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This application is a continuation of, and claims the benefit of, U.S. patent application Ser. No. 09/821,299 filed on Mar. 29, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/654,024 filed on Sep. 1, 2000, now U.S. Pat. No. 6,363,683 and which is a continuation of U.S. Ser. No. 09/008,437 now U.S. Pat. No. 6,170,220, filed Jan. 16, 1998, and issued Jan. 9, 2001, all of which are incorporated herein in their entireties.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention encompasses a building component used to make an insulated concrete structure and, more particularly, a system that is formed using a side panel and a sheet, such as plywood, in which the sheet may optionally be removed.
2. Background Art
Concrete walls in building construction are most often produced by first setting up two parallel form walls and pouring concrete into the space between the forms. After the concrete hardens, the builder then removes the forms, leaving the cured concrete wall.
This prior art technique has drawbacks. Formation of the concrete walls is inefficient because of the time required to erect the forms, wait until the concrete cures, and take down the forms. This prior art technique, therefore, is an expensive, labor-intensive process.
Accordingly, techniques have developed for forming modular concrete walls that use a foam insulating material. The modular form walls are set up parallel to each other and connecting components hold the two form walls in place relative to each other while concrete is poured therebetween. The form walls, however, remain in place after the concrete cures. That is, the form walls, which are constructed of foam insulating material, are a permanent part of the building after the concrete cures. The concrete walls made using this technique can be stacked on top of each other many stories high to form all of a building's walls. In addition to the efficiency gained by retaining the form walls as part of the permanent structure, the materials of the form walls often provide adequate insulation for the building.
One embodiment of form walls is disclosed in U.S. Pat. No. 5,390,459, which issued to Mensen on Feb. 21, 1995, and which is incorporated herein by reference. This patent discloses “bridging members” that comprise end plates connected by a plurality of web members. The bridging members also use reinforcing ribs, reinforcing webs, reinforcing members extending from the upper edge of the web member to the top side of the end plates, and reinforcing members extending from the lower edge of the web member to the bottom side of the end plates. As one skilled in the art will appreciate, this support system is expensive to construct, which increases the cost of the formed wall. Also, these walls cannot feasibly be used to make floors or roof panels.
SUMMARY OF THE INVENTION
The present invention provides an insulated concrete form comprising at least one longitudinally-extending side panel and at least one web member partially disposed within the side panel. The web member extends from adjacent the external surface of the side panel through and out of the interior surface of the side panel. Three embodiments of the present invention that may be used to construct a concrete form are described herein. The first embodiment uses opposed side panels that form a cavity therebetween into which concrete is poured and substantially cured. The second embodiment uses a single side panel as a form, onto which concrete is either poured or below which concrete is poured and the form inserted into. Once the concrete cures and bonds to the side panel in the second embodiment, it is used as a tilt-up wall, floor, or roof panel. The third embodiment operates similar to the first embodiment but, instead of having two opposed side panels to form the cavity, the present invention uses one side panel and an opposed sheet or other form on the opposed side to form the cavity. After the concrete substantially cures in the third embodiment, the sheet can be removed and reused again or, alternatively, remain as part of the formed structure. If the sheet is removed, the resulting structure is similar to a tilt-up wall formed using the second embodiment of the present invention.
In the first embodiment, the web member is preferably partially disposed in the side panel so that a portion of the web member projects beyond the interior surface of the side panel and faces but does not touch an opposing side panel. The first embodiment also uses a connector that attaches to the two web members in opposing side panels, thereby bridging the gap between the two side panels to position the side panels relative to each other. The connectors preferably have apertures to hold horizontally disposed re-bar. The connectors also have different lengths, creating cavities of different widths for forming concrete walls having different thicknesses. The connectors are interchangeable so that the desired width of the wall can be set at the construction site.
For the second embodiment, a portion of the web member preferably projects beyond the interior surface of the side panel. In one design, the side panel is first horizontally disposed so that the interior surface and portion of the web member extending therethrough are positioned upwardly. Forms are placed around the periphery of the side panel and concrete is then poured onto the interior surface. In a second design, the concrete is poured into a volume defined by perimeter forms and then the side panel is placed upon the fluid concrete so that at least a portion of the web member in the side panel is disposed in the concrete. Alternatively, a third design is formed as a hybrid of the first and second designs, namely, one side panel is horizontally disposed, concrete is poured onto the interior surface and contained by forms, and then another panel is place upon the poured concrete so that side panels are on both sides of the concrete. For all three designs, once the concrete substantially cures and bonds with the interior surface of the side panel and the portion of the web member extending therethrough, the side panels and connected concrete slab can be used as a tilt-up wall, flooring member, or roof panel.
The third embodiment of the present invention encompasses a process generally similar to the first embodiment, except that a sheet of plywood or the like is used instead of a second side panel. The sheet can either be removed after the concrete cures and used again or remain part of the formed structure.
The present invention further comprises components to improve the walls formed using side panels and to simplify the construction process.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the present invention.
FIG. 2 is a perspective side view of a FIG. 1 taken along line 2 — 2 .
FIG. 2A is an alternative view of FIG. 2 showing concrete disposed between the two opposed side panels. FIG. 2A also shows the tilt-up wall formed with side panels on the two opposed sides of the concrete that has been erected.
FIG. 3 is a perspective view of one side panel shown in FIG. 1, in which three web members show four attachment points extending through the interior surface of the side panel. Two of the web members show two connectors attached to attachment points and one web member shows two connectors and a stand-alone web member attached to those two connectors.
FIG. 4 is a perspective view of the connector shown in FIG. 3 .
FIG. 4A is a perspective view of an alternative of the connector shown in FIG. 4 .
FIG. 5 is a perspective view of one design of the side panel of the present invention, in which a portion of the side panel is cut away to show the body portion of he web member partially disposed and integrally formed therein.
FIG. 6 is an exploded perspective view of an alternative design of the web ember shown in FIGS. 3 and 5 and having five attachment points instead of four. FIG. 6 also shows an anchor and an extender used in conjunction with the different embodiments of the present invention.
FIG. 7 is a perspective view of a second embodiment of the present invention showing generally the concrete formed below the side panel.
FIG. 8 is another perspective view of the second embodiment of the present invention showing generally the concrete formed above the side panel.
FIG. 9 is a perspective view of a third embodiment of the present invention showing a cavity defined by a side panel and a sheet.
FIG. 9A is an alternative view of FIG. 9 showing concrete disposed between the side panel and the sheet.
FIG. 10 is a perspective view of a stand-alone web member and a connector, both of which include a spacer.
FIG. 11 is a perspective view of an upstanding concrete structure formed by two of the second embodiments or the third embodiment of the present invention, which are shown in FIGS. 7, 8 , 9 , and 9 A.
FIG. 12 is a cross-sectional side view showing two opposed side panels and the web members partially disposed therein, in which the side panels are interconnected in various combinations by flexible linking members joining extenders or slots formed into the web members.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a,” “an,” and “the” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures.
As shown in FIGS. 1-12, the present invention comprises a concrete form system 10 used for constructing buildings. A first embodiment of the present invention, shown best in FIGS. 1-2A, comprises at least two opposed longitudinally-extending side panels 20 , at least one web member 40 partially disposed within each of the side panels 20 , and a connector 50 disposed between the side panels 20 for connecting the web members 40 to each other. As shown in FIG. 2A, concrete C is poured between the side panels 20 so that it bonds with the side panels 20 and the web members 40 . Two designs of a second embodiment of the present invention, which is discussed in more detail below and shown in FIGS. 7 and 8, involves using a single side panel 20 that bonds with the concrete C, instead of using opposed side panels 20 on both sides of the concrete C. The second embodiment also includes a design in which the wall has side panels 20 on both sides of the concrete to appear as the wall in FIG. 2A, but is formed differently from the first embodiment. A third embodiment of the present invention is shown in FIGS. 9 and 9A and is similar to the first embodiment, but uses one side panel 20 and a sheet 80 instead of two opposed side panels 20 .
Each side panel 20 has a top end 24 , a bottom end 26 , a first end 28 , a second end 30 , an exterior surface 32 , and an interior surface 34 . The presently preferred side panel 20 has a thickness (separation between the interior surface 34 and exterior surface 32 ) of approximately two and a half (2½) inches, a height (separation between the bottom end 26 and the top end 24 ) of sixteen (16) inches, and a length (separation between the first end 28 and second end 30 ) of forty-eight (48) inches. The dimensions may be altered, if desired, for different building projects, such as increasing the thickness of the side panel 20 for more insulation. Half sections of the side panels 20 can be used for footings.
Referring now to FIGS. 1 and 2 showing the first embodiment of the present invention, the interior surface 34 of one side panel 20 faces the interior surface 34 of another side panel 20 and the opposed interior surfaces 34 are laterally spaced apart from each other a desired separation distance so that a cavity 38 is formed therebetween. Concrete—in its fluid state—is poured into the cavity 38 and allowed to substantially cure (i.e., harden) therein to form the wall 10 , as shown in FIG. 2 A. Preferably, for the first embodiment, the opposed interior surfaces 34 are parallel to each other. The volume of concrete received within the cavity 38 is defined by the separation distance between the interior surfaces 34 , the height of the side panels 20 , and the length of the side panels 20 .
The side panels 20 are preferably constructed of polystyrene, specifically expanded polystyrene (“EPS”), which provides thermal insulation and sufficient strength to hold the poured concrete C until it substantially cures. The formed concrete wall 10 using polystyrene with the poured concrete C has a high insulating value so that no additional insulation is usually required. In addition, the formed walls have a high impedance to sound transmission.
As best shown in FIGS. 3 and 5, the interior surface 34 preferably includes a series of indentations 36 therein that increase the surface area between the side panels 20 and concrete C to enhance the bond therebetween. To improve further the bond between the side panels 20 and the concrete C poured in the cavity 38 , a portion of each of the web members 40 formed in or passing through the side panels 20 extends through the interior surface 34 of the side panels 20 into the cavity 38 . A portion of each web member 40 is preferably integrally formed within one side panel 20 and is also cured within the concrete C so that the web member 40 strengthens the connection between the side panel 20 and the concrete C. That is, since the web member 40 is preferably an integral part of the side panel 20 , it bonds the side panel 20 to the concrete C once the concrete is poured and substantially cures within the cavity 38 . However, other designs are contemplated, such as designs in which the web member is not integrally formed into the side panel and, for example, the web member is slid into slots precut into the side panel at the construction site.
As shown in FIGS. 1-3 and 5 , each side panel 20 has at least one web member 40 formed into it. Preferably, the each web member 40 formed within one side panel 20 is separated a predetermined longitudinal distance from other web members 40 , which is typically eight (8) inches. Based on the preferred length of the side panel 20 of forty-eight (48) inches, six web members 40 are formed within each side panel 20 , as shown in FIGS. 3 and 5.
Portions of each web member 40 that extend through the interior surface 34 of the side panel 20 forms one or more attachment points 44 . The attachment points 44 are disposed within the cavity 38 and are preferably spaced apart from the interior surface 34 of the side panels 20 in the first embodiment. However, as one skilled in the art will appreciate, the attachment points 44 may take any of a number of alternate designs formed by or independently of the web members 40 , including as examples: slots, channels, grooves, projections or recesses formed in the side panels; hooks or eyelets projecting from or formed into the side panels; twist, compression or snap couplings; or other coupling means for engaging cooperating ends of the connectors.
Preferably, as addressed in more detail below and as shown best in FIGS. 3, 5 , and 6 , each attachment point 44 is substantially rectangular and flat in plan view to be complementarily and slidably received within one respective end 52 of the connector 50 . Thus, in the first embodiment, the connectors 50 shown in FIGS. 4 and 4A engage two attachment points 44 on opposed web members 40 , which position the interior surfaces 34 of the side panels 20 at a desired separation distance and support the side panels 20 when the fluid concrete is poured into the cavity 38 . In the preferred embodiment, the connector 50 makes a two-point connection with opposed web members 40 because each connector has two ends 52 that each couple to one attachment point 44 , although it is contemplated making a four-point connection (i.e., each connector 50 engages four attachment points 44 instead of two as illustrated in the figures).
Referring now to FIGS. 3, 6 , and 10 , each web member 40 also preferably has an end plate 42 that is disposed adjacent the exterior surface 32 of the side panel 20 in the preferred embodiment. The end plates 42 are preferably substantially rectangular in plan view. Except when used as a stand-alone web member 40 ′ for the third embodiment as discussed below, each end plate 42 of the web members 40 is preferably completely disposed within a portion of one respective side panel 20 , as shown best in FIGS. 2 and 5. That is, the end plates 42 are located slightly below the exterior surface 32 of, or recessed within, the side panel 20 , preferably at a distance of one-quarter (¼) of an inch from the exterior surface 32 . This position allows for easily smoothing the surface of the side panels 20 without cutting the end plate 42 should the concrete, when poured, create a slight bulge in the exterior surface 32 of the side panels 20 . However, when embedded within the side panel 20 , it is desired that some visual indicia be included on the external surface 32 to enable the construction worker to locate quickly and accurately the end plate 42 . Alternatively, the end plates 42 can abut the exterior surface 32 of panels 20 so that a portion of the end plate 42 is exposed over the exterior surface 32 . It is also preferred in the first and third embodiments that each end plate 42 is oriented substantially upright and disposed substantially parallel to the exterior surface 32 of the side panel 20 when forming a concrete form 10 .
Similar to the end plate 42 , the attachment points 44 are also preferably oriented substantially upright in the first and third embodiments so that one attachment point 44 is disposed above another attachment point 44 . As best shown in FIGS. 2, 3 , and 9 , in one design each of the web members 40 has four spaced-apart attachment points 44 , in which the attachment points 44 for each web member 40 are vertically disposed within the cavity 38 in a substantially linear relationship. The attachment points 44 are placed in two groups—a top group of two attachment points 44 and a bottom group of two attachment points 44 . Adjacent attachment points 44 in the two groups are spaced apart a first distance from each other, preferably approximately two and an eighth (2⅛) inches apart between center points. In addition, the closest attachment points 44 of the two groups, i.e., the lowermost attachment point 44 of the top group and the uppermost attachment point 44 of the bottom group, are spaced apart a second distance from each other. The second distance, which is approximately six (6) inches in the preferred embodiment for a twelve (12) inch connector, is more than double and almost triple the first distance.
In an alternative design, the web member 40 includes five attachment points 44 , which is illustrated best in FIG. 6 . This design also has the two groups of two attachment points 44 as discussed above, but also includes a fifth attachment point 44 at approximately the center of the two groups. This design having five attachment points 44 is presently preferred over the web member 40 having four attachment points because it provides even greater flexibility for the architect and/or construction worker. As one skilled in the art will appreciate, the number of attachment points 44 used for each web member 40 can be further varied in number and spacing based on relevant factors such as the dimensions of the side panels 20 and the wall strength or reinforcement desired.
The designs of the multiple attachment points 44 of the present invention is an improvement over prior art systems, which lack multiple mounting points for attaching an interconnecting device. The side panels 20 and web members 40 in the present invention can be cut horizontally over a wide range of heights to satisfy architectural requirements, such as leaving an area for windows, forming odd wall heights, and the like, yet still have at least two or three attachment points 44 to maintain structural integrity of the wall. Prior art systems, in contrast, lose structural integrity if cut horizontally, thus requiring extensive bracing to resist collapsing when concrete is poured into the cavity between the panels. One skilled in the art, however, will appreciate that the web member of the present invention is not limited to these exemplary designs and can include other shapes in which a portion is disposed adjacent both the interior and exterior surfaces in which the web member is disposed.
Referring again to FIGS. 1 and 2 showing the first embodiment of the present invention, the attachment points 44 of the web members 40 extend into the cavity 38 and the attachment points 44 of each web member 40 formed within one side panel 20 are spaced apart from the attachment points 44 of the web members 40 formed within the opposed side panel 20 . Thus, the web members 40 preferably do not directly contact each other; instead, each attachment point 44 independently engages the connector 50 that interconnects the web members 40 and, accordingly, the side panels 20 .
Referring now to FIGS. 4 and 4A, the illustrated connectors 50 have opposed ends 52 and a length extending therebetween. The ends 52 of the connectors 50 are each of a shape to engage one attachment point 44 of two respective web members 40 within opposed panels. As mentioned above and as best shown in FIGS. 5, 6 , and 12 , the attachment points 44 are preferably substantially rectangular and flat and a stem 48 extends the attachment point 44 through the side panel 20 from the remaining portions of the web member 40 . As such, the stem 48 and the attachment point 44 are “T” shaped in cross-sectional view, in which the attachment point forms the top of the “T.”
In conjunction, as best shown in FIGS. 4 and 4A, each end 52 of the connector 50 has a track 54 into which the preferably rectangular attachment point 44 is complementarily and slidably received. The connector 50 , accordingly, is movable between a separated position and an attached position. In the separated position (as illustrated, for example, in FIGS. 4 and 4 A), the end 52 of the connector 50 is spaced apart from the respective attachment point 44 to which it will be connected. In the attached position, the end 52 of the connector 50 is engaged to the attachment point 44 , which is shown, for example, in FIGS. 2 and 3.
In the preferred embodiment, the ends 52 of the connector 50 are detachably locked to the respective attachment points 44 when in the attached position. By being detachably locked, it will be appreciated that, while only contacting the connector 50 , an applying force needed to remove the connector 50 from the attachment point 44 is greater than a force needed to attach that connector to that attachment point 44 . Stated differently, an applying force needed to move the connector 50 from the separated to the attached position is less than a removing force needed to move the connector 50 from the attached to the separated position. The differences in the applying and removing forces may be slight or significant and still be within the scope of the present invention.
The present invention thus comprises a means for detachably locking the end 52 of the connector 50 into the attached position. The preferred embodiment of the locking means is illustrated in FIGS. 4A and 6. Referring first to FIG. 6, latching members 46 are disposed either above and below the attachment points 44 , although it is acceptable if only one latching member 46 is disposed either above or below the attachment point 44 . The latching members 46 are preferably integrally formed as part of the web member 40 , but can alternatively either be affixed to the web member 40 after it is formed or be connected to the side panel 20 . As shown in FIG. 6, the tip 47 of the latching member 46 is spaced apart from the attachment point 44 and, preferably, flexibly movable but predisposed or biased to be in an extended position, again as shown in FIG. 6 . Since it is preferred that the tip 47 of the latching member 46 be flexible, the latching member 46 may be formed as a relatively thin component, which should not prevent the latching member 46 from performing its intended function.
In conjunction, referring again to FIG. 4A, the connector 50 has a detent 58 disposed above its track 54 . Specifically, the illustrated detent 58 is an indentation formed at the center of the closed end of the track 54 (which is shown as the top end in FIG. 4 A). It is further preferred that the detent 58 include a raised back 59 that is located at the back end of the detent 58 . As one skilled in the art will appreciate, however, the detent 58 can be aligned differently such that, for example, the detent 58 is in the center of the closed end of the track 54 instead of at its top or the detent 58 is off-center instead of in the middle of the closed end.
To move the connector 50 shown in FIG. 4A to the attached position onto the web member 40 shown in FIG. 6, the bottom of the track 54 of the connector 50 is aligned with the top edge of a one attachment point 44 and slid vertically downwardly while the web member 40 is oriented in an upstanding position. Although not preferred or discussed further, the connector could alternatively be aligned with the bottom edge of the selected attachment point and slid upwardly. As the closed portion of track 54 of the connector 50 slides closer to the attachment point 44 while moving downwardly, the closed portion contacts the flexible tip 47 of the latching member 46 . That contact moves the tip 47 of the latching member 46 inwardly toward the end plate 42 of the web member 40 until the detent 58 is aligned with the tip 47 of the latching member 46 , at which time the latching member 46 extends outwardly away from the end plate 42 to its normal extended position to be complementarily received within the detent 58 . Thus, at that point (which preferably is reached when the attachment point 44 is fully received within the track 54 of the connector 50 ), the connector 50 is detachably locked into place by the tip 47 of the latching member 46 being positioned within the detent 58 so that the connector 50 cannot be freely removed from the attachment point 44 . In conjunction, the raised back 59 behind the detent 58 prevents the tip 47 from over extending beyond the detent 58 .
As one skilled in the art will appreciate, the locking means shown in FIGS. 4A and 6 allows the connector 50 to be easily slid down onto the attachment point 44 using very light downward force (i.e., with just two fingers) to latch the connector 50 to the attachment point 44 . That is, the preferred embodiment of the connector 50 shown in FIGS. 4A and 6 allows a construction worker to slide relatively “loosely” the end 52 of the connector 50 onto the attachment point 44 without significant frictional resistance. Such a design is advantageous because even mild frictional resistance may be burdensome given the number of connectors 50 involved in some construction projects, which may literally involve thousands of connectors 50 each attaching to two web members 40 in opposed side panels 20 . The scope of the connections made may be appreciated by considering FIG. 2, which shows the connections for one pair of opposed side panels 20 . As such, this less burdensome process may translate into a reduction in the amount of time necessary to attach the connectors 50 to the attachment points 44 .
To remove the connector 50 from the attachment point 44 back to the separated position (which is unusual to occur during a construction project), the flexible tip 47 of the latching member 46 must be pressed inwardly away from the detent 58 and toward the end plate 42 and, concurrently, the connector 50 must be slid upwardly toward the latching member 46 a sufficient distance so that the tip 47 of the latching member 46 is no longer aligned or in registry with the detent 58 . After this initial movement, the connector 50 can be removed from the attachment point 44 , either while still holding the tip 47 of the latching member 46 in the compressed position or releasing the latching member 46 so that its tip 47 contacts the closed portion of the track 54 .
Thus, although there is low frictional resistance moving the connector 50 to the attached position, the detachably locked connector 50 cannot easily be removed—even with strong upward force—unless the flexible tip 47 of the latching member 46 is compressed, which often requires a two-handed operation to separate the connector 50 from the web member 40 . This latching design further allows a construction worker or foreman to verify that a connector 50 is properly attached to the web members 40 by tapping on the bottom of the connector 50 and having the connector 50 remain in place, whereas other designs might result in the connector 50 “popping off” the attachment points 44 in response to such an upward tapping force. Further, the detachably locking design also more effectively resists the upward forces exerted by concrete to the connectors 50 as the fluid concrete is first placed, or pumped, into the cavity 38 of the concrete form. In so resisting the forces applied by the fluid concrete, the connectors 50 keep the side panels 20 in place and maintain the integrity of the structure when subjected to various forces or pressures.
Another embodiment of the locking means is shown referring to FIG. 4 . As will be noted, the track 54 of the connector 50 forms a gap 56 into which a portion of the stem 48 is complementarily received when the connector 50 is moved to the attached position. The locking means in this embodiment comprises at least one barb 55 on the track 54 of the connector 50 that is oriented into the gap 56 and a corresponding indentation 49 on the stem 48 of the web member 40 (as shown in FIG. 6 ). As such, when the connector 50 is in the attached position, the barb 55 is complementarily received into the indentation 49 . FIG. 4 shows two spaced-apart barbs 55 extending toward each other in the gap and there would be two corresponding indentations 49 formed into the stem 48 . These barbs 55 provide a frictional fit between the connector 50 and the attachment point 44 of the web member 40 to hold the connector 50 at the attached position. However, the frictional resistance also exists when moving the connectors 50 to the attached position, which makes this embodiment of the locking means less desired.
One skilled in the art will appreciate that the locking means for the connectors 50 can also be used for the stanchions (some embodiments of which are discussed below and shown in FIG. 6 ). One skilled in the art will further appreciate that other locking means are possible, such as having the latching member 46 formed on the connector 50 and the detent 58 formed on the web member 40 .
Referring again to FIGS. 2, 4 , and 4 A, the connectors 50 also preferably define an aperture 56 of a size to complementary receive a re-bar (not shown) therein. The re-bar provides reinforcing strength to the formed wall. The diameter of the re-bar can be one quarter (¼) inch or other dimension as required for the necessary reinforcement, which depends on the thickness of the concrete wall and the design engineering requirements. The connectors 50 preferably have two or more apertures 56 and re-bar can be positioned in any of the apertures 56 before the concrete is poured into the cavity 38 . The apertures 56 can be designed so that the re-bar is securably snapped into place for ease of assembly.
To vary the width of the cavity 38 (i.e., the separation between the interior surfaces 34 of the opposed side panels 20 ), different connectors 50 can have varying lengths. The width of the cavity 38 can be two (2), four (4), six (6), eight (8) inches or greater separation. Different connectors 50 are sized accordingly to obtain the desired width of the cavity 38 . Also, as one skilled in the art will appreciate, the fire rating, sound insulation, and thermal insulation increase as the width of the cavity 38 , which is filled with concrete, increases. One skilled in the art will appreciate that the cavity 38 may only be partially filled with concrete, but such an embodiment is not preferred or desired.
The web members 40 and connectors 50 are preferably constructed of plastic, more preferably high-density plastic such as high-density polyethylene or high-density polypropylene, although other suitable polymers may be used. Other contemplated high-density plastics include acrylonitrile butadiene styrene (“ABS”) and glass-filled polyethylene or polypropylene, particularly for connectors and stanchions since they are more expensive materials. Factors used in choosing the material include the desired strength of the web member 40 and connector 50 and the compatibility with the material used to form side panels 20 and with the concrete. Another consideration is that the end plates 42 should be adapted to receive and frictionally hold a metal fastener, such as a nail or screw, therein, thus providing the “strapping” for a wall system that provides an attachment point for gypsum board (not shown), interior or exterior wall cladding (not shown), or other interior or exterior siding (not shown). Thus, the web members 40 function to align the side panels 20 , hold the side panels 20 in place during a concrete pour, and provide strapping to connect siding and the like to the formed concrete wall 10 .
Referring again to FIG. 1, one skilled in the art will appreciate that a plurality of side panels 20 can be longitudinally aligned to form a predetermined length and be vertically stacked to form a predetermined height. For example, as shown in FIG. 1, the first end 28 of one side panel 20 abuts the second end 30 of another side panel 20 and the bottom end 26 of one side panel 20 is disposed on the top end 24 of another side panel 20 . Thus, a series of side panels 20 can be aligned and stacked to form the concrete system 10 into which concrete C is poured to complete the construction of the wall 10 . One consideration, however, is that the side panels 20 are not vertically stacked too high and filled at once so that the pressure on the bottom side panel 20 is greater than the yield strength of the web members 40 or EPS side panels 20 . Instead, the stacked wall of panels 20 can be filled and cured in stages so that the static and dynamic pressures are not excessive on the lower side panels 20 .
To facilitate the stacking of the components, the side panels 20 are optionally provided with a series of projections 35 and indentations 37 that complementarily receive offset projections 35 and indentations 37 from another side panel 20 (i.e., a tongue-and-groove-type system). The projections 35 and indentations 37 in the adjacent side panels 20 mate with each other to form a tight seal that prevents leakage of concrete C during wall formation and prevents loss of energy through the formed wall.
Referring still to FIG. 1 for the first embodiment of the present invention, the present invention also uses corner sections 39 . Preferably, each corner section 39 forms a substantially right angle and concrete C is also poured into the corner section similar to the other sections of the concrete form system 10 . Forty-five degree angle corner sections can also be used. Thus, the formed concrete wall is contiguous for maximum strength, as opposed to being separately connected blocks. Still another embodiment of the present invention, which is not shown, uses non-linear side panels so that the formed wall has curvature instead of being straight.
The first embodiment of the present invention is an improvement over the prior art. Although other systems may use connector elements, the prior art lacks a web member 40 having an end plate 42 , which provides a nailing/screwing strip adjacent the exterior surface 32 of the side panel 20 , and has an attachment point 44 or similar connection projecting into the cavity 38 adjacent the interior surface 34 . Moreover, the present invention uses less plastic and is, therefore, less expensive to manufacture.
Furthermore, in prior art systems, the panels are made so that large, thick, plastic connector elements slide down in a “T” slot formed within the inside surface of the panel itself These prior art designs are structurally weaker and the construction workers in the field have substantial difficulty avoiding breaking the panels while sliding the connector element into place. Additionally, the prior art panels can break off from the cured concrete if any “pulling” occurs while mounting sheetrock or other materials onto the outer side of the panel. The preferred embodiment of the present invention having the web member 40 integrally formed into the side panel 20 provides a stronger “interlocking” system among the side panels 20 , the web member 40 , and the connectors 50 , which are imbedded within concrete in the cavity 38 . Nonetheless, as mentioned above, it is contemplated within the scope of the present invention using web members 40 that are not integrally formed into the side panels 20 .
Now moving to the second embodiment of the present invention, as noted above, there are three methods of constructing the tilt-up walls 10 of the present invention: (1) pouring the concrete and then inserting the panel 20 into the poured concrete, which is also known as “wet-setting” and is shown in FIG. 7; (2) pouring the concrete onto a substantially horizontally-disposed side panel 20 , which is shown in FIG. 8; or (3) pouring the concrete onto a substantially horizontally-disposed side panel 20 and then inserting the panel 20 into the top surface of the poured concrete so that the concrete is “sandwiched” between two opposed side panels 20 and, when erected, appears the same as the wall 10 formed by the first embodiment shown in FIG. 2 A. All of the walls 10 formed by these three methods or designs are known as tilt-up walls.
As noted, the first two designs of the second embodiment use a side panel 20 on only one side of the formed concrete structure 10 , unlike the third design that uses opposed side panels covering both faces of the concrete C. Thus, the walls 10 formed by the first two designs of this embodiment are insulated on one side, which may be either the interior or exterior of the wall. Leaving the external surface as a concrete surface without a side panel is advantageous for insect control, such as preventing termite infestation since termites cannot burrow through concrete C, but may attack and bore through EPS—the preferred material to form the side panels 20 . Alternatively, leaving the interior surface as a concrete surface is advantageous for warehouses in which fork lifts, for example, could potentially damage any interior finishes by forcefully contacting them, whereas a concrete surface subjected to the same contact will remain substantially unimpaired. The side panels 20 may extend the full or a partial height of the tilt-up wall and, as discussed above, provide both sound impedance and thermal insulation.
For the wet-setting method shown in FIG. 7, it is preferred that a concrete floor slab (not shown), which will serve as a casting base for the tilt-up walls, is formed on a prepared, well-compacted subbase. It has been found that a five-inch (5″) or thicker slab is desired. Also, instead of forming the entire floor during the initial pouring, the slab is typically held back several feet from its ultimate perimeter dimension (i.e., the interior boundaries of the building) to allow space for raising and setting the tilt-up walls after being formed on the floor slab. As discussed below, the gap that exists is subsequently filled in after the tilt-up walls are later erected.
After the floor slab cures, the perimeter foundations or forms (not shown) within which the concrete is poured for forming the tilt-up walls are next positioned and braced to form a substantially contained volume. The perimeter forms are often dimension lumber of sufficient width to allow the walls to be made the desired thickness. Once the periphery forms are in place, door and window openings are blocked out and set. One skilled in the art will also appreciate that reinforcement, typically re-bar, is also positioned within the perimeter forms to be contained within the interior of the tilt-up wall after the concrete is poured. Likewise, items to be embedded within the tilt-up wall, such as for attachments for the lifting cables (discussed below), are also positioned within the perimeter forms.
Concurrently, the side panels 20 are sized and interconnected to match (or, if desired, be smaller than) the length and width dimensions of the tilt-up sections to be cast. Specifically, the side panels 20 are joined together using the projections 35 and indentations 37 (i.e., tongue-and-groove-type connectors) so that a top end 24 of one panel 20 abuts a bottom end 26 of another panel 20 and/or a first end 28 of one panel abuts a second end 30 of another. The side panels 20 are usually joined in a side-by-side configuration while they are horizontally oriented.
The assembled side panels 20 forming an array of panels are preferably fastened together using strongbacks (not shown), which are often a metal “C”-shaped channel or similar device that provides stiffness to the array. Screws are typically used to interconnect the end plates 42 of the web members 40 to the strongbacks, which run the entire height or length of the assembled array of panels 20 .
Either before or after fastening the array of panels together, the side panels 20 are cut not only for height and width dimensions, but also for any penetrations to be included within the tilt-up wall (i.e., windows and doorways), embedded items, and welding plates. The assembled panels with strongbacks are then staged to be “wet set” after consolidation and screeding of the concrete.
With the preliminary steps completed, a release agent is sprayed or poured onto the concrete floor slab or other surface used, if not completed earlier. The fluid concrete is then poured into the perimeter foundations (or other substantially contained volume) and leveled or screeded. The side panels 20 are then “wet set,” in which the interior surface 34 of the side panels 20 are oriented downwardly and pressed firmly into the wet concrete so that a portion of the interior surface 34 of the side panel 20 contacts or is adjacent to the upper surface of the poured concrete.
Two men can easily lift each array of panels, which may measure, in an example construction, four feet by twenty feet. In such an example, each array may be formed of panels abutting end to end 28 , 30 and five arrays of side panels 20 may be coupled together top end 24 to bottom end 26 to form a surface that is twenty feet by twenty feet. If necessary, small “fill-in” pieces of the side panels 20 are easily installed by hand after the arrays of panels are positioned. Compared to insulation mounted onto a tilt-up wall after the concrete slab C has cured, these contiguous, interlocked side panels 20 of the present invention provide superior insulation over systems that have breaks (i.e., at the location of a ferring member) and are significantly less expensive to install.
In the preferred embodiment, each side panel 20 in the array of panels measures sixteen inches by forty-eight inches (16″×48″) and has thirty (30) attachment points 44 that penetrate into the concrete C forming the tilt-up wall. Thus, there are 5.6 penetrations per square foot of wall surface area. If it is believed that the attachment points 44 will not provide a sufficient bond to the concrete C, then stanchions can be used, which are discussed below and some of which are shown in FIG. 6 .
When the side panels 20 are firmly pressed into the wet cement, the attachment points 44 penetrate into the wet concrete. A stinger vibrator (not shown) or the like may also be used on the strongbacks or side panels 20 to aid in the consolidation of the concrete around the attachment points 44 . After setting the side panels 20 , the strongbacks are removed so that the tilt-up system 10 is complete and ready for curing. Once the poured concrete substantially cures and forms a concrete slab C, that slab maintains its relative position against the interior surface 34 of the side panel 20 by the attachment points 44 . That is, by projecting beyond the interior surface 34 of the side panel 20 , the web members 40 anchor the side panel 20 to the concrete slab C so that the concrete slab C and side panel 20 form the tilt-up concrete structure 10 of the present invention. After the concrete slab C is substantially cured, the formed concrete structure 10 is tilted up, as discussed below and shown generally in FIG. 11 .
Referring again to FIG. 7 generally illustrating the wet-setting construction method of the tilt-up walls, one skilled in the art will appreciate that this process has specific benefits. First, the side panels 20 that are disposed over the concrete—which may be performed within ten minutes of pouring—can act as a barrier to the ambient environment. The less temperate the ambient conditions, the more beneficial the wet-setting method using the side panels 20 positioned over the wet concrete. For example, in hot conditions, the side panels 20 retard evaporation so that a slower “wet cure” of the concrete occurs and the formed tilt-up wall is stronger based on the curing process. Without using the side panels 20 of the present invention, either the moisture evaporates too quickly resulting in a structurally weaker concrete or, more typically, a sealing membrane or “retardant” is sprayed over the top of the fluid concrete after screeding and leveling—an expense that is not incurred using the wet-setting process of the present invention. Alternatively, if the ambient environment is cold (i.e., close to or below freezing conditions), the side panels 20 also facilitate curing by including an insulating layer. Without using the wet-setting process of the present invention, the prior art techniques have involved using tents with propane blowers, blanketing the top surface of the concrete, or heating the area around the poured tilt-up wall using other means known in the art. The present invention is advantageous because it avoids or reduces the labor, fuel, and equipment costs associated with heating the concrete as it cures. Another advantage of the wet-setting method is that irregularities in the upper surface of the concrete after pouring are acceptable. That is, the poured concrete should be leveled within plus or minus one quarter inch (±¼″) before placing the side panels 20 into the concrete. Accordingly, the process of using a power trowel, which is labor intensive and can be expensive, is most likely avoided. Therefore, the wet-setting method circumvents the need for curing compounds, power trowels or other surface finishing, and curing thermal blankets or other heating processes.
For the second method of forming the tilt-up walls shown generally in FIG. 8, the side panel 20 is horizontally-disposed so that the attachment points 44 extend upwardly (i.e., opposite to the orientation of the wet-setting embodiment). The interior surface 34 of the side panel 20 becomes the surface onto which concrete is poured. Perimeter forms (not shown) are placed around the of the periphery, namely, the top end 24 , bottom end 26 , first end 28 , and second end 30 of one side panel 20 or an array of side panels 20 , to prevent the fluid concrete from leaking off of the interior surface 34 . Furthermore, as discussed below if a connector 50 is used as a stanchion instead of other exemplary embodiments shown in FIG. 6, re-bar can be positioned within the apertures 56 to strengthen the tilt-up wall prior to pouring the concrete. Once the concrete is poured, leveled, and substantially cured, the forms are removed and the side panel 20 and substantially cured concrete slab C creates the tilt-up wall 10 . The second method of forming a tilt-up wall advantageously avoids use of a release agent. Also, one skilled in the art will appreciate that the term “a side panel” as used for the second and third designs may encompass multiple panels, including an array of panels discussed above for the first design.
The third method or design of forming the tilt-up wall repeats first steps used in the second design, namely, the side panel 20 is horizontally-disposed so that the attachment points 44 extend upwardly; perimeter forms are placed around the of the periphery of the side panel 20 ; and the concrete is poured. However, before the concrete cures to any substantial degree, another, second side panel 20 is wet set into the poured concrete, as occurs in the first design. Thus, the third method is a hybrid of the first two methods to create a wall 10 that, when substantially cured and tilted up, has the design shown in FIG. 2 A. As will be appreciated, the interior surfaces 34 of the opposed side panels 20 and the web members 40 disposed therein are spaced apart in a non-contacting relationship with each other so that the first and second side panels are stationarily positioned relative to each other by only the concrete slab C disposed within the cavity 38 . That is, unlike the first embodiment shown in FIG. 2, there are no connectors 50 or other components interconnecting the opposed side panels 20 .
This third method of making a tilt-up wall 10 has many advantages. When considered to prior art tilt-up walls, it encompasses the same advantages of both the first and second methods of forming a tilt-up wall, such as avoiding the need for (1) curing thermal blankets or other heating processes, (2) curing compounds, (3) power trowels or other surface finishing, and (4) a release agent. This third design also has greater insulating value and sound impedance than either of the first two designs since there are side panels 20 on each side of the concrete slab C, instead on only on one side.
The third embodiment also has potential advantages over the first embodiment of the present invention, which is shown in FIGS. 1 and 2, particularly if the wall being formed is greater than one story high. Most obviously, this dual-panel tilt-up wall form using the third design does not use connectors so there is a cost savings both by avoiding the purchase of these components and by not requiring the labor to install the connectors to interconnect the side panels. In addition, for a wall greater than one story high, the cost of external bracing and scaffolding during the wall assembly and pouring of concrete is not required. Since the panels 20 are laid flat during pouring of the concrete, there are minimal hydrostatic pressures compared to the panels being erected before pouring. As one skilled in the art will further appreciate, the practice of forming a wall as shown in the first embodiment typically involves filling in the cavities in four foot vertical increments, called lifts. The process of forming each lift is more labor intensive than filling the cavity continuously at a single horizontal location. Furthermore, it is imprudent—and prohibited by some building codes—to drop concrete more than ten feet because the constituents of the concrete tend to separate from each other, resulting in a weak final product. Thus, the usual practice in vertical-wall formation is to cut holes into the side panels at different elevational positions and then patch the holes after they are used as a filling port between the source of concrete and the cavity. This process of using the holes in the side panels, obviously, increases the labor costs and time required to fill the cavity for a wall greater than one story in height. The third design of the tilt-up wall, in comparison, avoids these problems and, accordingly, is quicker and less expensive to construct than the first embodiment of the dual-panel wall for wall structures greater than one story in height.
Regardless of the method used to form the tilt-up walls of the present invention, the side panels 20 —either with or without the stanchions connected—forge a bond with the concrete as it cures. Once the concrete C obtains sufficient strength for lifting (usually 2,500-3,000 psi) that is typically reached in five to ten days (depending on ambient conditions), a crane (not shown) or other means connects to cables (not shown) attached to embedded inserts cast into the tilt-up wall. The crane sequentially lifts each tilt-up wall and sets it on a prepared foundation around the building perimeter. FIG. 11 shows a single concrete structure 10 having been tilted up. Before any of the tilt-up walls are released by the crane, temporary braces (not shown) are installed-at least two per tilt-up wall—to brace up the respective tilt-up walls until the roof structure is attached.
Next, connections between individual tilt-up walls are made, which usually entail welding splices of steel ledger angles (not shown), and then the joints between the tilt-up walls (typically three-quarter inch (¾″)) are caulked. Also, any necessary patching is made to repair blemishes. Approximately the same time, the closure strip between the tilt-up walls and the floor slab (usually a two-foot-wide strip) is filled with concrete and the bracing is removed when the roof has been permanently connected to the tilt-up walls.
One of the advantages of using tilt-up walls 10 of the present invention is the shortened construction time. All of the steps discussed above in forming a building frame, from pouring the floor slab to erecting the tilt-up walls that are ready to receive the roof structure, often require only four weeks. Tilt-up walls are also generally less labor intensive to construct, which results in a financial savings. Moreover, tilt-up walls 10 of the present invention may be used to form multi-story buildings.
When considering the benefits of using the side panels 20 with tilt-up walls, one skilled will appreciate the improved insulation and sound impedance that exists using the side panels 20 , which would be difficult and expensive to install on a conventional tilt-up wall once erected. Also, the web members 40 , when set into the concrete and substantially cured, insure a substantially permanent, worry-free connection for the side panels 20 and provide a solid attachment point that may be used to connect wallboard such as sheet rock, brick, or stone finishes. Moreover, electrical and plumbing runs are easily installed within the side panels 20 . That is, installing electrical and plumbing is accomplished by cutting the “run's” using a hot knife, router, or electric chain saw into the side panel 20 of preferred embodiment, which is made of EPS. Also, using the preferred side panels 20 removes any potential metal contact problems and makes it much easier to connect pipes and wires compared to achieving the same with conventional tilt-up walls.
The tilt-up wall concrete structure 10 using a side panel 20 on only one side of the concrete slab C can also be used as an insulated concrete floor, in which the panels are formed and raised upwardly to form a floor of the building. Likewise, the structure 10 can also be used to create roof panels. Thus, the present invention can be used to construct the majority of an entire building, namely, the walls, floors/ceilings, and roof panels. Also of note, the side panels 20 do not affect the engineered structural design of the formed tilt-up wall as compared to not using the panels.
If the concrete or “slump” is dry or if ambient conditions are cold, the attachment points 44 —being rectangular and substantially flat and extending eleven-sixteenths ({fraction (11/16)}) of an inch from the interior surface 34 of the side panel 20 in the preferred embodiment—may have difficulty penetrating into the fluid concrete. The present invention, as mentioned above, includes stanchions or extending devices that assist in bonding the side panels 20 to the wet concrete. The primary function of the stanchions is to form better bonds between the concrete C and the side panel 20 . As such, the side panels 20 are less likely to separate from the concrete slab C of the tilt-up wall or other wall of the present invention throughout its life. A secondary function of the stanchions is to give greater structural integrity to the side panels 20 and associated wallboard, brick, or stone finishes attached to the end plates 42 of the web members 40 . That is, by being more firmly anchored, the concrete slab C provides a better connection to the side panels 20 and a stronger foundation for any materials hung from the side panels 20 . The stanchions are discussed in the specific context of a tilt-up wall but, as one skilled in the art will appreciate, the stanchions, for example, may also be useful in a dual-panel wall discussed above to buttress the connection between the side panel 20 and the concrete poured into the cavity 38 .
One specific embodiment of the stanchion comprises a connector 50 , for example, coupled to one attachment point 44 to increase the surface area to which the concrete C bonds. If the connectors 50 are the incorrect length, then they can easily be cut to the proper dimension at the construction site. The connectors 50 , as discussed above, are best shown in FIGS. 4 and 4A.
Two additional such stanchions are shown in FIG. 6, namely, an extender 60 and a tilt-up anchor 70 . First addressing the extender 60 , it includes a tip end 62 , an opposed base end 64 , and a body 66 extending therebetween. Preferably, the tip end 62 is of a size to complementarily engage one end 52 of a connector 50 and the base end 64 is of a size to complementarily engage one attachment point 44 . Similar to the preferred designs discussed above, the tip end 62 is preferably rectangular in plan view—as is the attachment point 44 —and the base end 64 preferably defines a track of a size to slidably receive a selected one of the tip end 62 or the attachment point 44 therein—as does one end 52 of the connector 50 . The locking means is preferably also part of the extender 60 and other stanchions.
The body 66 of the extender 60 is preferably non-smooth, which assists in bonding to concrete C. In the preferred embodiment, the body 66 defines a passage 68 20 therethrough. As will be noted by FIGS. 6 and 12, the passage 68 has a substantially rectangular cross-section. In the preferred embodiment, the width of the sides of the passage 68 is between one-quarter (¼) and one (1) inch to have a cross-sectional area between approximately 0.125 and 1 square inches, and more preferably between one-half (½) inch and three-quarter (¾) inch to have a cross-sectional area between approximately 0.25 and 0.57 square inches. This range of widths allows a portion of a flexible linking member 90 (shown in FIG. 12) to be received therethrough (as discussed below) as well as being of a dimension to allow fluid concrete to at least partially flow into the passage 68 for better bonding. Of course, other dimensions are contemplated to achieve these same functions and, in fact, the minimal dimension to allow fluid concrete to flow partially therein may be a function of the viscosity of the fluid concrete and size of the aggregate stone used. Likewise, other cross-sectional shapes for the passage 68 are also contemplated, such as circular, elliptical, triangular, or other polygonal shapes. As one skilled in the art will also appreciate, the body 66 of the extender 60 can be manufactured in different lengths, depending on the use of the extender 60 ; however, the preferred length between the tip end 62 and the base end 64 is approximately one inch.
Three functions of the extender 60 of the present invention are addressed herein: (1) as a stanchion; (2) as an extension for the connectors 50 ; and (3) as part of a connection between side panels 20 or to buttress the connection between panels 20 . The first listed function of extender 60 is the same as the other stanchions, which is to provide an additional surface to which the concrete can bond while curing to form a stronger connection with the side panel 20 . The extender 60 connects to one respective attachment point 44 of the web member 40 and extends into the concrete C a greater distance than the attachment point 44 . This longer extension, in and of itself, strengthens the bond between the concrete C and the side panel 20 to which the extender 60 is connected since there is more surface area to which the concrete C may bond during curing. Moreover, this bond is further strengthened by the extender 60 in the preferred embodiment having a non-smooth surface and, in the preferred embodiment, the non-smooth surface resulting in part from the passage 68 extending therethrough. As mentioned above, the passage 68 is preferably of a dimension to allow fluid concrete to at least partially flow therein, which enhances the bond with concrete C.
The second listed function of the extender 60 is to extend the reach of the connectors 50 . As discussed above, it is preferred to make the connectors 50 having lengths so that the width of the cavity 38 is two (2), four (4), six (6), eight (8) inches or greater. If, however, it is desired to have the width of the cavity 38 be three (3), five (5), or seven (7) inches, then the preferred embodiment of the extender 60 could be used to obtain that extra inch of separation.
Assume, for example, that the connector 50 shown in FIGS. 4 and 4A connects to the two attachment points 44 of opposed side panels 20 in the dual-panel embodiment (which is discussed above and shown in FIGS. 1 and 2) to form a cavity 38 that is two inches wide. To increase the width of the cavity 38 to be three inches wide, the preferred extender 60 is used in conjunction with the connector 50 shown in FIG. 4 or FIG. 4 A. That is, the tip end 62 of the extender 60 is preferably formed to be the same dimensions as an attachment point 44 of the web member 40 so that the tip end 62 can be slidably received into the track 54 at one end 52 of the connector 50 , similar to the attachment point 44 being slidably received into the end 52 of the connector 50 . The base end 64 of the extender 60 , in conjunction, preferably forms a track into which one attachment point 44 of a web member 40 is slidably received (i.e., the same dimension as the track 54 of the connector 50 shown in FIG. 4 or FIG. 4 A). Accordingly, the connector 50 is coupled to the attachment point 44 of one side panel 20 , the base end 64 of the extender 60 is coupled to the attachment point 44 of the opposed side panel 20 , and the connector 50 is attached to the tip end 62 of the extender 60 so that a three-inch wide cavity 38 is formed between two opposed side panels 20 , instead of a two-inch cavity if the connector 50 shown in FIG. 4 or FIG. 4A was used alone. Thus, in the preferred embodiment, for each extender 60 added between the connector 50 and the attachment point 44 , the extender 60 advantageously allows the cavity 38 to be extended one inch in width. As such, the extender 60 can be used to meet this need to have an irregularly sized cavity without requiring the manufacturer to mold special new connectors, which would be an expensive endeavor. As one skilled in the art will appreciate, the extender 60 can have a length other than one inch, if desired.
The third potential function of the extender 60 is to establish or to buttress the connection between side panels 20 . One example in which the extender 60 is beneficial when one wall or panel is at a non-parallel angle to another wall or panel, often being disposed at right angles to form a T-wall in top plan view. Since concrete has to be poured into the cavity 38 defined by the side panels 20 that are not oriented parallel to each other (as exists in FIG. 2 ), the normally linear connectors 50 shown in FIGS. 4 and 4A cannot feasiblely be used. As one skilled in the art will appreciate, although within the scope of the present invention, manufacturing non-linear connectors would be expensive and often not be viable for a large percentage of construction projects.
In conjunction, one problem with constructing such a T-wall is that when the concrete is poured into the cavity 38 , pressures against the abutting side panel 20 (i.e., at the top of the “T”) forces the side panel outwardly. The prior art solution is to brace the wall on the exterior surface 32 of the side panel 20 using, for example, lumber braces. The braces, however, are difficult and labor intensive to construct, particularly when used on multistory building above the first or ground floor.
Referring now to FIG. 12, the extender 60 , used with a flexible linking member 90 , such as a zip-tie, plastic tie strap, tie wire, or other similar component, provides an easy and effective solution to buttress a connection between side panels 20 , particularly for situations in which the respective interior surfaces 34 are not parallel to each other. Although not required, it is preferred that the flexible linking member 90 be contiguous and connect to itself in by forming a closed loop, in which the looped linking member 90 interconnects the opposed side panels 20 .
For one design shown at the top of FIG. 12, respective extenders 60 are connected to attachment points 44 formed on different side panels 20 . That is, in this design there are two extenders: a first extender 60 connected to the attachment point 44 of one web member 40 partially disposed within a first panel 20 and a second extender 60 connected to the attachment point 44 of one web member 40 partially disposed within the opposed second panel 20 . A portion of the flexible linking member 90 , in conjunction, traverses through the passage of the first extender 60 and a portion of the flexible linking member 90 also traverses through the passage of the second extender 60 . The flexible linking member 90 is connected through the respective passages of two extenders 60 and tightened, thereby securely interconnecting the spaced-apart panels 20 .
In another embodiment, it is also contemplated that at least one of the two web members 40 defines a slot 41 extending therethrough. The slot 41 is preferably located adjacent the interior surface 34 of the first panel in which the web member 40 is disposed and preferably integrally formed with the web member 40 . The slot 41 is also preferably of a size to receive a portion of the flexible linking member 90 therein.
Thus, as shown at the bottom of FIG. 12, a portion of the flexible linking member 90 traverses through the slot 41 of one web member 40 and also traverses through the extender 60 connected to the attachment point 44 of the other web member 40 to interconnect the spaced-apart panels 20 . In still another embodiment shown at the middle of FIG. 12, a portion of the flexible linking member 90 traverses through the slot 41 of one web member 40 and the slot 41 of the other web member 40 to interconnect the spaced-apart panels 20 . The three illustrated embodiments shown in FIG. 12, of course, may be used independently of each other.
Similarly, the extender 60 with the flexible linking members 90 can be used anywhere on the side panels 20 where there may be weakness in the structure. As an example, weakness may exist where a cut-up design is used or the wall zig-zags. As another example, weakness may also occur wherever quick turns are used in the layout of the side panel 20 . In these situations, the extenders 60 and interconnecting flexible 15 linking members 90 may be used in lieu of external bracing. Although not preferred, it is also contemplated that the flexible linking member 90 —in concert with the passages 68 of extenders 60 or the slots 41 formed into the web members 40 —may interconnect opposed side panels 20 in the first embodiment (shown, for example, in FIGS. 1 and 2 ), instead of using connectors 50 to interconnect the side panels 20 .
In comparison to the extender 60 , another design of the stanchion, the anchor 70 , is also shown in FIG. 6 and is less broad in its potential functional uses. The primary purpose of the anchor 70 is to strengthen the bond between the side panel 20 and the adjacent concrete once that concrete has substantially cured. The preferred anchor 70 has a forward end 72 , an opposed back end 74 , and a body 76 extending therebetween. The back end 74 is preferably of a size to complementarily engage one attachment point 44 .
Also, it is preferred that the body 76 has at least one prong 78 extending from it and, more preferably, two prongs 78 oriented co-linearly to each other. However, as one skilled in the art will appreciate, other permutations also fall within the scope of the present invention, such as three or more prongs 78 or two prongs 78 not oriented co-linearly. The presently preferred prongs 78 have a length of a half (½) inch to one (1) inch and a generally round cross-sectional shape that has a diameter of one quarter (¼) inch. One skilled in the art, however, will appreciate that wider range of values are possible for the prongs 78 —the important consideration being that the prongs 78 not break when fluid concrete flows past the anchor 70 during the construction process or after substantial curing. Also, the prongs 78 can be integrally formed to the anchor 70 or coupled thereto using any means known in the art.
Returning to the presently preferred embodiment of two co-linear prongs 78 , it is preferred that when the anchor 70 is connected to the attachment point 44 , the two prongs 78 form an angle that is not perpendicular or normal to a plane formed by the interior surface 34 of the side panel 20 (and also the plane formed by the exterior surface of the concrete C on the tilt-up wall). In fact, it is most preferred that the two prongs 78 extend parallel to the plane formed by the interior surface 34 of the side panel 20 to which the anchor 70 is attached, an angle which is generally perpendicular to the direction that the anchor 70 extends between its forward and back ends 72 , 74 when connected to the attachment point 44 . This angular orientation of the prongs 78 provides increased bonding strength with the concrete C.
Although it is presently preferred that there is at least one prong 78 , the present invention contemplates that no prongs be included; instead, the body 76 of the anchor 70 can be of a non-smooth or non-linear shape to bond with the fluid concrete that flows around the body 76 . One contemplated design includes a generally mushroom shape that is narrow at the back end 74 and flares outwardly moving toward the forward end 72 . Other contemplated designs include the forward and back ends 72 , 74 being wider in side view than the intervening portion of the body 76 so that the body appears similar to a chef's hat or an hourglass in side view. Of course, symmetry is not required in any of these alternative embodiments. As one skilled in the art will appreciate, one important consideration is that the fluid concrete be able to flow around the anchor 70 to improve bonding after the concrete substantially cures.
Although the length of the connector 50 , extender 60 , or anchor 70 used as a stanchion between the interior surface 34 of the side panel 20 and the tip of the stanchion may be any dimension shorter than the thickness of the concrete portion of the tilt-up wall, the preferred embodiment uses a length of one inch (1″) or less. The reason for using a length shorter than the possible maximum length is that a longer stanchion would potentially interface with the re-bar or other structural support within the tilt-up wall. That is, either by convention or as required by applicable building code requirements, the re-bar is usually placed one inch or more away from either surface of the tilt-up wall so that the ends of the respective stanchions, extending the maximum of one inch, will not interface with or contact the re-bar, which could impede the proper setting of the side panels 20 into the fluid concrete.
As with the connectors 50 , the other embodiments of the stanchions are preferably formed of a high-density plastic, such as high-density polyethylene or polypropylene, although other polymers can be used as noted above. Advantages of the high-density plastics for the stanchions include cost of manufacturing, strength, rigidity when the component is sufficiently thick, and the like.
As one skilled in the art will also appreciate, the stanchions are not necessary for the present invention to function and, in fact, may not even be desired if the concrete is very “wet” or a plasticizer has been added to the concrete in the context of constructing tilt-up walls. If stanchions are used, it is contemplated using one stanchion per web member 40 connected to the center attachment point 44 (i.e., the middle attachment point 44 shown in FIG. 6 ); however, it is also contemplated using up to and including one stanchion on each attachment point 44 (i.e., five stanchions used on every web member in the embodiment shown in FIG. 6 ).
Referring now to FIGS. 9 and 9A, the third embodiment of the present invention is analogous to the first embodiment because a cavity is formed into which concrete is poured. However, instead of the formed concrete structure having opposed side panels each connected to the concrete portion as in the first embodiment shown in FIGS. 2 and 2A, this embodiment preferably uses a side panel 20 on only one side of the formed concrete structure 10 . That is, the formed concrete structure 10 is similar to the tilt-up wall discussed above (i.e., a concrete slab C with side panels 20 positioned only on one side), but is made using a different construction process.
More specifically and as best shown in FIG. 9, the third embodiment uses a side panel 20 and an opposed sheet 80 to form the cavity 38 into which the concrete is poured. That is, in forming the wall 10 , the process involves positioning the side panel 20 and the sheet 80 substantially upright so that a portion of the interior surface 34 of the side panel 20 faces a portion of an inside surface 82 of the sheet 80 . The interior surface 34 and the inside surface 82 are laterally spaced apart from each other so that a cavity 38 is formed therebetween, just as occurs in the first embodiment using spaced-apart side panels 20 .
The sheet 80 is preferably plywood, but can be any solid material that can be coupled to either a web member 40 or a connector 50 and can withstand the forces exerted by the fluid concrete when poured into the cavity 38 without substantial bowing, warping, breaking, or other type of failure. Other contemplated materials include combined steel frame and plywood center, commonly known as a steel-ply panel. Accordingly, the sheet 80 functions as a form or barrier while the concrete is curing.
The process next involves attaching one end 52 (“the first end”) of the connector 50 to the attachment point 44 of the side panel 20 and connecting a portion of the inside surface 82 of the sheet 80 to the other end 52 (“the second end”) of the connector 50 . However, it may be a matter of preference for the order of construction so the first end of the connector 50 may be attached to the attachment point 44 before positioning the sheet 80 or the sheet may be positioned before the first end of the connector 50 is attached to the attachment point 44 .
The sheet 80 can be either directly or indirectly coupled to the connector 50 . That is, referring back to FIG. 3, there are two options for the second or “free end” of the connector 50 , which is the end not attached to the web member 40 located within the side panel 20 . First, for the indirect connection and as shown in FIG. 9, the free end can be connected to, for example, a stand-alone web member 40 ′, which is a web member that is not formed within a side panel 20 and is illustrated in FIGS. 3, 6 , 9 , and 10 . The sheet 80 is then connected to the end plate 42 of the stand-alone web member 40 ′, instead of being directly connected to the second end of the connector. This indirect connection forms the preferred embodiment.
FIG. 3 shows only one stand-alone web member 40 ′ that is attached to the connectors 50 . As one skilled in the art will appreciate, however, multiple web members 40 are preferably used when preparing the wall structure 10 (i.e., between two and six stand-alone web members 40 ′ used for the side panel 20 shown in FIG. 3 based on there being six web members 40 located within the side panel 20 ). It is, of course, preferred to use a sufficient number of web members to withstand the dynamic and static forces that exist when the fluid concrete is poured into the cavity (i.e., preferably six for the side panel 20 shown in FIGS. 3 and 9 ).
Alternatively and less preferred, the sheet 80 may be connected directly to the second or free end of the connector 50 . Still referring to FIG. 3, four connectors 50 are shown in this configuration (i.e., connected to the web member 40 located within the side panel 20 but not connected to a stand-alone web member 40 ′). Thus, unlike the indirect connection having an intervening stand-alone web member 40 ′ or other component, the sheet 80 in this design is directly coupled to the second ends of the connectors 50 . The potential drawback with this design is that it is more difficult to attach or couple the sheet 80 to the connectors 50 at the construction site. However, if the free end of the connectors 50 is formed with more surface area than included in the illustrated embodiments, this potential drawback may be reduced.
It is also contemplated using connectors 50 that are integrally attached to or formed with the web members 40 located in the side panels 20 for the third embodiment (as well as other embodiments). Stated differently, the connectors 50 and web members 40 may be a unitary structure and, as such, the attachment points 44 in his contemplated design extend a distance from the interior surface 34 of the side panel 20 to the attachment points 44 that is substantially equivalent to the desired thickness of the cavity 38 for the direct connection process. Thus, the step of attaching the connectors 50 to the attachment points 44 of the web members 40 disposed within the side panels 20 is avoided because the inside surface 82 of the sheet 80 is attached directly to the attachment point 44 to form the cavity 38 . Alternatively, the extended attachment points 44 may be designed to connect to the stand-alone web member 40 ′ or similar structure is using the indirect connection method. However, this design of integrally forming the connectors 50 to the attachment points 44 has a potential drawback of the increased space needed to transport a given quantity of side panels 20 to the construction site if the web members 40 are integrally formed into the side panels 20 , as opposed to being inserted through precut slots at the construction site.
Regardless of the component to which the sheet 80 is connected, it is preferred that the sheet be detachably connected, or removably attached, to the second end of the connector 50 or stand-alone web member 40 ′. By being detachably connected, the present invention entails that the sheet 80 can be removed from the end plate 42 or connector 50 substantially intact, preferably so that the sheet can be reused to form another concrete structure. Many means are contemplated for detachably coupling the sheet 80 to the end plate 42 or connector 50 , such as using a nail or screw. One skilled in the art will appreciate that this list is not exhaustive and can include other coupling means such as chemical adhesives, rivets, tacks, nuts and bolts, and the like.
Once the sheet 80 and side panel 20 are interconnected and stationarily positioned relative to each other, the process of forming the structure 10 involves pouring fluid concrete into the cavity 38 and allowing the concrete to substantially cure to form a concrete slab C. The formed concrete structure 10 is shown in FIG. 9 A. In the preferred embodiment, after the concrete substantially cures (which may take about three days depending on ambient conditions and the thickness of the cavity 38 ) the process involves removing the sheet 80 from the concrete slab C to expose a portion of the concrete slab C to atmosphere, which is shown in FIG. 11 . That is, after substantially curing, the sheet 80 is preferably removed leaving a concrete structure 10 that has a side panel 20 disposed on one side and concrete C exposed to ambient or atmosphere on the other, opposed side. The sheet 80 is also preferably reusable for forming another wall. However, although not preferred, it is contemplated having the sheet 80 remain a permanent part of the tilt-up structure 10 as shown in FIG. 9 A.
A potential aesthetic drawback with the above process is that when the sheet 80 is removed, the exposed surface will be predominately concrete C with the end plates 42 or the ends 52 of the connectors 50 recurrently showing on the exposed concrete surface. To avoid this non-contiguous appearance and as shown in FIG. 10, the present invention also contemplates using a spacer 84 attached or permanently affixed to the end plate 42 of the stand-alone web member 40 ′ or to one end 52 —the free or second end—the connectors 50 . The spacer 84 is to be disposed in a contacting relationship with the inside surface 82 of the sheet 80 .
Referring now to FIG. 10, one embodiment of the spacer 84 is cone-shaped in side view, in which the narrow end is attached or coupled to the end plate 42 of the stand-alone web member 40 ′ or the end 52 of the connector 50 and preferably extends between a quarter and three-quarter (¼-¾) inches, more preferably one-half (½) inch. The cone-shaped spacers may also be inverted so that the wide end is attached to the end plate 42 . It is also contemplated that the cone-shaped spacer 84 has openings or slots extending between the narrow end and the wide end. Other shapes are contemplated for the spacer 84 , such as circular, elliptical, or rectangular shapes in plan view. It is also contemplated having the spacer 84 use a constant cross-sectional area along its length, instead of being cone shaped.
The sheet 80 is mounted to abut the wide end of the spacer 84 and the screw—if used as the coupling means—traverses through the sheet 80 , spacer 84 , and then into and through a portion of either the end plate 42 of the stand-alone web member 40 ′ or end 52 of the connector 50 . If the wide end of the spacer 84 is attached to the end plate 42 , then the coupling means need not traverse through the interior of the spacer, which may be easier at the construction site because less precise aligning is required. If the spacer 84 has openings, at least some concrete may enter into its internal volume when the cavity 38 is filled with concrete.
Using the spacers 84 , after the concrete substantially cures and the sheet 80 is removed, the interior volume of the spacer 84 is exposed so that there are only small portions of the concrete surface in which the concrete C is not contiguous on the face of the structure 10. However, since the preferred spacer 84 is cone-shaped, a finish coat of cementitious material, including concrete, a parging coat, or stucco, can quickly be spread into the interior volume of the spacers so that when it cures, the exposed face of the concrete structure 10 appears as a uniform concrete surface, as opposed to having the ends 52 of the connectors 50 or the end plates 42 exposed.
One skilled in the art will appreciate that a uniform concrete appearance obtained using the spacers 84 is more aesthetically appealing if the exposed surface of the concrete structure remains exposed when the building is completed. However, if it is desired to mount materials such as drywall or masonry tiles directly onto the surface originally covered by the sheet 80 , not using the spacers 84 may be preferred. That is, the exposed end plates 42 of the stand-alone web members 40 ′ or the ends 52 of the connectors 50 facilitate attaching materials to the concrete surface because it is easier to connect materials to these members, compared to attaching the materials to the cured concrete C. Also, if the entire exposed concrete surface will be coated with stucco or the like, then depending on the bonding properties of the coating, it may be irrelevant whether the spacers 84 are used.
Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims.
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An insulated concrete structure including a side panel, a spaced-apart sheet such as plywood, and concrete disposed therebetween. The concrete is poured into a cavity formed between the side panel and the sheet and allowed to substantially cure, after which time the sheet can remain as part of the structure or be removed and used again in forming another concrete structure. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. § 1.72(b).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/864,768, filed Aug. 12, 2013, the contents of which are incorporated by reference herein.
BACKGROUND INFORMATION
[0002] Therapeutic agent (e.g. drug) delivery is an important aspect of medical treatment since the efficacy of a drug is directly related to its administration. Some therapies require repetitive drug administration to the patient over a long period of time, and in many cases long term consistent administration of drug is desirable. In addition, patient compliance with repetitive, long term drug administration can be an issue in some instances.
[0003] Considerable advances have been made in the field of drug delivery technology over the last three decades, resulting in many breakthroughs in clinical medicine. The creation of therapeutic agent delivery devices that are capable of delivering therapeutic agents in controlled ways still presents many challenges. One of the significant requirements for an implantable drug delivery device is controlled release of therapeutic agents, ranging from small drug molecules to larger biological molecules. In many instances, it is particularly desirable to achieve a continuous drug release profile whereby the concentration of drug in the bloodstream remains substantially constant throughout an extended delivery period. It can also be desirable for the implantable drug delivery device to provide continuous drug release via passive control mechanisms to minimize device complexity.
[0004] These devices have the potential to improve therapeutic efficacy, diminish life-threatening side effects, improve patient compliance, minimize the intervention of healthcare personnel, reduce the duration of hospital stays, and decrease the diversion and abuse of controlled substances.
[0005] By providing a more consistent release, it is possible to improve the therapeutic efficacy and simultaneously decrease the side effects (e.g. toxicity of temporary overdosing or diminished activity associated with a small drug concentration in the plasma) associated with multiple administrations of higher dosages.
[0006] The solubility of certain therapeutic agents can provide dosing and application challenges. For example, a therapeutic agent with poor water solubility requires a greater volume of solvent to dissolve the therapeutic agent in the injection or implantable delivery device in order to provide an effective dosing level for extended duration. In cases where it is desirable to have an extended dosing period, the volume of solvent and the dissolved therapeutic agent may be large, and therefore the implantable delivery device may be prohibitively large. Long term dosing of low solubility therapeutic agents in a small implantable delivery device is desirable.
[0007] In certain applications, implantable drug delivery devices may incorporate geometric constraints to provide for a controlled release rate of the therapeutic agent. For example, certain implantable drug delivery devices may utilize nanochannels to restrict the rate at which therapeutic molecules can diffuse from the device. In particular applications, geometric constraints can control the diffusion rate so that it is substantially independent of the concentration of the remaining therapeutic agent within the delivery device. These geometric constraints include nanochannels that are fabricated 2-5 times larger than the hydrodynamic size of the agent molecule. However, if the therapeutic molecule is sufficiently small, it can be difficult, if not impossible, to create a geometric constraint dimensioned to provide for a controlled release rate at a therapeutically-effective level. In addition, such small geometric constraints may lead to insufficient release of the agent.
[0008] The issues raised above are merely exemplary of the potential shortcomings of existing systems and are not intended to be an exhaustive listing of the issues addressed by embodiments of the present disclosure.
SUMMARY
[0009] Devices have recently been developed to address some of the issues described above. However, it was until recently believed that the environment within an implantable device should approximate the surrounding physiologic environment outside the device in order to facilitate administration of a therapeutic agent from the device. For example, previous efforts for therapeutic agent administration attempted to match the saline concentration of fluid inside the device to that of the outside environment in order to minimize boundary layers between the two environments and promote molecular diffusion of the therapeutic agents from the implantable device to the outside environment.
[0010] Recent efforts have discovered that in certain instances solubilizers within the device that do not approximate the surrounding environment can be successfully utilized. For example, certain oils have been found to effectively solubilize testosterone and testosterone esters to provide effective testosterone replacement therapy. It was previously believed that many oils would be effective at solubilizing therapeutic agents (including testosterone), but would not be effective at delivering the therapeutic agents to the patient. It is well known that oils are not miscible with water. This surprising result contradicted prevailing scientific understanding and literature publications which held that the boundary layer between the oil and saline environment would restrict or prevent a therapeutic agent from being effectively administered.
[0011] Exemplary embodiments of the present invention, however, utilize a therapeutic agent dissolved in a solubilizer that has relatively low miscibility with the outside environment in a reservoir of an implant that comprises channels to assist in controlling the release rate of the dissolved therapeutic agent. In particular embodiments, the implant may comprise nanochannels and/or microchannels.
[0012] In particular embodiments, the solubilizer may comprise one or more of the following: Gelucire 44/14, Gelucire 50/13, Peceol, Labrafil M2125 CS, Labrafil M1944 CS, Labrasol, Tween 80, Crodasol, Brij 30, Glycerox 767, NOVOL (Oleyl Alcohol), ETOCAS (PEG-35 Castor Oil), Arlosolve (Dimethyl lsosobride), PEG300, Maisine 35-1, Transcutol HP, Glycerin, Span 80, Span 85, Compritol 888, Propylene Glycol, Dibutyl Sebacate, Triacetin, Miglyol 810, Miglyol 812, Myvacet, Softigen 701, Softigen 767, Kolliphor HS15, Kolliphor RH40, Kolliphor ELP, Stearic Acid, Cetyl Palmitate, Lauroglycol 90, Lauroglycol FCC, Labrafac PG, Labrafac Lipophile WL 1349, Miranol, Soybean Oil, Corn Oil, Olive Oil, Castor Oil, Sesame Oil, Light Mineral Oil, Heavy Mineral Oil, Coconut Oil, Canola Oil, Dimethyl Sulfoxide (DMSO), N-Methylpyrrolidone (NMP), Benzyl Benzoate, Capryol 90, Capryol PGMC, Glyceryl Monostearate, Vitamin E TPGS and Benzyl Alcohol. This list is exemplary, and other appropriate solubilizers, cationic, anionic and nonionic surfactants, fatty acid esters, fatty acid alcohols, and other substances singularly or in combination known to those skilled in the art to enhance the aqueous solubility or provide for highly concentrated, low water miscibility suspensions of a target therapeutic agent within the device may be used. In specific embodiments, the solubilizer may be non-aqueous.
[0013] The inclusion of a concentrated therapeutic agent dissolved in a solubilizer within the reservoir can address several issues noted in existing systems. For example, portions of the solubilizer (with the dissolved therapeutic agent) that are small enough to pass through the channels can separate over time and be released to provide a more steady concentration of therapeutic agent. By providing a more steady concentration, rather than a concentration that is initially high and subsequently reduced (as might be the case for therapeutic agent delivery outside the constrained reservoir), the geometry of the delivery device can be optimized. For example, it may be possible to increase the size of the channels because the concentration of the reservoir is maintained at a more steady level by the presence of the non-miscible therapeutic agent, so less geometric constraint is required. Also, one or more dimensions of the portions of the solubilizer (with the dissolved therapeutic agent) that break away can be tens or hundreds of nanometers, so that channeled members with geometrics constraints, e.g., nanochannels having dimensions the size range 50 to 250 nanometers, can regulate the release of these portions.
[0014] The use of a therapeutic agent dissolved in a solubilizer may also make it possible to administer therapeutic agents that would otherwise be difficult to administer consistently at therapeutic levels with a variable-concentration reservoir and a channeled member.
[0015] Exemplary embodiments of the present disclosure comprise an implantable device comprising a reservoir, a channeled member in fluid communication with the reservoir; and a compound comprising a therapeutic agent and a solubilizer disposed within the reservoir and in fluid communication with the channeled member.
[0016] Certain embodiments may include a device for administering a therapeutic agent, where the device comprises: an implantable device comprising a reservoir; a channeled member in fluid communication with the reservoir; and a compound comprising the therapeutic agent and a solubilizer disposed within the reservoir and in fluid communication with the channeled member.
[0017] In specific embodiments the compound may comprise testosterone or a testosterone ether, ester, or salt. In particular embodiments, the compound may comprise testosterone enanthate, testosterone cypionate, testosterone propionate, testosterone decanoate, and/or methyltestosterone. In certain embodiments, the solubilizer may comprise an oil. In particular embodiments, the solubilizer may be non-aqueous.
[0018] In specific embodiments, the solubilizer may comprise at least one of: Gelucire 44/14, Gelucire 50/13, Peceol, Labrafil M2125 CS, Labrafil M1944 CS, Labrasol, Tween 80, Crodasol, Brij 30, Glycerox 767, NOVOL (Oleyl Alcohol), ETOCAS (PEG-35 Castor Oil), Arlosolve (Dimethyl lsosobride), PEG300, Maisine 35-1, Transcutol HP, Glycerin, Span 80, Span 85, Compritol 888, Propylene Glycol, Dibutyl Sebacate, Triacetin, Miglyol 810, Miglyol 812, Myvacet, Softigen 701, Softigen 767, Kolliphor HS15, Kolliphor RH40, Kolliphor ELP, Stearic Acid, Cetyl Palmitate, Lauroglycol 90, Lauroglycol FCC, Labrafac PG, Labrafac Lipophile WL 1349, Miranol, soybean oil, corn oil, olive oil, castor oil, sesame oil, light mineral oil, heavy mineral oil, coconut oil, canola oil, dimethyl sulfoxide (DMSO), N-Methylpyrrolidone (NMP), Benzyl Benzoate, Capryol PGMC, Glyceryl Monostearate, Vitamin E TPGS and Benzyl Alcohol.
[0019] In certain embodiments, the channeled member may comprise a nanochannel. In specific embodiments, the nanochannel may have a dimension of up to 50 nm, or have a dimension in the range of 50-100 nm; 100-150 nm; 150-170 nm; 170-190 nm; 190-210 nm; 210-225 nm; 225-240 nm; or 240-250 nm. In particular embodiments, the channeled member may comprise microchannels. In certain embodiments, the device may comprise an injection port and/or a vent.
[0020] Specific embodiments include a method of administering a therapeutic agent, where the method may comprise: inserting a device as disclosed herein into an area of a human or animal anatomy (where the device comprises: a reservoir; a channeled member in fluid communication with the reservoir; and a compound comprising the therapeutic agent and a solubilizer disposed within the reservoir and in fluid communication with the channeled member); and releasing at least a portion of the therapeutic agent from the device into the area of the human or animal anatomy.
[0021] In certain embodiments of the method, the device may be configured to release the therapeutic agent at a substantially constant release rate for a dosage period of at least one week, of at least one month, of at least six months, or of at least one year.
[0022] In specific embodiments of the method, the compound may comprise testosterone or a testosterone ether, ester, or salt. In particular embodiments of the method, the compound may comprise testosterone enanthate, testosterone cypionate, testosterone propionate, testosterone decanoate, and/or methyltestosterone. In certain embodiments of the method, solubilizer may comprise an oil. In particular embodiments of the method, the solubilizer may be non-aqueous.
[0023] In specific embodiments of the method, the solubilizer may comprise at least one of: Gelucire 44/14, Gelucire 50/13, Peceol, Labrafil M2125 CS, Labrafil M1944 CS, Labrasol, Tween 80, Crodasol, Brij 30, Glycerox 767, NOVOL (Oleyl Alcohol), ETOCAS (PEG-35 Castor Oil), Arlosolve (Dimethyl lsosobride), PEG300, Maisine 35-1, Transcutol HP, Glycerin, Span 80, Span 85, Compritol 888, Propylene Glycol, Dibutyl Sebacate, Triacetin, Miglyol 810, Miglyol 812, Myvacet, Softigen 701, Softigen 767, Kolliphor HS15, Kolliphor RH40, Kolliphor ELP, Stearic Acid, Cetyl Palmitate, Lauroglycol 90, Lauroglycol FCC, Labrafac PG, Labrafac Lipophile WL 1349, Miranol, soybean oil, corn oil, olive oil, castor oil, sesame oil, light mineral oil, heavy mineral oil, coconut oil, canola oil, dimethyl sulfoxide (DMSO), N-Methylpyrrolidone (NMP), Benzyl Benzoate, Capryol PGMC, Glyceryl Monostearate, Vitamin E TPGS and Benzyl Alcohol.
[0024] In certain embodiments of the method, the channeled member may comprise a nanochannel. In specific embodiments, the nanochannel may have a dimension of up to 50 nm, or have a dimension in the range of 50-100 nm; 100-150 nm; 150-170 nm; 170-190 nm; 190-210 nm; 210-225 nm; 225-240 nm; or 240-250 nm. In particular embodiments of the method, the channeled member may comprise microchannels. In certain embodiments of the method, the device may comprise an injection port and/or a vent.
[0025] In the following, the term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0026] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 10%. The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.”
[0027] The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
[0028] The term “channeled member” as used herein includes structures comprising microchannels and/or nanochannels, including not limited to, any of the exemplary nanochannel devices disclosed in U.S. patent application Ser. No. 12/618,233 filed Nov. 13, 2009 (U.S. Patent Publication 20100152699) and entitled “Nanochanneled Device and Related Methods” and International Patent Application Number PCT/US10/30937 (WIPO Patent Publication WO/2011/146699) filed Apr. 13, 2010 and entitled “Nanochanneled Device and Method of Use”, both of which are incorporated herein by reference.
[0029] The term “microchannel” is defined as a channel with a cross-section having at least one dimension (e.g. height, width, diameter, etc.) that is greater than 500 nm and less than 50 μm.
[0030] The term “nanochannel” is defined as a channel with a cross-section having at least one dimension (e.g. height, width, diameter, etc.) that is less than 500 nm.
[0031] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0032] FIG. 1 is a graph that illustrates a plasma drug concentration over time when the drug is administered via traditional intravenous (IV) methods.
[0033] FIG. 2 is a graph that illustrates a plasma drug concentration over time when the drug is administered via a therapeutic agent and solubilizer in an implantable delivery device.
[0034] FIG. 3 is a top perspective view of an implantable delivery device.
[0035] FIG. 4 is a bottom perspective view of an implantable delivery device.
[0036] FIG. 5 is a section view of the embodiment of FIG. 3 .
[0037] FIG. 6 is a scanning electron microscope (SEM) cross-section image of a portion of a channeled member of FIG. 3 .
[0038] FIG. 7 is a scanning electron microscope (SEM) cross-section image of a portion of a channeled member of FIG. 3 .
[0039] FIG. 8 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member in combination with sesame oil and Labrasol.
[0040] FIG. 9 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member in combination with sesame oil.
[0041] FIG. 10 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member in combination with Vitamin E TPGS.
[0042] FIG. 11 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member in combination with sesame oil and benzyl alcohol.
[0043] FIG. 12 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member.
[0044] FIGS. 13-21 are graphs of a cumulative release rate of testosterone enanthate (TE) from a channeled member of with nanochannel heights of 160 nm, 190 nm, 200 nm, 210 nm, 220 nm, and 250 nm, and with and without a hydrophilic surface treatment included.
[0045] FIG. 22 is a graph of a concentration of testosterone serum in vivo.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0046] As previously mentioned, a more constant drug administration can provide numerous advantages over periodic administrations that are initially above the therapeutic range and subsequently diminish to below the therapeutic range. Referring to FIG. 1 , a graph illustrates plasma drug concentration versus time in one example of a typical conventional drug administration utilizing period dosage. As illustrated in FIG. 1 , the drug concentration is initially significantly above the therapeutic range and subsequently reduces to a level below the therapeutic range. When the concentration is reduced to a level below the therapeutic range, another dosage can be administered and the drug concentration again exceeds the therapeutic range before being reduced into the desired therapeutic range.
[0047] FIG. 2 shows the plasma drug concentration (PDC) over time when the drug is administered via a solid matter therapeutic agent in an implantable delivery device, as described in more detail below. The employment of a solid matter therapeutic agent in an implantable delivery device for constant drug release can improve the efficacy of the treatment. In addition it can avoid frequent injections and, in many cases, reduce or solve the issues of patient compliance.
[0048] Referring now to FIGS. 3-5 , an implantable delivery device (IDD) 100 is shown in perspective views ( FIGS. 3 and 4 ) and a sectional view ( FIG. 5 ). It is understood that the figures shown are not to scale and are intended for representative purposes only. In this embodiment, IDD 100 comprises a reservoir 110 with a channeled member 130 . In the exemplary embodiment shown, IDD 100 also comprises an injection port 140 , a vent 145 and exit ports 150 . In particular embodiments, the injection port 140 and vent port 145 are filled with a substance, for example, silicone rubber, and the channeled member 130 is in fluid communication with the exit ports 150 . In particular embodiments, IDD 100 may be formed from suitable bio-compatible materials including for example Polyether ether ketone (PEEK) or titanium.
[0049] In particular embodiments, channeled member 130 may comprise microchannels, and in specific embodiments, channeled member 130 may comprise nanochannels. Channeled member 130 may also comprise both microchannels and nanochannels in certain embodiments. In some embodiments, channeled member 130 may be an integral component of IDD 100 , while in other embodiments, channeled member 130 may be a separate component that is coupled to or inserted into IDD 100 . In particular embodiments, channeled member 130 may have a surface area of less than 1 cm 2 exposed to reservoir 110 , and in specific embodiments may comprise a surface area of approximately 0.75 cm 2 exposed to reservoir 110 . In certain embodiments, channeled member 130 may be approximately 6 mm×6 mm.
[0050] In particular embodiments, channeled member 130 may be equivalent to the nanochannel delivery device (and may be constructed via the associated methods) disclosed within in U.S. Patent Publication 20100152699, incorporated herein by reference. In other embodiments, channeled member 130 may comprise microchannels without nanochannels. In certain embodiments, channeled member 130 may comprise one or more coatings compatible with in vivo use, including for example, coating as described in U.S. Patent Publication 20110288497. Referring now to FIGS. 6 and 7 , scanning electron microscope (SEM) images of a portion of a channeled member are shown after in vivo testing without a coating ( FIG. 6 ) and with a coating ( FIG. 7 ).
[0051] In exemplary embodiments, reservoir 110 can be filled with an active pharmaceutical ingredient (API) 200 dissolved in a solubilizer 210 . In particular embodiments, API 200 may comprise, for example, testosterone or a testosterone ester and solubilizer 210 may comprise one or more of the compounds listed above in the Summary section of this disclosure.
[0052] During use, IDD 100 can be used to administer API 200 by inserting IDD 100 into an area of a human anatomy, including for example, subcutaneously. With IDD 100 inserted into the desired anatomical area, portions of solubilizer 210 (with dissolved API 200 ) that are small enough to pass through channeled member 130 can be released over time into the area of the human anatomy or for systemic circulation. In certain embodiments, the solubility enhancement of API 200 and solubilizer 210 can range from approximately 2×, 3×, 4×, 5×, 6×, 7×, 8×, 9×, 10×, 11×, 12×, 13×, 14×, 15×, 16×, 17×, 18×, 19×, 20×, 21×, 22×, 23×, 24×, 25×, 26×, 27×, 28×, 29×, 30× or higher. In particular embodiments, the solubility enhancement can be up to 1000× and higher. For example, with testosterone the native water solubility is 35 μg/ml, but in ethanol it is approximately 750 mg/ml, which is a 20,000× increase.
[0053] In certain embodiments, IDD 100 and channeled member 130 can be configured to release up to approximately 3, 4, 5, 6, 7, 8, 9 or 10 mg of API 200 per day over a period of time up 12 months. In other embodiments, IDD 100 may be configured to release a different dosage over shorter or longer periods of time. For example, in particular embodiments IDD 100 can be configured to release 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8 or 2.9 mg/day of API 200 . IDD 100 can also be configured to release API 200 over a matter of 1, 3, 4, 5, 6, or 7 days, 1, 2, 3, or 4 weeks, or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 months. In certain exemplary embodiments, IDD 100 can be configured to release between approximately 1 gm and 2 gm of API 200 over a period of approximately 12 months. In particular embodiments, IDD 100 and channeled member 130 can be configured to release between approximately 200-700 μg/day/cm 2 (as measured at the surface area of the channeled member exposed to reservoir 110 ).
[0054] In particular embodiments, therapeutic agent may comprise one or more of the following substances: testosterone, testosterone esters (including but not limited to testosterone enanthate, testosterone cypionate, testosterone propionate, and methyltestosterone). Many other therapeutic agents and other substances known to have low solubility in water may be used in the manner of this disclosure.
[0055] FIGS. 6 and 7 show an SEM cross-section image of a portion of a channeled member, including microchannels in fluid communication with nanochannels of height 200 nm and 50 nm, respectively.
[0056] FIG. 8 is a graph of a cumulative release rate of testosterone enanthate (TE) from a channeled member in combination with sesame oil and Labrasol in an 8:1:1 ratio of TE/sesame oil/Labrosol. FIG. 9 is a graph of a cumulative release rate of TE and sesame oil in a 9:1 ratio, while FIG. 10 is a graph of TE and Vitamin E TPGS in a 9:1 ratio. FIG. 11 is a graph of a cumulative release rate of TE/sesame oil/benzyl alcohol in an 8:1:1 ratio. FIG. 12 is a graph of a cumulative release rate of only TE from a channeled member. During testing, capsules containing 200 μl of formulation were placed in a 250 ml sink volume held at 37 degrees C. The sink condition was maintained with 3% added Labrosol, and the sink solution was replaced at each sampling time to maintain sink conditions. A constant release with average rates of approximately 1.1 mg-2.4 mg per day observed in all samples.
[0057] FIGS. 13-21 are graphs of a cumulative release rate of testosterone enanthate (TE) from a channeled member of with nanochannel heights of 160 nm, 190 nm, 200 nm, 210 nm, 220 nm, and 250 nm, and with and without a hydrophilic surface treatment included. During testing, capsules containing 200 μl of formulation were again placed in a 250 ml sink volume held at 37 degrees C. The sink condition was maintained with 3% added Labrosol, and the sink solution was replaced at each sampling time to maintain sink conditions. It is a surprising result of this disclosure that immiscible formulations within the reservoir have a diffusion rate that has low sensitivity to both nanochannel height and to hydrophobic/hydrophilic surface. This novel result of combining a channeled member with a solubilizer significantly adds to the utility and range of application of this disclosure.
[0058] FIG. 22 is a graph of serum concentration of testosterone in vivo. Three formulations were used: TE, TE:Sesame Oil:Labrosol and TE:Vitamin E TPGS. As shown in the legend, the test subjects included intact rats (Intact), castrated rats treated with a solid testosterone pellet implant (Pellet), castrated rats treated with a saline-filled implant (PBS), castrated rats treated with TE-only implants (TE), castrated rats with TE:sesame oil:labrosol (8:1:1) (TESOLA), and castrated rats with TE:Vitamin E TPGS (9:1) (TEVE). The formulations according to this disclosure are observed to provide significant testosterone serum levels while avoiding the typical “burst effect” observed in other implants and injections.
[0059] In particular embodiments, the therapeutic agent may comprise one or more of the following substances: adrenergic agent; adrenocortical steroid; adrenocortical suppressant; aldosterone; alkylating agent; antagonist; amino acid; anabolic; analeptic; analgesic; analgesic agonists and antagonists; anesthetic; anorexogenic; anti-acne agent; anti-adrenergic; anti-allergic; anti-alopecia agent; anti-amebic; anti-anemic; anti-anginal; antiangiogenic, anti-anxiety; anti-arthritic; anti-asthmatic; anti-atherosclerotic; antibacterial; antibiotic; anticancer; anticholinergic; anticoagulant; anticonvulsant; antidepressant; antidiabetic; antidiarrheal; antidiuretic; anti-dyskinetic; anti-emetic; anti-epileptic; antifibrinolytic; antifungal; anti-hemorrhagic; antihistamine; anti-hypercalcemic, anti-hypercholesterolaemic; anti-hyperlipidaemic; anti-hypertensive; anti-hypertriglyceridemic; anti-hypotensive; anti-infective; anti-inflammatory; anti-ischemic; antimicrobial; antimigraine; antimitotic; antimycotic; anti-nauseant; anti-neoplastic; anti-neutropenic; anti-obesity agent; anti-osteoporotic, antiparasitic; antiproliferative; antipsychotic; antiretroviral; anti-resorptives; anti-rheumatic; anti-seborrheic; antisecretory; antispasmodic; antisclerotic; antithrombotic; antitumor; anti-ulcerative; antiviral; appetite suppressant; bisphosphonate; blood glucose regulator; bronchodilator; cardiovascular agent; central nervous system agent; contraceptive; cholinergic; concentration aid; depressant; diagnostic aid; diuretic; DNA-containing agent, dopaminergic agent; estrogen receptor agonist; fertility agent; fibrinolytic; fluorescent agent; free oxygen radical scavenger; gastric acid suppressant; gastrointestinal motility effector; glucocorticoid; glutamatergic agent; hair growth stimulant; hemostatic; histamine H2 receptor antagonist; hormone; hypo cholesterolemic; hypoglycemic; hypolipidemic; hypotensive; imaging agent; immunizing agent; immunomodulator; immunostimulant; immunosuppressant; interleukin, keratolytic; LHRH agonist; mood regulator; mucolytic; mydriatic; nasal decongestant; neuromuscular blocking agent; neuroprotective; NMDA antagonist; non-hormonal sterol derivative; nootropic agent; opioids; parasympathomimetic agent; plasminogen activator; platelet activating factor antagonist; platelet aggregation inhibitor; platinum-containing agent, psychotropic; radioactive agent; raf antagonist, RNA-containing agent, scabicide; sclerosing agent; sedative; sedative-hypnotic; selective adenosine A1 antagonist; selective estrogen receptor modulator, serotonin antagonist; serotonin inhibitor; serotonin receptor antagonist; steroid; stimulant; thrombic agent; thyroid hormone; thyroid inhibitor; thyromimetic; tranquilizer; vasoconstrictor; vasodilator; wound healing agent; xanthine oxidase inhibitor; and the like; Abacavir, Abacavir sulfate, abatacept, Acarbose, Acetaminophen, Aciclovir, Adalimumab, Adapalene, Alendronate, Alendronate sodium, Alfuzosin, aliskiren, allopurinol, alvimopan, ambrisentan, Aminocaproic acid, Amitriptyline hydrochloride, amlodipine, amlodipine besylate, amoxicillin, amoxicilline, Amphetamine, Anastrozole, Aripiprazole, armodafinil, Atazanavir, atenolol, Atomoxetine, atorvastatin calcium, atorvastatin, Atropine sulfate, Azelastine, azithromycin, Balsalazide, Benazepril, bendamustine hydrochloride, Benzepril hydrochloride, bevacizumab, Bicalutamide, Bimatoprost, Bisoprolol, Bisoprolol fumarate, Bosentan, Botulin toxin, Budesonide, Buformin, Buprenorphine, Bupropion, bupropion hydrobromide, Bupropion Hydrochloride, Cabergoline, Calcipotriol, calcitriol, candesartan cilexetil, Capecitabine, Captopril, carbidopa, carisoprodol, Carvedilol, Caspofungin, Cefdinir, Cefoperazone, Cefotiam, cefprozil, Cefuroxime, Celecoxib, cephalaxin, Certolizumab Pegol, Cetirizine, Cetrizine hydrochloride, Cetuximab, Chlorpromazine hydrochloride, Chlorpheniramine maleate, ciclesonide, Cilastatin, cimetidine, Cinacalcet, Ciprofloxacin, citalopram hydrobromide, Clarithromycin, Clindamycin, Clindamycin, clindamycin hydrochloride, Clomipramine hydrochloride, Clonidine hydrochloride, clopidogrel, Clopidogrel bisulfate, Cloxacillin Sodium, Co-Amoxiclav, Codeine phosphate, Colchicines, Colesevelam, cyclobenzaprine hydrochloride, Cyclophosphamide, Cyclosporine, darbepoetin alfa, Darifenacin, DCRM 197 protein, Desloratadine, desloratidine, Desmopressin sulfate, Desoximetasone, dexamethasone, Diclofenac, Diethylcarbamazine citrate, difluprednate, diphenhydramine, Dipyridamole, DL-methionine, Docetaxel, Donepezil, doripenem, Dorzolamide, Doxazosin, doxazosin mesylate, doxycydine, Drospirenone, Duloxetine, Dutasteride, eculizumab, Efavirenz, Emtricitabine, Enalapril, enalapril maleate, Enoxaparin Sodium, Eprosartan, Erlotinib, Erythromycin, Erythropoetin, Escitalopram, esomeprazole, estradiol, Estrogen, Eszopiclone, etanercept, Ethembutol hydrochloride, Ethosuximide, ethynl estradiol, etonogestrel, etoricoxib, etravirine, Exenatide, Ezetimibe, Ezetimibe, Factor VII, famotidine, Famotidine, Fenofibrate, Fenofibrate, Fentanyl, Fentanyl citrate, Ferrous sulfate, Fexofenadine, fexofenadine hydrochloride, Filgrastim, Finasteride, fluconazole, Fluoxetine hydrochloride, Fluticasone, Fluvastatin, folic acid, Follitropin alfa, Follitropin beta, Formoterol, Fosinopril sodium, Gabapentin, Gabapentin, Gemcitabine, glargine insulin, Glatiramer, glimepride, Goserelin, histrelin acetate, Human growth hormone, Hydralazine hydrochloride, Hydrocodone bitartrate, Hydroxyurea, Hydroxyzine hydrochloride, Ibandronate, Imatinib, Imiglucerase, Imipenem, imiquimod, Indinavir sulfate, infliximab, Interferon beta-1a, Ipratropium, Irbesartan, Irinotecan, Isoniazid, Isosorbide moninitrate, ixabepilone, ketamine, ketoconazole, Ketorolac, Lactobionate, Lamivudine, Lamivudine, Lamotrigine, lanreotide acetate, Lansoprazole, lapatinib, laropiprant, Latanoprost, Letrozole, Leuprolide, Levalbuterol, Levamisole hydrochloride, Levetiracetam, levocetirizine dihydrochloride, levodopa, Levofloxacin, levonorgestrel, Levothyroxine, levothyroxine sodium, Lidocaine, Linezolid, Lisdexamfetamine Dimesylate, Lisinopril, Lispro insulin, Lopinavir, Loratadine, lorazepam, Losartan potassium, maraviroc, Marinol, meclizine hydrochloride, Meloxicam, Memantine, Meropenem, metaxalone, metformin, Metformin Hydrochloride, methadone, methoxy polyethylene glycol-epoetin beta, Methylphenidate, Methylphenidate hydrochloride, Metoprolol, Metoprolol tartrate, metronidazole, Metronidazole, miglitol, Minocycline, Minocycline hydrochloride, mirtazepine, Modafinil, Mometasone, montelukast, Montelukast sodium, Morphine, Moxifloxacin, Mycophenolate mofetil, Naloxone, Naproxen sodium, natalizumab, Neostigmine bromide, Niacin, Nicotinamide, Nifedipine, Nifurtimox, nilotinib hydrochloride monohydrate, nitrofurantoin, Nortriptyline hydrochloride, nystatin, olanzapine, Olanzepine, Olmesartan, olmesartan medoxomil, olopatadine hydrochloride, Omalizumab, Omega-3 acid ethyl esters, Omeprazole, Ondansetron, Opioids, Opoid Antagonists, Orlistat, Oseltamivir, Oxaliplatin, Oxcarbazepine, Oxybytynin chloride, oxycodone hydrochloride, Paclitaxel, Palivizumab, Pantoprazole, paracetamol, Paroxetine, paroxetine hydrochloride, Pegylated interferon alfa-2a, Pemetrexed, Penicillamine, Penicillin V potassium, Phenformin, Phenyloin sodium, Pioglitazone, Piperacillin, Potassium chloride, Pramipexole, Pravastatin, Pravastatin sodium, prednisolone quetiapine fumerate, Pregabalin, Primaquine phosphate, Progesterone, Promethazine, Promethazine hydrochloride, Proponolol hydrochloride, Propoxyphene hydrochloride, pseudoephedrine, Pseudophedrine hydrochloride, Pyridostigmine bromide, Pyridoxine hydrochloride, Quetiapine, quetiapine fumarate, Quinapril hydrochloride, Rabeprazole, raloxifene, raltegravir, Ramipril, Ranitidine, Ranitidine hydrochloride, Recombinant factor VIII, retapamulin, Rimonabant, Risedronate, Risedronate sodium, risperidone, Ritonavir, rituximab, Rivastigmine, rivastigmine tartrate, Rizatriptan, Ropinirole, rosiglitazone, Rosiglitazone maleate, Rosuvastatin, Rotavirus vaccine, rotigotine, Salbutamol, Salbutamol sulfate, salmeterol, sapropterin dihydrochloride, Sertraline, sertraline hydrochloride, Sevelamer, Sevoflurane, Sildenafil, sildenafil citrate, simvastatin, Simvastatin, Sitagliptin, Sodium valproate, Solifenacin, Somatostatin, Somatropin, Stavudine, Sulfomethoxazole, Sumatriptan, Sumatriptan succinate, Tacrolimus, Tadalafil, tamoxifen citrate, Tamsulosin, tamsulosin hydrochloride, Tegaserod, Telmisartan, temazepam, Temozolomide, temsirolimus, Tenofovir, Terazosin Hydrochloride, Terbinafine, Teriparatide, testosterone, Tetracycline hydrochloride, Thalidomide, thymopentin, Timolol meleate, Tiotropium, tipranavir, Tolterodine, tolterodine tartrate, topiramate, topotecan, Tramadol, Tramodol hydrochloride, trastuzumab, trazodone hydrochloride, trimethoprim, Valaciclovir, Valacyclovir hydrochloride, Valproate semisodium, valsartan, Vancomycin, Vardenafil, Varenicline, venlafaxine, Venlafaxine hydrochloride, Verapamil Hydrochloride, vildagliptin, Voglibose, Voriconazole, Wafarin sodium acetylsalicylic acid, Zaleplon, Zidovudine, Ziprasidone, Zoledronate, Zolpidem, or pharmaceutically acceptable salts thereof; 16-alpha fluoroestradiol, 17-alpha dihydroequilenin, 17-alpha estradiol, 17-beta estradiol, 17-hydroxyprogesterone, 1-dodecpyrrolidinone, 22-oxacalcitriol, 3-isobutyl-gammabutyric acid, 6-fluoroursodeoxycholic acid, 7-methoxytacrine, Abacavir, Abacavir sulfate, Abamectin, abanoquil, abatacept, abecarnil, abiraterone, Ablukast, Ablukast Sodium, Acadesine, acamprosate, Acarbose, Acebutolol, Acecamide Hydrochloride, Aceclidine, aceclofenae, Acedapsone, Acedapsone, Aceglutamide Aluminum, Acemannan, Acetaminophen, Acetazolamide, Acetohexamide, Acetohydroxamic Acid, acetomepregenol, Acetophenazine Maleate, Acetosulfone Sodium, Acetylcholine Chloride, Acetylcysteine, acetyl-L-carnitine, acetylmethadol, Aciclovir, Acifran, acipimox, acitemate, Acitretin, Acivicin, Aclarubicin, aclatonium, Acodazole Hydrochloride, aconiazide, Acrisorcin, Acrivastine, Acronine, Actisomide, Actodigin, Acyclovir, acylfulvene, Adatanserin Hydrochloride, adafenoxate, Adalimumab, Adapalene, adatanserin, adecypenol, adecypenol, Adefovir, adelmidrol, ademetionine, Adenosine, Adinazolam, Adipheinine Hydrochloride, adiposin, Adozelesin, adrafinil, Adrenalone, Aiclometasone Dipropionate, airbutamine, alacepril, Alamecin, Alanine, Alaproclate, alaptide, Albendazole, albolabrin, Albuterol, Alclofenae, Alcloxa, aldecalmycin, Aldesleukin, Aldioxa, Aletamine Hydrochloride, Alendronate, Alendronate Sodium, alendronic acid, alentemol, Alentemol Hydrobromide, Aleuronium Chloride, Alexidine, alfacalcidol, Alfentanil Hydrochloride, alfuzosin, Algestone Acetonide, alglucerase, Aliflurane, alinastine, Alipamide, aliskiren, Allantoin, Allobarbital, Allopurinol, Alonimid, alosetron, Alosetron Hydrochloride, Alovudine, Alpertine, alpha-idosone, Alpidem, Alprazolam, Alprenolol Hydrochloride, Alprenoxime Hydrochloride, Alprostadil, Alrestatin Sodium, Altanserin Tartrate, Alteplase, Althiazide, Altretamine, altromycin B, Alverinc Citrate, alvimopan, Alvircept Sudotox, Amadinone Acetate, Amantadine Hydrochloride, ambamustine, Ambomycin, ambrisentan, Ambruticin, Ambuphylline, Ambuside, Amcinafal, Amcinonide, Amdinocillin, Amdinocillin Pivoxil, Amedalin Hydrochloride, amelometasone, Ameltolide, Amesergide, Ametantrone Acetate, amezinium metilsulfate, amfebutamone, Amfenac Sodium, Amfiutizole, Amicycline, Amidephrine Mesylate, amidox, Amifloxacin, amifostine, Amilcacin, Amiloride Hydrochloride, Aminacrine Hydrochloride, Aminobenzoate Potassium, Aminobenzoate Sodium, Aminocaproic Acid, Aminoglutethimide, Aminohippurate Sodium, aminolevulinic acid, Aminophylline, A minorex, Aminosalicylate sodium, Aminosalicylic acid, Amiodarone, Amiprilose Hydrochloride, Amiquinsin Hydrochloride, amisulpride, Amitraz, Amitriptyline Hydrochloride, Amlexanox, amlodipine, amlodipine besylate, Amobarbital Sodium, Amodiaquine, Amodiaquine Hydrochloride, Amorolfine, Amoxapine, Amoxicillin, Amphecloral, Amphetamine, Amphetamine Sulfate, Amphomycin, Amphoterin B, Ampicillin, ampiroxieam, Ampyzine Sulfate, Amquinate, Amrinone, amrubicin, Amsacrine, Amylase, amylin, amythiamicin, Anagestone Acetate, anagrelide, Anakinra, ananain, anaritide, Anaritide Acetate, Anastrozole, Anazolene Sodium, Ancrod, andrographolide, Androstenedione, Angiotensin Amide, Anidoxime, Anileridine, Anilopam Hydrochloride, Aniracetam, Anirolac, Anisotropine Methylbromide, Anistreplase, Anitrazafen, anordrin, antagonist D, antagonist G, antarelix, Antazoline Phosphate, Anthelmycin, Anthralin, Anthramyciantiandrogen, antiestrogen, antineoplaston, Antipyrine, antisense oligonucleotides, apadoline, apafant, Apalcillin Sodium, apaxifylline, Apazone, aphidicolin glycinate, Apixifylline, Apomorphine Hydrochloride, apraclonidine, Apraclonidine Hydrochloride, Apramycin, Aprindine, Aprindine Hydrochloride, aprosulate sodium, Aprotinin, Aptazapine Maleate, aptiganel, apurinic acid, apurinic acid, aranidipine, Aranotin, Arbaprostil, arbekicin, arbidol, Arbutamine Hydrochloride, Arclofenin, Ardeparin Sodium, argatroban, Arginine, Argipressin Tannate, Arildone, Aripiprazole, armodafinil, arotinolol, Arpinocid, Arteflene, Artilide Fumarate, asimadoline, aspalatone, Asparaginase, Aspartic Acid, Aspartocin, asperfuran, Aspirin, aspoxicillin, Asprelin, Astemizole, Astromicin Sulfate, asulacrine, atamestane, Atazanavir, Atenolol, atevirdine, Atipamezole, Atiprosin Maleate, Atolide, Atomoxetine, atorvastatin, Atorvastatin Calcium, Atosiban, Atovaquone, atpenin B, Atracurium Besylate, atrimustine, atrinositol, Atropine, Atropine sulfate, Auranofin, aureobasidin A, Aurothioglucose, Avilamycin, Avoparcin, Avridine, Axid, axinastatin 1, axinastatin 2, axinastatin 3, Azabon, Azacitidinie, Azaclorzine Hydrochloride, Azaconazole, azadirachtine, Azalanstat Dihydrochloride, Azaloxan Fumarate, Azanator Maleate, Azanidazole, Azaperone, Azaribine, Azaserine, azasetron, Azatadine Maleate, Azathioprine, Azathioprine Sodium, azatoxin, azatyrosine, azelaic acid, Azelastine, azelnidipine, Azepindole, Azetepa, azimilide, Azithromycin, Azlocillin, Azolimine, Azosemide, Azotomycin, Aztreonam, Azumolene Sodium, Bacampicillin Hydrochloride, baccatin III, Bacitracin, Baclofen, bacoside A, bacoside B, bactobolamine, balanol, balazipone, balhimycin, balofloxacin, balsalazide, Bambermycins, bambuterol, Bamethan Sulfate, Bamifylline Hydrochloride, Bamidazole, baohuoside 1, Barmastine, barnidipine, Basic, Basifungin, Batanopride Hydrochloride, batebulast, Batelapine Maleate, Batimastat, beau vericin, Becanthone Hydrochloride, becaplermin, becliconazole, Beclomethasone Dipropionate, befloxatone, Beinserazide, Belfosdil, Belladonna, Beloxamide, Bemesetron, Bemitradine, Bemoradan, Benapryzine Hydrochloride, Benazepril, Benazepril Hydrochloride, Benazeprilat, Benda calol Mesylate, bendamustine hydrochloride, Bendazac, Bendroflumethiazide, benflumetol, benidipine, Benorterone, Benoxaprofen, Benoxaprofen, Benoxinate Hydrochloride, Benperidol, Bentazepam, Bentiromide, Benurestat, Benzbromarone, Benzepril hydrochloride, Benzethonium Chloride, Benzetimide Hydrochloride, Benzilonium Bromide, Benzindopyrine Hydrochloride, benzisoxazole, Benzocaine, benzochlorins, Benzoctamine Hydrochloride, Benzodepa, benzoidazoxan, Benzonatate, Benzoyl Peroxide, benzoylstaurosporine, Benzquinamide, Benzthiazide, benztropine, Benztropine Mesylate, Benzydamine Hydrochloride, Benzylpenicilloyl Polylysine, bepridil, Bepridil Hydrochloride, Beractant, Beraprost, Berefrine, berlafenone, bertosamil, Berythromycin, besipirdine, betaalethine, betaclamycin B, Betamethasone, betamipron, betaxolol, Betaxolol Hydrochloride, Bethanechol Chloride, Bethanidine Sulfate, betulinic acid, bevacizumab, bevantolol, Bevantolol Hydrochloride, Bezafibrate, Bialamicol Hydrochloride, Biapenem, Bicalutamide, Bicifadine Hydrochloride, Biclodil Hydrochloride, Bidisomide, bifemelane, Bifonazole, bimakalim, Bimatoprost, bimithil, Bindarit, Biniramycin, binospirone, bioxalomycin, Bipenamol Hydrochloride, Biperiden, Biphenamine Hydrochloride, biriperone, bisantrene, bisaramil, bisaziridinylspermine, bis-benzimidzole A, bis-benzimidazole B, bisnafide, Bisobrin Lactate, Bisoprolol, Bisoprolol fumarate, Bispyrithione Magsulfex, bistramide D, bistramide K, bistratene A, Bithionolate Sodium, Bitolterol Mesylate, Bivalirudin, Bizelesin, Bleomycin Sulfate, boldine, Bolandiol Dipropionate, Bolasterone, Boldenone Undecylenate, Bolenol, Bolmantalate, bopindolol, Bosentan, Botulin toxin, Boxidine, brefeldin, breflate, Brequinar Sodium, Bretazenil, Bretylium Tosylate, Brifentanil Hydrochloride, brimonidine, Brinolase, Brocresine, Brocrinat, Brofoxine, Bromadoline Maleate, Bromazepam, Bromchlorenone, Bromelain, bromfenac, Brominidione, Bromocriptine, Bromodiphenhydramine Hydrochloride, Bromoxanide, Bromperidol, Bromperidol Decanoate, Brompheniramine Maleate, Broperamole, Bropirimine, Brotizolam, Bucamide Maleate, bucindolol, Buclizine Hydrochloride, Bucromar one, Budesonide, budipine, budotitane, Buformin, Bumetanide, Bunaprolast, bunazosin, Bunolol Hydrochloride, Bupicomide, Bupivacaine Hydrochloride, Buprenorphine, Buprenorphine Hydrochloride, Bupropion, bupropion hydrobromide, Bupropion Hydrochloride, Buramate, Buserelin Acetate, Buspirone Hydrochloride, Busulfan, Butabarbital, Butacetin, Butaclamol Hydrochloride, Butalbital, Butamben, Butamirate Citrate, Butaperazine, Butaprost, Butedronate Tetrasodium, butenafine, Buterizine, buthioninc sulfoximine, Butikacin, Butilfenin, Butirosin Sulfate, Butixirate, butixocort propionate, Butoconazole Nitrate, Butonate, Butopamine, Butoprozine Hydrochloride, Butorphanol, Butoxamine Hydrochloride, Butriptyline Hydrochloride, Cabergoline, Cactinomycin, Cadexomer Iodine, Caffeine, calanolide A, Calcifediol, Calcipotriene, calcipotriol, Calcitonin, Calcitriol, Calcium Undecylenate, calphostin C, Calusterone, Cambendazole, Cammonam Sodium, camonagrel, canary pox IL-2, candesartan, candesartan cilexetil, Candicidin, candoxatril, candoxatrilat, Caniglibose, Canrenoate Potassium, Canrenone, capecitabine, Capobenate Sodium, Capobenic Acid, Capreomycin Sulfate, capromab, capsaicin, Captopril, Capuride, Car bocysteine, Caracemide, Carbachol, Carbadox, Carbamazepine, Carbamide Peroxide, Carbantel Lauryl Sulfate, Carbaspirin Calcium, Carbazeran, carbazomycin C, Carbenicillin Potassium, Carbenoxolone Sodium, Carbetimer, carbetocin, Carbidopa, Carbidopa-Levodopa, Carbinoxamine Maleate, Carbiphene Hydrochloride, Carbocloral, Carbol-Fuchsin, Carboplatin, Carboprost, carbovir, carboxamide-amino-triazo-1e, carboxyamidotriazole, carboxymethylated beta-1,3-glucan, Carbuterol Hydrochloride, CaRest M3, Carfentanil Citrate, Carisoprodol, Carmantadine, Carmustine, CARN 700, Carnidazole, Caroxazone, carperitide, Carphenazine Maleate, Carprofen, Carsatrin Succinate, Cartazolate, carteolol, Carteolol Hydrochloride, Carubicin Hydrochloride, carvedilol, carvotroline, Carvotroline Hydrochloride, carzelesin, Caspofungin, castanospermine, caurumonam, cebaracetam, cecropin B, Cedefingol, Cefaclor, Cefadroxil, Cefamandole, Cefaparole, Cefatrizine, Cefazaflur Sodium, Cefazolin, cefcapene pivoxil, cefdaloxime pentexil tosilate, Cefdinir, cefditoren pivoxil, Cefepime, cefetamet, Cefetecol, cefixime, cefluprenam, Cefinenoxime Hydrochloride, Cefinetazole, cefminlox, cefodizime, Cefonicid Sodium, Cefoperazone, Cefoperazone Sodium, Ceforanide, cefoselis, Cefotaxime Sodium, Cefotetan, cefotiam, Cefoxitin, cefozopran, cefpimizole, Cefpiramide, cefpirome, cefpodoxime proxetil, cefprozil, Cefroxadine, cefsulodin, Ceftazidime, cefteram, ceftibuten, Ceftizoxime Sodium, ceftriaxooe, Cefuroxime, celastrol, Celecoxib, celikalim, celiprolol, cepacidiine A, Cephacetrile Sodium, Cephalexin, Cephaloglycin, Cephaloridine, Cephalothin Sodium, Cephapirin Sodium, Cephradine, cericlamine, cerivastatin, Ceruletide, Ceronapril, Certolizumab Pegol, certoparin sodium, Cetaben Sodium, Cetalkonium Chloride, Cetamolol Hydrochloride, Cethuperazone, cetiedil, cetirizine, Cetophenicol, Cetraxate Hydrochloride, Cetrizine hydrochloride, cetrorelix, Cetuximab, Cetylpyridinium Chloride, Chenodiol, Chlophedianol Hydrochloride, Chloral Betaine, Chlorambucil, Chloramphenicol, Chlordantoin, Chlordiazepoxide, Chlorhexidine Gluconate, chlorins, Chlormadinone Acetate, chloroorienticin A, Chloroprocaine Hydrochloride, Chloropropamide, Chloroquine, chloroquinoxaline sulfonamide, Chlorothiazide, Chlorotrianisene, Chloroxine, Chloroxylenol, Chlorpheniramine Maleate, Chlorphenesin Carbamate, Chlorpheniramine maleate, Chlorpromazine, Chlorpromazine hydrochloride, Chlorpropamide, Chlorprothixene, Chlortetracycline Bisulfate, Chlorthalidone, Chlorzoxazone, Cholestyramine Resin, Chromonar Hydrochloride, cibenzoline, cicaprost, Ciclafrine Hydrochloride, Ciclazindol, ciclesonide, cicletanine, Ciclopirox, Cicloprofen, cicloprolol, Cidofovir, Cidoxepin Hydrochloride, Cifenline, Ciglitazone, Ciladopa Hydrochloride, cilansetron, Cilastatin, Cilastatin Sodium, Cilazapril, cilnidipine, Cilobamine Mesylate, cilobradine, Cilofungin, cilostazol, Cimaterol, Cimetidine, cimetropium bromide, Cinacalcet, Cinalukast, Cinanserin Hydrochloride, Cinepazet Maleate, Cinflumide, Cingestol, cinitapride, Cinnamedrine, Cinnarizine, cinolazepam, Cinoxacin, Cinperene, Cinromide, Cintazone, Cintriamide, Cioteronel, Cipamfylline, Ciprefadol Succinate, Ciprocinonide, Ciprofibrate, Ciprofloxacin, ciprostene, Ciramadol, Cirolemycin, Cisplatin, cisapride, cisatracurium besilate, Cisconazole, cis-porphyrin, cistinexine, citalopram, citalopram hydrobromide, Citenamide, citicoline, citreamicin alpha, cladribine, Clamoxyquin Hydrochloride, Clarithromycin, clausenamide, Clavulanate Potassium, Clazolam, Clazolimine, clebopride, Clemastine, Clentiazem Maleate, Clidinium Bromide, clinafloxacin, Clindamycin, clindamycin hydrochloride, Clioquinol, Clioxanide, Cliprofen, clobazam, Clobetasol Propionate, Clobetasone Butyrate, Clocortolone Acetate, Clodanolene, Clodazon Hydrochloride, clodronic acid, Clofazimine, Clofibrate, Clofilium Phosphate, Cloge stone Acetate, Clomacran Phosphate, Clomegestone Acetate, Clometherone, clomethiazole, clomifeneanalogues, Clominorex, Clomiphene, Clomipramine Hydrochloride, Clonazepam, Clonidine, Clonidine hydrochloride, Clonitrate, Clonixeril, Clonixin, Clopamide, Clopenthixol, Cloperidone Hydrochloride, clopidogrel, Clopidogrel bisulfate, Clopimozide, Clopipazan Mesylate, Clopirac, Cloprednol, Cloprostenol Sodium, Clorazepate Dipotassium, Clorethate, Clorexolone, Cloroperone Hydrochloride, Clorprenaline Hydrochloride, Clorsulon, Clortemine Hydrochloride, Closantel, Closiramine Aceturate, Clothiapine, Clothixamide Maleate Cloticasone Propionate, Clotrimazole, Cloxacillin Benzathine, Cloxacillin Sodium, Cloxyquin, Clozapine, Co-Amoxiclav, Cocaine, Coccidioidin, Codeine, Codeine phosphate, Codoxime, Colchicine, Colesevelam, colestimide, Colestipol Hydrochloride, Colestolone, Colforsin, Colfosceril Palmitate, Colistimethate Sodium, Colistin Sulfate, collismycin A, collismycin B, Colterol Mesylate, combretastatin A4, complestatin, conagenin, Conorphone Hydrochloride, contignasterol, contortrostatin, Cormethasone Acetate, Corticorelin Ovine Tnflutate, Corticotropin, Cortisone Acetate, Cortivazol, Cortodoxone, cosalane, costatolide, Cosyntropin, cotinine, Coumadin, Coumermycin, crambescidin, Crilvastatin, crisnatol, Cromitrile Sodium, Cromolyn Sodium, Crotamiton, cryptophycin, cucumariosid, Cuprimyxin, curacin A, curdlan sulfate, curiosin, Cyclacillin, Cyclazocine, cyclazosin, Cyclindole, Cycliramine Maleate, Cyclizine, Cyclobendazole, cyclobenzaprine, cyclobenzaprine hydrochloride, cyclobut A, cyclobut G, cyclocapron, Cycloguanil Pamoate, Cycloheximide, cyclopentanthraquinones, Cyclopenthiazide, Cyclopentolate Hydrochloride, Cyclophenazine Hydrochloride, Cyclophosphamide, cycloplatam, Cyclopropane, Cycloserine, cyclosin, Cyclosporine, cyclothialidine, Cyclothiazide, cyclothiazomycin, Cyheptamide, cypemycin, Cyponamine Hydrochloride, Cyprazepam, Cyproheptadine Hydrochloride, Cyprolidol Hydrochloride, cyproterone, Cyproximide, Cysteamine, Cysteine Hydrochloride, Cystine, Cytarabine, Cytarabine Hydrochloride, cytarabine ocfosfate, cytochalasin B, cytostatin, Dacarbazine, dacliximab, dactimicin, Dactinomycin, daidzein, Daledalin Tosylate, dalfopristin, Dalteparin Sodium, Daltroban, Dalvastatin, danaparoid, Danazol, Dantrolene, daphlnodorin A, dapiprazole, dapitant, Dapoxetine Hydrochloride, Dapsone, Daptomycin, darbepoetin alfa, Darglitazone Sodium, darifenacin, darlucin A, Darodipine, darsidomine, Daunorubicin Hydrochloride, Dazadrol Maleate, Dazepinil Hydrochloride, Dazmegrel, Dazopride Fumarate, Dazoxiben Hydrochloride, DCRM 197 protein, Debrisoquin Sulfate, Decitabine, deferiprone, deflazacort, Dehydrocholic Acid, dehydrodidemnin B, Dehydroepiandrosterone, delapril, Delapril Hydrochloride, Delavirdine Mesylate, delequamine, delfaprazine, Delmadinone Acetate, delmopinol, delphinidin, Demecarium Bromide, Demeclocycline, Demecycline, Demoxepam, Denofungin, deoxypyridinoline, Depakote, deprodone, Deprostil, depsidomycin, deramciclane, dermatan sulfate, Desciclovir, Descinolone Acetonide, Desfurane, Desipramine Hydrochloride, desirudin, Deslanoside, Desloratadine, deslorelin, desmopressin, Desmopressin sulfate, desogestrel, Desonide, Desoximetasone, desoxoamiodarone, Desoxy-corticosterone Acetate, detajmium bitartrate, Deterenol Hydrochloride, Detirelix Acetate, Devazepide, Dexamethasone, Dexamisole, Dexbrompheniramine Maleate, Dexchlorpheniramine Maleate, Dexclamol Hydrochloride, Dexetimide, Dexfenfluramine Hydrochloride, dexifosfamide, Deximafen, dexketoprofen, dexloxiglumide, Dexmedetomidine, Dexormaplatin, Dexoxadrol Hydrochloride, Dexpanthenol, Dexpemedolac, Dexpropranolol Hydrochloride, Dexrazoxane, dexsotalol, dextrin 2-sulphate, Dextroamphetamine, Dextromethorphan, Dextrorphan Hydrochloride, Dextrothyroxine Sodium, dexverapamil, Dezaguanine, dezinamide, dezocine, Diacetolol Hydrochloride, Diamocaine Cyclamate, Diapamide, Diatrizoate Meglumine, Diatrizoic Acid, Diaveridine, Diazepam, Diaziquone, Diazoxide, Dibenzepin Hydrochloride, Dibenzothiophene, Dibucaine, Dichliorvos, Dichloralphenazone, Dichlorphenamide, Dicirenone, Diclofenac, Diclofenac Sodium, Dicloxacillin, dicranin, Dicumarol, Dicyclomine Hydrochloride, Didanosine, didemnin B, didox, Dienestrol, dienogest, Diethylcarbamazine Citrate, diethylhomospermine, diethylnorspermine, Diethylpropion Hydrochloride, Diethylstilbestrol, Difenoximide Hydrochloride, Difenoxin, Diflorasone Diacetate, Difloxacin Hydrochloride, Difluanine Hydrochloride, Diflucortolone, Diflumidone Sodium, Diflunisal, Difluprednate, Diftalone, Digitalis, Digitoxin, Digoxin, Dihexyverine Hydrochloride, dihydrexidine, dihydro-5-azacytidine, Dihydrocodeine Bitartrate, Dihydroergotamine Mesylate, Dihydroestosterone, Dihydrostreptomycin Sulfate, Dihydrotachysterol, Dilantin, Dilevalol Hydrochloride, Diltiazem Hydrochloride, Dimefadane, Dimefline Hydrochloride, Dimenhydrinate, Dimercaprol, Dimethadione, Dimethindene Maleate, Dimethisterone, Dimethyl Sulfoxide, dimethylhomospermine, dimethylprostaglandin A1, dimiracetam, Dimoxamine Hydrochloride, Dinoprost, Dinoprostone, Dioxadrol Hydrochloride, dioxamycin, diphenhydramine, Diphenhydramine Citrate, Diphenidol, Diphenoxylate Hydrochloride, diphenylspiromustine, Dipivefin Hydrochloride, Dipivefrin, dipliencyprone, diprafenone, dipropylnorspermine, Dipyridamole, Dipyrithione, Dipyrone, dirithromycin, discodermolide, Disobutamide, Disofenin, Disopyramide, Disoxaril, disulfuram, Ditekiren, Divalproex Sodium, Dizocilpine Maleate, DL-methionine, Dobutamine, docarpamine, Docebenone, Docetaxel, Doconazole, docosanol, dofetilide, dolasetron, Donepezil, doripenem, Dorzolamide, Doxazosin, doxazosin mesylate, doxycydine, Drospirenone, Duloxetine, Dutasteride, Ebastine, ebiratide, ebrotidine, ebselen, ecabapide, ecabet, ecadotril, ecdisteron, echicetin, echistatin, Echothiophate Iodide, Eclanamine Maleate, Eclazolast, ecomustine, Econazole, ecteinascidin 722, eculizumab, edaravone, Edatrexate, edelfosine, Edifolone Acetate, edobacomab, Edoxudine, edrecolomab, Edrophonium Chloride, edroxyprogesteone Acetate, Efavirenz, efegatran, eflornithine, efonidipine, egualcen, Elantrine, eleatonin, elemene, eletriptan, elgodipine, eliprodil, Elsamitrucin, eltenae, Elucaine, emailcalim, emedastine, Emetine Hydrochloride, emiglitate, Emilium Tosylate, emitefur, emoctakin, Emtricitabine, Enadoline Hydrochloride, Enailciren, enalapril, enalapril maleate, enazadrem, Encyprate, Endralazine Mesylate, Endrysone, Enflurane, englitazone, Enilconazole, Enisoprost, Enlimomab, Enloplatin, Enofelast, Enolicam Sodium, Enoxacin, enoxacin, enoxaparin sodium, Enoxaparin Sodium, Enoximone, Enpiroline Phosphate, Enprofylline, Enpromate, entacapone, enterostatin, Enviradene, Enviroxime, Ephedrine, Epicillin, Epimestrol, Epinephrine, Epinephryl Borate, Epipropidine, Epirizole, epirubicin, Epitetracycline Hydrochloride, Epithiazide, Epoetin Alfa, Epoetin Beta, Epoprostenol, Epoprostenol Sodium, epoxymexrenone, epristeride, Eprosartan, eptastigmine, equilenin, Equilin, Erbulozole, erdosteine, Ergoloid Mesylates, Ergonovine Maleate, Ergotamine Tartrate, Erlotinib, ersentilide, Ersofermin, erythritol, Erythrityl Tetranitrate, Erythromycin, Erythropoetin, Escitalopram, Esmolol Hydrochloride, esomeprazole, Esorubicin Hydrochloride, Esproquin Hydrochloride, Estazolam, Estradiol, Estramustine, Estrazinol Hydrobromide, Estriol, Estrofurate, Estrogen, Estrone, Estropipate, esuprone, Eszopiclone, Etafedrine Hydrochloride, etanercept, Etanidazole, etanterol, Etarotene, Etazolate Hydrochloride, Eterobarb, ethacizin, Ethacrynate Sodium, Ethacrynic Acid, Ethambutol Hydrochloride, Ethamivan, Ethanolamine Oleate, Ethehlorvynol, Ethembutol hydrochloride, Ethinyl estradiol, Ethiodized Oil, Ethionamide, Ethonam Nitrate, Ethopropazine Hydrochloride, Ethosuximide, Ethosuximide, Ethotoin, Ethoxazene Hydrochloride, Ethybenztropine, Ethyl Chloride, Ethyl Dibunate, Ethylestrenol, Ethyndiol, Ethynerone, ethynl estradiol, Ethynodiol Diacetate, Etibendazole, Etidocaine, Etidronate Disodium, Etidronic Acid, Etifenin, Etintidine Hydrochloride, etizolam, Etodolac, Etofenamate, Etoformin Hydrochloride, Etomidate, Etonogestrel, Etoperidone Hydrochloride, Etoposide, Etoprine, etoricoxib, Etoxadrol Hydrochloride, Etozolin, etrabamine, etravirine, Etretinate, Etryptamine Acetate, Eucatropine Hydrochloride, Eugenol, Euprocin Hydrochloride, eveminomicin, Exametazime, examorelin, Exaprolol Hydrochloride, exemestane, Exenatide, Ezetimibe, Ezetimibe, Factor VII, fadrozole, faeriefungin, Famciclovir, Famotidine, Fampridine, fantofarone, Fantridone Hydrochloride, faropenem, fasidotril, fasudil, fazarabine, fedotozine, Felbamate, felbamate, Felbinac, Felodipine, Felypressin, Fenalamide, Fenamole, Fenbendazole, Fenbufen, Fencibutirol, Fenclofenac, Fenclonine, Fenclorac, Fendosal, Fenestrel, Fenethylline Hydrochloride, Fenfluramine Hydrochloride, Fengabine, Fenimide, Fenisorex, Fenmetozole Hydrochloride, Fenmetramide, Fenobam, Fenoctimine Sulfate, Fenofibrate, fenoldopam, Fenoprofen, Fenoterol, Fenpipalone, Fenprinast Hydrochloride, Fenprostalene, Fenquizone, fenretinide, fenspiride, fentanyl, Fentanyl Citrate, Fentiazac, Fenticlor, fenticonazole, Fenyripol Hydrochloride, fepradinol, ferpifosate sodium, ferristene, ferrixan, Ferrous Sulfate, Ferumoxides, ferumoxsil, Fetoxylate Hydrochloride, Fexofenadine, fexofenadine hydrochloride, Fezolamine Fumarate, Fiacitabine, Fialuridine, fibmoxef, Fibrinogen, Filgrastim, Filipin, Finasteride, fiorfenicol, fiorifenine, fiosatidil, fiumecinol, fiunarizine, fiuparoxan, fiupirtine, fiurithromycin, fiutrimazole, fiuvastatin, fiuvoxamine, Flavodilol Maleate, flavopiridol, Flavoxate Hydrochloride, Flazalone, flecamide, flerobuterol, Fleroxacin, flesinoxan, Flestolol Sulfate, Fletazepam, flezelastine, flobufen, Floctafenine, Flordipine, Flosequinan, Floxacillin, Floxuridine, fluasterone, Fluazacort, Flubanilate Hydrochloride, Flubendazole, Flucindole, Flucloronide, Fluconazole, Flucytosine, Fludalanine, Fludarabine Phosphate, Fludazonium Chloride, Fludeoxyglucose, Fludorex, Fludrocortisone Acetate, Flufenamic Acid, Flufenisal, Flumazenil, Flumequine, Flumeridone, Flumethasone, Flumetramide, Flumezapine, Fluminorex, Flumizole, Flumoxonide, Flunidazole, Flunisolide, Flunitrazepam, Flunixin, fluocalcitriol, Fluocinolone Acetonide, Fluocinonide, Fluocortin Butyl, Fluocortolone, Fluorescein, fluorodaunorunicin hydrochloride, Fluorodopa, Fluorometholone, Fluorouracil, Fluotracen Hydrochloride, Fluoxetine, Fluoxetine hydrochloride, Fluoxymesterone, Fluperamide, Fluperolone Acetate, Fluphenazine Decanoate, Fluprednisolone, Fluproquazone, Fluprostenol Sodium, Fluquazone, Fluradoline Hydrochloride, Flurandrenolide, Flurazepam Hydrochloride, Flurbiprofen, Fluretofen, Fluorocitabine, Fluorofamide, Fluorogestone Acetate, Fluorothyl, Fluoroxene, Fluspiperone, Fluspirilene, Fluticasone, Fluticasone Propionate, Flutroline, Fluvastatin, Fluvastatin Sodium, Fluzinamide, Folic Acid, Follicle regulatory protein, Folliculostatin, Follitropin alfa, Follitropin beta, Fomepizole, Fonazine Mesylate, forasartan, forfenimex, forfenirmex, formestane, Formocortal, formoterol, Fosarilate, Fosazepam, Foscarnet Sodium, fosfomycin, Fosfonet Sodium, fosinopril, Fosinopril sodium, Fosinoprilat, fosphenyloin, Fosquidone, Fostedil, fostriecin, fotemustine, Fuchsin, Fumoxicillin, Fungimycin, Furaprofen, Furazolidone, Furazolium Chloride, Furegrelate Sodium, Furobufen, Furodazole, Furosemide, Fusidate Sodium, Fusidic Acid, Gabapentin, Gadobenate Dimeglumine, gadobenic acid, gadobutrol, Gadodiamide, gadolinium texaphyrin, Gadopentetate Dimegiumine, gadoteric acid, Gadoteridol, Gadoversetamide, galantamine, galdansetron, Galdansetron Hydrochloride, Gallamine Triethiodide, gallium nitrate, gallopamil, galocitabine, Gamfexine, gamolenic acid, Ganciclovir, ganirelix, Gemcadiol, Gemcitabine, Gemeprost, Gemfibrozil, Gentamicin Sulfate, Gentian Violet, gepirone, Gestaclone, Gestodene, Gestonorone Caproate, Gestrinone, Gevotroline Hydrochloride, girisopam, glargine insulin, glaspimod, Glatiramer, glaucocalyxin A, Glemanserin, Gliamilide, Glibornuride, Glicetanile Sodium, Glifiumide, Glimepiride, Glipizide, Gloximonam, Glucagon, glutapyrone, Glutethimide, Glyburide, glycopine, glycopril, Glycopyrrolate, Glyhexamide, Glymidine Sodium, Glyoctamide, Glyparamide, Gold Au-198, Gonadoctrinins, Gonadorelin, Gonadotropins, Goserelin, Gramicidin, Granisetron, grepafloxacin, Griseofulvin, Guaiapate, Guaithylline, Guanabenz, Guanabenz Acetate, Guanadrel Sulfate, Guancydine, Guanethidine Monosulfate, Guanfacine Hydrochloride, Guanisoquin Sulfate, Guanoclor Sulfate, Guanoctine Hydrochloride, Guanoxabenz, Guanoxan Sulfate, Guanoxyfen Sulfate, Gusperimus Trihydrochloride, Halazepam, Halcinonide, halichondrin B, Halobetasol Propionate, halofantrine, Halofantrine Hydrochloride, Halofenate, Halofuginone Hydrobromide, halomon, Halopemide, Haloperidol, halopredone, Haloprogesterone, Haloprogin, Halothane, Halquinols, Hamycin, hatomamicin, hatomarubigin A, hatomarubigin B, hatomarubigin C, hatomarubigin D, Heparin Sodium, hepsulfam, heregulin, Hetacillin, Heterooium Bromide, Hexachlorophene Hydrogen Peroxide, Hexafluorenium Bromide, hexamethylene bisacetamide, Hexedine, Hexobendine, Hexoprenaline Sulfate, Hexylresorcinol, Histamine Phosphate, Histidine, Histoplasmin, Histrelin, histrelin acetate, Homatropine Hydrobromide, Hoquizil Hydrochloride, Human chorionic gonadotropin, Human growth hormone, Hycanthone, Hydralazine Hydrochloride, Hydralazine Polistirex, Hydrochlorothiazide, Hydrocodone Bitartrate, Hydrocortisone, Hydroflumethiazide, Hydromorphone Hydrochloride, Hydroxyamphetamine Hydrobromide, Hydroxychloroquine Sulfate, Hydroxyphenamate, Hydroxyprogesterone Caproate, Hydroxyurea, Hydroxyzine Hydrochloride, Hymecromone, Hyoscyamine, hypericin, Ibafloxacin, Ibandronate, ibogaine, Ibopam, ibudilast, Ibufenac, Ibuprofen, Ibutilide Fumarate, Icatibant Acetate, Ichthammol, Icotidine, idarubicin, idoxifene, Idoxuridine, idramantone, Ifetroban, Ifosfamide, Ilepeimide, illimaquinone, ilmofosin, ilomastat, Ilonidap, iloperidone, iloprost, Imafen Hydrochloride, Imatinib, Imazodan Hydrochloride, imidapril, imidazenil, imidazoacridone, Imidecyl Iodine, Imidocarb Hydrochloride, Imidoline Hydrochloride, Imidurea, Imiglucerase, Imiloxan Hydrochloride, Imipenem, Imipramine Hydrochloride, imiquimod, Impromidine Hydrochloride, Indacrinone, Indapamide, Indecamide Hydrochloride, Indeloxazine Hydrochloride, Indigotindisulfonate Sodium, indinavir, Indinavir sulfate, Indocyanine Green, Indolapril Hydrochloride, Indolidan, indometacin, Indomethacin Sodium, Indoprofen, indoramin, Indorenate Hydrochloride, Indoxole, Indriline Hydrochloride, infliximab, inocoterone, inogatran, inolimomab, Inositol Niacinate, Insulin, Interferon beta-1a, Intrazole, Intriptyline Hydrochloride, iobenguane, Iobenzamic Acid, iobitridol, Iodine, iodoamiloride, iododoxorubicin, iofratol, iomeprol, iopentol, iopromide, iopyrol, iotriside, ioxilan, ipazilide, ipenoxazone, ipidacrine, Ipodate Calcium, ipomeanol, Ipratropium, Ipratropium Bromide, ipriflavone, Iprindole, Iprofenin, Ipronidazole, Iproplatin, Iproxamine Hydrochloride, ipsapirone, irbesartan, irinotecan, irloxacin, iroplact, irsogladin, Irtemazole, isalsteine, Isamoxole, isbogrel, Isepamicin, isobengazole, Isobutamben, Isocarboxazid, Isoconazole, Isoetharine, isofloxythepin, Isoflupredone Acetate, Isoflurane, Isofluorophate, isohomohalicondrin B, Isoleucine, Isomazole Hydrochloride, Isomylamine Hydrochloride, Isoniazid, Isopropamide Iodide, Isopropyl Alcohol, isopropyl unoprostone, Isoproterenol Hydrochloride, Isosorbide, Isosorbide Mononitrate, Isotiquimide, Isotretinoin, Isoxepac, Isoxicam, Isoxsuprine Hydrochloride, isradipine, itameline, itasetron, Itazigrel, itopride, Itraconazole, Ivermectin, ixabepilone, jasplakinolide, Jemefloxacin, Jesopitron, Josamycin, kahalalide F, Kalafungin, Kanamycin Sulfate, ketamine, Ketanserin, Ketazocine, Ketazolam, Kethoxal, Ketipramine Fumarate, Ketoconazole, Ketoprofen, Ketorfanol, ketorolac, Ketotifen Fumarate, Kitasamycin, Labetalol Hydrochloride, Lacidipine, lacidipine, lactitol, lactivicin, Lactobionate, laennec, lafutidine, 1-alphahydroxyvitamin D2, lamellarin-N triacetate, lamifiban, Lamivudine, Lamotrigine, lanoconazole, Lanoxin, lanperisone, lanreotide, lanreotide acetate, Lansoprazole, lapatinib, laropiprant, latanoprost, lateritin, laurocapram, Lauryl Isoquinolinium Bromide, Lavoltidine Succinate, lazabemide, Lecimibide, leinamycin, lemildipine, leminoprazole, lenercept, Leniquinsin, lenograstim, Lenperone, lentinan sulfate, leptin, leptolstatin, lercanidipine, Lergotrile, lerisetron, Letimide Hydrochloride, letrazuril, letrozole, Leucine, leucomyzin, leuprolide, Leuprolide Acetate, leuprorelin, Levalbuterol, Levamfetamine Succinate, levamisole, Levdobutamine Lactobionate, Leveromakalim, levetiracetam, Leveycloserine, levobetaxolol, levobunolol, levobupivacaine, levocabastine, levocarnitine, levocetirizine, levocetirizine dihydrochloride, Levodopa, levodropropizine, levofloxacin, Levofuraltadone, Levoleucovorin Calcium, Levomethadyl Acetate, Levomethadyl Acetate Hydrochloride, levomoprolol, Levonantradol Hydrochloride, Levonordefrin, Levonorgestrel, Levopropoxyphene Napsylate, Levopropylcillin Potassium, levormeloxifene, Levorphanol Tartrate, levosimendan, levosulpiride, Levothyroxine, Levothyroxine Sodium, Levoxadrol Hydrochloride, Lexipafant, Lexithromycin, liarozole, Libenzapril, Lidamidine Hydrochloride, Lidocaine, Lidofenin, Lidoflazine, Lifarizin, Lifibrate, Lifibrol, Linarotene, Lincomycin, Linezolid, Linogliride, Linopirdine, linotroban, linsidomine, lintitript, lintopride, Liothyronine 1-125, liothyronine sodium, Liotrix, lirexapride, Lisdexamfetamine Dimesylate, lisinopril, Lispro insulin, lissoclinamide, Lixazinone Sulfate, lobaplatin, Lobenzarit Sodium, Lobucavir, locarmate Meglumine, locarmic Acid, locetamic Acid, lodamide, Lodelaben, lodipamide Meglumine, lodixanol, Iodoantipyrine I-131, Iodocholesterol I-131, Iodohippurate Sodium I-131, Iodopyracet I-125, Iodoquinol, Iodoxamate Meglumine, lodoxamide, Iodoxamie Acid, Lofemizole Hydrochloride, Lofentanil Oxalate, Lofepramine Hydrochloride, lofetamine Hydrochloride I-123, Lofexidine Hydrochloride, loglicic Acid, loglucol, loglucomide, loglycamic Acid, logulamide, lohexyl, lombricine, Lomefloxacin, lomerizine, lomethin I-125, Lometraline Hydrochloride, lometrexol, Lomofungin, Lomoxicam, Lomustine, Lonapalene, lonazolac, lonidamine, lopamidol, lopanoic Acid, Loperamide Hydrochloride, lophendylate, Lopinavir, loprocemic Acid, lopronic Acid, lopydol, lopydone, loracarbef, Lorajmine Hydrochloride, loratadine, Lorazepam, Lorbamate, Lorcamide Hydrochloride, Loreclezole, Loreinadol, lorglumide, Lormetazepam, Lornoxicam, lornoxicam, Lortalamine, Lorzafone, losartan, Losartan potassium, losefamic Acid, loseric Acid, losigamone, losoxantrone, losulamide Meglumine, Losulazine Hydrochloride, losumetic Acid, lotasul, loteprednol, lotetric Acid, lothalamate Sodium, lothalamic Acid, lotrolan, lotroxic Acid, lovastatin, loversol, loviride, loxagiate Sodium, loxaglate Meglumine, loxaglic Acid, Loxapine, Loxoribine, loxotrizoic Acid, lubeluzole, Lucanthone Hydrochloride, Lufironil, Lurosetron Mesylate, lurtotecan, lutetium, Lutrelin Acetate, luzindole, Lyapolate Sodium, Lycetamine, lydicamycin, Lydimycin, Lynestrenol, Lypressin, Lysine, lysofylline, lysostaphin, Maduramicin, Mafenide, magainin 2 amide, Magnesium Salicylate, Magnesium Sulfate, magnolol, maitansine, Malethamer, mallotoaponin, mallotochromene, Malotilate, malotilate, mangafodipir, manidipine, maniwamycin A, Mannitol, mannostatin A, manumycin E, manumycin F, mapinastine, Maprotiline, maraviroc, marimastat, Marinol, Masoprocol, maspin, massetolide, Maytansine, Mazapertine Succiniate, Mazindol, Mebendazole, Mebeverine Hydrochloride, Mebrofenin, Mebutamate, Mecamylamine Hydrochloride, Mechlorethamine Hydrochloride, meclizine hydrochloride, Meclocycline, Meclofenamate Sodium, Mecloqualone, Meclorisone Dibutyrate, Medazepam Hydrochloride, Medorinone, Medrogestone, Medroxalol, Medroxyprogesterone, Medrysone, Meelizine Hydrochloride, Mefenamic Acid, Mefenidil, Mefenorex Hydrochloride, Mefexamide, Mefloquine Hydrochloride, Mefruside, Megalomicin Potassium Phosphate, Megestrol Acetate, Meglumine, Meglutol, Melengestrol Acetate, Meloxicam, Melphalan, Memantine, Memotine Hydrochloride, Menabitan Hydrochloride, Menoctone, menogaril, Menotropins, Meobentine Sulfate, Mepartricin, Mepenzolate Bromide, Meperidine Hydrochloride, Mephentermine Sulfate, Mephenyloin, Mephobarbital, Mepivacaine Hydrochloride, Meprobamate, Meptazinol Hydrochloride, Mequidox, Meralein Sodium, merbarone, Mercaptopurine, Mercufenol Chloride, Merisoprol, Meropenem, Mesalamine, Meseclazone, Mesoridazine, Mesterolone, Mestranol, Mesuprine Hydrochloride, Metalol Hydrochloride, Metaproterenol Polistirex, Metaraminol Bitartrate, Metaxalone, Meteneprost, meterelin, Metformin, Methacholine Chloride, Methacycline, methadone, Methadyl Acetate, Methalthiazide, Methamphetamine Hydrochloride, Methaqualone, Methazolamide, Methdilazine, Methenamine, Methenolone Acetate, Methetoin, Methicillin Sodium, Methimazole, methioninase, Methionine, Methisazone, Methixene Hydrochloride, Methocarbamol, Methohexital Sodium, Methopholine, Methotrexate, Methotrimeprazine, methoxatone, methoxy polyethylene glycol-epoetin beta, Methoxyflurane, Methsuximide, Methyclothiazide, Methyl Palmoxirate, Methylatropine Nitrate, Methylbenzethonium Chloride, Methyldopa, Methyldopate Hydrochloride, Methylene Blue, Methylergonovine Maleate, methylhistamine, methylinosine monophosphate, Methylphenidate, Methylprednisolone, Methyltestosterone, Methynodiol Diacelate, Methysergide, Methysergide Maleate, Metiamide, Metiapine, Metioprim, metipamide, Metipranolol, Metizoline Hydrochloride, Metkephamid Acetate, metoclopramide, Metocurine Iodide, Metogest, Metolazone, Metopimazine, Metoprine, Metoprolol, Metoprolol tartrate, Metouizine, metrifonate, Metrizamide, Metrizoate Sodium, Metronidazole, Meturedepa, Metyrapone, Metyrosine, Mexiletine Hydrochloride, Mexrenoate Potassium, Mezlocillin, Mianserin Hydrochloride, mibefradil, Mibefradil Dihydrochloride, Mibolerone, michellamine B, Miconazole, microcolin A, Midaflur, Midazolam Hydrochloride, midodrine, mifepristone, Mifobate, miglitol, milacemide, milameline, mildronate, Milenperone, Milipertine, milnacipran, Milrinone, miltefosine, Mimbane Hydrochloride, minaprine, Minaxolone, Minocromil, Minocycline, Minocycline hydrochloride, Minoxidil, Mioflazine Hydrochloride, miokamycin, mipragoside, mirfentanil, mirimostim, Mirincamycin Hydrochloride, Mirisetron Maleate, Mirtazapine, Misonidazole, Misoprostol, Mitindomide, Mitocarcin, Mitocromin, Mitogillin, mitoguazone, mitolactol, Mitomalcin, Mitomycin, mitonafide, Mitosper, Mitotane, mitoxantrone, mivacurium chloride, mivazerol, mixanpril, Mixidine, mizolastine, mizoribine, Moclobemide, modafinil, Modaline Sulfate, Modecamide, moexipril, mofarotene, Mofegiline Hydrochloride, mofezolac, molgramostim, Molinazone, Molindone Hydrochloride, Molsidomine, mometasone, Monatepil Maleate, Monensin, Monoctanoin, montelukast, Montelukast Sodium, montirelin, mopidamol, moracizine, Morantel Tartrate, Moricizine, Morniflumate, Morphine, Morrhuate Sodium, mosapramine, mosapride, motilide, Motretinide, Moxalactam Disodium, Moxazocine, Moxifloxacin, moxiraprine, Moxnidazole, moxonidine, Mumps Skin Test Antigen, Muzolimine, mycaperoxide B, Mycophenolate mofetil, Mycophenolic Acid, myriaporone, Nabazenil, Nabilone, Nabitan Hydrochloride, Naboctate Hydrochloride, Nabumetone, N-acetyldinaline, Nadide, nadifloxacin, Nadolol, nadroparin calcium, nafadotride, nafamostat, nafarelin, Nafcillin Sodium, Nafenopin, Nafimidone Hydrochloride, Naflocort, Nafomine Malate, Nafoxidine Hydrochloride, Nafronyl Oxalate, Naftifine Hydrochloride, naftopidil, naglivan, nagrestip, Nalbuphine Hydrochloride, Nalidixate Sodium, Nalidixic Acid, nalmefene, Nalmexone Hydrochloride, naloxone, Naltrexone, Namoxyrate, Nandrolone Phenpropionate, Nantradol Hydrochloride, Napactadine Hydrochloride, napadisilate, Napamezole Hydrochloride, napaviin, Naphazoline Hydrochloride, naphterpin, Naproxen, Naproxen sodium, Naproxol, napsagatran, Naranol Hydrochloride, Narasin, naratriptan, nartograstim, nasaruplase, natalizumab, Natamycin, nateplase, Naxagolide Hydrochloride, Nebivolol, Nebramycin, nedaplatin, Nedocromil, Nefazodone Hydrochloride, Neflumozide Hydrochloride, Nefopam Hydrochloride, Nelezaprine Maleate, Nemazoline Hydrochloride, nemorubicin, Neomycin Palmitate, Neostigmine Bromide, neridronic acid, Netilmicin Sulfate, Neutramycin, Nevirapin Nexeridine Hydrochloride, Niacin, Nibroxane, Nicardipine Hydrochloride, Nicergoline, Niclosamide, Nicorandil, Nicotinamide, Nicotinyl Alcohol, Nifedipine, Nifirmerone, Nifluridide, Nifuradene, Nifuraldezone, Nifuratel, Nifuratrone, Nifurdazil, Nifurimide, Nifurpirinol, Nifurquinazol, Nifurthiazole, Nifurtimox, nilotinib, nilotinib hydrochloride monohydrate, nilutamide, Nilvadipine, Nimazone, Nimodipine, niperotidine, niravoline, Niridazole, nisamycin, Nisbuterol Mesylate, nisin, Nisobamate, Nisoldipine, Nisoxetin Nisterime Acetate, Nitarsone, nitazoxanide, nitecapone, Nitrafudam Hydrochloride, Nitralamine Hydrochloride, Nitramisole Hydrochloride, Nitrazepam, Nitrendipine, Nitrocydine, Nitrodan, Nitrofurantoin, Nitrofurazone, Nitroglycerin, Nitromersol, Nitromide, Nitromifene Citrate, Nitrous Oxide, nitroxide antioxidant, nitrullyn, Nivazol, Nivimedone Sodium, Nizatidine, Noberastine, Nocodazole, Nogalamycin, Nolinium Bromide, Nomifensine Maleate, Noracymethadol Hydrochloride, Norbolethone, Norepinephrine Bitartrate, Norethindrone, Norethynodrel, Norfurane, Norfloxacin, Norgestimate, Norgestomet, Norgestrel, Nortriptyline Hydrochloride, Noscapine, Novobiocin Nylestriol, Nystatin, Obidoxime Chloride, Ocaperidone, Ocfentanil Hydrochloride, Ocinaplon, Octanoic Acid, Octazamide, Octenidine Hydrochloride, Octodrine, Octreotide, Octriptyline Phosphate, Ofloxacin, Ofornine, okicenone, Olanzepine, Olmesartan, olmesartan medoxomil, olopatadine, olopatadine hydrochloride, olprinone, olsalazine, Olsalazine Sodium, Olvanil, Omalizumab, Omega-3 acid ethyl esters, omeprazole, onapristone, ondansetron, Ontazolast, Oocyte Opipramol Hydrochloride, oracin, Orconazole Nitrate, Orgotein, Orlislat, Ormaplatin, Ormetoprim, Ornidazole, Orpanoxin, Orphenadrine Citrate, osaterone, Oseltamivir, otenzepad, Oxacillin Sodium, Oxagrelate, oxaliplatin, Oxamarin Hydrochloride, oxamisole, Oxamniquine, oxandrolone, Oxantel Pamoate, Oxaprotiline Hydrochloride, Oxaprozin, Oxarbazole, Oxatomide, oxaunomycin, Oxazepam, oxcarbazepine, Oxendolone, Oxethazaine, Oxetorone Fumarate, Oxfendazole, Oxfenicine, Oxibendazole, oxiconazole, Oxidopamine, Oxidronic Acid, Oxifungin Hydrochloride, Oxilorphan, Oximonam, Oximonam Sodium, Oxiperomide, oxiracetam, Oxiramide, Oxisuran, Oxmetidine Hydrochloride, oxodipine, Oxogestone Phenopropionate, Oxolinic Acid, Oxprenolol Hydrochloride, Oxtriphylline, Oxybutynin Chloride, Oxychlorosene, Oxycodone, oxycodone hydrochloride, Oxymetazoline Hydrochloride, oxymetholone, Oxymorphone Hydrochloride, Oxypertine, Oxyphenbutazone, Oxypurinol, Oxytetracycline, Oxytocin, ozagrel, Ozlinone, Paclitaxel, palauamine, Paldimycin, palinavir, Palivizumab, palmitoylrhizoxin, Palmoxirate Sodium, pamaqueside, Pamatolol Sulfate, pamicogrel, Pamidronate Disodium, pamidronic acid, Panadiplon, panamesine, panaxytriol, Pancopride, Pancuronium Bromide, panipenem, pannorin, panomifene, pantethine, pantoprazole, Papaverine Hydrochloride, parabactin, paracetamol, Parachlorophenol, Paraldehyde, Paramethasone Acetate, Paranyline Hydrochloride, Parapenzolate Bromide, Pararosaniline Pamoate, Parbendazole, Parconazole Hydrochloride, Paregoric, Pareptide Sulfate, Pargyline Hydrochloride, parnaparin sodium, Paromomycin Sulfate, Paroxetine, paroxetine hydrochloride, parthenolide, Partricin, Paulomycin, pazelliptine, Pazinaclone, Pazoxide, pazufloxacin, pefloxacin, pegaspargase, Pegorgotein, Pegylated interferon alfa-2a, Pelanserin Hydrochloride, peldesine, Peliomycipelretin, Pelrinone Hydrochloride, Pemedolac, Pemerid Nitrate, Pemetrexed, pemirolast, Pemoline, Penamecillin, Penbutolol Sulfate, Penciclovir, Penfluridol, Penicillamine, Penicillin G Benzathine, Penicillin G Potassium, Penicillin G Procaine, Penicillin G Sodium, Penicillin V Hydrabamine, Penicillin V Benzathine, Penicillin V Potassium, Pentabamate, Pentaerythritol Tetranitrate, pentafuside, pentamidine, pentamorphone, Pentamustine, Pentapiperium Methylsulfate, Pentazocine, Pentetic Acid, Pentiapine Maleate, pentigetide, Pentisomicin, Pentizidone Sodium, Pentobarbital, Pentomone, Pentopril, pentosan, pentostatin, Pentoxifylline, Pentrinitrol, pentrozole, Peplomycin Sulfate, Pepstatin, perflubron, perfofamide, Perfosfamide, pergolide, Perhexyline Maleate, perillyl alcohol, Perindopril, perindoprilat, Perlapin Permethrin, perospirone, Perphenazine, Phenacemide, phenaridine, phenazinomycin, Phenazopyridine Hydrochloride, Phenbutazone Sodium Glycerate, Phencarbamide, Phencyclidine Hydrochloride, Phendimetrazine Tartrate, Phenelzine Sulfate, Phenformin, Phenmetrazine Hydrochloride, Phenobarbital, Phenoxybenzamine Hydrochloride, Phenprocoumon, phenserine, phensuccinal, Phensuximide, Phentermine, Phentermine Hydrochloride, phentolamine mesilate, Phentoxifylline, Phenyl Aminosalicylate, phenylacetate, Phenylalanine, phenylalanylketoconazole, Phenylbutazone, Phenylephrine Hydrochloride, Phenylpropanolamine Hydrochloride, Phenylpropanolamine Polistirex, Phenyramidol Hydrochloride, Phenyloin, Phenyloin sodium, Physostigmine, picenadol, picibanil, Picotrin Diolamine, picroliv, picumeterol, pidotimod, Pifarnine, Pilocarpine, pilsicamide, pimagedine, Pimetine Hydrochloride, pimilprost, Pimobendan, Pimozide, Pinacidil, Pinadoline, Pindolol, pinnenol, pinocebrin, Pinoxepin Hydrochloride, pioglitazone, Pipamperone, Pipazethate, pipecuronium bromide, Piperacetazine, Piperacillin, Piperacillin Sodium, Piperamide Maleate, piperazinc, Pipobroman, Piposulfan, Pipotiazine Palmitate, Pipoxolan Hydrochloride, Piprozolin, Piquindone Hydrochloride, Piquizil Hydrochloride, Piracetam, Pirandamine Hydrochloride, pirarubicin, Pirazmonam Sodium, Pirazolac, Pirbenicillin Sodium, Pirbuterol Acetate, Pirenperone, Pirenzepine Hydrochloride, piretanide, Pirfenidone, Piridicillin Sodium, Piridronate Sodium, Piriprost, piritrexim, Pirlimycin Hydrochloride, pirlindole, pirmagrel, Pirmenol Hydrochloride, Pirnabine, Piroctone, Pirodavir, pirodomast, Pirogliride Tartrate, Pirolate, Pirolazamide, Piroxantrone Hydrochloride, Piroxicam, Piroximone, Pirprofen, Pirquinozol, Pirsidomine, Pivampicillin Hydrochloride, Pivopril, Pizotyline, placetin A, Plicamycin, Plomestane, Pobilukast Edamine, Podofilox, Poisonoak Extract, Poldine Methylsulfate, Poliglusam, Polignate Sodium, Polymyxin B Sulfate, Polythiazide, Ponalrestat, Porfimer Sodium, Porfiromycin, Potassium Chloride, Potassium Iodide, Potassium Permanganate, Povidone-Iodine, Practolol, Pralidoxime Chloride, Pramipexole, Pramiracetam Hydrochloride, Pramoxine Hydrochloride, Pranolium Chloride, Pravadoline Maleate, Pravastatin, Pravastatin sodium, Prazepam, Prazosin, Prazosin Hydrochloride, Prednazate, Prednicarbate, Prednimustine, Prednisolone, prednisolone quetiapine fumerate, Prednisone, Prednival, Pregabalin, Pregnenolone Succiniate, Prenalterol Hydrochloride, Prenylamine, Pridefine Hydrochloride, Prifelone, Prilocalne Hydrochloride, Prilosec, Primaquine Phosphate, Primidolol, Primidone, Prinivil, Prinomide Tromethamine, Prinoxodan, pritosufloxacin, Prizidilol Hydrochloride, Proadifen Hydrochloride, Probenecid, Probicromil Calcium, Probucol, Procainamide Hydrochloride, Procaine Hydrochloride, Procarbazine Hydrochloride, Procaterol Hydrochloride, Prochlorperazine, Procinonide, Proclonol, Procyclidine Hydrochloride, Prodilidine Hydrochloride, Prodolic Acid, Profadol Hydrochloride, Progabide, Progesterone, Proglumide, Proinsulin (human), Proline, Prolintane Hydrochloride, Promazine Hydrochloride, Promethazine, Promethazine hydrochloride, Propafenone Hydrochloride, propagermanium, Propanidid, Propantheline Bromide, Proparacaine Hydrochloride, Propatyl Nitrate, propentofylline, Propenzolate Hydrochloride, Propikacin, Propiomazine, Propionic Acid, propionylcarnitine, propiram, propiram, propiverine, Propofol, Proponolol hydrochloride, Propoxycaine Hydrochloride, Propoxyphene Hydrochloride, Propranolol Hydrochloride, Propulsid, propylbis-acridone, Propylhexedrine, Propyliodone, Propylthiouracil, Proquazone, Prorenoate Potassium, Proroxan Hydrochloride, Proscillaridin, Prostalene, prostratin, Protamine Sulfate, protegrin, Protirelin, Protriptyline Hydrochloride, Proxazole, Proxazole Citrate, Proxicromil, Proxorphan Tartrate, prulifloxacin, pseudoephedrine, Pseudophedrine hydrochloride, Puromycin, Pyrabrom, Pyrantel Pamoate, Pyrazinamide, Pyrazofurin, pyrazoloacridine, Pyridostigmine Bromide, Pyridoxine hydrochloride, Pyrilamine Maleate, Pyrimethamine, Pyrinoline, Pyrithione Sodium, Pyrithione Zinc, Pyrovalerone Hydrochloride, Pyroxamine Maleate, Pyrrocaine, Pyrroliphene Hydrochloride, Pyrrolnitrin, Pyrvinium Pamoate, Quadazocine Mesylate, Quazepam, Quazinone, Quazodine, Quazolast, quetiapine, quetiapine fumarate, quiflapon, quinagolide, Quinaldine Blue, quinapril, Quinapril hydrochloride, Quinazosin Hydrochloride, Quinbolone, Quinctolate, Quindecamine Acetate, Quindonium Bromide, Quinelorane Hydrochloride, Quinestrol, Quinfamide, Quingestanol Acetate, Quingestrone, Quinidine Gluconate, Quinielorane Hydrochloride, Quinine Sulfate, Quinpirole Hydrochloride, Quinterenol Sulfate, Quinuclium Bromide, Quinupristin, Quipazine Maleate, Rabeprazole, Rabeprazole Sodium, Racephenicol, Racepinephrine, Rafoxanide, Ralitoline, raloxifene, raltegravir, raltitrexed, ramatroban, Ramipril, Ramoplanin, ramosetron, ranelic acid, Ranimycin, Ranitidine, Ranitidine hydrochloride, ranolazine, Rauwolfia Serpentina, recainam, Recainam Hydrochloride, Reclazepam, Recombinant factor VIII, regavirumab, Regramostim, Relaxin, Relomycin, Remacemide Hydrochloride, Remifentanil Hydrochloride, Remiprostol, Remoxipride, Repirinast, Repromicin, Reproterol Hydrochloride, Reserpine, resinferatoxin, Resorcinol, retapamulin, retelliptine demethylated, reticulon, reviparin sodium, revizinone, rhenium etidronate, rhizoxin, RI retinamide, Ribaminol, Ribavirin, Riboprine, ricasetron, Ridogrel, Rifabutin, Rifametane, Rifamexil, Rifamide, Rifampin, Rifapentine, Rifaximin, rilopirox, Riluzole, rimantadine, Rimcazole Hydrochloride, Rimexolone, Rimiterol Hydrobromide, Rimonabant, rimoprogin, riodipine, Rioprostil, Ripazepam, ripisartan, Risedronate, Risedronate Sodium, risedronic acid, Risocaine, Risotilide Hydrochloride, rispenzepine, Risperdal, Risperidone, Ritanserin, ritipenem, Ritodrine, Ritolukast, ritonavir, rituximab, rivastigmine, rivastigmine tartrate, Rizatriptan, rizatriptan benzoate, Rocastine Hydrochloride, Rocuronium Bromide, Rodocaine, Roflurane, Rogletimide, rohitukine, rokitamycin, Roletamicide, Rolgamidine, Rolicyprine, Rolipram, Rolitetracycline, Rolodine, Romazarit, romurtide, Ronidazole, Ropinirole, Ropitoin Hydrochloride, ropivacaine, Ropizine, roquinimex, Rosaramicin, rosiglitazone, Rosiglitazone maleate, Rosoxacin, Rosuvastatin, Rotavirus vaccine, rotigotine, Rotoxamine, roxaitidine, Roxarsone, roxindole, roxithromycin, rubiginone B1, ruboxyl, rufloxacin, rupatidine, Rutamycin, ruzadolane, Sabeluzole, safingol, safironil, saintopin, salbutamol, Salbutamol sulfate, Salcolex, Salethamide Maleate, Salicyl Alcohol, Salicylamide, Salicylate Meglumine, Salicylic Acid, Salmeterol, Salnacediin, Salsalate, sameridine, sampatrilat, Sancycline, sanfetrinem, Sanguinarium Chloride, Saperconazole, saprisartan, sapropterin, sapropterin dihydrochloride, saquinavir, Sarafloxacin Hydrochloride, Saralasin Acetate, sarcophytol A, sargramostim, Sarmoxicillin, Sarpicillin, sarpogrelate, saruplase, saterinone, satigrel, satumomab pendetide, Scopafungin, Scopolamine Hydrobromide, Scrazaipine Hydrochloride, Secalciferol, Secobarbital, Seelzone, segiline, Seglitide Acetate, Selegiline Hydrochloride, Selenium Sulfide, Selenomethionine Se-75, Selfotel, sematilide, semduramicin, semotiadil, semustine, Sepazonium Chloride, Seperidol Hydrochloride, Seprilose, Seproxetine Hydrochloride, Seractide Acetate, Sergolexole Maleate, Serine, Sermetacin, Sermorelin Acetate, sertaconazole, sertindole, sertraline, sertraline hydrochloride, S-ethynyluracil, setiptiline, Setoperone, Sevelamer, sevirumab, sevoflurane, sezolamide, Sibopirdine, Sibutramine Hydrochloride, Silandrone, Sildenafil, sildenafil citrate, silipide, silteplase, Silver Nitrate, simendan, Simtrazene, Simvastatin, Sincalide, Sinefungin, sinitrodil, sinnabidol, sipatrigine, sirolimus, Sisomicin, Sitagliptin, Sitogluside, sizofuran, sobuzoxane, Sodium Amylosulfate, Sodium Iodide I-123, Sodium Nitroprusside, Sodium Oxybate, sodium phenylacetate, Sodium Salicylate, Sodium valproate, Solifenacin, solverol, Solypertine Tartrate, Somalapor, Somantadine Hydrochloride, somatomedin B, somatomedin C, Somatostatin, somatrem, somatropin, Somenopor, Somidobove, Sorbinil, Sorivudine, sotalol, Soterenol Hydrochloride, Sparfioxacin, Sparfosate Sodium, sparfosic acid, Sparsomy, Sparteine Sulfate, Spectinomycin Hydrochloride, spicamycin D, Spiperone, Spiradoline Mesylate, Spiramycin, Spirapril Hydrochloride, Spiraprilat, Spirogermanium Hydrochloride, Spiromustine, Spironolactone, Spiroplatin, Spiroxasone, splenopentin, spongistatin, Sprodiamide, squalamine, Stallimycin Hydrochloride, Stannous Pyrophosphate, Stannous Sulfur Colloid, Stanozolol, Statolon, staurosporine, stavudine, Steffimycin, Stenbolone Acetate, stepronin, Stilbazium Iodide, Stilonium Iodide, stipiamide, Stiripentol, stobadine, Streptomycin Sulfate, Streptonicozid, Streptonigrin, Streptozocin, Strontium Chloride Sr-89, succibun, Succimer, Succinylcholine Chloride, Sucralfate, Sucrosofate Potassium, Sudoxicam, Sufentanil, Sufotidine, Sulazepam, Sulbactam Pivoxil, Sulconazole Nitrate, Sulfabenz, Sulfabenzamide, Sulfacetamide, Sulfacytine, Sulfadiazine, Sulfadoxine, Sulfalene, Sulfamerazine, Sulfameter, Sulfamethazine, Sulfamethizole, Sulfamethoxazole, Sulfamonomethoxine, Sulfamoxole, Sulfanilate Zinc, Sulfanitran, sulfasalazine, Sulfasomizole, Sulfazamet, Sulfinalol Hydrochloride, sulfinosine, Sulfinpyrazone, Sulfisoxazole, Sulfomethoxazole, Sulfomyxin, Sulfonterol Hydrochloride, sulfoxamine, Sulinldac, Sulmarin, Sulnidazole, Suloctidil, Sulofenur, sulopenem, Suloxifen Oxalate, Sulpiride, Sulprostone, sultamicillin, Sulthiame, sultopride, sulukast, Sumarotene, sumatriptan, Sumatriptan succinate, Suncillin Sodium, Suproclone, Suprofen, suradista, suramin, Surfomer, Suricamide Maleate, Suritozole, Suronacrine Maleate, Suxemerid Sulfate, swainsonine, symakalim, Symclosene, Symetine Hydrochloride, Taciamine Hydrochloride, Tacrine Hydrochloride, Tacrolimus, Tadalafil, Talampicillin Hydrochloride, Taleranol, Talisomycin, tallimustine, Talmetacin, Talniflumate, Talopram Hydrochloride, Talosalate, Tametraline Hydrochloride, Tamoxifen, tamoxifen citrate, Tampramine Fumarate, Tamsulosin, Tamsulosin Hydrochloride, Tandamine Hydrochloride, tandospirone, tapgen, taprostene, Tasosartan, tauromustine, Taxane, Taxoid, Tazadolene Succinate, tazanolast, tazarotene, Tazifylline Hydrochloride, Tazobactam, Tazofelone, Tazolol Hydrochloride, Tebufelone, Tebuquine, Teclozan, Tecogalan Sodium, Teecleukin, Teflurane, Tegafur, Tegaserod, Tegretol, Teicoplanin, telenzepine, tellurapyrylium, telmesteine, telmisartan, Teloxantrone Hydrochloride, Teludipine Hydrochloride, Temafloxacin Hydrochloride, Tematropium Methyl sulfate, Temazepam, Temelastine, temocapril, Temocillin, temoporfin, temozolomide, temsirolimus, Tenidap, Teniposide, Tenofovir, tenosal, tenoxicam, tepirindole, Tepoxalin, Teprotide, terazosin, Terazosin Hydrochloride, Terbinafine, Terbutaline Sulfate, Terconazole, terfenadine, terfiavoxate, terguride, Teriparatide, Teriparatide Acetate, terlakiren, terlipressin, terodiline, Teroxalene Hydrochloride, Teroxirone, tertatolol, Tesicam, Tesimide, Testolactone, Testosterone, Tetracaine, tetrachlorodecaoxide, Tetracycline, Tetracycline hydrochloride, Tetrahydrozoline Hydrochloride, Tetramisole Hydrochloride, Tetrazolast Meglumine, tetrazomine, Tetrofosmin, Tetroquinone, Tetroxoprim, Tetrydamine, thaliblastine, Thalidomide, Theofibrate, Theophylline, Thiabendazole, Thiamiprine, Thiamphenicol, Thiamylal, Thiazesim Hydrochloride, Thiazinamium Chloride, Thiethylperazine, Thiithixene, Thimerfonate Sodium, Thimerosal, thiocoraline, thiofedrine, Thioguanine, thiomarinol, Thiopental Sodium, thioperamide, Thioridazine, Thiotepa, Thiphenamil Hydrochloride, Thiphencillin Potassium, Thiram, Thozalinone, Threonine, Thrombin, thrombopoietin, thymalfasin, thymopentin, thymotrinan, Thyromedan Hydrochloride, Thyroxine, Tiacrilast, Tiacrilast Sodium, tiagabine, Tiamenidine, tianeptine, tiapafant, Tiapamil Hydrochloride, Tiaramide Hydrochloride, Tiazofurin, Tibenelast Sodium, Tibolone, Tibric Acid, Ticabesone Propionate, Ticarbodine, Ticarcillin Cresyl Sodium, Ticlatone, ticlopidine, Ticrynafen, tienoxolol, Tifurac Sodium, Tigemonam Dicholine, Tigestol, Tiletamine Hydrochloride, Tilidine Hydrochloride, tilisolol, tilnoprofenarbamel, Tilorone Hydrochloride, Tiludronate Disodium, tiludronic acid, Timefurone, Timobesone Acetate, Timolol, Timolol meleate, Tinabinol, Timidazole, Tinzaparin Sodium, Tioconazole, Tiodazosin, Tiodonium Chloride, Tioperidone Hydrochloride, Tiopinac, Tiospirone Hydrochloride, Tiotidine, Tiotropium, tiotropium bromide, Tioxidazole, Tipentosin Hydrochloride, tipranavir, Tipredane, Tiprenolol Hydrochloride, Tiprinast Meglumine, Tipropidil Hydrochloride, Tiqueside, Tiquinamide Hydrochloride, tirandalydigin, Tirapazamine, tirilazad, tirofiban, tiropramide, titanocene dichloride, Tixanox, Tixocortol Pivalate, Tizanidine Hydrochloride, Tnmethobenzamide Hydrochloride, Tobramycin, Tocamide, Tocamphyl, Tofenacin Hydrochloride, Tolamolol, Tolazamide, Tolazoline Hydrochloride, Tolbutamide, Tolcapone, Tolciclate, Tolfamide, Tolgabide, Tolimidone, Tolindate, Tolmetin, Tolnaftate, Tolpovidone, Tolpyrramide, Tolrestat, Tolterodine, tolterodine tartrate, Tomelukast, Tomoxetine Hydrochloride, Tonazocine Mesylate, Topiramate, topotecan, Topotecan Hydrochloride, topsentin, Topterone, Toquizine, torasemide, toremifene, Torsemide, Tosifen, Tosufloxacin, totipotent stem cell factor (TSCF), Tracazolate, trafermin, Tralonide, Tramadol, Tramadol Hydrochloride, Tramazoline Hydrochloride, trandolapril, Tranexamic Acid, Tranilast, Transcamide, trastuzumab, traxanox, Trazodone Hydrochloride, Trebenzomine Hydrochloride, Trefentanil Hydrochloride, Treloxinate, Trepipam Maleate, Trestolone Acetate, tretinoin, Triacetin, triacetyluridine, Triafungin, Triamcinolone, Triampyzine Sulfate, Triamterene, Triazolam, Tribenoside, tricaprilin, Tricetamide, Trichlormethiazide, trichohyalin, triciribine, Tricitrates, Triclofenol piperazine, Triclofos Sodium, trientine, Trifenagrel, triflavin, Triflocin, Triflubazam, Triflumidate, Trifluoperazine Hydrochloride, Trifluperidol, Triflupromazine, Triflupromazine Hydrochloride, Trifluridine, Trihexyphenidyl Hydrochloride, Trilostane, Trimazosin Hydrochloride, trimegestone, Trimeprazine Tartrate, Trimethadione, Trimethaphan Camsylate, Trimethoprim, Trimetozine, Trimetrexate, Trimipramine, Trimoprostil, Trimoxamine Hydrochloride, Triolein, Trioxifene Mesylate, Tripamide, Tripelennamine Hydrochloride, Triprolidine Hydrochloride, Triptorelin, Trisulfapyrimidines, Troclosene Potassium, troglitazone, Trolamine, Troleandomycin, trombodipine, trometamol, Tropanserin Hydrochloride, Tropicamide, tropine, tropisetron, trospectomycin, trovafloxacin, trovirdine, Tryptophan, Tuberculin, Tubocurarine Chloride, Tubulozole Hydrochloride, tucarcsol, tulobuterol, turosteride, Tybamate, tylogenin, Tyropanoate Sodium, Tyrosine, Tyrothricin, tyrphostins, ubenimex, Uldazepam, Undecylenic Acid, Uracil Mustard, urapidil, Urea, Uredepa, uridine triphosphate, Urofollitropin, Urokinase, Ursodiol, valaciclovir, Valacyclovir hydrochloride, Valine, Valnoctamide, Valproate semisodium, Valproic Acid, valsartan, vamicamide, vanadeine, Vancomycin, vaminolol, Vapiprost Hydrochloride, Vapreotide, Vardenafil, Varenicline, variolin B, Vasopressin, Vecuronium Bromide, velaresol, Velnacrine Maleate, venlafaxine, Venlafaxine hydrochloride, Veradoline Hydrochloride, veramine, Verapamil Hydrochloride, verdins, Verilopam Hydrochloride, Verlukast, Verofylline, veroxan, verteporfin, Vesnarinone, vexibinol, Vidarabine, vigabatrin, vildagliptin, Viloxazine Hydrochloride, Vinblastine Sulfate, vinburnine citrate, Vincofos, vinconate, Vincristine Sulfate, Vindesine, Vindesine Sulfate, Vinepidine Sulfate, Vinglycinate Sulfate, Vinleurosine Sulfate, vinorelbine, vinpocetine, vintoperol, vinxaltine, Vinzolidine Sulfate, Viprostol, Virginiamycin, Viridofulvin, Viroxime, vitaxin, Voglibose, Volazocine, voriconazole, vorozole, voxergolide, Wafarin, Xamoterol, Xanomeline, Xanoxate Sodium, Xanthinol Niacinate, xemiloflban, Xenalipin, Xenbucin, Xilobam, ximoprofen, Xipamide, Xorphanol Mesylate, Xylamidine Tosylate, Xylazine Hydrochloride, Xylometazoline Hydrochloride, xylose, yangambin, zabicipril, zacopride, zafirlukast, Zalcitabine, Zaleplon, zalospirone, Zaltidine Hydrochloride, zaltoprofen, zanamivir, zankiren, zanoterone, Zantac, Zarirlukast, zatebradine, zatosetron, Zatosetron Maleate, zenarestat, Zenazocine Mesylate, Zeniplatin, Zeranol, Zidometacin, Zidovudine, zifrosilone, Zilantel, zilascorb, zileuton, Zimeldine Hydrochloride, Zinc Undecylenate, Zindotrine, Zinoconazole Hydrochloride, Zinostatin, Zinterol Hydrochloride, Zinviroxime, ziprasidone, Zobolt, Zofenopril Calcium, Zofenoprilat, Zolamine Hydrochloride, Zolazepam Hydrochloride, Zoledronate, Zolertine Hydrochloride, zolmitriptan, zolpidem, Zomepirac Sodium, Zometapine, Zoniclezole Hydrochloride, Zonisamide, zopiclone, Zopolrestat, Zorbamyciin, Zorubicin Hydrochloride, zotepine, Zucapsaicin, and pharmaceutically acceptable salts thereof.
REFERENCES
[0060] The following references are incorporated herein by reference:
The Journal of Urology, Vol. 160, 1572-1575, October 1998; Sato “Restoration of Sexual Behavior and Dopaminergic Neurotransmission by Long Term Exogenous Testosterone Replacement in Male Rats.” Yonago Acta medica 2005; 48:93-99; S. Morizane “Effects of Testosterone Replacement on Lower Urinary Tract Functions in Elderly Male Rats.” U.S. Patent Publication 20100152699 WIPO Patent Publication WO/2011/146699
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Devices and methods for administering a therapeutic agent, comprising an implantable delivery device. Exemplary embodiments comprise a reservoir in fluid communication with a channeled member, and a compound comprising the therapeutic agent and a solubilizer disposed within the reservoir.
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This application is a continuation-in-part of patent application Ser. No. 677,273 filed on Dec. 3, 1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to aircraft deicers and more particularly to an improved inflatable deicer or boot adapted for attachment to the airfoil of an aircraft for use in retarding the accumulation of ice or to remove or break up ice accumulation.
Aircraft inflatable deicers, pads or boots are made of resilient material such as rubber and attached to the leading edge of an airfoil and extend rearwardly therefrom. The deicer has a series of inflatable passages or tubes which are distended by inflation pressure to break up ice accumulation which tends to form on the surface of the deicer. The passages or tubes are deflated by releasing the pressure medium and drawing a vacuum thereon. The normal sequence of operation is a continuous cycling of the inflation and deflation process. The present invention is an improvement on the structure and operation of prior deicers wherein the invention recognizes the need to differentiate between the stagnation line and the leading edge of an airfoil. The stagnation line of the wing of an aircraft is the line along which the air separates above and below such line on the wing whereas the leading edge of the wing is the foreward most edge of the wing. In the case of a symmetrical wing, the leading edge and the stagnation line are the same; however, in the case of a non-symmetrical or asymmetrical wing, the stagnation line is either below or above the leading edge of the wing. The present invention locates the deicer's inflatable tubes above and below the stagnation line while leaving the area immediately adjacent the stagnation line free of inflatable tubes. The advantage of this construction is a clamshell effect which takes place on the ice when the inflatable tubes on each side of the stagnation line inflate causing the ice to break in the non-inflatable area around the stagnation line. The wind stream over the airfoil then removes the ice build-up from the airfoil's leading edge. On some asymmetrical airfoils wherein the deicer is constructed in a conventional manner so that the inflatable tubes are also located on or immediately adjacent the stagnation line, the ice is not broken because the inflation tube pushes the ice cap forwardly before it breaks. The ice cap is then held onto the airfoil by the airstream. This in effect does not take advantage of the clamshell type of breaking which is so effective in a symmetrical as well as a non-symmetrical type of airfoil construction. The method of de-icing the airfoil can be improved by use of a deicer as described above, employing inflatable tubes on opposite side of the stagnation line by first inflating all of the tubes, the first set, on one side of the stagnation line and thence deflating such first set of tubes and simultaneously inflating all of the tubes, the second set, on the other side of the stagnation line, and thence repeating this cycle. The above construction of the deicer is particularly economical and effective in its deicing operation while requiring a minimum of power consumption.
SUMMARY OF THE INVENTION
The present invention is directed to a deicer pad or boot that is mounted on the forwardly disposed edge of an airfoil. Such deicer pad has the intermediate portion along the stagnation line devoid of inflatable tubes but two spaced apart portions above and below this intermediate portion which are inflated sequentially or simultaneously to effectively deice the airfoil.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of an airplane with a pneumatic deicer mounted upon the leading edge of the wing.
FIG. 2 is a plan view of a deicer boot with the position of the inflation passageways being shown in dotted lines.
FIG. 3 is a cross-sectional view of a portion of the deicer or deicer boot mounted on an asymmetrical airfoil with the inflation tubes or passageways in distended condition.
FIG. 4 is a cross-sectional view of a portion of the deicer or deicer boot mounted on a symmetrical airfoil with all of the inflation tubes or passageways in distended condition.
DETAILED DESCRIPTION
Referring to the drawings wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIGS. 1 and 2 a deicer boot or pad 10 mounted on the leading edge of a wing 12 of an aircraft 13, only partial shown. The wing 12 is attached to the fuselage 14 of such aircraft 13. Although the invention is described with respect to a wing 12, it is equally applicable to a tail section or an airfoil of an aircraft
The deicer pad 10, shown in FIGS. 2 and 3, is mounted on a non-symmetrical wing 12 and extends rearwardly from the leading edge 15--15 over a portion of the upper and lower surface portions of the wing 12. The deicer pad 10 is a laminated structure having an inner ply 16 (FIG. 3) that is essentially a rectangular section of rubber or other resilient rubber-like material that tapers as the other layers to be described at the respective side edges to facilitate the installation on the wing 12 as by cementing it to the airfoil and thereby not interfering with the aerodynamic effects of the wing design. In lieu of tapering the plies, the plies can have rectangular sides that fit snugly into recessed portions on the wing and similarly cemented to the airfoil. Such deicer pad 10 and ply 16 have a stagnation line 17--17 spaced from the leading edge 15--15. Such stagnation line is the line along which the air separates above and below the wing and in the example shown is generally parallel to the leading edge of the wing. Such ply 16 may be a woven textile fabric which is suitably coated with a suitable rubber compound to make this ply 16 air impervious. The inside of the plies forming the passageways to be described may have a heavy nap to facilitate the flow of air thereabove. Such nap or fibers collectively prevent complete closure and direct contact between opposing internal surfaces of the passageways to be described when the deicer pad is deflated, but have interstices through which residual air in the Passageways may be vented or pumped as by a vacuum. By such uniform distribution of nap or fibers, the external surface of the deicer pad is smooth and regular when the passageways are deflated and flattened. The terms spanwise and chordwise are used herein to designate the general direction of the passageways within the deicer pad as orientated on the aircraft's wing. Spanwise is in a direction generally parallel to the leading edge or the stagnation line of the aircraft's wing while chordwise is along a line extending transversely from the leading edge or stagnation line of the airfoil to the trailing edge of the airfoil. A ply 19 (FIG. 3) of tricot fabric overlays ply 16 and is adhered to the central portion of such ply 16 including along the leading edge 15--15 and stagnation line 17--17. The plies 16 and 19 are then adhered or bonded along the outer edge portions to form a unitary deicer.
Using the stagnation line 17--17 as a basis, three parallel spanwise passageways 20, 21 and 22 are formed by stitching the plies 16 and 19 together along parallel lines or by suitably bonding such plies along parallel lines to form such passageways which are distendable. In lieu of stitching or bonding such plies to form such passageways, separate tubes may be used. The inside of ply 19 may be napped as ply 16 to facilitate the flow of air to and from such passageways 20, 21 and 22.
That portion of the deicer pad that lies below the stagnation line 17--17 has four parallel spanwise passageways 25, 26, 27 and 28 formed by stitching the plies 16 and 19 together along parallel lines or by suitably bonding such plies along such parallel lines to form such passageways which are distendable in contrast to the non-distendable intermediate portion. In lieu of forming such Passageways 25 through 28 by stitching or bonding, separate inflatable tubes may be used. Such stitched spanwise passageways are sealed and together with passageways 20, 21 and 22 are pressurized and evacuated by separate manifolds 30 and 31, respectively. As seen in FIG. 2, the manifolds are located closely adjacent the outer extremity of the deicer pad. Each manifold 30 and 31 may be provided with an interior napped surface as with short flexible fibers of uniform thickness to prevent complete closure. To inflate the manifolds 30 and 31 and their corresponding passageways 20 through 22 and 25 through 28 suitable conduits are connected thereto and to a suitable air pressure source and a suitable vacuum source.
Those passageways 20 through 22 located above the stagnation line 17--17 define a first set of inflatable passageways in the upper deicer portion and those passageways 25 through 28 located below the stagnation line 17--17 define a second set of inflatable passageways in the lower deicer portion. The area of the deicer immediately below and above the stagnation line 17--17 is completely void of inflatable tubes or passageways and defines an intermediate portion. Thus there are three separate and distinct portions, areas or sections of the deicer, the central intermediate portion, the upper portion and the lower portion as depicted by FIG. 3. Each of these separate portions may be considered a region wherein a region is defined as one of the major subdivisions into which the entire body is divided into and thus the intermediate portion is the central or intermediate region devoid of inflatable tubes and is non-extensible with the upper extensible region having inflatable passageway 20, 21 and 22 and with the lower extensible region having inflatable passageways 25 through 28. In the example shown in FIGS. 2 and 3, the linear distance along the deicer from the stagnation line to where the first portion of passageway 25 is located is approximately one-half (1/2) inch; while the linear distance along the deicer from the stagnation line to where the first portion of passageway 25 is located is approximately one-half (1/2) inch. These dimensions will vary in accordance with the size of the wing and type of wing and can be much greater in magnitude.
A modification of the described invention is shown in FIG. 4 wherein a deicer pad 35 is shown as mounted on a symmetrical airfoil 36 having a stagnation line 37--37 coincident with leading edge. The deicer pad 35 is a laminated structure substantially as described in the first embodiment having an inner ply 38 that is essentially a rectangular section of rubber or other resilient rubber-like material that tapers as the other layers to be described at the respective side edges to facilitate the installation on the airfoil 36. In lieu of tapering the plies, the plies can have rectangular sides that fit snugly into recessed portions on the airfoil. Such ply 38 may be a woven textile fabric which is coated with a suitable rubber compound to make such ply air impervious. A ply 39 of tricot fabric overlays ply 38 and is adhered to airfoil 36 above and below the stagnation line an equal distance as shown in FIG. 4. The plies 38 and 39 are then adhered, bonded or stitched along the upper portion forming three parallel spanwise passageways 40, 41 and 42 as in the first embodiment. Separate tubes may be used to form these Passageways.
That portion of the deicer pad below the stagnation line 37--37 has five parallel spanwise passageways 45, 46, 47, 48 and 49 formed by stitching the plies 38 and 39 together along parallel lines or by suitably bonding such plies along such parallel lines to form such passageways. Passageways 40 through 42, and 45 through 49 are pressurized and deflated via suitable manifolds as described in the first embodiment. The passageways 40 through 42 located above the stagnation line 37--37 define the first set of inflatable passageways which is the upper extensible portion or region of the deicer pad, while passageways 45 through 49 define the second set of passageways which is the lower extensible portion or region of the deicer pad. Located between the upper and lower extensible portions is the intermediate non-stretchable or non-extensible portion or region of the deicer pad. The distance above and below the stagnation line 37--37 to the passageways 40 and 45 are equal and are void of inflatable passageways and is non-extensible or non-stretchable upon inflation of passageways 40 through 42 and 45 through 49. The respective inner surfaces of plies 38 and 39 may be napped as with short flexible fibers of uniform thickness to prevent complete closure of the passageways. The number of passageways above or beyond the stagnation line in each example may be varied and the number used in the examples above are only illustrative of the invention in a specific example.
The operation of the deicer pad as shown in FIG. 4 is substantially similar to the operation as described in the first embodiment with the cycling of the inflation and deflation of the passageways which distends and expands the upper and lower portions of the deicer pad effectively providing a clamshell effect in breaking up the ice on either side of the stagnation line 37--37 including that area or region to either immediate side of such stagnation line which covers the intermediate non-extensible or non-stretchable portion or region of the deicer pad.
It will be apparent that, although a specific embodiment and a modification thereof has been described, the invention is not limited to the specifically illustrated and described constructions since variations may be made without departing from the principles of the invention.
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A deicer pad for use on an airfoil wherein the airfoil has a leading edge and a stagnation line. The deicer pad is constructed to have an intermediate portion or region and two spaced apart portions or regions and with inflatable passageways only located on or within the two spaced apart portions. The pad is mounted on the airfoil so that the intermediate portion which is non-extensible or non-stretchable overlies the leading edge and the stagnation line of the airfoil. The stagnation line is generally parallel to the leading edge of the airfoil. The passageways in the two spaced apart portions of the deicer are inflatable either simultaneously or in seriatim order and effect the breaking up of the ice over the entire deicer. The inflatable passageways are the sole means for deicing.
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BACKGROUND OF THE INVENTION
The present invention relates to skylights and, more particularly, to a skylight system with a tubular light conduit connecting to a roof skylight device to a ceiling skylight device.
Roof skylights are a means to provide daylight into a room with limited amounts of available daylight. Usually, such rooms have no windows or one window. Townhouses or row houses in particular are faced with light limitations, except for end units, they only receive sun light from two directions. As the earth rotates about the sun and depending on which direction a house faces, a room may receive a lot or a little sunlight. To overcome the limited available sunlight coming into a room, skylights were invented.
The early skylights had metal frames and glass panes with wire mesh embedded in the panes for safety purposes. The skylight was mounted on a roof over a shaft leading from the roof to a ceiling. Generally, the shaft was covered with wood or plaster board. The problem is that the sunlight reflects off the shaft, which has been painted, some of the light is absorbed, particularly when the angle of the sunlight is low. Another problem is when a skylight and shaft are added after a house is built, the alignment of a skylight opening and a ceiling opening may be off.
Recent developments of skylights, including the patented art, use modern materials to create skylights. With the use of modern plastics, sunlight at any angle cap be reflected through a skylight shaft into a room and skylights can be bent to align a skylight shaft with a skylight opening and a ceiling opening.
A patent of interest to the present invention is U.S. Pat. No. 5,502,935, issued to Demmer. In the Demmer disclosure, a skylight, shown in FIG. 1 has a skylight module 12 and a ceiling mounted fixture module 16 connected by a flexible, tubular, light conveyance module 20. The flexible, tubular light conveyance module 20 has an inner wall portion 54, an outer wall portion 56, and a middle portion on an insulation material 58. The inner wall portion 54 is white to facilitate light reflection. Both the inner and outer wall portion 54 and 56, respectively, are made of a durable, flexible vinyl material. The middle portion 58 insulation is an injected foam, fiberglass or any other known, flexible insulating material.
For the purposes of the present invention, Demmer provided the flexible, tubular light conveyance module with a series of pleats 52 to facilitate bending into alignment with the skylight module 12 and the ceiling mounted fixture module 16. Module 20 can be reinforced with a wire spiral.
Demmer also discusses the use of flexible, tubular light conveyance modules 20 of circular, rectangular or other shape in cross-sections.
SUMMARY OF THE INVENTION
The present invention relates to a light and air conducting tube which connects between a skylight and a ceiling opening through an attic or like space between the roof and the ceiling of a house. The light and air conducting tube is somewhat flexible to allow bending of the tube to match the locations of a skylight and a ceiling opening should they not be aligned. At the same time the tube is firm enough to not collapse under its own weight. The inner surface of the light and air conducting tube has a highly reflective tube for greater light transmission. To further increase the amount of light transmitted, the tube has a square or rectangular cross-section, which increases the area approximately 27% more than a circle.
The construction of the light and air tube includes a reflective liner of a suitable plastic, a center insulation, such as bubble wrap, and an outer liner of aluminum foil. This construction provides good light transmission, insulation against cold and heat, and a good fire retardant radiant barrier.
The skylight has a dome covering the top opening, such dome is preferably white to further maximize the light transmitted to the interior of the building.
It is therefore and object of the present invention to provide a new and improved roof to ceiling skylight which may be easily manufactured as a reasonable cost.
Another object of the present invention is to provide a skylight assembly that has the flexibility to bend and conform in an attic space to align with both a skylight and a ceiling opening.
It is a further object of the invention to provide a light and air tube with a light reflective inner wall, an insulation center core, and a fire retardant outer wall.
Still a further object of the present invention is to provide a new and improved roof to ceiling skylight apparatus which eliminates the need for a customized construction of a light conveyance between a roof-mounted skylight and a ceiling-mounted translucent fixture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the outline of a roof and a partial ceiling connected by a light and air conducting tube where one end of the tube is connected to a skylight and at the other end to a ceiling translucent or transparent fixture.
FIG. 2 shows a partial cross-section of a light and air conducting tube of the invention.
FIG. 3 shows another embodiment of a cross-section of a light and air conducting tube of the invention.
DESCRIPTION OF THE INVENTION
Referring to the drawings, FIGS. 1 to 3 , there is shown the outline of a house or building roof 10 , having a skylight 12 , and a partial section of an interior ceiling 14 having an opening 16 covered by a light panel 18 , a light and air conducting tube 20 connects the skylight 12 to the ceiling light panel 18 . As can be seen, the skylight 12 and the ceiling light panel 18 are out of alignment. That is to say, they are not in vertical alignment therefore, the light and air conducting tube 20 is flexible in order to connect skylight 12 to ceiling light panel 18 . While the tube 20 is flexible, it is still firm enough to support its own weight.
It is shown in FIG. 1 , that the light and air conducting tube has a square or rectangular cross-section which among other things provides a larger light area than would a round or circular cross-section.
FIG. 2 shows a partial cross-section of a light and air conducting tube 20 . Having an interior liner 22 , a center insulation core 24 and an outside layer 26 . The interior liner has metallized polyester such as WMP-50 building facing material by Lamtech or similar materials made by Alpha Associates, Inc. such as VR-R which use a white polypropylene (PP) film with a metallized polyester film backing and fiberglass scrim tear stopper. Alternately, the reflective coating can also be achieved by using a silver sputter process on various flexible plastic films or specialty film such as 3M Silverlux or the newer High Reflective Mirror Films. The main concern is to achieve the highest degree of light reflectance at the most economical cost. Currently a hot-melt glue is used to laminate the reflective liner to the “top side” of the Astro-Foil bubble wrap. This “top side” can be sealed with a plastic cap or alternately finished with aluminum foil if extra strength or firmness is desired.
The center insulation core 24 is made of 3/16 single polyethylene air bubble material ( FIG. 1 ) or ⅜ polyethylene air bubble material ( FIG. 2 ). The air bubble provides insulation from hot and cold air convection. Currently our preferred material in production is the single bubble ( 3/16″) which is 0.1875 thick plus the WMP-50 reflective liner which is about 9 mils thick which with glue is about 0.200″ thick (200 mils)-or one fifth of an inch. The combination of all of these materials provides a very firm composite that is highly compact for shipping, flexible for installation and suitably rigid after fabricating and installing in place as a skylight tube. The double-bubble material might be preferred for larger skylight tubes to enhance firmness (rigidity) or where more insulation is needed to meet more extreme temperature conditions. Outside layer 26 has a plastic cap usually extruded from the same material as the air bubble chambers lined with a commercial grade aluminum foil for strength and durability. The aluminum foil is typically 99% pure AL and acts as a barrier against radiant heat gain or loss from the invented skylight tube. The plastic cap is a minimum part of the bubble-wrap insulation material, but normally comes with aluminum foil bonded to at least one side. Although the aluminum foil is optional, it is the preferred construction method because of its inexpensive fire retardant radiant barrier advantages.
