of the guide rod 26 with straight teeth 36 as well as the radial pegs 45. FIG. 5 shows a cut through the grooves fashioned between the abutments which, in this embodiment, have the shape of an iron cross.
In this embodiment, the rotation of the guide rod 26 is effected by link pegs 48 disposed on both sides at the end of the guide rod 26 which each travel within a link groove 52 shown FIG 4. The link groove has a first section extending in the longitudinal direction of the firearm, followed by a spiral shape so that the guide rod 26 is rotated as soon as the link peg 48 enters the spiral section. The guide rod 26 is supported by a barrel hook 29 of barrel 23 in which a slot 49 is fashioned which serves for limiting the travel of the barrel 23 and of the guide rod 26 through co-operation with a retaining pin 51 mounted on the housing. The advancing spring 25 disposed on the guide rod 26 is supported by the link peg 48 at its rear end and by the yoke member 32 at its front.
The embodiment of the barrel guide rod connection shown in FIG. 6 illustrates the back end of the barrel 3 having the barrel hook 9, the opening 28 and the slot 49, the axial bore hole 55 located in the barrel hook as well as the back end of the guide rod 6 with the associated axial peg 54 having spiralled flattened portions. When assembling the firearm, the retaining pin 51 is guided in the slot, The spiralled flattening of the axial peg causes the guide rod 6 to rotate the locking device in the locked state to prevent improper assembly of the firearm.
All the features which can be extracted from the description, the claims, and the drawing can be important to the invention either individually or in arbitrary combination.
______________________________________LIST OF REFERENCE SYMBOLS______________________________________1, 21 Weapon housing2, 22 Bolt carriage3, 23 Barrel4, 24 Opening in 25, 25 Advancing spring6, 26 Guide rod7, 27 Guide opening for 68, 28 Opening for 69, 29 Barrel hook10 Slot11 Pin12, 32 Yoke member13 Stop ring14, 34 Inner teething15, 35 Outer teething16, 36 Straight teething17, 37 Impact surface18, 38 Firing pin19, 39 Restoring spring4041 Hammer42 Bed43 Tongue44 Groove45 Radial peg46 Stops47 Grooves48 Link peg49 Slot5051 Retaining pin52 Link groove53 Ring collar54 Axial peg55 Axial bore56 Damping spring______________________________________
|
A firearm, in particular a hand firearm is proposed having a displaceable barrel (23) and a locking mechanism between a bolt carriage (22) accepting the barrel and a guide rod (26) coupled to the barrel (23), wherein the unlocking is effected through rotation of this guide rod (26)
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. patent application Ser. No. 13/154,390, filed on Jun. 6, 2011, which is a continuation of Prior application Ser. No. 12/200,159, filed on Aug. 28, 2008, which is a division of U.S. patent application Ser. No. 10/744,522, filed on Dec. 23, 2003, which is a division of U.S. patent application Ser. No. 09/974,209, filed on Oct. 10, 2001, now abandoned, which claims priority from U.S. Provisional Patent Application Ser. No. 60/239,788, filed Oct. 12, 2000, the disclosures of which are hereby incorporated by reference herein.
TECHNICAL FIELD AND BACKGROUND OF THE INTENTION
[0002] This invention relates to an improved conductively coated transparent substrate as used in an interactive touch information display such as a transparent digitizer, near field imaging touch screen, electromagnetic touch screen, or an electrostatic touch screen. These products typically utilize a transparent conductive thin film on a rigid glass substrate and with the transparent conductor deposited in a specific pattern as required by product design and with a region coated with a transparent conductor immediately adjacent to a region uncoated with a transparent conductor. This results in an interactive device consisting of areas A and A′ of non-coated substrate contrasting with areas B, B′, B″, and B′″ of conductively coated substrate as shown in FIG. 1 . However, a known disadvantage of current such designs is that the contrast between the coated and adjacent uncoated region is plainly visible in reflected light, often leading to consumer dissatisfaction. This contrast arises from the optical in homogeneity created by the optical properties of the transparent conductive coating, (typically having a refractive index greater than 1.65), compared to the refractive index of the uncoated adjacent region, (typically having a refractive index in the range of 1.5 to 1.55). Further, in many interaction devices, a delineated transparent conductive coating is affixed on both sides of the same substrate thus even further exacerbating the consequences of the optical inhomogeneity on both sides, of the substrate. This optical inhomogeneity may require the interactive input device to be configured with the information device such as a liquid crystal display in front of the interactive input device, a configuration not optimum for interactive performance fur the consumer. This invention reduces the optical inhomogeneity between the areas of non-coated substrate and the areas of coated substrate. This allows tar the interactive input device to be bonded directly in front of the information device, such as a liquid crystal display, the configuration preferred far electrical and optical performance by the consumer.
BRIEF SUMMARY OF THE INVENTION
[0003] The present invention contemplates the coating of a transparent metal oxide material using conventional methods known in the wet chemical coating art such as spin coating, roll coating, meniscus coating, dip coating, spray coating, or angle dependent dip coating on a discrete patterned conductively coated glass substrate as used in a transparent interactive, input device such as a transparent digitizer, or a near field imaging touch screen, or an electromagnetic touch screen, or an electrostatic touch screen. Physical vapor deposition techniques, such as coating by sputtering or coating by evaporation, are also applicable coating methods. When the additional outermost transparent layer of, for example, a metal oxide such gas silicon dioxide, is disposed on the substrate on top of the outermost layer of the patterned transparent conductively coating, visible contrast between the non-conductively coated areas of the coated panel and the conductively coated areas of the coated panel is reduced and overall light transmission is increased. It is most preferred to use the wet chemical coating method known to those skilled in the art as dip coating, or angle dependent dip coating, to establish a coating simultaneously on both sides of the delineated conductively coated substrate.
[0004] In one form, the invention is a reduced contrast, increased transmission conductively coated panel comprising a substrate having a first surface and a second surface, a transparent, conductive layer on at least one surface of the substrate, the conductive layer being in a predetermined pattern such that there is at least one area having a conductive layer thereon and a second area without a conductive layer on said one substrate surface. A transparent layer of metal oxide overlies both areas of the substrate surface such that visible contrast between the areas is reduced and light transmission through the coated panel is increased and wherein the coated panel is adapted for use in an interactive device.
[0005] In other aspects, the transparent substrate may be glass or plastic, the transparent, conductive layer may be one of indium tin oxide, doped tin oxide or doped zinc, oxide, while the transparent metal oxide layer may he silicon dioxide.
[0006] In yet other aspects, the second surface of the substrate may also include a transparent, conductive layer in a predetermined pattern with at least one conductively coated area and a second area without a conductive coating, and a transparent metal oxide layer, for example silicon dioxide, overlying those areas.
[0007] In yet a further aspect of the invention, a transparent interactive input device comprises an electro-optic display for displaying information when electricity is applied thereto and a conductively coated panel optically bonded to the electro-optic display. The panel includes a substrate and a transparent, conductive layer on at least one surface of the substrate, the conductive layer, being in a predetermined pattern such that there is at least one area having a conductive layer thereon and a second area without a conductive layer. A transparent layer of metal oxide overlies both areas whereby visible contrast between the areas is reduced and light transmission through the coated panel is increased.
[0008] The present invention also includes a method for making an interactive information device comprising forming a reduced contrast, increased light transmitting, conductively coated panel and optically bonding the conductively coated panel to an electro-optic display for displaying information when electricity is applied thereto. The conductively coated panel is formed b providing a transparent substrate having first and second surfaces, applying a transparent conductive layer on at least one surface of the substrate in a predetermined pattern such that there is at least one area having a conductive layer thereon and a second area without a conductive layer on that one substrate surface, and applying a transparent layer of metal oxide overlying the one and second areas of that one substrate surface whereby visible contrast between the one area and second area is reduced and light transmission through the coated panel is increased.
[0009] In other aspects, the method includes applying a transparent, conductive layer on the other of the first and second surfaces of the substrate in a predetermined pattern such that there is at least one area having a conductive layer thereon and a second area without a conductive layer and applying a transparent layer of metal oxide overlying the one and second areas of the other substrate surface.
[0010] The transparent metal oxide layers may be applied by physical vapor, deposition coating such as sputtering or evaporation coating white the transparent metal oxide layer or layers may be applied by a wet chemical deposition process such as spin coating, roll coating, meniscus coating, dip coating, spray coating or angle dependent dip coating. The dip coating or angle dependent dip coating includes dip coating the substrate having the transparent, conductive layers thereon in a precursor solution for silicon dioxide such that the transparent layers of metal oxide are applied to both surfaces of the substrate simultaneously. The method also includes applying a conductive electrode pattern over each of the respective surfaces of the substrate after application of the transparent conductive layers and prior to application of the transparent metal oxide layers. The transparent conductive layers and conductive electrode patterns may be cured by baking at a predetermined temperature for a predetermined time.
[0011] The present invention therefore provides an improved conductively coated panel for use in transparent, interactive input devices which both reduces visible contrast between areas coated with conductive layers and areas not coated with conductive layers while increasing light transmission through the coated panel. The coated panels are, therefore, especially useful in interactive devices such as with electro-optic displays for displaying information when electricity is applied thereto.
[0012] These and other objects, advantages, purposes and features of the invention will become more apparent from a study of the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a plan view of a conventional panel for an interactive device having both conductively coated and non-conductively coated areas on one surface of the substrate;
[0014] FIG. 2 is a sectional side elevation of a conductively coated panel in accordance with the present invention including a patterned, conductive thin film and an outermost film of metal oxide deposited thereover on each surface of the panel; and
[0015] FIG. 3 is a flow diagram of a preferred method of the present invention for making the conductively panel/interactive information device of FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] More specifically, and as shown in FIG. 2 , the invention relates to an improved, reduced contrast, increased transmission conductively coated panel 60 comprising a transparent substrate 10 having a first surface 12 and a second surface 14 . Substrate 10 , may be transparent glass, such as soda lime glass, or, may be an optical plastic comprising as conductively coated cyclic olefin copolymer plastic substrate as disclosed in U.S. patent application Ser. No. 09/946,22S, filed Sep. 5, 2001, entitled IMPROVED PLASTIC SUBSTRATE FOR INFORMATION DEVICES AND METHOD FOR MAKING SAME, the disclosure of which is hereby incorporated by reference herein in its entirety. Such rigid plastic substrate may be formed from a cyclic olefin copolymer (COC) such as is available from Ticonca of Summit, under the trade name “Topas.” Cyclic olefin-containing resins provide an unproved material for a rigid, transparent conductively coated substrate suitable for use in an information display. The improved information display incorporating the improved plastic substrate is lightweight, durable, flex resistant, dimensionally stable and break resistant as compared to other, more conventional substrates.
[0017] A rigid plastic substrate can be formed by extrusion, casting or injection molding. When injection molding, is used such as when forming a substrate from a cyclic olefin copolymer (COC), a non-planar curved (spherical or multiradius) part can be formed, optionally with at least one, surface roughened (such as by roughening/patterning a surface of the tool cavity used for injection molding) so as to have a light-diffusing, anti-glare property.
[0018] A transparent, plastic substrate such as one formed from cyclic olefin polymer resin can be used to form a rigid panel or back plate for use in a resistive membrane touch device where the cyclic olefin panel functions as a transparent back plate for a flexible, conductive, transparent touch member assembly as is also described in U.S. patent application Ser. No. 09/946,228, filed Sep. 5, 2001, incorporated by reference above.
[0019] A transparent, conductive, patterned thin film such as indium tin oxide or doped tin oxide, such as Sb or F doped tin oxide, or doped zinc oxide) 20 is deposited in a predetermined pattern with coated and non-coated was on the first surface 12 of substrate 10 . Preferably, a second transparent, conductive, patterned thin film 30 (such as indium tin oxide or doped tin oxide, such as Sb or F doped tin oxide, or doped zinc oxide) is also deposited on the second surface 14 of substrate 10 also in a predetermined pattern with coated and non-coated areas. A first surface outermost film 40 comprises a transparent silicon dioxide film deposited on transparent conductive patterned film 20 . The preferred range of thickness of the silicon dioxide (SiO 2 ) film is about 600 to about 1400 Angstroms thick, most preferred about 800 to about 1200 angstroms thick. Silicon dioxide film 40 is at least about 600 Angstroms thick in those areas overlying conductive film 20 . The second surface outermost film 50 also preferably comprises a transparent silicon dioxide film deposited on transparent conductive patterned film 30 and may have the same or differing thickness as film 40 . Layers 40 and 50 have a refractive index at the Sodium D line of at least about 2.00 and less than about 2.2. Although metal oxides are preferred, the present invention encompasses use of non-metal oxide layers such as boron oxide or the like.
[0020] Other metal oxide materials may also be used for layers 40 and 50 including tantalum oxide, zirconium oxide, titanium dioxide, tungsten oxide, or similar transition metal and non-transition metal oxides. Such materials would be used in thicknesses within the mar of about 100 to about 50,000 Angstroms. For example, for a metal oxide, layers 40 , 50 preferably are at least about 500 Angstroms to about 10,000 Angstroms thick in those areas overlying conductive films 20 or 30 .
[0021] Multilayer stack 20 reduces glare from light incident, thereon for direction X and multilayer stack 30 reduces glare from light incident thereon for direction Y. Silicon dioxide (SiO 2 ) layers 40 and 50 increase visible light transmission through panel 60 (that typically comprises a transparent glass substrate) as compared to uncoated glass by at least about 1.5% T; and preferably by at least about 4% T; and most preferably by at least about 6% T.
[0022] Light transmission through improved reduced-glare conductive coated panel 60 is at least about 85% T; more preferably at least about 90% T, and most preferably at least about 95% T (transmission measured using an integrating sphere across the visible spectrum). Optical inhomogeneity is reduced between the transparent conductively coated regions and the non-coated regions rendering these delineation regions essentially visually indistinguishable by a viewer so that there is no substantial contrast apparent when viewed in reflected light.
[0023] In some forms of the invention, it may be useful to incorporate a reduced glare, conductively coated panel haying increased visible light transmission and suitable for use as a touch screen, digitizer panel or substrate in an information display and incorporating one or more thin film interference layers forming a thin film stack on opposite surfaces of a substrate such as that described herein and a transparent electrically conductive coating on the outer most layer of one or both of the thin film stacks such as described in U.S. patent application Ser. No. 09/883,654, filed Jun. 18, 2001, now U.S. Pat. No. 6,878,240, issued Sep. 7, 2004, entitled ENHANCED LIGHT TRANSMISSION CONDUCTIVE COATED TRANSPARENT SUBSTRATE AND METHOD FOR MAKING SAME; the disclosure of which is hereby incorporated, by reference herein.
[0024] In some forms of the present invention, it may also be useful to incorporate a flexible, transparent, conductively coated layer with a rigid, transparent, conductively coated substrate suck as that described herein to form an interactive information device and to include spacer members or dots as described in U.S. patent application Ser. No. 09/954,139 filed Sep. 17, 2001, now U.S. Pat No. 6,627,918, issued Sep. 30, 2003, entitled SPACER ELEMENTS FOR INTERACTIVE INFORMATION DEVICES AND METHOD FOR MAKING SAME, the disclosure of which is incorporated by reference herein as set forth above. Such an assembly includes an improved process and materials for producing uniformly dispersed, consistent, durable, essentially non-visible, fixed substrate-interpane-spacer elements (for example “spacer dots”) for spacing opposing conductive surfaces of the flexible top sheet and rigid bottom sheet or substrate of such an interactive information device.
[0025] Preferably, at least layers 40 and 50 are deposited by wet chemical deposition (such as disclosed in U.S. Pat. No. 5,725,957. Varaprasad et al. etc or such as disclosed by U.S. Pat. Nos. 5,900,275; 5,838,483; 5,604,626; 5,525,264; and 5,277,986 all commonly assigned to Donnelly Corporation of Holland, Mich., which are all incorporated by reference herein in their entireties). For example, a preferred precursor solution comprises about 18.75% tetraethylorthosilicate about 2.23% acetic anhydride, about 3.63% water, about 0.079% phosphoric acid (85% acid in aqueous solution), about 0.91% 2,4-pentanedione, about 1.24% 1-pentanol, about 19.38% ethyl acetate, about 15% ethanol, about 17.5% methanol and about 21.25% acetone. (all component concentrations are expressed as weight percentages of the total weight of the solution). This equates to a concentration of tetraethylorthosilicate precursor, expressed as equivalents of silica, of about 5.4%.
