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The present application is a continuation of U.S. application Ser. No. 09/553,573, filed Apr. 19, 2000 (now U.S. Pat. No. 7,462,195), which is incorporated herein by reference.
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 are made of an implant material that is other than bone and may or may not be resorbable. Where the implants are spinal fusion implants, they are adapted such that fusion occurs at least in part through the implants themselves. Where the implants are motion preserving for maintaining spinal motion, bone growth can occur at least in part into the spinal implants themselves, but not across them, and they are adapted to allow for relative motion between the vertebrae.
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.
Motion preserving implants maintain the spacing between the two adjacent vertebral bodies and allow for relative motion between the vertebrae. Bone growth from the adjacent vertebral bodies into the motion preserving implant, but not through the implant, anchors the implant to the adjacent vertebral bodies while preserving the relative motion between the vertebrae.
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, the width of the implant may be a limiting factor as to the height of the implant and therefore to the possible usefulness of the implant.
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 the 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 implants can be installed as part of a modular unit; and 5) the implants 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 the 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 aspects 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.
Implants for use in human spinal surgery can be made of a variety of materials not naturally found in the human body. Such materials include surgical quality metals, ceramics, plastics and plastic composites, and other such materials suitable for the intended purpose. Further, these materials may be absorbable, bioactive such as an osteogenic material, or be adapted to deliver and/or contain fusion promoting substances such as any of bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone, and/or others. 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 and 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 an artificial spinal implant formed or manufactured prior to surgery and provided fully formed to the surgeon for use in interbody fusion made of an implant material other than bone that is appropriate for the intended purpose. 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 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 material at the implant surface, increased load bearing support, increased stability, and 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 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 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 adapted for placement laterally. The interior and exterior facing side walls have an inner surface facing each other. The implants of the present invention also may 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 at 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. Where the spinal implant of the present invention is an interbody spinal fusion implant then it also may have at least one opening therethrough from the upper vertebral body contacting surface through to the lower vertebral body contacting surface. The opening allows for communication between the opposed upper and lower vertebrae engaging surfaces to permit for 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. The material of the implant is an artificial material such as titanium or one of its implant quality alloys, cobalt chrome, tantalum, or any other metal appropriate for surgical implantation and use as an interbody spinal fusion implant, or ceramic, or composite including various plastics, carbon fiber composites, or coral, and can include artificial materials which are at least in part bioresorbable. The implants may further include 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.
Bone for use as the base material used to form the implant is specifically excluded from the definition of artificial materials for the purpose of this application. Where the implants are for spinal fusion, it is appreciated that they 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.
BRIEF 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 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. 5A is a side elevational view of an implant having a tapered leading end in accordance with an embodiment of the present invention.
FIG. 5B is a side elevational view of an implant having opposed portions that are generally in a converging relationship to each other from a trailing end to a leading end of the implant in accordance with an embodiment of the present invention.
FIG. 5C is a side elevational view of an implant having opposed portions that are generally in a diverging relationship to each other from a trailing end to a leading end of the implant in accordance with an embodiment of the present invention.
FIG. 6A is a partial enlarged fragmentary view along line 6 A- 6 A of FIG. 5 .
FIG. 6B is a partial enlarged fragmentary view along line 6 B- 6 B 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. 9A 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. 9B is a top plan view of an implant in accordance with another 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. 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 FIGS. 9A and 9B 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 , 6 A, and 6 B, 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 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 . 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.
In another preferred embodiment, the opposed portions of the implant can be in moveable relationship to each other to allow for relative motion of the adjacent vertebral bodies after the implant is installed.
As illustrated in FIG. 9A , 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 point F to point B. While in the preferred embodiment as shown in FIG. 9A , 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, such as shown in FIG. 9B . 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. For example, at least a portion of the opposed surfaces may be in a diverging relationship to each other from the trailing end to the leading end for allowing angulation of the adjacent vertebral bodies relative to each other. Alternatively, at least a portion of the opposed surfaces may be generally in a converging relationship to each other from the trailing end to the leading end for allowing angulation of the adjacent vertebral bodies relative to each 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, when the leading end of the implant 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.
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An artificial interbody spinal implant adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies is disclosed. The implant has an asymmetrical leading end adapted to sit upon the more 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.
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CROSS-REFERENCE TO A RELATED APPLICATION
The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2005 054 863.6 filed on Nov. 21, 2005. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119 (a)-(d).
BACKGROUND OF THE INVENTION
Methods for manufacturing a stator winding for a stator of an electrical machine are known from the related art. In these methods, “unordered” windings are often manufactured, for reasons of cost. With this type of winding, it is possible to only approximate the subsequent position of the conductor in advance, since the stator winding is often wound onto winding stars, and the winding stars that are produced are then drawn into the stator. Since the configuration and shape, in particular, of the conductor in the winding overhang are not easily influenced, this type of winding is also referred to as a “wild” winding. It has been shown, however, that unordered windings create loud flow noise during operation, and cooling the conductor in the winding overhang evenly is not entirely possible. These disadvantages may be avoided using ordered windings, since, in this case, the conductors have defined positions. These ordered windings are manufactured as plug-in windings. This is a very laborious process, since the individual U-shaped sections of the winding—once they have been inserted in the stator core—must be bent into position and then welded, to establish the electrical contacts. One possibility for simplifying the manufacture of an ordered winding is described in patent application US 2004/0119362 A1 for the simple case of a single-layer wave winding.
SUMMARY OF THE INVENTION
With a method for producing a stator winding for a stator of an electrical machine, in particular for a motor vehicle, it is provided according to the present invention that the at least one segment of the stator winding is positioned in a plane, and that regions of the segment are bent toward one another along at least one folding line, thereby resulting in a lap winding. The unique characteristic of the method is that the segment is initially positioned in a plane. It should be understood, in particular, that the segment is located, placed, and/or formed in the plane, or it is produced in another manner. This is how the course of the segment within this plane is formed. Via the positioning, the segment in the top layer forms a certain path within the plane. At least one folding line, and usually several folding lines, which are located parallel to each other in particular, are defined within the plane. Regions of the segment are bent toward each other along at this at least one folding line. The topology of the segment in the plane was selected such that a lap winding is produced after the segment has been bent. The starting point, therefore, is a flat winding, in the case of which the segment—when in the flat state—may be offset and/or stamped particularly easily in any desired position. In the finished state, the segment then forms an at least two-layered structure, which is the stator winding for the electrical machine. Since a segment (for a phase) may be produced individually, the significance of this for an electrical machine with several phases is that they may be produced separately. A further advantage is that this is a multi-layered basic structure, i.e., much fewer offsets are required to obtain the finished state than is the case with a single-layer solution. A preferred variant for performing this method includes the following working steps:
1. Produce/position the flat segment 2. If necessary, stamp/offset the segment at the required points 3. Fold the segment along the at least one folding line.
The further processing of a stator winding produced in this manner is also particularly simple. Only the following steps are required:
1. Insert the winding in the stator core 2. Bend the stator core, if necessary 3. Shape the winding overhang, if necessary
An ordered lap winding may be produced very cost-effectively in this manner.
Advantageously, in the folded state, at least a first segment comes to rest in parallel with a second segment. Segments that are oriented relative to each other in this manner may be placed in the slots of the stator core later in a particularly easy manner. A “segment” is a section along the extension of a phase winding. The definition of a segment of this type may be purely virtual, i.e., it is not tied to any certain physical characteristics or to any particular interruption of the segment. However, the beginning or end of a phase winding section is often associated with the fact that the segment often changes direction within the plane, e.g., it bends sharply.
It is preferred that the positioning of a segment of the phase winding in a first direction of the plane corresponds to a slot number of a subsequent slot position of the phase winding section, and that the positioning of a phase winding segment in a second direction of the plane that is perpendicular to the first direction corresponds to a radial position of the phase winding segment within a slot. A convention of this type simplifies the understanding and realization of the topology of the segment that is required to obtain a certain lap winding. It is then particularly easy to define topologies of the segment, to interpret existing topologies, and to implement desired changes. The work performed based on this principle is explained in greater detail below with reference to the following exemplary embodiments.
Advantageously, the segment is positioned in the first direction in a serpentine manner, and/or it is positioned in the second direction in a wave-shaped manner. The serpentine structure ensures that the available plane is utilized in an optimal manner. The wave-shaped positioning in the second direction is a favorable possibility for obtaining the lap winding when the segment is folded.
Advantageously, regions in the plane are defined that make it possible to assign segments to at least one winding overhang or to a stator core. This means that, by selecting the topology of the segment, it is possible to specify which segments will lie in the slots of the stator core after the stator winding is produced, and which segments will form the at least one winding overhang.
According to a refinement of the present invention, one phase winding segment extends at a slant to the first and second directions in the regions that are assignable to a winding overhang. The technical effect of this procedure is apparent when the following stator winding is considered. For example, such a course of the segment results in the segment being guided further in another slot, and in the radial position of the segment changing within the slot relative to its previous position. A phase winding segment of this type will typically cross the fold line, since the change in the radial position may then be brought about in a particularly simple manner.
It is furthermore preferred that the course of a phase winding segment extend parallel to the second direction in the regions that are assignable to a stator core.
Advantageously, several segments that extend largely in parallel with each other are used to produce the stator winding. The production of a multi-phase stator winding of this type is realized very easily via repeated application of the method described above. To this end, several segments may be easily manufactured and placed in a magazine before the winding is folded. As soon as the required number of segments in the magazine has been attained, the segment is folded to form the stator winding.
The positioning of the segments is preferably designed as a distributed winding. In this manner, the crossings of individual segments are spacially offset, thereby simplifying the handling of the crossings.
According to a refinement of the present invention, one end of a phase winding segment that is assignable to a winding overhang leads into a different radial position within a slot than does the other end of this phase winding segment. As a result, the structure of the finished stator winding—which has at least two layers—may be deduced from the topology of the segments in the plane.
Advantageously, the number of segments that cross the fold line is equal to the number of slots of the assigned stator core. At least one segment is therefore assigned to each slot in the stator core.
It is also advantageous that, for the folded stator winding, the position of the phase winding segments within the slots changes in a radially progressive manner, and the direction of the radial progression is reversed at least one reversal point. This results in a realization of the multi-layered design with a particularly good structure.
It is particularly preferred to use a continuous wire for the segment. Even though it is basically possible to also form the segment out of several elements, which are then interconnected electrically, the unique characteristic of the present invention is that a continuous wire may be used. This simplifies manufacture and reduces production costs.
According to a refinement of the present invention, a rectangular wire is used for the segment. Particularly high stator fullness factors may be attained as a result. The winding produced with round wire may also be stamped in the slot region after production. This results in a high copper factor.
Advantageously, the diameter of the conductor, which forms the phase winding, essentially corresponds to the slot width of the slots in the stator core, or it is greater than the slot width. This prevents or reduces slippage of the conductor in the slots. The stator winding may also be used as an insertion winding for an “open slot” stator core (open slot=stator teeth without crests, and the winding in a round stator core is assembled from the inside).
The stator winding is preferably inserted into a flat core. The manufacture of the electrical machine is simplified as a result.
According to a preferred refinement of the present invention, the lengths of the phase winding segments located outside of the stator core vary, in particular in order to create a constant winding overhang height.
According to a further variant, one layer of the phase winding segments stacked in a slot extends markedly above the other layers, in order to perform a cooling function; this layer is slanted, in particular, toward the inner diameter of the stator. This allows air to flow around the outermost layer particularly well and cool it.
The present invention also relates to a stator winding for a stator of an electrical machine, in particular for a motor vehicle, in the case of which the stator winding is designed as a lap winding with at least two layers, using one of the methods described above. The stator winding advantageously has features that it may be attained by using one of the methods described above.
Finally, the present invention also relates to an electrical machine, in particular for a motor vehicle, in the case of which a stator winding of the machine is designed as a lap winding with at least two layers, using one of the methods described above.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be explained in greater detail with reference to the drawing.
FIG. 1 shows a flat winding with six phases, five conductors per slot, and 96 slots,
FIG. 2 shows a flat winding with six phases, four conductors per slot, and 96 slots,
FIG. 3 shows a flat winding with six phases, five conductors per slot, and 96 slots, designed as a distributed winding,
FIG. 4 shows a flat winding with three phases, five conductors per slot, and 48 slots,
FIG. 5 shows an intermediate step in the production of a 6-phase stator winding,
FIG. 6 shows an exemplary embodiment of a fully folded stator winding,
FIG. 7 shows different variants of the folding procedure, and
FIG. 8 is a symbolic depiction of the difference between a wavy structure and a serpentine structure.
DETAILED DESCRIPTION OF THE INVENTION
A first exemplary embodiment of a flat winding is shown in FIG. 1 . This is a stator winding 100 with six phases, five conductors per slot, and 96 slots. Stator winding 100 is shown in the unfolded state in this case. To limit the illustration to the essential features, only a portion of the region between slots 19 through 84 is shown. The winding continues in the not-shown region the same as it does in the region shown. Stator winding 100 is composed of six segments. Only first segment 102 , which begins with a segment start 104 in slot 1 , will be discussed here. These descriptions also apply for the further segments, which start in slots 2 through 6 . Segment 102 ends at segment end 106 in slot 91 . Fourfold lines 108 are shown, which extend across all slots. Entire stator winding 100 extends in an XY plane that has a first direction X and a second direction Y. The slots with their ordinal numbers are plotted in increasing order in the X direction. In the Y direction, the segments—including first segment 102 —are subdivided into several regions. A is a region of stator winding 100 that, in the folded state, will lie on the A side of the stator core (connection side), where it forms a first winding overhang. B refers to the second winding overhang, which is located on the “B” side, opposite to the first winding overhang. The regions on the B side are “upside down”. The regions of the segment that will eventually come to rest in the slots of the stator core are labeled “C”).
The course of first segment 102 will now be explained, along with the subsequent position of stator winding 100 in the stator core. Beginning with segment start 104 , segment 102 lies initially on the A side, and is guided through the stator core (region C) to the B side. It is assumed that the segment will come to rest in the innermost interior of the slot, i.e., next to the center of the stator. After segment 102 exits the stator core on the B side, it crosses a fold line 108 and is guided to slot 7 . After the obvious change of slots, which occurs when fold line 108 is crossed, segment 102 is now guided further in a different radial position within slot 7 than is the case in slot 1 . When counting starting from the innermost interior of the slot, segment 102 therefore switches from a first layer to a second layer. After this switch, segment 102 in slot 7 is guided through stator core (region C). On the A side, segment 102 is returned from slot 7 to slot 1 , and its radial position within the slot changes. The segment is now guided further in a third layer. Segment 102 is guided back through the stator core, switches slots and the radial position again on the B side, crosses the stator core again, switches from slot 7 to slot 1 , and crosses the stator core again, now in the fifth layer. Back on the B side, segment 102 is guided to a reversal point 110 . Reversal point 110 is described based on the Y direction. From reversal point 110 , segment 102 is now guided back, using slots 7 and 13 in an alternating manner. When viewed radially, segment 102 travels back from the fifth layer to the first layer. The radial direction of motion reverses once more, at reversal point 110 , and continues until segment 102 ends at segment end 106 in slot 91 .
Since the segments would come in contact with each other when the subsequent segments are positioned closed to reversal point 110 , segment 102 is now offset in the vicinity of its reversal point 110 . This means that, in this case, the segment portion leading away from reversal point 110 is located a bit lower in the XY plane than is the segment portion leading into reversal point 110 . As a result, the subsequent segments may be guided over the segment section leading away from reversal point 110 . After segment 102 is positioned in the XY plane accordingly, the five subsequent segments are positioned according to the same principle. The topology shown in FIG. 1 ultimately results.
In the next step, the segments are folded along fold lines 108 . In this case, segment regions 112 are folded toward each other, in the manner of an accordion (see FIG. 7 , a)). Basically, other types of folding techniques may also be used (see, e.g., FIG. 7 , c)). The creation of the windings in stator winding 100 is particularly easy to trace by drawing the topology of the segments on a piece of transparent foil and then folding it along fold lines 108 . The windings that are guided, e.g., through slots 1 and 7 , are then clearly visible when viewed from above. It also becomes obvious that segment portions in regions C come to rest in parallel with each other. Segment sections that are located on top of each other are placed in the same slot in the stator core.
As shown in the topology, it is clear that the segments are positioned in a serpentine manner in the first direction, and they are positioned in a wave-shaped manner in the second direction. The segments are guided in parallel up to the region of reversal points 110 , where crossovers must occur.
FIG. 2 shows a further exemplary embodiment of a flat winding, in this case with six phases, four conductors per slot, and 96 slots. To explain FIG. 2 , reference is made to the descriptions of FIG. 1 , which essentially apply here as well. Compared with FIG. 1 , which shows the embodiment of the present invention for an uneven number of conductors per slot, FIG. 2 shows the design for an even number of conductors per slot.
FIG. 3 shows a further exemplary embodiment of a flat winding, in this case with six phases, five conductors per slot, and 96 slots, in the embodiment as a distributed winding. The term “distributed winding” means that reversal points 110 are now spacially offset. This is made particularly clear in comparison with FIG. 1 . In FIG. 1 , six reversal points 110 are located very close to each other, and the individual groups of six reversal points 110 are each separated by a distinct distance. In comparison, two reversal points 110 in FIG. 3 form one group, and each group is separdated from the other. Spacial offsetting allows the manufacturing process to be simplified. In addition, the regular shape results in the advantage of low flow noise. To explain FIG. 3 , reference is made to the descriptions of FIG. 1 , which also apply here. Reference is made only to the special positioning of segment starts 104 ′, 104 ″ and segment ends 106 ′, 106 ″ of the third and four the segment.
A further exemplary embodiment Is shown In FIG. 4 . This is a flat winding with three phases, five conductors per slot, and 96 slots. To explain FIG. 4 , reference is made to the descriptions of FIG. 1 , which also apply here. This exemplary embodiment also demonstrates that the present invention may be used in a very flexible manner.
FIG. 5 now transitions from the general explanations of the present invention to a specific design of the segments. Three segments of a stator winding 100 are shown, which, in the finished state, will have a 6-phase design. The topology shown in FIG. 1 is based on the segments. Only first segment 102 will be discussed in the further explanation. In the specific embodiment, it is clear that the first segment includes one offset 114 or several offsets 114 at its reversal points 110 . It is therefore possible to position the individual segments in parallel, without their touching each other. In addition, intermediate pieces 116 serve to ensure that the segment may be guided in the winding overhang in a well-defined manner and without contact. Two fold lines 108 ′ and 108 ″ are used for this purpose between the layers.
FIG. 6 shows a fully-folded, six-phase stator winding 100 with all six segments. The transition into the individual layers and the handling of the crossovers at reversal points 110 are clearly shown. Stator winding 10 may be used directly as a flat winding for insertion into a flat stator core, which will be eventually bent into a round shape, or as an “open slot” winding, which is inserted using an inner mandrel from the interior into a round core.
FIG. 7 shows various possibilities for folding the segments placed in a plane. FIG. 7 a) is a five-layer configuration for five conductors per slot. The folding was carried out in the manner of an accordion. With b), the same folding technique is shown for a four-layer configuration. Part c) shows that the individual layers may also be folded around each other, thereby resulting in a spiral. Finally, with d), the same folding technique is shown for a four-layer configuration.
In FIG. 8 , the meaning of “serpentine” and “wave-shaped” is depicted symbolically. In region a), the serpentine positioning of one or more segments in the first direction, X, is shown. In comparison, the wave-shaped positioning in the second direction, Y, is shown in region b). The result is that these structures overlap in a known manner, thereby resulting in the exemplary embodiments described above.
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A method of producing a stator winding for a stator of an electrical machine includes positioning a phase winding segment of the stator winding in a same plane in a serpentine manner in a first direction (X) and in a shape of a wave in a second direction (Y) transverse to the first direction. The method includes bending regions (A, B, C) of the phase winding segment toward one another along a folding line to form a lap winding including positioning regions (C) parallel to each other connected by regions (B) where the regions (B) cross the at least one folding line ( 108 ). The phase winding is formed with a continuous wire.
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COPYRIGHT AND LEGAL NOTICES
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.
BACKGROUND INFORMATION
The present invention relates in general to input cancellation circuits, and more particularly to input cancellation in resistively coupled circuits.
Low noise resistively coupled circuits may need a small input resistor to ensure that the noise contribution of the input resistor does not dominate the overall noise of the system. The system may need to be isolated, for example, for calibration purposes. To isolate the input, a series switch may be used. However, if the series switch resistance is allowed to dominate over the input resistor, it may result in significant distortion during normal operation due to non-linear junction capacitances. If the series switch resistance is made small with respect to the low input resistance, the large physical size of the switch can introduce significant parasitic capacitance and reduce the bandwidth of the input circuits. Furthermore, if the input is allowed to exceed the supply voltage by more than the gate oxide breakdown of the series switch, then when the series switch is isolated, the oxide of the switch may be exposed to damage.
For example, FIG. 1 shows an input cancellation circuit 100 in accordance with prior art. It comprises an input 110 for receiving an input signal from an external source, a series resistance 130 coupled to the input 110 , a switch 140 which may be an NFET transistor, coupled to the series resistance 130 , and an output 120 coupled to the output of the switch 140 . The NFET used as a switch 140 can add substantial distortion during normal operation due to its non-linear junction capacitance. For a given channel length for the NFET 140 , the “ON” resistance is a function of the width or size of the NFET 140 . Thus, to reduce the “ON” resistance, the width of the NFET 140 needs be increased. However, as the size of the NFET 140 increases, the parasitic capacitance of the device increases with it, thereby reducing the bandwidth of the input circuits. Furthermore, if the input 110 is allowed to exceed the supply voltage by more than the gate oxide breakdown of the NFET 140 , then when the NFET 140 is isolated, the oxide of the NFET may be exposed to damage.
Thus, there is a need for a system and method for isolating an input without adding significant distortion and without significantly adversely affecting the bandwidth of input circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the figures of the accompanying drawings, which are meant to be exemplary and not limiting, and in which like references are intended to refer to like or corresponding parts.
FIG. 1 shows an input isolation circuit as may be used in the prior art.
FIG. 2 shows a block diagram of a single ended isolation method in accordance with an embodiment of the invention.
FIG. 3 shows a single ended input isolation circuit with a voltage controlled current source in accordance with an embodiment of the invention.
FIG. 4 shows a diagram of a single ended isolation method in accordance with an embodiment of the invention wherein the negative resistance path includes a resistance and a current controlled current source.
FIG. 5 shows a pseudo-differential input isolation circuit in accordance with an embodiment of the invention.
FIG. 6 shows a differential input isolation circuit in accordance with an embodiment of the invention.
FIG. 7 shows a differential input isolation circuit with a current controlled current source in accordance with an embodiment of the invention.
FIG. 8 shows a switch biasing means in accordance with an embodiment of the invention.
FIG. 9 shows an embodiment of a current controlled current source.
DETAILED DESCRIPTION
A system and method is provided for effectively isolating an input from a circuit. FIG. 2 shows a block diagram of a single ended isolation method in accordance with an embodiment of the invention. An input 210 is coupled to an input resistance 230 and a negative resistance 240 . The outputs of resistance 230 and negative resistance 240 are coupled to output 220 . By making the negative resistance path 240 substantially equal in magnitude to the resistance 230 , the signal at input 210 is effectively cancelled. For example, the current through resistance 230 Isig/2 and the current through the negative resistance 240 Isig/2 is equal but opposite in direction. Therefore, the current at the output 220 is 0, thereby effectively canceling the signal at input 210 . These relationships are summarized by the following equations:
Iout
=
V
Input
-
V
Output
R
-
R
R
-
R
=
-
R
×
R
R
+
(
-
R
)
If
R
=
-
R
❘
then
,
R
-
R
=
∞
,
and
Iout
=
0
As illustrated in FIG. 4 , the input resistance 230 may comprise a resistor 320 . The negative resistance path 240 may comprise a current controlled current source (CCCS) 325 with a gain substantially equaling −1 and a resistor 420 . In yet another embodiment, negative resistance path 240 may further comprise a switch 330 . It is understood that the switch 330 may comprise bipolar or FET transistors. For example, in one embodiment the switch may be an NFET or a PFET. The switch 330 may be turned “OFF” during normal operation, thereby allowing signals to travel from the input 210 through the resistance 230 to the output 220 . When the switch 330 is “ON,” the resistance 420 should match resistance 320 and the gain of the CCCS should be substantially equal to −1. The closer the resistance of the resistance 420 matches input resistance 320 and the gain of the CCCS equals −1, the less cancellation current inaccuracies arise. In another embodiment, the gain of the CCCS 325 may be non-unity if the total resistance of the negative resistance path 240 is scaled up or down such that the current through 230 is equal in magnitude and opposite in direction to the current through the output terminal of 240 , leading to output 220 . For example, if the total resistance of resistor 420 is 2 times the resistance of resistor 320 , then K may be scaled to −0.5 to compensate. The CCCS 325 may have a control 332 to isolate or enable the negative resistance path. Other terminals of the CCCS 325 include a first terminal leading to input 210 , a second terminal leading to output 220 , a third terminal connected to ground, and a fourth terminal connected to a control voltage 334 such that when the negative resistance 240 is enabled the voltage on output 220 is substantially equal to said control voltage 334 . Control 332 may be used instead of switch 330 or in addition to switch 330 .
In an alternative embodiment, a voltage controlled current source (VCCS) may be used instead of a CCCS. For example, FIG. 3 . shows a single ended input isolation circuit with a VCCS in accordance with an embodiment of the invention. The voltage across the input resistor R 320 is sensed by the VCCS 380 . If Gm of the VCCS is 1/R, then the current at the node 220 will be 0. Driver 370 represents the load of the negative resistance circuit. The following relationships summarize the operation illustrated in FIG. 3 :
Iout
=
Vin
-
Vout
R
+
Gm
(
Vout
-
Vin
)
if
Gm
=
1
R
then
Iout
=
0
as
desired
FIG. 5 shows a pseudo-differential input isolation circuit in accordance with an embodiment of the invention. It may comprise two systems 200 , 300 , or 400 . For example, in the pseudo differential circuit 500 , the top and bottom paths each comprise system 400 . The positive input 510 is coupled to the input of the top system 400 . Positive output 520 is coupled to the output of the top system 400 . Similarly, negative input 530 is coupled to the input of the bottom system 400 and negative output 540 is coupled to the output of the bottom system 400 . The arrangement in 500 accommodates differential signals wherein each end of the differential signal is cancelled single-endedly. The positive input of the differential signal may be applied to input 510 and the negative input to input 530 . During normal operation, switches 330 , if present, may be turned “OFF,” thereby allowing the differential signal to travel from inputs 510 and 530 to outputs 520 and 540 accordingly. When the switches 330 are turned “ON,” as explained, for example, in the description of system 400 of FIG. 4 , each end of the differential signal is cancelled, thereby canceling the differential signal. Instead of the switches 330 or in addition to, control signal 332 may isolate or enable the negative resistance paths.
FIG. 6 shows a differential input isolation circuit in accordance with a preferred embodiment of the present invention. Differential inputs, wherein the positive input is applied to input 610 and the negative input is applied to input 650 , are isolated by effectively canceling the differential input signal. Resistance 630 is coupled between the positive input 610 and the positive output 620 . This may represent the first input resistance path. Resistance 660 is coupled between negative input 650 and negative output 670 . This represents the second input resistance path. The path between the positive input 610 and the negative output 670 represents the first negative resistance path. Similarly, the path between the negative input 650 and the positive output 620 represents the second negative resistance path. The total resistance of the first negative resistance path is configured to substantially match the resistance of the first input resistance path. Similarly, the total resistance of the second negative resistance path is configured to substantially match the resistance of the second input resistance path. The closer the negative resistance path matches the input resistance path, the less cancellation current inaccuracies arise, leaving just common mode currents at the positive output 620 and negative output 670 accordingly. The first negative resistance path may comprise different components. For example, it may comprise a resistor 615 . Further, the first negative resistance path may comprise a switch 665 instead of resistor 615 or in addition to resistance 615 . Regardless of the number or type of components in the first negative resistance path, the magnitude of the resistance of the first negative resistance path should substantially match the first input resistance path.
The aforementioned description of the relationship between the first negative resistance path and the first input resistance path also applies to the relationship between the second negative resistance path and the second input resistance path. Thus, the second negative resistance path may comprise a resistor 655 . Further, the second negative resistance path may comprise a switch 625 instead of resistor 655 or in addition to resistor 655 . As in the first negative resistance path, the magnitude of the resistance of the second negative resistance path should substantially match the second input resistance path.
In a configuration where switches are included, as illustrated in the exemplary embodiment of FIG. 6 , switches 625 and 665 may be turned “OFF” during normal operation, thereby allowing signals to travel from the differential inputs 610 and 650 to the outputs 620 and 670 accordingly. Thus, the first side of the differential signal may travel from the input 610 through input resistance 630 to output 620 . Similarly, the second side of the differential signal may travel from the input 650 through input resistance 660 to output 670 . In one embodiment, switches 625 and 665 may be NFETs or PFETs.
As explained in the discussion above, the closer the negative resistance path matches the input resistance path, the better signal cancellation is achieved. When the negative resistance path includes a switch, for example an NFET or PFET, it must be configured such that the total of the “ON” resistance of the switch in addition to any other elements in the negative resistance path substantially match that of the input resistance path.
FIG. 8 illustrates an exemplary circuit which allows the resistance of the negative resistance path to substantially match that of the input resistance path. Input 860 coupled to resistor 870 which is connected in series to PFET 875 coupled to output 880 , represents a negative resistance path. The components within the dotted rectangle 802 are part of a dummy circuit which biases the gate of PFET 875 such that the negative resistance path substantially matches the input resistance path. Amplifier 825 senses the voltage at the output of resistor 820 , which represents an input resistance. Input resistance 820 is biased by current source 840 . The combination of the resistor 830 in series with the PFET 835 represents the negative resistance path. Since the voltage at the two inputs of an amplifier 825 are substantially similar, the output of the PFET 835 is forced to the same voltage as the output of input resistance 820 . Thus, the feedback loop forces the gate voltage of the PFET 835 to a level which effectively forces the source to drain resistance of PFET 835 to be such that the total resistance of resistor 830 and the source to drain resistance of the PFET 835 substantially match the resistance of the input resistor 820 . Now moving outside of the dummy cells of 802 , since the same gate voltage that is applied to PFET 835 is applied to PFET 875 as well, the total resistance of input resistor 870 and the drain to source resistance of PFET 875 will substantially match the input resistance 820 . The drain of PFET 875 and the drain of PFET 835 are substantially at the same voltage. Further, the Vdd 810 is the common mode voltage that is seen at input 860 . This approach may further benefit from a common mode correction circuit which senses the output 880 and forces it to a common mode level by either sourcing or sinking current through the input resistor 870 .
FIG. 7 shows a differential input isolation circuit in accordance with a preferred embodiment of the invention. The system 700 may comprise elements similar to system 600 of FIG. 6 except that in system 700 the switches 625 and 665 are removed and system 700 further comprises a CCCS 750 and CCCS 751 . One of the benefits of using CCCS 750 and CCCS 751 is that it may prevent potential damage to switches 625 and 665 as compared to the embodiment illustrated in FIG. 6 . In one embodiment, switches 625 and 665 may be NFETs or, alternatively PFETs. For example, referring to FIG. 8 to illustrate, when PFET 875 is turned “OFF,” the source of the PFET 875 tracks the input 860 which may go above the supply, thereby turning on the inherent parasitic source to bulk diode of the PFET 875 , which is undesirable. If PFET 875 is replaced with an NFET and the NFET is turned “OFF,” the drain to gate junction of the NFET may be exposed to the signal from input 860 which, depending on the sensitivity of the NFET and the magnitude of the input signal, may damage the junction. The use of CCCS 750 and 751 , as illustrated in FIG. 7 , does not need to rely on, for example, NFETs or PFETs to be used as switches, thereby further improving the reliability of the input cancellation circuit. There may be a control 780 to isolate or enable the cancellation of the signals at input 610 and input 650 .
There are different ways that one skilled in the art may implement a CCCS. FIG. 9 shows an example of a CCCS as may be used in an embodiment of the input cancellation circuit. The CCCS circuit may comprise PFETs 910 , 915 , 920 , 925 , 930 , 940 945 , and 935 , NFETs 950 , 955 , 960 , and 965 , and Op-Amp 970 . The system 900 conveys substantially the same current to output 990 that it senses at input 980 when it is configured with unity gain. Similarly, the same current at output 995 is supplied that is sensed at input 985 . The output currents at 990 and 995 are cross coupled to provide a differential sign inversion and hence a CCCS gain substantially equal to −1 and may also provide common mode correction. The CCCS 900 may, for example, replace the CCCS 750 and 751 of FIG. 7 .
Although the present invention has been described with reference to particular examples and embodiments, it is understood that the present invention is not limited to those examples and embodiments. For example, ones skilled in the art may use bipolar devices instead of FETs. The present invention as claimed, therefore, includes variations from the specific examples and embodiments described herein, as will be apparent to one of skill in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
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A system and method are provided for isolating an input without adding significant distortion and without significantly adversely affecting the bandwidth of input circuits. In one embodiment, a single ended signal is substantially cancelled by an arrangement including an input resistance path in parallel with a negative resistance path wherein both paths substantially match in resistance. In another embodiment, a differential signal is substantially cancelled by a pseudo differential arrangement including two independent input resistance paths each in parallel with a corresponding negative resistance path, wherein the resistance paths substantially match the input resistance paths. In yet another embodiment, a differential signal is substantially cancelled by a differential arrangement including two resistance paths wherein a first negative resistance path is coupled between the first differential input and the second differential output and the second negative resistance path is coupled between the second input and the first output. In yet another embodiment, a current controlled current source may provide the negative amplification for the negative resistance path.
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FIELD OF THE INVENTION
This invention relates to the corrugation of a slab of wet fibrous pulp. More particularly, it relates to a method and apparatus for corrugating the upper surface of a wet slab shortly after its deposition from a headbox. The invention also relates to the corrugated wet slab, itself, which retains the linear lands and grooves when dried for use as a decorative sound absorbing panel.
BACKGROUND OF THE INVENTION
A molding composition comprising a wet pulp of mineral fibers and a binder was taught in U.S. Pat. No. 1,769,519. The owner of that patent, United States Gypsum Company, has been selling a premium line of sound absorbing tiles made according to the '519 process under its ACOUSTONE trademark for more than fifty years. A rough, stone-like appearance is achieved by a casting and screeding technique. It has proven difficult to generate linear patterns on the wet pulp uniformly and reproducibly at commercially feasible costs.
The creation of linear patterns in a highly fibrous acoustical tile is often achieved by routing or sandblasting of the dry blanks. Each of these requires special equipment and expertise. Molding of the tile is conditioned upon the pulp remaining in the mold while some change, e.g. curing, drying, or setting, causes the features of the pattern to become self-sustaining.
A plastic plaster composition containing as much as 30% by weight of natural fibers is taught in U.S. Pat. No. 3,852,083 as being extrudable and moldable. Consistently good results are obtained only when a latex and a hydromodifier such as methyl cellulose are present along with the plaster and fiber. The hydromodifier enables the composition to leave the extrusion die as a smooth homogeneous column whose dimensions remain the same as the die opening. The structures obtained by the extrusion are said to be generally shape-retaining but the desirability of supporting them against deformation by gravity is also taught.
Page et al teach in U.S. Pat. No. 3,298,888 a process and apparatus for high speed, low cost manufacture of a ribbed gypsum board having paper faces. A slurry of calcined gypsum which may contain fibers is introduced between a flat bottom sheet and a pleated upper sheet in sufficient volume to fill the pleats and thereby form the ribs. The paper remains on the gypsum even after it has set, the height of the ribs having been gauged to a uniform value while the slurry has partially set but is still plastic.
It is an object of this invention, therefore, to provide a method for creating well-defined linear textures in a moving slab of wet fibrous pulp.
It is another object of this invention to provide apparatus for corrugating the surface of such a slab.
It is a further object of this invention to provide a wet pulpy slab of fibers having discrete, self-sustaining linear impressions in its surface ranging from that of a keyboard to a checkerboard to a corduroy fabric.
These and other objects are achieved by the method and apparatus described herein with reference to the drawings.
SUMMARY OF THE INVENTION
Now, it has been discovered that a wet pulpy mass of mineral fibers, wood fibers, or the like may be corrugated by forcing a slab of the pulp against a texturing skid having corrugations co-directional with the movement of the slab, thereby impressing discrete lineal grooves and lands on the surface of the pulp.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of apparatus of this invention showing a wet fibrous pulp supported by pulp carriers being corrugated soon after its exit from a head box.
FIG. 2 is a cross section of the apparatus of FIG. 1.
FIG. 3 is a cross section of a preferred texturing skid of this invention.
FIG. 4 is a sectional view of the skid of FIG. 3 taken along line 4--4 thereof.
FIG. 5 is a sectional view taken along line 5--5 of FIG. 1.
FIG. 5a is an alternative sectional view taken along line 5--5 of FIG. 1.
FIGS. 6 and 7 are perspective views of two embodiments of a texturing skid of this invention.
FIGS. 8, 9 and 10 are cross sections of three other embodiments of the texturing skid of this invention.
FIG. 11 is a perspective view of another embodiment of the corrugating apparatus of this invention.
FIG. 12 is a diagrammatic view of a jack in association with a texturing skid of this invention.
FIG. 13 is an exploded perspective view of the jack of FIG. 12.
FIG. 14 is a plan view showing the apparatus of claim 1 disposed at right angles to a second corrugating device.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, the wet pulp 10 is distributed by the head box 12 across the breadth of the pulp carrier pans 14 which are transported by the conveyor belt 16 at a line speed of about 40 to 55 feet per minute. The pulp is forced against the corrugated texturing skid 18 which inclines from the pintles 20 toward the wet pulp 10 downstream from the head box. The corrugated surface 22 of the skid 18 is the negative of the pattern impressed on the wet pulpy slab 23. The forcing of the pulp into the grooves 24 and around the lands 25 is shown more clearly in FIGS. 2, 5 and 5a. A partial filling of the grooves as in FIG. 5 may be desired for its natural stone look or a more sculptured appearance may be had by filling them fully as in FIG. 5a.
The mounting of the stationary skid 18 is shown in FIG. 2 wherein the pintle 20 stands on the ledge 26 which projects from the head box 12 just above the gate 28. The socket 30 capping the pintle 20 is connected to the skid 18 by the angle irons 31 and 32 and their respective fasteners. The socket 30 is free to articulate around the pintle in all directions to accomodate movements of the skid in response to the flow of the wet pulp 10 against the skid.
The bending member 34, shown in more detail in FIGS. 3 and 4, spans the breadth of the skid 18 and attached at the middle region thereof is the base leg 35 of an angle iron. The connector nuts 36 are attached to the upright leg 37 of the angle iron by the bolts 38 and they project out over the base leg 35 which has a hole 39 near each of the opposite ends thereof. The adjusting screws 40 engage the threaded bores 41 through the nuts 36 and pass freely through the holes 39 to urge the lateral ends 42 of the skid 18 away from the leg 35 and thus cause the corrugated surface 22 to become slightly concave to register with the slightly convex surface of the wet pulp 10.
The various patterns that may be imparted to acoustical tile by this invention are exemplified by those of the skids 18a-18e in FIGS. 5-10. A preferred pattern for the corrugations on the skid 18e is shown in FIG. 10 wherein the profile of each groove 24 is an arc of a circle along with a tangential extension thereof at each end of the arc. The tangents to adjacent circular segments intersect with one another and the vertex formed thereby constitutes the profile of a land 25. The greater the angle between the tangents, the broader will be the profile of a land. Said profiles facilitate complete packing of the wet pulp into the grooves and afford strong lands which can withstand the lateral forces of the packing. A vertex of 60° as shown in FIG. 10 is suitable, as are others from about 30° to 90° or more. Lands as thin as about 1/64 of an inch may be used, however.
A serpentine corrugation may be imparted to the wet pulpy slab by reciprocating the skid 18 which is mounted on the linear bearings 44 which slide on the horizontal shaft 45 and are connected by the rod 47 which in turn is connected to the reciprocating arm 48 and the motor 49 as in FIG. 11.
The angle of inclination of the skid 18 may be conveniently and reproducibly adjusted up to about 30° by operation of the jack 50 shown in FIGS. 12 and 13. The base 51 is welded to the upright body 52 which has the partially threaded bore 53. The tube 54 along with its cap 55 envelop the upright body and the hole 56 in the cap is aligned with the bore 53 to allow passage of the screw 57 which engages the threads therein. Surrounding the upper end of the screw and fastened thereto by the set screw 58 is the collar 59 which bears against the underside of the cap 55. The crank 60 is integral with the screw. Welded to the tube 54 is the L-shaped bracket 61 upon which the mounting pin or pintle 20 is mounted. The jack 50 is mounted on the angle iron 62 which in turn is supported by the brackets 63 which extend from the head box 12 on both lateral sides of the conveyor belt 16. Alternatively, angle iron 62 may be supported by uprights spaced away downstream from the headbox. Precise and reproducible adjustments of the height of the leading edge 64 of the skid 18 may be made by turning the crank 60 to raise or lower the pintle 20 and the socket 30. It is preferred to use a jack at each lateral margin of the skid.
A grid pattern or checkerboard impression may be created by bumping the corrugated wet slab 23 off of the conveyor belt 16 onto a second conveyor belt 16a which moves at right angles to the belt 16 and forcing the wet pulp into the grooves and around the lands of a second texturing skid 18 as shown in FIG. 14.
Two effects of the friction generated by the rough mineral fibers in the wet pulp as it is forced against the surface 22 of the skid 18 by the movement of the conveyor belt 16 are a wearing away of the surface and a slowing of the conveyor belt speed. To minimize those effects, the skid 18 or at least the surface 22 is preferably made of a low friction material such as high density polyethylene, an ABS plastic, or poly-(tetrafluoroethylene) sold under the trademark TEFLON by duPont. A wear resistant material such as a chrome-plated metal or plastic is particularly preferred. The area of contact between the wet pulp and the surface 22 should be minimized to the extent consistent with a sharp definition of the lands and grooves. The length of the surface 22 in the machine direction has been as small as about 1 inch (25.4 mm) when corrugating a wet slab having a 2 foot (61 cm) width but longer machine direction lengths are more suitable when the grooves 24 are very narrow and close together. Grooves as narrow as about one-eighth inch (3.2 mm), measured from vertex to vertex on the skid 18e for example, have been used in the practice of this invention. When such narrow grooves are spaced closely together, the total area to be packed with the wet pulp in a short time is rather large and it is useful to press down on the skid to help the packing. A hydraulic press may be connected to the skid 18 or weights may be simply laid on it to impose a load of up to about 1 psi. The skid is in contact with the wet pulp for from about 1 second to about 6 seconds.
The low angle of inclination of the skid 18 is another feature of the invention designed to minimize the wear on the surface 22 and the drag on the conveyor. A plow-like action by the skid is not acceptable because that would tear up the fibrous pulp but a large vertical vector for the position of the skid is also to be avoided because that would tend to block passage of the pulp rather than let it slip into the grooves and move within them until they are fully packed. A skid having an upswept leading edge also allows the wet pulp to slip into the grooves at a shallow angle. The radius of curvature is suitably about 3 inches but it may be greater. Such a skid is disposed above the pulp carrier and substantially parallel thereto so that the major planar portion of the skid glides on the wet pulp deposited on the carrier.
Although the wet pulp has been discussed with reference to mineral fibers and particularly to granulated mineral fibers as taught in U.S. Pat. No. 1,769,519, which is incorporated herein by reference, this invention is also suitable for the corrugation of wet wood fiber pulps and other highly fibrous masses having flow properties similar to the pulp of the '519 patent. A highly fibrous mass, for the purposes of this invention, is one containing from about 6% to about 25% or more fiber by weight of the wet mass. A typical pulp contains about 21% mineral fiber, about 72% water, about 3% stucco and about 4% starch by weight.
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A wet pulp of mineral fibers or the like is forced between a pulp carrier and a corrugated texturing skid inclined toward the downstream end of a moving slab of the pulp. The corrugations of the skid are co-directional with the machine direction of the conveyor belt that transports the pulp under and beyond the skid.
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This application is a 371 of PCT/JP2014/001550 filed 18 Mar. 2014.
TECHNICAL FIELD
The invention relates to a sheet-manufacturing device and a method for controlling a sheet-manufacturing device.
BACKGROUND ART
In the related art, since waste paper discharged from offices includes waste paper having confidential matters, in view of confidentiality, it is preferable that the waste paper is processed in the offices. Since a wet sheet-manufacturing device using a large quantity of water is not suitable in a small office, a dry sheet-manufacturing device having a simplified structure is suggested (for example, see PTL 1).
CITATION LIST
Patent Literature
PTL 1: Japanese Unexamined Patent Application Publication No. 2012-144819
SUMMARY OF INVENTION
Technical Problem
However, in the sheet-manufacturing device described above, there has been a problem in that, for example, if the temperature of a defibrating unit that defibrates paper (waste paper) changes, air density changes, transportation force by the airflow is caused to not be constant, and thus the defibrated state becomes unstable. This is a problem that is not limited to waste paper but also occurs even in a case where other raw materials are defibrated.
Solution to Problem
The invention is to solve at least a unit of the problem described above, and can be performed by the following embodiments or application examples.
APPLICATION EXAMPLE 1
According to this application example, a sheet-manufacturing device including: a defibrating unit configured to generate a defibrated material by defibrating a defibration object; a temperature acquiring unit configured to acquire a temperature of the defibrating unit; and a control unit configured to change a mass flow rate of the air including the defibrated material transported from the defibrating unit.
According to this configuration, since the mass flow rate of the air including defibrated materials is changed based on the acquired temperature of the defibrating unit, the change of the mass flow rate of the air generated by the change of the temperature of the defibrating unit can be adjusted, such that defibration can be stably driven. Accordingly, the defibrated state becomes stable, such that an excellent sheet can be manufactured.
APPLICATION EXAMPLE 2
In the sheet-manufacturing device according to the application example above, when the acquired temperature is higher, the control unit causes the mass flow rate to be higher than that when the acquired temperature is lower.
When the temperature of the defibrating unit is higher, the density of the air decreases, such that the transportation properties of the defibrated materials decrease. Then, an excessive defibrated state in which fibers are more defibrated progresses, fibers become short, and thus the strength of the sheet that is formed decreases. Therefore, according to this configuration, if the temperature of the defibrating unit is higher, the transportation properties of the defibrated material can be increased by causing the mass flow rate to be greater than that when the temperature of the defibrating unit is lower. Accordingly, the excessive defibratied state can be cancelled.
APPLICATION EXAMPLE 3
The sheet-manufacturing device according to the application example above further includes a suction unit that configured to suction the defibrated material, in which when the acquired temperature is higher, the control unit configured to cause a suction force of the suction unit to be greater than that when the acquired temperature is lower.
According to this configuration, if the acquired temperature is higher, the mass flow rate of the air can be caused to be significant by causing the suction force of the suction unit to be significant. Accordingly, the transportation properties of the defibrated material can be increased.
APPLICATION EXAMPLE 4
In the sheet-manufacturing device according to the application example above, the defibrating unit includes a rotary blade that rotates, and when the acquired temperature is higher, the control unit configured to cause a rotation speed of the rotary blade to be greater than that when the acquired temperature is lower.
According to this configuration, if the acquired temperature is higher, the mass flow rate of the air can be caused to be great by causing the rotation speed of the rotary blade to be greater, such that the transportation properties of the defibrated material can be increased.
APPLICATION EXAMPLE 5
In the sheet-manufacturing device according to the application example above, the temperature acquiring unit configured to acquire the temperature inside the defibrating unit.
According to this configuration, since the temperature inside the defibrating unit can be acquired, the temperature can be easily acquired.
APPLICATION EXAMPLE 6
In the sheet-manufacturing device according to the application example above, an upstream side and a downstream side of the defibrating unit in a transporting direction of the defibrated material are connected to an upstream transporting path and a downstream transporting path, respectively, and the temperature acquiring unit configured to acquire temperatures inside the upstream transporting path and inside the downstream transporting path.
According to this configuration, since the temperatures of the upstream side and the downstream side of the defibrating unit are obtained, the temperature can be easily acquired.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram schematically illustrating a configuration of a sheet-manufacturing device.
FIG. 2 is another diagram schematically illustrating the configuration of the sheet-manufacturing device.
FIG. 3 is a diagram schematically illustrating a configuration near the defibrating unit.
FIG. 4 is a flow chart illustrating a method for controlling a sheet-manufacturing device.
DESCRIPTION OF EMBODIMENTS
Hereinafter, embodiments of the invention are described with reference to the drawings. In addition, in the respective drawings, in order to cause the respective members to be recognizable, dimensions of the respective members are illustrated to be different from those in reality.
First, configurations of a sheet-manufacturing device are described. The sheet-manufacturing device is based on, for example, a technique of reproducing a raw material (defibration object) such as waste paper (used paper) or a pulp sheet into a new sheet. Also, the sheet-manufacturing device includes a defibrating unit that generates a defibrated material by defibrating a defibration object, a temperature acquiring unit that acquires a temperature of the defibrating unit, and a control unit that changes the mass flow rate of the air including the defibrated material transported from the defibrating unit. In addition, a raw material as a defibration material to be supplied to a sheet-manufacturing device according to the embodiment is, for example, waste paper (raw material PU) such as A4 size which is typically used in offices, recently. Hereinafter, specific descriptions are provided.
FIGS. 1 and 2 are diagrams schematically illustrating a configuration of a sheet-manufacturing device. As illustrated in FIGS. 1 and 2 , a sheet-manufacturing device 1 includes a supplying unit 10 , a crushing unit 20 , a defibrating unit 30 , a classifying unit 40 , a receiving unit 45 , an additive agent feeding unit 60 , a forming unit 70 , a moisture spraying unit 120 , a pressurizing unit 80 , a heating and pressurizing unit 90 , and a cutting unit 100 . The sheet-manufacturing device 1 further includes a temperature acquiring unit 110 that acquires a temperature of the defibrating unit 30 and a blower 34 that adjusts the mass flow rate of the air. Also, the sheet-manufacturing device 1 includes a control unit (not illustrated) that controls these members.
The supplying unit 10 is to provide the raw material PU as a product to be defibrated to the crushing unit 20 . The supplying unit 10 includes, for example, a tray 11 that disposing the plural raw materials PU in an overlapped manner and an automatic feeding mechanism 12 that can continuously insert the raw materials PU disposed in the tray 11 into the crushing unit 20 .
The crushing unit 20 cuts the supplied raw material PU into squares strips of several centimeters. The crushing unit 20 includes a crushing blade 21 , and configures a device in which the cutting width of a blade of a general shredder is widened. Accordingly, the supplied raw materials PU can be easily cut into strips. Also, the strips are supplied to the defibrating unit 30 via an upstream transporting path 25 .
The defibrating unit 30 includes a rotary blade that rotates and defibrates the strips supplied from the crushing unit 20 so as to have fiber shapes (cotton shape). In addition, the defibrating unit 30 according to the embodiment performs dry defibration in the air, not defibration in water.
For example, a disc refiner, Turbo Mill (manufactured by Freund-Turbo Corporation), Ceren Miller (manufactured by Masuko Sangyo Co., Ltd.), and a dry defibration device including a wind generating mechanism are appropriately applied to the defibrating unit 30 . The size of strips inserted to the dry defibrating unit 30 may be the same size as those discharged by a general shredder.
Printed ink or toner, anti-bleeding materials, or other coating materials on the raw material or the like are also released (separated) from a state of being attached on the fiber by a defibration process of the defibrating unit 30 (hereinafter, referred to as “ink particles”). Accordingly, the defibrated material discharged from the defibrating unit 30 is fibers and ink particles obtainable by defibrating the strips.
Also, the defibrating unit 30 is a mechanism that generates airflow by the rotation of the rotary blade such that the defibrated material moves in the defibrating unit 30 . A downstream transporting path 35 that transports the defibrated materials by causing the defibrated materials to ride on the airflow is provided between the defibrating unit 30 and the classifying unit 40 , and the blower 34 that controls the speed of the airflow is arranged in the downstream transporting path 35 . The defibrated material is transported to the classifying unit 40 at a speed appropriate for being classified by the blower 34 . The blower 34 may have a function of suctioning the defibrated materials from the defibrating unit 30 . In this case, the blower 34 becomes a suction unit. In addition, another suction unit may be included between the blower 34 and the defibrating unit 30 . The suction unit can control the suction force. The amount of the defibrated materials that move in the defibrating unit 30 can be controlled by controlling the suction unit such as the blower 34 , such that the mass flow rate of the air including the defibrated materials can be controlled.
FIG. 3 is a diagram schematically illustrating a configuration near the defibrating unit. Here, a first thermometer 113 , a second thermometer 114 , and a third thermometer 115 , as the temperature acquiring unit 110 that acquires the temperature, are provided near the defibrating unit 30 .
As illustrated in FIG. 3 , the first thermometer 113 that acquires the temperature of the defibrating unit 30 is provided in the defibrating unit 30 . The first thermometer 113 measures the temperature inside of the defibrating unit 30 . In addition, the second thermometer 114 that measures the temperature inside the upstream transporting path 25 and the third thermometer 115 that measures the temperature inside the downstream transporting path 35 are provided in the upstream transporting path 25 and the downstream transporting path 35 , respectively connected to the upstream side and the downstream side of the transporting direction of the defibrated materials of the defibrating unit 30 .
Also, the suction amount of the blower 34 as the suction unit is controlled in response to the temperatures acquired by the first thermometer 113 , the second thermometer 114 , and the third thermometer 115 .
The classifying unit 40 classifies the transported defibrated materials into the ink particles and the fibers, such that the ink particles are removed. A cyclone 40 , as the classifying unit 40 , according to the embodiment is applied. As the cyclone 40 , a tangential line input-type cyclone has a comparatively simple structure, and is preferable. In addition, instead of the cyclone 40 , another kind of the airflow-type classifier may be used. In this case, as an airflow-type classifier other than the cyclone 40 , for example, an Elbow-jet or an Eddy Classifier can be used. The airflow-type classifier generates the turning airflow, and performs separation and classification according to the difference of the centrifugal forces received depending on the size and the density of the defibrated material such that the classification point can be adjusted by the speed of the airflow and the adjustment of the centrifugal force.
The cyclone 40 according to the embodiment includes an introduction port 41 introduced from the defibrating unit 30 , a cylindrical portion 43 to which the introduction port 41 is connected in a tangential direction, a conical portion 42 that extends to the cylindrical portion 43 , a lower output port 46 provided on the lower portion of the conical portion, and an upper exhaust port 44 for discharging fine powder which is provided on the central and upper portion of the cylindrical portion 43 .
In the classification process, the airflow carrying the defibrated materials introduced from the introduction port 41 of the cyclone 40 is changed to circumferentially move in the cylindrical portion 43 , and moves to the conical portion 42 . Also, separation and classification according to the difference of the centrifugal force received depending on the size and the size and the density of the defibrated material are performed. If products included in the defibrated materials are classified into two kinds of the fibers and the ink particles other than the fibers, the fibers are greater than the ink particles or have high density. Therefore, the defibrated materials are separated into the ink particles which are smaller than fibers and have low density and the fibers which are greater than the ink particles and have high density, by the classification process.
The separated ink particles are derived to the upper exhaust port 44 as fine powder together with the air. Also, relatively small ink particles which have low density are discharged from the upper exhaust port 44 of the cyclone 40 . Also, the discharged ink particles are recollected from the upper exhaust port 44 of the cyclone 40 to the receiving unit 45 via a pipe 203 . Meanwhile, the fibers that are greater than ink particles and have high density are transported from the lower output port of the cyclone 40 to the forming unit 70 as the defibrated fibers.
The additive feeding unit 60 that adds additives to the defibrated fiber is provided in the middle of a pipe 204 through which the defibrated fibers are transported from the cyclone 40 to the forming unit 70 . As the additive, for example, a fusion resin, flame retardant, a whiteness improving agent, a paper strengthening agent, or a sizing agent is included. In addition, a portion or all of the additives may be omitted, or another additive may be further inserted. The additive is stored in a storage unit 61 and fed from a feed port 62 by a feeding mechanism (not illustrated).
A sheet is formed by using a mixture in which an additive is mixed with the defibrated fibers. Therefore, a mixture in which a fusion resin or an additive is mixed with the defibrated fibers is called a material fiber.
The forming unit 70 is obtained by depositing the material fibers so as to have an even thickness. The forming unit 70 has a mechanism of evenly dispersing the material fibers in the air and a mechanism of suctioning the material fibers on a mesh belt 73 .
First, as the mechanism of evenly dispersing the material fibers in the air, a forming drum 71 in which material fibers are inserted inside thereof is arranged in the forming unit 70 . The forming drum 71 may evenly mix the additive in the fiber by rotation. A screen with small holes is provided on the surface of the forming drum 71 . The forming drum 71 is rotationally driven, the material fibers pass through the screen with small holes, and thus the material fibers can be evenly dispersed in the air.
Meanwhile, the endless mesh belt 73 in which meshes are formed is disposed vertically downward from the forming drum 71 . The mesh belt 73 is stretched by plural stretching rollers 72 , at least one of the stretching rollers 72 rotates, and thus the mesh belt 73 moves in one direction.
In addition, a suction device 75 that vertically downwardly generates the airflow is provided vertically downward from the forming drum 71 via the mesh belt 73 . The material fibers dispersed in the air can be sucked onto the mesh belt 73 by the suction device 75 .
If the material fibers are introduced into the forming drum 71 of the forming unit 70 , the material fibers pass through the screen with small holes on the surface of the forming drum 71 and are deposited on the mesh belt 73 by the suction force of the suction device 75 . At this point, the mesh belt 73 is caused to move in one direction, and thus the material fibers can be deposited in an even thickness. A deposit including the material fibers deposited in this manner is called a web W. In addition, the mesh belt may be made of metal, a resin, or a nonwoven fabrics, and any products can be used as long as the material fibers can be deposited and the airflow can pass. In addition, if the hole diameter of the mesh is too large, a surface of a sheet at the time of being formed becomes uneven. If the hole diameter of the mesh is too small, it is difficult to stabilize airflow by the suction device 75 . Therefore, it is preferable that the hole diameter of the mesh is appropriately adjusted. The suction device 75 can be formed by forming a closed box in which a window in a desired size is open under the mesh belt 73 , sucking the air in the box from the outside of the window, and causing the inside of the box to have low pressure.
The web W is transported in the web transporting direction illustrated by an arrow in FIG. 2 by moving the mesh belt 73 . The moisture spraying unit 120 sprays and adds moisture to the transported web W. Accordingly, hydrogen bonds between the fibers can be reinforced. Also, the web W to which moisture is sprayed is transported to the pressurizing unit 80 .
The pressurizing unit 80 pressurizes the transported web W. The pressurizing unit 80 includes two pairs of pressurizing rollers 81 . The web W is compressed by causing the web W to which the moisture is sprayed to pass through a portion between the pressurizing rollers 81 facing each other. Also, the compressed web W is transported to the heating and pressurizing unit 90 .
The heating and pressurizing unit 90 heats and pressurizes the transported web W at the same time. The heating and pressurizing unit 90 includes two pairs of heating rollers 91 . The compressed web W is heated and pressurized by causing the compressed web W to pass through a portion between the heating rollers 91 facing each other.
In a state in which contact points between the fibers are increased by the pressurizing rollers 81 causing the distances between the fibers to be short, the fusion resin is melted by the heating rollers 91 , such that the fibers are bound. Accordingly, the strength of the sheets are increased, the excessive moisture is dried, and thus excellent sheets are manufactured. In addition, with respect to the heating, it is preferable that the web W is pressurized and heated at the same time, by installing a heater in the heating rollers 91 . In addition, a guide 108 guiding the web W is arranged under the pressurizing rollers 81 and the heating rollers 91 .
The sheet (the web W) obtained as described above is transported to the cutting unit 100 . The cutting unit 100 includes a cutter 101 that performs cutting in the transporting direction and a cutter 102 that performs cutting in the direction perpendicular to the transporting direction, and cuts the long sheets into a desired size. Cut sheets Pr (the webs W) are stacked on a stacker 160 .
Subsequently, a method for controlling the sheet-manufacturing device is described. Specifically, a controlling method for controlling the suction force of the blower 34 according to the temperature of the acquired defibrating unit 30 is described. FIG. 4 is a flow chart illustrating a method for controlling a sheet-manufacturing device.
First, the temperature of the defibrating unit 30 is acquired. According to the embodiment, respective temperatures measured by the first thermometer 113 , the second thermometer 114 , and the third thermometer 115 , as the temperature acquiring unit 110 are acquired (Step S 1 ).
Subsequently, the mass flow rate of the air including the defibrated material transported from the defibrating unit 30 according to the acquired temperature is controlled.
The control unit decides whether the temperature acquired in Step S 1 is higher than a predetermined temperature (Step S 2 ). If the defibrating unit 30 is continuously driven, the temperature inside thereof gradually increases, and thus the predetermined temperature is set to be the temperature when the defibrating unit 30 is driven for a long time.
If the acquired temperature is not higher than the predetermined temperature (NO in Step S 2 ), the defibrating unit 30 is in a state of being normally driven, and in this case, the blower 34 as the suction unit is controlled in a normal mode and performs suction (Step S 4 ).
Meanwhile, if the acquired temperature is higher than the predetermined temperature (YES in Step S 2 ), the defibrating unit 30 is in a state of being driven for a long time. With respect to the controlling of the blower 34 in this case, the mass flow rate of the air is caused to be great by performing suction by the suction force greater than that in Step S 4 (Step S 3 ).
According to the embodiment, if the acquired temperature is higher than the predetermined temperature, the suction force of the blower 34 is caused to be greater than that in the normal mode. Accordingly, the mass flow rate of the air is caused to be great, such that the transportation properties of the defibrated materials are improved. Also, the generation of the short fiber is suppressed since the excessive defibrated state of the defibrating unit 30 is cancelled.
In addition, according to the embodiment, the temperature is divided according to whether the temperature is higher than the predetermined temperature, but may be divided according to whether the temperature is lower than the predetermined temperature. In addition, plural predetermined temperatures may be prepared, and the temperatures may be divided into three according to the number of the prepared predetermined temperatures. The predetermined temperatures in this case refer to plural temperatures including the temperature when driving is performed for a long time. In addition, the temperature may not be compared with the predetermined temperature, and the acquired temperatures may be compared with each other. In any cases, when the acquired temperature is higher, the mass flow rate becomes greater than that when the acquired temperature is lower, such that the suction force increases.
Hereinafter, according to the embodiment, the following effects can be obtained.
(1) The temperature of the defibrating unit 30 is measured by the temperature acquiring unit 110 , and, for example, if the temperature of the defibrating unit 30 is high, the suction force of the blower 34 as the suction unit increases. Accordingly, the transportation properties of the defibrated material in the defibrating unit 30 are improved, the excessive defibrated state is cancelled, short fibers are scarce, and thus a sheet having the secured strength can be manufactured.
In addition, the invention is not limited to the embodiments described above, and various modifications, improvements, and the like can be added to the embodiments described above. The modification examples are described below.
According to the embodiment, the first thermometer 113 measures the temperature inside the defibrating unit 30 , but the invention is not limited thereto. The invention may be configured such that the temperature of the surface outside the defibrating unit 30 is measured. In addition, the invention may have a configuration in which the second thermometer 114 and the third thermometer 115 measure the temperatures of the surface outside the upstream transporting path 25 and the downstream transporting path 35 in the same manner. Also in this manner, the temperature changes of the respective portions can be easily acquired, such that the same effect can be obtained.
According to the embodiment described above, the first thermometer 113 , the second thermometer 114 , and the third thermometer 115 are provided as the temperature acquiring unit 110 , but the invention is not limited to this configuration. If three thermometers are used, while the temperatures inside the defibrating unit 30 are obtained, the rising state of the temperature of the defibrated materials in the defibrating unit 30 can be obtained by the temperature differences between the upstream and the downstream of the defibrating unit 30 . However, only the temperature in the defibrating unit 30 may be obtained only with the first thermometer 113 . In addition, the temperature difference between the upstream and downstream of the defibrating unit 30 may be obtained by including the second thermometer 114 and the third thermometer 115 only. In addition, only the third thermometer 115 may be included. If two of the second thermometer 114 and the third thermometer 115 are included, or one of the third thermometer 115 is included, since the temperatures of defibrated materials passing through a portion inside the defibrating unit 30 can be estimated, it can be considered that the temperature of the defibrating unit 30 is acquired. In this manner, the cost can be decreased by reducing the number of thermometers.
In addition, a thermometer may be added to the first thermometer 113 , the second thermometer 114 , and the third thermometer 115 . In this manner, more specifically, the temperature of the defibrating unit 30 and the temperature near the defibrating unit 30 can be acquired.
According to the embodiment, the mass flow rate of the air including the defibrated materials transported from the defibrating unit 30 is changed by controlling the blower 34 , but the invention is not limited to this configuration. For example, a wind generating mechanism that generates airflow is arranged in the defibrating unit 30 . Specifically, the defibrating unit 30 includes a rotary blade that rotates, the control unit controls the number of rotations of the rotary blade depending on the acquired temperature. For example, when the acquired temperature is higher than the predetermined temperature, the rotation speed of the rotary blade is caused to be greater than that when the acquired temperature is lower than the predetermined temperature. In this manner, since the mass flow rate of the air increases, the excessive defibrated state is cancelled, and thus an appropriate defibration can be performed. In addition, blades (such as impeller blades) that generate airflow may be provided in addition to the rotary blade so as to rotate together with the blades.
According to the embodiments described above, the mass flow rate of the air including the defibrated materials transported from the defibrating unit 30 is changed by controlling the blower 34 , but the invention is not limited to this configuration. For example, the mass flow rate of the air including the defibrated materials transported from the defibrating unit 30 may be changed by controlling the suction device 75 of the forming unit 70 .
In addition, the introduction force that introduces the air to the defibrating unit 30 may be controlled not by perform suction from the downstream side of the defibrating unit 30 , but by providing an airflow introducing unit on the upstream side of the defibrating unit 30 , so as to control the airflow. In addition, the introduction force may be controlled not by providing the airflow introducing unit, but by introducing exhaust gas from the suction device 75 to the defibrating unit 30 . The same effect can be obtained by causing the introduction force from the airflow introducing unit to be great and causing the suction force by the suction unit to be great.
According to the embodiment, the temperature of the defibrating unit 30 is directly acquired by the first thermometer 113 , but the invention is not limited to this configuration. For example, as illustrated in FIG. 3 , a flow meter 116 that measures the flow rate of the air may be provided in the downstream transporting path 35 , the measurement value of the flow meter 116 is used, such that the temperature in the defibrating unit 30 by calculation or using a data table created in advance may be obtained. If the temperature increase, the mass flow rate decreases and thus the flow rate may be measured without measuring the temperature. Therefore, it can be considered that the flow meter 116 is the temperature acquiring unit 110 . Also in this manner, the effect described above can be obtained.
The “sheet” according to the embodiment mainly refers to a sheet which is made from the raw material comprising fibers such as waste paper or fibers such as pure pulp. However, the invention is not limited thereto, but may be a board shape or a web shape (or shape having unevenness). In addition, as the raw material, a plant fiber such as cellulose, chemical fibers such as polyethylene terephthalate (PET) and polyester, or animal fibers such as wool or silk may be used. The sheet according to the invention can be classified as paper and nonwoven material. The paper includes embodiments in a thin sheet, and includes recording paper for the purpose of writing and printing, wallpaper, wrapping paper, colored paper, Kent paper, or the like. The nonwoven materials are products thicker than paper or products having low strength, and includes typical nonwoven materials, a fiber board, tissue paper, paper towel, a cleaner, a filter, a liquid absorbing material, a sound absorbing body, a buffer material, a mat, and the like.
REFERENCE SIGNS LIST
1 SHEET-MANUFACTURING DEVICE
10 SUPPLYING UNIT
20 CRUSHING UNIT
25 UPSTREAM TRANSPORTING PATH
30 DEFIBRATING UNIT
35 DOWNSTREAM TRANSPORTING PATH
40 CLASSIFYING UNIT (CYCLONE)
45 RECEIVING UNIT
60 ADDITIVE FEEDING UNIT
70 FORMING UNIT
80 PRESSURIZING UNIT
90 HEATING AND PRESSURIZING UNIT
100 CUTTING UNIT
110 TEMPERATURE ACQUIRING UNIT
113 FIRST THERMOMETER
114 SECOND THERMOMETER
115 THIRD THERMOMETER
116 FLOW METER
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A sheet-manufacturing device that manufactures a sheet of which the quality is stable, by controlling airflow to be constant and causing a defibrated state to be constant. A sheet-manufacturing device including a defibrating unit configured to generate a defibrated material by defibrating a defibration object; a temperature acquiring unit configured to acquire a temperature of the defibrating unit; and a control unit configured to change a mass flow rate of the air including the defibrated material transported from the defibrating unit.
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BACKGROUND OF THE INVENTION
The present invention concerns generally a method and an apparatus for controlling automatic doors and, in particular, means for reducing the danger of catching a person in closing automatic doors for elevators.
Elevator safety regulations require safety devices which will prevent elevator users from being caught between closing elevator doors. The problem of providing such safety devices is typically solved by utilizing electomechanical closing force limiters which include a resilient element that is deflected when an impermissibly high force is exerted on the door. Upon deflection, the limiter actuates an electrical contact connected to a door control which initiates a reversing of the door driving motor to open the door.
A solution to the above described problem, in which an impermissible force influence on the door is detected without utilizing an electromechanical system, is shown in the U.S. Pat. No. 4,563,625. A voltage drop proportional to the motor current is interpreted as a torque value by means of a measuring resistor in the motor current circuit and is compared with an adjustable limit value. When the voltage exceeds the limit value, door stopping and reversing operations are initiated.
A substantial disadvantage of the above described solution is that the closing force must never exceed the maximum value which is permitted by the applicable safety regulations. This limitation reduces the accelerating force of the drive unnecessarily and eliminates the possibility of advantageously overloading an electric motor on a short term basis. Furthermore, in the case of a gradual change in the efficiency of the mechanical drive system, the consequence is a faulty response since the voltage drop no longer represents the actual torque and thus a false door fault is indicated.
SUMMARY OF THE INVENTION
The present invention is based on the task of creating a method and an apparatus for providing a door closing force limitation without additional discrete measuring and switching circuits limiting the door closing motor performance. An apparatus for automatically operating the car doors in an elevator system moves the door leaves of a car door by means of a door motor and the door leaves of a shaft door by way of entraining members mounted on the car door leaves. The door leaves are moved between a closed end position and an open end position and the apparatus permits the car door leaves to stop in any position between the end positions, move further in the same direction or reverse.
The apparatus according to the present invention includes a microprocessor control having an input and an output, an electronic switching system having an input connected to the output of the microprocessor control and an output, a direct current motor connected to the output of the electronic switching circuit and mechanically coupled to drive elevator car door leaves and a digital tachometer mechanically coupled to the motor and having an output connected to the input of the microprocessor control for generating an actual speed signal representing the instantaneous speed of the motor to the microprocessor control. The microprocessor control is responsive to the actual speed signal for generating a regulating error difference signal "dV" produced by an external interference force acting upon the car door leaves of the closing elevator door, compares a value of the difference signal "dV" with a value of a predetermined tolerance signal "dVmax" and initiates stopping and reversing of direction of the closing car door leaves when a value of the difference signal "dV" exceeds a value of the predetermined tolerance signal "dVmax".
The advantages achieved by the invention are that the response force of the closing force limitations remains constant and that the protection against being caught is assured to the last millimeter of the closing movement. A further advantage lies in that many different types of presently installed elevator control equipment can be used to implement the method according to the present invention and that the capabilities of the door drive motor can be exploited better. In particular, the present invention can be used advantageously in the case of elevators having a door drive which moves the door leaves of the car door by means of a motor with an intermediate gear coupled to a linear drive and moves the door leaves of a shaft door by way of mechanical coupling members on the car door between closed and open positions and which allows the door leaves to be moved further in the same direction or reversed in every setting between both the "open" and "closed" end positions.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
FIG. 1 is a front elevation of an elevator car automatic door operating apparatus;
FIG. 2 is a schematic block diagram of a control system for the door operating apparatus of FIG. 1 in accordance with the present invention;
FIG. 3 is a schematic block diagram showing the microprocessor control of FIG. 2 in more detail and the connections to the door drive mechanisms;
FIG. 4 is a velocity versus time travel curve for a closing elevator door generated by the microprocessor control shown in FIG. 3;
FIG. 4a is schematic block diagram of the components for generating the travel curve shown in FIG. 4; and
FIG. 5 is a flow diagram of the method of controlling an elevator car automatic door apparatus in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An automatic door operating apparatus 1 for an elevator car is shown in FIG. 1. The apparatus 1 includes drive means mounted on the roof of the car and having a door drive motor 1.1 connected to a door drive control 1.2 and coupled through an intermediate drive belt 1.3 to a linear door drive belt 1.4. A pair of door leaves 1.6 are suspended by door rollers 1.7 and are directed at lower edges by guide members 1.13 for horizontal movement. Abutting vertical edges of the door leaves 1.6 have safety strips 1.11 connected to control plates 1.12. Door clamping members 1.5 secure the door leaves 1.6 to the belt 1.4 and splayable shaft door entraining members 1.10 are mounted on the door leaves 1.6 for engaging the shaft or hositway doors (not shown) at each floor in a conventional manner. A switching cam 1.15 is located at the upper edge of the right-hand door leaf 1.6 for actuating a limit switch 1.9 in the open setting of the door leaves and a limit switch 1.8 in the closed setting of the door leaves.
FIG. 2 is a schematic block diagram of the control system for the door operating apparatus of FIG. 1 showing the functional elements and their relation one to the other on an elevator car 2. The door drive control 1.2 includes a microprocessor control 2.3 connected to generate signals to an electronic switching system 2.4. The door motor 1.1 includes a direct current (DC) motor 2.1 connected to receive operating power from the system 2.4 and a digital tachometer 2.2 connected to the motor 2.1 for generating a signal proportional to the motor speed to the microprocessor 2.3. The drive elements 1.3, 1.4 and 1.5, illustrated in FIG. 1, are combined in a mechanical drive 2.5 coupled between the output of the motor 2.1 and the door leaves 1.6. The shaft door entraining members 1.10, attached to the door leaves 1.6, act on a shaft door 2.8. The functional elements 2.5. 1.6 and 2.8 cooperate with a mechanical latching means 2.6 which actuates latching contacts 2.7. The limit switches 1.8. and 1.9, which are actuated by the car door leaves 1.6 by way of the switching cam 1.15 (FIG. 1), are connected as inputs to a control logic portion, which is not illustrated in FIG. 2, in the microprocessor control 2.3. The control 2.3 and the latching contacts 2.7 generate the appropriate signals to a machine room 2.13 through a suspension cable 2.12. The door safety strips 1.11 and an hall monitor 2.10 respond to changes in conditions at a periphery 2.11 or outside the car and are connected with the microprocessor control 2.3 as well as with the machine room 2.13 in which an elevator control (not shown) is located. The microprocessor control 2.3 is connected through the cable 2.12 to receive control signals from the elevator control in the machine room 2.13. A power supply 2.9 is connected through the cable 2.12 to receive electrical power from the machine room 2.13 and supplies that power to the door drive control 1.2.
FIG. 3 is a schematic block diagram showing the microprocessor control of FIG. 2 in more detail and the connections to the door drive operating apparatus. The large dashed line block 2.3 shows all of the elements of the door motor regulation circuit according to the present invention. A target value generator 3.5 (the smaller dashed block) generates a plurality of travel curves as target speed signals 3.20, 3.21 and 3.22, which curves are stored in memories, and includes a travel curve selector 3.18 which is connected to the memories and is controlled by (dashed line) an elevator control 3.17. A target speed signal "Vref" is generated by the target value generator 3.5 to a first subtractor 3.1, at which an actual speed signal "Vist" is subtracted as generated from the digital tachometer 2.2 connected through a digital filter or digital-to-analog converter 3.15. The signal "Vref" represents the desired speed and the signal "Vist" represents the actual speed for the motor 2.1. The output of the first subtractor 3.1 is connected to an input of a difference value generator (dV) 3.6 which has a first output connected to a limit value comparator 3.7 and a second output connected to a second subtractor 3.2. The limit value comparator 3.7 has a second input connected to receive positive and negative tolerance signals "dVmax" from the target value generator 3.5 and generates appropriate signals to the elevator control 3.17 when the difference signal "dV" exceeds a positive or negative value of the tolerance signal "dVmax".
A learning travel selector 3.19, controlled by the elevator control 3.17, activates a learning travel computer 3.11 which determines values for a mass compensator 3.12 and a friction compensator 3.13. A fourth subtractor 3.4 is connected to receive and add the values from the compensators and the sum is conducted to the second subtractor 3.2 as a compensation signal "Vk". The output of the second subtractor 3.2 is an input to a regulator 3.8 in which the appropriate magnitude is selected for generating the value to the electronic switching system 2.4. A second input to the electronic switching system 2.4 is connected with the lift control 3.17. The direct current motor 2.1 is driven by the electronic switching system 2.4 utilizing the principle of pulse width modulation.
The motor force "Fmot" is an input to a third subtractor 3.3 having an output to a drive load 3.10 the reaction of which generates a drive counterforce "FA" as an input to the subtractor 3.3. An external interference force 3.9 created by an obstruction acts as a negative force "Fw" input to the third subtractor 3.3. The latching elements 2.6 and 2.7 and the limit switches 1.8 and 1.9 are connected between the drive load 3.10 and the elevator control 3.17. The connection of the direct current motor 2.1 with the digital tachometer 2.2 is mechanical. The digital tachometer 2.2 has an output connected to an input of the digital filter 3.15, through the learning travel selector 3.19 to an input of the learning travel computer 3.11, and through an integrator 3.16 to one of the inputs of the target value generator 3.5. An output of the learning travel computer 3.11 is connected to the other input of the target value generator 3.5 to provide a maximum velocity signal "Vmax" and a maximum acceleration signal "Amax".
FIG. 4 shows a velocity "V(m/s)" versus time "T(s)" travel curve for a closing elevator door generated by the microprocessor control shown in FIG. 3. The closing travel curve 3.22 is formed of straight line segments connected by corner or break points a, b, c, d, e and f. A real target curve 4.1 is produced from the closing travel curve 3.22 by filter circuits that round off. A positive tolerance curve 4.3 with a spacing "+dVmax" and a negative tolerance curve 4.2 with a spacing "-dVmax" are generated from the real target curve 4.1.
The curves shown in FIG. 4 represent a process carried out by the components for generating the travel curve shown in the schematic block diagram of FIG. 4a. A filter 3.22.1 rounds off the corners of the closing travel curve 3.22 so that the real target curve 4.1 is generated. The curve 4.1 is present as the target speed signal "Vref" at the output of the target value generator 3.5. The target speed signal is also conducted to a divider 3.22.2 which continuously determines, for example, a five percent component of the instantaneous real target curve 4.1 to obtain the positive tolerance limit value "+dVmax". The negative tolerance limit value "-dVmax" is formed in a following inverter 3.22.3.
FIG. 5 is a flow diagram which illustrates the functions of closing the elevator door. By reference to this diagram and FIG. 3, the mode of operation of the present invention is explained in more detail as follows. With the door open and a travel command being present for the elevator, the travel curve selector 3.18 is controlled by the elevator control 3.17 to select the setting "closing". For example, the control 3.17 can generate a storage address for calling the closing travel curve 3.22 from the memory. The curve is typically filed as a number of straight lines with the corner points a, b, c, d, e and f. These corner points are defined during the first learning travel of the car and lie, for example, at thirty percent for a, at fifty percent for b, at seventy percent for c, at seventy five percent for d, at eighty-five percent for e and at ninety five percent for f of the entire closing travel path of the door.
After the expiration of the time for which the door is held open "DOOR OPEN", and when no obstacle detection signal is present, the release of the door travel "closing" is initiated by a door control logic system 3.14. The target speed signal "Vref" then is generated according to the real target curve 4.1 and applied to the first subtractor 3.1. The actual speed signal "Vist", which originates from the digital tachometer 2.2 and is converted into an analog value in the digital-to-analog converter 3.15, is generated to the first subtractor 3.1. The difference between the input values is then generated as the regulating error or difference signal "dV".
In the limit value comparator 3.7 shown in FIG. 3, the regulating error "dV" is tested for its maintenance of tolerance. In the undisturbed normal case, when "dV" is less than "dVmax", the compensation value "Vk" supplied from the fourth subtractor 3.4 is added to the value "dV" in the second comparator 3.2 and the input signal for the regulator 3.8 is formed. The regulator 3.8 generates the drive signal for the electronic switching system 2.4, which in its turn controls the direct current motor 2.1 by pulse width modulation. The motor force "Fmot" is counteracted by the reaction force "FA" which is caused by the driving load 3.10 and has negative values during acceleration and positive values during deceleration. The third subtractor 3.3 shown in FIG. 3 merely illustrates the force comparison and is not present in the invention. In the normal case, the external interference force 3.9, or "Fw" is not effective. The shape of the real target curve 4.1 is controlled in dependence on the door travel as signalled by the digital tachometer 2.2 through an integrator 3.16 connected to the target value generator 3.5.
The above described undisturbed normal case is represented in FIG. 5 by the decision point 3.7.1 with an exit at "YES". The closing operation continues in a loop through the "NO" exit from a decision point representing the "closed" limit switch 1.8 and back to the input of the decision point 3.7.1. At the conclusion of the closing operation, a "YES" exit from the decision point 1.8 leads to the mechanical and electrical latching at a decision point 2.6 and 2.7 which latching takes place as well as a holding-closed of the closed and latched door with reduced motor force, or by a holding brake not illustrated here. These functions are likewise controlled by the elevator control 3.17 by way of the door control logic system 3.14. A fault signal "SAFETY CIRCUIT OPEN" 3.14.2 is generated from a "NO" exit from the latching decision point in the case of faulty electrical latching and an "ACKNOWLEDGEMENT SIGNAL" 3.14.3 is generated in the normal case from a "YES" exit from the latching elements decision point 2.6 and 2.7 to the elevator control 3.17.
However, the present invention relates to the fault case which is described as follows. The external interference force 3.9 arises when the door moves against an obstacle, wherein it is assumed for this example that the safety strips 1.11 and the hall monitor 2.10 are intentionally or unintentionally ineffective. The description begins at the limit value comparator 3.7 in the flow diagram of FIG. 5, wherein the function is divided into two steps. The limit value being exceeded is ascertained in the first step at the decision point 3.7.1 and the polarity is determined in a second step at a decision point 3.7.2 following a "NO" exit from the first step.
A negative polarity value of "dV" signifies that the value of the actual speed signal "Vist" has fallen below the instantaneous value of the real target curve 4.1, or "Vref", by more than "-dVmax". A positive value signifies that the value of the signal "Vist" has exceeded the instantaneous value of "Vref" by more than "+dVmax". The latter value can, for example, occur in the case of a belt rupture causing the direct current motor 2.1 to suddenly speed up for a short time until the motor speed is regulated which generates such values by way of the digital tachometer 2.2 and the digital filter 3.15. A "FAULT SIGNAL" 3.14.1 is generated as a consequence of a positive polarity value (+) exit from the decision point 3.7.2, whereupon a switching off of the door drive motor takes place by way of the elevator control 3.17 or the door control logic system 3.14. When the closing door is obstructed or braked by an external interference force 3.9, a negative excess arises, "dV" thus being more negative than " -dVmax". In this case, the exit from the decision point 3.7.2 is at the negative polarity value(-) and the direct current motor is braked electrodynamically by the electronic switching system 2.4, and possibly mechanically, to a standstill and a reversing, thus an opening movement, is initiated.
The question must still be answered i this context as to why "-dVmax" is exceeded in the case of a permissible maximum force of one hundred fifty newtons, for example. The motor characteristic and the regulation amplification factor result in a reproducible regulating error "dV" for a certain external interference force 3.9. Both of these factors permit the corresponding positive tolerance curve 4.2 and, above all, the negative tolerance curve 4.3 to be defined. It is demanded that the response values for a stopping and a reversing remain constant. This constant values condition is achieved by the addition of the compensation signal "Vk" in the second subtractor 3.2. The compensation signal "Vk" is redetermined during each learning travel as explained below.
The target value generator 3.5, as initially mentioned, generates a learning travel curve 3.20 which can be called up by the elevator control 3.17 by means of the travel curve selector 3.18. At the same time, the learning travel selector 3.19 is activated and the learning travel is performed as a closing movement at a constant and very low speed. The value over time of the regulating error or difference signal "dV" registered by the learning travel computer provides the indication of the mass to be accelerated in the acceleration phase and the information about the friction conditions over the entire course of travel is provided with the aid of the ascertained regulating error "dV". A mass compensation value is calculated from the first and a friction compensation value is calculated from the second. Both the compensation values added together in the fourth subtractor 3.4 are then input to the second subtractor 3.2 during each normal closing travel of the door. In this manner, slowly changing friction conditions are continuously compensated for and the response value for the closing force limitation is maintained constant.
The very first learning travel typically serves for the travel data detection, whereby the corner points, accelerations and speeds for the travel curves 3.21 and 3.22 are then defined. Learning travels can be performed at desired time intervals according to need. There can, for example, be one learning travel each twenty-four hours or even on each door closure without a travel command for the elevator car.
In the case of excessive or a predetermined worsening of efficiency, no compensation values "Vk" are produced, but a corresponding fault signal is generated instead to the elevator control. For a speedy acceleration and thereby also for a high attainable door speed, in particular for the opening movement, correspondingly high motor currents are required. By reason of the existing thermal inertia of an electrical or direct current motor, such a motor can be loaded for a short time without damage by very high currents which amount to a multiple of the permissible continuous current. The current is limited only by the carbon brushes and the commutator which can, however, be dimensioned appropriately. It is advantageous to provide current limitation in the form of an electronic fuse as protection for the semiconductors in the electronic switching system.
It is furthermore desirable that the protection against being caught in the door remains effective until the end of the closing movement. It is possible with the above described method and apparatus to permit the closing force limitation to function until the last millimeter of the closing movement. This is particularly effective against catching and injuring narrow human limb masses, such as, for example, hands and fingers, and also for articles of clothing. The importance of the protection against being caught in the last phase of the closing movement of the door has a further aspect. As FIG. 1 shows, the elevator door automatic operating apparatus 1 is normally equipped with the safety strips 1.11. However, these strips fulfil their functions only when they are a predetermined distance from the other. When the front edges of the door have approached within five to two centimeters of each other during a closing movement, the detection systems of the safety strips must become less sensitive or even be switched off to prevent self detections.
The present invention fulfills the need for complete protection against being caught in an elevator door up to the last millimeter of door travel. Furthermore, in the end phase of the closing movement, the door speed is so low that the dynamic force components are negligibly small and only the static portion is acting. Thus, the response values of the closing force limitation, for the purpose of still better protection of the elevator users, can be set appreciably below the prescribed maximum value without impairment of the door operations. The method and the apparatus described above can be used for any kind of automatic doors and are not restricted to the field of elevators. For example, entry doors of hotels, commercial and residential buildings, as well as doors of railway and road vehicles can be equipped with the described invention.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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An apparatus and a method for protecting against a person being caught in a closing automatic door provides constant force values up to the few last millimeters of a door closing movement. A regulating error or difference signal representing the difference between the desired door motor speed and the actual motor speed is generated during the door closing travel and is continuously compared with a maximum predetermined tolerance signal produced by a target value generator and a door stop with subsequent reversing is initated if the tolerance value is exceeded. A learning travel computer, during periodic learning travels, determines values for mass compensation and for friction compensation and adds these values to generate a compensation signal which is added to the difference signal as an input to a regulator for controlling the door motor through an electronic switching system. Thus, the response values for stopping and reversing of the door remain constant even though the characteristics of the door operating apparatus may change.
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BACKGROUND OF THE INVENTION
This invention relates to flyer bows. More particularly, this invention relates to a flyer bow construction of airfoil shape whereby higher r.p.m. or lower power draw and a reduced noise level can be realized.
Flyer bows for use on twisting machines are well known in the art. Twisting machines with flyer bows can be used to make twisted cables for a wide variety of uses. Flyer bows, including those of this invention, can be used with pairing, tripling, quadding, bunching and twisting machines for wires.
A typical construction and operation of a twisting machine and flyer bow is disclosed and described in U.S. Pat. No. 3,945,182, the entire contents of which are incorporated herein by reference. As described in U.S. Pat. No. 3,945,182, a typical flyer bow is arcuate along its length and is transversely flat. That is, it is generally rectangular, or at least has opposed flat parallel faces, and it is arcuate along its length. U.S. Pat. No. 3,945,182 discloses the feature of incorporating a groove or recess in the inside surface of the flyer bow and a corresponding ridge or protrusion on the outer surface of the flyer bow. The wires to be twisted nest within the groove to protect the wires from windage that sweeps transversely across the flyer bow as it rotates along its orbital path around a longitudinal axis.
Typical prior art flyer bows have wire guides mounted on the inner surface. These wire guides are typically semicircular in shape and present a flat and blunt exposed air surface. The prior art wire guides are typically secured to the flyer bow by nuts which extend above the top surface of the flyer bow and are exposed to air as the flyer bow rotates. All of this creates drag on the flyer bow as it rotates.
In order to achieve higher productivity from twisting machines with flyer bows, it is desirable to increase the speed of rotation of the flyer bow. However, attempts to do this with prior art machines have encountered the dual problems of motor overload and excessive noise. That is, a twisting machine of a given motor size is intended to operate at a specific maximum operated speed. If an attempt is made to increase the speed of rotation of the flyer bow, the power draw will increase and the motor will overload. Furthermore, even if operation at higher speed is achieved, the noise of the whirling flyer bow at increased speed may become excessive to the point of being an unacceptable employment hazard under applicable governmental regulations.
SUMMARY OF THE INVENTION
The above discussed and/or other problems of the prior art are overcome or alleviated by the present invention. In accordance with the present invention, the flyer bow is configured, in cross section, in the shape of an airfoil. This aerodynamic configuration results in the ability to achieve a higher speed of rotation of the flyer bow without overloading the drive motor. That is, for a given power draw on a motor the aerodynamic flyer bow of the present invention can be operated at a higher r.p.m. than prior art flyer bows. Thus, speed of operation, and hence productivity, can be increased without a corresponding increase in cost. Conversely, the aerodynamic flyer bow of the present invention can be operated at the same rotational speed as a prior art flyer bow with lower power draw, and hence at lower cost, higher efficiency and lower noise levels, than required for prior art flyer bows. This invention also incorporates aerodynamic low profile wire guides on the flyer bow.
The above-discussed and other features and advantages of this invention will be apparent to and understood by those skilled in the art from the following drawings and description.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, wherein like elements and features are numbered alike in the several FIGURES:
FIG. 1 is a side elevation view of the flyer bow of this invention;
FIG. 2 is a cross sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a cross sectional view taken along line 3--3 of FIG. 1; and
FIGS. 4 and 5 are cross sectional views similar to FIG. 1 showing alternative airfoil embodiments for the flyer bow of the present invention.
FIGS. 6A, 6B and 6C show, respectively, side elevation, bottom plan and cross sectional views of the aerodynamic low profile wire guide of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to the embodiment of FIGS. 1-3, a flyer bow 10 has a central portion 12 extending between end mounting portions 14 and 16. The flyer bow is arcuate in shape along its length, and central portion 12 makes up most of the length of the flyer bow, typically about 90% of the length of the flyer bow. By way of example, for a flyer bow of about 60 inches in length, central portion 12 would be about 55 inches long and the end portions 14 and 16 would each be about 3-4 inches long. End portions 14 and 16 are generally rectangular in cross section (see FIG. 3) and constitute mounting elements for securing the ends of the flyer bow to rotors (not shown) on a twisting machine (not shown). If desired, end portions 14 and 16 may contain through holes for the passage of fasteners to mount the flyer bow in rotors. In operation, the flyer bow will rotate about an axis 18. Inner surface 20 of the flyer bow faces toward axis 18 and outer surface 22 faces away from axis 18. As is known to those skilled in the art, the end mounts 14 and 16 can be shaped or fitted for individual machine mounting structures.
Referring now to FIG. 2, an important construction feature of the present invention is shown in that central portion 12 of the flyer bow is formed, in cross section, in the shape of an aerodynamic or airfoil member. More specifically, inner surface 20 is generally flat and outer surface 22 is curved in the form of an airfoil. Inner surface 20 contains a wire receiving groove or recess 26 in which the wires to be twisted are housed to shield the wires from exposure to wind as the flyer bow rotates.
The inner surface 20 of the flyer bow may also include a wear strip 28 which is mounted in a recess 30 in the inner surface 20 of the flyer bow. Wear strip 28 has flat side portions 28a, 28b, and a central portion 28c contoured to match the contour of recess 26. As is apparent from FIG. 2, recess 30 is wider and shallower than wire recess 26 so that recess 30 and wear strip 28 span the width of wire receiving recess 26. Wear strip 28 and recess 30 extend along most of the longitudinal length of center portion 12 of the flyer bow. Wear strip 28 functions to protect the wire bow from abrasion from the wire. As can also be seen from FIG. 2, the location of wear strip 28 in recess 30 results in a continuous and smooth inner surface 20 facing the axis of rotation 18. The incorporation of wear strip 28 in recess 30 also makes it possible to seal the edges of the wear strip with an epoxy or other suitable material to ensure a smooth surface of inner surface 20. While the incorporation of recess, such as recess 26 and a wear strip 28 are known in the art, the feature of incorporating a sealed wear strip 28 in recess 30 is believed to be novel. The sealed edge feature prevents any tendency of the wear strip to lift from wind forces, and it prevents circulation of air under the wear strip, which would increase drag.
The airfoil shape of central portion 12 of the flyer bow is the most important aspect of the present invention. This aerodynamic shape reduces drag on the rotating flyer bow, thus making it possible to achieve the highly desirable result of operating the flyer bow at either a higher speed of rotation, thereby increasing productivity, or operating the flyer bow at a given speed while consuming less power, thereby reducing operating costs. Central portion 12 operates at a much higher speed than end portions 14, 16. As a result, aerodynamic shaping of the flyer bow is important in section 12 to minimize drag, which will, in turn, lower the power required to operate the flyer bow and reduce operating noise.
The flyer bow also has wire guides 32 spaced along the length of inner surface 20 (see FIGS. 1 and 2). Wire guides are known in the art, but the wire guides of this invention are not known in the prior art. Typical prior art wire guides are semicircular in cross section, and they generally have a flat, blunt outer surface, and they are typically secured to the inner surface by nuts mounted on top of the outer surface and which extend above the outer surface. This typical prior art structure, with the blunt surface of the wire guide and the protruding nuts, generates a large amount of detrimental drag.
The prior art wire guide problem is overcome by the wire guide of the present invention. Referring particularly to FIGS. 2 and 6A, 6B, 6C, the wire guide 32 of this invention is a low profile aerodynamic flairing. Wire guide 32 is a low profile arc in shape, and it has flaired elongate front and rear portions 34, 36 which converge to front and rear points, and along its arcuate span it has two inclined sides that meet to form a center line 42. This division into two inclined sides extends to the ends of front and rear portions 34, 36. As a result, as it passes through the air the wire guide presents to the air an aerodynamic split flow path which splits and enhances air flow over the wire guides, thus eliminating much, if not most, of the drag associated with prior art wire guides. Also, as best seen in FIG. 2, wire guide 32 is secured to the wire guide by screws 44 which thread into threaded holes 46 in the bottom of wire guide 32. The heads of screws 44 are housed in recesses 48 in the outer surface 22 of the flyer bow, so the drag associated with the prior art protruding nuts is eliminated. The body of the wire guide may be, e.g., aluminum or plastic, and the wire guide has a wear insert 60, mounted on the inner surface of the wire guide. Insert 60 is preferably of hardened tungsten carbide or a ceramic such as aluminum oxide. Insert 60 is mounted on wire guide 32 by means of a groove 62 on insert 60 which mates with a protrusion 64 on the wire guide. The low profile aerodynamic wire guides significantly reduce drag, noise and power consumption. The low profile aerodynamic wire guides establish an essentially smooth airflow along the entire length (i.e., from front part 34 to rear part 36) of the wire guide. This eliminates the stagnation point and air separation, with attendant drag, associated with prior art semicircular and blunt surface wire guides.
As has been noted previously, a problem encountered in the prior art is that drive motors would be overloaded if it was attempted to operate prior art flyer bows at a higher speed to increase productivity. That problem is overcome with the present invention. By way of example, a prior art twister machine operates at a rated flyer bow speed of 1000 r.p.m. Attempts to increase that speed to e.g., 1400 r.p.m. resulted in increased power draw and overload on the motor driving the flyer bow. However, with the flyer bow of the present invention, the flyer bow was operated at a speed of 1400 r.p.m. at the same power draw required to operate the prior art flyer bow at 1000 r.p.m. Thus, a speed increase of 40% was achieved, with commensurate increase in productivity, with the flyer bow of the present invention without increased power draw and without an increase in operating costs. Conversely, it would be possible to operate the flyer bow of this invention at the speed of the prior art flyer bow, i.e., 1000 r.p.m., but at a lower power draw and a lower operating cost.
A flyer bow rotating at high speeds is subjected to significant load and stress. Therefore, it must have sufficient thickness, i.e., height from the inner surface 20 to the outer surface 22, to impart the desired rigidity to the flyer bow. In accordance with the present invention it is also desired to optimize the airfoil shape to reduce drag on the flyer bow, but without compromising the thickness of the flyer bow above the wire recess 26 while providing sufficient depth of recess 26 to house the wires. Accordingly, as a general rule, the ratio of the width W to the maximum height H of the flyer bow (see FIG. 2) should be in the range of 5:1 to 7:1, and the ratio of the overall height H to the maximum height h of recess 26 should be in the range of 3:1 to 5:1.
It is to be noted that in the embodiment of FIGS. 1-3, rotation of the flyer bow about axis 18 results in the generation of a lift force L in the direction of the arrow shown in FIG. 2. That force tends to hold wear strip 28 in place, but it may also load end portions 14 and 16 in the direction tending to pull them out of their holders in the rotors.
Referring now to FIG. 4 an alternative airfoil embodiment of the flyer bow of the present invention is shown. In the embodiment of FIG. 4, the outer surface 22 is flat and the inner surface 20 is curved in the form of a symmetric airfoil. In this embodiment, the wire recess 26 is located in the inner airfoil surface. In this embodiment, as the flyer bow rotates about its axis 18, the lift L is generated in the direction shown in FIG. 4, which tends to load the end portions 14, 16 in the direction into their respective holders. A wear strip 28 may be incorporated in surface 20 as shown, and wire guide 32 would also be mounted facing the wear strip.
Prior art flyer bows tend to wobble or oscillate, i.e., yaw about axis 18, as they rotate about that axis. The lift generated by the airfoil shaped flyer bows of this invention prevents this wobble or oscillation by imposing a stabilizing force on the bow.
Referring now to FIG. 5, another cross sectional airfoil shaped flyer bow is shown. In this embodiment the airfoil shape is symmetrical about a transverse axis 48, except for the presence of recess 26 and wear strip 28 on inner surface 20. The leading edge 50 of this embodiment has a larger radius than the trailing edge 52, and the trailing edge is narrow or thin. In this embodiment the larger radius leading edge 50 protects the flyer bow against damage or failure from wire strike from broken wires; and the streamlined trailing edge reduces drag and lowers noise.
As with the other flyer bows known in the art, the flyer bow of this invention can be made of various materials. Preferred materials include braided strands of carbon/graphite fiberglass, Kevlar or polyester impregnated with epoxy, polyester resin, vinyl ester or phenolic and molded to form the desired shape.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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A flyer bow is presented for use with twisting machines to twist wires. The flyer bow has inner and outer surfaces, and at least one surface is curved to form an airfoil in cross section. The curved surface may be the outer surface or the inner surface. Both surfaces may be curved to form a symmetric airfoil. The inner surface has a wire receiving recess and a wear strip recess spanning the wire receiving recess. Aerodynamically shaped wire guides may be attached to the inner surface opposite to the wire receiving recess.
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BACKGROUND AND OBJECTS OF THE INVENTION
Camping is becoming a more popular hobby as a greater percentage of the population is concentrated in cities. Many families enjoy weekend outings utilizing a tent for sleeping where they have the opportunity to fully enjoy the out-of-doors. A problem with camping is that of bathing. While some parks have shower facilities, most camping areas of the United States do not have bathing facilities. In addition, many campers prefer areas away from as many of the amenities of civilization as possible, and therefore prefer areas where public bathing facilities are not available.
The present invention is directed towards a lightweight, portable apparatus which can be collapsed into a small volume and which can be used to provide a highly convenient facility for bathing. The invention is particularly directed towards a type of shower including an open top vessel with means for supporting it at an elevated position, such as by ropes which can be attached to a tree limb. The vessels may be filled with water which, if the bather prefers, has previously been heated over a campfire. The bather may then use the portable shower for bathing in complete privacy and comfort, and after use, the device can be easily taken down and collapsed for storage and transportation.
It is therefore an object of this invention to provide an improved portable shower.
More specifically, an object of this invention is to provide a portable shower, including an open top vessel which is of design to receive a quantity of water therein, and including means of attaching a shower curtain around the vessel, means of supporting the vessel in an elevated position such as by attachment to a tree limb, and means for controlling the water discharge from the vessel onto a bather below the vessel.
These general objects as well as other and more specific objects of the invention will be fulfilled in the following description and claims, taken in conjunction with the attached drawings.
DESCRIPTION OF THE VIEWS
FIG. 1 is an elevational external view of an embodiment of the shower of this invention, shown supported to a tree limb.
FIG. 2 is a top plan view taken along the line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2.
FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 1 showing the underneath side of the vessel having the shower curtain attached to the vessel.
FIG. 5 is an enlarged fragmentary cross-sectional view taken along the lines 5--5 of FIG. 4 showing how the shower curtain is attached to the vessel.
FIG. 6 is a fragmentary cross-sectional view taken along the line 6--6 of FIG. 2 showing the details of the valve used to control water flow from the vessel. FIG. 7 is a cross-sectional view of the shower bottom showing one means of attaching the shower curtain to it.
FIG. 8 is a fragmentary cross-sectional view of a portion of the shower bottom showing the manner of attachment to the lower edge of the shower curtain.
SUMMARY OF THE INVENTION
A portable shower is provided including an open top vessel having a circumferential periphery which defines an area of sufficient size to accommodate a bather thereunder. In the illustrated arrangement, the vessel is circular and of about 24" in diameter, although a slightly smaller or larger size is satisfactory to provide a comfortable area for a bather. The vessel has an opening in the bottom, closed by a valve, actuatable from underneath the vessel. The vessel has ropes extending upwardly therefrom so that it may be attached to the limb of a tree and as so attached, can receive water therein deposited such as from a bucket, to fill the vessel sufficient to provide water for a shower. A shower curtain is provided having the top edge affixed to the periphery of the vessel. A shower bottom in the form of a relatively flat shallow depth saucer-like element is provided on which the bather stands during a shower and includes means of attaching the lower edge of the shower curtain to the shower bottom. The complete device may be collapsed so that the total thickness is substantially that of the height of the open top vessel for ease of storage and transportation.
DETAILED DESCRIPTION
Referring to the drawings and first to FIG. 1, an elevational view is shown of one embodiment of the portable shower of this invention. The portable shower includes an open top vessel 10, a shower curtain 12, and a shower bottom 14. The shower is supported by ropes 16 which may be tied to any elevated structure for support, such as a tree limb 18. The shower bottom 14 rests on the earth's surface 20 with the height of the vessel 10 being adjustable by the length of rope 16 so that shower curtain 12 is held more or less upright, as shown, although some slack can be employed in the shower curtain to make up for adjusting the elevation of the vessel 10 above the shower bottom 14.
Referring to FIGS. 2 and 3, the details of the vessel 10 are better shown. The vessel 10 is preferably formed of molded plastic and is open top so that water can be easily poured into it. The vessel wall is of inverted V configuration, with exterior walls 22 and interior wall 24 which receives water 26. The outer wall 22 is upturned at the lower edge 22A to provide structural rigidity. The outer wall 22 includes integral flat areas or notches 28 where means are provided for supporting the shower curtain. FIG. 5 is an enlarged cross-sectional view showing one way of supporting the shower curtain. The curtain 12 has an upper edge 30 which is formed about a circular rod 32 of metal or plastic. The rod is configured to fit against the interior surface of outer wall 22 and against notches 28 and is held in place by a plurality of straps 34 which extend through openings 36. Straps 34 may be a length of twine or small diameter rope which is tied in a knot or, as illustrated, a commercially available flat plastic strip having a self-locking outer end 34A.
Referring again to FIGS. 2 and 3, the ropes 16 by which the vessel 10 is supported consists of three or more portions which extend through openings 38 in the inverted V notch of the vessel. The lower end of each of the segments of rope 16 is tied in a knot 40, and each length of rope extends up to a center point (See FIG. 1) so that the vessel 10 is held horizontally for deposit of water therein.
The vessel interior wall 24 includes bottom 42 having an opening 44 (See FIGS. 2 and 3). A valve structure generally indicated by numeral 46 is provided to control the flow of water from the vessel and is operable from the lower surface of the vessel so that a bather may initiate or terminate the flow of water.
As shown in the enlarged partial cross-sectional view of FIG. 6, the vessel bottom 12 has a recessed area 48 which includes the opening 44, and surrounding that major opening, a plurality of small diameter openings 50 through which water flows when the valve is opened.
Positioned in opening 54 is an externally threaded member 52 which itself has an opening 54 receiving a shaft 56. Below the vessel bottom 42 is an internally threaded member 58 having opening 60 slidably receiving shaft 56. The externally threaded member 52 and internally threaded member 58 cooperate to close opening 44 and at the same time to receive a washer 62 therebetween which surrounds and seals the shaft 56. Thus, shaft 56 is free to be moved up and down by a bather standing beneath the vessel but water is discharged only through small diameter openings 50.
At the upper end of shaft 56 is a large diameter flexible diaphragm 64. It is attached at its center to the shaft by means of a nut 66 and small diameter washer 68 which are received about the reduced diameter threaded upper end 56A of the shaft. A lower larger diameter washer 70 supports diaphragm 64.
When the shaft 56 is pushed upwardly, water is free to flow from the interior of the vessel through small diameter openings 50. The shaft is pulled downwardly, as illustrated in dotted outline. The flexible diaphragm 56 seals against the interior of vessel bottom 42 to maintain water in the vessel. In this manner an inexpensive valve arrangement is provided completely controllable by a bather from underneath the vessel to regulate the flow of water from the vessel.
Referring to FIGS. 7 and 8, the shower bottom 14 is a shallow depth flat, saucer-shaped member preferably formed of plastic. It includes an outer circumferential recess 72 which receives the lower edge 12B of the shower curtain and a circular rod 74. A plurality of straps 34 are positioned around rod 74 and extend through openings 76. Straps 34 may be the same type illustrated and described for holding the upper end of the shower curtain.
OPERATION
When a bather desires to employ the apparatus of this invention for a shower, a tree limb or other elevated structure is located of approximately the height to 9' above the ground. By use of rope 16 the vessel 10 is supported in such a way that the shower curtain 12 hangs down and the shower bottom 14 is supported on the earth without applying stretching force on the shower curtain 12. Water is then poured in the top of the vessel with valve 46 in a closed or downward position. If the bather desires, the water can be warmed over a campfire. With the water in the vessel 10, the bather can enter the shower by separating the overlapped vertical edges 12C and 12D of the shower curtain and step onto the shower bottom 14. A short loop of rope 78 (FIG. 1) extending from vessel 10 may be used for hanging clothing and a towel outside the shower. The bather then pushes up on shaft 56, admitting water downwardly into the shower. When the shower is completed, the shaft 56 may be pulled back down to conserve water remaining in vessel 10.
Water falling down over the person taking the shower falls upon the shower bottom 14, which is not intended to be of a size to collect water of the shower but to permit the water to overflow--the function of the shower bottom 14 being to hold the shower curtain 12 in place and permit the bather to stand on a clear surface and not on the earth.
When the portable shower is to be removed, all that is necessary is that the rope 18 be taken from around the tree limb or other vertical support 18. The shower will then collapse so that all of the shower curtain 12 is packed within the inverted recess between walls 22 and 24 and the shower bottom 14 is positioned contiguous to the vessel bottom 12 providing a package of short total vertical height. Thus, the portable shower is very compact when arranged for travelling, but requires no assembly or disassembly in any way when it is put in use or removed from use.
All of the materials of which the parts of the shower of this invention are constructed can be of the non-corrosive, non-rusting and mildew-resistant type, such as various types of plastics.
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 embodiments set forth herein for purposes of exemplification, 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.
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A portable shower including an open top vessel having a circumferential periphery defining an area of sufficient size to accommodate a bather thereunder, the vessel having an opening and means from underneath the vessel for controlling flow of water through the opening, a shower curtain having the upper edge secured to the periphery of the vessel, and a shower bottom in the shape of a shallow flat dish having means at the periphery for attachment to the lower edge of the shower curtain so that water placed in the vessel may be discharged onto a bather concealed by the shower curtain.
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BACKGROUND OF THE INVENTION
This invention relates to a safety system for the openable doors, lids, panels and the like forming part of protective housings, particularly for textile machines such as cards, bale openers, cleaners, fine openers and the like. The machines have movable and/or moving components such as rotary shafts, cylinders and the like operated by machine drives. When the openable housing component (hereafter door) is opened, the system emits an electric signal for stopping the machine drive.
For safety reasons, when a door of the textile machines is opened, the current supply to the drive of the machine has to be interrupted and, significantly, as long as the door remains open, the drive should not be able to be restarted. For this purpose, switching components which are coupled with the door,operate safety limit switches which interrupt the current supply. Such limit switches have to be electrically wired and installed at substantial structural expense.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a safety system which is inexpensive, which is easy to install and which has a simple structure.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the housing door is associated with at least one pneumatic pressure difference generator which is coupled with an air line containing, as a signal transmitter, an electro-pneumatic pressure-responsive switch.
Basically, the invention provides a pneumatic-electric safety system in which, in the immediate vicinity of the door, an air line is provided. With each door there is associated a pressure difference generator coupled to the air line. Further, the air line contains an electro-pneumatic pressure-responsive switch (hereafter pressure switch) which, upon pressure alterations in the air line, emits an electric signal. Thus, an important aspect of the system is the appearance of a pressure difference, that is, a transition from a higher pressure to a lower pressure or conversely. If, for example, a door of the machine housing is opened, the associated pressure difference generator effects a change in the pressure prevailing in the air line. This pressure change causes the pressure switch to present an output indication resulting in a shutoff of the machine drive which will immediately come to a standstill if no large masses are being moved. The system according to the invention is of simple construction and has no limit switches. As concerns manufacturing technology, the system has the particular advantage that a usually already-existing air line--by means of which, for example, pipe switches in pneumatic tube dispatchers are operated--can be used and thus a wiring and installation of a limit switch may be dispensed with. It is a further particular advantage of the system according to the invention that it operates with superior reliability. Not only upon opening of a door but also in case of other pressure changes caused, for example, when damages or leaks in the air line or the pressure difference generator occur, a shutoff of the machine drive will immediately result.
According to a preferred embodiment of the invention the air line forms part of a closed system; it thus operates without an additional external air source. The pressure difference generator which is coupled to the air line comprises, as a contact element, a compressible component, which is made, for example, of rubber and which cooperates with a door. As long as the door is closed, the rubber member is compressed and when the door is opened, the rubber member expands, resulting in an expansion of the air in the line. This leads to a pressure difference which is applied to the pressure switch contained in the air line. The pressure switch emits an electric signal by means of which the machine drive is turned off. It is, however, feasible to so arrange the system that the rubber member is in a relaxed, expanded state when the machine door is closed and upon opening of the door the rubber member is compressed, causing an electric signal to be emitted by the pressure switch.
According to another embodiment of the invention, the air line is coupled to an external air pressure source which may be part of an already-existing pressurized air system. In the air line there prevails, for example, a pressure which is higher than the ambient pressure externally of the air line. Preferably, the pressure difference generator comprises a closure element which is associated with a nipple of the air line and which is mounted on the machine door. Thus, in such a case the pressure difference generator is a separable two-part component. Expediently, between the nipple and the closure element a rubber seal is provided. If the door is opened, the closure element moves away from the nipple (or a valve plunger opens a valve) thereby opening the air line. As a result, the pressure in the air line drops, for example, to the ambient surrounding pressure. The thus-obtained pressure difference affects the pressure switch which emits an electric signal to shut off the machine drive. Preferably, between the air pressure source and the air line there is arranged a solenoid valve which is expediently actuated by a push button arranged in a central control panel. According to one preferred embodiment of the invention, the solenoid valve is opened to permit the pressurized air to flow into the air line. As soon as the air line is filled with pressurized air, the pressure switch generates a signal which causes a circuit breaker in the machine drive circuit to be closed and which, at the same time, shuts off the solenoid valve. According to another preferred embodiment, the solenoid valve, after all the doors are closed, opens and remains open even after the air line has been filled with pressurized air. Upon pressure drop in the air line which occurs, for example, when one of the doors is opened or a leakage in the air line occurs, the solenoid valve is closed upon command of a signal emitted by the pressure switch so that no further pressurized air is supplied. In this manner unnecessary air consumption is avoided. The opening and closing of the solenoid valve may be effected automatically.
It is an important aspect of the safety system that the machine cannot be operated as long as the door is in an open state (prevention of circuit closing). Preferably, the air line forms a closed circuit. The invention may be used in connection with components of a larger system or several systems may be provided with a sole safety circuit according to the invention. Preferably, the safety system according to the invention is driven with a low air pressure which is maintained within the system at an as constant a level as possible.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic plan view of a textile machine incorporating a safety system according to the invention.
FIGS. 2a and 2b are schematic sectional views of a preferred embodiment of the invention shown in an inoperative and operative state, respectively.
FIGS. 3a and 3b are sectional views of a component of the preferred embodiment in the inoperative and operative state, respectively.
FIGS. 4a and 4b are schematic sectional views of a further preferred embodiment of the invention shown in an inoperative and operative state, respectively.
FIG. 5 is a diagram of a circuit for a system according to the invention for supplying air solely for pressure build-up.
FIG. 6 is a diagram of a circuit for a system according to the invention for the continuous supply of pressurized air.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1, there is illustrated a textile machine 1 which is, for example, a pneumatic fiber tuft feeder. The textile machine 1 has a sheet metal housing 11 comprising a plurality of doors 2 which for safety reasons prevent access to rotating shafts, cylinders and the like. In the immediate vicinity of the doors 2 there extends an air line 3 which is adapted to carry pressurized air in a closed loop. At the individual doors 2 small circles in the drawing indicate the location where a pneumatic pressure difference generator 4 is mounted. The air line 3 includes an electro-pneumatic pressure switch 5 which is connected with a circuit breaker relay 6. The relay 6 is a component of an electric circuit which further has a voltage source 7, a motor 8 constituting the drive for the textile machine 1 and a main motor switch 9.
Turning now to FIGS. 2a and 2b, with the inner face of each door 2 there cooperates a separate pressure difference generator 4 comprising, as a contact element, a hollow compressible rubber member 41. The pneumatically operated pressure switch 5 has an inner space which is divided into two chambers 53 and 54 by means of a resilient (rubber) diaphragm 52. Approximately in the middle of the diaphragm 52 there is provided a metal contact plate 55 which is electrically connected with the relay 6. In a wall of the chamber 54 there is mounted a contact pin 56 which cooperates with the contact plate 55 and which is electrically connected with the relay 6. The pressure difference generators 4 communicate with a common closed (sealed) air line 3 which, by means of a conduit 51 communicates with the chamber 53 of the pressure switch 5. The chamber 54 of the pressure switch 5 has an air release nipple 57 for pressure equalization. The relay 6 is connected in a first circuit a which has a control voltage source 10 and a circuit breaker 12. The relay 6 operates a circuit breaker 6a of a second circuit b in which the machine drive motor 8, the drive voltage source 7 and the motor switch 9 are connected.
FIG. 2a shows the safety system in an inoperative state, that is, the doors 2 are closed and the relay 6 maintains the circuit b closed, whereby the motor 8 may be operated by the switch 9. By virtue of the closed position of the doors 2 the respective compressible members 41 of the pressure difference generators 4 are in a compressed condition, so that from the air line 3 pressurized system air is communicated to the chamber 53 of the pressure switch 5. As a result, the diaphragm 52 is deformed towards the contact pin 56, whereby the contact plate 55 mounted on the diaphragm 52 is in an electric contact with the contact pin 56. By closing the circuit breaker 12, the first circuit a is closed, whereby the relay 6 is energized, maintaining the circuit breaker 6a closed, so that the motor 8 may be operated.
FIG. 2b shows the doors 2 open. The compressible rubber members 41 of the pressure difference generators 4 expand as the doors 2 are opened, causing an expansion (pressure drop) of the air in the air line 3. As a result, the pressure in the chamber 53 drops and the diaphragm 52 moves towards the right by virtue of its own resiliency from its position shown in FIG. 2a into its new position shown in FIG. 2b, whereby the contact plate 55 moves away from the contact pin 56. As a result, the circuit a is interrupted, thereby deenergizing the relay 6 which in turn opens the circuit b thus shutting off the motor 8. It is to be understood that the same sequence of events takes place even if only a single door 2 is opened.
Turning now to a variant shown in FIGS. 3a and 3b, the compressible member 41 of the pressure difference generator 4 cooperates with the outer face of the door 2. While in the closed position of the door 2 the compressible member is in a relaxed, expanded state (FIG. 3a), the compressible member 41 is pressed together when the door is opened (FIG. 3b). The air pressure increase and decrease with the corresponding signal transmission is thus reversed as compared to the operation described in connection with FIGS. 2a and 2b and the cooperating parts of the pressure switch 5 may be reversed accordingly to effect signalling when a door 2 is opened.
Turning now to FIGS. 4a and 4b, at the inner side of the door 2, on an end opposite a door hinge 21, there is arranged a two-part pressure difference generator 4a which is formed of a coupling nipple 42 mounted on the air line 3 and a closure element 43 mounted on the door 2. A rubber seal 44 is arranged between the components 42 and 43. With the air line 3 there is coupled, by means of an air nipple 131, a solenoid valve 13 known by itself. The air line 3 is connected with an electro-pneumatic pressure switch 5a which may be an electronic proximity switch operating without mechanical contacting. The switch 5a may be of the type described, for example, in German Patent No. 2,711,346 to which corresponds U.S. Pat. No. 4,211,935. The pressure switch 5a is connected in the circuit a, similarly to the embodiment described in connection with FIGS. 2a and 2b. In the circuit a there are further connected the solenoid valve 13 and a push button switch 14. The relay 6 opens or closes the circuit b which contains the circuit breaker 6a, the drive voltage source 7, the motor 8 and the motor switch 9.
FIG. 4a shows the safety system with the door 2 and the circuit breaker 12 closed. By operating the push button 14, the solenoid valve 13 is opened so that pressurized air may be introduced through the pressurized air nipple 131 into the air line 3 in the direction of the arrow. The pressure difference generator 4a responds and the pressure switch 5a emits an electric signal, whereupon the relay 6 is energized, for example, with the intermediary of a protective circuit breaker (not shown), whereby the circuit breaker 6a is closed, thus permitting the motor 8 to be energized. Thereupon the push button 14 may be again operated to close the solenoid valve 13, whereby the pressurized air supply is shut off.
If, as shown in FIG. 4b, the door 2 is opened, by means of the separation of the closure element 43 from the coupling nipple 42, the air line 3 is opened (interrupted) so that the pressure in the air line 3 drops to ambient air pressure. This causes the pressure switch 5a to open (that is, the pressure switch 5a stops transmitting signals), resulting in an opening of the circuit a. Thus, the relay 6 is deenergized, the circuit breaker 6a opens the circuit b, whereby supply of current to the motor 8 is prevented.
FIG. 5 shows a circuit for a system which is described in connection with FIGS. 4a and 4b and in which pressurized air is introduced into the air line 3 only for building up the air pressure in the safety system. Lines R o T o supply voltage to the circuit. A signalling lamp 15 indicates when the pressure in the air line 3 has reached a value such that the pressure switch 5a starts emitting electric signals. The machine may be started by closing the switch 12 of the motor 8.
Turning now to FIG. 6, there is shown a circuit for a system in which pressurized air is continuously introduced through the coupling nipple 131 into the air line 3. The solenoid valve 13, upon pressure drop in the air line 3, closes the coupling nipple 131 and thus interrupts air supply. For this purpose, the switch 12 is associated with a holding relay 16 which maintains the solenoid valve 13 energized.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A safety system operatively connected with a door, includes an air line, a pressure difference generator communicating with the air line and operatively connected with the door for altering the pressure of air in the air line when the door moves from a closed position to an open position and a pressure-responsive switch operatively connected with the air line for presenting an output indication in response to the alteration of air pressure in the air line.
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FIELD OF THE INVENTION
[0001] The invention relates to an address generation unit for a processor.
BACKGROUND OF THE INVENTION
[0002] In signal processing a high percentage of the algorithms use loops, usually with high iteration counts and consisting of relatively few instructions and/or operating on relatively few data, such as a line of pixel blocks. To improve the speed of processing, DSPs have been equipped with so-called address generation units (AGUs). These units generate from a current address the next address. Some units support several addressing modes. The units calculate the addresses using a number of registers, depending on the addressing mode. Address generation units are known for generating data addresses (sometimes also referred to as address computation units (ACUs)) as well as for generating instruction addresses (sometimes also referred to as loop control units).
[0003] WO 01/04765 describes a VLIW processor for signal processing. The processor includes four the same processing elements, each with a number of functional units. Each of the processing elements includes as a functional unit an address generation unit (AGU). The AGU supports seven addressing modes, being direct addressing, base plus offset addressing, indirect/indexed addressing, base plus index addressing, circular indexed addressing and processing element relative addressing. For each of the addressing modes registers are used to calculate the addresses. For details on the addressing modes, the algorithms for calculating the next address, the registers used by the algorithm and exemplary hardware implementations, the reader is referred to WO 01/04765. The VLIW instruction includes an instruction slot for each of the processing elements. The addressing mode is indicated as part of the instruction. The registers are part of the processor's context and can be loaded, saved, and restored as other registers that are part of the context. The VLIW processor is used in combination with a wide memory for storing the VLIWs. Each memory line stores one VLIW instruction. The memory is accessed for each instruction fetched and fed directly to the decode logic to control the execution of multiple execution units in parallel.
[0004] The processing elements of the known VLIW processor are single instruction multiple data stream (SIMD) processors, also known as vector processors. A VLIW vector processor potentially has a very high performance for signal processing. Signal processing tasks that would require such a performance, like a software modem for 3G mobile communication standards, are usually composed of many sub-tasks that can be vectorized. The vector processing does result in such sub-tasks being completed relatively fast. Completed in this context also covers the situation wherein al block of data has been processed and processing will be resumed at a later moment for a new data block (usually in fixed cycles). Consequently, switching between sub-tasks also occurs relatively frequently. A context switch requires that the current registers of one or more ACUs that are used for the currently halted task are saved and the saved registers for the newly activated or re-activated task are loaded into the relevant registers of the involved ACUs. For each ACU, for example, four registers may be involved. For one ACU the context switch may thus include saving/restoring a total of 8 registers.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to provide a processor architecture that is better suitable for high-performance tasks, in particular signal processing for mobile communication systems. It is a further object to provide such architecture for vector processors.
[0006] To meet the object, the processor includes: a memory port for accessing a physical memory under control of an address; at least one processing unit for executing instructions stored in the memory and/or operating on data stored in the memory; an address generation unit (hereinafter “AGU”) for generating an address for controlling access to the memory, the AGU being associated with a plurality of N registers enabling the AGU to generate the address under control of an address generation mechanism; and a memory unit operative to save/load k of the N registers, where 2<=k<=N, triggered by one operation, where the memory unit includes a concatenator for concatenating the k registers to one memory word to be written to the memory through the memory port and a splitter for separating a word read from the memory through the memory port into the k registers.
[0007] The inventors have realized that as the performance of the processors increases the time spent on configuration of the registers of the AGUs increasingly becomes bottle-neck. In the conventional processor architectures only one register can be saved or restored in a memory cycle, resulting in much time being wasted waiting for the AGUs to be initialized (configured) with the correct data To overcome this, at least two of the registers can be saved triggered by one operation, such as a context switch or explicit instruction to save or restore some or all of the AGU registers. To this end, the memory unit of the processor includes a concatenator and splitter for mapping a plurality of the AGU registers to one memory word. The AGU and memory unit according to the invention can in principle be used in any processor, such as a DSP. Advantageously, the AGU and memory unit are used in a vector processor. So far, vector processors have not been used widely for signal processing. This is partly caused by the fact that the conventional vector processor architecture is ineffective for applications that are not 100% vectorizable, due to the implications of what is known as “Amdahl's Law”. This law states that the overall speedup obtained from vectorization on a vector processor with P processing elements, as a function of the fraction of code that can be vectorized (f), equals (1−f+f/P) −1 . This means that when 50% of the code can be vectorized, an overall speedup of less than 2 is realized (instead of the theoretical maximum speedup of 32). This is because the remaining 50% of the code cannot be vectorized, and thus no speedup is achieved for this part of the code. Even if 90% of the code can be vectorized, the speedup is still less than a factor of 8. For use in consumer electronics applications, in particular mobile communication, the additional costs of a vector processor can only be justified if a significant speed-up can be achieved. The AGU and memory unit according to the invention assist in breaking through Amdahl's law by providing optimal support for processing of the data and/or instruction loops and efficiently handling jumps and context switches.
[0008] As described in the dependent claim 2 , the memory unit is operative to perform the saving/loading in one read/write cycle of the physical memory. In this way, the AGU configuration can take place fast. Preferably, all AGU registers are saved/loaded in one operation as described in the dependent claim 3 .
[0009] As described in the dependent claim 4 , the processor has several sets of registers, where each set enables an AGU to generate an address. With the increased performance, the processor can perform more tasks in parallel and thus can benefit from using more than one set of registers. For efficient processing of data or instruction loops a set of registers per loop may be used. To speed up configuration of the plurality of sets, registers of more than one set can be saved in one operation by concatenating the registers of several sets to one memory word. As described in the dependent claim 5 , the processor may have several AGUs, each with an own set of registers. The different AGUs may be functionally the same (and thus have the same number of registers). If so desired, different AGUs may be assigned to different address calculation schemes and, consequently, may have different numbers of registers. Preferably, all registers of at least two AGUs can be saved/loaded in one operation using one memory word. Alternatively, as described in the dependent claim 6 , an AGU may also be associated with more than one set of registers, where each set enables the generation of an address. In this case, the AGU can be selectively connected to a set to perform a new address calculation. Preferably, all registers of at least two sets of registers can be saved in one memory word.
[0010] As described in the dependent claim 8 , advantageously the sets of registers that need to be configured can be selected. In this way, AGUs and/or sets of registers can optimally be allocated to tasks where, in response to a context switch involving the task, the involved AGUs and/or sets of registers can be easily selected and reconfiguration be achieved. To simplify the selection, AGUs and/or the sets of registers may be grouped in separately selectable groups. The groups can then be assigned freely to tasks. Reconfiguration stakes place for at least one group at a time.
[0011] As defined in the dependent claim 9 , the width of the memory word is a multiple of the smallest word on which the processor can operate. The registers are stored in the memory on processor word boundaries. In this way the register values can be changed easily without requiring additional instructions to set the AGU registers
[0012] As described in the dependent claim 8 , preferably the processor can operate on a plurality of M data elements in parallel (for example, the processor is an SIMD/vector processor) and the memory is wide to be able to store all M data elements in one memory word. In this way, many registers of AGUs can be saved/loaded in one operation.
[0013] These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the drawings:
[0015] FIG. 1 shows a preferred configuration in which the scalar/vector processor according to the invention may be used;
[0016] FIG. 2 shows the main structure of the scalar/vector processor according to the invention;
[0017] FIG. 3 shows supported data widths and data types;
[0018] FIG. 4 shows a block diagram of the vector-memory unit;
[0019] FIG. 5 illustrates mapping two sets of ACU registers to one vector register,
[0020] FIG. 6 shows a fixed relationship between a set of ACU registers and an ACU; and
[0021] FIG. 7 shows a configurable relationship between the sets and the ACUs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The address generation unit (AGU) and memory unit are preferably used in a processor optimized for signal processing. Such a processor may be a DSP or any other suitable processor/micro-controller. The remainder of the description describes using the units in a highly powerful scalar/vector processor. Such a processor may be used stand-alone or in combination with another processor. FIG. 1 shows a preferred configuration in which the scalar/vector processor may be used. In this configuration, three main components are connected via a bus 110 . The bus 110 connecting these three components may be any suitable bus, for example an AMBA High-speed Bus (AHB). The main components are:
the programmable scalar/vector processor 120 comprising functional units and a local data memory (referred to as vector memory in FIG. 1 ), a micro-controller or DSP subsystem 130 , including limited on-chip program and data memory; an interface block 140 .
[0025] The scalar/vector processor 120 is mainly used for regular, “heavy/duty” processing, in particular the processing of inner-loops. The scalar/vector processor includes vector processing functionality. As such, it provides large-scale parallelism for the vectorizable part of the code to be executed. The vast majority of all signal processing will be executed by the vector section of the scalar/vector processor. With an array of, for example, 32 identical processing elements executing the same instruction, it offers massive parallelism. Combined with a 32-word wide memory interface this leads to unprecedented programmable performance levels at low cost and moderate power-consumption. However, fully exploiting this parallelism is not always feasible, as many algorithms do not exhibit sufficient data parallelism of the right form. According to Amdahl's law, after vectorization of the directly vectorizable part of the code, most time is spent on the remaining code. The remaining code can be split into four categories:
address related instructions (e.g. incrementing a pointer into a circular buffer, using modulo addressing) regular-scalar operations (i.e. scalar operation that correspond to the main loop of the vector processor) looping irregular scalar operations
[0030] The fractions of code for each of these categories is highly dependent on the algorithm executed. For example, the Golay correlator (used for P-SCH searching) requires a lot of address related instructions, but this is not the case for other algorithms such as the Rake. The performance of address related instructions and looping can be optimized by using the AGU/memory unit according to the invention. The operation of the regular scalar operation scan be optimized by tightly integrating scalar and vector processing in one processor. Study of all the algorithms relevant for 3G modems by the inventors has revealed that the fraction of irregular scalar operations is very limited. This property allows the separation of tasks between the scalar/vector processor 120 and the micro-controller or DSP 130 where the separate micro-controller or DSP 130 performs the irregular tasks and, preferably, controls the scalar/vector processor as well. In this preferred configuration, the scalar/vector processor 120 acts as a programmable, co-processor (in the remainder also referred to as CVP, Co-Vector Processor). The interface between the scalar/vector processor 120 and the micro-controller 130 deals with communication (e.g. through shared memory) and synchronization (e.g. through shared memory and status signals). The interface is preferably memory-mapped.
[0031] The interface block 140 allows the processors to interact with the remainder of the system. In the preferred embodiment, the scalar/vector processor is used as a software modem (transceiver) for 2G/3G mobile networks. For such a software modem function, the interface block 140 may include dedicated hardware as a front-end with as a main task to pass control and data words to the vector memory, for example DMA, under control of the micro-controller 130 . The data in the vector memory is then processed by the scalar/vector processor.
[0032] The scalar/vector processor 120 may be a slave to the bus 110 , whereas the micro-controller 130 and the interface block 140 (which may include a DMA unit) may act as a master. All the communication with the CVP, be it program, data, or control, is preferably memory mapped. The memory may be an off-chip DRAM, and this DRAM may also be used as (de-) interleaving memory by the scalar/vector processor.
[0033] In the description the phrase “address calculation unit” or ACU is mainly used. For the purpose of the description this is considered to be the same as “address generation unit” or AGU. The description focuses on using such units for calculating data addresses. Persons skilled in the art will be able to use the same functionality also for calculating instruction addresses (“loop control”).
[0034] FIG. 2 shows the main structure of the processor according to the invention. The processor includes a pipelined vector processing section 210 . To support the operation of the vector section, the scalar/vector processor includes a scalar processing section 220 arranged to operate in parallel to the vector section. Preferably, the scalar processing section is also pipelined. To support the operation of the vector section, at least one functional unit of the vector section also provides the functionality of the corresponding part of the scalar section. For example, the vector section of a shift functional unit may functionally shift a vector, where a scalar component is supplied by (or delivered to) the scalar section of the shift functional unit. As such, the shift functional unit covers both the vector and the scalar section. Therefore, at least some functional units not only have a vector section but also a scalar section, where the vector section and scalar section can co-operate by exchanging scalar data. The vector section of a functional unit provides the raw processing power, where the corresponding scalar section (i.e. the scalar section of the same functional unit) supports the operation of the vector section by supplying and/or consuming scalar data. The vector data for the vector sections are supplied via a vector pipeline.
[0035] In the preferred embodiment of FIG. 2 , the scalar/vector processor includes the following seven specialized functional units.
[0036] Instruction Distribution Unit (IDU 250 ). The IDU contains the program memory 252 , reads successive VLIW instructions and distributes the 7 segments of each instruction to the 7 functional units. Preferably, it contains a loop unit that supports up to three nested levels of zero-overhead looping. In the preferred embodiment, it does not support branches, jumps, or interrupts. The initial program counter is loaded from the stint descriptor, described in more detail below.
[0037] Vector Memory Unit (VMU 260 ). The VMU contains the vector memory (not shown in FIG. 2 ). During each instruction it can send a line or a vector from the vector memory or receive a line into the vector memory. The same instruction may specify in addition a scalar send operation and/or a receive operation. The VMU is the only functional unit connected to the external world, i.e. to the external bus 110 .
[0038] The Code-Generation Unit (CGU 262 ). The CGU is specialized in finite-field arithmetic. For example, the CGU can be used for generating vectors of CDMA code chips as well as related functions, such as channel coding and CRC.
[0039] ALU-MAC Unit (AMU 264 ). The AMU is specialized in regular integer and fixed-point arithmetic. It supports inter-vector operations, where arithmetic is performed element-wise on multiple vectors. In a preferred embodiment, the AMU also provides some intra-vector operations, where arithmetic is performed on the elements within a single vector.
[0040] ShuFfle Unit (SFU 266 ). The SFU can rearrange elements of a vector according to a specified shuffle pattern.
[0041] Shift-Left Unit (SLU 268 ). The SLU can shift the elements of the vector by a unit, such as a word, a double word or a quad word to the left. The produced scalar is offered to its scalar section. Depending on the type of SLU vector-operation issued, the consumed scalar is either zero, or taken from its scalar section.
[0042] Shift-Right Unit (SRU 270 ). The SRU is similar to the SLU, but shifts to the right. In addition it has the capability to merge consecutive results from intra-vector operations on the AMU.
[0043] The following table shows that all FUs have a functional vector section 210 , where some do not have a control section 230 or scalar section 220 .
Functional Unit control scalar vector Instruction- sequencing, instruction Distribution looping distribution Unit Vector Memory address scalar i/o vector i/o Unit computation Code-Generation code vector Unit generation ALU-MAC indexing broadcast inter vector: ALU, Unit MAC, mul, . . . segmentation intra vector: add, max Shuffle Unit vector shuffle Shift-Left Unit scalar i/o vector shift Shift-Right Unit scalar i/o vector shift
[0044] The scalar/vector processor according to the invention applies instruction-level parallelism in two major ways: vector processing, where a single instruction operates on vectors of (scalar) data. This approach is also known as single-instruction stream, multiple-data stream or SIMD parallel processing of multiple functional units, each operating on vectors. This can be seen as a (restricted) form of VLIW instruction-level parallelism. Note that these two forms of instruction-level parallelism are independent, and that their effects are cumulative.
[0000] Inter-FU Communication
[0045] The functional units (FLY) operate in parallel. Each FU is capable of receiving and sending vector data. Many FUs are also capable of receiving and sending scalar data.
FU source vmu cgu amu sfu slu sru target #inputs vmu 1 ! ! ! ! ! ! cgu 1 ! ! ! ! ! amu 2 ! ! ! ! ! ! sfu 1 ! ! ! ! ! ! slu 1 ! ! ! ! ! sru 1 ! ! ! ! !
[0046] All functional units operate in parallel. Upon reception of their segment of an instruction, they input, process, and output data, both vector data and, where applicable, scalar data. Among FUs the communication is strictly among the scalar sections or among vector sections (inter-FU communication). That is, the vector sections of all FUs except the IDU are connected by a pipeline. In a preferred embodiment, this pipeline is configurable on instruction basis. To this end, preferably the FUs are interconnected by an interconnect network, in principle allowing each vector section to receive a vector from any the of other vector sections during each cycle. This feature enables, amongst others, the creation of arbitrary pipelines of the FUs (except the IDU). The six of the functional units that contribute to the vector path can output a vector and send it to other units in parallel during each clock cycle. They can also receive a vector from another unit. The network is nearly fully connected. Only links that are not meaningful have been omitted. The AMU can receive two vectors simultaneously. As shown in FIG. 2 , the network is preferably formed by each FU being connected as a signal source (indicated by a disc) to one network path. It is connected to all other paths as a signal sink (indicated by a triangle). The section of the VLIW instruction for the FU indicates from which path it should consume a vector. In this way the pipeline can be configured on an instruction basis. Each path can transfer a full vector, e.g. using 256 parallel wires. Similarly, at least some of the scalar sections of the FUs are connected by a separate pipeline. Preferably, this pipeline is also configurable on instruction basis. The interconnect network among the scalar sections of the FUs can be partial in the sense that no scalar can be sent to or received from a scalar section of at least one FU. Hence, fewer pipeline orderings can be specified. The scalar and vector pipelines can be configured independently. For example, by indicating in the relevant VLIW section both the scalar pipeline and the vector pipeline to be read by the functional unit.
[0047] There is no connectivity specified among the control sections of the different functional units. These control sections receive a segment of the VLIW instruction from the IDU, update their own state, and control their respective scalar and vector sections.
[0000] Intra-FU Communication
[0048] Within an FU there is tight interaction between these sections (intra-FU communication). The interaction is an integral part of the operation of the FU. Examples are the SLU and SRU, where the produced and/or consumed scalar is provided to/taken from the corresponding scalar section part of the FU.
[0049] Instructions are typically executed in a single cycle. Exceptions are caused by congestion at the vector memory and manifest themselves as stall cycles.
[0000] Data Widths
[0050] In a preferred embodiment, the scalar/vector processor supports a plurality of data widths and data types as shown in FIG. 3 . The basic unit of memory addressing is a word, also referred to as a single word. Preferably, data width can be a single word (W), double word (DW, or 2W=16 bits)), or quad word (QW or 4W=32 bits). The size of a word is W=8 bits. Preferably, scalars come in three sizes: (single) words, double words, and quad words. A vector has a fixed size of P Q quad words. It can preferably be structured in one of the three following formats:
P Q elements of size quad word,
P D =2P Q elements of size double word,
P S =2P D =4P Q elements of size (single) word.
[0051] The vector-element indexing range is [0 . . . 4P Q −1]. Hence double words have even indices and the indices of quad words are multiples of four. FIG. 3 gives an overview of the data sizes. The architecture is fully scalable in P Q and is defined for any vector size P Q ≧1. However, for most situations it is preferred to choose a power of 2 for P Q . In the preferred embodiment, P Q is 8, implying a data path width and memory width of 32 words.
[0000] Instructions
[0052] A CVP instruction is either a control instruction or a VLIW instruction. Control instructions may, for example, be zero-overhead loop initialization. There are no branches, jumps, or subroutines. A VLIW instruction is partitioned into segments, where each instruction segment specifies the operation(s) to be performed by the corresponding functional unit. The segment can be further subdivided in a part for the vector section, and the scalar section (if present). The segment also includes for both parts information on which network part to use for receiving data (one or more vectors for the vector section and one or more scalars for the scalar section).
[0000] State of the Scalar/Vector Processor
[0053] The state of the CVP is the combined states of its functional units. In the preferred embodiment, it comprises:
the vector memory (part of the VMU); the program memory (part of the IDU); vector registers (all functional units); scalar registers (most functional units); control registers, including the program counter, and address-offset registers.
[0059] In addition to the programmer-visible registers, a CVP realization typically contains additional registers (vector, scalar, and control) for pipelining and caching. These are not part of the CVP instruction-set architecture.
[0060] Some of the (vector, scalar, and control) registers are so-called configuration registers. The content of a configuration register can only be loaded from the vector memory; there is no other way to change its value. A configuration register supports the configuration of functional units, and typically defines a function parameter. By storing these “semi-constant” function parameters in configuration registers, both the instruction width and memory traffic are reduced considerably.
[0061] An overview of the components of the CVP state is presented in the table below.
control path scalar path vector path FU data configuration data configuration data configuration vmu offset 5 address cu 8 data memory 2048 cgu counter 3 codes 3 state 6 masks 2 polynomials 2 amu 1 receive 1 segment size 1 register file 16 sfu register 1 shuffle patterns 4 slu receive 1 register file 2 sru receive 1 register file 2 idu pc 1 loop cu 2 program mem. 2048
[0062] All programmer-visible registers can be loaded from the vector memory. All registers, except the configuration registers can be saved into the vector memory. By saving the CVP registers at the end of a stint, and by restoring them at a later time, the CVP can continue a particular task as if no other stints were executed meanwhile. These save and restore operations are optional, may be partial, and must be programmed explicitly.
[0000] The Memory Unit and AGUs
[0063] FIG. 4 shows a block diagram of the memory unit (VMU 400 ). In the preferred embodiment described below, the memory unit is used in a vector processor in combination with a physical memory with a width capable of storing an entire vector. It will be appreciated that the same concept may also be applied to scalar processors, such as conventional DSPs. The VMU contains and controls the vector memory 410 , which provides a huge data bandwidth to the other functional units. The physical vector memory 410 is preferably based on a single-ported SRAM. Since embedded SRAMs that are Ps*W wide are not generally available, the physical memory may be formed by one or more banks of wide Random Access Memories (RAM) arranged in parallel.
[0064] The VMU 400 includes at least one address-computation unit (ACU) 420 that support automatic address generation. Referring to the overall architecture of FIG. 2 , the ACU is assumed to be located in the control section 230 of the VMU 260 . It will be appreciated that the ACU need not be physically located in the VMU but may also be connected to it. Preferably, the ACU supports addressing modes (address generation algorithms) like those in conventional DSPs. The ACU performs one or more address calculations per instruction without using the processor's main data path. For example, the address of a scalar can be post-incremented after each scalar read access. This allows address calculation to take place in parallel with arithmetic operations on data, improving the performance of the processor. Depending on the set of addressing modes supported, such an ACU needs access to a number of registers. For example, relative addressing, i.e. addressing relative to a so-called base address, requires:
a base register base an offset with respect to the base address, stored in an offset register offs a pre/post increment of the offset by a value stored in an increment register incr modulo addressing with respect to an address stored in a bound register bound
[0069] With this set of addressing modes, the following can be supported. Assume an offset register offs. After each memory access (read or write) at address base +offs, register offs is updated according to offs:=(offs+incr) modulo bound. Hence, offs changes frequently (after every access), whereas the values stored in base, incr, and bound change infrequently. Typically those three latter registers are initialized prior to a program loop. The initialization of the set of registers is also described as “configuration of the ACU”. In order to avoid excessively long instructions and to avoid separate instructions on address calculations as much as possible, the control section of the VMU preferably includes a number of address computation units. Each address computation unit (ACU) can be associated with a set of (address) registers, and with an address calculation (“increment”) operation(s). The association between the ACU and the set of registers may be fixed (“hardwired”) or configurable, if so desired even at instruction level.
[0070] Assuming that the vector memory comprises 2 L lines, a scalar or vector address requires L+ 2 log 4P Q bits. With, for example P Q =8 and L=12, this means 17 bits. The registers of the ACU may have the same size as the address. If so desired, some of the register may be smaller. For example, increment may be limited to only relatively small steps, e.g. 8 bits. Preferably, all registers are equal size. A preferred embodiment is shown in the next table, where a set of ACU registers contains four address registers:
Name # bits Explanation Base 24 unsigned Address base register. Offs 24 unsigned Address offset from base. Incr 24 signed Increment value (−bound < incr < bound). Bound 24 unsigned Upper bound.
[0071] The preferred address range and type (signed/unsigned) is also indicated in the table. In this configuration, each ACU register is 24 bit. As will be described in more detail below, the ACU registers can stored to/loaded from the memory 410 . To simplify modification of a register when it is stored in the memory, a register width is chosen that is aligned with the basic unit for accessing the memory, i.e. on 8-bit word boundaries. Therefore, 24 bit registers are used instead of 17 bit that would be sufficient for the exemplary memory size. It will be appreciated that for certain address calculations also less than three registers are sufficient. It is thus possible to dedicate one or more sets of registers to such calculations, providing a saving in registers.
[0072] In the preferred embodiment, the VMU includes eight sets of ACU registers. This enables different address calculations for the vector section and scalar section of a functional unit. It also provides efficient support for multiple data rams in one algorithm where each data stream has its own pointers (and thus address calculations for calculating and updating of the pointer). Conventionally, configuration of an individual set of ACU registers took a few clock cycles per set. As such, the time required for configuration of ACU registers can become a bottle-neck. To overcome such a configuration delay, at least two registers pertaining to one set of ACU registers can be configured in a single operation. This can be realized by mapping all those ACU registers on a single memory word, such as a vector, and by using dedicated load and store instructions from the vector memory to the ACU memory. Preferably, the entire set of relevant registers of one set of ACU registers can be configured in a single operation of preferably one clock cycle. If the memory width allows, advantageously registers of more than one set of ACU registers can be configured in one operation. In the example, one set of four ACU registers requires 4*24=96 bits. As described earlier, preferably a vector is 256 bits wide. In such a case, the ACU configuration speed can be increased even further by mapping the registers of multiple sets to one memory line (vector). In the example, two sets of ACU registers can be mapped to one vector. This is also illustrated in FIG. 5 . A vector is indicated by number 500 and the quad word boundaries are shown. Two sets of ACU registers 510 and 520 are also shown. In the example, the ACU registers are 24 bits and as such do not correspond to one of the standard data sizes of the vector. To be able to also easily access the individual ACU registers through the vector memory, the special instructions for loading/storing the ACU registers to the memory ensure that the individual ACU registers are aligned on word boundaries (in the example, the 24 bits register are aligned on quad-word boundaries). Persons skilled in the art will be able to define an optimal mapping depending on the ACU register size and the vector size. For example, using 16 bit ACU registers and a 256 bit vector makes it possible to map four sets of ACU registers to one vector. In the instructions the numbers of the sets of ACU registers to be stored/loaded need to be indicated. Separate or combined instructions may be used for loading a single ACU register set or a group of ACU register sets. The group of ACU register sets to be loaded/stored may be fixed. For example, if the sets are identified by a number 0 to 7 , four fixed groups may be formed where the group number is the two most significant bits of the set. If so, desired groups may also be formed dynamically, for example by allowing more than one set to be specified in the load/store instruction.
[0073] FIG. 6 shows a set 610 of four ACU registers that is fixedly connected to an ACU 620 . Via paths 630 and 632 the registers' data is supplied to the ACU. The ACU supplies as output 640 the calculated address and at the output 642 the updated data for the registers. In the preferred embodiment with eight independent sets of ACU registers this may be duplicated eight times (not shown in the figure). FIG. 7 shows an alternative arrangement. In this arrangement eight sets of ACU registers are shown numbered 710 to 717 . A different number of ACUs are used. In this example, three ACUs are used, numbered 720 , 721 and 722 . The ACUs can be dynamically connected to one of the sets of registers. If so desired a full interconnect 730 may be present to enable connecting each of the ACUs to any one of the sets of registers. Of course, the interconnect 730 need not be full (for example, an ACU can only be connected to three or four sets). The interconnect 740 ensures that the updated register values can be supplied back to the desired set. Interconnect 704 mirrors interconnect 730 .
[0074] In the remainder a detailed description is given of the preferred VMU and ACUs. For this description it is assumed that each ACU is fixedly associated with one set of ACU registers. The VMU can be partitioned into a control, scalar and vector section. These sections will be modeled according to a Moore machine model, comprising five elements: inputs, outputs, state, next-state function, and output function. The state of the Moore machine is determined by the available memory and/or register(s). For each functional unit, a table is given that defines all allowed transitions, including the corresponding guards. A guard is the condition that needs to be true for the transition to occur. The transitions define the next-state functions and the output functions of the Moore machine. In the tables square brackets are used to select an element within a vector. For example: v[p] denotes element p of vector v.
[0075] The vector-memory unit can support up to four concurrent “sub-operations” in a single VMU instruction:
send a vector, or send a line, or receive a line from/to VM location (vector sub-operation); send a scalar from a VM location (send scalar sub-operation); receive a scalar to a VM location (receive scalar sub-operation); modify the state/output of an address computation unit (ACU sub-operation.
[0080] Parameters for each of those four concurrent instructions are all given in the following VMU command (VMU_cmd), where the vector sub-operation is specified by vopc, aid_v, and ainc_v, the send scalar sub-operation is specified by sopc, aid_s, and ainc_s, size, the third receive scalar sub-operation is specified by srcv, aid_r, and ainc_r, and the ACU sub-operation is specified by aopc, aid_a, and imm_addr. Whereas the fourth operation directly controls one of the ACUs, the other three operations may as a side effect also control an ACU as will be described below in more detail.
VMU_cmd=(vopc, aid_v, ainc_v, sopc, aid_s ainc_s, size, srcv, aid_r, ainc_r, aopc, aid_a, imm_addr) vopc=NOP|SENDL|SENDV|RCVL_CGU|RCVL_AMU|RCVL_SFU|RCVL_SLU|RCVL_SRU aid_v={0, . . . , 7} ainc_v=NOP|INC sopc=NOP|SEND aid_s={0, . . . , 7} ainc_s=NOP|INC size=WORD|DWORD|QWORD srcv=NONE|VMU|AMU|SLU|SRU aid_r={0, . . . , 7} ainc_r=NOP|INC aopc=NOP|IMM|LDBASE|LDOFFS|LDINCR|LDBOUND aid_a={0, . . . , 7} imm_addr={0.0, . . . , 524288.31}|{−262144.0, . . . , 262143.31}
[0095] The VMU instruction may take a variable number of clock cycles, depending on the number of sub-operations and the continuity of address sequences.
[0096] The VMU Inputs/Outputs Are:
Explanation Input Cmd VMU command rcv_amu AMU vector receive bus rcv_cgu CGU vector receive bus rcv_sfu SFU vector receive bus rcv_slu SLU vector receive bus rcv_sru SRU vector receive bus s_rcv_amu AMU scalar receive bus s_rcv_slu SLU scalar receive bus s_rcv_sru SRU scalar receive bus Output Snd VMU vector result s_snd VMU scalar result
[0097] In addition there are two scalar ports (one send, one receive) to be connected to the external bus. Synchronization of these memory accesses with CVP instructions is the task of the micro-controller 130 .
[0098] The VMU Vector Section Contains the Physical Vector Memory 410 :
Name Explanation mem[4096][32] Vector memory: 4096 lines of 32 words each
Vector Sub-Operations
[0099] Note that vector sub-operations cannot access the scalar memory. Hence, the most significant address bit is ignored for vector sub-operations. The vector section of the VMU supports seven sub-operations, encoded in the VOPC field of the instruction: vector send ( SENDV ), line send ( SENDL ), and five line receive sub-operations ( RCVL _CGU, RCVL_AMU, RCVL_SFU, RCVL_SLU, and RCVL _SRU). The seven sub-operations can not be executed simultaneously. Only one sub-operation can be specified at a time. The functional unit that is the source of the receive is explicitly encoded in the corresponding line receive sub-operation. The read address or write address for each sub-operation is specified by a corresponding address computation unit. The AINC _V field is shared between all vector sub-operations. It will be passed on to the ACU encoded in the AID _V field. In this way the specified ACU is controlled as a side-effect of a vector sub-operation. The AINC _V field specifies whether the affected address computation unit should perform a post-increment operation.
Guard Transition vopc = NOP None vopc = SENDL snd = mem.line[acu[aid_v].out] vopc = SENDV snd = mem.vector[acu[aid_v].out] vopc = RCVL_CGU mem.line[acu[aid_v].out] = rcv_cgu vopc = RCVL_AMU mem.line[acu[aid_v].out] = rcv_amu vopc = RCVL_SFU mem.line[acu[aid_v].out] = rcv_sfu vopc = RCVL_SLU mem.line[acu[aid_v].out] = rcv_slu vopc = RCVL_SRU mem.line[acu[aid_v].out] = rcv_sru
Note that the operations are cast as send (or receive) actions, and not as load (or store) actions involving a destination (or source). The latter are specified by operations in other functional units. A line send is functionally equivalent to a vector send with the same address. Line-send sub-operations are typically used to configure functional units, or to restore the state of a task in the various registers. By introducing a special mode for line send, the access times of successive vector sends (“vector streaming”) can be optimized through efficient usage of caches.
[0100] The scalar send sub-operation of the VMU is encoded in the SOPC field of the instruction. It supports only one sub-operation: scalar send ( SEND ). The read address is specified by the address computation unit specified in the AID _S field. The AINC _S field of the instruction specifies whether this address computation unit should perform a post-increment operation. In this way a second ACU can be controlled indirectly (the first one being controlled via the vector sub-operation). The operand size ( WORD, DWORD or QWORD ) of the scalar sub-operation is determined by the SIZE field of the instruction.
Guard Transition sopc = NOP None sopc = SEND && size = WORD S_snd = mem.word[acu[aid_s].out] sopc = SEND && size = DWORD S_snd = mem.dword[acu[aid_s].out] sopc = SEND && size = QWORD S_snd = mem.qword[acu[aid_s].out]
[0101] The scalar receive sub-operation of the VMU is encoded in the SRCV field of the instruction. If its value is NONE , no scalar receive is performed. Otherwise, the SRCV field of the instruction determines which functional unit will be used as source for the scalar receive. The write address is specified by the address computation unit specified in the AID _R field. In this way a third ACU can be controlled indirectly. The AINC _R field of the instruction specifies whether this address computation unit should perform a post-increment operation. The operand size ( WORD, DWORD or QWORD ) of the scalar receive sub-operation is determined by the size of the source scalar.
Guard Transition Srcv = NONE None Srcv = VMU Mem.scalar[acu[aid_r].out] = s_rcv_vmu Srcv = AMU Mem.scalar[acu[aid_r].out] = s_rcv_amu Srcv = SLU Mem.scalar[acu[aid_r].out] = s_rcv_slu Srcv = SRU Mem.scalar[acu[aid_r].out] = s_rcv_sru
[0102] The send and receive sub-operation can be combined into a scalar move operation, from one VM location to another. The address for each access is specified by a corresponding address computation unit.
[0103] As described above, in this way each of the ACUs can be assigned flexibly to any of the VMU sub-operations of vector, scalar send and scalar receive. In this way, three ACUs can be operated in each instruction. To avoid conflicts, a restriction is that each ACU may only be used for one of those VMU sub-operations, i.e. AID _V≠AID_S≠AID_R. Persons skilled in the art will be able to adjust the instruction and underlying hardware to support more than three ACU's if so desired or to support other configuration between the ACU and the set of ACU registers. For example, if a set of registers is not fixedly assigned to an ACU, then the instruction may also carry an identification of the set to be used.
[0104] The ACU sub-operation is provided by the VMU control section and encoded in the AOPC field of the VMU instruction. It supports one sub-operation to set the output of an ACU to an immediate address value (IMM), and four sub-operations to load an immediate address into one of the ACU-registers ( LDBASE, LDOFFS, LDINCR , and LDBOUND ). The purpose of the immediate addressing is to bypass the regular addressing and ‘quickly’ retrieve an address directly from the instruction. This is particularly useful for loading of a single word. The corresponding immediate address is encoded in the IMM _ADDR field. The AID _A field specifies which ACU is to be affected by the AOPC sub-operation; the AOPC field and IMM _ADDR field from the VMU instruction will be passed on directly to this particular ACU, and the AOPC field of all other ACUs will be set to no operation ( NOP ).
[0105] An address computation unit (ACU) can support two “sub-operations” during a single ACU operation:
A post-increment sub-operation; An immediate address manipulation sub-operation. ACU_cmd=(ainc, aopc, imm_addr) ainc=NOP|INC aopc=NOP|IMM|LDBASE|LDOFFS|LDINCR|LDBOUND imm_addr={0.0, . . . , 524288.31}|{−262144.0, . . . , 262143.31}
[0112] The post-increment sub-operation is encoded in the AINC field of the instruction. It supports only one sub-operation: post-increment ( INC ). This sub-operation is used to avoid excessive explicit address calculation instructions.
Guard Transition ainc = NOP None ainc = INC offs = (offs + incr) mod bound
[0113] The immediate address manipulation sub-operation is encoded in the AOPC field of the instruction. It supports one sub-operation to output an immediate address ( IMM ), and four sub-operations to load an immediate address into one of the ACU-registers ( LDBASE, LDOFFS, LDINCR , and LDBOUND ). The immediate address is encoded in the IMM _ADDR field of the instruction.
Guard Transition aopc = NOP out = base + offs aopc = IMM out = imm_addr aopc = LDBASE out = base + offs; base = imm_addr aopc = LDOFFS out = base + offs; offs = imm_addr aopc = LDINCR out = base + offs; incr = imm_addr aopc = LDBOUND out = base + offs; bound = imm_addr
[0114] The ACU Inputs/Outputs Are:
Explanation Input Cmd ACU command (see instruction format for details) Output Out ACU address (line address + scalar within line)
[0115] In the preferred embodiment, a vector needs not to be aligned at vector boundaries in the memory. As such, a vector consisting of P S words may have an arbitrary memory address. A memory line has the same size, but its start address is by definition a multiple of P S . (For line accesses, the least significant 2 log P S bits of the address are ignored.) By allowing arbitrary alignment of vectors (typically alignment on the smallest word boundary), the memory can be utilized better, with less empty locations. Measures may be taken for allowing the scalar/vector processor to read/write individual vectors whereas the vector may be stored in two consecutive lines of the physical memory. Preferably, the scalar data is stored in the same memory as used for storing the vector data In such a system, scalars can be intermixed with vectors to which they correspond. For cost-effectiveness and optimum access time to the memory, the memory preferably only allows reading and writing of full vector lines. As such, logically the physical memory consists of lines, each of the size of a vector. To support reading and writing of scalars additional hardware (line caches 430 and support 440 for scalar selection within a line) is used to access the vector-wide physical memory in a scalar fashion.
[0116] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The words “comprising” and “including” do not exclude the presence of other elements or steps than those listed in a claim.
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A processor includes a memory port for accessing a physical memory under control of an address. A processing unit executing instructions stored in the memory and/or operates on data stored in the memory. An address generation unit (“AGU”) generates address for controlling access to the memory; the AGU being associated with a plurality of N registers enabling the AGU to generate the address under control of an address generation mechanism. A memory unit is operative to save/load k of the N registers, where 2<=k<=N, triggered by one operation. To this end, the memory unit includes a concatenator for concatenating the k registers to one memory word to be written to the memory through the memory port and a splitter for separating a word read from the memory through the memory port into the k registers.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a cable processor for accommodating an air pipe and electrical wire, which will be referred to as “a cable” hereinafter in this specification, inside an arm of a robot.
[0002] Concerning the conventional processing method of processing a cable in the case of accommodating the cable inside an arm of a robot, there is provided a method in which the cable is elastically wound and accommodated in the arm. Concerning this method, for example, refer to Patent Document 1. Further, there is provided a support device in which a cable is extended in a flexible conduit while extended half round in the forward direction and then folded back upward in the U-shaped direction and extended in the flexible conduit half round in the backward direction so that the cable can be accommodated inside the arm. Concerning this support device, refer to Patent Document 2.
[0000] [Patent Document 1]
[0003] JP-A-8-57792
[0000] [Patent Document 2]
[0004] Japanese Patent No. 3452811
[0005] However, according to the method disclosed in Patent Document 1, the following problems may be encountered. In the case where cables are supplied to a plurality of hands attached to a forward end of an arm, it is necessary to provide one or more cables which are elastically wound round a circle, the diameter of which is larger. Therefore, the diameter of the joint portion of a robot is increased. Further, since the cable is elastically wound round the circle, it becomes necessary to provide a space in the direction of the winding shaft. Accordingly, the robot arm is extended in the rotary shaft direction of the joint portion.
[0006] In the support device disclosed in Patent Document 2, since the cable is folded back by a U-shape, the size of the robot joint portion is increased in the direction of the rotary shaft.
SUMMARY OF THE INVENTION
[0007] The present invention has been accomplished to solve the above problems of the prior art. It is an object of the present invention to provide a cable processor capable of supplying cables to a plurality of hands attached to a forward end of an arm without increasing the size of a joint portion of a robot and further without causing a problem of the breaking of wire at the time of operating the robot.
[0008] In order to solve the above problems, the present invention has the following constitution.
[0009] The invention described in aspect 1 provides a cable processor of a robot for accommodating a cable such as an air pipe or electric wire inside an arm of the robot, the cable processor comprising: a casing portion for accommodating the cable, arranged in a joint drive portion of the robot, and rollers arranged on an inner wall of the casing, rotating round a drive shaft of the joint portion.
[0010] The invention described in aspect 2 provides a cable processor of a robot, wherein an upper face and a lower face inside the casing are subjected to the treatment of fluorine contained resin.
[0011] The invention described in aspect 3 provides a cable processor of a robot, wherein the contour of the casing is the same as that of the robot arm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a sectional side view of the arm of the embodiment of the present invention.
[0013] FIG. 2 is an upper view of the arm of the embodiment of the present invention.
[0014] FIG. 3 is a perspective view of the arm of the embodiment of the present invention.
[0015] FIG. 4 is a perspective view of the casing of the embodiment of the present invention.
[0016] FIG. 5 is an upper view of the peripheral portion of rollers provided in the casing.
[0017] FIGS. 6A and 6B are upper views showing a motion of the cable accommodated in the casing when the hand is rotated.
[0018] FIGS. 7A and 7B are upper views showing a motion of the cable accommodated in the casing when the hand is rotated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring to the drawings, a specific embodiment of the method of the present invention will be explained below.
Embodiment 1
[0020] FIG. 1 is a view showing an example of the arm of the horizontal multiple joint robot in which the mechanism of the present invention is used.
[0021] FIG. 1 is a sectional central view showing a side the arm, and FIG. 2 is an upper view showing the arm. In this connection, in order to simplify the explanations, the cover and the other members are removed from FIG. 2 .
[0022] As shown in FIG. 1 , the robot includes a first arm 1 and a second arm 2 . The first arm 1 on the base portion side is fixed to the shaft 3 which is moved upward and downward and rotated in a predetermined range. The second arm is attached to the first arm 1 via the bearing. 4 so that the second arm can be rotated in a predetermined range.
[0023] Two hands for seizing and conveying a workpiece are attached to the forward end of the second arm in such a manner that the two hands are vertically put on each other. In this case, the forward end portions of the two hands are omitted in the drawing. Mechanisms for driving the hands 5 , 6 are built in the first 1 and the second arm 2 .
[0024] When the motor 7 is rotated, the torque generated by the motor 7 is intensified by the speed reducer 9 , and the thus intensified torque is transmitted to the pulley 16 by the motor side pulley 11 and the belt 13 , and the pulley 16 rotates the hand 6 via the bearing 18 .
[0025] In the same manner as that described above, when the motor 8 is rotated, the torque generated by the motor 8 is intensified by the speed reducer 10 , and the thus intensified torque is transmitted to the pulley 15 by the motor side pulley 12 and the belt 14 , and the pulley 15 rotates the hand 5 via the bearing 17 .
[0026] As shown in FIG. 3 , by the mechanism described above, the hands 5 , 6 , which are arranged on the same rotating shaft, are operated independently from each other. In this connection, the motor 8 and the speed reducer 10 are located below the motor side pulley 12 in FIGS. 2 and 3 . However, since the motor 8 and the speed reducer 10 are located on the viewer's side of the sectional central view of FIG. 1 , they are not drawn in FIG. 1 .
[0027] An air pipe and electrical wire, which will be referred to as a cable hereinafter, are supplied to the hand 5 via a hollow portion of the pulley 15 . On the other hand, the cable 21 is supplied to the hand 6 via the casing 20 . The cable 21 is fixed to the support 22 in the second arm 2 . Then, the cable 21 passes through in the casing 20 and fixed to the fixing part 25 which is subordinately operated together with the hand 6 .
[0028] The cables 19 , 21 are used as electric power source wires or signal wires connected to the sensors mounted on the hands 5 , 6 . Further, the cables 19 , 21 are also used as pipes for supplying air to drive the cylinders, which are mounted on the hands 5 , 6 , or supplying vacuum air used for sucking a workpiece.
[0029] FIG. 4 is a perspective view taken in the direction of arrow A in FIG. 1 . FIG. 4 is a view drawn when the casing 20 is taken out from the second arm 2 . As shown in FIG. 4 , a plurality of roller shafts 24 are arranged in the casing 20 along the inner wall of the casing 20 . The pipe-shaped rollers 23 are arranged in such a manner that each roller shaft 24 is inserted into the hollow portion of each pipe-shaped roller 23 .
[0030] FIG. 5 is an upper view of each roller 23 and roller shaft 24 arranged in the casing 20 . The inner diameter of the hollow portion of the roller 23 is larger than the outer diameter of the roller shaft 24 , and the outer diameter of the roller 23 is smaller than the distance (d in the drawing) from the center of the roller shaft 24 to the inner wall of the casing 20 . Therefore, the roller 23 can be freely rotated in the direction of an arrow shown in FIG. 5 .
[0031] FIGS. 6 and 7 are upper views showing a state in which the cable 21 accommodated in the casing 20 is acted when the hand 6 is rotated.
[0032] For example, when the hand 6 is rotated in the direction of the reference sign + shown in FIG. 3 , the fixing part 25 is rotated in the direction of an arrow shown in FIG. 6A and the cable 21 in the casing 20 is pulled to the hand 6 side, and the cable 21 is wound round the fixing part 25 , to which the hand 6 is attached, as shown in FIG. 6B .
[0033] On the contrary, when the hand 6 is rotated in the direction of the reference sign − shown in FIG. 3 and the fixing part 25 is rotated in the direction of an arrow shown in FIG. 7A and the cable 21 in the casing 20 is pushed from the hand 6 side, as shown in FIG. 7B , the cable 21 , which is wound round the fixing part 25 , spreads in the casing 20 and comes close to the inner wall of the casing 20 . However, since the rollers 23 are arranged on the inner wall, the inner wall of the casing 20 and the cable 21 are not directly contacted with each other. Due to the foregoing, the contact area can be reduced and the frictional resistance can be decreased.
[0034] Further, as described before, since the rollers 23 can be freely rotated round the rotary shaft of the hand 6 , the frictional resistance caused when the cable 21 moves on the wall face of the casing 20 can be reduced. That is, even when the hand 6 is rotated, the cable 21 can be smoothly moved inside the casing 20 . Therefore, no stress and tension are given to the cable 21 , and the breaking of wire, which is caused by the repeated motions, can be prevented.
[0035] Although not shown in the drawing, the upper and lower faces inside the casing are subjected to the treatment of fluorine contained resin. Since the coefficient of friction of fluorine contained resin is low, the cable 21 inside the casing 20 can be more smoothly slid, which can contribute to a reduction of the sliding resistance of the joint portion and a prevention of the breaking of wire of the cable 21 . In this connection, the upper and lower faces inside the casing are not necessarily subjected to the treatment of fluorine contained resin. Alternatively, a tape, which is subjected to the treatment of fluorine contained resin, may be stuck on the inner surface of the casing 20 .
[0036] As can be understood from FIGS. 2 and 3 , the contour of the casing 20 is the same as that of the second arm 2 . Concerning the volume of the casing 20 , it is sufficient to prepare an area for accommodating the cable 21 which is wound round and separated from the fixing part 25 according to the rotary motion of the hand 6 and also to prepare an area for accommodating the rollers 23 . Concerning the direction of height, it is sufficient to prepare a size of the diameter of the cable 21 . Further, concerning the inside of the forward end portion of the second arm 2 , it is sufficient to provide a space in which the cable 21 can pass through. Therefore, an increase in the size of the robot joint portion of the cable processor of the present invention can be prevented.
[0037] In this embodiment, explanations are made into a case of the robot having two hands attached to the forward end portion of the arm and the rotary shafts of the two hands are arranged in the same axis. However, even when the number of hands is not less than 3, as long as the casing 20 is put in the direction of the rotary shaft of the hand, the present invention can be also applied. In this case, since the contour of the casing 20 is the same as that of the arm as described above, an area of the arm is not increased when a view is taken in the direction of the rotary shaft of the hand. Therefore, it is possible to reduce the space.
[0038] In this connection, explanations are made into a case of the horizontal multiple joint robot. However, the embodiment of the present invention is not limited to the above specific case. The present invention can be applied to a robot having a rotary shaft such as a vertical multiple joint robot.
[0039] The present invention can be applied to joint portions of various type robots and mechanisms in which cables extended to a forward end portion of the drive portion are accommodated.
[0040] According to the invention described in aspect 1 , it is possible to downsize the joint portion of a robot. Further, when the joint is rotated, the cable can be smoothly moved. Therefore, the sliding resistance of the joint portion of the robot can be decreased. Furthermore, since no stress is given to the cable itself, the breaking of wire and the leakage of air can be prevented.
[0041] According to the invention described in aspect 2 , the friction of the cable can be further decreased at the time of rotating the joint.
[0042] According to the invention described in aspect 3 , even in the case of a robot having a plurality of hands at the forward end of the arm, cables can be supplied to the respective hands without increasing the size of the joint portion.
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The present invention provides a cable processor capable of supplying cables to a plurality of hands attached to a forward end portion of an arm without increasing the size of a joint portion of a robot and further without causing a problem of the breaking of wire at the time of operating the robot.
There is provided a cable processor of a robot for accommodating a cable such as an air pipe or electric wire inside an arm of the robot, and the cable processor comprises: a casing portion ( 20 ) for accommodating the cable ( 21 ), arranged in a joint drive portion of the robot, wherein the casing portion ( 21 ) is provided with rollers ( 23 ), which are arranged on an inner wall of the casing portion ( 21 ), rotating round a drive shaft of the joint portion.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] (1) Field of the Invention
[0004] The disclosure relates to introducing a pattern onto the surface of elastomeric fabric supported gloves made from conventional sulphur vulcanised formulations in the wet gel state using an engraved moulding plate, and a flat former using compression moulding technique. The pattern so produced is permanent, uniform throughout the whole of the patterned area, and may be of any design—single pattern or multi pattern. The pattern so formed also provides the glove with enhanced grip as a consequence of the uniformity of the pattern.
[0005] (2) Description of Related Art
[0006] Conventional methodology for making patterns on supported gloves rely on the following techniques: screen printing elastomer-pattern is provided from pattern on screen; use of a solvent/solvent mixture to provide a pattern to the dipped glove during the production process; laminating with the aid of an adhesive pre-embossed piece of elastomer film onto a supported glove; laminating a liner onto a glove which has been previously dipped onto a former containing a patterned surface using an adhesive; and/or laminating a glove onto a liner dressed onto a former using an adhesive of a mould that has convex patterns on it so that when a glove is manufactured using a dipped process, the glove contains concave indentations that give a gripping effect. Practically, these gripping areas are considerably large, work well on flat surfaces only and apply only to an un-supported glove.
[0007] WO 2006/053140 describes a method of producing grip-enhanced gloves by using negatively and positively pattered moulds. In this method, gripping elements could be made very small, but due to the fact that two plates—negative and positive—are used, this method cannot be used to transfer patterns to supported (using liners made of textile, aramides, etc.) gloves.
[0008] U.S. Pat. No. 5,098,755 describes a means of embossing uniform patterns onto films of thermoplastic elastomers. It also refers to applications on condoms and certain other items such as surgical gloves made from thermoplastic elastomers. Thermoplastic elastomers are a special type of material composed at a molecular sub micron level of hard and soft domains. They are different from conventional elastomers. The strength of the thermoplastic material is present by virtue of the hard and soft domains. Therefore Thermoplastic materials can easily be reshaped heated (embossed) and cooled, and the embossing effect will prevail until it is heated above the softening point of the hard blocks.
[0009] U.S. Pat. No. 4,283,244 refers to making fabric lined elastomeric articles, wherein the pattern is on the outside. This process involves a methodology wherein a composite liner is dressed onto an uncured latex glove prior to oven cure and stripping the composite liner from the glove. After stripping, the glove is turned inside out and the pattern is on the outer surface.
[0010] Normally in supported glove manufacturing involving latex systems based on natural rubber latex, nitrile latex, neoprene latex, and SBR latex, embossing the pattern onto a glove during the wet gel state of the glove manufacturing operation has not been performed. Patterns are introduced to enhance grip, and in conventional technology the pattern is made by using the methodology identified in (b) above, in which the pattern is introduced to the glove by dipping into a solvent or solvent mixture prior to vulcanisation whilst still in the wet gel state. The pattern so formed is often wavy and non-uniform (i.e. the intensity of pattern varies along patterned area).
[0011] Therefore there exists a need to emboss different types of patterns and have a uniform pattern distribution in supported glove manufacturing after dipping and prior to vulcanisation. The present application provides a solution for this need.
BRIEF SUMMARY OF THE INVENTION
[0012] In the present disclosure, a pattern is introduced to the elastomeric component of the supported glove whilst in the wet gel state prior to vulcanisation. The pattern formed by the present methodology is uniform throughout the whole of the patterned area. Furthermore, the pattern can be of any design and variations being limited to what can be embossed on to the metal plate employed to impart the pattern on to the elastomer. Employment of such a methodology provides an easy method that transfers patterns consistently onto an elastomeric supported glove surface to render the glove more aesthetically pleasing and/or incorporate other desirable patterns such as company logos or brand names and/or give the glove a higher degree of flexibility and/or give the glove a better gripping ability, also to facilitate better wet grip.
[0013] The present process applies to conventional latex elastomers, which require chemicals to be added to the elastomer during the manufacturing process (e.g. vulcanising ingredients mixed into latex) in which the strength is achieved by a vulcanising process and application of heat in an oven. The product so formed is a thermoset. In our process the embossing is performed prior to vulcanisation in the wet gel state stage of the operation. Furthermore, once vulcanised the embossed effect is permanent. The latex we are working with is a conventional rubber (natural rubber, nitrile rubber, neoprene rubber), which requires vulcanising ingredients to impart strength to the elastomer.
[0014] The present disclosure provides a supported elastomeric glove with an enhanced gripping surface and a method of transfer of patterns onto a glove outer surface using a preformed moulding plate/mould other than the glove fabricating mould itself without the use of a solvent process in the wet gel state prior to vulcanisation of the elastomer. It applies to gloves made by a dipping process using latex as the elastomer.
[0015] Furthermore the pattern transfer process may also be applied to rubbers dissolved in solvents prior to the vulcanisation operation. The pattern may take any shape and any such pattern can be transferred onto the glove using the compression moulding method. The pattern shall be used to enhance the aesthetic appearance of the glove or the functionality of the glove in terms of better grip and/or higher flexibility. The pattern may or may not be uniform throughout the surface. The pattern can either cover the outer surface completely or only part/parts of it. The pattern can also have company logos, brand names or other shapes incorporated into it giving variation in the pattern within a glove. The glove may be made of any natural or synthetic elastomer or a blend thereof. The fabric liner may be made of any knitting yarn or made by cutting and sewing.
[0016] The process disclosed in the present application eliminates the need to have negative and positive plates as mentioned in the prior art. This process makes it much easier to have wide variety of patterns because only one plate needs to be cut where a matching negative plate is not required. This process does not alter the dimensions of the glove; compression moulding process removes entrapped water, which is also advantageous when energy required for curing is considered. The methods described in prior art cannot be used to make a pattern on a supported glove.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1 is a plan view of a glove generally shown prior to pattern being transferred using the present process of the application.
[0018] FIG. 2 shows a flat former used in compression moulding.
[0019] FIG. 3 shows the process of moulding a pattern onto the latex dipped supported glove using compression moulding.
[0020] FIG. 4 is a plan view of a glove manufactured using the present process of the application.
[0021] FIG. 5 shows an engraved plate used in compression moulding.
[0022] FIG. 6 shows a non-exhaustive list of example patterns that may be a transferred to an elastomeric glove by the process described in the present application.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIG. 1 , a fabric supported elastomeric glove ( 10 ) is generally shown. The present disclosure relates to a method of transferring patterns (see FIG. 6 ) onto a fabric supported elastomeric glove surface ( 12 ) rendering the glove ( 10 ) aesthetically pleasing and having enhanced gripping properties compared to a supported glove made with a natural or synthetic fibre based liner (not shown) coated with Natural Rubber or Synthetic elastomer or a blend thereof, consisting of a permanent pattern impression (see FIG. 6 ) made by a non chemical process on the palm ( 13 ) and fingers ( 15 ) to improve grip and other properties related to the usage of the glove ( 10 ). A drying process of the glove ( 10 ) is interrupted at a stage where the gel strength of the glove film (not shown) is such that it could withstand compression force without cracking up, or disintegrating. The glove ( 10 ) is then removed from a dipping former (not shown) and dressed on to a flat former ( 14 ), as shown in FIGS. 2 and 3 .
[0024] The surface ( 12 ) of the glove ( 10 ) is then subjected to compression force by a hydraulic machine ( 16 ), shown generally in FIG. 3 , to leave a desired imprint (See FIG. 6 ) on the elastomeric surface ( 12 ), which will become a special grip pattern, such as one selected from FIG. 6 .
[0025] The special grip pattern on the elastomer can have any design but a series of square depressions ( 18 ), as shown in FIG. 4 , which will come into contact with a handled object (not shown), is recommended for better grip.
[0026] The introduction of the grip pattern by pressing and moulding the elastomer glove ( 10 ) using a preformed engraved moulding plate ( 20 ) makes it possible for the formation of a series of depressions ( 18 ), which are very uniform in arrangement and dimensions on the elastomer glove ( 10 ).
[0027] There is provided according to one embodiment of the present disclosure a glove ( 10 ) with a polycotton fabric lining (not shown) and a natural rubber partial coating (not shown) with a preformed moulded pattern (See FIG. 6 ).
[0028] A latex based compound for an elastomer film is made using accelerators, activators, sulphur which are mixed using high speed stirrers, ball mills, etc. A textile liner is made by special purpose glove knitting machine of gauge 10 (or 13, 15, 18 or using Whole Garment Technology™ (WG)) with poly cotton 65:35 yarn. This liner can be replaced with a cut and sewn liner if it is desired. The gloves may be made of any blends of material or any knitted/woven material derived from cotton, nylon, polyester, polyester cotton, wool, para-aramid synthetic fiber, thermoplastic polyethylene, leather, or other engineering yarns. Commonly the latex includes natural rubber latex, nitrile latex/dispersions, neoprene latex, either by themselves or in combination with each other as blends. Other less common latex types based on other elastomers where chemicals are added to vulcanise the elastomer (e.g. Styrene butadiene rubber, silicone rubber, cis poly isoprene, butyl rubber, guaule rubber, etc.) may also be used to make the gloves.
[0029] The liners are dressed on to a mould ( 14 ). The mould ( 14 ) referred to here consists of five fingers ( 22 ), palm ( 24 ) and section of arm ( 26 ), where the hand is shaped to suit the dipping operation, and is made of Aluminum, Ceramic, or with heat resistant polymer resin. Then the dressed liner is dipped in elastomer to obtain a precise coating of elastomer using special purpose dipping machine or a robotic arm.
[0030] The elastomer coated liner is then dried and dipped in a special solvent free compound to increase the gel strength of the elastomer coating for the next process to take place.
[0031] A pre designed pattern (See FIG. 6 ) is engraved on to a engraved plate ( 20 ) for formation of a grip pattern (See FIG. 6 ). A engraved plate ( 20 ) is cut using a programmable robot (not shown) programmed on three axis to cut a precise pattern (see FIG. 6 ), having specific length, breadth and depth as shown in FIG. 5 . The robot is used to get a precise finish. A engraved plate can be cut also using other conventional tools and techniques, or by a chemical engraving process.
[0032] The pattern is cut on the engraved plate ( 20 ) which has sufficient thickness ( 28 ) for cutting and strength to prevent deformation during heating and compression. If a logo (not shown) is intended for the glove ( 10 ) then in fabrication of the engraved plate, the logo is embedded at the base of the engraved plate. The location of the logo is carefully selected so that the logo appears at the base of the palm ( 13 ) or elsewhere; which does not hinder the function of the elastomer surface ( 12 ) in gripping an object. Alternatively chemical engraving of the metal plate ( 20 ) is also possible. The engraved plate ( 20 ) is fixed to preferably a hydraulically operated pressing machine ( 16 ) designed to deliver a specific predetermined force/pressure. The engraved plate could be heated by suitable means ( 30 ) to achieve a temperature of around 50-100° C. before pressing is done.
[0033] The partially dried supported glove ( 10 ) is removed whilst still in a wet gel state and dressed on to a special moulding plate called a flat former ( 14 ). The flat former ( 14 ) is made of a metal plate with sufficient thickness ( 32 ), has five fingers ( 22 ), palm ( 24 ), and section of aim ( 26 ), and called a flat former due to its shape. The glove ( 10 ) is dressed onto it carefully. The dressed glove ( 10 ) is then placed on the lower platen ( 34 ) of the hydraulic press machine ( 16 ) and compressed under the engraved plate ( 20 ) to make an impression on the elastomer surface ( 12 ). The pressure is controlled so that the elastomer ( 12 ) is not damaged. In engraving the pattern (see FIG. 6 ) onto the engraved plate ( 20 ), care has to be taken to not to have edges too sharp which will cut in to the elastomer surface ( 12 ) of the glove ( 10 ) and ruin its performance. This is achieved in designing phase of pattern. The glove ( 10 ) with the moulded pattern (see FIG. 6 ) is then removed from the flat former ( 14 ), washed, dressed onto another former (not shown) and cured completely in a curing oven having temperature controls and moisture management technology.
[0034] In another embodiment, instead of working with latex, the former ( 14 ) pre-dressed with a liner is dipped into a solution (not shown) of an elastomer+vulcanising ingredients. After full or partial drying of the solvent, the supported glove ( 10 ) is embossed with a pattern as described above prior to curing whilst still in the wet gel state or fully uncured state prior to full vulcanisation in an oven. In such an instance prior to making the solution of the elastomer, the vulcanising agents and other formulation ingredients are either mixed into the solid elastomer in a mill (2-roll mill, Bambury, Busco-Kneader, or other type of mill used for milling ingredients into solid rubber), a technique well known to those working in the field of solid rubber mixing or they are added to a solution of the elastomer in the solvent as solutions/dispersions in suitable miscible solvents.
[0035] While the present description relates to the manufacture of the said glove ( 10 ) it will be understood that the present disclosure can easily be applied to the manufacture of any other type of fully elastomeric glove or glove with a fabric liner and a partial or full elastomeric coating by those of ordinary skill in the art of glove manufacture.
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A semi cured supported elastomeric glove with enhanced gripping surfaces achieved by the method of transferring of patterns by compression moulding, including a plurality of concave indentations of any pattern and moulded into the gripping surfaces of the semi cured glove.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of semiconductor devices and, in particular, to the formation of bond pads for memory and other integrated circuit devices.
BACKGROUND OF THE INVENTION
[0002] A well known semiconductor memory component is random access memory (RAM). RAM permits repeated read and write operations on memory elements. Typically, RAM devices are volatile, in that stored data is lost once the power source is disconnected or removed. Examples of RAM devices include dynamic random access memory (DRAM), synchronized dynamic random access memory (SDRAM) and static random access memory (SRAM). In addition, DRAMS and SDRAMS also typically store data in capacitors, which require periodic refreshing to maintain the stored data.
[0003] Recently, resistance variable memory elements, which include Programmable Conductive Random Access Memory (PCRAM) elements, have been investigated for suitability as semi-volatile and non-volatile random access memory devices. A typical PCRAM device is disclosed in U.S. Pat. No. 6,348,365, assigned to Micron Technology Inc. and incorporated herein by reference. In typical PCRAM devices, conductive material, such as silver, is moved into and out of a chalcogenide material to alter the cell resistance. Thus, the resistance of the chalcogenide material can be programmed to stable higher resistance and lower resistance states. The programmed lower resistance state can remain intact for an indefinite period, typically ranging from hours to weeks, after the voltage potentials are removed.
[0004] One aspect of fabricating PCRAM cells, which may also occur in fabrication of other integrated circuit devices, involves bond pads used for connecting a PCRAM memory device to external leads of an encapsulated integrated circuit package. Increasingly, bond pads are formed of copper, rather than traditional aluminum, due to its superior conductivity and scalability. One drawback associated with copper, however, is that it oxidizes rapidly. Thus, leaving the copper bond pads exposed to die fabrication or packaging process steps where oxygen is present will lead to corrosion of the bond pad. Exposing copper bond pads to subsequent fabrication and/or packaging processes may also cause poisoning of a PCRAM memory cell, because copper ions may migrate from the bond pads and into an underlying chalcogenide glass layer, which changes the responsiveness of the glass to accept or expel other ions used for programming the cell. This, in turn, makes the cell unable to reliably switch between high and low resistance states. Therefore, it is important in the fabrication or packaging of PCRAM cells to limit the cells' copper bond pad exposure and particularly exposure to an oxygen-filled environment. Other integrated circuits using copper bond pads should also avoid exposure of the bond pad to oxidizing environments during subsequent fabrication and/or packaging steps.
[0005] One method for addressing this problem involves back-end processing where nickel is plated onto the copper bond pads after their fabrication. The back-end processing, however, may involve an ion mill etch step, which is a non-selective etching procedure, on the exposed copper. As copper etches at a higher rate than other materials used in fabrication, performing this etch could degrade the copper bond pad completely.
[0006] Accordingly, there is a need for a method of forming PCRAM cells where the PCRAM cell materials are not exposed to copper and the copper bond pads are not oxidized and do not corrode. There is also a more general need to protect copper bond pads from an oxidizing atmosphere during subsequent fabrication steps of integrated circuit devices.
BRIEF SUMMARY OF THE INVENTION
[0007] Exemplary embodiments of the invention provide a front-end method of fabricating nickel plated caps over copper bond pads used in a memory device. The method involves depositing an oxide layer over circuitry formed on a substrate, including array and periphery circuitry. Using a layer of photoresist over the oxide layer, a bond pad pattern is formed and etched in the periphery, exposing a fabricated copper bond pad. The photoresist is removed and nickel is selectively plated onto the exposed copper pad to form a cap over the copper. Following this, fabrication steps may occur which expose the in-fabrication structure to an oxidizing atmosphere without oxidizing the copper bond pads.
[0008] In accordance with one exemplary embodiment, the invention is used to construct bond pads for a PCRAM memory in which PCRAM cell material is deposited and formed into memory cells after the copper bonds are formed and nickel plated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above-discussed and other features and advantages of the invention will be better understood from the following detailed description, which is provided in connection with the accompanying drawings, in which:
[0010] FIG. 1 is a cross-sectional view of an exemplary memory device constructed in accordance with the invention;
[0011] FIG. 2 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication;
[0012] FIG. 3 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication subsequent to that shown in FIG. 2 ;
[0013] FIG. 4 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication subsequent to that shown in FIG. 3 ;
[0014] FIG. 5 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication subsequent to that shown in FIG. 4 ;
[0015] FIG. 6 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication subsequent to that shown in FIG. 5 ;
[0016] FIG. 7 is a cross-sectional view of a portion of the exemplary memory device of FIG. 1 during a stage of fabrication subsequent to that shown in FIG. 6 ;
[0017] FIG. 8 illustrates a computer system having a memory element in accordance with the invention; and
[0018] FIG. 9 illustrates an integrated circuit package having a memory element in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In the following detailed description, reference is made to various specific embodiments of the invention. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other embodiments may be employed, and that various structural, logical and electrical changes may be made without departing from the spirit or scope of the invention.
[0020] The term “substrate” used in the following description may include any supporting structure including, but not limited to, a semiconductor substrate that has an exposed substrate surface. A semiconductor substrate should be understood to include silicon-on-insulator (SOI), silicon-on-sapphire (SOS), doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. When reference is made to a semiconductor substrate or wafer in the following description, previous process steps may have been utilized to form regions or junctions in or over the base semiconductor or foundation. The substrate need not be semiconductor-based, but may be any support structure suitable for supporting an integrated circuit.
[0021] The term “resistance variable material” is intended to include chalcogenide glasses, and chalcogenide glasses comprising a metal, such as silver. For instance the term “resistance variable material” includes silver doped chalcogenide glasses, silver-germanium-selenide glasses, and chalcogenide glass comprising a silver selenide layer.
[0022] The term “resistance variable memory element” is intended to include any memory element, including programmable conductor memory elements, semi-volatile memory elements, and non-volatile memory elements which exhibit a resistance change in response to an applied voltage.
[0023] The term “chalcogenide glass” is intended to include glasses that comprise an element from group VIA (or group 16) of the periodic table. Group VIA elements, also referred to as chalcogens, include sulfur (S), selenium (Se), tellurium (Te), polonium (Po), and oxygen (O).
[0024] The invention is now explained with reference to the figures, which illustrate exemplary embodiments and where like reference numbers indicate like features. FIG. 1 shows array and peripheral circuitry portions of a resistance variable memory element 100 constructed in accordance with the invention. It should be understood that the portions shown are illustrative of one embodiment of the invention, and that the invention encompasses other devices that can be formed using different materials and processes than those described herein. The memory element 100 has copper bond pads 92 in the periphery which are covered with nickel plating 82 . The pads 92 , as discussed below, are constructed such that the memory cell material 69 in the array was not exposed to copper during fabrication of the device 100 . Further, and as described in more detail below, the copper bond pad 92 was not exposed to an oxygen ambient during device 100 fabrication, which could have oxidized the copper and degraded the quality of the bond pad 92 .
[0025] For exemplary purposes only, memory element 100 is shown with an example of the circuitry 50 that the copper bond pads 92 may be used in connection with. In the array and periphery portions of a substrate 200 , transistors 40 are formed having source/drain active regions 101 in the substrate 200 . A first insulating layer 32 , e.g., a boro-phospho-silicate glass (BPSG) layer, is formed over the transistor gatestacks. Conductive plugs 41 , which may be formed of polysilicon, are formed in the first insulating layer 32 connecting to the source drain regions 101 in the substrate 200 . A second insulating layer 34 is formed over the first insulating layer 32 , and may again comprise a BPSG layer. Conductive plugs 49 are formed in the second insulating layer 34 and are electrically connected to the conductive plugs 41 in the first insulating layer 32 which connects through some of plugs 41 to selected transistors 40 . A conductive bit line 55 is formed between the conductive plugs 49 in the second insulating layer 34 . The bit line illustrated has layers X, Y, Z formed of tungsten nitride, tungsten, and silicon nitride, respectively. A third insulating layer 36 is formed over the second insulating layer 34 , and again openings in the insulating layer are formed and filled with a conductive material to form conductive plugs 60 . Next, metallization layers having conductive traces and/or contacts 91 are formed over the third insulating layer 36 and are insulated with an interlevel dielectric (ILD) layer 38 .
[0026] Referring now to FIGS. 2-7 , an exemplary method of forming the bond pads 92 for memory element 100 in accordance with the invention is now described. It should be understood that the description of materials and fabrication steps just described for circuitry 50 were illustrative only, and that other types of integrated circuitry is within the scope of the invention. Thus, for purposes of the remaining fabrication steps, the layers of the circuitry 50 are not depicted in the fabrication steps described with reference to FIGS. 2-7 .
[0027] Turning to FIG. 2 , an inter level dielectric (ILD) layer 40 is formed. In this layer 40 in the periphery, a dual damascene pattern is formed and filled with copper to create a copper connection 61 and a copper bond pad 92 . In both the array and the periphery, an oxide layer 56 and a nitride layer 57 are then deposited over the ILD layer 40 . Vias 62 are formed through layers 56 , 57 and the ILD layer 40 and filled with a conductive material to connect with conductive areas of the circuitry 50 below (such as contacts 91 of FIG. 1 ). The vias 62 are filled with a conductive material, such as tungsten, and the vias 62 are either dry etched or chemical mechanical polished (CMP) to planarize the top of the vias 62 even with the nitride layer 57 . Thus, at this stage, tungsten is exposed at the top of the vias 62 and the copper bond pad is covered with oxide layer 56 and nitride layer 57 .
[0028] Next, referring to FIG. 3 , an oxide layer 63 is formed over the tops of the vias 62 and the nitride layer 57 . The oxide layer 63 is preferably thin, approximately 100 to about 500 Angstroms thick over both the array and the periphery. A layer of photoresist 64 is formed over the oxide layer 63 . As shown in FIG. 3 , a bond pad pattern is formed over pad 92 by patterning and developing the photoresist 64 , and as shown in FIG. 4 , the opening is used to etch oxide layer 63 , nitride layer 57 , and oxide layer 56 down to the bond pad 92 . After etching, the photoresist 64 is stripped from the wafer.
[0029] At this stage in fabrication, in the area of the periphery where the bond pad is patterned, the exposed copper 92 will oxidize slightly, however, so long as the this step is not prolonged, the oxidation will enable the next formation step. As shown in FIG. 5 , nickel is plated selectively onto the copper bond pad 92 , forming a nickel cap 82 . The nickel plating may be accomplished by an electroless nickel bath. For example, without limiting the plating chemistry that may be utilized for this invention, the copper bond pad 92 is exposed to a plating nickel bath having a pH value of approximately 8. The nickel bath may comprise a nickel salt and a reducing agent as well as a stabilizing agent. The temperature of the bath may be approximately 80 degrees Celsius or less, depending on the rate of deposition desired. A lower temperature improves the uniformity of deposition while a higher temperature increases the plating rate. The nickel cap may be approximately 4000 Angstroms thick. Post-plating, the remaining oxide layer 63 is wet etched off, leaving the tungsten vias 62 exposed.
[0030] Memory cell formation and patterning can now occur. As shown in FIG. 6 , cell material 69 is deposited on the array. The cell material 69 may include resistance variable cell material, like the materials necessary for construction of PCRAM memory cells constructed according to the teachings of U.S. Pub. application Nos. 2003/0155589 and 2003/0045054, each assigned to Micron Technology Inc. Appropriate PCRAM cell materials include layers of germanium selenide, chalcogenide glass, and silver-containing layers creating a resistance variable memory device 100 . Finally, a top electrode 70 is deposited over the cell material 69 as shown in FIG. 7 . The top electrode 70 contacts the cell 69 and the periphery vias 62 . The electrode 70 can be patterned as desired. For example, the electrode 70 layer may be blanket deposited over the array; or alternatively, an electrode 70 may be deposited in a pre-determined pattern, such as in stripes over the array. In the case of PCRAM cells, the top electrode 70 should be a conductive material, such as tungsten or tantalum, but preferably not containing silver. Also, the top electrode 70 may comprise more than one layer of conductive material if desired.
[0031] At this stage, the memory element 100 is essentially complete. The memory cells are defined by the areas of layer 69 located between the conductive plugs 62 and the electrode 70 . Other fabrication steps to insulate the electrode 70 using techniques known in the art, are now performed to complete fabrication.
[0032] FIG. 9 illustrates that the memory element 100 is subsequently used to form an integrated circuit package 201 for a memory circuit 1248 ( FIG. 8 ). The memory device 100 is physically mounted on a mounting substrate 202 using a suitable attachment material. Bond wires 203 are used to provide electrical connection between the integrated chip bond pads 92 and the mounting substrate bond pads 204 and/or lead wires which connect the die 100 to circuitry external of package 201 .
[0033] The embodiments described above refer to the formation of a memory device 100 structure in accordance with the invention. It must be understood, however, that the invention contemplates the formation of other integrated circuit elements, and the invention is not limited to the embodiments described above. Moreover, although described as a single memory device 100 , the device 100 can be fabricated as a part of a memory array and operated with memory element access circuits.
[0034] FIG. 8 is a block diagram of a processor-based system 1200 , which includes a memory circuit 1248 , for example a PCRAM circuit employing non-volatile memory devices 100 fabricated in accordance with the invention. The processor system 1200 , such as a computer system, generally comprises a central processing unit (CPU) 1244 , such as a microprocessor, a digital signal processor, or other programmable digital logic devices, which communicates with an input/output (I/O) device 1246 over a bus 1252 . The memory 1248 communicates with the system over bus 1252 typically through a memory controller.
[0035] In the case of a computer system, the processor system may include peripheral devices such as a floppy disk drive 1254 and a compact disc (CD) ROM drive 1256 , which also communicate with CPU 1244 over the bus 1252 . Memory 1248 is preferably constructed as an integrated circuit, which includes one or more resistance variable memory elements 100 . If desired, the memory 1248 may be combined with the processor, for example CPU 1244 , in a single integrated circuit.
[0036] The above description and drawings are only to be considered illustrative of exemplary embodiments which achieve the features and advantages of the invention. Modification and substitutions to specific process conditions and structures can be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be considered as being limited by the foregoing description and drawings, but is only limited by the scope of the appended claims.
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A front-end method of fabricating nickel plated caps over copper bond pads used in a memory device. The method provides protection of the bond pads from an oxidizing atmosphere without exposing sensitive structures in the memory device to the copper during fabrication.
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This application is a Divisional of U.S. patent application Ser. No. 10/633,663 filed on Aug. 5, 2003, which is a continuation of PCT Application Number PCT/EP01/11151 filed on Sep. 26, 2001, which claims priority from German application number 101 05 055.0 filed on Feb. 5, 2001; which are all incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates, according to a first aspect, to a ground covering element of artificial stone material, having a basic shape corresponding to a unification of several square basic elements, in particular an angular ground covering element, the ground covering element comprising projections and recesses all around its circumference, all circumferential basic element sides—as seen from the center of the respective basic element upper side—having substantially the same profile which is substantially point-symmetric with respect its halving point.
2. Description of the Prior Art
Basic elements of this kind, also angular ground covering elements, are known. So far, the design of the profile has been based more or less on intuition.
It is an object of the invention to purposefully design the profile in order to obtain a good compromise between inter-engagement effect in case of not completely perfect mutual orientation of adjacent ground covering elements and strength of the inter-engagement between adjacent ground covering elements.
SUMMARY OF THE INVENTION
To meet this object, the aforementioned ground covering element is characterized in that this profile consists of three projections and three recesses. It will be elucidated in more detail further below that this number will result in an optimum compromise in the sense of the underlying object mentioned.
The afore-mentioned “artificial stone material” in most cases is concrete. As a further preferred possibility, brick-like materials should be mentioned. In general, there are also all materials conceivable having embedded therein additives or fillers in binders (e.g. also plastics) hardening as a function of time, in particular polymer concrete. The word “substantially” was used with consideration, since in most cases, the profile is not equal on all circumferential basic element sides in the strict sense and since the point symmetry is not realized in the strict sense in most cases. Ground covering elements of artificial stone material are manufactured with such large manufacturing tolerances that this is of itself sufficient to prevent the manufacture of exactly identical profiles and exact point symmetry. In addition thereto, it happens quite often that minor changes in dimension are purposefully made on specific locations of the ground covering element, e.g. for taking into account e.g. a slanted corner or a retraction of a circumferential portion in order to create free space for a laying gap, so that the term “substantially” makes sense under this aspect. Finally, it may be reasonable to make e.g. the projections slightly narrower (as measured in the direction of extension of the basic element side) than the recesses, which are complementary in engagement, in order to thus provide a laying gap between adjacently laid ground covering elements. Quite analogous aspects are applicable as regards the use of the term “substantially” in the following description and in the entirety of the claims.
One could also say, in other words, that the profiles at the circumferential basic element sides of the ground covering element are designed such that a particular profile considered may be placed adjacent a substantially identical profile after rotation by 180° so as to provide complementary inter-engagement.
The claims as well as the description of the present patent specification, at numerous locations thereof, make statements on geometric relationships, e.g. “square basic element”, “angular ground covering element”, “projection”, “recess”, “profile”, “wide”, “trapezoidal”. All of these statements relate to a representation of the ground covering element in a plan view, i.e. a view from above onto the useful or upper side of the respective ground covering element, as if the same were laid on a base, unless otherwise expressly stated at the particular location. The ground covering element according to the invention preferably is a ground covering element provided to make ground coverings for “outdoor use” or for laying areas in the outside. A particularly preferred field of use of the ground covering element according to the invention is for traffic areas, in particular such areas outdoors, e.g. areas for motor vehicle traffic, areas for bicycle traffic, areas for pedestrian traffic. Particularly typical and preferred are squares, yards, drives, paths, roads, pedestrian areas, loading areas, terraces, parking areas for vehicles, filling stations, commercial traffic areas, industrial traffic areas, factory yards, container sites.
Preferably, the projections and recesses are trapezoidal, which can be manufactured easily and is favorable for the shear strength of the projections. As an alternative it is preferred that the projections and recesses are confined each by a line rounded at least in part, e.g. semi-circular with rounded transition to the left and to the right. It is to be noted generally that the geometric design of the projections and recesses offers a large variety of possibilities.
Preferably, the middle projection and the middle recess each are considerably wider than the other projections and recesses, respectively. In this regard, at least 1.5 times as wide is particularly preferred, at least 1.8 times as wide is still further preferred, and at least 2.0 times as wide is even further preferred. It will become clearer by more detailed statements further below why this difference in dimensions will result in a still further improved compromise in the sense of the solution of the object.
Preferably, the ground covering element is provided with spacer projections on its circumference, with these spacer projections being left disregarded in the consideration of the geometric relationships discussed in the claims. However, it is pointed out that there are also designs in which the geometric relationships mentioned in the claims are maintained despite the spacer projections. Due to the spacer projections, ground covering elements are obtained that can be laid in particularly expedient manner with the laying gap width remaining the same (as measured transversely of the general direction of extension of the circumferential basic element side).
According to a second aspect, the invention relates to a ground covering element of artificial stone material, having a basic shape corresponding to a unification of several square basic elements, in particular an angular ground covering element, the ground covering element comprising projections and recesses all around the circumference and comprising retractions on the circumference which result in efficient water passage openings in a group of the adjacently laid ground covering elements,
characterized in that the projections and recesses in their entirety are defined by one profile each for each circumferential basic element side, there being provided
(a) on zero to all circumferential basic element sides, substantially a first profile each, having—as seen from the center of the particular basic element upper side—a first end neighboring projection, a second end neighboring projection and an end distance projection there-between;
(b) on zero to part of the circumferential basic element sides, substantially a second profile each, having—as seen from the of the particular basic element upper side—a first end neighboring projection and a second end neighboring projection;
(c) and on zero to part of the circumferential basic element sides, substantially a third profile each, having—as seen from the center of the particular basic element upper side—an end distance projection and an end neighboring projection;
(d) wherein, for laying a group of the ground covering elements adjacent each other,
a first profile, if provided, can be applied to a first profile, if provided, of a neighboring ground covering element; or can be applied to a second profile, if provided, of a neighboring ground covering element; or can be applied to a third profile, if provided, of a neighboring ground covering element;
a second profile, if provided, can be applied to a second profile, if provided, of a neighboring ground covering element; or can be applied to a third profile, if provided, of a neighboring ground covering element,
and a third profile, if provided, can be applied to a third profile, if provided, of a neighboring ground covering element.
Ground covering elements of this type according to the invention, in the state laid adjacent each other, thus lead to ground coverings in which efficient water passage openings are present in a very considerable part of the ground covering element circumferences. However, due to this, the ground covering elements mostly lose the feature “the profile is substantially point-symmetric with respect to its halving point”.
All statements made so far in the description, of course with the exception of statements that are contradictory to the second aspect of the invention, apply analogously also for ground covering elements according to the second aspect of the invention, inclusive of the preferred developments thereof.
It is emphasized that the terms “first end neighboring projection” and “second end neighboring projection” do not mean that the projection concerned begins immediately at an end of the respective circumferential basic element side. There may be a distance provided. Rather, what is to be expressed is that the respective projection is positioned not very far from the respective end and in particular that there is no additional projection present between the end neighboring projection and the end proper. The first end does not necessarily have to be the left-hand end of a particular profile, but may optionally be the left-hand end or the right-hand end of the particular profile.
As in case of the ground covering element according to the first aspect of the invention, the projections and recesses preferably are trapezoidal, and as an alternative are preferably confined by a line that is rounded at least in part. The statements made further above are applicable here as well.
Preferably, the retractions are trapezoidal, as an alternative preferably confined at least in part by a rounded line. The statements made hereinbefore in connection with the shape of the projections and recesses apply analogously for the retractions as well.
The embodiments described herein provide further details of the first, second and third profiles.
With respect to the first profile and/or the second profile and/or the third profile, the retraction in each thereof is preferably at least 33% of the width of the respective circumferential basic element side, more preferably at least 40% of the width, still more preferably at least 50% of the width. In the second profile, it is easier to obtain a maximum possible width of the retraction than in case of the first and third profiles.
Preferably, the particular retraction at least in part is retracted or taken back further towards the interior of the ground covering element than the recesses or recesses of the particular basic element side. The wider the respective retraction and the “deeper” the retraction is taken back, the higher the percentage of the sum of the cross-sectional areas of the water penetration passages in relation to the size of the covering in total.
The present disclosure further defines preferred combinations of first profiles, second profiles and third profiles on the circumference of the ground covering element. More detailed information in this regard will be given by the embodiments further below.
As regards the ground covering element according to the first aspect of the invention, it is indeed preferred that the first projection, the first recess, the third projection and the third recess all have substantially the same width (as measured in the direction of the circumferential basic element side). However, it is possible as well to provide just the first projection and the third recess with substantially the same width and to provide just the first recess and the third projection with substantially the same width (which, however, is narrower or wider than the width of the afore-mentioned “pair”).
As with the ground covering element according to the first aspect of the invention, the ground covering element according to the second aspect of the invention preferably may have spacer projections and/or at least one dummy gap.
According to a third aspect, the invention relates to a set of ground covering elements, containing a ground covering element according to the first aspect of the invention (first ground covering element) and a ground covering element according to the second aspect of the invention (second ground covering element) wherein, for laying a first ground covering element and a second ground covering element adjacent each other, the basic side profile of the first ground covering element can be laid adjacent a first profile or a second profile or a third profile of an adjacent second ground covering element.
The invention thus provides a set of ground covering elements, in which first ground covering elements and second ground covering elements can be laid adjacent each other in an arbitrary mutual orientation. This property comes to bear in particularly advantageous manner either at the boundary between a first part of a covering laid with first ground covering elements and a second part of the covering laid with second ground covering elements or—which is possible without any problem—in a covering with a regular alternation between a first ground covering element and a second ground covering element.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and preferred developments of the invention will be described in more detail hereinafter by way of embodiments shown in the drawings in which
FIG. 1 shows an angular ground covering element;
FIG. 2 a to 2 d each show the abutment portion of two adjacent ground covering elements in a fragmentary view;
FIG. 3 shows a second embodiment of a ground covering element that is modified over that of FIG. 1 , with partial regions being broken away;
FIG. 4 shows a portion of a circumference of a ground covering element;
FIG. 5 shows a portion of a circumference of a ground covering element;
FIG. 6 shows a portion of a circumference of a ground covering element;
FIG. 7 shows an angular ground covering element according to a third embodiment;
FIG. 8 shows a fourth embodiment of a ground covering element that is modified over that of FIG. 7 , with partial regions being broken away;
FIG. 9 shows an angular ground covering elements according to a fifth embodiment;
FIG. 10 shows a sixth embodiment of a ground covering element that is modified over that of FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
All of the drawing figures are plan views.
FIG. 1 shows an angular ground covering element 2 . In the following, the term “covering element” will be used throughout in the following instead of “ground covering element” for reasons of brevity. All covering elements shown preferably consist of concrete.
The configuration of the covering element 2 is conceivable easiest if one first speaks of a “basic shape”. In case of the covering element 2 of FIG. 1 , this basic shape is constituted by the unification of three square basic elements 4 , 6 , 8 . The junction lines 10 of the three basic elements 4 , 6 , 8 are illustrated in broken lines 10 . Basic element 4 thus has three circumferential basic element sides 12 , basic element 6 has two circumferential basic element sides 12 , and basic element 8 has three circumferential basic element sides 12 . In basic element 8 , the three circumferential basic element sides 12 are illustrated in broken lines. When looking at the combination of these three circumferential basic element sides and the junction line 10 belonging to basic element 8 , the basic element square will become apparent immediately.
Basic element 8 shall be considered in more detail in the following:
On each of the three circumferential basic element sides 12 , there is provided a profile 14 composed of projections 16 and recesses 18 . The respective circumferential basic element side 12 at the same time represents a neutral line with respect to which the projections 16 are projecting outwardly and with respect to which the recesses 18 are receding inwardly.
To begin with, the in FIG. 1 upper, in total horizontally extending profile 14 of basic element 8 shall be considered. Starting from the left-hand end of the basis element side 12 considered, the profile 14 begins with a projection 16 a , followed by a recess 18 a , then a projection 16 b , thereafter a recess 18 b , then a projection 16 c and thereafter a recess 18 c extending up to the right-hand end of basic element side 12 . All projections 16 a to c and all recesses 18 a to c are of trapezoidal shape, i.e. they begin with a slightly wider base on the straight basic element side 12 and taper towards the free end and towards the base, respectively. The projections 16 and recesses 18 follow each other without a gap. The projections 16 a and 16 c closer to the ends of basic element side 12 (in other embodiments described hereinafter, reference will be made to “end neighboring projection”) and the recesses 18 a and 18 c closer to the ends of basic element side 12 all have substantially the same mutual width (measured on the basic element side 12 =neutral line). The projection 16 b remoter from the ends of basic element side 12 as well as the recess 18 b remoter from the ends of basic element side 12 have the same mutual width and each are about twice as wide as any of the projections 16 a and 16 c and any of the recesses 18 a and 18 c , respectively. The terms “substantially” and “about” have been used purposefully, since—for reasons to be elucidated in more detail further below—the measurement relationships mentioned are not to be understood as being exactly so. For example, projection 16 a indeed is somewhat wider than projection 16 c . On the other hand, recess 18 c indeed is somewhat wider than recess 18 a ; moreover, the corner of covering element 2 is slanted with a small taper at the right-hand end of recess 18 c . Finally, it is pointed out that in case of concrete products, like the covering element 2 illustrated, indications of measurements and measurement relationships are not to be understood as being exact anyway due to the tolerances of the manufacturing mold and due to the material providing no particularly smooth areas. A particularly relevant aspect resulting in a variation in width among projections 16 and recesses 18 is the fact that on the circumferential sides of covering element 2 , where a neighboring covering element is adjoining when several covering elements 2 are laid adjacent each other, a laying gap e.g. of a width of 3 to 5 mm is maintained, whereas there is no laying gap on junction line 10 . To provide for certain compensation in this respect, the more or less mathematical initial design of the profile 14 with respect to the width of the projections 16 and the recesses 18 and with respect to the positioning of the projections 16 and recesses 18 is slightly modified.
The profile 14 in consideration is substantially point-symmetric with respect to its halving point 20 , i.e. when the left-hand profile half is rotated by 180° in the drawing plane of FIG. 1 , it is identical with the right-hand profile half. The term “substantially” was inserted for the reasons analogous to those set forth hereinbefore.
It is emphasized that the profile 14 described could also be formed “inversely”, i.e. folded by 180° about a halving line located in the drawing plane, i.e. left-hand end and right-hand end are interchanged. Profile 14 then would begin with a first recess on the left-hand side.
The afore-mentioned widths of the projections 16 and recesses 18 are measured on the neutral line 12 . This is as a rule the most appropriate place of the covering element 2 according to the invention.
It is pointed out that the trapezoidal shape of the projections 16 and recesses 18 constitutes just one of numerous embodiments possible. Instead of this, one could choose e.g. a rectangular shape (which however is more difficult to produce) or a farther projecting or farther receding shape e.g. in the form of a low triangle. The profile 14 , as seen from the center 22 of the particular basic element, is the same on each of the three circumferential basic element sides 12 , i.e. when the upper profile 14 considered first is rotated clockwise by 90° about the center 22 , it merges substantially with the in FIG. 1 right-hand profile 14 extending in its entirety in vertical direction, and when the upper profile 14 is rotated by 180° about the center 22 , it merges substantially with the in FIG. 1 lower profile 14 of the particular basic element 8 , extending in its entirety in horizontal direction. As regards the use of the term “substantially”, it is referred to the statements made hereinbefore. Due to the afore-mentioned point symmetry of each profile 14 with regard to the halving point 20 , the lower profile 14 is substantially a parallel shift of the upper profile 14 .
All statements made hereinbefore with respect to the profiles 14 apply analogously to the basic elements 4 and 6 , with the basic element 6 of course having only two circumferential basic element sides and thus only two profiles 14 extending so to speak perpendicularly with respect to each other.
The geometry of the profiles 14 described allows adjacent covering elements to be placed adjacent the covering element 2 illustrated in FIG. 1 , either in the same orientation or in an orientation rotated by 90° (clockwise or anticlockwise) or an orientation rotated by 180°. The profiles 14 of adjacent covering elements 2 always fit together in complementary manner (with some “air” there-between); there is mutual engagement or anchoring of the adjacent covering elements 2 in addition to the mutual anchoring of adjacent covering elements in the laid state that is obtained by the angular configuration of the covering element 2 illustrated.
It is pointed out that covering elements 2 according to the invention indeed are supposed to have a basic shape corresponding to a unification of several square basic elements, but that the number of the basic elements and the orientation of the unification can be chosen. For example, it would be possible to unify e.g. three basic elements 4 , 6 , 8 (or also two basic elements or four basic elements) in a straight series, or to provide an L-shaped covering element 2 by addition of a further basic element on the right-hand side of basic element 8 , or to provide a T-shaped covering element 2 by addition of a further basic element to the upper side of the middle basic element 6 , or to provide a cruciform covering element 2 by addition of a further basic element to the upper side of the middle basic element 6 and addition of a further basic element to the left-hand side of the middle basic element 6 , etc.
It is expressly emphasized that the invention, as an alternative, also provides a ground covering element whose basic shape consists of one square basic element only, but otherwise has the cogent features described in the present patent specification and optionally further preferred features.
It is illustrated by way of FIGS. 2 a to d why the number of “three projections” and “three recesses” according to the invention provides for especially good results. Each of the partial figures a to d schematically illustrates a profile 14 of a circumferential basic element side 12 . In FIG. 2 a , the basic element side is divided into eight projections 16 and eight recesses 18 which all have the same mutual width. In partial FIG. 2 b , the basic element side is divided into three projections 16 and three recesses 18 which all have the same mutual width. In partial FIG. 2 c , the basic element side is divided into two projections 16 and two recesses 18 which all have the same mutual width. The alternative with just one projection and one recess is not illustrated as it results in incomplete inter-engagement between two covering elements.
Each of the basic element sides 12 of the two adjacent covering elements 2 a and 2 b do not extend parallel to each other (as desired for perfect laying), but extend at an angle 24 with respect to each other, with angle 24 being the same in all partial FIGS. 2 a to d.
If two adjacent covering elements 2 a and 2 b are arranged beside each other with a misalignment in the sense of the angle 24 mentioned, which may occur due to inaccurate laying work or by displacement of individual covering elements 2 by traffic loads in the laid state, FIG. 2 a still maintains a residual inter-engagement by the last projection 16 at the right-hand end of basic element side 12 of the one covering element 2 a and a recess 18 at the corresponding end of the basic element side 12 of the other covering element 2 b . In case of the covering elements 2 a and 2 b of FIG. 2 b , the left hand trapezoidal side of the rightmost projection 16 c of covering element 2 a and the left-hand trapezoidal side of the rightmost recess 18 c of covering element 2 b have migrated a certain distance to the left, but in this situation there is just left a residual inter-engagement between this projection 16 c and this recess 18 c (although with lesser depth of positive engagement). In case of the covering elements 2 a and 2 b according to FIG. 2 c , there is no residual inter-engagement left in this situation. The conclusion to be drawn therefrom is that the residual inter-engagement effect in case of angular misalignment between adjacent covering elements is the better the larger the number of projections and recesses over a given length of a basic element side.
A further aspect is the strength or load-bearing capacity of the inter-engagement between two adjacently laid covering elements 2 a and 2 b in the correctly laid state, i.e. with mutually parallel basic element sides 12 with so little spacing from each other as corresponds to the usual laying gap. In this respect, the shear strength, i.e. the covering elements 2 a and 2 b have forces of opposite directions applied thereto in the direction parallel to the basic element sides 12 , decreases with increasing number of projections 16 and recesses 18 on a given length of the basic element side 12 . On the one hand, the overall shear area summed up from the individual projections 16 becomes ever smaller with increasing number of projections (since the laying gap sections between the oblique trapezoidal sides do not contribute in the overall shear area and since a loss in overall shear area is caused in that, on a larger number of projections, the cross-sectional area of shear is not located in the root of the projection, but in the projection portion that is tapered in comparison therewith). On the other hand, there is the effect that, with a larger number of projections, it is by far not the entire number of projections that provides a supporting effect against shearing, but less than half thereof in accordance with experience. The aspect of shear strength thus speaks for making the number of projections and recesses as small as possible for a given length of the basic element side.
On consideration of these aspects, the inventors thus have arrived at the conclusion that the number of three projections and three recesses represents the optimum compromise between residual inter-engagement effect in case of angular misalignment and high shear strength.
This compromise is still further enhanced when the pairs of projection 16 a and recess 18 a and projection 16 c and recess 18 c closer to the respective ends of the basic element side are of lesser width than the pair of projection 16 b and recess 18 b arranged there-between, cf. FIG. 2 d.
The embodiment of a covering element 2 according to FIG. 3 differs from the embodiment according to FIG. 1 in that straight dummy gaps 26 extend at those locations where the junction lines 10 were illustrated in FIG. 1 . Dummy gaps are gaps extending from the upper side downwardly into covering element 2 up to a specific depth of e.g. 5 mm only. The dummy gaps 26 provide for an optical subdivision of covering element 2 into three partial covering elements which, apart from the profiles 14 , correspond to the three basic elements 4 , 6 , 8 . As measured transversely of their direction of extension, the dummy gaps 26 have a width corresponding substantially to the height of the projections 16 , as measured from the bottom of the recesses 18 and, in addition, the afore-mentioned laying gap width (the latter being measured transversely to the general direction of extension of profile 14 ). It is possible not only with the embodiment according to FIG. 3 , but with all embodiments that the upper sides of the projections 16 are slightly lowered with respect to the remaining upper side of covering element 2 , e.g. by 4 to 8 mm. The consequence hereof is that the inter-engagement between two adjacent profiles 14 is optically less apparent in the laid covering of several covering elements 2 . The dummy gaps 26 so to speak represent an optical continuation of the groove formed by the two adjacent profiles 14 and the laying gap there-between.
Moreover, FIG. 3 illustrates the possibility of providing spacer projections 28 distributed over the circumference of the covering element 2 . In the illustrated embodiment, the spacer projections 28 are of semi-circular cross-section each and are provided on the—as seen from the center 22 of the respective basic element upper side—leftmost projection 16 of the corresponding profile 14 each. In FIG. 3 , the size of the spacer projections 28 is shown in enlarged form as compared to their natural size in order to make the spacer projections clearly visible at all. The spacer projections 28 facilitate laying of the covering elements 2 , since the adjacent covering element 2 to be laid next can be placed simply in physical contact between the spacer projections 28 of the already laid covering element 2 and the spacer projections 28 of the new covering element 2 to be laid. In this manner, a laying gap of uniform width is created. It is emphasized that the spacer projections may be selectively of other cross-sectional geometry and be located on other locations than those shown in FIG. 3 . It is preferred that the spacer projections begin only a certain distance below the covering element upper side and extend from there to the very bottom side of the covering element 2 . The spacer projections 28 are formed integrally with the remainder of the covering element 2 of concrete.
FIG. 3 finally illustrates the possibility of confining the projections 16 and the recesses 18 by a rounded line each (rounded throughout or rounded in portions and straight in portions).
It is emphasized furthermore that the features “dummy gaps 26 ” and “spacer projections 28 ” need not necessarily be realized in combination, but that it is possible to provide covering elements 2 with at least one dummy gap 26 and/or with spacer projections 28 . It is possible to provide just one dummy gap 26 or more than two dummy gaps 26 , e.g. to optically subdivide the unification of the basic elements 6 and 8 into three parts by means of two dummy gaps 26 . It is possible, furthermore, to provide one or more non-linear dummy gaps, extending e.g. in conformity with the path of profile 14 .
FIGS. 4 to 6 illustrate profiles 14 a , 14 b , 14 c that are modified with respect to profile 14 of FIG. 1 . Here too, the neutral line 12 is shown in each of the figures. The distance from the respective left-hand end to the respective right-hand end corresponds to that of a basic element side in FIG. 1 .
The profile illustrated in FIG. 4 is a profile of the type referred to as “first profile 14 a ” in the present text. In comparison with the profile 14 of FIG. 1 (e.g., considering the “horizontal” profile 14 to the upper right in FIG. 1 ), the second projection 16 b is rendered narrower to such an extent that it has a width (as measured in the direction of the neutral line 12 ) corresponding to the width of third projection 16 c . Between the thus formed second projection 16 b and the third projection 16 c , there is located a retraction 30 . Retraction 30 is further retracted towards the interior of covering element 2 than the bottom of recess 18 a and the bottom of recess 18 c . Retraction 30 in total is of trapezoidal shape. In the introductory part of the specification, first projection 16 a is designated “first end neighboring projection” (as it is located in the neighborhood of the first end of the profile), second projection 16 b is designated “end distance projection” (as, in comparison with the other projections, it is arranged at a larger distance from the ends of the profile), and third projection 16 c is designated “second end neighboring projection” (as it is located in the neighborhood of another end of the profile).
The profile illustrated in FIG. 5 is a profile of the type referred to as “second profile 14 b ” in the present text. In comparison with the profile 14 of FIG. 1 (e.g. considering the “horizontal” profile 14 to the upper right in FIG. 1 ), the second projection is omitted completely so that of the projections only the first end neighboring projection 16 a and the second end neighboring projection 16 c are left. Between these projections 16 a and 16 b , there is located a retraction 30 (which thus replaces first recess 18 a , second projection 16 b and second recess 18 b ) which, as in case of FIG. 4 , is retracted further towards the interior of covering element 2 than the bottom of recess 18 c.
The profile illustrated in FIG. 6 is a profile of the type referred to as “third profile 14 c ” in the present text. In comparison with the profile 14 of FIG. 1 (e.g. considering the “horizontal” profile 14 to the upper right in FIG. 1 ), the first projection 16 is omitted and substituted by a corresponding broadening of the first recess 18 a . The second projection 16 b of FIG. 1 is rendered narrower to the same extent as in case of profile 14 a in FIG. 4 . The retraction 30 in FIG. 5 also corresponds to the retraction 30 in FIG. 4 . In the description, projection 16 b is designated “end distance projection” (since, in the light of the just outlined history of origin, it corresponds to the end distance projection 16 b in FIG. 4 and although there is no further projection between it and the left-hand end of the profile 14 c ). It is emphasized that the profiles 14 a , 14 b , 14 c as an alternative may also be designed such that they are folded by 180° about their halving axis located in the drawing plane, so that they would each begin with recess 18 c at the left-hand end.
In the first profile 14 a of FIG. 4 , the projections 16 a , 16 b , 16 c all have substantially the same width (as measured in the direction of the neutral line 12 ); the recesses 18 a and 18 c also have substantially the same mutual width and substantially the same width as the projections (as measured in the direction of neutral line 12 ). As regards the reasons for using the term “substantially”, these have already been pointed out hereinbefore in connection with FIG. 1 . In particular, one can see in FIG. 4 that the first end neighboring projection 16 a in reality is somewhat wider than the projections 16 b and 16 c . It is expressly pointed out that the end distance projection 16 b could very well be wider towards the right than is illustrated, without this interfering with the inter-engagement with a neighboring covering element 2 to be discussed in more detail further below.
As regards the second profile 14 b of FIG. 5 , the two projections 16 a and 16 c and the recess 18 c all have substantially the same width.
In the third profile 14 c of FIG. 6 , the projections 16 b and 16 c and the recess 18 c are substantially of the same width; the recess 18 a is substantially twice as wide as in FIG. 1 . Here, too, the end distance projection 16 b indeed could be wider towards the right without this interfering with the inter-engagement.
A comparison of FIGS. 4 , 5 , 6 directly reveals that the first profile 14 a (of course upon rotation thereof by 180°) could be laid selectively adjacent an additional first profile 14 a or a second profile 14 b or a third profile 14 c . The second profile 14 b , too, can be laid selectively adjacent a first profile 14 a , a second profile 14 b and a third profile 14 c . The third profile 14 c also is adapted to be selectively laid adjacent a first profile 14 a or a second profile 14 b or a third profile 14 c . This becomes clear also from the history of origin of profiles 14 a , 14 b , 14 c since, as compared to the profile 14 of FIG. 1 , projections have been cut off completely or in part, while however no essential changes have been made, with the exception of the retractions 30 . It is recognizable furthermore that, with respect to the retractions 30 (in so far as they are not reduced in a small part by projections 16 of the neighboring covering element 2 engaging therein), there are left elongate openings in the covering of a plurality of adjacently laid covering elements 2 . These openings represent efficient water passage openings through which water precipitated may flow off into the bed underneath the covering, so that it need not be discharged into a discharge channel system. The depth of the retractions 30 with respect to the neutral line 12 determine—in addition to the width of the retractions 30 , though this cannot be chosen very freely—the percentage of the water passage openings in the total covering. The purpose of the described change from the profile 14 of FIG. 1 to the profiles of FIGS. 4 to 6 consisted in providing covering elements 2 which in the laid state form water penetration passages in the covering.
If a second profile 14 b is laid in inter-engagement with a second profile 14 b , an inter-engagement is established that provides for positive locking in just one of two possible directions. The same holds if a third profile 14 c is laid in inter-engagement with a third profile 14 c . However, if a first profile 14 a is laid in inter-engagement with a first profile 14 a , positive locking in the two directions possible is achieved (since projection 16 c engages in recess 18 a framed on both sides by projections). The same holds for inter-engagement between a first profile 14 a and a second profile 14 b as well as for inter-engagement between a first profile 14 a and a third profile 14 c . Also with inter-engagement of a second profile 14 b and a third profile 14 d , there is a positive locking effect achieved in the two directions possible, i.e. towards the left and towards the right in FIGS. 4 , 5 , 6 . The result of this is that covering elements 2 having only second profiles 14 b all around their circumference and covering elements 2 having only third profiles 14 c all around their circumference are not particularly advantageous under the aspect of inter-engagement on each circumferential basic element side. However, this aspect is not of extremely large significance especially with angular covering elements 2 as shown in FIG. 1 , since the overall configuration of the covering element 2 already results in effective mutual anchoring of the covering elements 2 in the covering.
Good inter-engagement and/or good anchoring due to the covering element configuration is advantageous not only for the laid state but also for holding together of covering elements manufactured together on a plate of the manufacturing machine, when these are machine-laid using a gripper.
It has already been pointed out hereinbefore that it is basically possible to make covering elements 2 for providing coverings with efficient water passage openings which, at the circumference thereof, have either only first profiles 14 a or only second profiles 14 b (better, however, with at least one exception) or only third profiles 14 c (better, however, with at least one exception) or an arbitrary combination of profiles 14 a , 14 b , 14 c.
FIG. 7 illustrates an embodiment of a water passage opening covering element 2 which has no first profile 14 a , but five second profiles 14 b and three third profiles 14 c . As regards the locations of such second profiles 14 b and such third profiles 14 c , it is expressly referred to FIG. 7 .
FIG. 8 illustrates schematically (i.e. without explicit indication of the profiles) a modification in which four second profiles 14 b and four third profiles 14 c are provided, with these being distributed moreover in different manner along the circumferential basic element sides 12 . As regards the distribution thereof over the circumferential basic element sides 12 , it is expressly referred to FIG. 8 .
FIG. 9 shows an embodiment having two first profiles 14 a , five second profiles 14 b and a third profile 14 c . As regards the individual circumferential basic element sides with the individual profiles, it is expressly referred to FIG. 9 . The transition from the embodiment of FIG. 7 to the embodiment of FIG. 9 is conceivable such that two third profiles 14 c have been replaced by two first profiles 14 a.
Analogous with FIG. 3 , FIG. 10 shows an embodiment in which the additional features “dummy gaps 26 ”, “spacer projections 26 ” and “rounded projections 16 ” or “rounded recesses 18 ” or “rounded retraction 30 ”, respectively, can be seen. Here too, the detailed statements made hereinbefore in relation to FIG. 3 hold in particular with respect to the non-existing cogent requirement of providing several of these features in combination.
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The invention relates to an artificial stone floor element with a basic shape that corresponds to the combination of a plurality of square basic elements, especially to an angular floor element. The floor element includes projections and recesses along its peripheral sides of the basic element when seen from the centre of the respective top face of the basic element is substantially point-symmetric with respect to its mid-point. The floor element in further embodiments includes a profile that consists of three projections and three recesses.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to solid oxide cells (SOCs) in which the formation of degradation products is reduced. More specifically the invention concerns solid oxide fuel cells and solid oxide electrolysis cells in which degradation of oxygen electrodes comprising lanthanum-strontium-manganite (LSM) is inhibited.
[0003] 2. Description of the Related Art
[0004] Solid oxide cells, also known as reversible solid oxide cells, can be used as solid oxide fuel cells and as solid oxide electrolysis cells. The solid oxide cell basically consists of three different layers—a middle layer of an oxide ion conducting electrolyte that is gastight that is sandwiched between electrode layers. The electrode layers are porous, electron and ion conducting and each solid oxide cell has an oxygen electrode and a fuel electrode. A solid oxide fuel cell is described in the following:
[0005] A solid oxide fuel cell (SOFC) is a high temperature fuel cell which generates electricity directly from an electrochemical reaction, and it is composed entirely of solid-state oxide materials, typically ceramics. This composition allows SOFCs to operate at much higher temperatures than other fuel cell types such as PEM fuel cells. Typical operating temperatures are 600° C. to 1000° C.
[0006] In the solid oxide fuel cell the oxygen electrode is the cathode where a reduction of oxygen to oxygen ions takes place. The fuel electrode is the anode where oxidation of hydrogen to hydrogen ions and then water takes place. An electrochemical energy conversion takes place in the solid oxide fuel cell, whereby electricity is generated from external supplies of fuel (on the anode side) and oxidant (on the cathode side). These react therefore at the electrodes in the presence of an electrolyte.
[0007] Usually the reactant flowing to the anode is a fuel such as hydrogen or methane. When methane is used as a fuel, internal reforming takes place at the anode surface whereby methane is reformed in the presence of steam to hydrogen and carbon monoxide. The hydrogen is then converted in the electrochemical reaction. The oxidant flowing to the cathode is usually air or oxygen.
[0008] Solid oxide fuel cells can be operated in reverse mode as solid oxide electrolysis cells (SOEC) to perform electrolysis of H 2 O and/or CO 2 for hydrogen or synthesis gas (a mixture of hydrogen, H 2 and carbon monoxide, CO) production.
[0009] In the solid oxide electrolysis cell the oxygen electrode is the anode where an oxidation of oxygen ions to oxygen takes place. The fuel electrode is the cathode where reduction of water to hydrogen takes place.
[0010] Conventional composite oxygen electrodes are manufactured using an electron conductive material such as lanthanum-strontium-manganite (LSM) and an oxygen ion conductive material such as yttria-stabilised zirconia (YSZ). These oxygen electrodes are deposited on a dense electrolyte surface made of an oxygen ion conductive solid oxide such as YSZ.
[0011] The reduction-oxidation reactions take place mainly at the triple phase boundaries where the electrode, the electrolyte and oxygen or hydrogen are in contact with each other. The triple phase boundary is therefore influenced by the reactions occurring at the interface between the electrode and the electrolyte. Efficient gas diffusion and increased contact areas between the electrolyte and the electrodes are therefore important.
[0012] Performance of the oxygen electrode is mainly determined by the resistance present at the oxygen electrode-electrolyte interface. It is desirable to reduce the interfacial resistance and increase the occurrence of triple phase boundaries. Thereby electrode polarisation resistance is decreased and the overall performance of the oxygen electrode is improved. The cell operation temperature and the partial pressure of oxygen in the oxygen electrode chamber also influence the performance of the oxygen electrode. Inadequate control of the above factors can lead to the formation of degradation products at the triple phase boundaries and thus a reduction in the SOFC or SOEC performance.
[0013] A known degradation product resulting in increased interfacial resistance between the oxygen electrode and the electrolyte is lanthanum zirconate, La 2 Zr 2 O 7 (abbreviated LZO). This undesirable degradation product is formed at the interface between the lanthanum-strontium-manganite (LSM) oxygen electrode and the yttria stabilised zirconia (YSZ) electrolyte and its formation is increased by heating of the for instance SOFC at high temperatures such as during sintering of the SOFC. The formation of LZO is also increased under high polarisation during cell testing.
[0014] Other known degradation products are strontium zirconate (SZO) and oxide compounds of La—Zr—Si, and Sr—Zr—Si.
[0015] Degradation of LSM-YSZ has been identified to be the dominant contribution to cell degradation under severe test conditions i.e. at low temperatures and high current densities. Barfod et al., Solid State Electrochemistry Proc. 26 th Risø, International Symposium on Materials Science, Risø National Laboratory, Roskilde, page 121 (2005), also point out that the degradation rate is strongly dependent on the oxygen partial pressure on the cathode side in solid oxide fuel cells, the degradation rate being significantly higher in air than in pure oxygen.
[0016] Both LZO and La-silicate have been reported by D. Kuscer et al., Solid State Ionics 78 (1995) 79, to form at a LaMnO 3 /YSZ interface during aging at 1450° C.
[0017] Studies (A. Hagen et al., Electrochemical Society Transactions, Vol. 2007-07, No. 1, page 301-309) indicate that LZO is present as nano-sized particles distributed locally and preferably in LSM/electrolyte contact areas in long term tested solid oxide fuel cells. The formation of nano-sized strontium zirconate (SZO) particles at the interface between the cathode and electrolyte may also be a possibility. Both LZO and SZO phases have insulating properties due to their low conductivity when compared to zirconia electrolyte, and their presence weakens the electrical contact of the cathode and electrolyte.
[0018] Various attempts have been made to inhibit the formation of lanthanum zirconate. U.S. Pat. No. 7,141,329 B2 discloses an electrode having a microstructure of extended triple phase boundary with a porous ion conductive ceria film coating. This coating is made from one or more doped oxide sols selected from CeO 2 polymeric sols or particulate sol and can be manufactured at a lower temperature by employing a sol-gel method resulting in preventing generation of undesired interfacial reaction products.
[0019] F. Umemura et al. (Denki Kagaku Oyobi Kogyo Butsuri Kagaku (Electrochemistry and Industrial Physical Chemistry) (Japan) v63:2. (5 Feb. 1995) page 128-133) evaluated the microscopical characterization of a degraded air electrode to examine the sintering and reaction of an electrode material. Half cells were produced and measured by La 0.9 Sr 0.1 MnO 3 and 8YSZ obtained when 8% Y 2 O 3 -stabilized zirconia was added. Adding the YSZ controlled the generation of La 2 Zr 2 O 7 in the interface between the electrode and electrolyte.
[0020] The electrochemical characteristics of La 1-x Sr x MnO 3 for solid oxide fuel cells and the formation of lanthanum zirconate has also been studied by H. M. Lee in Materials Chemistry and Physics, 2003, V77, N3 (January 30), page 639-646. The optimum amount of Sr in La 1-x Sr x MnO 3 for a solid oxide fuel cell cathode material was studied by observing the charge transfer resistance, electrical conductivity, and reactivity with the electrolyte. The reactivity between the electrolyte and La 1-x Sr x BO 3 (B=Cr, Mn, Co) was investigated and it was found that the secondary phase, La 2 Zr 2 O 7 , was not formed when the substitution amount of Sr was 50 moles.
[0021] Other known attempts to control the formation of LZO and SZO include utilising in the SOFC a LSM cathode containing a surplus of Mn. During preparation the LSM cathode is super stoichiometric in manganese, whereby manganese oxide is present as a secondary phase in the cathode.
[0022] JP patent application no. 5190183 discloses a solid oxide fuel cell with a fuel electrode containing yttria stabilised zirconia. Subsequently a slurry of powdered yttria stabilised zirconia powder and MnOx powder is made and this slurry is applied to the surface of the solid electrolyte, followed by calcination. Manganese thus exists in the three-phase zone consisting of fuel electrode, a solid electrolyte and the gaseous phase. The activation polarisation of the fuel electrode became smaller and output of the SOFC cell improved.
[0023] The chemical reactivity and interdiffusion of LSM and YSZ have been studied by J. A. M. Roosmalen, Solid State Ionics 52 (1992) page 303-312. They observe the formation of reaction products LZO and SZO and propose that resulting reaction layers including LZO and SZO might result in both ohmic and polarisation losses of the SOFC. They suggest that the ohmic losses are due to the low conductivity of the reaction products and the polarisation losses are due to the blocking of oxygen transfer at the three-phase boundary between cathode, electrolyte and oxygen. It is suggested to reduce the La and/or the Sr activity by decreasing the (La, Sr):Mn ratio in LSM.
[0024] However, these steps of introducing manganese in a super stoichiometric amount, though shown effective in reducing zirconate formation, are not enough to avoid the formation of LZO and SZO in the interface in the triple phase boundaries between the oxygen electrode comprising LSM and the YSZ electrolyte in solid oxide cells, when these are operated for prolonged periods and at strong polarisation.
SUMMARY OF THE INVENTION
[0025] It is therefore an objective of the invention to provide a solid oxide cell less prone to degradation.
[0026] It is a further objective of the invention to provide a solid oxide cell showing improved long term performance.
[0027] These objectives and others are accomplished by providing a solid oxide cell obtainable by a process comprising the steps of:
[0028] depositing a fuel electrode layer on a fuel electrode support layer
[0029] depositing an electrolyte layer comprising stabilised zirconia on the fuel electrode layer to provide an assembly of fuel electrode support, fuel electrode and electrolyte
[0030] optionally sintering the assembly of fuel electrode support, fuel electrode and electrolyte together to provide a pre-sintered half cell
[0031] depositing on the electrolyte layer of the pre-sintered half cell one or more oxygen electrode layers, at least one of the one or more oxygen electrode layers comprising a composite of lanthanum-strontium-manganite and stabilised zirconia to provide a complete solid oxide cell
[0032] sintering the one or more oxygen electrode layers together with the pre-sintered half cell to provide a sintered complete solid oxide cell
[0033] impregnating the one or more oxygen electrode layers of the sintered complete solid oxide cell with manganese to obtain a manganese impregnated solid oxide cell.
[0034] Sintering the assembly of fuel electrode support, fuel electrode and electrolyte together to provide a pre-sintered half cell is optional. If sintering is not carried out then the assembly of fuel electrode support, fuel electrode and electrolyte provides a half cell.
[0035] In this case the subsequent steps are as follows:
[0036] depositing on the electrolyte layer of the half cell one or more oxygen electrode layers, at least one of the one or more oxygen electrode layers comprising a composite of lanthanum-strontium-manganite and stabilised zirconia to provide a complete solid oxide cell
[0037] sintering the one or more oxygen electrode layers together with the half cell to provide a sintered complete solid oxide cell
[0038] impregnating the one or more oxygen electrode layers of the sintered complete solid oxide cell with manganese to obtain a manganese impregnated solid oxide cell.
[0039] Accordingly, the invention encompasses a solid oxide cell comprising a fuel electrode layer deposited on a fuel electrode support layer and an electrolyte layer comprising stabilised zirconia deposited on the fuel electrode layer, and deposited on the electrolyte layer one or more oxygen electrode layers, at least one of the one or more oxygen electrode layers comprising a composite of lanthanum-strontium-manganite and stabilised zirconia, and the fuel electrode, the fuel electrode support layer, the electrolyte layer and the one or more oxygen electrode layers being simultaneously sintered, and the sintered one or more oxygen electrode layers thereafter being further impregnated with manganese.
[0040] Accordingly, the invention encompasses a process for the preparation of the solid oxide cell comprising the steps of:
[0041] depositing a fuel electrode layer on a fuel electrode support layer
[0042] depositing an electrolyte layer comprising stabilised zirconia on the fuel electrode layer to provide an assembly of fuel electrode support, fuel electrode and electrolyte
[0043] optionally sintering the assembly of fuel electrode support, fuel electrode and electrolyte together to provide a pre-sintered half cell
[0044] depositing on the electrolyte layer of the pre-sintered half cell one or more oxygen electrode layers, at least one of the one or more oxygen electrode layers comprising a composite of lanthanum-strontium-manganite and stabilised zirconia to provide a complete solid oxide cell
[0045] sintering the one or more oxygen electrode layers together with the pre-sintered half cell to provide a sintered complete solid oxide cell
[0046] impregnating the one or more oxygen electrode layers of the sintered complete solid oxide cell with manganese to obtain a manganese impregnated solid oxide cell.
[0047] Furthermore, the invention provides a solid oxide cell stack comprising one or more the solid oxide fuel cells or one or more solid oxide electrolysis cells.
[0048] In an embodiment of the invention at least one of the one or more oxygen electrode layers comprises a composite of lanthanum-strontium-manganite and stabilised zirconia and the atomic ratio of manganese to lanthanum and strontium in the lanthanum-strontium-manganite is greater than 1.
[0049] This embodiment can be in combination with anyone of the embodiments disclosed above and below.
[0050] In an embodiment of the invention zirconia is stabilised with yttria, scandia, magnesia or calcium oxide.
[0051] In a preferred embodiment of the invention zirconia is stabilised with yttria.
[0052] In an embodiment of the invention impregnation with manganese of the one or more oxygen electrode layers is repeatedly carried out until at least one of the one or more oxygen electrode layers is impregnated with a predetermined amount of manganese.
[0053] In an embodiment of the invention impregnation of the one or more oxygen electrode layers with manganese is repeatedly carried out until the oxygen electrode layer comprising a composite of lanthanum-strontium-manganite and stabilised zirconia is impregnated with a predetermined amount of manganese. This embodiment can be in combination with anyone of the embodiments disclosed above and below.
[0054] In an embodiment of the invention manganese is impregnated on the surface of at least one of the one or more oxygen electrode layers in concentrations of 0.5 to 5 mg/cm 2 .
[0055] In an embodiment of the invention manganese is impregnated using an aqueous solution of manganese (II) salt.
[0056] In an embodiment of the invention the salt is a nitrate, sulphate or chloride.
[0057] In an embodiment of the invention the one or more oxygen electrode layers are deposited on the electrolyte layer by screen printing, spraying, tape casting or spray pyrolysis.
[0058] In an embodiment of the invention a solid oxide cell stack comprises one or more solid oxide cells. The solid oxide cell stack can comprise at least two solid oxide cells.
[0059] In an embodiment of the invention the solid oxide cell is a solid oxide fuel cell or a solid oxide electrolysis cell.
[0060] The solid oxide cell of the invention is characterized by having an interface between the oxygen electrode and the electrolyte that is rich in manganese. Manganese is present in excess and it can be present either locally at the triple phase boundaries between the electrolyte, the oxygen electrode and the oxygen gas or present as a layer situated between the oxygen electrode and the electrolyte.
[0061] The presence of manganese in excess either as a layer or locally at the triple phase boundaries efficiently protects the oxygen electrode/electrolyte interface from degrading during operation of the fuel cell stack by reducing the reactivity between LSM in the oxygen electrode and stabilized zirconia in the electrolyte. The risk of zirconate formation is decreased.
[0062] The invention relates to the reduction of degradation in solid oxide cells. It is concerned with the inhibition of degradation in electrodes of the lanthanum-strontium-manganite (LSM) type including composite electrodes of the LSM/NSZ (stabilised zirconia, where N represents different stabilising components) type in solid oxide fuel cells and solid oxide electrolysis cells.
[0063] Degradation has been identified as the loss of LSM coverage and the loss of triple phase boundary length. It is observed by a size reduction of the individual LSM/electrolyte contact areas and a decrease in triple phase boundary length due to the formation of at least one of the insulating phases LZO, SZO and Sr—Zr—Si oxide compounds. The insulating phases are present as nano-particles distributed locally and preferably in the LSM/electrolyte contact areas.
[0064] The solid oxide cell of the invention is suitable for use as either a solid oxide fuel cell or solid oxide electrolysis cell. It has a reduced concentration of one or more of the insulating phases LZO (the most important), SZO and La—Zr—Si or Sr—Zr—Si oxide compounds, when compared to a solid oxide cell having a conventional oxygen electrode. The reduced concentration is observed both before and after exposure to severe operation conditions such as strong polarisation and prolonged operation periods.
[0065] Additionally, the adhesion between the oxygen electrode and the electrolyte of the solid oxide cell of the invention is improved because the LSM grains are prevented from detaching themselves from the stabilized zirconia electrolyte surface.
[0066] The solid oxide cell has been modified in a specific manner in order to facilitate this reduction in the formation of the insulating phases. The modification comprises sintering of the solid oxide cell after deposition of the oxygen electrode layer followed by impregnation of the oxygen electrode layer with a manganese solution.
[0067] Preparation of the solid oxide cell of the invention is described in detail as follows:
[0068] A fuel electrode support layer is prepared preferably by tape casting. A fuel electrode layer is deposited on the fuel electrode support layer by for instance spraying or other methods well known in the art. The fuel electrode layer and the fuel electrode support layer can be any conventional materials useful in the preparation of solid oxide cells.
[0069] For solid oxide cells the fuel electrode support layer can for instance be a Ni-NSZ composite, where N can represent Mg, Ca, Y, Sc or other elements known in the art for instance Ce and Gd.
[0070] The fuel electrode layer can alternatively be a porous metal based on Fe—Cr alloy particles. Furthermore, the fuel electrode layer can be a ceramic such as doped SrTiO 3 .
[0071] Preferable for solid oxide fuel cells are Ni-NSZ composites and a porous metal based on Fe—Cr alloy particles and preferable for solid oxide electrolysis cells are ceramics such as doped SrTiO 3 .
[0072] For solid oxide cells the fuel electrode layer can for instance be (1) a Ni-NSZ composite where N represents Mg, Ca, Y, Sc, and (2) a ceramic such as doped SrTiO 3 .
[0073] Preferable for solid oxide fuel cells are 1) and 2) and for solid oxide electrolysis cells is 2).
[0074] An electrolyte layer is deposited on the fuel electrode layer. The electrolyte layer is stabilised zirconia, generally abbreviated to NSZ, where N denotes the stabilising element. N represents yttrium, scandium, magnesium or calcium. Preferable is yttria stabilised zirconia (YSZ) and most preferable is Y 0.15 Zr 0.85 O 1.925 (abbreviated TZ8Y) for both solid oxide fuel cells and solid oxide electrolysis cells.
[0075] Deposition can preferably be carried out by spraying, screen printing, spray pyrolysis, tape casting or other methods known in the art.
[0076] The assembly of the fuel electrode support layer, the fuel electrode layer and the electrolyte is generally termed a half cell. The half cell obtained based on these components can optionally be sintered also termed pre-sintering. Typically the half cell is sintered to provide a pre-sintered half cell. Sintering can be carried out at temperatures above 1200° C. An advantage of including this sintering step is the formation of a strong half cell for subsequent processing where oxygen electrode application method and sintering temperature can be chosen within a wider range.
[0077] One or more oxygen electrode layers are then deposited on the electrolyte layer of the half cell or of the pre-sintered half cell, and at least one of the oxygen electrode layers comprises a composite of lanthanum-strontium-manganite and NSZ (LSM-NSZ), where N is selected from the group consisting of Mg, Ca, Y, Sc and mixtures of these elements. LSM is stoichiometric or super-stoichiometric with respect to manganese. Manganese may thus be present in excess in the oxygen electrode composition. Preferably, manganese is present in excess in amounts up to 10 wt %.
[0078] By stoichiometric is meant that the atomic ratio Mn/(La+Sr) equals 1, i.e. that the material is synthesised such that the concentration of the elements matches the one for a perfect perovskite. There are equal amounts of (atomic %) of the elements that go on the A-site in the structure (La, Sr) and elements that go to the B-site (Mn).
[0079] By superstoichiometric is meant that the compound is synthesised such that there is an excess of Mn relative to the 1:1 ratio of the stoichiometric compound, i.e. the ratio manganese to lanthanum and strontium (Mn/(La+Sr)) is larger than one (atomic %). This imbalance leads to the formation of vacant A-sites in the material and/or formation of small amounts of secondary Mn oxide phases such as MnO, MnO 2 or others.
[0080] An example of a LSM-NSZ layer suitable as an oxygen electrode layer is 50 wt % LSM-50 wt % YSZ.
[0081] A complete solid oxide cell is obtained when the one or more oxygen electrode layers are deposited on the electrolyte layer of the half cell or the pre-sintered half cell.
[0082] The oxygen electrode layer can also be a composite multilayer consisting of two or more layers of different composition, where at least one layer is a composite of LSM-NSZ, where N for instance is yttrium. An example of a dual oxygen electrode layer can consist of a first oxygen electrode layer of LSM-NSZ and a second oxygen electrode layer of LSM. In a preferable embodiment of the invention N is yttrium.
[0083] The oxygen electrode layers can be deposited on the electrolyte layer of the half cell or of the pre-sintered half cell by different methods such as screen printing, tape casting, spraying, spray pyrolysis or other similar methods known in the art.
[0084] The oxygen electrode layer that is a composite of LSM-NSZ can have a thickness of 5 to 40 microns, and the oxygen electrode layers that are not a composite of LSM-NSZ can have a thickness of 10 to 100 microns. The electrolyte layer can have a thickness of 1 to 20 microns. The fuel electrode layer can have a thickness of 1 to 20 microns and the fuel electrode support layer can have a thickness of 200 to 1000 microns.
[0085] After deposition of a predetermined amount of the one or more oxygen electrode layers on the electrolyte layer, the half cell or pre-sintered half cell deposited with the one or more oxygen electrode layers is sintered to provide a sintered complete solid oxide cell. This step is important in order to ensure the adherence of the oxygen electrode to the electrolyte. Sintering takes place at temperatures of 900° C. to 1300° C., preferably 950° C. to 1100° C.
[0086] After sintering, the one or more oxygen electrode layers of the sintered complete solid oxide cell are impregnated with manganese. The impregnation can be done by using a manganese solution, which can be an aqueous solution of a manganese salt, for instance a manganese (II) salt. The salts can for instance be nitrates, sulphates, chlorides or other conventional salts suitable for forming an aqueous solution of a manganese salt. Preferable are nitrates. A manganese impregnated solid oxide cell is obtained.
[0087] Impregnation of Mn (II) onto the oxygen electrode can also be carried out by a combustion synthesis process. For example as follows: a precursor combining glycine with Mn-nitrate in an aqueous solution can be dripped onto the oxygen electrode while the cell is heated. The precursor is also heated to evaporate excess water thereby yielding a viscous liquid. Further heating to about 180° C. caused the precursor liquid to auto ignite, and Mn (II) is impregnated into the oxygen electrode.
[0088] It is a preferable embodiment of the invention that manganese nitrate is deposited on the surface of the oxygen electrode layer in concentrations of 0.5 to 5 mg/cm 2 , corresponding to 0.5-5 mg Mn per cm 2 at the oxygen electrode/electrolyte interface. At these concentrations manganese is present in excess either locally at the triple phase boundaries between the electrolyte, the oxygen electrode and the oxygen gas or is present as a layer situated between the oxygen electrode and the electrolyte. More preferably it is deposited at a concentration of 0.5-3 mg/cm 2 .
[0089] The impregnation can be repeatedly carried out in order to obtain a predetermined concentration of manganese on the surface of the oxygen electrode layer. It can be vacuum assisted if required.
[0090] After impregnation with manganese the solid oxide cell obtained is dried by heating at a temperature of up to 300° C. After drying the resulting solid oxide cell is suitable for use in a solid oxide fuel cell stack or a solid oxide electrolysis stack.
[0091] Application of a solid oxide fuel cell obtained by the inventive process in a solid oxide fuel cell stack leads to a reduction in the content of at least one of the degradation products LZO, SZO, La—Zr—Si and Sr—Zr—Si in the triple phase boundaries between the oxygen electrode, electrolyte and the gas after exposure to severe operating conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0092] FIG. 1 illustrates aging tests of standard SOC cells and SOC cells of the invention.
[0093] FIG. 2 illustrates X-ray diffractograms of YSZ/LSM powder mixtures after heat treatment in air or nitrogen.
[0094] FIG. 3 shows a SEM-image of the electrolyte/oxygen electrode interface of an SOC cell of the invention after 1500 hr of testing.
[0095] FIG. 4 shows a SEM-image of the electrolyte/oxygen electrode interface of a standard SOC cell after 1500 hr of testing.
[0096] FIG. 5 shows a SEM-image of the electrolyte/oxygen electrode interface of the same SOC cell as in FIG. 3 at a larger magnification.
[0097] FIG. 6 shows a SEM-image of the electrolyte surface after removal of the oxygen electrode from a SOC cell of the invention after 1500 hr of testing.
[0098] FIG. 7 shows a SEM-image of the electrolyte surface after removal of the oxygen electrode from a standard SOC cell after 1500 hr of testing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Examples
Example 1
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0099] A solid oxide cell whose oxygen electrode/electrolyte interface contains Mn in excess concentration is manufactured by the following steps:
[0000] (1) tape-casting a fuel electrode support layer (AS)
(2) Spraying an fuel electrode layer (A) on the surface of the fuel electrode support layer
(3) Spraying a 10 micron electrolyte layer (E) of 8% Y 2 O 3 — stabilised zirconia (TZ8Y) on the surface of the fuel electrode layer to obtain a half cell
(4) sintering the half cell at a temperature above 1200° C.
(5) Screen printing a LSM-YSZ oxygen electrode layer of 20-30 microns in thickness on the surface of the electrolyte layer
(6) simultaneously sintering the half cell and the LSM-YSZ oxygen electrode layer deposited on the half cell
(7) impregnating the oxygen electrode layer with Mn-Nitrate aqueous solution prepared by dissolving 10 g Mn-nitrate in 100 ml distilled water. Repeating the impregnation step until a concentration of 0.5-5 mg Mn/cm 2 is obtained in the impregnated cell.
(8) drying the impregnated cell by heating at a temperature of 80° C. to obtain a solid oxide cell.
[0100] The following details refer to the preparation steps of example 1:
[0101] The suspension for tape-casting is manufactured by means of ball milling of powders with polyvinyl pyrrolidone (PVP), polyvinyl butyral (PVB) and ethanol (EtOH) and methyl ethyl ketone (MEK) as additives. The suspension is tape-cast using a double doctor blade set-up and the tape is subsequently dried.
[0000] (1) AS layer: The suspension comprised 45 vol % yttria stabilised zirconia (YSZ) and 55 vol % NiO powder. The green thickness of the tape-cast layer was in the range of 400 μm. The porosity of this layer was in the range of 30% after sintering and reduction.
(2) A layer: The slurry of A layer comprised 40 vol % YSZ and about 60 vol % NiO powder. After spraying and sintering the thicknes of the A-layer was approximately 10 μm. The porosity of this layer was approximately 25% after sintering and reduction.
(3) E layer: The slurry of E layer comprised TZ8Y. After spraying and sintering the thickness of the E layer was approximately 10 μm.
(4) The half-cell consisting of the fuel electrode support layer, the fuel electrode layer and the electrolyte layer was sintered in a furnace at a temperature above 1200° C. with a ramp up of 100° C./h and left for about 12 hours to cool to room temperature to form a sintered half cell.
(5) An oxygen electrode layer was deposited on the sintered half-cell by screen printing an ink comprising a 1:1 weight ratio mixture of La 0.75 Sr 0.25 Mn 1.05 O 3-δ and YSZ on the surface of the electrolyte layer (E). The thickness of the oxygen electrode layer was 20-30 μm before sintering.
(6) sintering of the half cell deposited with an oxygen electrode layer in a furnace at approximately 1100° C. for 2 hours and then cooling to room temperature.
(7) impregnating the oxygen electrode layer with manganese: A Mn-Nitrate aqueous solution was made by dissolving 10 g Mn-Nitrate (purity 99.999%) in 100 ml distilled water. The solution was dripped on the surface of the porous oxygen electrode layer by an eye dropper. The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to obtain a solid oxide cell.
(8) Drying the impregnated solid oxide cell by heating on a hot plate at approximately 80° C. for 5 min.
Example 2
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0102] A cell was manufactured as outlined above for Example 1, with the exception that in step 7 the impregnation was vacuum assisted.
[0103] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to obtain a solid oxide cell.
Example 3
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0104] A solid oxide cell was manufactured as outlined in Example 1 with the exception that in step 7 vacuum assisted impregnating the porous oxygen electrode layer with a Mn-Nitrate solution containing a surfactant Triton-X 100 that was made by dissolving 1 g Triton-X 100 in 100 ml Mn-Nitrate solution.
[0105] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to the final solid oxide cell
Example 4
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0106] A solid oxide cell was manufactured as outlined above for Example 1 with the exception that in step 3 the E-layer was screen printed. The thickness of the electrolyte layer was approximately 10 μm.
[0107] In step 5 an oxygen electrode layer was deposited on the sintered half-cell by spraying a slurry comprising a 1:1 weight ratio mixture of La 0.75 Sr 0.25 Mn 1.05 O 3-δ and YSZ on the surface of the electrolyte layer (E). The thickness of the oxygen electrode layer was 20-30 μm before sintering.
[0108] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to the final solid oxide cell.
Example 5
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0109] A solid oxide cell was manufactured as Example 4 with the exception that in step 7 the impregnation was vacuum assisted.
[0110] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to the solid oxide cell.
Example 6
[0111] A solid oxide cell was manufactured as Example 4, with the exception that in step 7 vacuum assisted impregnation of the porous oxygen electrode layer with Mn-Nitrate solution containing a surfactant Triton-X 100 made by dissolving 1 g Triton-X 100 in 100 ml Mn-Nitrate solution.
[0112] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to obtain a solid oxide cell.
Examples 7-12
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration Using Manganese Sulphate for Impregnation
[0113] These examples were carried out in the same manner as in Examples 1 to 6. However, Mn-sulfate was used instead of Mn-nitrate to prepare the aqueous solution for impregnation.
Example 13-18
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration Using Manganese Chloride
[0114] These experiments were carried out as in Examples 1 to 6, but Mn-chloride was used instead of Mn-nitrate to prepare the aqueous solution for impregnation.
Example 19
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration
[0115] A solid oxide cell was manufactured as Example 1, with the exception that in step 1 the suspension comprised Fe—Cr alloy powder, organic binder and pore former. The green thickness of the fuel electrode support tape-cast layer was about 400 μm. The porosity of this layer was in a range of 20-30%; after sintering.
[0116] The impregnation process was repeated at least twice to supply a concentration of 0.5-5 mg Mn/cm 2 on the oxygen electrode surface to obtain a solid oxide cell.
Example 20
Preparation of a Solid Oxide Cell Containing Manganese in Excess Concentration by Combustion Synthesis
[0117] A solid oxide cell was manufactured as Example 1 with the exception that in step 7 a combustion synthesis process was used to impregnate Mn (II) onto the oxygen electrode. A precursor combining glycine with Mn-Nitrate in an aqueous solution was dripped onto the oxygen electrode, while the cell was heated. The precursor was heated to evaporate excess water yielding a viscous liquid. Further heating to about 180° C. caused the precursor liquid to auto ignite, and Mn (II) was impregnated into the oxygen electrode.
[0118] The positive effect of adding Mn(II) to the electrolyte/oxygen electrode interface by impregnation with an aqueous solution containing Mn(II) is documented in the following 5 figures.
[0119] FIG. 1 illustrates aging tests of two standard (conventional) solid oxide cells A and B and three solid oxide cells of the invention C, D and E. The cell voltage was recorded at constant current as a function of operation time. The cells were aged at 750° C. under strong polarisation (current density, i=0.75 A/cm 2 ) under 1500 hours of test.
[0120] The three solid oxide cells of the invention C, D and E had been impregnated with manganese after deposition of the oxygen electrode layer and sintering and had a concentration in the range of 0.5-5 mg Mn/cm 2 . It can be seen that the C, D and E stabilize with respect to cell voltage much earlier than A and B, which continue to loose cell voltage throughout the operation time. The performance of the solid oxide cells of the invention therefore show better long term durability than the standard cells tested which show strong degradation.
[0121] The beneficial effect of impregnating the oxygen electrode layer with Mn is presumably to suppress the formation of La-zirconate and Sr-zirconate and other degradation products mentioned earlier. That the strong degradation observed for the standard cells is likely to be related to zirconate formation is supported by the findings reproduced in FIG. 2 .
[0122] FIG. 2 illustrates X-ray diffractograms of YSZ/LSM powder mixtures after various heat treatments in air or nitrogen. Sample F shows results obtained after exposure of the YSZ-LSM powder mixture to 1000° C. in nitrogen for 9 weeks, while the Sample G shows the results obtained after exposure of the YSZ-LSM powder mixture to 1000° C. in nitrogen for 9 weeks followed by exposure to 1000° C. in air for four weeks.
[0123] Here, results of powder reactivity tests are shown and it can be seen that both samples F and G show peaks for YSZ (at 2θ≈30.1) and LSM (at 2θ≈32.4, 32.6). However, sample F shows an additional peak for SrZrO 3 at 2θ≈30.9. The same peak was also observed for sample G. However, it disappeared after four weeks exposure to air.
[0124] The zirconate formation is thus shown to be strongly dependent on the partial pressure of oxygen, pO 2 . Zirconate degradation products form if powder mixtures are heat treated in N 2 . It disappears again if powders are subsequently heat treated in air. This finding supports the working hypothesis that the reason that the cell degradation rate increases with increasing polarization is related to formation of zirconate, as increasing the polarization corresponds to a reduction in the pO 2 at the oxygen electrode-particle-electrolyte interface. At low current density (i=0.25 A/cm2) where the relevant partial pressure of oxygen, pO2, in the oxygen electrode/electrolyte interface is much closer to that characteristic of air no degradation is observed.
[0125] The addition of super stoichiometric amounts of manganese is known to provide a reduction in the degradation. However this reduction is not effective in the long term when operation of the solid oxide cells is carried out for prolonged periods or at high polarisation.
[0126] FIG. 3 shows an SEM-image of the electrolyte/oxygen electrode interface of a SOFC cell of the invention after 1500 hr of testing at 750° C., i=0.75 A/cm 2 . The interface microstructure differs greatly from the standard SOFC cell (see FIG. 4 ). A layer with increased Mn content is observed by EDS in the cell of the invention but not in the standard cell. The oxygen electrode in the cell of the invention adheres better to the electrolyte than in the standard cell.
[0127] FIG. 4 shows an SEM-image of the electrolyte/oxygen electrode interface of a standard SOFC cell after 1500 hr of testing at 750° C., i=0.75 A/cm 2 .
[0128] FIG. 5 shows an SEM-image of the electrolyte/oxygen electrode interface of the same cell as in FIG. 3 but with a larger magnification. Secondary phases are seen in the interface region.
[0129] FIG. 6 shows an SEM-image of the electrolyte surface after removal of the oxygen electrode of SOFC cell of the invention after 1500 hr of testing at 750° C., i=0.75 A/cm 2 . Unlike the standard cell shown in FIG. 7 , most LSM craters are free of nano-particles. In addition to LSM craters, there are also a large number of imprints of irregular shape. They are likely due to a new phase that was introduced to the interface by Mn-impregnation and helped to anchor the oxygen electrode to the electrolyte.
[0130] FIG. 7 shows an SEM-image of the electrolyte surface after removal of the oxygen electrode of the cell after 1500 hr of testing at 750° C., i=0.75 A/cm 2 . Small LSM craters are observed with zirconate nano-particles at the crater rim.
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A solid oxide cell obtainable by a process comprising the steps of: depositing a fuel electrode layer on a fuel electrode support layer; depositing an electrolyte layer comprising stabilised zirconia on the fuel electrode layer to provide an assembly of fuel electrode support, fuel electrode and electrolyte; optionally sintering the assembly of fuel electrode support, fuel electrode and electrolyte together to provide a pre-sintered half cell; depositing on the electrolyte layer of the pre-sintered half cell one or more oxygen electrode layers, at least one of the oxygen electrode layers comprising a composite of lanthanum-strontium-manganite and stabilised zirconia to provide a complete solid oxide cell; sintering the oxygen electrode layers together with the pre-sintered half cell to provide a sintered complete solid oxide cell; and impregnating the one or more oxygen electrode layers of the sintered complete solid oxide cell with manganese to obtain a manganese impregnated solid oxide cell.
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BACKGROUND OF THE INVENTION
[0001] Board sports have been extremely popular in the last two decades. Skate boarding, snow boarding, wake boarding and surfing all provide dynamic and exciting means for individuals inclined to a sport that requires balance, strength, coordination, and a sense of adventure.
[0002] The board used in any of these board sports is often made air-born for tricks and maneuvers, and while board sports such as snowboarding and wakeboarding have required the use of bindings, others such as skateboarding have been limited in the degree to which one can acquire an extended aerial pursuit without the use of a binding system.
[0003] A skateboarder, after dedicating much practice and effort, can learn how to elevate into the air with a move called an “ollie” which has become the basis for most modern tricks in skateboarding today. An ollie maneuver is done when the rider snaps the tail of the skateboard with their back foot so that the back of the board hits the ground sharply while the front foot makes an upward motion. Learning how to perform an ollie requires great skill that only a dedicated skateboarder accomplishes. Often times this can be discouraging to a casual skater. Also the skilled skater eventually wants to extend the time in the air to make the board behave more like a snowboard, which is to capture air for a longer period of time.
[0004] The earliest known invention with the idea of getting a board in the air without an “ollie” type maneuver was with the use of “skyhooks” developed in the early 1980's. Sky hooks was a form of a protruding half-binding system mounted on a skate board around each foot position. To have it work you would press the outsides of your feet against the large protruding hooks and jump.
[0005] More recently, Magnatron, a company that came into the board sports business for only a year, sold magnetic shoes and boards with metal plates in them. The company filed several patent applications that published describing a magnetized skateboard and snowskate shoe-board attachment system. US Pub 2003/0075890 describes a system with large metal plates in the board, and two magnets in each shoe. US pub 2003/0094788 describes a magnetic snowboard/snowskate system fashioned along the same principles as the skateboards. Finally US Pub 2004/0104551 describes a board having magnets, and a strap-on metal plate for the shoes. However, the devices described in all these applications severely compromise a rider's freedom of movement. Two magnets are placed in each shoe and connect to a metal plate located on the board. The two magnets made the shoe stiff and unmovable once attached, therefore not allowing a rider to adjust their stance and keep balanced. Furthermore, the ferrous metal plate in the board was a large oval-ish rectangle that made the board too heavy for optimum performance.
[0006] The system described in US Pub 2004/0104551 is somewhat different than the other applications because the board has magnets, and the shoes have strap-on metal plates. This system is particularly cumbersome. If anything, a board rider would want to eliminate bulk weight as much as possible in order to balance and maneuver better on the board, and adding the metal plates with straps does the opposite. Also, the only way to mount magnets in a skateboard using a thickness of magnet that imparts sufficient magnetic strength to hold a rider to the board is to mount the magnet in between the trucks. The trucks are the bracing by which the skateboard wheels attach to the board. The magnet in this system is required to be encased in steel to utilize its full strength, and the encasement requires thickness greater than the board. So the only place to mount the magnets is in between the trucks, where a thicker piece of metal encasement can be placed. The end result of the invention is a bulky board, stiff shoes and a system that is hard for a rider to use.((and with no utilization of the tail))
[0007] As evidence that the problem has been not so easy to solve, the Magnatron system is similar to another poorly designed magnet shoe system developed in France by a company named 4Size. The 4Size system has a bulky block magnet placed in the middle of the shoe. The magnet contacts 2 rectangular plates positioned directly between the trucks on the board which is not where an experienced rider normally stands on a skateboard. The positioning required with the 4Size design makes maneuvering and trick performance nearly impossible, and forces a rider to adopt a stiff stance while riding attached to the board with no utilization of either end of the board for critical tricks. The invention (also represented in a patent is issued to Philippe Riandet in France) can be viewed in its commercial embodiment at www.4size.com.
[0008] Clearly more development has been needed to optimize the idea of magnetic attachment for board sports.
SUMMARY OF THE INVENTION
[0009] The inventor was motivated to invent the magnetic device to provide a releasable magnetic attachment system. The inventor also wanted to design a system that would enhance rather than inhibit performance on a sports board in contrast to previous attachment systems. Such a system could be a viable training tool for young board riders and a tool for optimized performance for the experienced rider. Such a system carries with it the possibility of taking any board sport to new levels of physical achievement and excitement and further opens the door to inter-combining sports techniques.
[0010] For example, the ollie, a move particular to skateboarding, is a very difficult feat for the inexperienced rider, but with the magnetized attachment system of the invention, “air” otherwise achieved using an ollie move without the attachment, can be achieved without doing the ollie.
[0011] In addition, skateboard long boards re-create a surfing experience and could easily create an experience on a “dry” board more akin to snowboarding using the magnetized attachment system of the invention. New types of board sports may also develop (such as “mag boarding”) as a result of the technology embodied in this invention.
[0012] The invention described herein to an advanced magnetic attachment system was developed by a professional multi-board enthusiast. This inventor was motivated to provide a system that potentially combines more than one board sport and allows new versions of sports boarding to emerge. Especially for skateboarding, but also for the other board sports, magnetic attachment has an advantage for training purposes and allows a rider to perform and enjoy air born maneuvers (e.g. such as air born spinning maneuvers) more easily by being attached to the board.
[0013] The invention is a magnetic device capable of being inserted in a shoe for attaching the shoe to a board (e.g. a sports board such as a skate board, a long skate board, a snow skate board, a wake board, a surf board, and a long surf board). The basic idea is that a first magnetized object (optimally a magnet) is placed in shoes worn by the board rider, and a second magnetized object (optimally a plate of ferrous metal) is placed within the surface of the board. The magnetized metal plate is usually placed in both a front and a back position on the board. The two magnetized objects (typically a magnet in the shoe and a metal plate in the board) have a strong magnetic attraction between them, and allow the board rider to remain attached to the board when wearing the magnet-containing shoes. The downfall of prior versions of such a system has been that they have not been user friendly, and thus they were not commercially successful. The inventor of the present invention has meticulously developed and tested versions of his system to overcome all these prior short comings in the development of his device and system.
[0014] Optimally the system of magnetic attachment, in the simplest form, includes a sports board that has one magnetized plate in the front of the board and one magnetized plate in the back. The shoe-wearer/board rider becomes magnetically attached to the board when magnets in one or both shoes of the rider's pair of shoes align with the plates embedded in the board.
[0015] The attachment plates for any given board can be two small round plates of ferrous metal one each at the front and back end of the board (e.g. about 2 inch diameter spheres, see FIG. 1A and 1D ). A note here is warranted about these plates, and their size, shape and placement. The size of the plate is optimally as small as possible to provide the necessary contact but so as to not to add significant weight to the board, and thus based on geometric principles, the most economical shape for the plates is generally a sphere. However, through iteration and experimentation, the inventor found that an optimal shape for the front plate can be an oval or oval-like shape. Unlike the sphere which is attached to the bottom of the board with a single bolt in the center of the sphere, the oval is attached using 2 bolts (or other attachment means such as a rivet or pin, or other attachment member) to the bottom of the board, see FIGS. 6B and 6C .
[0016] For the back of the board, the inventor determined that the most significant choice affecting the use and comfort of the board is the position selected for the plate. Optimally, the plate is placed in the tail of the board, rather than right at the trucks. (The tail is a particular section of the back of the board where the board begins to curve up). If properly placed at the tail, the plate can be the minimum size, which is a sphere of about 2 inches diameter (held by a single bolt in the center of the sphere, see FIG. 6A ). Unlike previous board attachment systems, the inventor has determined that placing the metal plate at the tail (and not between the back trucks as others have done) significantly optimizes control and balance for the rider. An oval shaped plate can be placed at the tail of the board, but the oval is a larger surface area and adds more weight to the board. A single sphere properly placed at the tail will generally suffice and provides the rider all the attachment surface area required at the back of the board for good foot placement there.
[0017] In contrast, the front of the board benefits from the increased surface area for attachment because optimal front foot placement is more varied from rider to rider, and from trick to trick. The slight increase of surface area with the oval is well worth the compromise of some additional weight to the board because the rider is provided the needed flexibility of more options for front foot placement. This goes to ultimate flexibility and optimization of the system for the rider (see FIGS. 6D and 6E ). Accordingly, the front plate can be a slender horizontal oval shape to cover a wider area with minimized addition of weight.
[0018] In addition to plate size and placement, other elements of the system have been configured together to produce a device and system that goes beyond simply attaching the rider to the board. Over years of riding and testing, the inventor has optimized the configuration of the elements to make magnetic attachment to the board feel like a natural progression in the development of board sports generally, with particular attention to skate boarding and snow boarding. The device is optimized from previous magnetic shoe devices by having the magnet hang, free-float, or dangle from a support in the shoe. Previously magnets in shoes have been fixed rigidly in the shoe on the theory that it was important that the magnet remain in the shoe in an immovable position. However, the rigid design actually had a counter productive effect on the prior systems because it did not allow use of the magnet's full sticking potential. With the feet flatly positioned over the metal plates, no leeway of foot movement (up and down) was possible because all the attachment elements were solidly aligned. Any slight movement upward with the rider's heel would cause the stiff magnetic configuration of the magnets to break loose. The use of a double magnet (Magnatron) made this negative result not as bad by applying a stronger attachment power, yet more impractical because it was even more limiting than a single magnet in the shoe. But the double magnet system required more effort for the rider to break free from the board when needed, which could have disastrous effects at moments of emergency.
[0019] The new invention adopts a single free floating type of a hanging magnet. The inventor likens the hanging, free-floating magnet attachment to the role joints and tendons play around bones within the human body. The magnet's relationship to the support in the shoe incorporates the essential needs of desired flex and offers controllability within the range of motion required. With the invention, the rider now has some ability to adjust the foot position: up and down with heel movement, right and left with rotation of the magnet, and generally from side to side as needed in response to the ride. The support in the shoe is generally a straight support member, depicted in the figures going straight across the width of the shoe. The support member can and may however, be positioned in the shoe extending at an angle from the side of the shoe in order to place the magnet in the proper position under the ball of the foot, or for other logistical reasons having to do with shoe size, and shoe design, and other factors. Accordingly, the support is not required to be positioned exactly horizontal in the shoe (or exactly perpendicular to the side of the shoe), but can be at an oblique or acute angle relative to the side of the shoe.
[0020] The magnet, optimally with a round flat face, and strong neodymium characteristics, (e.g. a magnet having a strength in a range from about n38 to about n42 with a pull force of up to about 75 lbs. For example, the magnet should have a pull force in a range from about 30 lbs for small riders to about 50 lbs for mid-sized riders and at least about 75 lbs for larger riders, and in some cases reaching a pull force of 90 lbs when necessary to retain an even larger rider, or a rider requiring a tighter attachment to the board for the moves they want to do. Though relatively small in contact surface area (e.g. in a range of about 0.5 inches to about 2.5 inches diameter, optimally about 1.0 inches diameter) is positioned in an optimal spot on the bottom of the shoe, approximately under the ball of the foot. The optimal position is a position where the shoe wearer retains some flexibility of movement with his foot and shoe, and can also move the shoe somewhat around the magnet which stays fixed to the metal plate on the board. Upon lifting the heel of the shoe beyond the “attachment range” the magnet detaches from the board, and the rider is released. By having a relatively strong magnet but a small surface area of the magnet face, the magnetic device allows the rider to remain attached to the shoe while performing a greater range of foot and shoe movements.
[0021] Risk of unintended detachment from the board is minimized by the relatively high magnet strength, the position of the magnet at the bottom of the shoe, and the position of the magnetized metal plates on the board. The present invention provides a greater range of movement to the foot before risking detachment from the board than previously designed or envisioned by other board sports designers and inventors.
[0022] Another key feature of the device and system of the invention is the way the magnet is held in the shoe. The magnet is held by a support placed within the shoe sole. The interconnection between the magnet and the support facilitates a free floating/hanging configuration of the magnet from the support, which contributes to both the versatility of movement for the rider, and the safety of the system. The free-floating/hanging aspect of this feature allows foot flexibility during attachment to the board. Continued near full-range use of the shoe when magnetically attached to the sports board is critical to facilitating the improvement provided by the attachment system of this invention. The freedom of movement allows the rider's heel to extend upward to its maximum height before releasing the magnetized shoe from the magnetized metal plate in the board. The smaller surface area of a single magnet also contributes to this feature as it results in an easier release when rider executes the forced heel movement, or quick swivel action of the foot, both of which cause the shoe to release from the board.
[0023] The magnet releasibility contributes to the safety of the system. Increased safety is provided by the invention, because flexibility is allowed in the foot movements (without premature release), and releasibility can be quickly and specifically achieved once it is desired. Note that this is also a learned process the rider takes note of while practicing on a soft surface such as grass or carpet and with the desired safety gear like wrist guards, knee pads, and helmets.
[0024] The magnet is optimally placed on the bottom of the shoe about ⅔ of the way from the heel of the shoe, or about ⅓ the way from the toe of the shoe in a long axis from heel to toe, and approximately slightly below the ball of the foot. Position adjustments of the magnetic device in the shoes may be needed for different size shoes. Adult and child systems might be designed with slightly different specifications regarding slight adjustments of where the magnet is placed on the bottom of the shoe, the strength of the magnets, and also possibly where the magnetized metal plate is placed on the board.
[0025] In addition, the configuration of a single magnet in the shoe, rather than two magnets, frees-up movement, allowing more rotation with feet (and shoes) in maneuvers to perform tricks while the rider remains stuck to the board.
[0026] The invention makes the best use of a single magnet situated in the best possible location in a shoe. The importance of positioning goes the same for the board in using a minimal magnetized metal attachment area where one would need it, in this case slightly off center or centered depending on the width of the board for the front position, or slightly off center and at the tail for the back position. Prior boards have positioned the metal almost directly over the trucks and centered, which is suboptimal for performance and riding in an enjoyable surf stance position.
[0027] The system can have the following alternative embodiments: only one attachment position (i.e. either in the front of the back of the board, and only one corresponding magnetized shoe), also, the magnet can be in the board and the metal in the shoe or shoes, or the magnetic attraction can be with two magnets (i.e. a magnet in the shoe and a magnet in the board).
[0028] The magnetic shoe and magnetized metal board system of this invention trains an already familiar rider to further enhance their riding skills along with their enjoyment. By combining this new way of attachment and the already established techniques and tricks from various board sports, enjoyment and achievement in any board sport will be increased and pushed to new levels.
[0029] Another feature of the system is that the magnet can be removed from the shoe and replaced by a plug to return the shoes to normal use. By removing the magnet and replacing the hole in the shoe where the magnet was with a plug, the shoe no longer attaches to magnetized metal. The removed magnet can be stored by attaching it to a shield or guard of some kind, such as a rubberized metal plate to which two magnets (i.e., one from each shoe) can be attached (one each on each side of the plate). This protects the magnets from random attachment to unwanted magnetized objects.
[0030] In a particularly useful embodiment, rather than remove the magnet from the shoe, the magnet is left in the shoe and within the shoe can be raised up (for “off”) or lowered down (for “on”) by the use of a manual raising and lowering system. This can be accomplished by, for example, the magnet hung or free-floating from a bar that spans the width of the shoe. The bar can have a kink or bend in it such that upon turning of a lever connected to the bar the magnet is raised or lowered within a space in the shoe sole provided for the magnet. When “on” in the down position, the magnet is flush with the bottom of the shoe. When up in the “off” position, the magnet is recessed in the shoe. A rubberized plug or shield having a very thin ferrous (i.e. magnetized) metal plate can be placed in the recess of the shoe near the magnet when it is raised, to make the shoe surface flush, and to protect the shoe from attaching randomly to unwanted magnetized objects (e.g., metallic debris such as nails or screws found on walking paths or any other miscellaneous iron containing objects.). Lost plugs can be replaced easily as an accessory to the shoe system at a shoe store or online source that sells the magnetized shoes.
[0031] Being able to turn the magnetization on and off, provides the rider with a convenient and versatile “dual-use” shoe, a tremendous advantage for the active board sports aficionado who might use their board to get to school or work, and then prefer not to change shoes once at their destination. The dual use also gives the rider the option to ride their board without the use of the magnets when they want to.
[0032] The board configuration with the magnetized metal plates (i.e. ferrous metal plates, e.g., metal plates having iron as a component in the alloy or metal) is configured in two key spots in accordance to a surf stance riding position. One spot is in relative center on the tail section, while the other is centered between the front truck bolt assembly of the skateboard deck (typically of a standard width of about 7.5 inches or smaller). Wider boards of any sport may need to compensate with a variation of placing the metal slightly off center or having a slender oval shaped metal in a horizontal position to keep foot positioning in a preferred desired stance. Thus, the industry can determine with routine experimentation optimal placement of the metal plates in the boards of various sports, along the principles introduced with this invention.
[0033] For example, skateboards and snowboards (and also long skateboards and surf boards) can be designed asymmetrically so that the nose (front) and tail (back) are either a different shape, or extend out more or less than the other from a reference point (such as the trucks in a skateboard). Thus in all cases consideration of the shape of the nose and the shape of the tail need to be taken into account when placing the plates in the boards.
[0034] Also, as all the board sports have different board shapes, placement of the metal plates on the boards for different board sports will likely be slightly different for each board sport, but all the placements can apply the stated objectives articulated here with regard to the placement. Understanding this, and because a given principle of the present invention is that the location of the plates at the nose and the tail should be different for each (even where the nose and tail shape are symmetrically or identically), an option for use of the magnetized board as a non-magnetized system is to simply flip the board around and make the nose the back and the tail the front. This way, even wearing magnetized shoes, the rider can remain unattached to the board. Thus, the system design can further contribute to the use of the board and shoes together in a non-magnetized system when desired, by simply reversing the way one stands on a symmetrically shaped board and using the non-magnetized nose section of the board as a tail. This adjustment however may not be desirable when the front and the back of the board are significantly different as in an “old school” shaped board which is not symmetrical.
[0035] The figures and the description that follows further explain the invention and through this detail, objects and advantages of the present invention will become apparent. The invention is not limited however to specific examples and drawings presented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1A-1D illustrates several views of the shoe or a pair of shoes magnetically attached to a skate board.
[0037] FIG. 2A-FIG . 2 E illustrate the magnetic attachment system having the ability to move the magnet down (on) and up (off) in the shoe. The up (off) position is shown with a plug.
[0038] FIG. 3A-FIG . 3 F illustrates details of magnetic device of FIG. 2 .
[0039] FIG. 4A-FIG . 4 D illustrates the removable magnet attachment system.
[0040] FIG. 5A-FIG . 5 C illustrates a component for storing the removable magnets.
[0041] FIG. 6A-6C depict two different metal plates for affixation to the board and FIG. 6D-6F depict different nose/tail combinations of these plates.
DETAILED DESCRIPTION OF THE INVENTION
[0042] FIG. 1A depicts board 4 with a rider magnetically attached. Shoes 8 with magnets 2 are attached at metal plate 6 on board 4 . Front of board 56 and back of board 58 are also shown. Tail 18 is a region within back of board 58 . FIG. 1B shows board 4 and front of board 56 with left foot of rider. Left shoe 8 having bottom of shoe 28 and magnet on board 4 . The angle shown gives the viewer a sense of the range of motion with regard to heel height that is typical in the system. FIG. 1C shows the bottom 28 of shoe 8 as the back heel lifts off board 4 ; magnet 2 is attached to metal plate 6 at tail 18 of board 4 . FIG. 1D shows board 4 with both shoes 8 attached to the front 56 and back 58 of board 4 . Tail 18 retains right shoe 8 . Magnet 2 is shown coming out of hole 38 from bottom of shoe 28 to contact plate 6 on board 4 . Left shoe 8 having bottom 28 also contacts plate 6 at front of board 56 . A typical ride standing stance for the rider is shown in FIG. 1D where both heels are raised in a maximum angle position before magnets 2 in shoes would detach from board 4 , and shoes 8 are rotated slightly to optimize balance during the ride.
[0043] FIG. 2A-2E depict device 10 , that provides the “on” and “off” option for the magnetized system by controlling whether the magnet is down (“on”) or up (“off”) in the shoe. FIG. 2A shows shoe 8 cut away to reveal magnet device 10 with support rod 14 allowing magnet 2 to be in the down or “on” position 24 .
[0044] FIG. 2B shows magnet device 10 (the embodiment capable of up (off) and down (on) positions) with magnet 2 held by support rod 14 in shoe sole 18 from a top to inward look into the bottom 28 with the toe section being in the forefront. Magnet 2 is held by support rod 14 at magnet hanging member 12 . Here hanging member is part of the magnet casing 32 . Magnet 2 is in up position 22 so that magnet 2 is recessed into the bottom of shoe 28 in an up or “off” position 22 . Screw head 42 on side of magnet device 10 this embodiment is accessible outside the bottom 28 of shoe 8 to manually turn use of magnet device 10 on 24 and off 22 . Plug 44 is shown below the raised magnet 2 , plug 44 flush with the bottom 28 of shoe 8 .
[0045] FIG. 2C shows device 10 inside bottom of shoe 28 in a front toe cutaway diagram. Device 10 is turned on by magnet 2 , which hangs from support rod 14 . Magnet 2 hangs from a hanging member 12 that is attached to the magnet casing 32 between bends in support rod 16 . Magnet 2 is shown in a down position 24 . Screw head 42 is on the left and would be accessible from the outside of the bottom of shoe 28 for adjustment of the magnet up or down.
[0046] FIG. 2D shows a slightly off side view of device 10 in bottom of shoe 28 in the down “on” position 24 . Magnet 2 is flush with the bottom of shoe 8 . Magnet 2 hangs from support rod 14 at hanging member 12 . Screw head 42 is shown on the left side of the shoe for controlling the magnet position.
[0047] FIG. 2E shows bottom of bottom of shoe 28 with device 10 in a down “on” position 24 . Bottom surface of magnet 48 is level with bottom of shoe 28 .
[0048] FIG. 3A shows just device 10 itself in an up position 22 the way it would look if the magnet were to be manually turned “off” by a turn of the screw head 42 on the right. Note that the screw head feature is exemplary, and can be any feature that allows control of the support rod, such as a pin that rotates, etc. Magnet 2 hangs from support rod 14 by a hanging member 12 that is attached to the magnet casing 32 between bends in support rod 16 . Magnet 2 is shown in an up position 22 . Screw head 42 is on the right for adjustment of the magnet up or down. Tubular encasement 26 holds the support rod 14 .
[0049] FIG. 3B shows the same magnet device 10 as shown in FIG. 3A , but in a down “on” position 24 . Screw head 42 is shown on the right for manual adjustment of up or down positioning to turn device on and off. Again, the screw head is only one example of a feature to move the magnet up and down. The feature should be relatively flush with the side of the shoe, but can be any feature that allows manual control of the raising and lowering of the magnet inside the shoe, such as a small handle, a wire protrusion extending from the support rod and adapted to turn clockwise or counter clockwise to raise or lower the magnet. Preferably the feature is flush or nearly flush with the side of the shoe. The slit in the screw head can be large enough for a dime to act as the screw driver in moving the rod and so the magnet one way or another.
[0050] FIG. 3C shows device 10 by itself with the parts exploded. Tubular encasement 26 which is two pieces on the top of the exploded diagram receives the support rod 14 in the middle of the diagram. Between bends 16 in the support rod 14 is the section that the magnet is suspended from which is shown in the bottom of the diagram. Hanging eyelet 12 is integral with casing 32 that surrounds all but the face of magnet 2 . As such, magnet 2 suspends from support rod 14 at the eyelet 12 . The eyelet shape allows magnet 2 to hang and move freely in the shoe. Hanging eyelet 12 is optimally designed to make the lowest clearance for the support rod 14 and thus a preferred shape of the eyelet is more of an arch-like shape than depicted in this diagram.
[0051] FIG. 3D shows three different angle views of device 10 with plug 54 hanging from support rod 14 . Plug 54 has a some ferrous metal on its inside surface to magnetically attach the plug to the magnet. The metal placed on the inside of the plug can be a unitary thin metal plate, but more optimally is two or more pieces of metal spaced apart on the circumference of the inside portion of the plug. Two or more pieces placed at the edge of the plug sphere counteracts the magnetic pole effect that the attraction of magnet 2 for the metal creates. With a single unitary piece, the magnet may attach slightly askew on the plug, but with two or more metal pieces spaced apart on the inside surface of the plug this effect does not occur and the magnet can attach squarely to the plug. Effecting a square placement is important because the hole in the shoe should be a tight fit with the magnet and the plug, and so there is not a lot of room for misalignment in their connection.
[0052] It is also important to determine the thickness of the metal attached to the plug so that the relative force to remove the plug from the magnet is about the force of a finger pull. The force between the magnet and the metal attached to the plug can also be optimized by coating or covering the metal plate with rubber to reduce the potential attraction of the magnet for the metal. Optimal operation of the shoe system requires the user to first elevate the magnet to the “off” or up position 22 and then manually place plug 54 in the hole of the shoe. Magnetic attachment occurs once the plug is in the hole close to the magnet. The shoe can then be worn like a normal, non-magnetic shoe. To return the shoe to use with the magnet, plug 54 is manually removed and the magnet lowered to the on position flush with the bottom of shoe.
[0053] FIG. 3E shows a slight angle change from FIG. 3A . FIG. 3C depicts the bottom surface of plug 54 . FIG. 3D shows plug 54 alone near support bar 14 . Normally magnet 2 is attached to support bar 14 at all times. FIG. 3E shows plug 54 in a side view as it appears when removed from the shoe. It is important to note that the plug and metal can be very thin. FIG. 3F shows the bottom surface of plug 54 .
[0054] FIG. 4A is a view of device 20 (removable magnet embodiment) in bottom of shoe 28 , and shows bottom surface of magnet 48 . Magnet 2 is shown in the down or on position 24 . Support rod 14 is shown transparently inside bottom 28 of shoe. The plug can be substituted for magnet 2 . Support rod 14 is stationary when screwed securely by screw head 42 outside the shoe. FIG. 4B shows magnet 2 and/or plug 44 flush with the bottom of shoe 28 .
[0055] FIG. 4C shows device 20 from an off side view of inside shoe 8 . Support rod 14 is ready to be inserted in bottom of shoe 28 or completely removed. In the middle of bottom of shoe 28 , either magnet 2 or plug 44 can hang from support rod 14 . At far right end support rod 14 makes connection with threaded receptacle 52 . Tubular encasement 26 holds support rod 14 in shoe, and can be made from any durable material, such as, for example, rubber or metal, or other substantially durable materials in order to hold support rod 14 stationary in shoe. FIG. 4D shows device 20 transparently in bottom of shoe 28 , with plug 44 inserted. Threaded receptacle 52 and screw head 42 at opposite ends of rod 14 . Rod 14 housed in tubular encasements 26 within shoe sole.
[0056] FIGS. 5A and 5B depicts magnets 2 stored on a rubberized metal plate storage unit 46 that holds magnets safely outside shoe.
[0057] FIG. 5C shows several pictures of magnet 2 being magnetically held with storage unit for mags 46 . Storage unit for mags 46 consist of a thin piece of steel sandwiched by 2 rubber pieces. Magnets 2 are held in place when not in use on this storage unit 46 by having one magnet 2 magnetically attached to each side. Eyelets 12 for dangling magnets 2 from rod in shoe also shown.
[0058] FIG. 6A shows a 2″ steel plate ( 6 ) that is approx ⅛ ″thick or 12 gauge. The plate has a countersunk hole 36 for screw to be screwed into a slightly recessed board surface shaped to receive the plate. FIG. 6B shows a side view of the screw locations 36 for metal plate 6 which has an oval shape that is shown in FIG. 6C . FIGS. 6D , 6 E, and 6 F each show a different combination of plates in the nose 56 (front) and tail 18 (in back 58 ). FIG. 6C has round plates 6 in the front and tail. FIG. 6D has oval plates 6 in the nose and tail, and FIG. 6E has an oval plate 6 in the nose and an round plate 6 in the tail 18 (preferred).
[0059] A preferred embodiment of the invention is a drop down magnet. See FIG. 2 and FIG. 3 illustrating the drop down magnet device and system. The main features of the illustrated embodiment are a bent metal rod with a dangling magnet suspended on a loop (eyelet) 12 , an outside screw head 42 manually controls movement from an on to an off position (i.e. a down to an up position) and visa versa.
[0060] An alternate embodiment is one in which the magnet is removable (system and device 20 ), such as the design having a straight screw rod (i.e., Steel Screw Out Pin with Interchangeable Shoe Plug), depicted in FIG. 4 . It should be noted that the screw feature is an example of an element to control the removal of the support rod, and the end depicted with a screw head feature, could be replaced with any other feature for releasing the support rod to remove the rod and the magnet (which is underneath the shoe). Optimum placement in the shoe for any of the magnet designs is approximately ½ to ⅔ of the way up from the heel towards the toe, just slightly off center and slightly under the ball of the foot.
[0061] Advantages of the approximate ⅔ placement is advanced trick performance, allowing freedom of movement and usability of the heel. A horizontal position of the support also gives the greatest angling of foot movement while still being held stuck for the longest period of time before breaking free by raising the heel all the way up of an attached foot.
[0062] The quality of the shoe sole and the exact character of the materials that make up the sole are important to the final system. Through extensive prototyping and experimental riding, the inventor determined that the shoe sole must be thick enough to house the magnetic devices described herein, yet flexible and elastic enough to provide the necessary feel and function of a sports shoe. In skateboarding one often “feels” the board more thru the toe and heel section of the shoe. The ideal magnetized skate shoe will probably have more feeling in the toe and heel section, and may not be as thick in those areas or may implement a less dense polymeric material. Ultimately, after much experimentation, the inventor has determined that the type of rubbery sole chosen for the shoe, in the end will have a great impact on how the final magnetized board attachment system will work and feel. Accordingly, the invention includes a shoe that shoe sole with a flexible front and back portion, and a relatively stiffer middle section, where the magnet is placed. The middle section can also be thicker than the front or the back sections to provide a cushion to prevent discomfort on account of the magnet in the shoe. The flexibility in the front and back portions and the stiffness in the middle portion can be provided by varying the quality or character of the polymer material that is used in fabricating the shoe sole. If the device were to be placed in a vertical position within the shoe, the angle of foot movement required for release of the magnetic attachment is less, and therefore that configuration will inhibit the rider from staying on as long as when the support bar is horizontal (across the width) in the shoe. Contact would therefore be broken more frequently during a session. Features such as removal of the magnet and raising or lowering the magnet into position become more difficult to achieve as well.
[0063] A possible advantage of placing the magnet device within the middle of a shoe and having the support in a vertical alignment running from heel to toe in the shoe would be to allow compensation for much younger youthful rider to ride magnetized but release easier. Also with a smaller shoe the working area within the shoe sole is reduced and a vertical mounting position becomes more practical, this taking in the consideration as well that a powerful magnet may be too much for a smaller rider.
[0064] Optimal magnet placement within the shoe and metal placement within the board for these systems has been discovered through experimentation and extensive test riding by a professional skateboard rider.
[0065] The magnets are preferably of neodymium material, which are some of the strongest magnets in the world. The magnets can also be made of more expensive rare earth elements in the same family of compounds such as samarium cobalt. The magnets used in the systems prototyped here are encased neodymium or the equivalent of that magnetic element with the grade range of N38 to N42. The encasement for the magnet is typically metal. The neodymium magnets of this strength generally provide a strength pull factor of approx 75 lbs. each, and at least in a range of pull factor from about 60 lbs to about 90 lbs.
[0066] The optimum range for the diameter of the magnet face is from about 0.5 inches to about 2.5 inches. Preferably, the magnet face has about a 1 inch diameter. The stronger the magnet's pull force is, the more likely the magnet face can be smaller and still work effectively in the system. The combination of specified magnet strength and surface area of the contact face of the magnet allows the shoe to adhere strongly to a magnetized metal plate.
[0067] The magnetized metal plate or component is generally a ferrous metal, e.g. a metal having some iron in it. Any metal capable of being magnetized will work for the function, but ferrous metals are preferred because of the strength of their attraction to magnets.
[0068] All the magnetic systems require the magnetized metal surface to be bare for maximum strength and holding power. Grip-tape and the like, commonly used on boards to eliminate slippage should not be covering the surface of the metal. An exception would be if one wants to weaken the magnetic attachment, then by covering the metal with a thin layer of sticker type tape the attraction to the magnet is reduced.
[0069] The Drop Down Magnet (Bent Steel Rod with Dangling Magnet Suspended on a Loop)
[0070] See FIG. 2A-2E and 3 A- 3 F for visual explanation of the following. Device 10 having support rod 14 of 3/16″ equivalent steel rod is fashioned with a bent configuration in the middle. Although the support rod is shown in these figures here exactly perpendicular to the side of the shoe, and horizontal within the shoe, the support rod can be positioned at an acute or oblique angle relative to the side of the shoe (running from heel to toe). In fact for all devices depicted, although they are shown mounted exactly horizontal in shoe diagrams, in actuality they may be at slight angles within the shoe, for example to accommodate a particular shoe size or shoe design, or the feature that operates the raising and lowering of the magnet within the shoe.
[0071] A 1″ encased magnet 2 with a looping attachment 12 is placed in the middle and allowed to swing from it. The steel rod is loosely encased in metal tubing on each side 26 of the magnet and fixed to the sides of the shoe with a screw head 42 on one end that is accessible on the outside of the shoe. When the screw head is turned it allows the magnet to be up or down, i.e. on or off. In the up position the magnet is off. A rubber plug 54 is provided that can be inserted when magnet 2 is in the up position. The rubber plug 54 has a thin metal ring on one side that makes it stick into the shoe by attaching to the recessed magnet. A turning of the screw makes the rubber plug insert 54 drop back down with the magnet for easy removal of the plug.
[0072] Because magnet 2 can be manually switched from on to off positions, the design offers the flexibility of a dual purpose shoe. Another dual purpose shoe that is possible though less convenient, is shown in the removable magnet embodiment, device 20 ( FIG. 4 ). The removed magnet can be replaced with a plug 44 in the shoe, and the removed magnet safely stored until needed again.
[0073] Straight Steel Screw Pin Rod (Removable Magnet System—Screw Out Pin with Interchangeable Shoe Plug)
[0074] A straight 3/16″ equivalent type of screw rod 14 ( FIG. 4A-4D ) can be taken in and out of the shoe side by screwing/unscrewing the outside screw head 42 . This system would require a shoe plug 44 to fill the hole left in the shoe after removal of the magnet. The system would also require a rubber backed metal disk 46 of approximately 2 inches in diameter (e.g. where the magnets are about 1 inch in diameter) for placing separated magnets on each side of the disk for safe storage.
[0075] The straight rod pin 14 works well for imparting maximum holding power from a dangling magnet held on a rod inserted through the enclosed loop 12 on the magnet casing, while also the rod is floating within the arm couplings 26 . This allows the greatest foot angle before releasing during rider operation. The slot of screw head 42 of this embodiment can be made big enough for a coin to work as a screwdriver.
[0076] For all the described embodiments, support 14 that holds magnet 2 is generally adapted to fit within a shoe 8 having the magnet free-float from the support into a hole 38 in the bottom of the shoe 28 from which the magnet can contact a ferrous metal plate 6 on a board 4 . As described earlier, because of the position of the metal plates on the board, and the position (and size) of the magnet in the shoe, a rider can train, learn and perform tricks on the board. A feature of the system is that the support can be adapted to raise and lower the magnet from within the shoe. The invention also provides a safer magnetized board because while providing increased flexibility for the rider to maneuver when attached to the board, it also provides a safe and easy release by not having the shoe heel magnetized. This allows raising of the heel to an angle just greater than the angle of motion that is allowed for the rider to stay on the board. And because of the ease a non-magnetic heel provides, it also helps to achieve and maintain a more comfortable and balanced stance for riding while turning and performing certain tricks. Other manufactured shoes with double magnets were bulkier and heavier and prohibited ease of foot movements while also making release more difficult deeming the system unsafe.
[0077] The plugs 54 used to guard or cover the magnet surface in the up position can have a thin ferrous metal plate with rubber shields on both sides. A magnet from each shoe of a pair of shoes attaches to a rubber covered plate 54 placed in the hole 38 left after the magnet 2 is recessed. Thus the shoe is converted to normal use when the rider is finished boarding or perhaps wants to ride un-magnetized.
[0078] In addition to providing a magnetized attachment device for board riding, the invention also provides a system of riding a board with the magnetic features described. The system incorporates the attachment of the shoes and the board together to facilitate a new way of engaging in and enjoying board sports.
[0079] A use of the magnetic attachment system is to cross-train in both skateboarding and snowboarding where aerial spins and airborne maneuvers are similarly performed. A snowboarder may want to advance his skills off the snow with a magnetized skateboard and would want to be able to simulate all the tricks a snowboard could do in the snow. An advanced rider would also take note of the ease in which many “stall” type tricks can now be performed on ledges where one may have struggled before to get to the top of the ledge. Now that one is in the air or on a ledge more easily by using the magnet attached system, the rider can start to focus on the feeling of body positioning and balance it would take to do the moves without the use of the magnets. The need for a training tool that provides at least a temporary attachment to the board has been poorly demonstrated by the frequent instances one might see young skateboarders wrapping their feet to the skateboard with duct tape or bicycle inner tubes in order to learn a maneuver.
[0080] Most broadly, the invention is to a system of attaching a rider to a sports board with a magnetized element exposed from the bottom of a rider's shoe, and a magnetized element in a board available for contact on a top surface of the board. Optimally, the magnetized element is at least at a tail of the board (in the back of the board), and if there are two attachment positions, then also at the front of the board.
[0081] These systems can also have various combinations such as: either a magnet in the shoe and metal in the board, a magnet in the shoe and a magnet in the board or metal in the shoe and a magnet in the board. Of these embodiments, the presently preferred embodiment is the combination where the metal is in the board and the magnet is in the shoe.
[0082] The invention is not limited however, to the specific features and combinations of features described herein, but only by the breadth of the claims. The key features in all the systems is the positioning of the magnetized element in the shoe, (i.e., the way it is positioned in the shoe to allow the foot to still move enough to provide the rider with flexibility and balance) and not only where it is placed on the bottom of the shoe, but also how the magnetized element is dangled or loosely configured to hang inside the shoe, and how the shoe can lift away from the magnetized element after the magnetized element has attached to the magnetized element on the board.
[0083] Although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that various alternatives, modifications and equivalents may be used and the above description should not be taken as limiting in scope of the invention which is defined by the appended claims. All cited references are hereby incorporated by reference in their entirety.
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A magnetic device comprises a magnet adapted to suspend free-floating from a hole in a bottom of a shoe, the magnet capable of attaching the shoe to magnetized metal on a sports board. The magnet can be raised and lowered in the shoe and is “on” when in a down position and “off” when in an up position. Switching between “on” and “off” by moving the magnet up or down in the shoe is accomplished manually. When the magnet is up or off the space in the shoe can be occupied with a plug. The design of the attachment system allows a rider optimal freedom of foot movement for doing tricks while attached to the board. The small surface area of the magnet relative to its significant strength, the round contour of the magnet's face, the magnet's suspended free-floating configuration from the support, the position of the magnets on the shoe, and the position of the magnetized metal on the sports board are all factors that contribute to increased maneuverability for the board rider using the invention. Release of the shoe from the board is facilitated by the rider lifting or swiveling a heel to an angle greater than that which allows the magnet to remain attached. The magnetic device and system, provides ideal training for any board sport, and also provides skilled board riders new opportunities to be creative. Tricks thought to be impossible (along with newer undiscovered tricks) become possible with the aid of the invention.
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FIELD OF THE INVENTION
[0001] This invention relates to spectroscopic system and method and particularly to terahertz spectroscopy techniques.
BACKGROUND OF THE INVENTION
[0002] Spectroscopy is one of the main compelling applications of terahertz (THz) radiation. A typical THz Spectroscopy system includes a tunable THz transmitter capable of generating THz radiation for irradiating a sample and a THz detector capable of receiving THz radiation response from the irradiated sample and providing indication (electric signal) of the strength and propagation delay of the detected radiation from the sample. For example, the technique of obtaining information related to terahertz waves that are transmitted through or reflected by a sample is disclosed in U.S. Pat. No. 7,551,269.
[0003] A tunable THz transmission device typically includes two distributed feedback (DFB) lasers and a THz emitter associated with an antenna. One or both of the lasers are associated with a controllable thermo-electric-cooling (TEC) system which controls their operating temperatures and thus their output wavelengths. The lasers are used to illuminate the THz emitter (being typically a photo-conducting element) with a light signal containing an oscillating component at the beat frequency (difference frequency) of the lasers. In the emitter, a THz frequency current is excited while applying D.C. bias to the photo-conducting element which changes conductance at the beat frequency, causing the antenna coupled to it to radiate in the THz band. The frequency of the current in the antenna (and that of the emitted radiation) is the difference between the frequencies of the lasers (beat frequency), and thus tuning the frequency of the emitted THz radiation is achieved by changing the output frequency(ies) of one or both of the lasers. Such photo-mixing based THz emitter is described for example in WO 2007/132459, assigned to the assignee of the present application.