The light reflective material can by made of virtually any high polished metal of metallized film or metallized fabric material. There are at least several commercially available which are already fire related and/or ASTM or UL listed, etc. Currently a commercial grade metallized film is used with a polypropylene scrim weave core for added strength and durability such as WMP-50 by Lamtech. The key is to have the reflective material attached (bonded or laminated, etc.) to a firm-yet flexible backing which is also code and fire rated for use as building material, such as the above mentioned Astro-Foil bubble wrap. The bubble foil core 24 can range in thickness from about ⅛″ to ¼″ thick (preferably 0.200″ thick) but should consist of a firmness able to hold up it's own weight when held out about 24″ in length or width. The suitable material should ideally insulate well and yet be flexible enough to be easily cut such as scissor trimmed for ease of installation. At the top and bottom it would be attached by staples or similar fastening means such as rivets, screws or tape. After installation, a quick hand or pole insertion would help unfold or open up any area(s) inside the tube such as around bends. The seam or seams could run where ever needed to accommodate standard and/or custom fit size runs. However, normally a seam would run parallel to the length of the tube for smaller tubes and for larger or longer tubes there may be more than one seam running either length wise or perhaps also two or more around the circumference of the tube to accommodate unique sizes. As mentioned before, the outside layer 26 of the tube is optional and can come with a reflective material as a further insulation barrier or may also come without it. The outside layer of reflective aluminum foil is being used in the current preferred embodiment.
In FIG. 3 , a double air bubble core is shown to increase the insulation quality of the core 24 ′.
While only one embodiment of the invention has been shown, it is understood that one skilled in the art may realize other embodiments. Therefore, one should consider the drawings, description and claims in their entirety.
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This invention relates to a flexible light conduit having two ends, one end mounted to an outdoor support such as a roof and at it's other end to a ceiling or other support inside a structure such as a house, garage, shed or other structure, said light conduit being of any shape in cross section, preferably square or rectangular and lined with any material or combination of materials for insulation, ornamentation and the like.
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FIELD OF THE INVENTION
[0001] This invention relates to a method of attaching an integrated circuit component to a substrate, and in particular to a method for attaching an integrated circuit (IC) component such as a memory chip or a RFID (radio-frequency identification device) to a smart card.
BACKGROUND OF THE INVENTION
[0002] There are an increasing number of applications in which it is desired to fix an IC component such as a memory chip, RFID chip or other form of IC component to a substrate, usually a relatively thin plastics substrate. Such applications include credit cards, debit cards, identity cards, stored value cards, security passes and the like. Such devices are generally known as “smart cards”. They are conventionally about the size of a credit card (i.e., no more than about 9 cm by 6 cm say), and preferably should not be significantly thicker than a conventional credit card so that a smart card can be kept with conventional credit cards and other such cards in a wallet or card holder without any inconvenience.
[0003] The IC component may have a varying degree of processing power ranging from a simple memory chip through to an IC chip capable of processing inputs. Typical functions of the IC component include data storage, data receiving, and data transmission. In all cases, however, the chip must be secured both physically and electrically to the card, which could be a paper-based card though is more normally formed of plastics. The IC component may be electrically connected to conductive tracks which are electroplated or screen-printed on the substrate. For optimum results there are a number of desired features to any chosen method for fabricating such a smart card. The resulting card should not be unduly thick, the fabrication process should not damage either the substrate or the IC component, and the fabrication process should be quick and preferably low-cost.
[0004] One known method of fixing an IC component to a substrate includes the use of wire bonding techniques as illustrated in FIG. 1 . Wire bonding is used where an IC component is electrically connected to a connection area on the substrate through a thermosonic wire bond. Referring to FIG. 1 an IC component such as a memory chip 6 is attached to a substrate 5 through adhesive bonding. A tape or passive layer 4 is laminated onto the metallized surface of the substrate 5 in order to build an electrical circuit pattern on the substrate. Gold wires 2 are then bonded to form electrical connections from active areas 3 on the memory chip 6 to exposed conductive areas of the substrate surface. After high-temperature (approx. 200° C.) thermosonic bonding of the gold wires 2 between the memory chip 6 and the substrate 5 , an epoxy material 1 is dispensed over the area defined by the memory chip 6 and the electrical connections to the substrate 5 in order to encapsulate the memory chip 6 and the connections in order to protect them from damage and degradation. The epoxy material is cured at 150° C. for about 30 minutes.
[0005] There are a number of disadvantages with this prior art method. The process cycle is quite long not least because only one input/output wire bond can be formed at one time and this increases the total processing time. The thickness of the resulting smart card is also relatively large, partly because of the height of the loops of gold wire 2 forming the connections which may be about 200 μm) and the use of the epoxy encapsulant further increases the thickness and total dimensions of the resulting smart card. The card may be at least 600 μm thick and may be as thick as about 760 μm.
[0006] Also known in the art is flip chip technology using either isotropic conductive adhesives (ICA) or anisotropic conductive adhesives (ACA). Such techniques are known as “flip chip” because the IC component is turned so that the conductive pads face the substrate as opposed to the technique shown in FIG. 1 in which the conductive areas 3 face away from the substrate. In both ICA and ACA techniques the IC component is fixed to the substrate by a conductive adhesive that provides both the physical and electrical connection.
[0007] FIG. 2 shows an example of a prior art ICA technique. An IC component such as a memory chip 7 is electrically connected to the substrate 12 through the use of an isotropic conductive adhesive 9 . The ICA 9 is screen-printed at the connection regions of the substrate 12 , and the memory chip 7 is then mounted and bonded with the bond pads 8 of the chip 7 aligned with contact areas 10 on the substrate. The ICA 9 is then pre-cured at 150° C. for 1 minute until the memory chip 7 will at least hold in a stable position on the substrate 12 . Subsequently an epoxy underfill 11 is filled into the space between the memory chip 7 and the substrate 12 by capillary action to serve as a stable mechanical protective layer. The memory chip 7 is bonded to the substrate 12 with a mounting time of 6±3 seconds and at a pressure of 4±3N. The bonded sample is then post-heated in an oven at 150° C. or below for 2 minutes or above until the final mechanical and electrical properties are achieved. This method, however, includes a number of processing steps including the screen printing of the ICA on the substrate, mounting of the memory chip, pre-curing of the ICA, and curing of the epoxy underfill. The method does reduce the total thickness of the finished smart card to about 500 μm, but the total processing time exceeds 1 hour.
[0008] FIG. 3 shows a prior art method using an anisotropic conductive film (ACF). ACF is an epoxy matrix 17 filled with conductive particles 15 which may be gold, nickel, or polymer beads coated with gold and/or nickel. An IC component such as a memory chip 13 is attached to a contact area on a substrate 18 . Electrical connections are formed by the entrapment of electrically conductive particles 15 between the bond pads or bumps 14 formed on the memory chip 13 , and the electrodes 16 formed on the substrate 18 . The ACF epoxy matrix 17 will act as a protective layer.
[0009] The use of ACF has the advantage that it forms the electrical connection path and provides mechanical stability in a single process step. The interconnections are formed when the conductive particles 15 are compressed and deformed in the area between the active areas 14 on the chip 17 , and the electrodes 16 on the substrate. The thermal loading is about 200° C. for about 10 s, and with the ACF being compressed to about 20 μm or less both the thickness (the total thickness may be about 450 μm) and the processing time may be reduced. The disadvantage of this method, however, is that it requires a high pressure loading up to 100 Mpa or above to form the electrical connections.
SUMMARY OF THE INVENTION
[0010] According to the present invention there is provided a method of attaching an integrated circuit component to a substrate. The method comprises dispensing a controlled amount of photo-activatable anisotropic conductive adhesive (ACA) at a desired location on said substrate, exposing said dispensed ACA to electromagnetic radiation source to initiate a chemical reaction in said ACA, aligning said component with said substrate such that a bond pad on said component faces said dispensed ACA, bonding said component to said substrate under a low pressure loading, and heating said bonded component and substrate.
[0011] Preferably the electromagnetic radiation is UV radiation, for example the radiation may be at a wavelength of between about 250 nm to about 400 nm. The electromagnetic radiation may have an intensity of about 140 mW/cm 2 ±about 60 mW/cm 2 (i.e., about 80 mW/cm 2 to about 200 mW/cm 2 ).
[0012] Preferably the low pressure loading is about 4N±about 3N and is held for a loading time of about 6 seconds±about 3 seconds. The heating may comprise heating in an oven at a temperature of less than about 150° C., and the heating may be carried out for at least about 2 minutes.
[0013] The ACA may comprise conductive particles within an epoxy matrix and wherein said conductive particles have a diameter of about 6 μm±about 2 μm.
[0014] The method may be applied to the manufacture of a smart card, for example where the integrated circuit is a memory chip and the substrate comprises an antenna. In such an embodiment the memory chip has a length and width both of which are less than about 1.5 mm and a wafer thickness of about 150 μm±about 50 μm, and the memory chip is formed with bond pads having a thickness of about 18 μm±about 5 μm. The substrate may be formed with conductive tracks and wherein the bond pads of said memory chip are connected to connection points of the conductive tracks. The conductive tracks may be formed by electroplating copper or aluminium onto said substrate, or by screen printing with a silver paste polymer, and may form the antenna of an RFID smart card.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:—
[0016] FIG. 1 shows in cross-section a smart card formed by a conventional method using wire bonding,
[0017] FIG. 2 shows in cross-section a smart card formed by a conventional method using isotropic conductive adhesive,
[0018] FIG. 3 shows in cross-section a smart card formed by a conventional method using an anisotropic conductive film,
[0019] FIG. 4 shows the dispensing of UV activated ACA in an embodiment of the invention,
[0020] FIG. 5 shows an enlarged view of the UV activated ACA in an embodiment of the invention, and
[0021] FIG. 6 is a cross-section through a smart card formed according to an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The present invention, at least in its preferred forms, provides a method of fabricating a smart card in which the IC component (e.g., a memory chip) is attached to the substrate (e.g., a chip carrier) using UV-activated ACA. UV-activated ACAs comprise conductive particles in an epoxy resin with the addition of a UV photo-initiator. The technique is similar to the above-described prior art method using a heat-cured ACF as described with reference to FIG. 3 , at least to the extent that metal or metal-coated polymer particles in the ACA will form the electrical connection between the memory chip and the connections on the substrate. However, the method of the present invention uses UV-activated ACAs which need to be exposed to UV (or a light spectrum within a certain wavelength) for a few seconds to initiate and activate the necessary chemical reaction. Although this UV-activation implies an additional processing step, the advantage of using UV-activated ACAs is that the method allows the use of low-cost materials for the substrate such as PET and PVC, and the use of copper and aluminium and other less noble metals, since the processing parameters such as temperature and pressure are less severe and therefore less demanding on the choice of materials.
[0023] In FIGS. 4 to 6 an embodiment of the invention will be described in which an IC component in the form of a chip 25 is to be fixed to a substrate 20 (70 mm by 80 mm) as part of a contactless RFID smart card. A typical size for the chip may have a length and width less than about 1 mm, and a thickness of about 150 μm±about 50 μm. In such an embodiment the chip 25 is electrically connected to windings that extend around the edges of the rectangular substrate 20 and form an antenna 19 ( FIG. 4 ). The antenna windings may, however, be square, rectangular or circular depending upon the desired application. The antenna windings are preferably formed of less noble metals than gold and silver, such as copper, aluminium or silver paste. The substrate is preferably formed from low cost plastics materials such as PVC, PET and other low T g materials which are cheaper than popularly used fiber glass (FR 4 ) or polyimide (PI) though of course such more expensive materials could be used if desired.
[0024] As can be seen from FIG. 4 , an amount of UV-activated ACA 21 is provided at one end of the substrate 20 in the region of the windings 19 and this will be described in more detail with reference to the enlarged view of FIG. 5 . An example of a suitable form of UV-activated ACA is DELO ACAbond UV-activated ACA. This is an adhesive comprising conductive particles with the size of the particles being around 6.5 μm and the density of particles being around 1200/mm 2 .
[0025] Referring to FIG. 5 the ACA 21 is dispensed so as to contact connections 23 , 24 of the antenna windings and also to cover individual windings shown by reference number 19 in FIG. 5 . The ACA 21 should be provided at this connection part of the substrate in order to form the necessary connections between the chip 25 and the antenna 19 . The amount of ACA used and the spot size is controlled by a dispenser. The amount of ACA and the spot size needed will depend on the pitch between the connections 23 , 24 . Sufficient ACA should be provided to make the necessary connections, but too much ACA should be avoided as it may contaminate the bond head which is used to hold the chip 25 . The ACA is exposed to light with a spectrum of from about 250 nm to about 400 nm for a short period of time (e.g., about 5 s±about 3 s) at an intensity of about 140 mW/cm 2 ±about 60 mW/cm 2 to activate the photo-initiators in the ACA.
[0026] The substrate 20 is then placed on the chuck table of a flip chip bonder, and a chip 25 (typically with length and width dimensions no greater than about 1.5 mm, a wafer thickness of about 150 μm±about 50 μm and a bond pad thickness of about 18 μm±about 5 μm) is placed on the bond head and is aligned such that connection bond pads 26 formed on the chip 25 match connections 23 , 24 on the substrate 20 . The chip 25 is then mounted and bonded at a low bonding pressure of less than about ION, preferably about 4N±about 3N, for a loading time of about 6 s±about 3 s, and the UV-activated ACA is then post-heated at less than about 150° C. for at least about 2 minutes until the desired mechanical and electrical properties are achieved. A smart card with a thickness of about 390 μm can be achieved in this way.
[0027] FIG. 6 shows the cross-section of the connection between the chip 25 and the substrate 20 in more detail. The electrical connection path is established through the contact of conductive particles 27 present in the ACA between the bond pads 26 on the chip 25 and the connections 23 , 24 of the antenna 19 . The conductive particles may have a diameter of about 6 μm±about 2 μm. The epoxy material 34 provides mechanical strength and stability to the connection between the chip 25 and the substrate 20 .
[0028] A significant advantage of the present invention, at least in its preferred forms, is that by the use of UV-activated ACA both low bonding pressures and low process temperatures are employed. This enables the method to be used with cheaper materials for the substrate and for the electrical connections and conductive tracks as they do not have to withstand high temperatures and/or pressures as in the prior art.
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An integrated circuit component is attached to a substrate by dispensing a controlled amount of photo-activatable anisotropic conductive adhesive (ACA) at a desired location on the substrate, exposing the dispensed ACA to an electromagnetic radiation source to initiate a chemical reaction in the ACA, aligning the component with the substrate such that a bond pad on the component faces the dispensed ACA, bonding the component to the substrate under a low pressure loading, and heating the bonded component and substrate.
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This application claims the benefit of U.S. Provisional Application No. 60/107,371, filed Nov. 6, 1998.
BACKGROUND OF THE INVENTION
This invention relates in general to a support platform for a computer keyboard or the like and, more particularly, to a tilt control or pitch control mechanism for a keyboard support platform. The tilt control mechanism of the present invention permits the selective adjustment of the pitch or tilt of the support platform to allow the user to set the work angle of the keyboard.
The keyboard support platform construction is of the type generally shown in McConnell, U.S. Pat. No. 5,037,054 and U.S. Pat. No. 5,145,136, or Smeenge et al., U.S. Pat. No. 4,616,798. The aforesaid McConnell and Smeenge patents are incorporated herein by reference. Typically, a keyboard support platform is attached by parallel and/or non-parallel pivotal linkage arms to a slidable plate. The slidable plate, in turn, is mounted in a slide on the underside of a desk or other work surface. The slide permits the keyboard support platform and linkage to move between a storage position or retracted position to an extended or use position. The conventional pivotal linkage arms further permit the keyboard support platform to be adjusted to a useful operational work height.
The conventional keyboard support platform assemblies, however, are limited in the degree of keyboard tilt. That is, known keyboard platform assemblies limit the operational work angle of the keyboard and, therefore, do not ergonomically comply with the requirements of all users. Because conventional keyboard support platform assemblies are so limited, keyboard users have suffered from various debilitating medical conditions. As an example, it has been shown that without the proper work angle setting of the keyboard, users who perform considerable data entry on the keyboard have suffered from Carpal Tunnel Syndrome which is a medical disorder of the hand that creates numbness and pain in the fingers. Consequently, there is a need for an improved keyboard support platform assembly which provides not only adjustable work height of the keyboard but also improved adjustment of the tilt or work angle of the keyboard to prevent such debilitating medical conditions.
SUMMARY OF THE INVENTION
The present invention recognizes and provides a solution to the aforementioned problems associated with the known keyboard support platform assemblies. Accordingly, it is an object of the present invention to provide an improved adjustable support mechanism for a keyboard support platform. It is a further object to provide an adjustable tilt control mechanism which permits the user to set the pitch or angle of the keyboard support platform.
Briefly, in summary, the present invention comprises a tilt control mechanism for a keyboard support platform. The keyboard support platform is of the type that includes a linkage for connecting the platform to a work surface. The linkage further includes linkage arms which pivotally connect the keyboard support platform to the work surface. The tilt control mechanism comprises a keyboard support platform bracket having a tilt pivot axis connection to the linkage arms, and a tilt adjustment actuator arm pivotally attached at a fulcrum point at one end to the pivot axis connection. Connected between the actuator arm and support platform is a pawl and ratchet. The pawl and ratchet connection define distinct length actuator arm connections between the fulcrum point and the support platform to thereby control the tilt or pitch of the platform.
The full range of objects, aspects and advantages of the invention are only appreciated by a full reading of this specification and a full understanding of the invention. Therefore, to complete this specification, a detailed description of the invention and the preferred embodiment follows, after a brief description of the drawing.
BRIEF DESCRIPTION OF THE DRAWING
The preferred embodiment of the invention will be described in relation to the accompanying drawing. In the drawing, the following figures have the following general nature:
FIG. 1 is a plan view of the tilt control mechanism of the invention as incorporated with a keyboard support platform;
FIG. 2 is an end elevation view of a keyboard support platform;
FIG. 3 is an exploded plan view of the component parts of the tilt adjustment mechanism of the invention of FIG. 1;
FIG. 4 is a side elevation view of the platform of FIG. 2;
FIG. 5 is a plan view of a keyboard support platform with a partial cut-away view of an alternative embodiment of the tilt control mechanism of the invention;
FIG. 6 is a side elevation view of a keyboard support platform of FIG. 5;
FIG. 7 is an exploded plan view of the component parts of the tilt adjustment mechanism of the invention of FIG. 5;
FIG. 8 is a side elevation view of the tilt adjustment mechanism of FIG. 7; and
FIG. 9 is a plan view of the tilt adjustment mechanism of FIG. 7 .
In the accompanying drawing, like reference numerals are used throughout the various figures for identical structures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the figures, the keyboard support platform, such as platform 10 , is typically attached to linkage arms 4 by means of a first pivot shaft 12 and a second pivot shaft 14 . The linkage arms are conventionally connected to a slide bracket assembly 6 which, in turn, is attached to the work surface. Typically, the bracket assembly 6 supports the weight of the keyboard platform and permits sliding movement of the keyboard platform from a retracted position to an extended position. The platform 10 may be pivoted about the shaft 12 in order to adjust the tilt or pitch of the platform. The shaft 14 fits through an arcuate slot 16 to accommodate the change in pitch of the platform 10 .
The subject matter of the present invention relates to a mechanism which permits adjustment of tilt about the shaft 12 by movement of the platform along the range defined by the arcuate slot 16 . Referring to FIGS. 1-4, in a preferred embodiment, the mechanism includes an actuator arm block 20 which is fitted over the shaft 14 and thus remains fixed in position relative to the axis defined by the shaft 14 . The actuator arm 22 connects the actuator arm block 20 to the platform 10 . As more fully discussed below, by adjusting the length of the connection defined by the actuator arm 22 between block 20 and the platform 10 , one is able to adjust the tilt of the platform 10 to any of a number of incremental positions. Thus, the actuator arm 22 and the mechanism for connecting and adjusting the length of the connection of that arm 22 to the platform 10 , herein described as a pawl and ratchet mechanism, relates specifically to the subject matter of the invention.
The actuator arm 22 is connected to the actuator arm block 20 by means of a pivot or pin 24 . Pivotally connected to the actuator arm 22 by a pin 28 is a pawl which is further defined as a roll pin arm 26 and a roll pin 30 . The roll pin arm 26 receives the roll pin 30 which fits within opening 31 defined in the roll pin arm 26 . As illustrated in FIG. 1, the roll pin 30 operatively engages with a ratchet which is defined as a number of spaced detents 32 further defined in a detent slot 34 in the platform 10 . A spring 35 connected between the roll pin arm 26 and the end of the actuator arm 22 biases the roll pin arm 26 toward the actuator arm 22 . The spring 35 also causes the roll pin 30 to be engaged with a detent 32 and remain engaged therewith.
Depending upon the detent 32 , which is engaged by the pin 30 , one is able to control the pitch or tilt of the platform 10 inasmuch as one thereby adjusts the length of the actuator arm 22 between pin 24 and the detent 32 engagement with the platform 10 . This length adjustment of the actuator arm 22 causes the tilt or pitch of the platform 10 to vary. As preferred, the detents 32 are spaced to provide 5° increments in tilt of the platform 10 .
As a secondary or failsafe alignment feature of the invention, the actuator arm 22 includes a pin or rivet 36 which projects from the actuator arm 22 into an inclined slot 38 in the platform 10 . The configuration of the slot 38 as well as the detent slot 34 provides accommodation for variance of the pitch or tilt of the platform as the arm 22 is pivoted clockwise or counterclockwise about the pin or rivet 24 .
A release arm 40 is pivotally attached to the actuator arm 22 by means of a pin 42 . The release arm 40 includes an inclined cam surface 44 and a release projection 46 which cooperates with a release tab 48 in the platform 10 , described in greater detail below. The distal end of the actuator arm 22 , the end opposite the pivot 24 , includes a crimp or projecting lip 50 which cooperates with the release arm 40 .
In operation, as depicted in FIG. 1, the platform 10 is raised to its highest or most clockwise tilt in the range of tilt by pulling upwardly on the platform 10 . By pulling upwardly on the platform, the release arm 40 is caused to pivot clockwise about the pin 42 whereby the inclined surface or cam 44 will engage against the roll pin arm 26 causing the arm 26 to pivot clockwise about the pin 28 against the biasing force of spring 35 . The roll pin arm 26 pivoting about the pin 28 in a clockwise sense releases the roll pin 30 from detent 32 . By pulling on the platform to move it in a clockwise direction, the release arm 40 is caused to engage the release tab 48 , and more particularly, the projection 46 engages the tab 48 as the arm 22 is pivoted toward the last detent position. This causes the arm 40 to be engaged with the crimp 50 thereby holding the assembly in a fixed locked open position with the roll pin 30 released from the slot 34 . When in this position, the entire platform 10 may be lowered to its low end of the tilt range. When so lowered to this low end, the release arm 40 is released or disengaged by the crimp 50 . The pin 30 may then be biased into one of the detent slots or openings 32 .
To summarize, the, condition of the platform 10 , as depicted in FIG. 1, is that of being almost at the top of the range of tilt and thus the length of the actuator arm 22 between pin 24 and detent 32 is at its shortest length. In contrast, at the longest length of the distance between the pin 24 and the roll pin 30 , the platform 10 is at its lowest end of the tilt range with intermediate steps represented by detents 32 therebetween. In practice, the platform 10 is raised to its uppermost tilt range by releasing the engagement of the roll pin 30 and the detents 32 as previously described. It is then moved to its lowest tilt range where upon the release arm 40 is disengaged causing the detent roll pin 30 to engage with the first detent 32 . Thereafter, by manually raising the platform 10 , the platform tilt may be adjusted from one detent to the next as the pin 30 moves from left to right in FIG. 1 .
Referring to FIGS. 5-9, an alternative preferred embodiment of the invention in depicted. In this embodiment, an actuator arm block 60 is fitted over the shaft 14 . As above, the actuator arm block 60 is connected to the actuator arm 22 through the means of the pin 24 . The pin 24 permits rotation of the actuator arm 22 relative to the actuator arm block 60 . Pivotally connected to the actuator arm 22 by a rivet 64 is the pawl. In a preferred embodiment, the pawl defines an actuator hook 62 . The actuator hook 62 receives a rivet 66 which, as above, operatively engages with the ratchet. That is, the rivet 66 fits into any one of the number of spaced detents 32 defined in the detent slot 34 in the platform 10 . The actuator hook 62 further defines an opening 68 for receiving a lock spring 70 . The lock spring 70 connects the actuator hook 62 to an opening 71 in an actuator hook lock 72 . The actuator hook lock 72 is pivotally connected to the actuator arm by a rivet 74 . The actuator hook lock 72 defines a cam surface 73 that contacts and engages the actuator hook 62 . Pivotally connected to the end of the actuator arm 22 through the use of a rivet 74 A is a lock-out handle 76 .
In operation to change the pitch of the keyboard platform, the lock-out handle 76 is manually rotated about rivet 74 A until the handle 76 contacts the actuator hook lock 72 , as depicted in FIG. 9 . The actuator hook lock 72 , in turn, pivots about rivet 74 causing the cam surface 73 of the hook lock 72 to contact the actuator hook 62 forcing the actuator hook 62 to rotate about the rivet 64 and thus lifting the rivet 66 away from the detent 32 . Once lifted away from the detent 32 , the rivet 66 may be incrementally positioned within an adjacent detent 32 , thereby effectively changing the tilt or pitch of the platform. The lock spring 70 holds the actuator hook 62 in operative engagement with the cam surface of the hook lock 72 .
Again, a failsafe alignment feature is incorporated which includes the pin 36 that projects from the actuator arm 22 into the inclined slot 38 in the platform 10 . As above, the configuration of the slot 38 accommodates the variance of the pitch or tilt of the platform as the arm 22 is pivoted clockwise or counterclockwise about the pin 24 .
The preferred embodiments of the invention are now described as to enable a person of ordinary skill in the art to make and use the same. Variations of the preferred embodiment are possible without being outside the scope of the present invention. Therefore, to particularly point out and distinctly claim the subject matter regarded as the invention, the following claims conclude the specification.
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There is disclosed a tilt control mechanism for a keyboard support platform. The keyboard support platform is of the type that includes linkage for connecting the platform to a work surface. The linkage further includes linkage arms that pivotally connect the keyboard support platform to the work surface. The tilt control mechanism comprises a tilt adjustment actuator arm and a pawl and ratchet connection between the actuator arm and the support platform. The pawl and ratchet provide a series of separate detent positions which define distinct length actuator arm connections between a fulcrum point and the support platform to thereby control the tilt of the platform.
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BACKGROUND OF THE INVENTION
Residential housing and much commercial building has in the past been made in the United States and in other countries with wooden supporting structures, most of it in the form of elongated beams of standard sizes in inches, such as 2×2, 2×4, 2×6, 2×8, 2×10, 2×12, 4×4, 4×6, 4×8, 4×10, and 4×12. Due to the decreasing supplies of wood and the corresponding increasing costs of wooden beams, attempts have been made to employ steel beams in place of wooden beams for this type of construction. Typical of such attempts are the metal beams shown in U.S. Pat. Nos. 4,001,993; 4,058,951; 4,130,970; 4,793,113; 4,809,476; 5,157,883; and 5,222,335. While these inventions are suitable for many purposes, they are complex and costly and leave much to be desired.
It is an object of this invention to provide a novel metal wall stud. It is another object of this invention to provide a novel metal wall stud in the form of a steel channel beam with tabs at its ends to provide easy attachment to horizontal wooden and metal plates. Still other objects will become apparent from the more detailed description which follows.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a metal construction wall stud in the form of a channel beam having in transverse cross-section a rectangular U-shape including a flat bottom wall, two parallel side walls attached perpendicular to the bottom wall, and two short flat lips attached perpendicular to the side walls and facing inwardly toward each other. The bottom and side walls are hole-punched with spaced identical patterns of small holes adapted to receive nails or screws therethrough. The bottom wall contains spaced large holes to receive plumbing or electric wiring therethrough. At the ends of the bottom wall and the side walls are tabs with small holes for nails or screws, the tabs being foldable at right angles to the walls from which they extend.
In specific and preferred embodiments there are two side-by-side tabs, normally bendable in opposed directions, extending from each end of the bottom wall, and there is one tab extending from each end of each side wall for connection to plate, the side wall tab having a length equal to 1-3 times the transverse width of the side wall. One side wall tab is transversely reduced so that two studs with their bottoms opposed and sides nestingly positioned provide a telescopic adjustment therefor.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of a first embodiment of the wall stud of this invention mounted between a wooden top plate and a wooden bottom plate;
FIG. 2 is a transverse cross-section taken at 2--2 of FIG. 1;
FIG. 3 is a perspective partial view of a second embodiment of the wall stud of this invention;
FIG. 4 is a perspective partial view of a third embodiment of the wall stud of this invention;
FIG. 5 is a top plan view of the blank from which the wall stud of this invention is made;
FIG. 6 is a schematic cross-section of two wall studs of this invention joined to make a sliding telescopic wall stud;
FIG. 7 is a perspective view of the connection of the wall stud of this invention to a wooden bottom plate; and
FIG. 8 is a perspective view of two wall studs of this invention to frame a window.
DETAILED DESCRIPTION OF THE INVENTION
The features of this invention are best understood by reference to the attached drawings.
The invention relates to a metal channel beam used to replace a wooden stud beam, normally a 2×4 beam, and other similar common wooden beams, e.g., 2×6, 2×8, 2×10, 2×12, 4×4 and the like. The novel metal beam 10 is shown in cross-section in FIG. 2 to have a bottom wall 16, two side walls 17, and two short lips 18. Side walls 17 are perpendicular to bottom wall 16 and are positioned at the longitudinal edges of bottom wall 16 so as to form a channel. Lips 18 are perpendicular to side walls 17 with one longitudinal edge of lip 18 attached to the remaining longitudinal edge of side wall 17. These walls 16 and 17 and lips 18 form the outline of a rectangle exactly the same size as the wooden beam it is meant to replace. Thus for a replacement for a 2×4 wooden beam, side walls are 2 inches nominally (actually 1.875-1.5 inches) and bottom wall 16 is 4 inches nominally (actually 3.75-3.5 inches). Lip 18 may vary in length, but should remain short, e.g., 0.05-0.15 inch. The metal stock from which the wall stud is made may be any metal, but for availability and cost purposes should be steel, having a thickness of 14-26 gauge, although for special purposes may be lighter or heavier gauge. The wall stud may be made in a variety of lengths, i.e., from one transverse end 19 to the other transverse end 19, in the same manner as wooden beams. Such lengths might generally include 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 feet. The longer lengths would be made of heavier gauge, e.g., 14-20, while the shorter lengths might be made of lighter gauge, e.g., 22-26. There are needs for shorter lengths for specialty purposes, as will be discussed below in connection with FIG. 8.
The wall stud of this invention is preferably pre-punched with two types of holes, 13 and 14, so as to make the stud more convenient to use than other metal studs known today. Small holes 13 are assembled in a patterned group 27 and identical groups 27 are spaced longitudinally along the length of stud 10. The pattern of holes 13 is identical and the orientation of the pattern is identical for every group 27 on the stud. This identicalness permits horizontal beams to be attached to vertical beams (see FIG. 8), and the horizontal beams will be level, if the vertical beams have been made plumb. The exact spacing and location of small holes 13 in each pattern is not critical so long as each pattern is identical so as to be aligned with other holes in other beams or tabs. Spacing between adjacent groups 27 may be selected as desired, although it is preferred to be about 3-6 inches, most desirably about 4 inches.
Large holes 14 are expected to be used for guiding and supporting plumbing lines and electric lines. Holes 14 are expected to be about 1-11/2 inch in diameter, preferably about 11/4 inch. The spacing between adjacent holes 14 is also not critical and preferably is about 2 feet. A preferred arrangement is shown in FIG. 1 with the first hole spacing 36 at each end of stud 10 being about 1 foot from the end 19 and all remaining spacings 31 being about 2 feet.
At each end of each wall 16 and 17 there are tabs 15 of various sizes and arrangements that are used for attaching stud 10 to other construction pieces. For example, in FIG. 1 tabs 15 provide integral means for attaching stud 10 to top plate 11 and the bottom plate 12. In this embodiment, the end of side wall tabs 15 should be spaced slightly above the lower surface of plate 12. If plates 11 and 12 are wooden, tabs 15 can be fastened to plates 11 and 12 by nails through small nail holes in the tabs 15. Screws can, of course, be used if desired. If plates 11 and 12 are also metal, the attachment of tabs 15 thereto can be by self-tapping screws, rivets, nuts and bolts, and the like. Nails used for this purpose are generally of the 8-16 penny size. Tabs 15 may take various sizes and arrangements. As may be seen in FIG. 1 side wall tabs 15 at the transverse ends of stud 10 include a single tab at each end of side wall 17, and double, side-by-side tabs at each end of bottom wall 16. The double tabs 15 are bent oppositely and at right angles to wall 16 and fastened to the appropriate plate 11 or 12. Such connection provides lateral stabilization with a positive connection to both sides of the bottom wall 16. Load bearing capability is also provided assuming the gauge is 20 gauge or thicker. Tabs 15 at the ends of side walls 17 are fastened with nails or screws to the short sides of plates 11 or 12. These tabs eliminate the need to toe-nail studs to plates or provide other connection straps or angles, as was necessary in the prior art when studs and plates were both wooden.
FIGS. 3 and 4 show alternate embodiments for tabs 15 at the ends of side walls 17. In these drawings the top plate 11 comprises two wooden beams 11. In FIG. 3 the single side wall tab 15 of FIG. 1 has been replaced by a double length tab 32 with nail holes 13 for each of the wooden beams 11. Also each end of the stud of FIG. 3 may be the same, so that the double length tab 32 is bent at the bottom edge of plate 12 to extend beneath plate 12 to dispose its free end portion 32' below the lower surface of bottom plate 12. In FIG. 4 the double length 32 of FIG. 3 has been replaced by a triple length tab 33 with its free end portion 33' bent over the top surface of the top beam 11. These constructions provide for greater uplift capability to the stud. It is to be noted that the end of tabs 15 are slightly spaced upwardly from the lower surface of plate 12 so that the studs 10 do not engage the concrete slab which is typical. If such tabs 15 did engage the concrete slab, as for example in the embodiment shown in FIG. 3, all the metal studs may require a grounding wire interconnecting all studs to ground. It can be seen that these and other arrangements may be desired for special situations.
FIGS. 5 and 6 show additional aspects in the features of stud 10 which may be beneficially employed. Two studs 10 of this invention can be combined, as shown in FIG. 6, to produce a telescopically extendable stud beam. The two studs 10A and 10B can be placed together as in FIG. 6 and they will slide lengthwise relative to each other, and in that way can be considered a telescopically extendable stud. Each stud 10A and 10B has one side wall 17 totally within the side wall 17' of the other stud.
In order for two beams to be combined as in FIG. 6 it is preferable that the beams be made in accord with the blank for the stud shown in FIG. 5. A flat sheet of steel is cut and punched with holes to form the blank of FIG. 5. Solid lines represent cut edges and broken lines represent fold lines which generally are not visible and are not physically different than the untouched areas between fold lines. In order to transform the blank of FIG. 5 to the stud beam of FIGS. 1-2 the sheet is folded along lines 20 and 21 to produce an elongated generally open channel having inwardly directed lips 18 extending substantially parallel to bottom wall 16. Tabs 15, 15L and 15R can be bent along line 19 to conform to the wooden plate 11 or 12 or which stud beam 10 is to be attached by way of nail holes 13. Tabs 15 need not be shaped with cut off corners (as shown in solid lines) but may be curved (as shown in dotted lines 29) or otherwise shaped, e.g. square with rounded corners, or the like.
It is preferred, when making studs 10 to be useful in telescopic combination (as in FIG. 6) to modify the tabs attached to side walls 17. One of those side walls should be made slightly narrower transversely than the other. In FIG. 5, side wall 17L has a width 38L while side wall 17R has a width 38R. The width 38L is slightly less than the width 38R by the amount shown approximately at 26, i.e., to accommodate about twice the thickness of the metal. When two studs 10A and 10B are to be used telescopically, as shown in FIG. 6, it is preferable that studs 10A and 10B be made as shown in FIG. 5 with side wall 17L slightly narrower than side wall 17R so that the stud 10A with narrower wall 17L will nest within and be juxtaposed to another stud 10B wider wall 17R and stud 10A with wider wall 17R being juxtaposed to stud 10B narrower wall 17L. In other words between lip 18 and bottom wall 16 of stud 10B is disposed bottom 16 and lip 18 of stud 10A with respective walls 17R and 17L being slidingly juxtaposed. Likewise, side wall 17R of stud 10A is slidingly juxtaposed with wall 17L of stud 10B.
FIGS. 7 and 8 show the way in which studs 10 and their tabs are attached to wooden beams and to horizontal stud beams. In FIG. 7 there is shown the normal connection of stud 10 to bottom plate 12. Stud 10 is placed vertically with transverse end 19 resting on the top of plate 12 and side wall tabs 34 extending downwardly from side walls 17 on each side straddling wooden plate 12 permitting nails to be driven horizontally through the small holes into beam 12. The central side-by-side tabs 35 extending downwardly from bottom wall 16 are bent at right angles so as to lie flat against the top surface of beam 12 and can be nailed down there. Both tabs 35 can be bent, if required, in the same direction or each in opposite directions, to provide lateral stabilization and a positive connection on both sides of bottom 16 of stud 10, as shown in FIG. 7. It is also to be noted that preferably tab 34 is shorter than the thickness of plate 12 by a small amount 37. This is preferred to be sure that beam 10 can be put in place without the necessity of filing the lower edge of tab 34 if that tab should be too long, and, as aforesaid, would not require grounding of the metal stud.
In FIG. 8 there is shown the same connection as in FIG. 7 with the addition of a horizontal metal beam member 28, which may be used as a part of the framing for a window or the like. In this instance there is used a metal stud beam of exactly the same features as those shown in stud 10 of FIGS. 1-2 except that the metal stud beam 28 is shorter than the usual 8-12 foot lengths. Shorter beams can be made to lengths that will be used for window framing, e.g., in multiples of the horizontal distance between adjacent vertical studs, e.g., multiples of 16-inch spacings. Attachments of horizontal beam 28 to vertical stud 10 are made through tabs 39 and 40 on the end of horizontal beam 28 and groups 27 of small pre-punched holes, as shown in side walls 17 of FIG. 7. It may be seen that patterns of small holes in groups 27 can be standardized with hole patterns in tabs 39 so that there will be alignment of holes to receive a connecting screw or bolt-and-nut. With spacings of groups 27 every 4 inches, it is likely that a window frame support can be made of horizontal stud beam 28 which would automatically be level by attachment of beam 28 at each end to the comparable group 27 of small holes on two horizontally spaced studs 10. Tabs 40, similar to tabs 35 in FIG. 7 can be included as desired to help secure beam 28 to beam 10, and can either be both turned upwardly as shown or reversed 180° to lie below the bottom 41 of beam 28. Suitable self-tapping screws can be used to connect tabs 40 to the bottom 16 of stud 10.
As can be determined from the above description the metal stud of the present invention provides a load bearing capability when fabricated from 14-20 gauge sheet steel, has lateral stabilization by providing positive connection by the integral split tabs bent in opposed directions and connected to the plate, integral side wall tabs connected to the sides of the plate or plates and/or bent over (under) the plate or plates and connected thereto to provide enhanced uplift loads and eliminating the need to use separate hurricane clips and metal plates and the like, and providing telescopic capability in using two of the U-shaped studs in a nesting and sliding relationship forming a box beam configuration.
Comparing the uplift loads of various nail sizes useable on the steel stud (two nails in each side tab) of this invention with a conventional Southern yellow pine stud being end nailed to a plate illustrates the enhanced utility of this invention:
______________________________________ conventional steel stud______________________________________4-8d nails 164# 640#4-10d nails 184# 722#4-16d nails 200# 928#______________________________________
of course, when the tabs are extended to connect to the second top plate and bent under and connected to the bottom plate four more nails are used at the top (and bottom) tab and the uplift load is accordingly at least doubled. When the upper tab is also extended and bent over the top most plate of a dual upper plate, the uplift load is greatly enhanced approaching the shear capacity of the metal stud or the breaking of the wood plate.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A metal wall stud in the shape of an elongated open channel having pre-punched nail or screw holes and pre-punched passageways for electrical or plumbing facilities. Integral tabs extending beyond the ends of stud walls are foldable to provide connections to wooden plates or metal wall stud purlins in the construction framing. Split tabs integral with the bottom wall of the channel provide lateral stabilization, greater uplift loads, and the capability of being load bearing. A pair of studs have nesting capability to provide telescopic adjustability for walls in a vaulted ceiling room.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 11/388,366, filed Mar. 24, 2006, which is incorporated by reference as if fully set forth.
FIELD OF THE INVENTION
The present invention refers to a thermoplastic element for the protection against corrosion in the thermofused splicing of a thermoplastic tube to a thermoplastic connection.
More particularly, the present invention refers to a corrosion-inhibiting thermoplastic element at a thermofused splice of a thermoplastic tube consisting of an intermediate metal layer placed between two thermoplastic layers, with a thermoplastic connection.
BACKGROUND
At present, joints between thermoplastic tubes and connections are performed by means of thermofusion joining, whereby during a few seconds tube and connection are subject to a temperature in the range of from 260 to 270° C. and after the elapsing of the heating time both elements are joined by introducing the male end of one of them into the female opening of the other, with an adequate interference grade between their facing superficial layers, and they are fused, i.e. they are transformed into a single piece through them.
It is highly inadvisable to join tubes bearing a metal layer to the connections thereof by means of thermofusion, as such joining would only be accomplished between the external thermoplastic layer and the connection wall, the intermediate metal layer edge thus remaining internally uncovered, whereby water circulating through tubing would produce an oxidising process with the consequent deterioration of the metal layer, which would inevitably result in water leaks and/or contamination.
On the other hand, even where an abutting supplementary union could be done between the internal layer of the tube and an internal cylindrical surface of such connection, a highly resistant section would not be possible to obtain due to the reduced thickness of said internal layer, which section could not absorb the shearing force which causes bending of the connection wall upon the expansion due to the pressure of fluid working at high pressure, which on the other hand is easily absorbed by the tube without any alteration whatsoever due to the presence of the intermediate metal layer and which would obviously produce breakage of this joint and the resulting water-metal contact.
Consequently, connection between tube and any class of connection requires from the later to be provided with a tubular pin which is tightly inserted into said tube end, around which an external snap-fastener is applied in order to tighten same around the pin, thus creating an airtight joint between the internal thermoplastic layer of the tube and said pin. Due to said tubular pin thickness, a noticeable reduction of the tubing internal diameter is produced, giving rise to several drawbacks.
Further, this kind of connection is very expensive, not only due to the manufacturing cost of the piece itself but also due to the tools and labour required for the application thereof.
SUMMARY
It is thence the main object of the present invention the implementation of a termofused splice or joint, under maximum and total safety conditions, of a thermoplastic tube with a thermoplastic connection, by means of a thermoplastic element which may be incorporated to the tube end through thermofusion before the thermofusing operation of this end into the corresponding opening of said connection, providing such thermoplastic tube with a fully thermoplastic new with no metal layer, as through it the three layers end covering is obtained, inhibiting both internal and external contact of the metal layer edge with the connection and thus with water and further, a marked increase of the internal layer thickness is obtained, providing then a larger cross-section at the tube end, between its internal surface and said metal layer, which allows for the absorption of said bending stress which is normally produced at the joint area due to such connection expansion upon the high pressure operation of tubing.
Another object of the present invention is the provision of a clear visual or touch indication that the thermoplastic element has been included and that the connection to be made will be safe.
Another object of this invention is the application of said thermoplastic element by means of the same conventional tooling used in any thermofused joint of a thermoplastic tube and connection.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to facilitate understanding of this invention and for a better appreciation thereof, the thermoplastic element and its incorporation to the thermoplastic tube has been illustrated as follows, according to one of its preferred embodiments, wherein:
FIG. 1 shows a longitudinal cut view R-R of FIG. 2 and an exploded view of the splicing thermoplastic element and the end of tube, before attaching one to the other by means of thermofusion;
FIG. 2 is a side elevational view of the splicing element;
FIG. 3 is the same view as in FIG. 1 , showing interconnection of splicing element and the end of the tube once fused;
FIG. 4 is a schematic view showing the splicing element and the tube end applied to the corresponding nozzles of a thermofusing machine, during prior heating stage of the surfaces through which fusing of both elements is to take place;
FIG. 5 shows a longitudinal section illustrative of fusion between the splicing element and the tube end, according to FIG. 3 ;
FIG. 6 is the same as FIG. 5 , but showing splicing element after it has been applied and attached by means of thermofusion to the tube end, and ready to proceed with the final stage of thermofusion of this tube end to the thermoplastic connection;
FIG. 7 shows behaviour of the element already applied to the tube end, when it is introduced in order to be heated into the corresponding nozzle of a second thermofusing machine, for the end stage of tube to connection thermofusion;
FIG. 7 ′ is the same view as in FIG. 7 once the introduction of tube with the splicing element into the second thermofusing machine is completed;
FIG. 8 shows the end of the tube with the splicing element and connection once heated, at the beginning of said thermofusion final stage;
FIG. 8 ′ is the same view as FIG. 8 once the final thermofusion stage is completed;
FIG. 9 is an illustrative sketch from a practical example of how the thermofusion between tube end and abutting splicing element and connection has been accomplished.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 thermoplastic tube A exhibits a wall with two thermoplastic layers, an external a and an internal a′, made of, for instance, polypropylene or polyethylene, with an intermediate metal layer a″ made of, for example, aluminum foil adhered to both faces a and a′, exhibiting, for example, a total wall thickness of 2 mm, i.e. 0.7 mm represented by external layer, 1.0 by internal layer and 0.2 by intermediate aluminum foil, both faces being provided with an adhesive cover 0.05 mm thick, all these dimensions being given by way of example.
Splicing element C has been developed as an injection pre-moulded fully thermoplastic tubular sleeve, for example, which diameter is larger that that of the tube itself, so that in order to be applied at the tube A end a socket mouth e, which is obtained by expanding end I of said tube A, should be previously formed.
It is the purpose to attain said expansion of tube end in a range of from 10% to 20% of the diameter of intermediate metal layer a″ diameter, for all of the tubing diameters, and up to 15% in the particular case of an aluminum layer exhibiting the above mentioned dimensions.
This splicing element C which form is substantially that of a tubular sleeve exhibits only one internal diameter and two external diameters, which define a cylindrical external portion c which exhibits a rectangular longitudinal section which external diameter is the same as that of the expanded end I of thermoplastic tube A and which exhibits a side wall P abutting against tube end 2 and a height such that it covers the three layers of said tube, and a tubular projection c′ which external diameter slightly larger than the internal diameter of expanded end I of tube and an internal diameter which is substantially equal to the internal diameter of tube A. Interference between said diameters is of from about 0.4 to 0.5 mm.
As regards length of c′ dimensioning thereof has been considered according to a length smaller than that of expanded end I.
It is to be noted that above mentioned drawings illustrate said splice element C and a supplementary ring C′, which will be described below, as integral part thereof, not participating in this application stage of splice element C of tube A end, it merely remaining incorporated to the latter in order to be used at the end of the process of thermofusion between said tube and the connection piece in the manner and to the end to be explained below.
External portion c of element C exhibits a rear lateral wall P′ which will become tube A new end itself upon completion of the operation of element C fastening onto said socket mouth e as shown by FIGS. 3 and 6 .
Such fastening will be accomplished by means of the direct and simultaneous thermofusion of abutting side wall P of element C to the joint end 2 of both thermoplastic layers a and a′ and from said tubular projection c′ to said internal thermoplastic layer a′, according to the typical thermofusion technique, by heating on the one hand said abutting side wall P, external surface 4 of tubular projection c′ and its external edge 4 ′, and on the other hand said joint end 2 of tube and internal socket e internal layer, then introducing said tubular projection c′ into socket e until said side wall P abuts against said joint end 2 , all of the above under the required pressure and interference degree in order to obtain a firm interfusion between facing surfaces of both elements ( FIGS. 4 , 5 and 6 ).
The above described operation may be carried manually using female t and male t′ nozzles provided on both sides of a first thermofusing machine T-I.
This operation of splice end C heating and subsequently, its application to the end of tube A could be carried out manually, maintaining splice element C applied on female nozzle t of the thermofusing machine in order to get a maximum contact between abutting lateral wall P of external portion c of element C, and the respective seat 8 of this nozzle t, and of external surface 4 of splicing element C against wall 9 of female nozzle t and its external edge 4 ′ against the corresponding back step 9 ′, in order to be sure that all of the element surface which is to actively act during the interfusion process with the joint end 2 and internal layer a′ but maintaining the internal face of the projection and the splice element adequately “cold” in order to avoid collapsing of piece.
On the other hand, on male nozzle t′, internal layer a′ of the wall of expanded end I of tube A tightens laterally on a corresponding projection 10 thereof, and at the same time joint end 2 of tube A tightens at its base, obtaining the heating required for its interfusion with tubular projection c′ and abutting lateral wall P of splice element C.
Subsequently, both are removed from the thermofusing machine, in order to be mutually faced and to gradually introduce element C into mouth socket e of tube end I, applying said element as if it were a stopper into a bottle, first forcing entering of tubular projection c′ into tube A internal wall a′ according to the established interference degree, wherein its external edge 4 ′ proceeds at the superficial portion of the internal layer forming a lip 11 which aids in sealing the joint between both walls until abutting wall P of splice element reaches the bottom and fuses against the joint end 2 of the three layers of tube A ( FIG. 6 ).
Thus a firm union by thermofusion is obtained between element C and tube A end which comprises an abutted joint II with both thermoplastic layers, and which continues with a pin joint III between internal layer of tube A and said tubular projection c′ of element C, virtually wedged inside same, as illustrated by FIG. 6 , such that behaviour of said element as an integral part of tube A is assured, with said metal layer fully enclosed by thermoplastic material.
At the same time, tube end is internally reinforced, offering a larger annular section between metal layer a″ and tube internal surface at the union sector where bending stress is to be present upon tubing working at high pressure, due to the fact that the connection tends to expand, whereas the tube remains unaffected, because of the contention granted to its metal layer, as already mentioned.
As may be appreciated from what has been described and illustrated, incorporation of this splice element introduces no reduction of tube conduit, as the inner diameter of tubular projection c′ is substantially equal to tube original internal diameter, and is fully within the expanded end I thereof ( FIG. 6 ).
It is clear that by the incorporation of this element, tube A end is conformed as a single layer conventional tube, which external and internal surfaces end at a thermoplastic front which comprises all of the wall thickness and, accordingly, may be thermofused within a connecting piece as per the usual technique, heating said end and the interior of the corresponding nozzle of the connection and introducing one into the other with an interference extent between its lateral surfaces as required for the obtention of a sound welding between same, without any risk of its intermediate metal layer being exposed.
According to a preferred embodiment, inclusion within the scope of this invention has been contemplated of a control element which upon completion of the final stage of the thermofusion process between tube end, already bearing splice element C, and connection piece B, will provide a clear physical and external indication that said tube end incorporates said splice element and that this joint is safe, i.e. there is no risk for water to contact tube metal layer.
Accordingly, and as a supplementary element to the above arrangement, it has been contemplated the temporary inclusion at splice C of a supplemental ring C′, initially formed as an integral part of said element C ( FIGS. 1 and 2 ), shaped as an annular piece incorporated as a collar of larger diameter than said element C and which surrounds same concentrically, with an appreciable gap between them, they being joined only by a very thin intermediate wall 12 as a membrane arranged at the place where sweeping by the thermofusing machine nozzle is to take place. Said thin intermediate wall 12 thickness is such that such sweeping may only take place if the thermofusing machine provides an adequate thermofusing temperature. Thence, said auxiliary ring C′ acts as a control of the minimum necessary temperature of the thermofusing machine nozzle.
This auxiliary ring C′ has an internal diameter which is noticeably larger than the external diameter of the expanded wall of the tube, such as to fulfil a second auxiliary function, i.e. as a control of splice element C positioning, as we will see hereinbelow.
According to the above, element C is thermofused at the tube end as shown and illustrated by FIGS. 4 , 5 and 6 , bearing this auxiliary washer C′, which has remained separated around same, wherein thermofusion between said splice element and tube is limited to joint end 2 of tube and stop P of this element C and though this auxiliary ring C′ will receive some heat, indirectly radiated by splice element and its proximity to the thermofusing machine mouth socket, it is subject to no stress, as the fusion pressure is exerted only between one and the other, leaving aside this auxiliary ring, as shown by FIG. 4 schematics, wherein respective nozzles t and t′ of the first thermofusing machine T-I employed during this preparatory stage for the heating of the parts which are to be joined: end I of tube A and element C.
Thus, element C is applied to end of tube bearing said auxiliary ring C′ around same, as illustrated by FIG. 6 , such that when at the stage of heating tube end, upon the introduction thereof into nozzle t″ of the second thermofusing machine T-II ( FIG. 7 ), at the final stage of the process, this auxiliary ring C′ abutts against mouth 13 ′ of end 13 thereof and intermediate wall 12 which joins same to splice C yields, provided temperature of nozzle t″ of thermofusing machine T-II is the adequate one, it ruptures and thus freely slides on the tube easily and, pushed by this end of said nozzle t″, is finally at the distance of tube A end corresponding to penetration length thereof in the latter (FIG. 7 ′), all in such a way that, upon retrieving tube from this nozzle t″ of thermofusing machine, this auxiliary ring C′ is applied around its expanded end I as a “control”, showing that same bears element C, which is schematically illustrated by FIG. 8 at the beginning of tube penetration into female portion b of connection B.
It is clear that this auxiliary ring C′ is an accessory means that protects operator who may have omitted application of splice element according to the invention, without participating thence in the formation of the new thermoplastic end which seals the union between external and internal layers caps, over the edge of the aluminium cap.
When carrying out this final stage of thermofusion introducing end of tube A into female part b of connection B, auxiliary ring C′ follows ( FIG. 8 ) until it is virtually applied on socket 14 ′ of female part b, gradually tightening around said tube wall due to the natural, albeit reduced, expansion produced under the compression stress between both elements which is required by its forced insertion and also to the natural outwards creepage of both facing superficial layers 15 - 16 on the side of element C and tube A and 17 by connection B and as a consequence thereof this auxiliary ring C′ tightens over the material which tends to flow forming the classic external curl 18 which it contains, all of which may be appreciated on FIGS. 8 and 8 ″.
Lastly, reference must be made to the design adopted for this auxiliary ring C′, depicted by FIGS. 1 and 2 , with which it has been the intention to reduce thickness and amplitude of intermediate wall 12 which joins same to element C body, providing at the same time a configuration such that it contributes in maintaining it away from heat originated from the thermofusing machine at the end of the tube ( FIG. 4 ), thus reducing any possibility of the degradation thereof.
On the other side, and in order to assure that this auxiliary ring C′ is clearly and easily seen, around union, between tube A and connection B, once thermofusion is completed between both elements thus assuring that the coupling element has been applied at the end of the tube, not only has it been provided with an ample diameter, but it has further been equipped with several cylindrical projections 19 which protrude from the external periphery thereof underlining the presence of this washer, providing an easy tactile detection in those cases in which such detection is not visually possible. Also, it may be provided with colours contrasting that of the thermoplastic tube, so as to facilitate its visual detection.
Regarding the above mentioned final stage of the thermofusion process between connection B and new end of tube now formed by element C, it has been foreseen the establishment of an axial abutting joint, again by thermofusion, between element and internal step 20 ′ of connection wall 20 , incorporating between them melted material which flows into the interior of the connection as an effect of the interfusion of facing lateral surfaces of the tube wall with splice element included and the connection wall, as schematically depicted by FIG. 8 ′ as an attempt to contain this creepage and thus increase contact pressure between said surfaces, reducing size of typical curl 21 formed inside the connection so it does not protrude within the tubing conduit.
In order to better understand how it is done in the practice, the referred thermofusion union between the wall of the tube end, including element and connection wall, it is included as FIG. 9 depicts a reproduction of a sketch from a digital image obtained from a partial longitudinal section of a sector of said union, where it can be seen the deformation and creepage of surfaces of either element which are mutually fused, establishing a perfect sealing between them, with the intermediate metal layer of the tube being isolated from any internal or external contact.
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It is the object of the present invention a thermoplastic element for the protection against corrosion in the thermofused splicing of a thermoplastic tube to a thermoplastic connection, which element has the shape of a fully thermoplastic tubular sleeve, able to be introduced into a socket mouth formed by the expansion of the tube end, said splice element bearing only one internal diameter and two external diameters which define a cylindrical external portion of larger diameter and a tubular projection which diameter is smaller than the former, and which is introduced into the thermoplastic tube, a lateral wall of the external portion defining a front butt of said thermoplastic element against the end of the thermoplastic tube. Said splicing element also exhibits an auxiliary ring which operates as a reference point for the assembly thereof.
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This application is a continuation of application Ser. No. 748,203, filed June 24, 1985, now abandoned without prejudice in favor of the present case.
FIELD OF THE INVENTION
The present invention relates to a chute used for separating and selecting particulate or flat agricultural products such as grains and beans, or particulate mineral and industrial products, by means of detecting surface color tone; and, more especially it relates to such a chute for delivering the particulate materials to be selected to a measuring point in such a way as to optimize optical selection.
BACKGROUND OF THE INVENTION
Optical selectors apply a light to articles to be selected, such as falling particles, measuring light which is reflected and transmitted from the particles, and finally, if there is any abnormality in the surface color tone, detecting those articles or particles which have such a difference in light quality so that the abnormal particle or article is eliminated by means of a blast of air. In that case, there is a necessity of adequately dispersing the particles so as not to pile them up at the location at which the quality of light transmitted therethrough and reflected therefrom is measured. For that purpose, the articles to be selected are accelerated by means of a chute to prevent any build-up. The chute is installed at a vertical inclination, the articles to be measured being supplied at the upper part of the chute, the dead weight of the articles causing them to slide along the surface of the chute. However, if the bottom surface of the chute is simply planar, the articles to be selected may become concentrated only on one side of the chute during their decent.
In order to prevent such a tendency, it has been proposed to provide the chute with corrugations or grooves near the bottom. Even so, if a chute with simple corrugations is used, the downwardly flowing articles tend to become vertically piled up when the flow rate increases, and this presents problems in measurement of the light quantity. For example, if the articles to be selected become piled up, it becomes impossible to measure the quantity of reflected light from certain particles; similarly, if transmitted light is used, the detection of abnormal articles becomes difficult because of a decrease in the light quantity when the articles become piled up. Although such a problem rarely occurs if the articles to be selected have a shape which is approximately spherical, such a problem causes serious concerns particularly when the shape of the articles is flat or long and narrow.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to overcome deficiencies in the prior art, such as indicated above.
It is another object to provide for the improved feeding of articles, such as those having a particulate form, to an optical selector.
It is a further object of the invention to provide a chute for feeding to an optical selector articles to be selected which are small in size and simple in structure.
Yet another object of the present invention is to provide a chute capable of suitably accelerating the articles to be selected to the selection site where selection is executed by an optical selector.
Yet a further object of the invention is to provide a chute capable of having the particles to be selected, which are falling downwardly on the chute, fall in such a way that they are distributed uniformly across the full width of the chute, and also flow downwardly in a linear way.
A still further object of the present invention is to provide a chute wherein when the flowing quantity is increased, the articles to be selected do not become piled up, but instead extend in a sideways direction.
A still further object of the invention is to provide a chute wherein, if the shape of the particulate articles are flat or long and narrow, such particles do not pile up while traveling down the chute.
A still further object of the present invention is to provide a chute capable of increasing the accuracy of selection and enhancing the working efficiency of such selection, when used in conjunction with an optical selector.
BRIEF DESCRIPTION OF DRAWING
Other features and advantages of the invention will be made more apparent by consideration of the following detailed description taken in conjunction with the attached drawings, wherein:
FIG. 1 is a perspective view of a preferred embodiment of the chute according to the present invention;
FIG. 2 is a plan view of the chute of FIG. 1;
FIG. 3 is a partially enlarged sectional view of the chute of FIG. 1;
FIG. 4 is a schematic view in outline of the mechanism employing a selector using the chute according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The general construction and shape of an embodiment of a chute according to the present invention is shown in FIG. 1. The chute 10 has a bottom surface 11 on which the articles to be selected slide. Such bottom surface 11 comprises a plurality of long and narrow individual plates 12, which are sufficiently long to accelerate the articles to be selected up to the desired speed. As shown in FIG. 3, each plate 12 has a bottom surface which is gently corrugated from one side wall 15 to the other side wall 15, such corrugations having valleys 13 and ridges 14. As FIG. 3 is a cross-section along the width of the device, it will be understood that the gentle corrugations in question run the entire length of each of the plates 12.
Such gentle corrugations have a width P and a depth D as well as an angle of inclination A. These dimensions are variable, depending on the type of articles to be handled by the chute, although in general it will be seen that the width P is substantially greater than the depth D, and that the angle A is small. Additional information is provided below for various specific embodiments.
Referring again to FIG. 1, it will be seen that several plates 12, arranged side-by-side, constitute the sliding bottom face 11 of the chute. The side walls 15 of each plate are interposed between adjacent plates 12 with supporting members 16 being located on the extreme sides of the chute, the supporting members 16 and the sides 15 of the plates 12 being fixed to one another by means of connecting rods 17. The connecting rods 17 not only penetrate the side walls 15 of the plates 12, but are also mounted so that they penetrate and pass through spacers 18 which are inserted into the gap between the side walls 15 of each plate 12, such spacers 18 serving to restrict the dimensions of the gaps. Nuts 19 are screwed to both ends of the rods 17, and when the nuts 19 are tightened, they fix the plates 12 between the supporting members 16. By selecting a rod of proper length and the desired number of plates 12, one can achieve a chute of desired width. In addition, because the chute 10 is formed of the individual plates 12 and held together by rods 17 and nuts 19, with spacers 18, the surface of the chute is not likely to become warped, and this results in a more accurate and predictable traversal of articles to be selected which fall in a linear manner.
FIG. 4 schematically shows a selector using the above-described chute 10, such chute being mounted at a vertical inclination with particulate articles to be selected being supplied to the upper part thereof, whereupon such articles slide down the chute along the bottom surface 11 thereof. During the sliding, because the surface 11 of the chute 10 is corrugated, the articles to be selected tend to slide or fall along the grooves or valleys 13. Such an arrangement insures that the articles to be selected fall linearly rather than in an erratic path. Furthermore, because the corrugations are gentle, when two particles to be selected flow downwardly along the chute close to one another, they are capable of moving sideways rather than becoming piled up, and this results in avoidance of the particles becoming piled up in one area.
The articles to be selected, which have thus fallen, spring from the lower end of the chute 10 at their predetermined speed. The articles to be selected which have sprung from the chute 10 reach a measuring point 20 located near the lower end of the chute 10. A light from one or more lamps 21 is applied to the double back and front surfaces of the articles to be selected, when they pass the measuring point 20. The reflected light from the articles to be selected, or mixed reflected and transmitted light reaches photo sensors 22 on both the back and front parts. On the other hand, light from the lamp 21 may be applied to backscreens 23 and the reflected light from the backscreens 23 reach the photo sensors 22. The quantity of the reflected light from the backscreen 23 should be in some ratio, such as equal to, the quantity of reflected light or mixed reflected and transmitted light from the particulate articles to be selected which indicate the normal surface color tone.
Yet if the articles to be selected which reach the measuring point 20 are normal, the quantity of light reflected from them turns out to be identical to that of the light from the backscreen 23, in which case the photo sensor 22 is not actuated. In the case of articles having a surface color tone which is abnormal, there will be a difference between the quantity of light reflected from them and that of the light from the backscreen, in which case the photo sensor 22 will detect the abnormality. Upon the detection of such an abnormality by the photo sensor 22, a signal from it is fed to an air injector 24 which instantaneously injects air thereby blowing the falling particulate article into a different path. The air injector 24, located under the measuring point 20, is adjusted so that when an abnormal particle which has been detected at the measuring point 20 falls downward to the position of the air injector, air is blasted from the air injector in order to blow the abnormal article out of its normal trajectory.
The particles which are blown out by the injected air fall into a receiving conduit 25 for abnormal particles, whereas the particles which do not receive the blast air enter into the receiving conduit 26 for normal particles. Thus, the particles which are abnormal in their surface color tone are selected to be eliminated. Because there may sometimes occur the case where the normal particles which are located near the abnormal particles enter into the receiving conduit 25 together with abnormal particles, those particles which have been collected in the abnormal particle receiving conduit 25 are reselected, thereby eliminating only abnormal particles.
The sensors 22 and the air injector 24 constitute an assembly which is illustrated in FIG. 4 in only one plane. Actually, however, the system employs a plurality of sensors 22 and air injectors 24 located beneath the exit point from the chute lying beneath each groove 13. In the illustrated embodiment, as there are eighteen grooves or valleys 13 of the chute 10, it will be understood that what is shown in FIG. 4 is replicated 18 times, each sensor 22 performing the inspection of the quantity of light and the air injector 24 applying the injected air to each of the 18 units.
The preferred examples of the shape of the corrugations of the chute 10 are described as follows. The preferable shape of the corrugation may be varied depending on the kind of articles to be selected, so long as the corrugations are maintained gentle. The following recommended ranges are preferred for the distance P between two adjacent ridges 14 and the depth D from the top of the ridges 14 to the bottom of the valleys 13, it being understood that in general the dimension P may range from 5 mm to 30 mm and the dimension D from 0.1 mm to 5 mm. The preferred range of inclination of the corrugated surface of the chute is from 1° to 20°.
If these dimensions are not adhered to, the following worst case phenomena may take place. For example, in the case of an inclination A of less than 1°, when the articles to be selected fall they may be moved sideways so that they will not fall in a linear way; this usually becomes a significant problem when the flowing quantity is small. On the other hand, in the case of an angle of inclination A of over 20°, when the flowing quantity is relatively great, the phenomenon takes place in which the particulate articles to be selected will become piled-up.
The preferred range for each value for various articles to be selected are summarized as follows.
EXAMPLE I
In the case where the particle articles are grains of rice or wheat, the dimension P should be 5 mm-15 mm, D should be 0.3 mm to 1.0 mm and angle A should be 3° to 8°.
EXAMPLE II
Where the articles are dry noodles 1.2 mm in diameter and 15 mm long, the dimension P should be from 5 mm to 20 mm, dimension D should be from 0.2 mm to 2.5 mm, and angle A should be from 2° to 16°.
EXAMPLE III
In the case of sliced almonds, P should be from 15 mm to 30 mm, D from 0.5 mm to 4.5 mm, and A from 3° to 18°.
EXAMPLE IV
In the case of cotton nuts, P should be from 5 mm to 20 mm, D from 0.5 mm to 3.0 mm and A from 5° to 18°.
The foregoing description of the specific embodiments will so reveal the general nature of the invention that others can, by adapting current knowledge, readily modify and/or adapt such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to understood that phraseology or terminology employed herein is for the purpose of description and not of limitation.
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A chute for an optical selector has a corrugated bottom surface in order to insure that particulate articles to be selected flow linearly and are dispersed uniformly across the width. The corrugations along the bottom surface of the chute are gentle having a small ratio of height to pitch of corrugation, and such corrugations provide shallow valleys which extend linearly from the upper infeed end of the chute to the lower discharge end. When the particulate articles to be selected flow down the chute, they accordingly flow in a linear way rather than following a curved path, but if the flowing quantity becomes so great as to normally cause a vertical piling up at the discharge end, the particulate articles will move sideways rather than piling up.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to spinning discs and, more specifically, to games utilizing spinning discs.
2. Background Description
Numerous games involve one or more players throwing or hitting various projectiles past one or more other players into a net or boundary area or over a line defended by the other players. One popular game uses a spinning disc which, in a non-competitive activity, can be tossed and caught by two or more players. Such discs are used in competitive contests involving teams of one or more players where the object is to catch the disc thrown by the other player or team before it strikes the ground. Such discs have also been used in a target-type game wherein nets are spaced apart in a preset layout similar to a golf course. Two or more players traverse the layout from net to net with the object being to achieve the least number of tosses of the disc into each net over the entire layout.
While such games are enjoyed by numerous people, it would still be desirable to provide a toss-type game, particularly one involving a spinning disc, which combines conventional throw and toss game objectives with target/defend game features. It would also be desirable to provide such a game which is easy to set up and to play. It would also be desirable to provide such a game which can be easily adjusted in layout configuration to provide enjoyable and/or competitive play at different skill levels.
SUMMARY OF THE INVENTION
The present invention is an apparatus and method of playing a game utilizing a spinning, aerodynamic-shaped disc.
The inventive method comprises the steps of:
a) forming a throwing area;
b) forming a target area spaced a variably selectible distance from the throwing area;
c) forming the target area with a front boundary line having a variably selectible length between opposed ends, and a pair of spaced side lines, the side lines having an identical variably selectible length extending from opposite ends of the front boundary line;
d) the first player standing in the throwing area and hurling a projectile to land in the target area without being caught by the second player; and
e) the second player standing in the target area and attempting to catch the projectile within the target area before the projectile lands within the confines of the target area formed by the front boundary line and the pair of side lines.
The step of forming the target area further comprises the optional step of forming a back boundary line spaced from the front line by a variably selectible length and extending between ends of the side lines.
The throwing area and the target area are formed by means of a kit which includes:
a) at least first and second groups of elongated, planar members, the members in the first group having a different length than the members in the second group; and
b) means for removably attaching the members to a playing surface to form the throwing area, and to form the target area with at least a front boundary line spaced a variably selectible distance from the throwing area and a pair of side lines extending from opposite ends of the front boundary line.
One or several of the members of the first and second groups of members are arranged end-to-end and extend between the throwing area and the target area to space the throwing area from the target area by a distance equal to the length of the end-to-end arranged members.
Selected ones of the members of the first and second groups of members are interconnected end to end to form the front boundary line and the pair of side lines of the target area of variably selected lengths.
Selected ones of the members of the first and second groups of members may be connected end to end and spaced from the members forming the front boundary line and connected at opposite ends to one end of the members forming the side lines to form a back boundary line for the target area.
Preferably, the members of the second group of members have a length twice as long as the members of the first group of members. The first and second groups of members are preferably arranged to form a polygonal shaped throwing area and a polygonal shaped target area.
Apertures are formed at the ends of each of the members of the first and second group of members. Stake means are insertable through the apertures in the members and engagable with the playing surface to fixedly position the members on the playing surface.
The present game kit and method provide an enjoyable game utilizing a spinning disc which can be easily set up for play. Further, the game kit enables various boundaries of the game to be adjusted according to varying skill levels thereby enhancing the enjoyment and/or competition features of the game for players having different levels of skill.
BRIEF DESCRIPTION OF THE DRAWING
The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:
FIG. 1 is a perspective view showing the game kit of the present invention arranged in first and second skill level layouts;
FIG. 2 is an enlarged, partial view showing the connection of the boundary members to an underlying playing surface; and
FIG. 3 is a perspective view showing the game kit of the present invention arranged in third and fourth skill level configurations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, and to FIG. 1 in particular, there is disposed one embodiment of the present invention which illustrates both the game apparatus and method of playing a spinning disc game.
In general, the game apparatus and the method of playing the game utilizes a spinning disc 10 which is thrown by a first player 12 located in a throwing area 14 toward a target area 16 which is defended by a second player 18. The kit apparatus includes a plurality of elongated planar members arranged in first and second groups. The members 20 in the first group have a different length than the members 22 of the second group. Preferably, the members 20 of the first group are half the length of the members 22 of the second group.
By way of example only, the members 20 in the first group of planar members have a length of approximately five yards, two inches; while the members 22 in the second group of elongated planar members have a length of approximately ten yards, two inches.
A front boundary for the throwing area 14 may be formed by two short length members 24 which form a third group of elongated planar members which have a length of approximately one half the length of the first members 20, such as 2.5 yards, two inches, by example only.
The planar members 20, 22 and 24 are preferably formed of thin, flat strips formed of a suitable material, such as plastic or cloth, which are arranged to form the boundaries of the throwing area 14, the target area 16, and a variable length spacing distance 26 between the throwing area 14 and the target area 18. The strips have a width of four inches, by example, to form a easily distinguishable boundary line.
Instead of flat plastic strips, the planar members 20, 22 and 24 may also be formed of other suitable materials, such as string, chains and even chalk boundary lines.
Apertures formed by eyelets 30 are formed at opposite ends of each of the planar members 20, 22 and 24 as shown in detail in FIG. 2. As shown in FIGS. 1 and 2, the apertures formed by the eyelets 30 at overlapped ends of two members 20, as well as overlapped ends of members 20 and 22, are aligned and receive a suitable stake 32 or post which forms a stake means for removably attaching the planar members 20, 22 and 24 to an underlying playing surface, such as the ground. The stakes 32 are provided in a predetermined number in the present game kit and preferably have an elongated, pointed end which is insertable through two aligned eyelets 30 and into the underlying playing surface. The stakes 32 may be formed of any suitable material, such as plastic, with nylon being preferred, as well as metal, wood, etc. By way of example only, the stakes 32 are formed as elongated cylinders having a length of three inches and a 3/4 inch diameter. An enlarged flat head of 11/2 inch diameter, by example only, is formed on the upper end of each post 32 to aid in retaining the overlapped ends of the members 20, 22 and 24 together in the desired boundary configuration.
The stakes 32 and the boundary members 20, 22 and 24 of the game kit are provided in predetermined numbers to form multiple layouts and may be conveniently stored in a specially designed container, not shown, for easy transport.
FIG. 1 shows a first game layout in which the throwing area 14 has a polygonal shape, preferably a square shape. It will be understood that other polygonal configurations, such as rectangular, triangular, etc., as well as other shapes, such as circular, hemispherical, etc., may also be used to form the throwing area 14.
In a preferred embodiment, the throwing area 14 is formed of three first members 20 which are arranged in an overlapping, end-to-end, perpendicular configuration to form a square. Two short members 24 are overlapped end to end and interconnected between ends of two of the first members 20 to form a front boundary line for the throwing area 14 as shown in FIG. 1. The first offensive or throwing player 12 must remain at all times within the throwing area 14 defined by the interconnected members 20 and 24.
A spacing line 26 extends between the throwing area 14 and the target area 16. In a first embodiment for players of a first or beginning skill level, the spacing line 26 is by way of example only, fifteen yards in length. This length may be obtained by three end to end arranged first members 20 or one first member 20 connected end-to-end with one second member 22 as shown in FIG. 1. The outermost ends of the overlapped members 20 and 22 are interconnected by means of stakes 32 to the center of the front boundary line formed by the members 24 in the throwing area 14 and a front boundary line in the target area 16. Alternately, the short members 24 can be eliminated from the game kit and a first member 20 used to form the front boundary line of the throwing area 14. In this arrangement, one end of the end-to-end members 22, or 20 and 22 are fixed to the playing surface by a stake 32 immediately adjacent to the forwardmost edge of the member 20 forming the front boundary line of the throwing area 14.
The target area 16 also has a polygonal configuration, which is rectangular by way of example only. The front boundary line 36 of the target area 16 is formed of two identical, end-to-end arranged second members 22 which combine to form an overall front boundary length denoted by reference number 36. Opposed side lines 38 and 40 of identical length extend from opposite ends of the front boundary line 36, generally perpendicular to the front boundary line 36. In the first skill level game layout, a back boundary line denoted by reference number 42 is formed by two overlapped, end-to-end arranged second members 22 which are interconnected by means of stakes 32 to opposite ends of each side line 38 and 40.
The dimensions of the first skill level game layout, as well as additional, higher skill level layouts are shown in the attached table.
______________________________________ throwing target target area - area area target front side target area boundary lines area back spacing 36 38, 40 boundary distance length length 42 length 26 (yds) (yds) (yds) (yds)______________________________________Beginner 15 10/10 10 20Inter- 15 10/10 20 20mediateAdvanced 20 15/15 20 30Pro 20 15/15 30 or none more______________________________________
The first row in the table shows the dimensions of the target area 16 and the spacing distance 26 as described above. The second row in the table for intermediate skill level players shows enlarged side line dimensions for the target area 16, shown in phantom in FIG. 1, which are formed by adding an additional second member to each side line 38 and 40 to increase the length of each side line 38 and 40 to the distance denoted in the table. In this second game layout, the back boundary 42 remains the same length as the front boundary 36 in the first skill level layout.
FIG. 3 depicts third and fourth game layouts for advanced and professional skill level players. In the third embodiment denoted by the third row of the table, the front boundary 36' is increased in length from that shown in FIG. 1 and described above by adding an additional first member 20 to the outer end of each second member 22. The ends of each first member 20 and second member 22 are overlapped and interconnected by individual stakes 32 in the same manner as described above and shown in FIG. 2. The back boundary 42' is formed to the same length as the front boundary 36' by three overlapping end to end arranged second members 22. It should be noted that in this third game layout, the side lines 38' and 40' remain the same as the length of the side lines 38 and 40 in the second layout shown in the table and FIG. 1 in phantom.
The third game layout shown in FIG. 3 may also be modified to a fourth game layout as shown in the fourth row of the table by extending the length of each side line 38' and 40' by adding at least one additional second member 22 to one end of the second members 22 forming each side line 38' and 40'. Additional second members 22 may also be added to extend the length of each side line 38' and 40' to any desired length. The back boundary of the fourth game layout, as shown in the table, is open or non-existent. Optionally, a back boundary shown in phantom in FIG. 3 may be provided at the ends of the endmost second members 22 forming the side lines 38' and 40'.
Since the members 20 of the first group are half the length of the members 22 of the second group, two end-to-end arranged members 20 may be interchangeably used in place of one member 22 and vice versa to form any portion of a boundary line in any game layout.
In playing the game of the present invention, the object is for the offensive player 12 to hurl the projectile or disc 10 toward the target area 16 in an attempt to land the disc 10 on the playing surface within the confines of the target area 16 before the defensive player 18 catches the disc 10. At the same time, the objective of the defensive player 18 in the target area 16 is to catch the projectile 10, while remaining within the confines of the target area 16 before any part of the projectile 10 contacts the playing surface within the boundary of the target area 16.
By example only, the game of the present invention can be patterned after the game of baseball with a number of innings, such as nine. Three outs per inning are provided for each player who alternate as offensive and defensive players. A goal or point is obtained each time the offensive player 12 is successful in having a hurled disc 10 contact any part of the playing surface within the boundary of the target area 16 before the defensive player 18 catches the disc 10. An "out" is achieved each time the defensive player 18 catches the disc 10 while remaining within the confines of the boundary of the target area 16 at the time of catching the disc 10 or whenever the disc 10 thrown by the offensive player 12 does not land within the target area 16 and is not touched by the defensive player 18. A catch is still made by the defensive player 18 if he or she completes a catch of the disc 10 with both feet within the boundary of the target area 16 even though momentum may cause the defensive player to subsequently step out of the target area 16.
It should be noted that even if the defensive player 18 catches the disc 10, a point or goal is still scored if the disc 10 contacts the playing surface within the target area 16. A point or goal is also scored if the defensive player 18 contacts the disc 10 within the target area 16 without catching it, regardless of where the disc 10 lands inside or outside of the target area 16.
For enjoyment and/or speed of play of the game, certain other rules may be adopted. For example, the offensive player 12 must remain within the confines of the throwing area 14, without stepping on or beyond any of the boundary members 20 or 24 during each throwing attempt. The offensive player 16 must also face the defensive player 18 at all times during each throwing attempt. A certain time interval, such as ten seconds, may be imposed on the offensive player 12 during which the offensive player 12 must make a throw attempt. Further, at no time during the flight of the disc 10, can the disc 10 exceed a 45° angle from level in any direction. Other rules may also be adopted, similar to those used in baseball, to ensure fair play of the game.
In summary, there has been disclosed a unique spinning disc game kit or apparatus and method which provides an exciting and enjoyable game involving a spinning disc. The game kit is easy to set up and may be varied in configuration depending upon the level of skill of the players.
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A game kit and method of playing a game using a spinning disc. The game kit includes boundary elements which are selectively arranged to form a throwing area, a target area, and a distance between the throwing area and the target area in variably selected sizes and distance spacing according to the players level of skill. A spinning disc is thrown by one player located in the throwing area toward a second player located in the target area who must catch the disc before the disc contacts the playing surface within the target area to prevent the throwing player from being awarded a point. The players alternate throwing and defending according to rules of play of the game.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to blenders. More particularly, the present invention relates to hand held blenders.
[0003] 2. Description of the Related Art
[0004] Hand held blenders including immersion blenders, are well known. Typically, these blenders have a tall, tubular hand grip portion that contains a drive motor, to which a shaft that may be immersed into a liquid or mixture is connected. The shaft typically has an input end operatively connected to the drive motor and an output end operatively connect to a processing tool, such as, for example, a whisk attachment (good for whipping cream), and other accoutrements, such as strainers or beakers, to puree or chop or otherwise mix the contents of individual drinks or the like.
[0005] These hand held blenders are very practical for their specific purpose. Conventionally, such blenders are used in combination with any of a variety of separate containers to process (e.g., mix, chop, cut, etc.) any of a variety of different food stuffs of various consistencies from solid to viscous to liquid.
[0006] These hand held, immersion blenders, sometimes referred to as stick blenders, can have transmission shafts of approximately 6 to 8 inches in length. Consequently, in operation, any inefficiency at the input end of the transmission shaft is amplified at the output end thereof. Also, the elongated nature of these blenders makes efficient cleaning and storage a challenge.
[0007] Thus, it is an advantage for effective operation, storage and/or cleaning purposes to provide a hand held blender that ensures a reliable and stable connection between the transmission shaft and the drive motor, and that provides that the connection is quickly and easily releasable via a user interaction. It is also desirable to provide such a hand held blender with two or more hand grip portions to facilitate efficient operation of the blender during use.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an effective and versatile hand held blender.
[0009] It is another object of the present invention to provide a hand held blender that ensures a reliable and stable connection between a transmission shaft and a drive motor.
[0010] It is still another object of the present invention to provide a hand held blender that provides that the connection between a transmission shaft and a drive motor is quickly and easily releasable via a user interaction.
[0011] It is yet another object of the present invention to provide a hand held blender that has at least two portions, each preferably having a connector that provides a hermetic seal and allows each portion to be separately cleaned and/or stored without compromising the inner workings thereof.
[0012] It is a further object of the present invention to provide a hand held blender that has one or more hand grip portions to facilitate efficient operation of the blender during use.
[0013] It is still a further another object of the present invention to provide a hand held blender that facilitates uniform blending and/or comminuting results via effective and efficient handling of the blender.
[0014] These and other objects and advantages of the present invention are achieved by a hand held blender having at least a two portions, each portion preferably having at least one connector suitable to rotatably connect and/or disconnect the at least two portions, as desired, in a reliable and stable manner. In addition, the hand held blender may be provided with two or more handles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a first side view of a hand held blender in accordance with an illustrative embodiment of the present invention, showing a first portion and a second portion disconnected from each other or in a disengaged state;
[0016] FIG. 2 is a side section view of the hand held blender of FIG. 1 , showing the first and second portions connected to each other or in an engaged state;
[0017] FIG. 3 is an exploded view of the second portion of the hand held blender of FIG. 1 ;
[0018] FIG. 4 is a top plan view of the second portion of the hand held blender of FIG. 1 ; and
[0019] FIG. 5 is a bottom plan view of the second portion of the hand held blender of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring to the drawings and, in particular, FIG. 1 , a hand held blender in accordance with an illustrative embodiment of the present invention is shown and generally represented by reference numeral 1 . Hand held blender 1 essentially has a first body or portion 10 suitable for handling by an operator and for accommodating a drive motor 12 , and a second body or portion 14 suitable for use in combination with any of a variety of separate containers to process (e.g., mix, chop, cut, etc.) any of a variety of different food stuffs of various consistencies from solid to viscous to liquid via a third portion 16 operatively connected to drive motor 12 by one or more transmission or rotating shafts 18 , shown best in FIG. 2 .
[0021] Referring to FIGS. 1 and 2 , first portion 10 can have a device for providing power to blender 1 , such as, for example, a power cable 20 , one or more handles 22 , preferably ergonomically formed to provide easier handling during operation, a chamber or housing 24 for accommodating at least a portion of drive motor 12 and possibly a cooling system (e.g., a fan), one or more controls 26 (e.g., power on/off, speed, safety, etc.) preferably providing the operator with a wide array of operating options, and at least one first connector 32 facilitating second portion 14 being operatively connected to first portion 10 . First portion 10 may also have any of a variety of other features and/or components as appropriate for accomplishing the stated purposes of the present invention. For example, first portion 10 may also have a stabilizing handle 30 giving the operator more control over the movement of blender 1 during operation.
[0022] Referring still to FIGS. 1 and 2 , in a first preferred embodiment of the present invention, the one or more handles 22 are preferably at a distal end 28 of the first portion 10 while the at least one first connector 32 is preferably at a proximal end 34 thereof. First connector 32 can have any of a variety of configurations. For example as shown in these figures, first connector 32 can have a mounting hub 36 preferably having one or more prongs or tabs 38 , best shown in FIGS. 1 and 4 , and at least one aperture for accommodating a drive shaft 13 , shown best in FIG. 2 , and/or a motor coupling operatively connected to drive motor 12 .
[0023] Drive shaft 13 , in one aspect of the present invention, can provide or transmit rotational torque generated by drive motor 12 to the third portion 16 indirectly via the one or more rotating shafts 18 . In this aspect of the present invention, drive shaft 13 and/or one or more rotating shafts 18 may be interconnected in any of a variety of conventional ways. For example, as shown in FIG. 3 , a shaft connector 15 , such as a link pin 17 , may be used. Alternatively, in another aspect of the present invention, the drive shaft 13 provide rotational torque to the third portion 16 directly.
[0024] Referring now to FIGS. 3 through 5 , second portion 14 can have an elongate member 40 that is preferably suitable to house or accommodate at least a portion of one or more rotating shafts 18 and/or drive shaft 13 . In addition, second portion 14 may have at least one second connector 42 at a distal end 44 of elongate member 40 and at least one third connector 46 at a proximal end 48 thereof. Preferably, second connector 42 is complementary to first connector 32 . For example, as best shown in FIG. 2 , second connector 42 can have one or more grooves or slots 50 that are suitable to receive and/or engage the one or more tabs 38 of the first connector 32 .
[0025] Thus, in a preferred embodiment of the present invention, first connector 32 and second connector 42 may be securely and reliably connected by engaging tabs 38 with slots 50 and twisting or rotating first connector 32 and second connector 42 with respect to each other to activate a lock/release mechanism. Preferably, a lock/release mechanism (not shown), such as, for example, a detent system or a biased cam system may be used to facilitate locking and/or releasing the connectors 28 , 42 with respect to each other. Alternatively, in another embodiment of the present invention, first connector 32 and second connector 42 may be threadably engaged and/or disengaged as desired. Other rotating connections and/or locking mechanisms may additionally or alternatively be used and fall within the scope of the present invention.
[0026] Thus, although first and second portions 10 , 14 can have any of a variety of different shapes, sizes and/or configurations, and may have any of a number of different elements, connectors 28 , 42 preferably allow the operator to easily disengage or release second portion 14 and first portion 10 for separate cleaning and/or storage.
[0027] In a preferred aspect of the present invention, second connector 42 preferably hermetically seals distal end 44 to preferably prevent moisture and/or any other damaging substances from entering elongate member 40 . This sealing feature may be accomplished in any of a variety of ways. For example, as best shown in FIG. 2 , second connector 42 can have a chamber or pocket 52 suitable to receive and accommodate hub 36 of first connector 32 . Pocket 52 preferably has sidwall 54 and a base 56 . Base 56 is preferably formed of one or more first sealing elements 58 , such as, for example, a bearing member, an oil seal, an o-ring, and/or a retaining member. Sealing elements may also be used. Preferably, first sealing elements 58 can be configured so that the one or more rotating shafts 18 and/or the drive shaft 13 may operatively pass therethrough without compromising the seal.
[0028] Referring to FIGS. 3 and 5 , third portion 16 , can accommodate at least a portion of a processing tool 60 via, for example, a tool guard 62 and/or a tool holder 64 . In addition, third portion 16 can be operatively connected to second portion 14 via third connector 46 of second portion 14 . For example, as best shown in FIG. 2 , third connector 46 can have one or more fasteners 66 that are preferably suitable to securely and reliably connect third portion 16 to the proximal end 48 of elongate member 40 . In another preferred aspect of the present invention, fasteners 66 facilitate the connection of second and third portions 14 , 16 .
[0029] In an alternative embodiment of the invention, fasteners 66 may be constructed so that third portion 16 and second portion 14 can be releasably connected. In this alternative embodiment of the invention, third connector 46 may cooperate with a fourth connector (not shown) in a manner similar to that described above with respect to the connection of first and second connectors 28 , 42 . In addition, other connections and/or locking mechanisms may additionally or alternatively be used, yet still fall within the scope of the present invention.
[0030] Although second and third portions 14 , 16 can have any of a variety of different shapes, sizes and/or configurations, and may have any of a number of different elements, third and/or fourth connectors of this embodiment may allow the operator to conveniently disengage or release the second portion 14 and the third portion 16 from one another for separate cleaning, storage and/or operative uses.
[0031] In another preferred aspect of the present invention, third connector 46 preferably hermetically seals proximal end 48 of elongate member 40 to preferably prevent moisture and/or any other damaging substances from entering elongate member 40 . Also, with respect to the embodiment of the invention in which second and third portions 14 , 16 may be releasably connected, the third and/or fourth connector may preferably be suitable to seal and/or securely hold the various components of third portion 16 as appropriate for convenient cleaning, storage and/or operative use.
[0032] This sealing feature may be accomplished in any of a variety of ways. For example, as best shown in FIGS. 2 and 3 , third connector 46 can cooperate with one or more second sealing elements 68 , such as, for example, a bearing member, an oil seal, a cap element, and/or at least a portion of tool guard 62 or tool holder 64 . Additional or alternative sealing elements may also be used. Preferably, second sealing elements 68 and/or third connector 46 can be constructed so that the one or more rotating shafts 18 may operatively pass therethrough, without compromising the seal, and transmit torque to processing tool 60 .
[0033] Having identified and discussed some of the preferred aspects or embodiments of the present invention, in use, blender 1 may be efficiently and effectively assembled and/or disassembled as desired to allow for convenient cleaning, storage, and/or varied operative uses.
[0034] The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit of the present invention as defined herein.
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There is provided an hand held blender essentially having at least two housing or body portions, a first housing or body portion suitable for containing a drive motor and a second housing or body portion suitable for containing one or more shanks or shafts operatively connected to the drive motor, and a processing tool operatively connected to the one or more shafts. Each of first and second portions has at least one connector suitable to rotatably connect and/or disconnect the at least two portions, as desired, in a reliable and stable manner.
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[0001] This application claims the benefit of Japanese Patent applications No. 2003-039933 and No. 2003-173720 which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a one-way clutch device which is assembled in a starter apparatus, or the like, for an automatic two-wheeled vehicle, and a method for manufacturing the same.
[0004] 2. Related Background Art
[0005] A starter apparatus for an automobile is additionally provided with a one-way clutch device for performing torque transmission from an electric motor side to an internal combustion engine side only, in order to prevent overrun of the electric motor after the internal combustion engine is started. As a one-way clutch device of this type, one type is dominantly used in which clutch elements such as torque transmission rollers, cam surfaces and a spring is interposed between an inner race element and an outer race element, and these clutch elements are accommodated in and retained by a cage which is formed of a steel plate or synthetic resin (see the Japanese Utility Model Registration No. 2574315 (page 3, FIG. 1), the Japanese Patent Publication No. 56-41847 (page 3, FIG. 1), the Japanese Utility Model Publication No. 49-20603 (page 2, FIG. 6) and the Japanese Patent Application Laid-Open No. 11-117955 (page 1, FIG. 2, particularly), for example).
[0006] Also, there is disclosed in the Japanese Patent Application Laid-Open No. 11-117955 a one-way clutch device in which a cage formed of an elastically deformable material comprises a cylindrical portion and a flange, the flange has a plurality of clapper pieces which are elastically deformable and extended substantially in a circumferential direction, and the clapper pieces are inserted in flange receiving grooves formed on the outer race by the use of the elastic deformation of the clapper pieces to be fixed in the axial direction. That is, the flange is provided with a small-diameter portion and the clapper pieces which are extended substantially in the circumferential direction to be elastically deformable formed on the same flat surface thereof. On the outer race, there are formed flange receiving grooves each having the diameter larger than that of the small-diameter portion of the flange and smaller than that of the clapper piece. When each of the clapper pieces is flexed to be moved to the position of the flange receiving groove, the elastically deformable clapper piece is, with the property of returning into its original form, fitted into the flange receiving groove, whereby the one-way clutch is retained at that position in the axial direction.
[0007] The conventional one-way clutch device described above functions well without any trouble in a starter apparatus for a four-wheeled vehicle in which the maximum number of rotation of the internal combustion engine is comparatively low which is, e.g., 6,000 rpm or around. However, when this clutch device is used in a starter apparatus for an automatic two-wheeled vehicle in which the maximum number of rotation of the internal combustion engine is comparatively high which is, e.g., 15,000 rpm or around, such a problem as described below may be brought about. That is, for example, during the operation of the internal combustion engine, a constituent member of the one-way clutch device is affected by the centrifugal force which follows the rotation. In case of an automatic two-wheeled vehicle, the centrifugal force becomes very large due to the high maximum number of rotation, so that coupling columns of the cage are sometimes deformed to spread in the outer diameter direction. Moreover, since the centrifugal force acting on the spring becomes larger in the same manner, the spring may come off the cage so that its function of urging the torque transmission rollers can not be performed.
[0008] There is another fear that the cage and a member and the like assembled in the cage may fall out from the outer race member (outer race element) at the time of conveyance prior to the installation thereof to the main body of the two-wheeled vehicle, an automatic transmission, etc., In the one-way clutch disclosed in the Japanese Patent Application Laid-Open No. 11-117955, the elastically deformable clapper pieces are fitted into the flange receiving groove, with the property of returning into its original form, so that the one-way clutch is retained at that position in the axial direction. For this reason, it is possible to prevent fall out of parts such as a cage. However, the structure disclosed in the Japanese Patent Application Laid-Open No. 11-117955 mainly depends on the elastic deformation of the clapper pieces, which is not always advantageous to prevention of a fall out of the cage or the like parts.
[0009] Further, when the constituent parts of the cage are assembled to complete the cage, the assembling performance of each part is not always satisfactory. For example, when the detention piece is to be fitted in the recess, the detention may be hooked by the recess.
SUMMARY OF THE INVENTION
[0010] The present invention has been contrived taking the situation described above into consideration, and an object of the invention is to provide a one-way clutch device with the intention of improving the strength of the coupling columns, preventing a fall out of a spring, or the like, and further with the intention of preventing a fall out of the cage, or the like, from the outer race in order to improve the assembling performance of each constituent part of the cage, and a method for manufacturing such a one-way clutch device.
[0011] In order to solve the above-described problems, according to a first aspect of the present invention, there is provided a one-way clutch device comprising a plurality of torque transmission members interposed between an inner race element and an outer race element for performing torque transmission between the inner race element and the outer race element only during one-way relative rotation, and a cage having a pair of flanges for holding these torque transmission members therebetween and a plurality of coupling columns for coupling the paired flanges together, wherein the coupling columns of the cage may be fixed to fixing portions provided at least at two positions on the inner peripheral side and the outer peripheral side of the flanges.
[0012] In a first mode of the present invention, in the one-way clutch device according to the first aspect, at least one of the fixing portions may be a hole or a recess, and a caulking portion to be fitted in the hole or recess to be caulked may be formed in an end portion of the coupling column.
[0013] In a second mode of the present invention, in the one-way clutch device of the first mode, at least one of the fixing portions may be a hole or a recess, and a detention portion to be fitted in the hole or recess may be formed in an end portion of the coupling column.
[0014] In a third mode of the present invention, in the one-way clutch device of the second mode, a guide part may be formed on the detention portion for guiding the detention portion to be fitted into the recess or hole.
[0015] In a fourth mode of the present invention, in the one-way clutch device of the third mode, the guide part may be formed by chamfering or beveling the tip end of the detention portion.
[0016] In a fifth mode of the present invention, in the one-way clutch device according to either one of the second to fourth modes, the tip end of the detention portion may be protruded from the flange.
[0017] In a sixth mode of the present invention, in the one-way clutch device of the fifth mode, an amount of projection of the detention portion may be smaller than that of the caulking portion.
[0018] In a seventh mode of the present invention, the one-way clutch device described above may further comprise springs for urging respectively the torque transmission members in the direction of torque transmission, wherein a fixed end of each spring may be held between the flange and the coupling column between the two fixing portions.
[0019] In an eighth mode of present invention, in the one-way clutch device described above, each coupling column may be extended from one of the flanges and may be fixed to the other of the flanges.
[0020] According to a second aspect of the present invention, in one-way clutch device comprising an inner race element, an outer race element disposed to be coaxial and relatively rotatable with this inner race element, a plurality of cam surfaces formed on either one of the outer peripheral surface of the inner race element and the inner peripheral surface of the outer race element, a cylindrical surface formed on the other of the outer peripheral surface of the inner race element and the inner peripheral surface of the outer race element, a plurality of torque transmission rollers interposed between the cam surfaces and the cylindrical surface, springs for urging the respective torque transmission rollers in the direction of torque transmission, and a cage for retaining the torque transmission rollers and the springs, the cage being constituted by two metal plates each in a substantially annular form, a plurality of coupling columns bent up substantially perpendicularly from one of the metal plates being fixed to the other of the metal plates, and the torque transmission rollers and the springs being retained between the adjacent coupling columns, the coupling column may have an outer peripheral portion substantially along the tangential direction of the outer race element, an inner peripheral portion substantially along the tangential direction of the inner race element, and an inclined portion for coupling the outer peripheral portion and the inner peripheral portion together; a connection piece protruded from an end surface of the outer peripheral portion may be fixed to the other of the metal plates; and a detention piece protruded from an end surface of the inner peripheral portion may be fitted in a recess formed on the other of the metal plates.
[0021] In a ninth mode of the present invention, in the one-way clutch device according to the second aspect, the fixing may be fitting of the connection piece in the hole or recess formed on the other of the metal plates to be caulked.
[0022] In a tenth mode of the present invention, in the one-way clutch device according to the second aspect, the fixed end of the spring may be held by and between sid inclined portion and the other of said metal plates.
[0023] In an eleventh mode of the present invention, in the one-way clutch device according to the second aspect comprising outer and inner races which are arranged coaxially and a cage provided with torque transmission members and biasing springs for urging the respective torque transmission members between the outer and inner races, the cage may have a flange which is provided with an engagement projection; and a fit groove into which the engagement projection may be fitted is formed on at least one of the outer and inner races.
[0024] In a twelfth mode of the present invention, in the one-way clutch device of the eleventh mode, a plurality of the engagement projections may be provided on the circumference at regular intervals.
[0025] In a thirteenth mode of the present invention, in the one-way clutch device of the tenth to eleventh modes, the fit grooves may be formed in a substantially annular form.
[0026] In a fourteenth mode of the present invention, in the one-way clutch device according to either one of the tenth to thirteenth mode, the engagement projections may be formed on the outer periphery of the flange and the fit grooves may be formed on the inner periphery of the outer race.
[0027] In a fifteenth mode of the present invention, in the one-way clutch device according to either one of the tenth to fourteenth mode, the inner element or the outer element may be provided with a guide part for guiding the engagement projections to be fitted in the fit grooves when the cage is assembled.
[0028] According to a third aspect of the present invention, there is provided a method for manufacturing a one-way clutch device comprising an inner race element, an outer race element disposed to be coaxial and relatively rotatable with the inner race element, a plurality of cam surfaces formed on either one of the outer peripheral surface of the inner race element and the inner peripheral surface of the outer race element, a cylindrical surface formed on the other of the outer peripheral surface of the inner race element and the inner peripheral surface of the outer race element, a plurality of torque transmission rollers interposed between the cam surfaces and the cylindrical surface, springs for urging the torque transmission rollers in the direction of torque transmission, and a cage for retaining the torque transmission rollers and the springs, the cage being constituted by two metal plates each in a substantially annular form, a plurality of coupling columns bent up substantially perpendicularly from one of the metal plates being fixed to the other of the metal plates, and the torque transmission rollers and the springs being retained between the adjacent coupling columns, which manufacturing method comprising: a step of blanking a first work serving as one of the metal plates from a metal plate material; a step of bending coupling column portions of the first work to have a predetermined cross section; a step of obtaining a first metal plate by bending up the coupling column portions of the first work; a step of blanking the other of the metal plates from a metal plate material together with a fixing hole or recess; a step of attaching an end of each spring to the corresponding coupling column of the first metal plate; and a step of fixing the coupling columns of the first metal plate to the second metal plate.
[0029] In the method for manufacturing a one-way clutch device according to the present invention, the step of fixing the coupling columns of the first metal plate to the second metal plate may be carried out by fitting and caulking a connection piece formed to be protruded on an end portion of each coupling column into the hole or recess.
[0030] In the method for manufacturing a one-way clutch device according to the present invention, the step of fixing the coupling columns of the first metal plate to the second metal plate may be carried out by fitting and fastening a detention piece formed to be protruded at an end portion of each coupling column in the hole or recess.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a front view of a one-way clutch device according to an embodiment of the present invention;
[0032] FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 ;
[0033] FIG. 3 is a front view of a cage according to the first embodiment of the present invention;
[0034] FIG. 4 is an enlarged view of an essential portion of the cage according to the first embodiment of the present invention;
[0035] FIG. 5 is a plan view of an accordion spring;
[0036] FIG. 6 is a front view of a work;
[0037] FIG. 7 is an explanatory view for illuminating a treatment process of the work;
[0038] FIG. 8 is an explanatory view for illuminating the treatment process of the work;
[0039] FIG. 9 is a front view of a second flange;
[0040] FIG. 10 is an explanatory view for illuminating an assembling process of the cage;
[0041] FIG. 11 is an explanatory view for illuminating the assembling process of the cage;
[0042] FIG. 12 is a front view of a one-way clutch device according to a second embodiment of the present invention;
[0043] FIG. 13 is a cross-sectional view taken along line B-B in FIG. 12 ;
[0044] FIG. 14 is a partially exploded front view of the cage shown in FIG. 12 ;
[0045] FIG. 15 is an enlarged view for showing an essential portion of the cage shown in FIG. 12 ;
[0046] FIG. 16 is a developed view of the cage on the first flange side;
[0047] FIG. 17 is a front view of the cage on the second flange side;
[0048] FIG. 18 is a plan view of an urging spring (accordion spring);
[0049] FIG. 19 is an enlarged cross-sectional view of a portion C in FIG. 13 ;
[0050] FIG. 20 is an enlarged view for showing a detention piece and a detention portion of a recess, seen from the inner diameter side outwardly in the radial direction; and
[0051] FIG. 21 is an enlarged view for showing the detention piece and the detention portion of the recess, seen from the front.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] The present invention will be specifically described below with reference to the drawings.
[heading-0053] (First Embodiment)
[0054] FIG. 1 is a front view for showing a first embodiment of a one-way clutch device according to the present invention, and FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 . Also, FIG. 3 is a front view of a cage, and FIG. 4 is an enlarged view of an essential portion of the cage.
[0055] As shown in FIG. 1 and FIG. 2 , the one-way clutch device 1 of the present invention is comprised of an inner race member (inner race element) 3 , an outer race member (outer race element) 7 which is disposed coaxially with and relatively rotatable with respect to the inner race member 3 and is provided with a plurality of cam surfaces 5 (six in the present embodiment) formed on the inner periphery thereof, a plurality of torque transmission rollers 9 (six in the present embodiment) which are interposed between the inner race member 3 and the outer race member 7 , accordion springs 11 for urging respectively the torque transmission rollers 9 in the direction of torque transmission, and a cage 13 formed of a steel plate.
[0056] In case of the present embodiment, the inner race ember 3 is coupled to a start motor which is not shown in the drawing while the outer race member 7 is coupled to a generator which is not shown in the drawing. A tapped hole 15 is formed on the outer race member 7 to be used to fasten the outer race member 7 with the generator.
[0057] As shown in FIG. 3 and FIG. 4 , the cage 13 is comprised of a first flange (one of metal plates) 21 and a second flange (the other of the metal plates) 23 assembled therein. The both flanges are formed of steel plates by pressing. The accordion springs 11 are retained by the respective coupling columns 25 extended from the first flange 21 and by the second flange 23 .
[0058] Each coupling column 25 comprises an outer peripheral portion 27 extended substantially along the tangential direction of the outer race member 7 , an inner peripheral portion 29 substantially along the tangential direction of the inner race member 4 , and an inclined portion 31 for coupling the outer peripheral portion 27 and the inner peripheral portion 29 together. Then, connection pieces 33 protruded from an axial end surface of the outer peripheral portion 27 are fitted in the respective through holes 35 formed on the second flange 23 and caulked thereon, and detention pieces 37 protruded from an axial end surface of the inner peripheral portion 29 is fitted in the respective recesses 39 formed on the second flange 23 to be detained.
[0059] As shown in FIG. 5 , each accordion spring 11 comprises a pressing portion 41 for urging the corresponding torque transmission roller 9 and a fixed end 43 which is retained by the corresponding coupling column 25 . The fixed end 43 of each accordion spring 11 is held by and between the inclined portion 31 and the second flange 23 , so as to prevent the accordion spring 11 from falling out in the radial direction by the connection pieces 33 and the detention pieces 37 .
[0060] Description will be made below on a method for manufacturing the one-way clutch device of the present embodiment.
[0061] A manufacturer blanks a work 51 shown in FIG. 6 from a steel plate material by the use of a pressing machine. The work 51 is constituted by six coupling column portions 55 which serve as coupling columns 25 formed on the outer peripheral side of a flange portion 53 serving as the first flange portion 21 .
[0062] Upon completion of the blanking of the work 51 , the manufacturer executes a bending process on the coupling column portions 55 by the use of the pressing machine, as shown in FIG. 7 , thereby forming the inclined portions 31 , each coupling the outer peripheral portion 27 and the inner peripheral portion 29 together. The connection piece 33 is formed to be protruded from an end of the outer peripheral portion 27 , and the detention piece 37 is protruded from an end of the inner peripheral portion 29 . The manufacturer then bends up the coupling column portions 55 by the pressing machine, thereby completing the first flange 21 having the coupling columns 25 perpendicularly thereto.
[0063] On the other hand, the manufacturer blanks the second flange 23 shown in FIG. 9 from the steel plate material by the use of a pressing machine. The second flange 23 is formed with six through holes 35 and twelve recesses 39 on the inner peripheral end thereof.
[0064] Upon completion of the first flange 21 and the second flange 23 , the manufacturer fits the connection pieces 33 of the coupling columns 25 into the respective through holes 35 of the second flange 23 and the detection pieces 37 into the respective recesses 39 in a state that the fixed end 43 of each accordion spring 11 has been inserted on the corresponding inclined portion 31 of the coupling column 25 , as shown in FIG. 10 . After that, as shown in FIG. 11 , the manufacturer caulks the connection pieces 33 protruded through the respective through holes 35 to thereby complete the cage 13 . In the present embodiment, since there are arranged twelve recesses 39 , the directionality (either the surface or the back) of the second flange 23 disappears so as to make the assembling work easier.
[0065] Upon completion of the cage 13 , the manufacturer assembles the torque transmission rollers 9 in the cage 13 and then installs the cage 13 between the inner race member 3 and the outer race member 7 , thereby completing the manufacturing process.
[0066] The coupling columns 25 of the cage 13 in the present embodiment, each has a substantially Z-shaped cross section consisting of the outer peripheral portion 27 , the inner peripheral portion 29 and the inclined portion 31 , so that the strength and the rigidity thereof become very high. For this reason, there is no fear that the coupling column 25 may be deformed by the centrifugal force even when the one-way clutch device is used for an automatic two-wheeled vehicle. Also, since the fixed end 43 of each accordion spring 11 is held or sandwiched by and between the inclined portion 31 and the second flange 23 and further the accordion spring 11 is prevented from falling out in the radial direction by the connection piece 33 and the detention piece 37 , there is no fear at all that the accordion spring 11 may fall out by the centrifugal force.
[heading-0067] (Second Embodiment)
[0068] FIG. 12 is a front view of a one-way clutch device according to a second embodiment of the present invention, FIG. 13 is a cross-sectional view taken along line B-B in FIG. 12 , and FIG. 14 is a partially exploded front view of the cage shown in FIG. 12 . FIG. 15 is an enlarged view for showing an essential portion of the cage shown in FIG. 12 .
[0069] FIG. 16 is a developed view of the cage on the first flange side. FIG. 17 is a front view of the cage on the second flange side. FIG. 18 is a plan view of an urging spring which is an accordion spring.
[0070] FIG. 19 is an enlarged cross-sectional view of the portion C in FIG. 13 . FIG. 20 is an enlarged view for showing a detention piece and a detention portion of a recess, seen from the inner diameter side outwardly in the radial direction. FIG. 21 is an enlarged view for showing the detention piece and the detention portion of the recess, seen from the front.
[0071] The second embodiment is obtained by improving the first embodiment described above, and description of the arrangements and effects common to the both embodiments will be omitted. Only different points will be described.
[0072] In the first embodiment described above, it is feared that, during conveyance preceding to the assembling in the main body of a two-wheeled vehicle, an automatic transmission, or the like, the cage 13 , constituent parts assembled in the cage 13 , or the like, may drop out from the outer race member 7 .
[0073] For such a reason, in the second embodiment, as shown in the portion C in FIG. 13 and in FIG. 19 , a circumferential fit groove 60 which is substantially annular and narrow is provided on the inner peripheral end edge of the outer race member 7 .
[0074] On the other hand, as shown in FIG. 14 and FIG. 17 , a plurality of engagement projections 61 are formed on the outer peripheral end edge of the second flange 23 of the cage 13 , each to be fitted in fit groove 60 and engaged therewith.
[0075] As shown in FIG. 19 , it is arranged such that, when the cage 13 is attached to the outer race member 7 for assembling, that is, when the second flange 23 is inserted in the axial direction, these plurality of engagement projections 61 are fitted in the fit groove 60 (circumferential groove) and are engaged therewith.
[0076] Note that, when this fitting is carried out, the second flange 23 is slightly flexed. Also, as shown in FIG. 19 , a chamfered or beveled portion 62 serving as a guide part is formed on the inner peripheral end surface of the outer race member 7 in such a manner that, when the second flange 23 is inserted in the axial direction, the engagement projections 61 are smoothly moved on the inner peripheral end surface of the outer race member 7 to be guided into the circumferential fit groove 60 .
[0077] As described above, since the plurality of engagement projections 61 are fitted in the circumferential groove 60 , it is possible to restrict a movement of the cage 13 in the axial direction by detaining the cage 13 at that position in the axial direction. Also, since the second flange 23 and the engagement projections 61 are elastically deformed comparatively less, compared with structure disclosed in the Japanese Patent Application Laid-Open No. 11-117955, the cage 13 can be detained at that position in the axial direction without fail, and consequently, the cage 13 , or the like, can be prevented from getting out of the outer race member 7 .
[0078] Also, in the first embodiment described above, when the cage 13 is completed by assembling all the constituent parts of the case 13 , there is a probability that the assembling performance of each part is not always satisfactory so that the detention piece 37 is, for example, when it is to be fitted in the recess 39 , caught or hooked by the recess 39 without being fitted therein.
[0079] In order to prevent such a trouble, in the second embodiment, a chamfered or beveled portion 70 serving as a guide for guiding the detention piece 37 to be fitted into the recess 39 is provided in the tip end portion of the detention piece 37 .
[0080] With such an arrangement, the tip end portion of the detention piece 37 can be fitted in the recess 39 easily and the detention piece 37 can be prevented from being hooked or caught by the recess 39 , whereby the assembling performance of each part of the cage can be remarkably improved.
[0081] The guide part 70 described above is formed by chamfering or beveling the tip end portion of the detention piece 37 . However, it is possible to provide any other contrivance, and the guide part may be in an inclined, arcuate, or any other form so long as the tip end portion is not hooked nor caught by the end surface of the recess 39 . Also, it is possible to obtain the same effect by properly altering the surface roughness, or the like, of the guide part. Further, it is possible to prevent the tip end portion from being hooked or caught by the end surface of the recess 39 by properly setting a detention space between the detention piece 37 and the recess 39 .
[0082] Also, as shown in FIG. 15 and FIG. 20 , each detention piece 37 is slightly protruded from the second flange 23 . An amount of this projection is made smaller than that of the connection piece 33 (the caulking portion or the thick plate portion), as shown in FIG. 15 . With such an arrangement, it is possible to securely attain a sufficient engagement or abutment between the detention piece 37 and the recess 39 .
[0083] Note that the assembling performance may be improved by disposing this chamfered or beveled guide part 70 on the recess 39 of the second flange 23 . In this case, however, the degree of engagement between the recess 39 and the detention piece 37 becomes lower unless the detention piece 37 takes a form in compliance with the guide part 70 . Thus, the working process becomes complicated correspondingly. As a result, the method illustrated in the respective drawings above is superior in terms of the productivity.
[0084] The specific embodiments of the present invention are as described above. However, the present invention is not limited to these embodiments. For example, in the foregoing embodiments, the present invention is applied to the one-way clutch device of a roller type which has cam surfaces on the outer race member. However, the present invention can be applied to a one-way clutch device which has cam surfaces on the inner race member, or has steel balls as the torque transmission members, instead of the torque transmission rollers. In addition, a metal plate other than a steel plate such as a brass plate may be used for the first flange and the second flange. Further, the number of the torque transmission members, the specific forms of the first and second flanges, the entire structure of the one-way clutch device, etc., may be properly altered within the scope and spirit of the present invention.
[0085] According to the one-way clutch device of the present invention, the strength and the rigidity of the coupling columns of the case become very high, so that the coupling columns are not likely to be deformed due to the centrifugal force even when the one-way clutch device is used in an automatic two-wheeled vehicle. On the other hand, the accordion spring is, since being securely retained by the coupling column and the second flange at the fixed end thereof, also not likely to fall out due to the centrifugal force. Thus, the one-way clutch device can maintain the stable function even if it is used for a long term.
[0086] It is also possible to prevent the cage, or the like, from falling out of the outer race, and moreover, the assembling performance of each constituent part of the cage can be improved.
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A one-way clutch device comprises a plurality of torque transmission members interposed between an inner race element and an outer race element for performing torque transmission therebetween only during one-way relative rotation. A cage has a pair of flanges for holding the torque transmission members therebetween and a plurality of coupling columns for coupling the paired flanges together. The coupling columns of the cage are fixed to fixing portions provided on an inner peripheral side and an outer peripheral side of the flanges.
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This is a division of application Ser. No. 866,928, filed Jan. 4, 1978.
BACKGROUND OF THE INVENTION
In the food processing industry the trend is to replace metal cans with something more convenient and more efficient. To that end, retort pouches have been conceived.
A typical retort pouch is made of face-to-face laminate structures which are sealed together on three sides before filling, and they are sealed on the fourth side after filling. The sealed retort pouches usually are heated or retorted after final sealing to cook the contents of the pouch and to kill all bacteria within the pouch.
To laminate structures, typically, comprise an aluminum foil with a polyester adhesively attached to one side thereof, frequently by means of a polyester urethane adhesive, and a sealable lamina attached to the second side of the foil.
If all that was desired was the structuring of a pouch, the sealable lamina of the aluminum foil could also be attached in the same manner as the polyester lamina. However, polyester urethanes have not been approved by governmental authorities because of possible contamination of the contained food. Therefore, for retort pouches for enclosing food, a maleic anhydride polymer grafted onto polypropylene is coated on the second surface of the aluminum foil, and then it is heat-cured in line with coating operation. Such materials are known by the trade names Hercoprime and Morprime. An inner sealant layer of polypropylene is then attached onto the maleic anhydride polymer grafted onto polypropylene at high temperatures on the order of 500° Fahrenheit. Unfortunately, the high temperature heating of the sealant layer of polypropylene appears to oxidize the surface of the polypropylene thereby increasing the difficulty of sealing the laminate structures together to form the pouch.
BRIEF DESCRIPTION OF THE INVENTION
To enhance the structural integrity of the laminate and pouches made therefrom, in accordance with this invention, a separate layer of polypropylene is extruded into a combining nip as an adhesive between a previously cast sealant layer of polypropylene and the cured layer of maleic anhydride polymer grafted on polypropylene. In this process an extrusion coating die is positioned as close as practical to the nip and extrudes a sheet of polypropylene between those two layers. One of the rolls forming the nip is chilled to cool the laminate.
It is therefore an object of this invention to provide a process for making laminate structures suitable for use in retort pouches.
It is a further object to this invention to provide such a laminate structure.
It is a further object to this invention to provide a novel retort pouch.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects will become apparent from the following description, taken together with the accompanying drawings, in which:
FIG. 1 shows a retort pouch sealed around three edges and ready for filling;
FIG. 2 is a diagram, with thicknesses exaggerated, of a laminate structure in accordance with this invention;
FIG. 3 shows the laminate of this invention being assembled.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a retort pouch having substantially similar front and back walls 22 and 24 sealed together on three edges 26, 28, and 30, and open on the fourth edge to receive food.
Food is placed in the pouch, the fourth edge sealed, and the entire pouch with the food therein is heated or retorted.
The novel laminate structure used for each of the side walls 22 and 24 is shown in FIG. 2. The inside or sealant lamina is the layer that contacts the food. The sealant layer 10 is attached by the layer 12 to the primer layer 14 on the aluminum or other metal foil stock 16. On the outside a biaxially oriented polyester layer 20 is attached by an adhesive 18 to the foil 16. The layer 20 physically protects the foil from being penetrated or otherwise physically damaged.
The sealing layer 10 contains polypropylene, and it may contain either polyethylene or ethylene vinyl acetate copolymer, or both. The polyethylene and/or ethylene vinyl acetate copolymer may be used either as a blend or as a copolymer/terpolymer with the polypropylene. Typically a terpolymer of propylene, ethylene, and vinyl acetate, film grade resin, with a melt flow index of about 10 and having a thickness between 11/2 and 6 mils is used.
The lamina 12 is an extrusion grade polypropylene or polypropylene copolymer or polypropylene polyethylene blend. One acceptable material is sold under the trade name of Eastman 4G7DP. The layer 12 is inserted into the laminate as shown in FIG. 3. A storage tank or hopper 38 contains the pelletized material which is extruded through the extrusion die into a sheet 12. The sheet 12 is drawn into the nip between the lamina 10 and the cured lamina 14 at a temperature on the order of between 540° and 640° Fahrenheit. Either roller 32 or 34 is a temperature contolled roller whose best temperatures are between 155° and 160° Fahrenheit, although as low as 50° Fahrenheit and as high as 250° Fahrenheit are acceptable. The other roller 32 or 34 may be used with or without direct temperature control.
The extruded resin sheet 12 may also contain ethylene vinyl acetate either as a copolymer or a blend. Typically the resin melt flow is between 25 and 90 with a typical value of 60.
The lamina 14 between the foil 16 and the layer 12 is formed from a suspension or dispersion of polymer in a liquid. The polymer is a graft copolymer of maleic anhydride onto a propylene backbone; a typical copolymer is sold under the trademark Hercoprime. Also about 3% of an ethylene vinyl acetate copolymer may be used. The liquid is a mixture of methyl cellosolve; toluene; deodorized kerosene; and Varnish Makers & Painters naphta sold under the trade mark of Naphtholite by Union Oil Co. is a petroleum naphtha having a narrow boiling range near 253° F. and is described on page 1,576 in the 1976 edition of McGraw Hill Dictionary of Scientific and Technical terms. The polymer suspension is sold under the trade name of Morprime. Although the exact nature of the lamina bonding is not clearly known it is believed the maleic anhydride bonds chemically to metal foil 16, and the polypropylene bonds to layer 12.
The aluminum foil layer 16 may be between 1/4 mil and 5 mils in thickness. The outer lamina 20 is preferably 0.48 mil mylar, but its thickness range may be between 1/4 mil and 2 mils in thickness. The lamina 20 may be any material which protects the foil layer 16 from physical damage. It is typically either biaxially oriented polyester such as mylar, or it is a polyamid such as nylon. The mylar or laminate 20 is attached to the outside of the foil 16 by an adhesive layer 18 which may be a two component polyester urethane adhesive. Examples of appropriate adhesive are sold under the trade names of Desoto EPS-71 and Morton Adcote 506. The layers 14, 16, 18, and 20 are assembled together and heat cured. As shown in FIG. 3, that heat cured laminate structure and the sealant lamina 10 are pulled by the nip formed by the rolls 32 and 34 into that nip. The extrusion die 36 feeds a sheet of laminar material 12 directly into the nip between laminae 10 and 14. The distance between the die 36 and the nip is adjustable to obtain optimum adhesion among laminae 10, 12 and 14. Before bonding the sheet 10 may be surface treated in an ionized electric field.
After the finished laminate structure is completed, it is cut to size and sealed on three edges 26, 28 and 30 as shown in FIG. 1. Because the material in face to face contact in layers 10 is not oxidized, the layers form adequate and uniform seals on production equipment.
Thus, the invention herein described is a new laminate structure together with the process for making such a structure, and the laminate structure is particularly useful in the making of retort pouches which contain a food or other such material.
Obviously the retort pouch could be used for the carrying of other items needing hermeticseals such as antiseptic bandages, other medical materials, and hard to hold chemically active products.
Although the invention has been described in detail above, it is not intended that the invention should be limited by that description, but only by the combined description set forth in the specification and the claims.
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A hermetically sealed pouch, being safe for the storage of foods, avoiding giving a taste to enclosed food, the filled pouch being able to withstand cooking temperatures typically used to cook food.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/925,457 filed Apr. 19, 2007, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to an apparatus and method for the treatment of fractures of the proximal femur including the neck of the femur and the intertrochantric region.
[0004] 2. Brief Description of the Prior Art
[0005] In treatment of the fracture of the femoral neck it is necessary to maintain angular stability of the head fragment to maintain an anatomical reduction postoperatively. It is also desirable to compress fracture site intra-operatively and then to stabilize the bone fragments by not allowing any further axial or angular movement. Since axial movement of the bone fragment resulting in shortening of the neck of the femur will result in reduced physical functioning, particularly in younger patients, it is desirable to stabilize the fracture postoperatively.
[0006] Many locking plates are available that allow stabilization of bone fragments. Conventional locking plates (also known as bone plates) have a plate that is attached to the fragments of the fractured bone via screws that are inserted in the bone through screw holes in the plate. The screws of the conventional locking plates have threads on the head portion in addition to the threads on the shaft. The threads on the head portion have a greater core diameter than the threads on the shaft but both threads have same pitch. When the screw is advanced in the bone and the head of the screw is in the screw hole of the bone plate, the threads on the screw head engage matching threads in the screw hole. This locks the screw in place and prevents it from moving in the axial direction post operatively. However, such bone plate system cannot be used to compress the fracture site. In another conventional bone plate system used for femoral neck fracture a compression screw is used. The compression screw head does not have the threads and therefore may be rotated further after its head has reached the final axial position thereby compressing the fracture site. A separate end cap is then screwed in the compression screw hole of the bone plate to prevent the screw from moving back in the axial direction.
[0007] These bone plate systems require a separate step of installing an end cap to prevent post operative axial movement of the screw. Therefore, there is a need for further improvement in bone plate systems to provide an easy to use plate system that facilitates intra-operative compression and at the same time provides angular and axial stability post operatively.
[0008] As used herein, when referring to bones or other parts of the body, the term “proximal” means closer to the heart and the term “distal” means more distant from the heart. The term “inferior” means toward the feet and the term “superior” means towards the head. The term “anterior” means towards the front part of the body or the face and the term “posterior” means towards the back of the body. The term “medial” means toward the midline of the body and the term “lateral” means away from the midline of the body.
SUMMARY OF THE INVENTION
[0009] The present invention provides a bone plate for use with fractures of the femur. Screws attach the bone plate to the femur. The compression screws that are inserted in the neck of the femur may be parallel to the axis of the neck of the femur. Inserting the bone screws in the neck region of the femur provides compression and angular and rotational stability to the head of the femur. Cortical interlocking type screws may be used in a distal portion of the bone plate in the subtrochantric shaft region of the femur. The compression screws stabilize bone fragments when used with end caps and prevent the shortening of the femoral neck resulting in improved postoperative function of the hip. The end cap may be inserted in a threaded plate hole and contact the top of each screw. A polymer buffer may be placed in the screw hole between the end cap and the head of the compression screw. The polymer buffer may allow small movement of the screw.
[0010] In use, the compression bone screw is inserted in the screw hole and screwed into the neck of the femur until the underside of the bone screw sits on the flat face formed in screw hole. Next, the screw is rotated further to apply compression to the fracture site. Once the desired amount of compression is applied, the end cap is inserted in screw hole. The end cap prevents the screw from moving back in the axial direction.
[0011] In another embodiment, a compression screw having a different head design is used with a split locking ring. The locking ring has a smooth circular outer surface that fits in the screw hole. The inner surface of the locking ring has a saw blade like or similarly functioning geometry. The saw blade geometry on the inner surface is preferably asymmetric. The compression screw head has a saw blade geometry that can mate with the saw blade geometry on the inner surface of the locking ring.
[0012] In use, the screw and the split locking ring are assembled together and inserted into the screw hole. The assembly of the screw and the locking ring is then screwed into the bone using a dedicated insertion instrument that holds and rotates the screw and the locking ring simultaneously. When the head of the screw reaches the terminal axial position in the screw hole, both the screw and the locking ring can be rotated further to apply compression to the fracture site. After the compression is applied, the screw alone is turned. The locking ring is thereby clamped between the head of screw and the bone plate. This results in fixing the screw in place such that the screw can not back out in axial direction.
[0013] In yet another embodiment, a compression screw having a different head design is used with a locking ring. The locking ring has a threaded circular outer surface that fits in the screw hole. The top wall of the locking ring projects towards the center of the screw hole and has a hexagonal internal periphery. The bottom surface of the top wall has ridges. The screw has a head that has an outer peripheral surface that slidably fits into the locking ring. The top surface of the head of the screw has depressions that correspond to the ridges. Thus, when the screw is assembled in locking ring, the ridges sit in the depressions. The top surface of the screw head also has a hexagonal depression to allow engagement of a suitable screw driver.
[0014] In use, the compression screw and the locking ring are assembled together and inserted into the screw hole. The assembly of the screw and the locking ring is then screwed into the bone using a dedicated insertion instrument that holds and rotates the screw and the locking ring simultaneously. When the head of the screw reaches the terminal axial position in the screw hole, the screw can be rotated further to apply compression to the fracture site. When the screw is rotated further the ridges loose contact with the depressions. This forms a small gap of approximately 0.1-0.4 millimeters between the screw and the locking ring. As soon as the body weight is applied post-operatively, the femoral head fracture fragment presses the screw back to the lateral side until the movement is stopped by the locking ring. The polymer buffer may also be used with any of the above described embodiments.
[0015] In one aspect the present invention provides a bone plating system having a bone plate having a plurality of openings. The system includes at least one bone screw for insertion in the opening and into a bone and having a head. Depressions are formed on a top surface of the head, and a locking ring adapted to attach to the head and having ridges that have shape complimentary to the depressions is provided. The locking ring fits in the depressions when the locking ring is attached to the head. The locking ring and the bone screw are assembly together and simultaneously inserted in the opening using a dedicated instrument.
[0016] In another aspect, a bone plating system includes a bone plate having a plurality of openings. The system also has at least one bone screw capable of being received through the opening and into a bone. The head of the bone screw has an asymmetric saw blade geometry formed on the periphery. A locking ring having an asymmetric saw blade geometry matching the asymmetric saw blade geometry formed on the periphery of the head is provided. The locking ring and the bone screw are assembly together such that the saw blade geometry on the locking ring is in engagement with the saw blade geometry on the head, and the assembly is inserted in the opening using a dedicated instrument.
[0017] In yet another aspect, a bone plating system includes a bone plate having a plurality of openings and at least one bone screw capable of being received through the opening and into a bone. The bone screw having a head adapted for fitting in the opening when the bone screw is fully inserted in the bone, the head of the bone screw and the opening in the bone plate having complementary shape such that the bone screw when seated in the opening has angular stability. At least one end cap is fixedly inserted in the opening, and a layer of polymeric material is interposed between the end cap and the top of the head such that the compression of the polymeric material would allow slight axial movement of the screw.
[0018] In yet another aspect, a method of fusing fractures of femoral neck using a bone plate is disclosed. The method includes placing a bone plate on the femur, and inserting an assembly of a bone screw and a locking ring in an opening in the plate. Thereafter, simultaneously threading the locking ring and the bone screw in the femur and further threading the bone screw in the femur to compress the fracture. A space is created between the locking ring and the bone screw allowing the bone screw to move towards the locking ring when the joint is loaded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an anterior elevation view of a bone plate mounted on a femur.
[0020] FIG. 1A shows another embodiment of a bone plate that may be mounted on the femur.
[0021] FIG. 2 shows an isometric sectional view of a screw hole in the bone plate of FIG. 1 with a bone screw and an end cap inserted therein.
[0022] FIG. 3 is an isometric view of a first locking ring embodiment.
[0023] FIG. 4 shows a sectional view of the bone plate of FIG. 1 with a locking ring and a screw installed therein.
[0024] FIG. 5 is a lateral view of a portion of a bone plate assembly showing the bone plate, a screw and the locking ring of FIG. 3 .
[0025] FIG. 6 is a sectional view of the bone plate of FIG. 1 with a second embodiment of a locking ring and a screw installed therein.
[0026] FIG. 7 is another sectional view of the embodiment of FIG. 6 .
DETAILED DESCRIPTION
[0027] FIG. 1 shows a bone plate 20 mounted on a femur 22 . Any one of the compression screws disclosed hereafter may be used with the bone plate 20 . In FIG. 1 , compression screws 24 A attach the bone plate 20 to the head 33 and neck 31 of femur 22 . Screws 24 A may be used to attach bone plate 20 to the femur via screw holes 26 in plate 20 . Cortical screws 25 may be used to attach a distal portion 27 of bone plate 20 to the subtrochantric shaft of the femur 22 . In the preferred embodiment these are locking screws. The compression screw 24 A may provide angular and axial stability to the fractured bone pieces. The compression screws 24 A may be cannulated or non-cannulated. The compression screws 24 A may also provide rotational stability. Rotational stability may be achieved by inserting at least two compression screws 24 A through the screw holes 26 and into the neck 31 of the femur 22 . The compression screws 24 A that are inserted in the neck 31 of the femur 22 may be parallel to the axis of the neck 31 of the femur 22 . Cortical interlocking type screws 25 may be used in plate holes 29 in the subtrochantric shaft region of the femur 22 . The cortical interlocking screws 25 may have threads (not seen in the figures) on the periphery of the head portion for engaging threads in hole 29 . The cortical interlocking type screws 25 may be used to prevent the backout of the screws 25 and the bone plate 20 . The compression screws 24 A stabilize the neck fracture head fragment and thereby prevent the shortening of the femoral neck 31 resulting in improved postoperative function of the hip. FIG. 1A shows a plate 20 A. Plate 20 A is a variation of design of plate 20 , and includes a slot 21 . A guide wire may be inserted through slot 21 and into the head 33 of femur 22 . The guide wire may be used to position the plate 20 A in a desired alignment on the surface of the femur 22 . Any one of the compression screws disclosed hereafter may be used with the bone plate 20 A.
[0028] FIG. 2 shows the screw hole 26 in the bone plate 20 with bone compression screw 24 and an end cap 28 inserted in the screw hole 26 . The bone compression screw 24 may be a cannulated screw. However, non-cannulated screws may also be used. In a preferred embodiment, the screw hole 26 has a first threaded section 30 having a larger diameter and a second section 32 having a smaller diameter. A flat face 34 is formed at the junction of the first threaded section 30 and the second section 32 . Threads (not seen in the figures) may be formed on all or portion of the inner periphery of the first threaded section 30 . Inserting one bone compression screw 24 in the neck region of the femur 22 provides angular stability to the head 33 of the femur 22 . One or two or three or more bone compression screws 24 may be inserted in the neck region of the femur 22 . Inserting more than one bone compression screw 24 provides rotational stability to the head 33 of the femur 22 . An end cap 40 may be inserted in screw hole 26 on top of each compression screw 24 . A polymer buffer 44 may be placed in the screw hole 26 between the end cap 40 and the head of the compression screw 24 . The polymer buffer 44 may allow small movement of the compression screw 24 .
[0029] In use, the bone compression screw 24 is inserted in the screw hole 26 and screwed into the neck 31 of the femur 22 until the underside of the bone compression screw 24 sits on the flat face 34 formed in screw hole 26 . Next, the compression screw 24 is rotated further to apply compression to the fracture site. Once desired amount of compression is applied, the end cap 40 is inserted in screw hole 26 . End cap 40 has threads (not seen in the figures) on its periphery that mate with the threads in the screw hole 26 . End cap 40 is screwed into the screw hole 26 till its bottom is on top of the top surface of the head of the compression screw 24 that was previously installed in that screw hole 26 . Thus, the end cap 40 prevents the compression screw 24 from moving back in the axial direction. Optionally, the polymer buffer 44 may be placed over the compression screw 24 prior to installing the end cap 40 . Cortical bone screw 25 are also installed in screw holes 29 and screwed into the subtrochantric shaft region of the femur 22 . The screws 24 and 25 stabilize the bone fracture. The end cap 40 and the bone plate 20 also provide angular stability.
[0030] In another embodiment a compression screw 50 of a different head design is used with a split locking ring 52 . FIG. 3 shows the locking ring 52 . FIG. 4 shows a cross sectional view of the bone plate 20 with the locking ring 52 and the compression screw 50 installed therein. FIG. 5 is a top view of a portion of a bone plate assembly showing the bone plate 20 , the compression screw 50 and the locking ring 52 . The locking ring 52 has a smooth circular outer surface 54 that fits in the screw hole 26 . The inner surface 56 of the locking ring 52 has a saw blade like geometry. The saw blade geometry on the inner surface 56 is asymmetric. The compression screw 50 has a head 58 that has an outer peripheral surface 60 with a saw blade geometry that can mate with the saw blade geometry on the inner surface 56 of the locking ring 52 . The top surface 62 of the screw head 58 has a hexagonal depression to allow engagement of a suitable screw driver. Other known shapes for the depression and corresponding screwdriver may also be used.
[0031] In use, the compression screw 50 and the split locking ring 52 are assembled together and inserted into the screw hole 26 . The assembly of the compression screw 50 and the locking ring 52 is then screwed into the bone using a dedicated insertion instrument that holds and rotates the compression screw 50 and the locking ring 52 simultaneously. When the head of the compression screw 50 reaches the terminal axial position in the screw hole 26 , both the compression screw 50 and the locking ring 52 can be rotated further to apply compression to the fracture site. After the compression is applied, the compression screw 50 alone is turned. This makes the compression screw 50 rotate in relation to locking ring 52 which results in partial disengagement of saw blade geometry on the inner surface 56 of the locking ring 52 from the saw blade geometry on the outer peripheral surface 60 . Since the saw blade geometries on both these surfaces are asymmetrical, the disengagement results in spreading of the locking ring 52 . The locking ring 52 is thereby clamped between the head of compression screw 50 and the bone plate 20 . This results in fixing the compression screw 50 in place such that the compression screw 50 can not back out in axial direction. To remove the compression screw 50 , compression screw 50 is rotated in the opposite direction. This results in the engagement of the saw blade geometries on the on the inner surface 56 of the locking ring 52 and the outer peripheral surface 60 . Next, the compression screw 50 and the locking ring 52 may be removed simultaneously using the dedicated instrument.
[0032] In yet another embodiment a compression screw 70 of a different design is used with a locking ring 72 . FIGS. 6 and 7 show the bone plate 20 , compression screw 70 and the locking ring 72 assembled together. The locking ring 72 has a threaded circular outer surface 74 that fits in the screw hole 26 . The top wall 76 of the locking ring 72 projects towards the center of the screw hole 26 and has a hexagonal internal periphery. The bottom surface 78 of the top wall 76 has ridges 80 . The compression screw 70 has a head 82 that has an outer peripheral surface 84 that slidably fits into the locking ring 72 . The top surface 86 of the head of the compression screw 70 has depressions 87 that correspond to the ridges 80 . Thus, when the compression screw 70 is assembled in locking ring 72 , the ridges 80 sit in the depressions 87 . The top surface 86 of the screw head 82 also has a hexagonal depression to allow engagement of a suitable screw driver. Other known shapes for the depression and corresponding screwdriver may also be used. The external surface of the locking ring 72 may have threads (not seen in the figures) that engage threads in the screw hole 26 .
[0033] In use, the compression screw 70 and the locking ring 72 are assembled together and inserted into the screw hole 26 . The assembly of the compression screw 70 and the locking ring 72 is then screwed into the bone using a dedicated insertion instrument that holds and rotates the compression screw 70 and the locking ring 72 simultaneously. When the head of the compression screw 70 reaches the terminal axial position in the screw hole 26 , the compression screw 70 can be rotated further to apply compression to the fracture site. When the compression screw 70 is rotated further the ridges 80 loose contact with the depressions 87 . This forms, for example, a small gap of approximately 0.1-0.4 millimeter between the compression screw 70 and the locking ring 72 . As soon as the body weight is applied post-operatively, the femoral head fracture fragment presses the compression screw 70 back to the lateral side until the movement is stopped by the locking ring 72 .
[0034] To remove the compression screw 70 , compression screw 70 is rotated in the opposite direction. This results in the engagement of the ridges 80 in the depressions 87 . Next the compression screw 70 and the locking ring 72 may be removed simultaneously using the dedicated instrument.
[0035] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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A bone plate having a plurality of openings for receiving a compression bone screw or a cortical screw. An end cap, threadably insertable in the opening and having a layer of polymeric material interposed between the end cap and the top of the head such that the compression of the polymeric material would allow slight axial movement of the screw. Alternatively, a locking ring adapted to attach to the head of the screw and having shape complimentary to the features formed on the head. The locking ring and the bone screw being assembled together and being insertable in the bone simultaneously using a dedicated instrument. Compression may be applied to a bone fracture by turning the bone screw alone after the locking ring has reached its final axial position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a merchandise display in the form of a box-like rack with a security lock for retaining articles, of merchandise against unauthorized removal, the display being particularly useful for but not limited to use with fishing reels.
2. Description of the Prior Art
It has heretofore been proposed, as in the U.S. Patent to MacMillan, No. 867,966, to provide a lockable display stand of tubular material with struck out hook portions to engage articles to be displayed and with an internally disposed keeper rod, capable of being locked in secured position, and engaging an article in or on the struck out hook portion. The struck out portions, unless of very heavy material, could be bent with a screw driver or the like to release the article in spite of the engagement by the keeper. This structure, also, is limited as to the character of articles to be supported, by the necessity for carrying the article on the hook.
It has also heretofore been proposed, as in the U.S. Patent to Andrews, No. 3,204,362 to mount and secure fishing rods and reels.
Fischer, U.S. Pat. No. 2,041,749, McDaniel, U.S. Pat. No. 3,489,288, and Modrey, U.S. Pat. No. 2,889,050 show typical merchandise displays with locks to prevent pilferage.
The merchandise displays with security locks heretofore available had various shortcomings including lack of security, limitations as to the mounting of the articles to be displayed, excessive cost of manufacture, and restriction as to the location of use.
SUMMARY OF THE INVENTION
In accordance with the invention, a merchandise display is provided preferably in the form of a closed elongated box of stamped sheet metal capable of being mounted vertically or horizontally, with a front face having struck-out sockets for the reception of spaced portions of an article, such as the ends of the rod engaging and mounting portions of a fishing reel, a locking rod, spring operated in one direction and key operated in the other being provided in the interior of the box with locking pins for holding the articles in the sockets, the rod normally being spring urged to locking position, a slidable plate accessible for operation from the front faces holding the locking pins against the force of the spring out of locking engagement with the articles.
It is the principal object of the invention to provide a merchandise display having structure for preventing pilferage which is simple in construction yet reliable in its operation.
It is a further object of the invention to provide a merchandise display of the character aforesaid which has a higher order of security and protection of the merchandise than many of the structures heretofore available.
It is a further object of the invention to provide a merchandise display of the character aforesaid in which the retention against unauthorized removal is easily controlled.
Other objects and advantageous features of the invention will be apparent from the description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part hereof, in which:
FIG. 1 is a view in perspective of a merchandise display in accordance with the invention, parts being broken away to show the details of construction;
FIG. 2 is a view in elevation as seen from the rear and with the rear closure plate removed;
FIG. 3 is a longitudinal central sectional view showing the locking rod in locking position.
FIG. 4 is a fragmentary transverse sectional view taken approximately on the line 4--4 of FIG. 2;
FIG. 5 is a fragmentary longitudinal sectional view taken approximately on the line 5--5 of FIG. 4;
FIG. 6 is a fragmentary transverse sectional view taken approximately on the line 6--6 of FIG. 2 and showing the slide plate in its upper position;
FIG. 7 is a fragmentary view in elevation of a portion of FIG. 2, enlarged, and showing the locking rod and slide plate with the locking pins held out of locked position;
FIG. 8 is a transverse sectional view taken approximately on the line 8--8 of FIG. 2 and showing one of the locking pins held out of locked position; and
FIG. 9 is a view similar to FIG. 8 but showing one of the locking pins in locked position as in FIG. 3.
It should, of course, be understood that the description and drawings herein are illustrative merely and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.
Like numerals refer to like parts throughout the several views.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, the merchandise display in accordance with the invention preferably includes an elongated box like housing 10 having a front wall 11, side walls 12 and 13, an end wall 14 which may serve as a top wall and an end wall 15 which may serve as a bottom wall. The housing 10 is preferably formed as a stamping of sheet metal.
A rear or bottom closure wall 18 is provided, also preferably formed as a stamping of sheet metal having side flanges 19 to which the side walls 12 and 13 are secured in any desired manner such as by pop rivets 20. The wall 18 has end extensions 21 beyond the end walls 14 and 15 with openings 22 for securing the housing 10 in a vertically upright position, in a horizontal position or inclined, if desired, by screws 23 or other fasteners.
A locking rod 25 is provided rotatably carried at one end which may be the upper end adjacent and inwardly of the end wall 14 by a lug 26 struck in from the front wall 11. The locking rod 25 at its opposite end has a shoulder 27 resting on a lug 28 struck in from the front wall 11 adjacent and inwardly of the end wall 15.
The rod 25 contiguous to the lug 26 has a pin 29, preferably a cotter pin, extending through an opening 30 in the rod 25. The eye end of the pin 29 serves for the attachment of one end of a tension spring 31, the other end of the spring 31 being engaged with a hooked lug 32 struck in from the side wall 13. The eye end of the pin 29 by its engagement with the interior of the wall 11 can serve as a limit stop in one direction of rotation of the rod 25 and the bifurcated end of the pin 29 by its engagement with the interior of the wall 11 can serve as a limit stop in the other direction of rotation of the rod 25 urged by the spring 31.
The terminal end 33 of the rod 25 inwardly of the wall 15 is preferably flattened and shaped like a screw driver bit and is accessible through an opening 34 in the end wall 15 for operation by a key 35 having a tubular portion 36 with a cross slot 37 for engagement with the rod end 33.
The front wall 11 is provided with a plurality of transversely arcuate integral sockets 40 formed as outward protuberances, and preferably closed at their ends disposed toward the wall 15. In longitudinally spaced relation to the sockets 40 on the front wall 11, additional sockets in the form of integral arcuate bands 42 are provided open toward the open portion of the sockets 40 and at least partially closed at their other ends as at 43. The bands 42 are preferably longer, longitudinally of the front wall 11 than the sockets 40 to permit of the insertion thereinto of one end of an elongated article such as the mounting plate M of a fishing reel to an extent to engage the interior of the band end 43, the other end of the elongated article first clearing the socket 40 and then being slid into the socket 40 while still restrained by the band 42 where it is retained in a vertical, horizontal or tilted position of the housing 10.
The locking rod 25 is provided with a plurality of radially outwardly extending locking pins 45, one preferably being located substantially centrally of each band 44. It will be noted that the pins 45 are movable, urged by the spring 31 into positions as shown in FIGS. 2, 3 and 9 for locking engagement with one end of the article M to be protected, the other end of the article M being simultaneously held in the socket 40.
In order to hold the locking pins 45 out of their locking positions, a slide plate 46 is provided, carried on a mounting bolt 47. The bolt 47 is slidable in an elongated slot 48 in the front wall 11 and is movable to one limit position as indicated in FIGS. 2 and 3, where it is positioned so that the contiguous pin 45 cannot engage therewith, and the pins 45 are moved to an article locking condition as in FIG. 9.
The slide plate 46 is also movable to another limit position, as indicated in FIGS. 7 and 8, where it is positioned so that the pins 45 are held out of article locking condition.
The mode of operation will now be pointed out.
The key 35 is engaged with the rod end 33, the rod 25 turned counterclockwise at the end wall 15 and against the force of the spring 31 and the pin 45 contiguous to the slide plate 46 moved from the locking position of FIG. 9 to the position shown in FIG. 8, the slide plate 46 being moved toward the end plate 15 so as to hold the locking pin 45 out of locking position. The key 35 is then removed.
The articles to be supported and displayed are mounted each with one of its ends in the sockets 40 and with its opposite mounting end within the bands 42 as illustrated in FIG. 1.
The articles can be left in their unsecured condition with the slide plate 46 holding the locking pins 45 as illustrated in FIG. 8.
If desired, at this time or subsequently, the slide plate 46 can be moved by movement of the bolt 47 in the slot 48 away from the end plate 15 to release the locking pin 45 (FIGS. 7 and 8) so that it moves urged by the spring 31, to the locking position shown in FIGS. 3 and 9 and in engagement with one end of the article while the other end is held in the socket 40.
The articles will then be securely held against pilferage, the socket 40 and band 42 preventing access for removal of the articles and the locking bar 25 and its pins 45 being difficult of access for release.
By turning of the key 35 counterclockwise the articles can be readily released for examination by a prospective purchaser.
While the articles shown are fishing reels other objects having end portions could be stored and retained if desired.
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A merchandise display is disclosed with a security lock to prevent pilferage, the display including an elongated box on the upper or outer face of which the articles are mounted for display, with an interiorly disposed rotatable locking rod, key operated for locking and release of the articles.
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FIELD OF THE INVENTION
This invention relates to an outerwear garment, typically a jacket or the like garment as used by sportsmen, hunters, and other persons involved in outdoor activities.
BACKGROUND OF THE INVENTION
Convertible constructions of outerwear garments are known in the art which incorporate a concealed carrying bag within which the garment can be stored for ease of transportation at the time the garment is not required for use.
An example of such a convertible garment is disclosed in Breier U.S. Pat. No. 2,825,902 issued Mar. 11, 1958. Breier teaches a light-weight garment construction, such as a rain jacket, in which the yoke of the garment is of double walled construction, and is provided interiorly of the garment with a reversible slide fastener for closing an opening into the interior of the double-walled yoke.
Thus, in normal usage, the fastener is closed to connect the two walls of the yoke to each other at the opening positioned at the bottom edge of the yoke, and, the rain jacket is worn by the user in the usual manner.
If the user no longer requires the jacket for use as a rain jacket, then, upon removal of the garment, the user can open the slide fastener, fold the jacket appropriately, and then position the folded jacket within the envelope formed by reversing the inner and outer walls of the yoke with respect to each other, subsequent to which the envelope can be closed by use of the then reversed slide fastener.
While such a construction lends itself to relatively light-weight garments, such as those assembled from light-weight woven fabrics of cotton or synthetic materials, such a construction is limited to such a use, in that the internal volume of the envelope within which the folded garment is to be stored is relatively small and is limited in its size by the physical dimensions of the yoke. Further, the positioning of the slide fastener at the lower edge of the yoke can constitute a source of discomfort for the user, in that the slide fastener then lies directly over the upper regions of the shoulder blades of the user and can dig into the shoulder blades as the user exercises normal movements of the user's arms. Typically, the lower edge of the yoke lies at a central position or upwardly of the arm holes of the garment, at which position the yoke is subjected to tensioning at the time the user moves the user's arms forwardly.
Itoi in U.S. Pat. No. 4,502,154 issued Mar. 5, 1985 avoids these disadvantages, firstly by providing an opening in a front face of an outer garment at a position for it to extend across the lower rib cage of the user, and, by providing a storage pouch which normally is positioned between an inner and an outer front panel of the garment, and which can be pulled outwardly of the garment to provide a carrier bag for storage and transportation of the garment at the time the garment is not required for use and has been appropriately folded.
This construction, however, is encumbered with the disadvantage that an opening must be provided in the outer front panel of the garment, and, some means must be provided not only for closing that opening, but also, for preventing the seepage of water or moisture into the pouch when the garment is worn in inclement weather.
SUMMARY OF THE INVENTION
The present invention seeks to eliminate these disadvantages, firstly by providing a pouch of enhanced dimensions for storage of the garment when the garment is not in use, and which is of sufficient size that not only the folded garment can be stored within the pouch for transportation, but also, sufficient space is provided for the storage of other personal articles of the user, such as books, personal radios, comestibles and additional clothing.
Additionally, the pouch is of sufficient dimensions that it can store an outer garment of relatively heavy weight, such as fall or winter weight garments having a relatively thick and sturdy outer shell and a relatively bulky thermal lining.
Further, this is accomplished in the absence of providing unsightly closures exposed on the outer face of the garment, and additionally the opening into the storage pouch is provided at a location in which it is isolated from rain water, snow, or other moisture that possibly could seep into the pouch at the time the garment is in use.
According to the present invention, the convertible garment includes an outer shell which is fully or partially lined, and which includes a continuous outer rear panel, and an inner rear panel co-extensive with the outer rear panel and which in combination substantially provide the back section of the garment.
The inner rear panel is formed in two sections for it to provide a upper section providing a yoke terminating at its lower edge at a position spaced only slightly above the lowermost curvature of the arm holes of the garment, and a lower section that is continuous downwardly towards the lower edge of the garment, the lower edge of the lower rear panel either being directly attached to the lower edge of the outer rear panel, or hanging freely relative to the lower edge of the outer rear panel.
A pouch is provided within the back section of the garment, the pouch extending substantially the full width and height of the said lower section of the inner rear panel, and being directly attached at its upper rear edges, respectively, to the lower edge of the upper section of the inner rear panel and to the upper edge of the said lower section of the inner rear panel.
In this manner, not only are the dimensions of the pouch increased to a permissible maximum, but also, the opening to the pouch is positioned interiorly of the garment, thus isolating the pouch from water seepage at the opening into the pouch.
Further, the fasteners used for closing the opening are positioned at a location in which discomfort to the wearer of the garment is minimized. Conveniently, the fasteners are in the form of an invertible slide fastener.
DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a frontal view of the internal surface of the convertible garment of the invention, showing the location of the concealed pouch;
FIG. 2 is a vertical cross-section through the rear panel of the garment of FIG. 1, and is taken on the line 2--2 in FIG. 1;
FIG. 3 is a cross-section corresponding with FIG. 2, but showing the concealed pouch withdrawn from its position of concealment between an outer rear panel of the garment and an inner rear panel thereof;
FIG. 4 is a diagrammatic cross-section illustrating the garment of FIGS. 1 through 3 when appropriately folded and positioned interiorly of the pouch of FIGS. 1 through 3, FIG. 4 being a transverse cross-section taken approximately on the line 4--4 of FIG. 5; and
FIG. 5 is a perspective view illustrating the pouch of FIGS. 1 through 4 when assembled into a carrying bag.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring firstly to FIG. 1, the garment of the present invention typically is one comprised of left and right-hand frontal sections 14 and 16 which are connected by stitching and the like to a rear section 18, the garment appropriately being provided with arm holes 20 accomodating sleeves [not shown] of the garment, the garment in all of these respects being entirely conventional, and being a diagrammatic illustration of a typical outerwear garment as employed by persons involved in outdoor activities.
Departing from this known prior art structure, the back section of the garment, indicated generally at 18 in FIGS. 2 and 3, is a composite structure comprising an outer back panel 22, and first and second inner rear panel sections 24 and 26, each of which appear in frontal view in FIG. 1.
The outer rear panel 22, as is conventional, is either comprised of a single panel providing the back face of the garment, or, and again as is conventional, is comprised of one or more panels suitably connected to each other by stitching in order to comprise a single and interrupted back panel, even though the back panel may have stitched seams, gussets, actual or simulated storm flaps, and other such constructions as are common in the art, the rear panel extending from a collar portion 28 of the garment in a continuous sweep down to the lower marginal edge 30 of the garment.
Departing from these conventional constructions, the convertible garment of the present invention provides an inner rear panel comprised of the upper and lower panel sections 24 and 26, the respective panel sections 24 and 26 being interconnected at their respective lower and upper edges by any convenient form of fastening means, such as by the illustrated slide fastener 32.
For reasons later discussed, the slide fastener 32 is of the reversible type, i.e., one having dual pull tabs arranged on opposite sides of the slide fastener in order that the slide fastener can be operated with equal facility from either side of the slide fastener.
The slide fastener 32 is positioned interiorly of the garment such that it is below the lower edge of the conventional yoke of a garment, i.e., at the position indicated diagrammatically by the chain dotted line 34. Preferably the slide fastener 32 extends between the lower curvatures of the arm holes 20, such that the slide fastener 32 is of approximately the same length as the major width of the back panel 18, and closely approximates the width of the lower section 26 of the inner back panel 24, 26.
Referring now more particularly to FIG. 2, positioned between the outer rear back panel 22 and the inner rear back panel section 24, is a pouch 36 which is closed at its bottom and side edges, and, at its top edges is connected respectively to the upper rear panel section 24 and to the lower rear panel section 26. Except for its connections at its upper edges to the rear panel sections 24 and 26, the pouch 36 otherwise is completely unattached to the remainder of the garment. The pouch 36 can be formed of any suitable light-weight and preferably water-resistant material, such as light-weight rubberized cotton fabric, or, a fabric woven from synthetic plastics material, or, less preferably, can be a sheet of flexible extruded plastics material such as vinyl sheeting.
At the time of wearing of the garment with the pouch in the position indicated in FIG. 2, and indicated by dotted lines in FIG. 1, the garment can be worn in an entirely conventional manner and without any discomfort to the user, in that the relatively thin and flexible pouch 36 will move readily with body motions of the user in unison with the outer rear panel 22 and the inner rear panel sections 24 and 26. Further, as the slide fastener 32 is positioned at a location lower than that of the usual yoke of a garment, the slide fastener itself will not be subjected to tensional stresses as the user moves his arms, the slide fastener 32 being located adjacent the softer part of the user's back rather than for it to be in spanning relationship with the user's shoulder blades.
In the event that the outerwear garment is no longer required for use by the user, then, that garment can be folded and stored in the manner now discussed with reference to FIGS. 3, 4 and 5.
Referring firstly to FIG. 3, it will be seen that the pouch 36 has been moved, and in fact turned inside out from its position shown in FIG. 2, by firstly unfastening the slide fastener 32, and then, reaching into the opening between the respective sections of the slide fastener, and, by then pulling the pouch 36 outwardly from its previous location between the back rear panel 22 and the back inner panel section 26, subsequent to which the garment can be folded by folding the rear sections 14 and 16 and the sleeves of the garment rearwardly into overlying relationship with the rear back panel 22, subsequent to which the folded garment can be moved into the pouch 36 as diagrammatically illustrated in FIG. 4.
The slide fastener then can be closed from its opposite side in the entirely conventional manner to form the pouch 36 into a conventional carrying bag 40 as illustrated in FIG. 5, the carrying bag preferably being provided with straps 42 for convenience in transportation of the bag 40.
Referring now more particularly to FIGS. 1 and 2, it will be seen that the pouch 36 extends almost the full height of the inner rear panel section 26. Thus, the circumference of the bag that can be formed by the pouch 36 is approximately double that of the height of the inner rear panel 26.
Thus, the pouch 36 is capable of forming an extremely comodious bag 40 which not only will accomodate the folded and stored garment, but which also will provide adequate space for the storage of further personal articles of the user, such as a sweater, books, a personal radio or comestibles such as packages of food, a thermos flask and the like. Further, when in its retracted position as illustrated in FIG. 2, the pouch 36 conveniently can serve for the protection and transportation of relatively flat articles such as maps, magazines or newspapers, which the user may find inconvenient to carry in the user's hands.
In view of the comodious capacity of the bag 40 formable from the pouch 36, restrictions are removed on the weight and bulk of the garment, which optionally can be formed from light-weight fabrics, but equally well can be formed from relatively heavy winter-weight fabrics, the outer shell of the garment conveniently being formed from a heavy weight woven blanket cloth, the inner facings of the garment additionally or alternatively being formed from a material having excellent thermal insulation properties, such as a relatively heavy-weight flannel, woven blanket cloth, or, a relatively bulky manufactured fur fabric, such as a simulation of fleece or animal fur.
It will be appreciated that various modifications may be made in the structure of the preferred embodiment as discussed above without departing from the scope of the appended claims, including various selections of materials and positioning, and, that if desire, the yoke of the garment can be provided with a conventional hood to cowl which is to be positioned between the outer rear panel 22 and the inner rear panel section 24, and which is withdrawable through an opening at the collar line of the garment.
While the invention has so far been described with reference to an open fronted garment such as a jacket, it will be appreciated that the invention finds equal application in a closed fronted garment, such as a tunic or a vest, the only requirement being that the tunic or vest be turned inside out prior to opening the slide fastener 32 and withdrawal of the pouch 36. Once so positioned, the tunic or vest can be stored within the pouch 36 with equal facility to the open fronted garment specifically discussed with reference to the preferred embodiment of the invention.
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A convertible garment, such as a jacket, tunic or vest, includes a pouch concealed between inner and outer rear walls of the garment, and which can be withdrawn through an aperture in the inner rear wall of the garment for the pouch to be employed as a carrying bag for the garment when the garment is apropriately folded, the carrying bag provided by the pouch having an internal volume in excess of the volume of the garment when appropriately folded and stored within the carrying bag provided by the inverted pouch.
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RELATED APPLICATIONS
[0001] The present application is related to U.S. Provisional Patent Application Ser. No. 60/442,490 filed on Jan. 24, 2003, which is incorporated herein by reference and to which priority is claimed pursuant to 35 USC 119.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to optical amplifiers and oscillators, and in particular to solid state lasers such as semiconductor diode lasers (SDL's) and fiber amplifiers in which the amplified light is confined to propagate in optical waveguides.
[0004] 2. Description of the Prior Art
[0005] The amplifiers in issue here employ waveguides and depend for confinement not on total internal reflection from the index of refraction or discontinuity or gradient of the index as is the usual case, but rather on Bragg reflection from an artificially rendered periodic or quasi periodic medium. Such waveguides were first proposed and analyzed in 1976, and demonstrated in 1977 in planar geometries. An extension of this idea to fibers with a circular cylindrical geometry took place in 1978.
[0006] [0006]FIGS. 1, 2 a, 2 b, 3 , 4 a and 4 b illustrate generically, a conventional dielectric waveguide, a fiber waveguide, a transverse Bragg waveguide and a Bragg confined fiber respectively. FIG. 1 a diagrammatic perspective view which shows a waveguide where n 2 >n 1 of the surrounding material and where the light bounces down the waveguide and is confined by the discontinuity in the index of refraction. FIG. 2 a a diagrammatic perspective view of a planar realization of transverse Bragg waveguide layers. FIG. 2 b a diagrammatic perspective view of an embodiment where the planar alternating periodicity is due to a corrugated wavy interface of an epitaxially grown layer. FIG. 3 is a diagrammatic perspective view of a conventional clad optic fiber where n 2 >n 1 . FIG. 4 a a diagrammatic perspective view of a cylindrical Bragg fiber where light is guided in the core and is Bragg reflected at the interface. FIG. 4 b a diagrammatic perspective view of a waveguide where the index contrast between two adjacent layers is realized using longitudinal bores longitudinal bores which are empty or filled.
[0007] A recent paper by the inventor shows that periodic waveguides require that the width w of the periodic channel must be related to the unit cell dimension b. In the simplest case of a small index perturbation where Δn<<n, w=b/4.
BRIEF SUMMARY OF THE INVENTION
[0008] The invention in the illustrated embodiment is directed to a semiconductor optical device comprising a transverse Bragg resonance waveguide comprised in turn of a waveguiding channel, and on at least two opposing sides of the channel two periodic index media; and a means for providing gain in the periodic index media.
[0009] The semiconductor optical device may be included within a laser, amplifier or oscillator.
[0010] In one embodiment the waveguiding channel is planar and is sandwiched on two opposing sides by the periodic index media. In another embodiment the waveguiding channel is cylindrical and is surrounded by the periodic index media. In one embodiment the means for providing gain in the periodic index media is electrical. In another embodiment the means for providing gain in the periodic index media is optical. The periodic index media comprises in one embodiment a periodic lattice of regions having an index of refraction distinct from the channel, such as an array of transverse holes defined in a planar semiconductor substrate in which the channel is also defined, or an array of longitudinal holes defined in a cylindrical semiconductor fiber in which the channel is also longitudinally defined.
[0011] The invention is also characterized as a method of operating a transverse Bragg waveguiding device as described above, while providing gain in the periodic index media while propagating the light wave.
[0012] Further the invention is defined as a method of providing an active transverse Bragg resonance waveguide comprising fabricating a planar waveguiding channel and sandwiching the planar waveguiding channel on two opposing sides by a periodic index media, and providing gain to the periodic index media, or fabricating a cylindrical waveguiding channel and surrounding the cylindrical waveguiding channel by a periodic index media, and providing gain to the periodic index media. The periodic index media can be electrically or optically pumped to provide gain.
[0013] In the illustrated embodiment the light wave is propagated at a detuned frequency given by k 0 =(1+v) π/b where k 0 is the modal wave number of the propagated light, v is the frequency, and b is the transverse periodicity of the periodic index media.
[0014] The semiconductor optical device is operated in a mode which has a gain enhancement, η, due to an increase of a gain constant, β I , of the propagating wave over the gain constant of a bulk dielectric and a substantial electric field content outside the channel leading to a larger modal cross-sectional area, and higher output power.
[0015] While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a perspective diagrammatic view of a prior art dielectric waveguide.
[0017] [0017]FIG. 2 a is a perspective diagrammatic view of a prior art planar transverse Bragg waveguide.
[0018] [0018]FIG. 2 b is a perspective diagrammatic view of a prior art corrugated interface Bragg waveguide.
[0019] [0019]FIG. 3 is a perspective diagrammatic view of a prior art cylindrical, cladded, optical fiber.
[0020] [0020]FIG. 4 a is a perspective diagrammatic view of a prior art cylindrical Bragg fiber.
[0021] [0021]FIG. 4 b is a perspective diagrammatic view of a prior art modified cylindrical Bragg fiber.
[0022] [0022]FIG. 4 b is a perspective diagrammatic view of a prior art modified cylindrical Bragg fiber.
[0023] [0023]FIG. 4 b is a perspective diagrammatic view of a prior art modified cylindrical Bragg fiber.
[0024] [0024]FIG. 5 a is a perspective diagrammatic view of a prior art passive Bragg reflector.
[0025] [0025]FIG. 5 b is a perspective diagrammatic view of a prior art active Bragg reflector.
[0026] [0026]FIG. 6 is a top plan diagrammatic view of a two dimensional Bragg waveguiding structure according to the invention.
[0027] [0027]FIG. 7 is a perspective diagrammatic view of a transverse Bragg reflecting amplifier according to the invention.
[0028] [0028]FIG. 8 a is a graph of the real part of the electric field, E, in the core of a waveguiding structure without gain as a function of transverse distance.
[0029] [0029]FIG. 8 b is a graph of the real part of the electric field, E, in the core of a waveguiding structure with gain as a function of transverse distance.
[0030] The invention and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the invention defined in the claims. It is expressly understood that the invention as defined by the claims may be broader than the illustrated embodiments described below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] [0031]FIGS. 1, 2 a, 2 b, 3 , 4 a and 4 b are examples of passive waveguiding where all the materials involved are low optical loss and are ideally transparent. In contrast in the invention the optical confinement is based on “pumping”, i.e., activating the periodic Bragg media so that it is capable of amplifying light. How this pumping is achieved can vary from one laser type to another and the preferred embodiments are discussed below.
[0032] While a passive periodic medium acting as a Bragg reflector as shown in the perspective view of FIG. 5 a can achieve reflectivities approaching, but never achieving, 100%, (i.e., with gain) periodic medium can achieve reflectivities R>1, i.e., the reflected light power exceeds that of the incident power. The pumping mechanism shown schematically in the perspective view of FIG. 5 b is an electric current 12 in the case of a semiconducting medium or an optical beam 12 of the proper wavelength, usually shorter than that amplified by the medium 10 , either of which is used to excite atoms of the periodic medium 10 so as to create an amplifying inverted atomic population.
[0033] In the top diagrammatic plan view of FIG. 6 we show another embodiment of a planar transverse Bragg waveguide 14 in which the periodicity is achieved by forming or drilling holes 16 into the two-dimensional guiding layer 18 . A two dimensional waveguiding structure is provided which is comprised of a guiding channel of width W, a core, between two semi-infinite arrays of air holes 16 in a periodic pattern, e.g. a triangular lattice acting as a cladding. Shown in the core or region 22 of FIG. 6 are two in-plane k vectors of the plane waves that comprise the waveguide mode. The mode can be visualized as a wave, represented by the arrows 20 , zigzagging down the channel of region 22 and Bragg reflected at the interface with region 24 . If region 24 on both or one side is pumped, then upon each reflection the wave grows a bit and its intensity increases along the Z direction, which in FIG. 6 is the direction of wave propagation, i.e., we have an amplifier.
[0034] In the diagrammatic perspective view of FIG. 7, we show an embodiment using a current injected semiconductor laser material similar to that used in commercial semiconductor diode lasers. N type InP cladding 28 is formed on a multiple quantum well regions 30 disposed on a p-type InP substrate into which a plurality of longitudinal trenches 32 have been formed and filled by an adjacent InGaAs layer 34 , which is then finished with a-type InP cladding layer 36 . Pumping electrodes are provided on cladding layers 28 and 34 . Here the transverse modulation is achieved by etching a channel 26 parallel to the Z axis of the core and “refilled” using a material with a different index, namely InGaAs. Parallel trenches 32 flanking guiding channel 26 define a periodic index variation in the transverse X direction and contribute to modal confinement.
[0035] The advantages of such an amplifier are manifold:
[0036] (1) The wave incident on the interface of the waveguide and the surrounding material is not reflected simply at the interface. It penetrates a considerable distance which may exceed the channel width W by a considerable factor (>1). It can thus “milk” a large volume of amplifying medium which results in gain per unit length, in the direction, far in excess of what is possible in conventional based amplifiers.
[0037] (2) Higher order modes are discouraged by the need to satisfy the Bragg condition (k transverse b=π). Otherwise the reflectivity and gain diminish.
[0038] (3) There exist numerous ways of pumping the periodic medium, as shown by way of example in FIGS. 5 b and 7 . The basic structure uses an epitaxially grown semiconductor crystal. A p˜n junction near the corrugated interface provides optical gain when current is made to flow across the junction.
[0039] In a similar fashion an optical fiber amplifier results if the periodic annular media are made active (amplifying). This can be done, for instance, by doping the glass n 1 and n 2 layers with Erbium and shining a pumping light at 1.48 μm or 0.98 μm in the manner used to pump conventional optical fiber amplifiers. Another method involves employing groups of holes parallel to the axis as shown in FIG. 4 b. Each ring of holes acts effectively as one of the annular rings of FIG. 4 b, for example, as one of the n 1 rings.
[0040] The physics underlying the above embodiments can now be described. What is disclosed is an optical amplifier which is formed by providing gain in the periodic “cladding” of a transverse Bragg resonance waveguide. Using the coupled-wave formalism, we calculate the mode profiles, the exponential gain constant and, for comparison, the gain enhancement over conventional semiconductor optical amplifiers. In contrast with coupled-mode theory in one-dimensional structures (e.g., the DFB laser), the exponential gain constant in the longitudinal direction is involved in both the longitudinal and transverse confinement, and has to be solved for self-consistency, together with the quantized guiding channel width.
[0041] The invention can be implemented as an optical laser, amplifier or oscillator. In the preferred embodiment the amplifier is comprised of a guiding channel 50 (or “core”) which is sandwiched between two periodic-index media 52 (or “cladding”), or in a cylindrical geometry, surrounded by it. The periodic media 52 possess optical gain, and the core 50 may or may not. The basic concept behind this amplifier is the following: It is well known that one can form optical waveguides which depend on Bragg reflection from a periodic cladding, rather than on total internal reflection. It is also known that if the periodic medium possesses optical gain then an incident wave can be amplified upon reflection. These two ideas are combined here, and referring to FIG. 6, imagine a plane-like wave zigzagging inside a uniform guiding channel 22 which is flanked on each side by amplifying periodic media 24 . Since the wave is amplified upon each reflection, we expect the wave to grow exponentially along Z. In conventional laser amplifiers, one usually solves for the electromagnetic modes of the passive confining structure, and “adds” the optical gain assuming that the presence of gain modifies the modes only negligibly. This is not the case when the confinement is due to Bragg reflection, since in this case the field distribution inside the periodic medium 24 changes drastically when gain is present. The amplification and confinement issues have to be addressed self-consistently. The theoretical issues which arise and some of the features of the transverse Bragg resonance (TBR) amplifiers are entirely novel.
[0042] Referring to FIG. 6, we seek a modal propagating solution to the Helmholtz equation (1)
∇ 2 E ( r , t ) - με ( r ) ∂ 2 E ( r , t ) ∂ t 2 = 0. ( 1 )
[0043] We allow ε(r) to be complex, ε(r)=ε R (X)+i ε I (X), and seek a solution with an exp[i(ωt−βz)] dependence, where β=β R +i β I . Modal amplification obtains when β I >0.
[0044] The wave equation, Eq. (1), now reads
2 E x 2 + ( ω 2 μ ε R - β R 2 ) E + ( ω 2 μ ε I - 2 β R β I ) E = 0 , ( 2 )
[0045] where we have assumed that I β I <<I β R I. In the periodic cladding, with unit cell (bx×az), we can represent
ε R ( r ) = ∑ m , n ε Rm n exp ( K m n · r ) , ( 3 )
[0046] where
K m n = m ( 2 π b ) x ^ + n ( 2 π a ) z ^ .
[0047] The only term in the expansion capable of coupling, by phase-matched Bragg reflection, the two plane wave components of the field in the core region is the term m=1, n=o which can be written as
ε R ( x ) = ε R0 - 2 ε I cos ( 2 π b x ) , ( 4 )
[0048] where
ε 1 ≡ ε 01 = 1 a b ∫ ∫ u . c . ε ( r ) exp ( - 2 π b x ) x z . ( 5 )
[0049] A substitution of Eq. (4) renders Eq. (2) into the form,
2 E x 2 + k 0 2 E - 2 ω 2 μ ε I cos ( 2 π b x ) E + ( ω 2 με I - 2 β R β I ) E = 0. ( 6 )
[0050] where k 0 2 ≡ω 2 με R0 −β R 2 .
[0051] We look for solutions in the combined core and cladding regions of the general form,
Ε( z,χ,t )=[ A (χ) e −ik 0 ψ +B (χ) e ik 0 χ ].e i(ωt−βz) ≡Ε⊥(χ) e i(ωt−βz) , (7)
[0052] which is motivated by the fact that when ε 1 =0 and ε I =0 (which implies that β 1 =0), A and B are independent of x and also of each other. A substitution of Eq. (7) into Eq. (6) and in the vicinity of the Bragg condition k o ≈π/b (k o ≈2π/b for the triangular lattice) results in the familiar coupled wave equations,
A x = γ A + κ * B 2 ( k 0 - π / b ) x
B x = - γ B + κ A - 2 ( k 0 - π / b ) x ( 8 )
[0053] on the interval 0≦x≦L, the cladding region. We have defined
γ = ω 2 μ ε I ( clad ) 2 k 0 - β R β I k 0 , κ = - ω 2 μ ε I 2 k 0 . ( 9 )
[0054] We solve Eq. (8) subject to the condition that at the outer edge of the cladding, there is no reflected wave, i.e., B (L)=O. The result is a superposition of Bloch waves,
E ⊥ ( clad ) ( x ) = F { - π x / b ( γ - Δ k ) sinh [ S ( L - x ) ] - S cosh [ S ( L - x ) ] ( γ - Δ k ) sinh [ S L ] - S cosh [ S L ] +
+ π x / b κsinh [ S ( L - x ) ] ( γ - Δ k ) sinh [ S L ] - S cosh [ S L ] } ( 10 )
[0055] where
S ≡ κ 2 + ( γ - Δ k ) 2 , Δk ≡ k 0 - π b , ( 11 )
[0056] and F is a scale factor which will be needed in matching the fields at x=0. The “exact” Bloch solution Eq. (10) is a key ingredient in our modal solution.
[0057] In the uniform core region (−W≦x≦0), the field is governed by the Helmholtz equation, Eq. (6), with ε 1 =0. We assume that the real part of the average dielectric constant ε R is the same in both the core and cladding regions, and will present results for two cases, (a) gain in the cladding as well as the core, ε I core =ε I clad , and (b) gain in the cladding only, ε I core =0. We write the solution as
Ε ⊥ (core) (χ)= e −ik′(χ+W/2) ±e ik′(χ+W/2) (12)
[0058] where
k ′ ≡ k 0 [ 1 + 2 k 0 2 ( ω 2 μ ε 1 ( core ) - 2 β R β I ] . ( 13 )
[0059] The signs + and − in Eq. (12) go with modes of even or odd symmetry, respectively.
[0060] In Eqs. (10) and (12), we have the field solutions for the cladding and the core, respectively. These two solutions are stitched together at the interface by requiring that the +x-traveling component in the core is the same as its counterpart in the cladding at x=0. The same condition is applied to the waves traveling in the −x direction. This ensures the continuity of the total fields at x=0, and to a very high degree (consistent with the basic nature of the perturbation involved in a coupled-wave approach) the continuity of the total field derivative. It is also the condition used to obtain the reflectance of Bragg gratings. These two conditions can be expressed, using Eqs. (10) and (12), as
exp ( - k ′ W / 2 ) = F ,
exp ( k ′ W / 2 ) = ± κ F ( γ - Δ k ) - S coth ( S L ) . ( 14 )
[0061] It follows that
k ′ W = ± κ ( γ - Δ k ) - S coth ( S L ) ( 15 )
[0062] where
S ≡ κ 2 + ( γ - Δ k ) 2 , γ = ω 2 με I ( clad ) 2 k 0 - β R β I k 0 , κ = - ω 2 με 1 2 k 0 k 0 2 ≡ ω 2 με R0 - β R 2 , k ′ ≡ k 0 [ 1 + 2 k 0 2 ( ω 2 με 1 ( core ) - 2 β R β I ) ] .
[0063] Eq. (15) is the main result of this analysis. It can be written in terms of magnitude and phase as
exp [ ( β R β I k 0 - ω 2 με 1 ( core ) 2 k 0 ) W ] = κ ( γ - Δ k ) - S coth ( S L ) , ( 16 ) k 0 W = Phase [ ± κ ( γ - Δ k ) - S coth ( S L ) ] . ( 17 )
[0064] Eq. (17) is used to determine the core width. In the case of a passive triangular lattice and Δk=0, Phase(κ)=−π/2 and since k 0 =2 π/b, the allowed values of W are b/4, 5b/4, . . . for even symmetry modes and 3b/4, 7b/4, . . . for odd symmetry modes. The latter require the use of the (−) sign in Eq. (12). Below we will concentrate on the even-symmetric lowest-order solution.
[0065] The full transverse profile is given by
E 1 ( x ) = { E 1 ( clad ) ( x ) , 0 < x ≤ L E ( core ) ( x ) , - W ≤ x ≤ 0 E 1 ( clad ) ( - x + W ) , - ( L + W ) ≤ x < - W ( 18 )
[0066] The modal equations, Eqs. (16) and (17), both involve the gain constant β I and the core width W in a complicated way, which requires a self-consistent numeric solution. We analyze two structures: the first with cladding width L=5 μm and the second with cladding width L=15 μm.
[0067] For L=5 μm, FIG. 8 a shows the transverse mode profiles when ε 1 core =0 and FIG. 8 b shows the transverse mode profiles when ε 1 core =ε 1 clad . The Bloch nature of the field in the cladding is clearly evident. We use the following numerical values: wavelength λ o =1.55 μm; real part of dielectric coefficient ε R =12.5 ε 0 ; imaginary part of dielectric coefficient ε I =10 −3 ε R ; strength of grating ε I =ε R /40; transverse periodicity of cladding b=1.25×1.55 μm. The calculated numerical values of the gain and core width etc. in all four cases are listed in
TABLE 1 L cladding width (each 5 5 15 15 section) μm μm μm μm ε 1 (core) core gain yes no yes no W core width 484 265 126 55 nm nm nm nm β 1 gain constant 72.7 58.7 74.4 73.3 cm −1 cm −1 cm −1 cm −1 ν detuning 0 0.124 0.183 0.199 η gain enhancement 3.58 2.89 3.67 3.61 power leakage −34.4 −26.8 −47.2 −31.2 dB dB dB dB
[0068] “Detuning” v is defined by the relationship k 0 =(1+v) π/b, and in most cases, the optimum operating point is not exactly on-resonance, when v=0.
[0069] “Power leakage” refers to the field intensity at the outer edge of the cladding; although the field component propagating towards to the core is taken to be zero by our boundary condition B(L)=0 in solving Eq. (8), the outward-propagating component A(L) is typically not zero. As Table 1 shows, however, it can be made small by increasing the width of the cladding region. For wider cladding (greater L), the envelope has to decay more slowly with x to satisfy B(L)=0; the core width W is forced to be smaller so that the field does not decay as much away from the center peak.
[0070] “Gain enhancement” η refers to the increase of β I I in this structure over the gain constant of bulk dielectric. It is an enhancement of the exponential factor, and the typical increase of 300% or more is a substantial advantage of these structures over conventional uniform-dielectric waveguides. This enhancement reflects the fact that in a Transverse Bragg Resonance laser, the wave “spends” much more time in the cladding than in the core. Greater gain may be achieved, or shorter devices will suffice for given gain. Also, the substantial field content outside the narrow core region leads to a larger modal cross-sectional area, and consequently higher output power, compared to conventional semiconductor laser structures. The field extends further into the cladding in the absence of core gain, ε core =0, indicating a trade-off between overall power output and the longitudinal gain enhancement factor η.
[0071] 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. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations.
[0072] 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.
[0073] 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 this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination.
[0074] Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, 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.
[0075] The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention.
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A transverse Bragg resonance waveguide is comprised of a waveguiding channel, and on at least two opposing sides of the channel two periodic index media; and a means for providing gain in the periodic index media. In one embodiment the waveguiding channel is planar and is sandwiched on two opposing sides by the periodic index media. In another embodiment the waveguiding channel is cylindrical and is surrounded by the periodic index media. The means for providing gain in the periodic index media is electrical or optical pumping. The periodic index media comprises a periodic lattice of regions having an index of refraction distinct from the channel, such as an array of transverse holes defined in a planar semiconductor substrate in which the channel is also defined, or an array of longitudinal holes defined in a cylindrical semiconductor fiber in which the channel is also longitudinally defined.
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RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 13/787,093, entitled BULK BAG WITH PERFORATED SECTIONS, filed Mar. 6, 2013. U.S. application Ser. No. 13/787,093 claims the priority benefit of provisional applications entitled BULK BAG WITH MULTIPLE PERFORATED SECTIONS, Ser. No. 61/607,321, filed Mar. 6, 2012, and BULK BAG WITH CURVED PERFORATION, Ser. No. 61/607,274, filed Mar. 6, 2012. Each of these applications is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is broadly concerned with the field of bags for holding pourable products such as salt. More particularly, the inventive bags have a curved, perforated section at one corner and, in some embodiments a second perforated section that extends substantially, and preferably entirely, horizontally across the bag, for removal and pouring of the product from the bag.
[0004] 2. Description of the Prior Art
[0005] Bag are commonly used to hold and transport pourable products (i.e., products comprising numerous small pieces). Such products include salt cubes or pellets, animal food, flour, and sugar, to name a few. These pourable products are typically sold in large quantities (e.g., 30-50 lbs.) and in bulk sizes that are difficult for the average person to handle. Even more difficult than carrying these bags is pouring the product from the bulky bag. That is, the consumer must open the bag, attempt to pick up the very heavy bag, and carefully pour the product in a controlled manner. This often results in spilling of the product, which goes from not coming out at all to rapidly falling from the bag and outside of the target area. There is a need for a bag that can be more easily opened at the point of use, as well as more easily poured with minimal or no spillage.
SUMMARY OF THE INVENTION
[0006] In one embodiment, the invention provides a bag for holding a pourable product. The bag comprises front and back panels comprising first and second end portions presenting respective outermost edges, and first and second side portions presenting respective outermost edges. The front and back panels and the end and side portions cooperate to form a chamber for holding the pourable product, with the first end portion and the first side portion cooperating to form a first corner. The panels further comprise a seam extending between the first and second side portion outermost edges. The front and back panels comprise perforations at the first corner, and the perforations extend in a non-linear fashion from the outermost edge of the first end portion to the outermost edge of the first side portion. The perforations have a radius of curvature of from about 3 inches to about 4 inches when measured from a point that is about 0.25 inches to about 2 inches from the seam and about 0.1 inches to about 0.75 inches from the outermost edge of the first side portion.
[0007] In a further embodiment, the bag comprises front and back panels each comprising first and second end portions presenting respective outermost edges, and first and second side portions presenting respective outermost edges. The front and back panels and the end and side portions cooperate to form a chamber for holding the pourable product, with the first end portion and the first side portion cooperating to form a first corner. The panels further comprise perforations at the first corner, with the perforations extending in a non-linear fashion from the outermost edge of the first end portion to the outermost edge of the first side portion. Finally, the panels comprise a handle adjacent at least one of the first and second end portions and integrally formed with the bag.
[0008] In another embodiment, a method of using the above inventive bags is provided. The method comprises tearing the front and back panels at the perforations to form an opening, and causing the pourable product to exit the bag from the opening, preferably by tilting the bag.
[0009] In a further embodiment, the invention provides a bag for holding a pourable product. The bag comprises front and back panels comprising first and second end portions presenting respective outermost edges, and first and second side portions presenting respective outermost edges. The front and back panels and the end and side portions cooperate to form a chamber for holding the pourable product. The bag has a width “W,” defined as the shortest distance between the respective outermost edges of said first and second side portions, and the first end portion and the first side portion cooperate to form a first corner. The front and back panels comprise a first set of perforations at the first corner, and the first set of perforations extend in a non-linear fashion from the outermost edge of the first end portion, or from a seam or area near to said outermost edge of said first end portion, to the outermost edge of the first side portion. The front and back panels further comprise a second set of perforations extending from at least one of the respective outermost edges of the first and second side portions a distance of at least about 50% of “W,” towards the other of the respective outermost edges of the first and second side portions.
[0010] In yet a further embodiment, a method of using the above inventive bag is provided. The method comprises tearing the first corner at the first set of perforations to form a first opening, or at the second set of perforations to form a second opening, or at both the first and second sets of perforations to form first and second openings. The pourable product is then caused to exit the bag from the opening or the first and second openings, preferably by tilting the bag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a front elevation view of one embodiment of a bag according to the invention;
[0012] FIG. 2 is a rear elevation view of the bag of FIG. 1 ;
[0013] FIG. 3 is a front elevation view illustrating the dimensions of the bag of FIG. 1 ;
[0014] FIG. 4 is a front elevation view of an alternative embodiment of the bag according to the invention;
[0015] FIG. 5 is a rear elevation view of the bag of FIG. 4 ; and
[0016] FIG. 6 is a front elevation view illustrating the dimensions of the bag of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Bag with Curved Perforations Only
[0017] With reference to FIGS. 1-3 , a bag 10 is illustrated. Bag 10 includes a front panel 12 and a back panel 14 . As shown, front and back panels 12 , 14 are flat to demonstrate their respective shapes before being filled with product. Front panel 12 and back panel 14 share a first end portion 16 and a second end portion 18 .
[0018] Front panel 12 and back panel 14 further share a first side portion 20 and a second side portion 22 . First and second end portions 16 , 18 and first and second side portions 20 , 22 present respective outermost edges 24 a - d , which define an outer boundary or periphery 26 of the bag 10 . Outermost edges 24 a and 24 b oppose, and are substantially parallel to, one another, while outermost edges 24 c and 24 d oppose, and are substantially parallel to, one another. Furthermore, outermost edges 24 c and 24 d are substantially perpendicular to outermost edges 24 a and 24 b.
[0019] Each of the first and second end portions 16 , 18 intersects with first and second side portions 20 , 22 at corners 28 a - d . Front and back panels 12 , 14 , first and second end portions 16 , 18 , and first and second side portions 20 , 22 cooperate to form a chamber for holding a pourable product.
[0020] First end portion 16 comprises a first horizontal seam 30 spaced apart from outermost edge 24 a , thus forming a flap 32 in first end portion 16 . First horizontal seam 30 has a thickness of from about 1/16 inch to about ¼ inch (and more preferably about ⅛ inch) and is substantially parallel to outermost edge 24 a . Flap 32 comprises a handle 34 formed therein. Handle 34 comprises a patch 36 that is heat-sealed to the flap 32 . Patch 36 could be heat-sealed on either side of the flap 32 (i.e., on front panel 12 or on back panel 14 ), or on both sides if extra strength is required. Patch 36 can be any material typically used for bags carrying bulk products, including plastics such as linear low density polyethylenes (LLPDE). A C-shaped grip 38 is formed through patch 36 and flap 32 to form an opening, through which a user may place his or her fingers during carrying, pouring, etc.
[0021] Outmost edge 24 a of first end portion 16 is bisected by centerline 40 (see FIG. 3 ). In a preferred embodiment, handle 34 is positioned such that some portion of the grip 38 falls upon the centerline 40 . Also, while it will be appreciated that the handle 34 is integrally formed with the bag 10 (and particularly with flap 32 ) as described above, one may also substitute an integrally formed handle with a separately formed handle that is then physically attached to the bag 10 . Also, flap 32 could include a small opening (not shown) in or around corner 28 b to provide a place for the user to place his or her finger during pouring to assist with that process.
[0022] First end portion 16 also comprises a pouring spout 42 , preferably at corner 28 a . In the preferred embodiment, the spout 42 comprises perforations 44 , which allow for easy opening of the spout 42 at the time of use.
[0023] As shown in the figures, perforations 44 are in the foam of a curved (i.e., non-linear) pattern rather than a straight line as found in prior art bags. Perforations 44 intersect outermost edge 24 a at point 45 a and outermost edge 24 c at point 45 b approximately (+5°, preferably)+2° a 90° angle. The radius of curvature “R” (see FIG. 3 ) is preferably from about 3 inches to about 4 inches, and more preferably about 3.5 inches. Furthermore, the radius of curvature “R” is measured at a point that is set in from the corner of the bag, at distances D 6 and D′. This non-linear pattern allows product to be more easily poured from open spout 42 as the opening is less prone to closing up on itself. Furthermore, the offset radius of curvature shifts the opening created by spout 42 downwardly towards the pourable product, making the product more flowable from the bag. Advantageously, this design results in an opening at spout 44 that has a cross-sectional area of from about 4 in 2 , to about 31 in 2 , preferably from about 9 in 2 to about 28 in 2 , and more preferably from about 13 in 2 to about 19 in 2 . This design yields a bag that can be emptied 15-20% more quickly than prior art bags.
[0024] The perforation 44 also preferably includes a “starter split” 43 through first horizontal seam 30 . Starter split 43 is an area of weakness that renders perforation 44 easier to tear. Unlike prior art bags, starter split 43 is actually integral within first horizontal seam 30 so that the seam 30 does not hinder tearing due to the inherent perforation weakness.
[0025] Finally, the bag 10 preferably has a side panel 46 . Side panel 46 is essentially a lay-flat fold whose width is defined by a turn axis 48 . Side panel 46 allows for expansion of the bag upon filling with the pourable product.
[0026] Referring to FIG. 3 , several dimensions of the inventive bag 10 have been defined. The ranges for those dimensions are shown in Table 1.
[0000]
TABLE 1
Preferred Bag Dimensions
Dimension
Broad Range
Preferred Range
Most Preferred Range
from FIG. 3
(inches)
(inches)
(inches)
L
about 20 to about 35
about 24 to about 30
about 26 to about 28
W
about 10 to about 24
about 14 to about 20
about 15 to about 18
D 1
about 5 to about 8
about 5.5 to about 7.5
about 5.8 to about 7
D 2
about 4.5 to about 7
about 5 to about 6.5
about 5 to about 6
D 3
about 2 to about 3.5
about 2.2 to about 3
about 2.4 to about 2.8
D 4
about 2.5 to about 5.5
about 3 to about 5
about 3.7 to about 4.5
D 5
about 2 to about 4
about 2.5 to about 4.5
about 2.9 to about 3.2
D 6
about 0.25 to about 2
about 0.75 to about 1.25
about 1
D 7
about 0.1 to about 0.75
about 0.2 to about 0.5
about 0.375
L 1
about 17 to about 30
about 20 to about 28
about 22 to about 26
D 1 /D 2 *
about 0.8 to about 1.7
about 1 to about 1.5
about 1.1 to about 1.3
L/D 1 *
about 2 to about 5
about 3 to about 4.5
about 3.5 to about 4
W/D 2 *
about 1.5 to about 5
about 2 to about 4
about 2.5 to about 3
*Unitless
[0027] This embodiment of the inventive bag 10 can be manufactured by various methods, but the preferred method is described herein. First, a tube or sleeve of plastic is cut to the desired length (represented by “L” in FIG. 3 ). The plastic of which the inventive bag is formed can be any material typically used to form bags carrying bulk products. The plastic should be flexible and stretchable so that the bag collapses as the bulk product is poured from the bag. Preferably, the plastic of which the bag is formed stretches from about 1 to about 2 times at yield, and more preferably about 1.5 times at yield. Furthermore, it is preferred that the bag be formed of a plastic that stretches at least about 4 times, preferably at least about 5 times, and more preferably from about 5 to about 7 times at its break point. Thus, the preferred plastic has an ASTM D882 percent elongation of from about 200% to about 800%, preferably from about 400% to about 700%, and more preferably from about 500% to about 650%. The thickness of the preferred plastic is from about 2 mil to about 14 mil, preferably from about 4 mil to about 10 mil, and more preferably from about 6 mil to about 8 mil. The most preferred material is LLDPE.
[0028] A heat seal is then applied at first end portion 16 in order to form horizontal seam 30 . A film (typically having a 10-mil thickness) is heat-sealed to flap 32 to form patch 36 . C-shaped grip 38 is then cut (e.g., die-cut) through the patch 36 and flap 32 , thus forming handle 34 , which serves as the primary carrying handle. The perforations 44 can be added at this time according to conventional methods in order to form pouring spout 42 .
[0029] The manufactured bag can then be stored until needed, or immediately filled and sealed. Either way, after the bag 10 is filled to the desired level, a final heat seal is applied at second end portion 18 to create second horizontal seam 50 , making the filled bag 10 ready for distribution. It will be appreciated that the inventive bag 10 can be used to transport and store numerous types of pourable products, including cubes, pellets, tablets, powders, compacted pieces, and/or granules of those selected from the group consisting of: salt (e.g., water softening, pool treatment, deicing, etc.); animal food (e.g., bird seed, grain, dog or cat food); bulk flour or sugar; cement; seed (e.g., grass seed) and other lawn and garden products; fertilizers; ice; sand; rice; spices; soil (including soil mixtures); pesticides (e.g., fire ant treatments); industrial chemicals; mortar; plaster; marble dust; stones (including pebbles and gravel); and constructions products. Such products will typically cause the bags to weigh from about 20 lbs. to about 100 lbs., and more typically from about 40 lbs. to about 60 lbs.
[0030] In use and before pouring, a user would tear corner 28 a at perforations 44 in order to remove (or at least partially remove) corner 28 a at spout 42 . This forms an opening at spout 42 , rendering spout 42 ready for pouring. This controlled pouring allows for fairly exact dispensing of the product, while preventing spillage and waste of the product.
Bag with Curved and Full Perforations
[0031] FIGS. 4-6 show an alternative embodiment of the invention. In this embodiment, a bag 10 a is illustrated, with like numbering being used to show like parts from FIGS. 1-3 . Bag 10 a includes a front panel 12 and a back panel 14 . As shown, front and back panels 12 , 14 are flat to demonstrate their respective shapes before being filled with product. Front panel 12 and back panel 14 share a first end portion 16 and a second end portion 18 .
[0032] Front panel 12 and back panel 14 further share a first side portion 20 and a second side portion 22 . First and second end portions 16 , 18 and first and second side portions 20 , 22 present respective outermost edges 24 a - d , which define an outer boundary or periphery 26 of the bag 10 a . Outermost edges 24 a and 24 b oppose, and are substantially parallel to, one another, while outermost edges 24 c and 24 d oppose, and are substantially parallel to, one another. Furthermore, outermost edges 24 c and 24 d are substantially perpendicular to outermost edges 24 a and 24 b.
[0033] Each of the first and second end portions 16 , 18 intersects with first and second side portions 20 , 22 at corners 28 a - d . Front and back panels 12 , 14 , first and second end portions 16 , 18 , and first and second side portions 20 , 22 cooperate to form a chamber for holding a pourable product.
[0034] First end portion 16 comprises a first horizontal seam 30 spaced apart from outermost edge 24 a , thus forming a flap 32 in first end portion 16 . First horizontal seam 30 has a thickness of from about 1/16 inch to about ¼ inch (and more preferably about ⅛ inch) and is substantially parallel to outermost edge 24 a . Flap 32 comprises a handle 34 formed therein. Handle 34 comprises a patch 36 that is heat-sealed to the flap 32 . Patch 36 could be heat-sealed on either side of the flap 32 (i.e., on front panel 12 or on back panel 14 ), or on both sides if extra strength is required. Patch 36 can be any material typically used for bags carrying bulk products, including plastics such as linear low density polyethylenes (LLPDE). A C-shaped grip 38 is formed through patch 36 and flap 32 to form an opening, through which a user may place his or her fingers during carrying, pouring, etc.
[0035] Outmost edge 24 a of first end portion 16 is bisected by centerline 40 (see FIG. 4 ). In a preferred embodiment, handle 34 is positioned such that some portion of the grip 38 falls upon the centerline 40 . Also, while it will be appreciated that the handle 34 is integrally formed with the bag 10 a (and particularly with flap 32 ) as described above, one may also substitute an integrally formed handle with a separately formed handle that is then physically attached to the bag 10 a . Also, flap 32 could include a small opening (not shown) in or around corner 28 b to provide a place for the user to place his or her finger during pouring to assist with that process.