[0026] The preferred process, and as shown in FIG. 3 , for the manufacture of digitizer panels starts with using conventional glass cleaning techniques for the preparation of the raw glass lite that typically is provided as a sheet or panel of dimension typically four (4) inches diagonal or greater. Lites can be processed in the bent or fiat product configuration, and lites can be processed in the final product size, or in what is known as the stocksheet configuration allowing for the subsequent cutting from and manufacture of multiple touch devices from one lite. Prior to the deposition of the transparent conductive thin film on the second surface, a pattern of mask material is applied to the raw glass using a silk screen coating method, 325-mesh stainless steel screen. This allows for the removal of the thin film conductor, indium tin oxide for example, following the deposition of the conductive thin film. The conductive thin film could also be removed in the required configuration using a post deletion method such as by laser ablation or post chemical etching with photolithography. The conductive thin film, preferably indium tin oxide, is then deposited on the second surface of the lite, preferably by the sputtering physical vapor deposition technique or evaporation physical vapor deposition technique. A thick film conductive electrode pattern, typically a silver glass frit such as Dupont 7713, is then applied using a silk screen coating method, 325 stainless steel mesh silk screen with, glass fit as requited based on the digitizer design. The thin film conductor and the thick conductor are then cured using a conventional baking process, such as 480 degrees C. for 60 minutes. The thin film conductor may be chemically reduced in an inert forming gas curing environment. The substrate is then washed using conventional glass washing procedures. Prior to the deposition of the transparent conductive thin film on the first surface, a pattern of a mask material is applied to the raw glass using a silk screen coating method, 325-mesh stainless steel screen. This allows removal of the thin film conductor, indium tin oxide for example, following the deposition of the conductive film. The conductive thin film could also be removed in the required configuration using a post deletion method such as by laser ablation or chemical etching such as with photolithography or, with a screened chemical etch paste (typically an acid based paste). The conductive thin film, indium tin oxide, is then deposited on the first surface of the lite, preferably by the sputtering physical vapor deposition technique or evaporation physical vapor deposition technique. A thick film conductive electrode pattern, typically a silver glass fit such as Dupont 7713 is then applied using a silk screen coating method, 325 stainless steel mesh silk screen with glass fit as required based on the digitizer design. The thin film conductor and the thick film conductor are then cured using a conventional baking process, such as 480 degrees C. for 60 minutes, followed by a chemical reduction in an inert forming gas at 290 degrees C. for 30 minutes. The double sided conductively coated substrate is then washed using conventional glass washing techniques. Both the first and second surfaces are then coated with a silicon dioxide thin film using a dip coating technique. The double-sided silicon dioxide film is then cured using a conventional baking process, such as 480 degrees C. for 60 minutes. The thin film conductor under the silicon dioxide may be chemically reduced in an inert forming gas curing environment. The lites are then cut to final digitizer dimensions using conventional glass cutting, techniques. A flexible electric connector is electrically connected to the complete assembly for attachment to the information device. This device may be optically bonded to the first surface of a liquid crystal display. The resulting product is the complete transparent digitizer interactive device.
[0027] While several forms of the invention have been shown and described, other forms will now be apparent to those skilled in the art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention, which is defined by the claims which follow.
|
A method and product produced by the method for forming an interactive information device with a conductively coated panel includes forming a reduced contrast increased light transmitting, conductively coated panel by providing a transparent substrate and applying a transparent, conductive layer on at least one surface of the substrate in a predetermined pattern with at least one area having a conductive layer thereon and a second area without a conductive layer. The method further includes applying a transparent layer of a metal oxide such that the metal oxide layer, such as silicon dioxide, overlies both areas whereby visible contrast between the areas is reduced and light transmission through the coated panel is increased. The coated panel is then attached to an electro-optic display for displaying information when electricity is applied thereto.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a 35 U.S.C. §§371 national phase conversion of International application PCT/EP2006/008644, filed Sep. 5, 2006, which claims priority of Germany Patent Application No. DE 10 2005 043 898.9, filed Sep. 14, 2005, and U.S. Provisional patent application 60/750,913, filed Dec. 15, 2005, the disclosures of which have been incorporated herein by reference. The PCT International Application was published in the English language.
TECHNICAL FIELD
The present invention relates to a window arrangement and to a method for enlarging a window area, as well as to the use of the window arrangement in an aircraft.
BACKGROUND TO THE INVENTION
In present-day passenger aircraft, due to structural restrictions, it is often only possible to have very small windows. One of the limiting factors that result in restrictions in the width of aircraft windows relates, for example, to air conveyance lines that usually lead from the cabin floor along the fuselage to the fuselage roof, in order to, in this way, supply passengers with fresh air. In this arrangement the air supply pipes are led along between two transverse supports. In this intermediate region between two transverse supports, in addition the window apertures have to be placed so that the supply lines and the windows have to share the same area. However, since as a result of structural restrictions the distance between transverse supports cannot be increased at will, the aircraft windows are of an extremely small design.
One solution to this problem can consist of reducing the size of the air conveyance lines. However, such a reduction in size is associated with negative characteristics because the conveyed air generates air flow noise and at the same time loses pressure as a result of insufficiently large lines. Any noise reduction by using very wide air conveyance devices is also difficult because, conversely, the size of the windows has to be reduced. Furthermore, the height of the aircraft windows is limited by the longeron spars of the fuselage structure.
Normally, aircraft window arrangements are designed as a double window system. EP 0 936 138, U.S. Pat. No. 5,884,865 and EP 0 846 616 disclose methods for installation of an aircraft window. In this arrangement an exterior primary window is affixed to the exterior skin of a fuselage, and a secondary interior aircraft window is affixed to the interior of the fuselage. The intermediate space is often used to provide sound absorption and insulation in relation to ambient pressure and ambient temperatures. Due to the cold exterior ambient temperatures the exterior primary window is often very cold so that the air in the interior, between the primary and the secondary window panes, condenses on the exterior primary window pane. In order to prevent this the interior space can be vented or condensation can be prevented by way of condensation channels.
EP 1 510 454 discloses a fuselage region that discloses insulation and air lines in a particular arrangement. To provide adequate space for the windows the air lines are routed around the window apertures in an extremely complex manner. However, as mentioned in the introduction, as a result of the reduction in size of the line cross-section of the air line an unpleasant airflow noise can arise. In particular, the solution offered in EP 1 510 454 does not provide a possibility of effectively increasing the size of the windows.
U.S. Pat. No. 6,601,799 discloses a system for increasing the interior secondary window area in an aircraft. In this arrangement a larger cutout is created on the interior. This provides a larger secondary window, without, however, effectively enlarging the outer primary window area.
EP 0 713 559 B1 discloses the body of a terrestrial vehicle or an aircraft, which for the purpose of supporting the cover or ceiling pillar provides supports from structural, stable, load-bearing, transparent or translucent material.
PRESENTATION OF THE INVENTION
Among other things, it may be an object of the present invention to provide a window arrangement for enhancing passenger comfort.
According to an exemplary embodiment of the invention a window arrangement (in particular for enlarging a window area) of an aircraft is provided, comprising at least one first installation element. The at least one installation element is designed to convey fluids and at the same time comprises a transparent region. In this arrangement, the transparent region of the at least one first installation element covers a first window region such that light waves in the visible spectrum can be let through.
According to a further exemplary embodiment of the invention a method for enlarging a window area of an aircraft is provided, wherein in a first step at least one first installation element is installed, wherein the at least one first installation element comprises a first transparent region, and the transparent region covers at least one first window region such that light waves in the visible spectrum can be let through.
According to still another exemplary embodiment of the invention an aircraft is created that comprises a window arrangement for enlarging a window area according to an exemplary embodiment of the invention.
According to another exemplary embodiment of the invention a window arrangement according to an exemplary embodiment of the invention is used in an aircraft.
The present invention may provide the option of significantly enhancing passenger comfort in that the window area may be enlarged, thus possibly providing passengers with a clearly improved view. Up to now the size of aircraft windows was limited by the space required between two transverse supports. By designing a visually transparent installation element according to an exemplary embodiment of the invention, there may be the option of creating the complete region between two transverse supports as a window area in that the first window region and the transparent region of the first installation element are at least in part one on top of the other, instead of one being arranged beside the other as has exclusively been the case up to now. Apart from enlarging the window area and thus enhancing a passenger's view and comfort it may also be possible to design fluid conveyance more advantageously by the first installation element because airflow noises due to the narrow design of air ducts may be avoided by the now possible increase in the cross section of the first installation element.
Within the context of this application the term “fluid” refers in particular to any fluid or any gas as well as corresponding fluid-gas mixtures, in particular made of optically transparent material. Thus, the invention comprises in particular at least partly transparent gas supply lines (e.g. for conveying cabin air), fluid supply lines (for example for providing fresh water in aircraft toilets), etc.
Within the context of this application the term “installation element” refers in particular to any component that is suitable for installation in a higher-order system, for example for installation in an aircraft.
Exemplary fields of application of the invention include any type of means of transport, in particular aircraft, dirigibles or airships, buses, trains, passenger motor vehicles, lorries, ships, etc.
Transparent materials as such are known to the average person skilled in the art; they are, for example, disclosed in the Japanese printed publication JP 09072761 as well as in US 2004/0062934 which are hereby incorporated herein by reference. In JP 09072761 a glass panel can be coated with titanium oxide so that a linear translucency of 50% is possible. In contrast to this, US 2004/0062934 discloses a visually transparent and structural laminate structure. Light waves in the visible spectrum may be let through across a wide light-wave range. Furthermore, the material may easily be formed so that complex shapes may be created. Such materials may also be used within the context of the present invention.
According to a further exemplary embodiment of the present invention the window arrangement or window system comprises at least a second installation element, wherein the second installation element comprises a transparent region which covers at least one first window region such that light waves in the visible spectrum can be let through.
According to a further exemplary embodiment the second installation element can be selected from an element from the group consisting of ribs, braces and supporting structures. Modern materials may make it possible to create transparent structures which are nonetheless very capable in terms of their load-bearing ability. This may make it possible to create transparent transverse supports and longitudinal supports. Adjacent aircraft windows that up to now have been situated apart from each other may be joined to form one large aircraft window. Furthermore, it may be possible to combine not only two but a plurality of aircraft windows so that a nearly complete transparent fuselage or a large panorama window may be designed. Since the intermediate region between the longitudinal supports and transverse supports may be completely utilized due to transparent installation elements, there may also be the option of creating an optimised structure by using narrower transparent longitudinal supports and transverse supports that are instead arranged at smaller distances from each other. This may make it possible to save weight and costs.
According to a further exemplary embodiment of the present invention the at least one second installation element can be designed for lining or encasing the cabin interior. In this way, by way of transparent materials or installation elements, completely new design options for the cabin layout might arise. For example, modern and lighter design options and an improved feeling of space for passengers may be created.
According to a further exemplary embodiment the at least one first installation element, comprises at least one fluid inlet and at least one fluid outlet. Due to there no longer being any spatial restrictions because of the transparent first installation element there may be an option of optimally arranging at least one or a plurality of fluid inlets and/or fluid outlets so that circulation in the fluid system may be significantly improved. In this way, for example, the energy for operating a fluid system, or the flow noises, may be significantly reduced.
According to a further exemplary embodiment of the present invention the window arrangement further comprises a first window region that is affixed or attached to and/or in an aircraft skin such that the interior of the aircraft is insulated, thermally and stably when subjected to pressure, from an exterior atmosphere.
In a further exemplary embodiment of the present invention the first window region is integrally and in one piece (for example made in one piece and/or made from one material) designed with the transparent region of the at least one first installation element and/or with the transparent region of the at least one second installation element. In this way complex constructions, such as for example double-window constructions, may be avoidable. A single window pane may be sufficient to provide thermal insulation and stability when subjected to pressure in relation to the exterior atmosphere, as a result of which significant costs and weight may be saved.
According to a further exemplary embodiment the at least one first installation element, and/or the at least one second installation element comprise/comprises transparent current conductors and/or optical wave guides for transmitting signals. With the use of modern materials signal transmission may be arranged by way of transparent lines. In this way necessary signal connections or current connections may also be routed by way of window regions of the aircraft, and further space for aircraft windows may be created.
According to an exemplary embodiment of the invention the at least one first installation element in the transparent region comprises at least one vent hole or vent drill for venting the first window region. This may create a system for preventing condensation, without the need for additional installation parts. By simple boreholes in the first fluid-conveying installation element, by way of the connected venting of the first window region, the window pane may be heated or dried, as a result of which an extremely lightweight and economical method for preventing condensation may be provided.
According to a further exemplary embodiment the window arrangement comprises a second window region, wherein between the first window region and the second window region transparent first installation elements and/or transparent second installation elements extend. This may make possible an unlimited design of transparent areas in a fuselage without thereby weakening the structure. In this way long panorama windows may be created so that the view which passengers enjoy and passenger comfort in general may be enhanced.
The embodiments of the device also apply to the method and to the aircraft, as well as to the use, and vice-versa.
The window arrangement or window assembly according to an exemplary embodiment of the invention, including the above-mentioned exemplary embodiments, may provide options of enhancing the aircraft's comfort by opening up the view for passengers, while at the same time creating less complex devices. With the use of transparent materials there may be no restrictions concerning the covering of installation elements, several situated one on top of the other. With superposition of several different layers of transparent installation elements, each of which may carry out different types of functions, any desired window arrangements may be possible. Furthermore, there may no longer be any restrictions relating to structural weakening or covering up by installation elements. This may also result in an advantage of creating simpler constructions for window arrangements because nevertheless a stable structure can be created, as a result of which, overall, lighter-weight cost-saving solutions may be created.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, for further explanation and to provide a better understanding of the present invention, exemplary embodiments are described in more detail with reference to the enclosed drawings. The following are shown:
FIG. 1 a design of a window arrangement;
FIG. 2 a window arrangement with windows that are stretchable in height;
FIG. 3 a diagrammatic view of the interior design;
FIG. 4 a window arrangement according to an exemplary embodiment of the present invention;
FIGS. 5 a - d a diagrammatic view of various exemplary embodiments of the first installation element;
FIG. 6 a diagrammatic view of the interior design according to the present invention;
FIG. 7 a diagrammatic view of a window arrangement with the use of second installation elements;
FIG. 8 a three-dimensional view of a cabin layout;
FIG. 9 a three-dimensional view of a cabin layout with a window arrangement according to the invention and with a conventional window arrangement;
FIGS. 10 to 13 a three-dimensional view of a cabin layout with the window arrangement according to the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Identical or similar components in different figures have the same reference signs.
The illustrations in the figures are diagrammatic and not to scale.
FIG. 4 shows a window arrangement for enhancing a window area of an aircraft, according to an exemplary embodiment of the present invention. Above a window element 2 , 7 installed in the fuselage 1 there is a first installation element 5 according to an exemplary embodiment of the invention, which installation element 5 comprises a transparent region that covers at least part of the window aperture 2 , 7 . In the first installation element 5 fluid can be conveyed, and space can be saved by arranging said first installation element above the window. A transparent current conductor and/or optical wave guide 8 is arranged in the window element.
FIG. 1 shows a conventional window arrangement in a passenger aircraft. The air conveyance lines 5 are routed around the window apertures 2 , 7 in the fuselage 1 . In order to reinforce the fuselage 1 , at specified spacing, ribs 3 and stringers 4 are in place, which for reasons of structural stability should not exceed a certain distance from each other. This results in an extremely small useful area in which a window surface 2 , 7 can be installed.
FIG. 2 shows an existing option of increasing the window area at least as far as its height is concerned. The fuselage 1 shows window regions 2 , 7 which, due to the installation of the ribs 3 and the stringers 4 , can only be increased in height.
FIG. 3 shows a cross section of a conventional window arrangement. On the fuselage 1 , a first window area 2 , 7 is installed on the outside. On the inside of the aircraft cabin there is a second window area. Between the respective window areas there are vented regions 6 to provide insulation and prevent condensation on the cold exterior first window area 2 , 7 . At the respective margins the restricting stringers 3 are shown, wherein the air conveyance lines 5 are arranged between the stringers 3 and the window aperture 2 , 7 . This shows that it is practically impossible to increase the width of the window area. Any reduction in the size of the air conveyance lines 5 would disadvantageously increase airflow noises to such an extent that passengers would find them intrusive.
FIG. 4 shows a window arrangement, according to an exemplary embodiment of the invention, for enlarging a window area of an aircraft. As already described, a fuselage 1 is shown which is reinforced by ribs 3 and stringers 45 . Between the stringers and the ribs 3 , 5 there is the window area 2 , 7 which is covered by the transparent region of the first installation element 5 . In this way passengers can comfortably see through the transparent region of the first installation element 5 and through the first window area 2 , 7 . Because of the likewise freely designable size of the first installation element 5 , more fluid can be conveyed with significantly less noise so that intrusive flow noises and at the same time flow losses can be prevented.
FIG. 5 shows various embodiments of the first installation element 5 . For example, in the first embodiment a first installation element 5 can comprise an air inlet and an air outlet. For better distribution or better circulation there is also the option of providing two or a plurality of air inlets and air outlets so as to significantly optimize the characteristics of the flow. The shape of the first installation element 5 can also be designed so as to be variable.