[0004] In a THz detection device (receiver), a responding THz radiation signal, (e.g. reflected, transmitted or scattered wave) from the irradiated sample is incident upon the antenna of the receiving device, which is constructed similarly to the emitting device. This THz signal induces a voltage across the receiving photo-conductor which, in this case, has substantially zero D.C. bias component. The conductivity of the receiving photo-conductor is also modulated at the optical beat frequency by the incident laser light in the same way as the transmitter device is modulated. If the beat frequency is constant, the THz modulation of the conductance interacting with the THz bias created by the signal from the antenna generates a low frequency (e.g. D.C.) signal component proportional to the amplitude of the incident THz wave and dependent on the relative phases of the received wave and the optical beat-frequency modulation. Such arrangement acts as a homodyne mixer in which the modulating optical beat frequency used in the emitter is also used as a reference signal (i.e. reference oscillator modulation) in the receiver. The intermediate frequency is centered around the D.C. (zero frequency), and the arrangement provides coherent detection. The desired signal centered at D.C. can be extracted by using a low pass filter.
[0005] The above is schematically shown in FIG. 1 . Two light beams of wavelengths/frequencies (λ 1 , ω 1 ) and (λ 2 , ω 2 ) respectively are combined by a fiber splitter/combiner to propagate along a combined optical path, and then are split into two light components, each of a beat frequency (ω 2 −ω 1 ) propagating along spatially separated optical paths towards respectively the transmitter- and receiver-antenna units. The light component at the receiver-antenna unit serves as a reference beam or local oscillator modulation. Each of the transmitter- and receiver-antenna units includes photo-conductors with antennas. Radiation emitted by the transmitter-antenna unit is directed (by a reflector) to the sample, and a radiation response of the sample (reflection from the sample) is directed (by another reflector) to the receiver-antenna unit. The latter includes a low-pass filter which operates to extract the desired signal. A photomixing based transceiver system of the kind described above is disclosed for example in U.S. Pat. No. 6,348,683.
[0006] A major disadvantage of such arrangement is associated with the fact that amplifiers exhibit high noise density at low frequencies called “flicker noise”. Accordingly, in order to achieve reasonable signal to noise ratio, the signal (THs radiation incident onto the sample) has to be of as high as possible amplitude, and thus enabling the terahertz signal from the sample to be sufficiently strong when arriving at the receiver. Since the “flicker noise” and a detected signal (resulting from the interaction between the sample's response and reference signals) are in this case occupy frequency band with high density noise, a band pass filter (low pass filter) cannot be effectively utilized to filter out the noise. The severity of the flicker noise phenomenon is illustrated in FIG. 2 which shows noise density for a typical integrated-circuit amplifier (e.g. utilizing MAX4475 amplifier commercially available from Maxim. Integrated Products Inc). It may be seen that the noise density is rising rapidly as frequencies approach D.C. At 10 Hz the density is more than five times the density at 10 kHz, and at 1 Hz the density will be very much larger, probably several hundred time the density at 10 kHz.
[0007] Another technique of the kind specified is disclosed in U.S. Pat. No. 7,687,773. This technique relates to sub-millimeter wave frequency heterodyne imaging systems, more specifically, to a sub-millimeter wave frequency heterodyne detector system for imaging the magnitude and phase of transmitted power through or reflected power off of mechanically scanned samples at sub-millimeter wave frequencies.
GENERAL DESCRIPTION OF THE INVENTION
[0008] There is a need in the art in optimizing high-frequency spectroscopy (THz range spectroscopy). The present invention meets this need by providing novel methods and devices for use in a high-frequency spectroscopic system enabling to improve signal to noise ratio of the system operation.
[0009] The main idea of the invention consists of providing a desired (e.g. desirably high) frequency difference between responding radiation coming from a sample under inspection and reference radiation when both simultaneously arrive to an antenna receiving unit. To this end, the invention takes an advantage of frequency sweeping that is to be used in spectroscopy. This is associated with the following:
[0010] In spectroscopy applications it is common to sweep monotonically the frequency of the emitted radiation across a certain desired frequency range. As indicated above, in cases where two or more laser beams are used for generating a high frequency (THz range) radiation (e.g. by photomixing), frequency sweeping is carried out by sweeping the frequency output of at least one laser source, or both of them in a predefined rate(s).
[0011] Spectroscopic measurements in the THz regime are performed by irradiating an inspected object with THz radiation and detecting a THz radiation response from the object. In the following description, the THz radiation irradiating the sample/object is referred to as inspecting radiation, while the part of the inspecting radiation reflected from or transmitted through the object and detected by the detector/receiver is sometimes referred to as responding radiation. As indicated above, typical detection devices for THz spectroscopy use homodyne detection in which the responding radiation from the object (sample) is mixed with a reference radiation, which has properties corresponding to the inspecting radiation to generate a detection signal (e.g. an electric/electromagnetic signal). The reference radiation may be for example a radiation portion, sourced together with the inspecting radiation having similar properties, and transmitted directly to the receiver/detector (not through the inspected object/sample). The detection signal generated by the mixing of the reference radiation and the responding radiation can be more conveniently processed as it has a lower frequency than that of the responding radiation. This enables determination of the spectral properties, determining physical and/or chemical properties/conditions of the object, from amplitude and phase measurements, as being functions of frequency of the inspecting radiation, based on detection of the responding radiation.
[0012] Thus, the homodyne detection is based on that the reference signal and the inspecting radiation for irradiating the object are originated by the same source(s). Reference radiation may be generated in the transmitter by splitting the laser output, bearing the beat frequency signal, into two portions. One portion is then used for generation of inspecting THz radiation and the other for creation of the reference signal with which to coherently detect the responding radiation.
[0013] Generally, at the detector, the instantaneous frequencies of the reference radiation and the inspecting radiation arriving as response from the object/sample are different. This is because of the frequency sweeping carried out in the THz generator (emitter), and because of a time delay between the arrivals to the detector of the responding radiation (radiation response from the object) and the reference radiation the origination of which have been concurrently initiated at the emitter (i.e. have the shared laser source). This time delay may, for example, be a result of different propagation path lengths traversed by the inspecting and reference radiation components to the receiver, and is also associated with a delay in transit of the inspecting/responding radiation due to interaction with the sample. After mixing of the responding radiation with the reference radiation (homodyne detection), and possibly also after suitable band pass filtering, the resultant detection signal has an intermediate frequency component, which is of the order of the frequency difference between the responding and reference signals and typically has (according to the conventional techniques) low frequencies centered around zero frequency.
[0014] It should be noted here that for the purposes of the present application the terms intermediate frequency, intermediate frequency component and homodyne frequency used herein generally refer to the frequency of a signal resulted from mixing of the detected signal from the sample with the reference signal/radiation. Also, is should be noted that, differently from typical homodyne detection systems, in which such intermediate frequencies are generally centered around the zero value, the homodyne detection effect utilized in the invention provides for intermediate frequencies which are not centered around zero Hertz value and which therefore are less affected by noise effects such as the “flicker noise”.
[0015] Let us consider for example the use of a THz generator having substantially constant frequency sweeping rate β for generating the inspecting and reference radiation. Here, β is the time derivative of the frequency of the transmitted THz radiation in cycles per second per second, and is also referred to herein as frequency variation rate. For such THz generator, a frequency difference between the detected response radiation and the reference radiation is given by β· (τ being the time lag between the receipt of the reference radiation and the response radiation at the detector). In typical THz spectroscopy, β may be of the order of 1 THz/sec and τ may be of the order of nanoseconds. Accordingly, in this example the frequency difference is 1 kHz per nanosecond, i.e. 1 THz/sec. According to the conventional techniques, this frequency offset effect is compensated by adjusting the reference and inspection/response path lengths (e.g. through controlled delay of the reference radiation component) so that the differential delay is artificially calibrated to zero (τ=0).
[0016] As an alternative to adjusting the delay to zero, the spectroscopy may be accomplished by step-wise excursion of the interrogating frequency (frequency of the radiation produced by the system, i.e. inspecting and reference), rather than continuous scanning. In this implementation, the frequency is held constant (i.e. β=0) during a measurement interval. However, this constraint imposes quantization on the frequency variable which may be undesirable when searching for fine-grain features in the spectral response. In addition, operating in discrete (step wise) frequency methodology, a fairly long transient time for frequency settling is generally required at each frequency step which contributes to a substantial increase in the time required for a spectroscopic measurement of a sample.
[0017] The present invention provides for resolving this deficiency, so that there is neither a need to match time delays in the arrival of reference and interrogation/responding signals to the receiver (controlling the optical paths), as compared to the conventional techniques (e.g. described in U.S. Pat. No. 7,551,269, nor a need to constrain the method of scanning. The invention permits the use of continuous scanning, while facilitates fast scanning and removes the need to match delay paths.
[0018] The present invention also provides for exploiting the coupling between frequency change rate and delay to enhance the measurement quality. This is achieved by providing higher sweeping rate beyond that needed for basic spectroscopy.
[0019] In order to allow accurate spectroscopic measurements/detection, the frequency (and possibly also the phase) of the reference radiation, which is mixed with the radiation response, should correspond to the THz frequency from the THz transmitter. Accordingly, the reference signal and inspecting radiation for irradiating the object are originated by the same light source; the output of the light source (laser based light source) is split into two portions. The first portion is used to generate THz range radiation which is directed to propagate to the detector via the interaction with the sample. The second portion is utilized for producing/transmitting reference radiation directly to the detector.
[0020] According to the invention, at the detector, the instantaneous frequencies of the reference radiation and the inspecting radiation arriving as response from the object are different. This is because of the frequency sweeping carried out in the THz generator (emitter), and because the path lengths of the inspecting and reference radiation components need not be adjusted to reduce a time delay between their arrivals to the detector. Accordingly, the inspecting radiation (radiation response from the object) and the reference radiation components that concurrently arrive at the detector are those that had been originated/initiated at the emitter at different times, and therefore have different frequencies due to the frequency sweeping carried out in the emitter. This time delay results from the different optical path lengths traversed by the reference radiation and the inspecting radiation interacting with the sample. After mixing of the inspecting radiation with the reference radiation (homodyne detection), and possibly also after suitable filtering, the resultant detection signal has an intermediate frequency component of the order of the frequency difference between the inspecting and reference signals which is in turn proportional to both the time delay and the frequency sweeping rate.
[0021] Turning back to the example above and considering a THz generator with frequency sweeping rate β of the order of 1 THz/sec and a time lag τ of the order of nanoseconds between the arrivals of inspecting and reference radiation components at the detector, the frequency of the detection signal (the beat frequency obtained after mixing the inspecting and reference radiation), is of the order of several KHz, e.g. 5-100 KHz.
[0022] It is desired to increase the frequency difference (i.e. the intermediate frequency) between the reference and inspecting radiation components simultaneously arriving to the detector, such that a higher homodyne frequency (i.e. intermediate frequency) is obtained. This is because using larger frequency difference allows higher signal to noise in the detection signal and because the noise density (flicker noise) is smaller for higher frequencies.
[0023] Moreover, higher intermediate frequencies are also desired since they allow improved range discrimination (higher range resolution/depth resolution) of the sample. The range resolution that can be obtained by spectroscopic detection is given by
[0000]
resolution
=
c
2
β
*
τ
,
[0000] where c is the speed of light, τ is a time delay between the reference and inspecting radiation arriving at the detector and β is the frequency sweeping rate. Improving the range discrimination enables better filtration out of noise and sporadic radiation, such as reflections, from the detection signal, thus also enabling to increase the signal to noise of the spectroscopic inspection. With regard to depth profiling application of this invention, it should be noted that in order to get a phase reference (i.e. a location inside the sample corresponding to the detected response), the free space path is appropriately calibrated prior to actual measurements. The present invention is based on the understanding that increasing the frequencies of the detection signal (i.e. a frequency difference between the frequencies of the reference and responding radiations at the receiver) can be achieved by varying/increasing either the difference between the optical path lengths traversed by the reference and inspection radiations until arriving at the detector (thus varying the time lag between the arrivals of said radiations at the detector), or by increasing the frequency sweeping rate β of the THz generator. According to the invention, increasing the frequency difference between the reference and inspection radiation is achieved by providing an optical drive module which is adapted for fast wavelength sweeping of one or both of the DFB lasers facilitating to achieve higher frequency sweeping rates of the THz generator.
[0024] As noted above, THz emitters (radiation generators) typically include an optical drive associated with two or more lasers. THz radiation is generated by photomixing of the output beams from the two or more lasers such that THz radiation has a continuous wave (CW) form with the frequency equal to the beat frequency (frequency difference) of the lasers' output beams. Typically, at least one of the lasers is a DFB laser and thus a control over the frequency of the THz radiation, needed for spectroscopic applications, may be achieved inter alia by utilizing thermo-electric-cooling (TEC) systems for adjusting/controlling the temperature and thus output wavelength(s) said at least one laser. In this manner, the frequency of the output THz radiation can be swept continuously by gradually changing the operating temperature of said at least one laser (more specifically by changing the temperature of the active region of the laser diode, e.g. substantially linearly with time). In many cases, the wavelengths of two DFB lasers of the optical drive are swept in opposite directions, e.g. by heating one laser while cooling the other, thus increasing the rate of sweeping of the THz output frequency and the overall frequency sweeping range.
[0025] Hence, according to the conventional approach, the frequency sweeping rate β is strongly dependent on the heat pumping rates of the TEC systems and also on the coupling of such TEC systems with the active region of the laser diodes. Changing the temperature of a laser is a relatively slow process which rate is limited by the ability of the TEC systems to pump heat from the active region of the laser diode (which is small relatively to the TEC system). This, in turn, practically limits the frequency sweeping rate β up to the order of 1 (THz/Sec) even when good TEC systems are used.
[0026] According to the invention, sweeping of the laser(s)' wavelength/frequency may be performed by utilizing temperature variations of the lasers active region as well as by varying/modulating other operational parameters of the optical drive (or of the lasers) to obtain frequency modulated continuous wave (FMCW) output signal/light-beam from the optical drive. The frequency (the baseline) of the signal is swept gradually by the temperature variation while the frequency modulation can be achieved for example by modulating the current through the laser diode to affect its output wavelength or by utilizing electro-optical in the path of the output beam of the laser for modulating its wavelength.
[0027] Indeed, the common techniques for exercising variation of the output wavelength of a light source/laser include controlling/adjustment of the temperature and/or the current of the light source. However, it should be noted that some aspects of the invention, and specifically those aspects relating to the utilization of fast frequency sweeping rates for the purpose of reducing measurement noise or improving the range resolution (depth resolution), are not limited to the specific technique by which fast frequency sweeping rates are obtained. Accordingly, other techniques, which are currently known or which will be applicable in the future, for varying the output wavelength/frequency of light source might also be used for implementing the technique of the present invention and providing high rate frequency sweeping and/or modulated frequency sweeping without departing from the scope of the present invention.
[0028] Thus, according to one broad aspect of the invention, there is provided a method for use in spectroscopic measurements of a sample. the method comprising: generating inspecting and reference electro-magnetic radiation components of substantially the same frequency contents being swept according to a predetermined frequency pattern, directing said inspecting and reference radiation components to a detector along first and second different paths respectively, the sample being located in the first path (allowing interaction of the inspecting radiation component with a sample) to thereby induce a frequency difference (e.g. a predetermined frequency difference) between a frequency of the inspecting radiation component and the reference radiation component interacting at the detector. A signal resulting from the interaction between the inspecting and reference radiation components is thus indicative of one or more properties of the sample at a location where the inspecting radiation interacts with the sample.
[0029] According to some embodiments of the invention the frequency difference between a frequency of the inspecting radiation component and the reference radiation component interacting at the detector, is induced by controlling at least one of the predetermined pattern and the propagation of the inspecting and reference radiation components to the detector. Also, the predetermined frequency pattern may be selected in order to provide at least one of the following: (i) the frequency difference between the reference and inspecting radiation component at the detector, being highly sensitive to a difference between said first and second paths thereby increasing spatial resolution of detection of a depth location of the interaction between the inspecting radiation component and the sample; and (ii) the frequency difference between the reference and inspecting radiation component at the detector, being within a certain frequency range thereby increasing signal to noise ratio of detection of said one or more properties of the sample.
[0030] Preferably, at least one of the inspecting and reference optical radiation components is formed by one or more pairs of interacting light beams. The frequency of the at least one respective radiation component is thus a beat frequency of said interaction.
[0031] The controlling of the propagation of the inspecting and reference radiation components to the detector is such as to allow free propagation of the reference radiation component to the detector (namely propagation independent of a propagation time of the inspecting radiation to the detector), thereby inducing said predetermined frequency difference and enabling to desirably increase said frequency difference to thereby increasing signal to noise of the measurements.
[0032] The controlling of the pattern of the beat frequency sweeping comprises concurrently affecting a first, global frequency sweeping rate during a certain time period and a local modulation of the frequency sweeping with a second higher sweeping rate.
[0033] According to another broad aspect of the invention, there is provided a method for electromagnetic frequency sweeping of output light from a light source comprising one or more laser diodes, the method comprising: gradually changing an operational temperature of an active region of at least one laser diode thereby causing a substantially monotonic change in the frequency output of the laser diode; and concurrently modulating an electric current through at least one of the laser diodes thereby inducing additional frequency sweeping pattern in the frequency output of the laser diode.
[0034] Preferably, a first characteristic time scale of said monotonic change in the frequency output is longer than a second characteristic time scale of the frequency modulation. The frequency modulation thereby presents a sequence of local changes in the frequency output during a global change corresponding to said monotonic change in the frequency output.
[0035] According to another broad aspect of the invention, there is provided a method for use in frequency modulated continuous wave (FMCW) spectroscopy, the method comprising producing FMCW electromagnetic radiation by interacting light beam output from at least two laser diodes and gradually changing an operational temperature of an active region of at least one of said laser diodes thereby causing a substantially monotonic change in the frequency output of said at least one laser diode and concurrently modulating an electric current through at least one of the laser diodes for inducing a frequency modulation in the frequency output of the laser diode, thereby increasing a span of frequency gradient of said electromagnetic radiation during the measurements allowing higher signal-to-noise ratio of the measurements.
[0036] An operative frequency of the FMCW spectroscopy may be in a THz regime. The interaction of the light beams from said at least two laser diodes generates at least one FMCW electromagnetic radiation beam in a near THz frequency range.
[0037] More specifically, in some embodiments of the invention, the method includes: (i) irradiating the sample with an incident beam being a first THz-range FMCW beam to cause a THz radiation response of the sample; (ii) causing an interaction between the response beam of the sample and a certain reference beam being a second THz-range FMCW beam time shifted from the corresponding first FMCW beam, and (iii) detecting an electromagnetic signal resulting from said interaction and having a frequency corresponding to the time shift between the first and second beams and to said frequency modulation of the laser diode.
[0038] Generation of the at least one FMCW electromagnetic radiation beam in a THz frequency range utilizes generation of said incident and reference beams, while performing continuous frequency sweeping with certain sweeping rate β. The parameter β is controlled by temperature variation of at least one of the lasers or by current modulation induced in at least one of the lasers, or preferably by combination of both the temperature and current variations. Temperature variation is a relatively slow process, while the current modulation, which may be achieved at electronic speeds, is a quicker one. For example, the scale factor pertaining to temperature controlled frequency variation applied to a laser with wavelength of about 800 nm is approximately 30 GHz/deg.K. Utilizing the electric current modulation, the scale factor relating frequency variation to laser drive current is approximately 1.6 Ghz per mA.
[0039] According to the invention, “slow” temperature variation may be used for spectroscopic coverage, while fast current modulation may be used simultaneously to on the one hand improve the radial resolution (depth resolution) of the spectroscopic measurements beyond that achievable with slow frequency sweeping rates (e.g. utilizing frequency sweeping based temperature control alone), and on the other hand improve the signal to noise of the measurement due to higher intermediate homodyne frequency. In this case the laser will be driven by modulated current waveform (e.g. sinusoidal/saw-tooth/triangular etc'), while the temperature may be varied simultaneously in a linear fashion.
[0040] According to yet further broad aspect of the invention, there is provided a method for use in spectroscopic measurements of a sample, the method comprising: generating inspecting and reference radiation components corresponding to respectively first and second pairs of light beams of the same beat frequency contents being swept according to a predetermined pattern and directing said inspecting and reference radiation components to a detector along first and second different paths, the sample being located in the first path, said pattern being selected so as to induce a desired frequency difference between a frequency of the inspecting radiation component and the reference radiation component interacting at the detector.
[0041] The invention also provides a spectroscopic measurement method comprising: generating inspecting and reference radiation components corresponding to respectively first and second pairs of light beams of the same beat frequency contents being swept with a certain sweeping rate, and directing said inspecting radiation component to propagate to a detector along a first path passing through a sample and directing the reference radiation component to the detector along a second path, the first and second paths being such that the inspecting and reference radiation components interacting at the detector correspond to light beam pairs generated at different times thereby inducing a desired frequency difference between the interacting inspecting and reference radiation components.
[0042] According to yet another aspect of the invention, there is provided a system for use in spectroscopic measurements of a sample, the system comprising: a radiation transmitter unit configured and operable for generating inspecting and reference electro-magnetic radiation components (e.g. optical or quasi-optical or THz range radiation) of substantially the same frequency contents, and for sweeping said frequency according to a predetermined frequency pattern; and a detector located in a first path of the inspecting radiation components after passing through a sample and in a second path of the reference radiation component directly propagating from the transmitter unit to thereby induce a frequency difference (e.g. being predetermined difference) between a frequency of the inspecting radiation component and the reference radiation component interacting at the detector, a signal resulting of interaction between said inspecting and reference components being indicative of one or more properties of the sample at a location where said inspecting radiation interacts with the sample.
[0000] According to some embodiments of the invention the system is configured to adjust/tune/control the frequency difference between the components of the inspecting and the reference radiation at the detector, by controlling at least one of the predetermined frequency pattern and the propagation of the inspecting and reference radiation components to the detector. Additionally or alternatively the predetermined frequency pattern may be selected such that the frequency difference, between the inspecting and reference radiation components at the detector, is highly sensitive to a difference between the first and second paths (thereby increasing spatial resolution of detection of a depth location of the sample portion being inspected) and/or it is within a certain frequency range which is selected in order to increase the signal to noise ratio of detection of one or more properties of the sample.
[0043] According to yet another broad aspect of the invention there is provided a system for sweeping of the output frequency of a light source comprising one or more laser diodes, the system comprising:
[0044] a frequency sweeping module adapted for affecting gradual change of one or more operational parameters of a light source to thereby cause gradual sweeping of the frequency of the light source across a certain frequency range; and
[0045] a frequency modulation module adapted for modulating one or more operational parameters of the light source to induce modulation in the frequency of light source.
[0046] Said one or more laser diodes may comprise one or more DFB lasers; and said gradual change of said one or more operational parameters may comprises a gradual change of the operational temperature of an active region of at least one DFB laser affecting substantially monotonic sweeping of the frequency of said at least one DFB laser. The frequency sweeping module may comprise at least one temperature control unit connectable with at least one TEC system thermally coupled with said at least one DFB laser; said temperature control unit is configured and operable for controlling the operation said at least one TEC system.
[0047] The frequency modulation module may comprising at least one current control unit connectable to at least one laser diode and configured and operable for modulating an electric current flowing through said at least one laser diode to thereby induce modulation in the frequency of said at least one laser diode.
[0048] Output radiation from said light source may be obtained by coupling light beams from said one or more laser diodes. The light source may comprise two laser diodes and the frequency sweeping module may include at least one temperature control unit. For example, two temperature control units may be used and may be associated respectively with two laser diodes; the frequency sweeping module is adapted in such case to operate said two temperature control units to change the temperatures of the laser diodes in opposite directions.
[0049] The frequency modulation module may also include one or more current control units associated with at least one of the laser diodes. For example, two current control units associated respectively with two laser diodes. The frequency modulation module may be adapted to operate said two current control units to modulate the currents through the respective laser diodes in opposite directions.
[0050] As indicated above, in some embodiments of the invention, a first characteristic frequency variation rate in the output frequency of the light source obtained by operating said frequency sweeping module is lower than a second characteristic frequency variation rate obtained by operating said frequency modulation module. The modulation in the frequency of light source thus presents a sequence of local changes in the frequency output during a global change corresponding to said gradual sweeping in the frequency output.
[0051] The invention in its yet another aspect provides a high-frequency spectroscopy system, the system comprising:
[0052] a radiation generator for generating an inspecting radiation and a reference radiation of the same properties;
[0053] a frequency sweeping module associated with said radiation generator for inducing frequency modulation in said inspecting and reference radiation components, said frequency modulation having a global frequency sweeping rate and a local frequency sweeping rate corresponding to desired frequency and radial resolution to be obtained in a spectroscopic measurement.
[0054] Such system comprises or is connectable to a radiation receiver unit configured and operable for mixing the reference radiation component and a responding radiation component being a reflection or transmission of the inspecting radiation component from or through the sample. The receiver unit is configured and operable for determining a frequency difference between the reference and responding radiation components being mixed and utilizing said local frequency sweeping rate to identify a in-depth location, at said radial resolution of a sample, associated with said received responding signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
[0056] FIG. 1 shows an example of an antenna system, for use in spectroscopy according to the conventional approach;
[0057] FIG. 2 illustrates noise density characteristics of an amplifier which corresponds to the flicker noise effect;
[0058] FIG. 3 illustrates schematically a THz spectroscopy module according to the invention.
[0059] FIG. 4 is a flow diagram of a method according to the invention for sweeping the output wavelength of a light source such as DFB laser.
[0060] FIGS. 5A and 5B illustrate graphically two time profiles of THz frequency sweeping, where FIG. 5A shows the THz frequency sweeping obtained by changing the temperature of the light source from which the THz radiation is generated, and FIG. 5B is a time profile of FMCW radiation obtained according to the invention by sweeping the THz frequency while changing both the temperature and the current of the light source.
[0061] FIG. 6 . is an example of a light coupling assembly used in the present invention for receiving and mixing light beams from two lasers and providing two output light beams having substantially similar spectral contents and energy.
[0062] FIGS. 7A to 7D show few examples of possible current modulation schemes which can be used in accordance with the present invention for generating frequency modulated output laser beams.
[0063] FIGS. 5A to 5C describe the delay-induced frequency offset problem resulting from the conventional approaches illustrated in FIGS. 1 , 3 and 4 .
[0064] FIG. 9 exemplifies a signal detection process according to some embodiments of the invention for implanting the depth profiling.
[0065] FIG. 10 illustrates schematically an arrangement suitable for depth profiling of the invention.
[0066] FIG. 11 shows an example of the invention for achieving global and local frequency sweeping rates.
DETAILED DESCRIPTION OF EMBODIMENTS
[0067] Reference is made to FIG. 3 illustrating an example of a THz transceiver 100 according to an embodiment of the present invention including a THz transmitter 110 and a detector (receiver) 120 . In the present example, the transceiver 100 is configured and operable for carrying out accurate spectroscopic measurements of a sample/object in the THz frequency regime. The THz transmitter 110 is adapted to generate THz radiation with high frequency-sweeping rates β, and to transmit at least a part of this THz radiation, inspecting radiation IN, towards the object/sample O under inspection, and reference radiation RR towards the THz detector. The THz detector 120 is capable of receiving and detecting high-frequency modulated signals, being therefore capable of exploiting the high frequency-sweeping rate β for generating a detection signal HS (e.g. homodyne signal) of relatively high frequencies indicative of the response radiation RS emanating from/through the object in response to its irradiation. The relatively high frequencies of the signal HS result with high signal to noise ratio and with improved range resolution of the spectroscopic measurements.
[0068] The THz transmitter 110 includes an optical drive (light source system) OD and a THz emitter EM optically coupled thereto. The THz emitter EM is configured and operable for generating THz radiation by mixing input light beams, which are light signals emanating from the optical drive OD. The optical drive includes at least two light sources, generally designated L 1 -L n , which may be light emitting elements themselves or light input ports associated with remotely located light emitting elements (e.g. via optical fibers), and also includes an optical drive controller ODC. The optical drive OD is configured and operable to generate at least two light beams, LB 1 and LB 2 (typically in the IR wavelength range), which are directed onto an active region of the THz emitter EM (which serves as a photomixer), and thus generate an electric current/EM-field in the THz band.
[0069] The optical drive controller ODC is configured and operable for controlling the operational parameters of at least one light source (e.g. L 1 or L 2 ) such as to allow high rate wavelength sweeping of the at least one output light beam (e.g. LB 1 or LB 2 ). Utilizing the optical drive controller ODC, the transmitter 110 is capable of sweeping the frequency of the transmitted radiation with high frequency-sweeping rate β and across a desired THz frequency range suitable for spectroscopic measurements.
[0070] Detector 120 is configured for receiving and detecting (e.g. homodyne detection) of the radiation response RS by utilizing mixing of the radiation response RS with reference radiation RR which is received from the transmitter 110 (e.g. directly). As a result of such mixing, an output (homodyne/intermediate) signal is generated, by the detector, containing intermediate frequencies of the differences between the frequencies of the mixed reference radiation RR and radiation response RS.
[0071] As noted above, with the conventional approach for executing frequency sweeping of the laser diode output, i.e. by temperature changes of the active region of the diode, it is impractical to provide a constant high sweeping rate β of the high-frequency signal across the full frequency range of THz spectroscopy. However, performing THz spectroscopy with high frequency sweeping rates β would be advantageous in terms of measurement/detection accuracy.
[0072] The present invention provides a solution for the above by utilizing a first, substantially steady/monotonic sweeping of the THz radiation with a frequency sweeping rate β 0 and utilizing a second modulated sweeping with higher rate β 1 . Thus, according to the invention an effective modulated frequency sweeping rate β can be obtained for example in the form of
[0000] β=β 0 +β 1 ( t )
[0000] where t is a time parameter, β 1 (t) is the sweeping rate which is a non-linear function of time to generate desired sweep rate alternation during said monotonic sweeping with the rate β 0 .
[0073] This can be achieved by configuring the optical drive controller ODC with the ability to apply a monotonic/constant wavelength sweeping rate to one or more of the light sources L 1 -L n and to apply an additional, modulated wavelength sweeping to at least one of the light sources, which may be the same or different from said at least one light source. To this end, the optical drive controller ODC includes a frequency sweeping controller FS configured to induce a first monotonic sweeping of the output wavelength from one or more of the light sources L 1 -L n by controlling at least some of their operating parameters and a frequency modulation controller FM affecting a modulation of the output beam wavelength of (said) one or more of the light sources L 1 -L n by controlling the same or different parameters of their operation. It should be noted that the operating parameter(s) of the light source to be controlled may be that of the light emitter itself or of the light input port and/or associated light guide (generally light propagation media).
[0074] As noted above, the transmitter is configured and operable for generating reference radiation RR and transmitting it towards the detector. The reference radiation RR is mixed at the detector with the radiation response RS from the object which results in the detector output signal HS (being the homodyne/intermediate frequency signal).
[0075] The reference radiation RR typically includes a portion of the light beam(s) emerging from the optical drive OD. Reference and inspecting radiation portions are obtained by splitting the light beams from the optical drive OD into the reference radiation portion and the inspecting radiation portion and directing the reference portion to the detector 120 and the inspecting radiation portion towards the emitter. In this case, THz frequency electric field (i.e. reference oscillator) is generated at the detector 120 by mixing the light beams of the reference radiation portion.
[0076] Generally the reference radiation RR and the inspecting radiation IN are sourced concurrently from the same origin (e.g. by light beams from the optical driver OD or THz radiation from the emitter EM). Accordingly, at the time these radiations are generated/emitted from the transmitter 110 , they are associated with similar THz content (frequencies/modes). It should be understood that THz content refers to the frequencies/modes and possibly also the respective intensities which are included in the reference RR and in the inspecting IN radiation or which can be generated therefrom, e.g. by mixing.
[0077] However, the portions of the inspecting IN and reference RR radiation which arrive concurrently to the detector 120 , correspond to light beams originated at different times from the transmitter 120 and are thus associated with different THz content (i.e. because there may be a time delay τ between arrivals of concurrently generated beams at the transmitter due to a difference ΔR in the length of their optical path to the detector). This different THz content of the inspecting IN and reference RR radiation gives rise (or at least increases) the frequencies of the output signal HS which is obtained after mixing of those radiations at the detector.
[0078] The difference in the frequency contents of the reference RR and inspecting IN radiations, and accordingly the frequency of the output signal HS, is of the order of the frequency sweeping rate β multiplied by the time delay τ, i.e. ˜β·τ. Frequency sweep due to temperature variation is fairly coarse and achieves relatively big frequency change over the temperature range but fairly slow. Considering frequency sweeping rates β 0 of this order and considering a difference ΔR between the optical paths of the reference RR and inspecting IN radiation of about few meters (the inspecting radiation IN propagates 1 m from the transmitter 110 to the object O and 1 m from the object O to the detector 120 while the reference radiation RR propagates a negligible distance), a time delay τ of a few nanoseconds is obtained between the reference RR and inspecting IN radiation and accordingly frequencies of the order of tens of KHz are obtained in the output signal.
[0079] As noted above, accurate spectroscopic measurement, namely having high SNR in the output signal HS and/or high range resolution of the measurements, can be obtained when the output (homodyne) signal HS is of relatively high output frequencies, e.g. in the range of hundreds of KHz and up to few MHz and above. The optical drive controller ODC of the invention facilitates high sweeping rates β of the THz radiation from the transmitter by controlling/modulating one or more operational parameters of the light sources L 1 -L 2 such as their operating current and temperatures. As a result, an output signal HS of higher intermediate frequencies can be generated at the detector, and thus accurate spectroscopic measurements in the THz regime can be obtained. This will be described more specifically further below.
[0000] Generally, conventional DFB lasers have frequency coverage of about 1.5 THz (the output frequency of the laser can be swept by about 1.5 THz). Accordingly, photomixing the output light beams from two DFB lasers allows generating THz radiation which can be swept to cover a range of about 3 THz.
[0080] According to the invention, more than two light sources/lasers might be effectively utilized for providing spectroscopic measurements with broad frequency coverage in the THz regime. In this case, at least two of the multiple lasers have different frequency output ranges. By photomixing different pairs of lasers (e.g. successively) while sweeping the output frequencies of each photomixed pair, different frequency ranges in the THz regime can be covered thus providing a broader total frequency coverage.
[0081] In the embodiment of the invention illustrated in FIG. 3 , an optional frequency coverage controller FC is included being configured and operable for selecting and operating different pairs of the light sources L 1 -Ln successively, resulting in different beat frequencies. Those different beat frequencies are then swept by the utilizing at least one of the frequency sweeping and frequency modulation controllers to cover different THz ranges (optionally complementary ranges) thereby allowing THz spectroscopy within a broad frequency/spectral range.
[0082] For example, utilizing three DFB lasers, photomixing of the first and second lasers can be used to sweep the beat frequency (i.e. the THz frequency) within a first THz range which may be about 3 THz wide. Then, the first laser may be photomixed with a third laser, having output frequency range different from the second laser, and thus the resulting beat frequency can be swept within a second THz range different from the first THz range (first and second ranges being possibly complementary ranges). As also the second range may have width of up to about 3 THz, total frequency coverage in the THZ regime of about 6 THz can be obtained. Even broader frequency coverage can be obtained for example by utilizing additional lasers (more than three) and by coupling different pairs of these lasers at each specific time period to allow sweeping of the beat frequency within multiple THz ranges.
[0083] Reference is made to FIG. 4 exemplifying a flow diagram 200 of a method according to the invention for controlling the operation of one or more laser diodes, such as DFB lasers, to generate an output laser beam with fast variation of its wavelength. The method can be implemented in an optical drive OD (i.e. by the optical drive controller ODC) illustrated in FIG. 3 and can be used to facilitate the generation of frequency modulated continuous wave (FMCW) having high rate of frequency sweeping/variation THz by THz generators/emitters.
[0084] Wavelength/frequency sweeping of a laser diode output with high sweeping rates is achieved according to this method by concurrently and/or interchangeably carrying out the following operations:
[0085] In a first operation 210 , at least one operational parameter of the laser diode, such as its operational temperature (e.g. the temperature of its active region) is controlled (controllably varied) for maintaining continuous sweeping 210 the laser diode wavelength for example for providing a monotonic/steady wavelength sweeping with relatively fixed sweeping rate. With respect to the system of FIG. 3 , this operation might be performed by the frequency sweeping controller FS to control the operational temperatures of one or more of the lasers for example by controlling the operation of thermo-electric cooling (TEC) systems (TEC) coupled therewith.
[0086] In a second operation 220 , the same or other parameter of the laser's operation is controlled for modulating the laser's wavelength in time. This can be for example achieved by applying modulation to the current through the laser diode thus affecting a modulation of its output. With reference to the FIG. 3 this operation might be performed by the frequency modulation controller FM.
[0087] By changing the operational temperature of a DFB laser, its output frequency can be changed at a rate of about 1.5 THz/sec. This can be achieved for example by heating/cooling the lasers utilizing a TEC system with high heat pumping rate (for example the TEC system disclosed in a co-pending U.S. application Ser. No. 61/292,649).
[0088] FIG. 5A illustrates graphically the sweeping of THz radiation frequency as obtained by photomixing of light outputs of two DFB lasers which operational temperatures are changed in time in opposite directions. Graph G 1 illustrates the evolution of THz frequency as function of time while sweeping of the THz radiation frequency across a range of about 300 GHz-3.5 THz. The slop of graph G 1 designates the sweeping rate β which is substantially constant in this case. Frequency sweeping is obtained by applying heating and cooling respectively to the two DFB lasers (their active regions) such that their wavelengths are swept to opposite directions. Since the temperature variation of the lasers is a gradual and relatively slow process, relatively low frequency sweeping rate β=˜3 THz/sec is obtained.
[0089] Turning back to FIG. 4 , in order to increase the frequency sweeping rates and to enable accurate spectroscopy measurements, the second operation 220 is carried out for modulating the laser's wavelength in time and thus temporally inducing high frequency sweeping rates of the THz radiation. For example, in addition to the continuous frequency sweeping carried out in the first operation by changing the DFB laser/s temperature, in the second operation the wavelength of one or both of the DFB laser/s is fast modulated by changing the electric current for the laser/s.
[0090] The electric current change of the DFB laser has an immediate affect on the lasers' output (as opposed to temperature changes which requires time for cooling/heating the lasers active region) and thus higher frequency modulation rate can be achieved corresponding to wavelength variation rate of up to the order of 100 nm/sec. By exploiting the high wavelength modulation rates in the lasers' output, THz sweeping with frequency sweeping rates of about β=˜15 GHz/milisec can be obtained. This is about ten times higher that the frequency modulation obtained solely by the temperature variation.
[0091] However, only a limited variation of about 0.1 nm of the wavelength of the DFB laser is obtained by the change of the electric through the laser, which is insufficient for generating and sweeping across the whole THz frequency range (zone). Thus according to the invention, the temperature variation of the laser diode (e.g. first operation 210 ) can be used to provide substantially monotonic/constant THz sweeping with typical rates of e.g. β 0 =˜3 THz/sec while current modulation is applied (e.g. second step 220 ) for providing alternating THz sweeping rates in the range of β 0 =˜+/−30 THz/sec.
[0092] It should be understood that applying a fast modulation of the laser wavelength is not limited to tuning/modulation of the electric current through the lasers and it can be performed for example applying additional fast and accurate temperature change/modulation, in addition to the sweeping applied by the temperature. Alternatively or additionally, modulation of the wavelengths of the laser beams can be performed by affecting the optical path of the laser beams for example by utilizing a non-linear optical element along the optical path. To this end, the term operational parameters of the light sources/lasers include also the optical path/medium which the light beams from those light sources traverse. Yet another option is to use a mechanical, optical or any element to frequency-modulate the output beam from the THz emitter.
[0093] Turning now to FIG. 5B , there is shown a graphic illustration G 2 of the THz frequency vs. time as generated utilizing a frequency sweeping technique according to an embodiment of the present invention. In this example the THz frequency is swept from low frequencies to high frequency (or vice versa within frequency sweeping range of about 300 GHz-3.5 THz) using a gradual temperature change while concurrently relatively fast modulation of electric current through the active regions of the lasers is applied. Similarly to the graph G 1 of FIG. 5A also here, the gradual temperature change provides monotonic frequency sweeping across the desired THz frequency range with monotonic sweeping rate β 0 of about ˜3 THz/sec. A fast modulation of the frequency with period t m of about 1 msec and with relatively low frequency shifting amplitude of about 30 GHz is obtained by applying current modulation to the laser diode(s). This results with relatively high frequency weeping rates β 1 ranging/alternating in between +/−30 THz/sec.
[0094] In this example, current modulation if applied to both laser diodes with time shift of about 0.5 msec (i.e. phase shift of about π) between the current modulations such that when relatively high current is flowing through one of the laser diodes, relatively low current flows thorough the other. This results with the output wavelengths of the laser diodes swaying in opposite directions thus increasing the resultant frequency shifting amplitudes. It should be noted however that according to the invention, each of the electric current modulation and the temperature variation can be applied to only one of the laser diodes and not necessarily to the same one.
[0095] A comparison of the THz frequency sweeping (and the rates) illustrated in FIGS. 5A and 5B yields the following results: Without frequency modulation (e.g. without modulating the current), and considering time delay τ of about 7 nanoseconds between the reference and inspecting radiations (e.g. corresponding to length difference ΔR of about 2 m between the optical paths of the reference and inspecting radiation between transmitter to the detector) the frequency of the output (homodyne) signal of the detector (e.g. the frequency difference between the reference inspecting radiation) and is about 20 KHz. With frequency modulation, e.g. when current modulation is applied, β approaches 30 GHz/msec and the frequency of the output signal of the detector reaches to about 200 KHz.
[0096] Reference is made to FIG. 6 illustrating a more specific, but not limiting example of THz spectroscopic system 100 A according to the invention. Similar referenced numbers are used in all the figures to designate common elements having essentially similar functionality or purpose.
[0097] System 100 A includes a THz transmitter (THz radiation generator) 110 and a detector 120 . The radiation generator 110 includes a THz emitter EN and an optical drive OD optically coupled together through an optical coupling OC for generating THz radiation which can be used to irradiate an inspected object O with inspecting radiation IN. The optical drive OD includes, in the present example, two light sources L 1 and L 2 (DFB lasers) associated with respective thermo-electric cooling systems TEC 1 and TEC 2 and an optical drive controller ODC connected to the light sources and to the thermo-electric cooling systems. The ODC is configured and operable for controlling the temperatures of—and the electric currents through—the light sources L 1 and L 2 and to thereby control and vary the wavelength of the lasers' output beams LB 1 and LB 2 with relatively fast rates. As noted above, this enables sweeping the THz radiation generated, at the emitter EM by photomixing of those light beams, with high frequency sweeping rates β.
[0098] To this end, the optical drive controller ODC includes a frequency/wavelength modulation controller unit FM, which in this example include one or more electric current controllers CC(s) connectable to one or more light sources L 1 and L 2 and configured and operable for modulating the current through the light sources L 1 and L 2 to affect a modulation of their output wavelengths. The optical drive controller ODC also includes a frequency sweeping controller FS which, in this case, includes one or more temperature control unit TC(s) that are configured and operable for controlling respectively the operation of the thereto-electric cooling systems TEC 1 and/or TEC 2 and to thereby affect the temperature of lasers L 1 and/or L 2 and to allow monotonic sweeping of their wavelengths and of the THz radiation obtained by their mixing.
[0099] The output light beams LB 1 and LB 2 from the lasers L 1 and L 2 are mixed together and optically coupled with at least one THz emitter EM from which the inspecting radiation and possibly also the reference radiation are generated. In many cases, it is preferable that the mixed light beams LB 1 and LB 2 are split (e.g. by optical coupler OC) into two portions OL 1 and OL 2 , preferably of substantially similar spectral content and energy such that one portion is associated with the generation of the inspecting THz radiation and the other is associated with or is serving as the reference radiation.
[0100] As illustrated in the figure, one THz emitter EM may be included in the transmitter 110 for generating the inspecting radiation from one portion OL 1 of the mixed light beams while another portion of the light beams OL 2 serves as the reference radiation and is transmitted/directed to the detector where it is mixed to generate a reference oscillator.
[0101] In general THz emitter EM may include any suitable photomixer which can be coupled with an appropriate THz antenna for generating, in the antenna, electric currents having frequencies in THz regime (being the beat frequency of the two lasers). Known in the art THz emitters utilize photoconductive semiconductors such as GA to generate THz currents or are based on the free-charge-propagation technology (e.g. vacuum based technology) as disclosed for example in WO 2007/132459 assigned to the assignee of the present invention.
[0102] Hence the THz generator/transmitter 110 generates and transmits reference radiation RR towards the detector 120 which may include (or be constituted by) a portion e.g. OL 2 of the light beams. The detector 120 includes a receiver mixer RM adapted for mixing a response radiation RS from the object O (referred to herein as being a part of the inspecting radiation IN returned from the object to the detector) with a reference radiation RR that is transmitted directly from the THz transmitter 110 . The receiver mixer RM is configured for carrying out homodyne detection of the response radiation RS and for generating detection signal HS (intermediate frequency signal) including a beat frequency of the response RS and reference RR radiations. The current modulation applied by frequency modulation controller FM to the laser diode increases the frequency sweeping rate of the transmitter 110 and thus causes the frequency difference at the detector/receiver to increase (compared to the case of no current modulation is applied).
[0103] Due to the high frequency sweeping rates β provided by the optical drive of the present invention, the detection signal obtained has relatively high intermediate frequencies allowing accurate spectroscopic measurements with relatively high signal to noise ratio over fairly broad spectral range.
[0104] Reference is made to FIGS. 7A to 7D illustrating graphically various forms of fast current modulations that can be applied to one or more of the light sources (lasers) of the systems illustrated in FIGS. 3 , 6 in order to modulate their output wavelengths.
[0105] FIG. 7A exemplifies a triangle current modulation waveform where the current I is periodically increased above certain baseline value I 0 by current modulation amplitude I m and decreased back towards the baseline value I 0 . In this example and the increase and decrease rates as well as the current modulation period t m are fixed constants.
[0106] Utilizing current modulation, as illustrated in this figure, THz frequency sweeping with rates upto 30 THz/sec can be obtained. For example, current modulation can be used for modulating the frequency of a THz radiation which baseline frequency (with respect to which the frequency modulation is applied) is monotonically swept (e.g. utilizing temperature variation) with rate of about +3 THz/sec. As a result, the frequency sweeping rate β of the THz radiation acquires periodic value which may alternate between about +30 THz/sec to −24 THz/sec. Accordingly, the alternating positive and negative high frequency sweeping rates are obtained which can be exploited by the receiver/detector for providing measurements with high signal to noise (e.g. with non-zero intermediate frequencies and therefore with low flicker noise).
[0107] FIGS. 7B and 9C show two examples of saw-tooth current modulation waveforms suited for use in the present invention. In FIG. 9B a periodic increase of the current above a baseline value I 0 with certain finite increase rate is followed by abrupt/immediate decrease of the current back to the base line level I 0 ; and vice-versa in FIG. 9C . Such saw-tooth current modulation schemes can be exploited for providing substantially constant and high frequency sweeping rate β. The sweeping rate β obtained is this case may be considered a constant value which is maintained along all the frequency sweeping range except for at “singular” time points (e.g. t s ) at which abrupt decrease/increase of the current to the laser diode is applied. Considering the durations of these “singular” time points as being negligible, they may be ignored in the detection module, thus allowing a homodyne detection to be performed as if a non-modulated and high (e.g. ˜30 THz/sec) frequency sweeping rate β is provided by the THz transmitter.
[0108] FIG. 5D 9 D illustrates an example of a sinusoidal current modulation of a laser diode with baseline I 0 amplitude I m and period t m .
[0109] It should be understood that in accordance with the present invention other modulations of wavelengths of light beams from the optical drive can be applied. For example any other form of current modulation can be used as well as modulating the wavelengths of the optical drive by varying modulating other of its operational parameters such as the temperature of the lasers or operational parameters of other optical/electro-optical means in the path of the laser's beam.
[0110] It should be also understood that the disclosed method and systems of the present invention is not limited for THz spectroscopy. The frequency modulated continuous wave FMCW sweeping technique of the invention can be implemented for high frequency sweeping of electromagnetic radiation in various frequency bands including inter-alia UV, visible, IR and microwave. The radiation swept by the FMCW technique of the invention may be that emanating from one light source/port or a radiation that is generated via photomixing of light beams from two or more light sources.
[0111] As noted above, according to some embodiments of the present invention, continuous frequency sweeping with high frequency sweeping rates can be effectively used for depth profiling (3D imaging) of a sample. In this connection, the present invention takes advantage of the frequency offset that accrues when a linear frequency scan is used. As indicated above, such frequency offset resulting from a delay in the time of arrival of the responding and reference radiation components to the receiver antenna, typically leads to the flicker noise. However, the invention utilizes this effect, rather than trying to reduce it, based on the understanding of the following.
[0112] Referring to FIG. 8A , there is shown an effect of frequency scanning onto a frequency off-set. The latter is proportional to a time delay between the reference optical signal in the receiver and the received wave. At a scale factor of 1 kHz per nsec per THz/sec, the frequency offset makes conventional lock-in detection with a band-pass filter ineffective, because the frequency offset means the signal averages to zero, or it can even fall outside the band-pass of the averaging filter. It is not practical to maintain τ=0, if delay is needed for adjusting phase or for delay profiling, so an alternative step-scan method is used as shown in FIG. 8B . This solves the problem, but at the expense of lost time as each step in the frequency profile has to be allowed time to settle. Minimising scanning time is highly advantageous in practical applications. The step-scan approach wastes valuable time because the temperature control loop which is used for frequency tuning of the laser(s) requires appreciable time to settle after a step. A typical practical step response is shown in FIG. 8C which illustrates the wasted time while temperature settles. The time wasted in settling may approach the time available for measurement.
[0113] The present invention takes advantage of the frequency offset that accrues when a linear frequency scan is used. In order to obtain practical levels of frequency sweep speed and delay, the frequency offset will naturally lie above the flicker noise of the receiver amplifier. This allows, the response at the natural offset frequency to be measured using Fast Fourier Transform processing. The Fast Fourier Transform implements a contiguous bank of band-pass filters. Depending on sweep rate and delay, the offset frequency will lie within one or a small number of filters (bandwidths). A conventional interpolation algorithm, well known in signal processing, may be used to estimate the signal amplitude over a time interval corresponding to the data collection time of the Fast Fourier Transform. This time interval defines the frequency resolution of the THz measurement in the same way as the frequency jumps in step-scan (as described above with regard to one of the known techniques), but without the settling-time loss.
[0114] It is fundamental that the frequency sweep-rate be chosen to be compatible with the desired integration time and the span of the frequency space swept in the process of the spectroscopic measurement.
[0115] For example, if 1 THz span is swept in 1 second and the required integration time is 1 msec, the FFT collection time for each resolvable measurement will be 1 msec and 1000 FFTs will be required to cover the 1 THz span at a resolution of 1 GHz. In this example, if the time delay is designed to be 10 nsec, the frequency at which data is found in the FFT is 10 kHz. The FFT sampling frequency may be chosen to support the expected frequency of the data and the FFT size adjusted accordingly. The interpolation algorithm takes care of the fact that there will not be a harmonic relationship between the FFT sampling frequency and the frequency at which the measured data appears, so the data will split over a few FFT bins. This process is illustrated in FIG. 9 .
[0116] It is recognized in this invention that the process maps delay between reference and received signals into a frequency location in the FFT. This means that delay can be measured by observing frequency location. The defining relationship is that τ=f/β, where f is the frequency observed in the FFT (i.e. beat frequency at the receiver). The resolution interval associated with this delay measurement is c/β·T), where c is the speed of light and T is the duration of the coherent processing dwell. This recognition is the key to 3D imaging or depth profiling of the sample, where the two spatial dimensions are obtained by positioning the transmitter and receiver transducers relative to the target object and the third dimension (radial distance) is obtained from the position of the signal response in the FFT filter-bank. The delay measured is a round trip delay which converts to a radial range according to the following: R=c·τ/2. It should be noted that preferably, in order to get a phase reference (position in space of a sample) calibration of the free space path prior to the measurements on the sample might be needed.
[0117] An arrangement suitable for 3D imaging is illustrated in FIG. 10 . According to the invention, parameter, β, which is the linear sweep rate, may be exaggerated, or the processing dwell, T, is chosen to achieve the desired resolution parameter in the radial dimension. For example, if (β·T)=30 GHz, the radial resolution (spatial resolution) will be 1 cm and the spectroscopic resolution is 30 GHz. The property of radial resolution is advantageous in spectroscopic measurement for the purpose of eliminating multi-path reflections. Such reflections exhibit delays different from the delay of the wanted target object and hence are gated in the FFT into filters (bandwidths) that are separated from the filter containing the desired target response.
[0118] The parameter β is controlled by temperature variation of the laser(s) or by current modulation of the laser(s). Temperature variation is relatively low speed process, while current modulation may be achieved at electronic speeds. The scale factor pertaining to temperature control on a single laser is approximately 30 GHz/deg. K for lasers near 800 nm wavelength. The scale factor relating frequency variation to laser drive current is approximately 1.6 Ghz per mA.
[0119] According to the invention, “slow” temperature variation (gradual temperature change) may be used for spectroscopic coverage while fast current modulation may be used simultaneously to achieve radial resolution. In this case, the laser(s) will be driven by a saw-tooth or triangular current waveform while the temperature may be varied simultaneously in a linear fashion. This is illustrated in FIG. 11 .
[0120] Thus, the present invention provides a simple and effective solution for high-quality spectroscopy in high-frequency applications (e.g. THz applications). The invention provides for high signal-to-noise spectroscopic measurements and also enables depth profiling or 3D imaging of the sample under inspection with high resolution in both spatial and frequency domains.
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A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position.
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This is a divisional application of U.S. Ser. No. 08/200,109, filed Feb. 22, 1994, now U.S. Pat. No. 5,487,639.
FIELD OF THE INVENTION
The present invention relates to a vortex flow blower and a vane wheel therefor. Particularly, the present invention is preferable for a vane wheel with three-dimensionally curved vane surfaces.
BACKGROUND OF THE INVENTION
Japanese Unexamined Patent Applications Shou-51-57011 and Hei-2-215997 disclose a vane wheel divided into two independent parts, with the parts being subsequently joined to each other. Japanese Unexamined Patent Application Shou-51-57011, proposes a vane wheel dividing line extending perpendicularly to a rotational axis of the vane wheel; Japanese Unexamined Patent Application Hei-2-215997, proposes an arrangement wherein the vane wheel dividing line extends along edges of vanes.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a vane wheel which is divided into at least two members for easy production, and whose rigidity, strength and vibration-absorbing-characteristic are high.
According to the present invention, a vortex flow blower for transferring gas comprises a motor having an output rotational shaft and a vane wheel driven by the shaft. The vane wheel includes vortex flow chambers opening in a direction substantially parallel to the output rotational shaft to receive the gas therein, to urge the gas in a substantially circumferential direction of the vane wheel, and to generate and accelerate a vortex flow of gas therein. A vane member includes a hub through which the vane member is connected to the shaft. A plurality of vanes extend integrally or monolithically from the hub in a substantially radial direction of the vane wheel, with each of the vanes including a front surface for urging the gas in a substantially circumferential direction of the vane wheel, and with a vortex flow chamber wall extending integrally or monolithically from both the hub in each of the vanes. A cover means contacts and/or is pressed against the vortex flow chamber wall to form a vortex flow chamber together with the vortex flow chamber wall and the vanes.
Since the vane member includes vanes extending integrally or continuously from the hub in the substantially radial direction of the vane wheel and the vortex flow chamber wall extending integrally monolithically or continuously from both of the hub and each of the vanes, the vortex flow chamber wall rigidly supports the vanes on the hub. Therefore, although the vane wheel is divided into the vane member and the cover means, the rigidity and strength of the vanes are high. Further, since the cover means contacts with the vortex flow chamber wall, a friction between the cover means and the vortex flow chamber wall, when an adhesive adheres to the cover means and the vortex flow chamber wall so that the cover means contacts with the vortex flow chamber wall through the adhesive, a deformation of the adhesive therebetween, absorbs a vibration of the vane wheel, particularly a vibration generated in the vortex flow chambers. A pressing force between the cover means and the vortex flow chamber wall is increased so as to absorb the vibration. Therefore, although the vane wheel is divided into the vane member and the cover means, the vane wheel is prevented from generating the vibration.
The vortex flow chamber wall may curve to project in the substantially radial and/or circumferential direction of the vane wheel so that a section modulus and a geometrical moment of inertia of an integral or continuous combination of the vortex flow chamber wall and the vanes are remarkably increased, and a contact area between the cover means and the vortex flow chamber wall is increased. Therefore, the rigidity, strength and vibration-absorbing-characteristic are further improved.
It is preferable for each of the vanes to be prevented from being divided. Each of the front surfaces may form an inclined angle relative to an imaginary plane substantially perpendicular to the output rotational shaft, and the angle is less than a right angle. In this case, a casting mold for forming the inclined vanes can be inserted and easily securely supported through through-holes or notches so that the vane wheel with three-dimensionally curved vane surfaces can be correctly formed. The vortex flow chamber wall may have a through-hole therein, and the cover means may cover the through-hole. The cover means may extend into the through-hole. The vane member may include a through-hole therein, and further include a radially inner vortex flow chamber wall portion and a radially outer vortex flow chamber wall portion divided by the through-hole from the vortex flow chamber wall. The vane member may include notches each extending radially inwardly from an outside of the vane member between the vanes adjacent to each other, and the cover means may cover the notches. The cover means may extend into the notches. The through-holes or notches are preferable for increasing a volume on the vortex flow chambers. When cover means extends into the notches or through-holes, an abrupt change of an inner surface of the vortex flow chambers at the notches or through-holes is prevented.
A reverse surface of the vortex flow chamber wall and, if necessary, a reverse surface of the hub may form a substantially flat surface plane, and the cover may comprise a substantially flat surface for contacting with the substantially flat surface plane to form the vortex flow chambers together with the vanes and the vortex flow chamber wall as shown in FIGS. 28-30. The cover may further comprise projections on the substantially flat surface so that the projections extend into or fill the notches or through-holes of the vane member to form a smooth inner surface shape of the vortex flow chambers.
The vortex flow chamber wall may have a portion extending in the substantially radial direction of the vane wheel and connecting the vanes adjacent to each other in the substantially circumferential direction of the vane wheel so that the rigidity and strength of the vanes adjacent to each other in the substantially circumferential direction of the vane wheel are improved. The vanes may be prevented from extending over or below the vortex flow chamber wall as seen in the direction substantially parallel to the shaft, so that the casting mold for forming the vane member can be easily and securely supported.
The cover means may have dents receiving the vanes so that the vanes are rigidly supported by the cover means in a substantially circumferential direction of the vane wheel. The vortex flow blower may further comprises a metal member joined with the vane member and with the cover means so that the cover means is connected to the vane member. The vortex flow blower may further comprises a first metal member joined with the vane member and a second metal member joined with the cover means so that the cover means is connected to the vane member, and an angle between a longitudinal axis of the first metal member and an imaginary plane substantially perpendicular to the output rotational shaft may be different from another angle between a longitudinal axis of the second metal member and the imaginary plane. The cover means may be connected to the shaft independently of the vane member. The cover means and the vane member may have respective surfaces extending substantially parallel to each other to engage with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a vortex flow blower according to the present invention.
FIG. 2 is a front view of a vane member according to the present invention.
FIG. 3 is a cross-sectional view taken along a line III--III in FIG. 2.
FIG. 4 is a partially cross-sectional schematic view of a vane member according to the present invention.
FIG. 5 is a front view of a cover according to the present invention.
FIG. 6 is a cross-sectional side view showing the cover of FIG. 5.
FIG. 7 is a cross-sectional side view showing a combination of upper and lower cast molds for forming vanes, vortex flow chambers and a hub according to the present invention.
FIG. 8 is a reverse view of a vane member according to the present invention.
FIG. 9 is a cross-sectional view similar to FIG. 3 of another cover according to the present invention.
FIG. 10 is a cross-sectional view similar to FIG. 3 of another cover according to the present invention.
FIG. 11 is a cross-sectional view similar to FIG. 3 of another cover according to the present invention.
FIG. 12 is a cross-sectional view similar to FIG. 3 of another cover according to the present invention.
FIG. 13 is a cross-sectional view of a connection between a vane member and a cover according to the present invention.
FIG. 14 is a cross-sectional view of another connection between a vane member and a cover according to the present invention.
FIG. 15 is a cross-sectional view of another connection between a vane member and a cover according to the present invention.
FIG. 16 is a cross-sectional view of another connection between a vane member and a cover according to the present invention.
FIG. 17 is a cross-sectional view of another cover according to the present invention.
FIG. 18a is a front view of another vane member according to the present invention.
FIG. 18b is a front view of another cover according to the present invention.
FIG. 18c is a cross-sectional view of the vane member of FIG. 18a.
FIG. 18d is a cross-sectional view of the another cover of FIG. 18b.
FIG. 19a is a cross-sectional view of an engagement between a vane member and a cover according to the present invention.
FIG. 19b is a cross-sectional view of another engagement between a vane member and a cover according to the present invention.
FIG. 20 is a cross-sectional view of another connection between a vane member and a cover according to the present invention.
FIG. 21a is a cross-sectional view of another connection between a vane member and a cover according to the present invention.
FIG. 21b is a partial side view of the another connection of FIG. 21a.
FIG. 22a is a front view of another vane member according to the present invention.
FIG. 22b is a front view of another cover according to the present invention.
FIG. 22c is a cross-sectional view of the another vane member of FIG. 22a.
FIG. 22d is a cross-sectional view of the another cover of FIG. 22b.
FIG. 23a is a cross-sectional view of another connection between a vane member and a cover around a driving shaft according to the present invention.
FIG. 23b is a side view of engaging projections of a vane member according to the present invention.
FIG. 23c is a side view of engaging dents of a cover according to the present invention.
FIG. 23d is a side view of an engagement between the projections and dents shown in FIGS. 23b and 23c.
FIG. 24a is a partially cross-sectional schematic view of another vane member with a curved vortex flow chamber wall extending radially inwardly and outwardly and with through-holes terminating at vanes to divide the vortex flow chamber wall into radially inner and outer portions, according to the present invention.
FIG. 24(b) is a top view of a vane member in accordance with FIG. 24(a);
FIG. 24(c) is a side view of FIG. 24(b);
FIG. 24(d) is a sectional view along section line (d)--(d) of FIG. 24(b);
FIG. 25 is a partial cross-sectional schematic view of another vane member with a curved vortex flow chamber wall extending radially inwardly and with through-holes in the vortex flow chamber wall, according to the present invention.
FIG. 26 is a partial cross-sectional schematic view of another vane member with a curved vortex flow chamber wall extending radially outwardly and with through-holes in the vortex flow chamber wall, according to the present invention.
FIG. 27 is a partial cross-sectional schematic view of another vane member with a curved vortex flow chamber wall extending radially outwardly and with notches extending inwardly from an outside of the vane member.
FIG. 28 is a partial cross-sectional schematic view of another vane member.
FIGS. 29 and 30 are front and side-cross-sectional views of cover for the another vane member of FIG. 28.
DETAILED DESCRIPTION
As shown in FIGS. 1-4 and 8, a vortex flow blower has a vane wheel 1, an electric motor 4 for driving the vane wheel 1, a casing 2 with a pressure increasing passage 3 extending substantially around a rotational shaft axis 7 of the motor 4 and the vane wheel 1 and opening in a direction parallel to the rotational shaft axis 7, an inlet 5 opening at an end of the pressure rising passage 3 to take in air, an outlet (not shown) opening at another end of the pressure increasing passage 3 to discharge the air, and a partition wall 6 arranged between the end and another end of the pressure rising passage 3.
The vane wheel 1 is mounted on an output rotational shaft 4s of the motor 4, and includes a hub 8 connected to the output rotational shaft 4s, a vortex flow chamber wall 10 for forming vortex flow chambers 9 opening to and along the annular pressure increasing passage 3 in a direction parallel to the rotational shaft axis 7 and partitioned by a plurality of vanes 12 extending substantially radially, and a cover 11 for covering through-holes or notches 50 of the vane wheel 1 at an opposite side of the casing 2. The hub 8, the vanes 12 and the vortex flow chamber wall 10 forming the claimed vane member are made integrally of a light alloy, for example, aluminum, aluminum alloy or the like through a mold process, for example, a die cast molding process.
The vanes 12 project forward in a vane wheel rotational direction to be inclined relative to an imaginary plane perpendicular to the axis 7 so that the air received by the vanes from the inlet 5 is strongly urged toward a wedge-shaped space or bottom of the vane wheel 1 formed by the vanes 12 and the wall 10 and cover 11. The air is accelerated by the vanes 12 in a circumferential direction of the vane wheel 1, and a vortex flow of the air is generated and accelerated in the vortex flow chambers 9. The vortex flow of the air proceeds in the circumferential direction of the vane wheel 1 along an annular passage formed by the pressure increasing passage 3 and the vortex flow chambers 9. Thereafter, the air pressurized, by being accelerated in the circumferential direction of the vane wheel 1 and in a spiral direction of the vortex flow, is discharged from the outlet.
The wall 10 forms the through-holes 50 at the opposite side of the casing 2, and the vanes 12 extend over or below the through-holes 50 as viewed in a direction parallel to the axis 7.
The cover 11 has an inner surface fitting onto a reverse surface of the wall 10 as shown in FIGS. 5 and 6, so that the vane wheel 1 is formed by the cover 11 and an integral or monolithic combination as the claimed vane member of the hub 8, the vanes 12 and the vortex flow chamber wall 10. The cover 11 contacts with the wall 10, preferably with a compression force therebetween. The cover 11 may be divided into a plurality of members each of which contacts with and fits onto the reverse surface of the wall 10, preferably with the compression force therebetween. The cover 11 may be made of steel, aluminum, aluminum alloy or the like, through a press or molding process.
As shown in FIG. 7, when an upper mold 200 and a lower mold 300 are combined with each other to integrally form the hub 8, the vanes 12 and the vortex flow chamber wall 10, the lower mold 300 for forming the reverse surface of the wall 10 and vanes 12 can extend into an inside of the vane wheel 1 through the through-holes or notches 50, and the combination of the upper mold 200 and lower mold 300 can be disassembled in directions indicated by the arrows a and b.
As shown in FIG. 9, the cover 11 may have projections 11a which extend into the through-holes or notches 50 respectively, and whose upper surfaces form respective parts of semicircle inner surfaces of the vortex flow chambers 9 to prevent an abrupt change of the inner surfaces of the vortex flow chambers 9 at the through-holes or notches 50, so that a smooth air flow is performed in the vortex flow chambers 9.
As shown in FIG. 10, the vortex flow chamber wall 10 may be tapered to prevent the abrupt change of the inner surfaces of the vortex flow chambers 9 at boundaries between an edge of the wall 10 and the through-holes or notches 50, so that the smooth air flow is performed in the vortex flow chambers 9. As shown in FIG. 11, the vortex flow chamber wall 10 may have projections 13 and the cover 11 may have holes 11h so that the cover 11 is pressed against and fixed to the wall 10 to form the vane wheel 1 after forward ends of the projections 13 are plastically deformed or caulked. As shown in FIG. 12, the projections 13 may be arranged on the vanes 12. As shown in FIG. 13, it is not necessary for combinations of the projections 13 and the holes 11h to be arranged at every vortex flow chambers. 9. As shown in FIG. 14, the projections 13 may be arranged on the hub 8. As shown in FIG. 15, the cover 11 may be pressed against and fixed to the integral combination of the hub 8, the vanes 12 and the vortex flow chamber wall 10 by extending through bolt apertures 15 and bolt accomodating holes 16. In this embodiment, the hub 8 is connected to the shaft 4s through a boss 8b included in the cover 11. As shown in FIG. 16, the integral combination of the hub 8, the vanes 12 and the vortex flow chamber wall 10 may be connected to the shaft 4s through the hub 8, and the cover 11 may be directly connected to the shaft 4s.
As shown in FIG. 17, the vortex flow chamber wall 10 and the cover 11 may have wedge-shaped taper projections and dents engage tightly with each other so that a hermetical seal is formed therebetween to prevent water from penetrating therebetween. It is preferable for the integral assembly of the hub 8, the vanes 12 and the vortex flow chamber wall 10 and the cover to be made of a common material to prevent a contact corrosion between different materials. If a material of the integral assembly and a material of the cover 11 are different from each other, it is preferable that an electric potential difference between the materials is small and an electrically insulating varnish of, for example, polyester type or epoxy type is arranged between the integral assembly and the cover 11. The integral or monolithic combination of the hub 8, the vanes 12 and the vortex flow chamber wall 10 may contact the cover 11 through an adhesive therebetween for fixing the cover 11 to the monolithic combination.
As shown in FIGS. 18a-18d, the vane wheel 1 may be composed of an integral or monolithic combination 109 as the vane member of a boss 109a, a hub 109b, vanes 108 and an outer limb 109c, and an integral or monolithic combination 110 as the cover means of an inner cylindrical portion 110a, a vortex flow groove wall 107 forming an annular vortex flow groove 17 and an outer cylindrical portion 110b. As shown in FIGS. 19a and 19b, the vanes 108 are fitted into the annular vortex flow groove 17 so that the annular vortex flow groove 17 is divided by the vanes 108 to form the vortex flow chambers 9. Each of the vanes 108 has at least one projection 111 fitted into at least one dent or radially extending groove 112 formed on the annular vortex flow groove 17 so that the vanes 108 is rigidly and strongly supported in the circumferential direction of the vane wheel 1 against an air pressure. The integral combinations 109 and 110 are fixedly joined with a cast portion 113 which is formed by utilizing the integral combinations 109 and 110 as a mold core.
As shown in FIGS. 21a and 21b, the integral combinations 109 and 110 are fixedly joined with casted portions 114 which are formed by inserting a melted metal into aligned grooves in the combinations 109 and 110. Preferably for strong fixing an inclined direction of angle θ of the cast portions 114 at a radially outer side of the vane wheel 1 is reverse to that of the cast portions 114 at a radially inner side thereof.
As shown in FIGS. 22a-23d, the vane wheel 1 may be composed of an integral or monolithic combination 115 as the vane member of a hub 115a mounted on the shaft 4s, the vanes 108 and an outer limb 115c, and an integral or monolithic combination 116 with the cover means of a boss 116a mounted on the shaft 4s, inner ribs 116b, the vortex flow groove wall 107 and an outer cylindrical portion 116c. The hub 115a may be fitted into the boss 116a around the shaft 4s. The outer limb 115c and the outer cylindrical portion 116c may have projections 118 and dents 119 engaged with each other by rotating the limb 115c relative to the cylindrical portion 116c as shown by an arrow R. This structure is appropriate when the monolithic combinations 115 and 116 to be fixed to each other are made of a plastic resin.
As shown in FIGS. 24-26, the vortex flow chamber wall 10, curved to extend radially and forming the through-holes or notches 50, may have a radially inner extension length different from a radially outer extension length. FIGS. 24(a)-(d) illustrate another vane member in accordance with the invention with FIG. 24(a) being a partial sectional view, FIG. 24(b) being a top view, FIG. 24(c) being a side view and FIG. 24(d) being a sectional view of FIG. 24(b) along section line d--d. The cover 11 is spaced from the flow chamber wall 10. The through-holes or notches 50 may be surrounded by the wall 10, or, alternatively, may terminate at the vanes 12. As shown in FIG. 27, the notches 50 may extend radially inwardly from an outside of the vane wheel 1 to the vortex flow chamber wall 10.
As shown in FIG. 28, the wall 10 may have an annular planar reverse surface. The annular planar reverse surface is covered by the cover 11, which includes a planar surface for contacting with the annular planar reverse surface as shown in FIGS. 29 and 30. The cover 11 may have projections 51 extending into or filling the through-holes 50 to form a smooth inner surface of the vortex flow chambers together with the vanes 12 and the vortex flow chamber wall 10.
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A vane wheel driven by a shaft for transferring a gas, comprises, vortex flow chambers opening in a direction substantially parallel to the shaft to receive the gas, to urge the gas in a substantially circumferential direction of the vane wheel, and to generate and accelerate a vortex flow of the gas. A vane member includes a hub through which the vane member is connected to the shaft, with the vane member including a plurality of vanes each extending integrally from the hub in a substantially radial direction of the vane wheel. Each of the vanes includes a front surface for urging the gas in the substantially circumferential direction of the vane wheel. A vortex flow chamber wall extends integrally from both the hub and each of the vanes, and a cover contacts with the vortex flow chamber wall to form the vortex flow chambers together with the vortex flow chamber wall and the vanes.
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This is a division of application Ser. No. 08/117,146, filed Sep. 13, 1993, which is a 371 of PCT/US92/02155, filed Mar. 18, 1992, which is a Coninuation-In-Part application of Ser. No. 07/672,537, filed Mar. 20, 1991, now abandoned.
This application relates to compounds with liquid crystalline (LC)-like properties and polymeric vehicles for coatings binders which include such LC-like compounds. More particularly, this application relates to compounds with LC-like properties wherein parts or sections of the compounds lack structural segments previously regarded as mesogenic. The structural segments of the compounds of the invention, however, provide certain properties that are similar to mesophases, but surprisingly these structures have heretofore not been identified as mesogens.
BACKGROUND
The properties of liquid crystalline (LC)-polymers differ from those of amorphous or crystalline polymers in ways that often have commercial value. Heretofore, the term "mesomorphous" has been synonymous with "liquid crystalline". LC polymers are known to form mesophases having order intermediate between crystalline polymers and amorphous polymers. See Flory, P. J., Advances in Polymer Science, Liquid Crystal Polymers I; Springer-Verlag; New York (1984) Volume 59; Schwarz, J. Mackromol, Chem. Rapid Commun. (1986) 7, 21. Further, mesophases are well known to impart strength, toughness and thermal stability to plastics and fibers as described by Kwolek et al. in Macromolecules (1977) 10, 1390; and by Dobb et al., Advances in Polymer Science, Liquid Crystal Polymers II/III (1986) 255(4), 179. Very recently it has been recognized that polymeric networks made by cross-linking LC polymers and oligomers also have greatly enhanced properties.
Because of their inherent scientific interest and of their many actual and potential commercial applications, LC polymers have been extensively studied. Many published studies have focused on identifying and classifying the kinds of chemical structures that are associated with liquid crystallinity in polymers. These studies have led to formulation of a principle, which has been generally accepted: that liquid crystallinity in polymers is invariably associated with the presence of "mesogenic groups". Mesogenic groups are chemical structures within the polymer which are capable, in certain circumstances, of imparting liquid crystallinity. Lengthy review articles cataloging and classifying mesogenic groups have been written. Most commonly, mesogenic groups are chemical structures that contain a rigid sequence of at least two aromatic rings connected in the para position by a covalent bond or by rigid or semi-rigid chemical linkages. Optionally, one of the rigid aromatic rings may be naphthalenic rings linked at the 1,5- or 2,6-positions. Of several broad classes of mesogenic groups, the most common contains two or more 1,4-arylene (or, less commonly, 1,4-trans-cyclohexenyl) rings covalently connected by rigid or semi-rigid linkages which include but are not limited to ##STR1## and various mesogens described in Ober et al., Liquid Crystal Polymers with Flexible Spacers in the Main Chain, Advances in Polymer Science 59, 104 at 105-117 which is incorporated by reference herein.
Until recently the study of LC polymers as potential coatings binders has received little attention. Chen et al., J. Coat. Technol. 1988, Vol. 60 (756), p. 39 prepared alkyd resins with mesogenic poly p-hydroxybenzoic (PHBA) acid segments (a common LC monomer) pendant to the polymer backbone. Improved dry times and film properties were observed for the alkyds. Chen et al., J. Appl. Polym. Sci. 1988, Vol. 36, p. 141 also prepared LC acrylic polymers with pendant poly PHBA groups that gave excellent lacquer and enamel properties. Wang et al., Polym. Mater. Sci. Eng. 1987, 56, 645, prepared oligoester diols which were end-capped with PHBA units. Cross-linked enamels were prepared that displayed excellent properties. Dimian et al., Polym. Mater. Sci. Eng. 1987, 56, 640, synthesized LC oligomer diols based on the mesogen 4,4'-terephthaloydioxydibenzoyl chloride. The LC diols were cross-linked to give enamels with excellent properties.
Japanese patents have claimed that PHBA enhances the properties of polyester powder coatings; Japanese Kokai 75/40, 629 (1975) to Maruyama et al.; Japanese Kokai 76/56/839 (1976) to Nakamura et al.; Japanese Kokai 76/44,130 (1976) to Nogami et al.; and Japanese Kokai 77/73,929 (1977) to Nogami et al.
In classifying "mesogenic groups" one also, overtly or by implication, classifies other groups as "non-mesogenic". Such groups are chemical structures that are outside the boundaries of the various types of mesogenic groups. They are generally considered incapable of imparting liquid crystallinity under any circumstances. Two types of non-mesogenic groups are of particular interest: (1) single 1,4-arylene units that are connected to other aromatic rings in the polymer structure by flexible rather than rigid or semi-rigid linkages and (2) 1,3-arylene rings connected in any way. Examples type of (1) and groups derived from terephthalic acid, hydroquinone and 4-hydroxybenzoic acid are: ##STR2## Examples of non-mesogenic groups of type (2) are those derived from isophthalic acid, resorcinol and 3-hydroxybenzoic acid: ##STR3##
In a recent publication [Kricheldor, Pakull and Buchner, Macromolecules, 21, 1929-1935 (1988)] it was reported that a polymer containing two electronically different aromatic non-mesogenic groups is "liquid crystalline". The structure of this polymer is: ##STR4## Krichedor et al. considered their finding very surprising. They explained the formation of liquid crystallinity by postulating a "special co-operative effect, presumably a charge-transfer interaction, between the aromatic monomer units." They stated " . . . the mesophase of 4e (the above Formula 1) is formed despite the absence of mesogenic groups. Obviously, special interaction between the bisphenol and the benzophenone imide unit is responsible for the observed smectic phases. This interaction is most likely a weak charge-transfer (CT) complexation." It was taken as a given that the isolated bisphenol unit is not a mesogenic group which may be a matter of semantics when the resulting compound exhibits LC-like properties. Indeed, semantically because the resulting compounds have LC-like properties certain linkages or parts of the compounds may be considered mesogens or mesogenic.
In another publication [Bilibin, et al. Makromol. Chem., Rapid Commun. 6, 209-213 (1985)] it was reported that chemical compounds of the structure ##STR5## " . . . exhibit monotropic mesomorphism. This can be accounted for by intermolecular hydrogen bonding as in the case of the 4-alkoxybenzoic acid melt." Also see Fornasier et al. Liquid Crystals 8, 787-796 (1990).
It is an object of this invention to provide polymeric vehicles for coatings binders which have LC-like properties.
It is another object of this invention to provide a method of imparting LC-like properties to coatings binders.
It is still another object of this invention to provide solvent dispersible polymeric vehicles for coatings binders which have LC-like properties.
It is yet another object of the invention to provide a method which provides polymeric vehicles with new thixotropic and anti-sagging properties.
Still further objects and advantages of the invention will be found by reference to the following description.
SUMMARY OF THE INVENTION
In this invention new polymeric vehicles with LC-like properties, solvent dispersible polymeric vehicles and formulated coating compositions with LC-like properties and a method for imparting liquid crystal-like properties to a coating binder and a method for providing a polymeric vehicle with thixotropic and anti-sagging properties have been discovered. The method and new polymeric vehicles of the invention provide coating binders with LC-like properties; and as a result, the method and polymeric vehicle of the invention provide coating binders and coatings with improved properties including hardness and impact resistance heretofore generally associated with known mesogenic groups and known LC polymers in the polymeric vehicle.
When applied to a substrate, some of the polymeric vehicles of the invention having LC-like properties, provide coating binders having a pencil hardness of at least about 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of about 1 mil. In one aspect of the invention, the polymeric vehicle comprises a dispersible polyester having the general Formula I shown below or dispersible adducts of the polyester having the general formula shown below:
HO--V--Al'--(W--Ar--X--Al--Y).sub.m --Ar'--Z--OH I.
wherein ##STR6## or a covalent bond; Al'═(CH 2 ) n or a covalent bond; ##STR7## or a covalent bond; ##STR8## Al═(CH 2 ) n ; ##STR9## or a covalent bond, but if ##STR10## and if V=bond, and if Al'=bond, and if W=bond and if Z=bond, then ##STR11## or a covalent bond; and ##STR12## or a covalent bond wherein m=1 to 20, but when V=bond, Al'=bond, W=bond and Z=bond, m≧2
n=2 to 20.
As used herein the term "dispersible" means that the polyester of the general formula or the adducts (amine salts or mono-oxirane addition products) of that polyester are dispersible in a medium at 25° C. which medium may also include a dispersant. The medium for the dispersion may be water, organic solvent, cross-linking agent, reactive diluent and may be or include the adducts of the polyester of general Formula I. The adducts of the polyester of Formula I also may act as a dispersant as well as serve as the medium. While the term "polyester" is used in connection with the compounds of the general formula, the compounds defined by the above general formula have molecular weights of less than about 10,000, and as a result, are oligomers.
In another aspect of the invention, the polymeric vehicle of the invention comprises adducts of the hydroxyl or carboxyl terminated polyester with the above general formula and a cross-linking agent in an amount effective for cross-linking the polyester to provide the coating binder. Many of polyesters which form part of the polymeric vehicle of the invention are not dispersible in solvents commonly used in connection with coatings. When there is a predominately aqueous media, to achieve solvent dispersibility, polymers which form a part of the polymeric vehicle of the invention are made water reducible by converting the polymers into salts (such as amine salts) by reacting a base (such as an amine) with the polyesters having acid functionality. In this aspect of the invention, a polyester having the above general formula which is a diol is converted into a diacid, tri or tetracid with a polyfunctional acid or anhydride thereof having from 4 to 20 carbon atoms. This conversion provides a carboxylated polyester or a partly carboxylated polyester where all of the hydroxy groups on the polyester have not been reacted with an acid or anhydride. In this aspect of the invention, the polyester of the general formula is reacted with at least about 10 percent and preferably 25 percent of the stoichiometric amount of acid or anhydride required to carboxylate all of the hydroxyls of the diol polyester of general formula to provide a carboxylated polyester. When the carboxylated polyester is combined with a base, such as an amine, it forms a water dispersible salt. This provides water dispersibility of the polyester and polymeric vehicle of the invention. Preferably the base has a boiling point of less than about 200° C.
In another aspect of the invention, dispersibility of the polymeric vehicle of the invention in organic solvents is effected (1) by grafting a mono-oxirane having not more than 25 carbon atoms onto the polyester of the above general formula to provide a modified polyester which is dispersible in organic solvents in a non-aqueous media or (2) by dispersing the polyester of the above general formula in a reactive diluent in combination with the organic solvent. Broadly the reactive diluent is a hydrocarbon organic liquid having from about 2 to about 5, preferably 2, functional groups such as carboxyl and hydroxyl, preferably hydroxyl. Through its functional groups, the reactive diluent is capable of reacting with the cross-linking agents described herein (preferably an aminoplast or polyisocyanate) and has a viscosity at 25° C. of from about 0.5 Pa.s to about 25 Pa.s. By way of example, the reactive diluents may be a reaction product of (1) an aromatic hydroxy acid or diacid such as terephthalic acid, para hydroxy benzoic acid or 2,6-naphthalenic acid with a mono-oxirane having not more than 25 carbon atoms such as the oxiranes described in connection with making a modified polyester by grafting a mono-oxirane thereon or (2) is the reaction product of a straight chain aliphatic diacid having 4 to 14 carbon atoms with the cyclohexyl diol 1,4-dimethylol cyclohexane which has the structure ##STR13## or is the reaction product of 1,6-cyclohexane dicarboxylic acid with a straight chain diol having 4 to 14 carbon atoms.
In the aspect of the invention which includes grafting the mono-oxirane onto the polyester to provide a modified polyester, the modified polyester is the reaction product of the mono-oxirane, the mono-oxirane being in an amount effective for making the polyester dispersible in an organic solvent. In this aspect of the invention, if the polyester of the general formula is a polyol such as diol, that diol first is reacted with a polyfunctional carboxylic acid or anhydride, having from about 4 to 20 carbon atoms as described above, to carboxylate the diol polyester (and make it a carboxylated polyester) prior to reacting the polyester with the oxirane to graft it onto the polyester. The modified polyester with the oxirane grafted thereon may be dispersed into an organic solvent medium by itself or as a part of a blend of modified polyester and polyester of the general formula. The modified polyester in the blend is in an amount effective for making the blend dispersible in an organic solvent which amount is a function of the solvent and the amount of oxirane grafted onto the polyester. In general for a polyester which has been reacted with a stoichiometric amount of oxirane, the blend of polyester and modified polyester will include at least about 70 weight percent and preferably at least about 80 weight percent modified polyester in dispersions having at least about 50 weight percent polyesters (both modified and unmodified polyester).
In the aspect of the invention which uses the reactive diluent as opposed to the modified polyester, the reactive diluent may be used to disperse carboxylic polyesters without hydroxy groups, but hydroxy polyesters are preferred. In addition to using organic solvents as the media for such dispersion, the reactive diluent may be used as a part of the media or function as a dispersant in such dispersions. Stable nonaqueous dispersions of hydroxy polyesters, such as diol polyesters of the general formula are formed at polyester to diluent ratios of from about 10:1 to about 1:4 and preferably from about 4:1 to about 1:4 at solids levels of from about 40 to about 80 weight percent. These dispersions provide a formulated coating composition which includes the polyester of the general formula, cross-linking agent, reactive diluent, and in and a preferred aspect a second dispersant additional to the reactive diluent and optionally organic solvent as an additional medium. While not intending to be bound by any theory, in the aspect of the invention which includes the reactive diluent with the polymeric vehicle in a nonaqueous media, it is believed that sometimes the reactive diluent associates with both the polyester of the general formula and solvent. This association coupled with the bulky structure of the reactive diluent results in steric stabilization. Additionally, the reactive diluent is di- or polyfunctional which functionality allows cross-linking by polyisocyanate and melamine resins during the curing of the polymeric vehicle into a coating binder.
Without using polyesters with mesogens or groups thought to be mesogenic, the invention also provides a method of imparting liquid crystalline properties to a coating binder with resulting, in certain cases, improved hardness and impact resistance associated with liquid crystalline polymeric vehicles. This method includes mixing a polyester without mesogens or groups which impart L/C properties, a modified polyester or adducts of the polyester of the general formula with a cross-linking agent to provide, in some cases, a polymeric vehicle or a formulated coating composition which will provide a resulting coating binder having a pencil hardness of at least 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of about 1 mil.
The invention provides polymeric vehicles and formulated coating compositions with "non Newtonian" viscosities and rheological properties which are well suited for polymeric vehicles for paint coatings. The invention provides compositions which have high viscosities at low shear rates, viscosities of at least about 15 Pa.s at shear rates of not greater than 1,000 sec -1 in the temperature range of from about 25° C. to about 60° C., but low viscosities at high shear rates, viscosities of not greater than 5 Pa.s at shear rates of at least about 3,000 sec -1 in the temperature range of from about 25° C. to about 60° C. Moreover, the invention provides polymeric vehicles and formulated coating compositions which have a viscosity which increases when the temperature of the polymeric vehicle is raised such as raised above about 25° C. for curing. Such properties are well suited for polymeric vehicles for coating binders for paint. Low viscosities at high shear rates provide a coating composition which can be readily applied by means which provide for high shear rates: spraying, rolling or brushing. Moreover, the invention provides for the design of polymeric vehicles and formulated coating compositions which thicken and increase in viscosity at critical bake or cure temperatures as the polymeric vehicle is heated above 25° C. This avoids oven sagging of the coating composition during curing at temperatures higher than ambient. Oven sagging is a common problem for many enamels due to a dramatic drop in viscosity at higher temperatures. The invention provides a polymeric vehicle which has a viscosity which increases with temperature in certain temperatures ranges until a maximum; as a result, the viscosity is sufficiently high at baking temperatures to minimize sagging.
Besides the latter special viscosity-vs-temperature behavior, the polymeric vehicles of the invention are thixotropic as well as shear thinning and exhibit yield stress below a certain temperature (such as T m /T c ). While thixotropic compositions are not new, the extent of "shear thinning" permitted by the invention in polymeric vehicles of the invention is novel and has not been heretofore observed in polymeric vehicles comprising oligomeric mixtures which are substantially free of polymers having molecular weights greater than about 10,000. The thixotropic and yield-stress properties of the polymeric vehicles of the invention enhance the anti-sagging properties of the formulated coatings of the invention, since they will allow lower viscosity at application conditions (such as brushing, rolling, and spraying) while remaining at a higher viscosity at baking condition (without pre-shearing or at lower shearing force). While higher viscosity during curing is good for anti-sagging, it may lead to poor levelling. Thus, an intermediate viscosity should be chosen for formulated coating compositions in order to obtain both good levelling and sagging resistance. This can be achieved by adjusting the curing temperature or the type and amount of solvent around the viscosity maximum.
The polyester of the invention is the reaction product of an aromatic compound selected from the group consisting of (I) a 1,4-disubstituted benzene which has hydroxyl or carboxylic substitution such as terephthalic acid, hydroquinone, (II) a 2,6-disubstituted naphthalene which has hydroxyl or carboxylic substitution, such as 2,6-dihydroxy- or dicarboxy naphthalene, and (III) mixtures thereof with a linear diacid or diol having 6 to 17 carbons and 4 to 15 methylene groups. The linearity of the acid or diol co-reactant provides flexible spacer groups between aromatic groups; yet, surprisingly, the polymeric vehicle of the invention has LC-like properties.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polyesters of Formula I as a part of a dispersible polymeric vehicle, including but not limited to being dispersible in an aqueous or organic solvent media, amino salt adducts thereof, oxirane adducts of the hydroxyl and carboxyl terminated polyester of Formula I and blends according to the invention may be used to make a polymeric vehicle or a formulated coating for a coating binder for improved properties such as would be expected in polymeric vehicles with known mesogenic groups. In certain aspects of the invention, some of the polymeric vehicles of the invention provide coating binders having a pencil hardness at least about 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of about 1 mil.
The polymeric vehicle of the invention includes cross-linking agents which react with the polyester of the general Formula I, amine salts thereof or oxirane adducts of carboxyl or hydroxyl terminated polyesters of Formula I to provide a coating binder which has a reverse impact resistance of at least about 60 inch-lbs. and a pencil hardness of at least about 3 H. The cross-linking agent has a functionality of two or more, that is, it contains at least two and preferably three or more reactive groups; examples are polycarboxylic acids, polyols, aminoplast resins, polyisocyanate resins such as the trimer of toluenediisocyanate, hexamethylene diisocyanate (HMDI) and a biuret thereof, isophrone diisocyanate (IPDI), isocyanates and mixtures thereof. The aminoplast resin may be a melamine resin, such as hexakis (methyloxymethyl) melamine resin (HMMM). The polyisocyanate resin may be a blocked polyisocyanate resin which is blocked with active hydrogen compounds such as alcohols, phenols, oximes or lactams.
Solvents and known additives such as pigments may be added to the polymeric vehicle to provide a formulated coating composition which is a dispersion. In the aspect of the invention which provides a polymeric vehicle for a coating binder, the coating binder gives a coating film with high hardness, flexibility, and impact resistance heretofore associated only with polymeric vehicles which include known mesogens. After the formulated coating is applied to a base or substrate, solvents (if present) evaporate leaving a solvent-free film. Evaporation and cross-linking may be accelerated by heating, as by baking. An improved film provided by the polymeric vehicle with improved hardness, flexibility and impact resistance, and the coating binder therefor, are a particularly important part of this invention. Moreover, an important aspect of this invention is that the raw materials for the polymeric vehicle are inexpensive and readily available. Since the coating binder primarily provides the desired film characteristics, the properties of the coating binder are particularly described primarily by tests which measure hardness and impact resistance.
Definitions
As used in this application, "polymer" means a polymer with repeating monomeric units as defined by the general formula and includes oligomers as defined herein. "Polyester" means a polymer which has ##STR14## linkages in the main chain of the polymer. "Oligomer" means a compound that is a polymer, but has a number average weight not greater than about 10,000 with repeating monomeric units. "Adduct of the polyester" means the following chemical addition products of the polyester of the general formula I: (1) the amine salt of acid polyester of general Formula I or of the carboxylated hydroxyl terminated polyester of general Formula I; and (2) a mono-oxirane bonded onto the polyester of the general Formula I or onto the carboxylated hydroxyl terminated polyester of general Formula I. "Cross-linking agent" means a di- or polyfunctional substance containing functional groups that are capable of forming covalent bonds with hydroxyl and carboxyl groups that are present on the polymer; aminoplast and polyisocyanate resins are members of this class; melamine resins are a sub-class of aminoplast resins. "Modified polyester" means a polyester having covalently bound modifying mono-oxirane groups as described herein and the term "grafted" or "grafting" used herein in connection with mono-oxiranes means that such oxiranes are covalently bound to the polyester; that is, the oxirane adduct is made in a process of adding the oxirane to an existing polyester. "Polymeric vehicle" means all polymeric and resinous components in the formulated coating, i.e., before film formation, including but not limited to modified polymers. The polymeric vehicle may include a cross-linking agent and reactive diluent as described herein. "Coating binder" means the polymeric part of the film of the coating after solvent has evaporated and after cross-linking. "Formulated coating" means the polymeric vehicle and solvents, pigments, catalysts and additives which may optionally be added to impart desirable application characteristics to the formulated coating and desirable properties such as opacity and color to the film.
"Solvent" means water and/or an organic solvent.
"Organic solvent" means a liquid which includes but is not limited to carbon and hydrogen which liquid has a boiling point in the range of from about 35° C. to about 300° C. at about one atmosphere pressure.
"VOC" means volatile organic compounds and "low VOC" means about 1 pound per gallon or about 120 grams of volatile organic compounds per liter of formulated coating composition, not including water. "Volatile organic compounds" are defined by the U.S. Environmental Protection Agency as any organic compound which participates in atmospheric photochemical reactions, except for specific designated compounds which have negligible photochemical activity. Water and CO 2 are not VOCs. VOCs have been generally designated to include but are not limited to myrcene, cumene, butyne, formaldehyde, carbon tetrachloride, aniline, dimethylnitrosamine, formic acid, acetone, chloroform, hexachloroethane, benzene, trichloroethane, methane, bromoethane, ethane, ethene, acetylene, chloromethane, iodomethane, dibromomethane, propane, 1-propyne, chloroethane, vinyl chloride, acetonitrile, acetaldehyde, methylene chloride, carbon disulfide, thiobismethane, bromoform, bromodichloromethane, 2-methylpropane, 1,1-dichloroethane, 1,1-dichloroethene, phosgene, chlorodifluoromethane, trichlorofluoromethane, dichlorodifluoromethane, tetrafluoromethane, tetramethylplumbane, 2,2-dimethylbutane, monomethylester-sulphuric acid, dimethylbutanone, pentachloroethane, trichloro-trifluroethane, dichlorotetrafluoroethane, hexachlorocyclopentadiene, dimethyl sulfate, tetraethylplumbane, 1,2-dibromopropane, 2-methylbutane, 2-methyl-1,3-butadiene, 1,2-dichloropropane, methyl ethyl ketone, 1,1,2-trichloro ethane, trichloroethene, 2,3-dimethylbutane, tetrachloroethane, dimethyl-3-methylene-bicyclo-heptane, A-pinene, hexachloro-butadiene, methylnaphthalene, naphthalene, quinoline, methylnaphthalene, phenyl-propanone, dimethylbenzene, O-cresol, chloro-methylbenzene, dichlorobenzene, trimethylbenzene, tetramethylbenzene, dibromo-3-chloropropane, 3-methylpentane, 3-pentanone, methylcyclopentane, (1-methylethyl)-benzene, 1-(methylethenyl)-benzene, 1-phenylethanone, nitrobenzene, methyl-methylethyl-benzene, ethylbenzene, ethenylbenzene, benzychloride, benzonitrile, benzaldehyde, propylbenzene, butylbenzene, 1,4-diethylbenzene, 2,4-dimethylphenol, dimethylbenzene, chloro-methylbenzene, dichlorobenzene, dibromoethane, 3-bromo-1-propene, butane, 1-butene, 1,3-butadiene, 2-propenal, bromochloroethane, 1,2-dichloroethane, propanenitrile, 2-propenenitrile, 2-methylpentane, 2-pentanone, 2,4-dimethylpentane, 1,3-dimethylbenzene, m-cresol, 2,4-dimethylpyridine, 2,6-dimethylpyridine, trimethylbenzene, dimethylphenol, trichloro-benzene, trimethyl-pyridine, bromobenzene, methylcyclohexane, toluene, chlorobenzene, phenol, 2-methylpyridine, pentene, 2-pentane, bromo-chloropropane, 1H-pyrrole, tetrahydrofuran, hexane, 1,4-dichlorobutane, cyclohexane, cyclohexene, pyridine, octaine, 1-octene, nonane, dodecane, propene, 2-methyl-1-pentene, 2-methyl-1-propene, isoquinoline, trichlorobenzene, propanal, butanal, 1,4-(dioxane), 1-nonene, decane, dibromochloromethane, 2-chloroburadiene, tetrachloroethene, dimethyl-methylene-bicyclo-heptane, 1,2-diethylbenzene, (1-methylpropyl)-benzene, Acetic Acid ethyl-ester, 1,3-diethylbenzene, cyclopentene, heptane, cis-dichloroethene, trans-dichloroethene, cyclopentane, cycloheptane, 1,2-propadiene, carbon oxide sulfide, 2,2,3-trimethylbutane, tetramethylbenzene, 2,4,5-trimethylphenol, 2-methyl-2-butene, tetramethylbenzene, 2,4,6-trimethylphenol, pentylbenzene, trimethyl-pentane, decamethylcyclo-pentasil-oxane, 1,3-dichlorobenzene, hexadecane, 2-methylthiophene, 3,3-dimethylpentane, 3-methyl-2-butene, 2-methyl-1-burene, 2,2,3-trimethyl-pentane, 2,3-dimethylpentane, 2,3,4-trimethylpentane, 2,6-dimethylphenol, 1,2,3-trimethylbenzene, 2,3-dimethylpyridine, 2,3-dimethylhexane, 3-chlorobenzaldehyde, 3-methylhexane, 2,4-dimethylhexane, 3-methylheptane, (Z)-2-butene, 2-methylhexane, trimethylbicyclo-heptane, (E)-2-heptene, 4-methylnonane, tetrachlorobenzene, butene, chloronitrobenzene, dichlorobenzene, dichloroethene, tetramethyl benzene, bromopropane, dichloro-1-propene, chlorobenzenamine, dimethylcyclohexane, dichloronitrobenzene, dichloronaphthalene, dimethylcyclopentane, bromoethylbenzene, dichloromethyl-benzene, benzenedicarboxaldehyde, benzoyl nitro peroxide, bromochloropropane, dibromo-chloro-propane, pentachlorobutadiene, dibromochloropropane, 2-butoxyethanol, bromopentachloro ethane, tetradecamethylcycloheptasiloxane, trimethyl-pentanediol, dodecamethylcyclo-hexasil-oxane, hexamethylcyclotri-siloxane, octamethylcyclo-tetrasil-oxane, hexadecamethylcyclo-octasil-oxane, tridecane, tetradecane.
A "high solids formulated coating composition" means a nonaqueous formulated coating containing not more than about 400 grams of volatile organic substances per liter of formulated coating composition and preferably less than about 300 grams of VOCs per liter of formulated coating composition. "Film" is formed by application of the formulated coating to a base or substrate, evaporation of solvent, if present, and cross-linking. "Air-dried formulated coating" means a formulated coating that produces a satisfactory film without heating or baking. "Baked formulated coating" means a formulated coating that provides optimum film properties upon heating or baking.
Although many of the polymers and copolymers exhibit LC-like properties, the criteria for liquid crystallinity is varying. The X-ray structure analysis can in certain instances prove liquid crystallinity, but such analysis is costly and the results are sometimes ambiguous. Less costly techniques are widely used to gain evidence for the presence of liquid crystallinity and to study it. The most common are
polarizing microscopy,
differential scanning calorimetry (DSC),
dynamic mechanical-thermal analysis (DMTA),
wide angle X-ray scattering (WAXS), and
rheological studies.
The quality of evidence of liquid crystallinity obtained from such studies may range from quite convincing to highly questionable in a given instance. Often a single technique, such as polarizing microscopy or DSC, can provide very strong, if not absolutely unchallengeable, evidence that a given polymer is liquid crystalline.
Given the above situation, applicants do not necessarily assert the polymers, polyesters and adducts thereof and polymeric vehicle of the invention are liquid crystalline. They may be, but rather, applicants assert that the polymers, polyesters and adducts thereof and polymeric vehicle of the invention exhibit liquid crystalline-like properties, or alternatively provide a polymeric vehicle with desired hardness and impact resistance. As used herein a composition or polymer exhibits liquid crystalline-like or liquid crystalline properties if at minimum a substantially homogeneous compound or polymer displays first order transitions at two different temperatures by DSC.
Hydroxyl Terminated Polyesters Of The General Formula--Nonaqueous Systems
Broadly in one aspect of the invention, the hydroxyl terminated polyester of Formula I is dispersed in a media such as a mono-oxirane adduct of the polyester of the general Formula I, an organic solvent and cross-linking agent with a dispersant such as a nonionic surfactant or lecithin to provide a formulated coating composition which provides unique coating binders with properties as previously described. The cross-linking agent is required and is in an amount effective for providing the coating binder and the media is in an amount effective for providing the dispersion for a low VOC formulated coating composition. Dispersants may or may not be required to complete or stabilize the dispersions.
In one aspect of the invention using an organic solvent as a part of a low VOC nonaqueous formulated coating composition, the polymeric vehicle of the invention comprises a cross-linking agent together with from about 20 to about 92 weight percent, based upon the weight of the weight of the polymeric vehicle, of an organic solvent dispersible oxirane adduct of a hydroxyl terminated polyester having LC properties and having the general Formula I:
HO--V--Al'--(W--Ar--X--Al--Y).sub.m --Ar'--Z--OH I.
wherein ##STR15## or a covalent bond; Al'═(CH 2 ) n or a covalent bond; ##STR16## or a covalent bond; ##STR17## or a covalent bond, but if ##STR18## and if V=bond, and if Al'=bond, and if W=bond and if Z=bond, then ##STR19## or a covalent bond; and ##STR20## or a covalent bond wherein m=1 to 20, but when V=bond, Al'=bond, W=bond and Z=bond, m≧2
n=2 to 20.
The above polyester is hydroxyl terminated where ##STR21## and Al'═(CH 2 ) n or bond and ##STR22## or bond, but if Al'=bond then ##STR23## or bond and if Ar=bond then ##STR24## or bond. The remainder of the polymeric vehicle optionally may comprise other polyesters. Cross-linking agents which may be used in such nonaqueous systems are aminoplasts, amines, regular and blocked di- and polyisocyanates and epoxies.
The hydroxyl terminated polyesters of the above general formula such as ##STR25## have low or no dispersibility in most common organic solvents, such as xylene or toluene. According to the invention, however, these hydroxyl terminated polyesters may be modified with a mono-oxirane having not more than 25 carbon atoms to provide an oxirane adduct of the polyester, which modified polyester (or adduct) is dispersible in organic solvents. The polyester modified to the oxirane adduct may be used either alone or as a blend with the polyester of the general formula along with a cross-linking agent to provide a polymeric vehicle which is dispersible such as in an organic solvent. The blend which includes the polyester, modified polyesters and cross-linking agent are particularly important in providing polymeric vehicles which are a part of a high solids formulated coating composition.
In making the oxirane adduct of hydroxyl terminated polyesters, it is preferable to first carboxylate the hydroxyl terminated polyester and then react it with the oxirane as described in other portions of this specification. This is an adduct of the polyester of general Formula I according to the invention.
In another important aspect of the invention, hydroxyl terminated or diol polyesters of the general formula can be part of non-aqueous dispersions including high solids coating dispersions by combining the diol polyester with a reactive diluent. Broadly the reactive diluent is a hydrocarbon organic liquid having from about 2 to about 5, preferably 2, functional groups such as carboxyl and hydroxyl, preferably hydroxyl. Through its functional groups, the reactive diluent is capable of reacting with the cross-linking agents described herein (preferably an aminoplast or polyisocyanate) and has a viscosity at about 25° C. of from about 0.5 Pa.s to about 25 Pa.s. The reactive diluent includes a reaction product of (1) an aromatic hydroxy acid or diacid such as terephthalic acid, para hydroxy benzoic acid or 2,6-naphthalenic acid with a mono-oxirane having not more than 25 carbon atoms such as the oxiranes described in connection with making a modified polyester by grafting a mono-oxirane thereon, or (2) the reaction product of a straight chain aliphatic diacid having 4 to 14 carbon atoms with the cyclohexyl diol 1,4-dimethylol cyclohexane which has the structure ##STR26## or the reaction product of 1,6 cyclohexane dicarboxylic acid with a straight chain diol having 4 to 14 carbon atoms. In the case of the aromatic acid, the oxirane and the aromatic acid such as terephthalic acid are reacted in stoichiometric amounts with heating and a catalyst such as triphenyl benzyl phosphonium chloride (TPBPC). While not intending to be bound by any theory, mono-oxiranes having bulkier structures such as ##STR27## as will be further described herein provide a diluent which appears to stabilize the dispersion through steric stabilization. In this connection a particularly useful diluent is the reaction product of terephthalic acid and a mono-oxirane sold under the name of Glydexx N-10 from Exxon Chemical Company. The reactive diluent also appears to be capable of association with the polyester and solvent for further stabilization. Moreover, the reactive diluent is difunctional which permits it to participate in the cross-linking reaction of the polyester and cross-linking agents such as melamines and polyisocyanates during curing. The dispersions formed with the reactive diluent and diol polyesters of the general formula are stable at solids levels of from about 40 to about 80 weight percent.
Where reactive diluent is used as a part of dispersions according to the invention, polymeric vehicles comprise the hydroxyl terminated polyester of the general formula together with amounts of reactive diluent and cross-linking resins in amounts effective for providing a coating binder having a pencil hardness of at least about 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of 1 mil. Generally, where reactive diluent is used the polymeric vehicle will have at least about 10 weight percent and preferably at least about 25 weight percent of the reactive diluent. Dispersants such as lecithin, a nonionic surfactant, or adduct of the polyester of Formula I together with organic solvents also may be added to the formulated coating composition to stabilize the system.
Hydroxyl Terminated Polyesters Of The General Formula--Aqueous Systems
In yet another aspect of the invention where the polyester is hydroxyl terminated or a diol, that polyester may be made dispersible in an aqueous solvent. To disperse the hydroxyl terminated polyester in an aqueous system, the hydroxyl terminated polyester of the general formula is carboxylated with a polyacid or anhydride, the anhydride being preferred, with a stoichiometric amount or less of the acid or its anhydride. In a particularly important part of this aspect of the invention, from about 10 to about 50 mole percent of the stoichiometric amount (the amount of acid or anhydride that would be required to have one acid or anhydride molecule react with each available hydroxyl on the polyester) of polyacid is particularly effective in providing the carboxylated polyester having an acid value in the range of at least about 30 to provide water dispersibility after the polyester is converted into an amine salt. The polyester may be carboxylated with trimellitic anhydride, phthalic, succinic and maleic anhydrides or polyacids such as adipic and isophthalic acid with trimellitic anhydride being preferred.
In this aspect of the invention, the amine salt of the carboxylated hydroxyl terminated polyester of the general formula will provide a water dispersible polymeric vehicle which comprises a cross-linking resin reactive with the amine salt of the carboxylated polyester. The amine salt comprises from about 20 to about 92 weight percent, based upon the weight of the polymeric vehicle, of the water dispersible amine salt of the carboxylated polyester. The cross-linking agent in the polymeric vehicle is an amount effective for cross-linking the carboxylated polyester to provide a coating binder having a pencil hardness of at least about 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of 1 mil. Generally, the cross-linking agent will comprise at least about 10 to about 50 weight percent of the polymeric vehicle. Cross-linking agents which may be used in the aqueous system generally are the same as those used in the aqueous system except that unblocked isocyanates can not be used in the aqueous system and blocked isocyanates can be used only with difficulty in an aqueous system.
Carboxyl Terminated Polyesters Of The General Formula--Aqueous Systems
In another aspect of the invention the carboxyl terminated polyester of the above general formula permits a water dispersible polymeric vehicle. In this aspect of the invention, the polymeric vehicle comprises a cross-linking agent together with about 20 to about 92 weight percent, based upon the weight of the polymeric vehicle, of an aqueous solvent dispersible polyester which is the amine salt adduct of the acid terminated polyester of the above general formula. This amine salt polyester has LC properties and provides a coating binder having a pencil hardness of at least about 3 H and a reverse impact resistance of at least about 60 inch-lbs. at a binder thickness of 1 mil. In this aspect of the invention, the general Formula I defines the acid terminated polyester where V and ##STR28## or where V, Ar', Al' and Z all are covalent bond then ##STR29## In this aspect of the invention, the remainder of the polymeric vehicle may optionally comprise other water dispersible polyesters or amine salts thereof. As previously stated, cross-linking agents which may be used in this aqueous system are generally the same as those used in the nonaqueous system except that unblocked isocyanates can not be used in an aqueous system and even blocked isocyanates are used only with difficulty in an aqueous system. The cross-linking agent is used in an amount effective for providing the coating binder with the hardness and impact resistance as previously described.
Carboxyl Terminated Polyesters Of The General Formula--Nonaqueous Systems
Broadly in one aspect of the invention as to the carboxyl terminated polyester of the general Formula I, these polyesters are dispersed in a media such as a mono-oxirane adduct of the polyester of the general Formula I, an organic solvent and cross-linking agent with a dispersant such as lecithin or a nonionic surfactant to provide a formulated coating composition which will give a coating binder with properties as previously described. The cross-linking agent may form part of the media and is in an amount effective for providing the coating binder, and the media is in an amount effective for providing the dispersion for a low VOC formulated coating composition. Dispersants may or may not be required to complete or stabilize the dispersions.
In an important aspect of the invention, to make the acid terminated polyester of the general formula dispersible in many nonaqueous systems, it is reacted with the mono-oxirane having not more than 25 carbon atoms with heating to form a modified polyester which is an oxirane adduct of such polyester. (If the polyester of the general formula is hydroxyl terminated, the carboxylated form thereof, e.g. is made with a polycarboxylic acid or anhydride such as trimellitic, phthalic, succinic and maleic anhydride with trimellitic anhydride. This carboxylated form is reacted with the oxirane to form such adduct.) In connection with general Formulas II and III, set forth infra, the hydroxyl terminated polyesters may be carboxylated to an acid value in the range of from about 5 to about 230. Thereafter the carboxylated polyester is reacted with the mono-oxirane. The oxirane adduct of the acid resin as previously described with nonaqueous systems including the mono-oxirane adduct of the hydroxyl terminated polyesters.
The Mono-Oxirane Adduct Aspect Of The Invention
The invention contemplates dispersions of or which include the mono-oxirane adducts of the polyester of Formula I as formulated coating compositions. The medium for the dispersion may include the mono-oxirane adduct, reactive diluent, cross-linking agent or organic solvents. The mono-oxirane reacted with a carboxyl terminated polyester or the hydroxyl terminated polyester (which is carboxylated prior to reaction with the mono-oxirane) may be propylene oxide, ethylene oxide, butylene oxide, phenylglycidyl ether, butylglycidyl ether, styrene oxide or the glycidyl esters of C-6 to C-22 mono acids. A particularly useful oxirane in the invention is a glycidyl ester of a C-10 oxo acid represented by the general formula ##STR30## where R represents a mixture of aliphatic groups, the three R groups in the oxirane having a total of 8 carbon atoms. That oxirane is commercially available from Exxon Chemical Company under the name of Glydexx N-10.
The amount of mono-oxirane grafted onto either of the carboxyl or hydroxyl terminated polyester of the general formula will vary from about 0.2 to about 2.0 or more moles of oxirane per mole of polyester, but the amount of mono-oxirane used should be effective for making the polyester of the general formula dispersible such as in non-aqueous organic solvents such as hydrocarbon solvents, aromatic solvents, esters and ketones. In general at 25° C., the modified polyester will comprise at least about 10 mole percent and preferably from about 25 to about 50 mole percent of the oxirane radical bonded onto the polyester. High mole-cular weight aliphatic oxiranes are more efficient dispersing agents in aliphatic solvents. The modified polymer may be designed with the oxirane to disperse in less expensive hydrocarbon solvents which are more likely to effect dispersion of modified polyesters with long chain oxiranes. Long chain oxiranes may adversely affect liquid crystalline or other properties which will cause the use of a shorter chain oxirane and a shift to a stronger solvent such as an aromatic or ketone. The invention contemplates the use of solvent blends and even the use of more than one oxirane to make the modified polymer.
The modified polyester which has mono-oxirane grafted thereon may be a media for a dispersion of the polyesters of general Formula I (as opposed to the adducts thereof) together with cross-linking agent. The modified polyester which has the mono-oxirane grafted thereon also may be dispersed in a nonaqueous solvent media by itself or may be mixed into a blend with an unmodified polyester of the general formula where the amount of modified polyester is effective to disperse all of the polymeric vehicle of the blend into the solvent. For a polyester of the general formula which has been reacted with a stoichiometric amount of mono-oxirane, the blend of polyester and modified polyester will include at least about 70 weight percent and preferably at least about 80 weight percent modified polyester in dispersions having at least about 50 weight percent modified and unmodified polyester.
Blending The Polyesters With Other Resins
As described above, polyesters of the general Formula I or amine or oxirane adducts of these polyesters may be dispersed with other polyesters or other coating resins such as epoxy resins, e.g. the carboxyl terminated polyester with a poly functional epoxy resin which serves as a cross-linking agent. In the blends which include poly functional epoxy resins, the oxirane adduct will comprise from about 5 to about 20 mole percent of the polymeric vehicle. In organic solvent systems, the oxirane adduct of the polyesters may be dispersed with other resins reactive with such adduct to provide a polymeric vehicle with L/C-like properties. In aqueous solvent systems, the amine salt adduct of the polyesters of the general formula may be blended with other water dispersible resins reactive with such amine salt adduct to provide a polymeric vehicle. In these circumstances, to maintain the liquid crystalline characteristics of the polymeric vehicle, if the other resins are not liquid crystalline, a minimum of about 30 weight percent, and preferably about 50 weight percent of the polymeric vehicle, based upon the weight of the polyester of the general formula or such polyester as a part of any adduct thereof, i.e. the weight in the latter instance would not include the weight of the mono-oxirane portion of the polyester. This will provide a polymeric vehicle which will result in a coating binder with a hardness and impact resistance as previously described.
Specific Important Polyesters As A Part Of The Invention
Polyesters having the general Formulas II, III, IV and V are important aspects of the invention as follows.
The oxirane adducts of Formulas II or III or Formulas II or III as part of the previously described reactive diluent are particularly important aspects of the invention. ##STR31##
The amine acid salt and the oxirane adducts of Formulas IV and V are particularly important aspects of the invention where the polyesters are carboxyl terminated. ##STR32## Making The Polyesters Of The Invention
Broadly the polyesters of this invention are 1,4-arylene monomers such as terephthalic acid and hydroquinone, or a 2,6-arylene monomers such as 2,6-dihydroxynaphthalene, which are reacted with a linear and unbranched aliphatic diacid or diol whose functionality will be reactive with the functionality of the arylene monomer. The polyesters of the invention may be made by condensation of a diacid with diol by transesterification such as transesterification of hydroquinone diacetate or 2,6-naphthalene diacetate with an aliphatic diacid. The polyesters of the invention generally are made by the transesterification of a dialkyl terephthalate with straight chain, saturated aliphatic diols; the transesterification of hydroquinone diacetate with straight chain, saturated aliphatic diacids, direct esterification with straight chain saturated aliphatic diacids, esterification of terephalyol chloride with straight chain, unbranched saturated diols, transesterification of 2,6-naphthalene diacetate with straight chain saturated unbranched diols and esterification using dicyclohexyl carbodiimide (DCC), diacid and diol as previously described. The alkyl is a lower alkyl having four or less carbons. In the latter reactions, any acid halide may be used in lieu of an acid chloride and propionate or butyrate (lower alkyls having four or less carbons) may be used in lieu of acetate. In this aspect of the invention, the polyesters may be defined as the reaction product of the a polymeric vehicle wherein the polyester is the reaction product of an arylene monomer selected from the group consisting of ##STR33## and mixtures thereof and a straight chain saturated aliphatic diol or diacid having 6 to 17 carbon atoms which diol or diacid is reactive with the arylene monomer and wherein R=alkyl having 1 to 4 carbon atoms or H, R'=alkyl having 1 to 4 carbon atoms and X=halogen.
The polyesters of the invention should generally regularly alternate between aromatic substituents and the straight chain unbranched substituents which separate or space the arylene groups. As the spacing between arylene groups increases to increase overall molecular weight, the lower number of repeating units enhances the liquid crystalline like properties of the polyesters which generally will have a number average molecular weight in the range of from about 350 to about 4,000 and preferably from about 400 to about 1800 corresponding to about m=1 to about 5 when n=6-10 in Formulas II through V. The degree of polymerization or the value of m is controlled by the relative proportions of monomers in the reaction. For example a 3:2 mole ratio of monomer approximately yields a polyester where m=2 for the excess monomer.
Conversion Of The Polyester Of The General Formula To An Amine Salt
In converting the polyester to the amine salt according to the invention, the polyester with a carboxylic acid functionality, or the hydroxyl terminated polyester which has been carboxylated as previously described, is neutralized with an amine to a pH of about 5.5 to about 11, with about 8 to about 8.5 being preferred, to create an amine neutralized polyester which is dispersible in aqueous media. In reacting the polyester with an amine, the polyester may be dispersed with a small to moderate amount of organic solvent which is miscible with water (e.g., propoxypropanol or ethanol) and neutralizing amine then being mixed with the dispersed polyester to form the amine salt of the polyester. Mixing may be by mild mixing or shearing. Alternatively, an amine, such as a liquid amine may be mixed with the polyester and water to create a dispersion of the amine salt of the polyester. Cross-linking agents used with the amine salts of the polyester in an aqueous media should be stable in water and will commonly be melamines.
The amines which can be used to make the amine salts in the invention include primary, secondary and tertiary alkyl amines and include triethyl amine, NH 3 , N-ethyl morpholine, methylamine, diethylamine, amino-alcohols, such as ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, 3-aminopropanol and their ethers, such as 3-methoxypropylamine.
Methods For Providing Anti-Sagging Shear Thinning And Thixotropic Properties
Important aspects of the invention also include a method for providing polymeric vehicles with anti-sagging thixotropic and shear thinning properties and a method of providing polymeric vehicles with these properties.
In one aspect, the invention provides a method for increasing the viscosity of a polymeric vehicle which comprises oligomers and is substantially free of polymers having a number average molecular weight greater than about 10,000. As used herein, "substantially free of polymers" means that the polymeric vehicle prior to curing does not have a number average molecular weight greater than about 2,000 or a weight average molecular weight greater than about 6,000. According to this aspect of the invention, the invention provides a method for increasing the viscosity of a polymeric vehicle when the polymeric vehicle is heated above temperatures most preferably as low as about 25 ° C. The temperature from which the polymeric vehicle is heated and yet increases in viscosity during such heating preferably may be as low as about 50° C. and may be as low as about 75° C. Generally the viscosity increase will be between the latter temperatures and about 100° C. The method for increasing the viscosity of a polymeric vehicle comprises dispersing the polyester of general Formula I or amine or oxirane adducts of such polyester with a cross-linking agent and a second oligomer to provide a dispersion at about 25° C. which provides a polymeric vehicle with antisagging properties. This addition modifies the oligomeric polymeric vehicle and provides a modified polymeric vehicle comprising an amount of the composition of the general Formula I or adducts thereof in amount effective for providing a modified polymeric vehicle which has a viscosity which will increase as it is heated from about 25° C., about 50° C. or about 75° C.
Generally to practice the method of this aspect of the invention and provide novel polymeric vehicles and formulated coating compositions that are part of this invention, the polymeric vehicle will comprise at least about 30 weight percent of the polyester composition of the general Formula I and/or adducts thereof. The novel formulated coating composition will be a dispersion which includes the polyesters of Formula I and/or the amine salts of such polyesters and/or the oxirane adducts of such polyesters. The polymeric vehicle will further comprise a cross-linker resin, and may also include other polymeric components which have a number average molecular weight not greater than about 10,000 (oligomers). In a very important aspect of the invention, the cross-linker resin and/or other oligomeric components of the polymeric vehicle together with the compound of the general formula provide a low VOC formulated coating composition. Indeed, the formulated coating composition (or polymeric vehicle) may not only be low in VOCs, but may be solventless, to wit: substantially free of organic solvent which is a VOC and/or water. As a formulated coating composition, the solventless formulated coating composition includes catalysts, pigments and other additives. In this connection substantially free of water and/or organic solvent means not more than about 5 weight percent of water or VOCs separately or combined as measured by ASTM test D-1644-59.
The cross-linker agent and the oligomeric components (in addition to the compound of the general formula or adducts thereof) are reactive with each other to provide a resulting coating binder having a pencil hardness of at least 3 H and a reverse impact resistance of at least 60 inch-lbs. at a binder thickness of about 1 mil. In this aspect of the invention the cross-linking agent includes any di or polyfunctional substance reactive with the polyester of the general Formula I or its adducts. The cross-linking agent has a number average molecular weight not greater than about 10,000 such substances including aminoplasts, amines regular and blocked, di and polyisocyanates. Oligomeric components which may be used additional to the cross-linking resin, but other than the composition of the general formula include polyesters from cyclohexyldiols such as K-Flex 188 and 128 which are available from King Industries, Norwalk, Conn., K-Flex 128 being the lower molecular weight product. All of the additional oligomeric components have a number average molecular weight of less than about 10,000.
The method of the invention includes dispersing the polyesters of Formula I and/or the adducts thereof with the cross-linking agent to provide a low VOC polymeric vehicle which is a dispersion substantially free of polymers having a number average weight of more than about 10,000. The polymeric vehicle and a formulated coating composition have a viscosity which increases as the temperature of the polymeric vehicle (or formulated coating) is increased from a selected temperature, about 25° C., about 50° C. or about 75° C. This viscosity increase avoids sagging after the polymeric vehicle is applied and heated to cure.
In another aspect the invention also provides a method for increasing the shear thinning of a low VOC polymeric vehicle which also may be a solventless polymeric vehicle (substantially free of water and/or organic solvent as previously defined). The method of increasing the shear thinning of a polymeric vehicle comprises dispersing the polymeric vehicle with the polyester of the general Formula I or adducts thereof. This method provides a high solids, low VOC modified polymeric vehicle comprising the polyesters of the general Formula I or adducts thereof in an amount effective for the increase in shear thinning of the polymeric vehicle. The method of the invention provides a modified polymeric vehicle with a viscosity of not more than about 5 Pa.s at a shear rate of at least about 3,000 sec -1 at temperatures in the range of from about 25° C. to about 100° C., preferably not greater than 1.2 Pa.s and most preferably not greater than 0.02 Pa.s. Most preferably the shear thinning will be at about 25° C., but preferably at about 50° C. or at about 75° C. To achieve the shear thinning as provided by the method, the polymeric vehicle will not require more than about 90 weight percent of the polyesters of general Formula I or adducts thereof (with the remaining amount of polymeric vehicle being about 10 weight percent cross-linking agent), but will comprise at least about 40 weight percent of these polyesters or adducts to not only provide the shear thinning as aforesaid, but also to provide a coating binder having a pencil hardness of at least 3 H and a reverse impact resistance of at least 60 inch-lbs. at a binder thickness of 1 mil. In this aspect of the invention, cross-linking resins are any di or polyfunctional substance having a number average molecular weight not greater than about 10,000 and which are reactive with the polyesters of general Formula I or adducts thereof as described above. The oligomeric components which may be in addition to the composition of the general formula include K-Flex 128 and 188.
Combining the methods of shear thinning and increasing viscosity at elevated temperatures provides a truly unique polymeric vehicle, especially in the aspects of the invention which provide a low VOC formulated coating composition or a "solventless" coating composition.
Achieving an increase in viscosity at increasing temperatures without using polymers, especially with polymers with heretofore known mesogens, provides the methods and polymeric vehicles of the invention with an importance and uniqueness heretofore not known in the art pertaining to coating binders for protective paint coatings. Moreover, in view of environmental concerns, this importance is magnified when the invention provides low VOC or "solventless" formulated coating compositions.
The polymeric vehicle according to the invention may be used with formulated coatings which are dried at ambient temperature and baked formulated coatings.
The following examples set forth exemplary methods of making oligomers, polymers and coatings according to the invention.
EXAMPLE I
Transesterification of Hydroquinone diacetate with diacids for preparation of COOH-terminated oligomers ##STR34##
Hydroquinone diacetate and a straight chain saturated aliphatic diacid (where n=6, 8 or 10) in a mole ratio of 2:3, zinc acetate dihydrate (0.0065 ppm) and antimony oxide (0.025 ppm) were placed in a three-neck flask equipped with stirrer, thermometer, condenser, and Dean-Stark trap and nitrogen gas inlet. The reactants were heated to 230° C. in a period of 1 hour and kept at this temperature with stirring for another 2 hours. The sample was then dissolved in CH 2 Cl 2 , precipitated by ethanol, filtered, washed by ethanol and dried in oven at 40° C. for 24 hours. Yield was 70-80%. NMR and FT-IR for 7g: NMR(CDCl 3 ) 1.35, v.s. (--CH 2 --), 1.75,s.bro.(--CH 2 CH 2 --COO--), 2.4, m(--CH 2 --COOH), 2.6, s. (--CH 2 OOO--C 6 H 4 --), 7.25, s. (benzene). FT-IR, 3000 cm -1 , s.bro. (--COOH), 2919 and 2851 cm -1 ,s, (--CH 2 --), 1747 and 1191 cm -1 s, (--COO--).
EXAMPLE Ia
Direct Esterification of Hydroquinone with Diacid for Preparation OH-- or COOH-- Terminated Oligomers (nHO or CnHO)
Hydroquinone and saturated aliphatic diacid in a mole ratio of 3:2 (for hydroquinone-terminated) or 2:3 (for COOH-terminated), xylene (about 8% by weight, for azeotrope with H 2 produced), and p-toluenesulfonic acid (p-TSA) (0.2% by weight) are mixed in a three-neck flask equipped with stirrer, thermometer, condenser, Dean-Stark trap, and nitrogen gas inlet. The mixture is heated to 140° C. in a period of 1 hour and kept at this temperature for another 6 hours. The temperature is then raised to 170° C. and kept there for 4 hours. The sample is recrystallized from hot toluene, washed with acetone, and vacuum stripped at 80° C. for 18 hours. Yields are about 60-85%.
EXAMPLE II
Esterification of 2,6-dihydroxy naphthalene with diacids for preparation of COOH-terminated oligomers ##STR35##
A mixture of the 2,6-dihydroxynaphthalene, straight chain saturated aliphatic diacid (where n=8 or 10) in a 2:3 mole ratio, para toluene sulfonic acid (p-TSA) (0.2% wt.) and Aromatic 150 (about 10% wt.) were heated at 230° C. for 2 hours under N 2 gas in three-neck flask equipped with stirrer, Dean-Stark trap, condenser, thermometer and N 2 inlet. Distillate was collected in the Dean-Stark trap. The reaction product was cooled down to 70°-80° C. and dissolved in CH 2 Cl 2 under heating and stirring, the hot solution was poured into ethanol, precipitating the white product. Product was filtered, washed with two portions of ethanol and dried at 40° C. overnight. Yield was 60-70%. NMR and FT-IR for 8g: NMR(CDCl3) 1.3 s.(--CH 2 --), 1.75 bro(--CH 2 CH 2 --COO--), 2.7 w (CH 2 --COOH), 2.8w (--CH 2 COO--C 6 H 4 --), 5-7 multiple (naphthalene); FT-IR 3041 cm bro.(--COOH); 2926 and 2852 cm -1 s.(--CH 2 --), 1757 and 1215 s.(--COO--), GPC: M n =1.85×10 3 , M w =3.45×10 3 for 8e; M n =1.64×10 3 , M w =3.94×10 3 for 8g.
EXAMPLE III
Esterification of 2,6-dihydroxynaphthalene with diacid using dicyclohexylcarbodiimide (DCC) ##STR36##
A solution of 2,6-dihydroxynaphthalene (0.05 mole), aliphatic diacid (where n=8 and 10) (0.075 mol), dicyclohexyl carbodiimide (DCC) (0.0733 mole), para toluene sulfonic acid (p-TSA) (0.004 mole) and pyridine (150 mL) were stirred at room temperature. After stirring 24 hrs. a white solid was filtered to remove dicyclohexane urea (DCU). The solution was concentrated on a rotary evaporator, the residue was dissolved in CHCl 3 and washed with two portions of 10% HCl aq. followed by water until the water was neutral. The solution was dried over anhydrous MgSO 4 and filtered. The residue was separated from CHCl 3 with ethanol, followed by filteration. Residue was dried in an oven at 40° C. overnight. Yield was 50-75%. NMR and FT-IR indicate that the products formed by the DCC have similar structure as by other methods. As for 10e and 10g, the mole ratio is 3:2 of hydroxynaphthalene and diacid.
A. Preparation of water reducible dispersion for 7c, 7e, 7g and 8e, 8g of Examples I and II
After the above reactions were completed, the products were cooled to 160° C. under stirring. Butyl cellosolve and dimethylethanolamine (DMEA) were added to reduce the temperature to 110°-130° C. The pH was adjusted to about 8 and the latter temperature range was maintained for 30 min. Water was added to yield a water reducible dispersion, which was used without purification. Non-volatile weight (NVW) is determined after 2 hours of drying at 120° C. (the solid content is about 50%, the solvent contains 80% water).
B. Enamel preparation
The water reducible dispersion of the above samples, HMMM (Resimene 731) and p-TSA in a 70/30/0.3 wt. ratio were cast on steel panels and were baked at 175° C. for 20 min. The film thicknesses were an average of 0.004 in. (4 mil).
C. Results and discussion
DSC:DSC thermograms for 7c, 7e, 7g and 8e, 8g, 10e, 10g generally showed two or more transitions on heating and cooling, however, 9e and 9g exhibit single peak on heating. The transition temperature of these samples are listed in Table 1. However, the same polymers synthesized by different methods (such as DCC, direct transesterification) had different transition temperatures in DSC. Differences are possibly due to different molecular weight, as an increase of the oligomer molecular weight increases phase transition temperatures.
WAXS:Diagrams exhibit three peaks obtained from sample quenched from 5° C. above T m . For example, the d-spacing of 16.3 Å in 8e indicates a layered structure; the d-spacing at 4.08 and 4.35 Å in 8e are attributable to lateral distances between rigid molecules in the layers. These data are listed in Table 2.
Experimental results indicate that these polymers appear to have liquid crystalline properties. Soft methylene spacers have been found to enhance liquid crystallinity in many cases. Because flexible linking groups can exist in multiple conformations, they tend to enable formation of liquid crystals under suitable circumstances.
D. Physical properties
The coatings of water reducible dispersion made from the above polymers have good mechanical properties, as listed in Table 3.
TABLE 1______________________________________Thermal properties of oligomers for 7c,7e, 7g, 8e, 8g, and 9c, 9g, 10e, 10g. Heating CoolingNo. n T.sub.1 T.sub.2 T.sub.3 T.sub.1 T.sub.2______________________________________7c 6 202.3 220.4 232.8 194.7 220.47e 8 133.5 158.6 148.3 119.27g 10 131.8 148.4 137.3 119.98e 8 138.4 145.3 157.1 153.4 125.98g 10 130.7 145.6 138.2 122.69e 8 133.8 138.9 124.19g 10 113.9 112.7 102.810e 8 115.0 128.0 143.5 143.1 104.110g 10 113.9 155.1 164.9 158.4 146.4______________________________________
TABLE 2______________________________________The peaks of WAXS for 7c, 7e, 7g and 8e, 8g.No. n d-spacings (A)______________________________________7c 6 10.85 4.98 4.147e 8 14.14 4.28 4.027g 10 17.03 4.40 4:098e 8 16.25 4.35 4.088g 10 17.24 4.29 4.03______________________________________
TABLE 3______________________________________The mechanical properties of films made fromthe water reducible dispersion of7c, 7e, 7g and 8e, 8g. Impact resistanceTukon hardness (Lb-In)No. (KHN) Direct Reverse______________________________________7c 22 160 607e 28 160 1207g 27 160 608e 27 160 1608g 18 160 160______________________________________
EXAMPLE IV
Diol/Terephthalic Acid Polyesters
Carboxylyic acid functional polyesters were prepared from terephthalic acid (TPA) and linear aliphatic diols as shown below: ##STR37## wherein n=2, 6 and 10 for the diol.
The properties of polyesters (A):
Appearance: milky white solids.
Differential Scanning Calorimetry (DSC): Two transitions for n=6, 10 (113.0° and 121.8° C. for n=6; 89.7 and 105.3° C. for n=10); capillary observation indicates solid-liquid transition at the lower transition temperature.
No transition was observed for n=2 up to 350° C. (decompose).
X-ray diffraction: Samples quenched from 5° C. above T m show several strong peaks at wide angle region, indicating crystallinity at temperatures above T m .
Solubility: Insoluble in ketones, alcohols, esters, etc.; slightly soluble in chloroform.
EXAMPLE IVa
Modify the polyester A with an epoxy known as Glydexx N-10 available from the Exxon Chemical Company ##STR38## where R in Glydexx represents aliphatic groups, the three R groups having a total carbon number of 8; TPBPC is triphenyl benzyl phosphonium chloride.
Properties of (IVB):
Appearance: All grafted polyesters (n=2, 6, 10) are milky white to light yellow non-transparent viscous liquids.
X-ray diffraction: Several sharp peaks in the wide angle region, indicating crystallinity of these liquid samples.
DSC: two first order transitions at 23.5° and 60.9° C. for n=10; two first order transitions at 40.6° and 90.1° C. for n=6; no well-defined transitions were observed for n=2.
Dispersibility: All form stable high solids (60-80%) dispersions in several solvents at room temperature.
n=10: 80% solids dispersion in methylisobutylketone and butyl acetate; 70% solids in xylene and 2-heptanone.
n=6: 60% solids dispersion in methylisobutylketone, 2-heptanone, butyl acetate, and xylene; clears to transparent solution when heated to elevated temperatures below 100° C.
n=2: 80% solids dispersion in 2-heptanone and butyl acetate; becomes two phases when diluted to 60% solids (a clear top phase and a concentrated dispersion).
EXAMPLE IVb
Cross-linking polyester IVB with hexakis (methoxymethyl) melamine resin (HMMM)
Formulation:
______________________________________Formulation:______________________________________Polyester (IVB) 1.4 gHMMM Commercially available 0.6 gas Resimene 746Para-toluenesulfuric acid 0.004 g (0.2%)(p-TSA)xylene 1.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties: n = 10 n = 6 n = 2______________________________________Pencil hardness 4H/5H 6H/7H 7H/8HTukon hardness (KHN) 9 18 30Reverse impact resist- 80 >160 >160ance (inch-pounds)Direct impact resist- >160 >160 >160ance (inch-pounds)Appearance glossy, glossy, some no pin- fuzzy- defects holing looking______________________________________
Film thickness about 1 mil; same thickness for other films.
X-ray: For n=6, some weak peaks in the wide angle region, indicating some crystal domains; for n=2, several sharp peaks in the wide angle region, indicating high crystallinity.
EXAMPLE IVc
Cross-linking Polyester IVB with a toluene-diisocyanate prepolymer (Mondur CB-60)
Formulation (as for n=10):
______________________________________Formulation (as for n = 10):______________________________________Polyester (IVB) 1.27 g (0.0020 equivalents)Mondur CB-60* 0.89 g (0.0022 equivalentsdibutyltine 0.0043 g (0.2% w/w)dilauratexylene 1.0______________________________________ *Mondur CB60 is an adduct of toluene diisocyanate and a triol.
Baking condition: 70° C. for 30 minutes.
______________________________________Film properties: n = 10 n = 6 n = 2______________________________________Pencil hardness HB/H 3H/4H 6H/7HTukon hardness (KHN) 10 18 30Reverse impact resist- 80 >160 >160ance (inch-pounds)Direct impact resist- >160 >160 >160ance (inch-pounds)Appearance glossy, glossy, some no pin- fuzzy- defects holing looking______________________________________
X-ray: For n=6, some weak peaks in the wide angle region, indicating some crystal domains; for n=2, several very strong sharp peaks in the wide angle region, indicating high crystallinity.
EXAMPLE V
Terephthalic acid (TPA)/diol/Polyesters
Hydroxy functional polyesters were prepared from TPA and diols by the methods shown below. ##STR39## wherein n=6, 7, 8, 9, 10, 12 or 16 where DCC represents dicyclohexylcarbodiimide and DCU represents dicyclohexylurea.
Properties of Polyesters (VC):
DSC: Two or three first order transitions on heating and one or more transitions on cooling, typical of LC polymers.
Cross-polarizing microscope: The samples quenched from 5° C. above T m shows batonnet or grain-like textures, indicating possible smectic C or nematic structure.
X-ray: Several peaks in the wide angle region and a medium peak in the small angle region, indicating possible smectic C structure.
Solubility: Soluble in chloroform and dichloromethane; insoluble in ketones, alcohols, esters, etc.
Esterification Using DCC for Preparation of Polyesters of the Type nGT, nHQ, CnHQ, and CnGT where nGT means --OH terminated polyester, CnGT means --COOH Terminated Polyester, nHQ means --OH Terminated Polyester made with Hydroquinone and CnHQ means a --COOH Polyester made with Hydroquinone
Terephthalic acid (or saturated aliphatic diacid) (0.02 or 0.03 mol), saturated aliphatic diol (or hydroquinone) (0.02 of 0.03 mol), p-TSA (0.0024 mol), and DCC (0.044) is dissolved in 200 ml of pyridine in a single-neck flask with DCC being added last. A white precipitate begins to appear in about 2-10 min., which is dicyclohexylurea (DCU). After stirring at room temperature or elevated temperature (up to 80° C.) for 24 to 6 hours, the reaction solution is filtered to remove DCU, concentrated on a rotary evaporator, and dissolved in CH 2 Cl 2 to remove the remaining DCU. The CH 2 Cl 2 solution is washed with 3 portions of 10% HCl and 3 portions of water, dried over MgSO 4 , and concentrated to a high concentration (polyester not precipitated yet). The polyester is precipitated by adding acetone. The sample is dried over vacuum at 60° C. for 8 hours. Yields are about 50-90%.
EXAMPLE Va
Modify Polyester VC with succinic anhydride and then with Glydexx N-10 ##STR40##
Properties of the Glydexx N-10 grafted polyester (n=10):
Appearance: Milky white to light yellow non-transparent viscous liquid, indicating crystallinity or liquid crystallinity in the liquid sample.
DSC: For n=10, two transitions (28.7 and 69.8° C.) are observed, typical of LC polymers.
Polarizing microscope of quenched sample: grain- and batonnet-like textures, indicating possible nematic or smectic C structures.
X-ray: Several strong peaks in the wide angle region and a medium peak at small angles (6.24°, 14.14 Å), suggesting possible smectic C or cybotactic nematic (nematic with short-range smectic-like ordering) structure.
Solubility: Form stable dispersion in toluene and MIBK (methyl isobutyl ketone) with 60-80% solids.
EXAMPLE Vb
Cross-linking of non-grafted polyester (VC) wherein n=10 with HMMM
______________________________________Formulation:______________________________________Polyester (VC) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 3.0 g (soluble only at elevated temp.)______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 6H/7HTukon hardness 20 KHNReverse impact resistance >160 inch-lbs.Direct impact resistance >160 inch-lbs.Appearance fuzzy-looking______________________________________
EXAMPLE Vc
Cross-linking of Glydexx N-10 grafted polyester (VD) with HMMM (Resimene 746)
______________________________________Formulation:______________________________________Polyester (VD) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 1.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 3H/4HTukon hardness 20 KHNReverse impact resistance 60 inch-lbs.Direct impact resistance >160 inch-lbs.Appearance glossy - no defects______________________________________
EXAMPLE VI
Terephthalic acid/diol/Phthalic Anhydride/Glydexx N-10 modified oligomer
Polyester (VC) (containing a repeating unit of 2 as the cases before) was grafted or reacted with phthalic anhydride (PA) and then with Glydexx N-10. ##STR41## wherein n=6, 10 and 12.
The properties of the Glydexx N-10 grafted oligoester (with n=10):
Appearance: Milky white to light yellow non-transparent viscous liquid.
X-ray: Several peaks in the wide angle region and a weak peak in small angles (6.06 Å, 14.6 Å).
Solubility: Form stable dispersion in toluene with 60% solids.
EXAMPLE VIa
Cross-linking oligomer VIE with HMMM (Resimene 746)
______________________________________Formulation:______________________________________Oligoester (IVE) 1.4 gHMMM (Resimene 746 0.6 gp-TSA 0.004 gtoluene 2.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 3H/4HTukon hardness 12 KHNReverse impact resistance >80 inch-lbs.Direct impact resistance >160 inch-lbs.Appearance glossy - no defects______________________________________
EXAMPLE VIIa
Terephthalic Acid/diol/Trimellitic Anhydride Oligoesters
The oligoester (VC) (containing 2 repeating units) was grafted or reacted with trimellitic anhydride (TMA) and then was grafted or reacted with Glydexx N-10 as shown below. ##STR42## wherein n=6, 10 and 12.
The properties of the Glydexx N-10 grafted oligoester (with n=10):
Appearance: Light yellow transparent semisolid.
X-ray: Several peaks in the wide angle region and a weak peak in the small angle region (6.6°, 14.6 Å) indicating LC structure of the material.
Solubility: Form dispersions in toluene with 60-80% solids.
EXAMPLE VIIb
Cross-link oligomer VIIF with HMMM (Resimene 746)
______________________________________Formulation (n = 10):______________________________________Oligoester (VIIF) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 1.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 6H/7HTukon hardness 15 KHNReverse impact resistance >80 inch-lbs.Direct impact resistance >160 inch-lbs.Appearance glossy - no defects______________________________________
EXAMPLE VIIc
Cross-link oligoester (VIIF) with a toluenediisocyanate prepolymer
______________________________________Formulation (n = 10):______________________________________Oligoester (VIIF) 1.02 g (0.0030 equivalents)Mondur CB-60 1.33 g (0.0033 equivalents)dibutyltin 0.005 g (0.2% w/w)dilauratetoluene 1.0 g______________________________________
Baking condition: 70° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 6H/7HTukon hardness 22 KHNReverse impact resistance >160 inch-lbs.Direct impact resistance >160 inch-lbs.Appearance glossy, no defects______________________________________
EXAMPLE VIII
Terephthalic acid/diol/epoxy modified polyesters
Glydexx N-10 was directly grafted onto Oligoester (C) as shown below. ##STR43##
Properties:
Appearance: Light yellow, turbid, viscous liquid (for n=10, 6), typical of LC polymers.
DSC: For n=10, three transitions: 10.3, 47.0 and 64.0° C.
Cross-polarizing microscope: Grain-like structure.
Solubility: For n=10, 30% clear solution in toluene; 70% stable dispersion in toluene.
EXAMPLE VIIIa
Polyester VIIIG cross-linked with HMMM (Resimene 746)
______________________________________Formulation:______________________________________Polyester (VIIIG) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 1.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties: polyester (VIIIG) n = 6 n = 10______________________________________Pencil hardness 6H/7H 6H/7HTukon hardness (KHN) 25 20Reverse impact resistance 80 160(inch-pounds)Direct impact resistance >160 >160(inch-poundsAppearance glossy, glossy, no defects no defects______________________________________
Film thickness about 1 mil; same thickness for other films.
X-ray of Resimene 746 cross-linked film (n=10): a broad refraction peak in the wide angle region and a weak but sharp peak in small angles (4.93°, 17.9 A), indicating that the film is generally in an amorphous state but also contains some liquid crystal domains.
EXAMPLE IX
Hydroquinone/Diacid/Polyesters
Carboxylic acid functional polyester from hydroquinone (HQ) and linear aliphatic diacids were prepared as shown below. ##STR44## wherein n=10.
Properties of the polyester with n=10:
Appearance: Light brown solid.
DSC: Three first order transitions on heating (100.4, 115.0, and 129.8° C.) and three on cooling (93.4, 105.1, and 124.1° C.), indicating liquid crystal behavior.
X-ray: Two sharp peaks in the wide angle region and one sharp peak in small angles, indicating smectic structure.
EXAMPLE IXa
Polymer IXH was grafted with Glydexx N-10 as shown below ##STR45##
The material with n=10 is a yellow brown viscous liquid.
EXAMPLE IXb
Polymer IXI was cross-linked with HMMM {Resimene 746)
______________________________________Formulation (n = 10):______________________________________Polyester (IXI) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 2.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 3H/4HTukon hardness 13 KHNReverse impact resistance 80 inch-lbs.Direct impact resistance 160 inch-lbs.______________________________________
EXAMPLE X
Diacid/Hydroquinone/Epoxy Modified Polymers
Hydroxy functional polyesters were prepared from hydroquinone (HQ) and linear saturated aliphatic diacids as shown below. ##STR46## wherein n=4, 6 and 10.
Properties of the polyester with n=10:
Appearance: Light brown solids.
DSC: Three first order transitions on heating (85.0, 104.7, and 120.8° C.) and three on cooling (61.7, 85.6, and 103.8° C.), indicating multimesomorphous liquid crystal behavior.
Crossed polarizing microscope: Brush- and grain-like (quenched from 80° C.) and schlieren (quenched from 100° C.) textures, indicating possible smectic C and B structures.
X-ray: Three strong sharp peaks in the wide angle region and two medium sharp peaks in small angels, indicating smectic structures.
EXAMPLE Xa
Polyester X was grafted with Glydexx N-10 as shown below ##STR47##
The material with n=10 is a yellow brown viscous liquid.
EXAMPLE Xb
Polyester XK was cross-linked with HMMM (Resimene 746)
______________________________________Formulation (n = 10):______________________________________Polyester (XK) 1.4 gHMMM (Resimene 746) 0.6 gp-TSA 0.004 gtoluene 2.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
______________________________________Film properties:______________________________________Pencil hardness 3H/4HTukon hardness 13 KHNReverse impact resistance 80 inch-lbs.Direct impact resistance 160 inch-lbs.______________________________________
EXAMPLE XI
Synthesis of ##STR48##
A mixture of HOOC--(CH 2 ) 10 --COOH, p-hydroxybenzoic acid (PHBA), methansulfonic acid (MSA) and Aromatic 150 (a mixed alkyl benzene solvent commercially available from Exxon Chemical Company) are heated under N 2 in a 3-neck flask equipped with stirrer, Dean-Stark trap, condenser and thermometer. The PHBA/diacid mole ratio is 1/2 and 0.1 wt. % of methanesulfonic acid is used. The amount of Aromatic 150 is adjusted to maintain the temperature at 220°-230° C.; about 10 wt. % is needed. Distillate (cloudy H 2 ), usually 95-99% of theoretical amount, is collected in the Dean-Stark trap during 5-7 hr. The reaction mass are cooled to 115° C., and methylisobutylketone (MIBK) are added for easy handling. The reaction mass are directly poured out from flask into a sample can at about 200° C.
The crude product is dried in oven at 120° C. and cooled and ground. The product is washed 3-4 times with methanol and centrifuged if necessary. Then oven drying and grounding is applied repeatedly. The purified product is dried overnight in oven at 110° C. The yield varies, but is about 10% or higher.
EXAMPLE XII
Synthesis of poly hexanediol terephthalate ##STR49##
Two moles acid chloride of terephthalic acid ##STR50## and three moles of 1,6-hexanediol [HO (CH 2 ) 6 OH] are placed in a 100 mL flask equipped with a distillation extender, a septum, and a stirring magnet. The flask is flushed with argon for 15 min. then heated in an oil bath at about 150° C. The HCl in the argon flow can be monitored by pH paper--a more quantitative method uses a basic solution of known normality and allows the argon flow to bubble through. The solution is then titrated and the extent of reaction can be calculated. The reaction time is about 4 to 8 hours.
EXAMPLE XIII
Non-Aqueous Dispersion Of Modified Polyester And Blends Of Polyester Of General Formula And Modified Polyester
XIII(a)--Polyester Having LC-Like Properties
The diol polyester having the formula ##STR51## was made as follows.
59.1 g (0.50 mol) 1,6-hexanediol, 58.3 g (0.30 mol) dimethyl terephthalate ##STR52## and 0.235 g (0.2% w/w) zinc acetate dihydrate (ZnAc.2H 2 O) were charged to a 250-mL flask equipped with thermometer, stirrer, nitrogen gas inlet, and Dean-Stark trap. The mixture was heated to 200°-220° C. in about one hour and kept at this temperature range with stirring until no more condensed liquid came out (in about 1 to 2 hours). The material was dissolved in hot acetone, recrystallized, filtered, and dried at 70° C. in an oven for 5 hours. 75 g white solid was collected (yield: 76.0%); NMR indicates the expected molecular structure and a repeating unit of x=2.0. As a by-product, 15 g lower molecular weight (n<2.0) polyester was collected after evaporating the filtered acetone.
EXAMPLE XIII(b)
Modified Polyester Having LC-Like Properties
The polyester (XIIIa) was modified with the mono-oxirane Glydexx N-10 by carboxylating the polyester and reacting the carboxylated polyester with the oxirane as follows. ##STR53##
61.5 g (0.1 mol) XIIIa and 38.4 g (0.2 mol) trimellitic anhydride were charged into a 250-mL flask equipped with stirrer, thermometer, water condenser, and nitrogen gas inlet. The mixture was heated to 180° C. in one hour and kept at this temperature for another hour. 100.0 g (0.40 mol) Glydexx N-10 and 0.20 g triphenyl benzyl phosphonium chloride (TPBPC, 0.20 g/mol epoxide) were added. The mixture was heated at 150°-180° C. for 90 minutes. The sample was diluted with 150 g toluene, poured into a 800-mL beaker, and washed with 3 portions of 400 mL petroleum ether with the supernatant liquid being recanted each time. The washed sample was then dissolved in 300 mL toluene and the precipitate (if any) was filtered out. The solution was concentrated on a rotavap and then heated to 150° C. to remove all the solvents. The final product (XIIIb) was light-yellow transparent liquid at higher temperatures and non-transparent semi-solid at room temperature. Yield was 162.0 g (81%). The expected structure, as shown above, was verified by NMR spectroscopy.
EXAMPLE XIII(c)
Comparative Polyester Without LC-Like Properties
A diol polyester without LC-like properties was made as shown below. That polyester was carboxylated and then modified with the oxirane Glydexx N-10 as shown below to provide the oxirane modified polyester XIIIc.
Synthesis of oxirane modified XIIIc ##STR54##
29.62 g (0.20 mol) phthalic anhydride and 35.45 g (0.30 mol) 1,6-hexanediol were charged into a 250 mL flask equipped with nitrogen gas inlet, thermometer, Dean-Stark trap, and condenser. The mixture was heated to 150° C. in 30 minutes and kept at 150° C. for another 30 minutes. 0.13 g ZnAc.H 2 O (0.20% w/w of monomers) was added and the temperature was raised to 200°-230° C. and kept at this temperature range until no more condensed liquid came out (in about 1 hours; 2.8 g water was collected). 38.4 g (0.2 mol) trimellitic anhydride was added and the mixture was heated at 150°-180° C. for 1 hour. 100.0 g (0.40 mol) Glydexx N-10 and 0.20 g TPBPC (0.20 g/mol epoxide) were added and the mixture was heated at 150°-180° C. for an additional hour. The sample was diluted with 150 g toluene and poured into a 800 mL beaker, and washed with 3 portions of 400 mL petroleum ether with the supernatant liquid being decanted each time. The washed sample was dissolved in 300 mL toluene and the precipitate (if any) was filtered out. The solution was concentrated on a rotavap and then heated to 150° C. to remove all the solvents. The final product was light-yellow transparent liquid at room temperature. Yield was 182.0 g (91%). The expected structure of XIIIc was identified by NMR spectrum.
PROPERTIES OF DISPERSIONS OF POLYMERS XIIIa, b & c
Dispersion or Solution Preparation
(A) Formation of Dispersions of XIIIa and XIIIb ##STR55##
1.9 g of the modified polyester XIIIb and 0.10 g of the polyester XIIIa were charged into a glass vial (uncovered) and heated on a Bunsen burner until the polyester XIIIa completely melted. 1.33 g xylene was added slowly, forming a homogeneous solution. The solution was cooled at room temperature with good shaking (or with ultrasonication), until dispersion formed.
(B) XIIIb Only ##STR56##
2.0 g of the polyester XIIIb and 1.33 g xylene were charged into a glass vial and heated on a steam bath until the polyester XIIIb was completely dissolved. The solution was well shaken while cooling at room temperature. A dispersion was gradually formed during cooling, while some of the polyester XIIIa precipitated on the bottom. However, the solution became a homogeneous turbid solution (or dispersion) after 24 hours.
Instrumental Methods Used In Testing Described In Example XIII
1 H-NMR spectra were measured at 34° C. at a Varian Associates EM 390 NMR spectrometer with tetramethyl silicone (TMS) as internal standard.
Viscosity was measured by an ICI cone and plate viscometer. The sample was measured 1 day after preparation. The shear rate was about 10,000 s -1 . For shear thinning sample, the steady state viscosity was recorded.
Differential scanning calorimetry (DSC) was carried out using a Du Pont 990 thermal analyzer at a heating rate of 10° C./minute and a cooling rate of 2° C./minute. The lower cooling rate and higher heating rate were limited by the instrument. Since a specific cooling system was not available, cooling was accomplished by the atmosphere. The heating from very low temperature (precooled by dry ice) could not be too slow. The samples were prepared by drying the dispersions at 100° C. for 30 minutes and cooling to room temperature by sitting in the atmosphere. During DSC experiments, samples were contained in sealed aluminum pans and an identical empty pan was used as a reference.
Liquid crystal textures and particle distribution of the dispersions were examined at room temperature by an Olympus model BH-2 microscope equipped with crossed polarizers. The liquid samples (as dispersions) were directly examined for particle distribution without evaporation.
Film Casting/Baking And Testing For Example XIII
The coatings were cast film on 1000 Bonderite polished steel panels with a drawdown bar. The coatings were baked at 150° C. for 20 minutes.
After baking the films were tested I day after cross-linking. Reverse impact resistance, Knoop hardness (KHN), acetone resistance, and crosshatch adhesion were measured according to ASTM D2794, D1474, D2792, and D3359 respectively.
Stability Of The Dispersions Of Example XIII
When hot solutions of mixed polyester XIIIb and polyester XIIIa in xylene were cooled down to room temperature with good shaking, turbid dispersions were formed; no precipitates other than dispersed particles were observed. Most of the dispersions prepared were stable for at least 1 day. After several days, some dispersions were still stable, but some separated into two layers (phase separation), the one on the top with lower concentration and the other on the bottom with higher concentration. However, after good shaking or stirring, the phase-separated samples became homogeneous dispersions again. Table 4 in this Example shows the stability of the dispersions after one week of preparation. With the increase in the insoluble polyester XIIIa content, the dispersion became less stable, possibly because less amount of soluble polyester will be available to stabilize the insoluble polyesters, causing poorer stability. Stability also increased with the polymer concentration (or percent solids), possibly because of the higher viscosity of the liquid phase at higher polyester concentration.
TABLE 4__________________________________________________________________________Stability of blend of XIIIa and XIIIb in xylenedispersions after 1 week.__________________________________________________________________________XIIIa in polymer 2.5% 5% 7.5% 10% 12.5% 15% 20% 30% 40% 50%blend50% polymer SD SD PS PS PS PS PS PS PS PSblend-indispersion60% polymer SD SD SD PS PS PS PS SS SS SSblend-indispersion70% polymer SD SD SD SD SD SD SD SS SS SSblend-indispersion__________________________________________________________________________ where SD = stable dispersion; PS = phase separation; SS = semisolids.
The mechanisms for the stabilization of the dispersions are not clear. However, dispersion stabilization is possibly due to the steric effect caused by the bulky alkyl groups on polyester XIIIb. Some polyester XIIIb molecules will co-crystallize with polyester XIIIa during the dispersion formation (as will be discussed later). Many of them will be on the particle surface, with the LC segment associated with the particles and the alkyl groups "dissolved" in the liquid phase, causing entropic (or steric) stabilization.
For a comparison study, non-liquid crystalline polyester XIIIc was used to replace XIIIb to prepare dispersion. When a hot solution of polyester XIIIc and polyester XIIIa (XIIIc:XIIIa=9.1) in xylene was cooled down with shaking, solid species precipitated out. No homogeneous dispersion, as for XIIIb and XIIIa in xylene system, was obtained. The crystallization of the insoluble polyester in a transitional non-aqueous dispersion caused flocculation, possibly because the dispersant (soluble polymer) could not co-crystallize with the insoluble polyesters and was excluded from the crystal. Such results suggest that in order to form stable dispersion in the current system, the soluble polyester should have a segment with similar (LC) structure to the insoluble polyester. This common structure provides the sites for association between the soluble and insoluble polyesters, possibly through LC association.
Viscosity vs. Content of Polyester XIIIa In The Dispersions
Viscosity of the dispersions varies with the content of the polyester XIIIa in dispersions of the blends of polyesters XIIIa and XIIIb. In three different concentrations of the blend (50, 60 and 70%), the increase of XIIIa content caused the viscosity to decrease to a minimum and then increase again. Since polyester XIIIa is insoluble in xylene, it must stay as dispersion (in solid particles), possibly stabilized by soluble oligomer molecules. Apparently, the viscosity change is accompanied by the formation of dispersions (solid phase) and the decreasing solution concentration (liquid phase). While not intending to be bound by any theory, this can be explained as follows.
For the same percent solids, with the increase of insoluble polyester XIIIa content, the soluble polyester XIIIb is reduced. Thus, the liquid phase concentration is diluted. If the solid phase (dispersion) were not existing, the solution viscosity would decrease. However, the solid phase (dispersion) also contributes to the viscosity, causing higher viscosity than the liquid phase alone. Therefore, the viscosity change is the net result of both the decrease due to the decreasing liquid concentration and the increase due to the increasing solid phase (dispersion).
It is known that the viscosity of polymer solutions usually increases slowly at lower concentration but increases dramatically at higher concentration. This is also true in dispersions of XIIIb. Experiments demonstrate that at high concentration (50-70%), with 10% concentration increase, the viscosity increases 260%. Thus, at higher concentration, a small reduction in the concentration would reduce the viscosity greatly. On the other hand, for a solid dispersion in liquid at lower concentration (0.30%), the viscosity varies with the solid volume fraction (V) according to the Vand equation (an extension of the Einstein equation): ##EQU1## According to this equation, for a dispersion at lower concentration (0-30%), the viscosity only increases moderately with the concentration. For example, when the dispersion concentration increases from 0% to 10%, the viscosity increases 32% (2.5×0.1+7.35×0.1); and when the concentration increases from 10% to 20%, the viscosity increases 47%. Such a viscosity increase is much less than the increase for a polymer solution at higher concentrations (260% increase in viscosity with 10% concentration increase (from 60% to 70%)). Thus, for the same percent solids at higher polymer concentration, with the increase in the solid phase (dispersion) to a certain extent, the viscosity should decrease.
The solid phase may be higher than expected when only considering the insoluble polymer, since some soluble polyester XIIIb may co-crystallize with polyester XIIIa and involve in the solid (dispersion) phase. Thus, the viscosity reduction may be different from prediction of the Vand equation.
The viscosity of the dispersions of blends of polyesters XIIIa and XIIIb increased again when the insoluble polyester content (relative to the total polyester) exceeded 10-20%. This is possibly because at higher dispersion concentrations the particles are too crowded to move freely, causing higher viscosity.
Liquid Crystallinity of Polyesters XIIIa and XIIIb
The DSC thermogram of polyester XIIIa showed three first-order transitions on heating and three first-order transitions on cooling, indicating its multimesomorphous property. The lower-temperature mesophase is possibly smectic and the higher-temperature mesophase is possibly nematic. The different intensity ratios among the three peaks on heating from those on cooling can be explained in terms of the different relaxation rates of the transitions on heating from those on cooling. The three transitions on heating are about the same possibly because all the three relaxation rates on heating are fast enough to be well observed at the experimental heating rate (assume the three transition energies are about the same); while on cooling the two lower transitions are much weaker than the higher-temperature transitions possibly because the relaxation rates of the two lower-temperature transitions are too low to be observed fully at this experimental cooling rate. This difference in the transition intensity ratios on heating from on cooling also indicates the good purity of the polyesters, since if each transition were due to different polyesters (varying in structure or molecular weight) there should be no difference between the transition ratios on heating and on cooling.
Polyester XIIIb was non-transparent semi-solid or viscous liquid at room temperature and transparent liquid at elevated temperatures (above 50°-60° C.). The non-transparency at room temperature is possibly due to crystal (possibly LC) formation. The DSC thermogram of polyester XIIIb has three first-order transitions (2.6°, 43.0° and 59.0° C.) and a second-order transition (-18.3° C.) on heating, while no transitions were observed on cooling above 50° C. (below 50° C., DSC can not be carried out on cooling in this instrument). The two transitions at 43.0° and 59.0° C. are possible due to the phase transitions of the LC units, since the LC unit is the only part in the XIIIb molecule with such high transition temperatures (the melting/freezing point for pure Glydexx N-10 is less than -20° C.) and these two transition temperatures are close to the transition temperatures of polyester XIIIa. Also, these transition temperatures are in the same range for polyester XIIIb to become transparent. Thus these transitions must be crystal or LC transitions. The somewhat lower transition temperatures of the LC units in polyester XIIIb are due to the modification by soft spacers (Glydexx N-10). The clearly separated two transitions due to polyester XIIIa units in polyester XIIIb indicates its LC behavior, the upper temperature being clearing point and the lower temperature being melting point. The second-order transition (-18.3° C.) is typical of glass transition. The first-order transition at 2.6° C. is possibly the melting point due to the non-LC part of the material. This temperature is higher than the melting/freezing temperature of pure Glydexx N-10 (-20° C.) due to the attachment of this molecule onto the high Tm units which makes the Glydexx N-10 unit less mobile, causing higher transition temperature.
Morphology of Polyester XIIIc: A Non-LC Oligomer With Structure Similar to Polyester XIIIb
Polyester XIIIc was synthesized as a non-LC oligomer for comparison studies of the LC properties of polyester XIIIb. Polyester XIIIc is transparent semi-solid or viscous liquid at room temperature instead of turbid semi-solid or viscous liquid as for polyester XIIIb, which may be due to non-crystallinity of XIIIc above room temperature. The DSC thermogram of polyester XIIIc does not have first-order double or triple transitions from -60° to 150° C., indicating non-liquid crystallinity of this polymer. The sharp first-order single transition at 8.2° C. is typical of a melting point, while the weak and broad transition at -17.6° C. is possibly a glass transition. Thus, the two carboxylic acids being in the para positions (as for terephthalate) is important for the formation of LC-like properties; similar polymers with carboxylic acids in the meta positions will not be liquid crystalline.
Co-Crystallization of Polyester XIIIb with Polyester XIIIa
In order to clarify the possible co-crystallization of polyester XIIIb with Polyester XIIIa in the dispersions, a DSC is carried out for the dry mixed sample (no solvent) containing polyester XIIIa and polyester XIIIb with different polyester XIIIa content. A dry sample is used in the DSC experiment because of the instrumental limitation. However, from the dry samples, we can know the co-crystallizability of polyester XIIIa with polyester XIIIb and thus predict the possible co-crystallization in the dispersions.
DSC thermograms of mix-melted samples of polyesters XIIIa and XIIIb were taken with different polyester XIIIa content. The DSC plot for pure polyester XIIIa and polyester XIIIb were also compared with DSC thermograms of the blends. Both the transitions due to polyester XIIIa (higher temperature region) and polyester XIIIb (lower temperature region) are seen in the thermograms for the mixed samples, indicating the existence of two types of LC domains. However, the transition temperatures for the domain for polyester XIIIb is higher than for the pure polyester XIIIa and increase with the increasing polyester XIIIa content; while the transition temperatures for the domain for polyester XIIIa is lower than for the pure polyester XIIIb and decrease with decreasing polyester XIIIa content. Also the transition temperatures are generally broader than for the pure oligomers. This indicates the involvement of the other polyester in either LC domain. That is, a polyester XIIIa LC domain also contains some polyester XIIIb molecules, while a domain for polyester XIIIb also contains some XIIIa polyester molecules. For the dispersions, the involvement of the XIIIb polyester in a XIIIa polyester LC domain will lead to the stabilization of the dispersion, since the XIIIb polyester also contains soft alkyl groups which will cause steric stabilization of the dispersions.
Crossed Polarizing Microscope Studies of Dispersions of the XIIIa and XIIIb Polyester Blends
Microscope studies have been carried out for blends of XIIIa and XIIIb polyesters in xylene dispersions with different XIIIa polyester content (10, 20 and 30 weight percent). The dispersions were 50 weight percent polyesters. Original wet samples were directly used for the studies. Without crossed polarizing lenses, the samples were found to be transparent. Thus polarizing lenses were used for all the samples, and only the birefrigerant parts of the samples showed up in the microscope observation.
Polyester XIIIb in xylene showed a few scattered birefrigerant particles in the solution or dispersion; while with the addition of polyester XIIIa, more birefrigerant particles were presented which indicates the induced LC formation by the XIIIa polyester. The particle size was very small at lower XIIIa polyester content; while larger particle size was observed when the XIIIa polyester content is high. With higher XIIIa polyester content, the particles are stabilized by less amount of polyester XIIIb and have more chance to coalesce with each other; while at lower polyester XIIIa content the particles are stabilized by more polyester XIIIb and remain as smaller particles. This also explains the better stability of the dispersions with lower polyester XIIIa content. For the dispersions with 10 and 15% polyester XIIIa contents, Brownian motion indicates these dispersions are deflocculated. This Brownian motion may also cause stability of the dispersions.
Properties of HMMM-Cross-linked Films Made From Polyesters XIIIa and XIIIb
Table 5 in this Example shows the film properties of the polyesters cross-linked with hexakis (methoxymethyl) melamine resin (HMMM). No significant differences in film properties were observed with different polyester XIIIa contents. This indicates that polyester XIIIb gives as good properties as polyester XIIIa does. Although there are some soft groups on polyester XIIIb, it has 4 functional groups instead of 2 as for polyester XIIIa. More functional groups will give higher and more efficient cross-linking, and thus compensate the softness caused by the alkyl groups on polyester XIIIb.
TABLE 5__________________________________________________________________________Film properties of dispersions of XIIIa and XIIIbpolyester blends cross-linked with HMMM.*PolyesterXIIIa in Film Tukon Pen- Cross-XIIIa and thick- hard- cil Reverse hatch Resist-b Blend ness ness Hard- Impact Adhesion ance to(wt. %) (mil) (KHN) ness (in. lb.) (%) Acetone Appearance__________________________________________________________________________0 1.4 11 3H/4H 160 100 Excellent Transparent10 1.5 12 3H/4H 152 100 Excellent Transparent20 1.4 11 3H/4H 160 100 Excellent Transparent30 1.4 12 3H/4H 160 100 Excellent Transparent40 1.4 12 3H/4H 160 100 Excellent Transparent__________________________________________________________________________ *Coating composition: oligoesters:HMMM:pTSA = 70:30:0.30 (w/w); solids % = 70% (wt. % in xylene); baking schedule: 150° C. for 20 minutes
All the films are transparent and very glossy. Because these LC oligomers have lower melting and clearing points than the curing temperature, they were cured from isotropic state. The cross-linked films may remain isotropic or have smaller LC domains (smaller than light wavelength). Such a film appearance is very desirable in coatings.
All the films showed good hardness and excellent flexibility. However, the Tukon hardness of these films was not as high as for other LC coatings, possibly because the LC domains did not form after cross-linking.
Stable non-aqueous dispersions can be formed from blends of a polyester of the general formula and a modified polyester. LC association between the soluble and insoluble polymers and the steric effect of the soluble polymer may be the causes of the dispersion stabilization.
At the same polyester blend concentration, the insoluble LC polyester induced dispersions showed lower viscosity than the pure soluble polyester solution. The viscosity showed a minimum when the insoluble polyester content is 10-20% of the total polyester content. This rheological behavior can be explained in terms of Vand equation together with the fact that the viscosity of polyester solutions at high concentrations increases significantly with the concentration increase. This viscosity reduction is important for making higher solids coatings.
HMMM-cured films of the dispersions of the polyester/modified polyester blend showed good mechanical properties and excellent appearance (transparent). This shows that the dispersion formation does not affect the film appearance.
EXAMPLE XIV
(Reactive Diluent+Diol Polyester)
XIV(a) - Synthesis of Reactive Diluent
A reactive diluent having the formula ##STR57##
wherein R=aliphatic group with R 3 having a total of eight carbon atoms, was made as follows as a reaction product of terephthalic acid (TPA) and the mono-oxirane, Glydexx N-10. ##STR58##
33.2 g TPA (0.20 mol), 100 g Glydexx N-10 (0.40 mol), and 0.2 g triphenyl benzyl phosphonium chloride (TPBPC) (0.5 g/mol) were charged into a 250-mL flask equipped with thermometer, stirrer, and water condenser. The mixture was heated with stirring to about 220° C. in about one hour and kept at this temperature for 10 to 20 minutes (the TPA solid phase disappeared quickly after the temperature reached 220° C., indicating complete reaction). The material was poured out into a 300-mL beaker, and washed with several portions of petroleum ether which was added carefully with stirring. The supernatant liquid was decanted after each washing. The washed samples were then heated to 100° C. with stirring on a heating plate in a hood to remove all the solvent. The final product XIVa was light yellow viscous liquid. ICI viscosity: 2.4 Pa.s. at 50° C., and >10 Pa.s. at 25° C. Yield was 92.5%.
The diol polyester having the formula XIIIa was made by a procedure similar to that described in XIIIa for preparation of the non-aqueous dispersion. A second diol ester having the formula ##STR59## also was prepared for further preparation of a non-aqueous dispersions.
Preparation of Non-Aqueous Dispersions Using Reactive Diluent XIVa
Dispersion of Polyester XIIIa in Reactive Diluent XIVa ##STR60##
1.0 g of polyester XIIIa and 1.0 g reactive diluent XIVa were charged into a glass vial (uncovered) and heated on a Bunsen burner until the polyester XIIIa completely melted. 1.5 g toluene was added slowly, forming a homogeneous solution. The solution cooled down at room temperature with shaking (or with ultrasonication). Dispersion was gradually formed during cooling. This dispersion was very stable at room temperature and exhibited shear thinning and thixotropic behavior.
Dispersion of Polyester XIVb+Reactive Diluent XIVa ##STR61##
1.0 g of polyester XIVb and 1.0 g of reactive diluent XIVa were charged into a glass vial (uncovered) and heated on a Bunsen burner until the polyester completely melted. 2.0 g xylene was added slowly, forming a homogeneous solution. 1.0 g HMMM was then dissolved in the solution. The solution was well shaken while cooling down at room temperature. Dispersion was gradually formed during cooling. This dispersion was very stable at room temperature and exhibited shear thinning and thixotropic behavior.
Clear Coatings
Formulated coatings were prepared with similar procedure as described above. The formulated coatings were cast as films on a 1,000 Bonderite steel panel and baked in an oven at 150° C. for 30 minutes.
______________________________________Formulation 1: Polyester XIIIa 1.0 g Reactive diluent XIVa 1.0 g HMMM 1.0 g Toluene 1.5 g p-TSA 0.006 gFilm properties: Tukon hardness 10.0 KHN Pencil hardness 3H/4H Reverse impact 160 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, no defectFormulation 2: Polyester XIIIa 1.0 g Reactive diluent XIVa 1.5 g HMMM 1.5 g Toluene 1.5 g p-TSA 0.006 gFilm properties: Tukon hardness 10.0 KHN Pencil hardness 3H/4H Reverse impact 120 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, no defectFormulation 3: Polyester XIIIa 1.5 g Reactive diluent XIVa 1.0 g HMMM 1.0 g Toluene 2.5 g p-TSA 0.006 gFilm properties: Tukon hardness 12.0 KHN Pencil hardness 4H/5H Reverse impact 160 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, but poor levelingFormulation 4 (cross-linked by polyisocyanate): Polyester XIIIa 1.0 g Reactive diluent XIVa 1.5 g Mondur CB-60 2.5 g Toluene 1.5 g 150° C./ 90° C. 30 min. 2/hrs.Film properties: Tukon hardness 18.0 KHN 18.0 KHN Pencil hardness 4H/5H 4H/5H Reverse impact 160 in-lbs. 160 in-lbs. Direct impact 160 in-lbs. 160 in-lbs. Film thickness 1.0 mil 1.0 mil Appearance glossy, fuzzy- no defects looking______________________________________
Pigmented Coatings
Polyester XIIIa and the reactive diluent XIVa were charged into a 300-mL aluminum can. The polyester was melted by heating on a Bunsen burner with care. Half of the calculated amount of toluene was added, followed by the HMMM and an AB dispersant, Elvacite AB-1040. While cooling down at room temperature, the ingredients were shook until the transparent material became a milky dispersion. A TiO 2 white pigment from du Pont, Tipure R-960, and p-TSA were added. The formulated coating was dispersed on a high speed dispersing mill for 30 minutes. The second half of the toluene was added during the dispersing. The formulated coating composition exhibited thixotropic behavior.
The formulated coating compositions were cast as a film on a 1,000 Bonderate steel panel and baked at 150° C. for 30 minutes (Formulation 1) or 10 minutes (Formulation 3, with more catalyst added).
______________________________________Formulation 1: Polyester XIIIa 30.0 g Reactive diluent XIIIa 30.0 g HMMM 30.0 g Tipure R-960 48.0 g Toluene 90.0 g p-TSA 0.30 g Elvacite AB-1040 3.60 g Byk-020 (defoamer 1 drop from Mallinckrodt)Film properties: Tukon hardness 10.0 KHN Pencil hardness 6H/7H Reverse impact 40 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance no evident defects, medium glossFormulation 2: Polyester XIIIa 10.0 g Reactive diluent XIIIa 20.0 g HMMM 15.0 g Tipure R-960 22.5 g Toluene 45.0 g p-TSA 0.225 g Elvacite AB-1040 3.38 gFilm properties: Tukon hardness 10.0 KHN Pencil hardness 3H/4H Reverse impact 80 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance fairly glossy______________________________________
EXAMPLE XV
Nonaqueous Dispersion Coatings Using A Double Ring Cycloaliphatic Ester As A Reactive Diluent
The LC-like polyester XIIIa of Example XIII having the structure: ##STR62## and a non-LC composition (K-Flex 188 commercially available from King Industry) having the structure: ##STR63## were made into nonaqueous conversion coating compositions and studied as described below.
Preparation of Nonaqueous Dispersion
Example 1 ##STR64##
1.0 g XIIIa and 1.0 g K-Flex 188 were charged into a glass vial (uncovered) and heated on a Bunsen burner until XIIIa completely melted. 1.5 g toluene was added slowly, forming a homogenous solution. The solution was cooled at room temperature with good shaking (or with ultrasonication). Dispersion was gradually formed during cooling. After several weeks of storage, the dispersion separated into a dilute top phase and a concentrated bottom phase (no solid precipitates were observed); the solution returned to homogeneous dispersion after minor shaking or stirring. This dispersion was very stable at room temperature and no change was observed 3 months after preparation. The dispersion exhibited thixotropic behavior.
Example 2 ##STR65##
1.0 g XIIIa and 1.0 g K-Flex 188 were charged into a glass vial (uncovered) and heated on a Bunsen burner until the oligoester completely melted. 2.0 g xylene was added slowly, forming a homogenous solution. 1.0 g Resimene 746 was then dissolved in the solution. The solution was well shaken while cooling down at room temperature. Dispersion was gradually formed during cooling. This dispersion was very stable at room temperature and exhibited thixotropic behavior. No change was observed after 3 months except that the dispersion separated into a dilute top phase and a concentrated bottom phase; the phase separation disappeared after minor shaking or stirring.
Clear Coatings
A formulated coating composition was prepared with similar procedure as described above. It was cast film on a 1,000 Bonderate steel panel and baked in an over at 150° C. for 20 minutes (25° C. for 1 day and 70° C. for 2 h for Example 4).
Example 3
______________________________________Formulation: Polyester XIIIa 1.0 g K-Flex 188 1.0 g Resimene 746 1.0 g Xylene 1.5 g p-TSA 0.006 gFilm properties: Tukon hardness 14.0 KHN Pencil hardness 4H/5H Reverse impact 160 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, no defect______________________________________
Example 4
______________________________________Formulation: Polyester XIIIa 1.0 g K-Flex 188 1.5 g Resimene 746 1.5 g Xylene 1.5 g p-TSA 0.006 gFilm properties: Tukon hardness 12.0 KHN Pencil hardness 3H/4H Reverse impact 160 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, no defect______________________________________
Example 5
______________________________________Formulation: Polyester XIIIa 1.5 g K-Flex 188 1.0 g Resimene 746 1.0 g Xylene 2.5 g p-TSA 0.006 gFilm properties: Tukon hardness 15.0 KHN Pencil hardness 4H/5H Reverse impact 120 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance glossy, but poor leveling______________________________________
Example 6 (cross-linked by an isocyanate prepolymer)
______________________________________Formulation: Polyester XIIIa 1.0 g K-Flex 188 1.5 g Mondur CB-60 2.5 g Dibutyltin dilaurate 0.008 g Toluene 1.5 g 70° C./ 25° C./1 day 2 hrs.Film properties: Tukon hardness 16.0 KHN 20.0 KHN Pencil hardness 3H/4H 4H/5H Reverse impact 160 in-lbs. 160 in-lbs. Direct impact 160 in-lbs. 160 in-lbs. Film thickness 1.0 mil 1.0 mil Appearance glossy, fuzzy- no defect looking______________________________________
Pigmented Coatings Cross-linked by HMMM
Polyester XIIIa and K-Flex 188 were charged into a 300 mL aluminum can and were melted by heating on a Bunsen burner with care. Half of the calculated amount of xylene was added, followed by Resimene 746 and Elvacite AB-1040. While cooling down in the atmosphere, the solution was kept shaking until the transparent material became a milky dispersion. Tipure R-960 and p-TSA were added. The coating composition was dispersed on a high speed dispersing mill for 30 minutes. The second half of the xylene was added during the dispersing. The formulated coating composition was very stable; no phase separation was observed after 3 months. The formulated coating composition exhibited thixotropic behavior.
The formulated coating compositions were cast film on a 1,000 Bonderate steel panel and baked at 150° C. for 20 minutes.
Example 7
______________________________________Formulation: Polyester XIIIa 10.5 g K-Flex 188 10.0 g HMMM (Resimene 746) 10.0 g TiO.sub.2 White Pigment 15.0 g (Tipure R-960) Xylene 30.0 g p-TSA 0.15 g Dispersant 2.00 g (Elvacite AB-1040) Defoamer (Byk-020) 1 dropFilm properties: Tukon hardness 14.0 KHN Pencil hardness 7H Reverse impact 80 in-lbs. Direct impact 160 in-lbs. Film thickness 0.7 mil Appearance med. gloss, some pinholing______________________________________
Example 8
______________________________________Formulation: Polyester XIIIa 10.0 g K-Flex 188 20.0 g Resimene 746 15.0 g Tipure R-960 22.5 g Toluene 40.0 g p-TSA 0.23 g Elvacite AB-1040 3.38 g Byk-020 2 dropsFilm properties: Tukon hardness 22.0 KHN Pencil hardness 7H Reverse impact 80 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance fairly glossy______________________________________
Pigmented Coatings Cross-linked by an Isocyanate Prepolymer
Polyester XIIIa and K-Flex 188 were charged into a 300 mL aluminum can and were melted by heating on a Bunsen burner with care. Half of the calculated amount of toluene was added, followed by Mondur CB-60 and Elvacite AB-1040. While cooling down at room temperature, the solution was kept shaking until the transparent material became a milky dispersion. Tipure R-960, Byk-020, and dibutyltin dilaurate were added. The paint was dispersed on a high speed dispersing mill for minutes. The second half of the toluene was added during the dispersing. The formulated coating composition was very stable; no phase separation was observed. The formulated coating composition exhibited thixotropic behavior.
The formulated coating compositions were cast film on a 1,000 Bonderate steel panel and baked at 70° C. for 2 h.
Example 9
______________________________________Formulation: Polyester XIIIa 10.0 g K-Flex 188 20.0 g Mondur CB-60 30.0 g Tipure R-960 22.5 g Toluene 30.0 g p-TSA 0.23 g Dibutyltin dilaurate 0.18 g Elvacite AB-1040 3.00 g Byk-020 2 dropsFilm properties: Tukon hardness 22.0 KHN Pencil hardness 7H Reverse impact 80 in-lbs. Direct impact 160 in-lbs. Film thickness 1.0 mil Appearance fairly glossy______________________________________
EXAMPLE XVI
Properties as to viscosity, yield stress and sagging were studied as to the following compounds
A LC-like Composition (a) having the formula ##STR66## which was previously described in connection with polyester VC of Example V;
A LC-like Composition (b) having the formula ##STR67## which was previously described in connection with polyester VC of Example V;
A LC-like Composition (c) having the formula ##STR68## and which was previously described in connection with polyester VIIF;
A nonliquid crystalline Composition (d) having the formula ##STR69## which was generally described in connection with polyester XIII C;
A LC-like Composition (e) having the formula ##STR70## which composition was generally described in Example V.
A nonliquid crystalline Composition (f) having the general formula ##STR71## which was generally described in Example XIV; and
A nonliquid crystalline Composition (g) K-Flex (non-LC; commercial product from King Industry) which has the general formula ##STR72## and
A nonliquid crystalline Composition (h) which has the general formula ##STR73##
Temperature Dependence of the Viscosity of the LC-Like Oligomers
The viscosity of the LC polymers was determined with an ICI viscometer at several temperatures from 25° to 150° C. For thixotropic samples, the steady viscosity was recorded. Tables 6-9 show the viscosity vs. temperature for several LC polymers.
TABLE 6______________________________________Viscosity vs. Temperature for Composition (a)______________________________________Temperature (°C.) 25 50 75 100 125 150Viscosity (poise) 1.25 1.00 0.45 0.85 0.45(heating)Viscosity (poise) 0.70 0.20 1.40 0.82 0.45(cooling)______________________________________
TABLE 7______________________________________Viscosity vs. Temperature for Composition (b)______________________________________Temperature (°C.) 50 75 100 (115)* 125 150Viscosity (poise) >100 1.5 0.4 46.0 2.5 1.2(heating)Viscosity (poise) >100 1.5 0.6 12.0 2.5 1.1(cooling)______________________________________ *Estimated temperature.
TABLE 8______________________________________Viscosity vs. Temperature for composition (c)______________________________________Temperature (°C.) 25 50 75 100 125 150Viscosity (poise) >100 34.0 >100 29.5 7.5 1.5(heating)Viscosity (poise) >100 89.5 >100 36.5 9.0 1.5(cooling)______________________________________
TABLE 9______________________________________Viscosity vs. Temperature for Composition (e)______________________________________Temperature (°C.) 25 50 (65)* 75 100 125Viscosity (poise) >100 12.0 15.5 2.0 0.2(heating)Viscosity (poise) 45 2.0 57.0 16.2 2.5 0.1(cooling)______________________________________ *Estimated temperature.
It is seen from Tables 6-7 of this Example that for the LC-like polyesters the viscosity first decreases and then increases with increasing temperature until a maximum. While not intending to be bound by any theory, the unusual rheological behavior has been explained as follows. In the LC state, the polymers are oriented and may exhibit much lower viscosity than nonoriented polymers. With increase of temperature, the polymers become isotropic and the viscosity increases dramatically. On the other hand, there is a general tendency for the viscosity of polymers to decrease upon increasing temperature due to thermal motion. The results of these competing effects lead to a maximum viscosity upon increasing temperature. Alternate explanations, however, are possible.
The LC-like polymers of the invention were compared with the non-LC counterparts. The viscosity of several non-LC polymers with similar structures to the LC-like polymers of the invention was measured. Tables 10 and 11 of this Example show the temperature dependence of Composition (d) and Composition (h) (non-LC counterparts of Composition (c) and Composition (a) respectively). It is seen that the viscosity decreases steadily with increasing temperature, in contrast to the unusual viscosity behavior of the LC-like polymers.
TABLE 10______________________________________Viscosity vs. Temperature for Composition (d) (non-LC)______________________________________Temperature (°C.) 25 50 75 100 125 150Viscosity (poise) >100 >100 >100 29.0 7.5 1.5(heating)Viscosity (poise) >100 >100 >100 28.0 5.4 1.8(cooling)______________________________________
TABLE 11______________________________________Viscosity vs. Temperature for Composition (h) (non-LC)______________________________________Temperature (°C.) 25 50 75 100 125 150Viscosity (poise) >100 24.5 2.2 0.5 0.1 0.1(heating)Viscosity (poise) >100 28.5 2.4 0.5 0.1 0.1(cooling)______________________________________
Thixotropic Behavior of LC-Like Polymers
Table 12 of this Example shows the time dependence of the ICI viscosity of Composition (c) at different temperatures. The viscosity in the LC-like region (around 50° C.) decreases with time to a steady value, indicating thixotropic properties of the LC-like polymers. The viscosity decrease is possibly due to break-up of certain structure (possibly LC association) with time.
TABLE 12______________________________________Viscosity vs. Shear Time of Composition (c) at DifferentTemperature.Temperature (°C.) Visc. (poise)/Shearing Time (second)______________________________________25 >100/0 >100/30 -- --50 >100/0 30/26 20/60 20/12075 >100/0 100/30 -- --100 48/0 48/30 48/60 48/120125 13/0 13/30 13/60 13/120150 4/0 4/30 4/60 4/120______________________________________
Yield Stress of LC-Like Polymers
The yield stress was determined by measuring the relative flow distance of the polymers at different temperatures. 0.2 g of sample was placed on an aluminum panel sitting at 45° angle and the flow distance of the oligomers after 10 minutes was recorded.
TABLE 13______________________________________Flow Distance of Composition (c) At Different Temperatures______________________________________Temperature (°C.) 25 50 60 90 150Flow distance 0.0 0.0 6.4 6.0 9.5(cm)/10 min.______________________________________
Table 12 of this Example shows the flow distance of Composition (c) after 10 minutes at different temperatures. Although the polymer is viscous liquid or semi-solid at room temperature, no flow was observed up to 50° C., indicating yield stress of the polymer below about 50° C. At 60° C. and above, Composition (c) flowed, indicating zero yield stress. Since the transition temperature of Composition (c) is 43.0 (T m ) and 59.0° C. (T c ) (FIG. 4), the flow distance data suggest that the yield stress is possibly due to LC association.
Sagging Resistance of Coatings Formulated from LC-Like Polymers.
Testing Methods
The method of ASTM 4400 was used except that an aluminum panel instead of a chart was used because of higher baking temperature. The sample was cast on an aluminum panel using Leneta anti-sag meter (The Leneta Company), and the panel was set 90° to the horizontal direction at the testing temperature for a designated time (such as 20 minutes). The thickness of the thickest unsagged strip was recorded as the anti-sagging value.
Sagging Resistance of Solvent Coatings at Elevated Temperature
Example 1 (LC)
______________________________________Formulation: Composition (c) 2.5 g HMMM (Resimene 746) 0.5 g Para toluene 0.006 g Sulfonic acid (p-TSA) Xylene 2.0 g p-TSA 0.006 g______________________________________
Baking conditions: 150° C. for 20 minutes.
Sagging Resistance: 6 mil
Appearance of coating: glossy.
Example 2 (Non-LC counterpart of Example 1)
______________________________________Formulation: Composition (d) 2.5 g Resimene 746 0.5 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 3 mil.
Appearance of coating: glossy.
Example 3 (LC)
______________________________________Formulation: Composition (e) 2.0 g Resimene 746 1.0 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes. Sagging Resistance: 10 mil. Appearance of coating: glossy.
Example 4 (LC)
______________________________________Formulation: Composition (c) 1.5 g Polyisocyanate based 1.9 g upon toluene diiso- cyanate blocked with ε-Caprolactam (Desmodur BL-1185A from Mobay Corporation) Dibutyltin dilaurate 0.007 g Toluene 1.0 g______________________________________
Curing condition: 70° C. for 1 h.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Sagging Resistance of Solvent Coatings at Room Temperature
Example 5 (LC)
______________________________________Formulation: Composition (c) 2.5 g Mondur CB-60 1.6 g Dibutyltin dilaurate 0.008 g Toluene 2.0 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: 10 mil.
Appearance of coating: glossy.
Example 6 (Non-LC) counterpart of Example 4
______________________________________Formulation: Composition (c) 2.5 g Mondur CB-60 1.6 g Dibutyltin dilaurate 0.008 g Toluene 2.0 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: <3 mil.
Appearance of coating: glossy.
Sagging Resistance of LC-Like Nonaqueous Dispersion Coatings at Elevated Temperature
Example 7 (LC)
______________________________________Formulation: Composition (a) 1.0 g Composition (f) 1.0 g Resimene 746 1.0 g p-TSA 0.006 g Xylene 1.5 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Example 8 (Non-LC)
______________________________________Formulation: Composition (f) 2.0 g Resimene 746 1.0 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: <3 mil.
Appearance of coating: glossy.
Example 9 (LC)
______________________________________Formulation: Composition (a) 1.0 g Composition (g) 1.0 g (K-Flex 188) Resimene 746 1.0 g p-TSA 0.006 g Xylene 1.5 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Example 9 (Non-LC counterpart of Example 9)
______________________________________Formulation: Composition (g) 2.0 g (K-Flex 188) Resimene 746 1.0 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: <3 mil.
Appearance of coating: glossy.
Sagging Resistance of Nonaqueous LC-Like Dispersion Coatings Cured at Room Temperature
Example 11 (LC)
______________________________________Formulation: Composition (a) 1.0 g Composition (f) 1.5 g Dibutyltin dilaurate 0.008 g Mondur CB-60 2.5 g Toluene 1.5 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: 12 mil.
Appearance of coating: fairly glossy.
Example 12 (Non-LC counterpart of Example 18)
______________________________________Formulation: Composition (f) 2.5 g Mondur CB-60 2.5 g Dibutyltin dilaurate 0.008 g Toluene 2.0 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: <3 mil.
Appearance of coating: glossy.
Example 13 (LC)
______________________________________Formulation: Composition (a) 1.3 g Composition (g) 1.2 g (K-Flex 188) Dibutyltin dilaurate 0.008 g Mondur CB-60 2.5 g Toluene 1.5 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: 10 mil.
Appearance of coating: fairly glossy.
Example 14 Non-LC counterpart of Example 20)
______________________________________Formulation: Composition (g) 2.5 g (K-Flex 188) Mondur CB-60 2.5 g Dibutyltin dilaurate 0.008 g Toluene 2.0 g______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: <3 mil.
Appearance of coating: glossy.
Improved Sag Resistance of Composition (c) (Soluble LC-Like) Coatings with Addition of Composition (a) (Insoluble LC)
Example 15 (Soluble LC, the same as Example 1)
______________________________________Formulation: Composition (c) 2.5 g Resimene 746 0.5 g P-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 6 mil.
Appearance of coating: glossy.
Example 16 (Addition of Composition (a) into Composition (c))
______________________________________Formulation: Composition (c) 1.8 g Composition (a) 0.2 g Resimene 746 1.0 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 8 mil.
Appearance of coating: glossy.
Example 17 (Addition of Composition (a) into Composition
______________________________________Formulation: Composition (c) 1.2 g Composition (a) 0.8 g Resimene 746 1.0 g p-TSA 0.006 g Xylene 2.0 g______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Sagging Resistance of Pigmented Coatings at Elevated Temperature
Example 18 (LC)
______________________________________Formulation: Composition (c) 30.0 g Resimene 746 15.0 g TiO.sub.2 White Pigment 22.5 g Tipure R-960 from du Pont) p-TSA 0.23 g Xylene 40.0 g Dispersant 3.4 g (Elvacite AB-1040) Defoamer (Byk-020) 2 drops______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 10 mil.
Appearance of coating: glossy.
Example 19 (LC)
______________________________________Formulation: Composition (c) 20.0 g Resimene 746 10.0 g Tipure R-960 26.7 g p-TSA 0.17 g Toluene 40.0 g Elvacite AB-1040 2.0 g Byk-020 1 drop______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: fairly glossy.
Example 20 (LC)
______________________________________Formulation: Composition (a) 30.0 g Composition (f) 40.00 g Resimene 746 30.00 g Tipure R-960 48.0 g p-TSA 0.03 Xylene 90.0 g Elvacite AB-1040 3.6 g Byk-020 1 drop______________________________________
Baking condition: 150° C. for 20 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: fairly glossy.
Example 21 (LC)
______________________________________Formulation: Composition (a) 10.03 g Composition (g) 20.0 g (K-Flex 188) Resimene 746 10.00 g Tipure R-960 15.00 g p-TSA 0.15 a Xylene 30.0 g Elvacite AB-1040 2.0 g______________________________________
Baking condition: 150° C. for 30 minutes.
Sagging Resistance: 12 mil.
Appearance of coating: fairly glossy.
Sagging Resistance of Pigmented Coatings at Lower or Room Temperature
Example 22 (LC)
______________________________________Formulation: Composition (c) 16.0 g Mondur CB-60 14.0 g Dibutyltin dilaurate 0.05 g Tipure R-960 20.0 g Toluene 20.0 g Elvacite AB-1040 1.4 g. Byk-020 1 drop______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Example 23 (LC)
______________________________________Formulation: Composition (e) 26.3 g Mondur CB-60 22.6 g Dibutyltin dilaurate 0.18 g Tipure R-960 39.2 g Toluene 60.0 g Elvacite AB-1040 3.0 g. Byk-020 1 drop______________________________________
Curing condition: room temperature for 1 day.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Example 24 (LC).
______________________________________Formulation: Composition (a) 5.0 g Composition (f) 10.0 g Mondur CB-60 15.0 g Dibutyltin dilaurate 0.05 g Tipure R-960 20.0 g Toluene 20.0 g Elvacite AB-1040 1.4 g. Byk-020 1 drop______________________________________
Curing condition: 70° C. for 12 h.
Sagging Resistance: 12 mil.
Appearance of coating: glossy.
Although the invention has been described with regard to its preferred embodiments, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention which is set forth in the claims appended hereto.
Example XVII
Synthesis of water reducible oligoester derived from dimethylterephthalate with decanediol; coating formulation.
______________________________________ Weight used, g Mole ratio______________________________________Step 1.Decanediol 130.0 1.5Dimethylterephthalate 97.0 1.5Zinc acetate 0.456 0.2% total weightStep 2.Oligoester (from step 1) 65.0 1Trimellitic anhydride (TMA) 3.46 0.3Butyl Cellosolve 13.7 --Dimethylethanolamine 6.0 --Water 67.06 --______________________________________
Step 1: Into a 0.5-L three-neck flask equipped with stirrer, condenser, Dean-Stark trap, thermometer and N 2 gas inlet tube were placed the materials of Step 1. The reaction mixture was stirred and heated under N 2 to 150° C. and then kept at this temperature for 1 hour. CH 3 OH was removed by distillation. After 1 hour the temperature was increased to 230° C.; 90% of theoretical amount of CH 3 OH was collected in the Dean-Stark strap during 5 hours. The reaction material was cooled to about 90° C. and toluene was added. The hot solution was poured into the beaker and cooled to 25° C.; the precipitate which separated was collected, dissolved in CH 2 Cl 2 , reprecipitated by addition of CH 3 OH, and washed with CH 3 OH. The solid was collected and dried in oven at 120° C. overnight; yield was about 78%.
Step 2. The solid from Step 1 was placed in to 250-mL three-neck flask equipped with stirrer, condenser, thermometer and N 2 gas inlet tube. The oligoester was heated to about 175° C. and N 2 gas flow, and TMA was added. The reaction mixture had an acid number of about 50 mg KOH/g. The resulting oligomer was stirred at 170°-180° C. for about 30 minutes and cooled to 130° C. Dimethylethanolamine (2 eq. per mole of trimellitic anhydride) was added at 130° C. and then butyl cellosolve was added. The mixture was stirred at 90°-100° C. for 0.5 hour, and water was added to produce an aqueous dispersion which was used without purification; NVW was determined after 2 hours drying at 120° C.
Coating formulation: The enamel binder was formulated at an oligoester/HMMM/P-TSA weight ratio of 70/30/0.3 and was pigmented at a pigment/binder ratio 0.7 with a TiO 2 pigment. Dow Corning paint additive 57# and BYK 020 were used at 0.1% of total paint weight to prevent foaming, and help leveling and DuPont Elvacite AB + dispersant (2% of pigment weight) was used to help stabilize the TiO 2 . The solvent used in the paint formulation was butyl cellosolve and water. Pigment dispersion was performed on a high speed disk disperser. But the final grind corresponded to a Hegman value of about 4. The paint exhibited a thixotropic nature.
Coatings properties: The coating was drawn down with a wire-wound bar on steel panels and was baked for 20 minutes at 175° C. The baked coatings had discernable ridges and valleys. Poor leveling was attributed to the thixotropic rheology of the liquid coating. The cured coating had the following film properties.
______________________________________Reverse impact 160resistance, in-lbHardness, Knoop 28Solvent resistance, 200acetone double rubs______________________________________
EXAMPLE XVIII
Rheological Behavior Study On LC-Like Oligomers
The six compositions studied were:
1. "K-Flex" 188, a commercial reactive diluent sold by King Industries. It is an isotropic liquid. (See Table I)
2. "Resimene 747" a monomeric HMMM type melamine resin sold by Monsanto. It is also isotropic. (See Table II)
3. A blend of 10GT (decanediol terephthalate Composition (b), m=2), as described in Examples XVI and V, with K188 (50/50 w/w). This is a blend of LC-like 10GT with isotropic K188. (See Table III)
4. A blend of 10GT, K188, and R-747 (1/1/1 w/w/w). This blend is a complete 100% solids coatings binder that would cure if baked high enough. The catalyst normally used was left out to prevent reaction in the rheometer. (See Table IV)
5. A blend of 6GT (hexanediol terephthalate, Composition (a), m=2), as described in Examples XVI and V, K188, and R-747 (1/1/1 w/w/w). (See Table V)
6. A blend of 6 GT with K188 (50/50 w/w). (See Table VI)
Instrument: HAAKE Viscometers-Rotovisco RV 100 (HAAKE Mess-Technik GmbH u. Co., Germany) was used in this study. The temperature was at the range of 25° C. to 125° C. The shear rate was at the range of 252 s -1 to 25200 s -1 . HAAKE viscometer could not measure high viscosity at very high shear rate. This is a limitation of HAAKE viscometer. The viscosities measured by HAAKE viscometer were tabulated below.
TABLE I__________________________________________________________________________Viscosities of K188 at a variety of temperatures.Shear Rate Viscosity (Pa*s)(s-1) T = 114.6° C. T = 88.9° C. T = 68.1° C. T = 56.7° C. T = 25.8° C.__________________________________________________________________________25200 0.05 0.08 0.21 * *22680 0.04 0.08 0.22 * *20160 0.04 0.08 0.22 * *17640 0.04 0.08 0.22 * *15120 0.05 0.08 0.22 * *12600 0.06 0.08 0.23 0.41 *11340 0.07 0.08 0.21 0.42 *10080 0.07 0.08 0.24 0.42 *6300 0.07 0.08 0.43 *5040 0.08 0.09 0.22 0.712520 0.10 0.08 0.57 1.022268 0.11 0.60 1.422016 0.23 0.57 1.441613 0.17 0.251411 0.57 0.23__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
TABLE II__________________________________________________________________________The viscosities of Resimene 747at a variety of temperatures.Shear Rate Viscosity (Pa*s)(s.sup.-1) T = 110.2° C. T = 88.4° C. T = 56.6° C. T = 25.7° C.__________________________________________________________________________25200 0.03 0.05 0.18 *22680 0.03 0.05 0.18 *20160 0.03 0.05 0.18 *17640 0.02 0.05 0.18 *15120 0.02 0.05 0.18 *12600 0.03 0.05 0.20 *11340 0.04 0.05 0.21 *10080 0.04 0.21 *8820 0.04 0.05 0.21 *7560 0.04 0.05 0.22 *6300 0.04 0.22 *5040 0.05 0.23 1.074536 0.05 0.22 1.064032 0.04 0.21 1.043780 0.053528 0.21 0.993402 0.053024 0.05 0.04 0.20 0.992646 0.052268 0.041890 0.04__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
TABLE III__________________________________________________________________________The viscosities of 10GT blendedwith K188 (ratio 1:1 by weight).ShearRate Viscosity (Pa*s)(s.sup.-1) T = 114.8° C. T = 102.7° C. T = 94.4° C. T = 90° C. T = 88.4° C. T = 83.3° C.__________________________________________________________________________25200 0.05 0.10 0.12 * 0.17 *22680 0.06 0.10 0.12 0.26 0.17 *21420 0.26 *20160 0.06 0.10 0.12 0.28 0.18 *17640 0.06 0.10 0.13 0.29 0.18 *15120 0.06 0.10 0.13 0.30 0.19 *12600 0.07 0.11 0.15 0.32 0.31 *11340 0.07 0.11 0.16 0.33 0.32 *10080 0.07 0.12 0.16 0.35 0.33 *8820 0.08 0.12 0.17 0.36 0.34 *7560 0.08 0.13 0.18 0.39 0.36 0.736300 0.07 0.14 0.19 0.41 0.37 0.855040 0.08 0.16 0.23 0.52 0.59 1.014536 0.07 0.16 0.24 0.56 0.61 1.084032 0.06 0.17 0.25 0.60 0.64 1.143528 0.06 0.17 0.25 0.63 0.68 1.233024 0.06 0.18 0.27 0.68 0.73 1.312016 0.11 0.27 0.37 0.91 1.24 1.641814 0.09 0.28 0.38 0.95 1.30 1.651613 0.09 0.30 0.38 0.96 1.33 1.641411 0.09 0.32 0.39 1.02 1.38 1.631209 0.09 0.35 0.38 0.76 1.42 1.61__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
From Table III above, the high-shear viscosities at 88° C. were lower than those at 90° C. The temperature of 88 degrees was the transition temperature from one phase to another phase. This phenomenon is LC-like behavior. The material is shear thinning at temperatures of 102.7° C. and below, but is virtually Newtonian at 114.8° C.
TABLE IV__________________________________________________________________________The viscosities of 10GT blended with K188 andResimene 747 (ratio 1:1:1 by weight).Shear Viscosity (Pa*s)Rate T = T = T = T = T = T = T =(s.sup.-1) 120.4° C. 92.1° C. 86.0° C. 80.0° C. 74.0° C. 63.4° C. 55.5° C.__________________________________________________________________________25200 0.08 * * * * * *22680 0.07 * * * * * *20160 0.08 * * * * * *17640 0.08 0.29 * * * * *16380 0.31 * * * * *15120 0.09 0.29 0.35 * * * *14742 0.31 * * * *13104 0.30 * * * *12600 0.08 0.40 * * * *11466 0.30 * * * *11340 0.08 0.39 * * * *10080 0.08 0.39 0.55 * * *9828 0.29 * * *8820 0.08 0.38 0.54 * * *8190 0.28 * * *7560 0.08 0.36 0.52 0.67 * *6300 0.08 0.35 0.49 0.62 * *5040 0.09 0.34 0.41 0.59 0.71 1.08 *4536 0.09 0.34 0.40 0.57 0.70 1.06 *4032 0.10 0.33 0.40 0.57 0.68 1.03 *3528 0.10 0.32 0.37 0.54 0.65 0.98 *3024 0.11 0.32 0.36 0.49 0.61 0.91 *2520 0.48 0.73 *2268 0.46 0.71 *2016 0.11 0.74 0.46 0.58 0.65 1.14 1.571814 0.11 0.73 0.57 1.39 1.961764 0.59 0.621613 0.12 0.75 0.53 1.35 1.921411 0.12 0.77 0.51 1.30 1.871209 0.13 0.76 0.47 1.23 1.76__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
A dispersion of 10GT in K188 and R747 contains all the elements of a solventless coating binder. As shown in Table IV, such a dispersion exhibits shear thinning at temperatures (86°-92° C.) near the phase transition temperatures of 10GT. At higher temperatures (120° C.) shear thinning is less pronounced, and at lower temperatures (74°-80° C.) the dispersions appear to have approximately Newtonian rheology. Further, at low shear rates (less than about 2100 sec -1 ) the dispersion exhibits a trough in its viscosity-temperature curve, the viscosity increasing from 0.47 Pa.s to 0.76 Pa.s when the dispersion is heated from 80° to 92° C. Thus the unusual rheological characteristics of 10GT persist even when the dispersion is diluted with Newtonian cross-linker and reactive diluent. These characteristics indicate that the dispersion could be applied as a solventless coating at temperatures of 74° to 80° C. with commercial equipment capable of applying coatings at viscosities in the range of 0.5-0.7 Pa.s and would resist sagging when heated at least to 92° C. Alternatively, it could be applied at 92° C. with equipment capable of applying coatings at a viscosity of about 0.3 Pa.s at shear rates above about 3,000 sec -1 and would resist sagging because of its shear thinning characteristics. Thus the unusual theological characteristics are exemplified in the following Tables.
TABLE V__________________________________________________________________________The viscosities of 6GT blended with R747 andK188 (ratio 1:1:1 by weight).Shear Rate Viscosity (Pa*s)(s.sup.-1) T = 101.4° C. T = 83.0° C. T = 70.0° C. T = 60.0° C. T = 50.0° C.__________________________________________________________________________25200 0.11 * * * *22680 0.11 0.24 * * *20160 0.11 0.23 * * *17640 0.11 0.23 * * *15120 0.11 0.24 * * *12600 0.11 0.24 * * *11340 0.11 0.25 0.49 * *10080 0.11 0.25 0.48 * *8820 0.11 0.25 0.48 * *7560 0.11 0.25 0.47 * *6300 0.10 0.25 0.46 * *5040 0.13 0.31 0.58 * *4536 0.13 0.31 0.57 1.20 *4032 0.12 0.31 0.57 1.20 *3528 0.12 0.32 0.57 1.21 1.503024 0.12 0.32 0.59 1.21 1.462016 0.18 0.41 0.85 1.49 1.961814 0.18 0.41 0.85 1.52 1.961613 0.19 0.43 0.87 1.56 1.961411 0.20 0.45 0.89 1.54 1.951209.9 0.20 0.45 0.95 1.52 1.99__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
TABLE VI__________________________________________________________________________The viscosities of K188 blended with 6GT(ratio 1:1 by weight).Shear Viscosity (Pa*s)Rate T = T = T = T = T = T = T =(s.sup.-1) 106.4° C. 94.1° C. 85.8° C. 79.0° C. 75.0° C. 63.0° C. 52.0° C.__________________________________________________________________________25200 0.08 0.14 0.20 * * * *22680 0.08 0.14 0.21 * * * *20160 0.09 0.15 0.21 0.28 * * *17640 0.09 0.15 0.21 0.28 * * *15120 0.09 0.15 0.21 0.28 * * *12600 0.08 0.15 0.21 0.28 * * *11340 0.07 0.15 0.21 0.28 0.48 * *10080 0.07 0.14 0.21 0.25 0.48 * *8820 0.07 0.14 0.21 0.24 0.49 * *7560 0.07 0.13 0.20 0.24 0.49 * *6300 0.06 0.13 0.19 0.50 * *5040 0.11 0.17 0.25 0.34 0.57 * *4536 0.11 0.16 0.25 0.34 0.58 1.21 *4032 0.10 0.16 0.25 0.35 0.58 *3528 0.10 0.16 0.26 0.36 0.60 1.20 *3024 0.10 0.15 0.26 0.37 0.62 1.20 *2016 0.15 0.21 0.32 0.47 0.82 1.40 1.741814 0.15 0.21 0.33 0.47 0.84 1.36 1.741613 0.15 0.21 0.35 0.50 0.85 1.32 1.851411 0.15 0.21 0.38 0.55 0.90 1.30 1.951209.6 0.14 0.22 0.38 0.59 0.95 1.19 1.94__________________________________________________________________________ *The viscosity is too high to be measurable by HAAKE viscometer.
As shown in Tables V and VI, rheological behavior of dispersions of 6GT in K188 and in K188 and R747 is broadly similar to that of the dispersions of 10GT discussed above. In this case the temperature range of greatest shear thinning behavior is lower (70° to 83° C.), and the viscosity in the approximately Newtonian temperature range (50° to 60° C.) is correspondingly higher. The trough in the viscosity-temperature curve was detected.
The various features of this invention which are believed new are set forth in the following claims.
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Polymeric vehicles with liquid crystalline-like properties, solvent dispersible polymeric vehicles, formulated coating compositions with liquid crystalline-like properties and a method for imparting liquid crystalline properties to a coating binder are described. The materials with liquid crystalline-like properties lack structural segments previously regarded as mesogenic.
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FIELD OF THE INVENTION
[0001] This invention generally relates to the art of electrical connectors and, particularly, to an electrical switch connector assembly incorporating a switch to electrically and mechanically connect and disconnect a mating electrical device while maintaining a closed electrical circuit continuously through the connector assembly.
BACKGROUND OF THE INVENTION
[0002] Electrical power is supplied to an individual site by external electrical power line conductors located above or below ground. In a conventional arrangement, electrical power line conductors and electrical load conductors are connected directly to contacts in a watt-hour meter mounted on a building wall. The watt-hour meter is used to measure the electric power drawn through the circuit.
[0003] These meters must be removed periodically for servicing, calibration or replacement. Since the meter is connected to the circuit in series, the removal of the meter will open the circuit. In order to avoid such an open circuit condition after the meter is removed, the input and output electrical conductors to and from the meter must be shorted.
[0004] A number of methods exist to create this short circuit. Two such methods require the skill of an electrical technician. In one instance, the technician is required to place jumper wires between the input and output conductors. In another instance, the technician uses a separate device that connects to all of the input and output conductors at the same time.
[0005] Still another method includes the use of a non-conductive blade inserted between input and output and shorting terminals. When the blade is inserted, the shorting arms are moved out of engagement with the input and output terminals allowing current to flow through the meter. When the blade is removed from between the terminals, the shorting terminals engage respective input and output terminals creating the short that will allow the meter to be removed without opening the circuit. This method works well but there is no provision for wiping the terminals to remove any non-conductive material on the contact surfaces. Also to allow for relatively easy insertion and removal of the non-conductive blade, the spring force in the shorting terminals cannot be too great. If there is any non-conductive material build-up on the contact surfaces, the spring force may not be great enough to force the shorting terminal through the build up resulting in an incomplete or even non-existent electrical connection. Also with a blade there is an extra part that can be lost and there still must be a separate feature that locks the meter with the connector.
[0006] A final method includes a projection on the meter that acts like the blade method described above. Although the projection is part of the meter and does not require a separate part that can get lost, there still must be a separate feature that locks the meter with the connector.
[0007] These prior art methods are expensive since in some cases an expensive technician must be employed or in other instances the meter is more complicated requiring extra parts. Also a consistent electrical contact is not always ensured since the contacting surfaces of the mating switch terminals don't provide any wiping that can remove any non-conductive build up on the mating surfaces of the terminals. Also some of these methods allow the terminals to be exposed to the weather and are also capable of accidental or unintentional contact by testing personnel or other personnel unaware of the exposed electrical potential.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to solving the problems of the prior art by providing an electrical connector assembly that uses a connector with a switch, the connector being readily connected and disconnected both electrically and mechanically to a mating electrical device, such as an electrical meter, while maintaining a continuous closed circuit current flow through the connector. Also, the connector provides a wiping action to improve the electrical connection and will be safer with fewer exposed terminals.
[0009] In an exemplary embodiment of the invention, an electrical connector assembly incorporates a connector with a switch mechanism and is designed to electrically and mechanically connect and disconnect a mating electrical device while maintaining a closed circuit current flow through the connector. The mating electrical device includes a plurality of conductive contacts. The electrical connector includes an insulating housing with at least a pair of input and output terminals from one circuit mounted on the housing. The terminals include contact portions for engaging the contacts of the mating electrical device.
[0010] The switch mechanism is movably mounted on the housing for movement between a connecting position and a disconnecting position. The switch mechanism includes a latch member and at least one switch terminal. In the connecting position, the latch member is inter-engaged with a latch on the mating electrical device with the switch terminal out of engagement with the input and output terminal. In the disconnecting position, the latch member is disengageable from the latch on the mating electrical device so that the device can be removed from the assembly with the switch terminal in engagement with the input and output terminals to maintain a circuit through the connector when the mating electrical device is removed.
[0011] According to one aspect of the invention, the switch mechanism comprises a rotating shaft mounted on the housing. The switch terminal is disposed at an outer periphery of the shaft. The shaft is elongated and is rotatable about its longitudinal axis. The input and output terminals are spaced longitudinally along the shaft. The switch terminal extends longitudinally for shorting the input and output terminals in the disconnecting position of the shaft.
[0012] According to another aspect of the invention, the mating electrical device includes an actuator for moving the switch mechanism between its connecting and disconnecting positions. The actuator includes the latch for inter-engagement with the latch member on the movable switch mechanism. In the exemplary embodiment, the actuator comprises a lever pivotally mounted on the mating electrical device on an axis coincident with the axis of rotation of the shaft that forms the switch mechanism.
[0013] According to a further aspect of the invention, the connector housing and the mating electrical device have mounting faces mountable on a support structure in a coplanar relationship. The mating electrical device is mated onto the housing in a mating direction generally perpendicular to their mounting faces. A plurality of guide projections on the connector housing extend in the mating direction for positioning in a corresponding plurality of guide apertures in the mating electrical device.
[0014] Other features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The features of this invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which:
[0016] FIG. 1 is a perspective view of an electrical connector assembly including a connector and a mating electrical device, with the connector and the device in a disconnecting position;
[0017] FIG. 2 is a side elevation view of the assembly of FIG. 1 ;
[0018] FIG. 3 is a view similar to that of FIG. 2 , but with the device connected to the connector and with the actuating lever on the device in its disconnecting position;
[0019] FIG. 4 is a perspective view of the assembly with the actuating lever on the device pivoted to its connecting position;
[0020] FIG. 5 is a view similar to that of FIG. 3 , with the actuating lever on the device pivoted to its connecting position;
[0021] FIG. 6 is a fragmented, partially cut-away perspective view of the assembly, with the connector housing removed to show the switch shaft, and with the housing of the electrical device removed to show the interconnection of the contacts and the terminals of the assembly in the disconnecting position;
[0022] FIG. 7 is a perspective view of the switch shaft, with one of the switch terminals removed from the shaft;
[0023] FIG. 8 shows an end elevation view of the switch shaft in conjunction with one of the connector terminals, and with the shaft in its disconnecting position from the electrical device;
[0024] FIG. 9 is a view similar to that of FIG. 8 , with the switch shaft in its connecting position when the connector is connected to the electrical device;
[0025] FIG. 10 is a perspective view of an alternate embodiment with a sliding switch actuator in its disconnecting position from the electrical device;
[0026] FIG. 11 shows an end elevation view of the switch shaft of the alternative embodiment in conjunction with one of the connector terminals, and with the shaft in its disconnecting position from the electrical device;
[0027] FIG. 12 shows an end elevation view of the switch shaft in the alternative embodiment in conjunction with one of the connector terminals, and with the shaft in its connecting position from the electrical device;
[0028] FIG. 13 shows a perspective view of the sliding actuator of the alternate embodiment;
[0029] FIG. 14 shows a perspective view of the sliding switch shaft of the alternate embodiment;
[0030] FIG. 15 is a perspective cross sectional view of the alternate embodiment similar to FIG. 10 with a sliding switch actuator in its disconnecting position from the electrical device; and
[0031] FIG. 16 is a perspective cross sectional view of the alternative embodiment view with the sliding switch actuator in its connecting position when the connector is connected to the electrical device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Referring to the drawings in greater detail, and first to FIGS. 1 and 2 , the invention is incorporated in an electrical connector assembly, generally designated 10 , which includes an electrical connector, generally designated 12 , and a mating electrical device, generally designated 14 . Although the invention has a variety of applications, the mating electrical device 14 is an electrical meter in the exemplary embodiment. An electrical current is supplied from a source into and out of the meter 14 through the connector 12 and through a current transformer. If the transformer secondary circuit is open while a load is connected to the transformer primary circuit, very high voltage spikes (kilovolts) induced over the open secondary circuit are likely to impair human safety and/or transformer isolation. To prevent this risk it is essential that a continuous closed electrical circuit be maintained even when the meter is removed.
[0033] The meter, according to this invention, can be very easily and safely mated and unmated with the connector in the direction of double-headed arrow “A.” As will be seen hereinafter, when the meter is mated with the connector, an electrical circuit flows through the connector into and out of the meter. When the meter is unmated from the connector, the current continues to flow through the connector with the help from a shorting circuit created by a shorting terminal. The connector housing 30 and the mating electrical device 14 have mounting faces 30 a , 16 a that are mountable on a support structure in a coplanar relationship. The mating electrical device is mateable onto the housing in a direction generally perpendicular to their mounting faces.
[0034] Still referring to FIGS. 1 and 2 , the electrical device 14 includes a non-conductive housing 16 having a generally planar rear mounting face 16 a and a bottom face 16 b . A pair of guide bosses 18 project from the bottom face 16 b . The guide bosses 18 have through-holes 18 a that extend in the mating direction “A.” As best seen in FIG. 1 , a row of blade contacts 20 made from a conductive material are exposed across the bottom of the housing 16 . An actuator in the form of an actuating lever, generally designated 22 , is pivotally mounted at the bottom of the housing 16 . The lever has a pair of pivot arms 22 a that is pivotally mounted by means of a pair of pivot bosses 22 b inside a pair of pivot flanges 24 that project forwardly of the housing 16 at opposite ends of the row of blade contacts 20 . A somewhat elongated latch projection or boss 26 projects inwardly at the distal end of each pivot arm 22 a . Pivot bosses 22 b project outwardly at the distal end of each pivot arm 22 a . A pair of locks or latch projections 26 is located generally on the pivot axis. The pivot axis of the actuator lever 22 , as defined by the pivot bosses 22 b , is coincidental with the axis 42 of rotation of the switch shaft 40 described below.
[0035] FIG. 3 shows the electrical device 14 moved into full mating condition with the connector 12 . Once the device is mated with the connector, the actuating lever 22 on the meter can be pivoted in the direction of arrow “B” until the lever reaches a connecting position as shown in FIGS. 4 and 5 .
[0036] Referring to FIG. 6 in conjunction with FIGS. 1 and 5 , the connector 12 includes a non-conductive housing 30 ( FIGS. 1 and 5 ) that mounts a plurality of input and output terminals 32 ( FIG. 6 ). The housing 30 has a pair of guide projections 34 as best seen in FIGS. 1 and 5 . The guide projections 34 are received within the guide holes 18 a ( FIG. 1 ) of the guide bosses 18 at the bottom of the housing 16 of the meter 14 as can be seen clearly in FIG. 4 . The terminals 32 are elongated and include terminating portions 32 a ( FIG. 6 ) at one end for termination to a plurality of electrical wires 36 . The terminals have contact portions 32 b at the opposite ends thereof for receiving the blade contacts 20 from the device 14 . The contact portions 32 b are spring-loaded and are bifurcated for receiving the blade contacts and clamping the blade contacts under good contacting forces.
[0037] It should be understood that electrical device 14 can take a variety of configurations or characteristics. In the exemplary embodiment, for instance, the electrical device 14 is a three-phase meter requiring four inputs and four outputs. One pair of input and output terminals is used for each phase with the remaining pair used for a neutral circuit. In other words, it can be seen that there are eight electrical wires 36 leading to eight terminals 32 in the connector 12 , with the eight terminals being engageable with eight blade contacts 20 of the meter 14 .
[0038] When the meter 14 is mated with the connector 12 in the connecting position, alternating ones of the electrical wires/terminals/blade contacts would be inputs from a power source or load, while the other alternating electrical wires/terminals/blade contacts would be outputs of the system, resulting in four pairs of inputs and outputs. Each current circuit is then closed by a current measuring device (not shown) located inside the meter housing. When the meter 14 is to be unmated from the connector 12 , short circuits must first be provided between the inputs and the outputs of each pair in order to prevent each current circuit from being opened. Therefore, a switch mechanism in the form of a rotatable switch shaft, generally designated 40 ( FIG. 6 ), is rotatably mounted within the housing 30 of the connector 12 .
[0039] In an alternative embodiment, the switch mechanism takes the form of a sliding actuator generally designated 62 ( FIGS. 10 , 13 , 15 , and 16 ) that is moved within the housing 30 of the connector 12 . In either embodiment the switch mechanism can include portions of the housing ( 30 ).
[0040] More particularly, referring to FIG. 7 in conjunction with FIG. 6 , the switch shaft 40 is elongated and is rotatable about its longitudinal axis indicated at 42 . Four switch terminals, generally designated 44 , are mounted on the switch shaft at spaced intervals longitudinally therealong. As seen by the removed switch terminal 44 in FIG. 7 , each switch terminal includes a blade-like body portion 44 a that is press-fit into a respective slot 46 in the switch shaft 40 in the direction of arrow “C.” Each switch terminal includes a pair of contact portions 44 b for engaging a pair of the input and output terminals 32 related to the same circuit. In other words, with each adjacent input and output electrical wire 36 and their respective input and output terminals 32 , one switch terminal 44 is provided with two contact portions 44 b for shorting out that respective pair of input and output wires/terminals, as will be seen hereinafter.
[0041] Still referring to FIGS. 6 and 7 , the switch shaft 40 may be fabricated of a non-conductive material such as plastic or the like, and each opposite end of the shaft is provided with a locking member or latch slot 48 that is somewhat elongated for receiving one of the latch projections 26 ( FIG. 1 ) inside one of the pivot arms 22 a of the actuating lever 22 . When the elongated latch projections 26 on the lever 22 are inserted into the elongated latch slots 48 of the switch shaft 40 , a driving connection is created between the lever and the switch shaft for rotating the shaft in response to pivoting the lever. As best seen in FIG. 7 , a pair of locking bosses 50 a and 50 b project radially from the switch shaft at each opposite end thereof. Referring back to FIG. 2 , it can be seen that the housing of the connector 12 is provided with a locking recess 52 for receiving either one of the locking bosses 50 a or 50 b.
[0042] In an alternate embodiment, the switch shaft 40 is replaced with a sliding shaft 70 that slides in either direction “E” or “F” in FIG. 10 . The switch terminals 74 are mounted at spaced intervals longitudinally along the actuator 60 . The electrical device 14 includes a non-conductive housing 16 having a generally planar rear mounting face 16 a and a bottom face 16 b . A pair of guide bosses 18 project from the bottom face. The guide bosses have through-holes 18 a that extend in the mating direction “A”. An actuator in the form of an actuating lever, generally designated 62 , is slidably mounted at the bottom of the housing 16 . The lever has a pair of sliding arms 62 a that are mounted by means of a pair of sliding bosses 62 b inside an opening 64 b in a pair of flanges 64 that project forwardly of housing 16 at opposite ends. As shown in FIG. 13 , the elongated latch slot 66 is directed inwardly at the distal end of each sliding arm 62 a.
[0043] FIG. 10 shows the electrical device 14 moved into full mating condition with the connector 12 . Once the device is mated with the connector, the actuating lever 62 on the meter can be slid in the direction of arrow “E” until the lever reaches a connecting position.
[0044] Referring to FIG. 10 in conjunction with FIGS. 11 and 12 , the connector 12 includes a non-conductive housing 30 that mounts a plurality of input and output terminals, generally designated 32 . The housing has a pair of guide projections 34 that is received within the guide holes 18 a of the guide bosses 18 at the bottom of the housing 16 of the meter 14 , as can be seen clearly in FIG. 10 . The terminals 32 are elongated and include the terminating portions 32 a at one end for termination to a plurality of electrical wires 36 . The terminals have contact portions 32 b at the opposite ends thereof for receiving blade contacts from the device 14 . The contact portions 32 b are spring-loaded and bifurcated for receiving the blade contacts and clamping the blade contacts under good contacting forces.
[0045] Referring to FIG. 14 in conjunction with FIGS. 11 , 12 , and 14 , the switch shaft 70 is elongated and is slidable within the housing 16 . Four switch terminals, generally designated 74 ( FIGS. 11 and 12 ), are mounted on the switch shaft at spaced intervals longitudinally therealong. Each switch terminal includes a blade-like body portion 74 a that is press-fit into a respective slot 76 in the switch shaft 70 . Each switch terminal includes a pair of contact portions 74 b for engaging a pair of the respective input and output terminals 32 . In other words, with each adjacent input and output electrical wire 36 and their respective input and output terminals 32 , one switch terminal 74 is provided with the two contact portions 74 b for shorting out that respective pair of input and output terminals.
[0046] Referring to FIGS. 13 , 14 , 15 , and 16 , the switch shaft 70 may be fabricated of a non-conductive material such as plastic or the like, and each opposite end of the shaft is provided with a latch projection 78 that is somewhat elongated for being received in one of the latch slots 66 inside one of the sliding arms 62 a of actuating lever 62 . When the elongated latch slots 66 on the lever 22 are inserted into the elongated latch projections 78 of the switch shaft 70 , a driving connection is created between the lever and the switch shaft for sliding the shaft in response to sliding of the lever. As seen in FIGS. 15 and 16 , a pair of locks or locking bosses 68 project outwardly from the actuator lever 62 at each opposite end thereof FIG. 15 shows the electrical device 14 and the connector 12 when they are first moved together but prior to their being locked together. This corresponds to FIG. 11 where the switch terminals 74 are in the shorting position with the input output terminals 32 . In FIG. 16 the actuator lever 62 has been moved in the direction “E” that is where the electrical device 14 and the connector 12 are locked together. In this position, the locking boss 68 slides under the locking member or the locking shoulder 16 d . This corresponds to FIG. 12 where the switch terminals 74 are slid out of their shorting position with the input output terminals 32 .
[0047] The operation of the electrical connector assembly 10 now will be described, particularly in relation to the function of the switch shaft 40 as seen in FIGS. 8 and 9 and the sliding actuator 62 in FIGS. 10-16 . In particular, after proper calibration, the meter 14 is mated with the connector 12 as described above in relation to the sequential depictions in FIGS. 2 and 3 . It should be noted that the connector, in the disconnected position as seen in FIGS. 1 and 2 , have fewer areas of exposed terminals that can be contacted by other conductive parts or by an operator's hands. This makes the connector safer than the prior art connectors.
[0048] For mating to occur, the actuating lever 22 , 62 must be in the position shown on FIGS. 2 and 10 respectively with respect to the meter housing 16 . At the electrical connectors side, the switch shaft 40 is in a shorting position wherein the contact portions 40 b of the switch terminals 44 are establishing short circuits between the input and output terminals 32 and their respective input and output electrical wires 36 , and wherein the latch slots 48 at opposite ends of the shaft open upwardly or the latch projections 78 open downwardly (see FIGS. 15 , 16 ). It can be seen that locking bosses 50 a at opposite ends of the shaft are locked within the locking recesses 52 to hold the shaft in this position.
[0049] The meter 14 is moved into mating position with the connector in the direction of arrow “A” whereby the blade contacts 20 of the meter 14 are pushed into the bifurcated contact portions 32 b of terminals 32 as seen in FIG. 6 . As seen in FIG. 3 , the latch projections 26 ( FIG. 1 ) on the lever 22 will move into the latch slots 48 or, as seen in FIGS. 15 and 16 , the latch projection 78 will move into the latch slots 66 in the sliding lever 62 to establish a driving connection between the actuation lever 22 , 62 and the shaft 40 , 70 . Also the guide projections 34 are received within the guide holes 18 a , which helps to prevent movement between the electrical device 14 and the connector 12 in either direction “E” or “F”. In this pre-existing position, the switch shaft 40 , 70 , as seen in FIGS. 8 and 11 , the contact portions 40 b , 70 b of the switch terminals 44 , 74 are still establishing short circuits between the input and output terminals 32 and their respective input and output electrical wires 36 . However, additional current circuits provided by the meter in parallel to short circuits will now exist, making it possible to remove the short circuits with out any risk of an open circuit.
[0050] The actuating lever 22 then is pivoted in the direction of arrow “B” ( FIG. 3 ) to the position shown in FIGS. 4 and 5 or the actuator lever 62 is slid in the direction of arrow “E”. Pivoting of the lever 22 correspondingly rotates the switch shaft 40 in the direction of arrow “D” as seen in FIG. 9 . Moving the sliding actuator 62 in the direction of arrow “E” slidably moves the switch shaft 70 , as seen in FIG. 12 . This moves the contact portions 44 b , 74 b of the switch terminals 44 , 74 out of shorting engagement with the input and output terminals 32 . The movement of the switch terminals 44 , 74 over the input and output terminals 32 will remove some of any non-conductive material that may build up on either of the contact surfaces between the switch terminals 44 , 74 and the input and output terminals ensuring a better electrical connection.
[0051] With the blade contacts 20 of the meter 14 inserted into the contact portions 32 b of the terminals 32 , circuits now are closed with electrical current flowing into and out of the meter 14 . In the shorting condition of the switch shaft 40 , the locking bosses 50 a are snapped into the locking recesses 52 as seen in FIG. 2 to hold the switch shaft in its shorting position. When the lever rotates the shaft to the position of FIG. 9 , the locking bosses 50 a snap out of the locking recesses 52 and the locking bosses 50 b snap into the locking recesses to hold the shaft and the lever in the connecting position of the meter and the connector.
[0052] Other features that should be noted include the fact that the meter 14 cannot be disconnected from the connector 12 when the rotating lever 22 is in the position of FIGS. 4 and 5 or when the sliding actuator 62 is in the position as seen in FIG. 16 . In other words, the interengagement of the latch projections 26 on the lever within latch the slots 48 on the shaft or of the locking boss 68 of the sliding actuator 62 under the locking shoulder 16 d will provide latch means to help hold the meter and the connector in a mated condition. FIG. 8 represents a disconnecting position of the switch shaft 40 whereby the latch projections 26 can be easily moved out of the latch slots 48 and further whereby the switch terminals 44 engage the input-output terminals 32 . FIGS. 10 and 15 also represent a similar disconnecting position. FIGS. 9 and 12 represent a connecting position of switch shaft 40 , 70 with the meter and connector connected to each other. This locking occurs because the latch projections 26 can not be removed from the latch slots 48 or the locking boss 68 cannot be removed from under locking shoulder 16 d along with the interaction between the guide projections 34 and the guide holes 18 a . In this connecting position the switch terminals 44 , 74 are out of engagement with the input and output terminals 32 .
[0053] As seen in FIGS. 4 and 10 , the housing 30 of the connector 12 has a rear mounting face 30 a that is coplanar with the rear mounting face 16 a of the housing 16 of the meter 14 , whereby the connector assembly 10 can be mounted on a flat or generally planar support surface. To that end, as seen in FIG. 5 , the housing of the connector has a mounting flange 30 b projecting out of each opposite side thereof for receiving appropriate fasteners to mount the connector to the support surface. The meter 14 has a mounting flange 16 c for receiving appropriate fasteners to mount the meter to the support structure.
[0054] It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.
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An electrical connector assembly ( 10 ) incorporates a connector ( 12 ) with a switch and is designed to electrically and mechanically connect and disconnect to a mating electrical device ( 14 ) while maintaining a closed circuit continuously through the connector. The mating electrical device includes a plurality of conductive contacts ( 20 ). The electrical connector includes an insulating housing ( 30 ) with at least a pair of input and output terminals ( 32 ) mounted on the housing. The terminals include contact portions ( 32 b ) for engaging the contacts of the mating electrical device. A switch mechanism ( 40; 60 ) is movably mounted on the housing for movement between a connecting position and a disconnecting position. The switch mechanism includes a latch member ( 48; 17 ) and at least one switch terminal ( 44 ). In the connecting position, the latch member is interengaged with a latch ( 26; 62 ) on the mating electrical device with the switch terminal out of engagement with the input and output terminal. In the disconnecting position, the latch member ( 48, 17 ) is disengageable from the latch ( 26, 62 ) on the mating electrical device so that the device can be removed from the assembly with the switch terminal ( 44 ) in engagement with the input and output terminals ( 32 ) to maintain a closed circuit through the connector ( 12 ) when the mating electrical device ( 14 ) is removed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a power amplifier linearization method and apparatus, and more particularly, to a method and apparatus for effectively linearizing a power amplifier having a plurality of distortion generating sources.
[0003] 2. Description of the Related Art
[0004] Recently, a power amplifier in a mobile communication system has been required to amplify a signal with high efficiency and high linear characteristics. In addition, a next generation mobile communication system uses a complicated modulation scheme in order to transmit a large amount of data to the user in a short time.
[0005] Accordingly, the peak-to-average power ratio (PAPR) of the signal increases. Generally, in order to provide linear amplification, a power amplifier operates at a back off point equal to or greater than the peak-to-average power ratio of a signal.
[0006] However, at this point, the power amplifier exhibits a considerably low efficiency characteristic. This is because the stable operation of a transmitter is not ensured due to an increase of the heating value of the transmitter. Therefore, an additional cooling system is required.
[0007] In order to improve the efficiency of a power amplifier at a back-off point, a Doherty amplifier has recently received wide attention.
[0008] FIG. 1 is a block diagram illustrating the configuration of a conventional Doherty power amplifier.
[0009] Referring to FIG. 1 , a Doherty amplifier 100 includes: a power divider 102 ; an input phase compensation unit 104 ; a carrier amplifier 106 ; a peaking amplifier 108 ; offset lines 110 and 112 configured to generate a high peaking output impedance when the peaking amplifier does not operate, and thus to allow the occurrence of a suitable load modulation phenomenon of the carrier amplifier; and a combiner 114 .
[0010] The power divider 102 divides and outputs an input signal to the carrier amplifier 106 and the peaking amplifier 108 . The carrier amplifier 106 uses relatively high input Direct Current (hereinafter, referred to as “DC”) bias. The peaking amplifier 108 uses relatively low input DC bias. Each of the carrier amplifier 106 and peaking amplifier 108 amplifies the input signal according to a preset amplification gain and outputs the amplified input signal to the combiner 114 . The combiner 114 combines the output signal of the carrier amplifier 110 and the output signal of the peaking amplifier 115 . The input phase compensation unit 104 compensates for a phase difference which is caused by the offset lines 110 and 112 and the combiner 114 .
[0011] FIG. 2 a is a graph illustrating the fundamental current components of the carrier amplifier 106 and peaking amplifier 108 in ideal and real cases.
[0012] Referring to FIG. 2 a, in the ideal case, it can be understood that the fundamental current components of the carrier amplifier 106 and peaking amplifier 108 have constant slopes according to the increase of an input voltage. However, in the real case, the carrier amplifier 106 and peaking amplifier 108 may be configured with a field effect transistor (FET), a high electron mobility transistor (HEMT), a bipolar junction transistor (BJT) or the like, which are semiconductor elements, wherein the current components of the FET, HEMT, and BJT increase in a square fashion or exponential fashion. When the current feature is applied to the peaking amplifier 108 , the fundamental current components of the peaking amplifier 108 are the same as the real current feature in FIG. 2 a.
[0013] FIG. 2 b is a graph illustrating fundamental voltage components of the carrier amplifier 106 and peaking amplifier 108 in ideal and real cases.
[0014] Referring to FIG. 2 b, it can be identified that the fundamental voltage components of the carrier amplifier 106 and peaking amplifier 108 in the real case are the same as in the ideal case. The fundamental voltage components are determined by the fundamental current components, the output matching impedance of the carrier amplifier 106 and the output matching impedance of the peaking amplifier 108 , wherein the output matching impedances are as Equation 1 below:
[0000]
Z
C
=
{
Z
T
2
Z
L
0
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V
in
<
0.5
·
V
in
,
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Z
T
2
Z
L
·
[
1
+
I
P
I
C
′
]
0.5
·
V
in
,
Max
≤
V
in
≤
V
in
,
Max
Z
P
=
{
∞
0
≤
V
in
<
0.5
·
V
in
,
Max
Z
L
·
[
1
+
I
C
′
I
P
]
0.5
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V
in
,
Max
≤
V
in
≤
V
in
,
Max
I
C
′
=
I
C
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Z
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Z
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.
(
1
)
[0015] In Equation 1, V in represents an input voltage, Z C represents the output matching impedance of the carrier amplifier 106 , Z P represents the output matching impedance of the peaking amplifier 108 , Z L represents a matching impedance at a point where the power of the carrier amplifier 106 and the power of the peaking amplifier 108 are combined, and Z T represents the characteristic impedance of the quarter wave transmission line between the carrier amplifier 106 and the peaking amplifier 108 in the combiner 114 . Generally, there is a relation of Z L =Z T /2. In addition, I C represents input current of the carrier amplifier 106 , and I P represents input current of the peaking amplifier 108 .
[0016] Referring to Equation 1, it can be identified that, although the fundamental current components of the peaking amplifier 108 in the real case are less than those in the ideal case, the fundamental voltage components in the real case are the same as those in the ideal case, as shown in FIG. 2 b, because the amplitudes of the Z C and Z P increase.
[0017] FIG. 3 is a graph illustrating the input/output power of the Doherty amplifier 100 in the ideal and real cases.
[0018] Referring to FIG. 3 , in the ideal case, the Doherty amplifier 100 has a linear relation between the input and output power. However, in the real case, since the fundamental current components of the peaking amplifier 108 decrease as shown in FIG. 2 a, the Doherty amplifier 100 has an output power lower that in the ideal case, so that the output power of the Doherty amplifier 100 including the peaking amplifier 108 cannot have a linear relation, and thus has an undesired distortion characteristic.
[0019] FIG. 4 is a graph illustrating a memory effect in a real Doherty amplifier.
[0020] The memory effect means that the distortion component of an amplifier is influenced by not only the current input signal, but also by previous input signals. The memory effect in an amplifier can be identified through a non-linearity measurement using a two-tone signal. When applying a two-tone signal to an amplifier, and observing the fundamental wave components of the amplifier and a third-order distortion signal with respect to the same output power, it is possible to identify third-order distortion signals having different amplitudes and different phases depending on the bandwidths of two-tone signals. Through such a method, it is possible to measure a memory effect. Generally, a large memory effect occurs in an intermediate output power, while a large memory effect is not observed in a low output power because a distortion component caused by the amplifier itself is small in the low output power. In addition, in a high output power, since the distortion component caused by the power amplifier itself is large, it is impossible to recognize a memory effect.
[0021] Referring to FIG. 4 , it can be understood that the Doherty amplifier shows a memory effect characteristic different from that of a general amplifier. This is because the Doherty amplifier is configured with a carrier amplifier and a peaking amplifier, and the carrier amplifier and peaking amplifier operate differently from each other and thus show mutually different distortion characteristics.
[0022] As described above, not only the Doherty amplifier but also the other power amplifiers generate a non-linear component to distort an output signal, thereby degrading the signal quality. Therefore, in order to satisfy the linearity required in communication systems, it is necessary to develop a separate linearization technique. Among linearization techniques, a digital predistorter processes signals in a digital band, and thus has an excellent economical efficiency and expansion possibility, as compared with the other linearization techniques.
[0023] FIG. 5 is a block diagram illustrating the configuration of a Doherty amplification system including a digital predistorter, to which the present invention is applied.
[0024] Referring to FIG. 5 , a Doherty amplification system includes a Doherty amplifier 100 , a digital predistorter 200 , a digital predistorter controller 300 , a digital-to-analog converter (DAC) 400 , an analog-to-digital converter (ADC) 500 , an up converter 600 , and a down converter 700 .
[0025] The operation of the Doherty amplification system illustrated in FIG. 5 is as follows.
[0026] At an initial operation, the digital predistorter 200 enters an initial mode.
[0027] The initial mode means an operation mode for measuring the non-linear characteristic and memory effect of the Doherty amplifier 100 . In the initial mode, it is possible to use either a specified signal which makes it possible to identify the characteristics of the Doherty amplifier 100 in the entire operation region thereof, or a signal used in a real communication system during a predetermined time period. Signals used in the initial mode will be inclusively designated as a test signal.
[0028] First, a digital signal, which is a test signal, is inputted to the digital predistorter 200 and the digital predistorter controller 300 . However, in the initial mode, the signal inputted to the digital predistorter 200 passes through the digital predistorter 200 without any predistortion. The signal which has passed through the digital predistorter 200 is converted into an analog signal through the DAC 400 . The analog signal which has passed through the DAC 400 is inputted to the up converter 600 and is thus converted into a high-frequency analog signal. The high-frequency analog signal is inputted to the Doherty amplifier 100 and is amplified therein. The analog signal which has been amplified by the Doherty amplifier 100 is distorted and thus has a non-linear characteristic and a memory effect. Most of the signal which has been amplified by the Doherty amplifier 100 propagates over the air, and a part thereof is converted into a low-frequency signal by the down converter 700 . The low-frequency analog signal which has passed through the down converter 700 is converted into a digital signal through the ADC 500 . The digital signal which has passed through the ADC 500 is inputted to the digital predistorter controller 300 .
[0029] The digital predistorter controller 300 compares the test signal with a signal distorted by the Doherty amplifier 100 , and perceives a non-linear characteristic and a memory effect which are caused by the Doherty amplifier 100 . Using the perceived information, the digital predistorter controller 300 calculates a configuration value of the digital predistorter 200 in order to compensate for the non-linear characteristic and memory effect caused by the Doherty amplifier 100 .
[0030] For reference, for convenience of description of the present invention, the non-linear characteristic represents an amplitude modulation-to-amplitude modulation (AM-to-AM) characteristic in which the amplitude of an output signal varies non-linearly depending on the amplitude of an input signal, and an amplitude modulation-to-phase modulation (AM-to-PM) characteristic in which the phase of an output signal varies non-linearly depending on the amplitude of an input signal. The digital predistorter 200 is configured with a look-up table (LUT), a polynomial, or the like.
[0031] Therefore, the digital predistorter controller 300 provides an LUT configuration value or a coefficient of a polynomial of the digital predistorter 200 .
[0032] FIG. 6 is a block diagram illustrating the inner configuration of the conventional digital predistorter 200 .
[0033] Referring to FIG. 6 , the conventional digital predistorter is configured with an amplifier compensator 210 .
[0034] The amplifier compensator 210 compensates for only the non-linear characteristic of the Doherty amplifier 100 , or compensates for both non-linear characteristic and memory effect. In addition, a signal which has passed through the amplifier compensator 210 is inputted to the DAC 400 shown in FIG. 5 .
[0035] The amplifier compensator 210 may be configured with a polynomial, may be configured with an LUT, and may be configured with both polynomial and LUT. In addition, Volterra Series, a reduction model of Volterra Series, a Wiener model, an expansion model of the Wiener model, a Hammerstein model, an expansion model of the Hammerstein, etc. may be applied to the amplifier compensator 210 .
[0036] Generally, if an amplifier has a plurality of distortion generating sources to be linearized, and the respective distortion generating sources generate the same non-linear characteristic and memory effect, the non-linear characteristic and memory effect can be sufficiently compensated through the amplifier compensator 210 shown in FIG. 6 .
[0037] However, in the case of an amplifier, such as a Doherty amplifier, which includes distortion generating sources generating mutually different non-linear characteristics and memory effects, there is a limitation in a degree of linearization improvement when linearization according to the conventional linearization manner is performed as in the amplifier compensator 210 .
SUMMARY OF THE INVENTION
[0038] Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a method and apparatus for effectively linearizing an amplifier which has a plurality of distortion generating sources.
[0039] In order to achieve the above object, according to one aspect of the present invention, there is provided an apparatus for effectively linearizing an amplifier having a plurality of distortion generating sources, the apparatus comprising: a plurality of digital predistortion compensators configured to compensate for the distortion characteristics of the respective distortion generating sources; a signal division unit configured to select one route of the plurality of digital predistorters according to the amplitude of an input signal; and a signal combination unit configured to combine predistorted signals which have passed through a plurality of digital predistorters, wherein the signal division unit selects and determines the route depending on the non-linear characteristic and memory effect of a distorted signal.
[0040] According to another aspect of the present invention, there is provided a method for effectively linearizing an amplifier having a plurality of distortion generating sources, the method comprising the steps of: Generating predistortion signals through a plurality of digital predistortion compensation steps for compensating for the distortion characteristics of the respective distortion generating sources; selecting one route of a plurality of digital predistorters according to the amplitude of an input signal; and combining predistorted signals which have passed through a plurality of digital predistorter, wherein, in a signal division step, the route is selected and determined depending on the non-linear characteristic and memory effect of a distorted signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description taken in conjunction with the drawings, in which:
[0042] FIG. 1 is a block diagram illustrating the configuration of a conventional Doherty power amplifier;
[0043] FIG. 2 a is a graph illustrating the fundamental current components of a carrier amplifier and a peaking amplifier in ideal and real cases;
[0044] FIG. 2 b is a graph illustrating the fundamental voltage components of the carrier amplifier and peaking amplifier in ideal and real cases;
[0045] FIG. 3 is a graph illustrating the input/output power of a Doherty amplifier in the ideal and real cases;
[0046] FIG. 4 is a graph illustrating a memory effect in a real Doherty amplifier;
[0047] FIG. 5 is a block diagram illustrating the configuration of a Doherty amplification system including a digital predistorter, to which the present invention is applied;
[0048] FIG. 6 is a block diagram illustrating the inner configuration of a conventional digital predistorter;
[0049] FIG. 7 a is a block diagram illustrating the inner configuration of a digital predistorter according to a first embodiment of the present invention;
[0050] FIG. 7 b is a block diagram illustrating the inner configuration of a digital predistorter according to a second embodiment of the present invention;
[0051] FIG. 7 c is a block diagram illustrating the inner configuration of a digital predistorter according to a third embodiment of the present invention;
[0052] FIG. 8 a is a graph illustrating an AM/AM characteristic modeling according to the present invention;
[0053] FIG. 8 b is a graph illustrating an AM/PM characteristic modeling according to the present invention;
[0054] FIG. 9 a is a graph illustrating a spectrum after power amplifier linearization according to the present invention;
[0055] FIG. 9 b is a graph illustrating an AM/AM characteristic after power amplifier linearization according to the present invention; and
[0056] FIG. 9 c is a graph illustrating an AM/PM characteristic after power amplifier linearization according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0057] Reference will now be made in greater detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.
[0058] Before a detailed description of the present invention, it should be noted that a digital predistorter according to the present invention can be applied to compensate for mutually different non-linear characteristics and memory effects which are generated by a plurality of distortion generating sources during amplification through a plurality of amplifiers, wherein the following description will be given with a Doherty amplifier as an example.
[0059] FIG. 7 a is a block diagram illustrating the inner configuration of a digital predistorter according to a first embodiment of the present invention.
[0060] Referring to FIG. 7 a, the digital predistorter includes a signal division unit 220 , a first amplifier compensation unit 222 , a second amplifier compensation unit 224 , and a signal combination unit 226 .
[0061] The signal division unit 220 compares the amplitude of an input signal with a predetermined threshold value, outputs the input signal to the first amplifier compensation unit 222 or the second amplifier compensation unit 224 . That is to say, in the case where the amplitude of an input signal has a value in a range from 0 to 1, the signal division unit 220 outputs an input signal to the first amplifier compensation unit 222 when the input signal is in a range from 0 to the threshold value, and outputs an input signal to the second amplifier compensation unit 224 when the input signal is in a range from the threshold value to 1. Taking a Doherty amplifier for instance, the first amplifier corresponds to a carrier amplifier, and the second amplifier corresponds to a peaking amplifier. The threshold value is set to be the amplitude of an input signal which corresponds to a time point in which the peaking amplifier starts operating when the peaking amplifier ideally operates.
[0062] The first amplifier compensation unit 222 and the second amplifier compensation unit 224 output inverse distortion signals for compensating for the distortion components of amplifiers using the signal inputted from the signal division unit 220 . In this case, the first amplifier compensation unit 222 and the second amplifier compensation unit 224 are in a state in which each compensation unit 222 and 224 has acquired a compensation value for compensating for not only the non-linear characteristic of a corresponding amplifier but also for an inverse distortion signal to compensate for the memory effect of the corresponding amplifier.
[0063] The first amplifier compensation unit 222 and the second amplifier compensation unit 224 may be configured with a polynomial, may be configured with an LUT, and may be configured with both polynomial and LUT. In addition, Volterra Series, a reduction model of Volterra Series, a Wiener model, an expansion model of the Wiener model, a Hammerstein model, an expansion model of the Hammerstein, etc. may be applied to the first amplifier compensation unit 222 and second amplifier compensation unit 224 . In addition, it is obvious to a person skilled in the art to enable all types of compensation units capable of compensating for the non-linear characteristic and memory effect of an amplifier to be employed as the first amplifier compensation unit 222 and second amplifier compensation unit 224 according to the present invention.
[0064] The signal combination unit 226 receives inverse distortion signals outputted from the first amplifier compensation unit 222 and second amplifier compensation unit 224 , and sends an output signal to be used as an input of the DAC 400 shown in FIG. 5 .
[0065] As described above, a compensation unit suitable for a distortion generating source making a large contribution to generation of a distortion signal according to the amplitudes of signals is used in an amplifier having a plurality of distortion generating sources, so that it is possible to effectively compensate for distortion signals generated by the distortion generating sources.
[0066] FIG. 7 b is a block diagram illustrating the inner configuration of a digital predistorter according to a second embodiment of the present invention.
[0067] Referring to FIG. 7 b, the digital predistorter includes a signal division unit 220 , a first amplifier compensation unit 222 , a second amplifier compensation unit 224 , a signal combination unit 226 , and an amplifier compensation unit 228 .
[0068] The signal division unit 220 , first amplifier compensation unit 222 , second amplifier compensation unit 224 , and signal combination unit 226 perform the same operations as those in FIG. 7 a, so a detailed description thereof will be omitted.
[0069] The amplifier compensation unit 228 receives an inverse distortion signal, which has been created through the first amplifier compensation unit 222 and second amplifier compensation unit 224 and has been outputted from the signal combination unit 226 , and then outputs an additional amplifier compensation signal.
[0070] The amplifier compensation unit 228 additionally compensates for interference between distortion signals generated by a plurality of distortion generating sources, or for discontinuity between inverse distortion signals created depending on a threshold value.
[0071] Similar to the case of first amplifier compensation unit 222 and second amplifier compensation unit 224 , it is obvious to a person skilled in the art to enable all types of compensation units capable of compensating for the non-linear characteristic and memory effect of an amplifier to be employed as the amplifier compensation unit 228 according to the present invention.
[0072] In addition, while the amplifier compensation unit 228 may be positioned after the signal combination unit 226 , the amplifier compensation unit 228 may be positioned before the signal division unit 220 , wherein the function of the amplifier compensation unit 228 is the same as that described above. Such a configuration is shown in FIG. 7 c.
[0073] FIG. 8 a is a graph illustrating an AM/AM characteristic modeling according to the present invention. FIG. 8 b is a graph illustrating an AM/PM characteristic modeling according to the present invention.
[0074] Referring to FIGS. 8 a and 8 b, it can be understood that a model according to the present invention shows a superior performance characteristic to the conventional model.
[0075] FIG. 9 a is a graph illustrating a spectrum after power amplifier linearization according to the present invention. FIG. 9 b is a graph illustrating an AM/AM characteristic after power amplifier linearization according to the present invention. FIG. 9 c is a graph illustrating an AM/PM characteristic after power amplifier linearization according to the present invention.
[0076] Referring to FIGS. 9 a to 9 c, it can be understood that the linearization according to the present invention shows a superior performance characteristic in terms of the output of an amplifier to the conventional linearization.
[0077] As described above, it can be understood that a plurality of compensation units are used to compensate for the distortion characteristic of an amplifier which has a plurality of distortion generating sources, thereby obtaining a superior modeling characteristic, and thus outputting a superior linearization result.
[0078] As is apparent from the above description, the present invention provides a linearization apparatus, which includes a plurality of digital predistorters to compensate for the respective distortion characteristics generated by a plurality of distortion generating sources in order to compensate for mutually different non-linear characteristics and memory effects generated by the plurality of distortion generating sources, thereby making it possible to effectively compensate for the distortion signals generated by the plurality of distortion generating sources.
[0079] Although preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and the spirit of the invention as disclosed in the accompanying claims.
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Disclosed is a method and apparatus for linearizing a power amplifier using a digital signal process (DSP), and particularly, is a method and apparatus for effectively linearizing an amplifier which has a plurality of distortion generating sources. To this end, there is a plurality of compensation methods and compensation units which can generate inverse distortion signals corresponding to the distortion components outputted by the plurality of distortion generating sources, thereby making it possible to provide superior linearity.
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RELATED U.S. APPLICATIONS
This application incorporates herein by reference, and claims priority to, the commonly-owned co-pending provisional patent application U.S. Ser. No. 60/467,794, entitled “MULTI-MODE CONFERENCE CALL SETUP AND MANAGEMENT AND DATA BROWSING USER INTERFACE TECHNIQUE (‘MULLET DATEBOOK’) AND DYNAMIC SIZING USER INTERFACE TECHNIQUE FOR DATA DISPLAY AND TEXT-KEY CUSTOMIZATION FOR AUDIO MENU SELECTION,” filed May 1, 2003, and to the commonly-owned U.S. Pat. No. 6,516,202 B1, entitled “MOBILE COMPUTER SYSTEM DESIGNED FOR WIRELESS COMMUNICATION EXPANSION,” issued on Feb. 4, 2003, and assigned to the assignee of the present invention.
FIELD OF THE INVENTION
The present invention relates to the field of user interaction with data displayed in handheld portable electronic devices.
BACKGROUND OF THE INVENTION
As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. A relatively recent category of computer system is the portable or handheld computer device. A handheld computer system is a computer that is small enough to be held in the hand. As a result, these devices are readily carried about in a briefcase or purse, and some handheld devices are compact enough to fit into a person's pocket. By virtue of their size, handheld computer systems are also lightweight and so are exceptionally portable and convenient.
Further development of handheld devices has enabled their use for more and more tasks. For example, portable, and even wireless, access to computer networks is now readily available with suitably configured devices. The portability and convenience of handheld devices has enabled the even more exciting possibilities encompassed by the combination of the capabilities of handheld devices with the communication convenience of wireless telephones, e.g. cellular phones.
As more and more of these devices are carried in everyday activities, the demand for more and more capability from these versatile machines also grows. The demanding environment of modern working life sometimes requires multi-tasking by the individual, requiring a careful scheduling of daily events as well as the events of the busy workplace, often using the assistance of planning or scheduling aids or planners. Often these weekly and monthly planners need to be accessed while the user is on the go.
As convenient as handheld computing devices are, users demand ease of use. Often a simple task such as quickly checking the time of an upcoming event, scheduling a meeting, or checking a meeting attendance list or agenda topic requires two hands and a convenient lap or desk. This is often caused by the existence of more relevant data than is displayed in the existing display view. It would be desirable to simplify the graphical user interface experience for a user and present helpful daily information in an intuitive manner.
SUMMARY OF THE INVENTION
Accordingly, embodiments of the present invention are directed to a method and system for viewing daily information, e.g., messages from others, to-do data and organized calendar data in a database. The method can be implemented in a portable computing device, such as a handheld computing device, and user input to navigate through the database can be accepted by alpha-numeric input, touch-screen display tactile input or by five-way navigation button, for example.
Embodiments of the present invention relate to methods and devices for displaying information in a handheld device, comprising displaying information in a dynamically sizable cell in the display of the handheld device, wherein the cell comprises a portion of the display and the size of the cell is adjusted in response to the amount of information it contains. Embodiments of the present invention are enabled to display the information in a plurality of dynamically sizable on-screen displayed cells or windows which display different categories of information. Embodiments are also enabled to adjust cell size in response to the size of the other cells in the display and/or based on the data to be displayed and/or user defined cell display options.
Embodiments of the present invention are also presented which are enabled to present windows or cells that include a list of appointments, a list of daily tasks to accomplish and an email window. The combination of cells can be referred to as a “Today View” in some embodiments, and can show information a user needs to know for the ensuing twenty four hours. Embodiments can also display a clock with events, To-Do items, and messages that will impact or are useful to the user over the next twenty four hours.
When Today View displays information, it uses a pointer system that adjusts what is displayed on-screen based on how much information needs to be displayed, and from what application. When ranking information, a focus is to convey scheduling information, such as for appointments or events. The second focus of data to convey is To-Do items, and the last is messaging information. Appointments and events are listed in a cell that can be called an “agenda” cell, a “timed events” cell, or simply an “events” cell. The above ranking is one example only. As discussed, this data is displayed in cells. Appointments and events listed may be created in other parts of the present invention or in other applications, known as “creator” applications.
According to embodiments of the present invention, appointment and to-do cells are dynamically sized. Today View efficiently takes advantage of as much screen display area as possible to convey important daily items. When Agenda has more items from the creator applications than can be displayed individually, it aggregates items based on priority. The overall strategy is to present these aggregation messages as a link to the respective creator view that can always appear in the same, persistent default setting and filtering state.
Messages, being the lowest in priority in some embodiments, can be aggregated and limited to just one display line. In many embodiments, the Today View is enabled to convey a count of messages that have been received and already read and those that have been received and are as yet unread. Embodiments are enabled to launch an email client application, revealing the messages, with a “tapping” on the touch screen or other selection of the message line text.
In some embodiments, the aggregation rule can next apply to tasks to accomplish, or “ToDo” items. If there is enough display area available, time-based ToDo items can be displayed as separate line items with the current day's due items on top of the list. ‘Hidden’ time based ToDo's can be aggregated as “Due Today,” “Past Due,” etc. The user can optionally select not to display the to-do cell and/or the messages cell.
Embodiments of the present invention employ five-way navigation usable in calendar viewing. Some embodiments are enabled to employ a “Tall Screen” display which allows an active input area of the touch screen display to be collapsed to present more display area in a rectangular format. Embodiments are also enabled to orient displayed information to a “landscape” format, where the long axis of the rectangular display is horizontal, or to a “portrait” format, where the long axis is vertical. Embodiments are also enabled to present user-selected background images in each of these display formats.
BRIEF DESCRIPTION OF THE DRAWINGS
The operation and components of this invention are described by reference to the drawings.
FIG. 1A illustrates, in block flow diagram, a computer implemented method for browsing, manipulating and viewing data consistent with embodiments of the present invention.
FIG. 1B illustrates, in block flow diagram, a computer implemented method for dynamically sizing cells in a display consistent with embodiments of the present invention.
FIG. 2A illustrates an embodiment of dynamically sizable cells in a display in accordance with embodiments of the present invention.
FIG. 2B illustrates interrelated sizing of dynamically sizable cells in a display in accordance with embodiments of the present invention.
FIG. 2C illustrates another interrelated sizing of dynamically sizable cells in a display in accordance with embodiments of the present invention.
FIG. 2D illustrates another interrelated sizing of dynamically sizable cells in a display in accordance with embodiments of the present invention.
FIG. 2E illustrates another interrelated sizing of dynamically sizable cells in a display in accordance with embodiments of the present invention.
FIG. 2F illustrates an interrelated sizing of dynamically sizable cells in which cells have no listed information in a display in accordance with embodiments of the present invention.
FIG. 2G illustrates another interrelated sizing of dynamically sizable cells in which cells have no listed information in a display in accordance with embodiments of the present invention.
FIG. 2H illustrates another interrelated sizing of dynamically sizable cells in which cells have no listed information in a display in accordance with embodiments of the present invention.
FIG. 3A illustrates a display options window in accordance with an embodiment of the present invention.
FIGS. 3B , 3 C, 3 D and 3 E illustrate selecting a background image in a display of a handheld computing device in accordance with an embodiment of the present invention.
FIGS. 3F and 3G illustrate creating and editing a timed event in accordance with an embodiment of the present invention.
FIGS. 4A and 4B illustrate a rectangular display in portrait mode with a collapsible active input area in accordance with an embodiment of the present invention.
FIGS. 4C and 4D illustrate a rectangular display in landscape mode with a collapsible active input area in accordance with an embodiment of the present invention.
FIG. 4E illustrates a rectangular display in portrait mode with a background image in accordance with an embodiment of the present invention.
FIG. 5 illustrates sizing a background image in a rectangular display in portrait mode in accordance with an embodiment of the present invention.
FIG. 6 illustrates an exemplary physical embodiment of a portable computer system in accordance with one embodiment of the present invention.
FIG. 7A illustrates an exemplary physical embodiment of a portable computer system in accordance with one embodiment of the present invention.
FIG. 7B illustrates an exemplary physical embodiment of a portable computer system in accordance with another embodiment of the present invention with an extended screen mode.
FIG. 7C illustrates a physical embodiment of a portable computer system in accordance with one embodiment of the present invention with an extended screen mode and a graphical user interface.
FIG. 8 illustrates a physical embodiment of a portable computer system in accordance with one embodiment of the present invention presented in landscape mode.
FIG. 9 illustrates an exemplary portable computer system, optionally enabled as a telephone, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The following descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application; to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
These descriptions of specific embodiments incorporate herein by reference, and claims priority to, the commonly-owned co-pending provisional patent application U.S. Ser. No. 60/467,794, entitled “MULTI-MODE CONFERENCE CALL SETUP AND MANAGEMENT AND DATA BROWSING USER INTERFACE TECHNIQUE (‘MULLET DATEBOOK’) AND DYNAMIC SIZING USER INTERFACE TECHNIQUE FOR DATA DISPLAY AND TEXT-KEY CUSTOMIZATION FOR AUDIO MENU SELECTION,” filed May 1, 2003, and assigned to the assignee of the present invention.
In this discussion of some embodiments of the present invention, the terms, “handheld device,” “cell phone,” “portable electronic device” and “portable computing device” are used more or less interchangeably, as noted previously. In each case, they refer to a class of relatively small, user-portable, computing devices that are capable of performing the functions of portable computing devices and, importantly, accept user input in the form of pressure applied to, for instance, a touch-screen display/input device, through alpha-numeric key input, or through a multi-directional navigation button, etc. Some of the above terms are also used to refer to devices that combine the functions of portable computing devices with those of wireless telephones.
It is noted here that specific names are used herein for many of the features presented in embodiments of the present invention. The names are used in this discussion only for example and illustration. Embodiments can be implemented with different names and can present different languages without limiting the functions and features found in these embodiments.
FIG. 1A illustrates, in block flow diagram form, a computer implemented method for displaying calendar information in a handheld device. There, process 100 begins by displaying information in the display of a handheld device 110 . The information displayed can be any type of information but in this embodiment of the present invention it is envisioned as daily information, e.g., appointment and task information listed in text and graphical format in on-screen cells or windows that are dynamically sizable. Some embodiments are enabled to provide a graphic image as background or “wallpaper.” Other embodiments of the present invention are enabled to provide graphic information in a number of dynamically sizable cells.
Process 100 continues by sizing the dynamically sizable cell in response to the amount of information contained in it at 120 . The size of the cell, in this embodiment, expands or contracts as necessary to display the items listed in the type of information associated with the cell. An appointment cell for example, in this embodiment, shows all the listed appointments, or other events, that are scheduled, up to a certain limit. That limit can be settable by the user within a certain range. The upper limit is constrained so that there is always display area available to show a message line in the display and, if there are tasks, or “to-do,” listed, a task list cell. The minimum limit for the appointment cell, also known as the “timed events” cell, is one appointment or a line informing the user that there are no appointments scheduled.
At 130 , other dynamically sizable cells are displayed, e.g., the cell listing to-do items. Each cell is also sized according to the amount of information to be displayed. In this embodiment, a cell showing message information can also be displayed and may remain sized for one line of information.
The relative size of the timed events cell and the to-dos cell in this embodiment is dynamic. As shown at 140 , the cells maximize and minimize interdependently, reflecting the number of items to be displayed at any one time and taking into consideration the number of active cells for display. The maximum extension of the two cells is flexible and relational, depending on the amount of left-over display area available. However, in case of conflict, there is a minimum number of rows defined for each cell. If the number of items to be displayed equals or exceeds this minimum, the cell will not contract.
For a square display, or a rectangular display with an uncollapsed active input area, the relational minimum cell size in this embodiment of the present invention is seven rows for events and two rows for to-do in one exemplary embodiment. For a rectangular display, also known as a “Tall App state,” it is eleven rows for events and four rows for to-dos as one example. The sizes of the cells described herein are based on the screen size of the employing device. It is noted that other embodiments can have more or fewer allocated rows for information without altering the scope of the dynamically sizable cell embodiments herein described.
It is noted here that cells are also sized so that, if each cell has such a small list of items to display that the aggregate of items will not fill the available display area, each cell can expand to jointly take up the spare space. In other embodiments, each cell can shrink to a user-preferred minimum and the surplus display area can remain unused.
In one embodiment, the message display cell and the to-do display cell are optional and may be deactivated according to user configurations. If the to-do cell is suppressed, in one example, the events cell automatically may increase in size. Alternatively, if the messages cell is suppressed, then the to-do cell may increase in size. If both the to-do cell and messages cell are suppressed, then the event cell may increase in size automatically. If the to-do cell does not use all its area to display, the spare area may be used to automatically enlarge the events cell. In embodiments of the present invention, a cell is not enlarged, as described above, unless it contains information to display in the expanded area.
FIG. 1B illustrates a method by which interrelational dynamic sizing is achieved in one embodiment of the present invention. In one embodiment, FIG. 1B may be viewed as an expansion of step 140 in FIG. 1 . If the to-do cell is suppressed 151 , and the message cell is not suppressed 153 , then the event cell is expanded as needed 155 up to absorb the area made available by the to-do cell's suppression. If the to-do cell is suppressed 151 , and the message cell is suppressed 153 , then the events cell can expand to use up to all of the display area as needed 156 .
If the to-do cell is not suppressed 151 , and there is extra space available in the to-do cell 152 , then, again, the event cell is expanded to take up available display area as needed 155 . If, however, the to-do cell does not have extra space 152 , and the message cell is suppressed 154 , then the to-do cell is expanded to absorb the message cell's unused space as needed 158 . If the message cell is not suppressed 154 , but the event cell has extra area 157 , then the to-do cell is again expanded as needed 158 , this time absorbing display area remaining from the event cell. In each case, in this embodiment, the cells display the maximum amount of appropriate information that can be shown in the available area 161 . When the information changes or when appropriateness of the information changes, such as when the scheduled time of an event passes, for example, then the process is repeated, 199 . The process is also repeated when the user enters new information or when the user enters new preferences.
FIG. 2A illustrates an embodiment of the present invention in which dynamically sizable cells are displayed on the screen of an electronic device. Exemplary square format display 201 comprises a clock display 202 , date display 204 , display select buttons 203 , dynamically sizable events cell 221 , dynamically sizable to-do cell 222 , and message cell 223 . In one embodiment, message cell 223 lists only one line of information. That line includes the total number of messages received and the number of those as yet unread. Other embodiments can enlarge the message cell information to include other information such as the title or sender of a high priority message, for example.
Dynamically sizable to-do cell 222 lists user-created tasks. The tasks, like the events listed in events cell 221 , are created in “creator” applications, such as an electronic calendar or appointment book software application. Embodiments of the present invention are enabled to accept events and tasks from a variety of applications. The exemplary task shown in cell 222 , in FIG. 2A , includes a due date and a past-due date. These time-constrained items can function, in this embodiment, as alarms.
Dynamically sizable events cell 221 is also shown. In addition to “today's” timed events, events upcoming soon are listed under “tomorrow.” This embodiment of the present invention lists the time of the event and the name or other reference as well as a “past” icon 205 or an “upcoming” icon 206 . In some embodiments, these icons change in accordance with the relation between the scheduled time and the clock time. In other embodiments, these icons can be changed by user input.
It is noted here that user input can be accepted in a number of ways in this embodiment. A user can touch the icon in the touch-screen display, in this example, with a stylus or other object. The user can also step through the icons and other screen entities using a five-way navigation button then change the icon status by using a select or other key. User input can also, in some embodiments, be accepted from an alpha-numeric keyboard.
The dynamic sizability of events cell 221 and to-do cell 222 are interdependent and their sizes also relate to the amount of information to be listed and to the number of active cells displayed. A user can, in this embodiment, select whether to display a cell or to suppress it entirely (e.g., deactivate it). FIG. 2B illustrates an embodiment of the present invention in which the to-do cell 222 is suppressed. Events cell 221 , in this example, automatically expands to absorb the display area otherwise used by the to-do cell and events cell 221 is able to list more of its contained event listings. Message cell 223 , in this example, remains at one message count line. Events cell 221 expands in size, in this example, only if it contains data to be displayed in the expanded area.
In FIG. 2C , message cell 223 has also been suppressed and events cell 221 expands to absorb all of the available display 201 , assuming it contains data to be displayed in the expanded area. Clock 202 and view select buttons 203 are not absorbed in this example, however. When events cell 221 is able to absorb all available display 201 area, a large number of event items can be listed. In this example, three events are listed for the day shown and five for the following day, each with schedule times and icons. Other embodiments are enabled to list more.
FIG. 2D illustrates a display in which message cell 223 has been suppressed and to-do cell 222 has expanded to take advantage of the now-available display area. In this embodiment of the present invention, the event cell 221 remains at its original size and the to-do cell 222 expands to absorb the area made available by suppression of the message cell 223 .
FIG. 2E illustrates the interrelational nature of dynamic sizing in these embodiments of the present invention. The layout of the timed events cell 221 and the to-do cell 222 is dynamic. The cells maximize and minimize interdependently, reflecting the number of items to be displayed at any given time and the active cells. The maximum extension of the two cells is flexible and relational and depends on how much left-over display area is available. However, in case of conflict there is a minimum number of rows defined for each cell which is user-selectable in this embodiment. Here, to-do cell 222 has automatically contracted one line to allow events cell 221 to list another upcoming event because cell 221 needed more area and cell 222 did not need the area.
In the example shown, the relational minimum size of the two dynamic cells defines the number of rows composing the two cells, if the number of items to be displayed equals or exceeds the user-defined minimum for both cells. It is noted that this occurrence has a higher probability in an embodiment employing a square aspect display. If the relational minimum size of one dynamic cell exceeds the number of items to be displayed, it will automatically contract and cede display area to the other cell. For to-do cell 221 on a square aspect display, this amount that can be ceded is only one row in this embodiment. The timed events is then enabled to display one more (single row) item. It is noted that other embodiments are enabled to expand and contract over more items, depending on the total screen size available.
FIG. 2F illustrates the display of an embodiment of the present invention when there is no content for a cell to display or no content of a particular type. If there is no content for an active cell, it does not fully collapse but rather displays a corresponding message and the other cell can absorb the remaining display up to the minimum reserved size of the no-content cell. Here, there are no events scheduled for “today” and the one-line message reads “No Appointments Today.” However the “tomorrow” portion of events cell 221 has content and that content is displayed as normal. To-do cell 222 also has no content and displays only the one line message “No ToDo Items Due.” It is noted here that these messages can vary in various embodiments. The specific wording used in this embodiment is only used here for illustrative purposes.
As shown in FIG. 2G , if both cells are devoid of information to be listed, both shrink to their relational minimums. The remaining display area remains blank, in this embodiment of the present invention.
It is noted that there are both timed and untimed events that can be scheduled in this embodiment of the present invention. FIG. 2H illustrates both timed and untimed events listed in events cell 221 . The untimed events for today are listed, in this example, at 251 , shown just below the date line. Tomorrow's untimed events are listed at 252 , in the upcoming events section of events cell 221 , in this embodiment. Untimed events in this embodiment also are denoted with an icon that is different from those of timed events and lack a start time indication. In this embodiment, with future days' untimed events being listed above timed events, a sufficient number of untimed events can displace timed future events to outside the events cell's available listing space and scrolling is required to view those timed future events. In other embodiments, however, untimed events may be listed beneath timed events.
Timed events, in this embodiment of the present invention, are shown in the events cell and scroll through the cell as time passes. Over time, timed events migrate to the top and, if there are no more hidden events for today, the timed events make room for future events in other days.
Today's events show the event title in bold font in this embodiment of the present invention, running over one line. If the event has a location field attached, the location field is shown on a second line.
Future events, though shown only as “tomorrow” in these illustrations, also include all other future days. If there is sufficient space available, future day's events are listed under the headings for the applicable days.
The display illustrated in this embodiment of the present invention enables the user to select a number of preferred settings for the display's presentation. The aforementioned minimum size for cells is one set of many selectable settings.
FIG. 3A illustrates the options pull-down menu employed in one embodiment of the present invention. “Display Options” is shown selected at 302 . Upon selection of display options, the display changes to that shown in FIG. 3B . Here, display options window 310 is characterized by a title bar 304 , view select button 305 , view indicators 307 , and window closing buttons 306 which are, in this example, “OK,” signifying acceptance of settings changes, and “Cancel,” signifying rejection of any entered settings changes. Display 310 also shows cell select buttons 311 and selected image window 312 . It is noted that in this embodiment of the present invention, an image can be selected from a group of images and used as background to many of the displays. The group of images can be assorted stock images or user created images or photographs. The Select Image display appears when the “Background Image” icon box is selected.
FIG. 3C illustrates selecting a background image in the select image display. Here, title bar 323 is labeled “choose an image” but some embodiments may use other phrasing. In this embodiment of the present invention, a selection of thumbnail images is presented for user selection at 321 . If there are more thumbnail images than can be presented at one time, the remaining images can be viewed by either stepping down by use of a navigation button or by stroking scroll arrow 322 with a stylus in the touch-screen display.
When an image is selected, its name appears in window 312 as shown in FIG. 3D and, in the embodiment, display 310 re-appears showing the selected image name. When “OK” is selected, the display returns to the today view display, 330 , with the selected image in the background. In this embodiment, the information listed in the dynamically sizable cells is not affected by the presence of a background image.
3 E, 3 F
FIG. 3G illustrates accessing a creator application in order to modify a timed event. Here, an upcoming timed event is highlighted 341 in display 223 . Highlighting and selecting, in this embodiment, causes the appearance 341 of day view display 342 . The selected timed event is denoted on the day view display as a highlighted time indicator 343 . In this embodiment, another selection, of the highlighted time indicator, allows further editing of the timed event. It is noted that the exemplary timed event in FIG. 3G has a start time of “4:30.” In the day view time listing, however, only times on the hour are listed. An “off-hour” time is only listed when an off-hour time has been selected as a start time for the timed event. FIG. 3G is also, in this embodiment, characterized by a date window 346 and a day of the week indicator button set 344 . Days of the week can be selected forward or backward in time by selecting arrows 345 .
Embodiments of the present invention can also be implemented in a rectangular display format as shown in display 400 in FIG. 4A and FIG. 4B . A rectangular display 400 can be called a “Tallscreen” display or a “Tall App State” in some embodiments. It is noted that display 400 is presented in a portrait orientation, with the vertical axis of the display aligned with the long axis of the touch-screen display. As shown in FIG. 4A , there is an active input area (AIA) 401 for user alpha-numeric input in the touch-screen display. The square area above the active input area is treated in the same manner as a square format display with events cell 221 , to-do cell 222 and message cell 223 shown in their square display relative sizes. Also present in display 400 are status bar 402 , clock display 202 and view select buttons 203 .
The active input area can be collapsed, or minimized, as shown in FIG. 4B , making its display area available to the dynamically sizable cells. When the display area is available, events cell 221 and to-do cell 222 each enlarge to take advantage of the increased area. It is noted that, in the default relationship in this embodiment of the present invention, an extra nine to eleven rows become available to event cell 221 and four rows become available to to-do cell 222 upon active input area collapse. Navigation in the listed information presented in a tallscreen display is in the same manner as in a square screen display.
A tallscreen display can be presented in a landscape orientation as shown in FIG. 4C and FIG. 4D . Here the vertical axis of display 410 is oriented with the short axis of the rectangular touch-screen. When the active input area is maximized, is presented, in this embodiment, on the right side of the display. It is noted here that some embodiments are enabled to present the active input area on the left side of the screen when in landscape mode. Again, when the active input area is maximized, the dynamically sizable cells are presented in a default square aspect display, as shown in FIG. 4C .
FIG. 4D illustrates the behavior of display 410 when the active input area is collapsed. Unlike the increase in available rows that occurs in portrait mode, event cell 221 , to-do cell 222 and message cell 223 increase in width to take advantage of the increased available display area. While no increase occurs in listed items, increased area is available more information as shown. It is noted that the status bar 402 in this embodiment occupies the end of the rectangular display, not having changed from its location in portrait mode. The clock 202 and view select buttons move, however, to remain in their respective locations in the display 410 .
FIG. 4E illustrates the behavior of a background image in tallscreen portrait mode when the active input area is minimized. In this embodiment, the image retains its size and orientation. If the stored image is larger than the presented image, then more of the stored image is presented. If the stored image and the presented image are of the same size, the presented image remains and a blank background is presented in the increased area.
FIG. 5 illustrates sizing a stored image to be presented as a background image in the tallscreen display, in portrait mode. Image 501 is larger than the area 502 that can be presented in the tallscreen display, 500 . In this embodiment of the present invention, the presented image is taken from the center of the stored image with an equal amount of cropping occurring on the left and right sides and on the top and bottom. In other embodiments, the user can select a portion of a stored image to present as a background.
FIG. 6 illustrates a portable electronic device in accordance with an embodiment of the present invention. In this illustration, the portable electronic device is implemented as a handheld computing device 600 . Device 600 is enabled with a touch-screen display 601 and an active input area (AIA) 602 .
Device 600 is also implemented with application buttons 604 and five-way navigation buttons 603 . The five-way navigation buttons shown at 603 comprise “up” button 605 , “down” button 606 , “left” button 607 , “right” button 608 and “pick” button 609 . “Pick” button 609 can also be known as a “select” button.
It is noted that the presence, use, and position of application buttons 604 may vary in different implementations without limiting effect on embodiments of the present invention. Device 600 is also equipped with a stylus 610 which allows a user to easily input to the device via the pressure sensitive membrane or digitizer of the touch-screen display, 601 .
Embodiments may employ variations of touch-screen display 601 . The implementation illustrated is a “tall screen” device, meaning that it is enabled to present more information than a substantially square screen device in that it is enabled to use active input area (AIA) 602 as an extension of the normal, square, display area. A tall screen device can also be known, when expanded, as a “Tall App State” device. It is noted that the presence, use, and position of application buttons 604 may vary in different implementations without limiting effect on embodiments of the present invention.
FIG. 7A illustrates another portable electronic device in accordance with an embodiment of the present invention. In this illustration, the portable electronic device is implemented as a handheld computer, 700 , enabled with wireless phone capabilities. Device 700 is enabled with a touch-screen display 701 .
It is noted that the particular device 700 illustrated is implemented in a folding or telescoping form factor. In this illustration, line 710 illustrates a dividing line between upper body portion 711 and lower body portion 712 which is shown slid over touch-screen display 701 , thus showing only the uppermost portion of the display. The form factor shown is only an example of implementations available in embodiments of the present invention and is not meant to limit embodiments to any particular form factor.
Portable electronic device 700 is enabled with a numeric keypad 703 which comprises, in this implementation, numeric keys 0-9 as well as “star” and “pound” keys. The exemplary keypad shown is only for illustration and is not meant to limit alpha-numeric input devices any particular form in embodiments of the present invention.
Portable electronic device 700 is also enabled with a five-way navigation button, 603 . The five-way navigation button comprises “up” button 605 , “down” button 606 , “left” button 607 , “right” button 608 and “pick,” or “select,” button 609 .
FIG. 7B illustrates portable electronic device 700 in an open position, with lower portion 712 retracted and exposing the full expanse of rectangular touch-screen display 301 . In the display's exposed position, active input area 702 is shown.
As discussed previously, embodiments of the present invention are enabled with an active input area, 702 , that can be “collapsed.” Collapsing the active input area allows the effective display area to expand, making use of the active input area when not needed for input. FIG. 7C illustrates portable electronic device 700 with active input area 702 collapsed to allow a graphical user interface display to be shown in the full expanse of the display area.
FIG. 8 is an illustration of a handheld computing in which embodiments of the present invention can be presented in a landscape mode. Device 800 presents touch-screen display 801 , which includes collapsible active input area 802 . Also included are application buttons 604 whose functions are the same as previously illustrated handheld devices. Five-way navigation buttons 803 are located in the same physical place in the device as when the display is presented in portrait mode. However, the functions of the individual navigation buttons change so that the user is able to keep the same user friendly orientation of up button 808 , down button 807 , left button 805 and right button 806 , and their associated cursor movements.
Embodiments of the present invention are expected to operate in a computer system, such as a handheld computing device. A configuration typical to a generic computer system is illustrated, in block diagram form, in FIG. 9 . Here, generic computer 900 is characterized by a processor 901 , connected electronically by a bus 910 to a volatile memory 902 , a non-volatile memory 903 , possibly some form of data storage device 904 and a display device 905 .
While it is noted that display device 905 can be implemented in different forms, embodiments of the present invention are implemented in devices equipped with touch-screen displays combining a liquid crystal display (LCD) screen and a pressure-sensitive input membrane overlaying the display. Other embodiments can be implemented with cathode ray tube (CRT) displays or other implementations.
Bus 950 also connects an alpha-numeric input device 906 and cursor control 907 . Embodiments of the present invention are enabled to accept alpha-numeric input by reading handwritten characters in the touch-screen display. In discussions above of embodiments of the present invention, handwritten characters are written in the active input area (AIA). Other embodiments can accept alpha-numeric input from keystrokes in a keypad. Cursor control in embodiments of the present invention is by either tapping appropriate areas of the touch-screen display with a stylus or by pressing appropriate elements of a five-way navigation button.
Communication I/O device 908 can be implemented as a serial port, USB, or infrared port. In various implementations, communication I/O device 908 may be realized as a modem, an Ethernet connection, a wireless device, or any other means of communicating signals between a computer system and a communications network. Some embodiments are enabled as wireless telephones. These phone-enabled devices also are equipped with telephone module 909 .
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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Embodiments of the present invention relate to methods and devices for displaying information in a handheld device, comprising displaying information in a dynamically sizable cell in the display of the handheld device, wherein the cell comprises a portion of the display and the size of the cell is adjusted in response to the amount of information it contains. Embodiments of the present invention are enabled to display the information in a plurality of dynamically sizable cells which display different categories of information. Embodiments are also enabled to adjust cell size in response to the size of the other cells in the display.
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[0001] This application is a continuation-in-part of application Ser. No. 10/162,780, filed Jun. 6, 2002, now abandoned.
BACKGROUND OF THE INVENTIO
[0002] (1) Field of the Invention
[0003] This invention relates to light source, particularly to the use of multicolor light emitting diode (LED) light source to produce a white light.
[0004] (2) Brief Description of Related Art
[0005] [0005]FIG. 1A shows a prior art to produce a colorless white light. The light source uses three color LEDs to produce a white light. A red color LED R, a green color LED G, and a blue color LED B are mounted on a substrate 10 , The three LEDs are then covered with a glue for protection.
[0006] [0006]FIG. 1B shows the color spectrum of such a light source. The red LED has a light spectrum with wavelength in the 580 nm-680 mm range and a peak at 640 nm. The green LED has a light spectrum with wavelength in the 480 nm-580 nm range and a peak at 530 nm. The blue LED has a light spectrum with wavelength in the 430 nm- 530 nm range and a peak at 480 nm. The white light in nature has light spectrum ranging from 400-780 nm wavelength. The artificial white light source using the R, G, B LEDs has peaks at 640 nm, 530 nm and 480 nm wavelengths, but lacks light spectrum below 430 nm wavelength, around 500 nm wavelength, around 580 nm wavelength and above 680 nm wavelength. Therefore, the combination of three color LEDs does not reproduce a true colorless light.
SUMMAR OF THE INVENTION
[0007] An object of this invention is to produce a colorless light source having the same light spectrum as the white light in nature. Another object of this invention is to produce a white light source with broader light spectrum than using the three color R, G, B LEDs. Still another object of this invention is to lower the cost of reproducing colorless light than the cost of using three color R, G, B LEDs.
[0008] These objects are achieved by using only two color LEDs and coving them with color phosphorescent glue. Alternatively, a single color LED is covered with two kinds of colored phosphorescent glues.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1A shows a prior art light source using three color LEDs.
[0010] [0010]FIG. 1B shows the light spectrum of the 3-color LED light source.
[0011] [0011]FIG. 2A shows a first embodiment of the present invention, using a green LED, a blue LED and a red phosphorescent glue.
[0012] [0012]FIG. 2B shows the light spectrum of the light source shown in FIG. 2A.
[0013] [0013]FIG. 3A shows a second embodiment of the present invention, using a red LED, a blue LED and a green phosphorescent glue.
[0014] [0014]FIG. 3B shows the light spectrum of the light source shown in FIG. 3A.
[0015] [0015]FIG. 4A shows a third embodiment of the present invention, using a blue LED , a green phosphorescent glue, and a red phosphorescent glue; FIG. 4B shows the light spectrum of the light source shown in FIG. 4A.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In recent years, the “red phosphorescent glue” (SrS:Eu) and the “green phosphorescent glue” (SrGa 2 S 4 :Eu) become popular. The cost is lower than the LED chips and the light spectrum is broader than a LED. These properties are utilized to produce a colorless light in the present invention.
[0017] [0017]FIG. 2A shows the first embodiment of the present invention. A green color LED G and a blue color LED B are mounted on an insulating substrate 10 [, which can be either metallic or insulating] such as a printed circuit board, to which the color LEDs can be coupled by wire-bonding or flip-chip technique. These two LEDs G and B are covered with a red phosphorescent glue R 1 . The light emitted from this structure is colorless as shown in the color spectrum in FIG. 2B. Note the red color spectrum of the red phosphorescent glue complements the colors of the LEDs and is considerably broader than the red LED spectrum response shown in FIG. 1A. Hence, the overall spectral response is also broader, approaching that of true natural white light.
[0018] [0018]FIG. 3A shows the second embodiment of the present invention. A red color LED R and a blue color LED B are mounted on a substrate 10 . These two LEDs R and B are covered with a green phosphorescent glue G 1 . The light emitted from this structure is colorless as shown in the color spectrum in FIG. 3B. Note that the spectral response due to the green phosphorescent glue G 1 complements the colors of the LEDs, and is broader then the green LED response shown in FIG. 1B. As a result, the spectral response is more uniform than that in FIG. 1B, approaching that of true natural white light.
[0019] [0019]FIG. 3A shows the third embodiment of the present invention. A single blue color LED B is mounted on a substrate 10 . The LED B is cover with a green phosphorescent glue G 1 and a red phosphorescent glue R 1 . The light emitted from this structure approaches that of a natural white light as shown in the spectral response in FIG. 4B. Note that responses due to the G 1 phosphorescent glue and the R 1 phosphorescent glue complement the color of the blue LED and are considerably broader than the corresponding green LED and red LED responses. Thus, the overall response shown in FIG. 4B is more uniform than that in FIG. 1B, approaching that of true natural light. Alternatively, a mixture of the green and red phosphorescent glue may also be used.
[0020] While the preferred embodiments of the invention have been described, it will be apparent to those skilled in the art that various modifications may be made to the embodiments without departing from the spirit of the present invention. Such modifications are all within the scope of this invention.
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A colorless light approaching that of white light in nature, is produced by using no more than two color LEDs covered with one or more layers of complementary color phosphorescent glue on an insulating substrate.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to electrical power distribution devices. More particularly, the present invention relates to electrical power distribution devices that can be plugged into a standard wall electrical outlet and provide further multiple electrical outlets into which electricity using devices may be plugged.
SUMMARY OF THE INVENTION
[0002] The present invention is an improved electrical power distribution apparatus. The invention, having rotatable female type electrical connection outlets or devices, has particular application for use in connecting multiple electricity using appliances, wherein the male plug type electrical connecting member of such appliances would not otherwise simultaneously be connectable in a conventional electrical power distribution apparatus, due to the size and geometry of such male plug type electrical connecting members.
[0003] It is well know that electrical connection outlets have long existed. Some samples of such electrical outlets include the common female two outlet wall mounted electrical connection apparatus in widespread use in the US and other countries, and the so-called “power strip” type electrical connection apparatus which typically includes some type of generally rigid housing having a plurality of female type electrical connection outlets, and an extension cord member including a male type electrical connection plug connected to the first end of the cord, and the second end of the cord being electrically connected to the plurality of female type electrical connection outlets. However, such conventional electrical connection outlets typically employ female type electrical connection outlets that are rigidly fixed to a housing and are not rotatable.
[0004] At least one example of a “power strip” having rotatable female type electrical connection outlets is know and is disclosed in U.S. Pat. No. 5,902,140 by Cheung et. al. U.S. Pat. No. 5,902,140 is expressly incorporated herein by reference. However, the electrical connection apparatus of '140, in contrast to the subject invention, does not provide for electrical connection unless the female type electrical connection outlets are in a certain spring-loaded predetermined rotated orientation and only in the certain spring-loaded predetermined rotated orientation. The '140 patent is intended to provide a safety apparatus that prevents children from inserting foreign objects into the female type electrical connection outlets, when the female type electrical connection outlets are in a nominal or non-rotated orientation.
[0005] It is further known that the differences in size and geometry of male type electrical connection plugs has proliferated in recent years. This is due in part to the additional functions that have been added to such male type electrical connection plugs. For instance, many male type electrical connection plugs incorporate an electrical power transformer as an integral portion of the male type electrical connection plug. Such transforming function can cause the male type electrical connection plug to take on a large overall cubic shape. Thus for instance, it is not uncommon to encounter a physical interference between two such power transforming male type electrical connection plugs, due to the size and shape of such power transforming male type electrical connection plugs and due to the spacing of conventional or non-rotating female type electrical connection outlets.
[0006] Because the subject invention provides rotatable female type electrical connection outlets that maintain electrical connectability regardless of the rotational orientation of the female type electrical connection outlets, the subject invention provides for simultaneous electrical connection of such otherwise non-simultaneously connectable male type electrical connection plugs by means of arranging the female type electrical connection outlets of the subject invention in a more connection friendly or physically non-interfering rotational orientation.
DESCRIPTION OF DRAWINGS
[0007] In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
[0008] FIG. 1 is a substantially isometric view of the improved electrical power distribution apparatus. The female type electrical connection outlets of the improved electrical power distribution apparatus are shown in various random rotational orientations. FIG. 1 includes a display of the top, front, and side surfaces of the improved electrical power distribution apparatus.
[0009] FIG. 2 is a substantially isometric view of the improved electrical power distribution apparatus. The improved electrical power distribution apparatus is depicted in an orientation such that the improved electrical power distribution apparatus is rotated downward approximately 90 degrees from the orientation shown in FIG. 1 . It is noted that such downward rotation defines a rotation about a theoretical axis defined by the intersection of the planes defined by the improved electrical power distribution apparatus top and right side substantially planer surfaces. FIG. 2 includes a display of the bottom, front, and right side surfaces of the improved electrical power distribution apparatus.
[0010] FIG. 3 is a substantially isometric view of the improved electrical power distribution apparatus, substantially similar to FIG. 1 except that a portion of the upper and lower housing of the improved electrical power distribution apparatus are shown as being cut away to reveal inner portions of the improved electrical power distribution apparatus. The upper and lower housing members are shown cross-hatched at their respective cut away areas.
[0011] FIG. 4 is a random trimetric view of the improved electrical power distribution apparatus. The improved electrical power distribution apparatus is depicted as having the near side half of the improved electrical power distribution apparatus cut away to reveal inner portions of the improved electrical power distribution apparatus. The upper and lower housing members are shown cross-hatched at their respective cut away areas. For drawing clarity, other components of the improved electrical power distribution apparatus that are cut away are not shown as cross-hatched.
[0012] FIG. 5 is a substantially exploded isometric view of the improved electrical power distribution apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0014] Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are included to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
[0015] In order to facilitate the understanding of the present invention in reviewing the drawings accompanying the specification, a feature table is provided below. It is noted that like features are like numbered throughout all of the figures.
FEATURE TABLE # Feature 10 Electrical power distribution apparatus in general 20 Upper housing 21 Upper housing interface recess 22 Upper housing female electrical connection device opening 23 Upper housing non-conductive male plug retention flange 24 Upper housing recessed channel 25 Upper housing indication light opening 26 Upper housing fastener post 30 Lower housing 31 Lower housing interface flange 32 Lower housing electrical power supply prong opening 33 Lower housing electrical power return prong opening 34 Lower housing strap retention flange 35 Lower housing fastener post 36 Lower housing fastener post reception recess 37 Lower housing electrical ground prong opening 40 Female electrical connection device 41 Female electrical connection body 42 Female electrical connection device power supply connection cavity 43 Female electrical connection device power return connection cavity 44 Female electrical connection device ground connection cavity 50 Female electrical connection device power supply bracket 51 Female electrical connection device power supply bracket upper connection surface 52 Female electrical connection device power supply bracket lower connection surface 54 Female electrical connection device power return bracket 55 Female electrical connection device power return bracket upper connection surface 56 Female electrical connection device power return bracket lower connection surface 60 Female electrical connection device ground bracket 61 Female electrical connection device ground bracket upper connection surface 62 Female electrical connection device ground bracket lower connection surface 70 Power supply strap assembly 71 Power supply strap 72 Power supply strap connection ring 73 Power supply strap connection ring interface surface 74 Power supply strap connection bar 75 Power supply strap prong 76 Power supply strap prong interface surface 80 Power return strap assembly 81 Power return strap 82 Power return strap connection ring 83 Power return strap connection ring interface surface 84 Power return strap connection bar 85 Power return strap prong 86 Power return strap prong interface surface 90 Ground strap 91 Ground strap connection pad 92 Ground strap connection pad interface surface 93 Ground strap connection bar 94 Ground strap connection prong 95 Ground strap connection prong interface surface 96 Ground strap mounting flange 97 Ground strap mounting flange hole 98 Ground strap ground prong passage hole 100 Non-conductive male connection plug 101 Non-conductive male connection plug base 102 Non-conductive male connection plug seating flange 103 Non-conductive male connection plug simulated power supply prong 104 Non-conductive male connection plug simulated power return prong 105 Non-conductive male connection plug simulated ground prong 110 Indication light
[0016] Referring now to the drawings and particularly to FIG. 5 , the invention is improved electrical power distribution apparatus 10 comprising an upper housing 20 a lower housing 30 , a plurality of female electrical connection devices 40 , a power supply strap assembly 70 , a power return strap assembly 80 , a ground strap 90 , a non-conductive male connection plug 100 , and a plurality of indication lights 110 . Female electrical connection device 40 comprises the assembly of a body 41 , a bracket 50 , a bracket 54 , and a bracket 60 . Power supply strap assembly 70 comprises the assembly of a power supply strap 71 and a prong 75 . Power return strap assembly 80 comprises the assembly of a power return strap 81 and a prong 85 .
[0017] Upper housing 20 defines a substantially radiused cubic shaped shell having an upper housing interface recess 21 (not shown), a plurality of cylindrically shaped upper housing female electrical connection device openings 22 , an upper housing strap retention flange 23 , an upper housing recessed channel 24 , a plurality of cylindrically shaped upper housing indication light openings 25 , and a plurality of cylindrically shaped upper housing fastener posts 26 . Upper housing 20 is formed of plastic and may be of any plastic that provides adequate structural and insulative properties, and is compatible with injection molding or like plastic fabrication processes.
[0018] lower housing 30 defines a substantially radiused cubic shaped shell having a lower housing interface flange 31 , a plurality of cubic shaped lower housing electrical power supply prong openings 32 , a plurality of cubic shaped lower housing electrical power return prong openings 33 , a plurality of cylindrically shaped lower housing strap retention flanges 34 , a plurality of cylindrically shaped lower housing fastener posts 35 , a plurality of lower housing fastener post reception recesses 36 , and a plurality of cylindrically shaped lower housing electrical ground prong openings 37 . Lower housing 30 is formed of plastic and may be of any plastic that provides adequate structural and insulative properties, and is compatible with injection molding or like plastic fabrication processes.
[0019] Female electrical connection device body 41 defines a substantially cylindrically shaped body having a substantially cubic shaped power supply connection cavity 42 , a substantially cubic shaped power return connection cavity 43 , and a substantially cylindrically shaped ground connection cavity 44 . Body 41 is formed of plastic and may be of any plastic that provides adequate structural and insulative properties, and is compatible with injection molding or like plastic fabrication processes.
[0020] Female electrical connection device power supply bracket 50 defines a formed substantially thin irregular shaped bracket having an upper connection surface 51 , and a lower connection surface 52 . Power supply bracket 50 is formed from a sheet of brass or like electrically conductive metal alloy.
[0021] Female electrical connection device power return bracket 54 defines a formed substantially thin irregular shaped bracket having an upper connection surface 55 , and a lower connection surface 56 . Power return bracket 54 is formed from a sheet of brass or like electrically conductive metal alloy.
[0022] Power supply strap 71 defines a formed substantially thin shaped strap having a connection bar 74 connected to a plurality of connection rings 72 , said connection rings 72 each having a connection ring interface surface 73 . Power supply strap 71 is formed from a sheet of brass or like electrically conductive metal alloy.
[0023] Power supply strap prong 75 defines a formed substantially thin elbow shaped prong having a prong interface surface 76 . Power supply strap prong 75 is formed from a sheet of brass or like electrically conductive metal alloy.
[0024] Power return strap 81 defines a formed substantially thin shaped strap having a connection bar 84 connected to a plurality of connection rings 82 , said connection rings 82 each having a connection ring interface surface 83 . Power return strap 81 is formed from a sheet of brass or like electrically conductive metal alloy.
[0025] Power return strap prong 85 defines a formed substantially thin elbow shaped prong having a prong interface surface 86 . Power return strap prong 85 is formed from a sheet of brass or like electrically conductive metal alloy.
[0026] Ground strap 90 defines a formed substantially thin strap having a plurality of connection pads 91 , a plurality of connection pad interface surfaces 92 , a plurality of connection bars 93 , a connection prong 94 , a connection prong interface surface 95 , a mounting flange 96 , a mounting flange hole 97 , and a ground prong passage hole 98 . Ground strap 90 is formed from a sheet of brass or like electrically conductive metal alloy.
[0027] Non-conductive male connection plug 100 defines a plug having a base 101 , a seating flange 102 , a simulated power supply prong 103 , a simulated power return prong 104 , and a simulated ground prong 105 . Plug 100 is formed of plastic and may be of any plastic that provides adequate structural and insulative properties, and is compatible with injection molding or like plastic fabrication processes.
[0028] Indication light 110 defines a substantially small colored lightable light and may be for instance a light emitting diode type light.
[0029] Female electrical connection device 40 is assembled such that brackets 50 , 54 , and 60 are retentatively and electrical conductively fastened into cavities 42 , 43 , and 44 respectively. Power supply strap assembly 70 is assembled such that strap 71 is retentatively and electrical conductively fastened to prong 75 . Power return strap assembly 80 is assembled such that strap 81 is retentatively and electrical conductively fastened to prong 85 .
[0030] Improved electrical power distribution apparatus 10 is assembled such that ground strap 90 , power return strap assembly 80 , and power supply strap assembly 70 are nested into lower housing 30 and in particular, are nested between the plurality of lower housing strap retention flanges 34 . Strap 90 and strap assemblies 80 and 70 are positioned such that each are electrically insulated from the other. Strap assembly 70 is further positioned such that power supply strap prong 75 passes through and protrudes from a power supply prong opening 32 . Strap assembly 80 is further positioned such that power return strap prong 85 passes through and protrudes from a power return prong opening 33 . Ground strap 90 is further positioned such that ground strap prong 94 passes through and protrudes from a ground prong opening 37 . Non-conductive male connection plug 100 is positioned adjacent to ground strap 90 such that plug base 101 is in contact with ground strap connection bar 93 , and such that plug prong 103 passes through and protrudes from a power supply prong opening 32 , and such that plug prong 104 passes through and protrudes from a power return prong opening 33 , and such that plug prong 105 passes through prong hole 98 , and such that plug prong 105 passes through and protrudes from a ground prong opening 37 . Female electrical connection devices 40 are snappingly engaged into upper housing 20 such that female electrical connection devices 40 are rotatably retained in upper housing openings 22 , and positioned such that cavities 42 , 43 , and 44 , are outwardly exposed through upper housing openings 22 . Indication lights 110 are fastened to upper housing 20 such that lights 110 pass through and protrude from indication light openings 25 . At least one of said indication lights 110 is electrically connected to strap assembly 70 and to strap assembly 80 such that when apparatus 10 is electrically powered, indication light 110 is lighted. With the members of improved electrical power distribution apparatus 10 assembled as described above, upper housing 20 is assembled to lower housing 30 such that upper housing fastener posts 26 engage with reception recesses 36 of lower housing posts 35 , and such that male plug retention flange 23 is in retaining relationship to male connection plug 100 , and such that power supply bracket lower connection surface 52 is in spring loaded electrically conductive contact with power supply strap connection ring interface surface 73 , and such that power return bracket lower connection surface 56 is in spring loaded electrically conductive contact with power return strap connection ring interface surface 83 , and such that ground bracket lower connection surface 62 is in spring loaded electrically conductive contact with ground strap connection pad interface surface 92 . Upper housing 20 and lower housing 30 are secured together by means of threaded mechanical fasteners (not shown) such as those that are traditionally well known in the fastening art. Such fasteners are threaded through and secured into upper fastener posts 26 and lower fastener posts 35 . Improved electrical power distribution apparatus 10 may be adapted such that non-conductive male connection plug 100 may float a small amount with apparatus 10 so as to compensate for a small amount of production manufacturing tolerance in corresponding wall power outlets.
[0031] In practice, with apparatus 10 assembled as described above, and protruding prongs 75 , 85 , and 94 functioning in combination as a standard male electrical connection plug, prongs 75 , 85 , and 94 of apparatus 10 , are inserted into an energized standard wall mounted electrical outlet or the like such that an electrical connection is made between prong interface surfaces 76 , 86 , and 95 and corresponding electrical connecting surfaces of the wall mounted electrical outlet. Further, a male electrical connection plug of an electrical power consuming appliance is inserted into a female electrical connection device 40 such that upper connection surfaces 51 , 55 , and 61 are placed in electrical connection relationship with corresponding surfaces of said male electrical connection plug, and such that regardless of the rotational orientation of female electrical connection device 40 , a completed electrical circuit is established, electrical power is distributed, and said appliance is electrically powered. Additionally, while said appliance is being powered, a rotation of female electrical connection device 40 will not interrupt said completed circuit. Because female electrical connection device 40 may be rotated while providing electrical power to said appliance, multiple appliances may be connected to apparatus 10 that would otherwise not be able to be connected to a conventional power distribution apparatus due to the non-rotatable power connection nature of female electrical connection devices of conventional power distribution apparatuses.
[0032] In an alternated embodiment, prongs 75 , 85 , and 94 of apparatus 10 are replaced with a conventional extension chord having a standard male electrical connection plug.
[0033] In another alternated embodiment, male connection plug 100 is replaced by a second instance of prongs prongs 75 , 85 , and 94 , with prongs 75 , 85 , and 94 being electrically connected to straps 71 , 81 , and 90 respectively, such that apparatus 10 includes two functional male type outlet plugs.
[0034] In yet another alternate embodiment, apparatus 10 includes a ground fault circuit interruption means or short circuit prevention means.
[0035] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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The Improved electrical power distribution apparatus is an invention that because of its unique rotatable live female electrical connection type outlets, is able to accommodate the simultaneous insertion of male type electrical connection plugs of a wide variety and shape. The accommodation of such simultaneous insertion of such male type electrical connection plugs provides for the simultaneous powering of a wide variety of appliances wherein such appliances would not otherwise be able to be simultaneously powered by conventional power distribution apparatuses due to the inability of such male type electrical connection plugs of irregular size and shape to be simultaneously inserted into conventional non-rotatable female electrical connection type outlets of conventional power distribution apparatuses. Furthermore, the female electrical connection type outlets of the present invention may be rotated while having male type electrical connection plugs inserted therein, and yet still maintain an electrical connection.
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FIELD
[0001] This invention relates to the field of fiber processing. More particularly, this invention relates to estimating the weight of disparate entities in a mixed volume, such as removing the weight of fibers in a volume of trash.
INTRODUCTION
[0002] Many quality evaluations have as their basic component a determination of the amount of a contaminant that is found within an amount of the desired material. The fiber processing industry is no different. For example, cotton fibers can be graded based upon how much trash is included within a given volume of fiber. As the term is used herein, “trash” refers to any non-primary-fiber material, such as husks, twigs, leaves, dirt, rocks, and any other non-primary-fiber material that might become mixed into the fiber volume. In the case of cotton fibers for example, trash refers to anything that isn't cotton fiber.
[0003] Various methods have been devised to estimate or actually measure the amount of trash within a given mixed volume of fiber and trash. In some methods, the mixed volume is opened in some manner, and the trash is mechanically separated from the fiber. The amount of the trash that is removed from the mixed volume is weighed, and the weight of the trash is used as the basis of the quality evaluation, such as by comparing the weight of the trash to the weight of the mixed volume, or to the weight of separated fiber, or some other such comparison.
[0004] Unfortunately, it is relatively difficult to separate the fiber from the trash in a mixed volume. This difficulty results in the process either taking a longer time than desired, or producing an incomplete separation of the mixed volume—with either some amount of trash remaining in the fiber, or some amount of fiber remaining in the trash.
[0005] What is needed, therefore, is a system by which problems such as those described above can be reduced, at least to some extent.
SUMMARY OF THE CLAIMS
[0006] The above and other needs are met by a method for determining a corrected weight of a mixed volume, by gravimetrically measuring a total weight of the mixed volume, creating an image of the mixed volume, detecting at least one selected component within the image of the mixed volume, estimating a component weight of the at least one selected component from the image of the mixed volume, and subtracting the component weight from the total weight to yield the corrected weight.
[0007] In this manner, the weight of the mixed volume can be corrected by electronic means. This means that the mixed volume does not need to be painstakingly separated in some time-consuming or labor-consuming process. Nor does the weight of the mixed volume need to be compromised by the weight of components that are not supposed to be left within the mixed volume. Thus, a corrected weight that accurately represents the desired component or components of the mixed volume can be quickly, easily, and automatically generated.