[0036] First end portion 16 also comprises a pouring spout 42 , preferably at corner 28 a . In the preferred embodiment, the spout 42 comprises a first set of perforations 44 , which allow for easy opening of the spout 42 at the time of use.
[0037] As shown in the figures, perforations 44 are in the form of a curved (i.e., non-linear) pattern rather than a straight line as found in prior art bags. Perforations 44 intersect first horizontal seam at point 45 a and outermost edge 24 c at point 45 b approximately (±5°, preferably ±2°) a 90° angle. The radius of curvature “R” (see FIG. 6 ) is preferably from about 3 inches to about 4 inches, and more preferably about 3.5 inches. Furthermore, the radius of curvature “R” is measured at a point that is set in from the corner of the bag, at distances D 6 and D 7 . This non-linear pattern allows product to be more easily poured from open spout 42 as the opening is less prone to closing up on itself. Furthermore, the offset radius of curvature shifts the opening created by spout 42 downwardly towards the pourable product, making the product more flowable from the bag. Advantageously, this design results in an opening at spout 44 that has a cross-sectional area of from about 4 in 2 , to about 31 in 2 , preferably from about 9 in 2 to about 28 in 2 , and more preferably from about 13 in 2 to about 19 in 2 . This design yields a bag that can be emptied 15-20% more quickly than prior art bags.
[0038] As was true with bag 10 , perforation 44 of bag 10 a also preferably includes a “starter split” 43 through first horizontal seam 30 . Starter split 43 is an area of weakness that renders perforation 44 easier to tear. Unlike prior art bags, starter split 43 is actually present within first horizontal seam 30 so that the seam 30 does not hinder tearing due to inherent perforation weakness.
[0039] The bag 10 a further comprises a second set of perforations 52 in front and back panels 12 , 14 . Perforations 52 provide an area where the front and back panels 12 , 14 can be separated, creating an alternative, or additional, opening for pouring of product from the bag 10 a . Ideally, perforations 52 form a pattern that is linear in nature, and substantially parallel to outermost edges 24 a , 24 b and substantially perpendicular to outermost edges 24 c , 24 d . The figures depict perforations 52 extending from outermost edge 24 c to outermost edge 24 d , however, in some embodiments, the perforations 52 do not extend entirely across the width “W” of the front and back panels 12 , 14 . However, it is preferred that the perforations 52 extend at least about 50% of “W,” preferably at least about 75% of “W,” and more preferably about 100% of “W.” Furthermore, although the figures show the perforations 52 at a distance “D” from outermost edge 24 b , it will be appreciated that the perforations 52 can be positioned anywhere along the length “L 1 ” of the front and back panels 12 , 14 , provided perforations 52 are at least about 0.5 inches, and preferably at least about 1 inch, from first horizontal seam 30 and outermost edge 24 b . The second set of perforations 52 provide a “total dump” option to the user, when a spout 42 is not needed or desired.
[0040] The bag 10 a also preferably has a side panel 54 . Side panel 54 is essentially a lay-flat fold whose width is defined by a turn axis 56 . Side panel 54 allows for expansion of the bag upon filling with the pourable product.
[0041] Referring to FIG. 6 , several dimensions of the inventive bag 10 a have been defined. The ranges for those dimensions are shown in Table 2.
[0000]
TABLE 2
Preferred Bag Dimensions
Dimension
Broad Range
Preferred Range
Most Preferred Range
from FIG. 3
(inches)
(inches)
(inches)
L
about 20 to about 35
about 24 to about 30
about 26 to about 28
W
about 10 to about 24
about 14 to about 20
about 15 to about 18
D 1
about 5 to about 8
about 5.5 to about 7.5
about 5.8 to about 7
D 2
about 4.5 to about 7
about 5 to about 6.5
about 5 to about 6
D 3
about 2 to about 3.5
about 2.2 to about 3
about 2.4 to about 2.8
D 4
about 2.5 to about 5.5
about 3 to about 5
about 3.7 to about 4.5
D 5
about 2 to about 4
about 2.5 to about 4.5
about 2.9 to about 3.2
D 6
about 0.25 to about 2
about 0.75 to about 1.25
about 1
D 7
about 0.1 to about 0.75
about 0.2 to about 0.5
about 0.375
D 8
about 0.5 to about 10
about 2 to about 8
about 4 to about 7
L 1
about 17 to about 30
about 20 to about 28
about 22 to about 26
D 1 /D 2 **
about 0.8 to about 1.7
about 1 to about 1.5
about 1.1 to about 1.3
L/D 1 **
about 2 to about 5
about 3 to about 4.5
about 3.5 to about 4
W/D 2 **
about 1.5 to about 5
about 2 to about 4
about 2.5 to about 3
L 1 /D 8 *
about 2 to about 15
about 2 to about 10
about 3 to about 7
**Unitless
[0042] As was true with the first embodiment (bag 10 ), the inventive bag 10 a can be manufactured by various methods, but the preferred method is described herein. First, a tube or sleeve of plastic is cut to the desired length (represented by “L” in FIG. 6 ). The plastic of which the inventive bag is formed can be any material typically used to form bags carrying bulk products. The plastic should be flexible and stretchable so that the bag collapses as the bulk product is poured from the bag. Preferably, the plastic of which the bag is formed stretches from about 1 to about 2 times at yield, and more preferably about 1.5 times at yield. Furthermore, it is preferred that the bag be formed of a plastic that stretches at least about 4 times, preferably at least about 5 times, and more preferably from about 5 to about 7 times at its break point. Thus, the preferred plastic has an ASTM D882 percent elongation of from about 200% to about 800%, preferably from about 400% to about 700%, and more preferably from about 500% to about 650%. The thickness of the preferred plastic is from about 2 mil to about 14 mil, preferably from about 4 mil to about 10 mil, and more preferably from about 6 mil to about 8 mil. The most preferred material is LLDPE.
[0043] A heat seal is then applied at first end portion 16 in order to form horizontal seam 30 . A film (typically having a 10-mil thickness) is heat-sealed to flap 32 to form patch 36 . C-shaped grip 38 is then cut (e.g., die-cut) through the patch 36 and flap 32 , thus forming handle 34 , which serves as the primary carrying handle. The perforations 44 and 52 can be added at this time according to conventional methods.
[0044] The manufactured bag can then be stored until needed, or immediately filled and sealed. Either way, after the bag 10 a is filled to the desired level, a final heat seal is applied at second end portion 18 to create second horizontal seam 58 , making the filled bag 10 a ready for distribution. It will be appreciated that the inventive bag 10 a can be used to transport and store numerous types of pourable products, including cubes, pellets, tablets, powders, compacted pieces, and/or granules of those selected from the group consisting of: salt (e.g., water softening, pool treatment, deicing, etc.); animal food (e.g., bird seed, grain, dog or cat food); bulk flour or sugar; cement; seed (e.g., grass seed) and other lawn and garden products; fertilizers; ice; sand; rice; spices; soil (including soil mixtures); pesticides (e.g., fire ant treatments); industrial chemicals; mortar; plaster; marble dust; stones (including pebbles and gravel); and constructions products. Such products will typically cause the bags to weigh from about 20 lbs. to about 100 lbs., and more typically from about 40 lbs. to about 60 lbs.
[0045] It will be appreciated that the present invention provides the user for more than one option for removing the product from the bag. In use and before pouring, one option allows a user to tear corner 28 a at perforations 44 in order to remove (or at least partially remove) corner 28 a at spout 42 . This forms an opening at spout 42 , rendering spout 42 ready for pouring. This controlled pouring allows for fairly exact dispensing of the product, while preventing spillage and waste of the product.
[0046] Another option allows a user to tear the front and back panels 12 , 14 at perforations 52 in order to separate (or at least partially separate) strip 60 from the remainder 62 of bag 10 a . It will be appreciated that this allows for easy pouring of the product from the bag 10 a . This controlled pouring allows for fairly exact dispensing of the product, while preventing spillage and waste of the product. This type of opening is particularly advantageous in situations where the bag is being poured into a large opening. The user can just lay the bag on top of the large opening and use both hands to tear perforations 52 and separate strip 60 from remainder 62 , thus avoiding the need to hold and tilt a heavy bag during product removal.
[0047] As yet a further option, the user could tear both the perforations 44 and the perforations 52 to form two openings, and use both openings to remove the product from the bag. It will be appreciated that these options allow the end user to select the best option for his/her particular use, environment, strength, etc.
[0048] Regardless of whether the inventive bag is provided as bag 10 or bag 10 a , it should include a number of features and properties that give it advantages over the prior art. For example, perforations 44 and 52 should tear easily at the time of use, but at the same time should be sufficiently strong that they do not tear before desired, thus allowing spilling of the product.
[0049] Additionally, the inventive bags 10 , 10 a must be sturdy enough not to be damaged upon dropping. More specifically, the bags 10 , 10 a should pass a six-sided drop test.
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A novel bag for holding, transporting, and pouring a bulk product is provided. In one embodiment, the bag comprises a curved, perforated section at one corner. The section can be removed by tearing along the perforation, thus forming a spout for pouring the product from the bag. In another embodiment, the bag further comprises a second perforated section extending the majority of the way (and preferably the entire way) horizontally across the bag. In this embodiment, the bag could alternatively, or additionally, be opened by tearing along the second set of perforations and separating the resulting two sections of the bag. The bag is typically formed of plastic, and can be used for salt, animal food, and other pourable products.
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FIELD OF THE INVENTION
The present invention relates to suspension assemblies for tracked vehicles.
BACKGROUND OF THE INVENTION
Conventionally, the rear suspension of a snowmobile supports an endless track that is driven by the engine to power the snowmobile. The endless track is tensioned to surround a pair of parallel slide rails, a plurality of idler wheels, and at least one drive wheel or sprocket. A shock absorbing mechanism involving compressed springs and hydraulic dampers urges the slide frame assembly away from the chassis (also known as a frame) of the snowmobile against the weight supported above the suspension in a static condition.
When a snowmobile is driven in reverse, particularly on soft snow, the rear portion of the track can dig into the snow and cause the vehicle to become stuck. Traditionally, the rear suspensions of utility snowmobiles are provided with a rear articulated portion that can pivot upward against a biasing force when sufficient force is applied to that portion of the rail. The articulation of the rear portion provides a ramp so that when the vehicle is reversing in soft snow, the vehicle is continuously being pushed to the top of the snow and prevents the snowmobile from becoming stuck.
The magnitude of the biasing force is adjustable, so that the suspension system can be adapted to different types of terrain. Softer snow generally requires a smaller biasing force, so that the articulated portion can be pushed upward by the reduced force that is exerted by the softer snow. Harder snow generally requires a greater biasing force, so that the articulated portion can assist in providing improved traction.
FIG. 1 illustrates the rear portion of a prior art rear suspension system 10 . The forward direction of travel of the vehicle is indicated by the arrow. The suspension system 10 includes a slide frame assembly 12 consisting of two generally parallel slide rails 14 and a plurality of wheels 16 . The slide frame assembly 12 defines a path over which an endless track (not shown) travels to propel the vehicle. An articulated portion 18 is connected to the slide frame assembly 12 so as to allow the articulated portion 18 to pivot about an axis 20 . The articulated portion 18 has two extension arms 22 and a number of idler wheels 24 . The idler wheels 24 serve to further define the path for the endless track.
The articulated portion 18 is biased in a lowered position by a pair of Belleville springs 26 , each consisting of a stack of Belleville washers 28 . When the vehicle is operated in the reverse direction, forces exerted on the articulated portion 18 can cause it to pivot to a raised position, thereby compressing the springs 26 . The biasing force of the springs 26 can be adjusted by tightening or loosening the nuts 30 so that the springs 26 are more or less compressed when the articulated portion 18 is in the lowered position.
While this assembly works, it presents a number of disadvantages. Adjusting the biasing force by using the nuts 30 to compress the springs 26 is time-consuming and difficult, making it inconvenient for a rider to make adjustments “on the fly” as he encounters different terrain. It is also difficult to calibrate the two springs 26 such that they provide the same degree of biasing force.
In addition, in certain situations the rider may desire the articulated portion 18 to remain in the lowered position, for example while using the snowmobile to tow heavy loads in the forward direction. If the articulated portion 18 is in the lowered position, a greater length of track is in contact with the ground, resulting in increased traction and improved towing performance. The only way to cause the articulated portion 18 to remain in the lowered position is to substantially fully compress the springs 26 such that they permit little or no upward pivoting of the articulated portion 18 . Compressing the springs 26 to this degree requires exerting more torque on the nuts 30 than a person can comfortably exert, so a rider attempting to do so will generally not succeed in fully compressing the springs 26 . Because the springs 26 can still be further compressed if a sufficient force is exerted on them, this method will not always maintain the rear portion 18 in the lowered position, resulting in reduced traction on harder terrain. In addition, once an attempt has been made to tighten the springs 26 to this degree, restoring the springs 26 to their previous degree of bias requires re-calibrating the two springs 26 , with all the attendant difficulties noted above.
In recent years, some all-terrain vehicles (ATVs) have been equipped with endless track drive systems to adapt them for use in snowy conditions. Thus, ATVs could also benefit from improvements in suspension assemblies for tracked vehicles.
Therefore, there is a need for an improved suspension system for tracked vehicles with an articulated rear portion that is biased toward a lowered position and that has an adjustable biasing force.
There is also a need for an improved suspension system for tracked vehicles with an articulated rear portion that is biased toward a lowered position and that can be conveniently locked in position.
SUMMARY OF THE INVENTION
It is an object of the present invention to ameliorate at least some of the inconveniences present in the prior art.
It is also an object of the present invention to provide a suspension system for a tracked vehicle with an articulated rear portion that is biased toward a lowered position and that has an adjustable biasing force.
It is also an object of the present invention to provide a suspension system for a tracked vehicle with an articulated rear portion that is biased toward a lowered position and that can be locked in position independently of the magnitude of the biasing force.
One aspect of the present invention provides a suspension assembly for a vehicle having a chassis and an endless drive track. The suspension assembly comprises a suspension arm having a first end and a second end. The first end of the suspension arm is pivotally connectable to the chassis. A slide frame assembly is pivotally connected to the second end of the suspension arm. At least one shock absorber assembly is pivotally connected to the slide frame assembly. The at least one shock absorber assembly biases the slide frame assembly away from the chassis. The suspension assembly comprises a rail extension assembly comprising at least one extension arm. The at least one extension arm has a front end. The front end of the at least one extension arm is pivotably connected to a rear portion of the slide frame assembly about a first axis. The rail extension assembly is pivotable between a raised position and a lowered position with respect to the slide frame assembly about the first axis. At least one rear idler wheel is pivotably connected to a rear portion of the rail extension assembly for guiding the endless drive track. At least one adjustment cam is pivotably connected to the rail extension assembly about a second pivot axis. At least one spring abuts against the at least one adjustment cam. The at least one spring biases the rail extension assembly toward the lowered position. The at least one adjustment cam is pivotable about the second axis between a first position and a second position to adjust a magnitude of a biasing force of the spring.
In a further aspect, at least one blocking cam is mounted to one of the slide frame assembly and the rail extension assembly. At least one stopper is mounted to the other of the slide frame assembly and the rail extension assembly. When the rail extension assembly is in the lowered position, the at least one blocking cam is movable between: a first position, where the at least one blocking cam prevents the rail extension assembly from pivoting to the raised position; and a second position, where the at least one blocking cam does not prevent the rail extension assembly from pivoting to the raised position. When the at least one blocking cam is in the second position and the rail extension assembly is in the raised position, the at least one blocking cam abuts against the at least one stopper.
In a further aspect, the at least one blocking cam is mounted to the rail extension assembly and the at least one stopper is mounted to the slide frame assembly.
In a further aspect, the at least one stopper is at least one upper stopper. The suspension assembly further comprises at least one lower stopper mounted to the slide frame assembly. When the rail extension assembly is in the lowered position the at least one blocking cam abuts against the at least one lower stopper.
In a further aspect, the at least one blocking cam comprises two laterally spaced blocking cams. The at least one stopper comprises two laterally spaced stoppers corresponding to the two laterally spaced blocking cams.
In a further aspect, the stoppers are made at least in part from an elastomeric material.
In a further aspect, the second axis is parallel to the first axis.
In a further aspect, the suspension assembly is incorporated in a snowmobile.
Another aspect of the present invention provides a suspension assembly for a vehicle having a chassis and an endless drive track. The suspension assembly comprises a suspension arm having a first end and a second end. The first end of the suspension arm is pivotally connectable to the chassis. A slide frame assembly is pivotally connected to the second end of the suspension arm. At least one shock absorber assembly is pivotally connected to the slide frame assembly. The at least one shock absorber assembly biases the slide frame assembly away from the chassis. The suspension assembly comprises a rail extension assembly comprising at least one extension arm. The at least one extension arm has a front end. The front end of the at least one extension arm is pivotably connected to a rear portion of the slide frame assembly about a first axis. The rail extension assembly is pivotable between a raised position and a lowered position with respect to the slide frame assembly about the first axis. At least one rear idler wheel is pivotably connected to a rear portion of the rail extension assembly for guiding the endless drive track. At least one spring biases the rail extension assembly toward the lowered position by exerting thereon a biasing force. The suspension assembly comprises a first movable member. The first movable member is movable between a first position and a second position to adjust a magnitude of the biasing force. The suspension assembly comprises a second movable member. The second movable member is movable between a first position and a second position to prevent the rail extension assembly from pivoting from the lowered position to the raised position independently of the magnitude of the biasing force.
In a further aspect, the second movable member is at least one blocking cam mounted to one of the slide frame assembly and the rail extension assembly. The suspension assembly further comprises at least one stopper mounted to the other of the slide frame assembly and the rail extension assembly. When the rail extension assembly is in the lowered position, the at least one blocking cam is movable between: a first position, where the at least one blocking cam prevents the rail extension assembly from pivoting to the raised position; and a second position, where the at least one blocking cam does not prevent the rail extension assembly from pivoting to the raised position. When the at least one blocking cam is in the second position and the rail extension assembly is in the raised position, the at least one blocking cam abuts against the at least one stopper.
In a further aspect, the at least one blocking cam is mounted to the rail extension assembly and the at least one stopper is mounted to the slide frame assembly.
In a further aspect, the at least one stopper is at least one upper stopper. The suspension assembly further comprises at least one lower stopper mounted to the slide frame assembly. When the rail extension assembly is in the lowered position the at least one blocking cam abuts against the at least one lower stopper.
In a further aspect, the at least one blocking cam comprises two laterally spaced blocking cams. The at least one stopper comprises two laterally spaced stoppers corresponding to the two laterally spaced blocking cams.
In a further aspect, the stoppers are made at least in part from an elastomeric material.
In a further aspect, the suspension assembly is incorporated in a snowmobile.
For purposes of this application, terms related to spatial orientation or direction such as “forward” and “rearward” should be understood as they would normally be understood by a rider of the vehicle while sitting on the vehicle in a normal riding position.
Embodiments of the present invention each have at least one of the above-mentioned aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attaining the above-mentioned objects may not satisfy these objects and/or may satisfy other objects not specifically recited herein.
Additional and/or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where:
FIG. 1 is a perspective view of a rear portion of a prior art rear suspension system for a snowmobile;
FIG. 2 is a perspective view, taken from a front right side, of a snowmobile having a rear suspension system according to an embodiment of the present invention;
FIGS. 3A to 3C are side elevation views of a rear suspension system for a snowmobile according to an embodiment of the present invention, showing different positions of the rail extension assembly and the blocker cam;
FIGS. 4A and 4B are perspective views of a rear suspension system for a snowmobile according to an embodiment of the present invention, showing different positions of the adjustment cam; and
FIGS. 5A and 5B are side elevation views of the rear portion of a rear suspension system for a snowmobile according to an embodiment of the present invention, showing different positions of the blocker cam.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A rear suspension system in accordance with an embodiment of the present invention will be described with respect to its use in snowmobiles. It is contemplated that the present invention could also be applied to other types of tracked vehicles, such as ATVs that are equipped with tracks to adapt them for use on snowy terrain.
Referring to FIG. 2 , the snowmobile 100 has a front end 102 and a rear end 104 . The snowmobile 100 has a frame including a tunnel portion 106 and an engine cradle portion 108 . An engine 110 (schematically illustrated) is supported by the engine cradle portion 108 . A number of fairings 112 are supported on the frame to provide aesthetic appeal. A seat 114 is provided above the tunnel 106 for accommodating a rider and, optionally, one or more passengers.
A pair of skis 116 at the front end 102 of the snowmobile 100 are connected to the frame via a suspension system 118 . A steering assembly 120 is provided generally forward of the seat 114 , and is connected to the skis 116 in a known manner such that turning the steering assembly 120 turns the skis 116 to steer the snowmobile 100 .
At the rear end 104 of the snowmobile 100 , an endless track 122 is supported by a rear suspension system 124 . The track 122 is partially disposed in the tunnel portion 106 of the frame, and is driven by the engine 110 via a transmission (not shown) to propel the snowmobile 100 .
The rear suspension system 124 will now be described with reference to FIGS. 3A , 3 B and 3 C.
The rear suspension system 124 includes a slide rail assembly 126 . The slide rail assembly 126 includes two parallel slide rails 128 (both shown in FIGS. 4A and 4B ) that generally position and guide the track 122 (schematically shown in FIG. 3A ). The slide rails 128 typically have a curved forward end to follow the track 122 and a flat rear portion to ensure proper traction between the track 122 and the ground. The slide rails 128 typically include a lower sliding surface made of polyethylene to reduce contact friction between the slide rails 128 and the track 122 . One or more pairs of lower wheels 130 and one or more pairs of upper wheels 132 engage the track 122 to further guide the track 122 . One or more idler wheels 134 are supported on a rail extension assembly 136 to further guide the track 122 . The rail extension assembly 136 will be described in further detail below.
The rear suspension system 124 is connected to the tunnel portion 106 via a front suspension arm 138 and a rear suspension arm 140 . The front and rear suspension arms 138 , 140 are pivotally connected to the tunnel 106 at their upper ends, and pivotally connected to the slide rail assembly 126 at their lower ends. Two shock absorber assemblies 142 bias the slide rail assembly 126 downward against the track 122 to ensure proper contact therebetween. It should be understood that alternative rear suspension systems constructed with a single shock absorber assembly 142 or with more than two shock absorber assemblies 142 are also within the scope of the invention.
Referring now to FIGS. 4A and 4B , a rail extension assembly 136 according to an embodiment of the present invention will now be described.
The rail extension assembly 136 has two extension arms 144 that support the idler wheels 134 . The extension arms 144 are connected to the slide rail assembly 126 such that the rail extension assembly 136 can pivot about the pivot axis 146 defined by the cross member 147 of the rail extension assembly 136 . The rail extension assembly 136 can pivot between a lowered position (seen in FIGS. 3A , 3 B) and a raised position (seen in FIG. 3C ). The line L passes through the center of the idler wheels 134 and bisects the angle between the top and bottom track portions 122 extending forward from the rear idler wheels 134 . When the rail extension assembly is in the lowered position, the pivot axis 146 is preferably higher than the line L, to ensure that the forces exerted on the rear idle wheels 134 by the track 122 will tend to force the rear idler wheels 134 towards the ground.
As can be most clearly seen in FIG. 4B , one end of the spring 148 abuts against a cross member 149 of the slide rail assembly 126 and the other end of the spring 148 abuts against the adjustment cam 150 mounted on the cross member 151 of the rail extension assembly 136 . The cross member 151 defines an axis of rotation 160 about which the adjustment cam can be pivoted. In this manner, the spring 148 biases the rail extension assembly 136 downward toward the lowered position.
The adjustment cam 150 has an asymmetric shape, such that some portions of the edge of the adjustment cam 150 are closer to the axis of rotation 160 , and other portions of the edge of the adjustment cam 150 are farther from the axis of rotation 160 . The shape of the cam 150 allows a rider to adjust the magnitude of the biasing force exerted on the rail extension assembly 136 by the spring 148 . If the rider desires a stronger biasing force, he can rotate the adjustment cam 150 so that an external surface of the adjustment cam 150 farther from the axis of rotation 160 abuts against the spring 148 , as seen in FIG. 4B . In this orientation, the adjustment cam 150 increases the compression of the spring 148 , thus increasing the magnitude of the biasing force exerted by the spring 148 . Similarly, if the rider desires a weaker biasing force, he can rotate the adjustment cam 150 so that an external surface of the adjustment cam 150 closer to the axis of rotation 160 abuts against the spring 148 , as seen in FIG. 4A . In this orientation, the adjustment cam 150 partially reduces the compression of the spring 148 , thus decreasing the magnitude of the biasing force exerted by the spring 148 .
The adjustment cam 150 is provided with a lateral extension 152 suitable for being gripped by a wrench or similar tool (not shown), to allow the rider to rotate the adjustment cam 150 about the axis 160 to adjust the biasing force of the spring 148 . The axis 160 is parallel to the axis 146 in this embodiment.
In the present embodiment, a single spring 148 and a single adjustment cam 150 are used. This arrangement allows simple and convenient adjustment of the biasing force because only a single adjustment cam 150 needs to be rotated. It is contemplated, however, that the invention could be practiced with two or more springs 148 , and a corresponding number of adjustment cams 150 . In the case of more than one adjustment cam 150 , the adjustment cams 150 can be mechanically coupled so that rotating one adjustment cam 150 causes the other adjustment cams 150 to rotate as well, thus necessitating only a single rotation to adjust the biasing force of all of the springs 148 .
When the snowmobile 100 is operated in the reverse direction indicated in FIG. 3A , the terrain encountered by the portion of the track 122 in the vicinity of the idler wheels 134 exerts an upward force on the idler wheels 134 . The idler wheels 134 transmit this force to the extension arms 144 , thereby urging the rail extension assembly 136 toward the upward position (seen in FIG. 3C ), at least partially overcoming the downward biasing force exerted by the spring 148 . It should be understood that softer terrain, such as soft snow, will exert less upward force than harder terrain such as packed snow or dirt. Thus, if the rider anticipates using the snowmobile 100 in the reverse direction on soft snow, he can rotate the adjustment cam 150 so that the spring 148 will exert a comparatively weak biasing force that can be at least partially overcome by the comparatively weak upward force exerted on the track 122 by the soft snow. If the rider anticipates using the snowmobile 100 in the reverse direction on harder terrain, or primarily for towing in the forward direction, he can rotate the adjustment cam 150 so that the spring 148 will exert a comparatively strong biasing force, thereby urging the track 122 against the ground with a greater force to provide improved traction.
Referring again to FIGS. 4A and 4B , a pair of blocker cams 154 are provided on opposite sides of the rail extension assembly 136 . The operation of only one blocker cam 154 will be described in detail below, and it should be understood that the other blocker cam 154 operates in substantially the same manner. It is also contemplated that the present invention may be practiced with only a single blocker cam 154 , or with more than two blocker cams 154 .
A lower stopper 156 and an upper stopper 158 are provided on the slide rail assembly 126 in general alignment with the blocker cam 154 . The blocker cam 154 can be rotated about the axis 160 between a blocking position, shown in FIGS. 3A and 5A , and a non-blocking position, shown in FIGS. 3B and 5B . Although in the present embodiment the axes of rotation 160 of the adjustment cam 150 and the blocker cam 154 are coaxial, it should be understood that the two rotate independently, such that the adjustment cam 150 does not rotate when the blocker cam 154 is rotated and vice versa. The adjustment cam 150 and the blocker cam 154 may optionally be arranged such that they rotate about separate axes without departing from the scope of the invention. Thus, the operation of the blocker cam 154 to prevent the rail extension assembly 136 from pivoting to the raised position, which will be described in further detail below, is independent of the magnitude of the biasing force of the spring 148 .
In FIGS. 3A , 3 B, 5 A and 5 B, the rail extension assembly 136 is shown in the lowered position. In this position, the blocker cam 154 abuts against the lower stopper 156 to prevent the rail extension assembly 136 from pivoting further downward to a position lower than the slide rails 128 , regardless of the position of the blocker cam 154 .
When the rail extension assembly 136 is in the lowered position, the blocker cam 154 can be used to prevent the rail extension assembly 136 from pivoting to the upper position. Referring to FIGS. 3A and 5A , the blocker cam 154 is shown in the blocking position. The blocker cam 154 abuts against the upper stopper 158 to limit upward movement of the rail extension assembly 136 and prevent the rail extension assembly 136 from pivoting to the upper position shown in FIG. 3C even when an upward force is exerted on the rail extension assembly 136 by the terrain. This provides increased traction when desired by the rider.
Referring to FIGS. 3B and 5B , when the blocker cam 154 is in the non-blocking position, the blocker cam 154 is spaced away from the upper stopper 158 . In this configuration, the rail extension assembly 136 is able to pivot to the raised position shown in FIG. 3C , when an upward force on the rail extension assembly 136 is strong enough to overcome the downward biasing force of the spring 148 . In the raised position, the blocker cam 154 abuts against the upper stopper 158 to limit further upward movement of the rail extension assembly 136 . When the rail extension assembly 136 is in the upward position, the angle of the track 122 provides a ramp such that the track 122 will maintain or pull the snowmobile 100 on top of snow and other obstacles, and prevent the snowmobile 100 from becoming stuck.
The lower stoppers 156 and the upper stoppers 158 are preferably coated with a resilient material, such as rubber, to cushion the impacts of the blocker cam 154 thereon while the snowmobile 100 is in operation.
Modifications and improvements to the above-described embodiments of the present invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims.
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A suspension assembly for a vehicle having an endless drive track is disclosed. The suspension assembly has a slide frame assembly and a rail extension assembly pivotably connected to a rear portion of the slide frame assembly and pivots about a first axis. The rail extension assembly is pivotable between a raised position and a lowered position with respect to the slide frame assembly. A spring biases the rail extension assembly toward the lowered position. The magnitude of the biasing force of the spring is adjustable. The rail extension assembly can be prevented from pivoting from the lowered position to the raised position independently of the magnitude of the biasing force.
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ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contrast and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
BACKGROUND OF THE INVENTION
The present invention relates generally to improvements in solar energy collection systems and more particularly pertains to new and improved sun-tracking solar energy collection systems that are capable of producing high solar energy concentration ratios.
The overriding problem confronting developers of solar energy power systems has been the problem of producing the required high temperatures at a cost that would make the utilization of solar power competitively attractive. Presently, systems capable of producing the required high temperatures directly from solar energy, utilize tracking devices with large moving primary reflectors. Accurate tracking devices, however, are expensive to construct and costly to maintain if they are to track under conditions of weather extremes and varying high wind forces. The cost of producing large tracking reflectors and the costs of an associated tracking mechanism sturdy enough to withstand expected wind forces make a solar energy heat generating plant that can provide sufficient power to produce electricity in the multi-megawatt range an uneconomical prospect.
Solar energy collection systems that are to be used for producing superheated steam for use by steam-driven generator equipment for generating electric power must be capable of transforming solar energy into thermal energy in the range of 1000° F or higher. The prior art systems capable of such heat generation involve tracking concentrators such as three-dimensional paraboloidaldishes which can be precisely steered in both altitude and azimuth to follow the sun's movement. In order to generate temperatures in the range of 1000° F in sufficient quantity for use as energy for the generation of electrical power, literally thousands of 20-foot diameter, three-dimensional parabolic dishes must be utilized. The cost of producing large numbers of such optically finished compound curve reflecting surfaces that are sturdy enough to hold their figure when tilted and turned in the wind is prohibitive.
OBJECTS AND SUMMARY OF THE INVENTION
An object of this invention is to provide an inexpensive, high temperature solar energy collection system.
Another object of this invention is to provide a tracking solar energy collection system utilizing a fixed, linear, ground-based primary reflector and a movably supported collector.
A further object of this invention is to provide secondary reflectors for refocusing the solar energy reflected from a fixed concentrator into concentrated beams of solar energy.
Yet another object of this invention is to provide secondary reflectors that substantially increase absorption of visible light and reduce emission of heat rays from the collector.
Still another object of this invention is to provide a process for relatively inexpensively making a large linear fixed primary reflector for tracking solar energy collection systems.
Still a further object of this invention is to provide a large-scale solar power system that is sufficiently efficient and cost effective to be competitively attractive.
These objects and the general purpose of this invention are accomplished in the following manner. A large fixed primary reflector is constructed at ground level by slip-forming in concrete or stabilized dirt a trough with a segmented one-dimensional circular cross-section profile. This profile is covered with an inexpensive light-reflective material. The axis of the primary reflector is optimally aligned with respect to the sun path in the area. A heat-absorbing structure is movably supported above the primary reflector. The support mechanism transversely shifts the heat-absorbing structure to track the changing position of the sun's image diurnally and seasonally, keeping the structure at the changing line focus of the primary reflector. The heat-absorbing structure carries secondary reflectors that either direct off-angle solar energy to the structure or refocus the line focus of the primary reflector into discrete spots of intense solar energy. These secondary reflectors are constructed so as to maximize absorption and minimize heat emission from the heat-absorbing structure. Building the solar energy collection system in stages, each stage designed for optimum efficiency within a certain temperature range, provides a more efficient and cost-effective overall system.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like-reference numberals designate like parts throughout the figures thereof and wherein:
FIG. 1 is a block diagram of a staged solar energy collection system;
FIG. 2 is a perspective, partial section, illustrating a solar energy collection system according to the present invention;
FIG. 3 is a perspective, partial section, illustrating a solar energy collection system according to the present invention;
FIG. 4 is a diagrammatic illustration, useful in explaining the principle of the large-scale primary reflector of the present invention;
FIG. 5 is a diagrammatic illustration, useful in explaining the desired structure of the large-scale primary reflector of the present invention; FIG. 6 is a diagrammatic illustration of the daily and seasonal adjustments required by the collector system of the present invention;
FIG. 7 is a partial perspective illustration of a type of laterally movable collector system and a cross section of the largescale reflector of the present invention;
FIG. 8 is a diagrammatic illustration of one type of laterally movable supporting structure for the collectors of the present invention;
FIG. 9 is a schematic illustration of the operation of the laterally movable supporting structure of FIG. 8;
FIG. 10A is a perspective illustration of a secondary reflector of the present invention;
FIG. 10B and 10C are cross-sectional illustrations of other embodiments of the secondary reflectors of the present invention;
FIG. 11 is a cross-sectional illustration of a two-dimensional secondary reflector;
FIG. 12 is a cross-sectional illustration of a two-dimensional secondary reflector utilizing retroreflector means;
FIG. 13 is a perspective illustration of a refocusing secondary reflector of the present invention;
FIG. 14 is a perspective illustration of an alternate embodiment of a refocusing secondary reflector of the present invention;
FIG. 15 is a cross-sectional view of an alternate embodiment of a secondary reflector;
FIG. 16 is a diagrammatic illustration of a surface treatment to be used with the secondary reflector of FIG. 15;
FIG. 17 is a diagrammatic illustration of a surface treatment to be used with the secondary reflector of FIG. 15;
FIG. 18 is a top plan illustration of the piping network used with the solar energy collection system shown of FIG. 3;
FIG. 19 is an end view section of one embodiment of an absorber pipe used in the network of FIG. 18;
FIG. 20 is front view section, partially broken away of the absorber pipe of FIG. 19;
FIG. 21 is an end view section of another embodiment of an absorber pipe used in the network of FIG. 18;
FIG. 22 is a front view section, partially broken away of the absorber pipe of FIG. 21;
FIG. 23 is an end view partial section of the absorber pipe of FIG. 21 illustrating internal structural detail;
FIG. 24 is a front view section, partially broken away, illustrating the internal structural details of the absorber pipe of FIG. 23;
FIG. 25 is a schematic illustration of the laterally movable supporting structure of FIG. 3;
FIG. 26 is a block diagram of an alternate embodiment of a staged solar energy collection system utilizing the solar energy collection system of FIG. 3 and its components as illustrated in FIGS. 18, 19, 20, 21, 22, 23, 24, and 25.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A cost-effective solar energy collection system for use with steam driven generator equipment for producing electric power is illustrated in FIG. 1 as consisting of various temperature stages, each temperature stage comprising structure that is most efficient at that temperature range. The first temperature stage 12 of the system is preferably a solar pond. Solar ponds are well known. An example of a superior solar pond can be found in copending patent application U.S. Ser. No. 590,975 filed on June 27, 1975 for Solar Pond by Charles G. Miller and James B. Stephens. The function of the solar pond is to raise the temperature of cold (40°-70° F) water to a temperature of 200° F. By any well known and convenient means, the 200° F water is transmitted over interconnect 14 to a line-focus secondary reflector tracking system 16, of the type more fully described herein.
The line-focus secondary reflector tracking system 16 would raise the temperature of the received 200° F water to approximately 600° F. This 600° F steam is then supplied, by way of interface 18 to a spot-forming focus secondary reflector tracking system 20, of the type more fully described hereinafter. The spot-forming focus tracking system 20 of the type described herein would raise the temperature of the 600° F received water to approximately 800° F. The 800° F fluid may be raised to even higher temperatures by a three-dimensional tracking parabolic dish system 24, such as is well known in the art. The parabolic dish system 24 receives the 800° F fluid over interface 22 and raises its temperature to approximately 1300° F. This 1300° F superheated fluid may then be supplied by way of interface 26 to generator equipment for use in the generation of electricity.
One embodiment of a tracking solar energy collection system according to the present invention is illustrated in FIG. 2. The ground-based reflector 11 can be made up of a plurality of identical sections 13, 15, each section having its own fluid-carrying vessel 87, 89, respectively, for collecting the solar energy reflected from the respective modular surfaces 13, 15. The width of each modular section is preferably within the capability of present day concrete road laying machinery.
The sawtooth segments 25, 23, 17, 21, 22, 27, and 29 will make up one module 13 that can be laid by a process that utilizes standard highway construction or airstrip construction methods. One example of how the primary reflector modules may be formed follows. A sifter mechanism mounted on wheels having a width equal to or slightly greater than the width of a primary reflector module is utilized. This sifter mechanism may have the following structure. A sifter body is divided into multiple segments, each segment utilizing a rotary screen type mechanism for accepting a different particle size. Conveniently, four segments of the following particle grades may be used: rocks, coarse, medium and fine. The aggregate containing all these grades of particles is supplied to the sifter by a conveyor mechanism, the aggregate being inserted at the "fine" end of the sifter. The entire sifter mechanism moves in a direction whereby its coarse segment is always in the front. Consequently the rocks or very large particles are laid down first, then the coarse particles, then the medium particles, and then the fine particles.
This aggregate material may be the in-situ soil. Or, if the in-situ soil is unsuitable, suitable material may be brought in. As the aggregate is being delivered to the sifter a binder material such as cement is mixed in with it. Consequently all the various graded particles will be associated with the binder. As each graded particulate is ejected from the sifter, it is sprayed with water.
The moistened particulate of each graded layer is partially shaped to the desired contour of the primary reflector by a screed attached to the moving sifting mechanism for each. A plurality of pipes 62 in FIG. 2, having orifices therein, are preferably laid into the multi-layer substrate thus formed in the medium or fine layers.
The multi-layered substrate having binder material throughout is finished to the desired sawtooth segmented cross-section by a roller mechanism that preferably has the following structure. A roller having the inverse curvature of the desired profile and being the width of a primary reflector module travels along the graded aggregate substrate in front of a sled having the same contour as the roller. The sled has mounted thereon acoustic vibrators that operate at high frequency to provide a very smooth surface to the sawtooth segmented primary reflector. The depth of the various segmented steps with varying radii of curvatures 25, 23, 17, 21, 22, 27, and 29 is determined mainly by the slump factor of the thus stabilized soil during its curing process.
An aluminized mylar sheeting material, 0.00025 inches thick, or equivalent reflective material is laid over the slip-formed profile. The reflecting material is held down by a slight vacuum created at the surface of the reflector profile by drawing a vacuum on the pipes laid therein. Since concrete is a porous substance, drawing a vacuum on the pipes within the concrete will create a low pressure region at the surface of the concrete. This will hold the reflective film material in place without the necessity of glue or some other such fastening means. Holding the reflector covering in place by a vacuum also facilitates rapid replacement of torn or dirty reflector material. A vacuum level which varies in intensity suitable to the prevailing wind velocity is preferred. An inexpensive method of producing the vacuum is by steam ejection, using the steam supplied by the system.
Each segmented module of the reflector, such as module 13 has a flat section 31 which can provide access to the curved reflector segments for maintenance and inspection purposes, using a gantry-type vehicle. One type of support structure that may be used comprises a plurality of stanchions 51, 53, 55 equidistantly spaced along a line parallel to the longitudinal axis of each reflector module of the reflector 11. The stanchions 51, 53, 55, for example have a four-bar linkage 75, 77, 79, respectively, attached thereto which supports the fluid-bearing pipe 87. A hydraulic or electrical actuating device of well-known construction 63, 65, 67 is respectively located on the stanchions 51, 53, 55 for moving the four-bar linkages 75, 77, 79 in synchronism. This synchronous movement of the linkage causes the fluid-bearing pipe collector 87 to be transversely shifted in an area relative to the reflecting module 13. The movement of the pipe collector can be controlled either by a programmed source correlated to stored data relating to the apparent sun movement in the area, or alternatively by sun sensing and following systems similar to that used for altitude control on spacecraft.
Every other module of the reflector 11 is similarly constructed. Each module, such as module 15, for example, has a flat walkway portion 33 in which the plurality of stanchions 57, 59 and 61 are placed. These stanchions support respective four-bar linkages 81, 83 and 85. Each bar linkage supports a portion of the fluid-carrying pipe 89 which is moved transversely in an arc by actuation of motive means 69, 71 and 73 respectively connected to the bar linkage devices. The cylindrical segments 40, 41, 35, 37, 36, 43, and 45 of the reflector module 15 may have the same radius of curvature as the segments 25, 23, 17, 21, 22, 27 and 29, respectively of module 13.
These optimum width modules of the reflector surface 11 may be laid side by side, in the manner illustrated in FIG. 2, for any desired distance. The length of each reflective module, along the longitudinal axis, may also be any length desired. It is envisioned that a reflector surface a mile square could be utilized in a staged solar energy collection system used to generate sufficient heat for a 100 megawatt power plant.
The height of the stanchions for each reflector module depend upon the radius of curvature of the troughs, as will be more fully explained hereinafter. The radius of curvature of the troughs depend upon the width of each module. The depth depends on the slump factor limitations of the stabilized soil or concrete used to form the primary reflector profile. This will also be more fully explained hereinafter.
An alternate and preferred support structure for high temperature reflector sections according to the instant invention comprises the use of a single rigid assembly for the absorber pipes, and utilizing inlet and outlet manifolds, thereby eliminating the requirement of high pressure and rotary slip-joints, as will be seen hereinafter.
A variation of the stanchions of the type shown in FIG. 2, is shown in FIG. 3. A plurality of upright support members 28, 30 are provided for each primary reflector module. Each upright support member supports at least a pair of transverse support members 34, 36, 38, 40, 42, and 44. Transverse support members 34, 38, and 42 are located at a first level. Transverse support members 36, 40, and 44 are located at a second higher level.
Four-bar linkages 46 are suspended from the transverse support members at appropriate locations. Each four-bar linkage is moved by actuating devices 32 as described hereinabove. Each four-bar linkage fastens to and supports a secondary reflector mechanism 48 that swings in an arc and pivots about its central axis as the four-bar linkages are moved. Exactly how this is accomplished will be more fully explained hereinafter.
Each secondary reflector mechanism 48 supports an absorber pipe 50 that carries a heat-absorbing fluid. The exact structure of the absorber pipe will be more fully explained hereinafter. Each absorber pipe 50 in each secondary reflector 48 is connected to the other pipes 50 by an inlet manifold 54 and an outlet manifold 56, for supplying a cool heat-absorbing fluid and removing the hot heat-absorbing fluid, respectively. The absorber pipes are connected to the manifolds by high-pressure joints 52, thereby forming a rigid network that moves in unison as the four-bar linkages are caused to move.
It is well known in the art, that a parabolic reflecting trough focuses received parallel light rays, (that arrive in a direction such that a plane perpendicular to the directrix sheet contains the light rays in question,) into a line focus along a line parallel to the vertex line and passing through the axis. If the received light rays, arriving parallel at a parabolic trough, arrive in such a direction that they make an angle with the above-mentioned plane perpendicular to the directrix sheet, the line focus suffers from coma and the focus becomes diffuse. It is for this reason that parabolic trough reflectors must be guided so that they always face the incoming sunlight squarely.
It is possible to achieve many of the results of the tracking parabolic trough, with a non-tracking reflecting trough if the cross-section is made to be circular. Cylindrical reflecting surfaces of circular cross section approximate the parallel line focusing action of an optimally-positioned parabolic cylinder, if only small segments of the circular cylinder surfaces are utilized. Incoming parallel light is brought to a substantial line focus for most angles of approach of the sunlight to the circular trough, albeit the location of the line focus varies with the angle of approach of the sunlight.
FIG. 4 illustrates a circular trough 92 receiving a plurality of differently angled parallel light beams. If only a small segment of the circular trough 92 is considered, such as segment 94, for example, parallel light rays 97A, 95A, 93A impinging upon the segment are reflected at the surface of the radius of curvature with an angle of incidence that equals the angle of reflection. As a consequence, rays 93A, 95A and 97A are reflected as rays 93B, 95B and 97B. These rays intersect at a point 105 lying on the focal surface 109. Rays 99A, 101A and 103A of the cylindrical segment 94 are reflected as rays 101B 103B and 99B that intersect at a point 107 on the focal surface 109. Other skewed light rays, such as rays 116A for example would impinge upon the cylindrical surface 92 and be reflected in a direction 116B, and so on. The focal point 105 for parallel lines 95A, 97A, 93A, and the focal point 107 for parallel lines 101A, 103A and 99A turn into focal lines that run parallel to the longitudinal axis of the cylindrical trough when sheets of light rays parallel to 99A, 101A and 103A but extending into and out of the paper are considered. The focal surface 109 therefore becomes a cylindrical focal trough.
Because a shallow reflecting surface is desired from the standpoint of economy in construction and maintenance, the maximum height 111 to which any reflecting surface may peak should not exceed approximately 12 inches. This problem can be overcome by segmenting the cylindrical surface 92 into a sawtooth-like reflecting surface. Thus, for example, segment 119 is the segment 117 of the cylindrical surface 92 brought down to lie on a common plane with segment 94. Likewise, segment 115 is segment 113 of the cylindrical surface 92 brought down to lie on the same common plane. These segments all have a common height 111.
This segmented reflecting surface, however, will not function to focus parallel lines into a line focus on the surface of focal trough 109. Although the radius of curvature of the various segments are the same as the radius of curvature of the cylindrical trough 92, the distance from the center of curvature of the cylindrical trough 92 varies for each segment. As a consequence, ray 116A, for example, will be reflected from surface segment 115 along reflected light beam 118B. Light beam 116A travels an extra distance 118A before it strikes a reflecting surface 115. The focal point for all parallel light rays striking reflective surface 115 will lie at point 122 which is on a different focal surface of curvature 120 than the focal surface 109 of cylindrical surface 92. Each segmented radius of curvature such as 119 for example may well have a different focal surface.
In order to provide a segmented one-dimensional linear reflecting element that is within the range of 4 to 12 inches in height, the radius of curvature of the various segments must be chosen so that no matter which segment of the equivalent flattened reflective surface 119, 94 and 115, for example, is impinged upon by parallel light rays, these light rays will intersect in the surface of a common focal surface. FIG. 5 illustrates how the radius of curvatures for the various segments of the reflector 123 are determined. The largest segment 125 of the reflecting profile 123 is chosen to have a radius of curvature (r a ) 127 that, for example, is 10 to 20 feet, this distance being a practical distance for the height of the stanchions. Conceivably, higher stanchions feet goes up considerably.
Having determined the radius of curvature for the main segment from cylindrical center of curvature 145 to be approximately 20 feet, the focal surface 131 is located 10 feet, from the surface of segment 125. This focal surface distance is equal to half the radius of curvature (1/2)r a . The radii of curvature of the other segments such as 133 and 139, for example, must then be chosen so that the distance from their surface to the chosen focal surface 131 is equal to half of their radius of curvature. Segments 133, as shown in FIG. 5 can be seen as having a radius of curvature 135, termed r b extending from a center of curvature 147.
The location of point 147 is chosen so that the distance from surface 133 to point 147 is twice the distance from surface 133 to the selected focal surface 131. For this reason, the focal surface of segments 133 will be located on a cylinder with its center at point 147 and having a radius (1/2)r b . From the geometry, the focal surface of segments 133 will be almost exactly coincident with focal surface 131, the focal surface for segment 125. Therefore, an absorber pipe travelling along focal surface 131 and receiving reflected energy from segment 125, will, at the same location, receive energy reflected from segments 133.
In a similar fashion, segments 139 are given a radius of curvature r c , extending from a point 149. The location of point 149 is chosen so that the distance from segment surface 139 to the earlier-selected focal surface 131. Therefore, the focal surface of segments 139 will be located on a cylinder having its center at point 149 and a radius of (1/2)r c . Thus, the focal surface of segments 139 will be almost exactly coincident with focal surface 131, the focal surface of segments 126.
By choosing the radius of curvature of the various segments in the trough reflecting surface 123 in this manner, a reflecting surface that effectively functions like the deep trough 117 of FIG. 4, but is actually shaped as shown at 123 in FIG. 5, is obtained. The reflector-concentrator cross-sectional profile 123 illustrated in FIG. 5 can be slip-formed according to the process above described. Rather than slip-forming the reflector surface to have straight edges 128, sloping edges 130 at an obtuse angle are formed. The reason for interleaving the segments in this manner is that the area 132 within each valley between the imaginary straight edge 128 and the real sloped edge 130 is not effective as a reflecting surface because of shading by the upper corner of edge 128. As will be more fully explained hereinafter, by choosing the slope of edges 130 carefully, light rays striking those edges can be reflected to the line focus of an adjacent collector.
The orientation of the longitudinal axis of the segmented trough reflector surface will determine the extent of movement required by the collector pipe along the focal surface, in order to track the movement of the sun diurnally and seasonally. An east-west longitudinal axis orientation is the preferred orientation for the reason that a minimum of collector movement will be required. FIG. 6 illustrates the various positions that the collector must take during various times of the day and throughout the year, in order to be at the focal line of the solar energy reflected from the surface 151, at all times. The various segments of the reflector 151 have radii of curvature that will cause a substantial part of the parallel light impinging on most parts of the reflector surface to be reflected to a common point on arc 155.
The longitudinal axis of the reflecting surface 151 is assumed to be oriented in the east-west directon so that the troughs of the reflecting surface are parallel with the east-west direction. Broken line 153 represents the local vertical axis, shown here for purposes of reference. For an example relating to a location at latitude 34° N, a light ray 157A, at an angle of 11° to the local vertical, depicts the angle of incidence of solar energy impinging upon the reflector surface 151 at about 12 noon on June 21, i.e., the summer solstice. This light is reflected by surface 151 as a light beam 157B, and intersects the focal arc 155 at point 165. As the afternoon wears on, the angle with the local vertical increases, causing the reflected light beam 157B to move toward point 161 on the focal arc 155. At approximately 3:00 P.M., the reflected light rays 157B are intersecting the focal arc 155 at point 161. At 9:00 A.M. that same day, the light rays 157A impinging on surface 151 were reflected to cross the focal arc 155 at the same point 161. Thus, in the morning, these reflected rays will move from point 161 on the focal arc 155 towards point 165, and back toward point 161 in the afternoon.
The light ray 159A depicts the solar energy from a noon time sun on December 21. This energy is reflected by surface 151 as light rays 159B to intersect the focal arc 155 at point 179. At about 3:00 P.M., the reflected rays 159B are intersecting the focal arc 155 at point 183. At 9:00 A.M. of that same day, the rising sun causes the reflected beam 159B to intersect the focal arc 155 at point 183. Thus, the sun's movement causes the reflected rays to start at point 183, gradually move to point 179, at noon, reverse itself and go back to point 183.
Segment 193 of the focal arc 155 depicts the swing of the reflected sun's rays during the month of January. At about 9:00 A.M., the reflected light rays cross the focal arc at point 181. During the morning, they move toward point 177 where they cross at noon time. In the afternoon they move back toward 181 where they cross at 3:00 P.M. Segment 191 of focal arc 155 depicts the movement of the reflected sun's rays during the month of February. Intersection 173 is the noon time intersection and intersection 195 being the ±3 hours from noon intersection point. Intersection point 172 of focal arc 155 represents the intersection of the reflected light rays during the month of March. There is minimal movement of the reflected light rays at the equinox date because the sun rises directly in the east and sets directly in the west on this date. The segment 189 of the focal radius 155 represents the movement required during the month of April, intersection point 171 being the noon time intersection point. Intersection point 169 is the ±3 hours from noon intersection point. Segment 187 of focal arc 155 is the movement required during the month of May, intersection point 167 being the noon time intersection point. Intersection point 163 is the ±3 hours from noon intersection point. As already noted, segment 185 of the focal arc 155 is the movement required for the month of June, intersection 165 being the noon intersection point and intersection point 161 being the ±3 hours from noon intersection point.
For the month of July, the reflected sun's rays again move along segment 187 of focal arc 155 as they did in May. In August the reflected sun's rays move along segment 189 of focal arc 155 as they did in April. In September the sun again rises directly in the east and sets directly west as it did in March. In October the reflected sun's rays again traverse segment 191 of focal arc 155 as it did in February. In November the reflected sun's rays again traverse segment 193 of focal arc 155 as it did in January.
In order to track the sun's movements diurnally and seasonally, the collector must traverse the focal arc 155 as the sun moves in the sky. As can be seen from FIG. 5, however, the movement of the collector during each day is quite small. Thus, for example, during December the collector need only move within segment 185. At the equinox dates of March and September, however, the collector pipe is substantially stationary at point 172. By not requiring large transversal movements on a daily basis, the drive mechanism for moving the collector pipe along the focal arc 155 is considerably simplified.
FIG. 7 illustrates one embodiment for suspending the high pressure steel, a heat-absorbing, fluid-bearing collector pipes that are moved to always be at the focal line of the reflected sun's rays. The pipes 201, 217 preferably carry water or other fluid that is heated by the reflected solar energy from the reflecting surface 199. As was explained earlier, the fluid-bearing pipes 201 and 217 must move along the focal arcs 215, 233, respectively, in order to track the sun's movements.
There exists for every set of distance and size relationships between the modules that make up the solar collector, an obtuse angle for the edges 130 of the segments of the primary reflector 199 that is most effective in reflecting the incident light rays to an adjacent collector. For example, an incident light ray 206A hitting segment surface 132 is reflected as ray 206B to collector 201. Because of the obtuse angle of slope of edge 130, the entire surface 132 of that segment is an effective reflector. Light rays, such as ray 208A incident on edge surface 130 are reflected as rays 208B to the collector 217 for the adjacent module. Likewise collector 201 will receive some light rays reflected from the edge surface 130 of its adjacent module.
One parallel line of stanchions would be required for each transversely movable collector pipe. The heat-absorbing pipe 201 is connected to a vertical intake pipe member 205 and a vertical outlet pipe member 203. Water (preferably treated or distilled in liquid, vapor or steam form) is supplied to vertical pipe member 205 from pipe 209 through a high-pressure slip joint 213. Steam from the vertical pipe member 203 is supplied to pipe 207 through a high-pressure slip joint 211. The assembly consisting of pipes 205, 201, and 203 can be seen to make up a trapeze that pivots at slip joints 213 and 211 to swing in the focal arc 215. In order for the pipe 201 to swing along this focal arc 215 the distance from the slip joints to the pipe must be equal to half the focal radius of the basic segment in the reflector surface 199.
As was illustrated in FIG. 2 another parallel line of stanchions may support another fluid-bearing pipe member 217 suspended to swing along the focal arc 233. The vertical inlet pipe 219, the vertical 221 and the heat-absorbing pipe 217 again form a trapeze that swings about the slip joints 229 and 231 that connect the inlet pipe 225 and the outlet pipe 227 to the trapeze assembly. The length of the heat-absorbing pipe assembly is determined by the length of each modular section of the primary reflecting surface. The number of heat-absorbing pipes utilized is determined by the number of modules forming the entire primary reflecting surface.
The structure for supporting the heat-absorbing pipe assembly of FIG. 7, and transversely moving it along the focal arc is illustrated in FIG. 8. A stanchion having an upright member 239 and a slanting member 241 supports a bar linkage arrangement consisting of linkage 247, 249 and 251. These linkages are connected together by pivot joints 263, 261 and are connected to the stanchion member 241 by pivot joints 257, 255. The heat-absorbing pipe 253 is fastened to the bar linkage 251. A secondary reflector 265 may be placed over the pipe. A hydraulic or electric, or other suitable motive means 243 having a transversely movable arm 245 is pivotally connected at a point 259 on bar linkage member 249. The transverse movement of the arm 245, as directed by motive means 243, causes the entire linkage assembly to shift the heat-absorbing pipe 253 along the focal arc of the primary reflecting surface 237.
FIG. 9 more clearly illustrates the movement of the bar linkage mechanism to cause the collector to swing along the focal arc 275. During the winter months the bar linkage of the trapeze assembly is located in the general area of bar link 269 of focal arc 275. The oscillatory motion of the bar linkage will be within the one segment, as described in connection with FIG. 4. During the equinox months, or March and September, the trapeze assembly, consisting of bar links 249, 247, and 251 are located as shown in solid lines. Very little oscillatory motion is necessary during these months. The secondary reflector 267 is angled to receive the reflected solar energy 273 from the primary reflecting surface 237. During the summer months the bar linkage member of the linkage assembly is located in the general area of link 271 on the radial arc 275. The bar linkage will oscillate along the radial arc 275 within the segments described in connection with FIG. 4. It can be seen that although the swings required of the bar linkage from the winter to summer months is great, the daily swing of this linkage is minimal. Thereby, tracking the daily movement of the sun's image requires minimal movement of the trapeze mechanism. As can be seen this trapeze tracking mechanism is relatively small and therefore allows low cost, low maintenance and minimal windage problems.
The reflecting surface of the present invention is not optically perfect. Even if it were, the environmental condition in which it must operate would detract from its optical reflective characteristics in time. This situation will cause the reflected solar energy to scatter somewhat rather than being reflected as a clear, sharp energy beam. In order to gather in as much of this scattered, reflected energy as possible, a two-dimensional secondary reflector 277 such as illustrated in FIG. 10A is placed around the heat-absorbing collector pipe 275. The secondary reflector 277 is shown as being substantially a U-shaped member having straight or angled legs. The closed end of the U-shaped member of the secondary reflector 277 is form-fitted around the heat-absorbing pipe 275. Any solar energy rays falling within the open mouth of the secondary reflector 277 will be substantially directed towards the pipe 275. The preferred material out of which the secondary reflector 277 is made is aluminum, or any equivalent thereof.
FIG. 10B is a cross-sectional view of an alternate embodiment for the secondary reflector in which the angled legs 282 and 284 of the reflector are curved, rather than being straight. The distance between the angled legs 284 and 282 at the open end 285 of the reflector is preferably twice the diameter of the heat-absorbing pipe at the closed end 283 of the reflector. It is conceived that a collector pipe diameter of four inches would be utilized. Therefore, the distance between the curved leg members 284 and 282 would be 8 inches.
In order to retard reradiation and convection heat loss, as a first step for use on the low temperature section, the outside and back of the secondary reflector and the heat-absorbing pipe may be covered with an insulating material, as shown in FIG. 10C. The heat-absorbing pipe 275 carrying the secondary reflector 281 is shown to be completely covered with insulating material 279 that may be magnesia or some such other high temperature insulation. The open end and inside of the field collector are left exposed, to receive the reflected solar energy rays.
The system described so far has a relatively high concentration ratio since it is a tracking trough system and can deliver high heat fluxes to the absorber pipe. As the temperature of the fluid in the pipe rises, it progresses from the inlet end toward the outlet end, the protection afforded by the insulating material around the secondary reflector shown in FIG. 10C becomes inadequate. This is so, because of radiant heat loss and convective heat loss through the unprotected open end of the secondary reflector becomes unacceptably large for high temperature operation.
When dealing with higher temperature sections of the absorber pipe, that is those sections of pipe further from the inlet end and closer to the outlet end, a modification of the secondary reflector becomes economically justified, and is shown in FIG. 12. The secondary reflector of FIG. 12 is compared with the secondary reflector of FIG. 11 which shows the features from which the secondary reflector of FIG. 12 evolved.
FIG. 11, shows a more detailed version of a sophisticated curved-side secondary reflector than that shown in FIGS. 10B and 10C. This secondary reflector functions to focus light entering its mouth 284 having a size d B within its acceptance angle 280 onto the d A length 282 of the collector. This two-dimensional reflector is made up of two parabolically curved sides 288 and 290, chosen so their respective focal points 294 and 292 fall on the corner of the opposite parabolic side.
The relationship of the distance d B across the mouth 284 to the distance d A at the collector 282 is
d.sub.B = d.sub.A √2
for the chosen angular acceptance of 45°.
Thus, if the distance d A is chosen to be approximately four inches, the diameter of the collector pipe, the distance d B across the mouth would be approximately 5.6 inches. The relationship between the two distances d B and d A and the L length 286 of the two-dimensional reflector is:
L = 1/2(d.sub.B + d.sub.A) cot 45°
For d B = 5.6 inches and d A = 4 inches, L is approximately 4.8 inches.
The secondary reflector of FIGS. 10 and 11 accept solar energy through their whole acceptance angle, and also allow the absorber pipe to emit energy in the form of infrared rays through the same acceptance angle.
In order to decrease the radiation of heat from the absorber pipe body a two-dimensional secondary reflector of the type illustrated in FIG. 12 may be used. This constitutes an improvement. This additional complexity is justified for those sections of the absorber pipe where the fluid therein is at a relatively high temperature so that an appreciable amount of infrared energy will be radiated away if the simple secondary reflector of FIG. 11 were used. The secondary reflector of FIG. 12 functions to prevent a significant fraction of the re-emitted infrared radiation from escaping the reflector. The trapped infrared radiation is returned to the absorber pipe by the shelves 304.
The overall curvature of the two sides 296 and 298 of the secondary reflector of FIG. 12 follow the parabolic curvatures 290, 288 of the secondary reflector shown in FIG. 11. The focal point of parabolic curvature 296 is point 300. The focal point of parabolic curvature 298 is point 302. The shelf-type indentations 304 in the sides 296, 298 of the two-dimensional reflector act to reduce the radiation of heat from the collector. The shelves 304 act as retroreflectors by being covered with retroreflective material such as glass beads or being indented by cube-corner embossing. Any radiation coming from the absorber pipe will have a random directionality with a lambertian distribution. The rays that strike the shelves will be reflected back to the absorber. This reduces the heat loss of the absorber, thereby increasing the overall efficiency.
A tracking solar energy collection system as described above, using line-focusing secondary reflectors of the type shown in FIG. 11 is relatively efficient within a temperature range of 200° to 400° F. A tracking system of this type could therefore be used as the line-focus tracking stage 16 in the staged system of FIG. 1.
In order to obtain higher energy concentration ratios for higher temperature results, a refocusing secondary reflector, according to the present invention, must be utilized. A preferred embodiment of a refocusing secondary reflector is illustrated in FIG. 13 as consisting of a plurality of compound curvature reflecting segments 279. Each segment has a parabolic curvature along the direction parallel to the heat-absorbing collector pipe 289 and a circular curvature along a direction perpendicular to the collector pipe 289. An insulating material 291, is placed around the pipe 289. This insulating material may be magnesia or some other suitable high-temperature insulating material. A plurality of recesses 293 having sloping sides that leave a small area 295 of the pipe exposed are formed in the insulating material and spaced to be directly underneath each compound curvature reflecting surface 297. Solar energy rays 299A reflected from the reflector surface 287 as rays 299B, strike the compound curvature reflecting surface 297 and are focused thereby into a spot on the heat-absorbing collector pipe 289. The insulating material around the pipe prevents reradiation and convection losses, except at the relatively small exposed spots at the bottom of the recesses. The concentration of the rays 299B into a spot focus on the collector pipe generates a higher temperature than would be obtainable from a line-focus, and can produce temperatures in the range of 400° to 800° F.
The use of the secondary refocusing collector, such as shown is FIG. 13, with the fixed ground-imbedded linear primary reflector of FIG. 2 can be viewed as equivalent to a dish-concentrator, since the image from any given area of the ground-imbedded reflector has diminished in size both longitudinally and transversely in forming a spot.
Alternately, if the system is considered as a trough collector system, all the collected energy enters the absorber pipe, as in any linear-focus system. However, since the absorber pipe is covered with insulation, only a small fraction, for example 1/10 of the total surface area, is available for loss by reradiation. The system then can be considered as equivalent to a linear-focus trough collector system with an absorptivity/emissivity (α/ε) ratio of 10, for example. Since this high ratio of effective α/ε is achieved geometrically and not be surface coatings on the pipe, it can be expected to remain constant with time. Appropriate thin film dichroic coating, nickel-oxides or chemical coatings such as calcium fluorides, for example, have a tendency to deteriorate with age. For this reason, it becomes difficult and costly to maintain a high absorptivity/emissivity ratio in conventional linear pipe collecting systems over a substantial period of time using such coatings. As a consequence of the consistently high α/ε ratio obtainable with the secondary refocusing reflector of this invention, this system will provide considerably higher temperatures than conventional trough systems can provide, over an extended time period. The temperatures obtainable will approach those obtainable from a tracking dish reflector.
The compound curvature reflecting surfaces 297, shown in FIG. 13, are preferably made out of a reflecting material such as aluminum which can easily be stamped out in large quantity at a very reasonable cost. Any convenient means may be utilized to movably suspend the reflecting surfaces over the heat-absorbing pipe 289. A motive means (not shown), such as a cam mechanism, is utilized to move the reflecting surface assembly 297 back and forth in the direction indicated by the arrow 301. This movement of the reflecting assembly 297 is required to maintain the spot focus of each reflector within the area of its respective recess as the sun's image changes position during the day.
FIG. 14 illustrates an alternate embodiment of a refocusing secondary reflector. The secondary reflectors 305, 307 for this embodiment consist of bell-shaped members that are suspended from the heat-absorbing collector pipe 301 at their closed end. The collector pipe 301 actually runs through the interior of the bellshaped members 305, 307 at their closed ends. The bell-shaped members have compound paraboloid curvatures therein that are chosen for the optimal refocusing of solar energy 309 entering their open mouth into a small spot area on the pipe running through their closed end. The depth of the field collectors 305, 307 decrease reradiation and convection heat loss from the exposed pipe 301. These bell-shaped field collectors 305, 307 are spaced as densely as possible along the heat-absorbing pipe 301 to provide a series of high intensity spot focuses of solar energy on the pipe 301. To prevent convection heat loss from the pipe itself, a high temperature insulating material 303 is wrapped around the pipe 301. Due to the generally inverted shape of the bell members, with the open mouth disposed downwardly, the hot spot on the pipe heats the air in the upper closed end of the bell member. As a result, hot air convection currents cannot circulate, thus avoiding another potential loss of heat energy from the pipe. The bell-shaped members thus, not only focus the incoming light rays into a spot but also diminish convection loss, and diminish reradiation loss, which effectively give a high α/ε ratio.
It may be helpful at this point to remember that the reentrant secondary reflectors already described utilized the directionality character of absorbed light (omnidirectional when reradiated) to advantage by structural means. For example, the linear-focusing secondary reflector of FIG. 12 utilized shelves that were retroreflectors to reflect reradiated energy back to the absorber pipe. The spot-image forming refocusing secondary reflector of FIG. 13, likewise can be structured to reduce the amount of reradiated energy leaving the structure. To enhance the reentrant capability of the three-dimensional secondary reflector of FIG. 14 to prevent further radiation of heat, retroreflective shelves may be used therein.
In order to enhance the effective α/ε ratio even further, an additional improvement in the system shown in FIG. 14 may be used. This improvement is shown in FIG. 15 and emphasized as items 313 and 317. Item 313 takes advantage of the difference in wavelength of incoming light and infrared radiated energy. This can be accomplished by placing a window of glass over the open mouth of a spot focus-forming secondary reflector such as shown in FIG. 15. The glass will be transparent to light coming in and opaque to the long-wave infrared energy rays radiated from the hot absorber pipe. This will decrease the outflow of energy from the hot absorber pipe, which is equivalent to an increase in the effective α/ε ratio. This is accomplished by geometrical means which is the result of a chosen structural configuration and so is not subject to degradation as are the presently used high α/ε surface coatings. The cover, 313, thus provides a greenhouse effect, freely passing incoming visible energy, but not allowing reradiated infrared radiation from the hot absorber pipe 315 to carry energy away.
Item 317 represents the use of a microscopic surface structure on the exposed spots of the absorber pipe 315. This surface structure is analogous to anechoic chamber energy trapping structure that is used in radio-frequency anechoic chambers or acoustic anechoic chambers, but of a microscopic surface feature size, consonant with the minute wavelength here involved. FIG. 15 is a cross-section of a focus-forming secondary reflector 311 that is closed at its mouth by a sheet of glass 313 or an equivalent functioning plastic, in selected cases coated with a dichroic surface. Besides returning a large portion of the infrared energy radiated from the exposed spot 317 of the collector 315, the cover 313 provides a closed environment. By purging this environment with a dry, clean gas such as nitrogen through a pipe 316, a nondeteriorating environment for dichroic and anechoic surfaces is created.
An anechoic surface of titanium, tantalum or tungsten crystal structures 321 are formed on the absorber pipe surface 317 within this protected environment, as shown in FIG. 17. The titanium crystals are formed by, for example, chemical vapor deposition techniques at a thickness of approximately one wavelength of light (0.001 mm). The pyramidal shape of these crystals 321 on the collector surface 317 detailed in FIG. 16 substantially reduces the reradiation of heat energy from the collector 317. The lambertian distribution characteristic of the heat rays leaving the absorber surface 317 is absorbed by the walls of the exposed spicules to a large extent instead of being freely radiated away. An additional advantage is that the surface 321 of FIG. 16 is an efficient absorber for visible light energy so that the factor α, the absorptivity of the surface, in the expression α/ε is high compared to conventional absorber pipe surfaces heretofor used in solar collection systems.
An additional step may be taken, when preparing the absorber pipe for use in the higher temperature stages of the collection system. This consists of placing a dichroic layer 323 (FIG. 17) of, for example, calcium fluoride, approximately 0.001 mm in thickness on the absorber pipe 317 to prevent reflections from the absorber pipe surface. This is also effective in causing the heat to be trapped in the absorber pipe.
It should be understood that any combination of the above described means to affect the α/ε ratio may be used, the particular combination chosen depending on cost effectiveness for a particular application, such as the different stages of the seriatim cooperating stages shown in FIG. 1, using different combinations of the above described improvements to make the overall efficiency for the entire system the highest value.
In order to provide a solar energy collection system that is capable of generating high temperature energy during periods when the sun's rays are not strongly evident, such as at night or on overcast days, the solar energy collection system is supplemented with a chemical energy storage system. As will be more fully explained hereinafter, the chemical energy storage system may be utilized to not only supply needed energy when the sun's energy is of insufficient strength, but may also be used to enhance the heating capacity of the solar energy system during periods when the sun's energy is being collected. This type of 24-hour system preferably will utilize the suspension, tracking mechanism and collecting mechanisms generally illustrated in FIG. 3. That is, the network of absorber pipes illustrated are rigidly interconnected and are suspended within their respective secondary reflectors that are in-turn suspended by their respective four-bar linkages. The entire network of absorber pipes moves to follow the focal surface defined by the primary reflector, hereinabove described.
The network 325 of absorber pipes is more clearly illustrated in FIG. 18. The network consists of a plurality of absorber pipe sections 50. These absorber pipe sections are the ones that actually receive the solar energy reflected from the primary ground-based reflector of FIG. 3. Each of the absorber pipes 50 is connected to an inlet manifold pipe 56 by way of rigid pipe joints 52 that are capable of withstanding high pressures and temperatures. The other ends of absorber pipes 50 are connected to an outlet manifold pipe 54 by like high pressure, high temperature rigid couplings 52.
In operation, water would be supplied to the network 325 through the inlet manifold 56, traverse the lengths of the absorber pipes 50, picking up solar energy therefrom and leave the network by outlet manifold 54. The entire network is preferably covered with high temperature insulation 327. The cool inlet manifold pipe 56 is adapted to provide room for the absorber pipes 50 to expand and contract as a result of thermal variations therein.
Each absorber pipe 50 is suspended within a secondary reflector which may be a line-image refocusing type, as illustrated in FIGS. 19 and 20, or a spot-image refocusing type, as illustrated in FIGS. 21 and 22. The function and structure of line-imaging and spot-imaging secondary reflectors has been described hereinabove in connection with FIGS. 10, 11, 12, 13, 14 and 15.
FIGS. 19 and 20 illustrate an absorber pipe 50 suspended within a line-imaging secondary reflector 329. The secondary reflector 329 directs off-angle light rays received from the primary reflector to the absorber pipe 50 thereby essentially forming a line focus on absorber pipe 50. The secondary reflector has slightly curved legs and extends the length of the absorber pipe. The interior of the absorber pipe 37 would carry a heat-absorbing fluid such as water. The absorber pipe itself is preferably a high-pressure, steel pipe. The secondary reflector 329 rotatably suspends the absorber pipe 50 by way of bearing surfaces 331 located around the pipe 50. The bearing surface may be steel ball bearings nesting in respective bearing retainer rings (like ordinary bearing retainers) 337 in the secondary reflector pipe housing or in a high temperature ball bearing track or any other convenient retaining means capable of withstanding high temperatures. The secondary reflector may be fastened to the absorber pipe 50 by way of bolts through flanges 33 thereby retaining the bottom and top part together against the absorber pipe mechanism 50 by way of the bearing surfaces. A high-temperature insulation such as steam pipe insulating material 335 preferably surrounds the entire secondary reflector housing 329 except the light ray aperture thereof. The light ray aperture is preferably covered with a transparent window 333 which may conveniently be glass or equivalent. This window as noted hereinabove not only provides a closed environment for the absorber pipe 50 but, to some extent, prevents loss of infrared radiation from the absorber pipe 50.
The spot-image-forming refocusing secondary reflector 345 may similarly be associated with an absorber pipe 50. As noted hereinabove, three-dimensional refocusing secondary reflectors are bell-shaped members that provide a plurality of spot focus points on the absorber pipe 50 rather than a continuous line focus as do two-dimensional reflectors described hereinabove.
In order to provide for temperature boosting of a solar energy collection system and to provide for energy storage that may be utilized during periods of low solar activity, the above-described solar energy collection system may be supplemented with a chemically implemented temperature transformer system. Such a temperature transformer system is described in a copending U.S. patent application filed Dec. 27, 1974, having title "Low-to-High Temperature Energy Conversion System" by Charles G. Miller and having U.S. Ser. No. 536,786. Briefly, the temperature transformer system as described in the copending patent application utilizes a complex chemical to transform a low temperature energy source into a high temperature one. This is accomplished by utilizing a reversible chemical reaction in which an endothermic reaction takes place at the low temperature level and an exothermic reaction takes place at a significantly higher temperature.
As will be more fully explained hereinafter, the three-dimensional tracking stage of a solar collector system as described herein may be utilized to provide the low temperature energy required to produce the endothermic reaction that disassociates the complex chemical into its constituent parts. FIGS. 21 and 22 illustrate the preferred structure for housing the chemical reaction.
The absorber pipe 50 containing a fluid such as water is in turn contained within a high pressure steel pipe 339. The pipe 339 is rotatably suspended by bearing surfaces 331 within the spot-image-forming secondary reflector housing 345. The entire reflector housing is covered by a high temperature insulating material 335, except for the light ray opening thereof which is covered by a transparent window 333 for the purpose, as hereinabove explained, of forming a closed environment and retaining heat within the structure. The atmosphere 349 within the three-dimensional refocusing secondary reflectors 345 may be dry nitrogen.
The hot end of the absorber pipe network, in other words, the outlet manifold 54 is covered with high temperature insulation 335 but is separated from the insulation on the absorber pipe 50 by a slip joint 347. This slip joint prevents the rotary motion of the secondary collectors about the absorber pipe from effecting the non-rotating outlet manifold section 54. The outlet manifold 54 which carries a heat-absorbing fluid is contained within another outlet manifold 346. This outlet manifold is connected to the pipe 339 containing the complex chemical by a high pressure pipe joint 343. The entire structure is contained within the three-dimensional secondary reflector structure 345.
The high temperature outlet manifold 346 is restrained by elements 341 placed between the secondary reflector housing 345 and the outlet manifold 347. This way the hot end of the absorber pipe network is restrained causing the cooler end to exhibit the expansion and contraction that will occur as a result of temperature changes in the network.
The fluid carrying absorber pipe 50 is supported within the larger high pressure pipe 339 that forms the reactant chamber for the endothermic and exothermic chemical reactions, more fully described in the above noted copending patent application, by means of a plurality of weirs 352. Assuming that the illustration of FIGS. 23 and 24 represent the endothermic reaction chamber, the constituent parts of the complex chemical such as a metal hydride would be found in the area between the external high pressure pipe 339 and the internal fluid carrying pipe 50.
A plurality of metal hydrides are available which are suitable for this application. However, it should be understood that the complex chemical utilized herein need not be limited to metal hydrides since there are other complex chemicals available such as ammonia which exhibit a reversible endothermic, exothermic reaction cycle. For purposes of convenience, however, the discussion will proceed under the assumption that metal hydrides are being utilized. A Magnesium Hydride (MgH 2 ) is preferred because it disassociates at a pressure of approximately 200 psi and a temperature of 752° F. Other metal hydrides that are also satisfactory can be found in a text titled "The Solid-State Chemistry of Binary Metal Hydrides" by G. G. Libowitz published by W. A. Benjamin Company, 1965. Assuming Magnesium Hydrides were being used in the illustration of FIGS. 23 and 24 and the reaction chamber therein was for the endothermic reaction in which the Magnesium Hydride is disassociated into its constituent elements of Magnesium and Hydrogen, the atmosphere 361 around the pipe 50 would be Hydrogen. The top layer 357 at the bottom of the pipe 339 would be the as yet not disassociated Magnesium Hydride and the bottom layer at the bottom of the pipe 359 would be disassociated Magnesium. The Hydrogen gas 361 can be easily removed by conventional pumping techniques leaving the solids Magnesium and Magnesium Hydride behind.
In order to take advantage of the exothermic qualities of the process during periods of low solar activity whereby the exothermic reaction becomes the primary heat source, rather than the solar energy, the entire secondary reflector mechanism would be racked so that the transparent window of the secondary reflector is well insulated. As can be seen from FIG. 25, the secondary reflector mechanism 48 attached to the four-bar linkage 46 rotates about its axis which is perpendicular to the plane of the paper, as the bar linkage 46 tracks the sun's movement, in a manner hereinabove described in connection with FIG. 9. In a period of low solar activity four-bar linkage 46 is moved so that the secondary reflector is located at position 48'". In this position the transparent window of the secondary reflector 48 may be covered by an insulated mirrored surface 365 that can be conveniently slid into place from a storage position 365'. It should be remembered that the position of the secondary reflector 48'" is assumed only when the solar activity is too low to provide thermal energy to the absorber pipe contained within the secondary reflector, thereby requiring an alternate heat source.
An exemplary illustration of a staged seriatim solar energy collection system utilizing a closed loop endothermic, exothermic chemical reaction process for the purpose of supplying an alternate thermal source or boosting the thermal output of the solar collection system is illustrated in FIG. 26. Water at local ambient temperature is supplied to the system over input line 365 to a solar pond 367, of the type described in the copending U.S. Patent Application noted hereinabove. The output of the solar pond 367 in the form of water having increased thermal energy therein is supplied to a linear-image forming tracking solar energy collection stage 377 through a valve 371 and lines 373. The two-dimensional tracking stage 377 may take the form described hereinabove. The output of this two-dimensional tracking stage in line 379, containing even more thermal energy, is supplied by way of valves and piping to a first spot-image-forming tracking stage 381 of the type illustrated and described herein. The output of this three-dimensional tracking stage on line 383 is supplied to a second three-dimensional tracking stage 391 which may be of similar, if not identical, construction as to the first three-dimensional tracking stage 381 of the system. The output of this, the second three-dimensional tracking stage 391 on line 393 would normally have a temperature at approximately 1000° F. This may be supplied to utilizing equipment by way of the valve 437 and output line 445.
In order to provide the function of thermal boost or alternate thermal source, the first three-dimensional tracking stage 381 and second three-dimensional tracking stage 391 of the solar energy collection system is constructed according to the principles illustrated in FIGS. 3, 14, 15, 16, 17, 18, 21, 22, 23, 24 and 25. In addition a compressor 387, a turbine 401 and a gas storage facility is utilized. The gas constituent of the disassociated complex chemical found in the reaction chamber of the first three-dimensional tracking system 381 and of the second three-dimensional tracking system 391 are removed therefrom at high pressure which is reduced by turbine 401 before being supplied to a gas storage facility 407 for later retrieval. The gas removed from the storage facility 407 is retrieved when additional thermal energy is required. At such time the gas is supplied to either the first three-dimensional tracking stage 381 or the second three-dimensional tracking stage 391 whereupon an exothermic reaction is created generating considerable thermal energy.
Assume now that the system of FIG. 26 is operating in the thermal boost or superheating mode and that the initial condition of the chemical constituents 417 in the first three-dimensional tracking stage 381 is Magnesium Hydride (MgH 2 ) and that the chemical constituent 421 in the second three-dimensional tracking stage is Magnesium. Heated water from the solar pond 367 would be supplied by way of line 369, valve 371 and line 373 to the two-dimensional tracking stage 377. This tracking stage would heat up the water to its peak efficiency temperature and then supply it over line 379 valve 431, line 441 and valve 433 to the first three-dimensional tracking stage 381. While this higher temperature water is being supplied to the first three-dimensional tracking stage 381, thermal energy is being absorbed by the absorber pipe and chemical reaction chamber within this tracking stage at a temperature sufficient to cause disassociation of the Magnesium and Hydrogen, thereby creating a Hydrogen atmosphere 415 and a Magnesium Hydride and Magnesium particulate 417 within the reaction chamber. As the Hydrogen is created by the endothermic reaction, resulting from the elevated temperature, a portion of the Hydrogen is drawn off by way of line 397 and valve 399 to drive turbine 401 which may be used to supply power to compressor 387. The Hydrogen not drawn off from the reaction chamber and the first three-dimensional tracking stage 381 is supplied by way of line 385 to a compressor 387 that compresses the Hydrogen considerably and supplies it over line 389 to the chemical reaction chamber of the second three-dimensional tracking stage 391.
During the time that this is occurring, the water flowing through the first three-dimensional tracking stage 381 is also heated by the solar energy being absorbed and is supplied by way of valve 435 and line 383 to the second three-dimensional tracking stage 391. As it travels through the absorber pipes and the second three-dimensional tracking stage 391, the compressed hydrogen being supplied to the reaction chamber around the absorber pipes causes the Magnesium metal 421 and the compressed Hydrogen atmosphere 419 in the reaction chamber to recombine in an exothermic reaction causing thermal energy to be released which in turn superheats the water flowing within the absorber pipes. This heat superheats the water leaving the second three-dimensional tracking stage 391 on line 393 through valve 437 to output line 445.
It should be observed that the chemical reaction chamber within the three-dimensional tracking stages 381 and 391 are limited in their capacity to hold the reactant materials. For the example of Magnesium Hydride, 2.8 pounds of Magnesium Hydride disassociated is equivalent to the storage of 1 kilowatt hour of thermal energy. Upon the Magnesium Hydride 417 in the first tracking stage 381 being completely disassociated into its constituent part of Magnesium and Hydrogen, only Magnesium will be left in the reaction chamber. The contents of the chemical reaction chamber in the second three-dimensional tracking stage 391, as a result of the exothermic recombining reaction will be the complex chemical Magnesium Hydride. At this point, the valves of the system are actuated to cause water flowing in line 379 to be first directed to the second three-dimensional tracking stage 391 and then to the first three-dimensional tracking stage 381.
Thus, for example, the output flow of stage 377 is routed over line 379 through valve 431 which routes the fluid over lines 439 to valve 437, to line 393 and the second three-dimensional tracking tracking stage 391. As a consequence of solar energy being absorbed by this second three-dimensional tracking stage the Magnesium Hydride therein creating an endothermic reaction that generates Hydrogen and Magnesium. The Hydrogen is drawn off by way of line 425 and valve 423, and supplied to turbine 401. The gas output of the turbine 409 is supplied to the gas storage device 407 by way of line 403 and valve 405. The Hydrogen gas not removed by way of line 425 is supplied over line 389 to compressor 387 that in turn supplies such gas over line 385 at an elevated pressure to the chemical reaction chamber in the first three-dimensional tracking stage 381. In turn, the water from the second three-dimensional tracking stage 391 is supplied over line 383 and valve 435 to the first three-dimensional tracking stage, where, besides absorbing the thermal energy from the solar heat, it absorbs thermal energy from the exothermic reaction occurring thereat. The resultant superheat steam leaves the first three-dimensional tracking stage 381 by way of valve 433 and output line 443 to a desired utilization device.
It can thus be seen that the chemical reaction in which a complex chemical is disassociated and recombined in a closed loop endothermic/exothermic manner as more clearly explained in the copending patent application by Charles G. Miller, having U.S. Ser. No. 536,786, U.S. Pat. No. 4,044,821 creates a considerable temperature boost to a solar energy collection system. The gas constituents stored in gas storage device 407 which may be of the type used for storing natural gas can be removed over lines 409 by way of valve 411 line 413, valve 426 and lines 429 and 427 to enhance the thermal boost or superheat process.
Assume now for purposes of example that conditions of very low solar activity exist, as would occur during night time. In order to provide thermal energy during such periods, the system would be reconfigured so that the output of the solar pond 367 on line 369 would be routed by way of valve 371 to line 375, the solar pond 367 constructed according to the description in the above noted copending application acts as a thermal storage device and the output of the water on lines 369 therefrom are fairly constant over a long period. The water in line 375 may be supplied either to the first three-dimensional tracking stage 381 or the second three-dimensional tracking stage 391 of the solar collector system by way of valve 435 depending on which stage was being utilized for exothermic recombination reaction. Assuming that the first three-dimensional tracking stage 381 was being utilized because the chemical constituent 417 in the reaction chamber was Magnesium, the Hydrogen gas from the gas storage device 407 would be supplied over lines 429 to the second three-dimensional tracking stage 391 for the purpose of delivering it to compressor 387 over line 389 which would considerably increase the pressure at which the gas is delivered to the reaction chamber over line 385 of the first three-dimensional tracking stage 381. As the water is being delivered to this section 381, the exothermic reaction created as a result of the introduction of high pressure Hydrogen into the reaction chamber would cause recombination of the Magnesium and Hydrogen to form Magnesium Hydride delivering substantial thermal energy to the fluid leaving the stage 381 on line 443. A similar situation would exist for the second three-dimensional tracking stage 391 except that the gas from the storage facility 407 would be delivered by way of valve 426 over lines 427 to the first tracking stage 381 to be compressed by compressor 387 and thereafter supplied to the second tracking stage 391 over line 389. It is conceived that the gas stored in storage facility 407 and the Magnesium contained in one of the reaction chambers would be sufficient to generate high temperature energy for an extended period of time.
In summary what has been described is a large-scale solar power system that is sufficiently efficient, cost effective to be competitively attractive compared to alternative large scale, prime power sources to be used for example to supply large scale utility power generating equipment in the same sense that coal or nuclear generated steam supplies utility power generating equipment.
The solar power system is preferably made up of several stages, each stage operating within its optimum temperature range. As can be seen in FIG. 1 the early stages may be of the higher efficiency, lower working temperature type. For several stages a fixed linear ground-based linear primary reflector is constructed by relatively inexpensive processes utilizing available road-building machinery. The basic tracking system is optimized for particular temperature ranges by use of various secondary reflectors that help to concentrate the light energy on the collector or heat absorber and also substantially reduce the reradiation of infrared energy from the collector. The solar energy collection system is also adapted to provide superheat steam over limited and extended periods of time by utilizing the exothermic reactive properties of such complex chemicals as metal hydrides.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood, therefore, that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
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A fixed, linear, ground-based primary reflector having an extended curved-sawtooth contoured surface covered with a metallized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus of the reflector primary. The primary reflector may be constructed by a process utilizing well-known freeway paving machinery. The solar energy absorber is preferably a fluid-transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. To obtain higher temperature levels, refocusing secondary reflectors, that cause a series of discrete spots of highly concentrated solar energy to fall on the fluid-transporting pipe, are utilized. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.
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STATEMENT OF GOVERNMENT INTEREST
This invention was made with Government support under contract no. DE-AC04-94AL85000 awarded by the U.S. Department of Energy to Sandia Corporation. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a bulk composition suitable for counting individual neutrons. More particularly, the present invention is drawn to a specific material which is sensitive to neutron radiation and which can comprise a semiconducting substrate to act as a 3-dimensional detector array.
2. Description of the Prior Art
Conventional neutron detectors typically include devices that operate as ionization chambers or proportional counters, both of which use a neutron active gas such as BF 3 or He. Upon absorption of neutrons, such gases release energetic reaction particles. These particles produce ionization in the surrounding gas which are detected by appropriately biased electrodes. Other detectors coat the walls of the ionization chamber with a solid neutron active material such as 6 Li, 10 B, or 235 U. These materials also absorb neutrons and release particles that produce ionization.
One class of solid state neutron detectors detect electron-hole pairs that cross a semiconductor junction. The electron-hole pairs are produced by reaction particles formed as result of neutron absorption within films or dopants of neutron active material incorporated within the detector. One such solid state neutron detector is disclosed in U.S. Pat. No. 3,227,876 to Ross, which includes a silicon semiconductor having a layer doped with boron. Neutrons are absorbed by the boron layer, thereby creating energetic reaction particles that, in turn, create electron-hole pairs that diffuse into and across the junction to produce a current pulse. The detector may be encapsulated by a layer of hydrogenous moderator material a few centimeters thick in order to reduce the speed of incoming neutrons. Such detectors are susceptible to radiation damage and are not capable of operating at temperatures above 30° or 40° C. for extended periods of time, making them unsuitable for use in high temperature, high radiation environments.
U.S. Pat. No. 3,805,078 to Kozlov discloses a solid state neutron detector including at least one layer of diamond crystal.
U.S. Pat. No. 4,419,578 to Kress discloses another solid state neutron detector that uses a hydrogen containing semiconductor material.
A major problem with prior art neutron detectors is the sensitivity of the detector to non-neutronic components of the radiation field, particularly gamma ray sensitivity. Lithium glass scintillators, although generally less efficient, are an effective means for detecting low-energy neutrons and find wide application in neutron scattering research. However, lithium glass scintillators also suffer from a sensitivity to gamma-rays where the presence of a background radiation is large in relationship to a flux of neutrons. In such instances, the gamma sensitivity of Li-glass simulates a neutron capture event in Li-glass and since there is no effective technique for separating the gamma signal from the neutron signal (for coincidental multiple photon events with total energy deposition in the vicinity of the capture peak) the quality of the data obtained is seriously degraded.
Neutron scattering research facilities require a detector system that is efficient, fast, and gamma insensitive. None of the detector systems currently used by researchers meet all these requirements.
SUMMARY OF INVENTION
In accordance with the principles of the invention, a new neutron detector has been developed which overcomes the disadvantages of the prior art scintillation or gas-phase detectors. The neutron detector in accordance with the invention relies upon single or polycrystalline, boron-containing compounds, useful for neutron detection. The 10 B(n, alpha) reaction possesses a large cross section for neutron capture and produces nuclear decay fragments which are at once heavy and energetic. The present invention takes advantage of the relatively short distances over which the energy of these heavy ion decay products is dissipated within crystals of the boron-containing compound to permit using moderately thin though still structurally robust wafers for detecting the presence of neutrons. Also possible are articles prepared from powders of the boron compound prepared by the instant process: thin sintered wafers prepared by comminuting the boron compound of the present invention to a powder, mixing the powder with binder agents and sintering it, or thin layers of pastes prepared by mixing a comminuted powder of the boron compound with wetting and/or dispersing agents and laid down by a printing process.
Because of the reduced need for large volume crystals the detector is rendered inherently less sensitive to background gamma-ray radiation due to the comparatively large mean-free-path lengths for these energetic photons to dissipate their energy. Thin or very small crystals result in most of this radiation passing undetected through these crystals and thereby strongly discriminating against gamma background events.
The borate materials described in the instant invention provide a high boron atomic density, and is conveniently formed into single or polycrystalline boules. The specific variation of these materials which is useful for providing the desired neutron detection response is prepared by INRAD Corp. in a process which avoids the use of a flux, typically sodium oxide or a fluoride, in the growth of the crystal boules. Crystalline material fabricated by standard industry processes using sodium oxide or fluoride fluxes have been found to provide virtually no response to impressed neutron radiation. It is believed, therefore, that the observed behavior of crystal boules fabricated by the fluxless process is the result of substantially reduced impurity levels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Illustrates the response of various borates composition to radiation produced by 3 MeV protons on lithium gallate.
FIG. 2 . Illustrates the response of α BBO to radiation produced by 3 MeV protons on lithium gallate. Amplifier shaping time is 10 μs.
FIG. 3 . Illustrates a block diagram schematic of the detector sensor of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Disclosed herein are inorganic crystalline salts that have been found to exhibit semiconductor properties in the presence of ionizing radiation such as neutron radiation. These materials have been found to provide a measurable electrical response proportional to the amount of radiation striking crystals of the material and therefore can act as suitable neutron radiation detectors.
In general, materials of this type would not be expected to exhibit substantial electronic conduction. They are not considered to be semiconductors but are rather inorganic oxide salts with a high ionic component. Unlike an ionic crystal, an intrinsic semiconductor exhibits covalent bonding wherein electrons are “shared” between adjacent bonded atoms. Furthermore, semiconductors are characterized by a band gap between the material's valence and conduction bands that is typically no more than a few electron-volts (eV).
Because this gap is so low, electrons can easily pass from the valance band into the conduction band when excited. A consequence of this “promotion” of valence electrons is to free these excited electrons to “drift” under the influence of an externally applied electric field and to act as charge carriers to conduct current. Additionally, for each electron that is promoted out of the valance band, a positively charged “hole” is created in the covalent bond by the departing electron. Charge neutrality is, therefore, maintained by the creation of these electron-hole pairs. Because of the ease with which electrons can migrate in these materials, electrons in adjacent bonds can “jump” to fill a “hole” and thereby create a second hole at one unit cell removed from the first. Holes, therefore, can “drift” through the lattice of the semiconductor much like excited electrons such that both electrons and holes can conduct current.
However, electron-hole pairs can be created in semiconductors by a number of other mechanisms including the interaction of various forms of energetic radiation, such as alpha or beta particles, and electromagnetic radiation, such as gamma or x-rays. Because the material of the present invention comprises crystals containing boron, and in one case lithium, which are both known to exhibit high neutron cross sections and since both produce alpha particles and other ions as the result of the neutron capture process, materials containing boron or boron and lithium might be considered as suitable candidates for investigation as neutron detectors regardless of their status as non-semiconducting materials.
The materials of the present invention comprise crystals grown from melts of borate compounds. Specifically, crystals of either alpha or beta phase barium borates or of lithium tetraborate have been investigated. Given their high intrinsic resistivities, the high boron density per unit cell, the high nuclear cross-section of boron, and the nature of the decay products resulting from neutron capture by boron, one would tend to expect that these materials might act as effective detectors for neutron radiation.
This has not been found to be the case in crystals grown by conventional means. The well-known Czochralski process is widely used to cheaply produce single crystal boules. Generally speaking, however, a flux, such as sodium oxide or sodium fluoride, is used to help lower the melting temperature of the host material and to help control the incipient crystal phase which is precipitated from the melt as it freezes around a “seed” crystal. When borate crystals are prepared by this conventional process which incorporates a flux, little or no discernable signal is observed when these crystals are subjected to a pulsed stream of neutron radiation.
Materials were ranked quantitatively using a proton beam method. and two new candidate materials, lithium tetraborate (Li 2 B 4 O 7 ) and α barium borate (αBBO) were found to have markedly better charge collection than β BBO. Neutrons produced in the proton beam by the 7 Li(p,n) 7 Be reaction were observed. The gamma flux was reduced by choice of target materials. Radiation produced in this way was used to test the candidate materials. Pulse response was observed, corroborating the material property measurements.
Quantitative Material Property Testing
The quantitative evaluation and ranking of candidate materials was performed using the above mentioned proton beam stimulus. Thin carbon paint electrodes were used to contact the specimens, which ranged in thickness from 300 microns to 1 mm. Both pulse and current mode sensing were demonstrated. Lithium tetraborate (Li 2 B 4 O 7 ) and a barium borate (αBBO), are similar to lithium triborate (LiB 3 O 5 or LBO) and β BBO, but exhibit markedly better electron transport properties. Estimates of mobility-lifetime products of generated carriers were made for these materials, however significant de-trapping of carriers complicated the analysis.
Typical results for are shown in FIG. 1 . The results were normalized by adjusting the relative signal strengths to correct for specimen thickness and beam current variations. Analysis of these and additional data indicate an effective electron μτ product of approximately 10 −6 cm 2 /volt for the α phase of BBO. Since the resistivity of this material is high (>10 11 Ωcm), this is well above the threshold theoretically required for detection of single thermal neutrons in a practical device.
Pulse transient analyses on the borate crystals show that shallow traps dominate the response, resulting in a “persistent current” or afterglow-like effect, lasting 10-100 μs after the stimulus is removed. Since the shaping time for the pulse amplifier is 1-10 μs, only a small fraction of the charge is collected during the measurement in these crystals. therefore, nonlinear response to large (μ-Joule) proton pulses, as seen in FIG. 1, results in underestimates for electron transport properties.
Neutron Response Testing
To test for neutron response in the borate crystals a pulsed beam of neutrons was produced by placing various materials in a proton ion beam. LiF was proposed first as the target material. Fluorine reactions, however, produced a large quantity of high-energy gamma rays, which swamp the modest neutron signal as measured with a CdZnTe detector. When lithium gallate was used as 30 the target, however, this background was largely eliminated. Neutrons were detected outside the vacuum chamber (about ½ meter from the source) at the rate of 6 mR/hr with a beam current of 8 nA. The gamma rate measured with a pancake probe at this location was about 0.08 mR/hr. All of the crystals were tested under these conditions. Results for an α BBO crystal are shown in FIG. 2 as a typical of these crystals. The Compton edge can be seen below channel 300 , and a strong response peak is seen centered at about channel number 525 . The count rate was about 10 cps on average, and was dependent on both shaping time and detector bias.
As indicated above, the measured response of Li 2 B 4 O 7 and α and β BBO crystals to the pulsed neutron beam is summarized in FIG. 1 . Not shown are results for lithium and barium borate crystals that were grown in the conventional manner with a sodium oxide or sodium fluorine flux. In these cases, virtually no signal response could be detected.
PREFERRED EMBODIMENT
Detectors & Detector Array
Applicants herein disclose a new use for known borate compositions: specifically, crystals of lithium tetraborate or alpha-barium borate, which have been grown from the melt without the use of a flux, are observed to provide a discernable signal response in the presence of a pulsed beam of thermal neutron radiation. As noted above the current technology for detecting thermal neutrons relies upon bulky and expensive helium gas filled tubes. The present invention, however, discloses the use of a solid, crystalline material composed of a high concentration of elements having a substantial neutron capture cross-section. A detector based on the crystals of the present invention, therefore, will offer many advantages over the current state-of-the-art. In particular, a detector array based on lithium borate or barium borate crystals could be fabricated into nearly any shape or size. Applicants contemplate individual detectors or a detector array comprising a number of small, individual wafers of lithium tetraborate or alpha-phase barium borate and supporting electronics, as shown in FIG. 3 . These wafers may be either single or polycrystalline or they may be sintered composites containing a dispersion of very small crystalline grains.
Finally, a detector array comprising a plurality of these detectors, arranged in planar, cylindrical, or spherical geometries, in order to provide the detection coverage desired is also contemplated. This capability leads to the result that high resolution 3D imaging is possible since the geometries can be layered in an overlapping net-like fashion.
Applicants therefore, disclose a neutron detector 10 comprising a wafer 11 of crystalline or polycrystalline lithium tetraborate or alpha-phase barium borate, as shown in FIG. 3 . Each wafer 11 is prepared with electrodes 12 that are plated or deposited onto opposing surface of the wafer 11 . Each electrode 12 is attached to an electrical lead 13 connecting the electrode to a source of high voltage 14 . The analyzer circuit is completed by attaching a preamplifier 15 followed by a pulse shaping amplifier 16 to one the electrodes on each crystal.
As wafer 11 is exposed to a neutron flux 17 , some of the neutrons are captured by the boron contained within the lattice of the crystals comprising wafer 11 to create 7 Li and an energetic alpha particle (˜2.8 MeV) as shown below.
10B+ n→ 4 α+ 7 Li
To a lesser extent, lithium in the lithium tetraborate crystals will also contribute to the capture reaction by,
6Li+ n→ 4 α+ 3 H
but, the nuclear cross section of lithium is only about 25% that of boron, (941 barns vs. 3838 barns) and the atomic concentration of lithium in the tetraborate crystal. is only half that of boron.
The energy carried by the alpha particles is now deposited into the crystal lattice ionizing one or more of the surrounding atoms and thereby creating a number of mobile electron-hole pairs 18 . These positive and negative charge carriers are free to drift toward the electrode of opposite charge, under the influence of the applied high voltage field, where a small step-change in voltage is recorded with each event. This signal is amplified and then passed to operational amplifier 16 where the signal is integrated to form a shaped pulse whose height is proportional to its relative energy.
Output pulses from the shaping amplifier 16 are directed to a digitizer (ADC) 19 , and multi-channel analyzer (MCA) 20 which digitizes the pulse height of each of the signal pulses received from the shaping amplifier and then accumulates each of those digital signals in channel numbers corresponding to the magnitude of the digitized signal. The signal spectrum output of MCA 20 consists of one or more broad peaks, corresponding to the energies of the neutron capture reaction, or reactions, presented on oscilloscope display 21 , or some similar display medium. As seen in FIG. 2, and as noted earlier, a single broad peak is observed at about channel number 525 under the experimental conditions used.
While the most obvious embodiment of the present invention is drawn to a single crystal, it is not necessarily the most desirable approach. As noted above wafer 11 is also possible as a sinter composite formed to any desired shape. The crystalline boule may be comminuted into a powder, mixed with any of a number of binders to aid in sintering, pressed into a ‘green’ shape and then sintered at a temperature of about 0.75-0.9 of the material melting temperature. The article might also be prepared by known hot-pressing techniques with or with out binders.
In addition, wafer 11 also could comprise a screen printed layer of a paste formed by mixing a comminuted powder of the crystalline boule with any of a number of wetting and/or dispersing (suspension)agents. The printed layer would be placed onto a electrically conductive substrate acting as a charge collecting electrode. After drying the printed layer a second electrode would be placed onto the top surface of the layer.
These approaches are operable because each of the grains comprising the powder used to produce the paste or the sintered composite are themselves one or more crystals of the original crystalline boule. The powder is, in turn, prepared so that a plurality of the grains remain in electrical contact with each other and with electrodes 12 .
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Crystals of lithium tetraborate or alpha-barium borate had been found to be neutron detecting materials. The crystals are prepared using known crystal growing techniques, wherein the process does not include the common practice of using a fluxing agent, such as sodium oxide or sodium fluoride, to reduce the melting temperature of the crystalline compound. Crystals prepared by this method can be sliced into thin single or polycrystalline wafers, or ground to a powder and prepared as a sintered compact or a print paste, and then configured with appropriate electronic hardware, in order to function as neutron detectors.
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FIELD OF THE INVENTION
[0001] The present invention relates to a system and method for acquiring ultrasound images. The invention also relates to a computer program for implementing said method.
BACKGROUND OF THE INVENTION
[0002] Ultrasound imaging is commonly used to diagnose many different diseases and the progression of these diseases. In order to best adapt the image acquisition to the specific disease, the organ under investigation, and different characteristics of the patient, there are numerous acquisition parameters that need to be set appropriately. These parameters are related to the transmission and reception of the ultrasound signals, the processing of the measured signals, image reconstruction, image display and image storage. They include such operating parameters as the depth of an image, the location of the transmit focus, the number of focal zones, whether to use the B mode or color Doppler mode, whether harmonic or fundamental frequencies are to be used for imaging, image resolution, frame rate etc. In the clinical context of monitoring patient response to cancer treatment, the same ultrasound scanner is used for multiple patients and the settings are often changed. Manually changing the parameters for every acquisition is time consuming and error-prone. Therefore, many systems include tissue-specific presets (TSP). These are sets of imaging parameter values that have been optimized for a particular application, for example imaging of the liver or imaging of the carotid artery. With any given ultrasound transducer, the manufacturer typically offers a selection of tissue-specific presets that the user may choose from to quickly set up the ultrasound scanner for a particular scanning task. Often, these general presets need to be changed and adapted to specific patients.
[0003] U.S. Pat. No. 5,315,999 discloses an ultrasound imaging system in which sets of imaging parameter values are saved as preset modes. When a user later selects one of the preset modes, the system automatically operates in accordance with the corresponding set of imaging parameter values. The system can store preset modes for different exam types, for different image displays, for different patients and for different users.
[0004] The inventors realized that it is crucial to guarantee that for each patient the same imaging parameter values are used throughout the patient follow-up to ensure reproducibility of scans and allow for scans at different points in time to be compared with one another to assess patient response to treatment.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide an ultrasound imaging system that ensures that in subsequent examinations of the same patient ultrasound images are acquired under conditions such that the images can be compared and can be used to monitor disease progression.
[0006] It is a further object of the present invention to improve the workflow for ultrasound imaging in monitoring disease progression.
[0007] In a first aspect of the present invention a an ultrasound imaging system is presented that comprises
[0008] an image acquisition unit configured to acquire an ultrasound image based on a set of acquisition parameters,
[0009] a user input for entering a patient identifier,
[0010] a database access configured to access a database of sets of acquisition parameters, wherein the sets of acquisition parameters are associated with patient identifiers, and
[0011] a control unit configured to automatically retrieve a set of acquisition parameters that is associated with said patient identifier based on an entered patient identifier and control the image acquisition unit to acquire an ultrasound image based on the retrieved set of acquisition parameters.
[0012] Based on the entered patient identifier (which can be a number that uniquely identifies a patient, as it is commonly used in hospitals), the ultrasound imaging system looks up the set of acquisition parameters that are stored in the database associated with this patient identifier. The stored acquisition parameters can be either the parameters that were used for this patient at the last examination or they can be acquisition parameters that were stored specifically as “preferred” parameters that should be used for examinations of this patient.
[0013] In an embodiment according to the invention, the ultrasound imaging system further comprises a selection user interface, wherein the control unit controls the image acquisition unit to acquire an ultrasound image if the selection user interface is operated by a user.
[0014] In a preferred embodiment according to the invention, the sets of acquisition parameters are further associated with body organs, the control unit is adapted to determine the body organs for which sets of acquisition parameters are available for a given patient identifier, and the selection user interface is adapted for allowing a user to choose from among the determined body organs. If for a given patient several organs have been examined with the ultrasound imaging system, this ensures that the acquisition parameters are also adapted to the specific organ of the patient.
[0015] In another preferred embodiment of the present invention, the acquisition unit comprises an exchangeable transducer unit and the sets of acquisition parameters comprise one parameter for identifying a transducer unit. Storing information about the used transducer together with other acquisition parameters allows the ultrasound imaging system to ensure that the same transducer is used for follow-up studies of a patient.
[0016] In another embodiment of the present invention, the ultrasound imaging system further comprises an automatic selection unit configured to automatically detect a near organ that the image acquisition unit is near to. For example, the image acquisition could acquire a test image as soon as it is placed on the patient's body. Based on this test image, the automatic selection unit could determine which organ the acquired test image corresponds to. This could be done for example by comparing the test image with images that have previously been acquired from the same patient or it could be compared with a database of ultrasound images that are characteristic for certain organs.
[0017] Automatically detecting the organ from which the user is about to acquire a diagnostic image has the advantage that the workflow can be simplified even further. For example, if for a given patient sets of acquisition parameters are available for liver, heart and gall bladder, and the automatic selection unit detects that the user has placed the image acquisition unit near the liver, the control unit could automatically retrieve the set of acquisition parameters associated with the liver. Subsequently, it could control the image acquisition unit to acquire an ultrasound image based on the retrieved set of acquisition parameters associated with the liver.
[0018] In a further aspect of the present invention a method is presented that comprises
[0019] entering a patient identifier,
[0020] automatically retrieving from a database a set of acquisition parameters that is associated with said patient identifier, and
[0021] controlling an image acquisition unit to acquire an ultrasound image based on the retrieved set of acquisition parameters.
[0022] According to further aspects of the present invention a computer program for implementing said method is provided, said computer program comprising program code means for causing a computer, when said computer program is carried out on the computer, to carry out the steps of:
[0023] displaying a user input field for entering a patient identifier,
[0024] automatically retrieving from a database a set of acquisition parameters that is associated with said patient identifier, and
[0025] controlling an image acquisition unit to acquire an ultrasound image based on the retrieved set of acquisition parameters.
[0026] Preferred embodiments of the invention are defined in the dependent claims. It shall be understood that the claimed method and the claimed computer program have similar and/or identical preferred embodiments as the claimed device and as defined in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings
[0028] FIG. 1 shows a block diagram of an embodiment of an ultrasound imaging system according to the present invention,
[0029] FIG. 2 shows a flow chart of a method according to the present invention, and
[0030] FIGS. 3 to 5 show preferred embodiments of a user interface for an ultrasound imaging system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] FIG. 1 shows a schematic block diagram of an ultrasound imaging system 10 according to the present invention. The image acquisition unit 12 comprises an exchangeable transducer unit 14 and a transducer sensor unit 15 which is capable of recognizing different exchangeable transducer units 14 .
[0032] The control unit 16 is connected to a number of user interface components: the user input 18 , the selection user interface 20 , the parameter user interface 22 , and the notification unit 24 . Based on the patient identifier 26 that is entered in the user input 18 , the control unit 16 is adapted to retrieve a set of acquisition parameters that corresponds to this patient. In this embodiment, the user input 18 directly takes a patient identifier as input, e.g. a number that is unique for this patient. In other embodiments, the user input 18 could also comprise input fields for patient name, gender, and birth date, such that the user input 18 can look up the corresponding unique patient. Once a patient has been uniquely identified, the control unit 16 uses a database access 28 to retrieve corresponding acquisition parameter settings. The database access 28 could be a database that is part of the ultrasound imaging system 10 . More commonly, it is a connector to a network which includes a dedicated database server. For example, in a hospital, there is a typically a network-attached server that stores images and image acquisition settings such that they can be accessed from imaging devices in different locations.
[0033] The selection user interface 20 allows the user to choose between different organs for which acquisition parameters for this patient are available. For example, the patient could have been examined previously at the heart, the liver, and the prostate; this would be shown as options to the user. If there is only one set of acquisition parameters in the database that is associated with the patient identifier 26 of the current patient, in one embodiment of the invention (not shown), the selection user interface 20 is automatically reduced to only show a button, which allows the user to immediately start image acquisition with this set of acquisition parameters. In one embodiment of the present invention, the acquisition parameters that are retrieved by the control unit 16 from the database access 28 are shown to the user and the user is given the opportunity to change some of the parameters. Even if, in this case, the acquisition parameters are not exactly identical to the acquisition parameters that were previously used for this patient, the user is made aware of the fact that he deviates from previously used settings Likely, he would only do so if there is good reason, e.g. if it has turned out that previously used settings are disadvantageous in important aspects. The parameter user interface 22 could highlight those parameters which are different from the previously used parameters.
[0034] As described before, the control unit 16 is aware of which exchangeable transducer unit 14 is connected to the image acquisition unit 12 . If sets of acquisition parameters are available for a given organ of a given patient, but the exchangeable transducer unit 14 does not correspond to the transducer unit that is identified in the set of acquisition parameters, the notification unit 24 is adapted for notifying the user. The notification unit 24 could be a small warning sign, e.g. an exclamation mark 24 that is displayed next to the description of the set of acquisition parameters for which the exchangeable transducer unit 14 does not match the parameters. In other scenarios, the notification sign could be more interfering, e.g. a larger blinking sign or a sound signal.
[0035] In one embodiment, the control unit 16 would be configured not to start acquiring ultrasound images in this situation. In another embodiment, the user would be given the option to proceed with the image acquisition. If necessary, the control unit 16 could change some of the acquisition parameters such that they are compatible with the exchangeable transducer unit 14 that is used instead of the preferred transducer unit that is identified in the acquisition parameters.
[0036] FIG. 2 shows a flowchart of one embodiment of a method according to the present invention.
[0037] In step S 10 , the user enters a patient identifier 26 .
[0038] In step S 12 , the corresponding sets of acquisition parameters are retrieved from the database.
[0039] In step S 14 , further processing depends on the number of sets that have been found:
[0040] If no set of acquisition parameters have been found for this patient identifier 26 , the parameter user interface 22 is displayed in step S 16 .
[0041] In step S 18 , the user enters a complete set of acquisition parameters (or, in an alternative embodiment, he loads a standard set of acquisition parameters).
[0042] In step S 20 , which occurs after a complete set of acquisition parameters has been entered or retrieved from a standard set, a Start button 34 and a Save button 38 are displayed. In another embodiment, there is a “Save and Start” button, i.e., both steps are initiated with the same user command. In yet another embodiment, there is only a Start and Save button, i.e., the user can only start the image acquisition and store the image acquisition parameters at the same time. This ensures that all acquisition parameters that are used once for an image acquisition can one be reproduced in order to obtain comparable images at a later examination.
[0043] In step S 22 , the ultrasound images are acquired.
[0044] If in step S 14 it is determined that only one set of acquisition parameters has been found, the method proceeds to step S 24 and immediately shows a Start button which allows the user to start acquiring ultrasound images with the found set of acquisition parameters. Alternatively, of course, there are also user interface elements which allow the user to change the found set of acquisition parameters or to enter a new set of acquisition parameters. For simplicity reasons, the corresponding steps are not shown in FIG. 2 . In one embodiment of the invention, there is always a check whether the exchangeable transducer unit 14 that is attached to the image acquisition unit 12 matches the transducer unit that is identified in the set of acquisition parameters. This is also not shown in FIG. 2 .
[0045] If in step S 24 it is determined that more than one set of acquisition parameters corresponds to the entered patient identifier 26 , the method proceeds to step S 26 and shows the selection user interface 20 .
[0046] In step S 28 , the user chooses one of the organs for which corresponding sets of acquisition parameters for this patient were found.
[0047] Subsequently, the ultrasound images of this organ are acquired in step S 22 .
[0048] FIGS. 3 and 4 show examples of a user interface 30 of an ultrasound imaging system 10 according to the present invention. The figures show only those elements of the user interface 30 that are directly related to the present invention.
[0049] The user interface 30 comprises a user input 18 for entering a patient identifier 26 . The organs for which sets of acquisition parameters for this patient are found are shown in the selection user interface 20 . As shown in FIG. 3 , if for one organ more than one set of acquisition parameters is found, all of the found sets of acquisition parameters can be displayed in the selection user interface 20 and differentiated by showing further information, for example the date when each of the sets of acquisition parameters was stored or when it was used for the last time. In another embodiment (not shown) the selection user interface could indicate that the sets of acquisition parameters correspond to specific (known) lesions of the patient. If an organ has several lesions, there could be different sets of acquisition parameters for the different lesions of one organ. The user can identify one of the sets of acquisition parameters for example by clicking on the corresponding line in the selection user interface 20 . The selection is shown by highlighting the corresponding line 32 . The user interface 30 comprises a Start button 34 and a New button 36 . The start button is visible and enabled as soon as a set of acquisition parameters is found which corresponds to the given patient identifier 36 and for which a matching exchangeable transducer unit 14 has been detected by the transducer sensor unit 15 . The New button is always visible and enabled and allows the user to create a new set of acquisition parameters, as shown in FIG. 5 .
[0050] FIG. 4 shows an example of the user interface 30 in a scenario where for the given patient identifier 26 several corresponding sets of acquisition parameters have been found, but none of them identifies a transducer unit that matches the exchangeable transducer unit 14 that is currently attached to the image acquisition unit 12 . This is indicated for each entry of the selection user interface 20 through a notification unit 24 , which in this case is simply two exclamation marks. The Start button 34 is disabled and the user can not immediately start an image acquisition.
[0051] FIG. 5 shows an example of the user interface 30 that is used for entering a new set of acquisition parameters. The patient identifier 26 is entered in the user input 18 , the organ, for which the set of acquisition parameters is prepared, is selected in the selection user interface 20 . In this embodiment, the selection user interface allows selection an organ from a list of organs. Alternatively, the user can enter a textual description of the organ. Several parameters of the set of acquisition parameters can be entered in the parameter input fields 40 . The Save button 38 and the Start button 34 are enabled as soon as a complete set of acquisition parameters has been entered. In a preferred embodiment of the invention, the Start Button 34 is implemented as a Save and Start button, i.e. the set of acquisition parameters is saved and the acquisition of the ultrasound images is started.
[0052] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
[0053] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
[0054] A computer program may be stored/distributed on a suitable non-transitory medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.
[0055] Any reference signs in the claims should not be construed as limiting the scope.
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The present invention relates to an ultrasound imaging system ( 10 ) and a corresponding method which enable that in subsequent examinations of the same patient ultrasound images are acquired under conditions such that the images can be compared and can be used to monitor disease progression. The proposed ultrasound imaging system ( 10 ) comprises an image acquisition unit ( 12 ) configured to acquire an ultrasound image based on a set of acquisition parameters, a user input ( 18 ) for entering (S 10 ) a patient identifier ( 26 ), a database access ( 28 ) configured to access a database of sets of acquisition parameters, wherein the sets of acquisition parameters are associated with patient identifiers ( 26 ), and a control unit ( 16 ) configured to automatically retrieve (S 12 ) a set of acquisition parameters that is associated with said patient identifier ( 26 ) based on an entered patient identifier ( 26 ) and control the image acquisition unit ( 12 ) to acquire (S 22 ) an ultrasound image based on the retrieved set of acquisition parameters.
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PRIORITY REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Application No. 60/995,575, entitled AUTOMATED CONSUNER ELECTRONICS DEVICE REPORTING, filed on Sep. 26, 2007 by inventors Itay Sherman, Eyal Bychkov, Uri Ron, Hagay Katz and Hagit Perry. This application also claims benefit of U.S. Provisional Application No. 61/062,171, entitled MODULAR WIRELESS COMMUNICATOR, filed on Jan. 23, 2008 by inventors Itay Sherman, Eyal Bychkov, Itay Cohen, Tami Demri, Hagay Katz, Eran Miller, Hagit Perry, Uri Ron and Yaron Segalov. This application also claims benefit of U.S. Provisional Application No. 61/063,668, entitled MODULAR WIRELESS COMMUNICATOR, filed on Feb. 5, 2008 by inventors Dov Moran, Itay Sherman, Eyal Bychkov, Itay Cohen, Yaron Segalov, Tami Demri, Eran Miller, Uri Ron, Hagay Katz and Hagit Perry. This application also claims benefit of U.S. Provisional Application No. 61/080,264, entitled AUTOMATED CONSUNER ELECTRONICS DEVICE REPORTING, filed on Jul. 13, 2008 by inventors Itay Sherman, Eyal Bychkov, Uri Ron, Hagay Katz and Hagit Perry.
FIELD OF THE INVENTION
[0002] The field of the present invention is wireless communication applied to automated maintenance of appliances.
BACKGROUND OF THE INVENTION
[0003] Consumers who buy electrical appliances generally contact the seller or the seller's service provider when the appliance malfunctions, to report a problem and to have the appliance fixed.
[0004] Currently malfunction reporting is performed manually. Specifically, to report an appliance malfunction a consumer generally contacts the seller or service provider by phone or via the Internet. Malfunction reports include information about the appliance and information about the owner of the appliance. Information about the appliance includes a serial number, a model number, a point of purchase and a date of purchase. Information about the owner includes name and contact details.
[0005] Consumer appliances are not generally examined periodically on a regular maintenance schedule. When malfunctions do occur they may be severe and costly. Reporting malfunction of an appliance is often time consuming and cumbersome.
[0006] There is thus a need for monitoring appliances on a regular basis and automatically sending diagnostic reports to service provides, in order to avoid or reduce severity of malfunctions with the appliances. There is also a need for automated methods and systems for reporting malfunctions of electrical appliances.
SUMMARY OF THE DESCRIPTION
[0007] Aspects of the present invention concern automated diagnostic testing and malfunction reporting for electrical appliances. In one embodiment, the present invention employs a communication card that includes a controller, a flash storage memory, a battery, a wireless modem, a power amplifier, and an interface for connecting the card to an appliance.
[0008] The communication card includes program code for diagnostic testing of the appliance. When the communication card is connected to the appliance, the program code runs diagnostic maintenance tests on the appliance. The card automatically collects information about the appliance and its owner, and transmits the collected information along with a diagnostic report, to the seller or service provider for the appliance. In turn, if a malfunction is reported, the seller or service provider contacts the owner about repairing the appliance. In this way, the seller or service provider is able to maintain the appliance, and proactively repair appliance malfunctions before they become severe.
[0009] In addition, the seller or service provider is able to identify the precise problem, act upon accurate information, and send a technician with an appropriate appliance part or instruct the owner by phone how to fix the problem remotely. In distinction, user explanations are often inaccurate.
[0010] In accordance with an embodiment of the present invention, diagnostic maintenance tests may be scheduled periodically, or initiated manually by the owner, or initiated remotely, over the air, by the service provider via the communication card.
[0011] There is thus provided in accordance with an embodiment of the present invention a system for maintaining an appliance, including a storage housed within an electrical appliance for storing identifying information about the electrical appliance and its purchase, and a communication card including an interface connector for connecting the communication card to the electrical appliance, and a wireless cellular modem for transmitting data, wherein when the communication card is connected to the electrical appliance via the interface connector, the communication card causes program code to perform at least one diagnostic test on the electrical appliance and to generate test results, to collect the identifying information about the electrical appliance and its purchase, and to transmit at least a portion of the collected information and the test results to at least one remote recipient using the cellular modem.
[0012] There is additionally provided in accordance with an embodiment of the present invention a method for maintaining an appliance, including connecting a communication card to an electrical appliance, wherein identifying information about the electrical appliance and its purchase is stored within a memory in the electrical appliance, causing at least one diagnostic test to be performed on the electrical appliance, automatically collecting the identifying information about the electrical appliance and its purchase from the memory in the electrical appliance, opening a connection with at least one remote recipient, by the communication card, and transmitting at least a portion of the collected information and the results of the at least one diagnostic test to the at least one recipient, by the communication card.
[0013] There is further provided in accordance with an embodiment of the present invention a system for maintaining an appliance, including a storage housed within an electrical appliance for storing identifying information about the electrical appliance, and a communication card including an interface connector for connecting the communication card to the electrical appliance, and a wireless cellular modem for transmitting data, wherein when the communication card is connected to the electrical appliance via the interface connector, the communication card causes program code to perform at least one diagnostic test on the electrical appliance and to generate test results, to collect the identifying information about the electrical appliance, and to open a TCP connection to a server computer to transmit at least a portion of the collected information and the test results to the server computer using the cellular modem.
[0014] There is further provided in accordance with an embodiment of the present invention a method for maintaining an appliance, including connecting a communication card to an electrical appliance, wherein identifying information about the electrical appliance is stored within a memory in the electrical appliance, causing at least one diagnostic test to be performed on the electrical appliance, automatically collecting the identifying information about the electrical appliance from the memory in the electrical appliance, opening a TCP connection with a server computer, by the communication card, and transmitting at least a portion of the collected information and the results of the at least one diagnostic test to the server computer, by the communication card.
[0015] There is yet further provided in accordance with an embodiment of the present invention a wireless communicator, including an interface configured to enable the wireless communicator to connect to a plurality of different electronic devices, wherein each of the plurality of electronic devices has device information, a memory storing a device diagnostic program, wherein the device diagnostic program includes instructions to perform at least one diagnostic test on the electronic device and to generate test results, a wireless modem configured to transmit and receive data from time to time when the wireless communicator is connected to one of the plurality of different electronic devices and from time to time when the wireless communicator is not connected to any of the plurality of different electronic devices, and a controller coupled to the interface, the memory and the wireless modem, the controller configured to receive the device information from an electronic device connected to the wireless communicator, to execute the device diagnostic program, and to cause the wireless modem to transmit at least a portion of the device information and the test results to a recipient.
[0016] There is moreover provided in accordance with an embodiment of the present invention an electronic device, including an interface configured to enable the electronic device to connect to one of a plurality of wireless communicators and to enable data to be transferred between the electronic device and a wireless communicator connected to the electronic device, a memory storing device information and storing a device diagnostic program, wherein the device diagnostic program includes instructions to perform at least one diagnostic test on the electronic device and to generate test results, and a controller coupled to the interface and the memory, the controller configured to execute the device diagnostic program when a first one of the plurality of wireless communicators is connected to the interface, and to transfer at least a portion of the device information and the test results to a wireless communicator connected to the electronic device, for transmission to a recipient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which:
[0018] FIG. 1 is a simplified illustration of a communications network with a communication card that transmits information about an appliance to a remote manufacturer or seller or service provider, in accordance with an embodiment of the present invention;
[0019] FIG. 2 is a picture of the physical communication card of FIG. 1 , in accordance with an embodiment of the present invention;
[0020] FIG. 3 is a simplified block diagram of a system for a communication card used for diagnostic reporting of electrical appliances, in accordance with an embodiment of the present invention;
[0021] FIG. 4 is a simplified flowchart of a method for reporting diagnostics for electrical appliances using a communication card, in accordance with an embodiment of the present invention; and
[0022] FIG. 5 , which is a simplified block diagram of a web-based device diagnostic system, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0023] Aspects of the present invention relate to a communication card that connects to an electrical appliance and automatically performs various functions for the owner of the appliance. Reference is now made to FIG. 1 , which is a simplified illustration of a communications network with a communication card 100 that wirelessly transmits information about an appliance 200 to one or both of a remote seller and a remote service provider 300 , in accordance with an embodiment of the present invention. Reference is also made to FIG. 2 , which is a picture of a physical communication card 100 , in accordance with an embodiment of the present invention. When communication card 100 is connected to appliance 200 , the communication card (i) automatically runs diagnostic tests on the appliance, and (ii) automatically prepares diagnostic summary reports 320 for the appliance and transmits them to a remote seller, manufacturer or service provider 300 for the appliance.
[0024] Reference is now made to FIG. 3 , which is a simplified block diagram of a system for a communication card 100 used for diagnostic reporting of electrical appliances, in accordance with an embodiment of the present invention. Shown in FIG. 3 is a communication card (CC) 100 and a host electrical appliance 200 , which connect to one another using a host interface 105 and a CC interface 210 . Host interface 105 and CC interface 210 may be a physical interface, such as a USB interface or an SD interface, or a Bluetooth interface or such other wireless interface.
[0025] Main components of CC 100 include a controller 110 , a flash storage memory 115 , a wireless cellular modem 145 , and a power amplifier 150 . CC 100 optionally includes a power subsystem 125 , an input device 130 such as a keypad, and an output display 135 , an audio subsystem 140 , and an optional subscriber identification module (SIM) 170 .
[0026] In accordance with an embodiment of the present invention, memory 115 stores information 121 about the owner of CC 100 . Owner information 121 includes sufficient information for identifying the owner of electrical appliance 200 . In an alternative embodiment of the present invention, information 121 is stored in SIM 170 . Memory 115 also stores program code 122 for reporting diagnostics for host appliance 200 , as described hereinbelow. Modem 145 sends and receives voice and digital data using wireless communication, via an antenna 155 or via an optional wireless LAN 165 , or via both. Power amplifier 150 is used to amplify data transmitted by modem 145 . Power amplifier 150 includes an RF interface 160 .
[0027] In accordance with an embodiment of the present invention, when CC 100 includes the optional components shown in FIG. 3 , then CC 100 functions both as a standalone modular cell phone, and also in cooperation with electrical appliance 200 as a device for automated diagnostics and reporting as described hereinbelow. In accordance with another embodiment of the present invention, when CC 100 does not include the optional components shown in FIG. 3 , then CC functions only in cooperation with electrical appliance 200 .
[0028] Electrical appliance 200 may be any of a wide variety of devices. Electrical appliance 200 may be an entertainment device, including inter alia a home entertainment center, a play station, a multimedia player, a television, an audio system and a DVD player. Electrical appliance 200 may be a communication device, including inter alia a telephone, a fax machine and a cell phone. Electrical appliance 200 may be a piece of office equipment including inter alia an office computer, and printer and a scanner. Electrical appliance 200 may be a home appliance including inter alia a refrigerator, a microwave oven, a stove, a washing machine, a drying machine, an air conditioner. Electrical appliance 200 may be a consumer appliance including inter alia a personal computer, a personal data assistant (PDA), an automobile, a treadmill and a camera. Generally, electrical appliance 200 includes a user interface 220 for activating functions of appliance 200 , and a storage memory 230 for recording information 240 about the electrical appliance and its purchase. Such details may include inter alia a serial number for appliance 200 , a model number, a software/firmware version, a date of purchase and an identifier for the store where appliance 200 was purchased.
[0029] In accordance with an embodiment of the present invention, electrical appliance 200 includes sensors 250 for use in diagnostics. A sensor is a type of transducer which converts a signal into a reading for the purpose of information transfer. There are direct-indicating sensors which are human-readable, e.g., a mercury thermometer. Other sensors that may be embedded in an electrical appliance are sensors that produce an output voltage or such other electrical output which is interpreted by another device. Most sensors are electrical or electronic, although other types exist. Sensors used in diagnostics of appliance 200 in accordance with the present invention include inter alia thermal sensors, electromagnetic sensors, mechanical sensors, chemical sensors, optical radiation sensors, ionizing radiation sensors and acoustic sensors. CC 100 is used to send information about electrical appliance 200 and its owner to one or more of the seller, manufacturer and service provider 300 . The information sent by CC 100 includes diagnostic reports for appliance 200 . When CC 100 is connected to appliance 200 , appliance 200 serves as a host device. For maintenance and repair of appliance 200 , diagnostic program code 122 programs CC 100 (i) to run diagnostic tests on appliance 200 ; and (ii) to forward the test results to the seller, to the manufacturer or to the service provider 300 for appliance 200 , as appropriate, using modem 145 . As above, CC 100 creates a file or text message that includes the relevant diagnostic monitoring data, shown as service report 320 in FIG. 1 . An example of such file or text message is as follows.
[0000]
Device details
Type: Audio Receiver
Brand: Yamaha
Model: RX-V2700
S/N: 12345-ABCDE
Problem Diagnosed
Description: Over-heating
Owner Details
Name: John Smith
Phone: 123-456-7890
Cell: 098-765-4321
Email: John.Smith@anonymous.com
[0030] In another embodiment of the present invention, CC 100 transmits the service report via an e-mail message. In yet another embodiment of the present invention, CC 100 transmits the service report via an SMS or MMS message. In yet another embodiment of the present invention, CC 100 places a voice call to the seller, manufacturer or service provider 300 with the information indicated in the text above, using text-to-speech conversion.
[0031] In accordance with an embodiment of the present invention, diagnostic tests may be scheduled periodically, or initiated manually by the owner, or initiated remotely via the CC.
[0032] Reference is now made to FIG. 4 , which is a simplified flowchart of a method for reporting diagnostics for electrical appliances using a communication card, in accordance with an embodiment of the present invention. At step 410 a consumer inserts a communication card into an electronic appliance, which serves as a host device for the CC. At step 420 the CC monitors the appliance by running diagnostic testing program code that is stored in memory of the CC. At step 430 a determination is made whether a problem has been detected. If not, the method returns to step 420 to continue monitoring the appliance while the CC is connected thereto. Such monitoring may be continuous monitoring or scheduled periodic monitoring.
[0033] Referring back to step 430 , if a problem is detected, then at step 440 the CC controller collects host appliance information that is stored in a host memory. Such information includes inter alia an appliance serial number and a model number. The CC controller also identifies a malfunction type corresponding to the detected problem. At step 450 the CC controller collects owner data that is stored in memory of the CC or in the SIM of the CC. At step 460 the CC controller collects contact information for the seller, manufacturer or service provider of the host appliance. At step 470 the CC contacts the seller or service provider and transmits an alert notification regarding the malfunction. Finally, at step 480 the seller, manufacturer or service provider contacts the owner of the appliance regarding the malfunction.
[0034] In another embodiment of the present invention, instead of or in addition to generating reports, CC 100 sends diagnostic information it collects to a server computer. In this regard, reference is now made to FIG. 5 , which is a simplified block diagram of a web-based device diagnostic system, in accordance with an embodiment of the present invention.
[0035] A server computer 500 includes a database with serial numbers, or such other identifiers of electrical appliances 200 , and information about their corresponding manufacturers, sellers or service providers 300 . When CC 100 generates diagnostic reports, triggered by malfunctions or by routine maintenance schedules, CC 100 opens a TCP connection and generates an HTTP request to computer server 500 , the request including inter alia the serial number of appliance 200 , contact information, such as a telephone number, for the owner, and a malfunction descriptor. An example of such an HTTP call is:
[0000]
http://www.myserver.com/action.aspx?action=diagnostic&serial=
89723464&phone=+155512122&error=overheating.
[0036] Server information for computer server 500 , including inter alia a server URL, which may be a server IP address, a server domain name, or such other locator, is generally stored in CC 100 .
[0037] Also shown in FIG. 5 is an application programming interface (API). After receiving the HTTP request with the serial number of appliance 200 , server computer 500 locates the relevant information about manufacturer, seller or service provider 300 for the serial number, and transmits a diagnostic report for appliance 200 to manufacturer, seller and service provider 300 , via the API. The diagnostic report may be transmitted ad-hoc, in the case of a malfunction, or routinely. In this way, manufacturer, sellers and service providers 300 receive diagnostic reports for the appliances 200 that they are responsible for. This embodiment is described as “push” mode, since server computer 500 pushes the diagnostic reports to manufacturers, sellers and service providers 300 .
[0038] In accordance with a “pull” mode embodiment of the present invention, manufacturer, seller or service provider 300 uses the API to access server computer 500 and extract diagnostic reports for the appliances 200 that they are responsible for from a website 510 . In this embodiment, manufacturers, sellers or service providers 300 pull their diagnostic reports from website 510 .
[0039] Use of server computer 500 is of particular advantage when manufacturer, seller or service provider 300 changes its contact information. The change is recorded once in server computer 500 , and does not need to be changed in appliances 200 .
[0040] Additionally, server computer 500 may vary the format of messages sent to manufacturer, seller or service provider 300 , so that diagnostic reports are transmitted via SMS, MMS, phone call, e-mail, HTTP request, or such other transmission format.
[0041] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific exemplary embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
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A system for maintaining an appliance, including a storage housed within an electrical appliance for storing identifying information about the electrical appliance and its purchase, and a communication card including an interface connector for connecting the communication card to the electrical appliance, and a wireless cellular modem for transmitting data, wherein when the communication card is connected to the electrical appliance via the interface connector, the communication card causes program code to perform at least one diagnostic test on the electrical appliance and to generate test results, to collect the identifying information about the electrical appliance and its purchase, and to transmit at least a portion of the collected information and the test results to at least one remote recipient using the cellular modem. A method is also described and claimed.
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This application is based on Japanese Patent Application No. Hei 11-35514 filed in Japan on Feb. 15, 1999, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for forming an image and, more particularly, to an apparatus and method for forming an image by causing ink to jump from a thin layer of conductive ink held on an ink holding member in accordance with an electrostatic latent image on a latent image carrying member or with a recording voltage applied to a recording electrode and attaching the ink indirectly or directly to a recording medium.
2. Description of Related Art
There has conventionally been known an apparatus which forms an image by causing ink drops to jump, under a Coulomb's force, from a thin layer of conductive ink formed on an ink holding member to an electrostatic latent image on a latent image carrying member, developing the electrostatic latent image with the ink drops, and transferring an ink image formed by the development to a recording medium such as a sheet of paper.
In the image forming apparatus of this type, it is extremely important for the formation of a high-resolution image to reduce the size of an ink drop which jumps from the ink holding member toward the latent image carrying member and thereby reduce the diameter of a dot on the latent image carrying member and on the recording medium.
OBJECT AND SUMMARY
An object of the present invention is to provide an improved apparatus and method for forming an image whereby the foregoing problems are solved.
The foregoing object is attained by providing an image forming apparatus comprising:
a latent image carrying member for carrying an electrostatic latent image on a surface thereof;
an ink holding member disposed in opposing relation to the latent image carrying member and holding a thin layer of conductive ink on a surface thereof, the surface of the ink holding member being formed of a conductive material and having a plurality of projecting portions; and
a voltage applying unit for applying, to the projecting portions, a voltage of polarity different from that of a potential of the electrostatic latent image and thereby causing the ink to jump from the projecting portions located in opposing relation to the electrostatic latent image toward the electrostatic latent image,
wherein the following weak inequality is satisfied
(h1+h2-h3)/(h1+h2)≧0.1,
where h1 represents height of each of the projecting portions,
h2 represents thickness of the thin layer of ink on each of the projecting portions, and
h3 represents thickness of the thin layer of ink between the projecting portions.
The foregoing object is attained by further providing an image forming apparatus comprising:
an electrode unit having a plurality of electrodes to each of which a voltage is applied individually;
an ink holding member disposed in opposing relation to the electrode unit and holding a thin layer of conductive ink on a surface thereof, the surface of the ink holding member being formed of a conductive material and having a plurality of projecting portions; and
a voltage applying unit for applying, to the projecting portions, a voltage of polarity different from that of the voltage applied to the electrodes and thereby causing the ink to jump from the projecting portions located in opposing relation to the electrodes to which the voltage is applied toward the electrodes to which the voltage is applied,
wherein the following weak inequality is satisfied
(h1+h2-h3)/(h1+h2)≧0.1,
where h1 represents height of each of the projecting portions,
h2 represents thickness of the thin layer of ink on each of the projecting portions, and
h3 represents thickness of the thin layer of ink between the projecting portions.
The foregoing object is attained by further providing an image forming method comprising the steps of:
(1) selectively generating a potential depending on an image to be formed at a position opposed to an ink holding member, wherein a surface of the ink holding member is formed of a conductive material and has a plurality of projecting portions;
(2) forming, on the surface of the ink holding member, a thin layer of conductive ink such that the following weak inequality is satisfied,
(h1+h2-h3)/(h1+h2)≧0.1,
where h1 represents height of each of the projecting portions,
h2 represents thickness of the thin layer of ink on each of the projecting portions, and
h3 represents thickness of the thin layer of ink between the projecting portions; and
(3) applying a voltage of polarity different from that of the potential generated in the step (1) to the projecting portions and thereby causing the ink to jump from the projecting portions located in opposing relation to a position at which the potential is generated to the position at which the potential is generated.
In each of the foregoing apparatus and method, the height of the projecting portion is preferably in the range of 10 μm to 100 μm.
In each of the foregoing apparatus and method, the plurality of projecting portions may be arranged as a matrix or in a staggered pattern on the surface of the ink holding member.
In each of the foregoing apparatus and method, the ink having a viscosity of 1000 cP or less and a surface tension of 50 dyne/cm or less is particularly preferred.
In the apparatus and method for forming an image according to the present invention, the voltage of polarity different from that of the potential of the electrostatic latent image or of the voltage applied to the electrode is applied to the projecting portions on the surface of the ink holding member. When the ink holding member is opposed to, e.g., the electrostatic latent image on the latent image carrying member in this state, charge of the polarity opposite to that of the potential of the latent image is induced collectively on the tip of each of the projecting portions by electrostatic induction, which is injected in the thin layer of conductive ink on each of the projecting portions. An electric field is formed between the thin layer of conductive ink and the electrostatic latent image due to the difference between the charge thus injected in the thin layer of conductive ink and the charge of the electrostatic latent image. By the action of the electric field, a Coulomb's force directed toward the electrostatic latent image is exerted on the ink on the periphery of each of the projecting portions. This causes the ink to swell up on the projecting portion and form a meniscus.
When the meniscus is formed, if the thin layer of ink is formed to satisfy the conditional inequality (h1+h2-h3)/(h1+h2)≧0.1, a relatively small meniscus is formed on the projecting portion. When the injected charge converges on the tip of the small meniscus and the Coulomb's force exerted on the tip thereof is further increased, a small ink drop is separated from the tip of the small meniscus to jump. The jumped ink drop is temporarily attached to the electrostatic latent image to form an ink image and then transferred onto a recording medium to form an image or, alternatively, the jumped ink drop is attached directly to the recording medium to form an image.
Thus, in the apparatus and method for forming an image according to the present invention, the meniscus is formed on the thin layer of ink on each of the projecting portions opposed to the electrostatic latent image or to the electrode to which the voltage is applied. Accordingly, the ink is more likely to jump even if the electric field is not so intense. Since stable jumping of the ink is performed even when the potential of the electrostatic latent image or the voltage applied to the electrode is reduced, a driving circuit system as well as a power supply unit for charging the latent image carrying member or applying a voltage can be scaled down, simplified, and power-saved, which leads to lower cost.
Since the apparatus and method for forming an image according to the present invention has formed the thin layer of ink to satisfy the foregoing conditional inequality, a relatively small meniscus can be formed on the projecting portion of the ink holding member. Accordingly, a small ink drop is allowed to jump from the meniscus. This reduces the size of a dot formed on the latent image carrying member or on the recording medium and increases the resolution of an image.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:
FIG. 1 is a view showing a schematic structure of an image forming apparatus as an embodiment of the present invention;
FIG. 2 is a view showing in detail an ink developing unit;
FIGS. 3(a) to 3(d) are partially enlarged cross-sectional views of projecting portions on a surface of an ink holding
roller;
FIGS. 4(a) and 4(b) are partially enlarged plan views showing respective arrangement patterns for the projecting portions on the ink holding roller;
FIG. 5(a) is an enlarged cross-sectional view of the portion C of FIG. 2;
FIG. 5(b) is an enlarged cross-sectional view of the portion D of FIG. 2;
FIG. 6 is a view for illustrating the principle of ink jumping from the positions corresponding to the projecting portions on the ink holding roller;
FIG. 7(a) is a view showing the process in which a meniscus is formed on the projecting portion and the ink jumps when the thin layer of ink is formed to satisfy the conditional inequality of the present invention;
FIG. 7(b) is a view showing the process in which a meniscus is formed on the projecting portion and the ink jumps when the thin layer of ink is formed not to satisfy the conditional inequality of the present invention;
FIG. 8 is a view showing a schematic structure of an image forming apparatus according to another embodiment of the present invention;
FIG. 9 is a view showing the ink jumped from the positions corresponding to the projecting portions on the ink holding roller and attached directly to a sheet of paper;
FIG. 10 is a view showing a schematic structure of an image forming apparatus according to still another embodiment of the present invention;
FIG. 11 is a partially enlarged view of a recording electrode; and
FIG. 12 is a view showing a schematic structure of an image forming apparatus using a belt as an ink holding member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the accompanying drawings, preferred embodiments of the present invention will be described.
FIG. 1 is a schematic structural view of an image forming apparatus 10 as an embodiment of the present invention. The image forming apparatus 10 comprises a photosensitive drum 12 as a latent image carrying member. The photosensitive drum 12 is so constituted as to be rotatively driven in the direction indicated by the arrow A. Around the photosensitive drum 12, there are: a corona charging unit 14 for uniformly charging a surface of the photosensitive drum 12; an exposing unit 16 for forming an electrostatic latent image by exposing the surface of the photosensitive drum 12 charged uniformly to remove the charge of the exposed portion and leave the charge of the unexposed portion; an ink developing unit 18 for developing the formed electrostatic latent image with conductive ink; a transfer roller 20 for transferring the developed ink image onto a sheet S as a recording medium; a cleaning unit 22 for recovering the ink remaining on the surface of the photosensitive drum 12 after transfer; and
a destaticizing unit 24 for erasing the electrostatic latent image, which are disposed successively in the direction of rotation of the photosensitive drum 12.
A method of forming an electrostatic latent image is not limited to the foregoing exposing method. Another method such as an ion flow method, a pyroelectric method, or a method of polarizing a ferroelectric material with heat or electricity may also be used to form the electrostatic latent image. It is also possible to form a large number of microelectrodes over the entire surface of the drum. These techniques are well known. Optionally, an ink fixing unit for drying and fixing the ink image transferred onto the sheet S may also be provided, though it is not shown in the drawing.
As shown in FIG. 2, the ink developing unit 18 includes a casing 26 having an opening opposed to the photosensitive drum 12. Conductive ink 28 is contained within the casing 26. The ink holding roller 30 as an ink holding member is disposed in the opening of the casing 26 to be rotatively driven in the direction indicated by the arrow B. A seal roller 32 is disposed between an upper edge portion 26a of the casing 26 and the ink holding roller 30 to prevent the leakage and drying of the ink. If necessary, an ink-thin-layer stabilizing blade 34 may also be provided at the upper edge portion of the casing 26 opposite to the seal roller 32 relative to the ink holding roller 30.
The ink holding roller 30 has at least a surface layer portion formed of a conductive material. The surface of the ink holding roller 30 is formed with a large number of extremely small projecting portions 40 (see FIGS. 3(a) to 3(d) and FIGS. 4(a) and 4(b)). The projecting portions 40 may be formed by processing the surface of a metal roller by cutting, etching, or electric casting or by forming a resin roller with projecting portions and then covering the entire surface of the roller with a metal thin film by sputtering or the like. The ink holding roller 30 is electrically connected to an offset power supply 38, whereby a specified voltage of polarity different from that of the potential of the latent image, e.g., positive polarity is applied to each of the projecting portions 40 on the ink holding roller 30. The ink holding roller 30 may also be grounded directly such that the ground voltage is used as the specified voltage.
In FIG. 3(a) is shown a partially enlarged cross-sectional view of the surface of the ink holding roller 30 when it is axially cut. Since each of the projecting portions 40 is configured as a cylinder or a rectangular parallelepiped, it has a rectangular cross section. The projecting portions 40 are arranged with an equal pitch p to form a matrix over the entire surface of the ink holding roller 30 (see FIG. 4(a)). The pitch p of the projecting portions 40 is preferably in the range of 20 to 100 μm. This is because, if the pitch p is smaller than 20 μm, an ink thin layer with a rough surface which satisfies a conditional inequality described later becomes less likely to be formed and, if the pitch p is larger than 100 μm, a jumping ink drop increases in size and reduces resolution. The ratio of the width a of each of the projecting portions 40 to the width b of each of depressed portions 42 (portions between the projecting portions) need not necessarily be 1:1 provided that it is in the range of a:b=7:3 to 3:7. This is because, if the proportion of the width a of the projecting portion 40 is under the foregoing range, manufacturing becomes difficult and, if the proportion of the width a of the projecting portion 40 is over the foregoing range, resolution is reduced. The height h1 of each of the projecting portions 40 is preferably in the range of 10 to 100 μm. This is because, if the height h1 is smaller than 10 μm, an ink thin layer with a rough surface which satisfies the conditional inequality described later becomes less likely to be formed and, if the height h1 is larger than 100 μm, manufacturing becomes difficult.
The configuration of the projecting portion 40 is not limited to a cylinder or a rectangular parallelepiped. It may have another configuration such as a hemispherical configuration with a generally semicircular cross section, as shown in FIG. 3(b). It may have a conical or pyramidal configuration with a triangular cross section, as shown in FIG. 3(c). It may have a truncated conical or truncated pyramidal configuration with a trapezoidal cross section, as shown in FIG. 3(d). If the cross section of the projecting portion 40 is trapezoidal as shown in FIG. 3(d), the width d of the upper side thereof is preferably in the range of 2 to 30 μm. If the cross section of the projecting portion 40 is rectangular, triangular, trapezoidal, or the like, the end face or side face of the projecting portion 40 may be curved. Although the projecting portions 40 have been arranged to form a matrix on the surface of the ink holding roller 30, as shown in FIG. 4(a), they may also be arranged in a staggered pattern, as shown in FIG. 4(b), or may be arranged in a given pattern other than the foregoing.
Next, a description will be given to the operation of the image forming apparatus 10 thus constituted. In the ink developing unit 18, the ink holding roller 30 is rotatively driven in the direction indicated by the arrow B, while having the lower portion thereof immersed in the ink 28. As a result, the ink 28 is applied to the surface of the ink holding roller 30 to form the ink thin layer 36.
If the ink 28 with a low viscosity is used, extra ink falls by gravitation in the direction indicated by the arrow E along the surface of the ink holding roller 30 adjacent the liquid level of the ink 28 and returns to an ink reservoir, as shown in FIG. 5(a) which is an enlarged view of the portion C of FIG. 2.
On the other hand, the ink thin layer 36 has been formed on the surface of the ink holding roller 30 opposed to the photosensitive drum 12, as shown in FIG. 5(b). The ink thin layer 36 has been formed to satisfy the conditional inequality (h1+h2-h3)/(h1+h2)≧0.1 if the height of each of the projecting portions 40 is hl, the thickness of the ink layer on each of the projecting portions 40 is h2, and the thickness of the ink layer between the projecting portions 40, i.e., in each of the depressed portions 42 is h3. In the case where the conditional inequality is satisfied, the ink thin layer 36 is formed to have a surface swelling up in conformity with the projecting portions 40 and being dented to a certain depth (e.g., several micrometers) or more in conformity with the depressed portions 42. To the contrary, if the ink thin layer 36 is formed to have a flat, smooth surface covering each of the projecting portions 40, the conditional inequality is not satisfied.
To form the foregoing ink thin layer 36 with the rough surface, the ink viscosity is preferably 1000 cP or less. If the ink viscosity is higher than 1000 cP, the fluidity of the ink is lowered and the rough surface in conformity with the projecting portions 40 and the depressed portions 42 becomes less likely to be formed. The surface tension of the ink is preferably 50 dyne/cm or less. If the surface tension of the ink is higher than 50 dyne/cm, the ink on the projecting portions 40 is separated from the ink within the depressed portions 42 so that the ink thin layer 36 with the rough surface covering the projecting portions 40 and depressed portions 42 without a break becomes less likely to be formed.
As shown in FIG. 6, a specified positive voltage is applied from the offset power supply 38 to each of the projecting portions 40 on the ink holding roller 30. In this condition, when each of the projecting portions 40 covered with the ink thin layer 36 is opposed to an electrostatic latent image portion on the photosensitive drum 12, charge of polarity opposite to that of the potential of the latent image, e.g., positive charge is induced on the tip of each of the projecting portions 40 at positions opposed to the latent image by electrostatic induction and injected into the ink thin layer 36 on each of the projecting portions 40. An electric field is formed between the conductive ink thin layer 36 and the photosensitive drum 12 due to the difference between the positive charge injected into the conductive ink thin layer 36 and the negative charge of the electrostatic latent image on the photosensitive drum 12. By the action of the electric field, a Coulomb's force directed toward the electrostatic latent image portion is exerted on the ink on each of the projecting portions 40, whereby the ink on the projecting portion 40 swells up to form a meniscus 52.
In thus forming the meniscus 52, if the ink thin layer 36 has a flat, smooth surface, i.e., if the foregoing conditional inequality is not satisfied as shown in FIG. 7(b), the ink on the periphery of the projecting portion 40 not only moves along the projecting portion 40 but also moves to swell up on the projecting portion 40 in the directions indicated by the arrows 44, 46 at the surface layer portion of the ink thin layer 36. As a result, a relatively large meniscus 52 is formed on the projecting portion 40. Since the larger meniscus 52 has a tip closer to the photosensitive drum 12, a larger Coulomb's force is exerted on the tip so that a relatively large ink drop 54 is separated to jump. By contrast, since the ink thin layer 36 of the present embodiment has been formed to have a rough surface by reducing the thickness of the ink in the depressed portions 42 such that the foregoing conditional inequality is satisfied, as shown in FIG. 7(a), the ink on the periphery of the projecting portion 40 is allowed only to move along the projecting portion 40 as indicated by the arrow in the drawing and the meniscus 52 formed on the projecting portion 40 is relatively small. Accordingly, the tip of the smaller meniscus 52 is at a distance from the photosensitive drum 12, i.e., at a position receiving a weak Coulomb's force. As a result, a small ink drop 54 is separated from the small meniscus 52 to jump.
The ink drop 54 that has jumped from the meniscus 52 is attached to and develops the electrostatic latent image, whereby an ink image is formed on the photosensitive drum 12. Thereafter, the ink image is transferred onto the sheet S to form an image. Thus, in the image forming apparatus 10 of the present embodiment, the ink drop that has jumped from the ink holding roller 30 is temporarily attached to the electrostatic latent image on the photosensitive drum 12 to form the ink image, which is then transferred onto the sheet S. In short, the ink drop from the ink holding roller 30 is attached indirectly to the sheet S to form an image.
As described above, the image forming apparatus 10 of the present embodiment forms the meniscus 52 at the ink thin layer 36 on each of the projecting portions 40 opposed to the electrostatic latent image, so that the ink is more likely to jump even if the electric field is not so intense. This allows stable jumping of the ink even when the potential of the electrostatic latent image is lowered, while downscaling, simplifying, and power-saving the power supply and driving circuit system for the charging unit 14 for charging the photosensitive drum 12, leading to lower cost.
Since the ink thin layer has been formed to satisfy the conditional inequality in the image forming apparatus 10, the relatively small meniscus 52 can be formed on the projecting portion 40 of the ink holding roller 30 and the small ink drop 54 is allowed to jump from the meniscus 52. This reduces the size of the dot formed on the photosensitive drum 12 or on the sheet S and increases the resolution of an image.
Here, an experiment on the jumping of the ink was conducted by using the image forming apparatus 10 of the present embodiment under the following conditions. As the photosensitive drum 12, an OPC photosensitive drum was used. The charge potential on the photosensitive drum 12 (i.e., the potential of the electrostatic latent image) was set to -300 V and the developing speed (i.e., the peripheral speed of the photosensitive drum) was set to 200 mm/sec. The diameter and peripheral speed of the ink holding roller 30 were set to 100 mm and 200 mm/sec, respectively. The pitch p of the projecting portions 40 on the ink holding roller 30 was set to 50 μm. The ratio a:b of the respective widths of the projecting portion 40 and the depressed portion 42 was set to 1:1. The height h1 of the projecting portion 40 was set to 20 μm. The ink thin layer 36 was formed such that the thickness h2 of the ink on the projecting portion 40 was 10 μm and the thickness h3 of the ink in the depressed portion 42 between the projecting portions 40 is 15 μm. In this case, the value on the left side of the conditional inequality becomes (h1+h2-h3)/(h1+h2)=(20+10-15)/(20+10)=0.5, which satisfies the conditional inequality. To each of the projecting portions 40, a voltage of 1.5 kv was applied from the offset power supply 38. The development gap g (See FIG. 6) was set to 500 μm. The conductive ink used contains 10 wt % of any one of carbon black (black), chromophthal yellow (yellow), quinacridone magenta (magenta), and copper phthalocyanine blue (cyan), 86.99 wt % of water as a solvent, 0.01 wt % of a fluorine surface active agent as a surface active agent, 2 wt % of polyethylene glycol as a viscosity modifier, 1 wt % of styrene acrylate as a dispersant. The experiment was conducted under these conditions, with the result that the ink jumped excellently toward the electrostatic latent image. The diameter of the dot formed with the jumped ink was 30 to 35 μm.
By contrast, a control experiment was performed under the same conditions as the foregoing experiment, except that the thickness h2 of the ink in the depressed portion 42 between the projecting portions 40 was adjusted to 30 μm. In this case, the ink thin layer 36 had a flat, smooth surface so that the value on the left side of the conditional inequality was 0 and did not satisfy the conditional inequality. As a result, a crosstalk phenomenon which is mutual interference caused between the adjacent projecting portion 40 upon the jumping of the ink frequently occurred in the control experiment and the diameter of the dot formed with the jumped ink was approximately 50 μm or larger. Thus, the image forming apparatus 10 of the present embodiment allows stable jumping of the ink, formation of a small dot, and achievement of higher resolution.
Next, an image forming apparatus 60 as another embodiment of the present invention will be described with reference to FIGS. 8 and 9. In contrast to the foregoing image forming apparatus 10 which has formed an image by attaching the ink drops jumped from the ink holding roller 30 indirectly to the sheet S, the image forming apparatus 60 of the present embodiment forms an image by attaching the ink drops jumped from the ink holding roller 30 directly to the sheet S. Accordingly, the image forming apparatus 60 has been adapted to transport the sheet S between the photosensitive drum 12 and the ink developing unit 18 disposed in opposing relation to each other, while keeping the sheet S in contact with the photosensitive drum 12. As for the other components, they are substantially the same as in the foregoing image forming apparatus 10 except that the provision of the cleaning unit 22 can be omitted since the ink is prevented from being attached to the photosensitive drum 12. If necessary, a pair of adhesion rollers 62, 64 may also be provided to increase adhesion of the sheet S to the photosensitive drum 12.
The principle of ink jumping in the image forming apparatus 60 is the same as described above with reference to FIGS. 6 and 7. As shown in FIG. 9, ink drops 54 jump from the positions corresponding to the projecting portions 40 on the ink holding roller 30 toward the latent image portion of the photosensitive drum 12 to be attached directly to the sheet S, thereby forming an image. The image forming apparatus 60 of the present embodiment can also achieve the same effects as achieved by the image forming apparatus 10.
Next, an image forming apparatus 70 as still another embodiment of the present invention will be described with reference to FIGS. 10 and 11. In the image forming apparatus 70, a recording electrode 72 is disposed in opposing relation to the ink holding roller 30 of the ink developing unit 18 with intervention of the sheet S. The sheet S is transported in the direction indicated by the arrow, while keeping contact with the lower portion of the recording electrode 72. As shown in FIG. 11, the recording electrode 72 is composed of a large number of discrete electrodes 74 regularly spaced in a direction orthogonal to the direction of sheet transportation and a protective insulating portion 76 covering the periphery of each of the discrete electrodes 74. The discrete electrodes 74 are arranged with a density corresponding to the pixel density of an image and have respective tip portions in contact with the sheet S. The discrete electrodes 74 are connected to a power supply 80 via individual switches 78. Each of the switches 78 is selectively turned ON based on image data to apply a recording voltage of negative polarity to the discrete electrodes 74 corresponding to the position to which the ink should be caused to jump and attached. Although FIG. 11 shows an exemplary structure of the recording electrode 72, the recording electrode 72 is not limited to the embodiment and a multistylus electrode in another embodiment may also be used.
The principle of ink jumping in the image forming apparatus 70 is the same as in the case of the image forming apparatus 60, except that the photosensitive drum 12 has been replaced by the recording electrode 72 and the latent image portion having negative charge has been replaced by the discrete electrode 74 to which the recording voltage of negative polarity is applied. When the recording voltage is applied to the discrete electrode 74, an ink drop jumps from the position corresponding to the projecting portion 40 of the ink holding roller 30 opposed thereto, so that the ink drop is applied directly to the sheet S to form an image. Since the image-forming apparatus 70 of the present embodiment also uses the ink developing unit 18, the same effects as achieved by the image forming apparatus 10 can be achieved.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
For example, although each of the image forming apparatus 10, 60, and 70 described above has used the roller 30 as the ink holding member, an ink holding belt 48 having a surface configuration similar to that of the ink holding roller 30 may be used instead in the ink developing unit 18a, as shown in FIG. 12.
Although the polarity of the electrostatic latent image or recording voltage has been negative in the foregoing description, the present invention is also applicable to the case where the polarity of the electrostatic latent image or recording voltage is positive.
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An image forming apparatus includes a latent image carrying member that carries an electrostatic latent image on a surface thereof, and an ink holding member that is disposed in opposing relation to the latent image carrying member and holds a thin layer of conductive ink on a surface thereof. The surface of the ink holding member is formed of a conductive material and has a plurality of projecting portions. The image forming apparatus further comprising a voltage applying unit that applies, to the projecting portions, a voltage of polarity different from that of a potential of the electrostatic latent image and thereby causes the ink to jump from the projecting portions located in opposing relation to the electrostatic latent image toward the electrostatic latent image. In the image forming apparatus, the following weak inequality is satisfied:
(h1+h2-h3)/(h1+h2)≧0.1,
where h1 represents height of each of the projecting portions, h2 represents thickness of the thin layer of ink on each of the projecting portions, and h3 represents thickness of the thin layer of ink between the projecting portions.
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BACKGROUND OF THE INVENTION
The present invention relates to interconnecting an array of electrical contacts with discrete wires, and more particularly to discrete wire interconnection of a bank of card edge connectors. In use the connectors pluggably receive the edges of printed circuit cards therein. The connectors are provided with electrical contacts, first ends of which engage the printed circuit cards. Opposite ends of the contacts are called tails and project outwardly of the connectors for interconnection by discrete wires. In the past the tails were in the form of posts which were interconnected by wrapping wires around the posts. There has been a long existing need for a system which eliminates the time consumption required for making wrapping type connections and which eliminates wire entanglement.
BRIEF DESCRIPTION
In the present invention the card edge contacts are provided with tail portions in the form of slotted plate contacts into which may be connected one or a pair of interconnection wires. Wire connections are made quickly by inserting a discrete wire along a contact slot, as opposed to the time consuming procedure of wrapping the wire around the contact tail. Resilient slicing jaws are provided adjacent each side of a contact slot which slice through the insulation sheath of a wire to make electrical contact with the wire conductor. The connector block defines wire alignment passageways into which the wires are laced and thereby aligned for insertion in slotted contacts. The passageways also arrange the wires in an orderly array to prevent wire entanglement. The wire aligning passageways include ribs which grip the wire to provide strain relief. A passive keeper or retention gate in the passageways prevent removal of the wires therefrom. Certain contact tail portions are bussed together by common bussing wires. In such cases the bussing wires are readily identified and arranged in orderly array separate from the remainder of interconnecting wires. This is accomplished by wire alignment channels provided on each connector block which support bussing wires in an elevated plane with respect to the remainder of the interconnecting wires. Passive keepers provided on the connector blocks prevent removal of the bussing wires from the alignment channels. Both the passageways and channels are substantially elongated in a direction transversely of the connector block to support and align corresponding lengthy sections of the interconnecting and bussing wires in orderly arrays. It has been found that the substantial lengthy passageways and channels provide relatively large targets which are easy to see and find upon aligning and inserting wires therein. Wiring mistakes and operator fatigue are thereby reduced.
OBJECTS
It is an object of the present invention to provide a connector block having contacts with slotted plate tail portions projecting outwardly of the block for connection of discrete wires thereto, the block including wire alignment passageways and elevated wire alignment channels supporting wires in plural planes and arranging the wires in an orderly array.
Another object of the present invention is to provide a wiring system for a bank of connector blocks which are capable of interconnection by discrete wires, the blocks including rows of electrical contacts therein having outwardly projecting tail portions to which wire insertion connections may be made, the block further including wire alignment passageways providing target areas for aligning wires prior to insertion in the contact tail portions and for captivating inserting wires in place, the block further including elevated wire alignment channels for aligning and supporting additional interconnection wires in a plane elevated above the wire alignment passageways and for captivating the additional wires in an orderly arrangement.
Another object of the present invention is to provide a connector block with electrical contacts having slotted plate tail portions projecting outwardly of the block and capable of interconnection by discrete wires, the block including wire alignment passageways providing target areas for aligning the wires prior to insertion in the slotted plates and for captivating and aligning inserted wires in an orderly array, the block further including wire alignment channels for captivating and arranging additional wires in an orderly array within a plane elevated with respect to the wire alignment passageways.
Other objects and many attendant advantages of the present invention will become apparent from the detailed description and accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged fragmentary perspective of a connector block according to the present invention, with preferred embodiments of the wiring system incorporated therein.
FIG. 2 is an enlarged transverse section taken along the line 2--2 of FIG. 1.
FIG. 3 is an enlarged fragmentary perspective of a portion of the preferred embodiment illustrated in FIG. 1 illustrating the wiring system portion thereof.
FIG. 4 is an enlarged perspective of an electrical contact provided in the connector block of the preferred embodiment and further illustrating a tail portion in the form of a slotted plate contact incorporated into the wiring system portion as illustrated in FIG. 3.
DETAILED DESCRIPTION
With more particular reference to the drawings there is illustrated in FIGS. 1 and 2 a preferred embodiment of a connector block generally illustrated at 1 which is molded from insulation material and includes a generally elongated housing portion 2 with two parallel elongated sidewalls 4 and 6. The housing 2 includes an inner enlarged cavity 8 in which are mounted two rows of opposed electrical contacts generally illustrated at 10, the details of which will be described in detail. The housing 2 further includes an elongated inner cavity 12 of reduced width for slidably receiving therein an edge margin of a printed circuit board or card 14. In accordance with standard practice, the contacts 10 are capable of resilient deflection within the cavity 8 toward and away from the cavity 12. When the printed circuit card 14 is inserted into the cavity 12 and between the rows of contacts 10, the contacts will resiliently engage circuit paths provided on the card providing electrical connection thereto as desired.
As more particularly shown in FIGS. 2 and 4 each contact 10 is provided at one end with a pair of tines 16 which are resilient cantilever beam wiping contacts mounted in opposed rows within the housing portion 2. Each contact 10 further includes a central portion 18 from which is struck out a tine 20. The other end of each contact 10 includes a tail portion 22 in the form of a slotted plate contact portion 22 of the type described in detail in U.S. Pat. No. 3,950,062. The slotted plate 22 is symmetrical on either side of a central slot 24 which is open at one end. The slotted plate 22 includes a reduced neck portion 26 in alignment with the slot 24. The neck portion 26 is reversely curved and connects the contact portion 22 slightly offset in each of two directions transversely of the major axis of the contact 10. Slotted plate 22 provides a pair of wire gripping jaws 28 on either side of the central slot 24, which jaws are capable of slicing through insulation on a wire or a pair of wires and grippingly engaging the conductor of the wire of a pair of wires to make electrical contact therewith. The slotted plate 22 further includes a pair of spaced flukes 30 adjacent the narrow neck 26.
As shown more particularly in FIG. 2 the housing 2 is provided with recesses 32 into which the tines 20 are latchably received. The housing 2 further includes shoulder portions 34 against which the flukes 30 are supported. Portions of the housing 2 therefore are laterally received between the tines 20 and the flukes 30 of the contacts 10, thereby to position the contacts in the housing. The housing 2 further is provided with integral and outwardly projecting flanges 36 which are shown in FIGS. 1 and 3 arranged in rows on opposite sides of the central axis of the connector block 1. Grooves 38 are provided along the sides of the flanges facing the spaces defined between adjacent flanges. The slotted plates 22 span across the spaces between adjacent flanges, and the side margins of the contacts are received in the grooves which are mutually aligned. The neck portions 26 of the slotted plates together with corresponding central slot portions 24 are aligned with the spaces between the flanges 36. The flanges 36 therefore provide support across the thickness of the contacts preventing buckling of the same during wire insertion. Further the grooves 38 are sufficiently deep to allow for biasing apart the jaws on either side of the slot 24 upon receipt of one or a pair of wires therein. The flanges 36 are integrally joined to corresponding rows of columnar projections 40 integral with and outwardly projecting from the housing portion 2 of the block 1. The spaces between adjacent projections 40 are in alignment with the slots 24 and define wire aligning passageways for initially receiving and guiding a discrete wire for insertion thereof with a corresponding slot 24. The projections 40 are sufficiently thick such that the passageways are relatively lengthy and therefore provide large target areas which are easy to see and to find when the wires are positioned for insertion therein. Additionally the lengthy passageways are parallel with each other tending to arrange inserted wires in orderly parallel rows. The projections 40 further includes mutually aligned projecting ribs 42 projecting into the passageways and aligned in the direction of wire insertion into the passageways. The ribs grip inserted wires on opposite sides thereof serving as a strain relief whereby pull out of the wires from the jaws of the contacts 22 is prevented. In addition the columnar projections 40 are provided with projecting ears 44 facing into the passageways. The ears are in alignment and are progressively tapered to form a progressively narrowed constriction past which wires must be forced when inserted into the passageways. The ears have inverted shoulders 46 which form keepers which captivate the wires in the passageways to prevent dislodging the inserted wires from their orderly arrangement in rows. The sufficiently lengthy passageways allow the slots 24, the ribs 42 and the ears 44 to be in tandem relationship. Accordingly connection of the wire to the contacts 22, strain relief of the wires when gripped by the ribs 42 and retention of the wires by the ears 46 are three functions which are substantially spaced from one another and along a relatively lengthy portion of the wire.
As more particularly shown in FIGS. 2 and 3 interconnecting wires illustrated at 48 have their end portions inserted within the passageways between columnar projections 40. End portions of the wires 48 are terminated in between the wire gripping jaws 28 which have slicing edges thereon on either side of the slot 24 which slice through the insulation on the wires 48 and compressively engage the conductors of the wires 48. The wires 48 further are captivated beneath the inverted shoulders 46 of the ears 44 and are gripped on opposite sides by the ribs 42. Since the contacts 22 are capable of electrical connection to either one or a pair of wires, additional wires 50 are illustrated as spanning transversely across the block. The additional wires 50 are inserted between the wire gripping jaws of the contacts 22. And if a wire 48 is already present in the wire receiving passageway, the wire 50 will impinge against the wire 48 forcing it further into the passageway until it seats against a bottom wall 52 of the passageway. The passageways which are lengthy in a direction transverse to the connector block therefore arrange corresponding lengthy sections of the wires 48 and 50 in orderly rows. The bottom walls 52 of the passageways are generally coplanar defining a first plane of support for the wires 48. Additionally, the inverted shoulders 46 of the ears 44 are coplanar defining a second plane of support for the wires 50 which are impinged against the wires 48. For those slotted contact portions which receive only the wires 48 therein such wires 48 are supported in the second plane of support until insertion of additional wires 50 force the wires 48 to the first plane of support.
As shown more particularly in FIGS. 2 and 3, the ends of the projections 40 are provided with recessed wire aligning channels 54 which are substantially lengthy in directions transverse to the connector block. The channels 54 of one row of projections 40 are in alignment with the wire receiving passageways between the projections 40 of the opposite row. The wires 50 which span transversely across the connector block are inserted into the channels 54. The channels include coplanar bottom walls 56 portions of which are inclined toward the passageways and more particularly toward the second plane of wire support. The bottom walls 56 further are contiguous with end surfaces 58 of the flanges 36 which surfaces 58 also are inclined toward the second plane of wire support. The wires 60 therefore not only span across the connector block but also span from the second plane of wire support to a third elevated plane of wire support defined by the bottom walls 56 of the channels 54. The bottom walls 56 and the inclined end surfaces 58 support lengthy inclined sections of the wires 50 which bridge across the connector block. The projections 40 are provided with additional ears 60 with inverted shoulders 62 serving as keepers to captivate the wires 50 within the channels 54. The ears 60 are similar therefore to the ears 44. The inverted shoulders 62 are spaced from the bottom walls 56 a distance greater than the diameter of one wire 50 but less than the diameter of two wires 50. By contrast the inverted shoulders 46 are spaced above the bottom walls 52 a distance sufficient to accommodate both a wire 48 and a wire 50 in the passageways.
The channels 54 further are substantially lengthy in a direction transverse to the connector block to align corresponding lengthy sections of the wires 50 in orderly rows in a third plane of wire support.
Although preferred embodiments of the present invention has been illustrated and described in detail other embodiments and modifications thereof which would be apparent to one having ordinary skill in the art are intended to be covered by the spirit and scope of the appended claims.
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This invention relates to a card edge connector, multiple numbers of which are arranged in banks and interconnected by discrete wires. The present invention provides a system for lacing wires through passageways and channels, thereby aligning the wires for insertion within slotted plate electrical contacts. One or a pair of wires may be inserted in each contact. Wire gripping strain relief is provided in each of the wire aligning passageways. The passageways and channels position the wire in an orderly arrangement in different planes within the connectors. Wire retention gates prevent removal of the wires from the channels and passageways.
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FIELD OF THE INVENTION
[0001] This invention relates to a method of printing from an inkjet printhead, whilst modulating a peak power requirement for the printhead. It has been developed primarily to reduce the demands on a pagewidth printhead power supply, although other advantages of the methods of printing described herein will be apparent to the person skilled in the art.
CO-PENDING APPLICATIONS
[0002] The following applications have been filed by the Applicant simultaneously with the present application:
KPP001US KPP002US KPP004US KPP005US KPP006US KPP007US KPP008US CAG001US CAG002US CAG003US CAG004US CAG005US RKA001US RKA002US RKA003US RKA004US RKA005US RKA006US RKA007US RKA008US RKA009US RKB001US RKB002US RKB003US RKB004US RKB005US RKB006US RKC001US RKC002US RKC003US RKC004US RKC005US RKC006US RKC007US RKC008US RKC009US RKC010US RRD001US RRD002US RRD003US RRD004US RRD005US RRD006US RRD007US RRD008US RRD009US RRD010US RRD011US RRD012US RRD013US
The disclosures of these co-pending applications are incorporated herein by reference. The above applications have been identified by their filing docket number, which will be substituted with the corresponding application number, once assigned.
CROSS REFERENCES TO RELATED APPLICATIONS
[0003] Various methods, systems and apparatus relating to the present invention are disclosed in the following US patents/patent applications filed by the applicant or assignee of the present invention:
09/517539 6566858 09/112762 6331946 6246970 6442525 09/517384 09/505951 6374354 09/517608 6816968 10/203564 6757832 6334190 6745331 09/517541 10/203559 10/203560 10/636263 10/636283 10/866608 10/902889 10/902833 10/940653 10/942858 10/727181 10/727162 10/727163 10/727245 10/727204 10/727233 10/727280 10/727157 10/727178 10/727210 10/727257 10/727238 10/727251 10/727159 10/727180 10/727179 10/727192 10/727274 10/727164 10/727161 10/727198 10/727158 10/754536 10/754938 10/727227 10/727160 10/934720 11/212702 PEA31US 10/296522 6795215 10/296535 09/575109 6805419 6859289 09/607985 6398332 6394573 6622923 6747760 6921144 10/884881 10/943941 10/949294 11/039866 11/123011 11/123010 11/144769 11/148237 11/248435 11/248426 10/922846 10/922845 10/854521 10/854522 10/854488 10/854487 10/854503 10/854504 10/854509 10/854510 10/854496 10/854497 10/854495 10/854498 10/854511 10/854512 10/854525 10/854526 10/854516 10/854508 10/854507 10/854515 10/854506 10/854505 10/854493 10/854494 10/854489 10/854490 10/854492 10/854491 10/854528 10/854523 10/854527 10/854524 10/854520 10/854514 10/854519 10/854513 10/854499 10/854501 10/854500 10/854502 10/854518 10/854517 10/934628 11/212823 10/728804 10/728952 10/728806 10/728834 10/728790 10/728884 10/728970 10/728784 10/728783 10/728925 6962402 10/728803 10/728780 10/728779 10/773189 10/773204 10/773198 10/773199 6830318 10/773201 10/773191 10/773183 10/773195 10/773196 10/773186 10/773200 10/773185 10/773192 10/773197 10/773203 10/773187 10/773202 10/773188 10/773194 10/773193 10/773184 11/008118 11/060751 11/060805 11/188017 6623101 6406129 6505916 6457809 6550895 6457812 10/296434 6428133 6746105 10/407212 10/407207 10/683064 10/683041 6750901 6476863 6788336 11/097308 11/097309 11/097335 11/097299 11/097310 11/097213 11/210687 11/097212 11/212637 11/246687 11/246718 11/246685 11/246686 11/246703 11/246691 11/246711 11/246690 11/246712 11/246717 11/246709 11/246700 11/246701 11/246702 11/246668 11/246697 11/246698 11/246699 11/246675 11/246674 11/246667 11/246684 11/246672 11/246673 11/246683 11/246682 10/760272 10/760273 10/760187 10/760182 10/760188 10/760218 10/760217 10/760216 10/760233 10/760246 10/760212 10/760243 10/760201 10/760185 10/760253 10/760255 10/760209 10/760208 10/760194 10/760238 10/760234 10/760235 10/760183 10/760189 10/760262 10/760232 10/760231 10/760200 10/760190 10/760191 10/760227 10/760207 10/760181 10/815625 10/815624 10/815628 10/913375 10/913373 10/913374 10/913372 10/913377 10/913378 10/913380 10/913379 10/913376 10/913381 10/986402 11/172816 11/172815 11/172814 11/003786 11/003354 11/003616 11/003418 11/003334 11/003600 11/003404 11/003419 11/003700 11/003601 11/003618 11/003615 11/003337 11/003698 11/003420 11/003682 11/003699 11/071473 11/003463 11/003701 11/003683 11/003614 11/003702 11/003684 11/003619 11/003617 11/246676 11/246677 11/246678 11/246679 11/246680 11/246681 11/246714 11/246713 11/246689 11/246671 10/922842 10/922848 11/246704 11/246710 11/246688 11/246716 11/246715 11/246707 11/246706 11/246705 11/246708 11/246693 11/246692 11/246696 11/246695 11/246694 10/760254 10/760210 10/760202 10/760197 10/760198 10/760249 10/760263 10/760196 10/760247 10/760223 10/760264 10/760244 10/760245 10/760222 10/760248 10/760236 10/760192 10/760203 10/760204 10/760205 10/760206 10/760267 10/760270 10/760259 10/760271 10/760275 10/760274 10/760268 10/760184 10/760195 10/760186 10/760261 10/760258 11/014764 11/014763 11/014748 11/014747 11/014761 11/014760 11/014757 11/014714 11/014713 11/014762 11/014724 11/014723 11/014756 11/014736 11/014759 11/014758 11/014725 11/014739 11/014738 11/014737 11/014726 11/014745 11/014712 11/014715 11/014751 11/014735 11/014734 11/014719 11/014750 11/014749 11/014746 11/014769 11/014729 11/014743 11/014733 11/014754 11/014755 11/014765 11/014766 11/014740 11/014720 11/014753 11/014752 11/014744 11/014741 11/014768 11/014767 11/014718 11/014717 11/014716 11/014732 11/014742 11/097268 11/097185 11/097184 11/124202 11/124163 11/124157 11/124201 11/124167 11/228481 11/228477 11/228485 11/228483 11/228521 11/228517 09/575197 09/575195 09/575159 09/575132 09/575123 09/575148 09/575130 09/575165 09/575153 09/575118 09/575131 09/575116 09/575144 09/575139 09/575186 6681045 6728000 09/575145 09/575192 09/575181 09/575193 09/575156 09/575183 6789194 09/575150 6789191 6644642 6502614 6622999 6669385 6549935 09/575187 6727996 6591884 6439706 6760119 09/575198 6290349 6428155 6785016 09/575174 09/575163 6737591 09/575154 09/575129 09/575124 09/575188 09/575189 09/575162 09/575172 09/575170 09/575171 09/575161
[0004] An application has been listed by its docket number. This will be replaced when the application number is known. The disclosures of these applications and patents are incorporated herein by reference.
BACKGROUND TO THE INVENTION
[0005] Inkjet printers are now commonplace in homes and offices. For example, inkjet photographic printers, which print color images generated on digital cameras, are, to an increasing extent, replacing traditional development of photographic negatives. With the increasing use of inkjet printers, the demands of such printers in terms of print quality and speed, continue to increase.
[0006] All commercially available inkjet printers use a scanning printhead, which traverses across a stationary print medium. After each sweep of the printhead, the print medium incrementally advances ready for the next line(s) of printing. Such printers are inherently slow and are becoming unable to meet the needs of current demands of inkjet printers.
[0007] The present Applicant has previously described many different types of pagewidth printheads, which are fabricated using MEMS technology. In pagewidth printing, the print medium is continuously fed past a stationary printhead, thereby allowing high-speed printing at, for example, one page per 1-2 seconds. Moreover, MEMS fabrication of the printhead allows a much higher nozzle density than traditional scanning printheads, and print resolutions of 1600 dpi are possible.
[0008] Some of the Applicant's MEMS pagewidth printheads are described in the patents and patent applications listed in the cross-references section above, the contents of which are herein incorporated by reference.
[0009] To a large extent, pagewidth printing has been made possible by reducing the total energy required to fire each ink droplet and/or efficiently removing heat from the printhead via ejected ink. In these ways, self-cooling of the printhead can be achieved, which enables a pagewidth printhead having a high nozzle density to operate without overheating.
[0010] However, whilst a total amount of energy to print, say, a full-color photographic page will be approximately constant for any given pagewidth printhead, the power requirement of the printhead may, of course, vary. An average power requirement for printing a page is determined by the total energy required and the total time taken to print the page, assuming an equal distribution of printing over the time period. In addition, the power requirement of the printhead during printing of the page may fluctuate. Due to a particular configuration of the printhead or printer controller, some lines of print may consume more power than other lines of print. Hence, a peak power requirement for each line of printing may be different.
[0011] In a typical pagewidth printhead, nozzles ejecting the same color of ink are arranged longitudinally in color channels along the length of the printhead. Each color channel may comprise one or more rows of nozzles, all ejecting the same colored ink. In a simple example, there may be one cyan row of nozzles, one magenta row of nozzles and one yellow row of nozzles. Usually, each row of nozzles will be fired sequentially during printing e.g. cyan then magenta then yellow.
[0012] Furthermore, a typical pagewidth printhead may be comprised of a plurality of printhead modules, which abut each other and cooperate to form a printhead extending across a width of the page to be printed. Each printhead module is typically a printhead integrated circuit comprising nozzles and drive circuitry for firing the nozzles. The rows of nozzles extend over the plurality of printhead modules, with each printhead module including a respective segment of each nozzle row.
[0013] In previous patent applications, listed below, we described various types of printheads, printer controllers and methods of printing. The contents of these patent applications are herein incorporated by reference:
10/854521 10/854522 10/854488 10/854487 10/854503 10/854504 10/854509 10/854510 10/854496 10/854497 10/854495 10/854498 10/854511 10/854512 10/854525 10/854526 10/854516 10/854508 10/854507 10/854515 10/854506 10/854505 10/854493 10/854494 10/854489 10/854490 10/854492 10/854491 10/854528 10/854523 10/854527 10/854524 10/854520 10/854514 10/854519 10/854513 10/854499 10/854501 10/854500 10/854502 10/854518 10/854517 10/934628 11/212823
[0014] In our previous patent applications U.S. Ser. No. 10/854,498 (Docket No. PLT012US), filed May 27, 2004, U.S. Ser. No. 10/854,516 (Docket No. PLT017US), filed May 27, 2004 and U.S. Ser. No. 10/854508 (Docket No. PLT018US), filed May 27, 2004, we described a method of printing a line of dots where not all nozzles in one row or one segment are fired simultaneously. Rather, the nozzles are fired sequentially in firing groups in order to minimize the peak power requirement during printing of one line. As a consequence, each line of printing is typically not a perfectly straight line (unless the physical arrangements of the nozzles directly compensates for the firing order in which case it can be a straight line), although this imperfection is undetectable to the human eye. Each segment on a printhead module may comprise, for example, 10 firing groups of nozzles, in order to minimize, as far as possible within the print speed requirements, the peak power requirement for firing that segment of the nozzle row.
[0015] In our previous patent applications U.S. Ser. No. 10/854,512 (Docket No. PLT014US), filed May 27, 2004 and U.S. Ser. No. 10/854,491 (Docket No. PLT028US), filed May 27, 2004, we described a means for joining abutting printhead modules such that the effective distance between adjacent nozzles (‘nozzle pitch’) in the row remains constant. At one end of each printhead module, there is a displaced nozzle row portion, which is not aligned with its corresponding nozzle row. The firing of these displaced nozzles is timed so that they effectively print onto the same line as the row to which they correspond. As such, all references to “rows”, “rows of nozzles” or “nozzle rows” herein include nozzle rows comprising one or more displaced row portions, as described in U.S. Ser. No. 10/854,512 (Docket No. PLT014US), filed May 27, 2004 and U.S. Ser. No. 10/854,491 (Docket No. PLT028US), filed May 27, 2004.
[0016] In our previous patent applications U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004, we described a means by which the visual effect of defective nozzles is reduced. The printhead described comprises one or more ‘redundant’ color channels, so that for a first row of nozzles ejecting a given color, there is a corresponding second (‘redundant’) row of nozzles from a different color channel which eject the same color. As described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004, one line may be printed by the first nozzle row and the next line is printed by the second nozzle row so that the first and second nozzle rows print alternate lines on the page. Thus, if there are unknown defective nozzles in a given row, the visual effect on the page is halved, because only every other line is printed using that row of nozzles.
[0017] Alternatively, if there are known dead nozzles in a given row, the corresponding row of nozzles may be used to print dots in those positions where there is a known dead nozzle. In other words, only a small number of nozzles in the ‘redundant’ row may be used to print.
[0018] As already mentioned, the redundancy scheme described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004 has the advantage of reducing the visual impact of dead nozzles, either known or unknown. Moreover, careful choice of redundant colors may be used to further reduce the visual impact of dead nozzles. For example, since yellow makes the lowest contribution (11%) to luminance, the human eye is least sensitive to missing yellow dots and, therefore, yellow would be a poor choice for a redundant color. On the other hand, black, makes a much higher contribution to luminance and would be a good choice for a redundant color.
[0019] However, while the redundancy scheme described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004 can compensate for dead nozzles and reduce (e.g. halve) the number of dots fired by some nozzles, it places increased demands on the power supply which is used to power the printhead. The reason is because in the time it takes for the print medium to advance by one line (one ‘line-time’), each nozzle row must be allotted a portion of the line-time in which to fire, in order to achieve dot-on-dot printing and provide the desired image. Each nozzle row is allotted a portion of the line-time, since not all nozzle rows can fire simultaneously. (If all nozzle rows were to fire simultaneously, there would be an unacceptable current overload of the printhead).
[0020] In a simple CMY pagewidth printhead, having three rows of nozzles and no redundant color channels, each nozzle row must fire in one-third of the line-time. If the average power requirement of the printhead is x, then the peak power requirement over the duration of the line-time is as shown in Table 1:
TABLE 1 Color Peak Power Line-time Channel Requirement 0 C x 0.33 M x 0.67 Y x 0 (new line) C x . . . etc.
[0021] In this simple CMY printhead with no redundant nozzles, power is distributed evenly over the duration of the line-time so that the peak power requirement is constant and equal to the average power requirement of the printhead. From the standpoint of the power supply, this situation is optimal, but, on the other hand, there is no means for minimizing the visual effects of dead nozzles.
[0022] In a CMY printhead having redundant cyan and magenta color channels (i.e. C 1 , C 2 , M 1 , M 2 and Y color channels) and a pair of nozzle rows in each color channel (for even and odd dots), each nozzle row is allotted one-tenth of the line-time, since there are now ten nozzle rows. Now if the average power requirement of the printhead is x, with the redundancy scheme and firing sequence described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004, the peak power requirement over the duration of two line-times is as shown in Table 2:
TABLE 2 Line-time Color Channel Peak Power Requirement 0 C1 (even) 1.67x 0.1 C2 (even) 0 0.2 M1 (even) 1.67x 0.3 M2 (even) 0 0.4 Y (even) 1.67x 0.5 C1 (odd) 1.67x 0.6 C2 (odd) 0 0.7 M1 (odd) 1.67x 0.8 M2 (odd) 0 0.9 Y (odd) 1.67x 0 (new line) C1 (even) 0 0.1 C2 (even) 1.67x 0.2 M1 (even) 0 0.3 M2 (even) 1.67x 0.4 Y (even) 1.67x 0.5 C1 (odd) 0 0.6 C2 (odd) 1.67x 0.7 M1 (odd) 0 0.8 M2 (odd) 1.67x 0.9 Y (odd) 1.67x 0 (new line) C1 (even) 1.67x . . . etc
[0023] It is evident from the above table that the peak power requirement of the printhead fluctuates severely between 1.67x and 0 within the period of a line-time, even though the average power consumed over the whole line-time is still x. In practical terms, it is difficult to manufacture a power supply which is able to deliver severely fluctuating amounts of power within each line-time. Hence, the redundancy described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004is difficult to implement in practice, even though it offers considerable advantages in terms of reducing the visual effects of known dead nozzles.
[0024] Of course, a printhead could be configured not to fire redundant color channels in a given line-time, resulting in an average of x peak power for each nozzle row. Such a configuration is effectively the same as that described in Table 1. While this configuration would address peak power and misdirectionality issues, it would not address the problem of known dead nozzles, since only one of each redundant color channel would be able to be fired in a given line-time, thereby losing one of the major advantages of redundancy.
[0025] It would be desirable to provide a method of printing whereby fluctuations in a peak power requirement are minimized. It would be further desirable to provide a method of printing whereby the average power requirement of the printhead is substantially equal to the peak power requirement at any given time during printing. It would be further desirable to provide a method of printing, whereby, in addition minimizing fluctuating peak power requirements, the visual effects of dead or malfunctioning nozzles are reduced. It would be further desirable to provide a method of printing, whereby, in addition to minimizing fluctuating peak power requirements, the visual effects of misdirected ink droplets is reduced.
SUMMARY OF THE INVENTION
[0026] In a first aspect, there is provided a method of modulating a peak power requirement of an inkjet printhead, said printhead comprising a plurality of first nozzles and a plurality of second nozzles supplied with a same colored ink, said first nozzles and second nozzles being configured in a plurality of sets, wherein each set of nozzles comprises one first nozzle and one corresponding second nozzle, each nozzle in a set being configurable to print a dot of said ink onto a substantially same position on a print medium, said method comprising:
[0027] (a) selecting a firing nozzle from at least one set of nozzles, said selection being on the basis of modulating said peak power requirement; and
[0028] (b) printing dots onto said print medium using said firing nozzle.
[0029] In a second aspect, there is provided a method of printing a line of dots from an inkjet printhead, said printhead comprising a plurality of first nozzles and a plurality of second nozzles supplied with a same colored ink, said first nozzles and second nozzles being configured in a plurality of sets, wherein each set of nozzles comprises one first nozzle and one corresponding second nozzle, each nozzle in a set being configurable to print a dot of said ink onto a substantially same position on a print medium,
[0030] said method comprising printing a line of dots across said print medium such that said first nozzles and said second nozzles each contribute dots to said line.
[0031] In a third aspect, there is provided a method of modulating a peak power requirement of an inkjet printhead, said printhead comprising a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along said printhead, each nozzle in a color channel ejecting the same colored ink, wherein said printhead is comprised of a plurality of printhead modules, each printhead module comprising a respective segment of each nozzle row,
[0032] said method comprising each of said printhead modules firing a respective segment within a predetermined segment-time, wherein at least one of said fired segments is contained in a different color channel from at least one other of said fired segments.
[0033] In a fourth aspect, there is provided an inkjet printhead comprising a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along said printhead, each nozzle in a row ejecting the same colored ink, wherein said printhead is comprised of a plurality of printhead modules, and the number of color channels is equal to the number of printhead modules.
[0034] In a fifth aspect, there is provided a printer controller for supplying dot data to an inkjet printhead, said printhead comprising a plurality of first nozzles and a plurality of second nozzles supplied with a same colored ink, said first nozzles and second nozzles being configured in a plurality of sets, wherein each set of nozzles comprises one first nozzle and one corresponding second nozzle, each nozzle in a set being configurable by said printer controller to print a dot of said ink onto a substantially same position on a print medium, said printer controller being programmed to supply dot data such that said first nozzles and said second nozzles each contribute dots to a line of printing.
[0035] In a sixth aspect, there is provided a printer controller for supplying dot data to a printhead, said printhead comprising a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along said printhead, each nozzle in a color channel ejecting the same colored ink, wherein said printhead is comprised of a plurality of printhead modules, each printhead module comprising a respective segment of each nozzle row, said printer controller being programmed to supply dot data such that each of said printhead modules fires a respective segment within a predetermined segment-time, wherein at least one of said fired segments is contained in a different color channel from at least one other of said fired segments.
[0036] In a seventh aspect of the invention, there is provided a printhead system comprising an inkjet printhead and a printer controller for supplying dot data to said printhead,
[0037] said printhead comprising a plurality of first nozzles and a plurality of second nozzles supplied with a same colored ink, said first nozzles and second nozzles being configured in a plurality of sets, wherein each set of nozzles comprises one first nozzle and one corresponding second nozzle, each nozzle in a set being configurable by said printer controller to print a dot of said ink onto a substantially same position on a print medium,
[0038] said printer controller being programmed to supply dot data such that said first nozzles and said second nozzles each contribute dots to a line of printing.
[0039] In an eighth aspect of the invention, there is provided a printhead system comprising an inkjet printhead and a printer controller for supplying dot data to said printhead,
[0040] said printhead comprising a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along said printhead, each nozzle in a color channel ejecting the same colored ink, wherein said printhead is comprised of a plurality of printhead modules, each printhead module comprising a respective segment of each nozzle row,
[0041] said printer controller being programmed to supply dot data such that each of said printhead modules fires a respective segment within a predetermined segment-time, wherein at least one of said fired segments is contained in a different color channel from at least one other of said fired segments.
[0042] All aspects of the invention provide the advantage of modulating a peak power requirement of the inkjet printhead. The corollary is that a power supply, which supplies power to the printhead, need not be specially adapted to supply severely fluctuating amounts of power throughout each print cycle. In the present invention, the degree of peak power fluctuations within each line-time are substantially reduced. Hence, the design and manufacture of the printhead power supply may be simplified and the power supply is made more robust by virtue of not having to deliver severely fluctuating amounts of power to the printhead.
[0043] In addition to modulating the peak power requirement of the printhead, the present invention allows print quality to be improved by using redundant nozzle rows, and without compromising the above-mentioned improvements in peak power requirement. Print quality may be improved by, for example, reducing the visual effects of unknown dead nozzles in the printhead, and reducing the visual effects of misdirected ink droplets.
[0044] As used herein, the terms “row”, “rows of nozzles”, “nozzle row” etc. may include nozzle rows comprising one or more displaced row portions.
[0045] As used herein, the term “ink” includes any type of ejectable fluid, including, for example, IR inks and fixatives, as well as standard CMYK inks. Likewise, references to “same colored ink” include inks of a same color or type e.g. same cyan ink, same IR ink or same fixative.
[0046] As used herein, the term “substantially the same position on a print medium” is used to mean that a droplet of ink has an intended trajectory to print at a same position on the print medium (as another droplet of ink). However, due to inherent error margins in firing droplets of ink, random misdirects or persistent misdirects, a droplet of ink may not be printed exactly on its intended position on the print medium. Hence, the term “substantially the same position on a print medium” includes misplaced droplets, which are intended to print at the same position, but may not necessarily print at that position.
[0047] In accordance with some forms of the invention, the first nozzles and second nozzles are configured in a plurality of sets, wherein each set of nozzles comprises one first nozzle and one corresponding second nozzle. Further, each nozzle in a set is configurable to print a dot of ink onto a substantially same position on a print medium, so that the nozzles can be used interchangeably.