FIG. 6 shows a view of section A-A from FIG. 5 , which section shows a diagrammatic view of the window arrangement according to an exemplary embodiment of the invention. The diagram shows that while the ribs 3 restrict the space of the window size, the window area nevertheless extends across the region of the air conveyance line 5 , because both elements, the first installation element 5 and the window area 2 , 7 , are placed one above the other so that they can utilize the entire space between the two transverse supports 3 .
FIG. 7 shows a further option for enlarging the window area in an aircraft. By using transparent transverse supports 3 , two adjacent window areas 2 , 7 , 8 can be brought together so that a large panorama window 10 is created. This becomes possible in that the second attachment element 9 , which for example comprises transparent transverse supports 9 or structural elements 9 , is of transparent design so that it can cover the window area without impeding the view.
FIG. 8 shows a customary cabin layout of a passenger aircraft with small aircraft windows.
FIGS. 9-13 show embodiments with the window arrangement according to an exemplary embodiment of the invention, for enlarging the window areas in an aircraft. As a result of the significantly larger exterior windows 2 , 7 passengers experience an optimal feeling of spaciousness, which significantly enhances passenger comfort. The difference is particularly evident in FIG. 9 . When compared to the conventional aircraft window arrangements 2 , 7 , a significant enlargement can be achieved with the arrangement, according to an exemplary embodiment of the invention, of the windows 2 ′, 7 ′.
In addition it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, it should be pointed out that features or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims are not to be interpreted as limitations.
|
A window arrangement is provided for enlarging a window area in an aircraft. The window arrangement includes, but is not limited to at least one first installation element. The at least one first installation element is designed to convey fluids, and furthermore includes, but is not limited to a transparent region which covers a first window region such that light waves in the visible spectrum can be let through.
| 1
|
BACKGROUND OF THE INVENTION
The invention relates to weft insertion systems for use in travelling-wave looms, and more particularly to an endless-chain arrangement for feeding a plurality of weft threads from a plurality of bobbins to the individual weft inserters.
In known systems of this type, a first endless chain carries a plurality of spaced weft inserters around an elongated path that is curved at both ends, and a second endless chain carries a plurality of winding units around an oval path coinciding at one end with the curvature of the end path of the first chain. The winding units are individually adapted to present weft threads from an associated plurality of bobbins to the successive weft inserters during simultaneous movements of the first and second chains.
Typically, the oval path of the second chain is defined by a guiding surface of an elliptical track. A common drive member is coupled in parallel to a pair of spider elements, which engage a length of the first and second chain to ideally drive them in synchronous relation.
In practice, several disadvantages have manifested themselves with respect to the second chain, both with regard to its manner of driving by the common drive means and with regard to the mounting thereto of the associated winding heads. In particular, because of the relatively imprecise region of contact of the spider member and the successive links of the second chain, the second chain tends to move out of phase with the first chain the which it is ideally synchronized. This, in turn, leads to stresses and breakage of the weft threads. Additionally, in such arrangements the individual winding heads are affixed to the second chain via the elongated pins that interconnect the successive links of such chain. As a result, replacement and exchangeability of the winding heads is extremely difficult.
Another disadvantage of such prior art arrangements is that the adherence of the second chain to the guide surface of the associated oval track is accomplished solely by rollers disposed on the chain on one side of such track. The resulting small contact surface between the chain and the track results in instabilities during the movement of the second chain, and further contributes to stresses and breakage of the weft threads.
SUMMARY OF THE INVENTION
Such disadvantages, manifested by weft insertion systems exhibiting a second endless chain for positioning a plurality of winding heads in registration with a succession of weft inserters on a first endless chain, are overcome by the facilities of the present invention. Illustratively, the second endless chain includes a plurality of mutaully spaced, rigid carrier members each exhibiting a beveled contact surface for engagement with the associated spider of the common drive means.
Each such carrier member includes portions which extend on transversely opposite sides of the oval guide rail for supporting rollers that engage guide surfaces on both sides of such rails. The rollers disposed on one side of such guide rail are constantly urged, via spring action, against the guide surface, so that the second chain is rigidly supported against the rail to avoid the instabilities in travel exhibited by the prior art.
Additionally, each of the winding units in removably secured to one of the carrier members, rather than being permanently affixed to elongated pins that connect the successive links of the chain, as in the prior art. In one illustrative arrangement, a recess is provided in each carrier member, and a spring-loaded pawl is supported on the carrier member to releasably hold the winding head in the recess.
The mutually spaced carrier members of the second chain are interconnected by links which are connected to the adjacent end of the carrier member by elongated pins. The rollers associated with one guiding surface of the oval track are supported on the successive elongated pins.
The presence of the beveled contact surfaces on the successive rigid carrier members provides constant and unyielding engagement with the successive arms of the driving spider, resulting in a reliable and constant movement of the second chain in synchronism with the first chain.
BRIEF DESCRIPTION OF THE DRAWING
The invention is further set forth in the following detailed description taken in conjunction with the appended drawing, in which:
FIG. 1 is a stylized plan view of a portion of a travelling-wave loom having a first endless chain carrying successive weft inserters and a second endless chain carrying successive winding heads for presenting individual weft threads to aligned ones of the weft inserters;
FIG. 2 is an elevation view of the arrangement of FIG. 1, with certain details removed for purposes of clarity;
FIG. 3 is a plan view of an endless chain adapted to carry the successive winding heads in FIG. 1 and constructed in accordance with the invention;
FIG. 4 is a fragmentary elevation view, in section, illustrating details of a particular carrier member and associated structures for guiding the carrier member along inner and outer guide surfaces of an oval track, together with facilities disposed on such carrier member for removably supporting a winding head which is not explicitly depicted in the figure;
FIG. 5 is an elevation view, partly in section, illustrating facilities for synchronously driving a pair of superposed endless chains that support the weft inserters and the winding heads, respectively, the figure also illustrating bobbins and associated guiding structures associated with the winding heads;
FIG. 6 is a side view of the arrangement of FIG. 4;
FIG. 7 is a bottom view of the arrangement of FIG. 4, with certain details removed for clarity;
FIG. 8 is a bottom view similar to FIG. 7, illustrating an alternative technique for continually urging one set of rollers affixed to the carrier member against the adjacent guide surface of the associated track;
FIG. 9 is an elevation view, similar to FIG. 4, showing an alternative technique for guiding a carrier member along the adjacent guide surface of the associated track.
FIG. 10 is a fragmentary view illustrating the lower portion of the arrangement of FIG. 5 and indicating how the upper portion of a winding head is secured to the carrier member; and
FIG. 11 is a view taken along line 11--11 of FIG. 10.
DETAILED DESCRIPTION
Referring now to the drawings, FIGS. 1 and 2 illustrate a portion of a travelling-wave loom 101 wherein a first endless chain 8 extends in a generally longitudinal path, guided by a suitable track associated with a machine frame 2. The ends of the elongated track of the chain 8 are convexly curved. A plurality of conventional weft inserters 9, 9 are disposed in spaced relation along the chain 8 in a conventional manner.
The endless chain 8, which is driven by a suitable spider member to be described below, proceeds beneath and parallel to a second endless chain 10 which is guided along an upper rail 3 (FIG. 2) in an oval path that coincides at one end with the curvature of the path followed by the weft insertion chain 8, in a conventional manner. As described below, the chain 10 is adapted to carry a plurality of facilities for individually feeding weft threads from a corresponding plurality of bobbins to the weft inserters 9 on the underlying endless chain 8.
In accordance with the invention and as shown best in FIG. 3, the second chain 10 includes a plurality of spaced rigid carrier members 12, which are provided with beveled contact surfaces 21 for engagement with the arms of a spider member 7 keyed to a driveshaft 5 for advancing the successive carrier members 12 along suitable guiding paths of the upper plate 3 (FIG. 4).
The successive carrier members 12 of the chain 10 are interconnected via pins 15 (FIG. 3) with a plurality of links 11; such links 11 interconnect the ends of longitudinal portions 102 of the members 12 on vertically opposite surfaces 103, 104 (FIG. 4) of the longitudinal portion 102.
Each carrier member is also provided with a portion 106 which extends transversely on opposite sides of respective inner and outer guide surfaces 13, 14 of the oval track 3. The longitudinal portion 102 and the associated links extend from the transverse portion 106 adjacent the outer guide surface 14 of the track 3.
In order to provide a secure and accurate guiding of the carrier members 12 along the track 3, each such carrier member is provided with a plurality of rollers 16 for rolling engagement with the outer guide surface 14 of the track 3. Each carrier member 12 is also provided with at least one additional roller 17 for rolling engagement with the inner guide surface 13 of the track 3.
For this purpose, a pair of the rollers 16 are mounted on each of the interconnecting pins 15 associated with opposite ends of the longitudinal member 102 in the manner shown in FIG. 3, while the opposite roller 17 is supported on a pin 18 that is affixed to the transverse portion 106 of the carrier member 12. The roller 17 is constantly urged against the associated guide surface 13 by spring-loaded means discussed below in connection with FIG. 7.
As shown best in FIG. 5, the spider member 7 is ganged with a similiar spider member 6 on a common rotatable shaft 5 which is geared to a common drive mechanism 39, whereby the endless chains 8 and 10 can be driven in synchronism along the paths indicated in FIGS. 1 and 2. As shown in FIG. 3, the beveled rigid surfaces 21 of the carrier members 12, cooperating with the arms of the spider member 7, assure a reliable and slip-free drive of the chain 10 relative to the chain 8 to assure the desired synchronism therebetween.
Each of the carrier members 12 of the chain 10 is adapted to removably support a winding head 25 (FIG. 5) positioned to present an associated weft thread opposite a weft inserter 9 carried on the lower chain 8. The structure of winding head 25 and the associated insertion structure of the inserter 9 are conventional in nature and are described, e.g., in U.S. Pat. No. 3,732,896, issued to Jekl et al. For example, each carrier member 12 is adapted to support a separate bobbin 32 and associated guiding structures that supply the weft thread 33 to the associated winding head 25. Such auxiliary structures, which includes a balloon limiter 34, a plurality of guides, 35 and a brake 36 mounted on a curved holder 31 which is affixed to the longitudinal portion 102 of the carrier member 12 from the brake 36, the weft thread extends from guide 37 on the carrier member 12 and a pair of guides 38 carried on a main portion 150 of the winding head 25 to the inserter 9 as shown. The winding head also includes an upper holder portion 24 which is connected to the main portion 150 via members 151 for securing the winding head 25 to the lower portion of the carrier member 12 in the manner described below. In addition, the winding head 25 includes a lifter 152 affixed to the lower end of the main portion 150, and a follower 153 supported on the lifter 152. During the movement of the winding head, the follower 153 is urged downwardly against a fixed cam 155 via the force of springs 154; the springs surround the elements 151 and extend between the bottom of the holer 24 and the top of the main portion 150.
In order to secure the holder 24 to the carrier member 12, and as best shown in FIGS. 10 and 11, the holder 24 is received in a recess 28 disposed in a lower portion of the transverse member 106 of the carrier member 12. The recess 28 is bounded at one end by stop members 23, which may be integral with the transverse member 106. In this position, the holder 24 may be wedged against the adjacent stop member 23 by one end 27 (FIG. 11) of a pawl 26. The pawl 26, in turn, is pivotally mounted on a pin 29 that is secured in a central recess 111 of the transverse member 106. The pawl 26 is urged via a spring 30, into the recess 28 so that a front surface 161 of the pawl end 26 frictionally engages an oblique surface 162 of the holder 24, as shown in FIG. 10. The pawl surface 161 forms a small acute angle a with the oblique surface 162 in the operative position, so that an edge 163 of the pawl frictionally engages the surface 162 to maximize the wedging force on the holder 24, thereby precluding inadvertent release of the holder from the transverse member 106. In order to disengage the holder from the carrier member, a free end 112 of the pawl may be pushed down against the force of the spring 30 to disengage the edge 163 from the surface 162.
Referring now to FIG. 7, one technique for urging the roller 17 against the associated guide surface 13 of the track 3 is illustrated. The pin 18 is made eccentric relative to the center of rotation of the roller 17, and a hair-pin spring 19 is associated with the roller 17, with one end 113 of such spring engaging the pin 18 and the other end being secured to an auxiliary pin 20 mounted on the transverse member 106 of the carrier 12. Because of the eccentricity of the pin 18, the spring 19 tends to rotate it in a direction to force the roller 17 against the guide surface 13, thereby simultaneously drawing the opposed rollers 16 against the outer guide surface 14 of the track 3.
An alternative method of urging the roller 17 against the guide surface 13 is shown in FIG. 8. In this construction, one end of a lever 40 is pivotally mounted to a pin 42 supported by the transverse member 106, and the other end of the lever 40 is provided with a recess 114 for receiving one end of a spring 43 whose other end is suitably secured to the transverse member 106. The lever 40 has a central aperture 41 for receiving the roller 17, which is supported on a concentric pin 116. The force of the spring 43 is effective to exert a constant pressure, on the surface 13, of the roller 116.
If desired, two superposed rows of the rollers 16 may be associated with each carrier member 12. For this purpose, as shown in FIG. 9, a pair of the rollers 16 are disposed in spaced relation to the opposed longitudinal surfaces 103, 104 of the longitudinal member 102 associated with the carrier 12. As in FIG. 4, the rollers 16 of FIG. 9 are mounted directly on the elongated pins 15 that interconnect the ends of the links 11 with the longitudinal carrier member 102. In order to accommodate the spaced superposed rollers 16, the outer guide surface 14 of the upper track 3 is elongated in the manner shown in FIG. 9. In all other respects, the arrangements of FIGS. 4 and 9 are identical.
In the foregoing, an illustrative arrangement of the invention has been described. Many variations and modifications will now occur to those skilled in the art. It is accordingly desired that the scope of the appended claims not be limited to the specific disclosure herein contained.
|
A travelling-wave loom is provided with a pair of endless chains which respectively carry a plurality of weft inserters and a plurality of winding units for feeding weft threads from associated bobbins to the weft inserters. The chain carrying the winding unit is formed from a plurality of spaced rigid carrier members interconnected by standard links. Each carrier member has a groove for removably receiving the winding head, and when in position a spring-loaded pawl affixed to the carrier member releasably secures the winding head in the groove of such carrier member. Such chain also carries transversely spaced sets of rollers which are individually supported on opposite sides of an oval guide rail. One of the roller sets is spring-loaded to maintain the carrier member in firm contact with the guide surfaces.
| 3
|
FIELD OF THE INVENTION
[0001] The present invention relates to a McPherson strut assembly for a motor vehicle. More particularly, the present invention relates to the orientation of the top mount of the McPherson strut assembly which allows for the use of common components on both sides of the vehicle.
BACKGROUND OF THE INVENTION
[0002] Strut-type suspension systems are well known in the motor vehicle industry. A telescopic strut normally incorporating a hydraulic damper is used as one of the locating members for the wheel of the motor vehicle. The most common form of a strut-type suspension is the McPherson strut suspension system. The McPherson strut assembly includes a coil spring located concentrically around the telescopic strut which is the shock absorber. The upper end of the McPherson strut assembly includes an upper mounting assembly which is mounted in a tower formed by the vehicle body at a position above the wheel arch of the vehicle.
[0003] The upper mounting assembly typically includes a rebound bumper protected by a dirt shield, an upper spring seat for properly positioning the coil spring of the McPherson strut assembly, a bearing which allows rotation of the piston rod with respect to a top mount which includes bolts which are utilized to secure the upper mounting assembly to the tower formed by the vehicle body.
[0004] As a result of the quest for standardization and the associated cost savings, it is desirable to design symmetrical parts. In the case of the upper mounting assembly, the rebound bumper, the dirt shield, the upper spring seat and the bearing are typically symmetrical components which can be used on both the right and left sides of the vehicle. The top mount, while being similar in design for the right and left sides of the vehicle, it is not a symmetrical component. While the top mount is not a symmetrical component, the identical component may be able to be used on the right and left hand sides of the vehicle if the orientation of the top mount can be specifically set to a first orientation when it is positioned on the right side of the vehicle and specifically set to a second orientation when it is positioned on the left side of the vehicle.
SUMMARY OF THE INVENTION
[0005] The present invention provides the art with a system including an orientation device which is capable of automatically aligning the top mount in the first position for the right side of the vehicle and in the second position for the left side of the vehicle. The system includes tooling which includes a first stationary stop for the right side of the vehicle and a second spring mounted stop for the left side of the vehicle.