[0008] According to another aspect of the invention there is described a method for determining a trash weight of a mixed volume of trash and cotton fiber, by gravimetrically measuring a total weight of the mixed volume, creating an image of the mixed volume, detecting the cotton fiber within the image of the mixed volume, estimating a cotton fiber weight from the image of the mixed volume, and subtracting the cotton fiber weight from the total weight to yield the trash weight within the mixed volume.
[0009] According to yet another aspect of the invention there is described an apparatus for determining a corrected weight of a mixed volume, with a gravimetric scale for measuring a total weight of the mixed volume, a sensor for creating an image of the mixed volume, and a processor for detecting at least one selected component within the image of the mixed volume, estimating a component weight of the at least one selected component from the image of the mixed volume, and subtracting the component weight from the total weight to yield the corrected weight.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further advantages of the invention are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
[0011] FIG. 1 is a flow-chart of a method according to an embodiment of the present invention.
[0012] FIG. 2 is a functional block diagram of an apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0013] With reference now to FIG. 1 , there is depicted a flow-chart of a method 100 for correcting the weight of a mixed volume of material according to an embodiment of the present invention. The mixed volume is weighed, as given in block 102 . This weight can be accomplished in a variety of different ways. For example, the mixed volume can be directly weighed with a gravimetric device like a scale, or weighed with a balance. Whatever method is used, this initial weight of the mixed volume is designated herein as the total weight.
[0014] An image is then created of the mixed volume, as given in block 104 . In some embodiments, the mixed volume is scattered across a surface, such that all components of the mixed volume can be readily seen from one direction, such as from above the mixed volume. In this manner, the individual components of the mixed volume are not hidden, one by another, from the view-point of the imaging device. In some embodiments a single optical visible-light image from a single imaging device at a single location is used to create the image of the mixed volume. In other embodiments, multiple images from multiple sensors at multiple orientations are created, and in some embodiments wavelengths other than visible wavelengths are used to create the image or images. Other combinations of properties such as these are also contemplated.
[0015] Once the image has been obtained, as given in block 104 , an algorithm is performed using the image as an input. The algorithm discriminates the various components of the image, as given in block 106 . By “discriminates” it is meant that the various components of the mixed volume as depicted in the image are identified as to classification. For example, if the mixed volume is of fiber and trash, then those portions of the image that represent fiber are identified as one classification, and those portions of the image that represent trash are identified as another classification.
[0016] The algorithm can be adapted so as to identify more than two classes of components within the mixed volume, as desired. Various threshold levels can be set as desired so as to make the determination as to how a given portion of the image should be classified. Because in some embodiments the mixed volume does not completely cover the surface upon which is it disposed, the algorithm can be set, in those embodiments, to exclude from classification those portions of the surface that are visible in the image, as desired.
[0017] Once the image has been classified, as given in block 106 , the weight of at least one of the classes of material within the mixed volume is estimated, such as by the algorithm. In some embodiments, the weights of all of the classes of material within the mixed volume are estimated, or the weights of some variable number of the classes are estimated.
[0018] For example, returning to the example of a mixed volume of fiber and trash, the weight of the fiber in the mixed volume can be estimated by the algorithm in one embodiment. This can be accomplished by, for example, determining the total volume of fiber within the mixed volume (from the image), and then multiplying that total volume by a presumed or measured fiber density value. A variety of different algorithms for determining the weight of the fiber (or the trash) could be used in different embodiments. These determined weights are designated as the component weights.
[0019] After the weight of at least one component of the mixed volume has been estimated, as given in block 108 , the corrected weight of the volume is determined, as given in bock 110 , such as by subtracting one or more of the component weights from the total weight. For example, in the fiber and trash example, the component weight of the fiber can be subtracted from the total weight, yielding a corrected weight of trash in the mixed volume. Alternately, the component weight of the trash can be subtracted from the total weight, yielding a corrected weight of fiber in the mixed volume.
[0020] It is appreciated that some of the steps of the embodiment of the method as described above do not need to be performed in the order as described above or depicted in FIG. 1 . For example, measuring the total weight of the mixed volume, as represented in block 102 , does not need to be accomplished prior to imaging the mixed volume and estimating the component weight or weights, as given in blocks 104 - 108 . However, the steps of measuring the total weight and estimating at least one component weight do need to be accomplished prior to determining the corrected weight, as given in block 110 . In some embodiments, these steps of measuring the total weight and estimating at least one component weight are accomplished substantially simultaneously.
[0021] With reference now to FIG. 2 , there is depicted a functional block diagram of an apparatus 200 according to an embodiment of the present invention. A surface 218 receives the mixed volume 202 . In the example as depicted, the mixed volume 202 is comprised of components 204 , 206 , and 208 . For example, the mixed volume 202 might include trash 204 , unknown object 206 , and fiber 208 . A scale 210 measures the total weight of the mixed volume 202 , and provides the total weight to the processor 212 for further analysis. The sensor 214 records an image of the mixed volume 202 on the surface 218 within a field of view 216 , and provides the image to the processor 212 for further analysis. The processor 212 implements the algorithm as described above, and determines the corrected weight, as desired.
[0022] The foregoing description of embodiments for this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
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A method for determining a corrected weight of a mixed volume, by gravimetrically measuring a total weight of the mixed volume, creating an image of the mixed volume, detecting at least one selected component within the image of the mixed volume, estimating a component weight of the at least one selected component from the image of the mixed volume, and subtracting the component weight from the total weight to yield the corrected weight.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority for U.S. Provisional Application Ser. No. 60/350,273, filed Nov. 2, 2001.
FIELD OF THE INVENTION
[0002] The present invention is directed to apparatus for use in diagnostic molecular pathology and, more particularly, to such apparatus used for the automated staining and/or treating of tissue samples mounted on microscope slides.
BACKGROUND OF THE INVENTION
[0003] Molecular pathology is the examination at a molecular level of the DNA, mRNA, and proteins that cause or are otherwise associated with disease. From this examination important information about patient diagnosis, prognosis, and treatment options can be elucidated. The practice of molecular pathology is generally divided into two main areas: (i) analysis of DNA, mRNA, and proteins in intact cells (in-situ), and (ii) analysis of these biological materials after they have been extracted from tissues. The first category, to which the present invention is primarily directed, has the advantage that it allows the pathologist or scientist to study the histopathologic architecture or morphology of the tissue specimen under the microscope at the same time that the nucleic acid or proteins are being assayed. These techniques include immunohistochemistry (IHC) which looks at proteins, in-situ hybridization (ISH) which looks at nucleic acids, histochemistry (HC) which looks at carbohydrates, and enzyme histochemistry (EHC) which looks at enzyme chemistry. For example, ISH can be used to look for the presence of a genetic abnormality or condition such as amplification of cancer causing genes specifically in cells that, when viewed under a microscope, morphologically appear to be malignant. ISH is also useful in the diagnosis of infectious diseases as it allows detection not only of a microbial sequence but also of precisely which cells are infected. This may have important clinicopathologic implications and is an effective means to rule out the possibility that positive hybridization signal may have come from an adjacent tissue of no clinical concern or from blood or outside contamination.
[0004] IHC utilizes antibodies which bind specifically with unique epitopes present only in certain types of diseased cellular tissue. IHC requires a series of treatment steps conducted on a tissue section or cells (e.g. blood or bone marrow) mounted on a glass slide to highlight by selective staining certain morphological indicators of disease states. Typical steps include pretreatment of the tissue section to remove the paraffin and reduce non-specific binding, retrieval of antigens masked by cross-linking of the proteins from the chemical fixatives, antibody treatment and incubation, enzyme labeled secondary antibody treatment and incubation, substrate reaction with the enzyme to produce a fluorophore or chromophore highlighting areas of the tissue section having epitopes binding with the antibody, counterstaining, and the like. Most of these steps are separated by multiple rinse steps to remove unreacted residual reagent from the prior step. Incubations can be conducted at elevated temperatures, usually around 37° C., and the tissue must be continuously protected from dehydration. ISH analysis, which relies upon the specific binding affinity of probes with unique or repetitive nucleotide sequences from the cells of tissue samples or bodily fluids, requires a similar series of process steps with many different reagents and is further complicated by varying temperature requirements.
[0005] In view of the large number of repetitive treatment steps needed for both IHC and ISH, automated systems have been introduced to reduce human labor and the costs and error rate associated therewith, and to introduce uniformity. Examples of automated systems that have been successfully employed include the ES®, NexES®, DISCOVERY™, BENCHMARK™ and Gen II® staining Systems available from Ventana Medical Systems (Tucson, Ariz.). These systems employ a microprocessor controlled system including a revolving carousel supporting radially positioned slides. A stepper motor rotates the carousel placing each slide under one of a series of reagent dispensers positioned above the slides. Bar codes on the slides and reagent dispensers permits the computer controlled positioning of the dispensers and slides so that different reagent treatments can be performed for each of the various tissue samples by appropriate programming of the computer.
[0006] Instrumentation such as the Ventana Medical Systems ES®, NexES®, BENCHMARK® and DISCOVERY® systems are fundamentally designed to sequentially apply reagents to tissue sections mounted on one by three inch glass microscope slides under controlled environmental conditions. The instrument must perform several basic functions such as reagent application, washing (to remove a previously applied reagent), jet draining (a technique to reduce the residual buffer volume on a slide subsequent to washing), Liquid Coverslip™ application (a light oil application used to contain reagents and prevent evaporation), and other instrument functions.
[0007] The Ventana Medical Systems staining instruments mentioned above process slides on a rotating carousel. The instrumentation described herein has the slides fixed in a stationary position and rotates the basic processing stations above the fixed slides. The following details of how the slides are processed, the process algorithm, is the same regardless of the physical configuration.
[0008] The process of staining tissue on a slide consists of the sequential repetition of the basic instrument functions described above. Essentially a reagent is applied to the tissue then incubated for a specified time at a specific temperature. When the incubation time is completed the reagent is washed off the slide and the next reagent is applied, incubated, and washed off, etc, until all of the reagents have been applied and the staining process is complete.
[0009] It is desirable to permit any staining protocol for any of the slides being run, i.e. any combination of reagents and incubation times. In addition, to stain multiple slides as quickly as possible the instrument should process the slides simultaneously. This is feasible given that most of the time slides are just incubating, thus freeing up time to perform the washing, reagent application and other functions on other slides.
[0010] One algorithm to accomplish simultaneous staining (sometimes referred to as the “random access” method) is to create a task and time schedule for each slide in the run, then perform each task on each slide when the schedule calls for it. The problem with this method is that incubation times will not be accurate if the instrument is busy performing a task on one slide when it is time to be washing another slide (thereby completing incubation on that slide). The variation in incubation times will be unpredictable since the total number of slides and the slide protocols vary.
[0011] Slide processing using the lock step algorithm insures that all incubation times are -accurate and predictable irrespective of the number of slides processed or the variation in slide protocols. While incubation times are assured, the lock step algorithm implies that incubation times must be an increment of the fundamental incubation time period. In the above example the incubation period is two minutes, therefore total incubation times must be two, four, six, eight etc. minutes in duration. However, the preferred embodiment of the present invention uses a four minute incubation time. Generally this is not a particular limitation since typical incubation times are an order of magnitude longer than the fundamental incubation period.
[0012] Prior art staining systems typically include either convection or radiation to warm the samples above laboratory ambient temperatures for steps requiring elevated temperatures. Heating the slide improves staining quality by acceleration of the chemical reaction and can permit a reaction temperature more closely matching body temperature (about 37° C.) at which antibodies are designed to react. While such convection or radiant heating systems have been generally suitable for IHC, which is antibody based, they are less suitable for ISH, which is nucleic acid based and requires higher and more precise temperature control. In order to denature the DNA double helix of both the target sample and the probe so as to render them single stranded, the temperature must be raised above the melting point of the duplex, usually about 94° C. Precise temperature control is also required in ISH to effect probe hybridization at the desired stringency. The selected temperature must be low enough to enable hybridization between probe and target, but high enough to prevent mismatched hybrids from forming.
[0013] Hot air convection, conduction or radiant heat heating units typically employed with prior art automated tissue stainers do not permit the temperature of individual slides to be separately controlled. With prior art systems all of the slides are heated to the same temperature at any given time during the process. For example, U.S. Pat. No. 5,645,114 to Bogen et al. discloses a dispensing assembly adapted to carry a plurality of microscope slides. Individual slide holders containing resistive heating units are provided. However, with the assembly taught by Bogen et al., all of the slides would be heated to a common temperature because no means are disclosed for separate heating controls or for shielding slides from heat generated by adjacent slides.
[0014] Other difficulties frequently encountered in both IHC and ISH testing results from the manner in which the tissues are typically preserved. The mainstay of the diagnostic pathology laboratory has been for many decades the formalin-fixed, paraffin embedded block of tissue, sectioned and mounted upon glass slides. Fixation in such a preservative causes cross-linking of macromolecules, both amino acids and nucleic acids. These cross-linked components must be removed to allow access of the probe to the target nucleic acid and to allow the antibody to recognize the corresponding antigen. “Unmasking” the antigen and/or nucleic acid is typically accomplished manually with multiple pretreatment, protolytic digestion, and wash steps.
[0015] Prior to staining, complete removal of the paraffin is also required so that it does not interfere with antibody or probe binding. Deparaffinization normally is achieved by the use of two or three successive clearing reagents that are paraffin solvents such as xylene, xylene substitutes or toluene.
[0016] The foregoing discussion of the prior art largely derives from Richards et al. U.S. Pat. No. 6,296,809, assigned to Ventana Medical Systems, in which there is described apparatus and methods for automatically staining or treating multiple tissue samples mounted on microscope slides so that each sample can receive an individualized staining or treatment protocol even when such protocols require different temperature parameters. More specifically, there is described in the ' 809 patent apparatus comprising a computer controlled, bar code driven, staining instrument that automatically applies chemical and biological reagents to tissue or cells mounted or affixed to standard glass microscope slides. According to the '809 patent, a plurality of slides are mounted in a circular array on a carousel which rotates, as directed by the computer, to a dispensing location placing each slide under one of a series of reagent dispensers on a second rotating carousel positioned above the slides. Each slide receives the selected reagents (e.g. DNA probe) and is washed, mixed and/or heated in an optimum sequence and for the required period of time.
[0017] According to the '809 patent, individual slides are carried on thermal platforms radially mounted to the carousel. Sensors also mounted to the slide carousel, individually monitor and control each thermal platform separately. Apparatus made in accordance with the '809 patent is available commercially from Ventana Medical Systems, of Tucson, Ariz. as the DISCOVERY™ or BENCHMARK™ systems.
[0018] The present invention is a modification and improvement over the prior art including the apparatus and methods described in the '809 patent. More particularly, the present invention rather than bringing the slides to the reagent, stain, and wash stations, brings the reagent, stain and wash stations to fixedly positioned slides. That is to say, in the present invention the slides are fixedly positioned in the apparatus, and the various washing, staining and reagent fluids selectively delivered to the slides. Fixing the slides in position in the apparatus eliminates expensive and disposable dispensers, and simplifies wiring to the heaters, and also eliminates the potential that a slide may be dislocated by rapid start and stop movement of the slide carousel, which, in a worst case scenario could result in a domino or train-wreck effect where one dislocated slide hits the neighboring slide causing that slide to dislocate, and so forth. Additionally, maintaining the slides in fixed position eliminates inertial problems of a high-volume reagent and slide carousel. Thus, motors and bearings need not be so robust.
[0019] Further features and advantages of the present invention will be seen from the following detailed description, taken in conjunction with the accompanying drawings, wherein like numerals depict like parts, and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of the apparatus of the present invention shown with the slide cabinet shell removed;
[0021] FIG. 2 is a perspective view of the apparatus of the present invention shown in conjunction with a computer and other instruments with which it operates;
[0022] FIG. 3 is a perspective view and FIG. 3 a is an exploded view of details of the nozzle plate portion of the present invention;
[0023] FIG. 4 is an exploded view of details of the slide plate portion of the present invention;
[0024] FIGS. 5 and 6 are perspective views, from the top and the bottom, respectively, of portions of the slide plate portion of the present invention;
[0025] FIG. 7 is a perspective view of the reagent plate portion of the present invention;
[0026] FIG. 8 is a perspective view showing two reagent bottles of the present invention;
[0027] FIG. 9 is a top plan view of two reagent bottles of the present invention; and
[0028] FIG. 10 is a flow chart of the operation and control of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, there is illustrated in FIG. 1 a perspective view of the molecular pathology apparatus according to the present invention which is designated generally by reference numeral 10 . For the purposes of clarity, several of the reagent bottles, as well as the cabinet shell, and liquid and air supply tubing and electrical wiring are omitted from the drawings. Apparatus 10 is designed to automatically stain or otherwise treat tissue mounted on microscope slides with nucleic acid probes, antibodies, and/or other reagents in a desired sequence, time and temperature. Tissue sections so stained or treated are then to be viewed under a microscope by a medical practitioner who reads the slide for purposes of patient diagnosis, prognosis, or treatment selection.
[0030] In a preferred embodiment, apparatus 10 functions as one component or module of a system 12 ( FIG. 2 ) which also comprises a host computer 14 preferably a personal computer, monitor 16 , keyboard 18 , mouse 20 , bulk fluid containers 22 , waste container 23 and related equipment. Additional staining modules or other instruments may be added to system 12 to form a network with computer 14 functioning as a server. Alternatively, some or all of these separate components could be incorporated into apparatus 10 making it a stand-alone instrument. Referring also to FIGS. 3-7 , as set forth in greater detail below, a plurality of slide platforms 50 are mounted radially about a center point 32 of drawer 34 upon which standard glass slides 60 with tissue samples may be placed. Drawer 34 is preferably constructed of stainless steel and is slidably mounted in housing 30 on rails 40 or the like. The temperature of each slide may be individually controlled by means of sensors and a microprocessor, i.e. as taught in the above-mentioned '809 patent.
[0031] Each of the slide platforms 50 is connected through individual wires and a wiring harness (not shown) to a microprocessor. A feature and advantage of the present invention which results from fixedly mounting the slide platforms in drawer 34 is that each of the heaters and thermal sensors may be hardwired thereby eliminating the need for a slip ring assembly or rotor couplings, as well as complex stepping motors, etc. for locating and positioning a rotating slide carousel as required in prior art devices. Also, the possibility that a slide or slides may be shifted or dislocated during rapid start and stop rotation of the slide carousel is eliminated.
[0032] In a particularly preferred embodiment, a plurality of slots or channels are formed on the top surface of each of the slide heaters, i.e. the interface surface between the slide heater and the slide, for gathering and venting gas bubbles as may form during heating, i.e. in accordance with co-pending U.S. application Ser. No. 09/953,417, filed Sep. 11, 2001, and assigned to the common assignee, which disclosure is incorporated herein by reference.
[0033] Referring also to FIGS. 1, 2 , 5 and 6 , drawer 34 includes a circular pan 35 having a peripherial wall 36 serving as a splash guard, a peripheral trough 37 and a central drain 38 , i.e. at center point 32 , both connected to drain lines ( 39 ) which in turn are connected to waste container 23 . Drawer 34 is slidably mounted in housing 30 on rails 40 . Rails 40 , in a preferred embodiment, comprise three piece telescoping rails so that the drawer 34 may be slid clear of housing 30 to permit access to all of the slide platforms 50 for slide loading and removal. A damping means 42 such as a pneumatic means, electromotive means, mechanical spring damper or the like preferably is provided to smooth movement of the drawer whereby to avoid possible dislodging of slides, particularly when the drawer is closed. Also, in a preferred embodiment of the invention, rails 40 are supported on a lift mechanism such as pneumatic cylinders 52 (see FIG. 1 ), which automatically index to permit the rails 40 to move up and down so that the drawer 34 may be dropped to permit wall 36 to clear the nozzle plate 100 when the drawer is slid in and out of the apparatus.
[0034] Slide drawer 34 is divided into thirty-five equal pie-shaped sections 70 . Thirty of the pie-shaped sections 70 are occupied by slide platforms 50 while the five remaining pie-shaped sections 70 A ( FIG. 4 ) at the rear of the drawer are devoid of slide platforms 50 . In other words, a row of thirty slide platforms 50 are radially mounted on drawer 34 and evenly spaced from one another, except at the ends of the row.
[0035] However, the invention is not limited to thirty active slide locations, and more or fewer slide locations may be employed. An alternative embodiment may be implemented by aligning the platforms 50 linearly, which results in potentially limitless number of platforms.
[0036] Referring to FIGS. 1 and 3 , a nozzle plate 100 is concentrically and rotatably mounted above slide drawer 34 . Nozzle plate 100 is mounted on a shaft (not shown) supported by a bridge 110 , and driven by a computer controlled stepping motor and drive belt (not shown), and rotates 185° plus or minus from a home position 104 at the rear of the drawer. The computer controlled stepper motor and drive belt are conventional in this art. Accordingly, details are omitted for the sake of clarity.
[0037] Nozzle plate 100 carries the various slide treatment stations, other than the reagent dispensing station. Thus, nozzle plate 100 carries dual rinse nozzle block 102 , volume adjust/stringency block 103 , Liquid Coverslip™ evaporation inhibitor liquid application block 104 , vortex mixer air jet block 106 , jet drain knives 108 , and the like, all for preparing a slide for staining, stain removal, and the like, and to clear bar codes 110 carried on the slides, and a bar code reader 109 , all as described in detail in U.S. Pat. No. 5,654,200 to Copeland et al, which disclosure is incorporated herein by reference. In other words, nozzle plate 100 carries all of the functions for slide preparation, cleaning, reagent mixing, Liquid Coverslip™ application, etc. other than reagent application, as described in the '200 patent to Copeland et al., plus wash stations 121 , 122 for the reagent application probes as will be described in detail below.
[0038] Preferably, but not necessarily, the various rinse nozzle blocks, vortex mixer air jet blocks, air knives, etc. are arranged adjacent to one another so that the nozzle plate may be indexed and advanced in a “lock-step” manner to sequentially treat a slide according to an accepted protocol. For example, air knives 108 may be arranged immediately adjacent rinse nozzle blocks 106 so that nozzle plate 100 may be advanced in “lock step” manner past a selected slide, and the slide rinsed and fluid stripped, etc. Also, if desired, vortex mixer airjet blocks 106 may be oriented to impinge simultaneously on two adjacent slides.
[0039] For the sake of clarity, fluid and air supply tubing for the several slide treatment stations have been omitted from the drawings. It will be understood, however, that the fluid and air supply tubing are made long enough to permit 185° rotation of the valve plate so that each slide treatment station can reach each slide 60 . A pair of wash stations 121 , 122 spaced two thirty-fifths of a revolution (approximately 20.572°) apart as will be described in detail hereinafter, are also attached to and radially extend beyond the periphery of the nozzle plate 100 , and rotate with the nozzle plate 100 .
[0040] Reagent plate 300 is fixedly mounted to arch 110 vertically above nozzle plate 100 , which arch in turn is fixedly mounted within housing 30 . A plurality of reagent bottles 302 are removably mounted within recesses 304 formed equally spaced adjacent the periphery of reagent plate 300 . In the illustrated embodiment, a total of thirty-five reagent bottles are mounted on the reagent plate, spaced approximately one thirty-fifth (approximately 10.286°) apart.
[0041] The reagents may include any chemical or biological material conventionally applied to slides including nucleic acid probes or primers, polymerase, primary and secondary antibodies, digestion enzymes, pre-fixatives, post-fixatives, readout chemistry, counterstains, and the like.
[0042] Referring also to FIG. 8 , the reagent bottles 302 each comprise a cylindrical hollow body 305 closed at the bottom end by an integrally formed bottom wall (not shown). Each bottle 302 includes an integrally formed bracket 306 which serves to maintain the bottles 304 at a desired height in reagent plate 300 , and which serves also to permit the stringing together of a plurality of like bottles 302 . Accordingly, each bracket 302 includes a hinge element 308 for cooperating with a hinge element 310 of an adjacent bottle 302 . In the illustrated embodiment, hinge elements 308 and 310 are shown as conventional pin-hinges in which the upper hinge 308 includes a pin 312 which fits into the lower hinge 310 , i.e. similar to a conventional door hinge. However, bottles 302 may be hinged together in a variety of ways.
[0043] Bracket 306 preferably includes a flat surface 314 upon which is carried a bar code 316 for identifying the contents of the bottle 302 . Bottles 302 also include an insert 318 having a tapered top surface 320 fitted in the top end of the bottles for locating a reagent transfer probe as will be described in detail hereinafter, and a cap 322 which may be either twist or snap-fitted to the bottle 302 for sealing the bottle 302 .
[0044] Making brackets 306 attachable to one another permits a lab worker to assemble a chain of reagents for use, and also to remove the chain of reagents so that the reagents may be refrigerated, for example, overnight when not in use.
[0045] Referring next to FIG. 9 , the side walls 324 of brackets 306 are tapered so that a pie-shaped space 326 is formed between two bottles when two bottles are fastened together in a string, and mounted in recesses 104 in the reagent plate 300 , thereby exposing holes 328 formed through reagent plate 300 . Holes 328 are formed in the same concentric circle as recesses 304 , and are spaced equidistant between adjacent recesses 304 . The purpose of pie-shaped spaces 326 and holes 328 is to provide clearance for reagent transfer probes 402 , 404 as will be described in detail below.
[0046] Referring again to FIG. 1 , an arm 400 is rotatably mounted on arch 405 concentrically above reagent plate 300 , and carries a pair of reagent transfer probes 402 , 404 located at the distal end of arm 400 and spaced approximately 10.286° apart. Arm 400 also carries a bar code reader 406 for reading bar codes 316 on the reagent bottles. Arm 400 is rotatably driven by a computer driven stepping motor (not shown), and rotates plus or minus 185° in either direction from a home position 410 .
[0047] Reagent transfer probes 402 and 404 , which are identical to one another, preferably comprise automatic pipette metering/dispensing pick-up devices designed to aspirate or “sip” reagent from a reagent bottle, move to a slide, and then “spit” or deposit the reagent onto the slide. “Sip” and “spit” automatic pipette/metering dispensing pick-up devices are described in published PCT Application No. PCT/US99/04379, which disclosure is incorporated herein by reference. Reagent transfer probes 402 and 404 are carried on the distal end of arm 400 and are spaced from one another so that when one of the probes, e.g. probe 402 is located centrally over a slide 60 , the other reagent transfer probe 404 may be centrally positioned over one of the two probe wash stations 121 or 122 . A pneumatic cylinder (not shown) selectively raises and lowers probes 402 and 404 into one of the following positions: a raised transport position above the tops of the bottles 302 where the arm 400 is free to rotate; a reagent drawing position wherein one of the probes is inserted into a selected reagent bottle 302 wherein a measured amount of reagent may be drawn into the probe; a reagent dispensing position wherein a reagent transfer probe containing reagent is disposed in the pie-shaped space 326 between two reagent bottles, above a selected slide to dispense reagent thereon; and a cleaning position wherein the other probe, i.e. the probe not being used to dispense reagent, is operatively disposed in one of probe washing stations 121 or 122 . While the apparatus of the present invention could be made with only a single reagent transfer probe, providing two spaced reagent transfer probes essentially doubles cycle speed since reagent metering may be accomplished using one of the two reagent transfer probes while the other of the two reagent transfer probes is going through the wash cycle as will be described below. That is to say, while one of the reagent transfer probes, e.g. reagent transfer probe 402 is dispensing reagent onto a slide, the other reagent transfer probe, i.e. idle reagent transfer probe 404 may be lowered to a probe wash station 121 where the idle reagent transfer probe may be rinsed inside and out at the same time.
[0048] Referring to FIG. 10 , the overall process is as follows:
[0049] A plurality of specimen-bearing slides 60 are mounted on the slide platforms 50 , selected reagent bottles 302 mounted in the reagent plate, the slide drawer is closed and the slide bar codes are read. The computer than downloads the run steps for the entire run, the nozzle plate 100 is indexed to the first slide, and the slide is washed and prepared for staining or other treatment in accordance with the pre-programmed run steps by advancing the nozzle plate in “lock-step” manner. In the meanwhile, probe arm 400 is rotated to the appropriate reagent bottle 302 , one of the two reagent transfer probes 402 or 404 is indexed over the selected reagent bottle, and the probe lowered to aspirate a measured amount of the desired reagent. The reagent-containing transfer probe is then raised, and the arm 400 moved to the selected slide where the loaded reagent transfer probe is lowered to just over the slide, and the reagent dispensed on the slide. In the meanwhile, the idle reagent transfer probe is lowered into one of the washing stations 121 or 122 , wherein the reagent transfer probe is washed inside and out. Both reagent transfer probes 402 and 404 are then raised, and the process repeated, but using the reagent transfer probe just cleaned in the previous step to aspirate and dispense reagent onto the next slide. As before, simultaneously with dispensing the reagent onto the slide as in the previous case, the idle reagent transfer probe is washed while the active reagent transfer probe is dispensing reagent onto the new slide.
[0050] The foregoing steps are repeated until all of the slides are processed. For convenience, in the illustrated embodiment, the dwell time at each slide station is approximately six and two-thirds seconds. This comes from dividing a four minute cycle time into thirty-six time spaces, one time space for each of the thirty slide positions plus five blank slide positions, plus one “virtual” time space for returning the arm 400 from the last slide position to the first slide position. The virtual slide position allows the nozzle plate to return to the other end of its travel range in an uninterrupted fashion.
[0051] The staining algorithm used on the aforesaid Ventana systems avoids the above problem by using a “lock step” method. The lock step algorithm requires that the nozzle plate which holds the processing functions be rotated one slide position index every n seconds, termed the slide index time. The slide index time is preferably as short as possible but long enough that the function that requires the longest time can be completed within the index time. Index times are usually on the order of several seconds. The time for one complete rotation of the nozzle plate, termed the fundamental incubation period, will then be n times the number of slide positions. (For example, if the slide index time is six seconds and there are twenty slide positions, the incubation time period will be 120 seconds or two minutes.)
[0052] Throughout the entire run the nozzle plate is indexed one slide position every n seconds. After the index, the system checks the schedule to see if any of the slides at each of the processing stations require the function of that, station. For example, if the slide at the washing station is scheduled for washing, that slide is washed. Similarly if the slide at the reagent application station is scheduled for the application of a new reagent, then the new reagent is applied.
[0053] The above-described invention has several advantages over the prior art. For one, making the slide plate fixed in position reduces the possibility of a slide being dislocated during the rapid start-stop rotational movement of a slide carousel. Also, employing two transfer syringes insures better cleaning of transfer syringes without increasing cycle time. Also, using vials or bottles for reagents eliminates the prior art's reliance on complex and costly dispensers.
[0054] Also, since none of the moving elements, i.e. nozzle plate 100 and probe support arm 400 need travel more than plus or minus 185° in either direction, all electrical connections, and air and fluid-connections can be achieved without the need for slip ring or rotary connections, since the hoses and wires are quite capable of taking twistings of 185° plus.
[0055] The instrumentation described herein may or may not have the ability to continuously rotate the nozzle plate. The nozzle plate may need to return to a starting position before rotation has exceeded 360 degrees. This may also be required when the slides are rotated on a carousel and the processing functions are fixed above the slides. Similarly, other non rotating designs are possible such as linear or two dimensional configurations. In these cases there will be a requirement to move the slides or processing functions back to the original starting position during the staining run. In most cases it is likely that the time required to do this will exceed the index time which violates the fundamental requirement of the lock step algorithm. The lock step algorithm can still be used by introducing the concept of a “virtual slide”. The virtual slide is added to the-total number of slides so that the index time period assigned to the virtual slide may be used to move the slides or processing stations back to the starting position. Thus accurate and predictable incubation times are maintained.
[0056] While a preferred embodiment of the invention has been described, the invention is susceptible to-modification. For example, instead of using one or a pair of transfer syringes on an overhead arm, the reagent carousel could carry a plurality of micro-delivery reagent fluid dispensers such as described in U.S. Pat. Nos. 5,232,664 or 5,654,200 or 6,093,574 or 6,192,945. Moreover, while the use of individually heated thermal platforms is preferred, the slides may be heated using conventional convection heating techniques. Still other changes may be made without departing from the spirit and scope of the invention.
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Apparatus and methods for automatically staining or treating multiple tissue samples mounted on slides are provided, in which the slides and reagent bottles are held in fixed position, and the reagent and wash solutions brought to the slides.
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BACKGROUND OF THE INVENTION
The present invention relates to the field of chemical vapor deposition with the assistance of a plasma, and more specifically, it relates to an apparatus for plasma activated chemical vapor deposition, the apparatus comprising, disposed one after another:
a plurality of transformation means for transforming the state of respective precursors of a plurality of deposition materials to cause each of them to pass from an initial state to the gaseous state;
a plurality of charging means for charging vector gases with respective gaseous precursors, each precursor-charged vector gas constituting a predetermined gaseous mixture;
a plurality of transfer means for transferring said predetermined gaseous mixtures to a plasma reactor having microwave excitation comprising a reaction enclosure, a microwave generator, and at least one waveguide interposed between said generator and the enclosure and providing non-resonant coupling; and
injection means for injecting said predetermined gaseous mixtures into the reaction enclosure.
Apparatuses of the type to which the invention applies are designed to form deposits of special materials, in particular of ceramics, on substrates. It is thus possible, in particular, to make thermal barriers which, when deposited on an appropriate protective coating (e.g. of MCrAlY material), enable turbine blades to be made that are well protected thermally: the operating temperature of the metal portions remains below the allowed limit for the base material and the protective coating, while the temperature of the gas at the inlet of the turbine can be considerably hotter (50° C. to 100° C.), thereby correspondingly increasing the efficiency of the turbine.
At present, three methods are known for obtaining thermal barriers:
1. The most widely used technique is plasma spraying. Grains of partially-stabilized zirconia powder are inserted into a plasma jet; they melt therein and are accelerated so as to be projected at high speed against a facing substrate. They solidify thereon rapidly and they adhere thereto by mechanically engaging roughnesses previously formed on the surface of the part, generally by sandblasting. The resulting coatings have a flaky structure that results from the stacking up of droplets that have flattened and solidified in lens-shapes, with solidification being accompanied by microcracking. The highest performance deposits are constituted by a layer of zirconia partially stabilized by 6% to 8% by weight of yttria deposited on an underlayer of MCrAlY alloy (where M═Ni and/or Co and/or Fe), itself deposited by plasma spraying under a controlled atmosphere. Generally, the ceramic layers obtained in this way are about 300 μm thick. This technique leads to deposits having microcracks and that may be constituted by metastable phases, with deposition speeds being very high, of the order of 100 μm/min. It should nevertheless be observed that the method is directional and that parts of complex shapes are difficult or even impossible to cover. Furthermore, the roughness of such deposits makes finishing treatment necessary to achieve a surface state that is aerodynamically satisfactory.
2. The method of evaporation under electron bombardment makes use of an electron beam emitted by a heated filament. The beam is accelerated by application of an electric field and it is directed by means of a magnetic field onto the material to be evaporated, in the present case a bar of yttrium-containing zirconia. Under the effect of such electron bombardment, the species are evaporated and condensed on the substrate that is placed facing the source. The substrate is optionally biased and is preheated and/or heated during the deposition operation. The results obtained by implementing this method present certain advantages:
the roughness of the layer obtained in this way is better adapted to aerodynamic flow;
the column structure of the deposit improves its thermomechanical behavior;
it has higher resistance to erosion; and
the layer adheres better.
However, it should be observed that making a coating of yttrium-containing zirconia at a high deposition speed (100 μm/h) requires high electrical power to evaporate the bar of refractory oxide. In addition, implementation of this technique requires considerable investment and a large amount of know-how. Furthermore, this method is likewise directional, i.e. parts that are complex can be difficult or even impossible to coat.
3. The radiofrequency cathode sputtering method makes it possible to deposit thin layers of yttrium-containing zirconia at low deposition speeds of the order of 1 μm/h. In this method, a material raised to a negative potential is subjected to bombardment by positive ions. The atoms of the material are ejected in all directions and condensed, in particular on the substrate placed facing it so as to have a deposit formed thereon. Systems have been used to make deposits of insulating materials (deposits of oxides in particular) with possible modifications (magnetron, spraying in a reactive atmosphere, etc.) in order to increase deposition speeds (up to a few μm/h). With this technique, it is certainly easier to control the composition of deposits than it is with the method of evaporation under electron bombardment; however deposition speeds are much slower and, as in the two preceding methods, deposition takes place directionally.
An essential object of the invention is to provide a novel deposition apparatus which enables the respective advantages of chemical vapor deposition and of plasma assistance to be combined, and in particular: a method which is non-directional, takes place at a lower temperature and at an increased deposition speed, and a deposit which has a structure that is controlled.
SUMMARY
To this end, a plasma activated chemical vapor deposition apparatus as defined in the above preamble is essentially characterized, when in accordance with the invention, in that the transfer means for transferring the respective predetermined gaseous mixtures are independent of one another, and in that the injection means include a nozzle of frustoconical external profile into which the above-mentioned independent transfer means open out and which is provided with at least one injection orifice, the end of said nozzle being shaped as a function of the desired configuration for the jet of ionized gas, said nozzle being fitted with means for heating and for thermally insulating the predetermined gaseous mixture.
DESCRIPTION OF PREFERRED EMBODIMENTS
If the precursor used is in the solid state or the liquid state, then advantageously provision is made for the transformation means for transforming the state of the precursor to comprise at least one chamber fitted with means for adjusting temperature and/or pressure to transform the precursor into the gaseous phase.
If the precursor is in the solid state, then it is desirable for the charging means for charging a vector gas with gaseous precursor to be organized so that the vector gas passes through the precursor in powder form.
The above-mentioned vector gas may either be neutral or else chemically reactive with the gaseous precursor.
Preferably, the transfer means for transferring the predetermined gaseous mixture include at least one transfer tube that is heated and/or thermally insulated, and at least one stop valve that is heated and/or thermally insulated. When a plurality of different predetermined gaseous mixtures need to be injected into the enclosure, provision may be made for a mixing chamber into which all of the respective transfer tubes for the different predetermined gaseous mixtures open out and which is disposed upstream from the injection orifice.
For injection proper into the reaction enclosure, the nozzle may be arranged in any manner appropriate to the looked-for results: it may be provided with a single outlet orifice, or it may be provided with a multiplicity of outlet orifices defined by subdivision means (such as a grid, a trellis, or a perforated plate) so as to ensure maximum ionization of the jet of gas in the form of a column bearing against the carrier of the sample to be coated that is disposed in the enclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic overall view of the essential means implemented in the plasma activated vapor deposition apparatus of the invention;
FIG. 2 is a cross-section through the sample carrier fitted with independent biasing and heating means, as used in the FIG. 1 apparatus;
FIG. 3 is a cross-section view through the means for injecting into the reaction enclosure of the FIG. 1 apparatus; and
FIGS. 4A, 4B, and 4C show different shapes that can be adopted for the injection nozzle of the means of FIG. 3.
DETAILED DESCRIPTION OF THE EMBODIMENTS
With reference initially to FIG. 1, the microwave plasma activated chemical vapor deposition apparatus comprises a metal enclosure 10, e.g. made of brass, having a case that is generally rectangular or circular in shape.
The enclosure 10 includes an internal cylindrical tube 12 that is centered relative to the enclosure 10 and whose wall is made of a material that has low dielectric losses, such as quartz.
The tube 12 has a circular opening 14 at its upper end and a circular opening 15 at its lower end.
The top portion of the enclosure 10 includes a circular opening 16 centered relative to the enclosure 10 and of a diameter substantially equal to the diameter of the opening 14 of the tube 12. The circular opening 16 is fully closed by a circular metal cover 17 made of stainless steel, for example. The cover 17 is pierced at its center by an orifice allowing a tube 18 to pass therethrough, the end of the tube having a special geometrical shape (e.g. cylindrical, hemispherical, or frustoconical) and opening out into the tube 12.
The circular opening 15 of the bottom portion of the tube 12 communicates with the outside via another cylindrical opening 29 of diameter substantially equal to that of the opening 15 and formed in the cover of a metal box 30 made of stainless steel, for example, and on which the tube 12 stands.
The apparatus also includes a microwave generator 20 emitting at a frequency of about 2.45 GHz and at a power of 1.2 kW.
A waveguide 21 conveys the microwaves to the tube 12 by non-resonant coupling in which the tube 12 does not dissipate the microwave energy communicated thereto in the form of electromagnetic radiation when gas is present in said tube 12. The electromagnetic energy propagates along the waveguide 21 in its longitudinal direction (arrow 19), with the electric field E extending perpendicularly to the direction 19.
A bidirectional coupler 25 is provided in the initial portion of the waveguide 21. In its intermediate portion 23 of rectangular section, the waveguide includes a plurality of penetrating adjustment screws 26 enabling the impedance of the reactor to be matched so as to obtain good efficiency in the transmission of microwaves towards the tube 12. The terminal portion 24 of the waveguide becomes progressively thinner in the direction parallel to the field E and wider in the direction perpendicular to the field E so as to achieve a right cross-section that is flat, rectangular, and substantially equal to the width of the enclosure 10.
The intermediate portion of the enclosure 10 is subdivided into two half-enclosures 11 and 13 which are separated from each other by a space (or gap) of rectangular right cross-section equal to that of the terminal portion 24 of the waveguide. The space (or gap) formed in this way permits non-resonant coupling of the waveguide with the tube 12.
On its side diametrically opposite from the microwave feed 21, the tube is provided with non-resonant coupling. The non-resonant coupling is established by a piston-type short circuit 27 having a flat rectangular right cross-section substantially equal to that of the terminal portion of the waveguide 24. The position of the piston 27 is adjusted to define a desired microwave electric field in the tube 12.
Inside the enclosure 10, a second microwave short circuit 28 is provided that is coupled to the tube 12. The second short circuit 28 is constituted by an annular plate that is also of the piston type. The plasma originates in the tube 12 and it may be confined to a greater or lesser extent by adjusting the height of the annular plate 28.
The box 30 is generally circular in shape and it contains the sample carrier 31 which supports the part to be coated that is capable of being rotated (the part is not shown but it occupies the position referenced 32), with the sample carrier being placed coaxially inside the tube 12. The sample carrier 31 is movable in vertical translation, thereby enabling it to carry the part 32 out from or into the plasma that is produced in the tube 12.
The tube 12 and the box 30 are evacuated by primary pump means 33 (e.g. using Roots type pumps delivering about 125 cubic meters per hour) associated with a pressure gauge 34 that has an inlet connected to the box 30 and an outlet connected to a pressure controller 35. In response to the pressure measured by the gauge 34, the pressure controller 35 actuates a motor that opens or closes a valve 36 connected to the primary pump means 33 for the purpose of controlling the pressure in the enclosure.
With reference now to FIGS. 1 and 2 together, for the purpose of cleaning a surface prior to deposition, the apparatus of the invention includes DC generator means 37 suitable for establishing a DC bias between the gas flow inlet means 18 and the metal portion 31a, e.g. made of copper, of the sample carrier 31. Sometimes it is also necessary to heat the sample during such cleaning and/or while the deposit proper is being made. To this end, the apparatus further includes independent heating means 38 constituted by a coil of resistance wire disposed inside an alumina shell 38a. The heating system is regulated by means of an external unit 39 controlled by a probe placed near the position 32.
The connection established between the voltage and temperature control units 37 and 38 respectively with the biasing and heating elements 31a and 38 are provided via sealed passages 38b.
With reference now to FIGS. 1 and 3, the apparatus of the invention includes means enabling gas to be fed via the tube 18 into the tube 12. The system for inserting precursors of the elements constituting the intended deposit is made up of two main zones having the following functions, respectively:
converting the precursor from its initial state to the gaseous state; and
conveying the precursor in the gaseous state into the reaction enclosure 12.
The precursors of the elements that constitute the deposit may be solids, liquids, or gases. With solids, the precursors are placed in enclosures 40 in which they are transformed into gaseous form by the effects of temperature and/or pressure. These enclosures 40 include heating elements 49a and thermal insulation 50a, and they are connected upstream via conventional flexible or rigid tubes 41 to gas cylinders 42 that may contain either reagent gases or else inert gases. Control means 43 such as flowmeters and flow rate controllers enable the gas flow rate in the tubes to be controlled and regulated. The vector gases travel past the precursors (solid, liquid, or gaseous) and, downstream from the enclosures and once charged with gaseous precursors, they penetrate into tubes 44 adapted to conveying gaseous mixtures. The tubes 44 are conventional tubes, each being provided with a heater 49b and thermal insulation 50b. In addition, the tubes 44 are fitted with stop valves 45 that are heated 49a and thermally insulated 50a to enable the precursor to be isolated. It is thus possible at will either to return the precursor to the air or to keep it under the atmosphere of vector gas, depending on the risk of damage.
With reference to FIGS. 4A to 4C, the various precursors, all in gaseous form, may optionally be mixed in a mixing chamber 51 provided for this purpose in the injection nozzle 52, which nozzle is tapering in outside shape and terminates the tube 18 where it opens out into the tube 12.
The nozzle 52 is provided with a single orifice 53 (FIG. 4A) or else with multiple orifices 54 (FIGS. 4B and 4C), that are smaller than the section of the tube 18.
The terminal portion of the tube 18 has an original geometrical shape, i.e. a truncated cone into which the vector gases charged with gaseous precursors for making the deposit, either via a single orifice 51a or via a plurality of orifices which may be defined by a grid or a trellis 51b, for example (FIG. 4B), or else by a perforated plate in the form of a spherical cap 51c (FIG. 4C), which shape makes it possible to ensure maximum ionization of the gas jet in the form of a column bearing on the sample carrier. The width of said column is a function of the geometrical shape selected for the injection nozzle (it increases on going from a single orifice to multiple orifices).
By way of example, and with reference to FIGS. 1 and 3, the use of the apparatus of the invention is now described in the case of depositing a zirconium oxide. The metallic precursor is in the form of powder 40d and it is contained in a filtering crucible 40a made of quartz which is itself received in an enclosure 40b made of stainless steel. This enclosure is placed in an enclosure 40 that enables the powder to be heated by means of a system of heating collars 49a. The temperature of the enclosure 40 is regulated by means of an external unit that is controlled by a probe 40c placed in the powder. The oxygen, a reagent gas, is itself conveyed by means of a conventional tube 41a.
Argon, an inert gas, is inserted into the enclosure 40a by means of the tube 41. The powder heated under reduced pressure is converted to the form of a gas. The inert gas becomes charged with the gaseous precursor, passes through the powder, and is inserted into the enclosure 12 together with the oxygen via the tube 44. The tube 44 is heated by a system of heating cords that are coiled 49b and thermally insulated 50b, and the entire assembly is held in the tube 18. Handles 48 fixed on the tube 18 enable said tubes to be moved vertically. When in the high position, the stop valve 55 may be closed so as to isolate the precursor. The cover 17 and all the elements attached thereto may be moved in vertical translation by a lifting system 46.
The oxygen over argon flow rate ratio may vary in the range 2 to 10. Tests have been performed with pressures in the enclosure lying in the range 100 Pa to 1000 Pa. Coupling is adjusted by positioning the piston 27 and the matching screws 26. It has been possible to obtain a layer of column structure monoclinic zirconia at an average deposition speed of 100 μm/h on a substrate of MCrAlY alloy.
In general, the apparatus of the invention makes it possible to make any type of ceramic coating insofar as precursors exist or can be produced and are transportable in gaseous form. The ceramics may be made up of pure oxides (SiO 2 , Al 2 O 3 , . . . ), combinations of oxides (ZrO 2 & Y 2 O 3 , SiO 2 & GeO 2 , . . . ), metalloids (C, B, Si, . . . ), combinations of metalloids (SiC, B 4 C, BN, . . . ), or indeed metalloid/metal combinations (TiC, TiB 2 , AlN, . . . ).
An application of the apparatus lies in making thermal barriers of zirconia partially stabilized with yttria. Uses can be envisaged in the field of turbines (fabrication of fixed and moving blades).
Other applications may relate in particular:
to insulators for microelectronics;
to solid electrolytes for high temperature fuel cells;
to mirrors for laser optics; and
to alumina/zirconia composites (depositing matrix material on fibers, strands, fabrics).
The apparatus can be used in general in the surface coating and treatment industry. For example, mention may be made of its application to making cutting tools.
Naturally, and as can be seen from the above, the invention is not limited in any way to the particular applications and embodiments that have been considered more particularly; on the contrary, it extends to all variants.
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Apparatus for plasma activated chemical vapor deposition, the apparatus comprising a microwave-excited plasma reactor with a reaction enclosure (10), a microwave generator (20), a waveguide (21) providing non-resonant coupling, and insertion means (40-54) for inserting at least one flow of a predetermined gaseous mixture into the enclosure; the insertion means comprise, in order: transformation means (40-43) for transforming the state of a precursor of a material to be deposited to bring it to the gaseous state, feed means (41, 42) for feeding a vector gas suitable for being charged with the gaseous precursor to constitute the above-mentioned predetermined gaseous mixture; and injection means (18) for injecting the predetermined gaseous mixture into the enclosure (10) and comprising an externally frustoconical nozzle provided with an injection orifice situated at one end and shaped as a function of the injection orifice and of the column configuration of the plasma formed, said nozzle having means for heating and thermally insulating the gaseous mixture.
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This application is a continuation of application Ser. No. 08/202,417, filed Feb. 28, 1994, now U.S. Pat. No. 5,502,091 and a CIP of 07/812,534, filed Dec. 23,1991now U.S. Pat. No. 5,338,407.
This invention relates to a process for making paper to enhance the dry strength of the paper produced without reducing its softness, that comprises adding to a pulp furnish a combination of cationic and anionic polymers.
BACKGROUND OF THE INVENTION
One of the major problems that tissue and towel manufacturers face is the unacceptable reduction of dry strength in paper products such as tissue and toweling in which a high degree of softness as well as dry strength is essential, resulting from the use of an increasing percentage of recycled or secondary pulp, chemithermomechanical pulp (CTMP) (CTMP) and groundwood, and the consequent reduction in average fiber length. Softness is a very important property in paper used for making high quality tissues and toweling, and procedure modifications or additives that achieve a compensating increase in paper strength normally decrease paper softness or increase stiffness. There is therefore a need for an effective additive that will enhance paper strength without adversely affecting the softness off the paper.
The tissue and towel manufacturers get the softness of their products evaluated by the perception of a human panel. Because it is a very subjective test, correlation of any single laboratory test evaluation with the perception test results may sometimes be difficult. However, extensive research efforts by workers in this area have shown that the results of a bending stiffness test by itself or in combination with tensile stiffness data correlate very reasonably with human perception evaluation.
European published Pat. No. 0 362 770 A2 (Application No. 89118245.3) discloses a mixture of cationic and anionic polymers as a strengthening additive for papermaking processes, essentially for unbleached pulps containing black liquor. The mixture comprises a water-soluble, linear, cationic polymer having a reduced specific viscosity greater than 2dl/g and a charge density of 0.2 to 4 meq/g, and a water-soluble, anionic polymer having a charge density of less than 5 meq/g that is reactable in the presence of water with cationic polymer to form a polyelectrolyte complex. Combinations of cationic guar (for example, guar "derivatized" with glycidyltrimethylammonium chloride) and cationic acrylamide copolymers, with anionic polymers in addition to those already contained in the black liquor (including sodium carboxymethyl guar) are disclosed. The preferred anionic polymer content is constituted by those polymers naturally present in unbleached pulps made by either chemical or mechanical pulping.
U.S. Pat. No. 3,058,873 discloses a combination of polyamide-epichlorohydrin resins with cellulose ethers or cationic starches for improving paper wet strength, specifically the use of CMC CT, a crude technical grade of carboxymethyl cellulose (CMC), and a polyamide-epichlorohydrin resin to improve wet strength in paper.
Published Japanese patent application JP 53106803 A, for which no counterpart exists, discloses paper production having improved wet strength and transparency by forming sheet from cellulosic material, carboxyalkyl cellulose and polyamide-epichlorohydrin resin, drying and treating with acid. Specifically, the method comprises (1) preparing a sheet from a mixture of (a) cellulosic material and (b) partially substituted carboxy-(lower alkyl)-cellulose of which the degrees of substitution (D.S.) is 0.10-0.50, followed by coating the resulting sheet with (c) polyamide-epichlorohydrin resin (or preparing a sheet from a mixture of (a) +(b) +(c), (2) drying the sheet, and (3) treating the dried sheet with a diluted acid solution. The partially lower-alkyl-carboxylated cellulose (typically CMC of D.S. 0.10-0.50) is firmly fixed on the cellulosic pulp when the polyamide-epichlorohydrin resin is present.
It would be desirable to provide a process for making paper from a bleached pulp furnish that uses a combination of cationic and anionic polymers to enhance the dry strength of the paper more efficiently than the known processes.
SUMMARY OF THE INVENTION
According to the invention, a process for making paper to enhance the dry strength of the paper produced without reducing its softness comprises adding to a bleached pulp furnish, separately or together, (1) an anionic polymer selected from the group consisting of carboxymethyl guar, carboxymethyl bean gum, carboxymethyl hydroxyethyl guar (such as the carboxymethyl guar available under the name Galaxy 707D from Aqualon and the name Jaguar 8707 from Hi-Tek), and a carboxymethyl hydroxypropyl guar (such as the carboxymethyl guar available under the name Jaguar 8600 from Hi-Tek), and (2) a cationic polymer selected from the group consisting of a cationic guar, a cationic acrylamide copolymer, a cationic bean gum, and a cationic wet strength resin that is an amine polymer-epichlorohydrin resin, such as polyamide-epichlorohydrin (PAE) resin, a polyalkylenepolyamine-epichlorohydrin (PAPAE) resin, or an amine polymer-epichlorohydrin (APE) resin, preferably the reaction product of a dibasic acid, more preferable adipic acid, with a polyalkylenepolyamine, more preferably a polyethylenepolyamine, in which amine polymer-epichlorohydrin resin amine groups have been alkylated and crosslinked with epichlorohydrin to produce a polyamide-epichlorohydrin resin that has azetidinium or epoxide functionality.
A polyamide-epichlorohydrin resin may more specifically be described as a poly(aminoamide)-epichlorohydrin resin, and is sometimes called a polyamide-polyamine-epichlorohydrin resin. If the cationic additive is a wet strength resin the benefits of the invention are achieved and the wet strength of the paper is additionally increased.
In a bleached pulp furnish, the combination of additives according to the invention is significantly more effective as a dry-strength additive than the same mounts of each of the cationic guar or the anionic guar, while maintaining substantially the same degree of softness (as measured by bending stiffness) as found in paper lacking a conventional dry-strength additive. A combination of an anionic guar and a cationic acrylamide copolymer is similarly more effective than the acrylamide copolymer alone as a dry strength additive at the same level of addition. These advantages are only achieved if bleached pulp is used in the process according to the invention.
Preferably, the wet strength resin is added to the anionic/cationic guar combination according to the invention. A combination of an anionic guar, a cationic guar (or acrylamide copolymer) and the wet strength resin is more effective than a combination of a cationic guar (or acrylamide copolymer) and the wet strength resin, all the other conditions being the same. It is at least as effective as a combination of an anionic guar and the wet strength resin.
When clear solutions of the individual components of the mixtures according to the invention are added together, aggregates of fine colloidal particles (which are usually called coacervates), apparently bound together by some physical or chemical force, are formed. This combination provides dry strength enhancement for paper that is higher than the strength enhancement provided by the same mount of either the cationic guar or the anionic guar, demonstrating a synergistic effect from the aggregates of fine colloidal particles that is substantially identical to the results obtained by adding the same anionic and cationic compounds individually to the pulp system. The cationic additive may also be a wet strength resin, when added with the anionic compound either individually to the pulp system or as coacervates. In either case, the presence of the anionic compound very significantly enhances the efficiency of a wet strength resin, and the use of the coacervates has the advantage of convenience.
The invention also comprises a composition for modifying a paper pulp slurry to enhance the dry strength of the paper produced without substantially reducing its softness comprising (1) an anionic polymeric component selected from the group of polymers consisting of carboxymethyl guar, carboxymethyl bean gum, carboxymethyl hydroxyethyl guar, and a carboxymethyl hydroxypropyl guar, and (2) a cationic polymeric component selected from the group of polymers consisting of a cationic guar, a cationic acrylamide copolymer, a cationic bean gum, a cationic wet strength resin, and both a cationic wet strength resin and at least one of the other of said cationic polymers, the wet strength resin being an amine polymer-epichlorohydrin resin selected from the group consisting of a polyamide-epichlorohydrin (PALE) resin, a polyalkylenepolyamine-epichlorohydrin (PAPAE) resin, and an amine polymer-epichlorohydrin (APE) resin, in which amine polymer-epichlorohydrin resin amine groups have been alkylated with epichlorohydrin to produce a polyamine-epichlorohydrin resin that has azetidinium or epoxide functionality.
Preferably in the said composition, the anionic polymeric component is a carboxymethyl guar and the cationic polymeric component is a cationic guar and a cationic wet strength that is produced by reacting a saturated aliphatic dicarboxylic acid containing three to ten carbon atoms with a polyalkylenepolyamine, containing from two to four ethylene groups, two primary amine groups, and one to three secondary amine groups (such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine), to form a poly(aminoamide) having secondary amine groups that are alkylated with epichlorohydrin to form a PAE resin. Most preferably, the wet strength resin is Kymene 557H (available from Hercules Incorporated), in which adipic acid is reacted with diethylenetriamine to form a poly(aminoamide) that is alkylated and crosslinked with epichlorohydrin to form a PAE resin. The invention also comprises a paper product containing the said composition according to the invention, and a process for making the composition comprising adding adding a mixture of the anionic guar and the cationic guar, preferably as an aqueous suspension, to a paper pulp slurry and then adding the wet strength resin later to form the composition in the slurry.
Under the normal wet end conditions of papermaking, the combination of additives according to the invention enhances paper strength through ionic bonds. That enhancement is an important feature for toweling, toilet tissue, or any other fine paper in which softness and dry strength or a combination of dry and wet strength, without compromising softness, are valued properties.
A cationic guar molecule with no anionic guar will have all its ionic groups available bond with the cellulose-fiber ionic groups of opposite charge. Thus, a cationic guar by itself is expected to offer a higher number of ionic bonds. When an anionic and a cationic guar are mixed together either in the presence of pulp or by themselves, an interaction takes place between them and this results in a lower number of ionic sites in the combination to bond with cellulose fibers. (A similar effect occurs when a wet strength resin, such as Kymene 557H, is in the additive system). Hence, the higher effectiveness of a combination as a dry strength is unexpected, particularly since it is not present if used with unbleached pulp containing black liquor.
According to the results obtained with various guar additives, this synergistic effect of an anionic and a cationic guar additive is independent of the chain-length of the compound as well as molecular weight as measured by solution viscosity. It is also independent of the charge density of the additives. However, the degree of effectiveness of the combinations depends on the molecular weight. There is evidence that the relatively higher molecular weight guars produce relatively-higher paper strength.
DETAILED DESCRIPTION OF THE INVENTION
Guar is a natural copolymer consisting of galactose and mannose, usually in the ratio of 1 to 2, in a linear chain of β-d-mamopyransyl with λ-D-galactopyranosyl units as side branches. An anionic guar is obtained by reacting a natural guar with caustic and subsequently with monochloroacetate. The resultant product is a carboxymethyl guar (CMG). Similarly, carboxymethylhydroxypropyl guar (CMHPG) is prepared by reacting natural guar with caustic and subsequently with monochloroacetate and propylene oxide. Examples of CMG are Galaxy 70713 D, (Aqualon), Jaguar 8707 (Hi-Tek) and those of CMHPG are WG-18 (Aqualon), Jaguar 8600 (Hi-Tek). Carboxymethyl hydroxyethyl guars are other examples of anionic guar additives.
A cationic guar is obtainable by reacting natural guar with caustic and subsequently with quaternary ammonium chloride, and is available from Dow as Dow Quart 188; such a cationic guar is available under the name Gendrive 162.
The structure of natural guar gum is as follows: ##STR1##
Polyacrylamide is prepared by polymerization of acrylamide with N,N'-methylene bisacrylamide. A cationic polyacrylamide is usually prepared by making reacting polyacrylamide with acryloxytrimethyl ammonium chloride (ATMAC), methylacryloxytrimethyl ammonium chloride (MTMAC) or diallyldimethyl ammonium chloride (DADMAC). The anionic acrylamide compounds are usually copolymers of acrylamides and sodium acrylates.
The preferred wet strength resins are produced by reacting a saturated aliphatic dicarboxylic acid containing three to ten carbon atoms, preferable adipic acid, with a polyalkylenepolyamine, containing from two to four ethylene groups, two primary amine groups, and one to three secondary amine groups, such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine, to form a poly(aminoamide) having secondary amine groups that are alkylated with epichlorohydrin to form tertiary aminochlorohydrin groups. These groups self-alkylate to form hydroxyazetidinium groups which are considered responsible for wet strength in paper. They are cationic in character. If tertiary amines are present in the aminopolyamide or polyamine backbones, quaternary epoxide groups are produced. The actual procedure for synthesizing these wet strength resins differ from product to product, but the objective to generate aminopolyamide-epichlorohydrin functionality remains the same.
Kymene® wet strength resins are most preferred. Some examples of wet strength resins available from Hercules Incorporated are Kymene 557H, Kymene 450, and Kymene 2064 (an APE resin based on methyldiallylamine monomer that is polymerized to an amine polymer precursor), as well as low absorbable organic halide (AOX) versions such as Kymene 557LX. Most preferred is Kymene 557H, in which adipic acid is reacted with diethylenetriamine (DETA) to form a poly(aminoamide) that is alkylated and crosslinked with epichlorohydrin to form a PAE resin, namely, adipic acid-DETA poly(aminoamide) epichlorohydrin.
The specific amount and the type of the additives will depend on, among other the type of pulp characteristics. The ratios of the anionic and the cationic additives may range from 1/20 to 10/1, preferably from 2/1 to 1/2, and most preferably about 1/1. The combination according to the invention is effective when added to the pulp stock in the amount of 0.05 to 5 percent, depending on the type of pulp. The preferable level of addition is 0.1 to 2% based on the dry weight of pulp.
Since the additive combinations of the invention consist of two or more components, they can be added to the furnish in different ways that may affect the rate of production in the plant and the properties of the final product. The usual procedure is to add these additives individually in the wet end system in a predetermined sequence to achieve what experiment shows to be the most desirable product. Preferably, however, these additives are introduced into the wet end system by combining the anionic and cationic additives beforehand and adding the resulting coacervates.
In the following examples, handsheets were prepared from pulp which was refined in a Valley beater to 500±5 cc Canadian Standard Freeness. The 22.50% consistency pulp slurry was diluted to 266% solids with normal tap water in a proportioner where the combination of additives according to the invention were added to the pulp while stirring. An aliquot of this pulp slurry was further diluted to about 0.023% consistency in a Deckle box for molding handsheets. Both refining and papermaking were made at pH 7.5 to 8.0. Thus, the papermaking process consists of three main steps. They are (a) formation of an aqueous slurry of cellulose fibers, (b) addition of dry strength additives and (c) formation of sheet and drying to a desired moisture content (preferably 3 to 6 percent).
The step (b) may be carried out by adding the anionic component to the pulp first, followed by the cationic component, and the wet strength resin if used. Blends of anionic and cationic components may also be added to the pulp directly in the papermaking system, Whether individually or blended together, the additives are mixed into the wet end of the paper machine, preferably under shear.
Tensile strength, modulus, and elongation were measured in an Instron, according to a standard procedure, Tappi 494, as a guide. Drying was to a moisture content of 3 to 6 percent. By the same testing procedure, the tensile energy per unit volume that the fibers have assimilated up to the point of rupture was also determined. This is referred to as tensile energy absorption (TEA). The results of bending stiffness presented here have been measured in a Handle O'Meter (Thwing-Albert Instrument Co.).
The same testing procedure measures the combined effect of sheet stiffness, surface friction, and thickness that affect the subjective perception of softness of paper products. (Holger Hollmark, TAPPI Journal, p 97, February 1983; Handbook of Physical and Mechanical Testing of Paper and Paperboard, Ed. Richard E. Mark, Ch. 11, p 511, 1983).
EXAMPLE 1
This Example is a laboratory evaluation of strength properties and bending stiffness on handsheets prepared with 70/30 Northern Softwood/CTMP furnish. The results are shown in Table 1. The anionic additives were first added to the pulp followed by the cationic additive. The control used in this case is a handsheet prepared with the same pulp with no additive. Galaxy 707D is a carboxymethyl guar (DS 0.08), and Gendrive 162 is a quaternary ammonium chloride treated guar (DS 0.075). Jaguar 8600, available commercially as Hi-Tek, and WG-18, are hydroxypropylcarboxymethyl guars. Guar AQU-3129 and High DS cationic guar (404-48-3) are available from Aqualon, a Hercules Incorporated unit. WC-100 and Hercofloc 1129 sodium acrylate-acrylamidecopolymer and sodium polyacrylate homopolymer, respectively. Reten® is a polyamide-epichlorohydrin polymeric material used as a retention. The "Jaguar" products are available from High-Tek Co.
TABLE 1__________________________________________________________________________ Bending Enhancement, % Control StiffnessAnionic Cationic Tensile % ofAdditive Percent Additive Percent Strength TEA Elongation Control__________________________________________________________________________None -- Gendrive 162 1.0 6.5 -- -- --Galaxy 707D 0.5 Reten ® 200 0.4 8.3 -- -- --Galaxy L07D guar 0.5 Gendrive 162 0.5 33.9 -- -- 94None -- Jaguar CP-13 1.00 6.6 13.9 10.0 --Jaguar 8600 0.5 Jaguar CP-13 0.50 16.0 23.9 13.0 106None -- High MW Cationic Guar (0083-40-3) 1.00 4.0 12.7 3.1 104K0341A 2 (WG-18) 0.5 0083-40-3 0.5 12.0 23.1 13.0 105None -- Percol 743 1.00 2.5 3.5 2.8 101WC-100 0.5 Percol 743 0.50 14.0 6.9 22.0 113Hercofloc 1129 0.5 Reten 157 0.50 15.4 3.2 8.9 101None -- 404-48-3 1.0 3.7AQU-D3129 0.5 404-48-3 0.5 14.3Jaguar 8707 0.5 Jaguar CP-13 0.5 21.3 48.0 19.4__________________________________________________________________________
EXAMPLE 2
Results on laboratory evaluation of strength properties, tensile stiffness and bending stiffness on handsheets prepared as in Example 1 are presented in Table 2. Pulp system employed in Set No. 1 is 50/50 recycled/northern softwood bleached kraft pulp. In Set No. 2, the pulp is 100 percent bleached kraft. The process to prepare the guars is similar to what has been explained in Example 1, except that the anionic guar was a carboxymethyl guar (available from Aqualon under the designation AQU-D3129) having a DS of 0.15 and the cationic guar (available from Aqualon under the designation 404-48-3) was a quaternary-modified guar, having a DS of 0.10.
TABLE 2__________________________________________________________________________ Tensile Bending Enhancement, % of Control Stiffness Stiffness Anionic Cationic Tensile Elonga- % of % ofNone Guar % Guar % Strength TEA tion control Control__________________________________________________________________________1 AQU-D3129 0.5 404-48-3 0.5 21.5 37.77 13.3 108 952 AQU-D3129 0.5 404-48-3 0.5 15.2 31.22 16.1 99 99__________________________________________________________________________
EXAMPLE 3
Laboratory evaluation results of strength properties and bending stiffness on handsheets prepared with 70/30 northern softwood/CTMP (Nos. 1 and 2) and recycled pulps (Nos.3 to 5) are shown in Table 3. The anionic additive is added to the pulp prior to adding the cationic additive. The guar additives Galaxy 707D and Gendrive 162 are the same as those used in Example 1. Kymene® 557H is the reaction product of an polyamide and epichlorohydrin conventionally used as a wet strength resin in paper and available from Hercules Incorporated. KN9-56CMG is a carboxymethyl guar. The combinations show minimal adverse effects on paper softness caused by the presence of the wet strength agent, as indicated by the stiffness data.
TABLE 3__________________________________________________________________________ Bending Enhancement, % of Control Stiffness Anionic Cationic Kymene 557H Dry % ofNo Additive Percent Additive Percent Percent Tensile Elongation TEA Control__________________________________________________________________________1 None -- None -- 1.0 10.8 10.0 -- 952 KN9-56CMG 0.15 Gendrive 162 0.15 0.75 18.3 13.9 1083 None -- None -- 1.0 11.9 22.2 20.6 --4 None -- Gendrive 162 0.5 0.5 19.6 25.9 34.4 --5 Galaxy 707D 0.25 Gendrive 162 0.25 0.5 34.5 33.2 77.6 104__________________________________________________________________________
COMPARATIVE EXAMPLE 4
Results of the evaluation of strength on handsheets prepared with unbleached kraft containing about 2 percent black liquor are shown in Table 4. The results show that a combination of an anionic and a cationic guar additive is not more effective than the cationic guar additive alone when added at the same total level. The guar additives, Galaxy 707D and Gendrive 162, are the same as used in Example 1.
TABLE 4__________________________________________________________________________ Enhancement, % of ControlAnionic Cationic TensileAdditive Percent Additive Percent Strength TEA Elongation__________________________________________________________________________Galaxy 707D 0.50 Gendrive 162 0.5 14.2 21.1 12.5None -- Gendrive 162 1.0 16.9 25.3 12.5__________________________________________________________________________
COMPARATIVE EXAMPLE 5
Results of strength properties evaluation on handsheets prepared with partially unbleached kraft incorporated externally with 0.9% black liquor are presented in Table 5. The results show that a combination of an anionic and a cationic guar, when added to this unbleached kraft-black liquor system, is in fact less effective than the cationic guar alone at the same total addition level. The guar additives are the same as those used in Example 1.
TABLE 5__________________________________________________________________________ TensileAnionic Cationic Strength TEA ElongationAdditive Percent Additive Percent (PSI) (ft. lb/ft.sup.2) (%)__________________________________________________________________________Control -- -- -- 5877 5.29 2.2Galaxy 707D 0.5 Gendrive 162 0.5 7644 7.58 2.6None -- Gendrive 162 1.0 8684 10.62 3.0__________________________________________________________________________
EXAMPLE 6
This series of tests examines the strength properties and bending stiffness of paper prepared in a small-scale pilot plant version of a conventional paper machine, located at Kalamazoo, Mich. and referred to herein as the Laboratory Former. The pulps used in the numbered tests were: Nos. 1 and 2, 50/50 NSW/NHW kraft; Nos. 3, 4, 7 and 8, 70/30 long fiber/sawdust; and Nos. 1 and 2, 70/30 virgin fiber/broke. In each case, a combination of an anionic and a cationic additive (guar or acrylamide copolymer) was incorporated in the pulp followed by the same amount of wet strength resin Kymene 557H. The anionic components used were all carboxymethyl guars. Among the cationic additives, Percol 743 is a polyacrylamide copolymer, the rest are guars. These results, recorded after 2 weeks natural curing and presented in Table 6, represent the enhancements of properties over what are obtained with 1 percent Kymene 557H alone. They demonstrate the fact that these combinations of an anionic and a cationic component provide synergistic effects on wet strength as well as dry strength of paper. These effects are significantly greater when one of the components is a conventional wet strength resin, such as Kymene 557H.
TABLE 6__________________________________________________________________________ Enhancement over Bending Total Control Containing Stiffness Kymene Additive 1% Kymene 557H % of 1% Anionic Cationic 557H Level Dry Wet KymeneNo Additive % Additive % % % Tensile Elongation TEA Tensile Control__________________________________________________________________________1 WG-18 0.30 Percol 743 0.20 0.50 1.00 20.3 19.5 42.5 17.8 992 Galaxy 707D 0.30 Gendrive 162 0.20 0.50 1.00 18.0 24.2 45.3 10.7 9.63 0087-08-2 0.30 Gendrive 162 0.20 0.50 1.00 26.2 28.2 62.2 31.9 1094 0087-08-2 0.30 Percol 743 0.20 0.50 1.00 26.3 32.2 63.1 40.5 995 0087-08-2 0.30 Percol 743 0.20 0.50 1.00 20.5 26.8 57.1 17.5 996 WG-18 0.30 0083-40-3 0.20 0.50 1.00 15.4 18.5 36.8 11.3 1077 D-3129 0.30 Percol 743 0.20 0.50 1.00 25.0 22.0 52.0 36.8 1048 WG-18 0.30 0083-40-3 0.20 0.50 1.00 19.3 27.3 62.0 29.2 98__________________________________________________________________________
EXAMPLE 7
This series of tests examines the strength properties and bending stiffness on handsheets prepared in the Laboratory Former. The pulps used in the numbered tests were: Nos. 1 to 6, 55/30/15 northern softwood/CTMP/recycled pulp, and No. 7, 50/50 northern softwood/hardwood furnish. The results in No 8 were produced from handsheets using 70/30 northern softwood/CTMP pulp. All the cationic additives were modified polyacrylamides. Percol 743 is a copolymer of acrylamide and 10 mole % MTMAC (Methylacryloxytrimethyl ammonium chloride), Reten 157 contains 10 mole % ATMAC (acryloxytrimethyl ammonium chloride) and Hercofloc 1154 contains 6 mole % DADMAC (dialcryloxydimethyl ammonium chloride). All the anionic additives are guar products available from Aqualon. The results are recorded in Table 7.
TABLE 7__________________________________________________________________________POLYACRYLAMIDE COPOLYMER - GUAR COMBINATIONS Bending Enhancement, % of Control Stiffness Anionic Cationic Tensile % ofNo Additive Percent Additive Percent Strength Elongation TEA Control__________________________________________________________________________1 None -- Percol 743 1.00 6.4 15.0 22.6 --2 K0341 A2 WG-18) 0.50 Percol 743 0.50 17.8 12.9 36.3 --3 None -- Reten 157 1.0 5.3 11.7 14.6 --4 AQU-D3129 0.50 Reten 157 0.5 12.7 19.5 35.3 --5 None -- Hercofloc 1154 1.0 11.7 10.0 21.1 --6 AQU-D3129 0.50 Hercofloc 1154 0.50 16.9 22.8 44.2 --7 AQU-D3129 0.50 Percol 743 0.50 37.5 45.5 101 1068 Galaxy 707D 0.50 Hercofloc 1154 0.50 16.3 8.0 26.4 92__________________________________________________________________________
EXAMPLE 8
This series of tests examines the strength properties and bending stiffness of paper prepared in the Kalamazoo Laboratory Former with 70/30 northern softwood/CTMP furnish. The anionic component was added first followed by the cationic component, and the wet strength resin (Kymene 557H) was added last. The results, recorded in Table 8, show that the combination of a wet strength resin and an anionic and a cationic guar, and even the combination of a an anionic guar and a wet strength resin enhances not only the dry strength but also the wet strength very significantly over the corresponding properties obtained by the same amount of the wet strength resin alone. The bending stiffness of the paper samples not adversely affected by the presence of these additive combinations. The additives AQU-D 3129, Galaxy 707D and 0.1 DSCMG are anionic carboxymethyl guars. 404-48-3, 404-48-1 and Gendrive 162 are Aqualon cationic guars of which the first two are developmental. The respective controls used were made with the same furnish, but with no additive.
TABLE 8__________________________________________________________________________ Total Enhancement, % of Control Bending Kymene Additive Wet Stiffness Anionic Cationic 557H Level Dry Tensile % ofNo Additive % Additive % % % Tensile Elonation TEA (P/I) Control__________________________________________________________________________1 None -- None -- 1.00 1.00 9.1 3.4 13.0 5.65 1132 None -- None -- 1.50 1.50 -- 9.9 15.5 5.85 1303 None -- None -- 2.00 2.00 11.9 13.0 37.0 5.93 --4 AQU-D3129 0.13 404-48-3 0.13 1.00 1.26 17.5 24.0 52.3 6.44 885 Galaxy 707D 0.25 404-48-1 0.25 1.00 1.50 16.3 20.0 37.0 6.58 916 0.1 DSCMG 0.19 404-48-1 0.19 1.50 1.88 28.2 4.3 29.8 7.14 --7 0.1 DSCMG 0.50 Gendrive 162 0.50 1.00 2.00 33.4 8.9 38.9 7.15 898 0.1 DSCMG 1.00 None -- 1.00 2.00 32.6 9.8 30.9 7.67 --__________________________________________________________________________
EXAMPLE 9
This series of tests examines the strength properties and bending stiffness of handsheets prepared from the following pulps: Nos. 1 to 4, 50/50 softwood/hardwood kraft (SWK/HWK); (Nos. 5 and 6), 70/30 northern softwood kraft/CTMP (NSK/CTMP). AQU-D3129 and Galaxy 707D are anionic carboxymethyl guars previously referred to, and Gendrive 162 is a cationic guar previously referred to, while 404-48-3 is a developmental cationic guar. The results, which are recorded in Table 9, show that the paper properties obtained by adding to the pulp coacervates formed by premixing the anionic and cationic components are about the same as those obtained by adding the additives individually to the pulp. They were significantly more convenient to use.
TABLE 9__________________________________________________________________________ Enhancement over Control Containing Bending 1% Kymene 557H Stiffness Anionic Cationic Modes of Addition Tensile % ofNo Additive % Additive % to Pulp System Strength Elongation TEA Control__________________________________________________________________________1 AQU-D3129 0.5 404-48-3 0.5 Added individually in pulp 12.2 12.5 11.6 1022 AQU-D3129 0.5 404-48-3 0.5 Premixed to form 12.8 8.3 21.7 107 coacervate before adding to pulp3 AQU-D3129 1.0 404-48-3 1.0 Added individually 28.5 25.0 45.0 1084 AQU-D3129 1.0 404-48-3 1.0 Premixed to form 25.6 29.2 49.8 110 coacervate5 Galaxy 707D 0.5 Gendrive 162 0.5 Added individually to pulp 17.8 6.5 28.5 916 Galaxy 707D 0.5 Gendrive 162 0.5 Premixed to form 17.4 9.7 29.3 95 coacervate before adding to pulp__________________________________________________________________________
EXAMPLE 10
Dry strength properties and bending stiffness of paper prepared in the Kalamazoo Laboratory Former (KLF) with 55/30/15 NSK/CTMP/secondary furnish are presented in Table 10. The dam recorded in K-17803 and K-17822 represent enhancement of dry strength properties over what was obtained with the control with no additive. The anionic additive employed are CMG (AQU-D3129, Galaxy 707D) and CMHPG (WG-18) while the cationic components are cationic guars (Jaguar CP-13-HiTek, and 0083-40-3) and acrylamide copolymer (Percol 743). The results show that in most cases, at the same level of addition, dry strength with a combination of an anionic and a cationic guar (or a cationic polyacrylamide) is significantly higher than what is obtained with a combination of an anionic guar and the wet strength resin Kymene 557H, with less adverse effect of paper softness, as indicated by the bending stiffness results.
TABLE 10__________________________________________________________________________ Bending Kymene Total Enhancement, StiffnessAnionic Cationic 557H Additive % of Control % ofAdditive Percent Additive Percent Percent Level % Tensile TEA Elongation Control__________________________________________________________________________AQU-D3129 0.50 Jaguar CP-13 0.50 None 1.00 43.3 76.0 29.0 87WG-18 0.50 Percol 743 0.50 None 1.00 32.9 63.2 27.8 89WG-18 0.50 0083-40-3 0.50 None 1.00 26.9 47.0 19.5 108AQU-D3129 0.50 None -- 0.50 1.00 23.5 54.2 23.9 112WG-18 0.50 None -- 0.50 1.00 9.3 28.0 18.0 110Galaxy 707D 0.50 None -- 0.50 1.00 25.7 57.0 23.9 118__________________________________________________________________________
EXAMPLE 11
Dry strength properties and bending stiffness of paper prepared in the KLF using 70/30 NSK/CTMP furnish are recorded in Table 11. The data demonstrated enhancement of dry strength properties over what was obtained with the control containing no additive. The anionic additives are CMG and cationic components are either cationic guar or Kymene 157H, a wet strength resin. The results show that in most cases, at the same level of addition, a combination of an anionic and a cationic guar provides significantly higher dry strength than what is obtained with the combination of an anionic guar and Kymene, with less adverse effect on paper softness.
TABLE 11__________________________________________________________________________ Bending Kymene Total Enhancement, StiffnessAnionic Cationic 557H Additive % of Control % ofAdditive Percent Additive Percent Percent Level % Tensile TEA Elongation Control__________________________________________________________________________AQU-D3129 0.50 404-48-1 0.50 None 1.00 34.8 53.7 25.7 95AQU-D3129 0.60 404-48-3 0.40 None 1.00 25.6 45.9 21.0 92AQU-D3129 0.50 404-48-3 0.50 None 1.00 25.9 96.6 51.2 96AQU-D3129 0.50 None -- 0.50 1.00 18.4 26.7 9.8 110Galaxy 707D 0.50 None -- 1.0 1.50 26.5 51.5 22.8 1160.1 DS CMG 1.0 None -- 1.0 2.00 22.5 30.9 9.2 --__________________________________________________________________________
COMPARATIVE EXAMPLE 12
Strength properties and bending stiffness of paper prepared at the Kalamazoo Laboratory Former with 70/30 NSW/CTMP are presented in Table 12. The results demonstrate enhancement of dry strength properties over what was obtained with the control with no additive while the wet strength tensile is the enhancement over what was obtained with 0.5% Kymene® alone. To demonstrate the advantages achieved by the combinations of anionic and cationic components according to the invention over the prior art combinations described in U.S. Pat. No. 3,058,873, the anionic additives used according to the invention were CMG and CMHPG, while CMC-6CTL is a technical grade carboxymethyl cellulose such that disclosed in the Patent. Gendrive 162 is a cationic guar and Reten® 157 is an acrylamide copolymer. A sharp drop in dry strength accompanied by an increase in bending stiffness was noted whe the carboxymethyl cellulose was used.
TABLE 12__________________________________________________________________________ Kymene Wet Strength BendingRun Anionic Cationic 557H Enhancement, % of Control Enhancement StiffnessNo. Additive Percent Additive Percent Percent Tensile TEA Elongation % 0.5 Kymene % of__________________________________________________________________________ Control1 Galaxy 707D 0.30 Gendrive 162 0.20 0.50 31.0 102 33.6 24.5 --2 Galaxy 707D 0.50 None -- 0.50 27.6 68 30.6 27.0 --3 WG-18 0.20 Reten 157 0.30 0.50 30.8 76 -- -- 964 WG-18 0.50 None -- 0.50 22.4 60 37.3 25.7 94 5* CMC-6CTL 0.50 None -- 0.50 13.5 21 13.1 12.0 99__________________________________________________________________________ *See US Patnet 3,058,873 described above.
TESTS OF ADDITIVES FOR EXAMPLES
Results of viscosity and relative specific viscosity (RSV) for 0.25% aqueous solutions of the guar additives are shown in Table 13. The results indicate the range of relative molecular weights of typical additives employed in the examples. Since these data do not lead to the absolute molecular weights of the additives, no comparison can be made with similar data for materials of different molecular shapes. Charge densities of typical additives employed in the examples are shown in Table 14.
TABLE 13______________________________________Additives Viscosity (CP) RSV (dl/g)______________________________________Guar Gendrive 162 31.1 121.5Guar Galaxy 707D 9.0 32.4Guar Jaguar CP-13 66.5 223.8______________________________________
TABLE 14______________________________________ Charge Density Viscosity (cp)Product (meq/g) 2% Solution______________________________________AQU-D3129 -1.34 2,300404-48-3 0.86 4,200Jaguar 8707 -0.012 12,000Jaguar LP-13 0.23 23,000______________________________________
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A process for making paper to enhance the dry strength of the paper produced without substantially reducing its softness comprising adding to a bleached pulp furnish, separately or together, (1) an anionic polymer selected from the group consisting of carboxymethyl guar, carboxymethyl bean gum, carboxymethyl hydroxyethyl guar, and a carboxymethyl hydroxypropyl guar, with (2) a cationic polymer selected from the group consisting of a cationic guar, a cationic acrylamide copolymer, a cationic bean gum, a cationic amineepichlorohydrin wet strength resin, and both a cationic wet strength resin and at least one of the other said cationic polymers, a composition for adding to a paper-making pulp slurry comprising the said polymers, a method for making the said composition, and a paper product containing the said composition, are disclosed.
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TECHNICAL FIELD
[0001] The present invention relates generally to the coupling of fluid flow components. More particularly, the present invention relates to polymeric fittings for coupling polymeric fluid flow tubing. Embodiments of the present invention relate especially to polymeric fittings for coupling concentric inner and outer polymeric tubes, containment systems including the same, and associated methods.
BACKGROUND
[0002] Numerous industries utilize fitting arrangements in many applications to compressively seal the ends of non-threaded tubing. In particular, fitting arrangements of this type are used extensively in the semiconductor processing industry, where plastic tubes are used to confine dangerous fluids including, for example, fluids that are corrosive, highly acidic, at a high temperature, and/or under significant pressure. In applications such as semiconductor processing, the fluids involved react with and/or may be contaminated by the use of metallic components and conventional fittings. Thus, in such industries, plumbing components are often made of highly inert materials such as fluoropolymers (e.g., PFA and PTFE) for wetted components.
[0003] Containment integrity becomes critical in processes using caustic and dangerous fluids. Under such conditions, the use of concentric tubing is well known. In a concentric tube arrangement, outer tubing surrounds a given length of inner tubing that may be transporting fluid. This arrangement may provide containment from internal leaks and/or protection against external damage. The outer tube may additionally carry heated or cooled fluids used to heat or cool the fluids flowing through the inner tube. Thus, it is desirable under these types of settings to use fitting arrangements with the ability to seal concentric inner and outer plastic tubing against leaks.
[0004] One conventional fitting for sealing concentric inner and outer plastic tubes, is disclosed in U.S. Pat. No. 5,498,036 to Kingsford. Specifically, the Kingsford fitting comprises concentric tubes and three additional members: an annular fitting body, an intermediate annular body, and an annular nut. The annular fitting body has a circular bore extending therethrough, a cylindrical nose portion on one end, and external threads. The intermediate annular body has a circular bore extending therethrough, a cylindrical nose portion on one end, a collar on the opposing end, and both internal and external threads. The annular nut has a circular bore extending therethrough, a shoulder on one end, and internal threads. The inner tube may be compressively engaged between the cylindrical nose portion of the annular fitting body and the collar of the intermediate annular body when the annular fitting body is threaded into the intermediate annular body. Similarly, the outer tube may be compressively engaged between the cylindrical nose portion of the intermediate annular body and the shoulder of the annular nut when the intermediate annular body is threaded into the annular nut. Thus, both the inner and outer tubes are sealed in one fitting.
[0005] Double containment fittings like the one described above, that feature multiple threading engagements, possess some inherent problems. Fluoropolymers are relatively soft materials. The softness of the material makes it difficult to hold tolerances and shape while machining. In addition, the material's high coefficient of thermal expansion prohibits high-speed machining due to frictionally induced heating and expansion of the material. Thus, additional thread cutting passes add significantly to the time required to machine a single fitting unit. The probability that a flaw in a threaded engagement will cause a hazardous leak is also increased with each additional threaded engagement. Every threaded connection has a potential to leak, thus, the more threaded connections there are in a containment system, the greater the probability that there will be a leak.
[0006] As may be appreciated, it would be advantageous to provide a fitting arrangement for jointly sealing concentric inner and outer plastic tubing with minimal use of threaded couplings.
BRIEF SUMMARY OF THE INVENTION
[0007] Embodiments of the invention relate to a double containment fitting for the ends of concentric tubing, systems including the same, methods of sealing the end of concentric tubing, and methods of making a double containment fitting.
[0008] According to one embodiment of the invention, a double containment fitting for joining to the ends of concentric inner and outer tubes comprises an annular body with a first end portion, a second, opposing end portion, and a bore therethrough, wherein a portion of an outside surface of the second end portion includes threads thereon, an inner nose with a first end portion, a second, opposing end portion, and a bore therethrough, wherein the first end portion is configured to be receivable by the bore of the annular body, an outer nose with a first end portion, a second, opposing end portion, and a bore therethrough, wherein the bore of the outer nose is configured to telescopically receive the inner tube and the first end portion of the outer nose is configured to be receivable by the bore of the annular body, and an annular nut having a first end portion, a second, opposing end portion, and a bore therethrough, wherein the bore is configured to receive a portion of the concentric inner and outer tubes with the second end portion of the outer nose positioned between the concentric inner and outer tubes, and wherein at least a portion of a surface defining the bore includes threads thereon, and the threads of the annular nut are configured to engage with the threads of the annular body.
[0009] Another embodiment of the present invention comprises a method for joining the ends of concentric inner and outer tubes to a fitting, the method comprising compressing a flared end of the inner tube between an inner nose and an outer nose, compressing a flared end of the outer tube between the outer nose and an annular nut, and threading the annular nut to an annular body, with the inner and outer tubes and the inner and outer noses positioned therebetween.
[0010] Still another embodiment of the present invention comprises a method of forming a kit for a double containment fitting, including molding an inner nose comprising a first end portion, a second end portion, and a bore therethrough, molding an outer nose comprising a first end portion, a second end portion, and a bore therethrough, molding an annular body comprising a first end portion, a second end portion, a bore therethrough, and at least one flexible wall section positioned between the first end portion and the second end portion, wherein the bore is configured to receive the first end portion of the inner nose and the first end portion of the outer nose, and molding an annular nut configured to couple with the annular body.
[0011] Yet another embodiment of the present invention comprises a double containment system including an outer tube having a flared end, an inner tube extending through the outer tube and having a flared end, and a double containment fitting closing the flared end of the outer tube and joining the flared end of the inner tube in fluid communication with a passageway therethrough, the double containment fitting comprising: an annular body with a first end portion, a second, opposing end portion, and a bore therethrough, wherein a portion of an outside surface of the second end portion includes threads thereon; an inner nose with a first end portion, a second, opposing end portion, and a bore therethrough, wherein the first end portion is configured to be receivable by the bore of the annular body; an outer nose with a first end portion, a second, opposing end portion, and a bore therethrough, wherein the bore of the outer nose is configured to telescopically receive the inner tube and the first end portion of the outer nose is configured to be receivable by the bore of the annular body; and an annular nut having a first end portion, a second, opposing end portion, and a bore therethrough, wherein the bore is configured to receive a portion of the concentric inner and outer tubes with the second end portion of the outer nose positioned between the concentric inner and outer tubes, and wherein at least a portion of a surface defining the bore includes threads thereon, and the threads of the annular nut are configured to engage with the threads of the annular body.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] 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 in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0013] FIG. 1A shows an exploded cross-sectional view of an embodiment of a double containment fitting of the present invention;
[0014] FIG. 1B depicts a cross-sectional view of an embodiment of an annular body of the present invention;
[0015] FIG. 1C depicts a side view of the annular body of FIG. 1B ;
[0016] FIG. 1D depicts a cross-sectional view of an embodiment of an annular nut of the present invention;
[0017] FIGS. 2-4 show cross-sectional views of the double containment fitting of FIG. 1A in partially assembled states;
[0018] FIG. 5 shows a cross-sectional view of the double containment fitting of FIG. 1A in an assembled state;
[0019] FIG. 6 shows a cross-sectional view of an embodiment of an annular body of the present invention;
[0020] FIG. 7 shows a cross-sectional view of another embodiment of an annular body of the present invention; and
[0021] FIG. 8 is a simplified sketch used to illustrate embodiment of methods of the present invention for making and/or assembling a double containment fitting.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring in general to the accompanying drawings, various aspects of the present invention are illustrated in the context of embodiments of a fitting and methods for assembling such a fitting with concentric tubes. Common elements of the illustrated embodiments are designated with like reference numerals. It should be understood that the figures presented are not meant to illustrate actual views of any particular portion of a particular fitting, but are merely idealized schematic representations which are employed to more clearly and fully depict the invention.
[0023] FIG. 1 depicts an exploded cross-sectional view of a first embodiment of a double containment fitting of the present invention. The fitting 1 may be used with concentric tubing 10 . The concentric tubing 10 may include an inner tube 12 and an outer tube 16 . The inner tube 12 may be at least partially received within the outer tube 16 . The inner tube 12 may have a flared end 13 , and the outer tube may have a flared end 17 . The concentric tubing 10 may be used for transporting fluids. The double containment fitting 1 enables the flared ends 13 , 17 of either or both the inner tube 12 and outer tube 16 to be engaged and/or sealed within the double containment fitting 1 . The flared end 17 of the outer tube 16 may be closed from fluid communication in the double containment fitting 1 , and a passageway 14 through the inner tube 12 may be in fluid communication with an opening 2 of the double containment fitting 1 .
[0024] The double containment fitting 1 includes an annular body 20 , an inner nose 30 , an outer nose 40 , and an annular nut 50 . FIG. 5 shows the double containment fitting 1 and the concentric tubing 10 in an assembled state. As shown in FIG. 5 , the inner nose 30 may be at least partially inserted within the flared end 13 of the inner tube 12 , and the outer nose 40 may encircle a section of the inner tube 12 and be partially inserted within the flared end 17 of the outer tube 16 in the assembled state. The inner nose 30 , the inner tube 12 , the outer nose 40 , and the outer tube 16 may be at least partially telescopically positioned within the annular nut 50 in the assembled state. The annular nut 50 and the annular body 20 may be joined with a threaded connection. In other embodiments, the annular nut 50 and the annular body 20 may be joined with a snap-fit (or other mechanical interference connection), using an adhesive, or by forming a direct bond between the annular nut 50 and the annular body 20 (e.g., using a thermal bonding process or an ultrasonic bonding process).
[0025] The inner tube 12 , outer tube 16 , annular body 20 , inner nose 30 , outer nose 40 , and annular nut 50 may be formed of any material possessing good chemical and thermal resistance and capable of accommodating the types of fluids, pressures, temperatures, etc. to which the double containment fitting 1 may be exposed. Suitable materials include, but are not limited to, polymeric materials. As a nonlimiting example, these components may be formed from fluoromer materials such as, for example, tetrafluoroethylene (TFE), polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene (FEP), perfluoroalkoxy fluorocarbon resin (PFA), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrafuoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). Many other polymer materials also may be used including, for example, polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene, polyethelyne, high density polyethylene, acrylonitrile butadiene styrene (ABS), a thermal setting plastic, a thermal plastic, or a plastic with property enhancing additives.
[0026] The inner tube 12 , outer tube 16 , annular body 20 , inner nose 30 , outer nose 40 , and annular nut 50 may be formed using, for example, a molding process (e.g., compression molding, injection molding, transfer molding, etc.). Optionally, features such as threads may be added to molded parts using machining processes (e.g., turning, milling, and drilling), which may comprise computer numerical control (CNC) processes. FIG. 8 depicts a method of making the components of the double containment fitting 1 . The components may be molded (act 100 ) and then threads 24 , 54 by be formed in the annular nut 50 and the annular body 50 (act 110 ).
[0027] FIG. 1B is an enlarged cross-sectional view of the annular body 20 shown in FIG. 1A . The annular body 20 may include a first end 21 , an opposing second end 22 , and a bore 23 that extends through the annular body between the first end 21 and the second end 22 . The annular body 20 may be configured to at least partially telescopically receive the inner nose 30 , the flared end 13 of the inner tube 12 , and the outer nose 40 .
[0028] The bore 23 of the annular body 20 comprises multiple portions. A first end portion 23 a is configured to receive the outer nose 40 and may include an annular groove 26 for mating with an annular lip 44 (see FIG. 2 ) of the outer nose 40 and forming a fluid-tight seal therebetween. A second portion 23 b of the bore 23 has a diameter d b smaller than a diameter d a of the first end portion 23 a . The diameter d b of the second portion 23 b of the bore 23 may be smaller than the outside diameter of the outer nose 40 . Thus, the outer nose 40 may not be inserted within the bore 23 beyond the first portion 23 a.
[0029] A third portion 23 c of the bore 23 may be defined by a flexible wall 27 of the annular body 20 . The length l c the third portion 23 c of the bore 23 may change as forces are applied to the annular body 20 during assembly of the double containment fitting 1 , as further described hereinbelow. The diameter d c of the third portion 23 c of the bore 23 may change along the length l c of the third portion 23 c . The inner surface of the annular body 20 in the third portion 23 c may thus have a tapered profile, as shown in FIG. 1B . The flexible wall 27 may be thinner than other walls of the annular body 20 to enable the flexible wall 27 to deform under longitudinal tension on the annular body 20 . The outside surface 29 of the annular body 20 may fold radially inwardly at the flexible wall 27 , then folds radially outwardly again to meet the threads 24 of the annular body 20 . In other words, the portion of the annular body 20 that defines the third portion 23 C of the bore 23 may comprise one or more bends, folds, or flutes 28 to facilitate deformation (e.g., flexing) thereof.
[0030] A fourth portion 23 d of the bore 23 may be configured to receive a first end portion 31 of the inner nose 30 . The fourth portion 23 d of the bore 23 may include an annular groove 25 for mating with an annular lip 34 (see FIG. 2 ) of the inner nose 30 and forming a fluid-tight seal therebetween. A fifth portion 23 e of the bore 23 may have a diameter d e smaller than a diameter d d of the fourth portion 23 d . The diameter d e of the fifth portion 23 e of the bore 23 may be smaller than the outside diameter of the inner nose 30 . Thus, the inner nose 30 may not be inserted within the bore 23 beyond the fourth portion 23 d.
[0031] FIG. 1C depicts a side view of the annular body 20 . The annular body 20 may include one or more flat surfaces 29 (which, optionally, may define a hexagonal outer profile) configured to enable a tool (e.g., a wrench) to be used to provide relative rotation between the annular body 20 and the annular nut 50 ( FIG. 1 ). The first end 21 of the annular body 20 may be configured for coupling to an external component (not shown). An outside surface 3 of the second end 22 of the annular body 20 may include threads 24 thereon that are configured to engage with complementary threads 54 on the annular nut 50 ( FIG. 1 ).
[0032] Returning to FIG. 1 , the inner nose 30 comprises a first end portion 31 , an opposing second end portion 32 , and a bore 33 extending through the inner nose 30 between the first end portion 31 and the second end portion 32 . The first end portion 31 of the inner nose 30 may have an outside diameter larger than an outside diameter of the opposing second end portion 32 of the inner nose 30 . The bore 33 may have a substantially uniform diameter therethrough. The first end portion 31 of the inner nose 30 is configured to be received within the bore 23 of the annular body 20 . The opposing, second end portion 32 of the inner nose 30 may be inserted into the flared end 13 of the inner tube 12 . The first end portion 31 of the inner nose 30 , having a larger outside diameter than both the opposing, second end portion 32 , and the inside diameter of the flared end 13 of the inner tube 12 may prevent the inner nose 30 from being inserted too far longitudinally into the flared end 13 of the inner tube 12 . The diameter of the passageway 14 extending through the inner tube 12 may be substantially similar to the diameter of the bore 33 extending through the inner nose 30 . Thus, there is an at least substantially continuous fluid flow passage extending through the inner nose 30 and the inner tube 12 when the second end portion 32 of the inner nose 30 is inserted into the flared end 13 of the inner tube 12 .
[0033] The outer nose 40 may comprise a first end portion 41 , an opposing, second end portion 42 , and a bore 43 extending through the outer nose 40 between the first end portion 41 and the second end portion 42 . The first end portion 41 of the outer nose 40 is configured to be received within the bore 23 of the annular body 20 . In the assembled state ( FIG. 5 ), the outer nose 40 may at least partially encircle the second end portion 32 of the inner nose 30 , and the flared end 13 of the inner tube 12 may be disposed between the first end portion 41 of the outer nose 40 and the second end portion 32 of the inner nose 30 . The bore 43 within the first end portion 41 of the outer nose 40 may have a diameter larger than the diameter of the bore 43 within the opposing, second end portion 42 of the outer nose 40 . The flared end 13 of the inner tube 12 may be received by the bore 43 within the first end portion 41 of the outer nose 40 . The flared end 13 of the inner tube 12 may have a larger outside diameter than the bore 43 within the opposing, second end portion 42 of the outer nose 40 . Thus, the outer nose 40 may be prevented from traveling longitudinally beyond the flared end 13 of the inner tube 12 . The opposing, second end portion 42 of the outer nose 40 may be configured to be at least partially received by the flared end 17 of the outer tube 16 .
[0034] The annular nut 50 may at least partially telescopically receive the outer tube 16 , which in turn at least partially receives the outer nose 40 and the inner tube 12 . The second end portion 32 of the inner nose 30 may be at least partially telescopically received by the inner tube 12 , and the first end portion 31 of the inner nose 30 may be at least partially telescopically received by the annular body 20 . The annular nut 50 may engage with the annular body 20 to seal the double containment fitting. The annular nut 50 may include a first end 51 , an opposing second end 52 , and a bore 53 extending through the annular nut 50 between the first end 51 and the second end 52 .
[0035] FIG. 1D is an enlarged cross-sectional view of the annular nut 50 . The bore 53 of the annular nut 50 may be defined by an inside surface 56 of the annular nut 50 . A portion of the inside surface 56 may include threads 54 complementary to, and configured to engage with, the threads 24 of the annular body 20 .
[0036] The bore 53 of the annular nut 50 may include multiple portions or sections. A first portion 53 a of the bore 53 is configured to telescopically receive the outer tube 16 , but the diameter d 53a of the first portion 53 a of the bore 53 is too small to receive the flared end 17 of the outer tube 16 . The annular nut 50 may, in some embodiments, comprise an annular gripper 60 , which may be inserted into the second portion 53 b of the bore 53 , and which is described in further detail hereinbelow. A third portion 53 c of the bore 53 may be configured to telescopically receive the flared end 17 of the outer tube 16 . A fourth portion 53 d of the bore 53 may be defined by or comprise the threads 54 on the inside surface 56 of the annular nut 50 .
[0037] An annular gripper 60 may be positioned within the bore 53 of the annular nut 50 . The annular gripper 60 may be configured to grip an outer surface of the outer tube 16 . The annular gripper 60 may be or comprise a ring (e.g., a split ring), and may comprise a softer material than the material of the annular nut 50 . The softer material of the annular gripper 60 may more readily conform to the surface of the outer tube 16 . The annular gripper 60 may be positioned in the second portion 53 b of the bore 53 of the annular nut 50 , between the third portion 53 c and the first portion 53 a . The diameters of the second portion 53 b and the third portion 53 c may be larger than the diameter of the first portion 53 a . Thus, the gripper 60 may contact a longitudinally facing inner wall 55 of the annular nut 50 .
[0038] A manner in which the double containment fitting 1 may be assembled with the inner tube 12 and the outer tube 16 is described below with reference to FIGS. 2-4 , each of which depicts the double containment fitting 1 , the inner tube 12 , and the outer tube 16 in a partially assembled state.
[0039] Referring to FIG. 2 , the second end portion 32 of the inner nose 30 may be inserted into the flared end 13 of the inner tube 12 , and the first end portion 31 of the inner nose 30 may be inserted into the bore 23 of the annular body 20 . The second end portion 42 of the outer nose 40 may be inserted into the flared end 17 of the outer tube 16 , and the first end portion 41 of the outer nose 40 may be inserted into the bore 23 of the annular body 20 and positioned over the flared end 13 of the inner tube 12 and the second end portion 32 of the inner nose 30 . The annular nut 50 may be positioned over the outer tube 16 , and the first end 51 of the annular nut 50 may be positioned over the flared end 17 of the outer tube 16 .
[0040] Turning to FIG. 3 , the annular nut 50 may be threaded onto the annular body 20 . As the threads 54 of the annular nut 50 are threaded onto the threads 24 of the annular body 20 , the annular nut 50 will slide relative to and over the annular body 20 (i.e., in the leftward direction of FIG. 3 ). As the annular nut 50 will slide relative to and over the annular body 20 , the annular gripper 60 will abut against and grip the outer tube 16 at the junction between the flared end 17 and the body portion 18 of the outer tube 16 , thus retaining the outer tube 16 in the annular nut 50 .
[0041] Optionally, a surface of the annular gripper 60 may include a plurality of annular ridges (not shown), arranged in a stair-step manner to approximate the angle of a surface of the shoulder region of the outer tube 16 , between the flared end 17 and the body portion 18 . The plurality of annular ridges may seize the outer tube 16 shoulder surface, retaining the outer tube 16 in place within the annular nut 50 .
[0042] FIG. 3 depicts the threads 54 of the annular nut 50 partially engaged with the threads 24 of the annular body 20 . The body portion 18 of the outer tube 16 is received by the first portion 53 a of the bore 53 of the annular nut 50 with the flared portion 17 of the outer tube 16 in the third portion 53 c of the bore 53 of the annular nut 50 . The annular gripper 60 prevents the flared end 17 of the outer tube 16 from sliding through the bore 53 of the annular nut 50 . The second end 42 of the outer nose 40 is received by the flared end 17 of the outer tube 16 , and the inner tube 12 extends through the outer tube 16 and the bore 43 of the outer nose 40 . An end of an annular passageway 19 between an outside wall of the inner tube 12 and an inside wall of the outer tube 16 is sealed at the ends of the inner tube 12 and the outer tubes 16 by the outer nose 40 . The first end 31 of the inner nose 30 is received by the bore 23 of the second end 22 of the annular body 20 . The second end 32 of the inner nose 30 is received by the flared end 13 of the inner tube 12 . The inner tube 12 is telescopically received by the bore 43 of the outer nose 40 . The first end portion 41 of the outer nose 40 is received by the bore 23 of the second end 22 of the annular body 20 and the second end 42 of the outer nose 40 is received by the flared end 17 of the outer tube 16 . The outer tube 16 is telescopically received by the bore 53 of the annular nut 50 , and retained therein by the annular gripper 60 .
[0043] In FIG. 3 , the threads 54 of the annular nut 50 are shown engaged to the threads 24 of the annular body 20 . After the annular gripper 60 abuts against the flared end 17 of the outer tube 16 , as the annular nut 50 and annular body 20 are further threaded together, the inner nose 30 , the flared end 13 of the inner tube 12 , the outer nose 40 , and the flared end 17 of the outer tube 16 are longitudinally compressed together between the annular body 20 and the annular nut 50 .
[0044] Referring to FIG. 4 , threading the annular nut 50 and the annular body 20 further together (from the configuration of FIG. 3 ) will cause the second end portion 42 of the outer nose 40 to abut against the flared end 13 of the inner tube 12 , and, in turn, cause the flared end 13 of the inner tube 12 to abut against the second end portion 32 of the inner nose 30 . As the annular nut 50 is even further threaded onto the annular body, the first end portion 31 of the inner nose 30 is caused to be seated in the annular body 20 and to provide an interference fit between the annular lip 34 of the inner nose 30 and the complementary annular groove 25 of the fourth portion 23 d ( FIG. 1B ) of the bore 23 of the annular body 20 . FIG. 4 illustrates the double containment fitting 1 in this configuration, after the annular lip 34 of the inner nose 30 has been seated in the annular groove 25 of the annular body 20 .
[0045] FIG. 5 depicts the annular nut 50 and the annular body 20 in the fully engaged configuration. As can be seen by comparing FIG. 5 to FIG. 4 , further threading of the annular nut 50 onto the annular body 20 from the configuration of FIG. 4 will cause the flexible wall 27 of the annular body 20 to deform, which allows the second end 22 of the annular body 20 to move further toward and into the annular nut 50 , while the first end 21 of the annular body 20 is prevented from moving further toward the annular but 50 due to interference between the annular gripper 60 , the flared end 17 of the outer tube 16 , the outer nose 40 , the flared end 13 of the inner tube 12 , and the inner nose 30 . In other words, as the annular nut 50 is further threaded onto the annular body 20 , a tensile force may be applied to the annular body 20 , which may cause the flexible wall 27 to stretch in the longitudinal direction or to otherwise deform.
[0046] FIG. 1B illustrates the annular body 20 in a neutral configuration, with no external forces applied thereto. FIG. 6 illustrates a cut-away view of the annular body 20 under tension along a longitudinal axis of the annular body 20 , as would be the case in the fully engaged configuration (shown in FIG. 5 ) of the double containment fitting 1 . With the annular body 20 under tension, as shown in FIG. 6 , the length l c of the third portion 23 c ( FIG. 1B ) of the bore 23 through the annular body 20 may increase as the flexible wall 27 stretches or deforms. Thus, the length l c of the third portion 23 c of the bore 23 through the annular body 20 , and the length of the annular body 20 itself are greater when the annular body 20 is under tension than when no tensile forces are applied to the annular body 20 . The double containment fitting 1 is configured such that the annular body 20 is placed under tension as the components of the double containment fitting 1 are assembled together with the inner tube 12 and the outer tube 16 , and the annular nut 50 is threaded onto the annular body 20 , and the annular body 20 is configured such that at least a portion of the annular body 20 will deform when it is placed under tension.
[0047] Referring again to FIG. 5 , as the annular nut 50 is further threaded onto the annular body 20 , the flexible wall 27 deforms (e.g., elastically deforms), and the second end 22 of the annular body 20 moves further into the annular nut 50 until the first end portion 41 of the outer nose 40 is seated in the annular body 20 , and an interference fit is provided between the annular lip 44 of the outer nose 40 and the complementary annular groove 26 of the first portion 23 a ( FIG. 1B ) of the bore 23 of the annular body 20 . After an interference fit is provided between the annular lip 44 of the outer nose 40 and the complementary annular groove 26 of the annular body 20 , the double containment fitting 1 may be in the fully-engaged configuration with the inner tube 12 and the outer tube 16 . In other words, the annular body 20 , the inner nose 30 , the inner tube 12 , the outer nose 40 , the outer tube 16 , and the annular nut 50 may be configured such that, as the annular nut 50 is threaded onto the annular body 20 , the first end portion 41 of the outer nose 40 and the annular body 20 are the last parts to fully engage with one another. The biasing force of the flexible wall 27 of the annular body 20 , when flexed, enables the components of the double containment fitting 1 to be coupled in such a manner as to provide fluid tight seals therebetween, yet the biasing force is not strong enough to strip the complementary threads 24 , 54 of the annular body 20 and the annular nut 50 , respectively.
[0048] In the fully engaged configuration shown in FIG. 5 , the outer nose 40 provides a seal between the inner tube 12 and the outer tube 16 , and seals the passageway 19 from the exterior of the outer tube 16 and the interior of the inner tube 12 . Similarly, the inner nose 30 provides a seal between the inner tube 12 and the annular body 20 , and seals the passageway 14 from the exterior of the inner tube 12 . The passageway 14 of the inner tube 12 is in fluid communication with the bore 33 of the inner nose 30 and the bore 23 of the annular body 20 .
[0049] The annular nut 50 and the annular gripper 60 engage the flared end 17 of the outer tube 16 , and force the outer tube 16 toward the outer nose 40 . The outer nose 40 engages the flared end 13 of the inner tube 12 , and forces the inner tube 12 toward the inner nose 30 . The first end portion 41 of the outer nose 40 engages with the annular body 20 , which forces the outer nose 40 back against the outer tube 16 , such that the flared end 17 of the outer tube 16 is pinched between the annular gripper 60 and the outer nose 40 to form a fluid-tight seal. The first end portion 31 of the inner nose 30 engages with the annular body 20 , which forces the inner nose 30 back against the inner tube 12 , such that the flared end 13 of the inner tube 12 is pinched between the outer nose 40 and the inner nose 30 to form a fluid-tight seal. Furthermore, the interference fit between the annular lip 34 of the inner nose 30 and the annular groove 25 of the annular body 20 , and the interference fit between the annular lip 44 of the outer nose 40 and the annular groove 26 of the annular body 20 , provide a fluid-tight seal that prevents fluid from flowing from the passageway 14 to the exterior of the double containment fitting 1 through a pathway extending between the annular body 20 and the inner nose 30 and between the annular body 20 and the outer nose 40 .
[0050] FIG. 7 depicts another embodiment of an annular body 20 ′ of the present invention. The annular body 20 ′ includes a first end portion 21 ′, an opposing, second end portion 22 ′, and a bore 23 ′ extending through the annular body 20 ′ between the first end portion 21 ′ and the second end portion 22 ′. The annular body 20 ′ includes a flexible wall 27 ′ which comprises multiple flutes 28 ′ or folds, which may allow the flexible wall 27 ′ to deform and the length of the flexible wall 27 ′ to increase under tension more than the length of the flexible wall 27 of the annular body 20 shown in FIG. 1B , which comprises a single flute 28 .
[0051] Embodiments of double containment fittings of the present invention (such as, for example, the double containment fitting 1 shown in FIGS. 2-5 ) provide a seal for the end of concentric tubes using a single threaded coupling.
[0052] Although the foregoing description contains many specific details, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some exemplary embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the spirit or scope of the present invention. Moreover, features from different embodiments of the invention may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the exemplary embodiments of the invention, as disclosed herein, which fall within the meaning and scope of the claims, are embraced thereby.
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A method and apparatus for joining the ends of concentric inner and outer tube to a double containment fitting are disclosed, as are related methods of fabrication and systems. The apparatus uses a threaded coupling to compressively engage and seal the ends of both the inner and outer tubes to the double containment fitting. The double containment fitting includes inner and outer noses and a threaded annular body and annular nut. The inner nose may be at least partially inserted within a flared end of the inner tube, and the outer nose may encircle the inner tube and be inserted within the flared end of the outer tube. The inner and outer noses and the inner and outer tubes may be engaged in a relationship within bores through the annular body and the annular nut. Threadably engaging the annular nut with the annular body may establish seals between the components.
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BACKGROUND OF THE INVENTION
This invention relates to a rotary type information retrieving machine, in which a multitude of information-containing cards are arranged in a designated sequence around a rotational body such as a cylindrical drum with one side of each information card being pivotally fitted thereon, and the rotational body is rotated in a definite direction to display the information-containing surfaces of the cards as selected in a viewing window of the retrieving machine.
This kind of device is provided with selection switches equal in number to the information cards, by the selection of which any one of the information cards is brought to the viewing window. Therefore, the selection key, the selection switch associated with the selection key, and the information card exactly correspond to each other in number.
However, with increase in the amount of information to be stored in the information cards, it becomes difficult to accommodate all the information cards as desired in a very limited space of the retrieving machine, maintaining the above-mentioned one-to-one relationship between the card and the selection key. Accordingly, it is necessary to cause a plurality of such information cards to be changed with a single selection key so that a greater number of cards may be accommodated in the retrieving machine.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention to provide an information retrieving apparatus of a type, in which the number of the information cards is increased by n times an integer with respect to the number of the selection switches and the number of the selection switches is inversely decreased to 1/n the number of the information cards.
It is another object of the present invention to provide an information retrieving apparatus capable of bringing into view the surfaces of the information cards which contain therein various useful informations such, for example, "answers" to "questions" in a self-study card, or "buying-in" and "customer" in commercial transaction, and so forth, thereby broadening utility of this kind of information retrieving apparatus.
According to the present invention, briefly stated, there is provided an information retrieving apparatus of a rotary type which comprises in combination a rotary member, a plurality of information cards arranged in any designated sequence and mounted on the rotary member, driving means to rotate the rotary member and the information cards, and switch means to select a rotational angle to regulate rotation of the driving means so as to bring any one of the information cards as selected into view in the retrieving machine, the regulated rotational angle of the driving means being changed by changing a corresponding relationship between a movable side and a fixed side of the rotational angle selection switch so that one angular change may apply to the information cards in number corresponding to integral multiples of the change in corresponding position of the rotational angle selection switch.
There has thus been outlined, rather broadly, the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions so far as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Specific embodiments of the present invention have been chosen for the purpose of illustration and description, and are shown in the accompanying drawings, forming a part of the specification, in which:
FIG. 1 is a perspective view showing one embodiment of the rotary type information retrieving apparatus according to the present invention;
FIG. 2 is a schematic control circuit diagram of the apparatus shown in FIG. 1;
FIG. 3 is an exploded perspective view of a part of the internal mechanism of the apparatus in FIG. 1;
FIG. 4 is a front view, partly cut away, of the power transmission mechanism of the apparatus in FIG. 1;
FIG. 5 is a front view, in longitudinal cross section, of a regulated rotational angle changing mechanism;
FIG. 6 is an explanatory diagram of changing the rotational angle;
FIG. 7 is a modification of the rotational angle selection switch; and
FIGS. 8 through 13 show various embodiments of changing the rotary contact.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following, preferred embodiments of the present invention will be described in detail in reference to the accompanying drawing.
Referring first to FIGS. 1 to 5, a reference numeral 1 designates a main body casing of the information retrieving apparatus, a numeral 2 refers to a display or card reading window formed in the front upper part of the main body casing 1, a reference numeral 3 designates a transparent cover fitted in the display window 2, a reference symbol M designates a drive motor for the rotational body, a numeral 6 refers to a speed reduction mechanism between the drive motor M and the rotary member 4, 7A to 7O are push button keys arranged in a panel board at the lower front face of the main body casing 1, the keys being associated with a well known self-sustaining type key board switch mechanism (for details, see laid-open Japanese Utility Model Application No. 49-121431 ) omitted from illustration in the main body casing, a reference numeral 9 designates fixed contacts for the rotational angle selection switch, a numeral 10 designates a movable (or rotary) contact being rotatably mounted on a shaft 11 relative to the fixed contact, the movable contact rotating with the rotary member 4.
In the illustrated example of the control electrical circuit in FIG. 2, a push button 7M is depressed and a switching element 7M-1 interlocked with the push button 7M is changed over from a constantly closed switching element 7M-NC to another constantly open switching element 7M-NO, both corresponding to the switching element 7M-1. In this state of the switching connection, the motor M drives to close a braking electric path through a circuit consisting of a conductor wire 12, a conductor wire 13 common to all the contact switches, the switching elements (7M-1, NO), a printed circuit (7M-2), one of the fixed contacts (9-7M), the movable contact 10, the conductor wire 14, a changeover switch (15-NC), a conductor wire 16, the motor M, whereby the counter electromotive force performs a braking function to cause the movable contact 10 to stop at the position of the fixed contact 9-7M. In this consequence, the rotary member 4 naturally stops, and one surface of the information card 4-7M corresponding to the selection push botton 7M appears in the display window 2. Depending on the size of the display window 2 and arrangement of the information cards, not only the front surface of the card 4-7L preceding the card 4-7M, but also its back surface can be shown simultaneously with the front surface of the card 4-7M. Incidentally, a reference numeral 17 designates an insulation between the adjacent contacts 9, 9.
The contacts NC of the switching elements 7A through 7O except for the circuit composed of a power source E, a conductor wire 18, a common conductor wire 19, the switching element 7M are in a closed state as shown in the drawing. However, as the movable contact 10 is stopped at the position of the fixed contact 9-7M in the rotational angle selection switch 9, the power source circuit E of the motor M is open. About a conductor wire 20, explanation will be made at a later paragraph.
When the selection push button 7H is depressed, the abovementioned switching element 7M-1 changes its contact from NO to NC, and the switching element 7H-1 from NC to NO. As the result, the motor circuit is closed in the routing of the power source E, the motor M, the conductor wire 16, the change-over switch (15-NC), the conductor wire 14, the movable contact 10, the fixed contact (9-7M), the printed circuit (7M-2), the switching element (7M-1, NC), the common conductor wire 19, the conductor wire 18, the power source E, whereby the motor M starts rotation to cause the rotary member 4 and the movable contact 10 to move to the rightward direction in this illustrated embodiment. By contacting the movable contact 10 with the subsequent position of 9-7N of the fixed contact 9, the circuit functions sequentially in a similar manner as mentioned above so as to maintain the closed condition of the motor circuit through the switching elements 7N-1, NC, whereby the motor M continues its rotation.
The information card 4-7M is pivotally supported at its lower edge on one of card fitting pins 22 provided on the peripheral part of a circular disc 21 mounted on the shaft 11 of the rotary member 4, while it is restricted its pivotal movement at its upper edge by a stopper pawl 20. As the rotary member 4 rotates in the arrow direction in FIGS. 2 and 3, the information card 4-7M is released from restriction by the stopper pawl 20 and falls down in the forward direction with the pin 22 as the center of its rotation. Subsequent information cards contact one by one the stopper pawl 20 in this manner, while the rotary member 4 is rotating. When the movable contact 10 moves to the fixed contact 9-7H, the power source circuit E of the motor M opens, since the contact NC of the switching element 7H-1 is in an open state. On the other hand, the abovementioned braking circuit consisting of the motor M, the conductor wire 12, the common conductor wire 13, the switching element (7H-1, NO), the fixed contact (9-7H), the movable contact 10, the conductor wire 14, the change-over switch (15-NC), the conductor wire 16, the motor M is closed, and the motor M and the rotary member 4 are immediately stopped by the counter electromotive force due to the inertial rotation of the motor M, whereby the card 4-7H appears in the display window 2.
The above-described construction is disclosed in the laid-open Japanese Utility Model application No. 52-19312 of the same inventor in his prior application. In this case, the information card and the card selection switch, i.e., rotational angle regulating switch (push buttons 7A through 7O, contacts NO and NC of the switching element 7A-1 to 7O-1, fixed contacts 9-7A to 9-7O) are in the same number.
The present invention is to solve the afore-described problem by changing the correspondence between the movable contact 10 of the rotational angle selection switch and the fixed contacts 9.
In the above-described embodiment, 15 push buttons 7A to 7O and the fixed contacts 9 are used. Accordingly, the distribution angle of the fixed contacts 9 is 24° degrees (360°/15). The correspondence between the movable contact 10 and the fixed contacts 9 is changed by rotating in the leftward direction the fixed contact panel 35 by α degree (e.g. 12°=24°/2). That is to say, the state in FIG. 6(1) is changed to the state of FIG. 6(2) by a changing knob 23. On the other hand, 30 sheets of the information cards are mounted on the pins provided on the disc 21 with an angular interval of 12°.
When the change-over switch 15 is changed over to the contact NO in association with the abovementioned change-over operation, a circuit consisting of the power source, the motor M, the conductor wire 16, the change-over switch (15-NO), the stopper pawl 20, the power source E is closed, and the motor M rotates the movable contact 10. The contact 10 moves to the subsequent position 9-7N of the contacts 9 to close the circuit consisting of the movable contact 10, the fixed contact (9-7N), the switching element (7N-1, NC) to continue rotation of the motor M and the rotary member 4, hence the movable contact 10 in the manner as described in the foregoing along with restoration of the change-over switch 15 to the contact NC.
Since the selection push button remains on 7H, the switching element 7H-1, NO is closed. When the movable contact 10 contacts with the fixed contact 9-7H, the abovementioned operations stop entirely. At this time, the fixed contact 9-7H is displaced by 12° (α) in the direction opposite to the rotational direction of the movable contact 10, so that the rotational angle of the rotary member 4 is smaller by 12 degrees than in the previous case. Accordingly, the card 4-7H2, positioned 12 degrees in the rotational direction of the circular disc 21 preceding the information card 4-7H, appears in the display window 2.
In more detail, by providing double cards 4-7A2, 4-7B2 . . . positioned between each of the preceding information cards 4-7A-4-7B disposed by 24 degrees as in the well known technique, and by providing regulating rotational angle changing means 23, 15, it is possible to bring into view, for example, the corresponding double card 4-7H2 (e.g., for answer), when the changing knob 23 is manipulated with the push button 7H, being, as it is, after the corresponding card 4-7H (e.g., for question) is brought into view by depression of the selection button 7H.
The changing means may be such one as shown in FIGS. 3 to 5, in which, when the changing knob 23 and a lever 23A integral therewith are depressed against a spring 25 to disengage a projection 26 from a recess 27, the change-over switch 15 is changed from the constantly closed contact NC over to the constantly open contact NO. When the changing knob 23 is rotated leftward in FIG. 3 together with a holder 28 until the holder 28 comes into contact with the stop 31, a link 32 connected with the holder 28 by a pin 30 causes the printed circuit board 35 of the wirings 7A-2 to 7O-2 and the fixed contacts 9 to rotate counter-clockwise by 12° with the shaft 11A of the rotary member 4 through pivot shaft 33 and link 34. At this position, when the projection 26 of the changing knob 23 is engaged with the recess 27A, the change-over switch 15 closes the contact NC.
FIG. 4 illustrates a construction, in which the shaft of the rotary member 4 is divided into the shaft 11A, at the side of the motor, and the the shaft 11 at the side of the cards. Both motor side shaft 11A and card side shaft 11 are joined together by fitting a spherical member 36 at the tip end of the motor side shaft 11A into a cylindrical member 37 at the tip end of the card side shaft 11 so that a projected pin 38 of the spherical member 36 may be snuggly fitted into a slot 39 formed in one part of the cylindrical member 37. To disengage the spherical member 36 and the projected pin 38 from the cylindrical member 37 and the slot 39, the shaft 11 is pulled rightward in the drawing against a pushing spring provided at a bearing portion on the opposite side of the rotary member 4, thereby connecting and disconnecting the rotary member 4 to and from the power transmission mechanism.
The illustrated embodiment uses the constantly closed contact NC and the constantly open contact NO as mentioned above as the switching elements interlocked with the push buttons 7A to 7O. Such switching element may also be of such a construction that, as described in the laid open Japanese Utility Model application No. 49-121431, any selected element is opened with a single piece of the constantly closed contact, and the power source circuit and the braking circuit of the motor M is changed over by the use of a relay switch.
FIG. 7 shows a selection switch consisting of a cylindrical contact member which rotates at the same speed as the rotary member 4 for the information card and is provided on the outer peripheral surface of a cylindrical conductive member 41 with a single spiral insulative section 42 with the total length of the cylindrical conductive member as one pitch and a contact member 45 which moves along a lever 44 in accordance with retrieving symbols 43 such as, for example, A, B, C, etc. By displacing the cylindrical conductive member 41 in the circumferential direction with respect to a supporting cylinder 46 against a frictionally engaged spring 47 by means of the regulating rotational angle changing knob 23, the present invention is applicable to a construction in which this rotational angle selection switch is utilized.
In the same manner, the present invention is applicable to a construction wherein a planar, spiral-shaped rotational angle selecting switch, which is provided with an insulative section in a spiral shape around the surface of the rotary disc-shaped conductor member, and in which the contact member, shifted in the radial direction of the circular disc, is utilized. Incidentally, the circuit construction, when these switching devices are used, is well known from the Japanese Utility Model publication No. 50-44798, and others.
FIGS. 8 to 13 show various embodiments of how the movable contact 10 is caused to contact the fixed contacts 9. Briefly, FIG. 8 indicates that the movable (or rotary) contact mechanically changes its contact with the fixed contacts 9 by increasing the number of such fixed contacts corresponding to the number of changing angle of the rotary contact 10. FIG. 9 indicates that the change in the rotary contact in FIG. 8 is done electrically through a switching element. FIG. 10 shows that the movable contact is moved for the amount of the angular change by manually turning a knob. FIG. 11 illustrates that the printed circuit board, on which the fixed contacts are provided, is moved to change the position with respect to the movable contact. FIG. 12 shows that the contact of the movable contact to the fixed contacts is mechanically changed by printing the fixed contact on the board for the number corresponding to the angular changes, and the necessary contact is chosen by the movable contact. FIG. 13 shows that the above-mentioned contact change in FIG. 12 is effected electrically by means of an electrical switching element.
As mentioned, the construction according to the present invention makes it possible to store and to retrieve two to three times as many information cards as there are retrieving symbols, by providing the regulated rotational change of the contact in two or three stages.
It is also possible that the abovementioned information cards are mounted on an endless belt rotary member, or they may be held in a card accommodating case.
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A rotary type index in which a multiplicity of information containing cards are arranged around a cylindrical drum and the drum is rotated to display information-containing surfaces of the cards in a viewing window is provided with a mechanism for causing a plurality of the information cards to be brought into position with a single selection key. This is as distinguished from the conventional drum type machine in which the number of selection switches equals the number of information cards.
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FIELD OF THE INVENTION
The present invention relates to the use of snake venom as an analgesic.
BACKGROUND OF THE INVENTION
Although pain is a crucially important physiological response, it also results in unnecessary suffering and agony. The control and relief of pain is an important branch of medicine. Pain may come about both as a result of disease as well as a result of medical treatment such as chemotherapy. In either case, it is important to alleviate the pain as much as possible so as to enable the sufferer to function normally.
Two neural pathways relating to pain act concurrently in the body: (1) a sensory pathway which senses tissue damage and subsequently produces a feeling of pain; (2) an analgesic pathway which reduces the feeling of pain and prevents the flow of information about the pain to the central nervous system (CNS), thus allowing the organism to maintain it's normal activity in spite of an injury. Anesthesia can be realized either by use of a drug which inhibits peripheral nerves that act as pain sensors or by enhancement of the natural analgesic system. Since these are different pathways, they are affected by different substances. For example, aspirin and lidocaine are active on the peripheral sensory pathway, while morphine and related substances are active on the analgesic system.
The most efficient analgesics currently in use are morphine-related substances of opiatic origin. It's well known that the brain makes a variety of endogenic opiates, and this explains the powerful effect of these substances. Their action on neurons is mediated by specialized receptors. Signals regulated by these receptors prevent the flow of information from the peripheral pain neurons to the CNS. These CNS neurons are also sensitive to a variety of other chemical substances including catecholamines (serotonin, noradrenalin etc.), neuroactive peptides (neurotensin) and inhibitory amino acids (glycin and GABA).
Out of some 4000 currently living species of snakes, approximately 400 species are known to be venomous. The venomous species are classified into five families, one of which is the Viperidae family, commonly known as vipers. Snakes of the Viperidae are distributed in Europe, Asia and Africa, and comprise 8 genera, one of which is the genus Vipera. The genus Vipera comprises the following species: V. berus; V. lebatina; V. russelii; V. superciliaris; V. ursinii; V. aspis; V. latifii; V. bornmulleri; V. ammodytes; V. xanthina; and V. mauritanica. The species V. xanthina has been further classified into three sub-species: V. xanthina raddei, V. xanthina xanthina, which is found generally in southern Europe, and V. xanthina palestinae which is found in Israel.
Snake venom comprises a large variety of different substances. Out of several hundreds of estimated compounds, it is believed that only 4-8 are involved in the toxic effect of the venom. Despite functional similarity, snake venoms differ considerably in their chemical composition. Each species possesses it's own characteristic venom composition. To date, only a few hundred compounds from some 400 venomous snake species have been characterized. These include enzymes, toxins, growth factors, etc. Most of the isolated venom compounds are of unknown function.
Traditionally, snake venom is considered a source of toxic substances. However, it is also a source of analgesics. Doctors who treated patients bitten by a South American snake ( Crotalus durissus terrificus ) reported that although these patients were in a life-threatening condition, they felt no pain. A neurotoxin product isolated from snake venom was regarded as a new type of analgesic at the First Congress of Neurotoxicology (1977) in Yugoslavia. These and other observations lead to attempts to isolate anesthetic compounds from snake venom.
Bevan, P. and Hiestand, P. (1983) J. Biol. Chem. 258:5319-5326 describe a single chain polypeptide isolated from Vipera russelli russelli venom by cation exchange chromatography. The polypeptide competes with the binding of monoamines and opiate ligands to their respective receptors, and injection of the polypeptide intracerebroventricularly in rats causes marked sedation. The authors state that the polypeptide is a large and highly charged molecule which is unlikely to pass the blood-brain barrier. The polypeptide was found to be a moderately potent toxin, similar to the crude venom.
Dutta, A. S. and Chaudhuri, A. K. N. (1991) Indian J. Exp. Biol. 29:937-942 describe experiments carried out with crude venom of Vipera russelli on mice and rats. The venom was injected intraperitoneally and intravenously, and was found to produce alterations in general behavior patterns connected with the CNS. The venom showed significant analgesic activity in one assay, but no activity in two other assays.
WO 91/01740 published Feb. 21, 1991 discloses the use of lyophilized Crotalus atrox whole venom in a pharmaceutical composition for external use. The composition has analgesic, hyperaemizating and spasmolysant activity.
Giorgi, R., Bernardi, M. M. and Cury, Y. (1993) Toxicon 31:1257-1265 describe analgesic effects evoked by low molecular weight substances extracted from Crotalus durissus terrificus venom by ultrafiltration. The extract was administered to mice subcutaneously, intraperitoneally and orally.
CN 1,072,344 published May 26, 1993 discloses a snake toxin ointment containing a commercial snake toxin enzyme (source not given), a leukocyte peptide factor and Bingpian, a known Chinese analgesic medicine. The ointment functions as an antibiotic with no toxicity or side effects.
Pu, X. C., Wong, P. T. H. and Gopalakrishnakone, P. (1995) Toxicon 33:1425-1431 describes a neurotoxin purified from king cobra venom by gel filtration and HPLC. The toxin was administered i.p., p.o. or i.c.v. to mice and found to have a potent analgesic effect.
U.S.S.R. Patent No. 435,824 describes an analgesic composition prepared from Nayaksin dry cobra venom. This snake is from the Naja species which belongs to the Elapidae family.
For over 20 years, an ointment named Viprosalum or Viprosal has been available in the former Soviet Union and in Eastern Europe for the relief of pain. This ointment is a mixture of a viper venom (European species) dissolved in Vaseline together with Lanolin, camphor and solicilate.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an analgesic substance isolated from snake venom which is substantially non-toxic.
According to one aspect of the present invention, there is provided a substantially non-toxic fraction isolated from the venom of Vipera xanthina, the fraction having an analgesic effect.
Further in accordance with this aspect of the present invention, there is provided a pharmaceutical composition for use as an analgesic comprising a substantially non-toxic fraction isolated from the venom of Vipera xanthina.
In a preferred embodiment of the present invention, the pharmaceutical composition is for topical use.
Although all of the experiments described below which illustrate the invention involve the sub-species Vipera xanthina palestinae (hereinafter V. palestinae ). It is to be understood that this sub-species serves only as an example for the entire species Vipera xanthina. As stated above, each venomous species possesses it's own characteristic venom composition.
The fraction provided by the invention combines a number of properties previously unreported as appearing together in the same material. These properties include: (1) derivation from Vipera xanthina venom; (2) possession of analgesic activity; (3) substantially no toxicity; (4) substantially purified; and (5) active when administered topically. This substance has been named “Zephalin”.
In the present specification, the term non-toxic is defined as the non-occurrence of pathological phenomena as a result of using pharmacological levels of Zephalin which have an analgesic effect. The term substantially non-toxic is defined as including acceptably low toxicity as well as non-toxicity.
Although Zephalin is a purified fraction of the crude venom, it apparently comprises more than one substance. The present invention includes not only Zephalin but also various products which may be purified from Zephalin and which possess the properties of Zephalin. The invention also includes derivatives of these products, which retain the properties of Zephalin. In the case of proteinaceous material, such derivatives would include proteins or polypeptides in which one or more amino acids have been added, deleted and/or replaced. Other chemical modifications are also contemplated.
Zephalin may be used to prepare a pharmaceutical composition for use as an analgesic. Such a composition would also comprise a pharmaceutically acceptable carrier or excipient such as a mixture of Lanolin and Vaseline. The composition may be prepared for parenteral use, for example in a saline solution, or for topical use in an ointment, cream or salve. In order to afford relief to a subject suffering from pain, the pharmaceutical composition would either be injected or applied topically at an appropriate location. Other possible modes of application would be oral and rectal. Any pharmaceutical composition would generally include a pharmaceutically acceptable carrier or excipient in addition to the active ingredient. As Zephalin sometimes acts after a lag period, it is to be expected that it will be especially effective with respect to chronic pain, although it may be used to treat any type of pain.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood from the following detailed description of preferred embodiments, taken in conjunction with the following drawings in which:
FIG. 1 is a graph showing the UV absorbency at a wavelength of 280 nm of column fractions eluted from a QAE Sephadex column on which Vipera palestinae venom was loaded.
FIGS. 2A and B are graphs illustrating the results obtained during purification of Zephalin on a Mono Q column. The Y-axis represents the UV absorbency at 280 nm and the X-axis is the elution time in minutes. Graph B is an enlargement of graph A in the region of 9-31 minutes, and at a lower range of absorbencies.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Materials and Methods
Vipera palestinae venom was obtained by milking several hundred snakes. Their venom was frozen and lyophilized.
A. Analgesic assay
In each test, a few tens of hamsters of similar weight and age were used. The hamsters were divided into groups according to the number of samples to be tested. Ointment (50% Lanolin and 50% Vaseline) containing the tested substance was applied to the animal's fur on the back region. The fur was not removed so as to ensure that no damage to the skin occurred. A control group of hamsters was treated with ointment without Zephalin. Hamsters were treated by topical application for 6, 14 or 21 consecutive days. The test for analgesity was conducted on the day following the last application of the ointment.
In a typical test, a constant amount of ointment with or without an analgesic substance is applied to each animal for a predetermined period of days. Following this period, pain is induced by a subcutaneous injection of 0.8 ml of 1N HCl/0.1 kg body weight in the femur region. The hamsters respond to the HCl injection by touching the area of injection with the tongue, this being called a “lick”. 20 minutes after injection the hamster is observed for 40 min and the number of “licks” are counted. The number of “licks” serves as a quantitative indication of the HCl induced pain.
The analgesic effect is determined by comparing the mean number of “licks” in control animals to the number in treated animals. The significance of the difference was determined using t-test statistics.
B. Lethal Dose determination
Four different concentrations of the tested substance were injected into the peritoneum of mice weighing 20-25 grams. Eight mice were injected with each concentration. The method of calculating the dose of the tested substance leading to 50% mortality (LD 50 ) is as described in Reed, L. J. and Muench, H. (1938) Am. J. Hygiene 27:493. An LD 50 unit is defined as the amount of tested substance necessary to cause the death of 50% of the injected mice per 20 g body weight (mg/20 g).
C. Toxicity determinations
Hamsters were used for short-term determinations (up to 10 days), in which the tested material was injected into the peritoneum for 10 days. Rats were used for long term determinations during which ointment was topically applied once a day, 6 days a week, over a period of 4 months (100 applications total).
D. Protein determination
The amount of proteinaceous material in Zephalin and its concentration in each separation were determined spectroscopically at 280 nm using an ovalbumin standard of a known concentration.
EXAMPLES
I. Purification of Zephalin
In a typical purification, 0.4 gr. of whole Vipera palestinae venom were dissolved in ammonium acetate buffer (0.05M pH 8.0) and applied to a QAE Sephadex (Pharmacia) ion exchange column (1.3×50 cm) which was equilibrated with the above buffer. The elution fractions were collected in 5 ml tubes (see FIG. 1 ). Protein content of the fractions was followed by measuring the optical density of the fractions at 280 nm. Following the elution of the second protein peak, a gradient of 2 M of ammonium acetate was applied which resulted in the elution of more A 280 absorbing fractions. Five groups of A 280 -absorbing fractions were pooled and all the five fraction pools were tested for toxicity in mice and analgesic activity (see below).
In a preferred isolation method, the QAE column is replaced by an FPLC Mono Q column (Pharmacia). In a typical experiment, 50-80 mg of V. palestinae venom were dissolved in 20 mM Tris buffer, pH 7.5, at a final concentration of 0.1 g/ml. Following centrifugation and the removal of the precipitate, the supernatant was filtered through a microfilter (40 micron) and 0.1-0.2 ml were applied to a 1×10 cm Mono Q column. The A solvent consisted of 20 mM Tris buffer pH 7.5 and the B buffer consisted of 20 mM Tris and 0.5M NaCl. Buffer A alone was used during the first 20 min of elution. During the following 45 min, a mixture of buffers A and B (50%:50%) was used and for the last 5 min, 100% buffer B was used. Zephalin eluted in the region of 20-25 min (see FIG. 2 B), as determined by various assays (see below). The elution can also be carried out using buffer A alone, which may be replaced by 20 mM ammonium acetate. Thirty purifications using the Mono Q column were carried out over a period of 18 months, all giving similar results.
II. Characterization of Zephalin
A. Determining the analgesic fraction pool
In this preliminary test, a very high concentration of each of fraction pools 1-5 (from the QAE Sephadex column, see I above) was used in order to identify the pool containing analgesic activity. Therefore, the analgesic activity was detected after only 6 days of application. Lyophilized material taken from each of fraction pools 1-5 was dissolved in an ointment composed of 50% Lanolin and 50% Vaseline at a concentration of 2 mg/g. 0.2 gr. of this ointment were applied daily over a period of 6 days to a group of 10 hamsters over an area of 2-3 cm 2 of fur, as described in the Methods section above. Protein, toxicity and analgesic activity for each pool were determined as described above. The results are summarized in Table 1.
TABLE 1
Analgesic effect
Toxicity
Number of licks
No. of LD 50 units
Pool number
(average + S.D.)
(mg/20 g)
Protein (mg*)
1
11.1 + 6.1
2880
86.4
(0.0004)
2
11.2 + 7.7 (0.003)
7.9
9.5
3
60.3 + 27.5 (0.8)
228
68.5
4
31.8 + 14.9 (0.09)
84
75.6
5
49.7 + 36.1 (0.7)
0
20.0
Control
45.2 + 30.7
—
0
*Protein was determined by the Lowry method using an ovalbumin standard.
The numbers in parenthesis signify probability values (p) obtained by t-test in comparison to control.
The analgesic activity was concentrated in pools 1 and 2. Pool 2 contained about 11% of the protein but only 0.002% of the toxicity. Pool 2 had the lowest toxicity between the two analgesic pools and the lowest amount of protein among all the pools. Fraction pool 2 was therefore used in further experiments as Zephalin. These findings indicate that the toxicity and analgesic activity reside in different venom components, and that Zephalin is substantially non-toxic (see also below).
The Zephalin prepared with the Mono Q column is completely separated from the toxic components of the venom, as discussed in Section IV.A1 below.
In subsequently described studies, the Zephalin used is that prepared by the QAE column, unless otherwise indicated.
B. The nature of Zephalin
In order to determine the nature of Zephalin, 0.1 mg of Zephalin prepared on a Mono Q column were dissolved in the solution buffer. In parallel, pronase E was prepared by dissolving 2.4 mg of pronase E in elution buffer (20 mM tris, pH 7.5). Three tubes were prepared, one containing the protease only, a second containing Zephalin only, and a third in which Zephalin was incubated with 5 μl of pronase E (0.17 micrograms). The tubes were incubated for 24 hr at room temperature, and then tested for analgesic activity.
The result was that only tube 2 had analgesic activity. This test was repeated 3 times with identical results. It can therefore be concluded that Zephalin is of a proteinaceous nature or a protein is required for it's analgesic activity.
C. Purity of Zephalin
The 20-25 min. fraction from the Mono Q column (see I above) contained 0.02±0.05 S.D. mg/ml protein, based on 10 separation runs. Each run resulted in a yield of 0.1 mg of Zephalin. This amount correspondents to 0.6% of the total venom protein applied to the column. This indicates the high purity of Zephalin.
III. Analgesic Activity
The analgesic activity of Zephalin was tested using preparations prepared over a period of two years. 0.2 ml of the Zephalin fraction containing 0.01 mg protein was dissolved in 50 gr of ointment resulting in a concentration of 0.0002 mg Zephalin/g ointment. Hamsters were topically treated with the ointment as described in the Methods section for 21 days. The results are summarized in Table 2.
TABLE 2
Date of
experi-
ment
May 1991
June 1991
December 1991
May 1992
April 1993
May 1993
September 1993
Sample*
3 ± 3
11 ± 15
8 ± 7
2 ± 4
17 ± 22
8 ± 5
16 ± 11
Control*
85 ± 29
44 ± 11
55 ± 28
16 ± 9
58 ± 45
49 ± 42
41 ± 34
p
0.000
0.0009
.0000
.0009
0.0142
.0008
0.028
*- average number of “licks” from 7 experimnents ± S.D.
These experiments show that the Zephalin treated hamsters had reduced sensation to the HCl induced pain as compared to the control.
IV. Toxicological Studies
A. Injection of Zephalin
A1. Mice (20-25 gr each) were injected s.c. with an amount of 0.05 mg of Zephalin prepared using the Mono Q column. This amount is 250 times the amount necessary to produce an analgesic effect in hamsters. At this dose, Zephalin was not toxic to the mice, and no visible symptoms were observed. In contrast, injection of 0.02 mg of the first fractions (tubes 2-7) eluted from the column caused immediate death of all 5 mice injected. This finding demonstrates the substantial non-toxicity of the analgesic fraction.
A2. In a further experiment, 3 groups of 8 hamsters (100-120 grams) each were injected. Lyophilized Zephalin was dissolved in a physiological saline solution at a concentration of 0.002 mg/ml and 0.1 ml or 0.2 ml were injected daily for 10 days into the peritoneum of the first and second groups, respectively. The third (control) group was injected with 0.2 ml of saline only. Following the 10 days of injections, blood was taken for the testing of biochemical parameters and histopathological tests.
Among the biochemical factors tested, an increase in cholesterol and amylase were observed in the first two groups (results not shown). However no significant changes were observed in the function of liver enzymes (LDH, SGOT, SGPT).
A3. The histopathology of the experimental animals of Section A2 was investigated. No significant histopathological differences were detected between the groups injected with Zephalin and the control group.
B. Topical treatment
Zephalin was prepared in ointment as described in the Methods section (analgesic assay). Three groups of 10 rats each (males and females) in a weight range of 120-140 g were used. The ointment was topically applied as described in the Methods section. The ointment applied to groups 1 and 2 comprised Zephalin at a concentration of 0.0002 and 0.001 mg/g, respectively. In group 3, the ointment comprised solvent alone as a control. 0.2 g of ointment were applied daily to each rat. During the four months of the experiment, each rat of group 1 received a total of 0.03 mg/kg body weight and each rat of group 2 received 0.15 mg/kg body weight. During the experiment, no changes in the rats' behavior or body weight were observed.
Blood and urine were collected in the laboratory. For collecting of urine, the animals were placed on a plastic surface, the urine collected and immediately tested using Multistick. For the taking of blood the rats were anesthetized and arterial blood taken. The plasma was removed by centrifugation, stored at 4° C. and tested for biochemical parameters.
B1. It was found that Zephalin caused a significant increase in the following blood enzyme levels: alanine aminotransferase (SGPT), aspartate aminotransferase (SGOT) and lactate dehydrogenase (LDH). However, when the experiment was repeated using the more purified Mono Q fraction, no increase in SGPT or SGOT was detected. No significant differences with the control group were detected in the following blood analyte levels: Cre; Ca 2− ; P(i); Glu; Ur; Chl; TP; Alb; Bili; Al.Phos; AMY (results not shown).
B2. The results of the measurement of various biochemical parameters in urine are summarized in Table 3:
TABLE 3
Specific
Blood Non-
Glucose
Biliriubin
Ketone
Activity
hemolyzed
pH
Protein
Uro-binogen
Nitrate
Leukocytes
Control
(−)
(+)1
(−)
1.014
(0)1
7.6
(0)2
0.2
(+)1
(0)1
(8 rats)
(−)7
(−)6
(−)7
(−)7
Zephalin 1
(−)
(+)1
(0)3
1.004
(0)4
8.0
(0)3
0.2
(−)
(0)1
0.001 mg/gr
(−)8
(−)6
(−)5
(−)6
(−8)
(9 rats 3 )
Zephalin 1
(−)
(−)
(0)1
1.006
(0)5
7.9
(6)4
0.2
(+)2
(0)3
0.0002 mg/gr
(−)5
(−)1
(−)2
(−)4
(−)3
(6 rats 3 )
Zephalin 2
(−)
(−)
(0)5
1.014
(0)2
6.9
(+ +)1
0.2
(−)
(−)
0.0002 mg/gr
(−)6
(−)9
(0)2
(11 rats 4 )
(−)8
1 . Purified on QAE Sephadex column
2 . Purified on Mono Q column
3 . Male and female rats used
4 . Only male rats used
The analyte levels in the table are indicated as follows: (−) negative; (0) traces; (+) low; (+ +) intermediate; (+ + +) high. The number following the parenthesis indicates the number of rats tested.
No significant differences were detected.
B3. The histopathology of adult rats treated topically with Zephalin dissolved in ointment was investigated. The day following the last application of ointment, the animals were sacrificed and their skins and tissues were removed and fixed in formalin. Tissues were embedded in paraffin and sliced into 6 micron slices. Hematoxylin and Oozin were used for staining. The following tissues were tested: (1) Skin in the area treated; (2) Skin in an untreated area; (3) heart; (4) kidneys; and (5) brain.
The tissues were taken from: (1) Eight out of ten rats treated with 0.0002 mg/g of analgesic fraction; (2) Six out of ten rats treated with 0.001 mg/g of analgesic fraction; and (3) the control of eight rats. All tested rats were chosen randomly.
The results are summarized in Table 4.
TABLE 4
Tissue
Zephalin (mg/Kg body weight)
treated
Control
(0.03)
(0.15)
Skin
decrease of
decrease of
decrease of 50-90%
50-90% in hair
50-90% in hair
in hair roots in all
roots in all rats
roots in all rats
rats
Heart
no change
no change
no change
Liver
in 2 livers, a
in one rat a chro-
in one rat a chronic
small and local
nic inflammatory
inflammatory site
case of neutro-
site; no changes
phils; in all
in others
other 6 no cha-
nges were seen
Kidney
no change
in one rat sites of
no change
expansion; in
others, no change
Brain
no change
no change
no change
The conclusion was that no significant histopathological changes were observed between the treated and control groups.
In summary, Zephalin was found to have no significant toxicity.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been thus far described, but rather the scope of the present invention is limited only by the following claims.
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A substantially non-toxic fraction isolated from the venom of Vipera xanthina is disclosed which fraction has an analgesic effect. The fraction is preferably purified on an ion exchange column from Vipera xanthina palestinae. Also described are a pharmaceutical composition for use as an analgesic comprising the non-toxic fraction, and a method for the relief of pain comprising administrating the non-toxic fraction.
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FIELD OF THE INVENTION
This invention relates to apparatus for the open-end spinning of yarn and particularly to apparatus of the kind known as friction spinning. Apparatus of this kind comprises two bodies of rotation each defining a surface and arranged such that the surfaces are closely adjacent at a line of closest approach so as to define between them at that line a yarn formation area, a fibre feed duct for feeding fibres into the yarn formation area which feed duct terminates closely adjacent the surfaces, means for rotating each of the bodies about a respective axis so as to twist the fibres in the area into a yarn, and means for withdrawing the yarn from the area.
BACKGROUND OF THE INVENTION
Apparatus of this kind has been disclosed in published British application No. 2 042 599 of Platt Saco Lowell and similar apparatus has been disclosed in various patents and patent applications by Barmag Barmer Maschinenfabrik AG, Dr. Ernst Fehrer and Vyzkumny Ustav Bavlnarsky. None of these apparatus has yet reached fully successful commercial exploitation. Neither Barmag nor Fehrer have concerned themselves with the problems of fibres remaining in the yarn formation area at an end break, possibly because they have not in their apparatus had the small tolerances and gaps necessary in this area to achieve optimum spinning performance and to reduce air losses. Vyzkumny in their U.S. Pat. No. 4,168,601 disclose an arrangement which also does not have the necessary small gaps and tolerances; but in this arrangement an inner cylindrical roller can be moved axially away from co-operation with the inner surface of an outer roller to allow cleaning of any material remaining in the spinning area at a stoppage and to perform the piecing up function. In this apparatus the spinning area is very large in comparison with the diameter of a yarn and hence there is no need for consideration of problems concerning excess material in that area during operation. The provisions for cleaning this form of apparatus would therefore be adequate to allow proper cleaning of the area although the structure is extremely cumbersome and therefore time consuming and also expensive to manufacture. It is also necessary to stop the motion of the surfaces.
In published British application No. 2 042 599 (particularly in FIG. 2) it is disclosed that one of the bodies can be moved away from the other and from the fibre feed duct, but this is only for purposes of adjustment of the small gaps between these parts for optimisation of the spinning conditions. Careful setting of the gap is necessary for any movement of the movable body in view of the very small tolerances necessary and when set the bodies and the feed duct are for all other purposes fixed.
SUMMARY OF THE INVENTION
It is an intention of the present invention to provide an open-end spinning apparatus of this kind wherein cleaning of any remaining fibres following a yarn break from the spinning area can be effected simply, quickly and without undue mechanical complication, and wherein any excess fibre material collecting in the spinning area does not cause damage. It is also an intention to provide methods of cleaning, following an end break, open-end spinning apparatus of this kind, which are simple quick and effective.
Accordingly the present invention is characterized in that there are provided means mounting the two bodies and the feed duct such that relative movement is provided between the feed duct and one of the bodies away from and back to the operating position in a direction transverse to the line and to increase and decrease respectively the spacing therebetween and means for defining the operating position such that the return to the operating position is made without the need for resetting.
Additionally the invention provides a method of cleaning following a yarn break an apparatus for open-end spinning of yarn of the type comprising two bodies of rotation each defining a surface and arranged such that in an operating position the surfaces are closely adjacent at a line of closest approach so as to define between them at that line a yarn formation area, suction means for developing an air stream through at least one of the surfaces at the yarn formation area, a fibre feed duct for feeding fibres into the yarn formation area which feed duct terminates in the operating position closely adjacent the surfaces, the method being characterized in the steps of causing relative movement between at least one of the bodies and the duct in a direction transverse to the line and to increase the spacing therebetween, and temporarily halting the airstream through the surface.
Furthermore the invention provides a further method of cleaning following a yarn break an apparatus for open-end spinning of yarn comprising a body having a perforated surface, means defining an elongate yarn formation area on the surface, suction means for developing an air stream through the surface at the yarn formation area, and a fibre feed duct for feeding fibres on to the yarn formation area, the method being characterized in that the airstream through the surface is gradually closed off from one end of the area toward the opposite end whereby to move any fibres remaining on the area toward the opposite end for ejection from the area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view (along the line I--I in FIG. 2) showing schematically the rollers and feed duct of a friction spinning apparatus according to the invention;
FIG. 2 is a cross-sectional view along the line II--II of FIG. 1 omitting the feed duct and mounting arrangements for the roller 2;
FIG. 3 is a view of the left hand end of FIG. 2;
FIG. 4 is a cross-sectional view similar to FIG. 2 along the lines IV--IV of FIG. 1; and
FIG. 5 is straightened out view of the slot 25 in the inner sleeve 24 of FIGS. 1 and 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference should be made to published British Patent Application No. 2 042 599 which discloses the structure and function of apparatus of this kind and the present description will for the most part concern those areas where the apparatus has been modified in accordance with the present invention.
The apparatus comprises a pair of cylindrical rollers 1 and 2 rotating in the direction shown by the arrows and arranged closely adjacent at a line of closest approach. The roller 1 is imperforate and comprises a solid metal roller. The roller 2 is perforated over the majority of its peripheral surface and has a duct 6 closely adjacent the inside surface with an elongate slot 7 which extends substantially fully along the roller 1 at or adjacent the line of closest approach.
Turning briefly to FIG. 4, the mounting and bearing arrangements are substantially as shown and fully described in the published application, as is the duct 6 (shown at 13 in the published application). A further duct 22 communicates suction from a suction source not shown with the duct 6 and terminates at an end collar 23 adjacent the perforated portion of the roller 1. An inner sleeve 24 coaxial with the roller 2 and duct 6 is arranged to have its peripheral surface closely adjacent the inner surface of the duct 6 to prevent leakages of air and has a slot 25 having the shape of a parallelogram as shown in FIG. 5, the purpose of which will be explained hereinafter. The sleeve 24 terminates at one end in a collar 26, for co-operation with the collar 23 to allow rotation of the sleeve 24 but to prevent axial movement, and at the other end in a shaft 27 which extends through a bore in the end of the duct 6 and which carries a manually operable lever 28 whereby the sleeve 24 can be rotated inside the duct 6.
A feed duct 8 is fixedly mounted on a portion of machine frame-work 9 shown only schematically; the details of the feed duct are more fully described in co-pending application Ser. No. 308,955, filed Oct. 6, 1981. It suffices to say here that the gaps between the rollers and between the rollers and the feed duct are kept small and the feed duct projects well in between the rollers toward the line of closest approach so that a small confined zone or yarn formation area is formed.
In this area fibres are fed from the feed duct and are twisted into yarn by the rotating of the rollers as disclosed in detail in the published application.
The roller 2 is mounted via the suction duct 6 on a machine frame member 10 substantially as shown in FIG. 1 of the published application No. 2 042 599 such that it is rigidly supported by the member 10 which in turn is rigidly connected to the frame member 9. Thus the feed duct 8 and roller 2 are fixed in relation to one another.
The roller 1 is mounted on a shaft 11 carried in bearings 12, 13 in turn supported in metal support plates 14, 15 such that the roller 1 is free to rotate in the plates 14, 15 but is rigidly supported thereby. The shaft carries a drive pulley 16 co-operating with a belt 17 which drives the roller and also drives the roller 2 by means not shown.
The plate 15 is a close fit within an opening cut in the frame member 10 and is carried on a pivot 18 rigidly fixed thereto. The plate 14 is similarly a close sliding fit within an opening in a further frame member 19 so that when in position in the frame member 19 it locates the roller 1 accurately relative to the feed duct 8 and the roller 2, in accordance with settings applied previously or during manufacture. A leaf spring 20 fixed to the frame member 19 by a screw 21 applies spring bias to the plate 14 so as to tend to maintain it in its position in the frame member 19. The spring is designed to apply only sufficient force to counteract the turning moment generated by pressure from the belt 17.
In use, under normal spinning conditions, the plate 14 remains in position in the frame member 19 and hence the settings between the rollers 1 and 2 and the feed duct 8 are maintained. However on an end break or any other fault occuring whereby an excessive amount of fibres enters the confined space defining the yarn formation area, the pressure developed by the excess fibres, tends to lift the roller 1 away from the feed duct by pivotting movement about the pivot 18 thus avoiding excessive force on the rollers and feed duct and possible resultant damage.
The axis of the pivot 18 lies in a plane parallel to one containing the axes of the rollers 1 and 2 and hence movement of the roller 1 is perpendicular to that plane.
It will be noted that the roller 2 tends to move any excess material away from the feed duct whereas the roller 1 tends to move it into the narrow gap between the feed duct and the roller. Hence movement only of the roller 1 is sufficient to prevent excess material causing damage. Additionally movement only of the roller 1 is more simply achieved because it does not have the complexity of mounting and suction connections necessary for the roller 2 (as shown in FIG. 4). However in an alternative arrangement motion of both of the rollers in this direction could be provided preferably by a pivoting arrangement.
Following the end break or fault it will be necessary to restart spinning and this necessitates cleaning of the yarn formation area to remove any remaining material. In practice after an end break a highly twisted mass of fibres is left along the spinning zone. This can be achieved simply and quickly and without disconnecting the drives to the rollers by the operative firstly moving the end of the roller 1 and the plate 14 upwardly against the spring bias on the pivot 18.
Secondly the lever 28 is manually turned anti-clockwise to rotate the inner sleeve 24 in the same direction. This causes the lower surface of the slot 25 to move upwardly to gradually close off the slot 7 from the end at the back of the unit adjacent the drive belt 17 forwardly to the front end of the slot so that the remaining elongate mass of fibres is drawn forwards by the remaining airflow through the open part of the slot along the slot and eventually ejected from the spinning area after the slot is fully closed. In practice, the mass falls from the spinning area through the space left between the feed duct 8 and the roller 1 after it has been lifted and can be caught beneath the spinning unit on a catch-tray (not shown) for later cleaning. The closing off of the slot 7 is carried out gradually from the back to carry the fibre mass away from the influence of the suction applied to the feed duct (not shown in these drawings but disclosed in the published application) and to assist in causing one end to fall from the feed duct thus releasing the whole of the mass. It is however possible in other embodiments merely to close off the length of the slot 7 simultaneously, preferably in a direction away from the feed duct 8, whereby the mass is ejected mainly by the effect of the ongoing rotation of the roller 2.
On release of the roller 1 and plate 14 by the operative it will return to its proper position guided by the sliding of the plate 14 in the frame member 19. In this way the plate 14 and frame member 19 define the return position for the roller 1 and the settings of the rollers and feed duct are maintained without need for further adjustment or resetting, until replacement of a roller is necessary. The lever 27 is finally returned to the initial position to reopen the slot 7 and recommence the airstream through the surface.
For a yarn piecing cycle substantially as disclosed in our European Application No. 0034427 (published on Aug. 26, 1981), the lever 28 can be moved also in a clockwise direction so that the upper surface of the slot 25 acts to close off the slot 7 from the front toward the back.
The invention can be applied also to apparatus including two perforated rollers by closing off the suction jointly at a point further upstream and by moving one or both of the rollers relative to the feed duct. Alternatively the feed duct can be moved away from fixed rollers.
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The yarn formation area of a friction spinning apparatus, in which the rotating friction rollers and the feed duct lie closely adjacent, is quickly and simply cleaned of remaining fibres at a yarn break and protection is provided against damage caused by excess fibres entering the area. One of the rollers, which is imperforate, is mounted for pivotal movement away from the area and at a break suction through the other roller is temporarily closed off from one end of the area toward the opposite end to eject the remaining fibres. Return movement of the roller is guided to ensure proper return to the operating position.
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BACKGROUND OF THE INVENTION
The invention relates to an electronic code locking mechanism according to the introductory part of claim 1.
In connection with the electronic door lock described in the article "Programmable Without Computer" (page 6 of trade association publication "interkey-sicher", No. 13/1993), a memory chip that is inductively connectable to a lock memory is arranged on the tip of the blade of the key. By means of a control element in the form of a special programming key, the memory of the lock is once set to the code of the key, the code being stored in the allocated (user) key as well. In the same way, the information can be erased again from the memory of the lock by means of an erase key in order to allocate such memory subsequently to another key code. However, the security standard so achievable remains to be low, comparatively speaking, because it is basically possible to intercept a wireless transmission of information by means of an external receiving element, which means it is possible to simulate the key by wireless re-entry of the intercepted key code. Furthermore, the fact that the programming key can be freely used for setting up any type of lock memory in any desired number represents a high security risk due to the lack of object-specific control functions. Most of all, however, an existing logistic problem is to obtain a replacement if the (user) key--which is allocated to the programming key in a fixed way--has been lost or copied in an unauthorized manner.
SUMMARY OF THE INVENTION
Realizing such circumstances, the present invention is, therefore, based on the technical problem of eliminating or, in any case, drastically limiting such logistic problems in connection with an electronic code locking mechanism according to the generic type.
According to the invention, the problem is substantially solved in that the characterizing features of the main claim are realized in connection with the code locking mechanism of the generic type as well.
According to said solution, any allocation of a key is possible only if the control element is allocated to the object as well, and then always remains linked to the object.
Preferably, the object is a motor vehicle whose drive interlock, the latter effectively securing such vehicle against theft when it is parked, can be deactivated only by means of an ignition key of the conventional type known per se; however, with a key code memory with a transponder being additionally accommodated within the zone of the handle of the a key, the memory being capable of communicating with a read-write unit on or within the closer vicinity of the lock. For this purpose, energy is inductively transmitted from the transponder of the lock to the transponder of the key preferably within the range of transition between the long-wave and the medium-wave radio bands of the electromagnetic radiation spectrum, in order to activate there the reading (and, if need be, also writing) circuit for the key memory for calling in information, in the way it is known as such, e.g. from the technology of the inductively operated transponders, and described in greater detail in the article by R. Jurisch, "Identification: Contactless Via High Frequency", published in Elektronik Heft September 1993, pp. 86 ff. However, the object may comprise stationary installations as well, which are to be made accessible or inaccessible by means of a key code that is available only to the authorized user.
In addition to the programming expenditure described in the earlier publication forming the present type, a problem associated with the realization of conventional coded key systems is--as compared to conventional mechanical locks--primarily the logistics bottleneck that occurs when the lock is changed or the key is lost. Such bottleneck, like the security risk that is associated with any open data transmission that is exposed to interception, and including the problems associated with the key-and-object allocation, is now overcome by the solution according to the invention, which no longer requires any logistic expenditure (as compared with existing, purely mechanical locking systems), and which permits the authorized user of the key to resolve, in a conventional way, all the important problems--as they may occur in everyday life--on his own without interrupting the chain of security functions of the system at some point, or without permitting such chain to be by-passed.
This is effected with a data communication by means of the read-write unit allocated to the locking mechanism with its intelligent coupling function between the key or the control transponder, on the one hand, and the memory of the object, on the other hand. As a precautionary measure, each wireless data interchange is encoded cryptographically, so that the data obtained in any unauthorized way is no longer usable. With keys having read-write transponders and read-write memories, all important information required for generating permissible key codes is--following installation in the object for the first time--stored in a control element, which is available to the authorized user, for example in the same way as a vehicle registration certificate. This means that only the user can cause replacement keys to function in limited numbers as needed (for example if a key has been lost) until the lock manufacturer or outfitter of the object makes a fresh or new control element (which is solely usable thereafter) available to such user. Furthermore, by means of such control element or through the exchange of the latter, it is possible to render the complete set of keys previously admissible null and void, which represents an important safety aspect in case of loss or if theft is suspected. Only the owner of the control element that is always the only one valid has and retains access to the safety chain, so that the safety chain can neither be by-passed or overcome in any unauthorized way either, for example via workshops.
A cryptographic algorithm realized in connection with the read-write unit in terms of hardware effects a code change with each use of the key, so that a transmission protocol, if it has been intercepted once in any unauthorized way, is no longer usable later. With a key fitted with a read-write transponder and a read-write memory, a roll-in (pseudo) random code can be newly entered in the memory of the key and in the memory of the lock after each use of the key. This represents an additional safety measure.
Recoding of keys is possible only if the read-write unit at the same time comprises--in addition to a key transponder--the transponder of the control element as well, the latter being authorized by a separate object identification.
The transmitting and receiving functions for the transponder data interchange, the cryptographic algorithm in terms of hardware, as well as, if need be, a microprocessor for the function of the control electronics are realized in an integrated circuit in the read-write unit of the lock, which is associated with the object in a fixed way. In addition to the external transmitter-receiver coil (transponder antenna), the lock or object memory can be externally connected to the circuit as well. The control electronics supplied by the read-write unit is designed in a way such that it is possible not only to compare received data with stored data with respect to conformity, but also to determine whether any information has already been allocated once to a transponder memory previously, or whether such memory is newly used, and for that reason has to be supplied first with object-specific safety data.
Additional further developments and alternatives, as well as additional features and advantages of the invention are disclosed in the other claims, and also in the following description of a preferred functional example relating to the solution according to the invention, such example being sketched in a highly abstract way as a single-pole block schematic diagram that is limited to the essential, taking into account the explanations contained in the final abstract as well. The only figure of the drawing shows the memories in the control element, in the key and in the lock, the memories communicating with each other via the object-specific read-write unit.
BRIEF DESCRIPTION OF THE DRAWING
The electronic code locking mechanism 11 sketched in the drawing is, for the present preferred example of realization, shown as a conventional locking cylinder 12 for a key 13 having the serrated profile 14 of its blade. An attached lock switch 15 simultaneously and/or successively--depending on the actual rotary position of the key--supplies the control information 16 (signal or power level) to a least one control element 17. The latter may be a part of the engine electronics of a motor vehicle drive, but can also be, for example a release control for rotary crosses, self-locking doors, or other functional or control devices. However, such control elements 17 becomes active or can be actuated only when a control electronics 18 supplies a release signal 19. Otherwise, and especially when the control electronics 18 supplies a blocking signal 20, the function of the control elements 17 is blocked in the secured position. Depending on the case of application of the code locking mechanism 11, such secured position may involve, for example the drive interlock engaging the engine management of a motor vehicle; the securing of a door to protect a (stationary or mobile) space against unauthorized access; or, for example the release of an emergency exit.
Therefore, the release signal 19 must be generated only when the locking mechanism 11 is actuated by an authorized, i.e., by an object-specifically allocated key 13. In any case, such allocation can be defined in the conventional way via the serrated profile 14, however, according to the present invention, such allocation is particularly (and additionally, if necessary) defined in that the key 13 is equipped, in its handle 21 not immersing in the locking cylinder 12, with a transponder 22 for the wireless transmission of a stored code 24 to a read-write unit 25 on the locking mechanism 11. The control electronics 18, which is functionally part of the read-write unit 25, is--in the preferred case of application as a motor vehicle drive interlock--an equipment component of the engine electronics. For such a case of application, the read-write unit 25 can be integrated preferably in an information system, or in the central locking electronics of the vehicle.
The locking mechanism is normally designed to be actuated with a set of several (for example four) identical keys 13, which can be distributed to authorized persons. In addition to the coded keys 13, a control element 26 with the transponder 27 is associated with the individual lock memory 29. However, as opposed to the key 13, the control element is not inserted in the locking mechanism 11, but has to be brought only into the vicinity of the read-write unit 25 of the locking mechanism 11. Therefore, the control element 26 can be designed, for example in the form of a pendant, a badge, or preferably--as shown--of a card 28 of the type of a credit card, in order to serve as the carrier element especially for its transponder 27. The interrogation algorithm of the read-write unit 25 is designed in such a way that it is capable of accommodating the transponder 22 of the key and the control transponder 27.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
At the time the object is completed (i.e., for example at the end of an assembly line of a motor vehicle production plant, or upon installation of the door of a building), such object being equipped with the locking mechanism 11 and the control electronics 18 in front of its control elements 17, the object-specific data 30 (such as the chassis or engine number of a motor vehicle, or the order or object number on the building construction sector) are read into its volatile memory 29 and additionally transmitted--for example inductively via the control electronics 18 and by means of the read-write unit 25 of the locking mechanism 11--to a nonvolatile memory 32 of the control element 26 via the control transponder 27. Such a card 28, which is programmed with the product-specific or location-specific identification data 30, can thus assume in the future the function of an access ID-card or of a motor vehicle registration certificate.
Moreover, a number (e.g. eight at the most) binary-coded key codes 34 of the keys 13--which have been previously equipped already with such codes by the manufacturer--can be transmitted by means of the read-write unit 25 into a corresponding multi-digit key register 33 of the control element 26, or already stored fixed on the card 28 by the manufacturer.
In the first case, the keys 13 need to be equipped only with a read-only transponder 22 and the volatile memory 23. For allocating the control element 26, one of the keys of the current set of keys 13 is inserted in the locking mechanism 11, and its key code 34 is transmitted via the read-write unit 25 of the first position of the key register 33, as well as to the memory 29 of the locking mechanism. Otherwise, one of the key numbers made available by the manufacturer in the key register 33 of the control element 26 is transmitted--as the key code 34--via the read-write unit 25 to the memory 23 of the still-uncoded key 13, in combination with the object-specific identity data 30 just transmitted to the control element 26, if the blade of such key 13 has switched the locking switch 15 to the read-status, and if the read-write unit 25, upon interrogating the key transponder 22, has determined that no key code 34 has been entered as yet in its memory 23. In this way, all mechanically fitting but still neutral (in terms of encoding) keys 13 of the set to be allocated to the locking mechanism 11 are programmed one after the other with the first key code 34--which has been present by the control element 26--by simply inserting the keys one after the other in the locking mechanism 11 and turning the key in the latter for the purpose of actuating the locking mechanism switch 15, while the control element 26, too, is sufficiently close (in terms of space) to the read-write unit 25 of exactly the locking mechanism 11 for the high-frequency transmission.
In addition, in the course of such pairing, the currently valid key code 34 interchanged between the key 13 and the control element 26 is stored by the read-write unit 25 in the memory 29 of the locking mechanism. Due to the fact that in this process, the control element 26 acknowledges for the locking mechanism memory 29 also the object-specific identification data 30, the initially neutral read-write unit 25 is now associated in a fixed way via its memory 29 with the control element 26, with the object, and with the keys 13.
The control element 26, furthermore, has an ident generator 35 which, when a key code 34 is called in for the first time, transmits at the same time via the read-write unit 25 its ident number 36 to the control electronics 18 in order to once and finally overwrite in this way in the memory 29 a set-up code 31, the latter being predetermined for the first start-up. In this way too, said individual control element 26 is associated in a fixed way with the object-specific control electronics 18 because any new overwriting of the respective position in the memory 29--for example for any later adaptation of the control electronics 18 to another control element 26--is excluded in terms of circuit engineering.
Owing to the fact that the allocation patterns involve wireless transmissions, it is basically not possible to exclude that an unauthorized person intercepts the data communication traffic by means of such person's own transponder brought close to the system, and in this way obtains, by electric storing of the code, for example an electronic key imitation. In order to prevent such person from any later unauthorized triggering of the release signal 19 of the control electronics 18 with the switch 15 in a bridged condition, the transmission of the key code 34 (thus the combination of the currently valid key number and the object-specific identification data 30 previously read in) takes place via a cryptographic code that changes after each actuation of the key. In each case, said cryptographic code is transmitted by a cryptographic encoder 38 of the read-write unit 25 to the external transponder 22, 27 in the key and respectively in the control element 26 specifically for the data transfer to come, in order to encipher with the code the directly following transmission of information. Therefore, even if an unauthorized person were able to intercept the code, which is generated in terms of hardware, this would be of no use to such person because each interchange of information takes place via the read-write unit 25, and a new code is present by the unit for the next interchange of information.
Moreover, the key code 34 can be additionally provided with a quasi-random code 37 if the keys 13 are equipped with the read-write transponders 22 and the nonvolatile memories 23. For this purpose, the read-write unit 25, when a key code 34 is allocated, additionally generates a roll-in random code 37 (or at least a pseudo-random code 37), which is stored via the control electronics 18 in the memory 29 as well if and as long as the same control element 26 is kept available sufficiently close (for the data interchange) to the read-write unit 25 of the allocated locking mechanism 11.
Now, as soon as the owner of a key 13 so programmed activates in the locking mechanism 11 via the locking mechanism switch 15 (for example in the ignition key position "radio" or "ignition") the operating signal 10, the key 13 is treated as "authorized" by the read-write unit 25 of the locking mechanism 11 if the control electronics 18 recognizes the key code 34 (and, if need be, additionally the random code 37 individually allocated to said set of keys 13) on the basis of the data preset in the memory 29 of the locking mechanism. In case of matching, the control electronics 18 supplies the release signal 19, so that it is possible, for example to start an engine, or to release an electromagnetic door lock.
In the event a key 13 fits mechanically with respect to the serrated profile 14 but such key is invalid with respect to the key code 34 and to the current random code 37, if any, the control electronics 18 prevents generation of a release signal 19, or a separate blocking signal 20 is triggered in order to indicate a manipulation attempt, for example by emitting or storing a signal, or to trigger an additional security locking system.
Should a key 13 get lost, the previous key code 34 in the memory 29 of the locking mechanism is erased as a precautionary measure by being called in by the control element 26. As heretofore, the vehicle owner may then order a set of replacement keys by submitting papers documenting his authorization (such as, for example directly the object-specifically marked control element 26), such set of replacement keys having a serrated profile 14 which mechanically fits the locking mechanism 11. If only a read-transponder 22 is available on the key 13, such key is again equipped by the manufacturers with a key code 34, which is transmitted by the read-write unit 25 to its memory 29 and to the next, still unused register position of the control element 26, the latter being covered by such transmission at the same time and being allocated object-specifically. Otherwise, the read-write unit 25 determines whether a previously unused key number is still available in the register 33 for future key sets, marks such number as now being used (or erases it), and transmits the key number (combined with the key code 34) to the locking mechanism memory 29 and to the read-write memory 23--the letter having been recognized as previously blank--of the replacement key 13 to be currently programmed.
Such procurement of replacement keys can be repeated as often as new codes 34--which are to be called in from already--programmed keys 13--can still be stored in the control element 26, or until the last of the key numbers present on the control element 26 has been used. Thereafter, and also after a control element 26 has been lost, a new control element 26 with an again fully available register 33 has to be allocated to the specific object via the identity data 30. As the read-write unit 25 has already been used once previously for the transfer of key codes 34 in connection with another control element 26, the ident generator 35, for example, in the (new) control element 26 is modified by the read-write unit 25 in a way such that the following now can be recognized from the ident number 36. The control element 26 present is the only permissible control element 26 for this locking mechanism 11, but it is no longer the control element 26 that had been allocated originally. The (old) ident number 36 becomes unusable in this way, so that no unauthorized person can later encode a key 13 with the (for example stolen or found) original control element 26. The object-specific identity data 30, which are accessible only to the manufacturer of the object and its control element 26, assure that not some control element 26 obtained somewhere can be used for recoding additional keys 13, but only that control element 26 in which the manufacturer has already entered the object-specifically valid identity data 30, because no object-specific identity data 30 can be transmitted later to another control element 26 by a read-write unit 25 that has been operated once before.
In this way, a set of keys 13 that has been coded once before can be finally rendered unusable by merely exchanging the control element 26, because for security reasons, the content of its memories 23 cannot be overwritten by a new key code 34.
If the read-write unit 25 installed in or on the locking mechanism 11 or within the vicinity of the latter should become unusable on account of a technical defect and have to be replaced for that reason, the new read-write unit 25 transmits the ident number 36 of the control element 26--the latter being kept available nearby--to the control electronics 18 in combination with a new random code 37, and writes the number into the memory 29 provided that the ident number 36 actually read out by the control element 26 matches the only already stored, which means the object-specific allocation of the control element 26 continues to be assured.
If the functional range in which the control electronics 18 is included or covered (for example the engine management electronics) has to be replaced, the random code 37 allocated the last time, and also the object-specific ident data are not as yet available to the object memory 29 being replaced at the same time, so that the release signal cannot be generated even with a key 13 that has been allocated per se. However, the original set-up code 31 now indicating the spare part exchange is then still contained in the new object memory 29. When the control element 26 is interrogated for the first time, the set-up code 31 is overwritten with its ident number 36 (which, as stated above, is possible only when the first communication contact of the control element 26 occurs after the spare part has been installed). By virtue of such transmission of the ident number 36, the read-write unit 25 automatically generates a new random code 39, which is stored in the object memory 29 as well. In addition, the key number, the latter having been marked as being current, is transferred from the key register 33 to the new object memory 29 combined with the key code 34. This means that all information is now available in the memory in order to make it possible to determine, via the control electronics 18, the presence of an acceptable key 13, and to transmit subsequently the release signal 19.
If a validly encoded key 13 is no longer available, but only a key that is mechanically fitting the locking mechanism 11, the release signal 19 can be triggered as an emergency measure with such a key as well if only the control element 26 allocated to the object is present within the reception range of the antenna of the locking mechanism, i.e., of the read-write unit 25. For this reason, the coded control element 26 normally has to be carefully safeguarded against unauthorized access, like a motor vehicle registration certificate or a credit card.
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A code locking mechanism that transmits information between a key and a locking mechanism secured against interception misuse, but flexible with respect to original equipment, replacement parts, and emergency functions, is obtained if the key code is, in each case, cryptographically encoded through a hardware encoder. When the locking mechanism is first operated, a control element, inductively coupled to a locking mechanism read-write unit with a new key once and in a non-overwritable manner, transmits an indent number to the object memory. Object-specific identity data are also stored in the control element. With the latter, a key number from a key register of the control element is combined with the key code to read the latter together with a roll-in random code into the set of first still-neutral keys and into the object memory. Thus, a key is valid only if the object-specific identity data are taken into account in its key code. This is possible only through programing via a credit card-like control element which, as the only valid specimen, once has been allocated to the specific object in a fixed way after the locking mechanism is operated, or a component is replaced.
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TECHNICAL FIELD
[0001] The present invention relates to a process and apparatus for the production of nano-scale catalyst metal particles, and the direct attachment of the particles to support materials, especially in a continuous manner. By the practice of the present invention, nano-scale catalyst particles can be produced with greater speed, precision and flexibility than can be accomplished with conventional processing, and the particles produced can be directly affixed to support materials in a precise and cost-effective manner.
BACKGROUND OF THE INVENTION
[0002] Catalysts are becoming ubiquitous in modern chemical processing. Catalysts are used in the production of materials such as fuels, lubricants, refrigerants, polymers, drugs, etc., as well as playing a role in water and air pollution mediation processes. Indeed, catalysts have been ascribed as having a role in fully one third of the material gross national product of the United States, as discussed by Alexis T. Bell in “The Impact of Nanoscience on Heterogeneous Catalysis” (Science, Vol. 299, pg. 1688, 14 Mar. 2003).
[0003] Generally speaking, catalysts can be described as small particles deposited on high surface area solids. Traditionally, catalyst particles can range from the sub-micron up to tens of microns. One example described by Bell is the catalytic converter of automobiles, which consist of a honeycomb whose walls are coated with a thin coating of porous aluminum oxide (alumina). In the production of the internal components of catalytic converters, an aluminum oxide wash coat is impregnated with nanoparticles of a platinum group metal catalyst material. In fact, most industrial catalysts used today include platinum group metals especially platinum, rhodium and iridium or alkaline metals like cesium, at times in combination with other metals such as iron or nickel.
[0004] The size of these catalyst metal domains has been recognized as extremely significant in their catalytic function. Indeed it is also noted by Bell that the performance of a catalyst can be greatly affected by the particle size of the catalyst particles, since properties such as surface structure and the electronic properties of the particles can change as the size of the catalyst particles changes.
[0005] In his study on nanotechnology of catalysis presented at the Frontiers in Nanotechnology Conference on May 13, 2003, Eric M. Stuve, of the Department of Chemical Engineering of the University of Washington, described how the general belief is that the advantage of use of nano-sized particles in catalysis is due to the fact that the available surface area of small particles is greater than that of larger particles, thus providing more metal atoms at the surface to optimize catalysis using such nano-sized catalyst materials. However, Stuve points out that the advantages of the use of nano-sized catalyst particles may be more than simply due to the size effect. Rather, the use of nanoparticles can exhibit modified electronic structure and a different shape with actual facets being present in the nanoparticles, which provide for interactions which can facilitate catalysis. Indeed, Cynthia Friend, in “Catalysis On Surfaces” (Scientific American, April 1993, p. 74), posits catalyst shape, and, more specifically, the orientation of atoms on the surface of the catalyst particles, as important in catalysis. In addition, differing mass transport resistances may also improve catalyst function. Thus, the production of nano-sized metal particles for use as catalysts on a more flexible and commercially efficacious platform is being sought. Moreover, other applications for nano-scale particles are being sought, whether for the platinum group metals traditionally used for catalysis or other metal particles.
[0006] Conventionally, however, catalysts are prepared in two ways. One such process involves catalyst materials being bonded to the surface of carrier particles such as carbon blacks or other like materials, with the catalyst-loaded particles then themselves being loaded on the surface at which catalysis is desired. One example of this is in the fuel cell arena, where carbon black or other like particles loaded with platinum group metal catalysts are then themselves loaded at the membrane/electrode interface to catalyze the breakdown of molecular hydrogen into its component protons and electrons, with the resulting electrons passed through a circuit as the current generated by the fuel cell. One major drawback to the preparation of catalyst materials through loading on a carrier particle is in the amount of time the loading reactions take, which can be measured in hours in some cases.
[0007] To wit, in U.S. Pat. No. 6,716,525, Yadav and Pfaffenbach describe the dispersing of nano-scale powders on coarser carrier powders in order to provide catalyst materials. The carrier particles of Yadav and Pfaffenbach include oxides, carbides, nitrides, borides, chalcogenides, metals and alloys. The nanoparticles dispersed on the carriers can be any of many different materials according to Yadav and Pfaffenbach, including precious metals such as platinum group metals, rare earth metals, the so-called semi-metals, as well as non-metallic materials, and even clusters such as fullerenes, alloys and nanotubes.
[0008] An additional drawback to the use of conventional carrier-particle loaded catalysts lies in the fact that the typical method of applying these materials to the support on which they are to be employed is by forming a suspension of the particles in a fluoroelastomer and then painting the admixed fluid onto the support, after which the suspension is “baked” to bond the content to the support, leaving a coating of the catalyst coated carrier particles on the surface of the support. This method does not allow for a great deal of precision, resulting in the application of catalyst material at locations where it is not needed or desired. Given the cost of catalyst materials, especially the noble metal materials typically considered most efficacious, this “painting” method of application of catalysts is extremely disadvantageous.
[0009] Alternatively, the second common method for preparing catalyst materials involves directly loading catalyst metals such as platinum group metals on a support without the use of carrier particles which can interfere with the catalytic reaction. For example, many automotive catalytic converters, as discussed above, have catalyst particles directly loaded on the aluminum oxide honeycomb which forms the converter structure. The processes needed for direct deposition of catalytic metals on support structures, however, are generally operated at extremes of temperature and/or pressures. For instance one such process is chemical sputtering at temperatures in excess of 1,500° C. and under conditions of high vacuum. Thus, these processes are difficult and expensive to operate.
[0010] Thus, a Hobson's choice is created: either use the method entailing painting catalyst-loaded carrier mixtures, with the resultant inefficiencies, or use the expensive and difficult direct deposition methods currently available. A partial solution to the dilemma lies in the potential for catalytic activity in nano-scale non-noble metals. That is, it is believed that metals such as nickel and iron, if present as nano-scale particles, may be effective as catalysts. While this may ameliorate some of the issues concerning the cost of noble metals, the inefficiencies of the “painting” method and cost and difficulties of direct deposition methods remain.
[0011] In an attempt to provide nano-scale catalyst particles, Bert and Bianchini, in International Patent Application Publication No. WO 2004/036674, suggest a process using a templating resin to produce nano-scale particles for fuel cell applications. Even if technically feasible, however, the Bert and Bianchini methods require high temperatures (on the order of 300° C. to 800° C.), and require several hours. Accordingly, these processes are of limited value.
[0012] Taking a different approach, Sumit Bhaduri, in “Catalysis With Platinum Carbonyl Clusters,” Current Science, Vol. 78, No. 11, 10 June 2000, asserts that platinum carbonyl clusters, by which is meant polynuclear metal carbonyl complexes with three or more metal atoms, have potential as redox catalysts, although the Bhaduri publication acknowledges that the behavior of such carbonyl clusters as redox catalysts is not understood in a comprehensive manner. Indeed, metal carbonyls have been recognized for use in catalysis in other applications.
[0013] Metal carbonyls have also been used as, for instance, anti-knock compounds in unleaded gasolines. However, more significant uses of metal carbonyls are in the production and/or deposition of the metals present in the carbonyl, since metal carbonyls are generally viewed as easily decomposed and volatile resulting in deposition of the metal and carbon monoxide.
[0014] Generally speaking, carbonyls are transition metals combined with carbon monoxide and have the general formula M x (CO) y , where M is a metal in the zero oxidation state and where x and y are both integers. While many consider metal carbonyls to be coordination compounds, the nature of the metal to carbon bond leads some to classify them as organometallic compounds. In any event, the metal carbonyls have been used to prepare high purity metals, although not for the production of nano-scale metal particles. As noted, metal carbonyls have also been found useful for their catalytic properties such as for the synthesis of organic chemicals in gasoline antiknock formulations.
[0015] Accordingly, what is needed is a process and apparatus for the production of nano-scale metal catalyst particles for direct deposition on a support. More particularly, the desired process and apparatus can be used for the preparation of nano-scale catalyst particles directly on a surface without the requirement for extremes in temperature and/or pressures.
SUMMARY OF THE INVENTION
[0016] A process and apparatus for the production of nano-scale catalyst particles is presented. By nano-scale particles is meant particles having an average diameter of no greater than about 1,000 nanometers (nm), e.g., no greater than about one micron. More preferably, the particles produced by the inventive system have an average diameter no greater than about 250 nm, most preferably no greater than about 20 nm.
[0017] The particles produced by the invention can be roughly spherical or isotropic, meaning they have an aspect ratio of about 1.4 or less, although particles having a higher aspect ratio can also be prepared and used as catalyst materials. Aspect ratio refers to the ratio of the largest dimension of the particle to the smallest dimension of the particle (thus, a perfect sphere has an aspect ratio of 1.0). The diameter of a particle for the purposes of this invention is taken to be the average of all of the diameters of the particle, even in those cases where the aspect ratio of the particle is greater than 1.4.
[0018] In the practice of the present invention, a decomposable metal-containing moiety is fed into a reactor vessel and sufficient energy to decompose the moiety applied, such that the moiety decomposes and nano-scale metal particles are deposited on a support. The decomposable moiety used in the invention can be any decomposable metal-containing material, including an organometallic compound, a metal complex or a metal coordination compound, provided that the moiety can be decomposed to provide free metals under the conditions existing in the reactor vessel, such that the free metal can be deposited on a support. Preferably, the decomposable moiety for use in the invention is a metal carbonyl, such as nickel or iron carbonyls, or noble metal carbonyls.
[0019] The particular decomposable moiety or moieties employed depends on the catalyst particle desired to be produced. In other words, if the desired nano-scale catalyst particles comprise nickel and iron, the decomposable moieties employed can be nickel carbonyl, Ni(CO) 4 , and iron carbonyl, Fe(CO) 5 ; likewise, if noble metal nano-scale catalyst particles are sought, then noble metal carbonyls can be used as the starting materials. In addition, polynuclear metal carbonyls such as diiron nonacarbonyl, Fe 2 (CO) 9 , triiron dodecocarbonyl, Fe 3 (CO) 12 , decacarbonyldimanganese, Mn 2 (CO) 10 can be employed; indeed, many of the noble metal carbonyls can be provided as polynuclear carbonyls, such as dodecacarbonyl-triruthenium, Ru 3 (CO) 12 , and tri-p-carbonyl-nonacarbonyltetrairidium, Ir 4 (CO) 12 . Moreover, heteronuclear carbonyls, like Ru 2 Os(CO) 12 , Fe 2 Ru(CO) 12 and Zn[Mn(CO) 5 ] 2 are known and can be employed in the production of nano-scale catalyst particles in accordance with the present invention. The polynuclear metal carbonyls can be particularly useful where the nano-scale catalyst particles desired are alloys or combinations on more than one metallic specie.
[0020] The metal carbonyls useful in producing nano-scale catalyst particles in accordance with the present invention can be prepared by a variety of methods, many of which are described in “Kirk-Othmer Encyclopedia of Chemical Technology,” Vol. 5, pp. 131-135 (Wiley Interscience 1992 ). For instance, metallic nickel and iron can readily react with carbon monoxide to form nickel and iron carbonyls, and it has been reported that cobalt, molybdenum and tungsten can also react carbon monoxide, albeit under conditions of higher temperature and pressure. Other methods for forming metal carbonyls include the synthesis of the carbonyls from salts and oxides in the presence of a suitable reducing agent (indeed, at times, the carbon monoxide itself can act as the reducing agent), and the synthesis of metal carbonyls in ammonia. In addition, the condensation of lower molecular weight metal carbonyls can also be used for the preparation of higher molecular weight species, and carbonylation by carbon monoxide exchange can also be employed.
[0021] The synthesis of polynuclear and heteronuclear metal carbonyls, including those discussed above, is usually effected by metathesis or addition. Generally, these materials can be synthesized by a condensation process involving either a reaction induced by coordinatively unsaturated species or a reaction between coordinatively unsaturated species in different oxidation states. Although high pressures are normally considered necessary for the production of polynuclear and heteronuclear carbonyls (indeed, for any metal carbonyls other than those of transition metals), the synthesis of polynuclear carbonyls, including manganese, ruthenium and iridium carbonyls, under atmospheric pressure conditions is also believed feasible.
[0022] It must be borne in mind in working with the metal carbonyls, that care in handling must be used at all times, since exposuire to metal carbonyls can be a serious health threat. Indeed, nickel carbonyl is considered to be one of the more poisonous inorganic industrial compounds. While other metal carbonyls are not as toxic as nickel carbonyl, care still needs to be exercised in handling them.
[0023] The inventive process is advantageously practiced in an apparatus comprising a reactor vessel, at least one feeder for feeding or supplying the decomposable moiety into the reactor vessel, a support which is operatively connected to the reactor vessel for deposit thereon of nano-scale catalyst particles produced on decomposition of the decomposable moiety, and a source of energy capable of decomposing the decomposable moiety. The source of energy should act on the decomposable moiety such that the moiety decomposes to provide nano-scale metal particles which are deposited on the support.
[0024] The reactor vessel can be formed of any material which can withstand the conditions under which the decomposition of the moiety occurs. Generally, where the reactor vessel is a closed system, that is, where it is not an open ended vessel permitting reactants to flow into and out of the vessel, the vessel can be under subatmospheric pressure, by which is meant pressures as low as about 250 millimeters (mm). Indeed, the use of subatmospheric pressures, as low as about 1 mm of pressure, can accelerate decomposition of the decomposable moiety and provide smaller nano-scale particles. However, one advantage of the inventive process is the ability to produce nano-scale particles at generally atmospheric pressure, i.e., about 760 mm. Alternatively, there may be advantage in cycling the pressure, such as from sub-atmospheric to generally atmospheric or above, to encourage nano-deposits within the structure of the particles or supports. Of course, even in a so-called “closed system,” there needs to be a valve or like system for relieving pressure build-up caused, for instance, by the generation of carbon monoxide (CO) or other by-products. Accordingly, the use of the expression “closed system” is meant to distinguish the system from a flow-through type of system as discussed hereinbelow.
[0025] When the reactor vessel is a “flow-through” reactor vessel, that is, a conduit through which the reactants flow while reacting, the flow of the reactants can be facilitated by drawing a partial vacuum on the conduit, although no lower than about 250 mm is necessary in order to draw the reactants through the conduit towards the vacuum apparatus, or a flow of an inert gas such as argon can be pumped through the conduit to thus carry the reactants along the flow of the inert gas.
[0026] Indeed, the flow-through reactor vessel can be a fluidized bed reactor, where the reactants are borne through the reactor on a stream of a fluid. This type of reactor vessel may be especially useful where the nano-scale metal particles produced are intended to be attached to carrier materials, like carbon blacks or the like, flowing along with the reactants.
[0027] The at least one feeder supplying the decomposable moiety into the reactor vessel can be any feeder sufficient for the purpose, such as an injector which carries the decomposable moiety along with a jet of a gas such as an inert gas like argon, to thereby carry the decomposable moiety along the jet of gas through the injector nozzle and into the reactor vessel. The gas employed can include a reactant, like oxygen or ozone. Alternatively, a reducing gas, such as hydrogen, may be advantageous in precluding oxidation of the metal nano particles. This type of feeder can be used whether the reactor vessel is a closed system or a flow-through reactor.
[0028] Supports useful in the practice of the invention can be any material on which the nano-scale catalyst particles produced from decomposition of the decomposable moieties can be deposited and utilized; more specifically, the support is the material on which the catalyst metal is ultimately destined, such as the aluminum oxide honeycomb of a catalytic converter in order to deposit nano-scale particles on catalytic converter components without the need for extremes of temperature and pressure required by sputtering and like techniques.
[0029] The support can be disposed within the reactor vessel (indeed this is required in a closed system and is practical in a flow-through reactor). However, in a flow-through reactor vessel, the flow of reactants can be directed at a support positioned outside the vessel, at its terminus, especially where the flow through the flow-through reactor vessel is created by a flow of an inert gas.
[0030] The energy employed to decompose the decomposable moiety can be any form of energy capable of accomplishing this function. For instance, electromagnetic energy such as infrared, visible, or ultraviolet light of the appropriate wavelengths can be employed. Additionally, microwave and/or radio wave energy, or other forms of sonic energy can also be employed (example, a spark to initiate “explosive” decomposition assuming suitable moiety and pressure), provided the decomposable moiety is decomposed by the energy employed. Thus, microwave energy, at a frequency of about 2.4 gigahertz (GHz) or induction energy, at a frequency which can range from as low as about 180 hertz (Hz) up to as high as about 13 mega Hz can be employed. A skilled artisan would readily be able to determine the form of energy useful for decomposing the different types of decomposable moieties which can be employed.
[0031] One preferred form of energy which can be employed to decompose the decomposable moiety is heat energy supplied by, e.g., heat lamps, radiant heat sources, or the like. Such energy sources can be especially useful for highly volatile moieties, such as metal carbonyls. In such case, the temperatures needed are no greater than about 250° C. Indeed, generally, temperatures no greater than about 200° C. are needed to decompose the decomposable moiety and produce nano-scale catalyst particles therefrom.
[0032] Depending on the source of energy employed, the reactor vessel should be designed so as to not cause deposit of the nano-scale metal particles on the vessel itself (as opposed to the support) as a result of the application of the source of energy. In other words, if the source of energy employed heats the reactor vessel itself to a temperature at or somewhat higher than the decomposition temperature of the decomposable moiety during the process of applying heat to the decomposable moiety to effect decomposition, then the decomposable moiety will decompose at the walls of the reactor vessel, thus coating the reactor vessel walls with nano-scale metal particles rather than depositing the nano-scale metal particles on the support (one exception to this general rule occurs if the walls of the vessel are so hot that the decomposable carbonyl decomposes within the reactor vessel and not on the vessel walls, as discussed in more detail below).
[0033] One way to avoid this is to direct the energy directly at the support. For instance, if heat is the energy applied for decomposition of the decomposable moiety, the support can be equipped with a source of heat itself, such as a resistance heater in or at a surface of the support such that the support is at the temperature needed for decomposition of the decomposable moiety and the reactor vessel itself is not. Thus, decomposition occurs at the support and deposition of nano-scale catalyst particles occurs principally on the support. When the source of energy employed is other than radiant heat, the source of energy can be chosen such that the energy couples with the support, such as when microwave or induction energy is employed. In this instance, the reactor vessel should be formed of a material which is relatively transparent to the source of energy, especially as compared to the material from which the support is formed.
[0034] Similarly, especially in situations when the support is disposed outside the reactor vessel such as when a flow-through reactor vessel is employed with the support at its terminus, where the appropriate conditions of gas mixture, pressure and temperature exist so that decomposition and deposition take place, the initial decomposition of the decomposable moiety may occur as the moiety is flowing through the flow-through reactor and the reactor vessel should be transparent to the energy employed to decompose the decomposable moiety. The majority of the decomposition of the decomposable moiety takes place at the heated support to effectively form and bond the nano-clusters to the support. Alternatively, whether or not the support is inside the reactor vessel, or outside it, the reactor vessel can be maintained at a temperature below the temperature of decomposition of the decomposable moiety, where heat is the energy employed. One way in which the reactor vessel can be maintained below the decomposition temperatures of the moiety is through the use of a cooling medium like cooling coils or a cooling jacket. A cooling medium can maintain the walls of the reactor vessel below the decomposition temperatures of the decomposable moiety, yet permit heat to pass within the reactor vessel to heat the decomposable moiety and cause decomposition of the moiety and production of nano-scale catalyst particles on or within the support.
[0035] In an alternative embodiment which is especially applicable where both the walls of the reactor vessel and the gases in the reactor vessel are generally equally susceptible to the heat energy applied (such as when both are relatively transparent), heating the walls of the reactor vessel, when the reactor vessel is a flow-through reactor vessel, to a temperature substantially higher than the decomposition temperature of the decomposable moiety can permit the reactor vessel walls to themselves act as the source of heat. In other words, the heat radiating from the reactor walls will heat the inner spaces of the reactor vessel to temperatures at least as high as the decomposition temperature of the decomposable moiety. Thus, the moiety decomposes before impacting the vessel walls, forming nano-scale particles which are then carried along with the gas flow within the reactor vessel, especially where the gas velocity is enhanced by a vacuum. This method of generating decomposition heat within the reactor vessel is also useful where the nano-scale particles formed from decomposition of the decomposable moiety are being attached to carrier materials (like carbon black) also being carried along with the flow within the reactor vessel. In order to heat the walls of the reactor vessel to a temperature sufficient to generate decomposition temperatures for the decomposable moiety within the reactor vessel, the walls of the reactor vessel are preferably heated to a temperature which is significantly higher than the temperature desired for decomposition of the decomposable moiety(ies) being fed into the reactor vessel, which can be the decomposition temperature of the decomposable moiety having the highest decomposition temperature of those being fed into the reactor vessel, or a temperature selected to achieve a desired decomposition rate for the moieties present. For instance, if the decomposable moiety having the highest decomposition temperature of those being fed into the reactor vessel is nickel carbonyl, having a decomposition temperature of about 50° C., then the walls of the reactor vessel should preferably be heated to a temperature such that the moiety would be heated to its decomposition temperature several (at least three) millimeters from the walls of the reactor vessel. The specific temperature is selected based on internal pressure, composition and type of moiety, but generally is not greater than about 250° C. and is typically less than about 200° C. to ensure that the internal spaces of the reactor vessel are heated to at least 50° C.
[0036] In any event, the reactor vessel, as well as the feeders, can be formed of any material which meets the requirements of temperature and pressure discussed above. Such materials include a metal, graphite, high density plastics or the like. Most preferably the reactor vessel and related components are formed of a transparent material, such as quartz or other forms of glass, including high temperature robust glass commercially available as Pyrex® materials.
[0037] Thus, in the process of the present invention, decomposable metal-containing moieties are fed into a reactor vessel and exposed to a source of energy sufficient to decompose the moieties and produce nano-scale catalyst particles. The decomposable moieties are fed into a closed-system reactor under vacuum or in the presence of an inert gas; similarly, the moieties are fed into a flow-through reactor where the flow is created by drawing a vacuum or flowing an inert gas through the flow-through reactor. The energy applied is sufficient to decompose the decomposable moiety in the reactor or as it as flowing through the reactor, and free the metal from the moiety and thus create nano-scale catalyst particles which are deposited on a support. Where heat is the energy used to decompose the decomposable moiety, temperatures no greater than about 250° C., more preferably no greater than about 200° C. are required to produce nano-scale catalyst particles, which can then be directly deposited on the substrate for which they are ultimately intended without necessitating the use of carrier particles and in a process requiring only second and not under extreme conditions of temperature and pressure.
[0038] In one embodiment of the inventive process, a single feeder feeds a single decomposable moiety into the reactor vessel for formation of nano-scale catalyst particles. In another embodiment, however, a plurality of feeders each feeds decomposable moieties into the reactor vessel. In this way, all feeders can feed the same decomposable moiety or different feeders can feed different decomposable moieties, such as additional metal carbonyls, so as to provide nano-scale particles containing different metals such as platinum-nickel combinations or nickel-iron combinations as desired, in proportions determined by the amount of the decomposable moiety fed into the reactor vessel. For instance, by feeding different decomposable moieties through different feeders, one can produce a nano-scale particle having a core of a first metal, with domains of a second or third, etc. metal coated thereon. Indeed, altering the decomposable moiety fed into the reactor vessel by each feeder can alter the nature and/or constitution of the nano-scale particles produced. In other words, if different proportions of metals making up the nano-scale particles, or different orientations of the metals making up the nano-scale particles is desired, altering the decomposable moiety fed into the reactor vessel by each feeder can produce such different proportions or different orientations as can variations in temperature along the vessel.
[0039] Indeed, in the case of the flow-through reactor vessel, each of the feeders can be arrayed about the circumference of the conduit forming the reactor vessel at approximately the same location, or the feeders can be arrayed along the length of the conduit so as to feed decomposable moieties into the reactor vessel at different locations along the flow path of the conduit to provide further control of the nano-scale particles produced.
[0040] Therefore it is an object of the present invention to provide a process for the production of nano-scale catalyst particles and deposit thereof on a support.
[0041] It is another object of the present invention to provide a process capable of producing nano-scale catalyst particles deposited on a support under conditions of temperature and/or pressure less extreme than conventional processes.
[0042] It is a further object of the present invention to provide an apparatus which permits the production of nano-scale catalyst particles and direct deposit thereof on a support.
[0043] It is still another object of the present invention to provide an apparatus which permits the production of nano-scale catalyst particles and direct deposit thereof on a support in a continuous process.
[0044] These objects and others which will be apparent to the skilled artisan upon reading the following description, can be achieved by feeding at least one decomposable moiety selected from the group of organometallic compounds, metal complexes, metal coordination compounds, and mixtures thereof into a reactor vessel; exposing the decomposable moiety to a source of energy sufficient to decompose the moiety and produce nano-scale catalyst particles; and depositing the nano-scale catalyst particles on a support. Preferably, the decomposable moiety comprises a metal carbonyl.
[0045] In an advantageous embodiment of the invention, the temperature within the reactor vessel is no greater than about 250° C. The pressure within the reactor vessel is preferably generally atmospheric, but pressures which vary between about 1 mm to about 2000 mm can be employed. The reactor vessel is preferably formed of a material which is relatively transparent to the energy supplied by the source of energy, as compared to either the support on which the nano-scale catalyst particles are collected or the decomposable moieties themselves, such as where the source of energy is radiant heat. In fact, the support can have incorporated therein a resistance heater, or the source of energy can be a heat lamp. Where the source of energy is heat, the reactor vessel can be cooled, such as by a cooling medium like cooling coils or a cooling jacket disposed about the reactor vessel to preclude decomposition of the moiety and deposit of nano-clusters on the reactor vessel walls.
[0046] The support can be the end use substrate for the nano-scale catalyst particles produced within the reactor vessel, such as a component of an internal combustion engine system, especially automotive, catalytic converter or a fuel cell or electrolysis membrane or electrode. The support can be positioned within the reactor vessel. However, the reactor vessel can be a flow-through reactor vessel comprising a conduit, in which case the support can be disposed either external to the reactor vessel or within the reactor vessel.
[0047] It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operations of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] FIG. 1 is a side plan view of an apparatus for the production of nano-scale catalyst particles utilizing a “closed system” reactor vessel in accordance with the process of the present invention.
[0049] FIG. 2 is a side plan view of an alternate embodiment of the apparatus of FIG. 1 .
[0050] FIG. 3 is a side plan view of an apparatus for the production of nano-scale catalyst particles utilizing a “flow-through” reactor vessel in accordance with the process of the present invention.
[0051] FIG. 4 is an alternative embodiment of the apparatus of FIG. 3 .
[0052] FIG. 5 is another alternative embodiment of the apparatus of FIG. 3 , using a support external to the flow-through reactor vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring now to the drawings, an apparatus in which the inventive process for the production of nano-scale catalyst particles can be practiced is generally designated by the numeral 10 or 100 . In FIGS. 1 and 2 apparatus 10 is a closed system comprising closed reactor vessel 20 whereas in FIGS. 3-5 apparatus 100 is a flow-through reaction apparatus comprising flow-through reactor vessel 120 .
[0054] It will be noted that FIGS. 1-5 show apparatus 10 , 100 in a certain orientation. However, it will be recognized that other orientations are equally applicable for apparatus 10 , 100 . For instance, when under vacuum, reactor vessel 20 can be in any orientation for effectiveness. Likewise, in flow-through reactor vessel 120 , the flow of inert carrier gas and decomposable moieties or the flow of decomposable moieties as drawn by a vacuum in FIGS. 3-5 can be in any particular direction or orientation and still be effective. In addition, the terms “up” “down” “right” and “left” as used herein refer to the orientation of apparatus 10 , 100 shown in FIGS. 1-5 .
[0055] Referring now to FIGS. 1 and 2 , as discussed above apparatus 10 comprises a closed-system reactor vessel 20 formed of any material suitable for the purpose and capable of withstanding the exigent conditions for the reaction to proceed inside including conditions of temperature and/or pressure. Reactor vessel 20 includes an access port 22 for providing an inert gas such as argon to fill the internal spaces of reactor vessel 20 , the inert gas being provided by a conventional pump or the like (not shown). Similarly, as illustrated in FIG. 2 , port 22 can be used to provide a vacuum in the internal spaces of reactor vessel 20 by using a vacuum pump or similar device (not shown). In order for the reaction to successfully proceed under vacuum in reactor vessel 20 , it is not necessary that an extreme vacuum condition be created. Rather negative pressures no less than about 1 mm, preferably no less than about 250 mm, are all that are required.
[0056] Reactor vessel 20 has disposed therein a support 30 which can be attached directly to reactor vessel 20 or can be positioned on legs 32 a and 32 b within reactor vessel 20 . Reactor vessel 20 also comprises a sealable opening shown at 24 , in order to permit reactor vessel 20 to be opened after the reaction is completed to remove support 30 . Closure 24 can be a threaded closure or a pressure closure or other types of closing systems, provided they are sufficiently air tight to maintain inert gas or the desired level of vacuum within reactor vessel 20 .
[0057] Apparatus 10 further comprises at least one feeder 40 , and preferably a plurality of feeders 40 a and 40 b , for feeding reactants, more specifically the decomposable moiety, into reactor vessel 20 . As illustrated in FIGS. 1 and 2 , two feeders 40 a and 40 b are provided, although it is anticipated that other feeders can be employed depending on the nature of the decomposable moiety/moieties introduced into vessel 20 and/or end product nano-scale catalyst particles desired. Feeders 40 a and 40 b can be fed by suitable pumping apparatus for the decomposable moiety such as venturi pumps or the like (not shown).
[0058] As illustrated in FIG. 1 , apparatus 10 further comprises a source of energy capable of causing decomposition of the decomposable moiety. In the embodiment illustrated in FIG. 1 , the source of energy comprises a source of heat, such as a heat lamp 50 , although other radiant heat sources can also be employed. In addition, as discussed above, the source of energy can be a source of electromagnetic energy, such as infrared, visible or ultraviolet light, microwave energy, radio waves or other forms of sonic energy, as would be familiar to the skilled artisan, provided the energy employed is capable of causing decomposition of the decomposable moiety.
[0059] In one embodiment, the source of energy can provide energy that is preferentially couple-able to support 30 so as to facilitate deposit of nano-scale catalyst particles produced by decomposition of the decomposable moiety on support 30 . However, where a source of energy such as heat is employed, which would also heat reactor vessel 20 , it may be desirable to cool reactor vessel 20 using, e.g., cooling tubes 52 (shown partially broken away) such that reactor vessel 20 is maintained at a temperature below the decomposition temperature of the decomposable moiety. In this way, the decomposable moiety does not decompose at the surfaces of reactor vessel 20 but rather on support 30 .
[0060] In an alternative embodiment illustrated in FIG. 2 , support 30 itself comprises the source of energy for decomposition of the decomposable moiety. For instance, a resistance heater powered by connection 34 can be incorporated into support 30 such that only support 30 is at the temperature of decomposition of the decomposable moiety, such that the decomposable moiety decomposes on support 30 and thus produces nano-scale catalyst particles deposited on support 30 . Likewise, other forms of energy for decomposition of the decomposable moiety can be incorporated into support 30 .
[0061] Support 30 can be formed of any material sufficient to have deposit thereon of nano-scale catalyst particles produced by decomposition of the decomposable moiety, such as the aluminum oxide or other components of an automotive (or other internal combustion engine) catalytic converter, or the electrode or membrane of a fuel cell or electrolysis cell. Indeed, where the source of energy is itself embedded in or associated with support 30 , selective deposition of the catalytic nano-scale metal particles can be obtained to increase the efficiency of the catalytic reaction and reduce inefficiencies or wasted catalytic metal placement. In other words, the source of energy can be embedded within support 30 in the desired pattern for deposition of catalyst metal, such that deposition of the catalyst nano-scale metal can be placed where catalytic reaction is desired. In one embodiment, support 30 can be coated with an adhesive coating (not shown), or a fluoroelastomer, to impart alternative properties to support 30 .
[0062] In another embodiment of the invention, as illustrated in FIGS. 3-5 , apparatus 100 comprises a flow-through reactor vessel 120 which includes a port, denoted 122 , for either providing an inert gas or drawing a vacuum from reactor vessel 120 to thus create flow for the decomposable moieties to be reacted to produce nano-scale catalyst particles. In addition, apparatus 100 includes feeders 140 a , 140 b , 140 c , which can be disposed about the circumference of reactor vessel 102 , as shown in FIG. 5 , or, in the alternative, sequentially along the length of reactor vessel 120 , as shown in FIGS. 3 and 4 .
[0063] Apparatus 100 also comprises support 130 on which nano-scale catalyst particles are deposited. Support 130 can be positioned on legs 132 a and 132 b or, in the event a source of energy is incorporated into support 130 , as a resistance heater, the control and wiring for the source of energy in support 130 can be provided through line 134 , as illustrated in FIG. 4 . Support 130 can be coated with an adhesive coating (not shown), or a fluoroelastomer, to modify the properties of the support 130 .
[0064] As illustrated in FIGS. 3 and 4 , when support 130 is disposed within flow-through reactor vessel 120 , a port 124 is also provided for removal of support 130 with nano-scale catalyst particles deposited thereon. In addition, port 124 should be structured such that it permits the inert gas fed through port 122 and flowing through reactor vessel 120 to egress reactor vessel 120 (as shown in FIG. 3 ). Port 124 can be sealed in the same manner as closure 24 discussed above with respect to closed system apparatus 10 . In other words, port 124 can be sealed by a threaded closure or pressure closure or other types of closing structures as would be familiar to the skilled artisan.
[0065] As illustrated in FIG. 5 , however, support 130 can be disposed external to reactor vessel 120 in flow-through reactor apparatus 100 . In this embodiment, flow-through reactor vessel 120 comprises a port 124 through which the conditioned decomposable moiety and perhaps reduced nano-scale catalyst particles are impinged on heated support 130 to thus produce and deposit the nano-scale catalyst particles on support 130 . In this way it is no longer necessary to gain access to reactor vessel 120 to remove support 130 having nano-scale catalyst particles deposited thereon. In addition, during the impingement of the moieties and nano-scale catalyst particles on support 130 , either port 126 or support 130 can be adjusted in order to maximize the utilization of the moiety and produced nano-scale catalyst particles by focusing on certain specific areas of support 130 . This is especially useful where support 130 comprises the end use substrate for the nano-scale catalyst particles such as the component of a catalytic converter or electrode for fuel cells. Thus, the nano-scale catalyst particles are only deposited where desired and efficiency and decrease of wasted catalytic metal is facilitated.
[0066] As discussed above, reactor vessel 20 , 120 can be formed of any suitable material for use in the reaction provided it can withstand the temperature and/or pressure at which decomposition of the decomposable moiety occurs. For instance, the reactor vessel should be able to withstand temperatures up to about 250° C. where heat is the energy used to decompose the decomposable moiety. Although many materials are anticipated as being suitable, including metals, plastics, ceramics and materials such as graphite, preferably reactor vessels 20 , 120 are formed of a transparent material to provide for observation of the reaction as it is proceeding. Thus, reactor vessel 20 , 120 is preferably formed of quartz or a glass such as Pyrex® brand material available from Corning, Inc. of Corning, N.Y.
[0067] In the practice of the invention, either a flow of an inert gas such as argon or a vacuum is drawn on reactor vessel 20 , 120 and a stream of decomposable moieties is fed into reactor vessel 20 , 120 via feeders 40 a , 40 b , 140 a , 140 b , 140 c . The decomposable moieties can be any metal containing moiety such as an organometallic compound, a complex or a coordination compound, such as a metal carbonyl, which can be decomposed by energy at the desired decomposition conditions of pressure and temperature. For instance, the decomposable moiety should be subject to decomposition and production of nano-scale metal particles at temperatures no greater than 250° C., more preferably no greater than 200° C. Other materials, such as oxygen, can also be fed into reactor 20 , 120 to partially oxidize the nano-scale metal particles produced by decomposition of the decomposable moiety, to protect the nano-scale particles from degradation. Contrariwise, a reducing material such as hydrogen can be fed into reactor 20 , 120 to moderate oxidation of the nano-scale catalyst particles.
[0068] The energy for decomposition of the decomposable moiety is then provided to the decomposable moiety within reactor vessel 20 , 120 by, for instance, heat lamp 50 , 150 . If desired, reactor vessel 120 can also be cooled by cooling coils 52 , 152 to avoid deposit of nano-scale catalyst particles on the surface of reactor vessel 20 , 120 as opposed to support 30 , 130 . The nano-scale catalyst particles are bonded to support 30 , 130 by the decomposition of the decomposable moieties decomposed at the surface of support 30 , 130 for use.
[0069] Thus the present invention provides a facile means for producing nano-scale catalyst particles on a support which permits selective placement of the particles and direct deposit of the particles on the end use substrate, without the need for extremes of temperature and pressure required by prior art processes. In addition, when a “flow-through” apparatus is used the process is also continuous, providing desired economies of scale.
[0070] All cited patents, patent applications and publications referred to herein are incorporated by reference.
[0071] The invention thus being described, it will be apparent that it can be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention and all such modifications as would be apparent to one skilled in the art are intended to be included within the scope of the following claims.
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A process and apparatus for producing nano-scale catalyst particles includes feeding at least one decomposable moiety selected from the group consisting of organometallic compounds, metal complexes, metal coordination compounds and mixtures thereof into a reactor vessel; exposing the decomposable moiety to a source of energy sufficient to decompose the moiety and produce nano-scale metal particles; and depositing the nano-scale catalyst particles on a support.
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BACKGROUND OF THE INVENTION
[0001] The invention relates generally to computer systems and deals more particularly with a system and method for determining which resources a user can access.
[0002] In many computing systems, there is a need to determine whether a user who is requesting information or some other resource is allowed to access the resource. A common technique to determine whether the user is allowed to access the resource involves authentication and authorization. Authentication is the process of determining whether the requesting user is, in fact, the user that has been represented by the user. This is typically done by comparing the ID and password submitted by the user to entries in an authentication table to determine if they match. The ID submitted by the user can be an ID associated with the user as an individual or an ID associated with a group in which the user is a member. Authorization is the process of determining whether the authenticated user or group has been granted access (i.e. has been authorized) to access the resource that has been requested. The authorization system indicates which resources each individual user is permitted to access and which resources each group is permitted to access. These authorizations may have been assigned previously by a system administrator to control access to sensitive or restricted resources. It is common for authentication and authorization to be handled as separate steps, although in most cases the authentication system is closely tied to the authorization system.
[0003] Some times, the same user has different user IDs or can gain access through a group ID for a group in which the user is a member. Each different user ID can be permitted to access different resources. For example, Mr. Jones as an individual can be granted access to resource X via one user ID and Mr. Jones as an individual can be granted access to resource Y via a different user ID. Also, Mr. Jones as part of a group can be granted access to resources Z via another group ID. Thus, the resources that a given user is permitted to access depends on what ID the user submits with his or her request. While such a technique is effective in controlling access to sensitive or restricted resources, a single person may need to make multiple requests with multiple IDs to access all the resources that the person is permitted to access.
[0004] Accordingly, an object of the present invention is to simplify the authorization process for a user to access different resources where the user has or can use more than one ID and each ID alone is not granted authority to access all of these resources.
SUMMARY OF THE PRESENT INVENTION
[0005] The present invention resides in a method and system for authorizing access to resources requested by a first user. To begin the process, the first user submits an ID of the first user as an individual requesting access to one of the resources. The first user is also a member of a group comprising a plurality of individual users. The user ID is authenticated although the authentication process is not part of the present invention. The present invention includes various tables and programs involved in the authorization process. A first table indicates at least one group of a plurality of individual users. A second table indicates which resources are accessible by which of the users and which resources are accessible by which of the groups. An authorization program compares the first user to entries in the first table to determine which group or groups the first user is a member. Next, the authorization program compares the first user and the group or groups in which the first user is a member to entries in the second table to determine which resources the first user is authorized to access. Thus, the resources that the user ID is authorized to access are based not only on the user as an individual, but the group in which the user is a member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a block diagram illustrating components of the present invention.
[0007] [0007]FIGS. 2 a - e illustrate in more detail a cross-referencing authorization data base of FIG. 1.
[0008] [0008]FIG. 3 illustrates in more detail a resource authorization data base of FIG. 1.
[0009] [0009]FIG. 4 is a flow chart illustrating operation and implementation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Referring now to the figures in detail, wherein like reference numbers indicate like elements throughout, FIG. 1 illustrates a computer system or network generally designated 10 according to the present invention. Network 10 comprises multiple clients 14 a, b, . . . n in the form of programmed personal computers or terminals, a common server computer 16 , a resource data base 17 , an authentication data base 20 , a cross-referencing authorization data base 22 and a resource authorization data base 24 . In the illustrated embodiment, the resource data base 17 is shown as being stored on a single, external disk drive, although the resource data base can be stored on multiple disk drives, external or internal to the server. The resource data base 17 may store data, computer programs or other resources. Each client 14 a, b, . . . n is operated by a respective (human) user 12 a, b, . . . n . The server can access any of the data bases 17 , 20 , 22 and 24 on behalf of a user. FIG. 1 also illustrates an authentication program 15 , an authorization program 19 and a resource management program 21 within the server 16 .
[0011] The authentication data base 20 includes an authentication table. The authentication table includes in a first column a list of IDs of (individual) users or groups, and in a second column a valid password for each ID. All IDs in the authentication system are typically associated with the name of the authentication data base such as the name of a corporation that issued the IDs. If a user submits a valid user ID and matching password from an authentication data base that the server recognizes, then the user is authenticated and can log-on or establish a session with server 16 .
[0012] [0012]FIG. 2 illustrates the cross-referencing authorization data base 22 in more detail. The cross-referencing data base includes tables 22 a - e storing IDs and ID related information for individuals and groups. By way of example, Table 22 a contains user ID information for selected individuals from IBM corporation. The first column of Table 22 a lists user IDs (including the authenticating data base name) for individuals, for example rsmith@IBM.com, tjones@IBM.com, and bjohnson@IBM.com. The second column of Table 22 a lists the corresponding user description including the user's name, organization and company. (In this example, the corporation is divided into different organizations, by location or department.) Table 22 a lists in the second column, Robert Smith from Main organization of IBM, Thomas Jones from Main organization of IBM, and Betty Johnson from Main organization of IBM. Thus, Robert Smith from Main organization of IBM is the user who submits user ID rsmith@IBM.com. Likewise, Thomas Jones from Main organization of IBM is the user who submits user ID tjones@IBM.com and Betty Johnson from Main organization of IBM is the user who submits user ID bjohnson@IBM.com.
[0013] Table 22 b contains group IDs and related information for various groups of individual users. The first column of Table 22 b lists group IDs (including the authenticating data base name), for example, Progroup from IBM and Tesgroup from IBM. The second column of Table 22 b lists the corresponding group description, including the name of the group, organization and company, for example, Programmer_Main_IBM meaning the Programmer group from Main organization of IBM. The third column of Table 22 b lists the descriptions of the individuals, by name, organization and company, who are members of the corresponding group. For example, Robert Smith of Main organization and IBM company, Thomas Jones of Main organization and IBM company and Betty Johnson of Main organization and IBM company are all members of the Programmer group.
[0014] Table 22 c contains additional user information for rsmith@IBM.com and user information for three additional individual users. Table 22 c has the same format as Table 22 a . The user descriptions from Table 22 c have different organization components than the user descriptions from Table 22 a . The user descriptions from Table 22 c include an Elm or Oak component whereas the user descriptions from Table 22 a all include a Main component. It should be noted that the same user ID, rsmith@IBM.com appears in both Tables 22 a and 22 c and represents the same person, although the user description recorded in the second column of each table is different. Table 22 a lists Robert Smith_Main_IBM whereas Table 22 c lists Robert Smith_Elm_IBM. As explained in more detail, in the illustrated embodiment of the present invention, the entire user description forms an entry in the authorization data base.
[0015] Table 22 d contains additional group information for Progroup@IBM.com and group information for an additional group, Debgroup@IBM.com. Table 22 d has the same format as Table 22 b . The group descriptions from Table 22 d have different organization components than the group descriptions from Table 22 b . The group descriptions from Table 22 d include an Elm or Oak component whereas the group descriptions from Table 22 b include a Main component.
[0016] Table 22 e contains an additional user ID on a different system for Robert Smith and user information for one additional individual. Table 22 e has the same format as Table 22 a . The user descriptions from Table 22 e have different organization components than the user descriptions from Table 22 a . The user descriptions from Table 22 e include an Oak or North component whereas the user descriptions from Table 22 a include a Main component. It should be noted that the same person, Robert Smith, has a different user ID and user description in Table 22 e than in Table 22 a.
[0017] [0017]FIG. 3 illustrates the Resource Authorization data base 24 in more detail. The Resource Authorization data base includes a table indicating which user descriptions and which group descriptions are authorized to access which resources. The first column of the table lists the user descriptions and group descriptions and the second column lists the resources that each user description or group description is authorized to access. For example, Robert Smith_Main_IBM is authorized to access Customer data, Robert Smith_Elm_IBM is authorized to access Schedule data, Thomas Jones_Main_IBM is authorized to access Schedule data, Betty Smith_Main_IBM is authorized to access Finance data, ProGroup_Main_IBM is authorized to access Program Functions data, Programmer_Elm_IBM is authorized to access Program Requirements data, Debug_Oak_IBM is authorized to access Problem Report data, etc. Even though the individual members of each group are authorized to access the data available to the Group ID, the Resource Authorization table 24 does not include an index for each of the members of the group to the data accessible to their group. For example, even though Carol Parker_Elm_IBM is a member of the Programmer_Elm_IBM, Resource Authorization table 24 does not indicate that Carol Parker_Elm_IBM has access to the Program Requirements data. It should be noted that the Resource Authorization table does not include an index for user IDs or group IDs. Also, in the illustrated embodiment of the Resource Authorization table and the authorization program described below, access is based on the entire user description or group description, not just the user name or group name. However, if desired access could be based on the user name or group name without the organization component or the company component.
[0018] [0018]FIG. 4 illustrates the authentication program 15 (Steps 50 and 52 ) and authorization program 19 (Steps 56 , 58 , 60 , 62 , 68 , 70 , 80 ) within server 16 in more detail. User 12 a , acting through client 14 a , attempts to log-on or establish a session with the server 16 by entry of the ID and password of the user at the client along with an indication that a log on or session with the server is requested. The ID can be that of an individual or a group. However, in this first example, assume the ID is from an individual user, rsmith@IBM.com. (Step 50 ) In response, the authentication program 15 within server checks for this combination of user ID and password in the authentication table of data base 20 to determine if they match. (Step 52 ) (Other authentication techniques are also known and usable and are not considered part of the present invention. For example, a process involving a digital certificate can be used to indicate authenticity.) Assuming the user ID is authenticated, the user next requests access to a specific resource such as Program Requirements data. In response, the user ID is passed to the authorization program 19 along with the request for the specified resource. (Step 56 ) (It is also possible that the authentication program at this time can substitute another, unique ID for the ID that was submitted by the user. If so, the following explanation of the present invention applies to the substitute user ID.) The authorization program determines that the ID is a user ID. (Decision 58 ) Next, the authorization program reads the first column of tables 22 a,c,e , searching for this user ID. The authorization program will identify the first row of Table 22 a and the first row of Table 22 c . Table 22 a indicates that rsmith@IBM.com is the user ID for Robert Smith_Main_IBM and Table 22 c indicates that rsmith@IBM.com is the user ID for Robert Smith_Elm_IBM. (Step 60 ). Next, the authorization program 19 searches for any groups in which Robert Smith_Main_IBM or Robert Smith_Elm_IBM is a member. Thus, authorization program 19 next reads the third column of Tables 22 b and 22 d , searching for either of these user descriptions. Authorization program identifies the first row in Table 22 b for Programmer_Main_IBM, and the first row of Table 22 d for Programmer_Elm_IBM. (Step 62 ). It should be noted that the authorization program 19 did not identify the second row of Table 22 d for Debug_Oak_IBM because this group includes a different user description, Robert Smith_Oak_IBM, for the same person, Robert Smith. At this point, the authorization program has determined that the user ID rsmith@IBM.com is authorized to access data accessible to Robert Smith_Main_IBM, Robert Smith_Elm_IBM, Programmer_Main_IBM and Programmer_Elm_IBM.
[0019] Next, the authorization program searches down the Resource Authorization table to attempt to locate a row containing the name of the requested data (in the second column) and the descriptions of the users and groups (in the first column) identified in steps 60 and 62 . In the foregoing example, the entities identified in steps 60 and 62 are Robert Smith_Main_IBM, Robert Smith_Elm_IBM, Programmer_Main_IBM and Programmer_Elm_IBM and the requested data is Program Requirements. (Step 68 ) In the illustrated example, the authorization is found in the sixth row. Therefore, the authorization program concludes that the request by user ID rsmith@IBM.com to access the Program Requirements data should be granted (even though the entries in the Resource Authorization table for Robert Smith_Main_IBM and Robert Smith_Elm_IBM do not indicate authorization to access the Program Requirements data). Next, the authorization program notifies Resource Management Program 21 that the request by rsmith@IBM.com to access the Program Requirements data should be granted. (Step 70 ) Finally, the server downloads the Program Requirements data to the client 14 a so that the user 12 a can access the Program Requirements data.
[0020] Referring again to step 50 , assume in this next example that the user submits an ID of the user as an individual such as rsmith@IBM.com and then another ID of a group in which the user is a member, such as Debgroup@IBM.com. In response, the authentication program 15 within server checks for this combination of individual user ID and associated password and this combination of group ID and associated password in the authentication table of data base 20 to determine if both sets match. (Step 52 ) Assuming both sets match, the individual user ID and the group ID are considered authenticated.
[0021] Next, the user requests access to a specific resource such as Problem Reports data. (Step 56 ) For purposes of explanation, the handling of this request by the authorization program can be viewed as processing part of the request based on the individual user ID and processing the other part of the request based on the group ID to determine if either processing yields the requested authorization. The authorization program processes the part of the request based on the individual user ID, rsmith@IBM.com, in steps 60 , 62 , 68 and 70 as described above (when the individual user ID is submitted without any group ID). However, the processing of this part of the request based on the individual user ID will not yield authorization to access the Problem Reports data as explained above. However, the processing of the other part of the request based on the group ID in steps 80 , 68 and 70 will yield authorization to access the Problem Reports data, as follows. The authorization program reads the first column of tables 22 b,d searching for this group ID. The authorization program will identify the second row of Table 22 d . Table 22 b indicates that Debgroup@IBM.com is the group ID for Debug_Oak_IBM. (Step 80 ). Thus, the authorization program has determined that the group ID Debgroup@IBM.com is authorized to access data accessible to Debug_Oak_IBM, and none other. Next, the authorization program searches down the Resource Authorization table to attempt to locate a row where Debug_Oak_IBM is listed in the first column and the requested data, Problem Report data, is listed in the second column. (Step 68 ). (As explained above, pursuant to the submission of the individual user ID, rsmith@IBM.com, the authorization program also searched down the Resource Authorization table to attempt to locate a row where Robert Smith_Main_IBM, Robert Smith_Elm_IBM, Programmer_Main_IBM or Programmer_Elm_IBM is listed in the first column and Problem Report data was listed in the second column, but this was unsuccessful.) In the illustrated example, the seventh row lists Debug_Oak_IBM in the first column and the requested data, Problem Report data, in the second column. Therefore, the authorization program concludes that the request by the combination of user ID rsmith@IBM.com and group ID Debgroup@IBM.com to access the Problem Reports data should be granted and notifies Resource Management Program 21 . (Step 70 ) Finally, the server downloads the Problem Reports data to client 14 a so that the user can access the Problem Reports data.
[0022] Based on the foregoing, a system and method for determining which resources a user can access based on user IDs or group IDs have been disclosed in accordance with the present invention. However, numerous modifications and substitutions can be made without deviating from the scope of the present invention. For example, the Resource Authorization table could also be indexed by user ID and group ID instead of user description and group description. Also, other user IDs, groups of users and group IDs can and will be included in the tables of data base 22 . Therefore, the present invention has been disclosed by way of illustration and not limitation, and reference should be made to the following claims to determine the scope of the present invention.
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A method and system for authorizing access to resources requested by a first user. To begin the process, the first user submits an ID of the first user as an individual requesting access to one of the resources. The first user is also a member of a group comprising a plurality of individual users. A first table indicates at least one group of a plurality of individual users. A second table indicates which resources are accessible by which of the users and which resources are accessible by which of the groups. An authorization program compares the first user to entries in the first table to determine which group or groups the first user is a member. Next, the authorization program compares the first user and the group or groups in which the first user is a member to entries in the second table to determine which resources the first user is authorized to access. Thus, the resources that the user ID is authorized to access are based not only on the user as an individual, but the group or groups in which the user is a member. The user need submit only one ID of the user as an individual to access both sets of resources.
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FIELD OF THE INVENTION
The present invention relates to a method for manufacturing screen (or sieve tube) and welding apparatus thereof, particularly to a method for manufacturing screen made of filtering material including metal net by resistance spot welding or seam welding technology and welding apparatus thereof. It belongs to petroleum exploitation field.
BACKGROUND OF THE INVENTION
In petroleum and natural gas exploitation fields, in order to prevent sand in the oil-gas well from being brought to shaft or ground apparatuses together with oil-gas-water while sanding, in-well screen which could effectively filtrates oil-gas-water needed to be used. One hole in a segment of an in-well screen ranged from several decades to several hundred meters would destroy the whole sand protection in-well project. If the sand protection fails, normal production of the oil-gas well will be influenced or the oil-gas well will be discarded. Thus filter materials of screen thus need to possess the following comprehensive property: exactly controllable pore size, strong whole strength, flexibility, excellent corrosive resistance and high reliability.
At present, most of filter materials used to make premium screen are very expensive multi-layer sintered metal net. This multi-layer sintered metal net is porous filter material produced by vacuum welding technology. It is a composite made of multilayer metal net, metal fiber or metal powder and has better solderability. It can be welded by arc welding or plasma arc welding without leaks and guarantee the welding strength. However, the filter material has high factory cost, low productivity and its size is limited by vacuum welding apparatus.
Using metal net to take place of above-said sintered filter material will have high economic benefit. However, conventional welding technology has either low welding strength or leak phenomena (shrinkage hole phenomena) appears on welding parts of melt net. When using single-layer metal net as filter material of screen, welding pores will appear on arc welding parts. Therefore, single-layer metal net is fixed on base pipe of screen by way of mechanical fixing means (e.g. hem and compacting means etc). However, the strength and reliability produced by these methods are relative low.
Although the screen may be made of non-sintered multi-layer composite net, during welding, shrinkage hole phenomena of multi-layer compound net is more serious than single-layer metal net. At the same time, due to high thickness of screen and several-meter-long filter segment, series of difficulties are brought to welding procedure. Thus how to obtain high quality and low cost screen welded by way of welding method from metal net is one big problem in the field.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a method for screen manufacturing and welding apparatus thereof, which uses resistance spot welding or seam welding technology to directly combine metal nets and connect them to base pipe etc, so as to eliminate leakage hole phenomena occurring at welding part of metal net, and form a screen from multilayer metal net with improved sand control capacity and life time.
Second object of the present invention is to provide a method for screen manufacturing and welding apparatus thereof to improve welding quality of metal net and lower factory cost of screen by way of two-side one-point welding.
The method for manufacturing the screen provided by the present invention is achieved as follows: said screen at least comprise a base pipe with multiple penetrated holes on pipe wall, a filter sheath and a protection jacket with multiple leakage holes in pipe wall; wherein the filter sheath is placed on and covers the outside of the base pipe, and the jacket is placed on and covers the outside of filter sheath, and the welding method is as follows:
Step 10 wrapping the outside wall of a support sheath with a metal filter net and fixing the metal filter net to the outside of the support sheath by way of welding, such that the metal filter net completely covers all penetrated holes of the support sheath to form the filter sheath; Step 11 fixing said filter sheath to the outside wall of the base pipe and the filter sheath completely covering all penetrated holes of the base pipe; Step 12 putting said jacket round the outside of the filter sheath and fixing it to the outside of the base pipe, such that said jacket completely covers the outside surface of filter potion of the filter sheath.
The present invention also provides another screen manufacturing method, which comprises:
Step 20 rolling a metal filter net into cylinder and welding the metal filter net which is rolled into cylinder by way of welding to form the filter sheath; Step 21 fixing the filter sheath to the base pipe such that it completely covers all penetrated holes on the base pipe; Step 22 putting the jacket round the outside of the filter sheath, fixing it to the filter sheath such that the jacket completely covering the outside surfaces of the filter portion of the filter sheath. Also the present invention provides a welding apparatus for the screen, comprising: an electric welding machine and a screen drive unit. The electric welding machine at least comprises a basal body, an arm, an inner welding head and an outer welding head; the outer welding head is mounted on the basal body and can be driven to move up and down by outer welding head drive unit, the inner welding head is mounted on the arm corresponding to the outer welding head and when the outer welding head is moved in the direction to inner welding head, they press the filter sheath of the screen at the same position from their own sides respectively. The inner welding head and outer welding head are connected with welding power supply for supplying welding current to the part of the filter sheath of the screen to be welded. Al least a holder and a shifting unit are set on the screen drive unit. The holder thereof is used for clamping the filter sheath of the screen, and the shifting unit is used for moving the filter sheath of the screen along the welding direction.
The present invention utilizes resistance spot welding or seam welding technology to directly combine metal net. Actually the combination is to fix multilayer of metal net together and connect it with the base pipe etc, so as to eliminate leakage hole phenomena appeared on jointing parts of the metal net and form the screen with multilayer metal nets and improve sand-control and life time. In addition, the present invention uses direct welding method to improve the welding quality of the metal net and lower the factory cost of the screen.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structure schematic drawing of the screen of the present invention.
FIG. 2 is a structure schematic drawing of the filter sheath of the present invention.
FIG. 3 is a schematic drawing of welding apparatus for longitudinal seam welding of the filter sheath of the present invention.
FIG. 4 is a schematic drawing of position limitation supporter at the welding end of the arm of the present invention.
FIG. 5 is a schematic drawing of welding apparatus for circular seam welding of the filter sheath's ends of the present invention.
FIG. 6 is first schematic drawing of welding the filter sheath's end of the present invention.
FIG. 7 is second schematic drawing of welding the filter sheath's end of the present invention.
FIG. 8 is third schematic drawing of welding the filter sheath's end of the present invention.
FIG. 9 is a schematic drawing of another filter sheath of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The solution provided by the present invention will be better understood from following detailed description of preferred embodiments of the invention with reference to the drawings.
As shown in FIG. 1 , it shows the screen manufactured by the present invention, which comprises a base pipe 1 with multiple penetrated holes in pipe wall, a filter sheath 2 and a protection jacket 3 with multiple leakage holes in pipe wall; wherein the filter sheath 2 covers the outside of the base pipe 2 and the jacket 3 covers the outside of filter sheath 2 . And the detailed welding method is:
Step 1 wrapping the outside of a support sheath 22 with a metal filter net 21 and fixing the metal filter net 21 to the outside of the support sheath 22 by way of welding, so that the metal filter net 21 completely covers all filter holes of the support sheath 22 to form the filter sheath 2 ; Step 2 fixing the filter sheath 2 to outside of the base pipe 1 such that the filter sheath 2 completely covers all penetrated holes of the base pipe 1 ; Step 3 putting the jacket 3 around the outside of the filter sheath 2 and fixing it to the outside of the base pipe 1 , such that the jacket 3 completely covers outside surface of filter area of the filter sheath 2 .
Wherein above-presented metal filter net 21 is divided into filter net and diffusion net. The filter net has the function of filtration, whose mesh size determines filter precision. Generally, it is twill weave or plain weave and made of stainless steel. The diffusion net has the function of diffusing liquid and lowering liquid flow resistance, the mesh size of which is larger than that of the filter net. Generally the diffusion net is square-mesh net with mesh number 10-30, and fiber diameter is 2-5 times of filter precision. Lap-joint surplus of the filter net is 5-40 mm.
The most critical procedure during the process of welding the screen is to weld the filter sheath 2 , detailed description is as follows: As illustrated in FIG. 2 , firstly, welding the metal filter net 21 to form the filter sheath 2 , the detailed welding method thereof is as follows: a stainless steel tube is utilized as the support sheath 22 , of which a plurality of filter holes are opened. Rolling the metal filter net 21 around the outside wall of the support sheath 22 with multiple penetrated holes, such that the metal filter net 21 completely covers all filter holes of the support sheath 22 . When rolling, start end of the metal filter net 21 is fixed to the outside wall of the support sheath 22 by spot welding and then the support sheath 22 is rotated in one direction, making the metal filter net 21 to cover the outside wall of the support sheath 22 . Furthermore, in order to guarantee the quality of rolling step, when one segment of the metal filter net 21 is rolled, the rolled segments are welded to a whole to fix by spot welding.
Above-said rolling step can use relative rotation and friction on the friction surface by the gravity of the support sheath 22 to directly roll the metal filter net 21 around the support sheath. The detailed rolling method is as follows: flat the metal filter net 21 on an arc friction surface suited with the edge radian of the support sheath 22 and fix the start end of the metal filter net 21 to the support sheath by way of energy-storing spot welding or resistance spot welding. Use an rotation mechanism to drive the support sheath 22 to rotate in one direction so that the metal filter net 21 is plainly rolled on the support sheath 22 till the metal filter net 21 rolled on the support sheath 22 meets the design requirement. After the metal filter net 21 is tightly rolled, it is fixed to the support sheath by way of energy-storing spot welding or resistance spot welding. In order to improve the contact between the metal filter net 21 and the support sheath 22 , above-said friction surface can be an elastic surface. The friction surface comprises wearable surface, elastic body and support body. The friction surface is made from metal net to improve its abrasion resistance.
As shown in FIG. 3 , after rolling the filter sheath 2 , the longitudinal seam of the metal filter net 21 on the filter sheath 2 needs to be well welded. The detailed welding method is as follows: putting the filter sheath 2 around the welding apparatus 10 , which comprises of outer welding head drive device 101 and welding machine 102 etc. The welding machine 102 of the welding apparatus 10 is consisted of a welding power supply, an inner welding head 103 , an outer welding head 104 and an arm 105 . The inner welding head 103 is fixed on the arm 105 ; the inner welding head 103 and outer welding head 104 is one-to-one correspondence.
When welding, put the filter sheath around the arm 105 of welding apparatus 10 so that the inner welding head 103 can press the filter sheath from inside. The outer welding head 104 and the inner welding head 103 is driven to move toward each other, so that the outer welding head 104 presses the metal filter net welded on the outside wall of the filter sheath 2 . Thus the support sheath 22 and the metal filter net 21 shown in FIG. 2 are tightly pressed against each other on the weld point by the outer welding head 104 and the inner welding head 103 . The pressure is controlled in the range of 0.17-170 kgf/mm2, preferable about 17 kgf/mm 2 .
After tightly pressing the support sheath 22 and the metal filter net 21 at the welding point, the outer welding head 104 and the inner welding head 103 are supplied with welding current so that parts of the support sheath 22 and the metal filter net 21 which conduct the welding current are welded in a whole. The duration of the welding current is no more than 0.3 s;
After stopping supplying welding current, the outer welding head drive mechanism 101 of the welding apparatus 10 separates the inner welding head 103 and the outer welding head 104 from the filter sheath 2 . The stepping drive mechanism 106 drives the filter sheath 2 to move along its axial direction, so that the inner welding head 103 and the outer welding head 104 correspond to an un-welded position, then above-said welding procedure is repeated till the metal filter net 21 , which covers the outside of the support sheath 22 , finishes the whole welding along the axial direction of filter sheath 2 . When driving the filter sheath to move, each time the distance the filter sheath 2 moved should be no more than the size of weld point, so that all welded points are joined together to form the dense seams to guarantee welding quality.
In order to prevent oxidation caused by heat, when welding, water-cooling is used to rapidly lower the temperature. In addition, a circulation cooling system is placed in the arm to solve heat problem caused by high current continuous welding and bad ventilation condition of the cable.
As shown in FIG. 4 , since the filter sheath 2 has a certain length, the position limitation supporter 107 may be provided behind weld points of the arm 105 . When the outer welding head 104 tightly presses the filter sheath 2 toward the inner welding head 103 , the position limitation supporter 107 is utilized to support the outside wall of the filter sheath 2 , then further support the arm 105 so that the arm 105 will not be significantly deformed and thus the displacement will not appear between the inner welding head 103 located on the arm 105 and the outer welding head 104 . In addition, the position limitation supporter 107 may be V shape, U shape or other shapes which can prevent the filter sheath 2 from swinging and match with the edge of the filter sheath 2 .
Actually, above-said welding method may also use the pattern other than the pattern that the inner welding head 103 and the outer welding head 104 presses the filter sheath 2 from two sides. Alternatively, it is to use two welding heads to tightly press the outside wall of filter sheath 2 and then supply the instant welding current. This welding pattern may not use the above-said arm 105 ; however the welding quality is worse than the pattern that the inner welding head 103 and the outer welding head 104 press the filter sheath from two sides. In addition, when using the pattern that the inner welding head 103 and the outer welding head 104 press the filter sheath from two sides, the inner welding head 103 and the outer welding head 104 may use weld wheels to implement seam welding for the weld points.
When using above welding pattern that the inner welding head 103 and the outer welding head 104 press the filter sheath from two sides, the arm 105 may use non-magnetic metal so that the arm 105 can not only conduct current but also stabilify the welding current. The problem of serious heat of the filter sheath 2 and arm 105 can also be avoided.
When welding one weld point is finished, the pressure acted on the filter sheath 2 by the gravity of the arm 105 may not be eliminated. Hereby the motion resistance of the filter sheath 2 will be very heavy, thus the filter sheath 2 can't move. If the filter sheath 2 is strongly pushed, it will be scuffed or pushed uniformly. Therefore, it is appreciated that the arm 105 has upward force so that the motion of the filter sheath 2 will not be influenced.
As shown in FIG. 5 , after the longitudinal seam is well welded, circular seam of two ends of the filter sheath 2 is also needed to be welded, the concrete welding pattern is still spot welding, and the procedure of welding is as follows:
At first, the filter sheath 2 is set on the welding apparatus 10 which comprises the outer welding head drive mechanism 101 , the welding machine 102 etc; wherein the welding machine 102 of the welding apparatus 10 is consisted of welding power supply, the inner welding head 103 and the outer welding head 104 . The inner welding head 103 is mounted on the internal arm and is one-to-one corresponding to the outer welding head 104 . The holder 109 for holding the filter sheath is placed on the stepping drive mechanism 106 , and is driven to rotate by the stepping drive mechanism 106 .
When welding, the inner welding head 103 inside the filter sheath 2 and the outer welding head 104 outside the filter sheath 2 press against each other at the same end of the filter sheath 2 , so that the support sheath 22 and the metal filter net 21 shown in FIG. 2 are tightly pressed at weld point. The pressure is controlled in the range of 1.17-170 kgf/mm2, preferably about 17 kgf/mm 2 .
The inner welding head 103 and the outer welding head 104 are supplied with welding current no more than 0.3 s so that the support sheath 22 and the metal filter net 21 are arc welded in a whole at weld points. After stopping supplying welding current, the outer drive mechanism 101 of the welding apparatus 10 separates the inner welding head 103 and the outer welding head 104 from the filter sheath 2 and rotates them along axis center of the filter sheath 2 to locate the inner welding head 103 and the outer welding head 104 to an un-welded position of the end. Above-said welding procedure is repeated till the metal filter net 21 which covers the support sheath 22 finishes the whole welding along circular outside of end of the filter sheath 2 . When driving the filter sheath 2 to rotate, each time the distance that the filter sheath 2 rotated should be no more than the size of weld point, so that all welded points are joined together to form the dense welding seams to guarantee welding quality. In order to prevent the oxidation of weld points caused by heat, when welding, using water-cooling to rapidly lower the temperature around weld points.
As shown in FIG. 1 and FIG. 6 , in order to intensify the welding current for improving welding strength, a plurality of protruding parts or grooves 24 may be set on the welding position of the end of the filter sheath 22 , which can improve the sand control capacity and are convenient for machining operation and also can enlarge the welding current of weld points. In order to guarantee all weld points with enough welding strength, the size of every weld point ranges in 1-10 mm×1-10 mm, preferably no larger than 3 mm*4 mm.
In order to get more reliable quality in the case where the filter sheath 2 is engaged with the base pipe 1 , when welding the filter sheath 2 , the end of the metal filter net 21 is welded to a welding ring 4 for resistance welding. After one cycle of resistance welding is finished along the end of the metal filter net 21 , implement arc welding so that the metal filter net 21 and welding end form melting welding line 25 . In order to improve sand control reliability of the end, joint of the welding line 25 and the weld ring of the end uses electric arc welding to weld. The weld points by arc welding is also smooth, flat and convenient for checking as well as the problems of contraction of the metal filter net 21 and shrinkage hole caused by the arc welding will not appear.
When the filter sheath 2 and the base pipe 1 are to be fixed to each other, at first, the filter sheath is placed on and the base pipe 1 and covers all penetrated holes of the whole base pipe 1 , and then the end of the filter sheath 2 and outside wall of base pipe 1 are welded in a whole by way of welding. When welding, electric arc welding method may be used. After fixing the filter sheath 2 to the base pipe 2 , the jacket 3 with multiple penetrated holes is placed around the outside of the filter sheath 2 with the jacket 3 completely covering the filter sheath 2 .
The filter sheath 2 is placed on the base pipe 1 and covers all penetrated holes on the whole base pipe 1 , and then the end of the filter sheath 2 and outside wall of base pipe 1 are welded in a whole. In order to save factory cost and simplify manufacturing procedure, the support sheath 22 inside the filter sheath 2 is not adopted. Hereby the procedure of placing the filter sheath 2 on the base pipe 1 may skip, thus further reduce the manufacturing procedure, save materials and lower factory cost.
In order to lower destroy possibility when the filter sheath 2 is on the status of working in well, the jacket 3 is needed to be set outside of the filter sheath 2 . The jacket may be made of stainless steel material by welding, e.g. the stainless steel pipe with multiple penetrated holes. The stainless pipe is place on and covers the outside of the filter sheath 2 and is fixed to the base pipe by way of electric arc welding to form the whole screen.
As shown in FIG. 7 and FIG. 8 , in order to prevent leakage hole phenomena when welding the metal filter net 21 to the end welding ring 4 , implementing spot welding and then implementing electric arc welding. Also in order to improve the welding quality of the electric arc welding, filler wire may be used to implement the final whole welding. The detailed procedure is initially fixing the welding wire to the part to be welded, and then melting it by way of electric arc welding so that the welding wire and the metal filter net 21 are engaged together, as well as the metal filter net 21 and the end welding ring 4 are engaged together. The welding wire filled in the part to be welded may use tabular wire or rectangular wire. Since the tabular wire or rectangular wire is difficult to roll, and possess better positioning property, thus it is convenient for positioning by the resistance welding.
As shown in FIG. 8 , it also may use a hoop 6 to achieve connecting the metal filter net 21 with the end welding ring 4 . That is, the hoop 6 is placed on and covers the end of the metal filter net 21 and the metal filter net 21 is placed on and covers the outside of the end welding ring 4 , then the metal filter net 21 and the end welding ring 4 are fixed together by the hoop 6 . Thus When using welding or part welding to connect, the welding strength is improved. In order that the end welding ring 4 can be well welded together with the filter sheath 2 , welding material i.e. filler wire 41 may be filled in a welding circular seam 26 which is located at the connection ends of the end welding ring 4 and the filter sheath 2 in advance. When welding, the filler wire 41 is melted down by the welding current, so that the end welding ring 4 and the filter sheath 2 are melted in a whole to form circumferential weld points or welding ring. Another approach for the end welding ring 4 to be well welded with the filter sheath 2 in a whole is fixing the connection ends of the end welding ring and the filter sheath 24 by using the hoop 6 . In order to get better connection quality, the filler wire 5 is filled between the hoop 6 , the end welding ring 4 , and the end welding ring 4 , then the hoop 6 and the filter sheath 2 are welded in a whole by way of electric arc welding.
As shown in FIG. 9 , in another case where the filter sheath 2 of the screen doesn't use the support sheath. As an alternative, rolling the metal filter net 21 in to cylinder to form the filter sheath 2 , and detailed welding method is as following: the screen at least comprises base pipe 1 , filter sheath 2 and jacket 3 with multiple holes. The filter sheath 2 is placed on and covers the outside of the base pipe 1 with all penetrated holes on the base pipe 1 completely covered. The jacket 3 covers the outside of the filter sheath 2 with the filter portion of the filter sheath 2 completely covered. The detailed welding procedure thereof is as following:
Rolling the metal filter net into cylinder and welding the metal filter net 21 which is rolled into cylinder along its axial direction to form the filter sheath 2 by way of welding. Then putting the jacket 3 around the outside of the filter sheath 2 and fixing it to the filter sheath 2 with the outside of filter part of the filter sheath 2 completely covered.
Concretely speaking, it is to weld one end of the metal filter net 21 which is rolled into cylinder along its axial direction by way of spot welding, and then weld the end of the metal filter net 21 which is rolled into cylinder to form the filter sheath 2 .
As shown in FIG. 3 , when welding the metal filter net 21 along the axial direction, at first, the inner welding head 103 inside the metal filter net 21 which is rolled into cylinder and the outer welding head 104 outside the metal filter net 21 which is rolled into cylinder press against each other, so that each layer of the metal filter net 21 is tightly pressed at the weld points. Supply instant welding current by the inner welding head 103 and the outer welding head 104 , parts of each layer of the metal filter net 21 which conduct the welding current are welded in a whole by way of electric arc welding. Further separate the inner welding head 103 and the outer welding head 104 from the metal filter net 21 and move them along the axial direction of the metal filter net 21 which is rolled into cylinder, so as to place the inner welding head 103 and the outer welding head 104 to a position corresponding to an un-welded position. Above-said welding procedures are repeated till welding axial parts of the metal filter net 21 which is rolled into cylinder are completely finished.
As shown in FIG. 5 , it illustrates the filter sheath 2 formed from the metal filter sheath 21 which is rolled into cylinder. The method of welding the end of filter sheath 2 is as follows: at first, the inner welding head 103 inside the metal filter net 21 which is rolled into cylinder and the outer welding head 104 outside the metal filter net 21 which is rolled into cylinder press against each other, so that each layer of the metal filter net 21 is tightly pressed against each other at the weld points. Supply instant welding current by the inner welding head 103 and the outer welding head 104 , parts of each layer of the metal filter net 21 which conduct the welding current are welded in a whole by way of electric arc welding. Further separate the inner welding head 103 and the outer welding head 104 from the metal filter net 21 and rotate along the axial center of the metal filter net 21 which is rolled into cylinder, so as to place the inner welding head 103 and the outer welding head 104 to a position corresponding to next un-welded end position. Above-said welding procedures are repeated till welding the metal filter net 21 which is rolled into cylinder is completely finished along circular outside of its end.
Finally, the filter sheath 2 is welded onto the base pipe 1 , and the jacket 3 covers the outside of the filter sheath 2 with filter area of the filter sheath 2 completely covered, and then the jacket 3 and the base pipe 1 are welded together.
It should be understood that the above embodiments are used only to explain, but not to limit the present invention. In despite of the detailed description of the present invention with referring to above preferred embodiments, it should be understood that various modifications, changes or equivalent replacements can be made by those skilled in the art without departing from the spirit and scope of the present invention and covered in the claims of the present invention.
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The present invention relates to a method for manufacturing a screen and welding apparatus thereof, putting a metal filter net around the outside of a support sheath and fixing the metal filter net to the outside of the support sheath by way of welding, such that the metal filter net completely covers all filter holes of the support sheath to form a filter sheath with; fixing the filter sheath to the outside of the base pipe and the filter sheath completely covering all penetrated holes on the base pipe; putting a jacket around the outside of the filter sheath and fixing it to the outside of the base pipe such that the jacket completely covers the outside surface of the filter area of the filter sheath. The present invention uses direct spot welding and seam welding technology to fix the metal net to the outside of the support sheath directly, eliminates leakage hole phenomena appearing on jointing parts of the metal net and forms the screen with multi-layer metal nets with improved sand control capability and life time. The present invention also discloses the apparatus for above-said screen to realize penetrated welding of the filter sheath so as to improve the welding quality of the metal net and lower the factory cost of the screen.
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TECHNICAL FIELD
This invention pertains to the handling of continuous strips of asphaltic material, such as asphaltic material suitable for use as roofing membranes and roofing shingles. In one of its more specific aspects, this invention relates to the cooling of the asphaltic strip material in the production process.
BACKGROUND OF THE INVENTION
A common method for the manufacture of asphalt shingles is the production of a continuous strip of asphaltic shingle material followed by a shingle cutting operation which cuts the continuous strip into individual shingles. In the production of asphaltic strip material, either an organic felt or a glass fiber mat is passed through a saturator, containing liquid asphalt at a very hot temperature, to form a saturated asphaltic strip. Subsequently, the hot asphaltic strip is passed beneath a granule applicator which applies the protective surface granules to portions of the asphaltic strip material. In conventional shingle processes, the hot asphaltic strip material is next directed toward a cooling section where the asphaltic strip is held in the form of numerous loops. The cooling section of existing processes acts as an accumulator or temporary storage means for the asphaltic strip prior to shingle cutting and packaging. The asphaltic strip is maintained in the cooling section for a short period of time during which the asphaltic strip is cooled by the effects of the factory air acting on the loops. Some production processes provide for fans for blowing factory air through the loops, in a direction generally parallel to the lengths of material in the loops, and generally perpendicular to the machine direction of the shingle production machine. Some production processes use a water spray to wet the asphaltic strip prior to the blowing of air through the loops.
One of the problems associated with existing shingle production processes is that during the summer months, when factory air is at elevated temperatures and can be well over 100° F., the cooling section is insufficient to cool the asphaltic strip to the degree required for proper cutting and packaging of the shingles. This is especially true in relatively warm climates, such as the southern portion of the United States. The problem of inability to cool the shingle can also be bothersome in cool weather because outside cooling air applied to the asphaltic strip can evaporate and hold much less moisture than warm air can. If the asphaltic strip is too hot, the shingle cutting operation is adversely affected. Also the shingle packaging operation becomes less efficient when the shingles are too hot, and hot shingles become a greater fire hazard once they are packaged. Also, it is desirable to avoid packaging wet shingles. As new technology is applied to existing shingle production facilities, the speed with which the continuous asphaltic strip can be produced is increased. Thus, it has been found that in many cases the limiting factor in increasing the speed and the efficiency of a shingle production machine is the ability to cool and dry the asphaltic strip prior to cutting and packaging.
One of the attempts to solve the problem of cooling asphaltic strip material is disclosed in U.S. Pat. No. 2,365,352, to Moffitt. Moffitt describes a continuous asphaltic strip production process in which the cooling section contains a single water spray means for spraying water onto the loops of shingles as the loops are formed in the cooling section. Moffitt also provides for blowing cooling air through the loops, in a direction parallel to the strip material, while the loops are in the cooling section. Moffitt's solution to the asphaltic strip cooling problem is disadvantageous in that the air flow is not perpendicular or normal to the asphaltic strip material and is, therefore, relatively inefficient. The relatively inefficient nature of Moffitt's cooling system necessitates a rather lengthy cooling section in the machine direction. Also, in part due to the inefficiency of the air flow, Moffitt's system requires an enclosed cooling section, which greatly increases the capital expense of the apparatus.
A cooling system proposed for solving the above problem of cooling asphaltic strip material provides for the use of repeated applications of spraying an evaporative liquid such as water onto the asphaltic material, with each application of evaporated liquid being followed by air jets impinging onto the asphaltic strip material in a direction normal to the strip material to evaporate the liquid, thereby cooling and drying the strip material. This proposed cooling system for cooling strip material is highly dependent on temperature and humidity conditions of the air being impinged upon the strip material. The higher the relative humidity of the air used to evaporate the liquid, the greater the difficulty in obtaining substantially complete evaporation of the liquid. Also, colder air is able to hold less moisture than warm air, and thus, the temperature affects the evaporation of the liquid. There is a need for a method and apparatus for cooling asphaltic strip material in which the ability of the air jets impinging on the asphaltic strip material to evaporate the liquid on the strip material is taken into account.
SUMMARY OF THE INVENTION
According to this invention, there is provided a method for cooling a continuously moving strip of asphaltic material comprising subjecting the asphaltic material to a plurality of cooling cycles, each cooling cycle comprising spraying evaporative liquid onto the asphaltic material from a means for spraying and evaporating the evaporative liquid immediately downstream from the means for spraying by causing gases to impinge on the asphaltic material substantially normally to the asphaltic material, and further sensing the surface moisture of the asphaltic materials subsequent to one or more of the cooling cycles, and modifying the flow of evaporative liquid sprayed in one or more of the cooling cycles in response to the sensed surface moisture.
In a preferred embodiment of the invention, the surface moisture is sensed subsequent to all of the cooling cycles.
In a more preferred embodiment of the invention, the flow of the evaporative liquid is sequentially stopped or decreased in order beginning with the furthest downstream of the cycles toward the furthest upstream of the cycles, in response to the sensed surface moisture.
According to the this invention, there is also provided a method for cooling a continuously moving strip of asphaltic material comprising subjecting the asphaltic material to a plurality of cooling cycles, each cooling cycle comprising spraying evaporative liquid onto the asphaltic material from a means for spraying and evaporating the evaporative liquid immediately downstream from the means for spraying by causing gases to impinge on the asphaltic material substantially normally to the asphaltic material, and further sensing the temperature of the asphaltic material subsequent to one or more of the cooling cycles, and modifying the flow of evaporative liquid sprayed in one or more of the cooling cycles in response to the sensed temperature.
In a preferred embodiment of the invention, the flow of evaporative liquid is sequentially started or increased in the order beginning with the furthest upstream of the cycles toward the furthest downstream of the cycles, in response to the sensed temperature.
According to this invention, there is also provided apparatus for cooling a continuously moving strip of asphaltic material comprising means for directing the asphaltic material into a plurality of loops, and a plurality of cooling units, each of the cooling units being associated with one of the loops, and each cooling unit comprising spraying means positioned to spray evaporative liquid onto the apshaltic material in the loop and air delivery means positioned immediately downstream from the spraying means and adapted to cause gases to impinge on the asphaltic material substantially normally thereto to evaporate the evaporative liquid from the asphaltic material in the loop, and further including means for sensing the surface moisture of the asphaltic material downstream from one or more of the cooling units, and means for modifying the flow of evaporative liquid sprayed in one or more of the cooling units in response to the sensed surface moisture.
In a preferred embodiment of the invention, the means for sensing the surface moisture is positioned downstream from all of the cooling units.
According to this invention, there is also provided apparatus for cooling a continuously moving strip of asphaltic material comprising means for directing the asphaltic material into a plurality of loops, in a plurality of cooling units, each of the cooling units being associated with one of the loops, and each cooling unit comprising spraying means positioned to spray evaporative liquid onto the asphaltic material in the loop and air delivery means positioned immediately downstream from the spraying means and adapted to cause gases to impinge on the asphaltic material substantially normally thereto to evaporate the evaporative liquid from the asphaltic material in the loop, and further including means for sensing the temperature of the asphaltic material downstream from one or more of the cooling units, and means for modifying the flow of evaporative liquid sprayed in one or more of the cooling units in response to the sensed temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view in elevation of apparatus for producing asphaltic strip material according to the principles of this invention.
FIG. 2 is a schematic cross-sectional view in elevation of the cooling section of the production machine of FIG. 1.
FIG. 3 is a schematic vertical section on line 3--3 of FIG. 2.
FIG. 4 is a perspective view of an air delivery means according to the principles of the invention.
DESCRIPTION OF THE INVENTION
As shown in FIG. 1, base sheet 10, which can be an organic felt or a glass fiber mat, is passed through saturator 12 containing liquid asphalt to create continuous hot strip 13 of asphaltic material. The hot asphaltic strip can then be passed beneath granule applicator 14 which applies the surface coating granules to a portion of the asphaltic strip. Subsequently, the asphaltic strip is passed through cooling section 16 where it is cooled and dried. Within the cooling section, the asphaltic strip can be directed by upper pulleys 18 and lower pulleys 20 into a plurality of loops having lengths L and widths W. Preferably, the lengths are generally vertical. After passing through the cooling section, the cooled and dried asphaltic strip can be directed into temporary storage looper 22 which accumulates the asphaltic strip prior to its delivery to shingle cutter 24, and packaging operations, not shown.
As shown in FIG. 2, an initial means for applying water to the asphaltic strip as it enters the cooling section, such as nozzle 25, can be positioned at the entrance of the cooling section. The water from this nozzle flashes to steam during normal operation due to the high temperature of the asphaltic strip. Spraying means, such as nozzles 26a through 26h, are positioned upstream from various ones of the vertical lengths of the loops for spraying an evaporative liquid, such as water, onto the asphaltic material. As shown in FIG. 3, the spraying means can be comprised of a series of three nozzles positioned across the width of the continuous strip of asphaltic material. The nozzles are supplied from a source of evaporative liquid, not shown.
Positioned immediately downstream from each of the nozzles 26a through 26h are air delivery means 30a through 30h for evaporating the water on the strip material immediately downstream from each of the nozzles. As can be seen in FIGS. 2 and 3, associated with each loop is a cooling unit comprised of a set of nozzles for spraying water immediately followed by an air delivery means for evaporating the water. Thus, a series or plurality of cooling units carries out a plurality of cooling cycles on the strip material, each cycle having a water spraying step immediately followed by an evaporation step.
Each of the air delivery means is comprised of a plenum defined by orificed plates 32 which are generally parallel to the lengths of asphaltic material in the loops. Preferably, the orifices in the plates are round, and deliver arrays of column-like air jets, although any flow of gases providing evaporation of the liquid will be suitable for purposes of this invention. Also, the orifices of the orificed plates preferably extend along the entire height of the plenums so that the arrays are supplied from the plenums over substantially the entire height of the loops, as shown in FIGS. 3 and 4. Air passing from the plenums through the orificed plates causes an array of air jets to impinge on the asphaltic material substantially normally to the lengths of asphaltic material. The impingement of the air jets in a direction normal to the surface to be cooled facilitates the rapid and efficient cooling of the asphaltic strip. Preferably, the impinging air jets supply air at a rate within the range of from about 60 to about 70 cfm per square foot of plenum surface.
As shown in FIGS. 2 through 4, the air can be supplied to the plenums by plenum conduits 34. The plenum conduits can be adapted with any means suitable for controlling the flow of air therethrough, such as dampers, not shown, in order to balance the force of the arrays of air jets impinging on opposite sides of the lengths. For example, the length of asphaltic material downstream from spray nozzle 26b, which is positioned between plenums 30b and 30c, is subject to the force of the arrays of air jets impinging thereupon from those two plenums.
Positioned downstream from all the cooling units is moisture sensor 36. The moisture sensor can be any means suitable for measuring the amount of surface moisture on the asphaltic strip material traveling past the moisture sensor. A moisture sensor which would be sufficient for purposes of the invention would be a Quadri-Beam Moisture Analyzer, Model 475 manufactured by Moisture Systems Corporation, Hopkinton, Mass.
Also positioned downstream from the cooling units is temperature sensor 38, which can be any temperature sensing device suitable for measuring the temperature of the asphaltic strip material traveling past the temperature sensor. A device suitable for purposes of the invention would be a Williamson Model 4200 Infrared Temperature Sensing device. Although the moisture sensor and temperature sensor are shown as being positioned immediately downstream from the cooling section, either the moisture sensor or the temperature sensor, or both, can be positioned immediately upstream from the shingle cutter while continuing to operate under the principles of this invention. The moisture sensor and temperature sensor can be wired to a controller in order to provide control for the cooling taking place in the cooling section. The controller can be any means suitable, such as a microprocessor, for receiving data from the sensors and modifying the water flow from the spray nozzles.
As shown in FIG. 2, some of the cooling units can be provided with additional moisture sensors, such as moisture sensors 40, 42 and 44. Moisture sensor 40, for example, measures the surface moisture on the asphaltic strip material after the strip material has passed through the cooling unit comprised of spray nozzles 26a and plenums 30a and 30b. All of the moisture sensors are connected to the controller by means, not shown.
In operation, the controller can be programmed to control the operation of the spray nozzles in response to all of the moisture sensors. Preferably, the controller is programmed to sequentially stop or decrease the flow of evaporative liquid sprayed from the spray nozzles, in the order beginning with the furthest downstream of the cooling units toward furthest upstream of the cooling units, in response to the sensed surface moisture of the sensors. It is preferable that no new cooling cycle be initiated if the asphaltic strip material emerging from the previous cooling cycle has not been substantially dried. Thus, for example, if moisture sensor 36 indicates wet asphaltic material, then the controller would decrease or stop the flow of water from nozzles 26h. Also, if moisture sensor 44 indicates that the asphaltic strip material is wet, then spray nozzles 26e are either stopped or reduced in flow of evaporative liquid.
In the preferred embodiment of the invention, the sensing and slowing or stopping of the flow of liquid from various cooling units is done in a sequential order in the reverse machine direction. This can be done regardless of the number of moisture sensors, provided that there is one moisture sensor positioned downstream from all the controlled cooling units. For example, if moisture sensor 36 indicates that the asphaltic strip material is not substantially dry, then spray nozzles 26h can be stopped. If the moisture sensor still indicates a wet asphaltic strip, then spray nozzles 26f, 26 g and 26h are turned off. In the event that stopping the flow of evaporative liquid from spray nozzles 26f, 26g and 26h is insufficient to provide a dry shingle as measured by moisture sensor 36, then spray nozzles 26e are turned off. Thus, the nozzles are sequentially turned off or slowed down in the reverse machine direction until a condition of a dry shingle is sensed by the moisture sensor. Therefore, this invention encompasses both the control of the entire cooling section by one moisture sensor, such as moisture sensor 36, and the control of individual cooling units by moisture sensors positioned immediately downstream from those cooling units, such as moisture sensors 40, 42, and 44.
The positioning of additional temperature sensors, not shown, following individual cooling units can be effected in a manner similar to the placement of additional moisture sensors 40, 42 and 44. In operation, the nozzles of the cooling units can be sequentially turned on in the machine direction in response to a condition of sensed temperature above a predetermined temperature, in order to cool the asphaltic material prior to its being cut into shingles.
INDUSTRIAL APPLICABILITY
This invention will be found to be useful in the continuous production of asphaltic strip material for such uses as asphalt shingles.
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A method and apparatus for cooling a continuously moving strip of asphaltic material includes directing the asphaltic material into a plurality of loops, spraying an evaporative liquid onto the asphaltic material, evaporating the evaporative liquid by causing an array of air jets to impinge on the asphaltic material subtantially normally to the asphaltic material, sensing the surface moisture of the asphaltic material subsequent to one or more of the loops, and modifying the flow of evaporative liquid sprayed in one or more of the loops in response to the sensed surface moisture.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The field of the present invention concerns the disinfection of biological materials and in particular concerns a novel use of an insolubilized organic detergent as a disinfecting agent.
[0003] 2. Description of Related Art
[0004] The present inventor has long been concerned with problems of blood borne infection. In particular, he has dealt with methods for disinfecting clotting factors and other proteins purified from blood. He has invented methods of disinfection involving iodine (see, for example, U.S. Pat. Nos. 5,360,605, and 5,370,869), and glycyrrhic triterpenoid and its derivatives (see, for example, U.S. Pat. No. 5,204,324). In addition, he was the inventor of a method of plasma protein purification employing “amphiphiles” which are more commonly known as detergents (see U.S. Pat. No. 4,314,997).
[0005] Literally amphiphile means a substance that has affinities “on both sides.” This refers to a material that is both hydrophilic (dissolves readily in water) and hydrophobic (dissolves readily in organics such as lipids). Because of its dual nature, such a material can be used to dissolve or emulsify fatty organic substances into an aqueous solution as in removing dirt from clothing. Generally, a detergent is a molecule that is lipophilic (hydrophobic) at one end and hydrophilic at the other end. The hydrophilic end may be hydrophilic by virtue of charged groups, either negative (anionic) or positive (cationic) or may be hydrophilic by virtue of polar but uncharged (nonionic) groups such as hydroxyl groups or oxygen atoms.
[0006] This dual hydrophobic/hydrophilic nature gives detergents or amphiphiles favorable properties in purification of therapeutic blood proteins although they may also denature proteins. Blood proteins can be contaminated with any of a number of disease organisms including viruses causing AIDS and hepatitis. Many important disease-causing viruses are composed of a nucleic acid core surrounded by a lipid membrane. It has been shown that detergents can be effective at inactivating viruses. It seems likely that this is due to the detergent emulsifying or otherwise disrupting lipid structures essential for viral activity. One real problem with detergents is that they are also capable of disrupting other vital lipid-based structures like the biomembranes that surrounds and form a significant internal structural component of every animal and plant cell. It turns out to be difficult to find detergents that are sufficiently active to disrupt infective agents while being gentle enough to spare living cells. As a result, huge numbers of detergent structures have been screened looking for optimal detergents. U.S. Pat. No. 4,314,997, mentioned above, gives a lengthy list of candidate detergents.
[0007] At the risk of simplifying a hugely complex area it can be considered that ionic detergents (either anionic or cationic) are the most active, and while being very effective at destroying viruses, may readily destroy or damage living cells. Generally, one way to overcome cell destruction is to lower the working concentration of the detergent. However, it is often the case that when the detergent concentration is sufficiently lowered to avoid cell damage, it is also too low to destroy viruses.
[0008] The nonionic (uncharged) detergents are generally less active at destroying or damaging cells. Hence it may be possible to find concentrations of nonionic detergents that destroy virus without excessively damaging cells. However, because these detergents are relatively less active, rather high concentrations of detergent are required to adequately destroy viruses. For example, U.S. Pat. No. 4,314,997 claims the broad concentration range of 0.25% to 10% by weight of a variety of detergents. However, the preferred concentration of one nonionic detergent, Triton X-100, is at least 2%, while other procedures may use even higher concentrations of detergent. It should be apparent that this may be a case of trading one difficulty for another. Triton X-100, like most detergents, is extremely harmful when injected intravenously. Therefore, removing detergents after they are used for disinfection becomes a very real and significant problem. This problem is merely exacerbated where an extremely high concentration of detergent is used, and especially when one considers that micellar characteristics make it difficult to remove Triton X-100 by dialysis.
[0009] One popular method of disinfecting blood products is the so-called “solvent detergent” process. In this process plasma viruses are inactivated by the addition of relatively high concentrations of detergents together with an organic solvent-tri-n-butyl-phosphate. The detergent and solvent are then removed by partitioning the protein solution against an organic liquid. The detergent and solvent partition into this liquid and are, hence, eliminated. Most often bland organic liquids such as castor or soy bean oil are used. The oil is then removed by hydrophobic chromatography. It is not difficult to imagine the time and expense of partitioning the plasma and of regenerating or replacing the chromatographic components. Therefore, there remains a significant need for a disinfecting method with the advantages of detergents but which the usual problems of detergent removal.
OBJECTS AND SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide an improved detergent-based method for inactivation of disease-causing organisms;
[0011] It is a further object of the present invention to provide an inactivation method which uses detergent in an easily removable form;
[0012] It is an additional object of the present invention to provide a novel disinfecting reagent in the form of a complex between a detergent and a detergent-binding material.
[0013] These and other objects are met in an inactivation method that employs a detergent such as nonionic, cationic or anionic detergents and preferably a “sugar detergent” such as octyl-glucopyranoside. This detergent is effective at inactivating pathogens even when bound by a solid support. Under these conditions the concentration of detergent free in solution is vanishingly low: probably well below one millimolar in concentration. Addition of insoluble detergent results in effective destruction of enveloped viruses in a variety of protein-containing solutions such as clotting factors or other proteins purified from human blood. Because the detergent is essentially entirely bound to a solid substrate, there is little or no difficulty in ensuring that the end product is detergent-free. Because the detergent is so bound, it causes essentially no damage to proteins, blood cells and other cellular material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide an improved way of disinfecting plasma and plasma proteins and other protein solutions by the use of insoluble detergents bound to organic polymers such as polystyrene.
[0015] While the present invention is functional with a wide variety of detergents including anionic detergents such as cholic and deoxycholic acids (bile acids), cationic detergents such as benzalkonium chloride, and nonionic detergents such as Triton X-100, the present inventor has discovered that surprisingly low concentrations of n-octyl-B-D-glucopyranoside (OG) are especially effective in viral and other pathogen inactivation. Levels of about 0.03% are effective at inactivating some viruses even in the presence of plasma proteins. This discovery forms the basis of copending application Ser. No. 08/785,984. This concentration of detergents represents the lower edge of the concentration range claimed in the prior art and represents an amount of detergent far below that actually used to disinfect plasma and plasma products. OG is a nonionic detergent, one of the “sugar detergents” so-called because its molecular structure consists of a sugar (glucose unit or glucopyranoside) with an attached straight carbon (octyl) chain. The numerous hydroxyl groups of the sugar provide the hydrophilic part of the detergent while the aliphatic carbon chain is strongly hydrophobic. A number of other analogous sugar detergents are currently known wherein the glucose group is replaced by other sugars or disaccharides while the aliphatic carbon chain is replaced by straight or branched aliphatic chains of various lengths. OG, insolubilized according to the present invention, has proven to be especially effective. Although OG is currently preferred, closely related sugar detergents based on mono or disaccharides with aliphatic chains of between 6 and 14 carbons are usable in the present invention. Some of the other sugar include: n-decanoylsucrose, n-decyl-β-D-glucopyranoside, n-decyl-β-D-maltopyranoside, n-dodecanoylsucrose, n-dodecyl-β-D-glucopyranoside, n-dodecyl-β-D-maltopyranoside, heptyl-β-D-glucopyranoside, heptyl-β-D-thioglucopyranoside, n-hexyl-β-D-glucopy-ranoside, n-nonyl-β-D-glucopyranoside, n-octanoylsucrose, n-octyl-β-D-glucopy-ranoside, n-octyl-β-D-maltopyranoside, and n-octyl-β-D-thioglucopyranoside.
[0016] Experiment # 1: Lytic Effect of Insoluble Detergent on Whole Blood
[0017] It is important that any treatment intended to inactivate microbes shows no adverse effects on proteins and cells. It is well-known that detergents can damage biomembranes. This is most readily seen in the case of red blood cells (RBC) where any membrane damage is readily visible as leakage of hemoglobin (hemolysis).
[0018] Two mL of Calbiosorb resin (plastic resin beads designed to absorb detergents from aqueous solutions) were placed in a conical centrifuge tube and dispersed in 10 mL of 5 mM OG dissolved in phosphate buffered saline (PBS). The resulting suspension was mixed for 30 min to ensure complete absorption of the OG. The beads were allowed to settle and the supernatant PBS removed by aspiration. When the supernatant PBS was shaken in a sealed tube, it showed essentially no foaming indicating that all of the OG had been absorbed by the resin.
[0019] Five mL of fresh whole blood were added to the tube containing the detergent-laden resin, and the tube was mixed until the resin was completely suspended in the blood. After 5 min incubation at room temperature, the tube was centrifuged at 2,000 rpm for 5 min. The centrifugation process caused the contents of the tube to separate into three distinct layers: red cell pellet at the bottom, plasma above the red cells, and beads floating on top of the plasma.
[0020] There was no hemolysis immediately visible indicating that the OG was so strongly bound to the resin that it was unable to affect the blood cell membranes. Over a ten day period the resin gradually sank into the plasma and eventually formed a layer above the red cells. After several days, there was some indication of hemolysis, but untreated cells also show limited hemolysis after several days. In any case this experiment indicates that a brief treatment with insoluble detergent (i.e., one day or less) causes no apparent harm to the blood cells.
[0021] Experiment # 2: Anti-Viral and Lytic Effect of Insoluble Detergent on Whole Blood
[0022] Two 10 mL aliquots of 5 mM OG and two 10 mL aliquots of 10 mM OG were prepared in distilled water. Each aliquot was added to 20 mL of Calbiosorb resin and the resin-OG mixture was incubated for 60 min at room temperature with occasional mixing to ensure uptake of the detergent by the resin.
[0023] Twenty five mL of whole blood (EDTA anticoagulated) was obtained via venipuncture of the inventor. To 20 mL of this blood 0.4 mL of a stock vesicular stomatitis virus (VSV) suspension was added (spiked blood). A similar amount of VSV was also added to 20 mL of cell culture solution to act as a medium control. This virus is a good model for easily inactivated enveloped viruses
[0024] The supernatant from the resin incubation was decanted and 10 mL of spiked blood was added to one 5mM batch of resin and to one 10 mM batch of resin. The medium control was treated in the same manner. The tubes were incubated at room temperature for 24 hr with samples taken at 60 min and 24 hr. The samples were analyzed by a virus end point assay (VEPA) and the titered results shown in Table 1.
TABLE 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Titer whole 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 blood control whole 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 10.0 blood 5 mM 60 min whole 4 4 4 4 4 4 4 4 4 4 4 4 1 0 0 8.9 blood 5 mM 24 hr whole 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 blood 10 mM 60 min whole 4 4 4 4 4 4 4 4 4 4 4 4 0 0 0 8.7 blood 10 mM 24 hr Medium 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 control Medium 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 5 mM 60 min Medium 4 4 4 4 4 4 4 4 4 1 0 0 0 0 0 6.8 5 mM 24 hr Medium 4 4 4 4 4 4 4 4 4 4 4 4 4 3 0 10.0 10 mM 60 min Medium 4 4 4 4 4 4 2 0 0 0 0 0 0 0 0 4.9 10 mM 24 hr
[0025] There was no evidence of hemolysis. This experiment indicates that the detergent is very tightly bound and is able to attack the virus only very slowly. This suggests that higher detergentibead ratios may be more effective by saturating the resin and allowing a more rapid anti-viral effect.
[0026] Experiment # 2: Higher Ratio Insoluble Detergent Inactivation of Vesicular Stomatitis (VSV) Virus
[0027] This experiment was carried out like the immediately previous experiment except that 0 mM (control), 10 mM, 25 mM, 50 mM, and 100 mM OG solutions were prepared in distilled water. Ten mL of each solution was added to 2 mL of Calbiosorb resin and incubated for 60 min as before. The supernatant from each tube was decanted and shaken to observe any foaming as an indication of free detergent. Only the 100 mM sample showed any free detergent indicating that the beads were saturated (or that 60 min incubation is insufficient for complete detergent binding).
[0028] To each aliquot of insoluble detergent-beads 10 mL of VSV-spiked whole blood was added. The blood and beads were mixed and incubated for 60 min at room temperature and then centrifuged to pellet the cells. There was no sign of hemolysis in any of the treatments. Samples were then taken for VEPA analysis as before. The tubes were mixed to resuspend the cells and resin. A second sample was taken at 24 hr and a third at 48 hr. No hemolysis was apparent at any time. The results are given in Table 2.
[0029] Interestingly, the resin density was affected by the detergent concentration. In the 10 mM, 25 mM and 50 mM samples the resin was at the top of the plasma after 30 min, but after about 90 min the resin had settled onto the red cell layer. In the 100 mM sample, the resin did not separate and the red cells did not pellet cleanly until after 4 hr had passed.
TABLE 2 Dilution: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Titer 60 min 0mM 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 (control) 10 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 25 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 1 0 9.6 50 mM 4 4 4 4 4 4 4 4 4 4 1 0 0 0 0 7.5 100 mM 4 4 4 4 4 4 4 4 4 0 0 0 0 0 0 6.6 24 hr 0 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 (control) 10 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 0 0 9.5 25 mM 4 4 4 4 4 4 4 4 4 4 3 0 0 0 0 7.9 50 mM 4 4 4 4 4 4 4 4 0 0 0 0 0 0 0 5.9 100 mM 4 4 4 4 4 4 2 0 0 0 0 0 0 0 0 3.5 48 hr 0 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 2 0 9.8 (control) 10 mM 4 4 4 4 4 4 4 4 4 4 4 4 4 0 0 9.5 25 mM 4 4 4 4 4 4 4 4 4 1 0 0 0 0 0 6.7 50 mM 4 4 4 4 4 4 2 0 0 0 0 0 0 0 0 3.5 100 mM 4 4 4 0 0 0 0 0 0 0 0 0 0 0 0 2.4
[0030] These results indicate that insoluble detergent can effectively destroy VSV even in the presence of whole blood. It would appear that the ratio of detergent to resin is critical. Higher amounts of detergent per amount of resin may increase the amount of reactive detergent or may result in somewhat weaker binding of detergent. On the other hand increasing the overall amount of resin may increase the reactive surface area and may also play a critical role in determining the optimal detergent/resin ratio.
[0031] Experiment # 3: Inactivation of Bovine Viral Diarrhea (BVD) Virus
[0032] This experiment was designed to test the effectiveness of insoluble detergent on inactivating BVD, an enveloped virus and a good model for other thick enveloped viruses such as HCV. The experiment was carried out exactly as Experiment #2, above. The results are shown in Table 3.
TABLE 3 Dilution: 1 2 3 4 5 6 7 8 9 10 11 12 Titer 60 min 0 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 (control) 10 mM 4 4 4 4 4 4 0 0 0 0 0 0 4.5 25 mM 4 4 4 4 4 4 2 0 0 0 0 0 4.9 50 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 100 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 24 hr 0 mM 4 4 4 4 4 4 2 0 0 0 0 0 4.9 (control) 10 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 25 mM 4 4 4 4 4 4 0 0 0 0 0 0 4.5 50 mM 4 4 4 4 4 4 0 0 0 0 0 0 4.5 100 mM 4 4 4 4 4 2 0 0 0 0 0 0 4.6 24 hr 0 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 (control) 10 mM 4 4 4 4 4 4 1 0 0 0 0 0 4.6 25 mM 4 4 4 4 4 4 0 0 0 0 0 0 4.5 50 mM 4 4 4 4 4 0 0 0 0 0 0 0 3.8 100 mM 4 4 4 0 0 0 0 0 0 0 0 0 2.5
[0033] These results indicate that like VSV BVD can be killed by insoluble detergent. However, BVD is more resistant than VSV and clearly responds better to higher detergent/resin ratios.
[0034] Experiment # 4: Effect of Increasing Available Surface Area of Resin
[0035] In this experiment a 100 mM solution of OG in distilled water was prepared. This time twice the volume (i.e., twice the reactive surface area) of resin (4 mL) was added and the mixture treated as above. There was no evidence of foam in the supernatant indicating that all of the detergent was bound by the resin. The insoluble detergent-beads were added to 10 mL of BVD-spiked blood as in the immediately previous experiment. Again, samples were taken at 60 min, 24 hr and 48 hr. This time, as shown in Table 4, the viral killing was significantly improved suggesting that having an increased surface area to present insoluble detergent to the contaminated blood results in improved results. There was no apparent increase in hemolysis as might be expected if this effect were caused by some increase in the concentration of unbound (solubilized) detergent.
TABLE 4 1 2 3 4 5 6 7 8 9 10 11 1'2 Titer Control 4 4 4 4 4 4 1 0 0 0 0 0 4.7 60 min 4 4 4 4 0 0 0 0 0 0 0 0 3.1 24 hr 4 0 0 0 0 0 0 0 0 0 0 0 1.0 48 hr 0 0 0 0 0 0 0 0 0 0 0 0 0
[0036] Table 5 shows the same experiment repeated using hydrophobic resin sold by Bio-Rad (BioBeads SM2, Catalog #152-3920) The results are essentially identical indicating that the source of hydrophobic resin is not critical.
TABLE 5 1 2 3 4 5 6 7 8 9 10 11 1'2 Titer Control 4 4 4 4 4 4 2 0 0 0 0 0 4.9 60 min 4 4 4 3 0 0 0 0 0 0 0 0 3.0 24 hr 4 1 0 0 0 0 0 0 0 0 0 0 1.1 48 hr 0 0 0 0 0 0 0 0 0 0 0 0 0
[0037] Experiment # 5. Insoluble Triton X-100
[0038] Calbiosorb resin has an extremely high affinity for Triton x-100. Therefore, insoluble Triton X-100 was prepared in a manner identical to that used for insoluble OG. The material was prepared using the proportions of 10 mL of 100 mM Triton X-100 added to 2 mL of the resin. After absorption of the detergent, the resin was removed from the supernatant as explained above under Experiment #2.
[0039] In an initial experiment 10 mL of whole blood was added to a tube containing 4.0 mL of the Triton-resin. The tube was mixed thoroughly and observed for hemolysis over a seven day period. There was no signs of hemolysis although addition of a similar amount of soluble Triton results in immediate hemolysis.
[0040] Ten mL of VSV spiked plasma (prepared as explained above) was added to a second tube containing 4.0 mL of Triton-resin. The tube was mixed for 60 min at room temperature and a sample was taken and analyzed by a viral end point assay. Results of the assay are shown in Table 6.
TABLE 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Titer Control 4 4 4 4 4 4 4 4 4 4 4 2 0 0 0 4.7 60 min 4 4 4 4 4 1 0 0 0 0 0 0 0 0 0 3.1
[0041] These results show that while Triton-resin is somewhat less effective against virus than the comparable OG-resin, there must be extremely avid binding of the detergent since there is no sign of hemolysis. This suggests that even higher levels of Triton-resin could be used to increase the virucidal effect without resulting in cell damage.
[0042] Experiment # 6: Binding of Additional Detergents
[0043] The above results can be readily extended to a wide range of detergents and resins. It is anticipated that certain detergents will prove to be more effective than others as disinfectants. Similarly some resins may prove more effective at binding particular detergents. Besides the simple hydrophobic-binding resin (e.g. specially prepared polystyrene), ion exchange resins appear to be especially effective at binding charged detergents. As expected, anion exchange resins effectively bind anionic detergents while cation exchange resins bind cationic detergents. In the case of ion exchange resins it is likely that two-fold binding takes place. The charged end of the detergent is bound by the ion exchange group while the lipophilic end of the detergent is bound by the hydrophobic matrix of the exchange resin. In this experiment 10 mM solutions of a number of detergents were made. Three non-polar (non-ionic) detergents (OG, Triton X-100 and Tween-20) were tested; two zwitterionic detergents (CHAPS (3-[(3-Chloramidopropyl)-dimethylammonio]-1-propanesulfanate) and CHAPSO, (3-[(3-Chloramidopropyl)-dimethylammonio]-2-hydroxyl 1-propanesulfanate), CalBiochem) were tested; five anionic detergents (caprylic acid, cholic acid, deoxycholic acid, sodium dodecylsulfate (SDS), and dioctyl sulfosuccinate (DSS)) were tested; and two cationic detergents (benzalkonium chloride (BC), and tetradecyltrimethylammonium bromide (TTAB)) were tested. It should be noted that cationic detergents of this type (quaternary ammonium salts) are noted for their germicidal properties. Binding to Calbiosorb (hydrophobic resin), Purolite (anion exchange resin) and polystyrene was tested. After incubating the detergent solution with the resin beads, the beads were removed and the supernatant examined for foaming presence (+) or absence (−) as an indicator of detergent presence as shown in Table 7.
TABLE 7 Detergent Type Calbiosorb Polystyrene Purolite OG nonionic − + + Triton X-100 nonionic − + + Tween-20 nonionic − + + CHAPS zwitterionic − + +/− CHAPSO zwitterionic − + +/− Caprylate anionic − + − Cholate anionic − + − Deoxycholate anionic − + − SDS anionic − + − DSS anionic − + − BC cationic − + +/− TTAB cationic − + +/−
[0044] These results show that, as expected, Calbiosorb is very good at binding a wide range of detergents. Although polystyrene would be expected to bind detergents by hydrophobic interactions, it was relatively ineffective in these experiments probably because the solid polystyrene beads used had insufficient surface area. The anion exchange resin was somewhat effective in binding anionic detergents. The binding of bile salt detergents (cholate and deoxycholate) is particularly interesting because these are natural biological detergents and would be expected to be safe and nontoxic. Preliminary experiments with cholestyramine resin as an insoluble binding agent for these materials have shown beneficial detergent effects (e.g. disruption of pathogens) with bound bile salts.
[0045] The experiments detailed herein disclose the unexpected discovery that detergent molecules bound to solid materials remain effective in destroying pathogens such as viruses. Hitherto this discovery it was thought necessary to add disinfecting concentrations (often very high) of detergent to a liquid to be disinfected. After sufficient incubation to maximally inactivate the pathogens, the detergent was removed by chromatography or by solvent extraction. In any case the incubation in high concentrations of detergent would damage or lyse cells making this type of pathogen inactivation inappropriate for liquids containing cells or cellular components (e.g., blood). Furthermore, the removal of detergent was often laborious, costly and often resulted in additional damage to the liquid being treated. Because traces of detergent are often very toxic these methods are generally inappropriate for vaccines or other injectable substances.
[0046] Experiment # 6: Bound Detergents as Intermediates
[0047] The fact that insoluble or bound detergents maintain many of the beneficial properties of the soluble material suggests that other insoluble substances might also exert useful effects. There are a number of germicidal or disinfectant molecules that are essentially insoluble. Typical is the germicide known as triclosan. This chlorinated material is essentially insoluble in water but is soluble in organic solvents and lipids. It is commonly used as a disinfectant additive in soaps and the like. Triclocarban is a similar material. Parabens (including methyl paraben) are water insoluble germicides used in cosmetics and like applications.
[0048] A 0.3% solution of triclosan was made in an aqueous solution of 2% Triton X-100. The normally insoluble triclosan was slowly dissolved under these conditions. Addition of triclosan to Triton X-100 appears to potentiate the antiviral effectiveness of the detergent. In one experiment a 100 mM solution of triclosan was made in 2% aqueous Triton X-100. Five mL of this material was added to 50 mL of plasma spike with EMC virus and incubated for 60 min at room temperature. Results of viral end point assay are shown in Table 8. The test material completely eliminated the virus. Triton alone is virucidal, but 0.2% Triton is not nearly effective as Triton plus triclosan.
TABLE 8 Di- lution 1 2 3 4 5 6 7 8 9 10 11 12 Titer Con- 4 4 4 4 4 4 4 2 0 0 0 0 5.6 trol Tri- 0 0 0 0 0 0 0 0 0 0 0 0 0 closan
[0049] Experiments then were undertaken which demonstrated that treating detergent absorbing beads either with triclosan-Triton solution or directly with finely divided triclosan resulted in the uptake of triclosan by the beads. When these beads were tested in viral assays in a manner similar to the insoluble detergent beads, they showed enhanced viral kill over detergent alone beads. At this time it appears that a combination of triclosan and detergent is superior to either component alone. It is hypothesized that the bound detergent somehow mobilizes the triclosan and makes it more available for killing. In any case the soluble concentrations of either detergent or triclosan (i.e., the actual amount in solution) is very low. These results strongly suggest that the combination of other hydrophobic, insoluble germicides and disinfectants (such as triclocarban and parabens) with detergents on a binding support would also be effective.
[0050] The present method employing insoluble detergents avoids most of the problems of the prior art. When the detergent is bound to an inert binding material such as polystyrene or polystyrene-based ion exchange resins, the concentration of detergent present in the solution is extremely low: too low to cause discernible foaming and too low to cause cell damage. Nevertheless, there is sufficient detergent to effectively inactivate pathogens. This result may seem counterintuitive. Without wishing to be held to any one explanation of the present invention the inventor suggests that the inactivation process may occur when virus or other pathogens come into physical contact with the detergent bound to the surface of the binding material. Since the detergent is unable to leave the binding material, it cannot accumulate in cellular membranes and damage them. The insoluble detergents of the present invention are ideal for inactivating pathogens in blood, blood fractions, other biologicals (e.g., antibodies and vaccines) as well as any other liquids where presence of pathogens is of concern such as liquid foods and beverages. The materials can be applied in a batch process where the insoluble detergents are mixed with the target liquid to effect pathogen inactivation. In the alternative, flow through methods (e.g. chromatographic methods) can be used where the target liquid is allowed to percolate through a bed or column of the insoluble detergent. In either case the quantity of insoluble detergent and the contact time can be readily adjusted to provide optimal inactivation of pathogens.
[0051] The current process has been demonstrated with a variety of detergents, and while sugar detergents are currently preferred, a wide variety of detergent molecules including charged (anionic, cationic, and zwitterionic) and noncharged (nonionic or nonpolar) detergents are suitable. The inert binding material can be any of a variety of substances. Currently polystyrene resins and similar plastics that bind detergent primarily through hydrophobic and van der Waal's interactions are preferred. Specially prepared materials result in enhanced detergent binding. Obviously other similar materials that bind detergent are within the contemplation of the present invention. In addition, charged detergents can be bound effectively by the appropriate ion exchange resin where binding is both by ionic interaction through the ion exchange group as well as hyrophobic through the bulk material of the resin.
[0052] Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims. The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.
[0053] The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In addition to the equivalents of the claimed elements, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention.
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A detergent such as nonionic, cationic or anionic detergents and preferably a “sugar detergent” such as octyl-glucopyranoside is rendered insoluble by being bound to an inert substrate. This detergent is effective at inactivating pathogens even when so bound. Under these conditions the concentration of detergent free in solution is vanishingly low: probably below one millimolar in concentration. Addition of insoluble detergent results in effective destruction of enveloped viruses in a variety of protein containing solutions such as blood, plasma, clotting factors or other proteins purified from human blood. Because the detergent is essentially entirely bound to the solid substrate, there is little or no difficulty in ensuring that the end product is detergent-free. Because the detergent is so bound, it causes essentially no damage to proteins, blood cells and other cellular material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an engine, and more particularly to an engine used for automobiles, which is capable of discharging the working gases after purification, and which is capable of strengthening the engine brake.
2. Description of the Prior Art
It is known that exhaust gases discharged from automobiles contaminate air and provide public hazards. However it is unavoidable to some extent to discharge gases containing impurities hazardous to human health under the known automobile engines because of the fact that no effective device is equipped for purifying the gases before discharging from the cylinders.
When the automobile runs down a slope it is customary to minimize the speed of the engine so as to transmit the rotation of the wheels to the engine, thereby slowing down the rotation of the wheels. This prevents the brake shoes from becoming overheated owing to the tight contact with the wheels.
Herein this braking method will be referred to as engine brake. Under the known automobile engine systems the engine brake is effected by reducing the rotating speed of the engine but often it is not sufficient to brake the car. However there is a case where a strong engine brake must be effected.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention is directed toward an engine capable of discharging gases from the cylinders after purification, and also achieving a strengthened engine brake.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiment are given by way of illustration only, since various changes and modifications within the spirits and scope of the invention will become apparent to those skilled in the art from this detailed description and drawings.
According to the present invention there is provided an engine used for automobiles, the engine comprising:
a gas outlet laterally produced in a side wall of the cylinder in which the piston is reciprocally moved, the gas outlet being on the level of the top surface of the piston reaching the lower dead center;
a mushroom-shaped valve movable in the gas outlet, the mushroom-shaped valve being adapted to open and close the opening of the gas outlet;
a gas purifying box including a gas filtering means, the gas purifying box being connected to the gas outlet through a duct;
an air cleaner case accepting the top portion of the gas purifying box;
a carburetor connected to the gas purifying box; and
a change-over valve case provided under the carburetor, the valve case including a fuel port communicating with the carburetor, an air introducing port produced at right angle to the axis of the fuel port and a change-over valve movable therein, thereby introducing the air present on and above the top surface of the piston reaching the lower dead center into the cylinder through the air cleaner case and the gas purifying box.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-section through an engine embodying the present invention;
FIG. 2 is a vertical cross-section on an enlarged scale showing the gas outlet;
FIG. 3 is a horizontal cross-section on an enlarged scale showing the gas outlet:
FIG. 4 is a vertical cross-section through the gas cleaning case shown in FIG. 1;
FIG. 5 is a horizontal cross-section showing the cleaning case;
FIG. 6 is a horizontal cross-section through the upper oil purifying box;
FIG. 7 is a vertical cross-section showing the change-over valve box; and
FIGS. 8 and 9 are cross-section showing the different aspects of operation of the change-over valve.
DETAILED DESCRIPTION OF THE INVENTION
There is provided a gas outlet 1 laterally fixed to each cylinder 2. The gas outlet includes a valve chamber 3 and a bore 4. The gas outlet 1 is fixed at a position at which the bore 4 is situated slightly above the top surface of a piston 38 when it comes down at the lowest position. The reference numeral 5 denotes a valve seat with which the head of a mushroom-shaped valve 6 comes into engagement. The valve 6 is normally biased toward the valve seat 5 by means of a spring 7, whose one end is fixed to the valve 6. The pressure of the spring 7 is adjusted by a nut 8 screwed to the shaft of the valve 6. The adjacent valve chambers 3 are communicated with each other through gas passageways 9. The reference numeral 10 denotes an exhaust gas outlet duct connected to the passageway 9 at one end, and to an air injector 11 at the other end.
The gas injector 11 is provided with a cylindrical air intake pipe 12. The gas injector 11 is open in a gas purifying box 13, that is, the air injector 11 is inserted through a bottom 14 of the box 13. The gas purifying box 13 is provided with a lower oil cleaner unit, which, in the illustrated embodiment, includes two cylinders 15 made of net. The reference numeral 16 denotes a dome-shaped oil distributor. In addition an upper oil cleaner unit 17 is provided, which also includes two cylinders 17 made of net. The gas purifying box 13 is provided with a covering dome 18, which has an opening 19 toward the upper oil cleaner unit 17. In this way the air purifying box 13 is unified with the upper and lower cleaner units and the covering dome 18, and as a unit the gas purifying box 13 is connected to an air cleaner case 20 in such a manner that the opening 19 is open therein as shown in FIG. 4. The air cleaner case 20 includes a cylindrical element 21 along its circumference.
There is provided a duct 22 leading from the air cleaner case 20 to a carburettor 23 of a known type, under which a change-over valve box 24 is provided. The change-over valve box 24 includes fuel supply ports 25 connected to the carburettor 23. A change-over valve 27 is rotatively provided in a bore 26, the change-over valve 27 being shaped like a truncated cone. The change-over valve 27 is provided with air-fuel supply paths 28 produced axially in parallel, the fuel-air paths each being connected to the fuel supply ports 25. There are provided air paths 29 laterally produced at right angle to the paths 28. A fuel and air are supplied through fuel-air supply ports 30 produced in the change-over valve box 24, the ports 30 being aligned with the fuel supply ports 25. The change-over valve box 24 is provided with air intake ports 31 inserted through a side wall thereof at a position where they communicate with the air paths 29. The air intake ports 31 include cleaning filter unit 32. The change-over valve 27 is normally biased toward the larger diameter side of its own (in FIG. 7, to the right). The valve 27 is provided with a stem 35 and a handle 34. The reference numeral 36 denotes an adjusting screw engaging the smaller diameter side of the valve 27.
The carburettor 23 is supplied with fuel through a pipe 37. The reference numerals 38, 39 and 40 denote a piston, an inlet manifold connecting between the change-over valve box 24 and the cylinder 2, an exhaust manifold connected to the cylinder 2, respectively. The used oil is returned through an oil return pipe 41 connecting the gas purifying box 13 with a cylinder case 42. The air cleaner case 20 is provided with an air sucking pipe 43.
An example of the operation of the invention will be described:
For the explosion stroke the conventional exhaust valve is designed to open before the crank reaches the lower dead center (at about 50°), thereby allowing the gases to escape from the upper exhaust valve.
Under the present invention the exhaust valve is deliberately opened at a slightly later point of time (about 45°) before the lower dead center than that under the known engine so that the explosion is completely finished, and after it returns to its original state the gases are discharged through the upper exhaust valve. In this way the piston 38 reaches a point near the lower dead point, and pushes the valve 6 against the spring 7. At this stage the gases present in an upper section above the piston 38 (the gases being in the stage of incomplete combustion) is introduced into the outlet 1, and enters the gas purifying box 13 through the exhaust gas outlet duct 10 at a pressure at which air is introduced into the air intake pipe 12. The air is ejected and diffused in the oil cleaner 15 where the oil content in the gases is removed. The gases continues to rise up and enter the upper oil cleaning cylinder 17 in which the remaining oil content is removed. The gases free from the oil enters the air cleaner case 20 through the opening 19, and admixes with the air introduced therein. The mixture is then supplied into the carburettor 23 through the duct 22. Then it is supplied to the cylinder 2 through the inlet manifold 39 through the fuel path 28 of the change-over valve 27 via the fuel supply port 25.
Then the handle 34 is moved in the direction of arrow by hand or foot or under the action of electromagnetism, thereby rotating the valve 27 at right angle. As a result the fuel path 28 is rotated at right angle from the position where it communicates with the air supply port 25 and the fuel/air supply port 30. One open end of the bore 28 communicates with the air introducing port 31 which is open toward the side of the valve case 24.
The port 29 produced perpendicularly to the fuel path 28 communicates with the air/fuel supply port 30 which is open in the undersurface of the valve box 24. As a result the air free from impurities is introduced into the fuel/air supply port 30, and synchronously with it the fuel supply port 25 is closed by the side wall of the valve 27, thereby stopping the supply of fuel. In this way the air introduced through the air introducing port 31 is caused to enter the cylinder from above the cylinder 2 at the ascent of the piston. Under the known engines part of the fuel/air mixture is discharged outside in the state of incomplete combustion, which provides pollution problems in the society. In addition, the known engines have a difficulty in discharging the whole gases from the cylinder because the inlet valve starts to open at a point where the piston reaches 6 to 10 before the upper dead center.
In contrast, according to the present invention the exhaust valve is opened at a slightly later point of time than under the conventional engines, where it would be about 50° before the lower dead center. After the explosition has been fully achieved the exhaust valve is opened, thereby discharging the gases from above. At this stage the incomplete combustion gases are withdrawn from the cylinder, thereby reducing the pressure acting on the piston. The gases is cleaned and returned to the air cleaner case 20 for circulation through the carburettor 23. When the brake is to be applied while the car is running, the handle 34 is simply shifted in the direction of arrow, thereby stopping the supply of fuel. This enables a large amount of air to enter the cylinder 2 through the air introducing port 31, thereby providing a pneumatic restraint upon the piston. An strengthed engine brake is achieved.
While the car is running the idling is automatically effected by returning the handle 34 to its original position.
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An engine used for automobiles, wherein the gases are discharged from the cylinder after purification, thereby reducing the air pollution problems, and the engine secures a strengthened engine brake by utilizing the pneumatic force as a restraint on the piston.
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BACKGROUND OF THE INVENTION
The present invention relates generally to water well production and, more particularly, to methods for increasing the production of water wells.
Currently, water well bores, bore holes, screens, casings and related downhole apparatus, as well as the geological formations surrounding them, are cleaned, refurbished or otherwise stimulated using an explosive charge. Well owners have traditionally held a guarded view with respect to use of dynamite, primacord, or a similar-acting explosive material, given the high potential for effect beyond the immediate concern. This approach is shared in situations involving wells owned, managed, or operated by municipalities or others who, in a similar fashion, hold the public trust. The uncontrollable nature of such materials often creates regulatory and liability concerns far beyond any attainable benefit.
Aside from the more obvious legal implications, the use of dynamite or related explosives is associated with a number of significant operational and overall efficiency concerns. Foremost among these is the estimation involved in choosing a charge equivalent to the force required to accomplish a desired goal. An over-estimation can result in unwanted and expensive well destruction, not to mention personal injury and other property damage. An initial charge estimated too low will necessitate time-consuming reloadings and repeated firings. The amplitude and frequency of energy released from the gas created will be dependent upon the charge selected. Invariably, the charge will be inappropriate for the stimulation required. Use of explosives by trial and error is ill-advised.