[0048] Optionally, a set is a pair of nozzles consisting of one first nozzle and one second nozzle. However, a set may alternatively comprise further (e.g. third and fourth) nozzles, with each nozzle in the set being configurable to print a dot of ink onto a substantially same position on a print medium. In other words, the present invention is not limited to two rows of redundant nozzles and may include, for example, three or more rows of redundant nozzles.
[0049] Preferably, the printhead is a stationary pagewidth printhead and the print medium is fed transversely past the printhead. The present invention has been developed primarily for use with such pagewidth printheads.
[0050] Optionally, the printhead comprises a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along the printhead, each nozzle in a color channel ejecting the same colored ink. As described in more detail below, each transversely aligned color channel is allotted a portion of a line-time for firing. In this way, dot-on-dot printing can be achieved, which is optimal for dithering.
[0051] Color channels in the printhead may eject the same or different colored inks. However, all nozzles in the same color channel are typically supplied with and eject the same colored ink. Color channels ejecting the same colored ink are sometimes termed ‘redundant’ color channels. Typically, the printhead comprises at least one redundant color channel so that at least one color channel ejects the same colored ink as at least one other color channel.
[0052] Each color channel may comprise a plurality of nozzle rows. Optionally, each color channel comprises a pair of nozzle rows. Typically, nozzle rows in the same color channel are transversely offset from each other. For example, one nozzle row in a pair may be configured to print even dots on a line, while the other nozzle row in the pair may be configured to print odd dots on the same line. The nozzle rows in a pair are usually spaced apart in a transverse direction to allow convenient timing of nozzle firings. For example, the even and odd nozzle rows in one color channel may be spaced apart by two lines of printing.
[0053] Optionally, each set of nozzles comprises one first nozzle from a first color channel and one second nozzle from a second color channel. The first and second nozzles in the set are aligned transversely so that each can print onto the substantially same position on a print medium.
[0054] Optionally, one set of nozzles prints a column of same-colored dots down a print medium, with each nozzle in the set contributing dots to the column. As used herein, a “column” refers to a line of dots printed substantially perpendicular to the printhead and substantially parallel with a feed direction of the print medium. Optionally, one first nozzle in the set prints about half of the column and one second nozzle in the set prints about half of the column, so that the first and second nozzles in the set share printing of the column equally between them.
[0055] Optionally, a visual effect of misdirected ink droplets is reduced. An advantage of using a plurality (e.g. two) nozzles for printing the same column is that misdirected ink droplets may be averaged out between those nozzles.
[0056] Optionally, when printing a line of same-colored dots across the print medium, the first nozzles and second nozzles contribute dots to the line. As used herein, a “line” refers to a line of dots printed substantially parallel with the printhead and substantially perpendicular to a feed direction of the print medium. Optionally, the first nozzles print about half of the line and the second nozzles print about half of the line, so that the first and second nozzles share printing of the line equally between them. Accordingly, the peak power requirement for printing the line is reduced by about 50%, as compared to printing the line using only first nozzles or only second nozzles. Optionally, alternate first nozzles in a first nozzle row are used to print about half of the line and alternate second nozzles in a second nozzle row are used to print about half of the line. However, other patterns for sharing printing between the first and second nozzles may also be used.
[0057] Optionally, a visual effect of malfunctioning or dead nozzles is reduced. The nozzles may be known dead nozzles or unknown dead nozzles. The visual effect of an unknown dead nozzle is reduced by virtue of the fact that the nozzle is only required to print about half of the time. For example, with an unknown dead magenta nozzle, a column of magenta dots would be missing completely with no redundancy, whereas half of the column is still printed using redundancy. The latter is, of course, far more visually acceptable than the former.
[0058] Optionally, the color (which is the same color printed by the first and second nozzles) is magenta, cyan or black. The human eye is most sensitive to magenta, cyan and black, and these colors are consequently the preferred candidates for redundancy. A printhead may contain more than one redundant color channels. For example, the printhead may comprise first and second magenta nozzles, and first and second cyan nozzles.
[0059] In accordance with some forms of the invention, there is provided a method of out-of-phase printing so as to modulate a peak power requirement of the printhead. Typically, the printhead comprises a plurality of transversely aligned color channels with each color channel comprising at least one nozzle row extending longitiudinally along the printhead. Each nozzle in a color channel is supplied with and ejects the same colored ink. Typically, the printhead is comprised of a plurality of printhead modules, with each module comprising a respect segment of each nozzle row. Out-of-phase printing is provided by a method in which each of the printhead modules fires a respective segment within a predetermined segment-time, wherein at least one of the fired segments is contained in a different color channel from at least one other of the fired segments.
[0060] A segment-time may be defined as a predetermined fraction of one line-time. A line-time is defined as the time taken for the print medium to advance past the printhead by one line. Typically, all segments in a nozzle row are fired within one line-time. Optionally, a segment-time is equal to one line-time divided by the number of nozzle rows. However, a period of each line-time may be dedicated to a line-based overhead, in which case the segment-time will be less than one line-time divided by the number of nozzle rows. Generally, all segment-times are equal.
[0061] Optionally, at least one nozzle row has a different peak power requirement from other nozzle rows. For example, a redundant nozzle row would normally have half the peak power requirement of a non-redundant nozzle row. Optionally, a predetermined firing sequence modulates the peak power requirement during each segment-time so that the peak power requirement is within about 10%, optionally within 5%, of the average power requirement of the printhead. In some embodiments of the invention, the peak power requirement of the printhead is equal to the average power requirement of the printhead.
[0062] Typically, all segments on the printhead are fired within one-line time.
[0063] In some forms of the invention, the number of color channels is equal to the number of printhead modules. This is the optimum number of color channels and modules to achieve perfect out-of-phase firing. However, as will be explained in more detail below, the advantages of out-of-phase firing may still be achieved using any number of printhead modules and color channels.
[0064] Optionally, with equal numbers of modules and color channels, each of the printhead modules fires a segment from a different color channel within the predetermined segment-time. Further, each segment in a nozzle row may be fired sequentially. However, as will be explained in more detail below, each segment in a nozzle row need not be fired sequentially, whilst still enjoying the advantages of out-of-phase firing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] Specific forms of the present invention will be now be described in detail, with reference to the following drawings, in which:
[0066] FIG. 1 is a plan view of a pagewidth printhead according to the invention;
[0067] FIG. 2 is a plan view of a printhead module, which is a part of the printhead shown in FIG. 1 ;
[0068] FIG. 3 is a schematic representation of a portion of each color channel of the printhead shown in FIG. 1 ;
[0069] FIG. 4A shows which even nozzles fire in one line-time using dot-at-a-time redundancy according to the invention;
[0070] FIG. 4B shows which odd nozzles fire in the next line-time from FIG. 4A ; and
[0071] FIG. 5 shows a printhead system according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0072] The invention will be described with reference to a CMY pagewidth inkjet printhead 1 , as shown in FIG. 1 . The printhead 1 has five color channels 2 , 3 , 4 , 5 and 6 , which are C 1 , C 2 , M 1 , M 2 and Y respectively. In other words cyan and magenta have ‘redundant’color channels. The reason for making C and M redundant is that Y only contributes 11% of luminance, while C contributes 30% and M contributes 59%. Since the human eye is least sensitive to yellow, it is more visually acceptable to have missing yellow dots than missing cyan or magenta dots. In this printhead, black (K) printing is achieved via process-black (CMY).
[0073] The printhead 1 is comprised of five abutting printhead modules 7 , which are referred to from left to right as A, B, C, D and E. The five modules 7 cooperate to form the printhead 1 , which extends across the width of a page (not shown) to be printed. In this example, each module 7 has a length of about 20 mm so that the five abutting modules form a 4″ printhead, suitable for pagewidth 4″×6″ color photo printing. During printing, paper is fed transversely past the printhead 1 and FIG. 1 shows this paper direction.
[0074] Each of the five color channels on the printhead 1 comprises a pair of nozzle rows. For example, the C 1 color channel 2 comprises nozzle rows 2 a and 2 b . These nozzle rows 2 a and 2 b extend longitudinally along the whole length of the printhead 1 . Where abutting printhead modules 7 are joined, there is a displaced (or dropped) triangle 8 of nozzle rows. These dropped triangles 8 allow printhead modules 7 to be joined, whilst effectively maintaining a constant nozzle pitch along each row. A timing device (not shown) is used to delay firing nozzles in the dropped triangles 8 , as appropriate. A more detailed explanation of the operation of the dropped triangle 8 is provided in the Applicant's patent applications U.S. Ser. No. 10/854,512 (Docket No. PLT014US), filed May 27, 2004 and U.S. Ser. No. 10/854,491 (Docket No. PLT028US), filed May 27, 2004.
[0075] Each of the printhead modules 7 contains a segment from each of the nozzle rows. For example, printhead module A contains segments 2 a A , 2 b A , 3 a A , 3 b A , 4 a A etc. Segments from the same nozzle row cooperate to form a complete nozzle row. For example, segments 2 a A , 2 a B , 2 a C , 2 a D and 2 a E cooperate to form nozzle row 2 a . FIG. 2 shows the printhead module A with its respect segments from each nozzle row.
[0076] Referring to FIG. 3 , there is shown a detailed schematic view of a portion of the five color channels 2 , 3 , 4 , 5 and 6 . From FIG. 3 , it can be seen that the pair of nozzle rows (e.g. 2 a and 2 b ) in each color channel (e.g. 2 ) are transversely offset from each other. In color channel 2 , for example, nozzle row 2 a prints even dots in a line, while nozzle row 2 b prints interstitial odd dots in a line.
[0077] Furthermore, the even rows of nozzles 2 a , 3 a , 4 a , 5 a and 6 a are transversely aligned, as are the odd rows of nozzles 2 b , 3 b , 4 b , 5 b and 6 b . This transverse alignment of the five color channels allows dot-on-dot printing, which is optimal in terms of dithering. Within a period of one line-time, all even nozzles and all odd nozzles must be fired so that dot-on-dot printing is achieved. The even and odd nozzles (e.g. 2 a and 2 b ) in the same color channel (e.g. 2 ) may be separated by, for example, two lines. Adjacent color channels (e.g. 2 and 3 ) may be separated by, for example, ten lines. However, it will be appreciated that the exact spacing between even/odd nozzle rows and adjacent color channels may be varied, whilst still achieving dot-on-dot printing.
[0000] Dot-at-a-Time Redundancy
[0078] In the printhead 1 described above, there are two cyan (C 1 , C 2 ) and two magenta (M 1 , M 2 ) color channels. In the Applicant's terminology, the C 1 /C 2 and M 1 /M 2 color channels are described as ‘redundant’ color channels.
[0079] As explained above, with five color channels and a pair of nozzle rows in each color channel, each nozzle row must print in one-tenth of the line-time in order to achieve all the advantages of redundancy and compensate for any known dead nozzles using a redundant color channel. The inherent power supply problems in relation to the redundancy scheme described in U.S. Ser. No. 10 / 854 , 507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004 have also been described above.
[0080] Dot-at-a-time redundancy is where redundant rows of nozzles are used such that there is never more than one out of every two adjacent nozzles firing within a single nozzle row. In other words, the even dots for a color are produced by two nozzle rows (each printing half of the even dots), and the odd dots for a color are produced by two nozzle rows (each printing half of the dots). For example, nozzle rows 2 a and 3 a may both contribute even dots to a line of printing, and nozzle rows 2 b and 3 b may both contribute odd dots to a line of printing.
[0081] FIGS. 4A and 4B show a firing sequence for two lines of printing using dot-at-a-time redundancy. The nozzles indicated in FIGS. 4A and 4B are not fired simultaneously; each nozzle row is allotted one-tenth of the line-time in which to fire its nozzles, with even nozzles rows firing sequentially followed by odd nozzle rows firing sequentially.
[0082] Referring to FIG. 4A , in the first line-time alternate nozzles are fired in each nozzle row from the C 1 , C 2 , M 1 and M 2 color channels. Nozzles fired from C 2 and M 2 complement those fired from C 1 and M 1 . For example, alternate even nozzles are fired from nozzle row 2 a and complementary alternate even nozzles are fired from nozzle row 3 a . Nozzle rows 6 a and 6 b in the Y channel have no redundancy and each of these nozzle rows must therefore fire all its nozzles in one-tenth of the line-time.
[0083] Referring to FIG. 4B , in the second line-time the alternate nozzles fired in the first line-time are inversed.
[0084] By using this dot-at-a-time redundancy scheme, print quality is improved by reducing misdirection artifacts (thereby maximizing dot-on-dot placement) and reducing the visual effect of unknown dead nozzles. For example, if half of the dots in a column are from an operational nozzle and half are from a dead nozzle, the visual effect of the dead nozzle will be reduced and the effective print quality is greater than if the entire column came from the dead nozzle. In other words, the present invention achieves at least as good print quality as the line-at-a-time redundancy described in U.S. Ser. No. 10/854,507 (Docket No. PLT019US), filed May 27, 2004 and U.S. Ser. No. 10/854,523 (Docket No. PLT030US), filed May 27, 2004.
[0085] Moreover, the peak power requirements of the printhead are modulated during printing of each line, so that the peak power requirements do not fluctuate as severely as in Table 2. Table 3 shows how the peak power requirement of the printhead (having an average power requirement of x) varies over two lines of printing using dot-at-a-time redundancy according to the present invention:
TABLE 3 Color Nozzle Peak Power Line-time Channel Row Requirement 0 2 (C1) 2a (even) 0.83x 0.1 3 (C2) 3a (even) 0.83x 0.2 4 (M1) 4a (even) 0.83x 0.3 5 (M2) 5a (even) 0.83x 0.4 6 (Y) 6a (even) 1.67x 0.5 2 (C1) 2b (odd) 0.83x 0.6 3 (C2) 3b (odd) 0.83x 0.7 4 (M1) 4b (odd) 0.83x 0.8 5 (M2) 5b (odd) 0.83x 0.9 6 (Y) 6b (odd) 1.67x 0 (new line) 2 (C1) 2a (even) 0.83x 0.1 3 (C2) 3a (even) 0.83x 0.2 4 (M1) 4a (even) 0.83x 0.3 5 (M2) 5a (even) 0.83x 0.4 6 (Y) 6a (even) 1.67x 0.5 2 (C1) 2b (odd) 0.83x 0.6 3 (C2) 3b (odd) 0.83x 0.7 4 (M1) 4b (odd) 0.83x 0.8 5 (M2) 5b (odd) 0.83x 0.9 6 (Y) 6b (odd) 1.67x 0 (new line) 2 (C1) 2a (even) 0.83x . . . etc
[0086] It is evident from Table 3 that the fluctuations in peak power requirement are fewer and less severe compared to line-at-a-time redundancy, described in Table 2. In terms of the design of the printhead power supply, dot-at-a-time redundancy according to the present invention offers significant advantages over line-at-a-time redundancy, whilst maintaining the same improvements in print quality.
[0000] Out-of-Phase Firing
[0087] In all the firing sequences described so far, each color channel is fired in-phase—that is, a whole row of, say, even nozzles from one color channel is fired within its allotted portion of the line-time. In-phase firing provides simpler programming of the printer controller, which controls the firing sequence via dot data sent to the printhead 1 .
[0088] However, according to another form of the present invention, the firing may be out-of-phase—that is, within the same allotted portion of the line-time (termed the ‘segment-time’), at least one segment of nozzles is fired from a color channel that is different from at least one other segment of nozzles. With appropriate sequencing of segment firings, a whole nozzle row can be fired within one line-time, such that the net result is effectively the same as in-phase firing.
[0089] In the case of the printhead 1 , having five color channels and five segments in each nozzle row, it possible to fire segments from all different color channels within one segment time (i.e. one-tenth of a line-time). Segments contained in the same nozzle row are, therefore, fired sequentially during one line-time.
[0090] A major advantage of out-of-phase firing is that if one or more color channels (e.g. Y) has a different peak power requirement to the other color channels, this difference is averaged into the power requirements of the other color channels within each segment-time. Hence, the spike in power (corresponding to the Y channel) in Table 3 is effectively merged into rest of the line-time. The result is that the peak power requirement during each segment-time is always equal to the average power requirement for the printhead. This situation is optimal for supplying power to the printhead.
[0091] Table 4 illustrates a sequence of out-of-phase firing for one line of printing from the printhead 1 , using dot-at-a-time redundancy.
TABLE 4 Line- Module A Module B Module C Module D Module E Peak Power time (CC, S, P) (CC, S, P) (CC, S, P) (CC, S, P) (CC, S, P) Requirement 0 C1, 2a A , 0.83x C2, 3a B , 0.83x M1, 4a C , 0.83x M2, 5a D , 0.83x Y, 6a E , 1.67x x 0.1 C2, 3a A , 0.83x M1, 4a B , 0.83x M2, 5a C , 0.83x Y, 6a D , 1.67x C1, 2a E , 0.83x x 0.2 M1, 4a A , 0.83x M2, 5a B , 0.83x Y, 6a C , 1.67x C1, 2a D , 0.83x C2, 3a E , 0.83x x 0.3 M2, 5a A , 0.83x Y, 6a B , 1.67x C1, 2a C , 0.83x C2, 3a D , 0.83x M1, 4a E , 0.83x x 0.4 Y, 6a A , 1.67x C1, 2a B , 0.83x C2, 3a C , 0.83x M1, 4a D , 0.83x M2, 5a E , 0.83x x 0.5 C1, 2b A , 0.83x C2, 3b B , 0.83x M1, 4b C , 0.83x M2, 5b D , 0.83x Y, 6b E , 1.67x x 0.6 C2, 3b A , 0.83x M1, 4b B , 0.83x M2, 5b C , 0.83x Y, 6b D , 1.67x C1, 2b E , 0.83x x 0.7 M1, 4b A , 0.83x M2, 5b B , 0.83x Y, 6b C , 1.67x C1, 2b D , 0.83x C2, 3b E , 0.83x x 0.8 M2, 5b A , 0.83x Y, 6b B , 1.67x C1, 2b C , 0.83x C2, 3b D , 0.83x M1, 4b E , 0.83x x 0.9 Y, 6b A , 1.67x C1, 2b B , 0.83x C2, 3b C , 0.83x M1, 4b D , 0.83x M2, 5b E , 0.83x x 0 (new line) C1, 2a A , 0.83x C2, 3a B , 0.83x M1, 4a C , 0.83x M2, 5a D , 0.83x Y, 6a E , 1.67x x . . . etc CC = Color Channel; S = Segment; P = Peak Power Requirement
[0092] It should be remembered that, even within one segment, not all nozzles fire simultaneously. The nozzles in one segment are arranged in firing groups, which fire sequentially over the course of their allotted segment-time. However, the important point is that at any given instant, some C 1 , C 2 , M 1 , M 2 and Y nozzles will fire simultaneously, thereby averaging out the higher peak power requirement of the yellow nozzle row.
[0093] In the case of five printhead modules and five color channels, it can be seen that out-of-phase firing works out well. Segments from each color channel can be rotated so that all different segments are fired in one segment-time.
[0094] However, it will be appreciated that out-of-phase firing also works well with any number of printhead modules or color channels. For example, using 20 mm printhead modules 7 , an A4 pagewidth printhead is comprised of eleven abutting modules [(i) to (xi)]. With five color channels and eleven printhead modules, it is impossible to ensure that each printhead module fires a different color channel within a segment-time (i.e. one-tenth of a line-time). Regardless, out-of-phase firing can still be used to optimize the peak power requirement of the printhead.
[0095] For example, the A4 pagewidth printhead may have C, M, Y, K 1 and K 2 color channels. Since there are redundant K channels, these nozzle rows will have a lower peak power requirement than the C, M and Y channels using dot-at-a-time redundancy. Using in-phase firing, there would be appreciable peak power fluctuations during each line-time (C=1.25x, M=1.25x, Y=1.25x, K 1 =0.625x, K 2 =0.625x).
[0096] However, it can be seen from Table 5 that out-of-phase firing accommodates the eleven printhead modules and provides a peak power requirement that is always within 10% of the average power requirement x of the printhead. Indeed, the peak power requirement is always within 5% of the average power requirement x in this example. For the purposes of providing a power supply for the printhead, such small variations in peak power requirement during each line-time are not significant and would not affect the design of the power supply.
TABLE 5 t (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) P 0 C(e) M(e) Y(e) K1(e) K2(e) C(e) M(e) Y(e) K1(e) K2(e) C(e) 1.023x 0.1 M(e) Y(e) K1(e) K2(e) C(e) M(e) Y(e) K1(e) K2(e) C(e) M(e) 1.023x 0.2 Y(e) K1(e) K2(e) C(e) M(e) Y(e) K1(e) K2(e) C(e) M(e) Y(e) 1.023x 0.3 K1(e) K2(e) C(e) M(e) Y(e) K1(e) K2(e) C(e) M(e) Y(e) K1(e) 0.966x 0.4 K2(e) C(e) M(e) Y(e) K1(e) K2(e) C(e) M(e) Y(e) K1(e) K2(e) 0.966x 0.5 C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) 1.023x 0.6 M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) 1.023x 0.7 Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) 1.023x 0.8 K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) 0.966x 0.9 K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) 0.966x 0 C(o) M(o) Y(o) K1(o) K2(o) C(o) M(o) Y(o) K1(o) K2(o) C(o) 1.023x t = line-time; P = Peak Power Requirement (e) = even rows of nozzles; (o) = odd rows of nozzles
[0097] From the foregoing it will be appreciated that the combination of out-of-phase firing together with dot-at-a-time redundancy is optimal for achieving excellent print quality and an acceptable power requirement for the printhead during printing.
[0098] However, these methods of printing may equally be used individually, providing their inherent advantages, or in combination with other methods of printing. For example, out-of-phase firing or dot-at-a-time redundancy may be used in combination with printhead module misplacement correction and/or dead nozzle compensation, as described in our earlier patent applications U.S. Ser. No. 10/854,521 (Docket No. PLT001US) filed May 27, 2004 and U.S. Ser. No. 10/854,515 (Docket No. PLT020US), filed May 27, 2004.
[0000] Printer Controller
[0099] It will also be appreciated by the skilled person that a printer controller 10 , shown schematically in FIG. 5 , may be suitably programmed to provide dot data to the printhead 1 , so as to print in accordance with the methods described above. A printhead system 20 comprises the printer controller 10 and the printhead 1 , which is controlled by the controller. The printer controller 10 communicates dot data to the printhead 1 for printing.
[0100] A suitable type of printer controller, which may be programmed accordingly, was described in our earlier patent application U.S. Ser. No. 10/854521 (Docket No. PLT002US) filed May 27, 2004.
[0101] It will, of course, be appreciated that the present invention has been described purely by way of example and that modifications of detail may be made within the scope of the invention, which is defined by the accompanying claims.
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A method of modulating a peak power requirement of an inkjet printhead is provided. The printhead comprises a plurality of transversely aligned color channels, each color channel comprising at least one nozzle row extending longitudinally along said printhead. Each nozzle in a color channel ejects the same colored ink. The printhead is comprised of a plurality of printhead modules, each printhead module comprising a respective segment of each nozzle row. The method comprising each of the printhead modules firing a respective segment within a predetermined segment-time, wherein at least one of the fired segments is contained in a different color channel from at least one other of the fired segments.
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This is a division of application Ser. No. 398,052, filed July 14, 1982, now U.S. Pat. No. 4,444,765.
BACKGROUND OF THE INVENTION
Petrillo in U.S. Pat. No. 4,168,267 discloses that various phosphinylakanoyl substituted prolines are useful as hypotensive agents due to their ability to inhibit the angiotensin converting enzyme.
Ondetti et al in U.S. Pat. No. 4,151,172 discloses that various phosphonoacyl prolines are useful as hypotensive agents due to their ability to inhibit the angiotensin converting enzyme.
Mercaptoacyl derivatives of proline and substituted prolines are known to be useful hypotensive agents due to their angiotensin converting enzyme inhibition activity. Ondetti et al in U.S. Pat. No. 4,105,776 disclose such compounds wherein the proline ring is unsubstituted or substituted by an alkyl or hydroxy group. Ondetti et al in U.S. Pat. No. 4,154,935 disclose such compounds wherein the proline ring is substituted with one or more halogens. Ondetti et al in U.K. Patent Application No. 2,028,327 disclose such compounds wherein the proline ring is substituted by various ethers and thioethers. Krapcho in U.S. Pat. No. 4,217,359 discloses such compounds wherein the proline ring has a carbamoyloxy substituent. Krapcho in U.K. Patent Application No. 2,039,478 discloses such compounds wherein the proline ring has a diether, dithioether, ketal or thioketal substituent in the 4-position, Krapcho in U.S. Pat. No. 4,316,905 discloses such compounds wherein the proline ring has a cycloakly, phenyl, or phenyl-lower alkylene substituent. Ondetti et al in U.S. Pat. No. 4,234,489 disclose such compounds wherein the proline has a keto substituent in the 5-position. Krapcho et al in U.S. Pat. No. 4,310,461 disclose such compounds wherein the proline has an imido, amido, or amino substituent in the 4-position. Iwao et al in U.K. Patent Application No. 2,027,025 disclose such compounds wherein the proline has an aromatic substituent in the 5-position.
Mercaptoacyl derivatives of 3,4-dehydroproline are disclosed as angiotensin converting enzyme inhibitors by Ondetti in U.S. Pat. No. 4,129,566. Mercaptoacyl derivatives of thiazolidinecarboxylic acid and substituted thiazolidinecarboxylic acid are disclosed as angiotensin converting enzyme inhibitors by Ondetti in U.S. Pat. No. 4,192,878 and by Yoshitomo Pharmaceutical Ind. in Belgian Pat. No. 868,532.
RELATED APPLICATIONS
Petrillo in U.S. application Ser. No. 258,194 discloses amino and substituted amino phosphinylakanoyl compounds which include a methylene function linking an amino function and a phosphinyl function.
SUMMARY OF THE INVENTION
This invention is directed to new amino and substituted amino phosphinylalkanoyl compounds of formula I and salts thereof ##STR2##
R 10 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl.
R 11 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, or hydroxy.
m is zero, one, two or three.
p is one, two or three provided that p is more than one only if R 10 or R 11 is hydrogen, methyl, methoxy, chloro, or fluoro.
R 12 is hydrogen or lower alkyl of 1 to 4 carbons.
Y is oxygen or sulfur.
R 13 is lower alkyl of 1 to 4 carbons, ##STR3## or the R 13 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a lower alkyl of 1 to 4 carbons or a di(lower alkyl of 1 to 4 carbons) substituent.
n is 4 to 8.
n' is 0 or 1.
R 2 is hydrogen, lower alkyl, halo substituted lower alkyl, benzyl or phenethyl.
R 1 and R 6 are independently selected from hydrogen, lower alkyl, benzyl, benzhydryl, or ##STR4## wherein R 14 is hydrogen, lower alkyl, cycloalkyl, or phenyl, and R 15 is hydrogen, lower alkyl, lower alkoxy, phenyl, or R 14 and R 15 taken together are --(CH 2 ) 2 --, --(CH 2 ) 3 --, --CH═CH--, or ##STR5##
R 16 is lower alkyl, benzyl, or phenethyl.
R 17 is hydrogen, lower alkyl, benzyl or phenethyl. ##STR6##
DETAILED DESCRIPTION OF THE INVENTION
This invention in its broadest aspects relates to the amino and substituted amino phosphinylalkanoyl compounds of formula I above, to compositions containing such compounds and to the method of using such compounds as anti-hypertensive agents, and to intermediates useful in preparing such compounds.
The term lower alkyl used in defining various symbols refers to straight or branched chain hydrocarbon radicals having up to ten carbons, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, etc. The preferred lower alkyl groups are up to four carbons with methyl and ethyl most preferred. Similarly the terms lower alkoxy and lower alkylthio refer to such lower alkyl groups attached to an oxygen or sulfur.
The term cycloalkyl refers to saturated rings of 3 to 7 carbon atoms with cyclopentyl and cyclohexyl being most preferred.
The term lower alkenyl refers to straight or branched chain hydrocarbon radicals of 2 to 7 carbons, preferably 2 to 5 carbons, having at least one double bond, for example ethenyl, propenyl, 2-butenyl, etc.
The term halogen refers to chloro, bromo and fluoro.
The term halo substituted lower alkyl refers to such lower alkyl groups described above in which one or more hydrogens have been replaced by chloro, bromo or fluoro groups such as trifluoromethyl, which is preferred, pentafluoroethyl, 2,2,2-trichloroethyl, chloromethyl, bromomethyl, etc. Similarly, the term amino substituted lower alkyl refers to such lower alkyl groups described above in which one or more hydrogens have been replaced by an amino group such as aminomethyl, 1-aminoethyl, 2-aminoethyl, etc.
The symbols ##STR7## represent that the alkylene bridge is attached to an available carbon atom.
The compounds of formula I are prepared according to the following procedures. An acid or its activated form of formula II wherein R 1 is hydrogen, lower alkyl, benzyl, or benzhydryl ##STR8## is reacted with an acid chloride, such as ##STR9## so as to protect the N atom to form a protected acid compound of the formula (III) ##STR10## where Prot represents a protecting group, which is coupled with an imino acid or ester of the formula
HX (IIIA)
to form ##STR11## The term activated form refers to the conversion of the acid to a mixed anhydride, symmetrical anhydride, acid chloride, or activated ester, see Methoden der Organischen Chemie (Houben-Weyl), Vol. XV, part II, page 1 et seq. (1974) for a review of the methods of acylation. Preferably, the reaction is performed in the presence of a coupling agent such as 1,1-carbonyldiimidazole or dicyclohexylcarbodiimide.
Deprotection of the resulting product (IV) for example, by treating with hydrogen gas in the presence of a palladium on carbon catalyst when Prot is benzyloxy carbonyl yields the product (I).
Similarly, the products of formula I wherein either or both of R 1 and R 6 are lower alkyl, benzyl, or benzhydryl can be hydrogenated as described above or chemically treated such as with trifluoroacetic acid and anisole to yield the products of formula I wherein R 1 and R 6 are hydrogen.
The ester products of formula I wherein R 6 is ##STR12## may be obtained by employing the imino acid of formula IIIA in the coupling reaction with the ester group already in place. Such ester starting materials can be prepared by treating the imino acid with an acid chloride such as ##STR13## so as to protect the N-atom. The protected imino acid is then reacted in the presence of base with a compound of the formula ##STR14## wherein L is a leaving group such as chlorine, bromine, tolylsulfonyl, etc., followed by removal of the N-protecting group such as by treatment with acid or hydrogenation.
The ester products of formula I wherein R 6 is ##STR15## can also be obtained by treating the product of formula I wherein R 6 is hydrogen with a molar equivalent of the compound of formula IV. The diester products wherein R 1 and R 6 are the same and are ##STR16## can be obtained by treating the product of formula I wherein R 1 and R 6 are both hydrogen with two or more equivalents of the compound of formula V.
The ester products of formula I wherein R 1 is ##STR17## can be obtained by treating the product of formula I wherein R 1 is hydrogen and R 6 is t-butyl, benzyl or benzhydryl with the compound of formula V in the presence of base. Removal of the R 6 ester group such as by hydrogenation yields the products of formula I wherein R 1 is ##STR18## and R 6 is hydrogen.
The products of formula I wherein R 1 is alkyl or benzyl may be prepared by reacting the product of formula I wherein R 1 is hydrogen with an alkylating agent, such as alkyl halide or benzyl halide in the presence of a base. The products of formula I wherein R 1 is benzhydryl may be obtained by reacting the product of formula I where R 1 is H with diphenyldiazomethane.
The products of formula I wherein R 3 is amino may be obtained by reducing the corresponding products of formula I wherein R 3 is azido.
The products of formula I wherein R 3 is the substituted amino group, ##STR19## may be obtained by treating the corresponding 4-keto product of formula I with the amine, ##STR20## in the presence of hydrogen and catalyst or in the presence of sodium cyanotrihydridoborate.
Compounds of formula II may be prepared by reacting a phthamidoalkyl bromide of the structure ##STR21## with a phosphonous diester of the formula ##STR22## to form the phthamido-diester VIII ##STR23## which is then treated with acid to form the formula II compounds.
The phthamidoalkyl bromide of structure VI is obtained by reacting phthalic anhydride with an aminoalkanol of the structure
H.sub.2 N(CH.sub.2).sub.n --OH VIIIA
followed by treatment with PBr 3 .
The phosphonous diester VII is prepared by reacting methyltributylstannylacetate, a chlorodialkyl phosphite and a free radical initiator, such as azobisisobutyronitrile (AIBN) in the presence of an aromatic solvent such as benzene.
The various imino acids and esters of formula IV are described in the literature and in the various patents and pending U.S. applications referred to above. Various substituted prolines are disclosed by Mauger et al., Chem. Review, Vol. 66, p. 47-86 (1966). When the imino acid is known, it can be readily converted to the ester by conventional means. For example, the esters where R 6 is t-butyl can be obtained by treating the corresponding N-carbobenzyloxyimino acid with isobutylene under acidic conditions and then removing the N-carbobenzyloxy protecting group by catalytic hydrogenation and the esters wherein R 6 is benzyl can be obtained by treating the imino acid with benzyl alcohol and thionyl chloride.
As disclosed by Krapcho in U.S. Ser. No. 164,985, the substituted prolines wherein R 3 is ##STR24## or --(CH 2 ) m --cycloalkyl are prepared by reacting a 4-keto proline of the formula ##STR25## with a solution of the Grignard or lithium reagent
R.sub.3 -Mg-halo or R.sub.3 -Li (X)
wherein R 3 is as defined above and halo is Br or Cl to yield ##STR26## This compound is treated with a dehydrating agent such as p-toluenesulfonic acid, sulfuric acid, potassium bisulfate, or trifluoroacetic acid to yield the 3,4-dehydro-4-substituted proline of the formula ##STR27## Removal of the N-benzyloxycarbonyl protecting group and hydrogenation of the compound of formula XII yields the desired starting materials. The substituted proline wherein R 3 is cyclohexyl can be prepared by furter hydrogenation of the 4-phenyl proline compound.
Preferred compounds of this invention with respect to the imino acid or ester part of the structure of formula I are those wherein:
R 18 is hydrogen, methyl, phenyl, cyclopentyl, cyclohexyl or benzyl.
R 19 is hydrogen, lower alkyl of 1 to 4 carbons, ##STR28##
R 6 is hydrogen or ##STR29## wherein
R 14 is hydrogen, methyl or cycloalkyl, such as cyclohexyl, and R 15 is straight or branched chain lower alkyl of 1 to 4 carbons or phenyl.
R 3 is amino.
R 3 is hydrogen.
R 3 is hydroxy.
R 3 is chloro or fluoro.
R 3 is lower alkyl of 1 to 4 carbons or cyclohexyl.
R 3 is --O--lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons.
R 3 is ##STR30## wherein m is zero, one or two, and R 10 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 3 is ##STR31## wherein m is zero, one or two, and R 10 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 3 is --S--lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons.
R 3 is ##STR32## wherein m is zero, one or two, and R 10 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 4 is --O--lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons.
R 4 is ##STR33## wherein m is zero, one or two, and R 10 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 4 is --S--lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons.
R 4 is ##STR34## wherein m is zero, one or two, and R 10 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 5 is phenyl, 2-hydroxyphenyl, or 4-hydroxyphenyl.
Both R 7 groups are independently selected from fluoro or chloro.
Both R 7 groups are --Y--R 13 wherein Y is O or S, R 13 is straight or branched chain alkyl of 1 to 4 carbons or the R 13 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a methyl or dimethyl substituent.
R 8 , R 8 ', R 9 and R 9 ' are all hydrogen, or R 8 is phenyl, 2-hydroxyphenyl or 4-hydroxyphenyl and R 8 ', and R 9 and R 9 ' are hydrogen.
Most preferred compounds of this invention with respect to the imino acid or ester part of the structure of formula I are those wherein:
X is ##STR35##
R 6 is hydrogen or ##STR36##
R 3 is hydrogen.
R 3 is cyclohexyl.
R 3 is lower alkoxy of 1 to 4 carbons.
R 3 is ##STR37## wherein m is zero, one, or two and R 10 is hydrogen, methyl, methoxy, methylthio, Cl, Br, F or hydroxy.
Y is oxygen or sulfur and r is two or three, especially wherein Y is sulfur and r is two.
Preferred compounds of this invention with respect to the phosphinylalkanoyl sidechain of the structure of formula I are those wherein:
R 1 is hydrogen or ##STR38## wherein R 14 is hydrogen or methyl and R 15 is straight or branched chain lower alkyl of 1 to 4 carbons or phenyl, especially hydrogen or ##STR39##
R 2 is hydrogen.
n is 4 to 7.
n' is zero.
The compounds of this invention wherein at least one of R 1 or R 6 is hydrogen, form basic salts with various inorganic or organic bases which are also within the scope of the invention. Such salts include ammonium salts, alkali metal salts like lithium, sodium and potassium salts (which are preferred), alkaline earth metal salts like the calcium and magnesium salts, salts with organic bases, e.g., dicyclohexylamine salt, benzathine, N-methyl-D-glucamine, hydrabamine salts, salts with amino acids like arginine, lysine and the like. The nontoxic, physiologically acceptable salts are preferred, although other salts are also useful, e.g., in isolating or purifying the product. The salts are formed using conventional techniques.
As shown above, the imino acid or ester portion of the molecule of the products of formula I is in the L-configuration. Depending upon the definition of R 2 , one asymmetric center may be present in the phosphinylalkanoyl sidechain. Thus, some of the compounds can accordingly exist in diastereoisomeric forms or in mixtures thereof. The above-described processes can utilize racemates, enantiomers or diastereomers as starting materials. When diastereomeric products are prepared, they can be separated by conventional chromatographic or fractional crystallization methods.
The products of formula I wherein the imino acid ring is monosubstituted give rise to cis-trans isomerism. The configuration of the final product will depend upon the configuration of the R 3 , R 4 and R 5 substituent in the starting material of formula IIIA.
The compounds of formula I, and the physiologically acceptable salts thereof, are hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II and, therefore, are useful in reducing or relieving angiotensin related hypertension. The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood pressure, produces angiotensin I. Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causative agent in several forms of hypertension in various mammalian species, e.g., humans. The compounds of this invention intervene in the angiotensinogen→(renin)→angiotensin I→angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II. Thus, by the administration of a composition containing one (or a combination) of the compounds of this invention, angiotensin dependent hypertension in a species of mammal (e.g., humans) suffering therefrom is alleviated. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to 100 mg per kilogram of body weight per day, preferably about 1 to 15 mg per kilogram of body weight per day is appropriate to reduce blood pressure. The substance is preferably administered orally, but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this invention can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effective amount which comprises a total daily dosage of about 30 to 600 mg, preferably about 30 to 330 mg of a compound of this invention, and about 15 to 300 mg, preferably about 15 to 200 mg of the diuretic, to a mammalian species in need thereof. Exemplary of the diuretics contemplated for use in combination with a compound of this invention are the thiazide diuretics, e.g., chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methyclothiazide, trichlormethiazide, polythiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spironolactone and salts of such compounds.
The compounds of formula I can be formulated for use in the reduction of blood pressure in compositions such as tablets, capsules or elixirs for oral administration, or in sterile solutions or suspensions for parenteral administration. About 10 to 500 mg of a compound of formula I is compounded with physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
The following examples are illustrative and represent preferred embodiments of the invention. Temperatures are given in degrees centigrade. AG-50W-X8 refers to a crosslinked polystyrenedivinylbenzene sulfonic acid cation exchange resin. HP-20 refers to a porous crosslinked polystyrene-divinylbenzene polymer resin.
EXAMPLE 1
1-[[[(6-Aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt
A. 6-Phthalimido-1-bromohexane
Ref. Can. J. Chem., 1060, (1953)
A mixture of crystalline 6-aminohexanol (11.7 g, 0.1 mole) and phthalic anhydride (14.8 g, 0.1 mole) was heated to 170° C. for 1.5 hours in an argon atmosphere. The evolved H 2 O was then removed with heat and argon flow. The reaction mixture was cooled to 100° C. and PBr 3 (7.2 ml, 0.086 mole) was added in portions (via gas tight syringe) to the reaction mixture. A vigorous reaction occured with each addition. After addition was complete the reaction mixture was heated at 100° C. for an additional 30 minutes. The cooled reaction mixture was diluted with ethanol (20 ml) then poured over H 2 O/ice and refrigerated overnight. A yellow solid was filtered and washed several times with cold H 2 O until the filtrate was slightly acidic. The crude solid was recrystallized from ethanol to give the title compound (21.0 g, 67.7 mmole, 68% yield) as a pale yellow solid, m.p. 54°-55° C. TLC (1:1 hexane/EtOAc) major spot R f =0.8.
Analysis calcd for C 14 H 16 NO 2 Br: C, 54.21; N, 4.51; H, 5.20; Br, 25.76. Found: C, 54.31; N, 4.58; H, 5.24; Br, 25.59.
B. Carbomethoxymethyldichlorophosphine
A mixture of methyltributylstannylacetate (87.0 g, 0.27 mole), chlorodiethylphosphite (34.1 ml, 0.27 mole), azobisisobutyronitrile (AIBN) (250 mg) and benzene (90 ml) was refluxed under argon for 4 hours. The benzene was distilled off at atmospheric pressure in an argon atmosphere. The resulting liquid was distilled in vacuo to obtain the title compound (18.1 g, 93.2 mmole, 39% yield) as a clear liquid, b.p. 112° C. (20 mmHg).
C. Methyl[[(6-phthalimidohexyl)ethoxy]phosphinyl]acetate
A mixture of the bromide from Part A (2.0 g, 6.45 mmole) and phosphonous diester from Part B (2.5 g, 12.9 mmole) was heated under argon for 3 hours. The volatiles were removed in vacuo (0.5 mmHg) and the orange residue (4.0 g) was chromatographed on silica (120 g) eluting with EtOAc to give the title compound (1.9 g, 4.8 mmole, 74% yield) as an oil. TLC (EtOAc) major spot R f =0.3.
D. [[(6-Aminohexyl)hydroxy]phosphinyl]acetic acid
The phthamido-diester from Part C (1.90 g, 4.8 mmole) was treated with HOAc/HCl/H 2 O (6 ml/6 ml/3 ml) then refluxed under argon for 20 hours. The volatiles were removed in vacuo (rotovap). The residue was taken up in water and extracted with ether. The aqueous phase was passed through an AG50WX8 (H + ) (60 ml) column; first washing with H 2 O and then 10% pyridine/H 2 O to elute the compound. The desired fractions were combined and evaporated to give the title compound (0.80 g, 3.4 mmole, 71% yield) as a white solid.
Electrophoresis: pH 6.5, 2000 V, 45 minutes, major spot +3.8 cm, visualized with carboxyl reagent +Δ, trace impurity-1.0 cm, visualized with ninhydrin+Δ, m.p. 236°-238° C.
Analysis Calcd for C 8 H 18 NO 4 P: C, 43.05; H, 8.13; N, 6.27; P, 13.87. Found: C, 42.69; H, 8.41; N, 6.41; P, 13.8.
E. [[6-Benzyloxycarbonylaminohexyl)hydroxy]phosphinyl]acetic acid
A suspension of the amino diacid from Part D (0.75 g, 3.4 mmole) in dry CH 3 CN (7 ml) in an argon atmosphere at 25° C. was treated with bis-trimethylsilyltrifluoroacetamide (3.5 g, 13.6 mmole). A slight exotherm occured and after 20 minutes the mixture became homogeneous. After an additional 40 minutes, benzyl chloroformate (0.9 g, 5.1 mmole) was added in portions. After 16 hours, the reaction mixture was quenched with H 2 O (3 ml). The mixture was taken into saturated NaHCO 3 , washed with ether (2×), and acidified with concentrated HCl. The resulting oil was extracted into EtOAc (2×), washed with brine, dried (MgSO 4 ), and evaporated to obtain a white solid (1.1 g). The crude solid was recrystallized from EtOAc (2×) to give the title compound (0.85 g, 2.4 mmole, 71% yield) as a white solid.
TLC (7/2/1 isopropanol/conc. NH 4 OH/H 2 O) single spot R f =0.5, m.p. 95°-96° C.
Analysis Calcd for C 16 H 24 NO 6 P: C, 53.78; H, 6.77; N, 3.92; P, 8.7. Found: C, 53.86; H, 6.80; N, 3.77; P, 8.3.
F. 1-[[[(6-Benzyloxycarbonylaminohexy)hydroxy]phosphinyl]acetyl]-L-proline, benzyl ester
A mixture of the protected amino diacid from Part E (780 mg, 2.18 mmole), THF (5 ml), and 1,1-carbonyldiimidazole (350 mg, 2.18 mmole) was stirred at 0° C. for 45 minutes under argon. The reaction mixture was then treated with NEt 3 (0.6 ml, 4.4 mmole) and L-proline, benzyl ester, hydrochloride (630 mg, 2.6 mmole), the ice-bath removed, and the resulting solution stirred for 16 hours. The reaction mixture was diluted with EtOAc then washed with 5% KHSO 4 , 5% Na 2 HPO 4 (2×), brine, dried (MgSO 4 ) and evaporated. The residue (1.1 g) was chromatographed on silica (90 g) eluting with CH 2 Cl 2 /CH 3 OH/HOAc (100/5/5). After evaporation and azeotropic removal of HOAc with toluene, and title compound (1.0 g, 1.84 mmole, 84% yield) was obtained as colorless glass.
TLC: (isopropanol/conc. NH 4 OH/H 2 O 7:2:1) single spot R f =0.7.
G. 1-[[[(6-Aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt
A mixture of the benzyl ester from Part F (1.0 g, 1.84 mmole), CH 3 OH (70 ml), and 10% Pd/C (1.1 g) was hydrogenated on the Parr apparatus at 50 psi for 3 hours. The catalyst was removed by filtration through a Celite bed and the CH 3 OH stripped. The crude oil (0.50 g) was taken up in H 2 O and applied to an AG50WX8 (H + ) (10 ml) column eluting first with H 2 O then with 10% pyridine/H 2 O. The desired fractions were combined, the solvent stripped, and the residual pyridine azeotropically removed with toluene. The residue was taken up in H 2 O, filtered (millipore), and lyophilized to give a glassy solid (350 mg). The solid was passed through an AG50WX8(Li + ) (10 ml) column eluting with H 2 O. The desired fractions were combined, taken to small volume, and chromatographed on an HP-20 (200 ml) column eluting with a linear gradient H 2 O/CH 3 CN (0→90%). The desired fractions were combined, stripped to dryness, taken into H 2 O, filtered (millipore), and lyophilized to give the title product (90 mg, 0.28 mmole, 15% yield) as a glassy solid.
TLC: (7:2:1 isopropanol/conc. NH 4 OH/H 2 O) single spot R f =0.3.
Analysis calcd for C 13 H 23 N 2 O 5 PLi.1.3 moles H 2 O: C,43.91; H, 7.25; N, 7.88; P, 8.7. Found: C, 43.93; H, 7.25; N, 7.88; P, 8.7.
EXAMPLE 2-84
Following the procedure of Example 1 but substituting for 6-aminohexanol, the aminoalkanol shown in Col. I, and substituting the phosphonous diester shown in Col. II and the imino acid shown in Col. III, one obtains the product shown in Col. IV. Hydrogenation of the product of Col. IV in examples where R 6 =benzyl or treatment of the product with acid in examples were R 6 =t-butyl yields the corresponding acid product (R 6 is H). Passage of the acid through an Li column yields the corresponding dilithium salt. In examples 58-63, the R 6 group is not removed.
Reaction of the product of Col. IV with an alkylating agent, such as alkyl halide, benzyl halide or acryloxyalkyl halide yields the corresponding product wherein R 1 is alkyl, benzyl or acyloxyalkyl, respectively. Reaction of the product of Col. IV with diphenyldiazomethane yields the product wherein R 1 is benzhydryl.
______________________________________Col. I Col. IIH.sub.2 N(CH.sub.2).sub.nOH ##STR40##Col. III Col. IVHX ##STR41##______________________________________
______________________________________Ex. n n' R.sub.2 X______________________________________2. 4 1 H ##STR42##3. 5 0 CH.sub.3 ##STR43##4. 4 0 CH.sub.2 CCl.sub.3 ##STR44##5. 5 0 ##STR45## ##STR46##6. 6 1 H ##STR47##7. 6 0 H ##STR48##8. 5 0 H ##STR49##9. 4 0 CH.sub.3 ##STR50##10. 5 1 H ##STR51##11. 6 0 H ##STR52##12. 5 0 H ##STR53##13. 6 0 H ##STR54##14. 7 0 H ##STR55##15. 4 0 H ##STR56##16. 5 1 H ##STR57##17. 6 0 H ##STR58##18. 6 1 H ##STR59##19. 5 0 CH.sub.3 ##STR60##20. 4 0 H ##STR61##21. 6 0 H ##STR62##22. 6 0 H ##STR63##23. 6 1 H ##STR64##24. 4 0 CH.sub.3 ##STR65##25. 5 0 H ##STR66##26. 6 0 H ##STR67##27. 8 0 H ##STR68##28. 5 1 CH.sub.3 ##STR69##29. 6 0 H ##STR70##30. 6 0 H ##STR71##31. 5 0 H ##STR72##32. 6 0 H ##STR73##33. 5 0 H ##STR74##34. 6 0 H ##STR75##35. 7 0 H ##STR76##36. 5 0 CH.sub.3 ##STR77##37. 5 0 H ##STR78##38. 8 0 H ##STR79##39. 7 1 H ##STR80##40. 6 0 H ##STR81##41. 5 0 H ##STR82##42. 6 0 H ##STR83##43. 6 0 H ##STR84##44. 6 1 H ##STR85##45. 5 0 CH.sub.3 ##STR86##46. 5 0 H ##STR87##47. 6 1 H ##STR88##48. 6 0 CH.sub.3 ##STR89##49. 5 0 H ##STR90##50. 5 0 H ##STR91##51. 6 0 H ##STR92##52. 5 0 H ##STR93##53. 5 0 H ##STR94##54. 4 0 H ##STR95##55. 6 0 H ##STR96##56. 5 0 H ##STR97##57. 8 0 H ##STR98##58. 4 0 H ##STR99##59. 6 0 H ##STR100##60. 8 0 CH.sub.3 ##STR101##61. 6 0 H ##STR102##62. 5 1 H ##STR103##63. 6 0 H ##STR104##64. 6 0 CH.sub.3 ##STR105##65. 8 1 CH.sub.3 ##STR106##66. 5 0 CH.sub.3 ##STR107##67. 4 1 CH.sub.3 ##STR108##68. 4 0 CH.sub.3 ##STR109##69. 4 1 H ##STR110##70. 6 0 CH.sub.3 ##STR111##71. 7 1 CH.sub.3 ##STR112##72. 5 0 CH.sub.3 ##STR113##73. 6 1 CH.sub.3 ##STR114##74. 7 0 CH.sub.3 ##STR115##75. 8 1 CH.sub.3 ##STR116##76. 4 0 CH.sub.3 ##STR117##77. 5 1 CH.sub.3 ##STR118##78. 6 0 CH.sub.3 ##STR119##79. 7 1 CH.sub.3 ##STR120##80. 8 0 CH.sub.3 ##STR121##81. 8 0 H ##STR122##82. 6 1 CH.sub.3 ##STR123##83. 4 1 C.sub.2 H.sub.5 ##STR124##84. 5 0 H ##STR125##______________________________________
Reduction of the product of Example 8 yields the corresponding 4-amino product. Similarly, the 4-keto product of Example 7 can be reacted to yield various 4-substituted amino products.
EXAMPLE 85
1000 Tablets each containing the following ingredients:
______________________________________1-[[[1-(6-Aminohexyl)hydroxy]- 100 mgphosphinyl]acetyl]-L-proline,dilithium saltCorn starch 50 mgGelatin 7.5 mgAvicel (microcrystalline 25 mgcellulose)Magnesium stearate 2.5 mg 185 mg______________________________________
are prepared from sufficient bulk quantities by mixing the 1-[[[1-(6-aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt and corn starch with an aqueous solution of the gelatin. The mixture is dried and ground to a fine powder. The Avicel and then the magnesium stearate are admixed with granulation. This mixture is then compressed in a tablet to form 1000 tablets each containing 100 mg of active ingredient.
In a similar manner, tablets containing 100 mg of the product of any of Examples 2 to 84 can be prepared.
EXAMPLE 86
1000 Tablets each containing the following ingredients:
______________________________________1-[[[1-(6-Aminohexyl)hydroxy]- 50 mgphosphinyl]acetyl]-L-proline,dilithium saltLactose 25 mgAvicel 38 mgCorn starch 15 mgMagnesium stearate 2 mg 130 mg______________________________________
are prepared from sufficient bulk quantities by mixing the 1-[[[1-(6-aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt, lactose, and Avicel and then blending with the corn starch. Magnesium stearate is added and the dry mixture is compressed in a tablet press to form 1000 tablets each containing 50 mg of active ingredient. The tablets are coated with a solution of Methocel E 15 (methyl cellulose) including as a color a lake containing yellow #6.
In a similar manner, tablets containing 50 mg of the product of any of Examples 2 to 84 can be prepared.
EXAMPLE 87
Two piece #1 gelatin capsules each containing 100 mg of 1-[[[1-(6 -aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt are filled with a mixture of the following ingredients:
______________________________________1-[[[1-(6-aminohexyl)hydroxy]- 100 mgphosphinyl]acetyl]-L-proline,dilithium saltMagnesium stearate 7 mgLactose 193 mg______________________________________
In a similar manner, capsules containing 100 mg of the product of any of Examples 2 to 84 can be prepared.
EXAMPLE 88
An injectable solution is prepared as follows:
______________________________________1-[[[1-(6-Aminohexyl)hydroxy]- 500 gphosphinyl]acetyl]-L-proline,dilithium saltMethyl paraben 5 gPropyl paraben 1 gSodium chloride 25 gWater for injection 5 l.______________________________________
The active substance, preservatives, and sodium chloride are dissolved in 3 liters of water for injection and then the volume is brought up to 5 liters. The solution is filtered through a sterile filter and asceptically filled into presterilized vials which are closed with presterilized rubber closures. Each vial contains 5 ml of solution in a concentration of 100 mg of active ingredient per ml of solution for injection.
In a similar manner, an injectable solution containing 100 mg of active ingredient per ml of solution can be prepared for the product of any of Examples 2 to 84.
EXAMPLE 89
1000 Tablets each containing the following ingredients:
______________________________________1-[[[1-(6-Aminohexyl)hydroxy]- 100 mgphosphinyl]acetyl]-L-proline,dilithium saltAvicel 100 mgHydrochlorothiazide 12.5 mgLactose 113 mgCorn starch 17.5 mgStearic acid 7 mg 350 mg______________________________________
are prepared from sufficient bulk quantities by slugging the 1-[[[1-(6-aminohexyl)hydroxy]phosphinyl]acetyl]-L-proline, dilithium salt, Avicel and a portion of the stearic acid. The slugs are ground and passed through a #2 screen, then mixed with the hydrochlorothiazide, lactose, corn starch, and remainder of the stearic acid. The mixture is compressed into 350 mg capsule shaped tablets in a tablet press. The tablets are scored for dividing in half.
In a similar manner, tablets can be prepared containing 100 mg of the product of any of Example 2 to 84.
EXAMPLE 90
1-[[[(6-Benzyloxycarbonylaminohexyl)-(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]acetyl]-L-proline
A. 1-[[[(6-Benzyloxycarbonylaminohexyl)-(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]acetyl]-L-proline, benzyl ester
A solution of the benzyl ester from Example 1, Part F (0.64 g, 1.5 mmole), triethylamine (0.42 ml, 3.0 mmole) and chloromethyl pivalate (0.45 g, 3.0 mmole) in dry dimethylformamide (5 ml) is stirred at room temperature under argon for 16 hours. The mixture is then partitioned between EtOAc-water. The organic phase is washed successively with 5% KHSO 4 , saturated NaHCO 3 and saturated NaCl, dried over Na 2 SO 4 and evaporated. The crude product is purified by flash chromatography on silica gel to give the title A compound.
B. 1-[[[(6-Aminohexyl)-(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]acetyl]-L-proline
A mixture of the ester from Part A (1.0 g, 1.84 mmole), CH 3 OH (50 ml), and 10% Pd/C (0.5 g) is hydrogenated on the Parr apparatus at 50 psi for 3 hours. The catalyst is removed by filtration through a Celite bed and the CH 3 OH stripped. The crude product is purified by chromatography on HP-20 eluting with a gradient of water-acetonitrile (0→90% CH 3 CN). The fractions containing the desired material are combined, evaporated, taken up in water and lyophilized to give the title compound.
EXAMPLES 91-95
Following the procedure of Example 90 but employing the alkylating agent shown in Col. I in place of the chloromethyl pivalate, one obtains the product in Col. II.
______________________________________Ex. Col. I Col. II______________________________________ ##STR126## 1-[[Acetoxymethoxy-(6- aminohexyl)phosphinyl]- acetyl]-L-proline ##STR127## 1-[[6-Aminohexyl-1- [(ethoxycarbonyloxy)- ethoxy]pho sphinyl]acetyl]- L-proline ##STR128## 1-[[6-Aminohexyl-1-(7- oxo-isobenzofuranyloxy)- phosphinyl]acetyl]-L- proline ##STR129## 1-[[6-Aminohexyl-(benzoyl- oxymethoxy)phosphinyl]- acetyl]-L-proline ##STR130## 1-[[[6-Aminohexyl-[2- methyl-1-(1-oxopropoxy)]- propoxy]phosphinyl]acetyl]- L-proline______________________________________
Similarly, the alkylating agents of Examples 90-95 can be employed with the appropriately protected compounds of Examples 1 to 89 to yield other compounds within the scope of this invention. In the cases where the proline carboxyl group is protected as its phenylmethyl ester rather than its t-butyl ester, it is removed by hydrogenation in the presence of Pd/C in the final step.
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Compounds of the formula ##STR1## wherein X is an amino acid or ester are useful hypotensive agents due to their angiotensin converting enzyme inhibition activity.
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TECHNICAL FIELD
The present invention relates generally to a control system for an internal combustion of an automotive vehicle, and more particularly, to a method and apparatus for predicting the exhaust gas temperature at a predetermined location of the exhaust system.
BACKGROUND
Minimizing tailpipe emission is an objective of closed loop fuel systems. Closed loop fuel systems include a catalytic converter that is used to treat the exhaust gas of an engine. Such converters operate to chemically alter the gas composition produced by the engine to help meet various environmental regulations governing tailpipe emissions. Determining the temperature of the catalytic converter is one feedback used in the control thereof.
The engine has an exhaust manifold that receives exhaust gases from the engine cylinders. The exhaust manifold routes the flow of exhaust gases into the exhaust system that includes the catalytic converter. The exhaust flange is the location where the exhaust manifold and exhaust system are joined. As is described in U.S. Pat. No. 5,956,941, which is incorporated by reference herein, the instantaneous temperature of the catalytic converter may be determined from the instantaneous temperature of the exhaust gas at the exhaust flange. The temperature of the catalyst is then provided to the engine controller to control the various engine operating parameters. It should also be noted that the flange temperature is also used to predict various other downstream predictions such as the front heated exhaust gas oxygen temperature, the catalyst inlet temperature, the catalyst midbed temperature, and the downstream heated exhaust gas oxygen sensor temperature.
It has been found that the exhaust flange temperature response exhibits second order behavior. That is, initially the measured temperature reacts at a fast rate with a zero to 20 second time constant and after that time, the rate slows considerably to a 50 to 250 second time constant. Known methods for determining the exhaust flange temperature do not take this into account and therefore may not be accurate at least over a portion of the temperature range.
Current catalyst temperature prediction algorithms are performed on an engine dynamometer with recalibration after the engine is placed into a vehicle during on road testing. Because the temperature determination may not be accurate as mentioned above, it has been found that about twenty percent of the dynamometer calibrations must be revised in on-road testing. This recalibration increases the cost and time of development.
It would therefore be desirable to provide a method and apparatus for more accurately determining the exhaust flange temperature.
SUMMARY OF THE INVENTION
The present invention provides a more accurate method and apparatus for determining the exhaust flange temperature over the operating range of the automotive vehicle.
In one aspect of the invention, a system for predicting the temperature of a catalyst including a control system and method for controlling an engine of an automotive vehicle having a catalyst and controller is set forth herein. The controller is configured to determine a first exhaust flow rate and a second exhaust flow rate based on a flow rate of the exhaust gases. The controller is further configured to determine a first temperature of exhaust gases associated with the first exhaust flow rate based on a steady state temperature and an amount of heat transferred from the exhaust gases associated with the first exhaust flow rate to an exhaust system. The controller is further configured to determine a second temperature of exhaust gases associated with the second exhaust flow rate based on the steady state temperature. The controller is further configured to determine the catalytic converter temperature based on the first temperature and the second temperature.
In a further aspect of the invention, a method for determining a temperature of an emission catalyst communicating with exhaust gases from an engine includes determining a first exhaust flow rate and a second exhaust flow rate based on a total flow of the exhaust gases, determining a first temperature of exhaust gases associated with the first exhaust flow rate based on a steady state temperature and an amount of heat transferred from the exhaust gases associated with the first exhaust flow rate to an exhaust system, determining a second temperature of exhaust gases associated with the second exhaust flow rate based on the steady state temperature, and determining the catalyst temperature based on the first temperature and the second temperature.
One advantage of the invention is that development time and cost of the engine is reduced because post-dynamometer calibration of the flange temperature may be significantly reduced or eliminated.
Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a motor vehicle internal combustion engine together with apparatus for controlling the engine in accordance with the preferred embodiment of the invention.
FIG. 2 is a block diagrammatic view of the operation of flange temperature prediction control system according to the present invention.
FIG. 3 is a more detailed block diagrammatic view of the mixing model of FIG. 2 .
FIG. 4A is a plot of the x calibration versus air mass.
FIG. 4B is a plot of Tau 1 versus air mass.
FIG. 4C is a plot of Tau 2 versus air mass.
FIG. 5 is a flow chart of the operation of the exhaust gas flange temperature prediction algorithm.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following example the same reference numerals and signal names will be used to identify the respective same components and the same electrical signals in the various views.
The present invention seeks to more accurately predict the exhaust gas temperature by taking into consideration its second order characteristic. The modeling may be performed using a thermocouple model so that verification may be performed using non-road tested data.
Referring now to FIG. 1, internal combustion engine 10 is controlled by electronic controller 12 . Engine 10 has a plurality of cylinders 14 , one of which is shown. Each cylinder has a cylinder wall 16 and a piston 18 positioned therein and connected to a crankshaft 20 . A combustion chamber 22 is defined between piston 18 and cylinder wall 16 . Combustion chamber 22 communicates between intake manifold 24 and exhaust manifold 26 via a respective intake valve 28 and an exhaust valve 30 . Intake manifold 24 is also shown having fuel injector 32 coupled thereto for delivering liquid fuel in proportion to the pulse width of signal (FPW) from controller 12 . The fuel quantity together with the amount of air mass in the intake manifold 24 defines the air/fuel ratio directed into combustion chamber 22 . Those skilled in the art will also recognize that engine may be configured such that the fuel is injected directly into the cylinder of the engine in a direct injection type system.
A catalyst 34 is coupled to exhaust manifold 26 through exhaust system 36 . Exhaust manifold 26 is coupled to exhaust system 36 at exhaust flange 37 . Catalyst 34 is used to reduce tail pipe emissions by performing reduction and oxidation reactions with the combustion gasses leaving combustion chamber 22 through exhaust valve 30 .
Controller 12 is shown as a conventional microcomputer 41 including a microprocessing unit (CPU) 38 , input/output ports 40 , a computer storage medium such as read-only memory 42 and random access memory 44 , and a conventional data bus 46 therebetween. The computer storage medium has a computer program therein for controlling the CPU to determine the temperature at exhaust flange 37 as will be further described below. The computer storage medium has a calibrated table therein for determining the engine operating conditions at various engine operating conditions. The table may be determined during calibration on a dynamometer.
Controller 12 is shown receiving various signals from sensors coupled to engine 10 . The various sensors may include a mass airflow sensor 47 used to provide an air mass signal to controller 12 . An engine speed sensor 48 is used to generate an engine speed signal corresponding to the rotational speed of crankshaft 20 . An exhaust gas oxygen sensor 50 positioned upstream of catalyst 34 provides a signal corresponding to the amount of oxygen in the exhaust gas prior to the catalyst. One suitable example of an exhaust gas oxygen sensor is a UEGO sensor. A second exhaust gas oxygen sensor 52 may be coupled to the exhaust system after catalyst 34 . One suitable example of an UEGO sensor downstream of catalyst 34 is a heated exhaust gas oxygen sensor.
A throttle body 56 having a throttle plate 58 and a throttle position sensor 60 is illustrated. Throttle position sensor 60 provides controller 12 with an electrical signal corresponding to the desired driver demand.
Referring now to FIG. 2, a block diagram of a method for operating a control system 70 that determines the exhaust gas flange temperature is illustrated. Block 72 represents a steady state temperature map of the exhaust gas temperature that is a function of various engine operating conditions such as air mass, spark timing, exhaust gas recirculation, air/fuel ratio, load and engine speed. Of course, not all of these engine operating parameters need be included to obtain the temperature (T ss ). The steady state temperature table is determined experimentally for each type of configuration of engine. That is when different geometric configurations of the engine, engine displacement, exhaust system are used a steady state temperature map is determined for each. Preferably, the steady state temperature table is determined during engine dynamometer testing. As will be evident to those skilled in the art, the engine often operates outside of a steady state condition and therefore the need for determining the exhaust gas temperature at various conditions is evident. That is, the steady state temperature is only one factor of many to be considered. The engine airflow at flange 37 is divided into a first flow or rate 74 and a second flow or rate 76 . The two airflows 74 , 76 are calculated airflows. As was found, the present invention provides a substantially improved flange temperature exhaust gas prediction.
The first flow 74 is directed to a first order heat transfer model 78 to obtain a first temperature T1. The first order heat transfer model models the heat transfer of the physical engine model. One example of a heat transfer model is: T 1 T + 1 τ T 1 = 1 τ T s where T ss + T1 2 = T 1 T1 = 2 T 1 - T ss
The thermal mass of the manifold and exhaust pipes before the catalyst are taken into consideration. Of course, the heat transfer model need only be determined once for a particular engine model and exhaust geometry. Such determinations are well known thermodynamic determinations. The heat transfer model averages the first flange exhaust temperature prediction (New_Ave) at its output. The heat transfer model 78 also has an air mass input 80 . The heat transfer of the heat transfer model is dependent on the air mass since the Tau value is dependent on the air mass.
Heat transfer model 78 has a feedback loop 82 having a memory block 84 which signifies the storing of information to the memory 44 for later use. Also, an initial condition box 86 is present in feedback loop 82 . Initial condition box 86 signifies the initial operating temperature of the engine. This block provides the model and initial operating temperature to average into an old average input Old_Ave. One example of a running average is:
new_av=old_av*(1−fk)+new_val*fk
where:
fk=Filter constant in a differential equation
new_val=Latest temperature value
tc=Time constant
As the engine operates the average temperature (running average) will thus increase as the temperature of the exhaust manifold, exhaust system, and catalyst increases. A first calibration box 88 having the calibration parameter Tau 1 is also an input to model 78 . Tau 1, as will be further shown below, is dependent on the air mass and changes in response thereto.
Second flow 76 is a flow that bypasses the first order heat transfer model to provide a second temperature T2 to a mixing model 90 . The temperature T2 corresponds to the steady state temperature T ss . Mixing model 90 generates a first flange temperature T flange1 by modeling the airflow into a bypass portion and heat transfer model portion. The second order characteristic of the temperature of the airflow is modeled more closely by two first order airflows.
The flange exhaust temperature T flange1 may be used alone or in combination with a thermocoupled model 92 . The thermocouple model 92 is an optional portion of the control system. The thermocouple model 92 allows verification of the exhaust gas temperature at the flange. By modeling the thermocouple, the output of model 92 should correspond directly to an actual thermocouple on the vehicle during testing. Thermocouple model 92 has an air mass input 94 because the thermocouple model on Tau 2 input 93 is dependent on the air mass in a similar manner to that of heat transfer model 78 . In addition, a feedback loop 96 including memory 98 that stores values into memory and an initial condition block 100 . The initial condition block is coupled to an Old_Avg input to model 92 . The output of thermocouple model 96 provides a second flange temperature T flange2 which is the output of the control system 70 when a thermocouple is taken into consideration. One model is given by the formula: T flange2 = T flange1 + τ 2 T flange1 t
where τ 2 , in general is a function of the exhaust flow rate and thermocouple size, is the temperature of the thermocouple junction, and the output of the mixing model and T flange2 is the temperature of the exhaust gas at the output of the model.
Referring now to FIG. 3, mixing model 90 is illustrated in further detail. Mixing model 90 receives the temperature T1 from heat transfer model 78 and temperature T2 from bypass loop 76 . A constant block 102 which is coupled to an air mass (AM) input 104 is coupled to temperature T1 through a multiplier block 106 . A constant block 108 , having a constant of 1, is summed with the constant block 102 in addition block 110 . The constant actually is provided to an inverting input of addition block 110 so that the output is (1−XG). The output of addition block 110 is multiplied by the temperature T 2 at multiplication block 112 . The output of multiplication block 112 and multiplication block 106 are summed together in addition block 114 to provide the temperature of the flange. As can be seen, the percentage amount of temperature through the heat transfer model is controlled by the constant block. As was mentioned above, the amount of heat bypassing and passing through the heat transfer model is dependent on the air mass. Thus, as the air mass changes the value X changes as well as will be shown below. The temperature of the T flange1 is given by the given by the relation:
T flange1 =( T 1)( XG )+( T 2)(1 −XG ).
Referring now to FIG. 4A, raw dynamometer data is plotted for the X value shown in block 102 of FIG. 3 versus air mass. Air mass (AM) is measured in pounds per minute (PPM). As can be seen, the calibration data is the curve fitted line that best represents the dynamometer points therein.
Referring now to FIG. 4B, the calibration parameter Tau1 is plotted versus air mass. Raw dynamometer data was used to obtain the data which has been curve fitted using the solid line shown therein.
Referring now to FIG. 4C, the calibration parameter Tau2 is plotted using dynamometer data. A curve fit shown in the solid line is used in the model above. As can be seen in FIGS. 4A-4C, the X, Tau1 and Tau2 values are higher with lower airflow and decrease as the air mass increases. The solid lines represent the output of the model without the need for on-road testing and recalibration normally performed in such determinations.
Referring now to FIG. 5, a flow chart illustrating the prediction algorithm according to the present invention is shown. In step 120 the steady state engine temperature data is mapped. As mentioned above, the steady state engine map is preferably performed using dynamometer testing on the particular type of engine. The steady state engine temperature is determined from the map. In step 122 , a fraction of the airflow lost to the atmosphere from the exhaust manifold is modeled in the heat transfer model based upon the steady state engine temperature. The remaining portion of the airflow is not affected by temperature losses in block 124 . Therefore, this is the steady state temperature. The airflows are combined in block 126 . In block 128 , a thermocouple may also affect the flange temperature if provided. This block, as mentioned in FIG. 2, is optional. The output of the system in response to the mixed gas and the thermocouple model if so provided is generated in step 130 .
The capability of adjusting the heat transfer model and thermocouple model as well as the mixing model according to the air mass of engine yields an improved determination of the temperature of the airflow at the flange. This result may then be used to more accurately determine other downstream temperatures including the catalyst input temperature, the catalyst midbed temperatures, and exhaust gas oxygen sensor temperatures.
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
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A control system and method for controlling an engine ( 10 ) of an automotive vehicle having a catalyst ( 34 ) and controller ( 40 ) is set forth herein. The controller ( 40 ) is configured to determine a first exhaust flow rate and a second exhaust flow rate based on a flow rate of the exhaust gases. The controller is further configured to determine a first temperature (T1) of exhaust gases associated with the first exhaust flow rate based on a steady state temperature and an amount of heat transferred from the exhaust gases associated with the first exhaust flow rate to an exhaust system. The controller is further configured to determine a second temperature of exhaust gases associated with the second exhaust flow rate based on the steady state temperature. The controller is further configured to determine the catalytic converter temperature based on the first temperature and the second temperature.
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FIELD OF THE INVENTION
The present application relates generally to devices that can be used as both telephones and TV remote controls.
BACKGROUND OF THE INVENTION
TV remote controls are ubiquitous. Typically, viewers watching TV keep their remotes close at hand. The same might not be true of telephones, however. Consider that people arriving home may leave their mobile phones in chargers or on countertops or other locations that might not be nearby the TV, so that they must rise off the couch and seek their phones to respond to incoming calls.
SUMMARY OF THE INVENTION
A TV system includes a TV and a remote control (RC) configured to send wireless command signals such as to change a tuned-to channel displayed on the TV. The RC also includes a microphone into which a person can speak. The TV system is configured to wirelessly receive signals representing telephony signals from a wireless telephone. The microphone of the RC can receive acoustic signals from a person, and the TV system is configured to wirelessly send signals representing the acoustic signals to the wireless telephone.
The telephony signals can represent, e.g., a caller's voice. The TV system may be configured to receive a presence signal from the wireless telephone indicating that the wireless telephone is nearby the TV system and in response enabling use of the RC as a telephone. This presence signal can be sent using Bluetooth.
If desired, the RC can include a speaker on which telephony signals are displayed. In addition or alternatively, the TV's speakers can be used to display a caller's voice. The signals representing telephony signals can be received on Bluetooth and the signals representing the acoustic signals can also be sent on Bluetooth. The TV may act as a relay between the RC and the wireless telephone.
In another aspect, a TV remote control (RC) has a hand-held housing, a keypad on the housing, and a microphone in the housing. A processor is in the housing may receive signals from the microphone and keypad. A TV remote control signal generator is also in the housing and is controlled by the processor to send signals such as channel control commands to the TV. The RC is also configured to wirelessly transmit signals representing voice signals received at the microphone.
In another aspect, a presence signal is sent via Bluetooth from a mobile phone to a TV system. In response to the presence signal, a telephone feature is enabled in which phone calls to the phone are relayed to the TV system. A user can input voice signals to a remote control (RC) associated with the TV, with the signals being relayed from the RC back to the phone.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an example system in accordance with present principles; and
FIG. 2 is a flow chart of example logic that may be used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 , a system is shown, generally designated 10 , which includes a TV system having a TV 12 and remote control (RC) 14 . It is to be understood that all of the components of the TV 12 may be included in one chassis or some components, e.g., a tuner, may be included in a set-top box or other ancillary device connected to the TV 12 .
As shown, the TV 12 includes a TV display 16 such as a cathode ray tube or flat panel matrix display in standard and/or high definition. The display 16 is mounted on a TV chassis 18 , and the chassis 18 also supports one or more audio speakers 20 . Programming from a channel tuned to by means of a TV tuner 22 is presented on the display 16 and speakers 20 .
The tuner 22 may be controlled by a TV processor 24 accessing data and/or computer instructions stored on a tangible computer readable medium 26 such as solid state storage, disk storage, or other appropriate electronic storage. To receive wireless TV commands such as channel control commands, volume change commands, and the like from the RC 14 , the TV 12 typically includes an infrared or other type of TV command receiver 28 sending signals to the TV processor 24 . Furthermore, the TV 12 may include a short range radiofrequency (RF) transceiver 30 such as a Bluetooth transceiver that sends signals to the TV processor 24 . In the embodiment shown, the TV 12 does not include a transceiver configured to communicate with the public telephony system.
Turning to the RC 14 , to send TV commands to the TV 12 the RC typically includes an infrared or other TV command transmitter 32 controlled by a RC processor 34 . Furthermore, the RC 14 may include a short range radiofrequency (RF) transceiver 36 such as a Bluetooth transceiver that sends signals to the RC processor 34 . The RC processor 34 may access data and/or computer instructions stored on a tangible computer readable medium 38 such as solid state storage, disk storage, or other appropriate electronic storage and may receive voice signal input from a microphone 40 and output voice data on one or more speakers 42 . The RC processor 34 may also receive user input from a RC keypad 44 . The above-described RC components typically are contained on a portable hand-held housing 46 .
FIG. 1 also shows that a wireless telephone 48 may communicate with the TV system described above. With more particularity, the wireless telephone 48 , which may be, without limitation, a global systems for mobile communications (GSM) telephone, a code division multiple access (CDMA) telephone, a time division multiple access (TDMA) telephone, a frequency division multiple access (FDMA) telephone, a space division multiple access (SDMA), a wideband-CDMA telephone, an orthogonal frequency division multiplexing (OFDM) telephone, etc. includes a wireless telephony transceiver 50 for communicating with wireless telephony base stations in accordance with principles known in the art.
The telephony transceiver 50 may be controlled by a telephone processor 52 accessing data and/or computer instructions stored on a tangible computer readable medium 54 such as solid state storage, disk storage, or other appropriate electronic storage. In some embodiments the telephone 48 includes a position receiver 56 such as a global positioning satellite (GPS) receiver providing input to the telephone processor 52 , as well as a short range radiofrequency (RF) transceiver 58 such as a Bluetooth transceiver communicating with the telephone processor 54 . The telephone 48 may also include a telephone display 60 such as a liquid crystal display (LCD) or light emitting diode (LED) display or other type of matrix display that is controlled by the telephone processor 52 , as well as a telephone keypad 62 for inputting user commands to the telephone processor 52 . The above-described telephone components typically are contained on a portable hand-held housing 64 .
With the above example system architecture in mind, attention is now drawn to FIG. 2 , which illustrates logic some or all of which may be embodied in the computer-readable media described above. Commencing at block 66 , in some implementations the phone 48 can send a presence signal to the TV system when the user, e.g., carries the phone into the house in which the TV system is disposed. This presence signal may be user-generated or it may be in response to signals from the position receiver 56 informing the phone processor 52 that the phone is located in a user-defined geographic location at which the user wishes to use the TV system for telephony purposes as described below. Yet again, the phone 48 may simply broadcast the presence signal periodically, or in response to being connected to a battery charger. In any case, the presence signal may be sent via Bluetooth. Preferably, the TV system acknowledges the presence signal to the telephone.
At block 68 , in response to receiving the presence signal, the TV system may enable the telephone feature described below. In other embodiments the feature may always be enabled if unusable due to the absence of the telephone 48 . The logic of block 68 may be executed by one or both of the TV processor 24 and RC processor 34 .
Moving to block 70 , an incoming call to the telephone 48 is sent using, e.g., Bluetooth to the TV system. Recall that the presence signal sent by the telephone 12 preferably is acknowledged by the TV system, so that the telephone processor 52 knows that it is nearby the TV and, thus, that it is to relay calls to the TV system. The step at block 70 may additionally include, in addition to the automatic enabling of telephone-to-TV system communication, a user input as well, allowing the user, by means of a graphical user interface (GUI) presented on, e.g., the TV display 16 or RC that can be automatically displayed upon receipt of the presence signal, to allow the user to select “yes” to enabling telephone operation of the TV system.
The call is then displayed on the RC 14 . Specifically, using Bluetooth the telephone 48 can send ring tones and voice signals to the TV 12 , which can relay the signals to the RC. The signals may be displayed on the TV speakers 20 and/or on the RC speaker 42 .
Further, at block 72 a person holding the RC 14 can speak into the microphone 40 , and the RC 14 transmits Bluetooth signals representing the person's voice at block 76 . These signals are sent to the telephone 48 , which relays them over the telephony network. In this way, a person can conduct a telephone conversation using the RC 14 as a repeater and the telephone 48 as a relay node.
In some embodiments, only the TV 12 need have Bluetooth capabilities; signals, representing both TV command signals and voice signals, may be exchanged between the RC 14 and TV 12 using the infrared link provided by the IR transmitter 32 and IR receiver 28 , with the TV 12 relaying voice signals to the telephone 48 . In other embodiments, both the TV 12 and RC 14 have Bluetooth capabilities, exchanging voice-related signals on Bluetooth and TV command signals on the IR link with the TV 12 relaying voice signals to the telephone 48 . In still other embodiments, the RC 14 may communicate voice signals directly to the telephone 48 using Bluetooth.
While the particular COMBINED TELEPHONE/TV REMOTE CONTROL is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.
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When a person arrives home with his mobile phone, the phone sends a presence signal via Bluetooth to the TV system in the home, which enables a telephone feature in which phone calls to the phone are relayed to the TV system. The remote control associated with the TV has a microphone and speaker so that a person can use the RC not only to control the TV but also to respond to phone calls, with the TV system relaying voice signals from the RC back to the phone.
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FIELD OF THE INVENTION
The present invention relates to the technical field of controlling audio systems, which comprise both an acoustic output device such as a loudspeaker and an acoustic input device such as a microphone. In particular, the present invention relates to a method for controlling an adaptation of an audio output signal of an audio device to a current acoustic environmental condition of the audio device. Further, the present invention relates to a data processor, to a computer-readable medium and to an audio device, which are adapted to control and/or to carry out the above mentioned method for controlling an adaptation of an audio output signal to a current acoustic environmental condition.
BACKGROUND OF THE INVENTION
Depending on the situation in which a mobile device such as for instance a mobile phone is used, the desired level of an audio playback signal or of a ringtone indicating an incoming call or an incoming Short Message Service (SMS) needs to be different. For example, when in a meeting or in a rather silent office or home condition with other people in the room, one would like the playback volume to be rather low in order not to disturb other people. On the other hand, when being in a noisy environment such as a car, a pub, or in the street, one would like the ringtone to be loud enough so that the alert of an incoming call is always audible. Furthermore, when the mobile device is covered or kept in a closed environment like a pocket or bag, the ringtone is acoustically attenuated and is likely not to be heard at all even in low noisy circumstances.
In most mobile devices the playback volume of the ringtone can be adjusted manually, typically as a setting in the mobile phone's menu system. Alternatively, the ringtone volume might be controlled by so-called profiles. Thereby, the user can manually switch from one profile to another in order to change the ringtone volume. In addition, most mobiles allow the ringtone volume to increase over time, starting from a very soft the moment the call comes in, to very loud after a fixed period of time. However, manual ringtone adjustment or profile switching has the disadvantage that it requires user interaction, something people tend to forget, resulting in undesirable phone behavior. An automatic volume increase is not ideal either, because when one is located in a noisy environment only the very last part of the ringtone will be loud enough. However, because it will be audible only for a very short period, chances are high that the alert is not heard by the user and unintentionally the voice mail system will answer the incoming call.
Further, in most mobile devices a vibration feature can be enabled so that the alert of an incoming call can also be felt when keeping the mobile in a pocket in close contact with the body. However, some people do not want to have the vibration function enabled at all times or they simply tend to forget to enable it because it requires the user's attention and manual interaction. Furthermore, when the mobile is kept in a pocket or bag, there is no immediate contact with the user's body so that the vibration function will not help in notifying an alert respectively an incoming call.
More advanced mobile phones have built-in sensors like an ambient light sensor, a proximity sensor, an accelerometer, etc. Such sensors can be used to learn something about the environment of the mobile phone. However the information extracted using these sensors is typically not conclusive. For example, the ambient light sensor can be used to detect whether or not the mobile phone is covered or is located in a pocket or bag. However, it cannot distinguish this situation from the situation where the mobile phone is lying on a night table in the dark. In the first situation one would like to increase the loudness of the ringtone to compensate for the fact that it will be acoustically attenuated, whereas in the second situation one would like the ringtone playback to be gentle.
It has been proposed to measure the environmental noise level using the built-in microphone of the mobile device during a short period of time before starting an audio playback signal or a ringtone. However, this could lead to practical robustness issues as the level of an audio playback signal or ringtone is only based on the noise level estimation before the audio playback or the ringtone becomes effective. It is not possible to deal with variations in the environmental noise after the audio playback signal or the ringtone has started.
It has been further proposed to measure the noise level during audio playback signal or ringtone. However, due to a typically high acoustic coupling between the speaker and the microphone of a mobile device, a continuous echo of the audio playback signal or the ringtone will be dominant with respect to the captured ambient noise. A direct noise level measurement based on the microphone signal will lead to incorrect noise estimations, resulting in an incorrect audio playback signal or ringtone adjustment.
Furthermore, an acoustic echo canceller has been proposed, which is capable of removing the audio playback signal or the ringtone from the microphone signal. However, due to a typically very high acoustic coupling between the speaker and microphone on a mobile device, any small mismatch between the estimated echo and the echo captured by the microphone affects the quality of the remaining microphone signal. Hence, by removing the audio playback echo or the ringtone echo, the acoustic echo canceller degrades the remaining residual signal and hence also the captured ambient noise. This leads to an incorrect noise level estimation.
As elucidated above, requirements with respect to audio playback or ringtone are dependent on the situation in which the mobile device is being used and known procedures for measuring the noise of the ambient environment suffer from a high acoustic coupling between the speaker of the mobile device and the microphone of the mobile device. Therefore, there may be a need for automatically adapting the volume of an audio playback signal or a ringtone depending on the current ambient conditions in an appropriate, easy and effective manner.
OBJECT AND SUMMARY OF THE INVENTION
This need may be met by the subject matter according to the independent claims. Advantageous embodiments of the present invention are described by the dependent claims.
According to a first aspect of the invention there is provided a method for controlling an adaptation of a behavior of an audio device to a current acoustic environmental condition. The provided method comprises (a) monitoring an audio output signal being provided to an acoustic output device of the audio device for outputting an acoustic output signal, (b) measuring an audio input signal being provided by an acoustic input device of the audio device, wherein the audio input signal is indicative for a feedback portion of the acoustic output signal and for the current acoustic environmental condition, (c) determining a relation between the audio output signal and the audio input signal and (d) adapting the behavior of the audio device based on the determined relation.
This first aspect of the invention is based on the idea that an environmental background noise has a strong impact on the relation between the audio output signal and the captured audio input signal. Therefore, by measuring and/or monitoring this relation important information about the acoustic environment of the audio device can be extracted. In particular, compared to a silent surrounding a significant environmental background noise may disturb this relation. In accordance with the described method the measurement and a subsequent analysis of this disturbance may be used to steer the adaptation of the audio output signal to a clear audible level with respect to the environmental background noise. Thereby, an ambient-aware adaption of the audio output signal can be realized.
It has to be mentioned that according to the invention it is not necessary, however not forbidden, to directly measure the ambient respectively the environmental noise. Such a direct measurement could be carried out either before or during the described audio output signal adaptation method.
Generally speaking, the relation between the audio output signal and the audio input signal reflects the acoustical characteristics of the audio device and of the environment of the audio device, which may comprise both the acoustic output device and the acoustic input device. Monitoring the dynamics or changes and disturbances in this relation with respect to reference situations (e.g. no background noise, audio device lying freely on a table), may reveal information about the acoustic environment of the audio device and changes in this acoustic environment.
The described feedback portion of the acoustic output signal may be given by an acoustic coupling between the acoustic output device and the acoustic input device. Thereby, at least a portion of the acoustic output signal is fed back from the acoustic output device to the acoustic input device. Of course this portion strongly depends on the corresponding acoustic path, which may be characterized by certain attenuation and/or a certain modification of the frequency distribution of the fed back acoustic output signal.
The terms “audio output signal” and “audio input signal” refer to non-acoustical signals. In particular, the term “audio output signal” may refer to an electrical signal which is provided to the acoustic output device in order to be transformed into the acoustic output signal (i.e. a sound wave). Correspondingly, the term “audio input signal” may refer to an electrical signal which is produced by the acoustic input device in response to the receipt of the acoustic input signal and/or environmental background sound signals, which are also sound waves.
It has to be mentioned that the described relation between the audio output signal and the audio input signal can also be determined by using derivative signals of the audio output signal and/or the audio input signal. Depending on the relation between the audio output signal or the audio input signal and the respective derivative signal, the relation involving at least one derivative signal will differ in a known manner such as for instance a certain factor from the direct relation between the audio output signal and the audio input signal.
It is mentioned that the term “determining” has to be understood in a wide manner. Determining may mean for instance estimating (in particular when there is no exact value for the ratio), measuring or calculating.
The behavior of the audio device may be any functionality of the audio device, which might be introduced, removed or modified based on the determined relation between the audio output signal and the audio input signal. Thereby, the behavior adaption may be carried out when the determined relation (a) reaches a predefined value, (b) changes by a predefined difference, (c) exhibits a certain dynamic change and/or (d) shows a certain disturbance with respect to a reference value.
According to an embodiment of the invention the behavior of the audio device is given by an amplitude and/or a frequency of the audio output signal, an amplitude and/or a frequency of a vibrating mechanism of the audio device and/or a modification of the operation of a display of the audio device. The modification of the display may comprise for instance a deactivation, an activation, an enlightening of a dimming.
According to a further embodiment of the invention the relation between the audio output signal and the audio input signal is determined by applying a cross-correlation procedure, an adaptive filtering procedure and/or a coherence estimation procedure. This may provide the advantage that well-known procedures for relating different signals with each other can be employed. Of course, also other non-mentioned procedures might be used for the determination of the described relation. For instance the adaptive filtering procedure may be carried out by means of an acoustic echo canceller adaptive filter such as for instance a normalized least mean square adaptive filter.
According to a further embodiment of the invention the acoustic output device is a loudspeaker and/or the acoustic input device is a microphone. This may provide the advantage that the described audio output signal adaptation method can be carried out with many different types of audio devices. Thereby, it is not possible that the audio device itself comprises the loudspeaker and/or the microphone. The described method can also be applied if the respective audio device comprises at least interfaces for directly or indirectly connecting the loudspeaker and/or the microphone to the audio device.
The described method may exhibit the most important advantages over prior art audio output adaptation control methods if there is a strong acoustic coupling between the loudspeaker and the microphone. In this case direct noise level measurements from the captured microphone signal are mostly not possible because the ambient noise is masked by the feedback portion of the acoustic output signal.
The audio output signal may be any signal, which can be converted by the loudspeaker into sound waves. In particular, the acoustic output signal may be an audio playback signal or an alarm signal. Thereby, an ambient-aware music playback or an ambient-aware alerting of a user may be realized. In this context, if the audio device, on which the described method is carried out, is for instance a mobile phone, the alarm signal may be a ringtone indicating the user of the mobile phone an incoming call and/or an incoming SMS.
According to a further embodiment of the invention the method further comprises comparing the determined relation between the audio output signal and the audio input signal with at least one reference relation. Thereby, adapting the behavior of the audio device further takes into account a result of the comparison between the determined relation and the reference relation.
This may provide the advantage that the determined relation can be assigned to or classified into different groups of relations. Depending on the respective group different measures for adapting the behavior of the audio device can be carried out.
This further embodiment allows solving the so called “closed environments” problem, because the determined relation between the audio output signal and the audio input signal reflects the acoustical characteristics of the audio device within its acoustic environment. When the audio device is in a closed environment like a pocket or a bag or when it is covered by soft or hard material, the acoustical coupling between the acoustic output device respectively the loudspeaker and the acoustic input device respectively the microphone is different. Thereby, the acoustical coupling will be lower or higher or will be continuously changing due to movements in the pocket or bag compared to when the audio device is freely lying for instance on a table. This situation dependent deviation can be detected by comparing the acoustical coupling measure given by the comparison of the determined relation with a reference situation relation. The situation dependent deviation can be used for adjusting the audio output signal in order to increase the perceived loudness.
According to a further embodiment of the invention the method further comprises comparing the determined relation between the audio output signal and the audio input signal with a threshold. Thereby, if the determined relation is larger or smaller than the threshold, adapting the behavior of the audio device comprises increasing the signal level of the audio output signal.
It has to be mentioned that the accomplishment of the described signal level increase may be made dependent whether the amplitude of the initial audio output exceeds a further threshold, which can also be denominated a volume threshold.
In case of significant ambient noise, this determined relation will be disturbed by the captured ambient noise. Hence, by monitoring the dynamics in or disturbances on the determined relation for audio output signal levels, which are larger than the further threshold (volume threshold), a significant disturbance beyond the threshold indicates that the noise component is dominant and that the audio output signal is not loud enough. As long as disturbances beyond the threshold are measured, the audio output signal needs to be enhanced further.
A proper choice of the second (volume) threshold and/or the first (disturbance) threshold may depend on the concrete acoustical coupling characteristics of the audio device. Therefore, the threshold and/or the further threshold may need to be tuned to the acoustical characteristics of the audio device in order to provide for an optimal audio output signal adaptation. The mapping of the dynamic range of the determined relation, changes or disturbance on this relation onto the how and the amount of adaptation may need to be tuned to the acoustical characteristics of the audio device.
This embodiment of the invention may provide the advantage that indirect noise measurements are made possible even for an audio device having a strong acoustical coupling between the acoustic output device and the acoustic input device. This holds also for very silent environmental conditions.
In case of silent environmental conditions, the determined relation between the audio output signal and the audio input signal reflects the acoustical characteristics of the audio device in its silent environment. Thereby, the audio input signal, which is captured by the audio input device, represents a signal mix caused by the environmental background noise and the feedback portion of the acoustic output signal.
According to a further embodiment of the invention the audio device is a mobile communication end device. The communication end device may be capable of connecting with an arbitrary telecommunication network access point such as for instance a base station. The communication end device may be a cellular mobile phone, a Personal Digital Assistant (PDA), a notebook computer and/or any other movable communication device.
The described method may provide the advantage that an ambient-aware ringtone can indicate an incoming call. Thereby, the adaptation and in particular an increase of the loudness or a decrease of the loudness of the ringtone may depend on the acoustical characteristics of the environment of the mobile communication end device.
In this respect it is mentioned that the ringtone may comprise any arbitrary sound like a harmonic music, an identifiable noise or any sequence of tones having any arbitrary tone color.
According to a further embodiment of the invention the method further comprises detecting a picking up of the mobile communication end device based on a change in the determined relation between the audio output signal and the audio input signal. This may provide the advantage that when answering the mobile phone it can be immediately detected when the user grabs the mobile communication end device. Thereby, the detection may rely on a rapid change of the acoustic coupling between the loudspeaker and the microphone of the mobile phone when the user puts his hand around the mobile phone or when the user moves the mobile phone from its initial location.
Generally speaking, the described method provides a technique for acoustically detecting a picking up of the mobile phone for answering incoming calls based on monitoring the acoustic coupling given by the determined relation between the audio output signal and the audio input signal. Thereby, the mobile phone can be steered to adapt in particular the loudness of the ringtone towards a desired behavior.
According to a further embodiment of the invention the method further comprises generating a sensor signal by a sensor device. Thereby, adapting the audio output signal further takes into account the sensor signal.
The described sensor device may comprise any context sensor, which is capable of detecting a measurable variable of the audio device and/or of the environment of the audio device. The additional consideration of the sensor signal may provide the advantage, that the audio output signal can be adapted very precisely towards its desired behavior depending on the environmental acoustic conditions.
Generally speaking, the adaptation of the audio output signal can be further enhanced by using the acoustical detection in combination with at least one sensor signal being provided by at least one other context sensor. Thereby, additional information about the environment of the audio device might be extracted in order to make the adaptation of the audio output signal even more reliable.
According to a further embodiment of the invention the sensor device comprises a light sensitive sensor, a motion sensor, an acceleration sensor and/or a proximity sensor. At least one of such sensors, which may be built-in sensors of advanced mobile phones, can be used to learn something more specific about the environment of the audio device.
In this respect it is mentioned that the information extracted exclusively from one of such sensors is typically not conclusive. For example, an ambient light sensor can be used to detect whether or not the audio device is covered or is located in a pocket or bag. However, the ambient light sensor cannot distinguish this situation from the situation wherein the audio device is lying on a night table in the dark. In the first situation one would like to increase the loudness of the acoustic output signal to compensate for the fact that it will be muffled, whereas in the second situation one would like the acoustic output signal to be gentle. However, when additionally taking into account the determined relation between the audio output signal and the audio input signal, it may be possible to reliably distinguish between the described first situation and the second situation.
It is explicitly pointed out that two or even more sensor signals being generated by two or even more sensors can be taken into account for adapting the audio output signal. Preferably, these sensors are of different nature such that different types of information regarding the audio device environment and/or the operational state of the audio device can be used for adapting the audio output signal in a reliable manner. Thereby, the term “operational state” also includes the state of motion and/or the state of acceleration of the audio device.
According to a further aspect of the invention there is provided a data processor for controlling an adaptation of a behavior of an audio device to a current acoustic environmental condition of the audio device. Thereby, the data processor is adapted for performing the method in accordance with any one of the above-described embodiments.
Also this further aspect of the invention is based on the idea that by measuring and/or monitoring the relation between the audio output signal and the captured audio input signal valuable information about the acoustic environment of the audio device can be extracted. This information can be taken into account for optimally adapting the behavior of the audio device and in particular the signal level of the audio output device towards a desired and user comfortable level.
The described data processor may be a part of a system for acoustically detecting the changes in the acoustic environment of the audio device in order to steer the audio output signal and, as a consequence, also the acoustic output signal toward a desired behavior. Thereby, the desired behavior may be characterized by a clear perceptibility of the acoustic output signal in case of a noisy environment and by a rather gentle level of the acoustic output signal in case of a comparatively silent acoustic environment.
According to a further aspect of the invention there is provided an audio device comprising (a) an acoustic output device for outputting an acoustic output signal based in response to an audio output signal, (b) an acoustic input device for providing an audio input signal in response to a feedback portion of the acoustic output signal and/or in response to a current acoustic environmental condition, and (c) a data processor. The data processor is adapted to control any embodiment of the above described audio device behavior adaptation method.
The described audio device may be a mobile communication end device such as for instance a mobile phone. The acoustic output device may be for instance a loudspeaker. The acoustic input device may be for instance a microphone.
According to a further embodiment of the invention the audio device further comprises a sensor device, which is coupled to the data processor. Thereby, the data processor is adapted to take into account a sensor signal generated by the sensor device for adapting the audio output signal.
The described sensor device may be capable of detecting any measurable variable of the audio device and/or of the environment of the audio device. By taking into account also the sensor signal the audio output signal can be adapted even more precise towards a desired behavior depending on the environmental acoustic conditions.
The sensor device may comprise any type of sensor such as for instance a light sensitive sensor, a motion sensor, an acceleration sensor and/or a proximity sensor.
According to a further aspect of the invention there is provided a computer-readable medium on which there is stored a computer program for controlling a behavior of an audio device to a current acoustic environmental condition. The computer program, when being executed by a data processor, is adapted for controlling any embodiment of the above described audio output signal adaptation method.
According to a further aspect of the invention there is provided a program element for controlling an adaptation of a behavior of an audio device to a current acoustic environmental condition. The program element, when being executed by a data processor, is adapted for controlling any embodiment of the above described audio output signal adaptation method.
The program element may be implemented as computer readable instruction code in any suitable programming language, such as, for example, JAVA, C++, and may be stored on a computer-readable medium (removable disk, volatile or non-volatile memory, embedded memory/processor, etc.). The instruction code is operable to program a computer or any other programmable device to carry out the intended functions. The program element may be available from a network, such as the World Wide Web, from which it may be downloaded.
The invention may be realized by means of a computer program respectively software. However, the invention may also be realized by means of one or more specific electronic circuits respectively hardware. Furthermore, the invention may also be realized in a hybrid form, i.e. in a combination of software modules and hardware modules.
It has to be noted that embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments have been described with reference to method type claims whereas other embodiments have been described with reference to apparatus type claims. However, a person skilled in the art will gather from the above and the following description that, unless other notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters, in particular between features of the method type claims and features of the apparatus type claims is considered as to be disclosed with this application.
The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in accordance with the invention an audio device, which comprises an adaptive filter for determining the relation between the audio output signal x′(t) and the audio input signal z(t).
FIG. 2 shows a block diagram indicating the operation of the audio device depicted in FIG. 1 .
DESCRIPTION OF EMBODIMENTS
The illustration in the drawing is schematically. It is noted that in different Figures, similar or identical elements are provided with reference signs, which are different from the corresponding reference signs only within the first digit.
FIG. 1 shows an audio device 100 in accordance with the invention. According to the embodiment described here the audio device is a mobile phone 100 . The mobile phone comprises an acoustic output device 110 and an acoustic input device 120 . The acoustic output device is a loudspeaker 110 , the acoustic input device is a microphone 120 . The loudspeaker 110 is driven by an audio output signal x′(t). The audio output signal x′(t) is generated by a loudness enhancement unit 111 . The audio output signal x′(t) is generated based on an original audio signal x(t), which is fed to the loudness enhancement unit 111 . According to the embodiment described here the original audio signal x(t) and the audio output signal x′(t) represent a ringtone for the mobile phone 100 . The ringtone may in particular indicate an incoming call.
Due to a relatively close distance between the loudspeaker 110 and the microphone 120 there will be a strong acoustic coupling between the loudspeaker 110 and the microphone 120 . As a consequence, a feedback signal, which is a portion of the acoustic output signal generated by the loudspeaker, will propagate from the loudspeaker 110 to the microphone 120 . The strength of this coupling depends on the acoustic property of the mobile phone 100 and of the environment of the mobile phone 100 . If the mobile phone 100 is located for instance in a pocket or a bag, the acoustic coupling may be attenuated. Further, the frequency distribution of the received feedback signal and the acoustic output signal may be different because of a frequency dependent attenuation.
As can be seen from FIG. 1 , the mobile phone further comprises an adaptive filter 112 . The adaptive filter 112 receives the audio output signal x′(t). The adaptive filter 112 is connected with an adding unit 122 , which receives an estimated feedback signal y(t) from the adaptive filter 112 . Further, the adaptive filter 112 is connected with an analysis and control unit 114 , which also receives the estimated feedback signal y(t). This means that the adaptive filter 112 emulates the acoustic path between the audio output signal x′(t) and an audio input signal z(t) generated by the microphone. This acoustic path also includes the acoustic properties of the loudspeaker 110 and of the microphone 120 .
The audio input signal z(t) is indicative for the acoustical input signal captured by the microphone 120 . This acoustical input signal is the sum of the feedback signal and an ambient noise signal.
As can be further seen from FIG. 1 , the estimated feedback signal y(t) is fed to a negative input of the adding unit 122 . A positive input of the adding unit 122 is fed with the audio input signal z(t). The adding unit 122 calculates the difference between the audio input signal z(t) and the estimated feedback signal y(t). Therefore, the adding unit 122 acts as a subtraction unit. The difference between the audio input signal z(t) and the estimated feedback signal y(t) is a residual signal r(t), which contains the sum of the ambient noise and the remaining feedback signal not modeled by the adaptive filter.
According to the embodiment described here the mobile phone 100 further comprises a sensor device 140 . The sensor device 140 generates a sensor signal q(t), which is fed to the analysis and control unit 114 .
Descriptive speaking, FIG. 1 depicts an example of a possible implementation of the invention applied for ambient ringtone playback signal (i.e. the audio output signal x′(t)) of a mobile phone 100 . In this embodiment the relation between the playback signal x′(t) and the captured microphone signal z(t) is estimated using the adaptive filter 112 . The resulting estimated feedback signal y(t), the residual signal r(t) and the filter coefficients of the adaptive filter 112 are used for measuring changes and disturbances introduced by the acoustic properties of the environment of the mobile phone 100 . Details of this embodiment are described in the following with reference to FIG. 2 .
FIG. 2 shows a block diagram of the operation of the audio device 100 . In the described embodiment the relation between the audio output signal x′(t) representing the playback signal and the audio input signal z(t) representing the captured microphone signal is estimated by means of an adaptive filter. The resulting estimated feedback signal, the residual signal r(t) and the filter coefficients of the adaptive filter are used for measuring changes and disturbances introduced by the acoustic properties of the environment. In the following the operation of each block will be described consecutively.
Block 212 : Adaptive Filtering
According to the embodiment described here the adaptive filtering procedure is carried out by means of an acoustic echo canceller adaptive filter such as for instance a normalized least mean square adaptive filter. The adaptive filter has as inputs (a) the audio output signal respectively the ringtone signal x′(t) which is played through the loudspeaker of the mobile phone, and (b) the audio input signal respectively the captured microphone signal z(t). The adaptive filter models the electro-mechanical acoustic echo path between the microphone signal z(t) and the reference signal x′(t). The outputs of the adaptive filter are the feedback respectively the echo estimate y(t) and the residual signal r(t). These outputs are used by the block 212 a and the block 212 b for a time and frequency analysis to measure the feedback reduction performance (the ratio between the determined feedback signal and the residual signal) of the adaptive filter to analyze the disturbance introduced by the ambient noise. The corresponding coefficients w t [k] of the adaptive filter, which represent the estimated feedback path, are used by block 212 c for monitoring the dynamic behavior of the acoustical feedback path of the mobile phone in its environment. Thereby, k is the number of the respective filter coefficient.
Block 212 a : Frequency-Domain Analysis
The block 212 a performs a time-to-frequency transformation, e.g. a Discrete Fourier Transform, on the signal y(t) and r(t) in order to analysis the frequency content of the signals. Thereby, the respective signals Y t (f) and R t (f) are generated. The output signals of the time-to-frequency transformation are used in block 214 to analyze the feedback reduction performance of the adaptive filter.
Block 212 b : Time-Domain Analysis
The block 212 b performs a broadband power calculation on the signal x′(t) as described by the following equation (1):
P
x
(
t
)
=
∑
t
1
t
2
x
′
(
t
)
2
(
1
)
This power P X (t) is compared to a threshold P x — Threshold in order to select the desired parts of the ringtone as described in equation (2) for measuring the performance of the adaptive filter.
Desired — X _Signal( t )=( P x ( t )> P x — Threshold ) (2)
Applying equation (2) can be understood as a ringtone power detection. Preferably, the threshold P X — Threshold is to be tuned to the acoustics of the mobile phone.
Block 212 c : Adaptive Filter Coefficient Analysis
This block 212 c performs the analysis on the adaptive filter coefficient w t [k] to monitor the dynamic behavior of the acoustical feedback path of the mobile phone in its environment. Two different measures can be calculated:
A) The normalized Euclidian distance Δ w (t) of the filter coefficient over time, calculated according to equation (3).
Δ
w
(
t
)
=
(
∑
0
N
(
w
t
[
k
]
-
w
t
-
1
[
k
]
)
2
∑
0
N
(
w
t
[
k
]
)
2
)
(
3
)
B) The sum of the filter coefficients Sum Coeff(t), calculated according to equation (4). Thereby the state of the adaptive filter is calculated.
SumCoeff
(
t
)
=
∑
0
N
(
w
t
[
k
]
)
2
(
4
)
The value of the normalized Euclidian distance Δ w (t) is low if the mobile phone is in a steady state. If the value of Δ w (t) is higher than a certain threshold Δ Threshold , this means that the adaptive filter is adapting to a new environment. This change of environment is called a path change, for example caused by a hand being near the mobile phone, or the mobile phone being moved from an initial location to a new location, etc.
By means of the following equation (5) a divergence of the adaptive filter can be detected.
AdaptiveFilterDiverged( t )=(Δ w ( t )>Δ Threshold ) (5)
Initially the adaptive filter needs to adapt to the environment. The convergence of the adaptive filter can be detected by applying the following equation (6):
AdaptiveFilterConverged( t )=(Δ w ( t )<Δ Threshold ) (6)
The value of Sum Coeff(t) is compared to a reference value Sum Coeff Reference .
This reference value represents the acoustical coupling when the mobile phone is lying in an open environment on a desk. The reference value Sum Coeff Reference threshold depends on the acoustics of the device.
If the value Sum Coeff(t) differs by more than a certain percentage Δ Sum Coeff compared to the reference value Sum Coeff Reference , it can be assumed that the mobile phone is located in a closed environment causing the acoustical coupling to be higher or lower. According to the embodiment described here this check is done for two different time intervals, an initial time period [T SumCoeff1 : T Sum Coeff 2 ] after convergence of the adaptive filter and the consecutive time period [T SumCoeff2 : ∞] as shown in the following equation (7) and the following equation (8). The value T SumCoeff1 is equal to the moment in that the adaptive filter has initially converged (value of AdaptiveFilterConverged(t) changing from 0 to 1). In other words, equation (7) represents a detector for the initial acoustical coupling state of the adaptive filter and equation (8) represents a detector for the modified acoustical coupling state of the adaptive filter.
∀ t ∈ [ T SumCoeff 1 : T SumCoeff 2 ] , ( 7 ) AdaptiveFilterInitialState ( t ) = { 0 ( SumCoeff ( t ) < ( 1 - Δ SumCoeff ) × SumCoeff Reference ) 2 ( SumCoeff ( t ) > ( 1 + Δ SumCoeff ) × SumCoeff Reference ) 1 otherwise ∀ t ∈ [ T SumCoeff 2 : ∞ [ , ( 8 ) AdaptiveFilterModifiedState ( t ) = { 0 ( SumCoeff ( t ) < ( 1 - Δ SumCoeff ) × SumCoeff Reference ) 2 ( SumCoeff ( t ) > ( 1 + Δ SumCoeff ) × SumCoeff Reference ) 1 otherwise
Block 214 : Ratio Calculation and Verification
The raw performance RatioEcho(t)) of the adaptive filter is measured by comparing the power of Y t (f) and R t (f) for certain frequency bins. Equation (9) is used to calculate the performance of the adaptive filter.
RatioEcho
(
t
)
=
(
∑
f
1
f
2
Y
t
(
f
)
2
∑
f
1
f
2
R
t
(
f
)
2
)
(
9
)
A “filtered” performance RatioEchoFilt(t) of the adaptive filter is calculated depending on the positive detection in block 212 b according to equation (2).
This “filtered” performance RatioEchoFilt(t) of the adaptive filter is compared to a performance threshold RatioEcho Threshold as described in equation (10). This threshold depends on the acoustics of the mobile phone and on the desired amount volume increase to be applied to x(t). In other words, equation (10) is used to detect a poor performance of the adaptive filter.
PoorPerformance( t )=(RatioEchoFilt<RatioEcho Threshold ) (10)
The results of this detector are used to calculate an adequate volume change in block 211 . The performance can be calculated for several frequency bands in order to obtain more information about the performance of the adaptive filter in the different frequency bands. This information can then be used to equalize the signal x(t) to enhance the audibility in the noisy environment.
Block 211 : Gain and Frequency Calculation and Application
This block 211 calculates the gain, compression and/or the equalization, basically any filtering that needs to be applied to the original audio signal x(t) to enhance the loudness of ringtone with respect to its environment. This calculation depends on the detection results of block 214 and block 212 c . The following describes a possible gain function implementation:
For every period of time T GainAnalysis after convergence of the adaptive filter (equation 6), if a poor performance of the adaptive filter has been detected by the block 212 c (equation 10), the gain will be increased with a certain value G Increase .
The value G Increase is depending on the value of AdaptiveFilterInitialState(t). If the value AdaptiveFilterInitialState(t) is equal to 0, indicating that the ringtone playback is muffled, a higher increase value G IncreaseHigh is used.
If the value of AdaptiveFilterInitialState(t) or AdaptiveFilterModifiedState(t) is equal to 2 after T SumCoeff2 , the mobile phone is assumed to be located in a closed environment. In this case the gain is increased to a certain high gain value to compensate the fact that the ringtone is muffled as well.
If a path change or a change in state of the adaptive filter has been detected, the gain increase is stopped for a certain period of time. Furthermore, if the value of AdaptiveFilterModifiedState(t) is different from 1 after T SumCoeff2 , this indicates that the mobile phone has been picked-up by a user. In this case, the gain is lowered to its initial value.
Block 212 : Sensor Data Analysis
This block 212 , which is optional, performs an analysis of other sensor data provided by a sensor signal q(t) in order to give additional information about the environment of the device, which can enhance the detection. As has already been mentioned above, the sensor signal q(t) may be provided by any context sensor, which is capable of detecting a measurable variable of the mobile phone and/or of the environment of the mobile phone. The additional consideration of the sensor signal q(t) may provide the advantage, that the audio output signal can be adapted very precisely towards its desired behavior depending on the environmental acoustic conditions.
The sensor providing the sensor signal q(t) may be a light sensitive sensor, a motion sensor, an acceleration sensor and/or a proximity sensor. Preferably, the sensor is a built-in sensor of the mobile phone.
Apart from the mobile phone application of the invention described above the audio output signal adaptation procedure described in this application may also be used for other applications. The described acoustical monitor and detection mechanism based on analyzing the dynamics in a determined relation between the audio playback signal and the captured microphone signal can generally be used to steer any playback audio device and its playback towards a desired behavior. Specifically, the described audio output signal adaptation can be used for instance for an automatic ambient noise adaptive speech enhancement. Further, an automatic ambient noise adaptive playback on any audio devices may be implemented, on which direct noise level measurements from the captured microphone signal are not possible because the ambient noise is masked by the echo from the audio playback. Furthermore, the described mechanism can be used for an acoustical detector using the loudspeaker and the microphone signal to steer the audio device and the audio playback towards its desired behavior in response to a change in or detection of a certain acoustical environment of the audio device, e.g. a proximity detector.
It should be noted that the term “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.
In order to recapitulate the above described embodiment of the present invention one can state:
In this application there is described an acoustical monitor and detection system to steer the adaptation or enhancement of acoustic output signals of an audio device depending on the acoustic characteristics of the environment of the audio device including adaptation of other functionality of the audio device. The audio device comprises an acoustic output device such as for instance a loudspeaker and an acoustic input device such as for instance a microphone. The acoustic properties of the environment influence a relation or a mapping between the audio output signal producing the acoustic output signal and the audio input signal being captured by the acoustic input device. A change or a disturbance in the environment of the audio device causes a change or a disturbance in a determined or estimated relation between the audio output signal and the captured audio input signal. By measuring and monitoring this relation or derivative of these signals and its dynamics, the audio device can identify changes or disturbances in the environment of the with respect to reference situations. Thereby, an acoustical detection mechanism is defined, which is used to steer the audio device and in particular the audio output signal towards a desired behavior depending on the acoustic environmental conditions.
More specific, this invention allows adaptation of ringtone or audio playback on mobile audio devices depending on the level of the environmental background noise, which is not possible by direct noise measurement techniques due to a high acoustical coupling between the acoustic output device and the acoustic input device. In addition, by evaluating the above described relation between the audio output signal and the captured audio input signal a detection mechanism can be established, which can find out whether the mobile audio device is covered or is located in a closed environment like a pocket or a bag during a ringtone playback representing the above mentioned acoustic output signal. This situation requires as well an adjustment of the ringtone volume and equalization accordingly, so that the ringtone can be heard. In addition, by evaluating the above described relation between the audio output signal and the captured audio input signal an acoustic detection mechanism may be provided for detecting a pick-up of the mobile audio device so that the ringtone playback level can be reduced back to a soft, comfortable level or mute when answering the call has already started.
REFERENCE NUMERALS
100 audio device/mobile phone
110 acoustic output device/loudspeaker
111 loudness enhancement unit
112 adaptive filter
114 analysis and control unit
120 acoustic input device/microphone
122 adding unit
140 sensor device
r(t) residual signal
q(t) sensor signal
x(t) original audio signal
x′(t) audio output signal
y(t) estimated feedback signal
z(t) audio input signal
w t [k] adaptive filter coefficients
211 Gain and Frequency Calculation and application
212 Adaptive Filtering
212 a Frequency Analysis
212 b Time Analysis
212 c Adaptive Filter Coefficients Analysis
214 Ratio Calculation and Verification
242 Sensor Data Analysis
r(t) residual signal
R t (f) fourier transform of r(t)
q(t) sensor signal
x(t) original audio signal
x′(t) audio output signal
y(t) estimated feedback signal
Y t (f) fourier transform of y(t)
z(t) audio input signal
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It is described a method for controlling an adaptation of a behavior of an audio device ( 100 ) to a current acoustic environmental condition. The method comprises (a) monitoring an audio output signal (x(t), x′(t)) being provided to an acoustic output device ( 110 ) of the audio device ( 100 ) for outputting an acoustic output signal, (b) measuring an audio input signal (z(t)) being provided by an acoustic input device ( 120 ) of the audio device ( 100 ), wherein the audio input signal (z(t)) is indicative for a feedback portion of the acoustic output signal and for the current acoustic environmental condition, (c) determining a relation between the audio output signal (x′(t)) and the audio input signal (z(t)) and (d) adapting the behavior of the audio device ( 100 ) based on the determined relation. Further, it is described a data processor, a computer-readable medium and an audio device, which are adapted to control and/or to carry out the above mentioned method for controlling an adaptation of the behavior of an audio device ( 100 ) to a current acoustic environmental condition.
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FIELD OF INVENTION
[0001] This invention entails a data transport system in a telecommunication network, using radio frequency subcarriers.
DESCRIPTION OF THE STATE OF THE ART
[0002] Since the early 90's, a large growth in telecommunication services has been experienced due to an intense and increasing use of Internet Protocol (IP)-based networks. Starting from dedicated and specific applications in the 70's, restricted to the scientific community, 64 kbps connections have become widely used on account of access availability, transport and a large number of microcomputer users. This stage, which can be considered the “first Internet wave”, had such an intense expansion that, in the mid-90's, data transport networks in the United States began to present occupation rates incompatible with the Quality of Service (QoS) required by American Internet server subscribers, due to line busy signals and long delays in Internet applications.
[0003] Multiplex technology by wavelength division (WDM) has proved to be extremely effective and of very fast installation, dispensing with operations in the infrastructure of fiber optics already installed. The improved operation of data transport networks has been reflected immediately in Internet applications, allowing the immediate acceptance of new subscribers.
[0004] By means of the subscriber incorporation of a second and a third home telephone line installation of WDM systems has begun in metropolitan optical networks. The number of optical carriers, which was initially limited to four units, has reached values of eight, sixteen, thirty-two and sixty-four units. Internet providers then started to offer multimedia services, e-commerce, e-business, web games, among others, by means of an Integrated Services Digital Network (RDSI-ISDN) and, more recently, ADSL (Asymmetrical Digital Subscriber Line).
[0005] Another trend identified was the voice services transport over IP (Voice over IP—VoIP) by the Internet services providers (ISP), as an alternative to traditional telephone services. IP Providers based themselves on the high reliability of the optical means and abandoned the stringent telephone hierarchies and the protection and restoration schemes used till then. In this way, IP applications on DWDM (Dense Wavelength Division Multiplexer) and alternatives such as Packet-over-Sonet (PoS) have emerged, which are based on routers. A market segment has been created, wherein the Quality of Service exhibited by ATM (Asynchronous Transfer Mode) switches and the protection and restoration patterns of the telephone operators ceased to be used, in exchange for traffic without QoS, not protected and without a delivery guarantee, but with significantly lower costs.
[0006] The trend towards the use of systems with high rates, which associate IP over DWDM, is becoming intense, although, as indicated previously, without protection, restoration or QoS.
[0007] In fact, it can be noted that there is a scenario of competition between telephone operators and Internet providers, wherein the possibility of developing networks with the intelligence functions implemented on the physical optical layer can significantly alter the applications involving the current telecommunications networks.
[0008] In order to clarify what is meant by a physical layer, with the aim of creating connectivity standards for the interlinking of computational systems, the OSI model was created (Open System Interconnect).
[0009] General aspects of this connectivity were divided into seven functional layers in such a way as to try to facilitate the understanding of a communication process between the programs of a computer network. A brief summary follows describing what each layer is.
[0010] The physical layer covers the hardware specifications used in the network, which include mechanical, electrical and physical aspects. Another layer is that of enlace, which is restricted to only two network nodes. The protocols in this layer aim to make the data sent from one computer to another interconnected with it arrive in a correct form and without damage or loss. In the network layer, its protocols deal with routing the messages in the network according to routing algorithms, addressing and stream control disciplines. In a transport layer, the transport protocols have an “end to end” view of the communication process, guaranteeing that data sent from the origin will arrive at its destination, and for this it uses mechanisms such as stream control, error correction and others. A session layer deals with the “dialogue” between the programs that run in a network while the presentation layer deals with the syntax and semantics of these programs' data, e.g. the cryptography. The last layer is that of application, which deals strictly with the definition of the application protocols themselves.
[0011] U.S. Pat. No. 5,854,699 describes a data transport system, the addressing of which is made by an optical filter /λT, and subcarriers to supply the control information. This patent aims at dissociating traffic velocity from control signal velocity, as used in a LAN. There was a great concern with the high rates in control signal, because of silicon state of the art technology at the time this patent was filed. The control information is node identification, transmission channel identification, “free/busy” status, priority, acknowledgment, broadcast/unicast, and are extracted via information demodulation techniques transported by the subcarrier. Such a modulation is straight from the laser, and a single subcarrier is used to connect the control information common to all the nodes that use it by means of a token hierarchization.
[0012] Because of the modulation need in the subcarriers, it has a high response time, so that keying packet by packet is not possible in real time.
[0013] U.S. Pat. No. 5,847,852 describes an optical network, which has several subordinate optical networks that function as transmitters and receivers. The system used in this invention is an information transport system where frequency conversion occurs and addressing is WDM/SCM. Therefore, the signal check takes place by means of the conversion, and this procedure delays receiving the information via the node destination to which it is sent.
[0014] European patent No. 550,046 A2 describes a system for routing and switching of optical packets with multiplexed header and data. The procedure comprises the use of a multiplexed carrier to contain routing information. Such a header is transmitted on the same optical carrier, but at a lower velocity than that of the data packets. This makes the receivers process and detect such information by means of a lower cost receiver. It is possible to lessen the costs of the receiver, although what happens in the systems of the previously mentioned patents also takes place here. The information receiving time via the destination node still remains excessively long.
[0015] The great majority of current data transport systems transport data, which until it arrives at its destination, are open at each node along the path. This makes the information take a long time to arrive at its true destination.
OBJECTS OF THE INVENTION
[0016] It is an object of this invention to reduce time spent in data addressing, protection and restoration.
[0017] It is an object of this invention to dispense with optical-electric and electric-optical conversions in the intermediate nodes during the transmission of the information held in a data packet.
[0018] It is another object of this invention to use intelligence functions of the physical layer without altering protocols.
[0019] It is still another object of this invention to expand the bandpass and use the intervals aimed at headers.
[0020] It is still another object of this invention to avoid opening and reading each packet to know its destination in a data transport system.
[0021] It is still another object of this invention to simplify the management of a data network—TMN (Telecommunications Management Network).
[0022] It is still another object of this invention to guarantee the data packet delivery, which is to be sent in a data transport system.
[0023] It is another object of this invention to allow the addressing and crosslinking directly on the optical layer.
[0024] It is another object of this invention to operate without altering the original frame signaling.
[0025] The objectives described above are achieved by means of a data transport system, which will be presented in further detail below.
SUMMARY OF THE INVENTION
[0026] According to the description of this invention, a data transport system and method and its components are as follows:
[0027] The data transport system of this invention comprises:
[0028] A data packet emission device, which acts on the physical layer of a data transmission network, and has a device to attach information to data packets in the form of a tag. A device for reading the information on the data packet tag is also provided. The tag is external to said data packet, unmodulated and contains information indicating the address of origin and the destination of the data packet. The tag comprises at least one unmodulated RF subcarrier. The number of addresses referred to is 2n−1, n being the number of subcarriers. The system has an additional subcarrier to indicate the existence of a data packet to be transmitted.
[0029] The device for reading the information provided in the data packet tag detects the presence/absence of RF subcarriers and transforms them into a binary sequence. The data transmission is a telecommunications optical network. The data packet emission device comprises a Gigabit IP router, a microwave frequency generator, an RF logic switch, and a differential Mach-Zehnder modulator. The device for reading the information provided in the data packet tag comprises dielectric resonator filters, microwave detectors, a Gigabit detection switch and a Gigabit IP router.
[0030] The data transport process comprises: creating an information code like an external tag; attaching the information code like an external tag to a data packet; non-modulation of the tag which comprises the information code; sending the data packet with the tag to its destination; and decoding the tag information code during the data packet path, including to its destination, in a data transport network.
[0031] The tag information decoding of the data packet is effected by means of detecting the presence/absence of at least one unmodulated RF subcarrier. Then the information transposition for the information to a digital sequence indicating at least one destination address of the referred data packet takes place. The binary sequence identification is a function of a logic address. The attachment of the information code is accomplished in the manner of an external tag on a data packet. The data packet presence indication to be sent is attained by means of an RF subcarrier.
[0032] The information of the subcarrier constellation comprises destination/origin nodes indication (avoiding packet reading in intermediate nodes), the presence/absence of the packet in each network node, power levels—which are used for protection/restoration and simplification of the network TMN management.
[0033] The data transport system is passible for use in establishing an optical VPN (Virtual Private Network), which is selected and dedicated according to any telecommunications operator planning. In this data transport system, the subcarriers themselves carry information that will help in making decisions on protection and restoration and management agility in a telecommunications network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] For a better understanding of this invention, reference is made to the drawings/figures in which:
[0035] [0035]FIG. 1 shows a graphic in the frequency domain, a number of RF subcarriers are introduced above the payload spectrum;
[0036] [0036]FIG. 2 shows schematically how the RF subcarriers are electrically generated and next introduced in the optical spectrum;
[0037] [0037]FIG. 3 shows a complete schematic diagram of a node receiver, using subcarriers for protection and addressing;
[0038] [0038]FIG. 4 shows a block diagram of a generic optical network node when using electrical subcarriers for protection, restoration and addressing functions;
[0039] [0039]FIG. 5 shows a Microwave Carrier Generator, used in the system of FIG. 2;
[0040] [0040]FIG. 6 shows a Logical RF switch, used in the system of FIG. 2;
[0041] [0041]FIG. 7 shows an RF passive combiner, used in the system of FIG. 2;
[0042] [0042]FIG. 8 shows a dielectric-resonator (DR) filter, used in the system of FIG. 3: (a) dielectric-resonator, (b) dielectric-resonator physics implementation, and (c) graphic results of a dielectric-resonator-filter with different bands;
[0043] [0043]FIG. 9 shows a crystal quadratic RF detector, used in the system of FIG. 3;
[0044] [0044]FIG. 10 shows a gigabit detection switch, used in the system of FIG. 3: (a) implemented with NAND logical gates, and (b) implemented with AND and NAND logical gates;
[0045] [0045]FIG. 11 shows a block diagram of IP Gigabit Router.
DETAILED DESCRIPTION
[0046] The explosive traffic growth due to the increase in Internet utilization is well known. The Optical WDM technology has became the preferred solution for coping with the exponential increase and demand for the utilization of ever greater bandwidths.
[0047] Optical WDM networks call for a very complex management array. Usually, there is a need to convert the optical data stream—in each network node—from the optical to the electric domain and also to open the data packets, in order to investigate whether or not the packets are aimed at the focused node. These operations are time-consuming (jeopardizing real-time voice and video transmissions) and also quite demanding with respect to equipment needs.
[0048] Any further step addressed to decreasing management array cost and/or decrease management processing time is worthwhile considering.
[0049] In this invention, restoration & protection, together with node routing, will be performed at the physical layer level. The mentioned protection may be also used for achieving protected IP transmissions—a procedure that it is not very usual. Rather, it is more a routine to convey IP—unprotected—over the so-called PoS (Packet over Sonet), where the Sonet protection bits have been removed.
[0050] The above-mentioned restoration, protection and addressing operations will be performed by fast electronic circuitry in a very straightforward way or, in other words: notably fast when the software is used. In order to do so, when a node launches a data packet 1 , a number of RF sub-carriers 2 are introduced above the payload frequency spectrum. The electrical spectrum will then look as depicted below, in FIG. 1.
[0051] In FIG. 1, a number of RF subcarriers 2 are introduced above the payload spectrum. Half of them identify the destination node 2 . 1 , the other half identifies the source 2 . 2 : an extra one 2 . 3 indicates that the circuit is on, to avoid misinterpretation of any link with a fault condition.
[0052] Next, while the packets 1 are received at the correct node, suitable optoelectronic circuitry will process these subcarriers 2 in order to offer protection & restoration, together with routing operations.
[0053] [0053]FIG. 2 shows a transmitter device 36 comprising an IP Router 4 associated with an RF sub-system. At the transmitter, the Microwave Carrier Generator 3 electrically generates nine RF/microwave subcarriers; one of them (f 9 ) will be introduced whenever a node emits a data packet. The subcarriers, f 1 , f 2 , f 3 and f 4 generated through the Source Generator 37 identify the source node, while the others four f 5 , f 6 , f 7 and f 8 generated through the Destination Generator 38 identify the destination node.
[0054] A logical RF Switch 5 uses data from IP Router 4 to compose a subset of the subcarrier related with the destination node 2 . 1 and another Logical RF Switch 5 will compose a subset of the subcarrier related with the emitting (origin) node 2 . 2 , in the same manner. The generated subcarriers will be combined through the RF Passive Combiner 7 and next introduced in the optical spectrum by means of a differential Mach-Zehnder (MZI) 6 . The extra subcarrier (f 9 ), which controls the data packet existence, is introduced in the optical spectrum through the same Mach-Zehnder (MZI) differential 6 .
[0055] The number of subcarriers and their respective frequency allocation is to be settled by the network designer. For doing so, the strategic approach is the following:
[0056] (a) A subset comprising half of the subcarrier set is related with the emitting (origin) node;
[0057] (b) The other half of the subcarrier set is related with the receiving (destination) node;
[0058] (c) The specific subcarrier frequency positions are such that each subcarrier subset describes—unequivocally—a unique emitting node and a unique receiving node;
[0059] (d) Furthermore, there is an extra subcarrier 2 . 3 , which indicates that the connection is “on”. Without this carrier, an idle traffic condition could be misinterpreted as a fault, as will be seen below.
[0060] The total number of nodes is 2N−1, where N is the number of subcarriers used to form the addressing code. In principle, the subcarriers remain unmodulated. If they were modulated, their number might be substantially reduced. However, their action would only be effective after demodulating the information they carry. This latter operation is much slower than a simple detection of their presence. Consequently, if network management speed is the prime objective, CW (continuous wave) subcarriers are preferred.
[0061] According to FIG. 3, the protection and restoration action using the subcarriers is performed according to the following steps:
[0062] (a) For any receiving node there is a particular subcarrier subset combination related with the referred node address (called “bits b”);
[0063] (b) A sample of the subcarrier subset related to destination node function is detected, filtered and sent to logical gates 15 ; The first two actions are performed by the destination detector 26 and filter 14 , respectively;
[0064] (c) If a positive logical sign is obtained at the Gigabit Detection Switch 15 output, it means that the arriving data packet is designated to this node. Packet processing procedures are then activated;
[0065] (d) If the above-mentioned positive sign is absent, either the data packet is not aiming at the referred node, or the link is faulty;
[0066] (e) To solve the above question, there is an additional mechanism, traffic detector 28 , to detect if either the traffic indicator subcarrier 2 . 3 is absent (failure situation), or if it is present and/or still, at least one subcarrier is present (non-failure situation, momentarily with no traffic, or data seeking a different node, respectively).
[0067] When a failure situation, as described above, occurs, there will be a commutation, at the first Optical Switch 9 , from the working (W) optical channel to that of protection (P).
[0068] Previously, it was mentioned that—in each node—the subcarrier subset that is related to the node destination function 2 . 1 is detected locally and electrically processed.
[0069] This processing comprises the use of narrowband filters 14 : each one tuned to one of the subcarrier frequencies.
[0070] [0070]FIG. 3 shows a complete schematic diagram of the receiver circuitry 8 in each node, which is able to supervise the RF subcarriers 2 . The optical signal is divided into three parcels by a splitter 29 . The first one, (80%), follows transporting through an optical delay 30 . The second (10%) is used by the system to verify the optical signal level received through a power level monitor 10 . The third is converted to the electrical domain by a photodetector 11 .
[0071] Subsequently, signal splitters 12 and RF amplifiers 13 will route the above-mentioned signal to a narrowband filter array 14 . In FIG. 3, this array is illustrated by an 8-dielectric-resonator-filter array. The array is composed of two sub-arrays: The first sub-array 14 comprises filters 1 , 2 , 3 and 4 , which deals with the subcarriers related with the origin node. The second sub-array 14 (filters 5 , 6 , 7 and 8 ) deals with the subcarriers related with the destination node. After detection 26 , each sub-array is able to furnish binary codes describing the origin and destination nodes, respectively. The origin binary code is later converted by the decode unit 31 , while the destination binary code is being analyzed by the Gigabit Detection Switch 15 and compared with the particular bits “b” sequence (b 5 b 6 b 7 b 8 ) implemented in each node.
[0072] Additionally, the traffic indicator subcarrier f 9 (which is always on) is filtered 14 and detected 28 by the receiving node. This furnishes an indication of transmission of data packet 1 , even during an idle traffic condition. In this way, there will always exist the possibility of power monitoring. This latter operation is necessary for choosing between receiving either W (Working) fiber channel or P (Protection) fiber channel. After the W or P channels decision, there is binary code analysis related with the destination node. In order to do so, component 33 enables the identification bits “b”.
[0073] In case the destination node is the one that is being focused, a second decision circuit 27 will connect the second optical switch 9 to the pertinent node router 4 (Drop Switch Router) in FIG. 3.
[0074] Meanwhile, the RF subcarriers 2 will be “on” during a whole SONET frame, if this is the case. Observe the optical delay element 30 , providing correct timing with respect to the decision circuits 34 and the second optical switch 9 .
[0075] Concerning the concatenated action of the transmitter, together with the receiver, FIG. 4 is furnishing a block diagram of a complete generic node. There, using a schematic diagram becomes clear what has been previously described in FIG. 2 and FIG. 3.
[0076] Microwave Carrier Generator 3
[0077] The main function of the Microwave Carrier Generator 3 , described in FIG. 2, is to generate the RF subcarriers 2 . With reference to FIG. 5, which shows a detailed Microwave Carrier Generator, a Crystal Oscillator 16 in 100 MHz, combined with frequency multipliers 17 , narrow-band filters 18 and amplifiers 13 , generates eight different frequencies. These eight frequencies are separated from each other by 100 MHz, and will be used to form the addressing code. The subcarriers, 1.9, 2.0, 2.1 and 2.2 GHz identify the source node addressing, while the other four 2.3, 2.4, 2.5 and 2.6 identify the destination node address. It is worth mentioning that these numbers are just an example and other frequency ranges can also be used.
[0078] Logical RF Switch 5
[0079] The Logical RF Switch 5 , detailed in FIG. 6, is responsible for combining the RF subcarriers in order to form the addressing codes 2 . 1 and 2 . 2 . Each network node has a fixed address, which is represented by a binary code. The “on/off” RF subcarriers 2 , indicating bits “ 1 / 0 ”, respectively, represent this code.
[0080] To generate the right combination, a logical intelligence 39 is used. This intelligence will command the RF switches 40 enabling or not the subcarrier 2 transmission and then forming an addressing code.
[0081] RF Passive Combiner 7
[0082] The previously generated subcarriers 2 form a code that indicates the addressing of origin node 2 . 2 that launch the data and the addressing of the destination node 2 . 1 at which this data is aimed. An RF Passive Combiner 7 , shown in FIG. 7, combines the four origin subcarriers and the four destination subcarriers, to later be amplified 13 and then added to the optical spectrum by means of a Mach-Zehnder device 6 .
[0083] Dielectric-Resonator (DR) Filter 14
[0084] As in applied case subcarriers 2 are spaced from each other just in 5%, and since this distance is too small for the micro-strip or strip-line filters to be used, dielectric resonator filters (DR Filters) 14 were chosen. Dielectric cavities with very high εr values (for instance: εr=40, εr=80, . . . ) have been used in coupled lines structures, in association with the possible tuning of the cavity TE01δ mode, according to FIG. 8.
[0085] Accordingly, filters in microwave frequencies with low insertion loss (<1 dB) e narrow tuning—due to a very high Qloaded value presented in resonators—can easily be constructed and at low cost. Tuning is made by metallic or dielectric screws, which descend on to the resonator.
[0086] Detectors 20
[0087] The detectors 20 will transform the RF subcarriers 2 into a binary number that indicates an addressing code. The presence or not of these subcarriers 2 corresponds to bits “ 1 ” or “ 0 ”, respectively.
[0088] The crystal microwave detector 20 works like an RF signal rectifier, taking the amplitude of the microwave signal off. This type of configuration can be dimensioned for rising time less than 10 picoseconds and it can be interfaced with Emitter Coupled Logic—ECL or Source Coupled FET Logic—SCFL.
[0089] Gigabit Detection Switch 15
[0090] The main function of this block is to compare the binary code received—through bits “a”, with the local addressing binary code (bits “b”), in order to check if the node is intended to be the destination of the transmitted data packet 1 .
[0091] The Gigabit Detection Switch 15 is implemented using ultra-fast logical gates like AND or NAND, depending on the local node addressing code (bits “b”). FIG. 10 shows examples of this implementation.
[0092] In conclusion, based on these examples, AND gates are used when bit “b=0”, otherwise NAND gates will be used (“b=1”). It takes place like this in order to always take logical value results as “1” when the bit sequence “a 5 a 6 a 7 a 8 ” is equivalent to bits “b 5 b 6 b 7 b 8 ” or logical value results as “0” when these bits do not match. The examples show that when the binary code received (bits “a”) does not match with the local addressing code (bits “b”), it will generate a logical value “0” as a result, indicating that the data packet 1 is not aimed at this specific node. But if the codes match (bits “a”=bits “b”) the Switch 15 will indicate the logical value “1”, indicating that this specific node corresponds to the destination of the data packet 1 .
[0093] IP Gigabit Router 4
[0094] This block can be considered as an additional unit, which selects and implements functions in order to synchronize the system proposed in this invention. This unit has at least four outgoing signals that will be applied at the transmission module. The two first indicate the start and stop clock time, respectively, and the third is the optical output corresponding to the data packet 1 , while the fourth provides the addressing codes.
[0095] The byte A 1 initializes the system clock and, after approximately 20 μs, the information of origin and destination addressing have already been received by the Microwave Frequency Generator 3 .
[0096] From this moment, the RF subcarriers 2 could be activated at up to 100 μs, coinciding with the payload transmission, transposed to the optic domain. In this way, each combination of destination and origin address will have a lifetime similar to its associated Frame.
[0097] Therefore, it must be understood that the system and its described component parts above are only some of the modalities and examples of situations that could occur, while the real target of the object of the invention will be defined in the claims.
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This invention refers to a data transmission system and process wherein a data packet ( 1 ) to be transmitted in a telecommunications network with a tag ( 2 ) containing destination and origin information ( 2.1, 2.2 ) of said packet ( 1 ). In each node of a packet path ( 1 ), tag ( 2 ) will be read and there will be no need to open the former. Information contained in tag ( 2 ) is constituted of a constellation of RF subcarriers ( 2 ) and its detection is accomplished by checking for absence or presence of subcarriers. The process is accomplished without needing to modulate subcarriers, whereby the checking of the information contained is accelerated.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of provisional U.S. patent application Ser. No. 60/055,194 filed on Aug. 11, 1997, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Ceramics are a general class of compounds that are the product of treating earthy raw materials with heat. Many ceramics comprise silicon and its oxides. Some of the more common ceramics are clay products, such as brick, porcelain, glass, and alumina. Ceramics are known for their heat-resistance, hardness, and strength. Metals, which are easily machined, do not retain their machined form at high temperatures. Ceramics, however, retain their shape at extremely high temperatures, but are brittle and very difficult to machine into a desired shape. Materials engineers have directed a great deal of effort into finding compositions that are easily machined into a desired shape and are stable at extremely high temperatures.
[0003] Ternary ceramic compounds such as titanium silicon carbide (Ti 3 SiC 2 ), and related “3-1-2” phase ceramics, as well as the “H-phase” ceramics have been studied and identified as meeting these requirements; that is, they are easily machineable and heat-resistant. For these reasons ternary ceramic compounds have been used to construct workpieces of varied shapes having heat-resistant properties and high strength. International Patent Application WO98/22244, published on May 28, 1998, of Barsoum et al. for “Process for Making a Dense Ceramic Workpiece” describes a process for making workpieces from these types of ceramic compounds and is herein incorporated by reference.
[0004] The application of corrosion resistant coatings to different articles in order to protect their surfaces from degradation by oxidation or chemical attack is a vastly important field of study. Much effort has been devoted to extending the useful lives of articles subject to corrosion by coating the article with a corrosion resistant composition. Coatings are also applied to substrates for protection against wear. Coatings with corrosion-resistant and wear-resistant properties are applied in many different ways. Some are applied by dipping or painting, others are applied by chemical adsorption, and still others are applied by chemical reaction. Many coatings used to provide protection to surfaces are applied by thermal spraying processes.
[0005] Thermal spray processes are a well known family of coating technologies that include detonation guns, high-velocity oxyfuel spray processes, wire-arc spraying, and both air and vacuum plasma spraying. U.S. Pat. No. 5,451,470 of Ashary et al.; U.S. Pat. No. 5,384,164 of Browning; U.S. Pat. No. 5,271,965 of Browning; U.S. Pat. No. 5,223,332 of Quets; U.S. Pat. No. 5,207,382 of Simm et al.; and U.S. Pat. No. 4,694,990 of Karlsson et al., collectively describe thermal spray processes and are herein incorporated by reference.
[0006] The types of coatings applied by these thermal spray techniques have generally been grouped into two broad categories, carbides and non-carbides. The carbides applied by thermal spray processes are generally transition-metal carbides such as tungsten carbide, chromium carbide, and cobalt-based carbides. The non-carbides applied by thermal spraying processes include iron-nickel based alloys, copper-nickel-indium alloys, metals and alloys such as aluminum, zinc, steel, bronze, and nickel, and aluminum-polyesters. Some ceramics, such as alumina and titania, which offer good wear-resistance, can be applied as coatings using the extremely high temperature (usually greater than 11,000° C.) plasma spraying technique. Yttria-stabilized zirconia (YSZ), another ceramic, is well known as a thermal barrier coating in applications subject to extremely high temperatures.
[0007] High-velocity oxyfuel spray processes are advantageous in that they provide excellent dense, adherent coatings. Also the equipment used is more portable than other thermal spray equipment. Unfortunately, the ternary ceramic compounds described above have dissociation temperatures in the general range of from about 1000° C. to about 1800° C., and most thermal spray processes, including high-velocity oxyfuel, have gas jet temperatures in excess of 2500° C.
BRIEF SUMMARY OF THE INVENTION
[0008] It has been both unexpectedly and surprisingly found, however, that the ternary ceramic compounds in accordance with the present invention can be sprayed using thermal spray processes to form adherent, corrosion-resistant, oxidation-resistant and/or wear-resistant coatings, and that the composition of the compounds remains substantially unchanged after undergoing the thermal spray process.
[0009] According to the present invention, articles are produced having a surface with a coating having corrosion-resistant, oxidation-resistant and/or wear-resistant properties, the coating comprising at least one of a ceramic compound of the general formula (I):
M 2 X 1 Z 1 (I)
[0010] wherein M is at least one transition metal, X is an element selected from the group consisting of Si, Al, Ge, Pb, Sn, Ga, P, S, In, As, Tl and Cd, and Z is a non-metal selected from the group consisting of carbon and nitrogen; and a ceramic compound of the general formula (II):
M 3 X 1 Z 2 (II)
[0011] wherein M is at least one transition metal, X is at least one of Al, Ge, and Si, and Z is at least one of carbon and nitrogen.
[0012] In accordance with the present invention, it is desirable that the coating be substantially comprised of the ceramic compounds of the general formulas (I) and/or (II), by minimizing the dissociation of the ceramic compounds during application. The ternary ceramic compounds of the general formulas (I) and/or (II) are present in the coatings of the present invention in an amount of at least about 70% by volume of the ternary ceramic compounds sprayed. Preferably, the ternary ceramic compounds of the general formulas (I) and (II) are present in the coatings of the present invention in an amount of at least about 80% by volume of the ternary ceramic compounds sprayed, and more preferably they are present in the coatings of the present invention in an amount of at least about 90% by volume of the ternary ceramic compounds sprayed.
[0013] Also, according to the present invention, articles are produced having a surface with a coating having corrosion-resistant, oxidation-resistant and/or wear-resistant properties, the coating being produced by a process comprising the steps of providing a powder of at least one of a ceramic compound of the general formula (I) as described above, and a ceramic compound of the general formula (II) as described above; and thermal spraying the powder of the at least one compound onto the surface. It is preferable that the coating is substantially comprised of the ceramic compounds of the general formulas (I) and/or (II) and the presence of dissociation products of the ceramic compounds is minimized. The minimization of dissociation of the ceramic powder particles is accomplished by controlling both the temperature of the thermal spraying device, and the length of time which the ceramic powder particles remain within the thermal spraying device, during which they are being heated.
[0014] According to another aspect of the present invention, a method is provided for coating a surface comprising the steps of providing a powder of at least one of a ceramic compound of the general formula (I) as described above, and a ceramic compound of the general formula (II) as described above; and thermal spraying the powder of the at least one compound onto the surface, whereby a coating having corrosion resistant, oxidation resistant and/or wear resistant properties results on the surface, the coating substantially comprised of ceramic compounds of the general formulas (I) and/or (II).
[0015] In a preferred embodiment of the present invention the coating is comprised of titanium silicon carbide, Ti 3 SiC 2 , and the thermal spray process utilized is a high-velocity oxyfuel spraying process. The preferred coatings in accordance with the present invention have thickness of at least about 0.002 inches, and more preferably at least about 0.005 inches.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Ceramic powders of the general formula (I) are known synonymously both as “H-phase” and “2-1-1” ceramics, signifying the molar ratio of component M to component X to component Z, or M:X:Z. Ceramics of this type and their syntheses are disclosed and described in detail in International Patent Application WO97/27965, published on Aug. 7, 1997, of Barsoum et al. for “Synthesis of H-phase Products”, and its disclosures are herein incorporated by reference.
[0017] Ceramic powders of the general formula (II) are known as “3-1-2” ceramics, signifying the molar ratio of component M to component X to component Z, or M:X:Z. Ceramics of this type and their syntheses are disclosed and described in detail in International Patent Application WO97/18162, published on May 22, 1997, of Barsoum et al. for “Synthesis of 312 Phases and Composites Thereof”, and its disclosures are herein incorporated by reference.
[0018] The ceramics used in the present invention can be powdered in a conventional manner, for example, by mechanical crushing. The powders used in the present invention should have a maximum particle size of about 100 μm, and a minimum particle size of about 5 μm. In a more preferred embodiment of the present invention, the powders have a maximum particle size of about 65 μm, and a minimum particle size of about 7 μm, and in a most preferred embodiment, the powders have a maximum particle size of about 45 μm, and a minimum particle size of about 10 μm. Particle size determination can be accomplished by any conventional method, such as for example, mesh screening or laser scattering.
[0019] The preferred ceramic compounds to be used in accordance with the present invention are those corresponding to general formula (II), the “3-1-2” phase ceramics. The most preferred ceramic is titanium silicon carbide, Ti 3 SiC 2 .
[0020] The coating comprising a ceramic as described above should have a thickness of at least about 0.002 inches, preferably at least about 0.005 inches, and more preferably at least about 0.008 inches. The thickness of the coating should be such that complete coverage of the surface is obtained. Coverage that is not complete, or near complete can hinder the corrosion-resistant properties of the coating. Additionally, the above mentioned approximate minimum coating thickness is necessary to maintain the integrity or cohesion of the coating. The approximate maximum thickness of the coating may be determined by the intended end use of the article being coated, although the approximate maximum thickness of the coating should not be so great that residual stresses in the coating itself impair its properties. The possibility that contraction of the ceramic coating upon cooling will create cracks in the coating increases as the outer surface of the coating moves farther and farther away from the surface being coated.
[0021] The coatings in accordance with the present invention have limited porosity. The porosity of the coatings is approximately 30% or less.
[0022] Additional materials or powders can be further mixed with the ternary ceramic powders being sprayed onto a surface in accordance with the present invention. Examples of such additional materials and powders are carbides, silicides, nitrides, oxides, other thermally sprayable compounds, and mixtures thereof.
[0023] The coatings in accordance with the present invention are useful for providing corrosion-resistance and/or wear-resistance to the surfaces of articles, both metal and non-metal (e.g., other ceramics), such as those used in the manufacture of chemical plant equipment including without limitation, pressure vessels, reactors, storage tanks, pipe lines, valves, heat exchangers, and the like.
[0024] In accordance with the present invention, a coating comprising a ceramic as described above can be applied to the surface of an article by a thermal spray process. The method of coating a surface with a coating comprised of a ceramic, as described above, involves the heating of a stream of ceramic particles and accelerating the particles through a nozzle, aimed at the surface to be coated. Upon impact the heated particles impact against the surface, spreading out and adhering to the surface. By using a thermal spray process, a dense, thick, contiguous coating of ceramic can be obtained according to the present invention. Thermal spraying techniques of other materials have been used to apply coatings to various substrates, and these thermal spraying processes may be adapted to the application of the coatings of the present invention to substrates on which a corrosion-resistant, oxidation-resistant and/or wear-resistant coating is desired.
[0025] The temperature of the gas jet exiting a thermal spray gun is usually in excess of at least about 2000° C., and more usually in excess of 2500° C. The dissociation temperatures of the ceramic compounds used in accordance with the present invention are between about 1000° C. and about 1800° C. In accordance with the present invention, it is therefor desirable to optimize the residence time of the powder particles inside the spray gun. The residence time, the time spent by the powder particle from the moment it enters the jet of heated gas to the moment it exits the jet, must be controlled in conjunction with the gas jet temperature to minimize the dissociation of the ceramic compound. The higher the gas jet temperature, the faster the particles must exit the spray gun. Conversely, the lower the gas jet temperature, the less quickly the particles must exit the spray gun. It is necessary to control the residence time and the temperature of the thermal spray jet so that the ceramic particles are at least partly softened or near their dissociation temperature so that they will adhere to the surface and to each other on impact, but also so that the ceramic does not appreciably dissociate. Some dissociation of the ceramic is not necessarily harmful, particularly where the dissociation products are other wear-resistant ceramics such as titanium carbide. However, it is preferred that the ternary ceramics of the invention be maintained to the greatest extent possible.
[0026] Thermal spray processes that can be used to apply a coating in accordance with the present invention include, but are not limited to detonation gun techniques, both air and vacuum plasma spraying, high-velocity oxyfuel spray processes, wire arc spraying, conventional flame spraying and the like. The preferred thermal spray process to be used in accordance with the present invention is a high-velocity oxyfuel spray process, although any thermal spray process could be used. High-velocity oxyfuel processes involve the feeding of a gaseous fuel, oxygen and a coating powder into a spray gun. Inside of the gun the fuel is combusted, usually with oxygen although in some guns air is used, and the powder is fed into the path of the combusted fuel exiting through the nozzle of the gun. Particle velocity, which determines the residence time or dwell time of the particles, is a function of the combustion process gases and their flow rate, which is typically on the order of 1500 scfh (standard cubic feet per hour). The fuel used in high-velocity oxyfuel spraying processes can be a gas or liquid fuel. Gases commonly used are, for example, hydrogen, propylene, propane, and acetylene. An example of a liquid fuel used is kerosene.
[0027] The specific parameters used in the high-velocity oxyfuel spray process can vary. The distance from the nozzle tip to the surface being coated, the flow rates of the fuel and oxygen gases, and the horizontal speed of the spray gun relative to the part being coated are some examples of the parameters which can be varied in applying a coating in accordance with the present invention. When applying a coating of a ceramic compound in accordance with the present invention the spray distance, the distance from the exit of the gun nozzle to the surface being coated, should be from about 5 inches to about 10 inches, preferably from about 6 inches to about 9 inches, and more preferably from about 7 inches to about 8 inches. The horizontal traverse speed of the spray gun, the speed at which the stream of molten, or nearly molten, particles exiting the gun nozzle, moves across the surface of the article being coated should be from about zero feet per minute to about 100 feet per minute, preferably from about 1 foot per minute to about 50 feet per minute, and more preferably from about 2 feet per minute to about 40 feet per minute.
[0028] The gas used as the combustion fuel in a high velocity oxyfuel spray process can vary, but is usually hydrogen. The rate at which the oxygen is fed into the spray gun can be from about 400 standard cubic feet per hour (SCFH) to about 600 SCFH. The rate at which oxygen is fed into the spray gun is preferably from about 450 SCFH to about 550 SCFH, and more preferably about 500 SCFH. The rate at which hydrogen is fed into the spray gun can be from about 1000 SCFH to about 1800 SCFH. The rate at which hydrogen is fed into the spray gun is preferably from about 1050 SCFH to about 1250 SCFH, and more preferably from about 1100 SCFH to about 1200 SCFH. These rates can be adjusted accordingly for other common fuel gases used in high-velocity oxyfuel processes, such as propylene or acetylene, as is known in the art.
[0029] Other variables of concern with respect to the thermal spray process are the powder feed rate, the nozzle size, number of passes across the surface, and whether or not the surface is preheated. When the present invention is practiced using a high velocity oxyfuel spray process, the powder feed rate can be from about 5 grams per minute (g/m) to about 100 grams per minute (g/m). The powder feed rate is preferably from about 10 grams per minute (g/m) to about 80 grams per minute (g/m), and more preferably from about 20 grams per minute (g/m) to about 50 grams per minute (g/m).
[0030] The nozzle used in the high-velocity oxyfuel process in accordance with the present invention may be any normal spray nozzle used for such processes. A nozzle with an inner diameter of one quarter of an inch and a length of six to nine inches can be used, as is common in high-velocity oxyfuel spray processes. It should be understood that any conventional nozzle useful for high-velocity oxyfuel spray processes could be used.
[0031] The number of passes of the gun across the surface being coated can vary greatly. The number however, is proportional to the desired thickness of the coating. The gun may be passed across the surface as little as once and as many as 50 times, though preferably between 10 and 25 passes.
[0032] The surface being coated may also be preheated, for example, by passing the flame exiting the spray gun over the surface without having turned on the powder feed, or by other heating methods. By heating the surface just prior to applying the heated ceramic particles, the amount of stress on the resulting coating, that is caused by the contraction of the coating upon cooling, can be decreased. The surface may be preheated to whatever extent desired, though no preheating at all is required. The surface being coated and the ceramic compound being applied as a coating will often have different coefficients of thermal expansion. Based on the coefficients of thermal expansion for both the surface material and the coating ceramic, the surface can be preheated such that upon cooling, both the surface material and the ceramic contract equally, thereby minimizing stress on the coating. Other forms of pretreatment of the surface to be coated include gritblasting, sanding, and other mechanical or chemical roughening methods to improve adhesion of the coating to the surface.
[0033] The method of the present invention is useful for providing corrosion-resistant and/or wear-resistant coatings to the surfaces of metal and/or non-metal articles. The corrosion resistance of substrates coated with Ti 3 SiC 2 coatings is anticipated to be excellent in view of the preliminary corrosion results obtained from steel coupons coated with Ti 3 SiC 2 in accordance with the present invention and evaluated with various corrosive materials, as shown in Table I below:
TABLE I Temperature Time Weight Loss Corrosive Agent (° C.) (Hrs.) (grams) 25% H 2 SO 4 20 72 −0.0136 25% H 2 SO 4 20 96 −0.0150 25% H 2 SO 4 20 168 −0.0129 25% H 2 SO 4 20 240 −0.0296 25% H 2 SO 4 20 408 −0.0346 H 2 SO 4 (conc.) 20 72 −0.0622 H 2 SO 4 (conc.) 20 168 −0.0655 H 2 SO 4 (conc.) 20 240 −0.0776 H 2 SO 4 (conc.) 20 408 −0.0809 25% HCl 20 168 0.0039 25% HCl 20 432 0.0048 25% HCl 20 624 0.0066 25% HCl 20 768 0.0067 25% HCl 20 936 0.0074 HCl (conc.) 20 72 0.0038 HCl (conc.) 20 168 0.0047 HCl (conc.) 20 240 0.0050 HCl (conc.) 20 408 0.0060 25% HNO 3 20 72 0.1548 25% HNO 3 20 168 0.2178 25% HNO 3 20 408 0.2792 HNO 3 (conc.) 20 72 0.0207 HNO 3 (conc.) 20 168 0.0009 HNO 3 (conc.) 20 408 −0.0097
[0034] Negative weight loss measurements in Table I indicate a weight gain. As can be seen from Table I, most corrosive agents have a minimal effect on the ceramic blocks. In some cases, as with sulfuric acid (both concentrated and dilute), there is evidence (i.e. weight gain) of the formation of a passive coating on top of the ceramic, providing enhanced resistance to corrosion. Some corrosive agents, such as dilute nitric acid, appear to have more of an effect on the ceramic blocks than others, although all results indicate, at most, minimal weight loss over long periods of time.
[0035] The invention will now be illustrated in more detail with reference to the following specific, non-limiting examples. The particular size and material of the surface being coated is not critical in any of the following examples.
EXAMPLE 1
[0036] A thermally sprayed coating of a ternary ceramic compound was applied to a 1018 mild steel coupon having dimensions of 1 inch by 3 inches by 0.125 inches thick. The steel coupon was sprayed with powdered titanium silicon carbide, Ti 3 SiC 2 , having a maximum particle size no greater than 63 μm, using a high-velocity oxyfuel spray gun operating under the following parameters:
[0037] Powder Feed Rate: 25 grams/min.
[0038] Spray Distance: ˜7 inches
[0039] O 2 Gas Flow Rate: ˜500 SCFH.
[0040] H 2 Gas Flow Rate: ˜1100 SCFH.
[0041] Horizontal Traverse Speed: 20 ft./min.
[0042] Spray passes: 8
[0043] Preheating: None
[0044] The coating applied in the above manner had a thickness of approximately 0.006 inches.
[0045] Micrographic examination of the cross sections of the steel coupon produced according to Example 1 showed a coating of relatively uniform thickness which exhibited excellent bonding between the steel surface and the coating. Additionally, x-ray diffraction analysis of the unsprayed ceramic coating particles and the coating applied to the steel coupon according to Example 1 showed that the Ti 3 SiC 2 was substantially unchanged in its composition when it underwent thermal spraying to form a consolidated coating. The peaks present in the x-ray diffraction spectrum of the uncoated particles were compared with the peaks present in the x-ray diffraction spectrum of the coating. The presence of the same peaks at roughly the same intensities and roughly the same position indicates the lack of substantial change in the ceramic compositions.
EXAMPLE 2
[0046] A second 1018 mild steel coupon was sprayed with powdered titanium silicon carbide, Ti 3 SiC 2 , having a maximum particle size no greater than 65 μm and no smaller than 7 μm, using a high-velocity oxyfuel spray gun operating under the following parameters:
[0047] Powder Feed Rate: 25 grams/min.
[0048] Spray Distance: ˜9 inches
[0049] O 2 Gas Flow Rate: ˜500 SCFH
[0050] H 2 Gas Flow Rate: ˜1050 SCFH
[0051] Horizontal Traverse Speed: 20 ft./min.
[0052] Spray passes: 12
[0053] Preheating: 2 passes with spray gun without powder feed turned on to heat the surface to be coated to about 150° C.
[0054] Pretreatment: Grit blasted using #12 alumina grit
[0055] The coating applied in the above manner had a thickness of approximately 0.010 inches.
EXAMPLE 3
[0056] A third 1018 mild steel coupon was sprayed with powdered titanium silicon carbide, Ti 3 SiC 2 , having an maximum particle size no greater than 63 μm and minimum particle size no smaller than 7 μm, using a high-velocity oxyfuel spray gun operating under the following parameters:
[0057] Nozzle: 9 inches long
[0058] Powder Feed Rate: 25 grams/min.
[0059] Spray Distance: ˜8 inches
[0060] O 2 Gas Flow Rate: ˜500 SCFH
[0061] H 2 Gas Flow Rate: ˜1200 SCFH
[0062] Horizontal Traverse Speed: 2 ft./min.
[0063] Spray passes: 10-20
[0064] Preheating: 4-5 passes with spray gun without powder feed turned on to heat the surface to be coated to from about 100° C. to about 200° C.
[0065] Pretreatment: Grit blasted using #12 alumina grit
[0066] The coating applied in the above manner had a thickness of approximately 0.0115 inches.
EXAMPLE 4
[0067] A fourth 1018 mild steel coupon was sprayed with powdered titanium silicon carbide, Ti 3 SiC 2 , having an maximum particle size no greater than 45 μm, using an air plasma spray gun operating under the following parameters:
[0068] Powder Feed Rate: 25 grams/min.
[0069] Arc Current/Voltage: ˜1050 amps/˜50 volts
[0070] Spray Distance: ˜4 inches
[0071] Plasma-Forming Gas: argon/hydrogen
[0072] Ar Gas Flow Rate: ˜195 SCFH
[0073] H 2 Gas Flow Rate: ˜12.5 SCFH
[0074] Horizontal Traverse Speed: 15 ft./min.
[0075] Spray passes: 3
[0076] Preheating: None
[0077] Pretreatment: None
[0078] The coating applied in the above manner had a thickness of approximately 0.010 inches.
[0079] Using x-ray diffraction analysis, some decomposition of the coating particles in the coating of Example 4 was found. The decomposition was most likely due to the higher temperatures associated with the plasma spray process used.
[0080] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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Corrosion-resistant, oxidation-resistant, and/or wear-resistant coatings are made of ternary ceramic compounds of the general formula (I):
M 2 X 1 Z 1 (I)
wherein M is at least one transition metal, X is an element selected from the group consisting of Si, Al, Ge, Pb, Sn, Ga, P, S, In, As, Tl and Cd, and Z is a non-metal selected from the group consisting of carbon and nitrogen; and/or compounds of the general formula (II):
M 3 X 1 Z 2 (II)
wherein M is at least one transition metal, X is at least one of Al, Ge, and Si, and Z is at least one of carbon and nitrogen. Such coatings may be applied by a thermal spraying process.
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BACKGROUND
[0001] The subject invention relates generally to turbomachinery. More particularly, the subject invention relates to adjustment of turbomachinery components via magnetic forces.
[0002] Turbomachinery typically includes seals which are utilized to control clearances between rotating components and nonrotating components of the turbomachine. Examples of turbomachine seals include tip shrouds outboard of rotating bucket rows, and single or multi-tooth seals typically utilized between rows of fixed blades and a rotating shaft. During certain operating conditions, such as startup or shutdown and during transients, vibration and/or thermal growth of components may cause excessive wear to the seals and/or damage to other turbomachine components. Excessive wear of the seals shortens their useful life and also causes an increase in leakage of flow in the turbomachine which decreases the turbomachine's efficiency.
[0003] Control of clearance between the seals and rotating components is typically achieved through the use of radial and/or tangential springs to bias a seal's location. Seal position is sometimes controlled through the use of hydraulic or pneumatic actuators. The actuators, though, located outside of the casing of the turbomachine, require penetration through the casing of the turbomachine, which increases cost and potentially increases leakage through the casing.
BRIEF DESCRIPTION OF THE INVENTION
[0004] According to one aspect of the invention, a seal for a turbomachine includes at least one fixed component located proximate to a rotating component of the turbomachine defining a clearance therebetween. At least one magnet is located at the at least one fixed component. The at least one magnet is, when activated, capable of moving the at least one fixed component thereby adjusting the clearance between the fixed component and the rotating component.
[0005] According to another aspect of the invention, a turbomachine includes a casing and at least one rotating component located in the casing and rotatable about a central axis of the turbomachine. At least one fixed component is located in the casing to define a clearance between the at least one rotating component and the at least one fixed component, and at least one magnet located such that when the at least one magnet is activated, the clearance between the at least one rotating component and the at least one fixed component is adjusted.
[0006] According to yet another aspect of the invention, a method for adjusting a position of at least one fixed component of a turbomachine includes locating at least one magnet proximate to the at least one fixed component and activating the at least one magnet thereby creating a magnetic field in magnetic communication with the at least one fixed component. The at least one fixed component is moved via the magnetic field.
[0007] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0009] FIG. 1 is a cross-sectional view of an embodiment of a turbomachine;
[0010] FIG. 2 is a cross-sectional view of an embodiment of a single or multi-tooth seal with magnetic adjustment;
[0011] FIG. 3 is a cross-sectional view of another embodiment of a single or multi-tooth seal with magnetic adjustment;
[0012] FIG. 4 is a cross-sectional view of an embodiment of a tip shroud with magnetic adjustment; and
[0013] FIG. 5 is a cross-sectional view of another embodiment of a tip shroud with magnetic adjustment.
[0014] FIG. 6 is a cross-sectional view of another embodiment of a tip shroud with magnetic adjustment;
[0015] FIG. 7 is another cross-sectional view of the tip shroud of FIG. 6 ;
[0016] FIG. 8 is a view of a magnetically adjustable variable vane; and
[0017] FIG. 9 is a partially exploded view of the variable vane of FIG. 8 .
[0018] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Shown in FIG. 1 is a cross-sectional view of an embodiment of a turbine 10 of, for example, a gas turbine or steam turbine. The turbine 10 includes a turbine rotor 12 having one or more rows of turbine buckets 14 arrayed circumferentially around a rotor disc 60 . The rotor 12 is rotatable about a central axis 18 and is disposed in a casing 20 . The turbine 10 includes one or more blade rows 22 which are disposed axially between rows of the turbine buckets 14 . At least one tip shroud 24 is disposed radially outboard of each row of the one or more rows of turbine buckets 14 . Each tip shroud 24 may be comprised of a plurality of shroud segments (not shown). The tip shroud 24 and the turbine buckets 14 define a tip clearance 28 therebetween, as best shown in FIG. 4 . Referring again to FIG. 1 , a ring of seals, for example, single or multi-tooth seals 30 may be disposed radially between each blade row 22 and rotating structure, for example, a rotating seal 16 . The rotating seal 16 and the seals 30 define a rotor clearance 32 therebetween, as best shown in FIG. 2 .
[0020] During operation of the turbine 10 , it may be advantageous to change a position of the seals 30 to adjust the rotor clearance 32 during, for example, start up or shutdown of the turbine 10 , or during transients. In these operating conditions, vibration and/or thermal growth of the components could lead to excessive wear of the seals 30 . As shown in FIG. 2 , at least one magnetic actuator 34 is disposed at the seal 30 , in some embodiments fixed to a seal housing 36 . The at least one magnetic actuator 34 is configured and disposed such that when an electric current is introduced to the magnetic actuator 34 , a magnetic field is generated which causes the seal 30 to move away from the rotating seal 16 thus increasing the rotor clearance 32 . Alternatively, the magnetic actuator 34 may be configured to move the seal 30 toward the rotating seal 16 when electrical current is introduced to the at least one magnetic actuator 34 . It is to be appreciated that, while the electromagnetic actuator 34 of the embodiment of FIG. 2 is configured to move the seal 30 in a radial direction, it is to be appreciated that the electromagnetic actuator 34 may be configured to move the seal 30 in other directions, for example, an axial direction.
[0021] In some embodiments, at least one feedback device, for example at least one proximity sensor 38 is disposed at the seal 30 . The proximity sensor 38 is disposed to measure and provide feedback on clearance between the seal 30 and the rotating seal 16 . In some embodiments, the proximity sensor 38 is in operable communication with the at least one magnetic actuator 34 such that the magnetic actuator 34 moves the seal 30 based on feedback from the proximity sensor 38 . Further, in some embodiments, one or more springs 40 may be disposed at a radially outward portion of the seal 30 to bias the position of the seal 30 . The springs 40 may be configured to bias the position of the seal 30 in a direction to assist the magnetic actuator 34 in moving the seal 30 , or to counter the magnetic actuator 34 in moving the seal 30 .
[0022] In some embodiments, as shown in FIG. 3 , a magnetic field may be utilized to move the seal 30 via at least one magnet 42 disposed outside of the casing 20 . In some embodiments, the at least one magnet 42 is an electromagnet secured outside of the casing 20 , such that when a magnetic field is generated by introducing electrical current to the magnet 42 , the seal 30 is moved away from the magnet 42 by the magnetic field. In some embodiments, the magnet 42 moves the seal 30 by moving the blade row 22 associated with the desired seal 30 away from the magnet 42 . It is to be appreciated that, in some embodiments, the magnet 42 may be configured to attract, rather than repel the blade row 22 and/or the seal 30 thus moving the seal 30 toward the magnet 42 when the magnetic field is generated. In the embodiment shown in FIG. 3 , since the magnet 42 is disposed outside of the casing 20 , there is no need to penetrate the casing 20 thereby reducing the potential for leakage from the casing 20 , and simplifying fabrication of and reducing cost of the casing 20 .
[0023] While the embodiments described to this point have utilized magnetic fields to move seals 30 , magnetic fields may be utilized to move other components, for example, the at least one tip shroud 24 . As shown in FIG. 4 , at least one magnetic actuator 34 is disposed at the casing 20 and is configured to move the tip shroud 24 when the magnetic actuator 34 is activated to adjust the tip clearance 28 . The magnetic actuator 34 may be configured to attract or repel the tip shroud 24 when activated, depending on the requirements of the particular turbine 10 . In some embodiments, at least one proximity sensor 38 is disposed at the tip shroud 24 to measure the tip clearance 28 . The magnetic actuator 34 may move the tip shroud 24 based on feedback from the proximity sensor 38 .
[0024] Further, as shown in FIG. 5 , at least one magnet 42 disposed outside the casing 20 may be utilized to move the tip shroud 24 via the magnetic field created by the magnet 42 . In the embodiment of FIG. 5 , since the magnet 42 is disposed outside of the casing 20 there is no need to penetrate the casing 20 to allow access for components which move the ring of the tip shroud 24 . This reduces leakage through the casing 20 , and also simplifies and reduces cost of fabrication of the casing 20 .
[0025] As shown in FIG. 6 , at least one magnet 42 may be utilized to move a tapered seal 44 in an axial direction to adjust the tip clearance 28 . The tapered seal 44 is positioned between the turbine buckets 14 and the casing 20 . In the embodiment of FIG. 6 , two magnets 42 are disposed at the casing 20 . When an electrical current is provided to magnet 42 a , a magnetic field is created which moves the tapered seal 44 in an axial direction toward magnet 42 a , thus adjusting the tip clearance 28 from a closed condition as shown in FIG. 6 to an opened condition as shown in FIG. 7 . With the tip clearance 28 in the opened condition, the electrical current to magnet 42 a may be turned off, and an electrical current provided to magnet 42 b to create a magnetic field which moves the tapered seal 44 toward magnet 42 b thus adjusting the tip clearance from the opened condition to the closed condition shown in FIG. 6 . Further, in some embodiments, the magnets 42 a and 42 b may be configured with switchable, opposing polarity. For example, magnet 42 a may initially have a positive polarity and magnet 42 b may have a negative polarity. To move the tapered seal 44 toward magnet 42 a , both magnets 42 a and 42 b are energized, with magnet 42 a attracting the tapered seal 44 and magnet 42 b repelling the tapered seal 44 thus providing additional force to move the tapered seal 44 toward magnet 42 a . To move the tapered seal toward magnet 42 b , the polarities are reversed such that magnet 42 b attracts the tapered seal 44 and magnet 42 a repels tapered seal 44 .
[0026] As shown in another embodiment shown in FIGS. 8 and 9 , an electromagnetic actuator 34 may be utilized to adjust positions of gas path components such as rotating variable vanes 46 . In the embodiment of FIG. 8 , the electromagnetic actuator 34 is disposed outside of the casing 20 , and is in magnetic communication with a target 48 disposed inside of the casing 20 . The target 48 is connected to a slider-follower cam 50 , which in this embodiment includes an internal spline 52 , as best shown in FIG. 9 . A slide connector 54 with a corresponding external spline 56 is inserted into the cam 50 and is connected to the variable vane 46 . When the electromagnetic actuator 34 is activated, the target 48 is either attracted to or repelled from the electromagnetic actuator 34 along a slider axis 58 . The movement of the target 48 along the slider axis 58 is translated into rotational motion of the variable vane 46 about the slider axis 58 via the cam 50 . Although a slider-follower cam 50 is utilized in the embodiments of FIGS. 8 and 9 , other means for translating linear motion to rotational motion, for example, a helical spline connection may be utilized. Some embodiments may include one or more springs (not shown) to return the variable vane 46 to a home position when the electromagnetic actuator 34 is deactivated. Further, reversing a polarity of the electromagnetic actuator 34 may also accomplish this function.
[0027] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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Disclosed is a seal for a turbomachine including at least one fixed component located proximate to a rotating component of the turbomachine defining a clearance therebetween. At least one magnet is located at the at least one fixed component. The at least one magnet is, when activated, capable of moving the at least one fixed component thereby adjusting the clearance between the fixed component and the rotating component. Further disclosed is a turbomachine utilizing the seal and a method for adjusting a position of at least one fixed component of a turbomachine.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-060957, filed on Mar. 24, 2016, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to a non-transitory computer-readable storage medium, and a display control device.
BACKGROUND
[0003] Video picture data processing systems for extracting the video image of a desired scene from a large volume of video picture data have been proposed. In this system, video picture data segmented in time series for each of the desired scenes (in a pitch delivery unit in a baseball game, for example) of a subject is associated with corresponding retrieval data of various kinds, and stored as a video picture database. Desired video picture data is extracted from the video picture database.
CITATION LIST
Patent Literature
[0004] [PATENT LITERATURE 1] Japanese Laid-open Patent Publication No. 2001-229195
SUMMARY
[0005] According to an aspect of the invention, a non-transitory computer-readable storage medium storing a display control program that causes a computer to execute a process, the process including, in response to a selection of a retrieval item from a plurality of retrieval items, displaying, on a display screen, an input area of a retrieval condition corresponding to the selected retrieval item, displaying, in an area different from the input area on the display screen, a retrieval result retrieved according to a retrieval condition entered in the input area, while maintaining the display of the input area, receiving a selection of any content from a plurality of contents included in the displayed retrieval results, and in response to the selection of the content, displaying an reproduction area that reproduces an image or a video image corresponding to the selected content while maintaining the display of the retrieval results, the reproduction area overlapping at least a part or a whole of the input area, the input area being hidden in response to displaying the reproduction area.
[0006] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a functional block diagram illustrating a schematic configuration of a display controller according to an embodiment;
[0009] FIG. 2 illustrates an example of a player information table;
[0010] FIG. 3 illustrates an example of an inter-user correspondence information table;
[0011] FIG. 4 illustrates an example of a pitching meta data table;
[0012] FIG. 5 is a diagram for illustrating a pitching course;
[0013] FIG. 6 is a diagram for illustrating a hitting direction;
[0014] FIG. 7 illustrates an example of a result information table;
[0015] FIG. 8 illustrates an example of a game information table;
[0016] FIG. 9 illustrates an example of a top page screen;
[0017] FIG. 10 illustrates an example of a retrieval and reproduction screen;
[0018] FIG. 11 illustrates an example of a retrieval result list area when a situation display button is selected;
[0019] FIG. 12 illustrates an example of a retrieval result list area when an all-pitches display button is selected;
[0020] FIG. 13 illustrates an example of a retrieval and reproduction screen where a narrowing condition entry area for entering the pitching course is indicated;
[0021] FIG. 14 illustrates an example of a retrieval and reproduction screen where a narrowing condition entry area for entering the pitch type is displayed;
[0022] FIG. 15 illustrates an example of a retrieval and reproduction screen where a narrowing condition entry area for entering the hitting direction is displayed;
[0023] FIG. 16 illustrates an example of a retrieval and reproduction screen where a narrowing condition entry area for entering the count and runner state is displayed;
[0024] FIG. 17 illustrates an example of a personal result screen when the target player is a fielder;
[0025] FIG. 18 illustrates an example of a personal result screen when the target player is a pitcher;
[0026] FIG. 19 illustrates an example of a game log screen;
[0027] FIG. 20 is a block diagram illustrating a schematic configuration of a computer that functions as the display controller according to the embodiment;
[0028] FIG. 21 is a flowchart illustrating an example of a display control processing in the embodiment;
[0029] FIG. 22 is a flowchart illustrating an example of a retrieval and reproduction screen processing;
[0030] FIG. 23 is a flowchart illustrating an example of a personal result screen processing; and
[0031] FIG. 24 is a flowchart illustrating an example of a game log screen processing.
DESCRIPTION OF EMBODIMENTS
[0032] One aspect of the present disclosure has an object to improve operability in retrieval of an image or a video image.
[0033] Hereinafter, an embodiment according to the present disclosure is described in detail with reference to the accompanying drawings. The embodiment is described by taking as an example a case where a retrieval target video image is a baseball game video image.
[0034] As illustrated in FIG. 1 , a display controller 10 according to the embodiment is coupled with a distribution server 20 configured to distribute a baseball game video image via a network or the like, and performs display control when a video image acquired from the distribution server 20 is reproduced by a display device 84 .
[0035] The distribution server 20 stores a video image file 21 indicating video images of captured baseball games. In the embodiment, one video image file 21 is provided for each game. Each video image file 21 is managed in a uniquely identifiable manner such that the video image file 21 is assigned with a file name using the game date and the playing teams in the game recorded in the video image file 21 . For example, a video image file 21 of a game between Team A and Team B held on Apr. 10, 2016 may be assigned with a file name such as “20160410AB”.
[0036] Each video image file 21 is a video image captured at a frame rate of, for example, such as 30 fps or 60 fps, and includes multiple frames. Each frame is associated with a frame time represented by a time elapsed since the start of capturing, and the frame time is used as identification information of each frame.
[0037] In the video image file 21 , a section indicating a segment in the play is assigned with information indicating the segment in the play. In the embodiment, with every pitch of the pitcher is set as a segment of the play, and a “pitch tag” is assigned at a section indicating the start of the pitch by the pitcher. More specifically, the pitch tag is assigned, for example, to a frame at a predetermined time before (for example, 3 seconds before) the start of the pitching motion of the pitcher among frames included in the video image file 21 .
[0038] The distribution server 20 stores a related information database (DB) 22 in which various information related to the video image file 21 is stored. In the embodiment, the related information DB 22 includes a player information table, an inter-user correspondence information table, a pitching meta data table, a result information table, and a game information table. The related information DB 22 also may include other information related to the video image file 21 . Hereinafter, tables of the related information DB 22 are described.
[0039] The player information table is a table in which player information being information of each player is stored. FIG. 2 illustrates an example of a player information table 23 . In the example of FIG. 2 , each row (each record) indicates player information for one player. Each record of player information includes information such as “player ID” for uniquely identifying the player, “player's name”, “team” which is the team name of a team to which the player belongs, “position”, “uniform number”, “pitching/batting method”, and “picture”. “Position” is information from which at least the player is identifiable as a pitcher or a fielder. For the fielder, the infielder or the outfielder may be used as identifiable information, or more specific position such as the catcher, first baseman, and left fielder may be used as identifiable information. “Pitching/batting method” is information indicating, when the player is a pitcher, whether the player is right-handed or left-handed for pitching, and, when the player is a fielder, information indicating whether the player is right-handed (right batter's box) or left-handed (left batter's box) for batting. “Picture” is image data such as a face photograph of the player.
[0040] The inter-user correspondence information table is a table which stores information indicating a correspondence relationship among users utilizing the application provided by the embodiment. The correspondence relationship among users in the embodiment is, for example, an association among users such as a relationship between a follow and a follower in Twitter (registered trademark). Although described in detail below, when information for the log-in user is provided on the top page displayed first when the user logs in this application, information related to the user whom the log-in user follows is also provided.
[0041] FIG. 3 illustrates an example of an inter-user correspondence information table 24 . In the example of FIG. 3 , the user ID of a user whom a user represented by the user ID follows is stored for each of user IDs by associating as “follow target user ID”. When the user utilizing the application is a player registered in the player information table 23 , the user ID is the player ID.
[0042] The pitching meta data table is a table which stores pitching meta data being meta data of each pitch scene. Each pitch scene is represented, for each “pitch tag” assigned to the video image file 21 , by a group of frames starting from a frame to which the pitch tag is assigned and ending at a frame preceding a frame to which a next pitch tag is assigned.
[0043] FIG. 4 illustrates an example of a pitching meta data table 25 . In the example of FIG. 4 , each row (each record) indicates pitching meta data on the pitch scene of every pitch. In each record of pitching meta data, “file name” for identifying the video image file 21 , a frame time to which “pitch tag” is assigned, and information on the pitch scene starting from a frame to which the pitch tag is assigned are associated with each other. Information on the pitch scene includes information such as “game date”, “inning”, “fielding team”, “pitcher”, “batting team”, “batter”, “batting order”, “pitch result”, “at-bat result”, “pitching course”, “pitch type”, “hitting direction”, “count”, and “runner”.
[0044] “Game date” is a date when a game including the pitch scene thereof is held. “Inning” is an inning (a top of the first inning, a bottom of the first inning, a top of the second inning, etc.) at the time of a pitch presented in the pitch scene. “Fielding team” is a team to which a pitcher performing the pitch indicated by the pitch scene belongs, and “pitcher” is information such as the player ID and player's name for identifying the pitcher. “batting team” is a team to which a batter at the time of the pitch presented in the pitch scene belongs, and “batter” is information such as the player ID and player's name for identifying the batter. “Batting order” is a batting order (1, 2, . . . , 9) of batters at the time of the pitch presented in the pitch scene.
[0045] “Pitch result” is information indicating that result of the pitch in the pitch scene is strike or ball. The strike may be more specific information from which swing and miss, called strike or foul is identifiable. When a batter hits the pitched ball (except for the foul) or when the pitch is not judged as strike or ball, “pitch result” is left blank (in the example of FIG. 4 , represented by “-”).
[0046] “At-bat result” is a result of the at-bat assigned when a pitch indicated by the pitch scene is a last pitch in the at-bat including the pitch, such as, for example, hit, out or others. More specifically, the hit may be a single, a double, a triple, or a home run as identifiable information, and the out may be a single out, double play or strikeout as identifiable information. More specifically, the hit may be a result of combination of the hitting direction and the rise of hit ball such as a hit to a center and a fly to a right field. Others include, for example, four balls, hit by pitch, sacrifice bunt, sacrifice fly, error, fielder's choice, catcher's interference, fielder's interference, obstruction, and so on. When a pitch included in the pitch scene is not a last pitch in the at-bat including the pitch, “at-bat result” is left blank (in the example of FIG. 4 , represented by “-”.
[0047] “Pitching course” is a course (zone) where the pitched ball indicated by the pitch scene has passed. “Pitching course” may be represented by the number of the block where the pitched ball has passed through, for example, by dividing the strike zone and peripheral zones thereof into multiple blocks and assigning a number to each of the blocks as illustrated in FIG. 5 . “Pitch type” is information indicating the pitch type of the pitch indicated by the pitch scene, such as, for example, straight, 2-seam, splitter, change-up, cutter, curve, slider, sinker, and other special types. “Hitting direction” is a direction of the ball hit by a batter against the pitched ball indicated by the pitch scene. “Hitting direction” may be represented by the symbol of the block where the hit ball has reached, for example, by dividing the ground into multiple blocks and assigning a symbol to each of the blocks as illustrated in FIG. 6 .
[0048] “Count” is the count of balls, strikes, and outs at the starting time of the pitch scene, represented in the format of “(ball count, strike count, out count)”. For example, 3 balls, 1 strike and 2 outs are represented by “(3, 1, 2)”. “Runner” indicates states of runners at the starting time of the pitch scene represented in the format of “(presence or absence of first runner, presence or absence of second runner, presence or absence of third runner)”. For example, presence of the runner is represented by “1” and absence of the runner is represented by “0”. Presence of the runner only on the first base is represented by “(1, 0, 0)”.
[0049] The result information table is a table in which results depending on the states of each of players are stored. The result information table stores, for example, total results from the start of the season to the last game. FIG. 7 illustrates an example of the result information table 26 . In the example of FIG. 7 , various results for both the case where the player is a fielder and the case where the player is a pitcher are stored.
[0050] In the case where the player is a fielder, “at-bat result breakdown”, “hitting direction breakdown”, “course-based batting average”, and “pitch type-based batting average” are stored. “At-bat result breakdown” is the ratios of hit and out per at-bat result, “hitting direction breakdown” is, for example, the number of hits in each of the hitting directions as illustrated in FIG. 6 , “course-based batting average” is, for example, the batting average in each of the pitching courses as illustrated in FIG. 5 , and “pitch type-based batting average” is the batting average in each of the pitch types. In the same manner, in the case where the player is a pitcher, “at-bat-based pitch result breakdown”, “course-based batted average”, and “pitch type-based batted average” are stored. In the case of the pitcher, the result is an at-bat-based pitch result or batted average. In the case where the player is a pitcher, runner state and “situation based batted average” indicating the ball count-based batted average are also stored as the result. Various results are not limited to those examples, and may include a batting average and a batted average for each of opponent teams, a batting average based on the throwing method of the pitcher (right-handed or left-handed), and a batted average based on the hitting method of the batter (right-handed hitting or left-handed hitting), and so on. Also, the result of the fielder may include the record of the situation-based batting average, and the result of the pitcher may include the hit direction breakdown.
[0051] The game information table is a table in which game information indicating the overview of each game is stored. FIG. 8 illustrates an example of the game information table 27 . In the example of FIG. 8 , each row (each record) indicates game information for one game. Each row of game information includes information of “game date” when the game was held, “home team” and “visitor team” as playing teams in the game, and “home score” and “visitor score” indicating final scores of respective teams. The game information also includes information such as “inning-based score” indicating the score in each inning, and “winning pitcher” and “losing pitcher” in the game. Further, information such as the relief pitcher and the home run also may be included.
[0052] The display controller 10 includes an acquisition unit 11 and a display control unit 12 in terms of the function.
[0053] The acquisition unit 11 receives the user ID of the user who logs in the application provided by the embodiment and transmits the user ID to a distribution server 20 . The acquisition unit 11 acquires top page information transmitted from the distribution server 20 as information to be displayed on the top page displayed first after user's log-in. In the case where the user ID of the log-in user is a player ID, the top page information includes player information for the player ID, the player information being extracted from the player information table 23 .
[0054] The top page information also includes a thumbnail image generated in any frame of a predetermined pitch scene included in the video image file 21 , and pitching meta data of the pitch scene. The predetermined pitch scene includes, for example, pitch scenes for last several games of the log-in user (player), pitch scenes for last several games of a user (player) whom the log-in user follows, and a pitch scene assigned with a message from the other user. Also, the top page information may include information not associated with the video image file 21 , for example, such as a meeting document. The acquisition unit 11 delivers the acquired top page information to the display control unit 12 .
[0055] The acquisition unit 11 receives the retrieval condition of the video image from the log-in user, transmits the received retrieval condition to the distribution server 20 , and thereby requests distribution of the video image. Thus, the distribution server 20 identifies, with the received retrieval condition as a key, a pitch scene matching the retrieval condition out of the pitching meta data table 25 . Then, the distribution server 20 distributes a video image file 21 including the identified pitch scene and pitching meta data of the identified pitch scene to the display controller 10 . The acquisition unit 11 acquires the video image file 21 and pitching meta data distributed from the distribution server 20 and delivers the acquired video image file 21 and pitching meta data to the display control unit 12 .
[0056] When the personal result screen (described below in detail) is selected by the log-in user, the acquisition unit 11 transmits the player ID of the player entered on the personal result screen to the distribution server 20 and thereby requests result information of the entered player. Then, the acquisition unit 11 acquires result information of the entered player which is extracted from the result information table 26 and transmitted from the distribution server 20 , and delivers the acquired result information to the display control unit 12 .
[0057] When the game log screen (described below in detail) is selected by the log-in user, the acquisition unit 11 transmits the entered game date to the distribution server 20 and thereby requests game information of the entered game date for the team to which the log-in user belongs. Then, the acquisition unit 11 acquires game information of the entered game date which is extracted from the game information table 27 and transmitted from the distribution server 20 , and delivers the acquired game information to the display control unit 12 .
[0058] The display control unit 12 controls screen display to a display device 84 based on information delivered from the acquisition unit 11 and operation of the log-in user.
[0059] More specifically, upon receiving the top page information from the acquisition unit 11 , the display control unit 12 displays, for example, a top page screen 40 as illustrated in FIG. 9 on the display device 84 . The top page screen 40 includes a top page tab 31 for switching the screen displayed on the display device 84 , a retrieval and reproduction tab 32 , a personal result tab 33 , and a game log tab 34 . The top page screen 40 is a screen in a state where the top page tab 31 is selected. The top page screen 40 includes a log-in user display area 41 , a recent at-bat display area 42 , and a time line display area 43 .
[0060] The display control unit 12 displays, based on the player information of the log-in user delivered from the acquisition unit 11 , player's name, team, position, uniform number, throwing method or hitting method, and picture of the log-in user, in the log-in user display area 41 . In the case where the log-in user is not a player, name, title (director, coach, staff, etc.), and picture of the log-in user may be managed in a table (not shown) similar with the player information table 23 , and those information may be displayed in the log-in user display area 41 .
[0061] The display control unit 12 displays, based on pitching meta data of the pitch scene for last several games of the log-in user delivered from the acquisition unit 11 , the at-bat result for a predetermined number of at-bats in the descending order from a latest at-bat, in the recent at-bat display area 42 . For example, in the example of FIG. 9 , the display control unit 12 displays, for each at-bat, the date, inning, opponent team, opponent pitcher or opponent batter, and at-bat result in each of frames. When a frame indicating any at-bat is selected from the recent at-bat display area 42 , the display control unit 12 delivers the pitching meta data used for displaying information of the selected at-bat to the acquisition unit 11 as the retrieval condition.
[0062] The display control unit 12 generates the performance card based on the thumbnail image and pitching meta data delivered from the acquisition unit 11 . The performance card provides information recommended to the log-in user such as performance of the game in which the log-in user played and performance of the game in which a user followed by the log-in user played, in a card format. The performance card indicates a thumbnail image of the pitch scene and predetermined information extracted from the pitching meta data. The predetermined information is different depending on whether the target player (log-in user or user followed by log-in user) of the performance card is a pitcher or a fielder. More specifically, in the case where the target player of the performance card is a fielder, the predetermined information may be, for example, the at-bat result of each at-bat. In the case where the target player of the performance card is a pitcher, the predetermined information may be, for example, the opponent team. Since most of fielders play in almost every game, the performance card of the game may be easily recognized by indicating the at-bat result for each of games. Since the pitcher, especially a starting pitcher, does not play in every game, the performance card of the game may be more easily recognized by indicating the opponent team rather than by indicating such as the pitch result of each pitch in the game, for example.
[0063] In the case where the message is assigned with the pitch scene, the display control unit 12 generates a performance card including a thumbnail image of the pitch scene and the message. The display control unit 12 also generates a performance card for other information included in the top page information. For example, in the case where a meeting document is included in the top page information, the display control unit 12 may generate a performance card which describes the date when the meeting is held, with the meeting document attached thereto.
[0064] The display control unit 12 displays the generated performance card in the time line display area 43 by arranging, in the descending order, dates relevant to the performance card such as, for example, date of the game indicated by the performance card, date included in the message, and date when the meeting is held. For example, in the example of FIG. 9 , performance cards 44 A and 44 E are performance cards indicating performance of games in which the log-in user played. The performance card 44 A is a performance card of a last game, and the performance card 44 E is a performance card of a game preceding the last game. In the example of FIG. 9 , the log-in user is a fielder. Thus, performance cards 44 A and 44 E indicate the at-bat result of each at-bat.
[0065] A performance card 44 B is a performance card indicating performance of a game in which a player (pitcher) followed by the log-in user plays, and a performance card 44 C is a performance card indicating performance of a game in which a player (fielder) followed by the log-in user plays. The performance card 44 B indicates the opponent team as the target player is a pitcher, and the performance card 44 C indicates the at-bat result of each at-bat as the target player is a fielder.
[0066] A performance card 44 D is an example of a performance card to which a meeting document or the like is attached, and a performance card 44 F is an example of a performance card to which a message is assigned. Hereinafter, when collectively referred to without distinction, the performance cards 44 A, 44 B, 44 C, 44 D, 44 E, and 44 F are merely represented by “performance card 44 ”.
[0067] When any performance card 44 including a thumbnail image is selected from the time line display area 43 , the display control unit 12 delivers the pitching meta data used for generating the selected performance card 44 to the acquisition unit 11 as the retrieval condition. When a performance card 44 not including a thumbnail image is selected, the display control unit 12 performs a processing corresponding to the performance card 44 such as opening of a document attached to the performance card 44 .
[0068] When the retrieval and reproduction tab 32 is selected, the display control unit 12 displays, for example, a retrieval and reproduction screen 50 such as illustrated in FIG. 10 on the display device 84 . The retrieval and reproduction screen 50 includes a top page tab 31 , a retrieval and reproduction tab 32 , a personal result tab 33 , and a game log tab 34 . The retrieval and reproduction screen 50 is a screen in a state where the retrieval and reproduction tab 32 is selected. The retrieval and reproduction screen 50 includes a target player entry area 51 , an opponent player entry area 52 , a pitch/at-bat result entry area 53 , a game date entry area 54 , narrowing condition areas 55 A, 55 B, 55 C, 55 D, and a retrieval result list area 56 . The retrieval and reproduction screen 50 further includes a video image reproduction area 57 and a display control button group 58 . Each of the target player entry area 51 , opponent player entry area 52 , pitch/at-bat result entry area 53 , game date entry area 54 , and narrowing condition areas 55 A, 55 B, 55 C, 55 D is an area for entering a retrieval condition of the video image.
[0069] When a select button 51 A included in the target player entry area 51 is selected, the display control unit 12 provides a display for entering the target player. For example, the display control unit 12 acquires player information in the player information table 23 of the distribution server 20 , generates a list of players for each of teams, and displays players in a selectable state. The display control unit 12 displays information of the selected player in the target player entry area 51 .
[0070] When a select button 52 A included in the opponent player entry area 52 is selected, the display control unit 12 provides a display for entering the opponent player as in the case of entering the target player. The display control unit 12 displays information of the selected player in the opponent player entry area 52 . The entering method for the opponent player also includes entering all players and entering all players belonging to a specific team. When the opponent player is a pitcher, the entering method also includes entering the left-handed or right-handed player, and when the target player is a fielder, the entering method also includes entering the right-handed or left-handed player as the opponent player.
[0071] When a select button 53 A included in the pitch/at-bat result entry area 53 is selected, the display control unit 12 provides a display for entering the pitch result and at-bat result. For example, the pitch result is displayed in such a manner that all pitch results, strikes, or balls are selectable. The strike may be more specific information from which called strike, swing and miss, or foul is selectable. The at-bat result may be displayed in such a manner that all at-bat results, hits, outs, or others are selectable. The hit may be displayed in such a manner that the single, double, triple, or home run is selectable. The out may be displayed in such a manner that the single out, double play, or strikeout is selectable. Others may be displayed in such a manner that the four balls, hit by pitch, sacrifice fly, or the like is selectable. Further, the hit and out may be displayed in such a manner that the more specific at-bat result such as hit to a center and fly to a right field is selectable. The display control unit 12 displays the selected pitch result or at-bat result in the pitch/at-bat result entry area 53 .
[0072] Display for selecting the above target player, opponent player, and pitch/at-bat result is provided, for example, by displaying a pull-down menu or another window. An entry by direct input into the text box or the like also may be accepted.