[0006] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] FIG. 1 is an illustration of an automobile using the McPherson strut assemblies in accordance with the present invention;
[0009] FIG. 2 is a side view of one of the front suspension units that incorporate the McPherson strut assembly in accordance with the present invention;
[0010] FIG. 3 is an enlarged cross sectional view of the top mount assembly of the present invention with the orientation tooling engaged with the top mount; and
[0011] FIG. 4 is a top view of the top mount assembly and the orientation tooling illustrated in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0013] There is shown in FIG. 1 a vehicle incorporating a suspension system having the strut assembly in accordance with the present invention and which is designated generally by the reference numeral 10 . Vehicle 10 comprises a rear suspension 12 , a front suspension 14 and a body 16 . Rear suspension 12 has a transversely extending rear axle assembly (not shown) adapted to operatively support the vehicle's rear wheels 18 . The rear axle assembly is operatively connected to body 16 by means of a pair of shock absorbers 20 and a pair of helical coil springs 22 . Similarly front suspension 14 includes a transversely extending front axle assembly (not shown) to operatively support the vehicle's front wheels 24 . The front axle assembly is operatively connected to body 16 by means of a second pair of shock absorbers 26 and by a pair of shaped helical coil springs 28 . Shock absorbers 20 and 26 serve to dampen the relative motion of the unsprung portion (i.e. front and rear suspensions 12 and 14 , respectively) and the sprung portion (i.e. body 16 ) of vehicle 10 . While vehicle 10 has been depicted as a passenger car having front and rear axle assemblies, shock absorbers 20 and 26 may be used with other types of vehicles and/or in other types of applications such as vehicles incorporating independent front and/or independent rear suspension systems. Further, the term “shock absorber” as used herein is meant to be dampers in general and thus will include McPherson struts. Also, while front suspension 14 is illustrated having a pair of McPherson struts or shock absorbers 26 , it is within the scope of the present invention to have rear suspension 12 incorporate a pair of McPherson struts or shock absorbers 26 if desired.
[0014] Referring now to FIG. 2 , the front wheel assembly for vehicle 10 is illustrated in greater detail. Body 16 defines a shock tower 32 comprising sheet metal of vehicle 10 within which is mounted a McPherson strut assembly 34 which comprises a telescoping device in the form of shock absorber 26 , coil spring 28 and a top mount assembly 36 . McPherson strut assembly 34 including shock absorber 26 , coil spring 28 and top mount assembly 36 are attached to vehicle 10 using shock tower 32 . Top mount assembly 36 comprises a top mount 38 , a bearing assembly 40 and an upper spring seat 42 . Top mount 38 comprises an integral molded body and a rigid body member, typically made of stamped steel. Top mount assembly 36 is mounted to body 16 by bolts 48 . Bearing assembly 40 is friction fit within the molded body of top mount 38 to be seated in top mount 38 so that one side of bearing assembly 40 is fixed relative to top mount 38 and shock tower 32 . The second side of bearing assembly freely rotates with respect to the first side of bearing assembly 40 , top mount 38 and shock tower 32 .
[0015] The free rotating side of bearing assembly 40 carries upper spring seat 42 that is clearance fit to the outer diameter of bearing assembly 40 . A jounce bumper 50 is disposed between upper spring seat 42 and shock absorber 26 . Jounce bumper 50 comprises an elastomeric material which is protected by a plastic dirt shield 52 . A bumper cap 54 is located on shock absorber 26 to interface with jounce bumper 50 and plastic dirt shield 52 .
[0016] A lower spring seat 60 is attached to shock absorber 26 and coil spring 28 is disposed between upper spring seat 42 and lower spring seat 60 to isolate body 16 from front suspension 14 . Shock absorber 26 comprises a pressure tube 62 , a piston assembly 64 and a telescoping rod or piston rod 66 . While shock absorber 26 is illustrated as a mono-tube design, it is within the scope of the present invention to utilize a dual-tube shock absorber for shock absorber 26 . Also, while shock absorber 26 is illustrated in FIG. 2 , it is to be understood that shock absorber 20 may also include the features described herein for shock absorber 26 .
[0017] Prior to the assembly of McPherson strut assembly 34 into vehicle 10 , the pre-assembly McPherson strut assembly 34 is performed. Bumper cap 54 , jounce bumper 50 and dirt shield 52 are assembled to shock absorber 26 . Coil spring 28 is assembled over shock absorber 26 and positioned within lower spring seat 60 . Upper spring seat 42 is assembled onto shock absorber 26 and correctly positioned with respect to coil spring 28 . Bearing assembly 40 is positioned on top of upper spring seat 42 and top mount 38 is positioned on top of bearing assembly 40 . This entire assembly is positioned within an assembly machine which compresses coil spring 28 such that the end of piston rod 66 extends through a bore located within top mount assembly 36 . A retaining nut 68 is threadingly received on the end of piston rod 66 to secure the assembly of McPherson strut assembly 34 .
[0018] Top mount 38 is designed as an identical component for the right and left hand sides of the vehicle but it has a different orientation with respect to shock absorber 26 and its associated bracketry when it is placed on the right or left side of the vehicle.
[0019] Referring now to FIGS. 3 and 4 , an orientation device in the form of tooling 80 which automatically orientates top mount 38 is illustrated. Tooling 80 comprises a top mount fixture 82 and an upper tool 84 which compresses a base plate 86 , a bearing 88 and a guide 90 . Guide 90 is rotatably disposed within an opening defined by base plate 86 with bearing 88 being disposed between guide 90 and base plate 86 .
[0020] Top mount 38 is engaged by top mount fixture 82 . Top mount 38 with top mount fixture 82 is positioned within upper tool 84 with top mount fixture 82 engaging guide 90 . Bearing 88 is disposed between guide 90 and base plate 86 to permit rotation of top mount 38 , top mount fixture 82 and guide 90 with respect to base plate 86 in order to properly orientate top mount 38 with respect to shock absorber 26 . Base plate 86 includes a blocking stop 92 , a first position stop 94 and a second position stop 96 . A positioning stop 98 which is a part of top mount fixture 82 engages stops 92 , 94 and 96 to properly orientate top mount 38 with respect to shock absorber 26 .
[0021] During assembly of McPherson strut assembly 34 and the torquing of retaining nut 68 , positioning stop 98 engages blocking stop 92 to prohibit rotation of top mount 38 until the proper torque for retaining nut 68 is achieved. Once the assembly is completed and retaining nut 68 is tightened, top mount 38 is orientated in a counter-clockwise direction as illustrated in FIG. 4 . Top mount 38 and top mount fixture 82 are rotated counter-clockwise until positioning stop 98 engages first position stop 94 . Second position stop 96 is a spring mounted position stop which moves out of the way of positioning stop 98 when it moves counter-clockwise but second position stop 96 will act as a stop for positioning stop 98 when it is rotated clockwise as shown in FIG. 4 . If positioning stop 98 engaging first position stop 94 is the correct orientation for top mount 38 for its position in the vehicle such as the right side of the vehicle, control on the amount of torque for retaining nut 68 and a positional control are completed and the assembly process is complete. If the rotation of top mount 38 and top mount fixture 82 to its position where positioning stop 98 engages first position stop 94 , is not the correct position, such as the left side of the vehicle, top mount 38 and top mount fixture 82 are rotated clockwise until second position stop 96 is engaged which is the correct position for the opposite orientation of top mount 38 . The control for the torque on retaining nut 68 and a positional control are completed and the assembly process is complete.
[0022] While tooling 80 is illustrated as having blocking stop 92 and first and second position stops 94 and 96 , it is within the scope of the present invention to have additional spring supported mechanical stops which can be combined with the angular rotation command of the nut runner to provide additional final position stops if desired.
[0023] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
[0024] If the design of the top mount allows to use one or more parts of the top mount to fulfill the function of positioning stop 88 in one or more steps of the process, this considerably simplifies the set-up. This application is considered as within the scope of this invention.
|
The top mount of a strut assembly is capable of being orientated in various positions to accommodate various locations in a vehicle. An orientation device includes a top mount fixture which engages the top mount of the strut assembly. The top mount fixture is positioned within upper tooling and the top mount and top mount fixture are rotated in a first direction until a blocking stop on the upper tooling is engaged. The top mount and the top mount fixture are rotated in the opposite direction until a position stop on the upper tooling is engaged to properly orientate the top mount. Additional position stops can be added to the upper tooling to define additional orientations for the top mount.
| 1
|
BACKGROUND OF THE INVENTION
The present invention relates to an automatic needle thread supply control system for a sewing machine having a thread take-up member which takes up the needle thread in synchronism with the vertical reciprocatory motion of the needle and, more specifically, to an automatic needle thread supply control system having a pair of thread clamping members disposed between the thread supply source and the thread take-up member in the thread supply path extending from the thread supply source to the needle, for clamping and releasing the needle thread.
There have been proposed, to form satisfactory stitches, various sewing machines in which the thread supply is controlled so that points of interlock of the needle thread and the bobbin thread are located at the middle of the thickness of the fabric being sewn. Such a sewing machine disclosed, for example, in Japanese Patent Publication No. 58-10115 comprises a needle thread supply controller capable of temporarily releasing the needle thread to remove tension from the needle thread, and a detecting device for detecting the motion of the tension detector and actuating the needle thread supply controller, in which the needle thread supply controller releases the needle thread upon the arrival of the point of interlock of the needle thread and the bobbin thread at the middle of the thickness of the fabric being sewn. Another sewing machine disclosed in Japanese Patent Publication No. 60-19278 comprises an electromagnetic needle thread gripper disposed between the take-up lever and the needle, in which the needle thread gripper grips the needle thread to simultaneously stop pulling up the bobbin thread and to draw out the needle thread upon the arrival of the point of interlock of the needle thread and the bobbin thread at the middle of the thickness of the fabric being sewn.
In the known prior sewing machines described herein-before, however, the arrival of the point of interlock of the needle thread and the bobbin thread at the middle of the thickness of the fabric being sewn is not detected directly. Therefore, it is necessary, to locate the point of interlock of the needle thread and the bobbin thread accurately at the middle of the thickness of the fabric being sewn, that various factors which affect the needle thread tension, such as the type of fabric, the thickness of fabric, the type and thickness of thread, the width and length of stitch, and the type of pattern, are determined beforehand, the supply of the needle thread is calculated on the basis of those given factors, and the supply of the needle thread is controlled according to the result of the calculation. Accordingly, the sewing machine needs detectors for detecting those factors which affect the needle thread tension, and an arithmetic unit for calculating the supply of the needle thread on the basis of the results of the detection, and hence the sewing machine inevitably becomes complex and expensive.
A needle thread supply control system to obviate such inconveniences is disclosed, for example, in Japanese Patent Publication No. 53-41580. In this needle thread supply control system, a pair of tension discs are controlled by an actuator of the solenoid type for clamping and releasing the needle thread. The actuator is driven in synchronism with the main shaft of the sewing machine so as to permit the supply of the needle thread in a predetermined period in one stitching cycle and check the supply of the needle thread in the rest of the period. While the tension discs are released, the needle thread is supplied without restraint so that the supply of the needle thread is dependent only on the normal stitching conditions, such as the type of the fabric, stitch length and the type of pattern. After the needle thread has been supplied according to such normal stitching conditions, the tension discs are pressed together to check the supply of the needle thread in order to prevent the disarrangement of the stitch formed while the needle thread is supplied according to the normal stitching conditions. Thus, the needle thread supply control system eliminates the tension detector for detecting the tension of the needle thread and the device for calculating the supply of the needle thread, and hence simplifies the general constitution of the sewing machine.
However, this needle thread supply control system still has disadvantages. While the tension discs are released to supply the needle thread without restraint, the take-up lever swings from the uppermost position downward in synchronism with the vertical reciprocative motion of the needle. Consequently, part of the needle thread stored by the loop taker when the take-up lever is at the uppermost position is used as part of the needle thread necessary for forming the stitch. Accordingly, when the take-up lever returns to the uppermost position after the needle thread and the bobbin thread have been interlocked, an excessively high tension proportional to the length of the needle thread and used for forming the stitch among the length of the same stored by the loop taker is exerted on the needle thread; consequently, the bobbin thread is pulled out on the surface of the fabric being sewn deteriorating the quality of the stitch.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an automatic needle thread supply control system capable of accurately controlling the supply of the needle thread so that the point of interlock of the needle thread and the bobbin thread is always located within the fabric being sewn irrespective of the variation of the thickness of the fabric being sewn.
It is another object of the present invention to provide an automatic needle thread supply control system capable of controlling the needle thread tension at an optimum level according to the thickness of the fabric being sewn.
It is a further object of the present invention to provide an automatic needle thread supply control system capable of releasing and clamping the needle thread silently and surely.
The foregoing objects are attained according to the principle of the present invention. The first embodiment of the invention is in combination with a sewing machine having a needle thread supply source, an endwise reciprocatory needle with an eye, a feed member operating in synchronism with the reciprocation of the needle for imparting a feed motion to a work fabric, a take-up member movable between a first position where the needle thread is slackened to a maximum thread slack amount and a second position where the needle thread is taken up to a maximum thread take-up amount, and a needle thread supply path extending from the needle thread supply source through the take-up member to the eye of the needle, by providing an automatic needle thread supply control system comprising: thread securing means operative in synchronism with the reciprocation of the needle for securing the maximum thread take-up amount of the needle thread during a specific period which starts at a time determined so as to at least partly overlap with the period of the feed motion and terminates at a time when the eye of the needle is lowered near to the surface of a bed; thread supply stopping means operative to permit and check the supply of the needle thread which is drawn out from the needle thread supply source as the fabric is fed by the feed member; and control means operative in synchronism with the reciprocation of the needle for controlling the timing and the period of operation of the thread supply stopping means according to the thickness of the fabric being sewn or the thickness of the needle thread being used so that the thread supply stopping means permits the supply of the needle thread during the specific period.
The second embodiment of the invention is in combination with a sewing machine having the same constitution as that of abovementioned first invention, by providing an automatic needle thread supply control system comprising: driving means for timing the start of holding the take-up member at the second position so that the period of holding the take-up member at the second position at least partly overlaps with the period of the feed motion, holding the take-up member at the second position until the eye of the needle is lowered near to the surface of a bed, and moving the take-up member in synchronism with the reciprocation of the needle after the eye of the needle has been lowered near to the surface of the bed; thread supply stopping means operative to permit and check the supply of the needle thread which is drawn out from the needle thread supply source as the fabric is fed by the feed member; and control means operative in synchronism with the reciprocation of the needle for controlling the timing and the period of operation of the thread supply stopping means according to the thickness of the fabric being sewn or the thickness of the needle thread being used so that the thread supply stopping means permits the supply of the needle thread while the take-up member is held at the second position.
According to the present invention, the control means determines the timing of actuation and the period of operation of the thread supply stopping means according to the thickness of the fabric or the thickness of the needle thread every vertical movement of the needle and, while being actuated, the thread supply stopping means permits the free supply of the needle thread from the thread supply source to the take-up member. During the free supply of the needle thread, the take-up member is held at the maximum thread take-up position (second position), and thereby the fixed length of the thread stored by the loop taker is secured without being used for forming a stitch. Consequently, an optimum length of the needle thread spontaneously determined according various stitching conditions, such as the type of fabric and stitch length, is supplied from the thread supply source. After the period of actuation of the thread supply stopping means has elapsed the take-up member starts its motion in phase with the vertical reciprocatory motion of the needle upon the arrival of the eye of the needle at a position near the surface of the bed. As the take-up member moves toward the maximum thread slackening position (first position), the needle thread is supplied to the loop taker, and then the needle thread and the bobbin threads are interlocked through the known motion of the loop taker. The point of interlock of the needle thread and the bobbin thread is completed at a moment when the take-up member arrives at the maximum thread take-up position after the needle thread and the bobbin thread has been interlocked.
Preferably, the thread supply stopping means comprises a pair of thread clamping members having clamping surfaces which engage in point contact to surely clamp the needle thread.
Preferably, the control means comprises proportional control means operatively connected to the main shaft of the sewing machine to control the speed of at least either a motion for engaging or a motion for disengaging the thread clamping members of the thread supply stopping means in proportion to the rotating speed of the main shaft of the sewing machine.
If need be, the proportional control means may comprise a rotary member operatively connected to the main shaft of the sewing machine, a detector for generating a pulse signal every predetermined angle of rotation of the rotary member, and actuating means for varying the relative position of the thread clamping members in response to the pulse signal at least either in engaging or in disengaging the thread clamping members.
The proportional control means engages and disengages the thread clamping members through a smooth and continuous motion at a speed proportional to the rotating speed of the main shaft of the sewing machine. Accordingly, the phase of clamping the needle thread and the phase of releasing the needle thread vary according to the thickness of the needle thread. That is, a thick needle thread, as compared with a thin needle thread, is clamped at an earlier phase and is released at a later phase, and hence a thick needle thread of a less length is supplied for forming a stitch, so that a higher tension is exerted on the loop to tighten the loop, where as a thin needle thread of a more length is supplied and a lower tension is exerted to the thin needle thread for tightening the loop. Thus, the tension of the needle thread is controlled stably according to the thickness of the needle thread and the rotating speed of the main shaft of the sewing machine.