In summary, a considerable number of drawbacks and deficiencies exist in the art relating to water well production and stimulation. There is a need for a non-destructive and controllable method for increasing water well production.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a method for increasing water well production, overcoming the problems of the prior art, including those mentioned above.
It is an object of this invention to provide a method for improving and/or increasing water well production through use of percussive waveforms and mass displacement in a non-destructive manner.
It is an object of this invention to provide a method for stimulating water wells and surrounding geological formations through use of percussive waveforms which can be repeatedly generated as desired without withdrawal, removal, or reloading the waveform generator outside the well.
It is another object of this invention to provide a method for refurbishing water wells with downhole control and adjustment of waveform frequencies and energy content.
It is an object of the present invention to improve water well production through the engineering and design of waveform frequency and amplitude parameters to meet specific performance characteristics.
It is an object of this invention to provide a method for water well stimulation having higher rates of productivity.
It is an object of this invention to increase water well production through methods which provide field reliability and reproducibility.
These and other important objects, features and advantages of the present invention will be readily apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying examples and figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic partial cross-sectional view of a water well of the type with which the present invention can be used.
FIGS. 2A and 2B are partial cross-sectional views of a preferred percussive gas venting apparatus for use in conjunction and accordance with the present invention.
FIG. 3 is a graphic presentation relating and comparing energies and available energy sources.
FIG. 4 is a schematic partial cross-sectional view of a water well of the type with which the present invention can be used, showing in particular an electrical arc generator (54) which can be used alone or in combination with a gas gun (10), as well as video equipment (58) and bore diameter measuring equipment (60), each of which can be used alone or in combination with the other to monitor (56) the effect of waveforms and/or percussive energy without withdrawing apparatus from the well base.
SUMMARY OF THE INVENTION
This invention is a non-destructive method for increasing and/or stimulating water well production. The invention overcomes certain well-known problems and deficiencies, including those outlined above.
In part, the present invention is a method of stimulating water well production, including: (1) providing a water well with a bore volume; (2) inserting into the bore volume means for generating propagating pressure waveforms and mass displacement through the bore volume; (3) activating the generation means whereby impediments to well production are removed through interaction with the waveforms; and (4) adjusting the frequency of the activation and amplitude of the waveforms generated. The waveform generation means can include, but is not limited to, at least one percussive gas venting apparatus, at least one electrical arc generator, and combinations thereof.
In preferred embodiments, the waveform generation means is a percussive gas venting apparatus. The apparatus is activated to provide about 1-15,000 cubic inches of gas at a pressure of about 250-10,000 psi. In highly preferred embodiments of this inventive method, the apparatus provides about 10-1,000 cubic inches of gas at a pressure of about 500-3,000 psi. In preferred embodiments, the apparatus is activated at intervals of 1-120 seconds. In highly preferred embodiments, the interval of activation is about 3-100 seconds.
Alternatively, an electrical arc generator can be utilized to generate the pressure waveforms and mass displacement. Preferably, the arc generator is activated at intervals of 2-10 seconds. In other embodiments of invention, the wave generation means comprises two or more gas venting apparatus, or a combination of at least one gas venting apparatus and at least one electrical arc generator.
In part, the present invention is a non-destructive method of mineral, biological, and scale removal from the pump, casing, and screen apparatus and geological structure surrounding a water well, including: (1) inserting means for generating percussive energy into the bore of a water well; (2) initiating percussive impact within the well bore; (3) monitoring the removal of mineral, biological and/or scale deposits; and (4) adjusting the percussive energy whereby the mechanical action of the energy propagating within the bore and surrounding geological structure enhances apparatus performance and improves water production. The energy generation means is selected from the group consisting of at least one percussive gas venting apparatus, at least one electrical arc generator, and combinations thereof. In preferred embodiments, the energy generation means is a percussive gas venting apparatus which includes a high pressure gas gun. In highly preferred embodiments, the gas gun further includes a deflector to focus the percussive energy generated. Likewise, in highly preferred embodiments, the air gun includes at least one hold-off member to position the gas gun within the well bore.
A preferred percussive gas venting apparatus is initiated to provide the percussive impact of about 1-15,000 cubic inches of gas at a pressure of about 50-1,000 psi. In highly preferred embodiments of this method, a preferred gas gun provides about 10-1,000 cubic inches of gas at a pressure of about 500-3,000 psi. Likewise, in highly preferred embodiments, the percussive impact is initiated at intervals of about 3-100 second.
In part, the present invention is a non-destructive method of rehabilitating a water well by removing impediments to water production, including: (1) lowering into the bore of a water well means for generating percussive energy, the generating means including a high pressure gas gun; (2) initiating percussive impact within the well bore; (3) monitoring the removal of mineral, biological, and/or scale and related production impediments; and (4) adjusting the percussive energy whereby the mechanical action of the energy propagating within the well bore improves water production. In preferred embodiments, the gas gun includes a deflector to focus the energy generated.
As discussed above, the benefits associated with use of a non-explosive, non-destructive source of pressure waveforms and/or mass displacement include downhole control and increased production rate. Through use of a percussive gas venting apparatus, the propagated energy is directly related to the volume of the air vented and the pressure at which it is vented. Both parameters and their effect on the well system can be controlled, monitored, and adjusted without withdrawing the apparatus from the well bore. To that effect, water well production can be stimulated, refurbished, and/or increased through the isolated or repetitious impact of the percussive energy on pumping, casing, and screen apparatus, as well as the geological formation surrounding the well bore. With respect to the latter situation, the pressure waveforms and mass displacement of the water volume can be directed to clean and/or remove scale from the formations surrounding an uncased well bore. Likewise, the surrounding geological formation of sand and gravel pack wells can be modified to increase production. The invention can also be used to dislodge geological bridges across the well bore and, in a similar fashion aid in the extraction of pumps, lodged drilling tools, casings, and screens.
Generally, the displacement of the aqueous medium mass is best accomplished by the rapid deployment of pressure waveforms. Rapid venting at high pressure provides the energy required to remove impediments and increase water production. As described above, a percussive gas venting apparatus can be used effectively in this manner. Such apparatus include, without limitation, means to provide volumes of air downhole and vent it rapidly at high pressure. Gas compressors, tanks of pressurized gas, and other sources of gas volume can be used in conjunction with accessory equipment for the rapid deployment of the gas within the well bore and/or bore. Without limiting the present invention, venting apparatus include a high pressure gas gun coupled to a supply of pressurized gas. As described below, and well known in the art, one such gas gun is available under the BOLT trademark, from Bolt Technology Corporation. Equivalent gas guns, pressurized gas supplies, conduits, and related apparatus may be used with equal effect, without limiting the scope of the present invention.
Alternatively, alone or in combination with a gas gun or its venting equivalent, electrical arc generators can be used to effect a method of this invention. Such generators, commonly referred to as sparkers, operate in part through the vaporization of fluid contacting the generator. With respect to the present invention, an electrical source produces sufficient heat to generate steam, the expansion of which creates pressure waveforms and displaces the water mass throughout the bore volume. Sparkers are available from a number of sources well known to those skilled in the art. The waveform frequencies obtained therefrom are generally higher than those obtainable from high pressure gas guns. While empirical studies of band width and center frequencies are generally unavailable, the pulse obtained from a high pressurized gas gun is typically in the 50-200 Hz band, with sparkers in the 200 Hz to 1 KHz band. In practical terms, when used alone, sparkers can be effective in breaking up brittle scale. They can also be used in conjunction with one or more high pressured gas gun to provide a broad frequency spectrum specifically designed or engineered to achieve a target rate or volume of production.
With respect to use of preferred gas guns of the present method, the volume of gas and the pressure at which it is vented within the bore volume is limited only by the mechanical and practical considerations associated with the construction, design, and deployment of such equipment. For various efforts associated with water well maintenance and/or stimulation, volumes of 10-1,000 cubic inches of gas released at pressures of about 500-3,000 psi are sufficient. However, where certain use applications require higher volumes and/or pressures, such as in situations involving impeding structural or apparatus bridges, larger capacity guns can be provided by adjusting the chamber, size and effective air pressure. Using a plurality of gas guns permits waveform propagation and mass displacement to be tailored with respect to frequency and related wave parameters, either through sequential or intermittent activation, with or without the creation of standing waves. Preferably, and in conjunction with most use applications, the method of this invention contemplates waveform generation at intervals of about 1--120 seconds and, most preferably, at 3-100 seconds when a high pressured gas gun is utilized. Other useful waveform generators are capable of providing pressure waveforms at a faster rate and can thereby be used alone or in conjunction with the preferred gas guns to provide a frequency spectrum. For example, the sparkers described above can be activated at a rate as frequently as once per second. In preferred embodiments of the present invention, the activation time interval is about 2-10 seconds. With any venting apparatus used herewith, any limitation on impediment removal can be offset by repeated activation without withdrawal of the apparatus from the well bore. The necessity of adjustment and/or repeated activations can be gauged through use of monitoring equipment, including without limitation video cameras and calipers to track deviations in well bore diameter.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 schematically represents a partial cross-sectional view of water well/well bore 42, within which is positioned gas gun 10, a preferred percussive venting apparatus of the present invention. With reference to FIG. 2A, pressurized gas enters gun 10 through gas intake 12. The gas passes into upper chamber 14, across which is fitted the upper portion of shuttle 18 consisting of triggering piston 16. The lower portion of shuttle 18 comprises firing piston 20 which defines the upper limit of lower chamber 24. Shuttle passage 22 allows passage of gas from upper chamber 14 to lower chamber 24. Upon gas entry, the same pressure is developed in both upper chamber 14 and lower chamber 24. However, the surface area of triggering piston 16 is sufficiently greater than the surface area of firing piston 20, such that the net downward force on triggering piston 16 causes shuttle 18 to move downward until the surface of firing piston 20 contacts the perimeter of lower chamber 24.
With reference to FIG. 2B, initiation of air gun 10 includes activation of solenoid 26 and injection of high pressure gas between triggering piston 16 and upper chamber 14 through chamber passage 28. The sudden introduction of gas through solenoid 26 disrupts the equilibrium state of gun 10, causing shuttle 18 to move upward at a high velocity. Passage of firing piston 20 past ports 30 rapidly releases the gaseous volume of lower chamber 24. The electrical current operating solenoid 26 is provided through conduit 34. Waveforms 36 generated from the rapid, high pressure release of gas from lower chamber 24 propagate through the mass of water medium 38 within well bore 42.
As shown in FIGS. 2A and 2B, preferred embodiments of gas guns of the type utilized in accordance with the present invention can include one or more deflectors for the purpose of concentrating or focusing the percussive waveforms on a specific target or area within the well bore. As shown in FIGS. 2A and 2B, deflectors 32 are secured to gas gun 10 in a manner sufficient to withstand the waveform impact and permit them to function according to design. Deflectors or focusing members of the type shown in FIGS. 2A and 2B are especially useful in the removal of scale and mineral deposits from screened wells.
Likewise, as shown in FIGS. 2A and 2B, hold off members 40 are secured to conduit 34 in such a way as to position gas gun 10 within a well bore. As shown in the referenced figures, hold off members 40 can be dimensioned, arranged and configured symmetrically to centrally position gas gun 10. Alternatively, hold off members 40 can be dimensioned and arranged to decentralize gas gun 10 within a well bore. Without limiting the scope of this invention, hold off members 40 can also be situated in a stationary fashion within the well bore volume to permit vertical movement of gas gun 10 before and after operation, or between activations.
As shown schematically in FIG. 1, gas gun 10 is positioned within well bore/volume 42. The water well system of FIG. 1 includes casing 44 and casing perforations 46. With equal effect, however, the methods of this invention can be utilized in conjunction with water wells lacking a casing apparatus, such that the percussive energy initiated impacts geological structure formation 48, directly. As referenced above, gas gun 10 operates in conjunction with gas source 52, and solenoid 26 operates in conjunction with electrical source 50, which can be provided separately or in conjunction with gas source 52.
In FIG. 3, the energy generated by preferred gas guns of the present invention is compared to dynamite charges of the prior art. Based on the empirical data shown in FIG. 3, a 10 cubic inch air gun is equivalent in energy to 0.01 pounds of 60% dynamite; and an 80 cubic inch gas gun is equivalent to about 0.1 pounds of 60% dynamite. Downhole guns with a capacity of 1,000 cubic inches provide energy equivalent to about 1.0 pounds of 60% dynamite. FIG. 3 also compares the energy provided by a preferred electrical arc generator. As seen therein, sparkers provide energy approximately equal to a 5 cubic inch gas gun or about 0.003 pounds of 60% dynamite. The correlations provided in FIG. 3 confirm, on the basis of available and empirical data, that the non-destructive energy available through use of present invention is equivalent in terms of magnitude and volume to the energy available from explosive sources of the prior art.
While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention, in any manner. For example, using techniques well known to those skilled in the art, the percussive impact of the waveform energy can be used in conjunction with injection of various fluids, solvents, and reagents suitable for use in the presence of water sources to increase mechanical agitation. Furthermore, steam can be utilized as a compressed gas at temperatures and contact times beyond the tolerable limits of biologicals, which are then dislodged by percussive impact. The various combinations of waveform energies can be utilized alone or in conjunction one with the other, without deviating from the invention disclosed herein. Specific waveform frequencies, amplitudes, and related parameters are dependent, in part, upon the specific well bore, pumping, casing and screening apparatus, as well as the particular type of production impediment to be removed. Likewise, the waveforms used are limited only by various practical considerations and mechanical and equipment tolerances relating to the high pressure, rapid deployment of such waveforms. In addition, the methods of this invention can be used with gravel wall, screened wells, screened wells in consolidated formations, and with steel or iron casings--all without depth limitation. Other advantages are features of the invention will become apparent from the claims hereinafter, with the scope of the claims determined by the reasonable equivalents as understood by those skilled in the art.
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A non-destructive method for stimulating, refurbishing, or otherwise increasing production from water wells, using pressure waveforms and mass displacement within the well bore volume. The non-destructive methods are useful in a variety of water production contexts and can be modified downhole to meet specific performance requirements.
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BACKGROUND OF THE INVENTION
[0001] Entity extraction is a common problem faced in the computer automation of document review. This problem often arises when an organization needs to review a large repository of files searching for predefined terms. For instance, a law firm may need to search millions of pages of documentation for a specific individual's name.
[0002] This problem may be compounded when there are no predefined terms. An organization may need to review a large document repository and determine the elements generally common to the documents.
BRIEF SUMMARY OF THE INVENTION
[0003] The present invention is directed toward the extraction of operational entities from unstructured data files.
[0004] The present invention is also directed to software used to automate the extraction and/or detection of operational entities from unstructured data files.
[0005] The present invention is also directed to the determination of common operational entities within a single document. This is referred to the “gist” of the document.
[0006] The present invention is also directed to the determination of common operational entities between a plurality of documents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a diagram of a positive extraction process.
[0008] FIG. 2 is a diagram of the negative extraction process.
[0009] FIG. 3 is a flowchart of the process of creating the Negative Entity Dictionary.
[0010] FIG. 4 a is a Venn diagram showing the relationship between the Word Dictionary and the Name Dictionary.
[0011] FIG. 4 b is a Venn diagram showing the relationship between the Word Dictionary and the Name Dictionary, where the elements belonging to NED are shown in black.
[0012] FIG. 4 c is a Venn diagram showing the relationship between the Word Dictionary, the Name Dictionary, and the Common Dictionary.
[0013] FIG. 4 d is a Venn diagram showing the relationship between the Word Dictionary, the Name Dictionary, and the Common Dictionary, where the elements belonging to NED are shown in black.
[0014] FIG. 4 e is a Venn diagram showing the relationship between the Word Dictionary and the Name Dictionary, the Common Dictionary, and the Topic Dictionary.
[0015] FIG. 4 f is a Venn diagram showing the relationship between the Word Dictionary and the Name Dictionary, the Common Dictionary, and the Topic Dictionary, where the elements belonging to NED are shown in black.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Extracting operational entities from an electronic document is the process in which an electronic document is reviewed and a set of words or phrases is determines that capture basic relevant information about the document. This process may be carried out manually by a human operator, or it may be carried out automatically by a computer program.
[0017] Speed of execution is often the most important factor. Manual extraction often produces a reliable result, however it is very slow as compared with computer programs. Many business and government entities have millions of documents with unstructured text which need to be searched. The time and expense required to employ a human operator to review each document is prohibitive.
[0018] Many organizations prefer an automated solution for entity extraction. Automated solutions are consistent, fast, and able to run 24 hours a day. These solutions are designed to review a document, extract operational entities, and save the results in a data store or create a notification when certain entities are discovered.
[0019] Entity extraction algorithms commonly use a database as support. The database is comprised of terms which wish to be identified. A typical algorithm opens a document and examines each word. The word is checked against the dictionary, and if a match is found, this word is added to a list of entities discovered in the document. The process is repeated for each word in the document.
[0020] Although this process is very effective for certain types of documents, it falls short in many instances. For example, an entity may appear in the document misspelled. Unless the precise misspelling is present in the dictionary, this process will fail to register the presence of the entity. Additionally, if the extractor seeks to identify names, every name in existence worldwide needs to be present in the dictionary.
[0021] This is further complicated by transliteration of names into English. Transliteration is the process of representing a foreign word using the alphabet of English (generally, transliteration is representing a word in one language with the alphabet of another language). This process is often done by attempting to represent the sound of the word with letter combinations approximating that sound. This often leads to a single word having many possible transliterations. For instance, the name Mohamed may commonly be written as Mohamed, Mohammed, Mohamet, Muhammed, etc.
[0022] The present invention is directed toward an entity extraction algorithm capable of identifying all operational entities, even when misspelled, and capable of identifying all names. The present invention is distinct over those described above as it is a negative extractor. The details of this invention and its advantages are described below.
[0023] A positive extractor is one in which each word is checked against a dictionary, and if the word is found in the dictionary, the word is identified as an entity. This process requires a positive match against the dictionary. Thus, the entities in the document result from the intersection of the document and the dictionary. This is represented in equation 1, where E is the set of entities, ED is the set of words in the electronic document, and D is the set of words in the dictionary.
E=ED∩D, (I)
[0024] The present invention is a negative extractor. Each word in the document is checked against a dictionary, and if the word is not found the word is identified as an entity. Thus, the entities in the document result from the document minus the intersection of the document with the dictionary. This is represented in equation 1, where E is the set of entities, ED is the set of words in the electronic document, and D is the set of words in the dictionary.
E=ED−ED∩D. (2)
[0025] The dictionary used in the negative extractor contains all words that are not considered entities. Construction of this negative entity dictionary (NED) is the key to the operation of the negative extractor. Three separate dictionaries are required for the proper construction of NED.
[0026] The constructing the dictionary begins with creating a first dictionary of all words (Word Dictionary). This dictionary should also contain plurals, contractions, and every verb conjugation. This dictionary will serve as the base core of NED.
[0027] Next, a second dictionary is created of all personal names (Name Dictionary). The names should contain male and female first names as well as all surnames. It is not necessary for the Name Dictionary to be a worldwide complete list. Instead, it is sufficient to create a list of names common to the language or languages of the Word Dictionary. This dictionary improves NED by removing all names from the Word Dictionary.
[0028] Third, a dictionary is created of common words appearing on the name dictionary (Common Dictionary). When reviewing names, especially last names, it is often the case that some last names are also highly common words. For instance, a complete list of last names in America includes last names of: The, Of, To, And, In, Is, It, and You. Although there are individuals in America with these last names, typically when these words are seen in a document they are not names. Including then as names would lead to significant false positives from the entity extractor. This dictionary improves NED by adding back common English words which may occasionally also be individuals names.
[0029] Finally, an optional dictionary or set of dictionaries is included (Topic Dictionary). These dictionary are topic specific and may be included when information is known about the documents. For instance, if the documents involve military operations, a fourth dictionary may be a dictionary of military terms. The words in the dictionary are removed from NED.
[0030] NED is constructed by combining these three dictionaries. The core of NED is the Word Dictionary. From this set, the words common to NED and the Name Dictionary are removed from NED. Next, the Common Words are added back into NED. Finally, words in the Topic Dictionary are removed from NED.
[0031] Equation 3 mathematically represents the set process for creation of NED. Here WD is the Word Dictionary, ND is the Name dictionary, CD is the Common dictionary and TD's are the Topic Dictionaries.
NED = ( WD - WD ⋂ ND ) ⋃ CD -
( ( WD - WD ⋂ ND ) ⋃ CD ) ⋂ ⋃ i TD i . ( 3 )
[0032] Additional features designed to identify names and places within text may further improve the negative entity extraction process. For instance, if the text contains a mix of capitol and lower case letters, a word that begins with a capitol letter is often a name or place. When using this feature, it is helpful to break the text on sentences and examine each sentence individually. This is helpful because words that begin a sentence are typically capitalized. Thus, a word which begins with a capitol letter and it the first word is a sentence is likely not a place or name. However, when a word begins a sentence and does not begin with a capitol letter, the word is typically a name or place.
[0033] Another feature designed to improve detection of names and places is combining consecutive entities. For instance, if the text contains a plurality of consecutive entities, this may also be treated as a single entity by combining the entities together. In the preferred embodiment, this combining process takes place by concatenating the entities together with a single space (‘ ’)between each entity. For instance, if the name ‘Albert Einstein’ is encountered, the entity extractor recognizes ‘Albert’ and ‘Einstein’ as entities. Since these entities appear consecutively, the entity extractor further recognizes ‘Albert Einstein’ as an entity.
[0034] There are several advantages to using a negative extractor. First, since the negative entity extractor eliminates words from the text, the words remaining will contain misspellings. Thus, this type of extractor is useful to discover misspelled words or words which contain additional white space (such as a space, tab, carriage return, linefeed, etc.). This occurs frequently in text discovered by an OCR (Object Character Recognition) process. In addition, text generated by a speech-to-text engine often contains misspellings and/or additional white space.
[0035] In a less preferred embodiment, the negative entity extractor may work with sound data. In this case, it is desired to search files containing sound data. This data may be processed by using a Speech-To-Text engine to create a text version of the sound file. This text file is then processed in the same manner as described above.
[0036] In another less preferred embodiment, the negative entity extractor may work directly with sound data files. In this case, rather than transforming the sound files into text files, the extractor may work directly with the sound files. Again, a series of dictionaries are created using the same process as described above. However, rather than containing words in a text representation, these dictionaries contain sound data. This sound data may be as simple as a single sound (phoneme), or may be a word, a phrase, musical note, or any other sound or combination of sounds.
[0037] In another less preferred embodiment, the negative entity extractor may work with image data. In this case, it is desired to search files containing image data such as handwritten notes. This data may be processed by using an Object-Character-Recognition engine to create a text version of the image file. This text file is then processed in the same manner as described above.
[0038] In another less preferred embodiment, the negative entity extractor may work directly with image data files. In this case, rather than transforming the image files into text files, the extractor may work directly with the image files. Again, a series of dictionaries are created using the same process as described above. However, rather than containing words in a text representation, these dictionaries contain image data. This image data may be as simple as a single pixel, or may be an object, or any other image or combination of images.
DETAILED DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 shows a typical Positive Entity Extraction process. The process begins by identifying a set of terms to find ( 100 ). These terms are used to compile a dictionary of terms. It is only necessary to compile this dictionary once. Next, a document comprising unstructured text is identified ( 105 ). This document is then parsed word-by-word ( 110 ). Each word found in the document is checked against the dictionary ( 115 ).
[0040] The process then branches by determining if the word is found in the dictionary ( 120 ). If the word is found in the dictionary, the word is added to a list of entities found in the document ( 125 ). The process then rejoins the main branch.
[0041] If the word is not found in the dictionary, the process continues on the main branch. If there are more words in the document to process, the process loops back and checks the next word ( 130 ). If there are no more words to check, the list of entities found in the document are saved along with a reference to the document ( 135 ).
[0042] FIG. 2 shows the negative entity extraction process. First NED is compiled ( 200 ). These terms are used to compile a dictionary of terms. It is only necessary to compile this dictionary once. Next, a document comprising unstructured text is identified ( 205 ). This document is then parsed word-by-word ( 210 ). Each word found in the document is checked against NED ( 215 ).
[0043] The process then branches by determining if the word is found in NED ( 220 ). If the word is NOT found in NED, the word is added to a list of entities found in the document ( 235 ). Optionally, if a sequence of consecutive entities are found ( 225 ), they may be concatenated together to form a single entity ( 230 ). The concatenation process typically separates the concatenated entities with a space (‘ ’) or dash (‘-’). The concatenated entity is added to the list of entities found ( 235 ). The process then rejoins the main branch.
[0044] If the word is found in NED, the process continues on the main branch. If there are more words in the document to process, the process loops back and checks the next word ( 240 ). If there are no more words to check, the list of entities found in the document are saved along with a reference to the document ( 245 ).
[0045] FIG. 3 shows the process of creating NED. First, the relevant dictionaries are identified. These dictionaries are combined by adding and subtracting elements. After all dictionaries have been combines, the final dictionary created is NED.
[0046] A Word Dictionary ( 300 ) is created containing all words of interest in the language. This dictionary should also contain each plural, contraction, verb conjugation, and every other form a word may appear.
[0047] A Name Dictionary ( 305 ) is created containing all first and last names common to the language of the Word Dictionary. Only the names common to the language or culture of the Word Dictionary are needed. In addition, not every transliterated spelling variant is required. Only the most common variants are needed.
[0048] A Common Dictionary ( 310 ) is created after examining the Name Dictionary. This examination may be done by hand, or it may be completed using statistical information of the relative frequencies or rankings of the names. If may be the case that an uncommon name such as Do is also a common word. A decision is made this word should be treated as a word or as a name. If it is decided to treat the word as a name, nothing need to be done. If it is decided to treat the word as a word, the word is added to the Common Dictionary.
[0049] A Topic Dictionary ( 315 ) is created with words common to a topic. For instance, if military terms are the topic, words such as general, corporal, bomb, ordnance, fighter, and carrier may be added to the topic dictionary. A plurality of Topic Dictionaries may be created covering a variety of topics.
[0050] The first step in the creation of NED is to remove elements from the Word Dictionary ( 300 ). The elements to remove are those that are common to both the Word Dictionary ( 300 ) and the Name Dictionary ( 305 ). Thus, all elements found in the Name Dictionary ( 305 ) are subtracted from the Word Dictionary ( 300 ). The resulting dictionary is called NED 1 ( 325 ) in FIG. 3 .
[0051] Next, the elements in the common dictionary are added back ( 340 ). The resulting combination of NED 1 ( 325 ) and the Common Dictionary ( 310 ) is termed NED 2 ( 345 ).
[0052] Optionally, the terms from any Topic Dictionaries ( 315 ) are removed ( 360 ). The dictionary resulting from this step is termed NED ( 365 ) in FIG. 3 . If no Topic Dictionaries ( 315 ) are used, the NED 2 ( 345 ) is used as the NED ( 365 ).
[0053] FIGS. 4 a - f shows the process of creating NED in terms of Venn diagrams.
[0054] In FIG. 4 a, the intersecting sets of the Word Dictionary ( 400 ) and the Name Dictionary ( 405 ) are indicated. In addition, the intersection of these sets ( 410 ) is indicated. NED, ( 325 ) results from the subtraction from the Word Dictionary ( 400 ) of the intersection of the Word Dictionary ( 400 ) and the Name Dictionary ( 405 ). FIG. 4 b shows the results of this process. Here, the dark area is the elements retained after the subtraction process. FIG. 4 c shows the addition of the Common Dictionary ( 415 ) to the set. Here, the region common to the Word Dictionary ( 400 ) and Name Dictionary ( 405 ), but not in common to the Common Dictionary ( 415 ) is indicated ( 420 ). The elements present in this new dictionary is indicated as the dark area in FIG. 4 d.
[0055] FIG. 4 e shows the removal of the Topic Dictionary ( 425 ). The region common to the Word Dictionary ( 400 ) and the Name Dictionary ( 405 ), but uncommon to either the Common Dictionary ( 415 ) or Topic Dictionary ( 425 ) is indicated ( 430 ). The elements present in the new dictionary created after removal of the elements in the Topic Dictionary ( 425 ) is indicated as the dark area in FIG. 4 f. This final area indicated the elements present in NED.
Other Embodiments
[0056] It should be appreciated that the particular implementations shown and described herein are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity details of the potential forms of the documents have been ignored. These documents may be presented in a common format such as a text file, MS Word, Adobe Acrobat, a MS Office product, or any other computer readable format.
[0057] It should be appreciated that the entity extractor described is not limited to working with English words but may be used in any language. English words were used in this document to illustrate the process. In addition, the entity extractor is capable of working with a plurality of languages simultaneously. This may be implemented by incorporating several languages into the dictionary, or applying a plurality of single language extractors in parallel to a single document.
[0058] It should also be appreciated that it is contemplated the entity extractor may work with documents in an encrypted form. The entity extractor may be designed to work with an unencrypted form of the document, or it may be designed to work directly with the encrypted document.
[0059] It should also be appreciated that it is contemplated that the words in the Common Dictionary may be added depending on the relative frequency of the name verses the relative frequency of the word. For instance, a method to determine if a specific name found in the Name Dictionary should also be added to the Common Dictionary may involve an algorithm with inputs comprising the relative frequency of the name and the relative frequency of the word in common language.
[0060] In addition, rather than using relative frequencies, it is also contemplated to use the rank ordered popularity. In this case, a list of names is sorted by popularity. The words may also be sorted by popularity. The algorithm to determine if a specific name should be added back to the Common Dictionary may include inputs comprising the rank ordered popularity of word as a name along with the word as a word.
[0061] Additionally, it is contemplated that an algorithm determining whether a given word should be added to the Common Dictionary may include as inputs any combination of the relative frequency of the word, the rank ordered popularity of the word, the relative frequency of the name, and/or the rank ordered popularity of the name.
[0062] It should be appreciated that the sound data files may be in a variety of formats. For instance, the sound files may be file types such as .wav, .mpeg, .mp2, .mp3, avi, .wfb, .wfd, .wfp, or any other computer readable file format comprising sound data.
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The present invention is directed toward a technique for the identification of operational entities in unstructured text. The technique consists of the preparation of a series of dictionaries, combining these dictionaries into a single Negative Element Dictionary, then searching an unstructured file for terms matching those in the Negative Element Dictionary. Each term present in the unstructured file but not present in the Negative Element Dictionary is considered an operational entity.
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BACKGROUND OF THE INVENTION
The present invention relates to the field of paint spray pumps, particularly those which have a need for both a priming mode or function and an adjustable pressure mode or function while spraying after priming.
Prior art pumps typically had a fixed pressure setting and switched from a priming mode to a spraying mode at the fixed pressure setting. Other prior art pumps had a pressure adjustment mechanism separate from the prime/spray control. The present invention provides an improvement over such arrangements by providing an integrated apparatus that provides both prime/spray mode control and adjustable pressure setting operation for an electrical pressure control in the spray mode.
BRIEF SUMMARY OF THE INVENTION
The present invention may be seen to be a combined prime valve and electrical pressure control apparatus for paint spray pumps including an inlet port and an outlet port and a return port for the paint spray pump, a prime valve, and a pressure control, with the prime valve and pressure control each contained within a single control housing and each coupled to a single shaft for selectively actuating the prime valve to one of a prime mode and a spray mode, wherein the valve in the prime mode fluidly couples the inlet port to the return port and wherein the valve in the spray mode couples the inlet port to the outlet port and wherein the pressure control is operable within a pressure setting range to control the operation and output pressure delivered by the pump using an electrical control adjustable by movement of the shaft while the valve remains in the spray mode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a paint sprayer pump assembly useful in the practice of the present invention.
FIG. 2 is an enlarged fragmentary side section view of the paint sprayer pump assembly taken along line II-II of FIG. 1 .
FIG. 3 is a front elevation view of a combined prime valve and electrical pressure control apparatus of the present invention shown in a priming mode.
FIG. 4 is a view similar to that of FIG. 3 , except shown in a spray mode with a low pressure setting.
FIG. 5 is a view similar to that of FIG. 3 in the spray mode, except shown at a high pressure setting.
FIG. 6 is a perspective view of the apparatus of the present invention shown from above and to the right.
FIG. 7 is a perspective view of the apparatus of the present invention shown from above and to the left.
FIG. 8 is a plan view of a pressure setting cam useful in the practice of the present invention.
FIG. 9 is a perspective view of an electric motor and pump assembly useful in the practice of the present invention.
FIG. 10 is a front elevation view of the motor and pump assembly of FIG. 9 .
FIG. 11 is an exploded view of parts from FIG. 10 .
FIG. 12 is a front plan view similar to that of FIG. 8 of the cam assembly of FIGS. 10 and 11 .
FIG. 13 is a rear plan view of the cam assembly of FIG. 12 .
FIG. 14 is a side elevation view of the cam assembly of FIG. 12 .
FIG. 15 is a perspective view from the front of the cam assembly of FIG. 12 .
FIG. 16 is a perspective view from the rear of the cam assembly of FIG. 12 .
FIG. 17 is a perspective view from the front of a control housing useful in the practice of the present invention.
FIG. 18 is a perspective view from the rear of the control housing of FIG. 17 .
FIG. 19 is a rear elevation view of the control housing of FIG. 17 .
FIG. 20 is a side elevation view of the control housing of FIG. 17 .
FIG. 21 is a bottom plan view of the control housing of FIG. 17 .
FIG. 22 is a front elevation view of the control housing of FIG. 17 .
FIG. 23 is a first section view taken along line XXIII-XXIII of FIG. 22 .
FIG. 24 is a second section view taken along line XXIV-XXIV of FIG. 22 .
FIG. 25 is a side view of a pressure transducer assembly useful in the practice of the present invention.
FIG. 26 is a section view taken along line XXVI-XXVI of FIG. 25 .
FIG. 27 is a perspective view of a lever useful in the practice of the present invention.
FIG. 28 is a first side elevation view of the lever of FIG. 27 .
FIG. 29 is an end elevation view of the lever of FIG. 27 .
FIG. 30 is a second side elevation view of the lever of FIG. 27 .
FIG. 31 is a section view taken along line XXXI-XXXI of FIG. 30 .
FIG. 32 is a first side elevation view of a pressure switch assembly useful in the practice of the present invention.
FIG. 33 is an end elevation view of the pressure switch assembly of FIG. 32 .
FIG. 34 is a second side elevation view of the pressure switch assembly of FIG. 32 .
FIG. 35 is a bottom plan view of the pressure switch assembly of FIG. 32 .
FIG. 36 is a view similar to that of FIG. 10 , except with parts shown in a first position during assembly, and with a portion of the lever cutaway to illustrate certain details of the present invention.
FIG. 37 is a view similar to that of FIG. 36 , except with parts shown in a second position during assembly.
FIG. 38 is a view similar to that of FIG. 37 , except with parts shown in a third position during assembly.
FIG. 39 is an enlarged view of detail XXXIX of FIG. 36 except further cut away and with a C-ring omitted and showing parts in an initial position during an installation process for attachment of the lever to the prime valve in the practice present invention.
FIG. 40 is an enlarged detail view of detail XIL of FIG. 37 except further cut away and showing parts advanced to a second position from that shown in FIG. 39 .
DETAILED DESCRIPTION
Referring now to the Figures, and most particularly to FIGS. 1 and 2 , a paint spray pump assembly 2 useful in the practice of the present invention may be seen. It is to be understood that assembly 2 is designed and intended to be used to supply paint or similar coating material under pressure to a hand-held paint spray gun (not shown) via a hose (not shown) connected to a paint pump outlet 4 . A paint hopper 6 provides paint to the pump 8 . A knob 9 is provided to operate the combined prime valve and pressure control 10 of the present invention.
Referring now also to FIG. 3 , a front elevation view of the prime valve and pressure control apparatus 10 of the present invention may be seen. The apparatus has a single control housing 12 for both the prime valve 14 and the pressure control 16 . A first cam 18 is shown in a first position 20 corresponding to a priming mode. In this position, cam 18 pushes a single prime control pin 22 that urges a lever 24 to pull a poppet (not shown) off a seat (not shown) to provide a priming mode for the paint pump 8 to which apparatus 10 is fluidly connected. In position 20 , a second cam 26 is in a first position 28 , corresponding to a low pressure setting. The single prime control pin or prime valve actuator 22 is oriented with and free to move along a prime valve actuator axis 23 . Cam 18 is movable about an axis 53 of a single shaft 54 on which cam 18 is mounted.
Referring now to FIG. 4 , first cam 18 is in a second position 30 , corresponding to a spraying mode in which the priming mode is deactivated. It may be noted that a radius 32 of cam 18 at the pin 22 in the second position 30 is less than a radius 34 of cam 18 at pin 22 in the first position 20 ( FIG. 3 ). This allows the poppet of the prime/spray valve to return to contact with its mating seat to shift from a priming mode to a spraying mode.
Second cam 26 is shown in a second position 36 in FIG. 4 in which a pressure control pin 38 urges a switch carrier 40 to move to a low pressure position 42 . It is to be understood that the pressure control pin or electrical pressure control actuator 38 is oriented with and movable along an electrical pressure control actuator axis 39 . It is also to be understood that the second position 36 is preferably only slightly elevated above the pressure level of the first position 28 of cam 26 , indicated by the slightly increased radius 44 of cam 26 at pin 38 in this position, compared to the radius 46 of cam 26 at pin 38 when cam 26 is in the first position 28 . Each of the axes 23 and 39 are oriented generally diametrically opposite one another, and perpendicular to axis 53 . As will be seen infra, the axes 23 and 39 are offset along axis 53 from each other, to align with cams 18 and 26 , respectively.
Referring now to FIG. 5 , first cam 18 moves to a third position 48 in which cam 18 has a radius 50 substantially equal to radius 32 , keeping the prime/spray valve 14 in the spray mode. In FIG. 5 , cam 26 has an increased radius 52 aligned with pin 38 as compared to the operating radius 46 of FIG. 4 for the low pressure spraying mode. The increased radius 52 sets the switch carrier 40 to a third or high pressure position 51 (for both the pressure control 16 and the second cam 26 ).
It is to be understood that the knob 9 is preferably received over a shaft 54 to operate apparatus or assembly 10 . Shaft 54 is rotatable to a selected one of the first position 20 , 28 , the second position 30 , 36 and the third position 48 , 51 , as desired, by an operator, to achieve a selected one of the priming, low pressure spraying and high pressure spraying modes.
Referring now to FIG. 8 , an outline view of the second cam 26 may be seen. In this embodiment, cam 26 may have indentations or detents 56 , 58 and 60 aligned respectively with the first position 28 , the second position 36 and the third position 51 , to assist the operator in positioning knob 9 to the desired mode of operation, and to retain the apparatus in the selected desired mode at one of the first, second and third positions 28 , 36 , and 51 , corresponding to the priming mode, low pressure spraying mode, and high pressure spraying mode.
Referring now to FIGS. 9-16 , various views of an alternative embodiment of the present invention may be seen. In this embodiment, slight alterations may be seen in the cam assembly containing cams 18 ′ and 26 .′ A pump inlet 72 receives paint from the paint hopper 6 . The pump 8 delivers paint to the outlet 4 during spraying. When the apparatus 10 is in the priming mode, a valve is opened between the pump inlet 72 and the return line 74 , with the valve actuator 76 moving to the left, as shown in FIG. 3 .
In FIG. 10 the prime valve and pressure control apparatus 10 is shown in the first position 20 (the prime mode) corresponding to that shown in FIG. 3 .
FIG. 11 shows an exploded view of the apparatus 10 , with a lever 62 on one side of the control housing 12 ′ and a pressure transducer assembly 64 and a pressure switch assembly 66 on the other side of the housing 12 .′ Each of the lever 62 and the pressure switch assembly 66 are retained to a base housing 13 (to which the control housing 12 ′ is attached) by respective pivot pins 68 , 70 , when parts are assembled. In FIG. 11 , a “C” ring 78 is shown in the exploded view and also shown rotated 90 degrees in view 80 to illustrate the topology of ring 78 . Ring 78 is used to retain a washer 82 on the valve actuator shaft 76 when received in a groove 84 sized to receive ring 78 , in a manner to be described infra.
Pressure control pin 38 may have a hat or cap 86 , which may be formed of nylon 6/6, to provide a low friction sliding contact with the pressure switch assembly 66 . Assembly 66 is held against the pressure transducer assembly 64 by a spring 88 .
Referring now to FIGS. 12-16 , various views of a cam assembly 90 useful in the practice of the present invention may be seen. Cam assembly 90 includes first cam 18 and second cam 26 mounted for rotation by shaft 54 . A plurality of apertures 92 may be provided in cam assembly 90 for engagement with a projection 94 on knob 9 (as may be seen in FIG. 2 ). Reception of projection 94 in a particular one of apertures 92 provides positive, repeatable engagement between knob 9 and cam assembly 90 . Cam assembly 90 may be formed by insert molding cams 18 and 26 to shaft 54 .
Referring now to FIGS. 17-24 , various views of control housing 12 ′ may be seen. It is to be understood that this embodiment differs from that shown in FIGS. 3-5 in that the control housing 12 includes fluid ports, while control housing 12 ′ is a separate housing for the cam assembly 90 and does not itself include fluid ports, but rather is connected to a pump housing having the fluid ports and certain operating components contained therein. More particularly, control housing 12 includes the outlet port 4 and the prime/spray valve (connected to valve actuator 76 ) and pressure transducer assembly 64 . The control housing 12 ′ (together with base housing 13 ) may be secured to or form part of a pump housing by a conventional threaded fastener secured through aperture 96 . Control housing 12 ′ straddles the outlet port 4 with a pair of legs 98 . A cam chamber 100 provides a generally cylindrical recess 102 for the cam assembly 90 . A centrally located bore 104 provides a bearing surface for a rear extension 106 of shaft 54 . A first radially extending bore 108 supports the prime control pin 22 and a second radially extending bore 110 supports the pressure control pin 38 . Bores 108 and 110 are preferably axially offset, as may be clearly seen in FIG. 24 , to align pins 22 and 38 with the first and second cams 18 , 26 , respectively, when cam assembly 90 is received in the cam chamber 100 .
Referring now most particularly to FIGS. 21 and 24 , there is an offset 111 between axes 23 and 39 . Offset 111 is aligned with axis 53 of shaft 54 to provide alignment of pin 22 with cam 18 and alignment of pin 38 with cam 26 .
Referring now most particularly to FIGS. 25 and 26 , a side and section view of the pressure transducer assembly 64 may be seen. Assembly 64 includes an outer housing 112 having external threads 114 to secure the assembly in the pump housing. One or more hexagonal bosses 116 are provided with conventional wrench flats 118 to enable installation and removal of the assembly 64 . A piston 120 is received in housing 112 and sealed thereagainst by an O-ring 122 . Piston 120 has a flange 124 against which a compression spring 126 reacts with respect to the housing 112 . A face O-ring 128 seals the outer housing 112 against the pump housing to which it is attached. It is to be understood that an inner face 130 of piston 120 is exposed to the pressure of the paint at the outlet 4 of the pump 8 when the assembly 64 is installed in the pump housing and the pump is operating. In operation, a stem 132 extends out of housing 112 by a distance proportional to the pressure on face 130 . Stem 132 will act on the pressure switch assembly 66 in a manner described infra.
Turning now to FIGS. 27-31 , various views of lever 62 may be seen. Lever 61 is pivotably attached to one of the control housing 12 (as shown in FIG. 6 ) or to the base housing 13 or the pump housing (as shown by FIG. 11 ). Lever 62 has a clevis 134 formed by a pair of ring like projections 136 , spaced apart from each other and each of which have an aperture 140 to receive the pivot or clevis pin 68 to pivotably secure the lever 62 to a similar apertured ring 138 (see FIG. 11 ) on the part to which the lever is attached. Lever 62 also has a distal projection 142 to receive the force of the prime control pin 22 . A groove 144 may be formed in projection 142 to matingly receive a correspondingly rounded end on pin 22 . A recess 146 is formed in the body 148 of the lever 62 . An arcuate bearing surface 150 having a radius 152 is formed in the body 148 adjacent the recess 146 . Surface 150 preferably has an elongated slot 154 formed therein to receive the valve actuator stem 76 . When the parts are assembled, surface 150 is in contact with washer 82 .
Referring now most particularly to FIGS. 32-35 , various views of the pressure switch assembly 66 may be seen. Assembly 66 includes a conventional switch 160 of the type manufactured under the trademark Microswitch by Honeywell. Switch 160 has an operator 162 covered by a lever 164 , and terminals 166 , 168 for electrical connection. Switch 160 may be mounted to the switch carrier 40 by a pair of posts 170 with push-on retaining fasteners 172 . Carrier 40 may have a first extension 174 with a bore 176 for pivotably mounting the assembly 66 to the base housing 13 using pivot pin 70 (shown in FIG. 11 ). Carrier 40 may also have a second extension 178 with a set screw 180 installed therein to serve as a bearing surface for pressure control pin 38 . As may be seen by reference to FIGS. 7 and 11 , the spring 88 , connected between a screw 184 in switch carrier 40 and a boss 186 on the pressure transducer assembly 64 preferably urges assembly 66 towards the pressure transducer assembly 64 mounted to base housing 13 , while the pressure control pin 38 positions the assembly 66 at a desired distance (corresponding to the desired pressure) from the pressure transducer assembly 64 .
Referring now to FIGS. 36-40 certain aspects of a process of assembly of the prime valve and pressure control apparatus of the present invention may be seen. In FIGS. 36 and 39 , parts are shown in a first position during assembly, with a portion of the lever 24 cutaway. To assemble the prime valve parts, the cam assembly 90 is rotated to an “install” position 190 shown in FIG. 36 , and the washer 82 is assembled on the valve actuator shaft 76 , as may be seen most clearly in FIG. 39 , after which the C ring 78 is placed in groove 84 on the shaft 76 , retaining the washer 82 and lever 24 to the valve actuator 76 . Next, the cam assembly 90 is rotated about 240 degrees counterclockwise to a position 192 shown in FIG. 37 , moving the lever 24 away from base housing 13 and causing the ring 78 to become tight against a wedge-shaped recess 188 in washer 82 , as may be seen most clearly in FIG. 40 .
After the assembly process associated with the prime valve is complete (as described above), the pressure control apparatus may be assembled. The pressure control pin 38 is inserted in bore 110 in the housing 12 (or 12 ′), cap 86 is placed on pin 38 , and the pressure switch assembly 66 is pivotably attached to the base housing 13 using pivot pin 70 . Spring 88 is then installed between the pressure switch assembly 66 and the base housing 13 , to urge the switch carrier 40 and switch 160 towards and against the stem 162 of the pressure transducer assembly 64 . It may be noted that once pin 38 is installed, the cam assembly 90 cannot thereafter be rotated from position 192 back to the install position 190 , because of interference between pin 38 and an end-of-travel tab 194 on the second cam 26 . Setscrew 180 maybe adjusted in switch carrier 40 by advancing or retracting setscrew 180 in a threading motion with respect to the carrier 40 to calibrate the set point of switch 160 as activated by stem 162 at a desired maximum pressure setting. The maximum pressure setting position 196 is obtained by rotating the cam assembly 90 to the maximum pressure setting position 196 of cam 26 . The pump 8 is turned on, and the pressure monitored while the setscrew 180 is screwed into or out of the carrier 40 until the desired pressure setting is reached and the pump is turned off by switch 160 at that pressure.
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A combined prime valve and electrical pressure control apparatus including a prime valve actuator, an electrical pressure control actuator, and a control housing containing the actuators, with each coupled to a single shaft having a cam assembly for selectively actuating the control apparatus to one of a prime mode and a spray mode and the electrical pressure control is operable within a range of pressure settings by movement of the shaft while the control apparatus remains in the spray mode. The actuators are oriented diametrically opposite and offset along an axis of the single shaft with respect to each other, and contact the cam assembly and respectively contact a lever for a prime valve and a pressure switch carrier. A setscrew in the carrier provides adjustment of the pressure at which the switch is actuated.
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RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 14/538,550, filed Nov. 11, 2014, which is a continuation of U.S. patent application Ser. No. 11/414,752, filed on Apr. 28, 2006, now U.S. Pat. No. 8,886,706, which is a continuation-in-part of U.S. patent application Ser. No. 11/172,700, filed on Jun. 30, 2005, and which is also a continuation-in-part of U.S. patent application Ser. No. 11/094,763, filed on Mar. 31, 2005, now U.S. Pat. No. 8,694,589, all of which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates generally to backup systems, and more specifically to an embedded archiving tool for backing up user-provided data on a server.
BACKGROUND
[0003] A wide variety of application programs may be executed on client computers. These include programs that are implemented in a client-server system using a network, such as the World Wide Web, which is also referred to as the Internet. These application programs offer users a broad array of functionality and help users perform complicated tasks and improve their overall productivity.
[0004] Backing up or storing current content that has been provided by users of application programs that are implemented on existing client-server systems, for example, as a locally stored saved-draft file, may be problematic. For example, the application programs may not have the necessary privileges to allow local storage of saved draft files on the client computers. And while saved-draft files may be stored on a server, waiting for a respective user to initiate such archiving may also be challenging. If a service error, such as a network or network interface failure, interrupts such an application program before the saved-draft file has been created, the current content provided by the respective user may be inadvertently lost.
[0005] There is a need, therefore, for an improved backup system for applications programs operating in client-server systems.
SUMMARY
[0006] A method of archiving content is described. A web page corresponding to an application program is transmitted to a client computer using a network. The web page includes instructions corresponding to an embedded archiving tool. The embedded archiving tool is to store content provided to the web page by a user. The content is stored on a server remotely located from the client computer when an archiving condition is satisfied.
[0007] The application program may include an electronic messaging program. The application program may include an email application, a text processor, a spread sheet application, a presentation authoring tool, a blog authoring tool, a webpage-based form for entering information to be stored in a server, a web-page authoring tool, and/or an advertising program registration tool. More generally, the method of archiving content, and the archiving tool, can be used in conjunction with virtually any application program that accepts user-edited information.
[0008] The archiving condition may be satisfied when at least a pre-defined time has elapsed since a previous instance of storing content on the server, when at least a pre-determined number of modifications to the content have occurred, and/or when a length of the content increases by at least a pre-defined amount.
[0009] The content may include the content of an electronic message and/or one or more attachments to an electronic message.
[0010] The storing may be delayed if the user has modified the content within at least a preceding time interval and/or if the user is currently attaching one or more attachments to the content.
[0011] The archiving condition may include closing of the application program and/or closing of a browser.
[0012] The stored content may be compressed using a compression algorithm and/or encrypted using an encryption algorithm.
[0013] The instructions in the web page may include performing the storing in response to the user activating a save icon. Storing of the content may include generating a store request, constructing content to be stored on the server (where the content to be stored corresponds to the content in the application program), and/or transmitting the content to be stored to the server. In some embodiments, a copy of the content on the client computer is generated when the store request is generated.
[0014] In some embodiments, the save icon in the web page is highlighted whenever the content includes any modifications not stored on the server, and the highlighting of the save icon is removed whenever the content is stored on the server.
[0015] In some embodiments, the copy of the content is compared to the content to be stored prior to the transmission of the content to be stored. The highlighting of the save icon may be removed only if the copy of the content and the content to be stored are equivalent.
[0016] In some embodiments, a content-saved message is displayed when the user re-starts the application program and/or the browser. In some embodiments, at least a subset of the stored content is reconstructed and presented to the user when a restart condition is detected.
[0017] In another embodiment, a web page corresponding to an application program is received at a client computer using a network. The web page includes executable instructions corresponding to an embedded archiving tool. The embedded archiving tool is to store content provided to the web page by a user. The content is stored on a server remotely located from the client computer when an archiving condition is satisfied.
[0018] One or more embodiments may be implemented as a computer readable storage medium that includes an embedded computer program mechanism. In another embodiment, a computer may include memory, a processor and a program for archiving content. The program for archiving content may correspond to one or more embodiments. The program may be stored in the memory and executed by the processor. In other embodiment, information corresponding to one or more embodiments may be communicated between a server and a client computer using a network.
[0019] The challenges associated with existing archiving approaches may be reduced and/or eliminated by the aforementioned embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a better understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 is a flow diagram illustrating an embodiment of interaction between a client and a server.
[0022] FIG. 2 is a flow diagram illustrating an embodiment of interaction between a client and a server.
[0023] FIG. 3 is a flow diagram illustrating an embodiment of a method of restoring content.
[0024] FIG. 4 is a flow diagram illustrating an embodiment of a method of storing content.
[0025] FIG. 5A is a block diagram illustrating a message composition form or page of an email application program.
[0026] FIG. 5B is a block diagram illustrating a message composition form or page of an email application program.
[0027] FIG. 6 is a block diagram illustrating an embodiment of a server.
[0028] FIG. 7 is a block diagram illustrating an embodiment of a client computer.
[0029] FIG. 8 is a block diagram illustrating an embodiment of a server data structure.
[0030] FIG. 9 is a block diagram illustrating an embodiment of a cookie file.
[0031] Like reference numerals refer to corresponding parts throughout the drawings.
DETAILED DESCRIPTION OF EMBODIMENTS
[0032] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.
[0033] A system and method of archiving user content is disclosed. In some embodiments, an archiving tool is embedded in web-page instructions transmitted from a server to a client computer using a network, such as an intranet and/or the Internet, which is also referred to as the World Wide Web (WWW). When the web-page instructions are rendered by a browser (such as Netscape Navigator™, Internet Explorer™, Firefox™ or Safari™) or a standalone program that displays a structured document such as a web page on the client computer, the embedded archiving tool may be used to archive content provided by the user to an application program via the web page. Thus, the embedded archiving tool may execute in the browser environment, which in this context functions as a virtual machine.
[0034] The application program may be implemented in a client-server system. The application program may include an electronic messaging program. In some embodiments, the application program may include an email application, a text processor, a spread sheet application, a presentation authoring tool, a blog authoring tool, a webpage-based form for entering information to be stored in a server, a web-page authoring tool, and/or an advertising program registration tool. More generally, the method of archiving content, and the archiving tool, can be used in conjunction with virtually any application program that accepts user-edited information. The embedded archiving tool may be written in JavaScript™ (a trademark of Sun Microsystems, Inc.), ECMAScript (the specification for which is published by the European Computer Manufacturers Association International), VBScript™ (a trademark of Microsoft, Inc.) and/or any other client-side scripting language. In other words, the embedded archiving tool includes programs or procedures containing JavaScript, ECMAScript instructions, VBScript instructions, or instructions in another programming language suitable for rendering by the browser or another client application.
[0035] The embedded archiving tool may store content provided to the web page and/or the application program by a user. The content may include the content of an electronic message and/or one or more attachments to an electronic message. The content may be stored on a client computer and/or on a server computer located remotely from the client computer. The storing may include creating or updating one or more archive files. The storing of at least a portion of the content may occur when an archiving condition is satisfied. The archiving condition may include when a user provides or changes the content (for example, after a character is typed on a user interface device such as a keyboard) and/or after a pre-determined time interval (for example, a few seconds, a few tens of seconds or a few minutes) since the user started providing or changing the content. In some embodiments, the archiving condition may be satisfied when a user activates a save icon in the application program, when at least a pre-defined time has elapsed since a previous instance of storing the content (for example, if more than 2 minutes have elapsed since the most recent instance of storing), when at least a pre-defined time has elapsed since a previous instance of modifying the content (for example, if more than 2 minutes have elapsed since the most recent instance of modifying the content), when at least a pre-determined number of modifications to the content have occurred (for example, 100 modifications), when a length of the content increases by at least a pre-defined amount, and/or when the application program and/or browser is closed. For example, the archiving condition is satisfied after 2 minutes since a most recent modification of the content or 100 modifications (e.g., the addition or deletion of 100 characters), which ever comes first.
[0036] In some embodiments, periodic updates to the archive files may be made whenever the user has entered any new content or has modified any of the previously entered content. In some embodiments, the storing may be delayed if the user has modified the content within at least a preceding time interval. For example, if the user has modified the content in the last 2 seconds the storing may be delayed by 2 seconds to prevent archiving while the user is modifying the content. In some embodiments, the storing may be delayed if the user is currently attaching one or more attachments to the content. In some embodiments, a timer that is tracking an elapsed time since a most recent instance of storing may be suspended while the user is attaching an attachment.
[0037] In some embodiments, the one or more archive files may be initially stored on the client computer and at least a subset of the content stored in the one or more archive files may be subsequently stored on the server. In these embodiments, a corresponding subset of the content that was previously stored on the client computer (in the one or more archive files) may be erased, deleted or overwritten when at least the subset of the content is stored on the server. In some embodiments, the one or more archive files may be stored on the client computer and on the server. From a general viewpoint, the archiving tool uses archive files to store user-provided content that may be needed by the user in the future. When user-provided content or information is no longer needed by the user, the content or information in one or more archive files, on the client computer and/or the server, may be deleted.
[0038] When the user has completed providing the content to the application program (for example, a final version of the content is provided) and the user instructs the application program that he or she is finished (for example, the user hits a send button or icon in an email application program), the one or more archive files stored on the client computer and/or the server may be deleted, erased or overwritten. In some embodiments, the one or more archive files may expire, and may be deleted, erased or overwritten, after a certain amount of time (e.g., 24 hours, 168 hours, or a month) has elapsed since the one or more archive files were created or last updated.
[0039] The browser may keep track of which archive files exist and/or which archive files have been created. If the application program and/or the browser is shut down, either intentionally or unintentionally, or communication with the application program and/or the browser is temporarily disrupted (for example, due to a network failure), the one or more archive files may be used to reconstruct and present at least some of the content to the user. For example, if the user restarts the application program (for example, the user attempts to download a web page associated with the application program) and a presence of the one or more archive files is detected, a restart condition is detected and at least some of the content is reconstructed and presented to the user. In some embodiments, the content may be reconstructed on the client computer. In other embodiments, the content may be reconstructed on the server. In other embodiments, the content may be partially reconstructed on the client computer and partially reconstructed on the server. For example, during a restart one or more locally stored archive files may be sent to the server and the server may return a web page or instructions for a web page including the content that was stored in the one or more archive files and/or content that was stored on the server.
[0040] In some embodiments, the deletion of the archive files may not take place until the server positively notifies the client code that the save action has completed successfully. This may happen, for example, when the client issues its next request to the server.
[0041] In some embodiments, the one or more archive files may include cookie files or cookies. The cookie files may include the content provided by the user and/or the user data. The cookie files may be stored locally, i.e., on the client computer. In some embodiments, some or all of the content stored on the server may be stored on the server as cookie files and/or using another file format.
[0042] Typically, cookie files are computer-generated files that are issued to the client computer by a “cookie server,” i.e., a host server, associated with a universal resource locator (URL) either before or while the URL is electronically contacted by the client computer. While cookie files are typically created by a host server, cookie files can also be created and/or updated by a client. For example, the embedded archiving tool may create and store a cookie file directly in a cookie cache of the client computer. The cookie files are transparent and may be automatically enabled by an operating system (such as WINDOWS) without special security privileges. In addition to user cookies, archive files may be implemented using “userData” stores or objects, and other types of data storage files, objects and the like. The term “cookie file” is sometimes used in this document to mean any type of archive file that is used to store user data or backup data associated with a web page or network-implemented application.
[0043] As noted above, the one or more cookie files, and more generally, the archive files, may be generated locally by the embedded archiving tool in a web page. Alternatively, the one or more cookie files and/or archive files may be generated on the server, i.e., the content may be transmitted to the server and the corresponding one or more cookie files and/or archive files may be generated. The resulting cookie files and/or archive files may be stored on the server and/or transmitted back to the client computer for local storage. In some embodiments, cookie files and/or archive files may be stored in memory in the client computer (such as cookie cache) or in data structures other than traditional files, such as records in a database.
[0044] Typically, the browser restricts cookie files based on a name space (such as an Internet protocol address or domain name). As a consequence, in embodiments where the archive files include cookies, the embedded archiving tool may assign a domain name or URL to a respective cookie. In some embodiments, the domain name or URL in the respective cookie may be fictitious, i.e., the domain name or URL may only have meaning to the embedded archiving tool. The one or more cookie files may also include time stamps corresponding to when the content was archived and/or position or location information. The latter may be useful for application programs that have multiple fields in a window or a browser window. (A “window” or “browser window” comprises a virtual graphical display area for viewing a web page, HTML file, extensible markup language or XML file, or the like. A “window” typically corresponds to a “tab” or “window” or the like in various browser programs.)
[0045] Depending on a size of the content, one or more archive files may be used by the embedded archiving tool. (For example, typically, cookie files are restricted to a size of 4 kilobytes.) In some embodiments, additional content is appended to one or more of the archive files, as needed, during archiving. During reconstruction, the embedded archiving tool and/or code executed on the client computer and/or the server may stitch the one or more archive files together and/or arrange corresponding content in an appropriate temporal order or relative spatial position (for example, in a “window”).
[0046] To help reduce a size of one or more archive files, in some embodiments at least a portion of the content may be compressed using a compression algorithm. In some embodiments, at least a portion of the content may be encrypted using an encryption algorithm. This may allow the privacy of the content to be protected, especially if the client computer is used by two or more users. Encryption may include symmetric encryption and/or public key encryption. In embodiments that include encryption, the server may provide a decryption key, as needed, by the embedded archiving tool.
[0047] In some embodiments, the archiving tool is added to a web page by inserting a single instruction (e.g., a JavaScript instruction) into the web page. The inserted instruction loads the archiving tool from the server into the client. In one version of this embodiment, the archiving tool is a general tool that is not specific to any particular web page. When loaded into the client, the tool examines the web page to identify the fields in which a user may enter content, and then tracks and stores content entered into those fields. In other versions, the archiving tool may be customized to a particular web page or family of web pages, so as to eliminate or simplify the task of identifying the fields of the web page in which a user may enter content.
[0048] While the preceding discussion described embodiments where the archiving tool is embedded in a web page, in other embodiments the archiving tool may be resident or installed on the client computer.
[0049] Attention is now directed towards embodiments of an embedded archiving tool for backing up user-provided data. FIG. 1 is a flow diagram illustrating an embodiment of an information archiving method 100 for storing content, entered by a user into a web page or other online form at a client 112 , on a server 110 . A web page including an embedded archiving tool is transmitted ( 114 ) to the client 112 . The web page including the embedded archiving tool is received ( 116 ) by the client 112 . Whether or not an archiving condition is satisfied is determined ( 118 ). For example, a store icon may be activated by the user. In some embodiments, a store request may be generated when the archiving condition is satisfied. Content to be stored is constructed ( 120 ). A local copy of the content to be stored is optionally generated ( 122 ). The local copy may be optionally stored in one or more cookie files on the client 112 . For example, the local copy of the content is optionally stored in one, two or more cookie files.
[0050] During normal operation, such as when the user performs an action that indicates completion of a web page form, or upon the occurrence of another event, information corresponding to the content is transmitted ( 124 ) to the server 110 . In some embodiments, the information locally stored in one or more cookie files is transmitted to the server 110 when the amount of data stored in the one or more cookie files exceeds a predefined limit or threshold. For instance, this may be done to avoid exceeding a data storage limit associated with the cookie files, and to free up space to store more backup data.
[0051] The information corresponding to the content is received and stored ( 126 ) at the server 110 . In some embodiments, the server 110 sends an acknowledgement of receipt of the information to the client 112 . In some embodiments, the acknowledgement of receipt is not sent until the information has been successfully and durably stored by the server 110 . Upon receiving the acknowledgement, the client 112 may delete one or more cookie files corresponding to the information that has been stored by the server. In some embodiments, the “acknowledgment” may be a cookie file deletion command sent by the server 110 to the client 112 .
[0052] In some embodiments, an instance of operations 124 and 126 may not performed if the user or client 112 closes the web page prior to the content being transmitted to the server 110 , or a failure or other event at the client 112 prevents the browser from sending the content to the server 110 . When any such intervening event occurs, a recovery process is performed, as will be described below with respect to FIG. 2 .
[0053] The information archiving method 100 may include fewer operations or additional operations. In addition, two or more operations may be combined and/or the order of the operations may be changed.
[0054] FIG. 2 is a flow diagram illustrating an embodiment of a method 200 of recovering archived information. A restart of an application program and/or a browser after a crash or accidental closure is detected ( 210 ). A web page is requested ( 212 ) by a user of the client computer 112 . User verification information is optionally transmitted by the client 112 to the server 110 along with the web page request ( 212 ). The verification information may help prevent one user from accessing content, such as that stored in one or more archive files, corresponding to another user. The verification information may include a user name and/or a user password. The server 110 receives a request for the web page and stored content, as well as optional user verification information ( 214 ). The server 110 transmits the web page, including the embedded archiving tool, and the stored content ( 216 ). The client 112 receives the web page and the stored content ( 218 ).
[0055] In some embodiments the restart condition is detected by the embedded archiving tool, for example, by detecting an existence of one or more cookie files on the client 112 that contain stored or archived content. In other embodiments, the restart condition is detected by the server, either by the existence of one or more archive files on the server 110 and/or by sending a request to the client 112 for cookie files corresponding to a particular URL. In the latter case, if the client 112 responds by sending cookie files with archived content, a restart condition is detected. It should be noted that in embodiments in which the restart condition is detected by the server 110 , a cookie request (if any) would typically be sent to the client 112 prior to sending the web page to the client 112 .
[0056] Once a restart condition is detected, at least a subset of the content stored in the one or more cookie files and/or one or more archive files is reconstructed ( 220 ) and presented ( 222 ) to the user in the context of the web page. In embodiments in which the restart condition is detected by the embedded archiving tool, the reconstructed content is inserted into one or more fields of the web page by the archiving tool. In embodiments in which the restart condition is detected by the server 110 , the reconstructed content is inserted by the server 110 into one or more fields of the web page prior to sending the web page to the client 110 . The archived information recovery method 200 may include fewer operations or additional operations. In addition, two or more operations may be combined and/or the order of the operations may be changed.
[0057] FIG. 3 is a flow diagram illustrating an embodiment of a method 300 of restoring archived information or content. A web page including an embedded archiving tool is received ( 310 - 1 ). Content provided by a user is stored ( 312 ). The stored content may include information that was previously transmitted (on one or more occasions) from the client 112 ( FIGS. 1 and 2 ) to the server 110 ( FIGS. 1 and 2 ). A web page including an embedded archiving tool is received ( 310 - 2 ). For example, the user may request that the web page be down loaded again after a network failure. A restart condition is detected ( 314 ). A restart condition is detected by detecting an existence of one or more cookie files and/or one or more archive files that contain stored content. At least a subset of the stored content is reconstructed and presented ( 316 ). The subset of the stored content may be presented in the web page. In other embodiments, the archived information recovery method 300 may include fewer operations or additional operations. In addition, two or more operations may be combined and/or the order of the operations may be changed.
[0058] FIG. 4 is a flow diagram illustrating an embodiment of a method 500 of storing content. The method may be performed by a client computer and/or a server computer. In some embodiments, portions of the method may be performed at a server while other portions are performed at a client computer. Content provided by a user is received one or more times ( 410 ). For example, the content may be received by a web page having one or more fields for accepting user entered content, and the content may also be received by an archiving tool embedded in the web page or otherwise executing on the client computer. The received content is stored ( 412 ), for instance in one, two or more cookie files. The times at which the received content is stored may vary from one embodiment to another. For instance, in some embodiments, the received content may be optionally stored when at least a pre-determined number of modifications to the content occur ( 414 ); the received content may be optionally stored after a pre-defined time has elapsed since a previous instance of storing the content ( 416 ); and/or the received content may be optionally stored when a length of the content increases by at least a pre-defined amount ( 418 ). In some embodiments, the process of periodically storing received content may enabled whenever the user has entered new content into the web page or has modified previously entered content in the web page. Optionally, the stored content may be compressed ( 420 ) and/or encrypted ( 422 ). The method of storing content 500 may include fewer operations or additional operations. In addition, two or more operations may be combined and/or the order of the operations may be changed.
[0059] Attention is now directed towards user interfaces that may be utilized in some embodiments of an embedded archiving tool for backing up user-provided data. FIG. 5A is a block diagram illustrating a message composition form or page of an email application program 500 . The form may be implemented as a web page rendered by a browser or other program at a client computer. Message composition form 500 illustrates a user-entry window for composing an email message, include an addressee field 510 , a “cc field” 512 for identifying one or more individuals or email addresses to be copied, a subject field 514 and a body field 516 . The user-entry window includes multiple control icons, including a send icon 518 , a save draft icon 520 , a cancel icon 522 , a restore icon 524 and/or an attachments icon 526 . If there are modifications to content, such as the content 528 , that are not stored on the server and/or the client computer, the save draft icon 518 may be highlighted. The highlighting may be removed whenever the content is stored on the client computer and/or the server, for example, if the user activates the save draft icon 520 .
[0060] Whenever content from the user is automatically saved, a message, such as “Draft autosaved at 10.15.32 AM” may be displayed. In some embodiments, the save draft icon 520 may be temporarily disabled following an instance of storing the content 528 . In these embodiments, the save draft icon 520 may be temporarily grayed out. If additional changes are made to the content 528 , the save draft icon 520 may be enabled again and its original color may be restored. In some embodiments, a comparison is made between a local stored copy of the content and the content 528 when a reply from the server that confirms that the content 528 has been stored. If the two are equivalent then the save draft icon 520 may be disabled and/or grayed out. In this way, changes to the content 528 that occur after the save draft icon 520 has been activated but before a confirmation reply from the server is received may be identified. If such as change is found, the save draft icon 520 may not be disabled and/or grayed out.
[0061] If the user activates the send icon 518 or the cancel icon 522 , the one or more archive files, such as one or more cookie files, may be deleted, erased or overwritten on the server and/or the client computer. If the user activates the save draft icon 520 , one or more archive files corresponding to content in one or more fields, such as the content 528 in the body field 516 , may be created. Alternatively, the one or more archive files may be created (e.g., by the archiving tool describe above) as content is provided or changed, or at pre-determined time intervals while content is being entered or changed by the user. If the user actives the restore icon 524 , the content stored in the one or more archive files may be reconstructed and presented. The content stored in the one or more archive files may be reconstructed (e.g., by a reconstruction module) and presented if the email application program 500 is restarted before the user activates the send icon 518 or the cancel icon 522 . In some embodiments, the restore icon 524 may be highlighted in the event that the restart condition is detected, such as by the existence of the one or more archive files.
[0062] FIG. 5B is a block diagram illustrating a message composition form or page of an email application program 550 . Content 562 in the body field 516 includes a content-saved message that is displayed when a user restarts the browser and/or the application program following a crash or accidental closure of the browser and/or the application program.
[0063] Attention is now given to hardware and systems that may utilize and/or implement the embodiments of the embedded archiving tool, such as methods 100 , 200 , 300 or 400 , discussed above. FIG. 6 is a block diagram illustrating an embodiment of a server 600 .
[0064] The server 600 may include at least one data processor or central processing unit (CPU) 610 , one or more optional user interfaces 614 , a communications or network interface 622 for communicating with other computers, servers and/or clients, memory 624 , and one or more signal lines or communication busses 612 for coupling these components to one another. The user interface 614 may include a display 618 , a keyboard 616 and/or a pointer 620 , such as a mouse, trackball or touch sensitive pad.
[0065] Memory 624 may include high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory 624 may optionally include one or more storage devices remotely located from the CPU(s) 610 . Memory 624 may store an operating system 626 , such as LINUX, UNIX or WINDOWS, that includes procedures (or a set of instructions) for handling basic system services and for performing hardware dependent tasks. Memory 624 may also store communication procedures (or a set of instructions) in a network communication module 628 . The communication procedures are used for communicating with clients, such as the client 112 ( FIG. 1 ), and with other servers and computers.
[0066] Memory 624 may also store a web server module (or a set of instructions) 630 , a web-page processor module (or a set of instructions) 632 , a web page 634 , one or more application programs (or sets of instructions) 644 , a user verification module (or a set of instructions) 646 , an optional reconstruction module (or a set of instructions) 648 , and information data storage 650 . The web page 634 may include content information 636 and an archiving tool (or a set of instructions) 638 . The archiving tool 638 may optionally include encryption/decryption module (or a set of instructions) 640 and may optionally include a compression module (or a set of instructions) 642 . The information data storage 650 may include archive data files 652 for one or more users. The reconstruction module 648 may be used to restore content, using information stored in one or more archive files, when a restart condition is detected.
[0067] Although FIG. 6 shows the server 600 as a number of discrete items, FIG. 6 is intended more as a functional description of the various features which may be present in the server 600 rather than as a structural schematic of the embodiments described herein. In practice, and as recognized by those of ordinary skill in the art, the functions of the server 600 may be distributed over a number of servers or computers, with various groups of the servers performing particular subsets of those functions. Items shown separately in FIG. 6 could be combined and some items could be separated. For example, some items shown separately in FIG. 6 could be implemented on single servers and single items could be implemented by one or more servers. The actual number of servers and how features are allocated among them will vary from one implementation to another, and may depend in part on the amount of information stored by the server 600 and/or the amount data traffic that the server 600 must handle during peak usage periods as well as during average usage periods.
[0068] FIG. 7 is a block diagram illustrating an embodiment of a client computer or device 700 . The client computer or device 700 includes at least one data processor or central processing unit (CPU) 710 , one or more optional user interfaces 714 , a communications or network interface 722 for communicating with other computers, servers and/or clients, memory 724 and one or more signal lines and/or communication busses 712 for coupling these components to one another. The user interface 714 may have one or more keyboards 716 , a pointer device 720 such as mouse, trackball or touch sensitive pad, and/or one or more displays 718 .
[0069] Memory 724 may include high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory 724 may optionally include one or more storage devices remotely located from the CPU(s) 710 . Memory 724 may store an operating system 726 , such as LINUX, UNIX or WINDOWS, that includes procedures (or a set of instructions) for handling basic system services and for performing hardware dependent tasks. Memory 724 may also store communication procedures (or a set of instructions) in a network communication module 728 . The communication procedures are used for communicating with the server 600 ( FIG. 6 ) or any specified website or URL accessible to the client computer or device 700 .
[0070] Memory 724 may also include a browser or browser tool module 730 (or a set of instructions). The browser 730 may be used to render various web pages, including a web page having an embedded web-page archiving tool. As discussed elsewhere in this document, the web-page archiving tool may be embedded in one or more web pages received from a remote server and rendered by the browser or browser tool module 730 . In some clients, the browser 730 may render the web page 634 . The web page 634 may include the content information 636 and the archiving tool (or a set of instructions) 638 . The archiving tool 638 may optionally include an encryption/decryption module (or a set of instructions) 640 and may optionally include a compression module (or a set of instructions) 642 .
[0071] Memory 724 may also include an optional user verification module (or a set of instructions) 646 , an optional change log 732 , one or more applications programs (or a set of instructions) 734 , an optional reconstruction module (or a set of instructions) 736 , and cookie information data storage 738 . The cookie information data storage 738 may include one or more cookies 740 . The change log 732 may be used to track changes to the one or more stored archive files, such as cookies 740 - 1 and 740 - 2 , and/or to roll-back a recent change to the content, i.e., to restore a previously stored version of the content. For instance, the change log 732 may include multiple entries, each having a time stamp, a cookie file name or identifier, and optionally information indicating content changes associated with the change log entry. The reconstruction module 736 may be used to restore content, using information stored in one or more archive files, when a restart condition is detected.
[0072] In embodiments where the client computer or device 700 is coupled to the server 600 ( FIG. 6 ), one or more of the modules and/or applications in memory 724 may be stored in the server 600 ( FIG. 6 ) at a different location than the user. In particular, in some embodiments the web-page 634 , including the content information 636 and the archiving tool 638 , and/or the user verification module 646 may be contained in either the server 600 ( FIG. 6 ) and/or the client computer or device 700 . Similarly, the reconstruction module 736 may be located at the server 600 instead of the client computer or device 700 , in which case reconstruction of the user entered content is performed at the server 600 based on user provided content (if any) saved at the server and user provided content in cookie files retrieved from the client computer or device 700 and/or archive files in the server 600 ( FIG. 6 ).
[0073] Each of the above identified modules and applications corresponds to a set of instructions for performing one or more functions described above. These modules (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules. The various modules and sub-modules may be rearranged and/or combined. Memory 724 may include additional modules and/or sub-modules, or fewer modules and/or sub-modules. Memory 724 , therefore, may include a subset or a superset of the above identified modules and/or sub-modules.
[0074] Attention is now given to data structures that may be utilized in conjunction with the embedded archiving tool and the related hardware discussed above. FIG. 8 is a block diagram illustrating an embodiment of a server data structure 800 . The data structure 800 may include a plurality of archive files 810 that include user data. A respective archive file, such as archive file 810 - 2 , may include a URL pattern 812 , a user ID 814 , and one or more pairs of data. A respective pair of data may include position information 816 - 1 and content 818 - 1 . In some embodiments, the data structure 800 may include fewer or additional elements, two or more elements may be combined, and/or a position of one or more elements may be changed.
[0075] FIG. 9 is a block diagram illustrating an embodiment of a cookie file 900 , which may be stored on a client computer and/or a server. The cookie file 900 may include multiple entries, including a URL pattern 910 , a user identification 912 , and/or one or more entries including position information (for example, for a respective field in a web page or window) 914 and content 916 . The cookie file 900 may also include one or more time stamps corresponding to the content 916 and/or one or more name (or attribute)-value pairs. In some embodiments, the cookie file 900 may include fewer or additional elements, two or more elements may be combined, and/or a position of one or more elements may be changed.
[0076] The foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Rather, it should be appreciated that many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
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A host system sends a web page to a client system via a communications network, and receives inputs from the client system, via the communications network, that include user text inputs to the web page. The inputs are received without receiving from the client system, via the communications network, a user-initiated command that would require saving user inputs to the web page. The host system makes incremental changes to a backup copy of user inputs to the web page, stored at the host system, in accordance with the received inputs. In accordance with detection by the host system of a restart condition for the web page corresponding to prior closure of the web page at the client system, the host system sends the backup copy to the client system for presentation to a user of the client system.
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FIELD OF THE INVENTION
[0001] This invention relates to a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a solid acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the glycolic acid stream is readily removed from the carboxylic acid and the carboxylic acid is recycled.
BACKGROUND OF THE INVENTION
[0002] Glycolic acid (also known as 2-hydroxyacetic acid or α-hydroxyacetic acid) can be used for many purposes including as a raw material to make ethylene glycol. Glycolic acid is prepared by the acid catalyzed reaction of carbon monoxide and formaldehyde in the presence of water, alcohols, and/or carboxylic acids. These processes often require high temperatures and pressures to proceed at practical rates. For example, glycolic acid typically is prepared by reacting formaldehyde with carbon monoxide and water in the presence of an acidic catalyst such as sulfuric acid under high temperature and pressure such as, for example, above 480 bar absolute (abbreviated herein as “bara”), and between 200 and 225° C. Alternatively, lower pressures may be employed in the presence of hydrogen fluoride as a catalyst and solvent. These processes, however, require expensive materials of construction and/or recovery and recycling schemes for hydrogen fluoride. Furthermore, readily available and less expensive formaldehyde starting material typically contains large concentrations of water that inhibit the rate of the carbonylation reaction and make purification of the glycolic acid product difficult. Separation of glycolic acid and the carboxylic acid is not feasible using distillation methods because the glycolic acid reacts with the carboxylic acid under typical process temperatures. Acetic acid is similar in its hydrophobicity to glycolic acid, making extraction methods unattractive for separating glycolic acid and acetic acid. Thus, there is a need for an economical process for making glycolic acid from an aqueous formaldehyde starting material that can be accomplished at moderate temperatures and pressures and allows for the ready separation of the glycolic acid from the crude hydrocarboxylation reactor product.
SUMMARY OF THE INVENTION
[0003] The present invention provides in one embodiment a process for the preparation of glycolic acid, comprising
(A) feeding carbon monoxide, aqueous formaldehyde, and a carboxylic acid comprising 3-6 carbon atoms to a hydrocarboxylation reaction zone comprising a solid acid catalyst to produce an effluent comprising esters of glycolic and carboxylic acids; (B) hydrolyzing the effluent to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid; (C) recovering the carboxylic acid from the hydrolyzed mixture by extracting the hydrolyzed mixture with a hydrophobic solvent selected from at least one of the group consisting of esters having from 4 to 20 carbon atoms, ethers having from 4 to 20 carbon atoms, ketones having from 4 to 20 carbon atoms, and hydrocarbons having from 6 to 20 carbon atoms to form an aqueous raffinate phase comprising a major amount of the glycolic acid contained in the hydrolyzed mixture and an organic extract phase comprising a major amount of the carboxylic acid contained in the hydrolyzed mixture; and (D) separating the aqueous raffinate phase and the organic extract phase.
[0008] The present invention provides in another embodiment a process for the preparation of glycolic acid, comprising
(A) feeding carbon monoxide, aqueous formaldehyde, and a carboxylic acid selected from at least one of the group consisting of propionic acid, n-butyric acid, i-butyric acid, 2-methyl butyric acid, n-valeric acid, and i-valeric acid to a hydrocarboxylation reactor zone comprising a solid acid catalyst to produce an effluent comprising esters of glycolic and carboxylic acids; (B) hydrolyzing the effluent to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid; (C) recovering the carboxylic acid from the hydrolyzed mixture by extracting the hydrolyzed mixture with a hydrophobic solvent selected from at least one of the group consisting of n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, s-butyl acetate, methyl propionate, ethyl propionate, i-propyl propionate, methyl tertiary-butyl ether, methyl i-butyl ketone, methyl i-propyl ketone, methyl propyl ketone, and toluene to form an aqueous raffinate phase comprising a major amount of the glycolic acid contained in the hydrolyzed mixture and an organic extract phase comprising a major amount of the carboxylic acid contained in the hydrolyzed mixture; and (D) separating the aqueous raffinate phase and the organic extract phase.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic of an embodiment of the present invention for hydrocarboxylation of an aqueous formaldehyde feed using propionic acid.
[0014] FIG. 2 is a schematic of an embodiment of the present invention for hydrocarboxylation of an aqueous formaldehyde feed using valeric acid.
DETAILED DESCRIPTION
[0015] The present invention provides in a first embodiment a process for the preparation of glycolic acid, comprising
(A) feeding carbon monoxide, aqueous formaldehyde, and a carboxylic acid comprising 3-6 carbon atoms to a hydrocarboxylation reaction zone comprising a solid acid catalyst to produce an effluent comprising esters of glycolic and carboxylic acids; (B) hydrolyzing the effluent to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid; (C) recovering the carboxylic acid from the hydrolyzed mixture by extracting the hydrolyzed mixture with a hydrophobic solvent selected from at least one of the group consisting of esters having from 4 to 20 carbon atoms, ethers having from 4 to 20 carbon atoms, ketones having from 4 to 20 carbon atoms, and hydrocarbons having from 6 to 20 carbon atoms to form an aqueous raffinate phase comprising a major amount of the glycolic acid contained in the hydrolyzed mixture and an organic extract phase comprising a major amount of the carboxylic acid contained in the hydrolyzed mixture; and (D) separating the aqueous raffinate phase and the organic extract phase.
[0020] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Further, the ranges stated in this disclosure and the claims are intended to include the entire range specifically and not just the endpoint(s). For example, a range stated to be 0 to 10 is intended to disclose all whole numbers between 0 and 10 such as, for example 1, 2, 3, 4, etc., all fractional numbers between 0 and 10, for example 1.5, 2.3, 4.57, 6.1113, etc., and the endpoints 0 and 10. Also, a range associated with chemical substituent groups such as, for example, “C 1 to C 5 hydrocarbons”, is intended to specifically include and disclose C 1 and C 5 hydrocarbons as well as C 2 , C 3 , and C 4 hydrocarbons.
[0021] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0022] It is to be understood that the mention of one or more process steps does not preclude the presence of additional process steps before or after the combined recited steps or intervening process steps between those steps expressly identified. Moreover, the lettering of process steps or ingredients is a convenient means for identifying discrete activities or ingredients and the recited lettering can be arranged in any sequence, unless otherwise indicated.
[0023] As used herein the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.
[0024] The term “glycolic acid”, as used herein, refers to the chemical compound, glycolic acid, also known as 2-hydroxyacetic acid. The term “glycolic acid oligomers”, as used herein, refers to the reaction products of glycolic acid with itself, particularly the linear or cyclic esters formed by a reaction between the carboxyl group of one molecule and the alcohol group of another molecule. The “glycolic acid oligomers” include, but are not limited to, (2-hydroxyacetoxy)acetic acid (G2), 2-(2′-hydroxyacetoxy)acetoxyacetic acid (G3), and 2-(2′-(2″-hydroxyacetoxy)acetoxy)acetoxyacetic acid (G4). The term “esters of glycolic and carboxylic acids”, as used herein, refers to the esters produced by the reaction of a carboxylic acid with the hydroxyl end of glycolic acid and/or its oligomers.
[0025] The term “hydrocarboxylation reaction zone”, as used herein, refers to the part of the process wherein the carbon monoxide, aqueous formaldehyde, and carboxylic acid are fed, a solid acid catalyst is fed to or contained therein, and esters of glycolic and carboxylic acids are produced. The term “effluent”, as used herein, refers to the liquid stream exiting the hydrocarboxylation reaction zone comprising the “esters of glycolic and carboxylic acids”.
[0026] The term “hydrolyzing”, as used herein, refers to reacting with water. The term “hydrolyzed mixture”, as used herein, refers to the effluent from a hydrocarboxylation reaction zone after “hydrolyzing” it; the “hydrolyzed mixture” comprises glycolic acid and carboxylic acid that are the product of “hydrolyzing” the “esters of glycolic and carboxylic acids”.
[0027] The term “extracting”, as used herein, refers to separating a component from a feed into an immiscible liquid based upon relative differences in solubility. As used herein, the term “feed” is intended to have its commonly understood meaning in the liquid-liquid extraction art, which is the solution that contains the materials to be extracted or separated. The term “extraction solvent”, as used herein, is intended to be synonymous with the term “extractant” or “solvent” and is intended to mean the immiscible liquid that is used in the extraction process to extract materials or solutes from the feed. The term “extract” is the immiscible liquid left from the extraction solvent after it has been contacted with the feed. The term “raffinate” is intended to mean the liquid phase left from the feed after it has been contacted with the extraction solvent. The term “wash solvent” is understood to mean a liquid used to wash or enhance the purity of the raffinate or extract phase.
[0028] The term “hydrophobic solvent”, as used herein, refers to a solvent that will phase separate when mixed with water. The “hydrophobic solvent” is synonymous with the extractant solvent for the present invention. In the present invention, examples of hydrophobic solvents are “esters”, “ethers”, “ketones”, and “hydrocarbons” which are terms well known to those skilled in the art. In the present invention, the extraction produces an organic extract phase and an aqueous raffinate phase. The term a “major amount”, as used herein, for example “a major amount of the glycolic acid contained in the hydrolyzed mixture” refers to at least 50 weight percent of the glycolic acid contained in the hydrolyzed mixture. In a further example, when a raffinate phase comprises a major amount of the glycolic acid in the hydrolyzed mixture, the weight of the glycolic acid in the raffinate phase divided by the weight of the glycolic acid in the hydrolyzed mixture is at least 50 weight percent. The term a “minor amount”, as used herein, for example “a minor amount of glycolic acid in the hydrolyzed mixture” refers to less than 50 weight percent of the glycolic acid in the hydrolyzed mixture. The term “hydrophilic solvent”, as used herein, refers to a solvent that is miscible with water.
[0029] The term “molar ratio”, as used herein, refers to the moles of one component divided by the moles of another component. For example, if the molar ratio of carboxylic acid to formaldehyde is 2:1, then for every mole of formaldehyde, there are two moles of carboxylic acid. Note that the water in any aqueous formaldehyde feed is not considered in the molar ratio of carboxylic acid to formaldehyde.
[0030] The terms “reactions of ethylene glycol and glycolic acid”, and “reacting ethylene glycol and glycolic acid”, and “reacting ethylene glycol with an aqueous raffinate phase” which comprises glycolic acid, as used herein, refer to the many reactions that occur when ethylene glycol and glycolic acid are present at typical reaction conditions. The reactions include reactions between ethylene glycol and glycolic acid and reactions of glycolic acid with itself. Additionally, the reactions include reactions between ethylene glycol, glycolic acid, and glycolic acid oligomers or other reaction products such as 2-hydroxyethyl 2-hydroxyacetate. The term “glycolate ester oligomers”, as used herein, refers to the many reaction products of glycolate esters formed by “reacting ethylene glycol and glycolic acid”. Examples include, but are not limited to, 2-hydroxyethyl 2-hydroxyacetate, 1,2-ethanediyl bis(2-hydroxyacetate), 2′-[2″-(2′″-hydroxyacetoxy)acetoxy]ethyl 2-hydroxyacetate, 2′-(2″-[2″-(2″″-hydroxyacetoxy)acetoxy]acetoxy)ethyl 2-hydroxyacetate, 2″-hydroxyethyl (2′-hydroxyacetoxy)acetate, 2″-hydroxyethyl 2′-(2″-hydroxyacetoxy)acetoxyacetate, and 2″″-hydroxyethyl 2′-[2″-(2%-hydroxyacetoxy)acetoxy]acetoxyacetate.
[0031] The aqueous formaldehyde used in the hydrocarboxylation reaction typically comprises 35 to 85 weight percent formaldehyde. Other examples of formaldehyde levels in the aqueous formaldehyde feed are 40 to 70 weight percent and 40 to 60 weight percent. These ranges are typical concentrations that can be achieved with conventional formaldehyde processes without further distillation. Conventional formaldehyde processes are described in “Formaldehyde”, Kirk-Othmer Encyclopedia, Vol. 11, 4 th Edition, 1994. For example, commercially available formaldehyde typically contains approximately 55 weight percent formaldehyde in water. Other forms of formaldehyde may be present in the aqueous formaldehyde feedstock including trioxane or paraformaldehyde and linear oligomers and polymers of formaldehyde, i.e., poly(oxymethylene) glycols and derivatives thereof, formed from the polymerization or oligomerization of formaldehyde in water or other solvents. The term “formaldehyde”, as used herein, is intended to include all the various forms of formaldehyde described above.
[0032] In the process of the present invention, the carboxylic acid serves as a solvent and promoter for the hydrocarboxylation reaction. The carboxylic acid will react in the hydrocarboxylation reaction zone to form a corresponding acyloxyacetic acid. For example, acetic acid can react to form acetoxyacetic acid, propionic acid can react to form 2-propionoxyacetic acid, and the like. The acyloxyacetic acids are hydrolyzed to produce glycolic acid and the carboxylic acid. The carboxylic acid is chosen to give the best improvement to the hydrocarboxylation reaction conversions and reaction selectivities while simultaneously providing easy separation between the glycolic acid and carboxylic acid. In one example, the carboxylic acid comprises 3 to 6 carbon atoms. In another example, the carboxylic acid comprises 3 to 5 carbon atoms. The carboxylic acid can be one or more of propionic acid, n-butyric acid, i-butyric acid, 2-methyl butyric acid, n-valeric acid, and i-valeric acid. In one example, the carboxylic acid comprises propionic acid. In another example, the carboxylic acid comprises n-valeric acid.
[0033] In the process of the present invention the molar ratio of carboxylic acid to formaldehyde (carboxylic acid:formaldehyde) fed to the hydrocarboxylation zone can vary over a considerable range. Examples include feeding at a carboxylic acid:formaldehyde ratio of from 0.2:1 to 10:1, or 0.2:1 to 6:1, or 0.2:1 to 4:1, or 0.2:1 to 2.5:1, or 0.2:1 to 2:1, or 0.5:1 to 10:1, or 0.5:1 to 6:1, or 0.5:1 to 4:1, or 0.5:1 to 2.5:1, or 0.5:1 to 2:1, or 0.7:1 to 10:1, or 0.7:1 to 0.7:6, or 0.7:1 to 0.7:4, or 0.7:1 to 0.7:2.5, or 0.7:1 to 2:1.
[0034] The hydrocarboxylation process can be carried out by feeding carbon monoxide to a reaction mixture comprising aqueous formaldehyde in the presence of a solid acid catalyst. The carbon monoxide typically is supplied to the reaction mixture in sufficient excess to insure an adequate supply thereof for absorption by the formaldehyde and to retard side reactions such as, for example, the decomposition of the formaldehyde to carbon monoxide and hydrogen or other products. The amount of carbon monoxide useful for the carbonylation reaction ranges from a molar ratio of 1:1 to 1,000:1 or 1:1 to 100:1 or 1:1 to 20:1 or 1:1 to 20:1 or 2:1 to 20:1 or 2:1 to 10:1 of carbon monoxide to formaldehyde or formaldehyde equivalents.
[0035] The composition of the carbon monoxide stream required for hydrocarboxylation may comprise carbon monoxide, hydrogen, and carbon dioxide. For example, the carbon monoxide may be supplied in substantially pure form or as a mixture with other gases such as, for example, hydrogen, carbon dioxide, methane, nitrogen, noble gases (e.g., helium and argon), and the like. For example, the carbon monoxide need not be of high purity and may contain from 1% by volume to 99% by volume carbon monoxide. The remainder of the gas mixture may include such gases as, for example, nitrogen, hydrogen, water, carbon dioxide, noble gases, and paraffinic hydrocarbons having from one to four carbon atoms. In order to reduce compression costs, it is desirable for the carbon monoxide stream to comprise at least 95 mole % carbon monoxide, more preferably at least 99 mole %.
[0036] The carbon monoxide may be obtained from typical sources that are well known in the art. For example, the carbon monoxide may be provided by any of a number of methods known in the art including steam or carbon dioxide reforming of carbonaceous materials such as natural gas or petroleum derivatives; partial oxidation or gasification of carbonaceous materials, such as petroleum residuum, bituminous, sub bituminous, and anthracitic coals and cokes; lignite; oil shale; oil sands; peat; biomass; petroleum refining residues of cokes; and the like. For example, the carbon monoxide may be provided to the reaction mixture as a component of synthesis gas or “syngas”, comprising carbon dioxide, carbon monoxide, and hydrogen.
[0037] The hydrocarboxylation process can be conducted under continuous, semi-continuous, and batch modes of operation and may utilize a variety of reactor types. Examples of suitable reactor types include, but are not limited to, stirred tank, continuous stirred tank, trickle bed, tower, slurry, and tubular reactors. A typical temperature range for the hydrocarboxylation reaction is from 110 to 220° C. Other examples of the temperature range are from 110 to 210° C., 110 to 200° C., 110 to 190° C., 120 to 220° C., 120 to 210° C., 120 to 200° C., 140 to 220° C., 140 to 210° C., or 150 to 210° C. Examples of pressure ranges for the hydrocarboxylation reaction are 35 to 250 bar gauge, 35 to 200 bar gauge, and 60 to 200 bar gauge. In one example of the process, carbon monoxide, aqueous formaldehyde comprising 35 weight percent to 85 weight percent formaldehyde, based on the total weight of the aqueous formaldehyde, and carboxylic acid are fed at a molar ratio of carbon monoxide to formaldehyde ranging from 1:1 to 10:1, and the hydrocarboxylation reaction zone is operated at a pressure of from 35 bar gauge to 200 bar gauge and a temperature of from 120° C. to 220° C.
[0038] The hydrocarboxylation reactants may be introduced separately or in any sequence or combination to the hydrocarboxylation reaction zone. In addition, one or more reactants may be introduced at different locations in the reactor. For example, in a continuously operated process containing a catalyst bed in a reactor, the addition of water or formaldehyde may be staged throughout the reactor. In some cases, it may be desirable to recirculate a portion of the reaction media to the reactor to act as a liquid reaction media for the next synthesis. In order to reduce by-product formation, it is desirable to set the residence time in the hydrocarboxylation reaction zone to give an outlet formaldehyde concentration of 5 weight percent or less. In addition to glycolic acid, the hydrocarboxylation process typically produces glycolic acid oligomers, water, and unreacted formaldehyde. When carboxylic acids are present, the hydrocarboxylation process typically also produces esters of glycolic and carboxylic acids.
[0039] The advantages of using solid acid catalysts in the hydrocarboxylation reaction include being able to readily separate the reaction product and catalyst by mechanical means. The liquid phase reaction of carbon monoxide and formaldehyde is promoted by using certain solid phase, insoluble particulate catalyst materials. The term “insoluble” as used herein means that the catalyst is substantially insoluble in any combination of reactants or reaction products under reaction conditions present in the practice of hydrocarboxylation. The description of the catalyst as “particulate” refers to its size being such that it is separable from a liquid medium by simple means. Typical catalyst particle diameters are 2.0 to 0.001 millimeters.
[0040] In general, substances capable of forming Lewis or Brønsted type acids are useful catalysts. Examples of solid acids include strong acid cation exchange resins, solidified acids, clay minerals, zeolites, inorganic oxides and composite oxides. They are characterized in having their acid function available on a solid surface without releasing acidity into the liquid reaction medium. The acidity required of materials useful as catalysts in the practice of this invention may be measured as hydrogen ion exchange capacity. Although the catalysts or process of the present invention are not based on any theory of ion-exchange, it is useful to define the acidity criteria of acceptable solid catalysts as those which have hydrogen ion-exchange capacity of at least 0.1 milliequivalents per gram.
[0041] Strong acid type cation-exchange resins in hydrogen form are useful catalysts in the practice of hydrocarboxylation. Illustrative resins are those strong acid types having sulfonic acid functionality. The strong acid moiety may be pendant to a variety of polymeric backbones such as styrene-divinylbenzene or tetrafluoroethylene. The choice of polymeric backbone will depend on a variety of factors such as cost and temperature resistance. For instance, AMBERLYST resins produced by Rohm & Haas, Inc. are sulfonated styrene-divinylbenzene with increasing degrees of crosslinking corresponding to higher divinylbenzene content: AMBERLYST 15, 36 and 70 have maximum recommended operating temperatures of 120, 150 and 190° C., respectively. SMOPEX resins, offered by Johnson Matthey are sulfonic acid resins with a polyethylene backbone. SMOPEX 101 with 4%, 8% and 12% crosslinking have maximum operating temperatures of 160-190° C. NAFION resins offered by DuPont Inc. are sulfonated resins with fluorinated polymer backbones, providing very high acidity and chemical resistance. NAFION 50 has a maximum recommended operating temperature of 160° C.
[0042] Solid acids may also be composed of strongly acidic materials deposited on a robust support such as SAC-13 offered by BASF which contains 13% NAFION supported on silica. Likewise, Johnson Matthey offers 20% tungsten/silica which is a dicesium phosphotungstic acid (a heteropolyacid: Cs 2 HPW 12 O 40 ) supported on silica.
[0043] Examples of the clay minerals and zeolites include montmorillonite, kaolinite, bentonite, halloysite, smectite, illite, vermiculite, chlorite, sepiolite, attapulgite, palygorskite and mordenite. In particular, among these clay minerals and zeolites, preferred are those treated with an acid such as hydrogen fluoride, or those obtained by replacing a replaceable metal ion of these clay minerals and zeolites with a hydrogen ion such as H-type zeolite. Süd-Chemie offers K10 catalyst which is an example of an activated clay and has been demonstrated in this work.
[0044] In one example, the solid acid catalyst is selected from at least one of the group consisting of sulfonic acid resins, silica-aluminate, silica-alumino-phosphates, heteropolyacids, supported heteropolyacids, sulfuric acid treated metal oxides, and phosphoric acid treated metal oxides. Examples in addition to the specific commercially available catalysts above include the following. Examples of sulfonic acid resins include, but are not limited to, sulfonic acid resins of at least one of the group selected from polystyrene, polyethylene, fluorinated polymers, brominated polystyrene, chlorinated polystyrene, and fluorinated polystyrene. Examples of silica-aluminates include, but are not limited to, Zeolites such as pentasils, faujasites, chabazites, mordenites, offretites, stilbites, clinoptolites, natrolites, and the like. Examples of silica-alumino-phosphates include, but are not limited to, SAPO-5 and SAPO-34. The heteropolyacid comprises metal addenda atoms, such as tungsten, molybdenum, or vanadium, linked by oxygen atoms form a hetero-atom-centered cluster bonded via oxygen atoms. The hetero-atom is selected generally from the p-block of the periodic table, such as silicon, phosphorus, or arsenic. Examples of heteropolyacid structure are Keggin, H n XM 12 O 40 , and Dawson, H n X 2 M 18 O 62 , type clusters, such as, but not limited to H 4 X n+ M 12 O 40 , wherein X═Si, Ge and M=Mo, W; H 3 X n+ M 12 O 40 , wherein X═P, As and M=Mo, W; and H 6 X 2 M 18 O 62 , wherein X═P, As and M=Mo, W. Examples of supported heteropolyacids include, but are not limited to, H 3 PMo 12 O 40 on silica, H 3 PW 12 O 40 on silica, and H 4 SiW 12 O 40 on silica. Examples of sulfuric acid treated metal oxides include, but are not limited to, SiO 2 treated with sulfuric acid, TiO 2 treated with sulfuric acid, ZrO 2 treated with sulfuric acid, and TiO 2 /MoO 2 mixed metal oxide treated with sulfuric acid. Examples of phosphoric acid treated metal oxides include, but are not limited to, niobium oxide treated with phosphoric acid and tungsten oxide treated with phosphoric acid.
[0045] In general, the rate of reaction increases with increasing catalyst concentration. Because solid catalysts are easily separated from the reaction mixture, they can be used at higher levels to achieve shorter reaction times, lower temperatures, or lower pressures. Although the catalyst may be present in amounts as low as to provide a minimum of 0.01 mole of hydrogen ion per mole of formaldehyde, greater proportions of catalyst, approaching or exceeding one mole of hydrogen ion per mole of formaldehyde reactant, can be used to achieve higher reaction rates. In one embodiment of the process of the invention, for example, the process can be operated as a continuous process in which the maximum allowable catalyst concentration is limited only by the weight of catalyst which may be packed into the volume of the hydrocarboxylation reaction zone while preserving effective contact of reactants and practical flow rates.
[0046] In the process of the present invention, an effluent comprising esters of glycolic and carboxylic acids is produced in the hydrocarboxylation reaction zone. The esters of glycolic and carboxylic acids are produced by the reaction of a carboxylic acid with the hydroxyl end of glycolic acid and/or its oligomers. In one example, the esters of glycolic and carboxylic acid are selected from the esters of glycolic and propionic acid, the esters of glycolic and n-butyric acid, the esters of glycolic and i-butyric acid, the esters of glycolic and 2-methyl butyric acid, the esters of glycolic and n-valeric acid, the esters of glycolic and i-valeric acid, or mixtures thereof. In another example, the esters of glycolic and carboxylic acids comprise 2-propionoxyacetic acid and/or (2′-(propionyloxy)acetoxyacetic acid. In another example, the esters of glycolic and carboxylic acids comprise 2-valeryloxyacetic acid, (2′-valeryloxy)acetoxyacetic acid, and/or [2′-(2″-valeryloxy)acetoxy]acetoxyacetic acid.
[0047] The effluent from the hydrocarboxylation reaction zone may be hydrolyzed by means known to one skilled in the art. Typically, water will be added to the effluent in an excess of the amount needed to react with the esters of glycolic and carboxylic acids to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid. For example, when propionic acid is the carboxylic acid, the effluent comprises esters of glycolic of carboxylic acids which include, but are not limited to, 2-propionoxyacetic acid and (2′-(propionyloxy)acetoxyacetic acid. The glycolic acid oligomers react with water to form glycolic acid and the 2-propionoxyacetic acid and (2′-(propionyloxy)acetoxyacetic acid react with water to form propionic acid and glycolic acid. In one example the hydrolyzed mixture comprises glycolic acid and at least one carboxylic acid selected from propionic acid, n-butyric acid, i-butyric acid, 2-methyl butyric acid, n-valeric acid, and i-valeric acid. In another example, the hydrolyzed mixture comprises glycolic acid and propionic acid. In another example, the hydrolyzed mixture comprises glycolic acid and valeric acid.
[0048] The composition of the hydrolyzed mixture can vary. While increase in the amount of water may improve hydrolysis rates, the additional water must be separated from the glycolic acid. In one example, the molar ratio of water to glycolic acid in the resulting hydrolyzed mixture (water:glycolic acid) is from 1:1 to 15:1. Other examples of water:glycolic acid are from 1:1 to 8:1, or 1:1 to 6:1, or 1.5:1 to 15:1, or 1.5:1 to 8:1, or 1.5:1 to 6:1 or 2:1 to 15:1, or 2:1 to 8:1, or 2:1 to 6:1.
[0049] In the process of the present invention, the carboxylic acid is recovered by extracting the hydrolyzed mixture with a hydrophobic solvent with the glycolic acid partitioning to the raffinate. The hydrophobic solvent can be selected from esters having from 4 to 20 carbon atoms, ethers having from 4 to 20 carbon atoms, and hydrocarbons having from 6 to 20 carbon atoms. In one aspect of the invention, the hydrophobic solvent comprises ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, s-butyl acetate, methyl benzoate, i-butyl isobutyrate, 2-ethylhexyl acetate, cyclohexyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, i-butyl propionate, n-butyl propionate, s-butyl propionate, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ethers, methyl tertiary-butyl ether, methyl tertiary-amyl ether, methyl ethyl ketone, methyl i-butyl ketone, methyl i-propyl ketone, methyl propyl ketone, dibutyl ketone, diisobutyl ketone, isophorone, 3,3,5-trimethylcyclohexanone, cyclohexanone, 2-heptanone, methyl-iso-amyl ketone, diethyl ketone, 5-ethyl 2-nonanone, diamyl ketone, diisoamyl ketone, heptane, hexane, toluene, or mixtures thereof. In another aspect of the invention, the hydrophobic solvent comprises n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, s-butyl acetate, methyl propionate, ethyl propionate, i-propyl propionate, methyl tertiary-butyl ether, methyl i-butyl ketone, methyl i-propyl ketone, methyl propyl ketone, toluene, or mixtures thereof. In yet another aspect of the invention, the hydrophobic solvent comprises n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, i-propyl propionate, methyl tertiary-butyl ether, methyl i-butyl ketone, or mixtures thereof.
[0050] The process of the present invention forms an aqueous raffinate phase comprising a major amount of glycolic acid and a minor amount of carboxylic acid contained in the hydrolyzed mixture. In an aspect of the invention, greater than 80 weight percent of the glycolic acid in the hydrolyzed mixture is recovered in the raffinate phase. In another aspect, greater than 90 weight percent, greater than 95 weight percent, greater than 98 weight percent, greater than 99 weight percent, or greater than 99.5 weight percent of the glycolic acid in the hydrolyzed mixture is recovered in the aqueous raffinate phase.
[0051] The process of the present invention forms an organic extract phase comprising a major amount of the carboxylic acid and a minor amount of the glycolic acid. In an aspect of the invention greater than 90 weight percent of the carboxylic acid in the hydrolyzed mixture is recovered in the organic extract phase. In another aspect, greater than 95 weight percent, greater than 98 weight percent, or greater than 99 weight percent, or greater than 99.5 weight percent, or greater than 99.9 weight percent of the carboxylic acid in the hydrolyzed mixture is recovered in the organic extract phase.
[0052] Extracting the hydrolyzed mixture can be carried out by any means known in the art to intimately contact two immiscible liquid phases and to separate the resulting phases after the extraction procedure. For example, the extraction can be carried out using columns, centrifuges, mixer-settlers, and miscellaneous devices. Some representative examples of extractors include unagitated columns (e.g., spray, baffle tray and packed, perforated plate), agitated columns (e.g., pulsed, rotary agitated, and reciprocating plate), mixer-settlers (e.g., pump-settler, static mixer-settler, and agitated mixer-settler), centrifugal extractors (e.g., those produced by Robatel, Luwesta, deLaval, Dorr Oliver, Bird, CINC, and Podbielniak), and other miscellaneous extractors (e.g., emulsion phase contactor, electrically enhanced extractors, and membrane extractors). A description of these devices can be found in the “Handbook of Solvent Extraction”, Krieger Publishing Company, Malabar, Fla., 1991, pp. 275-501. The various types of extractors may be used alone or in any combination.
[0053] The extraction may be conducted in one or more stages. The number of extraction stages can be selected in consideration of capital costs, achieving high extraction efficiency, ease of operability, and the stability of the hydrolyzed mixture and extraction solvents to the extraction conditions. The extraction also can be conducted in a batch or continuous mode of operation. In a continuous mode, the extraction may be carried out in a co-current, a counter-current manner, or as a fractional extraction in which multiple solvents and/or solvent feed points are used to help facilitate the separation. The extraction process also can be conducted in a plurality of separation zones that can be in series or in parallel.
[0054] The extraction typically can be carried out at a temperature of 10 to 120° C. For example, the extraction can be conducted at a temperature of 30 to 80° C. The desired temperature range may be constrained further by the boiling point of the extractant components or water. Generally, it is undesirable to operate the extraction under conditions where the extractant boils. In one aspect, the extractor can be operated to establish a temperature gradient across the extractor in order to improve the mass transfer kinetics or decantation rates. In another aspect, the extractor may be operated under sufficient pressure to prevent boiling.
[0055] In an aspect of the invention, the hydrolyzed mixture is extracted in a continuous counter-current extractor. The hydrophobic solvent is fed to the extractor at a location lower than the feed location of the hydrolyzed mixture. The hydrophobic solvent moves up the counter-current extractor to form an organic extract phase exiting the top of the extractor and comprising a major amount of the carboxylic acid and a minor amount of the glycolic acid contained in the hydrolyzed mixture. The hydrolyzed mixture moves down the counter-current extractor to form an aqueous raffinate phase exiting the bottom of the extractor and comprising a major amount of the glycolic acid and a minor amount of the carboxylic acid contained in the hydrolyzed mixture. In an aspect of the invention the feed ratio of the hydrophobic solvent to the hydrolyzed mixture on a weight basis ranges from 0.1:1 to 20:1, or 0.1:1 to 10:1, or 0.1:1 to 5:1, or 0.1:1 to 4:1, or 0.5:1 to 20:1, or 0.5:1 to 10:1, or 0.5:1 to 5:1, or 0.5:1 to 4:1, or 1:1 to 10:1, or 1:1 to 5:1, or 1:1 to 4:1.
[0056] The hydrolyzed mixture and hydrophobic solvent can be contacted by fractional extraction methods such as, for example, by fractional counter-current extraction. As used herein, the term “fractional counter-current extraction” is intended to include, but is not limited to, a method for separating a feed stream, e.g., hydrolyzed mixture, containing two or more substances by charging the feed stream to a counter-current extraction process between the points where two immiscible solvents are charged to the extraction process. The two immiscible solvents should be immiscible over the entire temperature range of the extraction process. This method is sometimes referred to as “double solvent extraction.” Fractional counter-current extraction can involve the use of a cascade of stages, extracting solvents and solution to be extracted entering at opposite ends of the cascade with the feed phase and hydrophobic extractant phase flowing counter-currently. Some example fractional counter-current extraction configurations may be found in Treybal, Liquid Extraction, 2nd Edition, McGraw-Hill Book Company, New York. 1963, pp. 275-276.
[0057] In an aspect of the invention, the hydrolyzed mixture is extracted in a continuous fractional counter-current extractor. The hydrophobic solvent is fed to the extractor at a location lower than the feed location of the hydrolyzed mixture. A hydrophilic solvent is fed to the extractor at a location higher than the hydrolyzed mixture. In an aspect of the invention the feed ratio of the hydrophobic solvent to the hydrolyzed mixture on a weight basis ranges from 0.5:1 to 20:1, or 1:1 to 10:1, or 1:1 to 5:1 and the feed ratio of the hydrophilic solvent to the hydrolyzed mixture on a weight basis ranges from 0.05:1 to 2:1, or 0.1:1 to 1.5:1, or 0.1:1 to 0.8:1. In one example, the hydrophilic solvent comprises water. In another example, the hydrophilic solvent comprises water and ethylene glycol. In another example, the hydrophilic solvent comprises 50 weight percent to 100 weight percent water and 0 weight percent to 50 weight percent ethylene glycol, each on a total hydrophilic solvent weight basis.
[0058] In the process of the present invention, the extracting of the hydrolyzed mixture results in an aqueous raffinate phase comprising a major amount of the glycolic acid and a minor amount of the carboxylic acid contained in the hydrolyzed mixture and an organic extract phase comprising a major amount of the carboxylic acid and a minor amount of the glycolic acid contained in the hydrolyzed mixture. The raffinate phase and the extract phase may be separated by any phase separation technology known in the art. The phase separation techniques can be accomplished in the extractor or in a separate liquid-liquid separation device. Suitable liquid-liquid separation devices include, but are not limited to, coalescers, cyclones and centrifuges. Typical equipment that can be used for liquid-liquid phase separation devices are described in the Handbook of Separation process Technology , ISBN 0-471-89558-X, John Wiley & Sons, Inc., 1987.
[0059] One aspect of our process includes (E) separating the organic extract phase into the hydrophobic solvent and the carboxylic acid, recycling the hydrophobic solvent to step (C), and recycling the carboxylic acid to step (A). The hydrophobic solvent and carboxylic acid can be separated by any means known to one skilled in the art. Examples include by distillation and extraction. In one example, the hydrophobic solvent has a lower boiling point than the carboxylic acid and the two components are separated via distillation. The hydrophobic solvent is recovered as the distillate product and recycled for extracting in step (C) and the carboxylic acid is the bottoms product and recycled to the hydrocarboxylation reaction zone in step (A). In another example, the hydrophobic solvent has a higher boiling point than the carboxylic acid and the two components are separated via distillation. The hydrophobic solvent is recovered as the bottoms product and recycled for extracting in step (C) and the carboxylic acid is the distillate product and recycled to the hydrocarboxylation reaction zone in step (A).
[0060] One aspect of our process further includes (F) reacting a first ethylene glycol with the aqueous raffinate phase while simultaneously removing water to produce an esterification effluent comprising glycolate ester oligomers and glycolic acid oligomers and an overhead stream comprising water; and (G) reacting hydrogen with the esterification effluent to produce a second ethylene glycol, separating the second ethylene glycol into a product ethylene glycol and the first ethylene glycol, and recycling the first ethylene glycol to step (F). The reaction between the first ethylene glycol and the glycolic acid of the aqueous raffinate phase and simultaneous removal of water can be conducted under standard esterification conditions known to persons skilled in the art. Part of the water in the aqueous raffinate phase can be removed prior to esterification. For example, the esterification can be achieved by adding hot ethylene glycol to the aqueous raffinate phase and removing water formed during esterification until sufficient water is removed and an esterification effluent comprising glycolate ester oligomers and glycolic acid oligomers is formed. Typically excess ethylene glycol is used to ensure complete esterification. Examples of mole ratios of ethylene glycol to glycolic acid vary from 0.25:1 to 10:1 of 0.25:1 to 6:1 or 0.25 to 3:1 or 0.5:1 to 10:1 or 0.5:1 to 6:1 or 0.5:1 to 3:1 or 1:1 to 10:1 or 1:1 to 6:1 or 1:1 to 3:1 or 1.5:1 to 10:1 or 1.5:1 to 6:1 or 1.5:1 to 3:1 or 2:1 to 10:10 or 2:1 to 6:1. Representative conditions for esterification include at a temperature of from 150 to 250° C., preferably from 170 to 220° C., and a pressure of from 1 bara to 8 bara, preferably from 1 bara to 5 bara.
[0061] The esterification effluent can be hydrogenated to produce ethylene glycol by contacting the glycolate ester oligomers and glycolic acid oligomers with hydrogen in the presence of a suitable hydrogenation catalyst. The hydrogenation reaction can be conducted in the liquid or the gas phase using known processes. Typically, glycolate ester oligomers and glycolic acid oligomers are contacted with hydrogen under pressure in the presence of a catalyst effective for hydrogenation at temperatures from 150 to 300° C. Additional examples of temperatures ranges are from 200 to 250° C. Examples of typical pressure ranges are from 35 bara to 350 bara and 70 bara to 140 bara. Considerable latitude in the temperature and pressure of hydrogenation is possible depending upon the use and choice of hydrogenation catalyst and whether the process is conducted in the liquid or gas phase.
[0062] The hydrogenation catalyst may comprise any metal or combination of metals effective for the hydrogenation of esters to alcohols. Typical hydrogenation catalysts include, but are not limited to, at least one metal selected from Groups 8, 9, 10 of the Periodic Table of the Elements (1984 Revision by IUPAC), and copper. In addition, the hydrogenation catalyst may comprise at least one additional metal promoter selected from chromium, magnesium, barium, sodium, nickel, silver, lithium, potassium, cesium, zinc, cobalt, and gold. The term “metal”, as used herein in the context of hydrogenation catalysts, is understood to include metals in their elemental form and compounds thereof such as, for example, metal oxides, salts, and complexes with organic ligands. For example, the hydrogenation catalyst can comprise a Raney nickel or a metal oxide. Typical metal oxide catalysts include, for example, copper chromite, copper oxide, or copper oxide in combination with the oxide of magnesium, barium, sodium, nickel, silver, lithium, potassium, cesium, zinc, cobalt and the like or mixtures thereof. In another example, the hydrogenation catalyst can comprise cobalt metal in combination with zinc and copper oxides.
[0063] The esterification effluent may be purified prior to hydrogenation or may proceed directly to the hydrogenation reaction. The hydrogenation reaction produces a second ethylene glycol. The second ethylene glycol may or may not be further purified before separation into a product ethylene glycol and a first ethylene glycol which is recycled to the esterification step (F).
[0064] The present invention provides in a second embodiment a process for the preparation of glycolic acid, comprising
(A) feeding carbon monoxide, aqueous formaldehyde, and a carboxylic acid selected from at least one of the group consisting of propionic acid, n-butyric acid, i-butyric acid, 2-methyl butyric acid, n-valeric acid, and i-valeric acid to a hydrocarboxylation reactor zone comprising a solid acid catalyst to produce an effluent comprising esters of glycolic and carboxylic acids; (B) hydrolyzing the effluent to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid; (C) recovering the carboxylic acid from the hydrolyzed mixture by extracting the hydrolyzed mixture with a hydrophobic solvent selected from at least one of the group consisting of n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, s-butyl acetate, methyl propionate, ethyl propionate, i-propyl propionate, methyl tertiary-butyl ether, methyl i-butyl ketone, methyl i-propyl ketone, methyl propyl ketone, and toluene to form an aqueous raffinate phase comprising a major amount of the glycolic acid contained in the hydrolyzed mixture and an organic extract phase comprising a major amount of the carboxylic acid contained in the hydrolyzed mixture; and (D) separating the aqueous raffinate phase and the organic extract phase.
[0069] The examples of the first embodiment regarding aqueous formaldehyde, carboxylic acid, molar ratio of carboxylic acid to formaldehyde, carbon monoxide, hydrocarboxylation reaction zone process conditions, solid acid catalysts, esters of glycolic and carboxylic acids, hydrolyzing and hydrolyzed mixture composition, extraction, hydrophobic solvent and hydrophilic solvent, as well as feed ratios of each solvent to the hydrolyzed mixture on a weight basis, separation of the organic extract and aqueous raffinate, separation and recycle of the carboxylic acid and hydrophobic solvent, esterification of the glycolic acid and hydrogenation of the glycolate ester oligomers and glycolic acid oligomers to produce ethylene glycol apply to the second embodiment.
[0070] For example, the process of the invention includes an aspect wherein the feeding of the carboxylic acid and aqueous formaldehyde in step (A) occurs at a molar ratio of carboxylic acid:formaldehyde of 0.5:1 to 4:1 or 0.5:1 to 2.5:1. In another example, the hydrolyzed mixture comprises the molar ratio water:glycolic acid of from 1:1 to 8:1 or 1:1 to 6:1. In another example the hydrophobic solvent is selected from at least one of the group consisting of n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, i-propyl propionate, methyl tertiary-butyl ether, and methyl i-butyl ketone. In another example, the carboxylic acid comprises propionic acid.
[0071] In another example, greater than 90 weight percent of the carboxylic acid is recovered in the organic extract phase and greater than 90 weight percent of the glycolic acid is recovered in the aqueous raffinate phase. In another example, the extracting of step (C) occurs in a continuous counter-current extractor, wherein the aqueous raffinate phase exits the bottom of the extractor and the organic extract phase exits the top of the extractor, the hydrophobic solvent is fed to the extractor below the hydrolyzed mixture, and the feed ratio of the hydrophobic solvent to the hydrolyzed mixture ranges from 0.5:1 to 4:1 on a weight basis. Additionally, a hydrophilic solvent can be fed to the extractor above the hydrolyzed mixture, wherein the feed ratio of the hydrophilic solvent to the hydrolyzed mixture ranges from 0.01:1 to 5:1 on a weight basis, and the feed ratio of the hydrophobic solvent to the hydrolyzed mixture ranges from 0.5:1 to 4:1 on a weight basis.
[0072] In another example of the process of the present invention, the aqueous formaldehyde comprises 35 weight percent to 85 weight percent formaldehyde, based on the total weight of the aqueous formaldehyde, the molar ratio of carbon monoxide to formaldehyde ranges from 1:1 to 10:1, and the hydrocarboxylation reaction zone is operated at a pressure of from 35 bar gauge to 200 bar gauge and a temperature of from 120° C. to 220° C.
[0073] In yet another example, the above process further comprises (E) separating the organic extract phase into the hydrophobic solvent and the carboxylic acid, recycling the hydrophobic solvent to step (C), and recycling the carboxylic acid to step (A); (F) reacting a first ethylene glycol with the aqueous raffinate phase while simultaneously removing water to produce an esterification effluent comprising glycolate ester oligomers and glycolic acid oligomers and an overhead stream comprising water; and (G) reacting hydrogen with the esterification effluent to produce a second ethylene glycol, separating the second ethylene glycol into a product ethylene glycol and the first ethylene glycol, recycling the first ethylene glycol to step (F).
[0074] The present invention provides in a third embodiment a process for the preparation of glycolic acid, comprising
(A) feeding carbon monoxide, aqueous formaldehyde, and carboxylic acid selected from at least one of the group consisting of 2-methyl butyric acid, n-valeric acid, and i-valeric acid to a hydrocarboxylation reactor zone comprising a solid acid catalyst to produce an effluent comprising esters of glycolic and carboxylic acids; (B) hydrolyzing the effluent to produce a hydrolyzed mixture comprising glycolic acid and the carboxylic acid; (C) separating the hydrolyzed mixture into a aqueous phase comprising glycolic acid and an organic phase comprising the carboxylic acid and recycling the carboxylic acid to step (A).
[0078] The examples of the first embodiment regarding aqueous formaldehyde, carboxylic acid, molar ratio of carboxylic acid to formaldehyde, carbon monoxide, hydrocarboxylation reaction zone process conditions, solid acid catalysts, esters of glycolic and carboxylic acids, hydrolyzing and hydrolyzed mixture composition, esterification of the glycolic acid and hydrogenation of the glycolate ester oligomers and glycolic acid oligomers to produce ethylene glycol apply to the third embodiment. The aqueous phase and the organic phase may be separated by any phase separation technology known in the art. Suitable liquid-liquid separation devices for the separation include, but are not limited to, coalescers, cyclones and centrifuges.
[0079] In an example, the third embodiment further comprising adding a hydrophobic solvent prior to step (C) and separating the hydrophobic solvent from the carboxylic acid prior to recycling the carboxylic acid to step (A). The hydrophobic solvent can be selected from ethers having from 4 to 20 carbon atoms and hydrocarbons having from 6 to 20 carbon atoms. In one aspect of the invention, the hydrophobic solvent comprises diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ethers, methyl tertiary-butyl ether, methyl tertiary-amyl ether, heptane, hexane, toluene, or mixtures thereof. In another aspect of the invention, the hydrophobic solvent comprises n-methyl tertiary-butyl ether, toluene, or mixtures thereof.
[0080] FIGS. 1 and 2 present two, non-limiting embodiments or the instant invention described herein in detail. In a first embodiment of the invention as laid out in FIG. 1 , Carbon Monoxide Stream 1 , Aqueous Formaldehyde Stream 2 , and Propionic Acid Stream 3 are fed to Hydrocarboxylation Reactor 50 which comprises a fixed bed, solid catalyst (not shown). The Effluent Stream 4 comprises the esters of glycolic and propionic acid including 2-propionoxyacetic acid and (2′-(propionyloxy)acetoxyacetic acid. Effluent Stream 4 and Water Stream 8 are fed to Hydrolyzer 55 . Hydrolyzer 55 is operated at sufficient temperature, pressure, and residence time to produce Hydrolyzed Mixture Stream 9 comprising glycolic acid, propionic acid, and water. Hydrolyzed Mixture Stream 9 is extracted with Hydrophobic Solvent Stream 11 , such as methyl tertiary-butyl ether, in Extractor 60 , to produce Organic Extract Stream 10 and Aqueous Raffinate Stream 12 . Organic Extract Stream 10 can be separated into Propionic Stream 3 and Hydrophobic Solvent Stream 11 in Separator 70 . Separator 70 can be, for example a distillation column. Propionic Acid Stream 3 is recycled to Hydrocarboxylation Reactor 50 and Hydrophobic Solvent Stream 11 is recycled to Extractor 60 .
[0081] Use of a hydrophobic solvent for extraction of the carboxylic acid from the hydrolyzed mixture is necessary if the carboxylic acid and aqueous glycolic acid does not phase separate and may be helpful to improve the separation even if not required to form two phases. In a second embodiment of the invention as set forth in FIG. 2 , Carbon Monoxide Stream 1 , Aqueous Formaldehyde Stream 2 , and Valeric Acid Stream 3 are fed to Hydrocarboxylation Reactor 50 which comprises a fixed bed, solid catalyst (not shown). The Effluent Stream 4 comprises the esters of glycolic and valeric acid including 2-valeryloxyacetic acid. Effluent Stream 4 and Water Stream 8 are fed to Hydrolyzer 55 . Hydrolyzer 55 is operated at sufficient temperature, pressure, and residence time to produce Hydrolyzed Mixture Stream 9 comprising glycolic acid, valeric acid, and water. Hydrolyzed Mixture Stream 9 is separated into two phases in Decanter 65 . The organic phase is recycled to Hydrocarboxylation Reactor 50 as Valeric Acid Stream 3 . Aqueous Glycolic Acid Stream 12 exits Decanter 65 and is fed, along with First Ethylene Glycol Stream 13 to Esterification Unit 80 . Water Stream 14 and Glycolate Ester Oligomer Stream 15 exit Esterification Unit 80 . Glycolate Ester Oligomer Stream 15 is hydrogenated using Hydrogen Stream 16 in Hydrogenation Unit 90 . Hydrogenation Unit 90 produces Second Ethylene Glycol Stream 17 which can be split into Ethylene Glycol Product Stream 18 and First Ethylene Glycol Stream 13 which is recycled to Esterification Unit 80 .
[0082] The invention can be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention.
EXAMPLES
[0083] The compounds and abbreviations given in Table 1 are used throughout the Examples section. Structures for each compound are also given.
[0000]
TABLE 1
Compound Names, Structures, and Abbreviation
Name
Structure
Code
Glycolic Acid
G1
(2- Hydroxyacetoxy)- acetic Acid
G2
2-(2′- Hydroxyacetoxy)- acetoxyacetic Acid
G3
2-(2′-(2″- Hydroxyacetoxy)- acetoxy)acetoxyacetic Acid
G4
Acetic Acid
A2
Acetoxyacetic acid
A2GH
Propionic Acid
A3
2-Propionoxyacetic Acid
A3GH
2-Propionoxyacetic Acid Oligomer
A3GnH n = 2 − 4
Valeric Acid
A5
2-Valeryloxyacetic Acid
A5GH
(2′-Valeryloxy)- acetoxyacetic Acid
A5G2H
[2′-(2″- Valeryloxy)acetoxy]- acetoxyacetic Acid
A5G3H
Formaldehyde
F0
Methylene Glycol
F1
Polymethylene glycol
Fn n = 2 − 10
Formic Acid
A1
Diglycolic Acid
DG
2-Methoxyacetic Acid
MGH
Methyl Glycolate
MG
Methylene Diacetate
MDA
Methylene Dipropionate
MDP
[0084] Materials—Acetic and propionic acids (99.5%), nonafluorobutanesulfonic acid and AMBERLYST 36 ion exchange resin were purchased from Aldrich Chemical Company. AMBERLYST resin, manufactured by Rohm & Hass Chemical Company, is crosslinked polystyrene beads that have been sulfonated. AMBERLYST 36D is <1.65% wet with 5.4 meq/g acid capacity and a recommended maximum operating temperature of 150° C. Sulfuric acid was purchased from J. T. Baker, trifluoromethanesulfonic acid (also known as triflic acid) and bis(trifluoromethylsulfonyl)amide were purchased from SynQuest Labs, Inc., tetrafluoroethanesulfonic acid was purchased from DuPont Chemical Company. Paraformaldehyde (90% min) was purchased from Kodak. Solid acid catalysts were received from suppliers as detailed below. All chemicals were used as received except as noted below.
[0085] Yield—Ultimately, the hydrocarboxylation process is used to produce glycolic acid. The crude product from a hydrocarboxylation reaction, which takes place in carboxylic acid, comprises the esters of glycolic and carboxylic acids. For example, when the carboxylic acid is propionic acid, the crude product comprises methyl glycolate (MG), glycolic acid (G1) and its oligomers (Gn, n=2-5) and 2-propionoxyacetic acid (A3 GH) and its oligomers (A3GnH, n=2-4). When a GC method was used, the yield of desired products was calculated based upon the total moles of glycolic acid moiety. The term “glycolic acid moiety,” as used herein, refers to the O—CH 2 —CO 2 segment of a molecule, for example, the segment in glycolic acid, a glycolic acid oligomer, or an ester of glycolic and carboxylic acids. The glycolic acid moieties divided by the moles of formaldehyde fed gives the yield. When an LC method was used, all of the glycolic acid moieties are converted to glycolic acid by the sample preparation. The yield was calculated simply as the moles of glycolic acid divided by the moles of formaldehyde fed.
[0086] Selectivity—Selectivities to glycolic acid were calculated as the total moles of desired product for GC method as given above or the total moles of glycolic acid for the HPLC method divided by moles of all products formed from formaldehyde such as formic acid, methyl glycolate, diglycolic acid, and others.
[0087] Gas Chromatography (GC) Method 1. Samples were analyzed using a Hewlett-Packard HP-5890 chromatograph equipped with split injectors and FIDs. The injector and detector port temperatures were 250° C. and 300° C., respectively. A DB-5 [(5% phenyl)-methylpolysiloxane] capillary column was employed. Hydrogen was used as the carrier gas with a column head pressure of 9 psig and a column flow of 1.6 ml/minute, which gave a carrier gas linear velocity of 43 cm/second. 0.5-μl of the prepared sample solution was injected with a split ratio of 40:1. The column temperature was programmed as follows: the initial oven temperature was set at 80° C. and was held for 3 minutes, the oven was then ramped up to 280° C. at a rate of 10° C./minute and was held at 280 for 7 minutes. Samples were prepared for gas chromatographic analysis according to the following procedure: 0.1±0.001 g of sample, 200.0 μl ISTD solution (1% by volume of decane in pyridine) and 1.0 ml of BSTFA (N,O-bis(tri-methylsilyl)trifluoroacetamide) with 1% TMSCl (trimethylchlorosilane) were heated in a vial at 80° C. for 30 minutes to ensure complete derivatization. A 0.5-μl sample of this derivatized solution was injected for GC analysis.
[0088] For a typical crude reaction product, 26 species were identified using GC/MS. For the example of propionic acid as the carboxylic acid, the desired products are methyl glycolate (MG), glycolic acid (G1) and its oligomers (Gn, n=2-5) and 2-propionoxyacetic acid (A3 GH) and its oligomers (A3GnH, n=2-4). Identified co-products include formic acid (A1), and diglycolic acid (DG). Unreacted starting materials are in the form of free formaldehyde (F0), methylene glycol (F1) and polymethylene glycol (Fn, n=2-10).
[0089] Gas Chromatography (GC) Method 2. The components of samples were first reacted with BSTFA in the presence of pyridine to the corresponding TMS-derivatives including water, which were then separated and quantified by an internal standard (decane or dodecane) wt % calibrated GC method. The volume ratio of sample to derivatization reagent (BSTFA) and pyridine (containing the internal standard compound) was 0.1 g:1 ml:0.2 ml in a GC vial, which was heated at 80° C. for 30 minutes to ensure complete derivatization. The GC method uses a DB-1301 capillary column or equivalent (6% cyanopropylphenyl/94% dimethylpolysiloxane stationary phase, 60 meters×0.32 mm ID×1.0 um film thickness), a split injector (at 280° C.), a flame ionization detector (at 300° C.), helium carrier gas at a constant linear velocity of 27 cm/sec (a Shimadzu GC 2010 or equivalent) or at an initial column head pressure of 17 psig, an oven temperature program of 80° C. initial temp for 6 min, 4° C./min temp ramp to 150° C. held for 0 min and 10° C./min temp ramp to 290° C. for 17.5 min final hold time. 1 μl of the prepared sample solution was injected with a split ratio of 40:1 Analytes include: MeOH, A1, water, heptane, toluene, G1 and higher oligomers, A5 GH and higher oligomers, DG, methyl valerate, and MG.
[0090] High Pressure Liquid Chromatography (HPLC) Method 1. Samples were prepared by pipetting 100 μl of sample into a 10 mL volumetric flask, adding a few mLs of water, ten drops of conc. H 3 PO 4 , and diluting to the mark with water. An aliquot of sample was injected onto an Agilent 1100 HPLC instrument for analysis using a BIORAD Fast Acid Analysis Column (100×7.8 mm) at 60° C. The sample is eluted using 10 mM sulfuric acid in water with a flow rate of 1 mL/min. Glycolic acid was detected at 210 nm on the UV detector. An external standard was used for calibration along with a dilution factor in a sequence table. The results are reported as ppm using a two-level calibration curve (100 and 1000 ppm) for each acid.
[0091] High Pressure Liquid Chromatography (HPLC) Method 2. Glycolic acid concentration was quantitatively determined by an Agilent 1100 HPLC using a Hamilton PRP-X300 exclusion column (250×4.1 mm). Glycolic acid was detected at 210 nm on the UV detector. Two eluents were used, where eluent A is 5 mM H 3 PO 4 in 1% acetonitrile/99% water and eluent B is 5 mM H 3 PO 4 in 10% acetonitrile/90% water. The following gradient was used: 100% A for 2 min; ->100% B 5 min; Hold for 3 mins; ->100% A 0.1 mins; equilibrate 4.9 mins for a total run time of 15 minutes. HPLC samples were prepared according to the following method. The samples of crude hydrocarboxylation reaction are hydrolyzed and diluted for analysis according to the following procedure: 200 mg of sample is weighed into a 10 mL volumetric flask, then 0.5 mL of 40% NaOH is added. After 10 minutes, 2 mL of water is added and the solution is allowed to sit for another 10 minutes. The solution is then diluted to the mark with water. A milliliter of this solution is then diluted tenfold before analysis.
[0092] High Pressure Liquid Chromatography (HPLC) Method 3. Samples were analyzed by liquid chromatography for glycolic acid using ion-exclusion chromatography after samples were subjected to acid hydrolysis in aqueous 25% v/v H 2 SO 4 at 80° C. for 30 minutes. The analytes were separated on a Hamilton PRP X300 column using a 10 mM H 3 PO 4 mobile phase with a 1-20% v/v acetonitrile gradient. The eluting components were monitored using a UV detector set at 210 nm and their concentrations calculated based on calibration using external standards. Formaldehyde was determined by liquid chromatographic separation of the 2,4-dinitrophenylhydrazone derivative of formaldehyde and its subsequent detection by UV at 360 nm. The same acid hydrolysate from the procedure above was reacted with dinitrophenylhydrazine, then analyzed using a Phenomenex Luna C8 column using a 1:1 water:acetonitrile mobile phase under isocratic conditions. The formaldehyde concentration was calculated based on calibration using external standards.
[0093] X-ray method for triflic acid. Reactor effluent and extraction samples were analyzed for sulfur using a wavelength dispersive x-ray fluorescence (WDXRF) semi-quantitative application called UNIQUANT™ (UQ). UQ affords standardless XRF analysis of samples. The data were mathematically corrected for matrix differences between calibration standards and samples as well as absorption and enhancement effects; i.e., inter-element effects. Instrument conditions for sulfur analysis were: Line, K a ; kV, 40; mA, 60; Filter, none; Collimator Spacing (mm), 150; Crystal, Ge III-C; Peak Angle (2q), 110.6712; Detector, flow; PHD Lower, 35; PHD Upper, 70; Collimator Mask (mm), 30; Peak time (s), 30. Sulfur weight fraction numbers were converted to triflic acid weight equivalents by the factor 4.68 (ratio of molecular weight of triflic acid to that of sulfur).
Example 1
[0094] 20% W-heteropoly/silica catalyst purchased from Johnson Matthey was used as received. A 50 mL Hastelloy 276C autoclave was heated with a heating block, with temperature control provided by feedback via a thermocouple in the autoclave thermowell. Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure regulator. The autoclave was charged with the paraformaldehyde (3.12 g, 0.099 mol), propionic acid (30.74 g, 0.41 mol), 20% W-heteropoly/silica catalyst (1.9 g), assembled, and pressurized with 200 psig of nitrogen and vented. This purging procedure was repeated two times. To remove nitrogen from the autoclaves, they were purged with 200 psig of carbon monoxide. Then the reactors were pressurized with 200 psig of carbon monoxide and heated with stirring to 140° C. The reactor was then pressurized to 1000 psig carbon monoxide and the pressure was maintained from the surge tank. After a 2 hour hold time, the reactor was cooled to room temperature and vented. Finally the autoclave was purged with nitrogen and unloaded. The reaction content was analyzed by GC and/or HPLC. Table 2 gives the yield.
Examples 2-7
[0095] Example 1 was repeated using the catalyst and catalyst loading and hold time given in Table 2. The resulting yields are also given in Table 2.
[0096] For Examples 4 and 5, the AMBERLYST catalyst preparation was as follows. The resin was washed up-flow with six bed volumes of ambient temperature distilled water over a period of 15 minutes. The washed resins were then dried in a vacuum oven at 109° C. and placed in a desiccator until needed.
[0097] For Examples 6 and 7 the SMOPEX 101 catalyst preparation was as follows. To 20 g of SMOPEX catalyst, in 250 mL beaker, 50 mL of propionic acid was added. The catalyst was allowed to sit for 15 min and then filtered using vacuum filtration. The vacuum was turned off and 20 mL of propionic acid was passed through the catalyst. This step was repeated three times to ensure that all of the water was washed off of the catalyst. Finally the solid was dried under house vacuum overnight.
[0000]
TABLE 2
Hydrocarboxylation of Paraformaldehyde in Propionic Acid Catalyzed
by Strongly Acidic Solid Acid Catalysts.
loading
temp
time
yield
EX
catalyst
(wt %)
(° C.)
(h)
(%)
1
20% W-heteropoly/silica
5.1
140
2
2.1
2
SiO 2 /Al 2 O 3
5
140
2
2.6
3
SAC-13
15
140
3
82.3
4
AMBERLYST 36 (5.4 mmol/g)
5.0
140
2
71.1
5
AMBERLYST 36 (5.4 mmol/g)
5.0
140
3
75.7
6
SMOPEX 101 (4% crosslinked)
5.0
140
3
61.4
7
SMOPEX 101 (12% crosslinked)
5.0
140
3
69.4
[0098] The following examples demonstrate the effect of pressure, temperature, and water content on the batch hydrocarboxylation of paraformaldehyde in propionic acid using a dry AMBERLYST 36 solid acid catalyst.
Example 8
[0099] A 300 ml Hastelloy 276C autoclave was charged with paraformaldehyde (15.99 g, 0.53 mol), dry AMBERLYST 36 catalyst (9.3 g), propionic acid (157.9 g, 2.13 mol), and formic acid (3.8 g). The autoclave was then assembled and pressurized with 200 psig of N 2 and vented. This purging procedure was repeated two times. The autoclave was purged with 200 psig carbon monoxide in order to remove N 2 . The reactor was pressurized with carbon monoxide to 500 psig and heated with stirring to 100° C. Once the desired temperature was reached, the reactor was pressurized to 1500 psig carbon monoxide and the pressure of the autoclave was maintained from a surge tank. Samples of the reaction were taken over the duration of the experiment at approximately 0.5, 1, 1.5, 2, 2.5, and 3 hours. When the reaction time was complete, the reactor was cooled to room temperature and vented. The autoclave was purged with nitrogen and the product mixture removed. The samples were analyzed by GC. The temperature and pressure; the weight percent paraformaldehyde, propionic acid, and water; and the yield of desired products and selectivity are given in Table 3. The concentration of formic acid ranged from 2.2 weight percent to 2.4 weight percent.
Examples 9-32
[0100] Example 8 was repeated for examples 9-32 with no water, as in Example 8, or water (nominally 4.58 g, 0.5 eq.), or water (nominally 9.12 g, 1.0 eq.) with formic acid added at an amount of 2.0 wt % of the charged composition. The feed composition as well as the temperature and pressure of the reactor are as noted in Table 3. The temperature and pressure; the weight percent paraformaldehyde, propionic acid, and water; and the yield of desired products and selectivity are given in Table 3.
[0000]
TABLE 3
Hydrocarboxylation of Paraformaldehyde in Propionic Acid Catalyzed by
AMBERLYST 36D (4.6-4.8 wt %).
Yield of
desired
Pressure
Temperature
Feed (wt %)
products
Selectivity
EX
(psig)
(° C.)
F0
A3
Water
Time (h)
(%)
(%)
8
1,500
100
9.0
88.8
0.0
0.5
14
53
1.0
29
68
1.5
43
73
2.0
53
79
2.5
64
85
3.0
71
88
9
1,000
100
9.0
88.8
0.0
0.5
25
63
1.0
42
72
1.5
62
83
2.0
73
99
2.5
81
100
3.0
86
101
10
500
100
9.0
88.8
0.0
0.5
11
100
1.0
20
99
1.5
27
95
2.0
36
88
2.5
45
84
3.0
53
81
11
1,500
100
8.6
84.4
4.9
0.5
2
79
1.0
2
81
1.5
3
83
2.0
10
80
2.5
11
82
3.0
12
89
12
1,000
100
8.5
84.4
4.9
0.5
7
84
1.0
7
69
1.5
8
69
2.0
9
68
2.5
10
65
3.0
12
66
13
500
100
8.6
84.4
4.9
0.5
5
83
1.0
5
82
1.5
6
91
2.0
1
80
2.5
7
85
3.0
8
71
14
750
100
8.6
84.4
4.9
0.5
5
78
1.0
6
75
1.5
7
73
2.0
7
70
2.5
8
70
3.0
9
66
15
750
100
9.0
88.8
0.0
0.5
12
95
1.0
24
92
1.5
28
96
2.0
37
81
2.5
46
87
3.0
54
85
16
500
100
8.8
86.6
2.5
0.5
7
99
1.0
8
93
1.5
9
90
2.0
10
86
2.5
13
85
3.0
15
82
17
750
100
8.8
86.6
2.5
0.5
8
89
1.0
10
96
1.5
13
87
2.0
16
91
2.5
19
83
3.0
23
91
18
1000
100
8.8
86.6
2.5
0.5
6
102
1.0
7
113
1.5
7
108
2.0
7
104
2.5
9
101
3.0
12
82
19
1,500
100
8.8
86.6
2.5
0.5
10
80
1.0
13
79
1.5
17
79
2.0
20
80
2.5
24
80
3.0
28
80
20
1,500
100
9.0
88.8
0.0
0.5
17
94
1.0
31
81
1.5
44
82
2.0
58
89
2.5
68
90
3.0
75
92
21
500
100
9.0
88.8
0.0
0.5
9
73
1.0
12
87
1.5
17
85
2.0
21
81
2.5
24
81
3.0
28
81
22
1,500
100
8.6
84.4
4.9
0.5
4
27
1.0
4
28
1.5
5
28
2.0
6
24
2.5
6
24
3.0
7
26
23
500
100
8.5
84.4
4.9
0.5
1
77
1.0
6
87
1.5
6
80
2.0
6
80
2.5
7
75
3.0
8
76
24
1000
100
8.8
86.6
2.5
0.5
6
77
1.0
10
82
1.5
12
90
2.0
13
87
2.5
19
90
3.0
21
90
25
500
140
9.0
88.8
0.0
0.5
45
81
1.0
63
85
1.5
77
99
2.0
78
104
2.5
78
106
3.0
79
108
26
1,500
140
8.6
84.4
4.9
0.5
38
75
1.0
48
78
1.5
59
83
2.0
65
90
2.5
68
92
3.0
69
92
27
1,000
120
8.6
86.6
2.5
0.5
16
68
1.0
24
70
1.5
32
70
2.0
39
86
2.5
48
87
3.0
52
89
28
500
140
8.6
84.4
4.9
0.5
20
63
1.0
32
65
1.5
40
69
2.0
54
76
2.5
48
79
3.0
52
82
29
1,500
140
9.0
88.8
0.0
0.5
67
97
1.0
82
100
1.5
75
102
2.0
84
107
2.5
84
108
3.0
84
108
30
2,000
140
9.0
88.9
0.0
0.5
78
97
1.0
83
100
1.5
84
102
2.0
85
103
2.5
86
104
3.0
87
104
31
2,000
140
8.6
84.5
4.9
0.5
38
77
1.0
61
84
1.5
71
87
2.0
76
89
2.5
77
90
3.0
79
91
32
2,000
140
8.8
86.6
2.5
0.5
60
86
1.0
72
91
1.5
78
93
2.0
80
94
2.5
79
95
3.0
80
95
[0101] The following examples demonstrate the hydrocarboxylation of paraformaldehyde using a triflic acid catalyst in acetic, propionic, n-butyric, i-butyric, valeric, and hexanoic acids.
Example 33
[0102] A 100 mL zirconium high pressure autoclave was fitted with an impeller, gas inlet tube, sample tube, and thermowell. The autoclave was heated with a heating block, with temperature control provided by feedback via a thermocouple in the autoclave thermowell. Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure regulator. Triflic acid (0.562 g, 3.7 mmol), acetic acid (30.03 g, 0.5 mol) and paraformaldehyde (3.94 g, 0.125 mol) were added to the autoclave and sealed. The autoclave was secured to the stand and the system was purged with carbon monoxide and pressurized to 250 psig carbon monoxide. The temperature in the autoclave was increased to 140° C. while stirring at 1000 rpm. Upon reaching 140° C., the pressure in the autoclave was increased to 1,000 psig carbon monoxide. Once temperature and pressure were reached, a sample was taken, “time 0.” The pressure and temperature were maintained for 4 hours. Subsequent samples of the reaction were taken at approximately 15, 30, 45, 60, 90, 120, 180 and 240 minutes and analyzed by HPLC. Results are given in Table 4, in terms of yield of glycolic acid and selectivity.
Example 34
[0103] Example 33 was repeated except that propionic acid (37.04 g, 0.5 mol) was charged to the autoclave in place of acetic acid. Results are given in Table 4.
Example 35
[0104] Example 33 was repeated except that n-butyric acid (44.06 g, 0.5 mol) was charged to the autoclave in place of acetic acid. Results are given in Table 4.
Example 36
[0105] Example 33 was repeated except that i-butyric acid (44.06 g, 0.5 mol) was charged to the autoclave in place of acetic acid. Results are given in Table 4.
Example 37
[0106] Example 33 was repeated except that valeric acid (51.07 g, 0.5 mol) was charged to the autoclave in place of acetic acid. Results are given in Table 4.
Example 38
[0107] Example 33 was repeated except that hexanoic acid (58.08 g, 0.5 mol) was charged to the autoclave in place of acetic acid. Results are given in Table 4.
[0000]
TABLE 4
Hydrocarboxylation of Paraformaldehyde in Carboxylic
Acids Catalyzed by Triflic Acid.
EX
Carboxylic Acid
Time (h)
Yield (%)
Selectivity (%)
33
Acetic Acid
0
14.1
79.2
0.3
45.9
92.0
0.5
84.1
93.5
0.8
92.8
96.5
1.0
97.2
95.8
1.3
96.5
95.8
1.8
98.9
97.1
3.0
98.3
99.4
4.0
99.9
98.2
34
Propionic Acid
0
7.5
45.1
0.3
28.1
74.6
0.5
59.9
87.1
0.8
74.1
89.7
1.0
76.4
90.6
1.5
81.9
92.4
2.4
85.9
94.0
2.8
84.9
94.8
4.0
83.4
94.2
35
n-butyric acid
0
10.2
74.9
0.3
40.8
87.1
0.5
70.0
94.2
0.8
90.8
97.5
1.0
89.9
97.2
1.3
97.3
97.9
1.8
101.1
97.6
3.0
104.4
98.3
4.0
104.1
98.2
36
i-butyric
0
9.8
67.6
0.3
21.7
78.8
0.5
40.1
82.6
0.8
46.9
84.7
1.0
52.7
86.8
1.5
57.8
88.5
2.4
67.0
92.5
2.8
66.8
92.3
4.0
65.6
93.3
37
Valeric Acid
0
9.5
64.5
0.3
28.4
72.6
0.5
55.0
87.2
0.8
69.1
92.2
1.0
82.9
100.0
1.3
94.4
99.5
1.8
96.0
100.0
3.0
99.3
98.5
4.0
100.8
100.0
38
Hexanoic Acid
0
7.9
42.2
0.3
20.9
55.0
0.5
41.7
71.4
0.8
54.5
77.5
1.0
65.0
83.3
1.3
73.9
87.9
1.8
77.9
92.9
3.0
81.8
94.2
4.0
84.5
97.2
[0108] For all extraction examples the partition coefficient for component A is defined as follows:
[0000]
P
(
A
)
=
Weight
Percent
A
in
Hydrophobic
phase
Weight
Percent
A
in
Hydrophilic
phase
[0109] Extraction selectivity between components A and B is defined as:
[0000] S ( AB )= P ( A )/ P ( B )
Example 39
[0110] A first standard aqueous acetic-glycolic acid solution was prepared by mixing glycolic acid, water, and acetic acid. Fifteen grams of this first standard solution was added to a separate glass vial along with fifteen grams of each of the nonpolar solvents listed in Table 5. A second standard aqueous propionic-glycolic acid solution was prepared and fifteen grams of this second standard solution was added to a separate glass vial along with fifteen grams of each of the nonpolar solvents listed in Table 5. The contents of each vial were mixed vigorously and allowed to settle and separate into two clear phases. All experiments were conducted at room temperature. The phases were analyzed by GC to determine acetic acid, propionic acid, and glycolic acid compositions. These analytical results were used to calculate partition coefficients and extraction selectivities. Results are summarized in Table 5. The partition coefficients and selectivities for propionic acid are higher than the corresponding values for acetic acid, thus illustrating the value of using propionic acid instead of acetic acid as a hydrocarboxylation solvent/reactant.
[0000]
TABLE 5
Extraction Compositions, Partition Coefficients and Selectivities for
Mixtures Containing Acetic Acid and Propionic acid.
acid
glycolic
water
solv.
P
P
S
Ex.
Solvent
acid
(g)
(g)
(g)
(g)
(acid)
(glycolic)
(acid/glycolic)
39a
Toluene
acetic
3.6
2.4
9
15
0.08
<0.001
>80
39b
Heptane
acetic
3.6
2.4
9
15
0.02
<0.001
>20
39c
methyl
acetic
3.6
2.4
9
15
0.80
0.14
6
propionate
39d
MTBE
acetic
3.6
2.4
9
15
1.00
0.07
14
39e
Toluene
propionic
3.6
2.4
9
15
0.70
<0.001
>70
39f
Heptane
propionic
3.6
2.4
9
15
0.10
<0.011
>10
39g
methyl
propionic
3.6
2.4
9
15
2.50
0.16
16
propionate
39h
MTBE
propionic
3.6
2.4
9
15
3.40
0.09
38
Examples 40-50
[0111] These examples illustrate the selective extractive separation of n-valeric, n-butyric (nHOBu), iso-butyric (iHOBu), and propionic (HOPr) acids from highly concentrated aqueous glycolic acid. Aqueous glycolic acid-water-carboxylic acid mixtures were prepared and added to separate glass vials along with the amount of each hydrophobic solvent as listed in Table 6. The contents of each vial were mixed vigorously and allowed to settle and separate into two clear phases. All experiments were conducted at room temperature. The phases were analyzed by GC to determine carboxylic acid and glycolic acid compositions. These analytical results were used to calculate partition coefficients and selectivities. Results are summarized in Table 6.
[0000]
TABLE 6
Extraction compositions, Partition Coefficients and Selectivities.
acid
glycolic
water
solv.
P
P
S
Ex.
Solvent
acid
(g)
(g)
(g)
(g)
(acid)
(glycolic)
(acid/glycolic)
40
Toluene
n-butyric
10
8
2
10
5.2
0.035
148.8
41
MTBE
n-butyric
10
8
12
15
7.4
0.189
39.4
42
Heptane
n-butyric
10
8
2
10
3.4
0.015
220.4
43
Toluene
i-butyric
10
8
2
10
7.4
0.027
271.6
44
MTBE
i-butyric
10
8
11
15
8.3
0.176
46.9
45
Heptane
i-butyric
10
8
2
10
6.7
0.011
626.6
46
Toluene
propionic
10
8
2
10
1.9
0.056
34.5
47
MTBE
propionic
10
8
12
15
2.2
0.341
6.6
48
MIBK
propionic
10
8
12
15
2.0
0.303
6.6
49
heptane
n-valeric
8
6
2
4
8.2
0.0001
5,672.1
50
toluene
n-valeric
8
6
2
4
13.5
0.030
446.6
Examples 51-58
[0112] These examples illustrate the effect of glycolic acid content on the extractive separation of n-valeric acid from glycolic acid. Aqueous glycolic acid-water-n-valeric acid mixtures were prepared and added to separate glass vials along with the amount of toluene or heptane as listed in Table 7. The contents of each vial were mixed vigorously and allowed to settle and separate into two clear phases. All experiments were conducted at room temperature. The phases were analyzed by GC to determine n-valeric acid and glycolic acid compositions. These analytical results were used to calculate partition coefficients and selectivities as shown in Table 7.
[0000]
TABLE 7
Extraction Compositions, Partition Coefficients and Selectivities.
wt. %
acid
glycolic
water
solv.
P
P
S
Ex.
solvent
glycolic
(g)
(g)
(g)
(g)
(acid)
(glycolic)
(acid/glycolic)
51
toluene
75
8
5.99
2.00
4.00
329
0.44
748.2
52
toluene
50
8.00
4.01
4.01
4.02
636
0.31
2,041.3
53
toluene
25
7.98
2.01
6.02
3.99
763
0.18
4,183.8
54
toluene
0
7.97
0.00
8.15
4.03
1,319
NA
NA
55
heptane
75
8.09
6.06
2.02
4.04
8.0
0.006
1,419.3
56
heptane
50
8.02
4.05
4.05
4.01
12.4
0.006
2,099.0
57
heptane
25
8.11
2.01
6.04
4.04
15.0
0.004
3,767.9
58
heptane
0
8.03
0.00
8.02
4.19
18.9
NA
NA
Examples 59-62
[0113] These examples illustrate the effect of glycolic acid content on the extractive separation of valeric acid from triflic acid and glycolic acid. Aqueous glycolic acid-water-triflic acid mixtures were prepared and added to separate glass vials along with the amount of toluene and valeric acid as listed in Table 8. The contents of each vial were mixed vigorously and allowed to settle and separate into two clear phases. All experiments were conducted at a temperature of 50° C. The phases were analyzed by GC and X-ray to determine valeric, triflic acid, and glycolic compositions. These analytical results were used to calculate partition coefficients and selectivities as shown in Table 8.
[0000]
TABLE 8
Extraction Compositions, Partition Coefficients and Selectivities of
Valeric Acid, Triflic Acid and Glycolic Acid in Toluene.
Acid
glycolic
water
solv.
triflic
P
P
P
S
S
Ex.
(g)
(g)
(g)
(g)
(g)
(acid)
(glycolic)
(triflic)
(acid/glycolic)
(acid/triflic)
59
1.07
0.00
9.72
9.00
0.30
13.7
NA
0.0002
NA
57,499
60
4.00
0.00
7.77
7.99
0.24
38.0
NA
0.001
NA
38,376
61
1.02
7.79
1.95
9.02
0.30
2.0
0.001
0.0001
1,388.1
20,302
62
4.03
6.23
1.56
8.03
0.24
4.2
0.031
0.0012
136.6
3,414
Example 63
[0114] A solution rich in esters of glycolic and valeric acids was prepared by mixing 1.45 moles of valeric acid per mole of glycolic acid. This mixture was heated to reflux under vacuum to remove approximately 0.2 grams of water per gram of glycolic acid fed, to give an average degree of oligomerization of 0.84 ester bonds per mole of glycolic acid (i.e., mostly A5 GH). This source of A5 GH was used in Examples 63 and 64.
[0115] A feed was produced by mixing the source of A5 GH above with triflic acid and heptane to give the feed composition listed in Table 9. This example illustrates a simulated continuous extraction of a feed containing esters of glycolic and valeric acids, triflic acid, and heptane with a hydrophilic solvent containing 20% aqueous glycolic acid for separation of Triflic acid from A5 GH. The feed mixture was subjected to a cascaded series of twenty-four cross-flow batch extractions to simulate a six-stage continuous counter-current extraction process, with the feed mixture (20.0 g) introduced on stage six (from the top) and the aqueous glycolic acid solvent (8.0 g) on stage one (top of extractor). The multi-cycle, cascaded pattern of 24 extractions in which one feed mixture charge is added into the first cycle of the cascade, and multiple hydrophilic solvent charges are introduced into each cycle of the cascade, and with raffinate and extract compositions introduced to the next cycle of the cascade, results in a set of conditions on the final cycle which have been shown to closely approach the equilibrium composition profile of a continuous, staged, counter-current fractional extractor. For this work, three cycles were found to be sufficient to asymptotically approach continuous extraction equilibrium conditions. The simulated counter-current extraction technique used herein is well-known to those skilled in the art and is laid out in detail in Treybal (“Liquid Extraction,” 2nd Ed., McGraw-Hill Book Company, New York, N.Y., 1963, pp. 349-366). The feed contained 10 weight percent hydrophobic solvent. The hydrophilic solvent (aqueous glycolic acid) to feed (including the heptane) weight ratio was 0.4:1.0. The experiment was conducted at room temperature. The final simulated raffinate (19.24 g—top product) and extract (8.58 g—bottom product) streams were subjected to GC and X-ray analysis to determine the compositions of the products. Results are given in Table 9 with all percentages representing weight percent. The percent recovery to the extract is based on the amount of each component in all inputs to the extractor. The percent accountability of each component is equal to total out/total in as a percentage.
[0000]
TABLE 9
Simulated Extraction Results
Aq G1
Recovery to
Solvent
Feed
Extract
Raffinate
%
Extract
(%)
(%)
(%)
(%)
Account
(%)
Water
80.0
2.1
59.9
7.4
97
78.2
Heptane
0.0
10.0
0.3
10.1
99
1.2
A5
0.0
46.5
13.1
45.1
106
11.4
G1
20.0
3.5
14.1
5.6
100
52.4
A5GH
0.0
29.0
5.6
27.1
99
8.4
G2
0.0
1.1
1.0
0.1
48
86.5
A5G2H
0.0
4.2
0.2
3.5
81
2.6
Triflic
0.0
2.0
4.6
0.0
100
99.2
Other
0.0
1.7
1.2
1.2
90
32.3
Example 64
[0116] Example 63 was repeated using a feed produced by mixing the source of A5 GH above with triflic acid to give the feed composition listed in Table 10 with the feed (20.0 g) introduced on stage three (from the top), the hydrophobic solvent (10.0 g), toluene, introduced on stage six (from the top), and the hydrophilic solvent or water wash (8.0 g) introduced on stage one (from top). The final simulated raffinate (11.4 g—hydrophobic product) and extract (26.6 g—hydrophilic product) streams were subjected to GC and X-ray analysis to determine the compositions of the products. Results are given in Table 10.
[0000]
TABLE 10
Simulated Extraction Results
Hydrophilic
Hydrophilic
Hydrophobic
Product
Hydrophobic
% Recovery to
Feed
Solvent (%)
Solvent (%)
(%)
Product (%)
extract
Toluene
0.00
100.0
0.23
37.32
0.26
Water
1.26
100.0
69.53
8.37
78.07
Triflic
2.20
3.83
<0.001
>99.94
G1
5.47
25.22
0.43
96.16
A5
39.16
0.72
23.51
1.30
A5GH
50.58
0.06
29.86
0.09
other
1.33
0.41
0.51
not determined
TOTAL
100.0
100.0
100.0
100.0
100.0%
Example 65
[0117] Example 65 illustrates a continuous extraction demonstration of the recovery of triflic acid from a esters of glycolic and valeric acids feed stream derived from the hydrocarboxylation of formaldehyde using a hydrophilic solvent comprising 70 wt % G1, 30 wt % water and a hydrophobic solvent comprising 100 wt % toluene. This extraction was carried out in a Karr column comprising four jacketed glass column sections (15.9 mm inside diameter, each 501 mm in length) stacked on top of each other. Jacketed glass disengagement sections, 25.4 mm inside diameter and 200 mm in length, were attached to the top and bottom of the four extractor sections. The four column sections and two disengagement sections were joined together with Teflon O-ring gaskets (25 mm thickness) held together with bolted flanges to form the column body. Feed ports were fitted into each Teflon O-ring to allow change of feed locations. The total height of the resulting column was approximately 2.6 meters. Separate temperature-controlled heating baths were connected to the jacket of each disengagement zone and one bath to the combined four column sections to maintain the desired extraction temperature gradient.
[0118] Agitation in the column was supplied by an 3.2 mm diameter Hastelloy 276C impeller shaft fitted with seventy-seven Teflon plates, each with eight radial rectangular petals (to provide gaps for liquid flow paths), spaced 25 mm apart in the column sections. The impeller shaft was attached at the top of the extractor to an electric motor fitted with a concentric gear to convert rotational motion into reciprocal motion. The agitator stroke length (i.e., extent of vertical motion) was 19 mm, and varied from 200 to 350 strokes per minute.
[0119] Depending on the chosen continuous phase, the liquid-liquid phase interface was maintained in either the top or bottom disengagement section (in the top section if the less dense phase were continuous, bottom section if the more dense phase were continuous) by visual observation and manual manipulation of the underflow take-off pump.
[0120] Up to three feeds could be supplied to the column via piston pumps from independently temperature-controlled jacketed glass vessels of four liter, two liter, and two liter volumes, while the underflow (more dense) product and the top, overflow (less dense) product were collected in two-liter glass vessels. The top product collected by gravity overflow from the upper disengagement section, while the bottoms product flow was controlled by a variable rate piston pump.
[0121] Feed locations are designated as follows from the top of the column to the bottom:
[0122] F1: Feed location between top disengagement zone and 1st column section
[0123] F2: Feed location between 3 rd and 4 th column sections
[0124] F3: Feed location between 4 th column section and bottom disengagement zone
[0125] The column was operated continuously for five hours. The feed was the combined crude hydrocarboxylation reactor product produced in Examples 137 and 138 discussed below. The crude hydrocarboxylation reactor product was fed at feed location F2, the hydrophilic solvent (70% glycolic acid and 30 wt % water) fed at F1 and the hydrophobic solvent fed at F3. The hydrophilic solvent to feed ratio was held at 0.124 to 1 on a mass basis, and the hydrophobic solvent to valerate-triflic feed mass ratio was held at 0.59. These conditions resulted in greater than 99.0% of the triflic acid being recovered in the polar extract (aqueous extract). Results from this extraction are tabulated below in Table 11. All values are in weight percent.
[0126] Triflic acid is recovered in the hydrophilic product stream (extract) at a rate of 99%. About 21.2% of all G1 moieties in the valerate-triflic feed and hydrophilic solvent were recovered to the hydrophobic raffinate phase, but subtracting out G1 entering in the hydrophilic solvent, the recovery of G1 moieties in the valerate-triflic feed rises to 68.3%. Furthermore, since the original feed to the hydrocarboxylation reaction resulting in the crude hydrocarboxylation product from Examples 137 and 138, contained G1, the extraction actually resulted in essentially complete recovery of new G1 moieties created in the reaction Examples 137 and 138. Thus, such an extraction is capable of fully separating triflic acid from valerate-glycolic esters and producing a concentrated triflic acid-glycolic acid stream suitable for recycle to hydrocarboxylation.
[0000]
TABLE 11
Karr Column Continuous Extraction
Hydrophilic
Hydrophobic
Hydrophilic
Hydrophobic
Mass
Recovery
Feed
Solvent
Solvent
Extract
Raffinate
Balance
to Extract
Triflic Acid
2.93
7.74
0.023
100.4
99.0%
G1
13.30
70
46.40
3.50
100.9
78.8%
DGA
5.40
13.30
1
117.5
78.8%
A5
37
6.80
25.50
99.5
7.0%
A5GH
26
6.30
17.50
99.5
9.2%
A5G2H
7
1.40
5.07
104.8
7.2%
A5G3H
2
0.40
1.26
92.1
8.2%
Others
1.47
7.36
0.06
193.6
97.3%
Water
4.90
30%
10.30
3.55
100.3
44.8%
Toluene
100%
3.60
42.54
99.0
2.3%
Total
100.0
100.0
100%
100.0
100.0
100.3
Flowrate,
10.5
1.3
6.2
3.95
14.1
g/min
[0127] The following examples illustrate the hydrocarboxylation of either MDA in acetic acid or MDP in propionic acid catalyzed by strongly acidic solid acid catalysts.
Example 66
[0128] MDA (methylene diacetate) or MDP (methylene dipropionate) used in the following Examples were produced from a refluxing mixture of paraformaldehyde and acetic or propionic anhydride in the presence of a small amount of sulfuric acid. The reactions were followed by gas chromatography. Upon completion of the reaction, sodium acetate (NaOAc) or propionate were added to the mixture to neutralize the sulfuric acid. The mixture was distilled to give 99% pure methylene dicarboxylate. The following procedure for methylene diacetate is exemplary: A 5 L round-bottom flask was fitted with a condenser, thermowell, overhead stirrer, inert gas bubbler, and heating mantle. To this flask was added 885 grams of paraformaldehyde followed by 3,324 mL of acetic anhydride. The mixture was then stirred at room temperature and 12 mL of concentrated sulfuric acid was added. An exotherm heated the solution to approximately 80° C. and then the heating mantle was turned on. The mixture was held at reflux for almost 10 hours and sampled periodically to check for completion by gas chromatography. Upon completion, 35 g of NaOAc was added to the mixture to neutralize the sulfuric acid. The mixture was then transferred to another flask along with the NaOAc and pure MDA was distilled.
Example 67
[0129] A 50 mL Hastelloy 276C high pressure autoclave was fitted with an impeller, gas inlet tube, sample tube, and thermowell. The autoclave was heated with a heating block, with temperature control provided by feedback via a thermocouple in the autoclave thermowell. Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure regulator. The autoclave was charged with 20% W-heteropoly/silica catalyst (1.48 g) propionic acid (12.28 g, 0.16 mol) and MDP (14.1 g, 0.08 mol) and water (1.4 g, 0.08 mol) and sealed. The autoclave was secured to the stand and the system was pressurized with 200 psig nitrogen and vented. This purging procedure was repeated two times. The autoclave was then purged with carbon monoxide and pressurized to 200 psig carbon monoxide. The temperature in the autoclave was increased to 140° C. Upon reaching 140° C., the pressure in the autoclave was increased to 1,000 psig carbon monoxide. The reaction was held at these conditions for 2 hours and then cooled to room temperature and vented. Finally the autoclave was purged with nitrogen and unloaded. The reaction contents were analyzed by GC. Results are shown in Table 12.
Examples 68-83
[0130] The procedure of Example 67 was repeated using either MDP/propionic acid or MDA/acetic acid and water at target equivalents of 1 eq. of MDA(MDP), 2 eq. acetic (propionic) acid, and 1 eq. water at a reaction pressure of 1000 psig carbon monoxide. The examples were run with the solid catalyst and corresponding loading, at the temperature, and for the holding time shown in Table 12. Calculated yields are also given in Table 12.
[0000]
TABLE 12
Hydrocarboxylations of Methylene Diacetate (MDA) or Methylene
Dipropionate (MDP) Catalyzed by Strongly Acidic Solid
Acid Catalysts.
loading
temp
time
yield
EX
catalyst
(wt %)
(° C.)
(h)
(%)
67
MDP
20% W-heteropoly/silica
5
140
2
6.5
68
MDP
SiO 2 /Al 2 O 3
5
140
2
2.0
69
MDA
K10
5
140
2
3.8
70
MDA
AMBERLYST 70
5
140
2
18.8
71
MDA
SAC-13
9
140
1
47.8
72
MDA
SAC-13
9
160
1
69.8
73
MDA
SAC-13
9
180
1
78.8
74
MDA
Nafion NR50
5
140
2
69.4
75
MDA
SAC-13
15
160
1
98.6
76
MDA
polymer-bound pTSA
5
140
2
66
77
MDA
AMBERLYST 36
5
140
2
77
78
MDA
SMOPEX (4% crosslinking)
5
140
3
65
79
MDA
SMOPEX (8% crosslinking)
5
160
2
70
80
MDA
SMOPEX (12% crosslinking)
5
180
2
66
81
MDP
AMBERLYST 36
5
140
2
86
82
MDP
SAC-13
10
140
2
76
83
MDP
SMOPEX (4% crosslinking)
5
140
2
68
Examples 84
[0131] A 50 mL Hastelloy 276C high pressure autoclave was fitted with an impeller, gas inlet tube, sample tube, and thermowell. The autoclave was heated with a heating block, with temperature control provided by feedback via a thermocouple in the autoclave thermowell. Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure regulator. The autoclave was charged with AMBERLYST 36 D catalyst (1.43 g), propionic acid (12.3 g, 0.166 mol), MDP (14.1 g, 0.088 mol), and water (1.5 g, 0.083 mol) and sealed. The autoclave was secured to the stand and the system was pressurized with 200 psig nitrogen and vented. This purging procedure was repeated two times. The autoclave was then purged with carbon monoxide and pressurized to 500 psig carbon monoxide. The temperature in the autoclave was increased to 140° C. Upon reaching 140° C., the pressure in the autoclave was increased to 1,000 psig carbon monoxide. The reaction was held at these conditions for 2 hours and then cooled to room temperature and vented. Finally the autoclave was purged with nitrogen and unloaded. The reaction contents were analyzed by GC. The results are shown in Table 13.
Examples 85-91
[0132] Example 84 was repeated with the catalyst and catalyst loading and amount of propionic acid and water given in Table 13. Each reaction was run at 1000 psig carbon monoxide and at the temperature and for the time indicated in Table 13. Yield to desired products and selectivity are also given in Table 13.
[0000]
TABLE 13
Hydrocarboxylations of MDP
Loading
Water
Temp
Time
Yield
Select.
Ex.
Catalyst
(wt %)
A3 (eq)
(eq)
(° C.)
(h)
(%)
(%)
84
AMBERLYST 36 D
5
2.0
1.0
140
2
96
96
85
AMBERLYST 36 D
8
0.14
1.1
140
2
89
94
86
AMBERLYST 36 D
5
2.1
1
140
2
86
96
87
AMBERLYST 36 D
5
1.1
1
140
2
78
95
88
AMBERLYST 36 D
5
0.15
1
140
2
72
94
89
AMBERLYST 36 D
5
2
0.05
140
2
2
28
90
AMBERLYST 36 D
5
2
0.05
90
2
3
5
91
AMBERLYST 36 D
5
2
0.5
140
2
16
66
[0133] The following examples illustrate the hydrocarboxylation of MDA in acetic acid catalyzed by various strongly acidic homogeneous catalysts. MDA was prepared as described above in Example 66.
Example 92
[0134] To a Hastelloy 276C 300 mL autoclave equipped with a liquid sampling loop and a high pressure addition funnel was added acetic acid (60.05 g, 1.0 mol), water (9.0 g, 0.5 mol), and trifluoromethanesulfonic acid catalyst (0.375 g, 2.5 mmol). The autoclave was heated with a heating block, with temperature control provided by feedback via a thermocouple in the autoclave thermowell. Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure regulator. The MDA (66.26 g, 0.5 mol) was added to the addition funnel (blowcase). The autoclave was sealed, flushed with CO and heated to 140° C. under 100 psig carbon monoxide. The addition funnel containing the MDA was heated to 100° C. Upon reaching 140° C. in the autoclave, the MDA was charged to the autoclave by pressurizing the addition funnel. Immediately upon completing the liquid addition, a sample was removed from the autoclave (time zero) and the pressure was adjusted to 1000 psig CO. The temperature and pressure were maintained using pure carbon monoxide for the duration of the 4 hour reaction. Samples were removed from the autoclave at 15 min, 30 min, 45 min, 60 min, 120 min, 180 min and 240 min. The samples were analyzed by GC and HPLC. Final conversion and selectivity is given in Table 14.
Examples 93-96
[0135] Example 92 was repeated except the acid catalyst and amount were as given in Table 14. 2.5 mmol of acid catalyst was used in each case. The final MDA conversions and selectivities are given in Table 14.
[0000]
TABLE 14
Hydrocarboxylation of MDA in Acetic Acid with a
Homogeneous Strong Acid Catalyst.
Catalyst
MDA
MDA
Ex.
Catalyst
charge (g)
Conversion
Selectivity
92
trifluoromethanesulfonic acid
0.375
99
96
93
tetrafluoroethanesulfonic acid
0.455
96
96
94
bis(trifluoro-
0.70
99
95
methane)sulfonylamide
95
nonafluorobutanesulfonic acid
0.75
99
95
96
sulfuric acid
0.256
81
53
[0136] The following examples illustrate the effect of feed water content, temperature, pressure, and catalyst level on the hydrocarboxylation of trioxane or paraformaldehyde with valeric acid and glycolic acid as solvents/reactants and triflic acid as catalyst.
Example 97
[0137] The continuous hydrocarboxylation was carried out using a reactor system containing Hastelloy 276C autoclave (125 ml nominal volume) and associated feed and product storage equipment. The high pressure autoclave was fitted with a hollow shaft Rushton turbine impeller (for gas introduction and dispersion), baffles, thermowell, gas inlet tube, and sip tube to maintain liquid level at approximately 90 ml and to provide an exit for product effluent. The autoclave was heated electrically by a band heater, with temperature control provided by feedback via a K-type thermocouple in the autoclave thermowell.
[0138] Pure carbon monoxide gas (>99.9%) was fed to the autoclave via a high pressure flow controller. The gas entered the body of the autoclave via groves in the impeller bearings. The off gas flow rate was monitored by a dry bubble-type flow meter. The flow rates of the two liquid feeds were controlled to a precision of 0.001 ml/min with double-barreled 500 ml high-precision syringe pumps connected to stirred feed vessels.
[0139] Reactor effluent passed through heated Hastelloy tubing, an automatic pressure control valve (research control valve), and into a 1.0 L heatable Hastelloy collection vessel. The effluent collection vessel was fitted with a chilled coiled condenser. The gas outlet from the effluent tank was connected to a manual back pressure regulator to maintain vessel pressure at 40-100 psig. Temperatures, pressures, and other relevant system parameters were recorded automatically by a distributed control system.
[0140] Feed 1 (0.4 g/min) and Feed 2 (0.39 g/min), having the composition given in Table 15 were fed to the reactor. Carbon monoxide was fed at a rate of 998 SCCM as noted in Table 16. The reaction was run at a pressure of 1500 psig and a temperature of 170° C. with a residence time of 85 minutes. Table 16 also gives feed molar ratios and the source of formaldehyde. For Example 107 the source was trioxane.
[0141] Samples of the hydrocarboxylation reaction were analyzed by HPLC. Conversion, space-time yield, and selectivity of reacted formaldehyde to end products are summarized in Table 17. Any glycolic acid fed was subtracted out for conversion and yield calculations. Methanol was present as free methanol, methyl glycolate, and methyl valerate, and was converted to free methanol, glycolic acid, and valeric acid by the analytical method.
Examples 98-143
[0142] Example 97 was repeated with the liquid feeds given in Table 15, the carbon monoxide flow rate, source of formaldehyde, feed molar ratios, pressure, temperature, residence time given in Table 16. Conversion, space-time yield, and selectivity of reacted formaldehyde to end products are summarized in Table 17.
[0000]
TABLE 15
Feed 1 and Feed 2: Rates and Compositions
Feed 1
Feed 1, mass %
Feed 2
Feed 2 mass %
Ex #
g/min
F0
A5
G1
water
Triflic
g/min
A5
Triflic
97
0.40
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
98
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
99
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
100
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
101
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
102
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
103
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
104
0.61
21.1
71.9
0.0
3.8
3.2
0.62
100.00
0.00
105
0.61
21.1
71.9
0.0
3.8
3.2
0.62
100.00
0.00
106
0.39
21.1
71.9
0.0
3.8
3.2
0.39
100.00
0.00
107
0.61
21.1
71.9
0.0
3.8
3.2
0.62
100.00
0.00
108
0.39
21.8
74.2
0.0
3.9
0.0
0.39
95.78
4.22
109
0.39
21.8
74.2
0.0
3.9
0.0
0.39
95.78
4.22
110
0.39
21.8
74.2
0.0
3.9
0.0
0.39
95.78
4.22
111
0.39
21.8
74.2
0.0
3.9
0.0
0.39
95.78
4.22
112
0.39
21.8
74.2
0.0
3.9
0.0
0.39
95.78
4.22
113
0.64
26.8
68.4
0.0
4.8
0.0
0.17
85.01
14.99
114
0.64
26.8
68.4
0.0
4.8
0.0
0.17
85.01
14.99
115
0.64
26.8
68.4
0.0
4.8
0.0
0.17
85.01
14.99
116
0.64
26.8
68.4
0.0
4.8
0.0
0.17
85.01
14.99
117
0.64
26.8
68.4
0.0
4.8
0.0
0.17
85.01
14.99
118
0.68
23.7
0.0
60.0
9.9
6.4
0.36
100.00
0.00
119
0.68
23.7
0.0
60.0
9.9
6.4
0.36
100.00
0.00
120
0.68
23.7
0.0
60.0
9.9
6.4
0.36
100.00
0.00
121
0.68
23.7
0.0
60.0
9.9
6.4
0.32
100.00
0.00
122
0.68
23.7
0.0
60.0
9.9
6.4
0.36
100.00
0.00
123
0.68
23.7
0.0
60.0
9.9
6.4
0.36
100.00
0.00
124
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
125
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
126
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
127
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
128
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
129
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
130
0.43
34.0
0.0
51.7
14.3
0.0
0.52
92.93
7.07
131
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
132
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
133
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
134
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
135
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
136
0.65
25.1
0.0
63.6
4.5
6.8
0.38
100.00
0.00
137
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
138
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
139
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
140
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
141
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
142
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39
143
0.47
32.5
0.0
61.7
5.8
0.0
0.54
92.61
7.39%
[0000]
TABLE 16
Overall Feed Molar Ratios and Reaction Conditions
CO
Res
Flow
F0
Feed Molar Ratio
Press
Temp
Time
Ex
SCCM
Type
HFR
A5
G1
water
Triflic
Psig
Celsius
min
97
998.0
Trioxane
1.0
2.0
0.0
0.3
0.030
1500
170
85
98
998.0
Trioxane
1.0
2.0
0.0
0.3
0.030
1001
170
87
99
998.0
Trioxane
1.0
2.0
0.0
0.3
0.030
1498
160
87
100
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1501
150
87
101
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
747
160
87
102
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
997
160
87
103
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1500
170
87
104
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
749
150
55
105
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
750
140
55
106
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
753
170
87
107
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
751
150
55
108
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1501
143
87
109
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1495
160
87
110
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1498
170
87
111
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1500
170
87
112
998.0
Trioxane
1.0
2.0
0.0
0.30
0.030
1499
170
87
113
998.0
Trioxane
1.0
1.0
0.0
0.30
0.030
1498
170
87
114
998.0
Trioxane
1.0
1.0
0.0
0.30
0.030
1003
170
87
115
998.0
Trioxane
1.0
1.0
0.0
0.30
0.030
499
170
87
116
998.0
Trioxane
1.0
1.0
0.0
0.30
0.030
999
160
87
117
998.0
Trioxane
1.0
1.0
0.0
0.30
0.030
506
165
87
118
998.0
PF
1.0
0.7
1.0
0.70
0.054
1497
180
80
119
998.0
PF
1.0
0.7
1.0
0.70
0.054
1503
180
80
120
998.0
PF
1.0
0.7
1.0
0.70
0.054
1497
180
80
121
998.0
PF
1.0
0.7
1.0
0.70
0.054
1498
180
83
122
998.0
PF
1.0
0.7
1.0
0.70
0.054
1504
180
80
123
998.0
PF
1.0
0.7
1.0
0.70
0.054
1504
180
80
124
998.0
PF
1.0
1.0
0.6
0.70
0.054
1492
180
80
125
998.0
PF
1.0
1.0
0.6
0.70
0.054
1003
180
80
126
998.0
PF
1.0
1.0
0.6
0.70
0.054
500
180
80
127
998.0
PF
1.0
1.0
0.6
0.70
0.054
995
170
80
128
998.0
PF
1.0
1.0
0.6
0.70
0.054
502
170
80
129
998.0
PF
1.0
1.0
0.6
0.70
0.054
1000
160
80
130
998.0
PF
1.0
1.0
0.6
0.70
0.054
498
160
80
131
498.0
PF
1.0
0.7
1.0
0.30
0.054
1507
170
80
132
498.0
PF
1.0
0.7
1.0
0.30
0.054
1499
180
80
133
498.0
PF
1.0
0.7
1.0
0.30
0.054
1503
180
80
134
498.0
PF
1.0
0.7
1.0
0.30
0.054
1498
180
80
135
498.0
PF
1.0
0.7
1.0
0.30
0.054
1003
160
80
136
498.0
PF
1.0
0.7
1.0
0.30
0.054
1501
170
80
137
498.0
PF
1.0
1.0
0.8
0.30
0.054
1500
180
76
138
498.0
PF
1.0
1.0
0.8
0.30
0.054
999
180
76
139
498.0
PF
1.0
1.0
0.8
0.30
0.054
500
180
76
140
498.0
PF
1.0
1.0
0.8
0.30
0.054
999
170
76
141
498.0
PF
1.0
1.0
0.8
0.30
0.054
500
170
76
142
498.0
PF
1.0
1.0
0.8
0.30
0.054
1004
160
76
143
498.0
PF
1.0
1.0
0.8
0.30
0.054
500
160
76
[0000]
TABLE 17
Selectivity, Conversion, and Space-Time Yield Results
Space
% F0
Time
Exam-
Conver-
Yield
Selectivity
Molar
ple
sion
gmol/l-hr
G1
A1
DG
MGH
MeOH
97
94.7
1.51
96.42
1.02
1.55
0.00
1.02
98
93.0
1.44
96.71
0.93
1.42
0.00
0.93
99
93.5
1.42
96.41
1.23
1.13
0.00
1.23
100
92.5
0.93
96.22
1.36
1.06
0.00
1.36
101
87.1
1.36
96.17
1.41
0.80
0.43
1.19
102
90.3
1.32
96.92
1.09
0.91
0.00
1.09
103
96.3
1.37
96.90
0.87
1.36
0.00
0.87
104
75.3
1.59
91.30
3.85
0.99
0.00
3.85
105
56.3
1.22
85.32
7.16
0.10
0.50
6.91
106
89.4
1.41
96.55
1.05
1.34
0.00
1.05
107
67.5
1.89
92.15
3.56
0.72
0.00
3.56
108
86.2
1.42
94.31
2.33
0.98
0.12
2.26
109
91.3
1.55
96.12
1.26
1.36
0.00
1.26
110
93.5
1.60
96.32
1.05
1.58
0.00
1.05
111
95.2
1.59
96.10
1.13
1.64
0.00
1.13
112
90.9
1.55
96.71
0.93
1.42
0.00
0.93
113
62.6
1.79
91.65
2.07
4.07
0.19
1.97
114
54.5
1.84
91.64
0.47
7.42
0.00
0.47
115
86.6
2.72
92.16
2.45
2.62
0.56
2.17
116
84.4
2.84
93.10
1.93
3.03
0.00
1.93
117
80.7
2.56
94.18
1.38
2.88
0.37
1.19
118
90.2
2.24
89.72
2.00
5.69
0.73
1.64
119
90.4
2.49
90.79
1.67
5.85
0.00
1.67
120
90.1
2.69
94.24
1.47
2.82
0.00
1.47
121
89.1
2.66
92.90
1.83
3.07
0.31
1.68
122
90.0
2.47
93.07
1.67
3.10
0.72
1.31
123
90.2
2.60
93.35
1.69
2.94
0.66
1.36
124
91.7
2.37
93.41
1.71
3.11
0.11
1.66
125
85.7
2.13
91.14
3.20
2.01
0.90
2.75
126
76.4
1.44
79.78
8.41
2.09
1.83
7.49
127
75.5
2.40
90.60
3.53
2.16
0.36
3.35
128
59.9
1.78
83.27
7.20
1.43
0.85
6.78
129
66.5
0.92
70.09
11.5
2.31
7.69
7.75
130
53.4
0.57
58.03
20.1
0.93
0.86
19.68
131
89.5
2.25
89.86
2.62
3.94
1.49
1.87
132
94.9
2.87
92.05
1.47
4.53
0.79
1.07
133
95.2
2.46
91.01
1.71
4.98
0.92
1.25
134
92.9
2.46
92.89
1.43
4.02
0.37
1.24
135
83.0
1.92
89.48
3.19
3.45
1.21
2.58
136
92.5
2.53
91.90
1.63
4.28
0.72
1.27
137
93.0
2.62
93.77
1.51
2.95
0.53
1.24
138
93.6
2.82
94.21
1.37
2.96
0.17
1.29
139
87.1
2.35
89.56
3.53
2.91
0.81
3.13
140
90.4
2.48
93.64
1.72
2.84
0.00
1.72
141
80.0
2.12
87.08
4.91
2.46
0.88
4.47
142
82.0
2.28
90.50
3.24
2.44
1.13
2.68
143
71.6
2.05
86.67
5.24
2.30
0.48
5.00
[0143] These examples illustrate the effect of feed water content, temperature, pressure, and catalyst level on the hydrocarboxylation of formaldehyde (trioxane) with triflic acid as catalyst, with n-butyric acid and glycolic acid as solvent/reactant.
Examples 144-147
[0144] Example 97 was repeated with only one feed at 0.91 g/min. The feed contained 14.6 wt % paraformaldehyde, 6.2% water, 28.8 wt % butyric acid, 48.2 wt % glycolic acid, and 2.2 wt % triflic acid. The feed molar ratio was paraformaldehyde (1.0), water (0.7), glycolic acid (1.5), and triflic acid (0.03). The hold-up time was 95 minutes. The feed rate of carbon monoxide was 498 SCCM. The operating pressure and temperature, along with conversion, space-time yield, and selectivity of reacted formaldehyde to end products are summarized in Table 18.
[0000]
TABLE 18
Reactor Conditions, Selectivity, Conversion, and Space-Time Yield Results
Space-Time
Temp
Pressure
% F0
Molar Selectivity
Yield
Ex
Celsius
psig
Conversion
G1
A1
MeOH
MGH
DG
gmol/l-hr
144
150
935
40.1
70.1
13.9
13.9
0.0
2.2
1.04
145
170
1199
71.2
83.3
5.6
5.6
1.5
4.1
2.08
146
190
1199
88.3
89.6
1.8
1.8
1.6
5.2
2.91
147
170
1745
77.5
88.0
3.6
3.6
0.8
3.8
2.38
[0145] The following examples illustrate the effect of feed water content, temperature, pressure and catalyst level on the hydrocarboxylation of methylene diacetate with triflic acid as catalyst.
Examples 148-153
[0146] Example 97 was repeated but with MDA as the source of formaldehyde and at the feed rates and compositions noted in Table 19. In these experiments moles of MDA represent the formaldehyde equivalent, while acetic acid equivalents are calculated as the sum of free acetic acid fed and two times the MDA molar flow rate. The feed molar ratios, temperature, pressure, and hold-up time are given in Table 20. Conversion, space-time yield, and selectivity of reacted formaldehyde to end products are summarized in Table 21. All methanol was present as methyl acetate, and was also converted to free methanol and acetic acid by the analytical method.
[0000]
TABLE 19
Feed 1 and 2 Rates and Compositions
Feed 1
Feed 1, mass %
Feed 2
Feed 2 mass %
Ex
g/min
MDA
A2
water
g/min
A2
water
Triflic
148
0.69
100
0
0
0.71
86.7
1.3
0.30
149
0.69
100
0
0
0.79
69.5
29.2
1.30
150
0.69
100
0
0
0.79
69.5
29.2
1.30
151
0.69
100
0
0
0.79
69.5
29.2
1.30
152
1.10
56.4
7.7
35.9
0.32
99
0
1
153
0.03
56.4
7.7
35.0
0.32
96
0
4
[0000]
TABLE 20
Overall Feed Ratios and Reaction Conditions
Feed Molar
Temp
Press
Res Time
Ex
Ratio F0
water
A2
Triflic
Celsius
psig
minutes
148
1.0
1.2
3.8
0.002
190
650
70
149
1.0
1.4
3.0
0.007
200
600
67
150
1.0
1.4
3.0
0.007
190
600
67
151
1.0
1.4
3.0
0.007
180
600
67
152
1.0
1.0
4.5
0.005
190
1300
69
153
1.0
1.0
4.5
0.020
170
1300
73
[0000]
TABLE 21
Selectivity, Conversion, and Space-Time Yield Results
Molar
Space-Time
% HFr
Selectivity
Yield
Ex
Conv
G1
A1
MeOH
MGH
DG
gmol/l-hr
148
70
95.8
1.75
1.75
0.00
0.85
2.20
149
75
90.8
1.7
1.7
0.00
5.8
2.00
150
70
94.2
1.5
1.5
0.00
2.8
2.00
151
50
92.9
1.8
1.7
0.3
3.1
1.20
152
77
93.1
1.7
1.3
0.7
3.1
2.60
153
95
93.3
1.7
1.4
0.7
2.9
2.80
[0147] The following examples illustrate the effect of feed water content, temperature, pressure, and catalyst level on the hydrocarboxylation of paraformaldehyde with sulfuric acid as catalyst.
Examples 154-159
[0148] Example 97 was repeated using only one feed stream with the feed rate and compositions shown in Table 22. The feed mixture was prepared by mixing, water, H 2 SO 4 and HGH in a tank heated to 60° C. Paraformaldehyde was added with stirring until complete dissolution occurred. The feed was kept at 60° C. throughout the reaction period to ensure no solid formaldehyde precipitated. The operating conditions along with reaction pressure, temperature and residence time are summarized in Tables 22 and 23.
[0149] Conversion, space-time yield, and selectivity of reacted formaldehyde to end products are summarized in Table 24. During analysis, glycolic acid oligomers and other forms of glycolic acid were hydrolyzed and converted to free monomeric glycolic acid equivalents. The selectivity of conversion of formaldehyde is reported as free glycolic acid equivalents. Methanol was present as both free methanol and methyl glycolate, and was converted to free methanol and glycolic acid by the analytical method.
[0000]
TABLE 22
Feed 1: Rate and Composition
Ex
g/min
Paraformaldehyde
water
G1
H 2 SO 4
154
0.68
13.8
8.3
70.2
7.7
155
1.01
13.8
11.7
70.0
4.5
156
1.01
13.8
11.6
70.0
4.5
157
1.66
13.0
17.2
66.0
3.8
158
1.02
14.4
4.3
73.2
8.0
159
0.94
29.8
28.6
37.8
3.8
[0000]
TABLE 23
Overall Feed Ratios and Reaction Conditions
Res
Feed Molar Ratio
Temp
Press
Time
Ex
Paraformaldehyde
water
G1
H 2 SO 4
Celsius
psig
minutes
154
1.0
1.0
2.0
0.170
170
1502
180
155
1.0
1.4
2.0
0.100
200
699
120
156
1.0
1.4
2.0
0.100
190
703
120
157
1.0
2.2
2.0
0.089
205
2603
72
158
1.0
0.5
2.0
0.170
190
1901
120
159
1.0
1.6
0.5
0.039
205
2605
120
[0000]
TABLE 24
Selectivity, Conversion, and Space-Time Yield Results
Molar
Space-Time
% F0
Selectivity
Yield
Ex
Conv
G1
A1
DG
MGH
MeOH
gmol/l-hr
154
92
94.06
1.06
3.82
0.00
1.06
1.73
155
87
64.56
10.72
5.56
16.86
2.29
1.05
156
85
70.00
10.80
3.00
10.40
5.70
1.55
157
93
89.22
2.90
4.12
1.72
2.04
3.55
158
97
84.63
1.24
11.97
1.85
0.32
2.51
159
95
89.96
3.04
2.91
2.11
1.98
4.94
|
Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a solid acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the glycolic acid stream is readily removed from the carboxylic acid and the carboxylic acid is recycled.
| 8
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/195,839 filed on Jul. 15, 2002, now U.S. Pat. No. 6,672,090. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to refrigeration systems, compressor control systems and refrigerant regulating valve control systems. More particularly, the invention relates to liquid-side and vapor-side flow control strategies.
BACKGROUND OF THE INVENTION
Traditional refrigeration systems include a compressor, a condenser, an expansion valve, and an evaporator, all interconnected for establishing series fluid communication therebetween. Cooling is accomplished through evaporation of a liquid refrigerant under reduced temperature and pressure. Initially, vapor refrigerant is drawn into the compressor for compression therein. Compression of the vapor refrigerant results in a higher temperature and pressure thereof. From the compressor, the vapor refrigerant flows into the condenser. The condenser acts as a heat exchanger and is in heat exchange relationship with ambient. Heat is transferred from the vapor refrigerant to ambient, whereby the temperature is lowered. In this manner, a state change occurs, whereby the vapor refrigerant condenses to a liquid.
The liquid refrigerant exits an outlet of the condenser and flows into the expansion valve. As the liquid refrigerant flows through the expansion valve, its pressure is reduced prior to entering the evaporator. The evaporator acts as a heat exchanger, similar to the condenser, and is in heat exchange relationship with a cooled area (e.g., an interior of a refrigeration case). Heat is transferred from the cooled area to the liquid refrigerant, thereby increasing the temperature of the liquid refrigerant and resulting in boiling thereof. In this manner, a state change occurs, whereby the liquid refrigerant becomes a vapor. The vapor refrigerant then flows from the evaporators, back to the compressor.
The cooling capacity of the refrigeration system is generally achieved by varying the capacity of the compressor. One method of achieving capacity variation is continuously switching the compressor between on- and off-cycles using a pulse-width modulated signal. In this manner, a desired percent duty cycle for the compressor can be achieved. During the off-cycles, liquid refrigerant experiences “freewheel” flow, whereby the liquid refrigerant migrates into the evaporator. As the refrigerant migrates into the evaporator during the off-cycle, it is boiled therein, and becomes a vapor. This is detrimental to the performance of the refrigeration system in two ways: a significant reduction in the on-cycle evaporator temperature, and a decrease in flow recovery once switched back to the on-cycle.
Further, significant losses occur with traditional refrigeration systems when recently compressed vapor reverse migrates through the compressor, back toward the evaporator, during the off-cycle. These losses are compounded by reverse migration of liquid refrigerant back into the condenser during the off-cycle.
Therefore, it is desirable in the industry to provide a refrigeration system and flow control strategy for alleviating the deficiencies associated with traditional refrigeration systems. In particular, the refrigeration system should prohibit migration of liquid refrigerant into the evaporator during the off-cycle, prohibit reverse migration of vapor refrigerant through the compressor during the off-cycle, and prohibit reverse migration of liquid refrigerant through the condenser during the off-cycle.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a refrigeration system and control method thereof, for alleviating the deficiencies associated with traditional refrigeration systems. More particularly, the refrigeration system includes an evaporator, a variable capacity compressor coupled in fluid communication with the evaporator, a condenser coupled in fluid communication between the compressor and the evaporator, an expansion valve disposed intermediate the condenser and the evaporator, and an isolation valve disposed intermediate the condenser and the expansion valve. The isolation valve is in communication with the compressor for respectively synchronizing opening and closing thereof with on- and off-cycles of the compressor to prohibit migration of liquid refrigerant. In this manner, respective temperatures of the condenser and evaporator are better maintained during the off-cycle.
In accordance with an alternative embodiment, first and second check valves are respectively associated with the compressor and the condenser for prohibiting reverse migration of refrigerant during the off-cycle. In this manner, respective pressures of the refrigerant associated with the condenser and evaporator are decreased over a traditional refrigeration system.
The present invention further provides a method for controlling a refrigeration system having a compressor, a condenser and an evaporator connected in series flow communication. The method includes the steps of varying the compressor between on- and off-cycles to provide a percent duty cycle thereof, and synchronizing opening and closing of an isolation valve, respectively with the on- and off-cycles of the compressor, to prohibit migration of liquid refrigerant into the evaporator during the off-cycle.
In accordance with an alternative embodiment, the method further includes the steps of prohibiting reverse migration of the liquid refrigerant into the condenser, and prohibiting reverse migration of vapor refrigerant through the compressor, during the off-cycle.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a schematic view of a refrigeration system implementing a closed expansion valve in accordance with the principles of the present invention;
FIG. 2 is a graph comparing a condenser temperature for the refrigeration system of FIG. 1 to a condenser temperature for a traditional refrigeration system implementing a continuously open expansion valve;
FIG. 3 is a graph comparing an evaporator temperature for the refrigeration system of FIG. 1 to a condenser temperature for a traditional refrigeration system implementing a continuously open expansion valve;
FIG. 4 is a schematic view of the refrigeration system of FIG. 1 , implementing check valves in accordance with the principles of the present invention;
FIG. 5 is a graph depicting a pressure response for a traditional refrigeration system without the check valves; and
FIG. 6 is a graph depicting a pressure response for the refrigeration system of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With particular reference to FIG. 1 , a refrigeration system 10 is schematically shown. Although the refrigeration system 10 is representative of a heat pump system, it will be appreciated that the implementation thereof, in accordance with the present invention, is for refrigeration. The refrigeration system 10 includes a compressor 12 having an associated pulse-width modulation (PWM) valve 14 , a four-way valve 16 , a condenser 18 , a liquid receiver 20 , an isolation valve 22 , dual evaporators 24 having respective expansion valves 26 , and a controller 28 . The controller 28 is in operable communication with the PWM valve 14 of the compressor 12 , a temperature sensor sensing 30 a temperature of a refrigerated area 32 (e.g. interior of a refrigeration case), and a pressure sensor 34 sensing a pressure of a refrigerant vapor discharged from the dual evaporators 24 , as explained in further detail hereinbelow. Although the present description includes dual evaporators, it is anticipated that the number of evaporators may vary, depending on particular system design requirements. Multiple maintenance valves 35 are also provided to enable maintenance and removal/addition of the various components.
The compressor 12 , and operation thereof, is similar to that disclosed in commonly assigned U.S. Pat. No. 6,047,557, entitled ADAPTIVE CONTROL FOR A REFRIGERATION SYSTEM USING PULSE WIDTH MODULATED DUTY CYCLE SCROLL COMPRESSOR, expressly incorporated herein by reference. A summary of the construction and operation of the compressor 12 is provided herein.
The compressor includes an outer shell and a pair of scroll members supported therein and drivingly connected to a motor-driven crankshaft. One scroll member orbits respective to the other, whereby suction gas is drawn into the shell via a suction inlet. Intermeshing wraps provided on the scroll members define moving fluid pockets that progressively decrease in size and move radially inwardly as a result of the orbiting motion of the scroll member. In this manner, the suction gas entering via the inlet is compressed. The compressed gas is then discharged into a discharge chamber.
In order to switch to an off-cycle (i.e., unload the PWM compressor 12 ), the PWM valve 14 is actuated in response to a signal from the controller 28 , thereby interrupting fluid communication to increase a pressure within the inlet to that of the discharge gas. The biasing force resulting from this discharge pressure causes the non-orbiting scroll member to move axially upwardly away from the orbiting scroll member. This axial movement will result in the creation of a leakage path between the scroll members, thereby substantially eliminating continued compression of the suction gas. When switching to an on-cycle (i.e., resuming compression of the suction gas), the PWM valve 14 is actuated so as to move the non-orbiting scroll member into sealing engagement with the orbiting scroll member. In this manner, the duty cycle of the compressor 12 can be varied between zero (0) and one hundred (100) percent via the PWM valve 14 , as directed by the controller 23 .
The controller 28 monitors the temperature of the refrigerated area 32 and pressure of the vapor refrigerant leaving the evaporators 24 . Based upon these two inputs, and implementing programmed algorithms, the controller 28 determines the percent duty cycle for the PWM compressor 12 and signals the PWM valve 14 for switching between the on- and off-cycles to achieve the desired percent duty cycle.
Operation of the refrigeration system 10 will now be described in detail. Cooling is accomplished through evaporation of a liquid refrigerant under reduced temperature and pressure. Initially, vapor refrigerant is drawn into the compressor 12 for compression therein. Compression of the vapor refrigerant results in a higher temperature and pressure thereof. From the compressor 12 , the vapor refrigerant flows into the condenser 18 . The condenser 18 acts as a heat exchanger and is in heat exchange relationship with ambient. Heat is transferred from the vapor refrigerant to ambient, whereby the temperature is lowered. In this manner, a state change occurs, whereby the vapor refrigerant condenses to a liquid.
The liquid refrigerant exits an outlet of the condenser 18 and is received into the receiver 20 , acting as a liquid refrigerant reservoir. As explained above, the isolation valve 22 is in communication with the controller 28 , whereby it switches between open and closed positions, respectively with the on-, and off-cycles of the PWM compressor 12 . With the isolation valve 22 in the open position, liquid refrigerant flows therethrough and is split, flowing into each of the expansion valves 26 . As the liquid refrigerant flows through the expansion valves 26 , its pressure is reduced prior to entering the evaporators 24 .
The evaporators 24 act as heat exchangers, similar to the condenser 18 , and are in heat exchange relationship with a refrigerated area 32 . Heat is transferred from the refrigerated area 32 , to the liquid refrigerant, thereby increasing the temperature of the liquid refrigerant resulting in boiling thereof. In this manner, a state change occurs, whereby the liquid refrigerant becomes a vapor. The vapor refrigerant then flows from the evaporators 24 , back to the compressor 12 .
The off-cycle occurs when the compressor 12 is essentially turned off by the controller 28 , or is otherwise operating at approximately zero (0) percent duty cycle. Pulse-width modulation results in periodic shifts between the on- and off-cycles to vary the capacity of the PWM compressor 12 . As discussed by way of background, when the refrigeration system 10 switches to the off-cycle from the on-cycle, the recovery of off-cycle flow (“flywheel” flow) is significantly decreased because the refrigerant temperature within the evaporators 24 quickly rises to the surface air temperature of the evaporator exteriors. To improve the recovery of off-cycle flow, the isolation valve 22 is closed during the off-cycle. In this manner, migration of liquid refrigerant into the evaporators 24 is prevented.
With particular reference to FIGS. 2 and 3 , performance of the refrigeration system 10 , implementing the isolation valve 22 , can be compared to a traditional refrigeration system without such a valve, for a fifty (50) percent PWM duty cycle with a thirty (30) second cycle time. More particularly, FIG. 2 provides a comparison of the condenser temperature between the present refrigeration system 10 and a conventional refrigeration system. FIG. 3 provides a comparison of the evaporator temperature between the present refrigeration system 10 and a conventional refrigeration system. The flow recovery penalty of the conventional system can be seen, as the liquid refrigerant migration results in a lower on-cycle evaporator temperature and a correspondingly higher condenser temperature. Thus, more compressor power is required by a conventional refrigeration system to achieve an equivalent overall capacity when compared to the present refrigeration system 10 . The on-cycle condensing temperature of the conventional refrigeration system is higher because the condenser must do more liquid refrigerant sub-cooling to replenish the liquid refrigerant lost during the off-cycle.
The flow recovery penalty for the conventional refrigeration system will increase with longer off-cycles or lower percent PWM duty cycles. This is due to an increased refrigerant migration effect during longer off-cycles.
With particular reference to FIG. 4 , the refrigeration system 10 is shown to further include first and second check valves 40 , 42 , respectively. The first check valve is positioned at an outlet of the PWM compressor 12 , and the second check valve 42 is positioned at an outlet of the condenser 18 . The refrigeration system 10 , as shown in FIG. 4 , operates similarly to that described above with reference to FIG. 1 . However, as the refrigeration system 10 switches from the on-cycle to the off-cycle, significant gas leaking through the compressor outlet side could produce a vapor refrigerant migration effect similar to that described above for the evaporators 24 . To minimize this effect, the first check valve 40 prevents vapor refrigerant migration back through the PWM compressor 12 to the evaporators 24 , and the second check valve 42 assures that the liquid refrigerant in the receiver 20 stays in the receiver 20 .
With particular reference to FIGS. 4 and 5 , a performance comparison can be made between a traditional refrigeration system without check valves 40 , 42 (FIG. 4 ), and the present refrigeration system 10 implementing the check valves 40 , 42 (FIG. 5 ), for a fifty (50) percent PWM duty cycle with an approximately twelve (12) second cycle time. In particular, the refrigeration system pressure responses for the PWM compressor outlet (discharge), condenser outlet, and the PWM compressor inlet (suction) are shown. As can be seen, the pressure at the PWM compressor discharge is significantly increased, and a reduction in the pressure at the PWM compressor suction is also seen during the off-cycle. In this manner, the PWM compressor power penalty is significantly reduced, as compared to the traditional refrigeration system.
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.
|
A cooling system including a pulse-width modulated variable capacity compressor operable between on-cycles and off-cycles, and in electrical communication with the compressor and operable to respectively synchronize opening and closing thereof with on- and off-cycles of the compressor.
| 5
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[0001] This application claims priority from U.S. Provisional Application 60/732,944, for a “Snow Pusher,” filed Nov. 3, 2005 by Michael P. Weagley et al., which is also hereby incorporated by reference in its entirety.
[0002] The following disclosure is directed to aspects of an improved snow or material pusher for use with loaders, backhoes, agricultural and larger home and garden tractors and the like for moving snow or other materials on generally flat areas such as parking lots, driveways, feed lots, runways, and loading areas, for example.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] A “pusher” or “pushing apparatus,” as described for example in U.S. Pat. No. 5,724,755 to Weagley (issued Mar. 3, 1998) or the folding material plow of U.S. Pat. No. 6,112,438, to Weagley et al. (issued Sep. 9, 2000), both hereby incorporated by reference in their entirety, generally include sides extending forward from a mold board or central blade to assure material being pushed (e.g., snow, liquids, debris, sludge, etc.) remains in front of the pusher, and is not directed to one or both sides as with conventional plows.
[0004] The following disclosure is directed to aspects and embodiments of an improved pusher design, including several aspects that can be employed on traditional pusher designs in order to improve the use and efficiency of such pushers. The disclosed aspects and embodiments, alone and in combination, improve the functionality, reliability, ease of use and/or safety of pushers.
[0005] In accordance with an aspect of the embodiments disclosed herein, there is provided a material pushing apparatus, comprising: an upstanding central blade including a first longitudinal edge and a second longitudinal edge along an opposite side of said blade, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of the ends of the central blade; a first cutting edge attached to the central blade along the first longitudinal edge; and a second cutting edge attached to the central blade along the second longitudinal edge.
[0006] In accordance with another aspect disclosed herein, there is provided a reversible coupler for use with a reversible implement, comprising: a first coupler portion suitable for attachment to a vehicle in a first orientation; and a second coupler portion suitable for attachment to the vehicle in a second orientation.
[0007] In accordance with another embodiment, there is disclosed a method of using a reversible pusher, comprising: connecting a vehicle to the pusher in a first orientation having a first cutting edge adjacent a surface upon which the pusher rests; advancing the pusher with the first cutting edge adjacent the surface; disconnecting the pusher from the vehicle; reconnecting the vehicle to the pusher in a second orientation having a second cutting edge adjacent the surface; and advancing the pusher with the second cutting edge adjacent the surface.
[0008] In accordance with a further aspect, there is provided an improved scraping edge for attachment along a longitudinal edge of a moldboard, comprising: a flexible base, removably attached to the moldboard, along a top portion of the base; a rigid cutting edge extending along and removably attached to said flexible base along a bottom portion of the base, wherein said flexible base flexes to allow the cutting edge to bypass immovable objects it contacts; and a tensioner to bias said flexible base into a partially flexed position.
[0009] In accordance with yet another aspect of the invention, there is provided a material pushing apparatus, comprising: an upstanding moldboard including a bottom longitudinal edge, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of said left and right ends of the moldboard; and a scraping edge attached to the moldboard along said bottom longitudinal edge, said scraping edge including, a flexible base, removably attached to the moldboard, along a top portion of the flexible base using at least one hold-down member; a rigid cutting edge extending along and removably attached to said flexible base along a bottom portion of the base, wherein said flexible base flexes to allow the cutting edge to bypass immovable objects it contacts; and a tensioner to bias said flexible base into a partially flexed position.
[0010] In accordance with a further aspect disclosed herein there is provided a material pusher, comprising: an upstanding central blade including a lower longitudinal edge and left and right ends; a vertical side plate extending forward at a right angle from each end of the central blade; and removable wear shoe attached along a bottom edge of each vertical side plate, wherein the removable wear shoe extends from a position adjacent a front edge of the vertical side plate to a position at least 6 inches beyond a rear surface of the moldboard so as to assure that a bottom surface of the wear shoe remains in complete contact with a surface on which the pusher is used.
[0011] In accordance with yet a further aspect of the following disclosure there is provided an extended wear shoe for use on a material pusher, comprising: a web for attachment to a side plate of the pusher; a generally horizontal lower surface for sliding contact with the ground, the lower surface transitioning to front and rear ramped surfaces on either end thereof; and a cap, permanently attached to the web and the upper end of the rear ramped surface thereof.
[0012] Disclosed in accordance with another embodiment is an improved scraping edge for attachment along a longitudinal edge of a pusher moldboard, comprising: a plurality of rigid sections; said sections being attached along the longitudinal edge using fasteners having a low yield strength and hardness such that one or more sections are dislodged from a normal operating position upon contact with an immovable object to thereby prevent damage to the object.
[0013] Also disclosed with respect to yet a further embodiment is a material pushing apparatus, comprising: an upstanding central blade including a lower longitudinal edge and left and right ends; a vertical side plate extending forward at a right angle from each end of the central blade; and a breakaway cutting edge, comprised of a plurality of rigid sections, attached to the central blade along the longitudinal edge, wherein at least one of the sections is dislodged from its normal operating position upon sufficient contact with an immovable object to prevent damage to the object.
[0014] In accordance with a further aspect disclosed herein there is provided a material moving apparatus, comprising: an upstanding moldboard including a bottom longitudinal edge, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of said left and right ends of the moldboard; and a scraping edge attached to the moldboard along said bottom longitudinal edge, said scraping edge including a rigid component and means for assuring that said rigid component yields upon coming in contact with an immovable object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIGS. 1-4 illustrate various features and aspects of a switchblade, reversible coupling pusher in accordance with one embodiment;
[0016] FIGS. 5A-5H illustrate various features and aspects of a switchblade, reversible coupling, pusher in accordance with an alternative embodiment, where FIGS. 5A-5H particularly illustrate steps of using the reversible coupling feature with a skidsteer type vehicle;
[0017] FIGS. 6-7 illustrate various embodiments of a flexible trip edge in accordance with another aspect of the invention;
[0018] FIGS. 8-10 illustrate various embodiments of a breakaway edge in accordance with another aspect of the invention;
[0019] FIGS. 11A and 11B are illustrative side views of alternative embodiments of a snow pushing apparatus employing an extended wear shoe.
DETAILED DESCRIPTION
[0020] As used herein the figures are intended to be exemplary in nature, not limiting, and some or all aspects depicted may not be to scale. As will be further contemplated, various aspects of the disclosed embodiments have particular application to alternative snow removal and material moving technologies and while described in accordance with snow pushers and material pushing apparatus, are not intended to be limited to such embodiments. Accordingly, several of the aspects described herein may find particular use in plow, scraper, drag plow and similar applications in the same manner as described relative to snow or other material pushing embodiments.
[0021] Referring first to FIGS. 1-5H , various aspects of a switchable/reversible orientation or Switchblade™ pusher configuration will be discussed in detail, along with a reversible coupling mechanism associated therewith. FIGS. 1 and 3 , for example, illustrate a switchable orientation material pushing apparatus 110 . The intent of such a device is to provide two different types of scraping edges (e.g., hard and/or flexible) in a single material pusher so that a user can accommodate many different material conditions. In particular, the apparatus is believed to find practical use in its ability to handle new-fallen snow as well as hard-packed and re-frozen snow and ice that accumulate in parking lots and other heavily traveled areas.
[0022] Referring specifically to FIGS. 1-3 , Switchblade pusher 110 includes an upstanding central blade or moldboard 120 having a first longitudinal edge 130 and a second longitudinal edge 140 and left and right ends 150 , 160 , respectively. Also included is a vertical side plate 170 extending forward at a right angle from each of the ends 150 , 160 of the central blade 120 . A first cutting or scraping edge 180 is attached to the central blade or moldboard along the first longitudinal edge 130 , and a second cutting or scraping edge 182 is attached to the central blade along the second longitudinal edge 140 .
[0023] In one embodiment the Switchblade™ two-edged pusher has both a flexible polymer or rubber cutting edge 182 attached along a first longitudinal edge and a more rigid or steel cutting edge 180 along a second longitudinal edge. The flexible edge is perfect for wet, heavy snow conditions or jobsites where there are ground obstacles or imperfections in the surface being cleared. The steel edge 180 is ideal for hard packed snow conditions or jobsites that are flat with no ground obstacles. Alternatively, the steel edge 180 may be used on surfaces where some scraping and even removal of the top surface is desirable, for example, cleaning of animal barns and feedlots. Depending upon the situation the Switchblade pusher provides both types of edges on a single device.
[0024] One embodiment may include at least one flexible or rubber edge removably fastened to the central blade and extending along a longitudinal edge thereof. In FIG. 3 , a flexible rubber edge is generally depicted as 184 where the edge is reversible (by switching top for bottom), and is held to the face of the moldboard 120 using an elongated steel plate(s) as a hold-down member 185 . Moreover, it is contemplated that at least one cutting or scraping is removably fastened to the central blade along a longitudinal edge. As described above, at least one of the cutting edges comprises a rubber or flexible polymer edge 184 extending along and outward from one of the longitudinal edges of the central blade. As illustrated, such an edge is attached to the central blade 120 using a backing plate and bolts, and in some cases, the position of the edge may be adjusted upward or downward using slotted holes in the edge 184 through which the bolts are connected to nuts (not shown) behind the central blade.
[0025] It is further contemplated that one of the cutting edges of the reversible pushing apparatus may be a scraping edge 180 (see also 850 in FIG. 8 ), attached to the moldboard 120 along one longitudinal edge. The scraping edge 180 includes a rigid component and means for assuring that the rigid component yields upon coming in contact with an immovable object. In one embodiment, the scraping edge 180 may be a breakaway edge, wherein at least one of rigid components or sections is dislodged from its normal operating position upon sufficient contact with an immovable object to prevent damage to the object.
[0026] As is also shown in the figures, the pusher apparatus 110 further includes a pair of longitudinal wear shoes 190 along at least two edges of the side plate 170 . The wear shoes may be removable, as depicted, or may be permanently attached or mounted to the side plate. The wear shoes may also be extended as depicted, for example, in FIGS. 11A , B described below. The wear shoes 190 comprise inclined front and rear ramp surfaces 192 for sliding contact on the surface. In one embodiment, the front ends of wear shoes 190 and/or the side plates 170 , in conjunction, provide points or define a surface (along lines A-A′) that enables the apparatus to temporarily stand in an upright position, such as depicted in the embodiment of FIGS. 5B and 5C , in order to permit a vehicle to change the direction in which the apparatus is oriented for pushing—thereby changing from a first operating position where the first scraping edge is adjacent to the surface being cleaned to a second operating position whereby the second scraping edge is adjacent to the surface to be cleaned.
[0027] Considering FIGS. 1-3 and 5 A- 5 H, it will be apparent that the nature of the vehicle (skidsteer, backhoe or loader) is accommodated by one of several reversible couplers 210 , or similar reversible means for attaching the apparatus to a vehicle. The reversible coupler further enables the pushing vehicle 50 to be suitably attached, from either of two opposite directions. Where the vehicle 50 is a skidsteer-type or similar loader vehicle, the reversible coupler 210 includes a quick-coupling connection for both directions.
[0028] The reversible coupler 210 referred to above may be used with a reversible (Switchblade) pusher or with other reversible implements such as those known for use with skidsteer type vehicles. In one embodiment, reversible coupler 210 includes a first coupler assembly 220 , suitable for attachment to a vehicle (loader, skidsteer, etc.) in a first orientation, and a second coupler assembly 230 suitable for attachment to the vehicle in second first orientation. It will be appreciated that the first and second coupler assemblies are essentially mirror image replications of one another and may be contained within a common frame or assembly as depicted in FIGS. 5G and 5H , for example. It is further contemplated that a reversible pusher may have a plurality of non-mirrored couplers on the rear thereof, where one coupler is suitable for receiving a bucket of a loader or backhoe whereas another coupler is suitable for use with a skidsteer-type vehicle, thereby permitting a single pusher to be used with a plurality of vehicle types.
[0029] In the embodiment of FIG. 1 , each coupler assembly 220 , 230 includes two rows of parallel posts mounted on the rear of the pusher, the two rows of parallel posts form a slot 224 for receiving the edge of a bucket on the vehicle (not shown in FIG. 1 ). Referring to FIGS. 5C , F and G, for example, each reversible coupler assembly 210 is mounted on the rear of the pusher 110 and includes a pair of generally parallel side rails 250 , and opposed top members (e.g., downward facing flange) 254 , generally spanning between the side rails and providing a downward-facing pocket 256 on the rear of the pusher, the pocket receiving an upper edge or the like of a skidsteer attachment frame, and an angled foot or lower attachment member 258 on opposite ends, also spanning between the side rails, and suitable for receiving a lower wedge, pin or the like of the skidsteer attachment device. FIGS. 5E and 5F are illustrative examples of one method by which the skidsteer attachment device may be connected; first the attachment device of vehicle 50 is inserted into the pocket 256 and then, upon full connection of the attachment device with the coupler, the locking wedge or pin is inserted. It will be appreciated that various alternative means may be employed to interface with the reversible coupler 210 .
[0030] As an example of one possible configuration for the coupler assembly, FIGS. 5E-5H are referred to in order to illustrate the manner in which a skidsteer (e.g., Bobcat™) or similar vehicle is attached to the coupler. It will be appreciated that the coupler mechanism is duplicated in a mirrored configuration ( FIGS. 5F , G) to provide the reversible coupling referred to. It will also be appreciated that the coupler foot 258 may further include recesses, apertures 260 or similar features for receiving a locking wedge/detent or similar component or mechanism on the vehicle attachment frame—thereby providing positive attachment to the pusher. Alternatively, the pusher may be connected to the vehicle using well know means such as, hooks, clevises, chains and the like as is well known for connecting pushers to vehicles.
[0031] The coupler depicted in FIG. 5C is mounted on the rear of a pusher 110 and employs a common set of side rails such that both of the opposed coupling mechanisms form a single assembly suitable for coupling with a vehicle from opposite or reversible orientations.
[0032] Further referring to FIGS. 5A-5D , the sequence of figures illustrates a method for using a reversible pushing apparatus as described herein. The method includes connecting a vehicle 50 to the pusher in a first orientation ( FIG. 5A ), moving the pusher with a first edge adjacent the ground surface ( FIG. 5A ), standing the pusher on its “nose” (for example along the plane defined by line A-A′) as shown in FIG. 5B , disconnecting the vehicle from the pusher while in the “nose-down” position ( FIG. 5C ) and reconnecting the vehicle to the pusher in a second orientation ( FIG. 5D ), in order to subsequently move the pusher with a second edge adjacent the ground surface.
[0033] In an alternative method it is simply possible to use the vehicle 50 to roll or flip the pusher from one orientation to the other, thereby avoiding the need to temporarily place the pusher into a nose-down position. As will be appreciated, the vehicle should be disengaged from its respective coupler before flipping so as to enable the pusher to switch or reverse to the opposite orientation.
[0034] Referring next to FIGS. 6-7 there is depicted one embodiment of an improved scraping edge for use with the pusher described above, or with other conventional snow pusher designs, including those manufactured by Pro-Tech® and other manufacturers. In general, the improved scraping edge is attached to the central blade or moldboard along a longitudinal edge, and the scraping edge includes a rigid component and means for assuring that said rigid component yields upon coming in contact with an immovable object. In one embodiment, depicted in FIGS. 6-7 , the yielding means may include a flexible base member whereas in an alternative embodiment, depicted in FIGS. 8-10 , the yielding means may include a sacrificial fastener as well as similar components that flex or yield so that the cutting edge does not damage immovable objects it comes in contact with them.
[0035] The improved cutting edge of FIGS. 6-7 is designed for attachment along a longitudinal edge of a pusher moldboard 610 , and in a first embodiment comprises a flexible base 630 , removably attached to the moldboard, along a top portion of the base. In one embodiment, the attachment means includes a metal hold-down member 640 applied on the face of the flexible base 630 , wherein the flexible base is sandwiched between the hold-down member 640 and the moldboard 610 . Removably attached to the flexible base 630 , along a bottom portion thereof is a rigid cutting edge 650 , preferably made of steel and alloys thereof that exhibit high hardness and good wear resistance. The use of the flexible base as the means by which the rigid cutting edge is attached to the moldboard flexible permits flexing of the base and allows the cutting edge to bypass an immovable object that it contacts while the pusher moves and then return to a nominal operating position.
[0036] The flexible scraping edge base 630 may be made of a polymer (e.g., polyurethane), rubber or similar material, and is approximately 1.5 (1.0-2.0) inches thick. Such materials are available from CUE, Inc.. (e.g., Compound No. PO-650) and exhibit approximately the following characteristics: shore durometer (ASTM D2240-64T) of 84A; a compression set of 45% max.; a tensile strength (ASTM D412-61T) of 6000 psi; tensile modulus (ASTM D412-61T) @ 50% elongation of 500 psi; tear strength Trollsera (ASTM D1938)=250, Die C (ASTM D624)=470 and split tear (ASTM D470)=140; compression deflection (ASTM D575-46 Method A)@ 5%=300 psi; and abrasion resistance for Tabor (ASTM D3489-85(90)) of 15% rubber standard or NBS ASTM D1630-83=250.
[0037] In an alternative embodiment, the flexible scraping edge may further include a tensioner 660 to bias the flexible base into a partially flexed position. The use of a biasing means to pre-flex the base 630 assures that the base flexes rearward as the cutting edge 650 comes into contact with an immovable object such as a manhole, water-valve cap, curb, raised concrete or asphalt patch or similar objects. As will be appreciated, alternative biasing means including springs, pre-deformation of the base, tabs or stops along the side plates, etc. may be employed to assure that the polymer base 630 flexes rearward when the edge 650 contacts an immovable object. Absent a tensioner or other means for biasing or preflexing the base, the cutting edge may chatter and skip when contacting or moving over surfaces that are uneven yet generally free of immovable obstructions.
[0038] As further depicted in FIGS. 6 and 7 , the tensioner is removably attached to the moldboard using the same bolts employed for the metal hold-down member 640 . The tensioner includes an arm 662 that extends downward from where it is attached to the moldboard, and at the end of the arm there is a contact point 664 that applies a force or biasing contact to the metal cutting edge 650 , and the flexible base 630 is biased into the partially flexed (rearward) position as shown in the side view of FIG. 6 . It is also intended that the contact force or amount of bias applied to the cutting edge 650 is adjustable by way of bias adjusting bolt 668 , a threaded bolt at the end of the tensioner arm that establishes the contact point with the cutting edge in the embodiment depicted.
[0039] Those knowledgeable in the design of material pushers will appreciate that in an alternative embodiment a material pusher incorporating the improved cutting edge described above, may further include vertically extended or adjustable side plates and/or wear shoes, to provide increased or adjustable clearance between the bottom or the steel cutting edge 650 and the ground surface, thereby providing a region for the installation of the flexible cutting edge-and to provide a sufficient gap below the moldboard in which the edge can flex un an unconstrained fashion.
[0040] Turning next to FIGS. 8-11 , there is disclosed yet another embodiment of the breakaway cutting edge for use on a longitudinal edge of a material pusher or similar plow or pushing apparatus. In the design, the breakaway edge provides a cutting surface adequate to remove hard-packed snow or ice from a surface, yet prevents damage to immovable objects (e.g., manholes, sewer covers, curbs, etc.) that come into contact with the edge. The edge design assures that it becomes detached or “breaks away” from the moldboard upon striking such objects with sufficient force.
[0041] In one embodiment depicted in FIG. 10 , for example, the pusher comprises an upstanding central blade 810 having a lower longitudinal edge 820 and left ( 832 ) and right ends (not shown). A vertical side plate 840 extends forward generally at a right angle from each end of the central blade. The breakaway cutting edge 850 , comprises a plurality of sections 852 , attached to the central blade 810 along the longitudinal edge. At least one of the sections ( 852 ) may be dislodged from its normal operating position in response to the application of sufficient force resulting from contact with an immovable object, thereby preventing damage to the object.
[0042] As depicted in FIGS. 8 and 9 , an applied force Fx 1 is applied to the cutting edge by an immovable object when the pusher is being moved forward along the ground. The force is translated to resulting forces (e.g., Fx 2 ) and relative to opposing force (Fx 3 ) that place the fastener holding the edge 852 to the moldboard 810 , in tension and/or shear. As will be further appreciated, the force applied to the fastener is a function of not only Fx 1 , but also of the relative dimensions of the edge in relation to the moldboard's longitudinal edge, for example, dimensions 811 and 812 . For example, force Fx 1 translates to a significantly “magnified” force Fx 2 as a result of the leverage provided by a wide edge (e.g., dimension 811 ). As depicted, for example, in FIG. 8 , the forces applied to the fasteners holding edge 852 to moldboard 810 are also a function of the angle ( 0 ) of the edge, which results in the addition of a shear stress applied to the fastener as well as a tensile stress.
[0043] Preferably, the longitudinal edge 820 of the central blade 810 is made of a material of sufficient strength, or is reinforced, to resist damage when the breakaway edge strikes an object. Moreover, the cutting edge sections 852 are made from ort formed of steel or similar rigid and/or hardened materials, and are attached to the longitudinal edge using attachment hardware or fasteners (e.g., bolts with nuts as depicted in FIGS. 9 and 10 ) that offer less resistance to the applied stress (shear and/or tensile forces are present) than the cutting edge sections 852 , so as to result in the failure of the hardware/fasteners before damage to the object or the pushing apparatus. More specifically, in one embodiment, the edge sections are mounted to the central blade using bolts having a yield strength of less than about 36,000 psi and a tensile strength of less than about 74,000 psi (equivalent of Grade 2 or less). It will be appreciated that SAE-J429 Grade 1 or 2 (also A307 Grades A, B), may be used to assure that the failure of the bolts, by shear or other means, will occur before damage to the pusher components or the immovable object. It will also be appreciated that depending upon the particular application, the dimensions of the components, and/or sensitivity to damage, alternative fasteners sizes, steel alloys/grades, materials and or hardware components may be employed (e.g., aluminum hardware, shear pins, etc.) Although the angle θ is illustrated at approximately 12-degrees from normal, the embodiment depicted in FIG. 9 is believed best operated over a range of angles from about 5-degrees to about 20-degrees from normal, although use over a range of about 0-degrees to about 30-degrees from normal and higher is possible.
[0044] As generally depicted in FIG. 9 , the present invention further contemplates the use of a safety attachment mechanism 858 connecting the cutting edge sections 852 to the central blade or moldboard 810 so that in the event that the section is completely dislodged (i.e., all fasteners broken), the section will remain attached to the central blade for later reattachment. Such a mechanism may include a loop or hook welded to the back of the cutting edge and attached by chain, cable, clevis or the like to a similar loop or hook on the rear of the central blade.
[0045] Turning now to FIGS. 12A and 12B , there are depicted examples of extended wear shoes for use with a material pusher. The purpose of the extended shoe is to provide a larger surface on which the pusher rides, with the surface extending rearward from the coupling point, thereby making it easier for a vehicle operator to place the pusher in an orientation where the wear shoes are parallel to the ground or surface on which it is being used. Such a feature significantly decreases the likelihood that a pusher will be operated with only the front or rear edge contacting the surface, and thereby quickly wearing out that portion of the shoe. The improved, extended wear shoe 1210 includes a web 1220 for attachment to a side plate of a pusher, and a generally horizontal lower surface 1230 for sliding contact with the ground, the lower surface transitioning to front and rear ramped surfaces on either end thereof, and a cap, 1240 permanently attached to the exposed or extended portion of web 1220 and the upper end of the rear ramped surface. In other words, the cap covers and reinforces the web over at least part of the region 1250 where the shoe extends beyond the rear of the moldboard 810 , and as depicted in FIG. 12A that portion beyond the rear edge of the side plate.
[0046] As seen in FIG. 12A-12B , the wear shoe extends a distance (region 1250 ) of at least about 10 to about 25% of the side plate length beyond the rear of the moldboard 810 , and as mentioned above beyond the coupling contact point between the vehicle and the pusher. Thus, the pusher has a removable wear shoe 1210 attached along a bottom edge of each vertical side plate, where the removable wear shoe extends from a position generally adjacent a front edge of the vertical side plate to a position well beyond the rear of the moldboard to assure that the majority of a bottom surface of the wear shoe remains in contact with the ground surface on which the pusher is used.
[0047] The present disclosure contemplates additional improvements to the wear shoe, that include at least a wear shoe lower horizontal surface 1230 made from a steel (e.g., HARDOX 500 (Super Duty) from SSAB Oxelsund AB with 0.26% Cr, 0.49% Si, 1.15% Mn, 0.010% P, 0.002 S, 0.070 Cr, 0.05 Ni, 0.009 Mo and 0.002 B) having a hardness of at least about 300 and more preferably about Brinnell. In such embodiments, a heavy duty shoe having improved wear performance may be fabricated using HARDOX 400 (Heavy Duty) or HARDOX 500 (Super Duty). HARDOX wear plate has a hardness of at least 300 and approximately 400 HB. It combines high wear resistance with toughness and good weldability. HARDOX is manufactured by SSAB Oxelosund AB. Use of the 400 and 500 grades is believed adequate, having a Brinnell hardness from about 300-550, to significantly reduce the wear of the shoes during normal pusher use. It will be further understood that the thickness of the lower horizontal surface of the various wear shoes may also be modified to provide longer shoe life.
[0048] It will be appreciated that various of the afore-described improvements and modifications may be applied or adapted to operate in conjunction with or on other types of pushers and material moving or scraping apparatus, including but not limited to, fold-out pushers and other types of snow plows and blades. It will be further appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
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Disclosed herein are various aspects of an improved snow or material pushers for use with loaders, backhoes, agricultural and larger home and garden tractors and the like for moving snow or other materials on generally flat areas such as parking lots, driveways, feed lots, runways, and loading areas. The improvements include, among others, a reversible design, extended side plates and/or wear shoes as well as improved scraping edge configurations so as to provide added functionality and versatility to pushers. As described the various features may be employed alone or in combination to provide the capability for snow and ice removal while minimizing the potential for damage to surfaces and objects thereon.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation-In-Part of U.S. patent application Ser. No. 12/654,637 of the same inventor, filed on Dec. 28, 2009 entitled “super-junction trenched MOSFET with Resurf Step Oxide and the method to make the same”.
FIELD OF THE INVENTION
[0002] This invention relates generally to the cell structure, device configuration and fabrication process of power semiconductor devices. More particularly, this invention relates to a novel and improved cell structure, device configuration and improved fabrication process of a super-junction MOSFET (Metal Oxide Semiconductor Field Effect Transistor).
BACKGROUND OF THE INVENTION
[0003] Compared to the conventional trench MOSFETs, super-junction trench MOSFETs are more attractive due to higher breakdown voltage and lower specific Rds (drain-source resistance). As is known to all, a super-junction trench MOSFET is implemented by a p type column structure and an n type column structure arranged in parallel and connecting to each other onto a heavily doped substrate, however, the manufacturing yield is not stable because it is very sensitive to the fabrication processes and conditions such as: the p type column structure and the n type column structure dopant re-diffusion issue induced by subsequent thermal processes; trapped charges within the column structure, etc. . . . . All that will cause a hazardous condition of charges imbalance to the super-junction trench MOSFET. More specifically, these undesired influences become more pronounced with a narrower column structure width for a lower bias voltage ranging under 200V.
[0004] Prior art (paper “Industrialization of Resurf Stepped Oxide Technology for Power Transistor”, by M. A. Gajda, etc., and paper “Tunable Oxide-Bypassed Trench Gate MOSFET Breaking the Ideal Super-junction MOSFET Performance Line at Equal Column Width”, by Xin Yang, etc.) disclosed device structure in order to resolve the limitation caused by the conventional super-junction trench MOSFET discussed above, as shown in FIG. 1A and FIG. 1B . Except some different terminologies (the device structure in FIG. 1A named with RSO: Resurf Stepped Oxide and the device structure in FIG. 1B named with TOB: Tuable Oxide-Bypassed), both the device structures in FIG. 1A and FIG. 1B are basically the same which can achieve a lower specific Rds and a higher breakdown voltage than a conventional super-junction trench MOSFET because each the epitaxial layer formed in FIG. 1A and FIG. 1B has a higher doping concentration than the conventional super-junction trench MOSFET.
[0005] Refer to FIG. 1A and FIG. 1B again, both the device structures have a deep trench with a thick oxide layer along trench sidewalk and bottom into a drift region. Only difference is that, the device structure in FIG. 1A has a single epitaxial layer (N Epi, as illustrated in FIG. 1A ) while the device structure in FIG. 1B has double epitaxial layers (Epi 1 and Epi 2 , as illustrated in FIG. 1B , the Epi 1 supported on a heavily doped substrate has a lower doping concentration than the Epi 2 near a channel region). Due to the p type column structure and the n type column structure interdiffusion, both the device structures in FIG. 1A and FIG. 1B do not have charges imbalance issue, resolving the technical limitation caused by the conventional super-junction trench MOSFET, however, the benefit of both the device structures in FIG. 1A and FIG. 1B over the conventional super-junction trench MOSFET only pronounces at the bias voltage ranging under 200V, which means that, the conventional super-junction trench MOSFET has a lower Rds when the bias voltage is beyond 200V.
[0006] U.S. Pat. No. 7,601,597 disclosed a method to avoid the aforementioned p type column structure and the n type structure dopant re-diffusion issue, for example in an N-channel trench MOSFET as shown in FIG. 1C , by setting up the p type column formation process at a last step after all diffusion processes such as: sacrificial oxidation after trench etch, gate oxidation, P body region formation and n+ source region formation, etc. . . . have been finished.
[0007] However, the disclosed method of this prior art is not effective because that, firstly, the p type column structure is formed by growing an additional p type epitaxial layer in deep trenches etched in an n type epitaxial layer; secondly, an additional CMP (Chemical Mechanical Polishing) is required for surface planarization after the p type epitaxial layer is grown; thirdly, double trench etches are necessary (one for shallow trenches for trenched gates formation and another for the deep trenches for the p type column structure formation), all the increased cost is not conductive to mass production. Moreover, other factors such as: the charges imbalance caused by the trapped charges within the column structure is still not resolved.
[0008] Therefore, there is still a need in the art of the semiconductor power device, particularly for super-junction trench MOSFET design and fabrication, to provide a novel cell structure, device configuration that would resolve these difficulties and design limitations.
SUMMARY OF THE INVENTION
[0009] The present invention provides a super-junction trench MOSFET with resurf stepped oxides (RSO) having additional freedom for better performance optimization and manufacturing capability by tuning a thick oxide thickness to minimize influence of the charges imbalance, trapped charges, etc. Therefore, the present invention only requires one kind gate trenches and a single epitaxial layer to achieve a better cost effective than the prior arts. Moreover, the present invention also provides split gate electrodes in a super-junction trench MOSFET.
[0010] In one aspect, the present invention features a super-junction trench MOSFET comprising: a substrate of a first conductivity type; an epitaxial layer of the first conductivity type onto the substrate, wherein the epitaxial layer has a lower doping concentration than the substrate; a plurality of gate trenches starting from a top surface of the epitaxial layer and extending downward into the epitaxial layer, each of the gate trenches being padded by a first insulation layer along lower portions of trench sidewalls and padded by a second insulation layer along upper portions of the trench sidewalls, wherein the first insulation layer has a greater thickness than the second insulation layer; a source electrode is formed within each of the gate trenched and surrounded by the first insulation layer in the lower portion of each of the gate trenches; the second insulation layer is formed at least along upper sidewalls of the source electrode; a pair of split gate electrodes are disposed in the upper portion of each of the gate trenches, wherein each of the split gate electrodes is formed between the source electrode and adjacent trench sidewall of the gate trenches and surrounded with the second insulation layer; a plurality of mesas between two adjacent gate trenches; a plurality of first doped column regions of a second conductivity type formed in the mesas; a plurality of second doped column regions of the first conductivity type formed in the mesas and adjacent to sidewalls of the gate trenches, located in parallel and surrounding the first doped column regions; the split gate electrodes having bottoms interfaced with the first insulation layer and having sidewalls interfaced with the second insulation layer; the source electrode is disposed between the split gate electrodes and extending deeper than the split gate electrodes in each of the gate trenches, the source electrode having a lower portion which is underneath the split gate electrodes and interfaced with the first insulation layer, and having an upper portion adjacent to the split gate electrodes and interfaced with the second insulation layer; a plurality of body regions of the second conductivity type formed in the mesas and adjacent to the split gate electrodes, covering a top surface of the first doped column regions and the second doped column regions between two adjacent gate trenches; a plurality of source regions of the first conductivity type formed in the mesas in an active area and having a higher doping concentration than the epitaxial layer, the source regions located formed on top surface of the body regions and adjacent to the split gate electrodes in an active area; and a plurality of trenched source-body contacts each filled with a contact metal plug, penetrating through the source regions and extending into the body regions.
[0011] Preferred embodiments include one or more of the following features: the gate trenches each having a trench bottom above the substrate, and underneath a bottom surface of each of the first doped column regions and the second doped column regions; the gate trenches each having a trench bottom further extending into the substrate, and the first doped column regions and the second doped column regions each having a bottom surface reaching the substrate; the source electrode in each of the gate trenches being connected to a source metal through a trenched source electrode contact filled with the contact metal plug; the gate trenches further extending to a gate contact trench which has a same filling-in structure as the gate trenches in the active area comprising the source electrodes and the split gate electrodes padded with the first and second insulation layers, wherein the split gate electrodes in the gate contact trench are connected to a gate metal through a trenched gate contact filled with the contact metal plug; the contact metal plug is a tungsten metal layer padded by a barrier metal layer of Ti/TiN or Co/TiN or Ta/TiN; the contact metal plug is Al alloys or Cu padded by a barrier metal layer of Ti/TiN or Co/TiN or Ta/TiN, wherein the contact metal plug is also extended onto a contact interlayer to respectively formed as a source metal or a gate metal; the present invention further comprising a plurality of body contact doped regions of the second conductivity type within the body regions and surrounding at least bottoms of the trenched source-body contacts underneath the source regions, wherein the body contact doped regions have a higher doping concentration than the body regions; the present invention further comprising a termination area which comprises a guard ring connected to the source regions and multiple floating guard rings having floating voltage, wherein the guard ring and the multiple floating guard rings have junction depths greater than the body regions; the present invention further comprising a termination area which comprises multiple floating trenched gates having floating voltage and being spaced apart by mesas comprising the body regions and the first and second doped column regions same as in the active area, wherein the floating trenched gates each having a filling-in electrode structure the same as in the gate trenches in the active area; the present invention further comprising a termination area which comprises multiple floating trenched gates having floating voltage and being spaced apart by mesas without comprising the body regions but having the first and second doped column regions, wherein the floating trenched gates each having a filling-in electrode structure the same as in the gate trenches; the source regions have a uniform doping concentration and junction depth between sidewalls of the trenched source-body contacts to adjacent channel regions near the gate trenches; the source regions have a higher doping concentration and a greater junction depth along sidewalls of the trenched source-body contacts than along adjacent channel regions near the gate trenches, and the source regions have a Gaussian-distribution doping profile from the sidewalls of the trenched source-body contacts to the adjacent channel regions; the first conductivity type is N type and the second conductivity type is P type; the first conductivity type is P type and the second conductivity type is N type.
[0012] The invention also features a method for manufacturing a super-junction trench MOSFET comprising the steps of: (a) growing an epitaxial layer of a first conductivity type upon a substrate of the first conductivity type, wherein the epitaxial layer has a lower doping concentration than the substrate; (b) forming a block layer onto a top surface of the epitaxial layer; (c) applying a trench mask on the block layer; (d) forming a plurality of gate trenches, and mesas between adjacent gate trenches in the epitaxial layer by etching through open regions in the block layer; (e) keeping the block layer substantially covering the mesas after formation of the trenches to block sequential angle ion implantation into top surfaces of the mesas; (f) carrying out an angle Ion Implantation of a second conductivity type dopant into the mesas through the open regions in the block layer to form a plurality of first doped column regions in the mesas and adjacent to sidewalls of the gate trenches; (g) carrying out an angle Ion Implantation of the first conductivity type dopant into the mesas through the open regions in the block layer to form a plurality of second doped column regions adjacent to the sidewalls of the gate trenches and in parallel with the first doped column regions; (h) diffusing both the first conductivity type dopant and the second conductivity type dopant into the mesas simultaneously to respectively form the first doped column regions between two adjacent gate trenches, and the second doped column regions adjacent to the sidewalls of the gate trenches an in parallel surrounding the first doped column regions; (i) forming a thick oxide layer along inner surfaces of the gate trenches by thermal oxide growth or oxide deposition; (j) depositing a first doped poly-silicon layer filling the gate trenches to serve as source electrodes; (k) etching back the source electrodes from the top surface of the epitaxial layer (l) etching back the thick oxide layer from an upper portion of the gate trenches; (m) forming a thin oxide layer covering a top surface of the thick oxide layer, along upper inner surfaces of the gate trenches and along upper sidewalls of the source electrodes above the top surface of the thick oxide layer; (n) depositing a second doped poly-silicon layer filling the upper portion of the gate trenches surrounded with the thin oxide layer to serve as split gate electrodes; (o) etching back the split gate electrodes by CMP (Chemical Mechanical Polishing) or plasma etch; (p) carrying out a body implantation of the second conductivity type dopant and a step of body diffusion to form body regions; (q) applying a source mask onto the top surface of the epitaxial layer; and (r) carrying out a source implantation of the first conductivity type dopant and a source diffusion to form source regions.
[0013] These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment, which is illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:
[0015] FIG. 1A is a cross-sectional view of a trench MOSFET of a prior art.
[0016] FIG. 1B is a cross-sectional view of a trench MOSFET of another prior art.
[0017] FIG. 1C is a cross-sectional view of a super-junction trench MOSFET of another prior art.
[0018] FIG. 2A is a cross-sectional view of a preferred embodiment according to the present invention.
[0019] FIG. 2B is another cross-sectional view of the preferred embodiment according to the present invention.
[0020] FIG. 3 is a cross-sectional view of another preferred embodiment according to the present invention.
[0021] FIG. 4 is a cross-sectional view of another preferred embodiment according to the present invention.
[0022] FIG. 5A is a cross-sectional view of another preferred embodiment according to the present invention.
[0023] FIG. 5B is a cross-sectional view of another preferred embodiment according to the present invention.
[0024] FIG. 5C is a cross-sectional view of another preferred embodiment according to the present invention.
[0025] FIG. 6 is a cross-sectional view of another preferred embodiment according to the present invention.
[0026] FIGS. 7A-7H are a serial of side cross-sectional views for showing the processing steps for fabricating the super-junction trench MOSFET as shown in FIG. 4 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] In the following Detailed Description, reference is made to the accompanying drawings, which forms a part thereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top”, “bottom”, “front”, “back”, etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purpose of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be make without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise.
[0028] Please refer to FIG. 2A for a preferred embodiment of this invention where an N-channel super-junction trench MOSFET 200 is formed in an N− epitaxial layer 201 onto an N+ substrate 202 coated with a back metal of Ti/Ni/Ag on a rear side as a drain metal 220 . A plurality of gate trenches 203 are formed starting from a top surface of the N− epitaxial layer 201 and extending downward into the N− epitaxial layer 201 , wherein trench bottoms of the gate trenches 203 are above a common interface between the N+ substrate 202 and the N− epitaxial layer 201 . Each of the gate trenches 203 is lined by a first insulation layer 204 along a lower inner surface and lined by a second insulation layer 205 along an upper inner surface, wherein the first insulation layer 204 has a greater thickness than the second insulation layer 205 . Split gate electrodes 206 (G, as illustrated) are formed along the upper inner surface of each of the gate trenches 203 , having sidewalls surrounded by the second insulation layer 205 and having a bottom interfaced with the first insulation layer 204 . A source electrode 207 (S, as illustrated) is formed between the split gate electrodes 206 within each of the gate trenches 203 , the source electrode 207 has a lower portion underneath the split gate electrodes 206 surrounded by the first insulation layer 204 , the source electrode 207 has an upper portion adjacent to the split gate electrodes 206 and surrounded by the second insulation layer 205 , wherein the split gate electrodes 206 each is formed in the middle between the source electrode 207 and the upper inner surface of each of the gate trenches 203 . Both the split gate electrode 206 and the source electrode 207 can be implemented by using doped poly-silicon layer. A plurality of mesas is located between two adjacent gate trenches 203 . A P type first doped column region 208 is formed in each of the mesas and a pair of N type second doped column regions 209 are formed adjacent to sidewalls of the gate trenches 203 and surround in parallel the P type second doped column region 208 . Onto a top surface of the N type second doped column regions 209 and the P type first doped column regions 208 in the mesas, p body regions 210 are formed covered by n+ source regions 211 in an active area and adjacent to the split gate electrodes 206 . A plurality of trenched source-body contacts 212 each filled with a contact metal plug 213 are penetrating through a contact interlayer 214 , the n+ source regions 211 in the active area and extending into the p body region 210 , wherein the contact metal plug 213 is Al alloys or Cu padded by a barrier metal layer of Ti/TiN or Co/TiN or Ta/TiN, the contact metal plug 213 is also extended onto the contact interlayer 214 to be formed as a source metal 215 which is connected to the n+ source regions 211 and the p body region 210 . The n+ source regions 211 have a uniform doping concentration and junction depth between sidewalls of the trenched source-body contacts 212 to adjacent channel regions near the gate trenches 203 . A p+ body contact doped region 216 is formed surrounding at least bottom of each of the trenched source-body contacts 212 to reduce the contact resistance between the p body regions 210 and the contact metal plug 213 .
[0029] FIG. 2B shows a cross-sectional view of another trench MOSFET 200 ′ according to the present invention. The trench MOSFET 200 ′ has a similar structure as the trench MOSFET 200 in the active area, except that, the source electrode 207 ′ in each of the gate trenches 203 ′ is connected to the source metal 215 ′ through a trenched source electrode contact ( 222 - 1 or 222 - 2 ) filled with the contact metal plug ( 223 - 1 or 223 - 2 , which is the same as the contact metal plug 213 in FIG. 2A ). Moreover, the gate trenches 203 ′ further extend to a gate contact trench 203 ″ which has a same filling-in electrode structure as in the gate trenches 203 ′. The split gate electrode 206 ′ within the gate contact trench 203 ″ are connected to a gate metal 219 via a trenched gate contact ( 220 - 1 or 220 - 2 ) filled with the contact metal plug ( 221 - 1 or 221 - 2 , which is the same as the contact metal plug 213 ) for gate connection. In this embodiment, the contact metal plugs 223 - 1 and 223 - 2 are extending over the contact interlayer 214 ′ to be formed as the source metal 215 ′, the contact metal plugs 221 - 1 and 221 - 2 are extending over the contact interlayer 214 ′ to be formed as the gate metal 219 .
[0030] FIG. 3 is a cross-sectional view of another preferred embodiment according to the present invention. N-channel trench MOSFET 300 in FIG. 3 is similar to the trench MOSFET 200 ′ in FIG. 2B except that, in FIG. 3 , the gate trenches 303 and the gate contact trench 303 ′ are starting from the top surface of the epitaxial layer and further extending into the N+ substrate 302 . Besides, bottoms of the N type second doped column regions 309 and the P type first doped column regions 308 are reaching the common interface between the epitaxial layer and the N+ substrate 302 .
[0031] FIG. 4 is a cross-sectional view of another preferred embodiment according to the present invention. N-channel trench MOSFET 400 in FIG. 4 is similar to the trench MOSFET 300 in FIG. 3 except that, in FIG. 4 , the contact metal plugs ( 423 - 1 and 423 - 2 ) filled in the trenched source electrode contacts ( 422 - 1 and 422 - 2 ), the contact metal plug 413 filled in the trenched source-body contact 412 , and the contact metal plugs ( 421 - 1 and 421 - 2 ) filled in the trenched gate contacts ( 420 - 1 and 420 - 2 ) are a tungsten metal layer padded by a barrier metal layer of Ti/TiN or Co/TiN or Ta/TiN. Moreover, the source metal 415 and the gate metal 419 extending over the contact interlayer 414 are padded by a resistance-reduction layer Ti or Ti/TiN (not shown) underneath to reduce the contact resistance between the source metal 415 and the contact metal plugs ( 413 , 423 - 1 and 423 - 2 ), between the gate metal 419 and the contact metal plugs ( 421 - 1 and 421 - 2 ).
[0032] FIG. 5A shows a cross-sectional view of another preferred embodiment according to the present invention which has a similar structure in the active area with the trench MOSFET 300 in FIG. 3 , N-channel trench MOSFET 500 in FIG. 5A further comprises multiple floating trenched gates 521 being spaced apart by a plurality of mesas without having body regions between them in a termination area 520 , wherein the multiple floating trenched gates 521 having a floating voltage have a same filling-in electrode structure as in the gate trenches 503 in the active area.
[0033] FIG. 5B shows a cross-sectional view of another preferred embodiment according to the present invention which has a similar structure in the active area with the trench MOSFET 300 in FIG. 3 , N-channel trench MOSFET 500 ′ in FIG. 5B further comprises multiple floating trenched gates 531 being spaced apart by a plurality of mesas having the p body regions 510 in a termination area 530 , wherein the trenched floating gates 531 having a floating voltage have a same filling-in electrode structure as in the gate trenches 513 in the active area.
[0034] FIG. 5C shows a cross-sectional view of another preferred embodiment according to the present invention which has a similar structure in the active area as the trench MOSFET 300 in FIG. 3 , N-channel trench MOSFET 500 ″ in FIG. 5C further comprises a guard ring 539 (GR, as illustrated in FIG. 5C ) connected with the n+ source regions 511 , and multiple floating guard rings 549 having floating voltage in a termination area 540 , wherein the guard ring 539 and the multiple floating guard rings 549 have junction depths greater than the p body regions 550 .
[0035] FIG. 6 shows a cross-sectional view of another preferred embodiment according to the present invention which has a similar structure to the trench MOSFET 400 in FIG. 4 except that, in N-channel trench MOSFET 600 of FIG. 6 , the n+ source regions 611 have a higher doping concentration and a greater junction depth along sidewalls of the trenched source-body contacts 612 than along adjacent channel regions near the gate trenches 603 , and the n+ source regions 611 have a Gaussian-distribution doping profile from the sidewalls of the trenched source-body contacts 612 to the adjacent channel regions near the gate trenches 603 .
[0036] FIGS. 7A˜7H are a serial of exemplary steps that are performed to form the inventive super-junction trench MOSFET 417 in FIG. 4 . FIG. 7A , an N epitaxial layer 401 is formed onto an N+ substrate 402 , wherein the N+ substrate 402 has a higher doping concentration than the N epitaxial layer 401 , and share a common interface with the N epitaxial layer 401 . Next, a block layer 430 , which can be implemented by using an oxide layer, is formed covering a top surface of the N epitaxial layer 401 . Then, after a trench mask (not shown) is applied onto the block layer 430 , a plurality of gate trenches 403 and at least a gate contact trench 403 ′ are etched through open regions 438 of the block layer 430 formed by dry etch, the N epitaxial layer 401 , the interface and further extending into the N+ substrate 402 by successively dry silicon etch. Meanwhile, a plurality of mesas are formed between two adjacent gate trenches 403 and the gate contact trench 403 ′.
[0037] In FIG. 7B , a sacrificial oxide (not shown) is first grown and then removed to eliminate the plasma damage introduced during opening the gate trenches 403 and the gate contact trench 403 ′. The block layer 430 is still substantially remained on the mesas after the sacrificial oxide removed to block sequential angle ion implantations into top surfaces of the mesas. After that, a screen oxide 440 is grown along inner surfaces of the gate trenches 403 and the gate contact trench 403 ′. Then, an angle Ion Implantation of Boron dopant through the open regions 438 is carried out to form a plurality of P type first doped column regions 408 with column shape in the mesas and adjacent to sidewalls of the gate trenches 403 and the gate contact trench 403 ′.
[0038] In FIG. 7C , another angle Ion Implantation of Arsenic or Phosphorus dopant is carried out to form a plurality of N type second doped column regions 409 with column shape adjacent to the sidewalls of the gate trenches and the gate contact trench, formed in parallel and surrounding the P type first doped column regions 408 .
[0039] In FIG. 7D , a diffusion step for both the P type first doped column regions 408 and the N type second doped column regions 409 is carried out, therefore, the P type first doped column regions 408 and N type second doped column 409 are formed simultaneously. The P type first doped column regions 408 are diffused to be in parallel surrounded with the N type second doped column regions 409 . In another preferred embodiment, an additional diffusion is carried out prior to carrying out the angle ion implantation of Arsenic and Phosphorus dopant.
[0040] In FIG. 7E , the block layer and the screen oxide are removed away. A thick oxide layer 404 ′ is formed lining the inner surfaces of the gate trenches and the gate contact trench by thermal oxide growth or thick oxide deposition. Then, a first doped poly-silicon layer is deposited onto the thick oxide layer 404 ′ to fill the gate trenches and the gate contact trench and is then etched back from the top surface of the N epitaxial layer 401 to serve as a source electrode 410 . Next, the thick oxide layer 404 ′ is etched away from an upper portion of the gate trenches and the gate contact trench.
[0041] In FIG. 7F , a thin oxide layer as a gate oxide 405 is grown or deposited along upper inner surfaces of the gate trenches 403 and the gate contact trench 403 ′, and along upper sidewalls of the source electrode 410 above the top surface of the thick oxide layer. Then, a second doped poly-silicon layer is deposited filling in between the source electrodes 410 and the adjacent sidewalls of the gate trenches and the gate contact trench, and then is etched back by CMP or plasma etch to serve as split gate electrodes 411 . Therefore, the split gate electrodes 411 have trench bottoms interfaced with the first insulation layer 404 and have sidewalls interfaced with the second insulation layer 405 . Then, a step of Ion Implantation with P type dopant is carried out to form p body regions 420 between two adjacent of the gate trenches and the gate contact trench, and covering the N type second doped column regions 409 and the P type first doped column regions 408 . Then, after applying a source mask (not shown), a step of Ion Implantation with N type dopant is carried out to form n+ source regions 414 near a top surface of the P body regions 420 in an active area.
[0042] In FIG. 7G , another insulation layer is deposited onto the whole top surface of the device structure to serve as a contact interlayer 418 . Then, after applying a contact mask (not shown) onto the contact interlayer 418 , a plurality of contact holes are formed by successively dry oxide etch and dry silicon etch. After penetrating through the contact interlayer 418 , the contact holes 415 are further penetrating through the n+ source region 414 and extending into the p body region 420 in the active area, the contact holes 415 ′ are extending into the source electrodes 410 , and the contact holes 415 ″ are extending into the split gate electrodes 408 in the gate contact trench. Next, a BF2 Ion Implantation is performed to form a plurality of p+ body contact doped regions 417 within the p body regions 713 and surrounding at least bottoms of the contact holes 415 .
[0043] In FIG. 7H , a barrier metal layer Ti/TiN or Co/TiN or Ta/TiN is deposited on sidewalls and bottoms of all the contact holes followed by a step of RTA process for silicide formation. Then, a tungsten material layer is deposited onto the barrier metal layer, wherein the tungsten material layer and the barrier metal layer are then etched back to form: contact metal plugs ( 423 - 1 and 423 - 2 ) for trenched source electrode contacts ( 422 - 1 and 422 - 2 ); contact metal plugs 413 for trenched source-body contacts 412 ; and contact metal plugs ( 421 - 1 and 421 - 2 ) for trenched gate contacts ( 420 - 1 and 420 - 2 ). Then, a metal layer of Al alloys or Cu padded by a resistance-reduction layer Ti or Ti/TiN underneath is deposited onto the contact inter-layer 418 and followed by a metal etching process by employing a metal mask (not shown) to form a source metal 415 and a gate metal 419 .
[0044] Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alternations and modifications will no doubt become apparent to those skilled in the art reading the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alternations and modifications as fall within the true spirit and scope of the invention.
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A super-junction trench MOSFET with Resurf Stepped Oxide and split gate electrodes is disclosed. The inventive structure can apply additional freedom for better optimization of device performance and manufacturing capability by tuning thick oxide thickness to minimize influence of charge imbalance, trapped charges, etc. Furthermore, the fabrication method can be implemented more reliably with lower cost.
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FIELD OF THE INVENTION
This invention relates to a brake mechanism for releasable braking, e.g., of a cable drum used in heavy equipment.
BACKGROUND OF THE INVENTION
Heavy equipment used for lifting, hoisting, scraping, etc. has moving components such as scoops and blades. These components may be raised or lowered by winding in or playing out cables from a winch, turning gears and the like. Such movements are ongoing continuously in the use of the heavy equipment and will involve something like raising a scoop with product, stopping the scoop at a desired travel level, moving the scoop to a deposit site, lowering the scoop and dumping the product. The cable is repetitively wound onto and off of the winch's drum and/or gears are repeatedly engaged and turned, and at the end of each movement, a brake is applied to stop and then hold the position.
Brakes that are used on such winches or other apparatus are typically complex and expensive, they rapidly wear and are difficult and expensive to repair or replace, and they are noisy.
It is an objective of the present invention to provide an improved braking system for such winches or similar apparatus.
BRIEF DESCRIPTION OF THE INVENTION
In a preferred embodiment of the present invention, a rotor is mounted to the drive shaft of a hoist drum. A pair of brake shoes are movably mounted to each side of the rotor and are slidable into and out of engagement with the rotor. A plunger mechanism or actuator is independently mounted behind each brake shoe. A piston within the mechanism is spring biased to urge the brake shoe into engagement with the rotor and hydraulic pressure urges the piston away from the brake shoe allowing the brake shoe to disengage from the rotor.
A single hydraulic fluid source can service a plurality of the plunger mechanisms each having a remote controlled pump. In its simplest form, the brake is released by operation of the hydraulic fluid pump and sequencing the brake release and engagement of the electric winch motor produces acceptably smooth transition between them. However, a switching system may be used to enhance the cooperative action between brake release/engagement and the power applied to the hoist drum.
Whereas the brake shoes are independently mounted, they can be serviced with little problem or down time. The brake mechanism of the invention outlasts known braking mechanism and is far simpler in its operation and less noisy. The benefits will be more fully understood by reference to the following detailed description and the drawings referred to therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of an example of an article of heavy equipment incorporating the brake system of the present invention;
FIG. 2 is a view of the brake system of the present invention applied to a drive system of a cable drum of the article of FIG. 1;
FIG. 3 is an exploded view of the brake system of the present invention including brake shoe actuators as one of the components;
FIG. 4 is an exploded view of the actuators of the brake system of FIG. 3;
FIG. 5 is a cross section of the brake system for illustrating its operation; and
FIGS. 6 a and 6 b are electrical schematics illustrating a suggested type of control over the braking operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Refer now to FIG. 1 of the drawings which illustrates by example a portion of an article of heavy equipment 10 that incorporates the brake system of the present invention. The equipment contemplated herein is of the type that has functional components that are moved by drive systems. In the example of FIG. 1, the equipment 10 has grappling forks 11 that are elevated and lowered by the operation of a cable drum assembly 12 . When the cable 14 is deployed off the drum assembly 12 , the forks 11 of equipment 10 are lowered. When the cable 14 is wound onto the drum assembly 12 , the forks 11 of the equipment 10 are elevated. The proper operation of the drum assembly 12 requires that the drive system 16 of the drum assembly 12 is lockable into a desired position. The drive system 16 , for example, is energized to rotate in one direction to wrap cable 14 onto the drum assembly 12 to elevate the forks 11 of the equipment 10 . When the forks 11 have been elevated to the desired elevation, the drive system 16 is de-energized and a braking system is required to maintain the drive system in a set position and, therefore, maintain the forks 11 of the equipment 10 at the desired elevation. In this embodiment the brake system of the present invention is applied to the drive system 16 of the cable drum assembly 12 .
The drive system 16 for the cable drum assembly 12 includes an electric motor 20 as illustrated in more detail in FIG. 2 . The motor 20 is rotatably driven in one direction to deploy cable 14 off the drum 12 and is rotated in the opposite direction to reel cable 14 onto the drum assembly 12 . Basically, the brake system of the present invention has a rotor 22 fixedly mounted to the end of a splined drive shaft (hidden from view but note center line 23 representing the axis of the drive shaft) of the motor 20 . Brake shoes 24 positioned at opposite sides of the rotor are urged into frictional contact with the rotor 22 by spring biased pistons contained within actuators 32 . The brake shoes 24 have pads 25 (FIG. 3) that engage the rotor 22 . The braking pressure of the actuators 32 is released by hydraulic action acting on the pistons of the actuators 32 . The brake system of the present invention thus has the braking force applied by the spring biased pistons of the actuators 32 , and the braking force is released by the hydraulic pressure acting in opposition to the spring pressure applied to the pistons which is discussed in detail with reference to FIGS. 3 and 4.
Refer now to FIG. 3 of the drawings which illustrates an exploded view of the braking system of the present invention. An end bracket 40 is mountable to the housing of the motor 20 by conventional fasteners. The bracket 40 has spacer blocks 42 mounted on two of its peripheral edges. The bracket 40 has a center bore 44 which receives a bearing 46 that supports the end of the motor shaft. The bearing is retained in the bore 44 by a bearing keeper 48 . The bracket 40 thus rotatably supports the end of the shaft of the motor 20 . A support bracket 52 is fixedly attached to the blocks 42 of the bracket 40 . The bracket 52 is a shaped member that is arranged to support a spacer block 54 and actuators 32 . The spacer block 54 and actuators 32 are fixedly mounted to the bracket 52 by conventional fasteners 53 . An actuator 32 is mounted on each side of the spacer block 54 .
The actuators 32 have extending ears 36 that have bores 37 that mate with bores 57 of the spacer block 54 to facilitate mounting the actuators 32 to the spacer block 54 and to the bracket 52 . The mating bores of the bracket 52 are out of view in FIG. 3 . Conventional fasteners fasten the actuators 32 to the spacer block 54 and bracket 52 . As shown in FIG. 4, one of the actuators has an extending ear 36 with only one bore 37 . Additional fasteners, such as pins 38 that fit into bores 39 are provided to further secure the actuator 32 against movement relative to the spacer block 54 .
An adapter 60 which has internal splines 62 is mounted on the end of the splined motor shaft and retained by fastener 63 . A rotor 22 is fixedly mounted to the adapter 60 by fasteners 23 and thus the rotor will rotate with the shaft of the motor 20 . Brake pads 24 , one on each side of the rotor 22 , are slidably mounted on pins 64 that are insertable into the spacer block 54 . The pins 64 are secured by a clip 65 .
The actuators 32 are further illustrated in FIG. 4 and as previously mentioned, one actuator is mounted on one side of the spacer block 54 and the other actuator is mounted on the other side of the spacer block 54 . Each actuator 32 has a piston 66 (plunger) that is received in a bore 68 of the actuator 32 and end 70 of the piston 66 is slidably movable in a bore 74 of the actuators 32 . The bore 68 and the piston 66 define an expandable chamber within the actuator 32 . A spring 30 is in abutment with the piston 66 and is retained in the bore 68 by an end cap 78 . In this embodiment the spring 30 is a plurality of bevel washers. However it will be appreciated that other types of springs may be employed such as a coil spring. The end cap 78 is threadably installed in the bore 68 and is also utilized to adjust the compression of the spring 30 . Bolt or screw 69 screwed into the cap 78 serves as a piston stop. Each bore 68 has a port 67 for connecting a hydraulic line 81 (FIG. 1 ).
The brake assembly of the present invention is mounted on the drive motor as illustrated in FIG. 2. A hydraulic pump and reservoir 80 (FIG. 1) provides the flow of hydraulic fluid under pressure via hydraulic line 81 to each actuator 32 to move the pistons 66 against the springs 30 . The braking action is caused by the springs 30 of each actuator 32 moving the ends 70 of the pistons 66 against the brake shoes 24 which forces the brake shoes 24 into frictional contact with the rotor 22 . Release of the brake is accomplished by applying hydraulic pressure against the piston 66 of each actuator 32 to compress the springs 30 and thus to relieve the force urging shoes 24 against the rotor 22 . (See FIG. 5)
In operation (FIGS. 1 and 5 ), when the drive system 16 is idle, (no hydraulic pressure applied), the brake shoes 24 are forced against the rotor 22 by action of the springs 30 acting against plungers 66 (indicated by double arrows 71 ) to thus lock the motor 20 in a fixed position. Controls 84 are provided to coordinate the release of the brake when the drive motor 20 is energized and to apply the brake when the drive motor 20 is de-energized. When energy is applied to the drive motor 20 to rotate the drum assembly 12 in either direction, the controls 84 will control a hydraulic valve 82 to supply hydraulic pressure through lines 81 to the pistons 66 of the actuators 32 . The hydraulic pressure applied to the pistons 66 will force the pistons 66 against the springs 30 to L compress the springs 30 , thus releasing the pressure applied by piston 66 against the brake shoes 24 and thus release of the brake shoes applied against the rotor 22 . This permits free rotation of the rotor and the drum assembly 12 . When the drive motor 20 is de-energized, the control 84 will control the valve 82 to release the hydraulic pressure against the piston 66 and the springs 30 will force the pistons 66 and thus the brake shoes 24 against the rotor 22 to again create a braking action to maintain the drive in a set position.
One of the features of the present invention is the ready replacement of the brake shoes 24 when it is required to replace them due to wear or other causes. When it is necessary to replace the brake shoes 24 , the drum assembly 12 is rotated by operation of the motor 20 to a static state. That is, where a braking force is not required. Hydraulic pressure is applied to the pistons 66 of the actuators 32 to release the brake shoes from the rotor 22 . The brake shoe retaining pins 64 are simply removed to disassemble the brake shoes from the spacer block and the old brake shoes are simply removed from between the rotor and the actuator 32 . Replacement shoes 24 are simply inserted in position to receive the pins 64 slidably connecting the shoes to the spacer block 54 and the brake assembly is ready for operation.
Whereas separate switches may be manually engaged/disengaged to initiate motor and brake actuation, a single switch may be employed to initiate a desired sequence of these actions. FIGS. 6 a and 6 b illustrate circuitry that may be employed to this end. Those skilled in the art will, without further disclosure or discussion, understand the application of such circuitry and/or related circuitry to satisfy this objective.
Those skilled in the art will recognize that modifications and variations may be made without departing from the true spirit and scope of the invention. For example, whereas the disclosure uses as an example the raising and lowering of grappling forks by a winch, even in the machine that is illustrated, the invention can be applied to the opening and closing action of the tusks (overlying the forks), it can be applied to tilting of the forks and even to the steering of the machine. The latter applications likely are operated by intermeshing gears rather than winches. The invention is therefore not to be limited to the embodiments described and illustrated but is to be determined from the appended claims.
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A braking system for a drive mechanism for a hoist and similar operating motors used on heavy equipment. A rotor is fixedly mounted to a shaft of the drive mechanism. Actuators having brake shoes are mounted strategic to the rotor. The brake shoes are forced against the rotor by springs of the actuators to produce a braking action. The shoes are released from the rotor by hydraulic pressure compressing the springs of the actuators. Controls are provided to coordinate the action of the actuators with the function of the drive mechanism.
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This application is a continuation-in-part of application Ser. No. 10/007,489, Filed Dec. 5, 2001, now U.S. Pat. No. 7,125,982 and related divisional application Ser. No. 10/679,305 (pending) and continued-in-part herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention described herein provides a non-toxic method of increasing the natural mutation rate in bacteria. The method relies on the use of a modified salt namely thio-phosphate as a source of phosphate in culture media. Thio-phosphate is taken up by cells and ultimately incorporated into DNA such that it inhibits DNA editing and other cellular repair pathways. The mutation rate can be increased several hundred fold. Thio-phosphate substituted media is useful for generating variant strains, plasmids, or phage DNAs with high efficiency after several cycles of growth and amplification in thio-phosphate modified media.
2. Description of Related Disclosures
Traditional methods of mutagenesis involve chemical mutagens such as ethylmethane sulfonate (EMS) and others that are toxic carcinogens (Lawrence (1991) Methods and Enzymology 194:273-281). Such mutagens can be used to generate base substitutions, deletions, frame shift mutations, and additions. Another method of mutagenesis involves the use of transposable elements that when activated transpose and insert in or near a gene resulting in altered gene expression (Spradling (1999) Genetics 153:135; Rothstein (1991) Methods and Enzymology 194:281-301; Spradling and Rubin (1982) Science 218:341-347).
The mutagenesis of specific gene segments is an important tool in the field of biotechnology. Early work involved the chemical mutagenesis of recombinant DNA plasmids in vitro followed by transformation of cells in vivo (Sikorski and Boeke (1991) 194:302-318). More recent methods involve the use of mutator strains for growing plasmids (Greener et al (1996) Methods Mol. Biol. 57: 375-385) or in vitro mutagenesis of plasmids via error prone PCR (Cline et al (1996) NAR 24:3546-3551; Leung et al (1989) Technique 1; 11-15). A drawback of PCR mutagenesis has been a nonuniform mutational spectrum and low yields resulting from the required reaction conditions. Efforts to overcome such biases have been devised through the use of new enzymes (Cline and Hogrefe (2000) Strategies 13:157-161). Expanding the power of gene specific mutagenesis is the technique of PCR shuffling that is used to generate new combinations of mutant alleles for specific genes (Stemmer (1994) PNAS 91:10747-10751). The method involves the introduction of new mutations which serve as a source of genetic diversity for subsequent recombination events.
The present invention describes methods for the use of thio-phosphate as a mutagenic agent. Previous work has shown that phosphorothioate substituted DNA is resistant to DNA editing by DNA polymerase in vitro (Burgers and Eckstein (1979) J. Biol. Chem. 254:68896893). More recently, it has been shown (Frayne U.S. Ser. No. 10/007,489, Filed Dec. 5, 2001) that thio-phosphate can replace normal phosphate in cells and result in the incorporation of thio-phosphate nucleotides into DNA creating phosphorothioate linkages. Thus thio-phosphate can be used in culture media to increase the natural mutation rate by inhibiting DNA repair mechanisms in vivo. Cells can be grown for extended periods in media with thio-phosphate fully substituting for phosphate. The 100-200 fold increase in mutation rate is greater than the 20 fold increase expected from in vitro studies (Goodman et al (1993) Crit. Rev. Biochem. Mol. Biol. 28:83-126). Multiple repair pathways are presumably blocked by phosphorothioate linkages in bacteria. In contrast to bacteria yeast appear to show little or no increase in mutation rate when thio-phosphate is used as a source of phosphate in culture media. The enhanced mutation rate provides a novel means to mutate cells or recombinant DNA sequences in vivo and also allows for a wide range of mutations.
SUMMARY OF THE INVENTION
The present method of growing bacterial cells in 100% thio-phosphate substituted media provides an inexpensive and non-toxic method to increase the natural mutation rate for bacteria in general. This feature of the modified media should facilitate the generation of strains with new properties or useful DNA sequence variants for markers. It also has the advantage that cells can be grown under selective conditions when screening for phenotypes with an increased or decreased quantitative index.
The use of thio-phosphate for enhanced mutagenesis creates a mutator environment that can be used to efficiently mutate recombinant plasmid or phage DNA after two or more cycles of growth and amplification. The use of phage as a vector has the advantage that the DNA does not need to be purified after each cycle and instead only the phage supernatant needs to be retained for next round of amplification. The method described prevents mutations from accumulating in host cells and only viable phage DNAs are selected for. A significant mutation rate can be achieved without the use of error prone PCR suitable for directed evolution or protein structure and function studies. The use of recombinant DNA phage also provides a means to mutate entire collections of cloned DNA or cDNA libraries.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Depicts pathway for uptake of thio-phosphate by cells and incorporation into nucleic acids. The result is the creation of phosphorothioate linkages which are resistant to DNA editing and other repair mechanisms.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Thio-phosphate is readily metabolized by a variety of cell types (Frayne Ser. No. 10/007,489, Filed Dec. 5, 2001; Frayne U.S. division of Ser. No. 10/007,489, Filed Dec. 5, 2003). The modified phosphate is incorporated into dNTP and NTP precursor pools and ultimately nucleic acids. In doing so it impairs DNA repair mechanisms particularly in bacteria and can thus be used in general as a mutagenic agent for prokaryotic micro-organisms. Micro-organisms are used extensively in the production of various entities such as enzymes, antibiotics, chemicals, etc. Cultivation and maintenance of industrial strains is crucial to the outcome of such fermentation reactions. In addition, new strains are often developed to increase productivity.
Many commercially successful micro-organisms have been selected for years to achieve their desired properties. Generally such strains are subject to chemical or UV mutagenesis. These methods have limitations in the types of mutations generated. Critical for the maintenance of bacterial strains is a knowledge of the strain's mutation rate. The greater the mutation rate the greater the tendency for that strain to form substrains. Many factors can influence mutation rates and even different genes can have different mutation rates. The greater the scale of production the greater the need to minimize mutation rates as mutants will accumulate during scale up (Frayne (2002) American Biotechnology 21:68). It is useful to gather information about gene specific mutation rates to assess the overall mutation rate for a given strain. To reduce the number of bacteria required for screening one can examine the accumulation of mutations by serial dilution. A single colony will contain ˜1 million cells indicating a 20 fold amplification. If this colony is picked, grown, and replated the number of mutations will increase 400 fold (20×20) above the mutation rate per generation. By growing cells in mutator medium or agar plates containing thio-phoshate, the number of mutations can be increased further approximately ˜200 fold during each growth stage. This enables the screening of mutations after two to three cycles of plating and amplification. Different strains can then be compared to assess their relative mutation rates or to validate mutation rates.
Multiple rounds of amplification in mutator media and plating of individual colonies can be used to accelerate the accumulation of mutations. Only small volumes of media are required for growth or plating. The process also helps to select for viable cells. For example, it is possible to select for increased growth of an organism in the continued presence of mutator media. This may facilitate selection by allowing for the gradual accumulation of mutations under selective conditions in which growing cells are favored. Multiple rounds of growth and selection allow for a stepwise increase in growth rate. This type of approach is suitable for continuous traits and not discontinuous traits where a period in the absence of selection is required for the expression of the gene or genes leading to the new phenotype. However, cells can be plated on normal media which allows for the expression of genes in the absence of selection, after which it becomes possible to select for discontinuous traits.
For mutagenesis with thio-phosphate requiring extended culture periods it is best to prepare phosphate depleted nutrient broths to achieve high levels of thio-phosphate incorporation. This can be done by magnesium sulfate precipitation of phosphate in the presence of ammonium hydroxide (Rubin (1973) J. Biol. Chem. 248:3860). Bacterial cells respond well to high levels of thio-phosphate producing high yields of recombinant DNA molecules when grown in such medias.
Thio-phosphate mutator media can also be used for generating random mutations in specific genes. The method has the advantage that it can be done inexpensively in vivo for a large number of recombinant DNA molecules. There are two approaches that can be used depending on the particular situation. For recombinant DNA plasmids cells can be grown in mutator media designed for that organism (Frayne U.S. Ser. No. 10/007,489, Filed Dec. 5, 2001). After several cycles of plating and amplification in mutator media plasmids can be isolated and used to transform cells. Additional cycles of plating and amplification can be used if necessary. The limitation of this method comes from the viability of the host cell which will also accumulate mutations that are deleterious at a higher rate owing to its much larger complexity. That is why it is necessary to isolate the plasmid and start again with new host cells to increase the mutation rate to the desired level.
To mutate specific genes it is best to use phage DNA as the phage can easily be separated from host cells and used in successive rounds of mutagenesis. In contrast to plasmids the limitation of phage mutagenesis arises not from host cell viability but rather from the size of the virus used. The procedure selects for viable phage and the smaller the phage the better as fewer genes will be required for successful infections. Recombinant M13 phage works quite well and it is possible to obtain a high rate of mutagenesis of the recombinant DNA insert targeted (˜one to two mutations per insert). It is also conceivable that libraries of recombinant phage can be collectively mutated. Mutagenesis of this type is useful for directed evolution.
EXPERIMENTAL
Example I
Random Mutagenesis of M13 Recombinant DNA Phage
Recombinant M13 phage DNA can be mutated at a high rate by amplification in thio-phosphate containing media. The propagation of M13 phage in thio-phosphate containing media first requires the cultivation of the appropriate host strain such as JM109 which requires minimal media to select for the F′ pillus. Minimal plates are prepared as follows: bactoagar, 10.5 g/L; K 2 HPO 4 3H 2 O, 4.5 g/L; KH 2 PO 4 , 4.5 g/L; (NH 4 ) 2 SO 4 , 1 g/L; sodium citrate 2H 2 O, 0.5 g/L; Adjust pH to 7.4 and autoclave. Then add the following: MgSO 4 7H 2 O, 0.2 g/L (sterilized separately as a conc. solution); (thiamine HCL, 5 ug/L; glucose, 4 g/L sterilized separately by filtration). Glucose can also be sterilized by autoclaving separately. FeCl 2 (500 ug/L) can also be added as needed. Thio-phosphate containing media is prepared similarly as minimal media except that the inorganic phosphates are replaced with thio-phosphate (Na 3 SPO 3 XH 2 O) 10-15 g/L and KCL (1.5 g/L). Thio-phosphate contains variable amounts of water (10-15 per molecule) not included in molecular weight calculations. It is almost 50% water by weight. Note pH control is important in maximizing thio-phosphate stability. To ensure adequate growth, use a high density innoculum. The preferred pH is neutral or slightly basic. Alternatively as described above phosphate depleted nutrient broth can be used and thio-phosphate added at ˜1 g per liter.
Several media are required for the production of infectious phage particles: LBM medium (bacto tryptone, 10 g/L; bacto yeast extract, 5 g/L; NaCl, 5 g/L; 2 g/L MgCl 2 H 2 O; 10 mM Tris/HCL pH 7.5. LBM agar plates (add 15 gm Bacto-agar to 1 liter of LBM medium and autoclave); soft agar (add 7 gm of bacto-agar to 1 liter of LBM medium. Store at 4° C. and heat to 45° C. before use.).
Phage are generated by transforming JM109 cells with the replicative form of M13 DNA or double-stranded DNA using the calcium chloride (Dagert and Ehrlich (1979) Gene 6:23) or DMSO/PEG (Chung et al (1989) PNAS 86:2172-2176). The transformed cells produce infectious particles when grown in nutrient broth. To 0.3 ml of competent cells add 5 ng of DNA and let the mixture sit on ice for 40 min. Then heat shock the cells at 42° C. for 2 min. and add the following: 0.2 ml of fresh JM109 cells and 3 ml of top agar at 45° C. Mix and plate directly onto LBM plates. Let the plates solidify and then incubate at 37° C. until plaques are seen (overnight). The plaques appear as turbid clearings on the bacterial lawn. A plaque can then be picked with a sterile toothpick and used to innoculate 2 ml of LBM broth and grown with shaking overnight. The cells are spun out and the supernatant is saved as phage stock at 4° C. The supernatant (20 ul) can be run directly on a gel to test for the presence of DNA. The titer of the stock should be checked to ensure high yields. The titer should be at least 1×10 10 /ml.
To prepare phosphorothioate phage substituted DNA, JM109 cells are incubated overnight in LB broth. The starter culture can be used directly. Generally 500 ml of thio-phosphate containing media are innoculated with 10-25 ml of overnight culture (high density) and grown for ˜1.5 hrs to an OD 600=0.3 (early log phase). At this point infect cells with phage stock at a moi of 1 pfu per 10 bacterial cells. This corresponds to approximately 500 ul of phage stock. The cells are then incubated at 37° C. with shaking for 3 hr. and not more.
Mutation rates are assayed easily by scoring plaques for beta-galactosidase activity using a standard blue/white colormetric assay involving IPTG (isopropyl-beta-D-thiogalactopyranoside) and X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactoside). To assay for activity, an aliqout of phage is mixed with 0.2 ml of JM109 cells, 10 ul IPTG (100 mM), and 50 ul Xgal (2%). Three mls of top agar are added and the entire mixture with phage is plated on 1X YT (bacto tryptone, 8 g/L; bacto yeast extract, 10 g/L; NaCl, 10 g/L. Adjust pH to 7.5) plates and incubated overnight. Wildtype plaques are blue and those with mutations are colorless. After one round of phage amplification in thio-phosphate media, the bacterial cells are spun out and the supernatant assayed for colorless plaques. The phage containing supernatant is plated such that ˜1000 plaques are formed per plate; the titer is similar for wildtype and phosphorothioate phage after one round of amplification. For phosphorothioate DNA phage approximately two mutant plaques are observed per plate or 1/400. Wildtype phage grown for the same period do not generate mutants (less than 1/4000). The percentage of mutants observed can be increased by another round of amplification in thio-phosphate media. The phosphorothioate DNA phage from the first amplification are used to innoculate the second round of amplification. The phage supernatant from the second round of amplification has a lower titre (˜five fold) than that of similarly prepared wildtype phage. Nevertheless, the mutation rate is quite high, on the order of 1/6 compared with wildtype phage grown under similar conditions (<1/1000). The fold enhancement (˜>200) of the mutation rate is much greater than expected from in vitro studies (20 fold) indicating that multiple repair mechanisms are inhibited (Kunkel et al (1981) PNAS 78:6734-6738). Note that the assay used measures enzyme activity and does not include silent or missense mutations that do not disrupt enzyme activity. Therefore, the real mutation rate is actually higher and more in the range of one to two mutants per phage DNA insert.
Example II
Method of Enhancing the Natural Rate of Mutagenesis
S. cerevisiae grown in thio-phosphate media (phosphate free minimal media, EMM supplemented with SP (Bio101) and 1 g/L thio-phosphate) also exhibit an enhanced mutation rate though much less so than observed in bacteria. To test the mutation rate yeast cells were selected for canavanine resistance (60 ug/ml) in minimal media minus arginine (Hoffman (1985) J. Biol. Chem. 260:11831-11836) and 100% thio-phosphate. An overnight culture of the haploid yeast strain ATTC 32119 was used to innoculate thio-phosphate media at a one to twenty volume ratio. The number of viable yeast cells after one to two days of growth at 30° C. is reduced compared to wildtype when tested on normal phosphate containing plates. The yeast are pelleted by centrifugation and washed with water and resuspended in water at the original volume. The resuspended cells are then spread (˜50 ul 100 mm plate) on canavanine containing plates and Can R colonies observed after two days as distinct colonies. The average increase in mutation rate for yeast grown in thio-phosphate media compared to normal media is approximately 10 fold (range observed 3.9-18.5).
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Methods are presented for enhancing the natural mutation rate of micro-organisms, particularly bacteria via a modified phosphate. The novel metabolite inhibits DNA repair mechanisms in vivo resulting in a 100-200 hundred fold increase in the mutation rate of bacteria. The method yields viable cells and allows for the continuous selection of incremental traits.
The modified phosphate can also be used to randomly mutate specific genes. In particular, high rates of random mutagenesis can be readily achieved in vivo using recombinant DNA phage. The phage are amplified in mutator media containing the modified phosphate. The resultant phage can be further mutated by another round of infection and growth in mutator media. After two such rounds of amplification significant mutation rates are achieved such that each phage insert bears a novel mutation. The mutator media can also be used to mutagenize recombinant DNA plasmids in virtually any bacterial host.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The invention described herein is related in subject matter to the inventions disclosed in R.L. Zinser copending applications for "Method For Improving The Speech Quality In Multi-Pulse Excited Linear Predictive Coding", Ser. No. 07/353,856 filed May 18, 1989, "Hybrid Switched Multi-Pulse/Stochastic Speech Coding Technique", Ser. No. 07/353,855 filed May 18, 1989, and "Method For Improving Speech Quality In Code Excited Linear Predictive (CELP) Coding", Ser. No. 07/427,074 filed Oct. 26, 1989 now U.S. Pat. No. 4,980,916, all of which are assigned to the assignee of this application. The disclosures of the aforesaid copending applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention generally relates to digital voice transmission systems and, more particularly, to a low-overhead method for protecting multi-pulse speech coders against the effects of severe random or fading pattern bit errors, common to digital mobile radio channels.
Code Excited Linear Prediction (CELP) and Multi-pulse Linear Predictive Coding (MPLPC) are two of the most promising techniques for low rate speech coding. While CELP holds the most promise for high quality, its computational requirements can be excessive for some systems. MPLPC can be implemented with much less complexity, but it is generally considered to provide lower quality than CELP.
Multi-pulse coding was first described by B.S. Atal and J. R. Remde in "A New Model of LPC Excitation for Producing Natural Sounding Speech at Low Bit Rates", Proc. of 1982 IEEE Int. Conf. on Acoustics, Speech, and Signal Processing, May 1982, pp. 614-617. It was described as an improvement on the rather synthetic quality of the speech produced by the standard U.S. Department of Defense (DOD) LPC-10 vocoder. The basic method is to employ the Linear Predictive Coding (LPC) speech synthesis filter of the standard vocoder, but to excite the filter with multiple pulses per pitch period, instead of with the single pulse as in the DOD standard system.
In low-rate speech coding systems, bit errors can introduce appreciable artifacts into the decoded speech. For example, at a bit error rate (BER) of 5%, an unprotected 4800 bit/second multi-pulse speech coder would exhibit poor intelligibility in the output speech. Since a random bit error rate of 5% is not uncommon in digital mobile radio, protection of the coder against random pattern bit error artifacts is very important.
In addition to random pattern errors, mobile radio exhibits a more severe error effect known as fading errors. Fading errors occur when a moving vehicle encounters an area where the direct and reflected signals combine destructively and produce little or no signal level at the receiver. Such fades occur in a quasi-periodic fashion, where the length of and time between fades, depend on the vehicle speed, transmission rate, and carrier frequency. During a fade, all information is lost, and a random stream of bits is sent to the speech decoder. Thus the speech coder operates with occasional bursts of an effective 50% BER. These bursts produce severe short-term "whoop" and "splat" artifacts in the speech output. Conventional error protection schemes (such as convolutional coding) cannot protect against most fades.
Convolutional coding with Viterbi decoding is well known for its superior performance with random bit error patterns. See A. J. Viterbi and J. K. Omura, Principles of Digital Communication and Coding, McGraw-Hill, 1979, pages 301-315. Experimental results show that a rate 1/2 coder (a coder that produces one additional check bit for each input bit, i.e., "1 bit in, 2 bits out") will perform quite well in 5% randomly distributed errors, producing a post-decoder output BER of 0.2-0.4%. Unfortunately, in an 800 MHz, 44 kbit/second fading channel model, it provides no improvement. Thus, a rate 1/2 convolutional coder/Viterbi decoder is useful for randomly distributed errors only.
If a means for detecting fade occurrence is provided, then some degree of fade protection can be achieved by taking "evasive action" within the speech decoding algorithm. Systems to accomplish such result take advantage of the quasi-stationary and periodic nature of the speech signal by interpolating or holding over spectral and gain information from a previous usable or "good" frame. Such system is described by N. DalDegan, F. Perosino and F. Rusina in "Communications by Vocoder on a Mobile Satellite Fading Channel", Proceedings of the IEEE International Conference on Communications -- 1985. (ICC-85), pp. 771-775, June 1985, for a standard LPC-10 vocoder.
The DalDegan et al. method detects fades using what they characterize as a "Signal Quality Detector" and by estimating the LPC distance between contiguous frames. Presumably, if the quality detector indicates an unusable, or "bad" frame, and the LPC distance measure between the "bad" frame and the previous "good" frame is above a threshold, the algorithm will reuse the previous frame's LPC coefficients; or, if a faded frame occurs between two good frames, it will interpolate the LPC values from the surrounding frames for the bad frame. While the DalDegan et al. algorithm also interpolates (or holds over) values for the pitch period and the gain, it cannot provide any protection during periods of random pattern errors. It requires a signal level measurement to indicate the presence of a deep fade.
What is needed is a scheme that protects against the effects of both random and fading pattern errors while using as little overhead (i.e., extra bits transmitted for error correction or detection) as possible.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a low-overhead method for protecting multi-pulse speech coders from the effects of severe random or fading pattern bit errors.
Another object is to select bits to be protected in multi-pulse speech coding that will result in the best performance while minimizing the hardware and software required to support the protection scheme.
Briefly, in accordance with a preferred embodiment of the invention, a method is provided to combine a standard error correcting code (i.e., convolutional rate 1/2 coding and Viterbi trellis decoding) for protection against the effects of random errors with cyclic redundancy code (CRC) error detection for protection against the effects of fading errors. Compensation for detected fading errors takes place within the speech coder. Protection is applied only to the bits in the transmitted frame that are perceived to be significant, or "perceptually significant" bits.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing(s) in which:
FIG. 1 is a block diagram showing the implementation of the basic multi-pulse speech coding technique;
FIG. 2 is a graph showing respectively the input, the excitation and the output signals in the system shown in FIG. 1;
FIG. 3 is a table showing the protected and unprotected bits that are transmitted, per frame, to the multi-pulse receiver in the protection system of the invention;
FIG. 4 is a block diagram of the basic protection system according to the present invention;
FIG. 5 is a graph showing, respectively, the input signal waveform, the unprotected output signal waveform and the protected output signal waveform of the system shown in FIG. 4 for bit error effects in a 5% BER random pattern; and
FIG. 6 is a graph showing respectively the input signal waveform, the unprotected output signal waveform and the protected output signal waveform of the system shown in FIG. 4 for bit error effects in an 11% BER random pattern.
DETAILED DESCRIPTION
The Prior Art
In employing the basic multi-pulse technique using the conventional system shown in FIG. 1, the input signal at A (shown in FIG. 2) is first analyzed in a linear predictive coding (LPC) analysis circuit 10 to produce a set of linear prediction filter coefficients. These coefficients, when used in an all-pole LPC synthesis filter 11, produce a filter transfer function that closely resembles the gross spectral shape of the input signal. A feedback loop formed by a pulse generator 12, synthesis filter 11, weighting filters 13a and 13b, and an error minimizer 14, generates a pulsed excitation at point B that, when fed into filter 11, produces an output waveform at point C that closely resembles the input waveform at point A. This is accomplished by selecting pulse positions and amplitudes to minimize the perceptually weighted difference between the candidate output sequence and the input sequence. Trace B in FIG. 2 depicts the pulse excitation for filter 11, and trace C shows the output signal of the system. The resemblance of signals at input A and output C should be noted. Perceptual weighting is provided by weighting filters 13a and 13b. The transfer function of these filters is derived from the LPC filter coefficients. A more complete understanding of the basic multi-pulse technique may be gained from the aforementioned Atal et al. paper.
THE PREFERRED EMBODIMENT OF THE INVENTION
The particular coder intended to be employed in the preferred embodiment of the invention is of the general type described in copending patent applications Ser. No. 07/353,856 and Ser. No. 07/353,855. Table 1 provides the specifications for the coder.
TABLE 1______________________________________ Bit Allocation for Multipulse Coder______________________________________LPC/LSPF data Center 1 4 bits Difference 1 4 bits Center 2 4 bits Difference 2 4 bits Center 3 4 bits Difference 3 4 bits Center 4 3 bits Difference 4 2 bits Center 5 3 bits Difference 5 0 bitsPitch Lag 7 bits______________________________________Subframe Data(4 sets transmitted per frame)Data bits/subframe total bits/frame______________________________________Voiced/Unvoiced 1 bit.sup. 4 bitsDecisionSubframe Pitch Tap Gain (β) 5 bits 20 bitsAmplitude 1 6 bits 24 bitsPosition 1 6 bits 24 bitsAmplitude 2 6 bits 24 bitsPosition 2 6 bits 24 bits______________________________________
The transmitted data are divided into two groups: spectral and pitch lag data which are sent once per frame, and excitation and pitch tap data which are sent four times per frame. Each subset of excitation data represents one N/4 sample subframe of speech. For low-rate coders, N is frequently 256, so the subframe size is usually 64 samples.
The spectral information is comprised of 10 LPC coefficients. For transmission, the set of coefficients is first translated into 10 line spectrum pair frequencies (LSPF). Each pair of line spectrum frequencies is scalar quantized as a discrete center and a difference frequency. The total bit allocation for LPC coefficient transmission is 32 bits. The bit allocation for each LSPF is given in Table 1, above. (It will be noted that LSPF difference frequency 5 is not transmitted -- instead, a long term average is employed.)
The pitch lag is an integer number between 32 and 120. For transmission, the 7-bit binary equivalent is sent.
The subframe information is comprised of the data for two pulses (2 discrete locations and amplitudes), 1 bit for voiced/unvoiced (V/UV) decision, and the subframe pitch tap gain, β. Pulse positions are integer numbers generally between 0 and 63 and are sent as their 6-bit binary equivalents. Pulse amplitudes are nonuniformly quantized using a Max algorithm data-derived scalar quantizer; each pulse amplitude is allotted 6 bits. The pitch tap gain β is also quantized with a Max quantizer using 5 bits. The total number of bits for each subframe is 30; thus 120 bits per frame are used for excitation and pitch tap gain (β) information. If the pitch lag and LPC data (i.e., line spectrum pair frequencies) are included, a total of 159 bits per frame are sent.
For a predictive speech coder, such as a multi-pulse coder, the effect of bit errors on the output speech quality depends on: 1) the coefficient that is perturbed by the error, and 2) the significance of the individual bit perturbed within that coefficient. For example, one might expect that a bit error in the most significant bit of a pulse amplitude creates more havoc in the output than an error in the least significant bit of a pulse position. This is indeed true. The problem is to determine which group of bits require the most protection.
The optimal group of bits to protect can be determined by first deriving or measuring the perturbation (or SNR loss) of the output signal as a multivariate function of the probability of bit error in the N bits in the frame. The maxima of this function can be analyzed for the purpose of determining which bits to protect and how much protection to apply. For a simple speech coding technique, this function can be derived either analytically or by numerical methods; e.g., a system employing an 8-bit μ-law PCM (as per the CCITT standard digital telephone transmission format) would produce a function of eight variables. However for a complex system such as the multi-pulse coder described above, there are 159 bits in a frame, each of which produces a unique effect in the output signal when an error is made in that particular bit. This would require producing a sensitivity function of 159 variables by numerical methods, which is currently beyond available computing resources.
For the reasons stated above, a sub-optimal technique must be employed to choose the bits to be protected. For the present invention, a two-stage technique has been employed. In the first stage, a computer simulation was run comprising 159 independent speech coder runs, with each run having a 50% chance of a bit error for a particular bit within a frame. For example, for run #1, an error could only be made in the first bit (the most significant bit) of LSP (line spectrum pair) center frequency #1, with all other bits left unchanged. For run #2, errors were made only in the second bit of a frame. The process was continued for all 159 bits in a transmitted frame. Comparing the measured output signal-to-noise ratio (SNR) for each run to that for a run with no errors provided an indication of how much an error in a specific bit within a frame perturbs the output signal. The run numbers with the largest drop in SNR (compared to the no error run) indicate which bits are the most sensitive.
One drawback in using the method described above is that the effects of multiple bit errors within a frame are not taken into account. Errors in several different bits could combine to produce a much larger artifact than a single error. With a 5% random bit error rate, an average of eight bit errors occur during each frame, thereby nearly assuring presence of multiple bit errors in each frame at the design limit of the system.
During initial testing, an occurrence of the aforementioned problem was observed. A protection scheme was then implemented that covered eighty of the most significant bits, as determined by the computer simulation described above. The results at 5% random BER, while good, were disappointing because many spectral artifacts remained. Examining the list of protected and unprotected bits, it was noted that only about half of the LSP/LPC spectral coefficients were protected. Since the LSP/LPC data are especially prone to large amplitude artifacts when two or more frequency pairs are disturbed, this effect was not unexpected.
The second stage of the bit selection technique was to hand-tune the selection based on the simulation results and personal expertise. The final selection of protected bits is given in FIG. 3, which shows the transmitter bit stream for the multi-pulse coder, wherein LSP data is sent first, followed by pitch lag data, then followed by the data for the subframes. Bits marked "P" are protected bits. All of the LSP/LPC data are now protected, eliminating the previously observed short-term spectral artifacts. In addition, the pitch lag is completely protected. Subframe data that are protected comprise the voiced/unvoiced decision bits, the three most significant bits for Amplitude 1, and the two most significant bits for Amplitude 2. A total of sixty-three speech data bits are protected.
A convolutional code was used to protect the sixty-three selected bits from random pattern bit errors. Different codes of rate 1/2 and 2/3 were tested. The rate 2/3 codes were generally unable to correct 5% random bit errors. However, the rate 1/2 codes fared better, as expected. After some experimentation, the following two rate 1/2 convolutional codes (Table 2) were chosen. The first is more complex but gives better protection, whereas the second is simpler and performs only slightly worse. In each case, the optimal Viterbi decoder with hard decisions was used.
TABLE 2______________________________________Generators for Rate 1/2 CodersConstraint Length (bits) Polynomial #1 Polynomial #2______________________________________6 100000 1101013 101 111______________________________________
Experiments showed that performance of both codes were comparable, but at high bit error rates (5% or more), the short code performed slightly better, with reduced complexity. This is believed due to the decreased memory in the code so that decoding errors do not propagate as long.
While the convolutional coder/Viterbi decoder can protect the selected bits adequately in a 5% random BER environment, it will not protect against fades. To detect the fades, we merely detect the occurrence of a fade and pass this information along to the multi-pulse speech decoder. For purposes of this invention, a "fade" is considered to have occurred whenever the convolutional coder/Viterbi decoder fails to correct all of the errors in the protected bits. (This condition also occurs under very heavy random errors, and any uncorrected errors will have a degenerative effect on the speech decoder.) To detect the uncorrectable errors, cyclic redundancy code (CRC) checksums are added to the protected speech coder bits before convolutional encoding; in this manner, therefore, both the checksum bits and the critical speech coder bits are protected by the convolutional code. This configuration minimizes the probability of false fade detection. In the receiver, the checksum bits and critical speech bits are recovered by the Viterbi decoder, and then these bits are checksummed. A non-zero checksum output signal indicates presence of uncorrected errors in the output signal of the Viterbi decoder. For details on CRC checksum operation and implementation, see A. S. Tanenbaum, Computer Networks, Prentice-Hall (1981), pp. 128-132.
Under certain conditions, it is possible for a fade to be of such short duration that it destroys only a small segment of a transmitted frame. For this reason, the invention involves dividing the critical speech coder bits into three segments and employing a separate checksum of each segment. The segments are chosen such that the bits within a single segment contain localized information pertaining to a related group of coefficients. Thus an error in one segment of a frame can cause only a localized time or frequency disturbance in the output speech waveform. The first checksum checks the 32-bit LPC/LSPF data and 7-bit pitch data. The second sum checks the voiced/unvoiced (V/UV) decision bit and amplitude data for the first two subframes, and the third sum checks the same data for the second two subframes. The properties of the three checksums employed are given in Table 3 below.
TABLE 3______________________________________CRC Polynomials for Fade DetectionCRC # length (bits) polynomial______________________________________1 6 x.sup.6 + x.sup.2 + x.sup.1 + 12 5 x.sup.5 + x.sup.4 + x.sup.2 + 13 5 x.sup.5 + x.sup.4 + x.sup.2 + 1______________________________________
Each of these sums is capable of detecting any single error and any odd number of errors. The CRC of length five detects all double errors up to a message of length seven, all single burst errors with message lengths less than fifteen, 93.8% of the bursts of length six, and 96.9% of the bursts of length greater than six. Similarly, the length six CRC detects all double errors up to a message length of thirty-one, all burst errors of length less than six, 96.9% of the bursts of length seven, and 98.4% of the bursts of length greater than seven. Therefore, the chance of a missed detection is fairly small.
To minimize the perceptual effect of uncorrected fades on the output speech, we have devised an algorithm that changes the synthesis parameters/coefficients of the speech decoder according to the checksum reporting the error. The parameters/coefficients that are changed depend on the checksum(s) that report an error. The actions taken for detected errors are listed below, organized by checksum segment.
Checksum 1: LPC/LSP and Pitch Lag
For the entire frame:
1. Use the entire set of LPC coefficients from the most recent error-free set received. Continue using this set of coefficients until a new error-free set is received.
2. Perform the same action as in #1 for the pitch lag.
Checksum 2: Excitation Data, Subframes 1 and 2
During subframes 1 and 2:
1. Use the most recent error-free bit for the voiced/unvoiced decision.
2. Zero all pulse amplitudes.
3. Set the pitch tap gain to 0.85.
Checksum 3: Excitation Data, Subframes 3 and 4
During subframes 3 and 4:
1. Use the most recent error-free bit for the voiced/unvoiced decision.
2. Zero all pulse amplitudes.
3. Set the pitch tap gain to 0.85.
The behavior of this algorithm can be explained as follows. If uncorrected errors appear in the LPC/LSP spectral data or pitch, the previous values are used to ensure continuity of the overall spectral shape (i.e., the particular vowel sound) and the pitch period during a fade. This continuity serves to mask many errors that may occur in the excitation. For this reason, the excitation data is not as heavily protected (only twenty out of 120 bits) as the spectral and pitch data. In addition, separate, less powerful checksums are used for the excitation.
If an uncorrected error occurs in one of the excitation data blocks, the algorithm immediately zeros out any new excitation that would have been decoded, and uses only previously stored "clean" excitation contained in the pitch buffer. This action also prevents any artifacts from getting into the long term pitch buffer, where they would propagate until a silent period is encountered. Furthermore, the pitch predictor tap is set at a stable value of 0.85, which will provide continuity of sound over several frames, but ultimately decay the output sound to zero, should the fade last for a half-second or more. This is a valuable feature, since few would want to listen to a sustained vowel tone while stopped at a traffic light, e.g., "How are yoooooooo . . .", for the duration of the stop.
An additional benefit of multiple checksums within a frame arises if a very high random error rate is encountered, since it is possible that checksum errors will be detected during every frame. If only one checksum were used to trigger all of the above actions, the result would be very little output signal from the speech decoder. Having multiple (i.e., three) checksums decreases the probability that all three will fail during a given frame, and some excitation will therefore make it through to the output LPC filter stage. Thus this vocoder "evasive action" not only provides improved performance during fades, but also helps during periods of heavy random errors. This is a principal difference between the new algorithm described herein and the conventional system described by DalDegan et al., supra.
The new algorithm is implemented in the system shown in FIG. 4. In a transmitter portion 32, a multi-pulse speech coder 20 of the type generally described in copending application Ser. No. 07/353,855 and Ser. No. 07/353,855 provides a coded output signal to a frame sorter 21. The frame sorter separates the bits of a coded frame into two categories, protected and unprotected bits, these categories having been determined according to the procedures described above. Checksums are calculated for the protected bits by checksum generator 22. These sums are merged with the protected bits by multiplexer 23 and supplied to a convolutional encoder 24. The output signal of the convolutional encoder and the unprotected bits from frame sorter 21 are assembled in a multiplexer 25 to form a frame which is transmitted to a receiver 33.
At the receiver, the bits are first separated into encoded and non-encoded segments by a demultiplexer 26. The encoded bits are supplied to a Viterbi decoder 27 which provides output signals to a CRC checksum generator 29 and a frame merger 30 through demultiplexer 28. Frame merger 30 reconstructs the multi-pulse encoded speech bits and supplies these data to a multi-pulse speech decoder 31. Errors detected by CRC checksum generator 29 are coupled to multi-pulse speech decoder 31 which performs the actions taken for the detected errors as previously enumerated for checksum segments 1, 2 and 3.
Although the best method for evaluation of the results is through a listening test, a valid demonstration of performance can be obtained by examining the time-domain waveforms of output speech. FIG. 5 shows the system results for the phoneme /ha/ in a 5% BER random environment. It is clear that the protected output waveform resembles the input waveform more closely than that of the unprotected output waveform. FIG. 6 shows the same results for an 11% BER fading environment.
Performance of the protection scheme may also be measured by measuring the signal-to-noise ratio (SNR) for unprotected and protected coders operating in the same environment. Table 4 gives the results for 5% random and 11% fading environments. These measurements were taken for a segment of male speech, "Happy hour is over."
TABLE 4______________________________________SNR (dB) for Unprotected and Protected CodersRandom 5% BER Fading 11% BER______________________________________Unprotected Protected Unprotected Protected-9.03 +1.41 -7.15 +3.35Improvement Improvement+10.44 +10.5______________________________________
While analyzing Table 4, it should be kept in mind that absolute SNR values are not measures of quality of the output speech. The important number is the difference between the protected and unprotected SNR. The table clearly shows over a 10 dB improvement in both random and fading pattern errors.