[0073] When the target player, opponent player, and pitch/at-bat result are entered, the display control unit 12 delivers the target player, opponent player, and pitch/at-bat result entered in their respective entry areas to the acquisition unit 11 as retrieval conditions. Thus, the display control unit 12 acquires the video image file 21 and pitching meta data distributed from the distribution server 20 via the acquisition unit 11 . When any performance card 44 or a recent at-bat is selected on the above top page screen 40 , the display control unit 12 displays a retrieval condition in each entry area based on the pitching meta data corresponding to the selected performance card 44 or recent at-bat.
[0074] Based on the acquired pitching meta data, the display control unit 12 displays a list of retrieval results in the retrieval result list area 56 in a state where each of the retrieval results is selectable. In the example of FIG. 10 , the display control unit 12 displays each retrieval result 56 A within one frame, wherein at-bats including the pitch scene matching the retrieval condition are displayed as one retrieval result 56 A. In the example of FIG. 10 , a frame indicating one retrieval result contains information indicating the game date, inning, opponent team, opponent player, pitch result or at-bat result, pitch type, pitching course, hitting direction, and the ordinary number of pitch in the at-bat. Unless the retrieval condition selecting the pitched ball is not entered, the retrieval result 56 A is displayed based on pitching meta data for a pitch scene indicating a last pitched ball in the at-bat. In the case where the retrieval condition selecting the pitched ball is entered, the retrieval result 56 A is displayed based on pitching meta data for a pitch scene matching the retrieval condition. The retrieval condition selecting the pitched ball is entered with the pitch result entered in the pitch/at-bat result entry area 53 and with any of narrowing conditions described below. The pitching course and hitting direction are represented by a symbol image indicating the pitching course and a symbol image indicating the hitting direction respectively.
[0075] The display control unit 12 displays a selected retrieval result 56 A out of retrieval results 56 A included in the retrieval result list area 56 , in a display mode different from other retrieval results 56 A. In the example of FIG. 10 , the frame line of the selected retrieval result 56 A is depicted with a heavy line, and unselected frame lines of retrieval results 56 A are depicted with a broken line.
[0076] When a situation display button 56 B included in the retrieval result list area 56 is selected, the display control unit 12 , for example, develops display of the retrieval result list area 56 and additionally displays the situation of the count and runner within the frame of each retrieval result 56 A as illustrated in FIG. 11 . In the example of FIG. 11 , the situation of the count and runner is represented by a symbol image indicating the count, and a symbol image indicating the situation of the runner respectively.
[0077] When an all-pitches display button 56 C included in each retrieval result 56 A is selected, the display control unit 12 , for example, develops display of a retrieval result 56 A matching the selected all-pitches display button 56 C as illustrated in FIG. 12 . Then, the display control unit 12 displays information of each pitch scene included in the at-bat indicated by the retrieval result 56 A. The display control unit 12 displays information of the pitch scene displayed before developing the retrieval result 56 A, in a display mode different from other pitch scenes. In the example of FIG. 12 , the display control unit 12 makes reverse display in a portion indicating for which pitch in the at-bat the pitch scene is displayed before developing the retrieval result 56 A.
[0078] Based on the pitching meta data corresponding to the retrieval result 56 A selected in the retrieval result list area 56 , the display control unit 12 identifies the selected pitch scene out of the acquired video image file 21 and reproduces in the video image reproduction area 57 . More specifically, the display control unit 12 identifies the video image file 21 by “file name” of the pitching meta data corresponding to the selected retrieval result 56 A, and reproduces the identified video image file 21 from a frame indicated by the frame time in “pitch tag” of the pitching meta data. When any retrieval result 56 A is not selected from the retrieval result list area 56 by the log-in user, reproduction may be started automatically from a video image corresponding to a predetermined retrieval result 56 A, for example, such as a leading retrieval result 56 A.
[0079] When any button included in the display control button group 58 is selected, the display control unit 12 performs display control matching the selected button for the video image reproduced in the video image reproduction area 57 . The display control button group 58 , for example, includes a reproduction/pause button, a fast reversing button, a fast-forward button, a frame feed button, a frame reversing button, and so on. When the reproduction/pause button is selected, the display control unit 12 performs pause control of the video image being reproduced or performs reproduction control of the video image being paused. When the fast reversing button is selected, the display control unit 12 performs fast reversing control of the video image being reproduced, and when the fast-forward button is selected, the display control unit 12 performs fast-forward control of the video image being reproduced. When the frame reversing button is selected, the display control unit 12 performs frame reversing control of the video image being reproduced, and when the frame feed button is selected, the display control unit 12 performs frame feed control of the video image being reproduced.
[0080] When the game date is entered and any narrowing condition is entered, the display control unit 12 narrows retrieval results 56 A displayed in the retrieval result list area 56 and updates display of the retrieval result list area 56 .
[0081] More specifically, when the game date is entered in the game date entry area 54 , the display control unit 12 narrows retrieval results 56 A displayed in the retrieval result list area 56 into a retrieval result 56 A matching the entered game date.
[0082] The narrowing condition is entered in each of narrowing condition areas 55 A, 55 B, 55 C, and 55 D. The narrowing condition area 55 A is selected when the pitching course is entered as the narrowing condition. The narrowing condition area 55 B is selected when the pitch type is selected as the narrowing condition. The narrowing condition area 55 C is selected when the hitting direction is selected as the narrowing condition. The narrowing condition area 55 D is selected when the situation of the count and runner is entered as the narrowing condition.
[0083] When the narrowing condition area 55 A is selected, the display control unit 12 develops and displays, for example, a narrowing condition entry area 551 A for entering the pitching course on the video image reproduction area 57 as illustrated in FIG. 13 . The narrowing condition entry area 551 A includes a specifying component 552 A of a symbol image indicating the pitching course for receiving the pitching course to be entered as the narrowing condition. The display control unit 12 displays the block of the selected pitching course in a display mode different from blocks of pitching courses not selected. In the example of FIG. 13 , the selected block is indicated by halftone dots.
[0084] The narrowing condition entry area 551 A includes a total pitch count display 553 A included in the retrieval result 56 A displayed in the current retrieval result list area 56 . Each block of the specifying component 552 A indicates the number of pitches whose pitching course matches the pitching course indicated by the block out of all pitches included in all retrieval results 56 A indicated in the current retrieval result list area 56 . The narrowing condition entry area 551 A includes a clear button 554 A for clearing the select state of the specifying component 552 A and an OK button 555 A for determining the select state of the specifying component 552 A.
[0085] When the OK button 555 A is selected, the display control unit 12 narrows retrieval results 56 A indicated in the retrieval result list area 56 into a retrieval result 56 A whose pitching course matches the pitching course entered in the specifying component 552 A, and updates display of the retrieval result list area 56 . Then, when any retrieval result 56 A is selected from the retrieval result list area 56 , the display control unit 12 clears display of the narrowing condition entry area 551 A, displays the video image reproduction area 57 , and reproduces a video image indicated by the selected retrieval result 56 A. The display control unit 12 updates the display of the symbol image representing the pitching course in the narrowing condition area 55 A to a display reflecting the condition entered in the specifying component 552 A.
[0086] When the narrowing condition area 55 B is selected, the display control unit 12 develops and displays, for example, a narrowing condition entry area 551 B for entering the pitch type on the video image reproduction area 57 as illustrated in FIG. 14 . The narrowing condition entry area 551 B includes a specifying component 552 B for receiving the pitch type to be entered as the narrowing condition. Similarly with the narrowing condition entry area 551 A, the narrowing condition entry area 551 B includes the total pitch count display 553 B and indicates the number of pitches of each pitch type of the specifying component 552 B. Further, the narrowing condition entry area 551 B also includes a display 556 B in which the number of pitches of each pitch type is graphed. The narrowing condition entry area 551 B further includes a clear button 554 B and an OK button 555 B.
[0087] Display control upon selection of the specifying component 552 B, the clear button 554 B, and the OK button 555 B is the same as in the narrowing condition entry area 551 A. Also, updating of the retrieval result list area 56 and display control after selection of the retrieval result 56 A from the updated retrieval result list area 56 are the same as in the narrowing condition area 55 A.
[0088] When the narrowing condition area 55 C is selected, the display control unit 12 develops and displays, for example, a narrowing condition entry area 551 C for entering the hitting direction on the video image reproduction area 57 as illustrated in FIG. 15 . The narrowing condition entry area 551 C includes a specifying component 552 C of a symbol image representing the hitting direction for receiving the hitting direction to be entered as the narrowing condition. FIG. 15 illustrates an example of the specifying component 552 C in which how the hit ball rises (groundball or fly) may be entered as a specifying condition along with the hitting direction. Similarly with the narrowing condition entry area 551 A, the narrowing condition entry area 551 C includes a total pitch count display 553 C and also indicates the number of pitches in each hitting direction of the specifying component 552 C. The narrowing condition entry area 551 C includes a clear button 554 C and an OK button 555 C.
[0089] Display control upon selection of the specifying component 552 C, clear button 554 C, and OK button 555 C is the same as in the narrowing condition entry area 551 A. Also, updating of the retrieval result list area 56 and display control after selection of the retrieval result 56 A from the updated retrieval result list area 56 are the same as in the narrowing condition area 55 A. A narrowing condition area 55 C of FIG. 16 described below indicates an example where the hitting direction is not entered as the narrowing condition in FIG. 15 .
[0090] When the narrowing condition area 55 D is selected, the display control unit 12 develops and displays, for example, a narrowing condition entry area 551 D for entering the situation of the count and runner on the video image reproduction area 57 as illustrated in FIG. 16 . The narrowing condition entry area 551 D includes a specifying component 552 D of a symbol image representing the situation of the count and runner for receiving the situation of the count and runner to be entered as the narrowing condition.
[0091] FIG. 16 illustrates an example of the specifying component 552 D including a button for entering a situation which is difficult to enter with the symbol image only. For example, a button of “no runner” is used to enter a situation where there is no runner, for distinguishing from the case where the runner's situation is not entered. The same also applies to a “first pitch” button. “Scoring position” makes it possible to enter multiple situations which are difficult to enter with the symbol image, such as a situation where a runner(s) is on the second base, on second and third bases, or on the third base. The same also applies to “two strikes” and “full count” buttons.
[0092] Similarly with the narrowing condition entry area 551 A, the narrowing condition entry area 551 D includes the total pitch count display 553 D. The narrowing condition entry area 551 D includes a clear button 554 D and an OK button 555 D.
[0093] Display control upon selection of the specifying component 552 D, clear button 554 D, and OK button 555 D is the same as in the narrowing condition entry area 551 A. Also, updating of the retrieval result list area 56 and display control after selection of the retrieval result 56 A from the updated retrieval result list area 56 are the same as in the narrowing condition area 55 A.
[0094] Hereinafter, when collectively referred to without distinction, narrowing condition areas 55 A, 55 B, 55 C, and 55 D are merely represented by “narrowing condition area 55 ”. In the same manner, when collectively referred to without distinction, the narrowing condition entry area, specifying component, clear button, and OK button are represented respectively by a reference numeral excluding the sign A, B, C, or D.
[0095] When the personal result tab 33 is selected, the display control unit 12 displays, for example, a personal result screen 60 such as illustrated in FIGS. 17 and 18 on the display device 84 . The personal result screen 60 includes a top page tab 31 , a retrieval and reproduction tab 32 , a personal result tab 33 , and a game log tab 34 . The personal result screen 60 is a screen in a state where the personal result tab 33 is selected. The personal result screen 60 includes a target player entry area 61 and result display areas 62 A to 62 H. The target player entry area 61 is the same as the target player entry area 51 of the retrieval and reproduction screen 50 . Hereinafter, when collectively referred to without distinction, result display areas 62 A to 62 H are merely represented by “result display area 62 ”.
[0096] When the target player is entered in the target player entry area 61 , the display control unit 12 transmits the player ID of the entered player to the distribution server 20 and acquires result information of the player from the result information table 26 of the distribution server 20 . Based on the acquired result information, the display control unit 12 displays the result in the format of a graph or a symbol image in the result display area 62 .
[0097] FIG. 17 illustrates an example of the personal result screen 60 when the target player is a fielder. The result display area 62 A displays a result on “at-bat result breakdown” in a graph format and displays a specifying component 63 A in which each at-bat result as a result item may be selected. The result display area 62 B displays a result on “hitting direction breakdown” in association with each block of the symbol image indicating the hitting direction. The symbol image indicating the hitting direction also functions as the specifying component 63 B in which a block indicating each hitting direction as the result item may be selected. The result display area 62 C displays a result on “course-based batting average” in association with each block of the symbol image indicating the pitching course. The symbol image indicating the hitting direction also functions as a specifying component 63 C in which a block indicating each pitch as the result item may be selected. The result display area 62 D displays a result on “pitch type-based batting average” in a graph format and displays a specifying component 63 D in which each pitch type as the result item may be selected.
[0098] FIG. 18 illustrates an example of the personal result screen 60 when the target player is a pitcher. A result display area 62 E displays a result on “at-bat-based pitch result breakdown” in a graph format and displays a specifying component 63 E in which each at-bat result as the result item may be selected. A result display area 62 F displays a result on “situation based batted average” as a selectable button in association with a symbol image representing each situation. Each button also functions as the specifying component 63 B in which each situation as the result item may be selected. A result display area 62 G displays a result on “course-based batted average” in association with each block of the symbol image indicating the pitching course. The symbol image indicating the pitching course also functions as a specifying component 63 G in which a block indicating each pitching course as the result item may be selected. A result display area 62 H displays a result on “pitch type-based batted average” in a graph format and displays a specifying component 63 H in which each pitch type as the result item may be selected.
[0099] The display control unit 12 may display the graph and symbol image of each result item indicated on each result display area 62 in a different color depending on, for example, whether the result in the result item is not lower than or not higher than a predetermined value. Hereinafter, when collectively referred to without distinction, specifying components 63 A to 63 H are merely represented by “specifying component 63 ”.
[0100] When any result item is selected by operating any specifying component 63 , the display control unit 12 delivers the at-bat result, hitting direction, pitching course, pitch type, or situation of the count and runner corresponding to the selected result item to the acquisition unit 11 as the retrieval condition. Thus, the display control unit 12 acquires the video image file 21 and pitching meta data distributed from the distribution server 20 via the acquisition unit 11 . The display control unit 12 switches the screen to the retrieval and reproduction screen 50 , displays the retrieval condition specified by the specifying component 63 in an entry area of the retrieval condition, and displays the retrieval result list in the retrieval result list area 56 based on the acquired pitching meta data. For example, assume that a 17th block (a second block from the left on the fourth row) is selected from the specifying component 63 C included in the result display area 62 C of the course-based batting average in the personal result screen 60 illustrated in FIG. 17 . In this case, the display control unit 12 displays, in the target player entry area 51 of the retrieval and reproduction screen 50 , information of the player entered in the target player entry area 61 of the personal result screen 60 , and changes display of the narrowing condition area 55 A into a state where the 17th block is entered. Also, all players are entered in the opponent player entry area 52 , all are entered in the pitch/at-bat result entry area 53 , nothing is entered in the game date entry area 54 , and nothing is entered in the narrowing condition areas 55 B, 55 C, and 55 D.
[0101] When the game log tab 34 is selected, the display control unit 12 displays, for example, a game log screen 70 such as illustrated in FIG. 19 on the display device 84 . The game log screen 70 includes a top page tab 31 , a retrieval and reproduction tab 32 , a personal result tab 33 , and a game log tab 34 . The game log screen 70 is a screen in a state where the game log tab 34 is selected. The game log screen 70 includes a game date entry area 71 , a select button 72 , a game overview display area 73 , and a box score display area 74 . The game date entry area 71 may be a text box in which the date may be entered directly into a text box, or may be a pull-down menu in which the date may be selected or in a format in which a calendar is displayed in a separate window. In the case where the calendar is displayed, the opponent team may be indicated in each date field.
[0102] When the game date is entered in the game date entry area 71 , the display control unit 12 transmits the entered game date to the distribution server 20 via the acquisition unit 11 . The distribution server 20 identifies the game based on the entered game date and the team to which the log-in user belongs, extracts game information of the game from the game information table 27 , and extracts pitching meta data of the game from the pitching meta data table 25 . Then, the distribution server 20 transmits the extracted game information and pitching meta data as well as the video image file 21 of the game to the display controller 10 . The display control unit 12 acquires the game information, pitching meta data, and video image file 21 via the acquisition unit.
[0103] The display control unit 12 displays the content of the acquired game information in the game overview display area 73 in a predetermine format. In the example of FIG. 19 , the inning-based score is indicated in a score board format. Based on the acquired pitching meta data, the display control unit 12 generates a box score in which the inning based result of each player arranged in the batting order is represented in a matrix format, and displays in the box score display area 74 in a state where each frame (each at-bat) is selectable.
[0104] When any frame (at-bat) is selected from the box score, the display control unit 12 switches the screen to the retrieval and reproduction screen 50 . Based on the pitching meta data of the selected at-bat, the display control unit 12 displays the retrieval condition in each entry area, and displays information of the selected at-bat in the retrieval result list area 56 as the retrieval result 56 A and reproduces the video image of the at-bat in the video image reproduction area 57 .
[0105] The display controller 10 may be implemented, for example, by a computer 80 illustrated in FIG. 20 . The computer 80 comprises a CPU 81 , a memory 82 as a temporary storage area, and a nonvolatile storage unit 83 . Also, the computer 80 comprises a display devise 84 , a read/write (R/W) unit 85 configured to control reading and writing of data into a recording medium 89 , and a network interface (I/F) 86 connected to the network such as the internet. The CPU 81 , memory 82 , storage unit 83 , display device 84 , R/W unit 85 , and the network I/F 86 are coupled to each other via a bus 87 .
[0106] The storage unit 83 may be implemented by a hard disk drive (HDD), a solid state drive (SSD), a flash memory, or the like. The storage unit 83 as a recording medium stores a display control program 90 configured to cause the computer 80 to function as the display controller 10 . The display control program 90 includes an acquisition process 91 and a display control process 92 .
[0107] The CPU 81 is configured to read out the display control program 90 from the storage unit 83 , develop in the memory 82 , and run processes of the display control program 90 sequentially. The CPU 81 operates as the acquisition unit 11 illustrated in FIG. 1 by running the acquisition process 91 . The CPU 81 operates as the display control unit 12 illustrated in FIG. 1 by running the display control process 92 . Thus, the computer 80 , which has run the display control program 90 , functions as the display controller 10 .
[0108] Functions implemented by the display control program 90 also may be implemented, for example, by a semiconductor integrated circuit, more particularly, by an application specific integrated circuit (ASIC) or the like.
[0109] Next, operation of the display controller 10 according to the embodiment is described. When the application provided by the display controller 10 is activated by the user's log-in with entry of the user ID, a display control processing illustrated in FIG. 21 is performed in the display controller 10 .
[0110] In the step S 11 , the acquisition unit 11 receives the user ID of the entered log-in user, transmits the user ID to the distribution server 20 , and requests top page information including player information, thumbnail image, and pitching meta data relative to the log-in user.
[0111] Next, in the step S 12 , the acquisition unit 11 acquires the top page information transmitted from the distribution server 20 in response to the request. The acquisition unit 11 delivers the acquired top page information to the display control unit 12 .
[0112] Next, in the step S 13 , the display control unit 12 generates the performance card 44 based on the thumbnail image and pitching meta data delivered from the acquisition unit 11 . In this step, in the case where the log-in user is a fielder, the display control unit 12 generates a performance card 44 including the at-bat result of each at-bat in the concerned game. In the case where the log-in user is a pitcher, the display control unit 12 generates a performance card 44 including the opponent team in the concerned game. The display control unit 12 also generates other performance cards 44 based on the top page information such as a performance card 44 accompanied by a message and a performance card accompanied by an attached file.
[0113] Next, in the step S 14 , the display control unit 12 displays, for example, a top page screen 40 such as illustrated in FIG. 9 . More specifically, the display control unit 12 displays, based on the player information of the log-in user delivered from the acquisition unit 11 , player's name, team, position, uniform number, throwing method or hitting method, and picture of the log-in user, in the log-in user display area 41 . The display control unit 12 also displays, based on pitching meta data of the pitch scene for last several games of the log-in user delivered from the acquisition unit 11 , the at-bat result for a predetermined number of at-bats in the descending order from a latest at-bat, in the recent at-bat display area 42 . Further, the display control unit 12 displays performance cards 44 generated in the above step S 13 in the time line display area 43 in the descending order of the date of respective performance cards 44 .
[0114] Next, in the step S 15 , the display control unit 12 determines whether any performance card 44 including the thumbnail image is selected or any at-bat is selected from the recent at-bat display area 42 on the top page screen 40 . When any performance card 44 or a recent at-bat is selected, processing proceeds to the step S 16 , and when neither the performance card 44 nor the recent at-bat is selected, processing proceeds to the step S 19 . In this step, when a performance card 44 not including the thumbnail image is selected, the display control unit 12 performs display control matching the selected performance card 44 .
[0115] In the step S 16 , the display control unit 12 delivers the pitching meta data used for generating the selected performance card 44 or pitching meta data used for displaying the selected recent at-bat information to the acquisition unit 11 as the retrieval condition. Thus, the display control unit 12 acquires the video image file 21 and pitching meta data matching the retrieval condition from the distribution server 20 via the acquisition unit 11 .
[0116] Next, in the step S 17 , the display control unit 12 displays a retrieval condition in each entry area based on pitching meta data corresponding to the selected performance card 44 or recent at-bat. Based on the acquired pitching meta data, the display control unit 12 displays a list of retrieval results 56 A indicating an at-bat corresponding to the selected performance card 44 or a list of retrieval results 56 A indicating an at-bat selected from the recent at-bat display area 42 in the retrieval result list area 56 . Then, processing proceeds to the step S 24 of the retrieval and reproduction screen processing described below, and the display control unit 12 starts reproduction of a video image indicating the pitch scene included in an at-bat corresponding to the selected performance card 44 or the selected recent at-bat in the video image reproduction area 57 .
[0117] Meanwhile, in the step S 19 , the display control unit 12 determines whether the retrieval and reproduction tab 32 is selected on the top page screen 40 . When the retrieval and reproduction tab 32 is selected, processing proceeds to the step S 20 , retrieval and reproduction screen processing described below is performed, and the display control processing ends. When the retrieval and reproduction tab 32 is not selected, processing proceeds to the step S 35 .
[0118] In the step S 35 , the display control unit 12 determines whether the personal result tab 33 is selected on the top page screen 40 . When the personal result tab 33 is selected, processing proceeds to the step S 40 , personal result screen processing described below is performed, and the display control processing ends. When the personal result tab 33 is not selected, processing proceeds to the step S 55 .
[0119] In the step S 55 , the display control unit 12 determines whether the game log tab 34 is selected on the top page screen 40 . When the game log tab 34 is selected, processing proceeds to the step S 60 , game log screen processing described below is performed, and the display control processing ends. When the game log tab 34 is not selected, processing proceeds to the step S 65 .
[0120] In the step S 65 , the display control unit 12 determines whether a command instructing to end the application has been entered, and then determines whether to end the application. When not ending the application, processing returns to the step S 15 , and when ending the application, the display control processing ends.
[0121] Here, the retrieval and reproduction screen processing is described with reference to FIG. 22 .
[0122] In the step S 21 , the display control unit 12 determines whether the retrieval condition is entered in the target player entry area 51 , opponent player entry area 52 , and pitch/at-bat result entry area 53 . When the retrieval conditions are entered in these entry areas, processing proceeds to the step S 22 , and when the retrieval conditions are not entered, processing proceeds to the step S 25 .
[0123] In the step S 22 , the display control unit 12 delivers the target player, opponent player, and pitch/at-bat result entered in the respective entry areas to the acquisition unit 11 as the retrieval conditions. Thus, the display control unit 12 acquires the video image file 21 and pitching meta data matching the retrieval conditions, which are distributed from the distribution server 20 via the acquisition unit 11 .
[0124] Next, in the step S 23 , the display control unit 12 displays, based on the acquired pitching meta data, a list of retrieval results in the retrieval result list area 56 in a state where each of the retrieval results 56 A is selectable.
[0125] Next, in the step S 24 , the display control unit 12 identifies, based on the pitching meta data corresponding to the retrieval result 56 A selected in the retrieval result list area 56 , the selected pitch scene out of the acquired video image file 21 and starts reproduction in the video image reproduction area 57 . In this step, in the case where a retrieval result 56 A is selected in a state where the all-pitches display button 56 C is not selected, the display control unit 12 sequentially reproduces video images representing pitch scenes included in the at-bat indicated by the retrieval result 56 A. In the case where the all-pitches display button 56 C is selected and a specific pitch scene is selected from the developed and displayed retrieval results 56 A, the display control unit 12 reproduces the video image displaying the selected pitch scene.
[0126] In the step S 25 , the display control unit 12 determines whether any narrowing condition area 55 is selected in the retrieval and reproduction screen 50 . When any narrowing condition area 55 is selected, processing proceeds to the step S 26 , and when no narrowing condition area 55 is selected, processing proceeds to the step S 31 . In this step, when the game date is entered in the game date entry area 54 , the display control unit 12 narrows retrieval results 56 A indicated in the retrieval result list area 56 into a retrieval result 56 A matching the entered game date.
[0127] In the step S 26 , the display control unit 12 , for example, develops and displays a narrowing condition entry area 551 corresponding to the selected narrowing condition area 55 on the video image reproduction area 57 as illustrated in FIGS. 13 to 16 .
[0128] Next, in the step S 27 , the display control unit 12 determines whether the OK button 555 is selected with the narrowing condition selected by operating the specifying component 552 in the narrowing condition entry area 551 and thereby determines whether the narrowing condition is entered. When the narrowing condition is entered, processing proceeds to the step S 28 , and when the narrowing condition is not entered, processing returns to the step S 25 .
[0129] In the step S 28 , the display control unit 12 narrows retrieval results 56 A displayed in the retrieval result list area 56 with the narrowing condition entered in the specifying component 552 , and updates display of the retrieval result list area 56 .
[0130] Next, in the step S 29 , the display control unit 12 determines whether any retrieval result 56 A is selected from the updated retrieval result list area 56 . When any retrieval result 56 A is entered, processing proceeds to the step S 30 , and when no retrieval result 56 A is entered, processing returns to the step S 25 . Back to the step S 25 , when another tab or another narrowing condition area 55 is not selected, the select state of the currently selected narrowing condition area 55 is maintained. Specifically, in the step S 26 , display state of the narrowing condition entry area 551 developed on the video image reproduction area 57 is maintained.
[0131] In the step S 30 , the display control unit 12 hides display of the narrowing condition entry area 551 developed and displayed on the video image reproduction area 57 , and displays the video image reproduction area 57 . The display control unit 12 updates display of the narrowing condition area 55 to a display reflecting the condition entered in the specifying component 552 . Then, processing returns to the step S 24 , and reproduction of the video image indicated by the selected retrieval result 56 A is started.
[0132] Meanwhile, in the step S 31 , the display control unit 12 determines whether the top page tab 31 is selected on the retrieval and reproduction screen 50 . When the top page tab 31 is selected, processing returns to the step S 12 of the display control processing ( FIG. 21 ), and the display control unit 12 displays the top page screen 40 . When the top page tab 31 is not selected, processing proceeds to the step S 32 .
[0133] In the step S 32 , the display control unit 12 determines whether the personal result tab 33 or the game log tab 34 is selected on the retrieval and reproduction screen 50 . When the personal result tab 33 or game log tab 34 is selected, processing returns to the step S 19 of the display control processing ( FIG. 21 ). When neither the personal result tab 33 nor the game log tab 34 is selected, processing proceeds to the step S 33 , and the display control unit 12 determines whether to end the application. When not ending the application, processing returns to the step S 21 , and when ending the application, the display control processing ends.
[0134] Next, the personal result screen processing is described with reference to FIG. 23 .
[0135] In the step S 41 , the display control unit 12 transmits the player ID of the player entered in the target player entry area 61 to the distribution server 20 and acquires result information of the player from the result information table 26 of the distribution server 20 . Player information of the log-in user may be established in the target player entry area 61 as a default setting when the screen shifts to the personal result screen 60 .
[0136] Next, in the step S 42 , the display control unit 12 displays, based on the acquired result information, the result represented by a graph or a symbol image in the result display area 62 in a different format depending on whether the entered player is a fielder or a pitcher.
[0137] Next, in the step S 43 , the display control unit 12 determines whether any result item is selected by operating the specifying component 63 of any result display area 62 . When any result item is selected, processing proceeds to the step S 44 , and when no result item is selected, processing proceeds to the step S 46 .
[0138] In the step S 44 , the display control unit 12 delivers the at-bat result, hitting direction, pitching course, pitch type, or count and runner situation corresponding to the selected result item to the acquisition unit 11 as the retrieval condition. Thus, the display control unit 12 acquires the video image file 21 and pitching meta data distributed from the distribution server 20 via the acquisition unit 11 .
[0139] Next, in the step S 45 , the display control unit 12 displays a retrieval condition corresponding to the selected result item in each entry area of the retrieval and reproduction screen 50 . The display control unit 12 displays, based on the acquired pitching meta data, a list of retrieval results 56 A indicating the at-bat corresponding to the selected result item in the retrieval result list area 56 . Then, processing proceeds to the step S 24 of the retrieval and reproduction screen processing ( FIG. 22 ), and the display control unit 12 starts reproduction of a video image representing the pitch scene included in an at-bat corresponding to the selected result item in the video image reproduction area 57 .
[0140] Meanwhile, in the step S 46 , the display control unit 12 determines whether the top page tab 31 is selected on the personal result screen 60 . When the top page tab 31 is selected, processing returns to the step S 12 of the display control processing ( FIG. 21 ), and the display control unit 12 displays the top page screen 40 . When the top page tab 31 is not selected, processing proceeds to the step S 47 .
[0141] In the step S 47 , the display control unit 12 determines whether the retrieval and reproduction tab 32 or the game log tab 34 is selected on the personal result screen 60 . When the retrieval and reproduction tab 32 or the game log tab 34 is selected, processing returns to the step S 19 of the display control processing ( FIG. 21 ). When neither the retrieval and reproduction tab 32 nor the game log tab 34 is selected, processing proceeds to the step S 48 , and the display control unit 12 determines whether to end the application. When not ending the application, processing returns to the step S 41 , and when ending the application, the display control processing ends.
[0142] Next, the game log screen processing is described with reference to FIG. 24 .
[0143] In the step S 61 , the display control unit 12 switches the screen to the game log screen 70 and transmits the game date entered in the game date entry area 71 to the distribution server 20 . Then, the display control unit 12 acquires the game information and pitching meta data of the game identified based on the entered game date and the team to which the log-in user belongs. Also, the game of a team other than the team to which the log-in user belongs may be entered.
[0144] Next, in the step S 62 , the display control unit 12 displays the content of the acquired game information in the game overview display area 73 in a predetermine format. The display control unit 12 displays, based on the acquired pitching meta data, a box score from which each frame (each at-bat) is selectable, in the box score display area 74 .
[0145] Next, in the step S 63 , the display control unit 12 determines whether any frame (at-bat) is selected from the box score. When any at-bat is selected, processing proceeds to the step S 64 , and when no at-bat is selected, processing proceeds to the step S 66 .
[0146] In the step S 64 , the display control unit 12 delivers the pitching meta data of the selected at-bat to the acquisition unit 11 as the retrieval condition. Thus, the display control unit 12 acquires the video image file 21 distributed from the distribution server 20 via the acquisition unit 11 .
[0147] Next, in the step S 65 , the display control unit 12 extracts pitching meta data of the at-bat selected in the above step S 63 from the pitching meta data acquired in the above step S 61 , and displays the retrieval condition based on the extracted pitching meta data in each entry area of the retrieval and reproduction screen 50 . The display control unit 12 displays, based on the extracted pitching meta data, a retrieval result 56 A indicating an at-bat matching the selected at-bat in the retrieval result list area 56 . Then, processing proceeds to the step S 24 of the retrieval and reproduction screen processing ( FIG. 22 ), and the display control unit 12 starts, in the video image reproduction area 57 , reproduction of a video image displaying the pitch scene included in an at-bat selected from the box score.
[0148] Meanwhile, in the step S 66 , the display control unit 12 determines whether the top page tab 31 is selected on the game log screen 70 . When the top page tab 31 is selected, processing returns to the step S 12 of the display control processing ( FIG. 21 ), and the display control unit 12 displays the top page screen 40 . When the top page tab 31 is not selected, processing proceeds to the step S 67 .
[0149] In the step S 67 , the display control unit 12 determines whether the retrieval and reproduction tab 32 or the personal result tab 33 is selected on the game log screen 70 . When the retrieval and reproduction tab 32 or the personal result tab 33 is selected, processing returns to the step S 19 of the display control processing ( FIG. 21 ). When neither the retrieval and reproduction tab 32 nor the personal result tab 33 is selected, processing proceeds to the step S 68 , and the display control unit 12 determines whether to end the application. When not ending the application, processing returns to the step S 61 , and when ending the application, the display control processing ends.
[0150] When any button of the reproduction control button group 58 is selected while the video image is being reproduced in the above step S 24 , the display control unit 12 performs reproduction control matching the selected button. When a message assigning button (not shown) is selected during reproduction of the video image, upon receiving a message from the user, the display control unit 12 assigns the received message to a pitch scene indicated by the video image being reproduced. The message assigned to the pitch scene is not limited to a character message using a text data, but may be a tag indicating approval or sympathy such as a “great!” button widely used in applications of the social networking service (SNS).
[0151] As illustrated above, when a predetermined retrieval condition (narrowing condition) is entered, the display controller according to the embodiment displays an input area for entering the retrieval condition in the video image reproduction area and updates a list of retrieval results according to the entered predetermined retrieval condition. When any retrieval result is displayed, the display controller does not display the input area for entering a predetermined retrieval condition, displays the video image reproduction area and reproduces a video image indicated by the selected retrieval result. During this operation, unselected retrieval results remain displayed in the retrieval result list. Thus, the predetermined retrieval condition may be entered easily, and retrieval results other than those corresponding to a video image being reproduced may be recognized. Thereby, operability in retrieving the video image is improved.
[0152] As the entry state of a predetermined retrieval condition is represented by a symbol image, the entry state of the retrieval condition may be recognized intuitively.
[0153] The number of retrieval results hitting the selection candidate is also displayed for each of retrieval conditions, and may be used as a reference for entering the retrieval condition. Thus, retrieval operability is improved.
[0154] Retrieval results are displayed in the retrieval result list based on the at-bat including a pitch scene matching the retrieval condition. This facilitates checking of the video image of not only pitch scenes matching the retrieval condition, but also pitch scenes included in the same at-bat such as those before and after the pitch scene matching the retrieval condition. Display of the retrieval result is not limited to the at-bat basis, but an inning including the pitch scene matching the retrieval condition may be displayed as one retrieval result. In this case, flow of the attack in the inning including the pitch scene matching the retrieval condition may be checked.
[0155] In this embodiment, the screen may be shifted from each at-bat of the box score indicating results in various situations and game results directly to video image reproduction. Therefore, the result and the video image of each at-bat may be retrieved without paying attention to entering of the retrieval condition.
[0156] In the above embodiment, the video image file is acquired at a timing when a performance card or a recent at-bat on the top page screen, a player or result in the retrieval and reproduction screen, a result item on the personal result screen or an at-bat of the box score on the game log screen is entered. However, the timing of acquiring the video image file is not limited thereto, but may be a timing when the retrieval condition is entered from the retrieval condition list, or a timing when a specific retrieval condition is entered. The video image file may be acquired not based on the video image file, but by capturing a partial image just covering the pitch scene matching the retrieval condition or a partial image including the pitch scene and cut in the unit of at-bat or inning.
[0157] In the above embodiment, the narrowing condition entry area is developed and displayed so as to superpose across the video image reproduction area. However, the narrowing condition entry area may superpose a part of the video image reproduction area. A default retrieval and reproduction screen may display any narrowing condition entry area, and when a retrieval result is selected, a video image reproduction area may be formed in a whole or a part of the narrowing condition entry area, and then, a video image indicated by the selected retrieval result may be reproduced therein.
[0158] In the above embodiment, the display controller generates a performance card therein based on the acquired top page information, but the method of generating the performance card is not limited thereto. The performance card may be generated by the distribution server and transmitted to the display controller.
[0159] In the above embodiment, the retrieval target is each pitch scene of the baseball game video image. However, the retrieval target may be a scene segmented in another unit such as an at-bat unit or inning unit. In this case, similarly with the pitch tag of the above embodiment, a tag may be assigned for a segment of the at-bat and inning, and information on a scene starting from a frame to which the tag is assigned may be prepared as meta data.
[0160] The video image of the retrieval target is not limited to the baseball game video image, but may be a video image assigned with information which is segmented as a scene in a predetermined unit and becomes a selection candidate of the retrieval condition for each scene. Retrieval target is not limited to the video image, but may be a still picture.
[0161] In the above embodiment, the display control program 90 is pre-stored (installed) in the storage unit 83 . However, the display control program 90 may be provided in a form recorded into a removable medium such as CD-ROM and DVD-ROM.
[0162] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
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A non-transitory computer-readable storage medium storing a display control program that causes a computer to execute a process including, in response to a selection of a retrieval item from a plurality of retrieval items, displaying an input area of a retrieval condition corresponding to the selected retrieval item, displaying, in an area different from the input area, a retrieval result retrieved according to a retrieval condition entered in the input area, while maintaining the display of the input area, receiving a selection of any content from a plurality of contents included in the retrieval results, and in response to the selection, displaying an reproduction area that reproduces an image or a video image corresponding to the selected content while maintaining the display of the retrieval results, the reproduction area overlapping at least a part or a whole of the input area.
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TECHNICAL FIELD
[0001] The present invention relates to a technique for genetically producing Wisteria floribunda lectin ( Wisteria floribunda agglutinin, WFA). In addition, the present invention relates to a method for manufacturing other novel modified lectins having sugar-chain recognition activity, which modifies some amino acids.
BACKGROUND ART
[0002] It is known that in a development or differentiation process, a sugar-chain structure reflects a cell state, and thus, is changed. Therefore, a considerable number of differentiation markers or cancer markers, which are now widely used, recognize a sugar chain. For example, a stage specific embryonic antigen 1 (SSEA1) that is a differentiation marker for a developmental state is an antibody to a sugar-chain structure, which is called Lewis X: Galβ1, 4GlcNAc (Fucα1,3)-, and the epitope of CA19-9 that is used as a colon cancer marker for a medical clinical service is a sugar-chain antigen, which is called sialyl Lewis A: SAα2, 3Galβ1, 3GlcNAc (Fucα1,4)-. The sugar chain of the cell surface as described above sensitively reflects a type of cell and a differentiation stage, and thus, it is easy to be a very available candidate for a biomarker.
[0003] As a method for detecting a disease-specific sugar-chain change, lectins, which are a sugar-chain binding protein derived from a plant or fungus, have been used along with an anti-sugar-chain antibody for a long time. When a tissue slice is stained with lectins, it is possible to separately stain the cells having different properties or the cells having different differentiation states, but since the sugar-chain recognizing specificity of the lectin is not clear, it is difficult to specify what kind of the sugar-chain structure is being modified. It is known that wisteria floribunda lectin ( Wisteria floribunda agglutinin, WFA) that is one of plant lectins belongs to Leguminosae lectins, and recognizes a sugar chain including N-acetylgalactosamine (GalNAc) residue. However, the detailed specificity thereof is not clear. Nevertheless, the unique sugar-chain recognition specificity of WFA is used as a marker in various biological fields. For example, in the field of neuroscience, it is known that WFA is a classical marker for staining perineuronal network (PNN) (Non Patent Literature 1), and WFA also stains a normal foveolar epithelial cells of normal gastric mucosa (Non Patent Literature 2). It is also used in the identification method for identifying a prostate cancer and prostatic hypertrophy (Patent Literature 1). In addition, recently, the effectiveness of WFA as a biomarker that is used for diagnosis is highlighted, and thus, it is reported that WFA-positive MUC1 is a bile marker for diagnosing intrahepatic cholangiocarcinoma (Patent Literature 2 and Non Patent Literature 3).
[0004] The isolations of the lectin from wisteria floribunda seeds are reported by a plurality of groups in the 1970s (Table 1).
[0000]
TABLE 1
1
2
3
4
5
auther
Toyoshima
Toyoshima
Kurosawa
Cheung
Kaladas
S.
S.
T.
G.
P. M.
year
1971
1975
1976
1979
1979
name
mitogen
hemag-
agglu-
hemag-
mitogenic
glutinin
tinin
glutinin
lectin
m.w.
32
34
32
28
32
KDa
(mono)
m.w.
67
136
68
57
66
KDa
116
(oligo)
235
oligomer
dimer
tetramer
dimer
dimer
dimer
tetramer
octamer
Ref.
(4)
(5)
(6)
(7)
(8)
[0005] Toyoshima, and others report the isolations and biochemical analysis of two kinds of glycoprotein lectins having different molecular weights (WFM and WFH). Wisteria floribunda Mitogen (WFM) that forms the dimer of 67 KDa, in which the molecular weight of monomer is about 32 KDa, has hemagglutinating activity and phytogen activity (Non Patent Literature 4), but Wisteria floribunda hemaggiutinin (WFH) of 136 KDa that is the tetramer of 35 KDa monomers does not have mitogen activity, but has strong hemagglutination activity and leukoagglutination activity as compared with WFM (Non Patent Literature 5). Meanwhile, the lectin purified by Kurokawa is a 68 KDa glycoprotein formed by the S—S bond of two 32 KDa subunits, and has hemagglutination activity inhibited by GalNAc (Non Patent Literature 6). For these two groups, each of the lectins is purified by a conventional biochemical isolation method of a protein, but for the group of Poretz and others, the homodimer lectin (Non Patent Literature 7) formed by the S—S bond between 28 KDa monomers having hemagglutination activity and the lectin having mitogen activity (66 KDa dimer formed by 32 KDa monomers) are isolated by the affinity to polyleucyl hog gastric mucin (Non Patent Literature 8). These lectins derived from wisteria floribunda seeds that are reported until now have similar property, such as, GalNAc recognition, but have subtle distinctions for amino acid compositions, sugar compositions, molecular weights, and the like. Therefore, it is difficult to determine whether or not the molecules are the same.
[0006] The WFA has grown in biological importance, but the sugar-chain recognition of WFA is not yet clear, and also, it is unclear whether the sugar-chain structures recognized by the WFAs in the neuron and stomach are the same or not. In addition, for the production of WFA, the WFAs that are sold by Vector Laboratory Company or EY Laboratory Company as a reagent are purified from natural wisteria floribunda seeds. Therefore, in order for the stable supply or in order to manage the uniformity among purification lots, it is required to shift the production thereof to the recombinant lectin production by a genetic engineering technique.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: WO 2010/090264 A1
Patent Literature 2: WO 2010/100862 A1
Non Patent Literature
[0000]
Non Patent Literature 1: Hartig, W., Brauer, K., and Bruckner, G. (1992) Neuroreport 3(10), 869-872
Non Patent Literature 2: Ikehara, Y., Sato, T., Niwa, T., Nakamura, S., Gotoh, M., Ikehara, S. K., Kiyohara, K., Aoki, C., Iwai, T., Nakanishi, H., Hirabayashi, J., Tatematsu, M., and Narimatsu, H. (2006) Glycobiology 16(9), 777-785
Non Patent Literature 3: Matsuda, A., Kuno, A., Kawamoto, T., Matsuzaki, H., Irimura, T., Ikehara, Y., Zen, Y., Nakanuma, Y., Yamamoto, M., Ohkohchi, N., Shoda, J., Hirabayashi, J., and Narimatsu, H. (2010) Hepatology 52(1), 174-182
Non Patent Literature 4: Toyoshima, S., Akiyama, Y., Nakano, K., Tonomura, A., and Osawa, T. (1971) Biochemistry 10(24), 4457-4463
Non Patent Literature 5: Toyoshima, S., and Osawa, T. (1975) J Biol Chem 250(5), 1655-1660
Non Patent Literature 6: Kurokawa, T., Tsuda, M., and Sugino, Y. (1976) J Biol Chem 251(18), 5686-5693 Non Patent Literature 7: Cheung, G., Haratz, A., Katar, M., Skrokov, R., and Poretz, R. D. (1979) Biochemistry 18(9), 1646-1650
Non Patent Literature 8: Kaladas, P. N., and Poretz, R. D. (1979) Biochemistry 18(22), 4806-4812
Non Patent Literature 9: Naito, S., Hirai, M. Y., Chino, M., and Komeda, Y. (1994) Plant Physiol 104(2), 497-503
Non Patent Literature 10: Tateno, H., Mori, A., Uchiyama, N., Yabe, R., Iwaki, J., Shikanai, T., Angata, T., Narimatsu, H., and Hirabayashi, J. (2008) Glycobiology 18(10), 789-798
Non Patent Literature 11: Emanuelsson, O., Brunak, S., von Heijne, G., and Nielsen, H. (2007) Nat Protoc 2(4), 953-971
Non Patent Literature 12: Young, N. M., Johnston, R. A., and Watson, D. C. (1991) Eur J Biochem 196(3), 631-637
Non Patent Literature 13: Adar, R., Streicher, H., Rozenblatt, S., and Sharon, N. (1997) Eur J Biochem 249(3), 684-689
SUMMARY OF INVENTION
Technical Problem
[0021] An object of the present invention is to achieve the stable supply and the uniformity among purification lots as well as the detailed elucidation of a sugar-chain recognition of a lectin WFA derived from wisteria floribunda seeds, which exhibits high biological importance. In this regard, another object is to provide recombinant lectin by a genetic engineering technique, and also, to provide WFA modifier having the modified sugar chain that is a recognized object by modifying the relevant recombinant lectin.
Solution to Problem
[0022] The present inventors succeeded in expressing a recombinant lectin in E. coli by cloning the gene encoding a wisteria floribunda lectin in cDNA derived from wisteria floribunda seeds. As a result of analyzing the sugar-chain-binding activity of the recombinant WFA (rWFA), it could be confirmed that the recombinant WFA has the lectin activity that is the same as one available on the market. In addition, they found that when the natural WFA (nWFA) that is a dimer is made to be a monomer by treating the natural WFA with a reducing agent, the sugar-chain recognition specificity thereof is changed, thereby being lectin that recognizes GalNAc terminal sugar chain. In addition, they found that the rWFA prepared by introducing the mutation into the cysteine residue contributing to the formation of dimer specifically recognizes the LDN (GalNAβ1, 4GlcNAc) sugar chain.
[0023] The present inventors completed the present invention by obtaining the above-described knowledge.
[0024] In other words, the present invention includes the following inventions.
[0025] [1] A polypeptide including any one of amino acid sequences represented by the following (1) or (2):
[0026] (1) an amino acid sequence represented by SEQ ID NO. 2, an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added (except the case of deleting all of the amino acid sequences at the positions after 273 rd position or 274 th position); and
[0027] (2) an amino acid sequence, in which any one of the amino acid sequences between N-terminal side and 30 th amino acid sequence of the amino acid sequences disclosed in (1) is deleted,
[0028] the polypeptide having Gal/GalNAc terminal sugar-chain binding activity or GalNAc terminal sugar-chain binding activity.
[0029] [2] A nucleic acid encoding a polypeptide including the base sequence encoding any one of amino acid sequence represented by (1) or (2) disclosed in the above [1] and having Gal/GalNAc terminal sugar-chain binding activity.
[0030] [3] A nucleic acid encoding a polypeptide including any one of the base sequences represented by the following (1) or (2):
[0031] (1) a base sequence represented by SEQ ID NO. 1, or a base sequence that is hybridized with the complementary sequence thereof under a stringent condition, and a base sequence, in which 272 nd position on the amino acid sequence is the codon encoding Cys (except the case of deleting all the base sequences corresponding to the amino acid sequences at the positions after 273 rd position or 274 th position); and
[0032] (2) a base sequence, in which the base sequence corresponding to any one of the amino acid sequences between N-terminal side and 30 th amino acid sequence of the base sequences disclosed in (1) is deleted,
[0033] the polypeptide having Gal/GalNAc terminal sugar-chain binding activity.
[0034] [4] A polypeptide including any one of amino acid sequences represented by the following (1) to (6):
[0035] (1) an amino acid sequence, in which 272 nd amino acid in the amino acid sequence represented by SEQ ID NO. 2 is an amino acid other than Cys;
[0036] (2) an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence disclosed in (1) is/are deleted, substituted, inserted, and added;
[0037] (3) an amino acid sequence, in which the amino acids between C-terminal side and any one of 13 to 15 th amino acids in the amino acid sequence represented by SEQ ID NO. 2 are deleted;
[0038] (4) an amino acid sequence, in which one or several amino acids in the amino acid sequence disclosed in (3) is/are deleted, substituted, inserted, or added;
[0039] (5) an amino acid sequence, in which 272 nd position in the amino acid sequence represented by SEQ ID NO. 2 is alkylated Cys, or an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added; and
[0040] (6) an amino acid sequence, in which any one of amino acid sequences between N-terminal side and 30 th amino acid sequence in any one of the amino acid sequences disclosed in (1) to (5) is deleted,
[0041] the polypeptide specifically recognizing a GalNAc terminal sugar chain.
[0042] [5] A polypeptide including any one of amino acid sequences represented by the following (1) to (5):
[0043] (1) an amino acid sequence, in which an amino acid at 272 nd position in the amino acid sequence represented by SEQ ID NO. 2 is an amino acid other than Cys;
[0044] (2) an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence disclosed in (1) is/are deleted, substituted, inserted, or added;
[0045] (3) an amino acid sequence, in which the amino acids between C-terminal side and any one of 13 to 15 th amino acids in the amino acid sequence represented by SEQ ID NO. 2 are deleted;
[0046] (4) an amino acid sequence, in which one or several amino acids in the amino acid sequence disclosed in (3) is/are deleted, substituted, inserted, or added; and
[0047] (5) an amino acid sequence, in which any one of amino acid sequences between N-terminal side and 30 th amino acid sequence in any one of the amino acid sequences disclosed in (1) to (4) is deleted,
[0048] the polypeptide having LDN-specific sugar-chain recognition ability among GalNAc terminal sugar chains.
[0049] [6] A nucleic acid encoding a polypeptide including the base sequence encoding any one of the amino acid sequences of (1) to (5) disclosed in the above [5], which specifically recognizes a LDN sugar chain.
[0050] [7] A nucleic acid encoding a polypeptide including any one of the base sequences represented by the following (1) to (4):
[0051] (1) a base sequence, in which the codon corresponding to 272 nd amino acid in the base sequence represented by SEQ ID NO. 1 is an amino acid other than Cys;
[0052] (2) a base sequence that is hybridized with the complementary sequence of the base sequence disclosed in (1) under a stringent condition, and a base sequence, in which the codon corresponding to 272 nd amino acid is an amino acid other than Cys;
[0053] (3) a base sequence, in which the base sequence corresponding to any one of amino acids between 3′-terminal side and C-terminal 13 to 15 th amino acids in the base sequence represented by SEQ ID NO. 1 is deleted; and
[0054] (4) a base sequence, in which the base sequence corresponding to any one of amino acid sequences between 5′ side and N-terminal amino acid to 30 th amino acid in any one of the base sequences disclosed in (1) to (3) is deleted,
[0055] the nucleic acid specifically recognizing a LDN sugar chain.
[0056] [8] An expression vector including the nucleic acid disclosed in the above [2], [3], [6], or [7].
[0057] [9] A transformed cell being transformed by using the nucleic acid disclosed in the above [2], [3], [6], or [7].
[0058] [10] A method for preparing a polypeptide having Gal/GalNAc terminal sugar-chain binding activity, GalNAc terminal sugar-chain binding activity or LDN sugar-chain-specific binding activity, the method including performing collection from the culture product obtained by culturing the transformed cells disclosed in the above [9].
[0059] [11] A reagent for specifically detecting a Gal/GalNAc terminal sugar chain or GalNAc terminal sugar chain, the reagent including the polypeptide disclosed in the above [1] or [4].
[0060] [12] A reagent for specifically detecting a LDN sugar chain, the reagent including the polypeptide disclosed in the above [5].
[0061] [13] A method for changing sugar-chain binding activity into GalNAc terminal sugar-chain-specific binding activity, the method including:
[0062] reducing the polypeptide that forms a dimer and includes the amino acid sequence represented by the following (1) or (2) having Gal/GalNAc terminal sugar-chain binding activity:
[0063] (1) an amino acid sequence represented by SEQ ID NO. 2, or an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added; and
[0064] (2) an amino acid sequence, in which any one of the amino acid sequences between N-terminal side and 30 th amino acid sequence of the amino acid sequences disclosed in (1) is deleted; and
[0065] alkylating Cys in the amino acid sequence.
[0066] [14] A method for changing sugar-chain binding activity into LDN sugar-chain-specific binding activity, the method including:
[0067] substituting Cys at 272 nd position in the polypeptide that forms a dimer and includes the amino acid sequence represented by the following (1) or (2) having Gal/GalNAc terminal sugar-chain binding activity by other amino acids:
[0068] (1) an amino acid sequence represented by SEQ ID NO. 2, or an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added; and
[0069] (2) an amino acid sequence, in which any one of the amino acid sequences between N-terminal side and 30 th amino acid sequence of the amino acid sequences disclosed in (1) is deleted; or
[0070] deleting any one of amino acids between C-terminal side and 13 to 15 th amino acids of the amino acid sequence.
Advantageous Effects of Invention
[0071] Since a recombinant WFA (rWFA) can be provided according to the present invention, it is possible to mass-produce a stable-quality WFA lectin having sugar-chain binding activity to a terminal GalNAc residue and Gal residue, like a natural WFA by transformed cells.
[0072] In addition, the WFA monomer prepared by the reduction of the natural WFA, which is provided by the present invention, is a WFA lectin that does not recognize a Gal residue, but specifically recognizes only a GalNAc residue, and the WFA monomer prepared by the cysteine modification of the recombinant WFA (rWFA) is a WFA lectin that specifically recognizes only LDN (GalNAcβ1, 4GlcNAc) sugar chain among the sugar chains having the terminal GalNAc residue. As described above, according to the present invention, it is possible to provide a WFA lectin having modified sugar-chain recognizability that has extremely high usefulness.
BRIEF DESCRIPTION OF DRAWINGS
[0073] FIG. 1 illustrates a base sequence of wisteria floribunda lectin (WFA) gene, and it is expected that the estimated amino acid sequence N-terminal 30 amino acid is a signal sequence. It is expected that N-linked glycosylation is occurred at 146 th asparagine (N). It is considered that there is a possibility of processing C-terminal 13-amino acid.
[0074] FIG. 2 illustrates an amino acid sequence alignment of a leguminous plant lectin.
[0075] FIGS. 3A to 3C illustrate the expression of recombinant WFA (rWFA) in E. coli . FIG. 3A illustrates the construction of plasmid for expressing rWFA and C272A modifier in E. coli . The N-terminal signal sequence was substituted with Hisx6+FLAG sequence, and the gene was inserted into the downstream of pelB leader (secretion signal in periplasm). It was introduced into E. coli BL21-CodonPlus (DE3)-RIPL to obtain transformant. FIG. 3B illustrates the confirmation of recombinant protein expression by an anti-FLAG antibody. As a result, it could be confirmed that the recombinant protein is leaked out in a culture medium other than a periplasm fraction, and thus, exists. FIG. 3C illustrates the purification from the culture supernatant of the recombinant protein using an anti-FLAG antibody column. On the SDS-PAGE under the reducing condition, it was confirmed that the rWFA was observed as a single band at 31 KDa (lane 2) and the WFA available on the market (nWFA) was observed as a single band at 28 KDa (lane 1). Under the non-reducing condition, it was confirmed that the nWFA existed as a single band at about 60 KDa (lane 4) and for the rWFA, about half and half of the dimer and monomer existed (lane 5). Meanwhile, the mutant (C272A) was confirmed as a single band in the size of the monomer under both of the reducing and non-reducing conditions, and thus, it was confirmed that no dimers were formed. From this result, it was clear that Cys at 272 nd position is essential for forming a dimer.
[0076] FIG. 4 illustrates the comparison between the sugar-chain binding activities of a natural WFA and a recombinant WFA using a glycoprotein array. (A) Cy3 label nWFA and rWFA on a glycoprotein array. (B) The verification of sugar-chain recognition specificities of nWFA and rWFA. As a result, the nWFA and rWFA exhibited very similar sugar-chain recognition specificity. Asialo-BSM (bovine submaxillary mucin) exhibited the strongest signal to both of them, and exhibited the binding ability to Gal terminus (asialo-AGP or asialo-TF) along with the sugar chain of GalNAc terminus (A-di, βGalNAc, di-GalNAcβ, LDN, GA2, Tn, Forssman).
[0077] FIGS. 5A and 5B illustrate the expression of the recombinant WFA without C-terminal 13-amino acid. FIG. 5A illustrates the construction of plasmid for expressing the recombinant WFA without C-terminal 13-amino acid. The plasmid for expressing the rWFA without C-terminal 13-amino acid and also with a FLAG tag at N terminus or C terminus was constructed. FIG. 5B illustrates the result of detecting proteins by a Coomassie Brilliant Blue (CBB) staining. When 13-amino acid was deleted, a dimer was hardly formed. The dimer was not detected with the CBB staining.
[0078] FIG. 6 illustrates the result of a GP array for interpreting sugar-chain binding specificity. All of the monomers rWFA that were newly manufactured with E. coli were the lectins that specifically recognize LDN sugar chain.
[0079] FIGS. 7A and 7B illustrate the analysis of the sugar-chain binding activity of a monomer nWFA. FIG. 7A illustrate the construction of nWFA monomer by the reduction. The monomer nWFA was manufactured by reducing the S—S bond contributing to the formation of dimer, and then, performing the alkylation thereof. It was confirmed from the SDS-PAGE under the non-reducing condition that it was a monomer. As illustrated in FIG. 7B , it was confirmed that the monomerized nWFA lost the sugar-chain binding activity to Gal, and thus, specifically recognized GalNAc terminal sugar chain.
[0080] FIG. 8 illustrates the analysis of amino acids of a natural WFA.
[0081] FIG. 9 illustrates staining by various lectins to a natural WFA and rWFA. From the result of lectin blotting using Aleuria Aurantia Lectin (AAL) recognizing fucose, it was confirmed that nWFA was a glycoprotein including the sugar chain that reacts the AAL.
[0082] FIG. 10 illustrates the examples of a glycan array.
[0083] FIG. 11 illustrates the examples of sugar chain types on a glycan array.
[0084] FIGS. 12A and 12B illustrate the purified C272A modified rWFA (with N-glycan) produced by mammalian cells. FIG. 12A illustrates the confirmation of monomer expression by SDS-PAGE (the increase in molecular weight by the influence of sugar chain). FIG. 12B illustrates the analysis of sugar-chain binding specificity by a GP array.
[0085] FIGS. 13A and 13B illustrate the purified C272A, N146Q modified rWFA (without N-glycan) produced by mammalian cells and transformed yeasts. FIG. 13A illustrates the confirmation of monomer expression by SDS-PAGE. FIG. 13B illustrates the analysis of sugar-chain binding specificity by a GP array.
DESCRIPTION OF EMBODIMENTS
1. Wisteria floribunda Lectin (WFA) and Recombinant Modifier Thereof
[0086] 1-1. Lectin Derived from Wisteria Floribunda Seeds Cloned According to the Present Invention and Recombinant Lectin Thereof
[0087] In the present invention, we succeeded in cloning the genes of lectin derived from wisteria floribunda seeds that were used as a tissue marker for a long time and in manufacturing recombinant lectin.
[0088] The cloned gene encodes new protein composed of 286 amino acids ( FIG. 1 , SEQ ID NOS. 1 and 2), and the expected molecular weight of a maturing lectin domain (aa31-273) without the domain having the processing possibility of C-terminus or signal sequence of N-terminus was 26.6 KDa. Since the possibility of adding one N-glycan in the seeds is considered, about 1.3 KDa is added to the expected molecular weight thereof, and thus, the expected molecular weight is to be 27.9 KDa. Therefore, the expected molecular weight is well matched with the molecular weight of the WFA lectin available on the market. In addition, from the result of analyzing the shotgun peptide sequence of the WFA available on the market by a LC/MS method, the lectin which is cloned this time is almost the same as the WFA available on the market, but when being compared with the WFA available on the market, which is purified from natural substances, it is the polypeptide having C-terminus added with 13-amino acid. For other leguminosae lectins, such as, peanut agglutinin (PNA), there is reported the example having C-terminus that is processed (Non Patent Literature 12). Therefore, it is considered that for the natural WFA, C-terminal 13-amino acid is subjected to a processing.
[0089] In other words, the present invention provides new recombinant WFA (rWFA) that is called a “precursor WFA” before being subjected to the processing of C-terminal amino acid in a natural WFA. In the present invention, “rWFA” is added with 13-amino acid at the C-terminal side as compared with a natural WFA, and also, indicates “recombinant WFA” with or without N-terminal 30-amino acid that is a signal sequence.
[0090] The molecular weight and amino acid composition of the lectin which is cloned this time are similar to those of the lectin reported by Kurokawa (Non Patent Literature 6) or Cheung (Non Patent Literature 7) until now, but are not completely matched with the molecular weight and amino acid composition of wisteria floribunda lectin WFH (Non Patent Literature 5), in which the purification thereof is reported by Toyoshima, and others. These differences may be generated by the analyzing method differences, and also, it can be considered that there is a possibility that more lectins or mitogens exist in the wisteria floribunda seeds.
[0091] 1-2. Dimer Ability of Recombinant Lectin and Modifier Thereof
[0092] This time, the rWFA that is expressed in E. coli is, unlike a natural WFA (nWFA), a precursor without a sugar chain and with 13-amino acid at the C-terminal side, at least. However, it was confirmed that the rWFA has the same sugar-chain recognition activity as the natural WFA. It is expected that the natural WFA has one N-glycan, and as for the amino acid sequence thereof, the only N-glycan (N-linked sugar chain) binding position is asparagine (N) at 146 th position. However, since the rWFA without a sugar chain has the activity, it is considered that the sugar chain is unnecessary for the activity. It is reported that the addition of N-glycan in soybean agglutinin (SBA) that belongs to a leguminosae lectin family does not contribute to the activity or the formation of polymer (Non Patent Literature 13), and the same tendency even in WFA is confirmed. The nWFA forms a dimer by a disulfide bond, but it is strongly considered by determining the amino acid sequence that the only cysteine at 272 nd has the possibility of contributing to the formation of disulfide bond. When the WFA is expressed in the periplasm of E. coli , the about half of the rWFA purified from a nutrient medium may form a dimer, but C272A that is a modifier, in which the cycteine is substituted by alanine, does not form a dimer. Therefore, it is considered that the above-described possibility is the right one. When it is assumed that 13-amino acid at C-terminus is subjected to a processing during the maturing process of protein, the maturing nWFA proteins almost form a dimer at C-terminus. We attempted the expression of the recombinant lectin, in which 13-amino acid at C-terminus is excluded in advance, but the expression amount thereof is quite the same as the case of including 13-amino acid. Nevertheless, the dimer is almost not formed. For this reason, it is considered that after forming a dimer during the maturing process of WFA protein, the processing at C-terminus may occur.
[0093] In addition, even though the cysteine is not included in the lectin sequence belonging to Leguminosae, such as, SBA or PNA, when being expressed in E. coli , the polymer may be formed by a noncovalent bond, but in the case of WFA, the point capable of forming a disulfide bond because of including cysteine is different from the above-described lectin. There is cysteine at the position close to WFA in the sequence of Sophora Japonica agglutinin (SJA) ( FIG. 2 ), and thus, it is also suggested that the cysteine has the possibility of contributing to the formation of dimer.
[0094] 1-3. WFA Monomerization and Sugar-Chain Binding Specificity in Recombinant Lectin Modifier
[0095] This time, the rWFA is expressed and purified in E. coli , and the sugar-chain binding specificity thereof is investigated using a glycan array. As a result, the rWFA exhibits the sugar-chain binding specificity to Gal/GalNAc, like the natural one. However, C272A that is a modifier of the cysteine residue at 272 nd contributing to the formation of dimer or nWFA-RCA that is a monomer prepared by performing the reduction and alkylation of nWFA that is a dimer has the changed sugar-chain binding specificity. Therefore, it is considered that the formation of dimer through the cysteine is important to recognize Gal/GalNAc by a nature-derived WFA. Meanwhile, the nWFA-RCA that is the monomer of nWFA specifically recognizes the sugar-chain of GalNAc terminus, but does not recognize the sugar chain of Gal terminus other than that. It is reported by Kurokawa and others that the binding activities of a monomer and a dimer to GalNAc are not changed (Non Patent Literature 6). However, it is clear from these results that the recognition activity is not changed to the overall sugar chain including GalNAc at terminus as well as GalNAc. The cysteine residue exists at almost C-terminus of the maturing WFA, and thus, it is expected that it is not involved in the formation of sugar-chain binding pocket of lectin. However, the dimer is formed, and thus, Gal terminal sugar-chain binding activity is generated. It is unclear that the nWFA recognize GalNAc and Gal as the same pocket, or new sugar-chain recognition site for recognizing Gal by forming a dimer is generated. However, when the structure thereof is confirmed by crystallizing it and analyzing the structure through an X-ray structure analysis, the molecule mechanism of sugar-chain binding may be confirmed.
[0096] In addition, the rWFA C272A surprisingly has very limited sugar-chain binding activity, that is, LDN-specific recognition activity. As illustrated in FIG. 3C , when the rWFA is purified from a culture medium, about half thereof forms a dimer through a cysteine residue, and thus, like the nWFA, exhibits Gal/GalNAc binding activity. The modification of cysteine residue of rWFA C272A does not affect the sugar-chain binding pocket, but does not form a dimer during the synthesizing process of protein, and thereby, there may be the possibility of affecting the structure and stability other than the pocket.
[0097] This time, the gene encoding the WFA lectin is isolated, and then, the recombinant WFA having modified amino acid sequence is genetically manufactured. As a result, it is confirmed that a plurality of sugar-chain binding specificities of WFA converge in LDN. It is exhibited that there is the possibility of solving the extensive sugar-chain recognition specificity that is one of lectin defects by the gene modification. It is expected that since there is the possibility of changing the recognition specificity with an evolution engineering technique by using them for a mold in future, a useful modified lectin may be developed as a diagnosis biomarker or tissue and a cell marker for various diseases in future.
2. As for WFA Gene of the Present Invention and Expression Product Thereof
[0098] The new recombinant WFA (rWFA) provided in the present invention includes any one of the amino acid sequences represented by the following (1) or (2), and also, may be expressed as the polypeptide having a binding activity to GalNAc terminal sugar chain along with Gal terminal sugar chain (hereinafter, referred to as Gal/GalNAc terminal sugar-chain binding activity) or GalNAc terminal sugar-chain binding activity. Here, the rWFA forming a dimer has Gal/GalNAc terminal sugar-chain binding activity, and the rWFA of monomer has LDN-specific binding activity among the GalNAc terminal sugar chains.
[0099] (1) The amino acid sequence represented by SEQ ID NO. 2, or the amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added (except the case of deleting all of the amino acid sequences at the positions after 273 rd position or 274 th position), and
(2) The amino acid sequence, in which one amino acid sequence among the amino acid sequences between N-terminal side and 30 th amino acid sequence of the amino acid sequences represented by the above (1) is deleted.
[0101] In addition, the several numbers of the amino acids means 1 to 20, preferably 1 to 10, and more preferably 1 to 5.
[0102] Therefore, the base sequence of rWFA gene may be a base sequence encoding the amino acid sequence disclosed in the above (1) or (2), but the base sequence may be also represented by the following (3) or (4).
[0103] (3) The base sequence represented by SEQ ID NO. 1 or the base sequence that is subjected to a hybridization with a complementary sequence thereof under a stringent condition, and also, the base sequence, in which the position at 272 nd on the amino acid sequence is a codon encoding Cys (except the case of deleting all of the base sequences corresponding to the amino acid sequences at the positions after 273 rd or 274 th position), and
[0104] (4) The base sequence, in which the base sequence corresponding to any one of amino acid sequence among the amino acid sequences between N-terminal side and 30 th amino acid sequence in the base sequences represented by the above (3) is deleted.
[0105] In addition, the stringent condition means a shrinkage condition that can be subjected to the hybridization of the sequence having 85% or more, preferably 90% or more, and more preferably 95% or more of the identity for a general hybridization method.
[0106] When the expression vector for expressing the WFA gene of the present invention is constructed, a secretion signal is particularly unnecessary, but in order to purify an expressed product, it is easy and efficient that the secretion signal is allowed to be secreted in a nutrient medium, and then, the nutrient medium is purified, and thereby the secretion signal is preferably added.
[0107] The transformed host for preparing the recombinant WFA of the present invention may be eukaryotic cells, such as, mammal cells, insect cells, plant cells, or yeast. However, the fucose-containing sugar chain that is originally included in a natural substance is not involved in the sugar-chain recognition function of WFA lectin, and thus, it is preferable to use prokaryotic cell host, such as, E. coli.
[0108] For the obtained recombinant WFA, a general purifying method may be applied, and for example, the purification using a general tag or an affinity column to the sugar-chain ligand may be used for purifying the recombinant WFA.
[0109] The recombinant WFA (rWFA) obtained according to the present invention forms a monomer along with a dimer in the almost same amount as the natural WFA. The dimerized rWFA exhibits the extensive sugar-chain recognition ability that is almost the same as the natural WFA, but the rWFA in the state of monomer has LDN-specific sugar-chain recognition ability such as the recombinant WFA modifier to be described below. The relevant rWFA monomer may be isolated from a dimer by the technique, such as, a gel filtration.
3. Recombinant WFA Modifier Having LDN-Specific Sugar-Chain Recognition Ability in the Present Invention
[0110] (3-1) Recombinant WFA Modifier by Introducing the Mutation into Cys at 272 nd Position of rWFA (c272rWFA)
[0111] In the present invention, “LDN-specific sugar-chain recognition ability” means a sugar-chain recognition ability that does not recognize Gal terminal sugar chain, but recognizes only the case of having GalNAcβ1, 4GlcNAc sugar chain among GalNAc terminal sugar chains. Specifically, it is possible to detect the LDN sugar-chain marker that is known to be expressed at a normal stomach epithelial cell, and the like.
[0112] Among the recombinant WFA modifiers having LDN specificity that is developed in the present invention, the recombinant WFA modifier by the mutation introduction into Cys at 272 nd position (C272 modified rWFA) has the amino acid sequence, in which Cys at 272 nd position is substituted by other amino acid, and does not form a dimer. As a result, it is a WFA lectin having LDN-specific sugar-chain recognition ability, and may be expressed as follows.
[0113] A polypeptide having any one of amino acid sequence represented by the following (1) to (3):
[0114] (1) an amino acid sequence, in which the amino acid at 272 nd position in the amino acid sequence represented by SEQ ID NO. 2 is an amino acid other than Cys;
[0115] (2) an amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence represented by the above (1) is/are deleted, substituted, inserted, or added; and
(3) an amino acid sequence, in which any one of the amino acid sequences between N-terminal side and 30 th amino acid in the amino acid sequence represented by the above (1) or (2) is deleted, and
[0117] the polypeptide having LDN-specific sugar-chain recognition ability.
[0118] In addition, the several numbers means 1 to 20, preferably 1 to 10, and more preferably 1 to 5.
[0119] In addition, it may be any amino acids as long as the amino acid at 272 nd position in the amino acid sequence of (1) is the amino acids other than Cys, but the amino acids having a reacting group, such as Ala or Gly are preferable, and Ala is more preferable.
[0120] In addition, the relevant recombinant WFA modified gene (C272rWFA gene) may be the base sequence encoding the amino acid sequences represented by the above (1) to (3), but the base sequence may be represented by any one of the base sequences represented by the following (4) to (6).
[0121] (4) the base sequence, in which the codon corresponding to the amino acid at 272 nd position in the base sequence represented by SEQ ID NO. 1 is the amino acids other than Cys,
(5) the base sequence that is subjected to the hybridization with the complementary sequence of the base sequence represented by the above (4) under a stringent condition, and the base sequence, in which the codon corresponding to the amino acid at 272 nd position is the amino acids other than Cys, (6) the base sequence, in which the base sequence corresponding to any one of amino acid among the amino acids between 5′ side and N-terminal amino acid to 30 th amino acid in the base sequence represented by the above (4) or (5) is deleted.
[0124] In addition, the stringent condition means a shrinkage condition, in which the sequence having 85% or more, preferably 90% or more, and more preferably 95% or more of the identity in a general hybridization method can be hybridized.
[0125] In addition, according to the present invention, for the recombinant WFA modifier (C272 modified rWFA), further, the recombinant WFA modifier of C272, N146Q modified rWFA, in which asparagines at 146 t11 position that is a N-type sugar-chain binding position is modified with glutamine (N146Q), is manufactured. It is confirmed that the relevant modifier does not have a sugar chain and has the same “LDN-specific sugar-chain recognition ability” as the case of the recombinant WFA modifier (C272 modified rWFA) expressed in E. coli , even in the case of using yeast or mammal cells other than bacteria, such as, E. coli as a host.
[0126] (3-2) Recombinant WFA Modifier (rWFA Delta) by the Deletion of C-Terminal Side
[0127] The dimer at C272 position is not formed by deleting the partial amino acid sequence at C-terminal side of the dimer recombinant WFA, and thus, it is possible to perform the monomerization. The sugar-chain recognition ability of the monomer is the same as C272 rWFA, and the LDN sugar-chain specificity is exhibited. Even though the natural WFA does not have the amino acid sequence (275 th to 293 rd positions) after 13 th position of C-terminal side of the recombinant WFA, the dimer by the S—S bond at 272 nd Cys position is formed. For this reason, it may be assumed that the proteins in the natural WFA are biosynthesized, and 13-amino acid part at 275 th position or less after forming the dimer is processed. Meanwhile, it is confirmed that in the case of the recombinant WFA, in which the amino acids from C-terminus to 13 th amino acid are deleted in advance, 272 nd Cys corresponding to 15 th position loses the ability of forming a dimer; thus, is subjected to the monomerization; and also, achieves LDN sugar-chain specificity that is the equivalent to C272rWFA ( FIGS. 3A to 3C ). It is considered that when 272 nd Cys and the neighboring amino acid sequence thereof are removed, the monomer having the same LDN sugar-chain specificity may be formed. In other words, when it is the recombinant WFA modifier without the amino acids between C-terminal side to 13 to 15 th amino acids, it may be the recombinant WFA modifier forming the monomer that exhibits the LDN sugar-chain specificity that is the same as C272 rWFA.
[0128] In the present invention, the recombinant WFA without C-terminal amino acid sequence may be also called a C-terminal side deleted recombinant WFA modifier, “rWFA delta”.
[0129] “The rWFA delta” may be expressed as follows.
[0130] A polypeptide having any one of amino acid sequence represented by the following (1) or (2):
[0131] (1) the amino acid sequence, in which any one of the amino acids from C-terminal side thereof to 13 to 15 th amino acids in the amino acid sequence represented by SEQ ID NO. 2 is deleted; and
[0132] (2) the amino acid sequence, in which one or several amino acids in the amino acid sequence represented by (1) is/are deleted, substituted, inserted, or added,
[0133] the polypeptide having LDN-specific sugar-chain recognition ability.
[0134] “The rWFA delta” gene may be the base sequence encoding the amino acid sequence represented by the above (1) or (2), but the base sequence may be expressed by any one of the base sequences represented by the following (3) to (6).
[0135] (3) the base sequence, in which the base sequence corresponding to any one of amino acid from 3′ terminal side to C terminus to 13 to 15 th amino acids in the base sequence represented by SEQ ID NO. 1 is deleted, and
[0136] (4) the base sequence that is hybridized with the complementary sequence of the base sequence represented by the above (3) under a stringent condition.
[0137] (3-3) Expression of Recombinant WFA Modifier Gene
[0138] When the vector including the recombinant WFA modifier gene (C272rWFA or rWFA delta gene) of the present invention is constructed, in order to easily detect C272rWFA or rWFA delta, the tag for detecting, such as, FLAGtag may be bound at an upstream or downstream side. The LDN-specific sugar-chain recognition ability thereof is not changed by binding this tag.
[0139] The host and expression vector for expressing the recombinant WFA modifier (C272A rWFA or rWFA delta) of the present invention are the same as the recombinant WFA, and the purification method thereof is the same.
4. As for Reducing WFA Monomer in the Present Invention
[0140] In the present invention, “the reducing WFA monomer” indicates monomerized WFA by performing the alkylation treatment of the cysteine residue after reducing to the recombinant WFA or natural WFA of the dimer.
[0141] At this time, as the reducing method or alkylation method, it is possible to apply the conventional techniques one by one or at the same time. Typically, after performing the reducing treatment using dithiothreitol (DTT), the technique of reacting with an alkylating agent, such as, iodoacetamide may be applied.
[0142] Any kinds of reducing WFA monomers specifically recognize only GalNAc terminal sugar chain, because it does not have the sugar-chain recognition ability to Gal terminal sugar chain.
[0143] In other words, a method for preparing the WFA monomer lectin that specifically recognizes GalNAc terminal sugar chain according to the present invention may be expressed as follows.
[0144] A method of preparing a WFA monomer lectin that specifically recognizes a GalNAc terminal sugar chain, in which a polypeptide dimer having Gal/GalNAc terminal sugar-chain binding activity, encoding the amino acid sequence represented by the following (1) or (2), is incubated under a reducing condition, and then, at the same time, the alkylation treatment of a sulfur-containing functional group is applied.
[0145] (1) The amino acid sequence represented by SEQ ID NO. 2, or the amino acid sequence, in which one or several amino acids at the positions other than 272 nd position in the amino acid sequence is/are deleted, substituted, inserted, or added, and
(2) an amino acid sequence, in which any one of the amino acid sequences between N-terminal side and 30 th amino acid sequence of the amino acid sequences represented by the above (1) is deleted.
[0147] The “WFA monomer lectin” that specifically recognizes GalNAc terminal sugar chain is firstly provided by the present invention.
5. Method for Detecting LDN Sugar-Chain Marker and Kit Therefor
[0148] Various recombinants WFA provided in the present invention are useful as a lectin for detecting Gal/GalNAc or GalNAc sugar-chain marker, and may be used for the method of detecting LDN sugar-chain marker, which is conventionally used for a natural WFA.
[0149] The rWFA that is called a precursor WFA of a natural WFA has the sugar-chain recognition ability that is the same as the natural WFA, and also, can be massively produced as a WFA gene expression product in a character transformed E. coli . Therefore, the rWFA may be used as the substitute of the natural WFA for detecting the conventional Gal/GalNAc terminal sugar chain. The monomer rWFA that is obtained by isolating the relevant rWFA through a gel filtration, and the like specifically recognizes LDN sugar chain.
[0150] In addition, according to the present invention, when the WFA monomer lectin that specifically recognizes GalNAc terminal sugar chain, and especially, C272 modifier WFA that specifically recognizes only LDN sugar chain among the GalNAc terminal sugar chains are used for the method of detecting LDN sugar-chain marker for detecting a normal gastric mucous membrane area, which is performed using the conventional natural WFA such as the monomer rWFA of C-terminal side, it is possible to exhibit higher specificity.
[0151] Specifically, it is considered that it is used as a probe for detecting a small cell carcinoma of lung or an endocrine tumor, in which high expression of LDN sugar chain is expected.
DESCRIPTION OF EMBODIMENTS
[0152] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to Examples.
[0153] In addition, the technical terms used for the present invention have the meanings that are generally understood by a person who is skilled in the prior art, unless otherwise indicated. In addition, the contents disclosed in Patent Literatures or patent application specifications are incorporated into the description of the present specification.
[0154] (Reagents Used for Examples)
[0155] The purified wisteria floribunda lectin (nWFA) was purchased from Vector Lab Inc. (Burlingame, Calif., USA). An anti-FLAG-tag M2-HRP conjugate was purchased from Sigma-Aldrich Co. LLC. (St. Louis, Mo., USA).
Example 1
Cloning of wisteria floribunda lectin gene
[0156] (1-1) Preparation of cDNA Library
[0157] The total RNA of wisteria floribunda seed was extracted using the method of Naito, and others (Non Patent Literature 9). About 150 mg of the seeds were broken in a liquefied nitrogen, the broken product of the seed was mixed with an extraction buffer (1 M Tris-HCl pH 9.0/1% SDS) and PCI (phenol:chloroform:isoamyl alcohol of 25:24:1), and then, was suspended until being in the latex state. After performing the centrifuge, PCI was added in the supernatant thereof, was violently stirred, and then, was centrifuged. Since then, the supernatant was collected, 1/10 times volume of 3 M Na-acetate and 3 times volume of ethanol were added to the supernatant, and then, the supernatant thus obtained was cooled at −80° C. to precipitate the nucleic acids thereof. After performing air-drying, the precipitated nucleic acids were dissolved in H 2 O, and then, 4 M of LiCl was added thereto. After remaining the reactant thus obtained on an ice overnight, the reactant was centrifuged to collect the total RNA as a precipitate. Poly (A) RNA was prepared using NucleoTrap® mRNA (MACHEREY-NAGEL GmbH & Co. KG, Duren, Germany), and was provided for a cDNA synthesis. The cDNA library used for gene cloning was manufactured using Marathon® cRNA Amplification Kit (Clontech, Mountain View, Calif., USA) from mRNA of wisteria floribunda seeds prepared as described above.
[0158] (1-2) Gene Cloning
[0159] The gene encoding wisteria floribunda lectin was cloned from the cDNA derived from wisteria floribunda seeds. Using the amino acid sequence (Accession: P05046) of soybean agglutinin (SBA) that was leguminosae lectin as Query, the blast search was performed to obtain three kinds of the amino acid sequences of lectin-typed protein in Genbank DB ( Robinia pseudoacacia , Accession: BAA36414, Sophora japonica , Accession: AAB51441 , Cladrastis kentukea , Accession: AAC49150). The nucleic acid sequences of these three kinds of lectin-typed proteins ( Robinia pseudoacacia , Accession: AB012633, Sophora japonica , Accession: 063011 , Cladrastis kentukea , Accession: U21940) were aligned, and then, the following two primers for PCR were designed in the well stored area.
[0000]
(SEQ ID NO. 3)
Fwd-1:
5′-CTCTTGCTACTCAACAAGGTGAA-3′
(SEQ ID NO. 4)
Rev-1:
5′-CAACTCTAACCCACTCCGGAAG-3′
[0160] The PCR reaction (94° C., 1 min, (30 cycles of 94° C., 1 min—60° C., 30 sec—68° C., min), 68° C., 1 min) of cDNA derived from wisteria floribunda seeds as a template was performed with KOD-plus-(TOYOBO, Osaka, Japan). As a result, about 650 bp DNA fragment was amplified. The fragment was sub-cloned in pCR-Blunt II-TOPO (invitrogen, Carlsbad, Calif., USA), and the nucleic acid sequence thereof was determined with 3130xl Genetic Analyzer (Applied Biosystems, CA). As a result, it was new nucleic acid sequence.
[0161] The sequence was a partial sequence, and did not have the N-terminus and C-terminus of open leading frame, and thus, the sequence of the total length was determined with a RACE (Rapid Amplification of cDNA End) method. For 3′-RACE method, the PCR reaction was performed using the above Fwd-1 and the following Adapter primer-1 (Clontech) primers (35 cycles of 94° C. 1 min, 60° C. 30 sec, and 68° C. 1 min),
[0000]
Adapter Primer-1:
(SEQ ID NO. 5)
5′-CCATCCTAATACGACTCACTATAGGGC-3′
[0162] Since then, with the amplified nucleic acid as a template, the nested PCR was performed using the above Fwd-2 and the following Adapter primer-2 (Clontech) primers.
[0000]
Adapter Primer-2:
(SEQ ID NO. 6)
5′-ACTCACTATAGGGCTCGAGCGGC-3′
[0163] As a result of determining the sequence of about 700 by DNA fragment thus obtained, the gene sequence including a stop codon was obtained.
[0164] In addition, for the unknown part of 5′ sequence, the following Rev-2 and Rev-3 were designed, and a 5′-Race method was performed using the above Adapter primer-1 and Adapter primer-2 to determine the sequence of total length.
[0000]
(SEQ ID NO. 7)
Rev-2:
5′-ACTATAGACTGGTTCGCCGTCC-3′
(SEQ ID NO. 8)
Rev-3:
5′-GGGTGAGTTGTAAATGCCCTGA-3′
[0165] (1-3) Analysis of Sequence of Lectin Gene
[0166] The new lectin gene that was subjected to the cloning in wisteria floribunda seeds was composed of 861 by ORF, and thus, encoded the proteins composed of 286 amino acids ( FIG. 1 ). The new amino acid sequence had the motif sequence that was stored in leguminosae lectin, and had the homogeny of 62.8% of Robinia pseudoacacia, 60.9% of Cladrastis kentukea , and 60.6% of Sophora japonica , which were used for query, respectively. In addition, it had the homogeny of 58.5% of soybean lectin SBA ( Glycine max : P05046) and 39.5% of peanut bean lectin PNA ( Arachis hypogaea : P02872), respectively ( FIG. 2 ). There was one N-bound sugar-chain addition region in the sequence, and thus, it was confirmed that one cystein residue was existed around C-terminus. The total length-amino acid sequence determined was analyzed using a signal sequence prediction program SignalP4.0 (Technical University of Denmark, http://www.cbs.dtu.dk/services/SignalP/Non Patent Literature 11). As a result, it was predicted that the hydrophobic amino acid cluster at N-terminal side was a signal sequence, and the cutting between 30 th serine and 31 st lysine was performed.
Example 2
Expression of Recombinant Lectin (rWFA) in Transformed E. coli
[0167] (2-1) Transformation of E. coli by Lectin Gene
[0168] In order to express the wisteria floribunda lectin cloned in Example 1 in E. coli , amino acids 31 to 286 residues to be predicted as the lectin activity area were incorporated into a downstream of pelB leader of pET20b (Merck4Biosciences, Darmstadt, Germany) that was a periplasm expression vector after adding His Tag and FLAG Tag at the N-terminus thereof.
[0169] In addition, the DNA fragment encoding WFA was amplified with the following WFA-HisFL-Fwd and WFA-Rev, and then, was inserted into NcoI-XhoI region of pET20b.
[0000]
WFA-HisFL-Fwd:
(SEQ ID NO. 9)
5′-
ccatggGACATCATCATCATCATCACCTCGACTACAAGGACGACGATGAC
AAGGGCAAGCTTGCGGCCGCGAATTCAAAAGAAACAACTTCCTTTGTC-
3′
WFA-Rev-1:
(SEQ ID NO. 10)
5′-ctcgagTTAGATGGAACCGCGCAGAA-3′
[0170] The manufactured plasmid for expression was transformed into E. coli BL21-CodonPlus (DE3)-RIPL (Agilent Technologies, CA); the expression of transformant was induced by adding 100 mM isopropyl β-D-thiogalactopyranoside (IPTG) in the final concentration according to a manual; and then, the shaking culture was performed for one night at 25° C.
[0171] (2-2) Expression and Purification of rWFA in E. coli
[0172] The extraction of periplasm fraction was performed according to pET System Manual 11 th edition (Merck4Biosciences). The extraction of soluble protein was performed using BugBuster (Merck4Biosciences). After inducing the expression, the expression of the recombinant protein was confirmed in the periplasm fraction ( FIGS. 3A and 3 B). In addition, since it was confirmed that it existed in the soluble fraction, and was leaked in a nutrient medium (lanes 5 and 7 in FIG. 3B ), the recombinant protein was purified in a FLAG Tag rather than in the nutrient medium that was easily handled. The purification thereof was performed using DDDDK-tagged Protein PURIFICATION GEL (MBL, Nagoya, Japan), and the recombinant protein was eluted with DDDDK elution peptide. Finally, the eluted protein was concentrated with Amicon Ultra 3K (Merck Millipore, MA).
[0173] As a result of performing the purification of recombinant lectin by the affinity to a FLAG tag, the recombinant WFA (rWFA) was subjected to a SDS-PAGE under a reducing condition, and then, was obtained by purifying one protein of about 31 KDa that was stained with CBB staining (lane 2 in FIG. 3C ).
Example 3
Confirmation of Identity Between Recombinant WFA (rWFA) and Natural WFA (nWFA) on the Sequence
[0174] (3-1) Analysis of Amino Acids of Nature-Derived WFA Lectin (nWFA)
[0175] The analysis of amino acids of nature-derived wisteria floribunda lectin (purchased from Vector Lab) was performed using an amino acid sequencer, Procise492HT (Applied Biosystems, CA) and a mass spectrometer, LTQ Orbitrap Velos ETD (Thermo Fisher Scientific, Waltham, Mass., USA). About 2 μg of lectin protein was treated at 100° C. for 5 minutes in the sample buffer with 2-mercaptoethanol, and then, was subjected to a SDS-PAGE. About 28 KDa band was collected and then reduced-alkylated. The trypsin digestion thereof was performed to decompose the band into the peptide fragments. After concentrating, the analysis of LC/MS was performed using LTQ Orbitrap Velos ETD, and then, the amino acid sequence of constitution peptides was identified.
[0176] (3-2) Comparison Result of rWFA and nWFA Sequences
[0177] It was confirmed whether or not the estimated amino acid sequence of ORF that was determined by cloning wisteria floribunda lectin gene in Example 1 was the same as the WFA lectin available on the market, which was purified from nature. In (3-1), by an amino acid sequencer, the sequence that was the 31 st lysine of the N-terminal side or less of nWFA (Vector Lab) was identified. In addition, the nWFA was digested with trypsin like (3-1), and the amino acid sequence of constitution peptide was determined by a LC/MS method. As a result, 93% of trypsin digestion peptide obtained from the lectin available on the market was equal to the lectin sequence (except a signal sequence part) that was newly determined ( FIG. 8 ).
[0178] In addition, 13-amino acid of C-terminus of WFA-ORF amino sequence determined in Example 1 was not included in the peptide obtained from a nature-derived lectin, and it was considered that there was the possibility of processing it during the maturing process of protein.
[0179] (3-3) Comparisons of Dimer Formation Abilities and Molecular Weights by SDS-PAGE
[0180] The recombinant WFA (rWFA) purified in Example 2 (2-2) was observed as a single band of 31 KDa on a SDS-PAGE under a reducing condition (lane 2 in FIG. 3C ).
[0181] Meanwhile, the natural WFA (nWFA) available on the market was confirmed as a single band of about 28 KDa that was smaller than that of the recombinant WFA (lane 1 in FIG. 3C ). As a result of performing a SDS-PAGE under a non-reducing condition except 2-mercaptoethanol, it was suggested that nWFA was detected as a single band of about 60 KDa, thereby forming a dimer with the S—S bond (lane 4 in FIG. 3C ). Meanwhile, the rWFA could be detected at both of dimer molecular weight and monomer molecular weight under a non-reducing condition (lane 5 in FIG. 3C ).
Example 4
Production of nWFA Monomer by Reducing Nature-Derived WFA
[0182] (4-1) Confirmation of Sugar Chain Including Fucose, which was Included in Nature-Derived WFA
[0183] It was reported that the natural WFA (nWFA) has a sugar chain including fucose, and thus, the lectin blotting was performed using Aleuria Aurantia Lectin (AAL) recognizing fucose. As a result, it was confirmed that the nWFA was a glycoprotein including a sugar chain that reacted to AAL ( FIGS. 5A and 5B ).
[0184] (4-2) Production of nWFA Monomer by nWFA Reduction
[0185] The reduction of nature-derived WFA was performed using dithiothreitol (DTT). 10 μL of 1 M DTT was added to 1 mL of 1 mg/mL (100 mM Tris, pH 8.5) nWFA, and then, the reduction reaction was performed at room temperature for 4 hours. Subsequently, 25 μL of 1 M iodoacetamide was added, and then, the alkylation reaction was performed at dark room temperature for 30 minutes. As a result, the nWFA was reduced, and then, cysteine that contributed to the formation of dimer was alkylated to be S-carboxy amide methyl cysteine, and the nWFA was to be a monomer. After the reaction, the extra reagents were removed through ultra-filtration (Amicon 3K, Millipore).
Example 5
Production of Modifier Lectin C272A
[0186] (5-1) Expression of Modifier Lectin C272A by E. coli
[0187] In Example 3 (3-3), since the nWFA was a single band of 28 KDa in the state of non-reduction and a single band of 60 KDa in the state of reduction, it was considered that the nWFA formed a dimer. However, the rWFA was a single band of 31 KDa in the state of reduction, but under the non-reducing condition, the bands were detected at both of the molecular weight of dimer and molecular weight of monomer ( FIG. 3C ).
[0188] In order to verify whether the cysteine residue was involved in forming a dimer, the modifier (C272A), in which only cysteine at 272 nd position in the rWFA amino acid sequence was substituted by alanine was manufactured, and then, was expressed in E. coli.
[0189] The modifier lectin C272A was manufactured using PCR with the primers of C272A-Fwd and C272A-Rev.
[0000]
C272A-Fwd:
(SEQ ID NO. 11)
5′-AGCAGTGATGATGCCAACAACTTGCAT-3′
C272A-Rev:
(SEQ ID NO. 12)
5′-ATGCAAGTTGTTGGCATCATCACTGCT-3′
[0190] The FLAG-Tag WFA was manufactured by inserting the fragments amplified using the following N-FLAG and C-FLAG PCR primers, respectively, into EcoRI-XhoI region of pET20b.
[0191] N-FLAG:
[0000]
WFA-FLAG-Fwd:
(SEQ ID NO. 13)
5′-
gaattcAGACTACAAGGACGACGATGACAAGAAAGAAACAACTTCCTTTG
T-3′
WFA-Rev-2:
(SEQ ID NO. 14)
5′-ggcctcgagTTAGTTGCAATCATCACTGCTAGGATCT-3′,
C-FLAG:
WFA-Fwd-1:
(SEQ ID NO. 15)
5′-ggaattcaAAAGAAACAACTTCCTTTGT-3′
WFA-FLAG-Rev:
(SEQ ID NO. 16)
5′-
ctcgagTTACTTGTCATCGTCGTCCTTGTAGTCGTTGGCATCATCACTGC
TAGGATCT-3′
[0192] (5-2) Examination of Dimer Formation Ability by SDS-PAGE
[0193] For C272A purified with a FLAG tag, the band of 28 KDa, a monomer size was confirmed on a SDS-PAGE under both of the reducing and non-reducing conditions (lanes 3 and 6 in FIG. 3C ). Since the modifier of cysteine did not form a dimer, it was clear that the S—S bond through cysteine was essential for forming a dimer.
Example 6
Analysis of Sugar-Chain Binding Activity of Recombinant Lectin (rWFA)
[0194] (6-1) Measurement of Sugar-Chain Binding Activity
[0195] The sugar-chain binding activity of recombinant lectin was analyzed using a complex sugar micro array developed by The National institute of Advanced Industrial Science and Technology (AIST) (Non Patent Literature 10). The lysine residue of recombinant lectin was labeled with Cy3 (GE Healthcare, Buckinghamshire, UK), and then, was provided to the micro array. The Cy3 signal was measured using Glycostation Reader 1200 (GP BioSciences, Yokohama, Japan).
[0196] (6-2) Sugar-Chain Recognition Activity of rWFA
[0197] Whether or not the rWFA manufactured in E. coli has sugar-chain recognition activity was analyzed using a sugar chain•glycoprotein array. The nWFA and rWFA that were labeled with Cy3 were provided to a glycoprotein array. As a result, the nWFA and rWFA exhibited very similar sugar-chain recognition specificity ( FIG. 4 ). One that exhibited strongest signal to both of them was Asialo-BSM (bovine submaxillary mucin). In addition, as expected above, it exhibited the affinity even to the GalNAc terminal sugar chain (A-di, βGalNAc, di-GalNAcβ, LDN, GA2, Tn, Forssman). Furthermore, it exhibited the affinities to asialo-AGP, asialo-TF, asialo-TG, asialo-FET, or the like. From these results, it was clear that the rWFA expressed in E. coli had the sugar-chain recognition activity that was the same as the natural WFA.
[0198] (6-3) Deletion of C-Terminal 13-Amino Acid, and Effect of 272 nd Cys Residue on Sugar-Chain Recognition Activity
[0199] Subsequently, in order to investigate the effect of C-terminal 13-amino acid, the rWFA without 13-amino acid was manufactured, and then, the sugar-chain recognition activity thereof was investigated ( FIGS. 5A and 5B ). Three kinds of modifiers, such as, the modifier prepared by deleting 13-amino acid and also adding a FLAG-tag to N-terminus (rWFA N-FLAG), the modifier prepared by modifying Cys 272 with Ala in the same design (C272A N-FLAG), and the modifier that was modified, in which the position of FLAG tag (C272A C-FLAG) was changed into C-terminus, were expressed in E. coli ( FIG. 5A ).
[0200] As a result of subjecting the purified recombinant lectin on a SDS-PAGE, the rWFAs N-FLAG without 13-amino acid at C-terminus did not mostly form a dimer, and were electrophoresed on the molecular weight of monomer even under the 2ME-non-reducing condition (lane 6 in FIG. 5B ).
[0201] In addition, as predicted, it was confirmed that the modified C272A N-FLAG was a monomer, and also, the C272A C-FLAG with the tag at C-terminus was expressed on the monomer (lanes 7 and 8 in FIG. 5B ).
[0202] Three kinds of purified monomer recombinant lectins were labeled with Cy3, and then, the sugar-chain binding activities thereof were verified with a sugar-chain protein array. As a result, all three kinds of them did not mostly have the sugar-chain recognition activity that was confirmed in nWFA, but only had the binding activity to LDN (GalNAcβ1, 4GlcNAc) and asialo-BSM. Here, as compared with the LDN binding activity, the degree of the binding activity to asialo-BSM was insignificant, and thus, the relevant binding activity might be expressed as “LDN-specific binding activity”. In addition, the modified C272A WFA having 13-amino acid at C-terminus (lanes 3 and 6 in FIG. 3C ) had the same binding activities to LDN and Asialo-BSM, that is, “LDN-specific binding activity” (data is not shown).
[0203] (6-4) Dimer formation ability and effect on sugar-chain binding specificity by the existence of C-terminal 13-amino acid
[0204] The rWFA, in which the C-terminal 13-amino acid to be predicted to be processed was deleted and a FLAG tag was added to N-terminus or C-terminus, was expressed. As a result, one without 13-amino acid did not mostly form a dimer. The dimer was not detected by a CBB staining, but was only detected by the western blotting of anti-FLAG antibody. The C272A did not form a dimer like Example 5 ( FIGS. 3A to 3C ). The sugar-chain binding specificity was examined using the purified rWFA ( FIG. 6 ).
[0205] (6-5) Explanation of cause, in which monomer recombinant only recognizes LDN and asialo-BSM
[0206] The rWFA that recognized only LDN and asialo-BSM was a monomer lectin. Therefore, in order to verify whether the difference between the sugar-chain binding activities of nWFA and rWFA occurs by the monomerization or the recombinant expression, the sugar-chain recognition activity of the nWFA monomer having the cysteine residue alkylated after being reduced, which was prepared in Example 4, was reviewed ( FIG. 7A ).
[0207] As a result of analyzing it with a glycoprotein array, the reduced WFA (nWFA-RCA) exhibited the sugar-chain recognition, which was different from nWFA and rWFA. The nWFA-RCA had the significantly decreased or deleted binding activities to Lac, Lec, LN, Asialo-FET, Asialo-AGP, Asialo-TF, Asialo-TG, Tn, Asialo-GP, BSM, and αGal, but the binding activity thereof to the sugar chain having GalNAc at the non-reducing terminus, such as A-di, bGalNAc, di-GalNAcβ, LDN, GA2, Forssman, and Asialo-BSM, has changed little ( FIG. 7B ).
[0208] From these results, it was confirmed that the nWFA in a monomer could specifically bind to the sugar chain of GalNAc terminus. In other words, it was confirmed that the dimerized natural WFA could bind to the sugar chain of Gal terminus as well as the sugar chain of GalNAc terminus.
Example 7
Production of C272A Modified Lectin in Human Culture Cells
[0209] The nucleic acid encoding WFA having C272A mutation disclosed in Example (5-1) was introduced into the human culture cells (HEK293T cell line) for reviewing the production of modified lectin in a host other than E. coli . In detail, the gene encoding C272A modified rWFA was inserted into a pFLAG-CMV3 expression vector (Sigma), and then, was transfected into HEK293T cells.
[0210] After the gene was introduced into the cells, the cells were cultured in a DMEM medium including 10% bovine serum for 48 hours, and then, the modified lectin was purified from the culture supernatant thereof using an anti-FLAG antibody column (Sigma). As a result, the modified lectin was detected as a single band around about 35 KDa, but there was not observed the increase in molecular weight by the sugar chain ( FIG. 12A ). It was labeled with Cy3, and was provided to a glycoprotein array. As a result, the binding specificity (LDN and asialo-BSM) like the modified lectin manufactured in E. coli was confirmed ( FIG. 12B ).
Example 8
Production of C272A, N146Q Modified Lectin in Human Culture Cells
[0211] In this Example, the gene encoding C272A, N146Q modified rWFA of C272A modified lectin that did not give a sugar chain even though it was a eukaryotic cell, in which 146 th asparagine that was only sugar-chain binding region to the C272A modified rWFA was substituted by glutamine (N146Q), was prepared.
[0212] The relevant gene encoding C272A, N146Q modified rWFA was inserted into a pFLAG-CMV3 expression vector (Sigma) that was used in Example 7, and then, was gene-introduced into a human culture cell (HEK293T cell line).
[0213] The transformed cells were cultured in the same method as Example 7 to perform the expression induction, and then, the culture supernatant thereof was collected. Using the same purification method as Example 7, the purified C272A, N146Q modified lectin was obtained.
[0214] The modified lectin purified from the culture supernatant was detected as a single band of about 33 KDa (Left side in FIG. 13A ). It was labeled with Cy3, and then, was provided to a glycoprotein array. As a result, it was confirmed that the binding specificity (LDN and asialo-BSM) like the modified lectin produced in E. coli was exhibited (Upper side in FIG. 13B ).
[0215] The C272A modified rWFA that was expressed in E. coli , in which the sugar chain could not be added, had LDN-binding activity, and thus, even though it could be sufficiently expected that the addition of sugar chain did not affect the sugar-chain recognition ability, this point became clear from the above result.
Example 9
Production of C272A, N146Q Modified Lectin in Yeast
[0216] As for a yeast (methanol-assimilating yeast Ogataea minuta TK10-1-2 cell line), the gene encoding the C272A, N146Q modified rWFA disclosed in Example 8 was inserted into a pOMEA1-10H3F expression vector having His and FLAG tag to transform O. minuta TK10-1-2 cell line.
[0217] The transformed yeast was cultured in 200 ml of YPD medium (2% Peptone, 1% Yeast Extract, and 2% glucose) at 30° C. for 2 days. After removing the culture supernatant by centrifuge, 200 ml of BMMY medium (2% Peptone, 1% Yeast Extract, 1.34% Yeast Nitrogen Base w/o amino acids, 1% MeOH, and 100 mM potassium phosphate buffer (pH6.0)) was added thereto, and then, was re-suspended. Since then, it was further cultured at 30° C. for 2 days, and then, the expression of Endo-Om was performed. After collecting the culture supernatant, the dialysis thereof was performed in TBS buffer (1.24 g of tris(hydroxymethyl)aminomethane, 6.27 g of tris(hydroxymethyl)aminomethane hydrochloride, and 8.77 g/L of sodium chloride). After performing the dialysis, the lectin solution was provided in a HisTrap HP column (GE Healthcare), and then, was washed with a TBS buffer including 50 mM imidazole. Since then, the gradient elution was performed with a TBS buffer including 500 mM imidazole to elute proteins. The fraction including Endo-Cm eluted from the column was ultrafiltration-concentrated with Amicon Ultra (10,000 MWCO, Millipore), and also, was substituted with the TBS buffer to be the purified C272A, N146Q modified lectin.
[0218] The modified lectin purified from the yeast culture supernatant could be detected as a single band of about 34 KDa (Right side in FIG. 12A ). It was labeled with Cy3, and then, was provided to a glycoprotein array. As a result, it was confirmed that the binding specificity (LDN and asialo-BSM) like the modified lectin prepared in E. coli and culture cells was exhibited (Bottom side in FIG. 12B ).
[Sequence-Free Text]
[0219] SEQ ID NO. 1: wisteria floribunda lectin (g)
SEQ ID NO. 2: wisteria floribunda lectin (a)
SEQ ID NO. 3: Fwd-1
SEQ ID NO. 4: Rev-1
SEQ ID NO. 5: Adapter Primer-1
SEQ ID NO. 6: Adapter Primer-2
SEQ ID NO. 7: Rev-2
SEQ ID NO. 8: Rev-3
SEQ ID NO. 9: WFA-HisFL-Fwd
SEQ ID NO. 10: WFA-Rev-1
SEQ ID NO. 11: C272A-Fwd
SEQ ID NO. 12: C272A-Rev
SEQ ID NO. 13: WFA-FLAG-Fwd (N-FLAG)
SEQ ID NO. 14: WFA-Rev-2 (N-FLAG)
SEQ ID NO. 15: WFA-Fwd-1 (C-FLAG)
[0220] SEQ ID NO. 16: WFA-FLAG-Rev (C-FLAG)
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[Problem] The purpose of the present invention is to stably supply high-quality and highly uniform Wisteria floribunda agglutinin (WFA) that recognizes biologically important sugar-chain markers, to elucidate the sugar-chain recognition activity in detail, and to furthermore increase the specificity of the sugar-chain recognition activity. [Solution] The present invention involves the development of a technique for cloning genes for coding Wisteria floribunda agglutinin (WFA) and producing recombinant WFA having the same sugar-chain recognition activity as natural WFA from transformed bacteria. Natural WFA is reduced to thereby manufacture a reduced WFA monomer for specifically recognizing terminal GalNAc residue. A recombinant monomer WFA for recognizing LDN (GalNAcβ1, 4GlcNAc) sugar chain, which is important as a diagnostic marker among sugar chains having a terminal GalNAc residue, is manufactured by introducing cysteine mutation to recombinant WFA or by C-terminal-side amino acid deletion.
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INTRODUCTION
[0001] Printing mechanisms often include an inkjet printhead which is capable of forming an image on many different types of media. The inkjet printhead ejects droplets of colored ink through a plurality of orifices and onto a given media as the media is advanced through a printzone. As used herein, the term “media” may refer to one or more medium. The printzone is defined by the plane created by the printhead orifices and any scanning or reciprocating movement the printhead may have back-and-forth and perpendicular to the movement of the media. Methods for expelling ink from the printhead orifices, or nozzles, include piezo-electric and thermal techniques. For instance, two earlier thermal ink ejection mechanisms are shown in U.S. Pat. Nos. 5,278,584 and 4,683,481, both assigned to the present assignee, the Hewlett-Packard Company.
[0002] A printing mechanism may have one or more inkjet printheads, corresponding to one or more colors, or “process colors” as they are referred to in the art. Many inkjet printing mechanisms contain a service station for maintenance of the inkjet printheads. The service station may include scrapers, ink-solvent applicators, primers, and/or caps to help keep the nozzles from drying out during periods of inactivity.
[0003] Some service stations are configured to minimize space and/or reduce cost by moving substantially in-line with the motion of the printheads, and by being activated into a servicing position by a carriage transporting the printheads. One such in-line service station can be found in U.S. Pat. No. 6,315,386. While inline service stations can save space, the process of activating the service station into the servicing position can create an undesirable amount of noise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIGS. 1 - 3 schematically illustrate one embodiment of a printing mechanism having an in-line service station.
[0005] [0005]FIG. 4 illustrates one embodiment of actions which adapt a servicing force for a service station.
[0006] [0006]FIG. 5 illustrates another embodiment of actions which adapt a servicing force for a service station.
[0007] [0007]FIG. 6 illustrates one embodiment of velocity and pulse width modulation curves for a printhead carriage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] [0008]FIG. 1 schematically illustrates one embodiment of a printing mechanism, here shown as an inkjet printer 20 , which may be used for printing on a variety of media, such as paper, transparencies, coated media, cardstock, photo quality papers, and envelopes in an industrial, office, home or other environment. A variety of inkjet printing mechanisms are commercially available. For instance, some of the printing mechanisms that may embody the concepts described herein include desk top printers, portable printing units, wide-format printers, hybrid electrophotographic-inkjet printers, copiers, video printers, and facsimile machines, to name a few. For convenience the concepts introduced herein are described in the environment of an inkjet printer.
[0009] While it is apparent that the printer components may vary from model to model, the typical inkjet printer 20 includes a printer controller 22 that receives instructions from a host device, such as a computer or personal data assistant (PDA) (not shown). A screen coupled to the host device may also be used to display visual information to an operator, such as the printer status or a particular program being run on the host device. Printer host devices, such as computers and PDA's, their input devices, such as a keyboards, mouse devices, stylus devices, and output devices such as liquid crystal display screens and monitors are all well known to those skilled in the art.
[0010] A print media handling system (not shown) may be used to advance a sheet of print media 24 through a printzone 26 for printing. A carriage guide rod 28 is positioned within the inkjet printer 20 to define a scanning axis 30 . In the case of FIG. 1, the scanning axis 30 is parallel to the X-axis. The guide rod 28 slidably supports an inkjet carriage 32 for travel back and forth, reciprocally, across the printzone 26 . A carriage drive motor 34 is coupled to the carriage 32 , and may be used to propel the carriage 32 in response to an input 36 received from the controller 22 . To provide carriage position feedback information 38 to controller 22 , a conventional encoder strip (not shown) may be extended along the length of the printzone 26 and over a servicing region 40 . An optical encoder reader may be mounted on the back surface of printhead carriage 32 to read position information provided by the encoder strip, for example, as described in U.S. Pat. No. 5,276,970, also assigned to the Hewlett-Packard Company, the present assignee. Such an encoder is schematically illustrated as encoder block 42 in FIG. 1. Position feedback 38 may be provided by other techniques familiar to those skilled in the art, for example, by connecting an encoder to the motor 36 , rather than to the printhead carriage 32 as illustrated in this embodiment.
[0011] In the printzone 26 , the media sheet 24 receives ink 44 from an inkjet cartridge, such as a black ink cartridge 46 or a color ink cartridge 48 . The illustrated printer 20 uses replaceable printhead cartridges where each cartridge has a reservoir that carries the entire ink supply as the printhead reciprocates across the printzone 26 . As used herein, the term “cartridge” may also refer to an “off-axis” ink delivery system, having main stationary reservoirs (not shown) for each ink located in an ink supply region. In an off-axis system, the cartridges may be replenished by ink conveyed through a flexible tubing system from the stationary main reservoirs which are located “off-axis” from the path of printhead travel, so only a small ink supply is propelled by carriage 32 across the printzone 26 . Other ink delivery or fluid delivery systems may also employ the systems and methods described herein, such as cartridges which have ink reservoirs that snap onto permanent or semi-permanent printheads.
[0012] The illustrated black ink cartridge 46 has a printhead 50 , and color ink cartridge 48 has a tri-color printhead 52 which ejects cyan, magenta, and yellow inks. In response to firing command control signals delivered from the controller 22 to the printhead carriage 32 , the printheads 50 , 52 selectively eject ink 44 to form an image on a sheet of media 24 when in the printzone 26 . The printheads 50 , 52 are thermal inkjet printheads, although other types of printheads may be used, such as piezoelectric printheads.
[0013] Between print jobs, the inkjet carriage 32 moves along the carriage guide rod 28 to the servicing region 40 where a service station 54 may perform various servicing functions known to those in the art, such as, priming, scraping, and capping for storage during periods of non-use to prevent ink from drying and clogging the inkjet printhead nozzles. For simplicity, the service station 54 is illustrated as a capping station.
[0014] The service station 54 has a frame 56 which defines a series of guide slots 58 . Two guide slots 58 are located on the front of the frame 56 as visible in FIG. 1. Two similar guide slots 58 are located on the back of the frame 56 (not shown). A maintenance sled 60 is supported by the frame 56 on guide posts 62 which protrude from the maintenance sled 60 to slidably engage the guide slots 58 . A biasing spring 64 couples the sled 60 to the frame 56 , biasing the sled 60 in a negative X-axis direction and a negative Y-axis direction. As illustrated in FIG. 1, the maintenance sled 60 is in a retracted position. The maintenance sled 60 has a black printhead cap 66 and a color printhead cap 68 which are moveably coupled to the sled 60 , and biased in a positive Y-axis direction by capping springs 70 . The maintenance sled 60 also has an activation arm 72 protruding upwards from the sled 60 . The frame 56 is supported and held in a fixed position by a chassis (not shown) of the inkjet printer 20 .
[0015] As FIG. 2 illustrates, the printhead carriage 32 may be moved along the carriage guide rod 28 in the positive X-axis direction until the carriage 32 contacts the activation arm 72 . After contacting the activation arm 72 , as the carriage 32 continues to move in the positive X-axis direction, the guide posts 62 move within the guide slots 58 , first up a ramp portion 74 and towards a top of the ramp portion 76 . The activation arm 72 is constructed to contact the carriage 32 when the printhead caps 66 , 68 are horizontally aligned (along the X-axis) with their corresponding printheads 50 , 52 . While there is horizontal alignment between the printhead caps 66 , 68 and the printheads 50 , 52 when the carriage 32 initially contacts the activation arm 72 , the caps 66 , 68 do not contact the printheads 50 , 52 until the carriage 32 continues to move the maintenance sled 60 further upwards as defined by the motion allowed by the guide slots 58 and the guide posts 62 . When the guide posts 62 move up the ramp 74 and approach the top of the ramp 76 , the caps 66 , 68 will engage their respective printheads 50 , 52 . As the carriage 32 continues to move along the carriage guide rod 28 in the positive X-axis direction, the maintenance sled 60 moves upwards relative to the printheads 50 , 52 , causing the capping springs 70 to compress. Since the printheads 50 , 52 are held in place by the printhead carriage 32 , the force in the positive Y-axis direction provided by the capping springs 70 tends to lift the carriage against the guide rod 28 , and may even cause a slight deflection of the guide rod 28 .
[0016] As the printhead carriage 32 continues to move in the positive X-axis direction, the guide posts 62 reach the top of the ramp 76 . At this point, the capping force exerted by the capping springs 70 remains relatively constant, since the capping springs 70 will not compress further. As FIG. 3 illustrates, the printhead carriage 32 can continue moving in the positive X-axis direction until the guide posts 62 reach the top end 78 of the guide slots 58 . When the guide posts 62 have reached the top end 78 of the guide slots 58 , the maintenance sled 60 is considered to be in a servicing position. In other embodiments, the maintenance sled 60 can reach the servicing position when the guide posts 62 have not reached the top end 78 of the guide slots, for example, in a situation where there is an alternate physical stop which the carriage 32 or the ink cartridges 46 , 48 contact to prevent further motion and therefore determine the servicing position.
[0017] When the printhead carriage 32 is moved back in the negative X-axis direction, the biasing spring 64 maintains contact between the activation arm 72 and the carriage 32 . As the carriage 32 moves in the negative X-axis direction, the guide posts 62 move within the guide slots 58 , back past the top of the ramp 76 and down the ramp portion 74 until the maintenance sled 60 is in the retracted position once again. When the maintenance sled 60 reaches the retracted position, the carriage 32 will disengage the activation arm 72 as the carriage is moved further in the negative X-axis direction.
[0018] Given the torque capabilities of the motor 34 which is moving the printhead carriage 32 , and the mass of the ink cartridges 46 , 48 , as well as the carriage 32 itself, it is often not possible for the carriage 32 to slowly engage the activation arm 72 and move the maintenance sled 60 from the retracted position to the servicing position in a slow and steady manner. Instead, it is often necessary to move the printhead carriage 32 a distance away from the service station 54 in the negative X-axis direction, and provide an input 36 to the motor 34 which will accelerate the printhead carriage 32 to a desired velocity before contacting the activation arm 72 . The momentum achieved by doing this is sufficient to overcome the forces associated with the guide posts 62 climbing the ramp 74 , compressing the capping springs 70 , and lifting the carriage guide rod 28 . Since these forces may vary over time depending on the age of the system and the manufacturing tolerances involved, it may be desirable to use a “full force push” by the printhead carriage 32 to guarantee that the maintenance sled 60 reaches the servicing position under all conditions, regardless of the amount of ink in the ink cartridges, the number of ink cartridges present, positioning differences due to manufacturing tolerances, varying friction in the system from one inkjet printer 20 to another, or varying friction in the system over time due to use, aging, contamination, or part wear. The momentum achieved by a full force push is empirically determined to be adequate to move the maintenance sled 60 into the servicing position, regardless of the variable conditions which may exist. A “full force” push or a “full pushing force” is not necessarily as hard as the printhead carriage 32 can push. Rather, a full force push, as used herein and in the claims, is a push determined to be adequate to allow the maintenance sled 60 to reach the servicing position under a number of variable conditions. While this is a robust solution, there will be situations where the full force push will effectively slam the carriage 32 into the activation arm 72 , slam the caps 66 , 68 into the printheads 50 , 52 , and/or slam the guide posts 62 into the top end 78 of the guide slots 58 , creating undesirable noise from the inkjet printer 20 , or possibly unseating one or more of the ink cartridges 46 , 48 from the carriage 32 .
[0019] [0019]FIG. 4 illustrates one embodiment of actions which adapt a servicing force for a service station. Based on feedback from the encoder 42 , the controller 22 is able to know the position of the printhead carriage 32 as it moves along the carriage guide rod 28 in the positive and negative X-axis directions. Using a full force push as described above, the controller can measure and store 80 the servicing position in terms of carriage position. After measuring and storing 80 the servicing position in terms of carriage position by using a full force push, the carriage disengages 82 the service station, and the controller reduces 84 the pushing force to a minimum value and engages the service station. Recall that the force of the push is determined in part by the velocity of the printhead carriage 32 when it contacts the activation arm 72 . The velocity of the printhead carriage 32 is a function of the input 36 to the motor 34 , the resistance to movement provided by the mass of the carriage 32 and the ink cartridges 46 , 48 , and the distance the carriage 32 has to travel before contacting the activation arm 72 . The motor input 36 will determine the power given to the motor 34 , and therefore will affect the acceleration of the printhead carriage 32 . If the carriage 32 is allowed to accelerate over a larger distance, it will reach a higher velocity, and will be capable of pushing the activation arm 72 with a greater force. Therefore, to reduce the pushing force to a minimum value, the controller can reduce the level of motor input 36 and/or start the carriage 32 closer to the activation arm so that the carriage 32 will not accelerate to as high of a velocity as it can with the full force push. The minimum force can be calculated or empirically determined based on best case scenarios. Best case scenarios for a minimum force include a broken-in motor, nearly empty print cartridges, cap springs 70 which have a low force, and well-lubricated parts with minimal friction. As used herein and in the appended claims, the term “minimal force” or “minimum value” does not necessarily refer to an absolute lowest amount or value. Rather, “minimum force” and/or “minimum value” can also refer to a reduced or smaller value as compared to another value. For example, a minimum force can be any force which is less than the full force, and not necessarily the lowest possible force.
[0020] During the reduced force push, the controller monitors 86 the position of the printhead carriage. The carriage position is compared 88 to the stored servicing position. The controller then determines 90 if the servicing position has been reached based on the encoder position. If the servicing position has not been reached 92 , the carriage is disengaged 94 from the service station, and the pushing force is increased 96 by a desired increment and the service station is engaged by the carriage. The controller again monitors 86 the position of the carriage, and compares 88 the position of the carriage to the stored servicing position. If the servicing position has been reached 98 , the force used during the push is stored 100 as an adaptive servicing force for use with subsequent servicing events.
[0021] The controller may monitor 102 to see if both printheads have been removed. If both printheads have been removed 104 , the pushing force is set 106 to a minimum empty carriage value. The carriage can then be monitored 86 during subsequent pushes, and the push force increased 96 if necessary as described above. If the controller determines that both printheads have not been removed 108 , the controller may also determine 110 whether one of the printheads has been removed. If one of the printheads has been removed 112 , the pushing force is set 114 to a minimum single printhead value. The carriage can then be monitored 86 during subsequent pushes, and the push force increased 96 if necessary as described above. If none of the printheads have been removed 116 , the controller may continue to monitor 86 the carriage position during subsequent pushes. Although the embodiment of FIG. 4 uses the example of a carriage 32 which is capable of holding a maximum of two printheads, a similar process could be used for a carriage with any number of printheads. Instead of setting 106 the pushing force to a minimum empty carriage value, or setting 114 the pushing force to a minimum single printhead value, the controller would reduce the pushing force to an alternate minimum value which corresponded to the number of printheads remaining in the carriage. It should be understood that in other embodiments, it may be preferable to determine if any printheads have been removed from the carriage prior to reducing 84 the pushing force to a minimum value and engaging the service station for the first time.
[0022] This adaptive servicing method allows the minimum force required to service the printheads 50 , 52 , in this case the minimum force required to cap the printheads, to be used. This produces less noise and less part wear than a non-adaptive full-force approach. This minimum force can be referred to as the adaptive servicing force. The adaptive servicing force may be represented by a starting distance from the service station 54 and the level of the motor input 36 provided during the push. The motor input 36 is commonly provided using pulse-width-modulation (PWM).
[0023] [0023]FIG. 5 illustrates another embodiment of actions which adapt a servicing force for a service station. The actions in FIG. 5 make use of the adaptive servicing force determined in the previously discussed process of FIG. 4. The servicing position was determined during the full force push. Based on a knowledge of the dimensions of the service station 54 , and the knowledge of the servicing position, an estimate can be made of the location where the caps 66 , 68 will contact the pens and therefore, where the cap springs 70 start to compress, and the carriage guide rod 28 begins to deflect. An estimate can also be made of the position of the top of the ramp 76 .
[0024] Prior to moving the printhead carriage to the servicing position, the carriage is moved 118 to the starting position for the adaptive servicing force determined during the previous actions. The motor input is set 120 to a first level equal to a first percentage of the motor input which was determined to result in the adaptive servicing force. This first percentage is less than one-hundred percent, and this first motor input level is chosen to be sufficient to move the carriage, engage the activation arm 72 , and start the guide posts 62 moving up the ramp 74 . The motor input is then set 122 to a second level equal to a second percentage of the motor input which was determined to result in the adaptive servicing force. This second percentage is greater than one-hundred percent, and is chosen to be sufficient to overcome the opposing cap spring 70 compression force as well as the opposing force from the carriage guide rod 28 as it is deflected. When the guide posts 62 have reached the top of the ramp 76 , the motor input is set 124 to a third level equal to a third percentage of the motor input which was determined to result in the adaptive capping force. This third percentage is less than one-hundred percent, and is chosen to allow the maintenance sled 60 to reach the servicing position. The first and third percentages may be different or the same.
[0025] The actions of FIGS. 4 and 5 provide several advantages. The actions of FIG. 4 enable the determination of a minimum amount of force, referred to herein as the adaptive servicing force, required to move to the servicing position for a given printer under a given set of circumstances. By determining and using the adaptive servicing force, the amount of noise made while moving the printhead carriage to the servicing position is reduced as compared to servicing with a full force push. The actions of FIG. 5 may be used in combination with those of FIG. 4. By taking a carriage starting position and a fixed motor input required to produce the adaptive servicing force, keeping the starting position, and varying the motor input based on percentages of the fixed input level, the amount of noise made during the movement to the servicing position can be further reduced. In addition to noise reductions, the actions of FIGS. 4 and 5 can also reduce part wear. Furthermore, the noise and part wear reductions are adaptable to each printing mechanism and for a given printing mechanism over time, as parts age and/or get contaminated and as the number of ink cartridges or amount of ink in the cartridges may vary.
[0026] [0026]FIG. 6 illustrates how the embodied actions of FIGS. 4 and 5 might look in terms of a motor input, carriage position, and resultant velocity curves. Full-force velocity curve 126 is illustrated for comparison purposes. The greater the velocity involved during the movement to the servicing position, the greater the noise will be. After completing the actions shown in FIG. 4, the controller will arrive at a fixed motor input as part of its adaptive servicing force. Here, the motor input is expressed in terms of PWM. Fixed motor input curve 128 , starting at a carriage position 130 , allows the carriage to reach a servicing position 132 with a substantially minimum force. The velocity curve associated with fixed motor input curve 128 is adaptive velocity curve 134 . Adaptive velocity curve 134 shows that the velocity while moving to the servicing position 132 is significantly less than the velocity during the full force velocity curve 126 .
[0027] Following the actions of FIG. 5, a fixed level 136 of the fixed motor input curve 128 is used to determine an optimized motor input curve 138 . During a first period 140 , a scaling percentage less than one-hundred percent is applied to the fixed level 136 to come up with the first period 140 of the optimized motor input curve 138 . During a second period 142 , a scaling percentage greater than one-hundred percent is applied to the fixed level 136 to come up with the second period 142 of the optimized motor input curve 138 . During a third period 144 , a scaling percentage less than one-hundred percent is applied to the fixed level 136 to come up with the third period 144 of the optimized motor input curve 138 . Optimized velocity curve 146 corresponds to the optimized motor input curve 138 , and is significantly lower than adaptive velocity curve 134 , thereby significantly reducing noise levels.
[0028] Performing adaptive printhead servicing actions and optimized servicing actions enables a printing mechanism to reliably cap or service printheads with a significantly reduced level of noise. Although capping has been used as an example of one possible servicing technique, the adaptive and optimizing actions described herein can also be applied to other types of printhead servicing, such as scrapping and wiping. The service station 54 , illustrated in the above embodiments, is not meant to be limiting in terms of the type of service station the adaptive printhead servicing actions and optimized servicing actions may be used with. Also, the actuator for the service station which contacts the activation arm 72 need not be a printhead carriage 32 . The printhead carriage 32 should be thought of more broadly as an actuator which is coupled to a motor and which comes into contact with the activation arm 72 . In the case where some other actuator is contacting the activation arm, the actuator would not need to move parallel or in-line with the scanning axis 30 of the printhead carriage. Regardless of the actuator used, the benefit of being able to reliably service the printheads while minimizing noise levels could still be realized and should fall within the scope of this disclosure. In discussing various components of the adaptive printhead servicing actions and optimized servicing actions, various benefits have been noted above.
[0029] It is apparent that a variety of other functionally and/or structurally equivalent modifications and substitutions may be made to perform adaptive printhead servicing actions and optimized servicing actions according to the concepts covered herein depending upon the particular implementation, while still falling within the scope of the claims below.
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A method for reducing a servicing noise is provided. In a measuring action, a servicing position is measured using a full pushing force of an actuator applied to a service station. In a disengaging action, the actuator is disengaged from the service station. In a reducing action, the pushing force is reduced to a minimum value. In an engaging action, the service station is engaged with the actuator. In a monitoring action, a position of the actuator is monitored during the engagement. In a comparing action, the actuator position is compared to the stored servicing position. In an increasing action, the pushing force is increased for future engagements if the servicing position has not been reached. A printing mechanism configured to employ such a method is also provided.
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FIELD OF THE INVENTION
[0001] The present invention relates to a process and equipment for fluid catalytic cracking (FCC), for the production of middle distillates of low aromaticity, in the absence of added hydrogen, from heavy hydrocarbon feedstocks of various origins.
[0002] The invention further relates to FCC equipment for the production of the above products.
BACKGROUND OF THE INVENTION
[0003] The purpose of the FCC process is to convert liquid hydrocarbons of high molecular weight, which generally have an Initial Boiling Point (IBP) in the range from 320° to 390°, or higher, and typical densities in the range from 8 to 28° API, such as oil refinery effluents produced from side cuts from vacuum towers, called heavy vacuum gas oil (HVGO), or from the bottom of atmospheric towers, called atmospheric residue (ATR), or mixtures of these effluents, to light hydrocarbon fractions such as gasoline (IBP around 30° C.) and liquefied petroleum gas (LPG) (maximum vapour pressure of 15 kgf/cm 2 at 37.8° C.).
[0004] The stages of the FCC process are well known by a person skilled in the art and are described in various patent documents. The process described in Brazilian patent PI 9303773-2 is considered to be particularly important, and is incorporated in its entirety as reference.
[0005] Despite the long existence of the FCC process, there is a constant search for ways of improving the process, by increasing the production of derivatives of greater added value; such as gasoline and LPG. In general, it can be said that the main aim of the FCC processes is maximization of the output of these higher-value derivatives.
[0006] Maximization of said higher-value derivatives is obtained, basically, in two ways. Firstly, by increasing the so-called “conversion”, which corresponds to reduction of the output both of heavy products (clarified oil), and of light cycle oil (LCO). Secondly, by lowering the yields of coke and fuel gas, i.e. by lower “selectivity” of the process with respect to said higher-value derivatives.
[0007] The lower output of fuel gas and coke, on increasing the selectivity of the process for LPG and gasoline, has as additional beneficial consequences, the use of smaller air blowers and wet gas compressors, large machines with high energy consumption, in general limiting the capacity of the FCC units. Moreover, it is economically advantageous to promote increases in products of higher added value.
[0008] An important aspect to consider is the possible benefit or need to increase the production of LPG in accordance with the refiner's needs.
[0009] It is well known by a person skilled in the art that an important aspect of the process is the initial contact of the catalyst with the feed, which has a decisive influence on the conversion and the selectivity of the process by generating high-value products. In the FCC process, the preheated hydrocarbon feed is injected near the bottom of a conversion zone or “riser”, where it comes in contact with the stream of regenerated catalyst, from which it receives a sufficient amount of heat to vaporize it and supply the requirements of the endothermic reactions that predominate in the process.
[0010] After the riser, which is a long vertical pipe having dimensions in industrial units of about 0.5 m to 2.0 m in diameter, with a height of 25-40 m, where chemical reactions take place, the spent catalyst, with coke deposited on its surface and in its pores, is separated from the reaction products and sent to the regenerator for burning the coke to restore its activity and to generate heat which, transferred by the catalyst to the riser, will be utilized by the process.
[0011] The conditions prevailing at the point of introduction of the feed in the riser are decisive for the products that form in the reaction. In this region there is the initial mixing of the feed with the regenerated catalyst, heating of the feed up to the boiling point of its components and vaporization of the major portion of these components. The typical total residence time of the hydrocarbons in the riser is about 1 to 4 seconds.
[0012] For the reactions of catalytic cracking to take place, it is necessary for the vaporization of the feed in the region of mixing with the catalyst to take place rapidly, so that the vaporized hydrocarbon molecules can come in contact with the catalyst particles—whose size is about 70 micrometres—permeating through the mesopores and micropores of the catalyst, and reacting in the acid sites. Failure to achieve this rapid vaporization results in thermal cracking of the liquid fractions of the feed.
[0013] It is known that thermal cracking promotes the formation of by-products such as coke and fuel gas, principally in the cracking of residual feeds. The coke poisons the acid sites and may eventually block the pores of the catalyst. Therefore thermal cracking at the bottom of the riser competes undesirably with catalytic cracking, the purpose of the process.
[0014] Optimization of the conversion of the feed usually requires maximum removal of the coke from the catalyst in the regenerator. Combustion of the coke can take place in conditions of partial combustion or complete combustion.
[0015] In partial combustion, the gases produced by the combustion of the coke are mainly constituted of CO 2 , CO and H 2 O and the content of coke in the regenerated catalyst is of the order of 0.1 to 0.3 wt. %. In complete combustion, carried out in the presence of a greater excess of oxygen, practically all the CO produced in the reaction is converted to CO 2 .
[0016] The reaction of oxidation of CO to CO 2 is highly exothermic, with the result that complete combustion takes place with considerable release of heat, leading to very high regeneration temperatures. However, complete combustion produces catalyst containing less than 0.1 wt. % and, preferably less than 0.05 wt. % of coke, and is, in this respect, more advantageous than partial combustion, making up for a lower catalyst/oil ratio. The explanation for this fact is that complete combustion favours the regeneration of the catalyst and makes it more active, as well as avoiding the use of an expensive boiler for subsequent combustion of the CO.
[0017] The increase in coke in the spent catalyst results in an increase in combustion of coke in the regenerator per unit of mass of circulating catalyst. In conventional FCC units, the heat is removed from the regenerator via the combustion gas and more effectively by the stream of hot regenerated catalyst. An increase in the content of coke on the spent catalyst increases the temperature of the regenerated catalyst and the temperature difference between the regenerator and the reactor.
[0018] Therefore, a reduction in the flow of regenerated catalyst to the reactor, usually called catalyst circulation rate, is necessary in order to meet the thermal demand of the reactor and maintain the same reaction temperature. However, the lower catalyst circulation rate required by the larger temperature difference between the regenerator and the reactor results in reduction of the catalyst/oil ratio, decreasing the conversion, but also decreasing the deposition of coke on the catalyst, in contrast to the initial effect of increase in the content of coke.
[0019] Thus, the circulation of catalyst from the regenerator to the reactor is determined by the thermal demand of the riser and by the temperature that is established in the regenerator, which depends on the production of coke. As the coke produced in the riser is affected by said circulation of catalyst, it is concluded that the process of catalytic cracking functions in conditions of thermal balance, and, for the reasons stated, operation at very high regeneration temperature is undesirable.
[0020] As a rule, with the modern FCC catalysts, the temperatures of the regenerator, and therefore of the regenerated catalyst, are kept below 760° C., preferably below 732° C., as the loss of activity would be very severe above this value. The desirable operating range is from 685° C. to 710° C., The lower value is dictated primarily by the need to ensure proper combustion of the coke.
[0021] With the processing of heavier and heavier feeds, there is a tendency for the production of coke to increase and operation with complete combustion requires the installation of catalyst coolers to keep the temperature of the regenerator within acceptable limits. Generally, the catalyst coolers remove heat from a catalyst stream from the regenerator, returning a substantially cooled catalyst stream to this vessel.
[0022] Various works in the patent literature propose injecting auxiliary streams, such as water or other petroleum fractions, in the risers at a point above the point of injection of the principal feed to be cracked, with the objective of promoting an increase in mixture temperature in the region of feed injection, aiming to increase the percentage of the residual feeds vaporized, without altering the outlet temperature of the riser.
[0023] This approach is described in U.S. Pat. No. 4,818,372, which discloses an apparatus for FCC with temperature control that includes an ascending or descending reactor, device for introducing the hydrocarbon feed under pressure and in contact with a regenerated cracking catalyst, and at east one device for injecting an auxiliary fluid downstream of the reactor zone where the feed and the catalyst come in contact, by which it is claimed that a higher temperature is reached in the region of mixing of the feed with the catalyst. This patent uses an inert external fluid whose main effect is cooling of the region of injection of said fluid, with temperature control and increase in circulation of the catalyst.
[0024] According to the teaching in U.S. Pat. No. 4,818,372, separate injection of an external stream at an upper point of the riser is carried out for the purpose of controlling the temperature profile of the latter, so as to maintain the initial section of the riser at a relatively higher temperature without altering the temperature of the top of the riser (reaction temperature or TRX). This control can also be achieved by recycling heavy naphtha, as taught in U.S. Pat. No. 5,087,349.
[0025] With this same objective, U.S. Pat. No. 5,389,232 teaches recycling of heavy naphtha at upper points of the riser.
[0026] U.S. Pat. No. 4,764,268 suggests injecting a stream of LCO at the top of the riser with the aim of minimizing reactions of overcracking of naphtha.
[0027] A similar alternative, taught in U.S. Pat. No. 5,954,942, aims at an increase in conversion, by “quenching” or rapid cooling with an auxiliary stream of steam in the upper region of the riser.
[0028] Publication WO 93/22400 mentions the possibility of injection, along the riser, of a cracked product, such as LCO, with the aim of cooling the riser and consequently promoting an increase in circulation of catalyst and permitting improvement of the performance of additives based on ZSM-5. Bearing in mind the increase in demand for high-quality middle distillates, to the detriment of the market for gasoline, which is the main product of conventional FCC, changes in the mode of operation of the FCC unit have been discussed with the aim of increasing the output of LCO. Several technical articles discuss changes to the catalytic system and to the process variables, so as to achieve a reduction in the process severity, for the purpose of increasing the yield of middle fractions and reducing the content of aromatics in said fraction. The following are included, among the operating conditions:
reduction of the reaction temperature; reduction of the catalyst/oil ratio; reduction of catalytic activity.
[0032] All these measures aim to reduce the conversion, with consequent increase in the output of decanted oil.
[0033] Some important references on this subject are listed below.
[0000] a) “ Disillate yield from the FCC: process and catalyst changes for maximization of LCO ”, Catalysts Courier, R. W. PETERMAN;
b) Hydrocarbon Publishing Company 2004 , “Advanced Hydrotreating and hydrocarbon technology to produce ultra 2- clean diesel fuel”;
c) “ Studies on maximizing diesel oil production from FCC”, Fifth international symposium on the advances in fluid catalytic cracking , (218 th National meeting, American Chemical Society, 1999);
d) “ New development boosts production of middle distillate from FCC”, Oil and Gas Journal (August, 1970)”.
[0034] LCO is one of the by-products of the FCC, representing from 15% to 25% of the yield and corresponding to the distillation range typically between 220° C. and 340° C. Normally the L′CO has a high concentration of aromatics, even exceeding 80 wt. % of the total hydrocarbons present in said LCO fraction. In some situations it is beneficial to operate the FCC in such a way as to maximize the stream of LCO, and in this case it is desirable to incorporate the LCO in the pool of diesel oil. The high concentration of aromatics in LCO means that it has very poor knock characteristics in diesel engines (low cetane number) and high density. The high aromatics content also makes it difficult to improve its properties by hydrofining or desulphurization.
[0035] In the commonest form of operation for maximizing middle fractions in FCC, the reaction temperature is reduced to extremely low values (from 450° C. to 500° C.), circulation of catalyst is minimized and a catalyst of low activity is used. All these measures increase the yield and improve the quality (lower the aromatics content) of the LCO produced. The problem with this type of operation is that at the same time it promotes an increase in the residual fraction (340° C.+ cut) in FCC, normally used for low-value fuel oil.
[0036] Operation at low temperatures in the post-riser region, which is a consequence of the low reaction temperature, as well as impairing the rectification efficiency of the catalyst, has the result that heavy fractions of the FCC product condense on the surface of the walls and internals of the reactor, leading to formation of coke on the walls of the separating vessel. The phenomenon of coke formation is a characteristic of reactors equipped with rapid separation systems, chiefly in units that process heavy Feeds. The formation of coke from fine films of condensate continues throughout the campaign of the unit, and commonly, at the end there are several tonnes of coke occupying a large proportion of the interior of the separating vessel.
[0037] This coke formation presents a serious risk of ignition and so must be removed completely before starting maintenance work on the unit, causing important losses for the refiner, owing to the delay in the timetable resulting from said removal. There is also the possibility of falling of this coke that has formed inside the separating vessel, during the campaign, which tends to block the flow of the catalyst, often leading to unscheduled shutdown of the unit. In both oases it causes loss of revenue.
[0038] U.S. Pat. No. 6,416,656 teaches a process for simultaneously increasing the yield of diesel and LPG. In this process, the gasoline is recracked to increase the yield of LPG, being injected at a point below the feed nozzle. The process feed is injected at multiple points along the riser, reducing the contact time and hence increasing the yield of LCO. However, the reduced severity of the FCC riser for middle distillates means that the cracking of naphtha in these conditions is not very effective.
[0039] Examination of the references cited shows that the literature neither discloses nor suggests, separately or in combination, the system and process characteristics resulting from the research conducted by the applicant, which led to the elaboration of the present application.
[0040] Advantageously, and differently from the prior art, the use of a dense-bed reactor operating with long catalyst-oil contact time combined with catalysts of low acidity or basic character endows the invention with the possibility of producing a middle distillate of low aromaticity, while operating the industrial unit at conventional FCC temperatures, thus avoiding all the problems arising from operation at low temperatures. Moreover, there is a result of conversion of bottoms similar to the values found in industrial units that operate with high values of process conversion.
[0041] More specifically, the invention relates to a process of catalytic cracking that employs catalytic systems of lower activity than that of the conventional catalytic systems, of reduced acidity or of basic character, that promote reaction mechanisms that modify the composition of the feed, converting it to lighter hydrocarbons, and making it possible to increase the production of saturated hydrocarbons in the cracked products. These catalytic systems are employed in a special reaction system and in appropriate operating conditions, so as to reach levels of conversion similar to those attained in the conventional processes of catalytic cracking and, at the same time, minimize the generation of aromatic hydrocarbons in the products.
[0042] Application of this process makes it possible to obtain a middle distillate of aromaticity below 5 wt. %, of C 10 /C 11 aromatics, and therefore with suitable characteristics for incorporation in the diesel pool, after hydrofinishing or desulplhurization.
[0043] For realization of this objective, a dense-bed FCC reactor is used, which provides long contact times in the risers, in comparison with the conventional FCC process, in which the reactor has entrained-bed fluid dynamics. This guarantees a process conversion level similar to the levels processed in conventional FCC units, which use high-activity catalysts based on zeolite Y.
[0044] However, the big difference is the reduced production of aromatic hydrocarbons in the products, with application of this invention. As a result of combining the suitable catalytic system and the proposed process configuration, there is production of a stream of middle distillates with cetane number about 15 points higher than the typical cetane number of the LCO fractions produced in conventional FCC units and having a boiling point range similar to that of diesel. Moreover, the process produces a gasoline that can be used as petrochemical naphtha, after desulphurization.
[0045] The present invention offers solutions to a number of problems arising from the operation of FCC at low severity, as it operates with reaction temperatures similar to those employed in conventional FCC processes. In accordance with the concept of the invention, conditions of low severity mean a reaction temperature in the range from 460° C. to 520° C. In the case of heavy feeds, this range of reaction temperature results in a marked loss of rectification efficiency, with significant effects on the entrainment of hydrocarbons to the regenerator, and therefore on the heating of the latter. To this effect is associated the low thermal demand of the riser, resulting at a catalyst/oil ratio in the range from 3.0 to 6.0, increasing the output of decanted oil, along with cumulative increase in the temperature of the regenerator.
[0046] In the present invention, the reactor operates at temperatures normally employed in FCC units, increasing the process severity on the basis of the contact time and the catalyst/oil ratio. On combining this process conception with catalysts of low activity with reduced acidity or with basic character, it is possible to operate with high conversions and products with low aromaticity.
[0047] The stage of rectification of the spent catalyst, for removal of the residual hydrocarbons, has an efficiency similar to that achieved in conventional FCC units, since there is no need to operate the unit with moderate temperatures to reduce the severity.
[0048] Accordingly, the technique envisages a process for catalytic cracking of heavy feeds, in the absence of added hydrogen, using a dense-bed reactor, that operates with high catalyst/oil ratio and long contact times, producing a middle distillate of low aromaticity and low yield of decanted oil.
[0049] Said process employs catalysts that promote cracking reactions, while partially inhibiting the formation of aromatic molecules in the lighter products resulting from the reaction.
[0050] A patent published recently: WO 2007/082629, also for the purpose of maximization of LCO and reduction of aromatics in the products generated in the FCC process, describes the use of catalysts which, on the basis of their characteristics, could be applied in the present invention. However, in said published patent, the process preferably takes place in two stages, where the first stage employs mild operating conditions of low severity and the second uses conventional zeolitic FCC catalyst. Accordingly, to achieve high conversion in the process it is necessary to install two FCC units with conventional hardware, i.e. with cracking reactions in risers.
[0051] In contrast to the aforementioned publication, the present invention provides a process that performs the entire conversion in a single stage, based on the use of a dense-bed reactor. Furthermore, the operating conditions adopted are considered to be of high severity in comparison with the processes that maximize middle distillates, as the proposed invention employs high catalyst/oil ratios and extremely long contact times. Accordingly, the present invention proposes an alternative that is economically more attractive and gives excellent results in terms of yield and quality, according to the example given in the document. To summarize, the proposed invention envisages the use of only one catalytic system of low activity in a process with only one stage operating with an extended contact time, a combination not foreseen in the literature.
[0052] The overall result of the process according to the present invention is an increase in the yield of middle distillates of low aromaticity and petrochemical naphtha, said process and equipment used for carrying out said process being described and claimed in the present application.
SUMMARY OF THE INVENTION
[0053] The present invention relates to an FCC process for the production of middle distillates of low aromaticity that comprises the following stages:
a) submitting a feed consisting of heavy fractions of hydrocarbons, such as a heavy vacuum gas oil, or an atmospheric residue, or a mixture thereof in any proportions, to a reaction of fluid catalytic cracking, in the absence of added hydrogen, in the riser of a dense-bed FCC reactor, operated:
(i) at temperatures that vary in the range from 520° C. to 560° C., preferably around 540° C. (ii) using a cracking catalyst of low activity, of reduced acidity or of basic character; (iii) at a catalyst/oil ratio in the range from 8 to 15, preferably 10, and (iv) with a contact time in the range from 30 to 120 seconds, preferably in the range from 70 to 90 seconds;
b) withdrawing the effluent obtained in the above reaction at the top of the dense-bed catalytic cracking reactor, submitting it to fractionation in a fractionating tower that produces a gas fraction that is sent to a gas recuperation section, plus a light naphtha fraction and a middle distillate, both of low aromaticity, and sending these for subsequent treatment and sale.
[0060] The invention also relates to equipment that comprises a riser ending in a dense-bed FCC reactor where a reaction of fluid catalytic cracking is carried out, in the absence of added hydrogen, producing the effluent which, after it has been fractionated in a fractionating tower, generates the middle distillate of low aromaticity which, after it has been desulphurized, can be incorporated in the diesel pool and the naphtha fraction, also of low aromaticity which, after being separated in a stabilizers tower, and desulphurized, can be sold as petrochemical naphtha.
[0061] Additionally, the naphtha fraction can be sent to the conventional FCC unit where it undergoes recracking to produce a high-octane gasoline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] The FCC process and equipment for production of middle distillates of low aromaticity and high-octane gasoline, according to the present invention, will now be described in detail, based on the diagrams referred to below, which are an integral part of the present specification.
[0063] FIG. 1 shows a simplified schematic representation of equipment to be used for carrying out the process of the present invention.
[0064] FIG. 2 shows a graph with comparative data for conversion between a conventional FCC process and the process of the present invention.
[0065] FIG. 3 shows a graph with comparative data for the results obtained for aromatics content in the fraction of middle distillates between the conventional FCC process and the process of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0066] For better understanding, the FCC process for production of middle distillates of low aromaticity, according to the present invention, will be described in detail referring to the diagrams, according, to the identification of the respective components.
[0067] FIG. 1 shows a simplified schematic representation of the present invention, comprising a dense-bed FCC unit into which a feed A is injected at the bottom of the riser ( 1 ), consisting of fractions of the HVGO or ATR type, or a mixture of the two in any proportions, at a controlled injection temperature in the range from 150° C. to 300° C. The reaction temperature is controlled in the range from 520° C. to 560° C., and is preferably maintained around 540° C. The mixture of hydrocarbons and catalyst travels through the riser ( 1 ) and is discharged into the dense-bed FCC reactor ( 2 ), where the cracking reactions continue in the dense bed. The catalyst/oil ratio in the reactor varies in the range from 8 to 15, preferably 10, and the contact time between the catalyst and the hydrocarbons in the assembly of riser ( 1 ) and dense-bed FCC reactor ( 2 ) can vary between 30 and 120 seconds, but should preferably be maintained in the range from 70 to 90 seconds.
[0068] From the vessel of the dense-bed FCC reactor ( 2 ), the catalyst flows directly to the rectifier ( 3 ) in the annular region of the lower portion of the vessel and from there, following steam rectification, the catalyst is sent to the regenerator, through a pipe ( 4 ). The level of the catalyst bed in reactor ( 2 ) is controlled by a valve ( 5 ). The catalyst from the regenerator is recycled to the riser ( 1 ) via a pipe ( 7 ), the flow of catalyst in pipe ( 7 ) being controlled by a valve ( 8 ).
[0069] In these conditions the dense-bed FCC reactor ( 2 ) produces an effluent B, which, after fractionation in the fractionating tower ( 9 ), generates a gas fraction C, which is sent to the gas recuperation section, a light naphtha D which, after it has been desulphurized, can be sold as petrochemical naphtha, a middle distillate of low aromaticity E which, after desulphurization, can be incorporated in the diesel pool, and a bottom product F, normally intended for fuel oil.
[0070] The temperature of the catalyst in the rectifier ( 3 ) is around 540° C., which is typical of conventional operations, allowing rectification of high efficiency and eliminating the drawbacks of rectification at low severity.
[0071] The temperature of the bed in the regenerator ( 6 ) is preferably adjusted to a temperature range from 685° C. to 710° C., by appropriate control of the temperature of the feed for the dense-bed reactor in the range from 150° C. to 300° C.
[0072] The invention also includes another aspect that relates to the use of a low-activity cracking catalyst of reduced acidity, or of basic character, that minimizes the production of aromatics in comparison with conventional FCC catalysts. The low catalytic activity of the catalyst is characterized in that it provides conversions of typical FCC feeds of, at most, 40% also in operating conditions typical of FCC, at a catalyst/oil ratio of about 10, reaction temperature of 540° C. and contact time between feed and catalyst of less than 10 seconds. The catalyst recommended in the present invention must have a low concentration or preferably be free from acidic zeolites in the protic form or exchanged with rare earths, usually employed as the main active ingredient of conventional FCC catalysts. The catalytic composition suitable for the invention can include the other components of the matrix of an FCC catalyst such as oxides and hydroxides of aluminium and/or silicon, as well as clays to impart suitable physical properties to the catalyst, whose acidity and activity can be adjusted by lixiviation and/or doping with alkali metals, alkaline earths, trivalent metals or transition metals. Optionally, other materials with basic characteristics or of low protic acidity such as hydroxides and oxides of transition metals, mixed derivatives of hydroxides and oxides, cationic and anionic clays, phosphates, hydroxy-phosphates and silica-alumina phosphates, doped or treated thermally and/or chemically, can also constitute or be incorporated in the catalytic composition required for the invention, it being, however, important to avoid the presence of components that promote dehydrogenating activity. The catalyst of the present invention as defined promotes the formation of saturated hydrocarbons to the detriment of aromatics, as its low activity is compensated by a longer contact time between the catalyst and feed during the cracking reaction without significantly promoting an increase in the aromatics content of the products.
[0073] The present invention will now be illustrated with an example, which should not, however, be regarded as limiting it, but only has the aim of demonstrating that the objectives of the invention were achieved in full.
EXAMPLE
[0074] A conventional zeolitic catalyst designated “A” and another non-zeolitic catalyst of low activity designated “B”, as recommended in the present invention, underwent comparative tests using gas oil feed typical of Brazilian petroleum (Table 1) in a fluidized-bed unit, a stirred reactor of the CREC type (of LASA, H. I. (1992)—U.S. Pat. No. 5,102,628), suitable for kinetic studies and that permits, by its design characteristics, operation with extended residence times. The catalyst is charged in the reaction chamber and kept fluidized with ascending motion by an impeller rotating at high speed. When the reactor is in the desired reaction conditions the feed is injected and the required reaction time is reached, after which the products are discharged and analysed by gas chromatography. A constant catalyst/feed ratio of about 10 was used in the experiments presented here. A conventional FCC catalyst “A”, suggested by the manufacturer for operation to maximize middle fractions (LCO) in the FCC process, was tested at a temperature of 480° C. recommended for this application, being lower than the temperature employed in normal operation of greater severity for maximization of gasoline. This is the reference case.
[0075] The case that is intended to illustrate the scope of the present invention used catalyst “B”, a mixed aluminium-magnesium oxide with basic characteristics and relatively low cracking activity, at the reaction temperature typical of conventional FCC, 540° C.
[0076] As can be seen from FIG. 2 , on applying the sufficient residence time, the system recommended in the present invention is able to reach levels of conversion similar to those of the reference case, as well as similar yields of middle tractions. However, as shown in FIG. 3 , for the same conversion or the same yield of bottoms/residue, the resultant aromatics content in the middle fractions (C 10 -C 11 ) is significantly lower in the case of the system recommended for the present invention, thus demonstrating the clear advantage of the process of the invention.
[0000]
TABLE 1
MARLIN - REPLAN PETROLEUM
RESULTS
Density at 20/4° C.
0.9519
° API
16.5
Viscosity at 60° C. (ASTM D 455); cSt.
107
Viscosity at 82.2° C. (ASTM D 455), cSt.
35.06
Viscosity at 100° C. (ASTM D 455), cSt.
17.72
Refractive index at 70° C. (ASTM D 1774)
1.5135
Sulphur (ASTM D 5354), ppm
7116
Distillation (ASTM D 97) ° C.
IBP
291.1
5%
355.8
10%
381.4
30%
430.5
50%
460.6
70%
493.7
90%
535.3
95%
555.8
FBP
621.1
Ramsbottom Carbon Residue (ASTM D 524), wt. %
1.23
Aniline point (ASTM D 611) ° C.
72.5
Total Nitrogen (Antek), ppm
3246
Basic Nitrogen (UOP 269), ppm
1307
HPLC/SFC, wt. %
Saturated compounds
51.1
Monoaromatics
18.3
Diaromatics
18.9
Triaromatics
8.1
Polyaromatics
3.6
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The present invention relates to a process and equipment for fluid catalytic cracking for the production of middle distillates of low aromaticity that comprises cracking a mixed feed consisting of heavy fractions of hydrocarbons, in the absence of added hydrogen and employing a catalyst of low activity and low acidity, in a dense-bed FCC reactor to produce an effluent constituted of fractions of middle distillates and naphtha of low aromaticity.
| 2
|
CROSS REFERENCE
[0001] This application is a continuation of application Ser. No. 10/104,179, filed on Mar. 20, 2002 (which is incorporated herein by reference).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to compositions such as those used for coating implantable medical devices such as stents.
[0004] 2. Description of Related Art
[0005] Percutaneous transluminal coronary angioplasty (PTCA) is a procedure for treating heart disease. A catheter assembly having a balloon portion is introduced percutaneously into the cardiovascular system of a patient via the brachial or femoral artery. The catheter assembly is advanced through the coronary vasculature until the balloon portion is positioned across the occlusive lesion. Once in position across the lesion, the balloon is inflated to a predetermined size to radially compress against the atherosclerotic plaque of the lesion to remodel the vessel wall. The balloon is then deflated to a smaller profile to allow the catheter to be withdrawn from the patient's vasculature.
[0006] A problem associated with the above procedure includes formation of intimal flaps or torn arterial linings which can collapse and occlude the conduit after the balloon is deflated. Moreover, thrombosis may develop shortly after the procedure and restenosis of the artery may develop over several months after the procedure, which may require another angioplasty procedure or a surgical by-pass operation. To reduce the partial or total occlusion of the artery by the collapse of arterial lining and to reduce the chance of the development of thrombosis and restenosis, a stent is implanted in the lumen to maintain the vascular patency.
[0007] Stents are used not only as a mechanical intervention but also as a vehicle for providing biological therapy. As a mechanical intervention, stents act as scaffoldings, functioning to physically hold open and, if desired, to expand the wall of the passageway. Typically, stents are capable of being compressed, so that they can be inserted through small lumens via catheters, and then expanded to a larger diameter once they are at the desired location. Biological therapy for reducing or eliminating thrombosis or restenosis can be achieved by medicating the stents. Medicated stents provide for the local administration of a therapeutic substance at the diseased site. In order to provide an efficacious concentration to the treated site, systemic administration of such medication often produces adverse or toxic side effects for the patient. Local delivery is a preferred method of treatment in that smaller total levels of medication are administered in comparison to systemic dosages, but are concentrated at a specific site. Local delivery thus produces fewer side effects and achieves more favorable results.
[0008] Local delivery can be accomplished by coating the stent with a polymeric carrier containing a biologically active agent. A polymer dissolved in an organic solvent and the agent added thereto are applied to the stent and the organic solvent is allowed to evaporate, leaving a polymeric coating impregnated with the agent.
[0009] Biologically active agents including polysaccharides, e.g., heparin, and polycationic peptides, e.g., poly-L-arginine have proven to provide beneficial effects in the treatment of thrombosis and restenosis, more particularly when used in conjunction with a stent. However, incorporation of these compounds into a polymeric carrier has proven to be challenging due to such compounds' limited solubility. To pose the problem more concretely by way of example, heparin is soluble in water but not in organic solvents, while conventional polymers used for the sustained release of heparin are soluble in organic solvents but not water. To avoid the problem of solubility incompatibility, efforts have been made to fabricate heparin-polymer coatings from heparin-polymer suspensions. For example, U.S. Pat. Nos. 5,837,313 and 5,879,697, disclose micronizing heparin followed by physically blending with a polymer and solvent to form the suspension. The suspension methods have drawbacks and disadvantages. The manufacturing process, for example, requires spraying equipment capable of handling particles. In addition, heparin-polymer suspensions lack sufficient stability in the absence of suspension agents and require constant agitation during the coating process.
[0010] Alternatively, a complex of heparin with a cationic surfactant can be formed for converting the heparin into an organically soluble compound. Examples of suitable surfactant counter ions include benzalkonium and tridodecylmethyl ammonium. However, a surfactant-bound heparin has lower antithrombotic activity because the surfactant alters heparin's charge balance and binding coefficient with coagulation cofactors.
[0011] In view of the foregoing, there is a need to prepare a true solution of polysaccharides and cationic peptides with organic solvent compositions commonly used to form polymeric coatings on implantable medical devices.
SUMMARY
[0012] In accordance with one embodiment of the invention, a therapeutic composition comprising a polysaccharide or a cationic peptide dissolved in an organic substance is provided. The polysaccharide can be heparin, heparin salts, heparinoids, heparin-based compounds, heparin having a hydrophobic counter-ion, dermatan sulfate, keratan sulfate, chondroitin sulfate, hyaluronic acid and hyaluronates. The cationic peptide can be L-arginine, oligo-L-arginine, poly-L-arginine, or arginine-containing peptide. The organic substance can be formamide.
[0013] In accordance with another embodiment of the invention, a method of coating an implantable medical device, for example a stent, is provided, comprising applying the above mentioned composition to the device and allowing the organic substance to evaporate.
[0014] In accordance with another embodiment, a method of coating a stent is provided. The method includes the acts of preparing a solution comprising heparin or a heparin derivative in an organic substance; applying the solution to the stent; and allowing the organic substance to evaporate. The organic substance can be formamide. In one embodiment, the method additionally includes combining the solution with a composition including a polymer and optionally a biologically active substance. The polymer can be, for example, poly(ethylene-co-vinyl alcohol), polyacrylates, poly (ethylene glycol), polyurethanes, polyesters, fluorinated polymers, and mixtures or combinations thereof. The biologically active substance can be, for example, actinomycin D, rapamycin, taxol, estradiol, poly(ethylene glycol)/poly(ethylene oxide), and derivatives thereof.
[0015] In accordance with another embodiment, a method for coating a stent is provided, comprising preparing a solution comprising L-arginine, or polymers or oligomers thereof, in an organic substance; applying the solution to the stent, and allowing the organic substance to evaporate. The organic substance can be formamide. In one embodiment, the method additionally comprises combining the solution with a composition including a polymer and optionally a biologically active substance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 schematically depicts a cross-section of a coating on a stent in accordance with one embodiment of the present invention.
[0017] FIG. 2 is a scanning electronic micrograph (SEM) showing a coated stent, where the stent coating included heparin applied in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates a partial cross section of a substrate 1 of an implantable medical device, such as a stent, having a coating. The coating can include, for example, an optional primer layer 2 , a reservoir layer 3 , and an optional topcoat layer 4 . According to one embodiment of the present invention, the reservoir layer 3 can comprise a polymer and a polysaccharide. One example of a biologically active polysaccharide is heparin or a heparin derivative. Heparin is known to have an antithrombotic property, among other biologically active functions, and can be made from a mixture of sulfated polysaccharide chains based on D-glucosamine and D-glucoronic or L-iduronic acid.
[0019] “Heparin derivative” or “derivative of heparin” is intended to include any functional or structural variation of heparin. Representative variations include alkali metal or alkaline-earth metal salts of heparin, such as sodium heparin (also known as hepsal or pularin), potassium heparin (formerly known as clarin), lithium heparin, calcium heparin (also known as calciparine), magnesium heparin (also known as cutheparine), and low molecular weight heparin (also known as ardeparin sodium). Other examples include heparan sulfate, heparinoids, heparin-based compounds and heparin having a hydrophobic counter-ion.
[0020] Examples of other polysaccharides include glycosaminoglycans (or mucopolysaccharides) such as keratan sulfate, chondroitin sulfate, dermatan sulfate (also known as β-heparin or as chondroitin sulfate B), hyaluronic acid and hyaluronates.
[0021] According to another aspect of the present invention, the reservoir layer 3 can comprise highly positively charged peptides or proteins, such as L-arginine or oligomers and polymers of L-arginine. These oligomers and polymers are oligo- or polycationic peptides (or proteins) and are products of self-polycondensation of an amino acid L-arginine, also known as 2-amino-5-guanidinovaleric acid having a formula
NH═C(NH 2 )—NH—CH 2 —CH 2 —CH(NH 2 )COOH.
[0022] One example of oligomeric L-arginine that can be used is a heptamer known as R7. Oligomers and polymers of L-arginine can be used in a form of a derivative, such as a salt, for example, hydrochloride, trifluoroacetate, acetate, or sulfate salts. Oligomers and polymers of L-arginine, including R7, for the purposes of the present invention are collectively designated as PArg. A general formula of PArg as a hydrochloride salt can be represented as H[—NH—CHR—CO—] m OH.HCl, or PArg.HCl, where “m” can be an integer within a range of between 5 and 1,000 and “R” is 1-guanidinopropyl radical having the structure —CH 2 —CH 2 —CH 2 —NH—C(NH 2 )═NH. In case of R7, m equals 7. “L-arginine,” “oligomers and polymers of L-arginine,” or “PArg” is intended to include pure L-arginine in its monomeric, oligomeric or polymeric form as well as derivatives of L-arginine.
[0023] Formamide (H—CO—NH 2 ) can be used as a solubilizing agent for heparin, heparin derivatives, or PArg. Heparin or a heparin derivative or PArg can be dissolved in formamide. At least 8% by mass of a solution of heparin or a derivative thereof or PArg in formamide can be prepared.
[0024] A heparin-formamide solution or a PArg-formamide solution can be mixed with a polymer. Should the polymer not be capable of dissolving in formamide, the polymer can be first admixed with an organic solvent or a mixture of organic solvents capable of dissolving the polymer. The solution can be applied onto the surface of the stent or onto the primer layer 2 by spraying or dipping techniques as is well known to one of ordinary skilled in the art. Alternatively, the heparin-formamide solution or the PArg-formamide solution can be applied followed by applying the solution of the polymer in the organic solvent or the mixture of organic solvents. The process can be repeated to obtain a suitable weight of the compound on the stent.
[0025] FIG. 2 is a SEM of a stent coating which includes heparin applied according to one embodiment of the present invention. The coating shown on FIG. 2 was comprised of:
[0026] (a) a reservoir 3 having about 740 μg of total solids which included poly(ethylene-co-vinyl alcohol) (EVAL) and heparin in a 2:1 mass ratio; and
[0027] (b) a topcoat layer (about 54 μg of EVAL).
[0028] As evidenced by the micrograph, a very smooth coating was obtained.
[0029] The above-mentioned poly(ethylene-co-vinyl alcohol) (EVAL) is one example of a suitable polymer than can be employed to prepare the drug-polymer layer 3 , the optional primer layer 2 and/or the optional topcoat layer 4 . EVAL has the general formula —[CH 2 —CH 2 ] m —[CH 2 —H(OH)] n —. EVAL is a product of hydrolysis of ethylene-vinyl acetate copolymers. EVAL can also be a terpolymer including up to, for example, 5 molar % of units derived from styrene, propylene and other suitable unsaturated monomers. Other suitable polymers that can be used include poly(hydroxyvalerate), poly(L-lactic acid), polycaprolactone, poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polydioxanone, polyorthoester, polyanhydride, poly(glycolic acid), poly(D,L-lactic acid), poly(glycolic acid-co-trimethylene carbonate), polyphosphoester, polyphosphoester urethane; poly(amino acids), cyanoacrylates, poly(trimethylene carbonate), poly(iminocarbonate), co-poly(ether-esters) (e.g. PEO/PLA), polyalkylene oxalates, polyphosphazenes, biomolecules (such as fibrin, fibrinogen, cellulose, starch, collagen and hyaluronic acid), polyurethanes, silicones, polyesters, polyolefins, polyisobutylene and ethylene-alphaolefin copolymers, acrylic polymers and copolymers, such as poly(alkyl)(meth) acrylates, for example, poly(butyl methacrylate) and copolymers of butyl methacrylate, for instance, with hydroxymethyl methacrylate; vinyl halide polymers and copolymers (such as polyvinyl chloride), polyvinyl ethers (such as polyvinyl methyl ether), polyvinylidene halides (such as polyvinylidene fluoride and polyvinylidene chloride), polyacrylonitrile, polyvinyl ketones, polyvinyl aromatics (such as polystyrene), polyvinyl esters (such as polyvinyl acetate), copolymers of vinyl monomers with each other and olefins (such as ethylene-methyl methacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetate copolymers), polyamides (such as Nylon 66 and polycaprolactam), alkyd resins, polycarbonates, polyoxymethylenes, polyimides, polyethers, epoxy resins, polyurethanes, rayon, rayon-triacetate, cellulose and its derivatives, cellulose acetate, cellulose butyrate, cellulose acetate butyrate, cellophane, cellulose nitrate, cellulose propionate, cellulose ethers, soluble fluorinated polymers and carboxymethyl cellulose.
[0030] The topcoat layer 4 may also contain a small amount of Na-heparin and/or PArg. The reservoir layer 3 can optionally include a therapeutic agent with or without heparin or PArg. If such an agent is to be used, the agent can be either incorporated into the heparin or PArg composition, the polymer composition, or added subsequent to the combination of these compositions. Examples such of suitable therapeutic agents include actinomycin D or derivatives and analogs thereof. Synonyms of actinomycin D include dactinomycin, actinomycin IV, actinomycin I 1 , actinomycin X 1 , and actinomycin C 1 . The active agent can also fall under the genus of antineoplastic, anti-inflammatory, antiplatelet, anticoagulant, antifibrin, antithrombin, antimitotic, antibiotic, anfiallergic and antioxidant substances. Examples of such antineoplastics and/or antimitotics include paclitaxel (e.g. Taxol® by Bristol-Myers Squibb Co. of Stamford, Conn.), docetaxel (e.g. Taxotere®, from Aventis S. A. of Frankfurt, Germany) methotrexate, azathioprine, vincristine, vinblastine, fluorouracil, doxorubicin hydrochloride (e.g. Adriamycin® from Pharmacia & Upjohn, of Peapack N.J.), and mitomycin (e.g. Mutamycin® from Bristol-Myers Squibb Co. of Stamford). Examples of such antiplatelets, anticoagulants, antifibrin, and antithrombins include hirudin, argatroban, forskolin, vapiprost, prostacyclin and prostacyclin analogues, dextran, D-phe-pro-arg-chloromethylketone (synthetic antithrombin), dipyridamole, glycoprotein IIb/IIIa platelet membrane receptor antagonist antibody, recombinant hirudin, and thrombin inhibitors such as Angiomax® made by Biogen, Inc., of Cambridge, Mass.). Examples of such cytostatic or antiproliferative agents include angiopeptin, angiotensin converting enzyme inhibitors such as captopril (e.g. Capoten® and Capozide® from Bristol-Myers Squibb Co. of Stamford), cilazapril or lisinopril (e.g. Prinivil® and Prinzide® from Merck & Co., Inc. of Whitehouse Station, N.J.); calcium channel blockers (such as nifedipine), colchicine, fibroblast growth factor (FGF) antagonists, fish oil (omega 3-fatty acid), histamine antagonists, lovastatin (an inhibitor of HMG-CoA reductase, a cholesterol lowering drug, brand name Mevacor® from Merck & Co., Inc., of Whitehouse Station, N.J.), monoclonal antibodies (such as those specific for Platelet-Derived Growth Factor (PDGF) receptors), nitroprusside, phosphodiesterase inhibitors, prostaglandin inhibitors, suramin, serotonin blockers, steroids, thioprotease inhibitors, triazolopyrimidine (a PDGF antagonist), and nitric oxide. An example of an antiallergic agent is permirolast potassium. Other therapeutic substances or agents which may be appropriate include alpha-interferon, genetically engineered epithelial cells, rapamycin and its derivatives, estradiol and its derivatives, poly(ethylene glycol)/poly(ethylene oxide) and dexamethasone.
[0031] The embodiments of the present invention are described with reference to a stent, such as a self-expandable or a balloon expandable stent. Other suitable implantable medical device can also be similarly coated. Examples of such implantable devices include, but are not limited to, stent-grafts, grafts (e.g., aortic grafts), artificial heart valves, cerebrospinal fluid shunts, pacemaker electrodes, and endocardial leads (e.g., FINELINE and ENDOTAK, available from Guidant Corp.). The underlying structure of the device can be of virtually any design. The device can be made of a metallic material or an alloy such as, but not limited to, cobalt chromium alloy (ELGILOY), stainless steel (316L), “MP35N,” “MP20N,” ELASTINITE (Nitinol), tantalum, nickel-titanium alloy, platinum-iridium alloy, gold, magnesium, or combinations thereof. “MP35N” and “MP20N” are trade names for alloys of cobalt, nickel, chromium and molybdenum available from Standard Press Steel Co. of Jenkintown, Pa. “MP35N” consists of 35% cobalt, 35% nickel, 20% chromium, and 10% molybdenum. “MP20N” consists of 50% cobalt, 20% nickel, 20% chromium, and 10% molybdenum. Devices made from bioabsorbable or biostable polymers could also be used with the embodiments of the present invention.
[0032] Embodiments of the present invention are further illustrated by the following examples:
EXAMPLE 1
[0033] About 1 milliliter (1.133 gram) of formamide was added to 0.1 gram of sodium heparin (NaHep) obtained from Aldrich Chemical Co. of Milwaukee, Wis. The suspension was heated at a temperature about 70° C. After about 5 minutes of heating, sodium heparin was fully dissolved in formamide to form about 8.1 mass % NaHep solution. About 0.15 gram of EVAL was dissolved in about 0.85 gram of dimethylacetamide (DMAC) to form 15% (mass) solution of EVAL. About 1 gram of the 15% EVAL solution was further dissolved in a mixture of about 2 grams of DMAC and about 1 gram of methyl alcohol. This final EVAL solution was added to the NaHep-formamide solution prepared above. The two solutions were thoroughly mixed to form a clear heparin-polymer (NaHep-EVAL) solution. The NaHep-EVAL solution had a solid content of about 4.8 mass % and the mass ratio of NaHep to EVAL of about 2:3.
[0034] At room temperature, the NaHep-EVAL solution was not sufficiently stable and developed substantial turbidity within about 15 minutes after the mixing of the NaHep-formamide solution and the EVAL solution. In order to avoid the phase separation, the NaHep-EVAL solution was heated at about 70° C. for several minutes until the solution had become clear again. When kept at a temperature of about 40° C, the NaHep-EVAL solution was clear and stable.
[0035] Prior to application, the NaHep-EVAL solution was filtered through 0.45 micron filter. The NaHep-EVAL solution was then applied to a stent using a spray apparatus, such as an EFD 780S spray nozzle with a VALVEMATE 7040 control system, manufactured by EFD, Inc. of East Providence, R.I. The EFD 780S spray nozzle is an air-assisted external mixing atomizer. The composition was atomized by air and applied to the stent surfaces at a pressure of about 103.4 kPa (15 psi or 1.03 atm). The distance between the spray nozzle and the stent surface was about 105 mm. The NaHep-EVAL solution was fed to the spray block at a pressure of about 23.3 kPa (3.35 psi or 0.23 atm).
[0036] The container with NaHep-EVAL solution was maintained at a temperature of about 40° C., in order to avoid possible precipitation of the polymer or the drug. The spray block temperature was kept at about 60° C. During the process of applying the composition, the stent can be optionally rotated about its longitudinal axis, at a speed of 50 to about 150 rpm. The stent can also be linearly moved along the same axis during the application.
[0037] The NaHep-EVAL solution was applied to a 18-mm TETRA stent (available from Guidant Corp.) in a series of 10-second passes, to deposit about 45 μg of coating per spray pass. Between the spray passes, the stent was dried for 10 seconds using flowing air with a temperature of about 80° C. to 100° C. A total of about 1.2 milligram of solid mass was applied. The coated stent was partially dried overnight at room temperature. Upon visual inspection, no pool webs were observed.
EXAMPLE 2
[0038] About 1 milliliter (1.133 gram) of formamide was added to about 0.1 gram of poly-L-arginine sulfate. The suspension was heated at a temperature of 50° C. After a few minutes of heating, PArg was fully dissolved in formamide to form about 8.1 mass % PArg solution. About 0.15 gram of EVAL was dissolved in about 0.85 gram of DMAC to form 15% (mass) solution of EVAL. About 1 gram of the 15% EVAL solution was further dissolved in a mixture of about 2 grams of DMAC and about 1 gram of methyl alcohol. This final EVAL solution was added to the PArg-formamide solution. The two solutions were thoroughly mixed to form the PArg-EVAL solution. The PArg-EVAL solution had a solid content of about 4.8 mass % and the mass ratio of PArg to EVAL of about 2:3.
[0039] At room temperature, the PArg-EVAL solution was not sufficiently stable and developed substantial turbidity within about 15 minutes after the mixing of the PArg-formamide solution with the EVAL solution. In order to avoid phase separation, the PArg-EVAL solution was heated at about 70° C. for several minutes until the solution became clear again. When kept at a temperature of about 40° C., the PArg-EVAL solution was clear and stable.
[0040] Using the process and equipment described in Example 1, the PArg-EVAL solution was applied to an 8-mm TETRA stent. 10 μg of coating per spray pass was applied. Between the spray passes, the stent was dried for 10 seconds using flowing air with a temperature of about 80° C. to 100° C. A total of about 500 milligram of solid mass was applied. Upon visual inspection, no pool webs were observed.
EXAMPLE 3
[0041] A drug-polymer layer containing NaHep-EVAL was formed on a stent according to the procedure described in Example 1. A 2% (mass) solution of EVAL in DMAC was prepared by mixing about 2 grams of EVAL and about 98 grams of DMAC. Using the process and equipment described in Example 1, the 2% EVAL solution was applied to an 8-mm TETRA stent coated with the NaHep-EVAL drug-polymer layer to form a topcoat layer. About 10 μg of coating per spray pass was deposited. A total of about 33 μg of solid mass was applied as a topcoat layer followed by drying in a convection oven at about 70° C. for about 2 hours.
[0042] Using the process and equipment described in Example 1, the 2% EVAL solution was also applied to an 18-mm TETRA stent coated with the NaHep-EVAL drug-polymer. layer to form a topcoat layer. About 20 μg of coating per spray pass was deposited. A total of about 120 μg of solid mass was applied as a topcoat layer followed by drying in a convection oven at about 70° C. for about 2 hours.
EXAMPLE 4
[0043] A drug-polymer layer containing PArg-EVAL was formed on a stent according to the procedure described in Example 1. A 2% (mass) solution of EVAL in DMAC was prepared by mixing about 2 grams of EVAL and about 98 grams of DMAC. Using the process and equipment described in Example 1, the 2% EVAL solution was applied on an 8-mm TETRA stent coated with the PArg-EVAL drug-polymer layer to form a topcoat layer. About 10 μg of coating per spray pass was deposited. A total of about 40 μg of solid mass was applied as a topcoat layer followed by drying in a convection oven at about 70° C. for about 2 hours.
[0044] Using the process and equipment described in Example 1, the 2% EVAL solution was also applied to an 18-mm TETRA stent coated with the PArg-EVAL drug-polymer layer to form a topcoat layer. About 20 μg of coating per spray pass was deposited. A total of about 400 μg of solid mass was applied as a topcoat followed by drying in a convection oven at about 70° C. for about 2 hours.
[0045] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications can be made without departing from this invention in its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.
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A therapeutic composition is provided including a polysaccharide or a cationic peptide dissolved in an organic substance. The polysaccharide can be heparin or a derivative of heparin. The cationic peptide can be L-arginine, oligo-L-arginine or poly-L-arginine. The organic substance can be formamide. A method of coating an implantable medical device is also provided, comprising applying the therapeutic composition to the device and allowing the organic substance to evaporate. The device can be a stent.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] A cover for a slide-out unit found on recreational vehicles, mobile homes, and the like, includes a canopy and scissors-type support arms which extend as the slide-out unit is extended from the main body of the vehicle. The scissors arms are mounted at a bias so that a support bar across the underside of the canopy is raised as the awning cover is extended and lowered as the awning cover is retracted with the slide-out unit. One edge of the canopy is secured to the side of the vehicle while the other edge is secured to a roll bar mounted in a housing secured to the slide-out unit so that the roll bar is moved away from the vehicle as the cover is extended and retracted toward the side of the vehicle as the cover is retracted. The housing includes a pivotal and removable closure plate providing easy access to the roller for maintenance and for the removal of debris that accumulates on the canopy and is captured in the housing when the cover is retracted.
[0003] 2. Description of the Relevant Art
[0004] Mobile homes have been a mainstay for housing for many years and in more recent years motor home type structures have been used and are commonly referred to recreational vehicles. Similarly, trailers incorporating features of a recreational vehicle are becoming more popular and in each instance, it has become desirable to have the main body of the mobile home, recreational vehicle, trailer, or the like, expandable to selectively enlarge the living space within the vehicle. In order to accommodate such enlargement, mobile homes, recreational vehicles, trailers, and the like, are now sometimes provided with a slide-out unit which is a box-like structure having top and bottom walls as well as side walls and an outer wall with the box-like structure being motor driven between a retracted position within the interior of the vehicle and an extended position away from one side of the vehicle.
[0005] A common problem encountered with slide-out units resides in the fact that debris, such as leaves, dust, dirt, or the like, will accumulate on the top wall of the slide-out unit when the unit is extended. When the unit is subsequently retracted, the debris is brought into the interior of the vehicle. To avoid debris being brought into the vehicle during a retraction of a slide-out unit, covers have been provided over the top of the unit which extend with the slide-out unit and also retract with the unit. Any debris accumulating on the cover is therefore discarded as the unit retracts and the cover is rolled into a housing typically provided on the side of the vehicle.
[0006] An example of an extendible cover for slide-out units is found in U.S. Pat. No. RE37,567, which is of common ownership with the present application, and while the system disclosed in this patent overcomes some problems that were previously prevalent with the use of slide-out units, the solutions have not been entirely satisfactory as the cover is flat when extended and generally coextensive with the top of the slide-out unit so that debris, rain, and the like will accumulate on the cover. An improvement is found in copending application Ser. No. 10/964,840 filed Oct. 13, 2004 entitled Awning Cover for Slide-Out Unit for Recreational Vehicles, which is also of common ownership with the present application. In the cover disclosed in that application, the canopy component of the cover is raised at an intermediate location as the cover is extended so as to form a gable-like configuration encouraging debris and the like to be automatically discarded from the cover.
[0007] All debris is not discarded during retraction of the awning even in an awning of the type described and disclosed in application Ser. No. 10/964,840, and, accordingly, it would be desirable to provide a system whereby such debris could be more effectively prevented from being brought into the interior of the vehicle upon retraction of the awning.
[0008] It is to provide improvements in awning covers for slide-out units solving the problems raised above that the present invention has been developed.
BRIEF SUMMARY OF THE INVENTION
[0009] A cover for a slide-out unit on a mobile home, recreational vehicle, travel trailer, or the like, includes a canopy having one edge secured to the side of the vehicle and the other edge to a roll bar mounted to the outer wall of the slide-out unit. The canopy is adapted to be wrapped about the roll bar when the slide-out unit and the cover are moved into a retracted position and unwrapped from the roll bar when extended.
[0010] The roll bar is mounted in an aesthetically attractive housing and a support system, which may be of the type described in the afore-noted U.S. patent application Ser. No. 10/964,840, supports the canopy in a gabled configuration between the side of the vehicle and the outer wall of the slide-out unit where the roll bar is mounted.
[0011] The housing for the roll bar has a mounting bar extending along its length with the mounting bar being at least as wide as the slide-out unit but can extend any distance beyond the side walls of the slide-out unit to accommodate larger canopies if desired. The mounting bar is designed to be connectible to any number of mounting brackets on the outer wall of the slide-out unit depending upon the length of the cover and the width of the slide-out unit.
[0012] End caps are secured to the ends of the mounting bar and rotatably support the roll bar, which is spring-biased and in which the outer edge of the canopy is secured in a conventional manner. At least one intermediate support member may be removably connected to the mounting bar at any desired location along the length of the mounting bar to prevent sagging of the roll bar particularly on relatively long roll bars and wide slide-out units. The intermediate support member has rollers adapted to engage the canopy as it is wrapped around the roll bar to prevent sagging of the roll bar and therefore assure a smooth deployment and retraction of the canopy.
[0013] The housing has a closure plate or panel pivotally and removably connected to the end caps to conceal the roll bar during normal operation. The closure plate can be pivoted open or completely removed from the remainder of the housing to expose the roll bar for maintenance purposes or to remove debris that may accumulate within the housing as the cover is retracted and the canopy is wrapped around the roll bar. In other words, while the canopy is preferably mounted in a gable configured manner as described in the afore-noted U.S. patent application Ser. No. 10/964,840 so that debris is encouraged to naturally slide off the canopy, any remaining debris will drop off the canopy as it wraps around the roll bar so that such debris can be captured within the housing and removed therefrom by pivotally opening or removing the closure plate.
[0014] Other aspects, features, and details of the present invention can be more completely understood by reference to the following detailed description of the preferred embodiment, taken in conjunction with the drawings and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an isometric of a recreational vehicle having an extended slide-out unit incorporating the cover of the present invention.
[0016] FIG. 2 is a rear elevation of the recreational vehicle as shown in FIG. 1 .
[0017] FIG. 3 is an enlarged fragmentary isometric showing the slide-out unit along with the cover of the present invention in a retracted position.
[0018] FIG. 4 is an enlarged fragmentary isometric similar to FIG. 3 with the slide-out unit and cover in an extended position.
[0019] FIG. 5 is a further enlarged fragmentary section taken along line 5 - 5 of FIG. 4 .
[0020] FIG. 6 is a further enlarged fragmentary section taken along line 6 - 6 of FIG. 3 .
[0021] FIG. 7 is a section similar to FIG. 6 with the cover partially extended and with the cover plate in a closed position.
[0022] FIG. 8 is an isometric looking downwardly on the partially extended cover as shown in FIG. 7 with the canopy removed to show the support system for the cover.
[0023] FIG. 9 is an isometric similar to FIG. 8 with the cover further extended.
[0024] FIG. 10 is an enlarged fragmentary section taken along line 10 - 10 of FIG. 11 .
[0025] FIG. 11 is a fragmentary isometric looking at the top edge of the slide-out unit along its juncture with the side of the recreational vehicle illustrating the mounting brackets on the vehicle and the slide-out unit.
[0026] FIG. 12 is an enlarged section with parts removed taken along line 12 - 12 of FIG. 7 .
[0027] FIG. 13 is a fragmentary section taken along line 13 - 13 of FIG. 12 .
[0028] FIG. 14 is a fragmentary section taken along line 14 - 14 of FIG. 12 .
[0029] FIG. 15 is a fragmentary section taken along line 15 - 15 of FIG. 12 .
[0030] FIG. 16A is an exploded isometric showing the left end of the roll bar and its housing.
[0031] FIG. 16B is an exploded isometric similar to FIG. 16A showing the right end of the housing for the roll bar.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Referring to FIGS. 1 and 2 , a recreational vehicle 20 having a slide-out unit 22 in an extended position is shown with the retractable cover 24 of the present invention interconnecting a side wall 26 of the vehicle with an outer wall 28 of the slide-out unit. In FIGS. 3 and 4 , the slide-out unit is shown retracted and extended, respectively, with the cover of the present invention shown retracted and extended accordingly.
[0033] As best seen in FIGS. 3-5 , the retractable cover can be seen to include a support system 30 anchored with mounting brackets 32 to the side wall 26 of the recreational vehicle immediately above the opening in the side wall of the vehicle in which the slide-out unit is disposed. The support system includes pivotally interconnected support arms 34 which extend and retract in a scissors-type manner when the cover is extended and retracted respectively. Along the outer edge of the support system, a housing 36 for a roll bar 38 is provided with the housing being connected to the outer edge of the support system and to support brackets 40 on the outer wall 28 of the slide-out unit 22 adjacent the upper edge thereof. The roll bar is rotatably disposed within the housing and is anchored in a conventional manner to an outer edge of a flexible canopy 42 whose inner edge is anchored with a mounting rail 44 to the side wall of the vehicle immediately above the side wall mounting brackets 32 . As will be explained hereafter, the roll bar is spring biased toward a retracted position wherein the canopy is wrapped therearound with the biasing being in a clockwise direction as viewed in FIG. 5 . Accordingly, when the cover 24 is moved from the extended position of FIG. 5 to the retracted position of FIG. 3 , the canopy automatically wraps about the roll bar with the roll bar being drawn toward the side of the vehicle as the slide-out unit is retracted into the vehicle and as the scissors-type support arms collapse. The scissors-type support system could be of the type disclosed in detail in copending U.S. application Ser. No. 10/964,840 filed Oct. 13, 2004, which is of common ownership with the present application and which is hereby incorporated by reference herein.
[0034] It will be appreciated that the support system 30 is uniquely designed so that when fully retracted, as shown in FIG. 3 , the support arms 34 in the support system are folded in compact adjacent side-by-side relationship next to the side wall 26 of the recreational vehicle but as the slide-out unit is extended along with the housing 36 and its enclosed roll bar, the support system is extended and due to an angulated mounting of the support arms to brackets 46 at the distal ends of the support arms, a support beam 48 at the center of the support arms is elevated so as to create a gabled configuration for the canopy over the top of the slide-out unit. The gabled configuration encourages debris in the form of leaves, dust, rain, and the like, to naturally run or fall off the canopy so that when the slide-out unit is retracted the debris is kept off the top of the slide-out unit and is thereby prevented from being drawn into the recreational vehicle. As will be explained hereafter, to the extent any debris does not naturally run off the canopy in its extended position, the debris will accumulate within the housing 36 for the roll bar 38 as the canopy is wrapped around the roll bar and can be removed from the housing in a convenient manner.
[0035] The inner edge of the canopy 42 is secured to the side wall 26 of the recreational vehicle with the mounting rail 44 which is an elongated continuous rail having a groove of C-shaped cross section adapted to conventionally receive a hem in the inner edge of the canopy with a retaining rod therein. As possibly best seen in FIGS. 7, 9 , 10 , and 11 , the scissors support arms 34 for the support system 30 are mounted on a pair of the mounting brackets 32 with the inner end of an inner arm in the support system being mounted on a pivot bracket 46 which in turn is secured to an associated mounting bracket 32 on the side wall of the vehicle.
[0036] Each mounting bracket 32 as best seen in FIGS. 6, 7 and 10 has a vertical flange 49 securable to the side wall 26 of the vehicle with a suitable fastener 50 and a lower out turned arm 52 having an upwardly opening ridged groove 54 so that a fastener 56 as best shown in FIG. 7 can be passed through the pivot bracket 46 of the support system and into the upwardly opening groove to secure the pivot bracket to the mounting bracket 46 . It should also be appreciated in the support system, that each of the scissors arms 34 is distinguishable from those utilized in the afore-mentioned U.S. application Ser. No. 10/964,840, which has been incorporated by reference in that the arms in the present disclosure are made to be telescoping and can be fixed at any predetermined length with set screws 58 so that one adjustable support system 30 can be used to accommodate various sized covers 24 . In other words, each scissors arm remains of a fixed length once the size of the cover has been determined but due to the adjustable length of the scissors arm, they can be used in various sized covers.
[0037] The housing 36 for the roll bar 38 is mounted on the outer wall 28 of the slide-out unit with two or more of the support brackets 40 best seen in FIGS. 6, 7 and 10 , the number of which would depend on the length of the housing and thus the support felt necessary for the housing. In the disclosed embodiment, there are two such support brackets shown with one bracket being near one side edge of the outer wall 28 and the other near the opposite side edge. The support brackets are identical and are extruded into a fairly short length that may be for example six inches to a foot in length. Each bracket has a recess 62 near its lower edge with an opening therethrough to receive 64 fasteners that secure the bracket to the outer wall of the slide-out unit. A decorative cover strip 66 , as seen in FIG. 7 , may be snapped into the recess to cover the fasteners for aesthetic purposes. The bracket 40 extends upwardly in spaced relationship from the outer wall 28 of the slide-out unit and has a lower upwardly opening channel 68 formed on its outer face. Above the lower opening channel, the bracket has a horizontal leg with an upper upwardly opening channel 70 adjacent to its outer edge. The lower 68 and upper 70 channels are used to hang and secure the housing 36 to the bracket as will be described later.
[0038] The housing 36 , which is probably best seen in FIGS. 6, 7 , 16 A and 16 B, has an extruded base rail 72 of a length substantially the same as the width of the canopy. It is to be appreciated the length of the base rail and the width of the canopy can be much greater than the width of the slide-out unit if desired so that the canopy 42 can extend beyond the sides of the slide-out unit to prevent rain water from blowing beneath the canopy onto the top of the slide-out unit.
[0039] The extruded base rail 72 can be seen to be of generally triangular tubular cross section having a somewhat arcuate upwardly concave top wall 74 along its forward edge and an upwardly opening groove 76 extending along its length approximately midway between a front edge 78 and rear edge 80 . Immediately behind the upwardly opening groove 76 , there is an upper horizontal shelf 82 with a downturned lip 84 adapted to be seated in the upper channel 70 of a support bracket 40 . Immediately beneath the upper shelf there is a lower rearwardly projecting shelf 86 having a downturned lip 88 adapted to be received in the lower channel 68 of a support bracket 40 . A pair of C-shaped, inwardly opening grooves 90 ( FIGS. 6 and 7 ) are formed in the interior of the extruded base rail along the front edge 78 and along the rear lower edge 80 with the C-shaped grooves opening through opposite ends of the extruded base rail. The C-shaped grooves are adapted to receive fasteners 92 to secure end caps 94 and 96 to opposite ends of the extruded base rail 72 as possibly best seen in FIGS. 16A and 16B . A third C-shaped groove 98 is provided along the length of the base rail on the front of the upwardly opening groove 76 . The third groove is also open at opposite ends of the base rail to again receive a fastener 92 for securing the end caps to the base rail ( FIGS. 16A and 16B ).
[0040] A closure plate or panel 100 as possibly best seen in FIG. 16B is arcuate in cross-section so as to be outwardly convex when mounted on the end caps 94 and 96 . The top edge of the closure plate has an inwardly projecting groove 102 of C-shaped cross section which opens through opposite ends of the closure plate. Each open end of the groove 102 receives a depressible pin 104 mounted on a compression spring 106 . The pins are removably receivable in the groove 98 at the top of the end caps 94 and 96 so that the closure plate can pivot about the pins relative to the end caps. Depression of at best one of the pins facilitates removal of the closure plate from the end caps.
[0041] The closure plate 100 as best seen in FIGS. 6 and 7 has a pair of grooves 108 and 102 of C-shaped cross-section along its lower edge. One of the grooves 108 receives a rubber rod 112 that engages the front edge 78 of the base rail 72 when the closure plate is closed as shown in FIG. 7 and the other groove 102 receives depressible pins 114 as along the upper edge of the closure plate. The depressible pins are removably positionable in aligned holes 116 in the end caps. The pins are depressed either to allow the closure plate to pivot about the pins or to permit removal of the closure plate from the remainder of the housing.
[0042] The extruded base rail 72 is probably best seen in FIG. 7 hung on the support brackets 40 by positioning the downturned lips 84 and 88 on the extruded base rail into the upper 70 and lower 68 channels of the support brackets and then positively securing the base rail in place by advancing friction screws 117 into a space between the upper downturned lip 84 and a side wall of the upper channel 70 in the support brackets. It will be appreciated that the support brackets can be short relative to the length of the housing for aesthetics and cost savings. Further, the support brackets can be placed at any desired location along the length of the housing and any number of brackets can be used.
[0043] Before describing in detail the roll bar 38 which is rotationally mounted on the opposed end caps 94 and 96 of the housing, it should be noted that an intermediate roll bar support 118 ( FIG. 16B ) is also mounted on the extruded base rail 72 at any desired position. There may also be more than one such intermediate support mounted on the base rail depending upon the length of the roll bar and the amount of sag that might be expected due to the length and weight of the roll bar.
[0044] An intermediate support 118 is shown in FIG. 16B to include an arcuate main body 120 having open C-shaped grooves 122 along the top and bottom edges of its concave side for receipt of pivot shafts 124 that have rollers 126 mounted thereon on opposite sides of the main body. The main body has a rearwardly directed, horizontal flange 128 with a downturned lip 130 that is secured to the base rail 72 by passing fasteners 132 through the horizontal flange 128 and into the upwardly opening grooves 76 along the top edge of the extruded base member. The downturned lip 130 from the horizontal flange rests on the upper horizontal shelf 82 of the extruded base member so that the intermediate support 118 member is positively and securely supported on the base rail and in a position to have the rollers 126 engage the roll bar or the canopy when at least partially wrapped around the roll bar to provide support and prevent sagging of the roll bar along its length. If the roll bar is not retained in a straight line, the canopy will sag and collect rain water or the like in an undesirable manner when the canopy is extended. The intermediate support member(s) 118 prevent such sagging of the roll bar and thus any uneven distribution of the canopy.
[0045] Referring next to FIGS. 12-15 , 16 A, and 16 B, the construction of the roll bar 38 and its mounting in the housing 36 is illustrated. Referring first to FIGS. 16A and 16B , the roll bar can be seen to include a generally cylindrically shaped tube 134 having a pair of slots 136 formed in its outer surface ( FIGS. 5, 6 , and 7 ) which open into inward longitudinally extending protrusions 138 along the length of the cylindrical tube. The outer edge of the canopy 42 is anchored in one of the inward protrusions 138 through an associated slot in the same manner. The inner edge of the canopy is anchored to the side wall 26 of the vehicle with a hem and a retaining rod inserted into the inward protrusion.
[0046] The left end of the cylindrical tube as viewed in FIG. 16A has a cylindrical insert 140 frictionally fit therein and held in place with screws 142 passing radially inwardly through the wall of the cylindrical tube and into one of a plurality of notches 144 formed in the insert. The insert has a cylindrical passage therethrough which rotatably receives a bearing member 146 that protrudes completely through the insert and is retained in that position by a washer 148 and C-clamp 150 as possibly best seen in FIG. 12 . The bearing frictionally receives an axial press nut 152 in an opening in its outermost end into which a threaded fastener 154 can be received. The threaded fastener 154 passes through a boss in the inner surface of the associated end cap 94 so that the cylindrical tube is allowed to rotate freely about the bearing.