The third embodiment of the inventon is in combination with a sewing machine having a needle thread supply source, an endwise reciprocatory needle with an eye, a take-up member movable between a maximum thread slack position and a maximum thread take-up position, and a needle thread supply path extending from the needle thread supply source through the take-up member to the eye of the needle, by providing an automatic needle thread supply control system comprising: a pair of thread clamping members movable toward and away from each other for checking and permitting the supply of the needle thread from the needle thread supply source toward the take-up member; and proportional control means for controlling the speed of at least either a motion for engaging or a motion for disengaging the thread clamping members in proportion to a sewing speed; whereby the timing and the period of checking and permitting the supply of the needle thread are automatically changed according to the thickness of the needle thread being used.
If need be, the proportional control means may comprise a cam member operatively connected to the main shaft of the sewing machine and a cam follower engageable with the cam member and operatively connected to one of the thread clamping members.
The fourth embodiment of the invention is in combination with a sewing machine having a needle thread supply source, an endwise reciprocatory needle with an eye, and a needle thread supply path extending from the needle thread supply source and to the eye of the needle and including at least one bent portion, by providing an automatic needle thread supply control system comprising: a pair of thread contacting members located at the bent portion of the needle thread supply path and movable toward and away from each other in a specific direction which is substantially parallel to a plane including the needle thread supply path about the bent portion; and control means for controlling the movement of the thread contacting members to vary an amount of the needle thread to be supplied toward the eye of the needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the essential portion of an automatic needle thread tension control system, in a preferred first embodiment, according to the present invention incorporated into a sewing machine;
FIG. 2 is a sectional view showing a mechanism mounted on one end of the main shaft of the sewing machine shown in FIG. 1;
FIG. 3 is a time chart showing the respective motions of the components of the sewing machine under the control of the automatic needle thread tension control system of FIG. 1;
FIGS. 4 and 5 are sectional views showing stitches formed on the sewing machine incorporating the embodiment;
FIG. 6 is a fragmentary perspective view of the head and the associated parts of the sewing machine incorporating the embodiment;
FIG. 7 is a schematic perspective view of a sewing machine incorporated a second embodiment of the present invention;
FIG. 8 is a perspective view of the essential portion of the internal mechanism built in the head of the sewing machine of FIG. 7;
FIG. 9 is a side elevation of the internal mechanism of FIG. 8;
FIG. 10 is a front elevation of the internal mechanism of FIG. 8;
FIG. 11 is a time chart showing the respective motions of the mechanisms of the sewing machine of FIG. 7;
FIG. 12 is a sectional view taken on line XII--XII in FIG. 10;
FIG. 13 is a sectional view taken on line XIII--XIII in FIG. 9;
FIGS. 14 to 17 are schematic illustrations showing modifications of the thread clamping members shown in FIG. 13;
FIG. 18 is block diagram showing the electrical constitution of a modification of the thread passage control unit of the second embodiment; and
FIG. 19 is a time chart showing the variation of the gap of the thread path in relation to a timing signal and a phase signal and the variation of the solenoid driving current in the modification shown in FIG. 18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings.
First Embodiment (FIGS. 1 to 6):
Constitution
Referring to FIG. 6, a sewing machine has a work supporting bed 2, a standard (not shown) standing on the work supporting bed 2, and an arm 6 supporting by the standard so as to over hang horizontally over the work supporting bed 2 and provided at the free end thereof with a head unit 4. A needle bar 12 is provided in the head unit 4 so as to be driven by a swing mechanism (not shown) for lateral jogging motion, and by an arm shaft 22 for vertical reciprocatory motion. A feed dog 9 is moved upward through slots formed in a throat plate 8 provided on the work supporting bed 2 by a feed mechanism (not shown) to feed a work fabric 37. Predetermined stitches are formed in the work fabric 37 through the cooperative motion of the needle bar 12 and the feed dog 9.
Referring now to FIG. 1, the needle bar 12 holding a needle 10 at the lower end thereof is supported vertically movably by a needle bar guide 18 pivotally supported on a pin 16 fixed to the frame 14 (not shown in FIG. 1) of the sewing machine. The needle bar 12 is driven for vertical motion through a crank arm 20 by the arm shaft 22. A presser bar 26 holds a presser foot 24 at the lower end thereof, and is moved between an upper position and a lower position by a mechanism (not shown). The presser bar 26 is mounted on the frame 14. When the presser bar 26 is located at the lower position, the presser foot 24 exerts a pre-determined pressure to the work fabric 37.
A needle thread holder 30 holding a needle thread spool 28, i.e., a needle thread supply source, and a base plate 33 supporting a guide plate 31 and a needle thread clamping device 36 are fixed to the upper surface of the head unit 4 of the frame 14. A needle thread 32 drawn out from the needle thread spool 28 is threaded sequentially through a pre-tension spring plate 34 fixed to the guide plate 31, the needle thread clamping device 36, a first guide 38, and a second guide 40 to a guide hole 43 formed in the free end of a take-up lever 42, and then further through a third guide 44 fixed to the frame 14, and a fourth guide 46 fixed to the needle bar 12 and finally to the eye 48 of the needle 10. The pre-tension spring plate 34 resiliently applies a predetermined sliding resistance to the needle thread 32. The needle thread clamping device 36 functions as the thread supply stopping means of the present invention. The needle thread clamping device 36 comprises a bar 49 fixed to the base plate 33, an upper disc 50 supported by the bar 49, a lower disc 54 disposed opposite to the upper disc 50, and a spring 52 biasing the lower disc 54 toward the upper disc 50. The needle thread 32 is clamped between the upper disc 50 and the lower disc 54 to stop the supply of the needle thread 32. In this embodiment, the upper disc 50 and the lower disc 54 functions as the needle thread clamping members, the spring 52 functions as the elastic member for engaging the needle thread clamping members, and a connecting member 70 functions as the releasing member for releasing the needle thread 32 from the needle thread clamping members.
The second guide 40 is provided with a pre-tension spring plate 56 and a spring arm 58 to apply a predetermined sliding resistance to the needle thread 32 and to prevent the needle thread 32 from being broken when the tension on the needle thread is increased temporarily. The maximum tension that is exerted on the needle thread 32 is limited, for example, to a tension between the breaking tension of a 30/1 cotton thread and a tension required for forming satisfactory stitches in sewing denim of 5 mm in thickness. Thus, spring arm 58 functions as a buffer.
As illustrated in FIG. 2, the arm shaft 22 is supported rotatably at one end in a bearing bush 60 on the frame 14, and a cam member 62 is fixedly mounted on the arm shaft 22 near the end of the same. A first annular groove 64 and a second annular groove 66 are formed in the circumference of the cam member 62. The bottom surface of the first annular groove functions as a first cam for controlling the needle thread clamping device 36. The second annular groove 66 is a groove cam hainv a side wall functioning as a second cam for controlling the motion of the take-up lever 42. The first and second cams are designed so as to control the needle thread clamping device 36 and the take-up lever 42, respectively, for motions indicated by motion curves in FIG. 3. A needle thread clamp control plate 68 is mounted on the arm shaft 22 for rotation relative to and coaxially with the arm shaft 22 between the cam member 62 and the bearing bush 60.
A control lever 72 is pivotally attached to the needle thread clamp control plate 68 with a pin 73. The control lever 72 has one end placed in sliding contact with the bottom surface of the first annular groove 64, and the other end connected by the connecting member 70 to the upper disc 50. The control plate 68 is connected to the presser bar 26 by a first link 74 and a second link 76, and hence the control plate 68 does not rotate together with the arm shaft 22. Since the control lever 72 is caused to swing by the first cam of the first annular groove 64 as the arm shaft 22 rotates; consequently, the needle thread clamping device 36 is driven in phase with the arm shaft 22 for needle thread clamping and releasing motion as represented by the motion curve in FIG. 3. The first link 74 is joined pivotally at the central portion thereof to the frame 14 with a pin (not shown). When the presser foot 24 is lowered to press the work fabric 37, the control plate 68 is turned by an angle corresponding to the thickness of the work fabric 37 so that the phases of the needle thread clamping motion and needle thread releasing motion of the needle thread clamping device 36 are advanced with the increase of the thickness of the work fabric 37. Thus, in this embodiment, a mechanism comprising the needle thread clamp control plate 68 and the first cam of the first annular groove 64 corresponds to the control means for controlling the phases of the needle thread clamping motion and needle thread releasing motion of the needle thread clamping device 36 in relation to the thickness of the work fabric 37.
The take-up lever 42, i.e., the take-up member is joined pivotally at the base end to the frame 14 with a pin 78. A cam follower 80 is fixed to the base end of the take-up lever 42. The cam follower 80 engages the second cam of the second annular groove 66, so that the take-up lever 42 is driven in phase with the arm shaft 22 by the second cam of the second annular groove 66 for vertical motion as represented by the motion curve in FIG. 3. Thus, in this embodiment, the second annular groove 66 corresponds to the take-up member driving means for vertically driving the take-up member. A coil spring 82 is extended between the base end of the take-up lever 42 and the frame 14 so as to bias the take-up lever 42 upward so that the take-up lever 42 is moved smoothly upward.
FIG. 3 is a time chart showing the motions of the components of the thus constituted lock stitch sewing machine. In FIG. 3, the phase of the arm shaft 22 is measured by angle of rotation on the horizontal axis.
Function and Effect
Referring to FIG. 3, the needle thread clamping device 36 is controlled in synchronism with the vertical motion of the needle 12 and the feed motion of the feed dog 9 by the first cam formed on the bottom surface of the first annular groove 64. The needle thread 32 is released from the needle thread clamping device 36 during a period between the start of the feed motion of the feed dog 9 and a moment when the eye 48 of the needle 10 arrives at a position near the surface of the bed, namely, a moment when the eye 48 arrives substantially at the middle of the thickness of the work fabric 37. Upon the arrival of the eye 48 of the needle 10 at a position near the surface of the bed, the needle thread clamping device 36 clamps the needle thread 32 to stop the supply of the needle thread 32. On the other hand, while the needle thread 32 is being supplied without restraint, the take-up lever 42 is held at the uppermost position. Thus the needle thread clamping device 36 permits the free supply of the needle thread 32 by an amount corresponding to the downward movement of the eye 48 of the needle 10 to a position near the surface of the bed and the feed of the work fabric 37, while the take-up lever 42 is held at the uppermost position. Accordingly, the needle thread 32 is supplied against a small sliding resistance necessary only to prevent slack in the needle thread 32. After the needle thread 32 has been supplied by the necessary amount without restraint, the needle thread clamping device 36 clamps the needle thread 32 to prevent the excessive supply of the needle thread 32.
After the needle thread 32 has thus been clamped by the needle thread clamping device 36, the take-up lever 42 starts moving downward according to the predetermined motion curve to slacken the needle thread 32 clamped by the needle thread clamping device 36 so that needle thread 32 will not be strained excessively by the downward movement of the needle 10 and the needle thread 32 is able to be interlocked with the bobbin thread 35. Incidentally, in FIG. 3, the movement of the take-up lever 42 from an angle where the needle thread 32 is clamped to an angle corresponding to a point A where the shuttle hook catches a loop of the needle thread corresponds to the half of needle thread demand necessary for the downward movement of the needle bar 12, while the movement of the take-up lever 42 from the point A to an angle where the needle thread 32 is released from the needle thread clamping device 36 corresponds to the half of bobbin thread demand necessary for the motion of the shuttle (not shown).
A stitch as illustrated in FIG. 4 is formed through the motions of the needle bar 12, the feed dog 9, the needle thread clamping device 36 and the take-up lever 42 synchronous with the rotation of the arm shaft 22. While the take-up lever 42 is held at the uppermost position, only an actually necessary amount of the needle thread 32 for forming a stitch is supplied without being restrained by the needle thread clamping device 36, and the excessive supply of the needle thread 32 is prevented by the needle thread clamping device 36 after the actually necessary amount of the needle thread has been supplied. Thus, an optimum stitch having the point of interlock of the needle thread 32 and the bobbin thread 35 at the middle of the thickness of the work fabric 37 is formed.
Since the height of the presser bar 26 at a position where the presser foot 24 is pressing the work fabric 37 is dependent on the thickness of the work fabric 37, the phase of operation of the needle thread clamping device 36 is advanced with the increase of the thickness of the work fabric 37 as indicated by broken line in FIG. 3. Accordingly, as illustrated in FIG. 5, the point of interlock of the needle thread 32 and the bobbin thread 35 is located at the middle of the thickness of the work fabric 37 regardless of the thickness of the work fabric 37. The broken line in FIG. 3 indicates the operation of the needle thread clamping device 36, for example, when the thickness of the work fabric 37 is on the order of 5 mm, in which the needle thread clamping device 36 clamps the needle thread 32 upon the arrival of the eye 48 of the needle 10 at a position at a height of about 2.5 mm (a height B in FIG. 3) from the surface of the bed. The motion curve of the needle thread clamping device 36 indicated by continuous line in FIG. 3 represents the action of the needle thread clamping device 36 when the thickness of the work fabric 37 is almost zero, in which the needle thread clamping device 36 clamps the needle thread 32 upon the arrival of the eye 48 of the needle 10 on a level flush with the surface of the bed.
Thus, the needle thread clamping device 36 permits the free supply of the needle thread 32 and the take-up lever 42 is held at the uppermost position while the needle thread 32 is being supplied by an amount actually necessary for forming a stitch, and then the needle thread clamping device 36 stops the supply of the needle thread 32 after the needle thread 32 has been supplied by the actually necessary amount to prevent the excessive supply of the needle thread 32. Furthermore, the phase of the needle thread clamping operation of the needle thread clamping device 36 is regulated according to the thickness of the work fabric 37. Consequently, an optimum stitch having the point of interlock of the needle thread 32 and the bobbin thread 35 at the middle of the thickness of the work fabric 37 is formed regardless of various conditions affecting the tension of the needle thread, such as the type of the work fabric 37, the type and thickness of the needle thread 32 or the bobbin thread 35, the width and length of stitch, and the type of pattern.
Still further, there is provided with the spring arm 58 of the second guide 40 which yields to an excessively high tension, and thereby the needle thread 32 is prevented from being broken by an excessive tension temporarily exerted on the needle thread 32. That is, although the moment when a necessary amount of the needle thread 32 is drawn out by the motion of the needle bar 12 coincides substantially with a moment when the eye 48 of the needle 10 arrives at the surface of the bed, since the needle thread clamping device 36 clamps the needle thread 32 upon the arrival of the eye 48 of the needle 10 at the middle of the thickness of the work fabric 37 when the work fabric 37 has a large thickness, more needle thread 32 needs to be supplied as the needle bar 12 moves further downward. However, since the take-up lever 42 is held at the uppermost position until the eye 48 of the needle 10 arrives at the surface of the bed, the tension of the needle thread 32 increases inevitably for a moment after the needle thread 32 has been clamped by the needle thread clamping device 36. Normally, the increment of the tension is absorbed by the extension of the needle thread 32, however, when the needle thread 32 is not very extendable it is possible that the needle thread 32 is broken. In such a case, the spring arm 58 functions properly to supplement the needle thread 32 so that the rise in the tension is mitigated. Although the first embodiment has been described hereinbefore with reference to the related drawings, the following modifications are possible in the first embodiment.
In the first embodiment, the take-up lever 42 starts moving downward upon the arrival of the eye 48 of the needle 10 at the surface of the bed. However, it is possible, for example, to shift the phase of start of the downward motion of the take-up lever according to the thickness of the work fabric 37 similarly to the shift of the phase of the needle thread clamping motion of the needle thread clamping device 36.
Furthermore, although the phase of the needle thread releasing motion of the needle thread clamping device 36 coincides with the phase of start of the feed motion of the feed dog 9 for feeding the work fabric 37 in the first embodiment, the phase of the needle thread releasing motion of the needle thread clamping device 36 may be delayed by a fixed angle of rotation of the arm shaft 22 with respect to the phase of start of the feed motion of the feed dog 9. Delaying the phase of the needle thread releasing motion affects favorably to tightening a stitch. The shift of the phase of the needle thread releasing motion of the needle thread clamping device 36 relative to those of the coincidental motions reduces noises.
Furthermore, in the first embodiment, the phases of the needle thread clamping operation and needle thread releasing operation of the needle thread clamping device 36 is regulated according to the thickness of the work fabric 37 by connecting the control plate 68 through the first link 74 and the second link 76 to the presser bar 26. However, it is also possible to regulate the phases of the needle thread clamping operation and needle thread releasing operation of the needle thread clamping device 36 by varying the operating position of the control plate 68 by a driving device on the basis of the output signal of an electric thickness detector for electrically detecting the thickness of the work fabric 37, according to the predetermined relation between the thickness of the work fabric and the optimum phase of operation of the needle thread clamping device.
Still further, an electrically or mechanically driven auxiliary take-up lever for temporarily supplementing the needle thread 32 at the start of the needle thread clamping operation of the needle thread clamping device 36 may be employed instead of the spring arm 58.
Second Embodiment (FIGS. 7 to 19):
Constitution, Function and Effect
In a second embodiment, the supply of the needle thread is controlled according to the thickness of the needle thread instead of the thickness of the work fabric as in the first embodiment.