While only certain preferred features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
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A low-overhead method of protecting multi-pulse speech coders from the effects of severe random or fading pattern bit errors combines a standard error correcting code (convolutional rate 1/2 coding and Viterbi trellis decoding) for protection in random errors with cyclic redundancy code (CRC) error detection for fading errors. Compensation for detected fading errors takes place within the speech coder. Protection is applied only to the perceptually significant bits in the transmitted frame.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is related to and claims priority from commonly owned U.S. Provisional Patent Application Ser. No. 60/858,560, entitled: System and Method for Aggregate Disposal, filed Nov. 13, 2006, the disclosure of which is incorporated by reference herein.
TECHNICAL FIELD
The disclosed subject matter is directed to systems and methods for waste disposal, and more particularly, to systems and methods for safely disposing of chat and tailings for underground storage.
BACKGROUND
Lead and zinc production involved crushing and grinding the mined rock to standard sizes and separating the ore. The remaining material or by product of this ore separation is known as “chat” or “tailings.” While some of the chat or tailings was deposited into the mine shafts once the mines were exhausted or abandoned, most of the chat and tailings were left behind in piles of leftover rock. For example, these “chat” and “tailings” piles cover over 40,000 acres in Cherokee County, Kansas, Ottawa and Craig Counties in Oklahoma, and Jasper County, Missouri, making it some of the most environmentally blighted land in the United States.
These wastes were also a source of contamination. Lead, zinc, and cadmium from the chat and tailings leached into the shallow ground water, contaminating local wells, and runoff moved contaminants into nearby streams and rivers. Wind also blew fine metal-bearing dust (from chat and tailings piles and roads made of chat and tailings) into the air, spreading the contamination to nearby non-mined areas.
It was attempted to dispose of the chat and tailings by depositing it back into the mines. However, the biggest problem faced was that the caverns in the mines were filled with water, that was contaminated. Simply dumping the chat and tailings 10 back down the mine casings (shafts) 12 into the caverns 14 , formed between the mine roof 14 a and the mine floor 14 b , that either were or over time filled with water, did not spread the chat and tailings 10 in a volume efficient manner. Rather, the chat and tailings accumulated in a conical pile 15 , as shown in FIG. 1 .
As a result most of the space in the caverns 14 , between the mine roof 14 a and the mine floor 14 b , was not filled (as shown in FIG. 1 ). Also, raw chat plugged the casings quickly. The chat was typically not screened for large particles, hindering the dumping process. Moreover, the chat and tailings just dumped into the casing 12 in this manner, as shown in FIG. 1 , and eventually returned above the ground surface 16 in the form of toxic dust.
Additionally, the chat and tailings can not be put in large holes and ditches on the ground surface and buried therein, as the rock table is too close to the ground surface. Accordingly, there is simply not enough over burden to facilitate such a process.
With additional reference to the mine cavern 14 , the total depth of the mine, from the surface 16 to the mine floor 14 b is represented by the arrows labeled D T . The depth through the dirt/rock strata 18 , from the surface 16 to the mine roof 14 a is represented by the arrows labeled D M , and the mine cavern height, from roof 14 a to floor 14 b is represented by the arrows labeled H M .
SUMMARY
The disclosed subject matter provides systems and methods for returning the materials of chat and tailing piles back underground, and typically back to the caverns of the former mines from which the ores were removed, in a long-term, pollution free and environmentally safe manner. The systems and methods disclosed provide for the movement of large amounts of chat and tailings in a cost effective manner. For example, this allows for the land above the mines to be reclaimed.
The disclosed subject matter is directed to systems and methods for disposing of aggregate material in the mine caverns from which these materials were originally obtained. In an apparatus for combining aggregate material, for example, chat or tailings, with water, an emulsion is formed. The water is drawn from the cavern, through a casing. The emulsion is pumped back into the cavern below ground level, through another casing, the pumping at pressures that overcome the forces of the water in the cavern and create turbulence in the water, such that the emulsion spreads throughout the cavern, at a good angle of repose, to maximize the amount of material disposed of.
The disclosed methods and systems employ separators, to render the chat and tailings, such that they can be blended into a homogeneous material, such as an emulsion, that is pumped under pressure, back into the underground caverns for safe disposal and storage. Additionally, the water used for the methods is the same water presently in the caverns, and therefore, avoids using and contaminating fresh water. These systems and methods also include methods for flowing emulsified chat or tailings, such that it can be deposited into the caverns, so as to flow through the voids, maximizing the amount of material that can be deposited in the caverns.
The disclosed subject matter is directed to a method for disposing of aggregate material. The method includes, obtaining aggregate material, and combining the aggregate material with water to form an emulsion. The emulsion is then pumped into a cavern below ground level at pressures that overcome the forces of the water in the cavern and create turbulence in the water, such that the emulsion spreads throughout the cavern.
There is also disclosed a system for disposing of aggregate material. The system includes an apparatus for combining aggregate material, for example, chat or tailings, with water to form an emulsion, and a pump. The pump acts on the emulsion, to pump it into a cavern below ground level at pressures that overcome the forces of the water in the cavern and create turbulence in the water, such that the emulsion spreads throughout the cavern.
BRIEF DESCRIPTION OF THE DRAWINGS
Attention is now directed to the drawings, where like numerals or characters indicate corresponding or like components. In the drawings:
FIG. 1 is a diagram of a mine cavern showing the present storage of chat or tailings;
FIG. 2A is a diagram of a system in accordance with the disclosed subject matter;
FIG. 2B is a diagram of the system of FIG. 2A , shown in an exemplary operation; and,
FIG. 3 is a diagram of a mine showing the results of the exemplary operation of FIG. 2B .
DETAILED DESCRIPTION
FIG. 2A shows the disclosed subject matter as a system 20 both above and below the ground surface 22 . The system 20 includes multiple components for processing the chat or tailings, emulsifying it, and causing it to flow in such a manner that emulsified material can fill a maximum amount of space in the underground caverns.
The system 20 includes an aggregate bin 30 , or other storage container, with scalper bars 32 , for the removal of large pieces, such a boulders, roots, and the like from the chat and tailings piles. The bin 30 also includes a gate 34 , that when released, opens the bin 30 and allows material to flow onto a first conveyer 40 .
The first conveyer 40 , is, for example, a standard conveyer belt system, and includes a screening unit 44 . The screening unit 44 is, for example, a shaker screen, for example, of an approximately half-inch size, to create material that is suitable to be flowable, for example, in an emulsion or slurry, as detailed below.
There is a second conveyer 50 , that receives material from the screening unit 44 . The belt of this conveyer 50 typically includes an electronic weighting system. There is a hopper 54 , that receives material from the second conveyer 50 . The hopper 54 includes a gated proportioning mechanism 56 .
A water line 60 runs under the hopper 54 at the gated proportioning mechanism 56 (with an opening into the water line 60 whose size may be set manually), to receive the aggregate. The water line 60 originates in an irrigation or first pump (P 1 ) 61 , that is typically submersible, as shown in a water source 62 . The water source 62 is, typically underground (through a layer or layers of strata 90 , hereinafter “strata layer”, such as dirt, rock and the like), and for example, in an underground cavern 64 of the former mine. The water is obtained from the water source 62 , as the pump (P 1 ) 61 pumps the water through the water line 60 (for example, an approximately six inch internal diameter pipe), that extends through the casing 65 a to the gated proportioning mechanism 56 . The pump 61 (P 1 ) may be, for example, a 1000 gallon per minute (gpm) deep well irrigation 40 horsepower (hp) pump.
The water line 60 ′ extends from the hopper 54 to a pump unit 70 . This pump unit 70 includes a second pump (P 2 ) 72 , powered by motor (M) 73 . A pipe 76 (for example, 12 inches in internal diameter) extends from the pump (P 2 ) 72 , into a mine casing (shaft) 65 b , for example, typically to depths proximate the last solid layer of rock prior (of the strata 90 ) to at least proximate the cavern 64 . The mine casing 65 b , is, for example, typically common to the underground cavern(s) 64 . The pump (P 2 ) 72 pulls emulsion or slurry (chat or tailings mixed with water) from the grated proportioning mechanism 56 and pushes it down the casing 65 b , through the pipe 76 . There may be a bore hole 65 x intermediate the casing 65 b and the cavern 64 , depending on the strata, dirt, rock, etc., for example, as shown in FIG. 3 . The casing 65 b alone, and with the bore hole 65 x , if necessary, form the down hole 88 . The second pump (P 2 ) 72 is, for example, a 12″ by 10″ sand pump, powered by a motor (M) 73 , that is, for example, an N-14 400 horsepower diesel engine, available from Cummins Engines. This pump (P 2 ) 72 pumps at pressures from approximately 15-30 pounds per square inch (psi).
Turning also to FIGS. 2B and 3 , an exemplary operation of the system 20 is detailed. Initially, chat or tailings 80 , from chat or tailings piles are dumped into the aggregate bin 30 , by a loader 82 . The chat or tailings 80 a passes through the scalper bars 32 , to remove large materials, such as boulders, tree roots and the like. The gate 34 is opened, such that the sifted chat or tailings is received on the first conveyer 40 . The first conveyer 40 , delivers the chat or tailings 80 b , to the screening unit 44 , where it is again sorted to be of an approximately half-inch size, to create material that is suitable to be flowable. The now sorted chat or tailings 80 c is received on a second conveyer 50 , that delivers it to the hopper 54 .
The chat or tailings 80 d (also known as aggregate) flows downward, by gravity to the gated proportioning mechanism 56 , where it enters the water line 60 (as shown by the broken line bent arrow 84 ). The water for the water line 60 is delivered from the pump (P 1 ) 61 , that moves the water in the direction of the thin arrows 85 . The aggregate 80 d combines with the water in the water line 60 , as the aggregate 80 d flows into the water at speeds sufficient to create an emulsion or slurry 80 e (the speed in which the aggregate flows to combine with the water is based on the speed of the second conveyer 50 —the speed of the conveyer 50 also influenced by the air temperature and other atmospheric conditions, and the size of the opening of the gated proportioning mechanism 56 ). The emulsion or slurry 80 e flows along a path indicated by the thick arrows 86 .
The pressure from the water (first) pump (P 1 ) 61 , coupled with the suction from the second pump (P 2 ) 72 moves the emulsion or slurry 80 e (in the water line 60 ′) into the second pump (P 2 ) 72 . The second pump 72 (P 2 ) pumps the emulsion 80 e , for example, into the pipe 76 for delivery to the mine cavern 64 . The pumping is at pressures of up to 30 psi, and, for example, at pressures of at least approximately 20 psi, in order to overcome the resistance of the water in the cavern 64 (any resistance from any ground water in the down hole 88 is negligible).
Turning also to FIG. 3 , the action of the pump (P 2 ) 72 is such that it forces the emulsion or slurry to move at a relative high velocity, for example, approximately 80-140 tons of chat or tailings per hour. This speed of movement causes a spreading action of the emulsion 80 e as it enters the cavern 64 . The spreading action, resulting from the high pumping speeds, also creates turbulence in the water of the cavern 64 , allowing for further spreading of the emulsion 80 e . The complete spreading action is shown by the broken lines 92 , and is such that the emulsion 80 e is completely spread over the maximum volume of the cavern 64 , at a good angle of repose, for example, a 1:1.5 to 1:3.5 (34° to 16°) slope on the sides, or less.
Example 1
A system in accordance with FIGS. 2A and 2B was built on 170 acres of mined land on the West edge of Commerce Okla. FIG. 3 shows a land profile, representative of the mined land of the aforementioned site. As shown in FIG. 3 , the mined land had a water level, approximately 12-20 feet below the ground surface 22 . The total depth of the mine (D T ) was approximately 180 to 235 feet. The depth to the mine cavern (D M ) 64 was approximately 150 to 195 feet. The height of the mine cavern (H M ) 64 was approximately 30 to 40 feet. The depth of the dirt/rock strata layer(s) 91 a (D L1 ), formed of dirt and shale, was approximately 100 to 120 feet, and the depth of the rock strata layer(s) 91 b (D L2 ), formed of solid rock, for example, bedrock, was approximately 150 to 195 feet. The cavern 64 was full of water.
A casing 65 b was made (drilled) to accommodate a 12 inch internal diameter pipe 76 , that extended from the pump (P 2 ) 72 , through the dirt and shale portion 91 a , as was an approximately 11 inch bore hole 65 x continuing from the dirt and shale portion 91 a through the solid rock portion 91 b to the cavern. The pipe 76 was extended to the rock portion 91 b of the strata layer 90 .
The irrigation pump (PI) 61 pumped water at approximately 1000 gallons per minute and combined with the aggregate delivered through the hopper 54 . The second pump (P 2 ) 72 pumped at pressures averaging at least 20 psi. The resultant emulsion 80 e was delivered at a relative high velocity, for example, approximately 120 tons of chat or tailings per hour, to the mine cavern 64 (also filled with water), between the mine ceiling 64 a and mine floor 64 b . The deposited emulsion 80 e settled at an angle of repose having a slope of approximately 1:3.
While the system 20 has been shown and described for chat or tailings, for example, from zinc or lead, this is exemplary only. The system 20 and methods for its use can also be used with other mined aggregates, or other aggregates, such a coal, dirt (e.g., contaminated soil) and the like.
While preferred embodiments have been described, so as to enable one of skill in the art to practice the disclosed subject matter, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the disclosed subject matter, which should be determined by reference to the following claims.
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A system for disposing of aggregate material in a mine cavern between a mine ceiling and a mine floor includes a first pump for pumping water from the cavern, a second pump for pumping emulsion to the cavern, a gated proportioning mechanism, and a water line extending between the first and second pumps and being accessible at the gated proportioning mechanism such that aggregate in the gated proportioning mechanism is introduced into the water line to form the emulsion. The second pump is configured such that the emulsion is pumped into the cavern at a pressure between about 20 pounds per square inch and about 30 pounds per square inch and settles on the mine floor in a pile having an angle of repose between about 1:1.5 and about 1:3.5. The pressure is insufficient to fracture the mine floor and insufficient to fracture the mine ceiling.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to sun shading and sheltering tops for watercraft, and more particularly to a sun bonnet assembly which is easily installed and broken down when removed for compact stowage.
2. Description of Related Art
The following art defines the present state of this field:
Gaschenko et al., U.S. Pat. No. 3,955,228 describes a boat shade comprising of a cover and a frame. The frame being formed of three inverted U-shaped components, one of an inverted U-shaped component of said frame being erected vertically and fastened at its ends to the opposite sides of the boat with the possibility of being pivoted. Two other inverted U-shaped components of the frame, arranged on both sides of the component of said frame. Hinges join said sliders to the ends of the inverted U-shaped components carrying the cover.
Pepper et al., U.S. Pat. No. 5,044,298 describes a boat comprising of a deck having a forwardly located helm, a canopy including a rearwardly located permanent cover, spaced apart portions extending forwardly defining an open opening. A second cover does not extend over said opening but when in an extended position it does extend over the opening. A canopy is located above said helm and spaced so as to permit an operator to stand or sit adjacent said helm.
Lewis, U.S. Pat. No. 5,070,807 describes a generally low profile, lightweight canopy assembly for a watercraft which embodies a transom member with a top edge, generally coplanar with peripheral side wall gunwale areas, said craft also having a plurality of interiorly disposed, peripherally spaced attachment means adaptable for attaching various items, a safety grab line, as well as canopy-supporting frame members.
Burns, U.S. Pat. No. 3,734,110 describes structures such as rack, shelters and the like which are adapted to be attached to a vehicle top that are assembles with corner members which are shaped to receive and grip different lengths of pipe. These structures are also provided to the vehicle top whereby the structures are readily attached to the top of a vehicle or to the side thereof.
Hansen, U.S. Pat. No. 4,582,016 describes a frame structure for supporting a flexible material for a marine vehicle convertible roof operative to provide protection for a vehicle occupant area having a predetermined length.
Voldrich, U.S. Pat. No. 5,009,184 describes a canopy for an open boat comprising a frame, the frame consisting of a pair of reversely L-shaped fixed angled tubular supports mounted on either side of the boat said supports having substantially horizontal and substantially vertical portions.
Pinkley, U.S. Pat. No. 3,572,353 describes a convertible top for boats and the like having a deck or support structure surrounding a passenger compartments and preceded by a windshield. Removable side rails extend from the top side edge of the windshield over the passenger seating area, and then downwardly to the deck. A cross bar extends between the rear of the front generally horizontal portion of the side rails.
Carmichael, U.S. Pat. No. 4,683,900 describes a canopy for use an open-topped vehicle such as a boat, tractor, or the like having two spaced-apart, substantially parallel, side rails.
Gibson, U.S. Pat. No. D307,347 describes a design for a fork lift canopy cover.
Stengel, U.S. Pat. No. D259,340 describes a design for and open side top for jeeps.
The prior art teaches various shading devices and top for watercraft and other vehicles. However, the prior art does not teach a shading device for a personal watercraft that provides shading from the sun overhead and also is not an obstruction to a rider being thrown laterally or rearwardly from the watercraft. The present invention fulfills these needs and provides further related advantages as described in the following summary.
SUMMARY OF THE INVENTION
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
In certain sport watercraft, usually referred to as personal watercraft, a rider and also one or more passengers, sit astride the craft's beam. In sharp turns or in rough waters, one or more persons are frequently thrown from the craft. This is generally not a problem as the clearance around the craft is sufficient such that a person thrown from the craft is not apt to be injured by striking structural members of the watercraft. However, it is desirable to provide a means for shading persons on such watercraft from the sun. The present invention is a shading means for personal watercraft. A primary objective of the present invention is to provide shade from the sun and rain in a personal watercraft without hampering operation of the craft. Another objective is to provide such a shading means that maintains the typical clearance around a personal watercraft so that a person thrown from the craft is not in danger of striking the shading means. A further objective is to provide such a shading means that also is easily broken down into small components for compact storage off the watercraft or stowage on it. A still further objective is to provide such a shading means that is light in weight so that operation and performance of the watercraft are not diminished by its use. A final objective is to provide such a shading means that is structurally sound so as not to be damaged with the normal use of a personal watercraft.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawings illustrate the present invention. In such drawings:
FIG. 1 is a top plan view of the preferred embodiment of the present invention;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a partial side elevational view in accordance with cutting line 4 — 4 of FIG. 1;
FIG. 5 is a partial side elevational view in accordance with cutting line 5 — 5 of FIG. 1;
FIG. 6 is a partial side elevational view in accordance with cutting line 6 — 6 of FIG. 1;
FIG. 7 is a perspective view of a portion of a bonnet support means taken in accordance with line 7 — 7 in FIG. 2;
FIG. 8 is a partial side elevational view in accordance with cutting line 8 — 8 of FIG. 3;
FIG. 9 is a partial side elevational view in accordance with cutting line 9 — 9 of FIG. 3; and
FIG. 10 is a partial side elevational view in accordance with cutting line 10 — 10 of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The above described drawing figures illustrate the invention, a shading device for a watercraft 5 . The shading device may be considered as a separate inventive entity from the watercraft or may be considered as an integral part thereof. In either case, the shading device includes a rigid superstructure 10 , as best seen in FIG. 2, preferably constructed of tubular members, preferably of aluminum or steel. It includes a rectangular frame portion 20 made-up of a pair of opposing longitudinally oriented elongate side members 20 A and 20 B, interconnected with a pair of opposing laterally oriented elongate end members 30 A and 30 B, the rectangular frame portion 20 is preferably a closed figure preferably comprising a pair of horizontally oriented, removably and mutually engaged, C-shaped members 40 A and 40 B which are joined amidships, and define an open central area 50 of the frame portion 20 , and it is supported in a horizontal orientation above a means for seating 60 of the watercraft 5 , by a strut means 70 . The strut means 70 is removably engaged with both the frame portion 20 and with the watercraft 5 so that the superstructure 10 is removably interconnected integrally with the watercraft 5 . The strut means 70 is preferably comprised of two laterally disposed strut members 70 A and 70 B, and its interconnection with the watercraft 5 is positioned forward of seating means 60 so that a person (not shown) falling sideways out of the watercraft 5 is not likely to strike the strut members 70 A and 70 B. This is a critically important feature of the construction of the superstructure 10 . Strut members 70 A and 70 B are interconnected with frame portion 20 at lateral frame member 30 B as shown in FIG. 4 . In the preferred embodiment, portion 76 A of strut members 70 A and 70 B terminates at a first attachment means 125 and 126 , joined by a screw, as shown in FIG. 4, the attachment means 125 and 126 preferably encircles frame member 30 B so as to ensure a strong but removable joint. It is assumed in this embodiment that portion 126 of the attachment means is permanently fixed to strut 76 A. Likewise, as shown in FIG. 5, the frame member 30 A is attached to struts 70 A and 70 B by second attachment means 115 , preferably a pair of collars screwed to struts 70 A and 70 BA respectively. Preferably, superstructure cover 80 is made of a flexible fabric material such as canvas or other fabric and extends over the rectangular frame portion 20 and the strut means 70 so as to be laid-out in a generally horizontal orientation for providing shade over the seating means 60 . A means is provided for removably attaching the cover 80 to the rectangular frame portion 20 so that the cover 80 is tightly stretched over it. Such an attachment means is preferably a sleeve hem 80 A sewn into the cover 80 along stitch line 82 , as best seen in FIGS. 4 and 10.
Preferably, at least one interconnecting strap 90 joins the shading device with the stern 6 of the watercraft 5 . The strap 90 provides a means for quickly releasing 90 A the strap 90 from the stern 6 when a lateral force is exerted upon it such as a persons body might, as it falls out of the craft 5 rearwardly. Such a quick release means mechanism is preferably a hook and loop type fastener solution such as Velcro®. The placement of strap 90 , too, is critical to the successful operation of the shading device since personnel frequently fall out of certain types of watercraft, such as high speed personal watercraft. When a rider strikes the strap 90 , it releases from the stern 6 of the craft 5 so that the rider and the shading device are not injured or damaged respectively.
The strut members 70 A and 70 B are preferably positioned generally in mutual parallel juxtaposition, one of the strut members 70 A running generally along the port side of the watercraft 5 , the other of the strut members 70 B running generally along the starboard side of the watercraft 5 , each of the strut members providing a generally horizontally oriented first portion 72 A and 72 B, laid adjacent to the deck 5 A of the watercraft 5 and engaged therewith for supporting the shading device. This first portion 72 A,B is positioned preferably forward of the operator or passenger on the watercraft 5 so that if either the operator or passenger are thrown sideways from the craft, they are unlikely to strike the first portion 72 A,B of either of the strut members 70 A,B. A generally horizontally oriented third portion 76 A and 76 B of the strut members 70 A,B is positioned above the deck 5 A and preferably extends above a substantial portion of the means for seating 60 of the watercraft 5 . This portion is generally over the top of the heads of operator or passenger so that it is not an obstruction to personnel movement either into or out of the craft 5 . A second portion 74 A and 74 B interconnects the first 72 A,B and third 76 A,B portions of each of the strut members 70 A,B preferably forming a modified (reverse) S-shaped pattern, so that it acts to support and hold the third portion 76 A,B in position at all times and along with it, the rectangular frame 20 of the superstructure 10 . Preferably, each of the strut members 70 A,B is comprised of two or more strut sections 78 A and 78 B which are interconnected to assemble each finished strut member 70 A,B.
A means for removably attaching 100 the superstructure 10 to the watercraft 5 is provided. This attaching means 100 , as seen in FIG. 6, is preferably a pair of tubular stanchions 100 A attached to the forward portion of the watercraft's deck 5 A. The first portion of the struts 72 A,B are engaged within these stanchions 100 A so as to be rigidly and securely held in place. A pin 100 B or other connector is preferably used to hold the strut means 70 in place within the stanchions 100 A.
While the invention has been described with reference to at least one preferred embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims.
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A shade for a personal watercraft includes a canopy and a canopy support frame. The shade is formed to provide a clearance such that a person thrown from the craft to either of its sides is not in danger of striking the canopy or its frame. The frame is easily broken down into small, easily transported components and is quickly assembled and mounted onto the craft. A breakaway strap holds the shade in position at the helm of the craft.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vibration-proofing or vibration-isolating device and, more particularly, to a device which has a fluid chamber for supporting a vibrating member and for preventing the transmission of vibration by applying onto a fluid within the fluid chamber pulsations in opposite phase with respect to pulsations caused by the vibrating member.
2. Description of the Related Art
In general, vibration-proofing or vibration-isolating devices are incorporated in supporting devices for vibrating members, particularly for vibrating members which generate multiple vibrations. These vibration-proofing devices prevent the transmission of vibrations, and also tend to damp those vibrations. For example, in a vehicle, high frequency vibrations (secondary vibrations) having the same frequency as a component of the multi degree vibration of the engine rotation are produced in a power unit of the vehicle by the explosive reaction in the combustion chamber of the engine. Also, low frequnency vibrations are produced in the body of the vehicle as a result of thrust from the road surface when the vehicle is running.
In U.S. Pat. No. 4,154,206, there is disclosed a suspension device for a vehicle to eliminate the transmission of vibrations from an engine to a support structure wherein a chamber is defined by a flexible wall and filled with liquid to improve the vibration level in the interior of the vehicle.
Vibration-proofing devices, shown in FIG. 1 and FIG. 2 attached to the present specification, are incorporated in a mounting unit which supports the power unit in the body. As well as preventing the transmission of secondary vibrations to the body, this vibration-proofing device damps out low frequency vibrations, and prevents shock to the power unit caused by these low frequency vibrations.
In the vibration-proofing or vibration-isolating device shown in FIG. 1, a first fluid chamber 5 and a second fluid chamber 6 are positioned between a housing main body 3, which is secured to a bracket 1 on the power unit side, and a frame body 4, which is secured to a bracket 2 on the body side. The first fluid chamber 5 and the second fluid chamber 6 are filled with fluid, and expand and contract according to the relative vibrations of the power unit and the body. The chambers 5 and 6 are partly defined by first and second elastic members 7 and 8 respectively which are made of an elastic material such as rubber. The first fluid chamber 5 communicates, through an orifice 11a formed in a first partition 11, with a third fluid chamber 10. The third fluid chamber 10 is constructed so that it can expand and contract by means of a diaphragm 9. The second fluid chamber 6 communicates, through an hole 14a formed in a second partition 14, with a fourth fluid chamber 13. The fourth fluid chamber 13 is constructed so that it can expand and contract by means of a bellows 12. The bellows 12 penetrates the housing main body 3 in a freely slideable manner, and is elastically deformed in response to the vibrations of a vibrating element 16 which is activated by means of a solenoid 15. Pulsations are generated in the fluid within the fourth fluid chamber 13, that is, in the fluid within the second fluid chamber 6. The solenoid 15 is connected to a control circuit 18 through a drive circuit 17 to be controlled according to the crank angle of an engine E of the power unit which is detected by a crank angle sensor 19.
In this type of vibration-proofing device, when secondary vibration is produced in the power unit from the action of the piston strokes or the explosive reaction of the combustion chamber of the engine E, the vibrator 16 is activated when electricity flows in the solenoid 15, therefore the bellows 12 is driven by means of the vibrator 16 so as to expand and contract. Accordingly, pulsations in opposite phase with respect to pulsations caused by the secondary vibration are generated by the elastic deformation of the bellows 12 in the fluid within the second fluid chamber 6. As a result, the transmission of secondary vibrations to the body is prevented. In this vibration-proofing device, the fluid within the first fluid chamber 5 and the third fluid chamber 10 flows through the orifice 11a when low frequency and large amplitude vibration is generated. Thus, the vibrations are damped out.
In the vibration-proofing device shown in FIG. 2, a first fluid chamber 22 is defined by a flexible wall 23 between a power-unit-side mounting member 20 and a body-side mounting member 21. The first fluid chamber 22 is filled with fluid and capable of expanding and contracting, coping with the vibration between the power unit and the body. In addition, a diaphragm 24, which is attached to the body-side mounting member 2, defines a second fluid chamber 26. The second fluid chamber 26 is capable of expanding and contracting and separated from a fluid chamber 22 by a partition 25. The orifice 25a, which communicates with the first fluid chamber 22 and the second fluid chamber 26, is formed in the partition 25. At the same time, a control chamber 27 is defined by a cover 29 fitted into an indented section. The control chamber 27 communicates with the first fluid chamber 22 through a first control orifice 29a formed in the cover 29, and communicates with the second fluid chamber 26 through a second control orifice 25b formed in the low indented wall of the partition 25. In addition, a control plate 28 is enclosed and floats in the fluid in the control chamber 27. This control plate 28 is pressurized by the flow of fluid through the first control orifice 29a and the second control orifice 25b into the control chamber 27, and closes off the first control orifice 29a or the second control orifice 25b.
In this type of vibration-proofing device, when high frequency low amplitude vibrations are generated in the power unit, the fluid in the first fluid chamber 22 and second fluid chamber 26 flows through the first control orifice 29a and the second control orifice 25b. Because there is flow through the orifice 25a, the spring constant of this vibration-proofing device drops, and the vibration transmitted to the body from the power unit is reduced. In addition, when low frequency high amplitude vibrations are generated at the body side, both the volumes change in the first fluid chamber 22 and the volume of fluid flowing through the first control orifice 29a increases. As a result, the control plate 28 has pressure applied by the fluid, and the first control orifice 29a or the second control orifice 25b is blocked off. Accordingly, the fluid flows through the orifice 25a only and the vibrations are damped.
However, the vibration-proofing device shown in FIG. 1 drives the bellows 12 by means of the vibrator 16, resulting in requiring vibrator 16 to be heavy. This requires a large vibration-proofing device and offers considerable restriction on its installation, as well as necessitating a large model solenoid 15. It also has the drawback of requiring a large consumption of electrical power. In particular, the solution of these defects is urgently required in the event that the movement of the vibrator 16 must follow up high frequency vibrations to cause this vibration-proofing device to function effectively against high frequency vibrations.
In addition, in the vibration-proofing device shown in FIG. 2, the entire spring constant is reduced as a result of the communication between the first fluid chamber 22 and the second fluid chamber 26, thereby preventing transmission of the high frequency vibration. In other words, this vibration-proofing device has the drawback of not being able to adequately diminish the transmitted high frequency vibrations because it does not actively possess the function of preventing the transmission of vibration.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vibration-proofing device in small size and light weight.
It is another object of the present invention to provide a small-sized, light weight vibration-proofing device without a decline in vibration-proofing performance against high frequency vibration.
It is another object of the present invention to provide a vibration-proofing device having an excellent ability to follow up high frequency vibration.
It is another object of the present invention to provide a vibration-proofing device which is capable of constructing a vibrator thereof in small size and light weight to cause pulsations in liquid in the vibration-isolating device.
It is another object of the present invention to provide a vibration-proofing device having a fluid chamber provided between a vibrating member and a vibrated body and filled with liquid so as to expand and contract to support the vibrating member.
It is another object of the present invention to provide a vibration-proof device having a fluid chamber filled with liquid which is subjected to pulsations which have opposite phase to pulsations caused by the vibration of the vibrating member.
Briefly described, these and other objects of the present invention are accomplished by the provision of at least one fluid chamber between a vibrating member and a vibrated member in which fluid is filled, and which expands and contracts in correspondence with the vibration of the vibrating member. In the fluid within this fluid chamber, pulsations occur in opposite phase with respect to pulsations generated by means of the vibrating member. The means for providing the pulsations in opposite phase may comprise a substantially plate-shaped member fabricated from a magnetic material, which makes up a partition partly defining the fluid chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features, and advantages of the present invention will be more apparent from the following description of a preferred embodiment, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a partial cross-sectional view of a conventional vibration-proofing device;
FIG. 2 is a cross-sectional view of another conventional vibration-proofing device;
FIG. 3 is a cross-sectional view of a first embodiment of the present invention;
FIG. 4 is a cross-sectional view of a second embodiment of the present invention;
FIG. 5 is a cross-sectional view of a third embodiment of the present invention;
FIG. 6 is a cross-sectional view of a fourth embodiment of the present invention;
FIG. 7 is a cross-sectional view of a fifth embodiment of the present invention;
FIG. 8 is a cross-sectional view of a sixth embodiment of the present invention;
FIG. 9 is a cross-sectional view of a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Here, several embodiments of the present invention are explained, based on the drawings. Furthermore, in each of the embodiments described below, the vibration-proofing device of the present invention is shown in the application as a mounting device positioned between the power unit and body of a vehicle.
Referring to FIG. 3, there is shown a first embodiment of a vibration-proofing or vibration-isolating device according to the present invention.
First, the construction of the vibration-proofing device is explained. A bracket 31 is provided on a power unit which is not shown in the drawing. A bracket 32 is provided on a body which is not shown in the drawing. The vibration-proofing device includes a mounting unit 33 which is positioned between the brackets 31 and 32. The mounting unit 33 is attached between the power unit and the body in several locations, which are not shown on the drawing, and it provides support for the power unit to the body.
The mounting unit 33 has a first mounting member 35, which is secured to the bracket 31 on the side of the power unit by a bolt 34, and a second mounting member 36, which is secured to the bracket 32 on the side of the body. In addition, the second mounting member 36 comprises a substantially-circular rigid plate 37 and an substantially-tubular frame member 38 connected to the rigid plate 37. A tubular-shaped first elastic member 39 made of an elastic material such as rubber is positioned between the first mounting member 35 and the rigid plate 37. In addition, a tubular second elastic member 40 made of an elastic material such as rubber is set into the open end of the frame member 38. The first elastic member 39 secures its open end section at the lower part thereof to the rigid plate 37, as well as securing its upper end section thereof to the first mounting member 35. Fitted onto the frame member 38 is a substantially cylindrical casing 41 which is formed with an open orifice 41a. In the casing 41, a circular groove 41b is formed, which is open to the open orifice 41a. In this groove 41b, an substantially disk-shaped flat vibrator 42 constructed from a ferro magnetic material is freely inset so as to be freely displaceable in the top to bottom direction in the drawing. The vibrator 42, the first elastic member 39, and the casing 41 forms a first fluid chamber 43. The vibrator 42, the second elastic member 40, and the casing 41 forms a second fluid chamber 44. It will be noted that the vibrator 42 is a partition between the first and second fluid chambers. An incompressible fluid such as oil, for example, is filled into a first fluid chamber 43 and the second fluid chamber 44, and the vibrator 42 floats in this fluid. It is possible to vary the volume of the first fluid chamber 43 as a result of the relative displacement of the brackets 31 and 32, that is, as a result of the deformation of the first elastic member 39. It is also possible to vary the volume of the second fluid chamber 44 as a result of the deformation of the second elastic member 40. In additon, each of some ring-shaped solenoids 45 and 46 are stored within the casing 41 and spaced apart from each other in the direction of the displacement of the vibrator 42. These solenoids 45 and 46 are each connected to a drive circuit 47, and they are alternatively powered by the drive circuit 47 to activate the vibrator 42.
A crankshaft 48 of the power unit is provided with a crank angle sensor 49 to detect the crank angle of the crankshaft 48. The crank angle sensor 49 is wired to a control circuit 50 and the signal which indicates the crank angle is output to the control circuit 50. The control circuit 50, according to the output signal from the crank angle sensor 49, outputs to a drive circuit 47 a pulse signal which is synchronous with the secondary vibrations of the power unit. The drive circuit 47, according to the pulse signal of the control circuit 50, applies an opposite phase drive current to each of two solenoids 45 and 46 which activates the vibrator 42. When both the body and the power unit are displaced in the bounding direction by secondary vibrations, that is, in the direction to make bracket 31 and 32 close to each other, the drive current output by the drive circuit 47 activates only the lower solenoid 46, and it has the phase which energizes the vibrator 42 in the lower direction with reference to the drawing. In addition, when both the power unit and the body are displaced in the rebounding direction by secondary vibrations, only the upper solenoid 45 is excited, and it has the phase which energizes the vibrator 42 in the upper direction with reference to the drawing.
With this vibration-proofing device, because the vibrator is substantially in the form of a plate and is made from a magnetic material, the magnetic flux passing through the vibrator increases, and provides adequate exciting force to the vibrator. Accordingly, it is possible to construct this vibrator in small size and light weight, and its ability to follow up high frequency vibrations is excellent, and its effectiveness in preventing the transmission of vibration becomes even greater.
Next, the operation of the first embodiment of the vibration-proofing device is explained.
In a vehicle, the mounting device which supports the power unit on the body is loaded with both a high frequency low amplitude vibration from the power unit, and a low frequency high amplitude vibration from the body side. The main components of the former vibration are the vertical vibration resulting from the reciprocating action of the pistons of the power unit, or the roll direction vibration resulting from the component force of the explosive pressure in the combustion chamber of the power unit. This vibration, namely secondary vibration, has the same frequency as a component of the multi degree vibration of the engine rotation of the power unit, and is transmitted to the body as sound, causing a resonant noise inside the vehicle. In addition, the main components of the latter vibration are the vertical vibrations resulting from running on an uneven road surface, or the roll direction vibrations in F.F vehicle, caused by sudden starts and stops of the vehicle. Because this vibration is produced in a frequency range which conforms closely to the resonant frequency of the vibration system of the mounting device (about 20 Hz), the resonance phenomena for shaking the car are generated. Accordingly, the vibration-proofing device positioned between the power unit and the body of the vehicle is required to prevent the transmission of the above-mentioned high frequency vibrations to the body, and also to damp out the abovementioned low frequency vibrations.
In the vibration-proofing device according to the present invention, when the power unit causes the second vibration synchronizing with the component of the multi degree vibration of the engine rotation, brackets 31 and 32 are relatively displaced. Because the first elastic member 39 is deformed by expanding and contracting, a volume change is produced in the first fluid chamber 43 and pulsations are produced in the fluid within the first fluid chamber 43. When both the power unit and the body change in the bounding direction, these pulsations are on the higher pressure side in phase, and when the power unit and the body change in the rebound direction, the pulsations are on the lower pressure side in phase.
At the same time, as previously described, the control circuit 50, according to the crank angle of the engine, controls the solenoids 45 and 46 through the drive circuit 47, and the vibrator 42 activated by the solenoids 45 and 46 vibrates in the vertical direction. Therefore, an opposite phase pulsation to the secondary vibration from the power unit is generated in the fluid in the fluid chamber 43. That is, the vibrator 42 vibrates at the same frequency as the previously mentioned secondary vibrations from the power unit. At the same time, when the pulsations of the fluid contained within the first fluid chamber 43 caused by its secondary vibrations is on the lower pressure side in phase, the vibrator 42 is displaced toward the first fluid chamber 43 to produce pulsations on the higher pressure side in phase in the fluid contained within the first fluid chamber 43. In addition, when the pulsations of the fluid contained within the first fluid chamber 43 caused by the secondary vibrations is on the higher pressure side in phase, the vibrator 42 is displaced toward the side of the second fluid chamber 44 to produce pulsations on the lower pressure side in phase in the fluid contained within the first fluid chamber 43. Accordingly, because the pulsations produced in the fluid within the first fluid chamber 43 by the secondary vibrations of the power unit are absorbed by the pulsations produced in the fluid contained within the first fluid chamber 43 by the vibrations of the vibrator 42, the transmission of such high frequency vibration to the body is limited.
Here, the pulsations counteracting the pulsations produced by the secondary vibrations of the power unit are generated by the vibrator 42, which is made from a ferro-magnetic material, has a plate-shaped form and is activated by the solenoids 45 and 46 installed on both sides of the vibrator in the direction of the vibration. Accordingly, it is possible to make the vibrator 42 as a small-sized, light weight unit. In addition, because a large amount of magnetic flux passes through the vibrator 42, this vibrator 42 can be activated by a comparatively small magnetic force. In other words, because vibrations are produced in the vibrator 42 at higher frequency levels without making the solenoids 45 and 46 large, it is possible to prevent the transmission of vibrations at higher frequency levels. Furthermore, in this embodiment of the present invention, the vibrator 42 is not constructed as a spring vibration system where the vibrator 42 is subjected to resonance phenomena because this vibrator 42 is activated by the solenoids 45 and 46 which are installed on both sides in the direction of the vibrations. Accordingly, it is possible to produce higher frequency vibrations in the vibrator 42, and the follow-up to the high frequency vibration of this vibration-proofing device is even more improved.
Next, when low frequency high amplitude vibrations are generated on the body, the brackets 31 and 32 undergo a relatively large displacement, and the first elastic member 39 undergoes a large deformation. A large pressure difference is produced in both the fluid in the first fluid chamber 43 and the fluid in the second fluid chamber 44. For this reason, the fluid pressure causes the vibrator 42 to adhere to the end surface of the groove 41b, closing off the channel between the first fluid chamber 43 and the second fluid chamber 44, and sealing the fluid in the first fluid chamber 43. Accordingly, the first elastic member 39 is supported by the incompressible fluid in the first fluid chamber 43 and becomes extremely rigid, preventing any substantial vibration in the power unit.
Referring to FIG. 4, there is shown a second embodiment of the vibration-proofing or vibration-isolating device according to the present invention.
In this vibration-proofing device, an orifice 42a is formed close to the center of the vibrator 42, allowing communication between the first fluid chamber 43 and the second fluid chamber 44.
In this vibration-proofing device, when low frequency high amplitude vibrations are generated on the body and a large volumetric change is produced in the first fluid chamber 43, fluid flows through the orifice 42a formed in the vibrator 42 and damps out this vibration. In other words, when the first elastic member 39 undergoes pressure deformation and the volume of the first fluid chamber 43 is reduced, the fluid contained within the first fluid chamber 43 flows through the orifice 42a into the second fluid chamber 44. For this reason, the second elastic member 40 bulges outward and the volume of the second fluid chamber 44 increases. On the contrary, when the first elastic member 39 undergoes a tension deformation and the volume of first fluid chamber 43 increases, the second elastic member 40 bulges inward and the fluid contained within the second fluid chamber 44 flows through the orifice 42a into the first fluid chamber 43. In this way, inconveniences such as shuddering of the vehicle are prevented because this vibration is damped out by the fluid flowing through the orifice 42a. Other details of construction of the second embodiment of the present invention are the same as previously outlined for the first embodiment, so that further explanation will be omitted here.
Referring to FIG. 5, there is shown a third embodiment of the vibration-proofing or vibration-isolating device according to the present invention.
In this vibration-proofing device, the periphery of a flexible or elastic member or diaphragm 51 is fitted into the groove 41b of the casing 41. On both sides of the diaphragm 51 in the vertical direction with reference to the drawing, some disk-shaped diaphragms 52 and 53 made from ferromagnetic material are secured by means of a bolt 55 and a nut 56 to make up a vibrator 54. This vibrator 54 serves as a partition to separate the first fluid chamber 43 and the second fluid chamber 44. In addition, when the diaphragms 52 and 53 vibrate in the vertical direction, the diaphragm 51 comprising a flexible member is distorted. This causes the first fluid chamber 43 and the second fluid chamber 44 to expand or contract.
Also in this embodiment of the vibration-proofing device according to the present invention, the vibrator 54 is light in weight and has good following characteristics with respect to high frequency vibrations, because the two diaphragms 52 and 53 are combined with the diaphragm 51 to form the vibrator 54. In addition, because the two diaphragms 52 and 53 are activated by the solenoids 45 and 46, a large amount of magnetic flux passes through the diaphragms 52 and 53, resulting in the entirely great magnetization, and the exciting force of the vibrator 54 becomes large. Furthermore, because the modulus of elasticity of the diaphragm 51 is so minute that it can be ignored, any vibration system with a resonant frequency is not formed in the present device, and the following characteristics of the present device with respect to high frequency vibration becomes even better. Other details of construction of this third embodiment of the present invention are the same as previously outlined for the first and second embodiments, so that further explanation will be omitted here.
Referring to FIG. 6, there is shown a fourth embodiment of the vibration-proofing or vibration-isolating device of the present invention.
In this vibration-proofing device, as shown in the drawing, an orifice 55a is formed in the bolt 55 of the third embodiment of the vibration-proofing device shown in FIG. 5, providing communication between the first fluid chamber 43 and the second fluid chamber 44.
In this vibration-proofing device, when low frequency high amplitude vibrations are generated on the body, the fluid flows between the first fluid chamber 43 and the second fluid chamber 44 through the orifice 55a, and damps out these vibrations. Accordingly, no large shaking takes place in the power unit, and the generation of resonance phenomena, such as shuddering of the vehicle, is prevented. Other details of construction of this fourth embodiment of the present invention are the same as previously outlined for the third embodiment so that further explanation will be omitted here.
Referring to FIG. 7, there is a fifth embodiment of the present invention.
In this embodiment of the present invention, a valve seat 41c is formed integrally with the casing 41 so as to face the orifice 55a of the vibrator 54. When the vibrator 54 is distorted toward the first fluid chamber 43, the upper end surface of the bolt 55 contacts the valve seat 41c, making it possible to close off the orifice 55a. Also, a rapid-operation detection circuit 58 is joined to the solenoid 45 on the side of the first fluid chamber 43 through a second drive circuit 57. The rapid-operation detection circuit 58 detects the vehicle's rapid rotation, rapid braking, or rapid acceleration by an accelerometer, or by the action of the accellerator pedal, that is, the opening degree of the throttle valve. When the fast acceleration occurs, the rapid-operation detection circuit 58 outputs drive signals to the second drive circuit 57.
In this type of vibration-proofing device, the rapid-operation detection circuit 58 outputs drive signals to the second drive circuit 57 when the vehicle accelerates quickly, and the second drive circuit 57 provides excitation power to the solenoid 45 on the side of the first fluid chamber 43. Accordingly, the vibrator 54 is displaced toward the first fluid chamber 43, and the top end surface of the bolt 55 contacts the valve seat 41c, closing off the orifice 55a so that the first fluid chamber 43 is isolated from the second fluid chamber 44. For this reason, the first elastic member 39 is supported by the incompressible fluid sealed into the first fluid chamber 43, so that no great degree of deformity takes place, thus preventing vibration of the power unit even during rapid acceleration of the vehicle. Other details of construction and use of this embodiment of the present invention are the same as previously outlined for the fourth embodiment, so that further explanation will be omitted here.
Referring to FIG. 8, there is shown a sixth embodiment of the vibration-proofing or vibration-isolating device of the present invention.
The vibration-proofing device of the embodiment comprises another elastic member 59 of substantially disk shape made from an elastic material like rubber and defing the first fluid chamber 43 with the periphery of the elastic member 59 being fitted in the casing 41, and a vibrating plate or diaphragm 60 for a vibrator 61 provided with a disk portion 60a and a fitting portion 60b which is fitted into the elastic member 59 to secure the diaphragm 60 to the elastic member 59. Disposed between the diaphragm 60 and the casing 41 is a spring 62 to biase the diaphragm 60 toward the first fluid chamber 43.
Disposed within the casing 41 below the disk portion 60a with reference to the drawing is a substantially annular solenoid 46 to excite the diaphragm 60 and attract the same downwardly with reference to the drawing. The solenoid 46 displaces the diaphragm 60 against the biase force of the spring to cause vibrations in the diaphragm 60. The vibrations of the diaphragm 60 causes deform in the elastic member 59 to expand and contract the first fluid chamber 43. Provided between the rigid plate 37 and the casing 41 is a stopper 63 to control any excessive displacement of the diaphragm 61. The stopper 63 has a plurality of ports 63a in network.
In this type of vibration-proofing device, when secondary vibrations are produced in the power unit, the pulsations generated in the fluid contained within the first fluid chamber 43 are offset by the pulsations caused by the vibration of a vibrator 61. To explain in more detail, in the case where the brackets 31 and 32 are displaced toward each other, the first elastic partition 39 is deformed by pressure, and pulsations with the high pressure side phase are generated in the first fluid chamber 43. At this time, the vibrator 61 is powered by the drive circuit 47, based on the output signal of the crank angle sensor 49 for attracting a diaphragm 60 to displace the diaphragm 60 in the lower direction against the elastic force of a spring 62. For this reason, the elastic member 59 is displaced in the lower direction together with the diaphragm 60, causing pulsations in the fluid within the first fluid chamber 43, the pulsations having the lower pressure side phase. Accordingly, these pulsations are offset by pulsations of the secondary vibration from the power unit, and the transmission of vibration to the body is restricted. In the same way, when pulsations having the low presssure side phase are generated by secondary vibrations in the fluid contained within the first fluid chamber 43, the supply of power to the solenoid 46 is terminated, and the diaphragm 60 is displaced toward the first fluid chamber 43 by the spring 62. For this reason, the elastic member 59 also is displaced in the upward direction together with the diaphragm 60, and pulsations with the high pressure side phase are generated in the fluid within the first fluid chamber 43, offsetting the pulsations caused by the secondary vibration. In other words, because the pulsations produced in the fluid within the first fluid chamber 43 by the secondary vibrations with the power unit are offset by pulsations with the opposite phase caused by the vibrator 61, the transmission of these secondary vibrations to the body is prevented.
In addition, in the case where low frequency high amplitude vibrations are produced on the vehicle, because an incomprissible fluid is sealed within the first fluid chamber 43 to support the first elastic member 39 thereby providing great rigidity, the first elastic member 39 does not undergo a major deformation, so that high amplitude vibration in the power unit are prevented. Furthermore, in case of this type, damage to the vibrator 61, especially to the elastic member 59, is prevented because excessive upward deformation in the elastic member 59 is prevented by the engagement of the elastic member 59 against the stopper 63 and excessive downward deformation by the engagement of the diaphragm 60 against the casing 41. Other details of construction of the sixth embodiment of the vibration-proofing device of the present invention are the same as previously outlined for the other embodiments, so that further explanation will be omitted here.
Referring to FIG. 9, there is shown a seventh embodiment of the present invention.
As shown in the previously discussed first embodiment of the present invention, in this embodiment, the second elastic member 40 is secured to the opening of the frame member 38 at the lower end thereof, thereby defining the second fluid chamber 44 which is free to expand or contract. There is also an orifice 61a which is formed in the vibrator 61 specifically through the portion of the diaphragm 60 fitted into the elastic member 59, which is now a partition between the first and second fluid chambers, and through the center of the elastic member 59 to allow communication between the second fluid chamber 44 and the first fluid chamber 43.
In this vibration-proofing device, when low frequency high amplitude vibrations are generated in the body and a large deformation is created in the first elastic partition 39, the fluid in the first fluid chamber 43 and the second fluid chamber 44 flows through the orifice 61a and damps out these vibrations. That is, when the first elastic member 39 undergoes an elastic deformation, the fluid contained within the first fluid chamber 43 flows through the orifice 61a into the second fluid chamber 44, causing the second elastic member 40 to expand. In the same way, when the second elastic member 40 undergoes a deformation through expansion, the fluid in the second fluid chamber 44 flows into the first fluid chamber 43, deforming the second elastic member 40, and damps out these low frequency, high amplitude vibrations. Furthermore, when the vibrator 61 vibrates in response to the secondary vibrations described above, because these secondary vibrations are greater than 20 Hz, the fluid does not flow through the orifice 61a. In other words, the pulsations given to the fluid within the first fluid chamber 43 by the vibrator 61 are not affected by the orifice 61a. Other details of construction and use of this embodiment of the present invention are the same as previously outlined for the other embodiments. Other objects and further scope of applicability of the present invention will become apparent from the detailed description given above. It should be understood, however, that the detailed description of a specific example, while indicating a preferred embodiment of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent from this detailed description to those skilled in the art.
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A vibration-proofing device according to the present invention includes at least one fluid chamber in which fluid is filled between a vibrating member and a vibrated member. The fluid chamber is formed which expands and contracts from the vibration of the vibrating member. In the fluid within this fluid chamber, opposite phase pulsations are generated by means of a vibrator. The vibrator comprises an almost plate-shaped member fabricated from a magnetic material, which makes up one part of a partition forming the fluid chamber. The vibrator is activated by solenoids.
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This is a divisional of co-pending application Ser. No. 855,471, filed on Apr. 24, 1986, U.S. Pat. No. 4,789,548.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the treatment of heartworms or adult filaria in the heart and circulatory systems of dogs. More particularly, the invention relates to a combined preventative treatment and therapeutic treatment for dogs infested with adult filaria by using vasoconstrictors and bronchial dilators, as well as cardiac and sympathetic stimulants to counteract the effects of therapeutic treatment with diethylcarbamazine. Since it is speculated that the treatment of adult filaria with diethylcarbamazine results in the release of a toxin which causes the body to secrete acetylcholine, a chemical which acts to produce massive vasodilation and bronchial constriction in the animal, treatment of the adult filaria requires application of both preventative and therapeutic medicine. The preventative treatment is designed to use certain vasoconstricting, bronchial dilating and/or cardiac and sympathetic stimulant medication such as prednisone, ephedrine, digoxin and dextroamphetamine sulfate to counteract the undesirable vasodilation and bronchial constriction with resulting cardiac weakening in dogs which are treated with the diethylcarbamazine.
The adult heart worm parasite or "filaria" slowly and painfully kills hundreds of thousands of dogs annually. The parasite is particularly prolific in the coastal states, where it is estimated that at least 80 percent of all dogs which remain outside in mosquito-infested areas will have an infestation of heartworms before they reach three years of age. None of the currently used veterinary treatments are highly effective and safe, and most cause severe pain, swelling and in some cases, necroses of the tissues.
2. Description of the Prior Art
Diethylcarbamazine has been used for years under a variety of trademarks such as "Caricide", a trademark of the American Cyanimid Company, for the treatment of adult filaria or "filiariasis" in dogs. Caricide was used during World War II to treat filiariasis in human patients in the south pacific theatre where infestation became a problem in American troops in that area. Diethylcarbamazine was used throughout the 1950's and 1960's by veterinarians as a successful treatment of healthy dogs for infestations of dirofilaria immitis, which is the most common species of adult filaria infecting dogs in the coastal United States. Sometime after the era ofthe 1960's, Caricide was discontinued due to complaints that various side effects and occasional deaths occurred from its use in heavily affected dogs having large numbers of worms in the heart. This supposed drug-sensitivity reaction was noted to be more prevalent in weak and emaciated dogs which were subjected to long-standing stress from the infestations and it was observed to only occurr in a small percentage of those dogs treated.
U.S. Pat. Nos. 2,467,893, 2,467,894, and 2,467,895, dated Apr. 19, 1949, to Kushner, el al, U.S. Pat. No. 2,643,255, dated June 23, 1953, to Gustave, et al and Re. 23,701, dated Aug. 18, 1953, to Stewart, et al, disclose the use of carbamyl compounds as treating agents for filariasis in veterinary practice. U.S. Pat. No. 4,172,118, dated Oct. 23, 1979, to Baetz, discloses the use of diphenylamine as a detoxicant for drugs administered to animals.
I have found through extensive experience and observation in using the chemical Caricide or diethylcarbamazine, that upon absorption into the bloodstream of a dog and upon making contact with adult heartworms in the heart of the dog, the diethylcarbamazine causes release of a toxin by the heartworms into the bloodstream. This toxin causes the parasympathetic system of the dog to produce acetylcholine, which, in turn, causes massive vasodilation and bronchial constriction in the dog. This condition produces a sudden fall in blood pressure, resulting in respiratory depression, heart failure and death from shock, a syndrome which is similar to the effect caused by a bee sting or other toxic insect sting or bite. Some animals are hypersensitive to this toxin released by the heartworms and death occurs rapidly after treatment by the diethylcarbamazine. If the animal is not hypersensitive to the toxin and is not unduly affected by the massive vasodilation and bronchial constriction caused by the acetylcholine it will recover, since the adult heartworms are destroyed by contact with the diethylcarbamazine. I have noted that dogs which exhibit this hypersensitivity to the toxin released by the heartworms upon contact with the diethylcarbamazine have been saved by injections of adrenaline and atropine immediately after the reaction took place. Accordingly, the incorporation of anti-reactant medicines by injection, as well as in a capsule or tablet with the diethylcarbamazine on a time-release basis, will control the undesirable side effects resulting from massive vasodilation and bronchial constriction which causes weakening of the heart due to the toxin released by the adult heartworms and the acetylcholine produced by the body as a result of this toxin release. Specifically, it has been found that medications such as ephedrine, digoxin, dextroamphetamine sulfate and prednisone can be used as vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants, as well as anti-inflammatory agents, to counteract the effect of treating adult heartworms with diethylcarbamazine in a capsule or tablet dosage structure.
Accordingly, it is an object of this invention to provide a new and improved method and dosage structure for treating heartworms or filiariasis in dogs or other animals by initially pretreating the dogs by injection, tablets or capsules to effect vasoconstriction and bronchial dilation and subsequently introducting diethylcarbamazine into the blood stream for destroying the heart worms.
Another object of this invention is to provide a new and improved method for treating animals which are susceptible to filiariasis, by the steps of initially pretreating the animal with vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants and subsequently treating the adult heartworm condition with diethylcarbamazine.
Yet another object of the invention is to provide a method for treating dogs afflicted with filiariasis, which method includes the steps of administering ephedrine, digoxin, dextroamphetamine sulfate and prednisone to serve as vasoconstrictors, bronchial dilators, cardiac and sympathetic stimulants and anti-inflammatory agents, respectively, and subsequently treating the animal with diethylcarbamazine to kill the heartworms.
Yet another object of this invention is to provide a new and improved solid dosage structure for treating animals which are subject to filariasis, which solid dosage structure is characterized by one or more pretreatment layers of a vasoconstrictor, bronchial dilator and cardiac and sympathetic stimulant and an inner, time-release treatment layer of diethylcarbamazine for killing the infestation of heartworms.
A still further object of the invention is to provide a new and improved solid dosage structure for treating fillariasis, which dosage structure is characterized by an outer coating of a palatable material such as sugar or the like, an inner coating of mixed ingredients which include a vasoconstrictor, bronchial dilator, cardiac and sympathetic stimulant and anti-inflammatory medication such as, for example, ephedrine, digoxin, dextroamphetamine sulfate and prednisone and an inner core of diethylcarbamazine for killing the heartworms.
Another object of the invention is to provide a new and improved capsule of spansule dosage structure for treating filliariasis, which spansule is characterized by discrete pellets, beads or elements of a vasoconstrictor, bronchial dilator, cardiac and sympathetic stimulant and anti-inflammatory agent such as ephedrine, digoxin, and dextromphetamine sulfate and prednisone and a time releasae element or elements of diethylcarbamazine for killing the heartworms.
SUMMARY OF THE INVENTION
These and other objects of the invention are provided in a new and improved method and various dosage structures for treating filiariasis in animals such as dogs, which method includes the steps of preventatively treating the animal by injection, tablets or capsules with selected vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants as well as an anti-inflammatory agent and subsequently therapeutically treating the animal with diethylcarbamazine. In a preferred embodiment of the invention, the vasoconstrictors, bronchial dilators, cardiac and sympathetic stimulants and anti-inflammatory agent include ephedrine, digoxin, dextroamphetamine sulfate and prednisone, which are incorporated in a tablet or capsule dosage structure as an outer layer, or shaped into discrete pellets, with a time-release inner layer, core or element(s) of diethylcarbamazine, to both pretreat and therapeutically treat the animal. Alternatively, the vasconstrictors, bronchial dilators, cardiac and sympathetic stimulants and anti-inflammatory agent can be injected and/or oraly introduced into the animal and the diethylcarbamazine subsequently introduced after elapse of a predetermined time interval.
BRIEF DESCRIPTOIN OF THE DRAWING
The invention will be better understood by reference to the accompanying drawing wherein:
FIG. 1 is a sperically-shaped solid dosage structure having a sugar outer coating, a pretreatment layer inside the sugar coating and a diethylcarbamazine core;
FIG. 2 is a spherically-shaped solid dosage structure characterized by a sugar outer coating, discreet layers of vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants and a diethylcarbamazine core; and
FIG. 3 is an elongated capsule containing discrete vasoconstricting, bronchial dilating and cardiac and sympathetic stimulating elements or pellets and time-release diethylcarbamazine structures or elements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawing, in a preferred embodiment of the invention a mixed ingredient solid dosage structure is generally illustrated by reference numeral 1. The mixed ingredient solid dosage structure 1 includes a sugar coating 2 of selected thickness, a pretreatment layer 3 which consists of mixed vasoconstrictors, bronchial dilators and cardiac and sympathetic ingredients such as prednisone, ephedrine, digoxin and dextroamphetamine sulfate. A time-release layer 4 of gelatin of selected thickness is provided adjacent and interiorally of the pretreatment layer 3 and shields of diethylcarbamazine core 5. Accordingly, it will be appreciated by those skilled in the art that when the mixed ingredient solid dosage structure 1 is administered to an animal such as a dog for the treatment of filiariasis, the animal readily ingests the mixed ingredients solid dosage structure 1 because of the sweet taste of the sugar coating 2. When the mixed ingredient solid dosage structure 1 is ingested, the sugar coating 2 rapidly dissolves and the pretreatment layer 3 is exposed, to release a mixture of selected vasoconstrictors, bronchial dilators and/or cardiac and sympathetic stimulants such as prednisone, ephedrine, digoxin and dextroamphetamine sulfate, into the dog's system. These drugs are designed to counteract massive vasodilation and bronchial constriction and the resulting cardiac weakening which results from the rapid lowering of blood pressure when the diethylcarbamazine core 5 is later dissolved and attacks the infestation of heartworms in the dog. Accordingly, the time-release layer 4 is designed to allow the respective pretreatment ingredients provided in the pretreatment layer 3 to hvae the desired biological effect on the dog prior to release of the diethylcarbamazine core element into the dog's system. When this desired preventative treatment has occurred and the diethylcarbamazine core is dissolved into the dog's system, release of acetylcholine from the body, which results from release of toxin from the heartworms upon contacting the diethylcarbamazine material, fails to produce the massive vasodilation and bronchial constriction which can be fatal to the dog and the dog has a much greater chance of recovery.
Referring now to FIG. 2 of the drawing in another preferred embodiment of the invention a separate ingredient solid dosage structure 6 is illustrated, with a sugar coating 2, a prednisone layer 7, an ephedrine layer 8, a digoxin layer 9 and a dextroamphetamine sulfate layer 10, provided as discrete layers in the separate ingredient solid dosage structure 6. As in the case of the mixed ingredient solid dosage structure 1, a time-release layer 4 is provided between the diethylcarbamazine core 5 and the dextroamphetamine sulfate layer 10, in order to shield the animal's system from the effects of acetylcholine resulting from the toxin liberated from the heartworms upon contact with the diethylcarbamazine core, until the preventative ingredients have had an opportunity to cause vasoconstriction and bronchial dilation. It will be appreciated by those skilled in the art that the relative depth and/or position of the prednisone layer 7, ephedrine layer 8, digoxin layer 9 and the dextroamphetamine sulfate layer 10 in the separate ingredient solid dosage structure 6 is a matter of choice, depending upon the relative order in which the respective ingredients are to be used to prepare the dog's system for attack by the acetylcholine responsive to liberation of the heartworm toxin.
Referring now to FIG. 3 of the drawing in another preferred embodiment of the invention both the pretreatment and therapeutic ingredients for eliminating the heartworms are provided in a conventional gelatin capsule 11a, as a spansule dosage structure 11. Encapsulated inside the capsule 11a are discrete pretreatment prednisone pellets 12, ephedrine pellets 13, digoxin pellets 14 and dextroamphetamine sulfate pellets 15, as well as time-release pellets 16 of the therapeutic drug diethylcarbamazine. In a most preferred embodiment of this aspect of the invention, the diethylcarbamazine pellets 16 are coated with a layer of gelatin or other time-release material (not illustrated) to retard premature spreading of the diethylcarbamazine through a dog's system before the prednisone pellets 12, ephedrine pellets 13, digoxin pellets 14 and dextroamphetemine sulfate pellets 16 are absorbed in the blood.
It has been found that while the prednisone, ephedrine, digoxin and dextroamphetamine sulfate can be administered separately by injection or orally in tablet or capsule form prior to treatment with diethylcarbamazine, it is preferred to supply these ingredients in a solid dosage structure or a "spansule", as illustrated in FIGS. 1-3 and described above. However, whether the ingredients are administered separately in the mixed ingredient solid dosage structure 1, separate ingredient solid dosage structure 6 or spansule dosage structure 11, a preferred dosage is about 3 milligrams of prednisone, about 3/8 of a grain of ephedrine, about 0.25 milligrams of digoxin and about 2 to about 4 milligrams of dextroamphetamine sulfate, for a dog of average size, weighing about 40 pounds. It will, however, be appreciated by those skilled in the art that this dosage will vary, depending upon the size of the dog to be treated. In a most preferred embodiment of the invention the dosage is repeated twice daily at 8-hour intervals, for fourteen days. Furthermore, in each case where either the mixed ingredient solid dosage structure 1, the separate ingredient solid dosage structure 6 or the spansule dosage structure 11 is utilized, a 400 milligram dosage of diethylcarbamazine in each dosage structure, or 800 milligrams per day therapeutic treatment for a forty to sixty pound dog is indicated. The treatment is effective and inexpensive. The size and shape of the mixed ingredient solid dosage structure 1, separate ingredient solid dosage structure 6 and spansule dosage structure 11 can be varied, depending upon the relative dosages of the ingredients thereof which are necessary to treat dogs of various size according to the knowledge of those skilled in the art and the teachings of this invention. For example, both the mixed ingredient solid dosage structure 1 and the separate ingredient solid dosage structure 6 can be constructed in tablet form, as desired, according to the knowledge of those skilled in the art.
Generally, the time release layer 4 in the mixed ingredient solid dosage structure 1 and the separate ingredient solid dosage structure 6 and the time-release coating (not illustrated) on the diethylcarbamazine pellets 16 in the spansule dosage structure 11 can be designed to allow the anti-reactant medication to reach the bloodstream some 15-30 minutes before the diethylcarbamazine element is introduced into the system. This time delay insures that the reaction to the filaria toxin will not cause the massive vasodilation and bronchial constriction which would normally occur due to toxin release and acetylcholine secretion if the anti-reactant medication had not been used. While gelatin is a preferred material of choice for both the time-release layer 4 and construction of the capsule 11a, as wells the coating (not illustrated) provided on the time release pellets 16, other time-release coatings can be used in these applications, according to the knowledge of those skilled in the art.
It will be recognized that additional treatment may be necessary for some dogs, particularly under circumstances of severe emaciation caused by the filiariasis. Dogs in advanced stages of organic damage resulting from filaria infestations will not be aided by merely destroying the adult heartworms alone. Accordingly, the treatment is not recommended for dogs with severe liver disfunction syndrome, ascites, anemia, or other severely debilitated animals suffering from obvious organic damage. Such dogs are normally treated symtomatically before any heartworm treatment is used, including the treatment of this invention. Therefore, the primary advantage of the method or technique of treatment and the solid and spansule dosage structures of this invention lies in the fact that the inventive technique and various dosage structures safely kill all adult heartworms and all immature adult heartworms when used as noted herein. Accordingly, the method and dosage structure of this invention afford an economical and practical approach to controlling, as well as treating, adult and immature adult heartworms in reasonably healthy dogs not showing evidence of organic damage of a terminal nature.
The invention will be better understood by reference to the following examples:
Example 1
A 50 pound, 6-year old female black and tan Coonhound was observed to have a bad cough and was noted to be in poor condition, short of breath and emaciated, with micro-filaria present in the blood sample. The dog was treated by administering 400 milligrams of diethylcarbamazine twice daily on an 8-hour schedule after pretreating the dog with 0.25 milligrams of digoxin, 3/8 of a grain of ephedrine and 5 milligrams of prednisone thirty minutes prior to dosing on the diethylcarbamazine. A 14-day treatment was administered without observation of any adverse reaction due to toxin release by the treated heartworms. The dog made rapid progress back to normal health and showed dramatic improvement in breathing and stamina over a six week period of time after treatment. Blood samples checked negative for microfilaria at six weeks after adulut treatment of the heartworms using this method.
Example 2
A 50-pound, five-year old male Foxhound was observed to have a chronic cough, weight loss and tested positive on direct smear for microfilaria. Adult infestation of heartworms was diagnosed. 0.25 milligrams of digoxin, 3/8 of a grain of ephedrine and 5 milligrams of prednisone was administered thirty minutes prior to administering 400 milligrams of diethylcarbamazine orally at a rate of 400 milligrams twice daily. Treatment was carried out for fourteen days and six weeks later the dog was observed to be in good physical condition. Very small numbers of microfilaria were found in the blood during examination and the general condition of the dog was noted to be excellent.
Example 3
A 28 pound, 8-year old spayed female mixed-breed dog was observed to have a bad cough and a wheezing sound on respiration. The dog was given a premedicated treatment of 0.15 milligrams of digoxin, 1/8 grain of ephedrine and 3 milligrams of prednisone by mouth in tablet form, before each dose of diethylcarbamazine of 300 milligrams, twice daily, on a 8-hour schedule was administered. No adverse reaction was observed. The cough was observed to be greatly improved in three weeks and six weeks later the cough was gone. However, it was recommended to continue giving the dog 0.15 milligrams of digoxin for several months on a daily basis, since some cardiac insufficiency was observed. The wheezing in the lungs was absent after six weeks and the dog appeared to be near normal.
Example 4
A 60 pound, 6-year old male Pointer was observed to be very athletic but had a violent cough after 30 minutes in the field. The dog would stagger and finally fall over and lie down. Pulmonary arterial blockage by heartworms was tentatively diagnosed and a blood smear tested positive for microfilaria in large numbers. A premedication treatment of 0.25 milligrams digoxin, 3/8 of a grain of ephedrine and 5 milligrams of prednisone was administered thirty minutes prior to dosing on 400 milligrams of diethylcarbamazine, twice daily on an 8-hour schedule for fourteen days. The dog's improvement was observed to be dramatic and six weeks later he was checked and found to be in excellent condition.
Example 5
An 18-pound, 10-year old female mixed-breed dog was observed to have breathing problems, with a chronic cough. Multiple microfilaria were found in blood tests and heartworm infestation was diagnosed. A predmedication treatment of 0.15 milligrams of digoxin, 3 milligrams of prednisone and 1/8 of a grain of ephedrine for fourteen days was administered, along with following therapeutic treatment for 200 milligrams of diethylcarbamazine on an 8-hour schedule, twice daily. The dog had no apparent side effects and breathing and cough were much improved upon observation after treatment. The dog's appetite returned rapidly and recovery was observed to be complete.
The process and dosage structure of this invention facilitates an effective treatment of dogs for filariasis in a safe and effective manner by neutralizing the acetylcholine produced by the body resulting from diethylcarbamazine-induced toxin produced by the heartworms before the acetylcholine can adversely affect the dog. The treatment is effective using drugs which are well known as vasoconstrictors, bronchial dilators and cardiac and sympathetic stimulants, thus employing an anti-reactant feature prior to therapeutic treatment in order to render the old and well known diethylcarbamazine medicine safe and effective for its intended use.
It will be appreciated by those skilled in the art that while vasoconstricting, bronchial dilating and cardiac and sympathetic stimulants as well as anti-inflammatory agents may all be used to brace a dog's system for attack by acetylcholine secretions, any combination of these drugs can be used as deemed necessary by those skilled in the art, for treatment of a specific dog in question. Furthermore, known vasoconstrictors, bronchial dilators, cardiac and sympathetic stimulants and anti-inflammatory agents other than prednisone, ephedrine, digoxin, and dextroamphetamine sulfate can be used to pretreat the animals in preparation for therapeutic dosages of the diethylcarbamazine, also according to the knowledge of those skilled in the art. For example, while prednisone is a known vasoconstricting and bronchial dilating steroid which also has good anti-inflammatory properties, other steroids such as cortesone can also be used in the method and medication of this invention. Furthermore, the digoxin serves not only as a mild vasoconstrictor and bronchial dilator, but also operates primarily as a heart muscle stimulant to elevate the blood pressure in dogs treated according to the method and medication of this invention. Other known medications can also be used to achieve this goal of cardiac muscle stimulation according to the knowledge of those skilled in the art. Ephedrine has been found without equal in my experiments as a vasoconstricting and bronchial dilating medication. Accordingly, by experimentation, I have found that complete and effective pretreatment of a dog for filiariasis can be effected using the drugs prednisone, ephedrine and digoxin. The addition of dextroamphetamine sulfate, another known vasoconstricting and bronchial dilating drug, also serves to help stimulate the central nervous system in a dog in order to counteract the depressant effect of the acetylcholine, as well as to aid the vasoconstricting and bronchial dilating functions. Under circumstances where the pretreatment medication can be administered by injection, it has been found that adrenalin and prednisone, as well as atropine can be used to good advantage. Dextroamphetamine sulfate can also be injected in a liquid medium to pretreat a dog prior to administraton of the diethycarbamazine.
While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such medications which may fall within the spirit and scope of the invention.
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A medication and method for treating heartworms in dogs, which medication includes a time release capsule or tablet dosage structure which is characterized either by discrete elements (capsule) or an outer layer or layers (tablet) of vasoconstricting and bronchial dilating medications and an inner, time-released layer or pellets of diethylcarbamazine. The vasoconstrictors and bronchial dilators are designed to counteract life-threatening vasodilation and bronchial constriction resulting from the release of acetylcholine by the dog when the heartworms are attacked by the diethylcarbamazine. The solid dosage structure can be constructed by layering such vasoconstrictors and bronchial dilators as prednisone, ephedrine, digoxin and dextroamphetamine sulfate in separate layers or combining these ingredients in a single layer separated from the diethylcarbamazine by a time-release substance such as gelatin. The capsule dosage structure includes discrete beads or elements of the medications in a capsule containing a time release, therapeutic dosage of the diethylcarbamazine. Alternatively, the vasoconstrictors and bronchial dilator medications can be injected or administered orally prior to treatment with the diethylcarbamazine according to the method of this invention.
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BACKGROUND OF THE INVENTION
The invention relates to improvements in methods of and in apparatus for laminating plastic foils. The invention also relates to laminates which are obtained in accordance with the improved method and by resorting to the improved apparatus. More particularly, the invention relates to improvements in methods of and in apparatus for making laminates from stretched and unstretched plastic foils.
It is already known to make laminates wherein a longitudinally (monoaxially) stretched first foil is bonded to an unstretched second foil. The thus obtained laminate exhibits highly satisfactory strength characteristics which are attributable to the presence of the stretched foil and are effective in the direction of stretch, as well as highly satisfactory strength characteristics in a direction transversely of the laminate. Moreover, the laminate exhibits a desirable pronounced rigidity. In accordance with heretofore known proposals, a laminate which consists of or includes a stretched and an unstretched foil is obtained by resorting to an adhesive as a means for bonding the foils to each other. The temperature at which the bonding step takes place must be below the crystallite melting point of the stretched foil in order to ensure that the beneficial results of stretching at a temperature below such point are not lost in the course of the bonding operation with an adhesive.
A drawback of the just outlined conventional methods is that the adhesive contributes significantly to the cost of making the laminate. In addition, recycling of the laminate presents problems due to the presence of adhesive therein.
Attempts to overcome the drawbacks of a laminate wherein a stretched foil is bonded to an unstretched foil by means of an adhesive include extrusion of a second foil directly against one side of an unstretched foil. However, the resulting laminate does not exhibit the characteristics of a laminate which contains a stretched foil and an unstretched foil. If a layer of plastic material is extruded directly against a stretched foil, the extruding operation must be carried out at a temperature which is too high so that the part of the laminate which includes the stretched foil no longer exhibits the advantages of a stretched foil.
The article by Breitbach et al. on pages 356-368 of "Kunststoffe" (Volume 61, 1971, H. 5) describes the advantages of laminates which consist of plastic foils. The authors discuss lamination with adhesive, so-called wax lamination and so-called hot lamination. The article does not propose to make laminates which consist of or contain stretched and unstretched plastic foils.
Published European patent application No. 0 122 495 of Koebisu et al. discloses a laminated film of an olefin polymer. The product of Koebisu et al. comprises a biaxially oriented polypropylene film and at least one olefin polymer film which is laminated to at least one surface of the biaxially oriented film. The inventors propose to bond the films with an adhesive or to resort to coextrusion.
Published European patent application No. 0 052 262 of Stegmeier et al. discloses a biaxially stretched polypropylene foil at least one side of which is coated with a layer of polyethylene. The application of the polyethylene layer or layers involves coextrusion, hot lamination or fusion coating.
German Auslegeschrift No. 1 294 005 of Kahn et al. proposes that lamination of foils be followed by stretching of the resulting laminate.
German Auslegeschrift No. 28 15 855 of Buzio et al. discloses a laminate consisting of a biaxially oriented polypropylene foil and a non-oriented polypropylene foil. The two foils are bonded to each other by a layer of adhesive.
OBJECTS OF THE INVENTION
An object of the invention is to provide a novel and improved method of making laminates which consist of or contain plastic foils but need not employ any adhesive substances.
Another object of the invention is to provide a method of making a laminate which can be readily recycled.
A further object of the invention is to provide a method which can be practiced for the making of laminates exhibiting any one of a variety of desirable characteristics including pronounced resistance to longitudinal and/or transverse stretching, optimum stiffness and others.
An additional object of the invention is to provide a simple and inexpensive method of making laminates from plural plastic foils including at least one stretched foil.
Still another object of the invention is to provide a simple and inexpensive apparatus for the practice of the above outlined method.
Another object of the invention is to provide the apparatus with novel and improved means for stretching and otherwise treating at least one of several foils which are to be assembled into a laminate.
A further object of the invention is to provide an apparatus which can be rapidly converted for the making of different types of laminates.
An additional object of the invention is to provide an apparatus which can produced laminates in an economical way and satisfies the rules and regulations of authorities in charge of ecology, particularly of disposal of wrapping materials and the like.
A further object of the invention is to provide a novel and improved laminate by resorting to the above outlined method.
Another object of the invention is to provide a novel and improved laminate by utilizing the above outlined apparatus.
SUMMARY OF THE INVENTION
One feature of the present invention resides in the provision of a method of making a laminate from a plurality of foils. The method comprises the steps of introducing an unstretched first foil into and moving the first foil in a predetermined direction along an elongated first path, preheating the moving first foil in a first portion of the first path, stretching the moving preheated first foil in the predetermined direction in a second portion of the first path downstream of the first portion, moving the stretched first foil at a predetermined speed, tempering (e.g., heating) the stretched first foil in a third portion of the first path downstream of the second portion, introducing an unstretched second foil into and moving the unstretched second foil at the predetermined speed along a second elongated path which merges into the first path downstream of the second portion of the first path, pressing the first and second foils against each other in the first path in the presence of heat (e.g., in the presence of heat which is generated as a result of the stretching or tempering step), and continuously moving the thus obtained laminate along the first path.
Each of the first and second foils has a first side and a second side, and the pressing step includes urging the first sides of the first and second foils against each other. At least that layer of each of the first and second foils which is adjacent the respective first side consists of one and the same material or of two compatible materials, namely of two materials which can be bonded to each other as a result of the application of heat and pressure.
The method can further comprise the step of heating the second foil in the second path, i.e., prior to the pressing step.
Each moving step (i.e., the step of moving the first foil, the step of moving the second foil and the step of moving the laminate) preferably comprises continuously moving the respective foil and the laminate.
The pressing step can be carried out in the third portion of the first path, and the method can further comprise the step of cooling the laminate in a fourth portion of the first path downstream of the third portion.
The foils can be made, in their entirety, of one and the same plastic material, such as polyethylene or a copolymer of polyethylene.
The method can also comprise the step of maintaining the first foil in stretched condition downstream of the second portion of the first path, particularly at least during movement along and downstream of the third portion of the first path.
The pressing step preferably includes urging the first and second foils against each other in the presence of heat which matches or is only slightly less than the stretching temperature of the first foil.
Another feature of the invention resides in the provision of an apparatus for making a laminate from a stretched first foil in an unstretched second foil. The apparatus comprises means for introducing the first foil in unstretched condition into and for moving the first foil in a predetermined direction along an elongated first path, means for preheating the moving first foil in a first portion of the first path, means for stretching the preheated moving first foil in the predetermined direction in a second portion of the first path downstream of the first portion, means for tempering the stretched first foil in a third portion of the first path downstream of the second portion, means for introducing the unstretched second foil into and for moving the second foil along a second elongated path which merges into the first path downstream of the second portion of the first path, and means for pressing the stretched first foil and the unstretched second foil against each other in the first path in the presence of heat.
The preheating, stretching and tempering means can form part of the means for moving the first foil along the first path, and the tempering means can form part of the pressing means. Such tempering means can be immediately or closely adjacent the stretching means.
The apparatus can further comprise means for heating the unstretched second foil in the second path. Such heating means can comprise a roller and means for training the second foil over the roller through an angle of at least 180°, for example, through an angle of approximately 270°. Alternatively, the means for heating the second foil can comprise a plurality of rollers and means for training successive increments of the moving second foil around the rollers so that the thus trained or deformed increments of the second foil are substantially S-shaped.
The first and second foils of the laminate have abutting first sides and non-abutting second sides. The means for heating the second foil preferably includes a heating element (e.g., a roller) which contacts the first side of the second roil while the second foil moves along the second path. The pressing means can immediately follow the heating element of the means for heating the second foil so that successive increments of the first side of the second foil are contacted first by the heating element and thereupon by the first side of the first foil at the pressing station.
The apparatus can further comprise means for influencing the surface finish of the first foil between the stretching means and the pressing means. Such influencing means can comprise at least one smoothing roller which biases the first foil against the stretching means, against the tempering means and/or against the pressing means.
Still another feature of the invention resides in the provision of an elongated laminate which comprises an unstretched foil and a longitudinally stretched foil. The foils have abutting layers of identical materials or of materials which can be bonded to each other in response to the application of heat and pressure. At least one of the materials can be polyethylene or a copolymer of polyethylene.
The laminate can further comprise a third foil which adheres to one of the stretched and unstretched foils. The one foil is then disposed between the third foil and the other of the stretched and unstretched foils. It is preferred to bond the third foil to the unstretched foil.
Each of the stretched and unstretched foils can be made of polyethylene. Alternatively, each of the stretched and unstretched foils can be made of a material which is selected from the group consisting of polyethylene and copolymers of polyethylene.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single Figure of the drawing is a schematic elevational view of an apparatus which embodies one form of the invention and can be utilized for the making of twin-layer or three-layer laminates wherein one of the layers is on its way toward the laminating station.
DESCRIPTION OF PREFERRED EMBODIMENTS
The apparatus 1 which is shown in the drawing serves to form a laminate 13 from an initially unstretched first plastic foil 2 and an unstretched second foil 3. The first foil 2 is supplied from a suitable source (e.g., a reel or an extruder) in the direction of arrow A to enter an elongated path which is defined by a plurality of rollers including a first roller 5 serving as a means for preheating the foil 2. The roller 5 moves successive (preheated) increments of the foil 2 into the range of four rollers 6 which together constitute a stretching unit 4 serving to monoaxially stretch the foil 2 on its way toward a tempering roller 8. The speed of the two lower rollers 6 exceeds the speed of the two upper rollers 6 so that successive increments of the continuously moving foil 2 are stretched at 7, i.e., close to and upstream of the tempering roller 8. The means for moving the foil 2 along its path in the direction of arrow A further comprises advancing rollers 213 which are located downstream of the tempering roller 8 and serve to draw the laminate 13 through a suitable cooling unit 113 wherein the laminate is cooled by air, by another gas or in any other suitable way.
The means for pressing the stretched foil 2 against the unstretched foil 3 comprises the tempering roller 8 and a further roller 9 which defines a portion of an elongated (second) path for the foil 3. The latter is drawn from a suitable source (e.g., a supply reel or an extruder) and is moved in the direction of arrow B on its way toward the nip of the rollers 8, 9 at the pressing or laminating station. The speed of the foil 3 matches the speed of the foil 2 downstream of the stretching unit 4, and the foil 3 is heated by a roller 11 upstream of the pressing station including the rollers 8 and 9. The roller 9 is backed up by an idler roller 10 in order to prevent uncontrolled deformation of the roller 9 as a result of the application of pressure to the foils 2 and 3 at the nip of the rollers 8 and 9.
Though the drawing shows a single preheating roller 5 for the foil 2, the latter can be preheated by two or more successive rollers and/or in any other suitable way.
A smoothing roller 12 can be provided immediately downstream of the stretching unit 4 to influence the surface or surfaces of the foil 2 ahead of the pressing or laminating station. The illustrated smoothing roller 12 cooperates with the tempering roller 8.
The rollers 9, 10 are preferably adjustable radially of the tempering roller 8. The adjusting means is not shown in the drawing. Such adjusting means is designed to cause the roller 9 to apply a force which suffices to ensure that the foils 2 and 3 are converted into the laminate 13 as a result of the application of heat and pressure during advancement of successive increments of these foils in the direction of arrow A and at the same speed.
The apparatus 1 further comprises deflecting rollers 103, 203 which flank the heating roller 11 and ensure that the continuously moving foil 3 is trained over the roller 11 along an angle of at least 180°, preferably close to 270°. If the deflecting roller 103 is heated (e.g., by the device which heats the roller 11), i.e., if the means for heating the foil 3 comprises a plurality of rotary elements, the rollers 103 and 203 cooperate to ensure that each increment of the foil 4 which is being heated by the rollers 103, 11 is caused to assume the shape of a letter S or a similar shape.
It will be noted that the roller 11 contacts that side or surface (3a) of the foil 3 which is laminated to the side or surface 2a of the foil 2 (as a result of the application of heat and pressure) during advancement through the nip of the rollers 8 and 9. Thus, the side or surface 3a of the foil 3 is not contacted by any parts during advancement of successive increments of such side or surface from the periphery of the roller 11 into engagement with the side or surface 2a of the foil 2. The just discussed mode of assembling the improved apparatus 1 is desirable and advantageous because the roller 11 can heat the foil 3 (or can complete the heating of the foil 3) ahead of the pressing or laminating station to a temperature which ensures that the temperature of those increments of the foil 3 which reach the surface 2a is best suited for the establishment of a reliable bond between the foils 2 and 3.
The smoothing roller 12 constitutes an optional but desirable and advantageous feature of the apparatus 1. This roller ensures that the freshly stretched increments of the foil 2 lie flat against the peripheral surface of the roller 8 on their way toward the pressing or laminating station which is defined by the rollers 8 and 9.
The foil 2 is or can be made of a material (e.g., polyethylene) which is preferably identical with the material of the foil 3. At the very least, that layer or stratum of the foil 3 which is adjacent the side or surface 3a is or can be made of the same material as the layer or stratum of the foil 2 which is immediately adjacent the surface 2a. However, it is also possible to make the foils 2, 3 or the aforementioned layers or strata of different materials, as long as such materials are sufficiently compatible to enable the films 2, 3 to form a laminate 13 without the need for an adhesive which would contribute to the cost of the foil 13 and would also contribute to complexity of recycling of the foil. For example, the films 2, 3 and/or their layers which are adjacent to the sides 2a, 3a can be made of a material which includes polyethylene and copolymers of polyethylene.
As mentioned above, the pressing or laminating station is preferably close or very close to the stretching unit 4 so that heat which is required for the laminating step can constitute the heat or include the heat which is needed for stretching of the film 2 in the unit 4.
The apparatus 1 which is shown in the drawing can be readily converted for the making of a laminate with three layers. For example, a third foil 14 can be supplied in the direction of arrow C to be laminated to the side or surface 3b of the foil 3 so that the foil 3 is then located between the foils 2 and 14 of the thus obtained three-layer laminate. The reference character 114 denotes a combined pressing and heating roller which can cooperate with the roller 11 to bond the foil 14 to the side 3b of the foil 3. The material of the third foil 14 may but need not be the same as the material of the foil 2 and/or 3. The method of making a three-layer laminate is simplified if all three foils consist of the same material (e.g., polyethylene or a copolymer of polyethylene). Moreover, such method of making the three-layer laminate simplifies recycling of the product.
The cooling unit 113 can be of any conventional design. For example, this unit can be similar or analogous to those which are customarily employed in connection with the cooling of stretched foils.
The means (11 or 103, 11) for heating the foil 3 ahead of the pressing or laminating station (nip of the rollers 8 and 9) is optional but desirable because it contributes to the output of the apparatus 1. The arrangement is preferably such that the temperature of the foil 3 and/or 2 at the pressing or laminating station at most matches but is preferably slightly less than the stretching temperature of the foil 2. The temperature of the foil 2 in the nip of the rollers 8 and 9 can match the stretching temperature, i.e., it is not necessary to heat the foil 2 (between 4 and 9) to a temperature which is higher than the temperature of those increments of the foil 2 which have undergone or are undergoing monoaxial stretching in the unit 4.
The speed of movement of the foil 3 must match the speed of movement of the foil 2 only at the exact locus of the pressing or laminating station, i.e., in the nip of the rollers 8 and 9.
An important advantage of the improved method, apparatus and laminate is that the temperature at the laminating station is not so high that it would affect the stretched foil 2, i.e., that it would prevent the laminate 13 from exhibiting those desirable characteristics which are attributable to monoaxial stretching of one of its layers. Thus, all that is necessary is to maintain at the nip of the rollers 8, 9 a temperature which at most matches the stretching temperature for the foil 2. Another advantage of the absence of any need to heat the foils 2 and 3 to a temperature above the stretching temperature for the foil 2 is that the operation of the apparatus is economical.
An additional advantage of the improved method and apparatus is that the unstretched foil 3 is or can be heated ahead of the laminating station. This renders it possible to advance the foils at a higher speed, not only toward and through but also beyond the nip of the rollers 8 and 9.
The cooling unit 113 replaces that cooling unit which is provided downstream of the stretching station whenever a plastic foil is treated to undergo monoaxial or biaxial stretching. Thus, the number of cooling units need not be increased solely because the improved method involves the making of a laminate which consists of or includes a monoaxially stretched foil and an unstretched foil. All this can be carried out without the need for an adhesive which would contribute to complexity and cost of the method and apparatus and would complicate recycling of the laminate.
A further advantage of the improved method and apparatus is that the laminate 13 can consist of a single material, i.e., the material of the foil 2 can be identical with the material of the foil 3. This contributes to lower cost of the method, apparatus and laminate. In addition, the strength of the laminate 13 is highly satisfactory in the longitudinal direction (i.e., in the direction of stretch of the foil 2). Still further, the tendency of the laminate to splice in the transverse direction is minimal due to the presence of the unstretched foil 3. In addition, it is simpler to recycle the laminate since its constituents consist of one and the same material.
The foil 2 can remain in stretched condition downstream of the unit 4. Thus, such stretching can be maintained while the freshly stretched increments of the foil 2 are on their way toward, through and even beyond the nip of the rollers 8 and 9. Maintaining the foil 2 in stretched condition at the laminating station ensures that the desirable effects of stretching in the unit 4 are not affected or lost in the course of the laminating step.
The laminating station can accommodate more than two rollers; for example, the means for urging the unstretched foil 3 against the stretched foil 2 (while the latter overlies the tempering roller 8) can comprise the roller 9 and at least one roller downstream of the roller 9.
The exact construction of the stretching unit 4 forms no part of the present invention. This unit can be any conventional unit wherein a moving plastic foil can be monoaxially stretched as a result of the application of heat and a stretching or tensioning force. The tempering roller 8 not only forms part of the pressing means but can further serve to maintain the temperature of the foil 2 at an optimum value in the region of the nip of the rollers 8, 9 as well as to assist the two lower rollers 6 to stretch successive increments of the foil 2 in the gap 7 between the upper rollers 6 and the lower rollers 6.
The simplicity of the improved apparatus 1 is attributable in part to the fact that such apparatus can be assembled of simple, compact and inexpensive components. Thus, a conventional stretching unit 4 and a conventional cooling unit 113 can be used in conjunction with a small number of rollers (5, 6, 12, 8 and 213) to define a path for and to move the foil 2 in the direction of arrow A toward, through and beyond the laminating station. The construction of that part of the apparatus which defines the path for the foil 3 is even simpler because the foil 3 need not be stretched ahead of the laminating station.
As mentioned above, the smoothing roller 12 is an optional feature of the improved apparatus. This roller contributes significantly to the quality of the laminate 13 in that it expels bubbles of entrapped gaseous fluid and/or other defects before the respective increments of the stretched foil 2 reach the laminating station.
The ratio of stretch of the foil 2 during treatment in the unit 4 can be between 1:1.5 and 1:10. If the foil 2 is made of polyethylene, the stretching temperature which is slightly below the crystallite melting temperature. The roller 9 can have an outer envelope of rubber or a like material which bears upon the side or surface 3b of the foil 3 at the laminating station. The axial length of the roller 9 can match the width of the foils 2, 3 or the width of the wider of these foils. The crystallite melting point of the foil 3 at the laminating station is lower than that of the foil 2; this results in the establishment of a desirable strong bond between the two foils. The method is economical because heat which is needed to ensure proper stretching in the unit 4 can be utilized to maintain the stretched foil 2 at an optimum temperature during bonding to the foil 3. The laminating operation can be carried out at a high speed, especially if the foil 3 is preheated.
It is further within the purview of the invention to affix a second unstretched foil 3 to the side or surface 2b of the stretched foil 2. Such laminating step can be carried out upstream or downstream of the roller 8.
EXAMPLE
The foil 2 was advanced toward the preheating roller 5 at a speed of 10 m/min. This foil had a thickness of 0.180 mm and consisted of high-density polyethylene (HDPE GF7740). The preheating roller 5 was maintained at a temperature of 110° C., the topmost roller 6 of the stretching unit 4 was maintained at a temperature of 122° C., the next three rollers 6 were maintained at a temperature of 126° C., and the tempering roller 8 was maintained at a temperature of 128° C. The stretching action of the unit 4 was such that the thickness of the foil 2 was reduced from 0.180 mm to 0.03 mm and the speed of the foil 2 was increased from 10 m/min. to 60 m/min. (the same as the speed of the laminate 13).
The foil 3 was delivered at a speed of 60 m/min. and had a thickness of 0.025 mm. This foil consisted of low density polyethylene (LDPE 2420H) and the roller 11 was maintained at a temperature of 60° C. The roller 10 was caused to apply to the roller 9 (and hence to the foils 2, 3 in the nip of the rollers 8 and 9) a pressure in the range of 3-5 bar. The laminate 13 had a thickness of 0.055 mm. The high-density polyethylene foil 2 can be replaced with linear low density polyethylene (LLDPE 2740) or with a copolymer of polyethylene with octene, butene or methylpentene (4-methylpentene-1). The low-density polyethylene foil 3 can be replaced with a copolymer of polyethylene with vinyl acetate, n-butyl acrylate or ethylene acrylic acid.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.
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An unstretched first plastic foil is laminated with a longitudinally stretched second plastic foil by the application of heat and pressure. The second foil is preheated, thereupon stretched and thereafter tempered prior to being laminated with the first foil which is heated prior to lamination. The laminating step can coincide with the tempering step and immediately follows the stretching step so that the laminating step can be carried out by utilizing heat which is required for stretching of the second foil. The material of the first foil is or can be identical with the material of the second foil; in any event, the two materials are sufficiently compatible to permit bonding of the unstretched foil to the stretched foil by the application of heat and pressure alone, i.e., without resorting to an adhesive.
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BACKGROUND ART
Thin films of crystalline material are important in many fields of science and technology. In semiconductor electronics, there is considerable research and development directed toward obtaining high-quality semiconductor films on insulating substrates, especially silicon (Si) on insulator films of silicon dioxide (SiO 2 ). Such structures are conventionally called SOI structures. One successful approach to SOI has been to form an SiO 2 layer on a single crystal Si wafer and then to deposit Si by chemical vapor deposition (CVD) on the SiO 2 insulator to form a polysilicon layer on the SiO 2 . Next, the polysilicon layer is formed into a single crystal layer by a number of techniques, such as Zone Melting and Recrystallization (ZMR). The top silicon film is then used to construct silicon devices which are isolated from each other by the underlying SiO 2 insulator.
Devices formed on SOI substrates are capable of superior performance compared to devices formed on bulk Si substrates. This results from the fully dielectric isolation produced by the underlying SiO 2 insulator of the SOI structure. Chief among the improved properties is higher packing density, higher radiation tolerance, faster switching speeds and CMOS circuits free of latch-up.
The present invention relates to improvements in the ZMR process used to form SOI substrates. In one version of the ZMR process, the recrystallization of the polysilicon layer is seeded or nucleated by the underlying single crystalline silicon wafer. A precursor structure comprising an insulating oxide layer is formed on the Si substrate. The oxide layer is then etched or scribed down to the underlying bulk single crystalline silicon wafer; thus exposing single crystalline Si seed regions. Then a polysilicon layer is deposited on the precursor structure. The polysilicon layer contacts the exposed Si seed regions. An optional capping layer is formed over the polysilicon.
In the past, the seed opening to the silicon wafer was in the shape of a relatively wide (about 10 microns or wider) continuous circular pattern about the periphery of the wafer near the edge. A stationary heater elevates the polysilicon layer to about 1000° C.-1300° C., i.e., near the melting point of the polysilicon. A moveable heating element is then translated past the structure to melt the polysilicon as the heating source moves along its path. Upon recrystallization, the polysilicon film is transformed to single or nearly single crystalline film seeded by the underlying bulk silicon wafer.
Several problems have been found with the above-described process. One is the serious tendency for the polysilicon melt to promote the mass flow of material away from the silicon seed, preventing uniform seeding. It would be very beneficial to avoid or reduce this tendency.
Another of the problems presently associated with the ZMR process is that the regions of polysilicon at which the seed openings are formed clearly cannot be used for device formation. Thus, portions of the wafer is wasted or non-productive. It would therefore be advantageous to minimize the area of such seed openings.
Also, without proper orientation of the seed openings, there is a substantial uncertainty in the seeding of the polysilicon as the melt traverses the structure. The polysilicon, which is not properly seeded during this uncertainty, also is not usable for device fabrication. Thus, it would be very advantageous to minimize this uncertainty in practice.
DISCLOSURE OF THE INVENTION
In one embodiment of the present invention, relatively small width discontinuous, generally semi-circular pattern of seed openings are formed in an SOI precursor structure. We have found that in a continuous circular seed opening pattern, the polysilicon melt has a tendency to evaporate from the silicon seed. This may be due to excessive heat buildup (thermal gradient) from the hot strip heater exposure to the large area, high thermal conductivity silicon material. With a discontinuous and reduced width pattern, the area of the surface exposed to the heater at any one time is minimized, counteracting thermal buildup. These two improvements decrease the material flow away from the seed. The discontinuous pattern is formed of a discontinuous sub-pattern of overlapping openings of various shape. The preferred orientation of the seed openings is [100] or about a 45° angle to the [110] Si wafer flat. It is noted that all other angle of seed openings will work, but this 45° angle to the [110] flat works best. The direction of seeding (direction the heater is scanned) is transverse this orientation. The preferred transverse width of the seed openings has been found to be about 5 microns, or less. The angle a between the sidewalls of the seed opening and the surface should preferably be greater than 90°, i.e., an obtuse angle, although other angles appear to work satisfactorily. Seed opening patterns may vary greatly provided certain basic parameters are present. Overlapping of patterns is preferred for successful seeding for reasonable length/width ratios.
A slightly modified semi-circular pattern of seed openings has been found to produce successful seeding. This configuration minimizes seed opening widths, and maximizes the useful area of the wafer, as compared, for example, to a continuous circular pattern. The [100] orientation of the seeding pattern combined with a [100] direction scan produces the most favorable seeding pattern.
The above and other features of the invention will now be explained in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of one-half of a Si wafer showing a first embodiment of the small seed width and discontinuous seed patterning of the invention.
FIG. 2 is an enlarged view of a portion 18 of FIG. 1.
FIG. 3 is an enlarged view of a portion 22 of region 22 of FIG. 2.
FIG. 4 is a cross sectional view of one of the seed openings 20 of FIG. 3.
FIG. 5 is a perspective view of a ZMR apparatus illustrating the process as applied to the seed patterned structure of the invention.
FIG. 6 is a plan view of a mask structure for a wafer showing various seed orientation.
FIG. 7 is an enlarged view of an alternate dotted seed pattern embodiment.
FIG. 8a-d is a schematicized cross-sectional view of an alternate edge bead seeding embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is shown one-half of a SOI structure 8 with small seed opening width showing the discontinuous generally semi-circular pattern 16 of shaped seed openings near the periphery 4 of the SOI structure 8. Pattern 16, in turn, is formed of a discontinuous sub-pattern 6 formed of shaped openings 20, as shown in FIG. 2, which is an enlarged region 18 of FIG. 1.
FIG. 3 is a further enlargement of region 22 of FIG. 2 showing in greater detail, the shape of the openings 20, which form the sub-patterns 6 which constitute the discontinuous generally semicircular pattern 16 of FIG. 1. The seed openings 20, as may be seen in FIG. 3, are generally rectangular in shape, with smooth curved ends. The pattern 16 is formed within about one-half inch from the wafer edge 4. The dashed seed opening pattern shape in FIG. 3 preferably has a length-to-width ratio of greater than 1 and, as may be seen in FIG. 2, each subpattern overlaps with the next adjacent pattern. This seeding arrangement provides a critical advantage over the continuous circular seed opening in terms of the heat exposure to the substrate bulk silicon 10.
As shown in FIG. 4, the angle a of the openings 20 is preferably greater than 90° for optimum seeding. The width W of the opening through the polysilicon 14 and SiO 2 insulator 12 to the bulk silicon substrate 10 is preferably less than or equal to five microns, although one micron to nine microns seed with openings have worked successfully.
As shown in FIG. 5, it is preferable to orient the seed opening pattern at a 45° angle to the [110] Si wafer flat 40 (the [100] seed orientation), since this orientation produces the least perturbation to the melt front. The [100] orientation is the most favorable seeding orientation with the scan of the heater also along the [100] line, as shown by the arrows in FIG. 5.
In the partially exploded view of FIG. 5, a sample SOI structure 8 is shown subjected to a thermal treatment by being disposed on a stationary lower strip heater 36, while the moveable upper strip heater 39 is mechanically translated past the SOI structure 8 in the direction of the arrows. The upper heater 39 is comprised of a central heater 30 disposed between fore and aft heaters 42 and 38, respectively. The upper heater 39 is coupled to a heat control unit 32 so that the temperature of the heaters 38 and 42 may be controlled separately from each other and from the other units. The lower heater is typically maintained at about 1100° C., while the upper aft heater 38 is set at about 1600° C. and the foremost heater 42 is set at about 1300° C. and the aft heater at 1400° C. Under these conditions, the top wafer surface first sees a temperature of about 1300° C. before encountering the elevated temperature of the main heater 30. A molten zone 34 is created in the polysilicon film. As the moveable heaters pass by the wafer, this molten zone is initially formed at the top right edge of the wafer and is seeded through the discontinuous openings in the pattern 16 and moves from right to left in the direction of the arrows of FIG. 5. As shown in FIG. 5, it is not necessary to complete the pattern throughout the whole circular periphery of the wafer, since once it passes the mid-point, the whole width of the wafer has been seeded by the underlying silicon substrate.
A number of seed opening orientation patterns have been tested, as shown in FIG. 6. Five such patterns, A-E, were formed in a SOI structure 8, having a [100] direction flat 40. In this case, the upper heater is scanned in the [100] direction, shown by the arrow labeled F. The pattern at A, which is 45° to the [100] flat proved to be the most successful orientation. The seed opening B, which is orientated at the [111] direction resulted in unsure seeding at the beginning, but after the molten zone traveled a distance, the polysilicon recrystallized oriented in the [100] plane. The seed opening pattern shown by arrow C slightly off the [100], also resulted in unsure seeding at first, but ultimately became oriented in the [100] direction. The seed opening shown by the arrow D likewise initially resulted in unsure crystallization, and then became oriented in the [110] direction and the seed opening pattern of pattern E, while initially resulting in unsure crystallization, ended up oriented in the [210] direction.
An alternative sub-pattern of seed openings 6' is shown enlarged in FIG. 7. This sub-pattern consists of circular openings, or dots, 20'. This pattern has also been found to form successful seeding, provided the diameter of the openings and the angle of the sidewalls, down to the silicon wafer, are within the parameters referenced above.
An alternate seeding process, edge bead seeding, relies on use of a ring heater to maintain a constant thermal gradient even with material exposure to the hot strip heater. In this case, the seed width opening is not critical. This process, called edge bead seeding, allows seeding at the very edge of the wafer where there is a large heat sink. With this process, the limitations described earlier, may be avoided.
This alternate seeding process shall now be described in connection with FIGS. 8a-c. In this method, a seed opening 19 is created at the edge of the wafer 10, rather than the usual printed seed pattern within the perimeter. The starting structure 100 (FIG. 8a) consists of single crystalline Si wafer 10', and an SiO 2 insulator film 12'. A resist layer 15 is formed on the insulator 12'. The new method consists of squirting or spraying a photoresist solvent on the underside of the SOI precursor structure 100 which is spinning on a chuck (not shown). The centrifugal force associated with the spinning causes the resist to bead up and flow to the outside edge of the wafer and curl up around to the surface edge once the spin speed and amount of solvent is adjusted. Using this method, about 1/4 inch of photoresist 15 is removed from the top surface edge (FIG. 8b) leaving a peripheral edge 17 of SiO 2 12' exposed. The exposed SiO 2 12' is then removed by a suitable etchant, leaving an exposed peripheral seed edge 19' (FIG. 8c). Then, when the polysilicon layer 14' is deposited on the SiO 2 12', a peripheral edge 21' of the polysilicon layer 14' is in contact with a peripheral edge of the Si wafer 10' (FIG. 8d). The advantage is a seeding process simplification. No projection aligner or automated development process is required for the seeding step of the SOI structure fabrication. The seed is thus at the very edge of the surface and maximizes the usable SOI area per wafer and eliminates several conventional processing steps to achieve the seed.
Equivalents
This completes the description of the preferred embodiments of the invention. Note that while the term "film" or "layer" has been used herein to denote a thin body of material covering a substrate, such terms are also intended to cover portions or regions of a substrate. Furthermore, while SiO 2 has been used as the insulator in the examples given, other insulators, such as silicon nitride or oxynitride, are contemplated for use in the process of the invention. While the invention has been particularly shown and described with reference to such embodiments, it should be understood that those skilled in the art would be capable of devising various changes in form and detail without departing from the spirit scope of the invention.
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An improved method of forming seed openings for zone-melting and recrystallization of polysilicon film on an insulator over silicon (SOI) is described. This method comprises forming a narrow discontinuous pattern of seed openings formed by an overlapping sub-pattern of discontinuous shaped openings. Alternatively, in an edge bead seed embodiment, a resist is removed from an SOI precursor structure, comprising an insulator on an Si wafer, thus exposing the peripheral edge of the insulator. The exposed insulator is then also removed to provide a peripheral edge seed opening to the underlying Si wafer.
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BACKGROUND OF THE INVENTION
The invention generally concerns tactical gear, but specifically a belt buckle for police, military or tactical personnel, the belt buckle being of low profile (width) so as to minimize the length of belt span which it occupies.
Belt buckles have been provided in a variety of forms. Police and tactical personnel normally wear a heavy, somewhat wide belt on which may be carried one or more weapons, ammunition, communication gear or other equipment. The typical belt buckle is fairly heavy duty and can occupy a considerable amount of space in the circumference of the belt span, especially at front, limiting space for equipment carried on the belt. An objective of the current invention is to minimize the lateral width of belt span occupied by a belt buckle while providing a strong, heavy duty buckle that is also aesthetically attractive.
The prior art contains several buckles or clasps relevant to the present invention. These include U.S. Pat. Nos. 7,480,967, 2,956,324 and 4,054,972. The first of these shows a conventional belt buckle with a typical prong to engage through a selected hole in an end portion of a belt, but with a mechanism to remove the terminal, active part of the belt buckle from a separately formed base end, with a slide-apart motion. A male cylinder component slides into a female cylindrical slot, with a ball and detent provided to hold these components together. The buckle is not of low profile in the lateral direction, and the slide-apart feature is not used to engage and release the belt from the person's waist, but rather to remove the operative buckle component from the base part of the buckle.
U.S. Pat. No. 2,956,324 noted above describes a buckle with cylindrical slide-together parts configured on a slant, the assembly not being one of low profile. U.S. Pat. No. 4,054,972 shows a typical brassiere clamp that involves sliding the components together vertically in the typical manner.
U.S. Pat. Nos. 4,282,634 and 5,447,092 describe belt buckles with typical male/female components configured to plunge together in the axial (belt-tightening) direction of the belt, engaged by plastic spring tabs that snap into place.
SUMMARY OF THE INVENTION
The invention is a two-part belt buckle, preferably formed of molded plastic (such as injection-molded nylon or acetal) and of a low profile laterally (left to right as worn) so as to preserve space in the belt's span for tactical or other equipment to be retained on the belt. To this end the two parts of the buckle have male and female components that slip together and apart in a vertical motion relative to one another, which enables a buckle design of limited lateral width, occupying, for example, only about 1¾ inches of belt space, or even less, such as 1½ inches. The buckle has a slender and smoothly contoured exterior when clipped together, and tends to appear as a single body on the belt.
This is achieved with male and female buckle components, the male component having an elongated lug of preferably rectangular cross section that slides vertically into and latches in a complementary slot in a casing of the female component. Each component has an outer or outboard side, to which the belt is affixed, and to facilitate the sliding together of the lug and slot. The outboard part of the male component is connected by a thin bridging element to the lug, and the female component has a narrow slit opening the slot on the connecting side. Thus, the thin bridging element slides through the slit as the male lug slides into the slot.
The two components latch together via a spring latch of the male lug, a cantilevered plastic arm that is squeezed to a slightly retracted condition during insertion of the lug and then snaps back outwardly (forwardly, with respect to a person when worn) when the end of the spring latch reaches an open notch of the slot in the casing. This occurs when the lug is fully inserted into the slot, the two components being securely nested together. In a preferred form the spring latch's end is a rounded knob that becomes exposed at the front of the buckle when secured, so that the knob can be pushed in for release, allowing separation of the two components.
It is a main object of the invention to provide a narrow two component service belt buckle that leaves a maximum of belt span for carrying tactical weapons and other service equipment on the belt, especially at the front of the user. This is accomplished with two buckle components that slide together vertically and snap into a latched state, conveniently released by the wearer when desired. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a belt buckle of the invention in a secured configuration, and indicating attachment of the belt.
FIG. 2 is an exploded view showing the two components of the buckle in perspective.
FIG. 3 is a top plan view showing the belt buckle as secured together.
FIG. 4 is a sectional view as seen along the line 4 - 4 in FIG. 3 , showing the secured buckle.
FIG. 5 is an end view of the connected-together buckle, seen from what could be the bottom or the top of the buckle, essentially from the left in FIG. 1 .
FIG. 6 is a sectional view of the secured belt buckle, as seen along the line 6 - 6 in FIG. 3 .
FIG. 7 is a bottom or back side plan view of the secured buckle.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a belt buckle 10 of the invention in a secured-together condition, and indicates two ends of a belt 12 connected to the two belt buckle components 14 and 16 . Note that the belt is shown connected by looping over a bar 18 at outer or outboard sides of each of the two components 14 and 16 (only visible on the component 16 in FIG. 1 ). Other types of connections to the belt could be employed, and the bar 18 could be replaced with a double bar system for webbing tensioning. The figure shows a latch device 20 , seen here as a somewhat rounded knob, that pops up into place in a notch 22 when the two components are fully inserted together.
FIG. 2 shows the two components 14 and 16 separated, in exploded view. The male component 14 has an elongated lug 24 that, as indicated, inserts into a slot 26 of the female component 16 . The elongated lug 24 preferably is essentially rectangular-shaped in cross section as shown, with parallel sides and of a configuration to fit closely within the slot 26 of the female component 16 . The slot 26 is formed within a casing 28 , this casing having a narrow slit 30 at a connection side of the component 16 , and this slit, although not so indicated in FIG. 2 , extends to the right in the drawing completely to the end of the slot 26 . The purpose of the slit 30 in the side of the slot is to enable the slug lug 24 to be inserted in the slot 26 without interference from the remainder of the male component 14 , which includes an outer or outboard side 32 as seen in FIG. 2 . The outboard side 32 of the male component is connected to the lug 24 by a narrow bridging element or plate 34 , and this bridging element 34 slides through the slit 30 in the side of the slot 26 as the belt components are assembled together. The bridging plate 34 terminates as shown without reaching the end of the lug 24 (i.e. at the left in FIG. 2 ), so that the slit 30 need not extend completely to the end of the slot (at left in FIG. 2 ), leaving some solid structure for integrity of the female component.
The latch device 20 , as seen in FIG. 2 , is essentially a cantilevered leaf spring 36 formed integrally with the remainder of the preferably plastic female component 14 . This cantilever has a free end at the left in the drawing, and this free end has a latch component that can comprise the generally rounded knob 20 seen in the drawings, although other shapes can be used. As can be seen from FIGS. 1 and 2 , the rounded knob provides an incline that forces the cantilevered latch leaf spring 36 to an inwardly compressed position as the lug 24 is pushed into the slot 26 , but when the latch component 20 reaches the opening or notch 22 , the cantilever spring snaps the latch component 20 outwardly, up into the notch, locking the male component at the fully inserted position in the female component. For release, a wearer simply pushes the exposed rounded knob or latch component 20 inward (toward the user's body), allowing the male component to be slid out and removed from the female component.
FIG. 3 shows the secured belt buckle in plan view. The drawing shows elongated openings 40 , one on each component, for receiving the belt, which loops over the bar 18 on each component. The male component 14 is shown at the upper side of FIG. 3 , as it is in FIGS. 1 and 2 . As seen in all of FIGS. 1 , 2 and 3 , the female component's casing 28 has a form of step 42 at its outer surface, and the outboard side 32 of the male component has a similar, complementary-shaped flange or edge 44 . The flange 44 abuts the step 42 when the male component is fully connected into the female component, as can best be seen in FIGS. 2 and 3 . This defines the fully connected position and serves to prevent further sliding of the lug 24 through the slot 26 , even with force. Note that this function could also be accomplished by other structural limiting features, if desired.
A part 45 at one end of the female component 16 is seen in FIG. 3 . This slides under the adjacent structure of the male component's outboard side 32 as the male component 14 is slid to the right in FIG. 3 , or the female component 16 to the left in FIG. 3 . It slides under the element 44 , which can be understood with reference to FIG. 2 as well as FIG. 3 .
FIG. 4 shows the two components in cross section, in the fully secured position, and indicates the action of depressing the rounded knob latch component 20 inwardly for release (the depressed, released position of the latch is shown in dotted lines). As illustrated, the rounded knob or latch component has a ledge abutment 46 at its back edge closer to the point of cantilever support, and this snaps out into position (solid lines in FIG. 4 ) when the fully inserted position is reached, held in place by engaging with a face 47 of the female component.
Preferably each of the components 14 and 16 is injection molded of a strong plastic material, with the cantilever spring element or latch component integrally molded in the male component.
The sectional view of FIG. 6 again shows the belt 12 secured to the outer or outboard sides of the male and female components, each belt end looping over a connecting bar 18 of the respective component. As noted above, other belt securement arrangements are possible. The lug 24 is shown within the slot 26 , the lug being without walls at upper and right sides in this central region, which can be seen from FIG. 2 . The thin bridging element 34 is seen extending through the slit 30 , and a wall 48 at the outboard side 32 of the male component is seen integrally connected to the bridging element 34 . The secured buckle can withstand very high belt tension, due to the engagement of the entire length of the lug 24 against the entire length of the outer wall of the female component 16 , at both sides of the slit 30 (above and below the slit as seen in FIG. 6 ). Moreover, the slit 30 is open at its end which is shown to the right as the component is viewed in FIGS. 2 and 3 , and could tend to spread open and fail under very high belt tension. Spreading is prevented by the flanges 44 of the male component, the flanges 44 being on both front and back and retaining the structure at the slit from spreading open. See also FIGS. 6 and 7 . The width of the assembled belt buckle (dimension from left to right as worn) is indicated, and as noted above, this is preferably no more than about 1¾ inches or preferably in the range of about 1½ to 2 inches. A typical belt that connects together horizontally with a similar latch oriented horizontally would be about 2% to 3 inches wide. The height of the buckle can vary according to the belt, but may be about 2½ inches, or about 1½ to 3 inches. The buckle is intended for a belt of at least about 1¾ inch width, preferably at least about two inches width.
As seen in the drawings, the assembled belt buckle is smoothly contoured, with rounded sides and edges and with the two components closely mated. As such, the secured buckle gives the appearance of a slim, smoothly contoured and unitary device when worn.
The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A belt buckle primarily for law enforcement or military personnel, for a relatively wide service belt, is of low profile, i.e. narrow from left to right so as to occupy minimal belt span to provide maximum space for equipment to be supported on the belt.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This relates generally to MOS devices and fabrication methods therefor and, more particularly, to MOS devices having ion-implanted regions and fabrication methods therefor.
2. Description of the Prior Art
In the past, read-only memories (ROM's) have been implemented in a variety of integrated circuit technology. With the advent of large-scale integrated (LSI) circuits in the MOS format, most prior art ROM's have utilized the N-channel conductivity type devices as opposed to P-channel conductivity type devices because of the increased speed performance possible with the former.
There remains an unfulfilled need for integrated circuit ROM's of lower power consumption. On a theoretical basis, at least, this need may be filled by complementary MOS device ROMs. However, the N-channel device configurations used heretofore in MOS LSI circuits are not viable for the achievement of high density in a row-column array organization of a typical memory.
In order to achieve high density, MOS integrated circuit logic or memory operates at least internally with very low currents in order to achieve small device sizes. The overall size of the integrated circuit, however, is determined not only by the device sizes but also by their packing density. If very low current devices are placed extremely close to each other, the possibility for interaction due to common conduction paths is increased. While there are many known techniques for minimizing or virtually eliminating inter-device interactions which result in false signals, these known techniques consume excessive space in a memory array and, hence, increase the size of the circuit and decrease the yield.
SUMMARY OF THE INVENTION
It is the object of the present invention to increase the packing density of MOS devices by techniques which do not detract from the overall yield of the circuit.
It is a further object of the present invention to maximize the packing density in row-column arrays suitable for MOS memory devices.
It is yet another object of the invention to provide a method of making MOS ROMs by a simplified masking sequence.
It is yet still another purpose of the invention to provide MOS devices for a CMOS ROM wherein the means for reducing the interactions of the devices in the memory array can simultaneously enhance the performance of the complementary devices associated therewith.
It is yet another object of the instant invention to provide means for reducing the interaction between adjacent complementary devices which may result in circuit failure due to a latching action.
In order to achieve these as well as other objects, ion-implanted regions are provided intermediate to potentially interacting devices. In some cases, these intermediate ion-implanted areas are contiguous with the channel regions of the respective devices. In yet other instances, the intermediate ion-implanted regions are intermediate but remote from the channel regions of the respective MOS devices.
An MOS device typically comprises a thin insulating layer over its channel region; this thin insulating layer is overlaid by conductive gate means for controlling the channel conductivity. In a typical embodiment, the regions adjacent to the gate of the device are covered by a field insulator which is substantially thicker than the thin gate insulator in order to reduce the field which induces a stray channel peripheral to the desired MOS device. The amount of the stray channel current cannot be reduced arbitrarily because it is determined by the values of the thin and thick insulator thicknesses which are ordinarily limited in practice by the thickness ratio of the insulators necessary to achieve good yields. While it is known to reduce or eliminate such stray paths by the use of channel-stop regions opposite in conductivity to that of the desired channel, when these regions are remote from the channel region of the desired device, they require an unwarranted amount of space. When such channel-stop regions are immediately adjacent to both the channel and the source drain regions of the desired MOS device, they may undesirably reduce the breakdown voltage of the device and they have the further disadvantage that, since the channel-stop regions and the gate regions are ordinarily formed in two different process steps, mutual alignment is difficult to achieve. In a preferred embodiment of the instant invention, the above problems are overcome by extending the thin gate insulator to the peripheral regions of the device. After the gate conductor has been formed and patterned over only a portion of the gate insulator, ion-implantation is used to provide channel-stop regions which are self-aligned contiguous with the desired channel by virtue of the fact that the ion-implantation process is masked by the patterned gate conductor and the field insulator. In a preferred sequence, a thin insulating region is formed to include both the desired channel region and the peripheral regions flanked therewith. This obviates the need for a separate patterning step to form the channel-stop regions proximate to the desired device.
In the above-described sequence, the gate conductor is formed and patterned completely separately from the source and drain regions. This sequence precludes the self-alignment of the source and drain to the gate which is achieved by typical MOS LSI processes. Where the integrated circuit array comprises both N-channel and P-channel devices, however, this disadvantage is at least partially obviated by the possibility of using the channel-stop ion-implantation for one conductivity type in order to provide self-aligned source/drain regions in the device of opposite channel conductivity type. Additionally, where the device is a first-channel conductivity type or employed in a row-column array memory having alternating rows of continuous source or drain regions providing both the sorce-drain function and an interconnection function and columns of gate conductors providing both the gate function and an interconnection function, the necessity for individual gate to source or drain self-alignment in the matrix is obviated. Thus, effective simultaneous self-alignment of gate to source and drain is achieved in both the matrix regions of the integrated circuit comprising devices of a single-channel conductivity type and, in complementary devices remote from the matrix.
In yet another embodiment of the instant invention, intermediate ion-implanted regions are used to minimize the interaction between higher current MOS devices which serve, for example, as input/output devices to connect with external circuitry. A CMOS device pair inherently contains a bipolar transistor which can interact with the drain of an adjacent device so that the pair remains in the conducting state as a result of latch-up. As a result of this four-layer interaction, the pair then is rendered useless in terms of its desired circuit function. Latch-up is ordinarily more of a problem at higher currents because bipolar transistor gains increase with current. In order to reduce the tendency for the higher current device pairs to latch-up, the instant invention contemplates the inclusion of an implanted region between the two complementary devices in such a way that the overall gain of the parasitic four-layer device is reduced.
The above embodiments of the instant invention are more fully described in the following detailed description and drawings associated therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top view of a portion of a memory array employing a preferred embodiment of the instant invention.
FIG. 1B is a variation of the embodiment of FIG. 1A which is useful in achieving increased device density in a memory matrix.
FIG. 2 is a cross-sectional view of FIG. 1B showing the details of the construction thereof; this figure is also illustrative of the embodiment shown in FIG. 1A.
FIG. 3 is a top view of a complementary transistor suitable for use with the devices shown in FIGS. 1A and 1B and which makes use of an ion-implanted region formed simultaneously in both devices.
FIG. 4 is a cross-sectional view of a pair of complementary MOS devices showing how an intermediate ion-implanted region is located in order to minimize device interaction.
FIG. 4A is an alternative embodiment of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1A is a top view of a portion of an MOS memory matrix utilizing one of the preferred embodiments of the present invention. This figure shows four of a multiplicity of MOS devices arranged in rows and columns to form an MOS memory matrix. Four devices along one row are shown; the array is repetitive in both directions. Region 1 is a semiconductor substrate region of first conductivity type which serves as a common element for all of the MOS devices. Region 2 is a semiconductor region of second conductivity type opposite said first conductivity type and extending in the row direction of the matrix. Region 3 is essentially identical to the region 2; either region 2 or 3 may form a common source for each of the four MOS devices while the other of the regions 2 and 3 form a common drain. Regions 2 and 3, which are relatively heavily doped, serve as both the sources or drains of the MOS devices as well as conductive interconnections between the common sources and drains. All of the semiconductor regions 1, 2, and 3 are covered by an insulating layer which isolates the conductive means comprising stripes 11, 12, 13, and 14 over the channel between each source and drain which serve as gates for controlling the channel current. The sources and drains are thus all parallel with a first direction in the circuit and the conductive means over the channel regions are parallel with a second direction perpendicular to the first direction.
To achieve a ROM function, certain preselected MOS devices in the array must conduct relatively more current than others of such devices. In the embodiment shown in FIG. 1A, this differential current carrying capability is made to occur by providing a thin insulating layer in regions bounded by 10 underlying the gates, for example, 12 and 14 of two out of the four devices. Thus, when the potential is applied between source and drain semiconductor regions 2 and 3 and gate voltages are applied on gate conductor columns 11, 12, 13, and 14, the MOS devices comprising the thin insulating layers conduct relatively more than those comprising the insulating layers because the field normal to the plane of the drawing is relatively greater for the thin insulator devices. Hence, a greater local current flows between the source and drain elements of these devices than of the thick insulator devices.
In order to achieve the desired memory function, a thin insulator device adjacent to a thick insulator device must not be turned on when the gate voltage is only applied to the thick insulator device. For example, in FIG. 1A if the potential on gate line 11 is such as to induce a conducting channel between the source/drain regions 2 and 3 beneath the conductive layer 11 (if the conductor overlaid a thin gate insulating region) while the potential on gate line 12 is such as to preclude the formation of such conducting channel, then any stray fields from the gate line 11 which induce a conducting channel in the thin oxide region bounded by 10 of the MOS device under gate line 12 will give a false indication that the thick insulator device under gate line 11 is on when, in fact, little current is carried by that device. In this embodiment, such extrinsic or parasitic induction is reduced by the ion-implanting impurities of first conductivity type into the top surface of the device. By selecting ions of appropriate energy, they can be made to penetrate through the thin gate insulator region bounded by 10 into the regions 1, 2, and 3 of the semiconductor substrate. The thicker gate insulator under the desired off devices as well as the conductive gate lines 12 and 14 stop such a high percentage of the incoming ions that there is substantially no implantation nor effect in the semiconductor substrate in regions under the thicker insulator or under the gates. Thus, the channel-stop region 4 is contiguous with the channel of the device.
FIG. 1B shows an alternative embodiment of the preferred memory embodiment wherein the gate lines consist of alternating columns 5 and 6 of two different materials. This may be seen in more detail in FIG. 2 which is a cross-section of FIG. 1B gate conductor 6, for example, may be of polycrystalline polysilicon while gate conductor 5 may be formed of metal such as aluminum. This is advantageous because, if after formation of the gate column 6 of polycrystalline silicon, the polycrystalline silicon is oxidized in order to form a thin insulating layer on its top and sides, then gate columns 5 of metal may be formed in close proximity to column 6 without the risk of obtaining shorts between the two adjacent columns. In this way, a considerably higher density of devices along a row may be achieved. For example, FIG. 1B shows gate columns 15, 16, 17, 18, 19, and 20 occupying approximately the same space as the gate columns 11, 12, 13, and 14 of FIG. 1A. As may be further seen in FIG. 2, the insulating layer 9, which is thicker than insulating layer 8, forms one lateral boundary 10 of the ion-implanted channel stoppers of P-channel conductivity type the same as that of substrate 1. In this Figure, the substrate has P- conductivity type; this is only illustrative of the invention and either conductivity type could be used to provide devices of desired channel conductivity type opposite to the substrate conductivity type. Gate conductors 5 and 6 patterned to form gate columns 15, 16, 17, 18, 19, and 20 form the other lateral boundaries of regions of the ion-implanted channel regions 4. The thin insulating layer 8 is approximately 800 angstroms thick and is desirably made of silicon dioxide. The thicker field insulating layer 9, also desirably made of silicon dioxide, is approximately 8,000 angstroms thick. As may be seen clearly in FIG. 2, a conducting channel into the plane of the drawing is bounded by the ion-implanted channel stop region 4. Thus, if the potential under gate column 16 and 17 is such that the conduction in the corresponding MOS devices is desirably zero, a conducting channel inducing potential on either or both of gate lines 15 or 18 channel will not induce a stray channel in either of the MOS devices under gate regions 16 and 17.
In addition to the density advantages illustrated by FIGS. 1A and 1B and FIG. 2, the configurations illustrated therein are highly desirable from the standpoint of view of simplified processing. That is, the preselected thin oxide regions bounded by 10 constitute the only process difference between the desirably on and the desirably off MOS devices. Thus, the ROM function that is achieved by using a mask corresponding to the preselected conduction pattern at only one step of the process. If the channel-stop regions were not self-aligned by virtue of the thin oxide regions bounded by 10, then either another mask would be required to put the channel-stop regions adjacent to the desired conducting devices, or all the devices would have to have channel-stop regions formed by another pattern which would require much more space than that needed by the method of the present invention.
The most common MOS LSI integrated circuits today are formed by using polycrystalline silicon gates with the individual sources and drains of each device self-aligned to the gates by means of a doping step which is masked by the gates and their underlying oxides. This technique achieves minimum geometry devices in terms of a channel length L depicted in FIG. 1A. However, in the memory matrix application shown in FIGS. 1A and 1B, it is seen that the self-alignment feature is not required even when a metal gate such as 11 or 12, in FIG. 1A, or 13, 15, 17, and 19, in FIG. 1B, are utilized. Where complementary devices are required in the same circuit, however, the use of metal gates that require their alignment to the source and drain region by means of two separate masking steps which, due to tolerances, increases the length L between the sources and drains of the devices.
FIG. 3 shows how this undesired characteristic may be obviated using an ion-implantation step common with that used to form the channel stoppers in FIGS. 1A, 1B, and 2. Here, 11 is the local substrate region for the complementary device which comprises source 22 and drain 23 of semiconductor conductivity type opposite to the local substrate 11. 55 is a gate region located between regions 22 and 23. In order to achieve channel conduction between regions 22 and 23 underneath gate 55, the latter would ordinarily have to cover the entire insulating layer between regions 22 and 33. Because regions 22 and 33, and region 55, are formed in different masking operations, the tolerances dictated by this requirement would unnecessarily increase the size of the device. The length L can be minimized, however, by the embodiment shown in FIG. 3. Here, a thin insulating region bounded by lines 100 is again used to permit the implantation of an impurity in regions 4. However, the same impurity is used as formed the channel stops for the memory matrix devices and, hence, the implantations may be simultaneous. This impurity is opposite to the conductivity type of the localized substrate 11 of FIG. 3 and, hence, of the same conductivity type as the source and drain regions 22 and 23, and thus, acts to form local extensions or castellations of these regions of the source/drain regions in the area between them and the gate that is bounded by the lines 100. Thus, the source and drain are exactly aligned with the gate allowing a minimum gate width L determined only by the minimum line width that can be achieved in defining gate 55.
FIG. 4 illustrates another embodiment of the instant invention. Here, the adjacent transistors, unlike those in FIGS. 1 and 2, are opposite or complementary channel conductivity type. An N-channel MOS device comprises source region 2, drain region 3, thin-gate insulator region 8, and gate region 26. P-channel device comprises source region 33, drain region 22, and thin-gate insulator region 8. The drain 3 of the N-channel device and the drain 22 of the P-channel device are interconnected by means of the conductive means 66 which lies over thicker insulator region 9. Region 44 formed at the same time as the P+ source and drain regions 22 and 33 serves as a channel stop to preclude any unwanted conduction across the surface in the inter-device region. Likewise, N+ region 55 formed at the same time as N+ source and drain regions 2 and 3 serves to enhance the surface of the N- substrate 7 and further precludes unwanted surface currents.
However, even if the unwanted surface currents are obviated by the channel-stop regions 44 and 55, another type of conduction may take place in the complementary pair of devices shown in FIG. 4. This comes about because there is an NPN transistor formed by N+ region 2 acting as an emitter; P- region 1 acting as a base and N- region 7 acting as a collector. This parasitic bipolar transistor merges with a parasitic bipolar transistor formed by P+ region 22 acting as an emitter N- region acting as a base and P+ region 44 and P- region 1 acting together as a collector. When the sum of the current gains of the two devices exceeds unity, the ability to block current between region 22, the drain of the P channel MOS device and region to the source of the N channel MOS device is lost. This effect is particularly troublesome where the MOS devices must carry relatively high currents because the current gain of most bipolar transistors increases with current in the high current range. The gain of the parasitic PNP transistor is reduced to some extent by the channel-stopper region 55 which introduces extra impurities into the base region 7. However, it is still possible for carriers injected from P+ region 22 into N- region 7 to reach the composite collector 1 and 44 by flowing underneath channel-stopper region 55. In order to further prevent unwanted transport of injected carriers across base region 7, N region 110 is provided in the base of the parasitic PNP transistor. As in the previous embodiments, this base may be implanted through a thin oxide and, hence, serve multiple functions such as a channel stopper described in the previous embodiments. Space is best conserved by locating the N region 110 in at the same site as N+ channel stopper 55; current gain is best reduced if the N-region extends substantially below N+ channel stopper 55. The implanted region 110 of the same conductivity type as the drain of the N-channel transistor is remote from the drain 2 unlike the configurations of FIG. 1; the carrier doping in region 110 is higher than the doping in the channel region underneath the gate 25 of the P-channel device.
FIG. 4A shows an alternative embodiment of the device pair just described. Here the P-channel transistor comprising source 33, drain 22, gate insulator 8, and gate 25 contains a conducting channel 4 formed by the same ion-implantation used to form the channel stops for the N-channel transistors hereinbefore described. The lightly-doped P-type region 4 comprises a conducting channel for the device if the implantation penetrates both the thin insulating layer 8 and gate 25, or if the implantation is carried out prior to the formation of the gate 25. As yet another alternative, the P-channel device may be similar to the P-channel device of FIG. 3; in that case the ion-implantation fails to penetrate beneath the gate 25 so that the source and drain regions are effectively self-aligned with the gate.
While the invention has been particularly described and illustrated in terms of the foregoing embodiments and applications thereof, it will be apparent to one skilled in the art that the concepts illustrated thereby are not limited to the envisioned specific applications envisioned. The ion-implanted channel stopper regions illustrated in FIGS. 1 and 2 are perhaps applicable to other repetitive device structures such as charge coupled devices. Such regions could also be used in a discrete device to accurately define the channel region. The simultaneous implantation of each of two complementary transistors form channel stoppers in the first and self-aligned source drains in the second applications in many CMOS integrated circuits. The embodiment illustrated by FIG. 4 is useful whether or not the conductor 66 interconnects the drains of the two devices; in fact, the configuration is useful wherever two CMOS devices are in proximity and prone to latch-up. Thus, the invention is not limited by the foregoing description but rather as well by the following claims.
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Integrated MOS devices with intermediate ion-implanted regions for minimizing device interaction. Several configurations are detailed; they are individually or, in combination, extremely useful in maximizing the density of ROM functions implemented in the integrated circuit format. In particular, one of the embodiments enhances the achievable density in a row-column array used in ROM memories. Used together, the embodiments are especially suited for a ROM of the CMOS genre.
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BACKGROUND OF THE INVENTION
This invention relates to bearing structures and more specifically to an improved bearing assembly for venting a wheel bearing used on boat trailers, conveyors and the like.
Prior art sealed bearings are packed in grease without adaquate pressure relief. Excessive pressure build-up in these bearings during outside temperature change as well as heat produced therein by friction during normal trailer operation causes expansion of the packing grease and the consequent compression of air trapped in the bearing chamber. Such excessive pressures are undesirable in that they force grease through the sealing surfaces of the bearings relieving pressure therein and they contribute to early failure of the bearing structure.
The towing of the boat trailer to the boat launching site also causes bearing and grease friction which generates heat within the wheel hub. This heat causes pressure to build up within the hub which in turn causes air and grease within the hub to escape through the rotating seal. Then, at the boat launching site, when the boat trailer is backed into the water to launch the boat, the submerged hub is suddenly cooled by the water. This cooling contracts the air inside the hub and creates a partial vacuum therein which causes water and silt to seep into the hub. The resulting rust and erosion inevitably causes bearing damage.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 1,660,728 discloses a depressed hub cap with a pressure grease gun nippled fitting secured in the depression.
U.S. Pat. No. 1,776,641 discloses a hub cap which is permanently attached to the other end of a wheel hub shell.
U.S. Pat. No. 3,077,948 discloses a hub cap apparatus employing a cylindrical member containing a free floating spring loaded piston having a grease fitting. The piston initially seals the hub. As the hub is filled with grease, the pressure forces the piston to move until the hub is no longer sealed. At this point, the excess grease escapes so that the spring loaded piston again seals the hub.
U.S. Pat. Nos. 3,102,737 and 3,649,080 disclose pressure equalization means for preventing damage to bearings and grease seals of boat trailers.
U.S. Pat. Nos. 3,320,006 and 3,320,007 disclose venting means for translation and rotational devices for relieving internal pressures.
U.S. Pat. No. 3,393,015 discloses a hub cap employing an O-ring which encircles a valve opening. The O-ring is forced away from the opening by internal pressure.
U.S. Pat. No. 3,460,874 discloses a sealed bearing structure employing a check valve located on the axis of rotation of the hub for permitting the exit of air under pressure from the sealed bearing structure while preventing entry of water into the sealed bearing structure on immersion of the hub and axle in water.
SUMMARY OF THE INVENTION
It is, therefore, one object of this invention to provide a new and improved bearing assembly.
Another object of this invention is to provide an improved bearing assembly for boat trailers which automatically relieves pressure increase due to pressure lubrication or temperature rise without damaging the bearings or sealing surfaces of the assembly.
A further object of this invention is to provide a new and improved sealed bearing assembly which automatically relieves any vacuum therein caused by the temperature drop occurring when the hot bearing assembly is emerged in the cold water of a lake or river.
A still further object of this invention is to provide a new and improved sealed bearing assembly which prevents contaminants from entering the bearing area of the assembly.
A still further object of this invention is to provide a new and improved sealed bearing assembly which provides a grease flow path from the bearing area of the assembly through all or at least a part of the spindle axially and laterally thereof to atmosphere for relieving pressure in the grease fitting.
A still further object of this invention is to provide a new and improved sealed bearing assembly in which substantially 100 percent of the cavity in the bearing assembly is filled with grease resulting in less pressure change therein due to temperature changes.
A still further object of this invention is to provide a new and improved sealed bearing assembly wherein repacking of the bearing can occur without disassembling of the bearing assembly.
A still further object of this invention is to provide a new and improved sealed bearing assembly which deposits any excess grease discharged from the bearing assembly at a point away from any rotating surface.
Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be more readily described by reference to the accompanying drawing in which:
FIG. 1 is a perspective view of a bearing assembly mounted on a boat trailer axle and embodying the invention claimed;
FIG. 2 is an enlarged cross-sectional view of the bearing assembly shown in FIG. 1 taken along the line 2--2;
FIG. 3 is a partial perspective view illustrating the use of the bearing assembly on a conveyor belt structure;
FIG. 4 is a partial front view of the trailer spindle shown in FIG. 1 illustrating the drain hole extending laterally thereof;
FIG. 5 is a partial perspective broken away view of a modification of the spindle assembly illustrated in FIGS. 1, 2 and 4 showing the drain hole axially of the bearing assembly;
FIG. 6 is a partial perspective broken away view of a still further modification of the spindle assembly shown in FIGS. 1, 2, 4 and 5 showing the drain hole laterally of the bearing assembly; and
FIG. 7 is an exploded perspective view of the bearing assembly shown in FIGS. 1-6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings by characters of reference, FIGS. 1, 2 and 4 disclose a cylindrical hub cap 10 mounted in a wheel hub 11 which is free to rotate about a spindle 12 by means of bearings 13 and 14. A rotating seal 15 seals a chamber 16 within wheel hub 11 while allowing rotation between wheel hub 11 and spindle 12. The wheel hub 11 is retained in place upon the spindle 12 by means of an attachment means such as a nut 17 held against accidental rotation by any suitable means such as a cotter key (not shown) used in the well known manner at the end of spindle 12 and this nut engages a washer 18 at its inner end. This washer snugly engages the axial outer end of bearing 13.
As shown more clearly in FIG. 2, spindle 12 is reduced in diameter at its outer end with the annular bearings 13 and 14 being spacedly positioned thereover. The hollow wheel hub 11 is provided with a cylindrical portion which is sleeved at one end over the spindle and bearings and has an inwardly extending portion 11A for maintaining the bearings in axially spaced apart relationship along the spindle. The washer 18 and nut 17 threaded over the threaded end of the spindle is in contact with bearing 13 urging it into contact with the radially inwardly extending cylindrical portion 11A and urging bearing 14 also in contact with this portion 11A at its other edge.
The outer end of the hub cap 10 is provided with an opening 19 for receiving the stem 20 of a grease plug or conventional grease gun fitting 21.
To install hub cap 10 in the open end of wheel hub 11, its shouldered end 10A is tapped into the wheel hub to produce a tight interference with the wheel hub.
As shown in FIG. 1, a boat trailer wheel 22 shown in dash lines is suitably bolted to the wheel hub 11 in the usual manner for rotation with axle 23 of the boat trailer.
A conventional grease gun filled with suitable lubricant can be connected to conventional grease fitting 21 on hub cap 10. The grease is pumped into wheel hub 11 and starts to fill it up under pressure. The pressure build-up within hub cap 10 forces grease through the passageways 24 in bearing 13 and into and longitudinally of the chamber 25 formed between the inside surface 26 of wheel hub 11 and the outside surface 27 of spindle 12 as shown by arrows A. The grease under pressure then moves from chamber 25 through passageways 28 in bearings 14 and into chamber 16 formed in the wheel hub 11 between rotating seal 15 and bearing 14.
As noted from FIG. 2 of the drawing, a passageway 29 is provided to extend from chamber 16 laterally through spindle 12 to an interconnecting passageway 30 extending axially through the end 31 of spindle 12 which is fixedly secured in the hollow interior of axle 23. Axle 23 is provided with a port 32 which provides an opening for the draining of any grease or air under pressure to atmosphere that flows out of passageway 30 in spindle 12.
Thus, passageway 29 drilled in the spindle 12 between seal 15 and bearing 14 together with passageway 30 in spindle 12 provides with port 32 in axle 23 an opening from the inside of the bearing area to atmosphere. It should be noted that the length of passageway 30 should be long enough to contain enough grease to provide a dam, reservoir or barrier to prevent water and other contaminants from entering the bearing structure through port 32 and to provide enough grease to compensate for pressure differences in the bearing structure caused by vacuum conditions resulting from temperature variations. The diameter of port 32 should be large enough so as not to restrict the flow of grease while lubricating the bearing structure through fitting 21 or when temperature changes occur within the bearing structure.
The disclosed sealed bearing assembly can be easily lubricated through fitting 21 without danger of damaging the bearing and sealing structures since the relief passageways 29 and 30 and port 32 provide for pressure release. These passageways and port also relieve pressure due to temperature or vacuum changes within the assembly and prevent contaminants from entering the bearing area all without any mechanical devices such as release valves and/or spring loaded devices.
Further, substantially 100 percent of the cavity in the bearing assembly is filled with grease resulting in less pressure change in the assembly due to temperature changes.
It should also be noted that the bearing assembly may be replaced without disassembling the unit. New grease added always forces the old grease out of the assembly through passageways 29 and 30 and port 32.
FIG. 3 illustrates a partial view of a conveyor mechanism 33 employing a plurality of sealed bearing assemblies embodying the invention wherein like parts have similar references. In this instance, the wheel hub 11 of FIGS. 1 and 2 have been replaced by a cylindrical hub 34.
FIGS. 5 and 6 illustrate modifications of the sealed bearing assemblies for trailers shown in FIGS. 1 and 2 wherein like parts have the same reference characters.
In FIG. 5, a trailer axle 35 forming a right angle hollow configuration extends laterally from the spindle 12 of the bearing assembly with passageway 30 in the axle opening directly to atmosphere.
In FIG. 6, the right angle hollow axle configuration 26 is open to atmosphere at its elbow as shown.
It should be noted that although a pair of spaced bearings 13 and 14 are shown in the preferred embodiment, one bearing structure or bushing could be used in lieu thereof and still fall within the scope of this invention.
Further, unlike other trailer mounted bearing assemblies that vent to the atmosphere at a point where the discharged excess grease is thrown all over the trailer wheels, tires and side of the boat, the claimed structure vents to the atmosphere inside of the trailer frame depositing excess grease away from rotating surfaces.
Although but a few embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.
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A sealed bearing assembly which provides a grease flow path from the bearing area of the assembly through at least a part of the spindle and outwardly thereof to atmosphere for relieving pressure in the grease fitting and making it possible to repack the bearing without disassembling the structure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention is related to a method and an apparatus for rotating a component of a wind energy plant by traversing an adjustment device. Adjustment devices are used in wind energy plants for rotating various components. A known example is the blade pitch angle adjustment device, by which the blade pitch angle of the rotor blades of the plant is adjusted. By doing so, the rotor blades are rotated around their longitudinal axes. Such a blade pitch angle adjustment device is usually a part of a so-called pitch regulation. Another also known example are azimuth adjustment devices, by which the machine house of the wind energy plant is rotated around the longitudinal axis of the tower. Such azimuth adjustment devices form a part of a so-called azimuth system of the wind energy plant, which has the objective to orient the machine house or the nacelle of the wind energy plant, respectively, at optimum to the wind direction, and to untwist the lines running between the tower of the plant and the machine house (the cable loop) from time to time. Such azimuth systems are known from Erich Hau, Windkraftanlagen, Springer Verlag, 3th edition, page 309ff., for instance, the entire contents of which is incorporated herein by reference.
[0004] Normally, the adjustment devices feature one or more adjustment drives. In azimuth adjustment drives, for instance, a planetary gearbox, a motor, an electric motor for instance, and a braking device, an electric brake for instance, is usually provided. In this, the output gear pinion of the gearbox meshes with the toothing of an azimuth swing bearing. The torques and the rotational speeds are geared up or down via toothings in the gearboxes. In the operation, the adjustment devices are exposed to changing dynamic loads, from the attacking wind in particular. In this, elasticities in the drives are generated, as a consequence of which the adjustment devices cannot instantaneously react on the exterior loads, or cannot suddenly apply a demanded driving torque, respectively. The elasticity of gearboxes depends on the tooth clearance of the individual tooth engagements. The more tooth engagements are used for the gearbox transformation, and the greater the respective tooth clearance is, the greater is the elasticity of the gearbox. In azimuth drives for instance, at a tightening up to the rated torque, the elasticity can amount up to ten rotations of the fast shaft of a four-step planetary gearbox. In the traversing of the adjustment devices, small partial moments are conventionally also distributed to the swing bearing or to the braking device used for holding the azimuth system, respectively, to the brake calipers in particular.
[0005] The driving torque of the adjustment drives is dimensioned for cases of high load, wherein the adjustment device experiences a change of the rotational speed when these cases of load are exceeded, when it is braked down or accelerated in particular. Furthermore, in the changes of the operation condition, namely holding after travelling and travelling after holding, load takeovers have to be realised which can lead to a decrease of the common driving/holding moment. These dropdowns of the moment can have various reasons:
[0006] When the wind loads require a change between driving and braking loads, the driving torque of the adjustment drives drops down, because the drives must retorque themselves anew over several rotations due to the existing elasticities. In addition, the adjustment drives, the azimuth drives in particular, can have a regulation imprecision when they are electrically triggered by soft start devices or frequency converters at low rotational speeds, in the starting in particular, and for this reason they may not react instantaneously to load changes. Finally, the rise of the detent torque of conventionally used brake calipers, which takes place via a wedge, may last for several seconds. Through this, the load takeover by the brake calipers is delayed for the drives.
[0007] It is known to maintain a detent torque by a braking device of the adjustment drives, for instance via a pressing force of corresponding brake calipers, so that the drives traverse against a base load. In the operation of the plant, there are cases of load in which the adjustment device is driven out of the wind or braked down by the loads. For instance, in the case of an azimuth adjustment device, the moments of the attacking loads are distributed to the partial systems azimuth drive, swing bearing and brake calipers of a braking device. For the case of a conventional azimuth system, the cases of load are listed in the following table. In this, the effect on the azimuth system by the detent torque of the brake calipers of the braking device is listed in particular:
[0000]
“Load case”
of the
azimuth
Azimuth
Brake
Swing
Effect to the azimuth
system
drive
calipers
bearing
system
Starting with
Driving
Holding
Holding
More difficult to start
counter-
Delayed starting
moment from
The detent torque makes
the wind
the starting even more
difficult
Travelling with
Driving
Holding
Holding
Reduced traversing speed
counter-
Frequent breakdown of
moment from
the rated rotational speed
the wind
The detent torque makes
the rotational speed
behaviour worse.
Stopping with
Braking
Holding
Holding
The detent torque
counter-
supports the
moment from
stopping procedure
the wind
Starting with
Driving
Holding
Holding
The detent torque
driving
protects against
moment from
exceeding the rated
the wind
rotational speed
Travelling with
Driving or
Holding
Holding
The detent torque
driving
braking
protects against
moment from
fluctuations of the
the wind
rotational speed
Stopping with
Braking
Holding
Holding
The detent torque
driving
supports the
moment from
stopping procedure
the wind
[0008] A disadvantage of applying a detent torque by a braking device in the traversing of the adjustment device is increased wear of the brake, and a regular maintenance which is required through this.
[0009] From U.S. Pat. No. 5,035,575 A, the entire contents of which is incorporated herein by reference, an azimuth system of a wind energy plant is known, in which two motors of the adjustment drives are operated in opposite senses with an equal torque in the standstill of the azimuth adjustment device. Through this, a tightening of the adjustment devices in the standstill is achieved. When the azimuth system is traversed, both motors rotate then in the same sense and with the same torque. Thus, no more tightening is achieved when the adjustment device is traversed by doing so. Furthermore, from DE 103 58 486 A1, the entire contents of which is incorporated herein by reference, an azimuth drive is known for a wind energy plant which features a hydraulic device for tightening the drives. In particular, two hydraulic motors are provided in this, which engage via corresponding driving wheels in opposite rotational senses and with equal torques on the output ring gear of an azimuth joint. Thus, a clearance between the drive components is intended to be eliminated. The azimuth system can be traversed with an adjustable delivery rate by means of a second pump which is also connected to the hydraulic circuit. In the known device, a sumptuous hydraulic system is required in order to achieve a clearance elimination by two driving wheels, operated in opposite senses of rotation with respect to each other and sitting close to a toothed output wheel.
[0010] Starting from the state of the art explained above, the present invention is based on the objective to provide a method and a device of the kind mentioned in the beginning, by which a tightening of the adjustment devices is possible in a simple and inexpensive manner.
BRIEF SUMMARY OF THE INVENTION
[0011] On the one hand, the present invention resolves the objective by a method for rotating a component of the wind energy plant by traversing an adjustment device, wherein the adjustment device comprises at least two adjustment drives, each one thereof having at least one electric motor for traversing the adjustment device, and wherein during the traversing of the adjustment device, the electric motor of at least one of the at least two adjustment drives is operated at another rotational speed than the electric motor of the at least one other one(s) of the at least two adjustment drives.
[0012] The present invention also resolves the objective by an adjustment device for rotating a component of a wind energy plant by traversing the adjustment device, with at least two adjustment drives, each one thereof having at least one electric motor for traversing the adjustment device, wherein the adjustment device features a control device, which is realised to operate the electric motor of at least one of the at least two adjustment drives at another rotational speed than the electric motor of at least one other one(s) of the at least two adjustment drives during the traversing of the adjustment device.
[0013] According to the present invention, the driving torques are distributed differently to the at least two adjustment drives. In particular, the required total driving torque is essentially applied by one or more motive drives, wherein at least one drive acts against the desired rotational sense with a small counter-moment. Thus, a tightening of the drives against each other is realised. In this, the other rotational speed of the electric motor of one of the adjustment drives can be in particular an (absolutely) smaller rotational speed than the rotational speed of the other electric motor or the other electric motors, respectively, of the other adjustment drive or the other adjustment drives, respectively. However, another rotational speed can also mean that the absolute values of the rotational speeds are equal, but the rotational speeds have different signs. In this case, the electric motors are operated in different senses of rotation. Due to the difference of rotational speeds according to the present invention, a tightening of the drives against each other is achieved. In particular, the toothing of one gearbox of the adjustment drives contacts in the direction opposite to the sense of rotation. In this way, elasticities of the drives are minimised. According to the present invention, a sufficient tightening of the adjustment drives against each other is achieved in a manner which is simple with respect to construction and control technique as compared to the state of the art. In particular, this tightening is also existent in the traversing of the adjustment drives. Thus, in the load-dependent drive control with mutual tightening of the adjustment drives according to the present invention, at least one drive acts against the remaining adjustment drive or drives with its driving torque. A higher stiffness in the traversing of the adjustment devices is achieved. Moreover, in this way the moment-free ranges arising through the elasticities of the drives, the so-called torque holes, are reduced in starting and stopping processes. For instance, the acceleration which the machine house of the plant experiences when torque holes occur is damped correspondingly. In addition, accelerations caused by wind loads, which are greater than the driving torques, are avoided. Also, inadmissibly high rotational speeds of the adjustment systems are prevented, which would otherwise lead to a damage of components of the wind energy plant.
[0014] The control device of the present invention is realised to trigger the adjustment drives or electric motors, respectively, in an individual manner, in particular with desired values for rotational speed and/or torque. In this, the driving torque of the adjustment drives can be limited to a limit value, the maximum moment for which the drives are dimensioned for instance. Furthermore, the control device is realised to recognise how the total driving torque is distributed over the individual drives, and how high the real rotational speed of the adjustment system is. In this, the control device changes the desired values for rotational speed or moment of the individual drives such that the adjustment system is traversed with the desired rotational speed. From a traversing request for the adjustment device, the control device can determine the driving torque which is to be applied by the drives in total, and distribute it to the different drives or their electric motors, respectively. Subsequently, the electric motors can be triggered accordingly. In this, the control is performed such that one or plural drives act driving (motive) and at least one drive acts braking (as a generator). By the control device, the really applied torque can be measured and the rotational speeds or desired torques, respectively, of the individual drives or electric motors, respectively, can be regulated correspondingly. For performing these tasks, the control device can have a suitable analysing device.
[0015] Besides to the electric motor, each of the adjustment drives can feature a gearbox, a planetary one in particular, and optionally a braking device (an electric brake for instance) for holding the corresponding electric motor. The electric motors may be asynchronous motors (3-phase current asynchronous motors). They can be triggered by frequency converters, for instance. The electric motors have usually rotors and corresponding stators. As a consequence, the operation of the electric motors in a defined sense of rotation or with a defined rotational speed means the sense of rotation and the rotational speed of the rotors of the electric motors.
[0016] It is possible that the electric motors of the different adjustment drives are operated in opposite senses of rotation. But it is particularly preferred to operate the electric motors operated at different rotational speeds in the same sense of rotation. This embodiment is based on the finding that it is sufficient for an effective tightening of the drives when one of the drives is in fact operated in the same direction as the remaining drives, but with a smaller rotational speed. In this way, a sufficient tightening is achieved in a manner which is particularly gentle for the drives. By pre-setting such different desired rotational speeds in the triggering of the electric motors of the adjustment drives, one of the electric motors is quasi in a lag with respect to the remaining motors, and provides the tightening in this way. In particular, there is a slippage between the electric motors. In doing so, all the electric motors of all the adjustment drives can be operated in the same sense of rotation.
[0017] A moment regulation is preferably performed such that the respective adjustment drive(s) or electric motor(s), respectively, do not exceed a preset desired driving torque, and that adjustment drive or electric motor, respectively, which is operated at another rotational speed, a smaller one in particular, acts only with a fraction of the desired driving torque against the driving action of the remaining adjustment drive(s) or electric motor(s), respectively. Thus, the counter-acting torque cannot damage the adjustment drives and is in the permanently sustainable range of the gearbox. As a consequence, curtailings of the lifespan have not to be feared. According to one embodiment, in the traversing of the adjustment device, the adjustment drive featuring the electric motor operated at a different rotational speed can apply a torque directed against the driving torque of the at least one other adjustment drive of 5 to 10% of the driving torque of the at least one other adjustment drive. For instance, when each drive applies a rated moment of 100 Nm, the electric motor or adjustment drive, respectively, which is operated at the lower rotational speed, can apply a counter-moment of 5 to 10 Nm. According to a further embodiment, there can be a difference in rotational speed of 20 to 100 rotations per minute (rpm) between the electric motor operated at a different rotational speed, a lower one in particular, and the electric motor of the other adjustment drive or adjustment drives, respectively.
[0018] In principle, the present invention can be applied to all the adjustment devices in which there are elasticities and a tightening is therefore desirable. However, in a manner particularly suited for practice, the component can be a machine house of the wind energy plant and the adjustment device an azimuth adjustment device. Then, the machine house of the plant can be rotated around the longitudinal axis of the plant by the adjustment device. In this way it is possible for the rotor of the plant to follow the wind, and to untwist the cable loop between machine house and tower from time to time. But it is also possible that the component is a rotor blade of the wind energy plant, and the adjustment device a blade pitch angle adjustment device. In this case, the blade pitch angle of the rotor blades of the plant can be adjusted through the adjustment device by rotating the rotor blades around their longitudinal axis.
[0019] According to one embodiment, the adjustment device can feature more than two adjustment drives, three or more adjustment drives in particular, each one of them having at least one electric motor. It is then possible that the electric motors of more than two adjustment drives, of all the adjustment drives of the adjustment device in particular, are operated in the same sense of rotation during the traversing of the adjustment device, and that the electric motor of at least one of the more than two adjustment drives is operated at a lower rotational speed than the electric motors of the other ones of the more than two adjustment drives. Thus, in this embodiment, one motor in particular of an adjustment drive is operated at a lower rotational speed than the electric motors of the remaining adjustment drives. In this, the electric motors of the other adjustment drives can be operated at the same rotational speed.
[0020] According to a further embodiment, the electric motor or the electric motors, respectively, of the other adjustment drive or the other adjustment drives, respectively, can be operated at the rated rotational speed for traversing the adjustment device. Thus, in this embodiment, the electric motors of all the adjustment drives in particular are operated at rated rotational speed, except that one having the lower rotational speed and acting as a generator through this.
[0021] At high loads acting against the traversing movement of the adjustment device, the rotational speed of the at least one electric motor operated at a lower rotational speed can be increased. Thus, in this embodiment, at strong wind acting against the sense of rotation, the electric motor operated with the lower rotational speed, but in the same sense of rotation as the remaining electric motors, can also be operated at rated rotational speed, in order to support the remaining drives in the traversing of the adjustment device against the wind. Thus, the electric motor operated at lower rotational speed represents a power- and moment reserve which can be requested when needed. The total driving torque of the drives of the adjustment device is dimensioned such that all the drives together can safely traverse with maximum moment against the maximum occurring loads. The control device can feature a load measurement device, a wind measurement device for instance. When a limit load is exceeded, the control device can then increase the rotational speed of the braking electric motor which effects the tightening.
[0022] In a standstill of the adjustment device, the electric motors of at least two azimuth drives can be triggered in opposite senses of rotation, but with a rotational speed not equal to zero, such that the adjustment drives do not exert any torque on the adjustment device altogether. Thus, in this case a tightening and a holding of the adjustment device is attained even in a standstill of the adjustment devices. As a consequence, the holding/service brake usually situated on the fast shaft of the drive train of the wind energy plant can be omitted, because the adjustment drives are permanently in the follow-up operation and fix the adjustment system at standstill. In particular, the electric motors of two different adjustment drives can be operated in opposite senses of rotation but with the same moment in this, and the electric motors of the remaining adjustment drives can be not operated at all (rotational speed zero).
[0023] Due to the tightening of the adjustment drives in the manner of the present invention, it is furthermore possible that during the traversing of the adjustment device, no detent torque is exerted on the adjustment device by a braking device. Instead, this detent torque can be replaced by the tightening of the drives. As a consequence, the traversing of the adjustment device proceeds in a damped way, and a reduced wear and less necessity of maintenance result from this. In addition, the total driving torque to be applied by all the drives in common can be dimensioned smaller than when a detent torque is provided in the traversing. With a sufficient driving torque of the adjustment drives, even the braking device usually providing the detent torque (in the case of an azimuth adjustment device the brake disc and the brake calipers) can be omitted in principle. Admittedly, for starting and maintenance purposes, and also for the case of a grid breakdown, a device for arresting and holding, respectively, must be provided for the adjustment device. In this, those loads must be taken as a base which act on a wind energy plant which is in the spinning operation. Such a holding device has not to arrest rigidly when this is not demanded for safety reasons, but it may slip through when a limit load is exceeded. Inasmuch as the adjustment device features a conventional brake device nevertheless, the same can be kept unactuated during the traversing of the adjustment device, the brake calipers kept in the opened condition for instance.
[0024] In order to make the wear of the adjustment drives uniform over their lifespans, electric motors of different adjustment drives are operated in an alternating manner at the other rotational speed, the lower one in particular. A change from one adjustment drive to another adjustment drive can be performed in particular after the decay of a parametrisable time, or after reaching a parametrisable number of traversing procedures of the adjustment device. Thus, a cyclic change between the drives with respect to their braking functions is possible. As the transition time between different adjustment drives, a point in time between two yawing processes can be used, in which the sum of all driving torques is zero. In particular, the adjustment drives can have the same driving torque at the rated rotational speed of the electric motors. However, as an alternative it is also possible to operate only the same drive or electric motor, respectively, with the lower rotational speed. For instance, the same can then have a smaller driving torque than the remaining (main-) drives.
[0025] Due to the lag with respect to the remaining motors, the electric motor operated at a lower rotational speed in the traversing of the adjustment device acts as a generator, whereas the remaining electric motors act motive. According to an embodiment particularly suited for practice, the electric energy, recovered from the electric motor operated at a lower rotational speed and acting as generator, can therefore be fed into an electric grid of the wind energy plant. For this purpose, a suitable feeding device may be provided. Thus, in this embodiment there is a recovery into the plant system of the energy consumed by tightening the adjustment drives.
[0026] The apparatus of the present invention can be suited for performing the method of the invention.
BRIEF DESCRIPTION OF THE SEVERAL FIGURES OF THE DRAWINGS
[0027] An example of the realisation of the present invention is explained in more detail by means of drawings in the following. Schematically shown is in:
[0028] FIG. 1 an azimuth adjustment system with an adjustment device according to the present invention according to a first embodiment, in a cross section.
[0029] FIG. 2 a depiction of the adjustment device according to the present invention, and
[0030] FIG. 3 a diagram for illustrating the function of the adjustment device according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated
[0032] As far as not indicated otherwise, equal reference signs designate equal objects in the figures. In FIG. 1 , an azimuth system of the wind energy plant with an adjustment device 16 according to the present invention is schematically shown, an azimuth adjustment device 16 in the depicted example. Of course, another adjustment system with another adjustment device, a blade pitch angle adjustment device for instance, could be provided as well. In the depicted example, the adjustment device 16 has three adjustment drives 18 , presently azimuth adjustment drives 18 , one of which can be recognised in FIG. 1 . The adjustment device 16 serves for rotating a machine house of the wind energy plant. In particular, a machine carrier 10 of the machine house of the plant, not depicted in detail, is shown. At the nacelle side, the machine carrier 10 carries in a per se known manner a not depicted generator and an also not depicted drive train with the rotor of the wind energy plant. In the example, the rotor features three rotor blades. The machine carrier 10 and with it the machine house are rotatably mounted on the tower 12 , which is depicted in cut-outs. The rotation of the machine house around the longitudinal axis of the tower 12 takes place in a per se known manner via an azimuth swing bearing 14 .
[0033] The azimuth drives 18 each have an electric motor 20 , triggered by means of a not depicted frequency converter in a per se known manner, presently a three-phase current asynchronous motor 20 . The electric motor 20 acts on a shaft, whose rotational axis is designated with 22 . The adjustment device 16 has furthermore a plural step planetary gearbox 24 . The electric motor 20 is positively connected to the fast shaft of the gearbox 24 acting as a torque converter. The slow output shaft 26 of the gearbox 24 features a pinion 28 , which meshes from the exterior with an outside-toothed azimuth pivot bearing 30 . A brake disc 32 is arranged on the azimuth bearing 30 at the outside in the depicted example, which is partly overlapped by brake calipers 34 . In the depicted example, the brake calipers are actuated hydraulically via a central hydraulic unit, which is arranged on the machine carrier 10 at the nacelle side. The brake disc 32 with the brake calipers 34 is a part of a braking device 31 . Furthermore, the azimuth adjustment device 16 has an electric holding brake 36 , assigned to each one of the adjustment drives 18 at a time, for holding the asynchronous motor 20 . The holding brake 36 has a brake disk 38 , connected to the fast shaft of the gearbox 24 , as well as brake calipers 40 acting on the brake disk 38 .
[0034] In order to rotate the machine house of the wind energy plant, the azimuth adjustment device 16 is traversed by actuating the azimuth adjustment drives 18 , and the electric motors 20 of the azimuth drives 18 in particular, with a defined rotational speed. Via the planetary gearbox 24 , this rotation movement of the electric motors 20 is transformed into a slower rotation movement of the slow shaft 26 . Through the movement of the shaft 26 , the pinion 28 is also moved in a corresponding manner. The same transfers its rotation movement to the toothing of the azimuth bearing 30 meshing with it. As a consequence, a rotation of the machine house around the longitudinal axis of the plant tower 12 takes place via the azimuth swing bearing 14 .
[0035] Furthermore, the azimuth adjustment device 16 has a control device 42 , which can trigger the electric motors 20 of the adjustment drives 18 of the adjustment device 16 via a line 44 . This is also depicted schematically in FIG. 2 . In particular, desired rotational speeds and/or desired torques can be preset to the electric motors 20 of the adjustment drives 18 by the control device 42 . In this, the respective driving torques applied by the adjustment drives 18 can be determined by the control device 42 . In a traversing request for the azimuth system, through an individual triggering of the electric motors 20 , the control device 42 can distribute the overall driving torque to be applied by the adjustment drives 18 over the drives 18 . In particular, for traversing the azimuth adjustment device, the electric motors 20 of two of the three adjustment drives 18 are triggered by the control device 42 into the same sense of rotation and to equal rotational speed in the depicted example. At the same time, the electric motor 20 of the third adjustment drive 18 is also operated in the same sense of rotation as the electric motors 20 of the remaining drives 18 , but with a lower rotational speed. This has the effect that the more slowly operated electric motor 20 , and with it the corresponding adjustment drive 18 , lags behind the two other electric motors 20 and adjustment drives 18 , respectively. Thus, a tightening of the drives 18 and an avoidance of undesired elasticities is achieved. Due to the tightening, a detent torque usually applied in the state of the art by the braking device 31 through the brake calipers 34 when the azimuth adjustment device 16 is traversed, is no more necessary.
[0036] Also, for instance in a standstill of the adjustment device 16 , the electric motors 20 of two adjustment drives 18 can be operated in opposite senses of rotation and at equal rotational speed, the electric motor 20 of the third adjustment drive 18 being no more actuated in doing so. In the depicted example, the adjustment drives 18 exert the same driving torque at equal rotational speed of their electric motors 20 . Insofar, holding the azimuth system is achieved in this embodiment even in a standstill of the adjustment device 16 . The braking device 31 is not obligatorily necessary also before this background. However, it may be provided for purposes of maintenance and starting.
[0037] The result of the triggering of the adjustment drives 18 according to the present invention is to be explained by means of the diagram depicted in FIG. 3 . In the diagram, the torque M is plotted over the time t. The curve 1 describes the driving torque applied to the azimuth swing bearing by the three adjustment drives 18 in common. The curve 2 describes the constant driving torque applied in total by the two adjustment drives 18 operated at rated rotational speed and in the same sense of rotation. The curve 3 describes the driving torque applied by the electric motor 20 of the third adjustment drive 18 .
[0038] In FIG. 3 , it can be recognised that the common torque applied by the drives 18 operated at rated rotational speed is constant (curve 2 ). From on the points in time t=0 up to t 1 , the electric motor 20 of the third adjustment drive 18 is operated at a lower rotational speed than the electric motors 20 of the two other adjustment drives 18 . Correspondingly, a braking action and thus a negative driving torque M 3 is exerted by the more slowly operated electric motor 20 or the corresponding adjustment drive 18 , respectively. Correspondingly, the driving torque applied by the three adjustment drives 18 in common (curve 1 ) decreases also for M 3 between the points in time t=0 and t 1 . In the point of time t 1 , strong wind loads acting against the traversing direction of the azimuth system are detected by the control device 42 , and in particular by a wind measurement device associated to the same. In order to support the two adjustment drives 18 traversing at rated rotational speed, the rotational speed of the electric motor 20 operated at lower rotational speed is therefore increased by the control device 42 . In particular, there is a linear increase of the rotational speed and with this of the driving torque exerted by this adjustment drive 18 from on the point in time t 1 up to the point in time t 2 . In the point in time t 3 , the transition of the corresponding electric motor 20 from the generator operation to the motive operation takes place. The driving torque applied by all the drives in common (curve 1 ) increases correspondingly. In the point in time t 2 , the rotational speed of the electric motor 20 of the originally more slowly operated adjustment drive 18 is increased no more, but is kept on a constant level. Correspondingly, even the driving torque applied by all the drives in common (curve 1 ) remains on this increased moment level. In this way, it can be safely traversed even against strong wind loads.
[0039] By way of example, the following table shows the modes of operation of the three adjustment drives 18 in different load situations:
[0000]
“Load case” of the
Azimuth
Azimuth
Azimuth
azimuth system
drive 1
drive 2
drive 3
Starting with counter-
Driving
Driving
Driving
moment from the wind
Travelling with counter-
Driving
Driving
Driving or
moment from the wind
braking
Stopping with counter-
Braking
Braking
Driving or
moment from the wind
braking
Starting with driving
Driving
Driving
Braking
moment from the wind
Travelling with driving
Driving or
Driving or
Braking
moment from the wind
braking
braking
Stopping with driving
Braking
Braking
Braking
moment from the wind
[0040] After the decay of a parametrisable period of time, another one of the three electric motors 20 of the adjustment drives 18 can be used for the tightening by the control device 42 , for instance be operated at a lower rotational speed. By such a cyclic change between the adjustment drives 18 , the wear is made more uniform over their lifespan. Furthermore, a feeding device not depicted in more detail may be provided, by which the energy recovered by the electric motor 20 , operated at the lower rotational speed in the traversing of the adjustment devices 16 and acting as a generator, is fed back into the electric grid of the wind energy plant.
[0041] Due to the tightening achieved according to the present invention, the present invention invites its use at plant locations in particular which are exposed to a strong and changing wind.
[0042] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0043] Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
[0044] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The invention is related to a method for rotating a component of a wind energy plant by traversing an adjustment device, wherein the adjustment device comprises at least two adjustment drives, each one thereof having at least one electric motor, for traversing the adjustment device, and wherein during the traversing of the adjustment device, the electric motor of at least one of the at least two adjustment drives is operated at another rotational speed than the electric motor of at least one other of the at least two adjustment drives. Furthermore, the invention is related to a corresponding device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved method of drilling around the casing pipe of an old well in order to regenerate the old well that cannot maintain its designed pumping rate. For the purpose of this invention, "regeneration" refers to replacing the existing casing and well screen with new ones.
2. Prior Art
Japanese Patent Bulletin No. 6-173567, the publication of the patent application by the present applicant, discloses a method of regenerating an old well. Also, the Bulletin discloses the DONUT drill bit and the cutting apparatus for the casing of an old well, which are used with such a method. FIG. 5 of the accompanying drawings is a copy of FIG. 1 of the above cited patent document. Note that the parenthesized identification numbers in FIG. 5 are those found in the original drawing whereas numbers without parentheses are those relevant to the present invention.
The cited patent document describes how packing gravel (21) and formation material surrounding the casing pipe (6) of an old well is drilled by the circulating pressurized drilling mud water which is jetted from the lower end of a DONUT drill bit in sufficient quantity, but does not mention the mechanism for jetting the pressurized drilling mud water. The mechanism may be clearly understood from the description of the DONUT drill bit, which explains how a number of nozzle pipes (5) are fixed radially on the outer surface of drill pipe (2), parallel with its axis, throughout the entire length of the drill pipe, and each nozzle pipe (5) is connected to the mud water inlet chamber (4) at the top thereof and to a nozzle unit (11) at the bottom.
The fact that the DONUT drill bit used in the above cited method features independent nozzle pipes located on the drill pipe surface as passages for the pressurized drilling mud water makes the DONUT drill bit itself complicated and hence inevitably costly. Consequently, a method of regenerating an old well involving the use of such a DONUT drill bit entails complicated operations which make the entire regenerating job rather expensive.
It is, therefore, an object of the present invention to provide a method of drilling around an existing casing pipe in order to regenerate on old well.
Another object of the present invention is to provide a method of drilling by using a drill pipe that has neither nozzle pipes nor double walls, but is designed to use the existing casing pipe for circulating the pressurized drilling mud water.
Still another object of the present invention is to provide a method of drilling by jetting the pressurized mud water from the lower extremity of a drill pipe in order to enhance the drilling effect together with the drill cutters which are integrated into the lower extremity of the drill pipe.
SUMMARY OF THE INVENTION
According to the invention, the above objects are achieved by providing a method of drilling packing gravel and formation materials around an existing casing pipe in order to regenerate an old well. The method comprises the steps of sequentially filling the inside of the casing pipe of the old well with mud water, connecting a drill pipe, which has an inside diameter greater than the outside diameter of the existing casing pipe of the old well and is furnished with a drill bit consisting of drill cutters and nozzles at the lower extremity, to a water swivel, setting the drill pipe in axial alignment with the existing casing pipe, rotating and lowering the drill pipe while sending the pressurized drilling mud water through the annulus between the drill pipe and the casing pipe, drilling the packing gravel and formation materials encountered surrounding the casing pipe with the drill bit, moving the cuttings up to the surface by the drilling mud water which ascends the annulus between the drill pipe and the borehole wall at a velocity greater than the descending velocity of the cuttings, separating the cuttings from the drilling mud water in a mud pit, and then circulating the drilling mud water in the annulus between the pipes. The drill pipe is an ordinary pipe that has neither nozzle pipes nor double walls, and may be jointed to another pipe in an ordinary manner to make a drill string conforming to the depth to be drilled.
In order to regenerate an old well, the second through fourth steps of operation described in the cited patent document have to be followed after the above described first step.
In the second step of the cited patent document, the existing casing pipe is cut off at a depth near the top of packing gravel which is drilled in the first step and pulled out to the surface. The sequence of the first and second steps is repeated until the casing pipe is removed out to a predetermined depth.
Then, in the third step, the tightly compacted formation materials of the borehole wall in the aquifer zone of the old well are scraped to an appropriate extent with a reaming tool and taken out to the surface. This third step may be omitted as described in the cited patent document.
Finally, in the fourth step, installation of new casing pipe with new well screen and well development are carried out in the same manner as used in the common well construction.
Each of the aforesaid nozzles, which are fabricated in the flange part of the lower extremity of the drill pipe with their axis running downward from the inside toward the outside of the drill pipe, has a smaller opening diameter on the outside than the opening diameter on the inside which enhances the drilling effect together with drill cutters integrated therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lateral, sectional view of an old well with an existing casing pipe, illustrating the method of drilling packing gravel around the casing pipe in accordance with the invention.
FIG. 2 is a partial, sectional view of the lower extremity of the drill pipe designed for use in accordance with the method of the invention.
FIG. 3 is an end view of the drill pipe of FIG. 2.
FIG. 4 is an enlarged partial, sectional view of the drill pipe of FIG. 2, showing the nozzle in detail.
FIG. 5 is a copy of FIG. 1 of the drawings, accompanying document of Japanese Patent Bulletin No. 6-173567.
FIG. 6 is a copy of FIG. 5 of the drawings, accompanying document of Japanese Patent Application No. 6-309643.
FIG. 7 is a copy of FIG. 6 of the drawings, accompanying document of Japanese Patent Application No. 6-309643.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The casing pipe of an old well is filled with drilling mud water in advance. With this preliminary arrangement, the drilling mud water flows out of the well screen to the packing gravel and aquifer to some extent and the clay material of the drilling mud water seals the pores of the aquifer so that any further intrusion of the pressurized drilling mud water into the aquifer can be prevented during the drilling operation.
Then, a drill pipe jointed to the water swivel is set on the old well in axial alignment with the casing pipe and connected to the lifting and rotating equipment.
The drill pipe is rotated and lowered while the drilling mud water is delivered under pressure into the drill pipe by mud pump from mud tank through water swivel. The drill pipe drills the packing gravel and formation around the casing pipe of the old well by means of the drill cutters fitted to the bottom thereof, while the pressurized mud water flows down through the annulus between the existing casing pipe and the drill pipe until it is eventually jetted from the bit nozzles toward the bottom of the drilled hole. The pressurized drilling mud water goes up through the outer annulus between the drill pipe and the borehole wall at a velocity greater than the descending velocity of the cuttings, and delivers cutting to a mud pit at the surface. The drilling mud water returned to the surface is separated from earth particles sized larger than silt, and circulated again by the mud pump.
When the drill bit encounters the aquifer, some amount of the pressurized drilling mud water is lost in the aquifer. However, any formation pores passing the drilling mud water are immediately filled with fine and colloidal particles contained in the drilling mud water, further loss of the drilling mud water is prevented, and the drilling operation can be continued without any problem.
The drilling mud water velocity in the annulus between the two pipes can be set at a desired level. The ascending velocity of the drilling mud water in the annulus between the drill pipe and borehole wall is normally selected at a rate of 0.4 m/sec. to 0.5 m/sec.
The friction loss of the circulating drilling mud water increases with the depth of the well. If the loss is not so high as to cause any problem on the pressure allowance of the mud pump, it does not affect drilling operation. This is the same as in the operation of an ordinary mud rotary drilling machine.
Subsequently, aforesaid second through fourth steps are carried out for the regeneration of an old well. Each step is similar to those described in detail in the cited patent document.
The second step comprises the following operations. A casing pipe cutting device consisting of the cutting nozzle and inside slip is lowered with wire in the casing pipe and placed in a predetermined position. Then, the wire suspending the cutting device is raised so that the inside slip is moved upward by means of a wedge part and firmly settled on the inner surface of the casing pipe. By the inside slip tightly holding the casing pipe, the casing pipe cutting nozzle itself is also firmly positioned and aligned with the casing pipe. Pressurized water is sent to the cutting nozzle and the rotating shaft of the cutting device is rotated by an electric motor. With this rotation of the shaft, an arm of the cutting device is rotated and in turn the cutting nozzle is also horizontally rotated, shooting a water jet against the inner surface of the casing pipe and cutting the pipe. When the casing pipe is completely cut, the cutting device is lifted up together with the cut portion of the casing pipe to the surface.
Whenever necessary, the sequence of the first and second steps is repeated until the predetermined section of the casing pipe in the old well is completely removed.
Then, in the third step, by using an ordinary direct rotary well drilling machine with a reaming tool (a reaming bit with extendable blades), the borehole wall in the aquifer zone of the old well is scraped. The scraped cuttings are removed out to the surface. This third step may be omitted if it is not necessary for the regeneration of the old well.
Finally, in the fourth step, new casing is installed in the borehole of the old well and the annular space around the well screen section is packed with gravel of appropriate grain size. And, after carrying out common well development, the entire process of regenerating the old well will be finished.
If the top of an old well casing is held open and the inside of the casing pipe is filled with mud water from the initial stages of the operation of drilling for the old well regeneration, the mud water gradually enters into the aquifer and pores of the aquifer may become filled with fine and colloidal particles. Then, no further mud water may be lost into the aquifer when the drill pipe encounters the aquifer.
Since each of the aforesaid nozzles located in a flange portion of the drill bit features its axis running downward from the inside toward the outside of the drill pipe and its opening with the outside diameter smaller than the inside, they can effectively eject the pressurized drilling mud water, which is forced down in the annulus between the existing casing pipe and the drill pipe, against the bottom of the hole in order to cool the drill cutters and remove the cuttings from the bottom of the hole, and can enhance the drilling capability of the drill cutters fitted below.
Now, the present invention will be described further by referring to the accompanying drawings.
In the drawings, reference number 1 denotes a drill pipe which has an inside diameter greater than the outside diameter of the existing pipe of the old well. The six drill cutters 3 which are integrated into the lower extremity of the drill pipe are arranged radially, regularly spaced apart. Six nozzles 4 are arranged between the adjacent drill cutters in an alternate manner. The number of drill cutters and nozzles may be altered if necessary.
The drill pipe 1 is then connected to a water swivel 5 and located in an axial alignment with the existing casing pipe 2 of the old well. This procedure may be carried out in any manner selected from a number of known methods including the usage of a traveling block 6 with a hook 7, and a hoisting bail 9 suspended from a mast or derrick (not shown) as illustrated in FIG. 1 or alternatively, the usage of a lift mechanism 10 and a rotary drive mechanism 11 as illustrated in FIGS. 6 and 7, which correspond to FIGS. 5 and 6 in the above cited document, Japanese Patent Application No. 6-309643, or a combination thereof.
While being rotated, the drill pipe 1 is lowered around the existing casing pipe 2 of the old well while the drilling mud water is delivered under pressure into the drill pipe by the mud pump from the mud tank through the water swivel. The drill pipe drills the packing gravel and formation around the casing pipe by means of the drill cutters 3 fitted to the lower extremity thereof, while the pressurized mud water flows down through the annulus 12 between the existing casing pipe 2 and the drill pipe 1 until it is eventually jetted from the bit nozzles 4 toward the bottom of the drilled hole. The pressurized drilling mud water goes up through the outer annulus 14 between the drill pipe 1 and the wall of the drilled hole 13 at a velocity greater than the descending velocity of the cuttings, and delivers the cuttings to a mud pit 15 at the surface.
The circulation of the mud water is well-known. The mud pit 15 is connected to the annulus 14 outside the drill pipe. A mud tank 17 receives the mud water pumped up by the sand pump 16 in the mud pit 15. The mud pump 18 circulates the mud water from the mud tank 17 to the drill pipe 1 through the water swivel 5.
The mechanism for rotating and pulling up the drill pipe 1 is similar to the one illustrated in FIGS. 7 and 8 which correspond to FIGS. 5 and 6 in the above cited document, Japanese Patent Application No. 6-309643.
As the drill pipe 1 is lowered and rotated, the drill cutters 3 fitted at the lower extremity thereof drill the packing gravel and formation around the casing pipe 2 of the old well. At the same time mud water is circulated under pressure into the drill pipe 1 by the mud pump 18 from the mud tank 17 through the water swivel 5. The pressurized drilling mud water flows down through the annulus 12 between the existing casing pipe 2 and the drill pipe 1 until it is eventually jerred out from the bit nozzles 4 toward the bottom of the drilled hole. The pressurized drilling mud water carrying the excavated cuttings flows up through the outer annulus 14 between the drill pipe 1 and the wall of the drilled hole 13 at a velocity greater than the descending velocity of the cuttings and goes into a mud pit 15 at the surface. The mud water is separated therein from earth particles sized larger than silt, pumped up by the sand pump 18 to the mud tank 17, and then circulated again by the mud pump 18 to the drill pipe 1 through the water swivel 5.
As the drill pipe 1 is further lowered and eventually hits the packing gravel 19, the drill cutters 3 and the mud water jetted from the bit nozzles 4 drill the packing gravel 19 and formation around the existing casing pipe 2. The drilled cuttings (gravel and other formation materials) are carried and displaced into the mud pit 15 at the surface by the mud water which flows up through the annulus 14 between the drill pipe 1 and the wall of the drilled hole 13 at a velocity greater than the descending velocity of the cuttings. The cuttings settle in the mud pit 15.
When drilling the packing gravel 19 is completed, the drill pipe 1 is pulled out of the drilled hole.
The aforesaid second through fourth steps of operation follow after completed the procedure of the present invention and not directly relate to the present invention. These steps, therefore, will not be described here any further. Reference should be made to the above cited document, Japanese Patent Bulletin No. 6-173567.
The top of the casing pipe 2 of the old well is open during the operation in accordance with the method of the invention. Thus, if the casing pipe 2 of the old well is filled with mud water in the initial stages of the operation of drilling the old well for regeneration, some drilling mud water may flow out of the well screen 2' to the packing gravel and aquifer 20. The fine and colloidal particles contained in the drilling mud water seal the pores in the aquifer to some extent so that any further intrusion of the pressurized drilling mud water to the aquifer can be prevented when the drill pipe 1 encounters the aquifer.
As illustrated in FIG. 4, the above described nozzles 4 run through a flange part 21 located at the lower extremity of the drill pipe 1 with their axis running downward from the inside toward the outside of the drill pipe 1. Because the opening (dia. 1) on the outside of the nozzle is smaller than the opening (dia. 2) on the inside the pressurized mud water through the annulus 12 between the casing pipe 2 of the old well and the drill pipe 1 can be ejected against the bottom of the drilled hole 13 of the old well through the nozzles 4 to cool the drill cutters 3 and excavate and remove the cuttings from the hole bottom, and can greatly enhance the drilling capability of the drill cutters fitted below.
Advantage of the Invention!
As described above in detail, if the inside of the existing casing pipe is filled with the drilling mud water from the initial stages of drilling the old well for regeneration, some drilling mud water flows in the aquifer through the well screen of the casing pipe and the packing gravel and closes pores of the aquifer with fine and colloidal particles. Therefore, further occurance of the drilling mud water loss is prevented and the drilling operation can be continued without any problem.
By using the annulus between the casing pipe of the old well and the drill pipe as a flow path for the pressurized mud water, the nozzle pipes in the known method can be omitted to simplify the operation of drilling around the existing casing pipe.
The pressurized mud water flows down through the clearance between the casing pipe of the old well and the drill pipe and is jetted toward the bottom of the drilled hole from the bit nozzles. This effectively cools the drill cutters and enhances the drilling effect together with the drill cutters which are integrated in the lower extremity of the drill pipe.
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A method of drilling the packing gravel and formation materials around an existing casing pipe in order to regenerate an old well. The method comprises the steps of sequentially filling the inside of the casing pipe of the old well with mud water, connecting drill pipe, which has an inside diameter greater than the outside diameter of the existing casing pipe of the old well and is furnished with a drill bit consisting of drill cutters and nozzles at the lower extremity, to an upper water swivel, setting the drill pipe in axial alignment with the existing casing pipe, rotating and lowering the drill pipe while sending pressurized drilling mud water through the annulus between the drill pipe and casing pipe, drilling the packing gravel and formation materials encountered surrounding the casing pipe with the drill bit, moving the cuttings up to the surface by the drilling mud water which ascends the annulus between the drill pipe and the borehole wall at the velocity greater than the descending velocity of the cuttings, separating the cuttings from the drilling mud water in a mud pit, and then circulating the pressurized drilling mud water in the annulus between the pipes for re-circulation.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a crane control for a crane arranged on a ship having a load moment limitation system which determines a maximum permitted payload. The load moment limitation system can in this respect either take account of the maximum permitted payload in an automated manner in the control of the crane or can output it to the user so that he can take account of the maximum permitted payload in the control of the crane.
[0002] With a crane arranged on a ship, in addition to the usual factors which are taken into a load moment limitation system such as the outreach of the crane, it must furthermore be taken into account on the determination of the maximum permitted payload that the current wave movement can also have effects on the maximum permitted payload. Previous load moment limitation systems in which a significant wave height or a sea state is determined according to which a corresponding payload curve has to be selected in crane operations are subject to great uncertainties in this respect.
SUMMARY OF THE INVENTION
[0003] It is therefore the object of the present invention to provide a crane control having a load moment limitation system which allows a more reliable determination of the maximum permitted payload of a crane arranged on a ship.
[0004] This object is achieved in accordance with the invention by a crane control in accordance with the description herein.
[0005] The present invention in this respect shows to a crane control for a crane arranged on a ship having a load moment limitation system which determines a maximum permitted payload. In this respect, the load moment limitation system is in communication with a measuring unit for measuring the movement of the ship and determines the maximum permitted payload on the basis of data of the measuring unit.
[0006] Whereas in accordance with the prior art a conclusion was drawn on the movement of the boom tip from the significant wave height, which can anyway only be determined with difficulty, and the maximum payload limit was in turn determined from said movement so that e.g. the onflow direction and the ship type were not able to be taken into account, the ship movements are now detected by sensors and are used for determining the maximum payload of the crane. The technical limits can thus be utilized in a manner which better satisfies the situation by the measurement of the real ship movement and thus higher payloads can be achieved with an unchangingly high reliability.
[0007] In particular an inertia measuring system is used as the measuring unit in this respect from whose data the movement of the boom tip of the crane can be determined at least in the vertical direction on the basis of the ship's movement. The measuring unit can in this respect in particular include a gyroscope and/or an accelerometer and/or an electronic inclinometer. The load moment limitation system advantageously determines a speed and/or acceleration of the boom tip by the evaluation of data of the measuring unit and determines the maximum permitted payload from this. In this respect, at least the speed and/or acceleration of the boom tip in the vertical direction is advantageously determined and the maximum permitted payload is determined from this. The determination of the vertical movement of the boom tip is in this respect usually sufficient to determine the maximum permitted payload since this represents the decisive factor in the movement of the boom tip with respect to the payload.
[0008] In the crane control in accordance with the invention, the determination of the speed and/or acceleration of the boom tip advantageously takes place on the basis of data of a preceding specific time period. The determination thus always takes place via a specific concurrent time window so that current data are always used for determining the speed and/or acceleration or for determining the maximum permitted payload.
[0009] Furthermore, provision can be made in the present invention that an initializing of the load moment limitation system using currently measured values takes place at the start of work. The starting results are in this respect always based on values since the restart of the control, whereas old data are not taken into account for the calculation.
[0010] The load moment limitation system advantageously determines a tip speed and/or tip acceleration of the boom tip over a specific time period. This can then be used for determining the maximum permitted payload.
[0011] The determination of the tip speed and/or tip acceleration in this respect advantageously takes place via a filtering algorithm which evaluates the measured data of the measuring unit.
[0012] Further advantageously, the load moment limitation system forms a mean value of the speed and/or acceleration of the boom tip over a specific time period. The mean value formation in this respect advantageously takes place in this respect over an upper part region of the speeds and/or accelerations determined by the measuring unit. An averaged tip speed and/or tip acceleration hereby result(s). For example, the mean value of the upper third of the measured speeds and/or accelerations can in this respect be determined in accordance with the invention.
[0013] Further advantageously, the maximum permitted payload is read out of a table or of a look-up table in accordance with the invention with reference to a speed value and/or acceleration value determined from the data of the measuring unit. The maximum permitted payloads for different speed values and/or acceleration values can therefore be stored in the crane control in accordance with the invention in the form of a table and can then be read out in accordance with the values determined. The table can naturally be a multidimensional table so that further values can naturally also be taken into the interrogating of the maximum permitted payload in addition to the speed values and/or acceleration values. The outreach of the crane can in particular still be taken into the interrogating of the table in this respect. Alternatively, the payload can also be calculated online. To the extent that reference is made to the reading out of tables in the following description, an online calculation can alternatively also respectively be carried out here.
[0014] In a first embodiment of the present invention, the measuring unit can be arranged at the crane tip. The measuring unit can thus directly measure the movement of the crane tip by the wave movement of the ship. The measuring unit is in this respect in particular equipped so that it can determine the movement of the crane tip in the vertical direction, in particular the speed and/or acceleration and/or of the crane tip in the vertical direction. The crane control advantageously in this respect has an evaluation unit which calculates the movements of the boom tip produced by the crane movement from the total movement measured by the measuring unit.
[0015] Furthermore, a determination of the speed and/or acceleration of the boom tip for a specific boom position can take place by conversion of data of a measuring unit not arranged in this position. In this respect, a position for which the maximum payload should be determined no longer has to be moved to by the boom.
[0016] Provision can furthermore be made in accordance with the invention that a measuring unit is arranged at the tower of the crane or at the ship, with the load moment limitation system determining the speed and/or acceleration of the boom tip by converting the data from the measuring unit. A geometrical model of the crane is advantageously used for this purpose. Further advantageously, data on a current and/or a virtual position of the boom tip are in this respect taken into the calculation.
[0017] Provision can advantageously be made in accordance with the present invention that the determination of the speed and/or acceleration of the boom tip takes place for a boom position which can be input by the user. The crane control in accordance with the invention therefore in particular includes a user dialog in which the user can input a boom position for which then the maximum permitted payload is determined. The determination of the speed or of the acceleration is thus possible for any desired position of the boom tip without having to move to it.
[0018] If a measuring unit is used which is not arranged at the crane tip, it advantageously determines the speed and/or acceleration in all three spatial directions. The vertical speed and/or acceleration of the boom tip decisive for the payload can then be calculated from the measured values of this measuring unit. This vertical movement is then taken into the determination of the maximum permitted payload. The two named measuring units can advantageously also be combined.
[0019] Horizontal influences can advantageously additionally be taken into account. They can be based on an inclined position of the ship resulting from the load state or from a pre-trim. Dynamic horizontal deflections of the load caused by relative horizontal movements of the installations (ship with crane, ship where the load decreases and increases) are also taken into account here. In this respect, the horizontal influences can be measured or calculated. The values can be taken into account in the payloads by tables or by online calculation.
[0020] Provision can furthermore be made that the load moment limitation system in accordance with the invention is in communication with a second measuring unit which determines the movement of a further ship, with the load moment limitation system additionally making use of data of the second measuring unit for determining the maximum permitted payload. This embodiment of the crane control in accordance with the invention can in particular be used when a load should be placed on a further ship or should be taken up by it. In this case, the movement of the this further ship is also a factor which has to be taken into account in the maximum permitted payload. This is effected in accordance with the invention by a second measuring unit which is arranged on the further ship.
[0021] The evaluation of the data of the second measuring unit can in this respect take place in the same manner as for the data of the first measuring unit. In this respect, in particular a tip speed and/or tip acceleration of the further ship can be determined. A mean value of the speed and/or acceleration over a specific time period can advantageously be formed for this purpose. The mean value formation in this respect advantageously takes place over an upper part region of the speeds and/or accelerations determined by the measuring unit. A filtering of the measured data can furthermore previously take place.
[0022] The crane control in accordance with the invention advantageously has an output unit which outputs the maximum payload calculated by the load moment limitation system. It is in this respect advantageously an optical output unit, in particular a display unit. The output can additionally or alternatively also take place to the crane control which takes it into account automatically in the control of the crane.
[0023] Provision can in this respect advantageously be made that the output of the maximum permitted payload for a specific boom position is possible. Such a boom position can advantageously be input by the user in this respect.
[0024] Alternatively or additionally, provision can be made that the maximum permitted payload is output as a payload curve.
[0025] In addition to the crane control, the present invention furthermore includes a crane having a crane control in accordance with the invention. It is in particular a boom crane in this respect. It is further advantageously a revolving tower crane—such as a revolving boom crane, offshore crane, ship crane or a non-revolvable luffable frame gantry crane—having a tower which is rotatable about a vertical axis of rotation and at which a boom is arranged. The crane control in this respect advantageously controls the hoisting gear of the crane in accordance with the invention. The crane in accordance with the invention is in this respect arrangeable or arranged on a ship.
[0026] In addition to the crane control and the crane, the present invention furthermore includes a ship having a crane in accordance with the invention which is accordingly equipped with a crane control in accordance with the invention.
[0027] The present invention furthermore includes a method for operating a crane arranged on a ship in which a maximum permitted payload is determined. Provision is advantageously made for this purpose that a movement of the ship is measured and the maximum permitted payload is determined on the basis of the measured movement. The determination of the maximum permitted payload in this respect advantageously takes place such as was already described above with respect to the crane control. In this respect, a speed and/or acceleration of the boom tip, in particular in the vertical direction, is in particular advantageously determined by means of the measured data and the maximum permitted payload is determined from it.
[0028] The present invention furthermore includes a program, in particular a program stored on a data carrier, for implementing a method such as was presented above on a crane control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The present invention will now be presented in more detail with reference to embodiments and to drawings.
[0030] There are shown:
[0031] FIG. 1 an embodiment of a ship in accordance with the invention with a crane in accordance with the invention having a control unit in accordance with the invention;
[0032] FIG. 2 a schematic diagram of a first embodiment of a crane control in accordance with the invention;
[0033] FIG. 3 an input and output unit for a crane control of a second embodiment of the present invention;
[0034] FIG. 4 an output unit for a crane control of a third embodiment of the present invention;
[0035] FIG. 5 a schematic diagram of a fourth embodiment of a crane control in accordance with the invention;
[0036] FIG. 6 a schematic diagram of a fifth embodiment of a crane control in accordance with the invention; and
[0037] FIG. 7 a schematic diagram of a sixth embodiment of a crane control in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIG. 1 shows an embodiment of a ship 1 in accordance with the invention. The ship 1 in this respect has a crane 3 which is equipped with a crane control in accordance with the invention. In the embodiment, it is in this respect a revolving tower crane having a tower 5 which is rotatably arranged about a vertical axis of rotation via a slewing gear 6 on a tower base 4 . A boom 7 is upwardly and downwardly luffably arranged about a horizontal axis of rotation at the tower 5 . The hoist rope 8 is in this respect guided over the tip 10 of the boom 7 . The crane in this respect in particular has a lifting drive for moving the hoist rope 8 via which a load suspended at the crane hook 9 can be raised. Furthermore, a further ship 2 is shown in FIG. 1 on which the load can be placed or from which the load can be raised.
[0039] As drawn in FIG. 1 , the wave movement generates a movement of the ship and thus a movement v C of the tip 10 of the boom and thus of the load. The wave movement equally generates a movement v D of the further ship and thus of the destination. The movements of the crane generated by the wave movement have an effect on the maximum permitted payload (SWL=safe work load). In accordance with the invention, the maximum payload of the crane suitable for the situation is determined with reference to measured values which are obtained by a measuring unit for measuring the movement of the ship 1 . The ship's movements detected by the sensors are in this respect processed by means of filtering algorithms in order thus to determine the vertical boom tip speed and/or vertical boom tip acceleration. The maximum payload of the crane suitable for the situation can subsequently be calculated using this speed and/or acceleration.
[0040] The measurement of the real ship's movement on the open seas in this respect allows the technical limits to be exploited better since the maximum payload can be determined substantially more reliably via the transmitted real movement of the boom tip in the vertical direction than by a method in accordance with the prior art.
[0041] An inertia measuring unit is advantageously used as a measuring unit MU. It can in particular include a gyroscope and/or an acceleration encoder or accelerometer and/or electronic inclinometers. In FIG. 1 , three possible different positions for such a measuring unit are now given which can be used both in combination and individually in each case in accordance with the invention.
[0042] MU 1 : Arrangement of the measuring unit MU 1 at the boom tip
[0043] MU 2 : Arrangement of the measuring unit MU 2 at the tower of the crane or at the ship
[0044] MU 3 : Arrangement of the measuring unit MU 3 on a further ship/barge
[0045] The first two positions for the arrangement of a measuring unit can in this respect be used alternatively or simultaneously to determine the movement of the boom tip on the basis of the movement of the ship 1 . The third arrangement option of a measuring unit serves to determine the movement of a further ship 2 on which the load should be placed down or from which the load should be taken up.
[0046] If instead of a further ship 2 a fixed installation is used, for example a platform, the third measuring unit MU 3 is not required. The vertical speed v D can rather then be assumed to be zero.
[0047] The vertical speed v C in the boom tip or the acceleration of the boom tip can in contrast be measured directly by the MU 1 and/or can be calculated from the values measured by the MU 2 .
[0048] The evaluation of the measured values will now be explained in more detail in a first embodiment in which the determination of the maximum payload is determined with reference to a vertical tip speed v C . In this respect, the meaned vertical speed of the current position of the crane tip is determined by recording the movement of the boom tip by means of the measuring unit MU 1 and subsequent statistical evaluation over a specific time window. This vertical speed and the outreach then determine the maximum payload.
[0049] FIG. 2 in this respect shows a schematic flowchart of the evaluation: The data for the movement of the boom tip measured by the measuring unit 20 are in this respect first filtered via a filtering algorithm 21 and the current vertical speed v C is determined from these. The position of the crane boom which is taken from the crane control in step 25 is in this respect advantageously taken into the algorithm 21 for calculating the vertical speed v C of the boom tip from the measured data of the measuring unit 20 . In step 22 , the mean value of the upper third of the measured speeds v C is then determined over a specific time window.
[0050] The tip speed and the outreach of the crane boom determined in step 22 are then used in step 23 to determine the maximum payload. In this respect, the maximum payload is read out of a corresponding table with reference to the values for the tip speed and for the outreach. The output of the maximum payload SWL thus determined then takes place in step 30 in a user interface.
[0051] To increase the comfort for the user, the determination of the vertical speed v C of the boom tip can take place for any desired working point without this point first having to be moved to by the crane. The second measuring unit MU 2 can be used for this purpose. In this respect, any desired boom tip position can be moved to virtually via an input of the user. The vertical boom tip speed v C for the virtual working point of the boom tip can now be calculated from the data determined by the measuring unit 2 . For this purpose, only the known geometry of the boom tip with respect to the position of the second measuring unit MU 2 has to be used.
[0052] The evaluation can in this respect take place as shown in FIG. 2 , with now the filtering algorithm 21 , however, carrying out the conversion of the data from the measuring unit 20 not arranged at the crane boom tip by means of virtual data on the position of the crane boom.
[0053] It is in this respect naturally possible to use both a first measuring unit MU 1 at the boom tip and a second measuring unit MU 2 at the tower or at the ship.
[0054] FIG. 3 in this respect shows an input/output unit via which any desired boom tip position can be moved to virtually. In this respect, the slew angle can be converted via the input mask 31 ; the radius via the input mask 32 . The input can in this respect take place, for example, via a keyboard and/or virtual slider at a monitor or touch screen. The user interface now outputs the vertical tip speed for the set virtual position in the display 33 and the maximum payload SWL resulting from this in a display 34 .
[0055] Alternatively or additionally, a display of the maximum payloads for the total working range can take place e.g. in the form of a payload curve. It must be taken into account in this respect that the maximum vertical speeds and thus the maximum permitted payloads for different slew angles of the crane can differ since the wave movement can, for example, result in a stronger movement of the ship in the transverse direction than in the longitudinal direction.
[0056] In order nevertheless to be able to give a payload curve which is valid for any desired slew angle of the crane, the following procedure can be followed:
[0057] First, the maximum vertical speed v C is calculated for N different slew angles over the total outreach range. In a second step, the maximum payloads for the different slew angles are determined herefrom in dependence on the radius. The representation now takes place by projection of the maximum payloads for the different slew angles into a single graphic. Finally, the minimum can then be calculated over all slew angles and this is then represented as a maximum possible SWL in the form of a payload curve.
[0058] In this respect, in FIG. 4 an embodiment of such a display is shown in which a plurality of payload curves 35 are combined in one representation for different slew angles. Alternatively or additionally, the display of the Minimum can also be provided over all payload curves.
[0059] In all embodiments of the present invention, a new initializing of the determining of the movement of the boom tip takes place after a restart of the control. The starting results are in this respect always based on values since the restart of the control. All the data are in contrast not taken into account for the calculation.
[0060] The representation of the results can in this respect take place both in the crane control and on a diagnostic computer to be connected externally.
[0061] The above embodiments in this respect related to the case v D =0, that is the work with a fixed destination. If, in contrast, work should take place with a deck speed other than zero, that is with a further ship as a destination or starting point, the measured values of the third measuring unit MU 3 are used. The mode of operation in this respect substantially corresponds to the case already described above, with the look-up table 23 , however, having a further input. In addition to the speed of the boom tip v C , the deck speed v D is then also used to read out the maximum permitted payload from the table 23 (cf. FIG. 5 ).
[0062] The evaluation of the measured data of the third measuring unit 40 in this respect takes place analogously to the evaluation of the data of the first or second measuring unit 20 . A filtering algorithm 41 is provided for this purpose which determines the deck speed in the vertical direction v D from the data of the measuring unit. In step 42 , the mean value of the upper third is then determined from this. It is then taken into the determination of the maximum payload as the top value of the deck speed.
[0063] The display of the data on the user interface 30 can then take place as already represented above.
[0064] Instead of the speed in the vertical direction v C or v D used in the embodiment, alternatively or additionally, the acceleration in the vertical direction a C or a D can also be used for determining the maximum permitted payload. The evaluation of the measured results can in this respect take place in the same manner as for the speed.
[0065] Evaluation routines analog to those in accordance with FIGS. 4 and 5 are shown in FIGS. 6 and 7 . The horizontal influences are additionally taken into account in step 50 . They can be based on an inclined position of the ship resulting from the load state or from a pre-trim. Dynamic horizontal deflections of the load caused by relative horizontal movements of the installations (ship with crane, ship where the load decreases and increases) are also taken into account here. In this respect, the horizontal influences can be measured or calculated. The values can be taken into account in the payloads by tables or by online calculation
[0066] The present invention makes it possible by the use of measured values of the ship's movement to use a crane employed on a ship despite the movement of the ship produced by the wave movement and thus to use the crane reliably and with high payloads.
[0067] In this respect, any floating body which is thus exposed to a wave movement can be considered a ship in the sense of the present invention. The present invention can therefore also be used with cranes which are arranged on barges or other floating bodies.
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The present invention relates to a crane control for a crane arranged on a ship, having a load moment limitation system which determines a maximum permitted payload, wherein the load moment limitation system is in communication with a measuring unit for measuring the movement of the ship and determines the maximum permitted payload on the basis of data of the measuring unit.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 13/439,105, filed Apr. 4, 2012. The '105 application relates to and claims priority from U.S. Provisional Ser. No. 61/476,965 filed Apr. 19, 2011, and Chinese Utility Model Ser. No. 201120471894.4 filed Nov. 18, 2011, the entire contents of each of which are incorporated herein by reference
FIGURE SELECTED FOR PUBLICATION
[0002]
FIG. 1
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to an ornamental system for securing containers having an open portion. In particular, the invention relates to a system or kit for use with a container or tote container or bag and containing an ornamental/attractant securing unit for securing an open portion thereof and operably enabling a multitude of adaptive attractant features for greater expression of individuality.
[0005] 2. Description of the Related Art
[0006] The term “tote” meaning “to carry” can be traced to the 17th century, but it was riot used to describe bags until early 20th century. Generally, a tote is a container of some kind that is configured to hold diverse day-to-day objects including, but not limited to books, umbrellas, and other recreational gear. The tote bag may also be used as a supporting volume for transporting food items, beverages arid other relatively small items typically piled upon one another in the tote. In other words, the tote bag is an everyday carrier for a variety of rather prosaic objects and items. Such tote bags may be provided as so-called gift bags, colored bags of paper formed for holding gifts or the like.
[0007] It is not uncommon to secure the access to the interior of a tote bag. A myriad of securing mechanisms for tote bags are disclosed in various publications. Perhaps one of the most known configurations has a clip which is not usually a decorative item and makes the entire tote bag look rather dull. Other securing mechanisms may be configured as, for example, magnets. Once again, inasmuch as Applicants are aware, none of magnet-based securing configuration may simultaneously function as a decorative element.
[0008] A need therefore exists for an aesthetically appealing but still functional tote bag configured with a securing mechanism.
[0009] Another need exists for a tote bag with a securing mechanism configured with a decorative component which serves to prevent immediate visual recognition of the securing mechanism.
[0010] A further need exists for a tote bag provided with a replaceable securing mechanism provided with a decorative component.
[0011] Still a further need exists for a kit including a plurality of structurally interchangeable but aesthetically different securing mechanisms for a tote bag.
[0012] Accordingly, there is a need for an improved ornamental securing mechanism for which optionally the parts may also be interchangeably modified to match a user's demand.
ASPECTS AND SUMMARY OF THE INVENTION
[0013] These and other needs are satisfied by a tote bag with a securing, mechanism configured in accordance with the present invention. One of runny salient features of the invention includes the securing mechanism removably mountable to the top lips of the tote bag so as to detachably and releasably seal the lips together. The securing mechanism is configured with a decorative component operative to shield the securing mechanism from being immediately recognized thus providing the tote bag with an attractant aesthetic appeal.
[0014] A securing system for a container includes a securing system and an ornamental system selectively securable thereto for operably enabling a multitude of adaptive attractant features for greater expression of individuality. The securing system includes opposing elements effective to releasably secure opposing open side elements of the container against an unintended opening. The ornamental system includes an attractant feature and may optionally include additional attractant systems for presentation of any one or a combination of a sound, a scent, a visual attractant indicia, a motion, or optionally a secure access function.
[0015] The inventive securing mechanism may be configured as a clip having two arms and a hinge unit resiliently biasing the arms toward one another. Still a further configuration of the securing mechanism includes differently polarized magnets removably or permanently attached to the top lips of the tote bag and securable to the ornamental element. Another configuration of the disclosed securing mechanism may be as simple as liners of Velcro@ removably attachable to the top lips of the disclosed tote bag,
[0016] The inventive system will also be recognized to enable a collectability and a reusability of adaptively either the attractant member on other securing mechanisms, or collective use (attractant and securing mechanism) reusability and collectability. In this way, the system. can be retained between uses, sold as theme kits (e.g., holiday kits, celebration kits, birthday kits etc.) or similarly collected in that way and re-used as a user desires.
[0017] The above and other configurations of the disclosed securing mechanism and system each are provided with a decorative component or components which while providing a reliable element masking the securing mechanism are visually appealing. The other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements,
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention may be better understood by reference to the detailed description of specific embodiments presented herein in combination with the following drawings, in which:
[0019] FIG. 1 is a front side elevational view of one of numerous alternative embodiments of the present invention, shown here on a representative disclosed tote bag.
[0020] FIG. 2 is a close side devotional view of the exemplary configuration of the inventive system according to FIG. 1 .
[0021] FIG. 3 is a rear side devotional view of the seeming mechanism of FIG. 2 without the disclosed tote bag.
[0022] FIG. 4 is a top plan view of the inventive embodiment of FIG. 1 , wherein the securing system operably wad releasably secures sides of the tote bag.
[0023] FIG. 5 is a close side elevational view of FIG. 4 wherein the securing system and the ornamental features are shown in close association with the opening of the tote bag.
[0024] FIG. 6 is a rear elevation of a star shaped decorative item with the rear clip cover removed showing details of a visual and sound attractant system based on the use of a small electronics board usually incorporated into high-end greeting cards.
[0025] FIG. 7 is a rear elevation of a custom circuit board to be mounted to the back of a decorative item on which are mounted all electronic and mechanical components implementing motion and scent attractants.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings which are not to precise scale. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form, here representing exemplary photographed systems or kits, and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, below, or near etc. may be used with respect to the drawings. These and similar directional or distant terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices. It will be further recognized that elements discussed in the context of one alternative embodiment, may be adaptively and alternatively combined with ones of other alternative embodiments without departing from the scope or spirit of the present invention.
[0027] The present invention is an improved tote bag system that incorporates a decorative element or system configured in combination with and operative to mask the presence of a securing mechanism. The inventive tote bag allows for greater versatility, attractiveness, and finishing so that a single bag can serve a multitude of purposes and provide for greater expression of individuality.
[0028] FIG. 1 illustrates the inventive tote bag 10 provided with a securing mechanism which has a decorative or ornamental element or system or feature or means noted at 14 camouflaging the seeming mechanism so that the latter cannot be immediately observed from an outside or distant location and thereby prevents an immediate visual recognition of the securing mechanism.
[0029] In this alternative embodiment, tote bag 10 is configured with a pair of separate opposing flexible material front side sections, with the front side section being denoted at 12 . The side sections are joined together about a perimeter but being separated along at least a portion of a top edge so as to define an opening between top lips 18 , 18 providing the access into the interior of bag 10 . Optionally, inventive tote bag 10 may be configured with a single piece of material folded so as to define the top arid rear side sections with an open top. A variety of non-limited materials can be used for configuring tote bag 10 . For example, the material may include, without any limitation, a fabric, paper, plastic, neoprene, and/or the like. A myriad of configurations of the bag's exterior and interior, respectively, are contemplated within the scope of the invention. A handle 16 (shown here as flexible string or rope) is operably coupled to the respective top lips 18 , 18 can also have a variety of configurations. For example, as illustrated, handle 16 includes two straps each coupled to side section 12 .
[0030] At least front side section 12 of tote bag 10 is configured with an optionally removable decorative or ornamental component 14 . Again, myriad differently configured decorative or ornamental components or elements 14 can be used within the scope of this invention, and those which are further disclosed represent only a small fraction of the alternative embodiments within the scope and spirit of the present invention. Therefore, this disclosure is not limited to the scope of the images. However, decorative component 14 is used here not only for ornamental, aesthetical, or attractant (e.g., advertizing) purposes. It is functionally configured to block or limit the view of a securing mechanism disclosed herein below.
[0031] In particular, decorative component 14 , as illustrated in this exemplary embodiment, has a shape of flower with a stem extending along front side section 12 and may include any material such as a simple felt flower, gemstone cluster with an attached bow, surrounding puff ball, glittery light, projecting gift-card clip, sound generator, scent generator and etc. Portions of the felt flower 14 extend over top lips 18 to cover a securing mechanism 24 , as will be discussed herein below. Optionally, the decorative component 14 may be permanently attached to tote bag 10 , such as glued to front side section 12 . Alternatively, decorative component 14 may be removably coupled to bag 10 . Furthermore, as will be disclosed below, decorative component 14 may be optionally permanently or detachably coupled to securing mechanism 24 . The detachable coupling (not shown) of decorative component 14 may have a variety of operative configurations such as snaps, rivets, spring-clip, adhesive, Velcro ° and the like for removably securing decorative element 14 to securing mechanism 24 . For an additional alternative embodiment, the central region of decorative component 14 may be further enhanced with an additional ornamental attractant element 22 ( FIG. 1 ) adding to the overall appeal of tote bag 10 . The opposite side of element 22 may be formed as a snap removably coupled to front side section 12 of the rote or optionally may be secured to the front face of decorative element 14 . While decorative component 14 is shown to be coupled to the front side section of securing mechanism 24 , the scope of the invention includes a tote bag with two identical or differently configured decorative component coupled to respective fl-out and back side sections, and thus be ornamentally visible from opposing sides of tote 10 .
[0032] FIG. 2 illustrates one of several alternative operable configurations of securing mechanism 24 operative to close the bag opening and thus prevent an easy access into the interior of bag 10 as well as prevent items stored inside from incidentally falling out. As illustrated, seeming mechanism 24 is provided as a simple spring clip or spring member provided with two opposing arms or wings 26 , 26 and a hinge means 19 which is configured to bias for example bottom portions of respective arms 26 , 26 towards one another. The clip itself may be configured as a binder clip, clothes pin, and spring clip. A different concept of the securing mechanism configuration relates to a magnetic securing mechanism. The latter may be configured with a magnetic member and a metal or second magnetic member joined by a flexible line or tab-hinge member, thereby operably functioning as a ‘magnetic clip system. Further alternatively, securing mechanism may be provided with two opposing and non-linked magnetically attractant members (one or both a magnet, and optionally a ferrous material e.g., metal), whereby the decorative element is secured to one of the securing mechanisms and the lips of tote 10 are urged together solely by opposing magnetic coupling urges. Regardless of the design of securing mechanism 24 , aesthetic and even security reasons often require adaptively camouflaging the mechanism.
[0033] In accordance with the invention, decorative component 14 is configured to be at optimally at least ½ greater than, and desirably larger than securing mechanism 24 so as to prevent immediate visual recognition of the latter. In particular, the present exemplary embodiment provides decorative component 14 having a protrusion 30 extending not only above the top lips of bag 10 , but this part also extends over the top ends of the clip. Obviously, the clip is not visible or at least not immediately recognized by someone looking at the front section of bag 10 .
[0034] Referring further to FIGS. 3-5 , alternative views of a similar coupling means (shown as a spring clip 19 in FIG. 2 ) between the securing mechanism and decorative component are contemplated within the scope of the invention. For example, decorative component 14 and securing mechanism 24 may be fixed to one another by a fastening means including, for example, but not limited to glue. Alternatively, the fastening means may be configured as a snap, sliding engagement etc. In accordance with the latter, differently shaped and sized decorative components 14 may be easily used in combination with the same securing mechanism. Alternatively, decorative component 14 may be detachably coupled to securing mechanism 24 .
[0035] Speaking of different configurations, the scope of the invention includes a kit provided with differently shaped and dimensioned decorative components and securing mechanisms. The kit allows the user to select different combinations of the securing and decorative components.
[0036] Returning to the decorative component, in particular FIG. 3 , the configuration of the latter may include any shape and size, provided the design is within the scope and spirit of the present invention. For example, decorative mechanism may include a means for generating light containing a light emitter 30 , a power supply (battery) 32 and a switch 34 or operating mechanism of a kind known to those of skill in the art. The light emitter may have one or a plurality of LEDs. It is contemplated that the light mechanism is energized by a local battery which in turn can be triggered by a switch, by motion sensor 36 etc. It is further contemplated that there may be alternative flashing sequences, or colors, as a form of attraction. An example of a decorative mechanism including a means for generating light containing a light emitter, a power supply (battery) and a switch or operating mechanism is shown in FIG. 6 . Mounted to the back of decorative item 40 are five LED's 50 , a loudspeaker 54 , a lithium coin cell battery power supply 52 , and a commercially available electronics board 42 with processor module 46 , flash memory chip 48 for sound content, and momentary switch 44 with modes to select LED “chasing” display, all LED's flashing rapidly, or playing music or sounds from loudspeaker. In a further modification, the inventive decorative component may adaptively and operatively include a sound and/or a motion generating unit 42 . Again, distantly triggered or locally triggered, the sound and/or motion generating unit 42 may reproduce musical pieces, voices, easily recognizable sounds, or may cause a motion-mechanism (e.g., a dancing-seasonal figure (Santa, Valentine Heart) to move through a repeated sequence. The unit 42 may even be configured to allow the user to record a personal audio message for reply by a second user.
[0037] A second example is shown in FIG. 7 . Here on a custom board 60 are mounted components implementing two further attractants. Two alkaline cells 62 provide power. Switch 64 selects motor driver and timer 66 which operates gear motor 68 for short duration bursts with stationary intervals thereby moving motion attractant 70 back and forth through a crank mechanism (waving motion). Switch 72 selects motor driver/timer/motion detector which operates blower 76 motor. When close motion is detected, blower 76 is operated for a short duration wafting scent from the end of wick 80 which penetrates the cap of scent fluid reservoir 78 . The electronics on-board are similar to that on Pololu Oik 2s9v1 dual motor controller board sold to robotics hobby enthusiasts.
[0038] The inventive decorative component may also alternatively be provided with a combination of pockets differently designed and dimensioned to receive adaptive or supplemental items (in addition to the contents of the tote). The pockets may contain fortunes, sayings, messages, novelty and gift items, candies. Some sort of additional ‘treat’ or ‘teaser’ is also contemplated within the scope of the invention. In addition, the inventive decorative component may include a timer coupled to a recorder informing the user that an appropriate and previously stored time for revealing the gift has come. At that point, user may open a pocket or tote, or optionally the mechanism may even automatically open to allow the user to pull out the gift (e.g., an audio recording of “. . . wait until I get home to open the gift . . . ”).
[0039] Still a further configuration may include a scent-releasable mechanism. Scents may be released in different manners such as by mistering, scratching, or a mechanism containing a solid or gel scent+a warming/releasing mechanism etc. The mechanism may be configured as a flat element, multi-dimensional element, a blower fan may be incorporated etc. within the meaning and scope of the present invention to attract a user.
[0040] The present invention is not restricted to the particular configurations described and illustrated. The described embodiments are not exclusive, and the scope of the invention includes farther different configurations and structures. It is apparent that departures from specific structures and configurations described and shown will suggest themselves to those skilled in the related art and may be used without departing from the spirit and scope of the present invention. Accordingly, the invention should be construed to cohere with all modifications that may fall within the scope of the following brief description of the inventive main features.
Brief Description of Main Features of the Invention
[0041] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism. it will be recognized that the decorative component can be of any attractant type, including, without limitation a textile, printed, film, plush vehicle, or three-dimensional object. For example, as in Fig. I, a combined attractant includes a textile item and a formed three-dimensional jewel object. Alternatively, a small plush character or fuzzy item or rigid three-dimensional sculptural item may be employed. Organic items (e.g., flowers) may also be provided and are within the scope and spirit of the present invention,
[0042] A hand-held bag comprises a body defining an interior and provided an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the scouring mechanism, the securing mechanism comprises a clip selected from the group consisting of a binder clip, clothes pin, spring clip paper, and others,
[0043] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the securing mechanism comprises a magnetic clip including a combination of one magnetic and one metal components or two magnetic components,
[0044] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the securing mechanism comprises a magnetic clip including a combination of one magnetic and one metal components or two magnetic components/
[0045] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the decorative component is either fixed to the body or detachably coupled thereto.
[0046] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the securing mechanism is either fixed to the body or detachably coupled thereto.
[0047] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the decorative component and locking mechanism are either fixed to one another or detachably coupled to one another.
[0048] A hand-held bag comprises a body defining an interior and provides an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the decorative component has a plurality of configurations and is selected from the group comprising one of decorative ornaments made from plastic, fabric or paper, metal, wood and/or or a combination thereof.
[0049] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the decorative component has a plurality of configurations and is selected from the group comprising a sound unit, motion unit, sound generating, light emitting, scent-emitting unit and/or a combination of these.
[0050] A hand-held bag comprises a body defining an interior and provided with an access to the interior, a securing mechanism operative to temporarily restrict or prevent the access to the interior, and a decorative component configured to prevent immediate recognition of the securing mechanism, the decorative component has a plurality of configurations and selected from the group comprising an arrangement of differently shaped and dimensioned pockets, each pocket may comprise a gift, teaser etc.
[0051] A kit for a hand-held bag comprises one or more securing mechanisms each operative to temporarily restrict or prevent the access to an interior of the hand-held bag, and one or a plurality of decorative components, the securing mechanisms and decorative components are configured are selectively coupleable to one another so that the decorative component prevents immediate recognition of the securing mechanism.
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A securing system for a container includes a securing system and an ornamental system selectively securable thereto for operably enabling a multitude of adaptive attractant features for greater expression of individuality. The securing system includes opposing elements effective to releasably secure opposing open side elements of the container against an unintended opening. The ornamental system includes an attractant feature and may optionally include additional attractant systems for presentation of a sound, a scent, a motion, or a secure access function.
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This is a continuation of application Ser. No. 08/158,591, filed Nov. 24, 1993, now U.S. Pat. No. 5,568,639
BACKGROUND OF THE PRESENT INVENTION
1. Field of the Invention
This invention relates to the field of computer file structuring systems.
2. Background Art
Data storage and manipulation is an important function of a computer system. A central processing unit (CPU) of a computer system cannot perform useful services unless data can be presented to it and received from it.
One way in which data can be organized for CPU access, including access for the purposes of finding, writing, reading and erasing part or all of that data, is in the form of a "file." A file is an apparently contiguous sequence of atomic components of data known as bytes.
A byte is the smallest unit of data which can be managed directly by the hardware of a computer. A byte is composed of bits, each of which holds the binary value of 0 or 1. A byte is typically defined as eight bits.
A unit of data within a file may consist of one or more bytes. The significance of the data units in a file depends upon the number of bytes in the unit, the placement of the data unit within the file, the scheme by which the resultant pattern of bits should be interpreted, and the value represented by that interpretation.
File management facilities of a computer system provide the means by which a file can be accessed by application programs as an abstract data stream. These file management facilities include the operating system of the computer, simple file input/output functions typically supplied with computer language assemblers and compilers, persistent storage device drivers and the hardware circuits and embedded control software of computer memory systems.
A file may be considered as a continuous extent of bytes presented by the underlying computer file management facilities. According to this abstraction, the file has an address at which it begins and an unbroken length of component bytes. This is the appearance of files as commonly presented for programmer access by computer file management facilities.
Computer files may be data files or executable files. This distinction is not absolute, because it is possible for a data file to enclose an executable file (in which case it is not immediately available for execution) or to enclose executable routines which can serve as sub-parts of programs. Nevertheless, for present purposes the general distinction can be used to identify data storage as the purpose of the present invention and of the prior art which relates to the present invention.
The organization of data within a file is known as the file format. File formats are not ordinarily managed by the file management facilities of a computer, but rather are defined by programmers and are specific to a given computer program and architecture. There is no universal file format which would make the data created by one computer or one program inherently accessible to any other computer or program. Data written by one program may not be understandable by another and data written on one computer may not be readable on a different computer without reformatting of the data. The need for organization of data within files is a typical problem addressed by programmers. Various approaches have been made to the general problem of data storage and management, but current practice methods of data storage do not provide consistency of file formatting so as to allow the same format to be used for simple, direct file access and for sophisticated data management.
Prior art approaches include: (1) direct file access, (2) formatted data storage with limited data management, and (3) database management systems. In some cases the programmer must design all details of the file format and all procedures of the data management. In other cases data base management systems (DBMS) provide data management but require the programmer to learn the DBMS interface and to obey rules regarding data placement and access.
The direct file access facilities of computers generally provide only the following:
1. Creating and naming new files and renaming existing files, so that files may be accessed by name.
2. Adding one or more bytes of new data to the end of a file.
3. Truncating the length of a file, thereby losing the bytes beyond the new length.
4. Overwriting the values of bytes in an existing file with new values.
5. Copying extents of an existing file, beginning at a position, locatable as an offset from the start of the file, and continuing for a specified length, into another file by means of methods 1, 2, 3 and 4, above, and with the assistance of method 6, below.
6. Erasing existing file names and contents.
The above capabilities can be used in complex ways to alter files to achieve such purposes as overwriting of bytes at an existing position in the file, addition of bytes to the end of the file, and removal of bytes from a file (closing any gap caused by the removal). These actions can effect data storage and management under simple or complex file format schemes and they are in fact used in virtually all instances of data file management.
A programmer can use all of the file management capabilities listed above, but a suitable file format must be designed and data management routines implemented to suit the needs of a particular program. Since many of these needs are repetitive, standard solutions have been developed to address well-defined situations.
Well-known file formats that are suitable for the storage of loosely-structured data for the purpose of data transfer include SDF (system data format), which represents data units as ASCII strings terminated by linefeed characters; ANSI X.12 standard, which defines several layers of data units and sub-units by a system of in-stream specific-value separator bytes and type values which key to externally documented schemas; the telegraphy standard, which uses in-stream control values to describe the rough layout of data units within the stream; and the BASIC language convention of using comma-delimited ASCII data fields, generally in the context of a schema. In this category of file formats, emphasis is upon the containment and identification of data units independent of data management facilities; thus, access to data held in such formats remains a direct file access problem.
The mere separation and identification of data units is not sufficient for circumstances in which the use as well as the character of the data is well known. In such cases there is a need to combine file formats with behaviors specific to the structured data. The prior art attempts to accomplish this in formalized data management schemes.
Structured file access schemes that include limited data management capabilities are often employed to handle data intended for defined uses. Examples are graphic image files, which must be received, displayed and erased, but which rarely need to be indexed, filtered, or summarized. The file formats for graphic images, such as TIFF, PCX, and BMP, are generally acted on by code library procedures from any of numerous suppliers, and some or all of those procedures can be included in a program. Similar observations can be made about digital audio files, instrumentation data files, and any other files that have narrowly defined uses.
Highly structured file formats and sophisticated data management techniques have been developed in prior art. These schemes are categorized as Data Base Management Systems (DBMS). These systems are characterized by large program size and rigid record schemas (field layouts). Such systems do not satisfy the needs of programs that require irregular data file structures and simple file access. More advanced systems, categorized as Object-Oriented Data Base Management Systems (OODBMS) are even larger in size and generally slower in execution, but many of them allow data to be stored as objects with definable behaviors.
A data management facility is available under the commercial name KALA that occupies a conceptual space between the low level of direct file access and the high level of database schemes. KALA appears to be an object-oriented persistent file store facility that leaves much of the data organization to the programs that employ the product.
SUMMARY OF THE INVENTION
The present invention provides an object-oriented file structuring system for use on computers. The structured arrangement of information within a computer file is known as a file format. A computer file might exist only in computer memory, but its most common embodiment is in persistent storage on magnetic recording disks and tapes or on optical recording disks.
Objects in the present invention are encapsulations which associate data values with data type and identity with certain behaviors, and possibly with other information. A computer program designed to recognize an object can obtain from it at least one behavior (i.e., service), such as output of the enclosed data. It is the association of identity and behaviors with data that provides the basis for the term `object-oriented`.
The present invention defines a file format that uses encapsulation and combines it with functionality necessary for the creation, use, modification and removal of different types of objects known as CONTAINER and DATA objects. The invention provides data management facilities for unstructured data, and it offers a suitable substrate for the development of object-oriented databases.
The invention permits object access by multiple threads of execution and object-by-object access control, and it includes file management capabilities such as file error detection and recovery, transactions, and journalling. The invention also allows any object to be annotated with a name and with comments.
The invention may be employed in several embodiments including, but not limited to, (1) a statically linkable code library, (2) a dynamically linkable code library, (3) a message-handling process, and (4) a device driver for storage media.
Notation and nomenclature are defined for building files, CONTAINER objects, and DATA objects, for defining relationships between and among files and objects and for addressing and describing objects.
A named and continuous sequence of information accessible to a computer, including a sequence of objects, is called a file. A computer file which is created and managed by the invention is called a MFILE. A MFILE consists of a HEAD, which is a CONTAINER object; it may have a TAIL which is a series of one or more objects of any type; and all of the file contents are constructed as objects that are demarked by consistently defined PREFIX and SUFFIX structures.
Computer programs that employ the invention place data values into DATA objects. A DATA object defined by the invention is a typed encapsulation of one or more typed values together with supporting information. The source of the values is defined by the programmer; it may be internal program data or external data gathered by the program as specified by the programmer.
The invention also provides for the creation of CONTAINER objects into which the program may place other CONTAINER objects and/or DATA objects. A CONTAINER object is a typed encapsulation of other CONTAINER objects and DATA objects, together with supporting information. A programmer who uses the invention determines which DATA objects and CONTAINER objects shall be placed within a given CONTAINER object. A CONTAINER object may enclose no objects, or it may enclose DATA objects, CONTAINER objects, or both.
There is also in the invention a SYSTEM object, which is not directly accessible to programmers. A SYSTEM object is an encapsulation of control information necessary to support internal file structuring and object management, and in the invention a SYSTEM object appears only in the tail of an MFILE or JOURNAL. The creation, maintenance and destruction of SYSTEM objects is automatically managed by the invention. In the present design SYSTEM objects do not exist within a CONTAINER, but there may be reason to allow this in a future improvement.
The PREFIX and SUFFIX structures of an object encode the object category (CONTAINER, SYSTEM, or DATA), the size of the object, and additional information appropriate to the category. Any object of each of the types identified in this paragraph, and all of their subtypes, can be type-identified from the PREFIX or SUFFIX structure of the object. The invention includes a facility for defining further sub-types of SYSTEM, CONTAINER and DATA categories.
Any object can be flagged in its brackets as holding Extended Information, which the present invention defines as a set of optional information such as that which pertains to identity, compression, encryption and presence of a checksum. The invention includes a facility for defining further categories of Extended Information items.
The PREFIX and SUFFIX structures are identical in content and similar in layout. For convenience, the term BRACKETS is used to refer to them as a pair. In one limited instance, the PREFIX and SUFFIX are merged into a single-byte TOKEN which represents an ABSENT DATA object.
The invention provides a facility called a `HANDLE` which may be declared to exist in a program as the means for a program to access a given MFILE. The HANDLE always addresses an object. Upon creation, the HANDLE addresses a portion of the MFILE called the HEAD which is a CONTAINER object. From this position the HANDLE may NAVIGATE to CONTAINER and DATA objects contained within the HEAD or TAIL of the MFILE through use Of procedures which are called through the HANDLE.
An object which the HANDLE addresses at a given moment is said to be in FOCUS. Multiple HANDLEs may exist on a given MFILE at the same time, and they may have the same object or different current objects in FOCUS.
In computer memory the invention maintains a data structure called a FOCUS ENTRY, each instance of which references one object within an MFILE; any number of HANDLEs may then reference that FOCUS ENTRY as the means of having the referenced object in FOCUS. The FOCUS ENTRY stores a value known as a MAGIC STRING, which represents the current logical position of the object within the MFILE.
A FOCUS ENTRY is needed to support the current FOCUS of a HANDLE, to keep track of CONTAINER objects that enclose the current FOCUS of any HANDLE, to keep track of recent alterations to the MFILE, and for other purposes. Any HANDLE may reference a FOCUS ENTRY.
The invention maintains a list of all FOCUS ENTRIES needed at any given moment; this is called a FOCUS LIST. The FOCUS LIST is maintained in a sorted order, based on the MAGIC STRING values of FOCUS ENTRIES, and thereby it embodies the logical structure of the MFILE.
The FOCUS LIST is likely to have FOCUS ENTRIES representing objects in the HEAD and in the TAIL of the MFILE; as a HANDLE NAVIGATES among logically adjacent objects, it may successively reference objects which are physically separated and lie in the HEAD or in the TAIL in a physical order that differs from their logical order.
As described above, an MFILE is composed of two parts, denoted the HEAD and the TAIL. The HEAD is a CONTAINER object in which the physical location of objects is consistent with their relative logical order. The TAIL only exists at times when alterations have been made to the MFILE. The TAIL is comprised of SYSTEM objects and other objects which, taken together with the contents of the HEAD, represent the content and logical order of the MFILE. All MFILE alterations are made in the same time sequence as objects appended to the TAIL.
Periodically, the CONTAINER and DATA objects in the TAIL of a file are merged in logical order into the HEAD of the file, so that the HEAD comprises the entire MFILE. This process is called RECONSTITUTION. The deleted TAIL becomes part of a JOURNAL that minors all changes to the MFILE, unless the programmer elects not to maintain a JOURNAL on that MFILE. The JOURNAL can be used for roll-forward RECOVERY and roll-backward UNDO of file changes. The SYSTEM objects that were in the TAIL and which store information about logical file structure are saved in the JOURNAL but are not copied to the HEAD by RECONSTITUTION.
In the balance of this SUMMARY OF THE INVENTION, attention is turned to the BRACKETS (PREFIX/SUFFIX pair), the Object Control System and Data Management Support.
3. Brackets
Each object consists of a PREFIX BRACKET followed by object contents followed by a SUFFIX BRACKET. The PREFIX and SUFFIX encode their own sizes, the size of the object and object type information. Each BRACKET also has a parity bit, a flag to indicate whether the object serves testing purposes, and a flag to indicate whether Extended Information is present. Extended Information is a set of optional items including a checksum, a sequential number identifier, references to encryption and compression methods, a name, and other information that can characterize the contents.
To provide platform independence, all object BRACKETs are encoded as byte streams. Byte stream encoding is accomplished by having each PREFIX begin with a KEYBYTE and each SUFFIX end with an identical KEYBYTE. Because all computer systems can read one byte at a time, the KEYBYTE ensures that information about the byte stream can be obtained by the operating system of any platform.
The BRACKETs of an object are identical in size, and that size is encoded in identical KEYBYTEs that appear as the first and last bytes of the object. Each BRACKET encodes the offset at which the KEYBYTE of an adjacent object might be found: this offset is found in the PREFIX for `next` objects and in the SUFFIX for `prior` objects. The absolute values of these offsets are identical. Using this scheme, objects of varying size can be included in the file without reserving the space that would be required for fixed-length objects and without overloading the range of directly representable values in order to use a delimiting symbol.
Because the BRACKETs of an object encode the entire length of the object, a CONTAINER object holds the information necessary to bypass all of its contents, regardless of the direction of movement. This is important because CONTAINER objects can include multiple nested CONTAINED objects and multiple DATA objects, all of which can be bypassed in one movement. If there is any content within a CONTAINER, it begins immediately after the PREFIX of the CONTAINER; likewise, unless the CONTAINER is empty, some object ends immediately before the SUFFIX of the CONTAINER. If Extended Information is present, it is placed between the object PREFIX and any other contents.
Each BRACKET contains the object type, which is a specific binary numeric value that uniquely identifies that type. In the preferred embodiment, this information is present in a dedicated group of 6 bits in a byte known as the TYPE BYTE. In the preferred embodiment of a TOKEN, which is a DATA object by definition, five bits are used.
Because the purpose of an MFILE is to enclose data which comes in numerous shapes and sizes, the DATA object defined in the invention is available in commonly-used subtypes, such as INTEGER and STRING, each of which is uniquely identifiable by the numeric type value in the TYPE byte of the BRACKETS. The invention allows the future development of additional object types through use of numeric values in the TYPE byte which are not defined in this invention.
Within a DATA object the value encoding uses memory-based data storage sizes with data represented in the same format on all computers. For numeric values, this representation is canonical Most Significant Byte First (MSB) order, which provides platform independence with slight performance penalty on computers which do not use this byte order. For character and string values, the data is stored in 1, 2, or 4 bytes per character, depending upon the symbol mapping system in use. An index to the symbol mapping can be preserved in the DATA object itself or in any enclosing CONTAINER object. Other defined DATA types use similar value representations.
Any DATA object can be marked absent. Any absent DATA object can be represented either by a DATA object that has no enclosed storage space for a value or by a single-byte TOKEN that preserves the DATA typing information of the object.
The Object Control System
The invention controls access to an MFILE through the use of a HANDLE, which is a memory structure that references one object at a time. An arbitrary number of HANDLEs can be declared to exist in a program, each of which is open upon an MFILE and any number of which may be open on the same MFILE. At creation of a HANDLE, its focus is on the HEAD of an MFILE, which is itself a CONTAINER object.
In concept, a HANDLE navigates from object-to-object in an MFILE by jumping forward the distance encoded in the PREFIX of the current object for forward traversing or jumping backward the distance encoded in the SUFFIX of a current object for backward traversing. This concept holds true only for the ideal MFILE that has only a HEAD, because in that state all objects have the same physical and logical order. Because it is necessary for HANDLEs to be able to navigate at all times, however, the invention relies on indirect navigation by causing the HANDLE to reference FOCUS ENTRIES in the sorted order in which they appear in the FOCUS LIST. The invention creates from the physical file object a new FOCUS ENTRY whenever one is needed that is not present as part of the FOCUS LIST in memory. Programmers thus work with logical files and can freely create and modify the logical relationships of objects within the MFILE.
It is not necessary for the invention to create a FOCUS ENTRY for each object in the file, because a FOCUS ENTRY can be generated from a file object when needed. A FOCUS ENTRY does need to exist to support the current FOCUS of every HANDLE, and there are other needs as well, such as the need to reference objects recently removed from the file or recently added to the file.
The present invention causes each file to be altered only by additions to the tail of the file, so that the physical location of previously-added DATA is stable and thus easily accessible in a multi-threaded environment. Information is retained in the FOCUS LIST and in the TAIL of the MFILE to map the location of removed objects which have not yet been remove physically from the MFILE and to map the logical positioning of all objects added to the TAIL of the MFILE which are not yet in physical positions which match their logical positions. Placement of alterations at the end of the MFILE facilitates multi-thread multi-handle file access and allows multiple threads of execution to access, read, and modify various parts of a single file at the same time.
The FOCUS LIST tracks objects which are of interest to any open MFILE HANDLE and provides information about potential conflicts between HANDLEs. If two HANDLEs attempt to access the same object at the same time and conflict with each other, the system can continue without locking all other access to the rest of the MFILE; all other HANDLEs can continue modifying the file while the system deals with the individual conflict between the particular two conflicting HANDLEs.
The CURRENT FOCUS of a HANDLE is the point of reference for all information that can be obtained from an object and for all file ALTERATIONs, including TRANSACTIONs. While a HANDLE has an object in FOCUS, all information and values pertaining to the object can be obtained through the HANDLE without direct management of the MFILE by the programmer (although it is of course managed internally by the invention). Queries are available for object type, data value type, data element size and other descriptive information associated with the object, known as Extended Information items.
A DATA object within a CONTAINER is not accessible when a HANDLE has the CONTAINER in FOCUS; the HANDLE must first move its FOCUS into the CONTAINER and then move to the contained object. HANDLEs are the means of programmer access to the invention; they do not access SYSTEM objects which are created and used internally by the invention.
Alterations to an MFILE are made in reference to an object that is in CURRENT FOCUS. The available alterations are REMOVE, INSERT, REPLACE and APPEND. Any alteration other than REMOVE can take place as a FIXED TRANSACTION, and any alteration can take place within a WANDERING TRANSACTION. A TRANSACTION is a conditional series of alterations that must be resolved by COMMIT or ABANDON, and no part of a COMMITTED TRANSACTION will affect the file unless all parts of it affect the file.
Once the placement of an alteration has been established by the CURRENT FOCUS and the selected alteration, the action required to add an object in an alteration depends upon the alteration selected and type of object that is to be generated. The full sequence of actions to add a DATA object is ALTER, WRITE, COMMIT; the full sequence required to add a CONTAINER to the MFILE is ALTER, CREATE CONTAINER, COMMIT (in this example the added container will be empty). In these sequences the word ALTER stands for one of INSERT, REPLACE and APPEND. The general concept is that the placement of the alteration is announced in advance with reference to the current FOCUS. The concepts expressed by the action phrases given above may be embodied in differing function names without changing the invention.
Once generated an object has a TYPE defined at its generation, and thereafter it can be managed only as defined in the invention for objects of that TYPE. Thus, for example, data written as an INTEGER DATA object can only be read as an integer, and any attempt to read it as another DATA type will fail and any attempt to move into it (which a CONTAINER allows) will fail. Likewise, any attempt to read the value of a CONTAINER will fail, but movement into the CONTAINER will succeed.
While an object is in FOCUS, its value, type, and other supporting information can be obtained by invoking functions defined in the invention. The value of a DATA object is obtained by calling the READ function appropriate for that DATA type. All TYPE and Extended Information is obtained by QUERY functions.
An alteration is placed in reference to the current FOCUS of the HANDLE that performs the alteration. REMOVE always affects the object in current FOCUS, as does REPLACE. INSERT places the new object in the position prior to the current object, and APPEND places the new object in the position after the current object.
Alterations are accomplished by collecting the added or changed data in a buffer and then adding that buffer, together with information necessary to create the appropriate SYSTEM object, to an UPDATES QUEUE when a COMMIT occurs. Similarly, the REMOVE action causes only the information necessary to create the appropriate SYSTEM object to be added to the UPDATES QUEUE. The purpose of the SYSTEM object is to carry essential information regarding the kind of alteration and the logical placement of that alteration in the MFILE.
Once objects have been removed from the MFILE or added to the MFILE, its physical configuration no longer conforms to its logical configuration. For example, a new object on the TAIL will be logically placed within a CONTAINER inside the HEAD. Similarly, added objects may appear in the TAIL in an order that is dissimilar to their intended logical order. SYSTEM objects associated with DATA and CONTAINER objects in the TAIL retain the needed logical references, but they are duplicative of information maintained in the FOCUS LIST and are only used if needed to reconstruct the FOCUS LIST in case of an unexpected computer process interruption.
Periodically, a RECONSTITUTION algorithm is executed (without user intervention) to update the physical file so that it will correspond to the logical file. The RECONSTITUTION algorithm briefly halts alterations to the file to create a copy of the FOCUS LIST for updating. A reconstituted version of the file is created (on an optional separate thread of execution) in which the physical and logical arrangement of objects is consistent. This reconstituted file replaces the original, unreconstituted file. If the RECONSTITUTION process takes place on a separate thread of execution, alterations can continue to occur to the original file. At the last step of RECONSTITUTION, these alterations are added to the tail of the reconstituted file. In such a case, file access is not compromised during the RECONSTITUTION process.
Data Management Support
The invention provides TRANSACTION controls to assure that a defined set of MFILE alterations will be atomic, which means that an alteration made as part of a TRANSACTION will not affect the file unless all alterations which are part of the same transaction reach the file. Two variants of this concept are presented by the invention: FIXED TRANSACTIONs allow multiple alterations that can be added to the file at a single location; and WANDERING TRANSACTIONs allow multiple alterations at multiple locations within the file.
The invention also provides means of identifying and isolating corrupted areas of an MFILE. Because the length of each object is encoded in its PREFIX and SUFFIX, physical corruption which alters the actual or indicated length of file objects is easily detected. Furthermore, each PREFIX and SUFFIX contains a parity bit which is used to assist the detection of corruption of one or both of the BRACKETS. In addition, an optional checksum may be recorded with any object to validate its contents.
The present invention will automatically detect a corrupt area in an MFILE whenever an attempt is made to navigate to or into a corrupted object. The invention maps the range of the corruption, marks it as a BAD OBJECT, and copies it to an errorfile. The BAD OBJECT can be reached by a HANDLE performing a navigation move, but it can only be replaced or removed. The error file may contain recoverable objects which can be identified by matching PREFIX and SUFFIX structures. It is possible to develop sophisticated data recovery utilities based on this object design.
At the programmer's option, a JOURNAL is provided to match every MFILE, from which the MFILE can be reconstructed and from which alterations can be reversed in a series of `undo` steps. The structure of the JOURNAL is basically that of the MFILE with only a TAIL or with a TAIL that is never merged into the HEAD by RECONSTITUTION; the structure depends upon the user's choice of styles for retention of file backups.
The JOURNAL can be used together with a base file (a copy of an earlier version of the MFILE) to reconstruct the MFILE in case of a computer malfunction. Similarly, the TAIL of an MFILE is used to reconstitute an MFILE in the event of a computer malfunction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example of a computer system.
FIG. 2 illustrates a TYPE byte of the present invention.
FIG. 3A illustrates an object of the present invention.
FIG. 3B illustrates the body of an object of the present invention.
FIGS. 4A and 4B illustrate detailed views of a PREFIX and a SUFFIX, respectively.
FIG. 4C illustrates the content of a DATA object.
FIG. 4D illustrates the content of a CONTAINER object.
FIGS. 5A-5C illustrate the creation of a logical file structure.
FIGS. 6A and 6B illustrate a flow diagram illustrating the RECONSTITUTION process.
FIG. 7 is a flow diagram illustrating step 602 of FIG. 6A.
FIG. 8 is a flow diagram illustrating step 606 of FIG. 6A.
FIGS. 9A and 9B are a flow diagram illustrating step 609 of FIG. 6B.
FIGS. 10A-10C illustrate the state of the physical file stored in memory during the creation and manipulation of the logical file of FIGS. 5A-5C.
FIG. 11 illustrates a focus list of the present invention.
FIG. 12 illustrates a file formatted in accord with the present invention.
FIG. 13 illustrates the format of the entries in the focus list.
FIGS. 14A through 14G illustrate the layout of the Extended Information structure.
FIG. 15A illustrates the content of a SYSTEM object.
FIG. 15B illustrates the commands of a SYSTEM object.
FIG. 16A illustrates the encoding of a MAGIC STRING for two levels.
FIG. 16B illustrates the encoding of a level in the MAGIC STRING.
FIG. 16C illustrates the MAGIC STRING of FIG. 16B after the encoded information has been decoded into a 32 bit variable.
FIG. 17A illustrates a file composed of objects.
FIG. 17B illustrates two HANDLES having FOCUS on objects in the FIG. 17A file.
DETAILED DESCRIPTION OF THE INVENTION
A method and apparatus for providing an object oriented file structuring system is described. In the following description, numerous specific details, such as operating system, PREFIX and SUFFIX sizes, etc., are set forth in detail in order to provide a more thorough description of the invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well known features have not been described in detail so as not to obscure the present invention.
A. Concepts of File and Object.
The present invention provides a method and apparatus for access to the contents of files at logical positions, rather than physical positions.
A computer file is a continuous and uninterrupted sequence of bytes identified by a starting position that has an extent (a continuous length), generally all of which is accessible to the computer. In most implementations, the file is also identifiable by a name. A byte is a unit of data which can be manipulated atomically (all at once) by the central processing unit (cpu) of a computer. In most computers, a byte consists of eight bits of binary information. Each bit holds a value of 0 or 1. The content of a file may consist of instructions to the cpu, or data, or an admixture of instructions and data.
In the present invention, files are considered as embodiments of data that may include executable programs and executable routines as components of the file. Computer files are generally stored on persistent media, such as magnetic disks, but they must be copied into computer memory to become directly accessible to the cpu; this copying is ordinarily performed by facilities provided by computer operating systems.
The organization of components of a file is generally known as a file structure. There are no requirements for the structuring of files other than the requirements set by a programmer or by a standard which the programmer wishes to follow. There are numerous file structure standards in common use. The present invention differs from known file structures.
Computer files defined by the present invention are characterized by a consistent paradigm: each file consists of a HEAD part followed by a TAIL part, and the TAIL part is a temporary appendage that is merged periodically into the HEAD. Files defined by the invention contain objects that are also defined by the invention, and data held in the file is located within specific objects. The HEAD of the file is an object, and the TAIL consists of one or more objects when it exists. A computer file of the structure and content defined by the present invention is referred to as an MFILE.
An object appears to a computer as a structure of information accessible in memory that possesses type and is associated by type with defined behaviors which are implemented by the computer. Thus, information cannot exist as an object without association of its type with one or more computer-executable routines which may use the information (besides type) held in the object; this association is provided by an executable program which is designed to recognize the structure and type of the object and to access the information held within an instance of that structure. An object also has identity, which may be simply its unique position within the file or may be a unique numeric identifier assigned at its creation.
A computer program may be uniquely designed to manage objects, or it may incorporate within itself access to pre-defined executable code or executable processes that manage objects. The present invention provides a pre-defined facility that can be used by or incorporated into other computer programs to provide object management, including those behaviors which have been defined in the invention for each type of object.
Objects defined by the invention have a precisely-defined structure that is characterized by BRACKETing of the beginning and the end of the object. The BRACKETs are self-defining structures that encapsulate type, contents and other information. The objects of the present invention fall into three general categories: DATA objects, CONTAINER objects, and SYSTEM objects, each of which is delimited by BRACKETs consisting of a PREFIX and a SUFFIX. A DATA object holds zero or more typed values; a CONTAINER object encloses zero or more DATA objects and zero or more other CONTAINER objects. SYSTEM objects hold control information necessary to keep track of the logical organization of the file and of modifications to the file.
B. Symbolic Notation.
The BRACKETs that encapsulate objects of the invention appear as the following symbols in the preferred embodiment of documentation of the invention:
{ CONTAINER object PREFIX
} CONTAINER object SUFFIX
[ DATA object PREFIX
] DATA object SUFFIX
< SYSTEM object PREFIX
> SYSTEM object SUFFIX
The BRACKETs {}, [] and <> are referred to jointly as BRACKETS in the present invention. There is no significance in this notation to the spacing between a PREFIX symbol and a SUFFIX symbol of an object, or between the SUFFIX symbol for one object and the PREFIX symbol for another object, or between the PREFIX symbol of a CONTAINER and the PREFIX symbol for a contained object. For example, {}[] and { } [ ] mean the same thing.
The smallest file that can be represented in the preferred embodiment of present invention is designated as { }. This is a CONTAINER object that holds no objects within it. Any CONTAINER object can hold any number of CONTAINER objects and any number of DATA objects, including none at all. Consider for example, the following example:
{{}[][]}
The above is a symbolic representation of a file. The outermost BRACKETs "{ }" are themselves the extremes of a CONTAINER that contains one empty CONTAINER (first enclosed pair of BRACKETs "{ }") and two DATA objects (the second and third enclosed pairs of BRACKETs "[ ]").
In the preferred embodiment, the symbolic notation is expressed in "levels" to represent nesting of CONTAINERs, one inside another. However, the levels are not required. The following is the same example, showing a CONTAINER object and two DATA objects nested inside another CONTAINER: ##STR1##
The number and levels of objects of the preceding example can be expanded by adding objects to the empty CONTAINER object. First, we rewrite the above example with reference numbers for the CONTAINERs and DATA objects (note that the numbers inside the brackets represent the logical positions of the objects, not any information actually stored within): ##STR2##
Next add a DATA object 0.1.1 and a CONTAINER object 0.1.2 to CONTAINER object 0.1. Also add one CONTAINER object 0.1.2.1 to CONTAINER object 0.1.2 as follows: ##STR3##
Note that the highest level object is the HEAD of the MFILE itself, which always exists. Because this level always exists, it can be implied, so representing it is optional.
The foregoing examples represent the logical structures of files. Due to characteristics of the invention that are explained later, the alteration of a file results in a temporary physical state that differs from the logical state, because all added objects and all information about alterations of MFILE logical structure are appended to the TAIL of the MFILE. The temporary physical state for the preceding example may be represented symbolically as follows (assuming that all of the added objects became part of the MFILE before the temporary state ended): ##STR4##
Note that in this representation each added object is preceded by a SYSTEM object that provides logical placement information. The SYSTEM objects are no longer needed after the objects that were temporarily added to the end of the MFILE have been placed in physical positions that accord with their logical positions.
C. File Structure.
An MFILE consists of objects, arranged in structural components of the file called the HEAD and the TAIL. The HEAD of the file is a CONTAINER object, and the TAIL of a file is a sequence of objects of SYSTEM, CONTAINER and DATA types.
Within the HEAD objects have physical locations that are consistent with their relative logical locations. Thus, contained objects are located between the PREFIX and SUFFIX of their container, and adjacent objects are described as PRIOR to or NEXT to one another. An exception exists for a removed object, which temporarily exists in the HEAD but which is the subject of a SYSTEM object in the TAIL that represents the adjustment of logical positions that results from the removal. Another exception exists for added objects, which temporarily are placed in the TAIL but which hold logical positions within the HEAD.
The TAIL exists for the purpose of allowing all file alterations to be appended to the end of the file in the sequence in which the alterations occur, regardless of the logical position that the object is intended to assume. A SYSTEM object exists to retain information about the alteration and the logical positions affected by the alteration. If the alteration consists of removal of an object, the alteration is represented on the TAIL by a SYSTEM object only. If the alteration is additive, which includes replacement of an object, the SYSTEM object is followed on the TAIL by all objects that were added to the MFILE in the same alteration.
D. Object Structure.
The general structure of an object is illustrated in FIG. 3A: each object consists of a PREFIX 301 followed by a BODY 302 followed by a SUFFIX 303. The internal structure of the BODY is illustrated in FIG. 3B. Adjacent to the PREFIX 301 there is an optional Extended Information structure 304, followed by the object CONTENT 305 and the SUFFIX 303. In the case of a DATA object, zero or more typed values occupy the CONTENT 305. In the case of a CONTAINER object, zero or more objects occupy the CONTENT 305. For a SYSTEM object (referring now to FIG. 15A), the PREFIX 301 is followed by a COMMAND 1502, a VIRTUAL FILE POSITION 1503, a REFERENCE OBJECT MAGIC STRING 1504, and the SUFFIX 303.
FIGS. 4A and 4B illustrate the general internal structure of BRACKETS. FIG. 4A shows a PREFIX which begins with a KEYBYTE 401P, followed by the PREFIX REMAINDER 402P and the object BODY 302. FIG. 4B shows a SUFFIX which begins with the object BODY 302, followed by the SUFFIX REMAINDER 402S and the KEYBYTE 401S. The functionality of these components and the bit patterns used in their preferred embodiment are discussed below.
E. Container Objects.
The purpose of CONTAINER objects is to enclose zero or more other objects of any type. CONTAINER objects may enclose other objects of any kind, except that in the current implementation of the invention SYSTEM objects never appear within a CONTAINER. The CONTAINER object type is shown in FIG. 2 as defined in the TYPE byte of BRACKETS in the preferred implementation. The general layout of the contents of a CONTAINER object is illustrated in FIG. 4D, in which any number of contained objects 405 and 407 constitute the CONTENT 305 of the CONTAINER object. Note that it is permissible for a CONTAINER object to be empty, in which case the CONTENT 305 will be missing but all other parts of the object will be present.
Files of the preferred embodiment include a top level CONTAINER. The SUFFIX of the top level CONTAINER marks the end boundary of a reconstituted file. Any part of the file that has been reconstituted is necessarily within the top level CONTAINER, known as the HEAD. Therefore, the location of the beginning of the TAIL of a file is easy to determine.
F. Data Objects.
DATA objects hold zero or more data values, as defined by their respective sub-TYPES. If no data value is present, the object is marked ABSENT but all other components of the object exist in the file. The DATA object type is shown in FIG. 2 as defined in the TYPE byte of BRACKETS in the preferred implementation. FIG. 4C illustrates the presence of a DATA VALUE 403 (which may be multiple, such as an array or structure) as the DATA object CONTENT 305.
Certain DATA objects can contain defined supplementary typing information. CHAR and STRING can store foreign-language symbols, such as Chinese ideograms, coded according to the Extended ASCII or Unicode standards. In the preferred embodiment, an index to the symbol map in use is stored in the MAP element of the Extended Information Structure, with ASCII standard mapping assumed in the absence of a MAP value. Any CONTAINER may contain the same symbol map information, in which case the symbol map for all contained CHAR and STRING objects is defined by the CONTAINER unless an intermediate container or the CHAR or STRING object itself overrides that default definition. The MAP element is discussed below.
In the preferred embodiment, a DATA object holds one data value or data set per object. In alternate embodiments, multiple data values and/or data sets may be held. Instances of data sets are arrays, structures of typed elements, sequences, unions, and fundamental data structures of any type. The present invention defines single-value elementary TYPEs, such as INTEGER and STRING, but the invention comprehends the extension of the typing system to complex data types. The defining characteristic of object types is that the TYPE is embedded in the object when the object is created and that the TYPE can be ascertained by implementations of the invention that will always associate the same defined behaviors with that TYPE.
For those types that are often discriminated by storage size, such as short and long integer, the distinction is preserved by virtue of the fact that the data storage representation occupies the same number of bytes as it did on the computer where it was first generated.
The INTEGER type can contain a signed integer value that is limited in range only by the storage defined for it on the computer platform where it was first generated. If the storage required for the value is too large for a different platform, an error is generated when an attempt is made to read it.
Similarly, the UNSIGNED INTEGER type can contain an unsigned integer value that is limited in range only by the storage defined for it on the computer platform where it was first generated. If the storage required for the value is too large for a different platform, an error is generated when an attempt is made to read it, and the value remains unaccessible.
The FLOAT type can contain a floating point value that is limited in range only by the storage defined for it on the computer platform where it was first generated. It can hold float, double and long double values in the format defined by IEEE Standard 754-1985, promulgated by The Institute of Electrical and Electronics Engineers. If the storage required is too large for a different platform, an error is generated when an attempt is made to read it.
In the preferred embodiment, the representation or INTEGER, UNSIGNED INTEGER, and FLOAT is in canonical MSB (Most Significant Byte) two's complement binary format.
The CHAR type can hold 1, 2, or 4 byte storage that represents a single symbol in a defined symbol set. The default symbol set used in the preferred embodiment of the invention is Extended ASCII, but any symbol map of the UNICODE standard can be indicated in the MAP element of the Extended Information structure of the CHAR object or of any CONTAINER holding the CHAR object, in which case the identified symbol map is identified for use by the calling code. When a CHAR object is read the value is retrieved into a byte array variable in computer memory, where the byte array is of the appropriate storage size.
The STRING type can hold any length string that can be BRACKETed within an object. The string is represented as an array of 1,2, or 4 byte values that equate to a symbol set. The default symbol set used in the preferred embodiment of the invention is Extended ASCII, but any symbol map of the UNICODE standard can be indicated in the MAP element of the Extended Information structure of the STRING object or of any CONTAINER holding the STRING object, in which case the identified symbol map is identified for use by the calling code. When a STRING object is read, the value is retrieved into an array of variables of the size used to store the character components of the STRING object.
The BOOLEAN type holds TRUE or FALSE as a value, which is represented as a non-zero integer for TRUE and as zero for FALSE. Any signed integer may be written to BOOLEAN, but the value retrieved into an integer variable by reading the object will be zero or one.
The BINARY type is used to enclose data that is anonymous to the typing system of the invention. The invention does not alter the presentation of this data value, even when the platform of origin differs from the platform on which the data is to be read. The value is retrieved into a buffer of the required length, which can be obtained from the BINARY object by QUERY.
The ENUMERATION type is used to store signed integer values of a defined set. The representation is the same as INTEGER, but the difference of TYPE identifies the value as one which may have storage characteristics that differ from that of INTEGER on various machines.
G. Non-Value Data Objects.
There are mutually-exclusive cases of DATA objects that have no values, per se. In the present invention, five of these cases are specifically encapsulated in objects. The `absent` special case is represented by a TOKEN or a DATA object with no space for storage. The other special cases are defined as a dependency of TYPE and are represented in the TYPE MAP element of Extended Information within an object. The following special cases have been defined (others are possible):
______________________________________absent DATA for all TYPEspositive infinity for numeric TYPEsnegative infinity for numeric TYPEs except UINTnot a number for numeric TYPEsnull for STRING, BITSTREAM, FILE______________________________________
The "absent DATA" case is especially useful where data is stored in a defined structure holding defined fields and where data is collected from an input stream. Many data storage implementations make no distinction between a numeric value of zero and an uninitiated numeric field, or between an empty string field and a string field that has not been initiated. This condition makes it difficult to identify incomplete or missing objects. The present invention, by contrast, can denote any typed object as ABSENT, thereby denoting that it was not initialized with a value when an object of that TYPE bearing a value was expected. ABSENT is indicated without limiting or overloading the representable DATA value range, and it preserves the DATA TYPE of the missing data.
The "infinity" special cases represent instances in which a numeric type is needed, but no numeric value would properly represent "infinity."
The "not a number" case (which mathematicians denote as NaN) exists when a numeric value is expected but the submitted value does not make sense: examples are infinity divided by infinity or zero divided by zero.
The "null" special case represents an empty string. In a "C" or "C++" language binding, a zero CHAR could represent an empty string, and this is in fact allowable in the invention. Other languages, however, manage string definition differently (PASCAL, for example, prefaces a string with a length indicator). The "null" special case provides a common standard that allows consistent storage of strings, regardless of the computer language in use. NULL is indicated without limiting or overloading the representable DATA value range.
H. System Objects.
SYSTEM objects provide the means by which the present invention stores the information that is essential to allow correct reconstruction of an MFILE in the event of unexpected interruption of a computer program which employs the invention. The SYSTEM object stores much the same information that is retained in a FOCUS ENTRY, described later. The FOCUS ENTRY resides in computer memory and is used as the information source for periodic reorganization of the MFILE so that the physical object structure of the MFILE embodies its logical object structure. In the event of program interruption, however, the FOCUS ENTRY is lost; in this case the SYSTEM objects in the TAIL are used to rebuild needed FOCUS ENTRIES so that the MFILE can be appropriately reconstructed.
The SYSTEM object appears in the TAIL of an MFILE, where it precedes each object added to the MFILE. The SYSTEM object stands alone in the instance where it is used to indicate the removal of an object from the MFILE, and it stands in conjunction with one or more added objects where it is used to indicate the presence of an additive alteration to the MFILE. The SYSTEM object is eliminated by the process, known as RECONSTITUTION, which restructures the MFILE so that the physical structure embodies the logical structure.
The SYSTEM object holds somewhat different information from that held in its matching FOCUS ENTRY, for two reasons: first, the FOCUS ENTRY serves additional purposes relating to object management by HANDLES; second, the FOCUS ENTRY stores an updatable logical position marker, whereas the logical position information held in the SYSTEM object on the TAIL of the file cannot be updated in any efficient way. This second difference requires further explanation.
The SYSTEM object retains information about the physical position that should be occupied by the object which it accompanies. This information is also often out-of-date, but the shortfall in information is made up by the sequencing of the SYSTEM objects on the TAIL of the file and the placement of the physical object location information into the recreated FOCUS ENTRY, where it can be updated as further changes occur.
The structure of the SYSTEM object is shown in FIG. 15A. The SYSTEM object consists of prefix 301 and suffix 302 bracketing a command 1502, virtual file position 1503, and reference object Magic String 1504. The command 1502 contains one of the choices listed in FIG. 15B. The Virtual File Position 1503 provides the necessary physical object location. The Reference Object Magic String 1504 provides the necessary logical object location.
FIG. 15A shows the structure of a SYSTEM object. The Command field indicates the kind of file alteration. The available alterations are here set forth in conjunction with the numerical values and purposes assigned to them in the preferred embodiment:
1. Insert--place following object(s) before reference object.
2. Append--place following object(s) after reference object.
3. Replace--replace reference object with following object(s).
4. Remove--remove the reference object from the file.
5. BeginT--note the beginning of a transaction.
6. EndT--note the end of a transaction.
7. AppendPrefirst--place following object(s) first in container.
8. InsertPostlast--place following object(s) last in container.
The `Virtual File Position` 1503 in FIG. 15A stores an unsigned long integer that indicates the physical file position at which the following object should begin if none of the preceding alterations in the TAIL of the file had taken place. This information is obtained from the FOCUS LIST when the alteration is COMMITTED, as described below in the section on the Object Control Scheme.
The `Reference Object Magic String` 1504 in FIG. 15A is a variable-length numeric sequence formatted like a numeric Dewey Decimal number, which represents the logical position of the reference object in the file. The section above on Symbolic Notation uses a printable representation of this value to indicate the logical positions of objects in the diagrams shown. The actual encoding of the `Magic String` is explained below in the section on the Object Control Scheme. The `Magic String` for the Reference Object is obtained from the FOCUS ENTRY for the current FOCUS when a HANDLE COMMITs an alteration.
The sequentially-appended SYSTEM objects preserve a copy of the MAGIC STRING of the reference object that was held in FOCUS by a HANDLE when the HANDLE made the change. Thus, if the SYSTEM objects are needed to reconstruct the FOCUS LIST that contains the FOCUS ENTRIES, each SYSTEM OBJECT can refer to an already-recreated FOCUS ENTRY that can be located by its unique MAGIC STRING in the FOCUS LIST, and the subsequent updating of the FOCUS ENTRY logical position by other file alterations can thereafter occur in memory.
I. Brackets and Token.
The defining characteristics of objects in the invention are that they are self-descriptive with respect to object size and type and that this self-descriptive quality is present in PREFIX and SUFFIX BRACKETs that comprise the beginning and end of each object in a byte stream. This level of generality allows object types to be defined for objects which can enclose virtually any kind and size of information, including other objects, and it provides a robust foundation for assuring object integrity.
An example of the format of an object is illustrated in FIG. 3A. An object is comprised of a PREFIX 301, BODY 302, and a SUFFIX 303. The PREFIX and SUFFIX are referred to individually as BRACKET and jointly as BRACKETS. The BRACKETS have closely similar structures and incorporate identical information.
The information necessarily incorporated by a BRACKET falls into the following categories: (1) BRACKET size, (2) object length, and (3) object type. The invention also provides (4) a parity bit, which is useful in checking object integrity, (5) a flag that indicates whether Extended Information is present within the object, and (6) a flag that indicates whether the object is operational or is a test object.
The invention comprehends the encoding within each bracket of either the actual object length or the offset to the opposing BRACKET. The opposing BRACKET can be located by various offsets, the most obvious ones being to the first or last bytes of that BRACKET, but the preferred offset to locate the opposing BRACKET is to the position of its KEYBYTE. The difference between the KEYBYTE offset and the length of the object is 1 byte, so that the adjustment is easily made to jump to the next adjacent object rather than to the opposing BRACKET. The description of the present invention expressed in this document is given in terms of encoding the full length of the object, which is the preferred embodiment.
The PREFIX 301 and SUFFIX 303 contain the same information and identify the length of the object encapsulated by the BRACKETS. That is, identical absolute object length values are encoded in the PREFIX 301 and SUFFIX 303. This makes it possible to jump forward to immediately past the end of an object by reading the PREFIX, or to jump backward immediately before the beginning of an object by reading the SUFFIX.
Each object ends with a SUFFIX KEYBYTE so that the SUFFIX KEYBYTE can be adjacent to the PREFIX KEYBYTE of any succeeding adjacent object. Similarly, each object begins with a PREFIX KEYBYTE so that the PREFIX KEYBYTE can be adjacent to the SUFFIX KEYBYTE of any preceding adjacent object.
The rule that KEYBYTEs of physically adjacent objects are themselves adjacent is subject to exception in the cases of a CONTAINER object and the first and last contained objects. As shown in FIG. 4D, the PREFIX KEYBYTE of the first contained object 405 lies immediately after the PREFIX 404 of the CONTAINER 403, and the SUFFIX KEYBYTE of the last contained object 407 lies immediately before the SUFFIX 405 of the CONTAINER.
In the preferred embodiment, each BRACKET of an object holds four categories of information: BRACKET size, object length, object type, and BRACKET parity. In other embodiments, different numbers and kinds of categories of information may be held by a Bracket. In addition, extended information falling into several categories mentioned above is present in the BRACKETS if so indicated in each BRACKET. The order of information differs between PREFIX and SUFFIX, but the substance of the information is identical. The preferred embodiment is given below.
The first and last bytes of an object are the KEYBYTEs of the object's BRACKETS. Each KEYBYTE provides information that is essential to the self-description of the object. In an extreme case in which a DATA object is ABSENT, the first and last bytes are merged into a single-byte TOKEN.
A BRACKET can vary in size from one byte to six bytes in the preferred embodiment. As a general principle, the larger BRACKET sizes are required in order to include sufficient bits to encode larger object lengths, as illustrated in the preferred embodiments shown for PREFIX and SUFFIX, below. Note that there is no inherent limit to the size of the PREFIX or SUFFIX.
Each BRACKET contains TYPE information, which generally identifies an object as CONTAINER, DATA or SYSTEM, but also provides further detail for sub-categories of object TYPE. A TOKEN, which is a combined SUFFIX/PREFIX of one byte in length, is by definition a DATA object, so it contains only the 5 bits necessary to identify the TYPE subcategories of DATA. All other BRACKETs include a separate TYPE byte, so the smallest non-TOKEN BRACKET is two bytes in length.
Each BRACKET indicates whether Extended Information is present. FIGS. 3A and 3B illustrate the placement of the optional Extended Information structure. The BODY 302 of an object is decomposed in FIG. 3B, wherein the optional Extended Information structure 304 is shown to precede the CONTENT 305. The Extended Information structure holds information that characterizes the object.
Although the KEYBYTE is part of a BRACKET, its structure is described in advance of that of the overall BRACKET as an aid to understanding. The reason for this is that a BRACKET is not defined as having a fixed size and the KEYBYTE holds the essential BRACKET size information.
FIGS. 3A and 4A illustrate the composition of a PREFIX 301, in which the KEYBYTE 401P is followed by the PREFIX REMAINDER 402P and then by the object BODY 302. FIGS. 3A and 4B illustrate the composition of a SUFFIX 303, in which the object BODY is succeeded by the SUFFIX REMAINDER 402S and then by the KEYBYTE 401S.
The KEYBYTE describes the size of the BRACKET of which it is a part (the only part in the case of a TOKEN). From the length of the BRACKET it is possible to ascertain the size and the location of the rest of the BRACKET: for PREFIX BRACKETs the KEYBYTE is the first byte, and for SUFFIX BRACKETs the KEYBYTE is the last byte.
Computer systems and platforms that use the file system of the present invention are capable of reading a single byte at one time. Jumps between adjacent objects within a CONTAINER thus become one-byte jumps forward from the SUFFIX key byte of one object to the PREFIX key byte of the next object, or one-byte jumps backward from the PREFIX key byte of an object to the SUFFIX key-byte of the preceding object. This illustrates why the internal byte-orderings of PREFIX and SUFFIX order are not identical, although the PREFIX and SUFFIX contents are identical.
Each KEYBYTE also includes a parity bit, which is set to match the parity of the other bits in the BRACKET. The presence of this parity bit facilitates the detection of corruption in the BRACKET itself and in the entire object.
In the preferred embodiment, the size encoding of a KEYBYTE is represented by a bitstream of `1` value bits, terminated by a `0` value bit. The bitstream could proceed from Most Significant Bit downward or from Least Significant Bit upward; in the preferred embodiment the latter method is used. The position in which a `0` bit value is first encountered (counting from 1 upwards) represents the number of bytes in the BRACKET, including the KEYBYTE.
This scheme may be represented by `0` and `1` values for bits that are meaningful and `x` values for bits that are not considered. Thus, in a TOKEN the Least Significant Bit (which is in position 0) holds a `0` value in the sequence `xxxxxxx0`, indicating that the BRACKET is 1 byte in length. In a two-byte BRACKET the Least Significant Bit holds a `1` value and the next most significant bit holds a `0` value which terminates a two-bit sequence of `xxxxxx01`, where `x` represents bits that are not considered. Likewise, in a three-byte BRACKET the three-bit sequence is `xxxxx011`. Note that in this representation the bit positions are represented as 76543210, with 0 as the Least Significant Bit position.
In concept, the KEYBYTE need not contain any information other than BRACKET size, because the balance of the BRACKET can be encoded to contain all other essential information, such as object length and object TYPE. In the preferred embodiment, however, it has proven convenient to employ for other purposes the bits that are unused for size encoding.
The preferred embodiments of BRACKETS are set forth below for PREFIX and SUFFIX. Note that the TOKEN representation appears identically as the 1-byte size BRACKET for PREFIX and SUFFIX. For the purpose of representing bit-level encoding of BRACKETS, the following symbols are used:
`P` is a parity bit
`E` is an extended information presence bit
`X` is a test object indicator bit
`T` is an object type encoding bit
`L` is a object length encoding bit
`S` is a BRACKET size encoding bit
Bit positions are represented in the order of 76543210, with position 0 being the Least Significant Bit.
The KEYBYTE of a BRACKET has already been described. The structures of the remaining components are now described under the categories of prefix, suffix, token and extensions, which differ from one another.
A detailed view of the PREFIX is illustrated in FIG. 4A. The PREFIX 301 consists of a KEYBYTE 401P followed by the PREFIX remainder 402P. The PREFIX KEYBYTE 401P identifies the length of the PREFIX 301 and correspondingly, the length of the PREFIX remainder 402P.
A representation of PREFIX structures from one byte to six bytes in length is illustrated in Table 1 below:
TABLE 1__________________________________________________________________________Layout of a PREFIX (KEYBYTE is the leftmost byte):__________________________________________________________________________1-byte PTTTTTXS2-byte PLLLLLSS TTTTTTXE3-byte PLLLLSSS LLLLLLLL TTTTTTXE4-byte PLLLSSSS LLLLLLLL LLLLLLLL TTTTTTXE5-byte PLLSSSSS LLLLLLLL LLLLLLLL LLLLLLLL TTTTTTXE6-byte PLSSSSSS LLLLLLLL LLLLLLLL LLLLLLLL LLLLLLLL TTTTTTXE__________________________________________________________________________
As shown above, in a two byte PREFIX, the `L` bits in bit positions 6, 5, 4, 3, and 2 of the KEYBYTE indicate the length of the object (i.e. the offset to the next object). A two byte PREFIX is used to represent an object up to 31 bytes in length. A three byte PREFIX uses bit positions 6, 5, 4, and 3 of the KEYBYTE, and one length byte, to indicate object length. A three byte PREFIX is used to represent an object up to 4095 bytes in length. A four byte PREFIX has three length bits in the KEYBYTE and two length bytes, and is used to represent an object up to 524,287 bytes in length. A five byte PREFIX has two length bits in the KEYBYTE and three length bytes, and is used to represent an object up to 67,108,863 bytes in length. A six byte PREFIX has one length bit in the KEYBYTE and four length bytes, and is used to represent an object up to 8,589,934,589 bytes (approximately 8 gigabytes) in length. These BRACKETS are the preferred embodiment, but the invention comprehends the possibility of representing even larger objects with yet largest BRACKETS.
A detailed view of the SUFFIX is illustrated in FIG. 4B. The SUFFIX 303 consists of a KEYBYTE 401S preceded by the SUFFIX remainder 402S. The SUFFIX KEYBYTE 401S identifies the length of the SUFFIX 303 and correspondingly, the length of the SUFFIX remainder 402S.
A representation of SUFFIX structures from one byte to six bytes in length is illustrated in Table 1 below:
TABLE 2__________________________________________________________________________Layout of a SUFFIX (KEYBYTE is the rightmost byte):__________________________________________________________________________1-byte PTTTTTXS2-byte TTTTTTXE PLLLLLSS3-byte TTTTTTXE LLLLLLLL PLLLLSSS4-byte TTTTTTXE LLLLLLLL LLLLLLLL PLLLSSSS5-byte TTTTTTXE LLLLLLLL LLLLLLLL LLLLLLLL PLLSSSSS6-byte TTTTTTXE LLLLLLLL LLLLLLLL LLLLLLLL LLLLLLLL PLSSSSSS__________________________________________________________________________
The object lengths which can be encoded in a SUFFIX are the same as those for the PREFIX of the same size.
A one byte combined PREFIX-SUFFIX is referred to as a TOKEN, which is used to represent a non-value DATA object of the given type. The preferred embodiment of a TOKEN is shown identically as the 1-byte versions of PREFIX and SUFFIX. The TOKEN is used to indicate the absence of an expected value of the indicated DATA type: by definition, a TOKEN is a DATA object. The TOKEN, like other BRACKETs, contains one bit denoted above as the `X` bit: this is used to indicate that the TOKEN is a test object, which may be specially handled by a program that employs the invention. Non-value instances other than `absent` are not denoted by a TOKEN, but rather by an object of the same TYPE with full BRACKETS, as described below in the section on object TYPEs.
The two BRACKETs of each object hold identical TYPE information that characterizes the object. For a PREFIX or SUFFIX of two bytes or larger, there is a separate TYPE byte, which covers all object types. The TYPE byte is at the end of each PREFIX and at the beginning of each SUFFIX. The TYPE byte provides information about the object depending on the values of specific bits in the byte. The preferred embodiment of the TYPE byte is illustrated in detail in FIG. 2. A TOKEN, which is by definition a DATA object, contains the subset of 5 bits from a TYPE byte which is used to represent DATA object types.
The TYPE system required by the invention requires that each BRACKET be able to represent a range of at least 10 unique object types, each of which is mentioned in this section (there are eight sub-types of DATA, plus CONTAINER and SYSTEM objects). In the preferred embodiment, these values are represented in 6 of the 8 bits of one byte in each BRACKET, and as a consequence that byte is referred to as the `TYPE BYTE`. An exception is made for the one-byte TOKEN, which is by definition a DATA type of object, so it need contain only the 8 subtypes that are defined for DATA objects. Note that the numerical type identifications that can be stored in the TYPE BYTE exceed the 10 TYPES defined for the present invention, so there is ample room for extension of the typing system within the preferred embodiment. The structure of BRACKETS and of the TOKEN are discussed below.
Every object except a TOKEN can store further sub-typing in an optional Extended Information Structure that lies within the BRACKET of an object.
All typing serves the same purposes: to associate objects with unique behaviors defined for the object contents by the invention, and to separate different data value representation schemes from one another.
In the present invention, objects written to file as one type can only be recovered from the file as that type: for example, an integer written to file can be identified later as an integer and can only be read as an integer; a CONTAINER object written to file can only be managed as a CONTAINER and cannot be mistaken for an integer or any other DATA object. SYSTEM objects are not exposed to programmers through the API, but the same rule applies that the object is distinguished by TYPE and cannot be manipulated by functions appropriate to a different object TYPE.
The reason for defining multiple sub-types is to allow the differentiation of object behaviors which facilitate data storage and manipulation. The behaviors described below for each particular TYPE are specific to that TYPE in the invention and must be enforced by any implementation of the invention.
J. Extended Information.
The present invention provides for the optional inclusion of an Extended Information structure within any object. The preferred embodiment is shown in FIGS. 14A through 14G.
Extended Structure Block A 1401 is present if the `E` bit in the BRACKET is set. The structure of Blocks A 1401, B 1402 and C 1403 are shown in FIGS. 14B, 14C, and 14D. In each Block, the Size component 1404, 1407 and 1410 is a byte that holds a flag in the high bit; if the high bit is 0, the size encoded in the lower 7 bits is the offset to the enclosed content 305; if the high bit is 1, the size encoded in the lower 7 bits is the offset to the next Block, which itself begins with a Size byte. For example, if Block B 1402 is present, the high bit of the Size byte 1407 is 0 if the lower 7 bits hold the offset to the object content and 1 if the lower 7 bits hold the offset to the next Block. FIGS. 3A and 3B show the relative placement of object CONTENT 305 immediately following the optional Extended Information structure 304, which together make up the object BODY 302.
As shown in FIG. 14E, the Flags component 1405 of Block A is a byte in which the bits are used as follows:
______________________________________bit number significance if set to 1______________________________________7 1-byte Type Map is present6 8-byte (64 bit) ID is present5 2-byte Class Number is present4 1-byte decryption method index is present3 1-byte decompression method index is present2 component of 3-bit checksum method index1 component of 3-bit checksum method index0 component of 3-bit checksum method index______________________________________
As shown in FIG. 14F, the Flags component 1408 of Block B is a byte in which the bits are used as follows:
______________________________________bit number significance if set to 1______________________________________7 1-byte Platform Type is present6 2-byte modification time stamp is present5 2-byte Access Id is present4 1-byte access rights value is present3 1-byte access grade value is present2 Id Access flag: Access Id required1 1 to 40 byte name string is present0 1 to 80 byte comment string is present______________________________________
As shown in FIG. 14G, the Flags component 1411 of Block C is a byte in which the bits are used as follows:
______________________________________bit number significance if set to 1______________________________________7 2-byte Class Number is present6 2-byte modification time stamp is present5 2-byte access id is present4 1-byte access rights value is present3 1-byte access grade value is present2 Id Access flag: Access Id required1 1 to 40 byte name string is present0 1 to 80 byte comment string is present______________________________________
Block C is used when the object is encrypted. In that case, the information listed above for inclusion in BLOCK C is copied from the identical values in BLOCK A (Class Number) and BLOCK B (all other elements) and then deleted from the origin. The entirety of BLOCK C is then encrypted separately from the object CONTENT 305 but with the same password; thus, an authorized user can attempt to decrypt the object with the correct password, but the required access rights and HANDLE ID can be checked by decryption of BLOCK C and comparison of the values with the current HANDLE ID and rights before the object decryption will proceed.
The present invention comprehends the possibility that the information shown structured as above in the preferred embodiment might also be represented by a structure based on larger size and flag components, such as 16 bits rather than 8 bits; in such as case there might be no need to "daisy chain" blocks, so all of the Extended Information might be kept in one block.
The defining capability of the Extended Information structure is that the presence of every element other than the size and flag information is optional, so that no space is used unless the information element is present (which will be indicated by the appropriate flag bit). Furthermore, even the size and flag components are not present when no Extended Information element is present (in which case the BRACKETS will indicate that no Extended Information is present).
Type. When the `Type` flag is set, the matching `Type` field contains an 8-bit number which identifies the value mapping system which applies to the contents of the object. This value is by definition type-specific. The mappings presently used in the preferred embodiment are as follows:
______________________________________Affected TYPE Bit Pattern Meaning______________________________________CHAR and STRING 00000000 null 00000001 ASCII symbols: 7-bit 00000010 UNICODE-2 symbols: 16-bit 00000100 ASCII symbols: 8-bit 00001000 UNICODE-4 symbols: 32-bitSIGNED INTEGER 00000000 positive infinity 00000001 Not a Number 11111111 negative infinityUNSIGNED INTEGER 00000000 positive infinity 00000001 Not a Number______________________________________
In the case of CHAR and STRING objects, the HANDLE facility, provided by the invention for the manipulation of objects, exists at all times in a symbol-specific state, which can be modified at any time. This state determines the storage space allocated for each CHAR object (or CHAR in a STRING) and the acceptable value ranges which may be appropriately assigned for that symbol set. The Type map for CHAR/STRING is maintained as a HANDLE state, but the map is not placed into an Extended Information Structure when an object is created unless an appropriate API call is made through the HANDLE.
The 16-bit and 32-bit UNICODE representations use symbol mappings for many languages (including alphabetic and ideogram systems) promulgated by the UNICODE CONSORTIUM and now being adopted as an ISO (International Standards Organization) standard. The invention allows assignment of these symbol sets to CHAR and STRING objects, as mentioned above, which permits the invention to manage text with mixed languages.
Identifier. When the `Identifier` flag is set, the `Identifier` field contains a 64-bit number that is unique to the object. Each computer on which the invention is used is set up with a unique node identifier in a configuration file to assure universal uniqueness of the identifier, because the node identifier number provides part of the 64 bits of value. The invention maintains its own unique object sequence numbering that is applied to the other bits. This numbering system facilitates the association of objects with one another by programs which use the invention.
Class Number Because the objects of the present invention may be used for persistent file storage in support of object-oriented programming under circumstances where the structure and behaviour of objects are defined beyond the scope of the invention, provision is made by the invention to allow programmers to assign numbers to objects as a means of identifying them as instances of classes.
For example, a programmer might choose to assign the number `87` to a particular data structure that serves as a node in a linked list in computer memory. The data elements of that structure could be represented in the invention as DATA values of the sub-types chosen by the programmer, and the whole structure would consist of a CONTAINER object holding those contents; in this example, every instance of such a CONTAINER in an MFILE would have the value `87` in the `Type` element of the Extended Information structure of the CONTAINER.
Encryption. When the `Encrypted` flag is set, the value present in the `Decryption Method` field is a number that indicates which encryption method was used. A user-definable configuration file is used by the invention to associate the user-assigned number with a decryption algorithm or program. Decryption Method `0` is reserved as unspecified, leaving to the programmer the responsibility for choosing the correct algorithm. The actual content of this element is implementation specific.
Compression. When the `Compressed` flag is set, the value present in the `Compression Method` field is a number that indicates which compression method was used. A user-definable configuration file is used by the invention to associate the user-assigned number with a decompression algorithm or program. The actual content of this element is implementation specific.
Checksum. Three bits are used for the `Checksum` flag, which allows it to serve directly as an information element. If the three bit element holds a non-zero value, there is a `Checksum Amount` element in the Extended Information structure that holds the checksum calculated on the object BODY 302, which is shown in FIG. 3A. The `Checksum Method` element contains a number that indicates which checksum method was used (which also implies the storage size for the calculated checksum), and the `Checksum Amount` field contains the calculated checksum. If the object content is intact, a re-calculation of the checksum at the time of a READ action will confirm the result that was stored in the `Checksum Amount` element.
Referencing FIGS. 3A and 3B, the checksum is applied to the object BODY 302, which includes the optional Extended Information structure 304. The checksum is not applied to the object BRACKETS. In the case of a CONTAINER object, all parts of all contained objects are included in the checksum; in the case of a DATA object, only the enclosed data value or values are included.
Platform. This information categorizes computer platforms, which consist of computer processors combined with operating systems and in some cases with compilers, so that the characteristics of the platform on which the object data value was created can be stored with the object. This permits implementation of the invention to make any platform-specific adjustments that may be necessary. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Date and Time. This item stores the most recent data modification date of an object (the creation date, at first). The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Access Identifier. This item stores a programmer-supplied identifier which was used at creation of the object and which, if the `Id Access Flag` discussed below is set, must be submitted by any HANDLE in order to access the content of the object. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Access Rights. This item stores the rights which must be possessed by a HANDLE in order to access the content of the object. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Access Grade. This item stores the supervisory level which must be possessed by the HANDLE in order to access the content of the object. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Id Access Flag. In the event that an Access Identifier was used to create an object, the requirement that the same identifier must be present in any HANDLE accessing the object is subject to an ON/OFF toggle controlled by this flag. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Name. Any object may be assigned a null-terminated string name, using any binary single-byte values in the string (except that a null will terminate the string). In the preferred embodiment this string may be up to 32 characters in length. Symbol mapping for this element is controlled by the Type Map in the Extended Information structure. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
Comment. Any object may be assigned a null-terminated string comment, using any binary single-byte values in the string (except that a null will terminate the string). In the preferred embodiment this string may be up to 80 characters in length. Symbol mapping for this element is controlled by the Type Map in the Extended Information structure. The actual content of this element is implementation specific and not a part of this invention, but the inclusion and placement of storage for this category of information within the object is part of the invention.
K. Magic String.
The MAGIC STRING is a component of the invention that is employed to represent the logical position of an object within the MFILE. The MAGIC STRING is a null-terminated value of variable length which has a binary representation that may be envisioned as a Dewey Decimal number in which containment levels are separated by periods and cardinal positions within a contained level are represented by positive integer numbers.
The MAGIC STRING is present in each FOCUS ENTRY on the FOCUS LIST which has a logical position in the MFILE (NOTE: a REMOVED object has no logical position in the file). The values of the MAGIC STRINGs are the basis for sorting the FOCUS LIST entries in logical order of object PREFIX positions. For example, the FOCUS ENTRIES for contained objects will be placed in the FOCUS LIST after the FOCUS ENTRY of their CONTAINER and before the FOCUS ENTRY for any object represented in the FOCUS LIST that is logically located after that CONTAINER at the same level as the container. The rules for sorting are discussed later in the FOCUS LIST topic.
Object logical positions are encoded in the bytes of a MAGIC STRING as follows in the preferred embodiment: 1. beginning at the start of the byte sequence, cardinal object position at each level is encoded in a series of bytes in which the value is stored in the 7 low-order bits and the single high-order bit is used as a flag to indicate the end of the series (the end may be thought of as a `period` in a Dewey Decimal number); 2. the value bits of the bytes in the series are packed together, in the preferred embodiment, in a 32-bit variable, padded with `0` bits in the high order range; and 3. in the preferred embodiment, the 32-bit variable is interpreted as an unsigned long integer to obtain the cardinal position of the CONTAINER at any nesting level and to obtain the cardinal position of the object at the deepest nested object represented in the MAGIC STRING. Thus, for each level represented there is a byte with a high-order bit set to `1`, the last of which is succeeded by a null terminating byte.
The encoding described in the preceding paragraph is illustrated in FIGS. 16A, 16B and 16C. FIG. 16A shows a MAGIC STRING that represents an object nested inside a CONTAINER, in which the MAGIC STRING has 3 components: a byte series for level 1, a byte series for level 2, and a null terminating byte. A byte series consists of 1 or more bytes. FIG. 16B illustrates a byte series consisting of 3 bytes, of which the value bits are represented by letters A, B and C, and the terminating flag bit is represented by the number `1`. FIG. 16C shows the result of packing the value bits together into a 32-bit variable, left-padded with `0` bits, which yields an integer number that gives the cardinal position of the object at the represented level.
L. Handle and Focus.
The present invention includes a programming facility, known as a "HANDLE", which both allows and controls access to objects within an MFILE. The HANDLE ensures fiat access to an MFILE is performed in a manner consistent with the file structure which is dictated by the invention. Each file of the present invention is itself an "object" which can contain any number of objects within it. A HANDLE references one object at a time--that is, the file as a whole or some object within the file. The reference to an object by a HANDLE is called FOCUS. The FOCUS of the HANDLE is unaffected by the logical expansion of the file in areas closer to the beginning of the file, even though that expansion apparently alters the offset of the objects that are farther out in the file.
A HANDLE is in one of four positional states at a given time. The most common state, which it assumes at inception, is to have FOCUS on an object (the initial object is the HEAD of the MFILE). The other three states pertain to positions within a CONTAINER object whenever no specific object is in FOCUS: the HANDLE may assume a `pre-first` or `post-last` position, or it may be placed in a `null` position. The `pre-first` position is used to append objects in reverse order into the FIRST position in a CONTAINER. The `post-last` position is used to insert objects in order into the LAST position in a CONTAINER. The `null` position results when the HANDLE moves into an empty CONTAINER or when the HANDLE removes the last object from a CONTAINER, thereby causing the CONTAINER to become empty.
When an object is in FOCUS, its TYPE and size and Extended Information are accessible by QUERY action, and if the object is a DATA object then its stored data values are accessible by READ action. When a HANDLE changes FOCUS from one object to another, the process is called NAVIGATION.
M. Navigation.
NAVIGATION is defined as the activity of moving the focus of a HANDLE from one object to another object or into a non-FOCUS positional state. Adjacent objects are reached by "next" and "prior" commands. Contained objects are reached by a "move in" command, and CONTAINER objects are reached by a "move out" command. (The exact names associated with the foregoing navigation moves are not essential to the invention).
When a HANDLE NAVIGATEs into a CONTAINER, it must take one of two positions: if the CONTAINER contains any objects, the HANDLE will gain FOCUS on the first contained object; otherwise the HANDLE will obtain a `null` FOCUS. From any FOCUS, including from a `null` FOCUS, the HANDLE may NAVIGATE to the `pre-first` or `post-last` positions, which are discussed below. A HANDLE may not obtain a `null` FOCUS by any means other than by causing a REMOVE of the last contained object in a CONTAINER or by NAVIGATING into an empty CONTAINER. A HANDLE may move out of a CONTAINER from any FOCUS inside the CONTAINER and from any non-FOCUS position.
The HANDLE may not perform alterations from a `null` FOCUS: this may be done only from an object FOCUS or from the `pre-first` or post-last` positions, because every MFILE alteration must take place in reference to an object position. An object in FOCUS provides a point of reference for any additive alteration. The `pre-first` position provides a point of reference for APPEND actions only; and the `post-last` position provides a point of reference for INSERT actions only.
Navigation of a HANDLE into and out of a CONTAINER object is managed by retaining in the HANDLE a stack of references to FOCUS LIST ENTRIES which represent the current hierarchy of nested CONTAINERs into which the HANDLE has navigated in order to obtain its current FOCUS. FIGS. 17A and 17B illustrate the stack of CONTAINER FOCUS ENTRY references maintained in two separate HANDLEs and the referenced FOCUS ENTRIES on the FOCUS LIST.
N. Queries.
Any object that is in FOCUS may be subjected to a QUERY for TYPE, object size, buffer size required for variable-length data values, such as BINARY TYPE, and any item that may be contained in its Extended Information structure. The storage size query is defined only for DATA objects, and it returns the size of memory variable that is required to receive the value READ from the DATA object. The object size QUERY returns the inclusive size of the object. The available QUERIES for Extended Information may be deduced from the listing of items contained in Extended Information; however, only the existence--not the value--of Checksum, Encryption, Compression, Access Rights and Access Grade will be revealed by implementations of the invention.
O. Reads.
The value content of any DATA object can be READ when the object is in FOCUS. The invention requires that the READ action be accompanied by a variable supplied by the programmer to receive data of that DATA TYPE. If the wrong type of variable is supplied, an error will be returned. If the DATA value is of a TYPE that has a non-fixed length, the required storage length for a receiving memory variable is available through a QUERY action.
The value content of a DATA object is accessed by reading the KEYBYTE of the PREFIX and jumping forward the length of the PREFIX (or by reading the KEYBYTE of the SUFFIX and jumping backwards the length of the SUFFIX). Accessing the first contained object consists of jumping forward from the KEYBYTE the length of the PREFIX of the CONTAINER, and accessing the last contained object consists of jumping backward from the KEYBYTE the length of the SUFFIX. As a practical matter, enclosed DATA is usually read `forward`, so access from a SUFFIX would usually include the extra step of jumping backward over the length of the DATA to its beginning. This means of access to an object is used in the invention automatically to build memory structures called FOCUS ENTRIES, which are later described.
DATA objects are always given specific sub-TYPEs. In the preferred embodiment, the minimal DATA TYPEs are SIGNED INTEGER, UNSIGNED INTEGER, FLOAT, CHAR, STRING, BOOLEAN, BINARY, and ENUMERATION, each of which has been mentioned above.
P. Alterations.
Whenever a file alteration occurs, the logical position of various file objects may be changed. The only logical object positions that matter are the ones represented on the FOCUS LIST, and for those the invention automatically updates the `Magic String` values in the FOCUS ENTRIES as needed, so the value is up-to-date at all times, even if multiple HANDLES are operating on separate threads of execution.
When alterations are to be made to an object, the present invention permits the alteration to be made before the current FOCUS, after the current FOCUS, replacing the object at the current FOCUS, or removing the object in current FOCUS. An alteration made immediately before the FOCUS is referred to as an `insert`. An alteration made immediately after the FOCUS is referred to as an `append`. The FOCUS itself may be unchanged, or it can move automatically to the new object. In `remove` operations the object in FOCUS becomes unaccessible, so the FOCUS moves automatically to an adjacent object, in the preferred order of `next`, `prior`, and `null`.
Every additive alteration (insert, replace, append) creates a new object. When an additive alteration action is invoked, the system (1) creates a receiving buffer; (2) marks the buffer to indicate the alteration type; (3) receives the DATA written into the buffer; and (4) removes or posts the buffer to a serialized UPDATES QUEUE, where the contents of the buffer appear as a SYSTEM object followed by the added object. In case of `remove` invention posts to the UPDATES QUEUE only the information required to build a SYSTEM object.
In the preferred embodiment the intended alteration must be declared through the HANDLE before any content is written to the receiving buffer, and the successful completion of the update must be accomplished by a COMMIT action. The COMMIT action causes the receiving buffer to be posted to the UPDATES QUEUE. An alteration pending in this sequence may also be ABANDONED, in which case the receiving buffer is erased and nothing is posted to the UPDATES QUEUE. An ABANDON or COMMIT action terminates the alteration.
The process of alterations may be illustrated by creating an example file. Such an example is illustrated in FIGS. 5A-5C. Consider the situation of creating a file to store address information for the following: Acme Corporation, New York, N. Y. 10022 212-123-4546. Referring to FIG. 5A, a CONTAINER 501 is created. Referring now to FIG. 5B, a second CONTAINER 502 is created within CONTAINER 501. CONTAINER 502 includes four DATA objects 503, 504, 505, and 506. DATA object 503 stores the "name" value (e.g. Acme Corporation). DATA object 504 stores the "city" value (e.g. New York). DATA object 505 stores the "state" value (New York), DATA object 506 stores the "zip" information (10022). There is no need to restrict the size of the DATA objects to a predetermined size, nor is there a need for external indexing information to locate individual values, because the BRACKETS provide information needed to navigate easily through the file.
Consider now the situation where a programmer desires to modify the logical file to provide a second name DATA object (e.g., a contact person) and a phone number as part of the file, and desires that the new information be located at the beginning of the file. Referring to FIG. 5C, a new CONTAINER 507 is created and added to the file in front of and at the same level as CONTAINER 502. The new CONTAINER 507 includes DATA objects 508 name2", and 509 phone".
FIGS. 10A-10C illustrate the state of the physical file stored in memory during the creation and manipulation of the logical file of FIGS. 5A-5C. Referring first to FIG. 10A, there is stored in memory a CONTAINER 1001 that is a representation of the logical CONTAINER 501.
Referring now to FIG. 10B, when a change is made to a logical file, a "SYSTEM object" 1020 is created that contains information about how the information added in FIG. 5B to the logical file is added, the logical relationship between the additional information and the existing information, when the change is made, etc. The SYSTEM object is written at the end of the existing file, (in this case, at the end of CONTAINER 1001) along with the additional file information, new CONTAINER 1002 and DATA objects 1003-1006. The SYSTEM object contains all the information necessary to place its associated DATA logically in the file.
Referring now to FIG. 10C, another SYSTEM object 1021 is written for the second name and phone number DATA objects to be added to the file in a new CONTAINER. The second command object 1021 is appended at the physical end of the stored file even though logically, the information is added at the beginning of the file. Following the command object 1021 is the new CONTAINER 1007, and new DATA objects 1008 "name2" and 1009 "phone".
Q. Updates Queue.
The UPDATES QUEUE receives alterations to the MFILE and serializes their effect on the MFILE. The updating procedure is a follows: (1) the write object is obtained from the UPDATES QUEUE; (2) a SYSTEM object is written to the TAIL of the MFILE; (3) the alteration is implemented: a new object is added to the TAIL of the MFILE, the FOCUS is modified or a new FOCUS ENTRY is created; and necessary DATA length changes and logical position changes are made to FOCUS ENTRIES for all enclosing CONTAINERS that have their object lengths changed by the alteration. The use of a separate thread of execution for updates processing is an option, not a requirement, of the invention.
When a HANDLE makes a change to a file, a description of that change is placed in an UPDATES QUEUE, which is a linked-list of buffers or pointers to buffers in memory. The UPDATES QUEUE is a FIFO list. The UPDATES QUEUE is used to serialize the updates to a file. This facilitates DATA integrity when multiple handles are attempting to make changes to a file. When changes are made to the file, changes are made from the UPDATES QUEUE in serial order and written onto the TAIL of the file. Some alterations are time intensive. Use of the UPDATE QUEUE allows a HANDLE to put the update into the queue and then proceed with other activity.
R. Focus Entry.
The FOCUS ENTRY holds a unique logical position marker called a MAGIC STRING that is updated in memory whenever a file alteration occurs that changes the logical position of the object referred to by the FOCUS ENTRY. By contrast, a SYSTEM object, which holds the information needed to rebuild the FOCUS ENTRY in case of computer process interruption, is designed to be written to file, where access for the purpose of updating logical position information is most awkward. For this reason, the SYSTEM object contains the MAGIC STRING of the reference object which was current at the time the ALTERATION represented by the SYSTEM object was processed.
The format of the FOCUS ENTRIES in the FOCUS LIST is illustrated in FIG. 13. The entry 1300 begins with a user count 1301 that tracks the number of HANDLEs focusing on the object or using the FOCUS ENTRY. The needed count 1302 indicates how many unprocessed alterations have the FOCUS as a reference and how many HANDLES have the object in FOCUS or have a contained object in FOCUS. Object information 1303 stores object variables, including the PREFIX KEYBYTE location, the object CONTENT location, the BRACKET size, and the object length. Only the location of the PREFIX KEYBYTE is required, but it is useful to maintain additional information in the FOCUS ENTRY to improve efficiency by reducing file access. Flags 1304 identify an object as pending removal or pending replacement.
The MAGIC STRING 1305 stores information about the logical position of the PREFIX KEYBYTE of an object in the MFILE. The logical position of the PREFIX KEYBYTE is the basis of sorting of the FOCUS LIST. The logical ordering of the PREFIX KEYBYTEs is defined as the order of the locations at which the PREFIX KEYBYTEs of objects will appear in the HEAD of an MFILE after RECONSTITUTION, which is an order that by definition excludes duplication since only one KEYBYTE can appear at a physical location in a file. The comparison of MAGIC STRINGs of FOCUS ENTRIES yields this order.
REMOVEd objects present a complication, because they will have no physical position in the RECONSTITUTED file. This complication is solved by marking the FOCUS ENTRY for a REMOVEd object and keeping that FOCUS ENTRY in the FOCUS LIST position that it held immediately before removal, relative to other FOCUS ENTRIES on the FOCUS LIST.
An additive ALTERATION (INSERT, REPLACE and APPEND) yields a FOCUS ENTRY that is placed on the FOCUS LIST in position relative to the FOCUS ENTRY of the object which served as a reference for the ALTERATION. As a result, the FOCUS ENTRY for an APPENDed object always follows the FOCUS ENTRY for its reference object, and the FOCUS ENTRY for an INSERTed object always precedes the FOCUS ENTRY for its reference object. Initially, these FOCUS ENTRIES are adjacent; later ALTERATIONs may separate those FOCUS ENTRIES with new FOCUS ENTRIES, but the relative positions on the FOCUS LIST of the FOCUS ENTRY for the added object and the FOCUS ENTRY for the reference object are never switched.
The result of these sorting rules is that the FOCUS LIST represents the logical ordering and prospective physical placement of all objects that must be copied to a new MFILE when RECONSTITUTION takes place. The FOCUS LIST also serves as the central reference point for logical NAVIGATION of the MFILE, which is accomplished by walking the FOCUS LIST (adding FOCUS ENTRIES along the way for unrepresented MFILE objects that are encountered).
S. Focus List.
Information about the logical position of old and new objects in a file must be available in order for HANDLES to navigate on the file and in order to reconstruct the file in logical order. This information is stored in a combination of memory structures called "FOCUS ENTRIES", logical position values known as "MAGIC STRINGS", and a compilation of the focus entries called a "FOCUS LIST". Information needed to re-create these memory structures after an unexpected computer shutdown is kept in SYSTEM objects which are written to the TAIL of a file as part of the updating procedure.
The fact that an object exists in an MFILE does not itself create a need for that object to be represented by a FOCUS ENTRY on the FOCUS LIST. A FOCUS ENTRY needs to exist for an object only when one or more of the following conditions is met: 1. The object is held in FOCUS by a HANDLE. 2. The object is a CONTAINER and some HANDLE has FOCUS on an object inside the CONTAINER. 3. The object has been REMOVED logically from the MFILE but it is still in the physical MFILE because RECONSTITUTION has not yet taken place. 4. The object was used as reference for an ALTERATION which has not yet been processed.
When an object in FOCUS is nested within one or more levels of CONTAINER objects, the HANDLE keeps track of every focus entry which represents one of the enclosing CONTAINER objects, even though it might be the case that none of the CONTAINER objects is directly referenced by a HANDLE. The FOCUS ENTRY is retained in memory as part of the FOCUS LIST as long as there is a HANDLE which has focus on a contained object at a lower level. Thus, each HANDLE retains a stack of references that point at the FOCUS ENTRIES which represent containing objects. That reference provides information to prevent NAVIGATION beyond the boundaries of the retaining objects.
Any object that has been added to the TAIL Of the MFILE also has an entry in the FOCUS LIST until the file has been reconstituted or the object has been removed. Any object that has been removed from the HEAD of the file has an entry in the FOCUS LIST until it has been physically removed from the file by RECONSTITUTION. This makes it possible to track the logical positions of objects added to the file, without having to read the file and its associated SYSTEM objects, and it makes the RECONSTITUTION algorithm simpler.
FOCUS LIST entries that are not needed to support the current FOCUS of a HANDLE are eliminated by the RECONSTITUTION procedure. Any object that has been added to the TAIL of the MFILE and then REMOVED prior to RECONSTITUTION need only have its FOCUS ENTRY removed from the FOCUS LIST: because it lacks a FOCUS ENTRY, it will not be copied to the HEAD of the MFILE during a subsequent RECONSTITUTION. A more detailed discussion of RECONSTITUTION is presented in a later section.
FIG. 11 illustrates the FOCUS LIST of the present invention. A FOCUS LIST 1100 includes a number of entries 1101, 1102, 1103, etc. Each entry in the FOCUS LIST 1100 is referred to as a FOCUS ENTRY. Each FOCUS ENTRY represents an object in the file.
Consider the file consisting of CONTAINER 1120 containing DATA objects 1121, 1122, and 1123. There is a HANDLE with FOCUS on object 1123; therefore, there is an entry 1101 in the FOCUS LIST for the CONTAINER 1120 of object 1123 and there is an entry 1102 in the FOCUS LIST for object 1123.
The FOCUS LIST is a dynamic list and changes as HANDLES move their FOCUS around the file and make changes in the file. The FOCUS LIST is a data structure in computer memory. Each open file in the present invention has an associated FOCUS LIST. In the example shown, the "parent" of each DATA object 1121, 1122, and 1123, is the CONTAINER 1120. Therefore, for example, whenever a HANDLE has FOCUS on DATA object 1123, represented by FOCUS ENTRY 1102 as shown in FIG. 11, there is an entry in the FOCUS LIST for CONTAINER 1120. This is illustrated in FIG. 11 by FOCUS ENTRY 1102 for the PREFIX of object 1123, and entry 1101 for CONTAINER 1120. The FOCUS LIST is sorted in logical order from least to greatest as defined above in this section and in the previous section. The entry for the parent CONTAINER 1120 is thus higher than the entry for the contained object 1123 in the FOCUS LIST of FIG. 11.