[0047] Referencing FIGS. 12-15 and 16 B, the right end of the roll bar can be seen to include an insert 140 identical to the insert at the left end which is again held in place with screws 142 extending radially inwardly through the wall of the cylindrical tube 134 and into a notch 144 in the insert. A spring tensioner 156 is inserted through the circular passage through the insert 140 and is retained in position with a washer 158 and C-clamp 160 as best seen in FIG. 12 . The spring tensioner has a generally cylindrical extension 162 extending inwardly from the insert with the generally cylindrical extension having a longitudinally extending notch 164 ( FIG. 14 ) in one surface. A coil spring 166 shown in FIGS. 12 and 16 A has its right end seated on the cylindrical extension 162 and a tang at the associated end of the spring 166 is received in the notch 164 to prevent rotation of the spring relative to the spring tensioner.
[0048] The opposite end of the coil spring is seated on an anti-rotation device 168 ( FIGS. 15 and 16 A) having a generally cylindrical shaft 170 with a notch 172 formed therein so that the tang at the associated end of the spring 166 can be received in the notch to prevent the spring from rotating relative to the anti-rotation device. The anti-rotation device also has diametrically projecting tabs 174 defining an overall diameter of the device slightly smaller than the interior diameter of the cylindrical tube 134 , but large enough so that the tabs engage the inward protrusions 138 in the tube which thereby prevent the anti-rotation device from rotating relative to the tube. Accordingly, it will be appreciated that the innermost end of the spring, having the anti-rotation device thereon, is fixed relative to the tube for rotation therewith whereas the opposite or outer end of the spring, which is anchored to the tensioner 156 , is allowed to rotate relative to the tube. The tensioner as best seen in FIG. 13 has four arcuately tapered teeth 176 around its outer periphery which are adapted to engage a pawl 178 pivotally mounted on a stub shaft 180 ( FIG. 13 ) projecting inwardly from the associated end cap 96 at the right end of the roll bar. The roll bar can be rotated in a clockwise direction as viewed in FIG. 13 which allows the spring 166 to be tensioned and the pawl holds the tensioner in any one of four selected positions as the cylindrical tube is rotated with the tensioner. This system is used to pre-tension the roll bar depending upon the size of the canopy 42 and its extension from the side of the recreational vehicle. In other words, the tension in the roll bar which biases the roll bar toward the retracted position of the cover can be selected so that the ideal amount of bias is placed on the roll bar to allow the canopy to desirably wrap about the cylindrical roll bar as the cover is moved from the extended to the retracted position.
[0049] The coil spring 166 is supported along its length by a support rod 182 ( FIGS. 12 and 16 ), which is seated within the tensioner 156 at one end and the anti-rotation device 168 at the other end. A ball bearing 184 is positioned at each end of the support rod so as not to inhibit free rotation of the spring.
[0050] It will be appreciated from the above that a cover 24 for a slide-out unit 22 in a recreational vehicle, 20 travel trailer or the like has been described which includes a housing 36 around the roll bar 38 for the canopy wherein the housing has a removable closure panel 100 so that easy access to the interior of the housing and its connection to the roll bar and support system 30 are obtained. Further, opening of the housing permits debris to be removed from the housing which may have accumulated during a retraction of the cover. The cover is also easily mountable on the recreational vehicle on relatively short mounting brackets 46 for improved aesthetics and cost savings and the roll bar itself can be made of a length which is considerably longer than the width of the slide-out unit inasmuch as the support brackets 60 for the roll bar housing can be positioned at any location along the length of the housing.
[0051] Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example, and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.
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A retractable cover for a slide-out unit on a recreational vehicle, mobile home, travel trailer, or the like, includes a roll bar that is movable with the slide-out unit away from the side of the vehicle with the roll bar mounted in a housing having a closure plate which is easily pivoted to an open position or removed to facilitate maintenance or removal of debris that may accumulate in the housing during a retraction of the cover. The housing is mounted on the slide-out unit with brackets permitting the brackets to be located at any position along the length of the housing and also permitting the housing to assume a length that is much greater than the width of the slide-out unit providing a better cover for the slide-out unit during inclement weather.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to variable frequency AC motors and more particularly, to a method and apparatus to compensate for voltage deviations at motor terminals due to switching time delays in pulse width modulated invertors.
One type of commonly designed induction motor is a three phase motor having three Y-connected stator windings. In this type of motor, each stator winding is connected to an AC voltage source by a separate supply line, the source providing time varying voltages across the stator windings. Often, an adjustable speed drive (ASD) will be positioned between the voltage source and the motor to control motor speed by controlling the stator voltages and frequency.
Many ASD configurations include a pulse width modulated (PWM) inverter consisting of a plurality of switching devices. Referring to FIG. 1, an exemplary PWM inverter leg 10 corresponding to one of three motor phases includes two series connected switches 12, 13 between positive and negative DC rails 18, 19 and two diodes 16, 17, a separate diode in inverse parallel relationship with each switch 12, 13. By turning the switches 12, 13 ON and OFF in a repetitive sequence, leg 10 receives DC voltage via rails 18 and 19 and provides high frequency voltage pulses to a motor terminal 22 connected to a stator winding 24. By firing the switching devices in a regulated sequence the PWM inverter can be used to control both the amplitude and frequency of voltage that are eventually provided across windings 24.
Referring to FIG. 2, an exemplary sequence of high frequency voltage pulses 26 that an inverter might provide to a motor terminal can be observed along with an exemplary low frequency alternating fundamental voltage 28 and related alternating current 30. By varying the widths of the positive portions 32 of each high frequency pulse relative to the widths of the negative portions 34 over a series of high frequency voltage pulses 26, a changing average voltage which alternates sinusoidally can be generated. The changing average voltage defines the low frequency alternating voltage 28 that drives the motor. The low frequency alternating voltage 28 in turn produces a low frequency alternating current 30 that lags the voltage by a phase angle Φ.
The hardware which provides the firing pulses to the PWM inverter is typically referred to as a signal generator. Referring to FIG. 3(a), illustrative waveforms used by a signal generator to generate the firing pulses for leg 10 may be observed. As well known in the art, a carrier waveform 36 is perfectly periodic and operates at what is known as the carrier frequency. A command voltage waveform 38 is sinusoidal, having a much greater period than the carrier waveform 36.
Referring also to FIGS. 3(b) and 3(c), an ideal upper signal 40 and an ideal lower signal 42 that control the upper and lower switches 12, 13 respectively can be observed. The turn-on t u1 , t u2 and turn-off t o1 , t o2 times of the upper and lower signals 40, 42 come from the intersections of the command waveform 38 and the carrier waveform 36.
When the command waveform 38 intersects the carrier waveform 36 while the carrier waveform has a positive slope, the upper signal 40 goes OFF and lower signal 42 goes ON. On the other hand, when the command waveform 38 intersects the carrier waveform 36 while the carrier waveform has a negative slope, the upper signal 40 goes ON and the lower signal 42 goes OFF. Thus, by comparing the carrier waveform 36 to the command waveform 38, the state of the upper and lower signals 40, 42 can be determined. The upper and lower signals 72, 74 are provided to the delay module 11.
Referring also to FIGS. 2 and 3(d), an ideal high frequency voltage pulse 26 resulting from the ideal upper and lower signals 40, 42 in FIGS. 3(b) and 3(c) that might be provided at terminal 22 can be observed. When the upper signal 40 is ON and the lower signal 42 is OFF, switch 12 allows current to flow from the high voltage rail 18 to motor terminal 22 thus producing the positive phase 44 of pulse 26 at motor terminal 22. Ideally, when the upper signal 40 goes OFF and the lower signal 42 goes ON, switch 12 immediately turns OFF and switch 13 immediately turns ON connecting motor terminal 22 and the low voltage rail 19 producing the negative phase 46 of pulse 26 at terminal 22. Thus, the ideal high frequency voltage pulse 26 is positive when the upper signal 40 is ON and is negative when the lower signal 42 is ON.
While advanced digital electronic signal generators can produce the desired high frequency signals to turn inverter components ON and OFF, the inverter components cannot turn ON and OFF instantaneously. Ideally, when one switch 12 turns on, the series switch 13 turns OFF, and visa versa.
In reality, however, each switch 12, 13 has turn-on and turn-off times that vary depending on the technology used for their construction. Thus, while signals to turn the upper switch 12 ON and the lower switch 13 OFF might be given at the same instant, the lower switch 13 may go OFF slower than its command leading to a condition where both switches are conducting thus providing an instantaneous DC short between a high DC rail 18 and a low DC rail 19. Such a DC short can cause irreparable damage to both the inverter and motor components.
To ensure that the series switches of an inverter are never simultaneously on, a delay module is typically provided to introduce a turn-on delay between the times when one switch turns off and the other switch turns on. The delay module modifies the upper and lower signals 40, 42 by adding a turn-on delay period γ prior to the turn-on times t u1 , t u2 of each of the upper and lower signals 40, 42. Referring to FIGS. 3(e) and 3(f), the delay periods γ produce delayed and shortened upper and lower signals 40' and 42' having delayed turn-on times t u1 ', t u2 '.
Referring to FIG. 3(g), while the delay periods γ protect the motor and inverter components, they produce voltage deviations ζ n at the motor terminal 22 that produce distorted positive and negative phases 48, 50 and a distorted high frequency voltage pulse 52. These deviations ζ n can best be understood by referring to FIGS. 1, 2, and 3(e)-3(g).
Referring to FIGS. 1, 2 and 3(e)-3(g), while the terminal current 30 at motor terminal 22 might be positive, the high frequency voltage pulses 26 will be oscillating from positive to negative phase as the delayed upper and lower signals 40', 42' turn the switches 12, 13 ON and OFF. Thus, while the terminal current 30 is positive, two signal states may occur. First, the upper signal 40 may be OFF while the lower signal 42 is ON and second the upper signal 40 may be ON while the lower signal 42 is OFF. Likewise, when the current 69 is negative, the same two signal states may exist.
When the terminal current is positive and switch 12 is ON while switch 13 is OFF, the high voltage rail 18 is connected to motor terminal 22. Diode 17 blocks the flow of current to the low voltage rail 49. When the upper switch 12 turns OFF at t 01 , both series switches 12, 13 remain OFF during the delay period γ. As well known in the art, motor winding 24 operates as an inductor at terminal 22. Because of motor winding inductance, current 30 caused by voltage 28 cannot change directions immediately to become negative each time the high frequency voltage pulse 26 changes from the positive 32 to the negative 34 phase. The current remains positive and diode 17 immediately begins to conduct at t o1 connecting the low voltage rail 19 to terminal 22 as desired. Hence, the terminal voltage goes negative at the desired time t o1 even though the turn-on time t u2 of the delayed lower signal 42' does not occur until after the delay period γ.
On the other hand, when switch 12 is initially OFF and switch 13 is ON and the terminal current 30 is positive, the low voltage rail 19 is connected through switch 13 to terminal 22 as desired and the resulting terminal voltage pulse 52 is in the negative phase 50. When switch 13 turns OFF at t o2 , as the positive terminal current 30 cannot immediately reverse itself, diode 17 conducts and low voltage rail 19 is again connected to terminal 22 for the duration of delay period γ. Thus, during the delay period γ, instead of having positive phase voltage at terminal 22 as desired, the negative phase 50 of the resulting terminal voltage pulse is extended until the turn-on time t u1 ' of delayed upper signal 72'.
Comparing FIGS. 3(d) and 3(g), the resulting terminal voltage pulses 52 have wider negative phases 50 and narrower positive phases 48 than the ideal voltage pulses 26. A voltage deviation ζ n occurs each time the lower switch 13 is turned OFF and the terminal current 30 is positive. As well known in the art a similar type of deviation ζ n of opposite polarity is produced when the terminal current 30 is negative and the upper switch 12 turns from ON to OFF.
While each individual deviation ζ n does not appreciably affect the fundamental alternating voltage, accumulated deviations do distort the low fundamental frequency alternating voltage 28 and resulting current 30 thereby causing undesirable torque pulsations. Referring to FIG. 4a, an ideal terminal voltage 28 and associated current 30, and an actual terminal voltage 54 generated without compensating for turn on delay periods are illustrated. While the ideal voltage 28 and current 30 are purely sinusoidal, the actual voltage 54 is distorted by the ζ n deviations. During positive terminal current 30 periods the actual voltage amplitude is reduced from the ideal amplitude by a value ΔV which can be expresses as:
ΔV=ζ.sub.n *V.sub.dc *f.sub.PWM Eq. 1
where V dc is the DC voltage and f PWM is the carrier frequency of the PWM inverter. Similarly, during negative terminal current 30 periods the actual voltage amplitude is increased from the ideal amplitude by ΔV.
To compensate for terminal voltage deviations related to turn on delays the industry has tried various methods of adding and subtracting correction waveforms to the command signals used by the signal generator to derive firing signals for the PWM inverter. For example, referring also to FIG. 4b, because terminal voltage deviations are periodic, a periodic correction voltage 69 can be added to the command signal prior to comparison to the carrier signal. During positive current 30 periods, because turn on delays reduce the output voltage by ΔV, by adding a correction voltage 69 equal to voltage ΔV to the command signal, the deviation should be compensated. Similarly, during negative current 30 periods, because turn on delays increase the output voltage by ΔV, by subtracting a correction voltage 69 equal to voltage ΔV from the command signal, the deviation should be compensated. Thus, the correction signal 69 is positive and equal to ΔV when current 30 is positive and is negative and equal to ΔV when current 30 is negative.
To implement this type of compensation, typically current sensors are provided which determine when a terminal current 30 crosses zero. Each time the current 30 crosses zero the correction voltage 69 is changed from positive to negative or vice versa, depending on the change in current 30 (i.e. when current 30 goes from negative to positive, correction voltage 69 goes positive and when current 30 goes from positive correction voltage to negative, correction voltage 69 goes negative).
This type of turn on delay compensation works well when the precise time of the current 30 zero crossings can be determined. Unfortunately, limitations inherent in the PWM system often make it difficult to precisely determine current zero crossing times.
Referring to FIG. 5a, a zero crossing of a typical terminal current 30 has been enlarged. While the overall shape of current 30 is essentially sinusoidal (see FIG. 4a), because the current is generated using a PWM inverter it will typically include instantaneous ripple oscillating up and down about an average sinusoid. During a zero crossing period T z , because of ripple, current 30 does not cleanly cross the zero value at a single instant in time. In fact, current 30 crosses the zero value several times during each zero crossing period T z as it oscillates between positive and negative values about zero. For this reason current 30 tends to remain approximately zero during period T z .
Referring also to FIG. 5b, each time current 30 crosses zero, the polarity of correction voltage 69 changes to compensate for turn on delays. Thus, during zero crossing period T z , voltage 69 oscillates between plus and minus ΔV values. Correction voltage oscillation in itself is not objectionable, after all, when current 30 is positive it is advantageous to have a positive correction voltage and when current 30 is negative it is advantageous to have a negative correction voltage to compensate for current through diodes 17 and 19. However, because diodes 17 and 19 do not conduct efficiently during the zero crossing period T z , instead of correcting for turn on delays during periods T z , causes further distortion.
For example, referring to FIGS. 1 and 5a, assume the magnitude of current 30 between times t 1 and t 2 is insufficient to turn on diode 17 when switches 12 and 13 are both OFF. In this case the diode 17 does not cause an error ζ n during the turn on delay. However, because current 30 is positive between times t 1 and t 2 , the command voltage and hence the terminal voltage are increased by the correction angle resulting in a terminal voltage distortion.
One way to reduce period T z distortion is to filter the current signal 30 to reduce the ripple. A filtered signal 30' is illustrated in FIG. 5a. While the filtered signal 30' reduces correction voltage oscillation about the zero crossing, the current 30' still remains at approximately zero during the zero crossing period T z which makes it extremely difficult to determine a correct zero crossing time for turn on delay compensation purposes.
Current sampling speed is limited by both hardware and software and therefore, while an ideal zero crossing time may be t 3 , typical current sensors may detect the zero crossing to be any time within the zero crossing period T z .
Thus, it would be advantageous to have a system which can accurately compensate for turn on delay distortion by increasing accuracy of current zero crossing detection and compensating for remaining zero crossing error.
BRIEF SUMMARY OF THE INVENTION
The present invention includes an apparatus having a phase locked loop (PLL) for determining accurate current zero crossing times which are used by a turn on delay compensator to add correction voltages to command signals for generating desired terminal voltages. However, because of current sensing limitations, zero crossings can not be precisely determined and therefore terminal voltage distortions cannot be completely compensated in this manner. Therefore, the present invention also includes a correction module which receives a current phase error signal from the PLL and uses the error signal to derive a second correction voltage which is also added to the command voltage to better compensate for voltage distortion.
Referring again to FIG. 2, during steady state operation the single phase current 30 should be completely sinusoidal such that the phase angle Φ remains constant. However, referring also to FIG. 5a, current 30 remains approximately zero during the zero crossing period T z . This imperfection in the crossing causes a decrease in the instantaneous current frequency which means that phase angle Φ also deviates from its steady state value during periods T z .
Referring also to FIG. 6, as well known, the three separate stator currents can be visualized as a single current vector i s a two axis Cartesian reference frame. The same can be said for the vector representing the three fundamental components of the stator voltages V s . In steady state, both vectors rotate about the Cartesian reference frame at a vector frequency f v . The current vector i s lags the voltage vector V s by a power factor angle φ pf .
As vector i s rotates, it forces a phase angle ρ 1 with respect to one of the axis of the Cartesian reference frames (e.g. the q-axis). When one of the currents passes through zero during a zero crossing period, angle ρ 1 deviates from its steady state rate of change. This instantaneous deviation of the angle ρ 1 causes also a change of the power factor angle φ pf which causes instantaneous and periodic deviations in the produced motor torque. By increasing stator voltages just prior to an associated phase current crossing zero, the associated zero crossing period T z is essentially eliminated or is at least substantially reduced so that there is less zero crossing error. By monitoring angle ρ 1 , zero crossing errors can be identified and then compensated via the second correction voltage.
The second correction voltage is used to compensate the voltage associated with the next current to cross through zero and thereby substantially reduces the terminal voltage error.
Thus, one object of the present invention is to reduce the duration of the current zero crossing period T z . Another related object is to eliminate turn-on delay errors by providing turn-on delay compensation. Still another object is to provide turn-on delay compensation which is precise at current zero crossings such that the rate of change of phase angle ρ 1 (see FIG. 6) between current vector i s and torque current i qs remains constant, thus reducing torque ripple.
Other and further aspects and objects of the present invention become apparent during the course of the following description and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic of a single leg of a three phase PWM inverter;
FIG. 2 is a graph illustrating a high frequency pulse train applied to a stator winding and a resulting low frequency alternating voltage and current;
FIG. 3a is a graph illustrating the waveforms used by a PWM inverter to produce the high frequency pulses shown in FIG. 2, FIGS. 3b, 3c, 3e, and 3f are graphs illustrating PWM firing pulses, and FIGS. 3d and 3g are graphs illustrating high frequency pulses delivered to a motor terminal;
FIG. 4a is a graph illustrating ideal stator voltage and current and actual stator voltage prior to delay compensation and FIG. 4b is a graph illustrating a turn-on delay correction voltage;
FIG. 5a is a graph illustrating stator current and FIG. 5b illustrates turn-on delay correction voltage during a zero crossing period;
FIG. 6 is a graph depicting stator current and d and q-axis current components;
FIG. 7 is a schematic of the inventive controller;
FIGS. 7a and 7b are graphs illustrating motor parameters where the invention is not employed; and
FIGS. 8a and 8b are graphs similar to FIGS. 7a and 7b albeit where the invention is employed.
DETAILED DESCRIPTION OF THE INVENTION
A. Theory
Referring again to FIG. 6, the three stator voltages V u , V v and V w provided to drive a motor can be represented by a single voltage vector V s in a d and q frame of reference which rotates at a constant frequency during ideal steady ideal operation. Similarly, the three phase currents i u , i v and i w which are caused by phase voltages V u , V v and V w can be represented by a single two component current vector i s which lags voltage vector V s by angle Φ pf . Current vector i s includes two components, a first component i qs and a second component i ds which lags the first component by 90°. Vector i s rotates about the d-q frame of reference at vector frequency f v and as it rotates, a phase angle ρ 1 with a stationary reference changes.
The rate of change of angle ρ 1 should always remain constant during steady state motor operation. Unfortunately, each time one of the three stator currents i u , i v or i w passes through zero and levels off at approximately a zero level, the vector frequency f v of rotation of the vector is altered and the rate of change of angle ρ 1 deviates from its steady state value. The current disturbance reflected by the rate change results in undesirable torque pulsations.
To eliminate the torque pulsations the voltages which give rise to the stator currents i u , i v or i w can be altered to effectively force the resulting currents i u , i v and i w to cross through the zero level more rapidly so that the zero crossing period T z is either eliminated or substantially reduce each time a phase angle error is detected. To this end, at least two of the three stator currents i u , i v or i w are sensed and transformed into two phase stationary two-axis d-q currents i ds and i qs . These two current components represent a vector rotating in steady state at the frequency f v and with an angle ρ 1 with respect to the axis d of the d-q reference frame. From FIG. 6 it can be seen that:
i.sub.qs =i.sub.s cos ρ.sub.1 Eq. 2
and:
i.sub.ds =i.sub.s sin ρ.sub.1 Eq. 3
Instantaneous currents i ds and i qs are fed to a two axis phase locked loop (PLL) 92 in FIG. 7 which determines at its output, another vector i sPLL with constant amplitude and an angle ρ 2 with respect to the previously defined q axis. In steady state, and if the input currents ids and iqs are really sinusoidal, the angle ρ 1 and ρ 2 are identical and the input and output vector of the PLL will be rotating at the same vector frequency f v . However, where one of the phase currents i u , i s or i w crosses zero, due to the previously explained current distortion, the angular frequency of the input and output vector will be different and the phase angle ρ 1 will not be equal to ρ 2 .
The PLL performs the task of keeping the phase difference between the angle ρ 1 of the stator vector i s and of the output vector i sPLL to a minimum. To this end, the phase difference (ρ 1 -ρ 2 ) is calculated and fed to regulator 124 of FIG. 7. The outputs of the PLL, being of constant amplitude, could be considered to be the sine and cosine of the output angle ρ 2 . The phase angle comparison (ρ 1 and ρ 2 ) is accomplished by multiplying the sine of the angel ρ 2 by current i qs to generate a first factor, multiplying the cosine of angle ρ 2 by current i ds to generate a second factor, and subtracting the first from the second factor. In other words, error difference (ρ 1 -ρ 2 ) is being approximated by the following trigonometric equation:
i.sub.s sin (ρ.sub.1 -ρ.sub.2)=(i.sub.s sin ρ.sub.1)*cos ρ.sub.2 -(i.sub.s cos ρ.sub.1)*sin ρ.sub.2 Eq. 4
Combining Equations 2, 3 and 4:
i.sub.s sin (ρ.sub.1 -ρ.sub.2)=i.sub.ds cos ρ.sub.2 -i.sub.qs sin ρ.sub.2 Eq. 5
For small errors between the two angles, the sine function can be approximated by the value of the angle difference in radians such that Equation 5 reduces to:
i.sub.s sin (ρ.sub.1 -ρ.sub.2)∝i.sub.s (ρ.sub.1 -ρ.sub.2) Eq. 6
In the PLL, each time ρ 1 -ρ 2 is not zero, regulator 124 generates a frequency f VPLL different from f v .
It has been recognized that vector frequency errors are approximately proportional to voltage errors during the phase current zero crossings. Thus, according to the present invention, the frequency error from the PLL is used to reduce or eliminate the voltage errors in the phase which has a current crossing zero.
To compensate for the phase angle deviation, a voltage correction is added to, or subtracted from, the stator voltage associated with the current crossing zero. The additional voltage speeds up the zero crossing current transition and thus helps to eliminate the phase angle and vector frequency error, thus reducing torque pulsations.
B. Configuration
In the description that follows, an "*" denotes a "command" signal and an "s" subscript denotes that a signal is referenced to the stationary frame of reference.
Referring now to FIG. 7, the present invention will be described in the context of a motor drive 80 that receives a command frequency signal f* and produces voltages V u , V v and V w to drive a motor 82 at the command frequency f*. Drive 80 includes a command signal modulator 84, a PWM controller 86, a PWM inverter 88 and various other motor components which will be described in more detail below.
The inverter 88 includes a group of switching elements which are turned on and off to convert the DC voltage to pulses of constant magnitude. The inverter pulse train is characterized by a first set of positive going pulses of constant magnitude but of varying pulse width followed by a second set of negative going pulses of constant magnitude and of varying pulse width. The RMS value of the pulse train pattern approximates one cycle of a sinusoidal AC wave form. (See FIG. 2.) The pattern is repeated to generate additional cycles of the AC waveform. To control the frequency and magnitude of the AC power signals to the motor, control signals are applied to the inverter 88.
The control signals to drive the inverter 88 are provided by the PWM controller 86. Controller 86 receives three input signals and compares each of the input signals with a triangle carrier signal which has a much higher frequency than any of the input signals. When a sinusoidal input signal is greater than the carrier signal, a corresponding control signal provided to inverter 88 is high. When a sinusoidal input signal is less than the carrier signal, a corresponding control signal to inverter 88 is low.
The modulator 84 includes four different modules including a drive module 90, a phase locked loop (PLL) module 92, a dead time compensation module 94 and an angle correction module 96.
Drive module 90 includes five summers 97, 98, 99, 100 and 101, one integrator 102, three sine modules 104, 105 and 106, three multipliers 108, 109 and 110 and a voltage/frequency selector 112. Signal f* is provided to integrator 102 which integrates that signal and provides a phase angle to sine module 104, summer 98 and summer 99. Summer 98 phase shifts the phase angle by adding 120° while summer 99 phase shifts the phase angle by subtracting 120°. The outputs of summers 98 and 99 are provided to sine modules 105 and 106, respectively. Therefore, the angles provided to sine modules 104, 105 and 106 are all equispaced and separated from one another by 120 electrical degrees. The outputs of each of the sine modules 104, 105 and 106, are sine waveforms at the command frequency f* with a unity amplitude and which are out to phase by 120°.
Command signal f* is also provided to voltage/frequency selector 112 which correlates a command frequency with a suitable stator voltage, providing a stator voltage magnitude as an output. In most conventional controllers, the output of selector 112 would be provided to multipliers 108, 109 and 110 which would control the amplitude of the signals from sine modules 104, 105 and 106 accordingly.
In the present invention, however, the stator voltage magnitude from selector 112 is provided to phase angle correction module 96 which alters the stator voltage magnitude when necessary to compensate for turn on delay time which is not compensated via more conventional means. Module 96 will be described in more detail below.
The outputs of multipliers 108, 109 and 110 are provided to summers 97, 100 and 101 where each is added to a suitable turn on delay compensation signal which is provided by compensator module 94 to compensate for turn-on and turn-off delay times. The outputs of summers 97, 100 and 101 are then provided to PWM controller 86 and are used as the input voltages for comparison to the triangle carrier signal.
Referring still to FIG. 7, a single current feedback loop is provided. The feedback loop includes two or three current sensors (e.g., Hall affect sensors) collectively referred to by the numeral 114 which provide signals indicative of the three stator winding currents i u , i v and i w . The three currents are provided to PLL module 92, correction module 96 and compensation module 94.
The PLL module includes a three-to-two phase transformer 116, two multipliers 118, 120, two summers 122, 126, a proportional/integral PI regulator 124, an integrator 128, a sine module 130, a cosine module 132 and a limiter 134. Currents i u , i v and i w are provided to transformer 116 which transforms the three phase currents into two phase stationary d and q-axis currents i ds and i qs according to the following equation: ##EQU1##
The other components of the PLL module 92 implement Equation 6 above. To this end, currents i ds and i qs are provided by transformer 116. Integrator 128 provides phase angle ρ 2 to sine and cosine modules 130, 132, respectively, which provide the sine and cosine of phase angle ρ 2 , respectively. Thus, multiplier 118 receives current i qs from transformer 116 and multiplies current i ds by the sine of phase angle ρ 2 to provide a first factor as an output. Similarly, multiplier 120 receives current i ds from transformer 116 and it multiplies that current by the cosine of angle ρ 2 providing a second factor as an output. Summer 122 subtracts the first factor from the second factor providing an output which indicates when the stator current phase angle ρ 1 has deviated from the steady state angle ρ 2 .
The output of summer 122 will typically be zero. However, during current zero crossing periods when one of the three stator currents i u , i v or i w approximately levels off to zero for a short time, there will be a non-zero output at summer 122 (i.e. ρ 2 -ρ 1 ≠0) The non-zero output is provided to the PI regulator 124 which steps up the angle difference (ρ 1 -ρ 2 ) as a function of the magnitude of the difference and provides the stepped up value to summer 126.
In addition to the stepped up value, summer 126 also received the command signal f* which is indicative of the desired stator current frequency. In steady state signal f* will not change over time. Moreover, if ρ 1 =ρ 2 the output of PI regulator 124 will be zero. Output of summer 126 is provided to integrator 128 which generates phase angle ρ 2 which is provided to sine and cosine modules 130, 132, respectively, as described above. The stepped up signal from the PI regulator 124 is also provided to a limiter 134 which limits the maximum value of the stepped up signal prior to providing that value to the correction module 96. The maximum value allowed by the limiter 134 is ΔV PLL .
Thus, PLL module 92 provided both a phase angle signal ρ 2 and another signal on line 200 as a limiter output which indicates when the phase angle has changed (i.e. when ρ 1 -ρ 2 ≠0)
Phase angle ρ 2 is provided to an angle discriminator 138. Although not shown, discriminator 138 typically will include two summers, one of which adds 120° to angle ρ 2 and another which subtracts 120° from angle ρ 2 . The discriminator 138 will also typically include a processor which can identify when the sine of any one of the three angle (i.e. ρ 2 , ρ 2 -120°, or ρ 2 +120) equals zero. When sine ρ 2 equals 0°, discriminator 138 generates a signal via line 140 indicating a zero crossing. When sine (ρ 2 -120°) equals zero, discriminator 138 generates a signal via line 142 indicating a zero crossing. Similarly, when sine (ρ 2 +120°) equals zero, discriminator 138 generates a signal via line 144 indicating a zero crossing. Outputs 140, 142 and 144 are provided to three OR-gates 146, 148 and 150, respectively.
Currents i u , i v and i w are also provided to a conventional zero crossing identifier 152 which simply tracks current polarity reversals and provides three outputs to OR-gates 146, 148 and 150, each output corresponding to a different one of the stator currents i u , i v and i w . Each OR-gate 146, 148 and 150 produces a separate signal indicating when either one or the other or both of its inputs have indicated a zero crossing and provides those signals to compensator 154. Compensator 154, in turn, generates signals like those illustrated in FIG. 4b to compensate for turn on delays in a conventional manner.
Referring still to FIG. 7, the correction module 96 includes a minimum current selector 160, three switches 162, 164 and 166, three summers 168, 170 and 172, and three multipliers 174, 176 and 178. The current selector 160 determines which of the three stator line currents i u , i v or i w has the smallest absolute value and outputs a trigger signal to one of the switches 162, 164 or 166 corresponding to the stator current having the minimum absolute value. When one of the switches 162, 164 or 166 receives a signal, the switch is closed providing the limiter output on line 200 to an associated summer 168, 170 or 172. Each of the summers 168, 170 or 172 also receives a unity input which is added to either zero (when an associated switch 162, 164 or 166 is not closed) or is added to the limiter output (when an associated switch is closed).
The outputs of summers 168, 170 or 172 are provided to multipliers 174, 176 and 178 where the voltage magnitude signal from module 112 is multiplied by each of those values. The outputs of multipliers 174, 176 and 178 are provided to multipliers 108, 109 and 110 to set the amplitudes of command signals provided to summers 97, 100 and 101.
C. Operation
During steady-state operation, when none of the three stator winding currents are crossing zero, the current vector frequency will equal the command frequency f* and therefore the phase angles ρ 1 and ρ 2 will be equal. In this case, referring still to FIG. 7, the output of summer 122 will equal zero, the output of PI regulator 124 will equal zero and the input to all three summers 168, 170 and 172 will be zero. In this case module 96 will not effect motor operation.
However, as one of the stator winding currents i u , i v or i w begins to cross through zero and level off at an approximately zero level for a zero crossing time interval T z , the phase angle will change from its steady state level ρ 2 . In this case, the output of summer 122 will become non-zero, the output of regulator 124 will increase as a function of the summer 122 output magnitude, the input to one of the summers 168, 170 or 172 will be increased, depending on which is the next stator winding current to cross zero, and therefore the voltage associated with the next stator winding current to cross zero will be increased via multipliers 174, 176, 178, 108, 109 and 110.
In addition, referring still to FIG. 7, when there is an error in the phase angle which shows up as a non-zero output from summer 122, regulator 124 output is increased as a function of the error and provided to summer 126. At summer 126 frequency f* is increased by the output of regulator 124 which thereby increases angle ρ 2 via integrator 128. Thus, dead time compensation provided by compensator 154 is altered when the vector frequency is reduced which thereby helps to increase the vector frequency.
D. Results
Referring now to FIGS. 7a and 7b, current i s , phase angle ρ 1 and resulting torque T are illustrated as a function of time where correction module 96 was not employed and only discriminator 130 was used to identify zero crossing times for turn-on delay compensation purposes. In this case, the turn-on delays were assumed to be of the same duration and ΔV (see FIG. 4b) was used as the first correction voltage. The fundamental frequency of operation was 2 Hz and the PWM frequency f pwm was set to 4 kHz. At time=1 second a load torque of 0.2 P.U. was applied. The controller kept the commanded voltage and frequency constant (i.e. IR and slip compensation were not implemented).
At three clearly identifiable separate points t u , t v and t w during each half cycle of current i s the current i s levels off. These points t u , t v and t w each correspond to a different zero crossing of the three phase currents i u , i v and i w . Because current i s levels off, angle ρ 1 deviates from its steady state rate of change at the same times. In FIG. 7b the effect of the current leveling off at t u , t v and t w is seen clearly in the calculated motor torque T which pulsates each time current i s levels off.
Referring also to FIGS. 8a and 8b, current i s , phase angle ρ 1 and resulting torque T are again illustrated as a function of time. However, in this case, the inventive correction module 96 and PLL 92 are employed as described above.
In this case, clearly current i s does not level off appreciably during operation and the resulting torque T is almost devoid of ripple.
It should be understood that the methods and apparatuses described above are only exemplary and do not limit the scope of the invention, and that various modifications could be made by those skilled in the art that would fall under the scope of the invention. For example, while FIG. 6 shows components for determining zero crossings in two different ways (i.e. identifier 152 and PLL 92 in conjunction with discriminator 138), clearly the present invention could be practiced using components which determine the zero crossing points in a single manner. Most preferably, at start-up identifier 152 is used and thereafter, once iqs and ids reach steady state operation, only the PLL 92 and discriminator 138 are used. PLL 92 and discriminator 138 provide only a single zero crossing point for each current which crosses zero, not a zero crossing period T z . In addition, while separate components are described above, clearly a single microprocessor could and should be used to implement all functionality identified.
To apprise the public of the scope of this invention, we make the following claims:
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An apparatus for compensating for turn on delay distortions generated by a PWM controller. When turn on delay compensation is added to a PWM controller command signal and current zero crossings are inaccurately determined, compensation at the zero crossings causes further distortion which is reflected in a d and q-axis current vector frequency. Deviations from an ideal vector frequency are identified and used to modify command voltages to eliminate the zero crossing errors.
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This invention relates to transfer mechanisms and more specifically to a transfer device for progressively indexing workpieces between stations of a die mounted in a device.
BACKGROUND OF THE INVENTION
A transfer device comprises a base on which a workpiece carriage is slidably mounted for movement to successive work stations. The carriage in turn supports workpiece gripping fingers. Such transfer devices are disclosed, for example, in U.S. Pat. Nos. 3,165,192; 3,411,636 and 4,032,081. Such transfer devices are operated by the ram of a press through an actuator mounted on the carriage for reciprocation along a path parallel to the path of travel of the carriage on the base. The ram drives the actuator and further drives both the carriage and the workpiece engaging fingers through numerous gears. During travel of the actuator, the workpiece engaging fingers are moved inward or outward to engage or disengage a workpiece, depending upon the direction of travel of the actuator, and thereafter, the carriage is shifted on the base laterally with respect to the finger movement through a stroke corresponding to the distance between successive stations.
Such prior transfer devices incorporate a cam and/or a rack and pinion to drive an output shaft to actuate the carriage and work engaging fingers. With prior cam driven transfer devices, only 90° rotation of the output shaft was possible to drive the carriage and the work engaging fingers. As a result, the work engaging fingers, for example, start moving at a slow acceleration and end movement at the highest velocity resulting in high impact forces between the fingers and the workpieces. This produces wear of parts and subjects the device to shock with the possibility of damage. Rack and pinion drives allow 180° shaft rotation resulting in carriage and finger motion starting at a slow acceleration and decelerating at the end of movement to avoid backlash and high inertial forces. However, in order to achieve the 180° rotation, the rack must be excessively long requiring much space and, for example, interferes with changing of the die.
It is therefore a general object of the invention to provide a drive for each a carriage and for work engaging fingers that achieves optimum acceleration and deceleration through its range of motion to avoid damage caused by backlash and high inertial forces, that is an independent stand-alone assembly adapted for use with existing transfer devices, and that is compact and saves space.
SUMMARY OF THE INVENTION
The foregoing and other objects are obtained in accordance with the present invention in which the carriage and work engaging fingers are driven by separate drives actuated by a press ram. Each drive is compact and saves space by using a pluarality of interconnecting links to reciprocate the carriage and work engaging fingers and to achieve desired accelaration and deceleration. The drives comprise a housing having cam plates and a first link member that is driven at one end by the press ram to reciprocate therein. The other end of the first link member has a follower received in a slot at one end of a second link member. In the finger drive, the second link member has first and second cam followers. The first cam follower engages an outer cam surface of the cam plates while the second cam followers are received within cam slots in the cam plates. In the transfer drive, the second link member only has first cam followers received in a cam slot in the cam plates. The second link member of both drives has a bifurcated end that connects to a third link member that connects to an output shaft through a crankshaft. The output shaft of each drive is connected to the fingers and carriage, respectively, through a slotted drive plate. As the press ram reciprocates, the first link member reciprocates therewith to actuate the second and third link members, the crankshaft and thus the output shaft to drive the work engaging fingers and carriage, respectively.
The relationship between the cam plates and cam followers on the second link member allows the output shaft to be rotated a full 180°. The output shaft slowly accelerates at the beginning of rotation and decelerates at the end of rotation. Thus, both the fingers and the carriage are driven through the slotted drive plates by the output shaft to be slowly accelerated at the beginning of movement and decelerated at the end of movement.
The arrangement of the link members within the housing allows for 180° rotation of the output shaft while being compact to save space.
In a preferred embodiment, the slot in the second link member is substantially S-shaped thus shortening the length of the second link member to provide even more compactness.
IN THE DRAWINGS
FIG. 1 is a plan view of a transfer device according to the present invention.
FIG. 2. is a view taken along line 2--2 of FIG. 1;
FIG. 3 is a side view with a partial cutaway section of the finger drive according to the present invention;
FIG. 4 is a sectional view taken along line 4--4 of
FIG. 5 :s a perspective view of the finger drive with the ram at the bottom of its stroke;
FIG. 6 is a cutaway view of the finger drive when the ram is at the bottom of the press stroke;
FIG. 7 is a cutaway view of the finger drive when the ram is in midstroke;
FIG. 8 is a cutaway view of the finger drive when the ram is in the top of the press stroke;
FIG. 9 is a perspective view of the output crank arm;
FIG. 10 is a side view of the transfer drive;
FIG. 11 is a sectional view taken along line 11--11 of FIG. 10;
FIG. 12 is a perspective view of the transfer drive;
FIG. 13 is a cutaway view of the transfer drive when the ram is at the bottom of the press stroke;
FIG. 14 is a cutaway view of the transfer drive when the ram is at the top of the press stroke;
FIG. 15 is a diagram showing the timing of the finger drive;
FIG. 16 is a diagram showing the timing of the transfer drive;
FIG. 17 is a diagram showing the combination FIGS. 15 and 16;
FIG. 18 is a side view of a preferred form of the finger drive;
FIG. 19 is a view through line 19--19 of FIG. 18;
FIG. 20 is a view through line 20--20 of FIG. 18; and
FIG. 21 is a view through line 21--21 of FIG. 19.
DESCRIPTION
In the arrangement shown in FIGS. 1 and 2, the transfer device includes a base 10 upon which carriage 12 (shown schematically) is mounted. The carriage 12 is driven and reciprocates along an axis represented by arrow X by a transfer drive mechanism 76. The carriage 12 includes a plurality of work engaging fingers 14 driven along an axis represented by arrow Y by finger drive mechanism 41. FIGS. 1 and 2 show only half of the entire transfer device, it being understood that identical carriage and finger structure is located opposite that shown with only an identical finger drive. Thus, the one transfer drive 76 operates to shift the entire carriage through its transfer stroke while a finger drive 41 is required on each side of the transfer device to shift the work engaging fingers 14 toward and away from each other. The arrangement of the carriage and work engaging fingers shown and described so far is conventional and is of the type disclosed in, for example,
U.S. Pat. No. 4,032,018. In such devices, a drive mechanism is employed that is timed in relationship to the vertical movement of the press ram such that when the ram is traveling upwardly, the work engaging fingers 14 are shifted toward each other to grip workpieces (not shown) and the carriage 12 is thereafter shifted transverse to the finger movement to advance the workpieces to the next successive die station. Normally, the step of advancing the workpieces occurs while the press ram is traveling through top dead center. In the downstroke of the press ram, the work engaging fingers 12 are retracted to a position clearing the punches on the ram and while the punches are forming the workpieces, the carriage 12 is retracted to its starting position.
The present invention is primarily concerned with providing two separate drives both operable by the press ram. One drive is a finger drive 41 for driving the work engaging fingers and the other drive is a transfer drive 76 for reciprocating the carriage.
Referring particularly to FIGS. 3-8, the finger drive 41 is shown. The drive 41 is composed of a housing 42 which rests upon a base 43. The housing 42 comprises cam plates 64 on each side thereof. A first link 45 comprises parallel links 46, 48 and is fixedly connected by securing means S to the ram 44 at one end. The ram 44 is driven by means (not shown) in a reciprocal motion to reciprocate the first link 45 therewith. The parallel links 46, 48 are received in and guided by guide slots 64b (FIG. 5) inside of cam plates 64 for reciprocal movement. The ends of the parallel links 46, 48 opposite the ram have a rotatable follower 50 interconnecting therebetween by securing means 51. The follower 50 is received in an elongated slot 54 in a second link 52 for guided movement therealong. The second link 52 has a first and second set of cam followers 55, 56. The first set of cam followers 55 are received and travel within elongated cam slots 66 in the cam plates 64. The second set of cam followers 56 are positioned to engage along an outer cam surface 64a on the cam plates 64. The cam followers 55, 56 are rotatably mounted on a shaft, for example, 55a (FIG. 4) by any means such as a screw seen at 55b. The shaft 55a extends through a bifurcated end 53 of the second link 52 and has a bearing 57 for pivotal connection therewith. The bifurcated end 53 connects one end of a third link 58 by the shaft 55a. The opposite end of the third link 58 is connected to a crank shaft 63 coupled to the output shaft 62. A connector 60 and bearing 61 mount the end of the third link 58 for pivotal movement to the crankshaft 63. The output shaft 62 is rotatably mounted within a bearing housing 65 by roller bearings 65a.
An overload mechanism 35 (FIG. 2) is provided comprising an arm 36 with a roller 37 that engages a notch 38 in the upper portion of the parallel links 46, 48. Spring loaded balls 39, 40 hold the links 46, 48 to the ram 44 by engagement with openings 39b, 40b. The springs 39c, 40c bias the balls into engagement with the ram and are retained by a threaded member 39d, 40d which may be adjusted to change the spring force. Upon an overload condition, the force of the ram overcomes the spring force to move the balls 39, 40 out of engagement with the openings 39b, 40b. Thus, the ram 44 travels downward relative to links 46, 48. Arm 36 is then forced out of notch 38 and forced to the left as viewed in FIG. 2 to shut off the ram electrically; however, the ram continues to move approximately one-third of an inch by gravity to completely withdraw the fingers.
Referring now particularly to FIGS. 6-8 and 15, movement of the finger drive will now be described. When the ram is at the bottom of the press stroke, the finger drive is in the position shown in FIG. 5 where second link 52 is pivoted to the down position with the first cam followers 55 being positioned at the bottom of the cam slots 66 and second cam followers 56 being at the bottom of cam plates 64. As the ram 44 moves upward, the second cam followers 56 of the second link 52 follow along cam surfaces 64a as the second link 52 pivots about first cam followers 55. Output shaft 62 does not rotate thus there is a free travel of the ram 44 and the parallel links 46, 48. This free travel continues until the second cam followers 56 reach a point on the cam surfaces 64a where the first cam followers 55 begin movement of travel within cam slots 66. As the ram 44 continues its upward movement to the midstroke position as shown in FIG. 7, the parallel links 46, 48 are further raised. The follower 50 engages the end of the slot 54 in second link 52 thus raising the second link 52. First cam followers 55 move vertically along the cam slot 66. At the same time, second cam followers 55 engage along the cam surfaces 64a causing the second link 52 to pivot upwardly to the position shown in FIG. 7. As the second link 52 moves, the third link 58 moves therewith to rotate the crankshaft 63 and thus the output shaft 62 to a position 90° from the position in FIG. 6. Upon further upward movement of the ram, first cam followers 55 are moved further upwardly until they reach the upper end of the cam slot 66 as indicated in FIG. 8. At this point, the output shaft has rotated another 90° to reach the end of its full range of 180° movement starting from the position of FIG. 6 and ending in the position shown in FIG. 8. However, as the ram 44 freely travels to approach its upper press stroke, second cam followers 56 continue to follow along cam surfaces 64a thus further pivoting the second link 52 as the follower 50 moves along slot 54. As the ram 44 descends to begin the down stroke, the link movement merely reverses. Thus, there is free travel of the parallel links 46, 48 until first cam followers 55 begin movement in cam slots 66. When the first cam followers 55 again reach the bottom of cam slots 66 (FIG. 6), there is again free travel of the ram 44 and the parallel links 46, 48 until the ram reaches bottom dead center.
It can thus be seen that the output shaft 62 is limited to a 180° reciprocating motion and is only rotating when the first cam followers 55 confined within the cam slots 66 are moving. When the ram is at the midstroke position (FIG. 7), the output shaft 62 has rotated 90° from its prior position (FIG. 6). Thus, the output shaft 62 reaches this identical position when the ram is at midstroke regardless of the upward or downward travel of the ram. The fingers, which are connected to the output shaft, are positively controlled to be in on the up stroke of the ram and out on the down stroke. When the first cam followers 55 reach either end of the cam slots 66, the rotation of the output shaft 62 stops. The second cam followers, 56 on the outside of the cam plates 64 will continue to follow the contour of the cam surfaces 64a, again allowing for free travel of the ram 46 and the parallel links 46, 48. The free travel is dwell time and occurs during the press stroke both before and after the finger motion.
Referring now to FIG. 9, the output crank arm with a cam follower and a slotted drive plate is shown. This crank arm and drive plate mechanism is of a Scotch-yoke type drive and is used on both the finger drive 41 and the transfer drive 76. This can be seen in FIGS. 1 and 2 where crank arm 68 at finger drive 41 transmits movement to fingers 14 through finger actuator 16 through the drive plate 72. Likewise, crank arm 68 of transfer drive 76 transmits movement to carriage 12 through the drive plate 72 and transfer actuator 18. The crank arm 68 is secured to the output shaft 62 by any means, such as, for example bolt 68'. As the crank arm 68 begins to rotate, it slowly accelerates the drive plate 72 in the horizontal plane in the direction of the arrow B. The crank arm 68 swings from the left position down and to the right to the position shown in phantom. This motion is represented by arrow A. As the crank arm 68 moves, cam follower 70 reciprocates within slot 74 in the drive plate 72 and moves the drive plate 72 from the solid line position to the position shown in phantom. Thus, the drive plate 72 moves horizontally along the direction of arrow B in FIG. 9 and is accelerated and decelerated through the range of motion indicated by arrows A, B. The point of highest acceleration occurs when the crank arm 68 is at mid-position (not shown). The mid-position would be 90° in the direction of arrow A from either the solid line or phantom line position in FIG. 9. As the crank arm 68 passes the mid-position, it begins to decelerate, reaching minimum speed as it approaches the horizontal plane. The action of slow acceleration at the start, maximum speed at mid-position and slowing to a stop at 180° of rotation gives the desired controlled motion of the drive plate 72 and thus to both the carriage 12 and fingers 14 to allow for a more smooth transitional mechanical movement of the device thus reducing the load thereon and the likelihood of damage.
Referring now to FIGS. 10-14, the transfer drive will be described. This drive is very similar to the finger drive described previously in FIGS. 3-8, with the main differences being the slot and cam surface arrangement. As seen in FIG. 12, the transfer mechanism 76 consists of housing 78 which rests upon base 80. The ram 44 is mounted to the parallel links 84, 86 for reciprocal movement. Follower 88 is rotatably mounted in bearings 89 (FIG. 11) connected by securing means 88' at the free end of the parallel links 84, 86 and is captured within slot 92 of second link 90. The second link 90 has a set of cam followers 98 captured within cam slots 96 in the housing 78. The cam followers 98 are secured to a shaft 98a by means such as a screw 99b. Shaft 98a is rotatably mounted within bearing 99a and extends through a bifurcated end 91 of second link 90. Spring friction disks or Belleville springs 99 are disposed between the bifucated end 91 of the second link 90 and the parallel links 84, 86 to act as a brake to prevent the followers 98 from moving in the cam slots 96 during the dwell portion of the ram. Third link 100 is connected at one end to the bifurcated end 91 and is connected at the other end to crankshaft 102 for driving the output shaft 104. The output shaft 104 is rotatably mounted in bearing housing 106 by bearings 106a (FIG. 11).
A preferred form of the finger drive 41 is seen in FIGS. 18-20 where identical numerals will be used for identical parts. In this embodiment, the parallel links 46, 48 are guided within the cam plates 64 by guide rollers 110 rotatably mounted to extend inwardly of the cam plate 64. The guide rollers 110 engage along an outer surface of the parallel links 46, 48 for guided reciprocal movement. The guide rollers 110 are secured to the cam plates 64 by any means 111 such as screws and are removable to allow assembly and disassembly. The second link 112 has a substantially S-shaped slot 113 that receives the follower 50 interconnecting the ends of the parallel links 46, 48. The second link has first and second cam followers 114, 116. The second cam followers 116 are rotatably mounted at one end of the second link 112 and engage along an outer cam surface 64a of the cam plates 64. The cam followers 116 are connected to the second link 112 at a bifurcated end 117. The cam plates 64 have an arcuate slot 115 to receive the cam followers 116 when the second link 112 is in the lowermost position. The other end of the second link has cam followers 114 received within cam slots 66 in the cam plates 64. The other end of the second link 112 is bifurcated at 117' for connection with third link 58 similar to the embodiment of FIG. 3. This construction of the finger drive allows for a shorter second link 112 to be used while obtaining the same length of travel of the parallel links 46, 48 as before. The overload mechanism 35 has spring loaded shouldered plungers 118 having the same function as the spring loaded balls of the embodiment of FIG. 3.
It is to be understood that a preferred embodiment of the transfer drive also utilizes the guide rollers 110 and a second link 112 having a substantially S-shaped slot for ease of assembly and disassembly and for conserving space.
A preferred embodiment of the drive plate 119 is shown in FIGS. 19-21 with the finger drive 41 to drive the fingers in an in/out motion. However, it is understood that the same drive plate is used on the transfer drive 76 to advance the carriage. The drive plate 119 is driven through a Scotch-yoke where the cam follower 70 of the crank arm 68 is received in cam slot 120 in a lower extension 121 of the drive plate 119. The upper portion 122 of the drive plate is substantially rectangular and is supported on the side of the housing by a grooved suspension plate 123. The suspension plate 123 is secured to the housing by any means such as screws 124 that connect the suspension plate 123 to a spacer 125. The drive plate 119 has means 126 for connecting to either of the fingers or the carriage, depending on which drive the drive plate 119 is used with. It can be seen from FIG. 21, as the crank shaft 68 rotates through a circular motion M by the output shaft 62, cam follower 70 transmits reciprocal motion to the drive plate 119 by the engagement with the cam slot 120 therein. Thus, it can be understood that the drive plate 119 transmits reciprocal motion to either of the fingers or the carriage.
FIG. 10 illustrates the motion of the drive as the ram moves from its bottom position shown in solid lines to the top position shown in phantom. FIGS. 12 and 13 illustrate the transfer drive when the ram is in the bottom position in which the followers 98 are positioned at the bottom of the cam slots 96. FIG. 14 illustrates the position in which the ram is in the top position where followers 98 are at the top of the cam slots 96.
As most seen clearly in FIG. 10, similar to the finger drive the transfer drive rotates the output shaft 104 only when cam followers 98 move within cam slots 96. Thus, as the ram moves upwardly from the solid line position in FIG. 10, the second link 90 is raised from its lowermost position by engagement of the follower member 88 in slot 92. The second link 90 rotates about cam followers 98 relative to the third link 100. This free travel movement of the ram 44 does not result in any driving engagement being transmitted to output shaft 104. Upon continued upward movement of the ram 82, the second link 90 is further moved upwardly to raise cam followers 98 along cam slots 96 from the lowermost position to the uppermost position. This movement of the cam followers 98 transmits movement to the third link 100 from the position shown in phantom in FIG. 10 to the position as shown in FIG. 12 to drive the output shaft about the desired angle of rotation. Then, as the ram begins to descend, there is again free travel of the ram 44 and the parallel links 84, 86 until cam followers 98 begin movement in cam slots 96.
It can be understood that the free travel movement in the finger drive 41 occurs at a different time than the free travel movement of the transfer drive 76. The timing of the finger drive 41 and the transfer drive 76 can be seen in the diagrams of FIGS. 15-17. In FIG. 15, A represents the position of the press ram at top dead center and B represents the beginning of the finger movement outward. At C, the fingers have moved completely outward so that the movement between B and C represents movement of the second cam followers 56 in the cam slots 66. Bottom dead center of the press ram is represented at D. At this position the links are in the position shown in FIG. 6 with the second cam followers 56 being located at the bottom of the cam slots 66. The movement from D to E represents movement of the links from the bottom dead center position as seen in FIG. 6 to a point (not shown) where second cam followers 56 begin movement of travel within cam slots 66. The movement of the links from the position of FIG. 6 to the position of FIG. 8 is represented by E and F, with F representing the point where the fingers are moved completely inward. The movement from point F back to A represents free travel of the ram to top dead center.
FIG. 16 represents timing of the transfer drive where movement from A to C represents free travel of the ram from the upper most position seen in phantom of FIG. 10 to a position (not shown) to where the cam followers 98 start to move within cam slots 96. The movement of the cam followers 98 from the upper most position to a lower most position within the cam slots 96 is represented by points C and D, respectively resulting in transfer return movement. As the ram starts its upstroke, there is a free travel of the links to a point where the cam followers 98 again start movement in cam slots 96 and this free travel movement is represented between points D and F. The movement from F to A again represents movement of the cam followers 98 from the bottom of the cam slots 96 to the top thereof resulting in forward transfer movement.
The combination of finger drive movement and transfer movement is represented by the timing diagram of FIG. 17. It can be seen that during finger motion, the transfer drive is in the dwell mode.
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A transfer device for indexing workpieces through successive stations of a die in a stamping press is provided wherein the carriage and work engaging fingers are driven through separate drives actuated by the press ram. Each drive has an output shaft for operating the carriage and work engaging fingers, respectively. Each drive is compact and saves space by utilizing a plurality of links to drive the output shaft through 180° of rotation so that desired accelertion and decelaration can be achieved. Each drive is a stand-alone mechanism adapted for use with existing transfer devices.
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FIELD OF THE INVENTION
[0001] The invention is related to semiconductor devices, and more particularly, to field effect transistors (FETs) showing an improved performance by incorporating scalable stressed channels.
BACKGROUND OF THE INVENTION
[0002] The ability to scale CMOS devices to smaller dimensions has allowed integrated circuits to experience continuous performance enhancements. Moreover, in spite of economic considerations, constraints on device designs and materials are hampering further improvements in scaling the devices. Since constraints in scaling are imposing fast approaching limits beyond which technical and economic constraints make additional scaling unappealing, new techniques have been developed to continuously increase the device performance.
[0003] One alternative which has gained popularity is to impose certain mechanical stresses within a semiconductor device substrate which can be advantageously used to modulate the device performance. For example, in silicon, hole mobility is enhanced when the silicon film is under compressive stress, while the electron mobility is enhanced when the silicon film is under tensile stress. Therefore, compressive and/or tensile stresses can be advantageously created in the channel regions of a p-FET and/or an n-FET in order to enhance the performance of such devices. However, the same stress component whether compressive or tensile, discriminatively affects the performance of the p-FET and the n-FET devices. Alternatively, compressive stress in the silicon, while it enhances the performance of the p-FET, it adversely affects the performance of the n-FET, while a tensile stress enhances the performance of the n-FET while adversely impacting the performance of the p-FET. Therefore, p-FET and n-FET require different types of stresses for performance enhancement, which imposes a challenge when concurrently fabricating high performance p-FET and n-FET devices, due to the difficulty in simultaneously applying compressive stress to the p-FET and tensile stress to the n-FET.
[0004] One approach for creating desired compressive and tensile stresses in the channel regions of p-FET and n-FET devices is to overlay the p-FET and the n-FET devices with separate compressive and tensile stressed dielectric films so that the tensile and compressive stresses can be respectively applied to the n-FET and p-FET devices.
[0005] Another problem of significance is the trend towards devices having smaller and smaller dimensions. Researchers have investigated the impact of technology scaling in reducing the effectiveness of virtually all known stress enhancement techniques. Channel stress from stressed liners is reduced with a tighter PC pitch, shorter polysilicon stacks and embedded SiGe (and embedded carbon), wherein the effectiveness is reduced with smaller RX-past-PC dimensions, for example. Hence, when migrating from one technology node to the next, one must find ways to overcome the degradation associated with scaling and find additional options to improve the technology performance further. Traditionally, this has been achieved by brute force, i.e., by way of higher stress liners, higher germanium content in eSiGe, and the like, or by significantly modifying the device materials/structure, such as embedded SiC.
[0006] Present day stress devices are currently manufactured with a stress inducing liner that is advantageously formed atop the gate region, the exposed surface of the substrate adjacent to the gate region and silicide contacts. An example of such stress devices is found, e.g., in U.S. Pat. No. 7,002,209 to Xiangdon Chen et al., of common assignee. The patent describes methods of forming a liner such that it contacts the sidewalls of the gate conductor. When thin sidewall spacers are used, the stress inducing liner is positioned on the thin sidewall spacer such that the thin sidewall spacer separates the stress inducing liner from the gate region. The stress inducing liner is deposited under conditions that create a compressive or a tensile stress. The method described in the aforementioned patent, however, is limited to the use of a single stress liner.
[0007] Another problem arising by the ever shrinking ground rules governing high performance technologies is caused by the loss of stress when reducing the pitch of the gate electrode conductor. This phenomenon has been described in the current literature, and more particularly in the paper “1-D and 2-D effects in uniaxially-strained dual etch stop layer stressor integrations” by Paul Grudowski et al., published in the Digest of Technical Papers of the 2006 Symposium on VLSI Technology. Therein are described a detailed electrical and simulation characterization of 2-D boundary effects and 1-D poly pitch response of highly stressed dual etch stop layer integrations, and how these effects impact achievable transistor performance gains and improved circuit designs. A contact etch stop layer used as a stressor has demonstrated significant performance improvements, particularly when employed in a dual integration. Still, the problem caused by continuously scaling down the devices remains.
[0008] A further problem imposed by traditional scaling methods is caused by the loss of stress when reducing the height of the gate electrode conductor. This phenomenon has also been described in the current literature, and more particularly in a paper “MOSFET Current Drive Optimization Using Silicon Nitride Capping Layer for 65-nm Technology Node” by S. Pidin et al., published in the Digest of Technical Papers of the 2004 Symposium on VLSI Technology. Therein is described a simulation characterization of device channel stress response to gate electrode height for highly stressed etch stop layers. Thus, a tradeoff is established between the traditional scaling benefits of gate height reduction, namely parasitic capacitance reduction due to a reduced gate sidewall area, and the stress imparted to the channel from a stressed liner.
[0009] In order to better appreciate the advantages, aspects and benefits of the present invention, prior art stressed complementary FET devices will now be described in order to distinguish the device structure of the present invention when it is compared to conventional prior art devices.
[0010] Referring to FIG. 1 a , there is shown a pair of complementary FET devices (i.e., n-FET and p-FET) illustrating a first stress liner atop the transistor already patterned to induce the desired mobility gain. The first stress liner can be either tensile or compressive and thickness ranges from 40 nm-100 nm, with 50 nm being more typical. The stress liner in FIG. 1 a is patterned using standard lithography and etching techniques where the stress liner is left on top of the devices that result in a mechanical strain favorable for increasing the mobility of the carriers. Tensile stress liners impart a stress that increases the electron mobility, while compressive stress liners impart a stress that increases the hole mobility. The stress liner is preferably any dielectric commonly used in semiconductor processing (SiN, SiO 2 , SiCOH, HfO 2 , SiCN, ZrO 2 ), although SiN is preferably used.
[0011] Referring to FIG. 1 b , the same pair of complementary FET devices are depicted having a second stress liner already patterned. The second stress liner should provide an opposing stress from that provided by the first stress liner and be removed from transistors that are covered by the first stress liner. For example, if the first stress liner is tensile, then the second stress liner should be compressive. The second stress liner should preferably have a thickness ranging from 40 nm-100 nm, with 50 nm being more typical. The second stress liner can be any of the standard dielectrics used in semiconductor processing (SiN, SiO 2 , SiCOH, HfO 2 , ZrO 2 , SiCN), although SiN is more commonly used.
[0012] Still referring to FIG. 1 b , a thin oxide layer is deposited after patterning the first liner but before depositing the second liner in order to achieve etch selectivity if the second stress liner is made of a similar material as the first stress liner.
[0013] Next, referring to FIG. 2 , another dielectric layer is deposited atop the silicon wafer. The dielectric is typically a low temperature SiO 2 deposition with thickness ranging from 150 nm-250 nm, with 210 nm being more typical.
[0014] Referring to FIG. 3 , the same semiconductor structure is illustrated after applying Chemical Mechanical Polish (CMP), resulting in the oxide being removed by this standard polishing step commonly used in semiconductor processing. The oxide is preferably removed until the top of the gate conductor electrodes are exposed, leaving no oxide. The final surface needs to be flat with no surface topography to have the surface directly above the target FET totally planarized.
[0015] The devices shown thus far suffer from a distinct degradation when the pitch between the complementary devices shrinks as the technology migrates from one node to the next. During the pitch reduction, the length of the stress nitride-silicon film interface is reduced, which in effect, reduces the stress coupling from the liner to the silicon film and MOSFET channel. In addition, the resulting stresses induced devices shown thus far remain susceptible to degradation from gate height reduction. This is because the stress in the channel is created by edge forces induced at the stressed-liner/sidewall spacer/silicon film intersection, the strength of which depend upon the poly height, as well as stressed-liner thickness, poly pitch, and the like.
[0016] Accordingly, there is a need in industry for a process of forming dual stress liners in which enhanced n-FET stress from a compressive cap can be achieved by reducing the polysilicon height without degradation during PC pitch scaling.
OBJECTS AND SUMMARY OF INVENTION
[0017] Accordingly, it is an object of the present invention to provide enhanced FET devices displaying an improved performance by incorporating a scalable stressed channel.
[0018] It is another object of the invention to improve the performance by providing a dual-stress liner atop the gates of complementary FET devices.
[0019] It is a further object to induce the n-FET stress from a compressive cap which does not degrade with PC pitch scaling, and where enhancement from the compressive cap increases with gate height reduction.
[0020] It is still a further object to provide a compressive liner having significantly higher stress than corresponding tensile counterparts.
[0021] It is a yet another object to make the inventive structure compatible with replacement gates while ensuring a low implementation cost.
[0022] In accordance of one aspect of the invention, the performance of a CMOS FET device improves significantly by taking advantage of known dual-stress-liner effects, making use of compressive nitride in an appropriate geometric configuration to induce tensile stress in the n-FET channel, and similarly employ a tensile nitride for compression in the p-FET.
[0023] Of particular importance to this approach resides in its scalability. The stress enhancement is designed to be insensitive to PC pitch, a distinct advantage, and to increase by reducing the height of the gate stack. In addition, since the n-FET can leverage the higher stress values obtainable by compressive liners (i.e., >3 GPa, compared to <1.5 GPa for tensile), considerable benefits with this approach are anticipated.
[0024] The present invention provides a semiconductor device that includes: at least one n-channel field effect transistor (n-FET) and at least one p-channel field effect transistor (p-FET) that are spaced apart from each other on a substrate; and a first dielectric stressor layer overlaying the gate of at least one n-FET and a second dielectric stressor layer overlaying the gate of at least one p-FET, wherein the first dielectric stressor layer is compressively stressed and the second dielectric stressor layer is tensilely stressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description of the invention taken in conjunction with the accompanying figures, in which:
[0026] FIG. 1 a is a schematic diagram illustrating prior art complementary FET devices on a substrate wherein a first liner has been deposited in selected areas (up to middle-of-line (MOL) dielectric deposition);
[0027] FIG. 1 b is a schematic diagram illustrating the prior art complementary pair of FET devices in which a second liner has been deposited in selected areas (up to MOL dielectric deposition);
[0028] FIG. 2 is schematic diagram illustrating the two prior art complementary FET devices of FIG. 1 b wherein a blanket oxide layer has been deposited atop the two devices;
[0029] FIG. 3 illustrates a schematic diagram in which the nitride layer on top of the polysilicon has been removed, preferably, by chemical mechanical polishing, in order to planarize the surface above the target FET; and
[0030] FIG. 4 illustrates improved devices wherein a compressive nitride cap has been deposited on top of the n-FET gate, and a compressive nitride cap or tensile nitride cap or a combination of a compressive layer that includes implant relaxation has been deposited on top of the p-FET gate, in accordance with a preferred embodiment of the present invention, wherein edge forces are induced at the two ends of the cap.
[0031] FIG. 5 illustrates the improved devices shown in FIG. 4 , wherein the p-FET device is capped by a compressive nitride cap, in accordance with another embodiment of the present invention.
[0032] FIG. 6 illustrates the improved devices shown in FIG. 4 , wherein the stress cap technique is provided to the n-FET, leaving the p-FET device fully uncapped, according to still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] In the following description, numerous specific details are set forth, such as particular structures, components, materials, and dimensions, in order to provide a thorough understanding of the present invention. However, it will be readily appreciated by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the invention.
[0034] It will be understood that when an element as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will also be understood that when an element is referred to being “connected” or “coupled” to another element, it is directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
[0035] FIG. 4 shows a cross-sectional view of a CMOS device according to one embodiment of the present invention.
[0036] The present invention provides an improved CMOS device that includes at least one n-FET and at least one p-FET with a dielectric stressor, preferably a nitride layer, directly connected to the gate of each of the FET devices, hereinafter referred to as a “cap”. The dielectric stressor caps provide the desired stresses on the n-FET and the p-FET devices.
[0037] More specifically, the CMOS device comprises an n-FET that is located over an n-FET active region 2 and a p-FET that is positioned over a p-FET active region 4 . The n-FET active region 2 and p-FET active region 4 are located in the same semiconductor substrate (not shown), separated from each other by isolation region 11 . The n-FET active region 2 contains n-type source and drain doping regions (not shown) with source and drain silicide contacts 21 and 23 . Similarly, the p-FET active region 4 contains n-type source and drain doping regions (not shown) with source and drain silicide contacts 41 and 43 .
[0038] Separate gate structures, one of which is formed by: (1) a first gate conductor 24 , (2) a gate metal silicide 25 , and (3) and at least one spacer 27 , and the other that includes: (1) a second gate conductor 44 , (2) a second gate metal silicide 45 , and (3) at least one spacer 47 , which are formed over n-FET active region 2 and p-FET active region 4 , respectively. Gate dielectrics 22 and 42 respectively isolate the n-FET active region 2 and the p-FET active region 4 from the first and second gate conductors 24 and 44 .
[0039] The respective gates of the n-FET and p-FET are capped by stress layers, preferably by a compressively stressed nitride cap on top of the n-FET, and either by a compressively nitride cap or a tensilely nitride cap or a compressively stressed nitride cap that includes implant relaxation.
[0040] The dielectric stressor cap layers 50 and 60 preferably includes any suitable dielectric material whose stress profiles can be modulated or adjusted. Preferably, but not necessarily, the continuous dielectric stressor layer 50 includes SiN.
[0041] The above-described stressor layers 50 and 60 is advantageously formed by a selective UV-treatment process, which has been found by the inventors of the present invention to be particularly effective in converting compressive stress of a dielectric film into tensile stress.
[0042] Exemplary processing steps that can be used for forming the dielectric stressor cap 50 and 60 in the CMOS device structure illustrated by FIG. 4 will now be described in greater detail. Note that in the drawing, which is not drawn to scale, like and/or corresponding elements are referred to by like reference numerals. It is further noted that in the drawings only one n-FET and one p-FET are shown. Although illustration is made to such an embodiment, the present invention is not limited to the formation of any specific number of n-FETs and/or p-FET devices, and can easily include an array formation of such devices.
[0043] Still referring to FIG. 4 , the semiconductor structure after depositing and patterning a stress liner layer (layer C in the drawing) is shown where the pattered layer is centered over the gate electrode. The edges of stress liner C in FIG. 4 impart a mechanical stress on the channel that can increase the mobility of the carriers.
[0044] The stress liner can be any dielectric used in semiconductor processing (SiN, SiO 2 , SiCOH, HfO 2 , ZrO 2 , SiCN), although SiN is preferred. The thickness of the stress liner ranges from 10 nm to 800 nm, but 40 nm is preferred. The stress liner create either compressive or tensile stress; however, compressive stress is preferred since higher magnitudes of stress can be achieved for compressive SiN stress liners compared to tensile stress liners. Typical compressive SiN stress liners preferably have a stress value of 3 GPa or greater, while tensile SiN stress liners have a stress value of 1.5 GPa. The larger compressive stress liner has been found to impart more stress, translating to a higher mobility gain.
[0045] The compressively stressed dielectric layer, as mentioned previously, is made, e.g., of SiN, which can be readily formed by plasma-enhanced chemical vapor deposition (PECVD) process or a high-density plasma (HDP) process that is carried out at a temperature ranging from about 300° C. to about 450° C., a pressure ranging from about 0.5 torr to about 6 torr, and a plasma power level ranging from about 100 W to about 1500 W, using processing gases that include trimethylsilane, NH 3 , and N 2 .
[0046] Still referring to FIG. 4 , a compressive stress liner (liner C) results in providing tensile mechanical stress in the transistor channel; therefore, it is best to pattern the stress liner C over the n-FET transistor to produce the desired gains in performance.
[0047] Referring back to previously described FIG. 1 b , a tensile stress liner on the n-FET was illustrated and a compressive stress liner on the p-FET. The tensile (compressive) nitride on the source drain regions of the n-FET (p-FET) induces a tensile (compressive) stress in the channel region, which in turn improves the electron (hole) mobility within the channel. The magnitude of the stress induced in the silicon depends on (among other factors) the lateral extent of the nitride away from the silicon channel. During scaling, due to the ground rule shrink, adjacent gates become closer to each other. This results in the lateral extent of the nitride becoming smaller and so the stress induced in the channel also reduces.
[0048] Still referring to FIG. 1 b , while the nitride film on top of the source and drain regions induced tensile stress in the channel, the tensile nitride on top of the gate, in contrast, induced a compressive stress in the channel reducing the stress caused by the nitride film at the bottom. Further, as the height of the gate is reduced, the top nitride comes closer to the channel and the compressive stress induced by this nitride film increases. Thus, reducing the gate height also reduces the stress induced by the whole tensile nitride film (for a given stress in the nitride film).
[0049] Now referring to FIG. 4 , the tensile nitride is removed only from the top of the n-FET and is replaced with a compressive nitride layer. The compressive liner is then etched, creating an edge force at each of the compressive liner sidewalls, as indicated in the drawing. The compressive nitride on top of the gate induces a tensile stress in the silicon channel (opposite of what the tensile nitride film on top of the gate earlier induced). This adds to the tensile stress being induced by the tensile nitride over the source-drain regions, increasing the stress in the channel. Bringing the compressive nitride on top of the gate closer to the channel, (i.e., by reducing the gate height) increases the tensile stress induced in the channel. Finally, it is observed that the lateral extent (or the length) of the compressive nitride does not need to scale as the pitch (distance between two adjacent devices) is reduced. The present inventive method circumvents the problem related to the reduction of the improvement when the pitch is scaled downward. Finally, the use of a compressive nitride film is of particular benefit to n-FET devices having compressive nitride films of approximately 3.5 GPa. This has been demonstrated experimentally. In contrast, the highest stress that has been obtained for tensile films is of the order of 1.5 GPa.
[0050] Although the above invention has been described for n-FET devices, the conclusions are equally applicable to p-FETs, but the stress of the various stress films is reversed. Thus, the stress film over the source and drain would optimally be compressive in nature, while the stress film over the gate is tensile in nature.
[0051] For optimal performance, one would simultaneously form tensile stressed liner caps on p-FETs and compressive stressed liner caps on n-FETs. However, performance advantage can be obtained with at lower cost or complexity by selectively capping either the n-FETs or the p-FETs, and performing an implant relaxation into the stressed cap covering the sub-optimally configured device (i.e., p-FET with compressive cap, or n-FET with tensile cap). Alternatively, one can employ silicon substrates in which one FET type is relatively insensitive to stress, and employ a single stressed liner cap to improve the performance of the other. For example, (001) silicon wafers, with gates oriented along <100> axes result in p-FETs which are rather insensitive to stress. In this case, a compressive cap on the n-FET and p-FET would be preferred and most economical implementation of this structure, as illustrated in FIG. 5 .
[0052] One advantage of patterning a compressive liner C, illustrated in FIG. 4 , is the increase in mechanical stress that arises from the vertical edge force of the patterned film. The stress from the edge force adds to the mechanical stress in the channel already present from stress liner B. In addition, current state of the art compressive liners achieve much higher levels of stress compared to tensile liners (3.5 GPa for compressive versus 1.5 GPa for tensile). Using the compressive liner on the n-FET transistor is not possible in the conventional dual stress liner approach illustrated in FIGS. 1 a - 1 b (prior art) as it would result in an undesirable compressive stress in the channel of the n-FET (since the compressive stress degrades n-FET mobility but enhances the hole mobility). However, creating a planarized flat surface using CMP ( FIG. 3 ) with a patterned compressive liner on the flat surface ( FIG. 4 ) gives rise to an edge force that imparts tensile stress in the channel of the MOSFET, and which has shown to be very beneficial for n-FET device improvement. Therefore this structure enables the use of higher magnitude compressive stress films on n-FET transistors to help maximize performance.
[0053] An additional advantage of the structure illustrated in FIG. 4 is that it reduces the sensitivity to spacing between gate electrodes. One of the problems with using the known prior art of dual stress liners as illustrated in FIGS. 1 a - 1 b is the reduction of stress as the spacing between the gate electrodes diminishes.
[0054] Practitioners of the art will recognize that under certain constraints, the drive current can decrease as the spacing between the gate electrodes shrinks. This degradation arises because there is less volume of the stress liner material for applying stress in the channel of the MOSFET. Since the length (or volume) of the liner C depends only weakly on the distance between the 2 gates—i.e., the length is pitch insensitive—then the stress it applies is independent of the technology pitch.
[0055] Finally, the present structure shows that the stress increases as the thickness of the gate electrode is reduced. Reducing the thickness in advanced CMOS technology is desirable and can only enhance the stress gained from the patterned stress liner C.
[0056] Referring to FIG. 6 , another embodiment of the invention shows the p-FET device without any cap atop the gate of the device. This is valid as long as the other (i.e., complementary) device is provided with an appropriate stressed cap on its corresponding gate. The benefit obtained is comparable to the compressive+implant solution, but it clearly saves the cost of the relaxation implant and added lithography.
[0057] While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the present description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.
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A CMOS FET device having an enhanced performance is described by taking advantage of known dual-stress-liner effects and by making use of compressive nitride in an appropriate geometric configuration to induce compressive stress in the n-FET channel, and a tensile stress in the p-FET. The stress enhancement is designed to be insensitive to PC pitch, and to increase by reducing the height of the polysilicon stack, such that scalability contributes to the stated performance improvement. The n-FET leverages higher stress values that are obtainable in the compressive liners to be greater than 3 GPa, compared to less than 1.5 GPa for tensile liners.
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BACKGROUND OF THE INVENTION
The invention relates to a heat engine for a motor vehicle.
The invention relates more particularly to a heat engine for a motor vehicle, of the type which comprises at least one cylinder block which comprises a first internal circuit for the circulation of a cooling liquid, of the type in which the first internal circuit comprises an internal supply duct an inlet orifice of which opens into a reception chamber or “volute”, that is substantially cylindrical, of a rotor belonging to a water pump of the engine, which is formed in the block, said chamber comprising in an intermediate portion a supply orifice the level of which is arranged above the level of the inlet orifice of the internal supply duct of the first internal circuit.
Many examples of heat engines of this type are known.
A known disadvantage of this type of engine is associated with the particular arrangement of the orifice for supplying the reception chamber or “volute” of the water pump with respect to the inlet orifice of the first circuit.
Specifically, in this configuration, when it is desired to fill the cooling circuit by gravity, an air pocket forms in the upper portion of the reception chamber or volute which is situated above the level of the orifice for supplying said reception chamber.
This residual air pocket prevents the priming of the water pump when the engine is started, which may result in damage to the water pump or a lack of the circulation of the cooling liquid within the cooling circuit of the vehicle.
It is therefore necessary to fill the cooling circuit under pressure in order to achieve a correct priming of the water pump.
SUMMARY OF THE INVENTION
To remedy this disadvantage, the invention proposes an engine of the type described above comprising means for draining the upper portion of the reception chamber or volute of the water pump.
For this purpose, the invention proposes a heat engine of the type described above, characterized in that it comprises an additional venting duct which connects an upper portion of the reception chamber or volute of the water pump to an element of the cooling circuit of the engine in order to allow the reception chamber to be completely filled by gravity when the first internal circuit is filled.
According to other features of the invention:
the determined element is a chamber which is formed in the cylinder block and which forms part of the first internal circuit, the additional duct is a calibrated duct formed in the cylinder block, the cylinder block is capped by a cylinder head, a second internal circuit for the circulation of a cooling liquid communicating with the first internal circuit via at least one drill hole formed in a cylinder head gasket, and the determined element is said drill hole in the cylinder head gasket, the additional duct is formed in the cylinder block and opens into the drill hole in the cylinder head gasket, the additional duct is cast in one piece with the cylinder block and is calibrated by the cylinder head gasket, the additional duct is a calibrated drill hole made in the cylinder block, the determined element is an external duct for supplying an engine member, notably an oil cooler, with cooling liquid, said external duct being placed beside the block, the additional duct is formed in the cylinder block and opens into the external duct via a hole.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the invention will appear on reading the following detailed description for the understanding of which reference will be made to the appended drawings in which:
FIG. 1 is a schematic view in perspective of an engine block according to a prior art;
FIG. 2 is a detailed schematic view in perspective of an engine block according to a first embodiment of the invention;
FIG. 3 is a detailed schematic view in perspective of an engine block according to a second embodiment of the invention;
FIG. 4 is a schematic view in section of the engine according to the second embodiment of the invention;
FIG. 5 is a schematic view in perspective of an engine block according to a third embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, identical reference numbers designate parts that are identical or have similar functions.
FIG. 1 depicts a motor vehicle engine 10 comprising a block 11 , commonly called a “cylinder block”, capped by a cylinder head 13 .
In a known manner, the cylinder block 11 comprises a first internal circuit 12 for the circulation of a cooling liquid which is designed for example to cool the engine block 11 by allowing circulation of a cooling liquid around the cylinders 15 of the engine.
In a known manner, the first internal circuit 12 comprises an internal supply duct 14 , an inlet orifice 16 of which opens into a reception chamber 18 , also called a “volute”, which is arranged in the block 11 and which is designed to receive a rotor (not shown) of a water pump fitted to the engine 10 .
In a known manner, the reception chamber 18 is formed in the cylinder block 11 and it comprises, in an intermediate portion 20 , arranged for example substantially level with the axis “A” of rotation of the rotor (not shown), a supply orifice 22 designed to allow the water pump of the engine to be supplied with cooling liquid.
As can be seen in FIG. 1 , in a known manner, the level N 1 of the orifice 22 for supplying the reception chamber 18 is arranged above the level N 2 of the inlet orifice 16 of the internal supply duct 14 of the first internal circuit 12 .
A known disadvantage of heat engines 10 made in this design is associated precisely with the difference between the level N 1 of the supply orifice 22 and the level N 2 of the inlet orifice 16 of the first internal circuit 12 .
Specifically, when it is desired to fill such a cooling circuit by gravity, because of the difference between the levels N 1 and N 2 , an air pocket forms in the upper portion 24 of the reception chamber 18 which is arranged above the supply orifice 22 of the reception chamber 18 .
This residual air pocket prevents the priming of the water pump when the engine is started, which may result in damage to the water pump or a lack of circulation of the cooling liquid within the cooling circuit of the vehicle.
It is therefore necessary to fill the cooling circuit under pressure in order to achieve a correct priming of the water pump, and a draining of the circuit at another point, which complicates the operation to fill the circuit.
To remedy this disadvantage, the invention proposes an engine 10 of the type described above, comprising means for draining the upper portion 24 of the reception chamber 18 of the water pump.
For this purpose, the invention proposes a heat engine 10 of the type described above, characterized in that it comprises an additional venting duct 26 which connects the upper portion 24 of the reception chamber 18 of the water pump to an element of the cooling circuit of the engine in order to allow the reception chamber 18 to be completely filled by gravity when the first internal circuit 12 is filled.
According to a first embodiment of the invention, which has been shown in FIG. 2 , the determined element to which the additional duct 26 is connected is a chamber 28 which is formed in the cylinder block 11 and which forms part of the first internal circuit 12 . This chamber 28 is for example a peripheral chamber surrounding a cylinder 15 of the cylinder block 11 .
In this embodiment, the additional duct 26 is preferably a duct 26 formed in the cylinder block 11 , and this duct 26 is calibrated so as to allow a leakage of cooling liquid from the reception chamber 18 of the water pump which is sufficient to allow the air pocket to be dispelled, and which is nevertheless small enough not to hamper the operation of the water pump.
According to a second embodiment of the invention which has been shown in the detailed views of FIG. 3 and of FIG. 4 , the invention advantageously takes advantage of the presence of a cylinder head 13 of the engine which caps the cylinder block 11 .
A cylinder head gasket 32 is arranged between an upper face 34 of the cylinder block 11 and a lower face 36 of the cylinder head 13 .
As illustrated in FIG. 4 , the cylinder head gasket 32 comprises at least one drill hole 38 which allows the first internal circuit 12 of the block 11 to communicate with a second internal circuit 40 of the cylinder head 30 .
In this configuration, the determined element to which the additional venting duct 26 is connected is the drill hole 38 in the cylinder head gasket 32 .
For example, the additional venting duct 26 is formed in the cylinder block 11 and it opens into the upper face 34 of the block 11 via an orifice 30 which is designed to substantially coincide with the drill hole 38 of the cylinder head gasket 32 .
In a manner similar to the preceding embodiment, as illustrated in FIG. 4 , the additional duct 26 may advantageously be calibrated by the cylinder head gasket 32 itself, the latter being able to obstruct to a greater or lesser degree the end of the additional duct 26 formed by the orifice 30 so as to regulate the flow rate of cooling liquid circulating in said additional duct 26 , in order to allow sufficient venting of the air pocket contained in the reception chamber 18 without however hampering the operation of the water pump.
Advantageously, it will be understood that in this embodiment, the additional duct 26 will preferably be cast in one piece with the cylinder block 11 , which makes it possible to achieve its calibration only via the cylinder head gasket 32 without requiring particular machining of said duct 26 .
It will also be understood that, as a variant, the additional duct 26 may, in a manner similar to the first embodiment of the invention, be a calibrated duct which opens fully into the drill hole 38 of the cylinder head gasket, the calibration of the additional duct 26 then resulting from a machining of said duct 26 , and notably of its end orifice 30 , in the cylinder block 11 .
Finally, according to a third embodiment of the invention which has been shown in FIG. 5 , the determined element to which the additional venting duct 26 is connected may be an external duct 42 for supplying an engine member, for example an oil cooler 43 , with cooling liquid, said external supply duct 42 being placed beside the cylinder block 11 .
In this configuration, at least a communication portion 44 of the external duct 42 comprises a wall independent of the cylinder block and a wall forming part of the cylinder block 11 , which communicates with the additional duct 26 via a hole 50 . This design advantageously makes it possible to dispense with a connection of the additional duct 26 with the communication portion 44 of the external duct 42 , while ensuring a perfect seal.
The external duct 42 is then delimited in its communication portion 44 by its independent wall and by its wall formed on the outside of the cylinder block 11 .
The invention therefore advantageously makes it possible to achieve venting of the reception chamber 18 of a water pump belonging to a motor vehicle engine 10 , which makes it possible to fill the cooling circuit by gravity without needing to pressurize said cooling circuit.
The maintenance of such a motor vehicle engine 10 is therefore made much easier.
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A thermal engine for an automotive vehicle, including at least one cylinder block including a first inner circuit for circulating a cooling liquid, of the type in which the first inner circuit includes an outer supply duct including an inlet opening into a reception chamber for a rotor of the engine water pump formed in the block. The chamber includes in its intermediate portion a supply opening having a level located above the level of the inlet opening of the inner supply duct of the first inner circuit. An additional degassing duct connects the upper portion of the reception chamber or water pump volute with an element of the engine cooling circuit.
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FIELD OF THE INVENTION
The present invention relates in general to virtual world program applications and more particularly, to methods and systems for controlling the rendering of avatars or other elements employed in these applications.
BACKGROUND OF THE INVENTION
A Virtual Universe (VU) is a computer-based simulated environment intended for its residents to traverse, inhabit, and interact through the use of avatars. Many VUs are represented using 3-D graphics and landscapes, and are populated by many thousands of users, known as “residents.” Other terms for VUs include metaverses and “3D Internet.” Often, the VU resembles the real world such as in terms of physics, houses, and landscapes. Example VUs include: Second Life®, Entropia Universe®, The Sims Online™, There™, as well as massively multiplayer online games such as EverQuest®, Ultima Online™, Lineage™ or World of Warcraft®.
It should not be assumed that the utility of virtual worlds is limited to game playing, although that is certainly seen to be useful and valuable insofar as it has become a real economic reality with real dollars being exchanged. However, the usefulness of virtual worlds also includes the opportunity to run corporate conferences and seminars. It is also used to conduct virtual world classroom sessions. Governmental and instructional opportunities abound in the virtual world. Accordingly, it should be fully appreciated that the term “virtual” as applied to this technology does not in any way make it less real or less valuable than the “real” world. It is really an extension of current reality. Moreover, it is an extension that greatly facilitates human communication and interaction in a non-face-to-face fashion.
The prevalence of virtual world residence is demonstrated by the millions of accounts that have been registered with Second Life®. Virtual worlds are typically divided into areas of land (referred to as regions in Second Life® terminology). To account for the activity of Second Life® residents, many servers are employed to keep up with the growing user base. As activity on virtual items continues to grow, the client software will be required to render more and more graphical content at increasingly higher resolutions. In the current art, this graphical content is rendered in its entirety. Granular control does not exist over which avatars to render. It is noted that, as used herein, the term “resolution” refers to several avatar aspects ranging from the number of facets used to represent an avatar, to color and spatial resolution of textures mapped to the avatar body, to the granularity of the motion of avatar body parts, et cetera.
Second Life® and other on-line virtual environments present a tremendous new outlet for both structured and unstructured virtual collaboration, gaming and exploration, as well as real-life simulations in virtual spaces. These activities, along with yet to be disclosed new dimensions, in turn provide a wide open arena for creative and new marketing methods and mechanisms.
SUMMARY OF THE INVENTION
The shortcomings of the prior art are overcome and additional advantages are provided through the construction and use of systems to reduce computational load on client VU systems when rendering complex VU scenes, through user (that is, manual) and automatic selection of the placement of graphical emphasis. Automatic selection is influenced by detection of avatar interactions, similar inventories, in-progress transactions, and company hierarchy. Here, “company” is used in the sense of which avatars are present in the same company of employment with the user's avatar.
The present invention enables virtual-universe clients to have granular (and selective) control during avatar rendering. There are two primary components or aspects to the present invention. These two components along with their subcomponents are described herein. The first component describes an avatar rendering ranking system having both manually and automated methods. The second component describes a system to reduce computational load created by a virtual universe client. The load reduction component describes several methods and modifications to a VU that result in reduced computational load.
In accordance with the present invention, there is provided a method for rendering avatars in a virtual universe environment by capturing user ranking with respect to various avatars and by dynamically rendering these avatars in accordance with this ranking.
Presently, methods do not exist to enable residents to reduce client computational load by ranking avatars, either manually or automatically. In accordance with the present invention, client computational load is reduced by either eliding, or reducing the rendering quality of avatars based on rankings.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. Furthermore, any of the components of the present invention can be deployed, managed, serviced, etc. by a service provider who offers to provide a mechanism for users of VU applications to selectively control the rendering of avatars and other aspects of the VU environment.
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a computer program product for rendering avatars in a virtual universe environment. The computer program product comprises a storage medium readable by a processing circuit and storing instructions for execution by a computer for performing a method.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. Methods and systems relating to one or more aspects of the present invention are also described and claimed herein. Furthermore, services relating to one or more aspects of the present invention are also described and may be claimed herein.
The recitation herein of desirable objects which are met by various embodiments of the present invention is not meant to imply or suggest that any or all of these objects are present as essential features, either individually or collectively, in the most general embodiment of the present invention or in any of its more specific embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of practice, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a block diagram illustrating the structural components of the present invention;
FIG. 2 is a block diagram showing the basic steps carried out in the practice of the present invention;
FIG. 3 is a block diagram illustrating a system which an end user typically employs to use the present invention; and
FIG. 4 illustrates one form of machine readable medium, a CD-ROM, on which program instructions for carrying out the steps of the present invention are provided.
DETAILED DESCRIPTION OF THE INVENTION
In order to better understand the present invention and the advantages that it produces, it is useful to provide descriptions of some of the VU concepts and terms that are encountered. The list below is exemplary and is not intended to be all inclusive.
(1) An avatar is a graphical representation a user selects that other users can see, often taking the form of a cartoon-like human but with increasing desire to render the depiction in more realistic fashion. (2) An agent is the user's account, upon which the user can build an avatar, and which is tied to the inventory of assets a user owns. (3) A region is a virtual area of land within the VU. (4) Assets, avatars, the environment, and anything visual consists of UUIDs (unique identifiers ) tied to geometric data (distributed to users as textual coordinates), textures (distributed to users as graphics files such as JPEG2000 files), and effects data (rendered by the user's client according to the user's preferences and user's device capabilities).
Note too that, throughout this disclosure, for clarity of presentation only, reference is made to an individual or avatar, which is a digital representative of the individual. However, it should be noted that this term not only applies to an individual, but to any computerized processes that may execute on behalf of the individual, using the same credentials and capabilities of the individual that owns/controls the process. In general, this embodies many forms, such as prescheduled, automatically running maintenance processes, system level processes (owned by the system administrator), etc. In all cases, this process is treated like an avatar, with the same inputs and outputs, regardless of whether the credentials come directly from an individual or from a computerized process acting in his or her stead.
FIG. 1 illustrates the basic structure of the present invention. In particular, server 100 is seen as providing support for virtual environment 130 which for practical limitations illustrates the presence of three avatars, one of which represents the current user owner. For purposes of understanding the present invention, it is best to consider the center figure as representing the user's avatar. The other figures will have their own UUID's, contexts and levels (not shown for reasons of clarity). Server 100 provides virtual environment 130 within virtual address space 110 which is allocated to the subject user. The subject user 105 acts through agent 112 . Agent 112 has access to inventory database 114 which, among other things, includes a list of objects and properties for those objects owned by the user within the virtual environment. Address space 110 is associated with the subject user through avatar UUID 116 . Address space 110 also includes avatar renderer 120 . In accordance with the present invention, it is noted that avatar renderer 120 is not only provided with avatar UUID 116 , but also with context and level information, 118 and 122 respectively, as described more particularly below.
As indicated above, there are two aspects of the present invention: avatar rendering and computational load reduction. The first of these components to be considered is avatar rendering. Furthermore, two distinct methods of determining avatar rendering importance are described: manual and automated. Both of these methods enable the client to reduce its computational load when rendering virtual universe regions.
Often, interactions between users within a VU are restricted to a small number of users. For example, avatar A is attending a virtual concert with avatar B. Both avatar A and B are friends. Avatar C is also attending the virtual concert. However, avatar C is not interested in what clothing avatar A and B are wearing, but only interested in his own friend, avatar D as well as the concert band. While the clothing of avatar A and B are not of interest to avatar C, in current art, the VU client renders all interactions which thus increases the computational load placed on the VU client.
In current art, methods do not exist for the convenient and selective reduction of computational load by modifying the rendering characteristics of avatars within a virtual universe. Nor do (manual or automatic) methods exist to select which avatar's rendering characteristics to modify. Previously unknown methods for the rendering or ranking of avatars include: avatar interaction based rankings, inventory similarity based rankings, detection of in progress business interactions and company hierarchy based rankings.
Manual
In the manual embodiment, a user is responsible for designating the relative rendering ranking of avatars.
A modification to a Virtual Universe client allows residents of that universe to denote other avatars' rendering importance. It is known for users of a virtual universe to be able to select objects within that universe. This is commonly done with an input device such as a mouse or a keyboard. Also known is for an input combination to display to the user a “context” menu for said selected object. The “context” menu commonly displays actions appropriate for the selected item. The present invention modifies the “context” menu of a virtual universe user interface adding an action to allow a ranking of rendering importance for each avatar. Those skilled in the art will note that many possible variations and combinations exist to select an object and to request an action be performed upon the object. Additionally, the selection of avatars and subsequent selection of rendering importance is applied simultaneously across multiple avatars within a visible region.
Embodiments of the present invention may differ in the number of distinct rendering importance levels or rankings. Exemplified herein is a sample embodiment that contains three levels. Level one denotes avatars to always render (and usually with high quality), level two consists of “normal avatars,” and level three denotes “extraneous” avatars. The rendering ranking for each avatar is stored as metadata associated with the avatar UUID and is made to persist in a non-volatile database. On the other hand, the selections may be ephemeral, resetting over time or upon user log-off. In another embodiment, the user may choose an avatar's rendering ranking using the UUIDs of the avatars without the use of a graphical interface.
Automatic
In the automatic embodiment, the client software is responsible for designating the rendering importance of avatars, with little or no user guidance.
As in the manual method described above, distinct rendering importance levels exist for avatars within the virtual universe. It should be noted, that while it is impractical for the manual method to make use of a large number of levels, the automated methods provides more fine-grained rendering levels, or rankings, of other avatars within the VU.
Ranking Methods: The following ranking methods are exemplary in nature and many other potential ranking methods are possible without deviating from the scope of the present invention. The ranking methods are usable in combination with each other and each type of ranking may have greater or lesser influence on the ranking, depending on the embodiment.
Avatar Interactions: If two or more avatars are involved in a chat session, the avatars involved in the chat session may be assigned a higher rendering ranking when compared with other avatars. Additionally, other interactions such as waving or handing a virtual document to another avatar should result in those avatars having a higher rendering ranking. Interaction ranking may also contain a temporal component, such that, recent interactions are ranked higher than previous interactions.
Inventory Similarities: If avatars have overlapping inventory items, there is a potential for those avatars to be interested in each other and therefore should have a higher rendering ranking than those who contain divergent inventory items. The percentage of overlap may be a factor in determining rendering ranking based on inventory similarity. For example, those with a 75% overlapping inventory should be ranked higher than those with a 12% overlapping inventory.
Business Transaction Detection: If it is determined that an avatar is involved in a business transaction with another avatar, those avatars should receive a higher rendering ranking than other avatars. Business transaction detection is achievable through parsing chat text, location within a VU (a region zoned for business), or engagement of an intra-VU fund transaction. Transaction ranking may also contain a temporal component, such that recent interactions are ranked higher than less recent interactions. It is also noted that the present model and process provides the ability to prevent select advertisements from having their rendering quality overridden, such as those supplied from platinum or gold level sponsors. Such ads may, for example, appear on billboards within the VU.
Company Hierarchy: Some embodiments may have access to a company directory which contains the company hierarchy. In such embodiments, those within a user's management chain and within his group, department, line of business, or unit should be given a higher ranking than other avatars within the company.
It should be noted that the above methods, manual and automated, might be used independently or in conjunction with each other.
Computational Load Reduction
This component uses the rendering rankings computed by the Avatar Rendering Ranking Component to reduce computational load on the client.
Invocation: Several potential methods exist for invoking the computational load reduction component.
Manual Invocation: Manual invocation occurs at the request of the user who is typically in control of many aspects of the virtual universe (VU) client. For example, the user is using his PC that runs the VU client. The user may choose to engage the system application for any reason, including but not limited to: observation of system slowdown, preference for enhanced performance, the need to be undistracted by unimportant avatars, the need to find important avatars or avatars of interest, etc. System invocation may take many forms known in the art of user interface design. Some potential invocations methods include: selecting an icon, activation with a keyboard hot key, selection from a menu, voice instructions, mouse pointing, etc.
Constant Invocation/Manual Deactivation: Some embodiments may enable the load reduction system by default. In such embodiments the system is always engaged. Furthermore, a subset of these embodiments may provide the user with a manual deactivation method to disable the system
Load-based invocation: More complex embodiments may engage the load reduction system by measuring the computational load on the client system. Such embodiments periodically poll the client system to obtain metrics describing the current system load. Load can include such factors as system memory usage, page faults, graphic memory usage and CPU statistics including run queue length, wait queue length, system queue length, etc. The previous are examples and many substitute metrics may be used without deviating from the core idea of the present invention. Note that predicted load and usage may be also be considered. For example, if usage trends indicate that in 15 minutes the VU will be very slow, engagement of the system may take place.
Load Reduction
Upon invocation, steps are taken to reduce the computational load on the client for rendering the virtual universe. Several example methods for reducing computational load are described below.
Polygon/Triangle Reduction: To reduce computational load on either the CPU (Central Processing Unit) or GPU (Graphical Processing Unit) the client may reduce the number of polygons required to render an avatar. In 3D rendering, polygons and triangles are the primitive objects which make up complex 3D objects such as avatars. Reducing the number of polygons and triangles for an avatar reduces the load on the system during the graphical rendering process called rasterisation. Rasterisation is well known in the art of 3D rendering and is the method used by virtually all current GPUs to create realistic images. Simple calculations may be performed in real time to reduce the number of polygons that are required for each animated frame within a virtual universe. These calculations replace many smaller polygons and triangles with larger such primitives. Reducing primitives results in a lower quality and less realistic rendering. It is also possible to use zero polygons and simply render the avatars as line segments.
Frame Rate Reduction: A second method to reduce load is to modify the frame rate for rendering individual avatars within a virtual universe. As with movies and television, smooth motion within a virtual universe is an illusion created by rapidly changing static images. Another term for these static images is rendered frames. Each avatar within each frame takes computational load to render. If the number of times an avatar was rendered per time period was reduced, the computational load would likewise be reduced. In such systems the last previously rendered avatar image would be cached and used for subsequent frames. Such a reduction may result in avatars having jerky movement throughout the virtual universe.
Texture/Lighting Elision: A third optimization method is the elimination of texturing mapping and lighting calculations for individual avatars within a virtual universe. Texture mapping is the process of applying a flat texture stored in image format to a three dimensional shape. Texture mapping is a computationally intensive process and eliminating this process reduces load on the client. Without textures, the avatars may be rendered in a “wireframe” format. Other embodiments may display avatars without textures as primitives (cones, cubes, tubes, etc) as solid textures. A second optimization that may be used with or without texture elision is to eliminate lighting calculations from avatar rendering. Lighting calculations are computationally intensive operations that modify the brightness, shading and other visual characteristics of an object by realistically simulating how light (directional and omnidirectional) affects an object. Removing lighting (and the time and resource consuming calculations associated therewith) results in less realistic avatar representations. The number of lighting sources are reduced or even eliminated as one method for controlling the requirements for controlling avatar rendition. Furthermore, while focus herein has been directed to reducing avatar detail, more generally it is directed also to methods for controlling avatar rendition.
Avatar Elision: Another optimization method is the elimination of an avatar which would otherwise be rendered within a scene. This method typically saves more computational resources than any previously described method.
It should be noted that the above methods are usable independently or in conjunction with each other. The combination of methods to use and the level of reduction within each method is dependent on the rankings provided by the previously described ranking component.
It is noted that aggregate ranking information is desirable for use by advertisers. Those avatars with a high rendering ranking may be candidates to have advertising information (logos, teleport invitations, etc) as part of their avatar rendering. While this disclosure focuses on avatars, the methods and systems of the present inventions are equally applicable to other rendered objects within a virtual universe.
In yet another embodiment, the present invention provides a business method that performs the process steps of the invention on a subscription, advertising, and/or fee basis. That is, a service provider, such as a Solution Integrator, offers to provide both manual and automatic avatar (or object) rendering under selective control of the user as to its use and the parameters employed to carry out avatar rendering. In this case, the service provider creates, maintains, supports, etc., a computer infrastructure that performs the process steps of the invention for one or more customers. In return, the service provider receives payment from the customer(s) under a subscription and/or fee agreement and/or the service provider receives payment from the sale of advertising content to one or more third parties.
FIG. 2 illustrate the two basic steps employed in the present invention: (step 201 ) capturing user ranking with respect to at least one avatar; and (step 202 ) dynamically rendering at least one avatar in accordance with the captured user ranking.
In any event an end user environment in which the present invention operates is shown in FIG. 3 . The present invention operates through a data processing environment which effectively includes one or more of the computer elements shown in FIG. 3 . While FIG. 3 is more suited for illustrating an end user environment, it is noted that a similar, albeit typically much larger, data processing system is connected via the Internet to the local environment depicted. In particular, a similar non-volatile memory 540 is typically present at the server end to contain program instructions for carrying out the virtual reality program which are loaded into a corresponding main memory 510 for execution. Turning to a local focus, computer 500 includes central processing unit (CPU) 520 which accesses programs and data stored within random access memory 510 . Memory 510 is typically volatile in nature and accordingly such systems are provided with nonvolatile memory typically in the form of rotatable magnetic memory 540 . While memory 540 is preferably a nonvolatile magnetic device, other media may be employed. CPU 530 communicates with users at consoles such as terminal 550 through Input/Output unit 530 . Terminal 550 is typically one of many, if not thousands, of consoles in communication with computer 500 through one or more I/O unit 530 . In particular, console unit 550 is shown as having included therein device 560 for reading medium of one or more types such as CD-ROM 600 shown in FIG. 4 . Media 600 , an example of which is shown in FIG. 4 , comprises any convenient device including, but not limited to, magnetic media, optical storage devices and chips such as flash memory devices or so-called thumb drives. Disk 600 also represents a more generic distribution medium in the form of electrical signals used to transmit data bits which represent codes for the instructions discussed herein. While such transmitted signals may be ephemeral in nature they still, nonetheless constitute a physical medium carrying the coded instruction bits and are intended for permanent capture at the signal's destination or destinations.
While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and changes therein may be effected by those skilled in the art. Accordingly, it is intended by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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The rendering of avatars in a virtual universe is selectively controlled by the avatar owner. Avatar ranking by several criteria, operating either jointly or independently, is employed to control avatar rendering in ways intended to reduce computational loading while not significantly impacting the virtual universe experience.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to building construction systems and more particularly to building construction systems for installing metal studs in metal tracks for the framing in drywall construction.
Description of the Related Art
Both interior and exterior walls in building construction generally consist of vertical studs which are held between a floor joist and a ceiling joist. Generally the studs are of 2×4 or 2×6 wood studs and are covered by plywood, if an exterior wall or gypsum wallboard, if an interior wall.
However, in modern commercial construction the wooden studs and joists, in non-load-bearing walls, are replaced by metal studs and tracks, primarily for fire resistance considerations. The metal studs are covered by drywall, i.e., gypsum wallboard, which holds the metal studs in place, since the wallboard is fastened to the studs and tracks.
The studs and tracks are both U-shaped members formed from sheet metal, for example, galvanized steel. The width of the stud may be typically 33/4 inches and the interior width of the track is also 31/4 inches to accommodate the width of the studs.
The installation of the metal studs into metal tracks has proven to be relatively time-consuming. For example, the installer will measure and mark the location of a metal stud, place a metal stud in a metal track at the marked location, drive a first screw through a stud wall and track wall at the bottom of the stud and drive a second screw through a stud wall and track wall at the top of the stud. Sometimes the studs are not aligned vertically, i.e., they tilt, which may make it difficult to locate them when attaching the wallboard.
The only purpose of the top and bottom screws holding the stud in the top and bottom tracks is to hold them in vertical alignment until the wallboard is fastened to the studs and tracks.
In U.S. Pat. No. 4,787,767 a stud clip holds studs in ceiling and floor rails. The studs are screwed to the stud clips.
In U.S. Pat. No. 4,850,169 and Des. 301,745 studs are snapped into specially shaped holes in the bottom walls of tracks.
SUMMARY OF THE INVENTION
The present invention provides a metal track system which is adapted to receive and hold conventional metal studs in correctly aligned vertical positions.
The tracks are U-shaped and formed of sheet metal. The tracks are only of one shape and size, for each width of stud, so the tracks may be used on the floor and on top of the studs. The tracks have spaced protrusion means to hold the studs. Preferably the protrusion means are four raised dimples or lances. Two dimples or lances are located spaced apart 11/4 inches on each of the opposite walls of the track. The protrusion means are spaced, preferably at 8-inch centers, along the length of the tracks.
To install a stud, the installer simply places a stud within a track next to the protrusion means on the bottom and top tracks and snaps the stud into place. There is no need for screws to hold the stud in place, as the stud is held correctly vertically aligned by the protrusion means in the bottom and top tracks.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description should be taken in conjunction with the accompanying drawings.
In the drawings:
FIG. 1 is a front view of the stud and track system of the present invention;
FIG. 2 is a perspective view of the first embodiment of the track of the present invention;
FIG. 2A is an end view of the track of FIG. 2;
FIG. 2B is an enlarged cross-sectional view of the track of FIG. 2 taken along the line A--A of FIG. 2;
FIG. 3 is a top view of the track of the second embodiment;
FIG. 4 is a side view of the track of FIG. 3;
FIG. 5 is a top view of the track of the third embodiment; and
FIG. 6 is a side view of the track of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the metal track metal stud system of the present invention includes a horizontal aligned bottom track 10, a horizontal aligned top track 11, and a series of vertical aligned studs 12a, 12b, 12c, etc. Generally the bottom track 10 is fastened to the floor, the top track 11 is secured to ceiling support members, and the studs 12a-12e are held in the top track 10 and bottom track 11.
As shown in FIG. 2, the studs are positioned in the tracks by protrusion means 13. In the first embodiment, the protrusion means are indentations inward toward the imaginary center of the U-shaped tracks 10 and 11. Each protrusion means 13 consists of four indentations 20,21 on one arm 22 (sidewall) of track 10 and two indentations 23,24 on the opposite arm 25 (sidewall).
The studs and track are typically formed from hot dipped galvanized rolled steel in 14, 16, 18, 20 and 24 gauge metal.
The studs generally are 8, 10 or 12 feet long and the tracks are 10 or 12 feet long.
The distance from one dimple to another dimple, on a track sidewall, is preferably 1 7/16 inch, taken from the dimple centers, to accommodate a 11/4 inch height of the arms (sidewalls) of the stud. The width of the studs is generally 15/8, 2, 21/2, 3, 35/8, 4 or 6 inches. The tracks have the same widths, for non-load-bearing walls, as the studs. For example, the width of the stud 12a (bottom wall) is 21/2 inches, the left arm (sidewall) and right arm (sidewall) are in the range 1.250 to 1.360 inches high and preferably 1.250 (11/4) inch high.
As shown in FIGS. 1, 2, 2A and 2B the indentations 20, 21, 23 and 24 are hemispherical dimples. The preferred size of a dimple, at its base, is 5/16-inch in circumference, measured at the outside of the wall, and its preferred height is about 1/8-inch.
The track's width matches the width of the studs; for example, a 21/2 inch wide track would be used with 21/2 inch wide stud. The height of the track sidewalls 22,25 is in the range of 1.125-inch to 1.250-inch.
The first and last sets of four indentations are spaced the same distance from the two ends of the track as the width of the studs, for example, 21/2 inches for 21/2 inch wide studs. Then the indentations are spaced every 8 inches (distance a in FIG. 2) so that the studs may be erected at either 16- or 24-inch spacings measured center-to-center.
In the embodiment shown in FIGS. 3 and 4, the protrusion means consist of inwardly directed sheet metal flaps which are lanced from the sidewalls of the tracks. Track 50 in FIGS. 3 and 4 is shown with three sets of protrusion means 51, 52, 53. Each set consists of two spaced-apart flaps. For example, protrusion means set 51 has flaps 54,55 lanced from sidewall 56 and flaps 57,58 lanced from sidewall 59 all of which flaps are within the track 50. The flaps function in the same manner as the dimples of the prior embodiment to position and hold the studs.
The flaps are shown in FIGS. 3 and 4 as being flat. Alternatively, and shown in FIGS. 5 and 6, they may be L-shaped, with the bottoms of the L shapes facing each other. Flaps 61 and 62 are L-shaped and lanced from the sidewalls 63 and 64, respectively, of track 60.
The embodiments shown in the drawings FIGS. 1-4 use protrusion means which grip the studs by friction and by the spring-like function of the studs. However, the protrusion means may be used on only one side of the studs as a guidance means, without gripping the studs, as shown in FIGS. 5 and 6. For example, in FIG. 3 such a guidance means would be only the flaps 57 and 54 in set 51, without flaps 58 and 55.
The tracks may have printed vertical lines on the exterior of their sidewalls to indicate the centers of the 8-inch spacings of the protrusion means as a guide for the installer. The dimples may be at one height on one sidewall and a different height on the opposite sidewall.
Other modifications may be made in the present invention within the scope of the claims.
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Framing for drywall building construction consists of vertical metal U-shaped studs whose ends are positioned with U-shaped metal top and bottom tracks. The tracks have spaced sets of inward protrusions, preferably dimples, formed from the sidewalls of the tracks. The studs are snapped into the sets of protrusions and held therein.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This non-provisional U.S. patent application is a divisional application of and claims priority to U.S. non-provisional application Ser. No. 12/479,626, filed Jun. 5, 2009, now U.S. Pat. No. 8,309,746, which claims priority to U.S. provisional application Ser. No. 61/059,658 filed Jun. 6, 2008, all of which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
Invention embodiments relate to methods for preparing 17-Ethynyl-10R,13S-dimethyl 2,3,4,7,8R,9S,10,11,12,13,14S,15,16,17-hexadecahydro-1H-cyclopenta[a]phenanthrene-3R,7R,17S-triol and other pharmaceutically active compounds related thereto, that are essentially free of reaction steroid impurities having undesired binding activity at sex steroid receptors.
BACKGROUND OF THE INVENTION
17-Ethynyl-10R,13S-dimethyl2,3,4,7,8R,9S,10,11,12,13,14S,15,16,17-hexadecahydro-1H-cyclopenta[a]phenanthrene-3R,7R,17S-triol (also referred to herein as 17α-ethynyl-androst-5-ene-3β,7β,17β-triol or Compound 1) is effective in treating conditions that are attributable to chronic non-productive inflammation. In contrast to other anti-inflammatory steroids, Compound 1 has been found to be essentially free of binding activity at nuclear sex steroid receptors, activity which can contribute to unwanted side effects from such compounds. Steroid synthetic intermediates, by-products, side products or other such impurities that can affect or modulate sex steroid receptor activity(ies) and may be present in preparations of Compound 1 are undesirable, since they contribute to side effects. Thus, methods for preparing Compound 1 and analogs and derivatives thereof that avoid production of impurities, such as synthetic intermediates, steroid side-products or byproducts that affect or modulate nuclear sex steroid activity(ies) are useful.
SUMMARY OF THE INVENTION
Reaction sequences to provide 17α-alkynyl-androst-5-ene-3β,7β,17β-triol have unexpectedly been found to produce material containing undesired steroid impurity(ies) that impart sex steroid receptor activity(ies) that otherwise would not be present to the material. These impurities adversely affect the pharmaceutical acceptability of the 17α-alkynyl-androst-5-ene-3β,7β,17β-triol. The presence of these impurities in preparations of 17α-alkynyl-androst-5-ene-3β,7β,17β-triol has not been described and their presence adds additional cost to remove or reduce their presence to a level at which the sex steroid activity(ies) would not be present. The reaction sequences disclosed herein avoid production of the undesired steroid impurity(ies) and thus avoid the need for purification of the 17α-alkynyl-androst-5-ene-3β,7β,17β-triol so produced to effect removal or reduction in level of the impurity(ies).
One embodiment of the invention provides a reaction sequence for introducing an alkynyl group at position 17 and an oxygen functionality at position 7 to an androst-5-ene having an oxygen linked group at position 3 and a ketone at position 17 such that a side-product lacking a oxygen substituent at C-7, and thus having undesired binding activity at sex steroid receptors, is precluded.
Another embodiment of the invention provides a reaction sequence for introducing an ethynyl group at position 17 and a hydroxy group at position 7 to dehydroepiandrosterone (also referred herein as DHEA or 3β-hydroxy-androst-5-ene-17-one) such that a preparation of Compound 1 is formed that is essentially free of binding activity at sex steroid receptors.
In another embodiment of the invention provides for a reaction sequence that uses DHEA as starting material to obtain a preparation containing Compound 1 that is essentially free of the estrogenic compound 17α-ethynyl-androst-5-ene-3β,17β-diol or its potential precursor 17α-ethynyl-3β-acetoxy-androst-5-ene-17β-ol.
In one embodiment of the invention the reaction sequence comprises a prior step of oxidizing an appropriately protected androst-5-ene having a first and second oxygen linked group at positions 3 and 17 such that a third oxygen linked group is introduced at position 7 and a subsequent step of reacting an intermediate wherein the second oxygen linked group at position 17 is ═O with an anion derived from an alkyne.
In another embodiment of the invention the reaction sequence comprises a prior step of oxidizing DHEA, appropriately protected, to introduce a third oxygen linked group at position 7 and a subsequent step of reacting of an intermediate having the substituent ═O at position 17 with an acetylene anion, optionally protected.
In another embodiment of the invention the reaction sequence comprises the step of reacting androst-5-en-17-one-3β,7β-diol, appropriately protected, with an anion derived from an alkyne.
DETAILED DESCRIPTION
Definitions
As used herein and unless otherwise stated or implied by context, terms that are defined herein have the meanings that are specified. The descriptions of embodiments and examples that are described illustrate the invention and they are not intended to limit it in any way. Unless otherwise contraindicated or implied, e.g., by including mutually exclusive elements or options, in these descriptions and throughout this specification, the terms “a” and “an” mean one or more and the term “or” means and/or.
“Alkyl” as used here refers to linked normal, secondary, tertiary or cyclic carbon atoms, i.e., linear, branched, cyclic or any combination thereof. Alkyl groups or moieties, as used herein, may be saturated, or unsaturated, i.e., the moiety may comprise one, two, three or more independently selected double bonds or triple bonds. Unsaturated alkyl moieties include moieties as described below for alkenyl, alkynyl, cycloalkyl, and aryl moieties. The number of carbon atoms in an alkyl moiety is 1-20, preferably 1 to 8. C 1-8 alkyl or C1-8 alkyl means an alkyl moiety containing 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms and C 1-6 alkyl or C1-6 alkyl means an alkyl moiety containing 1, 2, 3, 4, 5 or 6 carbon atoms. When an alkyl moiety is specified, species may include methyl, ethyl, 1-propyl (n-propyl), 2-propyl (iso-propyl, —CH(CH 3 ) 2 ), 1-butyl (n-butyl), 2-methyl-1-propyl (iso-butyl, —CH 2 CH(CH 3 ) 2 ), 2-butyl (sec-butyl, —CH(CH 3 )CH 2 CH 3 ), 2-methyl-2-propyl (t-butyl, —C(CH 3 ) 3 ), 1-pentyl (n-pentyl), 2-pentyl (—CH(CH 3 )CH 2 CH 2 CH 3 ), 3-pentyl (—CH(CH 2 CH 3 ) 2 ) and 2-methyl-2-butyl (—C(CH 3 ) 2 CH 2 CH 3 ).
“Cycloalkyl” as used here refers to a monocyclic, bicyclic or tricyclic ring system composed of only carbon atoms. The number of carbon atoms in an cycloalkyl group or moiety can vary and typically is 3 to about 20, e.g., preferably 3-8. C 3-8 alkyl or C3-C8 alkyl means an cycloalkyl moiety containing 3, 4, 5, 6, 7 or 8 carbon atoms and C 3-6 alkyl or C3-C6 means an cycloalkyl moiety containing 3, 4, 5 or 6 carbon atoms. Preferred cycloalkyl substituents are cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and adamantyl. Cycloalkyl substituents having a double bond within the cyclic ring system are sometimes referred to as cycloalkenyl substituents.
“Alkenyl” as used here means a moiety or group that comprises one or more double bonds (—CH═CH—), e.g., 1, 2, 3, 4, 5, 6 or more, typically 1, 2 or 3 and can include an aryl moiety such as benzene, and additionally comprises linked normal, secondary, tertiary or cyclic carbon atoms, i.e., linear, branched, cyclic or any combination thereof unless the alkenyl moiety is vinyl (—CH═CH 2 ). An alkenyl moiety with multiple double bonds may have the double bonds arranged contiguously (i.e., a 1,3 butadienyl moiety) or non-contiguously with one or more intervening saturated carbon atoms or a combination thereof, provided that a cyclic, contiguous arrangement of double bonds do not form a cyclically conjugated system of 4n+2 electrons (i.e., aromatic). The number of carbon atoms in an alkenyl moiety can is 2-20, preferably 2-8. C 2-8 alkenyl or C2-8 alkenyl means an alkenyl moiety containing 2, 3, 4, 5, 6, 7 or 8 carbon atoms and C 2-6 alkenyl or C2-6 alkenyl means an alkenyl moiety containing 2, 3, 4, 5 or 6 carbon atoms. When an alkenyl moiety is specified, species include, e.g., any of the alkyl moieties described above that has one or more double bonds such as methylene (═CH 2 ), methylmethylene (═CH—CH 3 ), ethylmethylene (═CH—CH 2 —CH 3 ), propylmethylenes (═CH—CH 2 —CH 2 —CH 3 ), vinyl (—CH═CH 2 ), allyl (—CH═CHCH 3 ), 1-methylvinyl, butenyl, iso-butenyl, 3-methyl-2-butenyl or 1-pentenyl.
“Alkynyl” as used herein refers to linked normal, secondary, tertiary or cyclic carbon atoms where one or more triple bonds (—C≡C—) are present, typically 1, 2 or 3, usually 1, optionally comprising 1, 2, 3, 4, 5, 6 or more double bonds, with the remaining bonds (if present) being single bonds and comprising linked normal, secondary, tertiary or cyclic carbon atoms, i.e., linear, branched, cyclic or any combination thereof, unless the alkynyl moiety is ethynyl. The number of carbon atoms in an alkynyl group or moiety is 2 to 20, preferably 2-8. C 2-8 alkynyl or C 2-8 alkynyl means an alkynyl moiety containing 2, 3, 4, 5, 6, 7 or 8 carbon atoms. When an alkynyl substituent is specified, preferred species include, —C≡CH, —C≡CCH 3 , —C≡CCH 2 CH 3 , —C≡CC 3 H 7 and —C≡CCH 2 C 3 H 7 . Particularly preferred species are ethynyl, propynyl and 1-butynyl with ethynyl especially preferred.
“Aryl” as used herein refers to an aromatic ring system or a fused ring system with no ring heteroatoms comprising 1, 2, 3 or 4 to 6 rings, typically 1 to 3 rings; wherein the rings are composed of only carbon atoms; and refers to a cyclically conjugated system of 4n+2 electrons (Hückel rule), typically 6, 10 or 14 electrons some of which may additionally participate in exocyclic conjugation (cross-conjugated). When an aryl group is specified, species may include phenyl, biphenyl, naphthyl, phenanthryl and quinone.
“Heteroaryl” as used here refers means an aryl ring system wherein one or more, typically 1, 2 or 3, but not all of the carbon atoms comprising the aryl ring system are replaced by a heteroatom which is an atom other than carbon, including, N, O, S, Se, B, Si, P, typically, oxygen (—O—), nitrogen (—NX—) or sulfur (—S—) where X is —H, a protecting group or C 1-6 optionally substituted alkyl, wherein the heteroatom participates in the conjugated system either through pi-bonding with an adjacent atom in the ring system or through a lone pair of electrons on the heteroatom and may be optionally substituted on one or more carbons or heteroatoms, or a combination of both, comprising the heterocycle in a manner which retains the cyclically conjugated system.
“Protecting group” as used here means a moiety that prevents or reduces the atom or functional group to which it is linked from participating in unwanted reactions. For example, for —OR PR , R PR is a protecting group for the oxygen atom found in a hydroxyl, while for ═O the protecting group is a ketal or thioketal wherein the divalent oxygen is replaced, for example, by —X—(CH 2 ) n —Y—, wherein X and Y independently are S and O and n is 2 to 3, to form a spiro ring system or an oxime wherein the divalent oxygen is replaced by ═N—OR, wherein R is —H, alkyl or aryl. For —C(O)—OR PR , R PR is a carbonyloxy protecting group, for —SR PR , R PR is a protecting group for sulfur in thiols for instance, and for —NHR PR or —N(R PR ) 2 —, R PR is a nitrogen atom protecting group for primary or secondary amines. The protecting groups for sulfur or nitrogen or monovalent oxygen atoms are usually used to prevent unwanted reactions with electrophilic compounds. The protecting groups for divalent oxygen atoms (i.e. ═O) are usually used to prevent unwanted reactions with nucleophilic compounds.
“Optionally substituted alkyl”, “optionally substituted alkenyl”, “optionally substituted alkynyl”, “optionally substituted heterocycle”, “optionally substituted aryl”, “optionally substituted heteroaryl” and the like mean an alkyl, alkenyl, alkynyl, aryl, heteroaryl or other group or moiety as defined or disclosed herein that has a substituent(s) that optionally replaces a hydrogen atom(s). Such substituents are as described above. For a phenyl moiety (-Ph), the arrangement of any two substituents present on the aromatic ring can be ortho (O), meta (m), or para (p) to each other. Preferred optionally substituted moieties are —CF 3 , —CH 2 OH, —C≡C—Cl and -Ph-F.
“O-linked group”, O-linked substituent and like terms as used herein refers to a group or substituent that is attached to a moiety directly though an oxygen atom of the group or substituent. An O-linked group may be monovalent including groups such as —OH, acetoxy, i.e., —O—C(O)—CH 3 , acyloxy, i.e., —O—C(O)—R wherein R is —H, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl or optionally substituted heterocycle, aryloxy (Aryl-O—), phenoxy (Ph-O—), heteroaryloxy (Heteroaryl-O—), silyloxy, i.e. R 3 SiO— wherein R independently are alkyl or aryl, optionally substituted or —OR PR wherein R PR is a protecting group as previously defined or may be divalent, i.e. ═O.
The term “preparation of Compound 1” refers to material prepared according to any one of the synthetic schemes specifically or generically described and includes Compound 1 wherein Compound 1 is found as the major component on a mass basis and process impurities, present either in Compound when initially isolated as a solid or after recrystallization and-or purification of the solid.
The term “binding activity” refers to the ability of a specified compound, a preparation comprising Compound 1 or impurity (or impurities) in a preparation of Compound 1 to bind to or associate with a receptor, typically a sex steroid receptor such as an androgen receptor or an estrogen receptor to effect or modulate the receptor's biological activity. Binding is usually measured in assays as the capacity of a compound, usually an impurity in a preparation comprising Compound 1, to displace a physiologically relevant ligand of a receptor (i.e., reference ligand) that is bound to that receptor in a competition assay. The reference ligand is typically a natural ligand of the receptor or an agonist of the receptor that has been labeled with a radioactive or spectroscopic probe whose presence may be queried by scintillation counting or by a spectroscopic method such as fluorescence emission or fluorescence polarization.
The radioactive probe is typically 3 H and/or 14 C, where radioactive atom(s) have replaced one or more of atoms of the ligand at positions where loss of the radiolabel would not occur to an extent under conditions of the assay that would complicate or confound interpretation of the assay results. The spectroscopic probe is typically a fluorophore that is attached to a reference ligand at a position that provides a labeled reference ligand that has a K d in the range of 0.1-100 nM at positions and will not lose the fluorescent label to an extent under conditions of the assay that would complicate or confound interpretation of the assay results. The binding activity of the specified compound or a preparation of Compound 1 is typically expressed by K i , wherein K i is determined from the concentration the specified compound or preparation to displace the labeled reference ligand to the receptor by 50% and the Kd of the labeled reference ligand.
“Sex steroid receptor” refers to nuclear receptors normally associated with affecting the growth or function of the reproductive organs and the development of secondary sex characteristics and includes androgen receptor, estrogen receptor-α (ERα), estrogen receptor-β (ERβ) and progesterone receptor.
“Essentially free” as used herein refers to a property of or an impurity in a preparation of Compound 1 as not being present or measurable in an amount that would adversely affect or detract from the desired pharmacological activity of Compound 1. For example, the term “essentially free of sex steroid receptor binding activity” refers to the absence of receptor binding activity for a preparation of Compound 1 to nuclear sex steroid receptors as defined by values of K i >10 μM for binding to those receptors, as determined using standard receptor binding assay conditions, and is irrespective of the identity of the impurity that may be present in the preparation that would give rise to the sex receptor binding activity. Likewise, essentially free of estrogen receptor binding activity estrogen receptors refers to the absence of receptor binding activity for a preparation of Compound 1 to nuclear estrogen receptors ERα and ERβ as defined by values of K i >10 μM for binding to those receptors, as determined using standard receptor binding assay conditions, and is irrespective of the identity of the impurity that may be present in the preparation that would give rise to the estrogen receptor binding activity. When the term “essentially free” is used to describe the amount of an impurity present in a preparation of Compound 1, the term means the impurity is not present in an amount that would adversely affect the pharmacological activity of Compound 1 for its intended use by contributing to side effects normally attributable to activation of nuclear estrogen receptor that are due to binding activity of the impurity at these receptors. The impurity (e.g., 17α-ethynyl-androst-5-ene-3β,17β-diol) may directly affect the pharmacological activity of Compound 1 by binding or modulating the estrogen receptor or may indirectly affect the pharmacological activity of Compound 1 by its conversion in a subject being treated with a composition comprising a preparation of Compound 1 by hydrolysis (either spontaneously or enzymatically) to a compound that does affect or modulate the estrogen receptor (e.g., 17α-ethynyl-3β-acetoxy-androst-5-ene-17β-ol converting to 17α-ethynyl-androst-5-ene-3β,17β-ol).
The terms “impurity” or “process impurity” as used herein refers to a component in a preparation of Compound 1 that is a steroid byproduct, side-product or a degradation product formed during synthesis of Compound 1 and represents a minority contribution to the overall mass of the preparation, typically less than about 2%.
“Formulation” or “pharmaceutically acceptable formulation” as used herein refers to a composition comprising a preparation of Compound 1, and one or more pharmaceutically acceptable excipients.
The inventions described herein provide for methods of preparing 17-alkynyl steroids having oxygen substituents at positions 3, 7 and 17 that are essentially free of impurities that have undesired binding activity at sex steroid receptors. Such 17-alkynyl steroids so prepared are essentially free of one or more impurities that are characterized by lacking the oxygen substituent at C7, which are responsible for the undesired binding activity.
The present methods were developed in response to unexpected estrogenic effects seen with Compound 1. Compound 1 was prepared by the route comprising the following steps referred to as Process A:
(1) Contacting a suitably protected acetylene anion with suitably protected dehydroepiandrosterone to introduce the ethynyl group at position 17α by addition of the acetylene anion to the ═O functional group at position 17;
(2) Contacting suitably protected 17α-ethynyl-androst-5-ene-3β,17α-diol with an oxidizing agent to introduce the ═O functional group at position 7; and
(3) Contacting suitably protected 17α-ethynyl-androst-5-en-7-one-3β,17α-diol with a reducing agent to directly convert the ═O functional group at position 7 to β-hydroxyl.
An embodiment of Process A is given in Scheme I (herein referred to as Process A, Route 1). Compound 1 so produced was unexpectedly found to have estrogenic effects. Impurity profiling of Compound 1 prepared by this route showed the presence of 17α-ethynyl-androst-5-ene-3β,17β-diol, which has the same structure as Compound 1 except the β-hydroxy group at position 7 is absent. Receptor binding studies showed that 17α-ethynyl-androst-5-ene-3β,17β-diol had significant binding activity at the estrogen receptors ERα and ERβ, whereas Compound 1 essentially free of this impurity possessed no activity at these receptors when tested to 10 μM. Based upon this undesired sex steroid activity, a new process, referred to as Process B, was developed that circumvented production of the estrogenic side product 17α-ethynyl-androst-5-ene-3β,17β-diol.
Process B comprises the following steps.
(a) Contacting a suitably protected dehydroepiandrosterone with an oxidizing agent to directly introduce the ═O functional group at position 7;
(b) Contacting a suitably protected androst-5-en-7,17-dione-3,3-ol with a reducing agent to convert the ═O functional group at position 7 to β-hydroxyl;
(c) Contacting a suitably protected acetylene anion with suitably protected androst-5-en-17-one-3β,7β-diol to introduce the ethynyl group at position 17α by addition of the acetylene anion to the ═O functional group at position 17.
Procedures to effect step (a) include microbial oxidation as described in Wuts, P. G. M. “A chemobiological synthesis of eplerenone” Synlett (3): 418-422 (2008); oxidation with oxo-chromium based reagents [e.g., see Koutsourea, et al., “Synthetic approaches to the synthesis of a cytostatic steroidal B-D bilactam” Steroids 68: 569-666 (2003) and Condom, et al., “Preparation of steroid-antigens through positions of the steroid not bearing functional groups” Steroids 23: 483-498 (1974)], peroxide assisted allylic oxidation [e.g., see Marwah, P., et al. “An economical and green approach for the oxidation of olefins to eneones” Green Chem. 6: 570-577 (2004) and Marwah, P., et al., “Ergosteroids IV: synthesis and biological activity of steroid glucuronosides, ethers and alkylcarbonates” Steroids 66: 581-595 (2001)], oxidation with N-hydroxysuccimimide/AIBN [e.g., see Lardy, et al. “Ergosteroids II: Biologically active metabolites and synthesis derivatives of dehydroepiandrosterone” Steroids 63:158-165 (1998)].
For step (a), a suitably protected dehydroepiandrosterone has the 3β-hydroxyl and ═O functional groups protected with protecting groups typically employed for hydroxyl and ketone given in Greene, T. W. “Protecting groups in organic synthesis” Academic Press, 1981. The hydroxy protecting group should be suitable for conditions required to (1) protect the ═O functional group at position 17, if not already present, or (1′) does not require conditions to introduce that adversely effect a ketone protecting group previously introduced to position 17, and (2) introduce directly the ═O functional group at position 7. Preferred hydroxy protecting groups are also suitable for conditions required to (3) reduce the ═O functional group to be introduced at position 7 with sufficient selectivity to provide 7β-hydroxy as the predominant isomer and (4) removed under conditions where an allyl alcohol that is formed by the ═O functional group reduction has sufficient stability. Hydroxy protecting groups meetings conditions (1)-(4) include ester, usually aryl ester or C1-6 alkyl ester, when the protecting group for the ═O functional group at position 17 is ketal and the reducing agent to be used is a borohydride based reducing agent. Use of a stronger hydride reducing agent would require a hindered ester or substituted methyl ether as the hydroxy protecting group to prevent premature loss of the hydroxy protecting group. Preferred ═O protecting groups are ketal, such as dimethyl ketal, diethyl ketal or the spiro ketal prepared from ethylene glycol. A preferred suitably protected dehydroepiandrosterone is the ethylene ketal of 3β-acetoxy-androst-5-en-17-one.
Procedures to effect step (b) include reduction with metal hydride based reagents such as the borohydride based reagents that include Zn(BH 4 ) 2 , NaBH 4 , optionally with a transition metal salt such as CeCl 3 , NiCl 2 , CoCl 2 or CuCl 2 , L-Selectride (lithium tri-sec-butylborohydride) or N-Selectride (sodium tri-sec-butylborohydride). Lithium aluminum hydride based or sodium aluminum hydride reagents may also be used although selectivity may suffer due to the reducing strength of such reagents. This may be ameliorated by using lithium aluminum hydride based reagents having alkoxy ligands to aluminum to reduce reactivity. Such reagents have the general formula LiAl—H n (OR) 4-n , where n=1, 2, 3, R is C1-6 alkyl and include LTMA (lithium triethoxyaluminum hydride LTEAH (lithium triethoxyaluminum hydride), RED-AL (Sodium bis(2-methoxyethoxy)aluminium hydride). Reduction using borohydride based reagents may be conducted in alcohol solvents whereas reductions with aluminium hydride based reagents require an ether solvent such as THF. Selectivity may be improved, particularly for the aluminum hydride reagents, by conducting the reaction at temperature of between 0° C. to −78° C. with lower temperatures being more suitable for the aluminum hydride reagents.
Procedures to effect step (c) include in situ preparation of an acetylene anion followed by contact of the acetylide so formed with a suitably protected androst-5-en-17-one-3β,7β,17β-triol. The acetylide may be prepared by contacting acetylene with an amide anion (e.g., NaNH 2 ) in a hydrocarbon solvent such as benzene, toluene or xylene, as for example in U.S. Pat. No. 2,251,939, with sodium or potassium metal in liquid ammonia, as for example in U.S. Pat. No. 2,267,257, or by contacting a mono-silyl protected acetylene such as trimethylsilyl acetylene with an organolithium reagent. Suitable organolithium reagents include commercially available n-butyl lithium, sec-butyl lithium, methyl lithium, t-butyl lithium or phenyl lithium or can be prepared by reaction of an alkyl or aryl bromide with metallic lithium in an inert solvent such as diethyl ether or tetrahydrofuran. The acetylide so prepared is then contacted with a suitably protected androst-5-en-17-one-3β,17β-diol.
For step (c), a suitably protected androst-5-en-17-one-3β,7β-diol will have hydroxyl protecting groups that are typically used in carbanion chemistry and may be removed under conditions that are compatible with the presence of a terminal alkyne and an allylic alcohol and include protecting groups that are removed under neutral or mildly acidic conditions, typically between pH 3-7 and can be introduced under conditions compatible with an allylic alcohol. Preferred protecting groups are silyl ethers of the formula (R 1 ) 3 SiO— wherein R 1 independently are aryl or C1-6 alkyl and include trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, isopropyldimethylsilyl, t-butyldiphenylsilyl, methyldiisopropylsilyl, methyl-t-butylsilyl, tribenzylsilyl and triphenylsilyl ether. Preferred silyl ethers are trimethylsilyl ether and t-butyldimethylsilyl ether. Some substituted methyl ethers may be used and include 2-(trimethylsilyl)-ethoxymethyl ether (SEM ether), tetrahydropyranyl ether (THP ether), tetrahydrothiopyranyl ether, 4-methoxy-tetrahydropyranyl ether, 4-methoxytetrahydrothiopyranyl ether, tetrahydrofuranyl ether and tetrahydrothiofuranyl ether. Some substituted ethyl ethers that may be used as hydroxy protecting groups and include 1-ethoxyethyl ether and t-butyl ether. Preferred hydroxy protecting groups have lower steric demands, such as trimethylsilyl ether and allow for simultaneous protection of the 3β- and 7β-hydroxy groups.
Other procedures to effect step (c) include contacting a suitably protected androst-5-en-17-one-3β,7β-diol with sodium acetylide, lithium acetylide (as its ethylene diamine complex), ethynyl magnesium halide (e.g., chloride or bromide) or ethynyl zinc halide, as for example in U.S. Pat. No. 2,243,887, in diethylether or other ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, 2-methoxyethylether and the like.
One embodiment of Process B uses 3β-acetoxy-androst-5-en-7-one-17,17-ethylenedioxy as the suitably protected androst-5-en-7,17-dione-3β-ol (see Scheme II; herein referred to as Process B, Route 1).
Another embodiment of Process B uses 3β-acetoxy-androst-5-en-7-on-17-oxime as the suitably protected androst-5-en-7,17-dione-3β-ol (see Scheme III; herein referred to as Process B, Route 2)).
The following examples and schemes further illustrate the invention and they are not intended to limit it in any way.
EXAMPLES
Example 1
Synthesis of 3β-trimethylsilyloxy-androst-5-en-17-one (TMS-DHEA): DHEA is combined with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) and saccharin (as catalyst) in acetonitrile. The reaction mixture was heated to reflux for several hours with stirring under a nitrogen atmosphere. Liberated ammonia was purged under slight vacuum. The volume was then reduced by distillation, followed by cooling the mixture and collecting the precipitated product by filtration. The filter cake of TMS-DHEA product was washed with cold acetonitrile and dried with warm nitrogen to a loss on drying (LOD) of not more than 0.5% to provide approximately 90% isolated yield of the title compound.
Example 2
Synthesis of 17α-ethynyl-androst-5-ene-3β,17β-diol: n-Butyl lithium is added slowly to Me 3 Si—C≡CH in THF under a nitrogen atmosphere at approximately 0° C. to produce the lithium acetylide Me 3 Si—C≡C—Li. The temperature was raised to about 20° C., and TMS-DHEA was added as a solution in THF, and stirred for about 3 hours. The reaction was quenched by raising the temperature to about 40° C., followed by the slow addition of methanol. Liberated acetylene is purged under slight vacuum. Concentrated KOH was then slowly added until gas evolution subsides, and the volume was reduced by approximately 50% by vacuum distillation at approximately 45° C. Excess 6 N HCl was slowly added, while maintaining the temperature at approximately 40° C. The reaction mixture was diluted with water and chilled to approximately 5° C. before collecting the product by filtration and washing the filter cake with cold 50/50 methanol water. The product was dried with warm nitrogen to an LOD of not more than to 0.5% to provide approximately 87% isolated yield of the title compound.
Example 3
Synthesis of 17α-ethynyl-3β-acetoxy-androst-5-en-17β-ol: 17α-ethynyl-androst-5-ene-3β,17β-diol was mixed with acetic anhydride, triethylamine, and a catalytic amount of DMAP in THF at refluxing temperature for at least 4 hours. The reaction progress was monitored by HPLC, and allowed to proceed until not more than 1% of the starting material remains. The mixture was then cooled to 30-50° C., and water was added, followed by cooling to approximately 0° C. for 1 hour. The crude product was collected by filtration, washed with cold acetonitrile, and dried with warm nitrogen to an LOD of not more than 5%. Crude product was characterized by HPLC and recrystallized from acetonitrile if the title compound was present in less than 95% peak area purity by HPLC. The recrystallized product was collected by filtration and dried to provide an overall isolated yield of 83% of the title compound.
Example 4
Synthesis of 17α-ethynyl-3β-acetoxy-17β-ol-androst-5-en-7-one: 17α-ethynyl-3β-acetoxy-androst-5-en-17β-ol was combined with t-butyl hydroperoxide and copper (I) iodide in acetonitrile and refluxed for two hours. The reaction was then quenched by cooling to about 50° C. followed by adding a large excess of aqueous sodium thiosulfate solution with stirring for at least 30 minutes. Under these conditions, organic and aqueous phases are not miscible. Agitation was halted to allow phase separation, and the aqueous phase (lower) is drained. The organic phase was extracted twice with aqueous sodium sulfite solution and brine by mixing at about 45° C. for at least 30 minutes, followed by phase separation, and removal of the aqueous phase. The resulting organic phase was concentrated to approximately 25% of the original volume by vacuum distillation at less than 45° C., and then chilled to about 5° C. The crude product, 17α-ethynyl-3β-acetoxyl-androst-5-en-7-one-17β-ol, was collected by filtration. The filtered cake was washed with cold acetonitrile/water and dried with warm nitrogen to an LOD of not more than 1.0%. The crude product was recrystallized twice by dissolving in N-methyl-pyrrolidinone (NMP) at approximately 90° C., followed by cooling to 0° C. for approximately one hour. The title compound was collected by filtration for an isolated overall yield of approximately 30%.
Example 5
Synthesis of 17α-ethynyl-androst-5-ene-3β,7β,17β-triol: 17α-ethynyl-3β-acetoxy-androst-5-en-7-one-17β-ol was reduced with NaBH 4 in THF/methanol in the presence of CeCl 3 at approximately 0° C. for about 2 hours. The reaction progress was monitored by HPLC. The reaction was quenched by slow addition of dilute HCl with liberated hydrogen removed under slight vacuum. Methyl tert-butyl ether (MTBE) was added and the reaction mixture washed twice with brine, discarding the aqueous phases. The 3β-acetoxy group from the crude product was removed by addition of methanolic KOH to the organic phase at approximately 0° C. for about 2 hours, with reaction progress monitored by HPLC. After completion, the reaction mixture was neutralized with acetic acid, and approximately one-half of the reaction volume was removed by vacuum distillation at less than 45° C. Approximately two-thirds of the original reaction mixture volume was added as isopropanol (IPA), and the volume was subsequently reduced to approximately one-fourth the original volume by vacuum distillation at less than 45° C. The residue mixture was cooled to 0° C., and the crude 17α-ethynyl-androst-5-ene-3β,7β,17β-triol was collected by filtration, washed with cold IPA, and dried with warm nitrogen.
Example 6
Recrystallization of 17α-ethynyl-androst-5-ene-3β,7β,17β-triol from Process A: Crude 17α-ethynyl-androst-5-ene-3β,7β,17β-triol from Example 5 was dissolved in refluxing methanol/water (˜10/1). Methanol was removed by vacuum distillation while stirring, and replaced with sufficient water to maintain suspension of the crystallized product. The suspension is cooled to approximately 5° C. with stirring, and the product was recovered by filtration. The filtered cake was washed with water and dried under vacuum to less than 0.5% water to provide the title compound in approximately 69% isolated yield.
Example 7
Synthesis of 3β-acetoxy-androst-5-ene-17,17-ethylenedioxy: A 300 L reactor was charged with 36 kg of triethylorthoformate, 20 kg of 3β-acetoxy-5-androsten-17-one, 12.6 kg of ethylene glycol and 400 g of p-toluenesulfonic acid. The mixture was heated to reflux under nitrogen until the reaction was complete (about 2-3 hours). The mixture was then cooled to 60° C. and 16 kg of anhydrous ethanol and 400 ml of pyridine were added. The resulting solution was transferred to a container and refrigerated overnight. The solids that formed were filtered and washed with 80 kg of 50% ethanol and dried at 40-50° C. to afford 18.5-21.0 kg (81.5-92.5%) of the title compound.
Example 8
Synthesis of 3β-acetoxy-androst-5-en-7-one-17,17-ethylenedioxy: A 500 L reactor was charged with 200 kg ethyl acetate and 25 kg of 3β-acetoxy-androst-5-en-17,17-ethylenedioxy. The mixture was stirred for 30 minutes whereupon 55 kg of 70% t-butyl peroxide and 9 kg of sodium bicarbonate were added. The reaction mixture was then cooled to 0° C. and 116 kg of 13% sodium perchlorate (aq.) was added over 10 hours so that a reaction temperature below 5° C. and pH between 7.5 and 8.5 were maintained. After the reaction was complete, the organic layer was separated and the aqueous phase was extracted with ethyl acetate (35 kg×2). The combined organic phase was combined with a solution 33 kg of sodium sulfite in 167 kg of water, and the resulting mixture was stirred at 40° C. for 3 hours. The organic phase was washed with 50 kg of brine and concentrated to 55-60 kg whereupon 50 kg of methanol was added. After refrigeration overnight, a white solid was formed that was filtered and washed with 10 kg of methanol, and dried at 40-50° C. to yield 7.1-7.8 kg (27.4-30.1%) of the title compound.
Example 9
Synthesis of 3β-acetoxy-androst-5-ene-17,17-ethylenedioxy-7β-ol. A 500 L reactor was charged with 48 kg of THF, 10 kg of 3β-acetoxy-androst-5-en-7-one-17,17-ethylenedioxy and a solution of 9.6 kg CeCl 3 .7H 2 O in 95 kg methanol. This mixture was cooled to 0° C. whereupon 2.0 kg of NaBH 4 was added in batches over 3 hours in order to maintain the temperature below 5° C. After stirring for 30 more minutes, 28 kg of acetone was added slowly in order to maintain the temperature below 5° C., with stirring continued for another 30 minutes. To the mixture was added 240 kg water with stirring continued for 1 hour. The organic solvents were removed under vacuum and the residue was extracted with ethyl acetate (100 kg+50 kg). The combined organic phase was washed with brine. Solvent was then removed to provide 8.6-8.9 kg (85.1-88.1%) of the title compound.
Example 10
Synthesis of 3β-acetoxy-androst-5-en-17-one-7β-ol: A 500 L reactor was charged with 315 kg of acetone and 18 kg of 3β-acetoxy-androst-5-en-17,17-ethylenedioxy-7β-ol. The mixture was cooled to 5° C. and 2.34 kg of p-toluenesulfonic acid was added slowly to maintain the temperature below 10° C. After stirring the mixture at 8-15° C. for 36-48 hours, 3.0 kg of sodium bicarbonate was added with stirring continued for 1 hour. Acetone was removed under vacuum, and to the residue was added 100 kg of water. The mixture was placed in a refrigerator overnight to give a white precipitate which was filtered to provide 33 kg (wet) of the title compound.
Example 11
Synthesis of androst-5-en-17-one-3β,7β-diol: A 500 L reactor was charged 230 kg methanol, 33 kg (wet) 3β-acetoxy-7β-hydroxy-5-androsten-17-one, 108 kg water and 15 kg Na 2 CO 3 . The mixture was heated to reflux for 3 hours. Methanol was removed under vacuum whereupon 250 kg of water was added to the residue. The mixture was put in refrigerator overnight to give a precipitate. The solids were collected by filtration, then washed with water and dried at 40-50° C. to yield 9.5-10.5 kg (67.9-75.0%) of the title compound as a white solid.
Example 12
Purification of androst-5-en-17-one-3β,7β-diol: A 500 L reactor was charged with 20 kg crude 3β,7β-dihydroxyandrost-5-en-17-one and 200 kg methanol and heated until all the solid dissolved. The solution was filtered while hot and after the filtrate cooled a white crystalline solid formed. The solids were collected by filtration, washed with small amount of methanol and dried at 40-50° C. The solid was then refluxed in 50 kg of ethyl acetate for 20 minutes. After cooling the solid was filtered and dried at 40-50° C. under vacuum to provide 15.2 kg (76%) of purified title compound.
Example 13
Synthesis of 3β,7β-bis-(trimethylsiloxy)-5-androsten-17-one: A mixture of 14.87 Kg of androst-5-en-17-one-3β,7β-diol, 23.8 Kg HMDS and 0.7 Kg saccharin catalyst in 100 L acetonitrile was heated to reflux for 8 hours with stirring under a nitrogen atmosphere. Liberated ammonia was purged under slight vacuum. The reaction volume was then reduced by distillation to collect 30 L of distillate (requires about 2 h). The reaction volume was further reduced to half of the original reaction volume by distillation under reduced pressure (700 mmHg), which requires about 2 h of heating at 50° C. The resulting uniform thick slurry is cooled to 5° C. (requires about 3 h), with additional acetonitrile added to maintain a minimum mixing volume, and held at that temperature for 1. The precipitated product was collected by filtration and dried at 45-50° C. under vacuum (29 mmHg) to a loss on drying (LOD) of not more than 1% (requires 20 h) to provide 16 Kg (81% yield) of the title compound (95% purity).
Example 14
Synthesis of 17α-ethynyl-5-androstene-3β,7β,17β-triol: To 11.02 Kg TMS-acetylene in 56.5 L tetrahydrofuran (THF) at −27° C. under a nitrogen atmosphere was added 8.51 L 10M n-BuLi. The n-butyl lithium was added very slowly to maintain a temperature at −7 to −27° C. (requires about 2 h) and the resulting reaction was stirred 10 min. at approximately 0° C. to produce TMS-lithium-acetylide. To the TMS-lithium-acetylide solution was added a solution of 25.41 Kg of 3β,7β-bis-(trimethylsiloxy)-5-androsten-17-one in 95.3 L THF filtered through a 25 μm filter while allowing the reaction temperature to rise to 20-25° C. After addition was completed, the reaction temperature was increased to 40-45° C. To quench the reactor contents, 31.8 L of methanol was added over a period of about 1 h followed by 3.81 Kg KOH in 18.4 L of water giving a final reactor temperature of 50° C. Liberated acetylene is purged under slight vacuum. The reactor contents were then concentrated by distillation at 80° C. for 1 h then under vacuum (175 mmHg) at about 70° C. (with an initial temperature of 25° C. to avoid bumping) to half of the original pot volume. The residue was cooled to about 10° C. and 35.0 Kg of deionized water was added, followed by 16.4 Kg 12N HCl while maintaining a pot temperature of about 10° C. and giving a final pH of 1. Additional 26.0 kg deionized water was added and the resulting mixture was stirred at about 5° C. for 1 h. The resulting slurry was filtered and washed with 75/25 mixture of methanol/water (16.9 L methanol, 5.6 L water). The collected solids were dried under vacuum (28 in Hg) at 45° C. for 12 h for a loss on drying of no more than 0.5% to provide 9.6 Kg of the title compound (83% yield).
Example 15
Recrystallization of 17α-ethynyl-5-androstene-3β,7β,17β-triol: Crude 9.6 Kg 17α-ethynyl-5-androstene-3β,7β,17β-triol prepared in Example 14 was dissolved in refluxing 50/50 methanol/water (4.2 Kg methanol and 5.4 Kg water). To the solution was added 33.4 Kg methanol followed by 37.6 Kg of THF. The mixture was heated to reflux and stirring was continued until all solids have dissolved, whereupon 99.8 Kg of deionized water was added while maintaining a reactor temperature of 60-75° C. The mixture was cooled to 0-5° C. over a period of 2 h and maintain at that temperature for 1 h while stirring was continued. The solids were recovered by filtration, washed with 9.6 Kg cold 50/50 methanol water and dried under vacuum (28 in Hg) at 50° C. for 8 h to provide 8.2 Kg of 17α-ethynyl-5-androstene-3β,7β,17β-triol. This first recrystallization is used to remove trace colored impurities from the initial product. A second recrystallization was conducted by heating the solid from the first recrystallization in ˜10:1 methanol:water (145.8 Kg methanol and 18.2 Kg of water) to 80° C. until all the solids have dissolved. The solution at 55-60° C. was filtered through a 25 μm filter to remove particulate impurities, whereupon 2.5 Kg of methanol at 55-60° C. (used to rinse the reactor) was added. Vacuum distillation at 125 mmHg at 70° C. was conducted until 0.9 to 1.2 times the volume of methanol that was added to the reactor was collected as distillate with water added as necessary to permit stirring (about 120-160 Kg water added). Final reaction volume was 200-225 L. The reactor mixture was cooled to 0-5° C. and maintained at that temperature for 1 h. The resulting slurry was filtered and the filter cake rinsed with 10 Kg deionized water and dried under vacuum (28 in Hg) at 50° C. for 12 h to a residual water content of less than 0.5%. This isolation procedure was used to reduce the THF content in the final product. The yield was 8.0 Kg of recrystallized title compound (83% yield).
Example 16
Synthesis of 3β-acetoxy-androst-5-en-7-on-17-oxime: 3(3-Acetoxy-androst-5-en-7,17-dione (45 g, 130 mmol) was dissolved in 800 mL methanol, 200 mL dichloromethane and 14.5 g Et 3 N (144 mmol). To the solution at RT was added a solution of 10 g of hydroxylamine hydrochloride dissolved in 200 mL methanol. After stirring overnight, 200 mL of water was added followed by removal of volatile organics by evaporation under reduced pressure. To the resulting residue was added an additional 1 L of water to give a while solid that was filtered and washed well with water. Obtained was 45 g of crude title oxime in 95% purity by 1 H-NMR, which was used in the next step without further purification.
Example 17
Synthesis of 3β-acetoxy-androst-5-en-17-oxime-7β-ol: To a solution of 44 g of 3β-acetoxy-androst-5-en-7-on-17-oxime (100 mol %) in 800 mL methanol and 200 mL tetrahydrofuran was added 50 g of cerium chloride heptahydrate (110 mol %) in 20 mL of methanol. The resulting mixture was stirred until the solids were completely dissolved. To the solution cooled to about −5° C. was added 7 g sodium borohydride over 30 min. After stirring an additional 1.5 h at −5° C., the reaction mixture was quenched with acetone (100 mL) and then allowed to warm to room temperature over a 30 min. period. The quenched reaction mixture was concentrated under vacuum to remove volatile organics. To the residue was added 800 mL of water followed by extraction with ethyl acetate (3×500 mL). The combined organic extracts were washed with brine, dried over Na 2 SO 4 , then concentrated to provide 42 g of the title compound as a white foam, which was used in the next step without further purification.
Example 18
3β-acetoxy-androst-5-en-17-one-7β-ol: To a solution of 42 g of 3β-acetoxy-androst-5-en-17-oxime-7β-ol (100 mol %) in 200 mL of ethanol was added 100 mL of water followed by 80 g (400 mol %) of sodium dithionite. The reaction was heated at 55° C. and stirred 16 h. After cooling, the reaction was concentrated under reduced pressure. The residue was diluted with 100 mL of water, and the resulting solid was collected by filtration and redissolved in 1 L dichloromethane. To the DCM solution was added 1 g activated carbon. After stirring overnight the mixture was filtered, and the resulting filtrate was washed with water, dried and concentrated to provide 25 g of crude product. Recrystallization from ethyl acetate gave 22 g of the title compound.
Example 19
Estrogen receptor binding assay: A suitable example system is an estrogen receptor-kit manufactured by PanVera for ERβ, which contains recombinant estrogen receptor 13 ligand, FLUORMONE™ ES2 (ES2), a fluorescently labeled estrogen ligand, and appropriate buffer. The system was used in a fluorescence polarization competition assay in which a test article, such as a preparation of Compound 1 or a positive control displaces ES2 from its binding site. When bound to ERβ, ES2 tumbles slowly and has a high fluorescence polarization value. Unbound ES2 tumbles quickly and displays a low fluorescence polarization value. The change in polarization value in the presence of test compound then determines relative binding affinity of that test compound for ERβ as expressed by its IC 50 , which is the concentration of test compound that results in half-maximum shift in polarization. From IC 50 , K i was calculated using the Cheng-Prusoff equation [ Biochem. Pharmacol. 22: 3099-3108, (1973)]: K i =IC 50 /(1+D/K d ) where D is the concentration of ES2 and K d is the dissociation constant for binding of ES2 to ERβ (K d =4±2 nM).
The competition assay was conducted according to the manufacturer's protocol (Lit. No. L0712, Rev. 10/03). Assay reagents used were bacculovirus expressed, full length human ERβ 4.5 pmol/μL in 50 mM Bis-Tris Propane (pH=9), 400 mM KCl, 2 mM DTT, 1 mM EDTA, 10% glycerol, ES2 400 nM in methanol and E2 screening buffer consisting of 100 mM potassium phosphate (pH=7.4), 100 μg/mL BGG, 0.02% NaN 3 . The ES2-ERβ complex was formed with 20 μL 20 nM ERβ (0.020 pmol/μL) and 20 μL 2 nM ES2 (0.002 pmol/μL). Positive control (estrogen) solution was prepared using 20 μL of a 1.0 mM stock solution in DMSO and 80 μL DMSO. In a first dilution, 50 μL of this solution is added to 50 μL of DMSO, which is followed by dilutions in 2-fold increments, to provide for a 14 point dilution curve. In a second dilution, to 4 μL of each DMSO solution from the first dilution is added 400 μL of ES2 screening buffer. To 20 μL of test compound, serially diluted in the manner described immediately above, in a 384 well black flat bottom microtiter plate, was added 20 μL of the ES2-ERβ complex (0.5% final DMSO concentration) followed by incubation in the dark at 20-30° C. for 1-4 h. Test compound was treated similarly except the starting concentration was 10 mM. Fluorescence polarization values are obtained using 485 nm excitation and 530 nm emission interference filters. Binding assay for ERα was conducted as for ERβ except bacculovirus expressed, full length human 2.8 pmol/μL ERα was used as reagent with the ERα-ES2 complex formed from 20 μL 30 nM (0.030 pmol/μL) and 20 μL 2 nM ES2 (0.002 pmol/μL).
Example 20
AR, GR and PR receptor binding assays. The AR competition assay was conducted according to the manufacturer's protocol (Lit. No. L0844, Rev. 05/02) in the manner described for ERβ with the following exceptions. Reagents used were recombinant rat androgen receptor ligand binding domain tagged with His and GST [AR-LBD (His-GST)] 0.38 pmol/μL in buffer containing protein stabilizing agents and glycerol (pH=7.5), 200 nM FLUORMONE™ AL Green, which is a fluorescently labeled androgen ligand, in 20 mM Tris, 90% methanol and AR screening buffer containing stabilizing agents and glycerol (pH=7.5) with 2 μL of 1 mM DTT added per mL screening buffer (AR screening buffer 2 mM in added DTT) was used as the reagents. The AL Green-AR complex was formed with 20 μL 50 nM AR (0.050 pmol/μL) and 20 μL 2 nM AL Green (0.002 pmol/μL). K i was calculated using, for the dissociation constant for binding of the fluorophore to receptor, K d =20±10 nM.
The PR competition assay was conducted according to the manufacturer's protocol (Lit. No. L0503, Rev. 06/03) in the manner described for ERβ with the following exceptions. Reagents used were recombinant human progesterone receptor ligand binding domain tagged with GST [PR-LBD (GST)] 3.6 pmol/μL in 50 mM Tris (pH=8.0), 500 mM KCl, 1M urea, 5 mM DTT, 1 mM EDTA and 50% glycerol, 400 nM FLUORMONE™ PL Green, which is a fluorescently labeled progesterone ligand, in 20 mM Tris 90% methanol (pH=6.8) and PR screening buffer containing protein stabilizing agents and glycerol (pH=7.4) with 4 μL of 1 mM DTT added per mL screening buffer (PR screening buffer 4 mM in added DTT). The PL Green-PR complex was formed with 20 μL 80 nM PR (0.080 pmol/μL) and 20 μL 4 nM PL Green (0.004 pmol/μL). K i was calculated using, for the dissociation constant for binding of the fluorophore to receptor, K d =40 nM.
The GR competition assay was conducted according to the manufacturer's protocol (Lit. No. L0304, Rev. 12/01) in the manner described for ERβ with the following exceptions. Reagents used were recombinant full length human glucocorticoid receptor 0.240 pmol/μL in 10 mM phosphate buffer (pH=7.4), 200 mM Na 2 MoO 4 , 0.1 mM EDTA, 5 mM DTT and 10% glycerol, 200 nM FLUORMONE™ GS1, which is a fluorescently labeled glucocorticoid ligand, in 75% methanol, and GR screening buffer containing 100 mM potassium phosphate (pH=7.4), 200 mM Na 2 MoO 4 , 1 mM EDTA, 20% DMSO with 5 μL of 1 mM DTT per mL screening buffer added (GR screening buffer 5 mM in added DTT), 1 mM GR stabilizing peptide, which is a co-activator related peptide [see Chang, C.Y. Mol. Cell. Biol. 19: 8226-36 (1999)] in 10 mM phosphate buffer (pH=7.4) and 1 M DTT in water were used as the reagents. To 2.5 mL of the GR screening buffer is added 2.5 mL GR stabilizing peptide solution and 125 μL of 1 M DTT to form the GR stabilizing peptide-glucocorticoid receptor complex. Order of addition to the microtiter plate was 20 μL test compound in 1% DMSO, 10 μL of 16 nM GR (0.016 pmol/μL) and finally 10 μL of 4 nM GS1, followed by incubation in the dark at 20-30° C. for 4 h (total experiment time should not exceed 7 h). K i was calculated using, for the dissociation constant for binding of the fluorophore to receptor, K d =0.3±0.1 nM.
Example 21
Impurity profiling of 17α-ethynyl-5-androstene-3β,7β,17β-triol (Compound 1) preparations.
Process A: HPLC conditions for Impurity profiling of Compound 1 preparations form Process B are give in Table 1.
TABLE 1
HPLC Conditions for Impurity Profiling of Compound 1
Preparations form Process A
Waters XTERA ™ RP18, 3.5 μm,
Column
4.6 mm (ID) × 150 mm (L)
Mobile Phase A
100% Deionized water (degassed)
Mobile Phase B
100% Acetonitrile (degassed)
Column
30° C.
Temperature
Detection
210
nm
Wavelength
Mobile Phase
90% Mobile Phase A; 10% Mobile Phase B
(initial)
Flow Rate (initial)
1.0
mL/min
Pump Gradient
Program
Time (min)
% A
% B
Flow rate
0.00
90.0
10.0
1.00
40.0
20.0
80.0
1.00
43.00
20.0
80.0
1.00
43.01
90.0
10.0
1.00
50.00 (end)
90.0
10.0
1.00
Injection Volume
10
μL
Run Time
50
minutes
TABLE 2
Impurities in example preparation of Compound 1 prepared according to
Process A, Route 1 before recrystallization
Compound
RRT*
Peak Area %
Unknown
0.63
0.59
Androst-5-en-17-one-3β,7β-diol
0.87
0.12
17α-ethynyl-androst-5-ene-3β,7β,17β-triol
1.00
96.58
(Compound 1)
17α-ethynyl-androst-5-ene-3β,7α,17β-triol
1.04
0.99
17α-ethenyl-androst-5-ene-3β,7β,17β-triol
1.09
0.93
17α-ethynyl-androst-5-en-7-one-3β,17β-diol
1.16
0.06
Unknown
1.47
0.04
Unknown
1.60
0.06
17α-ethynyl-androst-5-ene-3β,17β-diol
1.75
0.63
*RRT-relative retention time (approximate) referenced to Compound 1 (i.e., RRT of Compound 1 arbitrarily set to 1.00)
TABLE 3
Impurities identified in example preparation of Compound 1
prepared according to Process A, Route 1 after recrystallization
Compound
RRT*
Peak Area %
Unknown
0.55
0.13
Androst-5-ene-3β,7β,17β-triol
0.87
0.06
17α-ethynyl-androst-5-ene-3β,7β,17β-triol
1.00
97.67
(Compound 1)
17α-ethynyl-androst-5-ene-3β,7α,17β-triol
1.05
0.72
17α-ethenyl-androst-5-ene-3β,7β,17β-triol
1.09
0.65
17α-ethynyl-androst-5-en-7-one-3β,17β-diol
1.16
0.05
Unknown
1.60
0.05
17α-ethynyl-3β-acetoxy-androst-5-ene-17β-diol
1.72
0.05**
17α-ethynyl-androst-5-ene-3β,17β-diol
1.75
0.61**
*RRT-relative retention time (approximate) referenced to Compound 1 (i.e., RRT of Compound 1 arbitrarily set to 1.00)
**Impurities with determined binding capacity to estrogen receptors (either directly or from the product derived after ester hydrolysis)
Process B: HPLC conditions for Impurity profiling of Compound 1 preparations form Process B are identical to those of Table 1.
TABLE 4
Impurities identified in example preparation of Compound 1 prepared
according to Process B, Route 1 before recrystallization
Compound
RRT
Peak Area %
androst-5-en-17-one-3β,7β-diol
0.94
0.80
17α-ethynyl-androst-5-ene-3β,7β,17β-triol
1.00
98.30
(Compound 1)
17α-ethynyl-androst-5-ene-3β,7α,17β-triol
1.02
0.26
17α-ethynyl-androst-5-en-7-one-3β,17β-diol
1.06
0.08
3β-acetoxy-androst-5-en-17-one-7β-ol
1.24
0.10
DHEA
1.27
0.03
3β-acetoxy-androst-5-en-17-one
1.46
0.09
3β-acetoxy-17-ethylenedioxy-androst-5-ene
1.50
0.12
3β,7β-bis-(trimethsilyloxy)-androst-5-en-17-one
1.68
0.21
*RRT-relative retention time (approximate) referenced to Compound 1 (i.e., RRT of Compound 1 arbitrarily set to 1.00)
Embodiments of the invention include a process for preparation of a 17α-alkynyl-androst-5-ene-3β,7β,17β-triol essentially free of steroid side-product lacking an oxygen substituent at position 7 comprising the steps of (a) contacting a suitably protected dehydroepiandrosterone with an oxidizing agent to directly introduce the ═O (ketone) functional group at position 7; (b) contacting a suitably protected androst-5-en-7,17-dione-3β-ol with a reducing agent to convert the ═O (ketone) functional group at position 7 to hydroxyl predominately in the β-configuration; and (c) contacting an optionally protected alkynyl anion with suitably protected androst-5-en-17-one-3β,7β-diol to introduce an alkynyl substituent at position 17 predominately in the α-configuration by addition of the alkynyl anion to the ═O (ketone) functional group at position 17, wherein the suitably protected androst-5-en-7,17-dione-3β-ol has the structure
wherein R 1 is —H, C 1-6 alkyl, C 3-6 cycloalkyl, optionally substituted aryl or optionally substituted heteroaryl and R 2 is —H, C 1-6 alkyl or aryl.
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The invention relates to processes for preparing 17-alkynyl-7-hydroxy-steroids, such as 17-Ethynyl-10R,13S-dimethyl 2,3,4,7,8R,9S,10,11,12,13,14S,15,16,17-hexadecahydro-1H-cyclopenta[a]phenanthrene-3R,7R,17S-triol (also referred to as 17α-ethynyl-androst-5-ene-3β,7β,17β-triol), that are essentially free of process impurities having binding activity at nuclear estrogen receptors.
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BACKGROUND OF THE INVENTION
The present invention relates generally to tools used in subterranean wells and, in a preferred embodiment thereof, more particularly provides a slurry delivery apparatus for use in formation fracturing operations.
Oftentimes, a potentially productive geological formation beneath the earth's surface contains a sufficient volume of valuable fluids, such as hydrocarbons, but also has a very low permeability. "Permeability" is a term used to describe that quality of a geological formation which enables fluids to move about in the formation. All potentially productive formations have pores, a quality described using the term "porosity", within which the valuable fluids are contained. If, however, the pores are not interconnected, the fluids cannot move about and, thus, cannot be brought to the earth's surface.
When such a formation having very low permeability, but a sufficient quantity of valuable fluids in its pores, is desired to be produced, it becomes necessary to artificially increase the formarion's permeability. This is typically accomplished by "fracturing" the formation, a practice which is well known in the art and for which purpose many methods have been conceived. Basically, fracturing is achieved by applying sufficient pressure to the formation to cause the formation to crack or fracture, hence the name. The desired result being that the cracks interconnect the formarion's pores and allow the valuable fluids to be brought out of the formation and to the surface.
A conventional method of fracturing a formation begins with drilling a subterranean well into the formation and cementing a protective tubular casing within the well. The casing is then perforated to provide fluid communication between the formation and the interior of the casing which extends to the surface. A packer is set in the casing to isolate the formation from the rest of the wellbore, and hydraulic pressure is applied to the formation via tubing which extends from the packer to pumps on the surface.
The pumps apply the hydraulic pressure by pumping fracturing fluid down the tubing, through the packer, into the wellbore below the packer, through the perforations, and finally, into the formation. The pressure is increased until the desired quality and quantity of cracks is achieved and maintained. Much research has gone into discerning the precise amount and rate of fracturing fluid and hydraulic pressure to apply to the formation to achieve the desired quality and quantity of cracks.
The fracturing fluid's composition is far from a simple matter itself. Modern fracturing fluids may include sophisticated manmade proppants suspended in gels. "Proppant" is the term used to describe material in the fracturing fluid which enters the formation cracks once formed and while the hydraulic pressure is still being applied (that is, while the cracks are still being held open by the hydraulic pressure), and acts to prop the cracks open. When the hydraulic pressure is removed, the proppant keeps the cracks from closing completely. The proppant thus helps to maintain the artificial permeability of the formation after the fracturing job is over. Fracturing fluid containing suspended proppant is also called a slurry.
A proppant may be nothing more than a very fine sand, or it may be a material specifically engineered for the job of holding formation cracks open. Whatever its composition, the proppant must be very hard and strong to withstand the forces trying to close the formation cracks. These qualities also make the proppant a very good abrasive. It is not uncommon for holes to be formed in the protective casing, tubing, pumps, and any other equipment through which a slurry is pumped.
Particularly susceptible to abrasion wear from pumped slurry is any piece of equipment in which the slurry must make a sudden or significant change in direction. The slurry, being governed by the laws of physics, including the principles of inertia, tends to maintain its velocity and direction of flow, and resists any change thereof. An object in the flowpath of the slurry which tends to change the velocity or direction of the slurry's flow will soon be worn away as the proppant in the slurry incessantly impinges upon the object.
Of particular concern in this regard is the piece of equipment attached to the tubing extending below the packer which takes the slurry as it is pumped down the tubing and redirects it radially outward so that it exits the tubing and enters the formation through the perforations. That piece of equipment is called a crossover. Assuming, for purposes of convenience, that the tubing extends vertically through the wellbore, and that the formation is generally horizontal, the crossover must change the direction of the slurry by ninety degrees. Because of this significant change of direction, few pieces of equipment (with the notable exception of the pumps) must withstand as much potential abrasive wear as the crossover.
In addition, the crossover is frequently called upon to do several other tasks while the slurry is being pumped through it. For example, the crossover typically contains longitudinal circulation ports through which fracturing fluids that are not received into the formation after exiting the crossover are transmitted back to the surface. Space limitations in the wellbore dictate that the circulation ports are not far removed from the flowpath of the slurry through the crossover. If the crossover is worn away such that the slurry flowpath achieves fluid communication with the circulation ports in the crossover, the fracturing job must cease. Once stopped, the frac job cannot be recommenced or completed. Hence, it is very important that the crossover does not fail while the job is in process. If the frac job is not halted after the crossover fails, the slurry will enter the circulation ports in the crossover and travel back to the surface without delivering the proppant to the formation.
For the above reasons and others, the crossover has commonly been considered a disposable piece of equipment, usable for only one fracturing job, or worse, less than one fracturing job. Even when it survives a fracturing job, it is usually sufficiently worn that no further use may be made of it. This is unfortunate because the crossover is also typically one of the most expensive pieces of equipment used in a fracturing job due to its high machining and material costs.
Further, customers are now demanding fracturing jobs with high flow rates, high pressures, higher quantities, and higher density proppants. All of these increase wear on the crossover and thereby increase the likelihood of crossover failure during the fracturing job.
Attempts have been made to provide a solution for these problems. One involves making the crossover out of extremely hard and abrasion wear resistant materials. This has proven to reduce the rate of abrasion wear of the crossover. It is, however, enormously expensive to make an entire crossover out of a sufficiently wear resistant material. No economic advantage is actually achieved by this solution over the disposable crossover made of less wear resistant, but much less expensive, materials.
Another proposed solution is to utilize surface treatment of less expensive alloy steels to achieve a wear resistant crossover surface. Methods such as carburizing, nitriding, etc., which produce a high surface hardness do indeed slow the abrasion wear rate of the crossover at less expense than using exotic materials. However, as soon as the hardened surface layer has been breached, the crossover begins to wear away rapidly. For this reason, surface-hardened crossovers are also not sufficiently durable for the newer high flow, high pressure fracturing jobs. The extra expense of surface-hardening a disposable crossover makes this solution uneconomical as well.
Another area of concern in regard to abrasion wear during fracturing jobs is the protective casing lining the wellbore. Since the crossover typically directs the slurry flow radially outward, the casing is directly in the altered slurry flowpath. Unintended, misplaced holes in the casing are to be avoided, since it is the casing which provides the only conduit extending to the surface through which all other conduits and equipment must pass.
From the foregoing, it can be seen that it would be quite desirable to provide a slurry delivery apparatus which does not have the economic disadvantages of the solutions enumerated above, but which allows repeated use thereof. It would also be desirable to provide a slurry delivery apparatus which minimizes the abrasive wear of the casing during fracturing operations. It is accordingly an object of the present invention to provide such a slurry delivery apparatus and associated methods of using same.
SUMMARY OF THE INVENTION
In carrying out the principles of the present invention, in accordance with an embodiment thereof, an abrasive slurry delivery apparatus and method of using same are provided, which apparatus and method are specially adapted for utilization in formation fracturing operations in subterranean wellbores.
In broad terms, an abrasive slurry delivery apparatus is provided which includes a first tubular structure having an internal flow passage through which a pressurized, abrasive slurry material may be axially flowed in a downstream direction, and an axial portion having a side wall section with an outlet opening therein through which an abrasive slurry material may be outwardly discharged from the internal flow passage, the outlet opening being circumscribed by a peripheral edge portion of the side wall section, and protective means for shielding the peripheral edge portion of the side wall section from abrasive slurry material being discharged outwardly through the outlet opening, the protective means being disposed within the axial portion of the first tubular structure and having a peripheral edge portion that inwardly overlaps the peripheral edge portion of the side wall section and inwardly blocks a peripheral portion of the outlet opening.
An abrasive slurry delivery apparatus operatively positionable in a subterranean wellbore is also provided, the apparatus including a first tubular structure having an internal flow passage through which a pressurized, abrasive slurry material may be axially flowed in a downstream direction, the first tubular structure having an axial portion with a side wall section thereon, first opening means, associated with the first tubular structure side wall section and operative to discharge abrasive slurry material from the internal flow passage outwardly from the first tubular structure, a second tubular structure coaxially and outwardly circumscribing the axial portion of the first tubular structure and forming therewith an annular flow passage that circumscribes the axial portion, the second tubular structure having a side wall section spaced apart from the first opening means in the downstream direction, and second opening means formed in the second tubular structure side wall section, the annular flow passage and the second opening means cooperating to cause abrasive slurry being outwardly discharged from the first opening means to flow in a downstream direction through the annular flow passage before being discharged outwardly through the second opening means.
Also provided is an abrasive slurry delivery apparatus operatively positionable in a subterranean wellbore, including a first tubular structure having an internal flow passage through which a pressurized, abrasive slurry material may be axially flowed in a downstream direction, and an axial portion having a side wall section with a circumferentially spaced plurality of axially elongated first outlet slots disposed therein and through which an abrasive slurry material may be outwardly discharged from the internal flow passage, each of the first outlet slots having upstream and downstream ends and being circumscribed by a peripheral edge portion of the side wall section, a tubular protective sleeve coaxially and replaceably supported in the axial portion of the first tubular structure and having a circumferentially spaced plurality of axially elongated second outlet slots disposed therein and generally aligned with the first outlet slots, the second outlet slots being smaller than the first outlet slots and being bounded by side wall peripheral edge portions that inwardly overlap the peripheral edge portions of the first tubular structure side wall section, whereby the side wall peripheral edge portions of the tubular protective sleeve inwardly shield the peripheral edge portions of the first tubular structure side wall section from impingement by abrasive slurry material being discharged through the first outlet slots.
For use in conjunction with an abrasive slurry delivery structure having a first tubular structure with an internal passage through which an abrasive slurry may be axially flowed in a downstream direction, and side wall outlet opening means bounded by a peripheral side wall edge portion and outwardly through which abrasive slurry material from the internal passage may be discharged, a method of inhibiting slurry erosion of the peripheral side wall edge portion is provided, the method including the steps of providing a replaceable protective member having a peripheral edge portion, and removably positioning the protective member within the interior of the first tubular structure in a manner such that the peripheral edge portion of the protective member shields the peripheral side wall edge portion of the first tubular structure outlet opening means from abrasive slurry material being forced outwardly therethrough and is subjected to slurry abrasion in place of the peripheral side wall edge portion of the first tubular structure outlet opening means.
A method of delivering abrasive slurry material to the interior of a subterranean wellbore is also provided, the method including the steps of positioning in the wellbore a slurry delivery assembly having a first tubular structure having an internal passage through which an abrasive slurry material may be axially forced in a downstream direction, the first tubular structure having first side wall opening means communicating with the internal passage and through which pressurized abrasive slurry material may be outwardly discharged from the internal passage, and a second tubular structure coaxially and outwardly circumscribing the first tubular structure and forming therearound an annular flow passage, the second tubular structure having second side wall opening means positioned downstream from the first side wall opening means, and forcing a pressurized abrasive slurry sequentially through the internal passage in the downstream direction, outwardly through the first side wall opening means into the annular flow passage, axially through the annular flow passage in the downstream direction, and then outwardly through the second side wall outlet means.
The disclosed slurry delivery apparatus and method of using same permit fracturing operations to be performed more economically and with less damage to equipment disposed within a wellbore and the wellbore casing, as well as at high flow rates, high pressures, high quantities, and high proppant densities, without failure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cross-sectional view of a slurry delivery apparatus having a crossover, a tubular protective sleeve, and a tubular sacrificial insert therein embodying principles of the present invention;
FIG. 2 is an enlarged scale cross-sectional view of the crossover of the slurry delivery apparatus, taken along line 2--2 of FIG. 1;
FIG. 3 is an enlarged scale cross-sectional view of the crossover of the slurry delivery apparatus, taken along line 3--3 of FIG. 2;
FIG. 4A is a partially cross-sectional view of the slurry delivery apparatus having a solid sacrificial insert therein;
FIG. 4B is an elevational view of a portion of an alternative solid sacrificial insert for use in the slurry delivery apparatus of FIG. 4A;
FIG. 5 is an enlarged scale cross-sectional view of another tubular protective sleeve for use in the slurry delivery apparatus;
FIG. 6 is a partially cross-sectional view of the slurry delivery apparatus having the tubular protective sleeve of FIG. 5 operatively installed therein;
FIG. 7 is a partially cross-sectional view of the slurry delivery apparatus having the somewhat modified tubular protective sleeve of FIG. 5 and the tubular sacrificial insert of FIG. 1 operatively installed therein;
FIG. 8 is a cross-sectional view of the slurry delivery apparatus of FIG. 6, further having a casing protective flow sub;
FIG. 9 is an enlarged cross-sectional view of the slurry delivery apparatus taken along line 9--9 of FIG. 8; and
FIG. 10 is a highly schematicized partially cross-sectional view of the slurry delivery apparatus having another casing protective flow sub and operatively disposed within a portion of protective casing.
DETAILED DESCRIPTION
Illustrated in FIG. 1 is an abrasive slurry delivery apparatus 10 which embodies principles of the present invention. In the following detailed description of the apparatus 10 representatively illustrated in FIG. 1 and subsequent figures described hereinbelow, directional terms such as "upper", "lower", "upward", "downward", etc. will be used in relation to the apparatus 10 as it is depicted in the figures. It is to be understood that the apparatus 10 may be utilized in vertical, horizontal, inverted, or inclined orientations without deviating from the principles of the present invention.
Apparatus 10, as representatively illustrated in FIG. 1, is specially adapted for use within a tool string known to those skilled in the art as a service tool string (not shown), which is suspended from tubing extending to the earth's surface, the tubing being longitudinally disposed within protective casing in a subterranean wellbore (see FIG. 10). The service tool string is typically inserted through a packer (not shown) during a fracturing job. A pressurized, abrasive slurry is then pumped through the tubing and into the service tool string. Tubular upper connector 12 and lower connector 14 permit interconnection of the apparatus 10 into the service tool string. Accordingly, upper portion 16 of upper connector 12 is connected to the service tool string above the apparatus 10, and lower portion 18 of lower connector 14 is connected to the remainder of the service tool string extending below the apparatus.
Axial flow passage 20 extends longitudinally (i.e., axially) downward from the upper portion 16 of upper connector 12, axially through the upper connector, and into a generally tubular crossover 22. The axial flow passage 20 terminates at upper radially reduced portion 24 of generally cylindrical plug 26. Plug 26 is threadedly installed into lower portion 28 of crossover 22 and secured with a pair of set screws 29 (only one of which is visible in FIG. 1). Sealing engagement between the plug 26 and the lower portion 28 of crossover 22 is provided by seal 30 disposed in circumferential groove 32 externally formed on the plug.
Radially displaced, longitudinally extending, circulation flow passage 34 extends downwardly from upper portion 16, through the upper connector 12, longitudinally through the crossover 22 in a manner that will be described more fully hereinbelow, through the lower connector 14, and to lower portion 18. When operatively installed in a wellbore 36, the circulation flow passage 34 in the apparatus 10 is sealingly isolated from the wellbore external to the apparatus by seal 38 disposed in circumferential groove internally formed on the upper connector 12, and by seal 42 disposed in circumferential groove 44 internally formed on the lower connector 14. The circulation flow passage 34 is sealingly isolated from coaxial flow passage 20 in the apparatus 10 by seal 30, and by a pair of seals 46, each disposed in one of a pair of circumferential grooves 48 externally formed on an upper portion 50 of the crossover 22 which extends coaxially into the upper connector 12.
Annular antifriction seal rings 52 are disposed in longitudinally spaced apart external annular recesses 54 formed on upper portion 16 of upper connector 12, between upper connector 12 and crossover 22, and between crossover 22 and lower connector 14. The antifriction seal rings 52 ease insertion and movement of the apparatus 10 within the packer and other equipment into which the apparatus 10 may be longitudinally disposed, as well as providing an effective seal therebetween.
Upper portion 50 of crossover 22 is threadedly attached to upper connector 12, and lower portion 28 of the crossover is threadedly attached to lower connector 14.
Four longitudinally extending circumferentially spaced apart slotted outlet openings or exit ports 56 (three of which are visible in FIG. 1), having external radially extending and circumferentially sloping surfaces 57 formed thereon, provide fluid communication between the axial flow passage 20 and the wellbore 36. It is through these exit ports 56 that a slurry must pass in its transition from longitudinal flow in the axial flow passage 20 to radial flow into the wellbore 36. Because of the substantial change of direction from longitudinal flow to radial flow of the slurry through the exit ports 56, the exit ports are particularly susceptible to abrasion wear from proppant contained in the slurry.
In order to protect the exit ports 56 against abrasion wear, a tubular protective sleeve 58 is coaxially disposed within the crossover 22. The protective sleeve 58 is made of a suitably hard and tough abrasion resistant material, such as tungsten carbide, or is made of a material, such as alloy steel, which has been hardened. If made of an alloy steel, the protective sleeve 58 is preferably through-hardened by a process such as case carburizing or nitriding. Other materials and hardening methods may be employed for the protective sleeve 58 without deviating from the principles of the present invention. Tests performed by the applicants indicate that the protective sleeve 58 is preferably made of tungsten carbide.
The protective sleeve 58 is secured into the crossover 22 by drive pin 60 which extends laterally through the protective sleeve and the upper portion 24 of the plug 26. Outer diameter 62 of protective sleeve 58 is only slightly smaller than inner diameter 64 of crossover 22 to prevent the slurry from flowing between the protective sleeve and the crossover. Alternatively, the protective sleeve 58 outer diameter 62 may be slightly larger than the crossover 22 inner diameter 64 such that a press fit or shrink fit is obtained between them.
Upper portion 66 of protective sleeve 58 extends axially upward past the exit ports 56 in the crossover 22, thereby completely internally overlapping that portion of the crossover 22 in which the exit ports 56 are located. Internal longitudinally extending and radially sloping transition surface 68 formed in the upper portion 66 of protective sleeve 58 provides a smooth transition between the inner diameter 64 in the upper portion 50 of the crossover 22 and radially reduced inner diameter 70 of the protective sleeve 58. Note that transition surface 68 extends radially opposite and longitudinally across upper end surfaces 72 of exit ports 56.
Four longitudinally extending and circumferentially spaced slotted outlet openings or flow ports 74 (three of which are visible in FIG. 1) formed in the protective sleeve 58 are circumferentially aligned with the exit ports 56 in the crossover 22. Flow ports 74 are each slightly smaller in length and width than exit ports 56. Thus, flow ports 74 do not permit direct impingement of the slurry on the crossover 22 as it flows radially from the axial flow passage 20 and into the wellbore 36.
Coaxially disposed within the protective sleeve 58 is a tubular sacrificial insert 76, the purpose of which is described more fully hereinbelow. The insert 76 is secured to the upper portion 24 of the plug 26 radially intermediate the plug and the protective sleeve 58. The insert 76 extends longitudinally upward from the plug 26 to a location somewhat downward from transition surface 68 of the protective sleeve 58.
An upwardly opening interior hollow cylindrical volume within the insert 76 above the upper portion 24 of the plug 26 forms a slurry well 78. An internal longitudinally extending and radially sloped transition surface 80 formed in an upper portion 82 of the insert 76 smooths the transition between the inner diameter 70 of the protective sleeve 58 to inner diameter 84 of the insert. As the slurry flows longitudinally downward through the coaxial flow passage 20 into the crossover 22, the slurry will enter the well 78 through its upwardly facing open upper portion 82 and quickly fill the well. Thereafter, the downwardly flowing slurry will directly impinge on the portion of the slurry which has filled the well 78, effectively preventing the slurry from abrading any portion of the crossover 22, protective sleeve 58, or insert 76 due to direct longitudinal impingement by the slurry.
However, as the slurry flow changes direction from longitudinal to radial near the upper portion 82 of the insert 76, abrasion from the slurry flow will gradually wear away the insert. This wearing away of the insert 76 is intended, and the material of which the insert is made is selected to regulate the rate at which the insert wears away. For most applications, the insert 76 is preferably made of brass. The insert 76 may also be made of a more easily abraided material such as aluminum, or a less easily abraided material such as mild steel, to regulate its wear rate without deviating from the principles of the present invention. Preferably, the material of which the insert 76 is made should be selected such that the insert wears longitudinally downward, gradually exposing more of the protective sleeve 58 to the radially directed flow of the slurry, such that the flow ports 74 of the protective sleeve 58 are not permitted to wear circumferentially outward sufficiently far to expose the exit ports 56 of the crossover 22 to the radially directed flow of the slurry.
Through extensive testing, the applicants have determined that the flow ports 74 of the protective sleeve 58 wear at a greater rate at a portion of the flow ports 74 exposed to the radially directed slurry flow which is most longitudinally downward. Thus, in the apparatus 10 as representatively illustrated in FIG. 1, portions 86 of the protective sleeve 58 will have the greatest rate of wear. This is because portions 86 are the portions of the protective sleeve 58 exposed to the radially directed slurry flow which are most longitudinally downward disposed.
Testing has also revealed that with longitudinally extending and circumferentially spaced apart slotted ports such as the flow ports 74 in the protective sleeve 58, the high wear rate portions 86 extend longitudinally approximately 1.5 inches. For this reason, upper edge 88 of the insert 76 is longitudinally spaced downward from the transition surface 68 on the protective sleeve 58 approximately 1.5 inches, thereby preventing excessive wear of the transition surface 68 (where radial thickness of the protective sleeve 58 is minimal) and upper portion 66 of the protective sleeve. Note that the longitudinal extent of high wear rate portions 86 may vary depending on factors such as slurry flow rate and flow port 74 width and number of flow ports. The longitudinal distance between the upper edge 88 of the insert 76 and the transitional surface 68 of the protective sleeve B8 may be varied without deviating from the principles of the present invention.
It may now be fully appreciated that the insert 76 acts to effectively "spread" the circumferential wear of the flow ports 74 longitudinally downward as the insert 76 wears longitudinally downward within the protective sleeve 58. This is due to the fact that as the insert 76 wears longitudinally downward a gradually increasingly downward portion of the flow ports 74 is exposed to the radially directed slurry flow. In other words, high wear rate portions 86 gradually move longitudinally downward as insert 76 wears longitudinally downward. This unique interaction of the insert 76 with the protective sleeve 58 acts to prolong the useful life of the protective sleeve.
Thus has been described a unique configuration of slurry delivery apparatus 10, wherein the crossover 22 is protected from abrasion wear due to slurry flow by an abrasion resistant protective sleeve 58 and sacrificial insert 76, the insert acting to prolong the useful life of the protective sleeve by "spreading" abrasion wear of the protective sleeve over time so that the high wear rate portions 86 of the protective sleeve are continually displaced as the insert is worn away. The insert 76 additionally forms a slurry well 78, effectively minimizing abrasion wear due to longitudinally directed flow of the slurry. The protective sleeve 58 and sacrificial insert 76 are economical to manufacture and easily replaceable in the crossover 22.
Turning now to FIG. 2, a cross-sectional view may be seen of the apparatus 10 representatively illustrated in FIG. 1. The cross-section is taken through line 2--2 of FIG. 1 which extends laterally through the crossover 22. In this view, the manner in which circulation flow passage 34 extends longitudinally through the crossover 22 may be seen.
Eight longitudinally extending and circumferentially spaced circulation ports 90 are disposed radially intermediate the inner diameter 64 of the crossover 22 and outer diameter 92 of the crossover. Two each of the circulation ports 90 are disposed in the crossover 22 circumferentially intermediate each pair of exit ports 56. Note that various quantities and locations may be chosen for the circulation ports 90 and the exit ports 56 in the crossover 22 without deviating from the principles of the present invention.
FIG. 2 also illustrates the necessity for preventing abrasion wear of the crossover 22. It may be clearly seen that if exit ports 56 are allowed to wear appreciably circumferentially outward, the exit ports 56 will eventually be in fluid communication with the circulation ports 90. It may also be clearly seen in FIG. 2 that flow ports 74 in protective sleeve 58, being somewhat smaller in width than the exit ports 56, act to protect the exit ports 56 from abrasion wear due to radially outwardly directed flow of the slurry.
Note that in this view protective sleeve 58 and insert 76 each completely internally overlap the inner diameter 64 of the crossover 22. Thus, the crossover 22 is not only protected against circumferentially outward wear of its exit ports 56, it is also protected against radially outward wear of its inner diameter 64.
Turning now to FIG. 3, a cross-sectional view of the crossover 22, taken laterally along line 3--3 of FIG. 2 may be seen. For illustrative clarity, only the crossover 22 is shown in FIG. 3 and details of the exit ports 56 are not shown. FIG. 3 further illustrates the manner in which the circulation ports 90 are formed in the crossover 22.
Illustrated in FIG. 4A is the slurry delivery apparatus 10 of FIG. 1, having an alternate substantially solid and generally cylindrical sacrificial insert 94 in place of the tubular insert 76. Note that, since insert 94 is substantially solid, there is no slurry well 78 therein. Lack of the slurry well 78, which acts to minimize abrasion wear due to longitudinally and downwardly directed slurry flow, is at least partially compensated for in insert 94 by its substantially greater amount of material which must be worn away.
An upper portion 96 of insert 94 has an upwardly facing spherical surface 98 formed thereon. Spherical surface 98 acts to direct the longitudinally downwardly directed slurry flow radially outward through the flow ports 74 of the protective sleeve 58.
Insert 94 is preferably made of a relatively harder and tougher material as compared to the material of which insert 76 is made to achieve a comparable wear rate. Insert 94 material selection depends on variables such as slurry flow rate, flow port 74 width and area, protective sleeve 58 material and wear rate, etc. Alternatively, insert 94 may be made of a material having a relatively soft core and relatively hard outer surface so that as the relatively soft core is worn away a slurry well is thereby formed in its place. It is to be understood that the material and any method of hardening used to make the insert 94 may be varied without departing from the principles of the present invention.
Illustrated in FIG. 4B is an upper portion 100 of a substantially solid and generally cylindrical sacrificial insert 102 which may be used alternatively in place of the insert 94 of FIG. 4A. A conically shaped upwardly protruding surface 104 formed on the upper portion 100 acts to direct the longitudinally downwardly directed slurry flow radially outward through the flow ports 74 of the protective sleeve 58. Thus, it is clearly seen that variously shaped upper portions of a substantially solid generally cylindrical sacrificial insert may be utilized without departing from the principles of the present invention.
FIG. 5 shows an alternative protective sleeve 106 for use in place of the protective sleeve 58 of FIG. 1. Due to a unique configuration thereof, protective sleeve 106 may be utilized in the slurry delivery apparatus 10 without a sacrificial insert disposed therein. The protective sleeve 106 representatively illustrated in FIG. 5 is specially configured for use without a sacrificial insert, although a sacrificial insert may be used with the protective sleeve without departing from the principles of the present invention.
A portion 108 of the protective sleeve 106 has four longitudinally extending and circumferentially spaced columns 110 composed of a series of axially spaced and variously shaped outlet openings or apertures 112 (only three of such columns of apertures being visible in FIG. 5). The columns 110 are aligned so that, when the protective sleeve 106 is operatively installed in the crossover 22, apertures 112 are disposed longitudinally and circumferentially within the exit ports 56 (see FIG. 6).
Lower portion 114 of the protective sleeve 106 is secured to upper portion 24 of the plug 26 by drive pin 60 which extends laterally through holes 116 (see FIG. 6). Lower portion 114 is secured to apertured portion 108 at interface 118 by a method such as welding. Lower portion 114 includes a portion 120 having a radially reduced inner diameter to compensate for the lack of a sacrificial insert.
Apertured portion 108 is preferably made of a hard abrasion resistant material such as tungsten carbide, although other suitable materials may be employed without departing from the principles of the present invention. Lower portion 114, however, may be made of less costly and less abrasion resistant material than apertured portion 108 for purposes of economy of manufacture of the protective sleeve 106. It is to be understood that apertured portion 108 and lower portion 114 may be made of the same material without departing from the principles of the present invention, in which case there would be no need to separately make each of them and secure them together at interface 118.
Through extensive testing, applicants have found that the variously shaped apertures 112 may be configured to "spread" the circumferential abrasion wear of the protective sleeve 106 longitudinally. As described hereinabove in relation to the protective sleeve 58 of FIG. 1, the greatest amount of abrasion wear due to radially directed slurry flow through a longitudinally extending slotted flow port 74 is typically on the most longitudinally downward portion of the flow port exposed to the radially directed slurry flow. For this reason, on protective sleeve 106 the most longitudinally downward apertures 122 are relatively small in flow area, and the most longitudinally upward apertures 124 are relatively large in flow area. The remainder of the apertures 112, between the farthest upward apertures 124 and the farthest downward apertures 122, are sized such that they are progressively smaller in flow area as they are progressively downwardly disposed on the protective sleeve 106. Note that, in the protective sleeve 106 representatively illustrated in FIG. 5, apertures 126 are similarly sized and apertures 128 are also similarly sized. It is to be understood that various shapes (e.g. slots, circles, ellipses, etc.), dimensions, flow areas, quantity, and spacings of the apertures 112 may be employed without departing from the principles of the present invention.