FIG. 7 illustrates an electronic lock stitch sewing machine M incorporating a second embodiment of the present invention. Illustrated in FIG. 7 are a bed 102, a standard 104 extending upright from the right end of the bed 102, and an arm 106 horizontally extending from the upper end of the standard 104, overhanging the bed 102 and having a head 108 at the left end thereof. A needle bar 110 and a presser bar 118 are provided in the head 108. A needle 112 is attached to the lower end of the needle bar 110. The needle bar 110 is driven for vertical reciprocatory motion and for lateral jogging motion by the arm shaft 128 of the sewing machine. A presser foot 120 is attached to the lower end of the presser bar 118. The presser bar 118 is raised or lowered by means of an operating member (not shown).
A throat plate 122 is provided on the bed 102, and a feed dog 123 is provided in the bed 102 so as to be moved upward through slots formed in the throat plate 122 by a feed mechanism. Predetermined stitches are formed in a work fabric through the cooperative operation of the needle bar 110 and the feed mechanism including the feed dog 123. Since the feed mechanism is of an ordinary known constitution, the description thereof will be omitted.
FIGS. 8 to 10 illustrate internal mechanisms disposed within the head 108 and part of the arm 106 near the head 108 of the sewing machine M.
As illustrated in FIGS. 8 to 10, the needle 112 is attached to the lower end of the needle bar 110, while the needle bar 110 is supported vertically movably by a needle bar support 124. The needle bar support 124 is supported pivotally at the upper end thereof with a pin 126 on the frame so as to jog laterally. The needle bar 110 is driven by the arm shaft 128 and a needle bar crank 130 secured to the free end of the arm shaft 128 for vertical motion relative to the needle bar support 124.
The presser foot 120 is attached detachably to the lower end of the presser bar 118, while the presser bar 118 is secured to the frame by a mechanism (not shown) so as to be moved between an upper position and a lower position. When the presser bar 118 is moved to the lower position, the presser foot 120 presses a work fabric against the throat plate 122.
A take-up lever mechanism will be described hereinafter with reference to FIGS. 8 to 10.
The arm shaft 128 is supported rotatably in a bearing bush 132 or the like on the frame. An auxiliary shaft 134 is disposed above and behind the arm shaft 128 so as to extend in parallel to the same. The auxiliary shaft 134 is journaled on the frame. A swing lever 136 is supported swingably at one end thereof on the auxiliary shaft 134. The swing lever 136 extends from the auxiliary shaft 134 to the left side of a take-up lever crank 138 fixedly mounted on the arm shaft 128. The crank pin 140 of the take-up lever crank 138 extends through a slot cam 142 formed in the swing lever 136. A connecting plate 144 is fixed to the left end of the crank pin 140. The needle bar crank 130 is connected rotatably to the connecting plate 144 with a pin 146 extending leftward from the connecting plate 144. The needle bar crank 130 is connected at the lower end thereof to the middle part of the needle bar 110.
The upper part of the swing lever 136 is bent in a zigzag shape to form a take-up lever 148 (take-up member) which extends upward. A thread guide hole 148a is formed at the free end of the take-up lever 148.
As illustrated in FIGS. 8 and 9, the slot cam 142 of the swing lever 136 consists of a circular arc section 142a having a radius of curvature coinciding with the radius of the circular locus of the crank pin 140 and permitting the rotation of the crank pin 140 through an angle of approximately 74° in a range about the uppermost position of the crank pin 140, and short straight sections 142b extending from the opposite ends of the circular arc section 142a, respectively. The slot cam 142 is reinforced along the periphery thereof with a reinforcement 136a.
When the take-up lever crank 138 and the crankpin 140 are turned around the arm shaft 128 with the crankpin 140 engaging the slot cam 142 of the swing lever 136, the swing lever 136 is driven for reciprocatory swing motion about the auxiliary shaft 134 between an uppermost position indicated by continuous lines (FIG. 9) and a lowermost position indicated by imaginary lines (FIG. 9) by the crankpin 140, while the needle bar 110 is driven for vertical reciprocatory motion through the needle bar crank 130 and the crankpin 140 by the arm shaft 128 in phase with the arm shaft 128.
Since the slot cam 142 of the swing lever 136 has the circular arc section 142a, the take-up lever 148, the needle 112 attached to the lower end of the needle bar 110 and the feed dog 123 of the feed mechanism perform motions represented by motion curves MA, MB and MD as functions as the phase angle of the arm shaft 128 as a parameter in FIG. 11, respectively.
The take-up lever 148 is held at the uppermost position from a time after the arm shaft 128 has turned through an angle of approximately 40° from the start of the feed motion to a time when the eye of the needle 112 arrives at the upper surface of the throat plate 122. Accordingly, the take-up lever 148 is held at the upper most position substantially during the feed motion except the initial stage of the feed motion. The swing lever 136 may be designed so that the take-up lever 148 is held at the upper most position from the start of the feed motion. In either case, the swing lever 136 of the second embodiment is comparatively simple in construction and is able to operate smoothly and silently.
A thread supply control mechanism will be described hereinafter with reference to FIGS. 8 to 13.
A plate member 150 forming part of the frame is disposed near and on the lefthand side of the needle bar crank 130 disposed on the lefthand side of the arm shaft 120. The plate member 150 extends at right angles to the arm shaft 128. As illustrated in FIGS. 8 and 9, a pre-tension device 152 for exerting a tension to the needle thread 114 is provided, when necessary, on the left side of the plate member 150 slightly before the arm shaft 128.
The pre-tension device 152 has a pair of tension discs 152a which exert a tension to the needle thread passing therebetween. The tension of the needle thread is adjusted by regulating spring force applied to the tension discs 152a by operating a dial. The pre-tension device 152 may be omitted.
A thread supply control device 154 which clamps or releases the needle thread 114 in synchronism with the rotation of the arm shaft 128 is provided in a thread path between a thread supply spool 116 and the thread guide hole 148a of the take-up lever 148. The thread supply control device 154 comprises a thread guide plate 156, and a swing lever 158 provided with a thread clamping wheel 164. The thread guide plate 156 (thread clamping member) is secured to the left side of the plate member 150 at a position below the pre-tension device 152. The swing lever 158 is disposed adjacent to the left side of the thread guide plate 156 and is pivotally attached to the plate member 150 with a hinge screw 162. A link plate 160 also is pivotally attached at the lower end thereof to the plate member 150 with the hinge screw 162. The thread clamping wheel 164 (thread clamping member) held on the swing lever 158 engages the thread clamping edge 156a of the thread guide plate 156 to clamp the needle thread 114 between the thread clamping edge 156a and the thread clamping wheel 164. The swing lever 158 is biased resiliently by a spring 166 having one end connected to the frame and the other end connected to the swing lever 158 so that the thread clamping wheel 164 is pressed against the thread clamping edge 156a. A contact wheel 168 attached to the upper end of the arm 158a of the swing lever 158 is in contact with the front surface of a contact lug 160a formed near the lower end of the link plate 160.
As illustrated in FIGS. 8, 9 and 13, an annular V-shaped groove 164a is formed in the circumference of the thread clamping wheel 164, while the thread clamping edge 156a of the thread guide plate 156 is formed in a U-shaped curve opening downward in a side view and in a U-shape in section. The V-shaped groove 164a of the thread clamping wheel 164 and the U-shaped thread clamping edge 156a of the thread guide plate engage to clamp the needle thread 114 therebetween.
After passing the pre-tension device 152, the needle thread 114 is turned by the U-shaped thread clamping edge 156a of the thread guide plate 156, and is guided via the thread guide hole 148a of the take-up lever 148 to the needle 112. When the thread clamping edge 156a and the V-shaped groove 164a are engaged, the needle thread 114 is clamped firmly between the thread clamping edge 156a and the V-shape groove 164a at two points. Particularly, since the thread clamping wheel 164 is moved in parallel to a plane including the thread supply path returned at the thread clamping edge 156a and the thread clamping wheel 164 clamps the needle thread 114 across the same, a very high clamping pressure is applied the the needle thread 114. That is, if the thread clamping wheel 164 is pressed with a small force against the thread clamping edge 156a, the needle thread 114 can firmly be clamped.
To drive the thread clamping wheel 164 in phase with the rotation of the arm shaft 128 at a speed proportional to the rotating speed of the arm shaft 128 toward and away from the thread clamping edge 156a to clamp and release the needle thread 114 alternately at predetermined phase angles of the arm shaft 128, a rotary cam 170 (proportional control means) having an elliptic cam groove 172 is fixedly mounted on the arm shaft 128 at a position opposite the right end of the auxiliary shaft 134, and a cam follower 174a attached to the free end of a first arm 174 engages the cam groove 172.
On the other hand, a second arm 176 is fixedly mounted to the auxiliary shaft 134 at the left end of the same. A pin 176a attached to the free end of the second arm 176 is received in a slot 160b formed in the upper end of the link plate 160 to interconnect the second arm 176 and the link plate 160.
In the abovementioned thread supply control device 154, when the arm shaft 128 is rotated to swing the first arm 174 by the elliptic cam groove 172 of the rotary cam 170, the link plate 160 is reciprocated through the auxiliary shaft 134 and the second arm 176 on the hinge screw 162.
When the contact wheel 168 is pushed forward by the contact lug 160a of the link plate 160 as the link plate 160 is driven by the second arm 176, the swing lever 158 is turned against the resilient force of the spring 166, so that the thread clamping wheel 164 is separated from the thread clamping edge 156a of the thread guide plate 156 to release the needle thread 114. When the contact lug 160a of the link plate 160 is moved backward, the swing lever 158 is turned in the opposite direction by the spring 166, so that the thread clamping wheel 164 engages the thread clamping edge 156a to clamp the needle thread 114. Thus, the needle thread 114 is clamped and released alternately at predetermined phase angles, respectively. The needle thread clamping and releasing motion is represented by a motion curve MC in FIG. 11.
As in apparent from FIG. 11, during the upward movement of the take-up lever 148 from the lowermost position to the uppermost position for tightening the needle thread 114, the needle thread 114 is clamped between the thread guide plate 156 and the thread clamping wheel 164 so that the needle thread 114 is surely tightened. After the needle thread 114 has completely been tightened, the swing lever 158 is driven in phase with the feed motion to release and supply the needle thread 114. While the needle thread 114 is thus released free, the feed motion and the needle jogging motion are accomplished, and then the needle thread 114 is clamped again before the needle 112 arrives at the throat plate 122. While the needle thread 114 is clamped, the stitching motion is carried out to form a needle thread loop by the shuttle. Accordingly, the needle thread of an amount necessary for feeding the work fabric and for jogging the needle 112 is surely supplied, while the needle thread 114 is not supplied uselessly while a loop of the needle thread 114 is formed, because the needle thread 114 is clamped during the loop forming period.
As is apparent from the motion curve MC shown in FIG. 11, owing to the needle thread clamping characteristics determined by the shape of the elliptic cam groove 172 of the rotary cam 170, when the thickness of the needle thread 114 is small, the needle thread 114 is released and is clamped at a point F 1 and at a point C 1 , respectively. When the thickness of the needle thread 114 is large, the needle thread 114 is released at a point F 2 after the point F 1 , and is clamped at the point C 2 before the point C 1 . Accordingly, thin needle threads and thick needle threads are tightened properly at a low tension and at a high tension, respectively.
Since the cam groove 172 of the rotary cam 170 serving as the proportional control means has an elliptic can surface, the respective speed of the upward swing and downward swing of the first arm 174 are proportional to the rotating speed of the arm shaft 128, so that the needle thread clamping wheel 164 is moved toward and away from the thread clamping edge 156a at a speed proportional to the rotating speed of the arm shaft 128. Thus, a substantially fixed amount of the needle thread 114 is supplied in every stitching cycle regardless of the rotating speed of the arm shaft 128, and hence the tension of the needle thread in forming stitches is not affected by the stitching speed.
A needle thread supply mechanism 178 which draws out the needle thread 114 from the thread supply spool 116 by a predetermined amount and stores the same while the take-up lever 148 is moved downward and the needle thread 114 is clamped between the needle thread clamping wheel 164 and the needle thread guide plate 156 will be described hereinafter with reference to FIGS. 8 to 10.
A sleeve 180 is fitted rotatably on the auxiliary shaft 134 near a position where the auxiliary shaft 134 supports the swing lever 136 at one end, and the end of the swing lever 136 on the auxiliary shaft 134 is fixed to the sleeve 180. An L-shaped arm 182 having a thread catching hook 182a at the free end thereof is fixed to the sleeve 180. A thread guide member 184 substantially of a U-shape in front view is disposed on top of the left end of the arm 106 of the sewing machine M. The thread guide member 184 has a top wall 184a, a first guide wall 184b and a second guide wall 184c. The first guide wall 184b and the second guide wall 184c extend vertically downward from the opposite sides of the top guide wall 184a, respectively. The second guide wall 184c of the thread guide member 184 is fixed to the upper end of the plate member 150 with a screw 186. The thread guide member 184 is disposed near and above the L-shaped arm 182. The first guide wall 184b and the second guide wall 184c are disposed opposite to each other with a predetermined distance therebetween. A first guide slit 188a and a second guide slit 188b are formed laterally opposite to each other in the first guide wall 184b and the second guide wall 184c, respectively. The respective rear ends of the first guide slit 188a and the second guide slit 188b are open to receive the needle thread 114 therein. A third guide slit 190 is formed in the upper part of the front end of the second guide wall 184c.
The needle thread 114 pulled out from the thread supply spool 116 is extended sequentially through the first guide slit 188a, the second guide slit 188b, along the left side of the second guide wall 184c, via the third guide slit 190, the pre-tension device 152, the thread clamping edge 156a of the thread guide plate 156, where the needle thread 114 is returned upward, and then further through the thread guide hole 148a of the take-up lever 148, and thread guides 192 and 194 to the eye of the needle 112.
Both the L-shaped arm 182 and the swing lever 136 are fixed to the sleeve 180, and hence the L-shaped arm 182 and the swing lever 136 are driven for swing motion by the take-up lever crank 138 in phase with the rotation of the arm shaft 128. As illustrated in FIG. 9, while the take-up lever 148 is held at the uppermost position as indicated by continuous lines, the L-shaped arm 182 is located, as indicated by dotted lines, behind the needle thread 114 passing the respectively front ends of the first guide slit 188a and the second guide slit 188b. On the other hand, when the take-up lever 148 is moved downward the lowermost position as indicated by imaginary lines, the swing lever 136 swings on the auxiliary shaft 134 and the L-shaped arm 182 swings forward as indicated by imaginary lines on the auxiliary shaft 134, so that the thread catching hook 182a is moved forward and engages the needle thread 114 extending between the respective front ends of the first guide slit 188a and the second guide slit 188b, and thereby the needle thread 114 is pulled by the thread catching hook 182a by a predetermined distance. Since the needle thread 114 is clamped between the thread clamping wheel 164 and the thread guide plate 156 while the needle thread 114 is pulled by the thread catching hook 182a, a predetermined amount of the needle thread is surely pulled out from the thread supply spool 116.
Thus, while the take-up lever 148 is located at the lowermost position, the needle thread 114 is pulled out from the thread supply spool 116 by the L-shaped arm 182 of the needle thread supply mechanism 178, so that the needle thread 114 between the thread supply spool 116 and the thread clamping edge of the thread guide plate 156 is slackened. After the needle thread 114 has thus been slackened, the take-up lever 148 is moved upward to tighten the needle thread 114, then the needle thread 114 is released from the restrain of the thread guide plate 156 and the thread clamping wheel 164, and then the needle thread 114 of a necessary amount is supplied via the take-up lever 148 to the needle 112 as the feed dog 123 performs the feed motion and the needle 112 is jogged.
Although the feed motion of the feed dog 123 is started before the needle thread 114 is released, the amount of the needle thread 114 required for such a mode of feed motion is supplemented by the elastic extension of the needle thread 114, and the needle thread 114 is recovered from the elastic extension as the same is supplied after being released.
Thus, the phases of the needle thread clamping and releasing operations are controlled automatically according to the thickness of the needle thread 114, and the needle thread 114 of a necessary amount dependent on the feed stroke and the needle jogging stroke is surely supplied for every stitching cycle. Accordingly, an optimum tension according to the thickness of the needle thread 114 is exerted to the needle thread 114.
In the thread supply control device 154, a U-shaped groove 164b may be formed in the circumference of the thread clamping wheel 164, as illustrated in FIG. 14, the thread clamping wheel 164 may be moved obliquely relative to the thread guide plate 156 as illustrated in FIG. 15, or the needle clamping wheel 164 may have a cylindrical circumference as illustrated in FIG. 16. Furthermore, although not shown, a member secured to the swing lever 158 may be employed instead of the thread clamping wheel 164. Still further, it is also possible to employ a grooved free wheel 156A instead of the thread clamping edge 156a. When the free wheel 156A is employed, the needle thread 114 is wound around the half of the circumference of the free wheel 156A, and a clamping member 164A substituting the thread clamping wheel 164 is brought into point-contact with the circumference of the free wheel 156A to clamp the needle thread as illustrated in FIG. 17.