When a HANDLE is navigating, it uses the FOCUS LIST to move among objects in their logical order. For example, consider the case illustrated in FIG. 12 when HANDLE h1 is to ascend from FOCUS on the object 1123, represented by FOCUS ENTRY 1102, as shown in FIG. 11. HANDLE h1 first examines the FOCUS LIST to access the parent to determine if the ascension is within the boundaries of the file. In this case, the ascent from object 1123 to CONTAINER 1120, is within the boundaries of the file, so HANDLE h1 moves its reference to FOCUS ENTRY 1101, representing object 1120. If it is desired to continue to ascend, the HANDLE again examines the FOCUS LIST to determine if the ascent is within the file boundaries. In this case, continued ascent is in fact outside the boundaries of the file so the navigation move does not proceed.
When NAVIGATING to a logical position, the HANDLE first scans the FOCUS LIST to determine if a FOCUS ENTRY already exists for the destination. If so, the HANDLE obtains a reference to that FOCUS ENTRY and the NAVIGATION is accomplished. This requires no file I/O for NAVIGATION purposes. If, however, the logical position is occupied by an object in the file which is not currently represented by a FOCUS ENTRY, then a FOCUS ENTRY is created from the object in the file so that the HANDLE can obtain a reference to it.
The FOCUS ENTRIES track the number of HANDLES that are focusing on an object at one time, in order to prevent contention problems. When two or more HANDLES have FOCUS on an object, no ALTERATIONs to that object are permitted (but `append` and `insert` in reference to that object are allowed). The system of the present invention thus prevents simultaneous object ALTERATION by separate HANDLEs without requiring a specific object locking or range locking action.
The FOCUS ENTRIES on the FOCUS LIST provide the mechanism for HANDLE NAVIGATION and object manipulation, but they largely depend for their information content upon the structure and information content of the MFILE objects which they reference. The integration of these object structures with the memory-based object control mechanism is an essential part of the present invention.
The algorithms for NAVIGATION are described as follows:
DESCEND (allowed only into CONTAINER objects)
If desired FOCUS is in FOCUS LIST
Return it
Else
Find object after current FOCUS PREFIX and before current object SUFFIX, skipping removed objects
If there is no object contained within the current focus, go to a `null` FOCUS
Return the FOCUS
ASCEND (to a higher-level CONTAINER object)
Dispose of current FOCUS if no longer needed
Return enclosing FOCUS (retained in HANDLE stack)
NEXT
If desired FOCUS is in FOCUS LIST
Return the new FOCUS
Else
Find the object after the current FOCUS SUFFIX and within the enclosing CONTAINER, skipping removed objects
If the object is not represented yet on the FOCUS LIST, look into the physical file for the object and build a FOCUS ENTRY for it
If the desired object does not exist, return an error and retain the original FOCUS
If the old FOCUS is no longer needed, dispose of it
PRIOR
If desired FOCUS is in FOCUS LIST
Return the new FOCUS
Else
Find the object before the current FOCUS PREFIX and within the enclosing CONTAINER, skipping removed objects
If the object is not represented yet on the FOCUS LIST, look into the physical file for the object and build a FOCUS ENTRY for it
If the desired object does not exist, return an error and retain the original FOCUS
If the old FOCUS is no longer needed, dispose of it
T. Reconstitution.
The RECONSTITUTION procedure realigns the physical file with the logical file. When changes are made to an MFILE, representation of the changes in the form of SYSTEM objects arid associated new DATA and/or CONTAINER objects are added to the end of the file. All objects added to the end of the file constitute the TAIL of the MFILE.
RECONSTITUTION is invoked when the last HANDLE opened on an MFILE is closed. It is also invoked when certain conditions are met: these are conditions chosen to optimize performance of implementations of the present invention. These conditions generally fall into the the following categories:
1. The TAIL gets too long.
2. The TAIL has too many objects in it.
3. Too much time has passed since the last RECONSTITUTION.
4. The ratio of TAIL size to HEAD size becomes too great.
5. The FOCUS LIST occupies too much memory.
6. NAVIGATION using the FOCUS LIST takes too long.
RECONSTITUTION uses information in the FOCUS LIST to identify changes in the MFILE and to copy the changes in logical order to a new reconstituted MFILE, thereby aligning the physical condition of the MFILE to its logical condition. Although change information is also found in the SYSTEM objects, SYSTEM objects are not read during normal operation of the invention. This is because changes represented in the SYSTEM objects are also found in the FOCUS LIST.
The result of RECONSTITUTION is a new file HEAD object with no file TAIL, unless a separate thread was available for ongoing ALTERATIONS. The RECONSTITUTED MFILE is substituted for the old MFILE and the new file is given old file name. By the end of the RECONSTITUTION, each FOCUS ENTRY either has been updated to reflect the new physical object positions in the RECONSTITUTED file or it has been removed from the FOCUS LIST because it is no longer needed.
If separate threads of execution are available during RECONSTITUTION, the MFILE can continue to be altered if the alterations occurring during the RECONSTITUTION take place on a separate thread of execution. In this case, only changes to the MFILE completed prior to the start of the RECONSTITUTION process are reconstituted, and the new changes made during RECONSTITUTION are added as a TAIL to the RECONSTITUTED MFILE.
In the present description, the following definitions apply: MFile=The file that is being reconstituted. FList=The focus list being used prior to and external to the RECONSTITUTION. MF2=The file that is the result of RECONSTITUTION. FL2=The temporary focus list created for use during the RECONSTITUTION process. F, FGRP=Represent focus list entries.
FIGS. 6A and 6B are a flow diagram illustrating the RECONSTITUTION process. At step 601, alterations to MFile and FList are halted. That is, the state of a file as of a certain point is selected for the RECONSTITUTION process. Any subsequent alterations are not part of the RECONSTITUTION process. At step 602, FL2 is created by copying only those entries in FList that are necessary for RECONSTITUTION. (Step 602 is described in detail in the flow diagram of FIG. 7).
At step 603, the end of the tail of MFile is recorded, identifying the last alteration that is to be part of the RECONSTITUTION process. At step 604, alterations to MFile and FList are resumed. These alterations are not part of the current RECONSTITUTION process but rather are reconstituted in the next RECONSTITUTION process (if they are completed at that time). At step 605, MF2 is opened.
At step 606, groups from MFile are copied to MF2 in reconstituted form, using FL2 to identify changes that need to be made. This step is illustrated in detail in the flow diagram of FIG. 8. At step 607, alterations to MFile and FList are again halted, as at step 601. At step 608, any additional tail from MFile is copied to MF2, and FL2 is modified to reflect these alterations. At step 609, FList and FL2 are merged. This step removes any entries in FList that are no longer needed and updates all entries in FList that are needed. This step is illustrated in detail in the flow diagram of FIGS. 9A and 9B. At step 610, FL2 is deleted. At step 611, MFile is replaced with MF2 (the reconstituted file). A copy of MFile is retained for backup if desired. At step 612, alterations to MFile and Flist are resumed. The process ends at step 613.
FIG. 7 is a flow chart illustrating a method of creating FL2 by copying only necessary entries of FList(step 602 of FIG. 6A). At step 701 the head of the focus list is obtained (F). At step 702, FL2 is set equal to the new focus list, (consisting of a new copy of F). At step 703, F is set equal to the next Flist entry. At decision block 704, the argument "does F exist?" is made. If the argument is false (no more focus list entries), the system proceeds to step 705 and goes to the next step 603 in the flow diagram of FIG. 6A. If the argument at decision block 704 is true, the system proceeds to decision block 706.
At decision block 706 the arguments "F on tail?" or "F removed?" or "F's DATA changed?" are made. If any of the arguments are true, the FOCUS ENTRY is needed for RECONSTITUTION and so the system proceeds to step 707 and adds a copy of F (the current focus list entry) to FL2 and then returns to step 703. If all of the arguments at decision block 706 are false, the system returns to step 703. This occurs when the current focus list entry is not one that requires updating of the file. Therefore, it is skipped so that only needed focus list entries are obtained.
FIG. 8 illustrates the process of recursively copying groups from Mfile to MF2 in reconstituted form (step 606 of FIG. 6A), using FL2 to indicate which changes need to be made. The algorithm begins at step 801, with the highest level CONTAINER (the HEAD of FL2) via a function call like TransferGroup(Head -- of -- F2). At step 802 a new PREFIX is written for FGRP. At step 803, F is set equal to FGRP. The new PREFIX encodes the reconstituted size of the object, using the old data length and the data length change information which is maintained in the FOCUS ENTRY. At step 804 F is set equal to the next FL2 entry after F.
At decision block 805 the argument "Does F exist? and Is F in FGRP?" is made. If the argument is false, the system proceeds stops 806-808. At step 806 objects are transferred from the current position up to SUFFIX of FGRP in MFile. At step 807, a new SUFFIX for FGRP is written. F is returned at step 808. If the argument at decision block 805 is true, the system proceeds to step 809. At step 809 a transfer of objects up to F occurs. At decision block 811 the argument "Is F removed?" is made. If the argument is true, F is skipped, not copied to the new file at step 812. If the argument is false, the system proceeds to step 810.
At step 810, the argument "Is F a group?" is made. If the argument is false, F is copied to the new file at step 813. If the argument at decision block 810 is true, the system proceeds to step 814, and F is set equal to the return of the function call TransferGroup(F), which causes a recursive invocation of the algorithm. The system then returns to step 804 from steps 812, 813 and 814.
FIGS. 9A and 9B illustrate a method of merging FList and FL2 (step 609 of FIG. 6B). The steps remove any entries in FList that are no longer needed and update all entries in FList that are needed. At step 901, F is set equal to head of FList. At decision block 902 the arguments "F currently used?" or "F currently needed?" or "F pending removal?" or "F pending replacement" or "F on tail of MFILE but not reconstituted in MF2?" are made. If any of the arguments are true, the system proceeds to step 903 and F is updated with FL2 and MF2. If all the arguments at decision block 902 are false, the system proceeds to step 904 and F is removed from FList.
After steps 903 or 904, the system proceeds to step 905 and F is set equal to next FList entry. At derision block 906 the argument "Does F exist?" is made. If the argument is true, the system returns to decision block 902. If the argument at decision block 906 is false, the system proceeds to step 907. At step 907, F is set equal to head of FL2. At decision block 908, the argument "Has F been removed since RECONSTITUTION began?" is made. If the argument is true, the system proceeds to step 909. If the argument is false, the system proceeds to step 910.
At step 909, F is added to FList. At step 910, F is set equal to next FL2 entry. At decision block 911, the argument "Does F exist?" is made. If the argument is true, the system returns to decision block 908. If the argument at decision block 911 is false, the system proceeds to step 912 and goes to the next step (610).
U. Recovery.
Under normal operating circumstances, the SYSTEM objects on the TAIL of an MFILE are not used for any purpose. The reason for this is that all necessary information relating to logical file structure is retained in the FOCUS LIST. In the event of unexpected interruption of the computer process that employs the present invention, however, the SYSTEM objects are used to reconstruct the FOCUS LIST when the process resumes. The same circumstance applies when an MFILE must be reconstructed from its JOURNAL. Note that in all cases except the REMOVE action, the SYSTEM object is followed in the TAIL by the object or objects that are to be added.
To RECOVER the FOCUS LIST from the TALL, each SYSTEM object is processed sequentially. If a SYSTEM object represents an INSERT, REMOVE or APPEND action, a FOCUS ENTRY is created for each enclosing CONTAINER which is not already on the FOCUS LIST. Then a FOCUS ENTRY is added to the FOCUS LIST for each added and each REMOVED object. If a SYSTEM object represents a REPLACE action, it is treated as an INSERT action followed by a REMOVE action. If an error in TAIL structure or object structure is detected, the affected object and the rest of the TAIL are ignored, causing a virtual truncation of the TAIL. Recovery of the rest of the TAIL is not done because the TAIL is built sequentially and the information contained in SYSTEM objects is dependent upon all prior alterations. (It would be possible to keep a disordered TAIL with sequence numbers in the SYSTEM objects). Any corrupted object completely invalidates whatever alterations are recorded after that object.
Errors that might occur in a TAIL or object structure include object structure corruption, incomplete TRANSACTIONs, and unrecognized objects. In the case of an incomplete TRANSACTION, the TAIL is effectively truncated just before the START of the TRANSACTION.
V. Journal.
Every MFILE is matched by a JOURNAL, at the option of the programmer. The invention comprehends the possibility of merging the JOURNALS for multiple MFILES that are associated with one another. The content of a JOURNAL for a given MFILE is the content of a TAIL of the MFILE just before RECONSTITUTION begins. At each occurrence of RECONSTITUTION, the matching JOURNAL is augmented by appending the TAIL removed from the MFILE. The invention also comprehends the augmentation of the JOURNAL every time that an object is added to the TAIL of the MFILE, which is a procedure that involves more processing overhead but produces a JOURNAL which is always up-to-date. The JOURNAL itself is never RECONSTITUTED. In order to allow rebuilding of a file from the JOURNAL, there must exist an earlier copy of the principal MFILE that coincides with a starting-point in the JOURNAL. The invention comprehends the possibility of including this base copy of the MFILE in the JOURNAL itself. JOURNAL entries are augmented by date-time stamps to facilitate the matching to dated copies of the principal MFILE.
A lost or corrupted MFILE can be reconstructed from its JOURNAL, provided that the JOURNAL includes all alterations since creation of the MFILE or that the JOURNAL supplements a backup copy of an earlier version of the MFILE. The procedure used is RECONSTITUTION, but--unlike normal RECONSTITUTION--the JOURNAL is not erased at the conclusion of the procedure.
An MFILE can also be restored to an earlier state by roll-backward reversal of JOURNAL entries. The reversals themselves are new alterations that are appended to the JOURNAL. A damaged file can be reconstructed from a backup copy plus subsequent changes ("deltas"). Inversely, a current file can be cycled through multiple "undo" actions to reverse the effect of alterations.
W. Transactions.
A TRANSACTION is a procedural grouping of alterations to a file that serves the purpose of assuring that all of the changes permanently affect the file if any affect the file. Transactions assure atomic completion of a set of file alterations. A TRANSACTION is started by a START TRANSACTION action and ended by a COMMIT or ABANDON action: in the case of a COMMIT, all of the alterations are made permanent by adding them to the UPDATES QUEUE bounded by BEGIN TRANSACTION and END TRANSACTION markers.
The RECOVERY and RECONSTITUTION processes will not begin during the processing of a TRANSACTION and RECOVERY will abort and restart in order to avoid adding to the FOCUS LIST or HEAD of an MFILE any parts of a TRANSACTION if the TAIL of the file contains only a BEGIN without a matching END or an END without a matching BEGIN. In the case of an ABANDON, none of the alterations within the TRANSACTION occurs, and the alterations are discarded.
There are two categories of transactions in the present invention, "fixed" and "wandering". These transactions are similar in concept, but differ in their implementations and in resultant behavior. Both transactions can be described as a set of file alterations that can be abandoned or committed as a group. The categories are differentiated by the fact that navigation among objects that are to be added is possible in a "fixed" transaction, but not in a "wandering" transaction.
A fixed TRANSACTION is implemented by creation of a temporary file and temporary handle. During a fixed TRANSACTION, the HANDLE is given focus on the temporary file and NAVIGATION is limited to the contents of the temporary file. When the fixed TRANSACTION is COMMITted, the ALTERATION occurs in the permanent file at one location only--the location specified by the ALTERATION which initiated the TRANSACTION. The ALTERATION is accomplished by plating a reference to the temporary file on the UPDATES QUEUE of the permanent file in the following order: a BEGIN TRANSACTION marker, a reference to the temporary file, and an END TRANSACTION marker. The TRANSACTION is then processed normally from the UPDATES QUEUE to the TAIL of the permanent MFILE.
Once a fixed TRANSACTION command has been issued by a handle, one nested wandering TRANSACTION can begin (but no fixed TRANSACTION). No TRANSACTIONS can be nested inside a wandering TRANSACTION.
A wandering TRANSACTION is implemented by creation of a temporary UPDATES QUEUE. When the TRANSACTION is COMMITTED, the temporary UPDATES QUEUE is appended to the permanent UPDATES QUEUE. NAVIGATION on the permanent file will not reveal the pending alterations already entered during the unCOMMITted wandering TRANSACTION.
While a wandering TRANSACTION is pending, each FOCUS relative to which an alteration is made is locked. Since multiple handles may have parallel TRANSACTIONS pending, the locks are implemented with a "needed" count. If the TRANSACTION is ABANDONed, the locks are decremented as a group; if the TRANSACTION is COMMITted, the lock is decremented as each update is made.
When a TRANSACTION is COMMITted, SYSTEM objects for BEGIN TRANSACTION and END TRANSACTION must be created and added to the tall of a file so that upon RECONSTITUTION it is possible to require inclusion of an entire TRANSACTION as a condition of inclusion of any part of it. Thus, RECONSTITUTION is prevented between the times that BEGIN TRANSACTION has been processed from the ALTERATIONS QUEUE and the time that the matching END TRANSACTION is processed.
X. File Corruption.
The file system of the present invention provides a number of methods for error detection. For example, the PREFIX and SUFFIX must match for each set of BRACKETs: at the programmer's option, a simple comparison is used as a threshold integrity check. In addition, the PREFIX and SUFFIX must effectively point to each other. When they do not point to each other, an error is detected. Also, each BRACKET includes a parity bit which is checked for consistency with the bit pattern of the BRACKET.
The present invention provides a method for detecting, locating, and marking bad DATA objects in a file. Consider the case where there are ten DATA objects within a CONTAINER and DATA objects five, six, and seven are corrupted. Suppose also that a HANDLE has FOCUS on object four. When a move is attempted from object four to object five, the parity checks are returned as `invalid`, indicating a problem. That error triggers an error recovery routine to map out the bad DATA objects. The routine assumes that it would not have been possible to move into the CONTAINER containing the bad DATA objects if the CONTAINER BRACKETs didn't match properly. At the level of the CONTAINER, the structure of the file has integrity. The routine begins with focus at the PREFIX of the CONTAINER and navigates into the CONTAINER from the PREFIX, keeping track of the location of the first object that fails the validation check (e.g., DATA object five). Next, the routine returns to the CONTAINER level and navigates backwards from the SUFFIX of the CONTAINER, keeping track of the location of the first object in that navigation direction that fails the validation check (e.g. DATA object seven). Now the beginning and end of the bad area have been defined. A focus list entry is then constructed to describe that range and to keep track of it in memory. After that, no handle can move into the bad area or read it.
As part of the error recovery routine, a copy of the bad area can be written out to a separate file. If the file is closed, the temporary FOCUS ENTRY record of the extent of the bad area is lost. If the file is reopened, there is no history or awareness on the FOCUS LIST of the bad area and there will not be any until there is another attempt to navigate into the bad area. At that point, the error routine is triggered and the bad area is discovered and marked again. The present invention does provide for extension to add a SYSTEM object to the TAIL of the MFILE denoting the bad area.
Every error block begins where (and includes) the PREFIX keybyte of some object would be (as viewed from an intact preceding object or from the PREFIX of an intact containing object) and ends where (and includes) the SUFFIX keybyte of some object at the same level would be (as viewed from an intact succeeding object or from the SUFFIX of an intact containing object); thus, when the error block is removed from the file the remaining adjacent and containing objects remain intact.
For error DATA blocks, it is possible to identify when DATA has been added or deleted by referring to the expected DATA length in the PREFIX and SUFFIX. The present invention optionally uses checksums for detection of errors in enclosed DATA or enclosed objects. The checksum is calculated and recorded in the object whenever the object is altered. If an error is detected based on the checksum, the same procedure as for a BRACKETS error above is performed.
Y. Embodiments of the Invention.
The present invention is embodied as computer code. In its operational condition, this computer code is `object` code or `executable` code which has been compiled from `source` code into a form that can be executed on a particular computer platform.
The invention provides predefined file structuring and file access services to other programs. The means by which this access may be obtained can vary in at least the following ways:
1. The invention may be provided as a library of source code, which may be compiled and linked into executable programs on a given computer platform. The using programmer in this instance determines whether the invention will be used by one or many programs.
2. The invention may be provided as a library of compiled object code, which may be compiled and statically linked into executable programs on a given computer platform. In this form the library must be prepared in advance to match the computer and compiler (and possibly also the linker) in use. The using programmer in this instance determines whether the invention will be used by one or many programs.
3. The invention may be provided as a dynamically-linkable library of compiled object code, which may be dynamically linked by as many employing programs as may be operating at a given moment on a given computer platform. In this form the library must be prepared in advance to match the computer and possibly the compiler and the linker in use.
4. The invention may be provided as an independent process to which service requests may be submitted by inter-process communications on a given computer or across a network-type connection between different computers. In this case, the invention will return information to the requesting process to indicate the result of the requested service.
5. The invention may be provided as a device driver which controls all access to a volume of a persistent storage device, such as a magnetic disk or CD-ROM. In this form the operating system of the computer in use must mediate the service calls by processes that can use that computer, and the implementation of the invention must be compiled and linked as an executable device driver suitable for that computer.
Z. Computer System
The present invention can be implemented on a general purpose computer such as illustrated in FIG. 1. A keyboard 110 and mouse 111 are coupled to a bi-directional system bus 118. The keyboard and mouse are for introducing user input to the computer system and communicating that user input to CPU 113. The computer system of FIG. 1 also includes a video memory 114, main memory 115 and mass storage 112, all coupled to bi-directional system bus 118 along with keyboard 110, mouse 111 and CPU 113. The mass storage 112 may include both fixed and removable media, such as magnetic, optical or magnetic optical storage systems or any other available mass storage technology. Bus 118 may contain, for example, 32 address lines for addressing video memory 114 or main memory 115. The system bus 118 also includes, for example, a 32-bit DATA bus for transferring DATA between and among the components, such as CPU 113, main memory 115, video memory 114 and mass storage 112. Alternatively, multiplex DATA/address lines may be used instead of separate DATA and address lines.
In the preferred embodiment of this invention, the CPU 113 is a 32-bit microprocessor manufactured by Intel, such as the 80386, 80486, or Pentium, executing the OS/2 operating system of International Business Machines of Armonk, N.Y. However, any other suitable microprocessor or microcomputer may be utilized. Main memory 115 is comprised of dynamic random access memory (DRAM). Video memory 114 is a dual-ported video random access memory. One port of the video memory 114 is coupled to video amplifier 116. The video amplifier 116 is used to drive the cathode ray tube (CRT) raster monitor 117. Video amplifier 116 is well known in the art and may be implemented by any suitable means. This circuitry converts pixel DATA stored in video memory 114 to a raster signal suitable for use by monitor 117. Monitor 117 is a type of monitor suitable for displaying graphic images, and in the preferred embodiment of this invention, has a resolution of approximately 1024×768. Other resolution monitors may be utilized in this invention.
The computer system described above is for purposes of example only. The present invention may be implemented in any type of computer system or programming or processing environment. Thus, a method and apparatus for implementing a file structuring system has been described.
The present invention uses the facilities of the computer hardware to accomplish its operations. For example, the present invention builds its internal control structures, such as FOCUS ENTRY, FOCUS LIST and HANDLE, in main memory 115; it stores objects from main memory 115 to mass storage 112 and retrieves objects from mass storage 112 to main memory 115; and it receives data and commands from computer programs that employ the present invention and which necessarily obtain data and commands through the same above-described computer hardware.
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The present invention provides an object-oriented file structuring system. The invention provides a method of defining DATA objects and CONTAINER objects and SYSTEM objects that facilitates navigation through a file structuring system. Notation and nomenclature are defined for building files composed of CONTAINERs and DATA and SYSTEM objects and for defining relationships between and among files, CONTAINERs and DATA. A FOCUS LIST tracks objects of interest and aids in NAVIGATION. CONTAINER objects contain other objects. DATA objects enclose DATA in either machine-dependent or machine-independent value representations. Developers work with logical files and can freely create and modify the logical relationships of file objects. A RECONSTITUTION algorithm periodically updates the physical file to correspond to the logical file.
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BACKGROUND
1. Technical Field
The present disclosure relates to cross-point nanoarrays which can be used as non-volatile memory structures or as sensors able to be produced using non-conventional lithographic techniques including so-called “soft-lithography”.
2. Description of the Related Art
As is known, non-volatile memories, i.e., memories which are able to retain the stored data even in the absence of a power supply, are today widespread in many areas of electronics. These devices, at present, are formed on silicon substrates using highly advanced technology which is well-established in particular form the point of view of the reliability and compactness achieved: today the technological challenge is to produce memories using a technology with definition lines having a width of 65 nm and even finer.
The cell structure generally has as a memory element a floating gate which is arranged underneath a control gate electrode; operation of the device is associated specifically to the combined biasing of the two gates which are separated by dielectric and arranged over a channel region in the semiconductor between source and drain. The data to be stored physically consists of the electric charge that is accumulated in the floating gate.
The rapid growth of the memory market is providing an impetus for the development of alternative non-volatile memory structures which are potentially able to overcome the technological limits of scalability of silicon structures at an acceptable cost and improve the performance in terms of read/write speed, data retention time, and reduction of the voltages employed during reading and writing [1].
At present various alternative structures which can be used as a non-volatile memory are being studied, as schematically shown in FIG. 1 .
Among the structures studies, the most promising, in terms of integrative possibilities, are organic memories which use polymer materials as the active material and in particular wholly organic memories (i.e., memories which can be produced exclusively with organic materials) and hybrid memories (i.e., memories which can be produced using conventional materials, for example ordinary conductive materials in combination with organic materials).
These memory cells may be made with particularly simple structures (so-called cross-point array structures), as schematically shown in the diagram of FIG. 2 , and in some cases arranged in vertical stacks, as schematically shown in FIG. 3 , being thus possible to multiply the memory density per unit of footprint area. Moreover, organic memories are the only memories which are in theory capable of allowing scaling down to molecular dimensions and therefore potentially achieving an extraordinary degree of compactness.
In these memory structures, an active organic material is arranged between two electrodes made of a conductive material which can be defined in the form of parallel nanorows in a simple cross-point matrix arrangement.
In the area of organic memories there exist two different types of operation, i.e., based on ferroelectric behavior and resistive switching operation, which are illustrated in FIGS. 2 and 3 , respectively.
Of these two different types, the most advantageous in terms of compactness are resistive switching memories since, in the case of ferroelectric memories, an auxiliary transistor is associated to each cell to avoid data loss during reading.
Therefore, cross-point nanoarrays, such as those shown in FIGS. 2 and 3 , which are based on modification of the electric resistance through the layer of active organic material that separates the electrodes of the two separate orthogonal orders of electrodes, at the cross-over points, may be useful not only as a non-volatile memory structure, but even as a sensing structure, for example able to detect pressure patterns over a relatively large area, for producing user interfaces, for example in the form of keyboards and for similar uses.
Dual-Electrode Polymer Devices
A two-electrode device may be simply produced by means of a sandwich structure comprising a bottom electrode (consisting of Al, Ag, Cu, Ni, doped polysilicon, etc.), a layer of active polymer material deposited for example by means of spin-coating, and a top electrode (consisting of Al, Ag, Cu, Ni, doped polysilicon, etc.) formed for example by CVD (Chemical Vapor Deposition).
A device of this type may function as a memory element for example by applying an electric field across the active organic material at a cross-over point (cell), able to induce formation of conductive paths in the active polymer material or activate a charge transfer or other detectable modification which can be detected in the organic material. Below few examples of polymer materials, their structures, characteristics and the operating principles of devices using them as active materials are given.
Polystyrene
The behavior of atactic polystyrene film between two metal (Al, Au, etc.) electrodes as a non-volatile memory element was already studied in 1976 by Carchano and colleagues [2]. The I-V characteristics demonstrate a transition from a high-resistance state (108 Ohms) to a low-resistance state (10 Ohms) and the reverse transition after the application of a suitable difference in potential. According to the authors, the switching transition between the two states was due to the formation of conductive strands consisting of carbon atoms (C═C) in the polymer between the electrodes.
The most recent research into conductive polymers relate to polystyrene film containing metallic nanoclusters.
Yang Yang et al. [3][4][5] have studied the operation of devices obtained by depositing an organic film between two Al electrodes, as shown in FIG. 4 .
The organic film is formed by depositing by means of spin-coating a solution of Au nanoparticles passivated with 1-dodecanthiol (Au-DT NPs, diameter 1.6-4.4 nm), 8-hydroxyquinoline (8HQ) and polystyrene in 1,2-dichlorobenzene [3]. FIG. 5 show the chemical structures of the materials used.
The bottom electrode and top electrode are thermally deposited from vapor phase, while the active layer is deposited from a solution of 0.4% wt % Au-DT NPs, 0.4 wt % 8HQ and 1.2 wt % polystyrene in 1,2-dichlorobenzene. Upon application of an electric field, the device undergoes a transition between two conductive states and may be written, read and erased repeatedly as shown in FIG. 6 .
The presence of two different conductive states suggests a change in the distribution of the electrons of the device owing to the action of the electric field. The 8HQ molecules and Au nanoparticles behave as electron donors and electron acceptors, respectively, such that the electric field activates a charge transfer between Au-DT NP and 8HQ. Prior to the transition, there is no interaction between the two domains, but when an electric field is applied to the device, an electron of the highest occupied molecular orbital (HOMO) of the 8HQ is able to pass through the dodecanthiol passivation layer to the Au nanoparticle, as schematically illustrated in FIG. 7 .
The most interesting characteristics of this mechanism are the stability of the two states, the fast switching response, the high ON/OFF ratio (105) and the ample opportunity to vary the materials owing to the simplicity of the manufacturing processes. The effect of various materials on the performance of the devices, substituting 8HQ with another conjugated organic compound, 9,10-demethylanthracene, and the aPS with polymethyl methacrylate PMMA was also studied. The resultant devices had an electrical behavior substantially similar to that described above.
The use of different conductive materials, such Au, Cu and ITO, instead of Al, for the electrodes also did not have a decisive effect on the performance of the device.
A WORM (write-once-read-many-times-memory) memory device, consisting of a polystyrene film containing Au nanoparticles passivated with 2-naphthalenethiol (AU-2NT NPs), the structure of which is shown in FIG. 8 , was also produced and inserted between Al electrodes [4].
From an analysis of the I-V characteristic of this device shown in FIG. 3 it can be seen that, owing to the effect of the electric field, the device passes from a low conductivity state, where the current which flows through the device depends on the injection of charge from the electrode to the polymer material and is limited by the barrier present at the metal-polymer interface, to a higher conductivity state, where the current is associated with the formation of an excess charge in the organic layer situated between the two electrodes (space-charge-limited current region). The increase in the current between the two states, measured at about 2V, is greater than three orders of magnitude. Upon reversing the polarity of the electric field there was no transition to the “0” state, but instead a significant increase in the absolute value of the current, thereby confirming the existence of a space-charge-limited current regime.
This transition between the two conduction states was reasonably attributed to the activation of a charge transfer by the electric field between the Au nanoparticles and the 2-NT film which passivates them as schematically shown in FIG. 10 . In view of the stability of the device in the higher conductivity state, it may be used as a WORM memory.
Polymethyl Methacrylate
The behavior of polymethyl methacrylate, polyethyl methacrylate and polybutyl methacrylate film between two metal electrodes (Al, Au, etc.) for use in non-volatile memory devices was already studied in 1974 [6]. FIG. 11 shows the result obtained on a film with a thickness of about 0.5 μm deposited between two metal electrodes from a solution containing 5% PMMA from butanone or benzene. As in the case of atactic polystyrene, the authors suggest that switching is induced by the formation in the polymer of conductive strands of carbon atoms (C═C) between the electrodes.
The most recent research into the derivatives of methyl methacrylate relate to the use of polymethyl methacrylate film as a material for the matrix containing metal nanoparticles or derivatives of polymethacrylate functionalized with pendant chromophores such as anthracene, poly(methylmethacrylate-co-9-anthracenyl-methylmethacrylate) (10:1), MDCPAC. The use of these polymers allows the excellent mechanical properties of polymethacrylate to be combined with the interesting electronic characteristics of anthracene.
The device is formed by means of vapor phase deposition of the bottom Au electrode on a glass substrate, followed by deposition of the active MDCPAC layer by means of spin-coating from a solution of chloroform (20 mg/mL in ClCH3) and finally vapor phase deposition of the second Al electrode.
The I-V characteristic of such a device is shown in FIG. 12 a and FIG. 12 b The first graph ( FIG. 12 a ) shows the characteristic of a circuit consisting of the memory device in series with a 107Ω resistance, from where it can be seen that when V=Vcrit the device switches between two states (OFF and ON).
When V<Vcrit the current in the circuit is essentially controlled by the device which has a resistance greater than 107Ω, corresponding to an OFF state. When V>Vcrit, the current in the circuit is controlled essentially by the resistor in series with the device, which is therefore in a lower resistivity state (ON). If the voltage applied is reduced the device remains in the ON state until V=Vhold, which is the erase voltage.
BRIEF SUMMARY
The impossibility or rather the technological limits which in practice make it difficult to pattern the active organic film by an appropriate etch or ablation technique such to leave it solely in coincidence with the projected cross-over areas of electrodes belonging to the two orthogonal orders of spaced parallel electrodes (single cell areas), gives rise to considerable cross-talk between adjacent cells (cross-over points) in the array.
The phenomenon of cross-talk due to the impossibility/technological difficulty of being able to provide for the presence of an electrically active film of organic material solely in the cross-over areas (cells), in addition to being a major obstacle to achieving cross-point nanoarrays with the technological minimum definition width of the conductive nanowires (spaced parallel electrodes), nowadays of about 40-60 nanometers, often may results in the need for specific read and write algorithms capable of resolving intelligibility uncertainties caused by the cross-talk phenomenon.
One embodiment is an improved cross-point nanoarray without cross-talk or at least with a much smaller amount of residual cross-talk between adjacent cells.
One embodiment is a cross-point nanoarrays with a greater degree of compactness compared to that which has been possible hitherto, and with improved cross-talk characteristic.
Another object of the present disclosure is to provide an improved process for manufacturing a cross-point nanoarray.
One embodiment is a cross-point memory having an active organic layer that is not isotropic but has a marked anisotropy.
The active organic layer separating the two orders of mutually orthogonal electrodes contains nanostructures or polymer domains that are oriented in a direction orthogonal to the plane of the active organic separation layer and which extend through the thickness of the organic layer between the opposite surfaces of the electrodes in the cross-over zones.
These nanostructures or polymer domains are formed spontaneously in the organic matrix layer consisting of a mixture of materials, one of the key components of which is a block copolymer, able to produce nanostructures ordered on a large scale through a phase separation mechanism due to incompatibility among polymer blocks and through a self-assembly mechanism (i.e., the ability of spontaneously organizing/reordering themselves), coupled to the capacity of these ordered domains to sequester nanoparticles of conductive material and/or clusters of nanoparticles (originally dispersed homogeneously in the resin mix), subtracting them from the surrounding matrix resin of the layer.
Polymer nanostructures or domains, ordered in a substantially large-scale and preferably also having a prevalent common orientation in a transverse direction relative to the plane of the layer, that have the characteristic of becoming enriched of conductive nanoparticles and/or nanoclusters thereof, create innumerable current paths across the thickness of the active organic layer from one electrode to the other electrode opposite thereto, at any cross-point, the local conductivity (resistance) of which may be significantly modified by biasing the purposely selected opposite electrodes of the two orders.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates the various areas of research being conducted at present and the problems to be solved in order to progress from conventional non-volatile memories to memories with a novel design.
FIG. 2 illustrates the structural simplicity of a cross-point array.
FIG. 3 illustrates the easy stacking capability of the cross-point arrays.
FIG. 4 shows the basic structure of a cross-point memory device using an organic film containing gold nanoparticles.
FIG. 5 shows the chemical structures of a) polystyrene, b) 8-hydroxyquinoline and c) 1-dodecanthiol.
FIG. 6 shows read-write-erase cycles of an Al/Au-DT+8HQ+PS/Al device.
FIG. 7 shows the mechanism for transferring the electrons from the 8HQ to the Au nanoparticles.
FIG. 8 shows the chemical structure of 2-naphthalenethiol.
FIG. 9 shows the I-V characteristic of Al/Au-2NT NPs+PS/Al for positive voltage values and, in the inset, the curve for negative voltage values.
FIG. 10 shows the diagram for transfer of the electrons from the 2-NT to the Au nanoparticles.
FIG. 11 is a schematic representation of a switching process in a PMMA device.
FIG. 12 shows in section a) the I-V characteristic of an Au/MDCPAC/Al device in series with a 107Ω resistance, and in section b) the calculated I-V characteristic of the device.
FIG. 13 is a diagram illustrating self-assembly in block copolymers.
FIG. 14 shows the different microstructures which are generated by means of self-assembly in AB diblock copolymers (a) and in ABC triblock copolymers (b), depending on the volume fraction of the minor component.
FIGS. 15 and 16 are TEM bright-field images of thin films of a triblock copolymer polystyrene-b-polyisoprene-b-polymethylmethacrylate (a) and a star copolymer polystyrene-b-polyisoprene-b-polymethylmethacrylate (b), after staining with OsO 4 .
FIG. 17 is a bright-field TEM image of a thin film of a diblock copolymer polystyrene-poly(ethylene-co-propylene) in which passivated gold nanoparticles are included in the polystyrene layers alone.
FIG. 18 illustrates the manufacture of a PDMS stamp.
FIG. 19 illustrates the technique of microcontact printing a SAM of thiols on a gold substrate.
FIG. 20 illustrates the technique of microcontact printing using a cylindrical stamp.
FIG. 21 shows SEM images of Ag patterns (a-c: 50 nm; d: 200 nm thickness); Au (e: 20 nm thickness); Cu (f: 50 nm thickness) obtained by means of SAMs of hexadecanthiols. The patterns a) and b) were obtained using cylindrical stamps, while the patterns c) to f) were obtained with flat stamps.
FIG. 22 shows the formation of patterns of a polymer material (in black) by means of the microtransfer molding technique.
FIG. 23 shows the formation of patterns by means of MIMIC.
FIG. 24 is a SEM image of a PANI conductive strip.
FIG. 25 shows a photomask for defining a pattern of parallel strips
FIG. 26 illustrates the manufacture of the PDMS stamp.
FIG. 27 illustrates the manufacture of self-aligned bottom electrode strips by means of the microtransfer molding technique.
FIG. 28 illustrates the manufacture of self-aligned bottom electrode strips and active material film by means of the micromolding in capillaries technique.
FIG. 29 illustrates the manufacture of bottom electrode strips by means of a thiol layer deposited using the microcontact printing technique.
FIG. 30 shows a dual-electrode device with an active layer consisting of a block copolymer in which the cylinders contain passivated gold nanoparticles and an electron donor.
DETAILED DESCRIPTION
In order to explain better certain operating mechanisms, methods for producing nanoarrays and results and features of the novel devices according to the disclosure, it is considered useful to describe in general the block copolymers and their features and, by way of non-limiting examples, also some organic materials which can be used to produce cross-point nanoarrays according to the present disclosure.
Block Copolymers
Block copolymers are—generally amorphous—polymer materials in which the individual macromolecules consist of at least two different chemically bonded polymer chains (blocks). If the two polymer blocks are chemically incompatible, phase separation occurs, with spontaneous segregation of the different macromolecules into different microdomains as schematically shown in FIG. 13 .
This so-called “self-assembly” phenomenon results in the spontaneous formation of nanostructures [7]. A compromise between the tendency for phase separation and chemical connectivity may result in the formation of periodic structures in which both the periodicity and the size of the domains depend on the lengths of the blocks and therefore the molecular masses.
Different microstructures are obtained depending on the chemical nature of the blocks and the associated molecular masses. The fundamental variables which define the type of nanostructure which is formed by means of self-assembly are as follows: the Flory Huggins χ interaction parameter, which defines the degree of incompatibility of the blocks, and the volume fraction of the blocks φ, which depends on the relative length of the blocks [7].
FIG. 14 shows classic microstructures found for diblock copolymers (a) and triblock copolymers (b)[7][8].
In the case of diblock copolymers, the minor component of lower molecular weight segregates into spheres when its volume fraction is less than 20% and into cylinders when the volume fraction lies between 21 and 33%. Instead, alternating lamellae are obtained in the case of symmetrical block copolymers where the molecular masses of the two blocks are comparable. Finally, bicontinuous network structures (double gyroid and double diamond) are obtained within a limited formation range (volume fraction of 33-37%) [7][8]. In the case of triblock copolymers the combination of the different formation sequences ABC, ACB, BAC and overall molecular mass provides an enormous quantity of parameters, allowing the creation of numerous new morphologies, as shown in part b) of the figure.
A first characteristic of these systems, exploited in the practice of an embodiment of this disclosure, is that the microdomains spontaneously formed by means of equally spontaneous self-assembly tend to be packed in ordered structures which are reminiscent of crystalline material structures. For example, the spheres are packed in cube-like lattices with a centered body, and the cylinders in hexagonal lattices (FIG. 14 . a ). From this point of view, block copolymers constitute a class of amorphous materials in which the amorphism nevertheless has a structure similar to that of crystalline materials, with the major difference that the dimensions of the repeating units and the periodicity are not of the order of magnitude of angstroms (Å), as in crystals, but the dimensions of the microdomains into which the polymer blocks segregate (spheres, cylinders and lamellae) depend on the length of the blocks and, therefore, are of the order of magnitude of nanometers. Similarly, the periodicity of the microstructure depends on the molecular masses of the blocks. It is thus possible to regulate the size of the microdomains and the periodicity within fairly large ranges, from a few tens to several hundred of nanometers, by modifying the molecular masses of the blocks.
Typical living polymerization methods which are able to guarantee the formation of block copolymers are: living anionic, living cationic and controlled radical polymerization, polymerization catalysis by means of metathesis on metal-organic compounds. With these methods it is possible to obtain block copolymers with largely amorphous blocks and, even if crystalline, with a low melting point and poor mechanical properties.
Hitherto, the preparation of semi-crystalline block copolymers, which contain, for example, polyethylene blocks, has involved a somewhat elaborate and laborious synthetic process based on classic procedures involving living anionic polymerization, for example of butadiene, and subsequent selective hydrogenation of the polybutadiene.
However, recently novel catalytic systems have been described in literature on the subject, these being based on transition metal compounds, with bis(imino)phenoxide and aminophenoxide bonding agents, able to polymerize alpha-olefin monomers in a stereoselective manner and in particular able to produce block copolymers. Using these catalysts, copolymers containing crystallizable blocks of isotactic or syndiotactic polypropylene have been synthesized. This approach represents an extremely versatile method for synthesizing new molecular architectures and offers the possibility of access to a large number of different molecular topologies by varying co-monomers, molecular masses and stereoregularity of 1-olefin blocks. As a result it is possible to regulate and control the morphology and final structure of the block copolymers in a more efficient manner compared to the systems produced by means of anionic and/or radical polymerization and obtain greater control over the patterns which are to be formed.
The second characteristic of these systems that is exploited in the practice of an embodiment of this disclosure, consists in the possibility of using the ordered nanostructures formed by self-assembly as nanodomains (hosts) for the inclusion of guest molecules and an enhanced accumulation of conductive nanoparticles in the nanodomains. The different microdomains of the nanostructures generated by block copolymers (lamellae, spheres or cylinders) act as hosts for selectively sequestering nanofillers (guests) of suitable chemical and dimensional affinity.
The use, in a cross-point nanoarray, of an active organic film as separator between opposed electrodes belonging to the two orthogonal orders of electrodes, of a material comprising large-scale ordered nanostructures of block copolymer extending across the thickness of the organic film, instead of homopolymers, and in which polymeric blocks that form the nanostructures or domains have the ability of sequestering, because of enhanced chemical and physical affinity, conductive nanoparticles subtracting them from the surrounding organic matrix, provides a substantial predetermined anisotropy of the separation active organic film in terms of preferential electric current paths through the thickness of the active separator. This is extraordinarily effective in limiting the possibility that current flows, induced through the thickness of the organic film by localized biasing of the opposing electrodes at a certain cross-over point (array cell), may influence neighboring cross-point cells because of stray current paths extending laterally in the organic film, well beyond the perimeter of the projected cross over area of the two opposedly biased electrodes.
Moreover, conductive nanoparticles capable of inducing specific electric properties in the same organic material of the electrode separation film, since they are not randomly distributed in the organic matrix, but present largely in ordered nanodomains, increase the ability thereof to establish and control the final properties of the nanocompounds and ultimately the active organic film of the devices (cells).
FIG. 15 shows a TEM image of a nanocomposite based on a lamellar block copolymer in which gold nanoparticles are distributed in an ordered manner almost exclusively in specific domains of the organic material.
FIGS. 15 and 16 show, by way of example, TEM images of thin films of a copolymer polystyrene-b-polybutadiene-b-polystyrene and a star copolymer polystyrene-b-polyisoprene-b-polymethylmethacrylate. FIG. 15 shows cylinders of polybutadiene perpendicular to the surface of the film and packed in a hexagonal lattice within a polystyrene matrix, while FIG. 16 shows a pattern of rhombus-shaped polyisoprene microdomains packed in an orthorhombic lattice within a rigid matrix of polymethyl methacrylate.
One embodiment induces an effective orientation of the microdomains (e.g., “cylinders” parallel and perpendicular to the surface) and creates ordered structures on a nanometric scale, with an order which may extend to sufficiently large dimensions. This may be achieved by means of the application of an electric field, during phase separation in the organic mixture containing conductive nanoparticles dispersed within the organic mixture, during deposition and/or distribution thereof over the surface of electrodes predefined on the side of a substrate.
Various techniques for processing block copolymers able to obtain thin films (or research samples and bulk finishing) with ordered nanostructures comprise, for example, capillary extrusion, shearing, spin-coating, roll-casting, application of an electric field, application of a thermal gradient, directional solidification and interaction with electrode surfaces, making use in particular of topographic effects and epitaxial phenomena.
With the conventional methods for preparing block copolymers, based on the classic procedures of living anionic polymerization, it is difficult to obtain crystalline materials.
The presence of crystallinity is instead desirable because it enables, to a certain degree, control over the type of nanostructure to be obtained by means of phase separation, via crystallization control, using innovative technologies based on directional solidification from crystallizable solvents and epitaxial crystallization on suitable substrates [13][14]. By means of these techniques it is possible to induce orientation of the microdomains and crystalline phase and create long-radius ordered structures. The final morphology depends on competition between crystallization, phase separation and the molecular architecture.
Soft Lithography Techniques
Conventional lithography, based on the use of ultraviolet (UV) radiation sources, is the technology currently employed for the manufacture of electronic microdevices. The resolution of the structures which can be produced with this technology is limited by the wavelength of the radiation used, as well as by the cost of the process which is all the greater the smaller the structures which are to be produced. Moreover, with this technology the use of organic materials is particularly critical because they are typically prone to damage during the conventional lithographic steps.
As an alternative to conventional lithography, which uses radiation or electrons, soft lithography uses fairly simple mechanical processes such as molding, stamping and pressing [17][18]. This technology is becoming increasingly popular since it overcomes the limitation of optical diffraction, allowing structures to be produced which are smaller and, for the same dimensions, have a lower cost; with said technology the processing of organic materials is also possible [19].
All soft lithography techniques have in common the use of stamps made of polydimethysiloxane (PDMS), a “soft” material from which the name of the technology is derived.
In order to produce the stamp, a master is created using photolithography or electron beam lithography in order to create the desired pattern on a substrate made of silicon, silica or other material. The chemical precursor of the PDMS is poured onto the master and is polymerized so as to obtain the solid PDMS stamp.
The manufacture of the master is the most costly part of the process. However, the stamp obtained may be used several times and the technology which uses this stamp is much less costly than photolithography.
Moreover, the same master may be used several times in order to produce several stamps (at least 50).
FIG. 18 shows schematically the steps involved in manufacture of a PDMS stamp from a master.
In order to manufacture the stamp, it is possible to use also other types of polymers such as polyurethanes, polyamides or thermosetting resins, although PDMS remains the polymer of greatest interest. PDMS is in fact resistant and elastic at the same time owing to its siloxanic inorganic structure and the presence of methylene groups attached to this structure.
The PDMS starting precursor is liquid at room temperature and therefore able to permeate perfectly the channels in the master. Upon addition of the activator, which consists in a mixture of a complex formed by platinum and methylhydroxysilane and dimethylsiloxane copolymers, the precursor hardens rapidly, thus being transformed into an elastic solid.
Before using the precursor, it is suggested performing a master silanization treatment which may be performed by means of a vapor of CF 3 (CF 2 ) 6 (CH 2 ) 2 SiCl 3 . The purpose of this treatment is to reproduce more accurately the structures of the master in the stamp and also preserve the master for subsequent use.
Elastomer materials such as PDMS allow easy release of the stamp once manufactured, even if large areas are involved.
The main advantages offered by PDMS are summarized below [18]:
it has a low free interfacial energy and good chemical stability: the molecules or polymers used during the soft lithography process do not react with the surface of the stamp; it does not absorb moisture and therefore does not require special monitoring of the working environment; it allows the gas molecules to pass through very easily, thus allowing also processing of prepolymers which during the reaction phase develop gas molecules; it has a good thermal stability (up to about 186° C. in air), allowing processing of the prepolymers by means of thermal polymerization treatment; it is optically transparent so that it allows processing also of prepolymers which can be polymerized with UV; owing to its elasticity properties the stamp may be deformed mechanically so as to favor the release of the patterned structures; it has excellent durability; it may undergo surface treatment for adaptation to specific materials to be used.
Together with its advantages, PDMS also has a certain number of drawbacks:
plasticization occurs in the presence of apolar solvents such as toluene and hexane; it is subject to 1% shrinkage after polymerization; because of its elasticity and thermal expansion it is difficult to guarantee accuracy over large areas, especially in the case of multilayer manufacturing processes; the softness limits the ratio between height h and width/of the channels in the stamp (h/l ratio of between 0.2 and 2).
A description is now given of various soft lithography techniques which may be used and to which reference will be made to below in the remainder of the description of embodiments of cross-point nanoarrays according to the present disclosure.
Microcontact Printing
The technique of microcontact printing uses relief patterns in the PDMS stamp to transfer a self-assembled monolayer (SAM) onto the surface of a substrate by means of contact, as shown in FIG. 19 .
Microcontact printing differs from other similar stamping techniques owing to the use of self-assembly molecules. These molecules have the property of aggregating spontaneously into stable and well-defined structures by means of non-covalent interaction.
Typically molecules consisting of an alkyl chains terminating in a polar head are used as self-assembly molecules. An example are alcanthiols: in this case the polar head consists of a sulfur atom.
The thickness of a SAM may be adjusted depending on the length of the alkyl chain.
SAMs have very interesting characteristics such as ease of preparation, good stability at the contemplated processing conditions and in particular a low defect density in the final structure.
The best SAM systems are those which are obtained by using alcanthiols, as self-assembly molecules, and gold or silver, as the substrate on which these monolayers are to be deposited. Other numerous combinations of self-assembly layers and substrates are nevertheless described [17].
The microcontact printing technique has, moreover, the advantage of large-scale patterning of surfaces by means of a rolling cylinder stamp, as shown in FIG. 20 .
A SAM pattern deposited by means of microcontact printing may be used as a mask for performing selective etching of the substrate. In fact, the exposed part is etched while the part covered by the SAM is protected.
Generally a SAM has a thickness of a few nanometers so that the choice of the solution to be used for etching is crucial since the SAM must be protected from etching itself. For this reason, a number of solutions suitable both for the particular SAM and for the particular substrate used have been identified.
After etching the metal zones not protected by the SAM, a metal pattern is obtained, situated underneath the SAM pattern which is subsequently removed.
Using the microcontact printing technique it is possible to provide structures with a minimum dimension of less than 100 nm.
FIG. 21 shows SEM images of a variety of metal patterns with a thickness of between 20 and 200 nm obtained by means of SAM of hexadecanthiols. The patterns a) and b) were obtained using a cylindrical stamp, while the remaining patterns c) to f) were obtained using a flat stamp.
Alternatively the SAM patterns, deposited by means of microcontact printing, may be used as templates for the selective deposition of a wide variety of materials such as polymers, inorganic salts, metals and ceramic materials [18].
Micromolding
Differently from the technique of microcontact printing, micromolding uses the channels in the PDMS mold.
Within this technique there are a number of variants such as replica molding (REM), microtransfer tolding (μMT), micromolding in capillaries (MIMIC), solvent-assisted micromolding (SAMIM) and lastly embossing and injection molding.
Those techniques to which reference is made in the specific case of the present patent proposed are now described in detail.
Microtransfer molding (μTM) is an effective method for duplicating the information contained on the surface of the mold. The channels in the mold are filled with the material to be patterned and, after cleaning the excess material from the mold, the latter is turned over and placed on the substrate. In the case of a prepolymer, hardening of the material is achieved by means of heat or UV treatment.
FIG. 22 illustrates schematically the method of using the mold in the case of μTM.
With this technique it is possible to perform molding also on non-continuous surfaces since the material to be molded is supported directly by the mold before setting and is released from the mold only after polymerization has occurred.
Micromolding in Capillaries (MIMIC)
In the MIMIC technique the PDMS mold is placed on the surface of the substrate to be patterned and a low-viscosity liquid is deposited in the opening of the mold channels. This liquid penetrates by means of capillarity inside the channels and fills the entire mold. At this point the material is solidified by means of evaporation of the solvent, in the case of a solution, or by means of heat or UV ray treatment in the case of a prepolymer.
FIG. 23 illustrates schematically the technique of micromolding in capillaries [18].
The structures obtained with evaporation of the solvent are thinner than the thickness of the mold channels, while the width is instead maintained.
By way of an example of this technique, FIG. 24 shows an SEM image of a conductive strip of polyaniline (PANI) obtained by means of MIMIC of a solution of undoped (and therefore soluble) polyaniline in N-methyl-2-pyrrolidone (NMP); following solidification by means of evaporation of the solvent, the material was brought into contact with an aqueous solution of HCl.
Patterning lines of conductive polymer materials, such as PANI, is particularly suitable for the low-cost manufacture of flexible and non-flexible, fully organic, electronic devices.
The technique has a number of drawbacks such as the need for continuity of the channels in order to favor filling of the mold, long filling times and difficult filling due to channels which are long and/or have small diameters. Although structures made with capillaries which have a diameter of less than 50 nm have been illustrated, it should be noted that the slow filling action could limit the usefulness of this technique; moreover with these diameters it is possible to fill only fairly short capillaries. It has been seen, however, that parallel lines of 100 nm diameter and 2 μm length are not subject to particular time restrictions or filling problems.
Among the aspects and advantages of the present disclosure the following deserve particular mention:
a) The use, as an active organic film separating two orthogonal orders of electrodes, of a material comprising oriented, nanostructured, block copolymers which extend across the thickness of the separation film, in which polymer blocks of the block copolymer domains or nanostructures sequester, on the basis of chemical and physical affinity, conductive nanoparticles dispersed in the surrounding organic matrix. This results in a substantial predetermined anisotropy of the separation film which is extraordinarily effective in limiting the possibility that current paths induced in the organic film by localized conditioning factors or agents at a certain cross-over point (matrix cell) may also be formed in neighboring zones of the organic film; and
b) the possibility of achieving a high definition by means of soft lithography. As a result it is possible to achieve an extraordinary degree of compactness.
Theoretically each individual microdomain with the nanoparticles housed in it may form a separate memory element which is perfectly isolated from other adjacent domains and be directed by means of a pair of electrodes.
A method for manufacturing a nanoarray according to the disclosure using currently available techniques is now described by way of example.
Manufacture of Master and Stamp
The first step is to manufacture the master as a single piece formed with a pattern of parallel strips. This master may be manufactured either using an e-beam or by means of optical lithography and the photomask used is as shown in FIG. 25 . In the case of structures which are not too small (˜20 μm), the lithography process may be completely eliminated also during manufacture of the master. It is in fact possible to print directly a CAD pattern on a polymer sheet which may act as a mask one placed in contact with a photoresist [19].
The stamp consisting of polymer material (typically PDMS) is formed on the master using the procedure already described above and illustrated in FIG. 26 .
Deposition of the Top and Bottom Electrodes
After manufacturing the stamp, deposition of the bottom electrodes is performed, followed by deposition of the active layer and the top electrode.
The electrodes are deposited using soft lithography techniques, such as microtransfer molding, micromolding in capillaries and microcontact printing.
It should be noted that, during successive depositions, each layer must be supported by the previous layer. It is possible to fill the empty spaces between the electrode strips of the underlying layer with a dielectric material. In order to fill these spaces, two possible methods may be used: a first possible method consists in depositing the dielectric material everywhere and then, by means of post-treatment, smoothing down until the height of the electrode strips is reached so as to expose the electrodes. A second possible method consists in filling these zones by means of the capillary effect using, for example, the non-patterned surface on the rear of the mold which is deposited on the electrode strips.
Deposition by Means of Microtransfer Molding
In the case of microtransfer molding, the mold may be filled with the material for the electrode and then deposited on the substrate chosen for the device, as shown in FIG. 27 .
After filling with dielectric the empty spaces present between the bottom electrode strips, deposition of the active layer based on block copolymers is performed, as will be described below, followed by deposition, using the same mold, of the top electrode strips by means of microtransfer molding or micromolding in capillaries. These strips are orthogonal with respect to the underlying strips and therefore there are no problems of alignment.
Deposition by Means of Micromolding in Capillaries (MIMIC)
In this case the mold is placed on the substrate and the electrode material is introduced in solution form inside the channels by means of the capillary effect, as shown in FIG. 28 .
After hardening of this first layer, the reduction in thickness following hardening allows introduction, again by means of capillarity, of the solution of active material.
After hardening of this layer, the mold is removed from the substrate and the final structure obtained is the same as that described above.
At this point, deposition of the active layer based on block copolymers is performed, following by deposition of the top electrode strips using the same mold, by means of microtransfer molding or micromolding in capillaries.
Deposition of Self-Aligned Layers by Means of Microcontact Printing
In this case the relief parts of the mold are used to deposit SAMs (self-assembled monolayers) of thiols which are released by means of contact on the substrate previously lined with a layer of metal such as gold or silver. The pattern of thiols reproduces by means of chemical etching a metal pattern which consists precisely in metal strips which constitute the bottom electrodes. The method is illustrated in FIG. 29 .
After hardening of the organic material, the top electrode strips are deposited using the same mold and once again without alignment problems since the strips to be deposited are orthogonal to those already deposited.
Dimensions
The final architecture is that of a dual-electrode memory array in which each individual memory cell has an area defined by the cross-over point of the two electrodes, i.e., bottom electrode and top electrode. Consequently, the minimum size of the memory cell is defined by the resolution of the Soft Lithography techniques used.
From literature on the subject it is known that the minimum dimensions which can be obtained with these techniques are dependent on the minimum dimensions of the master used to manufacture the mold.
Since the master may be manufactured using high-resolution techniques, such as e-beam or FIB technology, the minimum dimensions may be reduced to about 20 nm.
Obviously the minimum dimensions which may be actually achieved are also dependent on the material to be deposited and the complexity of the pattern.
From the point of view of the pattern, the architecture considered is fairly simple since it requires molds with parallel channels. It follows that, in general, memory arrays which can be scaled down to dimensions of 20 nm can be obtained.
In the case of micromolding in capillaries the minimum dimensions which can be reached with the current technology are slightly less, around 50 nm, owing to the difficulties in filling, by means of capillarity, channels which are tens of μm long.
In particular, if a diblock copolymer with a cylindrical morphology in which the cylinders are orthogonal to the plane of the polymer film and arranged in a hexagonal order is to be deposited as the active layer, the dimensions of the mold are dependent on the diameter of the cylinders which are obtained and the average interaxial distance. Therefore, the dimensions of the mold channels, and consequently of the electrodes, must lie within the range of 20-100 nm (in keeping with the cylinder diameter), while the distance between them must be in the range of 40-100 nm (a dimension which is compatible with the distance between the cylinders in an arrangement with a compact hexagonal cross-section).
In each film the cylinders obtained have practically all the same diameter, to within an error of 0.01%, and this also applies to the spacing separating them, which is always the same.
Moreover, in order to ensure alignment between the cylinders and the electrodes, the first electrode must be deposited at a distance from the edge, equal to the diameter of the cylinder, so as to make contact with the second row of cylinders in the pattern as shown in FIG. 30 .
Materials
When choosing the materials, the compatibility of the solvents with the layers previously deposited and with the material of the mold must be assessed in each case.
In relation to the materials which can be used, it is also possible to fill the mold using solutions of precursors of the materials to be deposited. These solutions, owing to the minimum dimensions of the structures which are very critical, undoubtedly facilitate filling of the mold.
Using precursor solutions it is also possible to deposit metal electrodes by means of soft lithography techniques, such as microtransfer molding and micromolding in capillaries.
Top and Bottom Electrodes
In order to produce patterned polymer electrodes, for example a solution of PANI in m-cresol is deposited by means of casting or capillarity inside the PDMS mold [5]; alternatively a solution based on PEDOT (Poly-3,4-ethylenedioxythiophene) in water or particles of carbon in ethanol could be deposited [5,6].
Then the mold is overturned onto a conventional (silicon, glass, etc.) substrate or onto a flexible polymer (PET, PI, etc.) substrate and, after complete evaporation of the solvent, the mold is removed and may be reused, rotating it through 90°, for the second electrode, so as to obtain conductive strips perpendicular to those of the substrate.
In order to produce metal electrodes, in addition to the microcontact printing technique, it is possible to use solutions of inorganic metal precursors or even organic metal precursors such as mercapturic precursors. The latter are preferable because they do not require the presence of a further solution of reducing agents and simply make use of the temperature effect to decompose and form the metal. Moreover, by suitably choosing the organic part, it is possible to obtain precursors which are soluble in different types of solvents, this satisfying the need for the compatibility of the solvents with the mold and any other layers already deposited.
Active Organic Layer
The applicational potential of the block copolymers in surface patterning may be fully exploited if perfect orientation of the microdomains, in particular of the cylinders, perfectly parallel and perpendicular to the surface can be achieved. For this purpose, the application of an electric field and/or a thermal gradient, directional solidification and interaction with the surfaces of the two electrodes making use of topographical effects and epitaxy, are all techniques which have been successful in promoting the anisotropy of the active organic layer based on block copolymers with nanoparticles arranged in an ordered manner in the oriented nanostructures, i.e., in the example considered, in parallel cylinders perpendicular to the electrode surfaces.
For example, it is possible to deposit by means of a spin coater a solution of poly(styrene-b-methylmethacrylate) ((PS(47K)-b-PMMA(140K) with 47K and 140K being the molecular masses, expressed in Kdalton, of the PS and PMMA blocks, respectively) with gold nanoparticles passivated with naphthalenethiol (Au—NF NPs) from toluene on a substrate on which metal or organic electrodes have been deposited beforehand. In the case of the block copolymer considered, there is an excellent orientation of parallel cylinders of polystyrene in the thin deposited film, being perpendicular to the opposite surfaces of the (PS) electrodes separated by polymethylmethacrylate (PMMA). Moreover, the Au—NF conductive nanoparticles, by virtue of their chemical affinity with the PS, are distributed not randomly, but are preferentially sequestered in the ordered microdomains represented by the PS cylinders which are formed in the host mass of PMMA. In this way, the PS cylinders rich in Au—NF nanoparticles form current paths which can be activated by the electric field between the two electrodes of each resistive memory cell at the nanoarray cross-over point.
A sensor device, the response of which is triggered by a variation in the distance between nanostructures caused by the application of mechanical forces and is manifested by means of changes in the optical and/or electrical properties of the device, may comprise nanostructures based on block copolymers in which at least one block is rubbery and contains nanoparticles or clusters of nanoparticles of a conductive, semiconductive and/or ceramic material segregated into the domains of said rubbery blocks, the deformability of which under force produces variations in the distances between the nanostructures.
Hybrid devices with an organic matrix based on block copolymers in which at least one block can be crystallized, able to sequester nanoparticles or clusters of nanoparticles of conductive, semiconductive and/or ceramic materials and to be organized in nanostructures ordered on a large scale in the form of thin films, are useful as precursors for the construction of membranes for microfluid applications, nanostructured electrodes or resists, as well as circuit components integrated in large-area substrates with a high flexibility, mechanical strength and heat resistance, owing to the possibility of using crystallizable blocks with a high melting temperature (for example block copolymers containing blocks of isotactic and/or syndiotactic polypropylene).
BIBLIOGRAPHY
[1] Thomas Mikolajick, The Future of Nonvolatile Memories.
[2] Y. Segui, Bui Ai, H. Carchano, Switching in polystyrene films: Transition from on to off state, J. Appl. Phys . (1976), Vol. 47, No. 1, Pg. 140;
[3] J. Ouyang, C. Chu, C. R. Szmanda, L. Ma, Y. Yang, Programmable polymer thin film and non - volatile memory device, Nature Materials (2004), Vol. 3, Pg. 918;
[4] J. Ouyang, C. Chu, D. Steves, Y. Yang, Electric - field - induced charge transfer between gold nanoparticle and capping 2- naphthalenethiol and organic memory cells, Appl. Phys. Lett . (2005), Vol. 86, No. 12, Pg. 123507;
[5] Y. Yang, J. Ouyang, L. Ma, R. J. Tseng, C. Chu, Electrical Switching and Bistability in Organic/Polymeric Thin Films and Memory Devices, Adv. Funct. Mater . (2006), Vol. 16, Pg 1001;
[6] H. K. Henisch, W. R. Smith, Switching in organic polymer films, Appl. Phys. Lett . (1974), Vol. 24, No. 12, Pg. 589.
[7] G. H. Fredrickson, F. S. Bates, Annu. Rev. Phys. Chem. 1990, 41, 525. L. Leibler, Macromolecules 1980, 13, 1602.
[8] C. Park, J. Yoon, E. L. Thomas, Enabling nanotechnology with self assembled block copolymer patterns Polymer 2003, 44, 6725
[9] Ian W. Hamley in Developments in Block Copolymers , (Ian W. Hamley Ed.) Wiley: Chichester, 2005. Chap. 1, p. 1-29.
[10] P. Mansky, P. M. Chaikin, E. L. Thomas, Monolayer films of diblock copolymer microdominis for nanolithographic applications. J. Mater. Sci. 1995, 30, 1987. M. Park, C. K. Harrison, P. M. Chaikin, R. A. Register, D. H. Adamson, Block copolymer lithography: periodic arrays of 1011 holes in 1 square centimeter. Science 1997, 276, 1401
[11] M. Lazzari, M. A. Lopez Quintela, Block copolymer as a tool for nanomaterial fabrication. Adv. Mater. 2003, 15, 1583.
[12] M. Lazzari, C. De Rosa, Method for alignment and large area-scale ordering of block copolymer morphology. In “Block Copolymers in Nanoscience”, M. Lazzari, G. Liu, S. Lecommandoux Eds., 2006 Wiley-VCH, Verlag GmbH & Co. Weinheim.
[13] De Rosa, C.; Park, C.; Thomas, E. L.; Lotz, B.; Microdomini patterns via directional eutectic solidification and epitaxy, Nature 2000, 405, 433.
[14] Thomas, E. L.; De Rosa, C.; Park, C.; Fasolka, M.; Lotz, B.; Mayes, A. M.; Yoon, J.; Large area orientation of block copolymer microdominis in thin films , U.S. Pat. No. 6,893,705 2005.
[15] Coates, G. W.; Hustad, P. D.; Reinartz, S. Angew. Chem., Int. Ed. Engl. 2002, 41, 2236.
[16] M. Bockstaller, R. A Mickievic, E. L Thomas, Block copolymer nanocomposites: Perspective for tailored functional materials. Adv. Mater. 2005, 17, 1331.
[17] Marko Uplaznik, Review: Introduction to nanotechnology—soft lithography , March 2002.
[18] Annu. Rev. Mater. Sci. 1998. 28: 153-84.
[19] Younan Xia and George M. Whitesides, Soft Lithography, Angew. Chem. Int. Ed. 1998, 37, 550-575.
The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
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A cross-point cell nanoarray comprises a mechanical support substrate, first and second orders of uniformly spaced parallel electrodes separated by an electrically active organic film and orthogonally arranged to form an array of cross-point cells, individually addressable by biasing the respective opposite electrodes, by selecting them among those of the respective orders, over a planar area of the substrate. The active organic resin layer includes a block copolymer of a major component resin and of at least one different minor component resin, configured to promote formation of large-scale ordered nanostructures through phase segregation, due to block incompatibility and self-assembly properties of the blocks. Polymeric bocks of the ordered nanostructures configured to sequester conductive nanoparticles and/or conductive nanoparticle clusters originally dispersed in the component organic resins, subtracting them from the surrounding matrix copolymer. Preferential electric current paths across the thickness of the active organic layer at cross-over points are thus created.
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This application is a continuation of U.S. application Ser. No. 10/401,298, filed Mar. 27, 2003 now U.S. Pat. No. 6,763,674, which claims the benefit of U.S. Provisional Application No. 60/368,194, filed Mar. 27, 2002, both of which are incorporated herein by reference in their entirety.
FIELD
The present invention relates to beverage cooling arts. It finds particular application in conjunction with commercial-type open system ice bins and open system loose auxiliary beverage cooling plates or like devices, and will be described with particular reference thereto. However, it is to be appreciated that the present invention is also amenable to other like applications.
BACKGROUND
Commercially, some vendors employ open ice bin systems for the cooling of beverages (i.e., soft drinks and the like). Often, beverage cooling in such an environment is accomplished by placing a separate loose auxiliary cooling device in an open ice bin and covering it with otherwise potable ice. This can result in the contamination of the potable ice from contact with the auxiliary cooling device and its supporting connections. Consequently, the otherwise potable ice may be changed into “non-potable ice” in accordance with some health codes and deemed not fit for human consumption. This can be disadvantageous insomuch as commercial beverage vendors would like to manually serve ice to their customers out of the same open ice bin. In other words, the current practice of placing the separate loose auxiliary cooling device inside an open ice bin with sufficient ice storage capacity to provide cooling to the auxiliary cooling device and storage for potable ice can be disadvantageous to the extent that it renders the otherwise potable ice unfit for human consumption because ice in direct contact with the auxiliary cooling device and/or supporting connections is considered contaminated by some health code standards.
One option is to have separate distinct open ice bins for the potable ice and the auxiliary cooling device. This is often times inefficient and burdensome on the vendor insomuch as it would mean that the vendor is purchasing and/or maintaining separate dedicated pieces of equipment, presuming space for the same is even available.
Smaller ice pans are sometimes filled with the potable ice and placed in the open ice bin. The customers are served ice out of this smaller ice pan. The rest of the open ice bin, containing the auxiliary cooling device, can then be filled with non-potable ice. This technique essentially divides the ice bin into two distinct ice storage areas, i.e., inside the pan and outside the pan. Accordingly, the potable ice inside the pan remains separate and distinct from the non-potable ice outside the pan, which is in direct contact with the auxiliary cooling device. However, oftentimes, the space restraints of the ice bin do not allow the smaller ice pans to be inserted therein. Further, even if the smaller ice pan does fit, the vendor is still burdened with having to maintain two distinct stores of ice with reduced capacity, which in turn is burdensome to the vendor.
Another solution is to use a cooling device which is sealed from or otherwise outside the ice receiving cavity of the ice bin. However, such a solution does not easily or readily retrofit with respect to existing equipment or open ice bins. Accordingly, use of sealed cooling devices commonly involves the purchase of all new equipment, which can be financially burdensome and foregoes the opportunity to take advantage of existing open system equipment. Sealed cooling devices also tend to be more difficult to service insomuch as they are sealed and often integrated with the ice bin, hence they are typically less accessible than separate loose auxiliary cooling devices. For example, such an ice bin unit with the cooling device sealed in below the surface of the interior ice storage cavity can be costly, and the auxiliary cooling devices may not be readily accessible for cleaning, inspection and/or servicing purposes.
The present invention contemplates a new and improved perforated ice bin insert, which maintains a manual, open system operation utilizing existing open system equipment and overcomes the above-referenced problems and others.
SUMMARY
In accordance with one aspect of the present invention, an ice bin insert is provided for a manual service open ice bin having an ice holding cavity. The insert separates a single store of ice pieces into separate stashes and includes a divider dimension to be received within the ice holding cavity of the ice bin, and support members attached to the divider. The support members hold the divider at a desired position within the ice holding cavity of the ice bin. A plurality of perforations are formed in the divider. The perforations are arranged such that the divider permits ice pieces to flow from a first side thereof to a second side thereof while inhibiting retrieval of ice pieces on the second side from the first side.
In accordance with a more limited aspect of the present invention, the divider and said support members are formed from a substantially rigid material, the support members including at least one wall having a shape which substantially conforms to a contour of an ice bin wall that defines the ice holding cavity of the ice bin.
In accordance with a more limited aspect of the present invention, the divider and support members are formed from a substantially planar unitary sheet of material having a plurality of bends therein which define the divider and support members.
In accordance with a more limited aspect of the present invention, the divider includes a substantially planar first section.
In accordance with a more limited aspect of the present invention, the support members are arranged to hold the divider at a height above a floor of the ice holding cavity of the ice bin. The height is sufficient to permit an auxiliary cooling device and a layer of ice pieces surrounding the same to be arranged between the divider and the floor of the ice holding cavity of the ice bin.
In accordance with a more limited aspect of the present invention, the support members are arranged to hold the first section substantially parallel to the floor of the ice holding cavity of the ice bin.
In accordance with a more limited aspect of the present invention, the divider includes a substantially planar second section arranged between the first section and at least one of the support members, the second section being sloped relative to the first section.
In accordance with a more limited aspect of the present invention, the support members includes substantially planar first and second walls connected to the divider, each of the first and second walls being connected to respective opposing ends of the divider.
In accordance with a more limited aspect of the present invention, the walls are substantially normal to the first section of the divider.
In accordance with a more limited aspect of the present invention, the walls do not permit ice pieces to flow therethrough.
In accordance with a more limited aspect of the present invention, the ice bin insert further includes a channel formed at an end of the first wall opposite the divider. The channel is arranged to receive therein a lip of the ice bin, the lip defining at least a portion of an opening for the ice holding cavity of the ice bin.
In accordance with a more limited aspect of the present invention, the ice bin insert further includes a substantially planar connecting plate formed at an end of the second wall opposite the divider, the connecting plate being arranged for engagement with at least a portion of the ice bin so that the insert is supported therefrom.
In accordance with a more limited aspect of the present invention, the connecting plate is substantially normal to the second wall and arranged so as to rest upon a portion of the ice bin.
In accordance with a more limited aspect of the present invention, the connecting plate includes at least one opening therein for passing through connections to an auxiliary cooling device situated under the insert in the ice holding cavity of the ice bin.
In accordance with a more limited aspect of the present invention, the connecting plate includes holes therein through which fasteners pass to fasten the insert to the ice bin.
In accordance with another aspect of the present invention, an insert for an ice bin includes a vertically extending first wall, the first wall being solid and having opposing first and second ends; a vertically extending second wall, the second wall being solid and having opposing first and second ends; and, a horizontally extending perforated first plate connected between the first ends of the first and second walls. The insert is arranged so as to permit ice pieces to migrate through the first plate and restrict access to ice pieces once they have migrated through the first plate.
In accordance with a more limited aspect of the present invention, the insert includes a perforated second plate connected between the first plate and the second wall, the second plate being sloped with respect to the first plate and permitting ice pieces to migrate therethrough.
In accordance with a more limited aspect of the present invention, the insert includes a channel formed at the second end of the first wall, the channel arranged to receive at least a portion of a lip of an ice bin such that the insert is supported thereon.
In accordance with a more limited aspect of the present invention, the insert includes a connection plate formed at the second end of the second wall, the connection plate arranged to engage with at least a portion of an ice bin such that the insert is supported thereby.
In accordance with a more limited aspect of the present invention, the first and second walls and the first and second plates are formed from a unitary sheet of stainless steel.
In accordance with a more limited aspect of the present invention, a portion of the insert rests upon a portion of the ice bin without being attached thereto such that the insert is supported by the ice bin and selectively removable from and installable in the ice bin, the first plate being positioned inside an ice holding cavity of the ice bin above a floor of the ice holding cavity when the insert is installed in the ice bin.
In accordance with yet another aspect of the present invention, a beverage cooling system includes: an ice bin having an ice holding cavity including a floor and one or more walls defining the cavity and an opening through which ice pieces are selective loaded into and removed from the cavity; a loose auxiliary cooling device separate from the ice bin and placed on the floor inside the cavity of the ice bin; one or more supporting connections operatively connected with the cooling device to circulate a beverage to be cooled through the cooling device; a divider arranged within the ice holding cavity of the ice bin; support members attached to the divider, the support members holding the divider at a desired position above the cooling device within the ice holding cavity of the ice bin; and, a plurality of perforations within the divider, the perforations being arranged such that the divider permits ice pieces to flow from a top side of the divider to a bottom side of the divider while inhibiting retrieval of ice pieces on the bottom side from the top side.
In accordance with a more limited aspect of the present invention, the divider and support members comprise an insert which is selectively removable from the ice bin.
In accordance with a more limited aspect of the present invention, the insert includes cutouts through which the supporting connections are routed when the insert is installed in the ice bin.
In accordance with a more limited aspect of the present invention, the insert extends through the opening of the ice bin when installed therein.
One advantage of the present invention is that it optionally provides the ability to segregate a single store of ice into potable and non-potable portions.
Another advantage of the present invention is that it optionally provides the ability to use a single ice bin unit for both the cooling of auxiliary cooling devices and the storage of ice for consumption.
Yet another advantage of the present invention is that it optionally provides an economically attractive retrofit for existing manual service open ice bin units.
Still further advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention. Further, it is to be appreciated that the drawings are not to scale.
FIG. 1 is a diagrammatic illustration showing a perspective view of an exemplary embodiment of a perforated ice bin insert in accordance with aspects of the present invention.
FIG. 2 is a diagrammatic illustration showing a sectional view of the ice bin insert of FIG. 1 taken along section line 2 — 2 .
FIG. 3 is a diagrammatic illustration showing the perforated ice bin insert of FIG. 1 in an exemplary use in an open ice bin.
FIG. 4 is a diagrammatic illustration showing a perspective view of another exemplary embodiment of a perforated ice bin insert in accordance with aspects of the present invention.
FIG. 5 is a diagrammatic illustration showing a sectional view of the ice bin insert of FIG. 4 taken along section line 5 — 5 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIGS. 1 and 2 , an exemplary embodiment of a perforated ice bin insert 10 in accordance with aspects of the present invention is preferably made out of 304 stainless steel. However, other suitable materials may be used, e.g., other suitable materials preferably are substantially rigid, durable, corrosion resistant and/or non-porous materials which meet or exceed health and safety code specifications for the food and beverage service/preparation industries. In a preferred embodiment, the insert 10 meets or exceeds the National Sanitation Foundation (NSF) guidelines and/or American National Standards Institute (ANSI) standards for the food and beverage service/preparation industries. The insert 10 is preferably of one-piece construction, i.e., a single sheet or plate of material formed with or otherwise made to have multiple perforations 12 and bends. The insert 10 may be dimensioned as desired to fit into various sizes of open ice bins. That is to say, the insert's length, width and/or depth may vary so as to closely match interior dimensions of various manual service open ice bins, i.e., ice bins of the type where a vendor exercises direct access to the ice therein for manual serving of the same.
Preferably, when installed in an ice bin, such as the manual service open ice bin unit 30 as shown in FIG. 3 , at least a portion of a periphery of the insert 10 is attached to and/or rests upon at least a portion of a periphery of the ice bin opening. Alternately, the insert 10 may otherwise be supported in and/or attached to the ice bin 30 . For example, the insert 10 may rest on the bottom floor of the ice bin's storage area, and include legs or other supports that raise the perforated section of the insert 10 above the same.
Referring again to FIGS. 1 and 2 , via the aforementioned bends or otherwise, the insert 10 is preferably formed so that it extends through the opening into an ice storage or holding cavity of the manual service open ice bin unit 30 . In the illustrated embodiment, the insert 10 possesses six primary sections defined by the aforementioned bends. The sections include: a front mounting section A, a front wall section B, first and second floor sections C and D, a rear wall section E, and a rear mounting section F.
As shown, the front mounting section A includes an inverted j-channel 14 arranged to conform to and receive a front lip of the ice bin unit 30 when installed therein (see FIG. 3 ). The inverted j-channel 14 is designed to secure the front section A of the insert 10 to the front of the ice bin unit 30 . The inverted j-channel 14 is preferably sized to fit over the upper lip of the front of the ice bin unit 30 . Accordingly, when installed, the insert 10 firmly rests within the ice storage cavity of the unit 30 with the front section A being supported on and/or by the front lip of the unit 30 . Further, the j-channel 14 allows the front mounting section A to rest securely on the front lip of the unit 30 without having to be physically attached thereto, therefore, the insert 10 can be easily removed for servicing the ice bin unit 30 , completing repairs to the ice bin unit 30 , servicing a separate loose auxiliary cooling device 40 , clearing the unit's drain (not shown), maintaining support connections 42 , etc. Alternately, however, the front section A may be attached to the unit 30 with fasteners. The fasteners may be permanent or selectively removable and are preferably mechanical fasteners (e.g., screws, nuts and bolts, rivets, etc.), but they may be otherwise (e.g., an adhesive, welds, etc.). While either may be used, it is to be appreciated that removable fasteners (as compared to permanent ones) provide for easier detachment of the insert 10 from the unit 30 as desired, e.g., for cleaning, servicing, maintenance, etc. of the insert 10 , the unit 30 , the auxiliary cooling device 40 , support connections 42 or other components. In any event, it is to be appreciated that the front mounting section A may take various optional configurations for support and mounting purposes.
The front wall section B is preferably a substantially vertical wall 16 which follows the contour of the front of the ice bin unit 30 . The vertical wall 16 has 90-degree bends at either end with a bottom end connected to the first floor section C and an opposing top end connected to the front mounting section A. The front wall section B is preferably rigid and provides added strength to the insert 10 so that it does not sag when ice is piled onto the same. The front wall section B is preferably solid and without perforations and is designed to maximize potable ice storage capacity. Similarly, the rear wall section E is also preferably a substantially vertical wall 18 which follows the contour of the rear of the ice bin unit 30 . The vertical wall 18 has bends at either end with a bottom end connected to the second floor section D and an opposing top end connected to the rear mounting section F. The rear wall section E is preferably rigid and provides added strength to the insert 10 so that it does not sag when ice is piled onto the same. The rear wall section E is preferably solid and without perforations and is designed to maximize potable ice storage capacity. Together, the lengths of the vertical walls 16 and 18 determine how far into the ice storage cavity the insert 10 extends. Preferably, these lengths are chosen so that the insert 10 extends into the cavity as much as possible while still leaving room below or otherwise outside the insert 10 for both: (i) the auxiliary cooling device 40 , and (ii) a layer of ice of a selected thickness around the cooling device 40 . The space or gap between the floor of the cavity and the bottom of the insert 10 is suitably in the range of approximately 3 to 5 inches, and preferably, it is approximately 4 inches.
The rear mounting section F preferably includes a substantially horizontal surface 20 which is arranged to be attached to a rear lip of the ice bin unit 30 by removable fasteners, such as screws 22 (as shown in FIG. 3 ), extending through holes 24 (best seen in FIG. 1 ). In this manner, the insert 10 is securely attached to the unit 30 . Alternately, to facilitate quick and easy removal of the insert 10 , the horizontal surface 20 may simply rest upon the rear lip of the ice bin unit 30 without being attached thereto. Additionally, similar to the front mounting section A, other fasteners and/or fastening techniques including permanent or removable fasteners may be used, and the fasteners may be mechanical or otherwise. Furthermore, the rear mounting section F optionally rests upon and/or is attached to a rear backsplash of the unit 30 in addition to or in lieu of resting/attaching to the rear lip of the unit 30 .
Optionally, rather than screws 22 extending through holes 24 to attach the insert 10 to the unit 30 , guide pins having maximum outside dimensions less than the dimension of the holes 24 are arranged on or otherwise extend from a rear lip of the unit 30 . When the insert 10 is installed in the unit 30 , the guide pins mate with and extend through the holes 24 . The holes 24 simply pass over the guide pins as the insert 10 is set into the unit 30 . The guide pins ensure proper positioning of the insert 10 in the unit 30 , and provide additional stabilization for the insert 10 by restricting its lateral movement in the plane horizontal to the rear mounting section F. Attachment with screws 22 or other fasteners can similarly achieves these results. Unlike the guide pins, attachment may also restrict vertical movement (i.e., lifting of the insert 10 out of the unit 30 ). Compared to attachment, however, the guide pins permit relatively quicker and easier removal of the insert 10 from the unit 30 .
The width w of the horizontal surface 20 is preferably chosen so that the vertical wall 18 is spaced apart from the rear wall of the ice bin unit 30 . Preferably, enough room is maintained to run the supporting connections 42 between the vertical wall 18 and the rear wall of the ice bin unit 30 . That is to say, w is sized such that the space or gap between the rear wall of the ice bin unit 30 and the vertical wall 18 of the insert 10 is suitably in the range of approximately 1 to 3 inches, and preferably, it is approximately 2 inches.
The supporting connections 42 extend to and from the auxiliary cooling device 40 sitting in the ice storage cavity of the unit 30 , e.g., as shown in FIG. 3 . The connections 42 include the lines that circulate the beverages to be cooled by the device 40 to and from the same. The horizontal surface 20 preferably has openings or cutouts 26 therein to allow for the connections 42 to pass through the rear mounting section F of the insert 10 , for example, as best seen in FIG. 3 . Optionally, folded down dog ears or tabs 28 (as best seen in FIG. 1 ) aid in guiding the supporting connections 42 through the openings or cutouts 26 .
The bottom sections C and D preferably include an array of perforations 12 . In the exemplary embodiment shown, they are joined together at a 135-degree angle and joined at opposing ends to sections B and E, respectively, at a 90-degree angle and a 135-degree angle. This arrangement of angles is designed to maximize potable ice storage capacity and provide easy access to the potable ice for human consumption. That is to say, the slant of bottom section D urges potable ice to the front of the ice bin unit 30 where it is more easily accessible. In any event, it is to be appreciated that other arrangements and different angular orientations of bottom sections are contemplated, and further, more or less bottom sections may be included. For example, there may be a singular bottom section joined at 90-degree angles to both sections B and E, or the singular bottom section may be joined to sections B and E at selected angles so that it slopes down toward the front of the ice bin unit 30 .
The perforations 12 are preferably arranged and/or sized to permit the migration of ice (e.g., cubes or other pieces, fragments or particles) across the insert 10 , i.e., from inside the insert 10 to outside the insert 10 . The perforations 12 preferably are large enough to allow a sufficient ice flow through the insert 10 while still being small enough to effectively obstruct manual access to or the retrieval of that ice which has passed through the insert 10 . In one suitable embodiment, the perforations 12 are approximately 1.75 by 1.75 inch square cutouts or apertures with rounded corners. However, other sizes and/or shapes for the perforations 12 are contemplated depending on the size and/or shape of the ice pieces being employed.
In operation, the separate loose auxiliary cooling device 40 is first placed in the manual service open ice bin 30 . The insert 10 is then installed with the supporting connections 42 to the cooling device 40 being threaded through the cutouts 26 . Next, ice is loaded into the unit 30 . Ice placed in the unit 30 with the installed insert 10 is free to pass through the insert 10 to surround and cool the cooling device 40 , however, only the ice on the top or which otherwise does not pass through the insert may be readily accessed and manually retrieved for human consumption. Accordingly, the same store of ice is segregated into one stash of manually accessible potable ice inside the insert 10 (i.e., the ice that does not pass through the insert 10 ) and another stash of inaccessible non-potable ice outside the insert 10 (i.e., the ice that does pass through the insert 10 and is potentially contaminated by the cooling device 40 and/or its supporting connections 42 ). In this manner, the insert 10 provides segregation of the auxiliary cooling device 40 and its support connections 42 from the potable ice storage area inside the insert 10 .
With reference to FIGS. 4 and 5 , another exemplary embodiment of a perforated ice bin insert 10 has an additional section G including a wall interposed between sections B and C. As shown, the respective sections meet at 135-degree angles, and the wall of section G has no perforations 12 (although, it may optionally include them). As compared to the 90-degree angle shown in FIG. 1 between sections B and C, the larger angles at which the respective sections B, C and G meet one another permit greater access to and/or easier cleaning at the bends.
The invention has been described with reference to the preferred embodiment(s). Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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An ice bin insert ( 10 ) separates a single store of ice pieces into separate stashes, namely, into potable and non-potable portions. The insert ( 10 ) includes a divider (C, D) dimension to be received within an ice holding cavity of an ice bin ( 30 ). Support members (B, E) attached to the divider (C, D) hold the divider (C, D) at a desired position within the ice holding cavity of the ice bin ( 30 ). A plurality of perforations ( 12 ) are arranged within the divider (C, D) so as to permits ice pieces to flow from a first side thereof to a second side thereof while inhibiting retrieval of ice pieces on the second side from the first side. Preferably, the insert ( 10 ) is constructed from a unitary sheet of stainless steel which is bent to define the respective portions or sections thereof.
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This application claims benefit of Japanese Patent Application No. 2007-263971 filed in Japan on Oct. 10, 2007, the contents of which are incorporated by this reference.
BACKGROUND OF THE INVENTION
The present invention relates to a viewing optical system for viewing an object image formed on a focusing screen, and an imaging apparatus comprising the same.
So far, a single-lens reflex camera used as an imaging apparatus making use of a film or electronic imaging device has comprised an image erection optical system such as a penta roof prism and an eyepiece lens system adapted to guide a light beam leaving that image erection optical system to the eyeball of a viewer for the purpose of viewing an object image on a focusing screen onto which a subject image is projected via a taking lens.
Such viewing optical systems include those designed to make the refractive index of a prism material so high that an optical path for the image erection function of the prism is easily achievable, as set forth in the following patent publications.
[Patent Publication 1]
JP(A)59-148021
[Patent Publication 2]
JP(A)61-156017
[Patent Publication 3]
JP(A)2005-284039
[Patent Publication 4]
JP(A)2005-55874
However, the eyepiece lens system of the viewing optical system set forth in each patent publication has a longer focal length, and when it is intended to obtain a viewing image having a wide field of view, there is no option but to increase image size on a focusing screen: it is unsuitable for diminishing prism size. On the other hand, digital single-lens reflex cameras are now in wide use as imaging apparatus. However, imaging plane size is smaller than that of a conventional Leica size film: when the aforesaid viewing optical system is used, the viewing angle of field tends to become small.
The present invention has for its object the provision of a viewing optical system that, albeit being of small size, enables subjects to be easily viewed over a wide view of field by some significant tweaks to a lens system while taking advantage of the merit of making sure an optical path length by use of a prism having a high refractive index, and an imaging apparatus comprising the same.
SUMMARY OF THE INVENTION
According to the invention, the aforesaid object is accomplishable as mentioned below.
That is, the invention provides a viewing optical system comprising a screen on which an object image taken via a taking lens is formed, an image erection optical system for erecting the object image formed on said screen, and an eyepiece lens optical system of positive refracting power for guiding a light beam leaving said image erection optical system to the eyeball of a viewer, wherein said image erection optical system comprises a prism having an internal reflective surface, and said eyepiece optical system comprises, in order from a screen side to an exit pupil side, a first lens component of negative refracting power wherein its exit pupil side surface has a paraxial-radius-of-curvature absolute value smaller than a paraxial-radius-of-curvature absolute value of its screen side surface, a second lens component having a double-convex shape, and a third lens component having a meniscus shape concave on its exit pupil side, with satisfaction of the following conditions (1), (2) and (3):
1.55<ndp (1)
0.35 <fe/Dip< 0.60 (2)
1.0 <D 3/( D 1 +D 2)<1.8 (3)
where ndp is the d-line refractive index of the prism;
fe is the focal length of the eyepiece lens system provided that when diopter adjustment is implemented by movement of the lens components, it is going to be the focal length of the eyepiece lens system at −1 diopter;
Dip is an optical path length along an optical axis from an image formation position on the screen to the exit surface of the prism;
D 1 is the thickness on the optical axis of the first lens component;
D 2 is the thickness on the optical axis of the second lens component;
D 3 is the thickness on the optical axis of the third lens component; and
the lens components are lenses that are identifiable by an air contact surface, wherein each lens is a single lens or a cemented lens.
As the refractive index of the prism grows high in such a way as to satisfy condition (1), it facilitates making sure an optical path even when the focal length of the eyepiece lens system is curtailed. And to make the prism much smaller while making sure the field of view, it is preferable to curtail the focal length of the eyepiece lens system in such a way as to satisfy condition (2), thereby taking hold of the field of view. To, in that case, make sure the field of view and layout and take hold of optical performance, it is preferable to tweak the arrangement of the eyepiece lens system, thereby facilitating making sure the field of view while placing the principle points closer to the screen.
In the viewing optical system of the invention, the eyepiece lens system is set up and configured as mentioned above.
With such configuration, the positive refracting power of the second lens component on which the main positive refracting power of the eyepiece lens system concentrates is shared by both its surfaces, and aberrations at the second lens component are canceled out by the negative refracting power of the first lens component. Further, the second lens component is configured in such a way as to have a concave surface on the exit pupil side so that off-axis light rays are flipped up while holding back the occurrence of aberrations, working favorably for setting up a wide field-of-view arrangement.
And the third lens component is configured as a meniscus shape concave on the exit pupil side to bring the principal points of the eyepiece lens system nearer to the screen side. This works favorably for making sure the space to receive the prism even when the focal length of the eyepiece lens system is curtailed.
And if the third lens component is configured as a meniscus shape concave on the exit pupil side, it is then possible to diminish the angle of off-axis light beams incident on, and leaving, the third lens component, thereby holding back the occurrence of off-axis aberrations.
Here, if the thickness on the optical axis of the second lens component is ensured in such a way as to satisfy condition (3), then it works more favorably for correction of field curvature, because the principal points of the eyepiece lens system can be located nearer to the screen.
By abiding by at least the lower limit of condition (1), the optical path length of the prism with respect to a length as calculated on an air basis is kept so long that even when the focal length of the eyepiece lens system is cut down, it is easy to make sure the optical path for image erection.
Further to condition (1), there may be the upper limit added, as described below.
1.55<ndp<2.5 (1)′
Abiding by at least the upper limit of 2.5 to condition (1)′ is preferable for reducing material costs.
Abiding by at least the lower limit of condition (2) helps reduce the refracting power of the eyepiece lens system so that the curvature of each lens surface is easily reduced and design with limited aberrations is easily achievable. Further, abiding by at least the upper limit of condition (2) makes sure the refracting power of the eyepiece lens system, working favorably for setting up a wide field-of-view arrangement.
Abiding by at least the lower limit of condition (3) makes sure the thickness of the third lens component, working favorably for adjustment of the principal points and correction of field curvature. It is also preferable to abide by at least the upper limit of condition (3), because it is easy to make sure an eye point (the distance from the eyepiece lens system to the exit pupil).
Further, it is more preferable to satisfy one or more of the following requirements at the same time.
For the eyepiece lens system, it is preferable to satisfy the following condition (4):
0.5 <f 2 /fe< 1.0 (4)
Here f 2 is the focal length of the second lens component.
Condition (4) defines the more preferable refracting power of the second lens component. Abiding by at least the lower limit of condition (4) holds back the refracting power of the second lens component and the sharing of positive refracting power on the convex surface of the third lens component on the screen side works favorably for decreases in various aberrations and decreases in aberration fluctuations due to decentration. It is also preferable to abiding by at least the upper limit of condition (4), because the positive refracting power of the second lens component is ensured and it is possible to place the refracting power or principal points of the eyepiece lens system nearer to the screen.
For the eyepiece lens system, it is also preferable to satisfy the following condition (5):
−0.4 <f 2 /f 1<−0.2 (5)
Here f 1 is the focal length of the first lens component, and f 2 is the focal length of the second lens component.
Condition (5) defines a more preferable refracting power balance between the first lens component and the second lens component. It is preferable to abide by at least the lower limit of condition (5), because the negative refracting power of the first lens component is kept moderate: it works favorably for reducing the size of the eyepiece lens system. It is also preferable to abide by at least the upper limit of condition (5), because the negative refracting power of the first lens component is ensured to make sure an aberration correction function and a function of enlarging the field of view.
The third lens component here is a cemented doublet lens comprising a positive lens and a negative lens in order from the screen side, and for that doublet lens it is preferable to satisfy the following condition (6):
10 <vd 3 p−vd 3 n< 60 (6)
Here vd 3 p is the Abbe constant on a d-line basis of the positive lens in the third lens component, and vd 3 n is the Abbe constant on a d-line basis of the negative lens in the third lens component.
The third lens component has an increased thickness on the optical axis; it is preferable for this lens component to comprise a positive lens and a negative lens, thereby having a chromatic aberration correction function. Condition (6) defines one that is preferable for correction of chromatic aberrations. It is preferable to abide by at least the lower limit of condition (6), because the dispersion of the negative lens is ensured to facilitate correction of chromatic aberrations. It is also preferable to abide by at least the upper limit of condition (6), because the material of the negative lens or positive lens is prevented from having too large anomalous dispersion, thereby holding back the secondary spectra.
For the third lens component it is also preferable to satisfy the following condition (7):
−0.55 <f 3 n/f 3 p<− 0.45 (7)
Here f 3 p is the focal length of the positive lens in the third lens component, and f 3 n is the focal length of the negative lens in the third lens component.
Condition (7) defines a more preferable refracting power balance between the positive lens and the negative lens in the third lens component. It is preferable to abide by at least the lower limit of condition (7), because the refracting power of the negative lens is ensured: it works favorably for adjustment of the principal points and correction of aberrations such as chromatic aberrations. In view of aberration balances, it is also preferable to abide by at least the upper limit of condition (7), because the refracting power of the positive lens is ensured to share the positive refracting power with it and the second lens group while making sure the positive refracting power of the eyepiece lens system.
For the third lens component it is also preferable to satisfy the following conditions (8) and (9):
0.30 <R 3 f/fe <0.60 (8)
0.20 <R 3 r/fe <0.35 (9)
Here R 3 f is the paraxial radius of curvature of the entrance-side surface of the third lens component, and R 3 r is the paraxial radius of curvature of the exit-side surface of the third lens component.
These conditions define together more preferable relationships for making sure the principal points and aberration correction function of the third lens component.
Condition (8) defines the paraxial radius of curvature of the third lens component at the entrance-side surface. As far as condition (8) is satisfied, it is easy to diminish the angle of incidence of off-axis light beams on the entrance-side surface so that the occurrence of off-axis aberrations is held back, and the positive refracting power is suitably shared with the third lens component: this works favorably for reductions of axial aberrations, etc.
Condition (9) defines the paraxial radius of curvature of the third lens component at the exit-side surface. As far as condition (9) is satisfied, it is easy to diminish the angle of incidence of off-axis light beams leaving the exit-side surface so that the occurrence of off-axis aberrations is held back, and a suitable negative refracting power is ensured to make sure the functions of adjusting the principal points and canceling out various aberrations.
The positive and negative lenses in the third lens component are preferably each a meniscus lens concave on the exit pupil side.
It is then easy to reduce the angle of incidence of off-axis light beams on the cementing surface of the third lens component, thereby reducing the influence on aberrations of the decentration of the third lens component.
For the second lens component it is also preferable to have an aspheric convex surface in which the absolute value of curvature becomes small with a distance from the optical axis.
The second lens component is one that has an increasing positive refracting power, and is located at a position where an axial light beam is suitably spaced away from an off-axis light beam. For this reason, if the second lens component is allowed to have the aforesaid aspheric surface, it is easy to correct both axial aberrations and off-axis aberrations.
The first lens component is also preferably of a meniscus shape convex on the screen side.
That meniscus shape helps reduce the negative refracting power of the first lens component so that the first lens component can have an increased curvature at the exit pupil-side surface while mitigating influences on the principal points, thereby favorably making sure the function of canceling out aberrations at the second lens component, or favorably making sure the space for movement of the second lens component for diopter adjustment.
The first lens component, and the aforesaid second lens component is preferably a single lens.
Such an arrangement works favorably for cost reductions, and size reductions as well.
Further, the second lens component is preferably movable along the optical axis of the viewing optical system.
More preferably, the second lens component is easy to have a suitable refracting power, and movable for diopeter adjustment.
The image erection optical system is preferably a penta room prism having a roof reflective surface.
The use of the penta roof prism makes it possible to bend back the optical path, working favorably for reductions in the size of the image erection optical system.
The present invention also provides an imaging apparatus comprising an imaging device located on a taking optical path and adapted to receive an image formed via a taking lens for conversion into electrical signals, a reflecting mirror for splitting an optical path from the taking lens into a viewing optical path and a taking optical path, and a viewing optical system located on said viewing optical path side.
The imaging device is more likely to be restricted by the angle of incidence of light rays than films. For this reason, the size of the imaging plane of the imaging device is suitably diminished so that the taking lens is of suitable size, too, while allowing light to be almost vertically incident on the light receptor surface of the imaging device.
On the other hand, as the imaging plane is small, it makes it easy to diminish the viewing angle of field; if the inventive viewing optical system is used, it is preferable because there can be an imaging apparatus set up, which, albeit being of small size, can view subjects over a wide field of view.
Two or more of the aforesaid aspects of the invention are preferably satisfied at the same time, because the viewing optical system grows much smaller and performs much better.
Two or more of the aforesaid conditions are preferably satisfied at the same time, too.
More preferably, each condition should be narrowed down as follows.
More preferably, the lower limit of condition (1), (1)′ is set at 1.57, especially 1.58. More preferably, the upper limit is set at 2.1, especially 1.9.
More preferably, the lower limit of condition (2) is set at 0.40, especially 0.45. More preferably, the upper limit is set at 0.55, especially 0.51.
More preferably, the lower limit of condition (3) is set at 1.1, especially 1.2. More preferably, the upper limit is set at 1.7, especially 1.6.
More preferably, the lower limit of condition (4) is set at 0.6, especially 0.7. More preferably, the upper limit is set at 0.9, especially 0.83.
More preferably, the lower limit of condition (5) is set at −0.37, especially −0.35. More preferably, the upper limit is set at −0.25, especially −0.30.
More preferably, the lower limit of condition (6) is set at 15, especially 20. More preferably, the upper limit is set at 40, especially 30.
More preferably, the lower limit of condition (7) is set at −0.53, especially −0.51. More preferably, the upper limit is set at −0.47, especially −0.49.
More preferably, the lower limit of condition (8) is set at 0.35, especially 0.40. More preferably, the upper limit is set at 0.55, especially 0.50.
More preferably, the lower limit of condition (9) is set at 0.23, especially 0.25. More preferably, the upper limit is set at 0.32, especially 0.28.
According to the invention, it is possible to obtain a viewing optical system that, albeit being of small size, can view subjects over a wide field of view by tweaking the eyepiece lens system while taking advantage of the merit of making sure the optical path length by use of a prism having a high refractive index.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is illustrative in schematic, common to the respective examples, of the arrangement of one embodiment of a single-lens reflex camera comprising the inventive viewing optical system.
FIG. 2 is illustrative in section along the optical axis of the optical arrangement according to the first example of the viewing optical system, and the imaging apparatus according to the invention.
FIG. 3 is an aberration diagram for spherical aberrations, field curvature, distortion and chromatic aberration of magnification in the first example.
FIG. 4 is illustrative in section along the optical axis of the optical arrangement according to the second example of the viewing optical system, and the imaging apparatus according to the invention.
FIG. 5 is an aberration diagram for spherical aberrations, field curvature, distortion and chromatic aberration of magnification in the second example.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Some examples of the invention are now explained with reference to the drawings.
FIG. 1 is illustrative in schematic, common to the respective examples, of the arrangement of one embodiment of a single-lens reflex camera comprising the inventive viewing optical system.
In a single-lens reflex camera 1 of FIG. 1 , a taking lens 2 is interchangeably attached to the camera by a mount (not shown). Note here that even an arrangement that does not include a taking lens is herein defined as a single-lens reflex camera (imaging apparatus) provided that the taking lens is attachable to it.
In FIG. 1 , reference numeral 4 is a CCD (or CMOS or the like). On the basis of signals from this CCD, image processing is implemented at a processing circuit to store image information in a memory. The stored image may be displayed on a personal computer (not shown) or the like, or it may be recorded and stored in various storage media.
Reference numeral 5 is a quick return mirror located on an optical axis 3 of a taking lens 2 between the taking lens 2 and CCD 4 , and 6 a finder screen located on a path of light reflected by the quick return mirror, wherein its entrance surface or exit surface is sand polished. On this surface there is an object image formed. By movement of the quick return mirror 5 , a taking optical path is time split from a viewing optical path.
Reference numeral 7 is a penta roof prism acting as an image erection optical system, which prism is made up of, in order from its optical path, a planar entrance surface 7 a , a roof reflective surface 7 b , a planar reflective surface 7 c , and a planar exit surface 7 d , and is adapted to erect an object image formed on the screen plane. For the image erection optical system, there may be a mode for reflecting an optical path the way a Porro prism does; however, the penta roof prism is more advantageous over it in terms of size reductions.
The penta roof prism or eyepiece lens system is embodied as shown in the examples given later.
On the exit side of the eyepiece lens system 8 , there is a plane-parallel plate 9 provided as a cover glass. This cover glass may be dispensed with, if the lens component of the eyepiece lens system on the exit pupil side is designed as a cover glass.
And an exiting light beam is guided to the pupil 10 of a viewer positioned near the exit pupil so that the image to be taken can be viewed.
It is here noted that the single-lens reflex camera may be designed such that the taking lens 2 is integral with the camera body: it is not interchangeable.
It is also noted that a half-silvered mirror or an optical path splitter prism may be used instead of the quick return mirror 5 .
Further, it is noted that the screen surface may be not only sand polished but also constructed of a set of microprisms lining up in a two-dimensional pattern, a hologram plane or the like.
Still further, it is noted that the surface in opposition to the screen surface 6 may be constructed of an optical surface having convergent action such as a Fresnel or convex surface to enhance the collective action at the periphery of the screen.
If optical refractive power is given to the entrance or exit surface of the prism that is the image erection optical system or there is a field lens disposed near the screen surface 6 , it is then possible to make correction of aberrations and collective efficiency much better.
FIG. 2 is illustrative in section along the optical axis of the optical arrangement according to the first example of the viewing optical system and imaging apparatus of the invention; (a) is illustrative of what goes on at a diopter of −1m−1, (b) what goes on at a diopter of +1m−1, and (c) what goes on at a diopter of −3m−1.
As regards a plane-parallel plate member in FIG. 2 , it is noted that for convenience of illustration, the penta roof prism is shown in a taken-apart form. The cover glass is given as calculated on an air basis, and so is not shown.
FIG. 3 is an aberration diagram for spherical aberrations, field curvature, distortion and chromatic aberration of magnification in the first example; (a) is illustrative of what goes on at a diopter of −1m−1, (b) what goes on at a diopter of +1m−1, and (c) what goes on at a diopter of −3m−1. It is here noted that FIG. 3 is presented with diopter (m−1) as abscissa for spherical aberrations and field curvature and angle (min.) as abscissa for chromatic aberration of magnification. It is also noted that the spherical aberrations and chromatic aberration of magnification are represented by figures at the wavelengths of 587.6 nm (d-line: solid line), 486.1 nm (F-line: one-dot chain line) and 656.3 nm (C-line: dotted line), and as regards astigmatism, a solid line is indicative of a sagittal image surface and a dotted line of a meridional image surface.
The viewing optical system, and the imaging apparatus according to the first example comprises a focusing screen 6 having a sand polished surface, on which an object image is to be formed, a penta roof prism 7 and an eyepiece lens system 8 .
The eyepiece lens system 8 is made up of, in order from the screen side, a first lens component 8 a consisting of a negative meniscus lens convex on the screen side, a second lens component 8 b consisting of a double-convex positive lens, and a third lens component 8 c that consists of a cemented lens of a positive meniscus lens convex on the screen side and a negative meniscus lens convex on the screen side and has negative refracting power. Diopter adjustment is implemented by moving the second lens component 8 b.
Two aspheric surfaces are used: one at the exit pupil-side surface of the negative meniscus lens that is the first lens component 8 a and one the screen side of the double-convex positive lens that is the second lens component 8 b.
Enumerated below are the numerical data about the viewing optical system according to the first example.
In the respective examples given below, r is the paraxial radius of curvature of a lens surface, d is a lens thickness and an air separation, nd and vd are a refractive index and an Abbe constant on a d-line (λ=587.6 nm) basis. K is a conical coefficient, A 4 , A 6 , A 8 and A 10 are aspheric coefficients, and E±n is indicative of ×10±n.
Using each aspheric coefficient in each example, each aspheric shape is represented by the following formula:
Z =( Y 2 /r )/[1+{1−(1+ K )·( Y/r )2}½ ]+A 4 ×Y 4 +A 6 ×Y 6 +A 8 ×Y 8 +A 10 ×Y 10
where Z is acoordinates in the optical axis direction, and Y is coordinates in the direction vertical to the optical axis direction.
Numerical Example 1
Unit: mm
Surface data
Surface No.
r
d
nd
νd
Object image
∞
4.9
(sand polished
surface)
1
∞
85
1.58313
59.38
2
∞
0.8
3
125.21
1.8
1.58423
30.49
4 (aspheric)
42.6776
variable
5 (aspheric)
24.8349
7.3
1.52542
55.78
6
−65.978
variable
7
19.65
6.7
1.7725
49.6
8
34.06
6.8
1.78472
25.68
9
11.423
19
Exit pupil
∞
Aspheric data
Fifth surface
K = 1.98, A4 = −4.9135E−06, A6 = −5.9000E−09
Sixth surface
K = −0.147, A4 = −1.1114E−05, A6 = −8.3900E−09
Various data
Diopter (m−1)
+1
−1
−3
Focal length
42.9868
43.4294
43.9064
Angle of field
28.5553°
28.9875°
28.0010°
Pupil diameter (diameter) φ = 8 mm
Object image diagonal length 22 mm
d5
4.22823
2.61562
0.991
d7
0.97177
2.58438
4.209
Focal length of each lens
First lens component
−111.7218
Second lens component
35.3185
Third lens component
−117.6477
Positive lens in the third lens component
49.993
Negative lens in the third lens component
−25.235
FIG. 4 is illustrative in section along an optical axis of the optical arrangement according to the second example of the viewing optical system and imaging apparatus of the invention; (a) is illustrative of what goes on at a diopter of −1m−1, (b) what goes on at a diopter of +1m−1, and (c) what goes on at a diopter of −3m−1.
As regards a plane-parallel plate member in FIG. 4 , it is noted that for convenience of illustration, the penta roof prism is shown in a taken-apart form. The cover glass is given as calculated on an air basis, and so is not shown.
FIG. 5 is an aberration diagram for spherical aberrations, field curvature, distortion and chromatic aberration of magnification in the first example; (a) is illustrative of what goes on at a diopter of −1m−1, (b) what goes on at a diopter of +1m−1, and (c) what goes on at a diopter of −3m−1. It is here noted that FIG. 5 is presented with diopter (m−1) as abscissa for spherical aberrations and field curvature, and angle (min.) as abscissa for chromatic aberration of magnification. It is also noted that the spherical aberrations and chromatic aberration of magnification are represented by figures at the wavelengths of 587.6 nm (d-line: solid line), 486.1 nm (F-line: one-dot chain line) and 656.3 nm (C-line: dotted line), and as regards astigmatism, a solid line is indicative of a sagittal image surface and a dotted line of a meridional image surface.
The viewing optical system, and the imaging apparatus according to the second example comprises a focusing screen 6 having a sand polished surface, on which an object image is to be formed, a penta roof prism 7 and an eyepiece lens system 8 .
The eyepiece lens system 8 is made up of, in order from the screen side, a first lens component 8 a consisting of a negative meniscus lens convex on the screen side, a second lens component 8 b consisting of a double-convex positive lens, and a third lens component 8 c that consists of a cemented lens of a positive meniscus lens convex on the screen side and a negative meniscus lens convex on the screen side and has negative refracting power. Diopter adjustment is implemented by the movement of the second lens component 8 b.
One aspheric surface is used on the screen side of the double-convex positive lens that is the second lens component 8 b.
Enumerated below are the numerical data about the viewing optical system according to the second example.
Numerical Example 2
Unit: mm
Surface data
Surface No.
r
d
nd
νd
Object image
∞
4.9
(sand polished
surface)
1
∞
85
1.58313
59.38
2
∞
0.8
3
157.5957
1.8
1.58423
30.49
4
41.8732
variable
5 (aspheric)
23.528
8
1.52542
55.78
6
−61.2841
variable
7
19.05334
6.5
1.7725
49.6
8
30.049
6
1.78472
25.68
9
11.2086
19
Exit pupil
∞
Aspheric data
Fifth surface
K = 1.98, A4 = −4.9135E−06, A6 = −5.9000E−09
Sixth surface
K = −0.2918, A4 = −1.0541E−05, A6 = −2.8530E−09, A8 = −1.0497E−11
Various data
Diopter (m−1)
+1
−1
−3
Focal length
43.7688
44.3413
44.9344
Angle of field
28.0996°
28.2719°
27.7910°
Pupil diameter (diameter) φ = 8 mm
Object image diagonal length 22 mm
d5
4.22823
2.61562
0.991
d7
0.97177
2.58438
4.209
Focal length of each lens
First lens component
−98.1697
Second lens component
33.4436
Third lens component
−110.0467
Positive lens in the third lens component
53.5955
Negative lens in the third lens component
−26.4904
Enumerated below are the values of conditions (1) to
(9) in the respective examples.
Condition
Example 1
Example 2
(1)
1.58313
1.58313
(2)
0.483086
0.493229
(3)
1.483516
1.27551
(4)
0.813239
0.754231
(5)
−0.31613
−0.34067
(6)
23.92
23.92
(7)
−0.50477
−0.49427
(8)
0.452458
0.429699
(9)
0.263025
0.25278
Enumerated below are the parameter values in the respective examples.
Parameter
Example 1
Example 2
ndp
1.58313
1.58313
Fe
43.4294
44.3413
dip
89.9
89.9
d1
1.8
1.8
d2
7.3
8
d3
13.5
12.5
f1
−111.722
−98.1697
f2
35.3185
33.4436
f3p
49.993
53.5955
f3n
−25.235
−26.4904
νd3p
49.6
49.6
νd3n
25.68
25.68
R3f
19.65
19.0534
R3r
11.423
11.2086
In addition to the features recited in the claims, the viewing optical system of the invention, and the imaging apparatus comprising it has such features as mentioned below.
A. A viewing optical system, comprising:
a screen on which an object image taken via a taking lens is formed,
an image erection optical system for erecting an object image formed on said screen, and
an eyepiece lens system having positive refracting power for guiding a light beam leaving said image erection optical system to the eyeball of a viewer, wherein:
said image erection optical system comprises a prism having an internal reflective surface,
said eyepiece comprises, in order from the screen side to an exit pupil side,
a first lens component having negative refracting power,
a second lens component having positive refracting power, and
a third lens component configured in a meniscus shape concave on the exit pupil side, with the satisfaction of the following conditions (1) and (2):
1.55<ndp (1)
0.35 <re/Dip< 0.60 (2)
where ndp is the d-line refractive index of the prism;
fe is the focal length of the eyepiece lens system provided that when diopter adjustment is implemented, it is going to be the focal length of the eyepiece lens system at −1 diopter;
Dip is an optical path length along an optical axis from an image formation position on the screen to the exit surface of the prism; and
the lens components are lenses that are identifiable by an air contact surface, wherein each lens is a single lens or a cemented lens.
B. An imaging apparatus, comprising:
an imaging device located on a taking optical path and adapted to receive an image formed via a taking lens for conversion into electrical signals,
a reflecting mirror for splitting an optical path from the taking lens into a viewing optical path and a taking optical path, and
a viewing optical system as recited in the aforesaid A and located on said viewing optical path side.
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The invention relates to a viewing optical system for viewing an object image formed on a focusing screen, and an imaging apparatus comprising the same. An image erection optical system comprises a prism having an internal reflective surface. An eyepiece optical system comprises, in order from a screen side to an exit pupil side, a first lens component having negative refracting power wherein its exit pupil-side surface has a paraxial-radius-of-curvature absolute value smaller than that of its screen-side surface, a second lens component in a double-convex shape and a third meniscus lens component in a meniscus shape concave on an exit pupil side. The total number of lens components included in the eyepiece optical system is 3, and the following conditions (1), (2) and (3) are satisfied.
1.55<ndp (1)
0.35< fe/Dip <0.60 (2)
1.0< D 3/( D 1+ D 2)<1.8 (3)
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PRIORITY
This application claims the priority benefit of U.S. Provisional Application No. 61/980,035 filed on Apr. 15, 2014, which is hereby incorporated herein by reference in its entirety.
FIELD
The present invention relates generally to poles for mounting parking meters and similar devices.
BACKGROUND
There is a need to mount parking meters at a given height above the ground to facilitate the ease of use by users parking their vehicles. Typically a parking meter is mounted on a pole. Conventional poles are simply a length of hollow steel tube. The metal tube is typically sunk into a recess formed in the concrete while it is still wet so that the hardened concrete retains the pole in place. Alternatively, a bottom mounting flange can be secured to the pole at the bottom end thereof, and the flange is fastened to bolts protruding from the cement slab.
The conventional pole systems present multiple drawbacks. First, it is difficult or impossible to run electrical power and communication lines or wiring up through the pole to the meter if the meter requires such connectivity. Second, the rotational alignment of the pole with respect to the meter cannot be changed. Thus, the meter may not be capable of being ideally aligned with respect to the street, or the pole must be replaced when the meter is replaced. Also, exposed mounting hardware at the base of the pole is vulnerable to vandals and thieves who may unbolt and steal the meter. Thus, there is a need for an improved pole mount, mounting system and method of mounting a parking meter.
SUMMARY
The present invention provides a unique pole mounting system for parking meters and the like. The pole mounting system can be configured as a center drawn mounting system which allows the user to securely mount and adjust the inner stanchion in various rotational orientations about the vertical axis. The system also allows any electrical wire or other conduit to be run up inside of the pole. Once the inner stanchion is fastened in place, the outer stanchion fits over top with a first disc on the outer stanchion interlocking with a disc recess on the inner stanchion, thereby preventing the outer stanchion from twisting. Once a locking bolt is in place and the meter is fastened to the top of the stanchion, there is no accessing any of the electrical or mounting hardware, which makes it tamper resistant.
The disclosure includes a parking meter mounting system. The system can include an inner stanchion comprising an elongated body having an upper end and an opposing lower end, and an outer stanchion, comprising an elongated hollow tubular body having an open top end and a bottom end, wherein the inner stanchion is disposed inside of the hollow tubular body. A support plate can be secured to the elongated body of the inner stanchion adjacent the lower end thereof. A receiving disc can be disposed atop the support plate, the receiving disc including an open interior defined by an inner circumference. An interlocking disc can be secured to the bottom end of the hollow tubular body of the outer stanchion, the interlocking disc having an outer circumferential shape configured to register with the inner circumference of the receiving disc to define multiple fixed rotational orientations of the outer stanchion about a vertical axis thereof. At least one aperture can be defined through the support plate to permit the passage of an electrical wiring. A gap also can be formed between the elongated body of the inner stanchion and the hollow tubular body of the outer stanchion of sufficient dimension to permit passage of the electrical wiring from the support plate to the top end of the upper stanchion.
The disclosure also includes a mounting device. The mounting device can include an inner stanchion, comprising an elongated body having an upper end and an opposing lower end, and an outer stanchion, comprising an elongated hollow tubular body having an open top end and a bottom end, wherein the inner stanchion is disposed inside of the hollow tubular body. A support plate can be secured to the elongated body of the inner stanchion adjacent the lower end thereof. A receiving disc can be disposed atop the support plate, the receiving disc including an open interior defined by an inner circumference. An interlocking disc can be secured to the bottom end of the hollow tubular body of the outer stanchion, the interlocking disc having an outer circumferential shape configured to register with the inner circumference of the receiving disc to define multiple fixed rotational orientations of the outer stanchion about a vertical axis thereof. A mounting block can be disposed inside the hollow tubular body adjacent the open top end thereof, wherein the mounting block is releasably secured to the inner stanchion.
The disclosure further includes a method of mounting a parking meter. The method can include securing an interlocking disc to a bottom end of an outer stanchion and disposing an outer stanchion over an inner stanchion assembly. An the interlocking disc of the outer stanchion can be disposed within one of a multiple of fixed rotational orientation positions defined in a recessed region of an inner stanchion assembly to secure the outer stanchion from future rotational movement. A mounting block can be disposed inside of the outer stanchion adjacent a top end thereof. The mounting block can be secured to the inner stanchion assembly. The parking can be secured atop the outer stanchion.
The above summary is not intended to limit the scope of the invention, or describe each embodiment, aspect, implementation, feature or advantage of the invention. The detailed technology and preferred embodiments for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. It is understood that the features mentioned hereinbefore and those to be commented on hereinafter may be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pole system according to certain example embodiments.
FIG. 2 is a top view of a pole system according to certain example embodiments.
FIG. 3 is a side view of a pole system according to certain example embodiments.
FIG. 4 is a cross-sectional view of a pole system along line A-A in FIG. 3 , according to certain example embodiments.
FIG. 5 is a perspective view of an inner stanchion of a pole system according to certain example embodiments.
FIG. 6 is a top view of an inner stanchion of a pole system according to certain example embodiments.
FIG. 7 is a side view of an inner stanchion of a pole system according to certain example embodiments.
FIG. 8 is a cross-sectional view of an inner stanchion of a pole system along line A-A in FIG. 7 , according to certain example embodiments.
FIG. 9 is a perspective view of an outer stanchion of a pole system according to certain example embodiments.
FIG. 10 is a top view of an outer stanchion of a pole system according to certain example embodiments.
FIG. 11 is a side view of an outer stanchion of a pole system according to certain example embodiments.
FIG. 12 is a cross-sectional view of an outer stanchion of a pole system along line A-A in FIG. 11 , according to certain example embodiments.
FIG. 13 is a side view of a receiving disc of an inner stanchion of a pole system according to certain example embodiments.
FIG. 14 is a front view of a receiving disc of an inner stanchion of a pole system according to certain example embodiments.
FIG. 15 is a side view of a support plate of an inner stanchion of a pole system according to certain example embodiments.
FIG. 16 is a front view of a support plate of an inner stanchion of a pole system according to certain example embodiments.
FIG. 17 is a side view of a base plate of an inner stanchion of a pole system according to certain example embodiments.
FIG. 18 is a front view of a base plate of an inner stanchion of a pole system according to certain example embodiments.
FIG. 19 is a side view of an interlocking disc of an outer stanchion of a pole system according to certain example embodiments.
FIG. 20 is a front view of an interlocking disc of an outer stanchion of a pole system according to certain example embodiments.
FIG. 21 is an end view of a base tube of an inner stanchion of a pole system according to certain example embodiments.
FIG. 22 is a side view of a base tube of an inner stanchion of a pole system according to certain example embodiments.
FIG. 23 is a perspective view of a base tube of an inner stanchion of a pole system according to certain example embodiments.
FIG. 24 is a side view of a connecting rod of an inner stanchion of a pole system according to certain example embodiments.
FIG. 25 is an end view of a connecting rod of an inner stanchion of a pole system according to certain example embodiments.
FIG. 26 is a side view of an outer tube of an outer stanchion of a pole system according to certain example embodiments.
FIG. 27 is an end view of an outer tune of an outer stanchion of a pole system according to certain example embodiments.
FIG. 28 is a perspective view of a base cover of a pole system according to certain example embodiments.
FIG. 29 is a top view of a base cover of a pole system according to certain example embodiments.
FIG. 30 is a side view of a base cover of a pole system according to certain example embodiments.
FIG. 31 is a cross-sectional view of a base cover of a pole system along line A-A in FIG. 30 , according to certain example embodiments.
FIG. 32 is a perspective view of a mounting block of a pole system according to certain example embodiments.
FIG. 33 is a top view of a mounting block of a pole system according to certain example embodiments.
FIG. 34 is a cross-sectional view of a mounting block of a pole system along line A-A in FIG. 33 , according to certain example embodiments.
DETAILED DESCRIPTION
In the following descriptions, the present invention will be explained with reference to various example embodiments. Nevertheless, these example embodiments are not intended to limit the present invention to any specific example, environment, application, or particular implementation described herein. Therefore, descriptions of these example embodiments are only provided for purpose of illustration rather than to limit the present invention. The invention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. Dimensions and proportions of the various components can be varied without departing from the scope of the invention, unless specifically recited as limiting in a given claim.
Referring to FIGS. 1-4 , the pole mounting system 100 generally comprises an inner stanchion 102 , an outer stanchion 104 disposed over the inner stanchion, and a base cover 106 disposed over a base plate 118 of the inner stanchion. A mounting block 108 is disposed inside the top end of the outer stanchion 104 and is bolted to the inner stanchion 102 via an interlocking bolt 110 .
A gap G is defined inside of the outer stanchion 104 between the inner surface of the outer stanchion and the outer surface of the inner stanchion to permit electrical wiring or conduit and other physical wires or conduit in the ground can to extend through the pole mounting system so that the meter mounted atop the pole system can be connected to said conduit or wiring.
Referring now to FIGS. 5-8 , the inner stanchion 102 includes an elongated body 103 with a standoff 105 disposed at a top end thereof. The opposing lower end of the body 102 is secured to a support plate 112 . A receiving disc 114 is disposed atop the support plate 112 . These two components together define a recessed region 109 to receive an interlocking disc 120 of the outer stanchion 104 as will be explained later herein. The support plate 112 is also coupled to a top end of a base tube 116 . The base tube 116 is also secured atop a base plate 118 . The bottom side of the base plate 118 makes contact with the ground.
Referring next to FIGS. 9-12 , the outer stanchion 104 comprises an elongated hollow tubular body 111 with an open top end and an interlocking disc 120 disposed at the bottom end thereof. The interlocking disc 120 is sized and shaped to be disposed in the recessed region 109 and register with the inner circumferential shape of the receiving disc 114 in a plurality of rotational orientations. A mounting block 122 is disposed inside of the outer stanchion 104 adjacent the top end of the body 111 .
Referring to FIGS. 13-14 , the receiving disc 114 of the inner stanchion 102 includes an inner circumference 124 shaped to define multiple fixed rotational orientations about the vertical axis. In the FIG. 14 , the shape is shown to be octagonal, which will provide eight distinct possible orientations about the vertical axis. The inner perimeter shape 124 can be varied (e.g. hexagonal and pentagonal) to provide for more or fewer set points without departing from the scope of the invention. In addition, the shape need not be a uniform polygon, but can be an eccentric shape.
Referring to FIGS. 15-16 the support plate 112 includes a generally flat upper surface 113 for defining a cam surface to support the bottom surface of the interlocking disc 120 of the outer stanchion 104 . A plurality of apertures 126 are defined through the support plate 112 to permit the passage of electrical and network wiring, or other physical connection conduits, through the hollow center of the outer stanchion 104 to a meter disposed atop the outer stanchion 104 .
Referring to FIGS. 17-18 the base plate 118 comprises a generally flat disc body 119 with a centrally located opening 127 through the disc body 119 and a plurality of apertures 128 arrayed around the disc body 119 and extending through the disc body 119 . The apertures 128 are circumferentially elongated to allow bolts or other fastening members or means to extend upward from the concrete slab and protrude upward through the plate apertures 128 , which are then secured in place with respect to the base plate 118 . Thus, the base plate 118 permits some degree of rotational adjustment before being secured rigidly to the ground (e.g. concrete sidewalk) so that it cannot move.
Referring to FIGS. 19-20 , the interlocking disc 120 of the outer stanchion 104 generally comprises a flat disc body 121 with a central opening 130 defined therethrough. The center opening 130 permits passage of the previously noted network and power conduits. The outer perimeter 132 is shaped and sized to interlock with the inner circumference 124 of the receiving disc 114 .
Referring to FIGS. 21-23 , base tube 116 comprises a ring-shaped body having a central opening. The planes of the respective top 123 and bottom ends 125 are parallel to one another.
Referring to FIGS. 24-25 , the connecting rod or elongated body 103 of the inner stanchion 102 comprises an elongated solid body with a circular cross-sectional shape. However, the body could also be made hollow and/or have a non-circular cross-sectional shape (e.g. semi-circular and polygonal). The length of the rod 103 depends on the height above the ground that the meter will be mounted. The width and shape of the body 103 can be varied to accommodate conduit within the outer stanchion 104 .
Referring to FIGS. 26-27 , the body 111 of outer stanchion 104 comprises an elongated hollow tubular shape with a circular cross-section. However, the body 111 could also be formed of a non-circular cross-sectional shape (e.g. semi-circular and polygonal). The length of the body 111 depends on the height above the ground that the meter will be mounted. The width and shape can be varied to accommodate conduit. One or more meter mounting holes 144 can be defined in the body 111 adjacent the upper end of the outer stanchion 104 as shown in FIGS. 1 and 3 for securing the meter in place.
Referring to FIGS. 28-31 , the base cover 106 includes a top aperture 138 sized to permit passage of the outer tube 136 , but not the interlocking disc 120 . The diameter of the aperture 138 is preferably very similar to the outer diameter of the body 111 of the outer stanchion 104 . The cover 106 includes a domed upper surface 129 and recessed bottom surface 131 . The bottom surface defines an enclosed area between the base cover 106 and the base plate 118 when the pole mounting assembly 100 is assembled. Thus, the cover 106 covers over and protects the fasteners used to fasten the base plate 118 to the ground.
Referring to FIGS. 32-34 , the mounting block 108 comprises a rectangular body 133 with a plurality of apertures 140 and 142 defined therein. The block 108 is sized to fit inside of the inner diameter of the outer stanchion 104 and leave gaps between the block body 133 and inner surface of the outer stanchion so that electrical conduit and other connections can pass though to the meter.
The block body 133 includes a central aperture 140 passing through the body from top to bottom. The central aperture 140 is sized to permit passage of the locking bolt 110 through the body 133 . The central aperture 140 also can be shaped to receive a head portion of the locking bolt 110 . First and second parking meter locking apertures 142 a and 142 b are disposed laterally adjacent the central aperture 140 . The meter locking apertures 142 a and 142 b are configured to provide a means to securely couple the meter head to the pole assembly 100 .
A wide variety of parking meters or other mechanical and electrical devices can be mounted to the present pole device or system 100 . The system 100 can be used in any instance where a mechanical or electrical device needs to be secured to the ground and securely mounted at an elevation above the ground while electrical or other conduit passes internally though the outer stanchion.
The various components described herein can be formed from any suitable rigid material, such as metal, fiber glass, plastics, etc. In one example, the parts are formed of steel. The parts can be plated, coated or painted as is known in the art for various functional (e.g. rust protection) and aesthetic reasons.
In use, the inner stanchion 102 is assembled. Any electrical/communications wiring is fed up through the center of the base plate 118 and the base plate 118 is fastened to the concrete (ground). The outer stanchion 104 is disposed over the inner stanchion 102 and the interlocking disc 120 is secured in a given orientation with respect to the inner stanchion 102 . The base cover 106 can be welded to the outer stanchion prior to assembly of the pole system. The cover 106 thus covers the mounting hardware when the outer stanchion 104 is installed. The mounting block 108 is also pre-welded or secured into the top end of the outer stanchion 104 before system assembly. The locking bolt 110 is tightened to lock the outer stanchion 104 in a fixed rotational position about the vertical axis. After the stanchions 102 and 104 are in place, then the meter is disposed over the upper end of the outer stanchion 104 and coupled to the mounting block 108 and the outer stanchion 104 . Note that there are additional mounting holes 144 defined adjacent the upper end of the outer stanchion as shown in FIGS. 1 and 3 for securing the meter in place.
The rotational alignment of the meter about the vertical axis can be adjusted by loosening the stanchion locking bolt 110 enough to back the interlocking disc 120 out of engagement with the receiving disc 114 . Then the outer stanchion 104 can be rotated with respect to the inner stanchion 102 . The locking bolt 110 is then tightened to again secure the outer stanchion in place 104 . The meter is then fastened to the pole assembly 100 as noted above.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiments. It will be readily apparent to those of ordinary skill in the art that many modifications and equivalent arrangements can be made thereof without departing from the spirit and scope of the present disclosure, such scope to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products. Moreover, features or aspects of various example embodiments may be mixed and matched (even if such combination is not explicitly described herein) without departing from the scope of the invention.
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A pole mounting system can be configured as a center drawn mounting system which allows the user to securely mount and adjust the inner stanchion in various rotational orientations about the vertical axis. The system also allows any electrical wiring or other conduit to be run up inside of the pole. Once the inner stanchion is fastened in place, the outer stanchion fits over top with a first disc on the outer stanchion interlocking with a disc recess on the inner stanchion, thereby preventing the outer stanchion from twisting with respect to the inner stanchion. Once a locking bolt is in place, the parking meter is fastened to the top of the outer stanchion. The present system is tamper resistant because the electrical wiring or conduit and the mounting hardware are not externally accessible once installation is completed.
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BACKGROUND
[0001] This disclosure is directed to systems and methods of digital scaling and correction of a plurality of color channels in a multicolor image forming device.
[0002] Printers, copiers, and other types of image forming devices have become necessary productivity tools for producing and/or reproducing documents. Such image forming devices include, but are not limited to, desktop copiers, stand alone copiers, facsimile machines, photographic copiers, laser printers and copiers, and multifunction devices which may comprise one or more of the above devices and other like systems capable of producing, and/or reproducing image data from an original document, data file or the like. During the image reproduction process, it is known in systems such as the ones listed above, to divide a color image into a plurality of images to simplify processing. These plurality of images, when recombined, may reproduce the original image. As is known, an image may be divided into a plurality of images, in accordance with a multicolor color space. Such a color space may define a plurality of colors, that when combined in varying amounts, are able to produce a wider variety and number of colors than the number of the colors in the color space. In this way, a relatively small number of component images, or color channels, where each color channel represents a color image drawn with preferably, but not limited to, one color channel representing one of the plurality of colors defined by a color space, may be provided to reproduce a relatively large number of colors.
[0003] For example, as in known in paper color image reproduction, a color space defined by four component colors, comprising cyan, magenta, yellow and black may be used n order to reproduce full color images. This color space may be referred to as CMYK, and may provide full color reproduction of images. Each full color image may, in turn, be divided into four colors channels, as discussed above, where each color channel may be associated with one of the four colors channels C, M, Y, and K comprising the CMYK color space.
[0004] Because a full color image may be separated into color channels, errors may occur during the reproduction process. Specifically, alignment of all of the color channels must be maintained in order to properly reproduce the image. If color channels are not aligned, a final reproduced color image may appear to have incorrect colors when superimposed, or may cause the “ghosting” of images, where one or more color channels are visibly displaced from other color channels.
SUMMARY
[0005] Related methods of correcting simple errors, specifically with respect to properly scaling a plurality of color channels with respect to each other, include providing circuitry to individually scale each of the plurality of color channels. More specifically, related art methods and systems of achieving the above correction in certain laser printer applications involve applying a unique timing signal to each color channel provided by a plurality of clock signal generating units, where each clock signal generating units provides a different clock signal frequency to its respective color channel scaling and correction unit, in order to compensate for laser characteristics which may van, between lasers in an image forming device. Further, each laser in a laser color image forming device may be operatively assigned to one of a plurality of color channels within a color space.
[0006] In turn, a separate laser may be provided for each color channel to control that color channel individually. However, these lasers may have different performance characteristics, where the different performance characteristics may affect the output of an image in a printing application. These differing characteristics may cause images to improperly align, resulting in an inaccurate reproduction of color image data.
[0007] Providing a timing circuit, such as a phase-locked loop individually to each color channel may offset the inconsistencies between channels, thereby allowing all channels to be properly aligned. However, providing a timing circuit, such as a phase-locked loop, for each of a plurality of color channels may cause electromagnetic interference in a scaling and correction system, as well as increase cost and complexity in components in order to scale and correct an image.
[0008] Therefore, it is desired to provide a system and method for digital scaling and correction of a plurality of color channels which reduces the amount of electromagnetic interference and the amount of timing circuitry. Systems and methods of the current disclosure describe scaling and correction for a plurality of color channels while also providing a single timing circuit.
[0009] A drawback with conventional methods and systems associated with image forming devices is the electromagnetic interference and duplication of timing hardware associated with providing a dedicated timing circuit (with only slightly varying timing parameters) to each and every laser in the image forming device. Additionally, by requiring such an arrangement, an unnecessary duplication of hardware occurs, increasing cost and bulk of hardware required to implement the accurate reproduction of full color images.
[0010] It would be advantageous, in view of the above-identified shortfalls, to provide methods and systems, within or related to one or more image forming devices, that would allow the scaling and correction of a plurality of color channels of color image data, while providing a single timing unit, thereby reducing electromagnetic interference, bulk and cost, among other advantages.
[0011] Additionally, it would be beneficial to provide a plurality of scaling and correction units, each associated with a single channel of color channel data. Each channel of color channel data, as discussed above, may be associated with one of a plurality of color channels in a color space, such as, but not limited to one of C, M, Y, or K channels in a CMYK color space. Each scaling unit, working in conjunction with a single timing clock, may modify color channel data by reading source color channel pixels, which may be digital representations of color channel data provided to the system of an image forming device to cause proper alignment of all color channels. By using a single timing clock, providing a substantially identical timing signal may be provided to each scaling and correction unit.
[0012] In certain embodiments, fractions of pixels, or subpixels, are added or subtracted from a sequence of pixels in a scan direction, such as a horizontal line of color image data, to stretch or shrink a horizontal line of image data. A scan direction may be any scan direction in an image reproduction device which operates in a given dimension or direction, such as, but not limited to a horizontal line. A scan direction may also include curves, splines or other directions or dimensions used in image reproduction as is known, or may be developed in the future. By removing a predetermined number of subpixels from a line that should be contracted, or conversely, adding a predetermined number of subpixels to a line that should be extended, proper alignment of color channel data may be achieved across a scan direction.
[0013] The systems and methods according to this disclosure may distribute these additions or subtractions, or more generally corrections, evenly across the length of a scan direction. To achieve this increased even distribution, each sequence of pixels in a scan direction, or in an exemplary horizontal line of image data, may be divided into a predetermined number of sections, each section being of a substantially equal number of pixels. Once these sections are created, one correction is performed for each section, thereby distributing the potential error, and minimizing visible misalignment that may occur when a large portion of corrections are made within a close distance of each other, causing a highly localized expansion or contraction of image data. In certain embodiments, the actual placement of the correction may be random to prevent visible artifacts.
[0014] The systems and methods according to this disclosure may provide addition or subtraction of subpixels in a sequence of pixels in a scan direction, such as a line of image data. In each sequence of pixels from source color channel data, a first resolution may be expanded to a second higher resolution, or concurrently when an addition or subtraction correction is to be made. This way, in addition to even distribution of corrections as described above, visual inconsistencies may be further reduced by adding or subtracting pixels at a second resolution. Since pixels at a higher resolution are added and subtracted from image data at a first low resolution, the pixels at a higher resolution may in fact be treated as subpixels, or partial pixels at a source resolution.
[0015] The systems and methods according to this disclosure may provide a plurality of scaling and correction units, which may each include a scaling and correction main unit to scale and correct color channel pixels to be properly aligned with color channel pixels of other, associated, color channels of a color space.
[0016] The systems and methods according to this disclosure may also provide a plurality of scaling and correction units, which may each further include a shift register, to convert external signals into a format compatible with signals input to and output from the scaling and correction unit, a section index unit to indicate a section, or subdivision, in a sequence of color channel pixels, a position index unit to indicate a position, or location, within a section, a correction index unit to indicate a position within a section where a correction is to be made, such as an addition correction or a subtraction correction as described, and a compare index unit to indicate that a position corresponds to a position where a correction is required.
[0017] The systems and methods according to this disclosure may provide a single timing clock operatively connected to a plurality of scaling and correction units.
[0018] The systems and methods according to this disclosure may provide a controller interface which may provide input parameters to a plurality of scaling and correction units.
[0019] The systems and methods according to this disclosure may provide a timing unit which may include a scan signal converter unit, to convert scan signals into a format compatible with a plurality of scaling and correction units, a First-In, First-Out (“FIFO”) buffer and a parallel-to-serial converter, to convert source color channel pixels into a format compatible with a plurality of scaling and correction units.
[0020] The systems and methods according to this disclosure may provide a synchronization unit which may include a timing signal generator, parallel output registers, and parallel-to-serial converters, to convert external signals into a format compatible with signals input to and output from the system.
[0021] These and other features and advantages of the disclosed embodiments are described in, or apparent from, the following detailed description of various exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Various exemplary embodiments and disclosed systems and methods will be described, in detail, with reference to the following figures, wherein:
[0023] FIG. 1 illustrates a block diagram of an exemplary system for digital scaling and correction of a plurality of color channels;
[0024] FIG. 2 illustrates a block diagram of a second exemplary system for digital scaling and correction of a plurality of color channels including synchronization and timing units;
[0025] FIG. 3 is a flowchart outlining an exemplary method for implementing digital scaling and correction for a sequence of source pixels representing color channel data; and
[0026] FIG. 4 illustrates a diagram of an exemplary output of a digital scaling and correction system involving addition corrections.
DETAILED DESCRIPTION OF EMBODIMENTS
[0027] The following description of various exemplary embodiments and systems and methods for digital scaling and correction of a plurality of color channels may refer to a plurality of images, each image comprising a different color channel, that when superimposed form an image with a greater number of colors than a sum of the plurality of color channels such as, but not limited to, color spaces used to reproduce full color images. These color spaces may refer to additive color channels, such as, but not limited to, CMYK channels used in the printing of digital images, as are known in the art. However, the subject matter of this disclosure is riot limited to any specific type of color space, any specific number of color channels in a color space, or any other restriction on characteristics of color channels or color spaces as are known or may be known. For example, known color spaces exemplified by, but not limited to, RGB and L*a*b* may be digitally scaled and corrected by the systems and methods of this disclosure.
[0028] Source color channels and source color control signals, as depicted, outlined and/or discussed below, may include, but are not limited to, digital image reproduction and manipulation devices such as digital computing devices, laser printer devices, or the like. The devices receiving scaled and corrected color channel data may also at least comprise devices as exemplified above.
[0029] FIG. 1 illustrates a block diagram of an exemplary system 100 for digital scaling and correction of a plurality of color channels;
[0030] A digital scaling and correction system 100 may accommodate an arbitrary number of source color channel pixels 140 , representing all pixels of a color image, and divided into pixels each associated with a single color channel as described above, to be digitally scaled and corrected. A corresponding number of scaled color channels is generated for each of the source color channels, respectively, after digital scaling and correction. Each source color channel is operatively connected to a scaling and correction unit 110 A, 110 B or 110 C, which generates the scaled and corrected color channels. It should be appreciated that the number of source color channels and their corresponding scaling and correction units may vary based on the number of source color channels provided to the system, which may, in turn, be based on the number of color channels in a source color space.
[0031] In the case that the data of source color channel pixels 140 is synchronous, source color channel synchronization signals may be provided. The signals may comprise, but are not limited to, scan synchronization signals such as horizontal synchronization (“H sync”), as a start of scan signal (“SOS”), such as may be used in printing devices to indicate the beginning of a new line. Additionally, another scan synchronization signal may also be provided, such as a vertical synchronization (“V sync”), as may be used in digital printing devices which may indicate the beginning of a new page.
[0032] The digital scaling and correction system 100 is operable to perform scaling and correction on a plurality of source color channels comprising source color channel pixels 140 by using a single scaling clock generator for each of the plurality of scaling and correction units 110 A, 110 B and 110 C. In certain embodiments, the scaling signal may be modified from an external clock signal at a different, higher frequency by a clock generator such as, for example, a phase-locked loop 120 . In this way, a single phase-locked loop, or the like, may provide properly timed and independent scaling and correction of all scaling and correction units 110 A, 110 B and 110 C.
[0033] In order to successfully realize the scaling and correction of multiple source color channels while using a single substantially identical clock signal for every scaling and correction unit 110 A, 110 B and 110 C, at least one controller interface 130 may provide source color scaling and correction parameters to each scaling and correction unit 110 A, 110 B and 110 C. Each controller interface 130 may provide a plurality of scaling and correction parameters in order to successfully scale and correct a wide range of source color channel data. Exemplary scaling and correction parameters 132 may include, but are not limited to, (1) a parameter to define the number of corrections to be made, (2) a parameter to define the input resolution of source color channel data, (3) a parameter to determine whether a scaling correction will expand or contract a source color channel, and (4) a parameter to determine where an addition or subtraction correction may occur. Additionally, parameters may be added in order to increase functionality of capability of the scaling and correction units associated with each source color channel. Conversely, the controller interface may omit one or more of the parameters discussed above. These omitted parameters may be directly provided by another source or device, or may not be required by an embodiment.
[0034] A digital scaling and correction system 100 may also provide a timing signal clock generator 120 , which may generate a pixel clock frequency or a second clock frequency operating at a different frequency from a scaling unit clock. For example, this pixel clock may be used for timing each scaling and correction unit associated with a source color channel. Additionally, the system may include, but is not limited to, an output buffer for each of the scaled and corrected color channels that are produced by the system, before being output to an external device. Such output buffers may include parallel to serial converters, or vice versa, or the like, and parallel or serial registers, or the like. These buffers may be arranged as is known.
[0035] FIG. 2 illustrates a block diagram of a second exemplary system for digital scaling and correction of a plurality of color channels including synchronization and timing units.
[0036] A second exemplary system for digital scaling and correction may include additional timing and synchronization units. A synchronization unit 200 may include a timing signal generator 202 to generate a second clock frequency from a scaling clock frequency and a start of scan sync signal (“SOS sync”) from an external start of scan signal, which may comprise one of a plurality of source color channel synchronization signals. The synchronization unit 200 may also include parallel output registers 204 to buffer scaled and corrected color channel pixels for each color channel, and parallel to serial converters 206 to convert buffered parallel scaled and corrected color channel pixels into serial scaled and corrected color channel pixels. This synchronization unit 200 may provide common inputs to and outputs from each timing unit 230 and scaling and correction unit 210 in the system. A plurality of scaling and correction unit outputs may be assembled by the synchronization unit 200 for post-processing and output.
[0037] The timing signal generator 202 may generate a second timing signal, such as a pixel clock, and an SOS sync, which may be synchronously coordinated with the pixel clock. The start of scan may indicate, in an exemplary embodiment, a horizontal scan direction synchronization.
[0038] Parallel output registers 204 and parallel to serial converters 206 may provide appropriate output buffering and conversion to a plurality of parallel scaled and corrected color channel pixels. The registers 204 may receive and buffer scaled and corrected color channel pixels to a scaling clock frequency from a pixel clock frequency, using a load signal which may operate at a pixel clock frequency. These buffered pixels are then received and converted by parallel to serial converters into serial scaled and corrected color channel pixels.
[0039] Further, a timing unit 230 may be included for each scaling and correction unit 210 to perform appropriate preprocessing of input signals prior to scaling and correction. The timing unit 230 may include a scan conversion unit 232 to, in exemplary embodiments, generate a page start signal from a vertical sync signal and a line start signal from an SOS sync signal. A vertical sync signal may comprise one of a plurality of source color synchronization signals. Additionally, all of the synchronization signals generated by the timing unit may be substantially coordinated with the pixel clock signal.
[0040] Source color channel pixels 140 may be synchronized and buffered by the timing unit 230 in a similar fashion to output buffering and conversion by the synchronization unit 200 , and may use a source color channel clock, which may itself be one of a plurality of source color synchronization signals. In exemplary embodiments, a FIFO buffer 234 may buffer, for example, parallel source color channel pixels 140 , synchronized to a source color channel clock or system clock, to parallel source color channel pixels synchronized to the pixel clock. These pixels may then be converted to serial source color channel pixels by the parallel to serial converter 236 , and received by the scaling and correction unit 210 .
[0041] A scaling and correction unit 210 may include a scaling and correction main unit 214 , and may further include a shift register 212 for each scaling and correction unit 210 . This shift register 212 may convert exemplary serial scaled and corrected color channel pixels to exemplary parallel scaled and corrected color channel pixels, which may be received by the synchronization unit 200 , prior to output from the system.
[0042] Each scaling and correction unit 210 may be initialized with a plurality of scaling and correction parameters as discussed above, parameters whose characteristics, member, and type may be governed by an external device, or may include the input of a user.
[0043] The values that may be loaded into a position index unit 218 , a section index unit 220 , and a correction index unit 222 , which may be embodied in at least one random number generator, as discussed above, will be described below. In an exemplary embodiment, a position index unit 218 may comprise a counter, a section index unit 220 may comprise an accumulator, and a correction index unit 222 comprising at least one random number generator, may further comprise a single random number generator. An accumulator may be loaded with a seed value, a random number generator may be loaded with a mask value, and a counter may be reset to a predetermined value, which may include a reset to zero.
[0044] A seed value, as may be utilized in this embodiment in order to implement a section index, indirectly determines a length and pixel of each division, or a section of a single sequence of pixels of color channel data, exemplified by a line of color channel data in a fast scan direction. One correction is provided per section in this embodiment to more evenly distribute and mitigate potentially visible errors which may occur during the scaling and correcting process.
[0045] For example, a total number of pixels in a single line or fast scan direction may be 104 pixels long, and may be scaled to 100 pixels long. To accomplish scaling to 100 pixels, four corrections sections may be required to scale the line, where four sections may be provided to perform four subtraction corrections. Therefore, a section length may be 26 pixels long, to provide four sections to a sequence of pixels 104 pixels long. An accumulator may be used to store a section index, and may incorporate a seed value which causes the accumulator to overflow at the end of every section. This overflow may comprise a control signal which may be provided to a counter and a random number generator in an exemplary embodiment, as will be discussed below. Position index unit 218 , as discussed above, is used to store the current position within a section. As each pixel, or set of pixels, is scaled and corrected, the counter may record the number of pixels or sets of pixels that have been scaled and corrected by the system. After initialization, the counter may receive a control signal from the accumulator at the end of a section. This control signal may reset the counter at the beginning of each section, thereby starting a new count for each section.
[0046] The at least one random number generator may be specifically embodied in a single random number generator. This random number generator may generate and provide two signals. First, it may provide a single signal to determine which of a plurality of pixels to be processed simultaneously is to be corrected through a source correction pixel select signal, if more than one pixel is scaled and corrected during a single scaling and correction operation. In this case, because only one correction must occur, even though a plurality of pixels are being processed, one pixel of the plurality of pixels may be chosen for correction. For example, for two source color channel pixels processed during one scaling and correction operation, a random number generator may provide a one bit signal to determine which of the two pixels should be corrected. It is to be understood that if more than two pixels are processed during a signal scaling and correction operation, the random number generator may provide a source correction pixel select signal of the appropriate number of bits in order to determine which of a greater plurality of pixels is to be corrected, as is known.
[0047] The random number generator of an exemplary embodiment also provides a second signal which is used to determine the location of a correction along the length of a section. During initialization, an exemplary random number generator may be loaded with a mask value, which may denote the maximum bound of the section or other bound on the random number to be generated. The random number generator may receive a control signal, such as, but not limited to, an overflow as discussed above, from the accumulator of an exemplary embodiment of a section index unit at the end of a section. Upon receiving this control signal, the generator may, among other operations, increment its value, in order to provide a different index for a subsequent section. It is to be understood that a number of methods or operations may be provided in order to change the value contained in a random number generator, or any correction index unit.
[0048] Once each of the section index unit 220 , correction index unit 222 , and position index unit 218 have been initialized, serial color channel pixels for a single color channel may be scaled and corrected. The scaling and correcting of a single color channel may occur in substantial coordination with scaling and correcting of other color channels employing a substantially identical method.
[0049] Further, during the execution of this method, a fast scan signal or a slow scan signal, as discussed above, may be provided to delineate the spatial orientation of pixels in a color channel. For example, a fast scan signal may indicate the beginning of a line of printer image data, and a slow scan signal may delineate the beginning of a new page or image of printer image data. It is to be appreciated that source color synchronization signals though exemplified by a fast scan and slow scan signal may comprise any signal or group of signals which may define dimensional characteristics of source color channel data, as is known, or may be known.
[0050] If a fast scan signal or slow scan signal is received during the method, a scaling and correction unit may be instructed in an exemplary embodiments, to at least indicate the start of a new line, or new page, respectively.
[0051] In an exemplary embodiment, two pixels of source color channel image data are read during a single scaling and correction operation.
[0052] A determination is made as to which of the source color channel pixels are to be corrected, if a correction operation is to be made. This determination may be made by a correction index unit 222 , embodied in a random number generator, portion of a random number generator, or other means.
[0053] A scaling operation is performed which may convert pixels of color channel data at a first source resolution to color channel data at a second scaled resolution. Again, color channel scaling and correction parameters may provide source color channel resolution information, and scaled color channel resolution information. From this resolution information, the scaling and correction unit may convert source color channel pixels at a source resolution to color channel pixels at a scaled resolution. In an exemplary embodiment, a source color channel resolution may be 1200 spots per inch, 2400 spots per inch, or 600 spots per inch. Additionally, a scaled resolution may include 9600 spots per inch. A scaling and correction unit may read two color channel pixels at 2400 spots per inch and scale them to eight color channel pixels at 9600 spots per inch, effectively quadrupling the resolution of the color channels pixels. Each source color channel pixel is now represented by four scaled source color channel pixels, for a total of eight scaled color channel pixels produced from two source color channel pixels.
[0054] For a correction operation, the scaling and correction unit may read a modification pixel signal from a compare index unit 216 . The compare index unit 216 may, in exemplary embodiments, be a comparator or the like. The modification pixel signal may be a single bit which indicates whether or not a correction operation is to occur for the currently scaled color channel pixels. The compare index unit 216 reads a position index from a position index unit 218 and a correction index from a correction index unit 222 , and may instruct a scaling and correction unit to perform a correction if the indices contained in the position index unit and correction index unit are substantially equal, via the modification pixel signal. If the compare index unit 216 indicates that the indices are not substantially equal, the scaling and correction unit 210 may output the scaled pixels to a buffer, external logic unit or units, or other device or means. If the compare index unit 216 indicates that the indices are substantially equal, the scaling and connection unit 210 may perform a correction, as discussed below.
[0055] The digital scaling and correction unit may read a number of source color scaling and correction parameters. Specifically, in an exemplary embodiment, the digital scaling and correction unit may read an addition/subtraction signal and a modification pixel signal. An addition/subtraction pixel signal may include a single bit which indicates whether or not a correction involves removing a single scaled pixel from a sequence of scaled color channel pixels, thereby contracting the scaled color channel pixels. Conversely, the addition/subtraction pixel signal may indicate that at least a single scaled color channel pixel is to be added to the sequence of scaled color channel pixels, resulting in an expanded scaled color channel pixel sequence.
[0056] Further, the correction pixel signal may indicate which of the source color channel pixels, before scaling, should be corrected by either the addition or subtraction of a scaled color channel pixel. For example, two source color channel pixels at 2400 spots per inch, converted to scaled color channel pixels at 9600 spots per inch, as discussed above, may be corrected on the first pixel or the second pixel. Specifically, if an addition correction is to occur on the first pixel, the scaling and correction unit may generate a sequence of five of the first scaled color channel pixels, followed by a sequence of four of the second scaled color channel pixels. This way, a resulting scaled and corrected sequence of color channel pixels would be nine pixels long. In addition, correction on the second pixel in the sequence of scaled color channel pixels, would result in a sequence of four of the first source color channel pixels followed by five of the second scaled color channel pixels.
[0057] A subtraction correction is executed in a similar fashion to an addition correction. In the case that a subtraction correction is performed on the first pixel of source color channel pixels at 2400 spots per inch, converted to scaled color channel pixels at 9600 spots per inch, a scaled and corrected sequence of color channel pixels would include three of the first color channel pixels, followed by four of the second color channel pixels, for a total of seven scaled color channel pixels. Similarly, a subtraction correction performed on the second source color channel pixels would result in four of the first scaled color channel pixels followed by three of the second scaled color channel pixels, again for a total of seven scaled and corrected color channel pixels.
[0058] In order to more fully illustrate addition and subtraction corrections as discussed above, an example is provided in FIG. 4 .
[0059] FIG. 3 is a flowchart outlining an exemplary method for implementing digital scaling and correction for a sequence of source pixels representing color channel data.
[0060] At step S 300 , a method for implementing digital scaling and correction for a sequence of source pixels representing color channel data begins.
[0061] A system may be initialized with parameters which may be provided by a controller interface. A controller interface 130 , or another external signal, or collection of signals, may describe the parameters for scaling and correcting a particular color channel of a plurality of color channels 140 to be aligned with other color channels 140 , when superimposed, in order to form a color image, as discussed above. The initialization of system parameters may occur in any order, and may comprise, in exemplary embodiments, the loading of an accumulator, the loading of a random number generator, the resetting of a counter, and the determination of an input resolution.
[0062] At step S 310 , a determination may be made whether pixels are available in the source color channel data for processing. If no pixels are available, the scaling and correction of all source color channel data may be complete at step S 314 , and the process may end at step S 380 . It is to be understood that other conditions, automatic, or user-initiated, from internal or external sources, may also trigger the end of a process. It is to be further understood that a digital scaling and correction process may be terminated at any point during process flow, by, for example, an abort interrupt, and is not limited to any particular position in a process. If pixels are available at step S 312 , the process will continue to step S 320 .
[0063] At step S 320 , a determination may be made by the system whether a new fast scan or slow scan begins, exemplified by, but not limited to a new page or a new line, respectively. A new page or line may be determined at S 322 , for example, by external logic interrupts or logic units, internal or external, which provides source color channel data signals. If a new section, line, page, or other division is not determined to be required at S 324 , the method continues to step S 340 . However, if such a division is required at step S 322 , such parameters may be indicated or set, or handled at step S 330 . For example, if the beginning of a new section is determined at step S 324 , at least the position index and the correction index may be modified. The method may then continue to step S 340 . If page or line start signals are delivered using interrupts, they may be delivered at substantially any time during the method, and are not necessarily restricted to step S 320 . An interrupt indicating the beginning of a new page or line delivered in this way may return the process to the end of step S 320 . If an interrupt is received, for example, after the completion of step S 360 , process control may return to step S 320 where a new line or page may be set. Therefore, pixel orientation may be more finely controlled.
[0064] A sequence of pixels representing source color channel data may be input into digital scaling and correction system. The sequence of pixels may represent image data divided into, for example, lines and pages, and may also be read as an unbroken sequence of pixels.
[0065] A pixel or group of pixels from a sequence of pixels representing color channel data for a single color channel are read into a scaling and correction unit. During this step, an arbitrary number of pixels may be read into a scaling and correction unit for simultaneous processing, but may comprise fewer pixels than the number of pixels comprising the entire sequence of pixels representing the color channel. Because all of these pixels are processed simultaneously, only one correction may be performed during the simultaneous processing of the pixels at step S 340 .
[0066] A source correction pixel may be chosen from the pixel or pixels read into the scaling and correction unit. The pixel chosen may be designated as the pixel where a correction operation may occur, should a correction operation be selected for the current pixels or pixels being processed. If a correction is to occur, correction at the position of the chosen pixel using the color characteristics of the chosen pixel may occur. It is to be understood that a source pixel may be chosen at any other point during the method before correction occurs.
[0067] The source pixel or pixels may further be scaled to a second resolution. In exemplary embodiments, source pixels may be scaled from a lower resolution to a higher resolution by repeating pixels. For example, if two source pixels are read at 2400 spots per inch, and are expanded to 9600 spots per inch, a first source pixel will be duplicated four times and will be followed by four duplicates of the second source pixels. This way, eight scaled pixels at a second resolution are generated, where the first four scaled pixels have substantially identical color characteristics to the first source pixel and the second four scaled pixels have substantially identical color characteristics to the second source pixel.
[0068] At step S 340 , a correction determination is made as to whether a correction is to occur for t&e current pixel or pixels. A correction determination S 340 may, in exemplary embodiments, comprise a comparison by the compare index unit 216 between a position index stored in a position index unit 218 and a correction index stored in a correction index unit 222 . If a compare index unit 216 determines that a position index and a correction index are substantially equal, a compare index unit 216 may output a modification pixel signal to a scaling and correction main unit 214 , instructing the scaling and correction main unit 214 to perform a correction in addition to scaling, at step S 342 . If no correction is to be made to the pixel or pixels at step S 344 , the scaling and correction of the pixel or pixels is complete at S 344 . At step S 344 , once scaling and correction is complete, the method may return to step S 310 .
[0069] At step S 350 , once a correction determination for a correction is made at step S 342 , an addition or subtraction correction determination is made, either to add a scaled pixel at S 352 , or to subtract a scaled pixel at S 354 .
[0070] At step S 360 , an addition correction is performed using the selected correction source pixel. A scaled pixel with substantially identical color characteristics to the correction source pixel is added adjacent to the scaled pixels created from the correction source pixel, effectively lengthening the scaled pixels by one scaled pixel. After the addition correction is complete, process flow may continue to the end of scaling and correction of the pixel or pixels, at step S 310 .
[0071] At step S 370 , a subtraction correction is performed using the selected correction source pixel. A scaled pixel from among to the scaled pixels created from the correction source pixel may be removed, effectively shortening the scaled pixels by one scaled pixel. After the addition correction is complete, process flow may continue to the end of scaling and correction of the pixel or pixels, at step S 310 .
[0072] Once the subset of pixels have been processed during scaling and correction, the pixels may be output to external logic unit or units for further processing or display. As discussed above, further processing may include, in exemplary embodiments, buffering or parallel to serial conversion.
[0073] At least the position index stored in a position index unit 218 arid section index stored in a section index unit 220 may be updated, to indicate at least the position index of a subsequent pixel or plurality of pixels to be scaled and corrected. Additionally, the section index may be updated, and such an update may include a control signal indicate whether or not a new section is to begin. For example, a section index unit 220 may comprise an accumulator, and each update may comprise adding a value to the section index accumulator. When a value is added to the section index accumulator which causes an overflow, the overflow may indicate the beginning of a new section.
[0074] Indices may be updated in accordance with the start of a new section. In exemplary embodiments, a position index may be reset to zero, indicating a new measurement from the start of a new section. Additionally, the correction index may be updated to set a different index from the index used in a previous section, to further randomize distribution of errors. The update of a correction index may include, but is not limited to, an increment or decrement of a correction index, or the random generation of all or part of a correction index, based on random number generator input parameters as are known, or may be known.
[0075] FIG. 4 illustrates a diagram of an exemplary output of a digital scaling and correction system involving addition corrections.
[0076] An exemplary output of a digital scaling and correction system 600 is provided. This exemplary output shows the output characteristics of scaling and correction of source color channel pixels in a single scan direction. In this example, a single scan direction may include a single line of printer data output for a single color channel.
[0077] An input scan line 610 comprising a sequence of 28,800 pixels at 2400 spots per inch is to be corrected to an output scan line 620 comprising a sequence of 28,801 pixels at 2400 spots per inch (“spi”). At 2400 spots per inch, 28,800 pixels equal substantially twelve inches. A determination is made externally that a correction should comprise an output correction of one extra pixel at 2400 spots per inch 660 . In this example, a scaling and correction system may scale pixels at 2400 spots per inch to pixels at 9600 spots per inch. Though the internal scaling of pixels may change, the output characteristics of the image will not be substantially different, due to the duplication of pixels to preserve output size, as discussed above.
[0078] With a scaled resolution of 9600 spots per inch, a single addition correction at 2400 spi must be expanded to four addition corrections at 9600 spi, where 4 9600 spi correction pixels=(1 2400 spi correction pixel)*(4 9600 spi pixels/1 2400 spi pixel) 670 . Since a single pixel at 2400 spi has been divided into four pixels at 9600 spi, the addition of a single pixel may be distributed across substantially the entire scan line.
[0079] Since once correction occurs in each section of a scan line, as discussed above, four sections must be provided in order to execute the required number of corrections. In this exemplary embodiment, a section index unit 210 is embodied by an accumulator which loads a seed value. This seed value may be added to itself in the accumulator during the scaling and correction of each pixel or set of pixels. Here, two pixels are read during each scaling and correction operation. An accumulator is provided that may return information in decimal form, and may overflow on reaching a value of 1. A fractional value may be retained in the accumulator during the following accumulator addition of the seed value 5410 . In this case, the accumulator seed value 680 required to create four sections, and therefore execute the required four corrections, is 0.000278, where the seed value may be 0.000278=(4 corrections)/([(28,800 source pixels)*(2 pixels per scaling and correction operation)]. It is notable that the accumulator seed value determination also includes a division by the number of pixels simultaneously processed by the scaling and correction unit. Once scaling and correction begins at the start of a line 630 , each overflow of the accumulator will determine the edge of a new section 640 A, 640 B, 640 C, and 640 D, beginning at 7200 pixels, 14,400 pixels, 21,600 pixels, and 28,800 pixels from the beginning of a line at 2400 spi, respectively.
[0080] Additionally, an exemplary correction index unit 220 , in this case a random number generator, may be programmed with a mask value which determines the allowed range of a correction within a section. In this case, a mask may be programmed at element 690 with a twelve-bit number, allowing a 4096 pixel range, where 2̂12=4096. It is notable that in this case, the length in pixels of a region where a correction may occur, 4096 pixels from the beginning of a section, is smaller than the length in pixels of a section, 7200 pixels from the beginning of the previous section.
[0081] Once these parameters have been defined, a scaling and correction process for a line of source color channel data may begin as shown in, but not limited to, the above example. Further, the above example may be repeated for a plurality of lines comprising a page, and still further for a plurality of such pages, as discussed above.
[0082] It is to be appreciated that, even though the above example includes a source resolution of 2400 spots per inch, the scaling and correction unit may receive source color channel pixels of any predetermined desired resolution, including 600 spots per inch and 1200 spots per inch.
[0083] It is also to be appreciated that even though the above example scales pixels to 9600 spots per inch, the scaling and correction unit may produce scaled color channel pixels at any predetermined desired resolution.
[0084] It is further to be appreciated that even though the above example includes two source color channel pixels to be read during a single scaling and correction operation, and a choice among the two color channel pixels for correction is made, the scaling and correction unit may read any number of predetermined desired source color channel pixels, and choose from among any number of predetermined desired source color channel pixels 5332 .
[0085] Now the digital scaling and correction system 5000 may output a scaled sequence of color channel pixels 5132 , or if a correction is required, a scaled and corrected sequence of color channel pixels 5132 . These scaled, or scaled and corrected, sequences of color channel pixels may be combined with other sequences of color channel pixels, as discussed above.
[0086] It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof; may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, and are also intended to be encompassed by the following claims.
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A system and method are provided for digital correction of a plurality of color channels and color image data. In color reproduction, a color image may be composed of a plurality of superimposed color channels in a color space hi order to assure the proper alignment of color channels and exemplary applications such as color printing, one or more of the plurality of color channels which compose a complete color image may be scaled to an output resolution, and corrected in order to ensure proper alignment and authentic reproduction of a color image. In place of a plurality of independent clocks, one for each channel, a single clock is provided for every channel, and additional unit is supplied to scale each channel according to independent characteristics.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/728,152, filed on Jun. 2, 2015, entitled SYSTEM AND METHOD OF BLUETOOTH PAIRING WITH A GROUP OF BLUETOOTH DEVICES, which claims the benefit of U.S. Provisional Application No. 62/008,825, filed on Jun. 6, 2014, entitled SYSTEM AND METHOD OF BLUETOOTH PAIRING WITH A GROUP OF BLUETOOTH DEVICES, the specifications of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to Bluetooth systems and devices.
SUMMARY
[0003] A method for pairing a first Bluetooth device with an individual Bluetooth device address with a group of Bluetooth devices, said method comprising: assigning a group Bluetooth device address to each of said group of Bluetooth devices; the first Bluetooth device exchanging Bluetooth device addresses with a second Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said second Bluetooth device; establishing, by the first Bluetooth device and the second Bluetooth device, a link key; storing, by the first Bluetooth device, the group Bluetooth device address and the link key; the first Bluetooth device exchanging Bluetooth device addresses with a third Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said third Bluetooth device; recognizing, by the first Bluetooth device, the group Bluetooth device address assigned to the third Bluetooth device; and establishing a communications channel between said first Bluetooth device and said third Bluetooth device based on said link key.
[0004] A system for a first Bluetooth device with an individual Bluetooth device address to communicate with a group of Bluetooth devices, said system comprising: each of said group of Bluetooth devices having the same group Bluetooth device address; the first Bluetooth device exchanging Bluetooth device addresses with a second Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said second Bluetooth device; the first Bluetooth device and the second Bluetooth device establishing a link key, wherein said link key is stored by the first Bluetooth device; the first Bluetooth device exchanging Bluetooth device addresses with a third Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said third Bluetooth device; the first Bluetooth device recognizing the group Bluetooth device address assigned to the third Bluetooth device; and the first Bluetooth device establishing a communications channel with the third Bluetooth device based on said link key.
[0005] The foregoing and additional aspects and embodiments of the present disclosure will be apparent to those of ordinary skill in the art in view of the detailed description of various embodiments and/or aspects, which is made with reference to the drawings, a brief description of which is provided next.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
[0007] FIG. 1 shows a Bluetooth device 100 and a group of Bluetooth devices 200 ;
[0008] FIG. 2A shows a device 100 pairing with device 201 of group 200 within a distributed embodiment;
[0009] FIG. 2B shows device 100 sharing a link key 300 with device 202 of group 200 after recognizing the BD_ADDR of device 202 within the distributed embodiment;
[0010] FIG. 2C is a flowchart of the operation of the distributed embodiment demonstrated in FIGS. 2A and 2B ;
[0011] FIG. 3A shows a device 100 pairing with device 201 of group 200 within a centralized embodiment;
[0012] FIG. 3B shows a device 202 sharing link key 301 with device 100 within a centralized embodiment; and
[0013] FIG. 3C is a flowchart of the operation of the centralized embodiment demonstrated in FIGS. 3A and 3B .
[0014] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments or implementations have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of an invention as defined by the appended claims.
DETAILED DESCRIPTION
[0015] Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a system and method of bluetooth pairing with a group of bluetooth devices are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.
[0016] The Bluetooth protocol is a personal area networking (PAN) protocol designed to allow Bluetooth-enabled devices or Bluetooth devices to communicate with each other within a confined area. For example, a Bluetooth enabled headset can communicate with a Bluetooth enabled mobile phone. For two devices to communicate using the Bluetooth protocol, the devices must first be “paired”.
[0017] During the pairing process, the two devices establish a shared secret known as a link key. After the pairing process, the devices can optionally store the link key so that the pairing process is not required afterwards. Then the devices can “bond” whenever they are close enough, that is, the devices can automatically establish a connection whenever they are close enough. Pairing may also require an authentication process where a user must validate the connection between the two Bluetooth devices.
[0018] If either or both of the paired devices remove the link key, the devices are no longer paired and can therefore no longer bond. The pairing process must be repeated to establish a new link key for the next communication.
[0019] Normally, each Bluetooth device has a 6 -byte device address called BD_ADDR (which stands for Bluetooth Device Address) that uniquely identifies the device. When two devices are brought within wireless communication range, the two devices will exchange their BD_ADDR to see if they are already paired. If the BD_ADDR is recognized and a stored link key is available, the two devices can use the link key to bond, that is, they will re-establish the Bluetooth communication channel without the need to go through the pairing process.
[0020] In some Bluetooth devices, the pairing process requires human intervention. For example, in mobile phones with Bluetooth capabilities, the mobile operating system (OS) may prompt the user for confirmation and authentication. Depending on the OS implementation, this behavior may not be disabled.
[0021] With the growth in popularity of the Bluetooth protocol, there is an increasing need for a Bluetooth device to communicate with multiple Bluetooth devices. Therefore the number of pairing operations required also begins to grow. This can become inconvenient for users, leading to increased frustration with the Bluetooth protocol on the part of the users. This is especially burdensome on a user, if each pairing operation requires authentication as well.
[0022] For example, in one embodiment, in a shopping mall, multiple Bluetooth devices known as Bluetooth beacons that interact with Bluetooth mobile phones are present. These Bluetooth beacons are used for a variety of purposes including geofencing, microlocation and information broadcasting.
[0023] In one embodiment, these Bluetooth beacons are implemented using Bluetooth Low Energy (BLE) technology. The advantage of BLE is in its lower power consumption. Furthermore, in BLE, in one embodiment, pairing is implemented using a mode called Just-Work where no confirmation is required from the user. In BLE broadcast mode, no pairing is required. However BLE offers a limited data rate and is therefore not useful for data traffic.
[0024] In another embodiment, these Bluetooth beacons are implemented using the Classic Bluetooth protocol. The Classic Bluetooth protocol allows for a higher data rate but consumes more power in doing so.
[0025] In such a situation, requiring a user or shopper to have to pair their device with a beacon each time would be inconvenient and annoying to the user/shopper, especially if each time the user/shopper is required to authenticate the pairing.
[0026] The method and system presented in the rest of the specification aims to overcome this problem. The method and system allows a Bluetooth device to pair with a group of Bluetooth devices and only requires pairing with any one of the devices in that group. In one embodiment, the devices operate in classic Bluetooth mode. In a further embodiment, the devices also have an alternative communication channel to communicate the link key. The alternative communication channel does not require explicit pairing. In another embodiment, this alternative channel is a BLE operating in Just-Work pairing mode.
[0027] In one embodiment, this is achieved using the following: Instead of having a unique BD_ADDR for each of the devices in the group, the whole group shares the same BD_ADDR. Thus, the pairing is a pairing between the mobile device and the group.
[0028] An example is shown in FIG. 1 . In FIG. 1 , beacon devices 201 and 202 are part of group 200 . All the devices in group 200 are assigned the same group BD_ADDR. Bluetooth device 100 has not yet been paired with any of the devices in group 200 . In one embodiment, at least some or all of the devices which are part of group 200 are connected to each other via a separate interconnection network such as interconnection network 111 . This interconnection network 111 is, for example, a wireless network, a local area network, an optical network or any appropriate type of network known to one of skill in the art.
[0029] In one embodiment, the sharing of the group BD_ADDR and link key is performed using a distributed embodiment. FIGS. 2A-2C demonstrate operation of the distributed embodiment. In FIG. 2A , when the device 100 comes within the communication range of device 201 of the group, a pairing process starts. The device 100 does not recognize the BD_ADDR of the device 201 , which is the group BD_ADDR of group 200 , and the user of the device 100 is prompted to accept the connection. The connection is performed using classic Bluetooth. Devices 100 and 201 exchange their BD_ADDR and establish a shared link key 300 (step 311 of FIG. 2C ). Device 100 stores the BD_ADDR of device 201 and the associated link key 300 in its memory (step 312 of FIG. 2C ).
[0030] In FIG. 2B , when the device 100 comes within the communication range of device 202 of the same group 200 , it exchanges BD_ADDR with device 202 . Device 100 recognizes the BD_ADDR of device 202 , because device 202 has the same group BD_ADDR as the device 201 (step 313 of FIG. 2C ). At this point, device 100 transmits the shared link key 300 to the device 202 , and device 100 and device 202 establish communications (step 314 of FIG. 2C ).
[0031] In one embodiment, device 100 shares link key 300 with device 202 over an alternative BLE communication channel. In another embodiment, device 100 shares link key 300 using near field communications (NFC). In another embodiment, device 100 shares link key 300 with device 202 using Wi-Fi. Once the device 202 knows the shared link key 300 , it establishes a classic Bluetooth mode communication channel with the device 100 .
[0032] In the whole process above, the devices in the group can operate in a distributed manner without the need of a centralized server or moderator. In an alternative embodiment, all the devices are connected together via the interconnection network and there is a centralized server or moderator connected to the devices via the interconnection network. The devices communicate with the centralized server via the interconnection network.
[0033] FIGS. 3A-3C shows an alternative embodiment using a centralized server or moderator. In FIG. 3A , the beacon devices within the group 200 are connected to a centralized server 400 via the interconnection network 111 . In one embodiment, the centralized server further comprises a centralized database. In another embodiment, the centralized server is separate from the centralized database, but still connected to the centralized database. As before, device 100 and device 201 establish a link key 301 at the beginning via a pairing process (step 401 of FIG. 3C ). Device 100 stores the link key 301 locally (step 402 of FIG. 3C ). Device 201 sends link key 301 to the centralized server 400 , which then stores link key 301 in the centralized database indexed by the BD_ADDR of device 100 . (step 403 of FIG. 3C )
[0034] In FIG. 3B , when the device 100 approaches device 202 , device 202 exchanges BD_ADDR with device 100 . Device 100 recognizes the BD_ADDR of device 202 , and communicates to device 202 that it recognizes the BD_ADDR of device 202 since it is the same as the BD_ADDR of device 201 (step 404 of FIG. 3C ). Then device 202 looks up the BD ADDR of device 100 in the centralized database and retrieves link key 301 from the centralized database. (step 405 of FIG. 3C ) This way, the device 100 and the device 202 have the same link key 301 and no pairing is required. (step 406 of FIG. 3C ) The centralized mode offers advantages over the distributed mode. In the distributed mode, there is a requirement for an alternative channel using a technology such as BLE. However, in the centralized mode this alternative channel is not required. Therefore a mobile device which does not have BLE capability can also use this scheme. Also, having a centralized mode offers the possibility of a more complicated authentication scheme. In one embodiment, the centralized server causes the link key 301 to expire after a fixed period, for example, one day, one week or one month.
[0035] In a further embodiment, both distributed and centralized modes are used. This is useful in a situation where there are many users of devices sharing link keys with the devices in group 200 , or if the interconnection network to the centralized server is slow or unavailable. Then, using only centralized mode could excessively burden the centralized server. In this embodiment, the devices within group 200 will communicate with the centralized server to retrieve the link key. However if, for example, the centralized server is excessively overloaded, or the interconnection network with the centralized server is excessively overloaded, then each of the devices within group 200 will communicate with the user device to share link keys.
[0036] The devices in group 200 can all be located together in one location or geographically distributed over various locations. In one embodiment the devices in group 200 are spread out over two or more locations. This is useful if, for example, all the devices in group 200 are provided by one service provider operating in two or more locations.
[0037] In a further embodiment, if more link security is required to share the key using the alternative channel, the security can be provided in the application layer.
[0038] Although the algorithms described above including those with reference to the foregoing flow charts have been described separately, it should be understood that any two or more of the algorithms disclosed herein can be combined in any combination. Any of the methods, algorithms, implementations, or procedures described herein can include machine-readable instructions for execution by: (a) a processor, (b) a controller, and/or (c) any other suitable processing device. Any algorithm, software, or method disclosed herein can be embodied in software stored on a non-transitory tangible medium such as, for example, a flash memory, a CD-ROM, a floppy disk, a hard drive, a digital versatile disk (DVD), or other memory devices, but persons of ordinary skill in the art will readily appreciate that the entire algorithm and/or parts thereof could alternatively be executed by a device other than a controller and/or embodied in firmware or dedicated hardware in a well known manner (e.g., it may be implemented by an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable logic device (FPLD), discrete logic, etc.). Also, some or all of the machine-readable instructions represented in any flowchart depicted herein can be implemented manually as opposed to automatically by a controller, processor, or similar computing device or machine. Further, although specific algorithms are described with reference to flowcharts depicted herein, persons of ordinary skill in the art will readily appreciate that many other methods of implementing the example machine readable instructions may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined.
[0039] It should be noted that the algorithms illustrated and discussed herein as having various modules which perform particular functions and interact with one another. It should be understood that these modules are merely segregated based on their function for the sake of description and represent computer hardware and/or executable software code which is stored on a computer-readable medium for execution on appropriate computing hardware. The various functions of the different modules and units can be combined or segregated as hardware and/or software stored on a non-transitory computer-readable medium as above as modules in any manner, and can be used separately or in combination.
[0040] While particular implementations and applications of the present disclosure have been illustrated and described, it is to be understood that the present disclosure is not limited to the precise construction and compositions disclosed herein and that various modifications, changes, and variations can be apparent from the foregoing descriptions without departing from the spirit and scope of an invention as defined in the appended claims.
[0041] It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.
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A method for pairing a first Bluetooth device with an individual Bluetooth device address with a group of Bluetooth devices, said method comprising: assigning a group Bluetooth device address to each of said group of Bluetooth devices; the first Bluetooth device exchanging Bluetooth device addresses with a second Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said second Bluetooth device; establishing a link key; storing the group Bluetooth device address and the link key; the first Bluetooth device exchanging Bluetooth device addresses with a third Bluetooth device from said group of Bluetooth devices when said first Bluetooth device comes within communication range of said third Bluetooth device; recognizing the group Bluetooth device address assigned to the third Bluetooth device; and establishing a communications channel between said first Bluetooth device and said third Bluetooth device based on said link key.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to vehicular lamp design, and specifically to a direct lighting vehicular lamp potentially permitting complex styling and ease of manufacturability.
[0003] 2. Related Art
[0004] Lamps (“direct lighting lamps”) frequently use lighting elements which face a zone sought to be lighted, and thus directly illuminate the zone. For example, light-emitting diodes (LED) may be used in vehicular lamps such as brake and tail lamps to directly illuminate a zone of interest lying in front of (facing) the LEDs. The direct lighting lamps differ from the indirect lighting lamps in that the indirect lighting lamps use reflecting surfaces (e.g., aluminum coated cones) to direct the beam to the zone in front (and thus do not face the zone sought to be lighted).
[0005] Direct lighting lamps generally contain directing elements (such as spherical/cylindrical convex lenses) to direct the light output (from the light sources such as LEDs) to obtain desired illumination intensities in desired zones, while also typically giving a more uniform appearance.
[0006] In a prior approach, lens used for directing the light output in a direct lighting vehicular lamp are constructed on an inner surface of the lamp enclosure. Such an approach may, however, constrain the designer to using less complex shapes (profiles) for the lamp enclosure, so that manufacturing of the lamp enclosure is maintained simple/feasible. Consequently, such an approach may not facilitate provision of desired stylistic/aesthetic features in the lamp enclosure.
[0007] Thus, what is required is direct lighting vehicular lamp that provides considerable freedom to the designer and user in choosing the stylistic aspects (such as size and profile of the lamp enclosure) of the overall design. It may be further desirable that such a feature be provided while ensuring that the processes involved in manufacturing the lamp enclosure and various components/sub-assemblies of the lamp are maintained simple.
[0008] Accordingly, the present invention provides a design for a direct lighting vehicular lamp that permits incorporating complex styling for the lamp, and ease of manufacturability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be described with reference to the accompanying drawings, which are described below briefly.
[0010] FIGS. 1A, 1B and 1 C are diagrams showing a 3D (three-dimensional) sectional view, a 3D view and a sectional view respectively from different angles of an example embodiment of a direct lighting vehicular lamp that uses an LED array as the lighting elements, according to an aspect of the present invention.
[0011] FIGS. 2A, 2B and 2 C are diagrams showing sectional views from different angles of the example embodiment shown in FIGS. 1A-1C . FIG. 2D is a diagram showing the top view of the example embodiment shown in FIGS. 1A-1C .
[0012] FIG. 3 is a diagram showing an exploded view of the example embodiment shown in FIGS. 1 A- 1 C/ 2 A- 2 D, with the various components/sub-assemblies being shown separately.
[0013] FIG. 4 is a diagram showing a 3 D view of the inner lens assembly used in the example embodiment of FIGS. 1 A- 1 C/ 2 A- 2 D.
[0014] FIG. 5 is a diagram illustrating the need for using directing elements in a direct lighting vehicular lamp.
[0015] In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit (s) in the corresponding reference number.
DETAILED DESCRIPTION
[0000] 1. Overview
[0016] A direct lighting vehicular lamp provided according to an aspect of the present invention contains a lens assembly and a lamp enclosure provided as physically separate components. The lens assembly may contain multiple lenses directing the light output from one or more lighting elements, and the lamp enclosure covers the inner components (lens assembly and LEDs).
[0017] Since the lamp enclosure is provided as a physically separate component from the lens assembly, the lamp enclosure can be designed to meet any desired specification, for example, to meet aesthetic/stylistic requirements.
[0018] According to another aspect of the present invention, the lenses constructed on the inner lens assembly are cylindrical lenses. This allows greater tolerances to be provided to the mounting positions of the lighting elements on a corresponding mounting sub-assembly such as a printed circuit board (PCB).
[0019] Several aspects of the invention are described below with reference to examples for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details, or with other methods, etc. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention.
[0000] 2. Vehicular Lamp
[0020] FIGS. 1A, 1B and 1 C are diagrams showing a 3D (three-dimensional) sectional view, a 3D view and a sectional view respectively from different angles of an example embodiment of a direct lighting vehicular lamp that uses an LED array as the lighting elements, according to an aspect of the present invention. Each diagram in FIGS. 1A-1C is shown containing lamp enclosure 110 , inner lens assembly 115 , printed circuit board (PCB) sub-assembly 130 and casing 125 . Each Figure contains additional components, as suited in the corresponding view. While the following sections are described with respect to a direct lighting vehicular lamp that uses multiple LEDs as lighting elements, other lighting elements can also be used. Each component is described in further detail below.
[0021] Inner lens assembly 115 contains the lenses used for directing the light output from LEDs (example LEDs 120 and 121 , shown in FIG. 1C ) mounted on PCB sub-assembly 130 , and may be constructed using any clear and transparent polymer or glass. In an embodiment, inner lens assembly 115 is constructed using poly-carbonate material, and contains cylindrical lenses constructed on a surface facing the LEDs (example LEDs 120 and 121 ) on PCB sub-assembly 130 . Inner lens assembly 115 is mounted on PCB sub-assembly using fasteners (fastener 135 is shown in FIG. 1A ).
[0022] PCB sub-assembly 130 may be constructed using any PCB material and has LEDs mounted on it in a desired arrangement to obtain a desired illumination. LEDs may be of any type such as axial lead LEDs, surface-mount package, etc. PCB sub-assembly 130 is mounted on casing 125 using fasteners (fastener 135 is shown in FIG. 1A ).
[0023] Casing 125 is a structure on which inner lens assembly 115 , PCB sub-assembly 130 and lamp enclosure 110 are fitted. In an embodiment, casing 125 is constructed using fiber reinforced glass and has a groove to accommodate lamp enclosure 110 .
[0024] Lamp enclosure 110 encloses inner lens 115 and PCB-subassembly 130 , and may be designed to have a desired shape/profile. Lamp enclosure 110 may be constructed using any clear and transparent polymer or glass, and in an embodiment is constructed using polycarbonate material.
[0025] FIGS. 2A, 2B and 2 C are diagrams showing sectional views from different angles of vehicular lamp 100 , and FIG. 2D is a diagram showing the top view of vehicular lamp 100 . The various components/assemblies shown in each of FIGS. 2A-2D correspond to similarly numbered components/assemblies in the drawings of FIGS. 1A-1C .
[0026] Since, directing elements used to obtain a desired illumination are constructed on an assembly (inner lens assembly 115 in FIGS 1 A- 1 C and 2 A- 2 D) physically separate from the lamp enclosure 110 , the designer/user has a greater degree of freedom in choosing desired stylistic/aesthetic features for lamp enclosure 110 . This may be better appreciated from FIG. 3 which is a diagram showing an exploded view of vehicular lamp 100 , with lamp enclosure 110 , PCB sub-assembly 130 , inner lens assembly 115 and casing 125 being shown separately.
[0027] It is generally desirable to construct lenses on inner lens assembly 115 such that greater error tolerance is provided to the positions at which LEDs in PCB sub-assembly 130 need to be mounted. In the example embodiment (vehicular lamp 100 ) shown in FIGS. 1A-1C and 2 A- 2 D, this is achieved using cylindrical lenses. The description is continued with an illustration of the inner lens assembly 115 in an example embodiment.
[0000] 3. Inner Lens Assembly
[0028] FIG. 4 is a diagram showing a 3 D view of inner lens assembly 115 illustrating the construction of directing lenses on an inner surface (i.e., facing the LED array) of the inner lens assembly. Lenses 116 , 417 - 420 are cylindrical lenses constructed on an inner surface. As may be seen from FIGS. 1A-1C and 2 A- 2 D, each of lenses 116 / 417 - 420 serves to direct the light output from two or more corresponding LEDs. Since each lens is cylindrical, corresponding LEDs may be positioned on PCB sub-assembly 130 with greater tolerance along the direction corresponding to the axis of the lens.
[0029] Mounting brackets 430 - 434 are used for fastening inner lens assembly 115 to casing 125 (of FIGS. 1A-1C and 2 A- 2 D). While the above description is provided with respect to cylindrical lenses, other kinds of lenses may be used (for example, spherical lens), for example, where tolerance for LED positions is not a requirement.
[0030] The operation of the lamp may be better appreciated with a brief description of the functioning of the optics and the need for directing elements in an LED lamp. This is provided below.
[0000] 4. Directing Elements in an LED Lamp
[0031] FIG. 5 is a diagram illustrating the operation and use of directing elements in an LED lamp in one embodiment. The diagram is shown containing LEDs 520 and 521 , printed circuit board (PCB) sub-assembly 530 , lamp enclosure 595 and directing lenses 540 and 550 . Each component is described below in greater detail.
[0032] LEDs 520 and 521 are representative LEDs (and may correspond to LEDs 120 - 121 of FIG. 1A ) comprising an LED array used for providing the light source in lamp 100 (of FIGS. 1A-1C , 2 A- 2 D). In FIG. 5 , the light produced by LEDs 520 and 521 has been approximated as originating from a point source. LEDs 520 and 521 are mounted on PCB sub-assembly 530 (which corresponds to PCB sub-assembly 130 of FIGS. 1 A- 1 C/ 2 A- 2 D), and may be mounted on a suitable assembly/casing (not shown) as described in sections above.
[0033] Directing lenses 540 and 550 are positioned in the path of the light produced by LEDs 521 and 520 , and may be spherical or cylindrical lenses. Further, directing lenses 520 and 521 may be separate elements or constructed on a single element (usually of polymer or glass, and corresponding to inner lens assembly 115 of FIGS. 1 A- 1 C/ 2 A- 2 D).
[0034] Curves 565 and 560 represent the intensity distribution of the light output from LEDs 520 and 521 respectively as a function of the angle from the optical axis (path 571 for LED 520 and path 581 for LED 521 ). The light intensity is maximum along the optical axis and decreases as the angle from the optical axis increases. Thus, for example, the intensity of light output from LED 520 along path 572 will be lesser than a corresponding intensity along path 571 .
[0035] The effect of directing lenses 540 and 550 is to direct the light outputs from LEDs 521 and 520 respectively, and produce light outputs ( 591 and 590 ) so as to meet required specifications/standards. Without the effect of directing lenses 540 and 550 , the light outputs from LEDs 521 and 520 may not provide a desired (for example, as required by automotive standards) illumination meeting a corresponding photometric specification.
[0036] Thus, an aspect of the present invention provides directing lenses (similar to directing lenses 540 and 550 ) as a separate unit, permitting the lamp enclosure to be designed using more complex profiles and incorporating desired aesthetic features.
[0000] 5. Conclusion
[0037] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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According to an aspect of the present invention, lenses used for directing the light beams from lighting elements in a direct lighting vehicular lamp are constructed on an inner lens assembly that is separate from the lamp enclosure. Such a physical separation of the lens assembly and the lamp enclosure may permit complex profiles incorporating stylistic and aesthetic features to be chosen for the lamp enclosure, while maintaining ease of manufacturability.
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[0001] This application claims priority to an application entitled “RANGING METHOD FOR MOBILE COMMUNICATION SYSTEM BASED ON ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SCHEME”, filed in the Korean Intellectual Property Office on Apr. 22, 2002 and assigned Ser. No. 2002-22841, the contents of which is incorporated hereinby reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a ranging method for a BWA (Broadband Wireless Access) system, and more particularly to a ranging method for a mobile communication system using an OFDMA (Orthogonal Frequency Division Multiple Access) scheme.
[0004] 2. Description of the Related Art
[0005] Typically, an OFDMA scheme is defined as a two-dimensional access scheme for combining a TDA (Time Division Access) scheme with a FDA (Frequency Division Access) scheme. In the case of transmitting data using the OFDMA scheme, OFDMA symbols are separately loaded on sub-carriers and transmitted over prescribed sub-channels. A communication system using the OFDMA scheme needs to periodically execute a ranging procedure to correctly establish a time offset between a transmission side, i.e., a Node B, and a reception side, i.e. a UE (User Equipment), and to adjust power between them.
[0006] The ranging procedure is classified into an initial ranging process, a bandwidth request ranging process, and a maintenance ranging process(=periodic ranging process), according to its objectives.
[0007] A RC(ranging code) for the maintenance ranging process corresponds to a periodic code periodically transmitted to the Node B over the UE. The maintenance ranging process is also called a periodic ranging process.
[0008] The objectives of the above three ranging processes have been defined in the IEEE(International Electrotechnical Commission) 802.16.
[0009] The ranging procedure needs ranging sub-channels and RCs, and the UE is assigned with a different RC according to the three objectives. However, the standard document prescribed in the IEEE 802.16 does not define a method for allowing the UE to assign the RC to a variety of ranging processes having different usages and a message thereof.
[0010] The IEEE 802.16 defines a prescribed scheme wherein a Node B transmits a UL_MAP(Uplink Map) message to a UE to inform the UE of reference information in uplink access. The UL_MAP message informs the UE of various information in the uplink, for example, a UE's scheduling period and a physical channel configuration, etc. The UE receives the UL_MAP message, and executes a ranging-related procedure based on information contained in the UL_MAP message. The UL_MAP message is transmitted to all the UEs of a cell over broadcast data of the Node B.
[0011] The UL_MAP message has the following configuration as shown in Table 1.
TABLE 1 Syntax Size UL_MAP_Message_Format( ) { Management Message Type=3 8 bits Uplink channel ID 8 bits UCD Count 8 bits Number of UL_MAP elements n 16 bits Allocation Start Time 32 bits Begin PHY Specific Section { for(i=1; i<n; i+n) UL_MAP_Information_Element { Variable Connection ID UIUC Offset } } } }
[0012] As shown in Table 1, a UL_MAP_Information_Element area serving as an IE (Information Element) area of a UL_MAP message includes a Connection ID(Identifier) area, a UIUC (Uplink Interval Usage Code) area, and an Offset area. The Connection ID area records information indicative of a transmission scheme therein. The transmission scheme is classified into a unicast scheme, a broadcast scheme, and a multicast scheme. The UIUC area records information indicative of the usage of offsets recorded in the offset area. For example, a number of 2 recorded in the UIUC area means that a starting offset for use in the initial ranging process is recorded in the offset areaa number of 3 recorded in the UIUC area means that a starting offset for use in either the bandwidth request ranging or the maintenance ranging process is recorded in the offset area. The offset area records a starting offset value for use in either the initial ranging process or the maintenance ranging process according to the information recorded in the UIUC area.
[0013] The conventional UL_MAP message configuration shown in the Table 1 classifies three ranging processes according to the above objectives, but it does not provide RC allocation by which an independent process for each of the three ranging processes becomes available. In other words, although the conventional UL_MAP message configuration generates a ranging mode by the use of PN (Pseudorandom Noise) code segmentation and also generates a RC available for the three objectives, the UE cannot recognize such information, i.e. the ranging mode and the RC. Therefore, it is necessary for the conventional UL_MAP message to execute a RC allocation for independently performing ranging processes having different objectives.
[0014] Typically, even an OFDMA communication system makes it possible to generate all of the near and non-line-of-sight conditions in the same manner as in a mobile communication system channel environment using other modulation and access schemes, and contains a partial signal blocking caused by wood which may affect signal attenuation and signal multipath. Therefore, there may occur a signal collision in an initial transmission step, irrespective of the type of ranging process used in a UE, and then a random seed for providing the same backoff value as in an initial access time is adapted for a signal re-access time.
[0015] A conventional Node B transmits to the UE a UCD (Uplink Channel Descriptor) message having information indicative of the backoff value in such a way that the UE identifies the backoff value. Such a UCD message will be described in Table 2.
TABLE 2 Syntax Size Notes UCD-Message_Format( ) Management Message Type=0 8 bits Uplink Channel ID 8 bits Configuration Change Count 8 bits Mini-slot size 8 bits Ranging Backoff Start 8 bits Ranging Backoff End 8 bits Request Backoff Start 8 bits Request Backoff End 8 bits TLV Encoded Information for the overall Variable channel Begin PHY Specific Section { for (i=1; i<n ; i+n) Uplink_Burst_Descriptor Variable } } }
[0016] As shown in Table 2, the Node B transmits to the UE a UCD message having information indicative of a backoff value available for a re-access time provided after the lapse of an access failure time of the UE. In other words, the backoff value indicates a kind of standby time being a duration time between the start of UE's access failure time and the start of UE's re-access time. The Node B transmits to the UE the backoff values indicating standby time information for which the UE must wait for the next ranging process after failing to execute an initial ranging process. For example, for a number of 10 determined by the above syntaxes of the “Ranging Backoff Start” and the “Ranging Backoff End” shown in the Table 2, the UE must pass over the 2 10 -times access executable chances (i.e., 1024-times access executable chances) and then execute the next ranging process according to the Truncated Binary Exponential Backoff Algorithm. In more detail, because the UE receives a UL_MAP message and its ranging access time corresponds to a 1025-th access time, a ranging operation can be executed at the 1025-th access time. However, as stated above, a RC is differently assigned to a UE according to the three ranging processes and is also dynamically assigned to the UE according to a cell status, such that a backoff value transmitted with the UCD message must be differently assigned to the UE according to the objectives of RCs.
[0017] In conclusion, a communication system using an OFDMA scheme classifies its ranging procedure into three kinds of ranging processes according to its objective. Although a RC can be differently assigned to the three ranging processes, the UE is unable to identify information indicative of the type of ranging process and is thereby unable to execute an independent ranging operation. The conventional communication system using the OFDMA scheme cannot execute dynamic allocation which is variable with a cell status and a UE's access characteristics because the UE cannot identify such ranging type information, thereby increasing the number of ranging access times of the UE's ranging procedure. As a result, the conventional communication system using the OFDMA scheme has a disadvantage in that it unavoidably increases the length of access delay time and reduces overall system performance.
SUMMARY OF THE INVENTION
[0018] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for dynamically assigning different RCs to a UE according to ranging objectives of the UE in a communication system using an OFDMA scheme.
[0019] It is another object of the present invention to provide a method for assigning a RC to a UE for minimizing the length of ranging access time in a communication system using an OFDMA scheme.
[0020] It is yet another object of the present invention to provide a method for dynamically assigning a backoff value of a RC for use in a UE according to a cell status in a communication system using an OFDMA scheme.
[0021] It is yet another object of the present invention to provide a method for dynamically assigning different backoff values to a UE according to the type of RC in a communication system using an OFDMA scheme.
[0022] In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a method for classifying a ranging procedure between a transmission side and reception sides into an initial ranging process, a bandwidth request ranging process, and a periodic ranging process, and allowing the transmission side to send RCs and their backoff values for use in each ranging process to the reception sides, the method including the steps of determining the number of initial RCs for the initial ranging process, the number of bandwidth request RCs for the bandwidth request ranging process, and the number of periodic RCs for the periodic ranging process; determining a backoff value of the periodic RCs according to the number of the periodic RC; and sending the initial RCs, the bandwidth request RCs, the periodic RCs, and the backoff value of the periodic RCs to the reception sides.
[0023] In accordance with another aspect of the present invention, there is provided a method for classifying a ranging procedure between a transmission side and reception sides into an initial ranging process, a bandwidth request ranging process, and a periodic ranging process, and allowing the transmission side to send RCs and their backoff values for use in each ranging process to the reception sides, the method including the steps of detecting a congestion level of a current cell, if the detected congestion level of the cell is over a prescribed congestion level, controlling the number of the initial RCs for the initial ranging process to be less than either the number of the bandwidth request RCs for the bandwidth request ranging process or the number of the periodic RCs for the periodic ranging process, and varying a backoff value of the periodic RCs; and sending the initial RCs, the bandwidth request RCs, and the periodic RCs, and the backoff value of the periodic RCs to the reception sides.
[0024] In accordance with yet another aspect of the present invention, there is provided a method for classifying a ranging procedure between a transmission side and reception sides into an initial ranging process, a bandwidth request ranging process, and a periodic ranging process, and varying the number of RCs for use in each ranging process in a cell of which the number of total RCs to be used for the ranging processes is predetermined, the method including the steps of allowing the transmission side to determine the number of initial RCs for the initial ranging process, the number of bandwidth request RCs for the bandwidth request ranging process, and the number of periodic RCs for the periodic ranging process, and determining a backoff value of the periodic RCs according to the number of the periodic RCs; sending the initial RCs, the bandwidth request RCs, the periodic RCs, and the backoff value of the periodic RCs to the reception sides; and after receiving the initial RCs, the bandwidth request RCs, the periodic RCs, and the backoff value of the periodic RCs, allowing the reception sides to select a RC corresponding to their current target ranging process, and executing a ranging process corresponding to the selected RC.
[0025] In accordance with yet another aspect of the present invention, there is provided a method for classifying a ranging procedure between a transmission side and reception sides into an initial ranging process, a bandwidth request ranging process, and a periodic ranging process, and varying the number of RCs for use in each ranging process in a cell of which the number of total RCs to be used for the ranging processes is predetermined, the method including the steps of detecting a congestion level of a current cell, if the detected congestion level of the cell is over a prescribed congestion level, controlling the number of the initial RCs for the initial ranging process to be less than either the number of the bandwidth request RCs for the bandwidth request ranging process or the number of the periodic RCs for the periodic ranging process, and varying a backoff value of the periodic RCs; sending the initial RCs, the bandwidth request RCs, and the periodic RCs, and the backoff value of the periodic RCs to the reception sides; and after receiving the initial RCs, the bandwidth request RCs, the periodic RCs, and the backoff value of the periodic RCs, allowing the reception sides to select a RC corresponding to their current target ranging process, and executing a ranging process corresponding to the selected RC.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0027] [0027]FIG. 1 is a diagram illustrating a ranging code allocation procedure for a communication system based on an OFDMA scheme in accordance with a preferred embodiment of the present invention;
[0028] [0028]FIG. 2 is a flow chart illustrating a procedure for assigning a ranging code and a backoff value to each ranging process according to a ranging objective of a Node B in accordance with a preferred embodiment of the present invention; and
[0029] [0029]FIG. 3 is a flow chart illustrating a procedure for assigning a ranging code and a backoff value to a UE according to a ranging objective of the UE in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.
[0031] [0031]FIG. 1 is a diagram illustrating a RC(Ranging Code) allocation procedure for a communication system based on an OFDMA(Orthogonal Frequency Division Multiple Access) scheme in accordance with a preferred embodiment of the present invention.
[0032] With reference to FIG. 1, a RC is created by segmenting a PN(Pseudorandom Noise) code having a prescribed length, for example, the length of 2 15 -bits, in prescribed units. Typically, one ranging channel is composed of two ranging sub-channels each having the length of 53 bits. A RC is created by such a PN code segmentation over a ranging channel of 106 bits. A maximum of 48 RCs RC(Ranging Code)#1˜RC#48 can be assigned to a UE(User Equipment). More than two RCs for every UE are applied as a default value to the three ranging processes having different objectives, i.e. an initial ranging process, a bandwidth request ranging process, and a maintenance ranging(=periodic ranging) process. These ranging processes and their functions are the same as those in the aforementioned prior art. Particularly, a RC for use in the maintenance ranging process corresponds to a periodic code periodically transmitted to the Node B over the UE, such that the maintenance ranging process is also called the periodic ranging process. Therefore, a RC is differently assigned to a UE according to each objective of the three ranging processes. That is, referring to FIG. 1, N RCs are assigned to a UE for the initial ranging process as denoted by a prescribed term of “N RCs for Initial Ranging” in FIG. 1, M RCs are assigned to a UE for the maintenance ranging process as denoted by a prescribed term of “M RCs for maintenance ranging”, and L RCs are assigned to a UE for the bandwidth request ranging process as denoted by a prescribed term of “L RCs for Bandwidth-request ranging”. The RC for the maintenance ranging process is a prescribed code periodically transmitted from the UE to the Node B, such that it is also called a periodic code.
[0033] The standard document prescribed in the IEEE (International Electrotechnical Commission) 802.16 currently defines the maximal number of RCs that can be allocated to the UE and a prescribed default value also allocated to the UE, but it does not describe a detailed method for assigning such RCs to the UE therein. Therefore, the UE is unable to identify reception RC information, such that it is unable to execute an adaptive operation in the case of either a signal collision between transmission RCs or other ranging-related procedures. In order to solve these problems, the present invention proposes a RC allocation method as well as a method for reducing a UE's access delay time by assigning an independent backoff value to each RC, and their detailed description will hereinafter be described.
[0034] In more detail, the present invention classifies RCs according to the aforesaid three objectives, and informs a UE of the range of RCs currently available for the UE, resulting in a minimum access delay time. In this case, a message indicative of such classification and range of the RC is a UL(Uplink)_MAP message, and this UL_MAP message has the following configuration as shown in Table 3.
TABLE 3 Syntax Size UL_MAP_Message_Format( ) { Management Message Type=3 8 bits Uplink channel ID 8 bits UCD Count 8 bits Number of UL_MAP elements n 16 bits Allocation Start Time 32 bits Begin PHY Specific Section { for(i=1; i<n; i+n) UL_MAP_Information_Element { Variable Connection ID UIUC Offset Initial Ranging code Bandwidth request Ranging code Maintenance Ranging code } } } }
[0035] As shown in Table 3, one UE is assigned with 48 RCs as a maximum RC number. Provided that at least two RCs from among the 48 RCs are assigned to the UE as a specific RC for each of the three ranging objectives, the UE is assigned with 6 RCs in total. Such RCs are differently assigned for every ranging objective, one UE is assigned more than two RCs corresponding to each RC for the three ranging objectives, and the maximal number of 48 RCs is available for the one UE. In other words, the UL_MAP message shown in Table 3 contains an initial RC for the initial ranging process, and a periodic RC such as a bandwidth-request RC and a maintenance RC, which is transmitted to the UE. Therefore, the UE receiving the UL_MAP message is able to use a proper RC in response to its own current ranging objective. Also, the Node B dynamically assigns RCs to the UE according to a current cell status. For example, provided that a small number of UEs are interconnected (hereinafter referred to as the connected-state UEs) within a cell, the Node B may assign many RCs (i.e. initial RCs) for use in the initial ranging process to the UEs during an initialization time. Provided that a large number of connected-state UEs are contained in a cell, the Node B may reduce the number of RCs assigned the initial RCs. In brief, the Node B dynamically assigns RCs to each UE according to a congestion state within a cell. Such a dynamic RC allocation may be adapted to control the cell's congestion state and cell priority. The RC allocation is variable with a cell status, resulting in reduction of a UE's access delay time.
[0036] A UCD (Uplink Channel Descriptor) message for differently setting up a backoff value according to the type of RCs will be hereinafter described with reference to Table 4.
TABLE 4 Syntax Size Notes UCD-Message_Format( ) Management Message Type=0 8 bits Uplink Channel ID 8 bits Configuration Change Count 8 bits Mini-slot size 8 bits Initial Ranging Backoff Start 8 bits Initial Ranging Backoff End 8 bits Bandwidth-request Ranging Backoff Start 8 bits Bandwidth-request Ranging Backoff End 8 bits Maintenance Ranging Backoff Start 8 bits Maintenance Ranging Backoff Endt 8 bits Request Backoff Start Request Backoff End 8 bits Request Backoff Start 8 bits TLV Encoded Information for the overall Variable channel Begin PHY Specific Section { for (i=1; i<n ; i+n) Uplink_Burst_Descriptor Variable } } }
[0037] As shown in Table 4, the UCD message provides UEs with different backoff values in response to the number of RCs dynamically assigned to the UEs according to the number of connected-state UEs within a cell and the number of UEs attempting to execute an initial access. That is, if RCs having different objectives are assigned with different backoff values, access to UEs contained in the cell is controlled according to a cell status. In this way, access to the UEs is controlled by assigning different backoff values to the UEs, resulting in a minimal access delay time. For example, in the case where 10 RCs are assigned with an initial ranging process over a UL_MAP message and the remaining RCs other than the 10 RCs are assigned with a bandwidth request ranging process and a maintenance ranging process, the probability of a code collision caused by UEs respectively selecting the same RCs as their initial RCs is {fraction (1/10)}. Therefore, in order to further reduce the probability of such collisions caused by the UEs selecting the same RCs, if a re-access time for which each UE re-accesses RCs for the initial ranging process is divided into a plurality of access time segments, that is, if the UEs each are assigned a high initial ranging backoff value, the probability of access collisions from among the UEs in the initial ranging process can be significantly reduced. Even in the case where the bandwidth request ranging process typically assigned many more RCs than the initial ranging process is assigned a relatively low backoff value lower than the initial ranging backoff value, the probability of UEs collisions in the bandwidth request ranging process can also be reduced because the number of RCs assigned to the bandwidth request ranging process is much more than the number of other RCs assigned to the initial ranging process. In this way, an access time of each UE is shortened by reducing a backoff value for use in the bandwidth request ranging process.
[0038] The Node B for executing a RC allocation and a backoff value allocation according to a ranging objective will hereinafter be described with reference to FIG. 2.
[0039] [0039]FIG. 2 is a flow chart illustrating a procedure for assigning a RC and a backoff value to each ranging process according to a ranging objective of a Node B in accordance with a preferred embodiment of the present invention.
[0040] Referring to FIG. 2, the Node B checks its own cell status at step 210 . In more detail, the Node B checks a congestion state of its own cell on the basis of the number of UEs currently in a traffic state at step 210 . The Node B generates RCs at step 212 . In more detail, as previously stated in FIG. 1, the Node B generates a plurality of RCs by segmenting a PN code having the length of 2 15 -1 bits in predetermined units at step 212 . The Node B assigns RCs to be used for three ranging processes having different objectives, i.e. the initial ranging process, the bandwidth request ranging process, and the maintenance ranging process, to the three ranging processes, respectively, at step 214 . In more detail, as previously stated in FIG. 1, the Node B assigns N number of RCs to the initial ranging process, assigns L number of RCs to the bandwidth request ranging process, and assigns M number of RCs to the maintenance ranging process at step 214 . In case of assigning the RCs to each ranging process at step 214 , the Node B varies the number of RCs to be used for the initial ranging process, the bandwidth request ranging process, and the maintenance ranging process, according to the cell status checked at step 210 . In the case where it is determined at step 216 that the cell is in a heavy load state over a prescribed congestion state, the Node B goes to step 218 .
[0041] The Node B controls the number L of RCs for the bandwidth request ranging process to exceed the number N of RCs for the initial ranging process and executes RC allocation for the bandwidth request ranging process at step 218 because the cell is in such a heavy load state at step 216 , and goes to step 220 . That is, the Node B executes RC allocation for the bandwidth request ranging process in a prescribed condition of L>N at step 218 . The reason why the Node B provides such a prescribed condition of L>N at step 218 is to minimize the number of collisions caused by the UEs' initial ranging operation, as previously stated above. In more detail, provided that any cell is in a high congestion state, this means that this cell has too much traffic. Therefore, in case of assigning RCs to each ranging process, the Node B controls the number L of RCs to be used for the bandwidth request ranging process to exceed the number N of RCs to be used for the initial ranging process, thereby minimizing the number of uplink access collisions of UEs at step 218 . The Node B executes backoff-value allocation for the bandwidth request ranging process at step 220 . In this case, provided that a backoff value for the initial ranging code is denoted by a reference character ‘A’, a backoff value for the bandwidth request ranging code is denoted by a reference character ‘B’, and a backoff value for the maintenance ranging code is denoted by a reference character ‘C’, the Node B controls the backoff value of B to be less than the backoff value of A at step 220 , that is, provides a prescribed condition of B<A at step 220 , and then goes to step 222 . The backoff value reduces the length of re-access time caused by access collisions among several UEs in inverse proportion to the backoff value, differently from the number of RCs, thereby minimizing a delay time caused by the uplink access collision of UEs. That is, the lower the backoff value, the shorter the re-access time of the UEs.
[0042] The Node B controls the number M of RCs (hereinafter referred to as a maintenance RCs) for the maintenance ranging process to exceed the number N of RCs (hereinafter referred to as initial RCs) for the initial ranging process and executes RC allocation for the maintenance ranging process at step 222 , and goes to step 224 . The Node B controls the backoff value of C being a maintenance ranging backoff value to be less than the backoff value of A being an initial ranging backoff value at step 224 , that is, executes backoff-value allocation for the initial ranging process in a prescribed condition of C<A at step 224 , and goes to step 226 . The Node B controls the number N of initial RCs to be less than either the number L of bandwidth request RCs or the number M of maintenance RCs and executes the initial RCs' allocation at step 226 , and goes to step 228 . The Node B controls the initial ranging backoff value of A to exceed either the bandwidth request ranging backoff value of B or the maintenance ranging backoff value of C at step 228 , that is, provides a prescribed condition of A>B or C at step 228 , and then goes to step 242 .
[0043] In the meantime, in the case where it is determined at step 216 that the cell is not in the heavy load state over a prescribed congestion state, the Node B goes to step 230 . Steps 230 - 240 are performed in opposition to the above steps 218 - 228 . In more detail, the Node B controls the number L of bandwidth request RCs to be less than the number N of initial RCs and executes RC allocation for the bandwidth request ranging process at step 230 because the cell is in a relatively low congestion state at step 216 , and goes to step 232 . The Node B controls the bandwidth request ranging backoff value of B to exceed the initial ranging backoff value of A at step 232 , that is, provides a prescribed condition of B>A at step 232 , and then goes to step 234 . The Node B controls the number M of maintenance RCs to be less than the number N of initial RCs at step 234 , that is, provides a prescribed condition of M<N at step 234 , and goes to step 236 . The Node B controls the maintenance ranging backoff value of C to exceed the initial ranging backoff value of A at step 236 , that is, executes backoff-value allocation for the maintenance ranging process in a prescribed condition of C>A at step 236 , and goes to step 238 . The Node B controls the number N of initial RCs to exceed either the number L of bandwidth request RCs or the number M of maintenance RCs at step 238 , that is, executes the initial RCs' allocation at step 238 in a prescribed condition of N>M or L at step 238 , and goes to step 240 . The Node B controls the initial ranging backoff value of A to be less than either the bandwidth request ranging backoff value of B or the maintenance ranging backoff value of C at step 240 , that is, executes the backoff-value allocation for the initial ranging process in a prescribed condition of A<B or C at step 240 , and then goes to step 242 .
[0044] The Node B creates a UL_MAP message having a plurality of RCs classified according to ranging objectives shown in Table 3 at step 242 , and goes to step 244 . In this case, the RCs are classified into an initial RC, a bandwidth request RC, and a maintenance RC, according to such ranging objectives. The Node B inserts backoff values responsive to the type of RCs shown in Table 4 into a UCD message at step 244 , and transmits the UL_MAP message and the UCD message having the backoff values to a necessary UE.
[0045] The UE for executing a ranging code allocation and a backoff value allocation according to a ranging objective will hereinafter be described with reference to FIG. 3.
[0046] [0046]FIG. 3 is a flow chart illustrating a procedure for assigning a RC and a backoff value to a UE according to a ranging objective of the UE in accordance with a preferred embodiment of the present invention.
[0047] Referring to FIG. 3, the UE receives a message from the Node B, and goes to step 312 . The UE determines at step 312 whether the received message is a UL_MAP message. If the received message is the UL_MAP message at step 312 , the UE goes to step 314 . The UE analyzes the UL_MAP message to check the RCs, i.e. the initial RC, the bandwidth request RC, and the maintenance RC, at step 314 . If these RCs are checked at step 314 , then the UE goes to step 322 . However, if it is determined that the received message is not the UL_MAP message at step 312 , the UE goes to step 316 . The UE determines at step 316 whether the received message is a UCD message. If the received message is not a UCD message at step 316 , the UE goes to step 318 . The UE processes a message corresponding to the received message at step 318 , and terminates a program.
[0048] In the meantime, if the received message is a UCD message at step 316 , then the UE goes to step 320 . The UE analyzes the UCD message to check backoff values of RCs contained in the UCD message, i.e. a backoff value of the initial RC, a backoff value of the bandwidth request RC, and a backoff value of the maintenance RC, at step 320 , and goes to step 322 . The UE establishes the mapping between the checked RCs and their backoff values at step 322 , and goes to step 324 . The UE determines at step 324 whether its current ranging objective is an initial ranging objective. If it is determined at step 324 that a current ranging objective is the initial ranging objective, the UE goes to step 326 . The UE selects at step 326 the initial RC and its backoff value from among the mapping values of step 320 , and goes to step 334 . If it is determined at step 324 that a current ranging objective is not the initial ranging objective, the UE goes to step 328 . The UE determines at step 328 whether a current ranging objective is a bandwidth request ranging objective. If it is determined at step 328 that a current ranging objective is the bandwidth request ranging objective, the UE goes to step 330 . The UE selects a bandwidth request RC and its backoff value from among the mapping values at step 330 , and goes to step 334 . If it is determined at step 328 that a current ranging objective is not the bandwidth request ranging objective, the UE goes to step 332 . The UE selects a maintenance RC and its backoff value from among the mapping values at step 332 because a current ranging objective is by elimination the maintenance ranging objective, and goes to step 334 .
[0049] After the UE selects a current target RC and its backoff value in either one of steps 326 , 330 , and 332 , it executes uplink access with the selected RC and its backoff value at step 334 , and goes to step 336 . If the UE does not receive a response to the uplink access within a prescribed period of time at step 336 , it is determined that a code collision occurs in the uplink access, and returns to step 324 . The UE executes successive operations for the uplink access according to a ranging objective and its backoff value at step 324 . In the meantime, if the UE receives a response to the uplink access within the prescribed period of time at step 336 , it is determined that no collision occurs in the uplink access, i.e. it is determined that a normal uplink access is executed, and then goes to step 338 . The UE terminates uplink access transmission or executes other transmission operations at step 338 .
[0050] As apparent from the above description, a Node B of a communication system based on an OFDMA scheme assigns different RCs and their backoff values to the ranging processes according to ranging objectives, and informs a UE of such allocation result, resulting in a minimal number of uplink access collisions of the UE. The Node B dynamically assigns the number of RCs and their backoff values to the ranging processes according to a cell status and a ranging objective, resulting in a minimal uplink access delay time.
[0051] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed herein is a ranging method for a mobile communication system based on an OFDMA (Orthogonal Frequency Division Multiple Access) scheme. In the communication system for classifying a ranging procedure between a transmission side and reception sides into an initial ranging process, a bandwidth request ranging process, and a periodic ranging process, the ranging method includes the steps of determining the number of initial RCs(ranging codes) for the initial ranging process, the number of bandwidth request RCs for the bandwidth request ranging process, and the number of periodic RCs for the periodic ranging process, determining a backoff value of the periodic RCs according to the number of the periodic RCs, and sending the initial RCs, the bandwidth request RCs, the periodic RCs, and the backoff value of the periodic RCs to the reception sides.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 642,200 filed Dec. 18, 1975, now abandoned.
BACKGROUND OF THE INVENTION
In the repair of automobile frames or the like which have been damaged due to accidents, or the like, it is essential that the frame of the vehicle be restored to its original condition as otherwise any repair done to the body of the vehicle will serve only to restore the body portion to its original condition and if the vehicle frame has not been restored to its original condition, such body repair work will be in vain insofar as rendering the vehicle safe for travel. As can be appreciated, if the frame of the vehicle has not been restored to its original condition, it will be virtually impossible to align the wheels of the vehicle thus resulting in a vehicle which will either pull to the left or to the right during travel thereof, and, even at a moderate rate of speed of the vehicle, the operator thereof will encounter difficulties in maintaining the desired direction of travel, thus contributing to the cause of an accident. Also, in devices employed in the past for straightening a bent vehicle frame, complex devices have been used to straighten a bent portion of a frame and such prior devices, due to their structural shortcomings, have not proven to be entirely satisfactory.
Thus, with the above in mind, it is the primary object of the invention to provide a simple yet very effective structure capable of straightening the bent portion of a vehicle frame with relative ease and with a minimum number of man hours required to effect such frame straightening.
Another object of the invention is to provide a vertically extending framework with power means mounted thereon, said power means capable of being shifted along said vertically extending framework to thus enable the operator of the frame straightener to apply a pulling force at the exact location on the frame where such pulling force is to be applied in order to straighten a bent frame.
Another object of the invention is to provide an adjustable base upon which a bent vehicle frame is mounted and secured thereto and retained thereon during the application of the pull forces for straightening the bent frame.
Another object of the invention is to provide an efficient means for locking the adjustable base in the desired position so that when a pulling force is exerted on the bent vehicle frame mounted thereon, the angle of such pulling force on the bent frame will be such as to straighten out the bent portion of the frame.
Another object of the invention is to mount a pair of hydraulic or pneumatic power cylinders on vertically extending and laterally adjustable standards which are mounted on a generally rectangularly shaped support tower which is rigidly secured at the lower end thereof to a suitable framework extending along a supporting surface such as the floor of a garage, or, in instances where the straightening equipment is exteriorly of a garage, the framework may be ground supported.
The many advantages of the invention will be more readily apparent and appreciated as the same becomes understood by reference to the following detailed description which is to be considered in connection with the accompanying drawings wherein like reference characters designate like parts throughout the several figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the manner in which a pulling force is applied to a vehicle frame mounted on an adjustable base.
FIG. 2 is a sectional view with parts broken away showing the rotatable drum on which is mounted the adjustable base.
FIG. 3 is an enlarged sectional view showing the manner of locking the rotatable drum in the desired position.
FIG. 4 is a side elevational view showing the power cylinder and associated parts mounted on the laterally adjustable standards, and,
FIG. 5 is an enlarged view with parts broken away showing the manner in which the laterally adjustable standards may be retained in their adjusted position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawings, numeral 10 designates generally a vehicle frame straightening apparatus constructe in accordance with the present invention. A pair of spaced apart I-beams 11 may be either floor or ground supported and supported thereon are a pair of horizontally extending spaced apart beams 12. The horizontal beams 12 may be welded, brazed or otherwise secured to the I-beams 11 so as to form a rigid structure for supporting a vehicle frame supporting framework indicated generally at 13 in FIG. 1 of the drawings.
The framework 13 comprises a pair of spaced apart parallely extending channel irons or the like 14, each having a series of slots 15 formed in the side walls of the channel irons 14 for a purpose to be described more fully hereinafter. Mounted on a suitable framework 16 extending between the horizontally extending beams 12 is a cylindrical drum 17 to which is welded or otherwise secured the channel irons 14. The drum is mounted for rotation on a vertical shaft 18 provided on the framework 16 for the aforesaid drum. A flange 19 extends along the lower edge of the drum 17 and a plurality of slots 20 are formed therein for receiving therein a locking arm 21 for locking the drum against rotational movement once the drum and framework 13 secured thereto has been rotated to the desired position. A pull cord or the like 22 extends from a spring biased lever arrangement 23 pivotally mounted on the framework 16 and a tie rod 24 extends from one end of the lever 23 to the locking arm 21. Thus, when it is desired to rotate the drum 17 and associated framework 13 so as to properly position the framework 13 with respect to a pulling force which is to be applied to a bent vehicle frame mounted on the framework 13, a pull on the pull cord 22 will retract the locking arm 21 from within one of the aforesaid slots 20 and following the rotation of the drum 17 and associated framework 13 to the desired position, release of the pull cord will cause said spring biased lever arrangement to cause the locking arm to enter into one of the slots 20 to thus lock the drum 17 and framework 13 from further rotation.
The framework 13 comprises a plurality of flat steel plates 25 extending parallel to but spaced from one another as shown more clearly in FIG. 1 of the drawings. The plates 25 are welded or otherwise secured to the channel irons 14 forming the framework shown generally at 13. Transfer beams 26 extend between the channel irons 14 and are secured in adjusted position between the said channel irons 14 by means of the slots 15 formed therein which receive the outer ends of the aforesaid transfer beams. A plurality of openings 27 are formed in the transfer beams and a pin or the like is employed for securing a generally vertically extending brace arm 28 to said transfer beam which is also provided with a plurality of openings 29. A chain or the like 30 having suitable anchors formed at either ends thereof extend from the brace arm to which it is anchored to the area between the plates 25 and anchored therein for retaining the brace arm in adjusted position on the framework 13. As shown in FIG. 1 of the drawings, a plurality of such transfer arms are mounted on said transfer beams so that the frame to be straightened may be engaged by said brace arms at a plurality of points to insure the retaining of the bent frame on the framework 13 when a pulling force is applied thereto during the straightening operation.
Shown in FIG. 1 of the drawings is a vehicle frame 31 of known construction. The frame 31 having a portion thereof to be straightened is placed on the framework 14 and the brace arms 28 are adjusted with respect to the frame and when the brace arms are in their proper position against the vehicle frame the same are locked in place by the chains 30 in the manner aforesaid.
The pulling force for straightening a bent vehicle frame is derived from a hydraulic or pneumatic cylinder which is mounted on a vertical standard 32 which extends between a pair of vertically disposed side frame members 33 which are welded or otherwise secured to a pair of horizontally extending beams 34 to form a tower assembly for the motive power supplying the pulling forces for the apparatus. As can be appreciated, the side frame members 33 are welded or otherwise secured to the horizontal beams 12 in order to provide a rigid structure for the tower assembly. Shown in the drawing at FIG. 1 are a pair of such vertical standards 32 but it should be understood the tower may have more such standards or, for that matter, the tower can have but one such vertical standard and still function in its intended manner.
Mounted for travel on said vertical standards 32 are a pair of connector arms 35, each provided with a chain locking plate 36. As stated previously, the motive power sources may be either hydraulic or pneumatic. A suitable motor and pump assembly shown generally at 37 is secured in any known manner to one of the side frame members 33 and flow lines 38 extend to and from the pump assembly to the cylinder 39 which is secured in any known manner to the vertical standard 32. As can be appreciated each vertical standard will be provided with a cylinder 39. Extending between the vertical standards 32 and a pair of parallely disposed spaced apart roller carrying plates 40 are a plurality of connector straps 41. Extending above the upper horizontal frame member 34 is also a pair of connector plates 42 which are secured in any known manner to the vertical standards 32 and to the roller carrying plates 40. Thus it will be seen that the vertical standards 32 and the roller carrying plates 40 are interconnected. As stated previously, the vertical standards 32 and cylinders 39 affixed thereto along with the roller carrying plates 40 are capable of being moved laterally along the horizontal frame members 34 so as to enable the operator of the apparatus to apply the pulling forces in proper alignment with the section of the frame to be straightened.
Fixed in any known manner on the upper and lower horizontal members 34 shown more particularly in FIG. 5, are equally spaced apart tabs 43 between which the vertical standards are adapted to be nested and held from lateral movement along the horizontal frame members 34 when the motive power source is activated to realign a bent portion of a frame member 31. As shown more clearly in FIG. 4 of the drawings, a plurality of openings 44 are formed in each pair of roller carrying plates 40 and a roller 45 of known construction is held between the aforesaid roller carrying plates 40 by means of a removable pin 46 extending through the openings 44 and a central bore extending through the roller 45. As can be appreciated, the roller 45 may be adjusted to varying height adjustment on the roller carrying plates 40 merely be removing the pin 46 and placing the roller in the area where the same will be most efficient to accomplish the desired angle of pull on the bent frame. Secured to the locking plate 36 is a chain or like member 47 and is then trained over pulleys 48, 49 mounted in suitable bearings between the connector plates 42. Thence the chain extends between the roller carrying plates 40 and then trained over a roller 45 mounted therebetween. A hook or anchor 50 is secured to the free end of the chain for engagement with a portion of a bent frame.
Operation of the equipment is as follows. A bent frame is placed on the framework and by means of the brace arms the same is held thereon in the desired position. If the side of the frame has to be straightened, the drum and framework secured thereto are rotated so that the side of the frame will be facing the tower assembly and when this has been accomplished the vertical standards, cylinder mounted thereon and the roller carrying plates are moved as one body along the horizontal frame member to thus position the same in alignment with the portion of the frame to be straightened. The chain hook or anchor is then applied to that section of the frame to be straightened and then the motive power is activated to activate the cylinder to apply a pulling force on the chain to thus pull on the bent portion of the frame to effect a straightening thereof. By varying the position of the roller 45 in the roller carrying plates, an upward or a downward pull can be exerted on the frame. Also, if a combined upward or downward force coupled with a side pulling force is necessary to effect the straightening of the bent portion of the frame, the standards 32 may be so positioned in the tower assembly as to effect a side pulling on the frame. Of course, the position of the bend frame on the framework can be adjusted relative to the pulling forces by rotating the drum and locking the same in the adjusted position.
While the invention has been described particularly with straightening vehicle frames it is submitted the equipment of the present invention can also be successfully employed in straightening other parts of a vehicle, or for that matter, any bent metallic object can be straightened the only requirement being that the same can be effectively secured to the framework.
While a preferred embodiment of the present invention has been described hereinabove, it is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted as illustrated and not in a limiting sense and that all modifications, constructions and arrangements which fall within the scope and spirit of the invention may be made.
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Improvement in an apparatus designed to be employed in the straightening of a damaged vehicle frame or the like wherein a vertically extending tower having pulling members mounted thereon and a rotatally mounted framework for supporting a vehicle frame to be straightened is employed and can be adjusted in a desired position whereby when a pulling force is exerted on the said frame by means of the aforesaid pulling the bent or otherwise damaged portion of the frame may be restored to it's original unbent condition.
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FIELD OF THE INVENTION
This invention is directed to a polymer thick film encapsulant composition. Encapsulants made from the composition can be used in various electronic applications to protect electrical elements and particularly to encapsulate a Positive Temperature Coefficient carbon resistor for use in self-regulating heater circuits.
BACKGROUND OF THE INVENTION
Encapsulants have long been used to protect electrical elements. Positive Temperature Coefficient (PTC) circuits are typically used as self-thermostating circuits, for example, in automobile mirror heaters and seat heaters. They are used in place of an external thermostat. Although they have been used for years in these types of applications, the performance of the PTC circuits typically have performance problems as a result of resistance shift stability, powered on/off cycling inconsistency, and sensitivity to their environment. All these issues can have a negative impact on a functional PTC circuit. One of the purposes of this invention to alleviate these issues and produce a more efficient and reliable PTC circuit with enhanced stability
SUMMARY OF THE INVENTION
This invention relates to a polymer thick film encapsulant composition comprising:
(a) a first organic medium comprising 30-60 wt % thermoplastic fluoropolymer resin dissolved in a first organic solvent, wherein the weight percent is based on the total weight of the first organic medium; and (b) a second organic medium comprising 10-50 wt % acrylic resin dissolved in a second organic solvent, wherein the weight percent is based on the total weight of the second organic medium.
In some embodiments the thermoplastic fluoropolymer resin is a polyvinylidene fluoride homopolymer or a polyvinylidene fluoride-based copolymer. In one such embodiment the thermoplastic fluoropolymer resin is polyvinylidene fluoride-hexafluoropropylene-tetrafluoroethylene coplolymer. The acrylic resin of some embodiments is methyl methacrylate copolymer.
The invention is further directed to using the encapsulant to form an encapsulant in PTC heater electrical circuits and, in particular, in the PTC circuitry in mirror heater and seat heater applications. The invention provides heaters comprising such an encapsulant. The encapsulant has been found to improve the stability of the PTC circuit.
DETAILED DESCRIPTION OF INVENTION
The invention relates to a polymer thick film encapsulant composition for use in forming an encapsulant in electrical circuits and, in particular, in PTC heating circuits. A layer of encapsulant is printed and dried on an active PTC carbon resistor so as to encapsulate and protect the PTC resistor.
The polymer thick film (PTF) encapsulant composition is comprised of two organic media, each comprising a polymer resin and a solvent. Additionally, powders and printing aids may be added to improve the composition.
Organic Media
The first organic medium is comprised of a thermoplastic fluoropolymer resin dissolved in a first organic solvent. The fluoropolymer resin must achieve good adhesion to both the electrical element, e.g., the PTC carbon layer, and the underlying substrate. It must be compatible with and not adversely effect the performance of the electrical element. In one embodiment the thermoplastic fluoropolymer resin is 30-60 wt % of the total weight of the first medium. In another embodiment the thermoplastic fluoropolymer resin is 35-55 wt % of the total weight of the first medium and in still another embodiment the thermoplastic fluoropolymer resin is 47-53 wt % of the total weight of the first medium. In some embodiments the thermoplastic fluoropolymer resin is a polyvinylidene fluoride homopolymer or a polyvinylidene fluoride-based copolymer. One such polyvinylidene fluoride-based copolymer is polyvinylidene fluoride-hexafluoropropylene-tetrafluoroethylene coplolymer.
The second organic medium is comprised of an acrylic resin dissolved in a second organic solvent. In one embodiment the acrylic resin is 10-50 wt % of the total weight of the second medium. In another embodiment the acrylic resin is 20-40 wt % of the total weight of the second medium and in still another embodiment the acrylic resin is 25-35 wt % of the total weight of the second medium. In one embodiment the acrylic resin is methyl methacrylate copolymer.
The polymer resin is typically added to the organic solvent by mechanical mixing to form the medium. Solvents suitable for use in the polymer thick film composition are recognized by one of skill in the art and include acetates and terpenes such as carbitol acetate and alpha- or beta-terpineol or mixtures thereof with other solvents such as kerosene, dibutylphthalate, butyl carbitol, butyl carbitol acetate, hexylene glycol and high boiling alcohols and alcohol esters. In addition, volatile liquids for promoting rapid hardening after application on the substrate may be included. In many embodiments of the present invention, solvents such as glycol ethers, ketones, esters and other solvents of like boiling points (in the range of 180° C. to 250° C.), and mixtures thereof may be used. Various combinations of these and other solvents are formulated to obtain the viscosity and volatility requirements desired. The solvents used must solubilize the resins. The first solvent and second solvent may be different or may be the same.
Typically, the first medium is from 70 to 97 wt % of the total weight of the PTF encapsulant composition and the second medium is from 3 to 30 wt % of the total weight of the PTF encapsulant composition. In one embodiment, the first medium is from 80 to 96 wt % of the total weight of the PTF encapsulant composition and the second medium is from 4 to 20 wt % of the total weight of the PTF encapsulant composition.
Powders
Various powders may be added to the PTF encapsulant composition to improve adhesion, modify the rheology and increase the low shear viscosity thereby improving the printability. One such powder is fumed silica.
Application of the PTF Encapsulant Composition
The PTF encapsulant composition, also referred to as a “paste”, is typically deposited on a substrate, such as polyester, that is impermeable to gases and moisture. The substrate can also be a sheet of a composite material made up of a combination of plastic sheet with optional metallic or dielectric layers deposited thereupon.
The deposition of the PTF encapsulant composition is performed typically by screen printing, but other deposition techniques such as stencil printing, syringe dispensing or coating techniques can be utilized. In the case of screen-printing, the screen mesh size controls the thickness of the deposited thick film.
Generally, a thick film composition comprises a functional phase that imparts appropriate electrically functional properties to the composition. The functional phase comprises electrically functional powders dispersed in an organic medium that acts as a carrier for the functional phase. Generally, the composition is fired to burn out both the polymer and the solvent of the organic medium and to impart the electrically functional properties. However, in the case of a polymer thick film, the polymer portion of the organic medium remains as an integral part of the composition after drying. Prior to firing, a processing requirement may include an optional heat treatment such as drying, curing, reflow, and others known to those skilled in the art of thick film technology.
The PTF encapsulant composition is processed for a time and at a temperature necessary to remove all solvent. For example, the deposited thick film is dried by exposure to heat at 140° C. for typically 10-15 min.
PTC Heating Circuit
One uses of the PTF encapsulant composition is as an encapsulant for the PTC resistor in a PTC heating circuit. In one embodiment this PTC resistor is comprised of PTC carbon black. One such carbon black resistor is disclosed in Dorfman, U.S. Pat. No. 5,714,096. This PTC carbon black resistor is formed by screen printing a positive temperature coefficient composition comprising:
(i) 15-30 wt % carbon black possessing a DBP absorption of about 125 cc/100 g carbon black or less; (ii) 10-40 wt % chlorinated, maleic anhydride grafted polypropylene resin; and (iii) organic medium capable of solubilizing the resin, wherein the composition is heated to remove the organic medium and thereby forms a positive temperature coefficient carbon resistor.
The PTF encapsulant composition is then screen printed onto the PTC carbon resistor so that it encapsulates the positive temperature coefficient carbon resistor and is dried to form the encapsulant. As pointed out in Dorfman, U.S. Pat. No. 5,714,096 low structure carbon blacks are preferred. A common test used to quantify low structure is the absorption of dibutyl phthalate (DBP) oil, measured in cc's of oil absorbed per 100 grams of carbon black.
EXAMPLE 1
The PTF encapsulant composition was prepared in the follow manner. The first organic medium, Medium A, was prepared by mixing 50.0 wt % KYNAR® 9301 (obtained from Arkema Inc., Phila., Pa.) polyvinylidene fluoride-hexafluoropropylene-tetrafluoroethylene coplolymer resin with 50.0 wt % carbitol acetate (obtained from Eastman Chemical, Kingsport, Tenn.) organic solvent. The molecular weight of the resin was approximately 20,000. This mixture was heated at 90° C. for 1-2 hours to dissolve all the resin. The second organic medium, Medium B, was produced by adding 30.0% Elvacite® 2008 Acrylic Resin (obtained from ICI Acrylics, Inc., now Lucite International, Inc.), a methyl methacrylate resin, to a 50/50 mixture of carbitol acetate and beta-terpineol organic solvents. This mixture was heated and stirred at 90° C. for 1-2 hours to dissolve all the resin. The two media were mixed in the wt % ratios shown below. Fumed silica (obtained from Cabot Corp., Boston, Mass.), a silicone printing aid and additional carbitol acetate solvent were also added in the wt %'s shown.
The composition, based on the total weight of the composition, was:
86.04 wt %
Medium A
5.81
Medium B
0.93
Fumed silica
0.24
Silicone Printing Aid
6.98
Carbitol acetate solvent
This composition was mixed for 30 minutes on a planetary mixer. The composition was then transferred to a three-roll mill where it was subjected to one pass at 150 psi to produce the PTF encapsulant composition.
A PTC circuit was then fabricated as follows. A pattern of a series of interdigitated silver lines were printed with DuPont silver paste 5064 (E. I. DuPont, Wilmington, Del.) using a 280 mesh stainless steel screen. The patterned lines were dried at 140° C. for 15 min. in a forced air box oven. Then, a standard PTC circuit pattern was overprinted with DuPont Product 7282 PTC carbon (DuPont, Wilmington, Del.) to form a wide geometry resistor with the interdigitated 5064 silver termination. This was printed using a 280 mesh stainless steel screen. The PTC carbon was dried at 140° C. for 15 min. in a forced air box oven. Finally, the encapsulant composition was screen printed over the PTC pattern using the same screen as above and dried at 140° C. for 15 min. The resistance shift of the PTC circuit after holding the circuit at 90° C. for 24 hours was measured and the results are shown in Table 1. The power cycling shift was also measured. Power cycling was carried by applying 12 Volts for 15 minutes and power was then removed for 45 minutes. This was repeated hourly and the equilibrium temperature was measured during the power-on cycle. The results are shown in Table 1.
COMPARATIVE EXAMPLE 1
A PTC circuit was produced exactly as described in Example 1. The only difference was that the encapsulant composition was not used. Properties of this PTC circuit are summarized in Table I.
TABLE I
Resistance Shift
Power Cycling Shift
24 Hrs. @ 90° C.
(20 Cycles)
Example 1
−3.0%
2 Degree C. Shift
Comparative Example 1
−13.0%
10 Degree C. Shift
(no encapsulant)
The improvement in performance as a result of the encapsulant is apparent from the results shown in Table I. The resistance shift observed without the encapsulant is over 4 times that with the encapsulant. With the power cycling the equilibrium temperature without the encapsulant, continues to rise with each cycle but the encapsulated heater circuit shows good temperature stability. Additionally, the magnitude of the PTC effect as measured by the ratio of the resistance at 70° C. to the resistance at room temperature was approximately 20% higher in the PTC circuit of Example 1 compared to that of the PTC circuit of Comparative Example 1, further supporting the improvement seen when using the Encapsulant.
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The invention is directed to a polymer thick film encapsulant composition comprising thermoplastic fluoropolymer resin and acrylic resin dissolved in organic solvents. The deposited encapsulant composition is processed at a time and energy sufficient to remove all solvent and form an encapsulant. The invention is further directed to using the encapsulant composition to form an encapsulant in PTC heater circuitry and, in particular, in PTC heater circuitry in mirror heater and seat heater applications.
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This is a continuation of copending application Ser. No. 07/596,186, filed Oct. 12, 1990, now abandoned.
BACKGROUND OF THE INVENTION
Branched aromatic carbonate polymers have been well known for many years. The branching agents employed are tri-functional or higher molecules which can incorporate within a linear aromatic carbonate polymer chain and have a functional group left for further reaction which provides the branched molecule. Various branching agents have been utilized in polycarbonate to prepare a branched polycarbonate. One of the latest being used is the compound 1,1,1-tris-(4-hydroxyphenyl)ethane.
The utilities for these branched polycarbonates are generally well known and are characterized by their increased melt strength. Such utilities include film, fibers, sheets, tubes, rods and in particular blow molding applications such as bottles and various containers. The previously mentioned compound, abbreviated hereafter as THPE, was used to replace tri mellitic trichloride (TMTC). The latter compound has been used as a branching agent in polycarbonate for many years. However it had the inherent problem of having poor stability to ultra violet radiation. The UV stability of the branched polycarbonate having the THPE therein was substantially increased. However an unforeseen problem was noted in the blow molding application of bottles. The previous branched polycarbonate utilizing the "TMTC" compound had provided excellent materials for the actual bottle application. However the branched polycarbonate with the new compound, THPE, was having serious problems in the field, even though it should have behaved very similarly to its predecessor branched polycarbonate. Specifically in making one gallon containers with branched bisphenol-A polycarbonate utilizing 0.40 mole percent THPE, based on the moles of bisphenol-A present in the polycarbonate, the branched polycarbonate did not process up to performance specifications arrived at using the earlier commercial TMTC branched bisphenol-A polycarbonates. Problems such as entrapped bubbles in the bottles, haze due to flow lines, as well as irregular parisons were observed.
A new formulation was devised to overcome these problems. This formulation utilized a smaller amount THPE. Such formulation did not encounter the previously observed problems with the higher portion of THPE.
SUMMARY OF THE INVENTION
In accordance with the invention there is a composition comprising a randomly branched aromatic polycarbonate wherein the branching agent is 1,1,1-tris- ( 4-hydroxyphenyl ) ethane, present in from about 0.28 to about 0.36 mole percent based on the moles of dihydric phenol present in the aromatic polycarbonate.
DETAILED DESCRIPTION OF THE INVENTION
The method of making the high molecular weight randomly branched polycarbonates is well known in the art. References which show the art accepted methods in making the randomly branched polycarbonates are disclosed in the Reissue 2,7682: U.S. Pat. No. 4,415,722: U.S. Pat. No. 4,415,723: U.S. Pat. No. 4,415,724 and U.S. Pat. No. 4,415,725. The disclosures of each of these references is incorporated by reference in this patent application. In the preparation of the novel randomly branched aromatic carbonate polymers of this invention, the amount of THPE which is utilized in the synthesis of the resin is sufficient to provide in general from about 0.28 to about 0.36 mole percent in the branched polycarbonates, is measured by the dihydric phenol which is present. The amount of THPE is preferably about 0.30 to about 0.34 percent.
The dihydric phenols which are in general reacted with the carbonate precursor and THPE in preparing the randomly branched polycarbonates are well known and are disclosed in the references identified above particularly in reissued 27682 at column 4, line 19 to column 5, line 22 and U.S. Pat. No. 4,415,722 at column 3, line 35 to line 60. Bisphenol-A is preferred.
The carbonate precursor employed can generally be a carbonyl chloride or a haloformate. When utilizing a melt polymerization an aryl carbonate such as diphenyl carbonate can be employed. Thus the carbonyl halide can be carbonyl chloride, carbonyl bromide and mixtures thereof. The haloformates suitable for use include mono or bishaloformates of dihydric phenols (bischloroformates of hydroquinone, monochloroformate of bisphenol-A, etc. ) or bishaloformates of glycols (bishaloformates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc. ). When using bishaloformates equimolar amounts of free dihydric phenols are required to affect polymerization. When polymerizing monohaloformates of diphenols no free diphenols are required. While other carbonate precursors will occur to those skilled in the art, carbonyl chloride, also known as phosgene, is preferred.
Various conventional processing techniques are known in the art to prepare the randomly branched polycarbonates, for example, interfacial solution or melt polymerization. Interfacial polymerization is preferred.
Generally the interfacial polymerization occurs with the utilization of interfacial or phase transfer catalysts. Suitable catalysts include tertiary amines such as triethylamine, tripropylamine, N,N-dimethylanaline and the like. Quaternary ammonium compounds such as tetraethylammonium chloride, cetyl triethylammonium bromide and the like can also be employed.
The specific utility for which randomly branched aromatic polycarbonates of this invention are utilized is in blow molding applications. Bottles in particular are the preferred application. An even more preferred application is a one gallon container blow molded.
In the example below the randomly branched polycarbonate which is substantially free of crosslinking is prepared in the standard manner. In the examples a 0.40 mole percent THPE level was used in the comparison example while a 0.34 mole percent level THPE was used in the example of the invention.
EXAMPLE
A standard 0.40 mole percent randomly branched bisphenol-A polycarbonate with THPE as a branching agent was blow molded into one gallon containers. The containers had productivity issues as illustrated by the entrapment of bubbles in the resin as well as haze due to flow lines and irregularly shaped parisons. The one gallon bottles were then prepared from a randomly branched bisphenol-A polycarbonate having a 0.34 mole percent level of THPE. The prior problems were not observed to any great extent and the bottle was found to be acceptable for marketing purposes. There was nothing predictable about the usage of lower levels of branching agent in the randomly branched aromatic polycarbonate to bring about the removal of the observed problems.
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A composition comprising a randomly branched aromatic polycarbonate polymer wherein the branching agent 1,1,1-tris-(4-hydroxyphenol)ethane is present in the polymer in quantities ranging from about 0.28 to about 0.36 mole percent compound based on the percent of dihydric phenol present in the polymer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Application No. 2002-2340, filed Jan. 15, 2002, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates in general to a refrigerator, and more particularly, to a refrigerator assembly unit improving a rotation of a door against a cabinet.
[0004] 2. Description of the Related Art
[0005] A refrigerator normally has a cabinet forming a refrigerator compartment, and a door provided in front of the refrigerator compartment to open and close the refrigerator compartment. The cabinet and the door are connected by a hinge member.
[0006] The hinge member includes a hinge bracket having a first end connected to the cabinet, and a second end connected to the door and provided with a hinge hole, and a hinge pin connected with the door through the hinge hole. Thus, the door rotates against the cabinet on an axis of the hinge pin.
[0007] To allow a user to put food into the refrigerator compartment or remove food therefrom, the door is generally rotated over a right angle to open the refrigerator compartment. Herein, the location of the hinge pin is significant as follows.
[0008] [0008]FIG. 7 illustrates a rotation of a door when a hinge pin is positioned at a rear corner of the door, namely, adjacent to a cabinet. As illustrated therein, a door 120 opens and closes a refrigerator compartment 110 a , being rotated on the axis of a hinge pin 135 .
[0009] However, in the case that the hinge pin 135 is positioned as illustrated in FIG. 7, when the door 120 is fully rotated, a corner part of the door 120 positioned in front of the hinge pin 135 protrudes over the outer wall of the cabinet 110 , thereby creating an interference part “I 1 ”. Thus, the refrigerator is required to be disposed at a position spaced apart from a wall, a sink, etc., to avoid the interference part “I 1 ”.
[0010] Contrary to the hinge pin 135 of FIG. 7, FIG. 8 illustrates the rotation of the door when the hinge pin 235 is positioned at the front corner of the door 220 . As illustrated therein, a door 220 also opens and closes a refrigerator compartment 210 a by being rotated at the axis of a hinge pin 235 .
[0011] In the case that the hinge pin 235 is positioned as illustrated in FIG. 8, when the door 220 is rotated, a corner part of the door 220 does not protrude over the cabinet 210 as compared with the case of FIG. 7.
[0012] However, as the hinge pin 235 is positioned at the front corner of the door 220 , the rotational radius of the door 220 is lengthened, thereby creating an interference part “I 2 ” between a door shelf 240 provided on the inside of the door 220 and an inside wall of the cabinet 210 . Thus, in order to remove the interference part “I 2 ”, the size of the door shelf 240 is required to be decreased, thereby lowering the capacity of the door shelf 240 .
SUMMARY OF THE INVENTION
[0013] Accordingly, it is an object of the present invention to provide a refrigerator that avoids the necessity of lowering the capacity of a door shelf and that avoids an interference part usually present while the door is rotated.
[0014] Additional objects and advantages of the invention 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 invention.
[0015] The foregoing and other objects of the present invention may be accomplished by providing a refrigerator comprising: a cabinet forming a refrigerator compartment; a door opening and closing the refrigerator compartment; and a hinge member rotatably connecting the door to the cabinet, and having a rotation axis varying in position depending on rotation angles of the door between a full open position at which the refrigerator compartment is fully opened and a closed position at which the refrigerator compartment is closed.
[0016] Preferably, the hinge member comprises: a hinge bracket having a first end provided with a plurality of elongated holes and connected to the door; a second end connected to the cabinet; and a plurality of hinge pins connected to the door through the plurality of elongated holes of the hinge bracket, respectively.
[0017] In one aspect of the invention, the hinge member further comprises a bracket cover covering the hinge member.
[0018] Further, the plurality of hinge pins include three pins, and the plurality of elongated holes comprises: a first elongated hole guiding a first hinge pin therein when the door is rotated from the closed position to the fully open position; a second elongated hole having an arc shape, spaced from the first elongated hole, and guiding the second hinge pin therein on the axis of the moved first hinge pin; and a third elongated hole having a radius of curvature larger than that of the second elongated hole, positioned outside the second elongated hole, and guiding a third hinge pin therein.
[0019] Further, the radius of curvature of the third elongated hole partially varies depending on the rotation angles of the door.
[0020] In another aspect of the invention, the rotation axis of the door moves from the second pin to the first pin according to the rotation angle of the door as it increases from the closed position to the full open position.
[0021] In yet another aspect of the invention, the first elongated hole is positioned at a corner of the hinge bracket connected to the door in a radial direction of the second and third elongated holes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0023] [0023]FIG. 1 is a perspective view of a refrigerator according to an embodiment the present invention;
[0024] [0024]FIG. 2 is an exploded perspective view of a hinge part of the refrigerator of FIG. 1;
[0025] [0025]FIG. 3 is a partial sectional view of the refrigerator of FIG. 1 schematically illustrating rotation of a door thereof;
[0026] [0026]FIGS. 4 through 6 illustrate operations of the hinge member according to rotation angles of the door in the refrigerator of FIG. 1; and
[0027] [0027]FIGS. 7 and 8 are schematic sectional views of a conventional refrigerator for illustrating the rotations of a door according to positions of a hinge pin, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
[0029] As illustrated in FIG. 1, a refrigerator according to an embodiment of the present invention comprises a cabinet 10 forming a refrigerator compartment 10 a , and a door 20 provided in front of the refrigerator compartment 10 a (see FIG. 3) to open and close the refrigerator compartment 10 a.
[0030] The cabinet 10 and the door 20 are connected by hinge members 30 provided at the top and bottom of the cabinet 10 . The hinge member 30 operates as a rotation axis of the door 20 . Herein, the rotation axis moves in correspondence to rotation angles of the door 20 rotating between a full open position at which the refrigerator compartment 10 a is fully opened and a closed position at which the refrigerator compartment 10 a is closed.
[0031] As illustrated in FIG. 2, the hinge member 30 includes a hinge bracket 31 having first and second ends each connected to the door 20 and the cabinet 10 , respectively, a plurality of hinge pins 35 a ˜ 35 c to connect the hinge bracket 31 to the door 20 , and a bracket cover 37 covering the hinge bracket 31 and the hinge pins 35 a ˜ 35 c.
[0032] On the first end of the hinge bracket 31 to be connected to the door 20 is provided a plurality of elongated holes 31 a ˜ 31 c , and on the second end of the hinge bracket 31 to be connected to the cabinet 10 is provided a plurality of through holes 33 . On the cabinet 10 is provided a plurality of screw holes 10 b in correspondence with the through holes 33 of the hinge bracket 31 . Thus, the second end of the hinge bracket 31 is connected to the cabinet 10 by screw-coupling bolts 39 screwed into the screw holes 10 b of the cabinet 10 through the through holes 33 of the hinge bracket 31 .
[0033] On the door 20 is provided a plurality of through holes 20 a in correspondence with the elongated holes 31 a ˜ 31 c of the hinge bracket 31 . Thus, the hinge pins 35 a ˜ 35 c are inserted into the through holes 20 a of the door 20 through the elongated holes 31 a ˜ 31 c of the hinge bracket 31 to thereby enable the door 20 to rotate while centering around at least one of the hinge pins 35 a ˜ 35 c.
[0034] It is an aspect of the invention that three elongated holes 31 a ˜ 31 c are provided on the first end of the hinge bracket 31 and three hinge pins 35 a ˜ 35 c are each inserted in the three elongated holes 31 a ˜ 31 c , respectively. Hereinbelow, the first, second and third elongated holes 31 a ˜ 31 c and the first, second and third hinge pins 35 a ˜ 35 c will be described in more detail.
[0035] The first elongated hole 31 a is relatively short and diagonally elongated at one corner of the hinge bracket 31 . The second elongated hole 31 b is spaced from the first elongated hole 31 a , forming an arc. The third elongated hole 31 c is spaced from the second elongated hole 31 b at the outside thereof, forming an arc having a radius of curvature larger than that of the second elongated hole 31 b.
[0036] The first hinge pin 35 a is accommodated in the first elongated hole 31 a and diagonally moves in the first elongated hole 31 a when the door 20 is rotated between the closed position and the full open position. The second hinge pin 35 b is accommodated in the second elongated hole 31 b and moves within the second elongated hole 31 b when the door is rotated on the axis of the first hinge pin 35 a. The third hinge pin 35 c is accommodated in the third elongated hole 31 c and guided by the third elongated hole 31 c according to the movement of the first and second hinge pins 35 a and 35 c.
[0037] With the above configuration, the rotation of the door 20 will be described hereinbelow while referring to FIG. 3 through 6 .
[0038] In the closed position at which the door 20 closes the refrigerator compartment 10 a , the first, second and third hinge pins 35 a , 35 b and 35 c are, as illustrated in FIG. 4, positioned at “A” of the first elongated hole 31 a , “B” of the second elongated hole 31 b , and “C” of the third elongated hole 31 c , respectively.
[0039] When the door 20 is rotated at an angle of θ 1 (e.g., approximately 20°), the first and third hinge pins 35 a and 35 c , as illustrated in FIG. 5, move from “A” to “A 1 ” in the first elongated hole 31 a , and from “C” to “C 1 ” in the third elongated hole 31 c , respectively. However, the second hinge pin 35 b is still at “B”. That is, when the door 20 is rotated at an angle of θ 1 (e.g., approximately 20°), the first and third hinge pins 35 a and 35 c move on the axis of the second hinge pin 35 b within the first and third elongated holes 31 a and 31 c , respectively. Herein, in the third elongated hole 31 c corresponding with the third hinge pin 35 c , an arc from “C” to “C 1 ” and an arc from “C 1 ” to “C 2 ” (FIG. 6) are different in a radius of curvature.
[0040] When the door 20 is further rotated at an angle of θ 2 (e.g., approximately 135°) from the state of FIG. 5 to the full open position, the second and third hinge pins 35 b and 35 c , as illustrated in FIG. 6, move from “B” to “B 1 ” in the second elongated hole 31 b , and from “C 1 ” to “C 2 ” in the third elongated hole 31 c on the axis of the first hinge pin 35 a positioned at “A 1 ”, respectively.
[0041] As described above, in the hinge member 30 according to an embodiment of the present invention, the rotation axis of the door 20 moves between the second hinge pin 35 b and the first hinge pin 35 a so as to shorten the radius of the rotation of the door 20 . Therefore, there is no need to decrease the capacity of a door shelf 40 . Moreover, even if the door 20 is completely opened, a corner part of the door 20 is prevented from protruding over the cabinet 10 , thereby removing the interference part.
[0042] On the other hand, the rotation of the door 20 from the full open position to the close position is performed in the reverse order to the above-described rotation.
[0043] In the above description, the hinge part 30 provided at the top of the right door 20 in FIG. 1 has been described in more detail. It will be fully appreciated that a hinge member provided at the bottom of the right door or hinge members provided at the left door may have a similar configuration.
[0044] As described above, the present invention provides a refrigerator avoiding the necessity of lowering the capacity of a door shelf so as to open a door and avoiding an interference part present while the door is rotated.
[0045] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A refrigerator having a cabinet forming a refrigerator compartment; a door opening and closing the refrigerator compartment; and a hinge member rotatably connecting the door to the cabinet. The hinge member has a rotation axis varying in position, depending on rotation angles of the door between a full open position at which the refrigerator compartment is fully opened and a closed position at which the refrigerator compartment is closed.
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BACKGROUND OF INVENTION
[0001] This invention relates generally to steam turbines, and more particularly, to controlling steam leakage paths in the turbine
[0002] A steam turbine may include a high-pressure (HP) turbine section, an intermediate-pressure (IP) turbine section, and a low-pressure (LP) turbine section that each include rotatable steam-turbine blades fixedly attached to, and radially extending from, a steam-turbine shaft that is rotatably supported by bearings. The bearings may be located longitudinally outwardly from the high and intermediate-pressure turbine sections. A steam pressure drop through at least some known high-pressure and/or intermediate-pressure turbine sections is at least about 2,000 kPa (kiloPascals), and a difference in pressure of the steam entering the high and intermediate-pressure turbine sections is at least about 600 kPa. In some known steam turbines, steam exiting the HP turbine section is reheated by a boiler before entering the IP turbine section.
[0003] A steam turbine has a defined steam path which includes, in serial-flow relationship, a steam inlet, a turbine, and a steam outlet. Steam leakage, either out of the steam path, or into the steam path, from an area of higher pressure to an area of lower pressure, may adversely affect an operating efficiency of the turbine. For example, steam-path leakage in the turbine between a rotating rotor shaft of the turbine and a circumferentially surrounding turbine casing, may lower the efficiency of the turbine leading to increased fuel costs. Additionally, steam-path leakage between a shell and the portion of the casing extending between adjacent turbines, for example, a high pressure turbine section to an adjacent intermediate turbine section, may lower the operating efficiency of the steam turbine and over time, may lead to increased fuel costs.
[0004] To facilitate minimizing steam-path leakage between the HP turbine section and a longitudinally-outward bearing, and/or between the IP turbine section and a longitudinally-outward bearing, at least some known steam turbines use a plurality of labyrinth seals. Such labyrinth seals include longitudinally spaced-apart rows of labyrinth seal teeth. Many rows of teeth are used to seal against the high-pressure differentials that may be in a steam turbine. Brush seals may also be used to minimize leakage through a gap defined between two components, such as leakage that is flowing from a higher pressure area to a lower pressure area. Brush seals provide a more efficient seal than labyrinth seals, however, at least some known steam turbines, which rely on a brush seal assembly between turbine sections and/or between a turbine section and a bearing, also use at least one standard labyrinth seal as a redundant backup seal for the brush seal assembly.
[0005] Other areas of steam path leakage within a turbine may affect adversely turbine efficiency. One such area is a casing fit between the HP turbine section and the IP section where labyrinth and brush seals are impractical.
SUMMARY OF INVENTION
[0006] In one aspect, a method of assembling a steam turbine is provided. The method includes positioning a first sealing member in a leakage path defined between an inner casing and an outer casing such that leakage flow in a first direction activates the first sealing member, and positioning a second sealing member in the leakage path such that leakage flow in the first direction bypasses the second sealing member, and such that leakage flow in an opposite second direction activates the second sealing member.
[0007] In another aspect, a seal assembly for sealing a leakage path is provided. The seal assembly includes a first groove defined in a channel, a second groove defined in the channel and substantially parallel to the first groove wherein the second groove is defined radially outward from the first groove, a divider positioned in the channel such that a gap defined between the divider and the channel defines a leakage path, a first sealing member that extends at least partially within the first groove and positioned to substantially prevent a flow within the leakage path in a first direction, and a second sealing member that extends at least partially within the second groove and positioned to substantially prevent a flow within the leakage path in a second direction, the second direction being opposite to the first direction.
[0008] In yet another aspect, a rotary machine is provided. The rotary machine includes a rotor rotatable about a longitudinal axis and including an outer annular surface, an annular outer casing including an inner surface wherein the outer casing is spaced radially outwardly from the rotor, the casing inner surface includes a first extension extending radially inwardly towards the rotor, and the first extension extends circumferentially about the casing inner surface. The rotary machine also includes a cylindrical inner casing includes an outer surface wherein the outer surface includes a second extension extending radially towards the outer casing, and the second extension extends circumferentially about the outer surface, and the second extension includes a channel in an outer extension surface for receiving the first extension when the outer casing and the inner casing are assembled, a first groove formed in said channel sized to receive a sealing member, and a sealing member positioned at least partially within the first groove for sealing a leakage path.
BRIEF DESCRIPTION OF DRAWINGS
[0009] [0009]FIG. 1 is a schematic illustration of an exemplary opposed flow HP/IP steam turbine;FIG. 2 is an enlarged schematic illustration of a section divider and mating channel that may be included in the steam turbine shown in FIG. 1.
[0010] [0010]FIG. 3 is an enlarged view of the section divider shown in FIG. 1 and taken along area 3 .
DETAILED DESCRIPTION
[0011] [0011]FIG. 1 is a schematic illustration of an exemplary opposed-flow steam turbine 10 including a high pressure (HP) section 12 and an intermediate pressure (IP) section 14 . A single outer shell or casing 16 is divided axially into upper and lower half sections 13 and 15 , respectively, and spans both HP section 12 and IP section 14 . A central section 18 of shell 16 includes a high pressure steam inlet 20 and an intermediate pressure steam inlet 22 . Within outer shell or casing 16 , HP section 12 and IP section 14 are arranged in a single bearing span supported by journal bearings 26 and 28 . A steam seal unit 30 and 32 is located inboard each journal bearing 26 and 28 , respectively.
[0012] An annular section divider 42 extends radially inwardly from central section 18 and towards a rotor shaft 44 extending between HP section 12 and IP section 14 . More specifically, divider 42 extends circumferentially around a portion of shaft 44 extending between first HP section nozzle 46 and a first IP section nozzle 48 . Section divider 42 is received in a channel 50 formed in packing casing 52 . Channel 50 is a C-shaped channel that extend radially into packing casing 52 and around an outer circumference of packing casing 52 , such that a center opening of channel 50 faces radially outwardly. Channel 50 includes a pair of seal grooves 54 and 56 positioned in a radially extending surface 57 of channel 50 . Seal grooves 54 and 56 are co-axial about a longitudinal axis 58 of turbine 10 . In an alternative embodiment, section divider 42 includes a pair of seal grooves 54 and 56 positioned in a radially extending surface 59 of section divider 42 .
[0013] In operation, high pressure steam inlet 20 receives high pressure/high temperature steam from a source, for example, a power boiler (not shown). The steam is routed through HP section 12 wherein work is extracted from the steam to rotate rotor shaft 44 . The steam exits HP section 12 and returns to the boiler where it is reheated. The reheated steam is then routed to intermediate pressure steam inlet 22 and returned to IP section 14 at a reduced pressure than steam entering HP section 12 , but at a temperature that is substantially similar to the steam entering HP section 12 . Accordingly, an operating pressure within HP section 12 is higher than an operating pressure in IP section 14 . Therefore, steam within HP section 12 tends to flow towards IP section 14 through leakage paths that may develop between HP section 12 and IP section 14 . One such leakage path may be defined along a rotor 44 extending through packing casing 52 . Accordingly, packing casing 52 includes a plurality of labyrinth and/or brush seals to facilitate reducing leakage from HP section 12 to IP section 14 along a shaft 60 . Another leakage path between HP section 12 and IP section 14 is through a gap between section divider 42 and packing casing 52 in channel 50 .
[0014] [0014]FIG. 2 is an enlarged schematic illustration of a section divider 42 and channel 50 that may be included in steam turbine 10 . Section divider 42 includes a first side 102 , a sealing side 104 , and a joining side 106 . Channel 50 includes a first side 112 , a sealing side 114 , and a joining side 116 . First sides 102 and 112 of section divider 42 and channel 50 , respectively, correspond with each other in a mating fashion when section divider 42 and channel 50 are coupled. Sealing sides 104 and 114 , and joining sides 106 and 116 , similarly mate together when section divider 42 and channel 50 are coupled. Since sides 102 , 104 , and 106 do not mate exactly to sides 112 , 114 , and 116 , a plurality of gaps 117 , 118 , and 119 are formed between corresponding sides, 102 and 112 , 106 and 116 , and 104 and 114 , respectively. More specifically, each gap 117 , 118 , and 119 form a potential steam flow leakage path 120 from HP section 12 towards IP section 14 . During some known conditions, such as a trip of turbine 10 , an operating pressure in IP section 14 may exceed the pressure HP section 12 and in such a condition, the flow in leakage path 120 would tend to reverse and flow from IP section 14 towards HP section 12 . To facilitate reducing leakage flow through leakage path 120 , a dual opposing seal assembly 122 is provided in seal side 114 . In an alternative embodiment, the dual opposing seal may be provided in surface 59 of divider 42 .
[0015] Two parallel grooves 54 and 56 are formed in seal side 114 and grooves 54 and 56 are each sized to receive a sealing member 154 and 156 , respectively, therein. More specifically, seal assembly 122 includes members 154 and 156 , and is a pressure activated sealing member that is configured such that a pressure being sealed provides a motive force to cause the sealing member to seal tighter as pressure applied to the sealing member increases. In the exemplary embodiment, sealing members 154 and 156 are V-seals, such that each has a V-shaped cross-sectional profile. In other embodiments, sealing members 154 and 156 are known C-seals, E-seals, or W-seals.
[0016] In operation, steam at higher pressure in HP section 12 tends to leak through steam path 120 to IP section 14 , which is at a lower steam pressure. Sealing members 154 and 156 seated in grooves 54 and 56 respectively, activate to facilitate limiting or stopping steam leakage flow through leakage path 120 .
[0017] [0017]FIG. 3 is an enlarged view of section divider 42 taken along area 3 . More specifically, FIG. 3 is an enlarged view of seal assembly 122 . Section divider 42 is coupled to packing casing 52 such that corresponding sides 106 and 116 are proximate each other, and corresponding sides 104 and 114 are proximate each other. Gaps 119 and 118 are defined between sides 104 and 114 , and between sides 106 and 116 , respectively. Gaps 119 and 118 permit steam from HP section 12 to leak toward IP section 14 through leakage path 120 during operation of turbine 10 . A second leakage path 200 is a reverse flow path that may occur during some turbine operations, such as, for example, a turbine trip. To facilitate reducing or eliminating steam leakage through paths 120 and 200 , sealing members 154 and 156 are positioned in grooves 54 and 56 in side 114 . Each seal groove 54 and 56 is defined by a groove depth 201 and a groove width 202 . In the exemplary embodiment, each groove depth 201 and groove width 202 are between approximately 0 . 2 inches and approximately 0 . 5 inches. In the exemplary embodiment, sealing members 154 and 156 are V-seals. More specifically, each sealing member 154 and 156 has a cross-sectional profile including an apex 204 and a pair of opposed legs 206 and 208 that diverge from apex 204 . Legs 206 and 208 form an interior surface 210 and an exterior surface 212 . Sealing members 154 and 156 are sized such that at least a portion of leg 208 extends past side 114 into leakage paths 120 and 200 such that when section divider 42 and channel 50 are coupled, leg 208 at least partially engages side 104 .
[0018] Sealing members 154 and 156 are fabricated from a material that provides flexibility at apex 204 and rigidity of legs 206 and 208 to withstand a pressure differential across legs 206 and 208 . In the exemplary embodiment, members 154 and 156 withstand a pressure differential of at least approximately 600 kPa. In the exemplary embodiment, sealing members 154 and 156 are fabricated from rolled sheet metal having a thickness of between about 0.005 inches and 0.030 inches. In other embodiments, sealing members 154 and 156 are fabricated from materials such as, for example, Hastelloy ®, Cres 304 , and Incoloy 909 ®. Sealing members 154 and 156 are positioned in their respective grooves 54 and 56 such that apexes 204 point toward each other, giving sealing members 154 and 156 an opposed configuration with respect to each other. In another embodiment, sealing members 154 and 156 are E, W, or C seals wherein the open side of each E, W, or C face away from each other. In one embodiment, sealing members 154 and 156 are commercially available from Jetseal, Inc. of Spokane, Washington. In the exemplary embodiment, sealing members 154 and 156 are identical to each other. In another embodiment, sealing members 154 and 156 are different.
[0019] In operation, steam from HP section 12 attempts to flow to lower pressure IP section 12 during normal operation of turbine 10 . As steam flows through leakage path 120 , the steam contacts sealing member interior surface 210 . Leg exterior surface 212 contacts side 104 due to the flexibility of apex 204 and thus provides a bias to leg 208 . A distal end 214 of leg 208 blocks steam flow from leakage path 120 and directs the steam towards an area 220 defined within interior surface 210 of sealing member 154 . A differential pressure builds up across sealing member 154 due to steam from HP section 12 becoming trapped in area 220 and leakage path 120 downstream of sealing member 154 still being in communication with IP section 14 . The differential pressure across sealing member 154 causes legs 206 and 208 to expand outwardly further tightening the contact between exterior surface 212 of sealing member 154 and side 104 .
[0020] During operations when the differential pressure tends to reverse, for example during a turbine trip event, sealing member 156 will activate to block leakage path 200 in a manner similar to that of sealing member 154 blocks leakage flow through path 120 during normal turbine operations. Thus, a double seal arrangement in an area of the steam turbine where surface irregularities may provide a leakage path from HP section 12 to IP section 14 facilitates reducing leakage through path 120 during normal operation of turbine 10 and during upsets when steam flow may reverse.
[0021] The above-described turbine casing seal arrangement is cost effective and highly reliable. The double seal arrangement includes a first sealing member to facilitate reducing steam leakage through an internal leakage path in the turbine during normal operations and a second sealing member in an opposed arrangement from the first sealing member to facilitate reducing steam leakage in an opposite direction through an internal leakage path in the turbine during other than normal operations. As a result, the turbine casing seal arrangement facilitates reducing steam leakage in a turbine during a plurality of modes of operation in a cost effective and reliable manner.
[0022] Exemplary embodiments of turbine casing seal arrangements are described above in detail. The arrangements are not limited to the specific embodiments described herein, but rather, components of the system may be utilized independently and separately from other components described herein. Each turbine casing seal arrangement component can also be used in combination with other turbine casing seal arrangement components.
[0023] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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A method and apparatus for sealing between an inner casing and an outer casing is provided. The method includes positioning a first sealing member in a leakage path defined between an inner casing and an outer casing such that leakage flow in a first direction activates the first sealing member, and positioning a second sealing member in the leakage path such that leakage flow in the first direction bypasses the second sealing member, and such that leakage flow in an opposite second direction activates the second sealing member. The apparatus includes a pair of circumferential grooves in a channel, a divider positioned in the channel that defines a leakage path, a first sealing member positioned to seal against a flow in the leakage path in a first direction, and a second sealing member positioned to seal against a flow in the leakage path in a second direction.
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[0001] The present invention relates to the fields of analytical chemistry and medicine. In particular the present invention refers to calixpyrrole compounds useful as ionophores, to membranes, electrodes, and devices including them as well as to methods for determining the amount of creatinine in a test sample using them.
BACKGROUND ART
[0002] Creatinine is a normal metabolic by-product generated by the cells. Since its accumulation is toxic, creatinine is transported by the bloodstream to the kidneys to be filtered out and excreted through the urine. For this reason, the levels of creatinine in blood or urine are key parameters used to evaluate proper kidney function. Creatinine levels are used to calculate the glomerular filtration rate (GFR), a magnitude used to assess the performance of the kidneys. The normal levels of creatinine in blood, which depend on age and sex, are well established. High levels of creatinine reflect a disease or a condition affecting the kidneys -such as infections, illnesses, chronic failures, etc.- that may lead from mild to severe health risks, and even death. For example, in chronic kidney failures creatinine levels must be carefully and frequently checked, since they are used to determine when the haemodialysis treatment must be performed. Creatinine clearance is also required before many medical treatments, such as chemotherapy. Additionally, in urine analysis, creatinine is used as normalization factor to minimize the variability due to volume dilution. The literature deals with many more examples where the determination of creatinine in biological fluids and clinical samples is important. All in all, the precise determination of the levels of creatinine in biological fluids, particularly blood and urine, is extremely relevant. For this reason, it is one of the most commonly required determinations in the routine of the clinical laboratories.
[0003] Several approaches for the determination of creatinine have been reported. Colorimetric methods are the most widely used. The foundation of most of these methods is based on the Jaffé reaction—described more than a century ago-, which consists in a specific reaction under strong basic conditions between creatinine and picric acid that yields a coloured compound that can be measured colorimetrically at 505 nm. Variations on this method are also used for the routine determination of creatinine in the clinical lab. Other colorimetric methods are based on the use of creatinine amidohydrolase (EC 3.5.2.10).
[0004] However, colorimetric methods are not free from interferences. From one side, the response depends strongly on the colour of the sample. Turbidity or highly coloured samples may lead to significant errors. Other molecules that can affect the development of the colour may also act as chemical interferences. For example, it has been demonstrated that substances such as acetone, cefazolin, cefoxitin, ceftiofur and glucose can lead to positive biased results, while acetoacetic acid, bilirubin and lipids can yield a negatively biased values in serum measurements (Jacobs, R. M. et al., 1991). Therefore, although universally used, colorimetric methods are not free of analytical and practical problems.
[0005] Today, the gold standard for the determination of creatinine is the isotope dilution gas chromatography—mass spectrometry (ID-GC-MS), since it provides highly accurate results. Nevertheless, this method requires an expensive and complex instrumentation and suitable degree of expertise for the operation. All in all, despite the optimal performance, due to problems associated to cost, simplicity and availability, ID-GC-MS is a good referee method, but it cannot be yet considered a viable routine approach in the clinical laboratory and even less a viable solution for point of care.
[0006] In view of the above, several alternative electrochemical methods have been reported in an attempt to develop a viable routine method for determining the level of creatinine. Among them, amperometric biosensors are the most common electrochemical methods so far. These biosensors mainly rely on a three-enzyme method, which involves a three-stage conversion of creatinine to creatine, creatine to sarcosine and sarcosine to glycine. At the end, the generation of H 2 O 2 produced during the last stage is monitored. This type of approach is common to amperometric systems. Immobilization of these enzymes has been studied for decades, and a portable clinical analyzer called iSTAT® is already in the market where the enzymes are immobilized on cartridges that are commercially available. However, these enzyme-based methods are not free of interferences (Dimeski, C. et al., 2010). Furthermore, the complex combination of enzymes requires careful storage and manipulation of the sensors. It has been disclosed that iSTAT has not shown an appropriate sensitivity for creatinine.
[0007] Another electrochemical alternative is based on potentiometric methods, which have become attractive because of their simplicity of operation, robustness, and cost-effectiveness. For this reason, they are ideal tools for point-of-care and other out-of-the-lab measuring approaches. Indirect biosensors for creatinine based on the enzymatic hydrolysis of creatinine and the potentiometric detection of a reaction by-product (pH, ammonium ions, etc) have been described by some researchers, such as Rechnitz (Meyerhoff, M., 1976). However, the use of enzymes makes difficult the storage and conditioning of the analytical devices.
[0008] To avoid all these problems associated to the use of enzymes or other biological compounds, direct potentiometric sensors are preferred. In this case, the solution containing creatinine must be adjusted to a suitable pH in order to turn creatinine into the protonated form—the creatininium ion. Buhlmann and co-workers introduced an ionophore-free ion-selective electrode by incorporating chloroparaffin as plasticizer for the direct determination of creatinine. This sensor shows good performance in synthetic samples. However, when dealing with the determination of creatinine in real samples, they observed a serious fouling coming from electrically neutral lipids that affected the measurements (Bühlmann, P., 2001) and hindered the applications. To reduce this biofouling, a polymeric membrane with fluorinated compounds was proposed. However, the selectivity obtained using these approaches is not enough for the determination of creatinine in real samples. To improve the selectivity of potentiometric sensors, the best approach is to use synthetic receptors (ionophores) to entrap creatinine using host-guest based chemistry. Few macromolecules have been reported so far as new receptors for creatinine. Nevertheless, none of them meets the analytical performance (such as limit of detection, stability, selectivity coefficients, among others) required for the determination of creatinine in real samples (Hassan, S. S. M., 2005).
[0009] In summary, all the methods used nowadays in routine analysis for the determination of creatinine suffer from drawbacks in the analytical performance, related in particular to selectivity, re-usability, accuracy and ease of implementation (portability). Alternative approaches reported up to date in the literature, such as potentiometric sensors, fail to meet the analytical performance required to be applied in real samples.
[0010] Therefore, there is still the need of sensors able of detecting selectively creatinine which can alleviate many current problems in the clinical laboratories and open new opportunities in fields such as telemedicine and point of care diagnosis.
[0011] The state of the art discloses many calixpyrroles. In Ballester Petal., 2012 there are disclosed stereoisomers of the calix[4]pyrroles:
[0000]
[0012] In addition, Galán A. et al., discloses the calix[4]pyrrole:
[0000]
[0000] where R 9 is C 12 H 23 .
SUMMARY OF THE INVENTION
[0013] The present inventors have developed new calixpyrrole compounds which are useful as creatinine ionophores. As shown below, when a calixpyrrole such as those disclosed herein is used as ionophore in the manufacture of a sensor, it is found that the resulting sensor shows high selectivity for creatinine in front of other ions (interferences) present in real samples. Therefore, the use of this novel ionophores minimizes the drawbacks produced by typical interferences, such as K + .
[0014] In Buhlman et al., 2001, wherein the use of membranes with a specific polymeric matrix composition is used, there was the need for changes on said polymeric matrix composition in order to get some selectivity for creatinine. However, these membranes showed biofouling problems and could not be used in the detection of creatinine in real samples because they were not selective enough.
[0015] The present inventors have found that using the compounds of the present invention as ionophores in the manufacture of a membrane, it is observed a minimization of the biofouling as well as a long-term stability of the electrode. FIG. 1 is illustrative of the fact that the compounds of the invention provide good sensitivity, since they allow the detection of the analyte at very low concentrations.
[0016] The findings provided by the present inventors means a great advance in the field of clinical analysis because it is the first time that an ionophore can be formulated in a membrane for the potentiometric detection of creatinine in a real sample, the membrane meeting the analytical performance, such as limit of detection, stability, selectivity coefficients, among others (see Table 3 below) required for the determination of creatinine in real samples.
[0017] The fact that the compounds of the present invention confer to sensors the selectivity and usability in potentiometric methods means a great advance in the clinical analysis because (a) the determination is performed in a fast and simple way since no special treatment of the sample is required prior to the determination and no special reagents (such as enzymes) are necessary in the detection; (b) the required volume of sample is very low; (c) the materials needed for the potentiometric method are cheap (the support of the membrane can be a paper sheet for instance); (d) as not being required the use of enzymes, it is stable so it can be stored for long periods of time.
[0018] Thus, in a first aspect, the present invention provides a compound of formula (Ia), or alternatively (Ib) or alternatively (Ic), or any of the stereoisomers of (Ia), (Ib) or (Ic)
[0000]
[0019] wherein
[0020] R 1 is a monoradical selected from the group consisting of hydrogen; (C 1 -C 20 )alkyl; (C 3 -C 20 )alkenyl; (C 3 -C 20 )alkynyl; (C 1 -C 6 )alkyl-O—; (C 1 -C 20 )haloalkyl; (C 6 -C 20 )aryl; (C 6 -C 20 )aryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro; (C 6 -C 20 )heteroaryl; and (C 6 -C 20 )heteroaryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro; R 2 , and R 2 ′ are monoradicals each one being independently selected from the group consisting of hydrogen, (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro;
[0021] Z 1 to Z 4 are diradicals of formula (III)
[0000]
[0022] wherein A l and A 2 are independently selected from the group consisting of —O—and —NR 3 —, wherein R 3 is selected from the group consisting of hydrogen and (C 1 -C 20 )alkyl; and
[0023] G is a diradical selected from the group consisting of —NH 2 , —P(═S)(R 5 ), —S(═O) 2 —, (C 1 -C 6 )alkyl, —S(═O)—, —C(═O)—, —P(═O)(R 4 )—, —P(═O)(NR 6 R 7 )— and —P(═O)(OR 4 );
[0024] R 4 and R 5 are monoradicals independently selected from the group consisting of (C 1 -C 20 )alkyl; (C 3 -C 8 )cycloalkyl; (C 2 -C 20 )alkenyl; (C 3 -C 20 )cycloalkyl; (C 1 -C 20 )haloalkyl; (C 1 -C 20 )alkyl-O—; (C 6 -C 20 )aryl; (C 6 -C 20 )heteroaryl; (C 6 -C 20 )aryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )haloalkyl, (C 1 -C 6 )alkyl-O—, halogen, cyano, nitro; and (C 6 -C 20 )heteroaryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro;
[0025] Y 1 to Y 4 are triradicals each one independently selected from the group consisting of (C 1 -C 8 )alkyl; (C 3 -C 7 )cycloalkyl; (C 6 -C 20 )aryl; (C 6 -C 20 )aryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro; (C 6 -C 20 )heteroaryl; and (C 6 -C 20 )heteroaryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro;
[0026] R 6 and R 7 are monoradicals independently selected from the group consisting of —H and (C 1 -C 20 )alkyl;
[0027] FG 1 and FG 2 are monoradicals independently selected from the group consisting of H, OH, and NHR 8 wherein R 8 is a radical selected from the group consisting of hydrogen and (C 1 -C 20 )alkyl;
[0028] wherein
[0029] (C 6 -C 20 )aryl represents a C— radical of a ring system from 6 to 20 carbon atoms, the system comprising from 1 to 3 rings, where each one of the rings forming the ring system: is saturated, partially unsaturated, or aromatic; and is isolated, partially fused or totally fused;
[0030] (C 6 -C 20 )heteroaryl represents a C— radical of a ring system from 6 to 20 members, the system comprising from 1 to 3 rings, wherein at least one of the rings contains from one to four heteroatoms independently selected from 0, S and N, and wherein each one of the rings forming the ring system: is saturated, partially unsaturated or aromatic; and is isolated, partially fused or totally fused; and
[0031] (C 3 -C 20 )cycloalkyl refers to a saturated carbocyclic ring system from 3 to 20 carbon atom members, the system comprising from 1 to 3 rings;
[0032] provided that the compound of formula (Ib) is other than a compound of formula (IV) and stereoisomers thereof, or (V) and stereoisomers thereof, and provided that the compound of formula (Ic) is other than a compound of formula (VI):
[0000]
[0033] wherein R 9 is C 12 H 23 .
[0034] Without being bound to the theory, it is believed that the selectivity for creatinine is due to the common calixpyrrole structure having at least one bridge formed by members —Y—Z—Y—, this bridge forming a ring connecting the two non-adjacent carbon atoms to which R 1 radicals are attached.
[0035] As mentioned above, the compounds of formula (Ia), (Ib), or (Ic), or a stereoisomer thereof of the present invention can be incorporated into a suitable membrane which, as shown in the experimental data, is selective to creatininium ions.
[0036] Thus, in a second aspect the present invention provides a membrane comprising: (i) a compound of formula (Ia), (Ib), or (Ic), or a compound of formula (IV), (V), or a stereoisomer thereof, as defined above or a compound of formula (VI), (ii) a polymeric matrix; (iii) a plasticizer; and (iv) a cation-exchanger salt.
[0037] The suitable combination of all these elements (i) to (iv) produces an ion-selective membrane for the detection of creatinine which, by proper adjustment of the pH of the sample, allows the fast, selective and sensitive determination of creatinine in real samples such as urine and plasma. As shown in Example 12 below and FIGS. 1 and 2 , the sensor exhibits an almost Nernstian response (54.2±0.6 mV/log aCreatinine), a linear range from 10 −6 M to 10 −2 M of creatinine, and limits of detection typically in the range of 10 −6.2 M of creatinine
[0038] In a third aspect the present invention provides an electrode comprising the membrane as defined above.
[0039] As shown in FIG. 1 the compounds of the present invention show a short response time (when the addition of a creatinine solution was added to the medium, the electrode lasted about 10 seconds in giving the new measure of potential) and good stability because the potential signal is kept continue and constant until the addition of a new solution of creatinine at a different concentration. In addition, from FIG. 2 it can be concluded that when a sensor comprising a compound of the invention is used, there is a Nernstian response, which means that there is a linear relationship between the creatinine concentration and the signal and that, therefore, the sensor works adequately. In fact, from FIG. 2 it can be concluded that including a compound of the invention, the sensor is able of detecting concentrations of the order of 10 −6 , whereas the same membrane without such compound does not. From FIG. 2 it can also be concluded, therefore, that the inclusion of a compound of the invention confers to the sensor an appropriate sensitivity to creatinine. In view of the above, the inclusion of a compound of the invention in a sensor allows the simple and fast determination of creatinine in clinical samples, such as plasma and urine, with minimal sample manipulation.
[0040] In a fourth aspect the present invention provides a device comprising the electrode of the third aspect of the invention.
[0041] As it has been mentioned above, the compounds of the present invention allows the specific detection of creatinine ions in a test sample. Consequently, these compounds are useful in the routine determination of creatinine levels in any test sample.
[0042] Therefore, in a fifth aspect the present invention provides a method for the quantification of a creatinine in an isolated test sample comprising the step of (a) contacting the test sample with a membrane, electrode or device as defined in any of the previous aspects; and (b) correlating the potential value with the amount of creatinine comprised in the sample.
[0043] In a further aspect the present invention provides a process for preparing a compound of formula (Ia), (Ib), (Ic), or a stereoisomer thereof as defined above, wherein:
[0044] (a) when the compound is one of formula (Ia), the process comprises the reaction between a compound of formula (VII) with a compound of formula (VIII), wherein the molar ratio between the compound (VII) with respect to the compound (VIII) is comprised from 1:1 to 1:2, the reaction being performed in a basic medium
[0000]
[0045] wherein R 1 , R 2 , R 2 ′, FG 1 , FG 2 , Y 1 to Y 4 , and G are as defined above, and B 1 and B 2 are radicals independently selected from the group consisting of halogen, tosylate, triflate, nonaflate and imidazole;
[0046] (b) when the compound is one of formula (Ib), the process comprises:
[0047] b.1. the reaction between a compound of formula (VII) with the compound of formula (VIII) as defined above, being the compound of formula (VII) in a molar ratio with respect to the compound of formula (VIII) comprised from 1:2 to 1:10, the reaction being performed in a basic medium; or alternatively,
[0048] b.2. the reaction between a compound of formula (Ia) with the compound of formula (VIII) as defined above, being the compound of formula (Ia) with respect to compound of formula (VIII) in a molar ratio comprised from 1:1 to 1:6, the reaction being performed in a basic medium;
[0049] (c) when the compound is one of formula (Ic), the process comprises:
[0050] c.1. the reaction between a compound of formula (VII) with the compound of formula (VIII) as defined above, being the compound of formula (VII) with respect to the compound of formula (VIII) in a molar ratio comprised from 1:4 to 1:10, the reaction being performed in a basic medium; or alternatively,
[0051] c.2. the reaction between a compound of formula (Ia) with the compound of formula (VIII) as defined above, being the compound of formula (Ia) with respect to the compound of formula (VIII) in a molar ratio comprised from 1:3 to 1:10, the reaction being performed in a basic medium; or alternatively,
[0052] c.3. the reaction between a compound of formula (Ib) with the compound of formula (VIII) as defined above, being the compound of formula (Ib) with respect to the compound of formula (VIII) in a molar ratio comprised from 1:2 to 1:10, the reaction being performed in a basic medium.
[0053] As it has been mentioned above, the compounds of the invention are highly selective for creatinine, so when they are formulated in membrane and are placed in contact with the test sample, they selectively “trap” creatinine at the interface between the solution and the membrane. The experimental data provided below supports the fact that the sensor is selective for creatinine, even at low concentrations. This is indicative that the compounds of the invention are receptors specific for creatinine. This is indicative of the usability of the compounds of the invention as ionophore.
[0054] Therefore, in a further aspect the invention provides the use of a compound of formula (Ia), (Ib), or (Ic) as defined above thereof as ionophore.
[0055] Ballester P et al., 2012 and Galan A. et al., 2014 do not disclose that the calix[4]pyrroles disclosed therein can be used as ionophores specific for creatinine.
[0056] Therefore, in a further aspect the invention provides the use of a compound of formula (Ia), (Ib), or (Ic) or of a compound of formula (IV), (V), or a stereoisomer thereof or a compound of formula (VI) as ionophore specific for creatinine.
[0057] Finally, as it has been mentioned previously, creatinine is widely used as biomarker of several disorders. Since the compounds of the present invention show high selectivity for creatinine, they can be useful, either alone or formulated in the form of a membrane, electrode, or device, as a diagnostic/prognostic tool in creatinine-disease related disorders.
[0058] In a last aspect the present invention provides the use of a compound of formula (Ia), (Ib), or (Ic) as defined above, or of a compound of formula (IV), (V), or a stereoisomer thereof or a compound of formula (VI) for use in diagnostics or prognosis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] FIG. 1 shows the whole potentiometric time -trace up to levels of 10 mM of creatinine. Y-axis=potential (mV), X-axis=time (seconds). The solid line corresponds to the response of the creatinine ion-selective electrode described in this invention. The grey line corresponds to the unspecific response using a sensor built without ionophore. This figure illustrates the clear influence of the creatinine receptor to improve the limit of detection as well as to expand the working range of the sensor.
[0060] FIG. 2 illustrates the linear dependence for the response of the ion-selective electrode described in this invention (line, circles) and a sensor built without the ionophore (dashed line, squares) between potential (mV) as a function of the logarithm of the activity of creatinine ion in the solution. As it can be seen in this figure, the receptor for creatinine allows detecting creatinine at lower activities than without receptor.
[0061] FIG. 3 shows the potentiometric selectivity coefficients (log K Creat) required for real samples measurements (R), calculated by separate solution method and expressed as log K POT A,B , obtained for the receptor-less ion-selective electrode (B=blank) and finally the creatinine ion-selective electrode of this invention (C).
[0062] FIG. 4 illustrates the linear relationship between creatinine values obtained for urine samples potentiometrically of the invention (X axis, “P”) and the creatinine values obtained with the Jaffé colorimetric method (Y axis, “C”).
DETAILED DESCRIPTION OF THE INVENTION
[0063] All terms as used herein in this application, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present application are as set forth below and are intended to apply uniformly throughout the specification and claims unless an otherwise expressly set out definition provides a broader definition.
[0064] The calixpyrroles disclosed in the present invention show an isomerism when the “Z” dirradical comprises a G selected from —P(═O)(R 4 )—, —P(═O)(OR 4 )—, —P(═O)(NR 6 R 7 )—, and —P(═S)(R 5 )—, in such a way that the radical(s) composing G radical point either inside the structure (“in”) or outside (“out”). For instance, if G radical is a —P(═O)R 4 , the oxygen radical can be inside the structure (thus being R 4 outside), or oxygen can be outside the structure (thus being R 4 inside). This same applies to the other G radicals —P(═O)(OR 4 )—, —P(═O)(NR 6 R 7 )—, and —P(═S)(R 5 )—.
[0065] As mentioned above, the present invention provides new compounds of formula (Ia), (Ib), or (Ic) useful as creatinine ionophores.
[0066] In the present invention, the term “alkyl” refers to a linear or branched hydrocarbon chain which contains the number of carbon atoms specified in the description or the claims. Examples include, among others, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, octyl, heptyl, nonanyl, decanyl, undecanyl, dodecanyl, and tert-butyl.
[0067] In the present invention the term “alkenyl” refers to a branched or linear alkyl chain which contains the number of carbon atoms specified in the description or claims and that also contains one or two double bonds. Examples include, among others, ethenyl, 1-propen-1-yl, 1-propen-2-yl, 3-propen-1-yl, 1-buten-1-yl, 1-buten-2-yl, 3-buten-1-yl, 3-buten-2-yl, 2-buten-1-yl, 2-buten-2-yl, 2-methyl-1 -propen-1 -yl, 2-methyl-2-propen-1-yl, 1 ,3-butadien-1-yl, 1 ,3-butadien-2-yl, and dodecenyl.
[0068] The term “alkynyl” refers to refers to a branched or linear alkyl chain which contains the number of carbon atoms specified in the description or claims and that also contains one or two triple bonds.
[0069] In the present invention, the term “haloalkyl” refers to a linear or branched hydrocarbon chain which contains the number of carbon atoms specified in the description or the claims, wherein at least one of the hydrogen atoms is replaced by an halogen atom selected from F, Cl, L, and Br.
[0070] According to the present invention a ring system formed by “isolated” rings means that the ring system is formed by two, three or four rings and said rings are bound via a bond from the atom of one ring to the atom of the other ring.
[0071] The term “isolated” also embraces the embodiment in which the ring system has only one ring. Illustrative non-limitative examples of known ring systems consisting of one ring are those derived from: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, phenyl, biphenylyl, and cycloheptenyl.
[0072] According to the present invention when the ring system has “totally fused” rings, it means that the ring system is formed by two, three or four rings in which two or more atoms are common to two adjoining rings. Illustrative non-limitative examples are 1,2,3,4-tetrahydronaphthyl, 1-naphthyl, 2-naphthyl, anthryl, or phenanthryl.
[0073] According to the present invention when the ring system is “partially fused”, it means that the ring system is formed by three or four rings, being at least two of said rings totally fused (i.e. two or more atoms being common to the two adjoining rings) and the remaining ring(s) being bound via a bond from the atom of one ring to the atom of one of the fused rings.
[0074] In one embodiment of the first aspect of the invention:
[0075] R 1 is a monoradical selected from the group consisting of hydrogen; (C 1 -C 20 )alkyl; (C 3 -C 20 )alkenyl; (C 3 -C 20 )alkynyl; (C 1 -C 6 )alkyl-O—; (C 1 -C 20 )haloalkyl;
[0076] (C 6 -C 20 )aryl; (C 6 -C 20 )aryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro; (C 6 -C 20 )heteroaryl; and (C 6 -C 20 )heteroaryl substituted with one or more radicals independently selected from (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro;
[0077] R 2 , and R 2 ′ are monoradicals each one being independently selected from the group consisting of hydrogen, (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro; and
[0078] G is a diradical selected from the group consisting of—S(═O) 2 —, (C 1 -C 6 )alkyl, —S(═O)—, —C(═O)—, —P(═O)(R 4 )—, —P(═O)(NR 6 R 7 )—, and —P(═O)(OR 4 )—, being R 4 , R 6 , and R 7 as defined above.
[0079] In another embodiment of the first aspect of the invention, G is a diradical selected from the group consisting of —P(═S)(R 5 ), —S(═O) 2 —, (C 1 -C 6 )alkyl, —S(═O)—, —C(═O)—, —P(═O)(R 4 )—, —P(═O)(NR 6 R 7 )— and —P(═O)(OR 4 ), being R 4 , R 5 , R 6 and R 7 as defined in the first aspect of the invention.
[0080] In another embodiment of the first aspect of the invention, G is a diradical selected from the group consisting of —S(═O) 2 —, (C 1 -C 6 )alkyl, —S(═O)—, —C(═O)—, —P(═O)(R 4 )—, —P(═O)(NR 6 R 7 )— and —P(═O)(OR 4 )—, being R 4 , R 5 , R 6 and R 7 as defined in the first aspect of the invention.
[0081] In another embodiment of the first aspect of the invention, Y 1 to Y 4 are the same. In another embodiment of the first aspect of the invention, Y 1 to Y 4 are selected from the group consisting of: (C 6 -C 20 )aryl; and (C 6 -C 20 )aryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro. In another embodiment Y 1 to Y 4 are C 6 -C 20 aryl. In another embodiment Y 1 to Y 4 are phenyl.
[0082] In another embodiment of the first aspect of the invention, radicals FG 1 and FG 2 are —OH. In another embodiment of the first aspect of the invention FG 1 and FG 2 are in meta position. In another embodiment, radicals FG 1 and FG 2 are —OH and are in meta position.
[0083] In another embodiment of the first aspect of the invention, Z 1 to Z 4 radicals are diradicals of formula (III) as defined above, wherein A l and A 2 are the same. In another embodiment, Z 1 to Z 4 radicals are diradicals of formula (III) as defined above wherein A l and A 2 are —O— diradicals.
[0084] In another embodiment of the first aspect of the invention, G is —P(═O)(NR 6 R 7 )—, being R 6 and R 7 as defined above.
[0085] In another embodiment of the first aspect of the invention wherein A l and A 2 are the same and represent —O— diradicals, G is —P(═O)(NR 6 R 7 )—, and R 6 and R 7 are as defined above. In another embodiment, R 6 and R 7 are the same. In another embodiment R 6 and R 7 are hydrogen.
[0086] In another embodiment of the first aspect of the invention, G is —S(═O) 2 —. In another embodiment of the first aspect of the invention wherein A l and A 2 are the same and represent —O— diradicals, G is —S(═O) 2 —.
[0087] In another embodiment of the first aspect of the invention G is —P(═O)(R 4 )—, being R 4 as defined above.
[0088] In another embodiment of the first aspect of the invention wherein A l and A 2 are the same and represent —O— diradicals, G is —P(═O)(R 4 )—, being R 4 as defined above.
[0089] In another embodiment of the first aspect of the invention G is —P(═S)(R 5 )—, being R 5 as defined above.
[0090] In another embodiment of the first aspect of the invention wherein A l and A 2 are the same and represent —O— diradicals, G is —P(═S)(R 5 )—, being R 5 as defined above.
[0091] In another embodiment of the first aspect of the invention R 4 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment, R 4 is (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment R 4 is a (C 6 -C 20 )aryl radical. In another embodiment, R 4 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl
[0092] N-sulfide and anthracenyl. In another embodiment R 4 is a phenyl radical.
[0093] In another embodiment of the first aspect of the invention R 5 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment, R 5 is (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment R 5 is a (C 6 -C 20 )aryl radical. In another embodiment, R 5 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment R 5 is a phenyl radical.
[0094] In another embodiment of the compound of the first aspect of the invention, G is a (C 1 -C 20 )alkyl. In another embodiment G is selected from the group consisting of: methylene, ethylene, propylene, and butylene. In another embodiment G is methylene diradical.
[0095] In another embodiment of the compound of the first aspect of the invention, G is —POR 4 —, wherein R 4 is (C 6 -C 20 )aryl radical, or alternatively G is —PSR 5 —, wherein R 5 is (C 6 -C 20 )aryl radical, or alternatively G is a (C 1 -C 20 )alkyl, or alternatively —S(═O) 2 —, or alternatively —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are hydrogen.
[0096] In another embodiment of the compound of the first aspect of the invention, G is —POR 4 —, wherein R 4 is (C 6 -C 20 )aryl radical, or alternatively G is a (C 1 -C 20 )alkyl, or alternatively —S(═O) 2 —, or alternatively —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are hydrogen.
[0097] In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—, —O—P(═S)(Ph)—O—, —O—P(═O)(NH 2 )—, —O—S(═O) 2 —O—, and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—, —O—P(═O)(NH 2 )—, —O—S(═O) 2 —O—, and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—, and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—, —O—P(═S)(Ph)—O— and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are —O—P(═O)(Ph)—O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are —O—P(═S)(Ph)—O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are —O—CH 2 —O—.
[0098] In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O—, —O—P(═O)(NH 2 )—, —O—S(═O) 2 —O—, and —O—CH 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are independently selected from the group consisting of: —O—P(═O)(Ph)—O— and —O—H 2 —O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are —O—P(═O)(Ph)—O—. In another embodiment of the compound of the first aspect of the invention Z 1 to Z 4 are —O—CH 2 —O—.
[0099] In another embodiment of the compound of the first aspect of the invention, R 2 and R 2 ′ are independently selected from the group consisting of H, (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, and halogen. In another embodiment R 2 and R 2 ′ are the same. In another embodiment R 2 and R 2 are H.
[0100] In another embodiment of the compound of the first aspect of the invention R 1 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 3 -C 20 )alkenyl, (C 3 -C 20 )alkynyl, and (C 1 -C 20 )haloalkyl. In one embodiment the alkenyl and alkynyl have the double and triple bond, respectively, at the end of the carbon chain.
[0101] In another embodiment R 1 is (C 1 -C 20 )alkyl. In another embodiment R 1 is selected from the group consisting of: methyl, ethyl, propyl, and butyl. In another embodiment R 1 is methyl. In another embodiment R 1 is dodecanyl. In another embodiment R 1 is dodecenyl.
[0102] In another embodiment the compound of formula (Ia), (Ib), or (Ic) is selected from the group consisting of:
[0000]
[0000] and a stereoisomer thereof; wherein in the compound of formula (Ia6) and (Ib6): X means O or S; and Ar means tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment Ar means mesitylene, naphthalene, and anthracene.
[0103] In another embodiment of the first aspect of the invention the compound is 2 0 selected from the group consisting of:
[0000]
[0000] and a stereoisomer thereof; wherein in the compound of formula (Ia6) and (Ib6): R means a (C 1 -C 6 )alkyl; X means O or S; and Ar means mesitylene, naphthalene, and anthracene.
[0104] In another embodiment of the first aspect of the invention the compound is selected from the group of compounds consisting of: compound of formula (Ia1), compound of formula (Ia2), compound of formula (Ia3), compound of formula (Ib1), compound of formula (Ib2), compound of formula (Ib7), compound of formula (Ib8), compound of formula (Ib9), compound of formula (Ib10), compound of formula (Ib11), compound of formula (Ib12), compound of formula (Ib13), compound of formula (Ic1), compound of formula (Ic3), compound of formula (Ic4), and a stereoisomer thereof.
[0105] In another embodiment of the first aspect of the invention the compound is selected from the group consisting of the compounds of formula: (la1), (Ib1), (Ib7), (Ib8), (Ib9), (Ib10), (Ib11), (Ib12), (Ib13), (Ic3), (Ic4), and a stereoisomer thereof. In still another embodiment the compound is selected from the compound of formula (Ia1), compound of formula (Ib1), compound of formula (Ib7), compound of formula (Ib8), compound of formula (Ib9), compound of formula (Ib13), compound of formula (Ic3), and compound of formula (Ic4).
[0106] In another embodiment of the first aspect of the invention the compound is selected from the group of compounds consisting of: compound of formula (Ia1), compound of formula (Ia2), compound of formula (Ia3), compound of formula (Ib1), compound of formula (Ib2), and compound of formula (Ic1), and a stereoisomer thereof.
[0107] In one embodiment, the compound of the first aspect of the invention is one of formula (Ia). In one embodiment, the compound of formula (Ia) is one wherein Z 1 is a diradical of formula (II) as defined above, wherein A l and A 2 are the same. In another embodiment A l and A 2 are —O— diradicals. In one embodiment of the compound of formula (Ia), G is —S(═O) 2 —. In another embodiment of the compound (Ia), G is —P(═O)(R 4 )— being R 4 as defined above. In another embodiment R 4 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment of the compound (Ia), R 4 is selected from (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment R 4 is a (C 6 -C 20 )aryl radical. In another embodiment of the compound (Ia), R 4 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment of the compound (Ia), R 4 is a phenyl radical. Alternatively, the compound of formula (Ia) is one wherein G is a (C 1 -C 20 )alkyl. In another embodiment of the compound (Ia), G is selected from the group consisting of: methylene, ethylene, propylene, and butylene. In another embodiment of the compound (Ia), G is a methylene diradical. Alternatively, in another embodiment of the compound of formula (Ia), G is —P(═O)(NR 6 R 7 )—, and R 6 and R 7 are as defined above. In another embodiment of the compound of formula (Ia), R 6 and R 7 are the same. In another embodiment of the compound of formula (Ia) R 6 and R 7 are hydrogen. In another embodiment of the compound of formula (Ia) Z 1 is selected from the group consisting of: —O—P(═O)(Ph)—O—, —O—P(═O)(NH 2 )—O—, —O—S(═O) 2 —O—, and —O—CH 2 —O—. In another embodiment of the compound of formula (Ia) Y 1 to Y 4 are the same and are selected from the group consisting of: (C 6 -C 20 )aryl; and (C 6 -C 20 )aryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro. In another embodiment Y 1 to Y 4 are (C 6 -C 20 )aryl. In another embodiment of the compound (Ia), Y 1 to Y 4 are phenyl. In another embodiment of the compound (Ia), radicals FG 1 and FG 2 are —OH. In another embodiment of the compound of formula (Ia) FG 1 and FG 2 are in meta position. In another embodiment of the compound of formula (Ia) radicals FG 1 and FG 2 are —OH and are in meta position. In another embodiment of the compound of formula (Ia) R 2 and R 2 ′ are hydrogen. In another embodiment of the compound of formula (Ia) R 1 is (C 1 -C 20 )alkyl. In another embodiment of the compound of formula (Ia) R 1 is selected from methyl, ethyl, propyl, isopropyl, and tert-butyl. In another embodiment of the compound of formula (Ia) R 1 is methyl. In another embodiment, A l and A 2 are —O—diradicals; G is —P(═O)(R 4 )— or (C 1 -C 6 )alkyl; R 4 is a (C 6 -C 20 )aryl radical; Y 1 to Y 4 are the same and are (C 6 -C 20 )aryl; FG 1 and FG 2 are —OH and are in meta position; R 2 and R 2 ′ are hydrogen; and R 1 is (C 1 -C 20 )alkyl. In another embodiment, A l and A 2 are —O—diradicals; G is —P(═O)(R 4 )— or (C 1 -C 6 )alkyl; R 4 is a (C 6 -C 20 )aryl radical; Y 1 to Y 4 are the same and are phenyl; FG 1 and FG 2 are —OH and are in meta position; R 2 and R 2 ′ are hydrogen; and R 1 is (C 1 -C 20 )alkyl. In another embodiment, the compound of formula (Ia) is selected from the compounds of formula (Ia1), (Ia2), (Ia3), (Ia4), and (Ia5) and a stereoisomer thereof. In another embodiment, the compound of formula (Ia) is selected from the compounds of formula (Ia1), (Ia2), (Ia3), and a stereoisomer thereof.