Apertures 112 formed in protective sleeve 106 are inclined with respect to centerline 130 at an approximate 30 degree included angle. This inclination of the apertures 112 acts to induce a longitudinally downward component to the radially outward directed slurry flow as it passes through the apertures. Benefits to be derived from inducing the longitudinally downward component to the radially outward directed slurry flow will be more clearly understood when the written description relating to FIG. 8 hereinbelow is read and appreciated. Briefly stated, the longitudinally downward component of the slurry flow minimizes direct impingement of the radially directed slurry flow on any equipment disposed radially outward from the exit ports 56 of the crossover 22 (see FIG. 6). It is to be understood that other inclination angles of the apertures 112, may be employed without departing from the principles of the present invention. Additionally, apertures 112 may be sloped tangentially to induce a tangential component to the slurry flow.
An additional benefit derived from the progressively larger flow area of the apertures 112 as the apertures are upwardly disposed in the columns 110, is that slurry flow exiting more upwardly disposed larger flow area apertures influences the slurry flow exiting more downwardly disposed smaller flow area apertures. Therefore, the longitudinally downward component of the slurry flow exiting the more longitudinally upwardly disposed larger flow area apertures aids in inducing the longitudinally downward component to the slurry flow exiting more longitudinally downwardly disposed apertures, thereby enhancing the benefit of the longitudinally downward component of the radially directed slurry flow described hereinabove.
Turning now to FIG. 6, the apparatus 10 is representatively illustrated having the protective sleeve 106 operatively disposed therein. Note that in the embodiment shown in FIG. 6 there is no sacrificial insert disposed within the protective sleeve 106.
Interiorly disposed within the inner diameter 70 of lower portion 114 above the upper portion 24 of plug 26 is a slurry well 132. This slurry well 132 has the same function as the slurry well 78 representatively illustrated in FIG. 1.
The apertures 122,124,126, and 128 are circumferentially and longitudinally aligned with the exit ports 56 of the crossover 22 and the protective sleeve 106 completely interiorly overlaps the inner diameter 64 of the crossover. Note that a portion 134 of the protective sleeve 106 circumferentially disposed between the lowermost apertures 122 and the exit ports 56 is thicker circumferentially than a portion 136 of the protective sleeve circumferentially disposed between the apertures 128 and the exit ports, which is, similarly, thicker circumferentially than portion 138 circumferentially disposed between apertures 124 and 126 and the exit ports. Thus, corresponding to a smaller circumferential width of the apertures 112 more longitudinally downwardly disposed on the protective sleeve 106 are progressively increased circumferential thicknesses available for abrasion wear thereof.
Turning now to FIG. 7, the apparatus 10 is representatively illustrated as having the sacrificial insert 76 of FIG. 1 operatively disposed coaxially within the protective sleeve 106. Lower portion 114 of the protective sleeve 106 has been somewhat modified to accept the insert 76 therewithin by eliminating the radially reduced inner diameter portion 120 so that inner diameter 70 extends longitudinally therethrough. Slurry well 78 is now disposed within the insert 76 in place of slurry well 132 (see FIG. 6) in the protective sleeve 106. With the insert 76 in protective sleeve 106, circumferential abrasion wear of the protective sleeve is "spread" longitudinally downward as the insert is worn away. Thus it may be clearly seen that the protective sleeve 106 may be utilized with sacrificial insert 76, or alternatively, sacrificial inserts 94 (see FIG. 4A), 102 (see FIG. 4B), or others without departing from the principles of the present invention.
FIG. 8 shows the apparatus 10 having a coaxially disposed outer tubular flow sub 140 completely exteriorly overlapping the crossover 22. An annular flow area 142 is thereby formed radially between the outer diameter 92 of the crossover 22 and inner diameter 144 of the flow sub 140. Outer diameter 146 of the flow sub 140 is exposed to the wellbore 36.
An upper portion 148 of the flow sub 140 extends longitudinally upward and is suspended from the packer (not shown). A lower portion 150 of the flow sub 140 is threadedly secured to a lower connector 152 from which further equipment may be attached and suspended.
Extending radially through the flow sub 140 and providing fluid communication from the annular flow area 142 to the wellbore 36 are six circumferentially spaced slurry ports 154 (only two of which are visible in FIG. 8). Slurry ports 154 are inclined with respect to the centerline 130 at a 45 degree included angle in order to induce a longitudinally downward component to the radially directed slurry flow as it exits the slurry ports.
The inclination of the slurry ports 154 acts to reduce direct impingement of the radially directed slurry flow on any equipment external to the flow sub 140. In particular, the inclination of the slurry ports 154 reduces abrasion wear of the casing (see FIG. 10 and accompanying written description). It is to be understood that other inclination angles of the slurry ports 154 with respect to the centerline 130 may be utilized without departing from the principles of the present invention. It is also understood that the slurry ports may be used in a closing sleeve assembly instead of a flow sub.
Slurry ports 154 are longitudinally downwardly displaced relative to the exit ports 56 in the crossover 22 such that the slurry cannot flow directly radially outward from the exit ports 56 and through the slurry ports 154. The slurry must flow, after exiting exit ports 56, at least partially longitudinally downward through annular flow area 142 before it may flow radially outward through slurry ports 154. Thus, the slurry is made to impinge upon the inner diameter 144 of the flow sub 140 after the slurry exits the exit ports 56.
An annular slurry well 156 is longitudinally downwardly disposed relative to the slurry ports 154. Annular slurry well 156 performs a function similar to that performed by slurry well 132 within protective sleeve 106 and by slurry well 78 within sacrificial insert 76 (see FIG. 1). Soon after the slurry flow commences, annular slurry well 156 will fill with the slurry material and provide a fluid "cushion" for the longitudinally downward flow of the slurry in the annular flow area 142.
Flow sub 140 is preferably made of an abrasion resistant material. Since the slurry flow impinges upon the inner diameter 144 of the flow sub 140 before exiting the slurry ports 154, the inner diameter 144 is particularly susceptible to abrasion wear therefrom. For this reason, the flow sub 140 is preferably made of an alloy steel and surfaced hardened at least on the inner diameter 144 by a nitriding or carburizing treatment. It is to be understood that other materials and surface treatments may be utilized without departing from the principles of the present invention.
Turning now to FIG. 9, a cross-sectional view of the apparatus 10 may be seen, taken along the line 9-9 in FIG. 8 which extends laterally through the slurry ports 154 of the flow sub 140. In this view all six of the slurry ports 154 are visible. The slurry ports 154 are equally circumferentially spaced at an angle 158 of 60 degrees. It is to be understood that different quantities and circumferential spacings of the slurry ports 154 may be employed without deviating from the principles of the present invention.
A unique orientation of the slurry ports 154 within the flow sub 140 contributes to a reduction in abrasion wear of the casing external to the flow sub. The inclination of the slurry ports 154 with respect to the centerline 130 has been described hereinabove in the written description accompanying FIG. 8. Additionally, slurry ports 154 are tangentially angled such that a 25 degree included angle 160 is formed between circumferential edges 162 of the slurry ports 154 and radially extending reference lines 164. This tangentially sloped configuration of the slurry ports 154 induces a tangential component to the slurry flow as it exits the slurry ports 154. It is to be understood that other angles of tangential slope may be utilized for the slurry ports 154 without deviating from the principles of the present invention.
In combination with the longitudinally downward component induced by the downward inclination of the slurry ports 154, the tangential component thus induced to the slurry flow produces a downwardly directed helical flowpath of the slurry. This helical flowpath further acts to reduce the abrasion wear of the slurry on any equipment external to the flow sub 140, in particular the casing surrounding the flow sub 140 (see FIG. 10 and accompanying description).
Turning now to FIG. 10, the slurry delivery apparatus 10 may be seen operatively disposed in the wellbore 36 which is lined longitudinally and circumferentially with protective casing 162. In the embodiment representatively illustrated in FIG. 10, flow sub 140 is divided into an upper portion 164 and a lower portion 166.
Flow sub upper portion 164 is specially adapted to contain and position five annular wear rings 168. Upper portion 164 maintains the wear rings 168 longitudinally opposite and exteriorly overlapping the exit ports 56 of the crossover 22. The wear rings 168 are disposed in an annular recess disposed radially inwardly from an enlarged inner diameter 170, and longitudinally between shoulder 172 interiorly formed on upper portion 164 and upper end 174 of lower portion 166. The wear rings 168 are inserted into upper portion 164 before it is threadedly attached to lower portion 166.
Wear rings 168 are preferably made of an abrasion resistant material such as tungsten carbide or a through-hardened alloy steel. The purpose of the wear rings 168 is to prevent abrasion wear of the flow sub 140 inner diameter 144 by preventing impingement of the slurry on the inner diameter 144. It is to be understood that other suitably hard and tough abrasion resistant materials may be utilized without departing from the principles of the present invention.
Flow sub lower portion 166 includes slurry ports 154 and is threadedly attached to lower connector 152. The slurry ports 154 formed in lower portion 166 are inclined to direct the slurry flow tangentially and longitudinally downward as described hereinabove in relation to FIGS. 8 and 9.
Dashed line 176 indicates schematically the slurry flowpath from the time it enters the axial flow passage 20 of the apparatus 10 until it exits the slurry ports 154 of the flow sub lower portion 166. The term "upstream" shall be used hereinbelow to indicate directions toward the entrance of the flowpath 176, and the term "downstream" shall be used to indicate directions toward the exit of the flowpath 176. Thus, upper connector 12 is upstream of lower portion 166. As the apparatus 10 is representatively illustrated in FIG. 10, the downstream direction is longitudinally downward.
Slurry flowpath 176 enters the apparatus 10 through axial flow passage 20 in upper connector 12. The flowpath 176 then enters the crossover 22 and protective sleeve 106. Portion 178 of flowpath 176 is substantially longitudinal and downwardly directed as viewed in FIG. 10. Cushioned by slurry well 132, the flowpath 176 must next change direction in order to radially exit apertures 112 formed in protective sleeve 106.
The 30 degree inclination of apertures 112 induces a longitudinally downward component to the radially outwardly directed slurry flow, resulting in a downwardly inclined flowpath portion 180 of slurry flowpath 176. Downstream of the crossover exit ports 56, flowpath portion 180 enters annular flow area 142 and then impinges upon wear rings 168. Note that this is not a radially orthogonal impingement, but an oblique impingement which is less abrasive to the wear rings 168. Note, also, that the flow sub 140, being positioned longitudinally opposite the exit ports 56, and radially between the exit ports and the casing 162, thereby protects the casing from impingement by the flowpath portion 180.
Since slurry ports 154 are displaced longitudinally downward relative to exit ports 56, the slurry flowpath 176 must then travel longitudinally downward in annular flow area 142 as indicated by flowpath portion 182. Cushioned by slurry well 156, the slurry flowpath 176 must then change direction yet again in order to radially exit slurry ports 154.
As the slurry flowpath 176 travels downstream through slurry ports 154, as indicated by flowpath portion 184, both tangentially directed and longitudinally directed components are induced on the flow, resulting in a helical downwardly directed flow. Thus, downstream of slurry ports 154, flowpath portion 184 is flowing radially outward, tangentially with respect to the wellbore 36, and longitudinally downward.
Flowpath portion 184 impinges upon the casing 162 obliquely, resulting in greatly reduced abrasion wear thereof. Its radial component thereby eliminated, slurry flowpath 176 next travels helically downward as indicated by flowpath portion 186 in the wellbore 36.
The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.
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An abrasive slurry delivery apparatus and associated method of using permit repeated and/or extended use of the apparatus in a subterranean wellbore and reduces abrasive wear of the casing during fracturing operations without requiring the disposal of expensive items of equipment after each fracturing operation. In a preferred embodiment, an abrasive slurry delivery apparatus has a tubular crossover member with an internal flow passage and side wall outlet openings, and a tubular protective member with outlet openings aligned with, but axially and circumferentially smaller than, the crossover outlet openings, coaxially disposed within the crossover.
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BACKGROUND OF THE INVENTION
The invention is concerned with a method of starting a loom after a phase at standstill, in particular after an interruption of the weaving process for the purpose of removal of a fault in the formation of the fabric. The conventional loom comprises a warp let-off motion, a cloth take-up motion, a shed-forming motion and a sley for beating up against the fell of the cloth a weft yarn inserted at any time into a shed.
According to known methods, the fell of the cloth is held at the time in an alternative position at a distance forward from the beat-up position of the sley until a certain beat-up force is reached (Japanese Patent Publication 2-169749). The full beat-up force is, as a rule, reached in the second weaving cycle so that, in the case of the known execution the weft insertion may be effected already after the first weaving cycle executed running idly. In the production of sensitive fabrics, e.g., light-weight fabrics for ladies' outerwear, upon restarting the loom for continuation of the interrupted weaving process, visible points of start may occur in the fabric. It has been found that through the measures known hitherto, in particular in the case of looms of high r.p.m. and correspondingly high weft insertion power, the formation of such starting points cannot reliably be prevented.
The problem underlying the invention is to create a method of starting a loom which is improved in particular in this respect, especially for restarting after the removal of an operative disturbance has been effected, and through which even in the case of looms of high weft insertion power the formation of starting points in the fabric is reliably avoided.
SUMMARY OF THE INVENTION
Applicant's method includes the steps of moving the fell from its operative position, where the sley is positioned to beat the weft yarn, to an alternative position closer to the cloth take-up roller. The weft yarn is then prevented from being fed into the shed and the loom is driven in idling motion so that the shed-forming motion operates in an open position and one of either the warp let-off motion and/or the cloth take-up motion is driven independently of the predetermined weaving program.
The tension of the warp threads and other dynamic operating conditions such as the speed of the loom are monitored with monitoring devices. The loom is driven through a number of weaving cycles (from 2 to 20) until the loom has reached the same warp thread tension and operating conditions as it had prior to stoppage (according to the predetermined weaving program). During these weaving cycles, the fell is slowly moved back to the operational position by changing the speed and direction of the warp beam and the cloth take-up roller. Once the dynamic operating conditions are reestablished, the fell is completely moved to the operational position and the loom is restarted according to the predetermined weaving program.
The energizing of the shed-forming motion and of at least one of the warp let-off and cloth take-up motions independently of the weaving program in the manner in accordance with the invention, allows deliberate influencing of those parameters decisive for uniform formation of the fabric. In particular, the tension of the warp threads which existed before the interruption of the weaving process can be reproduced before the loom has reached its original r.p.m. corresponding with the normal weaving operation and its corresponding dynamic operative state resulting from the cooperation of the individual units. Because of a control signal from an ordinary monitoring device on the loom, which is triggered upon reaching this operative state, the shed-forming motion and the units cooperating with it may be switched over at any time, i.e., after any weaving cycle executed running idly, to the operative weaving program for the initiation of the second phase of the start of the method in accordance with the invention.
Further details follow from the following description of an embodiment of the invention shown diagrammatically in the drawing, in combination with the claims. There is shown in:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates parts of a loom suited to the performance of the method in accordance with the invention, in a simplified side elevation;
FIG. 1a shows an expanded view of the loom set for a form of execution of the method in accordance with the invention;
FIG. 2 shows a shed diagram of the loom during the starting phase of the method in accordance with the invention; and
FIGS. 3 and 4 show corresponding shed diagrams of the loom, each according to a further embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The loom according to FIG. 1 comprises a warp beam 1, a strain beam 2, a shed-forming motion 3 and a sley 4, as well as a breast beam 5, a cloth take-up roller 6, a pressure roller 7 and a cloth beam 8. The warp beam 1 is coupled to a warp let-off motion 10 which may be driven according to the arrows 11 and 11a. In a corresponding way, the cloth take-up roller 6 is coupled to a cloth take-up motion 12 which may be driven according to the arrows 13 and 13a. From the warp beam 1, warp threads 14 are led through the shed-forming motion 3 towards a fell 15 of the cloth and from this as part of a fabric 16 being formed there towards the cloth beam 8 upon which the fabric 16 is being wound. The shed-forming motion 3 comprises a number of healds 17, of which only two are represented in the drawing, and a driving mechanism 18 by which the healds 17 are adjustable at any time for the formation of a shed 20.
Via a weft insertion motion (not shown) coupled to the main loom drive and by a means of weft insertion, e.g., compressed air or as indicated in the drawing a gripper element 21 in the form, e.g. of a belt, a weft yarn 22 is inserted into the shed 20 and in a position 4' of the sley 4 in beat-up, into which it may be swung via a driving mechanism 23, is beaten up against the fell 15 of the cloth and bound in through a succeeding change of shed.
The drives of the warp let-off motion 10 and cloth take-up motion 12 as well as the driving mechanism 18 of the shed-forming motion 3 may be energized each on its own via a common control equipment 24 to correspond with a weaving program. The driving mechanism 23 of the slay 4 may be coupled to the main loom drive or, as shown, may be driven by the control equipment 24. In a known manner, via signal leads 27, 28, 30, 31, 32 indicated in the drawing, the control equipment 24 may be influenced by control signals from numerous monitoring devices by which, e.g. the tension of the warp threads 14 and of the weft yarn 22, as well as the state of the fabric 16 being formed, is sensed. In the drawing, a sensor 25 for monitoring the position of the fell 15 of the cloth and a device 26 for detecting a fault in the fabric 16 being formed, e.g. a faultily inserted weft yarn 22, are shown. The sensor 25 and the device 26 are connected to the control equipment 24 via the signal leads 27 and 28, respectively. The drives of the individual units of the loom are matched to one another via the control equipment 24 and during the normal operation of weaving are controlled to correspond with the predetermined weaving program.
Upon the occurrence of a disturbance in operation, e.g., breakage of a warp or weft yarn or a fault in the formation of the fabric, the loom is stopped by a corresponding control signal from the monitoring element in question. If necessary, e.g., for the removal of a faultily inserted wert yarn, the loom can be reversed by resetting the corresponding units--the warp let-off motion 10, the cloth take-up motion 12 and the shed-forming motion 3--into an operative position determined for the continuation of the interrupted weaving process in accordance with the program.
To restart the loom after the removal of the disturbance, the warp beam 1 and the cloth take-up roller 6 are driven step by step (according to the arrows 11 and 13) to move the fell 15 of the cloth out of the position represented in solid line into an alternative position 15' shown in dotted lines, at a distance from the position 4' of the sley 4 in beat-up. The fell 15 is held in this position during part of a first phase of the start. The position of fell 15 is adjusted by adjusting the speed and direction of the warp beam 1 and/or the cloth take-up roller 6. In this first phase of the start, the main loom drive (not shown) connected operatively to at least one unit of the loom, e.g., the weft insertion motion, may be started first and subsequently at least one of the remaining units at a time--the shed-forming motion 3, the warp let-off motion 10 and the cloth take-up motion 12 as well if necessary as the sley 4--chosen to be switched on one after another. The loom--with the weft yarn feed to the weft insertion means 21 blocked--is accordingly driven during a number, e.g., two to twenty or more weaving cycles running idly, until it has reached its original r.p.m. corresponding with normal weaving operation, the original tension of the warp threads 14 has been reproduced and all of its units are cooperating in the corresponding original rhythm.
During this first phase of the start, the shed-forming motion 3 is driven by the control equipment 24 independently of the preplanned weaving program, in such a way that in each of the weaving cycles executed running idly, the healds 17 adopt a position which corresponds with an open position of the shed 20 in which the last weft yarn 22 correctly inserted is being held securely bound in by the warp threads 14 at the fell 15 of the cloth in the alternative position 15'. Depending upon the kind of fabric to be produced, the healds 17 (corresponding with the representation according to FIG. 2) may be held over all of the weaving cycles of the first phase of the start in the same open shed position or, as shown in FIGS. 3 and 4, be controlled according to a starting program of their own which deviates from the operative weaving program. When the conditions of operation necessary for continuation of the operative weaving process have been fulfilled, upon a corresponding control signal from at least one of the monitoring devices of the loom, e.g., the device 26 associated with the fabric 16 or a monitoring device (not shown) which picks up the tension of the warp threads 14, a reverse turning of the warp beam 1 and/or of the cloth take-up roller 6 is initiated and the fell 15 of the cloth is carried back towards the position 4' of the sley 4 at beat-up.
In the second phase of the start, the shed-forming motion 3, the warp let-off motion 10 and the cloth take-up motion 12 are reenergized to correspond with the operatively predetermined weaving program in the sense of a continuation of the interrupted weaving process. The weft yarn 22 is delivered to the weft insertion means 21, inserted into the shed 20 formed to correspond with the weaving program, beaten up against the fell 15 of the cloth and bound in through a change of shed following in accordance with the program. Due to the method of starting in accordance with the invention, this weft insertion is effected at the same warp yarn tension and under the same dynamic operative conditions as the weft insertion executed before the interruption of the weaving process, formation of a visible starting point in the fabric may in most cases be reliably avoided.
In certain cases, e.g., in the production of extremely thin, nearly transparent fabrics it has been found that, depending upon the yarn material which is to be processed, streaks can occur in the fabric in the case of the weft insertions which follow the first weft insertion after the second phase of the start. This can occur even when all of the previously mentioned units of the loom have reached the operative state necessary to the normal weaving operation and the tensions of the warp threads as well as the r.p.m. of the loom and all the other parameters agree with the corresponding values before the interruption of the weaving process. In order also to prevent these streaks, the fell 15 of the cloth, which has been moved back from the alternative position 15' at the end of the first phase of the start, may be carried and held in a compensating position 15a or 15b which is offset with respect to a desired position corresponding with the position 4' of the sley 4 at beat-up. The compensating position 15a or 15b is offset by an underdimension in the position 15a or a corresponding overdimension respectively in the position 15b.
This dimension of the offset corresponds with a definite fraction, e.g. , 20 to 60%, of the feed of warp and fabric determined by the weaving program and to be executed after each weft insertion. It may in each case, e.g., to correspond with the properties of the material of the warp and/or weft yarn which is to be processed, be influenced by the warp let-off motion 10 and/or the cloth take-up motion 12 or by appropriate energizing of the strain beam 2 and/or breast beam 5. After the first weft insertion executed in the second phase of the start, the fell 15 of the cloth is carried from the compensating position 15a or 15b in a predetermined number of equal partial steps (one to ten or more), in each case before one of the following weft insertions, into a corresponding intermediate position and finally into the desired position.
In this way, the weft density of the fabric 16, determined by the set warp and cloth feed and operatively kept constant, may be varied within the predetermined limits. This type of fell typically arises in the fabric when, at constant weft density, the angles of wrap of the warp threads as they wrap round the weft threads deviate from a desired value set in the case of normal weaving operation. Hence, different angles of wrap of the warp threads wrapping round the weft threads may be compensated and approximated in steps to the operatively desired value of this angle of wrap. The occurrence of a visible point of start in the fabric 16 may accordingly be prevented and an essentially uniform formation of the fabric achieved.
The direction and dimension of the offset necessary at any time in the compensating position 15a or 15b with respect to the beat-up position 4' of the sley 4 may, e.g., upon starting weaving with the loom occupied by the corresponding warp and weft yarn material, be determined through experimentally executed starting processes of the loom, and set to correspond with the result which may be achieved doing so. By corresponding programming of the control equipment 24, the described correction of the position of the fell of the cloth may, e.g., by energizing the strain beam 2 and/or the breast beam 5, be performed at any time automatically.
For the control of the shed-forming motion 3 during the first phase of the start, an independent control unit 24a may be activated during the first phase of the start and switched off before the start of the second phase of the start. The control unit 24a may also be made as a component which may at option, say, for the reequipping of an existing loom, be built into an existing control equipment. Instead of the shed-forming motion 3 with healds 17 as described, another shed-forming motion, e.g., a Jacquard motion, may also be provided.
The shed diagram according to FIG. 2 shows a shed 20a with a weft yarn 22a inserted in a weaving cycle Wa before the interruption of the weaving process. A shed 20b is formed to correspond with the predetermined weaving program for the next weft insertion, with a weft yarn 22b inserted in a weaving cycle Wb. A succeeding shed 20C is formed in accordance with the program, with a weft yarn 22c inserted in a weaving cycle We. Over a number of weaving cycles executed running idly (W1-W5), as well as in the weaving cycle Wb of the second phase of the start, the shed 20b is held in the open position in which the weft yarn 22b is inserted in accordance with the program.
As appears from FIG. 3, the first phase of the start may extend over a number of weaving cycles running idly, in accordance with W1 to W4, with the previously described shed 20b being formed in the weaving cycles W1, W3 and Wb, while in each of the weaving cycles W2 and W4 another shed 20x is formed which does not occur in the operative weaving program, so that the weft yarn 22a is held securely bound in.
According to FIG. 4, the shed 20b may be held in the corresponding open position over a number of weaving cycles running idly (W1, W2 and W3), and combined with the shed 20x formed in the weaving cycle W4 running idly.
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A method of restarting a loom after an interruption in the weaving process. A cloth fell (15) is moved from an operative or beating position (15) to a second position (15') away from a sley (4). The weft yarn is prevented from being fed into a shed (20) and the loom is then driven in a idling motion for a number of weaving cycles. A shed forming motion 3 and at least one of the warp let-off motion 10 and the cloth take-up motion 12 are driven independently of the predetermined weaving program. When the loom has reached its original dynamic operative state and the warp threads are at the original operative tension, the cloth fell is advanced to the beating position of the sley and the loom is restarted according to the predetermined weaving program. This method prevents visible points of start from occurring in the fabric because of the interruption in the weaving process.
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BACKGROUND OF THE INVENTION
The present invention relates to amplifiers such as those employed in AM broadcasting and, more particularly, to such amplifiers including mean for minimizing distortion and noise resulting from variations in the DC power supply.
It is known that noise and/or other variations appearing on the output of a DC power supply connected to the input of an amplifier may result in distortion. The power supply noise is of particular concern in high power amplifiers, such as those found in transmitters conventionally used in commercial AM broadcasting. It is known to employ large capacitors connected across the power supply to reduce low frequency AC supply voltage variations caused by power supply ripple and low frequency transmitter modulation. These power supply variations may well be reduced substantially by connecting a large amount of capacitance across the power supply output. However, such capacitors employed with high power DC power sources are quite large both in volume and in weight. The inclusion of such capacitors is undesirable from the standpoint of cost, size and weight.
It is also known that some AM transmitter circuits employ a low frequency distortion correction circuit that takes a sample of the power supply output and then generates a correction signal that is used to compensate for power supply sag. Such prior art circuits include, for example, the U.S. Pat. Nos. to H. I. Swanson et al., 4,731,731, H. I. Swanson, 4,580,111, and D. H. Covill, 4,605,910. Each of these patents discloses circuitry for minimizing modulation distortion of an amplitude modulated RF carrier signal resulting from variations in the DC power supply. In each case, a feed forward technique is employed in which a sample of the input DC voltage signal is obtained and is combined with the input audio signal to compensate for variations in the magnitude of the DC supply voltage prior to supplying the input audio signal to the amplification stages of the transmitter.
In the prior art discussed immediately above, the AC and DC components of the power supply sample are used for both long term DC supply changes and short term sags such as power supply ripple or low frequency transmitter modulation. In low power transmitters, correction loops typically treated the AC and DC components equally in terms of phase and gain of the signals, since large amounts of supply filter capacitance were practical in most cases. However, with higher power transmitters, such as those exceeding 50 kilowatts, the cost of such filter capacitance prohibits their use for minimizing power supply sag. Moreover, at higher power levels, the transmitters tax the AC main input lines and may possibly cause additional power supply sag with modulation. In view of these factors, it has been found desirable that the AC component of the power supply sample be separated from the DC component so that additional gain and phase correction may be made to the AC component independent of variations in the DC component to achieve optimum low frequency distortion and minimum AM noise.
SUMMARY OF THE INVENTION
It therefore a primary object of the present invention to provide a correction signal wherein the phase and gain of the AC component of the power supply sample may be varied independently of the DC component.
In accordance with the present invention, an amplifier system is provided having improved distortion reduction. This system includes a DC voltage source having AC and DC components. An input signal to be amplified is supplied to an amplifier coupled to a DC voltage source for amplifying the input signal to provide an output signal in accordance therewith. Correction signal circuitry is provided and includes circuitry for separating the AC and DC components and varying the magnitude and phase of the AC component independently of the DC component to provide an adjusted AC component. The DC component and the adjusted AC component are summed together to provide an adjusted correction signal which is then combined with the input signal prior to application of the input signal to the amplifier.
In accordance with another aspect of the present invention, the amplifier system is an RF amplifier system and the amplifier means includes a plurality of actuatable RF power amplifiers each connected to the DC voltage source and each, when actuated, for receiving and amplifying an RF drive signal with each power amplifier having an output circuit for providing an RF output signal. One or more of the RF amplifiers are actuated in dependence upon the magnitude of the input signal. The RF output signals are then additively combined to provide a combined RF output signal. The adjusted correction signal and the input signal are combined prior to actuation of one or more of the RF amplifiers.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the present invention will become more readily apparent from the following description as taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic-block diagram illustration of one application to which the present invention may be applied;
FIG. 2 is a prior art schematic circuit illustration of one of the power amplifiers employed in FIG. 1;
FIG. 2A is a prior art simplified schematic circuit useful in understanding the operation of the circuit shown in FIG. 2;
FIG. 3 is a schematic-block diagram of the correction circuit in accordance with the present invention;
FIG. 4 is a graphical illustration showing phase and amplitude with respect to frequency useful in describing the invention herein;
FIGS. 5A 5B and 5C include waveforms showing the operation of circuitry in accordance with the prior art without the correction circuit of the present invention; and
FIGS. 6A 6B and 6C include waveforms showing the operation resulting with the inclusion of the correction circuitry in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One application of the present invention is in conjunction with the use of RF power amplifiers employed in AM broadcast transmitters. An example of such a transmitter is presented in FIG. 1 and takes the form of a digital amplitude modulator such as that illustrated and described in the aforesaid U.S. Pat. No. 4,580,111, which is assigned to the same assignee as the present invention, the disclosure of which is herein incorporated by reference.
The discussion which follows is directed to an explanation of the operation of the circuitry shown in FIG. 1 followed by a detailed description of a power amplifier as illustrated in FIGS. 2 and 2A herein as background for the discussion of the invention presented with respect to the embodiment illustrated herein in FIG. 3.
Referring now to FIG. 1, the amplitude modulator 10 is illustrated as receiving an input signal from input source 12 which may be the source of an audio signal. Modulator 10 generates an RF carrier signal which is amplitude modulated as a function of the amplitude of the input signal from source 12. The amplitude modulated carrier signal is provided on an output line connected to a load 14, which may take the form of an RF transmitting antenna. A digitizer 16 provides a plurality of digital control signals D1 through DN which have values which vary in accordance with the instantaneous level of the input signal. The control signals are binary signals each having a binary 1 or a binary 0 level. The number of signals having binary 1 or binary 0 levels is dependent upon the instantaneous level of the input signal.
Each of the output control signals D1-DN is supplied to one of a plurality of N RF power amplifiers PA 1 -PA N . The control signals serve to turn associated power amplifiers either on or off. Thus, if the control signal has a binary 1 level, then its associated amplifier is inactive and no signal is provided at its output. However, if the control signal is of a binary 0 level, then the power amplifier is active and an amplified carrier signal is provided at its output. Each power amplifier has an input connected to a single common RF source 20. The RF source 20 serves as the single source of an RF carrier signal which is supplied by way of an RF splitter 22 so that each amplifier PA 1 -PA N receives a signal of like amplitude and phase and frequency. The carrier signal is amplitude modulated in accordance with the control signals D1-DN and the amplitude modulated carrier signals will be of like frequency and phase. These signals are supplied to a combiner circuit 24 comprised of a plurality of transformers T 1 , T 2 , . . ., T N . The secondary windings act as an independent signal source, whereby the signals provided by the various transformers additively combine with one another to produce a combined signal which is supplied to the load 14. This combined signal has the same frequency as the RF signal supplied by the RF source 20, but the amplitude of the combined signal is modulated in accordance with the input signal supplied by the input source 12.
As is conventional in such a system, the RF source 20 includes an RF oscillator 21 having a frequency on the order of 500 to 1600 KHz. This oscillator feeds an RF driver 23, the output of which is supplied to the power amplifiers PA 1 -PA N . The RF driver provides power amplification of the RF signal obtained from oscillator 21 prior to the signal being supplied to the power amplifiers at which modulation also takes place. The RF driver 23 may include several stages of amplification and may be configured similar to the power amplifiers PA 1 -PA N .
FIG. 2 illustrates one form which the power amplifier PA 1 of FIG. 1 may take, the other power amplifiers PA 2 -PA N being similar. The power amplifier illustrated includes four semiconductor amplifier elements 70, 72, 74 and 76 connected in a bridge arrangement across a DC power supply voltage of, for example, 250 volts. The primary winding 44 of the associated transformer 36 is connected across the bridge junctions J 1 and J 2 of the four semiconductor elements.
More particularly, the semiconductor amplifier elements are metal oxide semiconductor, field effect transistors (MOSFETs) having three electrodes, conventionally identified as the gate, drain, and source. The drain-source paths of the transistors 70 and 72, representing their primary current paths, are connected in series across the DC power supply, as are the drain-source current paths of transistors 74 and 76. The primary winding 44 of the corresponding combiner transformer T1 is connected in series with a DC blocking capacitor 78 across the common junctions J 1 and J 2 between transistors 70 and 72 and transistors 74 and 76.
The transistors 70, 72, 74 and 76 effectively operate as switches to connect the two sides of the primary winding 44 to either the DC voltage source or to ground. By proper operation of these transistors, the transformer winding 44 can be connected in either direction across the DC power supply.
This can perhaps be more readily understood by reference to FIG. 2A, which is a simplified illustration of the FIG. 2 circuitry. In FIG. 2A the transistors 70, 72, 74 and 76 are respectively characterized by conventional single pole, single throw switches S 1 , S 2 , S 3 , and S 4 . As shown in FIG. 2A, the switch S 1 is open and the switch S 2 is closed, whereby the common junction J 1 between them is grounded. The switch S 3 is closed and the switch S 4 open, however, whereby the junction J 2 between those switches is connected to the DC supply voltage. Current will therefore pass through the primary winding 44 in the direction indicated by the arrow 80.
When all four switches S 1 -S 4 are thrown to their opposite states, current will pass through the output winding 44 in the opposite direction. Thus, when switches S 1 and S 4 are closed and switches S 2 and S 3 opened, junction J 1 is connected to the DC supply and junction J 2 is connected to ground. In this case the current through the primary winding 44 of the transformer is in a direction opposite to that indicated by arrow 80 of FIG. 2A. An AC signal can thus be applied across the coil 44 by cyclically switching the switches S 1 -S 4 between these two alternate states. If this is done at RF frequencies, then an RF carrier signal results.
Referring back to FIG. 2, the transistor switches 70, 72, 74 and 76 are controlled by signals applied to their gate electrodes. The gate signals for all four transistors are derived from individual secondary transformer windings. This transformer has a toroidal ferrite core with a primary winding 82 and four secondary windings 84, 86, 88 and 90 wound around it. The turns ratio of the transformer is 1:1, whereby the same signal appearing at the primary is applied to each of the circuits connected to the four secondary windings.
Each of the four secondary windings is connected between the gate and source electrodes of an associated one of the MOSFETs 70-76. The secondary 84 is directly connected between the gate MOSFET 70 and junction J 1 , while secondary 88 is similarly directly connected between the gate of MOSFET 74 and junction J 2 . The secondary windings 86 and 90 are in like manner connected between the gate and source electrodes of MOSFETS 72 and 76, however in these cases impedance networks 92 and 94 are connected in series with the coils 86 and 90, respectively. Each impedance network 92, 94 includes a parallel combination of a resistor 96, 98 and capacitor 100, 102. The purpose of these impedance networks will be described hereinafter during the description of the amplifier control circuitry 104.
The primary winding 82 of the toroidal transformer is connected to the output of the RF source 20, which provides a sinusoidal RF driving voltage to the power amplifier Each MOSFET turns "on" when the RF signal applied to its gate is on its positive half cycle and "off" when the applied signal is on its negative half cycle. The MOSFETs therefore cyclically turn on and off at a frequency and phase of the applied RF gate signal. The windings 84 and 90 are connected across MOSFETs 70 and 76 in similar directions whereby the signals appearing at the gates of these transistors are in phase with one another. MOSFETs 70 and 76 therefore turn on and off in unison Windings 86 and 88, on the other hand, are connected across MOSFETs 72 and 74 in a direction opposite to the direction of connection of the windings 84 and 90. The signals applied to the gates of MOSFETs 70 and 76 are therefore 180° out of phase with respect to the signals applied to the gates of transistors 74 and 72. Consequently, when transistors 70 and 76 are "on", transistors 72 and 74 are "off", and vice versa.
Due to the nonlinear transfer characteristics of the MOSFETs 70, 72, 74 and 76, the MOSFETs will abruptly turn on and off in response to the applied sinusoidal signal, rather than linearly following it. The signal applied across the junctions J 1 and J 2 will therefore have essentially a squarewave form, though at the frequency of the applied RF input signal. The load 14 to which the output of the combiner circuit 24 of FIG. 1 is connected will generally be frequency selective, and will select only a fundamental component of this squarewave.
As shown in FIG. 2, the power amplifier PA 1 includes a switching circuit 104 for turning the power amplifier on and off in response to the control signal appearing on the digitizer output line D 1 . The switching circuit 104 includes an NPN bipolar junction transistor 106 having its emitter grounded and its collector connected to the gates of MOSFETs 72 and 76 through corresponding diodes 108 and 110. The base of the transistor 106 is connected to the D 1 output of the digitizer 24 through a base resistor 112. When the control signal applied to the base resistor 112 has a high logic level (i.e., logic "1"), base current is applied to the transistor 106, forcing it into a saturation. The gates of the transistors 72 and 76 are then effectively grounded through the corresponding diodes 108 and 110. This has the effect of clamping the gate signals of these transistors to a ground potential, thereby forcing both of them to remain in an "off" condition. The primary winding 44 is thus effectively disconnected from ground, thereby turning off the power amplifier.
The resistors 96 and 98 in the gate circuits of MOSFETs 72 and 76 limit the DC current through transistor 106 when it is saturated. Were these not included the current through the transistor 106 would be quite high because the windings 86 and 90 act as voltage sources. The capacitors 100 and 102 bypass the resistors, reducing their effect at RF frequencies. A third capacitor 114 is connected between both capacitors 100 and 102. This capacitor improves the turn-on/turn-off characteristics of the amplifier.
When the control signal applied to the base of transistor 106 is at a low logic level (i.e. logic "0"), the transistor 106 is cut off and the operation of the amplifier 26 is substantially as described previously. However, this logic 0 signal is a negative signal and it serves to turn on PNP transistors 95 and 97 through base drive resistors 91 and 93, respectively. When these transistors are turned on forcing them into saturation, they, in turn, rapidly drive the MOSFET switching transistors 72 and 76 into saturation.
The turn on control signal applied to transistors 95 and 97 must be sufficient to drive these transistors into saturation so that the MOSFET switching transistors operate as switches and not resistors which could cause excessive MOSFET dissipation, high stress and potential failure. This turn on or binary "0" signal is a negative DC voltage.
The modulating audio input signal 12 is supplied to an analog processing circuit 33 which adds a DC level to the audio signal and provides this audio plus DC level to a DC regulator 35 which supplies regulated DC voltage to a digitizer 16. The output of the analog processing circuit 33 is also supplied to an analog divider circuit 39 which divides the audio frequency signal by a sample voltage V 1 and which is a sample of the power supply DC voltage V DC . The audio frequency signal divided by the sample voltage V 1 is supplied to an analog-to-digital converter 37. The converter 37 converts the signals into a digital representation thereof and which may be internally decoded to provide a number of control signals D1-DN. The number of the control signals that are supplied by digitizer 16 will vary with the magnitude of the audio signal and DC level received from the audio input. The digitizer supplies either a binary 1 (turn off signal) or binary 0 (turn on signal) to the respective power amplifiers PA 1 -PA N . The operation is otherwise as described hereinbefore.
The sample signal V 1 that is supplied to the divider 39 is illustrated in FIG. 1 as being obtained from a correction circuit 41 having its input taken from the midpoint of a voltage divider made up of series connected resistors 43 and 45. This voltage divider is connected across the output of a suitable power supply circuit such as a three phase rectifier 17 connected across a line voltage source 19. It is conventional with such power supplies to have a capacitor C connected across the power supply with the capacitor having a value on the order of 0.5 farads The DC voltage V DC may be on the order of 230 volts.
The prior art distortion correction circuits identified hereinbefore obtained the sample voltage V 1 directly from the voltage divider and not by way of a correction circuit, such as circuit 41 in FIG. 1. Attention is now directed to a more detailed description of the correction circuit presented with respect to FIG. 3 and the waveforms of FIGS. 4, 5 and 6.
The correction circuit 41 as depicted in FIG. 3 receives a sample voltage from the voltage divider comprised of resistors 43 and 45 with the sample voltage having a value on the order of approximately 10 volts DC. This sample voltage is supplied to a low-pass filter 47 which serves to predominantly pass the DC component of the sample voltage. The sample voltage is also supplied to a phase compensator 49 and then to a high pass filter 51 which removes the DC component and passes only the AC component of the sampled voltage. As will be brought out hereinafter, the AC component is phase changed by the compensator 49 and its gain is changed with an adjustable potentiometer 65 in the high pass filter. The AC and DC components are then summed together in a summing circuit 53 to provide an adjusted correction signal at the output circuit 67 of the summing circuit which is then applied as the correction signal V 1 to the divider 39 described hereinbefore.
The low-pass filter 47 is a 2 Hz active low-pass filter that serves to predominantly pass the DC component of the sample voltage. The filter 47 employs an amplifier 55 having its positive or noninverting input connected to ground by way of a resistor 57. The negative input of the amplifier is connected to the junction of resistors 43 and 45 to obtain the sample voltage therefrom by way of input resistor 59. As is conventional, the low-pass filter includes a resistor 61 and a capacitor 63 connected together in parallel between the output of the amplifier and the negative input This is a first order low-pass filter and with the components employed may exhibit a gain on the order of 0.36 in the pass band.
As is shown in FIG. 3, the phase compensator 49 includes an RF bypass capacitor 200 connected in parallel with a resistor 202 across the resistor 45. Capacitors 204 and 206 are connected together in parallel and extend from the junction of capacitor 200 and resistor 202 and thence in series with a resistor 208 to the high pass filter 51. The capacitors 204 and 206 together with the resistor 208 are the primary components for providing phase change. The phase change caused by the phase compensator 49 is to correct for the change in phase that takes place in the AC component of the power supply voltage V DC between the output of the three phase rectifier 47 and the amplitude modulated output of the transmitter.
The high pass filter 51 is a single order high pass filter and with the components employed exhibits a variable gain in the pass band of 0.13 to 0.45. The three db cutoff frequency for this example is about 2 Hz The filter 51 includes an amplifier 210 having its positive or noninverting input connected to ground by way of a resistor 212. The feedback path between output and the negative input includes potentiometer 65 connected in series with a fixed resistor 214. As the resistance of potentiometer 65 is increased, the gain will increase to increase the magnitude of the AC component passed by the filter 51.
The summing amplifier 53 includes an amplifier 220 having its positive or noninverting input connected to ground by way of a resistor 222. A resistor 224 and a capacitor 226 are connected together in parallel between the output and negative input of the amplifier 220 as is conventional. The output from the summing amplifier is taken at output circuit 67 connected by way of a resistor 228 to the output of amplifier 220. The outputs of filters 47 and 51 are applied through resistors 230 and 232, respectively, to the negative input of amplifier 220 in the summing amplifier circuit 53. The summing amplifier provides unity gain for each of these inputs The resultant output at output circuit 67 is on the order of 3.6 volts DC for the 10 volt input.
Reference is now made to FIG. 4 which shows the phase response and the amplitude response at output circuit 67 in FIG. 3. The phase response is illustrated by curve 300 and the amplitude response is illustrated by curve 302. The phase response curve 300 shows the phase angle in degrees with respect to frequency from 10 Hz to 1 kHz. The amplitude response is given in db over a frequency range from 10 Hz to 1 kHz. This presents test results of an active correction circuit showing phase and amplitude response of the circuit of FIG. 3 that is required to provide optimum performance at 100 kilowatts of operation over a frequency range from 10 Hz to 1 kHz. The phase response curve 300 shows that -50° phase shift is required at 100 Hz to compensate for power supply sag when the power amplifiers are operating at 100 kilowatts. Similarly, the amplitude response curve 302 shows that a 5 db gain is required at 20 Hz to correctly compensate for power supply sag when operating at 100 kilowatts. These adjustments are provided by the circuitry of FIG. 3.
Reference is now made to waveforms in FIGS. 5A, 5B and 5C. The waveform of FIG. 5A represents the RF envelope of the RF output signal taken from transmitter at the load 14 of FIG. 1. FIG. 5B illustrates the AC component of the power supply voltage V DC which shows that a phase shift takes place between the input and the output and this may, for example, be on the order of 10°. If a correction signal is provided in accordance with the prior art referred to hereinabove (which does not include the correction circuit 41) then the correction signal as shown in the waveform of FIG. 5C will be of the same phase as the power supply voltage V DC and, hence, will not result in a proper correction for this phase shift.
The waveforms in FIGS. 6A and 6B correspond with those in FIGS. 5A and 5B. However, the waveform in FIG. 6C represents a correction signal provided in accordance with the present invention by employing the correction circuit 41 of FIG. 3. This provides a phase shift for the correction signal. More specifically, this shows the lagging phase shift in the power supply is phase corrected by the correction circuit of the invention herein to allow the signal to the analog divider 39 to be the proper phase and amplitude for minimum distortion.
Although the invention has been described with respect to a preferred embodiment, it is to be appreciated that various modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
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An amplifier system is disclosed having improved distortion reduction. This system includes a DC voltage source having AC and DC components. An input signal to be amplified is supplied to an amplifier coupled to a DC voltage source for amplifying the input signal to provide an output signal in accordance therewith. Correction signal circuitry is provided including circuitry for separating the AC and DC components and varying the magnitude and phase of the AC component independently of the DC component to provide an adjusted AC component. The DC component and the adjusted AC component are summed together to provide an adjusted correction signal which is then combined with the input signal prior to application of the input signal to the amplifier.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is continuation of and claims priority of U.S. Ser. No. 10/848,877 filed May 19, 2004, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to diagnostic imaging and, more particularly, to a multi-layer direct conversion CT detector capable of providing photon count and/or energy data with improved saturation characteristics.
[0003] Typically, in radiographic imaging systems, an x-ray source emits x-rays toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” may be interchangeably used to describe anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-rays. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image.
[0004] In some computed tomography (CT) imaging systems, the x-ray source and the detector array are rotated about a gantry within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-rays as a beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and a photodiode for receiving the light energy from an adjacent scintillator and producing electrical signals therefrom. Typically, each scintillator of a scintillator array converts x-rays to light energy. Each photodiode detects the light energy and generates a corresponding electrical signal. The outputs of the photodiodes are then transmitted to the data processing system for image reconstruction.
[0005] Conventional CT imaging systems utilize detectors that convert radiographic energy into current signals that are integrated over a time period, then measured and ultimately digitized. A drawback of such detectors is their inability to provide data or feedback as to the number and/or energy of photons detected. That is, conventional CT detectors have a scintillator component and photodiode component wherein the scintillator component illuminates upon reception of radiographic energy and the photodiode detects illumination of the scintillator component and provides an electrical signal as a function of the intensity of illumination. While it is generally recognized that CT imaging would not be a viable diagnostic imaging tool without the advancements achieved with conventional CT detector design, a drawback of these detectors is their inability to provide energy discriminatory data or otherwise count the number and/or measure the energy of photons actually received by a given detector element or pixel. Accordingly, recent detector developments have included the design of an energy discriminating, direct conversion detector that can provide photon counting and/or energy discriminating feedback. In this regard, the detector can be caused to operate in an x-ray counting mode, an energy measurement mode of each x-ray event, or both.
[0006] These energy discriminating, direct conversion detectors are capable of not only x-ray counting, but also providing a measurement of the energy level of each x-ray detected. While a number of materials may be used in the construction of a direct conversion energy discriminating detector, semiconductors have been shown to be one preferred material. A drawback of direct conversion semiconductor detectors, however, is that these types of detectors cannot count at the very high x-ray photon flux rates typically encountered with conventional CT systems. The very high x-ray photon flux rate ultimately leads to detector saturation. That is, these detectors typically saturate at relatively low x-ray flux levels. This saturation can occur at detector locations wherein small subject thickness is interposed between the detector and the radiographic energy source or x-ray tube. It has been shown that these saturated regions correspond to paths of low subject thickness near or outside the width of the subject projected onto the detector fan-arc. In many instances, the subject is more or less circular or elliptical in the effect on attenuation of the x-ray flux and subsequent incident intensity to the detector. In this case, the saturated regions represent two disjointed regions at extremes of the fan-arc. In other less typical, but not rare instances, saturation occurs at other locations and in more than two disjointed regions of the detector. In the case of an elliptical subject, the saturation at the edges of the fan-arc is reduced by the imposition of a bowtie filter between the subject and the x-ray source. Typically, the filter is constructed to match the shape of the subject in such a way as to equalize total attenuation, filter and subject, across the fan-arc. The flux incident to the detector is then relatively uniform across the fan-arc and does not result in saturation. What can be problematic, however, is that the bowtie filter may not be optimum given that a subject population is significantly less than uniform and not exactly elliptical in shape. In such cases, it is possible for one or more disjointed regions of saturation to occur or conversely to over-filter the x-ray flux and create regions of very low flux. Low x-ray flux in the projection will ultimately contribute to noise in the reconstructed image of the subject.
[0007] A number of imaging techniques have been developed to address saturation of any part of the detector. These techniques include maintenance of low x-ray flux across the width of a detector array, for example, by using low tube current or current that is modulated per view. However, this solution leads to increased scanned time. That is, there is a penalty that the acquisition time for the image is increased in proportion to the nominal flux needed to acquire a certain number of x-rays that meet image quality requirements. Other solutions include the implementation of an over-range algorithm that is used to generate replacement data for the saturated data. However, these algorithms may imperfectly replace the saturated data as well as contribute to the complexity of the CT system.
[0008] It would therefore be desirable to design a direct conversion, energy discriminating CT detector that does not saturate at the x-ray photon flux rates typically found in conventional CT systems.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The present invention is directed to a multilayer CT detector that can be made to perform at very high count rates that overcomes the aforementioned drawbacks.
[0010] A CT detector capable of energy discrimination and direct conversion is disclosed. The detector includes multiple layers of semiconductor material of varying thicknesses throughout the detector. In this regard, the detector is constructed so as to be segmented in the x-ray penetration direction to optimize count rate performance as well as avoid saturation.
[0011] The CT detector supports not only x-ray photon counting, but energy measurement or tagging as well. As a result, the present invention supports the acquisition of both anatomical detail as well as tissue characterization information. In this regard, the energy discriminatory information or data may be used to reduce the effects of beam hardening and the like. Further, these detectors support the acquisition of tissue discriminatory data and therefore provide diagnostic information that is indicative of disease or other pathologies. For example, detection of calcium in a plaque in a view is possible. This detector can also be used to detect, measure, and characterize materials that may be injected into a subject such as contrast agents and other specialized materials such as targeting agents. Contrast materials can, for example, include iodine that is injected into the blood stream for better visualization. A method of fabricating such a detector is also disclosed.
[0012] Therefore, in accordance with one aspect of the present invention, a direct conversion CT detector includes multiple direct conversion layers designed to directly convert radiographic energy to electrical signals representative of energy sensitive CT data. The detector also includes an electrical signal collection layer sandwiched between adjacent direct conversion layers.
[0013] In accordance with another aspect, the present invention includes a CT system having a rotatable gantry having a bore centrally disposed therein, a table movable fore and aft through the bore and configured to position a subject for CT data acquisition, and a radiographic energy projection source positioned within the rotatable gantry and configured to project radiographic energy toward the subject. The CT system also includes a detector array disposed within the rotatable gantry and configured to detect radiographic energy projected by the projection source and impinged by the subject. The detector array includes a plurality of detector cells, wherein each cell has a stacked arrangement of semiconductor layers in a direction generally that of energy projection and designed to provide energy sensitive data acquired from the subject in response to receiving radiographic energy.
[0014] According to another aspect, the present invention includes a CT detector having a first means and a second means for directly converting radiographic energy to electrical signals. The detector also has means for receiving electrical signals interstitially positioned between the first means for directly converting and the second means for directly converting.
[0015] Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.
[0017] In the drawings:
[0018] FIG. 1 is a pictorial view of a CT imaging system.
[0019] FIG. 2 is a block schematic diagram of the system illustrated in FIG. 1 .
[0020] FIG. 3 is a perspective view of one embodiment of a CT system detector assembly.
[0021] FIG. 4 is a perspective view of a CT detector.
[0022] FIG. 5 is illustrative of various configurations of the detector in FIG. 4 in a four-slice mode.
[0023] FIG. 6 is a partial perspective view of a two-layer director in accordance with the present invention.
[0024] FIG. 7 is a cross-sectional view of FIG. 6 taken along lines 7 - 7 thereof.
[0025] FIGS. 8-10 illustrate cross-sectional views of direct conversion detectors in accordance with several additional embodiments of the present invention.
[0026] FIG. 11 is a cross-sectional schematic view of that shown in FIG. 10 illustrating signal feedthroughs that are created in another embodiment of the invention.
[0027] FIG. 12 is a pictorial view of a CT system for use with a non-invasive package inspection system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] The operating environment of the present invention is described with respect to a four-slice computed tomography (CT) system. However, it will be appreciated by those skilled in the art that the present invention is equally applicable for use with single-slice or other multi-slice configurations. Moreover, the present invention will be described with respect to the detection and conversion of x-rays. However, one skilled in the art will further appreciate that the present invention is equally applicable for the detection and conversion of other radiographic energy.
[0029] Referring to FIGS. 1 and 2 , a computed tomography (CT) imaging system 10 is shown as including a gantry 12 representative of a “third generation” CT scanner. Gantry 12 has an x-ray source 14 that projects a beam of x-rays 16 toward a detector assembly 18 on the opposite side of the gantry 12 . Detector assembly 18 is formed by a plurality of detectors 20 which together sense the projected x-rays that pass through a medical patient 22 . Each detector 20 produces an electrical signal that represents not only the intensity of an impinging x-ray beam but is also capable of providing photon or x-ray count data, and hence the attenuated beam as it passes through the patient 22 . During a scan to acquire x-ray projection data, gantry 12 and the components mounted thereon rotate about a center of rotation 24 .
[0030] Rotation of gantry 12 and the operation of x-ray source 14 are governed by a control mechanism 26 of CT system 10 . Control mechanism 26 includes an x-ray controller 28 that provides power and timing signals to an x-ray source 14 and a gantry motor controller 30 that controls the rotational speed and position of gantry 12 . A data acquisition system (DAS) 32 in control mechanism 26 review data from detectors 20 and converts the data to digital signals for subsequent processing. An image reconstructor 34 receives sampled and digitized x-ray data from DAS 32 and performs high speed reconstruction. The reconstructed image is applied as an input to a computer 36 which stores the image in a mass storage device 38 .
[0031] Computer 36 also receives commands and scanning parameters from an operator via console 40 that has a keyboard. An associated cathode ray tube display 42 allows the operator to observe the reconstructed image and other data from computer 36 . The operator supplied commands and parameters are used by computer 36 to provide control signals and information to DAS 32 , x-ray controller 28 and gantry motor controller 30 .
[0032] In addition, computer 36 operates a table motor controller 44 which controls a motorized table 46 to position patient 22 and gantry 12 . Particularly, table 46 moves portions of patient 22 through a gantry opening 48 .
[0033] As shown in FIGS. 3 and 4 , detector assembly 18 includes a plurality of detectors 20 , with each detector including a number of detector elements 50 arranged in a cellular array. A collimator (not shown) is positioned to collimate x-rays 16 before such beams impinge upon the detector assembly 18 . In one embodiment, shown in FIG. 3 , detector assembly 18 includes 57 detectors 20 , each detector 20 having an array size of 16×16. As a result, assembly 18 has 16 rows and 912 columns (16×57 detectors) which allows 16 simultaneous slices of data to be collected with each rotation of gantry 12 .
[0034] Switch arrays 54 and 56 , FIG. 4 , are multi-dimensional semiconductor arrays coupled between cellular array 52 and DAS 32 . Switch arrays 54 and 56 include a plurality of field effect transistors (FET) (not shown) arranged as multi-dimensional array and are designed to combine the outputs of multiple cells to minimize the number of data acquisition channels and associated cost. The FET array includes a number of electrical leads connected to each of the respective detector elements 50 and a number of output leads electrically connected to DAS 32 via a flexible electrical interface 58 . Particularly, about one-half of detector element outputs are electrically connected to switch 54 with the other one-half of detector element outputs electrically connected to switch 56 . Each detector 20 is secured to a detector frame 60 , FIG. 3 , by mounting brackets 62 .
[0035] It is contemplated and recognized that for some applications, the count rate limitation of the FET arrays may make them less desirable. In this regard, as will be described, each detection pixel or cell is connected to a channel of electronics.
[0036] Switch arrays 80 and 82 further include a decoder (not shown) that enables, disables, or combines detector element outputs in accordance with a desired number of slices and slice resolutions for each slice. Decoder, in one embodiment, is a decoder chip or a FET controller as known in the art. Decoder includes a plurality of output and control lines coupled to switch arrays 54 and 56 and DAS 32 . In one embodiment defined as a 16 slice mode, decoder enables switch arrays 54 and 56 so that all rows of the detector assembly 18 are activated, resulting in 16 simultaneous slices of data for processing by DAS 32 . Of course, many other slice combinations are possible. For example, decoder may also select from other slice modes, including one, two, and four-slice modes.
[0037] As shown in FIG. 5 , by transmitting the appropriate decoder instructions, switch arrays 54 and 56 can be configured in the four-slice mode so that the data is collected from four slices of one or more rows of detector assembly 18 . Depending upon the specific configuration of switch arrays 54 and 56 , various combinations of detectors 20 can be enabled, disabled, or combined so that the slice thickness may consist of one, two, three, or four rows of detector elements 50 . Additional examples include, a single slice mode including one slice with slices ranging from 1.25 mm thick to 20 mm thick, and a two slice mode including two slices with slices ranging from 1.25 mm thick to 10 mm thick. Additional modes beyond those described are contemplated.
[0038] As described above, each detector 20 is designed to directly convert radiographic energy to electrical signals containing energy discriminatory data. The present invention contemplates a number of configurations for these detectors. Notwithstanding the distinctions between each of these embodiments, each detector does share two common features. One of these features is the multilayer arrangement of semiconductor films or layers. In a preferred embodiment, each semiconductor film is fabricated from Cadmium Zinc Telluride (CZT). However, one skilled in the art will readily recognize that other materials capable of the direct conversion of radiographic energy may be used. The other common feature between the various embodiments is the use of interstitial or intervening metallized films or layers separating the semi-conducting layers. As will be described, these metallized layers are used to apply a voltage across a semiconductor layer as well as collect electrical signals from a semiconductor layer.
[0039] It is generally well known that photon count rate performance of a semiconductor is a function of the square of the thickness of the detector and the radiographic energy deposition process is exponential. The count rate performance for a CZT detector may be defined by:
T TR = L 2 V μ e .
[0040] From this definition, assuming a thickness of L=0.3 cm and an electric field V of 1000 V/cm, and with a μ e of about 1000, a maximum count rate of 1.0 megacounts may be achieved. In other words, the count rate of a CZT semiconductor layer that is 3 mm thick may have a count rate performance in the range of 1.0 megacounts/sec. However, as will be described, constructing a direct conversion semiconductor detector with multiple layers as opposed to a single thicker layer can improve count rate performance.
[0041] Referring now to FIG. 6 , a portion of a two-layered CZT or direct conversion detector 20 a in accordance with one embodiment of the present invention is shown in perspective. Detector 20 a is defined by a first semiconductor layer 62 and a second semiconductor layer 64 . During the fabrication process, each semiconductor layer 62 , 64 is constructed to have a number of electronically pixilated structures or pixels to define a number of detection elements 65 . This electronic pixilation is accomplished by applying a 2D array 67 , 69 of electrical contacts 65 onto a layer 62 , 64 of direct conversion material. Moreover, in a preferred embodiment, this pixilation is defined two-dimensionally across the width and length of each semiconductor layer 62 , 64 .
[0042] Detector 20 a includes a contiguous high voltage electrode 66 , 68 for semiconductor layers 62 , 64 , respectively. Each high voltage electrode 66 , 68 is connected to a power supply (not shown) and is designed to power a respective semiconductor layer during the x-ray or gamma ray detection process. One skilled in the art will appreciate that each high voltage connection layer should be relatively thin so as to reduce the x-ray absorption characteristics of each layer and, in a preferred embodiment, is a few hundred angstroms thick. As will be described in greater detail below, these high voltage electrodes may be affixed to a semiconductor layer through a metallization process.
[0043] Referring now to FIG. 7 , a cross-sectional view of FIG. 6 taken along line 7 - 7 thereof illustrates the relative thickness of each semiconductor layer 62 , 64 . Similar to the high voltage electrode layers 66 , 68 , the 2D arrays 67 , 69 should also be minimally absorbent of radiographic energy. Each array or signal collection layer is designed to provide a mechanism for outputting the electrical signals created by the semiconductor layers to a data acquisition system or other system electronics. One skilled in the art will appreciate that several hundred interconnects (not shown) are used to connect each contact 65 with the CT system electronics.
[0044] In addition, as shown in FIG. 7 , the thickness of the semiconductor layers 62 , 64 is different from one another. In this regard, more x-rays are deposited in semiconductor layer 62 than in semiconductor layer 64 . For example, assuming that semiconductor layer 62 has a thickness of one millimeter (mm) and semiconductor 64 has a thickness of 2 mm, semiconductor layer 62 is expected to absorb about 78% of the x-rays whereas the second semiconductor layer 64 is expected to absorb about 22% of the x-rays. Further, it is expected that the first semiconductor layer 62 is to experience a maximum count rate that is approximately nine times faster than that of a single layer semiconductor 3 mm thick. However, the first semiconductor layer 62 measures only approximately 78% of the total flux thereby providing an 11.5 times increase in effective max count rate performance compared to a single semiconductor layer 3 mm thick. The second semiconductor layer 64 is expected to have a count rate that is 2.25 times faster than that of a single 3 mm thick semiconductor but measures only approximately 22% of the total flux, thereby, providing an equivalent or effective max count rate that is approximately 10.2 times that expected to be experienced with a single layer of semiconductor material 3 mm thick. As a result of the improved count rates of the segmented detector described above relative to a single layer of semiconductor material, detector 20 a may be constructed to provide a tenfold increase in count rate performance.
[0045] The above dimensions are illustrative of the improvement in maximum count rate that may be experienced with a two layer detector. However, it is contemplated that more than two layers may be used to construct a CT detector with improved count rate characteristics. For example, a single 0.43 mm layer is expected to absorb about 54% of x-rays received and, as such, has a maximum count rate of approximately 40 times that of a single layer, 3.0 mm thick semiconductor. However, a 0.43 mm layer absorbs only approximately 54% of the total flux to provide an equivalent or effective max count rate of approximately 92 times that of a single semiconductor layer that is 3 mm thick. Additional layers may be added to provide an overall count rate increase of 9200%.
[0046] Referring now to FIG. 8 , another contemplated design for a CZT or direct conversion detector is shown. In this embodiment, detector 20 b also includes a pair of semiconductor layers 74 , 76 . In contrast to the previously described embodiment, detector 20 b includes a single, common signal collection layer or 2D contact array 78 . This single, yet common array 78 is designed to collect electrical signals from both semiconductor layers 74 , 76 and output those electrical signals to a DAS or other system electronics. In addition, detector 20 b includes a pair of high voltage electrodes 80 , 82 . Each high voltage electrode effectively operates as a cathode whereas the contacts of the 2D array 78 operate as an anode. In this regard, the voltage applied via high voltage connections 80 , 82 creates a circuit through each semiconductor layer to the signal collection contacts array 78 .
[0047] Yet another contemplated embodiment is illustrated in FIG. 9 . As shown in this embodiment, detector 20 c includes four semiconductor layers 84 , 86 , 88 , and 90 . Detector 20 c further includes two electrically conductive lines or paths 92 , 94 that are electrically connected to high voltage electrodes 87 , 89 , 91 as well as collection contact arrays 93 , 95 . Electrically conductive path 92 receives and translates electrical signals from contact arrays 93 , 95 . In this regard, a single data output is provided to the CT system's electronics. Similar to a single signal collection lead, a single high voltage connection 94 is used to power the four semiconductor layers 84 - 90 via electrodes 87 , 89 , 91 . Detector 20 c only requires a single high voltage connection.
[0048] Referring to FIG. 10 , a monolithic embodiment of the present invention is shown. Similar to the embodiment of FIG. 7 , detector 20 d includes four semiconductor layers 96 - 102 . Each semiconductor layer 96 - 102 is connected to a pair of electrically conductive layers. In this regard, one electrically conductive layer is used for application of a voltage whereas the other electrically conductive layer is used for collection of the electrical signals generated by the respective semiconductor layers. To minimize the number of electrically conductive layers, detector 20 d utilizes an alternating electrically conductive layer architecture. That is, every other electrically conductive layer is used for high voltage connection with the other electrically conductive layers used for signal collection. In this regard, electrically conductive layers 104 , 106 , and 108 are used for application of a relatively high voltage whereas layers 110 and 112 include contacts for signal collection. As such, high voltage collection layers 104 and 108 are used to apply a voltage to semiconductor layers 96 and 102 , respectively. High voltage connection layer 106 is used to apply a voltage to semiconductor layers 98 and 100 .
[0049] As described above, in a preferred embodiment, each semiconductor layer is constructed from CZT material. One skilled in the art will appreciate that there are a number of techniques that may be used to construct such a semiconductor. For example, molecular beam epitaxy (MBE) is one method that may be used to grow each thin layer of CZT material. One skilled in the art will appreciate that a number of techniques may be used to metallize the semiconductor layers to provide the electrically conductive connections heretofore described.
[0050] Further, metallization may also be used to provide signal feedthroughs for the collection contacts as illustrated in FIG. 11 . As shown, a single layer of semiconductor material 114 is sandwiched between an array 116 of collection contacts and a high voltage electrode layer 118 . Prior to metallization of the semiconductor layer 114 to form collection contact array 116 and high voltage electrode layer 118 , holes 120 may be etched or otherwise formed in semiconductor 114 . The holes 120 may then be metallized to provide a signal feed path 122 from a respective collection contact 124 . The signal feedthroughs or conductive paths 122 are constructed within holes 120 so as to not be in contact with the near-contiguous high voltage electrode layer 118 . In this regard, signal runs may extend vertically or in the x-ray reception direction throughout the detector to a bus (not shown) designed to translate the electrical signals emitted by the individual collection contacts 124 to the CT system's electronics. As a result, a stacked arrangement of a series of thin stacked layers in the x-ray direction is formed.
[0051] Referring now to FIG. 12 , package/baggage inspection system 126 includes a rotatable gantry 128 having an opening 130 therein through which packages or pieces of baggage may pass. The rotatable gantry 128 houses a high frequency electromagnetic energy source 132 as well as a detector assembly 134 . A conveyor system 136 is also provided and includes a conveyor belt 138 supported by structure 140 to automatically and continuously pass packages or baggage pieces 142 through opening 130 to be scanned. Objects 142 are fed through opening 130 by conveyor belt 138 , imaging data is then acquired, and the conveyor belt 138 removes the packages 142 from opening 130 in a controlled and continuous manner. As a result, postal inspectors, baggage handlers, and other security personnel may non-invasively inspect the contents of packages 142 for explosives, knives, guns, contraband, etc.
[0052] Therefore, a direct conversion CT detector includes multiple direct conversion layers designed to directly convert radiographic energy to electrical signals representative of energy sensitive CT data. The detector also includes an electrical signal collection layer sandwiched between adjacent direct conversion layers.
[0053] The present invention also includes a CT system having a rotatable gantry having a bore centrally disposed therein, a table movable fore and aft through the bore and configured to position a subject for CT data acquisition, and a radiographic energy projection source positioned within the rotatable gantry and configured to project radiographic energy toward the subject. The CT system also includes a detector array disposed within the rotatable gantry and configured to detect radiographic energy projected by the projection source and impinged by the subject. The detector array includes a plurality of detector cells, wherein each cell has a stacked arrangement of semiconductor layers in a direction generally that of energy projection and designed to provide energy sensitive data acquired from the subject in response to receiving radiographic energy.
[0054] The present invention further includes a CT detector having a first means and a second means for directly converting radiographic energy to electrical signals. The detector also has means for receiving electrical signals interstitially positioned between the first means for directly converting and the second means for directly converting.
[0055] The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
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A CT detector capable of energy discrimination and direct conversion is disclosed. The detector includes multiple layers of semiconductor material with the layers having varying thicknesses. The detector is constructed to be segmented in the x-ray penetration direction so as to optimize count rate performance as well as avoid saturation.
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The U.S. Government has rights in this invention pursuant to Contract No. CR-812123-01-0 between the U.S. Environmental Protection Agency and New York University.
BACKGROUND OF THE INVENTION
The present invention is directed to the process for the removal of organic contaminants, in particular polychlorinated biphenyls (PCBs), from soil, sediments and sludges. All organic compounds having physico-chemical characteristics similar to PCBs can be removed by this process.
Contamination of sediments and sludges of various harbors, rivers and lagoons throughout the U.S. with PCBs and other organics is recognized to be a serious environmental problem. Specific PCB contamination sites of particular severity have been identified at Waukegan, IL. and Bedford Harbor, ME., the Hudson river in New York and numerous industrial lagoons. Dredging to decontaminate such harbors/rivers and lagoons is unacceptable until effective disposal/treatment methods for the contaminated sediments become available. The detoxification of such contaminated sediments and sludges at economically acceptable costs presents a serious technological challenge if goals of having no more than 1-5 ppm PCBs in the treated sediments are to be met.
A major problem in the decontamination of soil, sediment and sludges is the high water content often encountered in the environment. This is particularly true if the sediment or sludge has to be dredged from a river basis or a lagoon. Water contents of 80% are not uncommon.
Treatment of PCB contaminated sediments and sludges in an incinerator complying with CFR761.70 is quite energy intensive and costly, if 99.9999 percent destruction and removal efficiencies for the PCBs are to be achieved. Exact costs are difficult to predict because it is uncertain what prices commercial incineration facilities will charge to accept the responsibility of handling such sensitive materials. Current estimates range from $1700 to $2000/m 3 if the cost of disposal of residue from incineration are included. Chemical waste landfill disposal costs incurred when the contaminated sediments or sludges are placed in an authorized chemical waste landfill, are less expensive, but present other difficult problems. There exists therefore a very real need for an alternative process technology which is both technically and economically feasible for the cleanup of these PCB contaminated sediments and sludges.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a process which satisfies the need for cleaning contaminated soil, sediments and sludges and which is both technically and economically feasible.
These and other objects of the present invention are achieved in accordance with the present invention with the process for the decontamination of soil, sediments and sludges contaminated with PCBs and organic compounds having physico-chemical characteristics similar to PCBs, such as pesticides, herbicides, polyhalogenated benzenes, polychlorinated phenols, dioxins, and polynuclear aromatic hydrocarbons which are soluble in acetone or in another low boiling (bp. <100° C.) hydrophilic solvents.
The process in accordance with the present invention is based upon known facts about the properties of PCBs present in soils; sediments and sludges, that is, that the PCBs have a very high partition coefficient between natural sediments and water. The PCB concentration in sediments is on the order of 1000 to 3000 times higher than that in water in the same mixture. The present invention also utilizes the characteristics of particular hydrophilic and hydrophobic solvents, and the application of stripping operations as a final step for isolation and concentration of the contaminants.
The first step of the process takes advantage of the extremely low solubility of PCBs in water and the high affinity for sediment particles. In a typical PCB contaminated sludge or sediment composed primarily of water with, for example, 20% total solids, one could expect virtually all of the PCBs to be associated with the sediment in a water medium. Thus the first processing step is a physical separation of water and solids. This can be accomplished with varying degrees of efficiency using existing equipment. In practice, the solids fraction from this separation will contain on the order of 50% water, but will most likely contain 98%+ of the PCB content. The solid fraction and the liquid fraction from the first step require further treatment, however, the first step has managed to isolate most of the PCBs and reduced the sample size by about 60%. The water fraction requires subsequent treatment, which will be addressed later.
This step of the process is applicable to soil, sediment or sludges having a water content from 20% up to 95%, and will be successful with any organic contaminant, which has a partition coefficient (K) between the solid and the liquid fraction of at least 20, whereby the partition coefficient is defined as the ratio of the contaminant concentration in the solid fraction to that in the liquid fraction.
In the second step of the process, the PCB must disassociate themselves from the solid substrate. To do this a water miscible solvent (hydrophilic) such as acetone, is added in quantities sufficient to break the bond between the PCBs and the solid surface. This is followed by another liquid/solid separation. This description is for one stage of the proposed second step of the process.
The use of a hydrophilic solvent was made possible by the removal of the bulk of the water in the first step. The amount of PCB transferred to the solvent/water mixture depends on the stage efficiency, which in turn depends on the partition coefficient between the solid phase and the leaching solvent and the mass ratio of solvent to solids. For optimal performance the mass ratio of solvent to solids should have a value in the range of 1 to 15, preferably 1 to 10 and most preferably 4 to 7.
Knowing the stage efficiency, one can then predict the number of stages required to perform a particular level of separation, given the original contamination level and the allowable level in the solid effluent. This second step is a multistage counter-current leaching using a hydrophilic solvent, or a mixture of two or several solvents from the family of solvents which have the following characteristics:
The hydrophilic solvent must be completely miscible with water and should have a boiling point in the range of 40° C. to 95° C. at atmospheric pressure. If the solvent forms an azeotropic mixture with water then the azeotrope should have a water content of less than 30%. The solvent--even when it contains up to 20% water--should allow for a reasonably fast settling rate of the solids to be treated. The settling rate (as defined in Tryebal, pp. 639, 2nd ed., 1968) measured in a cylindrical tube (35 mm wide, 250 mm high) should be equal or higher than 7 mm/min for a slurry concentration (mass of solid/volume of slurry) in the range of 150 to 420 g/l. Examples of such solvents are: acetone, methanol, ethanol, isopropanol; the preferred solvent is acetone. This part of the process would be similar for any organic contaminant, which is soluble in the organic leaching solvent and has a partition coefficient between the solid fraction and the leaching solvent with a value smaller than 5, preferably smaller than 2.
Variations may be required for mixed systems and in particular contaminants with a higher solubility in water than PCB. Once again, the key to the process is the understanding of the importance of partition coefficients. In mixed systems, partitioning can be expected to be a function of how the contaminants interact relative to each other in the presence of water, solvents and the solid fraction.
The products from the second step are: (1) a hydrophilic solvent/water mixture containing nearly all of the PCB contamination which requires further treatment and (2) a PCB free soil/solvent mixture from which the solvent must be recovered and returned to the process cycle with the soil now being decontaminated and ready to be returned to the environment. A small fraction of this clean soil is utilized in an absorption column to extract the trace amounts of PCBs from the water effluent of the first step. An analagous situation would exist were the contaminant something other than PCB.
The third step of the process is a stripping operation in which the PCB containing stream from above is contacted in a liquid-liquid extractor with an hydrophobic solvent and an aqueous salt solution.
The stripping operation is facilitated by adding excess amounts of aqueous salt solution. The salt concentration in the solvent-water mixture can be in the range of 0% to 100% of the saturation value, preferably 50 to 90%, whereby the salt can be any mineral salt with the preferred salt being potassium sulfate. The water to solvent ratio should be in the range of 1 to 10, preferably 1 to 5 and most preferably 1 to 3.5. The addition of an aqueous salt solution reduces the solubility of PCB in the solvent-water mixture from step 2, and thus increases the stage efficiency of the stripping operation.
The hydrophobic solvent should be imiscible with the hydrophilic solvent-water mixture, should have a density of less than 0.9 g/ml, should have a high solubility for the organic contaminant, and when agitated should not emulsify with the hydrophilic solvent-water mixture. The hydrophobic solvent should be selected so that the partition coefficient of the organic contaminant between the hydrophobic and the hydrophilic solvent is equal or greater than 3, preferably greater than 10, and most preferably greater or equal to 20 for the entire range of the ratio of water to hydrophilic solvent. For a given choice of hydrophilic and hydrophobic solvents, this step of the process can be used successfully for any organic contaminant having a partition coefficient, of at least 3, preferably greater than or equal to 10 and most preferably greater than or equal to 20 defined as the ratio of the concentration of the contaminant in the hydrophobic solvent to that in the hydrophilic solvent.
This step is required to separate the PCBs from the aqueous phase which is inconvenient for the final destruction step and also, one can concentrate the PCBs in this step further reducing the volume of contaminated sample required for handling.
The desired volume reduction of the contaminated sample in this step can be achieved by the proper choice of the ratio of leaching to stripping solvent, which should be in the range of 1 to 10, and the appropriate addition of aqueous salt solution. This method of concentrating the contaminated sample has two important advantages. It requires very little energy and because no evaporation of solvent is involved the choice of the hydrophobic solvent is not restricted by vapor pressure considerations. The hydrophobic solvent is one from the family of solvents of the methane series with 6 to 16 carbon atoms per molecule, preferably kerosene and toluene, with kerosene being the most preferred solvent.
The two streams which leave this step are the PCB concentrated in stripping solvent which proceeds to final destruction either by chemical means (KPEG Reagent) or by incineration and the hydrophilic solvent/water mixture containing trace PCBs. The solvent/water mixture goes next to a distillation column in which the solvent is released and returned to the leaching process described in the second step. The aqueous salt solution contaminated with trace amounts of PCB leaving the distillation column is recycled to the front of the stripping process. In this process step, the organic contaminant is concentrated from the hydrophilic to the hydrophobic via a multi-stage stripping operation. Once again, this approach has general applicability, if a clear understanding of the partitioning characteristics of the contaminants are known.
The fourth step of the process is an adsorbtion operation in which the water fraction from the first step is decontaminated by adsorbing the organic contaminant such as PCB on the surface of a portion of cleaned sediment obtained in step 2. The water is contacted with the cleaned sediment and then separated from the now contaminated sediment. This can be a multistage step with this fourth step repeated for each stage. The actual amount of cleaned sediment required in this step depends on the partition coefficient of the contaminant between the solid and the water fraction, the number of stages, and on the desired level of decontamination. The product streams leaving the fourth step are:
(1) contaminated sediment which is returned to the leaching step where it is combined with new untreated sediment from step 1, and
(2) decontaminated water, which is ready to be returned to the environment. This step of the process will work successfully with any organic contaminant having a partition coefficient between the solid fraction (soil, sediment and associated materials) and the liquid fraction with a value of equal to or greater than 20, preferably greater than 100 and most preferably greater than 1000.
The advantages of the process in accordance with the present invention are:
exceptionally high recovery of PCBs from contaminated solids, sediments and sludges;
to obtain fully cleaned sediment wherein there is complete removal of residual solvents as well as PCBs;
to obtain a solid and a water fraction which can safely be returned to the environment.
low energy requirements since no energy intensive steps are involved in the solvent extraction operation;
low raw material requirements since there is complete recycling of solvents.
These and other advantages and objects of the present invention will become clear from the following detailed description taken with the attached drawing, wherein:
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a flow chart of the process in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the process, contaminated sediment provided at 1 typically comprises 100 parts (by weight) sediment, including 95 parts contaminated water, 5 parts contaminated solids and 0.1 parts organic contamination. The sediment is fed to a horizontal belt filter at 2 wherein the original composition is broken up into a solid fraction typically containing a total of 10 parts including 5 parts water, 5 parts solid and approximately 0.1 parts organic and a liquid fraction 4 typically comprising 90 parts total weight of which approximately 90 parts is water and the remaining constituents comprising trace solids and trace organics.
The solid fraction is fed in step 5 to a multistage countercurrent extraction process with a hydrophilic solvent typically 10 parts of acetone from acetone recovery unit 12 for the 10 parts of solid fraction. As a result of this extraction, decontaminated sediment and acetone/water mixture are obtained at 6 including typically 4 parts of acetone and approximately 5 parts of solid and a contaminated acetone/water mixture is obtained at 7.
The decontaminated sediment and acetone water mixture is steam stripped of the acetone at 8 so that decontaminated sediment which is able to be released to the environment is obtained at 9 and contains approximately 5 parts of solid and 5 parts of water. The stripped acetone is fed to the acetone recovery unit 12 wherein acetone is separated from any remaining water, with acetone being recycled to the multistage countercurrent extraction unit 5 and the water recycled to a stripping column 10 to be described later.
The contaminated acetone water mixture from 7 is fed to stripping column 10 wherein the contaminant is transferred from the leaching solvent to a stripping solvent, in this instance kerosene. The decontaminated acetone water mixture from the stripping column 10 is received at 11 and acetone and water are separated from each other in the recovery unit 12.
The stripping column receives approximately 5 parts of kerosene for the total 20 parts of materials received from step 7. After the stripping is taking place and the contaminants are concentrated in the stripping solvent, the contaminated kerosene at 13 comprises 5 parts of kerosene and approximately 0.1 parts of organic contaminant. In a contaminant disposal kerosene recovery unit 14, the contaminant is separated from the kerosene so that the kerosene is recycled to the stripping column 10.
The liquid fraction 4 which only contains trace organic contaminants, is fed to 15 where clean sediment is provided so that the contaminant is adsorbed on the clean sediment. At 17 approximately 90 parts of clean water are obtained which can be released to the environment. The clean sediment for 15 can be obtained from clean sediment 16 which is in part recycled from the decontaminated sediment in step 9. Moreover, the contaminated sediment obtained from step 15 can be fed to the multiphase counter-current extraction process step 5 so as to decontaminate the sediment.
The initial separation of the liquid in solid fractions at 2 can be by either filtration, centrifugation or by means of a horizontal belt filter system.
The leaching process carried out at 5 can be carried out by the use of a mixer-settler type continuous countercurrent contactor. The liquid extraction carried out in the stripping column 10 can take place in an agitated extraction tower such as a rotating disk unit. The adsorbtion of the contaminant on clean sediment at 15 can be carried out in a fixed bed adsorbtion column or in a multi-stage mixer-settler.
EXAMPLE
An environmental sediment from Waukegan Harbor (Michigan) containing 82% water was separated by vacuum filtration into a liquid fraction and a wet solid fraction containing 57% water. The PCB concentration of the liquid fraction was determined using EPA-Method 608 and found to be 9 ppm. The wet solid fraction was analyzed by a soxhlet procedure disclosed at Analytical Chemistry, 1985, 57, 2452-2457. The PCB concentration in the solid fraction was 33100 ppm on a dry basis. The calculated partition coefficient was K=3678.
Using the wet solid fraction of Waukegan Harbor sediments and three different solvents: Acetone, Methanol and Isopropanol the leaching step was carried out. The sediment was contaminated with Aroclor 1242.
Amounts of 7.5 g of wet sediment and of 30 ml of solvent was filled in a 50 ml centrifuging tube and sealed off with a screw top. The specimens were agitated for one hour with a wrist action shaker and then centrifuged for 30 minutes at 3000 rpm. The supernate was decanted, vacuum filtrated through a 0.45 μm organic filter and replaced with new solvent. This procedure--which defines one stage--was repeated four times. The PCBs were then transferred to Methylenechloride by adding 200 ml of a 2% Na 2 SO 4 aqueous solution to the 30 ml of leachate and performing three successive liquid-liquid extractions with 60 ml of Methylenechloride each. The combined extracts were then dried and cleaned up, following the procedures in method 608 of USEPA and analyzed by gaschromatography. The results are presented in table I.
TABLE I__________________________________________________________________________ RUNNING TOT. OF PCB-CONC. IN SOLID PCB REMOVED/ PCB REMOVED/ OVERALL STAGE AFTER N-th STAGE, UNIT MASS OF UNIT MASS OF LEACHING EFFI- ASSUMING ALL PCB STAGE SOLID SOLID EFFICIENCY CIENCY ASSOC. WITH SOLIDSOLVENT # (ppm) (ppm) (%) (%) (ppm)__________________________________________________________________________METHANOL 0 th 0 0 32508 1 st 26085 26085 80.24 80.2 6424 2 nd 5429 31514 96.94 84.5 995 3 rd 863 32376 99.59 86.7 132 4 th 114 32490 99.94 86.2 18 *5 th 16 32506 99.99 87.1 2 *6 th 2 32508 100.00 0ISOPROPANOL 0 th 0 0 32914 1 st 27537 27537 83.66 83.7 5378 2 nd 4250 31787 96.57 79.0 1128 3 rd 844 32630 99.14 74.8 284 4 th 213 32843 99.78 74.9 71 *5 th 56 32900 99.96 79.0 15 *6 th 15 32914 100.00 0ACETONE 0 th 0 0 33641 1 st 27656 27656 82.21 82.2 5986 2 nd 5376 33032 98.19 89.8 610 3 rd 527 33559 99.75 86.4 83 4 th 71 33630 99.97 86.1 11 *5 th 10 33640 100.00 84.6 1 *6 th 1 33641 100.00 0__________________________________________________________________________ *THE VALUES FOR THE 5 th AND 6 th STAGE ARE EXTRAPOLATED VALUES FROM STAGES 1 THROUGH 4.
The same procedure was performed with a sediment obtained from Franklin Institute. The contaminant was Aroclor 1260, the solvent used was methanol and the agitation times were six and 24 hours respectively. The results are given in Table II.
__________________________________________________________________________ PCB REMOVED TOTAL PCB IN THE 1 st, 2 nd, REMOVED AFTER PCB-CONC IN SOLID . . . Nth, STAGE NO OF STAGES OVERALL AFTER N-TH STAGE,AGITATION PER UNIT MASS PER UNIT MASS LEACHING STAGE ASSUMING ALL PCBTIME STAGE OF SOLID OF SOLID EFFICIENCY EFFICIENCY ASSOC. WITH SOLID(hrs) # (ppm) (ppm) (%) (%) (ppm)__________________________________________________________________________24 0 th 876 1 st 788.0 788.0 89.91 89.9 88 2 nd 80.7 868.7 99.12 91.3 8 3 rd 7.1 875.8 99.92 91.4 1 4 th* 0.6 876.4 99.99 90.0 0.1 5 th* 0.1 876.5 100.00 0.0 6 0 th 935 1 st 816.0 816.0 87.32 87.3 119 2 nd 101.6 917.6 98.19 85.7 17 3 rd 14.9 932.5 99.78 87.8 2 4 th* 1.8 934.3 99.98 89.0 0.2 5 th* 0.2 934.5 100.00 0.0__________________________________________________________________________ *THE VALUES FOR THE 4 th AND 5 th STAGE ARE EXTRAPOLATED FROM STAGES 1 THROUGH 3.
In order to carry out the step of stripping, acetone was spiked with PCBs (Aroclor 1242) to a concentration of 44 μg/ml. Aliquotes of this stock solution were mixed with various amounts of kerosene and aqueous K 2 SO 4 solution. The independent variables were the ratio of water to acetone (R A ), the ratio of acetone to kerosene (R B ) and the concentration (in mass %) of K 2 SO 4 in the water-acetone mixture. The dependent variable was the transfer efficiency. (η). The liquids were filled into a glass bottle, which was sealed with a teflon lined screw top, and then agitated for one hour. After allowing 30 minutes for phase separation the kerosene was siphoned off and its PCB-conc. analyzed by gas chromatography. The results in table III show that stage efficiencies of higher than 80% can be achieved.
TABLE III______________________________________Ratio of Ratio of K.sub.2 SO.sub.4 in Transferwater to acetone acetone to kerosene water-acetone efficiencyR.sub.A R.sub.B (mass %) (%)______________________________________3.5 4 0.2 833.5 4 1.2 825 4 0.2 815 4 1.2 83______________________________________
The liquid fraction of the original sediment contains small amounts of PCBs. They are removed by adsorbing them onto a small quantity of the cleaned solid fraction of the sediment.
The step of adsorbtion was carried out by providing two samples of 150 ml of the liquid fraction, containing 9 ppm of Aroclor 1242. The samples were each mixed with 8.5 g of the PCB-free solid fraction of Waukegan Harbor sediments. The mixture was agitated for 10 minutes. After complete settling of the solids the liquid fraction was decanted and vacuum filtrated with a 0.45 μm filter and analyzed for PCBs using method 608 of USEPA and gaschromatography. The PCB concentration was below detection limit in both samples.
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A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material adsorbing residual contaminants from the liquid fraction are adsorbed onto decontaminated solids to produce decontaminated liquids and contaminated solids.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from Korean patent application no. 10-2012-0068800 filed Jun. 26, 2012, all of which is incorporated herein by reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a gasifying apparatus including a variable gasifier and used as both a power generator and a combustion boiler and a method of driving the same, and more particularly to a gasifying apparatus in which a combustion boiler and a generator engine, driven with synthesis gas, are associated with a single gasifier, and for producing synthesis gas proper to a technical field of the gasifier by selectively applying an upflow gasifier and a downflow gasifier according to the technical field of the gasifier.
2. Description of the Prior Art
Gasification is a technology that produces synthesis gas containing carbon monoxide (CO) and hydrogen (H 2 ) from carbon in fuel consisting of hydrocarbons through an endothermic reaction of carbon using partial oxidation heat, carbon dioxide (CO 2 ), and water (H 2 O).
Various gasifying apparatuses, to which the gasification technology is applied, are developed to be suitable for various fuels, oxidants, and purposes thereof.
If air and water vapor are used as gasifying agents in a fixed bed gasifier employed in a small-sized system, low calorie gas of 1,000 kcal/Nm 3 to 2,000 kcal/Nm 3 may be produced.
In general, a downflow-type fixed bed gasifying apparatus is used to generate distributed power for the purpose of reducing produced tar.
However, since the downflow-type gasifying apparatus has slightly difficult starting-up conditions, the easily operable upflow-type gasifying apparatus is recommended for use when the product synthesis gas is burnt itself or with oil.
That is, the upflow-type gasifier has merits in higher thermal efficiency, easier control, and higher compatibility of fuel conversion than the downflow-type gasifier, but has also drawbacks such as high quantity of product tar, high costs for filtering the synthesis gas, and most of all, removal of the tar from the product synthesis gas.
Meanwhile, the downflow-type gasifier may produce synthesis gas containing less tar and grains, but can sustain a stable process only when moisture is 20% or less within in a fuel.
Most enterprises and facility farms have different seasons of demanding electric power and using heat. Thus, since gasifiers, which use electric power or heat respectively, must be used to generate electric power or to burn synthesis gas by using synthesis gases produced through the gasifiers, facility costs increase.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a gasifying apparatus with a variable gasifier using a power generator and combustion boiler and a method of driving the same such that a proper quality of synthesis gas, produced by selectively applying upflow gasifcation or downflow gasification with a single gasifier, is supplied to be suitable for the purpose.
In order to accomplish this object, there is provided a gasifying apparatus with a variable gasifier using a power generator and combustion boiler, including: a variable gasifier varied such that fuel such as coal, biomass, RDF, and RPF is fed to perform upflow gasification or downflow gasification; a filtration device filtering synthesis gas produced by the variable gasifier; a feed controller controlling feeding direction of the synthesis gas filtered by the filtration device; and a combustion boiler and a gas engine driven with the synthesis gas selectively fed by the feed controller.
The gasifier includes: an introduction chamber having a fuel feeder formed at a top through which fuel is introduced; a gasification chamber positioned under the introduction chamber and a rotary grate formed on the bottom thereof to accumulate the fuel such that gasification is performed and to discharge ash after combustion is completed through the lower side; an outer chamber enclosing the gasification chamber, separated from the introduction chamber by a partition, and having an ash discharging hole formed on the bottom; a first gasification agent injection hole inserted into the outer chamber to communicate with the gasification chamber and inject gasification agent during the downflow gasification; a second gasification agent injection hole communicating to the lower side of the outer chamber and injecting the gasification agent during the upflow gasification; and a passage opening/closing unit including three directional passages as discharging apertures through which the synthesis gas is discharged from a side of the partition to the introduction chamber, the outer chamber, and the outside, communicating to the outer chamber with the synthesis gas discharging hole during the downflow gasification and communicating to the introduction chamber with the synthesis gas discharging hole during the upflow gasification for the discharge of the synthesis gas.
In accordance with another aspect of the present invention, there is provided a method of driving the gasifying apparatus including the steps of: introducing fuel through a fuel feeder to be accumulated in a gasification chamber of a gasifier while blocking oxygen from being introduced; determining whether the synthesis gas, which is produced by gasifying the fed fuel, is used for power generation or for a combustion boiler; communicating a synthesis gas discharging hole of a passage opening/closing unit with the introduction chamber or the outer chamber according to the determination; performing upflow gasification or downflow gasification by feeding gasification agent through a first or a second gasification agent injection hole according to the determination; producing the synthesis gas by performing the upflow gasification or the downflow gasification according to the performance of the upflow gasification or the downflow gasification; filtering foreign matter contained in the product synthesis gas; and generating electric power by feeding the synthesis gas filtered in the filtration into the gas engine or recovering heat by feeding the filtered synthesis gas into the combustion boiler.
According to the gasifying apparatus with a variable gasifier using a power generator and combustion boiler and a method of driving the same in accordance with the present invention, the gasifying apparatus further includes a passage opening/closing unit provided in the front side of a synthesis gas discharging hole to selectively communicate an upper space and a lower space in the gasifier partitioned by the gasification chamber and to change an injection position of the gasification agent such that upflow gasification and downflow gasification can be selectively performed.
Especially, when the synthesis gas is used for generating electric power or the combustion boiler, gasification suitable for the purpose is performed such that the synthesis gas is produced and fed so that unnecessary filtration can be omitted and thermal efficiency can be improved. Therefore, easy control can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic view illustrating a gasifying apparatus for generating electric power and providing heat using a variable gasifier according to an embodiment of the present invention;
FIG. 2 is a schematic sectional view illustrating a gasifier according to an embodiment of the present invention;
FIGS. 3A , 3 B, and 3 C are schematic sectional views illustrating a passage opening/closing unit according to an embodiment of the present invention;
FIGS. 4 and 5 are schematic sectional views illustrating a gasifying agent inflow adjustor of a first gasifying agent injection hole according to an embodiment of the present invention;
FIG. 6 is a block diagram illustrating a method of driving a gasifying apparatus according to an embodiment of the present invention;
FIGS. 7 and 8 are schematic views illustrating driving in which upflow gasification and downflow gasification are carried out in the gasifier according to the embodiment of the present invention;
FIGS. 9 and 10 are graphs illustrating components of synthesis gas produced during the upflow driving and the downflow driving of the gasifier according to the embodiment of the present invention; and
FIG. 11 is a schematic view illustrating a measuring device collecting tar contained in the synthesis gas produced in the gasifier according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description and drawings, the same reference numerals are used to designate the same or similar components, and so repetition of the description on the same or similar components will be omitted.
FIG. 1 is a schematic view illustrating a gasifying apparatus for generating electric power and providing heat using a variable gasifier according to an embodiment of the present invention.
As illustrated, a gasifying apparatus 1 according to an embodiment of the present invention includes a variable gasifier 10 varying such that fuel such as coal, biomass, RDF, and RPF is fed to perform upflow gasification or downflow gasification, a filtration device 20 filtering synthesis gas produced by the variable gasifier 10 , a feed controller 30 controlling feeding direction of the synthesis gas filtered by the filtration device 20 , and a combustion boiler 40 and a gas engine 50 driven with the synthesis gas selectively fed by the feed controller 30 .
The gasifying apparatus 1 is configured to selectively enable upflow gasification and downflow gasification using a single gasifier such that synthesis gas is produced through downflow gasification, driving conditions of which are complicated when synthesis gas with low foreign matter content such as tar is used to drive a gas engine while such that the synthesis gas is produced through upflow gasification easily driven when the synthesis gas is fed to a combustion boiler burning the synthesis gas as a fuel regardless of the content of tar.
FIG. 2 is a schematic sectional view illustrating a gasifier according to an embodiment of the present invention.
As illustrated, the gasifier 10 of the present invention is a vertical type in which an introduction chamber 11 , a gasification chamber 12 , and an outer chamber 13 are sequentially installed from top to bottom, wherein the outer chamber 13 encloses the gasification chamber 12 so that the outer chamber 13 communicates with the introduction chamber 11 via the gasification chamber 12 .
The introduction chamber 11 is provided with a fuel feeder 111 on top. The fuel feeder 111 is configured such that two layer gate valves (slide gates) 113 are installed under a hopper 112 serving as a fuel supplying unit to be sequentially opened such that fuel only is introduced therein and air is prevented from being introduced therein.
The gasification chamber 12 has an upper side communicating with the introduction chamber 11 and a lower side communicating with the outer chamber 13 and includes a porous plate, that is, a grate 121 installed at the lower side to discharge ash which is already burnt or gasified. The grate 121 may be a circular plate in which a plurality of pins protrude from the upper side thereof or in which has multi-layer thin circular plates, and includes a rotary shaft, rotated by a driving force, coupled to the lower side to scrape ash accumulated on the gasification chamber 12 during the rotation to be easily discharged.
Next, the outer chamber 13 encloses the gasification chamber 12 and has upper sides divided by the introduction chamber 11 and a partition 17 . The outer chamber 13 is provided with an ash discharging hole 131 formed at the lower side to collect and discharge the ash discharged from the gasification chamber 12 . In this case, the ash discharging hole 131 includes a collector 132 and a screw conveyor 133 such that the ash discharged from the ash discharging hole 131 can be continuously discharged out of the gasifying apparatus 1 , wherein the screw conveyor 133 has an upward slope from the collector 132 such that the ash and a screw block a passage to prevent gas from being discharged through the ash discharging hole 131 from the outer chamber 13 .
As described above, the gasifier 10 including the introduction chamber 11 , the gasification chamber 12 , and the outer chamber 13 further includes a first gasification agent injection hole 14 and a second gasification agent injection hole 15 to feed a gasification agent consisting of air or a mixture of air and water vapor. The first gasification agent injection hole 14 communicates with the gasification chamber 12 by penetrating the outer chamber 13 such that the gasification agent is injected during the downflow gasification, while the second gasification agent injection hole 15 communicates with the lower side of the outer chamber 13 such that the gasification agent is injected during the upflow gasification.
Valves are mounted on lines of the first and second gasification agent injection holes 14 and 15 such that the gasification agent may be selectively injected. For the upflow gasification in the gasification chamber 12 , the gasification agent may be fed through the second gasification agent injection hole 15 and a forced draft fan (FD fan) 70 may be installed at a front line of the second gasification agent injection hole 15 such that forced blowing toward the gasification chamber 12 can be carried out. For the downflow gasification, an induced draft fan (ID fan) 60 is installed at a rear line connected to a later-described synthesis gas discharging hole 163 such that blowing is carried out by suctioning by the gasifier 10 , resulting in a fluid stream throughout the gasifying apparatus 1 .
A passage opening/closing unit 16 is installed at a side of the partition 17 partitioning the upper side of the outer chamber 13 enclosing the gasification chamber 12 and the lower side of the introduction chamber 11 . The passage opening/closing unit 16 has three directional passages such as a synthesis gas discharging hole 163 communicated with the outside of the gasifier 10 , a passage 164 communicated with the introduction chamber 11 , and a passage 165 communicated with the outer chamber 13 and closes any one of the two passages 164 and 165 that are communicated with the introduction chamber 11 and the outer chamber 13 such that only one of the two passages 164 and 165 communicated with the introduction chamber 11 and the outer chamber 13 the synthesis gas communicates with the synthesis gas discharging hole 163 to discharge the synthesis gas.
As illustrated in FIGS. 3A and 3B , the passage opening/closing unit 16 may include an opening/closing chamber 161 elongated horizontally and an opening/closing piston 162 inserted into the opening/closing chamber 161 .
The opening/closing chamber 161 may be elongated in the longitudinal direction including the vertical direction in addition to the horizontal direction as depicted in the drawings, wherein the synthesis gas discharging hole 163 communicates with the center of the opening/closing chamber 161 and the upper passage 164 communicated with the upper introduction chamber 11 and the lower passage 165 communicated with the outer chamber 13 are formed at both lateral sides.
The opening/closing piston 162 come in close contact with the inner surface of the opening/closing chamber 161 for creating an air-tight seal and is pushed and pulled by a piston rod 166 to open and close the passages communicated with the introduction chamber 11 and the outer chamber 13 .
A plurality of opening/closing pistons 162 is provided to open and close the passages 164 and 165 communicated with the introduction chamber 11 and the outer chamber 13 , respectively, and includes respective piston rods 166 extending out, as illustrated in FIGS. 3A and 3B , to work individually or includes a connector bar 167 connecting the two opening/closing pistons 162 to each other as shown in FIG. 3C to integrate the two opening/closing pistons 162 and the connecting rod 166 extending from any side thereof such that the opening/closing pistons 162 may move. When the two opening/closing pistons 162 are integrated with each other, the three passages of the opening/closing chamber 161 are arranged in the same interval such that the length of the connector bar may correspond to the interval between the passages of the opening/closing chamber 161 so that one passage is opened when another passage is closed.
The first gasification agent injection hole 14 may be configured to control the feed of the gasification agent.
Referring to FIG. 4 , the first gasification agent injection hole 14 according to the present invention includes an outer tube 141 with a flange formed at an outwardly protruding end, an inner tube 142 inserted in the outer tube 141 , a seal 144 sliding within the inner tube 142 to open and close gasification agent introduction holes formed in the inner tube 142 , and a cylinder 146 moving the seal 144 and controls the feed of the gasification agent introducing into the gasifier.
The outer tube 141 has an outwardly protruding closed end, a closed end connected to the gasification chamber 12 , and a plurality of axial or ring-shaped gasification agent introduction holes 143 formed on the outer surface.
The inner tube 142 is inserted into the outer tube 141 , has an end located within the gasification chamber 12 , the outwardly protruding end, and a plurality of axial or ring-shaped gasification agent introduction holes 143 formed on the outer surface.
Thus, the gasification agent, that is, air is introduced into the outer tube 141 via the gasification agent introduction holes 143 of the outer tube 141 , is further introduced into the inner tube 142 through the gasification agent introduction holes 143 of the inner tube 142 , and is finally fed into the gasification chamber 12 .
The seal 144 installed in the inner tube 142 is moved in the axial direction to control the feed of the gasification agent to be introduced. For example, the seal 144 has a length in the inner tube 142 to close all the gasification agent introduction holes 143 elongating in the axial direction and moves forward or backward from the cylinder 146 by a seal rod coupled to the rear side of the seal 144 to sequentially open and close the gasification agent introduction holes 143 such that the feed of the introduced gasification agent can be controlled according to the degree of opening the gasification agent introduction holes 143 .
In this configuration, the cylinder 146 , as shown in FIG. 4 , may be installed in the same axial direction as that of the first gasification agent injection hole 14 or in the different axial direction from that of the first gasification agent injection hole 14 as shown in FIG. 5 , and the seal rods 145 are connected to the cylinder 146 with a joint 147 so that width of the apparatus can be minimized.
Meanwhile, the synthesis gas produced in the gasifier 10 is filtered by the filtration device 20 . As illustrated in FIG. 1 , the filtration device 20 includes a cyclone 21 separating solid particles from the synthesis gas discharged from the gasifier, a scrubber 22 spraying washing water to the synthesis gas discharged from the cyclone 21 to remove foreign matter from the synthesis gas, a filter 23 filtering fine particles contained in the synthesis gas passing through the scrubber 22 , and a bypass 24 bypassing the synthesis gas passing through the cyclone 21 directly to the feed controller 30 during the upflow gasification reaction.
The cyclone 21 is a device that separates large-sized solid particles and is basically used to filter the synthesis gas produced during the upflow or downflow gasification.
The synthesis gas passing through the cyclone 21 is directly fed into the feed controller 30 via the bypass 24 or to the scrubber 22 . That is, the synthesis gas produced during the upflow gasification is fed into the feed controller 30 through the bypass 24 to be used only for the combustion boiler 40 , while the synthesis gas produced during the downflow gasification passes through the scrubber 22 and the filter 23 and is finally fed into the gas engine 50 through the feed controller 30 such that electric power is generated. In this case, feed of the synthesis gas discharged from the cyclone 21 to the bypass 24 and the scrubber 22 may be controlled by a distribution valve installed on a transfer pipe, and the passage line passing through the distributed bypass or the scrubber may be directly communicated with the feed controller 30 or combined into one by a combination valve before the communication with the feed controller.
Moreover, the synthesis gas fed into the gas engine 50 by the feed controller 30 may be temporally reserved in a tank 51 and surplus synthesis gas is fed into the combustion boiler 40 to generate heat with water steam when the reservation of the synthesis gas exceeds a limit. In addition, the combustion boiler 40 , as described above, includes oil substitute in a wide sense in addition to a boiler.
Coolant of the gas engine 50 is utilized as reactive water of the combustion boiler 40 so that an arrangement of the gas engine can be utilized.
As illustrated in FIG. 6 , the method of driving a gasifying apparatus according to an embodiment of the present invention includes the steps of: introducing fuel through a fuel feeder to be accumulated in a gasification chamber of a gasifier while blocking oxygen from being introduced; determining whether synthesis gas, which is produced by gasifying the fed fuel, is used for power generation or for a combustion boiler; communicating a synthesis gas discharging hole of a passage opening/closing unit with an introduction chamber or an outer chamber according to the determination; performing upflow gasification or downflow gasification by feeding a gasification agent through a first or a second gasification agent injection hole according to the determination; producing the synthesis gas by performing the upflow gasification or the downflow gasification according to the performance of the upflow gasification or the downflow gasification; filtering foreign matter contained in the product synthesis gas; and generating electric power by feeding the synthesis gas filtered in the filtration into the gas engine or recovering heat by feeding the filtered synthesis gas into the combustion boiler.
Moreover, in the synthesis gas production, the method may further include the sub-step of moving the seal into the inner tube to adjust the number of first gasification agent injection apertures such that the feed of the gasification agent is controlled in the first gasification agent injection hole 14 having the inner tube and the outer tube, which are formed with a plurality of first gasification agent injection apertures on the outer surface, when the downflow gasification is performed.
Moreover, in the filtration, the synthesis gas produced during the downflow gasification passes through the cyclone, the scrubber, and the filter and is fed into the feed controller so that the synthesis gas may be used in power generation, while the synthesis gas produced during the upflow gasification passes through only the cyclone and is fed into the feed controller so that the synthesis gas may be used in heat recovery by the combustion boiler.
Operations during the upflow gasification will be described with reference to FIGS. 1 and 7 .
First, fuel is fed through the fuel feeder 111 such that the fuel is accumulated in the gasification chamber 12 of the gasifier 10 , the gasification agent is forcibly injected into the second gasification agent injection hole 15 through the FD fan 70 , and at the same time, the passage opening/closing unit 16 , as shown in FIG. 3B , blocks the passage 165 communicated with the outer chamber 13 and opens the passage 164 communicated with the introduction chamber 11 such that the synthesis gas discharging hole 163 communicates with the introduction chamber 11 .
When the passages are formed as described above, the gasification agent injected through the second gasification agent injection hole 15 is fed toward the introduction chamber 11 through the lower side of the gasification chamber 12 so that air stream becomes an upflow. The accumulated fuel in the gasification chamber 12 has a combustion layer, a gasification layer, a thermal decomposition layer, and a dry layer from the lowest layer to the uppermost layer such that heat transfer may be performed. In this case, the combustion gas in the combustion layer moves upward and carbon in the fuel reacts with carbon dioxide (CO 2 ) and water vapor to produce synthesis gas, and the product synthesis gas is discharged out of the synthesis gas discharging hole 163 through the passage opening/closing unit 16 .
The synthesis gas discharged from the synthesis gas discharging hole 163 is fed into the feed controller 30 through the bypass 24 after large-sized grains contained in the synthesis gas are separated while passing through the cyclone 21 , and the feed controller feeds the synthesis gas to the combustion boiler 40 to generate heat.
Operations during the downflow gasification will be described with reference to FIGS. 1 and 8 .
First, the fuel is fed by the fuel feeder 111 to be accumulated in the gasification chamber 12 of the gasifier 10 , and the passage opening/closing unit 16 , as illustrated in FIG. 3A , opens the passage 165 communicated with the outer chamber 13 and blocks the passage 164 communicated with the introduction chamber 11 such that the synthesis gas discharging hole 163 communicates with the outer chamber 13 and closes the second gasification agent injection hole 15 .
When the ID fan 60 installed at the rear end of the filtration device 20 is driven, air stream becomes a downflow such that the gasification agent (air) is introduced from the first gasification agent injection hole 14 by the suctioning force of the ID fan 60 , is fed to the middle portion of the gasification chamber 12 , and moves to the outer chamber 13 through the lower side of the gasification chamber 12 , while the seal 144 in the first gasification agent injection hole 14 moves to adjust the number of opened gasification agent introduction holes 143 such that the quantity of the gasification agent fed in the form of introducing downflow can be controlled.
Moreover, the fuel accumulated in the gasification chamber 12 , to the middle portion of which the gasification agent is introduced, forms the combustion layer, the lower side of the combustion layer to which maximum combustion heat is supplied forms the gasification layer, the upper side of the combustion layer to which heat of the combustion layer is transferred forms the thermal decomposition layer, and the upper side of the thermal decomposition layer forms the dry layer. The synthesis gas discharged through the lower end of the gasification chamber moves upward along the inner wall of the outer chamber 13 and is discharged out through the synthesis gas discharging hole of the passage opening/closing unit 16 .
The synthesis gas discharged through the synthesis gas discharging hole 163 passes through the cyclone 21 while separating large-sized grains contained therein, passes through the scrubber 22 and the filter 23 sequentially such that foreign matter is removed as much as possible, and is fed into the feed controller 30 .
The feed controller 30 feeds the synthesis gas into the gas engine 50 such that power generation is performed. In this case, the tank 51 is installed between the feed controller 30 and the gas engine 50 such that the synthesis gas can be steadily fed to the gas engine 50 . Further, when the synthesis gas produced for the gas engine is excessively produced, the surplus thereof may be fed to the combustion boiler 40 to generate heat.
Hereinafter, the present invention will be described through preferred embodiments in detail.
Embodiment
As illustrated in FIG. 1 , in the gasifying apparatus according to the embodiment of the present invention, the position and direction of injecting air are controlled to restrict the generation of tar and flow of the synthesis gas is changed by the opening/closing piston in the passage opening/closing unit 16 of the gasifier, as shown in FIGS. 3A and 3B , for the purpose of generating heat and electric power.
Fuel fed to the gasifier has compositions and calories as listed in Table 1, operating conditions of the gasifier are listed in Table 2, compositions and calories of the synthesis gas produced by injection the fuel and by operating the gasifier are listed in Table 3, and graphs exhibiting operation results of the upflow gasifier and the downflow gasifier are illustrated in FIGS. 9 and 10 .
TABLE 1
Proximate analysis (wt %)
Moisture
Voltaile
Fixed carbon
HHV
Sample
(M)
matter (V.M)
Ash
(F.C)
(kcal/kg)
Chinese coal
0.81
7.18
12.44
79.57
7,280
Wood chips
21.6
60.14
3.85
14.34
4,130
TABLE 2
Feed of fuel
Feed of air
Max. temp. of
Fuel
(kg/h)
(Nm 3 /h)
gasifier (° C.)
Chinese coal
10-15
20-30
1,000-1,200
Wood chips
40-50
50-60
700-800
(upflow)
Wood chips
60-70
75-85
800-900
(downflow)
TABLE 3
HHV
Sample
H 2 (%)
CO (%)
CO 2 (%)
CH 4 (%)
(kcal/Nm 3 )
Chinese coal
17.4
20.7
11.9
1.6
1,240
(upflow)
Wood chips
7.8
25.0
8.9
3.0
1,213
(upflow)
Wood chips
14.5
17.3
16.0
2.2
1,117
(downflow)
As listed in Table 3, production of hydrogen and carbon dioxide in the downflow gasifier is higher than that in the upflow gasifier and the higher heating value (HHV) in the upflow gasifier is higher than that in the downflow gasifier.
Moreover, the quantity of tar produced by variable operation of the gasifiers is compared and analyzed.
Tar is collected from sampling ports installed to the synthesis gas discharging holes of the gasifiers by a method as illustrated in FIG. 11 , based on Guideline for Sampling and Analysis of Tar and Particles in Biomass Producer Gases Version 3.3 proposed J. P. A. Neeft.
Tar solution in an impinger is filtered with a paper filter and tar attached on the inner wall of the impinger is resolved with isopropanol collected solution distilled by a distiller.
When matter remaining after the distillation is defined as tar and a concentration of the tar is obtained from a sampling gas flowrate, the quantity of tar produced by the gasifying apparatus according to the present invention ranges 100 to 150 g/Nm 3 of fuel fed in the upflow gasifier, while the quantity of tar produced by the downflow gasifier ranges 3.9 to 4.4 g/Nm 3 . The synthesis gas produced by the downflow gasifier could be used in the gas engine by reforming a catalyst or by performing wet filtration.
Although a preferred embodiment of the present invention has 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 spirit of the invention as disclosed in the accompanying claims.
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A gasifying apparatus including a variable gasifier and used as both a power generator and a combustion boiler and a method of driving the same are disclosed. A combustion boiler and a generator engine, driven with synthesis gas, are associated with a single gasifier, and the gasifying apparatus produces synthesis gas proper to a technical field of the gasifier by selectively applying an upflow gasifier and a downflow gasifier according to the technical field of the gasifier.
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FIELD OF THE INVENTION
The invention relates to an adhesive. In particular, the invention relates to a corrugating adhesive and to corrugated products constructed with the adhesive.
BACKGROUND OF THE INVENTION
Corrugated board conventionally is prepared by a process known as the Stein-Hall process. As is generally described in U.S. Pat. No. 2,102,937, the Stein-Hall process employs a corrugating adhesive to bond a corrugated paper “medium” such as a roll or strip, to a liner board on one or both sides of the corrugated medium.
Adhesives used in conjunction with the Stein-Hall process are traditionally alkaline adhesives comprised of ungelatinized raw starch suspended in an aqueous dispersion of cooked starch (carrier). The adhesive is produced by gelatinizing starch in water with sodium hydroxide (caustic soda) to yield a primary mix of gelatinized or cooked carrier, which is then slowly added to a secondary mix of raw (ungelatinized) starch, borax and water to produce the fully formulated adhesive. In the corrugating process, the adhesive is applied (usually at between 25° C. and 55° C.) to the tips of the fluted paper medium or single-faced board, whereupon the application of heat causes the raw starch to gelatinize, resulting in an instantaneous increase in viscosity and tack and formation of the adhesive bond.
Known corrugating adhesives suffer from a number of drawbacks. For example, the speed of the machinery used to prepare the corrugated board sometimes is limited by the rheological properties of the adhesive. During manufacture of corrugated board, the corrugating adhesive typically is spread across the liner board or the corrugated paper medium with a spreader knife or metering roller. It has been observed that conventional adhesives undergo substantial shear thinning when they are spread too quickly, thus leading to problems in applying the adhesive to a corrugating medium in conventional corrugating equipment. The shear thinning thus may serve to limit the speed of the corrugating equipment, and thus may limit the attainable output of corrugated board.
Another drawback relates to the green bonding strength of conventional corrugating adhesives and, more specifically, to the rate at which the tack of the adhesive increases when the corrugated board is in the green state. Typically, corrugated board is processed and handled before the adhesive has fully dried, the adhesive thus being in the green state. If the adhesive has not become tacky quickly enough, then the corrugated board will delaminate during the processing operations that follow the bonding operation. The rate of increase of tackiness of known adhesives thus may be a further limiting factor in the rate of manufacture of corrugated board.
There continues to be a need in the industry for a corrugating adhesive that will allow the user to control the amount of adhesive applied, minimize the warpage of the final corrugated board and that will allow equipment to run faster and in a more efficient manner.
SUMMARY OF THE INVENTION
The invention provides a composition for producing a stable, consistent aqueous starch-based corrugating adhesive.
One aspect of the invention is directed to an adhesive composition comprising an aqueous solution of a starch, an alkali, and a surfactant. In one embodiment, the adhesive is a foamed adhesive.
Another aspect of the invention is directed to method of producing a corrugating adhesive comprising dispersing a carrier starch in aqueous alkali and borax, uniformly mixing in a raw starch, and adding a surfactant. The surfactant is preferably used at a level of from about 0.05 to about 10 percent actives by weight, based on the total adhesive weight. In the preparation of a foamed adhesive, the process further comprising applying energy to create the foam.
Yet another aspect of the invention is directed to corrugated paperboard constructed with the adhesives of the invention and articles comprising corrugated paperboard.
DETAILED DESCRIPTION OF THE INVENTION
The disclosures of all references cited herein are incorporated in their entireties by reference.
The invention provides corrugating adhesives and, in particular foamed corrugating adhesives.
Foamed adhesives show improved economics and performance over adhesives which are not foamed. Since foamed adhesives do not penetrate porous surfaces to the same extent as non-foamed adhesives, the open time increases and the tendency for pre-cure decreases. In addition, at any given film thickness, a foamed adhesive contains less water than an unfoamed adhesive. Less water in the adhesive leads to little or no warping of the paper substrate. Foamed adhesives also have the ability to hold out on a substrate surface to a greater extent than unfoamed adhesives, resulting in less applied adhesive affording faster machine speeds, faster cure rate and lower adhesive costs.
While methods have been proposed for foaming polymer adhesives, success has been demonstrated only with synthetic polymers. While many surfactants can produce foam, a significant and detrimental impact on the viscosity and flow properties of full formulation corrugating adhesives has been observed. Foamed starched-based adhesives tend to be unstable and dissipate within a few minutes. Starch-based (Stein-Hall) adhesives have the additional requirements of high pH and a heterogeneous system containing both dispersed and granular starch. These latter two requirements have made the task of providing a stable yet effect foamed corrugating adhesive very illusive.
It has now been discovered that surfactants that do not contain, either within the backbone or within a side chain thereof, propylene oxide or ethylene oxide moieties can solubilize ionic groups and are excellent foaming agents for corrugating adhesives. The adhesive of the invention has good foam stability, excellent adhesive properties and good flow characteristics.
The terms “adhesive” and “foamable adhesive,” as used to describe the adhesives of the invention, are used interchangeable herein. While the foamable adhesive is useful in the unfoamed state as a corrugating adhesive, the adhesive may also be foamed, e.g., by the application of energy, to provide a stable and effective foamed corrugating adhesive. Thus, both unfoamed and foamed corrugating adhesives are encompassed by the invention.
The term “corrugated paperboard” as used herein refers to a fluted medium and a facing glued to the tips on one or both sides of the fluted medium. The procedures employed in the production of corrugated paperboard usually involve a continuous process whereby a strip of paperboard is first corrugated by means of heated, fluted rolls. The protruding tips on one side of this fluted paperboard strip are then coated with an adhesive, and a flat sheet of paperboard, commonly known in the trade as a facing, is thereafter applied to these tips. By applying heat and pressure to the two paperboard strips thus brought together, an adhesive bond is formed there between. The above-described procedure produces what is known to those skilled in the art as a single-faced board in that the facing is applied to only one surface thereof. If a double-faced paperboard in which an inner fluted layer sandwiched between two facings is desired, a second operation is performed wherein the adhesive is applied to the exposed tips of the single-faced board and the adhesive-coated tips are then pressed against a second facing in the combining section of the corrugator under the influence of pressure and heat. The typical corrugating process and the operation and use of corrugators in general are described, e.g., in U.S. Pat. Nos. 2,051,025 and 2,102,937.
The foamable adhesive composition of the invention comprises a liquid carrier containing a starch, an alkali, and a surfactant. Each of these ingredients is required to provide the unique blend of adhesive and foam properties. The composition may also, optionally, contain a boron-containing compound.
The liquid carrier is preferably water, but may further also include any other components as may be known in the art or found to be suitable. The foamable composition will generally contain from about 10 to about 97 percent by weight of water. Preferably the composition contains from about 50 to about 80 percent by weight of water.
A number of starches may be used to prepare the corrugating adhesive of the invention. Starches such as rye, corn, potato, wheat, sorghum, and tapioca starches are all useful. The starch portion of the adhesive formulation preferable comprises both a granular (raw starch) and dispersed starch (carrier starch).
The base starch material (raw starch) can be derived from any plant source including, but not limited to, corn, potato, wheat, rice, sago, tapioca, waxy maize, sorghum and high amylose starch, i.e., starch having at least 45% and more particularly 65% amylose content, such as high amylose corn. Preferred is starch derived from wheat and/or corn. By “base” starch is meant raw or native starch, i.e., starch as it comes from the plant source. Such base starch include natural starches as well genetically altered and hybrid starches.
The dispersed starch may be native as above or degraded to reduce the viscosity of the solution or modified, i.e., crosslinked. Starches for use in accordance with the invention may be degraded by any means known in the art. Means of obtaining a degraded starch include the action of acids, enzymes, dry heat reactions (i.e. dextrins), oxidizing agents and catalysts capable of reducing molecular weight in a controlled and reproducible manner. The starch can be converted in the granular form before dispersion or after being dispersed into water.
The raw and/or carrier starch may also be modified to contain a functional groups such as cationic, anionic, non-ionic or hydrophobic substituent. Methods for modifying starch are well known in the art. See, e.g., U.S. Pat. Nos. 2,661,349, 5,672,699, “Starch: Chemistry and Technology”, second edition, edited by R. L. Whistler et al., 1988, pp. 341-343 and “Modified Starches: Properties and Uses”, edited by O. Wurzburg, 1986, Chapter 9, pp. 131-147.
The starches of the present invention are used at from about 15 to about 35 percent, preferably from about 20 to about 30 percent by weight based on the foamable composition as a whole. The preferably levels of starch are typically higher for water resistant grades than those which do not require water resistance. The ratio of raw starch to carrier starch will vary depending on properties desired and generally will range from about 3:1 to about 10:1 by weight depending on the nature of the starch and the viscosity desired. The total amount of starch employed including the gelatinized or cooked carrier and the ungelatinized raw starch will typically be in the range of about 10% to about 50% by weight, based on the weight of the composition.
The adhesive composition also includes an alkali. The alkali is preferably an alkali metal hydroxide, such as sodium hydroxide. While a preferred alkali is sodium hydroxide; other bases may be used in partial or full replacement of the sodium hydroxide and include, for example, alkali metal hydroxides such as potassium hydroxide, alkaline earth hydroxides such as calcium hydroxide, alkaline earth oxides such as barium oxides, and alkali metal carbonates such as sodium carbonate, and alkali metal silicates such as sodium silicate. The alkali may be employed in aqueous or solid form. The alkali is used in amounts sufficient to provide the adhesive with a pH greater than 7, more particularly from about 7.5 to 14 and preferably from 10 to 13. Typically this represents an amount of from about 0.3 to about 5% and preferably from about 1 to about 4% by weight based on the weight of starch.
The corrugating adhesive of the invention may also comprise a boron-containing compound, e.g., borax, boric acid, and borate salts, which is useful as a tackifier. The boron-containing compound is an optional ingredient and, when uses, is typically employed in amounts of up to about 5% by weight, based on the total weight of starch.
A surfactant capable of producing a stable foam is present in the foamable corrugating adhesive composition of the present invention. The surfactant must be of a suitable type and structure so as not to change the viscosity or flow properties of the unfoamed adhesive while providing the ability to create a foam with a void value of from about 15% to about 60%, preferably having greater than 25% void volume. Void volume is defined as the weight fraction of adhesive displaced by the air in the foam. For example a void volume of 40% means that 40 grams out of every one hundred grams of adhesive has been replaced with air.
Stability of the foam is important to most machinery and users in that reliable and consistent application of the adhesive onto the substrate is required. As defined in this invention the stability of the foamed adhesive should be at least 6 hours without significant change in void volume. A more preferable stability of between 24 and 48 hours with less than 10% change in void volume would be desired.
Suitable surfactants for use in the practice of the invention are surfactants that do not contain, either within the backbone or within a side chain thereof, propylene oxide or ethylene oxide moieties. Surfactants capable of solubalizing the highly ionic adhesive without forming a gel tend to have little to no overall charge associated with the surfactant (i.e. non-ionic or amphoteric) and are preferred for use in the practice of the invention.
Examples of suitable surfactants for use in the practice of the invention include anionic, cationic, amphoteric, or nonionic surfactants, or mixtures thereof. Suitable anionic surfactants include, alkyl sulfonates, alkylaryl sulfonates, alkyl sulfates, alkyl and alkylaryl disulfonates, sulfonated fatty acids, sulfates and phosphates of alkylphenols, esters of sulfosuccinic acid and mixtures thereof. Suitable cationic surfactants include, alkyl quaternary ammonium salts, alkyl quaternary phosphonium salts and mixtures thereof. Suitable non-ionic surfactants include alkylphenols, higher fatty acids, higher fatty acid amines, primary or secondary higher alkyl amines, and mixtures thereof. Suitable amphoteric surfactants include disodium lauramino propionate (Monateric1188M available from Uniqema).
For purpose of illustration and clarification, examples of surfactants not suitable for use in the practice of the invention, i.e., surfactants containing propylene oxide or ethylene oxide, include polypropoxyethoxycocamide, fatty acid ethoxylates and deceth-4 phosphate.
The surfactant is used at a level of from 0.05 to 10 percent by weight, and preferably at from 0.2 to 2 percent by weight, based on the total adhesive weight. As some surfactants are provided as solutions, it is to be understood that the percentages recited herein for use are on an “actives” basis.
Any conventional non-chemically functional additives may be incorporated into the adhesive in minor amounts, as desired. Such additives include, for example, preservatives; defoamers; wetting agents; plasticizers; solubilizing agents; rheology modifiers; water conditioners; penetration control agents; peptizers such as urea; gelatinization temperature modifiers; inert fillers such as clay and finely ground polymers; thickeners such as inorganic colloidal clays, guar, hydroxyethyl cellulose, alginates, polyvinyl alcohol, polymers of ethylene oxide and the like; colorants; and emulsions such as polyvinyl acetate. Combinations of such compounds are commercially available and sold as “liquid additives” or “speed enhancers.”
Many applications of corrugated board require the resistance to liquid water and humid conditions. When moisture resistance is desired, the corrugating adhesive may include a moisture-resistance agent, which may be present in an amount effective to impart moisture resistance to the adhesive. The moisture-resisting agent may be a ketone-formaldehyde resin or a melamine-formaldehyde resin. One suitable resin is sold under the trademark ULTRA-GUARD by National Starch and Chemical Company, Bridgewater, N.J. Such resin or resins may be added in a total amount ranging from about 1% to about 4% (about 2-3% based on adhesive solids) in the adhesive composition. Other moisture-resistance agents as may be known in the art or as may be found to be suitable for use in connection with the invention further may be employed to impart moisture resistance.
The adhesive is preferably formulated to have a Stein-Hall viscosity of about 25 seconds to about 60 seconds at 100° F. The Stein-Hall viscosity of an adhesive is a quantity that is defined in the art as the length of time for 100 ml of an original volume of about 335 ml of the adhesive at a given temperature to exit a cylindrical vessel via a calibrated orifice having a diameter of approximately 2.73 mm and centrally located in a disc which is approximately 5.8 cm in diameter. The exact Stein-Hall viscosity of the adhesive composition may be adjusted somewhat by varying the relative amounts of starch, alkali, surfactant, liquid carrier and other ingredients in the adhesive composition.
In the preparation of the corrugating adhesives herein, the method used by the skilled practitioner is not critical and generally any suitable method may be employed without serious consequences. Ordinarily, however, the carrier starch is first gelatinized (cooked) in a portion of the water with the alkali (caustic soda) to provide the carrier component of the adhesive. In a separate vessel, a mixture or slurry is made of the raw starch, borax (optional) and remaining water. The carrier and raw starch mixture are combined to form the final adhesive. Optional ingredients, if desired, can be added at any convenient point during the preparation of either component but are usually added to the finished adhesive.
The foamable adhesive composition of the invention is foamed by the addition of energy, by means known in the art such as, but not limited to, by mechanical and/or chemical means. Air or other gases are added to the foamable adhesive composition along with the addition of said energy to produce a stable, consistent foamed adhesive. Preferably air is used to produce the foamed adhesive. The adhesive foam may be produced by mechanical means such as mechanical stirring or agitation, introduction of gases or by chemical means.
A foamable adhesive composition of the invention typically has a Brookfield viscosity, prior to foaming, of from about 300 to 1,500 cps at 100° F. Preferably the viscosity of the foamed adhesive at 100° F. is from 200 to 2,000 cps regardless of the void volume obtained. Other measurements to the quality and runnabilty of the foamed corrugating adhesive can be used and will not change significantly over the un-foamed adhesive. These include, but are not limited to Stein-Hall viscosity, Bostwick flow measurement and thixothropic ratio.
The adhesive composition of the invention may be used in a corrugated product, such as a single-facer or double-facer paper corrugated board. Methods for making corrugated board are known in the art, and conventional methods preferably are employed in conjunction with the present invention. Generally, the method of making corrugated board comprises forming a bond between a corrugated paper “medium” and a liner board on one of both faces of the corrugated medium. The bond is formed by applying adhesive to the corrugating medium, and calendaring the corrugating medium and liner board between a hot roller (typically 360° F.). The method of manufacture of the corrugated board otherwise may be conventional or otherwise as may be found suitable. Most preferably, the corrugated board subsequently is formed into boxes.
Corrugated board, as this term is used herein, encompass all flute sizes, including micro-flutes. Micro-corrugated board is used to make, e.g., small boxes such as fast food containers and gift boxes.
The adhesives described herein can be used to bond single- or double-faced boards using any equipment which is presently employed for the preparation of corrugated board. Thus, the adhesive is usually maintained at a temperature of between 20 and 55° C. before its application to the protruding tips of the fluted paper strip. The actual application may be accomplished by the use of glue rolls which are ordinarily employed in most corrugating machines, or one may, if desired, utilize other application methods which may be able to achieve a different distribution of adhesive.
When using a foamed adhesive, the adhesive may be foamed immediately prior to application, or within 72 hours of being foamed, preferable within 24 hours, most preferable within 6 hours of foaming. Following the application of the adhesive to the fluted paper strip, the latter is then brought into immediate contact with the facing board under the influence of heat and pressure, as is well know in the art. A double-faced board may be subsequently prepared by bringing a second facing in contact with the open fluted surface of the single-faced board by the usual procedures.
The invention can be illustrated by the following non-limiting examples.
EXAMPLES
The following examples demonstrate the invention using different starches, different surfactants, and various surfactant usage levels.
In the following examples, which are merely illustrative of the various embodiments of this invention, all parts and percentages are given by weight and all temperatures are in degrees Celsius unless otherwise noted.
The following test procedures were used to evaluate the various adhesives and starches herein used in preparing corrugated board.
Stein-Hall Viscosity
Viscosities were determined using a conventional Stein-Hall cup and measuring the time in seconds, required for 100 ml of the adhesive composition to pass through an orifice having a diameter of {fraction (3/32)} inch.
Bostwick Flow
A Bostwick consistometer [Gardner Supply Company] is preheated to 110° F. using hot tap water. The unit is then dried and place level on the benchtop with the bubble in the specified circle. The gate is locked into place using the L-shaped holding bar. The chamber is filled with foamed adhesive at 100° F. Simultaneously the gate is lifted and the timer started recording the intervals in seconds for the adhesive to reach the specified marks (15, 17, 20, 22, 24 cm).
BROOKFIELD VISCOSITY
Viscosities were determined using a Brookfield Viscometer (model RVT) at 20 rpm and 100° F.
Example 1
All samples of corrugating adhesive were prepared in essentially the same manner, differing only in the precise starches employed and the ratios of components. A representative preparation of an unfoamed adhesive, as prepared in a high shear mixer, is presented below.
A carrier component was prepared by cooking at 45° C. (113° F.) 72.0 g of corn starch in 600.5 g of water. A total of 10.8 g of sodium hydroxide (dissolved in 33.4 g of water) was then added and the system was agitated for 5 minutes. The raw starch component was prepared by post-adding 967.4 g of water at about 35° C. (95° F.), 9.6 g borax (pentahydrate), and 520.0 g corn starch to the carrier while under agitation. The prepared adhesive was subsequently used in the different test procedures.
Example 2
100 mls of adhesives from Example 1 was measured by means of a graduated cylinder and weighed to +/−0.1 gram. Approximately 250 mls of adhesive was added to a Waring blender and the appropriate amount and type of surfactant was added and mixed for 1 minute at high speed. 100 mls of the foamed adhesive is carefully poured into a 100 ml tared graduate and weight recorded to 0.1 gram. The effect of the surfactant (type and concentration) on foam volume and quality is shown the Table 1.
TABLE 1
Surfactant
Void
%
Concentration
Volume
Viscosity
Surfactant
(%)
Maximum
Stability
Change
Sodium Lauryl
0.075
20.1
<12 hours
+77
Sulfate
Lauramide
2.0
40.9
>12 hours
+32
Diethanolamine
Nonylphenoxy
0.8
45.1
<4 days
−4.8
Poly(ethyleneoxy)
ethanol
Monateric 1188M 1
1.6
37.6
>4 days
−36
Monateric 1188M
3.2
61.6
>4 days
+35
Sodium
0.8
42.9
>5 days
+16
Carboxyethyl coco
phosphoethyl
imidazoline
Deceth -4 Phosphate
0.15
36.5
<3 day
+219
Isostearoamphopro-
0.4
29.1
>5 days
+19
pionate
Capryl hydroxyethyl
0.4
36.5
>4 days
−31
iminazoline
Disodium
0.3
32.6
>4 days
12.9
cocamphodipro-
pionate
1 = an amphoteric surfactant (disodium lauramino propionate) commercially available from Uniqema
This example illustrates the need for specific types of surfactant to produce foamed adhesive with good stability and yet not significantly effecting the viscosity. Surfactants capable of solubalizing the highly ionic adhesive without forming a gel are the preferred materials. These tend to have little to no overall charge associated with the surfactant (i.e. non-ionic or amphoteric).
Example 3
The adhesive formulation was prepared as in Example 1 and foamed with the specified surfactant using the method described in Example 2. The flow properties of the foamed adhesive and the effect of surfactant on flow is shown in Table 2.
TABLE 2
Surfactant
Void
Bostwick
Concentration
Volume
Flow
Surfactant
(%)
Maximum
(sec)
None
N/A
8%
3
Sodium Lauryl Sulfate
0.075
20.1
15
Lauramide Diethanolamine
2.00
40.9
46
Nonylphenoxy
0.8
45.1
12
Poly(ethyleneoxy)
ethanol
Monateric 1188M
1.6
37.6
3
Sodium Carboxyethyl coco
0.8
42.9
39
phosphoethyl imidazoline
Deceth -4 Phosphate
0.15
36.5
>120
Isostearoamphopropionate
0.4
29.1
18
Capryl hydroxyethyl iminazoline
0.4
36.1
5
Disodium cocamphodipropionate
0.3
32.6
12
The ability of the adhesive to flow is paramount to the application where the adhesive is required to flow though the corrugating machine and provide good runnabilty. Values greater than about 15 are undesirable and generally hinder the overall machine performance.
Example 4
Using the techniques described in the previous examples, the effect of starch type on foam structure and properties was examined. Two common starch types using in the industry, pearl corn and high amylose corn, were formulated as in Example 1 and foamed using the surfactants shown in Table 3.
TABLE 3
Surfactant
Surfactant
Concentration.
Starch Type
Void Volume
Monamid 150-CW 1
0.4
Pearl Com
59.7
Monamid 150-CW
0.4
High Amylose
51.9
Monawet MO-70R 2
0.4
Pearl Corn
47.7
Monawet MO-70R
0.4
High Amylose
42.4
1 = a nonionic surfactant (capriamide DEA (diethyl amine)) commercially available from Uniqema
2 = an anionic surfactant (dioctyl sulfosuccinate) commercially available from Uniqema
This example illustrates the ability to create a high void volume foam with good stability is independent of the starch type and starch composition.
Example 5
The foamed and non-foamed adhesives prepared in Example 4 using the Monamid 150-CW were used to make corrugated board (singleface web). Samples were made across a range of applicator roll gap settings. Bond quality was determined using methods outlined in TAPPI procedures T 400 and T 821 om-87. The strength of the adhesive bonds was such that manual delamination of the finished board resulted in equivalent bond strengths across the adhesive application range tested.
Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.
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Corrugating adhesives comprising a starch, an alkali, water and a surfactant allow the user to control the amount of adhesive applied, minimize warpage of the final corrugated board and allows equipment to run faster and in a more efficient manner.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a press device. Also it relates to a method for converting a press device in order to increase the linear force in an individual press nip, and to a multiple-nip press device.
[0003] 2. Description of the Related Art
[0004] Press sections on machines for producing fibrous webs are already known in numerous embodiments from the prior art. Different press concepts are realized depending on the number of press nips to be passed through and on the arrangement and construction of the rolls forming said press nips. In the individual press devices the press nips are created by way of two rolls, whereby one of the rolls can be constructed for example as a shoe press roll. From publication EP 1 445 375 A1 there is already known for example a Duo Nipcoflex arrangement. On said arrangement the fibrous web is passed in the region of the press section successively through two press nips which are formed by two press devices in series. The first press device is characterized in that a suction press roll interacts with a shoe press roll. In this case the suction press roll is configured, looking in the vertical direction, as an upper roll and characterized by a rigid, meaning non-flexible rotatable roll cover. To discharge fluid or the water emerging from the fibrous web in the press nip, provision is made on the roll cover for openings which extend from the outer circumference into the roll cover and are discharged out of said cover through channels extending over the width of the roll through the roll cover, whereby the discharging takes place into a suitable end-face receiving box. Also described in this publication is a compact press arrangement, whereby in this case the suction press roll is involved in constructing two press nips, in particular the first and the second press nip arranged successively in the fibrous web running direction. The third roll, which together with the suction press roll forms the second press nip, forms together with another suction press roll a third press nip. The passing of the fibrous web between the individual press nips always takes place on the surface of a roll with no free draw.
[0005] An embodiment of a suction press roll is known from DE 100 22 353 A1. Said embodiment has several channels on the roll cover, whereby each channel has two openings which are arranged offset to each other in the circumferential direction and lead out of the suction press roll, and outside the press nip there is at least one suction apparatus acting on the outer cover face of the roll cover, whereby the distance between the respective openings of the channels in the circumferential direction is selected such that during rotation of the roll cover the suction apparatus always stands in connection to at least a part of the openings momentarily in the press nip via their channels.
[0006] On embodiments of said kind, linear force increases are limited by the shell curvature permissible for the suction press roll cover. If said linear force is to be increased on a press device, it is necessary as a rule in the case of conversions to provide a larger suction press roll diameter, which in part cannot be installed at all or only at great expense in the existing construction space, which is fixed by the presence of additional devices such as ducts, doctor blades and supports, thus making complex conversions necessary or limiting the possibility of a linear force increase.
[0007] What is needed in the art is a suction press roll by way of which, compared to conventional suction press rolls with the same diameter, far higher linear forces can be produced in the press nip in interaction with the mating roll. The inventive solution should also be suitable in this case for retrofitting in existing press devices in order to increase the providable linear force.
SUMMARY OF THE INVENTION
[0008] According to the invention, a linear force increase can be achieved in press devices with suction press rolls of identical or smaller size than conventional suction press rolls by equipping the suction press rolls with a compliance compensator. Said compensator is arranged parallel to and in the longitudinal axis of the suction press roll, meaning it extends over the width of the suction press roll. Decisive for a compliance compensator is the provision of a closed surface. Two basic embodiments are possible according to the invention depending on the embodiment of the roll cover of the suction press roll.
[0009] According to the first basic embodiment of an inventive suction press roll on a press device, the suction press roll includes a perforated roll cover which encloses an interior space, whereby arranged in the interior space is a suction zone which extends at least over a sub-region of the inner circumference of the roll cover in the circumferential direction. According to the invention there is arranged in the inside of the roll cover a shoe press roll which acts or is made to act against the inner circumference of the roll cover of the suction press roll. By way of the shoe press roll it is possible, as the result of its closed cover, to apply, at the inner circumference of the press cover of the suction press roll, a higher bracing force onto said suction press roll over the width, meaning parallel to the longitudinal axis of the suction press roll, such that a counter-force to the force of the mating roll is generated in this region. Hence it is possible to establish an increase of the linear force in the press nip compared to conventional suction press rolls, whereby local or locally different linear force characteristics over the width of the suction press roll can be established depending on the embodiment. The establishment of said force characteristics can be effected in this case steplessly or in steps.
[0010] The shoe press roll in the interior space is arranged in the suction zone. The suction region extends parallel to the longitudinal axis of the suction press roll and, looking in the circumferential direction at the inner circumference, over a part of said circumference, whereby the arrangement of the suction zone is effected such that said zone extends, looking in the running direction of the fibrous web, at the inner circumference from a region in front of the press nip to behind said press nip. In this case the shoe press roll forms together with the suction box a pre-suction compartment, which looking in the fibrous web running direction becomes active in front of the press nip, and a holding zone which becomes active behind the press nip, meaning after the exit from said nip. The press cover of the suction press roll itself is equipped with through-openings which extend from the outer circumference of the press cover as far as the inner circumference, thus creating a connection between the outer circumference and the inner circumference of the suction press roll, in particular the suction zone.
[0011] The shoe press arrangement includes a circulating flexible belt which is pressed by way of a pressing-on unit against the inner circumference of the press cover of the suction roller. On the one hand said circulating belt separates the suction region of the suction roll from the shoe pressing region and on the other hand it creates a suction zone boundary. In this case use is made of the fact that once evacuated suction bores maintain their vacuum in part even when no vacuum is applied. The belt is by comparison impermeable and has a closed cover face.
[0012] Classically bored suction press roll covers can be used as the suction press roll cover. Also, conventional suction press roll covers, which may be available in the case of a conversion, can be used here accordingly for retrofitting. The through-openings extend in radial direction from the outer circumference to the inner circumference, meaning perpendicular to the longitudinal axis of the suction press roll.
[0013] Similarly, the shoe press roll integrated in the suction press roll can be a standard version which needs to be modified only with regard to its installation in the suction press roll. The shoe press roll itself includes a pressing-on unit, preferably with a pressing-on element in the form of a press shoe, whose pressing-on face is constructed to be convex and extends partly in the circumferential direction and further over the width, meaning parallel to the longitudinal direction of the press roll. The bracing can be effected for example by way of piston elements, spring devices or pressure accumulator elements on a support element.
[0014] According to a particularly advantageous embodiment, the flexible press cover of the shoe press roll is made from a wear-free or high wear-resistant material in order to prevent unnecessary replacement of the flexible belt.
[0015] There are no restrictions with regard to the concrete embodiment of the suction box. In this connection it is also possible, with regard to the assignment of the suction device to said suction box, particularly at the side on the end faces, to resort to the possibilities existing from the prior art. The suction box in the interior space of the press roll is sealed from the inner circumference of the press cover by way of suitable sealing devices.
[0016] A second embodiment of the inventive solution consists of combining in one press roll two concepts known from the prior art. This is achieved in that the suction device no longer becomes active in the interior space and hence the fluid-gas mix no longer needs to be passed into the interior space of the press cover in order to be discharged from there but is passed directly through the press cover and evacuated preferably at the side in the region of the end faces. As the result, the inner face describing the inner circumference of the press cover can be kept closed, whereby the closed construction makes it possible to resort here to pressing-on units which enable the linear force to be established in particular over the width or parallel to the longitudinal axis of the press roll. This is achieved in that provision is made for pressing-on units which include one or a multiplicity of pressing-on elements which become active at the inner circumference or exert a pressure on said inner circumference in the direction of the press nip and hence create a bracing force in relation to the mating roll. Here it is possible, depending on the embodiment, to combine different sub-variants with each other.
[0017] According to a first sub-embodiment provision is made for only one bracing unit. According to another embodiment provision is made for pressing-on units of this kind for each individual press nip which can be formed on the suction press roll such that the inventively constructed suction press roll is also suitable for the construction of press nips with a higher establishable linear force. According to a particularly advantageous embodiment provision is made therefore in addition for a second yoke on which piston elements active on the inner circumference can be braced for the purpose of the compliance compensator or a pressing-on element extending over the width. According to a particularly advantageous embodiment, the generatable linear force can be influenced likewise by way of the locally different, in particular zone-based control of the bracing elements, in particular piston elements. As the result, the precision adjustment of the compliance compensator is possible.
[0018] Passing the fluid-gas mix through the roll cover is advantageous in that the suction zone is not integrated in the roll and therefore the roll compliance does not limit the maximum possible linear force. The passage through the roll cover can be effected in various ways. According to a first embodiment, provision is made for openings which extend from the outer circumference of the roll cover in said cover and are discharged out of said cover via central channels or through-bores into the end-face regions and passed on from there via separate devices, meaning outside the roll. Another possibility, instead of connecting the bores via a central bore to a suitable suction device, is to route the bores through the press cover such that during operation in press devices the opening on the surface, meaning on the outer cover is always in the press nip and the second opening is in a region outside the press nip, whereby in this case a device for evacuation should also be provided.
[0019] The mating rolls of the inventively constructed suction press rolls can be rolls of various types of construction. According to a first embodiment, the mating roll can be constructed as a so-called Nipcoflex roll, meaning an extended press nip is obtained by passing a flexible roll cover over a concavely/convexly formed press shoe. According to another embodiment, the mating roll can also be a solid cover roll. This applies analogously also for the second embodiment.
[0020] By way of the inventive solution it is possible to exert an effect, in the press nip looking over the width of the machine, selectively on corresponding linear force increases and their repercussions and to actively control said repercussions.
[0021] According to a particularly advantageous further aspect, the inventive solution is used for suction press rolls on press devices for which provision is made for at least two suction press rolls of the same type on one press device. Compared to conventional suction press rolls without an inventive compliance compensator, inventive suction press rolls with identical or smaller diameter can be used for the same establishable line forces, which means that a simple replacement of conventional suction press rolls by inventively constructed suction press rolls is also possible for effecting a linear force increase.
[0022] The inventive solution can be used on a press apparatus, in particular a multiple-nip press apparatus including a first press device and a second downstream press device. The first press device includes a first roll, which together with a second roll as mating roll forms a first press nip and together with a central roll forms a second press nip downstream from the first press nip in the fibrous web running direction, and a third press nip which is constructed between the central roll and a third roll. Downstream from the first press device is a second press device which includes two rolls forming a further fourth press nip. In this case the first roll of the first press device and one roll of the second press device are constructed as suction press rolls, preferably according to the invention. The suction press rolls are identical, as the result of which they can be exchanged and the stocks of spare parts reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
[0024] FIG. 1 shows in a schematic simplified representation a press device with an inventively constructed suction press roll according to the first basic embodiment with an integrated shoe press roll;
[0025] FIG. 2 shows in a schematic simplified representation a press device with an inventively constructed suction press roll according to a second basic embodiment with an integrated compliance compensator;
[0026] FIG. 3 shows a further embodiment of an inventive suction press roll according to the second basic embodiment; and
[0027] FIG. 4 shows an application of inventively constructed suction press rolls with a multiplicity of consecutive press nips.
[0028] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now to the drawings, and more particularly to FIG. 1 , there is shown in a schematic simplified representation based on a press device 1 , including a first press roll 2 and a second press roll 3 which together form a press nip 4 , a particularly advantageous inventive embodiment of a suction press roll 5 , which in the case shown conforms to the upper first press roll 2 in the installation position, with an integrated shoe press roll 6 arranged eccentrically to the suction press roll 6 . A fibrous web (not shown here) is passed together with at least one felt belt through the press nip 4 . In this case the suction press roll 5 acting as the first roll 2 has a rigid, meaning stable or inflexible perforated roll cover 7 which encloses an interior space 8 of the suction press roll 5 in the circumferential direction. The roll cover 7 is characterized by an outer circumference 9 and an inner circumference 10 . In order to be able to resort to conventional roll covers, meaning a roll cover 7 with a perforation which is formed by through-openings which are orientated in radial direction and extend from the outer circumference 9 to the inner circumference 10 , and thus enables a connection between the surroundings and the interior space 8 , provision is made in the interior space 8 for at least one suction zone S which extends in the circumferential direction over at least a sub-region of the inner circumference 10 of the roll cover 7 and is formed in the simplest case by a positionally stable or stationary suction box 12 . Said suction box is sealingly supported against the inner circumference 10 . The discharging of the liquid-air mix sucked in via the through-openings 11 can be effected in this case in the direction of the end faces. According to the invention, a shoe press roll 6 is arranged in the interior space 8 . Said shoe press roll is provided at the inner circumference 10 in the installation position in the region of the press nip 4 . The shoe press roll 6 includes a flexible circulating belt 13 and a pressing-on unit 15 arranged in the interior space 14 enclosed by the belt 13 , including at least one or preferably a multiplicity of pressing-on elements 16 which with their surface forming a pressing-on face 18 and orientated toward the inner circumference 17 of the belt 13 can be pressed against said inner circumference. Preferably the pressing-on face 18 is constructed to be convexly curved. Hence the pressing-on unit 15 also acts indirectly against the inner circumference 10 of the roll cover 7 of the suction press roll 5 , as the result of which the linear pressure in the press nip 4 is increased via the shoe press roll 6 . The pressing-on unit 15 includes, as already explained, preferably a pressing-on element 16 in the form of a press shoe 19 which braces itself on a stationary supporting element 20 via device 21 for generating the required pressing force, for example in the form of a piston series or at least one, preferably a multiplicity of pressurized compartments. The pressure at the pressing-on element 16 is established via the device 21 between the press shoe 19 and the supporting element 20 . Said establishing of the pressure can be effected over the width, meaning parallel to the longitudinal axis L of the suction press roll 5 steplessly or in steps as well as over the complete width and also on a zone basis. The suction box 12 is arranged such that it quasi encloses the shoe press roll 6 , thereby forming a pre-suction compartment 22 and a holding zone 23 . The circulating belt 13 , which is impermeable to liquid and pressure, separates the suction region S of the suction press roll 5 from the region of the shoe press roll 6 and also creates a suction zone boundary. In this case use is made of the fact that a once evacuated suction bore in the form of the through-openings 11 maintains its vacuum in part even when no vacuum is applied. The sealing of the suction box 12 against the inner circumference 10 is effected by way of sealing devices 24 , in particular in the form of sealing rails 25 . The suction press roll 5 is arranged in the press device 1 , looking in the vertical direction, preferably above the second roll 3 . Other arrangements are likewise conceivable. Fluid is picked up via the through-openings 11 , which extend from the outer circumference 9 to the inner circumference 10 , is sucked into the suction box 12 and discharged out of said box. In this case the region on the inlet side between the suction box 12 and the shoe press roll 6 forms a pre-suction compartment 22 while the region of the suction zone S arranged on the outlet side of the press nip 4 acts as a holding zone 23 after the passage through the press nip. The region facing away from the press nip 4 is unaffected by the suction box 12 . The suction box 12 extends in this case over a part of the inner circumference 10 , whereby said sub-region extends from a region in front of the press nip 4 to behind the press nip 4 . According to a particularly advantageous embodiment, the suction region extends in this case preferably over at least a quarter, in particular preferably over half of the inner face of the inner circumference 10 in the circumferential direction.
[0030] As already explained, the linear force in the press nip 4 can be varied by the device 21 . Preferably a device for controlling the pressing-on force as a function of the linear force to be established is assigned to said device. With regard to the construction of the shoe press roll 6 it is possible to resort to conventional construction concepts. The press shoe 19 can be lubricated in this case hydrostatically and/or hydrodynamically. Actuation of the pressing-on elements is effected preferably hydraulically. Other embodiments are likewise possible.
[0031] FIGS. 2 and 3 show in a schematic and highly simplified representation based on a perspective view a first embodiment of a press device 1 with a compliance compensator according to the second basic embodiment. Here too the press device 1 includes two rolls, a first roll 2 and a second roll 3 , whereby the first roll 2 is constructed as a suction press roll 26 and comprises a rigid roll cover 27 . Both press rolls, the first press roll 2 and the second press roll 3 , form together a press nip 4 . The mating roll in the form of the second roll 3 can be constructed as various types. Said mating roll can be constructed as a shoe press roll with a flexible press cover with at least one pressing-on unit with a curved surface or as a solid roll 6 . For example, the first roll 2 is constructed as an evacuated roll in the form of the suction press roll 26 . Said suction press roll has, according to a first variant, on the surface of the roll cover 27 openings, in particular bores 28 , which can be evacuated at the side on the end face of the roll cover 27 . For this purpose provision is made in the simplest case for a multiplicity of bores 28 , which extend preferably over the entire width of such a press device 1 , meaning transverse to the machine direction when used on machines for producing fibrous webs, and can be distributed preferably also over the circumference. Assigned to a majority of such bores is a central suction channel 29 which interconnects said bores 28 and is coupled to a suction device 30 in the region of the end face of the first press roll 2 , which is shown here only schematically in order to illustrate the function. The bores 28 extend in this case only in the roll cover 27 , meaning from the outer circumference 31 in the direction of the inner circumference 32 of the roll cover 27 but not through it, and the central suction channel 29 extends through the roll cover thickness d 27 of the roll cover 27 . Hence there is no connection between the bores 28 and an interior space 33 enclosed by the roll cover 27 . Hence the inner face describing the inner circumference 32 of the roll cover 27 is preserved as a closed face so that said face can brace itself evenly over the machine width on at least one supporting element 35 . For this purpose the first press roll 2 includes in addition a pressing-on unit 34 which is arranged within the roll cover 27 , in particular in the interior space 33 , and braces itself on the supporting element 35 . The pressing-on unit includes at least one, preferably several pressing-on elements 36 , preferably in the form of piston elements 37 , which are movable in relation to the face formed by the inner circumference 32 , preferably perpendicular thereto, and are pressable against the inner circumference 32 . The piston elements 37 are arranged parallel to the longitudinal axis L of the suction press roll 26 , whereby said piston elements are controllable individually or jointly in groups. Through the inventive combination of an end-face evacuation and routing of the medium to be evacuated in the press cover 27 , meaning without routing through the interior space 33 and evacuation from said space, the entire interior space 32 is available as a closed face on which the pressing-on elements 36 , in particular piston-type bracing elements, can become active. It is thus possible in addition to create on embodiments of multiple-nip press devices for example a further second press nip 38 at the first press roll 2 , whereby the bracing and the region of increased linear force is created by way of a further second pressing-on unit 39 which is arranged downstream from the first press nip 4 in the belt running direction or fibrous web running direction during operation of the press device 1 at the outer circumference of the roll cover 27 . The further pressing-on unit 39 serves in this case for bracing in the press nip 38 . Here too the pressing-on unit 39 includes either a multiplicity of or one pressing-on element 40 , preferably in the form of a piston element 48 . FIG. 2 shows in this case an example on which optionally another yoke 41 is provided as a support element for the pressing-on unit 39 . Said pressing-on unit has likewise preferably a multiplicity of piston elements which with their face facing the inner circumference 32 of the roll cover 27 become active at the inner circumference 32 of the roll cover 27 . Other embodiments are possible. A compliance compensation can be realized through actuation of the pressing-on elements. Through the embodiment shown in FIG. 2 it is possible furthermore to provide a high degree of dewatering at the same time as a very high generatable linear force in the press nip. FIG. 2 shows in this case for example one possibility with a second supporting element 35 and a second pressing-on unit 39 in addition. Other embodiments are possible.
[0032] FIG. 3 shows analogously a press device 1 according to the second basic embodiment of the inventive solution with a pressing-on unit 34 which becomes active at the inner circumference 32 of the roll cover 27 , which is constructed as a rigid, meaning non-flexible and hence dimensionally stable press cover. In the region of the pressing-on face it is possible in this case to generate very high linear forces in the press nip 4 . On this embodiment the suction press roll 26 in the roll cover 27 has several channels 42 , whereby each channel 42 has at least two openings 43 , 44 which are arranged offset to each other in the circumferential direction and lead out of the suction press roll 26 . The bores extend in this case not in radial direction, as shown in FIG. 2 , but at an angle through the suction roll cover 27 , whereby respectively one of the openings 43 , 44 is connected in a functional position to the press nip 4 while the other interacts with a suction device 30 arranged outside the suction press roll 26 . Here too provision is made in the interior space 33 of the first roll 2 for at least one pressing-on unit 34 which can be constructed analogously to the one shown and described in FIG. 2 .
[0033] The second embodiment is characterized by a combination of the known characteristics of a rigid roll cover with openings for the purpose of evacuating or routing the fluid-gas mix through the cover 27 and an arrangement of a pressing-on unit 34 which becomes active at the inner circumference 32 of the roll cover 27 and braces said roll cover via said inner circumference on the supporting element, in particular yoke.
[0034] FIGS. 1 to 3 present possible embodiments of the suction press rolls. FIG. 4 presents a particularly advantageous use of inventively constructed suction press rolls 5 or 26 in a multiple-nip press apparatus 45 in the form of a Duocentri Nipcofiex press apparatus. FIG. 4 shows in a schematic and highly simplified representation a detail from the press apparatus 45 including a first press device 46 for forming three successively passable press nips together with a first roll 2 or a suction press roll 5 or 26 according to the first or the second embodiment, which together with a further second roll 3 as mating roll forms a first press nip 4 . In addition provision is made for a central roll 47 , which together with the first roll 2 constructed as a suction press roll 5 or 26 forms a further second press nip 38 . In turn the central roll 47 forms together with a roll 49 a third press nip 50 . The fibrous web F is passed between the first press nip 4 and the third press nip 50 respectively along the outer circumference on the individual press rolls 2 , 3 , 47 , 49 , whereby the passing is always performed together with a felt belt, at least in the first and third press nip 4 . In the illustrated case the passing of the fibrous web F is effected in the first press nip 4 between two felt belts FB 1 and FB 2 , whereby the first felt belt FB 1 enwraps the suction press roll 26 , 5 and the second felt belt FB 2 as bottom belt enwraps the second roll 3 . In addition, the fibrous web F is passed directly along the surface of the central roll 47 and on said surface through the third, single-felted press nip 50 . After passing through the third press nip 50 the fibrous web F is passed through a further second, preferably double-felted press device 51 between the felt belts FB 3 and FB 4 . The press device 51 is again constructed such that it includes a roll in the form of a press roll 5 or 26 according to the first embodiment or the second embodiment, which together with a mating roll 52 forms a fourth press nip 53 . FIG. 4 thus describes a Duo Nipcoflex press arrangement with a downstream fourth press nip. The rolls 3 and 52 can be constructed as solid cover rolls or shoe press rolls. Preferably the first roll 2 and a roll of the second press device are identically constructed as suction press rolls in order to minimize stocks.
[0035] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
LIST OF REFERENCE NUMERALS
[0000]
1 Press device
2 First press roll
3 Second press roll
4 Press nip
5 Suction press roll
6 Shoe press roll
7 Roll cover
8 Interior space
9 Outer circumference
10 Inner circumference
11 Through-openings
12 Suction box
13 Belt
14 Interior space
15 Pressing-on unit
16 Pressing-on element
17 Inner circumference
18 Pressing-on face
19 Press shoe
20 Supporting element
21 Device for generating a pressing-on force
22 Pre-suction compartment
23 Holding zone
24 Sealing devices
25 Sealing rail
26 Suction press roll
27 Press cover
28 Bores
29 Central suction channel
30 Suction device
31 Outer circumference
32 Inner circumference
33 Interior space
34 Pressing-on unit
35 Supporting element
36 Pressing-on element
37 Piston elements
38 Second press nip
39 Second pressing-on unit
40 Pressing-on element
41 Yoke
42 Channel
43 Opening
44 Opening
45 Press apparatus
46 First press device
47 Central roll
48 Piston element
49 Roll
50 Third press nip
51 Press device
52 Mating roll
53 Press nip
F Fibrous web
S Suction zone
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This invention relates to a press device with a suction press roll. According to the invention, a linear force increase can be achieved in press devices with suction press rolls of identical or smaller size than conventional suction press rolls by equipping the suction press rolls with a compliance compensator. Said compliance compensator is arranged parallel to the longitudinal axis of the suction press roll in said suction press roll. Different concepts are possible depending on the roll cover construction and the arrangement of the suction box, whereby the one first embodiment is characterized by the integration of a shoe press roll in the suction press roll. A second embodiment is characterized by the combination of a routing of connection channels between the press nip and the suction box through the roll cover with an integrated compliance compensator in the interior space enclosed by the roll cover.
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This is a continuation of Ser. No. 07/926,968, filed Aug. 7, 1992, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a screen suitable for use in a profeed washer and other machine or equipment used for separating a mixture of liquid and sol id materials into liquid and solid.
In the paper manufacturing industry, a profeed washer is used for washing pulp mat which is a raw material for paper. A conventional profeed washer is made by providing a wire-netting on a circumferential surface of a hollow rotary drum. Liquids raw material for paper including pulp is supplied over this rotary drum and washed. After washing, liquid in the raw material fails to the inside of the rotary drum, passing through the wire-netting and is collected from the inside of the rotary drum whereas pulp fiber is trapped by the wire-netting and is moved by the rotation of the rotary drum and is collected at a pulp collecting section.
In the conventional profeed washer including a rotary drum provided with a wire-netting, fiber in the raw material for paper is trapped in a desired manner by the wire-netting and is smoothly collected. The wire-netting, however, has the disadvantage that the diameter of metal wire constituting the wire-netting is relatively small and hence the wire-netting is vulnerable to corrosion and wear with resulting insufficiency in durability. This poses a serious problem in the conventional profeed washer.
Machines and equipments other than a profeed washer using a moving body such as a rotary drum provided with a wire-netting for separating mixture of solid and liquid into solid and liquid face with the same problem of lack in durability of the wire-netting used in these machines and equipments.
It is, therefore, an object of the invention to solve the above described problem in a machine or equipment such as a profeed washer using a moving body provided with a wire-netting for separating solid from liquid by providing a novel element which, instead of wire-netting, can collect solid effectively and yet has sufficient durability.
SUMMARY OF THE INVENTION
For achieving the above described object of the invention, a screen according to the invention is made of a plurality of screen wires each of which is formed on the facial surface thereof with a plurality of projections and/or depressions at proper interval. Such screen may be further formed on the side surface thereof with a plurality of projections at a predetermined interval.
A screen made of a plurality of screen wires such as wedge wires arranged in parallel with a slit of a predetermined width defined between respective adjacent screen wires is well known. This type of screen generally has screen wires of a much larger diameter than a wire of wire-netting and hence has a much higher durability. As a result of a test for using such wire screen instead of wire-netting on a rotary drum, however, it has been found that the facial surface (i.e., the surface which comes into contact with raw material for paper when used in a profeed washer) of the screen wire of such wire screen is so flat and smooth that, when the wife screen is provided on the rotary drum, a substantial portion of solid including pulp fiber supplied onto a rising screen portion of the rotating rotary drum is not trapped on the facial surface of the screen wires but slips down along the surface of the screen. As a result, it has been found that ratio of collection of solid at a solid collecting section is very poor as compared with a case of using the wire-netting on the rotary drum.
According to the invention, projections and/or depressions are formed at proper interval on the facial surface of each screen wire constituting the screen and it has been found that these projections or depressions surprisingly function to trap solid such as fiber in raw material for paper sufficiently and thereby enable the solid to be moved with a movement of a moving body such as a rotary drum to a predetermined solid collecting section as effectively as wire-netting. Thus, according to the invention, a novel screen element for a profeed washer or like device having a solid trapping ability which is as high as wire-netting and durability which is much larger than wire-netting can be provided.
The invention is applicable not only to a rotary body such as a profeed washer but also to stationary type screens and filters such as a well screen in which the screen according to the invention is expected to trap gravel filled in the well bore effectively on the screen surface.
Preferred embodiments of the invention will be described below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is perspective view of an embodiment of the screen according to the invention;
FIG. 2 is a perspective view of a method for forming projections on the screen of FIG. 1;
FIG. 3 is a perspective view of another embodiment of the screen according to the invention;
FIG. 4 is a perspective view of a method for forming depressions in the screen of FIG. 3;
FIG. 5 is a plan view of another embodiment of the screen according to the invention; and
FIG. 6 is a perspective view showing a rotary drum of a profeed washer on which the screen according to the invention is provided. FIG. 7 is perspective view of an embodiment of a screen of the invention where one wire has square depressions and the other wire has round depressions.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a perspective view showing an embodiment of the invention. A screen 1 of this embodiment includes a plurality of screen wires 2 made of wedge wires which are arranged in parallel with slits 3 being formed between respective adjacent screen wires 2. These screen wires 2 are welded to support rods 4 crossing the screen wires 2.
On the facial surface of the respective screen wires 2 are formed, at a predetermined interval, projections 5 which extend in lateral direction of the screen wire 2. These projections 5 can be formed by, for example, rotating, as shown in FIG. 2, a shape forming wheel 6 which have depressions 6a conforming to the shape of the projections 5 formed on the periphery thereof at the same interval as the interval of the projections 5 in the direction of arrow A and feeding the screen wire 2 in the direction of arrow B so as to cause the screen wire 2 to be in meshing engagement with the shape forming wheel 6.
FIG. 3 is a perspective view showing another embodiment of the invention. A screen 1 includes, as in the embodiment of FIG. 1, a plurality of screen wires 2 arranged in parallel with slits 3 defined between respective adjacent screen wires 2 and also includes support rods 4 to which the screen wires 2 are welded. The screen 1 of this embodiment differs from the screen 1 of FIG. 1 in that, instead of the projections, depressions 7 extending in lateral direction of the screen wire 2 are formed on the facial surface of each screen wire 2 at a predetermined interval. These depressions 7 can be formed by, for example, rotating, as shown in FIG. 4, a shape forming wheel 8 which have projections 8a conforming to the shape of the depressions 7 formed on the periphery thereof at the same interval as the interval of the depressions 7 in the direction of arrow A and feeding the screen wire 2 in the direction of arrow B so as to cause the screen wire 2 to be in meshing engagement with the shape forming wheel 8.
FIG. 5 is a plan view showing another embodiment of the invention. Each screen wire 2 of the screen of this embodiment is formed on the facial surface thereof with depressions 7 in the same manner as in the embodiment of FIG. 3 and Is additionally formed on the side surface thereof with bulging portions 9 which are formed by bulging out of material of the screen wire 2 on sides of the bottom of the depressions 7 when the shape forming wheel 8 is in meshing engagement with the screen wire 2. Since these bulging portions 9 are projecting in the slits 3, a part of a solid such as fiber which has entered the slits 3 is caught by the bulging portions 9 and, as a result, the ratio of trapping solid by the screen is increased.
FIG. 6 shows an example of profeed washer in which the screen 1 according to the invention is provided on the circumferential portion of a rotary drum 10. As this rotary drum 10 is rotated in the direction of arrow C and raw material for paper is supplied over the upper portion of the rotary drum 10, liquid portion of the raw material falls through the slits 3 of the screen 1 to the inside of the rotary drum 10 whereas fiber portion of the raw material is trapped by the projections 5 or depressions 7 (only a portion thereof is shown in FIG. 6) formed on the facial surface of the screen wires 2 and, as the rotary drum 10 is rotated, carried to a predetermined fiber collecting section (not shown) and collected therein.
In the illustrated embodiments, the projections 5 and depressions 7 are formed in the shape of a triangular cross section. The cross section of the projections 5 and the depressions 7 is not limited to this but it may be of one of other shapes such as semi-circular and square cross sections. The projections 5 and depressions 7 may extend obliquely instead of extending in lateral direction of the screen wire 2. The projections 5 and depressions 7 may be formed partially in lateral direction of the screen wire 2 instead of being formed over the entire width of the screen wire 2.
In the illustrated embodiments, the projections 5 and the depressions 7 of the screen wires 2 are aligned laterally for all of the screen wires 2. Alternatively, the projections 5 and the depressions 7 may be disposed in a staggered arrangement in the lateral direction of the screen wires 2.
As the screen wire 2, not only a wedge wire but al so other screen wires having any desired cross sections such as circular, square, rhombic and hexagonal cross sections may be used.
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A screen suitable for use in a device for separating solid from liquid is made of a plurality of screen wires each of which is formed on the facial surface thereof with a plurality of projections or depressions. The screen may be additionally formed on the side surfaces thereof with a plurality of projections. The screen can effectively trap solid by the projections or depressions formed on the surfaces thereof.
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[0001] This application claims benefit of the 22 Jul. 2005 filing date of U.S. provisional patent application No. 60/702,010.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of materials technology, and more particularly to ceramic matrix composite materials.
BACKGROUND OF THE INVENTION
[0003] The current generation two-dimensional laminate porous oxide ceramic matrix composites (CMC) have relatively low interlaminar strength properties. Three-dimensional CMC materials have higher interlaminar strength; however 3D materials are more expensive and have not yet been fully developed for commercial applications, such as for use in the hot gas path of a gas turbine engine. It is known to improve the interlaminar strength of 2D CMC materials by further densifying the porous matrix in a conventional manner with additional sinterable phase matrix material. Unfortunately, as porosity is decreased in such materials, there is a corresponding reduction in in-plane strength (reduced by more than half in some embodiments) and the material becomes brittle as the interconnection between the matrix and the fibers becomes stronger.
[0004] It is known in both oxide and non-oxide CMC materials to apply an interface coating material to the fiber prior to matrix formation in order to decrease the fiber-matrix interconnection. The interface material functions to deflect cracks forming in the matrix material away from the fibers, thereby preserving the fiber network strength and the resulting in-plane mechanical properties. Unfortunately, fiber tows that are coated with interface coating materials are more difficult and expensive to weave and the coatings tend to spall off of the fibers during weaving. Furthermore, no viable process has yet been demonstrated for solution coating of filaments in fiber form, since close-packed fibers in cross-over points are difficult to coat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The invention is explained in the following description in view of the drawings that show:
[0006] FIG. 1 is a schematic illustration of an improved ceramic matrix composite material at a stage of manufacturing wherein ceramic fibers are surrounded by a first phase of a ceramic matrix material. At this stage of manufacture the material is known in the Prior Art.
[0007] FIG. 2 is the material of FIG. 1 after further processing to apply a diffusion barrier layer over the first matrix phase and fibers.
[0008] FIG. 3 is the material of FIG. 2 after further matrix densification steps.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The present inventors have developed innovative processes and resulting novel ceramic matrix composite materials that exhibit improved interlaminar strength without the usual corresponding degree of reduction of other mechanical properties. These improvements are achieved with a matrix material that includes at least two phases separated by a diffusion barrier. The diffusion barrier is effective to limit sintering between the two phases and optionally between one of the matrix phases and the encased ceramic fibers. In one exemplary embodiment, a known oxide/oxide CMC material sold under the brand name A/N720-1 by COI Ceramic, Inc. of San Diego, Calif. is further densified in a bisque fired state with a second matrix phase infused by conventional matrix densification steps only after the porous matrix has been infused with a monazite diffusion barrier material effective to coat exposed surfaces of the bisque fired matrix and embedded fibers. A/N720-1 material utilizes Nextel® N720 fibers (85% alumina and 15% silica in the form of mullite and alumina polycrystals) disposed in an alumina matrix, and the second matrix phase was also selected to be alumina. The monazite diffusion barrier material used in the exemplary embodiment was a lanthanum phosphate (LaPO 4 ). The resulting densified CMC material exhibited fully-fired short beam shear (SBS) in-plane shear strength that was increased by 21% over the known A/N720-1 material not having the densified matrix, and flatwize tensile strength (FWT) interlaminar strength that was increased by 64% over the known material. These improvements were achieved with a corresponding decrease of only 16% in the in-plane tensile strength when compared to the known material. Similar, although less dramatic, improvements have been obtained in test samples of other oxide/oxide CMC materials.
[0010] The process for forming the improved CMC material 10 of the exemplary embodiment is illustrated schematically in FIGS. 1-3 , where the CMC material 10 includes ceramic fibers 12 disposed in a ceramic matrix 14 . The matrix 14 of the exemplary embodiment includes a plurality of non-sinterable oxide shapes 16 that provide a degree of dimensional stability to the material 10 . The non-sinterable oxide shapes 16 , which in the exemplary embodiment are dimensionally stable mullite spheres, are interconnected by a sinterable binder material of alumina particles 18 to define the porous matrix 14 . Together, the non-sinterable mullite particles 16 and binding alumina particles 18 may be considered a first matrix phase 19 . The term matrix phase as used herein is meant to include a single type of particles only, or a variety of particle types, or an infused layer of material only, or both particles and infused material together. FIG. 1 represents the inventive material 10 at a bisque fired stage of manufacture that is known in the art.
[0011] FIG. 2 illustrates the material of FIG. 1 after it has been further processed to infuse a diffusion barrier material 20 into the porous matrix material 14 . The diffusion barrier material 20 may coat both the first matrix phase 19 , as illustrated at 20 ′ and the exposed surfaces of the fiber as illustrated at 20 ″. The diffusion barrier material 20 may be infused into the matrix 14 as a precursor material that is subsequently heated to form the diffusion barrier material by processes known in the art.
[0012] FIG. 3 illustrates the material of FIG. 2 after it has been further processed through one or more matrix densification steps to deposit a second phase of matrix material 22 to at least partially fill voids in the matrix 14 . The material is then final fired to achieve the improved mechanical properties cited above. The second phase of alumina matrix material may be introduced as aluminum hydroxychloride and then bisque fired to form alumina through one or more cycles as is known in the art to achieve a desired degree of porosity in the matrix 14 . Some voids 24 will remain in the matrix 14 , and in various trials the exemplary embodiment the improved material 10 exhibited a density in the range of 2.89-2.90 g/cc and an open porosity in the range of 18.75-19.65%. This compares to control samples of prior art A/N720-1 material exhibiting a density in the range of 2.86-2.87 g/cc and an open porosity in the range of 19.92-20.06%. Importantly, the diffusion barrier resides between the two matrix phases 19 , 22 , thereby preventing them from bonding together during sintering. Keeping the two matrix phases from sintering together allows for increased matrix density without increased sintering activity between the two matrix phases. In a secondary role, the diffusion barrier 20 also resides between the fibers 12 and the second matrix phase 22 and also prevents them from sintering together.
[0013] The diffusion layer compositions may include compositions that form weak debond layers such as traditionally used as fiber/matrix interface coatings; for example monazites, xenotimes, germinates, tungstates, vanadates, zirconia, hafnates, or other material having compatible chemistries and activation energy levels to function effectively as a diffusion barrier for the matrix material. Not only does the present invention provide higher interlaminar strength without a correspondingly high reduction in strain tolerance, notch insensitivity and strength in other material directions, but it also provides a material with higher thermal conductivity, thereby lowering stresses within the material resulting from thermal transients. A further advantage of the diffusion barrier between matrix phases is the prevention of matrix grain growth and continued densification during service. It is known that continued sintering of the alumina particles during service will result in eventual loss of composite ductility and strength. The diffusion barrier of the present invention coats the exposed particle surfaces, thereby preventing sintering associated with surface diffusion.
[0014] While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. For example, the exemplary embodiment of the invention is described as an oxide/oxide CMC material; however other embodiments may include non-oxide/non-oxide or oxide/non-oxide materials. The invention may further be applied to both 2D and 3D laminates. It is believed that a doubling of interlaminar strength and a 25% increase in through-thickness thermal conductivity may be achievable with minimal loss of in-plane strain-to-failure for 2D laminate embodiments of this invention. Even greater improvements in performance may be achievable for 3D laminate embodiments of the invention. Such improvements are significant in applications requiring a tight radius in a constrained geometry, such as when the material 10 is used in a vane 30 of a gas turbine engine. Numerous variations, changes and substitutions may be made without departing from the invention herein. For example, more than two phases of matrix material may be used with corresponding diffusion barriers being disposed between the respective adjacent phases, as is illustrated schematically at region 32 of FIG. 3 . The various matrix phases 19 , 22 , 34 may be the same material or different materials, and the various diffusion barriers 20 , 36 may be the same material or different materials. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
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A ceramic matrix composite (CMC) material ( 10 ) with increased interlaminar strength is obtained without a corresponding debit in other mechanical properties. This is achieved by infusing a diffusion barrier layer ( 20 ) into an existing porous matrix CMC to coat the exposed first matrix phase ( 19 ) and fibers ( 12 ), and then densifying the matrix with repeated infiltration cycles of a second matrix phase ( 22 ). The diffusion barrier prevents undesirable sintering between the matrix phases and between the second matrix phase and the fibers during subsequent final firing and use of the resulting component ( 30 ) in a high temperature environment.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CN2011/077022, filed on Jul. 11, 2011, which claims priority to International Application No. PCT/SE2010/000216, filed on Sep. 4, 2010, both of which are hereby incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] The technical field of multi-user wireless communications provides relevant art of technology for this specification of an invention. This may also be the case for a technical field of surface covering wireless communications, channel resource allocation, orthogonal frequency division multiplex or multiple access, or recursive methods and systems, where a recursion is based on an evolutionary process.
BACKGROUND
[0003] Wireless communications provide a means of communicating across a distance by means of electromagnetic signals. In an environment of plural electrical signals the signals may interfere, thereby rendering the signals difficult to detect reliably. This may particularly be the case in multi-user systems where signals of different users may interfere. By allocating signals of different users to different channels or channel resources, such interference may be reduced or eliminated.
[0004] Due to the limited availability of channel resources, e.g. in terms of radio frequency spectrum or light spectrum, to cover a surface may require some of the channel resources to be re-used at different locations along the covered surface. For this purpose available channel resources may be divided into one or more groups. Further, the surface to be covered by wireless services or communications is divided into a plurality of smaller, preferably but not necessarily non-overlapping, areas. These smaller areas are referred to as cells, and are generally defined in terms of the wireless coverage, such as radio coverage of a channel group of a particular radio transmitter of the cell, where the transmitter forms part of a base station providing wireless coverage of the cell.
[0005] The number of groups is associated with particular reuse-patterns of preferred allocation of channel groups to the various cells (or part of cell) covering the surface of interest. Such reuse is referred to as K-reuse, where K represents the number of groups of such reuse.
[0006] 3GPP TR 25.814 V7.1.0, Technical report; 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA) (Release 7), France, September 2006, is related to the 5 technical report for physical layer aspect of the study item “Evolved UTRA and UTRAN” and considers in sections 7.1.2.6 and 9.1.2.7 “Inter-cell interference mitigation” three basic approaches to inter-cell interference mitigation:
[0007] Co-ordination/avoidance
[0008] Inter-cell-interference randomization, and
[0009] Inter-cell-interference cancellation.
[0010] For the uplink, also
[0011] Frequency domain spreading
[0012] is considered.
[0013] In addition, the use of
[0014] Beam-forming antenna solutions at the base station
[0015] is a general method that can also be seen as a means for downlink inter-cell-interference mitigation.
[0016] As regards the coordination/avoidance, the 3GPP technical report concludes that the common theme of inter-cell-interference co-ordination/avoidance is to apply restrictions to the resource management (configuration for the common channels and scheduling for the non common channels) in a coordinated way between cells. These restrictions can be in the form of restrictions to what time/frequency resources are available to the resource manager or restrictions on the transmit power that can be applied to certain time/frequency resources. Such restrictions in a cell will provide the possibility for improvement in SIR, and cell-edge data-rates/coverage, on the corresponding time/frequency resources in a neighbor cell.
[0017] In the 3GPP technical report, for static interference co-ordination reconfiguration of the restrictions is done on a time scale corresponding to days. The inter-node communication is very limited (set up of restrictions), basically with a rate of in the order of once per day, whereas for semi-static interference co-ordination, reconfiguration of the restrictions is done on a time scale corresponding to seconds or longer. Inter-node communication corresponds to information needed to decide on reconfiguration of the scheduler restrictions (examples of communicated information: traffic-distribution within the different cells, uplink interference contribution from cell A to cell B, etc.) as well as the actual reconfiguration decisions. For semi-static interference co-ordination, signaling rate is in the order of tens of seconds to minutes.
[0018] Arne Simonsson, “ Frequency Reuse and Intercell Interference Co - ordination in E - UTRA”, VTC 2007-Spring, IEEE 65th, 22-25 Apr. 2007, pp. 3091-3095, evaluates some basic schemes of intercell interference co-ordination by means of simulations. Anticipating a uniform user distribution, it is concluded that of the static schemes 1-reuse performs the best for wideband services and that a dynamic scheme is required to improve compared to 1-reuse.
[0019] Wang et al., “ An Interference Aware Dynamic Spectrum Sharing Algorithm for Local Area LTE - Advanced Networks”, VIC 2009-Fall, 2009 IEEE 70th, 20-23 Sep. 2009, discloses a dynamic spectrum sharing algorithm to minimize inter-cell interference. The algorithm operates in a self-organized manner without the need of any centralized control and is evaluated in the context of LTE-Advanced Downlink transmission. Average cell throughput, average cell load, cell edge user throughput and spectrum allocation interval are used as performance metrics for the evaluation.
[0020] D. Renaud and A. Caminada, “ Evolutionary Methods and Operators for Frequency Assignment Problem”, Speed Lip Journal 11(2), pp. 27-32, Proceedings 22nd Workshop, 18-19 Sep. 1997, briefly describes evolutionary methods in a context of interference minimization. Renaud and Caminada state that a frequency assignment problem may be understood as an optimization problem where the subject is to minimize co5 channel and adjacent-channel interference and further states that the optimization problem may be reduced to the graph coloring problem which is an NP-complete combinatorial problem. For the genetic coding of their evolutionary method, a chromosome representation for the frequency assignment problem is illustrated, where the length of the chromosome is equal to the total traffic of the network and one chromosome in each gene corresponds to a particular frequency in a particular cell.
[0021] Y. Xiang et al. “ Inter - cell Interference Mitigation through Flexible Resource Reuse in OFDMA based Communication Networks”, In Proc. 13th European Wireless Conference EW2 007, examines flexible radio resource reuse schemes for the downlink. The cell capacity under some presented reuse schemes is estimated and compared.
[0022] Texas Instruments: “ Inter - Cell Interference Mitigation for EUTRA”, 3GPP TSG RAN WGJ, R1-051059, 10-14 Oct. 2005, proposes frequency scheduling coordination for interference avoidance near the cell edge in an attempt to provide a service quality largely independent of UE (User Equipment) location. A soft reuse principle is applied for the allocation of frequency sub-bands in adjacent cells. This allocation is achieved through semi-static network coordination taking into account the traffic load, i.e. the distribution (location and/or transmit power requirements) and throughput requirements of UEs near the edge of each cell.
[0023] The 3GPP proposal concludes that a semi-static coordination of reserved frequency sub-bands among cells is preferable for LTE in order to more effectively address the varying throughput requirements and UE populations near the cell edge. Semi-static coordination may be achieved, for example, by the Node Bs communicating to the RNC their throughput requirements near the cell edge and with the RNC communicating to the Node Bs the partition of corresponding reserved frequency sub-bands. Combining frequency and time scheduling allows for even better flexibility in resource allocation and managing dynamic traffic loads near the cell edges thereby improving throughput performance. Similar to frequency coordination, time coordination can be static or semi-static with the latter allowing for more efficient resource allocation. FIG. 1 illustrates an example cell pattern for K=3 channel groups. Cell 1 is allocated a first reserved frequency sub-band, Cells 2 , 4 , and 6 are allocated a second reserved frequency sub-band, and Cells 3 , 5 , and 7 are allocated a third reserved frequency sub-band. Certain frequency sub-bands are reserved in each cell for use by UEs near the edge (UEs requiring high transmission power). UEs located toward the cell interior have available for scheduling the remaining frequency sub-bands and possibly some of the reserved sub-bands, if they were not allocated to UEs near the cell edge. The size of the reserved frequency sub-bands depends on the traffic load near the cell edge.
[0024] Texas Instruments: “ Performance of Inter - Cell Interference Mitigation with Semi - Static Frequency Planning for EUTRA Downlink”, 3GPP TSG RAN WG1, R1-051059, 13-17 Feb. 2006, considers performance of ICI mitigation based on the soft reuse principle for the allocation of reserved frequency sub-bands in adjacent cells in proposal R1-051059 above.
[0025] The inventor of the present invention finds that: Not at least during an early phase of newly commissioned networks, user distribution tends to be far from uniform both within cells and considering an area corresponding to plural cells. In order to facilitate establishment of new networks and also to run well-established networks efficiently, network equipment need allow efficient operations despite non-uniform user or traffic distributions. Cited prior art does not identify or benefit from the fact that users e.g. being further away from their serving base station may demonstrate a greater variance in experienced interference, e.g. downlink interference from surrounding base station serving user's of other cells as compared to users closer to their serving base stations.
SUMMARY
[0026] Embodiments of the present invention provide a method and apparatus of allocating channel resources in relation to a classification of users/user equipment devices or cells/cell sections in a communications system.
[0027] It is further an object of example embodiments of the invention to allocate channel resources to a class of users or user equipment devices, while the allocation not necessarily satisfies for all users or user equipment devices of that class a minimum requirement of communications on the channel resource.
[0028] It is also an object of embodiments of the invention to facilitate determining of and discriminating between merits of (candidate) allocations of channel resources.
[0029] Further it is an object of an embodiment of the invention to realize processing and equipment for determining a preferable allocation from one or more parameters reflecting user distribution or traffic load distribution.
[0030] Finally, it is an object of preferred embodiments of the invention to design a recursion that runs sufficiently fast to be capable of converging to an efficient allocation on a same or faster time-scale than for variations of user or traffic variations.
[0031] The embodied invention provides a method and equipment of channel resource allocation classifying one or more targets/target groups of the allocation (users, user equipment devices or communications), or corresponding cells/cell sections in an area of wireless service according to a representation of potential susceptibility to one or more disturbances (e.g. interference) and balancing the amount of channel resources allocated to the various classes versus experienced susceptibility according to a statistically based measure (e.g. expected value, or percentile) as described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 illustrates an example cell pattern for K=3 channel groups according to prior art.
[0033] FIG. 2 illustrates an example network topology in accordance with the invention.
[0034] FIG. 3 illustrates a frequency assignment of re-use 1, known as such in the art.
[0035] FIG. 4 shows an example static assignment where 1-reuse is applied for cell center users and 3-reuse is applied for cell edge users.
[0036] FIG. 5 schematically illustrates an example situation where a cell with high load at the cell edge (Cell A) gets a larger number of edge resources than a cell (Cell B) with low traffic load at the cell edge in accordance with embodiments of the invention.
[0037] FIG. 6 illustrates a snap-shot of allocation with adaptive partial reuse where edge resources are partially overlapping in different cells in accordance with embodiments of the invention.
[0038] FIG. 7 illustrates an example centric expansion of resource allocation illustrated in a single dimension (frequency) in accordance with an embodiment of the invention.
[0039] FIG. 8 illustrates in principle a flow chart of an evolutionary process in accordance with an embodiment of the invention.
[0040] FIG. 9 illustrates schematically an example crossover operation in accordance with an embodiment of the invention.
[0041] FIG. 10 illustrates some elements of a central frequency planner device in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0042] Every new generation of mobile networks aims at evolving the radio-access technology towards higher spectrum efficiency, higher data rates and lower latencies. In cellular wireless communications networks, one of the limiting factors towards this end is interference among cells utilizing a common spectrum. Universal reuse of radio spectrum, known as frequency reuse of factor 1 (1-reuse) gives rise to high inter-cell interference especially at the cell fringe. User Equipment devices located close to the cell edge are more susceptible to inter-cell interference. Due to their lower Signal to Interference and Noise Ratio (SINR), and as a consequence lower throughput, there have been many proposals suggesting fractional frequency reuse (FFR), also known as soft frequency reuse. As referred to in the background section, FFR divides users into cell-center users (CCUs), and cell-edge users (CEUs), based on their location or other information.
[0043] In this context it may be worth mentioning that the “edge region” of each cell may be defined geographically, at least to simplify understanding. Though, it may also be considered electrically, being defined by, e.g., signal strength or signal quality of received wireless signals, such as radio signals.
[0044] Anticipating cells with base stations in the center of each cell and CCUs and CEUs using the same reuse factor, it is observed that for a maximum downlink interference of CCUs, limited due to distance from (potentially) interfering transmitters/base stations, CEUs may be closer to the interfering transmitter and suffer from greater downlink interference. Preferably, channel resources applied for CEUs are made orthogonal/non-interfering for adjacent cells, thereby increasing the distance to interfering transmitters/base stations, while the channel resources applied for CCUs need not be made orthogonal/non-interfering as such. As in cited prior art, of course channel resources intended for CEUs but not needed by the CEUs in a particular traffic situation may be applied by CCUs.
[0045] There is a huge amount of prior art solutions for (static) allocation of channel resources to guarantee a certain minimum performance requirement in a worst case scenario.
[0046] However, in case of an (from a view-point of interference) advantageous user distribution, CEUs (anticipated to suffer the most in a worst case scenario) may actually experience a smaller interference than CCUs, despite allocated to as such non-orthogonal/interfering channel resources, this being due to a possible actual location further away from the interfering transmitter/base station. Consequently, it is possible to benefit from non-uniform user or traffic distribution by careful allocation of channel resources. This may be referred to as a statistical channel resource allocation. Preferably, such a careful allocation should be capable of adaptation to user or traffic distribution changes. Example embodiments in accordance with the invention demonstrate both such benefiting and adapting on a relevant time-scale.
[0047] FIG. 2 illustrates an example network topology in accordance with the invention. In the figure three cells are schematically illustrated, which of course is just an example number for the purpose of illustration. For each cell, two parts are considered—a center part and an edge part—preferably determined in relation to signal propagation properties. For each part users are for simplicity referred to as cell center users ( 201 ) and cell edge users ( 202 , 203 ). In an embodiment in accordance with the example network topology, adaptive partial frequency reuse is planned off-line by a central frequency planner ( 204 ) responsible for frequency assignment of a plurality of cells. In a preferred embodiment, such central frequency planner ( 204 ) is part of a communication system configuration management entity responsible for control and configuration of radio access and core networks of the wireless communications system. Performance measurements and user and traffic statistics, such as user distribution and load distribution, is collected ( 205 ) for the various cells for the central frequency planning providing a frequency reuse plan as output ( 206 ) from its central processing in corresponding central processing circuitry.
[0048] FIGS. 3-6 illustrate some example allocations for channel resources defined in tennis of frequency intervals. In FIG. 3 , a static assignment of frequencies (channel resources of the example) for 1-reuse is illustrated where all users in a cell share may be allocated any channel resource available to the system. In FIG. 4 , an example assignment where 1-reuse is applied for CCUs and 3-reuse is applied for CEUs is illustrated. In the static assignment no information on particular user distribution is applied and the channels in the 3-reuse part are split equally between the different channel groups for CEUs. In the example CEUs are allocated higher frequencies than CCUs. This is just for the purpose of illustration. CEUs could be allocated frequencies lower than the CCUs or be allocated channel resources with other interrelationships without departing from the scope of this invention. In FIG. 5 , a cell with high load at the cell edge (Cell A) gets a larger number of edge resources than a cell (Cell B) with low traffic load at the cell edge. Finally, in FIG. 6 an adaptive partial reuse is illustrated where edge resources are partially overlapping in different cells. Cells located in a position that from an interference perspective is favorable may be allocated such resource without severe negative on their impact or causing severe interference in other cells, thereby improving on cell throughput. When users are moving with their UE devices the channel resource allocation on individual bases need adapt accordingly. Also load statistics may vary over time, for which reason the number of channel resources assigned to the various cells/edge regions is preferably adapted thereto for preserved good or excellent performance balancing frequency reuse factor and perceived interference level. According to an example embodiment such frequency planning is achieved through an evolutionary method applying a genetic recursion as will be explained in detail below.
[0049] In FIGS. 3-6 some of the merits of the invention are explained using (for CCU5) 1- and (for CEUs) 3-reuse patterns as examples. The invention does not exclude that other numbers of channel groups are applied neither for CCUs nor for CEUs.
[0050] According to an embodiment, channel assignment of CEUs is arranged around a center frequency (or equivalently other resource) ( 702 ) and extending symmetrically around that center frequency within the allowable range ( 701 ) of the resource allowed for CEUs, as schematically illustrated in FIG. 7 . In case of an upper or lower limit of that range is exceeded, the extension is expanded cyclically ( 704 ), ( 705 ) to stay within the allowable range (and the resource ( 704 ) outside allowable range is not allocated). Considering a single range does not exclude that such range is chopped into smaller pieces while allocated considering the various pieces as part of a whole, the range limited by upper and lower limits of this whole. Due to such or equivalent elaborate allocation of the actual one or more resources, impact of interference may be kept smaller as compared to randomly allocating resources in the range of consideration.
[0051] FIG. 7 illustrates an example of such centric expansion illustrated in a single dimension (frequency). The example does not exclude that, for channel resources defined over more than one dimension, a corresponding approach is applied in more than one dimension (e.g. time or code).
[0052] According to the invention, and as illustrated in FIGS. 3-7 , some channel resources (frequency intervals) are kept static or semi-static applying a relatively small reuse factor (1 in the illustrated example), while other channel resources are assigned to their respective cells adaptively in accordance with load distribution. Consequently, out of a great number of channel resources, a subset thereof is considered for the adaptation. According to preferred embodiments of the invention, much of the processing is made centrally in what may be referred to as a Central Frequency Planner planning channel resource allocation for all cells or a subset thereof. The channel resources, in the sequel referred to as PRBs (Physical Resource Blocks) in accordance with terminology of, e.g., LTE technology, though without being limited thereto. Considering the frequency intervals/resources of the edge resources, they are preferably represented by a vector, s, comprising the number of PRBs of each cell edge region.
[0000] s=[x 1 , x 2 , . . . , x n ]. (eq. 1)
[0053] In the vector s, the number of elements, n, corresponds to the number of cells or cell edge regions of consideration.
[0054] Adaption of the vector, s, versus load distribution is made by means of an objective function, f(s). In accordance with embodiments of the invention, system throughput and system cell edge throughput are considered advantageous single objectives for such a function. For an objective function f S (s) reflecting System throughput in terms of sum of cell throughput of all cells of consideration of the network, and an objective function f CE (s) reflecting Cell Edge throughput in terms of the 5% point of a cumulative distribution function, CDF, of user throughput, an aggregated objective function reflecting cell throughput is achieved from a weighted sum of the System throughput and the Cell Edge throughput,
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[0055] With a multi-objective function, for which genetic methods are particularly useful, a plurality of objective criteria are considered, each corresponding to a performance objective. According to an embodiment of the invention, the objective functions are evaluated for a set of candidate frequency allocations and a weighted sum of the various objectives is applied as an aggregate objective function for evaluation. Generalizing equation (eq. 2), an aggregated objective function for evaluating a solution of , is
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[0056] Numerical optimization known in the art as such, e.g. steepest descent methods inclusive of stochastic versions such as expressed in a Least Mean Square algorithm may be applied for maximizing an objective function. According to a preferred embodiment of the invention, processing according to an evolutionary method is applied, which may be expressed in terms of a genetic process.