A modification of the thread supply control device will be described hereinafter with reference to FIG. 18 and FIG. 19.
The thread supply control device 154A comprises the thread clamping wheel 164, a linear actuator 200 for driving the thread clamping wheel 164, a displacement sensor 201 for sensing the displacement of the thread clamping wheel 164, a phase angle sensor 202 for sensing the phase angle of the arm shaft 128, a timing sensor 203, and a control unit 204.
The linear actuator 200 comprises a moving coil 205 connected to the thread clamping wheel 164, a metallic frame 206 vertically movably retaining the moving coil 205 and forming a magnetic path, and a permanent magnet 207 forming a uniform magnetic field around the moving coil 205. The vertical position of the moving coil is determined according to the intensity of current supplied to the moving coil 205.
The displacement sensor 201 is a potentiometer comprising a contact 209 connected to the thread clamping wheel supporting member 208 of the moving coil 205, and and electric resistor 210 connected to a reference voltage line.
The phase angle sensor 202 comprises, for example, a disc have a plurality of slits formed along the circumference thereof at regular angular intervals and fixed to the arm shaft 128, and a photoelectric detector comprising a light emitting element and a light receiving element for detecting the slits.
The timing sensor 203 is a limit switch or a contactless switch which detects the arrival of the needle bar 110 at the upper most position.
The control unit 204 comprises a central processing unit (hereinafter abbreviated to "CPU") 211, a read-only memory (ROM) 212, a random access memory (RAM) 213, an input-output interface 214, a driving circuit 215 which receives control signals through the input-output interface 214 from the CPU 211 and supplies a driving current corresponding to the input signal to the moving coil 205, and an AD converter 216 which converts an analog detection signal of the displacement sensor 201 into a digital signal corresponding to the analog detection signal and gives the same to the input-output interface 214. The detection signals of the phase angle sensor 202 and the timing sensor 203 are given through the input-output interface 214 to the CPU 211. The input-output interface 214, the ROM 212 and the RAM 213 are connected through an address bus and a data bus to the CPU 211.
The ROM 212 pre-stores a control program for controlling the linear actuator 200 in accordance with a timing signal S 1 given by the timing sensor 203, a phase angle signal S 2 given by the phase angle sensor 202 and a displacement signal given by the displacement sensor 201 to regulate the gap between the thread clamping wheel 164 and the thread clamping edge 156a of the thread guide plate 156.
Since the mode of controlling the linear actuator 200 is comparatively simple, the same will be described characteristically hereinafter.
Referring to FIG. 19, a predetermined current is supplied to the moving coil 205 until a predetermined number of phase angle signals S 2 are given to the CPU 211 after a timing signal S 1 has been given to the CPU 211, and thereby the thread clamping wheel 164 is held in contact with the thread clamping edge 156a to clamp the needle thread 114 therebetween.
Upon the reception of the predetermined number of phase angle signals S 2 , the CPU 211 controls the driving circuit 215 so as to reduce the driving current at a rate corresponding to the rotating speed of the arm shaft 128 as represented by a curve IP; consequently, the moving coil 205 is lowered gradually to increase the gap between the thread clamping wheel 164 and the thread clamping edge 156a as represented by a curve CP.
The rotating speed of the arm shaft 128 is determined through computation on the basis of the phase angle signals S 2 . Various CP curves for various rotating speeds are stored as a memory map in the ROM 212. The magnitude of the driving current is controlled momently through feedback control on the basis of the displacement signals given by the displacement sensor 201 in a mode as represented by the curve IP.
Similarly to the manner of control in the foregoing embodiments, the curves CP corresponding to the rotating speed of the arm shaft 128 are stored in the memory map of the ROM 212 to regulate the rate of increasing the gap between the thread clamping wheel 164 and the thread clamping edge 156a in proportion to the rotating speed of the arm shaft 128.
The magnitude of the driving current is controlled in the same manner to decrease the gap between the thread clamping wheel 164 and the thread clamping edge 156a in clamping the needle thread 114. The timing of driving the moving coil 205 is determined by counting the phase angle signals S 2 , and then the magnitude of the driving current supplied to the moving coil 205 is regulated through feedback control on the basis of the displacement signals according to a curve IQ so that the gap is decreased along a curve CQ stored in the memory map of the ROM 212.
Similarly to the curve MC for the second embodiment, a thin needle thread is released at a point EF 1 and is clamped at a point EC 1 , while a thick needle thread is released at a point EF 2 and is clamped at a point EF 2 as shown in FIG. 19.
The linear actuator 200 employed in this embodiment may be substituted by a stepping motor or the like.
|
In a conventional sewing machine, as the take-up lever is driven by the take-up lever crank, the take-up lever does not keep its uppermost position during the feed motion of a work fabric. Accordingly, the length of the thread path extending from the thread supply source to the eye of the needle varies remarkably during feed motion, and thus the needle thread equivalent to the amount consumed by stitch feed motion cannot be extracted from the supply source. In the present automatic needle thread supply control system, during a specific period from a time before finishing of each feed motion to a time when the needle reaches the throat plate, the take-up lever is held at its uppermost position. During a given period corresponding to the comparatively latter half of the specified period, thread supply stopping is released, whereby the needle thread equivalent to the amount consumed by each stitch feed motion can be extracted certainly from the supply source toward the take-up lever. The present thread supply control system comprises, at least, thread securing means or driving means, thread supply stopping means and mechanical control means.
| 3
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] This invention relates to a method and apparatus wherein an archery bowstring mounted peep sight is centrally located between separated bowstring fibers.
[0003] 2. Description of the Related Art
[0004] Prior to the present invention, as forth set in the general terms above and more specifically below, it is known in the archery bowstring mounted peep sight art to employ a single aperture peep sight.
SUMMARY OF THE INVENTION
[0005] Generally speaking, an embodiment of this invention fulfills these needs by providing an archery peep sight with a spherical sight body, in conjunction with a centrally located hour glass shaped aperture view port.
[0006] The above and other features of the present invention, which will become more apparent as the description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying drawings, wherein like characters represent like parts throughout the several views and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates an isometric view of a peep sight apparatus fixed in place on a bowstring, according to one embodiment of the present invention.
[0008] FIG. 2 illustrates an orthogonal side view of the peep sight apparatus, according to one embodiment of the present invention.
[0009] FIG. 3 illustrates an orthogonal front view of the peep sight apparatus, according to one embodiment of the present invention.
[0010] FIG. 4 illustrates a cross sectional side view of the peep sight apparatus, according to one embodiment of the present invention.
[0011] FIG. 5 illustrates an isometric view of the peep sight apparatus, according to one embodiment of the present invention.
[0012] FIG. 6 illustrates a cross sectional, orthogonal view of a peep sight apparatus mounted on a fully drawn bowstring. The apparatus is positioned normal to an archer's eye, according to one embodiment of the present invention.
[0013] FIG. 7 illustrates a cross sectional, orthogonal view of a peep sight apparatus mounted on a fully drawn bowstring. The illustration represents a bow possessing a different draw angle than that of FIG. 6 , according to one embodiment of the present invention.
[0014] FIG. 8 illustrates a cross sectional orthogonal view of a peep sight apparatus mounted on a fully drawn bowstring. The illustration represents a bow possessing a different draw angle than that of FIG. 6 and FIG. 7 , according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Traditionally, most common peep sights are of single piece design, with a single aperture port, and are mounted on the bowstring by means of separating the bow string fibers at the desired location. Most common prior art peep sights, are captured between separated bowstring fibers, thus fixing the device in place. Distinguishing itself from other prior art, the device of the present invention embodies four main features.
[0016] First, a primary sighting device is centrally located and fixed between separated bowstring fibers. Second, a sight body wherein the surrounding perimeter of the apparatus is geometrically spherical by design. Third, an aperture opening derived from dual apposing conical bores which form an hour glass shaped aperture view port. Finally, the apparatus is secured in place by means of opposing bowstring receptacle channels.
[0017] This design enables the sighting apparatus to maintain correct projected view of the peep sight to an archer, eliminating distortion of the sight geometry with respect to varying compound bow draw angles.
[0018] With reference first to FIG. 1 , there is illustrated an isometric view of a mounting convention as it relates a spherical peep sight apparatus 1 , mounted on a fully drawn bowstring. Apparatus 1 is mounted in place on bowstring 6 , by engaging opposing bowstring receptacle channels 3 c and 3 d ( FIG. 3 ), between separated bowstring fibers 6 e and 6 f . Apparatus 1 is secured in place along bowstring axial centerline, by means of upper and lower serving wraps 8 a and 8 b . Eye 7 and sighting vector 9 illustrate a user's line of sight through centrally located aperture view port 4 . Aperture view port 4 is comprised of primary conical bore 2 a , and secondary conical bore 2 b.
[0019] With reference to FIG. 2 , there is illustrated one orthogonal side view of apparatus 1 and bowstring receptacle channel 3 c.
[0020] With reference to FIG. 3 , there is illustrated one orthogonal front view of apparatus 1 , bowstring receptacle channel 3 c , and 3 d , primary conical bore 2 a , and centrally located aperture view port 4 .
[0021] With reference to FIG. 4 , there is illustrated one orthogonal, left side, cross section view of apparatus 1 and primary and secondary conical bores 2 a and 2 b converging and centered within spherical peep sight apparatus 1 . With reference to the FIG. 4 , there is shown cross hatching delineating section boundary 5 , conical bore 2 a and 2 b.
[0022] With reference to FIG. 5 , there is illustrated one isometric view of spherical peep sight apparatus 1 and primary and secondary conical bores 2 a and 2 b converging and centered within apparatus 1 . With reference to FIG. 5 , there is shown centrally located aperture view port 4 through spherical peep sight apparatus 1 .
[0023] With reference to FIG. 6 , there is illustrated one orthogonal cross section view of a mounting convention as it relates to the spherical peep sight apparatus 1 , mounted on a fully drawn bowstring, as mentioned above in FIG. 1 . FIG. 6 represents one embodiment of a draw angle variation wherein apparatus 1 is in a neutral position with respect to eye 7 and bowstring 6 is centered between draw angle indicators 12 k and 12 l . Projection lines 10 g and 10 h illustrate the true diameter of spherical peep sight apparatus 1 , as projected towards eye 7 . Projection lines 11 i and 11 j illustrate the true diameter of the aperture port, projected silhouette towards eye 7 .
[0024] With reference to FIG. 7 , there is illustrated one orthogonal cross section view of a mounting convention as it relates to the spherical peep sight apparatus 1 , mounted on a fully drawn bowstring, as mentioned above in FIG. 1 . FIG. 7 represents another embodiment of a draw angle variation, wherein apparatus 1 is rotated off neutral position with respect to eye 7 , and bowstring 6 is positioned at draw angle indicator 12 k . Projection lines 10 g and 10 h illustrate the diameter of spherical peep sight apparatus 1 , as projected towards eye 7 . As illustrated in FIG. 7 , projection lines 10 g and 10 h provide a true projection of apparatus 1 presented to eye 7 , which are undistinguishable geometrically from FIG. 6 projection lines 10 g and 10 h . Projection lines 11 i and 11 j illustrate the diameter of the aperture port, projected silhouette towards eye 7 . As illustrated in FIG. 7 , projection lines 11 i and 11 j illustrate minimal geometric distortion of aperture 4 as projected towards eye 7 , which are nearly undistinguishable geometrically from FIG. 6 projection lines 11 g and 11 h.
[0025] With reference to FIG. 8 , there is illustrated one orthogonal cross section view of a mounting convention as it relates to the spherical peep sight apparatus 1 , mounted on a fully drawn bowstring, as mentioned above in FIG. 1 . FIG. 7 represents another embodiment of a draw angle variation wherein apparatus 1 is rotated off neutral position with respect to eye 7 and bowstring 6 is positioned at draw angle indicator 12 l . Projection lines 10 g and 10 h illustrate the diameter of spherical peep sight apparatus 1 , as projected towards eye 7 . As illustrated in FIG. 8 , projection lines 10 g and 10 h provide a true projection of apparatus 1 presented to eye 7 , which are undistinguishable geometrically from FIG. 6 projection lines 10 g and 10 h . Projection lines 11 i and 11 j illustrate the diameter of the aperture port, projected silhouette towards eye 7 . As illustrated in FIG. 8 , projection lines 11 i and 11 j illustrate minimal geometric distortion of aperture 4 as projected towards eye 7 , which are nearly undistinguishable geometrically from FIG. 6 projection lines 11 g and 11 h.
|
An archery sighting device, comprising a spherical peep sight body in conjunction with a centrally located hour glass shaped aperture view port, which, substantially maintains its projected geometric integrity, throughout a range of varying draw angles.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to a a method of feeding substantially rectangular laundry articles to a laundry processing apparatus, such as an ironing roller, comprising spreading of the laundry article, as well as an apparatus for performing the method.
These apparatuses are primarily used in big laundries in which they are used for smoothing and spreading large laundry articles, such as sheets, table-cloths, slips for eiderdowns, etc. for subsequent insertion of the laundry article into e.g. an ironing roller, it being important that these feeding devices spread and smooth the laundry articles effectively so that undesired creases will not occur after the ironing roller. Most frequently, the laundry articles are inserted into the apparatus by a laundry article being taken from a pile of laundry articles in a wrinkled state and optionally wet or damp, following which the laundry article is inserted into the machine, which subsequently processes the laundry article so that it can be transferred to e.g. an ironing roller in a spread and smoothened state.
Numerous proposals for the construction of devices capable of performing the above-mentioned processes are known today. For example, U.S. patent specification 2 635 370 discloses an apparatus for smoothing and spreading large laundry articles, comprising two mutually engaged, narrow conveyor belts between which the laundry article may be inserted and hang down on each side of the lower conveyor belt, following which e.g. air jets may be applied to the surfaces of the article so that the article will flap and be smoothened while hanging in the apparatus. However, the apparatus cannot serve as a feeder, since the large laundry article has then to be manually removed from the apparatus and transferred to optionally an ironing roller. This means that the apparatus cannot at all meet the efficiency requirements made with respect to modern industrial laundries.
EP patent application 424 290 discloses a feeder proper, which comprises i.a. a short and very wide belt conveyor, across which the large laundry article is pulled into position on the belt conveyor from one end thereof, in that approximately the centre of an edge of the laundry article is inserted into grippers adapted for the purpose, said grippers pulling the laundry article into position across the belt conveyor. The laundry article will hereby typically be inclined across the belt conveyor, for which reason means are provided for aligning the laundry article so that two opposed edges on the laundry article are perpendicular to the travelling direction of the belt conveyor. In this situation, the laundry article hangs in a spread and smoothened state across the belt conveyor, there being provided a bar capable of transferring the laundry article from the belt conveyor to an optional, subsequent laundry processing apparatus, such as an ironing roller. However, this requires the laundry article to be positioned correctly before the transfer, which is ensured in that the belt conveyor advances the laundry article a certain distance. Thus, all the above-mentioned processes take place while the laundry article hangs across the belt conveyor, which means that a new laundry article cannot be inserted into the apparatus before the said processes have been completed, and accordingly there is a certain idle time for the operator before a new laundry article can be inserted into the machine.
The object of the invention is to provide a method and an apparatus which significantly reduce the operator's idle time and thereby enables a higher productivity per operator.
SUMMARY OF THE INVENTION
This object is achieved by providing a method of feeding substantially rectangular laundry articles to a laundry processing apparatus, such as an ironing roller, comprising spreading of the laundry article, characterized by positioning the laundry article in a stretched, folded and hanging state across a bar so that the greater part of the laundry article hangs down on one side of the bar and the folded part on the other, following which the laundry article, in the area at the fold, is caused to engage between two opposed conveyor faces which are resiliently engaged with each other and which subsequently pull the laundry article off the bar at said fold.
Also provided is an apparatus for feeding laundry articles to a laundry processing apparatus, such as an ironing roller, characterized by comprising a bar across which the laundry article is positioned in a stretched, folded and hanging state, as well as two opposite conveyor faces resiliently engaged with each other, and comprising means for inserting the bar with the laundry article between the two opposite conveyor faces, said conveyor faces being adapted such that the laundry article is pulled off the bar with its fold foremost and is then moved to an underlying conveyor face.
Since the laundry article is moved away from the bar as soon as it lies on it, the bar is quickly ready to insert a new laundry article. This makes it necessary for the laundry article to be transferred in the machine with a longitudinal crease, which is subsequently smoothened and may optionally be straightened subsequently at another location in the machine.
The invention hereby completely departs from the prejudice that the laundry article necessarily has to be spread completely and be straightened at one and the same location in the machine, which results in the above-mentioned idle times for the operator.
The invention additionally provides a method and an apparatus by means of which final smoothing of the laundry article takes place in a simple manner.