[0108] In another embodiment, the compound of the first aspect of the invention is one of formula (Ib). In one embodiment of the compound of formula (Ib), Z 1 and Z 3 are diradicals independently selected from the group consisting of: —O—P(═O)(R 4 )—O—, —N(R 3 )—P(═O)(R 4 )—N(R 3 )—, —N(R 3 )—P(═O)(R 4 )—O—, —O—P(═S)(R 5 )O—, —N(R 3 )—P(═S)(R 5 )N(R 3 )—, —N(R 3 )—P(═S)(R 5 )—O—, —N(R 3 )—S(═O) 2 —N(R 3 )—, —N(R 3 )—S(═O) 2 —O—, —O—S(═O) 2 —O—, —O—(C 1 -C 6 )alkyl-O—, —O—(C 1 -C 6 )alkyl-N(R 3 )—, —N(R 3 )-(C 1 -C 6 )alkyl-N(R 3 )—, and —P(═O)(NR 6 R 7 )—, wherein R 5 is a radical selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl, and R 3 , and R 4 are as defined above, and R 6 and R 7 are as defined above. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are independently selected from —O—P(═S)(R 5 )O—, —O—P(═O)(R 4 )—O—, —O—(C 1 -C 6 )alkyl-O—, and —P(═O)(NR 6 R 7 )—. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are independently selected from —O—P(═O)(R 4 )—O—, —O—(C 1 -C 6 )alkyl-O—, and —P(═O)(NR 6 R 7 )—. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are the same. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are the same and are selected from —O—P(═S)(R 5 )O—, —O—P(═O)(R 4 )O— and —O—(C 1 -C 6 )alkyl-O—, wherein R 4 and R 5 are as defined above. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are the same and are selected from —O—P(═O)(R 4 )O— and —O—(C 1 -C 6 )alkyl-O—, wherein R 4 is as defined above. In another embodiment R 4 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment of the compound (Ib), R 4 is selected from (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment R 4 is a (C 6 -C 20 )aryl radical. In another embodiment of the compound (Ib), R 4 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment of the compound (Ib), R 4 is a phenyl radical. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are —O—P(═O)(Ph)—O—. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are —O—CH 2 —O—. In another embodiment of the compound of formula (Ib), Z 1 and Z 3 are —O—P(═S)(Ph)—O—. In another embodiment of the compound of formula (Ib) Z 1 and Z 3 are different. In another embodiment of the compound of formula (Ib) one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O— or —O—(C 1 -C 6 )alkyl-O—, and the other Z diradical is selected from the group consisting of: —N(R 3 )—P(═O)(R 4 )—N(R 3 )—, —N(R 3 )—P(═O)(R 4 )—O—, —O—P(═S)(R 5 )—O—, —N(R 3 )—P(═S)(R 5 )—N(R 3 )—, —N(R 3 )—P(═S)(R 5 )—O—, —N(R 3 )—S(═O) 2 —N(R 3 )—, —N(R 3 )—S(═O) 2 —O—, —O—S(═O) 2 —O—, —O—(C 1 -C 6 )alkyl-O—, —O—(C 1 -C 6 )alkyl-N(R 3 )—,—N(R 3 )—(C 1 -C 6 )alkyl-N(R 3 )—, and —P(═O)(NR 6 R 7 )—, being R 3 , R 4 , R 5 , R 6 and R 7 as defined above. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O— and the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, being R 4 as defined above. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, and R 4 is selected from the group consisting of: (C 1 -C 20 )alkyl, (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment of the compound (Ib), R 4 is selected from (C 6 -C 20 )aryl, and (C 6 -C 20 )aryl substituted as defined above. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, and R 4 is a (C 6 -C 20 )aryl radical. In another embodiment of the compound (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, and R 4 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment of the compound (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, being R 4 are a phenyl radical, and the other Z diradical is —O—(C 1 -C 6 )alkyl-O—. In another embodiment of the compound (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, being R 4 a radical selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl; and the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, being the alkyl radical selected from methylene, ethylene, propylene, and butylene. In another embodiment of the compound (Ib), one of Z 1 and Z 3 is —O—P(═O)(Ph)—O—; and the other Z diradical is —O—(C 1 -C 6 )alkyl-O—, being the alkyl radical selected from methylene, ethylene, propylene, and butylene. In another embodiment of the compound (Ib), one of Z 1 and Z 3 is —O—P(═O)(R 4 )—O—, being R 4 a radical selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl; and the other Z diradical is —O—CH 2 —O—. In another embodiment of the compound of formula (Ib) one of Z 1 and Z 3 is —O—P(═O)(Ph)—O—and the other Z diradical is —O—CH 2 —O—. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—(C 1 -C 6 )alkyl-O—and the other is —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are as defined above. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—CH 2 —O—and the other is —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are as defined above. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—CH 2 —O— and the other is —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are the same. In another embodiment of the compound of formula (Ib), one of Z 1 and Z 3 is —O—CH 2 —O— and the other is —P(═O)(NR 6 R 7 )—, wherein R 6 and R 7 are the same and are hydrogen. In another embodiment of the compound of formula (Ib), Y 1 to Y 4 are the same and are selected from the group consisting of: (C 6 -C 20 )aryl; and (C 6 -C 20 )aryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro. In another embodiment of the compound of formula (Ib), Y 1 to Y 4 are (C 6 -C 20 )aryl. In another embodiment of the compound of formula (Ib), Y 1 to Y 4 are phenyl. In another embodiment of the compound of formula (Ib), R 2 and R 2 ′ are hydrogen. In another embodiment of the compound of formula (Ib), R 1 is selected from methyl, ethyl, propyl, and butyl. In another embodiment of the compound of formula (Ib), R 1 is methyl. In another embodiment, A l and A 2 are —O—diradicals; G is —P(═O)(R 4 )—, or (C 1 -C 6 )alkyl; R 4 is a (O 6 -C 20 )aryl radical; Y 1 to Y 4 are the same and are (C 6 -C 20 )aryl; FG 1 and FG 2 are —OH and are in meta position; R 2 and R 2 ′ are hydrogen; and R 1 is (C 1 -C 20 )alkyl. In another embodiment, the compound of formula (Ib) is selected from the compounds of formula (Ib1), (Ib2), (Ib3), (Ib4), (Ib5), (Ib10) and a stereoisomer thereof. In another embodiment, the compound of formula (Ib) is selected from the compounds of formula (Ib1), (Ib7), (Ib8), (Ib9), (Ib10), (Ib11), (Ib12), (Ib13) and a stereoisomer thereof. In another embodiment, the compound of formula (Ib) is selected from the compounds of formula (Ib1), (Ib7), (Ib8), (Ib9), (Ib10) and a stereoisomer thereof. In another embodiment, the compound of formula (Ib) is selected from the compounds of formula (Ib1), (Ib2), (Ib3), (Ib4), (Ib5), (Ib6), (Ib7), (Ib8), (Ib9), (Ib10) and a stereoisomer thereof. In another embodiment of the compound of formula (Ib), R 1 is methyl. In another embodiment, A l and A 2 are —O— diradicals; G is —P(═S)(R 5 )—; R 5 is a (C 6 -C 20 )aryl radical; Y 1 to Y 4 are the same and are (C 6 -C 20 )aryl; FG 1 and FG 2 are —OH and are in meta position; R 2 and R 2 ′ are hydrogen; and R 1 is (C 1 -C 20 )alkyl. In another embodiment, the compound of formula (Ib) is one selected from the compounds of formula (Ib11), (Ib12), (Ib13), and a stereoisomer thereof.
[0109] In another embodiment, the compound of formula (Ib) is selected from a compound of formula (Ib1), (Ib2), (Ib7), (Ib8), (Ib9), (Ib10), (Ib11), (Ib12), (Ib13), and a stereoisomer thereof.
[0110] In another embodiment, the compound is one of formula (Ic). In another embodiment of the compound of formula (Ic) Z 1 to Z 4 are diradicals independently selected from the group consisting of: —O—P(═O)(R 4 )—O—, —N(R 3 )—P(═O)(R 4 )—N(R 3 )—, —N(R 3 )—P(═O)(R 4 )—O—, —O—P(═S)(R 5 )—O—, —N(R 3 )—P(═S)(R 5 )—N(R 3 )—, —N(R 3 )—P(═S)(R 5 )—O—, —N(R 3 )—S(═O) 2 —N(R 3 )—, —N(R 3 )—S(═O) 2 —O—, —O—S(═O) 2 —O—, —O—(C 1 -C 6 )alkyl-O—, —O—(C 1 -C 6 )alkyl-N(R 3 )—, —N(R 3 )—(C 1 -C 6 )alkyl-N(R 3 ), wherein R 5 is a radical selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl, wherein R 3 , and R 4 are as defined above. In another embodiment of the compound of formula (Ic), Z 1 to Z 4 are the same. In another embodiment of the compound of formula (Ic), Z 1 to Z 4 are —O—P(═O)(R 4 )—O—, being R 4 as defined above. In another embodiment of the compound of formula (Ic), Z 1 to Z 4 are —O—P(═O)(R 4 )—O—, being R 4 a (C 6 -C 20 ) aryl radical. In another embodiment of the compound of formula (Ic), Z 1 to Z 4 are —O—P(═O)(R 4 )—O—, being R 4 a phenyl radical. In another embodiment of the compound of formula (Ic), at least one of Z 1 to Z 4 is different from the others. In another embodiment of the compound of formula (Ic), Z 2 , Z 3 , and Z 4 are the same. In another embodiment of the compound of formula (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, wherein R 4 is as defined above, and the other three Z diradicals are the same and are selected from the group consisting of: —N(R 3 )—P(═O)(R 4 )—N(R 3 )—, —N(R 3 )—P(═O)(R 4 )—O—, —O—P(═S)(R 5 )—O—, —N(R 3 )—P(═S)(R 5 )—N(R 3 )—, —N(R 3 )—P(═S)(R 5 )—O—, —N(R 3 )—S(═O) 2 —N(R 3 )—, —N(R 3 )—S(═O) 2 —O—, —O—S(═O) 2 —O—, —O—(C 1 -C 6 )alkyl-O—, —O—(C 1 -C 6 )alkyl-N(R 3 )—, —N(R 3 )—(C 1 -C 6 )alkyl-N(R 3 )—, wherein R 3 , R 4 , and R 5 are as defined above. In another embodiment of the compound of formula (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, and the other three Z diradicals are —O—(C 1 -C 6 )alkyl-O—. In another embodiment of the compound of formula (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, being R 4 (C 6 -C 20 )aryl or (C 6 -C 20 )aryl substituted as defined above, and the other three Z diradicals are —O—(C 1 -C 6 )alkyl-O—. In another embodiment of the compound of formula (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, the other Z diradicals are —O—(C 1 -C 6 )alkyl-O—, and R 4 is a (C 6 -C 20 )aryl radical. In another embodiment of the compound (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, the other Z diradicals are —O—(C 1 -C 6 )alkyl-O—, and R 4 is selected from the group consisting of: phenyl, tolyl, mesitylenyl, naphthyl, bipheynylyl, quinolinyl N-oxide, quinolinyl N-sulfide and anthracenyl. In another embodiment of the compound (Ic), one of Z 1 to Z 4 is —O—P(═O)(R 4 )—O—, the other Z diradicals are —O—(C 1 -C 6 )alkyl-O—, and R 4 is a phenyl radical. In another embodiment of the compound of formula (Ic), one of Z 1 to Z 4 is —O—P(═O)(Ph)—O—and the other three Z diradicals are —O—CH 2 —O—. In another embodiment of the compound of formula (Ic), Y 1 to Y 4 are the same. In another embodiment of the compound of formula (Ic) Y 1 to Y 4 are the same and are selected from the group consisting of: (C 6 -C 20 )aryl; and (C 6 -C 20 )aryl substituted with one or more radicals independently selected from the group consisting of: (C 1 -C 20 )alkyl, (C 1 -C 6 )alkyl-O—, (C 1 -C 6 )haloalkyl, halogen, cyano, and nitro. In another embodiment of the compound of formula (Ic), Y 1 to Y 4 are (C 6 -C 20 )aryl radicals as defined above. In another embodiment of the compound of formula (Ic), Y 1 to Y 4 are phenyl radicals. In another embodiment of the compound of formula (IC), R 2 and R 2 ′ are hydrogen. In another embodiment of the compound of formula (Ic), R 1 is (C 1 -C 20 )alkyl. In another embodiment of the compound of formula (Ic), R 1 is selected from methyl, ethyl, propyl, dodecanyl, and isobutyl. In another embodiment of the compound of formula (Ic), R 1 is methyl. In another embodiment of the compound of formula (Ic), R 1 is dodecanyl. In another embodiment of the compound of formula (Ic), R 1 is (C 3 -C 20 )alkenyl. In another embodiment of the compound of formula (Ic), R 1 is dodecenyl. In another embodiment, the compound of formula (Ic) is selected from (Ic1), (Ic2), (Ic3), (Ic4), and a stereoisomer thereof. In still yet another embodiment, the compound of formula (Ic) corresponds to the compound of formula (Ic1), (Ic3), (Ic4) or a stereoisomer thereof. In another embodiment, the compound of formula (Ic) is selected from (Ic1), and (Ic2). In another embodiment, the compound of formula (Ic) is selected from (Ic3), and (Ic4).
[0111] In another aspect, the present invention provides a process for the preparation of the compound of the present invention, as defined above.
[0112] In one embodiment, when the compound is one of formula (Ia), the process of the present invention comprises the reaction between a compound of formula (VIIA):
[0000]
[0000] and a compound of formula (VIII) as defined above.
[0113] In another embodiment, when the compound is one of formula (Ia), the process comprises the reaction between the compound of formula (VII) and a compound of formula (VIII), wherein G is selected from —P(═O)NR 6 R 7 —, —P(═O)(R 4 )—, —S(═O) 2 —, and —(C 1 -C 6 )alkyl-, B 1 and B 2 are halogen, and R 4 is as defined in any of the previous embodiments. In another embodiment, when the compound is one of formula (Ia1) or (Ia3), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is (C 6 -C 20 )aryl. In another embodiment, when the compound is one of formula (Ia1) or (Ia3), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is phenyl. In another embodiment, when the compound is one of formula (Ia2), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is methyl, and B 1 and B 2 are halogen. In another embodiment, the compound of formula (VIII) is selected from phenylphosphonic dichloride and bromochloromethane.
[0114] In another embodiment, when the compound is one of formula (Ib), the process of the present invention comprises the reaction between a compound of formula (VIIA) and a compound of formula (VIII), as defined above. In another embodiment, when the compound is one of formula (Ib), the process comprises the reaction between the compound of formula (VII) and a compound of formula (VIII), wherein G is selected from —P(═S)(R 5 )—, —P(═O)(R 4 )— and —(C 1 -C 6 )alkyl-, B 1 and B 2 are halogen, and R 4 and R 5 are as defined in any of the previous embodiments. In another embodiment, when the compound is one of formula (Ib1) or (Ib2), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is selected from —P(═O)(R 4 )— and —(C 1 -C 6 )alkyl-, B 1 and B 2 are halogen, and R 4 is as defined in any of the previous embodiments. In another embodiment, when the compound is one of formula (Ib1) or (Ib2), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is (O 6 -C 20 )aryl. In another embodiment, when the compound is one of formula (Ib1) or (Ib2), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is phenyl. In another embodiment, when the compound is one of formula (Ib1) or (Ib2), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is methyl, and B 1 and B 2 are halogen. In another embodiment, the compound of formula (VIII) is selected from phenylphosphonic dichloride and bromochloromethane.
[0115] In another embodiment, when the compound is one of formula (Ib7), (Ib8) or (Ib9), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is selected from —P(═O)(R 4 )— and —(C 1 -C 6 )alkyl-, B 1 and B 2 are halogen, and R 4 is as defined in any of the previous embodiments. In another embodiment, when the compound is one of formula (Ib7), (Ib8) or (Ib9), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is (O 6 -C 20 )aryl.
[0116] In another embodiment, when the compound is one of formula (Ib7), (Ib8) or (Ib9), the process comprises the reaction between the compound of formula (VIIA) and a compound of formula (VIII), wherein G is —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is phenyl. In another embodiment, the compound of formula (VIII) is phenylphosphonic dichloride.
[0117] In another embodiment, the compound of formula (Ib11), (Ib12) or (Ib13) can be obtained by a process comprising:
[0118] (i) the reaction between a compound of formula (VIIA) with phenylphosphine dichloride; and
[0119] (ii) mixing the product of step (i) with sulphur (S 2 ).
[0120] In another embodiment, the compound of formula (Ib1) or (Ib2) can be obtained by a process comprising the reaction between a compound of formula (Ia1) or (Ia3) as defined above, and a compound of formula (VIII) wherein G is —(C 1 -C 6 )alkyl-, and B 1 and B 2 are halogen.
[0121] In another embodiment, the compound (Ib6) can be obtained reacting the compound of formula (Ia6) as defined above with a compound of formula (IX):
[0000] Cl—P(X)Ar—Cl (IX)
[0122] wherein X means O or S; and Ar means tolyl, mesitylenyl, naphthyl, quinolinyl N-oxide, quinolynyl N-sulfide, bipheynylyl, and anthracenyl.
[0123] In another embodiment, when the compound is one of formula (Ic1), (Ic3) or (Ic4), the process of the present invention comprises the reaction between a compound of formula (VIIb) wherein R 1 is methyl or dodecanyl:
[0000]
[0124] with a compound of formula (VIII) as defined above. In another embodiment, when the compound is one of formula (Ic1), the process comprises the reaction between the compound of formula (VIIb) and a compound of formula (VIII), wherein G is—P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is as defined in any of the previous embodiments. In another embodiment, when the compound is one of formula (Ic1), (Ic3) or (Ic4), the process comprises the reaction between the compound of formula (VIIb) wherein R 1 is methyl or dodecanyl and a compound of formula (VIII), wherein G is selected from —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is (C 6 -C 20 )aryl. In another embodiment, when the compound is one of formula (Ic1), (Ic3) or (Ic4), the process comprises the reaction between the compound of formula (VIIb) wherein R 1 is methyl or dodecanyl and a compound of formula (VIII), wherein G is selected from —P(═O)(R 4 )—, B 1 and B 2 are halogen, and R 4 is phenyl.
[0125] In the process for preparing the compounds of formula (Ia), (Ib), or (Ic) the basic medium is selected from the group consisting of a tertiary amine—NR 9 R 10 R 11 , being R 9 , R 10 , and R 11 radicals independently selected and representing (C 1 -C 6 )alkyl; pyridine; alkaline carbonate; and alkaline (C 1 -C 6 )alkyl-O—. Preferably, the basic medium is a tertiary amine or an alkaline carbonate. In an embodiment, the basic medium is selected from the group consisting of triethylamine and diisopropylethylamine. In another embodiment, the basic medium is potassium carbonate. The molar ratio between the basic medium required in the preparation of a compound of formula (Ia), (Ib), or (Ic) and the compound of formula (VIII) is comprised from 2:1 to 15:1.
[0126] The term “molar ratio” between two products refers to the relation of moles of one product vs. the moles of the other product. In the case of the molar ratio between the basic medium and the compound of formula (VIII), this means the relation of moles of basic medium vs. the moles of the compound of formula (VIII).
[0127] The term “weight ratio” between two products refers to the relation of weight of one product vs. the weight of the other product, both weights being expressed in the same units. In the case of the weight ratio between the plasticizer and the compound of the invention, this means the relation of weight of plasticizer vs the weight of compound of the invention, both expressed in mg.
[0128] In another aspect, the present invention provides a membrane comprising a compound selected from the compounds of formula (Ia), (Ib), (Ic), (IV), (V) and a stereoisomer thereof, or alternatively the compound is one of formula (VI), together with a plasticizer, a cation-exchanger salt, and a polymeric matrix.
[0129] The polymeric matrix comprises a polymer or mixture of polymers of high molecular average weight, typically comprised from 70000 to 250000. With such a molecular weight it is guaranteed the inert character of the polymer, independently of its chemical composition. In one embodiment, the polymer(s) composing the polymeric matrix has a molecular average weight comprised from 70000 to 250000. In another embodiment the polymer(s) has a molecular average weight comprised from 100000 to 200000. The polymer or mixture of polymers is able of forming thin films. Illustrative non-limitative examples of polymers are polyvinyl chloride (also carboxylated), poly(vinylidene chloride), polyvinyl chloride/polyvinyl alcohol, Urushi (Japanese lacquer) acrylate, polysiloxane, siloxane sol-gel and monolayer, poly(acrylonitrile), polyurethanes (particularly aromatic), poly(vinyl butyral), poly(vinyl formal), poly(vinyl acetate), silicone elastomers, cellulose esters and polycarbonates.
[0130] In one embodiment the polymeric matrix comprises a mixture of polymers of the same or different chemical nature. The skilled person, making use of the general knowledge, can routinely choose, among those available in the state of the art, the appropriate polymer(s) in the appropriate amount(s) depending on the compound selected as ionophore.
[0131] The term “same chemical nature”, when comparing two or more polymers forming the polymeric matrix, has to be understood as polymers with the same functional groups in their backbones but differing in the molecular average weight. An illustrative non-limitative example of a mixture of polymers of the “same nature” would be a mixture of polyurethanes, wherein the common functional group to all polyurethanes is the urethane group.
[0132] The term “different chemical nature”, when comparing two or more polymers forming the polymeric matrix, has to be understood as polymers with the different functional groups in their backbones. An illustrative non-limitative example of a mixture of polymers of “different chemical nature” would be a mixture of polyurethane (wherein the functional group is an urethane) and PVC (wherein the functional group is the vinyl chloride).
[0133] Advantageously, such a polymer, in combination with the plasticizer, facilitates ionic mobility across the membrane interface.
[0134] The person skilled in the art is able, making use of the general knowledge, of selecting those more appropriate polymers and adjusting the amounts, depending on the ionophore to be manufactured in the form of an ion-selective membrane (Bakker E. et al., 1997). In one embodiment, the % by weight of polymeric matrix is comprised from 20 to 40%. In another embodiment, the % by weight of polymeric matrix is comprised from 25 to 35%. In another embodiment, the % by weight of polymeric matrix is comprised from 28 to 32%.
[0135] The term “percentage (%) by weight” refers to the percentage of each component of the membrane in relation to the total weight of the membrane composition.
[0136] In one embodiment, the polymer is poly(vinyl chloride) (PVC). In another embodiment the PVC used has a molecular weight comprised from 70000 to 250000. In another embodiment the polymer is PVC having a molecular weight comprised from 100000 to 200000. In another embodiment, the PVC is in a % by weight comprised from 20 to 40%. In another embodiment, the % by weight of PVC is comprised from 25 to 35%. In another embodiment, the % by weight of PVC is comprised from 28 to 32%.
[0137] The term “plasticizer” has to be understood in the present invention as any of the available plasticizers for the manufacturing of ion-selective membranes.
[0138] Typical plasticizers are for example (but not restricted to) 2-nitrophenyl octyl ether (o-NPOE), bis(2-ethylhexyl) sebacate (DOS) and chloroparaffin, as well as other chemical structures such as phthalates, adipates suberates, azelates, glutarates, succinates and hexahydrophtalates. Other non-polymeric discrete organic compounds having low molecular weight (usually of 500 to 20.000 molecular weight) and a boiling temperatures comprised from 150 to 500° C., can also be used as plasticizers. The function of the plasticizers is to make the membrane softer and much more resistant to mechanical stress such as poking, bending or stretching, as well as reducing the glass transition temperature and increasing the polarity of the membrane.
[0139] Plasticizers also enhance the flexibility by facilitating the movement of the polymer macromolecules and thus influence the partitioning of ions. The plasticizer must be miscible with the polymeric matrix in the membrane in order to obtain a homogeneous dispersion. Typical mixtures of plasticizer with the polymeric matrix are in a weight ratio comprised from 1:1 to 4:1 (plasticizer:polymer). The plasticizer is present in the membrane in the amount sufficient to solvate the creatinine receptor, anywhere in a weight ratio vs the amount of ionophore comprised 10:1 to 100:1. In one embodiment the weight ratio between the plasticizer and the ionophore is comprised from 10:1 to 30:1. In one embodiment the weight ratio between the plasticizer and the ionophore is comprised from 15:1 to 25:1.In another embodiment, the plasticizer is in a % by weight comprised from 40 to 80%. In another embodiment, the plasticizer is in a % by weight comprised from 55 to 65%. In one embodiment, the plasticizer is 2-nitrophenyl octyl ether. In another embodiment, the weight ratio plasticizer:polymeric matrix is comprised from 1:1 to 4:1. In another embodiment, the weight ratio plasticizer:polymeric matrix is comprised from 2:1 to 3:1. In another embodiment the plasticizer is 2-nitrophenyl octyl ether, and the weight ratio between the 2-nitrophenyl octyl ether and the polymeric matrix is comprised from 2:1 to 3:1. In another embodiment the plasticizer is 2-nitrophenyl octyl ether, it is in % by weight comprised from 55 to 65%, and the weight ratio between the 2-nitrophenyl octyl ether and the polymeric matrix is comprised from 2:1 to 3:1.
[0140] The membrane of the sensor also includes a cation-exchanger salt which is also soluble in the polymeric matrix. This salt is typically composed, on one hand, by a large organic molecule which is an anion (negatively charged). On the other hand, the counterion is a small cation, such as alkali metals, among many other possibilities. The role of this salt is to facilitate the entrapment of the target analyte from the ionophore in case it is a neutral macromolecule. The inclusion of this lipophilic ionic salt helps to maintain the permselectivity of the membrane where each cation is complemented by a lipophilic anion from the ion-exchanger. The cation exchanger avoids coextraction of ions with different charges from the sample into the membrane phase in order to accomplish the theoretical Nernstian behavior from an ion-selective electrode. The presence of cation exchanger is required to obtain a membrane that exchanges ions with the same charge sign (called permselectivity or Donnan exclusion). Illustrative non-limitative examples of cation-exchanger salts useful in the manufacture of ion-selective membranes are: sodium tetrakis-[3,5-bis(1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl)-phenyl]borate trihydrate (NaHFPB) and potassium tetrakis[3,5-(trifluoromethyl)phenyl]borate (KTFPB).
[0141] In one embodiment, the molar ratio of the compound of formula (Ia), (Ib), (Ic), (IV), (V), or a stereoisomer thereof, or alternatively of a compound of formula (VI) and the ion-exchanger salt is comprised from 10:1 to 10:4. This range of molar ratio guarantees the selectivity of the ionophore for its specific analyte (creatinine) to other species present in real samples. The final molar ratio will depend on the particular ion-exchanger salt and ionophore. As it is illustrated below, when the cation-exchanger salt is KTFPB and the ionophore is the compound (Ib1), the optimal molar ratio was about 10:3. It was found that with such a ratio the best results for the sensor were obtained, leading to complement the creatinine positive charge in the ion-selective membrane by first excluding the K + from the cation-exchanger salt in the membrane with creatinine from the sample.
[0142] In another embodiment, the amount in % by weight of ion-exchanger salt is comprised from 0.1 to 2%. In another embodiment, the amount is about 1%.
[0143] The creatinine-selective membrane of the invention is prepared by dissolving all components in a suitable organic solvent, such as tetrahydrofuran. This solution containing all the membrane components dissolved can be referred hereinafter as “membrane cocktail” and it is used to form the membrane by suitable evaporation of the solvent.
[0144] The membrane composition may also include chemical substances, nanomaterials or any type of compound that act as “ion-to-electron” transducer, facilitating the generation and stability of the potentiometric signal, as described in the literature. The need to incorporate these substances, and the way to do it, will be evident for any person with knowledge in the field (Tanji yin and Wei qin, 2013).
[0145] As the skilled person will recognize, when preparing a membrane composition of the invention, the different components will be in such amounts that they sum up 100% by weight.
[0146] The membrane described here can be used to build electrodes with different configurations. Electrodes for the determination of the content of a liquid sample have been described by others. They commonly contain a plastic membrane which has an ion-selective component (ionophore) and a solvent/plasticizer compound in which the ion-selective component can be dissolved. In addition to glasses selectively permeable to ions, hydrogen ionophores such as lipophilic derivatives of uncouplers of oxidative phosphorylation and lipophilic tertiary amines have been used.
[0147] The two most common arrangements are solid-contact ISE and the inner solution ISE. There are different ways to build these ISE. Some typical examples are given below.
[0148] a) Solid-contact ion-selective electrode (solid contact ISE)
[0149] Transducer Layer
[0150] A transducer element is required in order to avoid the formation of capacitive layers that affect the stability of the potentiometric readings. Illustrative non-limitative examples of these transducing components are electroactive conjugated polymers (conducting polymers), as well as a variety of nanomaterials, such as three-dimensionally ordered mesoporous (3DOM) carbon and different types of carbon nanotubes (CNTs).
[0151] Ion-Selective Membrane
[0152] A solid contact potentiometric sensor is obtained by casting a suitable volume of the polymeric membrane cocktail onto a conductive substrate which can be a transducer layer previously deposited, or alternatively, incorporated into the membrane cocktail. Next, the solvent is evaporated, in order to form a suitable membrane. Alternatively, the solid transducer element can be incorporated with the ion-selective membrane cocktail. Other methods of membrane deposition include dip coating, where the substrate with the transducing layer is submerged into the ion-selective membrane cocktail; spin coating, where the conductor is spun and immersed into the ion-selective membrane cocktail and removed to let it dry.
[0153] Once the membrane is fully dried onto the conductor, the electrode is submerged into a conditioning solution until stable readings of potential are obtained.
[0154] b) Inner-solution ion-selective electrode (inner solution ISE)
[0155] In the case of ion-selective electrode with inner filling solution, the polymeric membrane is cast onto a glass-casting plate. Once dried, the membrane is gently peeled off and placed in the membrane packing piece of the electrode and finally pressed with the membrane housing to put the membrane in contact with the inner electrolyte solution, which is 10 mM of creatinine in 10 mM buffer solution, the buffer solution providing a pH which is below the creatinine pKa value. Finally, the polymeric membrane is placed in contact with a conditioning solution until stable potential readings are obtained.
[0156] The buffer for conditioning can be any able to control the pH at values in the range from approximately 3 to approximately 4.5. Buffer solutions can be (but are not restricted to) acetic acid/acetate, phosphate/citrate, etc., adjusted to the suitable pH value.
[0157] The conditioning of the creatinine membrane once completely dried consists of immersing the membrane in a buffer solution for such a period of time that allows obtaining stable potential readings along with a creatinine concentration equal or higher than 1 mM. As the skilled in the art will recognize, when working at lower concentrations the time required to condition the electrode will be higher than the one required using higher concentrations.
[0158] The calibration of the electrode is carried out with a buffer solution whose concentration is equal or higher than 10 mM with increasing concentration of creatinine by adding known amounts of creatinine standards. The maximum concentration raised could be about 0.1 M.
[0159] In another aspect the present invention provides a device comprising the electrode of the invention.
[0160] In one embodiment, the device (or potentiometric cell) consists of two electrodes: a reference electrode that keeps a stable and constant potential during the measurements, and the working electrode, in this case the ion-selective electrode, which in this case includes the creatinine selective membrane. The reference electrode can be any type of commercial or home-made system, such as (but not restricted to) silver-silver chloride electrode (in its multiple forms), calomel electrode, etc., that keeps a stable and constant potential during the measurements. In one embodiment, the reference electrode is a silver-silver chloride electrode. The working electrode can be either the inner solution ISE or the solid contact ISE, or any other configurations containing the polymeric membrane described above. In one embodiment, the reference electrode is a double junction Ag/AgCl/KCl 3 M reference electrode containing 1 M LiAcO as electrolyte bridge, type 6.0729.100 (Metrohm AG, Switzerland).
[0161] The measuring circuit is assembled in order to be able to properly record the electromotive force generated between these electrodes by a voltmeter. Other measurement arrangements using other electrochemical approaches, such as for example chronopotentiometry, pulsetrodes, cyclic voltammetry, etc. or any other techniques using these membranes are also possible. This membrane can also be used for building alternative potentiometric methods, such as those using field effect transistors (ISFET)
[0162] There are other potentiometric platforms which can be implemented with this creatinine membrane. A few examples of wearable and disposable sensors to detect creatinine have already been reported, although none of them offered reliable results. One of these possible platforms is onto screen-printed electrodes (SPE) or inkjet-printed electrodes (IPE), which provides a way to reduce the size of the potentiometric cell as well as a way to make them disposable. SPE and IPE have been widely used as potentiometric sensors. Other examples recently introduced that reduce massively the cost of this sensor are (but not restricted to) textiles, papers, rubbers, bandages, carbon fibers, and are possible, as far as the working sensing part of these devices is made by depositing the creatinine membrane by dip-coating, drop-casting, drip-coating, spin-coating, or any other suitable approach to cast a membrane. Embedded sensors, such as those recently described using temporary epidermal printing (tattoos), are also possible.
[0163] In another aspect, the present invention provides a process for quantifying the creatinine in a test sample.
[0164] The test sample can be any bodily test sample, such as blood, urine, and serum, among others.
[0165] The correlation step between the potential value measured and the concentration of creatinine can be performed generating previously a calibration curve. It is well-known for the skilled person in the art how to obtain such a pattern curves. Briefly, solutions of known creatinine concentration are prepared and the potential reading is performed with the electrode of the invention for each one of the solutions. With those readings, it is possible to generate a curve with the correlation between the concentration of creatinine and potential value. From that, measuring the potential in a test sample, this potential reading is applied in the calibration curve and a creatinine concentration value is obtained. The statistical treatment of the data can be performed using different well-known approaches.
[0166] Throughout the description and claims the word “comprise” and variations of the word, are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word “comprise” encompasses the case of “consisting of”. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples are provided by way of illustration, and they are not intended to be limiting of the present invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein.
EXAMPLES
[0167] Unless otherwise stated, all the reagents were obtained from Sigma-Aldrich and were used without further purification unless otherwise stated. All solvents were commercially obtained and used without further purification with the exception of THF which was dried and deoxygenated using an
[0168] MBraun SPS-800 solvent purification system. Routine 1 H NMR spectra were recorded on a Bruker Avance 300 (300 MHz for 1 H NMR), Bruker Avance 400 (400 MHz for 1 H NMR) or a Bruker Avance 500 (500 MHz for 1 H NMR) ultrashield spectrometer. The deuterated solvents (Aldrich) used are indicated in the experimental part; chemical shifts are given in ppm. For CDCl 3 the peaks were referenced relative to the solvent residual peak δH=7.26. For D6-acetone the peaks were referenced relative to the solvent residual peak δH=2.05 ppm. For D4-methanol the peaks were referenced relative to the solvent residual peak δH=3.31 ppm. All NMR J values are given in Hz and are uncorrected. Flash column chromatography was performed with Silica gel Schar1ab60.
Example 1
Synthesis of Starting Tetrahydroxy Calixpyrrole (VIIA)
[0169]
[0170] Concentrated HCl(aq) (36% by weight, 25.3 mL, 0.3 mol, 10 equiv.) followed by pyrrole (2.2 mL, 31 mmol, 1.05 equiv.) were added to a solution of 1-(3-hydroxyphenyl)ethanone (4.04 g, 1 equiv.) in ethylacetate (300 mL, 0.1 M) under air. The resultant mixture was stirred for 14 hours at room temperature (RT) under air. The reaction mixture was neutralized with saturated NaHCO 3 (aq) and extracted with CH 2 Cl 2 (3×100 mL). The organic extracts were combined, dried over Na 2 SO 4 and concentrated under vacuum to give a pale brown powder. This powder was purified by column chromatography (silica gel, 1% MeOH in CH 2 Cl 2 to 10% MeOH in CH 2 Cl 2 , Rf of product was 0.25 with 5% MeOH in CH 2 Cl 2 eluent). The fractions containing principally the desired product were collected together and evaporated under vacuum to give a white powder. This material was recrystallized from boiling MeCN (200 mL) to give pure product as small colourless cubes, 1.925 g (35% yield).
[0171] Starting Tetrahydroxy Calixpyrrole
[0172] 1 H NMR (400 MHz, D6-acetone, 25° C.)δ(ppm) 1.83 (s, 12 H), 1.88 (s, 6 H), 5.33 (d, J=8.2, 1 H), 5.99-6.06 (m, 8 H), 6.34 -6.40 (m, 3 H), 6.42 (ddd, J=7.8, 1.8, 1.0, 2 H), 6.55 (ddd, J=8.1, 2.5, 1.0, 2 H), 6.64-6.73 (m, 4 H), 6.80 (dd, J=2.5, 1.6, 2 H), 7.04 (t, J=7.9, 2 H), 7.07 (t, J=7.9, 2 H), 8.18 (s, 2 H), 8.53 (1 H), 8.73 (1 H), 8.77 (s, 2 H).
Example 2
Synthesis of Starting Octahydroxy Calixpyrrole (VIIb)
[0173]
[0174] Methanesulfonic acid (0.24 mL, 10.77 mmol, 3 equiv.) was added dropwise to a solution of pyrrole (0.25 mL, 3.6 mmol, 1 equiv.) in MeOH (6 mL). The mixture was stirred for 5 min and then a solution of dodecyl-(3′, 5′)dihydroxyphenyl ketone (X) (1.1 g, 3.6 mmol, 1 equiv.) in MeOH (18 mL) was added slowly. The reaction was stirred 20 h at RT. The reaction mixture was diluted with water (30 mL) and extracted with ethyl acetate (4×50 mL). The organic layers were combined, dried over sodium sulphate, and concentrated under vacuum. The material was purified by chromatography (silica gel; dichloromethane/ethyl acetate-8:2→6:4) affording a brownish solid that was recrystallized from acetonitrile to give the pure product, 245 mg (19% yield).
[0175] Starting Octahydroxy Calixpyrrole (VIIb) 1 H NMR (500 MHz, MEOD, 25° C.): 6 8.89 (bs, 4 H), 6.18 (d, J=2.0, 8 H), 6.15 (t, J=2.0, 4 H), 5.89 (d, J=2.4, 8 H), 2.30 (m, 8 H), 1.35 (m, 80 H), 0.89 (t, J=7.0, 12 H).
Example 3
Synthesis of Single Carbon-Bridge Calixpyrrole (type I)
[0176]
[0177] Starting tetrahydroxy calixpyrrole (VIIA) (41 mg, 55 μmol, 1 equiv.) and K 2 CO 3 (16 mg, 112 μmol, 2 molar equiv.) were added to a sealable tube. This tube was placed under vacuum for 10 hours to remove as much water as possible from the reagents. The sealed tube was purged with Argon three times. Dimethyl sulfoxide (DMSO) (5.3 mL, 10 mM) was added followed by bromochloromethane (3.6 μL, 55 μmol, 1 equiv.) and the tube was sealed. The turbid reaction mixture was placed in an oil bath set to 100° C. and stirred for 1 hour. The reaction mixture was cooled, the sealed tube was opened and the mixture was brought to ≈pH 2 with 1M HCl(aq). The resultant mixture was extracted with CH 2 Cl 2 (2×10 mL). The combined organic extracts were washed with water,dried over Na 2 SO 4 , and evaporated to give a light beige powder. This material was purified by column chromatography (silica gel, 1% MeOH in CH 2 Cl 2 to 10% MeOH in CH 2 Cl 2 , Rf of product is 0.33 with 4% MeOH in CH 2 Cl 2 eluent). Fractions containing the desired compound were collected together and evaporated under vacuum to give pure single carbon-bridge calixpyrrole as a white powder, 19 mg (44% yield).
[0178] Single Carbon-Bridge Calixpyrrole (type I)
[0179] 1 H NMR (400 MHz, D6-acetone, 25° C.)δ (ppm) 1.99 (s, 6 H), 2.00 (s, 6 H), 5.68 (t, J=3.0 Hz, 2 H), 5.77 (t, J=3.0 Hz, 2 H), 6.13 (d, J=2.6 Hz, 2 H), 6.18 (d, J=2.6 Hz, 2 H), 6.76-6.80 (m, 2 H), 6.90-6.97 (m, 4 H), 7.00 (d, J=7.9, 2 H), 7.07-7.15 (m, 6 H), 7.22 (t, J=7.9, 2 H), 7.49-7.69 (m, 6 H), 7.83 (s, 1 H), 7.95-8.03 (m, 4 H), 8.07 (s, 2 H), 8.48 (s, 1 H).
Example 4
Synthesis of Single in-Phosphonate-Bridge Calixpyrrole (type I)
[0180]
[0181] Triethylamine (0.22 mL, 1.6 mmol, 2.2 equiv.) followed by phenylphosphonic dichloride (0.11 mL, 0.80 mmol, 1.1 equiv.) were added to a solution of starting tetrahydroxy calixpyrrole (VIIA) (536 mg, 0.72 mmol, 1 equiv.) in THF (anhydrous and degassed, 55 mL, 13 mM) stirring at RT under Argon atmosphere. The reaction mixture was stirred at RT for 16 hours during which time a white precipitate was formed in the reaction mixture. At this time the reaction mixture was brought to ≈pH 2 with 1M HCl(aq) and the resultant mixture was extracted with CH 2 Cl 2 (3×100 mL). The organic extracts were combined, dried over Na 2 SO 4 and evaporated under vacuum to give a white powder. This material was purified by column chromatography (silica gel, 1 MeOH in CH 2 Cl 2 to 10% MeOH in CH 2 Cl 2 , Rf of the desired in-isomer is 0.40 with 5% MeOH in CH 2 Cl 2 as eluent, Rf of the undesired out-isomer is 0.45 with 5% MeOH in CH 2 Cl 2 as eluent). The fractions containing only the desired product were collected together and evaporated under vacuum to give pure material as a white powder. The fractions containing a mixture of the desired product and the undesired out-isomer were collected separately. These mixed fractions were concentrated under vacuum to give a white powder. This powder was dissolved as best as possible in boiling MeCN (10 mL). The hot mixture was passed through a simple paper filter into a round bottom flask.
[0182] The filter was washed through with another portion of hot MeCN (5 mL). Over one night, as the solution cooled small colourless crystals of the desired product were formed. Total single in-phosphonate-bridge calixpyrrole collected=119 mg (19% yield).
[0183] Single In-Phosphonate-Bridge Calixpyrrole (type I)
[0184] 1 H NMR (400 MHz, CDCl3, 25° C.)δ (ppm) 1.91 (s, 6 H), 2.01 (s, 6 H), 5.58 (d, J=2.6 Hz, 2 H), 5.78 (t, J=3.0 Hz, 2 H), 5.90 (d, J=3.1 Hz, 2 H), 6.15 (d, J=2.6 Hz, 2 H), 6.31 (s, 2 H), 6.44 (t, J=2.1, 2 H), 6.52 (dd, J=8.0, 2.4, 2 H), 6.66 (d, J=8.1, 2 H), 6.88, d, J=8.0, 2 H), 6.91 (t, J=1.9, 2 H), 6.99-7.05 (m, 4 H), 7.20 (t, J=7.9, 2 H), 7.57 (ddd, J=8.9, 7.1, 4.9, 2 H), 7.64-7.70 (m, 1 H), 7.92 (s, 1 H), 7.99 (ddd, J=14.5, 8.3, 1.3, 2 H), 8.23 (s, 2 H), 8.62 (s, 1 H).
[0185] Analogously to this process, the stereoisomer (Ia3) was obtained as a by-product of this reaction that can be separated from (Ia1) during the step of column chromatography under the conditions disclosed above.
Example 5
Synthesis of Di-Carbon-Bridged Calixpyrrole (type Ib)
[0186]
[0187] Starting tetrahydroxy calixpyrrole (VIIA) (40 mg, 54 μmol, 1 equiv.) and K 2 O0 3 (60 mg, 432 μmol, 8 molar equiv.) were added to a sealable tube. This tube was placed under vacuum for 10 hours to remove as much water as possible from the reagents. The sealed tube was purged with Argon 3 times. DMSO (5.3 mL, 10 mM) was added followed by bromochloromethane (18 pL, 270 μmol, 5 equiv.) and the tube was sealed. The turbid reaction mixture was placed in an oil bath set to 100° C. and stirred for 1 hour. The reaction mixture was cooled, the sealed tube was opened and the mixture was brought to≈pH 2 with 1M HCl(aq). The resultant mixture was extracted with CH 2 Cl 2 (2×10 mL). The combined organic extracts were washed with water, dried over Na 2 SO 4 , and the CH 2 Cl 2 was evaporated to give a light beige powder. This material was suspended in MeCN (1 mL), the mixture was sonicated and the MeCN was decanted. The remaining solid was dried under vacuum to give the pure di-carbon-bridged receptor (Ib10) as a white powder, 32 mg (77% yield).
[0188] Di-Carbon-Bridged Calixpyrrole (Ib10) 1 H NMR (300 MHz, CDCl3, 25° C.)δ (ppm) 1.85 (s, 12 H), 5.34 (d, J=7.9, 2 H), 6.04 (d, J=2.6 Hz, 4 H), 6.07 (d, J=2.6 Hz, 4 H), 6.17 (d, J=7.8, 2 H), 6.61-6.69 (m, 8 H), 6.71-6.76 (m, 4 H), 6.97 (t, J=7.9, 4 H), 8.75-9.35 (broad m, 4 H)
Example 6
Synthesis of In/Out-Diphosphonate Calixpyrrole (Ib8)
[0189]
[0190] Triethylamine (1.5 mL, 10.75 mmol, 20 equiv.) followed by phenylphosphonic dichloride (0.2 mL, 1.43 mmol, 2.6 equiv.) were added to a solution of starting tetrahydroxy calixpyrrole (VIIA) (406 mg, 0.55 mmol, 1 equiv.) in THF (anhydrous and degassed, 20 mL, 0.027 M) stirring at room temperature under Argon atmosphere. The reaction was stirred at room temperature for 16 hours during which time a white precipitate was formed in the reaction mixture. At this time the reaction mixture was brought to≈pH 2 with 1M HCl(aq) and the resultant mixture was extracted with CH 2 Cl 2 (3x 100 mL). The organic extracts were combined, dried over Na 2 SO 4 and evaporated under vacuum to give a white powder. The reaction crude was first purified by column chromatography (SiO 2 ; CH 2 Cl 2 : MeOH 99:1) in order to remove the oligomers/polymers formed during the reaction with 60% overall yield. The fraction containing the three diastereomers was purified by semipreparative HPLC (Spherisorb silica 250×20 mm, 5 μm; SiO 2 ; CH 2 Cl 2 : MeOH 99:1) to yield each separated isomer Ib9, Ib8 and Ib7 as white solids (Retention times: 4.8 minutes, 6.19 minutes and 9.8 minutes, respectively).
[0191] The three isomers can be further purified by crystallization from acetonitrile.
[0192] In/Out-Diphosphonate Calixpyrrole (Ib8)
[0193] 1 H NMR (400 MHz, CDCl3, 25° C.)δ (ppm) 1.99 (s, 6 H), 2.00 (s, 6 H), 5.68 (t, J=3.0 Hz, 2 H), 5.77 (t, J=3.0 Hz, 2 H), 6.13 (d, J=2.6 Hz, 2 H), 6.18 (d, J=2.6 Hz, 2 H), 6.76-6.80 (m, 2 H), 6.90-6.97 (m, 4 H), 7.00 (d, J=7.9, 2 H), 7.07-7.15 (m, 6 H), 7.22 (t, J=7.9, 2 H), 7.49-7.69 (m, 6 H), 7.83 (s, 1 H), 7.95-8.03 (m, 4 H), 8.07 (s, 2 H), 8.48 (s, 1 H).
[0194] In/In-Diphosphonate Calixpyrrole (Ib7)
[0195] 1 H-NMR (500 MHz, CD 2 Cl 2 , 25° C.):δ (ppm)=8.18 (bs, 4 H), 8.04 (m, J=14 Hz, J=7.3 Hz, J=1.2 Hz, 4 H), 7.71 (m, J=7.3 Hz, J=1.2 Hz, 2 H), 7.61 (m,
[0196] J=7.3 Hz, J=4.8 Hz, 4 H), 7.24 (t, J=7.9 Hz, 4 H), 7.02 (d, J=7.9 Hz, 4 H), 6.96 (d, J=7.9 Hz, H), 6.94 (s, 4 H), 6.17 (d, J=2.55 Hz, 4 H), 6.05 (d, J=2.55 Hz, 4 H), 1.80 ppm (s, 12 H).
[0197] Out/Out-Diphosphonate Calixpyrrole (Ib9)
[0198] 1 H-NMR (500 MHz, CD2Cl2, 25° C.):δ (ppm)=8.04 (bs, 2 H), 8.00 (m, J=14 Hz, J=7.3 Hz, J=1.2 Hz, 4 H), 7.70 (m, J=7.3 Hz, J=1.2 Hz, 2 H), 7.60 (m, J=7.3 Hz, J=4.8 Hz, 4 H), 7.49 (bs, 2 H), 7.26 (t, J=7.7 Hz, 4 H), 7.22 (d, J=7.7 Hz, 4 H), 7.18 (s, 4 H), 6.86 (d, J=7.7 Hz, 4 H), 6.32 (d, J=2.65 Hz, 4 H), 5.50 (bs, 4 H), 2.07 (s, 12 H).
Example 6 bis
Synthesis of Bisthiophosphonate Calix[4]Pyrrole Ib11, Ib12, and Ib13
[0199] The starting calix[4]pyrrole (VIIA) (0.4 g, 0.54 mmol) was dissolved in pyridine (42 mL, 52 mmol) (dried over CaH and freshly distilled) under argon atmosphere forming a colorless solution. Then, phenylphosphine dichloride (150 uL, 1.11 mmol) was added and the reaction mixture turned yellow. With time a white precipitate appeared. 1 h and 30 minutes after addition of the phosphine, the reaction mixture was heated at 70° C. and stirred for additional 30 minutes. After that time, sulfur (55.4 mg, 0.22 mmol) was added and the reaction was left under stirring at the same temperature overnight. Next day, the pyridine was removed under reduced pressure, and the crude was dissolved in 20 mL of dichloromethane (DCM). 10% HCl aq was added, and the aqueous phase was extracted with DCM 3×20 mL. Then the DCM extracts were combined and washed with 10% HCl aq 3×20 mL to remove the remaining pyridine. The DCM phase was dried over Na 2 SO 4 , filtered and concentrated under vacuum, yielding 0.51 g of crude. The crude of the reaction was purified by column chromatography (20g of SiO 2 ) and 6:4 dichloremethane (DCM):hexane as eluent mixture. compound (Ib11) eluted first (Rf=0.57, 109.1 mg 20% yield) followed by (Ib12) (Rf=0.38, 213.8 mg 39% yield) and (Ib13) (Rf=0.19, 82.9 mg, 15% yield).
[0200] Ib11 (i/i):
[0201] 1 H NMR (400 MHz, CDCl3, 25° C):δ (ppm) 8.12-8.02 (m, 6 H),7.96 (bs, 2 H),7.65-7.59 (m, 2 H),7.58-7.52 (m, 4 H), 7.18 (t, J=7.89 Hz, 4 H), 6.94 (d, J =7.89 Hz, 4 H), 6.84 (d, J=7.89 Hz, 4 H), 6.7 (s, 4 H), 6.17 (d, J=2.57 Hz, 4 H), 5.99 (s, 4 H),1.99 (s, 12 H); 31P{1 H}NMR (161.9 MHz,CDCl3, 25 ° C):δ (ppm) 85.6 (s); HRMS(ESI-TOF)m/z: [M+Na]+ calcd for C60 H50N4O4NaP2S2=1039.2641; Found 1039.2667.
[0202] Ib12 (i/o):
[0203] 1 H NMR (400 MHz, CDCl3, 25° C):δ (ppm) 8.25 (bs, 1 H), 8.15-8.06 (m, 6 H), 7.89 (bs, 1 H),7.67-7.52 (m, 6 H), 7.28-7.09 (m, 10 H), 6.88 (d, J=7.77 Hz, 2 H), 6.82 (s, 2 H), 6.77 (d, J=7.77 Hz,2 H), 6.21 (d, J=2.54 Hz, 2 H), 6.16 (d, J=2.54 Hz, 2 H), 5.65-5.60 (m, 2 H), 5.59-5.56 (m, 2 H), 2.06 (s, 6 H), 2.05 (s, 6 H); 31P{1 H}NMR (161.9 MHz,CDCl3, 25° C):δ (ppm) 85.0 (s), 79.0 (s) HRMS(ESI-TOF)m/z: [M +H]+ calcd for C60 H51N404P2S2=1017.2821; Found 1017.2838.
[0204] Ib13 (o/o):
[0205] 1 H NMR (400 MHz, CDCl3, 25° C):δ (ppm) 8.09-8.02 (m, 4 H),7.85 (bs, 2 H),7.64-7.58 (m, 2 H),7.57-7.49 (m, 4 H), 7.31(bs, 2 H), 7.29 (d, J=8.25 Hz, 4 H),7.20 (t, J=8.25 Hz, 4 H), 7.05 (s, 4 H), 6.75 (d, J=8.05 Hz, 4 H), 6.2 (d, J =2.62 Hz, 4 H), 5.26 (d, J=2.62 Hz, 4 H), 2.06 (s, 12 H); 31P{1 H}NMR (161.9 MHz,CDCl3, 25° C):δ (ppm) 78.9 (s); HRMS(ESI-TOF)m/z: [M +H]+ calcd for C60 H51N404P2S2=1017.2821; Found 1017.2872.
Example 7
Synthesis of Monomethyl-Monophosphonate-Bridged Calixpyrrole (type Ib1)
[0206]
[0207] Single in-phosphonate-bridge calixpyrrole (Ia1) (26 mg, 30 μmol, 1 equiv.) and K 2 CO 3 (33 mg, 241 μmol, 8 molar equiv.) were added to a sealable tube. This tube was placed under vacuum for 10 hours to remove as much water as possible from the reagents. The sealed tube was purged with Argon 3 times. DMSO (3 mL, 10 mM) was added followed by bromochloromethane (10 μL, 151 μmol, 5 equiv.) and the tube was sealed. The turbid reaction mixture was placed in an oil bath set to 100° C. and stirred for 1 hour. The reaction mixture was cooled, the sealed tube was opened and the mixture was brought to≈pH 2 with 1M HCl(aq). The resultant mixture was extracted with CH 2 Cl 2 (2×5 mL). The combined organic extracts were washed with water, dried over Na 2 SO 4 , and the CH 2 Cl 2 was evaporated to give a light beige powder. This material was purified by column chromatography (silica gel, CH 2 Cl 2 to 5% MeOH in CH 2 CO 2 , Rf of product is 0.70 with 1% MeOH i, n CH 2 Cl 2 eluent). The fractions containing only the desired product were collected together and evaporated under vacuum to give pure material as a white powder, 15 mg (57% yield).
[0208] Monomethyl-Monophosphonate-Bridged Calixpyrrole (Ib1)
[0209] 1 H NMR (500 MHz, CDCl3, 25° C.)δ (ppm) 1.94 (s, 6 H), 1.98 (s, 6 H), 5.56 (d, J=6.9, 1 H), 5.79 (d, J=7.0 Hz, 1 H), 5.81 (t, J=3.1, 2 H), 5.84 (t, J=3.1, 2 H), 6.07 (d, J=2.6 Hz, 2 H), 6.14 (d, J=2.6, 2 H), 6.58 (t, J=2.2, 2 H), 6.84 (d, J=7.8, 2 H), 6.88 (dd, J=8.0, 2.4, 2 H), 6.95-6.99 (m, 4 H), 7.04 (d, J=8.0, 2 H), 7.12 (t, J=7.9, 2 H), 7.24 (t, J=7.8, 2 H) 7.57 (td, J=7.6, 4.8, 2 H), 7.67 (t, J=7.5, 1 H), 7.84 (s, 1 H), 7.97 -8.04 (m, 4 H), 8.50 (s, 1 H).
[0210] Analogously to this process, the stereoisomer (Ib2) was obtained as a by-product of this reaction that can be separated from (Ib1) during the step of column chromatography under the conditions pointed out above.
[0211] Analogously, the compound (Ib3) can be obtained following the same process as the one for (Ib1) by replacing compound (Ia1) with a compound of formula (Ia4), obtainable by reaction of a compound of formula (VIIA) with dichlorophosphoramide, as described in Example 4.
[0000]
[0212] Analogously, the compound (Ib4) can be obtained following the same process as the one for (Ib1) by replacing compound (Ia1) with a compound of formula (Ia5), obtainable by reaction of a compound of formula (VIIA) with sulfuryl chloride, as described in Example 4.
[0000]
Example 8
Synthesis of In/Out/Out/Out-Tetraphosphonate Calixpyrrole (type Ic1)
[0213]
[0214] Triethylamine (1 mL, 7.03 mmol, 20 equiv.) followed by phenylphosphonic dichloride (0.25 mL, 1.76 mmol, 5 equiv.) were added to a solution of starting octahydroxy calixpyrrole VIIb (R=CH 3 , 500 mg, 0.35 mmol, 1 equiv.) in THF (anhydrous and degassed, 10 mL, 0.035 M) stirring at room temperature under Argon atmosphere. The reaction was stirred at room temperature for 2 hours during which time a white precipitate was formed in the reaction mixture. All solvent was removed from the reaction under vacuum and water (50 mL) was added. A grey precipitate was formed in the water mixture. This precipitate was collected by filtration. This material was purified by column chromatography (silica gel, CH 2 Cl 2 ) collecting the fractions containing the compounds that eluted first. These fractions were purified by semipreparative HPLC (Spherisorb silica 250×20 mm, 5 pm; SiO 2 ; CH 2 Cl 2 : Hexane 60:40; flow rate: 15 mL/min) to yield the desired product as a white solid (Retention time: 5.3 minutes). The product was further purified by recrystallization from acetonitrile to give the pure product 60 mg, (9%).
[0215] In/Out/Out/Out-Tetraphosphonate Calixpyrrole (type Ic1)
[0216] 1 H NMR (400 MHz, CDCl3, 25° C.):δ (ppm) 7.97 (m, 8 H), 7.79 (t, J=2.3, 1 H), 7.76 (t, J=3.0, 2 H), 7.72 (t, J=2.3, 1 H), 7.66 (m, 4 H), 7.55 (m, 8 H), 7.46 (t, J =2.0, 2 H), 7.46 (t, J=2.0, 2 H), 7.46 (t, J=2.0, 2 H), 6.81 (t, J=2.0, 2 H), 6.77 (t, J=3.3, 2 H), 6.55 (t, J=3.3, 2 H), 6.18 (d, J=2.3, 2 H), 6.15 (t, J=3.0, 2 H), 6.12 (t, J=3.0, 2 H), 6.08 (d, J=2.3, 2 H), 2.45 (m, 8 H), 1.27 (m, 80 H), 0.89 (t, J=7.0, 12 H).
Example 8 bis
Synthesis of Tetraphosphonate Calixpyrroles (Ic3) and (Ic4)
[0217]
[0218] To a solution of calix[4]pyrrole (VIII) (500 mg, 0.352mmo1) in dry THF (10 mL) and freshly distilled triethylamine (0.980 mL, 7.03 mmol), phenylphosphonic dichloride (0.247 mL, 1.758 mmol) was added dropwise under argon atmosphere. The reaction mixture was stirred for 2 hrs at room temperature. The solvent was removed in vacuo and water (50 mL) was added. The grey precipitate was filtered off and purified by column chromatography (SiO 2 ; CH 2 Cl 2 ) in order to remove the oligomers/polymers formed during the reaction. The fraction containing the two diastereomers was purified by semipreparative HPLC (Spherisorb silica 250×20 mm, 5 pm; SiO 2 ; CH 2 Cl 2 : Hexane 60:40; flow rate: 15 mL/min) to yield each separated isomer Ic3 and Ic4 as white solids (Retention times: 4.3 minutes and 5.3 minutes, respectively). The isomers can be further purified by crystallization from acetonitrile.
[0219] Experimental Data for Ic3:
[0220] 1 H-NMR (400 MHz, CDCl 3 , 25° C.): δ (ppm)=7.94 (m, 8 H), 7.65 (m, 4 H), 7.53 (m, 8 H), 7.53 (bs, 4 H), 7.37 (d, 4 J H-H ˜1.75 Hz, 8 H), 6.56 (t, 4 J H-H ˜1.75 Hz, 4 H), 6.17 (d, 4 J H-H ˜2.27 Hz, 8 H), 2.45 (m, 8 H), 1.27 (m, 80 H), 0.88 (t, 3 J H-H ˜7.0 Hz, 12 H). 31 P-NMR: δ (ppm)=13.63. 13 C-NMR:δ (ppm)=151.5, 151.4, 136.2, 133.4, 131.4, 131.3, 128.8, 128.6, 116.8, 106.6, 49.0, 39.0, 31.9, 30.2, 29.8, 29.7, 29.6, 29.3, 24.7, 22.7, 14.3. HR-MALDI-MS: m/z calculated for C 116 H 144 N 4 O 12 P 4 1908.9731, found 1908.9699; FT-IR v (cm-i) 2921-2851, 1592, 1426, 1293.
[0221] Experimental data for Ic4 (white powder, 9%). 1 H-NMR (400 MHz, CDCl 3 , 25° C.):δ (ppm)=7.97 (m, 8 H), 7.79 (t, 4 J H-H ˜2.3 Hz, 1 H), 7.76 (t, 4 J H-H ˜3.0 Hz, 2 H), 7.72 (t, 4 J H-H ˜2.3 Hz, 1 H), 7.66 (m, 4 H), 7.55 (m, 8 H), 7.46 (t, 4 J H-H ˜2.0 Hz, 2 H), 7.46 (t, 4 J H-H ˜2.0 Hz, 2 H), 6.81 (t, 4 J H-H ˜2.0 Hz, 2 H), 6.77 (t, 4 J H-H ˜3.3 Hz, 2 H), 6.55 (t, 4 J H-H ˜3.3 Hz, 2 H), 6.18 (d, 4 J H-H ˜2.3 Hz, 2 H), 6.15 (t, 4 J H-H ˜3.0 Hz, 2 H), 6.12 (t, 4 J H-H ˜3.0 Hz, 2 H), 6.08 (d, 4 J H-H ˜2.3 Hz, 2 H), 2.45 (m, 8 H), 1.27 (m, 80 H), 0.89 (t, 3 J H-H ˜7.0 Hz, 12 H); 31 P-NMR:δ (ppm)=14.37, 12.96. 13 C-NMR:δ (ppm)=151.8, 151.4, 151.3, 151.2, 149.1, 149.0, 136.8, 136.4, 136.1, 133.6, 133.4, 131.5, 131.4, 131.3, 131.2, S5 131.1, 128.9, 128.7, 128.6, 128.0, 127.9, 127.1, 126.4, 126.3, 125.5, 118.6, 118.0, 117.5, 117.4, 112.1, 112.0, 108.9, 108.8, 108.7, 106.0, 105.8, 105.7, 105.5, 48.9, 48.8, 39.0, 38.9, 31.9, 30.2, 30.1, 29.9, 29.8, 29.6, 29.5, 29.3, 24.8, 24.6, 22.7, 14.1. HRMALDI-MS: m/z calculated for C 116 H 144 N 4 O 12 P 4 1908.9731, found 1908.9866; FT-IR v(cm −1 ) 2921-2850, 1593, 1430, 1294.
Example 9
Membrane Composition
[0222] 3.63 mg of creatinine ionophore (Ib1), 1.00 mg of cation-exchanger salt (potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (KTFPB)), 31.37 mg of polymeric matrix polyvinyl chloride (PVC) of high molecular weight (manufacturer's reference 81387-250G) and 64.00 mg of plasticizer o-nitrophenyl octyl ether (o-NPOE) are mixed in 1 mL of tetrahydrofuran (THF), as shown in the table below (Table 1). This mixture is vigorously shaken in a bath sonicator for 30 minutes until obtaining a transparent solution ready for deposition.
[0223] The same membrane composition as above was prepared but in the absence of the ionophore (hereinafter also referred as “blank membrane”).
[0000]
TABLE 1
Composition of a blank and a creatinine
potentiometric sensing membrane.
% weight
Blank
Creatinine
Compound
membrane
membrane
Ionophore
—
3.63
KTFPB
1.00
1.00
PVC
33.0
31.37
o-NPOE
66.0
64.00
THF (solvent)
1 mL
1 mL
[0224] All the components for each membrane were simply mixed and stored for their posterior use in the manufacture of the electrode.
[0225] Analogously, membranes comprising ionophores (Ia1), (Ib7), (Ib8), (Ib9), (Ib10), (Ib11), (Ib12), (Ib13), (Ic3) and (Ic4) were prepared following the same procedure as the one followed for the membrane comprising ionophore (Ib1), but using the amounts (expressed in milligrams) specified in Table 1bis below:
[0000]
TABLE 1bis
Compound
Blank
Ia1
Ib7
Ib8
Ib9
Ib10
Ib11
Ionophore
—
3.2
3.63
3.63
3.63
2.75
3.7
KTFPB
1
1
1
1
1
1
1
PVC
33
32
31.37
31.37
31.37
32.25
31.7
o-NPOE
66
63.8
64
64
64
64
63.6
Compound
Blank
Ib12
Ib13
Ic3
Ic4
Ionophore
—
3.7
3.7
4.02
4.02
KTFPB
1
1
1
1
1
PVC
33
31.7
31.7
31.98
31.98
o-NPOE
66
63.6
63.6
63
63
In 1 mL THF
Example 10
Manufacturing of the Electrode
[0226] The body of each creatinine-selective electrode was made of glassy carbon (HTW) (GC) rod (length=50 mm, diameter=3 mm) inserted into a Teflon body (RS Amidata) (length=40 mm, outer diameter=6 mm). The GC surface was polished with alumina of different sizes (25, 1 and 0.03 μm, Buehler, USA), with an active surface of 7 mm 2 .
[0227] Solid-Contact Ion-Selective Electrode:
[0228] The next step is to drop-cast 50 μL of the polymeric membrane solution obtained in Example 9, onto the above conductor and let the solvent evaporate for up to 2 hours. Once the membrane was fully dried onto the conductor, the membrane was subjected to a conditioning step by submerging it into a 10 mM acetic acid/acetate buffer solution containing 10 mM creatinine for 1 hour. This conditioning step was suitable in order to obtain stable measurements when calibrating and measuring with creatinine as well as real samples, respectively.
[0229] The same protocol was repeated for the blank membrane composition as well as for the membrane compositions provided in Table 1bis above.
[0230] Ion-selective electrode with inner filling solution electrode:
[0231] In the case of ion-selective electrode with inner filling solution, 50 μL of the polymeric membrane obtained in previous Example 9, were drop-casted on a glass-casting plate. The membrane was gently peeled off and placed in the membrane packing piece of the electrode (Electrode Body ISE, 45137 Sigma Aldrich) and finally pressed with the membrane housing to put the membrane in contact with the inner electrolyte solution, which is 10mM of creatinine in 10mM acetic acid/acetate buffer solution. The final step was the calibration step, wherein the polymeric membrane was placed in contact with a 10 mM creatinine solution and a 10 mM acetic acid/acetate buffer solution to obtain stable potential readings without noise coming from the first contact of the membrane to the solution.
[0232] The same protocol was followed with the blank membrane composition.
[0233] Calibration measurements: The measurements were carried out with an acetic acid/acetate buffer solution of 10 mM and the concentration of creatinine was increased by adding amounts of creatinine standards.
Example 11
Design of a Potentiometric Cell Device
[0234] The potentiometric cell assembly consists basically in measuring the potential generated between two electrodes: a Ag/AgCl reference electrode (A double junction Ag/AgCl/KCI 3 M reference electrode containing 1 M LiAcO as electrolyte bridge, type 6.0729.100 was employed (Metrohm AG))that maintains a constant potential, due to the presence of a high concentrated KCI electrolyte coupled to a bridge electrolyte and the sample through a liquid junction; and an ion-selective electrode, which included the creatinine selective membrane or the blank membrane. This ion-selective electrode can be either any of the polymeric membranes of Example 9 (Tables 1 and 1 bis) in contact with an inner filling solution of 10 mM of creatinine with 10 mM buffer solution at in contact with an Ag/AgCl wire, or the polymeric membrane in contact with a glassy carbon rod as a solid-state ion-selective electrode, in direct contact with the sample.
[0235] The measuring circuit is assembled in order to be able to record the electromotive force generated between these electrodes by a voltmeter, which may explain the presence or absence of the target analyte.
Example 12
Limit of Detection/Linear Range/Response Time
[0236] Stock solutions of creatinine at different concentrations from 10 −7 to 10 −2 M were prepared. Then, potentiometric measurements were made using the potentiometric cells comprising the solid electrode either with the membrane comprising the compound of the invention Ib1 or the blank membrane. The results are summarized in FIG. 1 .
[0237] Additions of one logarithmic activity unit were added into the potentiometric cell in order to obtain a potentiometric trace of the sensor as well as a calibration curve, where linear regression and performance of the sensor can be tested out.
[0238] A linear regression was made from the data obtained, obtaining FIG. 2 . From this figure the parameters shown in Table 2 below were obtained:
[0000]
TABLE 2
Potentiometric parameters of the blank
and the creatinine polymeric membrane
Blank
Creatinine
Parameter
membrane
membrane
Sensitivity (mV/log a creatinine )
58.4 ± 0.5
54.2 ± 0.6
Limit of detection (M)
10 −4.7
10 −6.2
Linear range (M)
10 −4 -10 −2
10 −6 -10 −2
Response time (s)
15
10
a creatinine = concentration of creatinine
[0239] Sensitivities close to ideal 59.2 mV/log a creatinine mean that the sensor is sensing creatinine following the analytical Nernst equation.
[0000] E=E°− 0.0592loga creatinine
[0240] As it can be concluded from Table 2, including a compound of the invention the limit of detection is improved in more than one order and the sensitivity is appropriate (adjusted to Nernstian response). The fact that the response is linear for a broader range of concentration is indicative of its stability and usability as potentiometric sensor.
Example 13
Interferences
[0241] In this section the selectivity of the electrode of the invention was determined measuring the potential value in different solutions prepared as in the example above. The potentiometric cell used was the one with the solid-contact ion-selective electrode as disclosed in Example 10 with ionophore (Ib1).
[0242] The calculation of the selectivity coefficients is achieved by the separate solution method (SSM) following the protocol disclosed by Umezawa, Y. et al., (Umezawa et al., “” Pure Appl. Chem. 2000, 72, 1851-2082). where the ion-selective electrode is calibrated with the selected interferences at 10 mM. The selectivity coefficients are calculated against the main cations present in biological fluids -urine, serum and plasma- (see Table 3). Comparing the calculated coefficients with the required ones is the first step to demonstrate that the sensor may predict creatinine accurately in real sample measurements.
[0000]
log
K
A
,
B
POT
=
(
E
B
-
E
A
)
z
A
F
2.303
RT
+
(
1
-
z
A
z
B
)
log
a
A
[0243] where:
E A and E B stand for the potential contribution of analyte and interference, respectively. a A and z A are the activity and the charge of the analyte, respectively. a B and z B are the activity and the charge for the interfering ion. R is the universal gas constant (8.31 J mol −1 K −1 ), T is temperature (K) and finally F is the Faraday constant (96485 A mol −1 ).
[0248] The same protocol was followed with the potentiometric cell comprising the membrane blank.
[0000]
TABLE 3
Selectivity values calculated by separate-solution
method expressed as log K POT creatinine .
Blank
Creatinine
Typically
Interferent
sensor
sensor
Required
Citric Acid
−2.9 ± 0.1
−4.6 ± 0.2
0.54
NaHCO 3
−2.6 ± 0.1
−4.0 ± 0.1
−0.55
Urea
−2.6 ± 0.1
−4.3 ± 0.1
−1.30
Ca 2+
−3.4 ± 0.1
−4.8 ± 0.1
0.52
Na +
−2.6 ± 0.1
−3.7 ± 0.1
−2.1
NH 4 +
−1.5 ± 0.1
−2.3 ± 0.1
−0.55
K +
−1.2 ± 0.1
−2.5 ± 0.1
−2.0
Creatine
−2.4 ± 0.1
−3.5 ± 0.1
—
[0249] A negative value is indicative of the selectivity of the sensor, and the more negative the value is, the more selective is the electrode. From Table 3 it can be concluded that the sensor comprising the compound Ib1 of the invention is more selective, particularly in terms of the selectivity towards potassium, which is a serious interference commonly found in biological fluids.
[0250] The “required selectivity coefficient” calculation is based on the known concentration range of the analyte and the interfering ion in the sample (biological fluids, such as urine).
[0251] The required selectivity coefficients were calculated using the following equation:
[0000] Log K =log C B −log C A
[0252] Where C B and C A stand for the concentration of the interfering anion and the analyte, respectively.
[0253] Considering that the values of the coefficients are inferior to the required ones, particularly for K + , many of the interferences may not affect the measurements in real samples.
[0254] The same protocol was followed with the membrane compositions listed in Table 1bis in the form of electrodes as disclosed in Example 10. The results are summarized in Table 3bis below. Again, the coefficient values obtained were inferior to the required ones, which is an indicia that interferences may not affect creatinine measurements in real samples. Therefore, from these data it can be concluded that the compounds of the invention are creatinine selective.
[0000]
TABLE 3bis
No
ionophore
Ia1
Ib7
Ib8
Ib9
Req.
Citric acid
−2.9 ± 0.1
−3.8 ± 0.1
−3.6 ± 0.1
−2.8 ± 0.1
−3.7 ± 0.1
0.54
NaHCO 3
−2.6 ± 0.1
−3.9 ± 0.1
−3.5 ± 0.1
−3.1 ± 0.1
−3.2 ± 0.1
−0.55
Urea
−2.6 ± 0.1
−3.7 ± 0.1
−3.4 ± 0.1
−3.6 ± 0.1
−3.7 ± 0.1
−1.30
Ca 2+
−3.4 ± 0.1
−4.3 ± 0.1
−3.9 ± 0.1
−4.0 ± 0.1
−3.7 ± 0.1
0.52
Na +
−2.6 ± 0.1
−3.1 ± 0.1
−3.2 ± 0.1
−2.6 ± 0.1
−2.9 ± 0.1
−2.1/−1.2
NH 4 +
−1.5 ± 0.1
−2.1 ± 0.1
−2.2 ± 0.1
−1.9 ± 0.1
−1.6 ± 0.1
−0.55
K +
−1.2 ± 0.1
−2.1 ± 0.1
−2.0 ± 0.1
−2.3 ± 0.1
−2.0 ± 0.1
−1.5
Creatinine
−2.4 ± 0.1
−3.1 ± 0.1
−2.8 ± 0.1
−2.4 ± 0.1
−2.9 ± 0.1
—
No
ionophore
Ib13
Ic3
Ic4
Req.
Citric acid
−2.9 ± 0.1
−3.9 ± 0.1
−3.6 ± 0.1
−3.5 ± 0.1
0.54
NaHCO 3
−2.6 ± 0.1
−3.6 ± 0.1
−3.3 ± 0.1
−3.2 ± 0.1
−0.55
Urea
−2.6 ± 0.1
−4.8 ± 0.1
−3.2 ± 0.1
−3.2 ± 0.1
−1.30
Ca 2+
−3.4 ± 0.1
−3.9 ± 0.1
−3.9 ± 0.1
−3.9 ± 0.1
0.52
Na +
−2.6 ± 0.1
−3.0 ± 0.1
−3.1 ± 0.1
−3.0 ± 0.1
−2.1/−1.2
NH 4 +
−1.5 ± 0.1
−1.7 ± 0.1
−2.0 ± 0.1
−2.0 ± 0.1
−0.55
K +
−1.2 ± 0.1
−1.6 ± 0.1
−1.8 ± 0.1
−1.7 ± 0.1
−1.5
Creatinine
−2.4 ± 0.1
−3.5 ± 0.1
−2.6 ± 0.1
−2.6 ± 0.1
—
Example 14
Real Sample Measurement
[0255] The creatinine selective polymeric membrane can be used to facilitate daily measurements by physicians, technicians, among others in the laboratories that require rapid, simple and easy-to-use instrumentation to obtain analytical results.
[0256] The electrode used was the solid type with the ionophore of the invention of formula (Ib1).
[0257] Urine
[0258] The sample is collected at any time followed by a 100 fold dilution with a 0.05 M buffer at pH around 3.7. This step ensures the creatinine to be charged. After that, the potential generated can be recorded with the high-input impedance voltmeter. Electrodes must be cleaned in between measurements with abundant distilled water.
[0259] The same samples were also analysed using Jaffe method using the kit commercialized by Sigma-Aldrich, with manufacturer's reference MAK080-1 KT.
[0260] The results are summarized in FIG. 4 .
[0261] Plasma
[0262] In the case of plasma and serum, the sample must be also diluted although in this case the dilution is only 10 times since the amount in both samples is 2 times lower. The sample is collected and diluted 1:10 with a pH 3.7 buffer 0.05 M to obtain the charged creatininium ion. As in the previous sample, the potential is therefore recorded with the voltmeter. Longer response times have been observed after several serum/plasma samples measurements.
[0263] The same samples were also analysed using Jaffé method as above.
[0264] The results are summarized in Table 4:
[0000]
TABLE 4
Creatinine values obtained from different plasma samples for the standard
method (Jaffé) and the potentiometric method developed here.
Jaffé Method
Potentiometric
Plasma samples
(mM)
method (mM)
1
0.33
0.36
2
0.57
0.62
3
0.31
0.33
4
0.24
0.29
[0265] As one can see, the electrode of the invention is a reliable tool in the measurement of creatinine in real samples.
REFERENCES CITED IN THE APPLICATION
[0266] Jacobs, R. M.; et al., “Effects of Interferents on the Kinetic Jaffe Reaction and an Enzymatic Colorimetric Test for Serum Creatinine concentration Determination in Cats, Cows, Dogs and Horses”, E. Can. J. Vet. Res., 1991, v. 55,150-154.
[0267] Dimeski, C et al., “Ion Selective Electrodes (ISEs) and interferences—A review”, Clin. Chim. Acta, 2010, v. 411,309-317.
[0268] Meyerhoff, M. et al., “An activated enzyme electrode for creatinine”, Anal. Chim. Acta, 1976, v. 85,277-285.
[0269] Bühlmann, P. et al., “Influence of Natural, Electrically Neutral Lipids on the Potentiometric Responses of Cation-Selective Polymeric Membrane Electrodes”, Anal. Chem., 2001, v. 73,3199-3205.
[0270] Hassan, S. “Novel Biomedical Sensors for Flow Injection Potentiometric Determination of Creatinine in Human Serum”, Electroanalysis, 2005, v. 17, 2246-2253.
[0271] Ballester P. “Switching from Separated to Contact Ion—Pair Binding Modes with Diastereomeric Calix[4]pyrrole Bis-phosphonate Receptors”, J. Am. Chem. Soc., 2012, v. 134, 13121-13132.
[0272] Bakker E., et al., “Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 1. General Characteristics” Pretsch Chem. Rev., 1997, v. 97, 3083-3132.
[0273] Tanji yin and wei qin, “Applications of nanomaterials in potentiometric sensors”, Trends in Analytical Chemistry, 2013, 51, 79-86.
[0274] Umezawa et al., “Applications of nanomaterials in potentiometric sensors”, Pure Appl. Chem. 2000, 72, 1851-2082.
[0275] Galán A. et al., “Synthesis, structure, and binding properties of lipophilic cavitands based on a calix[4]pyrrole-resorcinarene hybrid scaffold”, J. Org. Chem., 2014, 79, 5545-5557.
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Compounds are of the formula (Ia), (Ib), (Ic), or are stereoisomers thereof, wherein: R1 is hydrogen, (C1-C20)alkyl; (C3-C20)alkenyl; (C3 C20)alkynyl; (C1-C6)alkyl-O—; (C3-C20)cycloalkyl; (C1 C20)haloalkyl; (C6-C20)aryl optionally substituted; (C6-C20)heteroaryl optionally substituted; R2 and R2′ are hydrogen; (C1-C20)alkyl; (C1-C6)alkyl-O—; (C1-C6)haloalkyl; halogen;cyano; and nitro; Z1 to Z4 are diradicals of formula (III) wherein Al and A2 are O—or —NR3-, wherein R3 is selected from the group consisting of hydrogen and (C1-C20)alkyl; and G is (C1-C6)alkyl; —P(═S)R5-; —P(═O)R4; P(═O)(OR4)-; —P(═O)(NR6R7)-; —S(=0)2-; S(═O)—; or —C(═O)—; and Y1 to Y4 are (C1-C8)alkyl; (C3-C7)cycloalkyl; (C6-C20)aryl optionally substituted; or (C6-C20)heteroaryl optionally substituted; and FG1 and FG2 are H, OH, or NHR8.
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BACKGROUND OF THE INVENTION
The present invention relates to a a flexible cam system for actuating mechanisms mounted on a revolving assembly, mainly on a rotary furnace provided with means for the delivery of air-steam-gas mixture under the layer of a bulk-material suspension being heat-treated therein.
The invention is intended to control a rotary furnace during rotation thereof by acting mechanically on various mechanisms, e.g. valves, drives of burners, etc., mounted on the furnace body, so as to provide a specified sequence of their operation determined by the requirements of a given production process.
The present invention can be used in the building-material industry, primarily in roasting cement clinker where the processed mix therefor is blended with chlorides, for the delivery of an air-steam-gas mixture to treat the granular cake suspension during the removal of said chlorides therefrom, and in roasting plain cement clinker for the delivery of an air-steam-gas mixture under the layer of the mix suspension being processed for intensive calcination thereof. In addition, the invention can be used for the delivery of air under the layer of a bulk material cooled in a pipe cooler after roasting in a furnace.
The invention can also be used elsewhere, e.g. in metallurgy, for reducing iron ore in rotary furnances wherein a gas-reducer is delivered under the ore layer, and in the chemical industry for some processes carried out in rotary furnaces.
As is known, the granular cake obtained from a cement mix containing chlorides is freed from these. To do this, the caked granules are suspended in the revolving furnace by the delivery thereinto, under the layer of said granules, of an air-steam-gas mixture. The delivery of the mixture is accomplished by means of burners fitted with suitable valves to control the flow of various gaseous agents used. The same type of burners is employed on rotary furnaces fitted for intensive calcination of cement mixes and for reducing iron ores. The gaseous agents used are delivered to the layer of the mix being treated in a sequence specified for a given process. To effect the required sequence of operations of the burners valves, use is made of various tracer means.
Know flexible cam device has a frame mounted on a carriage which runs on rails layed along a furnace assembly, which frame carries a suitable guide means. The working face of the guide means is oriented at right angles to the furnace body. The carriage with the frame thereon is connected to a drive of a special system whereby the frame is capable of following the axial movement of the furance.
This device, however, suffers from a number of disadvantages, among which are: a guide track which is costly to manufacture, a complex cam system to follow axial movements of the furnace, lack of adjustments on the entrance and exit portions of the guide track, and lack of place for additional guide tracks.
There is also known a cam device for actuating mechanisms mounted on a revolving assembly, having a supporting frame located about the mechanisms and guide tracks mounted on the frame indirectly through servodrives thereof. The frame has an annular shape and is mounted by means of supporting rollers on ring-shaped rails affixed on the body of the assembly.
Although it remedies some disadvantages of the above device, this cam device is complex in construction and creates some substantial extra load on the rotary-furnace body. If the rollers of the frame stick on rails which are layed on the furnace body, the mechanisms actuated by the cam device may be damaged. This device must be mounted with great accuracy, and its running and maintenance are cumbersome.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide for reliable operation of a cam device with considerable axial and radial displacements of a revolving assembly.
Another object of the invention is to provide a cam device which is simple in construction and convenient for handling.
These and other objects of the invention are attained in a cam device for actuating mechanisms mounted on a revolving assembly, having a supporting frame positioned at the place where the mechanisms are fixed on the revolving assembly mechanisms, and guide tracks attached to the frame through regulating drive mechanisms, wherein, according to the invention, the guide tracks are flexible and provided with balance weights attached thereto, and said regulating drive mechanisms are mounted on opposite sides of said supporting frame and respectively attached each to one end of each of said guide tracks rigidly, and to the other end thereof, movably, through guide rollers secured to these drive mechanisms.
Cables may be used as the guide tracks.
Conveyor bands may also be used as the guide tracks.
The use of flexible guide tracks provided with balance weights in a device according to the invention makes it possible for the device to follow axial and radial displacements of the revolving assembly and the controlled mechanisms mounted thereon.
The location of the regulating drive mechanisms on opposite sides of the frame facilitates a simpler mounting and adjustment of the guide tracks.
The guide tracks in the form of cables provide the necessary flexibility thereof and resistance to wear caused by the contact of the follower rollers of said controlled mechanisms of said revolving assembly, and also reliable operation at high temperatures of the furnace assembly.
The guide tracks in the form of conveyor bands provide for improved operating reliability without much wear thereof caused by the slippage of the follower rollers of the controlled mechanisms along the entrance and exit portions of the guide tracks, and also for uniform distribution of loads on the controlled mechanisms.
The novel features of the present invention consist in the following.
The introduction of flexible guide tracks provided with tensioning weights attached thereto, so that one end of each of the flexible guide tracks is connected to a respective regulating drive mechanism rigidly, and the other end thereof, movably, through guide rollers of the drive mechanisms, ensures reliable operation of the cam device, and facilitates its manufacture, installation and servicing.
The use of cables as the flexible guide tracks provides for a simple construction and reliable operation of a cam device at high ambient temperatures.
The use of conveyor bands as the flexible guide tracks also provides for a simple construction and reliable operation of a cam device, because wear of the guide tracks on the entrance and exit portions thereof caused by the contact friction of the follower rollers of controlled mechanisms is drastically reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more apparent by reference to the following detailed description of an exemplary embodiment thereof taken in conjunction with the accompanying drawings. In the drawings:
FIG. 1 is a front elevation view, partly in section, of a tracer device mounted on a rotary furnace, with controlled mechanisms mounted thereon.
FIG. 2 is a side elevation view of the tracer device and a longitudinal view of the rotary furnace, with said controlled mechanisms mounted thereon being conditionally represented by one of the follower levers seen in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, the tracer device has a supporting frame 1 made, for instance, in the form of channel-section rolled steel, which is positioned about a body 2 of a rotary furnace at the place where mechanisms to be actuated are mounted on the furnace body.
The frame 1 in this embodiment of the invention is made of channel-section rolled-steel bars. Vertical bars 3 make up rails in which are guidably mounted regulating drive mechanisms in the form of carriages 4 with rollers 5. The carriages 4 are provided with mechanisms for imparting movement thereto in a vertical plane, said mechanisms being composed of lead screws 6 mounted in support members 7 which are secured on a cross brace 8 between the vertical bars 3, and nuts 9 meshing with the lead screws 6, which are rigidly secured to the carriages 4. Side edges of the carriages 4 carry brackets with axles 10 which extend through suitable vertical slots 11 provided in the bars 3. The axles 10 carry thereon guide rollers 12. Parallel cables 13 form a bottom guide track. The ends of the cable 13 which form entrance portions 14 of the guide track are rigidly attached to the right-hand carriage 4. The ends of cables 13 which form exit portions 15 of the guide track carry balance weights 16 and rest on the guide rollers 12.
Two parallel cables 17 form a flexible top guide track. The cables 17 are stretched between the vertical bars of the frame 1 so that the right-hand ends of the cables are rigidly secured thereto, and the left-hand ends carry tensioning weights 19. The cables are guided on guide rollers 18 attached to the left-hand bars of the frame 1. The cables 17 are tied to each other by means of a beam 20 which is connected through a cable 21 to a lever 22 of a drive mechanism 23.
According to the present embodiment of the invention, the mechanisms under control comprise control levers 24 adapted to act on valves 25 normally closed by suitable springs incorporated therein (not shown in the drawings). The valves 25 are rigidly mounted in the body 2 of the rotary furnace and used to regulate the rate of flow of an air-steam-gas mixture delivered to the layer of the material being processed. The levers 24 are pivotally mounted on pins 26 and provided with rollers 27 in the form of tubular members whose length is 2.5 to 3 times the axial displacement of the frame 1. The levers 24 are connected to the valves 25 by means of links 28. The working travel of the levers 24 is limited by adjustable stop elements 29 suitably located on the body 2 of the rotary furnace. The bottom guide track serves to actuate the opening of the valves 25 as these pass by under the layer of the material being inside the furnace. The top guide track serves to actuate a periodic blasting of the valves 25 that come out of contact with the material in order to remove its particles therefrom.
The tracer device according to the invention operates as follows. The left and right-hand carriages 4 are set in position by turning the lead screws 6 so that the parallel cables 13 under the pull of the balance weights 16 press the levers 24 of the valves 25 that are underneath the layer of the material against the respective stop elements 29. The mass of the balance weights 16 is determined so as to overcome the pressure of the springs within the valves 25 and to press the levers 24 against the stop elements 29. As the furnace revolves clockwise (as shown in FIG. 1), the rollers 27 on the levers 24 engage the entrance portions 14 of the cables 13 and, owing to the ever decreasing clearance between the cables and the furnace, the levers 24 turn towards the furnace body 2, pull the links 28 and thereby gradually open the valves 25 that pass by under the layer of the material. Thereupon, an air-steam-gas mixture is injected into the layer of the material for suspension thereof. The levers remain pressed against the stop elements 29 on a certain length of the cables, and hence the valves 25 remain opened as much as is permitted by the position of the adjustable stop elements 29. As the furnace continues to revolve, the clearance between its body 2 and the exit portions 15 of the cables 13 gradually increases, and the levers 24 under the action of the valve springs are brought back to their initial position. The valves 25 are closed, stopping the delivery of the gaseous components to the material. When the length of the entrance portion 14 and the exit portion 15 of the bottom guide track and the time of the delivery of the gaseous components to the layer of the material being under treatment needs to be increased, the carriages 4 are lifted by the aid of their drive mechanisms. When the active length of the guide track needs to be reduced, the carriages 4 are lowered. For the complete withdrawal of the guide track from its working position, which is done, for instance, during the firing of the furnace or for stopping the delivery of gaseous agents to the material under treatment, the carriage 4 with the balance weights 16 is lowered until the latter engage some limiting surface (the furnace foundation, as exemplified in the drawings). As this happens, the cables slacken so that they cannot press the levers 24 against the stop elements 29. Since the left-hand ends 15 of the cables 13 are movably connected to the frame 1, radial displacements of the furnace body 2 or some misalignment of the levers 24 mounted thereon do not affect the guide track and the control mechanisms, which otherwise might be damaged. Here, the guide track follows the furnace radial displacements. Axial displacements of the furnace are compensated for by the rollers 27 which have an adequate length, as mentioned in the foregoing, and while moving together with the furnace body 2 relative to the cables 13, the rollers never lose contact therewith. The top guide track 17 operates on the same principle as the bottom one, only it is withdrawn from its working position by lifting some distance the balance weights 19. At this time, the lever 22 through the cable 21 moves the beam 20 upwards, which, in turn, lifts the weights 19. The top guide track is brought into action periodically for blasting the valves 25 in the upper position thereof on the furnace body 2. In the illustrated embodiment, the carriages 4 are driven manually by turning the lead screws 6.
It is possible to mount on the flexible cam system an electromechanical drive with remote control thereof, whereby the top guide track is automatically activated and the bottom guide track is automatically withdrawn. It becomes necessary in the case of emergency, for example, when the gaseous agents are shut off and the valves may be damaged by quantities of the material being processed which get thereinto. To exclude this, the valves that pass under the layer of material must be closed and then opened as they come out of contact therewith to allow their chambers to be emptied of some particles of the material, which go out by gravity.
During heat treatment of a cake obtained by roasting of a cement mix with chlorides, in the calcination of plain cement mixes, and in the cooling of clinkers, a flexible cam system according to the present invention can be used to actuate various control mechanisms secured to the body of a rotary furnace or cooler, e.g. burners, valves for the delivery of gaseous agents, electrical switches, etc.
A flexible cam system as hereinbefore particularly described is simple in construction and handling, reliable in operation, and consequently ensures reliable functioning of mechanisms actuated thereby, e.g. burners, valves, etc., which are mounted on rotary furnaces and which provide for efficient operation thereof characterized by a 1.5 to 2 times increase in output and a 10 to 30% reduction in specific fuel consumption.
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A flexible cam system characterized by the use of flexible guide tracks provided with balance weights attached thereto. The guide tracks are connected to a supporting frame through regulating drive mechanisms provided therefor and mounted on opposite sides of the frame. The drive mechanisms are connected respectively with one end of each of said guide tracks rigidly, and with the other end thereof, movably, through guide rollers fixed thereto.
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This application is a continuation of application Ser. No. 08/242,508, filed May 13, 1994, now abandoned.
BACKGROUND OF THE INVENTION
a) Field of the Invention
This invention relates to novel heterocyclic substituted phenoxyalkylpyridines, phenoxyalkylpyridazines and phenoxyalkylpyridimines, to methods of preparation thereof and to methods of use thereof as antipicornaviral agents.
b) Information Disclosure Statement
Published PCT application number WO92/05163 discloses compounds of formula ##STR2## stated to be useful in treating diabetic conditions. Specifically disclosed is N-[2-(4-(2-hydroxy-2-phenyl ethoxy)phenyl)5-oxazolyl]-2,2,2-trifluoro acetamide.
SUMMARY OF THE INVENTION
It has now been found that compounds of Formula I are effective antipicornaviral agents. Accordingly, the present invention relates to a compound of the formula ##STR3## wherein
Q is chosen from the group consisting of pyridyl, pyrazinyl, pyrimidinyl, quinolyl, indolyl and 7-azaindolyl or any of these substituted with one or two substitutents chosen from hydrogen, alkyl, alkoxy, hydroxy, halo, cyano, nitro, hydroxyalkyl, alkoxyalkyl, alkanoyl, fluoroalkyl or the N-oxide of any of the preceding;
Y is an alkylene bridge of 3-9 carbon atoms;
R 1 and R 2 are each independently chosen from hydrogen, halo, alkyl, alkenyl, amino, alkylthio, hydroxy, hydroxyalkyl , alkoxyalkyl , alkylthioalkyl , alkylsulfinylalkyl, alkylsulfonylalkyl, alkoxy, nitro, carboxy, alkoxycarbonyl, dialkylaminoalkyl, alkylaminoalkyl, aminoalkyl, difluoromethyl, trifluoromethyl or cyano;
R 3 is alkoxycarbonyl, alkyltetrazolyl, phenyl or heterocyclyl chosen from benzoxazolyl, benzathiazolyl, thiadiazolyl, imidazolyl, dihydroimidazolyl, oxazolyl, thiazolyl, oxadiazolyl, pyrazolyl, isoxazolyl, isothiazolyl, furyl, triazolyl, tetrazolyl, thiophenyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl or substituted phenyl or substituted heterocyclyl wherein the substitution is with alkyl, alkoxyalkyl, cycloalkyl, haloalkyl, hydroxyalkyl, alkoxy, hydroxy, furyl, phenyl, thienyl or fluoroalkyl;
or the N-oxide thereof;
or a pharmaceutically acceptable acid addition salt thereof.
The invention also relates to compositions for combating picornaviruses comprising an antipicornavirally effective amount of a compound of Formula I with a suitable carrier or diluent, and to methods of combating picornaviruses therewith, including the systemic treatment of picornaviral infections in a mammalian host.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Compounds of Formula I are useful as antipicornaviral agents, and are further described hereinbelow.
Alkyl and alkoxy mean aliphatic radicals, including branched radicals, of from one to five carbon atoms. Thus the alkyl moiety of such radicals include, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, t-butyl, pentyl and the like.
Cycloalkyl means an alicyclic radical having from three to seven carbon atoms as illustrated by cyclopropyl, cyclobutyl, cyclopentyl, cycloheptyl, and cyclohexyl; and
Halo means bromo, chloro, iodo or fluoro.
Heterocyclyl or Het refers to a 5 or 6 membered carbon based heterocycle radical, having from one to about four nitrogen atoms and/or one oxygen or sulfur atom, provided that no two oxygen and/or sulfur atoms are adjacent in the heterocycle. Examples of these include furyl, oxazolyl, isoxazolyl, pyrazyl, imidazolyl, thiazolyl, tetrazolyl, thienyl, pyridyl, oxadiazolyl, thiadiazolyl, triazinyl, pyrimidinyl and the like.
The term heterocyclyl includes all known isomeric radicals of the described heterocycles unless otherwise specified, for example, thiadiazolyl encompasses 1,3,4-thiadiazol-2-yl, 1,2,4-thiadiazol-5-yl, and 1,2,4-thiadiazol-3-yl; thiazolyl encompasses 2-thiazolyl, 4-thiazolylyl and 5-thiazolyl and the other known variations of known heterocyclyl radicals. Thus any isomer of a named heterocycle radical is contemplated. These heterocycle radicals can be attached via any available nitrogen or carbon, for example, tetrazolyl contemplates 5-tetrazolyl or tetrazolyl attached via any available nitrogen of the tetrazolyl ring; furyl encompasses furyl attached via any available carbon, etc. The preparation of such isomers are well known and well within the scope of skilled artisan in medicinal or organic chemistry.
Certain heterocycles can exist as tautomers, and the compounds as described, while not explicity describing each tautomeric form, are meant to embrace each and every tautomer. For example, pyridinones and hydroxy pyridines, are tautomers, thus for convenience in formula I, R 3 is referred to as hydroxy, and it is understood thereby that pyridinones (or tautomers of any analogous heterocycle) are specifically intended.
In the use of the terms hydroxyalkyl and alkoxyalkyl, it is understood that the hydroxy and alkoxy groups can occur at any available position of the alkyl. Thus hydroxyalkyl and alkoxyalkyl include, for example, hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxyisopropyl, 2-, 3-, 4- and 5-hydroxypentyl and the like; alkoxy refers to the corresponding alkyl ethers thereof.
In the use of the term hydroxyalkoxy, it is understood that the hydroxy group can occur at any available position of alkoxy other than the C-1 (geminal) position. Thus hydroxyalkoxy includes, for example, 2-hydroxyethoxy, 2-hydroxypropoxy, 2-hydroxyisopropoxy, 5-hydroxypentoxy and the like.
Alkylene refers to a linear or branched divalent hydrocarbon radical of from 1 to about 5 carbon atoms such as methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,4-(2-methyl)butylene and the like. It can also contain unsaturation, including alkenyl and alkynyl linkages.
Halogen refers to the common halogens fluorine, chlorine, bromine and iodine.
As used herein, the term haloalkyl refers to a halo substituted alkyl, such as fluoroalkyl, chlorofluoroalkyl, bromochloroalkyl, bromofluoroalkyl, bromoalkyl, iodoalkyl, chloroalkyl and the like where the haloalkyl has one or more than one of the same or different halogens substituted for a hydrogen. Examples of haloalkyl include chlorodifluoromethyl, 1-chloroethyl, 2,2,2 trichloroethyl, 1,1 dichloroethyl, 2-chloro, 1,1,1,2 tetrafluoroethyl, bromoethyl and the like.
As used herein the term fluoroalkyl is a prefered subclass of haloalkyl, and refers to fluorinated and perfluorinated alkyl, for example fluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 1,2-difluoroethyl, 1,1,2,3-tetrafluorobutyl and the like.
The compounds of Formula I, are sufficiently basic to form acid addition salts and are useful both in the free base form and the form of acid-addition salts, and both forms are within the purview of the invention. The acid-addition salts are, in some cases, a more convenient form for use, and in practice the use of the salt form inherently amounts to the use of the base form. The acids which can be used to prepare the acid-addition salts include preferably those which produce, when combined with the free base, medicinally acceptable salts, that is, salts whose anions are relatively innocuous to the animal organism in medicinal doses of the salts so that the beneficial properties inherent in the free base are not vitiated by side effects ascribable to the anions. Examples of appropriate acid-addition salts include the hydrochloride, hydrobromide, sulfate, acid sulfate, maleate, citrate, tartrate, methanesulfonate, p-toluenesulfonate, dodecyl sulfate, cyclohexanesulfamate, and the like. However, other appropriate medicinally acceptable salts within the scope of the invention are those derived from other mineral acids and organic acids. The acid-addition salts of the basic compounds can be prepared by dissolving the free base in aqueous alcohol solution containing the appropriate acid and isolating the salt by evaporating the solution, or by reacting the free base and an acid in an organic solvent, in which case the salt separates directly, is precipitated with a second organic solvent, or by concentration of the solution or by any one of several other known methods. Although medicinally acceptable salts of the basic compounds are preferred, all acid-addition salts are within the scope of the present invention. All acid-addition salts are useful as sources of the free base form even if the particular salt per se is desired only as an intermediate product, as, for example, when the salt is formed only for purposes of purification or identification, or when it is used as an intermediate in preparing a medicinally acceptable salt by ion exchange procedures.
The structures of the compounds of the invention were established by the mode of synthesis, by elemental analysis, and by infrared, ultraviolet, nuclear magnetic resonance and mass spectroscopy. The course of the reactions and the identity and homogeneity of the products were assessed by thin layer chromatography (TLC) or gas-liquid chromatography (GLC) or other art recognized means of monitoring organic reactions.
As described herein a noninteracting solvent can be N-methyl pyrrolidine (NMP), methylene chloride (CH 2 Cl 2 ), tetrahydrofuran (THF), benzene or any other solvent that will not take part in the reaction. In a preferred method, the preparation of compounds of the invention is done in dried solvents under an inert atmosphere. Certain reagents used in example preparations are specified by abbreviation: triphenylphosphine (TPP), lithium aluminum hydride (LAH), triethylamine (TEA), diisopropylethylamine (DIPEA), and diethyl azodicarboxylate (DEAD). Ether is diethyl ether unless otherwise specified.
Compounds of Formula I may be prepared by several methods:
Compounds of Formula I can be prepared by the reaction of the appropriate hydroxy-Y-(Q) moiety and the appropriate R 1 -R 2 -R 3 -phenol by the reaction described in U.S. Pat. No. 5,242,924, incorporated herein by reference.
Compounds of Formula I can be prepared by reaction of the appropriate R 1 -R 2 -R 3 -phenol and the appropriate halo-Y-(Q) moiety as described in U.S. Pat. No. 4,942,241, incorporated herein by reference.
Compounds of formula I can be prepared by reacting a X-Y-O-[R 1 -R 2 -R 3 -phenyl] compound (prepared from X-Y-hydroxy or X-Y-halo compounds and R 1 -R 2 -R 3 -phenols by the methods described in U.S. Pat. Nos. 5,242,924 or 4,942,241) with a suitably functionalized Q compound. For example, a hydroxy Q compound, such as hydroxypyridine, can be reacted with halo-Y-O[R 1 -R 2 -R 3 -phenyl] compound to form a compound of formula I. Likewise for example a halo pyridine can be reacted with a hydroxy-Y-O-[R 1 -R 2 -R 3 -phenyl] compound to form a compound of formula I. Examples of known functionalized Q compounds are described in the examples, but any suitably functionalized Q compound, usable in known chemical reactions is contemplated.
Compounds of formula I wherein R 3 is phenyl or heterocyclyl can be preferably prepared by the reaction of a hydroxy-Y-(Q) moiety or halo-Y-(Q) moiety with a R 1 -R 2 -4-functionalized phenol by the methods described in U.S. Pat. Nos. 5,242,924 and 4,942,241, incorporated herein by reference. Then the functional group on the resulting 4-functionalized R 1 -R 2 -phenoxy-Y-Q compound is then substituted by or elaborated into the heterocyclyl or phenyl substituent R 3 as described in U.S. Pat. No. 5,051,437, incorporated herein by reference.
For example, in preparing compounds of formula I wherein R 3 is haloalkyl-substituted oxadiazolyl, or haloalkyl-substituted thiadiazolyl, it is preferred that the corresponding 4 functionalized-R 1 -R 2 -phenoxy-Y-(Q) species be prepared, and the R 3 heterocycle be elaborated in the final steps of the synthesis.
When R 3 is pyrimidyl, phenyl, pyridyl, furyl, thienyl, benzofuranyl and the like it is preferred that the heterocycle be attached to the phenyl moiety by standard coupling methods. For example, when R 3 is pyridyl, a pyr-Y-O-R 1 -R 2 -phenyl borate can be reacted with a halo pyridine, such as bromopyridine to afford the corresponding compound of formula I wherein R 3 is pyridyl.
This method is also applicable to preparing R 1 -R 2 -R 3 -phenols, useful in the method described above for preparing compounds of formula I, but where Q-Y- is replaced by a suitable protecting group, which is cleaved to liberate the R 1 -R 2 -R 3 -phenol.
The skilled practitioner will recognize that certain R 3 , especially heterocycles with 2 or more hetero atoms such as oxazolyl, oxadiazolyl, tetrazolyl, triazolyl and the like, are more easily prepared by elaborating a functional group, such as cyano, acyl, amino and the like, at the 4-position of the phenyl ring; thus forming the heterocycle "in situ" rather than attaching it in the R 3 position.
For example, the compound of Formula I can also be prepared from an appropriate 4-functionalized phenoxy -Y-(Q) species (abbreviated ZO-R 1 -R 2 -4-functionalized phenyl wherein Z is Q-Y), wherein the 4-phenoxy position is substituted with the desired heterocycle precursor. For example, Q-Y-O-R 1 -R 2 -benzaldehydes, and 4-[Q-Y-O-R 1 -R 2 -benzonitriles are known in the art (cf. for example, Mamose et al., Chem. Pharm. Bull. 39 1440-1445) or can be prepared from known materials, using methods well known in the art. In a preferred method, especially where R 3 is a substituted heterocycle two or more heteroatoms, it is preferred that the R 3 heterocycle is elaborated as a last step in the synthesis of the compound of formula I, as described in allowed U.S. patent application Ser. No. 07/869,287, incorporated hereby by reference. Suitable functional groups for the 4-phenoxy position will depend upon the heterocycle sought in the final product. For example, where Het is 1,2,4-oxadiazolyl ##STR4## compounds are prepared from either the appropriate 4-Z-O-R 1 -R 2 -benzonitrile by reaction with hydroxylamine hydrochloride in a noninteracting solvent, preferably an alkanol, for example, methanol, ethanol, n-butanol and the like, in the presence of a base, such as potassium carbonate or pyridine, or in a preferred method, an alkali metal salt of a carboxylic acid such as sodium trifluoroacetate or sodium acetate, at a temperature between ambient temperature and the boiling point of the solvent. The product thus obtained is then reacted with an acid anhydride of formula (R'CO) 2 O, (where R' is alkyl, haloalkyl); R appears as a substituent on the R 3 heterocycle of the product. When R' is haloalkyl it is preferred that this reaction be the final synthetic step. Thus, the product is a compound of formula I, where the starting material is 4-ZO-R 1 -R 2 -benzonitrile and Z is Q-Y.
It will be understood that when Z represents a protecting group, the method will produce a protected phenol, which is deprotected to form an R 1 -R 2 -R 3 -phenol. This phenol is then useful in preparing the compound of formula I when reacted with the appropriate hydroxy-Y-(Q) or halo-Y-(Q) as described above.
It will be appreciated that neither the timing of the elaboration of the heterocyclic substituents nor the order of assembly of the intermediates is crucial to the successful synthesis of compounds of Formula I. Thus by judicious choice of reactants one can prepare any of the compounds of Formula I, by several different routes.
The R 1 -R 2 -R 3 -phenols (wherein R 3 is heterocyclyl) used to prepare compounds of Formula I are known in the art or prepared by known methods. For most phenols, their preparation is described in U.S. Pat. Nos. 4,942,241; 4,945,164; 5,051,437; 5,002,960; 5,110,821; 4,939,267; 4,861,971; 4,857,539; 5,242,924; or 4,843,087 incorporated herein by reference. In addition, other known phenols including, for example, 4-phenyl-R 1 -R 2 -phenols and 4-alkoxycarbonyl-R 1 -R 2 -phenols, are well known and can be used in preparing compounds of formula I. It is expected that any R 1 -R 2 -R 3 -4-phenol disclosed in these patents, described elsewhere in the art, or prepared by methods known in the art are useful in preparing compounds of formula I.
R 1 -R 2 -R 3 -phenols, (R 3 =heterocycle) can be prepared from the suitably protected phenol which has been functionalized at the 4-position by a functional group such as cyanide, aldehyde, halide, acid chloride group or other suitable reactive group, by preparing the heterocycle "in situ" as described above or as described in U.S. Pat. Nos. 4,942,241; 4,945,164; 5,051,437; 5,002,960; 5,110,821; 4,939,267; 4,861,971; 4,857,539; 5,242,924; or 4,843,087 each incorporated herein by reference, or methods known in the literature. The heterocycle is elaborated from the functional group and the phenol is deprotected by means well known in the art. Alternatively, R 1 -R 2 -R 3 -phenols may be prepared by displacing a functional group, e.g. halo, with the R 3 substituent as described above.
Hydroxy-Y-Q compounds can be prepared from known pyridine, pyrimidine or pyrazine halides, alcohols, acids or carboxyalkyl compounds or from any other known pyridines, pyrimidines or pyrazines that can be suitably functionalized by known methods. For a review of reaction methods, see Katritsky and Rees, Comprehensive Heterocyclic Chemistry volume 2 and 3 (Pergamon, 1984), especially sections 2.13-2.14.
For example, pyridinyl triflate can be reacted with a X-Y-Z compound where Z is a functional group, wherein Y has a terminal alkenyl or alkynyl linkage and X is a tin species such as tributyl tin. Other useful Y-Z species include terminally unsaturated acids, esters or alcohols, such as alkynyl alkanols, α,β-unsaturated esters and the like. It is preferred that alkanols and acids be suitably protected. After reaction the resulting unsaturated alkanols, esters and acids are reduced to alkanols and any unsaturation in the alkyl backbone may be partially or completely reduced by known methods. Such reduction methods include, but are not limited to palladium or carbon, lithium aluminum hydride or other hydride reduction. Alternatively, such alkanols may be prepared by reaction of pyridyl ketones, aldehydes and the like, for example under Wittig conditions, to yield the corresponding unsaturated esters and the like which can be reduced as described above. The hydroxy-Y-(Q) can be prepared from the known pyridyl, pyrimidyl or pyrazyl triflate or halide and an unsaturated species by palladium coupling, (such as the Heck reaction) which is well known in the art. Halo-Y(Q) compounds are prepared by analagous, known methods.
Simple chemical transformations which are conventional and well known to those skilled in the art of chemistry can be used for effecting changes in functional groups in the compounds of the invention. For example, acylation of hydroxy- or amino-substituted species to prepare the corresponding esters or amides, respectively; alkylation of phenyl or other aromatic and heterocyclic substituents; cleavage of alkyl or benzyl ethers to produce the corresponding alcohols or phenols; and hydrolysis of esters or amides to produce the corresponding acids, alcohols or amines, preparation of anhydrides, acid halides, aldehydes, simple aromatic alkylation and the like as desired can be carried out.
Moreover, it will be appreciated that obtaining the desired product by some reactions will be better facilitated by blocking or rendering certain functional groups nonreactive. This practice is well recognized in the art, see for example, Theodora Greene, Protective Groups in Organic Synthesis (1991). Thus when reaction conditions are such that they can cause undesired reactions with other parts of the molecule, the skilled artisan will appreciate the need to protect these reactive regions of the molecule and act accordingly.
Starting materials used to prepare the compounds of Formula I are commercially available, known in the art, or prepared by known methods.
EXEMPLARY DISCLOSURE
For the purpose of naming substituents in Formula I, the phenyl ring of any compound of formula I shall be numbered; ##STR5##
Thus when a compound of formula I has substitution on the phenyl ring, it is referred to by this numbering system regardless of how the compound is actually named. For example, if a compound is prepared and the designation R 1 ,R 2 =3,5-dimethyl, this means ##STR6## regardless of whether 3,5-dimethyl or 2,6-dimethyl appears the name of the compound.
PREPARATION OF INTERMEDIATES
Intermediate 1
A. Ethyl β-(6-methylpyridin-3-yl)acrylate
A suspension of 4.8 g of 6-methyl-3-pyridine-triflate, 2.5 g of LiCl, 4.3 ml of ethyl acrylate, and 0.32 g of PdCl 2 (P(Ph) 3 ) 2 in 7.8 ml of triethylamine and 9.6 ml of dry DMF was heated at 100° C. under nitrogen for 36 h. The desired product was purified by flash chromatography on silica gel to afford 3.14 g (63%) of ethyl β-(6-methylpyridin-3-yl)acrylate, as a pale yellow-orange oil,
B. Ethyl 3-(6-methylpyridin-3-yl)propionate
A suspension of ethyl β-(6-methylpyridin-3-yl)acrylate (3.86 g, 20.2 mmol) in 200 ml of ethyl acetate and 1.4 g of 5.3% Pd/C was hydrogenated under hydrogen (50 psi) for 4 h. The mixture was filtered through SUPERCEL™, the filtrate was concentrated in vacuo to afford 3.75 g (96%) of ethyl 3-(6-methylpyridin-3-yl)propionate, as a pale orange oil.
C. 6-Methyl-3-(3-hydroxypropyl)pyridine
To a suspension of 0.75 g (1 equiv) of LAH in 50 ml of THF at 0° C. under nitrogen was added 3.75 g (19.4 mmol) of ethyl 3-(6-methylpyridin-3-yl)-propionate in 10 ml of THF. The reaction mixture was quenched, filtered, and the filtrate was concentrated in vacuo to yield 3.0 g of the product as a viscous red oil. The oil was filtered through florosil eluting with ethyl acetate and concentrated in vacuo to afford 2.5 g (86%) of 6-methyl-3-(3-hydroxypropyl)-pyridine as an orange oil.
Intermediate 2
a) 5.2 g (27 mmol) of 3-bromo-6-chloropyridine, 5.9 ml (Cl-Pyr-2 equivalents) of ethyl acrylate, 12.5 ml (2 equivalents) of tributyl amine and 0.176 g of palladium bis acetate were taken up in 10 ml DMF and heated to 100° C. for 24 hours. The reaction mixture was extracted with dilute HCl and then base. The organic fraction was then dried over magnesium sulfate, filtered and concentrated in vacuo to an oil, which was applied to silica gel and eluted with 0 3: 1 hexane/ethyl acetate, the product was recrystallized from hexane to give 2.3 g of pure product. Remaining residue was purified by chromatography and recrystallized from hexane to give an additional 2.0 g of product (68%) of the desired product.
b) A suspension of 0.84 g of Te powder, 0.60 g of NaBH 4 and 32 ml ethanol was heated under nitrogen until the reaction mixture became purple. To this solution was added 1.38 g of the product from 11a and the mixture was refluxed for 4 hours and upon cooling quenched with water. The reaction mixture was extracted with water and the organic fraction was then dried over magnesium sulfate, filtered and concentrated in vacuo to an oil, which was applied to silica gel and eluted with 3:1 hexane/ethyl acetate giving 1.11 g of product that was used in the next synthetic step without purification.
c) To a suspension of 0.2 g of lithium aluminum hydride in 25 ml of dry THF at 0° C was added the solution of 1.11 g of the product of preparation 2b (above) in 5 ml THF. The reaction was maintained at 3°-5° C. for 4 hours and then quenched with water and 10% NaOH, and filtered through celite while washing with ether. The organic fraction was concentrated in vacuo to afford 0.87 g of the 3 (6-chloro-3-pyridyl)propanol product as an oil, used without further purification.
Intermediate 3
a) A suspension of 5.0 g of 2-methyl-5-triflylpyridine, 2.62 g of lithium chloride 4.5 ml of ethyl acrylate and 8.2 ml of triethyl amine and 0.345 g of dichlorotdi(triphenyl)phosphinepalladium (Pd(pH 3 ) 2 Cl 2 ) in 10 ml dry DMF was heated to 100° C. for 36 hours. The suspension was then diluted with ethyl acetate and poured into water. The organic phase was washed thrice with water and dried over potassium carbonate. Concentration and flash chromatography on kieselgel with 3:2 hexane ethyl acetate provided 3.2 g (80%) of the desired product used without further purification.
b) A suspension of 3.2 g of the product of preparation 12a and 1.0 g of 53% palladium on carbon in 200 ml ethyl acetate was subjected to 50 psi hydrogen. Filtration and concentration yielded 3.1 g (97%) of the desired product as an orange oil, used in the next step without further purification.
c) A suspension of 0.62 g of lithium aluminum hydride on 50 ml of dry THF was cooled to 0° C. under nitrogen. To this suspension 3.1 g of the ester of preparation 3b (above) in 10 ml THF was added and stirred for an hour. The reaction was quenched with water and NaOH. The product was filtered through celite, and residue washed through with ethyl acetate. The product was dried, concentrated in vacuo, yeilding 2.4 g of the 3-(3-methyl)pyridyl)propanol.
Intermediate 4
Using any known or commercially available halide, of which the following are examples (while others are contemplated);
a) 4 pyridyl chloride
b) 2-methyl-4-pyridyl chloride
c) 5-methyl-2-pyridyl bromide
d) 4-methyl-2-pyridyl chloride
e) 2-pyridazyl chloride
f) 2-bromo-6-methyl pyrimidine
g) 2-bromo-5-methyl pyrimidine
and ethyl acrylate one can prepare intermediates the following intermediate 3-(Pyr)propanols using the methods of Intermediate 2.
a) 3-(4-pyridyl)propanol
b) 3-(2-methyl-4-pyridyl)propanol
c) 3-(5-methyl-2-pyridyl)propanol
d) 3-(4-methyl-2-pyrimidyl)propanol
e) 3-(2-pyridazyl)propanol
f) 3-(6-methyl-2-pyridyl)propanol
g) 3-(5-methyl-2-pyrimidyl)propanol
Any of the above alkanols can be reacted with any of the phenols of Example 19, Intermediate 5, and the like using the method of Example 1E to afford compounds of formula I.
Intermediate 5
1.68 g (10 mmol) 3-fluoro-4-methoxyacetophenone and 4.88 g (11 mmol) lead tetraacetate were dissolved in 10 mL benzene and refluxed. Ethylene glycol was used to quench the reaction. On standing, the resulting 3.19 g of yellow oil crystallized. 1.44 g (6.37 mmol) of the crystals and 2.31 g (30 mmol) of ammonium acetate were combined in 15 mL glacial acetic acid and refluxed 4 hours. The product was poured into water, then basified. The aqueous layer was extracted twice with methylene chloride then concentrated to dryness and recrystallized from methylene chloride yielding 0.8 g of product, 0.59 g (2.85 mmol) of which was taken up in 25 mL methylene chloride and combined with 2 mL of a 1M solution of boron tribromide in methylene chloride and refluxed for 30 minutes. The product was poured into water and basified. The aqueous layer was washed twice with methylene chloride. The organic layers were combined and washed with water, 1N HCl, and brine and evaporated to dryness. The product was recrystallized from methanol giving 0.09 g of 4-(2-fluoro-4-hydroxyphenyl)-2-methyl-4-oxazole.
EXAMPLE 1
A. 2-Fluoro-5-bromopyridine
A suspension of 2.2 g (15.6 mmol) of 2-fluoro-5-pyridine-carboxylic acid, 5.1 g of HgO (red) and 1.2 ml of bromine in 100 ml of CCl 4 was irradiated (by) under reflux for 5 h, cooled to room temperature, filtered through celite, and the filtrate was concentrated in vacuo. The residue was dissolved in hexane, filtered, and the filtrate was concentrated in vacuo to afford 1.73 g (63%) of 2-fluoro-5-bromopyridine, as a pale yellow oil.
B. 2-Fluoro-5-[3-(t-butyl-dimethylsilyloxy)-2-propynyl]pyridine
A suspension of 1.45 g (8.2 mmol) of 2-fluoro-5-bromopyridine, 4.2 g (1.1 eq) of 1-tributyltin-3-t-butyl-dimethylsilyloxy-2-propyne and 0.11 g (3 mol %) of PdCl 2 (P(Ph) 3 ) 2 in 5 ml of dry THF was refluxed under nitrogen for 24 h. The mixture was concentrated in vacuo and the residue was purified by flash filtration (silica gel; hexane/ethyl acetate, 3:1) and MPLC (26 id, silica gel 60, hexane/ethytl acetate, 5:1) to afford 2.3 g (2.2 g-theory) of 2-fluoro-5-[3-(t-butyl-dimethylsilyloxy)-2-propynyl]pyridine, as a dark red oil (crude).
C. 2-Fluoro-5-(3-t-butyl-dimethylsilyloxy)propyl-pyridine
A suspension of 1.5 g (5.7 mmol) of 2-fluoro-5-[3-(t-butyl-dimethylsilyloxy)-2-propynyl]pyridine and 0.58 g of 5% Pd/C in 200 ml of ethyl acetate was hydrogenated at 50 psi (H 2 ) for 2 h. The mixture was filtered and the filtrate was concentrated in vacuo to yield 2.1 g of a red oil (crude). The red oil was purified by MPLC (26 id, Kieselgel 60, hexane/ethyl acetate, 6:1) to afford 0.78 g (52%) of 2-fluoro-5-(3-t-butyl-dimethylsilyloxy)propyl-pyridine, as a light red oil.
D. 2-Fluoro-5-(3-hydroxy)propyl-pyridine
To a suspension of 0.78 g (2.9 mmol) of 2-fluoro-5-(3-t-butyldimethylsilyloxy)-propyl-pyridine in 10 ml of dry THF was added 3.8 ml (1.3 eq) of 1M TBAF solution in THF. The dark brown solution was stirred under nitrogen at room temperature for 2 h, poured into water and extracted with ether. The organic layer was washed with water, dried over sodium sulfate, filtered, and the filtrate was concentrated in vacuo to afford 0.26 g (57.8%) of 2-fluoro-5-(3-hydroxy)-propylpyridine, as a brown oil.
E. 2-Fluoro-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-fluoro-3-pyridyl, Y=1,3-propylene, R 1 , R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 0.31 g (1.2 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2, 6-dimethylphenol, 0.26 g (1.4 eq) of 2-fluoro-5-(3-hydroxypropyl)-pyridine, 0.45 g (1.4 eq) of triphenylphosphine in 40 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 0.28 g (1.4 eq) of DEAD in 2 ml of methylene chloride. The dark brown solution was stirred at room temperature for 24 h, concentrated in vacuo and the residue was purifed by MPLC (26 id Kieselgel 60 column; hexane/ethyl acetate 5:1) to yield 5.5 g of the product. Recrystallizations from t-butylmethylether/hexane as well as hexane (2nd recrystallization) afforded 0.23 g (48.9%) of 2-fluoro-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a white solid. The above product was repurified by preparative tlc (hexane/ethyl acetate/triethylamine, 5:1:0.5) to yield 0.22 g (46.8%) of a white solid.
EXAMPLE 2
A. 2-Chloro-5-bromopyridine
A suspension of 2 g (12 mmol) of 2-chloro-5-pyridine-carboxylic acid, 4.12 g (19 mmol) of HgO (red) and 1 ml (19 mmol) of bromine in CCl 4 was irradiated (flood lamp) under reflux for 2.5 h. The mixture was cooled to room temperature, 30 ml of sat. sodium bicarbonate solution was added, and the mixture was stirred vigorously for 15 min. The biphasic orange suspension was filtered through celite, the organic layer was washed with brine and dried over sodium sulfate. The filtrate was concentrated in vacuo to afford 1.1 g (45.8%) of 2-chloro-5-bromopyridine, as a white solid, m.p. 67°-69° C.
B. Ethyl β-(2-chloropyridin-5-yl)acrylate
A suspension of 0.5 g (2.6 mmol) of 2-chloro-5-bromopyridine, 1.2 ml (2 eq) of tri-n-butylamine, 0.56 ml (2 eq) of ethyl acrylate, and 17 mg (3 mol %) of Pd(OAc) 2 in 1 ml of dry DMF was heated at 80°-90° C. under nitrogen for 40 h. The mixture was poured into ether, washed with sat. ammonium chloride solution followed by water. The organic layer was dried over potassium carbonate and concentrated in vacuo to yield 1 g of a dark solid which was purified by preparative tlc (2000 micron silica gel -2 plates, hexane/ethyl acetate, 2:1) to afford 0.26 g (47.3%) of ethyl b-(2-chloropyridin-5-yl)acrylate, as a solid.
C. Ethyl 3-(2-chloropyridin-5-yl)propionate
A suspension of 0.84 g (1 eq) of Te powder and 0.6 g (2 eq) of NaBH 4 in 32 ml of ethanol was heated under nitrogen until it became a homogeneous purple solution. To the above hot solution was added ethyl β-(2-chloropyridin-5yl)acrylate (1.38 g, 6.5 mmol) and the mixture was refluxed for 4 h. The crude product was purified by flash chromatography (silica gel; hexane/ethyl acetate, 3:1) to afford 1.11 g (84,6%) of ethyl 3-(2-chloropyridin-5-yl)propionate.
D. 2-Chloro-5-(3-hydroxypropyl)pyridine
To a suspension of 0.2 g of LAH in 25 ml of dry THF at 0° C. under nitrogen was added a solution of 1.11 g (5.2 mmol) of ethyl 3-(2-chloropyridin-5-yl)-propionate in 5 ml of THF. The reaction mixture was kept at 3° C.-5° C. for 1 h and quenched with 0.2 ml of water, 0.2 ml of 10% NaOH, and 0.6 ml of water successively. The mixture was filtered through celite (washing with ether) and the filtrate was concentrated in vacuo to yield 0.87 g (theory) of 2-chloro-5-(3-hydroxypropyl)-pyridine as a yellow viscous oil (crude).
E. 2-Chloro-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-chloro-3-pyridyl, Y=1,3-propylene, R 1 , R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 1.12 g (4.34 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.87 g (1.2 eq) of 2-chloro-5-(3-hydroxypropyl)-pyridine, 1.4 g (1.2 eq) of triphenylphosphine in 50 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 0.86 g (1.2 eq) of DEAD in 5 ml of methylene chloride. The mixture was stirred under nitrogen at room temperature for 60 h, concentrated in vacuo and the residue was triturated with hexane/ethyl acetate, filtered, and the filtrate was concentrated in vacuo to yield a dark brown oil. The brown oil was purified by MPLC (50 id, Kieselgel 60 column, hexane/ethyl acetate, 3:1) to afford 1.4 g (78%) of 2-chloro-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a white crystalline solid, m.p. 89°-91° C.
EXAMPLE 3
A. 2-Methoxypyridine-5-carboxaldehyde
To a solution of 4.8 g (25.5 mmol) of 2-methoxy-5-bromopyridine in ether cooled to 0° C. was added 16.6 ml (1.1 eq) of t-butyllithium in pentane. The above reaction mixture was cooled to -78° C., 2.2 ml of DMF in ether was added and the resulting mixture was stirred at -78° C. and then allowed to warm to room temperature. The mixture was quenched with sat. aqueous ammonium chloride and diluted with water. The organic layer was separated, washed with water, dried over sodium sulfane, and concentrated in vacuo to yield 3.6 g of a yellow crude oil which was further purified by flash chromatography (silica gel 60, hexane/ethyl acetate, 3:1) to afford 2.54 g (71.2%) of 2-methoxypyridine-5-carboxaldehyde, as a pale yellow oil which solidified upon standing.
B. Methyl β-(2-methoxypyridin-5-yl)acrylate
A suspension of 0.65 g (1.1 eq) of 95% NaH in 22 ml of toluene was slowly added to 3.8 g (1 eq) of methyl diethylphosphonoacetate in 5 ml of dry toluene below 35° C. The clear yellow solution was allowed to stir under nitrogen at room temperature for 30 min and a solution of 2.5 g (18.2 mmol) of 2-methoxy-pyridine-5-carboxaldehyde in 10 ml of toluene was added dropwise while maintaining the reaction temperature below 40° C. After the addition, the mixture was heated at 65° C. for 30 min, cooled, and filtered through solka floc and concentrated in vacuo to yield 3 g (85.7%) of methyl β-(2-methoxypyridin-5-yl)acrylate (cis/trans mixture).
C. Methyl 3-(2-methoxypyridin-5-yl)propionate
A suspension of methyl β-(6-methoxypyridin-3-yl)acrylate (3 g, 15.5 mmol) and 1 g of 5% Pd/C in 100 ml of ethyl acetate was hydrogenated under hydrogen (50 psi). After hydrogen uptake had ceased, the mixture was filtered through solka floc, the filtrate was concentrated in vacuo to afford 2.7 g (90%) of methyl 3-(6-methoxypyridin-5-yl)propionate.
D. 2-Methoxy-5-(3-hydroxypropyl)pyridine
To a suspension of 0.56 g (1.1 eq) of LAH in 50 ml of dry THF at 5° C. under nitrogen was added a solution of 2.7 g (13.5 mmol) of methyl 3-(2-methoxy-pyridin-5-yl)-propionate in THF and the reaction mixture was stirred at room temperature for 2 h. The mixture was quenched with 0.6 ml of water, 0.6 ml of 10% NaOH, and 1.8 ml of water successively. The mixture was filtered and the filtrate was concentrated in vacuo to yield 2.0 g (87%) of 2-methoxy-5-(3-hydroxypropyl)-pyridine as a yellow oil.
E. 2-Methoxy-5-[3-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-methoxy-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-methyl-1,2,4-oxadiazol-3-yl)
To a suspension of 0.81 g (3.9 mmol) of 4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.8 g (1.2 eq) of 2-methoxy-5-(3-hydroxypropyl)-pyridine, 1.4 g (1.2 eq) of triphenylphosphine in 70 ml of methylene chloride under nitrogen at 5° C. was added in portions 0.88 g (1.2 eq) of DEAD. The mixture was concentrated in vacuo, the residue was triturated with ether, filtered, and the crude product was purified by MPLC (50 id,Kieselgel 60 column, hexane/ethyl acetate, 2:1) and recrystallization from isopropyl acetate/hexane to afford 1 g (71.4%) of 2-methoxy-5-[3-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a white powder, m.p. 71°-73° C.
F. 2-Methoxy-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-methoxy-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 1.54 g (6 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 1.2 g (1.2 eq) of 2-methoxy-5-(3-hydroxypropyl)-pyridine, 1.9 g (1.2 eq) of triphenylphosphine in 50 ml of methylene chloride under nitrogen at 5° C. was added in portions 1.22 g (1.2 eq) of DEAD. The mixture was stirred at room temperature for 20 h, concentrated in vacuo, the residue was triturated with ether, and filtered. The crude product was purified by MPLC (50 id, Kreselgel 60 column, hexane/ethyl acetate, 3:1) to afford 2 g (82%) of 2-methoxy-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a clear oil, which upon recrystallization from isopropyl acetate/hexane afforded white powder, m.p. 62°-64° C.
G. 5-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-2(1H)-pyridone (I, Pyr=6-hydroxy-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
A solution of 3.0 g (7.36 mmol) of 2-methoxy-5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine and 3.6 ml (3.4 eq) of trimethylsilyl iodide in 60 ml of 1,2-dichloroethane was refluxed under nitrogen for 1 h. The above red solution was quenched with methanol, poured into water, and diluted with methylene chloride. The organic layer was washed with sodium bisulfite, dried over magnesium sulfate, and concentrated in vacuo. The residue was recrystallized from isopropyl acetate to afford 1 g (34.5%) of 5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-2(1H)-pyridone, as a white, flaky solid, m.p. 128.5°-130.5° C.
H. 5-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl) -2,6-dimethylphenoxy]-propyl]-1-methyl-2-pyridone (I, Q=1-methyl-2-pyridone, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 0.95 g (2.41 mmol) of 5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-2(1H)-pyridone, 20 drops of TDA-1, and 0.5 ml of methyl iodide in 50 ml of dry DMF was added 0.96 g (3 eq) of milled K 2 CO 3 . The mixture was filtered and concentrated in vacuo to afford 0.9 g (91.8%) of 5-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-1-methyl-2-pyridone, as a white solid, which was recrystallized from isopropyl acetate to yield a white solid, 143°-146° C.
EXAMPLE 4
A. 2-Acetyl-6-(3-hydroxy-2-propynyl)pyridine
A suspension of 3 g (15.1 mmol) of 2-acetyl-6-bromopyridine, 0.89 g (15.9 mmol) of propargyl alcohol, 0.078 g of CuI, 300 mg of PdCl 2 (P(Ph) 3 ) 2 in 60 ml of triethylamine was stirred under nitrogen at room temperature for 6 h. The mixture was diluted with water, extracted with ether, and the organic layer was washed with water (2x), brine, and dried over magnesium sulfate. The organic solution was concentrated in vacuo and the residue was purified by MPLC (silica gel 60, hexane/ethyl acetate, 1:1) to afford 1.3 g (50%) of 2-acetyl-6-(3-hydroxy-2-propynyl)pyridine, as a solid product.
B. 2-Acetyl-6-(3-hydroxypropyl)-pyridine
A suspension of 1.3 g of 2-acetyl-6-(3-hydroxy-2-propynyl)pyridine and 0.5 g of 10% Pd/C in 50 ml of ethyl acetate was hydrogenated at 50 psi (H 2 ) overnight. The mixture was filtered and the filtrate was concentrated in vacuo to yield 1.1 g (84.6%) of 2-acetyl-6-(3-hydroxypropyl)-pyridine, as a yellow oil (crude).
C. 2-Acetyl-6-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=2-acetyl-2-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 0.1 g (0.55 mmol) of 2-acetyl-6-(3-hydroxypropyl)-pyridine, 0.14 g of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.175 g (1.2 eq) of triphenylphosphine in DMF under nitrogen at 0° C. was added dropwise a solution of 0.097 g (1.2 eq) of DEAD in DMF. The bright red solution was stirred at room temperature overnight, diluted with water, and extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, concentrated in vacuo, and the residue was purifed by MPLC to afford 2-acetyl-6-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine.
EXAMPLE 5
A. 3-[4-(t-Butyl-dimethylsilyloxy)-2-butynyl]pyridine
A suspension of 2 g (12.6 mmol) of 3-bromopyridine, 8.4 g (17.8 mmol) of 1-tributyltin-4-t-butyl-dimethylsilyloxy-2-butyne and 40 mg of PdCl 2 (P(Ph) 3 ) 2 in 5 ml of dry THF was refluxed under nitrogen . After adding additional 1-tributyltin-4-t-butyl-dimethylsilyloxy-2-butyne, the mixture was refluxed ovenight. The mixture was concentrated in vacuo and the residue was purified by flash filtration (2x; silica gel; hexane/ethyl acetate, 1/0, and 3:1) to afford 2.2 g (66.6%) of 3-[4-(t-butyl-dimethylsilyloxy)-2-butynyl]pyridine, as an amber oil.
B. 3-(4-t-Butyl-dimethylsilyloxy)butyl-pyridine
A suspension of 2.2 g (8.43 mmol) of 3-[4-(t-butyl-dimethylsilyloxy)-2-butynyl]pyrine and 2 g of 10% Pd/C in 50 ml of ethyl acetate was hydrogenated at 20 psi (H 2 ) for 2 h. The mixture was filtered through SUPERCEL™ and the filtrate was concentrated in vacuo to yield 2.1 g (52%) of 3-(4-t-butyl-dimethylsilyloxy)butyl-pyridine, as a solid product.
C. 3-(4-Hydroxy)butylpyridine
A solution of 2.13 g (7.6 mmol) of 3-(4-t-butyldimethylsilyloxy)butyl-pyridine in 50 ml of dry THF was added to 8.4 ml (2.2 eq) of 1M TBAF solution in THF. The solution was stirred under nitrogen at room temperature overnight. The mixture was diluted with water, extracted with ether, and the organic layer was washed with water, and dried over potassium carbonate. The organic layer was filtered, and the filtrate was concentrated in vacuo to afford 1.26 g of a yellow oil. The oil was dried in vacuo overnight to afford 0.25 g (21.7%) of 3-(4-hydroxy)-butylpyridine, as a yellow oil.
D. 3-[4-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-butyl]-pyridine (I, Q=3-pyridyl, Y=1,4-butylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 0.44 g (1.8 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.25 g (1.66 mmol) of 3-(4-hydroxybutyl)-pyridine, and 0.52 g (1.99 mmol) of triphenylphosphine in 30 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 0.35 g (1.97 mmol of DEAD in methylene chloride, and the resulting mixture was allowed to warm to room temperature. After adding 70 mg of triphenylphosphine, the mixture was stirred at room temperature for 2 days. The solution was concentrated in vacuo and the residue was purifed by MPLC (26 id Kieselgel 60 column; hexane/ethyl acetate 3:1) to yield 0.56 g (86.1%) of 3-[4-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-butyl]-pyridine, as a pale yellow oil.
EXAMPLE 6
A. 3-(3-Hydroxypropyl)pyridine
3-Bromopyridine and ethyl acrylate were reacted as in example 1A giving the corresponding (3-pyridyl) α,β-unsaturated propionic ethyl ester which was then reduced with palladium on carbon with hydrogen and with lithium aluminum hydride to produce the corresponding 3-(3-pyridyl)-propanol.
B. 3-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=3-pyridyl, R 1 , R 2 =3,5-dimethyl, Y is 1,3-propylene, Het 2 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
The propanol from Example 7A was reacted with the phenol of Example 1D using triphenylphosphine and DEAD as in Example 1D to form a compound of formula I.
C. 3-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine-N-oxide (I, Q=3-pyridyl-N-oxide, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (1 g, 2.6 mmol) in 50 ml of methylene chloride cooled to 0° C. was added 0.67 g (3.9 mmol) of m-chloroperoxybenzoic acid, and the mixture was allowed to stir overnight. The mixture was washed with saturated sodium bicarbonate, the organic layer was dried over magnesium sulfate and concentrated in vacuo to afford 1 g (98%) of 3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine-N-oxide, as a yellow oil which crystallized (yellow flakes) on standing, m.p. 84°-86°C.
D. 1-Methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridinium methanesulfonate (I, Pyr=1-methyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (1 g, 2.6 mmol, 1.1 eq) in 10 ml of methylene chloride was added methyl methanesulfonate (0.32 g, 2.9 mmol) and the mixture was gently refluxed overnight. After adding 0.5 eq of methyl methanesulfonate, the mixture was allowed to reflux an additional 24 h. The mixture was concentrated in vacuo and a solid residue was washed with ether to afford 1.11 g (85.3%) of 1-methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridinium methanesulfonate, as a white powder.
EXAMPLE 7
A. Ethyl β-(2-methylpyridin-3-yl)acrylate
A solution of 0.55 g (4.54 mmol) of 2-methylpyridine-5-carboxaldehyde in toluene was added dropwise into a cool suspension of 1.12 g (5 mmol) of ethyl diethylphosphonoacetate and 0.12 g (5 mmol) of NaH in toluene and the resulting solution was allowed to react at 65° C. for 30 min. After cooling, the mixture was filtered through SUPERCEL™ (wash SUPERCEL™ with ether) and concentrated in vacuo to yield 0.71 g (87.6%) of ethyl β-(2-methylpyridin-3-yl)acrylate (cis/trans mixture), which was further purified through a silica plug (hexane/ethyl acetate, 1:1).
B. Ethyl 3-(2-methylpyridin-3-yl)propionate
The compound from Example 8A was reduced with palladium on carbon and hydrogen to the corresponding ethyl ester according to the method of Example 1B.
C. 2-Methyl-3-(3-hydroxypropyl)pyridine
The α,β unsaturated ethyl ester from Example 8B was reduced using lithium aluminum hydride to the corresponding propanol using the method of Example 1C.
D. 3-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-2-methylpyridine (I, Q=2-methyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
Propanol from Example 8C was reacted with the appropriate phenyl according to the method of example 1D to give a compound of Formula I.
EXAMPLE 8
A. 3-(3-Pyridyl)-propanol
The 3-(3-pyridyl)-propanol was prepared according to the method of Example 4A-D.
B. 3-[3-(2,6-dimethyl-4-cyanophenoxy)-propyl]-pyridine
The propanol from 9A was then reacted with 4-cyano-2,6-dimethyl-phenol according to the method of Example 1D.
C. 3-[3-(2,6-Dimethyl-4-aminohydroximinomethyl-phenoxy)-propyl]-pyridine
To a solution of 3.4 g (13 mmol) of 3-[3-(2,6-dimethyl-4-cyanophenoxy)-propyl]-pyridine with a small amount of dihydro-DEAD in 100 ml of ethanol was added at room temperature potassium carbonate (4.44 g; 64 mmol) and 8.21 g (64 mmol) of hydroxylamine hydrochloride, and the mixture was refluxed with stirring. The reaction mixture was cooled, filtered, the filtrate concentrated in vacuo to afford 3.9 g (theory) of 3-[3-(2,6-dimethyl-4-aminohydroximino-methylphenoxy)propyl]-pyridine.
D. 3-[3-[2,6-Dimethyl-4-(5-difluoromethyl-1,2,4-oxadiazol-2-yl-phenoxy)]-propyl]-pyridine (I, Q=3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-difluoromethyl-1,2,4-oxadiazol-3-yl)
A mixture of 3.9 g (13 mmol) of 2-[3-(2,6-dimethyl-4-aminohydroximino-methylphenoxy)propyl]-pyridine and 13 ml of ethyl difluoroacetate was refluxed for 2.5 h. The above reaction mixture was cooled, filtered, and the filtrate was concentrated in vacuo to yield 5 g of a crude residue. The residue was purified by silica gel chromatography (ethyl acetate/hexane, 2:1) and MPLC eluting with ethyl acetate/hexane (7:1) to afford 0.7 g (14.9%) of 3-[3-[2,6-dimethyl-4-(5-difluoromethyl-1,2,4-oxadiazol-2-yl-phenoxy)]propyl]-pyridine, as a white crystalline solid, m.p. 87°-89° C.
EXAMPLE 9
A. 3-(4-Pyridyl)-propanol
3-(4-Pyridyl)-propanol was prepared according to the method of 4A-D.
B. 4-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=4-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a suspension of 1 g (3.88 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.53 g (3.88 mmol) of 3-(4-pyridyl)-propanol, and 1.21 g (4.6 mmol) of triphenylphosphine in 10 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 0.81 g (4.6 mmol) of DEAD in methylene chloride, and the resulting mixture was allowed to warm to room temperature. The mixture was concentrated in vacuo and the residue was purifed by MPLC (hexane/ethyl acetate 1:3) to yield 1.5 g (86.1%) of 4-3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a white solid which was triturated in hexane, filtered, concentrated and recrystallized from isopropyl acetate/hexane to afford 0.82 g of a white solid.
EXAMPLE 10 ##STR7## C. 3-[3-[4-(5-Methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]propyl]-pyridine (I, Q=3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-methyl-1,2,4-oxadiazol-3-yl)
To a suspension of sodium hydride (70 mg, 2.8 mmol) and 3-hydroxypyridine (0.24 g, 2.56 mmol) in DMF was added dropwise 1 g (1 g, 2.8 mmol) of 4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxypropyl iodide in DMF, and the mixture was stirred at room temperature for 2 days. The mixture was washed with water, extracted with ethyl acetate, and the organic layer was washed with water and dried over magnesium sulfate. The dry organic layer was concentrated in vacuo, passed through a pad of silica gel eluting with hexane/ethyl acetate (1:1) to afford 0.48 g (55.1%) of 3-[3-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]propyl]-pyridine, as an oil, which crystallized on standing in ether, m.p. 46°-49° C.
EXAMPLE 11
A. 3-(4-Pyridyl)-propanol
The 3-(4-pyridyl)-propanol was prepared according to the method of 4A-D.
B. 4-[3-(2,6-Dimethyl-4-cyanophenoxy)-propyl]-pyridine
2,6-Dimethyl-4-cyanophenol was reacted with the alcohol of Example 12A according to the method of 1D.
C. 4-[3-(2,6-Dimethyl-4-aminohydroximinomethyl-phenoxy)-propyl]-pyridine
The amide oxime was formed from the cyano compound of Example 12B according to the method of 9C.
D. 4-[3-[2,6-Dimethyl-4-(5-difluoromethyl-1,2,4-oxadiazol-2-yl-phenoxy)]propyl]-pyridine (I, Q=4-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-difluoromethyl-1,2,4-oxadiazol-3-yl)
A mixture of 1.15 g (3.6 mmol) of 4-[3-(2,6-dimethyl-4-aminohydroximino-methylphenoxy)propyl]-pyridine and 3.6 ml of ethyl difluoroacetate was heated at 100° C. for 6 h. The above reaction mixture was cooled, diluted with water, and extracted with ether. The organic layer was washed with water (5×100 ml), dried over magnesium sulfate and concentrated in vacuo to yield a residue. The residue was purified by silica gel pad chromatograph (ethyl acetate/hexane, 1:3) to afford 0.65 g (50%) of 4-[3-[2,6-dimethyl-4-(5-difluoromethyl-1,2,4-oxadiazol-2-yl-phenoxy)]propyl]-pyridine, m.p. 84°-86° C.
EXAMPLE 12
A. 2-Fluoro-6-(3-hydroxypropyl)pyridine
To a solution of 2-fluoro-6-methylpyridine (27 mmol) in 65 ml of freshly distilled THF was added via syringe 13.5 ml of 2M LDA, and the resulting mixture was stirred at -78° C. for 20 min. To the above cold solution was added 4 ml of 4M ethylene oxide and the mixture was allowed to warm to room temperature with stirring. The mixture was diluted with water, extracted with ether, and the organic layer was washed with water (2x) and brine, and dried over sodium sulfate. The organic solution was concentrated, and the residue was purified by flash chromatography (chloroform/ethanol, 10:1) to yield 1.3 g (30.9%) of 2-fluoro-6-(3-hydroxypropyl)pyridine, as a yellow oil.
B. 2-Fluoro-6-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I , Q=6-fluoro-2-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-methyl-1,2,4-oxadiazol-3-yl)
To a suspension of 0.66 g (3.22 mmol) of 4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 0.5 g (3.2 mmol) of 3-(2-fluoro-4-pyridyl)-propanol, and 1.27 g (4.83 mmol) of triphenylphosphine in 25 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 0.84 g (4.83 mmol) of DEAD in methylene chloride, and the resulting mixture was allowed to warm to room temperature. The mixture was concentrated in vacuo and the residue was purifed by silica plug chromatography and MPLC (hexane/ethyl acetate, 3:1) to afford 0.61 g (55.5%) of 2-fluoro-6-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a pale oil, which crystallized from t-butylmethyl ether, m.p. 54°-56° C.
EXAMPLE 13
Following the procedures described above in examples 1-13 the following compounds were prepared from known starting materials. ##STR8## Y=(CH 2 )n; Q=m-(R 3 -pyridyl); R 3 =5-R 4 1,2,4-oxadiazolyl; R 1 =R 2
______________________________________Ex. R.sub.5 m = R.sub.l n R.sub.4 m.p.(°C.)______________________________________13a H 3 CH.sub.3 3 CH.sub.3 52-5413b H 3 CH.sub.3 3 CF.sub.3 97-10013c H 3 Cl 3 CH.sub.3 70-7413d H 3 Cl 3 CF.sub.3 66-6913e 6-CH.sub.3 3 CH.sub.3 3 CH.sub.3 --13f 6-CH.sub.3 3 CF.sub.3 3 CF.sub.3 67-6913g H 3 CH.sub.3 3 CF.sub.2 H 87-8913h 2-CH.sub.3 3 CH.sub.3 3 CF.sub.2 H 67-6913i H 3 CH.sub.3 4 CF.sub.3 oil13j 6-F 2 CH.sub.3 3 CH.sub.3 54-5613k 2-CH.sub.3 3 CH.sub.3 3 CF.sub.3 68-70131 H 2 CH.sub.3 3 CF.sub.3 84-8713m N-oxide 3 CH.sub.3 3 CF.sub.3 84-8613n 6-CN 3 CH.sub.3 3 CF.sub.3 131-133______________________________________
EXAMPLE 14
Using the methods described above, compounds of formula I wherein R 3 is 2-methyl-tetrazol-5-yl, Y is of the formula (CH 2 ) n and R 1 and R 2 represent 3,5-dimethyl were prepared by reaction of the appropriate pyridyl alkanol, pyridylalkylhalide of pyridylalkylsilane with 2-methyl-(4-hydroxy-3,5-dimethylphenyl)-2H-tetrazole.
______________________________________Ex Y = Pyr = M.P.______________________________________14a --(CH.sub.2).sub.5 -- 2-pyridyl 50-5214b C═C(CH.sub.2).sub.3 -- 3-pyridyl 80-8214c (CH.sub.2).sub.5 3-pyridyl 43-4414d (CH.sub.2).sub.3 4-pyridyl 99-10614e (CH.sub.2).sub.3 3-pyridyl 64.5-6614f (CH.sub.2).sub.3 6-methyl-3- 72-74 pyridyl14g (CH.sub.2).sub.3 6-ethyl-3-pyridyl 48-5014h (CH.sub.2).sub.5 4-pyridyl 64-6614i (CH.sub.2).sub.3 3-methyl-4-pyridyl 74-7614j (CH.sub.2).sub.3 3-ethyl-4-pyridyl 49-5114k (CH.sub.2).sub.3 5-methyl-3-pyridyl 76-77______________________________________
EXAMPLE 15
Compounds of formula I wherein R 1 , R 2 =3,5-dimethyl and Y is 1,3-propylene were prepared by methods described hereinabove.
______________________________________Ex Pyr = R.sub.3 = M.P.______________________________________a 4-pyrimidyl 2-methyl-tetrazol-5-yl 65-66b 6-methyl-4-pyrimidyl 2-methyl-tetrazol-5-yl 78-79c 6-methyl-4-pyrimidyl 2-methyl-tetrazol-5-yl 50-52d 2-methyl-5-pyrimidyl 5-trifluoromethyl- 103-104 1,2,4-oxadiazol-3yle 2-methyl-5-pyrimidyl 5-methyl-1,2,4- 94-96 oxadiazolylf 2-methyl-5-pyrimidyl 2-methyl-tetrazol-5-yl 89-91______________________________________
EXAMPLE 16
A Ethyl 3-(3-quinolyl)propionate
A mixture of ethyl β-(3-quinolyl)acrylate (100 mg, 0.44 mmol) and 50 mg of 10% Pd/C in ethyl acetate/ethanol (3 ml/1 ml) was hydrogenated under hydrogen (55 psi) for 1 h. The mixture was filtered through celite, the residue was washed with methylene chloride, and the combined organic layer was concentrated in vacuo. Upon chromatographic purification on 20 cm silica column (ethyl acetate/hexane, 1/8-1/2), 49 mg (50%) of ethyl 3-(3-quinolyl)propionate (KUO-1953-136B) and 27 mg (26%) of ethyl 3-(1,2,3,4-tetrahydro-3-quinolyl)propionate was isolated.
B 3-(3-Hydroxypropyl)quinoline
To a cooled (0° C.) solution of ethyl 3-(3quinolyl)propionate (1.01 g, 4.4 mmol) in 20 ml of ether was added 2.6 ml (2.6 mmol) of 1M LAH solution at 0° C. After stirring at 0° C. for 15 min, the mixture was allowed to warm and stirred at 20° C. for 3 h, and Rochelle salt (equiv) was added. The mixture was extracted with methylene chloride, and the organic layer was dried over sodium sulfate, and concentrated in vacuo. The residue was purified by chromatography on silica (10 cm column, ethyl acetete/hexane, 1/2-5/1; methylene chloride/acetone, 2/1-1/4) to afford 700 mg (85%) of 3-(3-hydroxypropyl)quinoline, as a thick oil. 3-[3-[4-(5-Trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-quinoline (I, Q=3-quinolyl Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
A mixture of 3-(3-hydroxypropyl)-quinoline (79 mg, 0.42 mmol), 4-(5-trifluoro-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol (119 mg, 0.46 mmol), and DEAD (80 mg, 0.46 mmol) was dissolved in 4 ml of THF. To the above solution was added triphenylphosphine (120 mg, 0.46 mmol) at 0° C. and the mixture was allowed to warm to 20° C. overnight. The solvent was removed in vacuo, and the residue was partitioned between an aqueous sodium bicarbonate solution and methylene chloride. The aqueous layer was extracted with methylene chloride (3x), and the organic layer dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (20 cm column, ethyl acetate/hexane, 1/5 ) to afford 110 mg (96%) of 3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-quinoline.
D 3-[3-[4-(5-Methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-quinoline (I, Q=3-quinolyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-methyl-1,2,4-oxadiazol-3-yl)
A mixture of 3-(3-hydroxypropyl)-quinoline (250 mg, 1.34 mmol), 4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol (273 mg, 1.34 mmol), and DEAD (256 mg, 1.47 mmol) was dissolved in 12 ml of THF. To the above solution was added triphenylphosphine (385 mg, 1.47 mmol) at 20° C. and the mixture was stirred overnight. The solvent was removed in vacuo, and the residue was partitioned between an aqueous sodium bicarbonate solution and methylene chloride. The aqueous layer was extracted with methylene chloride (3x), and the organic layer dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (20 cm column, ethyl acetate/hexane, from 1/5 to 1/3) to afford 364 mg (73%) of 3-[3-[4-(5-methyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-quinoline, m.p. 105°-107° C.
EXAMPLE 17
A 2-[3-[4-(2-Methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-propyl]-dioxalane
To a mixture of 4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenol (17 g, 83.2 mmol), 170 ml of NMP, potassium carbonate (11.5 g, 83.2 mmol), and 13.8 g (83.2 mmol) of potassium iodide was added 2-(3-chloropropyl)-1,3-dioxalane (11.42 g, 75.6 mmol) dropwise over a 10 min period, and the mixture was stirred at 90° C. overnight. After cooling, the mixture was poured into 900 ml of water and extracted with ether (4×250 ml) . The combined organic layer was washed with 10% NaOH solution, brine (170 ml), and dried over sodium sulfate and filtered. The organic filtrate was concentrated in vacuo, and the residue was purified by recrystallization from methylene chloride/hexane to afford 14.2 g (59%) of 2-[3-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-propyl]-dioxalane, as a light pink solid, m.p. 84°-86° C.
B 4-[4-(2-Methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyraldehyde
2-[3-[4-(2-Methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]propyl]-dioxalane (1 g, 3.1 mmol) was dissolved in 10 ml of acetic acid and 1 ml of water, and the mixture was stirred at 80° C. for 20 h. The solution was basified with 2N NaOH solution, extracted with methylene chloride, and the combined organic layer was dried over sodium sulfate and concentrated (with a crude product from KUO-1376-037) to afford 1.37 g of 4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]butyr-aldehyde.
C 2-[4-[4-(2-Methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-1-hydroxy-butyl]-7-azaindole (Q=7-azaindol-2-yl, Y=1,4-butylene, R 1 , R 2 =3,5-dimethyl, R 3 =2-methyltetrazol-5-yl)
To a cold solution of 1-phenylsulfonyl-7-azaindole (1.29 g, 5 mmol) in 250 ml of THF was added at -30° C. n-BuLi (2.5M in hexane, 4 ml, 10 mmol). The mixture was stirred at -30°-40° C. for 1 h and then cooled to -50° C. To the above mixture was added dropwise at -50° C. a solution of 4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]butyraldehyde (1.37 g, 5 mmol) in 25 ml of THF, and the mixture was stirred at -40°-50° C. for 1 h and then allowed to warm to -5° C. for 2 h. Water was added to the mixture, and the resulting reaction mixture was acidified with 1N HCl solution, and then re-basified with an aqueous sodium bicarbonate solution, extracted with methylene chloride, and the organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (20 cm column, ethyl acetate/hexane, 1/5-1/0; then methylene chloride/acetone 2/1-1/1) followed by recrystallization from methylene chloride/methanol to afford 501 mg (25%) of 2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-1-hydroxy-butyl]-7-azaindole, as a white crystalline solid, m.p.166°-169° C.
D 2-[4-[4-(2-Methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole (I, Q=7-azaindol-2-yl, Y=1,4-butylene, R 1 , R 2 =3,5-dimethyl, R 3 =2-methyl-tetrazol-5-yl)
Triethylsilane (5 ml) was added to a stirred solution of 2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-1-hydroxy-butyl]-7-azaindole (520 mg, 1.33 mmol) in 20 ml of trifluoroacetic acid at 20° C. under nitrogen. The mixture was stirred at 20° C. for 10 min and then stirred at 70°-75° C. for 16 h. To the mixture was added water, and basified with an aqueous sodium bicarbonate solution (to pH=8) followed by extraction with methylene chloride (3x). The combined organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (7.5 cm column, ethyl acetate/hexane, 1/5-8/1) . The mixture was recrystallized to afford 349 mg (74%) of 2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole, as a white solid, m.p. 147°-150° C.
E 1-Methyl-2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole (I, Q=1-methyl-7-azaindol-2-yl, Y=1,4-butylene, R 1 , R 2 =3,5-dimethyl, R 3 =2-methyl-tetrazol-5-yl)
To 150 ml of condensed liquid ammonia was added a trace of ferric nitrate. To the mixture sodium (69 mg, 3 mmol) was slowly added while removing a cold bath. A dark blue solution turned to a black-brown color. To the above solution was added slowly 2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole (376 mg, 1 mmol) in 7.5 ml of THF at -78° C. Methyl iodide (426 mg, 3 mmol) was added to the mixture at -78° C. and the resulting mixture was stirred at -78° C. for 30 min and then was allowed to warm to 20° C. over a 1 h period. The mixture was diluted with water, extracted with methylene chloride, and the organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (10 cm column, ethyl acetate/hexane, 1/5 -4/1) to yield 313 mg (71%) of a solid product which was recrystallized from methylene chloride/hexane to afford 273 mg of 1-methyl-2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole, 117.5°-119.5° C.
F 1-Methyl-2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-1,2-dihydro-7-azaindole (I, Q=2,3-dihydro-1-methyl-7-azaindol-2-yl, Y=1,4-butylene, R 1 , R 2 =3,5-dimethyl, R 3 =2-methyl-tetrazol-5-yl)
A solution of 1-methyl-2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-7-azaindole (580 mg, 1.49 mmol) in 16.5 ml of trifluoroacetic acid was added in portions at 0° C. 1.88 g (29.7 mmol) of sodium borohydride. The mixture was stirred at 20° C. for 30 min and then heated at 55°-60° C. for 72 h. To the above mixture was added water, 2N NaOH solution (to pH=8), and the resulting mixture was extracted with methylene chloride. The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography (10 cm column, methylene chloride/acetone, 30/1-6/1) to yield 193 mg (33%) of 1-methyl-2-[4-[4-(2-methyl-tetrazol-5-yl)-2,6-dimethylphenoxy]-butyl]-2,3-dihydro-7-azaindole, as a solid, m.p. 54°-57° C.
G. Using the methods described above, compound of formula I wherein Q=2,3-dihydro-1-methyl-7-azaindolyl, Y=1,4-butylene, R 1 , R 2 =3,5-dimethyl and R 3 is 2-ethyl-tetrazol-5-yl; M.P. 75°-77° C.
EXAMPLE 18
A. 6-Methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine I, Q=6-methyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 3.6 g (14 mmol) of 4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenol, 2.5 g (2 eq) of 6-methyl-3-(3-hydroxypropyl)-pyridine, (Int. 1C) 4.5 g (1.2 eq) of triphenylphosphine in 60 ml of methylene chloride under nitrogen at 0° C. was added dropwise a solution of 2.8 g (1.2 eq) of DEAD in 5 ml of methylene chloride. After 16 h, the mixture was concentrated in vacuo and the residue was purifed by MPLC (50 mm id Kieselgel 60 column; hexane/ethyl acetate 1:1) to yield 5.5 g of the product. Recrystallizations from t-butylmethylether/hexane as well as hexane (2nd recrystallization) afforded 2.88 g (52%) of 6-methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine.
B. 6-Methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine-N-oxide (I, Q=6-methyl-3-pyridyl-N-oxide, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 1.08 g (2.8 mmol) of 6-methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethytphenoxy]propyl]-pyridine in 30 ml of methylene chloride was added 0.71 g (1.5 eq) of m-chloroperbenzoic acid (MCPBA). The mixture was stirred under nitrogen for 18 h at room temperature, poured into saturated sodium bicarbonate solution, and the organic layer was separated and dried over sodium sulfate. The organic layer was fitered, concentrated, and the residue was recrystallized from isopropyl acetate/hexane to afford 0.93 g (83%) of 6-methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine-N-oxide, as white needles, m.p. 119°-121° C.
C. 6-Chloromethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-chloromethyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 1.8 g (4.4 mmol) of 6-methyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine-N-oxide in 18 ml of methylene chloride was added dropwise a solution of 0.41 ml (1.13 eq) POC 13 in 4 ml of methylene chloride. After addition of 10% of POC 13 solution, triethylamine (0.54 ml; 1.1 eq) in 4 ml of methylene chloride was added in portions. The exothermic mixture was stirred for 30 min, washed with saturated ammonium chloride solution, and the organic layer was separated and dried over sodium sulfate. The organic layer was concentrated in vacuo and purified by flash filtration through silica gel (hexane/ether, 2:1) to afford 0.59 g (31%) of 6-chloromethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethyl-phenoxy]-propyl]-pyridine (BIL-1991-187), as a pale yellow oil which solidified upon standing, m.p. 79°-81° C.
D. 6-Methoxymethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-methoxymethyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of NaOMe in methanol (15 mg, 1 eq of 95% of NaH) was added 0.24 g (0.56 mmol) of 6-chloromethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethyl-phenoxy]-propyl]-pyridine. The suspension was brought to reflux thereby all solid dissolved and a mixture was allowed to cool to room temperature under nitrogen. The reaction mixture was allowed to reflux under nitrogen for 8 h. Upon cooling the mixture was diluted with ethyl acetate, the organic layer was washed with sat. ammonium chloride solution, dried over sodium sulfate, and concentrated in vacuo to yield 0.17 g of an orange semisolid. The solid was purified by preparative tlc (2000 micron silica gel; hexane/ethyl acetate, 3:2) to afford 0.1 g (41.7%) of 6-methoxymethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine as a colorless oil which solidified upon cooling in vacuo, m.p. 50°-53° C.
E. 6-Hydroxymethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine (I, Q=6-hydroxymethyl-3-pyridyl, Y=1,3-propylene, R 1 ,R 2 =3,5-dimethyl, R 3 =5-trifluoromethyl-1,2,4-oxadiazol-3-yl)
To a solution of 0.21 g (0.49 mmol) of 6-chloromethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine in 8 ml of DMF (dry, 3 A° sieves) under nitrogen at room temperature was added 0.12 g (1.1 eq) of AgTFA and the mixture was stirred under nitrogen for 20 h. The mixture was filtered through celite eluting with ethyl acetate, the organic layer was washed with water (4x), dried over sodium sulfate and concentrated in vacuo to yield 0.22 g of a pink oil (a mixture of starting material and the product, 2:1). The oil was resubjected to the reaction condition (0.2 g of AgTFA) stirring for 3 days followed by an addition of 0.1 g of AgTFA and stirring for 24 h at room temperature. The mixture was filtered through celite eluting with ethyl acetate, the organic layer was washed with water, dried over sodium sulfate and concentrated in vacuo to yield 0.17 g of a pink oil. The pink oil was dissolved in 10 ml of methanol and 10 drops of diethylamine, stirred for 1.5 h, and concentrated. The residue was purified by preparative tlc (2000 micron silica gel; chloroform/ethanol, 10:1) followed by recrystallization from isopropyl acetate/hexane to afford 1 mg (45.5%) of 6-hydroxymethyl-3-[3-[4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)-2,6-dimethylphenoxy]-propyl]-pyridine, as a white soilid, m.p. 92°-94° C.
EXAMPLE 19
As further examples, phenols described only generally thus far can be reacted with any (Q)alkanol or (Q)alkyl halide described above using the methods previously described to provide a compound of compound of formula I. For the reader's convenience the same nomenclature conventions described herein for compounds of formula I are adhered to, and a literature reference describing the known phenol is included.
__________________________________________________________________________ ReferenceR.sub.1 R.sub.2 R.sub.3 U.S. Pat. Nos.__________________________________________________________________________H H 1,2,4-oxadiazol-2yl 4,857,539H H 4,2-dimethyl-2-thiazolyl 4,857,539H H 2-benzoxazolyl 4,857,5393,5 dichloro 3-furanyl 4,857,5393,5 dichloro 2-furanyl 4,857,5393,5 dichloro 2-thienyl 4,857,5393,5 dichloro 2-pyridinyl 4,857,5393,5 dichloro 1-methyl-1H-pyrrol-2yl 4,857,5393,5 dichloro 3-thienyl 4,857,5393,5 dichloro 4-pyridinyl 4,857,5393 nitro H benzothiazol-2-yl 4,857,539H H 2-(4,5-dihydro-4 methyl)oxazolyl 4,843,0873 methyl H 2-oxazolyl 4,843,0873 bromo H 2-oxazolyl 4,843,0873,5 dimethyl 3-methyl-5-isoxazolyl 4,843,0872,6 dimethyl 3-methyl-5-isoxazolyl 4,843,087H H 5-methyl-3-isoxazolyl 4,942,241H H 4-hydroxy phenyl (Aldrich)H H phenyl (Aldrich)H H 5-ethyl-thiazol-2-yl 5,100,893H H 4,5-dimethyl-thiazol-2-yl 5,100,893H H 2-ethyl-thiazol-4-yl 5,100,893H H 5-ethyl-1,3,4-thiadiazol-2-yl 5,100,893H 3-Cl 3-ethyl-1,2,4-oxadiazol-5-yl 5,100,893H H 3-cyclopropyl-1,2,4-oxadiazol-5-yl 5,100,893H H 3-tbutyl-1,2,4-oxadiazolyl 5,100,893H H 5-ethyl-1,3,4-oxadiazol-2-yl 5,100,893H H 3-cyclopropyl,2,4-oxadiazol-5-yl 5,100,893H H 3-ethyl-1,3,4-thiadiazol-5-yl 5,100,893H H 3-(2hydroxy)propyl- 5,100,893 1,2,4-oxadiazol-5-ylH H 4-ethyl-3-thiazol-2-yl 5,100,893H H 5-ethyl-3-thiazol-2-yl 5,100,8933-chloro H 3-ethyl-1,2,4-oxadiazol-5-yl 5,100,893H H 4,5-dimethyl-3-thiazol-2-yl 5,100,8932-methoxy H 4,5dihydro oxazol-2-yl 4,843,0873-methoxy H 4,5dihydro oxazol-2-yl 4,843,0873-chloro H 4,5dihydro oxazol-2-yl 4,843,0873-hydroxy H 4,5dihydro oxazol-2-yl 4,843,0873,5 di-t-butyl 4,5dihydro oxazol-2-yl 4,843,0873-difluoromethyl H 4,5dihydro oxazol-2-yl 4,843,0873-hydroxymethyl H 4,5dihydro oxazol-2-yl 4,843,0873-carboxy H 4,5dihydro oxazol-2-yl 4,843,0872-methyl 3-hydroxy 4,5dihydro oxazol-2-yl 4,843,0872,6 dichloro 4,5dihydro oxazol-2-yl 4,843,0873,5 difloro 4,5dihydro oxazol-2-yl 4,843,0873-chloro 5-ethynyl 4,5dihydro oxazol-2-yl 4,843,087__________________________________________________________________________
EXAMPLE 20
D. It is contemplated that any known hydroxy (Q) compound can be used to prepare the corresponding triflate which can then be reacted with the compound of example 11B under the conditions of example 11C to form compounds of formula I; examples of such compounds include:
4-hydroxy pyrimidine;
2-hydroxy pyrimidine;
4,6-pyrimidine diol;
2,4-pyrimidine dione (uracil);
2-hydroxy pyridine;
3-hydroxy pyridine;
4-hydroxy pyridine;
2-hydroxy-5-pyridine carboxylic acid;
3-hydroxy-2-pyridine carboxylic acid;
2,4-dihydroxy pyridine;
3-hydroxy pyrazine;
2-hydroxy pyrazine;
2-hydroxy-5-methyl pyrazine;
4-hydroxy-5-methyl pyrimidine;
2-hydroxy-4-methylpyrimidine;
2-hydroxy-4-chloro pyridine;
3-hydroxy-4-methyl pyridine;
3-hydroxy-2-methyl pyrimidine;
5-hydroxypyrimidine;
6-hydroxy pyrimidine;
2-hydroxy pyrazine;
3-hydroxy pyrazine;
2-hydroxy-5-methyl pyrazine;
2-hydroxy-6-methyl pyrazine;
3-hydroxy-6-methyl pyrazine;
3-hydroxy-5-methyl pyrazine;
3-hydroxy-5-methoxy pyrazine;
2-hydroxy-6-methoxy pyrazine;
5-(2-hydroxy pyrazine)carboxylic acid;
2-amino-4-hydroxy pyrimidine (which can be oxidized to 2-nitro-4-hydroxy pyrimidine)
(This list is not exhaustive, but exemplary in nature. Thus nothing in this list is intended to limit the claims thereto.)
BIOLOGICAL PROPERTIES
Biological evaluation of representative compounds of formula I has shown that they possess antipicornaviral activity. They are useful in inhibiting picornavirus replication in vitro and are primarily active against picornaviruses, including enteroviruses, echovirus and coxsackie virus, especially rhinoviruses. The in vitro testing of the representative compounds of the invention against picornaviruses showed that picornaviral replication was inhibited at minimum inhibitory concentrations (MIC) ranging from to micrograms per milliliter (μg/ml).
The MIC values were determined by an automated tissue culture infectious dose 50% (TCID-50) assay. HeLa cells in monoloyers in 96-well cluster plates were infected with a dilution of picornavirus which had been shown empirically to produce 80% to 100% cytopathic effect (CPE) in 3 days in the absence of drug. The compound to be tested was serially diluted through 10, 2-fold cycles and added to the infected cells. After a 3 day incubation at 33° C. and 2.5% carbon dioxide, the cells were fixed with a 5% solution of glutaraldehyde followed by staining with a 0.25% solution of crystal violet in water. The plates were then rinsed, dried, and the amount of stain remaining in the well (a measure of intact cells) was quantitated with an optical density reader. The MIC was determined to be the concentration of compound which protected 50% of the cells from picornavirus-induced CPE relative to an untreated picornavirus control.
In the above test procedures, representative compounds of formula I were tested against some the serotypes from either a panel of fifteen human rhinopicornavirus (HRV) serotypes, (noted in the table as panel T) namely, HRV-2, -14, -1A, -1B, -6, -21, -22, -15, -25, -30, -50, -67, -89, -86 and -41 or against some of the serotypes from a panel of 10 human rhinopicornavirus serotypes namely HRV-3, -4, -5, -9, -16, -18, -38, -66, -75 and -67, (noted in the table as panel B) and the MIC value, expressed in micrograms per milliliter (mg/ml), for each rhinopicornavirus serotype was determined for each picornavirus, example 1e is given as an example of the data. Then MIC 50 and MIC 80 values, which are the minimum concentrations of the compound required to inhibit 50% and 80%, respectively, of the tested serotypes were determined. The compounds tested were found to exhibit antipicornaviral activity against one or more of these serotypes.
The following Table gives the test results for representative compounds of the invention. The panel of picornaviruses used in the test appears before the the MIC 80 and MIC 50 figure and the number of serotypes which the compound is tested against (N) is indicated after the MIC 80 and MIC 50 figure.
TABLE______________________________________Ex Panel Mic.sub.50 Mic.sub.80 N______________________________________le B 0.149 0.663 102e T 0.185 2.84 133e T 0.0905 0.167 143f B 0.87 -- 93g B 0.41 0.61 105d B 0.082 0.627 107d B 0.1615 0.793 108d B 0.0475 -- 89d T -- 0.283 1510c T 0.48 2.293 1511d B 0.082 0.627 1013a T 0.064 0.618 1513b T 0.073 0.122 1513c T 0.036 0.353 1513d T 0.161 0.29 1513e T 0.043 0.133 1413f B 0.0895 0.36 1013g B 0.0475 -- 813h B 0.0335 0.112 1013i T 0.493 -- 1313j T 0.139 0.313 1513k B 2.0 2.41 1013l B 0.0855 0.48 1013m B 0.15 0.185 914a T 0.384 0.621 914b B 0.076 .4 714c B 0.12 0.076 714e T 0.02 0.18 1514f T 0.281 0.957 1514g B 0.136 .15 714h T 0.035 0.22 1514i T 0.076 0.512 1214j T 0.1145 0.346 1214k B 0.18 0.71 715a T 0.224 3.173 1515b T 0.291 1.335 1115c T 0.395 -- 1115d B 0.089 0.208 515e B 0.166 0.869 515f T 0.229 1.084 1316b B 1.9 1.9 1016d B 1.0 4.3 1017e T 0.224 3.173 1117g T 0.2835 0.704 14______________________________________ -- = insufficient data or inactive
FORMULATIONS OF THE INVENTION
The compounds of formula I can be formulated into compositions, including sustained release compositions together with one or more non-toxic physiologically acceptable carriers, adjuvants or vehicles which are collectively referred to herein as carriers, in any conventional form, using conventional formulation techniques for preparing compositions for treatment of infection or for propylactic use, using formulations well known to the skilled pharmaceutical chemist, for parenteral injection or oral or nasal administration, in solid or liquid form, for rectal or topical administration, or the like.
The compositions can be administered to humans and animals either orally, rectally, parenterally (intravenous, intramuscularly or subcutaneously), intracisternally, intravaginally, intraperitoneally, locally (powders, ointments or drops), or as an aerosal, for example as a nasal or a buccal spray.
Compositions suitable for parenteral injection can comprise physiologically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions and sterile powders for reconstitution into sterile injectable solutions or dispersions. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (propyleneglycol, polyethyleneglycol, glycerol, polyalkylene glycols and the like), suitable mixtures thereof, vegetable oils (such as olive oil) and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersions and by the use of surfactants.
These compositions can also contain adjuvants such as preserving, wetting, emulsifying, and dispensing agents. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents that delay absorption, for example, aluminum monostearate and gelatin.
Solid dosage forms for oral administration include capsules, tablets, pills, powders, lozenges and granules which may be dissolved slowly in the mouth, in order to bathe the mouth and associated passages with a solution of the active ingredient. In such solid dosage forms, the active compound is admixed with at least one inert customary excipient (or carrier) such as sodium citrate or dicalcium phosphate or (a) fillers or extenders, as for example, starches, lactose, sucrose, glucose, mannitol and silicic acid, (b) binders, as for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and acacia, (c) humectants, as for example, glylcerol, (d) disintegrating agents, as for example, agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates and sodium carbonate, (e) solution retarders, as for example paraffin, (f) absorption accelerators, as, for example, quaternary ammonium compounds, (g) wetting agents, as for example, cetyl alcohol and glycerol monostearate, (h) adsorbents, as, for example, kaolin and bentonite, and (i) lubricants, as, for example, talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate or mixtures thereof. In the case of capsules, tablets and pills, the dosage forms can also comprise buffering agents.
Certain solid dosage forms can be delivered through the inhaling of a powder manually or through a device such as a SPIN-HALER used to deliver disodium cromoglycate (INTAL). When using the latter device, the powder can be encapsulated. When employing a liquid composition, the drug can be delivered through a nebulizer, an aerosol vehicle, or through any device which can divide the composition into discrete portions, for example, a medicine dropper or an atomizer.
Solid compositions of a similar type may also be formulated for use in soft and hard gelatin capsules, using such excipients as lactose or milk sugar as well as high molecular weight polyethyleneglycols, and the like.
Solid dosage forms such as tablets, dragees, capsules, pills and granules can be prepared with coatings and shells, such as enteric coatings and others well known in the art. They can contain opacifying agents, and can also be of such composition that they release the active compound or compounds in a certain part of the intestinal tract in a delayed manner.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. Also solid formulations can be prepared as a base for liquid formulations. In addition to the active compounds, the liquid dosage forms can contain inert diluents commonly used in the art, such as water or other solvents, solubilizing agents and emulsifiers, as for example, ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propyleneglycol, 1,3-butyleneglycol, dimethylformamide, oils, particularly cottonseed oil, ground-nut oil, corn germ oil, olive oil, castor oil and sesame oil, glycerol, tetrahydrofurfuryl alcohol, polyethyleneglycols and fatty acid esters of sorbitan or mixtures of these substances, and the like. Besides such inert diluents, the composition can also include adjuvants, such as wetting agents, emulsifying and suspending agents, sweetening, flavoring and perfuming agents.
Suspensions, in addition to the active compounds, can contain suspending agents, as for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol, polyethyleneglycols of varying molecular weights and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances, and the like.
Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of the present invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethyleneglycol or a suppository wax, which are solid at ordinary temperatures bun liquid at body temperature and, therefore, melt in the rectum or vaginal cavity and release the active component.
Compositions for administration as aerosols are prepared by dissolving a compound of Formula I in water or a suitable solvent, for example an alcohol ether, or other inert solvent, and mixing with a volatile propellant and placing in a pressurized container having a metering valve to release the material in useful droplet size.
The liquefied propellant employed typically one which has a boiling point below ambient temperature at atmospheric pressure. For use in compositions intended to produce aerosols for medicinal use, the liquefied propellant should be non-toxic. Among the suitable liquefied propellants which can be employed are the lower alkanes containing up to five carbon atoms, such as butane and pentane, or a alkyl chloride, such as methyl, ethyl, or propyl chlorides. Further suitable liquefied propellants are the fluorinated and fluorochlorinated alkanes such as are sold under the trademarks "Freon" and "Genetron". Mixtures of the above mentioned propellants can suitably be employed.
Preferred liquefied propellants are chlorine free propellants, for example 134a (tetrafluoroethane) and 227c (heptafluoropropane) which can be used as described above. Typically, one uses a cosolvent, such as an ether, alcohol or glycol in such aerosol formulations.
The specifications for unit dosage forms of this invention are dictated by and directly dependent on (a) the unique characteristics of the active material and the particular effect to be achieved and (b) the limitations inherent in the art of compounding such an active material for use in humans and animals, as disclosed in detail in this specification, these being features of the present invention. Examples of suitable unit dosage forms in accord with this invention are capsules adapted for ingestion or, aerosols with metered discharges, segregated multiples of any of the foregoing, and other forms as herein described.
Compounds of the invention are useful for the prophylaxis and treatment of infections of suspected picornaviral etiologies such as aseptic meningitis, upper respiratory tract infection, enterovirus infections, coxsackievirus, enteroviruses and the like. An effective but non-toxic quantity of the compound is employed in treatment. The dosage of the compound used in treatment depends on the route of administration, e.g., intra nasal, intra bronchial, and the potency of the particular compound.
Dosage forms for topical administration include ointments, powders, sprays and inhalants. The active component is admixed under sterile conditions with a physiologically acceptable carrier and any preservatives, buffers or propellants as may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated.
It will be appreciated that the starting point for dosage determination, both for prophylaxis and treatment of picornaviral infection, is based on a plasma level of the compound at roughly the minimum inhibitory concentration levels determined for a compound in the laboratory. For example a MIC of 1 μg/mL would give a desired starting plasma level of 0.1 mg/dl and a dose for the average 70 Kg mammal of roughly 5 mg. It is specifically contemplated that dosage range may be from 0.01-1000 mg.
Actual dosage levels of the active ingredient in the compositions can be varied so as to obtain an amount of active ingredient that is effective to obtain a desired therapeutic response for a particular composition and method of administration. The selected dosage level therefore depends upon the desired therapeutic effect, on the route of administration, on the desired duration of treatment and other factors and is readily determined by those skilled in the art.
The formulation of a pharmaceutical dosage form, including determination of the appropriate ingredients to employ in formulation and determination of appropriate levels of active ingredient to use, so as to achieve the optimum bioavailability and longest blood plasma halflife and the like, is well within the purview of the skilled artisan, who normally considers in vivo dose-response relationships when developing a pharmaceutical composition for therapeutic use.
Moreover, it will be appreciated that the appropriate dosage to achieve optimum results of therapy is a matter well within the purview of the skilled artisan who normally considers the dose-response relationship when developing a regimen for therapeutic use. For example the skilled artisan may consider in vitro minimum inhibitory concentrations as a guide to effective plasma levels of the drug. However, this and other methods are all well within the scope of practice of the skilled artisan when developing a pharmaceutical.
It will be understood that the specific dose level for any particular patient will depend upon a variety of factors including the body weight, general health, sex, diet, time and route of administration, rates of absorption and excretion, combination with other drugs and the severity of the disease being treated and is readily determined by the skilled clinician.
When administered prior to infection, that is, prophylactically, it is preferred that the administration be within about 0 to 48 hours prior to infection of the host animal with the pathogenic picornavirus. When administered therapeutically to inhibit an infection it is preferred that the administration be within about a day or two after infection with the pathogenic virus.
The dosage unit administered will be dependent upon the picornavirus for which treatment or prophylaxis is desired, the type of animal involved, its age, health, weight, extent of infection, kind of concurrent treatment, if any, frequency of treatment and the nature of the effect desired.
The compound of the invention also finds utility in preventing the spread of picornaviral infection. The compounds can be used in aerosol sprays applied to contaminated surfaces, to disposable products, such as tissues and the like used by an infected person. In addition the compounds can be used to impregnate household products such as tissues, other paper products, disposable swabs, and the like to prevent the spread of infection by inactivating the picornavirus.
Because compounds of the invention are able to suppress the growth of picornaviruses when added to a medium in which the picornavirus is growing, it is specifically contemplated that compounds of the invention can be used in disinfecting solutions, for example in aqueous solution with a surfactant, to decontaminate surfaces on which polio, Coxsackie, rhinovirus and/or other picornaviruses are present, such surfaces including, but not limited to, hospital glassware, hospital working surfaces, restuarant tables, food service working surfaces, bathroom sinks and anywhere else that it is expected that picornaviruses may be harbored.
Hand contact of nasal mucus may be the most important mode of rhinovirus transmission. Sterilization of the hands of people coming into contact with persons infected with rhinovirus prevents further spread of the disease. It is contemplated that a compound of the invention incorporated into a hand washing or hand care procedure or product, inhibits production of rhinovirus and decreases the likelihood of the transmission of the disease.
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Compounds of the formula ##STR1## wherein Q is chosen from the group consisting of pyridyl, pyrazyl, pyrimidyl, quinolyl, indolyl and 7-azaindolyl or any of these substituted with one or two substituents;
Y is an alkylene bridge of 3-9 carbon atoms;
R 1 and R 2 are each independently chosen from hydrogen, halo, alkyl, alkenyl, amino, alkylthio, hydroxy, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkoxy, nitro, carboxy, alkoxycarbonyl, dialkylaminoalkyl, alkylaminoalkyl, aminoalkyl, difluoromethyl, trifluoromethyl or cyano;
R 3 is alkoxycarbonyl, alkyltetrazolyl, substituted or unsubstituted phenyl or heterocyclyl, the N-oxide thereof, or a pharmaceutically acceptable acid addition salt thereof is an effective antipicornaviral agent.
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BACKGROUND OF THE INVENTION
The sulfated octapeptide ##EQU2## has been found to possess cholecystokinin activity. As such it stimulates gall bladder contraction and is useful as a diagnostic aid in x-ray examination of the gall bladder in the same manner as cholecystokinin. For such purposes the sulfated octapeptide may be dissolved in water for injection to form an injectable which is administered either intravenously or subcutaneously to mammalian species, e.g., dogs or cats.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide compositions of ##EQU3## which are stable and retain the efficacy of the octapeptide during storage. Another object is to provide methods for preparing the stabilized compositions of the present invention. These and other objects of the present invention will be apparent from the following description.
SUMMARY OF THE INVENTION
A stable composition of the sulfated octapeptide ##EQU4## is obtained by lyophilizing an aqueous solution of the sulfated octapeptide and sodium chloride.
DETAILED DESCRIPTION
A stable composition of the sulfated octapeptide, ##EQU5## comprises a lyophilized powder of the sulfated octapeptide and sodium chloride.
The preparation of the sulfated octapeptide per se is described in U.S. Pats. 3,723,406 and 3,734,946. The disclosure of these patents are incorporated herein by reference. As indicated therein the sulfated octapeptide possesses cholecystokinin activity, that is it stimulates gall bladder contraction and so is useful as a diagnostic aid in X-ray examination of the gall bladder in the same manner as cholecystokinin.
The compositions of the present invention are prepared from an aqueous solution of the sulfated octapeptide and sodium chloride. A liter of this solution contains 2500 mcg and 21.43 g of sodium chloride. The pH is adjusted with sufficient sodium hydroxide (as 1 N solution) or hydrochloric acid (as 1 N solution), if necessary, to adjust the pH to from 5.50 to 6.50.The solution is brought to a volume of 1 liter by the addition of a sufficient quantity of water for injection.
The foregoing solution is sterilized by filtration, aseptically filled into sterile vials, lyophilized, and sealed after filling the head space in the vial with sterile filtered anhydrous nitrogen. The sealed vials are then stored at temperatures of 5°C or below.
The lyophilized composition contains the sulfated octapeptide and sodium chloride. It has been found convenient to fill the vials before lyophilization with 2.1 ml of a solution prepared as described above. The resulting vial after lyophilization then contains 5.25 mcg of sulfated octapeptide and 45.0 mg of sodium chloride.
The lyophilized material has excellent stability on storage and is readily reconstituted for injection by the addition of sterile water for injection. Preferably, the quantity of water for injection used for reconstitution is that amount which forms an isotonic solution.
The following example illustrates the present invention without, however, limiting the same thereto. The sulfated octapeptide in each of the following examples is ##EQU6##
EXAMPLE
The solution is prepared by adding 2500 mcg of ##EQU7## and 21.43 g of sodium chloride to about 900 ml of water for injection, USP. If necessary, the pH is adjusted to between 5.50 and 6.50 with addition of slight amount of either a 1 N solution of sodium hydroxide or a 1 N solution of hydrochloric acid. The volume is then adjusted to 1.0 liter by addition of water for injection, USP.
The solution is then filtered through a sterilizing membrane, and filled aseptically into 5 cc vials at 2.1 ml/vial. The vials are stoppered with fluted stoppers in the raised position and frozen. The vials are then lyophilized for 24 hours at a temperature of -30°C, then for 46 hours at a temperature of 25°C, and finally for one hour at a temperature of 37°C. The vials are then vented with dry sterile nitrogen and the stoppers placed in the closed position. The vials are then sealed and stored at a temperature of -20°C or lower.
The lyophilized vial is reconstituted by addition of 5 ml of sterile water for injection.
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A stable composition of the sulfated octapeptide, ##EQU1## having cholecystokinin activity, is obtained by lyophilizing an aqueous solution of the octapeptide and NaCl.
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FIELD OF THE INVENTION
The invention relates generally to golf accessories and, more particularly, to a clip for attaching a towel to a golf club.
BACKGROUND
Golf is played outdoors in various weather and environmental conditions. Golf equipment and golf balls generally get dirty from grass, dirt, mud, sand, and other environmental agents.
Many golfers carry a towel that is removably secured to a golf bag to wipe golf balls and clubs from time to time, as well as their hands in the event they become muddy or wet from perspiration. Over time, carrying a towel may become burdensome and golfers therefore tend to leave towels fastened to their bags, golf carts and the like.
As is known, golf carts and other wheeled devices are forbidden to travel on the greens of most, if not all, golf courses. As a result, any golfer who is not carrying a towel on his or her person is likely to leave the towel in the cart on a nearby cart path, or in his/her golf bag, and then walk onto the green before realizing that he or she needs to wipe the ball. Examples of conditions making it important to clean the ball are wet greens, wet sand in traps, fertilizer on the greens, and other conditions as listed above. As is also known, when the ball is on the putting green it is permissible to use a ball marker to spot where the ball lies, lift the ball, and then proceed to wipe the ball before putting. It is important to clean the ball before putting for, if the golf ball is not clean, the trajectory of the ball may be affected. If the towel has been left on the cart, however, any convenient item of clothing or even putting the ball to the mouth becomes the means by which most golfers proceed to clean their balls, for to return to the cart or golf bag for the towel would require extra effort and delay the game. In some situations, golfers may even lick the ball or stick the ball in their mouth or spit on the ball, then wipe the ball on their shirt or pants to clean the ball.
SUMMARY
The present invention addresses the foregoing problems by providing a clip to attach a towel to a golf club. As a result, golfers using a clip in accordance to the present invention are able to clean balls with the attached towel before putting. The clip has an aperture to receive the golf club and another aperture to receive a towel. The clip may also utilize a fastener for fastening the towel to the clip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-D provide sketch views of a clip, in accordance with some embodiments of the present invention, where the aperture for the towel is approximately perpendicular to the axis of the aperture which receives the golf club.
FIGS. 2A-D provide sketch views of a clip, in accordance with some embodiments of the present invention, in which the aperture adapted to receive the towel is approximately parallel to the aperture adapted to receive the golf club.
FIGS. 3A-D provide sketch views of a clip, in accordance with some embodiments of the present invention, wherein the aperture adapted to receive the towel is approximately perpendicular to the aperture adapted to receive the golf club.
FIG. 4 shows an exploded view of a clip, in accordance with some embodiments of the present invention, wherein the towel is attached to the clip with a fastener.
FIG. 5 shows a clip, in accordance with some embodiments of the present invention, wherein the towel is attached with a rivet.
FIG. 6 shows a clip, in accordance with some embodiments of the present invention, in which a magnet is used.
FIGS. 7A-D are flow diagrams of methods to attach a clip to a golf club, and to manufacture a clip for attaching a towel to a golf club, in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1A, a clip 100 is shown in perspective. In some embodiments, as shown in FIGS. 1A-D, clip 100 is designed such that the axis of interior chamber 101 is approximately perpendicular to the plane of aperture 105 . Clip 100 has an integral structure and is made of a reasonably tough, resilient elastomeric material. In some embodiments, clip 100 may be made of plastic, metal, ceramic, or other materials. Clip 100 has sufficient rigidity to maintain its shape but sufficient resiliency to flex enough for its intended function, as detailed below. Clip 100 has two arms 102 and 103 joined together at one end and spaced apart at the other end to define an opening 104 . Together arms 102 and 103 enclose an interior chamber 101 . Clip 100 is designed to receive and hold in place in chamber 101 a member (not shown). The member may be cylindrical. A variety of members could be used in accordance to the principles of the invention. The member may be, for example, a solid rod or the shaft of a golf club.
The body of clip 100 may be molded or otherwise formed or manufactured to define an interior chamber 101 , shaped substantially as shown in FIG. 1 A. In some embodiments, clip Lit. 100 may be machined or may be injection molded. The dimensions of various portions of chamber 101 will be determined by the diameter of the members for which they are intended. The diameter of the cylindrical members desired to be held by clip 100 in any given embodiment is selected to fit that particular diameter. In some embodiments, clip 100 may be designed such that it holds the member snugly so as not to slide along the member. In some embodiments, the taper of the club shaft will prevent clip 100 from sliding along the shaft.
In some embodiments, the width of opening 104 when clip 100 is in an unflexed state is selected to be smaller than the diameter of the member to be held. In order to allow the member to enter chamber 101 , arms 102 and 103 flex outwardly. The elasticity of the material of the clip resists this localized flexing. In some embodiments, a magnet may be embedded in clip 100 proximate to chamber 101 such that the magnet attaches the clip to magnetic members placed in chamber 101 .
In addition, clip 100 has an aperture 105 . In some embodiments, the plane of aperture 105 is approximately perpendicular to the axis of opening 101 . Aperture 105 has an opening 106 , which may receive substantially planar items such as a towel (not shown). The planar item, such as a towel, may be inserted into opening 106 with or without the flexure of arms 107 and 108 .
In some embodiments, as shown in FIGS. 2A-D, clip 200 is designed such that the axis of interior chamber 201 is approximately parallel to the plane of aperture 205 . In some embodiments, the width of opening 204 when clip 200 is in an unflexed state is selected to be smaller than the diameter of the member to be held. In order to allow the member to enter chamber 201 , arms 202 and 203 flex outwardly. The elasticity of the material of the clip resists this localized flexing. In other embodiments, a magnet may be embedded in clip 200 proximate to chamber 201 such that the magnet attaches the clip to magnetic members placed in chamber 201 .
Clip 200 has an aperture 205 . In some embodiments, as shown in FIG. 2C, the plane of aperture 205 is approximately parallel to the axis of opening 201 . Aperture 205 has an opening 206 , which may receive substantially planar items such as a towel (not shown). The planar item, such as a towel, may be inserted into opening 206 with or without the flexure of arms 207 and 208 . The towel may be attached to clip 200 using a fastener.
In some embodiments, as shown in FIG. 3, aperture 305 is a through hole. Aperture 305 could be of any number of cross-sectional shapes. Clip 300 has two arms 302 and 303 joined together at one end and spaced apart at the other end to define an opening 304 . Together arms 302 and 303 enclose an interior chamber 301 . Clip 300 is designed to receive and hold in place a member (not shown) in chamber 301 . In some embodiments, aperture 305 may receive an item such as a towel. In some embodiments, aperture 305 may receive a fastener which is used to attach an item such as a towel to clip 300 .
In some embodiments, as shown in FIG. 4, towel 402 is attached to clip 400 with a fastener 401 . Clip 400 , in turn, is attached to a club shaft 403 . Fastener 401 is inserted through opening 404 and protrudes at least partially into aperture 405 . In some embodiments, fastener 401 may be a pop rivet, a threaded member, a strap, or other type of fastener. In some embodiments, fastener 401 is removably fastened.
In some embodiments, as shown in FIG. 5, towel 502 is attached to clip 500 with a rivet 501 .
In some embodiments, as shown in FIG. 6, clip 600 contains a magnet 606 . Magnet 606 is located proximate to an interior chamber 601 . Magnet 606 may attach clip 600 to a metallic member.
As shown in FIG. 7A, a method 710 of attaching a towel to a golf club, in accordance with some embodiments of the present invention, comprises spreading bendable tongs (step 711 ) and inserting the golf club into the aperture (step 712 ).
As shown in FIG. 7C, a method 700 of manufacturing a clip in accordance with some embodiments of the present invention. Method 700 includes step 701 , manufacturing an aperture to receive a portion of a golf club, and step 702 , manufacturing a second aperture to allow for attachment of a towel. The clip may be manufactured by machining, plastic injection molding or other techniques known in the art. A towel is attached using a fastener thorough the second aperture (step 703 ).
A method 705 of manufacturing a clip in accordance with some embodiments of the present invention, shown in FIG. 7 D. Method 705 includes step 706 , manufacturing an aperture to receive a portion of a golf club, and step 707 , manufacturing a second aperture to allow for attachment of a towel. A towel is inserted into the second aperture (step 708 ), and the towel is fastened with a fastener inserted at least partially through the second aperture (step 709 ).
A method 720 of attaching a towel to a golf club consisting of attaching the clip body to the golf club (step 721 ), as shown in FIG. 7 B.
Embodiments described above illustrate, but do not limit the invention. In particular, the invention is not limited to any specific material or dimensions used for the clip. In addition, clips may be constructed by any processes known in the art, in accordance with the principles of the present invention. Other embodiments and varieties are within the scope of the invention, as defined by the following claims.
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A clip used to attach a towel to a golf club, (e.g., a putter). The clip has an opening to attach to the golf club, and an opening to attach to the towel. The clip may be mechanically attached to the club, or may use magnets. The towel may be permanently attached to the clip or may be removable. Methods for attaching a towel to a golf club and manufacturing the clip are also provided.
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BACKGROUND OF THE INVENTION
The present invention relates to connecting electrical wires with twist-on type connectors; and more particularly, to tools for fastening such connectors.
The ends of two or more wires of an electrical circuit are often connected together using a twist-on type wire connector. These connectors are available in a variety of sizes and shapes and commonly have a conical shaped body of insulating material, such as plastic, with an opening at the larger end. The opening communicates with a tapered aperture which has helical threads cut in the interior surface of the body. The fastening operation is performed by inserting the stripped ends of two or more wires into the open end and rotating the connector so that the threads screw onto and twist the wires together to form an electrical coupling. An improved connector has a tapered metal spring inserted into the aperture of the insulating body. The spring engages the bare wires and aids in providing a conductive path there between.
Twist-on type wire connectors frequently are used by electricians to connect two or more wires in a junction box within a building. In this application, electricians typically twist on the connectors by hand, although manual tools, such as a hexagonal socket wrench or a nut driver, can be used. These connectors also are employed in a variety of electrical appliances. For example, connections between the wires of a ballast in a fluorescent lighting fixture and the electrical supply cord are made in this manner. In a factory, the wire connectors often are attached using a pneumatically or electrically powered nut driver because of the high volume assembly at a fixed location. These power tools have a socket specifically designed to engage the body of the connector.
A fastening tool, especially an power-driven one, easily can apply an excessive amount of torque to the connector, thus damaging either the wires or the connector. If cracks in the connector are undetected, a short circuit could occur at the connection.
One solution to this problem was to limit the torque with a clutch mechanism between the tool motor and the socket. However, torque limiting devices add additional expense, size and weight to the tool, and require adjustment to the optimum level for each specific wiring application.
SUMMARY OF THE INVENTION
A general object of the present invention is to provide a manual or power driven fastening tool for a twist-on wire connector.
Another object is to provide a wire connector fastening tool which self-limits the amount of torque that can be applied to the connector during the fastening operation.
These and other objectives are fulfilled by a system for joining ends of electrical wires to a predefined torque level, which comprises a twist-on connector and a tool socket specifically designed to cooperate in limiting the amount of torque that the socket is able to apply to the connector. The connector includes a hollow body with an open end in which to receive the wires, a closed end and an outer surface extending between the open and closed ends. At least a portion of the outer surface has elements which form a cross section with a polygonal shape. For example, that portion of the body has side surfaces meeting at outside corners to form a hexagonal cross section.
The tool socket includes a coupling by which torque is applied to the tool socket by a driver. An aperture is provided in the tool socket to removably receive the closed end of the connector with side walls of the aperture engaging the portion of the connector's outer surface. The aperture is significantly larger in cross section than the connector so that a gap exists between the side walls and the outer surface. For example, the aperture may have a polygonal cross section with portions of the side walls between the polygon corners being directed away from the connector to form the gap. The gap results in the transfer of torque between the socket and the connector being concentrated at the outside corners of the connector. This torque concentration causes the elements of the connector, such as the outside corners of the polygon, to deform when the tool socket applies greater than the predefined torque level to the connector. After that deformation, the socket turns freely about the connector inhibiting additional torque from being applied.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a twist-on wire connector of a type which can be used with the present invention;
FIG. 2 is an axial cross-sectional view through the wire connector with a fastening socket attached thereto;
FIG. 3 is a transverse cross-sectional view along line 3 — 3 in FIG. 2 through the wire connector and the fastening socket assembly;
FIG. 4 is a transverse cross-sectional view through the wire connector and the fastening socket after an excessive torque has been applied;
FIG. 5 is a transverse cross-sectional through the wire connector and a second embodiment of a fastening socket according to the present invention;
FIG. 6 is a transverse cross-sectional through the wire connector and a third embodiment of a fastening socket according to the present invention; and
FIG. 7 is an axial cross-sectional view through the wire connector with another type of fastening socket attached thereto.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a twist-on wire connector 10 is formed of a hollow body 12 having a general shape of a truncated cone. The body 12 preferably is formed of molded plastic and has an open end 14 which tapers to a smaller diameter closed end 15 . As the outer surface of the body 12 tapers toward the closed end 15 , a transition occurs to six flat surfaces 16 . These flat surfaces 16 define a portion 17 of the body that has an equilateral hexagonal cross-section for engagement by a wrench or socket for fastening the connector 10 . Although the exemplary wire connector 10 has a hexagonal portion 17 various numbers of flat surfaces 16 may be provided to form a body portion with different polygonal shapes for tool engagement. Each flat surface 16 terminates at an edge 18 near the closed end 15 and a conical tip extends from those edges at the closed end.
The wire connector 10 also includes a pair of wings 20 which project radially from the body adjacent open end 14 . The radially inner portion of the wings 20 provide exterior longitudinal reinforcement thereby preventing the body 12 from collapsing. The wire connector 10 is fastened onto wires by turning it in the clockwise direction in the orientation illustrated. The curved surface of each wing 20 has grooves which enable the fingers of a user to grip the wire connector during the turning operation.
With reference to FIG. 2, the open end 14 of the wire connector has a circular aperture 22 extending axially into the body 12 and terminating a short distance from the closed end 15 . The aperture 22 tapers in a narrowing manner reaching a shoulder 24 approximately one-third the depth of the aperture. The shoulder 24 defines an outer portion 26 of the aperture 22 and a smaller diameter inner portion 28 . A tapered coil spring 30 made of electrically conductive metal is wedged into the smaller inner portion 28 .
In use, the stripped ends of two or more wires are inserted into the aperture 22 at the open end 14 of the connector 10 . The closed end 15 of the connector then is placed into a hexagonal socket 32 attached to a square shaft 34 of an electrically or pneumatically powered driver or a manual driver. The power tool then is activated to rotate connector 10 which causes the threaded interior of the aperture 22 to screw onto the stripped ends of the wires twistings the wires together. When the wires have been twisted sufficiently to assure a good electrical connection, the connector 10 is removed from the socket 32 . The wire connector remains on the ends of the wires providing electrical insulation for the connection.
In the United States, the Underwriters Laboratory has specified optimum torque levels for attaching different numbers and sizes of electrical wires. Insufficient torque can result in a loose connection which is susceptible to over-heating or disconnection, while application of excessive torque can damage the wires or the connector.
As previously noted, electrically or pneumatically powered tools can apply an excessive amount of torque to the connector and break the connector or the wires being fastened. As a consequence, the combination of the wire connector 10 and the tool socket 32 is specifically designed to cooperate and prevent an excessive amount of torque from being applied. That design results in the sharply angled outside corners 38 of the hexagonal connector portion 17 rounding at a predefined torque level allowing the socket 32 to rotate freely about the connector body 12 . Thereafter, torque is not transferred to the connector 10 thus limiting the tool to fastening the wire connector to no greater than the desired torque limit. The yielding of the corners 38 on the connector body 12 not only prevents excessive amount of torque from being applied, but also ensures that the predefined torque level is applied as the corners 38 do not yield until that level has been reached.
With reference to FIGS. 2 and 3, the tool socket 32 has a hexagonal cross section aperture 36 within which the closed end 15 of the connector 10 is removably received. The socket aperture 36 is larger than the cross-sectional dimensions of the mating portion of the connector 10 thus producing a loose fit as is particularly evident in FIG. 3 . As is apparent in this figure, the torque exerted on the connector 10 by the socket 32 is concentrated at the outside corners 38 of the hexagonal portion 17 of the connector. In conventional fastening operations, it is desirable to have as tight a fit as possible between the tool socket and the object between fastening, in this case the connector 10 . That tight fit assures the torque will be distributed through a relatively large surface contact area between the components and prevents the tool socket from turning around the object. However, the present concept intentionally provides less than the normally desired tight fit.
The relatively loose fit between these components is sufficient to for the tool socket 32 to rotate the connector 10 so as to properly couple wires placed within the connector for fastening. When the predefined torque level for the connection is reached, the angled corners 38 of the hexagonal portion 17 of the plastic connector 10 become rounded as depicted in FIG. 4 . That predefined torque level is too intense for the relatively small amount of plastic material at the connector corners 38 to withstand without deforming. The deformation continues until the socket 32 is able to rotate freely about the connector 10 at which time transfer of torque to the connector ceases. The difference in cross sectional sizes of the connector 10 and the socket aperture 22 and depth D (FIG. 2) that the connector extends onto the socket aperture determine the area of contact between those components and thus the torque magnitude that must be applied before rounding occurs. The strength of the plastic body 12 also is a factor in determining the torque level at which corner rounding occurs. These factors enable the socket-connector combination to be intentionally designed so that the tool socket 32 can not exert more that the predefined torque level on wire connector 10 .
FIG. 5 illustrates an alternative design of a tool socket 40 which has an aperture that is formed by six concave curved side walls 42 . The radius of each side wall is more than twice the distance to the center axis 41 of the socket, for example. Adjacent side walls meet at a line that is parallel to the center axis thus defining an inside corner within which a corner 38 of the connector is received. Because of the curving nature of the side walls, the distance from the center axis 41 to the side walls is greatest at each inside corner and decreases going from an inside corner toward a midpoint 44 along each sidewall 42 . Therefore, the hexagonal cross-section portion 17 of the connector 10 is captivated in the aperture so that rotation of the tool socket 40 by the square shaft 34 of the driver will produce rotation of the connector. However, the torque being transferred to from the socket to the connector is concentrated at each outside corner 38 which engages an inside corner of the socket aperture. Thus when the predefined torque limit for this type of connector is exceeded, the corners 38 round allowing the socket to turn freely about the connector. The radius of the side wall curvature defines the area of surface contact between the tool socket 40 and the connector 10 , and thus the torque limit at which rounding occurs.
FIG. 6 illustrates a variation of the socket 40 in FIG. 5 . In the third embodiment, socket 50 has an aperture 52 with a dodecagon cross section which by definition has twelve side surfaces and twelve inside corners 54 . The six outside corners 38 of the hexagonal cross sectional portion 17 of the connector 10 nest within six of the inside corners 54 with an open inside corner of socket 50 between each inside corner 54 that is engaged by a connector corner 38 . The twelve side surfaces of the socket aperture 52 angle away from the six exterior flat surfaces 16 of the connector thus concentrating the applied torque to relatively small surface areas of the connector adjacent to corners 38 . This causes the sharply angled connector corners 38 to round when the predefined torque limit is exceeded.
Another version of a tool socket 60 according to the present invention is shown in FIG. 7 . This socket 60 has a hexagonal cross section aperture 62 with a relatively large cross section portion 64 within which the closed end 15 of the connector 10 is removably received. The aperture 62 narrows at a shoulder 66 against which abut the edges 18 of the connector flat surfaces 16 . The shoulder 66 defines the depth to which the connector 10 is able to enter the aperture 62 and thus the amount of surface area in which the connector contacts the socket. The torque transferred to the connector 66 and thus the amount of surface area in which the connector contacts the socket. The torque transferred to the connector from the socket during the fastening operation in concentrated in that contact surface area. Therefore by selectively controlling that area with the depth of shoulder 66 , the torque level at which the corners of the hexagonal portion of the connector become rounded can be set to the appropriate magnitude for a given fastening operation.
In an variation of the socket 60 in FIG. 7, the portion 64 of aperture 62 is so large in comparison to the cross section of the connector 10 that the socket does not engage the connector flat surfaces 16 or the corners at the meeting point of adjacent flat surfaces. Instead the shoulder 66 has a curved projection which extends into the notches 19 in the edges 18 of the flat surfaces 16 . Thus torque is transferred from the socket to the connector through the surfaces of the notches 19 . The depth of the notches defines the amount of surface area through which the torque is transferred. By defining that surface area, a limit to the amount of torque that may be applied to the connector can be established. Application of a greater magnitude of torque causes the walls of the notches to deform which results in the socket turning on the end of the connector without further torque transfer.
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Ends of several electrical wires are joined by a connector which is twisted onto the wire to a predefined torque level by using a unique tool socket. The connector has a body with closed end and an open end for receiving the electrical wires. At least a portion of the hollow body has an equilateral polygonal cross section shape formed by side surfaces which meet at corner sections. The tool socket includes a coupling through which torque is applied and has an aperture for receiving the connector. The aperture has a cross-sectional shape such that the tool socket engages only the connector corner sections and a space exists between the connector side surfaces and the socket. That engagement concentrates torque applied by the tool socket to the connector which causes the corner sections to round upon application of more than the predefined torque level, thus preventing excessive torque from being applied to the connector and the wires.
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FIELD OF THE INVENTION
[0001] The invention relates to graft polymers and more particularly to a process for their preparation.
SUMMARY OF THE INVENTION
[0002] A process of producing a graft polymer of the ABS type by the emulsion method is disclosed. In the process wherein 5 to 95% by weight of a monomer mixture that contains A) 50 to 99 parts by weight of at least one vinyl aromatic compound and B) 1 to 50 parts by weight of at least one copolymer is polymerized in the presence of C) 95 to 5% by weight of one or more graft substrates having a glass transition temperature <10° C., the improvement includes monitoring continuously in the course of the reaction the Raman spectra of the reaction mixture, determining deviations from the specified desired course of the reaction and making corresponding adjustments.
BACKGROUND OF THE INVENTION
[0003] Graft polymers of the ABS type are two-phase plastics materials made of a thermoplastic copolymer of resin-forming monomers, for example, styrene and acrylonitrile, and at least one graft polymer, which is obtainable by polymerization of one or more resin-forming monomers, for example, the above-mentioned monomers, in the presence of rubber, for example, butadiene homopolymer or copolymer as the graft substrate.
[0004] The term graft polymers of the ABS type in the present context includes compositions of the type in which these constituents are completely or partially replaced by analogous constituents.
[0005] Examples of analogous constituents for styrene are, for example, α-methyl styrene, chlorostyrene, vinyl toluene, p-methyl styrene or tert.-butyl styrene. Examples of analogous constituents for acrylonitrile are, for example, methacrylonitrile, ethacrylonitrile, methyl methacrylate or N-phenylmaleinimide. A similar constituent for butadiene is, for example, isoprene.
[0006] Graft polymers of the ABS type and methods for their production are known in principle (see, for example, Ullmann's Encyclopaedia of Industrial Chemistry, Vol. A21, VCH Weinheim, 1992). These graft polymers may be produced, for example, by polymerization in solution or by the so-called mass method and by polymerization in the presence of water (emulsion polymerization, suspension polymerization).
[0007] In the methods known from the prior art, attempts are generally made to achieve a course of the reaction which is as uniform as possible with as many process parameters as possible (such as, for example, temperature, monomer supply profile, pressure etc.) being kept as constant as possible, and thereby to obtain products with advantageous properties which are as reproducible as possible.
[0008] On an industrial scale, however, maintaining the process parameters is no guarantee of the absolute reproducibility of the method and of obtaining products with specified properties. The reaction rate profile can be influenced by many factors, such as, for example, impurities contained in the reactants, variations in the stirring speed, in the surface condition of the reaction vessel, variations in the particle size etc.
[0009] These causes can lead both to depletion and also to enrichment of the reaction mixture in one or more monomers during graft polymerization.
[0010] Apart from reductions in the product quality, a deviation of this type in the concentration of one or more monomers from the conventional concentration at a given point in time can, however, also lead to problems from safety aspects (for example risk of an uncontrolled course of the reaction such as, for example, “passing through” of the reaction).
DESCRIPTION OF THE FIGURES
[0011] [0011]FIG. 1 shows the course of the reaction, detected by Raman Spectroscopy, described in Example 1.
[0012] [0012]FIG. 2 shows the course of the reaction, detected by Raman Spectroscopy, described in Example 2.
[0013] [0013]FIG. 3 shows the course of the reaction, detected by Raman Spectroscopy, described in Example 3.
[0014] [0014]FIG. 4 shows the morphology of the product of Example 1.
[0015] [0015]FIG. 5 shows the morphology of the product of Example 2.
[0016] [0016]FIG. 6 shows the morphology of the product of Example 3.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The subject of the present invention is a method for improved production of graft polymers of the ABS type by the emulsion method, wherein
[0018] 5 to 95, preferably 30 to 90 percent by weight of a monomer mixture containing
[0019] A) 50 to 99% by weight, preferably 50 to 70% by weight of at least one vinyl aromatic monomer and
[0020] B) 1 to 50% by weight, preferably 30 to 50% by weight of at least one other monomer the % being relative to the total weight of (A) and (B),
[0021] are polymerized in the presence of
[0022] C) 95 to 5, preferably 70 to 10 percent by weight of one or more rubber graft substrate with glass transition temperatures of <10° C., preferably <0° C., particularly preferably <−20° C.
[0023] the percents being relative to the total weight of the mixture and (C), characterized in that the course of the reaction is continuously monitored by the recording of Raman spectra of the reaction mixture and corrective measures are introduced in the event of deviations from the desired monomer concentrations.
[0024] Corrective measures may include, for example, increasing or decreasing the feed rate of one or all monomers and/or the initiator
[0025] Suitable vinyl aromatic compounds A) are, for example, styrene, α-methyl styrene and vinyl aromatic compounds substituted in the nucleus such as, for example, p-methyl styrene and p-chlorostyrene and mixtures of these monomers.
[0026] Suitable comonomers B) are, for example, vinyl cyanides (unsaturated nitriles) such as acryloritrile and methacrylonitrile and/or (meth)acrylic acid-(C 1 -C 8 )-alkyl ester (such as methyl methacrylate, n-butyl acrylate, t-butyl acrylate) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenylmaleinimide).
[0027] Preferred monomer A) is at least one member selected from the group consisting of styrene and α-methyl styrene, preferred monomer B) is at least one member selected from the group consisting of acrylonitrile, N-phenylmaleinimide and methyl methacrylate.
[0028] Particularly preferred monomer A) is styrene and the preferred B) is acrylonitrile.
[0029] Preferred graft substrates C) include diene rubbers EP(D)M rubbers, in other words those based on ethylene/propylene and optionally diene, acrylate, polyurethane, silicone, chloroprene and ethylene/vinyl acetate rubbers and mixtures thereof.
[0030] Suitable acrylate rubbers are preferably polymers made of acrylic acid alkyl esters, optionally with up to 40% by weight, based on C) of other polymerizable, ethylenically unsaturated monomers. Preferred polymerizable acrylic acid esters include C 1 -C 8 -alkyl esters, for example, methyl, ethyl, butyl, n-octyl and 2-ethylhexyl ester; haloalkyl esters, preferably halogen-C 1 -C 8 -alkyl esters, such as chloroethyl acrylate and mixtures of these monomers.
[0031] Preferred further polymerizable, ethylenically unsaturated monomers which, apart from the acrylic acid esters, may optionally serve to produce the graft substrate C) are, for example, acrylonitrile, styrene, α-methyl styrene, acrylamides, vinyl-C 1 -C 6 -alkyl ethers, methyl methacrylate, butadiene. Preferred rubbers as the graft substrate C are emulsion polymers which have a gel content of at least 30% by weight.
[0032] Monomers with more than one polymerizable double bond may be copolymerized in the production of acrylate rubbers. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids with 3 to 8 carbon atoms and unsaturated monovalent alcohols with 3 to 12 carbon atoms, or unsaturated polyols with 2 to 4 OH groups and 2 to 20 carbon atoms such as ethylene glycol dimethacrylate, allyl methacrylate; heterocyclic compounds having a plurality of unsaturations, such as trivinyl and triallyl cyanurate; polyfunctional vinyl compounds, such as divinyl and trivinyl benzenes; but also triallyl phosphate and diallyl phthalate.
[0033] Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds which have at least three ethylenically unsaturated groups.
[0034] Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine, triallyl benzenes. The quantity of the crosslinking monomers is preferably 0.02 to 5, in particular 0.05 to 2% by weight, based on the graft substrate C.
[0035] In cyclic crosslinking monomers with at least three ethylenically unsaturated groups, it is advantageous to limit the quantity to below 1% by weight of the graft substrate C.
[0036] Further suitable graft substrates according to C) are silicone rubbers with graft-active points, such as are described in DE-A 37 04 657, DE-A 37 04 655, DE-A 36 31 540 and DE-A 36 31 539.
[0037] Preferred graft substrates C) are diene rubbers (for example based on butadiene, isoprene etc.) or mixtures of diene rubbers or copolymers of diene rubbers or mixtures thereof with further copolymerizable monomers (for example such as are included in A and B), with the proviso, that the glass transition temperature for component C is below 10° C., preferably <0° C., particularly preferably <−100° C.
[0038] Particularly preferred as graft substrate C) is pure polybutadiene rubber.
[0039] The gel content of the graft substrate C) is at least 30% by weight, preferably at least 40% by weight. The gel content of the graft substrate C) is determined at 25° C. in toluene (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I und II, Georg Thieme-Verlag, Stuttgart 1977).
[0040] The graft substrate C generally has a median particle size (d 50 value) of 0.05 to 10 μm, preferably 0.1 to 5 μm, particularly preferably 0.2 to 1 μm.
[0041] The median particle size d 50 is the diameter, above and below which 50% by weight of the particles lie, in each case. It can be determined by means of ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972), 782-796).
[0042] The graft polymers are produced by radical emulsion polymerization.
[0043] Graft polymerization may be carried out by any addition method. It is preferably carried out such that the monomer mixture containing A) and B) is continuously added to the graft substrate C) and polymerized.
[0044] Specific monomer/rubber ratios are preferably maintained. When the method for producing graft polymers is carried out according to the invention, the monomers may be added uniformly to the rubber latex over a defined time period or using any metering gradients, for example, in such a way that within the first half of the total monitoring adding time, 55 to 90% by weight, preferably 60 to 80% by weight and particularly preferably 65 to 75% by weight of the total monomers to be used in the graft polymerization are added; the remaining monomer portion is added within the second half of the total monomer adding time.
[0045] Conventional anionic emulsifiers may be used as emulsifiers, such as alkyl sulphates, alkyl sulphonates, aralkyl sulphonates, soaps of saturated or unsaturated fatty acids and alkaline, disproportionate or hydrogenated abietic or tall oil acids. Emulsifiers with carboxyl groups can theoretically also be used (for example salts of C 10 -C 18 -fatty acids, disproportionate abietic acid and emulsifiers according to DE-A 36 39 904 and DE-A 39 13 509).
[0046] In addition, molecular weight regulators may be used in the graft polymerization, preferably in quantities from 0.01 to 2% by weight, particularly preferably in quantities from 0.05 to 1% by weight (based on the total monomer quantity, in each case). Suitable molecular weight regulators are, for example, alkyl mercaptans such as n-dodecylmercaptan, t-dodecyl-mercaptan; dimeric α-methyl styrene; terpinols.
[0047] Possible initiators are inorganic and organic peroxides, for example, H 2 O 2 , di-tert.-butyl peroxide, cumolhydroperoxide, dicyclohexyl percarbonate, tert.-butyl hydroperoxide, p-menthane hydroperoxide, azoinitiators such as azobisiso-butyronitrile, inorganic persalts such as ammonium, sodium or potassium persulphate, potassium perphosphate, sodium perborate and redox systems.
[0048] Redox systems generally include an organic oxidising agent and a reducing agent, wherein heavy metal ions may additionally be present in the reaction medium (see Houben-Weyl, Methoden der Organischen Chemie, Vol. 14/1, page 263 to 297).
[0049] The polymerization temperature is generally between 25° C. and 160° C., preferably between 40° C. and 90° C.
[0050] The work can then take place with conventional temperature control, for example, isothermally; the graft polymerization is preferably carried out in such a way, however, that the temperature difference between the beginning and the end of the reaction is at least 10° C., preferably at least 15° C. and particularly preferably at least 20° C.
[0051] Particularly preferred graft copolymers obtained by the method according to the invention are ABS, as described, for example, in DE-A 20 35 390 (=U.S. Pat. No. 3,644,574) or in DE-A 22 48 242 (=GB-A 1 409 275) or in Ullmanns Enzyklopadie der Technischen Chemie, Vol. 19 (1980), page 280 ff.
[0052] Particularly suitable graft polymers are also ABS polymers which are produced by persulphate initiation or by redox initiation with an initiator system made of organic hydroperoxide and ascorbic acid according to U.S. Pat. No. 4,937,285.
[0053] In the production of graft polymers of the ABS type according to the method of the invention, the grafting reaction is advantageously discontinued at a monomer conversion of 95% to 100%.
[0054] In a preferred embodiment, the content of unpolymerized vinyl aromatic component A) in the reaction mixture at any point in time is less than 12% by weight, preferably less than 10% by weight and particularly preferably less than 9% by weight.
[0055] To ensure that the content of unpolymerized vinyl aromatic component A) does not exceed said maximum values (or the content of another monomer is outside the desired range) these monomer concentrations are followed inline or online by means of Raman spectroscopy in a preferred embodiment of the invention. In the scope of the present invention online denotes a mode of operation in which part of the reaction mixture is branched off, for example, by a side loop from the reaction vessel, measured and then returned to the reaction mixture. Inline denotes that the measurement takes place directly in the reaction vessel.
[0056] For this purpose, Raman spectra of the reactor content are recorded at short time intervals during graft polymerization in the range of ν min =−4000 cm −1 (anti-Stokes range) and ν max =4000 cm −1 (Stokes range), preferably ν min =500 cm −1 and the ν max =2,500 cm −1 , particularly preferably ν min =750 cm −1 and ν max =1,800 cm −1 . The frequency of the recorded measurements depends on speed of process data progress. Generally the recordings are taken at intervals of 1 second to 30 minutes, preferably 10 seconds to 10 minutes.
[0057] Any commercially available Raman spectrometer systems, preferably Fourier transformation and dispersive Raman spectrometers, are suitable for recording the spectra.
[0058] In a preferred embodiment, the observed monomer concentrations are calculated from the measured Raman spectra by the method of weighted subtraction as described below.
[0059] The factors f i are calculated from the previously measured Raman spectra stored in digitized form in a data processing unit, I PB (ν) of polybutadiene (PB), I PS (ν) of polystyrene (PS), I PAN (V) of polyacrylonitrile (PAN), I STY (ν) of styrene (STY) and I ACN (V) of acrylonitrile (ACN) and the actual spectrum I(ν) of the reactor content from the condition
ν max Σ{I K (ν)−[ f PB *I PB (ν)+ f PS *I PS (ν)+ f PAN *I PAN (ν)+ f STY *I STY (ν)+ f ACN *I ACN (ν)+ f k ]} 2 ν min =minimum
[0060] wherein summation is carried out via all data points of the spectra I i (ν) digitized in the same form.
[0061] From the factors f i are calculated the quotients
Q PS =f PS /f PB , Q PAN =f PAN /f PB , Q STY =f STY /f PB and Q ACN =f ACN /f PB
[0062] and with the previously determined calibration factors K, the ratios W of:
[0063] polystyrene to polybutadiene: W PS =K PS *Q PS
[0064] polyacrylonitrile to polybutadiene: W PAN =K PAN *Q PAN
[0065] styrene to polybutadiene: K STY *Q STY
[0066] acrylonitrile to polybutadiene: W ACN =K ACN *Q ACN
[0067] are calculated and therefrom according to:
M PS =W PS *M PB , M PAN =W PAN *M PB , M STY =W STY *M PB and M ACN =W ACN *M PB
[0068] the absolute quantities of polystyrene M PS , polyacrylonitrile M PAN , styrene M STY and acrylonitrile M ACN are determined in the reactor. The variable M PB is constant during the reaction. The quantity of polybutadiene fed into the reactor is detected by means of conventional quantity measurement.
[0069] In a particularly preferred embodiment, the factors K PS , K PAN , K STY and K ACN are determined, in that the Raman spectra I k (ν) are recorded from mixtures with known ratios. The factors f i are calculated (weighted subtraction) from the condition
ν max Σ{I K (ν)−[ f PB *I PB (ν)+ f PS *I PS (ν)+ f PAN *I PAN (ν)+ f STY *I STY (ν)+ f ACN *I ACN (ν)+ f k ]} 2 ν min =minimum
[0070] the quotients
Q PS =f PS /f PB , Q PAN =f PAN /f PB , Q STY =f STY /f PB and Q ACN =f ACN /f PB
[0071] are determined therefrom, the weight parts W
[0072] ti W PS =M PS /M PB , M PAN =W PAN /M PB , W STY =M STY /M PB and W ACN =M ACN /M PB
[0073] are calculated from the known quantities M and the calibration factors K are calculated according to the equations
K PS =W PS /Q PS , K PAN =W PAN /Q PAN , K STY =W STY /Q STY and K ACN =W ACN /Q ACN .
[0074] The method according to the invention is distinguished by improved reaction reliability throughout the course of graft polymerization.
[0075] The graft polymers obtained by the method according to the invention are distinguished by very good mechanical properties (such as, for example, good impact strength) with very high reproducibility.
[0076] These graft polymers are suitable, preferably after mixing with at least one rubber-free resin component, for producing moldings, for example, domestic appliances, motor vehicle components, office machines, telephones, radio and television set housings, furniture, tubes, leisure articles or toys.
[0077] Copolymers of styrene and acrylonitrile with a weight ratio (styrene/acrylonitrile) of 95:5 to 50:50 are preferably used as rubber-free resin components, styrene and/or acrylonitrile being completely or partially replaceable by α-methyl styrene, methyl methacrylate or N-phenyl maleinimide. Particularly preferred are copolymers of which the contents of incorporated acrylonitrile units are below 30% by weight.
[0078] These copolymers preferably have weight average molecular weights M w of 20,000 to 200,000 and intrinsic viscosities [η] of 20 to 110 ml/g (measured in dimethyl formamide at 25° C.).
[0079] Details on producing these copolymers are, for example, described in DE-A 24 20 358 and DE-A 27 24 360 (U.S. Pat. Nos. 4,009,226 and 4,181,788 incorporated herein by reference). Vinyl resins produced by mass or solution polymerization have proved particularly expedient. The copolymers may be added alone or in any mixture.
[0080] Apart from thermoplastic resins made up of vinyl monomers the use of polycondensates, for example, aromatic polycarbonates, aromatic polyester carbonates, polyesters, polyamides as rubber-free resin components in the molding compounds according to the invention is also possible.
[0081] The invention will be illustrated hereinafter by examples, but without restriction to these examples.
EXAMPLES
Example 1
[0082] (According to the invention, simulation of an interruption in the initiator metering with continuous monitoring by recording Raman spectra and corrective-measures in the event of deviations from the desired behavior) 42 parts by weight of a monomer mixture of styrene and acrylonitrile (weight ratio 67.5:32.5) and 0.15 parts by weight tert.-dodecylmercaptan are metered within 6 h at 62° C. to 58 parts by weight (calculated as solids) of a polybutadiene latex (solids content about 30% by weight, median particle size (d 50 ) about 350 nm).
[0083] Simultaneously, 16.2 parts by weight of a 7.4% aqueous emulsifier solution (sodium salt of Desinate 731® from Abieta Chemie, Gersthofen, Germany) are added. The course of the reaction is continuously followed by recording Raman spectra. Once the Raman spectra showed an increase in monomeric styrene in the reaction mixture to above 8% by weight (based on polybutadiene), the monomer supply was stopped and 0.25 parts by weight potassium persulphate (in the form of 2.5% aqueous solution) added. After a drop in the monomeric styrene content in the reaction mixture to below 6% by weight (based on polybutadiene) the monomer metering is continued and a 3-hour metering of 0.25 parts by weight potassium sulphate started (in the form of a 2.5% aqueous solution).
[0084] The total reaction time is 9 h (6 h reaction time+3 h post-stirring time at 70° C.), the course of the reaction (detected by Raman spectroscopy) is shown in FIG. 1.
Example 2
[0085] (Comparative test, simulation of an interruption in the initiator metering without continuous monitoring by recording Raman spectra and without corrective measures in the event of deviations from the desired behavior).
[0086] Example 1 is repeated, the increase in the monomeric styrene in the reaction mixture to 20% by weight (based on polybutadiene) taking place before polymerization is triggered by addition of potassium persulphate solution. The other reaction conditions remain unchanged. The course of the reaction (determined by Raman spectroscopy) is illustrated in FIG. 2.
Example 3
[0087] (Comparative test, simulation of a course of the reaction without interruption in the initiator metering, reference test for desired course of the reaction). Example 1 is repeated, metering of the potassium persulphate solution taking place from the start simultaneously with the monomer metering. The other reaction conditions remain unchanged.
[0088] The course of the reaction (determined by Raman spectroscopy) is shown in FIG. 3.
[0089] Investigation and Checking of the Products from Examples 1 to 3
[0090] Latex samples are removed for characterization by electron microscope and measured after contrasting with osmium tetroxide. The morphologies shown in FIGS. 4, 5 and 6 show that a morphology is only obtained when monitoring the course of the reaction by Raman spectroscopy and carrying out corrective measures (FIG. 4, product from Example 1, uniform graft shell), which corresponds to that of the reference test (FIG. 6, product from Example 3). In the case of no monitoring and occurrence of faulty metering a product is produced with a non-uniform graft shell (FIG. 5, product from Example 2).
[0091] The graft rubber latexes resulting from Examples 1 to 3 were precipitated by addition of a phenolic antioxidant with a magnesium sulphate/acetic acid mixture in each case, whereupon the resultant graft powder was washed with water and dried in the drying chamber at 70° C.
[0092] Using this graft rubber powder, mixtures given in Table 1 were produced in an internal kneader and processed by injection molding to form test specimens. In the process, a product with a polybutadiene content of 50% by weight and a grafted-on styrene/acrylonitrile copolymer quantity of 50% by weight (styrene:acrylonitrile ratio 73:27) with a median particle diameter, d 50 , of about 120 nm was used as the fine-particle graft rubber.
[0093] A product with a weight average molecular weight, M W , of about 85,000 (styrene:acrylonitrile ratio 72:28) was used as SAN resin.
[0094] All the compositions contained 2 parts by weight ethylenediamine bisstearoylamide and 0.15 parts by weight of a silicone oil as additives.
[0095] Determination of the impact strength at ambient temperature (a k RT , unit: kJ/m 2 ) took place to ISO 180/1A, the thermoplastic pourability(MVI, unit: cm 3 /10 min) was determined to DIN 53 735 U.
[0096] The test values also given in Table 1 show that, product properties which are very similar to the reference material are obtained when using the graft rubber produced according to the invention.
TABLE 1 Compositions and test data on the molding compositions investigated Graft rubber from Graft rubber from Graft rubber from Fine-particle graft Example 1 Example 2 Example 3 rubber SAN resin a k RT MVR [parts by weight] [parts by weight] [parts by weight] [parts by weight] [parts by weight (kJ/m 2 ) (cm 3 /10 min) 18 — — 12 70 16.6 35.4 — 18 — 12 70 14.9 34.5 — — 18 12 70 16.0 36.3
[0097] Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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A process of producing a graft polymer of the ABS type by the emulsion method is disclosed. In the process wherein 5 to 95% by weight of a monomer mixture that contains A) 50 to 99 parts by weight of at least one vinyl aromatic compound and B) 1 to 50 parts by weight of at least one copolymer is polymerized in the presence of C) 95 to 5% by weight of one or more graft substrates having a glass transition temperature <10° C., the improvement includes monitoring continuously in the course of the reaction the Raman spectra of the reaction mixture, determining deviations from the specified desired course of the reaction and making corresponding adjustments.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application incorporates by reference U.S. patent application Ser. No. 10/337,896, now U.S. Pat. No. 6,774,098, filed Oct. 10, 2002, entitled “Methods For Removing Stains From Fabrics Using Tetrapotassium EDTA,” which claims priority to U.S. Provisional Application Ser. No. 60/423,978, filed Nov. 6, 2002, entitled “A Subclass of Aqueous, Hard Surface Cleaners Used in A New and Unobvious Soft Surface Cleaning Application.” The present application also incorporates by reference U.S. patent application Ser. No. 10/612,016, filed Jul. 3, 2003, and U.S. patent application Ser. No. 10/373,787, filed Feb. 27, 2003, both of which are entitled “Methods and Equipment for Removing Stains from Fabrics.”
TECHNICAL FIELD
[0002] This invention relates to a fabric having a pattern of fades and a methodology for their creation. The fades are made by exposing selected areas of the fabric to a hypochlorite salt-containing composition.
BACKGROUND
[0003] Fades on garments and other apparel are popular among all age groups, both female and male. Due to its popularity to the consumers, jean manufacturers have developed various methods to produce fades on jeans or denims to achieve a faded look. One method employs washing denims with a cellulase enzyme to release the denim's color, which produces light or white areas and lightens the dark areas (see U.S. Pat. Nos. 4,832,864, 4,912,056, 5,006,126 and 5,122,159). However, the use of enzymes to create a faded appearance can also at the same time be used to desize or shrink a fabric or garment. Thus, extra care and precision are needed if one were to employ an enzymatic approach.
[0004] Another method, as disclosed in U.S. Pat. No. 4,740,213, uses pumice stones impregnated with fluid having powerful bleaching properties to create a random faded effect on the fabric when the stones and fabric are tossed together, such as in a dryer or other tumbling apparatus. However, this process, commonly known as “stone-washing,” produces uneven faded patches that vary in color shades and intensity, which, due to the random admixture, spread out in a non-uniform manner over the entire fabric being treated. These whole-fabric techniques do not permit treating specific areas of the fabric individually. Moreover, the use of strong bleaching agents is inherently harmful to the fabric.
[0005] Another technique to produce fades on fabric employs lasers. A laser method to mark and fade textiles, as disclosed in U.S. Pat. No. 5,567,207, involves exposing a textile or fabric to laser radiation of sufficient intensity. Such exposure photo-decomposes the coloring agent within the material without causing damage to the underlying textile or fabric. The pre-dyed material is scanned by a laser beam to produce uniform fading and patterns of photo-bleached marks on the textile material. Despite the possibility of great precision and potential for print-like art quality, this method is more expensive, time-consuming, and generally unavailable to consumers.
[0006] Unlike the above-mentioned methods, the present invention is simple, safe and readily available to consumers. The present invention can be done at home and allows the end users to selectively choose an area of the fabric where he or she wants to impart a customized and desired faded appearance, with a hand-art quality, either uniformly or non-uniformly. Additionally, there is a need for fabric having a pattern of fades thereon that can be customized by the consumers in a cost-effective manner and is a product of the consumers' artistic creation.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a fabric that comprises a pattern of fades produced by a method that includes (i) contacting a hypochlorite salt-containing composition on at least one portion of the fabric, wherein the hypochlorite salt-containing composition comprises an alkali metal hydroxide and a hypochlorite salt, and (ii) inactivating or removing the hypochlorite salt-containing composition from said at least one portion of the fabric to obtain a desired pattern of fades on the fabric. In one embodiment, the application of the hypochlorite salt-containing composition is performed at room temperature and the removal or inactivation of the hypochlorite salt-containing composition is achieved by a cold water wash.
[0008] In another embodiment, the hypochlorite salt-containing composition comprises an alkali metal hydroxide and a hypochlorite salt. In a preferred embodiment, the alkali metal hydroxide is sodium hydroxide and the hypochlorite salt is sodium hypochlorite. The weight concentration ratio of sodium hydroxide over sodium hypochlorite is no less than 1:12.5. In another embodiment, the weight concentration ratio of sodium hydroxide over sodium hypochlorite ranges from about 1:5 to about 5:1. In yet another embodiment, the weight concentration ratio of sodium hypochlorite over sodium hydroxide is about 2:1. In a further embodiment, the pH of the hypochlorite salt-containing composition is at least 11.8. It can also be, for example, at least 12, 12.5, or 13.
[0009] In yet another embodiment, the hypochlorite salt containing composition includes at least 0.2, 0.3, 0.5, 1, 2, 3 or higher weight percent of sodium hydroxide. In a non-limiting example, the concentration of sodium hydroxide ranges from 0.5-5.5 weight percent.
[0010] In a further embodiment, the hypochlorite salt is sodium hypochlorite whose concentration ranges from 0.1-11.0 weight percent or 1.0-2.5 weight percent. In a non-limiting example, the hypochlorite salt containing composition contains about 2.5% weight percent of sodium hypochlorite and 0.5. to 1.25 weight percent of sodium hydroxide. In another embodiment, the hypochlorite salt containing composition includes about 6 weight percent of sodium hypochlorite and 1.2 to 3 weight percent of sodium hydroxide. In yet another embodiment, the hypochlorite salt containing composition contains about 8 weight percent of sodium hypochlorite and 1.2 to 4 weight percent of sodium hydroxide. In still another embodiment, the hypochlorite salt containing composition includes about 11 weight percent of sodium hypochlorite and up to 5.5 weight percent of sodium hydroxide.
[0011] The hypochlorite salt-containing composition can be applied for successive intervals to produce successive faded hues. It can be applied as a liquid or a gel. In addition, it can be applied by means of a gel stick, microspray jet, fabric dye brush or any other appropriate applicators for generating artwork on a canvass. The duration of the application may depend on the formation of faded hues, as pre-determined by the end user. In a non-limiting example, the duration of application ranges from at least 1 minute to 30 minutes.
[0012] The hypochlorite salt-containing composition can be employed in various concentrations on a given fabric. The duration of application to achieve the formation of a variety of faded hues on a fabric can be standardized, such as in a commercial usage of the present invention. Instead of multiple, time-spaced passes over the fabric applying the full strength composition, one application from multiple sources of varying concentrations to achieve the desired variegated effect can be put down, thereby minimizing handling of the fabric and simplifying the production process. At the end of a predetermined treatment time, the treated fabric can be inactivated, such as by cold water immersion.
[0013] In one embodiment, the formation of the fades pattern on the fabric is dyed with another color or left as the fabric base color. It can be formed by means of free hand, template guide or machine operation. A preferred fabric is cotton and preferred garments are denim jeans or trousers.
[0014] In another embodiment, a method and a kit for the production of fabric having a pattern of fades are also provided in the present invention.
[0015] In a further embodiment, a device to manufacture the fabric having a pattern of fades is also contemplated. The device of the present invention includes a surface where the fabric is placed upon and at least one dispenser disposed adjacent to the surface. To produce a pattern of fades on the fabric, at least one dispenser relatively moves to the fabric and applies the hypochlorite salt-containing composition to the fabric. In addition, at least one dispenser may include a plurality of dispensers that relatively moves to the fabric and applies a hypochlorite salt-containing composition to the fabric. The device may further include at least one template that is placed atop the fabric. The hypochlorite salt-containing composition is applied through the template to form the pattern of fades on the fabric. The device may still further include a vat that is adjacent to the surface. After being in contact with the hypochlorite salt-containing composition, the treated fabric is inactivated, such as by cold water immersion in the vat.
[0016] Other features, objects, and advantages of the present invention are apparent in the detailed description that follows. It should be understood, however, that the detailed description, while indicating embodiments of the present invention, is given by way of illustration only, not limitation. Various changes and modifications within the scope of the invention will become apparent to those skilled in the art from the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings ( FIGS. 1-5 ) will be provided by the Office upon request and payment of the necessary fee. The drawings are provided for illustration, not limitation.
[0018] FIG. 1 is frontal view of a denim patch that has been treated with a 6% hypochlorite salt-containing composition for 1.5 to 30 minutes, pursuant to the present invention. Reference numerals 10 and 70 show dark blue and white patches, respectively;
[0019] FIG. 2 is a frontal view of a faded denim patch of a first fade artwork labeled as “The Comic;”
[0020] FIG. 3 is a frontal view of a faded denim patch of a second fade artwork labeled as the “Eye of the Hurricane;”
[0021] FIG. 4 is a frontal view of a faded denim patch showing of a third fade artwork labeled as the “Blossom and Bow;”
[0022] FIG. 5 is a frontal view of the fade artwork of FIG. 4 , wherein another dye color (red) is applied to a bleached-out section of the fabric portraying the flower blossom;
[0023] FIGS. 6A and 6B are side and top views, respectively, of a device used to produce pattern of faded hues in a fabric according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention is based on the surprising discovery that a hypochlorite salt-containing composition, which contains a metallic salt of hypochlorous acid and an appropriate amount of alkali metal, can not only be used as a cleaning composition but can also be used to non-destructively and conveniently create a pattern of fades on a fabric. The fades are formed by the application of the hypochlorite salt-containing composition on one or more selected portion(s) of the fabric. The fades action can be stopped by removal, dilution, or otherwise inactivation of the hypochlorite salt-containing composition when a desired fades formation is produced.
[0025] Without limiting the present invention to any particular mechanism, Applicant has found that alkali metal hydroxide (such as sodium hydroxide) adds significantly to the cleaning power of sodium hypochlorite to remove stains, such as menstrual fluid or underarm perspiration stains, from clothes and other soft fabric articles, while significantly increasing the compatibility of sodium hypochlorite with soft fabric, such as cotton fabric, thereby preventing sodium hypochlorite from damaging the fabric. The discovery of the hypochlorite salt-containing composition as an effective cleaning composition is disclosed in co-pending U.S. patent application Ser. Nos. 10/373,787 and 10/612,016, incorporated by reference herein.
[0026] The metallic salt of hypochlorous acid preferably is sodium hypochlorite. The alkali metal hydroxide preferably is sodium hydroxide. It should, of course, be understood that other hypochlorous salts and/or alkali metal hydroxides can also be used in the present invention.
[0027] Sodium hypochlorite (NaOCl) dissolves in water to sodium and hypochlorite ions. The hypochlorite ion is a strong oxidant which can react with numerous materials. The stability of the sodium hypochlorite composition is affected by the pH of the composition. It has been reported that sodium hypochlorite is the most stable when the pH of the composition is between 11 to 13. Such a high pH can be created by adding excess alkali metal hydroxide, such as sodium hydroxide, to the sodium hypochlorite composition. Thus, the pH of the hypochlorite salt-containing composition preferably is at least about 11.8. For instance, the pH of the hypochlorite salt-containing composition can be at least 12, 12.5 or 13. In one embodiment, the pH of the hypochlorite salt-containing composition is about 13.
[0028] The decomposition rate of the hypochlorite ion increases when the pH of the composition falls below 11. This is because of the rapid acid-catalyzed decomposition pathway of the hypochlorite ion. The rate of decomposition also increases when the pH of the composition is over 13. This is due to the increase in the ionic strength of the composition caused by the increased level of excess alkali metal hydroxide added to the composition. The present invention finds, however, that even with a high ionic strength, the sodium hypochlorite/sodium hydroxide composition is effective in imparting a faded appearance on the fabric without any significant damaging effects. In addition, Applicant has found that addition of appropriate amounts of alkali metal hydroxide to a hypochlorite composition retards the damaging effect of the hypochlorite composition on soft fabric (such as cotton fabric).
[0029] The concentration of sodium hypochlorite in the hypochlorite salt-containing composition of the present invention is preferably at least 0.1% by weight, based on the total weight of the hypochlorite salt-containing composition. For instance, the concentration of sodium hypochlorite can be at least 0.5, 1, 2, 3, 4, 5, 6, 7 or 8% by weight. In one embodiment, the concentration of sodium hypochlorite ranges from 0.1 to 11% by weight. In another embodiment, the concentration of sodium hypochlorite is about 0.5 to 5% by weight. In yet another embodiment, the concentration of sodium hypochlorite is about 1 to 2.5% by weight. In still another embodiment, the concentration of sodium hypochlorite is about 1.5 to 2% by weight.
[0030] The concentration of sodium hydroxide in the hypochlorite salt-containing composition preferably is at least 0.2% by weight, based on the total weight of the hypochlorite salt-containing composition. For instance, the concentration of sodium hydroxide can be at least about 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3, 4 or 5% by weight. In one embodiment, the concentration of sodium hydroxide ranges from about 0.5 to about 5.5% by weight. In another embodiment, the concentration of sodium hydroxide ranges from about 1 to 2% by weight. It is generally known that an appropriate amount of alkali metal hydroxide (such as sodium hydroxide) increases the stability of sodium hypochlorite in the hypochlorite salt-containing composition.
[0031] Applicant has discovered that the weight concentration ratio of sodium hydroxide over sodium hypochlorite may vary substantially without affecting the ability of the hypochlorite salt-containing composition to form pattern of fades on fabrics. Preferably, the weight concentration ratio of sodium hydroxide over sodium hypochlorite is no less than 1:12.5. For instance, the weight concentration ratio of sodium hydroxide over sodium hypochlorite can be no less than 1:10, 1:5, 1:2.5 or 1:1.
[0032] In one embodiment, the weight concentration ratio of sodium hydroxide over sodium hypochlorite can range from about 1:5 to about 5:1. In another embodiment, the weight concentration ratio of sodium hydroxide over sodium hypochlorite is about 1:3 to about 1:1. For instance, the weight concentration ratio of sodium hydroxide over sodium hypochlorite can be about 1:2.
[0033] In another embodiment, the hypochlorite salt-containing composition includes about 6 weight percent of sodium hypochlorite and 1.2 to 3 weight percent of sodium hydroxide. In another embodiment, the hypochlorite salt-containing composition includes about 2.5 weight percent of sodium hypochlorite and 0.5 to 1.25 weight percent of sodium hydroxide. In still another embodiment, the hypochlorite salt containing composition contains about 8 weight percent of sodium hypochlorite and 1.2 to 4 weight percent of sodium hydroxide. In yet another embodiment, the hypochlorite salt containing composition includes about 11 weight percent of sodium hypochlorite and up to 5.5 weight percent of sodium hydroxide.
[0034] Other ingredients or additives can be added in the hypochlorite salt-containing composition. These ingredients or additives include, for example, chelating agents, phosphorous-containing salts, surfactants, or abrasive agents. These ingredients or additives, however, are not necessary for the fading formation function of the hypochlorite salt-containing composition. In one embodiment, the hypochlorite salt-containing composition is substantially free of chelating agents, phosphorous-containing salts, surfactants, and abrasive agents.
[0035] The hypochlorite salt-containing composition can be applied for successive intervals to produce successive hues of fades. In one embodiment, the application of the hypochlorite salt-containing composition is performed at room temperature (e.g., 68-72° F. or 21-23° C.) and the inactivation process can be achieved by a cold water wash.
[0036] The composition of the present invention can be applied on the fabric as a liquid or gel by means of a fabric dye brush, gel stick, spray jet, e.g., microspray jet, or any other appropriate applicators for generating artwork on a canvass. In a non-limiting example, the duration of the application ranges from at least 1 min-30 min. In another example, an application time of less than 15 minutes produces partially bleached-out (dark) fades while an application time of approximately 30 minutes produces totally bleached-out (white) fades. In another embodiment, the faded pattern is dyed with another color or left as the fabric base color, typically white.
[0037] The fabric patterns formed by the hypochlorite salt-containing composition can be applied onto the fabric in a uniform and non-uniform faded manner to achieve a variety of effects. For example, contacting the fabric at certain duration with the hypochlorite salt-containing composition in a non-uniform manner produces an uneven faded appearance. Also, one can spot treat the pockets or certain sections of the denim jeans with the hypochlorite salt-containing composition at a certain time frame, while leaving the remainder of the fabric untreated, to produce an overall uneven or targeted faded look. Alternatively, one can evenly expose the entire fabric to a hypochlorite salt-containing composition to create a homogeneous faded appearance over the entire fabric.
[0038] In another embodiment, the present invention includes a method to produce a fabric having a pattern of faded hues. This method includes, for example, the steps of (i) contacting a hypochlorite salt-containing composition on at least one portion of the fabric, wherein the hypochlorite salt-containing composition comprises an alkali metal hydroxide. and a hypochlorite salt, and (ii) inactivating or removing the hypochlorite salt-containing composition from at least one portion of the fabric to obtain a desired pattern of fades on the fabric. The step of contacting the fabric with the hypochlorite salt-containing composition is performed at either a fixed concentration or varying concentrations of the hypochlorite salt-containing composition. The present invention can also further comprise contacting the fabric with the hypochlorite salt-containing composition by means of free hand, a template guide or machine operation.
[0039] The hypochlorite salt-containing composition of the present invention is available to consumers as a kit. The kit preferably includes a container of the hypochlorite salt-containing composition (e.g., in a spray bottle, gel stick, spray jet, e.g., a microspray jet, or any other appropriate applicators for generating artwork on a canvass), a flat fabric dye brush made of synthetic fiber, a labeled container box and an instruction sheet.
[0040] Sodium hypochlorite and sodium hydroxide can be separately stored prior to use. For instance, they can be stored in two separate compartments of a common container. The first compartment encloses a sodium hypochlorite composition, which preferably has a pH of between 11 and 13. The second compartment encloses a concentrated sodium hydroxide composition. The two compositions are mixed together upon use. An exemplary device suitable for this purpose is illustrated in U.S. Pat. No. 6,398,077, which is incorporated herein by reference. The two compositions may also, of course, be stored separately and mixed together in one of the containers or admixed into a third container.
[0041] In a further embodiment, the present invention contemplates a device for producing a pattern of fades on the fabric. The device comprises a surface where the fabric rests upon and at least one dispenser disposed adjacent to the surface. To form the pattern of fades according to the present invention, at least one dispenser relatively moves to the fabric and applies the hypochlorite salt-containing composition to the fabric. It should be understood that a plurality of dispensers that relatively moves to the fabric may be employed to apply a hypochlorite salt-containing composition to the fabric. The device may further include at least one template that is placed atop the fabric. The hypochlorite salt-containing composition is applied through the template to form the pattern of fades on the fabric. The device may still further include a vat that is adjacent to the surface. After being in contact with the hypochlorite salt-containing composition, the treated fabric is inactivated, such as by cold water immersion in the vat.
[0042] Fabrics suitable for the present invention can be made of a variety of materials, such as cotton, cotton/polyester, corduroy, rayon, canvas, linen, nylon, acrylic, flax, hemp, jute, ramie, polyester, polyamide, acrylic, polyvinyl chloride and polyolefin. A preferred fabric is cotton. In addition, the fabric can be a garment or other apparel, carpet, tote bags, curtains, towels, bed clothing, indoor or outdoor protective covers or various wall-covering fabrics to name but a few of the potential fabrics. The garment or apparel items can be a dress, work wear, coveralls, denim or jeans, jacket, pants, gloves, undergarments, socks, hats, skirts, aprons, head coverings, and T-shirts. A preferred garment or apparel is a denim or jeans.
[0043] The gradation of hues or fades is best illustrated with respect to FIG. 1 , where the dark blue denim fabric is dyed using the hypochlorite salt-containing composition of the present invention. The dark hue of the untreated fabric, generally indicated by the reference numeral 10 , is the untreated state of the color, which in this example is dark blue, as indicated in the color version of the Drawings submitted herewith. As noted above, treatment of the fabric with the hypochlorite salt-containing composition of the present invention at varying time intervals or treatment strengths results in patches of treated fabric of varying hues, such as also depicted in FIGS. 2-5 described hereinbelow.
[0044] As indicated in FIG. 1 , applying the composition to the fabric for a short period or at reduced concentration strength results in a patch having a lighter hue, generally indicated by the reference numeral 20 , which is a lighter shade of blue in this example. Further application of the composition, either for longer times, greater concentration strengths or both, results in additional patches of increasingly lighter hues, generally indicated by the reference numerals 30 , 40 , 50 , and 60 , respectively, until the color is substantially or entirely removed, as is designated by the reference numeral 70 .
[0045] With reference to FIGS. 2-5 , the varying application of the hypochlorite salt-containing composition of the present invention onto the untreated fabric results in a variety of patterns of varying hues. As indicated, the patterns can be enhanced by use of a template guide or applique to better control the treatment process and standardize the production process.
[0046] In one embodiment of the present invention, a consumer can purchase a kit containing the aforedescribed hypochlorite salt-containing composition along with instructions for use. Templates of patterns may also be purchased or constructed by the user. It should be understood that the user may employ the instant invention in a wide variety of artistic expression, creating patterns on fabrics of all types. As discussed, the principles of the present invention can be employed on apparel or any other fabric to create patterns, messages or other expression thereon. Designs can include purely ornamental works of expression as well as practical uses, e.g., camouflage or other functional usages. Indeed, the full measure of consumer use of the instant invention is subject only to the imagination of the user, and the instant invention provides the means for this new form of expression.
[0047] In another aspect of the present invention, the fabric or apparel items can be treated in a commercial fashion, such as on an assembly line or in an automated factory. Patterns can be coded into a program and the hypochlorite salt-containing composition can be directed on the subject fabric, e.g., sprayed or otherwise applied. As discussed, a uniform strength composition can be applied in a time-delayed fashion through multiple applications at staggered times, thereby obtaining varied hues, as noted above and as discussed in more detail hereinbelow. Another approach is a single application of the composition from multiple sources and in varying strengths to the entire fabric to achieve the desired pattern, and immerse the entire fabric at the end, thereby simplifying the process for throughput, as also discussed hereinbelow. It should be understood that various percentages of the composition can be formulated, each having a particular strength to fade the fabric over a common fixed time. Additionally, it should be understood that commercial manufacturing techniques could employ multiple treatments, differing compositional strengths and timed applications in a variety of ways to achieve a desired pattern, and deactivation can also be performed by a single or multiple partial or full immersions of the treated fabric.
[0048] For example, in FIG. 1 , as well as the remaining FIGURES, untreated fabric 10 can be passed through a device, as shown in FIG. 6A and generally designated by the reference number 600 , that dispenses a weak concentration of the hypochlorite salt-containing composition to slightly dye or bleach a portion, for example, patch 20 , and discrete increasing concentrations from respective dispensers to effectuate the remaining patches 30 , 40 , 50 , 60 , and the completely bleached patch 70 , which has the strongest concentration composition. Instead of multiple stagings and application over time, this one-step of substantially simultaneous dyeing of the fabric 10 handles the entire fabric once, i.e., in one pass of the apparatus.
[0049] With reference now to FIGS. 6A AND 6B , device 600 employs one or more dispensers 610 that dispense the aforementioned hypochlorite salt-containing composition of the present invention in either a uniform or varying concentrations. The dispensers 610 are disposed above a surface, designated by the reference numeral 620 in FIG. 6B , and a belt or other conveyor 630 , e.g., moving atop rollers 640 on surface 620 . A fabric for treatment, designated by the reference numeral 650 , e.g., a pair of pants as depicted in FIG. 6B , are placed atop conveyor 630 and transported adjacent the dispensers 610 , preferably vertically beneath them. It should be understood that the dispensers 610 can deliver the composition of the present invention in a variety of manners, e.g., simple dripping or spraying such as from jets, as discussed hereinabove. It should also be understood that the dispensers 610 preferably move relative to the fabric for treatment. For example, the dispensers 610 can move transversely and longitudinally with respect to the fabric to position the chemical treatment thereon. The dispensers 610 may also rotate about a position to direct the composition, for example, under pressure, to the fabric at an angle, thereby covering a radial area of the subject fabric for treatment. In this manner, transverse and longitudinal movement of the dispensers 610 can be minimized or eliminated. It should also be understood that the fabric 650 can be positioned under fixed dispensers 610 and moved relative thereto, transversely and/or longitudinally, to effectuate the same treatment.
[0050] Patterns can be created on the fabric being treated using a template, designated by the reference numeral 660 in FIG. 6B . Template 660 is disposed between dispensers 610 and the fabric for treatment 650 to control the application of the composition on the fabric, as discussed hereinabove. Thus, items placed on the belt or conveyor 630 move longitudinally under the dispensers 610 , which apply the composition, possibly through the template 660 to the fabric 650 . After this treatment, the conveyor 630 continues to transport the fabric 650 to an adjacent vat 670 . As illustrated in FIG. 6A , conveyor 630 immerses the treated fabric 650 , e.g., a rinse in cold water. The conveyor 630 then transports the dyed fabric 650 for pickup. It should, of course, be understood, however, that fabrics 650 can be passed through multiple devices 600 or reprocessed through the same device 600 to effectuate creation of a desired pattern.
[0051] As shown in FIG. 6A , the dispensers 610 can employ a number of discrete dispensers to deliver the composition of the present invention in a variety of ways. For example, by time offsetting a uniform concentration solution can be employed and a dispenser 610 A applies the composition to sections of the fabric 650 that are to be bleached-out or lightest. Subsequent dispensers 610 would apply the same uniform concentration composition to other sections at succeeding times, and a last dispenser 610 B would apply the composition to sections that would ultimately be slightly faded and have almost the original fabric color. In this fashion, the progression of the fabrics 650 for treatment can employ a plurality of templates 660 , each for directing a staged pattern portion until the last template completes the overall pattern.
[0052] It should also be understood that a plurality of fabrics 650 can be processed simultaneously, e.g., transversely in parallel across the conveyor 630 or having multiple longitudinal staging areas under the dispenser 610 , where multiple identical operations proceed simultaneously or substantially simultaneously, handling a batch of fabrics 650 at once.
[0053] With reference again to FIG. 6A , the dispensers 610 can employ varying concentrations of the composition of the present invention, e.g., dispenser 610 A has a full-strength concentration for application to sections of the pattern to be bleached-out or lightest. Subsequent nozzles or dispensers 610 apply weaker strength compositions to shade sections darker, i.e., less light, and the last dispenser 610 B would have the weakest strength composition. A variety of templates 660 could also be employed, as discussed hereinabove. It should be understood that ordering of the dispensers 610 in this scheme is not necessarily based upon composition concentration. In this fashion, there is no need for any time delay in application of the composition, as there is in the uniform composition embodiment, and the time for fabric 650 processing in the device 600 is minimized, speeding up processing. As with the previous embodiment, multiple fabrics 650 can be handled at once in parallel and through multiple staging areas.
[0054] It should, of course, be understood that a computer software program coded to implement the aforementioned applications can be operated by a controller computer that is coupled to the device 600 . The computer software program would allow the user to perform the aforementioned techniques and coordinate the various steps, e.g., setting the appropriate template 660 in place prior to application of the composition thereon, and then advancing the process accordingly. As discussed hereinabove, different design patterns to be applied to the fabric 650 , as illustrated in FIGS. 2-5 , can also be coded into the software program for the above-mentioned applications.
[0055] It should be understood that the above-described embodiments and the following examples are given by way of illustration, not limitation. Various changes and modifications within the scope of the present invention will become apparent to those skilled in the art from the present description.
EXAMPLES
Example 1
Creation of Jeans Fades Art to Denim Jeans Fabric
[0056] A flat dye brush (approximately 0.125×0.375×0.375 in) was used to apply the bleach in broad strokes and to make fine lines. The brush was dipped in a hypochlorite salt-containing composition, shaken to remove excess liquid and then applied to the fabric. Excessive liquid may diffuse into the adjoining areas of the pattern and may cause the loss of detail. On the other hand, insufficient liquid may require additional passes of the brush over the same area. Applications to a test fabric can be tried first to develop speed and skill. A template may be used as a guide for the application. After each section of artwork is completed, the template may be removed temporarily, if desired, to observe how the art is developing—being careful, of course, to replace the pattern exactly in the original location before continuing and be mindful of the treatment time.
[0057] Examples of the representative artwork are shown in FIGS. 2-5 . Each of the artistic patterns is transferred to the fabric in any manner of orientation or depiction. With care, the delicate renderings set forth in FIGS. 2-5 can be duplicated, improved upon or otherwise altered. Representative steps to achieve the patterns of FIGS. 2-5 or any other pattern are set forth below.
T = 0 min Apply the hypochlorite salt-containing composition to sections of the pattern that are to be bleached-out, i.e., to the base color of the fabric (usually white). These sections will be allowed to bleach for 30 minutes. T = 15 min Bleach sections that are to be light but not white, if any. T = 20 min Bleach sections that are to be a shade darker, if any. T = 25 min Bleach sections that are to be a next darker shade, if any. T = 27 min Bleach sections that are to be relatively darker, if any. T = 28½ min Bleach sections that are almost the original jeans color, if any. T = 30 min Immerse treated area of jeans or entire jeans in cold water, thoroughly rinsing out the bleach. This stops the bleach action and fixes the artwork.
[0058] It should be understood that the above steps for forming the fade artwork or other fade pattern employ a uniform concentration of the hypochlorite salt containing composition that is applied at offset time intervals and inactivated by water immersion. Steps for forming the same fade artwork shown in FIGS. 2-5 employing multiple dispensers of varying strength concentrations of the composition are set forth below.
T = 0 min Apply the hypochlorite salt-containing composition to sections of the pattern to be treated. A first nozzle applies a full-strength composition to those sections of the pattern to be bleached out, i.e., to the base color of the fabric (usually white). A second nozzle applies a weaker strength composition, e.g., half strength, to those sections that are to be light but not white, if any. A third nozzle applies a still weaker strength composition, e.g., one third, to form a shade darker area, if any. A fourth nozzle applies a still weaker strength composition, e.g., one sixth, to form a next darker shade, if any. A fifth nozzle applies a still weaker strength composition, e.g., a tenth. Finally, a sixth nozzle applies the weakest strength composition, e.g., one twentieth. T = 30 min Immerse treated area of jeans or entire jeans in cold water, thoroughly rinsing out the bleach. This stops the bleach action and fixes the artwork.
[0059] It should be understood that the number of discrete nozzles and the percentage strength compositions are variable and dependent upon the fade effect desired. For example, to minimize the entire processing time of a particular fabric, more powerful strength compositions may be employed to shorten the treatment time. Conversely, finer fade artwork or fade effects may be obtained using weaker concentrations, which would be useful on delicate fabrics. The techniques of the present invention may be employed in a variety of ways to achieve the creative results envisioned by the artists.
[0060] If desired, the artist can apply another color dye of choice to bleached-out or other sections of the artwork, such as a flower blossom. For example, in FIG. 5 , a red flower blossom is applied to a flower-shaped, bleached-out portion of the artwork, designated by the reference numeral 80 . After completing the application, the jeans can be handled in a customary manner, e.g., washed, dried or ironed. The artwork becomes part of the jeans color. With reference again to FIGS. 6A and 6B , it should be understood that the application of a different color can be accomplished by running the treated fabric 650 through the device 600 . The different color, e.g., red, can be applied to a section, e.g., a bleached-out portion, of the fabric 650 through an appropriately configured template 660 .
[0061] It should be understood that many modifications and variations of the present inventions are possible in light of the above teachings. While the invention has been described in its preferred embodiments, it is understood that the invention shall not be limited by thus description alone but in combination with the appended claims.
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This invention relates to a fabric having a pattern of fades and a methodology for their creation, both industrial and artistic. The fades are created by contacting at least one portion of the fabric with a hypochlorite salt-containing composition. The resulting fabric has a faded appearance either uniformly or non-uniformly. Methods, kits and a device for making a fabric having a pattern of fades are also disclosed.
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TECHNICAL FIELD
This disclosure relates generally to engine systems and, more particularly, to exhaust after-treatment systems and methods.
BACKGROUND
One known method for abating certain diesel engine exhaust constituents is by use of an exhaust after-treatment system that utilizes Selective Catalytic Reduction (SCR) of nitrogen oxides. In a typical SCR system, urea or a urea-based water solution is mixed with exhaust gas. In some applications, a urea solution is injected directly into an exhaust passage through a specialized injector device. The injected urea solution, which is sometimes referred to as diesel exhaust fluid (DEF), mixes with exhaust gas and breaks down to provide ammonia (NH 3 ) in the exhaust stream. The ammonia then reacts with nitrogen oxides (NO x ) in the exhaust at a catalyst to provide nitrogen gas (N 2 ) and water (H 2 O).
In typical applications, especially for large engines, high efficiency diesel particulate filters (DPF) are used in conjunction with NOx reduction systems such as systems using SCR. Such systems are generally quite effective in filtering soot while also converting NOx emissions from diesel exhaust, but such systems are also relatively large in volume. For example, a typical combined DPF/SCR after-treatment system, which may also include AMOX and DOC catalysts, can be approximately 3-6 times engine displacement in volume, which makes it challenging to design and integrate into a vehicle or engine system and also increases overall machine weight and cost.
It has been proposed in the past to coat the SCR catalyst onto the DPF filter substrate to eliminate a separate substrate for the SCR catalyst and allow DEF injection upstream of the DPF, but the low temperature soot oxidation reaction and fast SCR reaction will compete for NO 2 during engine operation, which will generally result in high DPF balance points, i.e., a system balance at high soot loadings on the DPF, which is known to make the DPF prone to cracking or catastrophic failure, and requires DPF regeneration at a high temperature. High temperature regeneration often requires so-called active regeneration, which entails conducting the regeneration using a heat source or a high fuel concentration, both of which reduce fuel economy for the machine.
One example of a previously proposed after-treatment system can be seen in U.S. Pat. No. 8,413,432 to Mullins et al. (“Mullins”). Mullins describes a regeneration control system for a vehicle that includes a regeneration control module and a regeneration interrupt module. The regeneration control module selectively provides fuel to an oxidation catalyst for a regeneration event of a particulate filter that occurs during a predetermined melting period for frozen dosing agent. The regeneration interrupt module selectively interrupts the regeneration event and disables the provision of fuel to the oxidation catalyst before the regeneration event is complete when a temperature of a dosing agent injector that is located between the oxidation catalyst and the particulate filter is greater than a predetermined temperature. As can be appreciated, therefore, the system of Mullins requires active regeneration.
SUMMARY
The disclosure describes, in one aspect, an after-treatment system. The after-treatment system is suitable for use, for example, with a machine that includes an engine having an exhaust conduit, which is adapted to route a flow of exhaust gas from the engine during operation. The after-treatment system may be connected to the exhaust conduit and disposed to receive and treat the flow of exhaust gas from the engine. The after-treatment system includes a diesel oxidation catalyst (DOC) connected to the exhaust conduit and arranged to receive the flow of exhaust gas from the engine, a transfer conduit connected in a downstream end of the DOC, a diesel exhaust fluid (DEF) delivery device associated with the transfer conduit and adapted to selectively inject DEF into the transfer conduit to be carried in a downstream direction by gas passing through the transfer conduit during operation, a soot-reducing device connected to a downstream end of the transfer conduit, the soot-reducing device arranged to receive the gas passing through the transfer conduit during operation, and a selective catalytic reduction (SCR) catalyst connected to a downstream end of the DPF opposite the transfer conduit, the SCR catalyst arranged to receive the gas passing through the soot-reducing device during operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an engine having a known SCR system, and FIG. 2 is a partially sectioned outline view of a known exhaust treatment module.
FIG. 3 is a block diagram of an after-treatment system in accordance with the disclosure.
FIGS. 4A and 4B are schematic configurations of a known system packaging envelope,
FIGS. 5A and 5B are schematic configurations of a first embodiment of an after-treatment system in accordance with the disclosure and relative to the known packaging envelope, and
FIGS. 6A and 6B are schematic configurations of a second embodiment of an after-treatment system in accordance with the disclosure and relative to the known packaging envelope.
FIG. 7 is a graph showing operation of an after-treatment system over time in accordance with the disclosure.
DETAILED DESCRIPTION
FIGS. 1 and 2 are representations of an exhaust after-treatment system 100 , which is known in the art. In the illustrated embodiment, the system 100 includes a first module 104 that is fluidly connected to an exhaust conduit 106 of the engine 102 . During engine operation, the first module 104 is arranged to internally receive engine exhaust gas from the conduit 106 . The first module 104 contains a diesel oxidation catalyst (DOC) 108 arranged in series, upstream from a diesel particulate filter (DPF) 110 , each of which has a relatively large frame. It is noted that the CDPF 110 is a coated DPF (CDPF). Exhaust gas provided to the first module 104 by the engine 102 first passes through the DOC 108 and then through the CDPF 110 before entering a transfer conduit 112 .
The transfer conduit 112 fluidly interconnects the first module 104 with a second module 114 such that exhaust gas from the engine 102 may pass through the first and second modules 104 and 114 in series before being released at a stack 120 that is connected to the second module. In the illustrated embodiment, the second module 114 encloses a SCR catalyst 116 and an Ammonia Oxidation Catalyst (AMOX) 118 , each formed on its own respective substrate. The SCR catalyst 116 and AMOX 118 operate to treat exhaust gas from the engine 102 in the presence of ammonia, which is provided after degradation of DEF injected into the exhaust gas in the transfer conduit 112 . A regeneration device 130 is disposed upstream of the first module 104 along the conduit 106 . The regeneration device 130 , which can be implemented as a fuel-fired heater, increases exhaust gas temperature for an active regeneration of the CDPF 110 , selectively during operation as is known.
The DEF 121 is injected into the transfer conduit 112 by a DEF injector 122 . The DEF 121 is contained within a reservoir 128 and is provided to the DEF injector 122 by a pump 126 . As the DEF 121 is injected into the transfer conduit 112 , it mixes with exhaust gas passing therethrough and is thus carried to the second module 114 . To promote mixing of DEF with exhaust, a mixer 124 may be disposed along the transfer conduit 112 . FIG. 2 is a partially sectioned outline view of the system 100 , where same or similar structures as corresponding structures previously described are denoted by the same reference numerals previously used for simplicity. As shown in FIG. 2 , the first and second modules 104 and 114 are disposed next to one another, with the transfer conduit 112 disposed between them. The DEF injector 122 is disposed on an upstream end of the transfer conduit 112 relative to a direction of exhaust gas flow, F.
FIG. 3 is a block diagram of an after-treatment system 200 in accordance with the disclosure. The system 200 is configured to replace the system 100 for the engine 102 ( FIG. 1 ) but without necessarily use of the regeneration device 130 and with a smaller package size, as will be described hereinafter. The system 200 includes a DOC 202 , which in this embodiment has a smaller diameter and an overall smaller volume than the DOC 108 ( FIG. 1 ). The DOC 202 may optionally further include a relatively small NOx absorber to improve flow temperature of exhaust gas temperature flowing there through. The system 200 is arranged such that the exhaust conduit 106 from the engine 102 ( FIG. 1 ) provides exhaust gas from the engine 102 to the DOC 202 , which operates in the known fashion. A transfer conduit 204 fluidly interconnects the DOC 202 to a treatment module 206 , which is connected to the stack 120 (also see FIG. 1 ) either directly or through a muffler (not shown). The treatment module 206 includes a series-compact device 208 , which in the illustrated embodiment includes a DPF 210 , and a combined SCR plus AMOx (SCR/AMOx) 212 . A DEF injector 214 is disposed along the transfer conduit 204 and arranged to inject DEF therein between the DOC 202 and the series-compact device 208 during operation such that injection of DEF occurs downstream of the DOC 202 and upstream of the series-compact device 208 .
For achieving desired emissions, the DPF 210 in the illustrated embodiment is a monolithic, wall-flow type substrate that can be made from advanced cordierite (AC) or aluminum titanate (AT) having an asymmetric channel (ACT) construction with larger inlet and smaller outlet channels. The DPF 210 shown has about 300 channels per square inch (cpsi) and is uncoated, uncatalyzed or includes a hydrolysis coating. During operation, the DOC 202 creates NO 2 from NO and O 2 present in the exhaust stream. The NO 2 created by the DOC 202 is carried to the DPF 210 to support a passive regeneration of the DPF 210 at a relatively low temperature of about 200 def. C.
The SCR/AMOx 212 of the system 200 in the illustrated embodiment is built on a substrate having about 600 cpsi that is physically connected to the substrate of the DPF 210 or is otherwise in close proximity thereto within the treatment module 206 to act as a single substrate. In the illustrated embodiment, the system 200 operates to remove more than 98% of engine soot on a mass or particulate count basis, and reduces NOx by more than 96% on a mass basis.
In general, the after-treatment system 200 may include additional or alternative structures for treating the exhaust gas stream provided from the engine 102 . For example, in an alternative embodiment, a soot-reducing, soot-filtering or soot-removing device such as an electrostatic precipitator, a plasma burner or any other known soot-removing device may be used instead of, or in addition to, the DPF 210 in the after-treatment system 200 . The term soot-reducing device, as used herein, is contemplated to include any structure that operates to at least partially remove soot and/or other particulates from an exhaust stream of an engine as the exhaust stream passes through, over or around the soot-reducing device. Moreover, in an alternative embodiment, the after-treatment system 200 may be configured and/or sized to remove an optimized fraction of soot, for example, between 10% and 90% on a mass or particulate count basis, and to reduce NOx by an optimized fraction, for example, more than 70% on a mass basis, from the flow of exhaust from the engine.
INDUSTRIAL APPLICABILITY
This disclosure relates to after-treatment systems for diesel engines used alone or in conjunction with other power sources and types in a machine. More particularly, the disclosure describes use of an uncatalyzed or hydrolysis coated low backpressure DPF, which allows DEF dosing upstream of a single can with a series DPF and SCR catalyst. One challenge in designing and integrating a combined DPF/SCR system for an engine in a machine is the requirement for DEF injection to be downstream of the DOC or a catalyzed DPF to avoid ammonia oxidation to NOx. The described embodiments advantageously reduce package size and weight for the after-treatment devices as compared with known systems while maintaining passive soot oxidation capability, i.e., the ability to avoid using active DPF regeneration, which avoid the cost, complexity and fuel consumption increase associated with active regeneration. The described systems and methods, therefore, provide greater flexibility than known systems have to integrate low or high temperature thermal management. Additionally, the systems in accordance with the disclosure provide the capability of moving or relocating the DPF from in-series with the DOC, as is the case in known systems, to a remote location, for example, on the engine. This flexibility also allows the DOC aspect ratio to be optimized for packaging resulting in considerable height and width reductions of 15% or more as compared to previously known systems. Overall, the disclosed systems and methods provide a compact, high efficiency package that works with low or high temperature DPF regeneration.
The present disclosure is applicable to internal combustion engines operating in mobile or stationary applications. The disclosed systems are advantageously more compact the systems having comparable emission constituent abatement performance. The systems in accordance with the present disclosure are simpler and more cost effective to operate in that the DPF used is suitable for both passive and active regeneration, which makes use of an active regeneration device optional.
To illustrate the package size benefit of the system in accordance with the present disclosure, various qualitative representations are compared. In general, while the DPF 210 and SCR/AMOx 212 may have a diameter that is comparable to the SCR catalyst 116 and AMOX 118 ( FIG. 1 ), the combined series-compact device 208 has an overall length that is quite shorter than the overall combined substrate length of all devices used in the system 100 ( FIG. 1 ), which greatly reduces the overall package size of the various systems. This is discussed below relative to FIGS. 4A and 4B as compared to FIGS. 5A, 5B, 6A and 6B .
More specifically, FIG. 4A qualitatively shows a packaging envelope 302 for the components of the system 100 ( FIG. 1 ), in block form, from a top perspective, and FIG. 4B shows the packaging envelope 302 from a front perspective. As can be seen from these figures, where arrows “F” denote the flow of exhaust gas through each system, a footprint of the packaging envelope 302 is defined by the space that is required to accommodate arrangement of the DOC 108 and CDPF 110 on the right side, and the SCR catalyst 116 and AMOx 118 on the left side of FIG. 4A in the orientation shown. A cross sectional area of the packaging envelope 302 is similarly defined by the diameters of the various substrates mentioned above, as well as by the diameter of the transfer conduit 112 , as shown in FIG. 4B .
FIGS. 5A and 5B show the components of the system 200 in accordance with the disclosure arranged within the packaging envelope 302 of the system 100 for comparison and to illustrate the space-saving nature of the system 200 over the system 100 . As shown, the arrangement of the smaller-diameter DOC 202 allows the centerline of the series-combined substrates for the DPF 210 and the SCR/AMOx 212 to move closer to a centerline of the DOC 202 , which results in an overall narrower combined width for these components and more space being available to route the transfer conduit 112 . Therefore, and as can be seen from FIGS. 5A and 5B , the volume 304 required to contain or package the system 200 is about 15% less than the volume occupied by the packaging envelope 302 , with additional space being available around the components to route other machine components, add shielding, and the like.
FIGS. 6A and 6B show the components of the system in accordance with an alternative embodiment of the disclosure, in which the DOC 202 is mounted remotely from the remaining components of the system 200 , for example, on the engine or anywhere along the exhaust conduit supplying exhaust gas from the engine to the system 200 . In this embodiment, the DOC 202 is placed outside from the packaging envelope 302 due to its remote mounting. The series-combined substrates for the DPF 210 and the SCR/AMOx 212 are moved to one side of the envelope thus reducing the volume 306 required to contain or package the system 200 by about 50% or more relative to the volume occupied by the packaging envelope 302 .
A qualitative graph showing the soot loading in the DPF of the system 200 as compared to the system 100 over time is shown in FIG. 7 . In the graph, the horizontal axis 308 represents time, for example, in hours, and the vertical axis 310 represents soot loading, for example, as a percentage of a critical soot loading 312 at which the DPF plugging with soot particles is beyond a desired extent and may render the DPF essentially plugged. The graph shows two curves, a first curve 314 and a second curve 316 . The first curve 314 represents a soot loading over time of the CDPF 110 ( FIG. 1 ) of the system 100 , which is considered as the baseline system. The second curve 316 represents a soot loading over time of the DPF 210 of the system 200 ( FIG. 3 ) of the system 200 in accordance with the disclosure.
As can be seen from the graph, the soot loading in both DPFs increases initially before stabilizing and reaching a balance point over time because in both systems 100 , 200 the DPF continuously regenerates during operation and reaches a steady-state soot loading. When comparing the curves 314 and 316 , it can be seen that the loading in the DPF 210 in the system 200 settles at a soot loading that is higher than the corresponding soot loading in the CDPF 110 in the system 100 . However, although the soot loading in the DPF 210 is higher than the loading in the CDPF 110 , both are still below the critical soot loading 312 . As a practical matter, the higher soot loading in the DPF 210 , which may increase the pressure drop across the DPF, will not appreciably affect engine operation given the relatively higher cell density of the SCR/AMOx 212 used in the system 200 as compared to the system 100 .
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
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An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst.
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RELATED APPLICATIONS
[0001] This patent application is a divisional of U.S. patent application Ser. No. 12/911,613 entitled “Light-Based Method for the Endovascular Treatment of Pathologically Altered Blood Vessels” filed on Oct. 25, 2010, and claims priority to PCT Patent Application No. PCT/EP2009/003027, entitled “Light-Based Method for the Endovascular Treatment of Pathologically Altered Blood Vessels,” filed Apr. 24, 2009, which claims priority to U.S. Provisional Patent Application No. 61/047,779 filed Apr. 25, 2008. The complete disclosure of each of the above-identified priority applications is hereby fully incorporated herein by reference.
[0002] The following presents a new, light-based method of endovascular treatment, in particular of pathologically altered blood vessels. Provided are a Method of Endovascular Light Treatment and a corresponding Endovascular Light Application Device.
INTRODUCTION
[0003] All sorts of different therapy options are available to the therapist for the treatment of pathologically altered blood vessels. In addition to the classic surgical methods, endovascular therapies have become increasingly important in recent times. In particular, light-based endovascular thermal methods for the obliteration of, for example, insufficient truncal veins have been integrated into the broad spectrum of therapy options for a few years. One of these light-based thermal therapies is Endovascular Laser Therapy (EL T). In this, certain light application systems are placed in the blood vessel which emit therapy light onto the wall of the blood vessel. The therapy light is absorbed by the tissue and/or blood, which causes the vein wall to heat up, leading in turn initially to a thermal necrosis of the cells in the blood vessel wall with a collagen contraction and wall thickening, usually followed by a thrombotic closure of the treated vein. The subsequent inflammatory reaction and repair processes lead, sometimes not before after a number of weeks, to the obliteration of the truncal vein that has been treated and thus to the hemodynamic disconnection of the treated vein segment and branch varicose veins that were supplied by this.
STATE OF THE ART
[0004] The aim of endovascular therapy is inter alia to close pathologically altered blood vessels using a minimally invasive method. A procedure currently known and practiced to achieve this therapeutic aim is as follows: After puncturing the vessel to be treated, a simple fiberglass or complex-structure energy applicator or light applicator is positioned intravenously usually via a type of catheter system using a sort of Seldinger technique and therapeutic light is applied in this way. Before or during the treatment, however, the catheter system, which is only used for positioning, is generally pulled out of the vessel along with the light applicator, whilst emitting the laser light. It is assumed that the blood vessel closes immediately with this treatment method, especially because of the instant contraction and/or the formation of a thrombus. With this method, the light is usually applied to a limited area of the vessel during a short period of time.
[0005] These systems of the prior art, especially within ELT, often suffer from high local temperatures of several 100° C. up to more than 1000° C. This leds to a variety of problems, including protein agglomeration or aggregation, carbonizing of organic material or unwanted destruction or perforation of healthy structures or ingredients of body fluid or even of the applicator. This may lead to clinical complications such as hematomas, phlebitis, erythema, ecchymosis and other lesions of tissues, e.g. also at nerves, or even unspecific pain.
[0006] When applying the Seldinger Technique, the desired vessel or cavity is punctured with a sharp hollow needle, also called access needle or trocar, optionally with ultrasound guidance if necessary. Commonly a round-tipped guidewire is then advanced through the lumen of the access needle, and the access needle is withdrawn. The catheter or “catheter sheath” is inserted along the guidewire into the cavity or vessel, optionally after enlarging the puncture channel employing a dilator. After final introduction of the catheter sheath, the guidewire is withdrawn.
[0007] Ultrasound guidance or fluoroscopy may be used to confirm the position of the catheter and to manoeuvre it to the desired location. Injection of radiocontrast may be used to visualise organs. Interventional procedures, such as thermoablation, angioplasty, embolisation or biopsy, may be performed.
[0008] Upon completion of the desired procedure, the sheath is withdrawn. In certain settings, a sealing device may be used to close the hole made by the procedure.
[0009] In the prior art the light emitting part of the light applicator, usually a special fibre tip or especially a bare fibre tip, is always shifted through the open distal end of the catheter (catheter sheath) and is used in contact with the vessel and/or fluid within the vessel withdrawing applicator and catheter (catheter sheath) together while applying light.
[0010] Other approaches of the prior art directly introduce the light applicator only into the vessel. This is an one step technique. Upon percutaneous puncture of the vessel, the light applicator is introduced into the vessel and moved to the location of interest within the vessel, often with ultrasound guidance and while the light applicator is moved back (in direct contact with the vessel or fluid within the vessel) light energy is applied to the length of the vessel that shall be treated. A repeated moving of the light applicator to the same position is impossible. A punctual adhesion of tissue or blood on the surface of the applicator may even lead to a local overheating of the vessel or the applicator.
[0011] WO99/12489, U.S. Pat. Nos. 7,396,355, 6,752,803 and 6,258,084 disclose an electrocatheter suitable for shrinking blood vessels upon applying energy. The catheter comprises working electrodes, which are—when used—expanded from the catheter and are in direct contact with the blood vessel to be treated. In use, a tumescent fluid is injected into the tissue surrounding the treatment site. A further development of this electrocatheter is disclosed in WO 00/10475, U.S. Pat. Nos. 6,769,433 and 7,406,970. The electrode is put in apposition with the vessel wall and the wall is pre-shaped before applying energy to the electrodes.
[0012] WO 2007/014063 discloses a catheter including a therapeutic element, such as a resistive heating element usable to deliver energy for ligating, or reducing the diameter of a vessel.
[0013] US20060069417 discloses a catheter, which introduces electrodes in a vein for a minimally invasive treatment of venous insufficiency by the application of energy to cause selective heating of the vein. The catheter is positioned within the vein to be treated, and the electrodes on the catheter are moved toward one side of the vein. RF energy is applied in a directional manner from the electrodes at the working end of the catheter to cause localized heating and corresponding shrinkage of the adjacent venous tissue.
[0014] WO00/44296 and EP 1156751 81 disclose an endovascular laser device for treating varicose veins. The device of EP 1156751 81 comprises a
a) laser of a wavelength in the range 500-1100 nm, which delivers laser energy in bursts and is arranged to emit laser energy to cause thermal damage to a vein wall so as to result in a subsequent decrease in the diameter of said vein; b) a fibre optic line; and c) an angiocatheter for insertion into a blood vessel, wherein said angiocatheter and said fibre optic line are arranged and adapted such that in use said fibre optic line makes intraluminal contact with a vein wall and said fibre opticline ends in a bare tip and the tip of said fibre optic line is arranged and adapted to be in direct contact with said vein wall during treatment of said vein.
[0018] However, similar to the other catheters of the prior art, in which energy is applied upon contacting an energy or light applicator to the interior wall of the vessel, this device of EP 1156751 81 may cause unwanted damage to the interior wall of the vessel to be treated due to the exposure of the fibre optic line to the vessel wall. In addition, when in use the free fibre optic line of EP 1156751 81 may cause pain and small injuries such as perforations and hematomas. Moreover, there is a risk that the fibre optic line breaks during treatment and may be lost, at least partially, in the vessel.
[0019] Thus, there is a need in the art to provide an improved device for intraluminal treatment of blood vessels, which allows a safer treatment of patients, reduces risks and pain and preferably allows a better controlled application of light energy to the blood vessels.
SUMMARY OF THE INVENTION
[0020] To fulfill this need, the present invention provides a blood vessel treatment device comprising: a light applicator connected to the light emitting unit, and a catheter/applicator tube for inserting the light applicator into and for guiding the light applicator within a vessel, wherein said catheter and said light applicator are arranged and adapted such that in use at any time said light applicator does not make intraluminal contact with any vessel wall and the light applicator is capable of delivering light energy through the sheath of the catheter so as to emit light energy to cause damage to a vessel wall, preferably so as to result in a subsequent decrease in the diameter of said vessel.
[0021] This device surprisingly overcomes the problems in the art arising from applying high energy densities while contacting the light applicator directly to the vessel, such as high local temperatures, protein agglomeration or aggregation, carbonizing of organic material or unwanted destruction of healthy structures or ingredients of body fluid or the applicator itself.
[0022] Surprisingly, although the catheter is not removed until the application of energy to the vessel has been completed (i.e. the catheter is still in place while the applicator has already been removed), the vessel—upon removal of the catheter—shrinks or collapses as intended.
[0023] With this surprising solution, also vessels may be treated safely, which encompass many bendings or vessels at bends or at constrictions may be treated, since the catheter protects the vessel from the risk of local damage arising from contact with the light applicator. Also a punctual adhesion of tissue or blood on the surface of the applicator is methodically and technically excluded, inhibiting local overheating of the vessel or the applicator.
[0024] Even if the light applicator should be damaged, the catheter protects the vessel from damage. In case of break-down, the fragments of the light applicator can be easily withdrawn from the vessel, since they remain inside the catheter.
[0025] The skilled person may easily control and! or optimize the result of the treatment. In a preferred embodiment, thus, an ultrasound or radioactive imaging unit for imaging the treated vessel and! or a temperature or coagulation detecting unit are placed within the catheter.
[0026] The device is preferably a sterile device. Sterilization and reuse of the applicator is comparatively easy, since the light applicator is not in contact with body fluids, tissue or the vessel to be treated.
[0027] Two embodiments of the device are particularly preferred. In the first embodiment, the device is open at the distal end and the catheter may be introduced into the vessel employing the Seldinger Technique. In the second embodiment, the device is closed at the distal end and the catheter may be introduced into the vessel in a one-step-process, without the need of using a wire guide. Both embodiments are described in detail below and are exemplarily shown in FIG. 2 .
[0028] The devices of these two embodiments may even be compatible with each other, i.e. the device of the present invention may such that it can be inserted employing both techniques. Accordingly, in a third embodiment—for the first time to our knowledge with the same device—a change between these two techniques even during the therapeutic intervention is possible; just the catheter has to be changed or only to be modified, e.g. cut, at the tip.
[0029] In addition, a kit is provided comprising one or more light applicators, e.g. for different purposes or different laser units; a catheter for inserting the light applicator into and for guiding the light applicator within a vessel; a guide wire; and an access needle, wherein said catheter and said light applicator are arranged and adapted such that in use at any time said light applicator does not make intraluminal contact with any vessel wall and the light applicator is capable of delivering light energy through the sheath of the catheter so as to emit light energy to cause damage to a vessel wall, preferably so as to result in a subsequent decrease in the diameter of said vessel.
[0030] Also provided is a method of applying light energy from a light emitting unit to a blood vessel, from within the vessel, the method comprising the steps of: introducing into the vessel the device as described above; and applying energy to the vessel until the vessel is damaged, preferably until the damage results in a decrease in the diameter of said vessel; further provided is a method of damaging a vessel using light energy from a light emitting unit, the method comprising the steps of: introducing into the vessel the device as described above; and applying energy to the vessel until the vessel is damaged, preferably until the damage results in a decrease in the diameter of said vessel.
[0031] In analogy to the embodiments of the device of the present invention, also the method of the present invention is represented by two preferred embodiments. In the first embodiment, the device is open at the distal end and is introduced into the vessel employing the Seldinger Technique or kind of Seldinger Technique. In the second embodiment, the device is closed at the distal end and the catheter may be introduced into the vessel in a one-step-process, without the need of a wire guide.
[0032] All these methods allow for cosmetic treatment of varicose veins or alternatively the treatment of pathologically altered blood vessels for medical purposes.
[0033] However, with this new method, the light applicator is guided in the catheter system for the duration of the therapy (e.g. with a speed of approx. 1-5 mm/s) and the catheter itself is only pulled out of the vessel after completion of the light treatment, preferably until after the damaging of the vessel wall treated by (laser) light is achieved. Because the light applicator is guided in the catheter system, there is no direct contact between the light applicator and the blood vessel wall (see illustration in FIG. 1 ). In addition, with this measure, the vessel or vein to be closed is prevented, during the entire laser application by a sort of catheter system, from shrinking immediately or completely closing. This catheter system is therefore also a central component of a suitable blood vessel treatment device or light application system and light is passed through it during the continuous or a section-wise treatment. The catheter itself may also redefine or further optimize the desired light emission properties of the light applicator. The blood vessel is largely kept open for the duration of the therapy, and the immediate closure of the vessel is prevented. The treated blood vessel may only be obliterated after treatment when the catheter system is removed.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In one aspect, the present invention provides a vessel treatment device comprising: a light applicator connected to the light emitting unit; and a catheter for inserting the light applicator into and for guiding the light applicator within a vessel, wherein said catheter and said light applicator are arranged and adapted such that in use at any time said light applicator does not make intraluminal contact with any vessel wall and the light applicator is capable of delivering light energy through the sheath of the catheter so as to emit light energy to cause damage to a vessel wall, preferably so as to result in a subsequent decrease in the diameter of said vessel.
[0035] The device is suitable to treat any hollow vessel in a mammal, preferably in a human. The “vessel” may be any hollow anatomical structure. In a preferred embodiment, the vessel is a blood vessel, most preferably a vein.
[0036] Conditions of said vessel to be treated in line with the present invention encompass the treatment of varicose veins for cosmetic and/or therapeutic purposes and, optionally, in connection with a tumescence local anesthesia. Also in line with the present invention is a single or multiple treatment of a vessel by photodynamic therapy.
[0037] Preferably, the vessel treatment device further comprises a light emitting unit, said light emitting unit being connected to the light applicator. The light may be laser light. The light emitting unit may be a laser, e.g. a pulsed laser or CW laser, or another means for inducing a thermal effect and/or a photodynamic effect. Any conventional or commercially available laser may be employed.
[0038] In many embodiments of the present invention, the wavelength of the laser light or emitted by the laser is in the range of about 500-2000 nm referring to the optical properties of tissue, preferably in the range of 700-1500 nm.
[0039] The Power of the light emitting unit, e.g. of the laser, may be in the range of 1 to 150 W, preferably in the range of 10 to 50 W, more preferably 15 to 40 W.
[0040] The Energy and the power density applied per cm 2 at the emitting surface or emitting area of the light applicator is much lower (at least 1 to 3 magnitudes lower) than in conventional applicators, since the energy emitting part (“emitting surface” or “emitting area”) of the applicator is much larger than in the prior art, where only a bare fiber or other locally very confined tip area emits light. According to the invention the length of emitting surface or emitting area is preferably in the range of 3 to 70 mm, more preferably in the range of 10 to 30 mm. In a preferred example the emitting part is about 25 mm long. The area of the emitting surface or emitting area of the light applicator is in the range of 0.1 cm2 to 10 cm2, preferably 0.5 cm 2 to 5 cm 2 , most preferably 1 cm 2 to 3 cm 2 . The power density at the emitting surface or emitting area of the light applicator is in the range of 1 to 200 W/cm 2 , preferably 10 to 100 W/cm 2 , and most preferably 20 to 35 W/cm 2 .
[0041] Also the radiation profile and the easy movability of the light applicator may be adapted to allow to overcome the disadvantages of the point-shaped energy application of the prior art, e.g. protein carbonization. The overall energy needed can be better controlled employing the movable light applicator and/or the radiation profile of the present invention.
[0042] The light applicator is connectable to the light emitting unit. In one embodiment, the light applicator is a fibre optic line, preferably comprising a light applicator tip or a fibre optic tip, most preferably a cylindrical diffuser.
[0043] The light applicator may have a length of e.g. 10 to 500 cm, preferably 30-300 cm, more preferably, 200-300 cm. This applies in particular, if the light applicator is a fibre optic line.
[0044] The diameter of the light applicator may e.g. be between 0.1 and 2.5 mm, preferably in the range of 0.3 to 1.9 mm, more preferably in the range of 0.5 to 1.8 mm, even more preferably in the range of 0.7 to 1.7 mm, even more preferably in the range of 1.0-1.6, most preferably in the range of 1.1 to 1.2 mm. This applies in particular, if the light applicator is a fibre optic line. The diameter of the catheter is always a bit (approximately 0.1 to 2 mm) bigger than of the corresponding light applicator. A catheter, which is inserted using the Seldinger Technique, is normally of a larger diameter compared to a catheter inserted in a one step procedure.
[0045] In one embodiment, the diameter of the fibre optic tip is between 0.1 and 2.5 mm, preferably in the range of 0.6 to 2.4 mm, more preferably in the range of 1.0-2.3 mm; even more preferably in the range of 1.3 to 2.2 mm, even more preferably in the range of 1.4 to 2.1 mm; even most preferably in the range of 1.5-1.9 mm.
[0046] The light applicator may be of a uniform cylindrical shape. In one embodiment, the light applicator emits light in a cylindrical, ideally radial profile.
[0047] In one embodiment, the light applicator comprises light emitting areas, which are locally or systemically distributed in front of the fibre surface and are capable of emitting light more or less perpendicular to the fibre axis. Preferably, the light emitting areas are placed at the distal end of the light applicator and extend over 1 to 10 cm, preferably 2 to 5 cm. The light emitting areas may comprise scattering particles.
[0048] FIG. 3 shows a homogeneous and an inhomogeneous cylindrical radiation profile.
[0049] The homogeneous cylindrical radiation profile preferably has a length along the axis of 1 to 5 cm, more preferably 2 to 4 cm, most preferably 2 to 3 cm. This leads to a reduced light intensity, as compared to the prior art, which conventionally employs a non-areal, but point-shaped light emission by a optic fibre laser tip, thereby applying very high local intensities.
[0050] In particular embodiments, an inhomogeneous distribution may be reasonable to further reduce the total necessary light energy. At the proximal end of the emitting area more light is applied as at the distal end. This mode of emitting light, causing fast preheating of the tissue at the proximal end, saves energy since the total energy required is somewhat lower when compared to homogenous profile, as e.g. shown in FIG. 3 a . The exact shape of the preferred embodiment is a kind of exponential decay, as this can be easily realized by volume scattering. Also the inhomogeneous cylindrical radiation profile preferably has a length along the axis of 1 to 5 cm, more preferably 2 to 4 cm, most preferably 2 to 3 cm.
[0051] The catheter is for inserting the light applicator into the vessel and for guiding the light applicator within the vessel. In general, any conventional catheter may be employed, as long as this catheter is highly transparent for the therapeutic light and inter alia photochemically inert. In preferred embodiments, it is made of Teflon or PTFE. Wherever reference is made to a “catheter”, this is meant to encompass also any applicator tube in general.
[0052] Preferably, the catheter, in particular the sheath of the catheter, i.e. its tubular envelop, is partially, more preferably fully optically transmissible for light emitted from the light applicator. The surface of the catheter or the sheath of the catheter may have a coating, e.g. a hydrophilic coating. A hydrophilic coating allows for easier inset into and removing out of the blood vessel. Preferably, the distal end of the catheter is closed. More preferably, also the sheath of the catheter is cylindrical and fully optically transmissible for light emitted from the light applicator. The sheath of the catheter may even help, e.g. to homogenize, the radiation profile.
[0053] Catheter and light applicator are arranged and adapted such that in use at any time said light applicator does not make intraluminal contact with any vessel wall. Preferably the light applicator is placed within the sheath of the catheter, and may be flushed, preferably by a transparent physiological solution. Here, the catheter may be open to or
[0054] in open contact with the fluid within the vessel, although the light applicator does not protrude from the catheter or the catheter sheath and stays safely secured inside the catheter.
[0055] If the catheter is open, the device may be introduced employing the Seldinger Techniques, i.e. using a guide wire in analogy to classical insertion processes of the prior art as explained above. However, in this invention, the light applicator is not shifted through the open distal end of the catheter so that the light applicator does not make intraluminal contact with the vessel, i.e. the applicator does not make intraluminal contact with any vessel wall (see also FIG. 2 , “principle A”). The catheter in this embodiment is flushable and flushing fluid, preferably an aqueous solution, more preferably a physiological solution may be used to clean and/or cool the light applicator.
[0056] If the catheter is closed, the device may be introduced employing a one step technique, i.e. without using a guide wire. After puncture of the vessel, the catheter is inserted into the vessel (see also FIG. 2 , “principle B”). This is contrary to the prior art, wherein only the light applicator is introduced in such a one step technique, but not a catheter bearing the light applicator. The catheter mayor may not encompass the light applicator during the insertion step depending on the rigidity of the device encompassing catheter and light applicator needed. The catheter alone is more flexible, while catheter together with light applicator is a more rigid unit.
[0057] In preferred embodiments, the light applicator is intended not to be in contact with blood when in use. These embodiments minimize the risk to create carbonization effects in the vessel, since neither vessel, nor blood are in contact with the light applicator and there is no primary heat of the light applicator as energy is transferred by the emitted light. Also secondary heat within the applicator can be attenuated given by the spacing between light applicator inside the catheter and the (part of the) vessel to be treated.
[0058] The minimal distance from the light applicator tip to the distal end of the catheter is in the range of 1.0 to 30 mm, preferably in the range of 2.0 to 20 mm, more preferably in the range of 3.0 to 10 mm, most preferably in the range of 5.0 to 8.0 mm.
[0059] The light applicator is capable of delivering light energy through the sheath of the catheter and to cause damage to a vessel wall. This delivering of light energy preferably results in a subsequent decrease in the diameter of said vessel wall; most preferably until the shrinkage or collapse of vessel wall.
[0060] The light applicator during use may be placed repeatedly at the same position within the vessel with or without moving the catheter. Preferably, the light applicator is movable within the catheter; more preferably the light applicator is movable within the catheter when in use. Most preferably the light applicator is movable with constant velocity, e.g. with a velocity of 1 to 5 mm/s, preferably 1.0 to 4.0 mm/s, more preferably 2.0 to 3.0 mm/s; most preferably, the velocity is controlled by a velocity control unit.
[0061] It is also conceivable that the catheter and light applicator are moved towards each other at different speeds.
[0062] Visible pilot light, coupled into the applicator, could also be used, for example, to determine the position of the light applicator. Other types of labels may be used alternatively, e.g. fluorescent markers.
[0063] In a preferred embodiment, the blood vessel treatment device of the invention further comprises an ultrasound, magnetic resonance or radioactive imaging unit for imaging the vessel to be treated; and/or a velocity control unit for controlling the velocity with which the light applicator is moved within the catheter and/or a temperature or coagulation detecting unit inside the catheter for determining the temperature or tissue properties at the position, where the vessel is damaged and/or an imaging unit, connected to the one or more of the three units above for displaying the data measured by these one or more units. In addition a closed loop unit may be present based on the imaging unit, which closed loop unit provides a feedback controlling the parameters light intensity and/or velocity or segmentation of movement. “Segmentation of movement” means that the light applicator is moved stepwise, i.e. moved to one position in the catheter, keep for a short time interval and moved to a next position, and so on.
[0064] The temperature when using the device of the present invention is preferably kept in the range between 37° C. and 200° C., more preferably below 150° C., most preferably below 100° C. Each position is preferably “heated” by employing the light applicator for 1 to 25 s, more preferably 2 to 15 s, most preferably 5 to 10 s. This time range helps to allow a mild treatment, thereby avoiding high temperatures. If more energy needs to be applied to a particular position in order to deliberately damage or shrink the vessel, the light applicator can be moved and used several times to treat the same position.
[0065] In its second aspect, the present invention provides a kit comprising one or more light applicators; a catheter for inserting light applicator into and for guiding the light applicator within a vessel; a guide wire; and an access needle, wherein said catheter and said light applicator are arranged and adapted such that in use at any time said light applicator does not make intraluminal contact with any vessel wall and the light applicator is capable of delivering light energy through the sheath of the catheter so as to emit light energy to cause damage to a vessel wall, preferably so as to result in a subsequent decrease in the diameter of said vein wall. The kit may be used to prepare the device of the first aspect of the present invention and to insert said device employing the Seldinger Technique.
[0066] In its third aspect, the present invention provides a method of applying light energy from a light emitting unit to a vessel from within the vessel, the method comprising the steps of: introducing into the vessel the device of the first aspect of the invention and applying energy to the vessel until the vessel is damaged or collapses. While the light emitting unit may be introduced into the vessel, e.g. in a miniaturized version, it is preferred herein that “introducing into the vessel the device of the first aspect of the invention” means that only the catheter and the light applicator are introduced into the vessel and the light emitting unit, if part of the device, is connected thereto, but stays outside the vessel.
[0067] “Collapse” or “collapse of the vessel” in particular means that the structure of the vessel, in particular of the wall of the vessel is destroyed, preferably so as to close the vessel from any flood of fluid, preferably from flood of blood.
[0068] “Damage” or “damage of the vessel” preferably means that the structure of the vessel, in particular of the wall of the vessel is altered in its geometry and/or stability. Preferably, the diameter of the vessel decreases when damage of the vessel occurs. In one embodiment, the vessel decreases in its diameter to less than 90% of the original diameter, i.e. before start of applying energy, preferably, the vessel decreases in its diameter to less than 85%, to less than 80%, to less than 75%, to less than 70%, to less than 65%, to less than 60%, to less than 55%, to less than 50%, to less than 45%, to less than 40%, to less than 35%, to less than 30%, to less than 25%, to less than 20%, to less than 15%, to less than 10%, to less than 5%, to less than 4%, to less than 3%, to less than 2%, to less than 1% of the diameter before applying the light energy, most preferably it shrinks until the vessel is closed or until no fluid or blood can flow through at the damaged position (“obliteration”).
[0069] Optionally, perivenous tumescence may be used to support the treatment, preferably by administering local anesthesia and/or for reducing the risk of damaging of surrounding tissues, in particular nerve tissues.
[0070] Upon finalizing the vessel treatment, shrinkage or damaging, the catheter is withdrawn from the vessel. This may be guided with optical, radioactive or acoustic labels, preferably placed at the distal end of the catheter.
[0071] The method of this third aspect of the invention may also be used for damaging a vessel using light energy from a light emitting unit.
[0072] In one embodiment, the method of this third aspect of the invention, further comprises the step of placing the light applicator repeatedly, i.e. at least twice, at the same position in the catheter and therewith in the vessel while continuing to apply energy to the vessel. This may allow for a safer and more regular treatment of the vessel. Preferably, the method comprises the step of moving the light applicator in the catheter and therewith in the vessel while continuing to apply energy to the vessel.
[0073] In many embodiments, the method of this third aspect of the invention comprises imaging the vessel to be treated, controlling the velocity with which the light applicator is moved within the catheter, or determining the temperature or tissue properties at the position, where the vessel is damaged.
Applications of the Present Invention
[0074] In particular, the device and method of the present invention can be used in the treatment of varicose veins and, in particular, in connection with a tumescence local anesthesia.
[0075] In the treatment of varicose veins, the shrinking and/or closure of the vein is brought about by a combination of spontaneous contraction, thrombotic closure (on a comparatively small scale) and later fibrotic transformation of the blood vessel and support by secondary effects (such as wound healing). These biological effects are primarily induced through the effect of heat. The absorption of light which causes warming occurs here both in the blood and on the vein wall itself.
[0076] The embodiments of the present invention as set forth above, offer the advantages over other techniques in the art in clinical use as follows:
The application system can be introduced into the blood vessel using the Seldinger technique or a modification of the Seldinger technique or directly by using a closed catheter. During the introduction of the system by Seldinger technique and application of light, the application system can be rinsed via the catheter, e.g. to allow cooling. During the treatment, the blood vessel wall can be irradiated in several sections, i.e.
[0080] after a section has been irradiated, the; application system is steadily moved forward by roughly the length of this section. It is also conceivable that the outer catheter and inner application parts are moved towards each other at different speeds. Visible pilot light, coupled into the applicator, could also be used, for example, to determine the position of the light applicator.
The closure of the blood vessel after the light treatment presented here can be supported by additional secondary measures such as compression. In addition to thermal laser applications, this method can also be used for photodynamic applications. There is almost no risk of unwanted damaging of the vessel to be treated especially due to comparatively extremely low light power densities used, the avoidance of contact and the constant friction between applicator to be moved and catheter without be changed during the application of energy
Further Embodiments
[0084] Ideally, the light in the method described here is emitted on a circular basis and preferably over a particular length. This ensures a more even treatment of the blood vessel. In addition, a cylindrical irradiation over a length of approx. 0.5-5 cm can sensibly balance out lack of homogeneity in the vessel wall and/or irregularities caused by movement of the applicator.
[0085] In addition, this applicator may have a higher level of light emission at the proximal end of its irradiation area. This causes a higher level of energy to be given off at the proximal end of the irradiation area when the light applicator is withdrawn than at the distal end. This means that, when the proximal end passes by, the blood vessel wall section being passed by the light applicator quickly heats up from body temperature (approx. 37° C.) to treatment temperature (approx. 60-100° C.). When the distal applicator end passes by, the temperature of the blood vessel wall is not increased dramatically any further, but simply remains constant. This rapid preheating can increase the efficiency of the method as a whole (by minimizing the transport of heat and by changing the optical parameters during preheating).
Suitable wavelengths for the therapy light used in this method are in the visible to infrared range, especially because of the optical absorption and dispersion in the tissue between 500-2000 nm. The method can be optimized on the basis of an online temperature or tissue properties or geometrical measurement during irradiation or in breaks between irradiation in or on the surface of the application system, or even supported by regulating technology.
Advantages of the New Therapy Method Described Here
[0000]
The low-friction, even sliding of the light applicator in a type of catheter system during treatment makes it easier for the user to achieve an even treatment result.
Because the catheter remains in the blood vessel during treatment, a defined positioning (minimum distance/centering) of the light applicator is ensured, especially at bends.
With this method, it is possible to treat certain sections of the vessel or the blood vessel over the entire length to be treated several times over. This means that it is possible to achieve closure gently, through several applications of low doses of light or—if therapy monitoring through parallel diagnostic methods is possible—to optimize the treatment result during the intervention.
There is almost no possibility of creating primary thromboses. In particular, with this method, it is not possible to create a carbonized coagulation of blood on the light applicator itself, which could cause indirect thermal damage or even perforation of the blood vessel wall.
Because, with this method, the light-emitting area of the applicator is not in direct contact with the blood, the treatment is more even over the entire length of the blood vessel. The light-emitting area is not changed through any adhesion of blood and/or tissue to the outside of the application system for the entire duration of the treatment.
With this method, the catheter, which remains in the vessel until the treatment is finished, represents an additional safety factor for the method. If any incident occurs, such as damage to the applicator at its light-emitting area, the entire system can be retrieved without parts being left in the body of the patient.
DESCRIPTION OF THE FIGURES
[0094] FIG. 1 shows the positioning of the catheter system ( 2 ) and the light applicator ( 3 ) with light-emitting area ( 4 ) in the blood vessel ( 1 ). The light emitting area may be a part of or an extension of an optic fibre.
[0095] FIG. 2 shows schematically a possible introduction of the device of the present invention using a two step process (“principle a”) employing the Seldinger technique. Upon puncture with an access needle, a guide wire is inserted into the vessel through the access needle. The guide wire guides the catheter, which is inserted starting with the (open) distal end along said guiding wire. Upon positioning the catheter, the guide wire is removed and the light applicator is inserted into the catheter and used to apply energy. The light applicator may be movable within the catheter and is capable of emitting light through the catheter, e.g. also through the open distal end yet especially through the sheath of the catheter in a cylindrical manner. Upon finalizing the treatment, the light applicator may be removed from the catheter. Finally. the catheter is removed from the vessel.
[0096] FIG. 2 also shows the introduction of the device of the present invention using a one step process (“principle b”). The catheter itself is used as “guide wire” upon puncture with an access needle and guides the light applicator through the vessel. Here, both are inserted simultaneously. However, in accordance with the present invention, the light applicator may also be inserted subsequently to the insertion of the catheter. Upon positioning the catheter, the light applicator is used to apply energy. The light applicator is movable within the catheter and is capable of emitting light through the catheter, e.g. through the closed distal end and/or especially through the sheath of the catheter in a cylindrical manner. Upon finalizing the treatment, the light applicator may be removed from the catheter. Finally, the catheter is removed from the vessel.
[0097] Inserting the catheter with or without the light applicator may depend upon the rigidity needed. The catheter alone is more flexible, while catheter together with light applicator forms a more rigid unit.
[0098] FIG. 3 shows exemplary radiation profiles of the light applicator in use. Here, the light applicator is a cylindrical diffuser based on a conventional optical fibre 5 . The upper graph shows a homogeneous cylindrical radiation profile. The lower graph shows an inhomogeneous cylindrical radiation profile. The profiles can be created for example by the arrangement of different concentration of volume scattering layers (C 1 to C n , in the Figure) as desired.
[0099] The figure shows different scatter layers C1 to cn, each comprising a medium with scattering particles 6 ) which may be used to set up the radiation profile by coupling out a distinct portion of light.
[0100] The device in FIG. 3 also shows an embodiment, which comprises a closure 7 of the light applicator. Here, e.g. an ultrasound or x-ray label may be placed within the applicator yet outside the light-emitting region for not being absorbing.
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A light-based method of endovascular treatment, in particular, of pathologically altered blood vessels. Provided are a Method of Endovascular Light Treatment and a corresponding Endovascular Light Application Device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a rotary dobby for the operation of the heddle frames installed on a loom and a weaving loom and to a loom provided with such a dobby.
2. Description of the Related Art
It is known that in rotary dobbies the vertical movement of the heddle frames is provided by oscillating components that can be constituted, depending on the case, by connecting rod-arm assemblies or by roller-bearing arms; these oscillating parts are driven by actuating elements in the form of an eccentric gear in the first case or of a cam in the second one. These actuating elements are mounted on a main shaft of the mechanism that is actuated by an intermittent rotary movement and, at the time of each stoppage, as a matter of fact at all the half turns of the above-mentioned shaft, the reading-in device must interlock the actuating element either with the shaft, in order to drive the oscillating part, or with a stationary point in order to effect the angular immobilization of the latter; this interlocking must be effected at each of the heddles of the dobby, that is to say of the actuating unit associated with each heddle frame and depending on the design or pattern to be obtained on the loom during the weaving process.
This selective interlocking is generally obtained by means of a cotter or catch-shaped movable coupling element subjected to the action of two pivoting arms arranged on one and the other sides of the shaft in order to actuate this moveable element at its two stop positions, being each pair of pivoting arms controlled by the reading-in device of the dobby.
In patent application FR-A-2 540 524 was disclosed a rotary dobby for looms in which a plate joined to each heddle frame is comprised of two diametrically opposed notches suitable to interact with the catch of two pivoting arms that are controlled by the reading-in device. These two notches are of different shape because one of them must be relatively deep in order to provide the plate with a perfectly precise angular position and then ensure an adequate holding for as long as necessary. On the other hand, the other notch is of reduced depth and is provided with lateral walls which are wide open and that run parallel to the chamfers of the extremities of the sides of the catch of each pivoting arm, so that the arm's catch can be automatically driven with the rotation of the plate, without the actuating of the reading-in device upon the arm. In this second case, one talks about a "passive" engaging of the catch in the notch.
Tests have shown that such an arrangement functions in a satisfactory manner. In this known device, however, when, depending on the pattern of the loom that is being woven, it is not necessary to exert on the coupling pawl a force causing it to actuate, the tappet of the reading-in device must be deflected towards the arm of which the catch is in passive engagement with the notch of the plate diametrically opposed to it, which allows the actuating of the pawl. Thus, in approximately 50% of the cases, the arm that is in a passive engagement with one of the notches of the plate is actuated although this is not necessary for a good operation of the dobby of the invention.
An excessive energy consumption of the dobby, a high noise level and repeated mechanical stresses on the components of the dobby are elements that are certainly not beneficial for the functioning of the mechanism. In view of these repeated stresses, the dimensioning of the drive shafts, of the flanges and of the reading-in device's tappet gave rise to their high cost and considerable size.
SUMMARY OF THE INVENTION
This invention has the purpose of remedying these shortcomings with the aim of facilitating the construction of a rotary dobby operating with an optimal energy consumption and generating not much noise while its cost price is lower than that of the rotary dobbies of known design.
With this in mind, the present invention relates to a rotary dobby for a weaving loom that comprises at each of its shafts an oscillating element that is coupled to a heddle frame and connected to an actuating element loosely mounted on a main shaft of the dobby, a moveable coupling mechanism resting on a plate that is laterally solid with an actuating element, this moveable mechanism being subjected to elastic means to effectuate the angular connection of the plate with a disk firmly attached to the shaft, and two pivoting arms subjected to the action, on one hand, of the reading-in device and, on the other hand, to the action of the elastic means that function to engage the catches of the arms with one of the two binding surfaces of the plate. This dobby is characterized by the fact that when the arms are engaged with the binding surfaces, one of the arms is outside of the reach of an actuator belonging to the mentioned reading-in device.
Thanks to the invention, when the actuator or tappet of the reading-in device is deflected towards an arm that is out of reach, there is no physical contact between their respective surfaces, so that the arm and the actuator are not subjected to the impacts that could cause fatigue of their respective constituent materials. Furthermore, considering from a statistical viewpoint the multiple head shafts belonging to a dobby, one can count on that approximately 50% of them are in such a position that the arm positioned on the side of the coupling pawl must not be actuated so that, thanks to the invention, in approximately 50% of the cases no arm is displaced by the actuator. Thus, the present invention allows to anticipate a lower energy consumption of the dobby than for dobbies of the hitherto known design, in which at each half-turn of the main shaft one must systematically displace an arm for each heddle frame.
In accordance with an advantageous embodiment of the invention, the plate bears a radial extension defining a first binding surface, separated from the axis of rotation of the shaft at a distance that is greater than the distance separating from this axis of rotation a second binding surface on the plate, diametrically opposite to the first binding surface on the plate. Than to this aspect of the invention, the release from the bearing surface of the arm interacting with the first binding surface is carried out in a very simple manner, by making it rotate around its axis in such a manner that its drive rod is separated from the tappet or the actuator of the reading-in device. Thus, the invention takes advantage of the preexisting elements or components of the dobby in accordance with the invention, including those of the known dobbies, so that the invention can be fashioned in a very economical manner at the cost of slight modifications, that is to say, by increasing the distance of one of the binding surfaces with respect to the main shaft of rotation of each plate of the dobby.
In accordance with another advantageous aspect of the invention, the first binding surface is a passive binding surface of the plate whereas the second binding surface is an active binding surface controlled by the plate. Thanks to this aspect of the invention, the arm engaged with the passive binding surface is that which is free of the bearing surface of the tappet or actuator of the reading-in device.
In accordance with another advantageous aspect of the invention, the catch of each pivoting arm has an external bearing surface and an internal bearing surface, which bearing surface) have vertex angles of different values. Thanks to this aspect of the invention, the amplitude of the angular movement of each arm can be designed so that it is less than that which would be necessary if the bearing surfaces of the catches would interact respectively with the two binding surfaces, having heights that must be added up.
Lastly, the invention relates to a loom provided with a dobby as described above.
The invention will be better understood and its other advantages will be seen more clearly through the below description of two embodiments of a dobby in accordance with its principle, given only by way of example and making reference to the accompanying illustrations wherein:
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a schematic cross section of a dobby in accordance with the present invention;
FIG. 2 is a view in perspective showing in a disassembled state the essential constituting elements of one of the heddles of the dobby in accordance with FIG. 1;
FIG. 3 is a simplified cross section similar to FIG. 1, wherein the dobby is in a 180° shifted position with respect to FIG. 1;
FIG. 4 shows at an enlarged scale the catch of a pivoting arm and the notch of the plate associated with one heddle in a first binding position, and
FIG. 5 is a view similar to that of FIG. 4 with an arm interacting with a portion of the plate diametrically opposed to the one illustrated in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The dobby illustrated in FIG. 1 comprises a main shaft 1 driven by an intermittent rotary motion with stops every half turn. This shaft 1 is provided with a number of bearings, which number is equal to that of the heddle frames of the loom. On each bearing is loosely mounted an eccentric gear 2 that is laterally solid with a plate 3. On each eccentric gear 2 is loosely mounted the opening of a connecting rod 4 of which the free end is linked to a pivoting arm 5 which, thanks to a wire 6a, causes the vertical movement of the heddle frame 6 of the considered heald shaft, represented in a very schematic manner.
Between two adjacent eccentric gears 2, the groove shaft 1 bears a drive disk 7 that is firmly attached to it and presents on its periphery two radial notches 7a that are diametrically opposed to each other. These notches 7a are intended to selectively engage the terminal pawl 8a of a catch 8 mounted to a spindle 9 affixed to the lateral plate 3 of the corresponding eccentric gear 2. A spring 10 continuously releases the pawl 8a from the catch 8 towards the shaft 1.
The control of each catch 8 is carried out by means of two pivoting arms 11 linked to stationary spindles 12 running parallel to the shaft 1. Each arm 11, taken as a whole, had a square profile and is acted upon by a spring 13 in order to come to rest against a corresponding stationary stop 14. Each arm 11 is provided with a drive rod 15 susceptible to be selectively controlled by the tappet or actuator 16 belonging to the reading-in device of the dobby.
The tappet 16 is mounted on a pivot member 16' driven by a back and forth motion by pivoting around the stationary spindle 12 of one of the arms 11, by way of example, activated by a not represented cam mechanism. The pivot member 16' can also by designed in such a manner that it is linked to a spindle other than spindle 12. The back and forth motion or "hammer motion" of the pivot member 16' is indicated by the arrow F in FIG. 1. At each half turn of the shaft 1, the tappet 16 is displaced towards the rods 15 of the arms 11. By means of a control element 16", e.g., electromagnetic, is it possible to have the tappet 16 pivot on its coupling spindle or pivot 16a of the pivot member 16'. This drive is shown by the arrow F' in FIG. 1.
Opposite to its rod 15, each arm 11 is provided with a catch 17 susceptible to interact with two binding surfaces 18 and 19 arranged at the periphery of the plate 3. Thanks to the catches 17 and to the binding surfaces 18 and 19, the plate 3 can thus be immobilized in two positions separated by a 180° rotation of the plate 3 depending on whether the catch 17, shown at the left in FIG. 1, interacts with the surface 18 while the catch 17, shown at the right, interacts with the surface 19 (FIG. 1), or whether the catch 17, shown at the left, interacts with the surface 19 while the catch 17, shown at the right, interacts with the surface 18 (FIG. 3).
In the absence of an actuation of the tappet of the reading-in device, at the moment when each stop of the plate 1 is facing the catches 17, the springs 13 cause these catches to interact with the notch-shaped binding surface 19, which has the concomitant effect to angularly immobilize the plate 3, and with it the eccentric gear 2 and the connecting rod 4, and to control the catch 8 in its uncoupling by withdrawing its pawl 8a from the notch 7a into which it was engaged. This constitutes an "active" binding of the plate 3 with respect to the arm 11.
On the other hand, when an arm 11 is controlled by the tappet 16 against the corresponding spring 13, the catch 8, acted upon by the spring 10, tends to engage its pawl 8a into one or the other of the two notches 7a of the corresponding disk 7, thus causing the coupling between this disk and the eccentric gear 2 and therefore effectuating the control of the connecting rod 4 and of the heddle frame 6 with each 180° rotation of the shaft 1. In other words, in the position of FIG. 1, if the actuator 16 transmits an effective force of the tappet to the drive rod 15 of the arm 11 represented at the right, the corresponding catch 17 is released from the notch 9 and the plate 3 is driven 180° to a position in which the notch 19 interacts with the catch 17 of the opposite arm 11.
Further, in the position illustrated in FIG. 1, the binding surface 18 and the catch 17 of the arm, shown at left, interact so as to create an elastic means of immobilization of the plate 3 in its position. This elastic means of immobilization must be overcome when the plate 3 must be brought into rotation, that is to say when the pawl 8a engages with one of the two notches 7a of the disk 7. It can be considered that it is a matter of a "passive" immobilization of the plate 3.
The binding surface 18 is arranged on a radial extension 3' of the plate 3. The distance D 1 , separating the binding surface 18, that is to say, the extremity of the extension 3' from the axis XX' of rotation of the shaft 1 is greater than the distance D 2 separating the notch 19 from the axis XX'. When the catch 17 of the arm 11, positioned at the left in FIG. 1, interacts with the surface 18, it is driven out in a clockwise manner in FIG. 1, to such a point that its drive rod 15 is separated from the tappet 16, so that it is out of its reach.
The functioning is as follows: In the position of FIG. 1, if it is necessary for the catch 17 of the arm 11, located at the right in FIG. 3, to be released from the notch 19 in such a manner that the pawl 8a of the catch 8 is driven by the spring 10 towards a notch 7a, the tappet 16 is oriented towards the drive rod 15 of the arm 11, located at the right in FIG. 3, so that it can exert upon it a sufficient force to overcome the restoring force of the spring 13 to which it is linked.
On the other hand, if it is not necessary to disengage the catch 17 of the arm 11, located at the right in FIG. 3, from the notch 19, the tappet 16 is oriented by the control element 16" towards the arm 11, located at the left in FIG. 3. Since it is out of reach of the tappet 16, no impact takes place between this tappet 16 and the arm 11, located at the left in FIG. 3, so that no noise is generated, and that the metal constituting the arm 11 and/or the tappet 16 is not subjected to fatigue.
It must be noted that it can be provided that the arm 17, located at the left in FIG. 1, will not be activated in this position because it interacts with a passive binding of the plate 3 in this position. In other words, it is not necessary to act upon the arm 11, located at the left in FIG. 1, because it is automatically released when the plate 3 is caused to rotate.
In FIG. 3, the plate 3 is shown after a 180° rotation with respect to its position in FIG. 1. In this position, the arm 11, located at the right in FIG. 3, is driven out by pivoting around its spindle 12 in the counter-clockwise direction, so that it is out of reach of the tappet 16. As above, if it is not necessary to act upon the arm 11, located at the left in FIG. 3, the tappet 16 is oriented towards the arm 11 located at the right in FIG. 3, and can be driven by the back and forth or "hammer" motion transmitted by the flange 16' on which it is mounted, without this motion causing a contact between the actuator 16 and one of the arms 11.
Pursuant to the known state-of-the art, it is possible to see to it that one only flange 16' can bear the assembly of the actuators used for each of the heddles of the dobby by imparting on them a back and forth motion, illustrated by the arrows F in FIGS. 1 and 3. Only the rotary drive motion, illustrated by the arrows F' in FIGS. 1 and 3, must be effectuated in an individual manner by the electromagnetic mechanisms 16" upon the actuators 16 of the dobby in accordance with the invention.
In accordance with an advantageous, but not mandatory, aspect of the invention, the geometry of the catches, that are identical since they can selectively interact with each of the binding surfaces 18 and 19, is designed in such a manner that each of them has an external bearing surface 20 and an internal baring surface 21, that are suitable to interact with the binding surfaces 19 and 18, respectively.
The external bearing surface 20 has a geometry that is adapted to fit against the surfaces delimiting the notch 19. The vertex angle of this bearing surface 20 is reference as α. An internal bearing surface 21 is defined sunken in the catch 17 and its vertex angle is reference as β. The geometry of the bearing surface 21 is designed so that it is suitable to fit against the external surface of a tooth 18a belonging to the binding surface 18, as illustrated in FIG. 5.
In can be noted that the vertex angle β is greater than the vertex angle α, so that it is easier to disengage the catch 17 when it interacts with the surface 18 than when interacting with surface 19, which must be related to the operating method of the dobby in accordance with the invention, in which the binding obtained with the surface 18 is "passive" while the binding obtained with the notch 19 is "active".
The bearing surface 21 has a height H 2 that can be different than the height H 1 of the bearing surface 20. It can be noted in particular that the internal bearing surface 21 is contained inside the width of the external bearing surface 20, that is to say, the height H 2 is less than the height H 1 .
In accordance with a not shown variant of the invention, its design can be such that the vertex angle of the internal bearing surface 21 has a lower value than the vertex angle of the external bearing surface 20. This configuration can be used when an effective or "active" binding must be obtained for a tooth corresponding to the tooth 18 of FIG. 5, when the release of the bearing surface 20 must be facilitated. This configuration can be used when the binding surface provided with a tooth is in the proximity of the extremity of catch 8.
A loom 100 provided with a dobby of above described type can operate faster, with less energy consumption, with less wear and tear and making less noise than a weaving loom provided with a dobby of previously known type.
Furthermore, it must be understood that the above description as given only by way of example and that it does not limit at all the scope of the invention, from which one would not deviate by replacing the described design details with equivalent ones. It can be especially conceived that the invention is susceptible to be used for dobbies in which the actuating elements are not constituted by eccentric gears linked to connecting rods but by cams shaped to control roller-bearing arms coupled to the heddle frames 6. In the same manner, and although the tilting catches seem to be the most advantageous design for the movable coupling elements, one can resort to mechanisms of keys or pins having a radial displacement. Also, the movable coupling element can be constituted by several components, such as, for example, two hooks, two clasps or two keys or pins.
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A rotary dobby which includes pivoting arms which are moveable with respect to a plate connected to an element for actuating a heddle frame in controlled response to a reading-in device and wherein the pivoting arms include catches which are engageable with respect to first and second spaced binding surfaces of the plate in such a manner that one of the arms is spaced from an actuator associated with the reading-in device when the pivoting arms are engaging the binding surfaces.
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BACKGROUND OF THE INVENTION
The invention relates to milling machines which can be used to machine both eccentric end faces and circumferential faces, e.g. peripheral faces.
A typical workpiece having such faces is a crankshaft, for which reason the following text always refers to a crankshaft, without limiting the possible workpieces to this alone.
For crankshafts, metal-removing machining is known both with external-milling machines and with internal-milling machines, that is to say by means of a milling cutter which annularly surrounds the crankshaft and has inwardly directed teeth. In this case, the axis of rotation of the milling cutter lies parallel to the longitudinal axis of the crankshaft.
In this case, the crankshaft is held at its ends, that is to say on one sides at its end flange and on the other side at its end journal, centrically, that is to say on the centre axis of its centre bearings, in chucks on both sides.
In a known solution, the crankshaft does not move during the machining, and thus the chucks are not driven by a spindle head. For machining of the crankpin journals, the annular internal-milling cutter rotates, on the one hand, about its own centre point in order to generate the cutting speed and, on the other hand, on an orbit about the centre of the crankpin journal to be machined, in order to mill the peripheral face thereof. Web end faces and web circumferential surfaces can also be machined in this manner, as long as the radius of curvature is smaller than the radius of the circuit of the cutting edges of the internal-milling cutter. With the crankshaft stationary, the internal-milling cutter can be displaced in a defined manner in the X- and Y-directions.
The mounting which annularly surrounds the internal-milling cutter is extremely stable, but has a relatively wide extent in the Z-direction, for which reason, for short crankshafts, the simultaneous deployment of two internal-milling cutters axially spaced apart on the same crankshaft can be problematical.
It is also known in that solution to rotate the crankshaft slowly during the machining, that is to say to be able to drive at least one of the chucks in a defined manner by means of a spindle head and to set its rotational position. This realisation of the C-axis for the workpiece makes it possible to dispense with the movement of the tool slide rest in the Y-direction, so that therefore only the tool slide rest for the internal-milling cutter merely comprises a lower slide for movement in the Z-direction and an upper slide for movement in the X-direction.
Furthermore, external-milling machines are known, in which the milling units—in addition to the displaceability in the Z-direction—were displaceable in a defined manner in the X-direction, and the chucks for the crankshaft were held in one or two spindle heads. Realisation of the C-axis on the workpiece meant that the external-milling cutter was guided on in a defined manner in the X-direction during the machining of eccentric surfaces. However, the machining of eccentric surfaces did not entail two or more external-milling units, operating independently of one another, being deployed on the same crankshaft. This was only possible when machining the eccentric surfaces, e.g. the centre-bearing journals.
In the case of the known milling machines, work is carried out with a conventional, negative cutting-edge geometry and cutting speeds on workpieces made of grey cast iron (GGG60-GGG80) of at most 160 m/min. As a result, very high cutting forces are introduced into the workpiece, for which reason it is also necessary as a rule to support the centre of the workpiece by means of steady rests, etc. A further drawback consisted in the fact that a high proportion of the process heat was introduced both into the workpiece, and thus also into the tool, and only a small proportion was dissipated via the chips.
SUMMARY OF THE INVENTION
a) Technical Object
It is therefore the object of the invention to provide a milling machine for machining both eccentric end faces and circumferential faces which, despite a simple design, ensures a short machining time.
b) Solution to the Object
This object is achieved by means of the characterizing features of claim 1 . Advantageous embodiments result from the subclaims.
Owing to the C-axis of the workpiece and the resultant possible defined, but relatively slow rotation of the workpiece of generally less than 60 revolutions/minute, frequently only 15-20 revolutions/minute, it is sufficient that the tool slide rests has to be able to move the tool, generally an external-milling cutter, in a defined manner, in addition to in the Z-direction, only also in the X-direction.
This rotation of the workpiece is so slow that any imbalances of the workpiece which may arise do not have a disadvantageous dynamic effect on the result of the machining.
c) Advantages
The short machining time is achieved due to the fact that, despite the rotation of the workpiece, e.g. of the crankshaft, two tool units can work, independently of one another, on eccentric surfaces whose rotational positions do not coincide, which effect is only possible by means of a machine control system which controls the independent tool slide rests as a function of the position and rotation of the workpiece, it preferably being possible to specify optimisation targets, such as for example the chip thickness or the cutting speed.
In this case, for a specific workpiece it is possible even before machining to calculate, for each instant of the machining, the rotational position, direction of movement and speed of the workpiece, the rotational speed of the milling cutters, the X-position and direction of movement and speed of movement of the milling cutters, etc., and to store these parameters in a working program, for example as a table of settings for various states of the machining, which program can then be executed by the machine control system.
d) Further Configurations
Another possibility consists in taking into account at the same time the current actual position and actual movement of the workpiece during the machining and, as a function of these, controlling the tool slide rests. However, this is considerably more complex in terms of the sensor technology and the control outlay.
Owing to the relatively low rotational speed of the workpiece, slip errors, that is to say deviations between the desired and the actual position, during the movement of the workpiece are relatively low.
In order also to achieve this on the tool side, for example when using a side-milling cutter, the diameter is designed to be larger than would be necessary for the penetration depth for milling the big-end journal of a crankshaft. This enlargement of the side-milling cutter results in a likewise relatively low rotational speed of the milling cutter, so that in addition the rotational speed of the tool can be constantly adjusted with slip errors which are only negligibly low.
For machining a passenger-car crankshaft with a throw of 10-15 cm, the diameter of a side-milling cutter used for this purpose is about 800 mm. This also results in thermal advantages, since a relatively long time is available for cooling between two successive deployments of one and the same cutting edge of the milling cutter.
If suitable cutting materials and cutting-edge geometry are used, cutting speeds of 800 m/min and even significantly more can be achieved, and in addition the machine does not need any cooling lubricant at the machining location, since dry milling is possible, in particular with a positive tool geometry.
Instead of a linear movement of the milling cutter in the X-direction, it is also possible to pivot the milling cutter about an axis parallel to the Z-axis, which is necessary in particular when using a slotting cutter, the axis of rotation of which is arranged perpendicular to the longitudinal axis of the crankshaft. The cutting edges on the front end face of a slotting cutter of this kind machine circumferential faces, that is to say, for example, the peripheral faces of the crankpin journals of a crankshaft, and its cutting edges on the circumferential face machine the side faces, for example the web end faces.
The use of a side-milling cutter, in which therefore cutting edges are arranged on its circumferential region and/or in the transition region between the circumferential face and the end face of the cylindrical base body, is to be preferred to an internal-milling cutter, since even with a width of the side-milling cutter in the Z-direction of only about 20-25 mm and a diameter of about 800 mm such a side-milling cutter is sufficiently stable to be mounted free on only one side. If two side-milling cutters which act on the workpiece from the same side but are axially spaced apart are used, these two side-milling cutters can thus be mounted driveably on mutually remote sides on their respective slide rests, so that these two side-milling cutters can in theory be moved towards one another in the axial direction as far as until their cutting edges make contact on the end side.
In the case of an internal-milling cutter mounted and surrounded along the outer circumference, it is not possible to achieve such a narrow design in the Z-direction and to bring two milling units so close together.
Moreover, cylindrical external-milling cutters are easier to equip, and also to adjust and exchange, which is an extremely important factor in view of the fact that in currently possible processes the idle times and non-cutting times of a machine compared to the cutting times are becoming ever more significant.
The cutting edges in milling cutters of this kind are usually positioned along the circumference as screwed-on throw-away cutting-tool tips. In principle, a distinction is made here between three different types cutting tip with regard to their use: The so-called web-cutting tip machines end faces, that is to say, for example, web side faces, the so-called journal-cutting tip machines circumferential faces, that is to say, for example, the peripheral face of a bearing journal of a crankshaft or the outer circumferential contour of a web, possible peripheral faces being any desired convexly curved contour and plane, for example surfaces arranged tangentially with respect to the Z-axis and even concave surfaces, as long as their radius of curvature is greater than the radius of the side-milling cutter used.
The milling of planar surfaces as fastening surface for additional weights or for balancing operations is a particularly important advantage of external milling over internal milling.
Furthermore, to produce the so-called undercut, that is to say a recess at the transition between the peripheral face of the journal and the end-side web end face, special undercut-cutting tips are present.
It is possible, for example, to arrange only journal-cutting tips on a side-milling cutter, which provides the possibility of additionally displacing such a side-milling cutter in a defined manner in the Z-direction during the machining, and thus of being able to mill bearing journals of virtually any desired width using a narrow side-milling cutter without annularly encircling machined shoulders. In this case, the undercut has to be produced by a separate milling cutter.
Another possibility consists in arranging the undercut-cutting tips directly on one circumferential edge, or even on both circumferential edges, of the milling cutter which bears the journal-cutting tips, and thus in milling the undercut together with the peripheral face of the journal. If the two-sided undercut-cutting tips are arranged on a milling cutter, the milling cutter corresponds to the finished axial length of the bearing location, that is to say only to a specific workpiece to be produced. If one milling cutter is used for the left-hand undercut and the left-hand half of the peripheral face of the journal and another milling cutter is used for the right-hand half of the journal face, it is possible to produce variable bearing widths in the Z-direction using one and the same pair of side-milling cutters by means of variable intersection in the centre.
The web-cutting tips are mostly arranged on a separate side-milling cutter, and again preferably on both end faces of the side-milling cutter, in order to be able to machine side faces which are directed both in the +Z and in the Z-direction. Arrangement on a separate side-milling cutter is sensible, since relatively large volumes are to be removed along the web side faces and thus these web-cutting tips wear more quickly than, for example, the journal-cutting tips or the undercut-cutting tips.
The milling machine according to the invention may, for example, comprise only two milling units, which can be moved independently of one another and which work on the crankshaft from approximately the same side, merely being spaced apart axially. As a rule, the movement in the X-direction will be directed obliquely from above or even perpendicularly towards the crankshaft, in that either the bed of the milling machine itself or at least the transverse guide along which the upper slide runs on the lower slide of the tool slide rest is already positioned either obliquely or steeply.
However, it is also possible for two independently operating tool units to work on the workpiece from opposite sides or else with transverse movements directed towards one another in the manner of a V.
If, in these cases, in addition a plurality of tool slide rests are arranged one after the other, spaced apart in the Z-direction, it is also possible for four or even more tool units to work simultaneously on one and the same workpiece.
In addition, a single tool unit may have a multiple tool, that is to say, for example, two side-milling cutters which are spaced apart in the Z-direction but can only be moved synchronously with one another, for example as a tandem tool. This is useful in particular if the crankshaft to be machined has two crankpin journals which are aligned with one another, such as for example the crankshafts of four-cylinder in-line engines. However, since multiple tools of this kind are coupled in terms of their transverse movement and rotation, they are only to be considered as a single tool unit.
In the case of the double-sided driving of the crankshaft held in the chucks, the double-sided spindle drives are preferably electrically synchronised.
Even when machining the workpiece using a machining program worked out prior to the machining and stored in the machine control system, this machining program can be corrected subsequently on the basis of the measurements of the first finished parts:
It is known that the result of the machining is in practice slightly out-of-round, despite the machining of a precise cylindrical surface, owing to the deflection of the crankshaft in the transverse direction by the cutting forces. It is attempted to compensate for this by milling a theoretically out-of-round contour which, owing to the deflection of the crankshaft in the transverse direction which occurs in practice, then results in a very close approximation of a completely cylindrical peripheral face. Since this in theory can only roughly be taken into account when establishing the machining program, the machine control system includes the possibility, after producing the first samples, of inputting the out-of-roundness still present with regard to size and angular position into the control system using an input panel, the control system them automatically, and preferably for each bearing journal individually, if necessary even beyond its axial length, adjusting the transverse movements of the milling units differently for the respective angular position of the workpiece.
If two milling units which are drivable and operate independently of one another are machining different, eccentric surfaces for machining on one and the same rotatable and drivable crankshaft, and it is intended to maintain an optimum value or range for the chip thickness, under certain circumstances it is only possible to achieve the desired maximum cutting speed, for example the cutting speed of HS milling, at one machining point.
In order to keep the chip thickness or average chip thickness within the optimum range at the other machining points, under certain circumstances the rotational speed of the milling cutter has to be reduced there, and consequently so too does the cutting speed. For this reason, at the start of the journal machining the milling cutter is not moved immediately radially as far as the desired dimension, but rather is moved slowly as far as the radial desired dimension while the crankshaft is rotating slowly, over the course of a rotation of the journal to be machined of 30-90, preferably of 50-70°. As a result, the stipulation with regard to the chip thickness is observed even at the beginning of the machining of a bearing journal, and inadmissibly high transverse forces are not introduced into the workpiece at the start of the machining. After reaching the radial desired dimension, it is necessary to execute a complete cycle of the journal surface, preferably about 100° circumferential surface, in order to achieve an optimum machining result.
If there is no optimum value for the chip thickness with regard to the life-cycle performance of a tool, the independent tool units would be optimised with a view to maximum cutting speed. These laws, which were determined primarily for machining grey cast iron (GGG60-GGG80), may under certain circumstances also be valid for other workpiece materials, such as steel, for which other groups of cutting materials are also employed.
The additional use of a positive tool geometry instead of the negative tool geometry which was previously used in milling and which nevertheless, primarily in connection with the low average or maximum chip thicknesses, leads to a sufficient tool life of the cutting means, in turn results in a reduction in the cutting forces and consequently also in a reduction in the driving powers required for the tool, which powers, for the size ratios indicated, is only about half to one third of the power required for internal milling or rotary turn broaching. In addition to the lower energy costs, this also minimises the waste heat problems of the drives, which always have a negative effect on the overall machine and the machining result.
The high-speed milling according to the invention may in this case be carried out, in particular, not only on the unhardened workpiece but also on the hardened (e.g. Rockwell hardness H RC of 60 to 62, in particular fully hardened) workpiece. In this case, the cutting material preferably used is cermet or polycrystalline boron nitride (PCB), and in the case of the latter in particular cubic boron nitride (CBN). In this case, it is preferable firstly to sinter a carbide cutting tool tip as usual which, however, has cavities in the cutting-edge area, e.g. in the tool face open towards the cutting edge. CBN powder is placed in these cavities in the base body and is then sintered.
It is not only the noses of throw-away cutting tool tips which can be reinforced in this manner, but also an entire cutting edge can be reinforced by arranging a plurality of CBN pallets next to one another along a cutting edge, or else by providing a bar-shaped CBN insert. It is consequently also possible to machine unhardened steel or cast iron, even by milling.
These cutting materials can also be used without cooling lubricant, that is to say dry, thus saving on disposal costs and environmental problems.
It is thus possible even as early as during the metal-removing machining to eliminate the distortion of the workpiece which due to the hardening process occurs in conventional production (metal-removing machining prior to hardening). Since, when using high-speed milling and in particular when using high-speed milling on the hardened workpiece, it is possible to achieve surface qualities which are acceptable as the final state of the workpiece, it is consequently possible to dispense with at least the rough-grinding operation altogether.
When machining the journal and web surfaces on crankshafts which consist of cast iron or steel and are machining in the unhardened state by means of an external circular-milling cutter, in particular by means of a disc-like milling cutter with cutting edges on the circumferential region, it has proven particularly advantageous to observe the following parameters:
Cutting speed during the roughing machining: at least 180, preferably 250-600 m/min,
Cutting speed during the finishing machining: at least 200, preferably 300-800 m/min,
Chip thickness: 0.05-0.5 mm, in particular 0.1-0.3 mm.
The tool used here is generally a disc-like tool body driven in rotation and having inserted throw-away cutting-tool tips. In this case, the configuration of the cutting-tool tips differs depending on their intended purpose (machining of the end faces on the webs, machining of the peripheral surfaces on the journals of the main bearing point and big-end journal points, production of the undercuts at the transition between peripheral surfaces and end faces) and they are also positioned differently with respect to the tool carrier or to the workpiece:
Web-cutting tip
Undercut-
Journal-cutting
cutting tip
tip (face-
cutting tip)
Basic
K20-K25
K15
K10-K15
material
Coating
TiCN + Al 2 O 3 +
TiN
TiCN + Al 2 O 3 +
TiN or
TiN or
TiN + TiCN +
TiN + TiCN +
Al 2 O 3 + TIN or
Al 2 O 3 + TIN or
TiN + Al 2 O 3 +
TiN + Al 2 O 3 +
TiN
TiN
from/to
esp.
from/to
esp.
from/to
esp.
Total
3-15
10-12
2-8 μm
3-5 μm
2-8 μm
3-5 μm
thickness
μm
μm
of the
coating
γ p
+1° . . .
+5°
+4°
+4°
+2°
+2°
+8°
γ f
−4° . . .
−1°
+1°
+1°
+2°
+2°
+4°
γ n
+5° . . .
+9°
+9°
+9°
+9°
+9°
+14°
λ s
+2° . . .
+5°
+5°
+5°
+3°
+3°
+7
κ
about
+5°
+4°
—
+2°
Cutting
0.01-0.05
about
about
about
about
about
edge
mm
0.02
0.02
0.02
0.02
0.02 mm
rounding
mm
mm
mm
mm
(CRE)
Nose
1.2-2.0
1.6 mm
1.6 mm
1.6 mm
—
—
radius R
mm
Length
min.
15.9
15.9
15.9
12.7
12.7 mm
10 mm
mm
mm
mm
mm
Height
min.
12.7
12.7
12.7
12.7
12.7 mm
10 mm
mm
mm
mm
mm
Thickness
min. 3
6.35
5.55
5.55
4.7 mm
4.7 mm
mm
mm
mm
mm
Data with regard to the tool body:
Width of
23 mm
—
13 mm (split)
cut
to 22 mm
(complete)
Nominal
e.g. 800 mm
e.g. 800 mm
e.g. 800 mm
diameter
Pitch
3.6°
5.5°-7.5°
5.5°-7.5°
angle from
cutting
edge to
cutting
edge
Pitch
25 mm
35-50 mm
35-50 mm
spacing
from cut-
ting edge
to cutting
edge
Number of
e.g. 200
e.g. 120
e.g. 120
cutting
(split) to 200
(split) to 200
tips
(complete)
(complete)
Data on the basic material relates to the known ISO application groups, in which:
K10: consists of 94.2% tungsten carbide (TC), 5.5% cobalt (Co) and 0.3% . . . (Ta/C)
K20: consists of 93.2% TC, 6% Co and 0.6% Ta/C and 0.2% titanium carbide (TiC)
The flexural strength is 1900 N/m 2 for K10 and 2000 N/m 2 for K20.
In the coatings specified, the individual compounds are applied in layers one after the other in the sequence specified from the inside outwards.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment in accordance with the invention is described in more detail by way of example below, with reference to the figures, in which:
FIG. 1 a: shows a front view of the milling machine,
FIG. 1 b: shows a side view of the milling machine in accordance with FIG. 1 a,
FIG. 2 : shows a side view of another milling machine,
FIG. 3 : shows a side view of a different solution,
FIG. 4 : shows a front view with a tandem tool,
FIG. 5 : shows a side view with a slotting cutter, and
FIGS. 6 a and 6 b: shows detailed illustrations of side-milling cutters and the machining locations on a crankshaft.
FIG. 7 : shows a schematic depiction of climb-cutting external milling on a crankshaft journal,
FIG. 8 : shows a schematic depiction while simultaneously machining two different crankpin journals,
FIG. 9 : shows detailed depictions of two different machining points,
FIG. 10 : shows a curve of motion during the machining of a journal,
FIG. 11 : shows a depiction of the curve of motion during the milling of a journal,
FIG. 12 : shows a schematic depiction of the wedge of the tool,
FIGS. 13 and 14 show defined planes in the tool reference system,
FIGS. 15 and 16 show the angular position of the cutting edge in the tool reference system, using the example of a turning tool for plain turning (FIG. 15) and face turning (FIG. 16 ).
FIG. 17 : shows a section through a milling cutter head,
FIGS. 18 a- 18 f: show sections through the tool of the milling cutter head in accordance with FIG. 17,
FIG. 19 a: shows the insert of a web-cutting tip, viewed in the Y-direction,
FIG. 19 b: shows the insert of a journal-cutting tip, in the Y-direction of viewing,
DESCRIPTION OF THE PREFERRED EMBODIMENT
The milling machine illustrated in FIGS. 1 a and 1 b comprises a bed 20 with a chip trough 34 and a chip conveyor 45 accommodated therein. Two spindle heads 23 , 24 , which are spaced apart in the Z-direction and are directed towards one another, are positioned above the chip trough 34 , at least one spindle head 24 being displaceable in the Z-direction.
The spindle heads in turn bear chucks 21 , 22 , which are directed towards one another, can be driven in rotation and are electronically synchronised with one another in terms of their rotation.
A crankshaft 1 is chucked in between the two chucks 21 , 22 , which crankshaft is chucked by the chuck 21 on its end flange and by the chuck 22 on its end journal, that is to say on the centre axis MA of the crankshaft 1 , which thus coincides with the spindle-head axis. The belt surfaces, that is to say the circumferential faces on the end-bearing flange and on the end-bearing journal, have been rough-machined, in particular rough-machined with the removal of metal, and in addition corresponding stop faces have been rough-machined on the crankshaft for the purpose of inserting the crankshaft into the chucks in a defined rotational position.
Since the spindle heads 23 , 24 not only drive the crankshaft in rotation but are also able to set its rotational position (C-axis formed), the crankshaft 1 chucked therein can at any time during the machining be brought into the desired rotational position, and moreover at a defined speed.
Viewed in the direction of FIG. 1 a, Z-guides 33 are arranged on the bed 20 of the milling machine, behind the chip trough 34 and rising obliquely backwards out of the latter, on which Z-guides the lower slides 29 , 30 , which can be seen in FIG. 1 a, of the tool slide rests 25 , 26 can be displaced in the Z-direction.
On each of the lower slides 29 , 30 there runs an upper slide 27 , 28 which in each case supports a side-milling cutter 5 , 6 such that it can be driven in rotation about an axis parallel to the Z-axis.
The upper slide 27 , 28 can be moved from above in the X-direction onto the centre axis MA at a relatively steep gradient, at an angle of less than 45° to the perpendicular. The X-guides between upper slide 27 , 28 and the lower slide 29 , 30 here preferably coincides with the connection of the centre points of the side-milling cutters 5 and/or 6 and the centre axis MA.
In order to be able to use such a milling machine with an externally toothed side-milling cutter to machine the circumference of a crankpin journal H 1 , H 2 over the entire circumference, the crankshaft 1 chucked on the centre axis MA must complete at least one full revolution during the machining.
As can best be understood with reference to FIG. 1 a , during the rotation of the crankshaft 1 the side-milling cutters 5 , 6 which are simultaneously in use at different machining locations are constantly guided on in the X-direction with the aid of the tool slide rests 25 , 26 .
As will be explained in more detail later, the movements of the two tool slide rests 25 , 26 are thus indirectly dependent on one another, in that they depend on the rotation of the crankshaft which they are both machining and the geometry of the eccentric surfaces to be machined.
If in the process it is intended to carry out optimisations to the machining by means of these several slide rests which can be controlled independently of one another, for example with regard to a specific chip thickness, the side-milling cutters 5 , 6 not only move differently in the X-direction but also rotate largely with different, constantly adjusted rotational speeds.
The milling cutters 5 , 6 , and also their slide rests 25 , 26 and the machine control system which controls the joint rotation of the spindle heads, i.e. of the crankshaft 1 , can additionally be recorrected by correction values using an input panel 36 on the machine, on the basis of the results, determined in practice, of the machining of the first components of a series of workpieces.
In FIG. 1 b , the tool slide rests 25 , 26 , and thus also the directions of movement of the milling cutters 5 , 6 and of the upper slides 27 , 28 , are aligned one behind the other in the direction of viewing.
By contrast, FIG. 2 shows a different configuration of the machine in which, by contrast to FIG. 1 b , the slide rests 25 , 26 , which are of similar design, are arranged in mirror-image fashion with respect to a centre plane ME, namely the vertical plane through the spindle-head axis. The directions of movement of the milling cutters 5 , 6 in the X-direction towards the workpiece are thus positioned in a V-shaped manner with respect to one another.
Owing to the relatively large diameter of the milling cutters 5 , 6 , it is here possible for the milling cutters 5 , 6 to operate simultaneously at different axial positions of the crankshaft, and in addition, in the direction of viewing of FIG. 2, the same tool slide rests 25 ′, 26 ′ may again be arranged behind the tool slide rests 25 , 26 , axially spaced apart. The fact that four side-milling cutters 5 , 5 ′, 6 , 6 ′ can then machine the crankshaft simultaneously permits optimally short machining times for crankshafts and similar parts.
Viewed in the same direction as FIG. 1, namely in the Z-direction, FIG. 3 shows another machine design, in which the slide rests 25 , 26 act on the workpiece from opposite sides. The directions of movement of the two side-milling cutters 5 , 6 are in this case on a line which runs through the spindle-head axis and are thus inclined just as much with respect to the perpendicular as the solution in accordance with FIG. 1 b. On the inclined bed, one slide rest 25 is situated above the spindle heads 23 , 24 and the other slide rest 26 is situated below the spindle heads 23 , 24 .
In this machine configuration too, in the direction of viewing of FIG. 3, identical slide rests may again be arranged behind the slide rests 25 , 26 , axially spaced apart, so that here too more than two, for example four or even six, milling cutters, which can be controlled independently of one another, can act on the workpiece.
FIG. 4 shows an illustration similar to that of FIG. 1 a, but in which three side-milling cutters can be seen. However, two of the three side-milling cutters are coupled together to form a multiple tool 42 , in that the two side-milling cutters, which are assigned to the tool slide rest 26 , are connected to one another in an axially spaced but rotationally fixed manner and are driven jointly by this slide rest 26 . It is thus possible to machine simultaneously machining locations which are aligned in the Z-direction, for example the second and third big-end journals of a crankshaft for a four-cylinder in-line engine.
The machine shown in FIG. 4 thus has three side-milling cutters, but only two milling units which can be driven independently of one another.
FIG. 5 shows a side view of a milling machine similar to that of FIG. 2 . Here, the slide rest 25 is of identical construction to that in FIG. 2, that is to say it is equipped with a side-milling cutter 5 which can be driven in rotation about an axis which is parallel to the Z-direction, i.e. to the spindle-head axis.
In this case, the centre point of the side-milling cutter 5 moves in the X-direction, that is to say parallel to the X-guides between lower slide 29 and upper slide 27 , on a plane which runs above the spindle axis. This results in a more compact structure of the milling machine owing to the tool slide rest being reduced in height.
In contrast to this, the tool slide rest 26 , which like the slide rest 25 comprises a lower slide 30 and an upper slide 28 , bears a slotting cutter 37 , the axis of which runs transversely to the spindle-head axis. This slotting cutter 37 is mounted such that it can pivot in the upper slide rest 28 about an axis which is parallel to the Z-direction, that is to say to the spindle-head axis. As a result, it is possible to machine eccentric peripheral faces, for example to machine a crankpin journal of the centrically chucked crankshaft, in that during the slow rotation of the crankshaft the slotting cutter 37 is constantly guided on by pivoting with respect to the upper slide 28 and the traversed X-direction of the upper slide 28 with respect to the lower slide 30 .
Instead of the traversing movement of the slotting cutter 37 with the upper slide 28 in the X-direction, an additional pivoting, i.e. virtually a pivoting of the upper slide 28 with respect to the lower slide 30 , is also possible for compensation in the X-direction.
The machine depicted in FIG. 5 may, instead of being fitted with side-milling cutters and slotting cutters, also be equipped only with slotting cutters; this, incidentally, also applies to all other machine designs in accordance with the present invention.
FIG. 6 shows the surfaces which are typically to be machined on a crankshaft and the corresponding fitting of the base bodies 5 a, 6 a, 7 a of the side-milling cutters 5 , 6 with exchangeable cutting tips:
In FIG. 6 a , the web-cutting tips 39 for machining web side faces 3 are arranged on both end faces of the cylindrical base body 6 a of a side-milling cutter 6 , the web-cutting tips 39 obviously also protruding radially beyond the base body 6 a.
Due to the arrangement of the web-cutting tips on both sides of the base body 6 a , it is possible to machine both left-hand and right-hand web faces 3 and 3 ′.
The arrangement of the web-cutting tips 39 on their own base body 6 a is to be recommended, since owing to the high volume of metal removed from the web side faces 3 , 3 ′ these tips wear and have to be exchanged more quickly than, for example, the journal-cutting tips 40 . In FIG. 6 a , the latter are arranged on the circumferential face of a cylindrical base body 5 a of a side-milling cutter 5 in two axially spaced apart paths which overlap in the Z-direction and on the respective outer side also protrude in the Z-direction beyond the base body 5 a.
With such a side-milling cutter 5 which is exclusively fitted with journal-cutting tips 40 , only peripheral faces, for example the journal face 16 , are machined. Such a side-milling cutter 5 in accordance with FIG. 6 a can also be used—by means of an additional controlled displacement of the side-milling cutter 5 in the Z-direction—to machine a journal face 16 which is significantly wider in the Z-direction than the width of the side-milling cutter 5 . Due to the spiral machining path, annular shoulders between axially spaced-apart machining areas of a journal face 16 are avoided.
FIG. 6 b shows another solution. In this figure too, the web-cutting tips 39 are arranged on their own base body 7 a of a milling cutter. However, two separate side-milling cutters 5 , 6 for the left-hand and right-hand halves, respectively, of the journal face are provided for machining the journal face 16 and the undercuts 15 which adjoin the latter on both sides:
In this case, journal-cutting tips 40 which are in each case arranged on the circumference are situated on the base body 5 a and/or 6 a, while undercut-cutting tips 41 for producing the undercut 15 or 15 ′ are arranged on the end face of the base body, i.e. for the right-hand half in the +Z-direction and for the left-hand half in the −Z-direction. Obviously, in this case the undercut-cutting tips 41 again protrude radially beyond the base body 5 a and/or 6 a. The machining width of the two milling cutters 5 , 6 in the Z-direction is in this case so great that in the centre of the journal the machined areas overlap. In order to avoid an annular shoulder here, in this case the journal-cutting tips 40 are designed to fall off slightly towards the centre of the bearing journal, i.e. they are chamfered or even rounded, in order in the centre of the bearing location to produce only a rounded elevation instead of a sharp shoulder.
The undercut-cutting tips 41 , which are not shown in FIG. 6 a, are in this figure arranged on a separate milling cutter, in order to produce the undercuts 15 , 15 ′ separately.
In the direction of viewing of the Z-axis, FIG. 7 shows the fundamental situation for the machining of a circumferential surface, for example of the journal of a crankshaft, but also of an out-of-round circumferential surface, by means of external milling. An enlarged illustration of the machining point is depicted in the right-hand part of FIG. 7 .
The workpiece is intended to be machined from the larger base dimension to the smaller final dimension.
In this case, the cutting edges S, only one of which is drawn in, protrude radially beyond the tool body, in order to be able to effect this abrasion. The tool body is in this case displaceable in a defined manner in the X-direction and rotates anticlockwise. Since the milling is intended to take place on a climb-cutting basis, the workpiece rotates in the clockwise direction, so that at the machining point tool and workpiece are moving in the same direction.
As shown by the enlarged depiction, the new cutting edge S will produce a chip 1 , which is delimited in cross-section by two convex and one concave curved segments and has the form of a flat, irregular triangle.
In this case, the concave side is the flank produced by the preceding cut, and the long convex side is the flank produced by the the new cutting edge S. The short convex flank is the length ΔI U measured along the circumference of the branch piece, that is to say the circumferential length between two successively arranged cutting edges of the tool striking the circumference of the workpiece.
In practice, of course, the chip 1 does not retain the shape which can be seen in FIG. 7, but rather is rolled up spirally owing to the deflection at the tool face of the cutting edge.
It can be seen from FIG. 7 that the chip thickness, e.g. h 1 , of the chip 2 —viewed in the passage direction of the cutting edge—increases rapidly up to the maximum chip thickness h max . From there, the chip thickness decreases relatively slowly and continuously to the end (e.g. h x ).
If the difference between the base dimension and the final dimension remains the same and the rotational speed of the workpiece likewise remains the same, it can be seen from this illustration that a reduction in the rotational speed of the tool has the effect of increasing the cut distance ΔI U , and thus also of increasing h max .
Again viewed in the Z-direction, FIG. 8 illustrates, for example, a crankshaft for a 6-cylinder in-line engine having three crankpin journals H 1 -H 3 with different rotational positions with respect to the centre bearing ML.
Two separate tools, for example disc-like external-milling cutters (WZ 1 , WZ 2 ), are being used on this crankshaft at different axial positions. One of the tools could, for example, machine the crankpin journal H 1 , and the other the crankpin journal H 2 , as illustrated in FIG. 8, but it would also be possible for one of the tools to machine a crankpin journal and the other of the tools to machine the end face of a web.
In the latter case, the machining of the web could in theory take place partially with the crankshaft stationary, in that the relevant tool WZ 1 or WZ 2 works along the end face of the web in the feed direction, that is to say in the X-direction. However, since if the crankshaft is stationary it is not possible to achieve any progress with the machining, taking place at a different axial position, of a peripheral surface, whether of a crankpin journal H or of a centre bearing ML, the machining of the web surface is preferably also carried out with the crankshaft rotating.
If the machining of the web starts in that position of the crankshaft which is illustrated in FIG. 8 and then the crankshaft rotates further, the result is the cutting paths s a , s b , s m , s x , some of which are drawn in FIG. 8 .
As can be seen, these cutting paths, owing to the climb-cutting operation of the milling cutter, together with the rotation of the workpiece, are at a greater distance apart at the point where they begin than at the point where they end, that is to say the point at which the cutting edge leaves the side face of the web.
FIG. 9 shows the relationships when two separate tools WZ 1 , WZ 2 are simultaneously machining two different crankpin journals H 1 , H 2 . Independently of one another the tools WZ 1 and WZ 2 can move in a defined manner in the X-direction and their rotational speed can be controlled. However, the parameter which links them is the rotation of the crankshaft, as the workpiece, which is driven in rotation, likewise in a controlled manner, about the centre bearings, which rotation can also be stopped for certain machining operations.
In the situation illustrated in FIG. 9, crankpin journal H 2 is situated in line with the centre bearing ML 1 and the centre point M 1 and M 2 of the tools WZ 1 or WZ 2 . The crankpin journal H 1 is offset through about 120° in the clockwise direction with respect to the centre bearing.
If, as indicated, the tools WZ 1 and WZ 2 are each rotating anticlockwise and the crankshaft—as drawn in at its centre bearing ML—is rotating in the clockwise direction, the big-end journal H 1 is clearly being milled by a climb-cutting method, which effect is desirable for the reasons given above.
For the big-end journal H 2 , one could gain the impression that it is subject to ordinary milling, since at this point the tool WZ 2 is moving downwards but the crankpin journal H 2 is moving upwards.
However, the absolute movement of the crankpin journal is not the deciding criterion in assessing whether ordinary or climb-milling is taking place, but rather the important factor is whether the big-end journal H 2 is rotating about its own centre point allowing its surface at the machining point still to move in the same direction as the milling cutter.
However, viewed in absolute terms, the crankpin journal H 2 , which is migrating upwards in FIG. 9, is clearly rolling upwards along the tool WZ 2 , so that, therefore, the big-end journal is rotating in the clockwise direction relative to the centre point of the big-end journal H 2 and therefore de facto climb-cutting is the prevailing circumstance at the machining point.
FIG. 9 furthermore shows the relationship which is necessarily present between the machining on the two big-end journals H 1 and H 2 , which relationship is to be taken into account primarily in optimizing a plurality of machining operations which take place simultaneously with regard, for example, to a specific chip thickness.
It has been assumed that the milling cutter WZ 2 in relation to the crankshaft 1 —of which only the centre bearing ML and the two crankpin journals H 1 and H 2 currently being machined are shown in FIG. 9, for the sake of clarity—are rotating so quickly with respect to one another that the crankshaft has been rotated further through the angle Δα between the engagement of two successive cutting edges of the tool WZ 2 on the big-end journal H 2 . Since in FIG. 9 the centre point of the big-end journal H 2 and the centre point of the crankshaft, that is to say of the centre bearing ML, are in line with the centre M 2 of the tool WZ 2 , the pivot angle Δα provides an offset a 2 of the point where the new cutting edge strikes with respect to the old cutting edge, which runs almost precisely in the Y-direction.
As a result, it is only necessary for there to be a very small X-component x 2 by means of a corresponding X-movement of the tool WZ 2 , and the resultant cutting distance ΔI U2 determines a chip cross-section, the thickness of which is intended to correspond to the optimum chip thickness.
It is also intended, as far as possible, for the same chip thickness to be achieved at the machining point of the crankpin journal H 1 . Assuming that the rotational speed and diameter of the tools WZ 1 and WZ 2 are the same, the centre point of the crankpin journal H 1 has also been pivoted through the angle Δα with respect to the centre of the big-end journal by the time that the next cutting edge of the tool WZ 1 comes into action.
The offset a 1 , thus brought about at the machining point is in this case greater to only a negligible extent than a 2 , since the distance from the centre of the centre bearing ML to the machining point on the big-end journal H 1 is slightly greater than the distance to the centre of the big-end journal H 1 . This offset a 1 has a pronounced component x 1 in the X-direction, which component has to be compensated for by a corresponding movement of the tool WZ 1 in the X-direction. Thus only a relatively small component of a 1 remains as the cutting distance ΔI U1 in the Y-direction. This would result in the thin chip, which is illustrated to the outside on the right-hand side in FIG. 9, with a maximum thickness of only H 1max , which is much smaller than the optimum chip thickness.
In order to reach the optimum chip thickness at this machining point too, the rotational speed of the tool WZ 1 has to be reduced by comparison with the rotational speed of WZ 2 , so that the cutting distance ΔI U1 increases to such an extent that the desired chip thickness is also achieved on the crankpin journal H 1 . It is necessary here to reduce the rotational speed of tool WZ 1 to a maximum of about 30% of the rotational speed of tool WZ 2 .
In addition to the first optimization target described of a specific—average or maximum—chip thickness, the secondary optimization target could be a cutting speed which is intended to move within a predetermined target corridor or is intended not to exceed a specific maximum value.
In the former case, this would lead, in the case of the machining illustrated in FIG. 9, to the rotational speeds of the workpiece and of the tool WZ 2 , during the machining of the big-end journal H 2 , being increased with respect to one another—such that the desired chip thickness is maintained on the big-end journal H 2 , to such an extent that the rotational speed of tool WZ 2 moves at the upper end of the specified range for the cutting speed. This also results in an increase in the rotational speed of the tool WZ 1 , as a result of which the cutting speed on the crankpin journal H 1 should likewise still lie within the specified range for the cutting speed.
By contrast, if an upper limit is specified for the cutting speed, this upper limit would be applied to the machining on the crankpin journal H 2 , which has the higher cutting speed by comparison with the machining on the crankpin journal H 1 , so that, as a result, an absolute upper limit of the cutting speed is automatically observed at both machining points present.
In the event of more than two points on a crankshaft being machined simultaneously, in an analogous manner the limiting criterion for absolute maximum or minimum values is always to be applied to the machining point which has the relatively highest or lowest corresponding value.
When specified ranges of certain cutting parameters are being applied, it may be that it is not possible to observe this range for all the machining points. In this event, either the specified range width should be increased or a third-priority optimization parameter has to be specified. This third optimization variable could, for example, be the chip length (primarily in the case of the machining of web side faces).
The mutual dependencies illustrated in FIG. 9 when observing a specific chip thickness occur to an increased extent when one of a plurality of simultaneous machining points on the crankshaft is the machining of an end face of a web, as illustrated in FIG. 10 . The illustration in FIG. 10 shows a crankshaft, for example for a four-cylinder in-line engine, in which the crankpin journals H 1 and H 2 are situated opposite one another, in the radial direction, with respect to the centre bearing ML.
If, in the position illustrated in FIG. 10, one were to begin machining the web surface 3 by means of the tool WZ, the crankshaft would rotate further in the direction indicated (in the clockwise direction) about the centre of the centre bearing ML, while the tool WZ is rotating anticlockwise, in order to bring about climb-cutting milling.
Some of the resultant cutting paths s a , s b , s m , s x are drawn in on the web surface 3 .
The simultaneous rotation of the crankshaft results in chip cross-sections which are again considerably larger at the start of the chip than towards the end of the chip, and in addition the chips differ considerably in their length, depending on the respective position of the cutting path on the web surface 3 .
As a rule, it is not possible to dispense completely with a rotation of the crankshaft, since otherwise a machining operation, currently taking place at a different point of the crankshaft, on a bearing journal would no longer produce any progress in the machining.
Therefore, if, on a crankshaft, a plurality of web side faces or one web side face takes place at the same time as the machining of a bearing journal, the discrepancies in chip thicknesses between the various machining points, given identical rotational speeds and diameters of all the tools, which discrepancies were illustrated with reference to the example of FIG. 9, occur to an increased extent, so that it is necessary to an increased extent for the rotational speeds, and/or in the case of the machining of a web also the movement in the transverse direction, that is to say the X-direction, by the milling cutter, to be adjusted continually, in order to observe the desired optimum chip thickness in each phase of the machining and at all the machining points at the same time.
As shown by FIG. 11, in order to protect the workpiece, the procedure is as follows even at the start of the machining of the peripheral surface, for example of a bearing journal:
Despite the rotation of the workpiece, the milling cutter is fed in relatively slowly as far as the desired radial dimension. A radial in-feed which is too quick would not only increase the chip thickness to unacceptable levels but also, above all, the corollary transverse forces which are introduced into the workpiece would become relatively high, due to the chip length, which is then considerable owing to the relatively great wrap between a disc-like external-milling cutter, which rotates about an axis parallel to the bearing-journal axis, and the current machining point.
As shown by FIG. 11, the milling cutter is moved forwards radially towards the centre point of the bearing journal to be machined so slowly that the existing extent is acted on by the milling cutter only after a traverse-in angle of about 50-70, preferably about 60°, of the bearing-journal circumference. Starting from this point, it is necessary to execute a complete revolution of the bearing journal to be machined, and preferably slightly more, that is to say about 370°, in order to achieve optimum adaptation of the actual contour to the desired contour of the journal. The milling cutter can then traverse directly radially outwards.
In addition, in FIG. 11 correction points with an intervening angle of about 10-15° with respect to the centre point of the crankpin journal to be machined are arranged along the machining path.
After producing the first components of a series to be machined, the extent to which the actual circumferential contour approaches the desired circumferential contour can be measured and the actual contour achieved can subsequently be corrected empirically by modifying each of the individual correction points, by entering corresponding correction values for the individual correction points into the machine control system.
Furthermore, in FIG. 10 the circumferential contour of the web is flattened off at one point in a planar manner. The circumferential contour of the web surface is also partially machined by means of external milling. The external milling according to the invention makes it possible—by means of a corresponding control of the rotational position, that is to say of the rotational speed of the crankshaft in relation to the X-displacement of the milling cutter—not only to achieve any desired (that is to say outwardly curved) contour, but also to achieve planar flattened portions which lie, for example, tangentially with respect to the centre bearing ML of the crankshaft. Planar milled areas of this kind are required either for the subsequent attachment of, for example, counterweights, or else for balancing the crankshaft directly in the chucking of the metal-removing machining operation.
It is even possible to produce concave, that is to say recessed, circumferential contours, as long as the radius of curvature thereof is greater than the radius of the disc-like external-milling cutter.
FIG. 12 shows a section through a metal-removing tool WZ, for example a turning tool, most designations and angles applying both to turning and to milling. Here, the cutting edge, for example the main cutting edge S, is formed by the edge formed by the tool face A γ and the main flank A α , and the secondary cutting edge S′ is formed by the tool face A γ and the secondary flank A′ α running at an angle to the main flank A α . The cutting edge S, which in FIG. 12 is shown as a sharp edge, is in practice never completely sharp, but rather has to have a certain degree of rounding, the cutting edge rounding (CER), in order to prevent the cutting edge chipping.
Various directions and planes with respect to the tool are defined in FIGS. 13 and 14.
In these Figures, the tool reference plane P r is a plane through the selected cutting-edge point, specifically perpendicular to the assumed cutting direction. The tool reference plane P r is in this case as far as possible selected such that it lies parallel or perpendicular to an axis of the tool. It has to be stipulated individually for each type of tool. In the case of turning tools, the tool reference plane P r is a plane parallel to the base of the shank for conventional turning tools, while in the case of milling tools it is a plane which contains the axis of the milling tool.
The assumed working plane P f is a plane through the selected cutting-edge point, perpendicular to the tool reference plane P r and parallel to the assumed feed direction.
The tool rear plane P p is a plane through the selected cutting-edge point, perpendicular to the tool reference plane P r and perpendicular to the assumed working plane P f . P r , P p and P f thus form a coordinate system through the assumed cutting-edge point.
The tool cutting-edge plane P s (see FIG. 14) is a plane through the cutting-edge point, tangential with respect to the cutting edge S and perpendicular to the tool reference plane P r . If the tool cutting edge S is at right angles to the feed direction, tool cutting edge plane P s and tool rear plane P p coincide.
The tool orthogonal plane P c is a plane through the cutting-edge point, perpendicular to the tool reference plane P r and perpendicular to the tool cutting-edge plane P s . Therefore, if the tool cutting edge S is at right angles to the feed direction, tool orthogonal plane P c and assumed working plane P f coincide.
The orientation of the individual tool cutting edges with respect to the workpiece can be seen more clearly from FIGS. 15 and 16, separately for plain turning and face turning. Considered in this plan view, the tool has at its cutting-edge point a tool nose angle ε r between the tool cutting-edge plane P s of the main cutting edge and the tool cutting-edge plane P′ s of the secondary cutting edge, measured in the tool reference plane P r .
In this case, the main cutting edge is at a tool adjustment angle κ r between the tool cutting-edge plane P s and the assumed working plane P f , measured in the tool reference plane P r .
FIGS. 18 a- 18 f directly show the position of the individual sections and views, some of which are from FIGS. 15 and 16.
The relevant angles here are:
Tool side rake γ f : angle between the tool face A γ and the tool reference surface P r , measured in the working plane P f ;
Tool rear rake γ p : angle between the tool face A γ and the tool reference plane P r , measured in the tool rear plane P p ;
Tool normal cutting rake γ n : angle between the tool face A γ and the tool reference plane P r , measured in the tool cutting-edge normal plane P n ; the value of this angle γ n (positive or negative) is usually referred to in a generalized way as “positive/negative tool geometry”.
Tool cutting-edge angle of inclination λ s (FIG. 18 e ): angle between the cutting edge S and the tool reference point P r , measured in the tool cutting-edge plane P s .
This tool cutting-edge angle of inclination λ s is an acute angle, the point of which faces towards the tool nose. It is positive when the cutting edge, to be viewed starting from the tool nose, lies on that side of the tool reference plane P r which faces away from the assumed cutting direction.
α generally denotes the clearance angle of a cutting edge.
FIG. 19 shows a web-cutting tip, which is screwed on the end side, preferably on both sides, onto the disc-like base body of the milling cutter and thus protrudes beyond the base body both radially and on the end side. In order to abrade the material from the end face of the web, with the milling cutter rotating the latter is moved forwards in the X-direction, that is to say radially with respect to the workpiece, as the feed direction. Here, the plane of the bit-like web-cutting tip, i.e. the tool cutting-edge plane P s , is positioned at a small angle κ to the working plane P f , which is composed of the feed direction (X-direction) and the cutting direction, which lies in the X-Y plane. As a result, the outer edge, which is rounded with the nose radius R of about 1.6 mm, of the cutting bit projects obliquely outwards from the base body and forms the point which protrudes furthest axially with respect to the base body of the milling cutter.
The larger the angle κ, the more wavy the machined end face of the web becomes, as can be seen from the already machined part in FIG. 19 .
In order to be able to machine the entire end face of a web, an additional rotation of the crankshaft may additionally be necessary as well as the feed, depicted in FIG. 19 a , in the X-direction of the milling cutter, if, for example, it is intended to machine the web surface as far as the crankpin journal H 2 and around the latter.
In the case of a web-cutting tip as shown in FIG. 19 a , the extent of the tip in the radial direction of the body of the milling cutter is referred to as the length of the cutting tip, the extent in the tangential direction of the disc-like base body of the tool is referred to as the width, and the extent in the direction of the cutting bit closest to the axial direction is referred to as the thickness.
FIG. 19 b shows, in the same direction of viewing as FIG. 19 a , the machining of the peripheral surface of a journal of the crankshaft by means of a journal-cutting tip. For a tip of this kind, length and width are intended to mean the sides which can be seen in the plan view of FIG. 19 b , square throw-away cutting-tool tips usually being used as journal-cutting tips; these throw-away cutting-tool tips can thus be used four times in succession.
The journal-cutting tips can then be fastened with their external cutting edge at a small angle deviating from the Z-direction within the Z-X plane on the base body of the side-milling cutter if, at the same time, a deviation from the Z-direction is also provided within the Z-Y plane.
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The problem addressed by the invention is to provide a milling machine which can be used to machine eccentric end faces and peripheral faces and which ensures a short machining time despite its simple design. A milling machine of this king for machining workpieces and with means of clamping eccentric end faces or enveloping surfaces, e.g. of a crankshaft ( 1 ), with a bed ( 20 ), with two mutually facing chucks ( 21, 22 ) to accommodate the workpiece ( 1 ), at least one of these chucks being rotatable and positionable (C 1 axis) by means of a headstock ( 23, 24 ), with a tool holder ( 25, 26 ) which can be moved at right angles to the Z axis and has a rotatable milling cutter ( 5, 6 ), and with a control mechanism is characterized by a plurality of tool holders which can be controlled independently of each other in terms of both milling cutter rotation and travel in a transverse direction, and in that the control mechanism controls not only the rotation of the workpiece but also the transverse movement of the tool holders and the rotation of the milling cutters.
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BACKGROUND OF THE INVENTION
The field of the invention is the synthesis of ammonia in a continuous process whereby a gas mixture containing an approximately stoichometric ratio of hydrogen and nitrogen is passed over a series of catalyst beds at relatively high pressure and controlled temperatures. Specifically, the invention herein relates to temperature regulation in this process by means of heat exchange effected between portions of the gas mixture itself at various stages of its progress through the process.
Ammonia production as commercially practiced utilizes the seemingly straightforward reaction between nitrogen and hydrogen in stoichometric amounts: N 2 +3H 2 →2NH 3 . The reaction is exothermic; accordingly, the equilibrium is shifted to the right by lower temperatures. However, as a practical matter, the temperature must be maintained at an elevated level in order to increase the reaction rate sufficiently to carry out the process in a reasonably short amount of time, even though catalysts are also used to accelerate the rate of the reaction. Thus, an appropriate balance between thermodynamic and kinetic considerations determine the appropriate temperature range at which the synthesis should be operated.
Thermodynamic considerations would also millitate that the reaction would be favored by higher pressure, since collisions between gas molecules are required to effect the synthesis. The pressure range at which this process is generally carried out is over 100 atmospheres, although it has been disclosed that synthesis procedures are possible with pressures of as low as 20 atmospheres (U.S. Pat. No. 3,957,449).
Temperature regulation is most often accomplished by a "quench" type ammonia conversion process. In this process, the synthesis gas containing nitrogen and hydrogen in roughly stoichometric amounts (syngas), preferably with as few diluents as possible, is passed through a catalytic bed of, for example, iron or promoted iron, to produce an effluent which is at a higher temperature than the original mixture due to the exothermic nature of the reaction. The effluent contains some percentage of ammonia, representing for example, 10 to 15% total volume. The temperature of the emerging gas is ordinarily sufficiently high to be thermodynamically inhibitory to further reaction. Therefore, before the effluent is passed through still another catalyst bed in order to increase the percentage conversion to ammonia, it is mixed with "cold" fresh synthetic gas thus lowering the temperature of the new mixture to the proper level. This process may be repeated for as many passes through catalyst beds as is desired. However, it suffers from the drawback that obviously not all of the syngas will pass through all of the catalyst beds.
U.S. Pat. No. 4,230,680 to Becker describes an alternative process whereby rather than mixing fresh syngas with partially converted effluent, only heat exchange between the fresh syngas and effluent is effected, not physical mixing of the gases. In the Becker process, a portion of effluent from each and every catalytic bed in the series is passed through a heat exchanger in which portion of the feed syngas provides a heat sink. U.S. Pat. No. 3,851,046 to Wright and Pickford discloses a two-bed process in which heat exchange is effected between effluent from the first bed and fresh syngas and the effluent from a single second bed is cooled by high-pressure steam generation. Both of the foregoing approaches turn out to be less efficient than that of the present invention wherein only the effluent from the first pass of syngas over catalyst is heat exchanged; and further cooling of subsequent effluents from multiple beds is accomplished by high pressure steam generation, which high pressure steam may then be employed for other purposes.
SUMMARY OF THE INVENTION
The invention herein relates to a process for synthesis of ammonia which establishes control of the temperature of the synthesis reaction through a combination of heat exchange between portions of the gas mixture flowing through the system, and high pressure steam generation by cooling effluents from a series of catalyst beds.
More specifically, the present invention relates to a process for synthesis of ammonia which employs a heat exchange between only the effluent of the first pass of syngas over a catalyst bed and at least a portion of the fresh syngas. Additional temperature control with respect to effluent of each of multiple succeeding catalytic beds is accomplished by including in the system, in series with each bed, a high pressure steam generator, which utilizes the heat of the effluent gas to generate steam of 1000 to 2000 psig, preferably 1500 psig.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic showing an embodiment of the invention wherein three catalytic beds are employed.
FIG. 2 shows a schematic of an internal bypass system.
DETAILED DESCRIPTION OF THE INVENTION
Definitions and General Parameters
As used herein, "syngas" or "synthesis gas" refers to a mixture of nitrogen and hydrogen in a ratio of 1:3 approximately, which may contain diluents such as argon and methane. While it is desirable to have zero diluent concentration, this is seldom achieved, and the syngas though composed substantially of hydrogen and nitrogen in stoichometric ratio may be debilitated proportionally to the amount of contaminants therein. The process of the invention is affected by the presence of such diluents in essentially the same manner as alternate methods for carrying out the synthesis would be so affected.
"Final product effluent" represents the gas which has passed through the entire system and which is to be subjected to recovery processes to extract the ammonia therefrom.
Catalysts which are successful in accelerating the synthesis of ammonia are well known in the art. Prominent among these are finely divided iron, and promoted iron catalyst. While presumably the discovery of a superb catalyst which accelerates the reaction sufficiently that it would proceed at an acceptable rate at, for example, 400°-500° F. would alter the desired temperatures quoted hereinafter, the general principle on which the process of the invention rests would not be altered by the substitution of such improved catalysts, should they become known. However, of course, the preferred temperature ranges would be correspondingly lowered.
There are also a variety of designs for equipment which would contain the catalyst bed and through which the syngas flows in order to effect the conversion. The two major types of synthesis chambers which are now known are radial flow converters, and more commonly the OSW type ammonia converter in which the synthesis gas flow is downward or axial through the beds. The pattern of flow through the converter is not critical to the process of the invention.
Finally, no matter how many catalytic beds are employed, it is impracticable to obtain complete conversion of the synthesis gas to ammonia. Typically, the first catalytic pass results in a conversion of from 15 to 20% of the starting materials to ammonia, and succeeding passes result in further conversions. By application of the process of the present invention, after employing only three converters in series, the final product effluent should contain approximately 20% ammonia by volume which represents approximately 30-35% conversion of the starting material.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The preferred embodiment is best understood with reference to FIG. 1.
Syngas, as purified as is possible, enters the system at 102 and is passed through a heat exchanger 104 in which the heat source is at least a portion of the final product effluent.
The syngas which has thus been heated, preferably to a temperature of approximately 500° to 600° F. is then divided using the bypass control line with valve at 106, so that a portion of it passes directly finally to the first of the catalytic beds (A) at 108, and another portion passes through the heat exchanger 110 where it is used to cool the effluent from the first catalytic converter, and resulting in its temperature being further raised. The effluent from the heat exchanger 110 is then combined at 112 with the syngas from the bypass and the mixture is fed into the first converter in the series at 108. The temperature of the combined gases as they enter the first converter, labeled A in FIG. 1, is preferably between 700° to 800° F. In passing through converter A, a portion of the nitrogen and hydrogen are converted to ammonia in an exothermic reaction such that the exit temperature at 114 is between 900° and 1000° F. The effluent is cooled by providing the heat to the feed syngas in the aforesaid heat exchanger 110. Control over the final temperature before entry into catalyst bed B is maintained by the bypass line controlled by valve 106 which controls the amount of cooling gas. The gas entering the second catalytic bed B at 122 is preferably between 700° to 800° F. Further conversion to ammonia takes place in converter B with generation of sufficient heat to provide an effluent with an exit temperature at 124 of 850° to 950° F. This effluent gas is cooled by operation of a high pressure steam generator 126 to a temperature of 700° to 800° F., the proper temperature for the pass over the catalyst bed in converter C. Control over this process is maintained by a control valve in the bypass line at 127; the fraction of gas bypassing the steam generator being sufficient to retain the proper high temperature. Similarly, the reaction taking place in converter C results in an increase in temperature of the flowing gas mixture so that the temperature of the gas at the high pressure steam generator 128 is 800° to 900° F. As a result of the operation of the high pressure steam generator 128, the gas is cooled to 600° to 750° F. Again, a bypass and control valve, 129, are provided. At least a portion of the gas emerging from the high pressure steam generator 128 is passed through the heat exchanger 104 to heat the original feed syngas to a temperature of about 500° to 600° F. The final product effluent is then subjected, by conventional means, to an ammonia recovery process.
By means of the operation of this process, a conversion of about 35% of the syngas to ammonia is achievable with three catalysis beds. By balancing the temperatures and control through heat exchange between the flowing gas at various stages of reaction, but using steam generation after multiple catalytic beds, subsequent to the first a comparatively high conversion is achieved.
The preferred embodiment described is provided with control mechanisms to regulate the temperature by controlling gas flow previous to the first heat exchanger (106) and in parallel with the high pressure steam generators (127 and 129). However, the invention is not limited to these locations for regulatory opportunities. For example, a bypass with control valve could be provided subsequent to the high pressure steam generator 128 so as to control the amount of warming gas entering the heat exchanger 104. Also, for example, a bypass could be provided after the effluent from tank A so that only a portion of the heated gas would enter the heat exchanger 110.
In all of these cases, and as shown in FIG. 1, the bypass may be by means of a separate bypass line with control valve. However, it is generally preferable to incorporate, instead, an internal bypass valve, as shown schematically in FIG. 2, instead of a separate line. In operation, the incoming gas through inlet 201 exits through outlet 202 when the control valve 205 is closed so as to prevent flow of gas through passage 206. Varying proportions of the gas are allowed to exit at outlet 204 depending on the adjustment of the opening of this control valve. Bypass valves of this general instruction are well known in the art, and provide additional economy by eliminating the need for an extra line.
The following example is intended to illustrate the invention. It is not to be construed as limiting the scope.
EXAMPLE 1
Referencing FIG. 1, through line 102 is introduced at 188 bar pressure and 127° F. a feed gas stream containing 18,069 kg moles of hydrogen and 5,940 kg moles of nitrogen per hour. (The mixture contains, in addition, 840 kg moles of ammonia, 832 kg moles of argon and 211 kg moles of helium per hour; the helium and argon flows will remain substantially constant). After passing through the heat exchanger 104, the temperature of the mixture is 541° F.; after passing through heat exchanger 110, and being recombined with the portion circulating through the bypass valve 106, the temperature of the gas is 752° F. The mixture is then passed over catalyst bed A for partial conversion to ammonia. The catalyst is a 15 m 3 cylindrical bed of 2.48 m 1D and 3.1 m in length (iron oxide). The exit gas from A is at 964° F. and contains 2,549 kg moles of ammonia, per hour 15,505 kg moles of hydrogen and 5,085 moles of nitrogen, representing a total of approximately 20% conversion. The exit gas is then passed through heat exchanger 110 to attain a temperature of 752° F., whereupon it enters catalyst bed B. The catalyst bed in B is 46 m 3 and is also cylindrical of 3.0 m 1D and 6.6 m in length. After further conversion to ammonia, the exit gas from the catalyst B is at 901° F., and contains 3,740 moles ammonia, 13,720 moles hydrogen and 4,490 moles nitrogen, representing a total conversion of 29%. The effluent from the high pressure steam generator when combined with the gas which has circulated through the bypass valve system at 129 is at 752° F. as it enters the third catalyst bed in the series, C. The catalyst bed at C is 77 m 3 and has a 3.2 m Id and is 9.6 m long. After the pass over catalyst bed C, the effluent contains 4510 kg moles ammonia per hour, 12,564 kg moles hydrogen and 4105 kg moles nitrogen, representing 35% total conversion. The temperature of existing mixture, which is 849° F. is then lowered to 619° F. by generation of steam before further cooling in the heat exchanger 104. The final product effluent exiting at 132 then represents approximately 31% conversion to ammonia (based on nitrogen fed to the system), and has an exit temperature of 181° F.
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A process for synthesizing ammonia with improved efficiency is disclosed. The increase in efficiency is achieved by regulation of the temperature of at least three catalyst beds connected in series by a combination of influent/affluent heat exchange and high pressure steam generation.
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This is a divisional application of application Ser. No. 08/066,188, filed on May 21, 1993 now U.S. Pat. No. 5,411,636.
BACKGROUND OF THE INVENTION
In the manufacture of tissue products, it is generally desireable to provide the final product with as much bulk as possible without compromising other product attributes. However, most tissue machines operating today utilize a process known as "wet-pressing", in which a large amount of water is removed from the newly-formed web by mechanically pressing water out of the web in a pressure nip between a pressure roll and the Yankee dryer surface as the web is transferred from a papermaking felt to the Yankee dryer. This wet-pressing step, while an effective dewatering means, compresses the web and causes a marked reduction in the web thickness and hence bulk.
On the other hand, throughdrying processes have been more recently developed in which web compression is avoided as much as possible in order to preserve and enhance the bulk of the web. These processes provide for supporting the web on a coarse mesh fabric while heated air is passed through the web to remove moisture and dry the web. If a Yankee dryer is used at all in the process, it is for creping the web rather than drying, since the web is already dry when it is transferred to the Yankee surface. Transfer to the Yankee, although requiring compression of the web, does not significantly adversely affect web bulk because the papermaking bonds of the web have already been formed and the web is much more resilient in the dry state.
Although throughdried tissue products exhibit good bulk and softness properties, throughdrying tissue machines are expensive to build and operate. Accordingly there is a need for producing higher quality tissue products by modifying existing, conventional wet-pressing tissue machines.
SUMMARY OF THE INVENTION
It has now been discovered that the bulk of a wet web can be significantly increased with little capital investment by abruptly deflecting the wet web, at relatively high consistency, into the open areas or depressions in the contour of a coarse mesh supporting fabric, preferably by pneumatic means such as one or more pulses of high pressure and/or high vacuum. Such abrupt flexing of the web causes the web to "pop" or expand, thereby increasing the caliper and internal bulk of the wet web while causing partial debonding of the weaker bonds already formed during partial drying or dewatering. This operation is sometimes referred to herein as wet-straining. The web can then be dried to preserve the increased bulk. This discovery is particularly beneficial when applied to wet-pressing processes in which a relatively large number of bonds are formed in the wet state, but it can also be applied to throughdrying processes to further improve the quality of the resulting tissue product.
The effects of wet-straining on the web can be quantified by measuring the "Debonded Void Thickness" (hereinafter described), which is the void area or space not occupied by fibers in a cross-section of the web per unit length. It is a measure of internal web bulk (as distinguished from external bulk created by simply molding the web to the contour of the fabric) and the degree of debonding which occurs within the web when subjected to wet-straining. The "Normalized Debonded Void Thickness" is the Debonded Void Thickness divided by the weight of a circular, four inch diameter sample of the web. The determination of these parameters will be hereinafter described in connection with FIGS. 8-13.
Hence, in one aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) dewatering or drying the web to a consistency of 30 percent or greater; (c) transferring the web to a coarse mesh fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (e) drying the web.
In another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) throughdrying the web to a consistency of from about 40 to about 90 percent while supported on the coarse fabric; (g) transferring the throughdried web to a Yankee dryer to final dry the web; and (h) creping the web.
In yet another aspect, the invention resides in a method for making a wet-pressed tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the wet web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) transferring the web to a transfer fabric; (g) transferring the web to the surface of a Yankee dryer and drying the web to final dryness; and (h) creping the web.
In still another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web against the surface of a Yankee dryer and transferring the web thereto; (d) partially drying the web to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) transferring the web to a second Yankee dryer and final drying the web; and (h) creping the web.
In a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdryer fabric and partially drying the web in a first throughdryer to a consistency of from about 28 to about 45 percent; (c) sandwiching the partially-dried web between the throughdryer fabric and a coarse fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; (e) carrying the web on the throughdryer fabric over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (f) transferring the throughdried web to a Yankee dryer; and (g) creping the web.
In yet a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdrying fabric; (c) carrying the web over a first throughdryer and partially drying the web to a consistency of from about 28 to about 45 percent; (d) transferring the partially dried web to a second throughdrying fabric; (e) sandwiching the partially dried web between the second throughdrying fabric and a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) carrying the web over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (h) transferring the web to a Yankee dryer; and (i) creping the web.
In another aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the web to a papermaking felt; (c) compressing the web in a pressure nip to partially dewater the web and transferring the web to a Yankee dryer; (d) partially drying the web on the Yankee dryer to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse mesh fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (g) throughdrying the web.
In all aspects of the invention, the web can be creped, wet or dry, one or more times if desired. Wet creping can be an advantageous means for removing the wet web from the Yankee dryer.
The nature of the coarse fabric is such that the wet web must be supported in some areas and unsupported in others in order to enable the web to flex in response to the differential air pressure or other deflection force applied to the web. Such fabrics suitable for purposes of this invention include, without limitation, those papermaking fabrics which exhibit significant open area or three dimensional surface contour or depressions sufficient to impart substantial z-directional deflection of the web. Such fabrics include single-layer, multi-layer, or composite permeable structures. Preferred fabrics have at least some of the following characteristics: (1) On the side of the molding fabric that is in contact with the wet web (the top side), the number of machine direction (MD) strands per inch (mesh) is from 10 to 200 and the number of cross-machine direction (CD) strands per inch (count) is also from 10 to 200. The strand diameter is typically smaller than 0.050 inch; (2) On the top side, the distance between the highest point of the MD knuckle and the highest point of the CD knuckle is from about 0.001 to about 0.02 or 0.03 inch. In between these two levels, there can be knuckles formed either by MD or CD strands that give the topography a 3-dimensional hill/valley appearance which is imparted to the sheet during the wet molding step; (3) On the top side, the length of the MD knuckles is equal to or longer than the length of the CD knuckles; (4) If the fabric is made in a multi-layer construction, it is preferred that the bottom layer is of a finer mesh than the top layer so as to control the depth of web penetration and to maximize fiber retention; and (5) The fabric may be made to show certain geometric patterns that are pleasing to the eye, which typically repeat between every 2 to 50 warp yarns. Suitable commercially available coarse fabrics include a number of fabrics made by Asten Forming Fabrics, Inc., including without limitation Asten 934, 920, 52B, and Velostar V800.
The consistency of the wet web when the differential pressure is applied must be high enough that the web has some integrity and that a significant number of bonds have been formed within the web, yet not so high as to make the web unresponsive to the differential air pressure. At consistencies approaching complete dryness, for example, it is difficult to draw sufficient vacuum on the web because of its porosity and lack of moisture. Preferably, the consistency of the web will be from about 30 to about 80 percent, more preferably from about 40 to about 70 percent, and still more preferably from about 45 to about 60 percent. A consistency of about 50 percent is most preferred for most furnishes and fabrics.
The means for deflecting the wet web to create the increase in internal bulk can be pneumatic means, such as positive and/or negative air pressure, or mechanical means, such as a male engraved roll having protrusions which match up with the depressions or openings in the coarse fabric. Deflection of the web is preferably achieved by differential air pressure, which can be applied by drawing a vacuum from beneath the supporting coarse fabric to pull the web into the coarse fabric, or by applying positive pressure downwardly onto the web to push the web into the coarse fabric, or by a combination of vacuum and positive pressure. A vacuum suction box is a preferred vacuum source because of its common use in papermaking processes. However, air knives or air presses can also be used to supply positive pressure if vacuum cannot provide enough of a pressure differential to create the desired effect. When using a vacuum suction box, the width of the vacuum slot can be from approximately 1/16" to whatever size is desired, as long as sufficient pump capacity exists to establish sufficient vacuum. In common practice vacuum slot widths from 1/8" to 1/2" are most practical.
The magnitude of the pressure differential and the duration of the exposure of the web to the pressure differential can be optimized depending upon the composition of the furnish, the basis weight of the web, the moisture content of the web, the design of the supporting coarse fabric, and the speed of the machine. Without being held to any theory, it is believed that the sudden deflection of the web, followed by the immediate release of the pressure or vacuum, causes the web to flex down and up and thereby partially debond and hence expand. Suitable vacuum levels can be from about 10 inches of mercury to about 28 inches of mercury, preferably about 15 to about 25 inches of mercury, and most preferably about 20 inches of mercury. Such levels are higher than would ordinarily be used for mere transfer of a web from one fabric to another.
The number of times the wet web can be transferred to a coarse fabric and subjected to a pressure differential can be one, two, three, four or more times. To effect a more uniform bulking of the web, it is preferred that the wet straining vacuum be applied to both sides of the web. This can be conveniently accomplished simply by transferring the web from one fabric to another, in which the web is inherently supported on a different side after each transfer.
The method of this invention can preferably be applied to any tissue web, which includes webs for making facial tissue, bath tissue, paper towels, dinner napkins, and the like. Suitable basis weights for such tissue webs can be from about 5 to about 40 pounds per 2880 square feet. The webs can be layered or unlayered (blended). The fibers making up the web can be any fibers suitable for papermaking. For most papermaking fabrics, however, hardwood fibers are especially suitable for this process, as their relatively short length maximizes debonding rather than molding during the wet-straining operation. The wet-straining process can be used for either layered or homogeneous webs.
In carrying out the method of this invention, the change in Debonded Void Thickness of the web when subjected to the wet-straining step can be about 5 percent or greater, more preferably about 10 percent or greater, and suitably from about 15 to about 75 percent.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1A and 1B are cross-sectional photographs of a conventional wet-pressed tissue web and a tissue web processed in accordance with this invention, respectively, illustrating the increase in internal bulk resulting from the method of this invention.
FIGS. 2-7 are schematic flow diagrams of different aspects of the method of this invention referred to above.
FIGS. 8-13 pertain to the method of determining the Debonded Void Thickness of a sample.
FIG. 14 is a schematic illustration of the apparatus used to wet strain handsheets in the Examples.
FIG. 15 is a plot of the Debonded Void Thickness as a function of consistency, illustrating the data as described in Example 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Drawing, the invention will be described in greater detail. Wherever possible, the same reference numerals are used in the various Figures to identify the same apparatus for consistency and simplicity. In all of the embodiments illustrated, conventional papermaking apparatus and operations can be used with respect to the headbox, forming fabrics, dewatering, transferring the web from one fabric to another, drying and creping, all of which will be readily understood by those skilled in the papermaking art. Nevertheless, these conventional aspects of the invention are illustrated for purposes of providing the context in which the various wet-straining embodiments of this invention can be used.
FIGS. 1A and 1B are 150X photomicrographs of handsheets of nominally equal basis weight. The handsheet of FIG. 1A (Sample 1A) was wet-pressed, while the handsheet of FIG. 1B (Sample 1B) was wet-pressed and thereafter wet-strained in accordance with this invention. Both handsheets were made from 50/50 blends of spruce and eucalyptus dispersed in a British Pulp Disintegrator for 5 minutes. Both sheets were then pressed between blotters in an Allis-Chalmers Valley Laboratory Equipment press for 10-15 seconds at 90-95 pounds per square inch gauge (psig) pressure. Sheet consistencies were 56±3 percent. Sample 1A was then dried while sample 1B was wet-strained as described herein and then dried. As the photos illustrate, the wet-straining reduced the density of the sheet yielding a significantly higher caliper. Sample 1A is typical of the structure of wet-pressed sheets while Sample 1B has a more debonded structure having greater internal bulk, similar to a throughdried sheet. The Debonded Void Thickness of Sheet 1A was 31.5 microns compared to 38.9 microns for Sheet 1B. Normalizing using basis weight led to Normalized Debonded Void Thickness values of 138.2 microns per gram and 169.9 microns per gram, respectively. The 23 percent increase in Normalized Debonded Void Thickness with only a 14 percent reduction in tensile strength (from 1195 grams per inch of sample width to 1029 grams) illustrates the improvement provided by wet-straining.
FIG. 2 illustrates a combination throughdried/wet-pressed method of making creped tissue in accordance with this invention. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto an endless forming fabric 2 through which some of the water is drained from the fibers. The resulting wet web 3 retained on the surface of the forming fabric has a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4'. The press nip further dewaters the wet web to a consistency of about 30 percent or greater. The dewatered web 6 is then transferred to a coarse mesh throughdrying fabric 7 and wet-strained with vacuum source 8 positioned underneath the throughdrying fabric to abruptly deflect some of the fibers in the web into the open areas or depressions in the throughdrying fabric and thereby partially debond the web and increase its caliper or thickness. Also shown is an optional wet-straining station comprising a coarse mesh fabric 9 and a vacuum source 8', which can be used in addition to the other wet straining operation or as a replacement therefor. Providing two wet-straining stations provides added flexibility in the use of two different coarse mesh fabrics, which can be utilized to wet-strain the web independent of the desired throughdrying fabric. The wet-straining stations can operate on the web simultaneously or in sequence. In addition, in all of the embodiments shown herein, the wet-straining vacuum sources can be assisted by providing a high pressure air source which directs an air stream onto the opposite side of the web, thereby providing a further increase in pressure differential across the coarse fabric and increasing the driving force to deflect fibers into the coarse fabric.
The wet-strained web 10 is then carried over the throughdrying cylinder 11 and preferably dried to a consistency of from about 85 percent to about 95 percent. The dried web 12 is then transferred to an optional transfer fabric 13, which can be either fine or coarse, which is used to press the web against the surface of the Yankee dryer 14 with pressure roll 15 to adhere the web to the Yankee surface. The web is then completely dried, if further drying is necessary, and dislodged from the Yankee with a doctor blade to produce a creped tissue 16.
FIG. 3 illustrates a wet-press method of this invention in which a throughdryer is not used. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4'. The dewatered web 6 is then transferred to a coarse mesh fabric 31 and wet-strained using vacuum source 8' before transferring to fabric 32. Optionally, a vacuum source 8' can be utilized in addition to vacuum source 8 or in place of vacuum source 8. If used in addition to vacuum source 8, additional wet-straining can be achieved. If the coarseness of fabric 32 is different than that of fabric 31 or if the mesh openings of the two fabrics do not coincide, areas of the web not strained by the first vacuum source can be strained by the second vacuum source. In any event, the second vacuum source acts upon the opposite side of the web to achieve additional straining and debonding of the web. Wet-straining from both sides of the web can be particularly advantageous if layered webs are present, especially if the outer layers are more susceptible to debonding than the inner layer(s). As previously mentioned, a predominance of hardwood fibers in the outer layer lends itself well to wet-straining. The wet-strained web 33 is then transferred to the surface of Yankee dryer 14 using pressure roll 15 and dislodged by doctor blade (creped), resulting in creped tissue 34.
FIG. 4 illustrates a method of this invention utilizing two dryers in series with wet-straining in between. Shown is a headbox 1 which deposits the aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web 3 having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered and pressed onto the surface of Yankee dryer 14 using pressure roll 15. The consistency of the web after transfer to the surface of the Yankee is preferably about 40 percent. (The Yankee can optionally be replaced by a throughdryer, which would require transfer of the web from the felt 4 to a throughdryer fabric or replacement of the felt with a throughdryer fabric, not shown.) The Yankee (or the throughdryer) serves to partially dry the dewatered web to a consistency of preferably from about 50 to about 70 percent. The partially-dried web is then transferred to a coarse mesh fabric 41 with the assistance of vacuum suction roll 42 and wet-strained using vacuum source 8. Optionally, the web can be sandwiched between fabric 41 and another coarse fabric 41' and further wet-strained using a second vacuum source 8'. The second vacuum source can be applied to the web simultaneously with vacuum source 8 to simultaneously act upon both sides of the web, or the second vacuum source can be applied upstream or downstream of the first vacuum source to sequentially act upon opposite sides of the web. In any event, the application of two or more vacuum straining sources is expected to provide more uniform debonding of the web. After wet-straining, the web is transferred to a Yankee dryer 14' for final drying and creped to yield a creped tissue web.
FIG. 5 illustrates another embodiment of this invention in which two throughdryers are used to dry the web. Shown is the headbox 1 which deposits the aqueous suspension of papermaking fibers onto the surface of forming fabric 2. The wet web 3 is transferred to an optional fine mesh transfer fabric 51 and thereafter transferred to a coarse mesh throughdryer fabric 7. The web is then partially dried in the first throughdryer 11 to a consistency of preferably about 45 percent. The partially dried web is then sandwiched between the throughdryer fabric 7 and coarse mesh fabric 52 and wet-strained using vacuum source 8. (For purposes herein, bringing a web into contact with a coarse mesh fabric, such as sandwiching the web against the coarse mesh fabric 52, is considered "transferring" the web to the coarse mesh fabric, even though the web continues to travel with a different fabric, such as the throughdryer fabric in this case.) Optionally, the web can be simultaneously or subsequently wet-strained from the opposite direction on the throughdryer fabric to further debond the web.
After wet-straining, the web is carried over a second throughdryer 11' and further dried to a consistency of preferably about 85 to about 95 percent, transferred to a fine mesh fabric 53, and pressed onto the surface of a Yankee dryer 14 for final drying, if necessary, and creping to produce creped web 27. In the case of final drying on the second throughdryer, transfer to the Yankee for creping is an option. It is within the scope of this invention that whenever a throughdryer is used to dry the web, the final product can be uncreped.
FIG. 6 illustrates a similar process to that of FIG. 5, but using two throughdrying fabrics. Shown is the headbox 1 depositing the aqueous suspension of papermaking fibers onto the surface of the forming fabric 2. The web 3 is transferred to optional fine mesh fabric 51 and thereafter transferred to throughdrying fabric 7. The web is carried over the first throughdryer 11 and partially dried to a consistency of preferably about 45 percent. The partially dried web is then transferred to a second throughdryer fabric 7' and sandwiched between the second throughdryer fabric and coarse fabric 61. Vacuum source 8 is used to wet-strain and partially debond the web as previously described. Optionally, the web can be wet-strained from the opposite direction using alternative vacuum source 8', either in addition to or in place of vacuum source 8. The web is then further dried in a second throughdryer 11', transferred to a Yankee 14 and creped. Optionally, the web can be wet-strained using optional vacuum sources 8" and 8'". If vacuum source 8" is used, a coarse fabric 62 is used to provide the depressions into which the fibers in the web are deflected.
FIG. 7 illustrates another embodiment of this invention, similar to that illustrated in FIG. 4, but using a throughdryer 11 to final dry the web.
FIGS. 8-14 pertain to the method for determining the Debonded Void Thickness, which is described in detail below. Briefly, FIG. 8 illustrates a plan view of a specimen sandwich 80 consisting of three tissue specimens 81 sandwiched between two transparent tapes 82. Also shown is a razor cut 83 which is parallel to the machine direction of the specimen, and two scissors cuts 84 and 85 which are perpendicular to the machine direction cut.
FIG. 9 illustrates a metal stub which has been prepared for sputter coating. Shown is the metal stub 90, a two-sided tape 91, a short carbon rod 92, five long carbon rods 93, and four specimens 94 standing on edge.
FIG. 10 shows a typical electron cross-sectional photograph of a sputter coated tissue sheet using Polaroid® 54 film.
FIG. 11A shows a cross-sectional photograph of the same tissue sheet as shown in FIG. 10, but using Polaroid 51 film. Note the greater black and white contrast between the spaces and the fibers.
FIG. 11B is the same photograph as that of FIG. 11A, except the extraneous fiber portions not connected or in the plane of the cross-section have been blacked out in preparation for image analysis as described herein.
FIG. 12 shows two Scanning Electron Micrograph (SEM) specimen photographs 100 and 101 (approximately 1/2 scale), illustrating how the photographs are trimmed to assemble a montage in preparation for image analysis. Shown are the photo images 102 and 103, the white border or framing 104 and 105, and the cutting lines 106 and 107.
FIG. 13 shows a montage of six photographs (approximately 1/2 scale) in which the white borders of the photographs are covered by four strips of black construction paper 108.
FIG. 14 is a schematic illustration of the apparatus used to wet strain sample handsheets as described in the Examples. Shown is a sample holder 110 which contains an Asten 934 throughdrying fabric. The sample holder is designed to accept a similarly sized handsheet mold in which the handsheet sample is formed and supported by a suitable forming fabric. Also shown is a vacuum tank 111, a slideable rod 112 connected to a slideable "sled" 113 having a 1/4 inch (0.63 centimeters) wide slot 114 through which vacuum is applied to the sample, a pneumatic cylinder 115 for propelling the sled underneath the sample, and a shock absorber 116 for receiving and stopping the rod. In operation, the vacuum tank is evacuated as indicated by arrow 117 to the desired vacuum level via a suitable vacuum pump. The handsheet, while still in the handsheet mold and having one side is still in contact with the forming fabric of the handsheet mold and at the desired consistency, is placed "upside down" in the sample holder of the illustrated apparatus such that the other side of the handsheet is in contact with the throughdryer fabric of the sample holder. The pneumatic cylinder is then pressurized with nitrogen gas to cause the rod 112 and the connected sled 113 to move at a controlled speed toward the shock absorber at the end of the apparatus. In so doing, the slot in the sled briefly passes under the sample holder as shown and thereby briefly subjects the sample to the vacuum, thereby mimicking a continuous process in which the tissue is moving and the vacuum slot is fixed. The brief exposure to vacuum wet strains the sample as it is transferred to the throughdrying fabric in the sample holder. The handsheet is then dried to final dryness while supported by the throughdrying fabric by any suitable noncompressive means such as throughdrying or air drying. In all of the examples described herein, the speed of the sled was 2000 feet per minute (10.1 meters per second) and the level of vacuum was 25 inches of mercury.
DEBONDED VOID THICKNESS
The method for determining the Debonded Void Thickness (DVT) is described below in numerical stepwise sequence, referring to FIGS. 8-13 from time to time. In general, the method involves taking several representative cross-sections of a tissue sample, photographing the fiber network of the cross-sections with a scanning electron microscope (SEM), and quantifying the spaces between fibers in the plane of the cross-section by image analysis. The total area of spaces between fibers divided by the frame width is the DVT for the sample.
A. Specimen Sandwiches
1. Samples should be chosen randomly from available material. If the material is multi-ply, only a single ply is tested. Samples should be selected from the same ply position. The same surface is designated as the upper surface and samples are stacked with the same surface upwards. Samples should be kept at 30° C. and 50 percent relative humidity throughout testing.
2. Determine the machine direction of the sample, if it has one. The cross-machine direction of the sample is not tested. The cross-section will be cut such that the cut edge to be analyzed is parallel to the machine direction. For strained handsheets the cut is made perpendicular to the wire knuckle pattern.
3. Place about five inches (127 millimeters) of tape (such as 3M Scotch™ Transparent Tape 600 UPC 021200-06943), 3/4 inch (19.05 millimeters) width, on a working surface such that the adhesive side is uppermost. (The tape type should not shatter in liquid nitrogen).
4. Cut three 5/8 inch (or 15.87 millimeters) wide by about 2" (or 50.8 millimeters) long specimens from the sample such that the long dimension is parallel to the machine direction.
5. Place the specimens on the tape in an aligned stack such that the borders of the specimens are within the tape borders (see FIG. 8). Specimens which adhere to the tape will not be usable.
6. Place another length of tape of about 5 inches (or 127 millimeters) on top of the stack of specimens with the adhesive side towards the specimens and parallel to the first tape.
7. Mark on the upper surface of the tape which is the upper surface of the specimen.
8. Make twelve specimen sandwiches. One photo will be taken for each specimen.
B. Liquid Nitrogen Sample Cutting
Liquid nitrogen is used to freeze the specimens. Liquid nitrogen is dispensed into a container which holds the liquid nitrogen and allows the specimen sandwich to be cut with a razor blade while submerged. A VISE GRIP™ pliers can hold the razor blade while long tongs secure and hold the specimen sandwich. The container is a shallow rigid foam box with a metal plate in the bottom for use as a cutting surface.
1. Place the specimen sandwich in a container which has enough liquid nitrogen to cover the specimen. Also place the razor blade in the container to adjust to temperature before cutting. A new razor blade must be used for each sandwich to be cut.
2. Grip the razor blade with the pliers and align the cutting edge length with the length of the specimen such that the razor blade will make a cut that is parallel with the machine direction. The cut is made in the middle of the specimen. (See FIG. 8).
3. The razor blade must be held perpendicular to the surface of the specimen sandwich. The razor blade should be pushed downward completely through the specimen sandwich so that all layers are cleanly cut.
4. Remove the specimen sandwich from the liquid nitrogen.
C. Metal Stub Preparation
1. The metal stubs' dimensions are dictated by the parameters of the SEM. The dimensions as illustrated in FIG. 9 are about 22.75 millimeters in diameter and about 9.3 millimeters thick.
2. Label back/bottom of stub with the specimen name.
3. Place a length of two-sided tape (3M Scotch™ Double-Coated Tape, Linerless 665, 1/2 inch [or about 12.7 millimeters] wide) across the diameter of the stub. (See FIG. 9).
4. Place about a 1/4 (or about 6.35 millimeters) length of 1/8 inch (or about 3.17 millimeters) diameter carbon rod (manufacturer: Ted Pella, Inc., Redding, Calif., 1/8" [or 3.17 millimeters] diameter by 12-inch [or 304.8 millimeters] length, Cat. #61-12) at one end of the tape within the edges of the stub such that its length is perpendicular to the length of the tape. This marks the top of the stub and the upper surface of the specimen.
5. Place a longer rod below the short rod. The length of the rod should not extend beyond the edge of the stub and should be approximately the length of the specimen.
6. Cut the specimen sandwich perpendicular to the razor cut at the ends of the razor cut (see FIG. 8).
7. Remove the inner specimen and place standing up next to (and touching) the carbon rod such that its length is parallel to the rod's length and its razor cut edge is uppermost. The upper surface of the specimen should face the small carbon rod.
8. Place another carbon rod approximately the length of the specimen next to the specimen such that it is touching the specimen. Again, the rod should not extend beyond the disk edges.
9. Repeat specimen, rod, specimen, rod until the metal stub is filled with four specimens. Three stubs will be used for the procedure.
D. Sputter Coating the Specimen
1. The specimen is sputter coated with gold (Balzar's Union Model SCD 040 was used). The exact method will depend on the sputter coater used.
2. Place the sample mounted on the stub in the center of the sputter coater such that the height of the sample edge is about in the middle of the vacuum chamber, which is about 11/4 inches (or 31.75 millimeters) from the metal disk.
3. The vacuum chamber arm is lowered.
4. Turn the water on.
5. Open the argon cylinder valve.
6. Turn the sputter coater on.
7. Press the SPUTTERING button twice. Set the time using SET and FAST buttons. Three minutes will allow the specimen to be coated without over-coating (which could cause a false thickness) or under coating (which could cause flaring).
8. Press the STOP button once so it is flashing. Press the TENSION button at this time. The reading should be 15-20 volts. Hold the TENSION button down and press CURRENT UP and hold. After about a ten-second delay, the reading will increase. Set to approximately 170-190 volts. The current will not increase unless the STOP button is flashing.
9. Release the TENSION and CURRENT UP buttons as you turn the switch on the arm to the green dot to open the window. The current should read about 30 to 40 milliamps.
10. Press the START button.
11. When completed, close the window on the arm and turn the unit off. Turn off the water and argon. Allow the unit to vent before the specimen is removed.
E. Photographinq with the SEM (JEOL, JSM 840 II, distributed by Japanese Electro Optical Laboratories, Inc. located in Boston, Mass.). A clear, sharp image is needed. Several variables known to those skilled in the art of microscopy must be properly adjusted to produce such an image. These variables include voltage, probe current, F-stop, working distance, magnification, focus and BSE Image wave form. The BSE wave form must be adjusted up to and slightly beyond the reference limit lines in order to obtain proper black-&-white contrast in the image.
These variables are adjusted to their optimum to produce the clear, sharp image necessary and individual adjustments are dependent upon the particular SEM being used. The SEM should have a thermatic source (tungsten or Lab 6) which allows large beam current and stable emission. SEMs which use field emission or which do not have a solid state back scatter detector are not suitable.
1. Load the stub such that the specimen's length is perpendicular to the tilt direction and lowered as far as possible into the holder so that the edge is just above the holder. Scan rotation may be necessary depending on the SEM used.
2. Adjust the working distance (39 millimeters was used). The specimen should fill about 1/3 of the photo area, not including the mask area. (For handsheets, a magnification of 150x was used.)
3. Use the tilt angle of the SEM unit to show the very edge of the specimen with as little background fibers as possible. Do not select areas that have long fibers that extend past the frame of the photo.
4. One photomicrograph is taken using normal film (POLAROID 54) for gray levels for comparison. The F-stop may vary. The areas selected should be representative and not include long fibers that extend beyond the vertical edge of the viewing field.
5. Without moving the view, take one photomicrograph using back scatter electrons with high contrast film (51 Polaroid). The F-stop may vary. A sharp, clear image is needed. After the photomicrographs are developed, a black permanent marker is used to black out background fibers that are out of focus and are not on the edge of the specimen. These can be selected by comparing the photomicrograph to the gray level photomicrograph of Step 4 above. (See FIGS. 10 and 11.)
6. A total of twelve photomicrographs are taken to represent different areas of the specimens; one photomicrograph is taken of each specimen.
7. A protective coating is applied to the photo on 51 film.
F. Image Analysis of SEM Photos
1. The 12 photos are arranged into two montages. Six photos are used in each montage. Make two stacks of six photos each, and cut the white framing off the left side of one and the white framing off the right side of the remaining stack without disturbing the photos. (See FIG. 12.)
2. Then, taking one photo from each stack, place cut edges together and tape together with the tape on the back of the photo (3M Highland™ Tape, 3/4 inch [or 19.05 millimeters]). No extraneous white of the background should show at the cut, butted edges.
3. Arrange the photos with a small overlap from top to bottom as in FIG. 13.
4. Turn on the image analyzer (Quantimet 970, Cambridge Instruments, Deerfield, Ill.). Use a 50 mm. El-Nikkor lens with C-mount adaptor (Nikon, Garden City, N.Y.) on the camera and a working distance of about 12 inches (305 millimeters). The working distance will vary to obtain a sharp clear image on the monitor and the photo. Make sure the printer is on line.
5. Load the program (described below).
6. Calibrate the system for the photo magnification (which will generate the calibration values indicated by "x.xxxx" in the program listed below), set shading correction with white photo surface (undeveloped x-ray film), and initialize stage (12 inches by 12 inches open frame motor-driven stage (auto stage by Design Components, Inc., Franklin, Mass.)) with step size of 25 microns per step.
7. Load one of the two photo montages under a glass plate supported on the stage after strips of black construction paper are placed over the white edges of the photos. The strips are 3/4 inch wide (18.9 millimeter) and 11 inches long (279 millimeters) and are placed as in FIG. 13 so that they do not cover the image in the photo. The montage is illuminated with four 150 watt, 120 volt GE reflector flood lamps positioned with two lamps positioned at an angle of about 30° on each side of the montage at a distance of about 21 inches (533 millimeters) from the focus point on the montage.
8. Adjust the white level to 1.0 and the sensitivity to about 3.0 (between 2 and 4) for the scanner using a variable voltage transformer on the flood lamps.
9. Run the program. The program selects twelve fields of view: two per photomicrograph.
10. Repeat at the pause with the second montage after completion of twelve fields of view on the first montage.
11. A printout will give the Debonded Void Thickness.
__________________________________________________________________________G. Computer Program.__________________________________________________________________________ Enter specimen identityScanner (No. 2 Chalnicon LV = 0.00 SENS = 1.64 PAUSE)Load Shading Corrector (pattern - OFOSU3)Calibrate User Specified (Calibration Value = x.xxxx microns per pixel) (PAUSE)CALL STANDARDTOTDEBARE : = 0.For SAMPLE = 1 to 2Stage Scan ( X Yscan origin 10000.0 10000.0field size 16500.0 11000.0no. of fields 3 4 )Detect 2D (Lighter then 32 PAUSE)For FIELDScanner (No. 2 Chalnicon AUTO-SENSITIVITY LV = 0.00)Live Frame is Standard Live FrameDetect 2D (Lighter than 32)Amend (OPEN by 1)Measure field - Parameters into array FIELDRAWAREA: = FIELD AREAAmend (CLOSE by 20)Image Transfer from Binary B (FILL HOLES) to Binary OutputMeasure field - Parameters into array FIELDFILLAREA: = FIELD AREADEBNAREA: = FILLAREA - RAWAREATOTDEBARE: = TOTDEBARE + DEBNAREAStage StepNext FIELDPauseNextFIELDNUM: = FIELDNUM * (SAMPLE - 1.)Print " "Print "DEBOND VOID THICKNESS =", ( TOTDEBARE / FIELDNUM)/(625.* CAL.CONSTPrint " "For LOOPCOUNT = 1 to 7Print " "NextEnd of Program__________________________________________________________________________
EXAMPLES
In order to further illustrate the invention, a number of handsheets were prepared as follows:
The pulp was dispersed for five minutes in a British pulp disintegrator. Circular handsheets of four-inch diameter, conforming precisely to the dimensions of the sample holder used for wet-straining, were produced by standard techniques. The sample holder contained a 94-mesh forming fabric on which the handsheets were formed. After formation the handsheets were at about 5 percent consistency. For those samples not wet-pressed (Example 1), the samples were dried to the consistency selected for wet-straining by means of a hot lamp and then wet-strained. For those experiments involving pressing (Example 2), the handsheet was removed from the sample holder by couching with a dry blotter. The sheet was then pressed in an Allis-Chalmers Valley Laboratory Equipment press. Pressing time and/or pressure were varied to achieve the desired post-pressing consistency. Selected samples were then wet-strained.
Wet-straining of the handsheets was performed using the apparatus previously described in reference to FIG. 14. In all cases, a sample holder containing an Asten 934 throughdrying fabric was placed in the wet-straining apparatus. When the base sheet reached the desired consistency, either by pressing or drying with the lamp, the holder on which the sheet was formed was placed "upside down" in the straining apparatus such that the surface of the sheet not in contact with the forming fabric came in contact with the surface of the throughdrying fabric. A sled was then caused to slide underneath the sample holders exposing the sheet to vacuum, causing the sheet to be wet-strained and transferred to the throughdrying fabric. In all cases, a sled speed of 2000 fpm and a vacuum of 25 inches of mercury were utilized. The sheet, now located on the throughdrying fabric, was then dried to complete dryness in a noncompressive manner.
Example 1
Handsheets were made from a 100 percent eucalyptus furnish and dried with a hot lamp to various consistencies prior to wet-straining as described above. After wet-straining, various physical parameters were measured as shown in TABLE 1 below. (Sample weight is expressed in grams; Consistency is expressed in weight percent; Tensile strength is expressed as grams per inch of sample width; Normalized tensile strength is the tensile strength divided by the sample weight, expressed as reciprocal inches; Debonded Void Thickness is expressed as microns; and Normalized Debonded Void Thickness is the Debonded Void Thickness divided by the sample weight, expressed as microns per gram.)
TABLE 1______________________________________ Normalized Consistency Norm- Debonded DebondedSample Prior to alized Void VoidWeight Wet Straining Tensile Tensile Thickness Thickness______________________________________0.305 13.2 420 1377 86.1 282.30.235 33.6 396 1685 84.1 357.90.227 46.3 255 1123 82.6 363.9______________________________________
For comparison, an air-dried control sample (not wet-strained) weighing 0.238 grams had a tensile strength of 460 grams, a normalized tensile of 1933, a Debonded Void Thickness of 73 microns, and a Normalized Debonded Void Thickness of 306.7 microns per gram.
These results clearly show that wet-straining can be used to increase the void area relative to the weight of the sheet. As the data indicates, conducting the wet-straining at only 13 percent consistency (below the level claimed in this application) did not result in a significant increase in Normalized Debonded Void Thickness. Instead the sheet was primarily molded to the shape of the fabric. However, for the samples wet-strained at higher consistency, a definite increase in the Normalized Debonded Void Thickness was apparent and the tensile strength (a measure of bonding in the sheet) significantly decreased. Hence wet straining becomes effective at approximately 30 percent consistency or greater, with an optimum wet-straining consistency varying with furnish, fabric, etc. However, the optimum consistency is believed to lie in the 40-50 percent range.
Example 2
Handsheets nominally weighing 0.235±0.200 grams were made from a 50/50 blend by weight of eucalyptus and spruce fibers. One set of handsheets was pressed to various consistencies (not wet strained) to serve as a control. Another set was pressed to approximately 50 percent consistency and then wet strained as described above. Consistencies, sample weights and the Debonded Void Areas were measured for each sample. The data is tabulated in TABLE 2 below and further illustrated in FIG. 15. The first six samples listed represent the control samples. The last five samples are the wet-strained samples.
TABLE 2______________________________________ Post Normalized Pressing Norm- Debonded DebondedSample Con- alized Void VoidWeight sistency Tensile Tensile Thickness Thickness______________________________________0.252 30.7 662 2627 73.2 290.50.224 31 760 3393 56.5 252.20.237 34.9 684 2886 72.6 306.30.241 35 761 3158 59.1 245.20.228 58.5 1195 5241 31.5 138.20.229 60.3 1207 5271 29 126.60.224 51.3 774 3455 58.6 261.60.246 51.5 887 3606 64.2 2610.23 52.6 848 3687 63.1 274.30.229 54.3 1029 4493 38.9 169.90.241 58.9 826 3427 55.2 229AVER- 53.72 239.2AGE______________________________________
As shown in FIG. 15, the line in this figure is a regression line for the control data according to the equation: Normalized Debonded Void Thickness=444.5-(5.22×Consistency). As expected, the Normalized Debonded Void Thickness linearly decreased with pressing. While pressing is an effective means for removing water, it causes densification that reduces the Normalized Debonded Void Thickness and makes the resulting sheet less bulky and absorbent.
Also shown in FIG. 15 are the data points for the five wet straining samples and the arithmetic average for the five samples. The average Normalized Debonded Void Thickness of 239.2 at an average consistency of 53.7 percent was 46 percent higher than the predicted value of 163.8 at 53.7 percent consistency from the regression equation. This increase in Normalized Debonded Void Thickness is the desired result of the wet straining operation.
Hence it is clear that wet straining can be used to significantly increase the Debonded Void Thickness of paper. The benefits of this process can be manifested as higher Debonded Void Thickness at a given level of pressing or as the ability to press to a higher consistency while maintaining a given level of Debonded Void Thickness. Which approach is best depends on the amount of bulk and absorbency desired for a given product and the limitations of the particular papermaking process being utilized. In either case, an improved product can be produced via wet straining in accordance with this invention.
It will be appreciated that the foregoing examples, given for purposes of illustration, are not to be construed as limiting the scope of this invention, which is defined by the following claims and all equivalents thereto.
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The internal bulk of a tissue web can be improved during manufacturing of the basesheet by subjecting the tissue web to differential pressure while supported on a coarse fabric at a consistency of about 30 percent or greater. The differential pressure, such as by applying vacuum suction to the underside of the coarse fabric, causes the wet web to deflect into the openings or depressions in the fabric and "pop" back, resulting in a substantial gain in thickness or internal bulk. The method is especially adapted to improve the internal bulk of wet-pressed tissue webs.
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BACKGROUND OF THE INVENTION
This invention relates to an electrophotographic copying machine incorporating a mechanism which computes and selects desired magnification or copy paper size according to detected or input document (text paper) size.
Recently, a wide variety of electrophotographic copying machines with variable magnification, used to perform photocopying by enlarging or reducing document images, have been commercialized. When photocopying with these electrophotographic copying machines, document size, desired magnification and copy paper size must be determined. For this reason, some copying machines incorporate document size detectors in the plate (document table). A plurality of optical sensors are placed under the plate in positions corresponding to the right end of a documents of specific size so that copy paper size matching the maximum sensor position--out of multiple sensors--is defined as the document size. This copying machine incorporates a mechanism which computes and selects a document size upon entry of data on desired magnification or a desired magnification based on entry of data on document size as identified by the said detector and on operator-input magnifications or copy paper size. However, when an unformatted document sized between B5 and A4 is placed on the plate, its right end comes to a point between the B5R and A4 sensors. In this instance, the A4 sensor, but not B5R sensor, detects the document inserted. The document size detector therefore detects the document as if it is of A4 size and photocopies in variable magnifications based on operator-specified magnification or copy paper size. However, since the unformatted document is longer than A4 paper in the exposure scanning direction, copying would allow an enlarged image to overflow the copy paper used, generating waste.
Thus conventional copying machines with variable magnifications equipped with document size detectors generate waste copies when reproducing unformatted or irregular sized documents, thereby substantially lowering operating efficiency.
SUMMARY OF THE INVENTION
The object of the present invention is to provide, in view of these drawbacks, a photocopying machine capable of preventing the production of faulty copies in such a situation and which improves copying machine operating efficiency by incorporating a means for selecting a predetermined variable magnification or suitable magnification when photocopying unformatted documents in variable magnifications.
Other objects and the further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art after reading this detailed description.
This invention relates to an electrophotographic copying machine characterized by the provision of both an unformatted document identification key used to photocopy irregularly-sized documents and an unformatted document entry function, which allows such a document to be input after key operation, and by incorporating a mechanism which computes and selects a desired magnification or copy paper size using input information entered via said input device.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood from the detailed description given hereinafter and the accompanying drawings, given by way of illustration only, which are not limitative of the present invention.
FIGS. 1(A) and (B) are flow charts which illustrate the operation of the electrophotographic copying machine embodying the present invention.
FIG. 2 is a diagrammatic illustration of its control unit.
FIG. 3 illustrates a platen provided with a document size detector, and
FIG. 4 is a block diagram of the electrophotographic copying machine circuitry.
DESCRIPTION OF THE INVENTION
FIG. 2 illustrates the control unit of the copying machine embodying the present invention.
An indicator (2) is located near the center of the control unit (1). A numeric key (3) and COPY button (24) are located to the right of indicator (2). A numeric indicator (4), to the right of indicator (2), shows the number of copies to be reproduced as input from numeric key (3), or unformatted document size. Beneath the numeric indicator an interrupt key (13) and a repeat key (14) are found. A warning indicator (5) to the left of numeric indicator (4) alerts the operator of the need for toner refill or machine jamming by means of schematic illustration. An exposure indicator (16) indicates exposure density controlled by exposure control key (11), located below the indicator. An automatic exposure indicator (15) indicates the automatic exposure value selected using automatic exposure selection key (12). A variable magnification indicator (6), located near the center of indicator (2), indicates variable magnification values input from variable magnification selection key (9) and zoom key (10). A cassette-sized indicator (7) shows the size of copy paper housed in each of the cassettes installed in three stacks within the paper feed unit of the copying machine (not shown). A cassette selection key (8) located beneath indicator (7) indicates the selected cassette. A document size indicator (19) to the left of indicator (2) indicates document size as identified by the document size detector or input by the operator. A copy size indicator (20) indicates input magnification and copy paper size computed from the document size or selected using copy size selection key (21) beneath indicator (20). A photocopy paper size indicator (17) indicates the copy paper cassette size computed from document size and desired magnification when such cassette is not mounted. A document position indicator (18) tells the operator to change incorrect document orientation on the plate if improperly oriented or not suitable for predetermined magnification or copy paper size. An automatic copy paper/magnification selector key (22) is pressed when data on copy paper size and desired magnification is entered manually. An unformatted document mode key (23) invalidates, upon copying unformatted (irregular sized) documents, specific magnifications or copy paper size computed by means of identified document size. A lateral input key (25) and longitudinal input key (26) underneath are operated when data on unformatted document size is entered via numeric key (3).
As shown in FIG. 3, the document size detector in the copying machine consists of a plurality of optical sensors (31) located under the plate. Each sensor (31) position corresponds to the right end of a specific-size document placed on the plate, so that copy paper size matching the maximum sensor position--out of multiple sensors--is defined as the document size. This copying machine incorporates a mechanism which computes and selects document size on entry of data on desired magnification, or a desired magnification based on entry of data on document size as identified by the said detector and on operator-input magnification or copy paper size.
However, the detector itself (FIG. 3) has no direct bearing on the essential point of this invention.
FIG. 4 is a block diagram of the copying machine embodying this invention, equipped with the unformatted document size invalidating function.
The CPU (120) is connected, via an internal bus, to ROM (121), which stores the programs that control the various functions of the copying machine and data on usable formatted paper sizes; I/O (122) is linked with control unit (114) and the document (124) on the plate and to RAM (123), which stores both I/O (122) input signals and computation results.
The document size detector (124) corresponds to the device in FIG. 3 and its control unit (114) in FIG. 4.
FIGS. 1 (A) and (B) show the operation of the electrophotographic copying machine with variable magnification.
After a document is placed on the plate, the size of this document is detected by the document size detector (FIG. 3) at step n1 (hereafter referred to as "n1"). Next, size P, detected in n2, is stored in RAM (123), and at n3, copy paper size is computed and selected on the basis of the document size and existing variable magnification. At n4, the detector determines if an unformatted document mode key was depressed. If not, control moves on to n5, where the number of copies to be reproduced is set via numeric key (3). The machine then determines if PRINT button (24) was depressed; if not, control returns to n3. When the PRINT button (24) is pressed at n6, control moves on to n7 and initiates the copying cycle. Each time the copying cycle terminates at n8, the number of copies reproduced are deducted from the initial count and the balance is indicated at n9. At n10, the machine determines if the CLEAR key was pressed; if not, the machine determines if the copying cycle or all copies to be reproduced has been terminated at n12. If not completed at n12, control returns to n7 to repeat the copying cycle. If the CLEAR key is pressed at n10 or if the copying cycle for all copies to be reproduced has been terminated at n12, document reproduction stops.
If the unformatted document mode key was pressed at n4, the machine performs computations using the document size P, stores copy paper size and turns off the READY lamp at n14. Control then moves on to n15 and n16, where the lateral length A and longitudinal length B of an unformatted document are stored in RAM (123) by means of the lateral input key (25), longitudinal input key (26) and numeric key (3). At n17, depression of a copy paper size selection key (21) enables selection of copy paper size. Later, at n18, computation of ratios (X and Y) of lateral and longitudinal lengths of the unformatted document and copy paper are made on the basis of data stored in RAM (123); a comparison is made of the two ratios (X) and (Y) at n19. If lateral ratio (Y) is greater, control moves on to n20; if longitudinal ratio (X) is greater, control moves on to n21. In other words, the smaller longitudinal and lateral ratios in n19, n20 and n21 are selected as variable magnifications. Then, at n22 and n23, the lens is moved to a position where variable magnifications obtained can be executed. When lens transfer has been completed at n23, READY lamp goes on at n24 and control returns to n5.
A series of these operations make it possible to store, when copying unformatted documents, variable magnifications or copy paper sizes computed and selected with the aid of detected document sizes and allows high priority for a photocopying operation using desired magnifications as computed from document and copy paper sizes, which are manually input by an operator.
The operation is designed to compute desired magnifications from the size of unformatted documents input by an operator and predetermined copy paper sizes. Similarly, it is also possible to compute image expandability and select adequate copy paper size based on the size of manually input unformatted document size and predetermined magnifications.
The system configuration embodied in the present invention enables, when copying unformatted documents, the selection of a copy paper size or a desired magnification adapted to the size of document to be copied, thereby preventing waste resulting from faulty reproduction of unformatted documents and concurrently improving copying machine operating efficiency.
While only certain embodiments of the present invention have been described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as claimed.
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An electrophotographic copying machine for determining a variable magnification ratio based upon both automatically sensed copy document size information and manually input copy document size information to eliminate copying errors when copying unformatted sized copy documents onto standard size copy paper.
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This application is a continuation of and hereby claims priority to, pending U.S. patent application Ser. No. 12/211,716, entitled “Automated Submission of Prepaid Programs,” filed on Sep. 16, 2008, which is a nonprovisional application of and claims benefit of U.S. Provisional Patent Application No. 60/976,215, titled Automated Submission of Prepaid Programs, filed on Sep. 28, 2007.
FIELD
The present invention relates to prepaid payment programs, such as debit accounts and gift payment cards, that are sponsored for a program issuer by a transaction handler; and in particular to automated submission of information by the program issuer to the transaction handler for creating a new prepaid payment program.
BACKGROUND
Payment transaction processing systems have been created to enable consumers to pay for products and services at merchants without exchanging money at the time of the purchase. An exemplary transaction processing system 100 , depicted in FIG. 1 , includes an issuer 104 of a payment account for use by a consumer 102 ; a transaction handler 106 , such as a credit card company; an acquirer 108 ; and a merchant 110 . Payment cards are issued to individual people and to business entities, thus the consumer 102 may be a person to whom the payment card was issued or may be a person having access to the card funds, such as an employee of a business entity to which the payment card was issued. When a payment card is issued, the issuer 104 often provides a portable payment device 112 for use by the consumer 102 . Examples of portable payment devices include a credit or debit card, a gift card, a smartcard, a smart media, a payroll card, a health care card, a wrist band, a machine readable medium containing account information, a keychain device such as the SPEEDPASS® commercially available from ExxonMobil Corporation or a supermarket discount card, a cellular phone, personal digital assistant, a pager, a security card, a computer, an access card, a wireless terminal, a contactless sticker or a transponder. The portable payment device 112 may have a volatile or non-volatile memory to store information such as the card number or an cardholder's name.
A typical transaction begins with the consumer 102 presenting an card that has a number, such as through the use of a computer terminal or a portable payment device 112 , to the merchant 110 to pay for the purchase of a product or service. The merchant 110 may utilize a Point of Service (POS) terminal 114 to obtain a payment card number from the portable payment device 112 . The portable payment device 112 may interface with the POS terminal using a mechanism including any suitable electrical, magnetic, or optical interfacing system. The POS terminal 114 is in operative communication with the transaction processing system 100 and can communicate with the acquirer 108 , the transaction handler 106 , or the issuer 104 . For a usual purchase transaction, the POS terminal sends a transaction authorization request to the issuer 104 of the portable payment device 112 . Alternatively, or in combination, the portable payment device 112 may communicate with the issuer 104 , the transaction handler 106 , or the acquirer 108 .
The issuer 104 responds by authorizing or denying the transaction authorization request using the transaction handler 106 . Authorization includes the issuer 104 , or the transaction handler 106 on behalf of the issuer 104 , authorizing the purchase transaction in compliance with the issuer's 104 instructions, such as through the use of business rules. A message indicating authorization or denial of the transaction authorization request is sent back through the transaction handler 106 to the merchant 110 . The transaction handler 106 may maintain a log or history of authorized transactions. Once approved, the merchant 110 records the authorization and delivers the product or service to the consumer 102 .
The merchant 110 may, at discrete periods, such as the end of the day, submit a list of authorized transactions to the acquirer 108 or other components of the transaction processing system 100 . The transaction handler 106 may compare the submitted authorized transaction list with its own log of authorized transactions. If a match is found, the transaction handler 106 may route authorization transaction amount requests from the corresponding acquirer 108 to the corresponding issuer 104 involved in each transaction. Once the acquirer 108 receives the payment of the authorized transaction amount from the issuer 104 , it can forward the payment to the merchant 110 less any transaction costs, such as fees. If the transaction involves a debit or prepaid card, the acquirer 108 may choose not to wait for the initial payment prior to paying the merchant 110 .
There may be intermittent steps in the foregoing process, some of which occur simultaneously. For example, the acquirer 108 can initiate the clearing and settling process, which can result in payment to the acquirer 108 for the amount of the transaction. The acquirer 108 may request from the transaction handler 106 that the transaction be cleared and settled. Clearing includes the exchange of financial information between the issuer 104 and the acquirer 108 , and settlement includes the exchange of funds. The transaction handler 106 can provide services in connection with settlement of the transaction. The settlement of a transaction involves an issuer 104 withdrawing an amount of a transaction settlement from a clearinghouse, such as a clearing bank, for deposit into a settlement house, such as a settlement bank. The corresponding acquirer 108 withdraws the amount of the transaction settlement from the settlement bank. Typically, the settlement bank is chosen by the transaction handler 106 , and the clearing bank is chosen by the acquirer 108 . Thus, a typical transaction involves various entities to request, authorize, and fulfill the processing of the transaction for clearing and settlement.
Some transactions involve a prepaid card in which a given amount of money has been deposited in a card account for use by a consumer. One type of a prepaid program is an employee benefits card, examples of which are a health savings account that is limited to paying for health care related expenses or in which an employer deposits money for use by an employee to pay for specified products and services, such as mass transit fares. There are many types of prepaid cards (gift, travel, youth, general purpose, etc.) that are purchased by a consumer some are might have a pre-defined monetary value like in the case of gift cards ($25, 50, 100) and other will allow the consumer to load a variable amount that can be used to buy products and services, often from any visa merchant.
Unlike cards for a generic credit or debit card, any card accounts related to a prepaid program must first be approved by the transaction handler, which as noted above may be a conventional credit card company, such as Visa, Inc. Heretofore, the establishment of a prepaid program involves an issuer or an agent acting on behalf of an issuer preparing a written application for a new prepaid program. The application required that various specified items of information be provided by the preparer in order to define the type of program and its parameters. In certain programs, a custom portable payment device was issued that included a logo and other information for the particular program or the sponsor of that program. The completed written form and any artwork for the customized portable payment device then submitted electronically to the transaction handler for programs managed by that company. Upon receipt, the submitted materials are routed via electronic means to the proper departments that process the prepaid program applications.
Previously, an agent of an issuer could prepare and submit an application for a prepaid program in the name of the issuer. In many instances, however, the agent was not fully aware of operational guidelines and other restrictions promulgated by the transaction handler for particular types of prepaid programs. In addition, the agent was not always aware of other requirements of the associated issuer. As a consequence, an agent could create a prepaid program on behalf of an issuer even though the nature of the prepaid program conflicted with that issuer's guidelines and restrictions. This presents a need for greater control of the application process for prepaid programs to ensure conformity with the requirements, restrictions, and guidelines.
Upon receiving an application for a prepaid program, the transaction handler reviewed the contents of the application form. If errors or incomplete information were found on the form, the application was returned to the originator for correction. Therefore, at best, the process for creating a new prepaid program could take weeks depending upon the delivery time for each exchange of the written information and the amount of time necessary to ultimately get a properly completed application.
Therefore, it is desirable to improve the process for approving prepaid programs to reduce the amount of time, eliminate many of the common errors in the application, and enable the transaction handler to track the progress of each application through the review process.
SUMMARY
A transaction processing system enables a transaction handler to process business transactions, each characterized by a consumer and a merchant engaging in a sales transaction upon an account that was provided to the consumer by an issuer. Some of the sales transactions involve prepaid cards, such as those like a gift card, for example. The prepaid cards are part of a prepaid program, various types of which have different requirements that have been imposed by law, the issuer, or the transaction handler. Therefore, it is important when a prepaid program is to be created/approved that all the necessary information be provided by the requesting issuer and that the proposed prepaid program complies with the associated requirements.
A method for establishing a prepaid program, having at least one card provided by the issuer, involves the issuer remotely accessing a computer system at the transaction handler. For example, the transaction handler may have an Internet website for this purpose. The computer system presents a program information form to the issuer, which responds by providing data requested on the program information form. In a preferred embodiment, the computer system checks the correctness of the data entered on the form and informs the issuer of any errors. The issuer then can access the previously submitted program information form on-line to correct the erroneous data.
When the issuer has completed the program information form, it is submitted as a request to create a prepaid program. In addition, collateral materials related to a portable payment device to be used and instructional materials for prepaid program may be submitted at the same time for review by the transaction handler. The transaction handler reviews the data and other materials that were submitted and approves or rejects creation of the prepaid program. The transaction handler then electronically communicates approval or rejection of the prepaid program to the issuer.
BRIEF DESCRIPTION OF THE DRAWINGS
Implementations of the invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like elements bear like reference numerals.
FIG. 1 is a block diagram illustrating an exemplary transaction processing system;
FIG. 2 is a flowchart depicting the on-line process for submitting and reviewing information to create a new prepaid program;
FIG. 3 illustrates an exemplary main menu from which a user accesses different components of the information submission procedure;
FIG. 4 portrays a computer screen that displays a portion of a program information form by which a user submits information for creating a prepaid program; and
FIG. 5 portrays a computer screen that displays another portion of the program information form.
DESCRIPTION
The present implementations facilitate an automated submission of information for creating a prepaid program from the issuer 104 to the transaction handler 106 through a secure on-line platform. A prepaid program, as used herein, is a program within the transaction processing system 100 which is centered around an card account having a monetary deposit with the issuer 104 that provided the card. Examples of the prepaid cards include: a stored value card, a gift card, a campus/student disbursement program, a health savings account card, an employee health/wellness card, a flexible spending account card, and a transit/parking employee benefit card.
In order to create a new prepaid program, an issuer 104 accesses the secure on-line platform operated by the transaction handler 106 , and submits information defining the prepaid program, as well as optional collateral materials related to a portable payment device and instructional materials for that program. The transaction handler 106 reviews that submission and authorizes or denies the new prepaid program. That decision is communicated to the originating issuer.
With reference to FIGS. 1 and 2 , the process 200 by which a person at the issuer 104 submits information to the transaction handler 106 for creating a new prepaid program commences at step 201 by the issuer accessing a portal 115 of a computer system 116 at the transaction handler 106 . In one implementation, the portal includes a website of the transaction handler on the Internet. From the home page of that website, the issuer 104 is able to select the prepaid program function and be connected to that function running on the computer system 116 . That access provides a web-enabled graphical user interface (GUI) which is displayed on a personal computer 120 at the issuer 104 using commercially available web browser software. Thus the issuer is not required to have any special software to interface on-line with the prepaid program function at the transaction handler 106 . Alternatively, access to the computer system 116 can be provided by a dial-up telephone connection or other point-to-point communication link.
Regardless of the communication link that is used, once the issuer 104 accesses the computer system 116 at the transaction handler 106 , the issuer is asked to enter a user identification and a password, which thereby restricts access to the computer system to only authorized entities. Other types of security measures for restricting access also may be utilized. The transaction handler 106 then compares the user identification and password to sets of such identifiers and passwords stored in a database of authorized entities. If the newly submitted user identifier and password match a set for an authorized entity, the issuer 104 is granted access to the computer system 116 and specifically to the prepaid program function at step 201 .
Upon successfully accessing the prepaid program function, the process advances to step 202 at which a main menu is sent to the issuer, where it is displayed on a monitor of the personal computer 120 . FIG. 3 depicts a basic example of the main menu which presents three options to the issuer. Those options are to create a new submission, access a previously stored information form or to check the status of a previous submission. The user places a check mark in the box next to the desired item and then clicks the NEXT button to advance to the section of the on-line process for the selected item.
Assume that the issuer 104 desires to create a new submission, the process advances to step 204 where the transaction handler 106 assigns a unique tracking number to this submission. The tracking number enables the submission to be identified and subsequently accessed by entities within the transaction handler 106 .
Then at step 207 , a program information form is displayed on the issuer's computer monitor. The program information form has a number of blanks that are to be filled in by the issuer at step 208 with information required to create a new prepaid program. An exemplary first page of that program information form (PIF) is illustrated in FIG. 4 . On that page, the issuer 104 is asked for its name or the name of the transaction processing system member that is co-sponsoring the proposed prepaid program. Areas are also provided for entering the address of that entity. After entering an item of information on the program information form, the issuer utilizes the mouse to click on another data entry field to enter the next item of data. If the issuer and another member of the payment system are sponsoring the program, then the name and address of that sponsored member is entered on this page of the form. The identity of the person at the issuer submitting this form and that individual's email address also are entered in order that communications related to the submission can be sent to that submitter. Once the first page of the program information form has been completed, the issuer clicks on the NEXT button to advance to the second page of that form which is shown in FIG. 5 .
On this next page, the issuer enters information defining the type of prepaid program being created and certain parameters associated with that program. A payment account number within the transaction processing system comprises a business identification number (e.g. 6 digits) that identifies the particular issuer and additional digits (e.g. 10 digits) that identify a consumer account at that issuer. The first item on page 2 requests a business identification number (BIN) for the issuer 104 . The next section on the program information form asks for the beginning consumer account number and an ending consumer account number, thereby defining the range of payment account numbers that can be issued for this prepaid program.
In the central part of page 2, the issuer is requested to identify the type of portable payment device that will be issued to users of this account. The exemplary form provides a selection of four different types of cards: a conventional Visa® branded card; a card with a private label for the particular issuer or program sponsor, such as a specific employer for a benefits card for its employees; a virtual card, meaning that an actual card is not issued but the number may be used for e-commerce transactions; or a card for the PLUS® automatic teller machine network. It should be understood that not only can other types of cards be provided on the selection list, but also other types of portable payment devices mentioned previously.
At the bottom of the second page, the issuer 104 is asked to identify the type of prepaid program from among those that are supported by the transaction handler 106 . The types of programs on the exemplary program information form in FIG. 5 include a BUXX program for teenagers to make purchases using a debit account, a consumer gift card, and a program for campus/student related disbursements by which college students can purchase items at food establishments, a bookstore, and other merchants on a college campus. Other programs listed are a conventional health savings account which under the laws of the United States allow an individual to make certain purchases of health related products and services with pre-income tax money, an incentive health/wellness account by which an employer encourages its employees to participate in certain healthy activities, and finally a transit/parking employee benefit account in which an employer deposits money to be used for transportation related expenses of its employees. Other types of prepaid programs that could be listed include a debit account, a stored value card, and a flexible spending account. Once all the appropriate information and selections on page 2 of the program information form have been made, the issuer then clicks on the NEXT button to advance to another page of the program information form. Additional pages than those illustrated can be provided for the entry of other data required by either the issuer 104 or the transaction handler 106 in order to establish a prepaid program. The information on the subsequent pages may vary depending upon selections made previously by the issuer, for example, additional information specifically related to the requirements for a campus/student disbursement cards may be different than that required for a health savings account.
If while filling out the program information form, the issuer 104 comes to a point at which the form must be completed at a later time, the issuer can stop the process by clicking on the EXIT button at the bottom of the form page displayed on the personal computer monitor. This action causes the process to branch from step 208 to step 212 at which the issuer is afforded the opportunity to save the partially completed form in a temporary storage section of the memory 118 of the computer system 116 at step 214 . This allows the issuer 104 to terminate the present access session and at a later point in time re-access the prepaid program function to complete filling out the program information form. Alternatively, the issuer can exit the process without saving the partially completed form.
To complete a stored program information form, the issuer accesses the prepaid program function at step 201 via the Internet website, as described previously. At step 202 , however, the issuer now selects “Access a Stored Information Form” on the main menu in FIG. 3 . This causes the process to branch the step 203 where the issuer enters the tracking number of that previously stored form submission. Alternatively, the transaction handler presents a list of previously uncompleted forms that the issuer stored on the computer system and the issuer then selects the desired one. The process then advances to step 207 where the stored form is displayed to the issuer and the data entry resumes.
After completing the program information form, the issuer 104 clicks on a SUBMIT button on the last page of that form to file the document as a request for the transaction handler to create a new prepaid program. At that time, the process depicted in the flow chart of FIG. 2 advances to step 209 at which the entries of the form are checked to determine whether they are correct. In doing so, the transaction handler applies specific rules related to the form completion that have been defined by either the transaction handler 106 or the issuer 104 . Certain of these rules are very obvious, for example, an entry in the field for the business identification number contains less than six digits or an alphabetic character, that entry is erroneous as it must contain six numerical digits. The data check also verifies that entry has been made in all of the required fields and that all the necessary item selections have been made. As each item is checked, if it is found to be incorrect, the program execution branches to step 210 where the process returns to the incorrect data item on the program information form in order that the issuer can enter a correct value. An incorrect value can be further indicated by a change in the type of cursor or highlighting the erroneous data field in a different color on the computer monitor. The program execution then waits at step 208 for the issuer to enter the correct data. Thus, obvious errors in the data entered on the program information form are corrected during the issuer's initial submission of the form.
Alternatively the data in one field can be checked immediately when the issuer advances to another field. In that case, the data checking takes place while the issuer 104 is accessing the prepaid program function on the computer system. Thus the program information form is initially checked and many errors rectified before the form is actually filed for review by the transaction handler 106 .
As a further alternative, the computer system 116 may check the data on the program information form off-line after the entire application has been submitted. An email then is sent to the submitter at the issuer 104 that identifies any errors requiring correction before the prepaid program application can be processed further. The issuer then responds by again accessing the computer system 116 and the prepaid program function via steps 201 - 203 to obtain the previously submitted program information form for correction.
When a properly completed form has been found at step 209 , the process advances to step 216 at which the issuer is afforded the opportunity to attach collateral information to the submission. Such collateral materials can include artwork for a custom portable payment device (e.g. a debit card), screen shots and other information for a website of the issuer 104 regarding the prepaid program, and printed materials describing the prepaid program that are to be distributed to consumers 102 . For example, the collateral materials may include instructions about limitations on the use of a prepaid program account, such as a health savings account, the use of which is limited by law to certain types of medical products and services. Collateral materials can also include other items that the transaction handler 106 must approve prior to establishing the prepaid program, such as use of a trademark of the transaction handler. A conventional procedure is employed by which the issuer gathers the related documents from its computer network and uploads copies of those documents into the computer system 116 at the transaction handler 106 where the documents are associated with the previously completed program information form.
At step 217 , the entries on the program information form and a list of attached collateral materials are displayed for final review by the issuer 104 .
Next the completed program information form and the collateral information, if any, are formally submitted as an application for a new prepaid program at step 218 . The transaction handler 106 responds by saving the application in a data file on the computer system 116 designated to receive those submissions. Then at step 222 , the transaction handler 106 sends the issuer a screen display confirming that the new prepaid program application has been successfully received and listing the specific items that were submitted. In addition, the transaction handler 106 sends a separate confirmation email message to the submitter at the email address that was entered on page 1 of the program information form, shown in FIG. 4 .
The items submitted as the prepaid program application are sent to a special mailbox within the transaction handler 106 at step 224 . Depositing a submission in that mailbox automatically notifies personnel at the transaction handler that another application has been received for further processing.
The new prepaid program application has two components, the program information form and the collateral materials, which may be reviewed by different departments within the transaction handler 106 . Thus at step 226 , the program information form is reviewed on-line via the computer system by the prepaid program administration to determine whether it is complete and complies with general program rules established by the transaction handler and any rules promulgated by the issuer that submitted the form. If the program information form complies with the respective rules for the requested type of prepaid program, the prepaid program administration establishes the prepaid program for the issuer. The prepaid program administration then files an approval indication at step 230 in the computer stored record for this application. In addition, the collateral information that was submitted with the application has to be approved by the program compliance management at step 228 . This operation determines whether the artwork for the portable program device is acceptable and whether the other materials to be used in conjunction with that program also are acceptable. For example, each time a health savings account is issued, the associated consumer must be presented with materials informing them of the procedures and restrictions for that account. Therefore, those instructional materials must be reviewed and approved by the transaction handler at step 228 . The on-line review of such collateral materials can occur simultaneously with the review of the program information form at step 228 or the collateral materials can be reviewed after the program information form has been found to be acceptable. After both the program information form and the collateral material have been approved or rejected at steps 226 and 228 , the issuer is informed of those determinations by an email sent to the submitter at step 230 . If everything is approved, the process for establishing a prepaid program is completed.
The submission of the program information data via an online form as described above enables each item of data to be automatically transferred into the appropriate prepaid program files in the transaction handler's computer system 116 . In contrast, the previous method in which a written form was mailed or faxed to the transaction handler 106 required that the individual items of information be manually entered into the computer system at the transaction handler which could introduce errors into that data. Thus the current system eliminates several potential places where errors may occur.
After filing an application for a prepaid program, the issuer 104 can access the computer system 116 of the transaction handler 106 to learn the status of that application. To do so at step 202 where the main menu in FIG. 3 is being displayed, the issuer selects the final menu item, causing the process to branch to step 205 at which the issuer is requested to enter the tracking number of the respective application. Then the process advances to step 206 where the computer system 116 accesses the file for that application and specifically reads the contents of a field therein that indicates the status. That status field is updated at various points during the application review process. For example, initially the status field merely indicates that the program information form and other submitted materials have been received by the transaction handler 106 . At different steps during the approval process as specific submitted items are approved or rejected, indications of those determinations are provided by changing the contents of the status field accordingly. Thus at step 206 , the present contents of the status field are used to formulate an application status message which is transmitted back through the internet to the issuer 104 .
The preferred embodiment of the present technique for establishing a prepaid program offers several advantages over the previous procedure. Included are limiting submission of a proposal for a prepaid program to only an issuer which has been assigned a user identifier and password to access the computer system at the transaction handler. The technique also detects many types of errors while the issuer is filling out the program information form online and allows the issuer to correct the errors before submitting the form for review. Because the application data are submitted electronically, it can be transferred directly into the data files for the prepaid program that is created thereby eliminating data conversion errors. The online technique also enables enhanced tracking of the submission for a new prepaid program.
The steps of the process described in connection with the implementations disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The various steps or acts in the process may be performed in the order shown, or may be performed in another order. Additionally, one or more process steps may be omitted or one or more steps may be added to the process.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A payment system includes transaction handler that processes transactions, each characterized by a consumer and a merchant engaging in a sales transaction involving a prepaid program having prepaid cards, such as a gift card, that an issuer provides to consumers. A method for establishing a prepaid program includes the issuer remotely accessing a computer system at the transaction handler. The computer system presenting the issuer with a program information form on which the issuer enters requested data. As each data item is entered, the computer system checks for errors, which are identified to and corrected by the issuer in real time. The issuer submits the data as a request to create a prepaid program, which the transaction handler reviews and responds by approving or rejecting creation of the prepaid program. The transaction handler electronically communicates approval or rejection of the prepaid program to the issuer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application No. 61/195,915, filed Oct. 14, 2008.
BACKGROUND OF THE INVENTION
This invention relates to a device and apparatus for supporting work or work surfaces and more particularly to such a device and apparatus for use at building construction sites. Building construction sights now typically use saw horses or other temporarily assembled supports for supporting work or work surfaces at the construction site. This is often inconvenient and time consuming because saw horses may not be readily available or may be in use for other purposes. If construction workers are required to assemble temporary supports, their time is not being efficiently used in the construction process.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a device and apparatus for supporting work or a work surface at a building construction site.
Another object is to provide such a device and apparatus which can be quickly and easily positioned and held on vertical building studs.
A further object of the invention is the provision of such a device and apparatus which can be quickly positioned and easily assembled and disassembled at the construction site.
Still another object is to provide such a device which can be readily stored and transported.
Yet another object of the present invention is the provision of such an apparatus which uses the device of this invention and which apparatus can be assembled and disassembled at the construction site without the use of tools.
Another object is to provide such an apparatus which uses the device of this invention together with readily available lengths of lumber at the construction site.
Additional objects and advantages of the invention 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 invention. The objects and advantages are realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF SUMMARY OF THE INVENTION
To achieve these and other objects, the present invention provides a device for receiving and supporting a first length of material adjacent to a first member, the device comprising: a first flat element defining first and second opposed flat surfaces and first, second, third and fourth perimeter edges; a first right-angle bracket connected to the second surface; a second right-angle bracket connected to the second surface; the first and second brackets positioned in cooperating relationship with each other and with the flat element for removably supporting the device on the first member; a third right-angle bracket connected to the first surface; a fourth substantially right-angle bracket connected to the first surface; and the third and fourth brackets positioned in cooperating relationship with each other and with the flat element for removably receiving and supporting the first length of material adjacent to the first member.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate a preferred embodiment of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a perspective view of the receiving and supporting device of this invention;
FIG. 2 is a front elevation view of the device shown in FIG. 1 ;
FIG. 3 is a rear elevation view of the device;
FIG. 4 is a top plan view of the device;
FIG. 5 is a bottom plan view of the device;
FIG. 6 is a right side elevation view of the device;
FIG. 7 is a left side elevation view of the device;
FIG. 8 is a perspective view showing the device as it is initially positioned adjacent to a building stud;
FIG. 9 is a perspective view illustrating how the device is rotated from its position shown in FIG. 8 in the process of mounting the device onto a stud;
FIG. 10 is a different perspective view of the device as it is illustrated in FIG. 9 ;
FIG. 11 is a perspective view of the device mounted on a building stud and positioned ready for use;
FIG. 12 is a perspective view of the device mounted on a building stud and having a length of lumber supported by the device; and
FIG. 13 is a perspective view showing two of the devices mounted on neighboring studs with each device supporting a length of lumber to provide apparatus for supporting work or a work surface.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown a device 10 in accordance with the invention for receiving and supporting a first length of material 11 adjacent to a first member 13 .
Device 10 includes a first substantially flat element 20 defining first 22 and second 24 opposed substantially flat surfaces and first 26 , second 28 , third 30 and fourth 32 perimeter edges.
In accordance with the invention, device 10 further includes a first 34 substantially right-angle bracket connected to second surface 24 and a second 36 substantially right-angle bracket connected to second surface 24 .
The first 34 and second 36 brackets are positioned in cooperating relationship with each other and with flat element 20 for removably supporting device 10 on first member 13 .
Device 10 further includes a third 38 substantially right-angle bracket connected to first surface 22 and a fourth 40 substantially right-angle bracket connected to first surface 22 .
Third 38 and fourth 40 brackets are positioned in cooperating relationship with each other and with flat element 20 for removably receiving and supporting first length of material 11 adjacent to first member 13 .
First bracket 34 defines a first part 34 ′ substantially perpendicularly connected to second surface 24 and a second part 34 ″ substantially perpendicularly connected to first part 34 ′.
Second bracket 36 defines a third part 36 ′ substantially perpendicularly connected to second surface 24 and a fourth part 36 ″ substantially perpendicularly connected to third part 36 ′.
Second 34 ″ and fourth 36 ″ parts extend inwardly of device 10 with respect to second 28 and fourth 32 edges, respectively.
Third bracket 38 defines a fifth part 38 ′ substantially perpendicularly connected to first surface 22 and a sixth part 38 ″ substantially perpendicularly connected to fifth part 38 ′.
Fourth bracket 40 defines a seventh part 40 ′ substantially perpendicularly connected to first surface 22 and an eighth part 40 ″ substantially perpendicularly connected to seventh part 40 ′.
Sixth part 38 ″ extends inwardly of device 10 with respect to third edge 30 and eighth part 40 ″ extends in a direction away from first edge 26 and toward third edge 30 .
First member 13 is a substantially vertically oriented structural wall stud and first 34 and second 36 brackets are sized and positioned on flat element 20 for removably receiving stud 13 between second part 34 ″ and flat element 20 and between fourth part 36 ″ and flat element 20 , respectively, when device 10 is positioned on stud 13 .
First part 34 ′ and third part 36 ′ are positioned on flat element 20 to simultaneously engage stud 13 when device 10 is positioned on the stud.
Third 38 and fourth 40 brackets are positioned with respect to each other on flat element 20 to cooperatively receive and support first length of material 11 when the length of material is positioned between third 38 and fourth 40 brackets.
First length of material 11 is a length of lumber of predetermined dimensions, such as a two by four.
First bracket 34 is connected in adjacent relationship with second 28 and third 30 edges and second bracket 36 is connected in adjacent relationship with first 26 and fourth 32 edges.
Third bracket 38 is connected in adjacent relationship with second 28 and third 30 edges.
Fourth bracket 40 is connected in adjacent relationship with fourth edge 32 and seventh part 40 ′ is connected to flat element 20 substantially midway between first 26 and third 30 edges.
Each of first 34 ′, second 34 ″, third 36 ′, fourth 36 ″, fifth 38 ′, sixth 38 ″, seventh 40 ′ and eighth 40 ″ parts are flat.
Device 10 is preferably comprised of metal and each of the brackets is preferably welded to flat element 20 .
Fifth 38 ′ and seventh 40 ′ parts extend equal distances from first surface 22 and first 34 ′ and third 36 ′ parts extend equal distances from second surface 24 .
Work supporting apparatus as shown in FIG. 13 includes two of devices 10 positioned on neighboring ones of first members or studs 13 . As shown in FIG. 13 , each of devices 10 supports one length of material 11 for receiving and supporting work or work surface 42 on lengths of material 11 .
In operation and use, devices 10 are positioned onto studs 13 by positioning and moving devices 10 in a sequence shown in FIGS. 8-11 . No tools are required to accomplish this. Lengths of material or lumber 11 are then positioned in supporting relationship with respect to each device 10 as shown in FIGS. 12 and 13 .
Two or more of devices 10 can be positioned onto neighboring ones of studs 13 , as shown in FIG. 13 , and work or work surfaces 42 are positioned onto lengths of material 11 . Work 42 can then be cut or otherwise manipulated while being supported by lengths of material 11 .
Elements 42 illustrated in FIG. 13 may also be a flat sheet or sheets of plywood or other flat material if it is desired to create a temporary desk or table at the construction site.
The invention in its broader aspects is not limited to the specific details shown and described, and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.
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A device for use at construction sites, the device having a plurality of brackets for quickly and easily mounting the device on building studs and for supporting a length of material, such as a two by four, and wherein two or more of the devices can be mounted on neighboring building studs to create a work or work surface supporting apparatus.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to machine tools furnished with: a bed; a table on which a workpiece is carried and which is disposed on the bed; a main spindle for retaining a tool, and provided, with its axis disposed perpendicularly, to rotate freely centered on the axis; and a feed mechanism for shifting the table and the main spindle relatively to each other along three orthogonal axes.
2. Description of the Related Art
Such machine tools known to date include the example disclosed in Japanese Unexamined Patent App. Pub. 2001-87964. This machine tool primarily is made up of: a bed; a column arranged on the bed; a saddle that is supported on the front of the column and is shiftable horizontally (along the X-axis); a spindle head that is supported on the saddle and is shiftable vertically (along the Z-axis); a main spindle for retaining a tool and being supported by the spindle head so that the axis of the main spindle is perpendicular and the main spindle is rotatable about the main spindle axis; and a table on which a workpiece is carried, the table being arranged on the upper face of the bed and provided below the main spindle, provided to be shiftable along an axis (the Y-axis) that is orthogonal in the horizontal plane to the course along which the saddle shifts.
This machine tool also has a rotational drive mechanism for rotating the main spindle on the main spindle axis, an X-axis guide mechanism for guiding movement along the X-axis of the saddle, a Z-axis guide mechanism for guiding movement along the Z-axis of the spindle head, a Y-axis guide mechanism for guiding movement along the Y-axis of the table, an X-axis feed mechanism for moving the saddle on the X-axis, a Z-axis feed mechanism for moving the spindle head on the Z-axis, a Y-axis feed mechanism for moving the table on the Y-axis, a machine tool cover that is attached to the bed and surrounds the machine tool, an X-axis cover disposed in front of the cover, a Z-axis cover disposed in front of the cover, a Y-axis cover disposed above the bed, and a guide cover disposed above the bed on both sides of the table on the X-axis.
The X-axis guide mechanism comprises a first X-axis guide surface formed along the X-axis in front of the column, and a second X-axis guide surface formed behind the saddle so that the second X-axis guide surface connects with the first X-axis guide surface. The Z-axis guide mechanism comprises a first Z-axis guide surface formed along the Z-axis in front of the saddle, and a second Z-axis guide surface formed behind the spindle head so that the second Z-axis guide surface connects with the first Z-axis guide surface. The Y-axis guide mechanism comprises a first Y-axis guide surface formed along the Y-axis above the bed, and a second Y-axis guide surface formed below the table so that the second Y-axis guide surface connects with the first Y-axis guide surface.
The X-axis feed mechanism comprises an X-axis drive motor disposed to the column, an X-axis ball screw disposed along the X-axis in front of the column and axially rotated by the X-axis drive motor, and an X-axis nut that is affixed to the back of the saddle and screws onto the X-axis ball screw. The Z-axis feed mechanism comprises a Z-axis drive motor disposed to the saddle, a Z-axis ball screw disposed along the Z-axis in front of the saddle and axially rotated by the Z-axis drive motor, and a Z-axis nut that is affixed to the back of the spindle head and screws onto the Z-axis ball screw. The Y-axis feed mechanism comprises a Y-axis drive motor disposed to the bed, a Y-axis ball screw disposed along the Y-axis above the bed and axially rotated by the Y-axis drive motor, and a Y-axis nut that is affixed to the bottom of the table and screws onto the Y-axis ball screw.
The X-axis cover is a telescopic cover disposed in front of the column to allow movement of the saddle along the X-axis with both side portions and the top portion of the cover connected to the inside of the machine tool cover. The Z-axis cover is a roll-up cover disposed in front of the saddle covering the Z-axis guide mechanism and the Z-axis feed mechanism to allow movement of the spindle head along the Z-axis. The Y-axis is a telescopic cover disposed above the bed covering the Y-axis guide mechanism and Y-axis feed mechanism to allow movement of the table along the Y-axis, and is rendered so that the top of the Y-axis cover declines to both sides from the middle portion of the Y-axis cover on the X-axis. The covers prevent chips, swarf and other cutting waste and cutting fluid from flying outside the machine tool and from entering the X-axis guide mechanism and X-axis feed mechanism, the Z-axis guide mechanism and Z-axis feed mechanism, and the Y-axis guide mechanism and Y-axis feed mechanism.
The guide cover is disposed below the X-axis cover, the Z-axis cover, and the Y-axis cover, and guides waste and cutting fluid into a collection box located below drain holes appropriately formed in the bed along the X-axis on both sides of the table.
When the X-axis drive motor in this machine tool rotates the X-axis ball screw and the X-axis nut moves along the X-axis ball screw, the saddle moves along the X-axis guided by the first X-axis guide surface and the second X-axis guide surface. When the Z-axis drive motor rotates the Z-axis ball screw and the Z-axis nut moves along the Z-axis ball screw, the spindle head moves along the Z-axis guided by the first Z-axis guide surface and the second Z-axis guide surface. When the Y-axis drive motor rotates the Y-axis ball screw and the Y-axis nut moves along the Y-axis ball screw, the table moves along the Y-axis guided by the first Y-axis guide surface and the second Y-axis guide surface. The rotational drive mechanism drives the main spindle rotationally on the main spindle axis. The workpiece held on the table is thus processed by the tool held in the main spindle as the saddle, spindle head, and table move on their respective axes while the main spindle rotates on the main spindle axis.
Waste produced by machining the workpiece and cutting fluid supplied appropriately to the point of contact between the tool and the workpiece during processing are also prevented from entering the X-axis guide mechanism and X-axis feed mechanism, the Z-axis guide mechanism and Z-axis feed mechanism, and the Y-axis guide mechanism and Y-axis feed mechanism by the X-axis cover, the Z-axis cover, and the Y-axis cover, respectively, and from flying outside the machine tool by the machine tool cover.
In addition, waste and cutting fluid also fall down along the inside surface of the machine tool cover, the X-axis cover, and the Z-axis cover, and are guided downward to both sides along the X-axis by the inclined surface of the top of the Y-axis cover. The waste and cutting fluid then fall onto the top of the guide cover whereby they are guided towards the collection box and exit.
With this conventional machine tool, the Y-axis guide mechanism that guides table movement and the Y-axis feed mechanism that moves the table are located below the top of the table, and waste and cutting fluid always flow over the top of the Y-axis cover. Waste and cutting fluid can therefore enter the Y-axis guide mechanism and Y-axis feed mechanism more easily than the X-axis guide mechanism and X-axis feed mechanism or the Z-axis guide mechanism and Z-axis feed mechanism. As a result, the Y-axis cover requires frequent maintenance, or requires using a complicated and costly construction.
Another problem with the conventional technology is that the heavy saddle is supported at the front of the column and the similarly heavy spindle head is supported at the front of the saddle with the saddle and spindle head protruding to the front of the machine tool. This results in deflection or deformation of the column or saddle and thus prevents high precision machining.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to solving these problems, and an object of the invention is to provide a machine tool that affords easy maintenance, reduces manufacturing cost, and enables high precision processing.
To achieve this object, a machine tool according to a preferred aspect of the invention comprises: a bed comprising a rectangular base, two sidewalls rising vertically from opposing left and right sides of the base across an interval between the sidewalls, and a rear sidewall disposed at the back vertically to the base between the right and left sidewalls; a table disposed to the bed in a space surrounded by the three sidewalls of the bed; a first saddle having a rectangular frame shape with both lengthwise end parts supported by a top portion of the left and right sidewalls of the bed, and disposed freely movably back and forth in a horizontal plane; a second saddle disposed freely movably side-to-side in a horizontal plane inside the frame of the first saddle, and comprising a vertical through-hole; a spindle head disposed freely movably vertically inside the through-hole of the second saddle; a main spindle disposed above the table with the main spindle axis vertical and the main spindle supported by the spindle head freely rotatably on the main spindle axis; a first guide mechanism for guiding the first saddle back and forth; a second guide mechanism for guiding the second saddle side-to-side; a third guide mechanism for guiding vertical movement of the spindle head; a first feed mechanism for moving the first saddle back and forth; a second feed mechanism for moving the second saddle side-to-side; a third feed mechanism for moving the spindle head vertically; and a first rotation drive mechanism for rotating the main spindle on the main spindle axis.
With the machine tool according to this aspect of the invention the first saddle is guided by the first guide mechanism and moved back and forth by the first feed mechanism, the second saddle is guided by the second guide mechanism and moved side-to-side by the second feed mechanism, the spindle head is guided by the third guide mechanism and moved vertically by the third feed mechanism, the main spindle is driven rotationally on its axis by the first rotation drive mechanism, and the work held on the table is thus machined by the tool held by the main spindle.
In a machine tool according to this aspect of the invention the table is disposed inside the space enclosed by the three sidewalls of the bed, both ends of the long sides of the first saddle are supported and move freely back and forth on top of the right and left sidewalls of the bed, the second saddle is disposed movably side-to-side (right and left) inside the frame of the first saddle, and the spindle head is disposed to move vertically inside the through-hole in the second saddle. As a result, the first saddle, the second saddle, and the spindle head can also be disposed above the top of the table.
A machine tool according to this invention therefore makes it more difficult for waste and cutting fluid to enter the first feed mechanism and first guide mechanism, the second feed mechanism and second guide mechanism, and the third feed mechanism and third guide mechanism when compared with a prior art machine tool in which the feed mechanism for moving the table and the guide mechanism for guiding table movement are disposed below the top of the table. The manufacturing cost and construction of the cover that prevents waste and cutting fluid from entering the slide and guide mechanisms can thus be reduced, and cover maintenance can be simplified.
Furthermore, the first saddle is rendered with a rectangular frame shape, the second saddle is disposed inside the frame of the first saddle, and the spindle head is disposed inside a through-hole formed vertically through the second saddle. Unlike the prior art machine tool, the saddle therefore does not project from the front and a support structure for the spindle head is not needed. Deflection and other deformation of the bed, first saddle, and second saddle are thus prevented, and work can be machined with high precision.
Furthermore, by rendering a recess at the front outside surface between the ends of the long sides of the first saddle, the front outside surface of the first saddle can be prevented from striking a worker working at the front of the bed when the first saddle moves to the front side of the bed.
In another aspect of the invention the table is supported by the rear sidewall of the bed, can rotate freely on an axis of rotation perpendicular to the top surface of the table, and can swivel freely on a swivel axis parallel to the direction of first saddle movement. In addition, the machine tool further comprises: a second rotation drive mechanism for rotating the table on the axis of rotation and indexing the table to a specific rotational angle position; and a swivel drive mechanism for swiveling the table on the swivel axis and indexing the table to a specific swivel angle position.
The table can be rotated on the axis of rotation and indexed to a specific rotational angle position by means of the second rotation drive mechanism, and can be rotated on the swivel axis and indexed to a specific swivel angle position by means of the swivel drive mechanism, to index the work on the table to an appropriate position. The work therefore needs to be mounted on the table only once in order to complete a processing sequence including machining the outside of the work, thus improving efficiency and machining precision.
In a machine tool according to another aspect of the invention the bed comprises a tool changing opening passing from the outside to the inside through any one of the right, left, and rear sidewalls, and the machine tool further comprises a tool changing device for carrying tools in and out through the tool changing opening, and replacing a tool held in the main spindle with a new tool.
Tools can thus be changed efficiently by means of the tool changing device replacing the tool held by the main spindle with a new tool. Furthermore, because the desired new tool can be delivered through the tool changing opening rendered in any one of the sidewalls of the bed, and the replaced tool that was held by the main spindle can be removed through the tool changing opening, the tool changing device does not interfere with the performance of a worker working at the front of the bed.
In a machine tool according to another aspect of the invention the bed comprises a pallet changing opening passing from the outside to the inside through any one of the right, left, and rear sidewalls, and the machine tool further comprises a pallet changing device for carrying pallets in and out through the pallet changing opening, and replacing a pallet holding processed work on the table with a new pallet holding unprocessed work.
Pallets can thus be changed efficiently by means of the pallet changing device replacing the pallet holding processed work on the table with a new pallet holding unprocessed work. Furthermore, because the new pallet can be delivered through the pallet changing opening rendered in any one of the sidewalls of the bed, and the replaced pallet that was held on the table can be removed through the pallet changing opening, the pallet changing device does not interfere with the performance of a worker working at the front of the bed.
In a machine tool according to another aspect of the invention the bed comprises a pallet changing opening passing from the outside to the inside through any two of the right, left, and rear sidewalls, and the machine tool further comprises a pallet changing device for carrying pallets in from one pallet changing opening and out through the other pallet changing opening, and replacing a pallet holding processed work on the table with a new pallet holding unprocessed work.
This arrangement enables delivering the new pallet through one of the two pallet changing openings rendered in any two of the sidewalls of the bed, and removing the replaced pallet fixed to the table from the other pallet changing opening. As a result, pallets can be changed efficiently by means of the pallet changing device and the pallet changing device does not interfere with the performance of a worker working at the front of the bed.
A machine tool according to another aspect of the invention also has a discharge means disposed below the table for discharging fluid toward the table, and a fluid supply means for supplying and discharging the fluid from the discharge means. The swivel drive mechanism can swivel the table in at least one table swiveling direction between a first swivel angle position where the top of the table is horizontal and a second swivel angle position where the table top is swiveled 90 degrees or more from the first swivel angle position, and the discharge means discharges fluid supplied from the fluid supply means toward the table swiveled to the second swivel angle position by the swivel drive mechanism.
When processing the work is finished, the swivel drive mechanism swivels the table to the second swivel angle position rotated 90 degrees or more from the first swivel angle position, and fluid is then supplied by the fluid supply means and discharged from the discharge means.
The direction in which the fluid is discharged from the discharge means is toward the table after the table has been swiveled to the second swivel angle position by the swivel drive means, and waste left on the table or on the work held on the table is removed by the fluid discharged from the discharge means. This causes the waste to fall so that it can be efficiently removed. Production costs can also be reduced because a special device for removing waste accumulated on or adhering to the work is not needed.
Alternatively, the discharge means can be rendered to discharge the fluid supplied from the fluid supply means toward the table after the table is swiveled by the swivel drive mechanism to a swivel angle position of 90 degrees or more from the first swivel angle position, and the fluid supply means can be rendered to supply the fluid to the discharge means while the table is being swiveled by the swivel drive mechanism from a swivel angle position of 90 degrees or more toward the second swivel angle position.
In this aspect of the invention the fluid is discharged from the discharge means while the table is swiveling and the table swivels through the streams of discharged fluid. Swiveling the table and removing waste by discharging fluid thus proceed in parallel, and the waste can be remove in less time and more efficiently.
In another aspect of the invention the bed has a waste discharge opening of which one end opens to the top of the base and the other end opens to the outside of the bed, and the machine tool further comprises a waste recovery means disposed inside the waste discharge opening for recovering waste falling from the open portion in the top of the base of the bed.
Waste can thus be efficiently discharged from the one end of the waste discharge opening rendered below and around the table in the top of the base of the bed, and can be recovered into the waste recovery means.
A machine tool according to the present invention thus renders the first saddle, second saddle, and spindle head movable in respective specific slide directions at a position above the top of the table, thus making it difficult for waste and cutting fluid to enter the first feed mechanism and first guide mechanism, the second feed mechanism and second guide mechanism, and the third feed mechanism and third guide mechanism. The construction and manufacturing cost of covers used to prevent such unwanted penetration of waste and cutting fluid can therefore be reduced and cover maintenance can be simplified.
Furthermore, because the second saddle is rendered inside the frame of the first saddle and the spindle head is disposed in a through-hole in the second saddle, the first saddle and second saddle are more resistant to deflection and other deformation, thus affording high precision machining.
From the following detailed description in conjunction with the accompanying drawings, the foregoing and other objects, features, aspects and advantages of the present invention will become readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an oblique schematic view of a machine tool according to a preferred embodiment of the invention.
FIG. 2 is an oblique schematic view of a machine tool according to a preferred embodiment of the invention.
FIG. 3 is an oblique schematic view showing the machine tool, a tool changing device, and a pallet changing device according to a preferred embodiment of the invention.
FIG. 4 is an oblique schematic view showing the machine tool, a tool changing device, and a pallet changing device according to a preferred embodiment of the invention.
FIG. 5 is a front view showing a part of a machine tool according to a preferred embodiment of the invention.
FIG. 6 is a section view through line A-A in FIG. 5 .
FIG. 7 is a plan view showing a part of the top cover in a preferred embodiment of the invention.
FIG. 8 is a plan view showing a part of the top cover in a preferred embodiment of the invention.
FIG. 9 is a section view through line B-B in FIG. 7 .
FIG. 10 is a section view through line C-C in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the invention is described below with reference to the accompanying figures wherein FIG. 1 and FIG. 2 are oblique schematic views of a machine tool according to a preferred embodiment of the invention, and FIG. 3 and FIG. 4 are oblique schematic views showing the machine tool, a tool changing device, and a pallet changing device according to this preferred embodiment of the invention. FIG. 5 is a front view showing a part of a machine tool according to this preferred embodiment of the invention, and FIG. 6 is a section view through line A-A in FIG. 5 . FIG. 7 and FIG. 8 are plan views showing a part of the top cover in this preferred embodiment of the invention, FIG. 9 is a section view through line B-B in FIG. 7 , and FIG. 10 is a section view through line C-C in FIG. 8 .
As shown in FIG. 1 to FIG. 6 , a machine tool 1 according to this embodiment of the invention has a machine tool unit 10 of a type known as a vertical machining center, a tool changing device 40 , pallet changing device 45 , and a waste recovery device 50 attached to the machine tool unit 10 , and a cover 60 covering at least the machine tool unit 10 , tool changing device 40 , and pallet changing device 45 .
The machine tool unit 10 comprises a bed 11 , a first saddle 16 that is disposed to the bed 11 and moves freely in a horizontal plane in the front-rear direction (along the Y-axis), a second saddle 17 that is disposed to the first saddle 16 and moves freely in a horizontal plane side to side (along the X-axis), a spindle head 18 that is disposed to the second saddle 17 and moves freely vertically (along the Z-axis), a main spindle 19 that holds a tool T and is supported by the spindle head 18 to rotate freely on the main spindle axis, and a table 20 on which a pallet P is mounted. Work W is fixed on top of the pallet P. The table 20 is disposed to the bed 11 and can swivel freely on an axis of rotation (B-axis) parallel to the Y-axis and rotate freely an axis of rotation (C axis) perpendicular to the top surface of the pallet P.
The machine tool unit 10 also comprises a Y-axis guide mechanism 21 for guiding movement of the first saddle 16 along the Y-axis, a X-axis guide mechanism 22 for guiding movement of the second saddle 17 along the X-axis, a Z-axis guide mechanism (not shown in the figures) for guiding movement of the spindle head 18 along the Z-axis, a Y-axis feed mechanism 24 for moving the first saddle 16 along the Y-axis, an X-axis feed mechanism 25 for moving the second saddle 17 along the X-axis, a Z-axis feed mechanism 26 for moving the spindle head 18 along the Z-axis, a main spindle rotational drive mechanism (not shown in the figures) for rotating the main spindle 19 on its axis, a first table rotation drive mechanism (not shown in the figures) for swiveling the table 20 on the B-axis for indexing to a specific rotational angle position, and a second table rotation drive mechanism (not shown in the figures) for rotating the table 20 on the C axis for indexing to a specific rotational angle position.
The bed 11 comprises with a rectangular base when seen in plan view, left and right sidewalls 13 and 14 (left sidewall 13 on the front left side and right sidewall 14 on the front right side) disposed vertically on both sides of the base 12 across an interval therebetween on the X-axis, and a sidewall 15 (rear sidewall) disposed vertically to the base 12 at the back between the right and left sidewalls 13 and 14 .
The base 12 has a waste removal hole 12 a of which one end opens to the top center portion of the base 12 and the other end opens to the back outside surface of the base 12 . The top of the base 12 and the base portion of the left sidewall 13 and the base portion of the right sidewall 14 decline into the opening to the waste removal hole 12 a.
A tool changing opening 13 a is formed through from the outside to the inside of the left sidewall 13 so that a tool T can be delivered into and removed from the inside of the machine tool unit 10 (the space enclosed by sidewalls 13 , 14 , 15 ) when the tool changing device 40 changes the tool T. A pallet changing opening 14 a is formed through from the outside to the inside of the right sidewall 14 so that a pallet P can be delivered into and removed from the inside of the machine tool unit 10 (the space enclosed by sidewalls 13 , 14 , 15 ) when the pallet changing device 45 changes the pallet P.
The table 20 comprises a pallet mounting unit 20 a on which a pallet P is mounted, and a support unit 20 b which is supported on the inside of the rear sidewall 15 of the bed 11 to swivel freely on the B-axis and supports the pallet mounting unit 20 a to rotate freely on the C axis. The table 20 is located in the space enclosed by the sidewalls 13 , 14 , 15 so that the pallet P mounted on the pallet mounting unit 20 a is substantially positioned above the waste removal hole 12 a , and there is a constant gap between the bottom of the support unit 20 b and the top of the base 12 .
The pallet mounting unit 20 a is rotated on the C axis by the second table rotation drive mechanism (not shown in the figures) and indexed to a specific rotational angle position, and the support unit 20 b is swiveled on the B-axis by the first table rotation drive mechanism (not shown in the figures) and indexed to a specific rotational angle position. The work W on the pallet P can thus be indexed to a desired angular position by rotating the support unit 20 b on the B-axis to swivel the pallet P on the B-axis, and by rotating the pallet P with the pallet mounting unit 20 a on the C axis.
A pallet P on the pallet mounting unit 20 a can be swiveled both to the right and to the left on the B-axis by the first table rotation drive mechanism (not shown in the figures) to any position on the B-axis between a position where the top of the pallet P is horizontal and facing up (with the pallet P at a swivel angle of 0 degrees) to a position where the top of the pallet P is horizontal and facing down (with the pallet P at a swivel angle of 180 degrees).
The first saddle 16 has a rectangular frame shape with the transverse side parallel to the X-axis and the longitudinal side parallel to the Y-axis. The end portions of the long transverse sides are supported to move freely along the Y-axis on the top of the left sidewall 13 and right sidewall 14 of the bed 11 . A recess 16 a is formed in the front outside surface between both ends of the long side of the first saddle 16 . As shown in FIG. 6 , when the first saddle 16 moves toward the front of the bed 11 , the recess 16 a prevents the front outside surface of the first saddle 16 from striking a worker S working at the front side of the bed 11 .
The second saddle 17 comprises a shoulder 17 a extending to each side in the Y-axis direction, and a through-hole 17 b passing vertically through the second saddle 17 . The second saddle 17 is disposed within the frame of the first saddle 16 with the shoulders 17 a supported by the top of the transverse portions of the first saddle 16 so that the second saddle 17 can move freely on the X-axis.
The spindle head 18 is supported to move freely on the Z-axis inside the through-hole 17 b in the second saddle 17 . The main spindle 19 is disposed above the table 20 with the main spindle axis parallel to the Z-axis and the main spindle 19 freely rotatably supported by the bottom portion of the spindle head 18 .
The Y-axis guide mechanism 21 comprises guide rails 21 a aligned with the Y-axis on the top of the left sidewall 13 and right sidewall 14 of the bed 11 , and sliders 21 b that are affixed to the bottom of both long end parts of the first saddle 16 and engage and move freely on the guide rails 21 a.
The Y-axis feed mechanism 24 comprises drive motors 24 a disposed on the top of left sidewall 13 and right sidewall 14 of the bed 11 , ball screws 24 b , and nuts 24 c . The ball screws 24 b are disposed aligned with the Y-axis on the top of the left sidewall 13 and right sidewall 14 of the bed 11 , and are axially rotated by the corresponding drive motors 24 a . The nuts 24 c are affixed to the outside surfaces of the longitudinal portions of the first saddle 16 , and screw onto the matching ball screws 24 b.
When the drive motors 24 a of this Y-axis feed mechanism 24 are driven and the ball screws 24 b thus turn axially, the nuts 24 c move along the ball screws 24 b and the first saddle 16 thus moves on the Y-axis guided by the guide rails 21 a and sliders 21 b of the Y-axis guide mechanism 21 .
The X-axis guide mechanism 22 comprises guide rails 22 a disposed aligned with the X-axis on the top of the transverse side portions of the first saddle 16 , and sliders 22 b that are affixed to the bottoms of the shoulders 17 a of the second saddle 17 and engage and move freely on the guide rails 22 a.
The X-axis feed mechanism 25 comprises a drive motor 25 a disposed to one longitudinal side portion of the of the first saddle 16 , a ball screw 25 b that is disposed on the X-axis inside the frame of the first saddle 16 and is axially rotated by the drive motor 25 a , and a nut (not shown in the figures) that is affixed to the second saddle 17 and screws onto the ball screw 25 b.
When the drive motor 25 a of this X-axis feed mechanism 25 is driven and the ball screw 25 b turns axially, the nut moves along the ball screw 25 b and the second saddle 17 thus moves along the X-axis guided by the guide rails 22 a and sliders 22 b of the X-axis guide mechanism 22 .
The Z-axis guide mechanism (not shown in the figures) comprises guide rails (not shown in the figures) aligned with the Z-axis on the inside of both X-axis sides of the through-hole 17 b of the second saddle 17 , and sliders (not shown in the figures) that are affixed to the outside of both X-axis sides of the spindle head 18 and engage and move freely on these guide rails (not shown in the figures).
The Z-axis feed mechanism 26 comprises drive motors 26 a disposed on the top of both X-axis sides of the second saddle 17 , ball screws (not shown in the figures) that are disposed aligned with the Z-axis on the inside of both X-axis sides of the second saddle 17 and are axially rotated by the drive motors 26 a , and nuts (not shown in the figures) that are affixed to the outside of both X-axis sides of the spindle head 18 and screw onto the ball screws (not shown in the figures).
When the drive motors 26 a of this Z-axis feed mechanism 26 are driven and the ball screws (not shown in the figures) turn axially, the nuts (not shown in the figures) move along the ball screws so that the spindle head 18 moves on the Z-axis guided by the guide rails (not shown in the figures) and sliders (not shown in the figures) of the Z-axis guide mechanism (not shown in the figures).
The tool changing device 40 comprises a tool magazine 41 , a tool changing arm 42 , and a drive mechanism unit 43 . The tool magazine 41 is supported on the outside of the left sidewall 13 of the bed 11 , and has a plurality of holding units 41 a each holding a tool T. The tool changing arm 42 swivels horizontally, grips the tool T held in the main spindle 19 on one end, and is inserted from the tool magazine 41 through the tool changing opening 13 a in the left sidewall 13 to the inside of the machine tool unit 10 to grip the (next) tool T positioned at a predetermined position with the other end. The drive mechanism unit 43 is supported on the inside surface of the left sidewall 13 and supports the tool changing arm 42 , and causes the tool changing arm 42 to rotate horizontally and move vertically.
The tool changing device 40 replaces the tool T on the main spindle 19 with the next tool T set to a predetermined position (indicated by the imaginary line in FIG. 3 and FIG. 4 ) as a result of the horizontal rotation and vertical movement of the tool changing arm 42 driven by the drive mechanism unit 43 , and introduces and removes the tools T through the tool changing opening 13 a in the left sidewall 13 .
The pallet changing device 45 has pallet moving table 46 and a pallet moving mechanism 47 . The pallet moving table 46 has a plurality of pallet tables 46 a on top of which the pallets P are placed, and rotates the pallet tables 46 a on a vertical axis of rotation in the direction of the arrows shown in FIG. 3 and FIG. 4 . The pallet moving mechanism 47 is located between the machine tool unit 10 and the pallet moving table 46 , and moves a pallet P between the pallet table 46 a rotated to a predetermined position by the pallet moving table 46 and the table 20 inside the machine tool unit 10 .
The pallet moving mechanism 47 has a conveyance member 47 a that can move to and away from the table 20 through the pallet changing opening 14 a in the right sidewall 14 of the bed 11 . When moving a pallet P, the conveyance member 47 a moves to the table 20 to place or remove a pallet P on the table 20 through the pallet changing opening 14 a , and thus replaces the pallet P carrying the processed work W on the table 20 with a new pallet P carrying unprocessed work W.
Loading and unloading work W on a pallet P is done by a worker, for example, after the pallet moving table 46 has rotated the pallet table 46 a (pallet P) to a predetermined rotational position where the processed work W is removed from the pallet P and an unprocessed work W is mounted on the pallet P.
The waste recovery device 50 comprises a discharge mechanism 51 , a storage tank 54 , a collection box 55 , a nozzles 56 , and a supply pump (not shown in the figures).
The discharge mechanism 51 conveys cutting waste resulting from processing the work W in a specific transportation direction and removes the waste from the machine tool unit 10 . The storage tank 54 is disposed below the discharge mechanism 51 on the upstream side in the waste transportation direction, and stores the cutting fluid. The collection box 55 is disposed below the discharge mechanism 51 at the downstream end of the transportation direction. A plurality of nozzles 56 are disposed inside the waste removal hole 12 a at the top of the opening in the base 12 , and on the rear sidewall 15 at the top of the waste removal hole 12 a in the base 12 . The supply pump (not shown in the figures) supplies cutting fluid from the storage tank 54 to the plural nozzles 56 for discharge to the work W.
The discharge mechanism 51 comprises a conveyor belt 52 composed of a plurality of plates connected in an endless loop for carrying cutting waste to the collection box 55 , and a support unit 53 that houses and enables the conveyor belt 52 to move freely in a loop. The support unit 53 has a horizontal portion 53 a disposed inside the waste removal hole 12 a , and an incline portion 53 c disposed outside the machine tool 1 . The discharge mechanism 51 also has a drive motor (not shown in the figures) that causes the conveyor belt 52 to move in the direction of the arrows shown in FIG. 6 .
The horizontal portion 53 a of the support unit 53 is open on the top and bottom. Waste and cutting fluid drop from this open portion 53 b onto the conveyor belt 52 , and cutting fluid that drops onto the conveyor belt 52 flows down through this open portion 53 b into the storage tank 54 as further described below. The bottom of the downstream end part of the incline portion 53 c of the support unit 53 is open, and waste conveyed by the conveyor belt 52 drops through this opening (not shown in the figures) into the collection box 55 below.
The storage tank 54 is located below the horizontal portion 53 a of the support unit 53 and collects the cutting fluid that drops from the conveyor belt 52 .
The nozzles 56 are arranged to discharge cutting fluid supplied by the supply pump (not shown in the figures) through supply tubes not shown upward toward the pallet P on the table 20 , which has been swiveled 180 degrees on the B-axis to the upside down position by the first table rotation drive mechanism (not shown in the figures).
With this waste recovery device 50 , waste and cutting fluid are guided into the waste removal hole 12 a by the inclined top of the base 12 , the inclined based portions where the left sidewall 13 and right sidewall 14 meet the base 12 , and covers not shown disposed appropriately in the space enclosed by the sidewalls 13 , 14 , 15 , and drop from this waste removal hole 12 a onto the conveyor belt 52 , which is driven in a circle by a drive motor (not shown in the figures). The cutting waste is then conveyed outside the machining center by the conveyor belt 52 , falls into the collection box 55 located below the downstream end of the conveyor belt 52 , and is recovered. The cutting fluid drops from the conveyor belt 52 and is collected in the storage tank 54 .
As shown in FIG. 5 and FIG. 6 , the support unit 20 b of the table 20 is swiveled 180 degrees on the B-axis by the first table rotation drive mechanism (not shown in the figures) so that the support unit 20 b and the work W on the pallet P attached to the pallet mounting unit 20 a are upside down. Cutting fluid is then supplied from the supply pump (not shown in the figures) and discharged from the nozzles 56 to remove any cutting waste left on the support unit 20 b , the pallet mounting unit 20 a , the pallet P, and the work W, for example. The waste thus removed drops onto the conveyor belt 52 from the waste removal hole 12 a , and is conveyed outside the machine tool unit 10 and recovered.
The cover 60 includes a first cover 61 covering the outside of the machine tool unit 10 and the tool changing device 40 ; a second cover 62 that is connected to the first cover 61 and covers the pallet changing device 45 ; a top cover 70 that is connected to the first cover 61 and covers the top of the opening enclosed by the sidewalls 13 , 14 , 15 of the bed 11 ; a telescopic third cover 63 that is rendered inside the frame of the first saddle 16 of the machine tool unit 10 to enable movement of the second saddle 17 on the X-axis; a tool changer door for closing the tool changing opening 13 a in the left sidewall 13 of the bed 11 ; and a pallet changer door (not shown in the figures) for closing the pallet changing opening 14 a in the right sidewall 14 of the bed 11 .
The tool changer door (not shown in the figures) can be opened as needed during the tool changing operation of the tool changing device 40 , and the pallet changer door (not shown in the figures) can be opened as needed during the pallet changing operation of the pallet changing device 45 .
The first cover 61 comprises a left door 61 a that opens by sliding to the left sidewall 13 of the bed 11 at the front of the machine tool unit 10 , and a right door 61 b that slides to the right sidewall 15 to open. The opened doors 61 a and 61 b are housed in pockets 61 c rendered in the front of the first cover 61 .
The second cover 62 comprises doors 62 a that slide to the right and left to open similarly to the first cover 61 . Work W can be placed on and removed from the pallets P on the pallet moving table 46 of the pallet changing device 45 through the opening afforded by these doors 62 a.
The top cover 70 comprises a guide rail 71 disposed on the front top portion of the first saddle 16 and aligned with the X-axis; a left moving member 72 and right moving member 73 having sliders 72 a and 73 a that engage and move freely on the guide rail 71 ; a first left top cover 74 and a first right top cover 75 disposed below the guide rail 71 ; a second left top cover 76 and a second right top cover 77 disposed above the first top covers 74 and 75 with the front and back end parts of the covers 76 and 77 connected to the top inside surface of the doors 61 a and 61 b of the first cover 61 and the moving members 72 and 73 ; and a left linkage member 78 and a right linkage member 79 disposed above the second top covers 76 and 77 with the end parts connected to the top inside of the doors 61 a and 61 b of the first cover 61 and the moving members 72 and 73 .
The first top covers 74 and 75 are telescopic covers that enable movement of the first saddle 16 on the Y-axis. The first left top cover 74 is installed with the bottom part attached to the top of the left sidewall 13 of the bed 11 inside of the guide rails 21 a of the Y-axis guide mechanism 21 , the back part below the guide rail 71 at the front left end part of the long side of the first saddle 16 , and the front part attached to the top inside part of the first cover 61 . The first right top cover 75 is installed with the bottom part attached to the top of the right sidewall 14 of the bed 11 inside of the guide rails 21 a of the Y-axis guide mechanism 21 , the back part below the guide rail 71 at the front right end part of the long side of the first saddle 16 , and the front part attached to the top inside part of the first cover 61 .
The first top covers 74 and 75 do not cover the Y-axis guide mechanism 21 and Y-axis feed mechanism 24 because the bottom part of the covers is disposed inside of the guide rails 21 a at the top of the sidewalls 13 and 14 of the bed 11 .
The second top covers 76 and 77 are bellows-like covers enabling movement of the first saddle 16 on the Y-axis. The front part of the second left top cover 76 is attached to the top inside part of the left door 61 a , and the back part is attached to the left moving member 72 . The front part of the second right top cover 77 is attached to the top inside part of the right door 61 b , and the back part is attached to the right moving member 73 .
The linkage members 78 and 79 comprise a pantograph mechanism enabling movement of the first saddle 16 on the Y-axis, and two linkage members are disposed to each of the second top covers 76 and 77 . The ends of the left linkage member 78 are affixed to the top inside part of the left door 61 a and the left moving member 72 , and the ends of the right linkage member 79 are affixed to the top inside part of the right door 61 b and right moving member 73 .
The first cover 61 , third cover 63 , top cover 70 , tool changer door (not shown in the figures), and pallet changer door (not shown in the figures) of the cover 60 , and the covers (not shown in the figures) appropriately disposed to the inside of the sidewalls 13 , 14 , 15 of the bed 11 , close the space (machining area) contained within the sidewalls 13 , 14 , 15 , and prevent waste and cutting fluid from flying outside.
When the doors 61 a and 61 b of the first cover 61 open and close as shown in FIG. 1 , FIG. 2 , FIG. 7 , and FIG. 8 , the second top covers 76 and 77 are guided by the guide rail 71 and sliders 72 a and 73 a and move on the X-axis together with the linkage members 78 and 79 and moving members 72 and 73 . As a result, opening and closing the doors 61 a and 61 b opens and closes the top part of the working area.
With the machine tool 1 according to this embodiment of the invention the first saddle 16 is guided by the Y-axis guide mechanism 21 and moved along the Y-axis by the Y-axis feed mechanism 24 , the second saddle 17 is guided by the X-axis guide mechanism 22 and moved along the X-axis by the X-axis feed mechanism 25 , the spindle head 18 is guided by the Z-axis guide mechanism (not shown in the figures) and moved along the Z-axis by the Z-axis feed mechanism 26 , and the main spindle 19 is driven rotationally on its axis by the main spindle rotation drive mechanism (not shown in the figures), and the work W held on the pallet P placed on the table 20 is thus machined by the tool T held on the main spindle 19 .
Waste produced by machining and cutting fluid supplied appropriately to where the tool T and work W contact drop from the waste removal hole 12 a onto the conveyor belt 52 . The waste is conveyed by the conveyor belt 52 and recovered in the collection box 55 , and the cutting fluid flows down and off the conveyor belt 52 into the storage tank 54 located below the conveyor belt 52 .
The pallet mounting unit 20 a of the table 20 is rotated on the C axis and indexed to a predetermined rotational angle position by the second table rotation drive mechanism (not shown in the figures), and the support unit 20 b of the table 20 is swiveled on the B-axis by the first table rotation drive mechanism (not shown in the figures) and indexed to a predetermined rotational angle position, to index the pallet P (the work W on the pallet P) to a specific rotational angle position on the C axis and a specific rotational angle position on the B-axis for processing. The tool changing device 40 also changes the tool T as needed through the tool changing opening 13 a in the left sidewall 13 of the bed 11 .
When the machining process is completed, the first table rotation drive mechanism (not shown in the figures) swivels the support unit 20 b of the table 20 on the B-axis to turn the work W on the pallet P upside down, and cutting fluid is then discharged from the nozzles 56 to remove any waste from the support unit 20 b , the pallet mounting unit 20 a , the pallet P, or the work W, for example. The removed waste drops through the waste removal hole 12 a onto the conveyor belt 52 whereby the waste is conveyed out from the working area and recovered into the collection box 55 .
The first table rotation drive mechanism (not shown in the figures) then again swivels the support unit 20 b of the table 20 on the B-axis to the upright horizontal position, and the pallet changing device 45 changes the pallet P through the pallet changing opening 14 a in the right sidewall 14 of the bed 11 .
In a machine tool 1 according to this embodiment of the invention the table 20 is disposed inside the space enclosed by the three sidewalls 13 , 14 , 15 of the bed 11 , both ends of the long sides of the first saddle 16 are supported on top of the right and left sidewalls 13 and 14 to move freely on the Y-axis, the second saddle 17 is disposed movably on the X-axis inside the frame of the first saddle 16 , and the spindle head 18 is disposed movably on the Z-axis inside the through-hole 17 b of the second saddle 17 . As a result, the first saddle 16 , the second saddle 17 , and the spindle head 18 can also be disposed above the top of the table 20 .
A machine tool 1 according to this embodiment of the invention makes it more difficult for cutting waste and cutting fluid to enter the Y-axis feed mechanism 24 and Y-axis guide mechanism 21 , the X-axis feed mechanism 25 and X-axis guide mechanism 22 , and the Z-axis feed mechanism 26 and Z-axis guide mechanism (not shown in the figures) when compared with a prior art machine tool in which the feed mechanism for moving the table and the guide mechanism for guiding table movement are disposed below the top of the table. Waste and cutting fluid can therefore be prevented from entering the Y-axis, X-axis, and Z-axis feed mechanisms 24 , 25 , 26 and the Y-axis, X-axis, and Z-axis guide mechanisms 21 and 22 using only the top cover 70 and third cover 63 , and separate covers for the Y-axis, X-axis, and Z-axis feed mechanisms 24 , 25 , 26 and the Y-axis, X-axis, and Z-axis guide mechanisms 21 and 22 are not needed. As a result, the parts count and the manufacturing cost of the cover 60 can be reduced, and maintenance of the cover 60 can be simplified.
The first saddle 16 is also rendered with a rectangular frame shape, the second saddle 17 is disposed inside the frame of the first saddle 16 , and the spindle head 18 is disposed inside a through-hole 17 b formed vertically through the second saddle 17 . Unlike the prior art machine tool, the saddle therefore does not project from the front and a support structure for the spindle head is not needed. Deflection and other deformation of the bed 11 , first saddle 16 , and second saddle 17 are thus prevented, and work W can be machined with high precision.
Play and a change in attitude can also be prevented when moving the first saddle 16 and spindle head 18 , and high precision machining is thus afforded, by driving both long-end portions of the first saddle 16 by means of a Y-axis feed mechanism 24 comprising two drive motors 24 a , ball screws 24 b , and nuts 24 c , and driving both ends of the spindle head 18 by means of a Z-axis feed mechanism 26 comprising two drive motors 26 a , ball screws (not shown in the figures), and nuts (not shown in the figures).
Yet further, by rendering a recess 16 a at the front outside surface between the ends of the long sides of the first saddle 16 , the front outside surface of the first saddle 16 can be prevented from striking a worker S working at the front of the bed 11 when the first saddle 16 moves to the front side of the bed 11 .
A pallet P on the table 20 can be swiveled and indexed on the B-axis by means of a first table rotation drive mechanism (not shown in the figures) and can also be rotated and indexed on the C axis by means of a second table rotation drive mechanism (not shown in the figures). The work W (pallet P) therefore needs to be mounted on the table 20 only once in order to complete a processing sequence, including machining the outside of the work W, thus improving efficiency and machining precision.
The tool changing device 40 and pallet changing device 45 also enable more efficient tool changing and pallet changing, the tool changing device 40 is disposed on the left sidewall 13 side of the bed 11 and changes tools through a tool changing opening 13 a in the left sidewall 13 , and the pallet changing device 45 is disposed on the right sidewall 14 side of the bed 11 and changes the pallets through a pallet changing opening 14 a in the right sidewall 14 . Thus rendering the tool changing device 40 and pallet changing device 45 on the sides prevents interference with tasks performed by a worker S at the front of the bed 11 .
Furthermore, when processing the work W is finished, the first table rotation drive mechanism (not shown in the figures) swivels the support unit 20 b on the table 20 180 degrees on the B-axis to invert the work W on the pallet P, and cutting fluid is then discharged towards the pallet P from nozzles 56 located below the table 20 to effectively and efficiently remove any waste accumulated on or clinging to the support unit 20 b , the pallet mounting unit 20 a , the pallet P, and the work W. Waste and cutting fluid are thus prevented from being removed with the pallet P and work W from the machine tool unit 10 . The processing cost can also be reduced because dedicated equipment for removing waste adhering to the work W is not needed.
A waste removal hole 12 a is rendered as an opening in the top of the base 12 of the bed 11 , and a waste recovery device 50 is disposed inside the waste removal hole 12 a . Waste and cutting fluid can thus be efficiently discharged from the opening of the waste removal hole 12 a in the base 12 and recovered by the waste recovery device 50 .
A preferred embodiment of the present invention is described above, and it will be obvious to one with ordinary skill in the related art that the invention is not limited to this embodiment.
A tool changing device 40 and pallet changing device 45 are disposed to the machine tool unit 10 in this embodiment of the invention, but the invention is not so limited as the machine tool unit 10 could be equipped with only the tool changing device 40 or only the pallet changing device 45 . In such an arrangement only the corresponding tool changing opening 13 a or pallet changing opening 14 a is rendered in one of the three sidewalls 13 , 14 , 15 of the bed 11 .
The arrangement of the tool changing device 40 and pallet changing device 45 is also not limited to the preferred embodiment described above. For example, a pallet changing opening 14 a can be rendered in any two of the three sidewalls 13 , 14 , 15 of the bed 11 so that the pallet changing device 45 delivers a pallet P from one pallet changing opening 14 a and removes the pallet P from the other pallet changing opening 14 a , thereby replacing the pallet P holding the processed work W on the table 20 with a new pallet P carrying unprocessed work W.
Yet further, cutting fluid is discharged from each of plural nozzles 56 in this preferred embodiment of the invention, but the invention is not so limited and the nozzles 56 could instead discharge compressed air. Furthermore, the nozzles 56 only need to be located below the table 20 , and are not limited to being located directly below the table 20 . The construction of the table 20 and the construction of the machine tool unit 10 are also not limited to this embodiment of the invention.
The rotational angle position of the table 20 when the cutting fluid is discharged from the nozzles 56 is also not limited to the 180 degree inverted position described above, and can be any angle of 90 degrees or more. In addition, discharging the cutting fluid from the nozzles 56 is not limited to after the table 20 has been swiveled 180 degrees on the B-axis, and the cutting fluid can be discharged while the table 20 is swiveling. In this situation the table 20 crosses the streams of discharged cutting fluid while the table 20 swivels. Swiveling the table 20 and removing waste by discharging cutting fluid are thus parallel operations, and the waste can be removed in less time and more efficiently.
Furthermore, pallets P (work W) are changed by the pallet changing device 45 in this embodiment of the invention, but a crane or other type of hoist device can be used to load the work W on the table 20 instead of using a pallet changing device 45 . Work W can be efficiently loaded and unloaded from the table 20 in this arrangement because the top cover 70 opens together with the doors 61 a and 61 b of the first cover 61 .
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Machine tool simplifying maintenance, reducing manufacturing costs, and enabling high precision machining. The machine tool is equipped with: a bed furnished with a rectangular base, right and left sidewalls provided standing either side of the base, and a rear sidewall provided standing along the back of the base; a table disposed in the space surrounded by the three sidewalls; a first saddle shaped in the form of a rectangular frame shape, provided free to shift back and forth supported on the tops of the left and right sidewalls; a second saddle penetrated by a perpendicular through-hole and arranged free to shift sideways inside the first saddle frame; and a spindle head arranged free to shift perpendicularly inside the through-hole in the second saddle; and a main spindle arranged over the table and supported by the spindle head free to rotate centered on its axis.
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FIELD OF THE INVENTION
The instant invention relates to a method and apparatus for protecting a flange. More particularly, the invention relates to a method and apparatus for protecting a flange from corrosion or fire in the splash zone of a marine environment.
BACKGROUND OF THE INVENTION
Flanges, i.e. ribs or rims extending from a pipe, are often used when connecting two pipes together because of the ability to disassemble the pipes when necessary. The flanges may be part of the pipe itself, such as a flanged-end pipe, or may be connected to the end of the pipe via a variety of means. Flanges which connect to the end of the pipe include, for example, screw-on flanges, slip-on flanges, socket-weld flanges, lap-joint flanges, welding neck flanges, and blind flanges. These flanges are illustrated in, for example, Perry's Chemical Engineers' Handbook, Sixth Edition, McGraw Hill Book Company, 1984, p. 6-46, which is incorporated by reference. The flanges often have a gasket between them which, unfortunately, may be flammable and could result in a leak in the event of a fire. The flanges are bolted together. Typical gaskets and bolting means are illustrated in, for example, Perry's Chemical Engineers' Handbook, Sixth Edition, McGraw Hill Book Company, 1984, pp. 6-46 through 6-50, which is incorporated by reference.
Often pipes connected by flanges are to be utilized in applications which require that the pipes and flanges be subjected to an external environment which is corrosive and/or subject to fire. An example of such is offshore drilling and production platforms, or other marine structures, wherein the pipes and flanges are subjected to the corrosive salt water of the ocean and possible fires due to the flammability of the produced oil and gas. While methods and apparatuses have been developed which are used to protect the pipes from the corrosive environment and fire, the methods and apparatuses are generally not effective when used for a flange. Methods and apparatuses to protect pipes include those of U.S. Pat. Nos. 5,087,154; 5,591,265; and 5,226,751.
U.S. Pat. No. 5,087,154 relates to a protective coating which has two uninterrupted and encapsulating and superposed layers of a marine resistant epoxy composition and a thin layer of reinforcing composition between the layers. Correspondingly, U.S. Pat. No. 5,591,265 relates to a protective coating which has a formwork around a tube to be protected, an annular space between the tube and formwork, a means to apply a curable resin to the annular space, a seal means, and a support ring secured to the tube. Unfortunately, the protective coatings taught in these two patents are adapted especially for pipes and if used on a flange would be difficult to secure around the flange and completely encompass the flange due to the flange's shape. Therefore, the flange would not be fully protected in many instances. In addition, the protective coatings of the two patents are not adapted for removal and replacement. Therefore, if inspection, repair, or replacement of the flange becomes necessary after the protective coating is applied, then the protective coating would have to be removed at considerable cost or the entire flange would have to be cut from the pipe.
U.S. Pat. No. 5,226,751 relates to a process for creating a controlled environment about a submerged pile by placing a jacket around the pile and then injecting air and a preheated gas into the jacket to dry the pile. After the pile is dry, the jacket is filled with a firm resilient non-corroding compound such as an expanding closed cell foam formed from liquid chemicals or epoxy resins. Unfortunately, if this process was employed on piling containing a flange, then the jacket would leave a very large annular space around the pipe where the flange is located. This would necessitate using a large amount of the very expensive filler. In addition, if the flange needed to be inspected, then it would require removing the protective covering which covers the pipe, as well as, the flange.
Another method which is often employed to protect flanges is that of cathodic protection. Cathodic protection, as described in, for example, Encyclopedia of Science and Technology, Vol. 4, pp. 440-445, McGraw-Hill, 1992, generally involves applying a cathodic potential, or current, to the flange. The cathodic potential prevents the flange from undergoing an anodic reaction, M→M n+ +ne - , which causes corrosion. This is often achieved by applying a cathodic current through an auxiliary electrode (impressed current) or by coupling the metal to be protected with a metal having a more negative open circuit potential (sacrificial anode). Unfortunately, such cathodic protection is often uneconomical. Additionally, cathodic protection is not particularly effective for flanges which are subject to both wet and dry conditions, such as flanges in a splash zone of an offshore drilling and production platforms, or other marine structures.
It would be desirable if an alternate method and apparatus suitable for protecting flanges from corrosion and/or fire could be developed. It would be beneficial if such an apparatus was adapted to be removed so that the flange could be inspected and repaired when necessary. It would be advantageous if the apparatus could be reused after removal from the flange. It would further be desirable if such flange protection could be accomplished in an environment which is subject to both wet and dry conditions, impact, abrasion, or ultraviolet light.
SUMMARY OF THE INVENTION
An apparatus and method have been discovered which protects flanges from corrosion and/or fire. The apparatus comprises a corrosion-resistalnt housing which is adapted to encapsulate a flange to be protected. The housing comprises a first section and a second section which are attached to define a substantially air-tight annular space. A first port is located on the housing and is adapted for the injection of a corrosion-inhibiting substance into the annular space. A second port is located on the housing and adapted for the expulsion of fluids which are present in the annular space prior to injection of corrosion-inhibiting substance. Advantageously, the flange protection apparatus may be removed and reused. In addition, the flange protection device may be particularly useful in corrosive, wet-dry, and fire-prone environments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a production platform showing a flange located in the splash zone in a marine environment.
FIG. 2 is a top view of a flange protection device of the instant invention.
FIG. 3 is a cross-section of a flange protection device of the instant invention in conjunction with a pipe and flange.
FIG. 4 is an open view of a flange protection device of the instant invention in conjunction with a pipe and flange.
FIG. 5 is an open view of a flange protection device of the instant invention, its hardware, and a corrosion inhibiting liquid.
DETAILED DESCRIPTION OF THE INVENTION
The instant invention is particularly useful for protecting flanges in a corrosive environment. As used herein, "corrosive environment" means any environment which reacts with the flange to electrochemically degrade the flange. The corrosion reaction is often of the form M→M n+ +ne - , wherein M is the metal from which the flange is made, M n+ is an oxidized form of the metal after corrosion, e is an electron, and n is the number of electrons. Corrosive environments often include water or air which contains NaCl, high temperatures, alternate wet and dry conditions, acidity, or basicity. Among applications for which the instant invention is particularly useful are offshore drilling and production platforms, or other marine structures, which due to their location in the splash zone or tidal zone, subject a flange to a corrosive environment. In addition, the flange protection device is useful for applications which may subject the flange to a risk of fire.
The apparatus of the instant invention employs a housing which is adapted to encapsulate a flange. The particular material of which the housing is comprised is not particularly important so long as the material is corrosion-resistant, i.e., the material does not electrochemically degrade substantially when subjected to a corrosive environment for extended periods of time. In addition, the material is preferably fire-resistant if the device is to be utilized for an application which may subject the flange to fire. It is also preferred that the material be impact and abrasion-resistant if it is to be subjected to such forces as waves, tides, or floating debris. Particularly preferred materials for the housing are steel, thermoplastics, thermoset composites, or mixtures thereof. A particularly preferred material is a thermoset composite due to its excellent ability to resist degradation by chemicals and ultraviolet light.
The shape of the housing is not particularly critical so long as an annular space exists between the housing and the flange. Since the annular space will be injected with a corrosion-inhibiting substance, as described below, it is usually advantageous to select a shape for the housing which will minimize the volume of annular space. In this manner, the amount of liquid which is necessary to fill the annular space will also be minimized. A particularly preferable shape, therefore, is hemicylindrical as shown in FIG. 3.
Another consideration in regard to shape is the type of material to be utilized. As one skilled in the art will appreciate some materials are more difficult to mold into certain shapes, or when molded into a certain shape are less strong. For example, many composite materials are difficult to mold into shapes having sharp edges or contours, for example, 90° angles, while maintaining the structural integrity of the shape. For this reason, it may be desirable to avoid such shapes having 90° angles and employ shapes which tend to be more circular or cylindrical when utilizing composite materials.
The housing is comprised of two or more sections in order that the housing may be easily removed when inspection or repair of the flange is necessary. The sections are attached such that the annular space is substantially airtight and watertight. In this manner, no corrosive elements may enter the annular space and attack the flange. The means of attachment may be any means which facilitates a substantially airtight and watertight fit between or among the sections. While the actual number of sections may depend upon the size and shape of the flange to be protected, usually two mirror-image sections are most practical in order to facilitate the attachment, i.e., typically it is less burdensome to attach two sections as opposed to three or more.
As stated above, the attaching means may be any means which facilitates a substantially airtight and watertight fit between or among the sections. It is also preferable that the attaching means be such that the sections may be detached relatively easily when inspection or repair of the flange becomes necessary. The actual attaching means employed is often dependent upon the type of material used for the housing, as well as, the number of sections in the housing. For instance, if the material is fairly rigid, such as steel, then a bolt and nut often adequately serve to attach the sections. However, if the material is pliable, for example, a thermoplastic such as rubber, then often a clamping means is most desirable to press the sections together. In some instances, a glue may even be utilized so long as the glue provides an airtight and watertight seal between or among the sections and yet still allows one to detach the sections relatively easily if inspection or repair of the flange is necessary.
While it is usually not critical to the flange protection device if the sections of the housing are adequately attached, in some instances a sealing means between or among the sections of the housing may be useful. Such a sealing means is most often necessary when the housing is comprised of an inflexible material such as steel because an incomplete seal between or among the sections may exist due to the sections not fitting perfectly together. On the other hand, if the housing is comprised of a thermoplastic such as rubber, then often no seal is necessary.
The sealing means should be corrosion-resistant and act to prevent leakage of air or water into the annular space. Along the same lines, the sealing means acts to prevent leakage of a corrosion-inhibiting substance from the annular space to the external environment. Such a sealing means may be simply a piece of rubber which contacts the lateral surface of a housing section at the point where the section is attached to another section. Such a means may be referred to simply as a seal or a gasket.
A first port is located on the housing and is adapted to allow a corrosion-inhibiting substance to be injected into the annular space. A second port is also located on the housing and adapted for expelling any fluids, whether they be liquids or gases, which are present in the annular space prior to the injection of corrosion-inhibiting substance. The fluids which are present prior to injection often include seawater, freshwater, air, or combinations thereof when the flange is being utilized in the splash zone of a marine environment. The ports are preferably capable of being opened or closed by, for example, a valve.
The first or second port is also useful for removing, for example draining, the corrosion-inhibiting substance when repair or inspection of the flange is necessary. In addition, either port or an additional port may be employed to reduce the pressure within the flange protection device in the event of a leak from the flange. If leaking from the flange is likely then it may be desirable to include a pressure sensing device within the flange protection device. In this manner, if a leak does occur, the port may be opened to prevent the flange protection device from bursting.
The first and second port may be located anywhere on the housing so long as the existing fluids in the annular space are ejected upon the introduction of corrosion-inhibiting substance. Generally, it is most convenient and practical to orient the two ports such that gravity may be used advantageously. For example, when the first port is located below the second port, then the introduction of corrosion-inhibiting substance pushes the existing fluids upward and out of the second port into the external environment. When substantially all of the annular space is filled with the corrosion-inhibiting substance and, correspondingly, substantially all of the existing fluids have been expelled, then the ports are closed and the flange is protected.
The corrosion-inhibiting substance for use in the annular space of the present invention may be any substance which either retards, slows, or reverses electrochemical degradation of the flange. Likewise, a corrosion-inhibiting substance may break down the corrosion product such that the flange is cleaned. The type of corrosion-inhibiting substance employed may be a solid liquid, gas, foam, gel or any other form which may be injected into the annular space. It is generally preferable that the substance be a liquid at 25° C. such that the substance may be easily injected into the annular space, drained and replaced easily if such becomes necessary. It is also generally preferable that such a liquid does not freeze and expand at temperatures to which the flange protection device will be subjected. In this manner, the housing of the flange protection device will not be subjected to stress due to the expansion of the substance within the annular space.
The corrosion-inhibiting substance may vary depending upon the amount of time the flange is to be protected, the susceptibility of the particular flange to corrosion, and the amount of corrosion which may have already occurred. One skilled in the art will readily recognize that if a flange is to be protected for a period of, for example, 10 years then a different corrosion-inhibiting substance may be chosen than if the flange is only in need of protection for a period of, for example, 1 year. Likewise, one skilled in the art will readily recognize that if a particular flange is very susceptible to corrosion then a stronger corrosion inhibitor may be necessary and if substantial corrosion of the flange has already occurred, then an inhibitor which breaks down the corrosion product and cleans the flange may be necessary.
Corrosion-inhibiting substances useful in the invention may be prepared individually or may be obtained commercially. Among corrosion-inhibiting substances which are useful in the instant invention include citric acid-type metal conditioners and rust removers. These corrosion-inhibiting liquids typically comprise citric acid, esters, or mixtures thereof. Other corrosion-inhibiting liquids include Bioguard™ available from Royal Lubricants Company, Inc., Rusteco R-200-3™ available from TMT Services Corp., and other commercially available corrosion inhibitors or mixtures thereof. Alternatively, two or more substances which do not individually exhibit corrosion-inhibition properties could be injected into the annular space and react to form a corrosion-inhibiting substance within the annular space.
FIG. 1 illustrates an unprotected flange located in the splash zone of a production platform. FIGS. 2 through 5 illustrate different views of a preferred flange protection device according to the present invention. There is illustrated a first pipe 10 having an extended rim 12 on each side and connected to a second pipe 11 having an extended rim 13 on each side. A bolt 14 and a bolt 15 extend through the rims and hold the pipes together. The flange protection device, 6, encompasses the flange and that part of the pipe, 16, immediately adjacent to the flange. The flange protection device, 6, is comprised of two mirror-image, hemicylindrical sections, 17 and 18. Each hemicylindrical section is comprised of a thermoset composite and has a top neck, 19, and a bottom neck, 20, which are at opposing ends of the flange protection device. The necks substantially conform to the shape of the pipe but are a bit larger in diameter than the pipe. In this manner, if the pipe has a corrosion protection substance on it such as ArmorGard™ or RiserClad™ available from Riserclad International Inc., then the necks of the flange protection device will still be large enough in diameter to surround the pipe. The necks are in communication with the pipe (a seal may be used if necessary) to prevent ingress of air and water, as well as, egress of corrosion-inhibiting substance.
A first port, 21, is located immediately adjacent to the bottom neck, 20, of a hemicylindrical section, 18, of housing. The port is adapted such that when it is open, a corrosion-inhibiting substance may be injected into the annular space, 23. A second port, 22, is located immediately adjacent to the top neck, 19, on the mirror-image hemicylindrical section, 17, of the housing. The second port is adapted such that when it is open, any fluid which are present in the annular space, 23, prior to injection of corrosion-inhibiting substance are expelled. Upon the filling of the annular space with corrosion-inhibiting substance and the expulsion of substantially all of the prior fluids, the first port 21 and the second port 22 are closed. A valve or plug is adapted to control the opening and closing of the port.
A rubber seal, 24, is located between the two mirror-image hemicylindrical sections along the length. The seal acts to provide a cushion between the two sections and allow them to be fastened together firmly without harming the sections of housing. Rims, 25 and 26 extend the length of each section of housing in the z-plane direction, i.e., out of and into the plane of the figure. The rims are comprised of the same material as the housing and are part of each section of the housing. Five bolts, 27, extend through corresponding holes on each rim, 25 and 26, each bolt having a nut, in order to fasten the two sections of housing together such that the annular space is airtight.
The flange protection devices and methods of the instant invention allow the flanges to be protected from corrosion for extended periods of time. Surprisingly, it is contemplated that flanges may be protected from substantial corrosion for as long as 2, preferably as long as 5, more preferably as long as 10 or more years. Periodically, it may be necessary to inspect and/or repair the flanges due to regulatory or safety requirements or harsh weather such as tropical storms, heat, or cold. When such inspection or repair becomes necessary, the bolts, 27, are removed and the sections, 17 and 18, of the housing are removed to reveal the flange. It may be desirable in some instance to open port, 21, in order to drain the corrosion-inhibiting substance before removing the bolts. Depending on the corrosion-inhibiting substance, it may be desirable to separate the substance from the oxidized material, e.g., rust, which may be present in the substance. This may be done by, for example, decanting if the substance is a liquid. in this manner, the corrosion-inhibiting substance may be reused. After the inspection and/or repair has been completed, the flange protection device may be reused on the same flange or an alternate flange.
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Flanges are often subject to corrosive marine environments and/or fire-prone environments when they are employed in applications such as offshore drilling and production platforms, or other marine applications. An apparatus and method to protect the flange from such corrosive environments and fire has been discovered. The apparatus is removable and reusable which allows the flange to be inspected and repaired when necessary.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 940,508, filed Dec. 11, 1986, now abandoned which in turn is a continuation-in-part of application Ser. No. 904,768 filed 9/5/86, now abandoned which in turn is a continuation of application Ser. No. 600,363 filed 4/13/84, now abandoned.
cl BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for the spinning of fiber yarns, possibly comprising at least one core.
The production of the threads can be effected on numerous spinning systems. Ring-traveler systems, self-twisting systems, free-end systems, braiding systems, etc. are known.
One special type of thread consists of the core threads in which a core thread is wrapped with a sheathing of staple fibers. Methods of producing core threads are described, in particular, in U.S. Pat. Nos. 1,373,880, 2,024,156, 2,210,884, 2,313,058, 2,504,523, 2,526,523, 3,017,740 and 3,038,295.
The production of core threads can be effected on numerous systems of spinning commonly employed for the manufacture of threads from staple fibers. However, particularly in the case of the ring-traveler system, spun core threads generally have the drawback of being limited in speed of production to the speed of the machines used and therefore to the system of twisting employed.
Self-twisted core threads are known from U.S. Pat. No. 4,033,102. An original manner of producing self-twisted core threads is described in French Patent Nos. 7,918,173 and 7,913,995. The advantage of this process is that it requires only unidirectional movements of constant speed. On the other hand, its great drawback is that it imposes sudden, extensive variations in twist, and therefore in tension on the thread, which limit the effectiveness thereof with respect to the speed of production and increase the danger of the sliding of the cover fibers with respect to the core.
French Patent No. 8,111,642 avoids these drawbacks and permits a high speed of production without sliding of the cover fibers with respect to the core and produces, after doubling, a unidirectional torsion of the twist. Its great drawback is that it requires the use of one or more continuous filaments serving as vector for the cover fibers, which may be a drawback in the final product.
The present invention makes it possible to obtain fiber yarns with or without cores with an extremely high speed of production, obtained by the consolidating of the strength of the fiber yarn, preferably at the time when it must withstand stresses.
Conventional spinning processes, such as described in U.S. Pat. Nos. 4,414,800 and 4,484,436, include the following steps:
(a) drafting at least two rovings of fibers to intermediate yarns;
(b) false twisting the intermediate yarns;
(c) assembling the intermediate yarns; and
(d) twisting the assembled intermediate yarns to a twisted yarn.
The twisting of the assembled intermediate yarns may be accomplished by winding the assembled intermediate yarns by means of a two-for-one twister to a twisted yarn.
Such conventional processes produce a fiber yarn which primarily has two twisted and assembled intermediate yarns without a core. However, it is also possible that a core may be present.
SUMMARY OF THE INVENTION
The present invention relates to the problem of breaking of the yarn during the spinning process. Breaking occurs particularly in two circumstances:
(1) at the start of the spinning (or the piecing) of the yarn; and
(2) during twisting of the assembled intermediate yarns to a twisted yarn.
The present invention is directed to improvements to conventional spinning processes which serve to overcome the problem of breaking.
It is therefore an object of this invention to provide a process for spinning a yarn of fibers by drafting at least two rovings of fibers to intermediate yarns, false twisting the intermediate yarns, assembling the intermediate yarns and twisting the assembled intermediate yarns to a twisted yarn, which process operates in an efficient manner and can be advantageously operated efficiently at high speeds.
Another object of this invention is to provide a spinning process in which breakage of the yarn is decreased.
A further object of this invention is to provide a process for spinning a yarn which produces a yarn of increased strength.
The foregoing and other objects are attained in accordance with the present invention.
In one embodiment, a process is provided for start spinning or piecing at least two yarns of fibers, which process includes forming strands for start-spinning or piecing by introducing a continuous filament into each roving, false twisting the strands, assembling the strands at a given point of convergence, cutting each filament upstream of its introducing point, removing the filament from the strands and twisting the strands without the filament to a twisted yarn.
The present invention provides a valuable advance over the state of the art. When starting a spinning process, such as after a break in the yarn, the strength of the intermediate yarn drafted from the rovings of fibers is not sufficient to allow the process to work correctly. To obviate this problem, applicant has discovered that by adding continuous filament to each roving of fibers upstream of the drawing rolls, the strands of drafted rovings and continuous filaments advantageously run through the drawing rolls and the twister.
The present invention provides a process which can produce a fiber yarn without a core. Therefore, the continuous filament is needed only temporarily and means are provided for its removal. Thus, continuous filament is advantageously cut upstream of its introducing point, that is, upstream or before the drawing rolls. Further, the cut filament can be separated from the yarn by a removing device, such as a suction device, preferably located upstream of the winding roll and final twisting means.
The continuous filament is "continuous" only in the sense that it runs continuously when necessary. Clearly, the continuous filaments are not introduced into the rovings when not necessary and, in any case, are removed before final twisting. Preferably, the final strands which are twisted do not contain the continuous filaments.
A further embodiment of the present invention concerns the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn. By the present invention, this problem of breaking is advantageously avoided by introducing a false twisting of the assembled intermediate yarns, supplementary to the false twisting of the intermediate yarns, before the last twisting.
These advantages are achieved by a process for the spinning of fiber yarns in which at least one roving of fibers is drawn between feed points of said roving and pairs of drawing rolls, upstream of which a continuous filament is introduced and, in accordance with the invention, the strands formed by each roving of fibers and each continuous filament are twisted by a twisting member, preferably a friction-twisting member, by causing them to converge at one and the same point located upstream or downstream of the twisting member. The thread thus formed is passed through a pair of delivery rolls located behind the twisting member, the thread is wound onto a suitable support and the thread thus formed by the strands is possibly doubled on a doubling frame.
This process is such that at a given precise point the thread is imparted sufficient coherence to permit the doubling. Thus the fiber yarn is not broken. The coherence is preferably imparted to the thread between the point of the taking on of twist and the point of the winding of the thread.
The thread which is thus formed in accordance with the invention is doubled on a conventional doubling frame, for instance of ring-traveler, double-twist or double-stage type in order to impart the final twist.
In accordance with another embodiment, the coherence is imparted to the thread by sizing the fibers, namely by the addition of a cohesive product to the fibers, for instance, before fiber rovings are drawn, in particular at the time of the preparation of the rovings or, more preferably, after the twisting of the strands and before the winding up thereof.
In accordance with the invention, the thread which is wound up is such that there is no assembling twist, which is avoided by adjustment of the tension. In the event that such assembling twist should exist due to the irregularities in operation of the twisting member related to the irregularities in mass of the thread, it is a non-uniform random twist or alternate twist or self-twist. It is therefore not uniform either in pitch or in intensity. The invention makes it possible to avoid such a undesired assembling twist of the wound-up thread.
In order to produce a core-less thread, the continuous filament or filaments are cut before the winding is effected. The continuous filament or filaments are preferably cut upstream of the drawing rolls. This constitutes a method of starting manufacture which is in no way limitative and other manners of procedure can be contemplated.
In accordance with one particular embodiment of the invention, at least two rovings of fibers are drawn separately between feed points and pairs of drawing rolls; the continuous threads are fed; they are introduced into said rovings upstream of the different drawing rolls; and the strands formed are caused to converge at a given point of a twisting member. The strands formed are passed through a pair of delivery rolls and the continuous filaments cut, upstream of the drawing rolls, before the winding up of the remaining assembly. The assembly formed by the fibers is then placed on a doubling frame where strength of the thread is assured between the point of winding of the thread on the bobbin and the point of the taking on of twist.
This purpose is also achieved by a device for the spinning of fiber yarns comprising possibly at least one continuous filament and having:
means for producing at least two strands of fibers,
means for feeding at least one continuous filament into each strand,
means for the false twisting of the strands, preferably by friction,
means for regulating the tension of the strands, preferably located downstream of the twisting means, and possibly means for eliminating the continuous filament,
winding means,
means for twisting the yarn,
means imparting sufficient coherence to permit doubling.
Preferably, the coherence means are located between the point of winding of the thread on the bobbin and the point of the assumption of torsion upon doubling.
In accordance with the invention, the thread which is wound has a very special structure. In fact, it is formed of at least two strands placed side by side and having a small residual twist, possibly alternate and very slight, sufficient to assure coherence of the cover fibers on the filament and insufficient to cause the assembling of the two strands by self-twisting in uniform and constant manner.
Finally, the thread after doubling is such that the fibers are all substantially parallel to each other in the axis of each strand with a variation equal to the very slight residual twist present in the thread before doubling, but such that one can dissociate the two strands by untwisting.
There is actually concerned a two-strand thread.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and the advantages which it provides will, however, be better understood from the embodiments of its reduction to practice which are given below by way of illustration but not of limitation and which are shown in the accompanying drawing, in which:
FIG. 1 is a diagrammatic view, in perspective, of a spinning apparatus before the stopping of the continuous filament in the event that the point of convergence is upstream of the twister;
FIG. 2 is a diagrammatic view, in perspective, of an apparatus for the obtaining of a double thread before the placing in torsion and after the cutting of the filament, in the event that the point of convergence is downstream of the twister;
FIG. 3 is a perspective view of a device which makes it possible to obtain strength of the yarn between the point of winding of the yarn on the bobbin and the point of assumption of torsion of a doubling frame;
FIG. 4 is a sectional view through the device of FIG. 3, mounted on the winding reel of a double-twist doubler;
FIG. 5 is a perspective view of a variant of the device of FIG. 3;
FIG. 6 is a perspective view of another variant of the device of FIG. 3;
FIG. 7 is a diagrammatic view of the device of FIG. 5, mounted on a ring-traveler doubling frame;
FIG. 8A is a view of the thread after doubling in accordance with the invention;
FIG. 8B is a view of a thread of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the invention, a spinning process is carried out by drawing a roving of fibers 5a between a feed point 2a and a pair of drawing rolls 4a. The drawing system comprises furthermore a pair of drawing belts 3a. Parallel to this, a roving of fibers 5b is drawn separately by a drawing system comprising a feed point, namely a pair of feed rolls 2b, a pair of drawing belts 3b and a pair of drawing rolls 4b.
Upstream of the drawing rolls (4a, 4b) a continuous filament (6a, 6b) is introduced. There are thus formed two strands, each consisting of a roving of fibers and a filament. The strands thus formed are twisted together by a twister 7 and are guided by two guides 8 and 9. The two strands then pass through a pair of rolls 10 before being drawn in by a suction device 13 before eliminating the continuous filaments for instance by cutting, by means of a pair of manual shears, upstream of the drawing rolls.
The continuous filaments which have thus been cut are therefore led away to waste by the suction device 13.
FIG. 2 shows the spinning device after the cutting of the filaments, when the yarn of fibers is wound on a roll 11.
It is important to have a number of fibers in sufficient cross section relative to the coherence of the fibers, the cleanness of the roving and the tension between the drawing rolls 4 and the delivery rolls 10. With respect to the coherence between the fibers, it may be of interest to add to the fibers, at the time of the preparation of the rovings, a size which increases this coherence between the fibers, for instance, a paraffin size or a size containing colloidal silica. This also has the effect of facilitating the doubling.
In the event that the point of convergence is upstream of the twisting member, it is also important to regulate the tension between the drawing rolls and the delivery rolls 10 in such a manner as to have a suitable distance h between the drawing rolls 4 and the point of convergence 12 of the threads, relative to the twist imparted and the speed of travel. In fact, a twist is present in each of the individual strands between the point of convergence 12 of the strands and the point where the strand is grasped last by the drawing rolls 4, but this twist is not incorporated in the resultant thread. This twist is present in the strands prior to the convergence in an equilibrium amount which depends on the geometry of the system and the spinning parameters. This state of affairs described above may, in practice, be modified. In fact, irregularities being present at random in the strands, a part of the twist is incorporated in strands in a randomly varying manner. Such a twist is, however, of slight intensity.
If the tension is too little, then too little torsion is present in the strand between the drawing rolls 4 and the point of convergence 12, which results in losses of fibers at the outlet of the drawing rolls 4, as a result of poor interlocking of the fibers. For example, excellent results have been obtained with a speed of 215 meters per minute with a draw, between the drawing rolls 4 and the delivery rolls 10, of 1.53% and a thread of 2×25 tex composed of 45% wool of 27 microns and 55% polyester of 3 denier. Thus, the difference in speed between the drawing rolls 4 and the delivery rolls 10 is adjusted as a function of the spinning parameters and the speed of travel. If the tension, on the other hand, is too great, the thread is excessively tensioned, resulting in the risk of breakage.
In the event that friction-twisting members are employed which assure both a component of twist and a component of advance of the thread, it may be of interest to adjust the tension of the thread by varying this component of advance, independently of the adjustment of the tension between the delivery and drawing rolls. For example, when two endless crossed belts are used, this adjustment is effected by variation of the angle of the two belts.
By the present invention, the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn is advantageously avoided. When the yarn of fibers is at the stage of the doubling, its strength is, in general, too slight to permit operation without problems and the thread frequently breaks between the point of winding of the thread on the bobbin and the point of the assumption of twist.
Now it has been found that a very slight additional coherence was sufficient to assure the winding of the thread. As a function of the initial coherence of the fibers, a simple cohesive sizing may be sufficient. This cohesive product may be added to the fibers either at the time of the preparation of the rovings or at the location of the spinning machine, between the strand twisting member and the winding member.
In cases in which this is not sufficient or in cases in which sizing is not to be effected, it has been found that the addition of a few turns of twist, by means of a false twisting device, made before the final twisting was sufficient to assure a good winding.
False twisting devices are known. They may be rotary or operate by friction. They may be static and a single winding on a rod may assure a twisting by rolling upstream of the rod when pulling on the thread, provided that the angle of the thread with respect to the rod, the diameter of the rod as a function of the diameter of the thread, as well as the pitch of the thread on the rod and the coefficient of friction of the material of the rod are properly selected.
The example of FIG. 3 is a device which satisfies these requirements. It consists of a body 14 of light material which supports a rod 15 having the form of a semicircle arranged on the upper part of the body 14.
The use of the device of FIG. 3 will, however, be better understood from FIG. 4 which shows a cross section through a double-twist doubling spindle in which the bobbin of thread 16 is placed on the pot 17 where it is centered by the centerer 18. The unwinding thread 19 upon leaving the bobbin passes through the eye 20 of the winding reel 21. The thread is then wound on the rod 15 which is supported by the body 14, itself fastened by any means (not shown) on the reel 21. After having effected a certain number of turns, the thread returns into the body of the extender 22 where it will receive the first turn of twist imparted by the torsion disk (not shown) in order then to pass between the pot 17 and the anti-balloon wire 23 where it receives the second turn of twist before being wound on a bobbin (not shown).
In general, in a double-twist doubling machine, the tension of the thread and therefore the number of winding turns on the torsion disk is adjusted by a spring piston, a torsion blocker, not shown, which is located in the extender 22.
In the case of the use of the device according to the invention it is necessary either to remove this piston and thus the twist moves back to the rod 15, or to have a distance between this piston and the rod 15 which is less than the length of the fibers.
When using the device, the tension of the thread is adjusted by varying the following parameters:
number of turns of winding of the thread 19 on the rod 15;
diameter of the rod 15;
coefficient of friction of the material of the rod 15;
angle alpha formed by the thread 19 and the rod 15 at the time when the thread arrives in the rod.
One can vary the rotation of the reel 21 by conventional means, for instance its weight, its coefficient of friction, etc. One can, as in the case of a conventional double-twist doubling machine, vary the force of the spring of the torsion blocker, in the event that one is used.
For example, good results have been obtained with the thread of 2×25 tex described previously on a double-twist doubling frame with a spindle speed of 11,000 rpm and a twist of 371 turns per meter, namely a developed length of 59.2 meters per minute, using the device described in FIG. 4 in which the thread made one turn on a spring steel rod of 0.5 mm diameter, without using a twist blocker.
Good results were obtained with a thread of 2×33 tex one of the strands of which is formed of a filament of 300 denier of bright triacetate, without fiber coverage and the other strand is formed of 100% acrylic fibers dull, 3 denier, without filament. The assembly being twisted to 260 turns of spindles at a double-twist spindle speed of 10,000 rpm using the device described in FIG. 4 in which the thread 19 made two winding turns on the rod 15 which had a diameter of 0.25 mm, and without using torsion blocker.
A variant of the device is shown in FIG. 5, in which the thread is wound on a straight rod.
As a function of the threads to be doubled, one can have different angles between the rod and the vertical so as to change the angle of the thread with respect to the rod in order to vary the intensity of false twist.
The examples of forms of the device described are given by way of illustration and not of limitation. The only requirement is that there is a winding of the thread on the rod with a suitable angle of the thread with respect to the rod. More generally, one uses any device which permits false twisting between the winding-on and the assumption of twist, which permits the winding of the thread upon the twisting without it breaking due to its small strength.
Another variant of the device is shown in FIG. 6 where the rod is spiraled in the shape of a cone.
In the event that doubling is effected by a different doubling technique, for instance with a ring doubling frame as shown in FIG. 7, it will be sufficient to place a rod 24 between the bobbin 25 and the delivery rolls 26 in order to have a certain angle of the thread with respect to the rod so as to impart sufficient false twist for the winding, in order to obtain a distance between the rod and the delivery rolls less than the length of the fibers. In this case the tension is determined by the weight of the traveler 27.
In the event that doubling is effected by the double-step doubling technique, it will be sufficient to adapt the device of FIG. 7 to the first doubling assembling step.
Thus, in accordance with the invention one obtains a yarn of fibers comprising at least two strands which does not have any discontinuity such as knots, splices or stoppage points and which permits the production of bobbins of thread of large weight, for instance of a weight of at least 1 kg in the case of fine threads, for instance of about 10 tex, and bobbins of thread of at least 10 kg in the case of thick threads, for instance threads of about 1000 tex.
One such thread is shown in FIG. 8A. As can be seen, the fibers 28 are substantially much more parallel to each other than the fibers 29 of a thread of the prior art, all other things being equal.
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The present invention relates to a process for start spinning or piecing at least two yarns of fibers, which process includes forming strands for start-spinning or piecing by introducing a continuous filament into each roving, false twisting the strands, assembling the strands at a given point of convergence, cutting each filament upstream of its introducing point, removing the filament from the strands and twisting the strands without the filament to a twisted yarn. This process serves to overcome the problem of breaking at the start of the spinning. Also by the present invention, the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn is avoided by introducing a false twisting of the assembled intermediate yarns, supplementing to the false twisting of the intermediate yarns, before the last twisting.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to an assembly comprising a component and an axial limit stop device intended to be placed in a bore of said component in order to retain an element therein. The field of use of the invention is in particular the field of dentistry, the aim being to retain a transfixing screw in a bore of a dental prosthesis that is intended to be attached to a dental implant.
[0002] The document EP 0 801 544 discloses a dental abutment intended to be attached to and fixed on a dental implant, which is itself intended to be inserted into the maxillary or mandibular bone of a patient. The dental abutment subsequently receives a final dental prosthesis made of ceramic or metal. The dental abutment has a continuous bore in which an axial limit stop device is arranged, which is intended to ensure the axial retention of a screw held captive in the bore of the abutment. The threaded shank portion of the screw is intended to be received by screwing in an internally threaded bore of the dental implant. The dental abutment is fixed to the dental implant by fixing means (specifically a screw) passing through the dental abutment, hence the expression “transfixed dental abutment”, and more generally “transfixed component”. The axial limit stop device has a radially slit ring, which simultaneously engages under the screw head and in an annular groove formed in the bore extending through the abutment.
[0003] In the event of an excessive screwing torque being imparted to the screw, the latter may sustain damage, especially by breaking in the area of its shank. It is then desirable to remove what remains of the screw in the continuous bore of the abutment, in order to be able to insert a new screw there. However, the slit ring of document EP 0 801 544 is unfortunately very difficult or even impossible to remove, mainly on account of the very small dimensions of the components in question (dental abutment and slit ring). Thus, any damage to the screw renders the dental abutment unusable. The practitioner is then compelled to use a new dental abutment provided with an intact screw.
[0004] Resorting to a new dental abutment is not in itself a great inconvenience, since it is a component of which the shape is not adapted to each patient and of which the practitioner has several models. A standard and rapid exchange is thus possible.
[0005] For many years, it has been sought to limit the number of components by managing without dental abutments for attaching and fixing a final dental prosthesis to a dental implant inserted in the maxillary or mandibular bone of a patient. To do so, it has been proposed to insert the screw directly into a bore formed in the final dental prosthesis. The fixing screw can be driven in rotation by means of a screwing tool which accesses the screw head by way of an access well that communicates with the bore (in most cases obliquely intersecting the bore) in which the screw is retained. These dental prostheses are often called “transfixed dental prostheses” since the screwing tool and the screw pass right through them when they are being fixed. However, in the event of damage to the screw, in the same way as has been described above for the dental abutment, it is likewise impossible for what remains of the screw to be removed from the bore. The damage to the screw thus renders the final prosthesis unusable. However, the outer shape of the final prosthesis is configured uniquely for each patient, by a process that is often lengthy and difficult. The practitioner is then compelled to manufacture a new final dental prosthesis, which takes a lot of time and is expensive.
[0006] This problem is even more critical in the case of transfixed multiple dental prostheses that are intended to be received on a plurality of dental implants and, for this purpose, have a plurality of captive screws: damage to one of the screws can render the whole prosthesis unusable.
[0007] The document WO 2012/037014 A2 describes an annular ring with symmetry of revolution about a central axis, comprising two angular arc portions with respective free ends which are radially movable, in a transverse plane perpendicular to the central axis, between a retracted position and at least one protruding position, being elastically returned permanently to the protruding position. This annular ring is used to form a ratchet-type locking nut being placed in the bore of a washer. When the annular ring is received in the bore of the washer, optional tongues attached by welding allow the assembled annular ring to be retained definitively in the washer. To do so, the tongues bear permanently under the annular ring and oppose any removal of the ring from the washer by translation, and they do this irrespective of the rotation position of the annular ring with respect to the washer.
[0008] The document EP 1 060 716 A2 describes an axially compressible locking nut used in an orthopedic implant in the form of a prosthetic femoral stem.
SUMMARY OF THE INVENTION
[0009] A problem addressed by the present invention is to make available an assembly comprising a component and an axial limit stop device intended to be placed in a bore of said component in order to reliably retain an element therein, but with the axial limit stop device being able to be detached easily in order to permit the removal of the element in the event of the latter sustaining damage.
[0010] According to another aspect, the present invention aims to make available an assembly comprising a component and an axial limit stop device intended to be mounted removably in a bore of said component, said component having very small dimensions, as in the case of a dental prosthesis in particular.
[0011] To achieve these objects and others, the invention proposes an assembly according to claim 1 .
[0012] When said at least one angular portion of the axial limit stop device is in the retracted position, the axial limit stop device can be inserted by a simple movement of axial translation, along the first longitudinal axis and in the direction of the distal end of the component bore, into the first portion of the component bore. Then, by driving the axial limit stop device a little farther into the component bore in the direction of the distal end of the component bore, said at least one angular portion can penetrate into the second component bore portion and come into line with the retaining seat of the second component bore portion and engage there in the protruding position by elastic return. If an attempt is made to extract the axial limit stop device from the bore, by an axial translation movement along the first longitudinal axis and in the direction of the inlet orifice of the component bore, said at least one angular portion comes to bear against the proximal retaining face of the retaining seat and opposes this extraction. The axial limit stop device is thus able to hold an element (such as a screw and screw head) captive in the bore.
[0013] In the case where the element retained in the bore is damaged and must be withdrawn from the component, it is still possible to extract the axial limit stop device from the bore despite everything. To do so, the axial limit stop device is turned about the first longitudinal axis of the bore in such a way as to bring said at least one angular portion against the angular part of the lateral surface of the second component bore portion, which extends in the continuation of the cylindrical lateral surface of the first component bore portion. Said at least one angular portion is thus brought back to the retracted position, such that the axial limit stop device can then be extracted from the component bore, via the first component bore portion, by a simple movement of axial translation along the first longitudinal axis and in the direction of the inlet orifice of the component bore.
[0014] Advantageously, said at least one angular portion can be kept apart from the distal end of the annular ring, along the central axis, by a spacer extending parallel to the central axis. The elastic return of the angular portion to the protruding position is therefore not disturbed by the angular portion rubbing against the distal end of the annular ring.
[0015] Preferably, perpendicular to the central axis, said at least one angular portion can have a thickness that decreases from its first end toward its second free end. This effectively limits the stresses induced in the area of connection between the spacer and the angular portion by a flexion of the angular portion bringing the latter back to the retracted position. If these stresses were too high, they could end up breaking the arm and/or the angular portion near their connection, especially in the case of an axial limit stop device of small dimensions.
[0016] An indentation, allowing the annular ring to be driven in rotation about the central axis, can advantageously be formed in a proximal end face of the annular ring. The proximal end of the annular ring is in fact the part of the axial limit stop device that is most easily accessible from outside of the component.
[0017] Preferably, the indentation can comprise two diametrically opposite notches. An indentation having symmetry makes it possible to more easily turn the axial limit stop device about its central axis.
[0018] Advantageously, the axial limit stop device can have two angular portions movable in the same transverse plane.
[0019] In the case of a plurality of angular portions, provision can preferably be made that:
[0020] the second component bore portion has a plurality of retaining seats,
[0021] each retaining seat is separated from the adjacent retaining seat by an angular part of the lateral surface of the second component bore portion which extends in the continuation of the cylindrical lateral surface of the first component bore portion.
[0022] Having two or more angular portions engaged in respective retaining seats makes it possible to better retain the axial limit stop device axially in the component.
[0023] The angular parts of the lateral surface of the second component bore portion, which extend in the continuation of the cylindrical lateral surface of the first component bore portion and which separate the adjacent retaining seats, allow all of the angular portions to be brought back simultaneously to the retracted position when the axial limit stop device is driven in rotation about the central axis.
[0024] The element intended to be placed in the bore of the component with the aid of the axial limit stop device can advantageously have:
[0025] a proximal portion of the element having a cross section with dimensions less than or equal to the internal diameter of the annular ring,
[0026] a distal portion with a cross section having at least one dimension greater than the internal diameter of the annular ring but less than or equal to the diameter of the first component bore portion,
[0027] a shoulder connecting the proximal portion and distal portion of the element.
[0028] The proximal portion of the element can thus pass through the axial limit stop device in order to protrude from the bore of the component, while the distal portion of the element bears axially along the shoulder against the axial limit stop device, in order to be retained in the bore of the component.
[0029] Preferably, the element intended to be placed in the cylindrical bore of the component can be a screw, of which the head constitutes the distal portion of the element and of which the threaded shank constitutes the proximal portion of the element.
[0030] To make it easier for the assembly according to the invention to be put together by inserting the axial limit stop device into the bore of the component, it is possible to use a mounting tool in which the following provisions can be made:
[0031] a tubular sleeve with a central bore extends along a second longitudinal axis between a distal orifice and a proximal orifice,
[0032] the central bore of the tubular sleeve has a tubular sleeve distal bore portion, extending from the distal orifice, a tubular sleeve intermediate bore portion, following on from the tubular sleeve distal bore portion and extending toward the proximal orifice, and a tubular sleeve proximal bore portion following on from the tubular sleeve intermediate bore portion and extending as far as the proximal orifice,
[0033] the tubular sleeve intermediate bore portion has a circular cross section with a diameter equal to or slightly greater than the external diameter of the annular ring,
[0034] the tubular sleeve distal bore portion has at least one retaining seat which extends radially with respect to the second longitudinal axis out from the volume of the cylinder continuing the cylindrical surface of the tubular sleeve intermediate bore portion, said retaining seat being able to receive said at least one angular portion of the axial limit stop device in the protruding position,
[0035] the retaining seat has a proximal retaining face extending along a transverse plane substantially perpendicular to the second longitudinal axis and connecting to the cylindrical lateral wall of the tubular sleeve intermediate bore portion,
[0036] the tubular sleeve distal bore portion has at least one angular part with a lateral surface extending in the continuation of the cylindrical lateral surface of the tubular sleeve intermediate bore portion.
[0037] A mounting tool of this kind proves particularly useful when the axial limit stop device has very small dimensions, as is especially the case when it is used to retain an element such as a screw in a dental prosthesis.
[0038] To insert the axial limit stop device into the bore of the component, it is first of all inserted into the tubular sleeve distal bore portion. Said at least one angular portion, then in the protruding position, is engaged in said at least one retaining seat provided in the tubular sleeve distal bore portion. By turning the axial limit stop device about the central axis, said at least one angular portion is then brought into line with said at least one angular part of the lateral surface extending in the continuation of the cylindrical lateral surface of the tubular sleeve proximal bore portion. The angular portion is thus brought back to the retracted position. The distal orifice of the tubular sleeve is then brought in immediate proximity to the inlet orifice of the component bore. The axial limit stop device, with its angular portion in the retracted position, is then pushed out of the tubular sleeve distal bore portion in order to be engaged in the first component bore portion until the angular portion of the axial limit stop device penetrates into the second component bore portion and comes into line with the retaining seat of the second component bore portion in order to engage there in the protruding position by elastic return.
[0039] To push the axial limit stop device out of the tubular sleeve distal bore portion, a longitudinal shaft can be passed through the tubular sleeve from the direction of the proximal orifice thereof.
[0040] The element intended to be retained in the component bore can be first engaged in the component bore before the axial limit stop device is engaged there. Alternatively, the element intended to be retained in the component bore can be introduced into the component bore at the same time as the axial limit stop device.
[0041] Preferably, provision can be made that:
[0042] the mounting tool has a longitudinal shaft extending along a third longitudinal axis, with a distal portion having an outer circular cross section of diameter substantially equal to the diameter of the tubular sleeve intermediate bore portion,
[0043] the distal portion of the longitudinal shaft extends along the third longitudinal axis by a length greater than the sum of the lengths of the tubular sleeve intermediate bore portion and tubular sleeve distal bore portion along the second longitudinal axis,
[0044] the distal portion of the longitudinal shaft has, at a free end, a distal face intended to bear against the proximal end of the annular ring,
[0045] the distal face of the distal portion of the longitudinal shaft has raised areas able to cooperate with the indentation formed in the face of the proximal end of the annular ring in order to drive the annular ring in rotation about its central axis.
[0046] The longitudinal shaft thus serves simultaneously:
[0047] to push the axial limit stop device out of the tubular sleeve distal bore portion in order to engage the axial limit stop device in the first component bore portion,
[0048] to turn the axial limit stop device about the central axis in the tubular sleeve distal bore portion in order to bring the angular portion to the retracted position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] Other subjects, features and advantages of the present invention will become clear from the following description of particular embodiments, with reference being made to the attached figures in which:
[0050] FIG. 1 is a perspective view of an example of an axial limit stop device intended to be used in a particular embodiment of the assembly according to the invention;
[0051] FIG. 2 is another perspective view of the axial limit stop device of FIG. 1 , seen in a different direction from that of FIG. 1 ;
[0052] FIG. 3 is a bottom view of the axial limit stop device of FIG. 1 ;
[0053] FIG. 4 is a top view of the axial limit stop device of FIG. 1 ;
[0054] FIG. 5 is a bottom view, in cross section, of the axial limit stop device of FIG. 1 ;
[0055] FIG. 6 is a perspective view of a component in the form of a transfixed multiple dental prosthesis, supported by a plurality of dental implants;
[0056] FIG. 7 is a top view of the transfixed multiple dental prosthesis of FIG. 6 ;
[0057] FIG. 8 is a detailed cross-sectional view, on a section plane A-A, of a particular embodiment of the assembly according to the invention, comprising the component from FIG. 6 , in the form of a transfixed multiple dental prosthesis, in a bore of which an element is retained by the axial limit stop device of FIG. 1 ;
[0058] FIG. 9 is another detailed cross-sectional view of the assembly from FIG. 8 , on a first variant of a dental implant, seen in a section plane B-B perpendicular to the section plane A-A of FIG. 8 ;
[0059] FIG. 10 is a detailed cross-sectional view of the bore of the component from FIG. 6 , in the form of a transfixed multiple dental prosthesis, seen in a section plane C-C perpendicular to the section planes A-A and B-B of FIGS. 8 and 9 ;
[0060] FIG. 11 is a cross-sectional side view of the element retained in the bore of the component, in the form of a transfixed multiple dental prosthesis, from FIGS. 8 and 9 ;
[0061] FIG. 12 is a side view of the element from FIG. 11 ;
[0062] FIG. 13 is a perspective view of the element from FIG. 11 ;
[0063] FIG. 14 is a cross-sectional view of a tubular sleeve of a mounting tool;
[0064] FIG. 15 is a view of the distal end of the tubular sleeve from FIG. 14 ;
[0065] FIG. 16 is a side view of the tubular sleeve from FIG. 14 , of an axial limit stop device from FIG. 1 , and of a longitudinal shaft of the mounting tool;
[0066] FIG. 17 is another side view of the elements of FIG. 16 , seen in a direction perpendicular to that of FIG. 16 ;
[0067] FIGS. 18 and 19 are detailed cross-sectional side views illustrating the cooperation of the elements of FIG. 16 ;
[0068] FIGS. 20 and 21 are perspective views illustrating the use of the tubular sleeve from FIG. 14 and of the longitudinal shaft from FIG. 16 for fitting an axial limit stop device from FIG. 1 in a bore of the component from FIG. 6 , in the form of a transfixed multiple dental prosthesis; and
[0069] FIG. 22 is another detailed cross-sectional view of the assembly from FIG. 8 , on a second variant of a dental implant, seen in a section plane B-B perpendicular to the section plane A-A of FIG. 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0070] FIGS. 1 to 5 depict an example of an axial limit stop device 1 intended for the manufacture of a particular embodiment of an assembly 100 according to the invention (said assembly 100 can be seen more particularly in FIGS. 8, 9 and 22 ). The axial limit stop device 1 is in one piece and comprises an annular ring 2 which has symmetry of revolution about a central axis I-I and which extends along the central axis I-I between a proximal end 2 a and a distal end 2 b . Two angular portions 3 and 4 develop in an arc between first ends 3 a and 4 a , connected to the distal end 2 b of the annular ring 2 , and a second free end 3 b and 4 b . The angular portions 3 and 4 are in part radially movable by deformation, starting from their first ends 3 a and 4 a , in one and the same transverse plane P 1 perpendicular to the central axis I-I, between a retracted position (illustrated in broken lines in FIG. 4 ) and at least one protruding position (illustrated in solid lines in FIGS. 1 to 5 ), by being elastically returned permanently to the protruding position.
[0071] As is illustrated in FIG. 4 in broken lines, in the retracted position, the angular portions 3 and 4 are included within the volume of a cylinder C 1 continuing the outer cylindrical surface of the annular ring 2 . In the protruding position, the free ends 3 b and 4 b of the angular portions 3 and 4 protrude beyond the volume of the cylinder C 1 continuing the outer cylindrical surface of the annular ring 2 .
[0072] It will be seen more particularly in FIGS. 1 and 2 that the first ends 3 a and 4 a of the angular portions 3 and 4 and the distal end 2 b of the annular ring 2 are connected by spacers 5 and 6 extending parallel to the central axis I-I. The angular portions 3 and 4 are thus kept apart from the distal end 2 b of the annular ring 2 along the central axis I-I.
[0073] It will be seen more particularly in FIG. 5 that, perpendicular to the central axis I-I, the angular portions 3 and 4 have a thickness which decreases from the first ends 3 a and 4 a toward the second free ends 3 b and 4 b . More precisely, the angular portions 3 and 4 have, near their first ends 3 a and 4 a , a radial thickness e 1 that is greater than the radial thickness e 2 near their second free ends 3 b and 4 b . The thickness of the angular portions 3 and 4 decreases progressively from e 1 to e 2 .
[0074] It will be seen more particularly in FIGS. 1 to 3 that the axial limit stop device 1 comprises an indentation 7 for driving in rotation, allowing the annular ring 2 to be driven in rotation about the central axis I-I. This indentation 7 is formed in a face 8 of the proximal end 2 a of the annular ring 2 . In more detail, the indentation 7 has two diametrically opposite notches 9 and 10 .
[0075] The axial limit stop device 1 in FIGS. 1 to 5 is intended to be placed in the bore of a component 11 in order to retain an element 14 therein.
[0076] In the field of dentistry, the axial limit stop device 1 is intended to be placed in a bore 17 formed in a component in the shape of a dental prosthesis 11 , such as the transfixed multiple dental prosthesis 11 illustrated in FIGS. 6 and 7 , in order to retain therein a screw 14 such as the one illustrated in FIGS. 11 to 13 . The transfixed multiple dental prosthesis 11 extends in a plane C-C along a curved prosthetic corridor CP.
[0077] The transfixed multiple dental prosthesis 11 illustrated in FIGS. 6 and 7 is intended to be attached to and fixed on two dental implants 12 and 13 , which are themselves intended to be received in the maxillary or mandibular bone of a patient. To do this, the transfixed multiple dental prosthesis 11 is fixed on the implants 12 and 13 by way of screws 14 such as those illustrated in FIGS. 11 to 13 . The screws 14 are accessible by a screwing tool via access wells 15 and 16 which communicate with bores formed in the transfixed multiple dental prosthesis 11 . This is revealed more particularly by FIGS. 8 and 9 , which are cross-sectional views seen, respectively, along the section planes A-A and B-B illustrated in FIG. 7 .
[0078] In FIGS. 8 and 9 , it will be seen that the transfixed multiple dental prosthesis 11 has a bore 17 extending along a first longitudinal axis II-II between a proximal end 17 a , with inlet orifice 18 , and a distal end 17 b . The axial limit stop device 1 is received in the component bore 17 with its central axis I-I coaxial with the first longitudinal axis II-II. The axial limit stop device 1 and the component 11 , which is here in the form of a transfixed multiple dental prosthesis, form an assembly 100 .
[0079] Said component bore 17 has a first component bore portion T 171 extending from the inlet orifice 18 of the component bore 17 , and a second component bore portion T 172 following on from the first component bore portion T 171 and extending toward the distal end 17 b of the component bore 17 . The component bore 17 additionally has a third component bore T 173 following on from the second component bore portion T 172 and extending as far as the distal end 17 b of the component bore 17 .
[0080] The first component bore portion T 171 has a circular cross section with a diameter D 1 equal to or slightly greater than the external diameter D 2 of the annular ring 2 .
[0081] The second component bore portion T 172 has two retaining seats 19 and 20 which extend radially with respect to the first longitudinal axis II-II out from the volume of the cylinder C 2 continuing the cylindrical surface of the first component bore portion T 171 . The retaining seats 19 and 20 are able to receive the angular portions 3 and 4 of the axial limit stop device 1 in the protruding position. The shape of the retaining seats 19 and 20 can be seen more particularly in FIG. 10 , which is a cross-sectional view along the section plane C-C in FIG. 8 .
[0082] In FIGS. 8 and 10 , it will be seen that the retaining seats 19 and 20 have proximal retaining faces 21 and 22 extending along a transverse plane P 2 substantially perpendicular to the first longitudinal axis II-II. In other words, the proximal retaining faces 21 and 22 extend in the transverse plane P 2 substantially parallel to the section plane C-C illustrated in FIG. 8 . The proximal retaining faces 21 and 22 are connected to the cylindrical lateral wall T 171 a of the first component bore portion T 171 .
[0083] The second component bore portion T 172 has two angular parts 23 and 24 of the lateral surface T 172 a extending in the continuation of the cylindrical lateral surface T 171 a of the first component bore portion T 171 . The angular parts 23 and 24 are included within the diametric lines indicated by broken lines in FIG. 10 . The angular parts 23 and 24 separate the adjacent retaining seats 19 and 20 .
[0084] The retaining seats 19 and 20 develop radially with respect to the first longitudinal axis II-II and substantially along the prosthetic corridor CP. There is therefore more space available radially for drilling the retaining seats 19 and 20 and thereby increasing the axial retention of the axial limit stop device 1 .
[0085] An element intended to be placed in the bore 17 of the component (transfixed multiple dental prosthesis 11 ) is illustrated more particularly in FIGS. 11 to 13 . This element is a screw 14 , and therefore it will be referred to below synonymously as element 14 or screw 14 . The element 14 has:
[0086] a proximal portion 25 with a cross section having dimensions less than or equal to the internal diameter D 3 of the annular ring 2 ,
[0087] a distal portion 26 with a cross section having at least one dimension greater than the internal diameter D 3 of the annular ring 2 but less than or equal to the diameter D 1 of the first component bore portion T 171 ,
[0088] a shoulder 27 joining the proximal portion 25 of the element and the distal portion 26 of the element.
[0089] As has already been explained, the element illustrated in FIGS. 11 to 13 is a screw 14 , of which the head 28 comprises the distal portion 26 of the element, and of which the threaded shank 29 constitutes at least in part the proximal portion 25 of the element.
[0090] As is illustrated in FIGS. 8 and 9 , when the axial limit stop device 1 is engaged in the bore 17 with its angular portions 3 and 4 engaged in the retaining seats 19 and 20 ( FIG. 8 ), the distal element portion 26 of the screw 14 bears on the first ends 3 a and 4 a of the angular portions 3 and 4 along the shoulder 27 . The axial bearing of the shoulder 27 against the first ends 3 a and 4 a and the axial bearing of the second free ends 3 b and 4 b against the proximal faces 21 and 22 allow the screw 14 to be retained axially in the bore 17 of the component, which is here represented by the transfixed multiple dental prosthesis 11 .
[0091] The screw 14 can then be manipulated in turn, by driving it in rotation about the central axis I-I by means of a screwing tool engaged in the access well 15 , in order to fix the transfixed multiple dental prosthesis 11 on the dental implant 12 .
[0092] If the screw 14 has been damaged by application of an excessive rotational torque or by any other means, it is necessary that it can be extracted from the bore 17 .
[0093] To do this, the axial limit stop device 1 is turned about the first longitudinal axis II-II (by means of the notches 9 and 10 ) in such a way as to bring the angular portions 3 and 4 against the angular parts 23 and 24 of the lateral surface T 172 a of the second component bore portion T 172 . The angular portions 3 and 4 are thus brought back to the retracted position, such that they no longer protrude radially in the retaining seats 19 and 20 . The axial limit stop device 1 can then be extracted from the component bore 17 , via the first component bore portion T 171 , by a simple movement of axial translation along the first longitudinal axis II-II and in the direction of the orifice 18 of the component bore 17 .
[0094] FIGS. 14 to 17 illustrate a mounting tool 30 for mounting an axial limit stop device 1 in the bore 17 of the transfixed multiple dental prosthesis 11 . As will be seen more particularly from FIGS. 14 and 15 , the mounting tool 30 has a tubular sleeve 31 with a central bore 32 extending along a second longitudinal axis III-III between a distal orifice 33 and a proximal orifice 34 . It will additionally be seen that:
[0095] the central bore 32 of the tubular sleeve 31 has a tubular sleeve distal bore portion T 310 extending from the distal orifice 33 , a tubular sleeve intermediate bore portion T 311 following on from the tubular sleeve distal bore portion T 310 and extending toward the proximal orifice 34 , and a tubular sleeve proximal bore portion T 312 following on from the tubular sleeve intermediate bore portion T 311 and extending as far as the proximal orifice 34 ,
[0096] the tubular sleeve intermediate bore portion T 311 has a circular cross section of diameter D 4 equal to or slightly greater than the external diameter D 2 of the annular ring 2 ,
[0097] the tubular sleeve distal bore portion T 310 has two retaining seats 35 and 36 which extend radially with respect to the second longitudinal axis III-III out from the volume of the cylinder C 3 continuing the cylindrical surface of the tubular sleeve intermediate bore portion T 311 , the retaining seats 35 and 36 being able to receive the angular portions 3 and 4 of the axial limit stop device 1 in the protruding position.
[0098] The retaining seats 35 and 36 each have a proximal retaining face 37 or 38 , respectively, extending along a transverse plane P 3 substantially perpendicular to the second longitudinal axis III-III and connecting to the cylindrical lateral wall of the tubular sleeve intermediate bore portion T 311 .
[0099] The tubular sleeve distal bore portion T 310 has two angular parts 39 and 40 of the lateral surface extending in the continuation of the cylindrical lateral surface of the tubular sleeve intermediate bore portion T 311 . The angular parts 39 and 40 are included within the diametric lines indicated by broken lines in FIG. 15 . Each retaining seat 35 and 36 is separated from the adjacent retaining seat 35 or 36 by an angular part 39 or 40 .
[0100] It will be seen more particularly in FIGS. 16 and 17 that the mounting tool 30 likewise has a longitudinal shaft 41 extending along a third longitudinal axis IV-IV, with a distal portion T 410 having a circular outer cross section of diameter D 5 substantially equal to the diameter D 4 of the tubular sleeve intermediate bore portion T 311 . The distal portion T 410 of the longitudinal shaft extends along the third longitudinal axis IV-IV by a length L 1 greater than the sum of the lengths (along the second longitudinal axis III-III) of the tubular sleeve intermediate bore portion T 311 and of the tubular sleeve distal bore portion T 310 . The engagement of the distal portion T 410 of the longitudinal shaft in the tubular sleeve intermediate bore portion T 311 and the tubular sleeve distal bore portion T 310 can thus eject from the tubular sleeve 31 an axial limit stop device 1 which would be inserted in the tubular sleeve distal bore portion T 310 .
[0101] To move the axial limit stop device 1 in rotation with respect to the tubular sleeve 31 about the second longitudinal axis III-III, it will be seen that:
[0102] the distal portion. T 410 of the longitudinal shaft has, at a free end T 410 a , a distal face 42 intended to bear against the proximal end 2 a of the annular ring 2 ,
[0103] the distal face 42 of the distal portion T 410 of the longitudinal shaft has raised areas, specifically two tongues 43 and 44 , which are able to cooperate with the indentation 7 formed in the face 8 of the proximal end 2 a of the annular ring 2 (by engaging in the notches 9 and 10 ) in order to drive the annular ring 2 in rotation about its central axis I-I with respect to the tubular sleeve 31 . A use of the mounting tool 30 to insert and fix an axial limit stop device 1 in the bore 17 of a transfixed multiple dental prosthesis 11 will be explained below with the aid of FIGS. 16 to 21 .
[0104] The axial limit stop device 1 is first of all inserted with a translation movement, illustrated by the arrow 45 in FIGS. 16 and 17 , into the tubular sleeve distal bore portion T 310 . During this insertion, the angular portions 3 and 4 , in the protruding position, are received in the retaining seats 35 and 36 while the annular ring 2 is received in the tubular sleeve intermediate bore portion T 311 .
[0105] After this assembling of the tubular sleeve 31 and of the axial limit stop device 1 , the longitudinal shaft 41 is inserted into the central bore 32 of the tubular sleeve 31 from the proximal orifice 34 toward the distal orifice 33 , according to the movement illustrated by the arrow 46 in FIGS. 18 and 19 .
[0106] The longitudinal shaft 41 is inserted into the central bore 32 until the tongues 43 and 44 engage in the notches 9 and 10 , as is illustrated in FIG. 19 .
[0107] The practitioner then moves the longitudinal shaft 41 in rotation about the second longitudinal axis III-III (coinciding with the central axis I-I and the third longitudinal axis IV-IV), in such a way as to bring the angular portions 3 and 4 into line with the angular parts 39 and 40 of the tubular sleeve distal bore portion T 310 (movement illustrated by the arrow 47 in FIG. 19 ). The angular portions 3 and 4 are thus brought back to a retracted position.
[0108] The assembly formed by the axial limit stop device 1 (with its angular portions 3 and 4 in the retracted position), the tubular sleeve 31 and the longitudinal shaft 41 is then arranged with the central axis I-I, the second longitudinal axis III-III and the third longitudinal axis IV-IV coinciding with the first longitudinal axis II-II as illustrated in FIG. 20 .
[0109] The assembly formed by the axial limit stop device 1 , the tubular sleeve 31 and the longitudinal shaft 41 is then moved until the distal orifice 33 of the tubular sleeve 31 comes into contact with the inlet orifice 18 of the component bore 17 as illustrated in FIG. 21 . The longitudinal shaft 41 is then moved with respect to the tubular sleeve 31 according to the axial translation movement illustrated by the arrow 48 . The longitudinal shaft 41 then pushes the axial limit stop device 1 (with its angular portions 3 and 4 in the retracted position) through the first component bore portion T 171 until the angular portions 3 and 4 come into line (axially) with the second component bore portion T 172 . At that moment, if the angular portions 3 and 4 are likewise located in line (radially) with the retaining seats 19 and 20 , they are elastically returned to the protruding position and penetrate radially into the retaining seats 19 and 20 . The axial limit stop device 1 is thus duly installed in the bore 17 , as illustrated in FIGS. 8 and 9 . In the case where the angular portions 3 and 4 are located in line with the angular parts 23 and 24 and thus remain in the retracted position in the second component bore portion T 172 , a rotation movement illustrated by the arrow 49 can be applied to the axial limit stop device 1 by the longitudinal shaft 41 in such a way as to bring the angular parts 3 and 4 into line with the retaining seats 19 and 20 and permit the movement of the angular portions to the protruding position.
[0110] The screw 14 can be installed in the bore 17 prior to the insertion of the axial limit stop device 1 into the bore 17 . Alternatively, before the axial limit stop device 1 has been inserted into the tubular sleeve distal bore portion T 310 , it is also possible to insert the screw 14 through the axial limit stop device 1 until the shoulder 27 comes to bear on the angular portions 3 and 4 . It is then the subassembly formed by the axial limit stop device 1 and the screw 14 that is simultaneously pushed axially into the bore 17 during the relative translation movement, illustrated by the arrow 48 in FIG. 21 , between the tubular sleeve 31 and the longitudinal shaft 41 .
[0111] To disassemble the axial limit stop device 1 , the latter is moved in rotation about the central axis I-I until the angular portions 3 and 4 are brought back to the retracted position by cooperation with the angular parts 23 and 24 of the component bore 17 . This can be accomplished by using the longitudinal shaft 41 and its tongues 43 and 44 .
[0112] The axial limit stop device 1 (and the screw 14 ) can then be pushed in the direction of the inlet orifice 18 out of the bore 17 by a pusher tool (a rod for example) bearing against the axial limit stop device 1 (and/or the screw 14 ) by passing through the access well 15 .
[0113] In a first variant illustrated in FIG. 9 , the dental implant 12 is in just one piece, and its upper end 12 a is intended to pass at least partially through the mucosa.
[0114] In a second variant illustrated in FIG. 22 , the dental implant 12 is in two pieces, being composed of an osseous anchor 120 and of a transmucosal extension 121 . The transmucosal extension 121 has an upper end 121 a intended to pass at least partially through the mucosa.
[0115] The present invention is not limited to the embodiments that have been explicitly described, and instead it includes the different variants and generalizations contained within the scope of the attached claims.
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Assembly comprising a component and a one-piece axial limit stop device ( 1 ) intended to be placed in a bore of said component in order to retain an element therein, comprising an annular ring ( 2 ) with symmetry of revolution about a central axis (I-I), and comprising at least one angular portion ( 3, 4 ) rigidly connected to the annular ring ( 2 ), developing in an arc between a first end ( 3 a, 4 a ), joined to the distal end ( 2 b ) of the annular ring ( 2 ), and a second, free end ( 3 b, 4 b ). The angular portion ( 3, 4 ) is in part movable from its first end ( 3 a, 4 a ), in a transverse plane perpendicular to the central axis (I-I), between a retracted position and at least one protruding position, being elastically returned permanently to the protruding position. In the retracted position, the angular portion ( 3, 4 ) is included within the volume of a cylinder continuing the outer cylindrical surface of the annular ring ( 2 ). In the protruding position, the free end ( 3 b, 4 b ) of the angular portion ( 3, 4 ) extends radially beyond the volume of the cylinder continuing the outer cylindrical surface of the annular ring ( 2 ). The component bore has a specific inner geometry allowing the axial limit stop device ( 1 ) to be easily attached and reliably fixed, while at the same time allowing easy detachment and extraction of the axial limit stop device ( 1 ) in order to permit the removal of the element in the event of the latter sustaining damage.
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FIELD
The present application relates to variable displacement engines coupled in hybrid powetrains of vehicles.
BACKGROUND AND SUMMARY
Variable displacement engine have been used where one or more cylinder is deactivated (e.g., by closing intake and exhaust valves). In this way, increased fuel economy can be obtained during engine operating conditions that do not require full cylinder operation.
Vehicle system with variable displacement capabilities have also been described having hybrid powertrains. For example, US 2004/0035113 describes an approach where cylinder deactivation operation can be extended by providing additional torque from an electric motor. Further, activation/deactivation transitions are described using changes in throttle position with motor assist require before, during, and after the transition.
The inventors herein have recognized a disadvantage with such an approach. In particular, US 2004/0035113 generally requires consistent application of torque from the motor during cylinder deactivation conditions; however, this can continually drain the battery, especially during vehicle towing conditions or during long vehicle climbs. Furthermore, the inventors herein have also recognized that the transitions according to US 2004/0035113 may also result in degraded vehicle feel since a substantially constant motor torque is used, relying on rapid throttle changes to handle the torque disturbance. Specifically, even rapid throttle changes may be inadequate to provide acceptable vibration and drive feel during the transition.
In one example, at least some of the above disadvantages may be overcome by a vehicle system, comprising: a engine capable of disabling and enabling at least one cylinder; a motor coupled to said engine capable of absorbing torque and providing torque; and a controller for disabling and enabling said at least one cylinder, and during at least one of disabling and enabling, varying torque of said motor to compensate for transient changes in engine output torque caused by said one of disabling and enabling.
In this way, it may be possible to provide improved torque control during variation in the number of cylinders carrying out combustion. Further, such transitions may be performed with less energy loss due to spark retard. Further still, such transitions may be performed to increase stored energy. Finally, such transitions may be performed based on battery status to provide improved hybrid vehicle performance.
Note that there may be various approaches to disabling cylinders, including disabling intake and exhaust valves, disabling fuel injection (without disabling valves), or others.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an engine in an example hybrid powertrain;
FIG. 2 is a schematic diagram of an engine, intake system, and exhaust system;
FIGS. 3–6 are graphs showing example operation according to various example embodiments; and
FIGS. 7–8 are high level flowcharts showing an example embodiment of operation.
DETAILED DESCRIPTION
The present disclosure relates to electric vehicles and, more particularly, hybrid electric vehicles (HEVs). FIG. 1 demonstrates just one possible configuration, specifically a parallel/series hybrid electric vehicle (split) configuration.
In an HEV, a planetary gear set 20 mechanically couples a carrier gear 22 to an engine 24 via a one way clutch 26 . The planetary gear set 20 also mechanically couples a sun gear 28 to a generator motor 30 and a ring (output) gear 32 . The generator motor 30 also mechanically links to a generator brake 34 and is electrically linked to a battery 36 . A traction motor 38 is mechanically coupled to the ring gear 32 of the planetary gear set 20 via a second gear set 40 and is electrically linked to the battery 36 . The ring gear 32 of the planetary gear set 20 and the traction motor 38 are mechanically coupled to drive wheels 42 via an output shaft 44 .
The planetary gear set 20 , splits the engine 24 output energy into a series path from the engine 24 to the generator motor 30 and a parallel path from the engine 24 to the drive wheels 42 . Engine 24 speed can be controlled by varying the split to the series path while maintaining the mechanical connection through the parallel path. The traction motor 38 augments the engine 24 power to the drive wheels 42 on the parallel path through the second gear set 40 . The traction motor 38 also provides the opportunity to use energy directly from the series path, essentially running off power created by the generator motor 30 . This reduces losses associated with converting energy into and out of chemical energy in the battery 36 and allows all engine 24 energy, minus conversion losses, to reach the drive wheels 42 .
A vehicle system controller (VSC) 46 controls many components in this HEV configuration by connecting to each component's controller. An engine control unit (ECU) 48 connects to the Engine 24 via a hardwire interface (see further details in FIG. 2 ). In one example, the ECU 48 and VSC 46 can be placed in the same unit, but are actually separate controllers. Alternatively, they may be the same controller, or placed in separate units. The VSC 46 communicates with the ECU 48 , as well as a battery control unit (BCU) 45 and a transaxle management unit (TMU) 49 through a communication network such as a controller area network (CAN) 33 . The BCU 45 connects to the battery 36 via a hardware interface. The TMU 52 controls the generator motor 30 and the traction motor 38 via a hardwire interface. The control units 46 , 48 , 45 and 49 , and controller area network 33 can include one or more microprocessors, computers, or central processing units; one or more computer readable storage devices; one or more memory management units; and one or more input/output devices for communicating with various sensors, actuators and control circuits.
FIG. 2 shows an example engine and exhaust system that may be used as engine 24 . Internal combustion engine 24 , comprising a plurality of cylinders, one cylinder of which is shown in FIG. 2 , is controlled by electronic engine controller 48 . Engine 24 includes combustion chamber 29 and cylinder walls 31 with piston 35 positioned therein and connected to crankshaft 39 . Combustion chamber 29 is shown communicating with intake manifold 43 and exhaust manifold 47 via respective intake valve 52 an exhaust valve 54 . Each intake and exhaust valve is operated by an electromechanically controlled valve coil and armature assembly 53 . Armature temperature is determined by temperature sensor 51 . Valve position is determined by position sensor 50 . In an alternative example, each of valves actuators for valves 52 and 54 has a position sensor and a temperature sensor. In an alternative embodiment, cam actuated valves may be used with or without variable cam timing or variable valve lift.
Intake manifold 43 is also shown having fuel injector 65 coupled thereto for delivering liquid fuel in proportion to the pulse width of signal FPW from controller 48 . Fuel is delivered to fuel injector 65 by fuel system (not shown) including a fuel tank, fuel pump, and fuel rail (not shown). Alternatively, the engine may be configured such that the fuel is injected directly into the engine cylinder, which is known to those skilled in the art as direct injection. In addition, intake manifold 43 is shown communicating with optional electronic throttle 125 .
Distributorless ignition system 88 provides ignition spark to combustion chamber 30 via spark plug 92 in response to controller 48 . Universal Exhaust Gas Oxygen (UEGO) sensor 76 is shown coupled to exhaust manifold 47 upstream of catalytic converter 70 . Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 76 . Two-state exhaust gas oxygen sensor 98 is shown coupled to exhaust manifold 47 downstream of catalytic converter 70 . Alternatively, sensor 98 can also be a UEGO sensor. Catalytic converter temperature is measured by temperature sensor 77 , and/or estimated based on operating conditions such as engine speed, load, air temperature, engine temperature, and/or airflow, or combinations thereof. Converter 70 can include multiple catalyst bricks, in one example. In another example, multiple emission control devices, each with multiple bricks, can be used. Converter 70 can be a three-way type catalyst in one example.
Controller 48 is shown in FIG. 2 as a conventional microcomputer including: microprocessor unit 102 , input/output ports 104 , and read-only memory 106 , random access memory 108 , 110 keep alive memory, and a conventional data bus. Controller 48 is shown receiving various signals from sensors coupled to engine 24 , in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a position sensor 119 coupled to a accelerator pedal; a measurement of engine manifold pressure (MAP) from pressure sensor 122 coupled to intake manifold 44 ; a measurement (ACT) of engine air amount temperature or manifold temperature from temperature sensor 117 ; and a engine position sensor from a Hall effect sensor 118 sensing crankshaft 40 position. In one aspect of the present description, engine position sensor 118 produces a predetermined number of equally spaced pulses every revolution of the crankshaft from which engine speed (RPM) can be determined.
In an alternative embodiment, a direct injection type engine can be used where injector 66 is positioned in combustion chamber 29 , either in the cylinder head similar to spark plug 92 , or on the side of the combustion chamber.
In one example, engine 24 can operate in a variable displacement mode where one or more cylinder operates with deactivated valves. For example, both the intake and exhaust valves can be held closed for one or more cycles of the cylinder or engine. In the example of cam actuated valves, a deactivation mechanism may be used which is electro-hydraulically controlled. For example, deactivators may be used in lifters or in portions of an overhead cam assembly. Alternatively, cylinder deactivation may include continuing valve operation and disabling fuel injection (e.g., fuel-cut operation).
As noted above, any number of different engine types may be used. While the description below relates to a V-8 engine capable of deactivating four cylinders (e.g., 4 cylinder valve-deactivation mode and 8 cylinder non-valve-deactivation mode), various other engine configurations may be used. The examples described herein equally apply to an engine with 4, 6, 10, 12 or other number of cylinders. Additionally, these examples can easily be extended to systems where multiple valve deactivation modes are available (i.e. 2, 4, or 6 cylinder operation for a V8 engine).
One approach to managing mode transitions utilizes coordination of ignition timing retard and throttle position. When running in valve deactivation mode, the manifold pressure is increased to maintain substantially equivalent torque. Since throttle position may not immediately change airflow into the VDE engine (due to throttle response lag and manifold filling), spark retard may be used to reduce engine torque while increasing manifold pressure to the new desired set point (see FIG. 3 ). While spark is one variable that may be used to reduce engine output of oncoming (or off going) cylinders, any combination of spark, enleanment, or injector cutout could be used to reduce torque during this transition. As can be seen from FIG. 3 , such an approach may result in a energy loss (and thereby degrade fuel economy) during these transitions. In other words, spark retard is able to rapidly reduce torque, but results in inefficient use of the injected fuel. Note that FIG. 3 shows spark retard/advance from a nominal value, which may be maximum torque for best torque (MBT).
Another approach to managing mode transitions incorporates adjustment a secondary torque source, such as a motor used in a hybrid powertrain. Various other types of secondary torque sources may be used, such as, for example, a starter-alternator or transaxle motor. In this example, the secondary torque source provides another option for managing engine torque during VDE transitions. Torque adjustments (to reduce or increase torque) can be achieved via the secondary torque source instead of, or in addition to, spark retard. In this way, numerous options are available to manage the transition in the number of active cylinders. These include:
Absorbing torque in the secondary torque source before deactivating activated cylinders; Absorbing torque in the secondary torque source after activating deactivated cylinders; Providing torque in the secondary torque source after deactivating activated cylinders; Providing torque in the secondary torque source before activating deactivated cylinders; and/or Combinations thereof, including varying the levels of absorbing/providing torque during any one transition (or between multiple transitions), such as based on battery state of charge and/or other operating conditions.
By using any one or more of the above options, it can be possible to manage energy flow while providing the desired engine torque control during VDE mode transitions.
Referring now to FIGS. 4–6 , various examples are shown illustrating different mode transition control strategies (4->8 and 8->4 transitions with energy recovery/negative secondary torque and energy usage/positive secondary torque). In these examples, an electric motor is given as an example secondary torque source. FIG. 4 shows an example in which energy is absorbed through the electric motor during both the activation and deactivation of cylinders. The absorbed energy may then be available to be stored, such as in a battery. In particular, FIG. 4 shows that the increased engine output (from increasing manifold pressure via, e.g., adjustment of throttle position) during 8-cylinder operation can be used absorbed by the motor/battery electrical system. Then, when disabling cylinders (and thus removing the increased engine output), the motor/battery system can likewise be adjusted to reduce its energy storage. The enablement transition follows a similar approach in which energy is stored via the motor/battery system during the decrease in manifold pressure. In this way, engine torque during the transition can be controlled. While not shown in this example, further adjustments to ignition timing may be used, if desired.
While the approach of FIG. 4 provides efficient use of the temporary engine output increase, additional factors can determine the amount of motor torque absorption/storage, such as, for example, battery state of charge (SOC). For example, energy absorption via the motor may be advantageous during low battery state of charge conditions. Also, as noted above, ignition timing adjustments may be used, some combination of negative motor torque and spark retard may be used, or positive motor torque may be used (see below), or combinations thereof.
Referring now to FIG. 5 , an example transition is shown in which energy may be provided through the electric motor during both the activation and deactivation of cylinders. In this example, the torque deficiency that may otherwise be present due to the increasing (or decreasing) of manifold pressure is made up through the motor. In other words, FIG. 5 shows that the engine output torque deficiency during 4-cylinder operation can be compensated for by the motor/battery electrical system. In this way, engine torque during the transition can be controlled. Such an approach may be used when there is a surplus of charge (e.g., high battery SOC), or when there may be motor torque limitations (e.g. maximum negative torque limits or dynamic response limits). Also, while not shown in this example, further adjustments to ignition timing may be used, if desired. Such an approach may be particularly useful in a starter-alternator/VDE combination where the starter-alternator may have less torque capability and less energy storage capability within the battery.
Note that other parameters may also influence whether the motor is used to supply or absorb energy, whether ignition timing retard is used, or whether to use the motor at all, or whether to select from combinations thereof. For example, ignition timing retard may affect catalyst temperature and emissions, and thus such factors may be used to select the transition compensation strategy. For example, in FIG. 6 , the motor both supplies and absorbs torque during the transition. The amount of supply/absorption can be adjusted (based on operating conditions such as battery state of charge, motor torque capability, desired engine torque, etc.), or can be selected to be energy neutral. An energy neutral transition can be one in which the amount of energy supplied by the motor approximately equals the amount of energy stored. Alternatively, by changing the actual VDE transition point relative to the transition of the manifold absolute pressure (MAP) from one mode to the other, it can be possible to adjust the net energy flow from full absorption, to neutral, to full torque supply.
Note that in the preceding cases, for illustrative purposes, the nominal secondary engine torque condition is shown to be zero. However, the approaches can be applied to other conditions, such as non-zero nominal torque (e.g., the case both the VDE and transaxle motor produce positive torque). In such a case, the motor may provide less positive torque (less energy) during a transition rather than actually recovering energy as shown in the above examples.
Referring now to FIGS. 7–8 , example routines are described for controlling VDE transitions. As shown above, several different examples are described for maintaining the desired engine torque during a VDE transition (4->8 or 8->4). As described below, the approach used to maintain torque during the transition can vary depending on battery SOC, secondary motor torque capacity, secondary motor dynamic torque response, and/or other relevant system conditions.
The flow chart of FIG. 7 begins with an indication from other portions of a powertrain control strategy that a VDE mode transition is desired. The first step ( 710 ) is to determine the effective constraints of the HEV motor and battery to absorb or add torque to the system. The next step ( 712 ) is to select a combination of ignition timing retard, throttle adjustment (before, after, and/or during the transition), and motor torque adjustment (absorption, supply, or combinations thereof) (before, after, and/or during the transition). For example, step 712 may determine whether energy should be stored, spent, or maintained substantially neutral. This determination can be based on conditions such as battery SOC. However, conditions such as a high battery SOC may result in the selection of still another mode (see below). In one approach, energy recovery is nominally selected, except when battery SOC is above a threshold or the system is unable to absorb the required energy. In another approach, the routine has a preset map of the type of compensation to use depending on engine speed/load/torque conditions to minimize engine torque disturbances irrespective of engine storage/release.
Continuing with FIG. 7 , in step 714 the mode transition method determined in step 712 is activated and the desired torque contribution from the HEV motor and engine (valve activation/deactivation timing, ETC MAP control, and/or spark retard, if necessary) is determined. Further, additional adjustments may be added to account for various system limitations (both steady state and dynamic).
Referring now to FIG. 8 , a routine is shown providing an example approach that can be used in place of step 712 . In this example, the amount of motor torque supplied/absorbed (and optionally the timing of motor torque adjustments) can be varied as the batter SOC varies. First, in step 810 , the routine determines whether battery SOC is below a minimum threshold. If so, then the routine continues to maximize the energy recovery (absorb engine torque) in 812 . Otherwise, in step 814 , the routine determines whether battery SOC is greater than a maximum threshold. If so, then the routine continues to step 816 to expend energy during the VDE transition (supply motor torque). Otherwise, in step 818 the routine determines if the battery SOC is within a desired steady state operating conditions. If so, a neutral energy VDE transition mode is selected in step 820 . Otherwise, a default response where the amount of torque supplies/absorbed is may be used to control the battery SOC to a desired value in step 822 .
As will be appreciated that the routines described in FIGS. 7–8 and elsewhere herein may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various steps or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages described herein, but are provided for ease of illustration and description. Although not explicitly illustrated, one of ordinary skill in the art will recognize that one or more of the illustrated steps or functions may be repeatedly performed depending on the particular strategy being used.
The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the valve operating patters, cylinder operating patterns, cylinder stroke variations, valve timing variations, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
This concludes the description. The reading of it by those skilled in the art would bring to mind many alterations and modifications without departing from the spirit and the scope of the disclosure. For example, I3, I4, I5, V6, V8, V10, and V12 engines operating in diesel, natural gas, gasoline, or alternative fuel configurations could be used to advantage.
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A vehicle system is disclosed. The system include a engine capable of disabling and enabling at least one cylinder; a motor coupled to said engine capable of absorbing torque and providing torque; and a controller for disabling and enabling said at least one cylinder, and during at least one of disabling and enabling, varying torque of said motor to compensate for transient changes in engine output torque caused by said one of disabling and enabling.
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This is a continuation-in-part of U.S. patent application Ser. No. 07/667,807, filed on Mar. 11, 1991 and is now U.S. Pat. No. 5,157,230.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a safety device for mounting on an automatically operated garage door which is responsive to engagement with an obstructing object to halt and reverse an operator.
2. Description of the Prior Art
The advent of automatic doors actuated by automatic operators has led to the need for pressure sensitive deactuation devices which are responsive to contact with an object located in the door path to deactuate the operator. A number of injuries, and even deaths, have been reported due to the lack of a effective safety actuator for stopping or reversing an automatic operator upon the door making contact with a hapless person passing through the path thereof.
Current popularity of overhead garage doors driven by an automatic operator for opening and closing have led to further development of various sensing devices. Many such automatic closures incorporate a pressure sensing arrangement along the lower edge of the door such that upon contact with a vehicle or the like will deactuate the operator to minimize damage to the vehicle or door structure. However, such devices typically suffer the shortcoming that the deactuating devices require application of significant amounts of force thus resulting in the impact of damaging or injuring forces to the obstructing object before the deactuator becomes fully operative.
U.S. Pat. No. 3,001,038 to Gazelle recognized the existence of a need for an automatic deactuator highly responsive to the encountering of an obstruction to halt closure. However, the relatively sophisticated and expensive pistons for carrying the moveable edge has proven unduly expensive to fabricate and does not afford the necessary angular range for application of actuating forces for practical use on a one-piece overhead garage door.
Thus, there exists a need for a deactuator which is highly sensitive to contact with an object during closure of the door such that contact with a small child or the like during closure will deactuate the closure to protect the child from injury. The design challenges for such a device are greater for one-piece overhead garage doors since those doors typically close in a manner which swings the free lower end of the door through an arcuate path. This results in contact being made by the lower edge of the door with an obstructing object from any one of a number of different directions throughout a wide range of angles depending on the height of such lower edge at the point of contact.
Prior efforts to devise satisfactory deactuation mechanisms have led to the proposal of a symmetrically shaped semi-circular hollow deflectable channel member mounted centrally on a door edge and carrying an electrical contact and which will be deflected upon impact to engage a cooperating contact to thereby generate an electrical signal. A device of this type is shown in U.S. Pat. No. 1,511,055 to Entwistle. Devices of this type, while satisfactory for their intended uses, suffer the shortcoming that substantial force is required for deflection of the channel and contact with an object at an angle of, for instance, 45° to the plane of the door, typically fails to adequately deflect the channel to make contact and close the circuit.
Other efforts to provide a satisfactorily sensitive door edge sensing mechanism has led to the proposal of pneumatic tubes or the like mounted adjacent the door edge for deformation upon contact to increase the pressure in the tube for sensing by a pressure sensitive switch. A device of this type is shown in U.S. Pat. Nos. 3,303,303 and 4,620,072 to Miller. Such devices, while sufficiently sensitive to be actuated upon engagement of the door edge with a forklift vehicle or the like, typically cannot be designed sufficiently sensitive to respond at different temperatures, under a variety of climatic conditions, and with sufficient sensitivity to fully minimize injury to a person contacted thereby.
Other solutions have been proposed which incorporate electrically conductive strips spaced apart by means of a compressible insulative strip or the like to create a pressure sensitive switch such that compression thereof permits the contacts to come into engagement with one another to thereby generate an electrical signal. Devices of this type are shown in U.S. Pat. Nos. 2,843,690, 3,133,167, 3,855,733, 4,273,974, 4,349,710, 4,396,814, 4,785,143, 4,908,483 and 4,920,243 to Miller. Devices of this general type have been marketed under the trade designation Miller Edge by Miller Edge, Concord Industrial Park, Concordville, Pa. 19331. Such devices, while satisfactory for commercial installations where cost is not of particular consideration, have limited application for use on the free edge of one-piece garage doors since such devices must be capable of mass production and economical to use.
Other efforts to produce a satisfactory device have led to the proposal of spaced apart conductive strips housed in a flexible channel mounted centrally on a door edge and designed with an internal strut work such that forces applied to the channel are intended to act through such struts to press the strips together. Devices of this type are shown in U.S. Pat. Nos. 3,118,984 to Koenig and 4,115,952 to French. The cost of such continuous strips is considerable and range of angles from which actuation forces may be applied is limited.
Devices have also been proposed which incorporate hollow tubes mounted along the edges of automatic doors for containing pressurized fluid which is responsive to application of forces for deactuating an operator. A device of this is shown in U.S. Pat. No. 4,133,365 to Schleicher. Such devices, while satisfactory for installations where the climatic conditions are constant and substantial forces are not objectionable, suffer the shortcoming that such fluid does not typically operate over wide ranges of temperature variations.
A safety edge has also been proposed which incorporates a contact strip in the form of a knife edge, apparently designed to be located centrally on the leading edge of the roller gate or the like. A device of this type is shown in U.S. Pat. No. 5,023,418 to Beckhausen. While satisfactory for use on a roller gate or the like to be advanced along a linear path, such devices fail to detect an object sufficiently far in advance of a one-piece door closing through an arc to satisfactorily avoid injury or damage.
Thus, there exists a need for an actuator apparatus for mounting on the lower edge of a one-piece garage door and configured such that application of forces thereto from various different angles as dictated by the point in the path followed by the lower edge during closure at which contact is made with an obstruction to thereby avoid application of excessive forces to the object.
SUMMARY OF THE INVENTION
The present invention is characterized by an elongated electrically conductive channel mounted from a non-conductive base and formed in cross section with a wall which is, upon contact with an obstruction, deflectable through a predetermined path. Mounted in the interior of the channel and extending throughout the length thereof is an elongated, conductive strip disposed in the path of the deflectable wall such that deflection of such wall through such path results in contact between such wall and strip to thereby complete a circuit which may be utilized to halt and/or reverse operation of the door operator.
Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a safety actuator embodying the present invention;
FIG. 2 is a broken rear view, in enlarged scale, taken along the line 2--2 of FIG. 1;
FIG. 3 is a partial vertical, sectional view, taken along the line 3--3 of FIG. 2;
FIG. 4 is a sectional view, similar to FIG. 3, but showing the safety actuator contacting an object disposed in its path;
FIG. 5 is a schematic of the electrical circuit incorporated in the safety actuator shown in FIG. 2;
FIG. 6 is a broken rear view showing a second embodiment of the safety actuator of the present invention;
FIG. 7 is a schematic depicting the electrical circuit incorporated in the safety actuator shown in FIG. 6;
FIG. 8 is a broken rear view showing a third embodiment of the safety actuator of the present invention;
FIG. 9 is a vertical sectional view, taken along the line 9--9 of FIG. 8;
FIG. 10 is a schematic of an electrical circuit incorporated in the safety actuator shown in FIGS. 2 and 8; and
FIG. 11 is an electrical schematic showing a modification of the electrical circuit depicted in FIG. 10 and is shown in FIGS. 6 and 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, the safety actuator apparatus of the present invention includes, generally, an elongated sensor fitting 11 mounted on the interior lower edge of a one-piece overhead garage door 13. The sensor fitting includes an elongated L-shaped base, generally designated 15, constructed of an electrically insulative vinyl compound. Mounting on the face thereof is an elliptical in cross section hollow elongated sensor channel 17 constructed of an electrically conductive vinyl compound. The wall of the sensor channel 17 is deflectable inwardly along its length, such as along a path defined by an extension of the vector arrow 21 shown in FIG. 3. A generally J-shaped in cross section electrical strip, generally designated 25, also constructed of an electrically conductive vinyl compound, is mounted within the chamber defined by the interior of the channel 17 such that it may be engaged by the wall of such channel upon deflection inwardly along the extended path of the vector arrow 21 as shown in FIG. 4 to thus complete a circuit between the wall of such channel and the contact strip device 25.
The need for a highly sensitive tactile safety actuator has become of such great concern that various governmental agencies have considered and have, in fact, enacted legislation restricting the sale, installation or repair of automatic door operators which fail to incorporate an effective safety actuation device for sensing and controlling an operator which is normally operative to close a garage door. The problems encountered in designing a safety actuator for a one-piece overhead garage door are somewhat different from that encountered in the design of doors travelling on a linear track, such as a sectional garage door, elevator door, or various industrial doors and common carrier doors. That is, one-piece overhead garage doors are typically mounted from a suspension mechanism, such as the mechanism generally designated 31 in FIG. 1 whereby the bottom edge of the door generally lifts up and translates outwardly and upwardly upon opening and follows a reverse path upon closing. It is of recognized concern that during closure the bottom end of the door follows a somewhat arcuate path travelling downwardly and inwardly toward the door frame. Travel is initially primarily downwardly in a vertical direction concluding with travel in a direction which is primarily horizontal. Thus, the direction from which the lower edge of such door approaches an object during travel throughout its closure path varies progressively from a direction which is primarily vertical to one which is primarily horizontal. Accordingly, the safety actuator of my invention is intended to be responsive to contact with an obstructing object throughout the entire closure path, irrespective of the point in that path at which the object is engaged.
The opening and closing of such garage doors is typically compelled by an overhead garage door opener, generally designated 35 (FIG. 1) which is coupled with an arm 37, as by a screw drive or chain, such that a receiver will be responsive to actuation of a remote transmitter to thereby initiate operating and actuate a motor to drive the door to its open or closed position.
It is this path of travel during closure of the door that renders relatively fail safe operation of the sensor 11 somewhat difficult. That is, the obstructing object may be encountered at any height from just several inches off the floor to a position disposed five to seven feet above the floor or driveway. Consequently, the lower door edge may be, at the time of impact with an obstructing object, travelling through a path which has a primarily vertical component or may, as for instance, toward the completion of its closure path, have a primarily horizontal component, or during any intermediate portion of that path, a combination of horizontal and vertical components that is generally varying with the height of the lower door edge. It will be appreciated that with this construction, a generally conventional pressure sensitive contact strip arrangement mounted directly on the bottom edge of the door will be of little usefulness during that portion of the closure path when the door is travelling primarily in the vertical travel direction. Thus, the deactivating sensor device 11 is preferably mounted such that the sensor channel 17 projects from the inner face of the door at the lower margin thereof.
Electrically conductive vinyl compounds have long been known in the marketplace for various applications and one such supplier for the compound utilized in the preferred embodiment is Product No. A100-1 from Teknor Apex Company, 505 Central Avenue, Pawtucket, R.I. The compound may be extruded in a manner known to those skilled in the art such that the L-shaped base 15 (FIG. 3) of non-conductive compound may be extruded integral with the channel 17 and, if desirable, the conductive strip device 25. The extruded sensor device 11 may thus be supplied in strip form and cut to the desired length.
The cross section of the base 15 is preferably L-shaped to cap the inner lower corner of the door and embrace the lower interior margin of the door and bottom edge thereof. The channel 17 is preferably of a generally elliptical cross sectional shape to define a deflectable nose which, in response to rather minor forces, as represented by the vector arrow 21, will readily deflect inwardly.
The cross section of contact device 25 may be in the form of a single linear strip or, as shown in the preferred combination, may be somewhat in the form of the letter J to define a main leg 41 projecting perpendicular to the face of the door 13 and a minor leg 43 angling generally downwardly and outwardly approximately 45° to the face of such door. Thus deflection of the wall of the channel 17 near the base resulting from contact with an object from a somewhat oblique direction will serve to make contact with the minor leg 43 while contact of the apex thereof during initial downward travel will serve to deflect such apex to make contact with the tip end of the major leg 41.
Referring to FIGS. 1 and 2, the operator 35 incorporates a switch (not shown) operative in response to an electrical signal to deactuate the operator. The terminals of that switch are connected with the sensor channel 17 and contact device 25 by means of respective electrical cables 45 and 47. Referring to FIG. 2 in the embodiment shown for illustrative purposes, one such terminal is connected to the distal end of the sensor channel 17 by means of the lead 45 and the opposite such terminal is connected with the proximal end of the contact device 41 by means of the cable 47. It will be appreciated by those skilled in the art that the invention may be incorporated in numerous different embodiments including those having such cables both connected at the same end of such sensor device 11.
Referring to FIG. 5, the reversible motor 51 of the operator 35 is connected with a logic board 53 which acts as a reverse switching mechanism, the sensor device 11 and up and down limit switches, generally designated 57 and 59, respectively. In the embodiment shown, the lead cables 45 and 47 incorporate the safety feature afforded by dual leads.
In operation, the sensor device 11, cables 45 and 47, operator 35, and logic board 53 will typically be marketed packaged together and the installer may merely unpackage the components and install the operator in a conventional manner. The sensor device 11 may then be installed on the inside lower edge of the door 13 and the cable 45 threaded through the hollow interior of the channel 17 to connect the end thereof with the distal end to maintain good electrical contact. The cable 47 may then be connected with the proximal end of the sensor device 25 as shown in FIG. 2.
Then, upon operation, the door may be opened and closed in a conventional manner. However, should the sensor device 11 come into contact with an obstructing object during closure thereof, the wall of such channel 17 will be deflected inwardly, as for instance along the vector path 21, to engage either or both the contact legs 43 or 41. As shown in FIG. 4, in the event contact is made with the minor leg 43, the circuit will be closed, thus switching the logic board 53 to reverse the circuit to the motor 51 to reverse travel of the door. In practice, the flexure of the wall of the channel 17 is such that even the lightest contact with a relatively vulnerable body part, such as a child's neck, will be sufficient to deflect such wall sufficiently to short against the contact device 25, all in response to a force well within the range which will avoid injury to a child's arm, hand or neck. Thus, the sensor device of the present invention provides a effective and safe arrangement for deactuating an automatic door opener before a person disposed in the path thereof might be subjected to injury.
The safety actuator sensor device shown in FIGS. 6 and 7 is somewhat similar to that shown in FIGS. 2 and 5 except that a shunt resistor 61 is connected between the sensor channel 17 and contact device 25 to thereby provide a closed circuit. The remote end of the sensor channel 17 is then connected with the logic board 53 by means of a lead 65 (FIG. 7) and the contact device 25 connected therewith by means of a lead 67. Accordingly, when contact is made between the wall of the sensor channel 17 and contact device 25, a current path is set up parallel to the shunt resistor 61 to thereby provide an overall reduced resistance which will be sensed in the logic board 53 to reverse the motor 51 of the operator 35.
The safety actuator sensor device shown in FIGS. 8 and 9 is an alternate embodiment of the present invention. In this embodiment, the safety actuator of the present invention is mounted to the interior lower edge of a one-piece overhead garage door 13 by an elongated hollow semi-rigid mounting channel 69. The sensor channel 70 is generally C-shaped in cross section and is formed at one lateral side with an internal mounting flange 73 and at is opposite lateral side with an out turned mounting flange 75. An elongated electrically conductive sensor strip, generally designated 72, is configured to nest against the lower inner corner of the mounting channel 69. For the purpose of illustration, electrical terminals 76 and 77 are shown attached to one end of the sensor strip 72 and one end of the sensor channel 70 via screw fasteners. Alternatively, pop rivets may be employed.
The mounting channel 69 is preferably generally rectangular cross sectional shape to provide an interiorly extended support structure of approximately two inches to dispose the actuator sensor spaced inwardly from the inner surface of the door so that during door closure it will precede the lower door edge tangentially in the circumference of the arc created by the moving lower door edge. The bottom wall of the mounting channel 69 is preferably L-shaped to define a jog which caps the inner lower corner of the door and embraces the lower interior margin of the door and bottom edge thereof and serves to, when the door is closed, dispose the lowermost periphery of the sensor channel 70 at or above the level of the bottom edge of such door. The mounting channel 69 is generally rectangular in cross section and is constructed of a semi-rigid PVC or the like so as to preclude injury or damage to an obstructing object upon contact therewith.
The cross section of the wall of the sensor defines a deflectable surface 74 which, responsive to a rather minor force acting from any of a variety of angles, as represented by the vector arrows 71a-d, to readily deflect such wall inwardly and engage the contact strip 72.
The contact strip 72 is disposed generally in the path of the wall of contact strip channel 70 so that upon inward deflection thereof from any direction through about a 90° arc of directions represented by vectors 71a-d, contact will be made with such strip.
In operation, the sensor 68 may be mounted on the inner lower edge of a garage door 13. When the operator is activated to close the door, such lower edge will, as viewed in FIG. 9, be swung downwardly and to the left toward the position shown. As such edge swings downwardly, it will carry the sensor channel through an arcuate path essentially leading such lower edge through its path. With the configuration shown, it will be clear that, should any object even as small as that which would rise only one or two inches from the floor in the vicinity of the position normally occupied by the lower door edge, when closed, engagement will be made with the mounting channel 69 configured to span the contact strip 72 two inches in front of the lower front door edge. It will be apparent that, for an object as small as the diameter of a baby's arm, the wall of such sensor channel 70 will engage well ahead of the door thus causing such wall to deflect inwardly to engage such contact strip 72 to thus deactuate and reverse the door operator. The construction of FIG. 9 offers the advantage that should the door continue its downward path for a short period of time after closure of the wall of the sensor channel 70 on the contact strip 72 and generation of the stop and reverse signal, a cushioning effect is provided. That is, upon contact of the inwardly deflected wall of the sensor channel 70 with the contact strip 72, the wall of the mounting channel 69 is free to, under further force or displacement, flex inwardly toward the face of the door 13 thus minimizing the application of any greater force to the object encountered.
The terminal lead diagram in FIG. 10 is similar to FIG. 5 except that the actuator sensor device shape is not shown in the diagram. The four-wire system (45, 47) interconnects the logic board 35 with the sensor channel 70 and contact strip 72 and allows the continuity of cables 45 and 47 to be continually monitored.
The terminal lead diagram in FIG. 11 is similar to FIG. 7 and illustrates a two wire system. The terminal leads connect the sensor channel and contact strips 72 by means of electrical cables 65 and 67. The circuit through resistor 61 serves to continually allow the conductors' continuity to be monitored.
From the foregoing, it will be apparent that the sensor device of the present invention provides an economical and reliable means for sensing the existence of an obstructing object in the path of a one-piece overhead door during closure thereof and which is responsive thereto to reverse an automatic garage door operator.
Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.
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An elongated, electrically conductive, inwardly protruding hollow channel defining an interior chamber is mounted to the lower edge of a one-piece garage door. Mounted within the chamber is a contact strip extending longitudinally along the channel and disposed below the center line thereof such that deflection interiorly of the wall of the channel upon contact with an obstructing object will cause it to engage the contact strip. The channel is optionally mounted to a base perpendicularly extending away from the plane of the door to provide early warning of a contact with an obstructing object.
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