BRIEF DESCRIPTION OF THE DRAWINGS
An expedient embodiment of the invention will be described more fully below with reference to the drawing, in which
FIG. 1 is a perspective view of an apparatus according to the invention and of an operator,
FIG. 2a is a schematic sectional view of a detail in the apparatus of FIG. 1,
FIG. 2b is a view of the detail of FIG. 2a in another process position,
FIG. 3 is a view of the apparatus of FIG. 1 with a laundry article transferred in the machine with a fold, and
FIG. 4 shows the apparatus of FIG. 3 where the laundry article is smoothened.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is thus a schematic and perspective view of an embodiment of a feeder according to the invention. The machine is provided with two end gables 3 and 4 between which two conveyor belts 5 and 6 are located. The conveyor belt 6 extends partly below the conveyor belt 5, and the conveyor belt 6 is tightened by the rollers 8 and 10.
A bar 11, whose function will be described more fully below, is located below and straight in front of the rollers 7 and 8. An operator-operated insertion device is positioned at one end of the bar 11, as shown; the insertion device here consists of an underlying runway 12, above which two parallel conveyor belts 13 and 14 are positioned so as to be in firm engagement with the runway 12.
The operator starts the process by inserting the laundry article 2 between the conveyor belts 13 and 14 and the underlying runway 12, so that one corner 15 of the laundry article is positioned laterally of the conveyor belts 13 and 14, and so that a small portion of the edge of the laundry article 2 is stretched between the conveyor belts 13 and 14 and the underlying runway 12. The conveyor belts 13 and 14 are then activated to pull the laundry article 2 up to the bar 11.
The function and mode of operation of the feeder 1 will be described now as a series of individual processes according to the method of the invention.
FIG. 2a thus shows that the laundry article 2 is pulled across the bar 11, which is positioned below the rollers 7 and 8 that tighten the conveyor belts 5 and 6. This is done through the provision of a narrow conveyor belt 16 which extends the entire length of the bar, and which can thus pull the entire laundry article 2 into position on the bar 11. When the laundry article 2 is introduced at the end of the bar with one of the corners 15 of the laundry article 2, as stated above, the laundry article 2 hangs across the bar 11 with a minor or folded flap 18 bent across the bar 11.
This increases the efficiency of the apparatus since the operator, when inserting laundry articles into the apparatus does not have to find a central portion on one of the edges of the laundry article or two adjacent corners on the laundry article. Here the operator just has to find a corner on a laundry article and stretch a short portion of an edge adjacent the corner of the laundry article. This makes it simpler for the operator to handle the laundry article, which results in a further improvement in productivity.
Further, since the bar has a narrow conveyor belt having an upper conveyor face extending the entire length of the bar, this makes it possible to insert the laundry article in a simple manner from one end of the bar.
The bar 11 additionally comprises a slidable plate element 17 which extends in the entire length of the bar 11. As shown in FIG. 2b, the slidable plate element 17 is moved by means (not shown) up toward the rollers 7 and 8 of the conveyor belts 5 and 6, the conveyor belt 5 being caused to move in the direction of the arrow A, and the conveyor belt 6 being correspondingly caused to move in the direction of the arrow B. The movements of the conveyor belts 5 and 6 will cause a laundry article 2 with the bent flap 18 to be pulled up as the slidable plate element 17, is moved up between the rollers 7 and 8.
Thus the slidable plate 17 provides a particularly simple manner of transferring the laundry article to the conveyor 6, wherein the risk of possible wrinkles on the laundry article is reduced significantly.
The movements of the conveyor belts 5 and 6 will then bring the laundry article 2 with the bent flap 18 into a position in which the laundry article 2 is positioned, as shown in FIG. 3, on top of the conveyor belt 6. Since the laundry article 2 has now been removed from the bar 11, the operator can insert a new laundry article 2 already now and begin the process once more. Final smoothing of the laundry article 2 then takes place, as shown in FIG. 4 in that the continued movement of the conveyor belt 6 in the direction B shown in FIG. 2b causes the laundry article 2 to be moved toward the edge of the conveyor belt 6 which is defined by the roller 10, following which the bent flap 18 on the laundry article 2 drops beyond the edge, and the laundry article has hereby been completely straightened and smoothed.
The shown embodiment operates, as shown in the drawings, in such a manner that the flap 18 of the laundry article 2, on the conveyor belt 6, is bent outwardly and in a direction away from the conveyor belt 6. However, the invention will also operate satisfactorily, if the flap 18 of the laundry article 2 is bent inwardly and beneath the laundry article 2 and thus bent in a direction toward the conveyor belt 6.
It is clear that the embodiment described above and shown in the drawings may be varied in numerous ways. Thus, the insertion device may alternatively comprise a pair of grippers which retain the laundry article 2 in fundamentally the same way as is the case with the conveyor belts 13 and 14 and the runway 12. In addition, these grippers may be adapted so as to pull the laundry article 2 all the way across the bar 11, thereby making the conveyor belt 16 of the bar 11 superfluous.
As regards the conveyor faces in this structure, these may moreover alternatively be formed by optional roller paths, air cushion paths and the like, without departing from the idea of the invention.
However, a particularly simple and efficient embodiment is provided by the conveyor faces being opposite conveyor belts which flexibly engage each other. This provides a particularly good and safe control of the laundry article. Moreover, because the conveyor belts constitute the opposite conveyor faces as well as the underlying plane conveyor face, there is provided a particularly inexpensive and simple structure.
It will moreover be obvious to a skilled person to provide sequence control means and drive devices or means, etc. so that the feeder 1 can automatically perform the above-mentioned functions.
However, it should be noted that the embodiment shown in the drawing is unique in being particularly simple and inexpensive in structure, and tests with the feeder 1 have shown that an extremely high productivity is achieved with a single operator. It is even possible, if desired, that the same apparatus may be operated by several operators, there being provided a separate feeder for each operator.
|
A method and an apparatus for feeding substantially rectangular laundry articles to a laundry processing apparatus, wherein the laundry article can be positioned in a stretched, hanging and folded state across a bar, which is slidable between two opposed conveyor faces, which pull the laundry article off the bar with a fold so that the laundry article is quickly removed from the bar, thereby making it possible to quickly insert a new laundry article on the bar. A significantly increased productivity with a given number of operators can be achieved through the use of the method and the apparatus of the invention.
| 3
|
The present invention relates to polymers and copolymers of unsaturated carboxylic acids, in particular polymers and copolymers of acrylic acid and methacrylic acid and their derivatives.
BACKGROUND OF THE INVENTION
Homopolymers and copolymers of unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, maleic acid with other vinylidene monomers, are well known, as described in patent U.S. Pat. No. 2,798,053 and in subsequent patents on the same matter.
For example, subsequent patents U.S. Pat. No. 4,375,533, U.S. Pat. Nos. 4,419,502 and 4,996,274 disclose polymerizations carried out in different solvent systems, such as aromatic, hydrocarburic, halogenated, wherein said unsaturated acids polymerize by precipitation in the form of fine powders, which are subsequently dried, in order to be used as thickening and suspending agents in different industrial fields.
The solvents and monomers used in said patents however are toxic, and residue quantities in the obtained products hinder their use in the cosmetic and pharmaceutical field.
The possibility of using each of the solvents having a hydrogen bond number between 0.7 and 1.7 and solubility parameters between 8 and 15 is claimed in U.S. Pat. No. 4,267,103, in particular ethyl acetate is suggested when more than 3% by weight of monomer acids in the monomer mixture is in neutral form.
U.S. Pat. No. 4,758,641 claims the use of acetone and alkyl acetates, already cited in U.S. Pat. No. 4,267,103, used for the polymerization, but with a water content limited to 1% by weight to reduce the content of monomer residue under 0.2% in order to lower the toxicity of the finished product. Said solvents have a low grade of toxicity: nevertheless they are difficult to remove from the finished product which generally contains about 0.8% by weight of them, unless it is treated with prolonged drying systems at high temperature, whereby the polymer is degraded causing the formation of unwanted by-products.
Relying on the state of the art, then it is impossible to produce a polymer such as polyacrylic acid with a residue monomer content lower than 0.2% by weight and with a low-toxicity solvent residue whose content is below 0.8% by weight.
SUMMARY OF THE INVENTION
Surprisingly, it has been found that when ethyl formate is used as the solvent for the polymerization of the above monomers, wherein the mixture of monomer acids is neutralized even with less than 3% by weight or is not neutralized at all, the monomer residue in the finished product is even lower than 0.1% by weight, and the solvent residue is even lower than 0.15% by weight.
Moreover, the so obtained polymer shows a thickening capacity higher than the one obtained according to U.S. Pat. No. 4,758,641 and U.S. Pat. No. 4,267,103, at the same conditions.
Therefore, it is an object of the present invention to provide a process for the preparation of polymers and copolymers of acrylic acid and methacrylic acid and their derivatives characterized in that the polymerization is carried out in ethyl formate at a temperature ranging from 40° to 80° C., wherein the monomer mixture is up to 30% by weight of the whole polymerization mixture. It is another object of the present invention to provide a homopolymer or a copolymer both as such and as obtainable by the process according to the present invention, characterized in that they have a monomer residue content lower than 0.1% by weight and a solvent residue content lower than 0.15% by weight.
It is another object of the present invention to provide a method for thickening an aqueous composition which comprises the addition of a suitable amount of a polymer or copolymer of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The homopolymers and copolymers according to the present invention are obtained by polymerizing unsaturated carboxylic acids and/or their salts containing at least a double activated olefinic bond, polycarboxylic acids and their anhydrides.
The monomeric mixture is polymerized by precipitation from ethyl formate, thereby, after a vacuum drying, a polymer product in the form of powder is obtained.
Ethyl formate is a solvent having low toxicity and naturally occuring in food substances: it is admitted for the use in food as a flavouring agent, and it is included in the "GRAS" list of the substances generally known as safe. Moreover it has an oral LD 50 of 4290 mg/kg in the rat (Snyder, R (Ed.), Ethel Browning's Toxicity and Metabolism of Industrial Solvents. Second Edition vol. 3, Alcohols and Ethers. NY: Elsevier, 1992, 312) allows its classification among not noxious substances.
The monomeric mixture, other than main monomers, can include crosslinking agents. The main monomers are at least 95% by weight of the monomeric mixture, crosslinking agents are not more than 5% by weight of the monomeric mixture.
According to the present invention suitable monomers are monounsaturated acrylic acids having the following formula: ##STR2## wherein R 1 is hydrogen or methyl.
The monomer mixture can contain up to 5% by weight of crosslinking monomers containing at least two CH 2 ═CH-- groups selected from the group of the polyalkenyl polyethers having more than one alkenyl group per molecule.
Typical crosslinking monomers are: polyallyl pentaerythritol, polyallyl saccharose, trimethylol-propane diallyl ether, diallyl ethers of polyether diols having molecular weight between 50 and 1,000.
The polymerization solvent of this invention is ethyl formate; the amount of solvent must be such as the monomeric mixture is not more than 30% by weight of the whole polymerization mixture.
The polymerization in ethyl formate takes place generally in the presence of a radicalic initiator, in a closed reactor with inert atmosphere and with autogenous or artificially induced pressure, or in a open reactor at atmospheric pressure with solvent reflux.
The polymerization temperature is between 40° and 80° C., preferably between 40° and 60° C.
Suitable radicalic initiators are, for example, di(2-ethythexyl)peroxydicarbonate, di(sec-butyl)-peroxydicarbonate, di(cyclohexyl)peroxydicarbonate, di-(isopropyl)peroxydicarbonate, di(cetyl)peroxydicarbonate, di(t-butyl)peroxydicarbonate, di(n-propyl)peroxy-dicarbonate, di(t-butylcyclohexyl)peroxydicarbonate and the other similar peroxydicarbonates.
In order to have a more fluid polymeric mixture, part of the carboxylic groups of the used monomers can be neutralized before starting the polymerization or during the polymerization process, or salts of the carboxylic acids in the monomeric mixture can be used, such that less than 3% by weight of the carboxylic groups of the monomeric mixture is in the form of alkali or alkaline-earth metal salts, ammonium or alkylammonium salts.
The following examples further illustrate the invention, according to which the use of ethyl formate as the solvent system instead of a typical solvent among those mentioned in U.S. Pat. No. 4,758,641, such as ethyl acetate, yields polymeric powders containing lower solvent residue and having a higher viscosity of a 0.5% by weight aqueous solution neutralized with 10% NaOH solution, showing better thickening properties.
EXAMPLES 1-4
These comparison tests reproduce the conditions of the state of the art compared with what claimed in the present invention; Examples 1 and 2 are comparison examples representative of the solvents and of the operative conditions claimed in U.S. Pat. No. 4,758,641 and the solvent used is ethyl acetate, whereas Examples 3 and 4 are representative of the present invention and the solvent used is ethyl formate.
In the examples, acrylic acid was neutralized with potassium carbonate, and the obtained mixture was loaded in a 3 l reactor with a cooling jacket and stirrer. 800 g of solvent having 98.5% titre and with a water content lower than 200 ppm, the crosslinking agent (triallyl pentaerythritol) and the initiator (di(cetyl)peroxydi-carbonate) were added. The mixture was bubbled with a nitrogen flux for 30 minutes, then heated to 55° C. for about 8 hours. The reactor content was dried for 8 hours in a rotary vacuum equipment operating at 80° C.
Table 1 below shows the operating conditions and the properties of the polymers obtained, wherein AA indicates acrylic acid, APE indicates triallylpentaery-thritol and DCP indicates dicetylperoxydicarbonate.
TABLE 1__________________________________________________________________________ Viscosity Solvent MonomerTest K.sub.2 CO.sub.3 Solvent APE DCP sol. 0.5% Residue Residuen. AA (g) moles % (g) (g) (g) (CpS) (ppm) (ppm)__________________________________________________________________________1 145 2.16 800 2 1.45 14,000 8,800 1,2002 95 2.2 800 1.5 0.95 12,800 8,200 6003 145 2.16 800 2 1.45 38,000 1,300 6004 95 2.2 800 1.5 0.95 36,500 1,450 500__________________________________________________________________________
The polymers resulting from tests 1 and 2 contain more than 8,000 ppm (0.8% by weight) of solvent residue, and the 0.5% weight solutions, neutralized with a 10% NaOH solution, show a viscosity under 15,000 CpS. The polymers resulting from tests 3 and 4 contain less than of 1,500 ppm (0.15% weight) of solvent residue, and 0.5% weight solutions, neutralized with a 10% NaOH solution, show a viscosity higher than 35,000 CpS.
EXAMPLES 5 and 6
The following examples demonstrate that the properties claimed in the present invention are due to the use of ethyl formate independently of the operating conditions. Thus, the comparison test described in example 5 reproduces exactly the conditions described in example 4 of U.S. Pat. No. 4,758,641,and present example 6 instead discloses the use of ethyl formate as solvent, according to the present invention. In both examples, acrylic acid was neutralized with potassium carbonate, and the obtained mixture was loaded in a 3 l reactor with a cooling jacket and stirrer. 705 g of solvent having 99.5% titre and a water content lower than 200 ppm, the crosslinking agent (triallyl pentaeryithritol) and the initiator di(2-ethylhexyl)peroxydicarbonate were added. The mixture was bubbled with a nitrogen flux for 30 minutes, then heated to 50° C. for about 7 hours. The content of the reactor was dried for 12 hours in a rotary vacuum equipment operating at 80° C.
Table 2 below shows the operating conditions and the properties of the obtained polymers, wherein AA indicates acrylic acid, APE indicates triallyl pentaerythritol and DEEP indicates di(2-ethylhexyl)peroxydicarbonate.
TABLE 2__________________________________________________________________________ Viscosity Viscosity Solvent MonomerTest K.sub.2 CO.sub.3 Solvent APE DEEP sol. 0.5% sol. 1% Residue Residuen. AA (g) moles % (g) (g) (g) (CpS) (CpS) (ppm) (ppm)__________________________________________________________________________5 96.14 2.91 705 1.1 0.48 32,000 48,000 8,500 6006 96.14 2.91 705 1.1 0.48 36,500 66,000 1,450 500__________________________________________________________________________
According to the present invention, the polymer obtained in test n. 6 shows a higher viscosity for its neutralized solution both at 0.5% and at 1% concentration in water and a lower content of solvent residue with respect to the polymer obtained in comparison test n. 5.
The present invention is applicable to the industrial production of homopolymers and copolymers of acrylic acids and their derivatives. Said homopolymers and copolymers are useful as thickening and suspending agents in, particular in, cosmetic and pharmaceutical, textile, paper, inks and varnishes industries.
|
The present invention relates to a process for the preparation of crosslinked polymers and copolymers of acrylic acid and methacrylic acid of formula ##STR1## wherein R 1 is hydrogen or methyl. Said process, using ethyl formate as solvent, allows to obtain polymers having low residue of monomer and of solvent and with higher thickening capacity.
| 2
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.