[0057] A candidate solution, also referred to as a chromosome using genetic terminology comprises a number of genes corresponding to decision variables. Using the notion of representation as above, the vector s is a chromosome and its elements are its genes x1, x2, . . . , xn. In a preferred representation, each gene corresponds to a number of allocated PRBs to cell edge section or corresponding section of a cell, or rather to users being classified as belonging to such a section. Consequently, there is a gene for each such section. Sections/edge bands of consideration, e.g. sections of a particular reuse factor, are included while the chromosome need not necessarily include all frequency bands or PRBs available to the system.
[0058] FIG. 8 illustrates in principle a flow chart of the evolutionary process in accordance with an embodiment of the invention. Inputs ( 801 ) to the genetic processing includes 15 population size, h, and parameters governing the generation of successor populations, such as fraction of a population to be replaced by a cross-over operation, and a mutation rate. An initial population is generated ( 802 ) comprising randomly generated decision variables, e.g. anticipating the various decision variables x being uniformly distributed within an allowable range [min(xi), max(xi)].
[0059] The generation of the initial population is then completed ( 802 ) by adding two solutions corresponding to static frequency allocation of relevant reuse factors, e.g. 1-reuse and 3-reuse (c.f. examples of FIGS. 3 and 4 ).
[0060] In an iterative process ( 803 )-( 807 ), a fitness value of each solution of a population, is determined ( 803 ) based on an objective function, such as the objective function in equation (eq. 2). A population of next iteration/generation is determined as follows: The h members of the population of the existing generation are ranked according to their fitness, such as according to fs(s), fCE(s) or a weighted sum thereof. The best performing (1−r) h members, where r is less than 1, of are maintained and r·h worst performing members are discarded and replaced by members resulting from a crossover ( 805 ) based on the maintained members, as explained further below in relation to FIG. 9 . A percentage of the thus generated h members of the next generation are mutated ( 806 ). Preferably the solutions to mutate are selected (pseudo-)randomly according to a uniform probability distribution. For each solution/member/chromosome to be mutated, preferably a single variable/gene is replace by a (pseudo-)randomly selected variable in the range relevance ([min(xi), max(xi)] for variable xi). A single digit mutation percentage is preferably selected. A simple stop condition ( 807 ) may be a threshold on maximum number of iterations or maximum time available to run the recursion, after which it ends possible to be started anew to find a next solution adapted to new conditions of operations, such as a new user or communications traffic distribution.
[0061] FIG. 9 illustrates schematically a crossover operation, where two children ( 903 ), ( 904 ) are generated from two parents (mother ( 901 ) and father ( 902 )). The first example child ( 903 ) is generated by having the first three variables from the mother ( 901 ) and the last n−3 variables from the father ( 902 ), while the second example child ( 904 ) has its first three elements from the father ( 902 ) and the last n−3 elements from the mother ( 901 ). Of course this example of illustration does not exclude that more or less genes/variables are inherited from each parent.
[0062] FIG. 10 illustrates some elements of a central frequency planner device in accordance with an embodiment of the invention. The device ( 1001 ) is preferably collocated or connected to an OAM (Operations, Administration, and Maintenance) center of a wireless communications system. The device comprises processing circuitry ( 1002 ) adapted according to channel allocation as described above, including e.g. allocation based on collected statistics, and interface communication circuitry ( 1003 ) for communicating with various base stations including e.g. collecting statistics on user equipment location and performance and communicating frequency reuse-factors and channel resources such as physical resource blocks available in various cells or cell sections. Preferably, the device also comprises storage means ( 1004 ) of storing collected statistical data.
[0063] In this description, certain acronyms and concepts widely adopted within the technical field have been applied in order to facilitate understanding. The invention is not limited to units or devices due to being provided particular names or labels. It applies to all methods and devices operating correspondingly. This also holds in relation to the various systems that the acronyms might be associated with.
[0064] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of combining the various embodiments, or features thereof, as well as of further modifications. This specification is intended to cover any variations, uses, adaptations or implementations of the invention; not excluding software enabled units and devices, processing in different sequential order where non-critical, or mutually non-exclusive combinations of features or embodiments; within the scope of subsequent claims following, in general, the principles of the invention as would be obvious to a person skilled in the art to which the invention pertains.
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Channel resource allocation is disclosed. Embodiments of channel resource allocation allocate channel resources to plural cells or cell sections according to a classification depending on distribution statistics.
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This is a divisional of application Ser. No. 10/629,796, filed Jul. 30, 2003, now U.S. Pat. No. 7,198,773, issued Apr. 3, 2007, and claims the benefit of Korean Patent Application No. 2003-0049836, filed Jul. 21, 2003, all of which are incorporated herein by reference.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a method of fabricating ZnO nanostructures and its apparatus, and more particularly, to a method of fabricating ZnO nanostructures from Zn gas, which is produced by a reduction process between ZnO powder and graphite, on a silicon substrate, wherein various types of nanostructures are reproducibly generated by adjusting the processing temperature and the mixed ratio between oxygen and argon gases, which are introduced into the interior of a reaction tube as carrier gases, and its apparatus.
2. Description of the Background Art
Nanostructures are generally in the range of from a few nanometers to a few hundred nanometers and exhibit novel physical and chemical properties due to their nanoscaled dimensions unlike bulk type materials. These nanoscaled building blocks can be used in fabricating highly sophisticated and/or functional nanodevices in the fields of electronics, optoelectronics, and electrochemistry. To date, nanoscaled building blocks such as quantum dots, nanopowders, nanowires, nanotubes, quantum wells, nanofilms, and nano composites have been intensively investigated, especially for the bottom-up approaches to nanoelectronics (Y. Xia at al, Advanced Materials , Vol. 15, p. 353 (2003); G. Tseng, Science , Vol. 294, p. 1293 (2001)).
In the meantime, ZnO has been in the spotlight as a promising material for electronic devices, surface acoustic wave devices, optoelectronic devices, piezoelectric devices, and chemical sensors, transparent electrodes due to its wide bandgap, optical transparency, and tunable conductivity.
Furthermore, advances in epitaxial growth technology have promoted the developments of various optoelectronic devices including blue/green light emitting diode and laser diode.
A typical example of ZnO nanostructure fabrication is synthesis of nanowires (Y. Xia at al, Advanced Materials , Vol. 15, p. 353 (2003); M. H. Huang et al., Advanced Materials , Vol. 13, p. 113 (2001)).
Various types of 1-dimensional ZnO nanostructures (nanowires, nanotubes, etc.) have been fabricated using such processes as carbothermal reduction and chemical vapor deposition, and they were also shown to be applicable into optoelectronic devices, laser diodes, chemical sensors and the like.
Although there are a number of reports on the ZnO nanostructures, the feasibility of realizing highly integrated functional devices is still questionable due to the difficulties in alignment and assembly of the nanostructures. In this regards, creation of nanoscaled building blocks of various size and shapes is crucial. In this invention, we invented various ZnO nanostructures, especially ultrawide ZnO nanosheets and nanowire arrays which can be easily manipulated by conventional lithography and/or assembly techniques, while maintaining nano-sized features.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a reproducible and cost-effective method for fabricating nanostructures of various shapes and large size, and its apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned aspects and other features of the present invention will be explained in the following description, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a schematic cross-sectional view of a nanostructure apparatus,
FIG. 2 shows an enlarged perspective view the source materials and substrates,
FIG. 3 shows the summary of various types of nanostructures produced in the area where the internal temperature of a reaction tube and the mixing ratio of carrier gases are under control,
FIG. 4 shows the electron microscopic view of various types of nanostructures produced in the area where the internal temperature of a reaction tube and the mixing ratio of carrier gases are under control (1: nanowires, 2: nanowire arrays, 3: nanosheets, 4: nanorods, 5: nanoplates), and
FIG. 5 shows the electron microscopic view of the nanosheets and nanowire arrays typically observed according to the variation in the mixing ratio of carrier gases (a: nanosheets, b: nanowire arrays).
CODE EXPLANATION
10: Heating Element
20: Reaction Tube
21: Carrier Gas Inlet
22: Carrier Gas Outlet
30: Reactant
31: Boat
32: Source material
33: Substrate
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method for fabricating ZnO nanostructures of various types from Zn gas, which is produced by a reduction process between ZnO powder and graphite, on a silicon substrate; wherein the reduction process is performed at 800-950° C. in the presence of a gas mixture where oxygen content is 1-20 vol % with reference to that of argon gas.
The present invention also relates to an apparatus for fabricating ZnO nanostructures comprising:
a heating element 10 which maintains the internal temperature of a reaction tube at 800-950° C. for heating a substrate and source materials within the reaction tube;
a reaction tube 20 for distribution of source material and a substrate which horizontally passes through the interior of the heating element 10 while being positioned inside the heating element 10 , wherein a gas inlet 21 and a gas outlet 22 for the introduction and release of a carrier gas, respectively, are located at each end of the reaction tube; and
a reactant 30 which, being positioned inside the reaction tube 20 , receives the source materials and the substrate.
The present invention is explained in more detail as set forth hereunder.
The preparation of source materials and a catalyzed substrate are as follows. A 1:1 mixture of ZnO and graphite by weight is dry-milled for 1-3 hours. The ZnO powder and graphite used in the present invention should have high purity (>99%) and a particle of greater than 100 mesh in size, preferably 100-325 mesh. These two source materials are inexpensive and are readily available in commercial market.
Graphite is added to facilitate the fabrication at a temperature lower than 1000° C. Graphite reacts with ZnO at low-temperature range (800˜950° C.) to form Zn gas, which is then used in fabricating ZnO nanostructures. The substrate, on which nanostructures are fabricated, is silicon (100) substrate and it is coated with gold (Au) to be 10-30 angstrom (Å) thick. According to a recent publication (M. H. Huang et al., Advanced Materials , Vol. 13, p. 113. (2001)), coated Au reacts with Zn gas which results from the carbothermal reduction of ZnO with graphite, thereby producing an Au—Zn alloy and finally ZnO nanowire.
The well-known technology disclosed in the aforementioned Huang et al. teaches to use only argon (Ar) gas as a carrier gas and thus it cannot fabricate other types of nanostructures but only ZnO nanowires. However, the oxygen gas, where the oxygen gas is used 1-20 vol % with reference to that of an argon gas, thus rendering a great advantage over the conventional technology.
FIG. 1 shows a schematic cross-sectional view of a nanostructure apparatus, which comprises a heating element 10 for controlling the internal temperature of a heating reaction tube 20 , a heating reaction tube 20 for entry and release of carrier gases, and a reactant 30 which receives source materials and a substrate. The heating element 10 controls the internal temperature of the heating reaction tube 20 to be maintained at a temperature of 800˜950° C. The heating reaction tube 20 , while being positioned inside the heating element 1 , horizontally passes through the interior of the heating element 10 , wherein a gas inlet 21 and a gas outlet 22 for the entry and release of a carrier gas, respectively, are located at each end of the reaction tube 20 ; and a reactant 30 which, being positioned inside the reaction tube 20 , receives the source materials and the substrate. The reaction tube 20 is made of transparent quartz tube.
The reactant 30 is provided with source materials and a substrate. As shown in FIG. 2 , the reactant 30 , while its upper portion is laid open, comprises a boat 31 of a rectangular shape where a certain amount of source materials and a substrate are to be contained; source materials and a substrate 32 which are to be contained in the boat 31 ; and a plurality of substrates 33 which are spanned at regular intervals over the boat 31 in the direction of the width of the boat 31 . The boat 31 is made of alumina (Al 2 O 3 ) and has a size of 13 mm×13 mm×60 mm. The source materials is a mixed composition where ZnO powder and graphite are mixed in 1:1 ratio by weight and is filled in to be 30-70% of the total capacity of the boat 31 . The substrate 33 is a silicon plate coated with gold (Au) and placed on the top of the boat 31 after they are cut into a size of 8 mm×2 mm. In this array, it is very important that the location of a substrate be separated from the source materials to the extent of 3-10 mm in a vertical direction so that an appropriate level of Zn vapor pressure can be maintained and this, along with supplied oxygen gas, then enables to finally obtain nanostructures. The substrate and source materials are positioned at the same location because the temperature of the substrate is desired to be the same as that of the source materials. In particular, they are placed about 0-50 mm apart from the center of the reaction tube toward the outlet of the carrier gas.
The method of fabricating nanostructures using a nanostructure apparatus is described further herein under.
Prior to heat treatment, the reaction tube provided with the substrate and source materials as shown in FIG. 2 was purged with Ar and O 2 gases for an hour. By this process, residual air in the tube was evacuated.
The appropriate amount of Ar flow for the evolution of ZnO nanostructures was in the range of 20˜50 cc/min and O 2 flow was mixed with Ar gas to be 1-20% percent with reference to that of Ar gas. The variation within the range of 20˜50 cc/min did not reveal any noticeable changes in the resulting nanostructures. Hereinafter, all the experimental details are described based on the condition of Ar 30 cc. After heat-treatment, various nanostructures such as combs, rods, rod arrays, ultrawide sheets in addition to the typical nanowires were fabricated.
In one embodiment of the present invention, nanostructures were fabricated by fixing the amount of Ar flow at 30 cc/min while allowing variations in the reaction temperature and the mixing ratio of oxygen gas. The result showed that the conventional types of ZnO nanowires were well fabricated but also various structures such as ZnO nanowire arrays, nanosheets, nanorods, and nanoplates were formed as well according to the control of reaction temperature and the mixing ratio of oxygen gas.
FIG. 3 shows representative nanostructures formed according to the variation of the reaction temperature and the mixing ratio of oxygen gas and FIG. 4 shows an electron microscopic view of each of the images of nanostructures thus formed. FIG. 3 shows most frequently observed structures and these representative structures continue to appear in the neighboring experimental conditions where the fabrication temperature and the mixing ratio of oxygen gas are slightly varied.
In an embodiment, where the Ar flow is 30 cc/min, reaction temperature is 800-850° C., and the oxygen content with reference to the Ar gas is 1-20 vol %, nanowire structures were fabricated and the electron microscopic view of the fabricated nanowires are shown in FIG. 4 ( 1 ). The nanowires were 50-200 nm in diameter and 5-100 μm in length.
In another embodiment, where the Ar flow is 30 cc/min, reaction temperature is 850-900° C., and the oxygen content with reference to the Ar gas is 1-2 vol %, nanowire arrays were fabricated and the electron microscopic view of the fabricated nanowire arrays are shown in FIG. 4 ( 2 ). The nanowire arrays were of a comb shape and were 10-50 μm in width, 50-1000 μm in length and 50-300 nm in diameter. These nanostructures were reproducibly fabricated in the above experimental condition. These nanostructures can be applied to arrayed nanolaser array and the like and also can be used as a chemical or physical sensor arrays.
In still another embodiment, where the Ar flow is 30 cc/min, reaction temperature is 850-900° C., and the oxygen content with reference to the Ar gas is 2-20 vol %, nanosheets were fabricated and the electron microscopic view of the fabricated nanosheets are shown in FIG. 4 ( 3 ). The nanosheets were 10-100 μm in width, 500-2000 μm in length and 50-150 nm in diameter. These nanostructures were reproducibly fabricated in the above experimental condition. These nanostructures can be applied to highly functional and high density chemical sensors, electrodes, catalysts and the like.
In still another embodiment, where the Ar flow is 30 cc/min, reaction temperature is 900-950° C., and the oxygen content with reference to the Ar gas is 1-8 vol %, nanorods were fabricated and the electron microscopic view of the fabricated nanorods are shown, in FIG. 4 ( 4 ). The nanorods were 5-50 μm in length and 200-500 nm in diameter. These nanorods were reproducibly fabricated in the above experimental condition. These nanostructures can be applied to laser arrays and the like.
In still another embodiment, where the Ar flow is 30 cc/min, reaction temperature is 900-950° C., and the oxygen content with reference to the Ar gas is 8-20 vol %, nanoplates were fabricated and the electron microscopic view of the fabricated nanoplates are shown in FIG. 4 ( 5 ). The nanoplates were 5-50 μm in width, 20-1000 μm in length and 500-2000 nm in diameter. These nanoplates were reproducibly fabricated in the above experimental condition. These nanostructures can be applied to chemical catalysts and the like.
In still another embodiment, where the Ar flow is 30 cc/min, reaction is performed for 30 min at 900° C., and the oxygen content with reference to the Ar gas is 10 and 2 vol %, respectively, nanosheets and nanowire arrays were fabricated, respectively, and their electron microscopic views of the fabricated nanosheets and nanowire arrays are shown in FIGS. 5( a ) and 5 ( b ), respectively.
When the oxygen content was 10 vol %, nanosheets were fabricated and they were 70 μm in width, 500 μm in length and 100 nm in diameter. When the oxygen content was 2 vol %, nanowire arrays were fabricated and they were 30-50 μm in width, 100-200 μm in length and 100 nm in diameter. The electron microscopic view of the fabricated nanosheets are shown in FIG. 5( a ) and the electron microscopic view of the fabricated nanowire arrays are shown in FIG. 5( b ).
Among the aforementioned various nanostructures, nanosheets and nanowire arrays are of utmost importance in technological aspects. For example, the nanosheets have high specific surface area and chemical stability, and thus they are useful in applications to energy generation, storage, and the like. Further, the comb-like structures of nanowire arrays may be used as aligned nanoscale building blocks such as arrayed laser assembly and arrayed chemical sensor block.
As described above, the nanostructures obtained in the present invention, unlike the known nanostructures, are peculiar in that they have an ultrawide structure of having few tens to few hundred nanometers in thickness while their width and length are of few tens of micrometers, respectively. Therefore, these nanostructures are advantageous in that they can facilitate the fabrication of nanoelectronic devices using an optical microscope or a simple process without going through a rather complex process such as e-beam lithography.
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An apparatus for fabricating ZnO nanostructures includes a heating element, a horizontal reaction tube having an inlet and an outlet. The reaction tube is positioned inside the interior cavity of the heating element with the inlet disposed to introduce a carrier gas into the reaction tube. The apparatus includes a source of a carrier gas in flow communication with the inlet, a container within the reaction tube that is disposed to receive and contain source materials comprising ZnO and graphite. An array of solid substrates is located on the container above the source materials. Adjacent substrates in the array are positioned with a space in between to allow the carrier gas to impinge on the source materials in the container.
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FIELD OF THE INVENTION
The present invention relates to cure accelerators for epoxy resin compositions, to epoxy resin compositions comprising these cure accelerators, to processes utilizing these cure accelerators and to articles made therefrom. Specifically, the invention relates to utilizing an alkali metal containing compound as a cure accelerator and more specifically to an accelerated resin varnish including same. The alkali metal containing cure accelerators are preferably alkali metal hydroxides, alkoxides, carboxylates or alkali metal halide salts. Articles prepared from the resin compositions of the invention exhibit enhanced thermal properties when compared to articles prepared from comparable compositions which include other accelerators, such as for example, imidazoles. In addition, articles prepared from the resin compositions of the invention exhibit similar non-thermal properties when compared to articles prepared from such comparable compositions. The resin compositions of the invention may be used for any purpose, but are particularly suited to be utilized in the manufacture of laminates for printed circuit boards and non-electrical structural applications.
BACKGROUND OF THE INVENTION
Articles prepared from resin compositions which have improved resistance to elevated temperatures are desirable for many applications. In particular these articles, having improved elevated temperature resistance, are desirable for printed circuit board applications due to industry trends which include higher circuit densities, increased board thickness, lead free solders, and higher temperature use environments.
Articles such as laminates, and particularly structural and electrical copper clad laminates, are generally manufactured by pressing, under elevated temperatures and pressures, various layers of partially cured prepregs and optionally copper sheeting. Prepregs are generally manufactured by impregnating a thermosettable epoxy resin composition into a porous substrate, such as a glass fiber mat, followed by processing at elevated temperatures to promote a partial cure of the epoxy resin in the mat to a “B-stage.” Complete cure of the epoxy resin impregnated in the glass fiber mat typically occurs during the lamination step when the prepreg layers are pressed under high pressure and elevated temperatures for a time sufficient to allow for complete cure of the resin.
Epoxy resin compositions which impart enhanced thermal properties are desirable in the manufacture of prepregs and laminates. Such systems offer improved heat resistance and reduced thermal expansion required for complex printed circuit board circuitry and for higher fabrication and usage temperatures. However, such resin compositions are typically more expensive to formulate and may suffer from inferior performance capabilities.
U.S. Pat. Nos. 6,451,878 and 5,081,206, for example, disclose the use of several advancement or upstaging catalysts, including alkali metal hydroxides, for the reaction between an epoxy group and a phenolic hydroxyl group for the preparation of higher molecular weight epoxides.
U.S. Pat. No. 5,380,804 discloses curable compositions which employ 1,3,5-tris-(2-carboxyethyl)isocyanurate crosslinker and an optional cure catalyst which may include phosphines, phosphates, amines, oxides, alkoxides, such as methoxide or ethoxide, hydroxides, such as sodium hydroxide or potassium hydroxide, carbonates, carboxylic salts, quaternary salts and the like.
U.S. Pat. No. 4,251,594 discloses an improvement for the preparation of electrical laminates in utilizing an alkali metal hydroxide as a catalyst for epoxy-phenolic hydroxyl fusion reaction.
U.S. Pat. No. 2,589,245 discloses complex amide-epoxide compositions and that alkaline and Friedel-Crafts type catalysts, including sodium hydroxide, potassium hydroxide and sodium phenoxide, are active in promoting the reaction of epoxide groups with amines.
However, the prior art does not teach or suggest the use of alkali metal containing compounds as an accelerator which may be used with curing agents for the cure of epoxy compounds to produce laminates, for printed circuit boards and non-electrical structural applications, having enhanced thermal properties.
In light of the above, there is a need in the art for epoxy resin compositions for preparing articles having improved thermal properties and for processes to produce them. There is also a need in the art for inexpensive resin compositions for achieving enhanced thermal properties and for articles, especially prepregs, having enhanced thermal properties.
SUMMARY OF THE INVENTION
In one embodiment, the invention provides for a process for preparing a resin coated article. The process steps include contacting a substrate with an accelerated resin composition which includes an epoxy resin, a curing agent, and an alkali metal containing cure accelerator compound. In another embodiment, the invention provides for articles, especially prepregs, prepared by the process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The epoxy resin composition of the present invention includes at least one epoxy resin component, at least one curing agent, at least one alkali metal containing accelerator, and optionally one or more solvents.
A. Epoxy Resin Component
The epoxy resin compositions of the invention include at least one epoxy resin component. Epoxy resins are those compounds containing at least one vicinal epoxy group. The epoxy resin may be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic and may be substituted. The epoxy resin may also be monomeric or polymeric.
The epoxy resin compound utilized may be, for example, an epoxy resin or a combination of epoxy resins prepared from an epihalohydrin and a phenol or a phenol type compound, prepared from an epihalohydrin and an amine, prepared from an epihalohydrin and a carboxylic acid, or prepared from the oxidation of unsaturated compounds.
In one embodiment, the epoxy resins utilized in the compositions of the present invention include those resins produced from an epihalohydrin and a phenol or a phenol type compound. The phenol type compound includes compounds having an average of more than one aromatic hydroxyl group per molecule. Examples of phenol type compounds include dihydroxy phenols, biphenols, bisphenols, halogenated biphenols, halogenated bisphenols, hydrogenated bisphenols, alkylated biphenols, alkylated bisphenols, trisphenols, phenol-aldehyde resins, novolac resins (i.e. the reaction product of phenols and simple aldehydes, preferably formaldehyde), halogenated phenol-aldehyde novolac resins, substituted phenol-aldehyde novolac resins, phenol-hydrocarbon resins, substituted phenol-hydrocarbon resins, phenol-hydroxybenzaldehyde resins, alkylated phenol-hydroxybenzaldehyde resins, hydrocarbon-phenol resins, hydrocarbon-halogenated phenol resins, hydrocarbon-alkylated phenol resins, or combinations thereof.
In another embodiment, the epoxy resins utilized in the compositions of the invention preferably include those resins produced from an epihalohydrin and bisphenols, halogenated bisphenols, hydrogenated bisphenols, novolac resins, and polyalkylene glycols, or combinations thereof.
In another embodiment, the epoxy resin compounds utilized in the compositions of the invention preferably include those resins produced from an epihalohydrin and resorcinol, catechol, hydroquinone, biphenol, bisphenol A, bisphenol AP (1,1-bis(4-hydroxyphenyl)-1-phenyl ethane), bisphenol F, bisphenol K, tetrabromobisphenol A, phenol-formaldehyde novolac resins, alkyl substituted phenol-formaldehyde resins, phenol-hydroxybenzaldehyde resins, cresol-hydroxybenzaldehyde resins, dicyclopentadiene-phenol resins, dicyclopentadiene-substituted phenol resins, tetramethylbiphenol, tetramethyl-tetrabromobiphenol, tetramethyltribromobiphenol, tetrachlorobisphenol A, or combinations thereof.
The preparation of such compounds is well known in the art. See Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 9, pp 267-289. Examples of epoxy resins and their precursors suitable for use in the compositions of the invention are also described, for example, in U.S. Pat. Nos. 5,137,990 and 6,451,898 which are incorporated herein by reference.
In another embodiment, the epoxy resins utilized in the compositions of the present invention include those resins produced from an epihalohydrin and an amine. Suitable amines include diaminodiphenylmethane, aminophenol, xylene diamine, anilines, and the like, or combinations thereof.
In another embodiment, the epoxy resins utilized in the compositions of the present invention include those resins produced from an epihalohydrin and a carboxylic acid. Suitable carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrahydro- and/or hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, isophthalic acid, methylhexahydrophthalic acid, and the like or combinations thereof.
In another embodiment, the epoxy resin compounds utilized in the compositions of the invention include those resins produced from an epihalohydrin and compounds having at least one aliphatic hydroxyl group. In this embodiment, it is understood that such resin compositions produced contain an average of more than one aliphatic hydroxyl groups. Examples of compounds having at least one aliphatic hydroxyl group per molecule include aliphatic alcohols, aliphatic diols, polyether diols, polyether triols, polyether tetrols, any combination thereof and the like. Also suitable are the alkylene oxide adducts of compounds containing at least one aromatic hydroxyl group. In this embodiment, it is understood that such resin compositions produced contain an average of more than one aromatic hydroxyl groups. Examples of oxide adducts of compounds containing at least one aromatic hydroxyl group per molecule include ethylene oxide, propylene oxide, or butylene oxide adducts of dihydroxy phenols, biphenols, bisphenols, halogenated bisphenols, alkylated bisphenols, trisphenols, phenol-aldehyde novolac resins, halogenated phenol-aldehyde novolac resins, alkylated phenol-aldehyde novolac resins, hydrocarbon-phenol resins, hydrocarbon-halogenated phenol resins, or hydrocarbon-alkylated phenol resins, or combinations thereof.
In another embodiment the epoxy resin refers to an advanced epoxy resin which is the reaction product of one or more epoxy resins components, as described above, with one or more phenol type compounds and/or one or more compounds having an average of more than one aliphatic hydroxyl group per molecule as described above. Alternatively, the epoxy resin may be reacted with a carboxyl substituted hydrocarbon, which is described herein as a compound having a hydrocarbon backbone, preferably a C 1 -C 40 hydrocarbon backbone, and one or more carboxyl moieties, preferably more than one, and most preferably two. The C 1 -C 40 hydrocarbon backbone may be a straight- or branched-chain alkane or alkene, optionally containing oxygen. Fatty acids and fatty acid dimers are among the useful carboxylic acid substituted hydrocarbons. Included in the fatty acids are caproic acid, caprylic acid, capric acid, octanoic acid, VERSATIC™ acids, available from Resolution Performance Products LLC, Houston, Tex., decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, pentadecanoic acid, margaric acid, arachidic acid, and dimers thereof.
In another embodiment, the epoxy resin is the reaction product of a polyepoxide and a compound containing more than one isocyanate moiety or a polyisocyanate. Preferably the epoxy resin produced in such a reaction is an epoxy-terminated polyoxazolidone.
B. Curing Agents
In one embodiment, the curing agents utilized in the compositions of the invention include amine- and amide-containing curing agents having, on average, more than one active hydrogen atom, wherein the active hydrogen atoms may be bonded to the same nitrogen atom or to different nitrogen atoms. Examples of suitable curing agents include those compounds that contain a primary amine moiety, and compounds that contain two or more primary or secondary amine or amide moieties linked to a common central organic moiety. Examples of suitable amine-containing curing agents include ethylene diamine, diethylene triamine, polyoxypropylene diamine, triethylene tetramine, dicyandiamide, melamine, cyclohexylamine, benzylamine, diethylaniline, methylenedianiline, m-phenylenediamine, diaminodiphenylsulfone, 2,4 bis(p-aminobenzyl)aniline, piperidine, N,N-diethyl-1,3-propane diamine, and the like, and soluble adducts of amines and polyepoxides and their salts, such as described in U.S. Pat. Nos. 2,651,589 and 2,640,037.
In another embodiment, polyamidoamines may be utilized as a curing agent in the resin compositions of the invention. Polyamidoamines are typically the reaction product of a polyacid and an amine. Examples of polyacids used in making these polyamidoamines include 1,10-decanedioic acid, 1,12-dodecanedioic acid, 1,20-eicosanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid and dimerized and trimerized fatty acids. Amines used in making the polyamidoamines include aliphatic and cycloaliphatic polyamines such as ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, 1,4-diaminobutane, 1,3-diaminobutane, hexamethylene diamine, 3-(N-isopropylamino)propylamine and the like. In another embodiment, polyamides are those derived from the aliphatic polyamines containing no more than 12 carbon atoms and polymeric fatty acids obtained by dimerizing and/or trimerizing ethylenically unsaturated fatty acids containing up to 25 carbon atoms.
In another embodiment, the curing agents are aliphatic polyamines, polyglycoldiamines, polyoxypropylene diamines, polyoxypropylenetriamines, amidoamines, imidazoles, reactive polyamides, ketimines, araliphatic polyamines (i.e. xylylenediamine), cycloaliphatic amines (i.e. isophoronediamine or diaminocyclohexane), menthane diamine, 4,4-diamino-3,3-dimethyldicyclohexylmethane, heterocyclic amines (aminoethyl piperazine), aromatic polyamines (methylene dianiline), diamino diphenyl sulfone, mannich base, phenalkamine, N,N′,N″-tris(6-aminohexyl) melamine, and the like. In another embodiment, imidazoles, which may be utilized as an accelerator for a curing agent, may also be utilized as a curing agent.
In another embodiment, the curing agent is a phenolic curing agent which includes compounds having an average of one or more phenolic groups per molecule. Suitable phenol curing agents include dihydroxy phenols, biphenols, bisphenols, halogenated biphenols, halogenated bisphenols, hydrogenated bisphenols, alkylated biphenols, alkylated bisphenols, trisphenols, phenol-aldehyde resins, phenol-aldehyde novolac resins, halogenated phenol-aldehyde novolac resins, substituted phenol-aldehyde novolac resins, phenol-hydrocarbon resins, substituted phenol-hydrocarbon resins, phenol-hydroxybenzaldehyde resins, alkylated phenol-hydroxybenzaldehyde resins, hydrocarbon-phenol resins, hydrocarbon-halogenated phenol resins, hydrocarbon-alkylated phenol resins, or combinations thereof. Preferably, the phenolic curing agent includes substituted or unsubstituted phenols, biphenols, bisphenols, novolacs or combinations thereof.
In another embodiment, the curing agent is a polybasic acid or its corresponding anhydride. Examples of polybasic acids include di-, tri-, and higher carboxylic acids, such as, oxalic acid, phthalic acid, terephthalic acid, succinic acid, alkyl and alkenyl-substituted succinic acids and tartaric acid. Examples also include polymerized unsaturated acids, for example, those containing at least 10 carbon atoms, and preferably more than 14 carbon atoms, such as, dodecenedioic acid, and 10,12-eicosadienedioic acid. Examples of suitable anhydrides include phthalic anhydride, succinic anhydride, maleic anhydride, nadic anhydride, nadic methyl anhydride, pyromellitic anhydride, trimellitic anhydride and the like. Other types of acids that are useful are those containing sulfur, nitrogen, phosphorus or halogens; chlorendic acid, benzene phosphonic acid, and sulfonyl dipropionic acid bis(4-carboxyphenyl)amide.
The ratio of curing agent to epoxy resin is preferably suitable to provide a fully cured resin. The amount of curing agent which may be present may vary depending upon the particular curing agent used (due to the cure chemistry and curing agent equivalent weight) as is known in the art.
C. Alkali Metal Containing Accelerator Compounds
The accelerators of the invention include those alkali metal containing compounds which catalyze the reaction of the epoxy resin with the curing agent. The alkali metal compound of the invention acts with curing agent to form an infusible reaction product between the curing agent and the epoxy resin in a final article of manufacture such as a structural composite or laminate. By an infusible reaction product, it is meant that the epoxy resin has essentially completely cured, which for example may be at a time when there is little or no change between two consecutive T g measurements (ΔT g ).
In one embodiment, the alkali metal containing compound is an alkali metal hydroxide or alkoxide. In another embodiment, the alkali metal containing compound is represented by the formulae:
MO—R Formula 1a
or
(MO) n —R Formula 1b
In each of Formula 1a and 1b, M is a metal selected from Group 1 of the Periodic Table of the Elements. In another embodiment, M is lithium, sodium or potassium. In another embodiment M is sodium or potassium. In another embodiment M is potassium. O is oxygen. R is hydrogen or a substituted or unsubstituted hydrocarbyl group. n is an integer, preferably n is 1 to 50 or 1 to 20.
The term “hydrocarbyl” encompasses all groups containing only carbon and hydrogen atoms including alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl and alkylaryl groups. Preferred hydrocarbyl groups comprise 1 to 40, 1 to 20, 1 to 12 or 1 to 6 carbon atoms. Substituted means that at least one hydrogen atom on a group is replaced with a hydrocarbyl, halide, halocarbyl, alkylamido, alkoxy, siloxy, aryloxy, alkylthio, arylthio, dialkylamino, dialkylphosphino, or other substituents.
The term “alkyl”, means a straight-chain, branched-chain or cyclic alkyl group. Examples of such groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl, 2-ethylhexyl, octyl, cyclopentyl, cyclohexyl and the like. The cyclic alkyl groups may be substituted with one or more straight-chain and/or branched-chain alkyl groups (i.e., may be alkylcycloalkyl groups such as, e.g., methylcyclohexyl etc.). Conversely, the straight-chain and branched-chain alkyl groups may be substituted with one or more cyclic alkyl groups (i.e., may be cycloalkylalkyl groups such as cyclohexylmethyl etc.). Moreover, unless indicated otherwise, the above alkyl groups may be substituted by one or more groups independently selected from halogen (e.g., F, Cl, Br), alkoxy (e.g., methoxy, ethoxy, propoxy, butoxy and the like), hydroxy, amino, monoalkylamino (e.g., methylamino, ethylamino, propylamino and the like) and dialkylamino (e.g., dimethylamino, diethylamino, dipropylamino, diisopropylamino, piperidino and the like) and trihydrocarbylsilyl (e.g., trimethylsilyl, triphenylsilyl and the like). Unless otherwise stated, the above definition of the term “alkyl” also applies to groups comprising one or more alkyl groups.
The term “alkenyl” means “alkyl” as defined above having one or more double bonds, and the term “alkynyl” means “alkyl” as defined above having one or more triple bonds. Examples of alkenyl groups include, but are not limited to, ethenyl, propenyl, allyl, butenyl, 1,4-butadienyl, isopropenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl and the like.
The term “aryl” means an aromatic group, which optionally may contain one or more heteroatoms (preferably selected from N, O and S and combinations thereof) in the ring. Illustrative, non-limiting examples of aryl groups are phenyl, naphthyl, fluorenyl, chlorophenyl, dichlorophenyl, fluorophenyl, perfluorophenyl, hydroxyphenyl, anisyl, biphenyl, nitrophenyl, acetylphenyl, aminophenyl, pyridyl, pyridazyl, quinolyl, and the like. Unless otherwise stated, the above definition of the term “aryl” also applies to groups which comprise one or more aryl groups. For example, the term “aryloxy” means an aryl ether group wherein the term “aryl” is as defined above.
The term “alkoxy” means an alkyl or alkenyl ether group wherein the terms “alkyl” and “alkenyl” are as defined above. Examples of suitable alkyl ether groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy, phenoxy, allyloxy, trifluoromethoxy and the like.
The term “halogen” means fluorine, chlorine, bromine and iodine.
In one embodiment, referring to Formula 1a or 1b, M is lithium, sodium or potassium, or M is sodium or potassium, and R is hydrogen or an alkyl group, preferably a C 1 to C 40 alkyl group, a C 1 to C 20 alkyl group, or a C 1 to C 6 alkyl group. In another embodiment M is sodium or potassium and the group OR represents a methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy, or phenoxy group. In another embodiment, the alkali metal containing accelerator compound is sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium methoxide, potassium methoxide, lithium methoxide, or combinations thereof.
In one embodiment Formula 1a or 1b refers to an alkali metal phenoxide formed from a phenolic or a polyphenolic compound. Examples of phenolic compounds and polyphenolic compounds include phenols, dihydroxy phenols, biphenols, bisphenols, halogenated biphenols, halogenated bisphenols, hydrogenated bisphenols, alkylated biphenols, alkylated bisphenols, trisphenols, phenol-aldehyde resins, novolac resins (i.e. the reaction product of phenols and simple aldehydes, preferably formaldehyde), halogenated phenol-aldehyde novolac resins, substituted phenol-aldehyde novolac resins, phenol-hydrocarbon resins, substituted phenol-hydrocarbon resins, phenol-hydroxybenzaldehyde resins, alkylated phenol-hydroxybenzaldehyde resins, hydrocarbon-phenol resins, hydrocarbon-halogenated phenol resins, hydrocarbon-alkylated phenol resins, or combinations thereof.
In one embodiment, the alkali metal containing compound is an alkali metal carboxylate. In another embodiment, the alkali metal containing compound is represented by the formulae:
MOOC—R Formula 2a
or
(MOOC) n —R Formula 2b
In each of Formula 2a and 2b, O is oxygen, C is carbon and M, R and n are defined as above.
In one embodiment, referring to Formula 2a or 2b, M is sodium or potassium and R is an alkyl group, preferably a C 1 to C 40 alkyl group, a C 1 to C 20 alkyl group or a C 1 to C 6 alkyl group.
In another embodiment, the alkali metal containing carboxylate is a saturated, unsaturated, aliphatic, aromatic or saturated cyclic carboxylic acid salt where the carboxylate group has preferably from 2 to 24 carbon atoms, such as for example acetate, propionate, butyrate, valerate, pivalate, caproate, isobutylacetate, t-butyl-acetate, caprylate, heptanoate, pelargonate, undecanoate, oleate, octoate, palmitate, myristate, margarate, stearate, arachidonate and tricosanoate.
In one embodiment, the alkali metal containing compound is an alkali metal halide; preferably the halide is chloride, bromide or iodide. More preferably the alkali metal halide is LiCl, NaCl or KCl.
In another embodiment the alkali metal containing compound is an alkali metal borate, bicarbonate, carbonate, chlorate, nitrate, phosphate, sulfate, sulfide, sulfite, polysulfide or thiocyanate, silicate, aluminate, phosphonate, sulfonate, cyanate, thiolate, thiophenoxide, thiocarboxylate, thiophosphate, imide salt, or similar alkali metal salt.
In another embodiment, the alkali metal containing compound is an alkali metal ion complexed with coordinating compounds such as with crown ethers, cryptands, aza-crowns, polyglycols, or compounds containing two or more ketone or aldehyde groups.
The alkali metal containing accelerator compounds of the invention may be used alone, in combination with each other, or in combination with other accelerator compounds known in the art. Other known general classes of accelerator compounds include, but are not limited to phosphine compounds, phosphonium salts, imidazoles, imidazolium salts, amines, ammonium salts, and diazabicyclo compounds as well as their tetraphenylborates salts, phenol salts and phenol novolac salts. Examples of suitable accelerator compounds to be used in combination with the accelerator compound of the invention also include those compounds listed in U.S. Pat. No. 6,255,365, incorporated herein by reference.
Resin Compositions
In the resin compositions of the invention, the epoxy resin, curing agent, and alkali metal containing accelerator compound may optionally be dissolved in a solvent. Preferably the concentration of solids in the solvent is at least about 50 percent and no more than about 80 percent solids. Non-limiting examples of suitable solvents include ketones, alcohols, water, glycol ethers, aromatic hydrocarbons and mixtures thereof. Preferred solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylpyrrolidinone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, methyl amyl ketone, methanol, isopropanol, toluene, xylene, dimethylformamide (DMF) and the like. A single solvent may be used, but also separate solvents may be used for one or more components. Preferred solvents for the epoxy resins are ketones, including acetone, methylethyl ketone and the like. Preferred solvents for the curing agents include, for example, ketones, amides such as dimethylformamide (DMF), ether alcohols such as methyl, ethyl, propyl or butyl ethers of ethylene glycol, diethylene glycol, propylene glycol or dipropylene glycol, ethylene glycol monomethyl ether, or 1-methoxy-2-propanol. Preferred solvents for the accelerators of the invention include alcohols, ketones, water, dimethylformamide (DMF), glycol ethers such as propylene glycol monomethyl ether or ethylene glycol monomethyl ether, and combinations thereof.
The amount of accelerator utilized is an amount effective to catalyze the reaction of the epoxy resin with the curing agent. As is known in the art, the amount of accelerator to be utilized depends upon the components utilized in the compositions, the processing requirements, and the performance targets of the articles to be manufactured. In one embodiment the accelerator of the invention is utilized in the range of 0.00001 to 0.1 and preferably in the range of 0.0002 to 0.02 molar equivalents per 100 grams of epoxy resin solids. In another embodiment, the accelerator of the invention is utilized in an amount greater than 0.00001 molar equivalents per 100 grams of epoxy resin solids. For purposes herein molar equivalents of the accelerator relate to the alkali metal functionality. For example, sodium hydroxide and sodium chloride are monofunctional and the dialkali metal salt of bisphenol A would be difunctional.
The resin compositions of the invention may also include optional constituents such as inorganic fillers and additional flame retardants, for example antimony oxide, octabromodiphenyl oxide, decabromodiphenyl oxide, and other such constituents as is known in the art including, but not limited to, dyes, pigments, surfactants, flow control agents and the like.
In one embodiment, the resin composition of the invention includes: (1) an epoxy resin, prepared from the reaction of an epihalohydrin and a phenol or a phenol type compound, as described above, which is preferably a brominated epoxy resin; (2) an alkali metal containing cure accelerator represented by Formula 1 a where M is lithium, sodium or potassium, preferably sodium or potassium, and R is hydrogen or a C 1 to C 12 hydrocarbyl group, preferably a methyl, ethyl, or phenyl group and more preferably a methyl group; and (3) a curing agent. Preferably, in this embodiment, the alkali metal containing cure accelerator is selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium methoxide, potassium methoxide, lithium methoxide, and combinations thereof.
In one embodiment, the resin composition of the invention includes: (1) an epoxy resin, prepared from the reaction of an epihalohydrin and a phenol or a phenol type compound, as described above, which is preferably a brominated epoxy resin; (2) an alkali metal containing cure accelerator that is an alkali metal carboxylate represented by Formula 2a where M is lithium, sodium or potassium, preferably sodium or potassium, and R is hydrogen or a C 1 to C 20 alkyl group; and (3) a curing agent.
In one embodiment, the resin composition of the invention includes: (1) an epoxy resin, prepared from the reaction of an epihalohydrin and a phenol or a phenol type compound, as described above, which is preferably a brominated epoxy resin; (2) an alkali metal containing compound which is an alkali metal ion complexed with coordinating compounds such as with crown ethers, cryptands, aza-crowns, polyglycols, or compounds containing two or more ketone or aldehyde groups.; and (3) a curing agent.
In one embodiment, the resin composition of the invention includes: (1) an epoxy resin, prepared from the reaction of an epihalohydrin and an phenol or a phenol type compound, as described above, and is preferably a brominated epoxy resin; (2) an alkali metal containing cure accelerator that is an alkali metal halide, carbonate, bicarbonate, acetate, nitrate, sulfate, sulfite, chlorate, or thiocyanate where the alkali metal is lithium, sodium or potassium, preferably sodium or potassium; and (3) a curing agent.
Resin compositions prepared utilizing the epoxy resin cure accelerators of the invention may be impregnated upon a reinforcing material to make laminates, such as electrical laminates. The reinforcing materials which may be coated with the compositions of this invention include any material which would be used by one skilled in the art in the formation of composites, prepregs, laminates and the like. Examples of appropriate substrates include fiber-containing materials such as woven cloth, mesh, mat, fibers, and the like, and unwoven aramid reinforcements such as those sold under the trademark THERMOUNT, available from DuPont, Wilmington, Del. Preferably, such materials are made from glass, fiberglass, quartz, paper, which may be cellulosic or synthetic, a thermoplastic resin substrate such as aramid reinforcements, polyethylene, poly(p-phenyleneterephthalamide), polyester, polytetrafluoroethylene and poly (p-phenylenebenzobisthiazole),carbon, graphite, ceramic or metal and the like. Preferred materials include glass or fiberglass, in woven cloth or mat form.
Compositions containing the alkali metal containing accelerators of the invention may be contacted with an article by any method known to those skilled in the art. Examples of such contacting methods include powder coating, spray coating, die coating, roll coating, resin infusion process, and contacting the article with a bath containing the composition. In a preferred embodiment the article is contacted with the composition in a varnish bath.
In one embodiment, the reinforcing material is contacted with a varnish bath comprising the epoxy resin composition of the invention dissolved and intimately admixed in a solvent or a mixture of solvents. The coating occurs under conditions such that the reinforcing material is coated with the epoxy resin composition. Thereafter the coated reinforcing materials are passed through a heated zone at a temperature sufficient to cause the solvents to evaporate, but below the temperature at which the resin composition undergoes significant cure during the residence time in the heated zone.
The reinforcing material preferably has a residence time in the bath of from 1 second to 300 seconds, more preferably from 1 second to 120 seconds, and most preferably from 1 second to 30 seconds. The temperature of such bath is preferably from 0° C. to 100° C., more preferably from 10° C. to 40° C. and most preferably from 15° C. to 30° C. The residence time of the coated reinforcing material in the heated zone is from 0.1 to 15 min, more preferably from 0.5 to 10 min, and most preferably from 1 to 5 min.
The temperature of such zone is sufficient to cause any solvents remaining to volatilize away yet not so high as to result in a complete curing of the components during the residence time. Preferable temperatures of such zone are from 80° C. to 250° C., more preferably from 100° C. to 225° C., and most preferably from 150° C. to 210° C. Preferably there is a means in the heated zone to remove the solvent, either by passing an inert gas through the oven, or drawing a slight vacuum on the oven. In many embodiments the coated materials are exposed to zones of increasing temperature. The first zones are designed to cause the solvent to volatilize so it can be removed. The later zones are designed to result in partial cure of the polyepoxide (B-staging).
One or more sheets of prepreg are preferably processed into laminates optionally with one or more sheets of electrically-conductive material such as copper. In such further processing, one or more segments or parts of the coated reinforcing material are brought in contact with one another and/or the conductive material. Thereafter, the contacted parts are exposed to elevated pressures and temperatures sufficient to cause the epoxy resin to cure wherein the resin on adjacent parts react to form a continuous epoxy resin matrix between and about the reinforcing material. Before being cured the parts may be cut and stacked or folded and stacked into a part of desired shape and thickness. The pressures used can be anywhere from about 1 to about 1000 psi with from about 10 to about 800 psi being preferred. The temperature used to cure the resin in the parts or laminates, depends upon the particular residence time, pressure used, and resin used. Preferred temperatures which may be used are between about 100° C. and about 250° C., more preferably between about 120° C. and about 220° C., and most preferably between about 150° C. and about 190° C. The residence times are preferably from about 10 min to about 120 min, more preferably from about 20 to about 90 min, and most preferably from about 30 to about 50 min.
In one embodiment, the process is a continuous process where the reinforcing material is taken from the oven and appropriately arranged into the desired shape and thickness and pressed at very high temperatures for short times. In particular such high temperatures are from about 180° C. to about 250° C., more preferably about 190° C. to about 210° C., at times of about 1 to about 10 min and from about 2 to about 5 min. Such high speed pressing allows for the more efficient utilization of processing equipment. In such embodiments the preferred reinforcing material is a glass web or woven cloth.
In some embodiments it is desirable to subject the laminate or final product to a post cure outside of the press. This step is designed to complete the curing reaction. The post cure is usually performed at from 130° C. to 220° C. for from 20 to 200 minutes. This post cure step may be performed in a vacuum to remove any components which may volatilize.
The resin compositions of the invention, due to their thermal properties, are especially useful in thee preparation of articles for high temperature continuous use applications. Examples include electrical laminates and electrical encapsulation. Other examples include molding powders, coatings, structural composite parts and gaskets.
The epoxy resin compositions described herein may be found in various forms. In particular, the various compositions described may be found in powder form, hot melt, or alternatively in solution or dispersion. In those embodiments where the various compositions are in solution or dispersion, the various components of the composition may be dissolved or dispersed in the same solvent or may be separately dissolved in a solvent or solvents suitable for that component, then the various solutions are combined and mixed. In those embodiments wherein the compositions are partially cured or advanced, the compositions of this invention may be found in a powder form, solution form, or coated on a particular substrate.
The laminates prepared utilizing the cost effective alkali metal containing accelerators of the invention exhibit enhanced thermal properties when compared to laminates utilizing prior art accelerators, such as for example imidazoles. In another embodiment, laminates prepared utilizing the accelerators of the invention exhibit enhanced thermal properties, such as delamination time, delamination temperature, solder resistance and/or thermal degradation temperature, while maintaining a glass transition temperature (Tg) similar to laminates utilizing prior art accelerators, such as, for example, imidazoles. In another embodiment, in addition to the above, the Tg is maintained in ° C., measured by differential scanning calorimetry at a heating rate of 20° C./min, of at least 90% of that for comparable systems prepared utilizing imidazole accelerators. As utilized herein, Tg refers to the glass transition temperature of the thermosettable resin composition in its current cure state. As the prepreg is exposed to heat, the resin undergoes further cure and its Tg increases, requiring a corresponding increase in the curing temperature to which the prepreg is exposed. The ultimate, or maximum, Tg of the resin is the point at which essentially complete chemical reaction has been achieved. “Essentially complete” reaction of the resin has been achieved when no further reaction exotherm is observed by differential scanning calorimetry (DSC) upon heating of the resin.
The time to delamination of laminates prepared utilizing the alkali metal containing accelerators of the invention as measured with a thermomechanical analyzer at a heating rate of 10° C./min to 260° C. (T 260 ) increases by at least 10%, preferably at least 20%, more preferably at least 50% relative to the delamination time for laminates manufactured utilizing imidazole accelerators, or the delamination time at 288° C. (T 288 ) increases by at least 5%, preferably at least 20%, more preferably at least 100% relative to the delamination time when compared to laminates manufactured utilizing imidazole accelerators, or the delamination time at 350° C. (T 350 ) increases by at least 2%, preferably at least 10% relative to the delamination time when compared to laminates manufactured utilizing imidazole accelerators.
In addition, and referring to the Examples, when compared to prior art formulations containing imidazoles, such as 2-methyl imidazole, the laminates from the compositions of the invention also show measurable improvement in the thermal properties of solder float resistance, the time to sudden and irreversible delamination (constant temperature and constant heat rate test conditions), and/or the temperature at which 5% of the sample weight is lost upon heating.
In addition to enhanced thermal properties, and again referring to the Examples, the non-thermal properties of the laminates prepared from the compositions of the invention, such as water absorption, a copper peel strength, dielectric constant, and dissipation factor are comparable with those of prior art formulations utilizing an imidazole accelerator.
In order to provide a better understanding of the present invention including representative advantages thereof, the following examples are offered.
EXAMPLES
Epoxy resin formulations were prepared by dissolving the individual resin, curing agent, and accelerator components in suitable solvents at room temperature and mixing the solutions. Varnish gel times were measured with a hot plate at 171° C. using a test method similar to IPC-TM-650 Number 2.3.18. Prepregs were prepared by coating the accelerated resin varnish on style 7628 glass cloth (BGF 643 finish) and drying in a laboratory convection oven at 163° C. for 2-10 minutes to evaporate the solvents and advance the reacting epoxy/curing agent mixture to a non-tacky B-stage.
Laminates were prepared using 1-8 prepreg plies sandwiched between sheets of copper foil (Gould JTC, 1 ounce/ft 2 ) and pressing at 100 psi with the following cure cycle: (1) heat from room temperature to 350° F. at 10° F./min, (2) hold for 60 minutes, and (3) cool at 20° F./min to 100° F. Prepreg resin flow during lamination was calculated for 4-ply, 4-inch square laminates as the percent laminate weight decrease due to the flow of resin out the laminate edge, similar to IPC-TM-650 Number 2.3.17. In general, prepreg resin flow values of 10-15% were targeted.
Laminate glass transition temperatures (Tg) were measured by differential scanning calorimetry (DSC) at a heating rate of 20° C./min. Time to delamination measurements were performed at 260, 288, or 350° C. with a thermomechanical analyzer (TMA) by heating copper clad samples at 110° C./min to the desired temperature and holding the samples at that temperature until a sudden and irreversible delamination occurred (in accordance with IPC-TM-650 Number 2.4.24.1). Similarly, TMA delamination temperatures were measured by heating copper clad samples at 110° C./min until a sudden and irreversible delamination occurred. A third method used to quantify thermal stability was to measure the temperature at which a laminate sample lost a specified weight fraction, 5% in this case. This test was performed on samples without the copper cladding using a thermogravimetric analyzer (TGA) with an air environment and a heating rate of 110° C./min.
Other laminate properties measured were water absorption (IPC-TM-650 Number 2.6.2.1 and 2.6.16), copper peel strength (IPC-TM-650 Number 2.4.8 Condition A), dielectric constant (permittivity) and dissipation factor (loss factor) (IPC-TM-650 Number 2.5.5.2), and solder float resistance at 288 and 300° C. as measured by the time to delamination (similar to IPC-TM-650 Number 2.4.13.1). This latter test was only performed on single ply laminates.
Several different resin and curing agent systems were tested to verify the performance increase provided by the invention presented here and these systems are summarized by the following examples. However, one skilled in the art would expect the present invention to provide improved performance for similar resin and curing agent systems.
Example 1
Varnish formulations typical of conventional FR-4 laminate systems were prepared with 125 parts by weight (pbw) of an 80% solution of a brominated epoxy resin (the reaction product of diglycidyl ether of bisphenol A and tetrabromobisphenol A, such as EPON Resin 1124-A-80 (available from Resolution Performance Products LLC, Houston, Tex.) 28 parts of a 10% by weight solution of dicyandiamide dissolved in dimethylformamide, and 18 parts of acetone. To the varnishes were added one of the following accelerator solutions: (1) 0.9 parts of a 10% by weight solution of 2-methylimidazole (2-MI) dissolved in propylene glycol monomethyl ether or (2) 0.45 parts of a 10% solution of sodium hydroxide (NaOH) dissolved in ethylene glycol monomethyl ether. Prepregs and 8-ply laminates (12 in.×12 in.) were prepared as described above. The resulting laminates were tested as reported in Table 1.
TABLE 1
Effects of Sodium Hydroxide Accelerator on FR-4 Laminate Performance
Comp
Property
1-1
1-2
Accelerator Component
2-MI
NaOH
Accelerator Level, 10% in solvent (pbw)
0.9
0.45
Varnish Gel Time (seconds at 171° C.)
172
193
Laminate Thickness (mm)
1.5
1.4
Laminate Tg (° C.)
139
136
T-260 Time to Delamination (minutes)
18
24
TMA Delamination Temperature (° C.)
304
312
TGA, 5% Weight Loss in Air (° C.)
310
316
Solder Float, Time to Delamination at 288° C. (sec)
192
229
Moisture Absorption, 24 Hours at 23° C. (wt. %)
0.15
0.10
Moisture Absorption, 1 Hour in 15 psi steam (wt. %)
0.39
0.39
Copper Peel Strength (lbs/in)
11.3
11.2
Dielectric Constant at 1 MHz, 23° C.
4.8
4.7
Dissipation Factor at 1 MHz, 23° C.
0.014
0.014
Comparative system 1-1 represents the state of technology today for FR-4 laminates, namely a brominated BPA epoxy resin cured with dicyandiamide and accelerated with an imidazole compound. Replacing the imidazole accelerator in the comparative system with sodium hydroxide provided increased thermal resistance (as indicated by improvements in delamination time at 260° C., TMA delamination temperature, 5% weight loss temperature, and solder float resistance) without sacrificing general laminate performance (Tg, moisture resistance, copper peel, and electrical properties).
Example 2
Varnish formulations typical of conventional FR-4 laminate systems were prepared with 125 parts by weight of an 80% solution of a brominated epoxy resin (the reaction product of diglycidyl ether of bisphenol A and tetrabromobisphenol A, such as EPON Resin 1124-A-80), 28 or 30 parts of a 10% by weight solution of dicyandiamide dissolved in dimethylformamide, and 12-20 parts of acetone. To the varnishes were added one of the following accelerator solutions: (1) a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether or (2) a 10% by weight solution of potassium hydroxide (KOH) dissolved in ethylene glycol monomethyl ether. Prepregs and 4-ply laminates were prepared as described above. The resulting laminates were tested as reported in Table 2.
TABLE 2
Effects of Potassium Hydroxide Accelerator on FR-4
Brominated Resin Performance
Comp
Comp
Property
2-1
2-2
2-3
2-4
Accelerator Component
2-MI
KOH
2-MI
KOH
Accelerator Level,
1.0
1.0
1.0
0.85
10% in solvent (pbw)
Dicyandiamide, 10% in DMF (pbw)
28
28
30
30
Varnish Gel Time
190
189
164
167
(seconds at 171° C.)
Prepreg Resin Flow (wt. %)
11
8
9
9
Laminate Tg (° C.)
136
136
138
135
T-260 Time to Delamination
13
17
16
19
(minutes)
Replacing the imidazole accelerator in both comparative formulations with potassium hydroxide gave increased thermal resistance as measured by delamination time at 260° C. while maintaining comparable laminate glass transition temperature.
Example 3
Varnish formulations typical of conventional FR-4 laminate systems were prepared with 125 parts by weight of an 80% solution of a brominated epoxy resin (the reaction product of diglycidyl ether of bisphenol A and tetrabromobisphenol A, such as EPON Resin 1124-A-80), 28 parts of a 10% by weight solution of dicyandiamide dissolved in dimethylformamide, and 14-22 parts of acetone. To the varnishes were added one of the following accelerator solutions: (1) 0.8 parts of a 10% by weight solution of lithium hydroxide (LiOH) dissolved in a 54/46 by weight blend of methanol and water, (2) 1.4 parts of a 10% by weight solution of potassium methoxide (KOCH 3 ) dissolved in methanol, (3) 7.0 parts of a 10% by weight solution of DABCO® T-45 (a 60% solution of potassium 2-ethylhexanoate in a glycol mixture from Air Products) dissolved in ethylene glycol monomethyl ether, or (4) 1.0 parts of a 10% by weight solution of lithium chloride (LiCl) dissolved in methanol. Prepregs and 4-ply laminates were prepared as described above. The resulting laminates were tested as reported in Table 3.
TABLE 3
Effects of Various Accelerators on FR-4 Brominated Resin Performance
Property
3-1
3-2
3-3
3-4
Accelerator Component
LiOH
KOCH 3
DABCO T-45
LiCl
Accelerator,
0.8
1.4
7.0
1.0
10% in solvent (pbw)
Varnish Gel Time
180
176
145
192
(seconds at 171° C.)
Prepreg Resin Flow (wt. %)
16
8
2
10
Laminate Tg (° C.)
136
134
132
129
T-260 Time to Delamination
18
23
16
16
(min)
Relative to the comparative formulation (System 2-1), all of the systems in Table 3 provide increased thermal resistance as measured by delamination time at 260° C., with the formulations accelerated by lithium hydroxide and potassium methoxide providing comparable laminate Tg values to that of the control.
Example 4
Varnish formulations typical of a high Tg, FR-4 laminate system were prepared with 118 parts by weight of an 85% solution of a high Tg, brominated epoxy resin (an epoxy-terminated polymer with oxazolidone, bisphenol A, and tetrabromobisphenol A backbone character and with an epoxide equivalent weight of 310 g/eq), 27 parts of a 10% by weight solution of dicyandiamide dissolved in dimethylformamide, and 0-6 parts by weight of acetone. To the varnishes were added one of the following accelerator solutions: (1) 6.0 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether, (2) 4.6 parts of a 10% by weight solution of sodium hydroxide dissolved in ethylene glycol monomethyl ether, (3) 6.0 parts of a 10% by weight solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether, or (4) a combination of 2.0 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether and 3.7 parts of a 10% solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether. Prepregs and 4-ply laminates were prepared as described above. The resulting laminates were tested as reported in Table 4.
TABLE 4
Effects of Hydroxide Accelerators on the Performance
of a High Tg Brominated Resin
Comp
Component
4-1
4-2
4-3
4-4
Accelerator
2-MI
NaOH
KOH
2-MI + KOH
Accelerator,
6.0
4.6
6.0
2.0 + 3.7
10% in solvent (phr)
Varnish Gel Time
197
209
190
222
(seconds at 171° C.)
Prepreg Resin Flow (wt. %)
14
12
4
13
Laminate Tg (° C.)
177
173
176
179
T-260 Time to Delamination
4
11
9
8
(min)
Relative to the comparative system 4-1, replacing all or part of the imidazole accelerator with an alkali metal hydroxide accelerator as shown in Table 4 resulted in an increase in thermal resistance while maintaining comparable laminate Tg.
Example 5
Varnish formulations were prepared with 51 parts by weight of a diglycidyl ether of bisphenol A (epoxide equivalent weight of 187 g/eq), 35 parts by weight tetrabromobisphenol A, 14 parts by weight of a phenol novolac (number average molecular weight of 750 g/mol), 24-26 parts by weight of acetone, and 17-18 parts by weight of methyl ethyl ketone. Similar to Example 1, this varnish formulation is representative of some commercial systems used for FR-4 laminate applications, especially those offering improved laminate thermal resistance. To the varnish formulations were added one of the following accelerator solutions: (1) 1.2 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether or (2) 3.6 parts of a 10% solution of potassium methoxide dissolved in methanol. Prepregs and 8-ply laminates (12 in. by 12 in.) were prepared as described above. The resulting laminates were tested as reported in Table 5.
TABLE 5
Effects of Potassium Methoxide Accelerator
on FR-4 Laminate Performance
Comp
Property
5-1
5-2
Accelerator Component
2-MI
KOCH 3
Accelerator Level, 10% in solvent (pbw)
1.2
3.6
Varnish Gel Time (seconds at 171° C.)
180
195
Laminate Thickness (mm)
1.5
1.5
Laminate Tg (° C.)
138
141
T-288 Time to Delamination (minutes)
18
84
TMA Delamination Temperature (° C.)
334
360
TGA, 5% Weight Loss in Air (° C.)
338
359
Solder Float, Time to Delamination at 288° C. (min)
11
>19
Solder Float, Time to Delamination at 300° C. (min)
5
>30
Moisture Absorption, 24 Hours at 23° C. (wt. %)
0.10
0.11
Moisture Absorption, 1 Hour in 15 psi steam (wt. %)
0.21
0.36
Copper Peel Strength (lbs/in)
9.8
9.5
Dielectric Constant at 1 MHz, 23° C.
4.9
4.9
Dissipation Factor at 1 MHz, 23° C.
0.014
0.013
While the comparative system 5-1 provides excellent thermal resistance, the performance is further improved by replacing the imidazole accelerator with potassium hydroxide. Relative to System 5-1, System 5-2 provides significantly increased thermal resistance (as indicated by improvements in delamination time at 288° C., TMA delamination temperature, 5% weight loss temperature, and solder float resistance) without sacrificing general laminate performance (Tg, moisture resistance, copper peel, and electrical properties). This result demonstrates application of the invention to curing agents with phenolic hydroxyl moieties.
Example 6
Varnish formulations were prepared with 51 parts by weight of a diglycidyl ether of bisphenol A (epoxide equivalent weight of 187 g/eq), 35 parts by weight tetrabromobisphenol A, 14 parts by weight of a phenol novolac (number average molecular weight of 750 g/mol), 5-10 parts by weight of acetone, and 35-43 parts by weight of methyl ethyl ketone. To the varnishes were added one of the following accelerator solutions: (1) 1.2 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether, (2) 3.6 parts of a 10% solution of potassium methoxide dissolved in methanol, (3) 2.9 parts of a 10% solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether, (4) 5.5 parts of a 20% solution of DABCO T-45 dissolved in ethylene glycol monomethyl ether, or (5) 4.0 parts of a 10% solution of sodium carbonate (Na 2 CO 3 ) dissolved in water. Prepregs and 4-ply laminates were prepared as previously described. The resulting laminates were tested as reported in Table 6.
TABLE 6
Effects of Various Accelerators on Brominated Resin Performance
Property
Comp 6-1
6-2
6-3
6-4
6-5
Accelerator Component
2-MI
KOCH 3
KOH
DABCO T-45
Na 2 CO 3
Accelerator Level, 10% in solvent (pbw)
1.2
3.6
2.9
5.5*
4.0
Varnish Gel Time (seconds at 171° C.)
187
185
197
208
192
Prepreg Resin Flow (wt. %)
13
13
16
10
18
Laminate Tg (° C.)
136
139
136
134
137
T-288 Time to Delamination (minutes)
16
65
63
65
63
*20% solution by weight
Increased thermal resistance as measured by delamination time at 288° C. was obtained by replacing the imidazole accelerator typically used in the comparative formulation (System 6-1) with a variety of accelerators as listed in Table 6. In all cases, laminate Tg values were similar to the comparative formulation.
Example 7
Varnish formulations were prepared with two commercially available, brominated epoxy resin/curing agent systems used for laminating applications: (1) 125 parts by weight of EPON Resin 1213-B-80 (an 80% solids solution in methyl ethyl ketone consisting of epoxy resin and phenolic curative materials with a nominal epoxide equivalent weight of 375 g/eq, available from Resolution Performance Products LLC, Houston, Tex.) or (2) 142.9 parts by weight of EPON Custom Solution 373 (a 70% solids solution in methyl ethyl ketone and propylene glycol monomethyl ether consisting of epoxy resin and phenolic curative materials with a nominal epoxide equivalent weight of 380 g/eq, available from Resolution Performance Products LLC, Houston, Tex.). To the resin systems were added additional ketone solvents to lower the varnish viscosity and one of the following accelerator solutions: (1) a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether or (2) a 10% solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether. Prepregs and 4-ply laminates were prepared as described above. The resulting laminates were tested as reported in Table 7.
TABLE 7
Effects of Potassium Hydroxide Accelerator on
Brominated Resin Performance
Comp
Comp
Property
7-1
7-2
7-3
7-4
Resin/Curing Agent Material
1213
1213
CS 373
CS 373
Accelerator Component
2-MI
KOH
2-MI
KOH
Accelerator Level,
1.19
2.94
0.89
1.40
10% in solvent (pbw)
Varnish Gel Time
189
182
122
116
(seconds at 171° C.)
Prepreg Resin Flow (wt. %)
17
17
11
9
Laminate Tg (° C.)
140
146
165
172
T-288 Time to Delamination
18
63
32
63
(minutes)
For both the standard and high Tg, brominated resin systems, replacing the imidazole cure accelerator with potassium hydroxide gave similar processing characteristics (gel time and flow), slightly increased laminate glass transition temperature, and significantly increased thermal resistance as measured by time to delamination at 288° C.
Example 8
Varnish formulations were prepared with EPON Custom Solution 360, a commercially available, epoxy resin/curing agent system used for structural composite applications. To 125 parts by weight of EPON Custom Solution 360 (an 80% solids solution in methyl ethyl ketone consisting of epoxy resin and phenolic curative materials with a nominal weight per epoxide of 310 g/eq, available from Resolution Performance Products LLC, Houston, Tex.) were added 15 parts by weight of methyl ethyl ketone, 10 parts by weight of propylene glycol monomethyl ether, and one of the following accelerator solutions: (1) 1.2 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether or (2) 1.8 parts of a 10% solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether. Prepregs and 4-ply laminates were prepared as described above. The resulting laminates were tested as reported in Table 8.
TABLE 8
Effects of Potassium Hydroxide Accelerator
on Structural Resin Performance
Property
Comp 8-1
8-2
Accelerator Component
2-MI
KOH
Accelerator Level, 10% in solvent (pbw)
1.2
1.8
Varnish Gel Time (seconds at 171° C.)
123
126
Prepreg Resin Flow (wt. %)
13
16
Laminate Tg (° C.)
164
167
T-350 Time to Delamination (minutes)
51
65
As has been demonstrated for a variety of resin and curing agent systems, replacing the 2-methylimidazole cure accelerator with potassium hydroxide resulted in similar formulation processing behavior, similar laminate Tg, and an increase in thermal resistance as measured by the delamination time at 350° C.
Example 9
As taught by U.S. Pat. No. 4,251,594, a brominated resin was prepared by reacting 53.92 parts by weight of a diglycidyl ether of bisphenol A (epoxide equivalent weight of 187 g/eq) with 21.07 parts tetrabromobisphenol A and 0.076 parts potassium hydroxide. The resulting fusion product (epoxide equivalent weight of 355 g/eq) was dissolved in acetone to 74.5% solids.
Varnish formulations were prepared with 134.2 parts by weight of a 74.5% solution of the brominated epoxy resin described above and 30 parts of a 10% by weight solution of dicyandiamide dissolved in dimethylformamide. To the varnishes were added one of the following accelerator solutions: (1) 1.24 parts of a 10% by weight solution of 2-methylimidazole dissolved in propylene glycol monomethyl ether or (2) 1.43 parts of a 10% by weight solution of potassium hydroxide dissolved in ethylene glycol monomethyl ether. Prepregs and 4-ply laminates were prepared. The resulting laminates were tested as listed in Table 9.
TABLE 9
Effects of Potassium Hydroxide Accelerator on the Performance
of a Resin Described in U.S. Pat. No. 4,251,594
Property
Comp 9-1
9-2
Accelerator Component
2-MI
KOH
Accelerator Level, 10% in solvent (pbw)
1.24
1.43
Varnish Gel Time (seconds at 171° C.)
180
165
Prepreg Resin Flow (wt. %)
18
18
Laminate Tg (° C.)
140
143
T-260 Time to Delamination (minutes)
16
24
Replacing the imidazole accelerator in the comparative formulation with potassium hydroxide gave increased thermal resistance as measured by delamination time at 260° C. and a slight increase in laminate glass transition temperature. Thus, when used as a cure accelerator, potassium hydroxide provided increased thermal resistance even for a fusion resin prepared with potassium hydroxide as the fusion catalyst.
While the present invention has been described and illustrated by reference to particular embodiments, those of ordinary skill in the art will appreciate that the invention lends itself to variations not necessarily illustrated herein. For example, the alkali metal containing compound may be added as such or generated in-situ in the compositions of the invention. For this reason, then, reference should be made solely to the appended claims for purposes of determining the true scope of the present invention.
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Disclosed are epoxy resin compositions which include an alkali metal containing cure accelerator. The alkali metal containing cure accelerators are preferably alkali metal hydroxides, alkoxides, carboxylates, or alkali metal salts. Articles prepared from the resin compositions of the invention exhibit enhanced thermal properties, and similar non-thermal properties, when compared to articles prepared from compositions including other accelerators such as imidazoles. The resin compositions of the invention may be used for any purpose, but are particularly suited to be utilized in the manufacture of laminates for printed circuit boards and non-electrical structural applications.
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BACKGROUND OF THE INVENTION
This invention relates generally to HVAC control components. More specifically this invention relates to an enthalpy sensor providing on/off output and externally controllable on-off setpoints.
Enthalpy sensors are used to provide an economizer function for heating and cooling systems, and indoor/outdoor air mixture systems. An enthalpy sensor measures air temperature and humidity to determine the most efficient mix of indoor and outdoor air to provide to a space. Enthalpy sensors typically provide an analog output or outputs to a control device. The control device then makes decisions regarding the air mixture, based on the enthalpy sensor signal or signals. Some devices provide temperature and humidity signals to a vent motor control circuit. In such a system the temperature and humidity signals are individually provided to a processor which calculates enthalpy from the separate temperature and humidity signals. The setpoint for enthalpy in such a device is in the motor control circuit, where it may be adjusted based on air circulation requirements or other factors. It is more convenient to locate the setpoint control in the motor control circuit, since the enthalpy sensor itself may be located in a location inconvenient for such adjustments. The enthalpy sensor may for instance be located on a rooftop.
In other systems, the enthalpy signal may be calculated in the enthalpy device itself, and a current or voltage representing the enthalpy is then supplied to the external motor control circuit. In these systems it may or may not be possible to externally control the enthalpy setpoint at the controller.
Since enthalpy systems must measure temperature to determine enthalpy, components which cause temperature variations internal to the sensor will add an undesirable error in sensor readings. In some cases it may be possible to compensate for this error component. Doing so however, requires additional components to eliminate the error. Consequently, the error may only be eliminated at increased cost to the sensor.
The prior art methods of measuring enthalpy suffer from two major drawbacks. First, prior art enthalpy systems which provide an analog current output signal require extra parts to produce this analog output. These parts increase significantly the cost of the device, as well as its overall size. Secondly, prior art enthalpy systems produce undesirable heating of the enthalpy sensor. Such heating causes errors in the enthalpy output. While correction is possible for this effect, it can only be achieved at increased cost to the system, and is difficult to achieve since the self heating causes errors in both the temperature and humidity sensor signals.
SUMMARY OF THE INVENTION
Accordingly, the present system provides an enthalpy sensor without the cost or temperature variations associated with analog current output circuitry.
The present invention provides an on/off output which reflects the result of a comparison between the enthalpy level of a space and a predetermined setpoint. The sensor combines a signal representative of humidity with a signal representative of temperature to create a signal representative of enthalpy. The signal representative of enthalpy is compared with a predetermined setpoint to determine if the enthalpy level is above or below the setpoint. An output is then produced which indicates whether the output representative of enthalpy is above or below the predetermined setpoint.
One object of the invention accordingly is to provide an enthalpy sensor with reduced component cost compared with prior art methods, while providing a comparable quality enthalpy sensor. A second object of the invention is to provide an enthalpy sensor with little or no temperature variation problems caused by the analog current output signal components. A further object of the invention is to provide remote access to the enthalpy setpoints.
Further objects of the invention will become apparent to one skilled in the art with examination of the specification, drawings and claims below.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the preferred embodiment of the enthalpy sensor circuit.
FIG. 2 shows the relationship between humidity and temperature with respect to the output of op-amp 14 of FIG. 1.
FIG. 3 repeats the graph of FIG. 2 on a Psychometric chart.
FIG. 4a shows the output pulse of timer 1.
FIG. 4b shows the output pulse of timer 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic diagram of the preferred embodiment of the enthalpy sensor circuit. The circuit comprises timers, 1 & 2, wherein node A of timers 1 & 2 is a reset node, node B is a trigger input node, node D is a discharge node, node E is an output node, and node F is a threshold node. Node A of timer 1 & 2 are electrically onnected to terminal 28 to provide reset on power-up. Terminal 28 is the positive voltage supply of V+. In the preferred embodiment, timers 1 & 2 are each 1/2 of an LMC556 from National Instruments, to reduce part count and overall cost. Timer 1 serves as a reference timer for timer 2 which provides a humidity dependent output at node E. Node E of timer 1 is electrically connected to node B of timer 2. Resistor 3 is electrically connected between node D of timer 1 and terminal 28. Resistor 4 is electrically connected between node D and node F of timer 1. Capacitor 5 is electrically connected between node F of timer 1 and terminal 32. Terminal 32 is the negative supply of V-. Resistors 3 & 4, and capacitor 5 collectively determine the pulse width at node E of timer 1.
Timer 2 provides an output at node E of timer 2 that is a variation of the duty cycle of the output provided by node E of timer 1. This variation is caused by changes in humidity. Capacitor 6, which is electrically connected between node F of timer 2 and terminal 32, is used to sense humidity. In the preferred embodiment, the capacitance of capacitor 6 will vary +/-50% with humidity. Resistor 7 is electrically connected between node D of timer 1 and terminal 28. Nodes D & F of timer 2 are shorted together. Resistor 7 and capacitor 6 collectively determine the pulse width at node E of timer 2.
The output from node E of timer 2 is integrated so that the square wave output of timer 2 is transformed into a voltage which varies with humidity. Integration is performed by resistor 8 and capacitor 9. Resistor 8 is electrically connected between node E of timer 2 and the positive input of op-amp 11. Capacitor 9 is electrically connected between the positive input of op-amp 11 and terminal 32.
In a preferred embodiment, low-cost thermistor 10 is electrically connected between terminal 28, and the positive input of op-amp 12. Thermistor 10 may for example be a Fenwall 175-502FAJ-001 or other device which provides a generally linear resistance varying with temperature. Thermistor 10 is chosen so that it resistance is linear over a range of temperature for which the enthalpy sensor is rated.
Resistor 33 is electrically connected between the positive input of op-amp 11 and terminal 32. Resistor 33 forms a voltage divider with thermistor 10.
Op-amps 11 and 12 may be of type LM2902 from National Instruments, or similar device. A LM2902 is preferred because the part provides four op-amps in a single package, reducing overall part count. Op-amps 11 and 12 buffer the input signals, and scale the relationship between the inputs so that one degree Fahrenheit will cause the same increase in the output voltage of op-amp 12 as a four percent change in humidity will cause in the output of op-amp 11. While other relationships between the temperature and humidity sensor inputs could be chosen, this choice of humidity to temperature provides the most acceptable control characteristic.
Feedback between the output and negative input of op-amps 11 and 12 is provided as is known to one skilled in the art. In the case of op-amp 11, resistor 13 is electrically connected between the output and negative input, while in the case of op-amp 12, a short electrically connects the output and negative input.
Op-amp 14 is the same type op-amps 11 & 12. Op-amp 14 receives an input at its negative input node from op-amps 11 & 12, and produces an analog output voltage related to enthalpy. The outputs from op-amps 11 & 12 are passed through resistors, 15 & 16 respectively, before connecting to the negative input of op-amp 14. FIGS. 2 & 3 characterize the output of op-amp 14. The straight line depicted in FIG. 2 represents a constant voltage at the output of op-amp 14 for the temperature and humidity which will produce that output. Conditions to the right of the line have higher enthalpy values. Conditions to the left of the line have lower enthalpy values. In FIG. 3 the same voltage is plotted on a Psychometric chart. Examination of the constant voltage line in FIG. 3 shows that it does not follow constant enthalpy. It follows well from saturation to about 50% RH and then turns downward. The term enthalpy is appropriate however since an enthalpy value immediately to the right of any point on the control line is always higher than the enthalpy immediately the left of that point on the control line. In fact, it is undesirable to control at constant enthalpy, since at low humidity the control point could require a temperature of over 100° F.
Gain resistor 17, and high frequency filtering capacitor 18 are connected between the output and negative input of op-amp 14. Resistors 19 is electrically connected between the positive input of op-amp 14 and terminal 28. Resistor 20 is electrically connected between the positive input of op-amp 14 and terminal 32. Resistors 19 & 20 provide a voltage divider which partially controls the overall gain of op-amp 14.
Op-amp 21 converts the analog signal from op-amp 14 into an on/off output. Resistor 34 is electrically connected between the negative input of op-amp 21 and the output of op-amp 14.
Op-amp 21 operates as a comparator. A voltage divider on the positive input of op-amp 21 is modified to select among three enthalpy setpoints. Resistors 22 & 23 are electrically connected to the positive input of op-amp 21. The other end of each resistor 22 & 23 is electrically connected to terminal 29 & 31 respectively. A second pair of resistors, 24 & 25 are electrically connected between terminals 28 & 29, and 31 & 32 respectively.
Setpoints are selected by shorting terminal 28 to 29 or 31 to 32. Either short changes the voltage divider on the positive input to op-amp 21. Changes in the voltage divider modify the voltage which will appear at the positive input of op-amp 21, and consequently switch the circuit between the three enthalpy level settings. One skilled in the art would be cognizant that more than three levels of setpoints may be provided by placing more resistors in the voltage divider circuit.
Resistor 27 is electrically connected between the output of op-amp 21 and terminal 32. Resistor 26 is electrically connected between the output of op-amp 21 and output terminal 30. Resistors 26 & 27 determine the final output voltage which will be sent to the controller.
In operation, resistors 3 & 4, and capacitor 5 will cause the output of timer 1 to produce a square wave as shown in FIG. 4a. The output pulse from node E of timer 1 is then input into node B of timer 2. The charge/discharge cycle of resistor 7 and capacitor 6 result in a square wave as shown in FIG. 4b.
Since capacitor 6 varies with humidity, the pulse width of the signal at node E of timer 2 will also vary with humidity. Resistor 8 and capacitor 9 integrate the output of timer 2, and provide a voltage representative of humidity to the input of op-amp 11. Thermistor 10 and voltage divider resistor 33 provide a voltage representative of temperature to the input of op-amp 12. Resistors 13, 15, & 16 are adjusted accordingly to provide a 4:1 ratio between the output of op-amp 11 and the output of op-amp 12. A 4:1 ratio of the outputs of op-amps 11 & 12 corresponds to the above mentioned one degree Fahrenheit to four percent humidity ratio. Resistors 17 & 20 control the output of op-amp 14 so that the voltage level will be approximately one-half way between terminals 28 & 32. This requirement is necessary for the comparator function of op-amp 21 to work properly.
As mentioned above, different setpoints can be selected by shorting either terminals 28 & 29 or 31 & 32 together. A short from terminals 28 to 29 will shift the voltage on the positive input of op-amp 21 to a higher voltage. The enthalpy-related voltage from op-amp 14 must now reach a higher voltage to trigger the output. This short consequently provides a HIGH enthalpy setting. A short between terminals 28 & 29 will shift the positive input of op-amp 21 to a lower voltage. The enthalpy-related voltage from op-amp 14 can now be a lower voltage to trigger the output. This short consequently provides a LOW enthalpy setting. If no shorts are used, a MEDIUM enthalpy setting is provided.
A controller in a central location is provided with electrical connection to terminals 28, 29, 30, 31 & 32 on the remotely located enthalpy sensor. In this way enthalpy settings may be changed, without having to go to the enthalpy sensor itself, by making the shorts described above.
Although a specific example of the applicant's enthalpy sensor has been shown and described for illustrative purposes, a number of variations and modifications within the applicant's contemplation and teaching will be apparent to those skilled in the art. It is not intended that coverage of the invention be limited to the embodiment disclosed.
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A low-cost, accurate enthalpy sensor is described. The invention provides an on/off output which reflects the result of a comparison between the enthalpy level of a space and a predetermined setpoint. The sensor combines a signal representative of humidity with a signal representative of temperature to create a signal representative of enthalpy. The signal representative of enthalpy is compared with a predetermined setpoint to determine if the enthalpy level is above or below the setpoint. An output is then produced which indicates whether the output representative of enthalpy is above or below the predetermined setpoint.
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This is a division of application Ser. No. 119,965 filed on Nov. 13, 1987 now U.S. Pat. No. 4,842,257.
TECHNICAL FIELD
This invention relates to vehicle seat suspensions and their method of manufacture and more particularly to vehicle seat assemblies which utilize an elastomeric component to support a vehicle passenger.
BACKGROUND OF THE INVENTION
Molded foam cushioning elements of the type set forth in U.S. Pat. No. 3,161,436, filed Dec. 15, 1964, have been used in automobile and vehicular applications to provide a vehicle seating assembly with both static and dynamic load supporting characteristics for passenger comfort. In such applications the element is supported by a rigid backing member forming part of the seat assembly frame for attachment to the vehicle body. In such cases the modulus of elasticity of the foam cushioning element and the thickness of the element is selected to provide a static deformation which conforms to and comfortably supports the weight/shape of different passengers. The cushioning elements have a modulus and are dimensioned to absorb dynamic impacts which are transferred through the vehicle suspension system into the seat assembly. In such cases the modulus and dimensions of the seating element are selected to absorb the impact loading without causing the foam element to fully compress and bottom out against the rigid backing member.
Such objectives can only be combined by use of foam elements with a thickness that will produce impact load absorption in a material of a modulus that has a comfortable feel under static load conditions. Such thickness of the foam element increases the weight of the vehicle seat assembly.
U.S. Pat. Nos. 2,251,318 and 4,545,614 disclose vehicle seat assemblies in which elastomeric webbing or strips are stretched between vehicle seat frame components to form a suspension for a seat cover. In the case of the '318 patent the strips are covered by a layer of foam material like spongy material which will impart static comfort to the assembly. The strap components are configured to yield to accommodate impact loads. The straps are reinforced by fabric to control against excessive deflection of natural rubber material of the straps.
The '614 patent uses strips or fibers of a material having a modulus at high deformation which is a multiple of natural rubber to control bottoming out of the suspension system. The use of strips, filaments or straps requires a cover to impart a smooth seating surface. Such covers can set to the shape of the underlying strip array following periods of use.
STATEMENT OF THE INVENTION AND ADVANTAGES
A feature of the present invention is to provide an improved seat suspension for a vehicle seat assembly which has a membrane element of block copolymer material oriented to provide a two stage modulus in the direction of the suspension span for providing a high comfort index under static load support conditions and an increasing load support characteristic for absorbing road impacts.
A further feature of the present invention is to provide an improved method for forming an elastomeric membrane for use as vehicle suspension components wherein a material of block copolymer composition is cast and extruded into sheet form with the material being tensioned during extrusion to orient the molecular structure of the material; the extruded material is then annealed to fix the material orientation for establishing a two stage modulus characteristic in the membrane.
Yet another object of the present invention is to provide a seat suspension means located between a seat cushion and a seat frame for absorbing vehicular vibrations and providing increased support in response to increased load; the seat suspension means including a membrane dimensioned to extend across substantially the full planar extent of the seat frame and including a molecular orientation of polymeric material which has a modulus greater across the width of said membrane than across the depth thereof.
Still another object of the present invention is to provide a seat suspension means located between a seat cushion and a seat frame for absorbing vehicular vibrations and providing increased support in response to increased load; the seat suspension means including a membrane dimensioned to extend across substantially the full planar extent of the seat frame and including a molecular orientation of polymeric material which is greater across the width of the membrane than across the depth thereof; the direction of orientation being aligned with the direction in which the membrane is tensioned and the orientation producing a stress to strain relationship which results in increasing load support in response to increased elongation in the direction of orientation of the membrane caused by such increased loads.
Another object of the present invention is to provide a new and improved low weight, easily assembled vehicle seat having a suspension component of membrane form which underlies a covering without interrupting smooth surface features of the covering and which is the sole component to support both static and dynamic loads.
Yet another object of the present invention is to provide a seat suspension component of the type set forth in any of the preceding objects wherein the component is a sheet form membrane made from a block copolymer consisting of polytetramethylene terephthalate polyester and polytetramethylene ether.
The present invention further resides in various novel constructions and arrangement of process steps and/or parts and further objects, novel characteristics and advantages of the present invention will be apparent to those skilled in the art to which it relates and from the following detailed description of the illustrated embodiments thereof made with reference to the accompanying drawings forming a part of this specification and in which similar reference numerals are employed to designate corresponding parts throughout the several views, and in which:
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a vehicle seat seat assembly including the present invention;
FIG. 2 is a top elevational view of a seat suspension of the present invention;
FIG. 3 is an enlarged fragmentary view of a hook detail;
FIG. 4 is a stress strain curve of a block copolymer membrane used in the present invention;
FIG. 5 is a chart of a process used in the manufacture of the membrane of the present invention; and
FIG. 6 is a top elevational view of another embodiment of the seat suspension of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a vehicle seat assembly 10 is illustrated including a back frame 12 and a seat frame 14.
The seat frame 14 includes a base tube 16 with side segments 16a, 16b joined by a front segment 16c. Suspension tubes 18, 20 are provided on either side of the seat frame 14. Each of the tubes 18, 20 include an inwardly and downwardly bent end 22 that is welded to the base tube 16 slightly inboard of the side segments 16a, 16b. An aft end 24 on each of the tubes 18, 20 is welded to brackets 26, 28, respectively. The brackets 26, 28 are located on each side of the rear of the seat frame 14. The brackets 26, 28 can be rigidly connected to the back frame 12 or can serve as a pivot point for a back frame configuration capable of being tilted with respect to the seat frame 14.
The suspension tubes 18, 20 are thereby configured to support a seat suspension 30 constructed in accordance with the present invention. The suspension 30 is representatively shown as a seat in the vehicle seat assembly but is equally suitable for use in the back portion of such seat assemblies.
The seat suspension 30 is covered with a thin layer 32 of flexible foam material or other padding which will provide a comfortable feel when a passenger is seated thereon under static load conditions. It is preferred that the conformable layer 32 have a modulus that is less than the modulus of the seat suspension. The modulus of the conformable layer 32 is also selected to enable it to conform to the shape of the passenger and transfer such shape to the seat suspension 30 where the static load is further conformed and supported in a manner to be discussed.
In the illustrated arrangement the conformable layer 30 also includes a cloth trim covering 34. The conformation layer 30 is representatively shown as including side bolsters 36 (only one illustrated). The back frame 14 supports a cloth covered sculptured foam back 38 which can be of conventional design or modified to include a suspension system such as seat suspension 30.
The use of the seat suspension 30 of the present invention enables less polyurethane foam or other padding material to be used in the vehicle seat assembly 10 and also improves both static and dynamic load support comfort of the seat assembly by absorbing high frequency low amplitude vehicular vibrations and also by absorbing large amplitude vehicle excursions resulting from severe road impacts such as the vehicle wheels hitting pot holes or the like.
In order to produce such desired results, the seat suspension 30 includes a sheet form membrane 40 made from a block copolymer of polytetramethylene terephthalate polyester and polytetramethylene ether. The material includes a combination of hard crystalline segments of the polyester and soft amorphous segments of the poly ether. Another example of a hard crystalline segment is polyethylene terephthalate polyester. Other amorphous segments can be either polyethyl ether or polypropyl ether. Annealing the material at a specific temperature while they are under tension orients the polyester molecules in one direction while leaving the poly ether molecules unaffected. As will be more specifically described, such orientation can produce a two stage stress to strain curve in which the curve has a relatively flat slope for a first range of seat suspension deflections and a relatively higher slope for a second range of seat suspension deflections.
One aspect of the present invention is to provide a process for making a sheet form membrane 40 with molecules oriented therein to produce desired stress strain characteristics. As shown in FIG. 5, the process includes the steps of preparing a mass of block copolymer material of the type specified above and maintaining it in a homogeneous state at a temperature of 260° C. by suitable mixing and heater means.
The block copolymer material is directed into an extruder with a suitable die to produce a sheet. The sheet is drawn from the extruder by pick-up rollers adjusted to speeds which maintain the sheet under tension in the direction of extrusion to produce a first axial orientation of the sheet. If desired, the sheet can be engaged by a tenter to increase the width of the sheet and maintain transverse tension thereon to produce biaxial orientation of the sheet.
The extrusion is then heated to anneal the material under tension. The biaxial orientation of the polyester molecules produces a membrane having the stress strain curve shown in FIG. 4.
The resultant membrane 40 is a strong and durable material especially suited for seat suspension applications. The seat suspension 30 equipped with the membrane 40 produces a well cushioned and comfortable ride while offering increased load support under impact conditions of the aforediscussed type. The stress strain curve 42 of the membrane 40 in a direction along the axis X--X is shown in FIG. 4. It shows that the membrane has high strength in the range of 75-280 MPa as compared to natural rubber elastomer membranes with a strength in the range of 10-20 MPa.
Further, the curve 42 at low strains has a relatively low slope portion 44. Hence, a small change in static load or small amplitude vibrations will produce a large change in elongation of the membrane 40 along the axis X--X between the portions thereof which are connected to the seat frame 14. In this range of elongation the membrane and the layer of foam thereon will feel comfortable because they easily conform to the shape of the passenger.
The curve at high strains has a very high slope portion 46 and hence the membrane will stiffen when large loads are imposed thereon by severe road impacts or the like. In such cases the seat suspension 30 will stiffen and provide excellent support without bottoming out on underlying frame components of a seat assembly.
In the illustrated embodiment of FIGS. 1-3 the side edges 48, 50 of the membrane 40 are wrapped around and heat sealed to spaced parallel metal rods 52, 54, respectively. Hooks 56 are connected to each of the rods 52, 54 at spaced locations therealong. The hooks 56 are attached to the suspension tubes 18, 20 to suspend the membrane 40 therebetween to be prestretched into a range of 10%-25% elongation to provide a desired initial load support capability.
Orientation of the membrane 40 along the axis X--X increases the modulus and the tensile strength of the membrane 40 only in the direction of orientation as seen in the case of the following Table I. The amount of increase in tensile properties is proportional to the degree of orientation.
TABLE I______________________________________Tensile Properties of Oriented HYTREL ® (a block copolymerof polytetramethylene terephthalate polyester andpolytetramethylene ether) Membranes and Filament______________________________________ ThicknessSample Orientation Comment Mil(mm)______________________________________Original No orientation 40(1.57)S.sub.1 2.25X Oriented in X 11(0.43) direction Tensile in Y directionS.sub.2 2.25X Oriented in X 14(0.58) direction Tensile in X directionD.sub.1 2.5X Oriented in 4.3(0.17) 3Y X & Y directions Tensile in X directionD.sub.2 4.4X Oriented in 3.7(0.14) 3Y X & Y directions Tensile in Y directionFilament Oriented in -- X direction Tensile in X direction______________________________________ Modulus at Tensile 100% Elong. Strength UltimateSample (MPa) (MPa) Elongation %______________________________________Original 10.3 55.7 1111S.sub.1 11.4 53.0 1328S.sub.2 50.5 107.9 220D.sub.1 29.1 102.5 333D.sub.2 66.8 130.9 195Filament -- 185.0 110______________________________________
In the embodiment of the invention shown in FIG. 6, holes 60 are introduced into a membrane 62 to provide for breathability and to provide means for adjusting the modulus of a seat suspension 64. In the illustrated embodiment the membrane 62 is oriented in the same manner as membrane 40. The holes 60 are placed in the center region of the membrane 62 without affecting the strength of the membrane in the unoriented direction perpendicular to axis X--X. Consequently, if desired the process defined above can provide an alternative step of prepunching the membrane as it leaves the extruder and prior to being tensioned and annealed.
The results of the addition of holes in a sample segment of a membrane is set forth in following Table II.
TABLE II______________________________________Tensile Strength and elongation of HYTREL ® (a blockcopolymer of polytetramethylene terephthalate polyester andpolytetramethylene ether) Membranes Oriented in theX-Direction. Some of the samples had 3 mm holes punchedin the center of the 6.35 gauge width.Direction Tensile Ultimateof Tensile Hole Strength ElongationPull Present? (MPa) (%)______________________________________X No 75 180X Yes 67 100Y No 23 925Y Yes 38 858______________________________________
From the foregoing, it should be apparent that the present invention provides a novel seat assembly of light weight and with improved static and dynamic comfort of the seat because of a full uninterrupted surface support of the passenger by means which will accommodate and conform to the shape of a passenger and which will increase in strength to support additional dynamic impact loads without bottoming out.
The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the invention may be practiced otherwise than as specifically described herein and yet remain within the scope of the appended claims.
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A vehicle seat suspension has a thin high strength elastomeric membrane. The membrane is formed from block copolymer material by a process in which a sheet is extruded and tensioned to orient molecules in a select direction with respect to the membrane; the oriented membrane is annealed to retain the orientation during cyclical deformation of the membrane. The sheet form membrane is adapted to be connected with respect to a vehicle seat assembly frame and to serve as a backing for foam seating material and wherein the oriented structure of the membrane provides a two stage modulus in the direction of the orientation for providing static and dynamic load support characteristics which impart passenger comfort without increasing the weight of a seat assembly.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 14/148,484, filed Jan. 6, 2014, the content of which is incorporated herein by reference in its entirety.
STATEMENT OF FEDERAL SUPPORT
[0002] The United States Government has rights in the invention pursuant to Contract No. DE-AC52-07NA27344 between the U.S. Department of Energy and Lawrence Livermore National Security, LLC, for the operation of Lawrence Livermore National Laboratory.
BACKGROUND
[0003] New paradigms for early detection, prevention, and control at the human-environmental interface are needed to reduce global threats from current and emerging infectious diseases. For example, better storage and transport solutions are needed for pathogen-containing samples collected from global satellite laboratories, health clinics and military hospitals treating soldiers with persistent infections. While adequate collection and storage solutions are available for immediate transport to the laboratory, these methods are extremely time sensitive and often require refrigeration and/or cold storage.
[0004] Current methodologies for pathogen recovery and identification are dependent on obtaining sterile samples, which is often complicated in the field by contamination of the material with patient or environmental flora. In addition, existing methods are dependent on the use of pathogen-specific transport media, which delays identification of new emerging biothreats in the field, where no such defined growth media exists.
[0005] Thus, a need exists for safe and convenient method for the transport of pathogens at ambient temperatures. This disclosure satisfies this need and provides related advantages as well.
SUMMARY OF THE DISCLOSURE
[0006] Free-living amoebae are present worldwide, having been isolated from soil, fresh and salt water, and air. Amoebae are phagocytic and primarily feed on bacteria, fungi and algae.
[0007] Some microorganisms have evolved to survive phagocytocis by amoebae and are known as Amoebae Resistant Microorganisms (ARM). In addition to Legionella and Mycobacterium spp., the list of ARM has recently been shown to include Mimiviruses and Enteroviruses . The amoeba, Acanthamoeba castellanii , is known to serve as a reservoir for a number of pathogenic microorganisms in nature, and to play a role in their environmental survival and dissemination. The ability of several human intracellular pathogens, including L. pneumophila and M avium , to infect and survive within A. castellanii has been well characterized. Amoebae have also been shown to support the growth of many bacteria of interest to biodefense (e.g. Francisella tularensis, Yersinia pestis, Coxiella bernetti ) as well as a number of emerging pathogens (e.g. Klebsiella pneumoniae and Pseudomonas aeroginosa ) in the laboratory. Importantly, environmental bio-surveillance programs increasingly identify amoebae containing Viable Nonculturable Organisms (VNCO), this suggests that many ARM remain to be identified and that amoebae growth may induce the intracellular bacteria to enter a metabolically dormant state.
[0008] Amoebae are known to exhibit a biphasic life style, existing as trophozoites in presence of abundant nutrients and as cysts in response to desiccation and nutrient shortage. Multiple pathogens have been shown to persist in cysts for years and then emerge in response to favorable environmental conditions when the amoebae excyst. Amoebae cysts are composed of tough cellulose-like structures that are extremely resistant to biocide and mechanical lysis, which naturally protects any enclosed pathogens. In contrast to traditional transport media, where pathogens often lose virulence factors present on extrachromosomal elements such as plasmids or transposons, a number of studies have shown that growth in amoebae supports the virulence of ARM and their ability to invade and survive in host cells. This is believed to be due to similar selective pressures present in amoebae and mammalian cells. It is currently accepted that growth in amoebae provides an opportunity for intracellular pathogens to adapt to the intracellular niche enabling them to subsequently resist killing by mammalian host cells. Development of amoeba cysts as a transport system has the advantages of using an environmentally tolerant system that supports pathogen growth and virulence and is resistant to contamination with common skin flora.
[0009] Applicant provides a method for transporting a pathogen under ambient conditions, comprising, or alternatively consisting essentially of, or yet further consisting of, culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite of the amoeba and causing the trophozoite to encyst, and then culturing under conditions that favor conversion of the amoeba cyst to a trophozoite, which can release the engulfed pathogen. In one aspect, the conditions that favor incorporation of the pathogen into the cyst of the amoeba comprises contacting the pathogen with the amoeba in an iron rich environment. Virus and/or bacteria are pathogens that can be transported by the disclosed method. Amoeba that are useful in the disclosed methods include, without limitation Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi.
[0010] Also provided by this disclosure is a substantially homogenous population or culture of amoeba trophozoites and/or cysts prepared by the above method which comprises, or alternatively consists essentially of, or yet further consists of, an exogenous pathogen encysted in a trophozoite and/or an amoeba cyst. The composition comprising the substantially homogenous population or culture can further comprise, or alternatively consist essentially of, or yet further consist of a carrier, such as buffer, media or a device, as shown in FIG. 3 . This disclosure further provides a device as shown in FIG. 3 for culture and transport of pathogens.
[0011] The disclosed methods have utility in: transporting pathogens from military field hospitals and clinics to the laboratory; transporting pathogens from global satellite laboratories to clinical laboratories; long term storage of pathogens; enriching contaminated patient samples for pathogens of interest; bio-surveillance and detection efforts.
[0012] Further provided is a culture transport device comprising a housing having a first compartment and a second compartment, the first and second compartments being separated by a permeable membrane, wherein the second compartment comprises a removable cap comprising a sampling elongated member and a locking device, wherein when the locking device is activated, the permeable membrane is ruptured by the elongated member. In one aspect, the housing of the device is comprised of an impermeable temperature and pressure tolerant material such as polypropylene.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 illustrates growth in B. mallei strains in amoeba trophozoites. Time points were taken daily and reflect the means and standard deviations of triplicate assays. All experiments were conducted at least 3 times. % Survival=cfu at Tx/cfu at TOX100.
[0014] FIG. 2 illustrates survival of a cyclically passaged population of B. pseudomallei in human primary monocytes. The population was grown in amoeba cysts for 21 days, harvested then grown in lab media for 24 hours before being used to infect fresh amoeba again. At each passage an aliquot of the passaged population was used to infect human monocytes in parallel to lab-grown bacteria and freshly harvested amoeba-grown bacteria. Histograms and error bars represent the means and standard deviations of assays done in triplicate. Asterisks indicate the only statistically significant differences between samples.
[0015] FIG. 3 depicts a device of this disclosure that can be utilized for the safe culturing and transport of the amoeba cysts.
DETAILED DESCRIPTION
Definitions
[0016] The practice of the present invention will employ, unless otherwise indicated, conventional techniques of tissue culture, immunology, molecular biology, microbiology, cell biology and recombinant DNA, which are within the skill of the art. See, e.g., Sambrook, Fritsch and Maniatis (1989) Molecular Cloning: A Laboratory Manual, 2 nd edition; F. M. Ausubel, et al. eds. (1987) Current Protocols In Molecular Biology; the series Methods in Enzymology (Academic Press, Inc.): PCR 2: A Practical Approach (1995) (M. J. MacPherson, B. D. Hames and G. R. Taylor eds.); Harlow and Lane, eds. (1988) Antibodies, A Laboratory Manual; Harlow and Lane, eds. (1999) Using Antibodies, a Laboratory Manual; and R. I. Freshney, ed. (1987) Animal Cell Culture.
[0017] All numerical designations, e.g., pH, temperature, time, concentration, and molecular weight, including ranges, are approximations which are varied (+) or (−) by increments of 1.0 or 0.1, as appropriate. It is to be understood, although not always explicitly stated that all numerical designations are preceded by the term “about”. It also is to be understood, although not always explicitly stated, that the reagents described herein are merely exemplary and that equivalents of such are known in the art.
[0018] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above.
[0019] As used in the specification and claims, the singular form “a,” “an” and “the” include plural references unless the context clearly dictates otherwise.
[0020] As used herein, the term “comprising” is intended to mean that the compositions and methods include the recited elements, but do not exclude others. “Consisting essentially of” when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination when used for the intended purpose. Thus, a composition consisting essentially of the elements as defined herein would not exclude trace contaminants or inert carriers. “Consisting of” shall mean excluding more than trace elements of other ingredients and substantial method steps. Embodiments defined by each of these transition terms are within the scope of this invention.
[0021] The term “isolated” means separated from constituents, cellular and otherwise, in which the cell, tissue, polynucleotide, peptide, polypeptide, protein, antibody or fragment(s) thereof, which are normally associated in nature. For example, an isolated polynucleotide is separated from the 3′ and 5′ contiguous nucleotides with which it is normally associated in its native or natural environment, e.g., on the chromosome. As is apparent to those of skill in the art, a non-naturally occurring polynucleotide, peptide, polypeptide, protein, antibody or fragment(s) thereof, does not require “isolation” to distinguish it from its naturally occurring counterpart. An isolated cell is a cell that is separated form tissue or cells of dissimilar phenotype or genotype.
[0022] The term “propagate” means to grow or alter the phenotype of a cell or population of cells. The term “growing” refers to the proliferation of cells in the presence of supporting media, nutrients, growth factors, support cells, or any chemical or biological compound necessary for obtaining the desired number of cells or cell type. In one embodiment, the growing of cells results in the regeneration of tissue.
[0023] The terms “culturing” or “incubating” refer to the in vitro propagation of cells or organisms on or in media of various kinds. It is understood that the descendants of a cell grown in culture may not be completely identical (i.e., morphologically, genetically, or phenotypically) to the parent cell. By “expanded” is meant any proliferation or division of cells.
[0024] A “composition” is also intended to encompass a combination of a compound or composition and another carrier, e.g., a solid support such as a culture plate or biocompatible scaffold, inert (for example, a culture plate) or active, such as an adjuvant, diluent, binder, stabilizer, buffers, salts, lipophilic solvents, preservative, adjuvant or the like. Carriers also include pharmaceutical excipients and additives proteins, peptides, amino acids, lipids, and carbohydrates (e.g., sugars, including monosaccharides, di-, tri-, tetra-, and oligosaccharides; derivatized sugars such as alditols, aldonic acids, esterified sugars and the like; and polysaccharides or sugar polymers), which can be present singly or in combination, comprising alone or in combination 1-99.99% by weight or volume. Exemplary protein excipients include serum albumin such as human serum albumin (HSA), recombinant human albumin (rHA), gelatin, casein, and the like. Representative amino acid/antibody components, which can also function in a buffering capacity, include alanine, glycine, arginine, betaine, histidine, glutamic acid, aspartic acid, cysteine, lysine, leucine, isoleucine, valine, methionine, phenylalanine, aspartame, and the like. Carbohydrate excipients are also intended within the scope of this invention, examples of which include but are not limited to monosaccharides such as fructose, maltose, galactose, glucose, D-mannose, sorbose, and the like; disaccharides, such as lactose, sucrose, trehalose, cellobiose, and the like; polysaccharides, such as raffinose, melezitose, maltodextrins, dextrans, starches, and the like; and alditols, such as mannitol, xylitol, maltitol, lactitol, xylitol sorbitol (glucitol) and myoinositol.
[0025] “Substantially homogeneous” describes a population of amoeba in which more than about 50%, or alternatively more than about 60%, or alternatively more than 70%, or alternatively more than 75%, or alternatively more than 80%, or alternatively more than 85%, or alternatively more than 90%, or alternatively, more than 95%, or alternatively more than 97% of the amoeba are of the same or similar phenotype.
[0026] The term “effective amount” refers to a concentration or amount of a reagent or composition, such as a composition as described herein, cell population or other agent, that is effective for producing an intended result, including cell growth and/or differentiation in vitro or in vivo, or for the treatment of a disease or condition as described herein. It will be appreciated that the number of cells to be administered will vary depending on the specifics of the disorder to be treated, including but not limited to size or total volume/surface area to be treated, as well as proximity of the site of administration to the location of the region to be treated, among other factors familiar to the medicinal biologist.
[0027] The terms effective period (or time) and effective conditions refer to a period of time or other controllable conditions (e.g., temperature, humidity for in vitro methods), necessary or preferred for an agent or composition to achieve its intended result, e.g., the differentiation of cells to a pre-determined cell type.
[0028] The term patient or subject refers to animals, including mammals, preferably humans, who are treated with the pharmaceutical compositions or in accordance with the methods described herein. Other animals include, simians, bovines, ovines, equines, canines, felines, and murines.
[0029] The term pharmaceutically acceptable carrier (or medium), which may be used interchangeably with the term biologically compatible carrier or medium, refers to reagents, cells, compounds, materials, compositions, and/or dosage forms that are not only compatible with the cells and other agents to be administered therapeutically, but also are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other complication commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable carriers suitable for use in the present invention include liquids, semi-solid (e.g., gels) and solid materials (e.g., cell scaffolds and matrices, tubes sheets and other such materials as known in the art and described in greater detail herein). These semi-solid and solid materials may be designed to resist degradation within the body (non-biodegradable) or they may be designed to degrade within the body (biodegradable, bioerodable). A biodegradable material may further be bioresorbable or bioabsorbable, i.e., it may be dissolved and absorbed into bodily fluids (water-soluble implants are one example), or degraded and ultimately eliminated from the body, either by conversion into other materials or breakdown and elimination through natural pathways.
Methods
[0030] For the purpose of illustration only, A. castellanii , the select agent pathogen Burkholderia pseudomallei , and the emerging pathogen Acinetobacter baumannii, A. castellanii cysts can act as a natural transport system for pathogens from field locations to the laboratory at room temperature, e.g., from about 23° C. to about 45° C., or alternatively from about 23° C. to about 42° C., or about 37° C. These pathogens survive long-term in amoebae cysts and can be recovered post excystment for testing or other manipulation as desired. As shown in more detail below, Applicant has used the disclosed method to recover bacteria and confirmed phenotype to ensure no loss of viability or virulence. Non-limiting examples of bacteria for transport using the above method include, without limitation A. baumannii (Bouvet and Grimont ATCC 9955) and B. pseudomallei , (ATCC 23343).
[0031] Thus, in one aspect, Applicant provides a method for transporting a pathogen under ambient conditions e.g., from about 23° C. to about 45° C., or alternatively from about 23° C. to about 42° C., or about 37° C., comprising, or alternatively consisting essentially of, or yet further consisting of, culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite of the amoeba, causing the trophozoite to encyst, and then culturing under conditions that favor the conversion of the amoeba cyst to a trophozoite. As is apparent to those of skill in the art, a trophozite is the active feeding and motile stage of the ameboid while the cyst stage is the dormant, non-feeding or mobile stage in the life cycle.
[0032] Applicant has discovered that the conditions that favor incorporation of the pathogen into the trophozoite comprise or are enhanced by, or alternatively consist essentially of, or yet further consist of, contacting the pathogen with the amoeba in an iron rich environment. As used herein, the term “iron rich” intends an environment having, as compared to conventional media for the growth and/or maintenance of amoeba, at least 2×, or alternatively at 3×, or alternatively at least 4×, or alternatively at least 5×, or alternatively at least 6×, or alternatively at least 7×, or alternatively at least 8×, or alternatively at least 9×, or alternatively at least 10×, concentration of iron in the media, or alternatively from about 2× to 10×, or alternatively at least about 3× to 10×, or alternatively at least about 4× to 10×, or alternatively at least about 5× to 10×, or alternatively at least about 6 to 10× of an iron source in the media. Alternatively, the iron is present in an amount of at least about 0.005 M, or at least about 0.01M, or alternatively at least about 0.02M, or alternatively at least about 0.03M, or alternatively at least about 0.04M, or alternatively at least about 0.05M, or alternatively at least about 0.06M, or alternatively at least about 0.07M, or alternatively from about 0.01M to 0.07M, or alternatively from about 0.02M to about 0.06M, or alternatively from about 003M to about 0.06M, or alternatively about 0.05 M iron, e.g., 0.05M ferrous ammonium sulfate (FeAmSO 4 ).
[0033] Applicant has discovered that when the amoeba and the pathogen are cultured in conditions of iron rich environment, the amoeba quickly engulfs the pathogen. The culturing is accomplished under ambient conditions, depending on the environment of the pathogen. For example, the amoeba can be transported from a tropical location as a cyst and then converted to the active growing form (trophozoite) by adding nutrient rich media. Thus, the pathogen can be added to the amoeba under conditions that favor the growth and replication of the amoeba and the culture media is changed to nutrient rich and an iron source is added to the culture to provide the iron rich environment. When the nutrients in the culture media have been depleted, the amoeba will convert into a cyst, which is environmentally tolerant and can be easily transported. In a further aspect, antimicrobial or antibiotics can be added to remove all active pathogen in the culture just prior to or after cyst formation. As noted before, the trophozoite containing the pathogen will then encyst and can then be transported under ambient conditions. The cyst is converted back to the actively growing trophozoite form and the pathogen is released from the trophozoite by culturing the cysts under in iron and nutrient rich media. In one aspect, a solution to lyse the trophozoite, such as a 0.5% saponin solution can be used to release the pathogen from the trophozoite.
[0034] For the purpose of illustration only, Applicant has found that by culturing at least 0.5×10 6 or alternatively at least 1.0×10 6 pathogens per ml iron-rich media, the amoeba and pathogen will replicate and the amoeba will engulf the pathogen and convert to a cyst in several hours. After the cyst is converted into an amoeba trophozoite, the pathogen are released into the culture media where they can be isolated and characterized using conventional microbial techniques.
[0035] The above methods are useful to transport virus or bacteria, e.g., Legionella, Mycobacterium, Francisella, Yersinia, Coxiella, Klebsiella, Pseudomonas, Burkeholderia and Acinetobacer . In one aspect, the amoeba is selected from the group consisting of Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi . For added convenience, the entire process and transport can be accomplished in conventional modified cryopreservation vials (see FIG. 3 ).
[0036] This disclosure also provides a device or container for the safe transport and storage of pathogens or microbes using the methods as disclosed herein. As shown in FIG. 3 , the device is a multi-compartment container containing at least 2 compartments having at least one removable cap or tip. The shape of the device is not critical to the design. For example, the container can be cylindrical. The outer walls of the container (housing) are made of an impermeable material that is resistant to temperature and pressure fluctuations. Examples of materials include without limitation polypropylene or other plastic. The at least two-compartment container is separated by a liquid impermeable membrane or barrier that is permeable to pressure. One cap that is removable has contained in it an elongated swabbing device, such as a cotton swab, for sampling the pathogen or microbe. It is fitted with locking device such as a luer lock that when closed in the locked position, will push the swab containing the pathogen into the other compartment through the permeable membrane, e.g., a thin rubber, plastic or the like. At least one other compartment is configured to contain the amoeba cysts in a buffer solution and while the other is configured to contain the iron and nutrient rich medium. When needed, the cap is removed and one compartment is opened. The swab is used to collect the sample. The swab is returned to the inside of the container and it is locked using the locking device such as the luer lock, or any other two step lock, thereby forcing the swab through the membrane and allowing the nutrient rich medium to fall into the other compartment. Mixing the container will bring the amoeba cysts in the bottom compartment to contact the iron-rich medium and the sample resulting in amoeba excystment and microbial phagocytosis by amoeba trophozoites.
[0037] Using FIG. 3 as example, shown therein is a two compartment cylindrical container having a compartment ( 101 ) that contains the amoeba in buffer ( 102 ). An additional compartment ( 104 ) has at one end a removable cap ( 107 ) with a sampling device or swab ( 106 ) and iron rich media ( 108 ). The cap ( 107 ) contains a locking device ( 105 ). Separating the compartment is permeable membrane ( 103 ) that is punctured when the locking device ( 105 ) of the cap is activated allowing the iron rich media to flow from one compartment ( 104 ) into the other ( 101 ) and the pathogen and the amoeba to come in contact with each other.
Materials and Methods
Media
[0038] Rich Media: Modified Peptone-Yeast-Glucose (PYG)
[0000] Protease peptone 20 g Yeast Extract 1 g Add 900 ml of dd H 2 O. Autoclave and cool down to at least 55° C. Add the following: Sodium citrate 1 g 0.4M Magnesium Sulfate (MgSO 4 ) 10 ml 0.05M Calcium chloride (CaCl 2 ) 8 ml 0.05M Ferrous Ammonium Sulfate (FeAmSO 4 ) 10 ml (Filter sterilize, do not autoclave) 0.25M Dibasic Sodium phosphate ((Na) 2 HPO 4 ) 10 ml 0.25M Monobasic Potassium phosphate (KH 2 PO 4 ) 10 ml
Adjust pH to 6.5 exactly. Add 50 ml of 2 M glucose. Filter sterilize through a 0.22 μm filter.
[0039] High Salt Buffer
[0000] Mix the following:
[0000] Sodium citrate 1 g 0.4M Magnesium Sulfate (MgSO 4 ) 10 ml 0.05M Calcium chloride (CaCl 2 ) 8 ml 0.05M Ferrous Ammonium Sulfate (FeAmSO 4 ) 10 ml (Filter sterilize, do not autoclave) 0.25M Dibasic Sodium phosphate ((Na) 2 HPO 4 ) 10 ml 0.25M Monobasic Potassium phosphate (KH 2 PO 4 ) 10 ml
Add 950 ml of dd H 2 O. Adjust pH to 6.5 exactly. Filter sterilize through a 0.22 μm filter.
[0040] The ability of B. pseudomallei (Bp) and A. baumannii (Ab) isolates to survive in A. castellanii (AC) trophozoites and cysts can be confirmed by conducting infection and intracellular survival assays. For example, amoeba trophozoites are grown in Peptone-Yeast-Glucose medium at room temp (RT) in the dark. Amoeba are then seeded at a concentration of approximately 10 5 per ml per well in 24-well plates in PYG broth at room temperature.
[0041] Bacteria are grown overnight (o/n) in Nutrient broth (NB for both Ab and Bp) available from Difco-Invitrogen) broth at 37° C. with shaking.
[0042] The PYG medium can be removed by aspiration from the Ac plates and replaced by 1 ml of High Salt Buffer (HSB) per well and the plates incubated at 37° C. for 1 hr. 100 μl of bacterial cultures are added per amoeba well to achieve a multiplicity of infection (MOI) of 10 and then incubated for 30 min at 37° C. to allow bacterial internalization then washed 1× with HSB. Media is replaced by fresh HSB containing 100 μg/ml gentamicin and the plates incubated for 2 hours to kill extracellular bacteria. Chloroamphenicol can be used for gentamicin resistant strains.
[0043] The amoeba will is washed 1× with HSB then lysed with 0.5% Saponin release intracellular bacteria. Conventional microbiological techniques, such as plating on nutrient agar plates can be used to determine bacterial colony forming units (CFU).
[0044] To determine intracellular survival, 1 ml of fresh HSB can be added to parallel wells instead of immediate lysis at time point zero. Wells are then incubated for varying time points prior to lysis and platting.
[0000] % bacterial survival=CFU at 24 hr/CFU at time zero
[0045] Amoeba trophozoites typically encyst within 2 days after nutrient depletion. To confirm the ability of the bacteria to survive long term in amoeba cysts, plates can be incubated at temperatures ranging from 4° C. to 42° C. to demonstrate environmental tolerance. One set of wells can be lysed at weekly time points. At each time point, amoeba cysts will be centrifuged for 5 min at 1000 g. The medium will be decanted and replaced with PYG to allow excystment. Amoeba cysts are incubated at 37° C. until the first sign of turbidity or for 48 hours to allow the amoeba to excyst and the bacteria to be released into the medium. Intracellular bacteria can be recovered by platting dilutions on nutrient agar.
Genetic Stability and Storage
[0046] To confirm the suitability of A. castellanii cysts to function as a transport system for pathogens, four isolates of Burkholderia pseudomallei and one isolate of Acinetobacter baumanii were sequenced before and after they were grown in amoebae for one month, and the genomic sequences compared to identify any genetic differences. The Illumina Hi-Seq 2000 platform was used for sequencing and at least 100× genome coverage was targeted to ensure high confidence mutation analysis in the isolates. A preliminary analysis of the A. baumanii isolates and one pair of the B. pseudomallei isolates follows.
[0000]
A. baumanii
[0047] The Burrows-Wheeler Aligner (BWA) program was used to align the sequence reads from both isolates against the Reference Sequence genome for A. baumannii strain ACICU. A custom code was developed to count the nucleotides of each type that aligned to each reference genome position, plus the numbers of deletions (gaps) at each position. This produced a table of allele frequencies for each isolate at each position. The code then looked for positions where the major allele differed between the isolates. Out of 3.9 MB in the reference genome, about 29,000 such positions were identified.
[0048] Positions that had 5 or fewer reads were filtered out from either isolate mapped to them, since allele frequency estimates based on small read counts are inherently unreliable. This excluded all but the 331 locations. For each location, a chi-squared statistic and associated P-value were computed, estimating the probability that the observed difference in observed allele frequencies between the un-passaged and amoeba-passaged isolates could have occurred by chance.
[0049] Of immediate note is that, for almost all positions selected for candidate mutations, the major allele frequency ranges from 45% to 65%; there is only one site ( 1891835 ) where 100% of the reads have one allele in the un-passaged isolate and a different allele for most of the reads in the passaged isolate. Sorting the table in descending order of major allele frequency for the un-passaged isolate, reveals that the 3 positions with the highest major allele frequency (MAF) all have relatively small numbers of reads mapped to them. Any evidence for actual mutations at these sites is pretty weak.
[0050] In addition, when re-sorting the table by genome position, Applicant noted that the locations of the candidate mutations were clustered into small genome regions. The distribution of these regions suggested that they map to insertion (IS) elements, or other repeated sequences. On examining the GenBank annotations for the A. baumannii ACICU genome, positions 262878-264180 was annotated as a hypothetical protein. However, when performing BLAST queries of this protein sequence against GenBank data, it was found that analogous proteins are annotated as antibiotic resistance islands, genomic resistance islands and transposons. These data suggest that A. baumanii reads mapping to this region are hitting a transposon with an imperfect copy elsewhere in the genome, i.e., BWA could be mapping them arbitrarily to either copy, giving the appearance of a mixed population.
[0051] Another region, 1109338-1165207, is somewhat larger (56 kB), and maps to multiple genes, so it's less obvious that there it is a repeat sequence. However, generation of a dotplot from performing BLAST queries of the ACICU genome against itself indicates a string of duplicated sequences; one set of copies in the region 1150000-1155000, the other from 2900000-2935000 (which includes the other large stretch of candidate mutations). These data suggest a similar pattern, where reads are mapped arbitrarily to the different copies and thus appear to indicate mutations, when actually they're just reflecting the variation between paralogs.
[0052] In summary, our initial analyses suggest that all the candidate mutations observed are resulting either from either noise variation when the number of mapped reads is small, or from variation between paralogs within the reference genome. So at least for this pair of isolates, there is no evidence for mutations resulting from growth in amoebae.
[0000]
B. pseudomallei
[0053] Similar to the approach used for A. baumannii isolates, BWA was used to align the sequence reads from the two isolates of B. pseudomallei strain PHLS17—one passaged in amoeba and the other grown in standard lab broth—against the Reference Sequence genome for B. pseudomallei strain K96243. A custom program was created to tabulate, at each position in the two K96243 chromosomes, the allele frequencies for each nucleotide and the frequency of deletions (gaps). About 29,000 positions (out of 7.1 million) for which the major allele differed between the two sets of reads. However, these differences are unlikely to represent actual mutations. Since B. pseudomallei are characterized by extensive recombination and duplication of genome regions, many sequence reads (about 35,000 in this case) align to multiple locations in the genome. Subsequent mutations in the duplicated regions in distant ancestors of the current PHLS17 strain cause slight variations between the multiple genome sequences aligned to a sequence read. Similar to our observations on the analysis of the A. baumannii sequences, these variations between paralogous regions can masquerade as mutations between isolates. B. pseudomallei genomes have vastly more internal duplication than A. baumannii genomes, so the number of potential false mutations is much larger.
Long Term Stability
[0054]
F. tularensis
[0055] In contrast to B. pseudomallei and A. baumanii, F. tularensis is a very fastidious organism that is often hard to grow in the laboratory. The Schu S4 strain, which is the typical type A strain used in research, was used as well as three clinical strains isolated from human Tularemia outbreaks in Utah and minimally manipulated in the laboratory. One of these strains (80700069) has been identified as type A2, while the rest are all type A1 strains. Previous work has shown that all these strains are capable of entry and replication within amoeba (El-Etr, S. H. et. al. (2009) Appl Environ Microbiol. 75:7488-7500). In addition, with the exception of strain 80700069, all the strains cause the rapid encystment of A. castellanii.
[0056] All clinical strains are shown to survive intracellularly in amoeba cysts up to six weeks post infection (Table 1) at temperatures ranging from 26 to 42° C. The Schu S4 strain was not recovered from amoeba cysts after three weeks post infection. This observation may be explained by the fact that the Schu S4 strain has been propagated under laboratory conditions for almost 70 years since its initial isolation from a clinical case and that some loss of virulence is to be expected.
[0000]
TABLE 1
Recovery of F. tularensis type A strains from amoeba cysts at weekly
intervals after initial infection. NG denotes no growth in experimental
wells after addition of rich medium, plus signs indicate successful
bacterial recovery and Al or A2 indicates strain type.
Strain
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
SchuS4 (A1)
+
+
+
NC,
NC,
NG
70102163(A1)
+
+
+
+
+
+
80700069 (A2)
+
+
+
+
+
+
80502541 (Al)
+
+
+
+
+
+
B. mallei
[0057] Though not as fastidious as F. tularensis, B. mallei strains are not as environmentally tolerant as B. pseudomallei and for a long time the organisms were thought to have a strict requirement for a mammalian host. Recent data from Australia however indicate the organism may survive long enough in the environment to infect incidental hosts.
[0058] Two strains of B. mallei from the ATCC were used to investigate the ability to survive and replicate in amoeba (ATCC (15310 and 10399) and two clinical strains isolated from India and Turkey. Of these strains, only the Turkish strain (NCTC 10260) is known to be isolated from an infected human, the Indian strain having been isolated from a mule. The rest of the strains have been isolated from horses, the natural hosts of B. mallei.
[0059] The data indicate that all the B. mallei strains we tested can survive and replicate well in amoeba which has never been reported before.
[0060] Long-term growth experiments examining the ability of B. mallei strains to survive in amoeba cysts indicate that all the strains tested are able to survive for 3 weeks post infection at temperatures ranging from 26 to 42° C. (Table 2). Although clinical strains were recovered up to six weeks post infection, recovery of the ATCC strains after three weeks was inconsistent, especially at 42° C. which may again be explained by loss of virulence since both strains were originally isolated more than 50 years ago.
[0000]
TABLE 2
Recovery of B. mallei strains from amoeba cysts at weekly
intervals after initial infection NG denotes no growth
in experimental wells after addition of rich medium, plus
signs indicate successful bacterial recovery.
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
ATCC 15310
+
+
+
NG
NG
NG
ATCC 10399
+
+
+
NG
NG
NG
NCTC 10260
+
+
+
+
+
+
CDC 85
+
+
+
+
+
+
[0061] On a final note, even though both F. tularensis and B. mallei clinical strains can survive in amoeba cysts up to six weeks, recovery of the bacterial isolates after transport has yet to be done at 37° C. in the laboratory. Attempts to recover both pathogens at higher temperatures were not successful, possibly due to the sensitivity of both organisms to high temperatures when they are not protected inside amoebae cysts.
Sampling and Transport of Skin Flora
[0062] Experiments were performed with A. baumanii and B. pseudomallei in presence of human skin flora. Sterile cotton swabs were wetted with HSB and used to collect skin flora from the forearms of healthy adult volunteers. The collected bacteria were used to inoculate 1 ml of HSB and the samples were randomized then numerically labeled per IRB requirements. An aliquot of the buffer was then plated directly on nutrient agar (to determine number of bacteria added) and the rest inoculated with dilutions of either A. baumanii or B. pseudomallei cultures and added to 10 6 amoeba trophozoites previously seeded overnight. The amoebae were then incubated for 30 days at temperatures ranging from 26 to 42° C. The dilutions of A. baumanii or B. pseudomallei cultures were also plated to determine the bacterial numbers added. After one month, rich media was added to all wells. Upon observing signs of turbidity, dilutions of the supernatants were plated to assess colony-forming units (cfu) as well as streaked for isolation to enable gram staining and bacterial identification.
[0063] Results indicate that in each experiment, Applicant was able to detect as little as 430 cfu A. baumanii (Table 3) or 177 cfu of B. pseudomallei (Table 4). This makes the multiplicity of infection <0.001 (MOI number of bacteria/number of amoeba). These results were consistent at temperatures ranging from 26 to 42° C. In addition, in almost all cases the amoebae were able to consume all the skin bacteria while preserving the pathogen. With the exception of one case (Table 4, Subject 9) negligent amounts of flora were recovered. The amoeba was therefore able to purify the sample from skin flora and enrich for the pathogen of interest. Interestingly, analysis of the colonies recovered from subject 9 , showed that more than 95% of the skin colonies recovered were Staphylococcus aureus indicating the subject was a carrier thereby giving us positive preliminary data about the ability of gram-positive pathogens to survive in amoebae cysts.
[0000]
TABLE 3
A. baumanii and bacterial skin flora recovered after incubation
in amoebae cysts for one month. “Added” represents the cfu
of A. baumanii or skin flora inoculated into amoebae cysts. “Recovered”
represents the cfu recovered after a 30-day incubation. TNTC: cfu
too numerous to count >1000 cfu.
A. baumanii
Subject 1
Subject 2
Subject 3
Subject 4
Subject 5
Subject 6
added/
added/
added/
added/
added/
added/
added/
recovered
recovered
recovered
recovered
recovered
recovered
recovered
4.3e 7 /TNTC
268/0
48/0
27/2
89/0
64/1
37/0
4.3e 6 /TNTC
268/1
48/0
27/0
89/1
64/0
37/0
4.36 5 /TNTC
268/3
48/1
27/0
89/0
64/2
37/1
4.3e 4 /TNTC
268/0
48/2
27/0
89/0
64/0
37/0
4.36 3 /TNTC
268/0
48/0
27/0
89/2
64/0
37/0
4.3e 2 /TNTC
268/0
48/0
27/0
89/0
64/0
37/0
[0000]
TABLE 4
B. pseudomallei and bacterial skin flora recovered after incubation in amoebae
cysts for one month. “Added” represents the cfu of B. pseudomallei or
skin flora inoculated into amoebae cysts. “Recovered” represents the
cfu recovered after a 30-day incubation. TNTC: cfu too numerous to count >1000 cfu.
A. baumanii
Subject 1
Subject 2
Subject 3
Subject 4
Subject 5
Subject 6
added/
added/
added/
added/
added/
added/
added/
recovered
recovered
recovered
recovered
recovered
recovered
recovered
4.3e 7 /TNTC
268/0
48/0
27/2
89/0
64/1
37/0
4.3e 6 /TNTC
268/1
48/0
27/0
89/1
64/0
37/0
4.3e 5 /TNTC
268/3
48/1
27/0
89/0
64/2
37/1
4.3e 4 /TNTC
268/0
48/2
27/0
89/0
64/0
37/0
4.3e 3 /TNTC
268/0
48/0
27/0
89/2
64/0
37/0
4.3e 2 /TNTC
268/0
48/0
27/0
89/0
64/0
37/0
B. pseudomallei
Subject 7
Subject 8
Subject 9
Subject 10
Subject 11
Subject 12
added/
added/
added/
added/
added/
added/
added/
recovered
recovered
recovered
recovered
recovered
recovered
recovered
1.77e 7 /TNTC
115/0
87/1
287/13
109/2
16/0
71/0
1.77e 6 /TNTC
115/0
87/0
287/37
109/1
16/0
71/0
1.77e 5 /TNTC
115/2
87/0
287/28
109/0
16/0
71/0
1.77e 4 /TNTC
115/1
87/1
287/32
109/2
16/1
71/1
1.77e 3 /TNTC
115/0
87/0
287/43
109/0
16/0
71/0
1.77e 2 /TNTC
115/0
87/0
287/38
109/0
16/0
71/0
Changes in Antimicrobial, Biocide Resistance and Macrophage Survival to Ensure Lack of Phenotypic and Virulence Changes During Amoebae Growth.
[0064] Applicant has shown that survival in amoebae cysts does not increase the resistance Acinetobacter baumannii and Burkholderia pseudomallei to biocides and antimicrobials. To determine whether the enhancement in the ability of B. pseudomallei to survive in macrophages is a permanent change, amoeba-grown bacteria was inoculated into nutrient broth and grown under standard laboratory conditions for 24 hr. The bacteria were then used to re-infect fresh amoeba trophozoites. This cycle was repeated four times and at the end of each cycle the passaged B. pseudomallei population was tested for macrophage survival in parallel to regular lab-grown bacteria and bacteria freshly harvested from amoeba. The results show that after each passage in the lab media the survival of amoeba-grown bacteria returned to the levels of the broth grown strain within 24 hours ( FIG. 2 ). These data suggest that the observed survival is due to gene regulation rather that to permanent mutations.
[0065] It should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification, improvement and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications, improvements and variations are considered to be within the scope of this. The materials, methods, and examples provided here are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.
[0066] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
[0067] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0068] All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety, to the same extent as if each were incorporated by reference individually. In case of conflict, the present specification, including definitions, will control.
REFERENCES
[0000]
1. Rodriguez-Zaragoza S (1994) Ecology of free-living amoebae. Crit Rev Microbiol 20: 225-241.
2. Greub G, Raoult D (2004) Microorganisms resistant to free-living amoebae. Clin Microbiol Rev 17: 413-433.
3. Cirillo J D, Falkow S, Tompkins L S (1994) Growth of Legionella pneumophila in Acanthamoeba castellanii enhances invasion. Infect Immun 62: 3254-3261.
4. Goy G, Thomas V, Rimann K, Jaton K, Prod′hom G, et al. (2007) The Neff strain of Acanthamoeba castellanii , a tool for testing the virulence of Mycobacterium kansasii . Res Microbiol 158: 393-397.
5. El-Etr S H, Margolis J J, Monack D, Robison R A, Cohen M, et al. (2009) Francisella tularensis type A strains cause the rapid encystment of Acanthamoeba castellanii and survive in amoebal cysts for three weeks postinfection. Appl Environ Microbiol 75: 7488-7500.
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This disclosure provides a method for transporting a pathogen under ambient conditions, by culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite, starving the amoeba until it encysts, then culturing under conditions that favor conversion of the amoeba back to a trophozoite. In one aspect, the conditions that favor incorporation of the pathogen into the cyst of the amoeba comprises contacting the pathogen with the amoeba in an iron rich environment. Virus and/or bacteria are pathogens that can be transported by the disclosed method. Amoeba that are useful in the disclosed methods include, without limitation Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi . The disclosed methods have utility in: transporting pathogens from military field hospitals and clinics to the laboratory; transporting pathogens from global satellite laboratories to clinical laboratories; long term storage of pathogens; enriching contaminated patient samples for pathogens of interest; biosurveillance and detection efforts.
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BACKGROUND OF THE INVENTION
In recent times an electronically controlled sewing machine has been introduced into the marketplace and is generally of the type illustrated in U.S. Pat. No. 3,872,808, issued Mar. 25, 1975. In such a machine a static read-only-memory device is provided in which is stored stitch pattern coordinates for the needle positions and fabric feed positions for a selected number of stitch patterns. Upon selection of a pattern from a pattern display on a machine, the read-only-memory is addressed and information is released in accordance with timing pulses coordinated with the mechanism of the machine which signals are converted from digital to analogue form and fed to an actuating mechanism for the needle position and the fabric feed position to reproduce the selected pattern. With such machines the number of patterns that can be selected is restricted in accordance with the capacity of the read-only-memory device and once the patterns are fed into such a memory they are locked therein. In other words, the machine does not possess the capability of reprogramming or selective programming by operator generated information.
Dynamic programming devices such as tape drives of the magnetic and punched varieties, for example, are not practical for use in sewing machines since they require relatively elaborate power supplies for their operation. Also, tape-type memories must be recorded and read sequentially, and therefore, the operator cannot select patterns at random or from different sections of the memory at will. One such device applied to a sewing machine is illustrated in Japanese Patent Publication No. 15713/70 published on June 1, 1970. However, the machine disclosed in the Japanese patent only purports to provide needle control for production of geometric patterns and is not capable of producing non-geometric patterns which require both signals for the needle and the fabric feed. Further, a machine of this type has never been successfully introduced into the market place.
One solution to the problem of providing a re-programmable memory for a sewing machine has been proposed and disclosed in U.S. Patent application Ser. No. 631,776, filed Nov. 13, 1975 by Herr et al. and assigned to the same assignee as the present application. In this referenced application, a magnetizable material is utilized for the memory which can be selectively magnetized by the operator in accordance with pattern instructions. The magnetizable memory is then read by the machine to reproduce the pattern either by mechanical means or electronic means.
GENERAL DESCRIPTION OF INVENTION
The present application provides for a static type of re-programmable memory and sewing machine combination through which digital information may be put directly into the memory by the operator and does not require an intermediate reading device to read the program from the memory and then convert the information read therefrom into digital information. In one embodiment of the present invention the re-programmable device is located remote from the sewing machine and is readily removable therefrom and the machine is capable of being operated by information from the re-programmable memory device when connected thereto or separately from a read-only-memory incorporated within the machine when the remote re-programmable memory is disconnected therefrom. A further embodiment of the invention provides for the location of the re-programmable memory device to be integral with the machine so that the operator can input a selected pattern directly into the sewing machine display panel on the front thereof. When used herein, the term programmable memory preferably refers to a storage device of the static random access memory type (RAM) capable of being programmed upon introduction of programming instructions for temporary storage of such instruction and release therefrom upon proper address and includes a random access memory which may be programmed with all desired stitch coordinates capable of being reproduced by a sewing machine and when addressed with proper code information releasing the stitch coordinate information in accordance with the address code information.
Accordingly, it is an object of the invention to provide a novel electronically controlled sewing machine having a programmable device which can be programmed by the operator to provide stitch patterns of the operator's own choosing, if desired. It is also an object of the invention to provide a remote programmable memory device for use with the sewing machine for inputing digital signals to the machine for controlling the stitch pattern instrumentalities of the machine. Other objects and advantages of the invention will be best understood upon reading the following detailed description with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings of preferred embodiments of the invention;
FIG. 1 is a perspective view of a sewing machine of the type used in the combination of the present invention with the frame thereof showing in phantom and components thereof shown in elevation,
FIG. 2 is a view of a sewing machine and remote static programmable memory with the machine shown in front plan view and the memory shown in perspective view,
FIG. 3 is a general schematic block diagram of a system for adapting a static programmable memory unit to an existing machine having electronic stitch pattern controls,
FIG. 4 is a schematic block diagram showing the components of the programmable memory device illustrated in FIG. 2 and their connection to a sewing machine actuator or control mechanism,
FIG. 5 is a table of encoded data for the production of four different stitch patterns with each stitch pattern being pictorially represented and having alongside each the bight and feed information in binary code as well as the name of each pattern,
FIG. 6 is a front plan view of a sewing machine illustrating another embodiment with a static re-programmable memory and,
FIG. 7 is a top plan view of another embodiment of a static re-programmable memory device.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawings, in FIG. 1 there is shown a sewing machine casing 10 illustrated in phantom lines which sewing machine includes a bed 12, a bracket arm 14 and a standard 16 interconnecting the bracket arm 14 with the bed 12 as illustrated. The bracket arm 14 terminates in a head portion 18 within which is supported in a conventional manner a needle bar gate 20 in which is supported for endwise reciprocation a needle bar 22 carrying at its lower end a needle 24. Endwise reciprocation is imparted to the needle. bar 22 by an arm shaft 26 which is rotated by an electric motor (not shown) and connected to the needle bar by a conventional sewing machine mechanism (not shown) such as an eccentric mechanism to convert the rotary motion of the arm shaft 26 to reciprocating motion of the needle bar 22.
An actuating arm 28 is connected to the needle bar gate 20 at pivotal connection 30 to convert reciprocating motion of the actuating arm 28 imparted by a linear motor or actuator 32 into pivotal motion of the needle bar gate 20. The linear motor 32 of the reversible type and may be of the same type as fully described in U.S. patent application Ser. No. 431,649, filed on Jan. 8, 1974, and assigned to the same assignee as the present invention. It will be seen therefore that the linear motor 32 may be used to determine the lateral position of the needle 24 as it penetrates the fabric disposed on the bed 12 to place a thread therethrough at a particular stitch position coordinate.
In order to feed the fabric across the bed 12 in the usual manner, a feed dog 34 is disposed beneath the bed and is supported by a feed bar 36. Work transporting motion is imparted to the feed dog by means of a feed drive shaft 38 driven by gears 40 which in turn are driven by a bed shaft 42 connected to the machine arm shaft 26 in timed relationship by a conventional mechanism (not shown). A cam 44 is connected to a pitman 46 through a slide block 48 which is disposed in a slot in the cam 44. The pitman 46 is also connected to a horizontal link 50 which in turn is pivotally connected to the feed bar 36 as shown. Thus for a given inclination of the cam 44, a predictable horizontal motion of the slide block will result which is transferred to the feed dog 34 by the horizontal link member 50 and the feed bar 36. The inclination of the cam 44 may be adjusted by rotation of regulator shaft 52 which is fixed to the cam 44. The regulator shaft 52 has a rock arm 54 fixed thereto at one end with the rock arm 54 having a rod 56 also connected thereto which in turn is connected to a second reversible linear motor or 58. Therefore, the linear motor 58 will be utilized to determine the feed rate of the sewing machine by determining the inclination of the cam 44.
Referring now to FIG. 3, the general schematic block diagram is shown therein for the bight and feed control of the sewing machine. The portions of the block diagram for bight and feed control are substantially similar and it will suffice to describe the feed control only with similar numerals used for similar elements in the bight circuit except with the prime thereafter. The pattern information used for generating signals to drive the linear motors 32 and 58 preferably originates in a MOSFET Large Scale Integration (LSI) integrated circuit which is physically shown in FIG. 1 at 59 as a so-called Chip and may include a ROM, the bight logic and the feed logic portion of the electronic circuitry. A pulse generator 62 is supported on the main shaft 26 and is operative to generate pulses which are counted up in the binary counter 64 (FIG. 3) and presented as address inputs to the stitch pattern ROM 66 which is encoded to produce as output therefrom five bits of bight information and five bits of feed information as indicated as the output from the feed logic 60 and the bight logic 60'. The feed information is processed in the logic block 60 and may include a latch whereby the feed information may be held for later release to the feed servo system at a time appropriate to the operation of the feed mechanism. Similarly, the bight information is processed in logic block 60' and may include a latch whereby the bight information may be held for a later release to the bight servo system at a time appropriate to the operation of the needle jogging mechanism. As mentioned above, since the servo systems for the bight and for the feed are identical except for the specific switching necessary for manual over-ride and balance control in the feed regulating system. The following description will for convenience be confined to the feed system only.
The information processed by the feed logic block 60 is presented to the digital-to-analog converter 70, which may be a commercially obtainable unit such as the type known as the MOTOROLA MC 1406 Unit. The converter 70 has an output which is a DC analog voltage representing a required feed position input. This line connects, in the automotic mode position of a switch 72, to a summing point 74 of a low level preamplifier 76 forming the first stage of a servo amplifier system. The switch 72 may comprise an FET switch. The preamplifier 76 drives a power amplifier 78 which supplies direct current of reversible polarity to the electromechanical actuator or linear motor 58, which in its broadest sense comprise a reversible motor, to position the actuator 58 in accordance with the input analog voltage from the converter 70. A feedback position sensor 82 mechanically connected to the actuator 58 provides a feedback position signal indicative of the existing output position. The input analog voltage and a feedback signal are algebraically summed at the summing point 86 to supply an error signal. The feedback signal from the position sensor 82 is also differentiated with respect to time in a differentiator 84 and the resulting rate signal is presented to the summing point 86 of the power amplifier 78 to modify the positional signal at that point. The position sensor 82 may be any device that generates an analog voltage proportional to position and may, in this embodiment, be a simple linear potentiometer connected to a stable reference voltage and functioning as a voltage divider. The differentiator 84 is preferably an operational amplifier connected to produce an output signal equal to the time rate of change of the input voltage, as is well known in this art.
While the actuators 32 and 58 may be a conventional low-inertia rotary D.C. motor, it is preferable for the purpose of the present invention that they take the form of a linear actuators in which a light-weight coil moves linearly in a constant flux field and is directly coupled to the load to be positioned. This simplifies the driving mechanical linkage and minimizes the load inertia of the system. A switch 72 shown in the automatic mode position in FIG. 3 may be operated from the automatic position to another position referred to as the manual position. In this position the analog position voltage from the converter 70 is disconnected from summing point 74 and the voltage from a potentiometer 88 is substituted therefore. Reference may be made to copending U.S. patent application Ser. No. 596,683 July 16, 1975, and assigned to the same assignee as the present application for a more complete description of the manual stitch length control system.
Referring now to the bight control system illustrated in FIG. 3, a switch 72' shown in the automatic mode position may be operated also in a manual position for connecting into the circuit a manual bight width control circuit 90. Switches 72' and 72 may comprise F.E.T. switches. In changing the switch 72' to the manual position, a potentiometer, indicated as the manual bight width control 90, is inserted into the circuit and acts as a scaling rheostat for the analog bight voltage from the converter 70' to provide any desired fraction of this voltage at the summing point 74' and so provides convenient means for narrowing or altering the pattern.
As further shown in FIG. 3, signals may be directed from a latch 92, which is set by each pulse received from the pulse generator 62, to provide an output on line 94 to the bight logic 60' and an output on line 96 to the feed logic 60. F.E.T. switches 98 may be used selectively to connect the bight logic 60' and the feed logic 60 to the output of a static programmable memory unit 100 or to the stitch pattern read-only-memory 66 of the sewing machine. Preferably the switch 98 is a ganged switch comprising the individual switches 98 shown connected to the bight logic 60' and the feed logic 60 so that the switches will be simultaneously shifted from association with the ROM 66 to association with the programmable memory unit 100. The purpose of switching from the ROM 66 to the programmable unit 100 will be more clearly described hereinafter.
The programmable memory unit 100 is therefore compatible with the use of a stitch pattern read-only-memory unit 66 in a sewing machine in which the stitch position coordinate pattern data is electrically extracted and manipulated. The combination and selective use of the two types of memory devices disclosed herein provides a convenient means whereby operator generated stitch patterns may be implemented while retaining in the machine the ability to select from a permanently stored memory those patterns which may be most frequently utilized.
As mentioned above, it is the purpose of the invention to provide a novel combination of a programmable memory with an electronic sewing machine in which the operator can select patterns for storage in a memory device which can be reproduced by sewing machine. For accomplishing this purpose a programmable memory 100 is provided for coupling to the sewing machine as through an electrical wire 102 having a plug (not shown) for connection to a socket 104 on the sewing machine. The socket 104 may include provision for actuating the switch 98 to disengage the ROM 66 and actively couple the pulse generator 62, binary counter 64 and programmable memory unit 100 to the machine. Also, electrical current may be supplied to the memory unit 100 from the machine which is connected to an alternating current source in a known manner. The programmable memory unit 100 is of the digital type and includes appropriate selector buttons on the face plate thereof illustrated as buttons, 0 and 1 for insertion of a digital code preferably in binary form, into the memory of the memory unit 100. As schematically shown in block diagram form in FIG. 4, the memory unit 100 preferably includes a selector 106 connected to a binary encoder 108 connected in turn to the memory 110 which is a random access-type memory, as described above. In accordance with the statement of the invention, above, properly encoded digital information, such as is shown in FIG. 5, may be inserted directly into the memory 110 without the necessity for the encoder 108. Alternatively, a decimal digital code may be used which will require encoding to a binary digital code acceptable by the memory 110. As further illustrated in FIG. 4, when the memory unit 100 is connected to the sewing machine it will be coupled to the bight and feed logic, diagrammatically illustrated as 112, as a decoder, which comprises both the bight and feed logic, and to a digital-to-analog converter 114 which may include the converters 70 and 70', shown in FIG. 3, and then to the amplifier circuits 116 including the preamps and power amplifiers 76, 76' and 78, 78', and finally to the reversible DC motors 32, 58, illustrated in FIG. 4 as DC motor 118. As in the description of FIG. 3 above, a pulse generator 62 is used to address the memory 110 to withdraw therefrom the appropriate stored signals.
The programmable memory unit 100 shown in FIG. 2 also includes selector switches "P" for initiating a program, previously referred to digital code buttons 0 and 1, and a load selector switch "L" which is used to load into a display (see below) the digital code for the bight or feed selected, as will be described hereinafter. Visual displays are provided on the upper part of the panel which may be LED type displays for the bight and feed codes. Also on the upper portion of the panel is an on-off switch for independently turning the programmable memory unit on or off and a button indicated as "R" for changing the polarity of an introduced signal as for when reverse feed is desired in a pattern, such as illustrated in FIG. 5 in the column headed ±.
The operation of the remote programmable memory unit 100 for selecting a pattern will be best understood in referring to both FIGS. 2 and 5. As shown in FIG. 5 a number of patterns are illustrated therein which may be provided in a pattern book or pattern cards for the operator which are reduced to their appropriate digital code for use by the operator. For example, if the operator should wish to program in a zig-zag pattern, which is the first pattern shown in FIG. 5, the operator would turn to the page of the pattern code book in which this pattern is located, make sure the memory unit 100 is turned on and push the program button P to initiate the start of a program. For the first stitch labeled stitch one, FIG. 5, for the zig-zag pattern, in order to introduce the bight code for the first portion of the stitch the operator would push the selector button marked 0 four times. Since the polarity for the field is indicated as 0, which in this case may be a plus for forward feed, the selector "R" need not be pushed. After the selection of the first bight coordinates, namely 0000, the operator would push the load button, "L," whereupon the first bight coordinates would be indicated in the official display marked bight on the panel of the unit 100. Upon pushing the load button the device would automatically be prepared to receive the next stitch information which would be the feed portion of the first stitch coordinate. At that time, the operator would then push the appropriate button, namely the 0 button and push said button four times to enter in the appropriate feed signal, namely 0000. The operator would then again push the load button whereupon the first stitch point signal would be indicated on the feed LED display. The operator would then push the program button P whereupon both the bight and feed for the first stitch coordinate would be loaded into the memory. The same sequence would be followed for stitch coordinates 2 and 3, etc., for each pattern selected until all of the stitch coordinates are inserted into the memory for the particular selected pattern. In order to then reproduce the patterns in the sewing machine the operator would push the "S" start button and upon application of voltage to the machine, as by a foot controller or the like, the appropriate stitch pattern signals would be fed from the memory unit into the logic circuit of the sewing machine which would reproduce the pattern in accordance with the description of the electronic sewing machine of above.
Referring now to FIG. 6, the programmable memory unit is illustrated therein as being integral with the frame of the sewing machine. In other words, instead of having a remote programmable memory of the type shown in FIG. 2, it is also within the scope of the invention to provide a similar programmable memory unit 100' but built into the frame of the machine so that the operator may program patterns into the machine directly on the face plate thereof. In this embodiment a switch button 120 may be provided for activating or deactivating the switch 98 to substitute the programmable memory unit 100' for the ROM 66. It should be understood, however, that it is within the scope of the invention to provide only a programmable memory without an ROM so that each pattern selected by the operator must be programmed in by the operator.
In operation, once a particular pattern is programmed into the memory units 100 or 100' and the sewing machine is activated the pattern will be continually reproduced as long as that program is in the memory unit. In order to select another pattern the operator need merely push the program button on the program memory unit 100 or 100' and insert a new pattern which will then be recorded in the memory in place of the previously selected pattern. Alternatively of course, the programmable memory unit may be disconnected or switched off whereupon patterns provided in the ROM may be utilized. The programmable memory units 100, 100' are only intended to be illustrative of one type of remote programmable memory unit which may be used in the novel combination and other known types of programmable memory units may be adapted for use in combination with the electronic sewing machine described herein. For example, a programmable memory unit of the type manufactured by The Singer Company and known as Model 1500 may be adapted for such use since it has a keyboard through which a digital code input may be fed into a random access memory bank to store the ditital code information or to address a main random access memory having previously been programmed with stitch position coordinate information.
Referring now to FIG. 7, there is shown therein another embodiment of a selector means 122 by which an operator can visually reproduce a desired pattern on the surface 124 thereof. As shown in FIG. 7, the surface 124 of the selector 122 is provided with a matrix of points 126. Each point 126 is appropriately used for designating an individual stitch position coordinate in digital output signals for the bight and for the feed. Thus referring to FIG. 7, for the stitch position 1, which is illustrated with a number 1 in a circle, point 126 at this position will indicate a digital code of 0000 for the feed and 0000 for the bight. At point 126 at stitch position 2, indicated as the number 2 in a circle, a digital code of 0010 will be indicated for the feed and 0000 for the bight. It will be seen therefore that for each pattern physically drawn or reproduced on the surface 124 of the selector 122 appropriate digital information may be selected. The bight and feed digital information is indicated horizontally and vertically alongside the selector 122 in FIG. 7 to illustrate the digital output information required for each point 126.
It will be seen from the above description that a novel combination of a programmable memory device and an electronic sewing machine is provided wherein the operator may select any number of patterns which can be put into the memory and reproduced by the sewing machine. The programmable memory may be used in combination with a read-only-memory contained within the machine and having a fixed number of patterns, or can be used separately to program the machine for all patterns. Thus, with the use of the novel combination of the present invention an operator can reproduce substantially an infinite number of patterns limited only by the capability of the sewing instrumentalities of the machine itself. While the invention has been described in this preferred embodiment, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope thereof as defined in the appended claims.
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This disclosure relates to electronically controlled sewing machines and in particular to the combination of such a machine with a re-programmable static memory with which an operator can program in input data representative of stitch position coordinates for selected patterns, which input data will be stored and decoded into input signals for initiating operation of the sewing machine stitch position actuating means to produce patterns corresponding to the operator selected pattern. The re-programmable memory can be located remote from the machine or can be built in as an integral part of the structure of the machine itself. The machine may also contain a static read-only-memory (ROM) having fixed patterns for operation of the machine with or without a re-programmable memory and includes switching means for disconnecting the read-only-memory when the re-programmable memory is connected to the machine.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the art of automobile climate control systems, and more particularly, to a system, method, and apparatus for connecting the components of the climate control system to a manifold block of a condenser via a fitting clasp having a flange.
2. Discussion of the Related Art
Automotive climate control systems are well known in the art. Automobiles typically utilize climate control systems to absorb and dissipate heat from inside a passenger cabin to the outside of the automobile. In such systems, a manifold block connects the condenser manifold to both a compressor and an expansion valve. The manifold block connects the compressor to the condenser and the condenser to an evaporator, so that refrigerant can flow between them. Refrigerant at high temperature and high pressure in vapor form flows through the pipes from the compressor to the condenser, via the condenser manifold. In the condenser, the high temperature and high pressure refrigerant in vapor form is condensed to form refrigerant in high temperature high pressure liquid form. Then, the liquid is passed through an expansion valve. The valve restricts the flow of the refrigerant, lowering the pressure of the liquid forming low pressure low temperature liquid. This liquid refrigerant is then passed through the evaporator, where heat from the passenger cabin is absorbed as the refrigerant liquid evaporates. The resulting low pressure low temperature refrigerant flows to the compressor, which pressurizes the refrigerant to form high pressure high temperature vapor, repeating the process.
In such systems, the manifold block may be coupled to the condenser manifold via a clasp that is physically part of the manifold block. When the manifold block is coupled to the condenser manifold, the clasp is typically soldered or brazed to the condenser manifold. However, it is relatively inefficient for the fitting clasp to be a molded part of the manifold block, because if the fitting clasp is damaged or bent in any way before being soldered or coupled in any way to the condenser, the entire manifold block may be unusable. Also, the fitting clasp is susceptible to breakage after soldering, because it is only soldered/brazed to the condenser manifold at certain points. In other words, only a portion of the surface of the fitting clasp is soldered/brazed to the condenser manifold. Moreover, traditional fitting clasps are typically much shorter than the length of the manifold block and therefore may break if the manifold block is subjected to a twisting force.
FIG. 1A illustrates a manifold block 5 that has been used in the prior art. When the manifold block is initially manufactured, the side portions 10 utilized to form the claps 20 are the same length as the manifold block 5 . Sections of the side portions 10 must then be machined away to reduce the mass. During machining, the excess portions 15 are cut away. Such a method is wasteful because the excess portions typically must be scrapped.
Some systems also solder or braze the fitting clasps on the manifold block, to secure the manifold block to the manifold. In such systems, either the solder or the braze material is typically manually placed onto specific points of the clasps, and then heated up, forming a connection between the clasps and the manifold block, and between the clasps and the condenser manifold. However, such use of solder or braze material can be problematic, because solder or braze material in ring or paste form, is typically placed on the manifold block and the condenser manifold, or the clasps before being heated. Such solder/braze material may be knocked off before heating, or an operator may simply forget to include them. Consequently, the bond between the clasps and the manifold block, or between the clasp and the condenser, is weakened. Furthermore, parts are susceptible to movement during soldering or brazing, leading to higher defect rates.
Fitting clasps having flat top and bottom surfaces have been used by systems in the art. When such fitting clasps are placed between the condenser manifold and the manifold block, the refrigerant typically flows through an aperture on at least one of the fitting clasps. However, since the fitting clasp is flat, if the entire top and bottom are not fully bonded with each of the condenser manifold and the manifold block via braze material or solder, there is a possibility that the refrigerant can leak from the un-bonded location. To minimize this problem, prior art designs utilize a “sleeve” to connect the manifold block to the condenser manifold. The sleeve is a piece of metal used to line up an output aperture of the manifold block with an aperture on the condenser manifold so that refrigerant can flow between the condenser manifold and the manifold block. The sleeve is physically separate piece from the manifold block and the condenser manifold. However, it is inefficient to use such a sleeve because the sleeve is typically soldered or brazed onto the manifold block and the condenser manifold. As discussed above, the use of such solder or braze can be problematic.
Some systems in the prior art also utilize a condenser having a receiver tank. The receiver tank is utilized to hold excess refrigerant flowing out of the condenser. The receiver tank is typically located between the condenser and an expansion valve. The receiver tank can be coupled to the condenser manifold via brackets having an aperture to allow the refrigerant to flow between the condenser manifold and the receiver tank. However, such clasps are often connected via solder to the condenser manifold and the receiver tank. Also, a separate “sleeve” piece is used to line up a hole in the bracket with each of the condenser manifold and the receiver tanks. Consequently, the brackets have deficiencies similar to those of the fitting clasps used to couple manifold blocks to condenser manifolds.
The prior art is therefore deficient because solder is used to couple (a) a fitting clasp to a manifold block and a condenser manifold, and (b) brackets to a receiver tank and a condenser manifold. Also, refrigerant may leak when flowing between (a) the manifold block and the condenser manifold, and (b) the receiver tank and the condenser manifold because a separate “sleeve” piece is used to line up an aperture in the bracket or fitting clasps with the respective aperture on the condenser manifold and the bracket and fitting clasp.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a manifold block 5 that has been used in the prior art;
FIG. 1B shows a general overview of a manifold block coupled to a condenser of an automotive climate control system according to an embodiment of the present invention;
FIG. 2 illustrates a close-up view of the manifold block coupled to a condenser manifold according to an embodiment of the present invention;
FIG. 3 illustrates an exploded close-up view of the manifold block, the fitting clasps, the condenser manifold and a pipe connected to the manifold block according to an embodiment of the present invention;
FIG. 4 illustrates a close-up view of top and bottom fitting clasps according to an embodiment of the present invention; and
FIG. 5 illustrates the process by which the fitting clasp is coupled to the condenser manifold and the manifold block according to an embodiment of the present invention;
FIG. 6 illustrates a manifold block having curved legs coupled to a condenser manifold according to an embodiment of the invention;
FIG. 7A illustrates an overview of a condenser coupled to a receiver tank utilized to hold excess refrigerant according to an embodiment of the invention;
FIG. 7B illustrates an overview of a receiver tank utilized to hold excess refrigerant that is mounted directly onto a condenser according to an embodiment of the invention;
FIG. 7C illustrates an overview of a receiver tank utilized to hold excess refrigerant that is mounted directly onto the side of the condenser facing away from the compressor and the expansion valve according to an embodiment of the invention;
FIG. 8 illustrates a cut-away view of a receiver tank coupled to a condenser manifold according to an embodiment of the invention; and
FIG. 9 illustrates a bracket to couple a receiver tank to a condenser manifold according to an embodiment of the invention of the invention.
DETAILED DESCRIPTION
According to an embodiment of the present invention, fitting clasps couple a manifold block to a condenser manifold. The fitting clasps are coupled to both the manifold block and the condenser manifold by an aluminum clad material having a melting temperature below that of the material forming the manifold block, the fitting clasps, and the condenser manifold. The fitting clasps are made from aluminum clad material, and are then placed in between the manifold block and the condenser manifold. Other embodiments may utilized a copper braze material instead of an aluminum clad material. The entire device is heated to a temperature where the clad material on the outer surface of the fitting claps melts, but the material forming the manifold block, the base material of the fitting clasps, and the condenser manifold does not. After the clad material melts, the entire device is allowed to cool. As the clad material cools, a strong bond is formed, making a sturdy connection between the manifold block, the fitting clasps, and the condenser manifold. Such an embodiment is suitable for use within an automotive climate control system of an automobile, for example.
FIG. 1B shows a general overview of a manifold block 105 coupled to a condenser 100 , or a heat exchanger, of a climate control system according to an embodiment of the present invention. In the embodiment, the automotive climate control system may serve to remove excess heat from inside the passenger cabin of an automobile. A refrigerant, such as Freon, may flow through pipes or tubes of an evaporator, located inside the passenger cabin. As the refrigerant in liquid form flows through the evaporator, it absorbs heat from the passenger cabin as it evaporates into vapor form. A compressor serves to compress the resulting refrigerant to a high temperature, high pressure form. The resulting high pressure, high temperature refrigerant vapor reaches an inlet aperture 115 of the manifold block 105 . Refrigerant vapor flowing through the inlet aperture 115 enters a condenser manifold 110 and the condenser 100 , where it is condensed into liquid form.
The condenser 100 is comprised of a plurality of tubes or pipes through which refrigerant may circulate. The tubes or pipes may be formed of a heat conductive material, such as metal. In an embodiment within an automobile, as the automobile is driven, air from outside the automobile comes in contact with the tubes or pipes of the condenser 100 , and absorbs heat from the condenser 100 pipes, effectively cooling the refrigerant contained therein. A compressor pump pumps the refrigerant between the condenser 100 and an evaporator. Once the refrigerant within the pipes of the condenser 100 has condensed back into liquid form, it is connected to an expansion valve through the outlet aperture 120 . The drop in pressure as the refrigerant passes through the expansion valves causes the refrigerant to form into a low pressure, low temperature state. The refrigerant in the low pressure, low temperature form can now be returned to the evaporator, completing the cycle.
As shown in FIG. 1B, when the refrigerant is received through the inlet aperture 115 of the manifold block 105 , it flows into the top of the condenser manifold 110 . The refrigerant travels downward through the pipes of the condenser 100 , and condensed refrigerant in the pipes near the bottom of the condenser 100 flows into manifold 110 and through an aperture 125 into a pipe 122 . The refrigerant then is pumped back into the expansion valve through the outlet aperture 120 . Although the embodiment shown in FIG. 1 has a manifold block 105 connected near the top of the condenser manifold 110 , the manifold block 105 may be connected to the bottom of the condenser manifold 110 , or in another suitable location on the condenser manifold 110 , in other embodiments. Other embodiments may also include an inlet aperture 115 located above the outlet aperture 120 on the manifold block 105 .
FIG. 2 illustrates a close-up view of the manifold block 105 connected to the condenser manifold 110 according to an embodiment of the present invention. In the embodiment, two fitting clasps 200 and 205 connect the manifold block 105 to the condenser manifold 110 . The manifold block 105 is located on top of the front vertical face of the condenser manifold 110 . A top fitting clasp 200 has a set of legs 210 that contact the front vertical face of the condenser manifold 110 and extend along the side vertical faces of the condenser manifold 110 . As explained in further detail in the discussion of FIG. 2 below, the top fitting clasp 200 has an aperture that allows refrigerant to flow to the condenser manifold 110 through the aperture in the top fitting clasp 200 , and from the inlet aperture 115 of the manifold block 105 . In the embodiment shown in FIG. 2, a bottom fitting clasp 205 is coupled to the manifold block 105 and the condenser manifold 110 at a location below the top fitting clasp 200 . The bottom fitting clasp 205 also has a plurality of legs 210 that serve to couple the manifold block 105 to the condenser manifold 110 . The manifold block 105 has a side aperture 220 , which receives liquid from the bottom of condenser manifold 110 through the aperture 125 and pipe 122 . The liquid may then flow out of the outlet aperture 120 .
The legs 210 of the top 200 and bottom 205 clasps fit tightly around the front vertical face and side vertical faces of the condenser manifold 110 and serve to prevent slippage between the manifold block 105 and the condenser manifold 110 . In other embodiments, the vertical face may not be necessary based on the application requirements. Connected to a hole 220 on the bottom side of the manifold block 105 is a pipe 122 that extends to an aperture 125 near the bottom of the condenser manifold 110 (see FIG. 1 ). The metal pipe 122 is utilized to allow refrigerant to flow from the bottom of the condenser 100 . In an embodiment, refrigerant from the compressor enters the manifold block 105 through the inlet aperture 115 . Once inside the manifold block 105 , the refrigerant flows into the condenser manifold 110 through the inlet aperture 115 and down into the condenser 100 . The refrigerant liquid then flows down to the bottom of the condenser 100 . At the bottom, the liquid refrigerant flows back up to the manifold block through the pipe 122 at the aperture 125 . The pipe 122 may be formed of metal, or of any other suitable material.
The outlet aperture 120 allows refrigerant to flow from the condenser 100 to the expansion valve. When an automobile or other device utilizing this system is in operation, heated refrigerant gas may flow into the condenser 100 through the inlet aperture 115 and flow throughout the condenser 100 while outside air absorbs heat from the refrigerant. After the refrigerant has flowed through the condenser 100 , the condensed refrigerant may exit the condenser 100 through aperture 125 at the bottom of condenser manifold 110 and flow up through the pipe 122 to side aperture 220 in manifold block 105 . The liquid refrigerant may then flow out of the manifold block via outlet aperture 120 .
The top 200 and bottom 205 clasps serve to prevent slippage between the manifold block 105 and the condenser manifold 110 . Although only top 200 and bottom 205 clasps are illustrated in FIG. 2, other embodiments may use more or fewer than two clasps. In the embodiment shown in FIG. 2, each clasp has four “legs” 210 , or metal extensions extending in a direction perpendicular to front face of the clasp. In an embodiment having four legs 210 on each clasp, two legs 210 extend on each side of the clasp, with a space between each leg 210 on each side. Other embodiments may use more or less than four legs 210 .
FIG. 3 illustrates an exploded close-up view of the manifold block 105 , the top and bottom fitting clasps 200 and 205 , the condenser manifold 110 and the pipe 122 connected to the manifold block 105 according to an embodiment of the present invention. A cylindrical flange 305 extends in a direction perpendicular to the top face of the top fitting clasp 200 , in a direction away from the legs 210 as well as in the direction of the legs 210 . The cylindrical flange 305 is a protrusion on both the top and bottom surface of the top fitting clasp 200 , and it features an aperture through which refrigerant may pass when the top fitting clasp 200 is coupled to the condenser manifold 110 and the manifold block 105 . When top fitting clasp 200 is positioned beneath the manifold block 105 , the cylindrical flange 305 extends into the outlet aperture 120 . The condenser manifold 110 also has an aperture 315 near its top through which the refrigerant may flow. The refrigerant flows into the aperture 315 , through the cylindrical flange 305 , from the inlet aperture 115 . The top side of the cylindrical flange 305 extends into the manifold block 105 , and the bottom side extends into the aperture 315 of the manifold 110 , and is bonded at both locations. The top and bottom sides of the cylindrical flange 305 may be formed along the same center line and from a common material sheet (i.e., the same piece of sheet metal).
In an embodiment of the present invention, the top fitting clasp 200 , including cylindrical flange 305 , and the bottom fitting clasp 205 are all made from an aluminum clad material, and the manifold block 105 and the condenser manifold 110 are formed of an aluminum alloy having a melting temperature higher than that of the cladding portion of the aluminum clad material. In the embodiment, the melting point of the aluminum alloy may be 100 degrees higher than that of the aluminum clad material, for example. The top 200 and bottom 205 fitting clasps are placed underneath the manifold block 105 , and on top of the condenser manifold 110 . The top fitting clasp 200 is positioned so that the cylindrical flange 305 is positioned on top of the aperture 315 in the condenser manifold 110 and underneath the manifold block 105 , and the flange 305 extends into the inlet aperture 115 and into the aperture 315 of the condenser manifold 110 . The manifold block 105 , the top 200 and bottom 205 fitting clasps, and the condenser manifold 110 are then all heated to a temperature greater than the melting point of the aluminum clad material, but below that of the aluminum alloy forming the manifold block 105 , the core of the top 200 and bottom 205 fitting clasps, and the condenser manifold 110 . The aluminum clad material melts, and then the condenser manifold 110 , the top 200 and bottom 205 fitting clasps, and the manifold block 105 are allowed to cool. As they cool, the aluminum clad material solidifies and forms a strong bond between the top 200 and bottom 205 fitting clasps, the condenser manifold 110 , and the manifold block 105 , as well as between the cylindrical flange 305 and each of the inlet aperture 115 and the aperture 315 of the manifold 110 . In other embodiments, suitable materials other than aluminum or the aluminum clad material may be utilized. Copper coated steel or plain steel may be such a suitable material.
FIG. 3 also illustrates the bottom fitting clasp 205 . In the illustrated embodiment, the bottom fitting clasp 205 has four legs 210 . Other embodiments may use more or fewer than four legs 210 . The bottom fitting clasp 205 has an vertical face 300 that extends in a direction perpendicular to the front face of the bottom fitting clasp 205 , away from the legs 210 . The vertical face 300 has an aperture 310 located around its center. The pipe 122 connects to the aperture 220 through the aperture 310 on the vertical face 300 of the bottom fitting clasp 205 . When the bottom fitting clasp 205 is correctly positioned, the vertical face 300 is bonded to the bottom face of the manifold block 105 via the clad material. When bonded, the vertical face 300 serves to prevent the manifold block 105 from rotating in an angular direction. The clad material from the vertical face 300 forms a leak-free bond with the pipe 122 at the side aperture 220 of the manifold block 105 .
When in place, each leg 210 of the top 200 and bottom 205 clasps wrap onto a side of the condenser manifold 110 . When the legs 210 have been coupled to the condenser manifold 110 , they serve to prevent the manifold block 105 from rotating when subjected to an angular force or torque. This is necessary because the metal pipe 122 extending to the bottom of the condenser manifold 110 may break or become dislodged if the manifold block 105 were to rotate in such a direction. The top fitting clasp 200 also has the cylindrical flange 305 through which refrigerant may flow when the top fitting clasp 200 is coupled to the manifold block 105 and the condenser manifold 110 .
FIG. 4 illustrates a close-up view of top 200 and bottom 205 fitting clasps according to an embodiment of the present invention. As shown in FIG. 4, the cylindrical flange 305 of the top fitting clasp 200 extends in a direction perpendicular to the face thereof, extending in a direction away from the legs 210 . The aluminum clad material is used to form the cylindrical flange 305 before the manifold block 105 is positioned on top of it. As discussed above with respect to FIG. 3, during the heating process, the aluminum clad material on the cylindrical flange 305 melts, and is later cooled, forming a strong bond with the structure of the manifold block 105 having the inlet aperture 115 .
FIG. 5 illustrates the process by which the top fitting clasp 200 is coupled to the condenser manifold 110 and the manifold block 105 according to an embodiment of the present invention. First, the top fitting clasp 200 is formed from 500 clad material. The top fitting clasp 200 may be made entirely of clad material. Alternatively, it may consist primarily of a different metal that is coated on all sides with the clad material. In a situation where the condenser manifold 110 , the manifold block 105 , and the core of the top fitting clasp 200 are all formed of an aluminum alloy, the clad material may be an aluminum clad material having a melting point one hundred degrees below that of the aluminum alloy, for example. In other embodiments, the manifold block 105 and the condenser manifold 110 may also be made from clad material. At step 505 , the top fitting clasp 200 is positioned between the manifold block 105 and the condenser manifold 110 . Next, the combination of the top fitting clasp 200 , the manifold block 105 , and the condenser manifold 110 is heated 510 to a predetermined temperature. The predetermined temperature is typically above the melting point of the clad material, but below that of the aluminum alloy. Finally, the entire assembly is allowed to cool 515 . As the assembly cools, the clad material solidifies, forming a strong bond between the condenser manifold 110 and the top fitting clasp 200 , and between the manifold block 105 and the top fitting clasp 200 , as well as between the flange 305 and the outlet aperture 115 .
In other embodiments, a material other than a clad material may be utilized. For example, plain steel or copper coated steel may be utilized. A copper coated steel clasp may be coupled to a steel manifold 110 by heating in a copper brazing furnace in a manner similar to aluminum. Alternatively, if plain steel is utilized, a brazing paste may be applied onto the upper and lower surfaces of the clasp, and then the assembly may be heated in the copper brazing furnace and allowed to cool.
FIG. 6 illustrates a manifold block 105 having curved legs 605 coupled to a condenser manifold 110 according to an embodiment of the invention. As illustrated, an outlet tube 600 from the compressor may be coupled to the inlet aperture 115 of the condenser manifold 105 . The outlet tube 600 may be used to couple the compressor of the climate control system to the condenser manifold block 105 so that refrigerant can flow from the compressor through the manifold block 105 and into the condenser manifold 110 .
As illustrated, the condenser manifold 110 has a curved edge. The curved edge may have a shape similar to a circle or ellipse. The curved legs 605 of the fitting clasp 610 may curve in the same direction as the condenser manifold 110 . When placed on the condenser manifold 110 , the curved legs 605 of the fitting clasp 610 may be coupled to the condenser manifold 110 via a clad material. The fitting clasp 610 may also be coupled to the manifold block 105 via the clad material. The fitting clasp 610 may also include a flange 305 , which may be coupled to the inlet aperture 115 of the manifold block 105 via the clad material or a copper braze material.
FIG. 7A illustrates an overview of a condenser coupled to a receiver tank 700 utilized to hold excess refrigerant according to an embodiment of the invention. As shown, the condenser 100 may be coupled to the manifold block 105 . As described above in FIG. 1, the manifold block 105 may be coupled to the condenser manifold 110 . An expansion valve 710 may be coupled to the outlet aperture 120 of the manifold block 105 , and a compressor 705 may be coupled to the inlet aperture 115 of the manifold block 105 . The compressor 705 and the expansion valve 710 may also be coupled to an evaporator 715 . Refrigerant cycles through the system during the cooling process.
The condenser 100 may include a liquefied form of the refrigerant. The refrigerant may be in liquid form because high temperature and high pressure refrigerant coming from the compressor is condensed into liquid form after heat is released via the condenser 100 . The liquefied refrigerant may cycle through the pipes or tubes of the condenser 100 , and then out of the condenser 100 via the manifold block 105 , and through the expansion valve 710 . Once the liquid refrigerant passes through the expansion valve 710 , the pressure and the temperature of the liquid refrigerant drops. The pressure decrease causes the refrigerant to cool down to form a mixture containing a large amount of liquid refrigerant and a small portion of gaseous refrigerant as it enters the evaporator 715 . The mixture of liquid and gaseous refrigerant then flows through the evaporator 715 , absorbing heat from the evaporator 115 as it boils and evaporates. The gaseous refrigerant then flows to the compressor 705 , which greatly increases the pressure on the gaseous refrigerant, causing both the temperature and the pressure of the refrigerant to rise. The high temperature, high pressure gaseous refrigerant then flows back into the condenser 100 through the manifold block 105 . Heat is released from the refrigerant gas as it passes through the condenser 100 , condensing refrigerant gas into liquid form, and the process subsequently repeats itself.
The embodiment shown in FIG. 7A includes a receiver tank 700 . The receiver tank 700 may be coupled to the condenser manifold 110 of the condenser 100 . The receiver tank has a function of accumulating excess refrigerant in the condenser 100 .
FIG. 7B illustrates an overview of a receiver tank 700 utilized to hold excess refrigerant that is mounted directly onto a condenser 100 according to an embodiment of the invention. The illustrated manifold block 105 may include an inlet aperture 115 to accept refrigerant from the compressor. However, after the refrigerant cycles through the condenser 100 , it exits the condenser via an outlet in the receiver tank 700 , which is coupled to the expansion valve 710 .
FIG. 7C illustrates an overview of a receiver tank 700 utilized to hold excess refrigerant that is mounted directly onto the side of the condenser 100 facing away from the compressor 705 and the expansion valve 710 according to an embodiment of the invention. As illustrated, the receiver tank 700 is coupled to a rear manifold 720 on the back end of the condenser 100 . The condenser is shown having a plurality of pipes 725 . The refrigerant typically flows through each of the pipes in one direction. As drawn, a top manifold block 730 and a bottom manifold block 735 are utilized. The top 730 and the bottom 735 manifold block are physically separate. In other embodiments, the top 730 and the bottom 735 manifold block may be coupled together. The refrigerant enters a front manifold 745 through the top manifold block 730 . The refrigerant then flows through the top two pipes 725 to the rear manifold 720 . The refrigerant then flows down the rear manifold until it reaches the next two pipes 725 , through which it flows back to the front manifold 745 . The refrigerant then flows down toward the bottom of the front manifold until it reaches a baffle 740 , which prevents the refrigerant from flowing further down the front manifold 745 , and instead forces the refrigerant to flow back to the rear manifold 720 at the back of the condenser 100 . The baffles 740 may be included in both the front manifold 745 and the rear manifold 720 to ensure the refrigerant flows through as many of the pipes 725 as possible. The baffles 740 may be “crushed” or indented portions of the manifold. As the refrigerant flows down the rear manifold 720 , some of the refrigerant may collect in the receiver tank 700 . After the refrigerant reaches the bottom end of the front manifold 745 , it may flow out the bottom 730 manifold block and into the expansion valve 710 and on into the evaporator 715 .
FIG. 8 illustrates a cut-away view of a receiver tank 700 coupled to a condenser manifold 110 according to an embodiment of the invention. The receiver tank 700 may include one or more sets of brackets 800 to couple the receiver tank 700 to the condenser manifold 110 . Each of the brackets 800 include a cylindrical flange 805 to couple the receiver tank 700 to the condenser manifold 110 . The cylindrical flange 805 may extend into each of the condenser manifold 110 and the receiver tank 700 and bond thereto via a clad material or a copper braze material. The body of the brackets 800 may also be bonded to each of the condenser manifold 110 and the receiver tank 700 via a clad material or a copper braze material.
When the receiver tank 700 is coupled to the condenser manifold 110 , refrigerant may flow between the tank 700 and the manifold 110 via apertures in the brackets 800 . Although the embodiment shown in FIG. 8 shows “3” brackets 800 , other embodiments may use more or fewer than “3” brackets 800 . Also, other embodiments may include some brackets 800 that do not have an aperture through which refrigerant may flow. For example, an alternative embodiment may include “6” brackets to couple the receiver tank 700 to the condenser manifold 110 , but only “4” of which have apertures through which refrigerant may flow.
FIG. 9 illustrates a bracket to couple a receiver tank 800 to a condenser manifold 110 according to an embodiment of the invention. The bracket 800 has a cylindrical flange 805 which may extend in directions away from its body. The bracket 800 , including the cylindrical flange 805 , may be coated with a clad material. The bracket 800 may be placed on the condenser manifold 110 , and its cylindrical flange 805 may extend into an aperture of the condenser manifold 110 . The other end of cylindrical flange 805 may extend into the receiver tank 700 . When properly positioned, the entire assembly may be heated to a temperature greater than the melting point of the clad material, and then allowed to cool. During the cooling process, the clad material forms a bond between the bracket 800 and its cylindrical flange 805 and each of the condenser manifold 110 and the reserve tank 700 . The bracket 800 may also include rivet holes 900 , to which a rivet be placed, so that the bracket may be more securely coupled to each of the receiver tank 700 and the condenser manifold 110 .
While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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An automobile climate control system has a coolant dispersing device to allow coolant to flow. A heat exchanger cools the coolant. A manifold block allows the coolant to transfer between the coolant dispersing device and the heat exchanger. The manifold block is in communication with the heat exchanger and the coolant dispersing device. At least one separately formed clasp is fixedly mounted to the manifold block. The at least one clasp has separate legs to fixedly mount the at least one clasp to the heat exchanger. The at least one clasp has a first flange member. A first end of the first flange member is fixedly mounted to an aperture in the manifold block.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for crimping filamentary tow and more particularly to a loading arrangement for one of the forwarding rolls used to feed the tow into a stuffing box crimper.
It is well known in the art to crimp synthetic filaments that are to be processed either as broken tow or cut staple on textile processing equipment to yield yarns useful in the manufacture of fabrics. Without crimp, the tow or staple has low cohesiveness and cannot be drafted to uniform yarns on commercial textile equipment. One form of apparatus for crimping of filaments is the stuffing box crimper described in U.S. Pat. No. 2,747,233.
The crimping process usually is operated under conditions so critical that minor variations in the process can lead to crimper upsets which can result in severe product property variations such as unsatisfactory fiber properties and inadequate crimp.
A process variable that tends to give crimper upsets is the short term variations in crimper feed-rope denier resulting from merging of new ends with run-out tails of the old. Even if merges are staggered so that no two occur in parallel, the short-length increase in overall rope size can be sufficient, especially in high-speed processes, to initiate roll-clearance oscillations and out-of-control crimping during processing of several yards of rope. This problem was recognized by Stoveken and Talbott in their U.S. Pat. NO. 3,225,415, which teaches a sophisticated means to restore equilibrium operation following an upset.
SUMMARY OF THE INVENTION
In an apparatus for crimping filamentary tow including a pair of driven rolls cooperating to form a nip between the rolls through which tow passes to a crimper chamber associated with said rolls, one of said rolls being movable with respect to the other to form an adjustable width nip, the improvement comprising: a loading device having a flexible diaphragm dividing a single chamber into a front chamber and a sealed back chamber; a source of pressurized air in communication with the back chamber; a gas flow restricter connected between said source and said back chamber adjacent to said back chamber; and a linkage passing through said front chamber connected between the central portion of said diaphragm and said movable roll.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic side elevation view of a stuffer box crimper coupled to the roll loading system of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The crimper chosen for purposes of illustration includes a stuffing box 20, a pair of crimper rolls 22, 24 associated with and located above the entrance to the stuffing box for feeding a tow of filamentary material 26 into the box. The bottom of the stuffing box 20 is closed by a clapper 28 which pivots about pin 30 and is under a controlled degree of loading schematically shown as weight 32. Roll 22 is rotatably mounted on pin 23 in fixed bracket 14 and driven by means not shown while roll 24 is rotatably mounted on pin 25 in one leg of L-shaped arm 27 which is pivotally mounted for swinging movement about pin 16 at the apex of the arm 27. The other leg of arm 27 is pivotally connected to one end of rod 34 through pin 35. The other end of rod 34 is connected to the central portion of flexible diaphragm 36 of loading device 40. Thus, the rod 34 and the arm 27 and associated pins 16, 25 and 35 form a linkage between diaphragm 36 and roll 24. The loading device 40 (typically a Robotair Chamber Type 3 by Bendix-Westinghouse) comprises a housing 42 divided into a front chamber 46 and a back chamber 44 by diaphragm 36. A return spring 43 is positioned against diaphragm 36 in front chamber 46. The back chamber or pressure chamber 44 is in communication with a source of pressurized air through valve 50, pressure regulator 52, three-way valve 54 and restricter 56 located adjacent to the loading device 40 all serially connected in pipeline 58. Restricter 56 limits the flow of air to or from back chamber 44 and is in the form of a sintered metal plug which can be a Pressure Snubber No. 25S supplied by Chemiquip Products Co., Inc. Gages 57 and 59 are tied into pipeline 50 to indicate (1) pressure supplied to chamber 44 and (2) the pressure between the chamber 44 and the restricter 56, respectively.
In operation, when a short section of larger-denier tow passes between rolls 22 and 24, roll 24 is moved away from roll 22 compressing the air in chamber 44 to a higher pressure than indicated by gage 57 via the linkage of arm 27 and rod 34. Air immediately begins to flow through restricter 56 into supply line 58 but at a slow rate. When the larger-denier section of tow has passed rolls 22, 24, the immediate need is to restore roll 24 to its just-previous equilibrium position. The higher pressure developed in chamber 44 by the displacement of roll 24 tends to restrict displacement of roll 24 and most of it remains as higher-than-normal pressure acting to restore equilibrium.
The combination of a single-acting loading device 40 and a restricter 56 in the actuating air line is more effective in restoring equilibrium operation following an upset than the more complex double-acting prior art devices.
Benefits are seen with more uniform crimping with the improved crimping apparatus of this invention. For example, it has been found that two crimpers, operating side-by-side under the same conditions with the same filamentary product will deliver crimped tows of nearly identical water and textile finish content, which was not attainable with art-known crimpers. This is a substantial advantage since predictable textile processability is dependent on uniformity in both finish and water content. Crimped rope (or staple) of uniform moisture content dries more uniformly in a given process than does rope or staple with variable, or different, moisture content. In one large-scale comparison of processabilities on a Turbo Stapler, a commercial machine for draft-breaking of tow to sliver, the operator found it necessary to stop the machine an average of 1.37 times per 1000 pounds (3.03 times/Mg) while processing about 55,000 pounds (˜25,000 kg) of 470,000-denier (52,170 tex) tow that had been processed through a more complex crimper previously known in the art as 340,000-denier (37,740 tex) drawn rope (the higher denier of the tow being due to process relaxation after draw). In two tests, involving about 63,000 pounds (˜29,000 kg) and about 89,000 pounds (˜40,000 kg) of the same size tow processed through the crimper of this invention, machine stops averaged 0.74/1000 pounds (1.64/Mg) and 0.66/1000 pounds (1.45/Mg), respectively. It is well recognized in the trade that tow quality is the major factor in continuity of this operation. Reduction to about half-normal machine stops means a significant saving in labor, less fiber waste and more uniform-quality yarns.
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A tow crimping apparatus that includes a pair of advancing rolls associated with a crimping chamber is provided with a movable roll to permit controlled loading of the nip between the rolls. The controlled loading is accomplished through a pressure chamber linked to the movable roll and having a restricter in the pressure supply line to the pressure chamber.
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This is a divisional of application Ser. No. 07/525,353 filed May 18, 1990, now U.S. Pat. No. 5,311,917.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pneumatic radial tires, and more particularly to a pneumatic radial tire for use in truck and bus.
2. Related Art Statement
The conventional radial tire for truck and bus comprises a belt of at least three rubberized cord layers each containing steel cords arranged at a relatively small inclination angle with respect to the equator of the tire, cords of which layers crossing with each other, and a carcass composed of at least one rubberized cord ply containing cords arranged substantially perpendicular to the equator of the tire.
In the tire using cords as a reinforcing element for the belt, however, there is a problem that separation failure at the end of the belt (BES) results that in turn produces problems in the retreading and the safety.
The inventors have made studies with respect to the mechanism causing the above problem and confirmed that a crack is created in rubber surrounding a cord end at the end portion of the belt layer due to repetitive deformation of the belt layer during the running, particularly deformation in the face of the belt layer at the generation of side force and grows to connect the other crack created in the adjoining cord and hence causes the separation failure.
Furthermore, the inventors have made studies with respect to a relation of BES occurrence to various factors of the belt layer structure and confirmed that the bending rigidity of the steel cord itself reinforcing the belt layer and the distance between the adjoining cords largely affects the magnitude and creating time of BES.
That is, the bending rigidity of the steel cord itself affects the crack growth at the cord end, while the distance between the adjoining cords affects the easiness of connecting the cracks to each other.
In order to prevent the occurrence of such BES, the inventors have previously proposed in Japanese Utility Model laid open No. 61-206695 that the bending rigidity of the steel cord is made large by restricting a diameter of filaments constituting the steel cord to a range of 0.32-0.42 mm.
According to the above publication, the steel cord comprises a center basic structure (hereinafter referred to as core) and a coaxial layer surrounding it (hereinafter referred to as the sheath) so as to oppose the twisting direction of the filament in the core to the twisting direction of the filament in the sheath for improving the rubber penetrability. However, the filament of the core comes into contact with the filament of the sheath as a point, so that there is still room for the improvement of the resistance to fretting fatigue.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to solve the aforementioned problems and to provide a pneumatic radial tire having improved resistance to belt end separation (BES resistance) and durability and retreading property of tire.
The aforementioned fretting fatigue is considered due to the fact that since the twisting directions of the filaments in the core and sheath constituting the cord are opposite, the filaments of the core and sheath come into contact with each other as a point to locally raise the surface pressure and also the relative movement in the deformation of the cord becomes large. For this end, the inventors had assumed that the resistance to fretting fatigue could be improved by twisting the filaments in the core and sheath in the same direction. However, in case of the twisting structure in the same direction, there are problems that the rubber penetrability is poor, the core will easily come out from the sheath during running and hence brings about a risk of piercing through the tire tube to cause puncture. In order to solve these problems, it is necessary to thoroughly penetrate rubber into the core to prevent the movement of the core.
Under the above circumstances, the inventors have made further studies and found that the above object can be achieved by twisting the core and sheath of the steel cord in the same direction and simultaneously setting the total bending rigidity of filaments constituting the steel cord and the breaking load of the steel cord to given ranges, respectively, and consequently the invention has been accomplished.
According to the invention, there is the provision of a pneumatic radial tire comprising a carcass ply containing cords arranged substantially in a radial direction of the tire and a belt superimposed about said carcass ply and comprised to plural belt layers each containing steel cords arranged at a cord angle of 5°-20° with respect to an equator of the tire, characterized in that
(a) said steel cord has a two-layer structure comprising a core composed of two steel filaments and a single sheath surrounding said core and composed of 6 to 8 steel filaments, in which a twisting direction of said core is same as in a twisting direction of said sheath, and satisfies the following relationships:
0.22≦Dc≦0.44 (mm),
0.22≦Ds≦0.50 (mm),
12≦Ps≦22 (mm),
1.0≦Ps/Pc≦4.0
wherein Dc is a diameter of steel filament in the core, Pc is a twisting pitch of the core, Ds is a diameter of steel filament in the sheath and Ps is a twisting pitch of the sheath;
(b) said steel cord has a bending rigidity B of not less than 100 kg.mm 2 calculated from the following equation:
B=1.3×Σ.sub.i B.sub.i =1.3×Σ.sub.i (πD.sub.i.sup.4 /64)×20,000
wherein B i is a bending rigidity of each steel filament and D i is a diameter of each steel filament;
(c) said steel cord has a breaking load S (kgf) satisfying the following relationship:
S≧110×(0.6+D)
wherein D is a diameter (mm) of steel cord; and
(d) said steel cords are arranged so that a distance G between adjoining cords is within a range of 0.6-2.0 mm in said belt layer.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described with reference to the accompanying drawing, wherein:
FIGS. 1 to 6 are schematically sectional views of various embodiments of the steel cord as a belt reinforcement according to the invention;
FIG. 7 is a partly sectional view of a pneumatic radial tire for truck and bus; and
FIG. 8 is a schematic view illustrating an evaluation of fretting resistance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The pneumatic radial tires according to the invention will be described concretely.
According to the invention, the steel cord consists of a core comprised of 2 steel filaments and a sheath surrounding the core and comprised of 6 to 8 steel filaments from a viewpoint of cord symmetry, internal pressure holding property and prevention from coming out of the filament. When the number of steel filaments for the core is 3, a portion not penetrating rubber into the center of the core is created, and consequently when external injury is suffered in the tire, the corrosion is apt to be enlarged through propagation of water along such a portion. Furthermore, when the number of steel filaments for the core is 4 or more, it is difficult to hold the symmetry and also the distribution of stress becomes ununiform in the deformation of the cord to cause the degradation of fatigue resistance. On the other hand, when the number of steel filaments for the sheath is less than 6, if it is intended to provide the strength required for holding the internal pressure, the diameter of the steel filament should be made large, and consequently fatigue resistance is degraded. When the number of steel filaments for the sheath exceeds 8, the penetration of rubber into the inside of the cord is poor and a risk of coming out the steel filament is caused.
In order to obtain a satisfactory holding property of internal pressure, it is preferably that Dc and Ds are not less than 0.22 mm, respectively. If Dc exceeds 0.44 mm or Ds exceeds 0.50 mm, the fatigue resistance is undesirably degraded. Further, in order to obtain an effective strength, it is preferable that the twisting pitch Ps of the sheath is not less than 12 mm. If the twisting pitch exceeds 22 mm, the properties of the cord are degraded to cause the degradation of work operability. Moreover, in order to obtain effective strength while holding the tension bearing balance between core and sheath, it is favorable that a ratio of Ps to twisting pitch Pc of the core satisfies the following relationship:
1.0≦Ps/Pc≦4.0
In order to satisfactorily provide the holding property of internal pressure at a small number of steel filaments, it is preferable to enhance the tensile strength of the steel filament. For this end, it is favorable that a carbon content in the steel filament is within a range of 0.80-0.90% by weight.
As mentioned above, the steel cord according to the invention has a two-layer structure of the core and the single sheath. In this case, it is required that the twisting direction of the core is same as in the twisting direction of the sheath, whereby cord fatigue due to the fretting is prevented. Similar results are obtained by wrapping a spiral filament around the outside of the sheath of the above steel cord in a direction opposite to the twisting direction thereof.
According to the invention, the reason why the bending rigidity B of the steel cord is restricted to not less than 100 kg.mm 2 is due to the fact that when B is less than 100 kg.mm 2 , the growth of crack in the cord during the running becomes large and the effect of improving the BES resistance is not obtained.
In the steel cord according to the invention, it is required that the breaking load S satisfies a relationship represented by the following equation:
S≧110×(0.6+D)
because the sufficient internal pressure is first held when the above relationship is satisfied. When the steel cord is applied to tires for truck and bus used on bad road under heavy load, it is preferable to satisfy the following relationship:
S≧130×(0.6+D)
The above breaking load S of the cord is obtained by drawing high carbon steel having a C content of 0.80-0.90% by weight while the reduction ratio is controlled to a proper value of not less than 94%.
According to the invention, it is required that the steel cords are arranged so that a distance G between the adjoining cords is within a range of 0.6-2.0 mm in the belt layer. G is measured from the edge of one cord to the adjacent edge of the next cord. When G is less than 0.6 mm, cracks produced around adjoining cords are apt to be connected to each other and BES is easy to be caused. While, when G exceeds 2.0 mm, the rigidity of the belt decreases to degrade the steering property of the tire and the wear resistance. Moreover, G can be represented by the following equation:
G=50/T-D
wherein T is an end count of cords per 5 cm and D is a diameter (mm) of the cord.
In order to provide sufficient rubber penetrability, it is preferable to hold a gap among the steel filaments in the sheath by setting the ratio of filament diameter Ds of the sheath to filament diameter Dc of the core to the following relationships:
when the number of steel filaments for the sheath is 6, Ds/Dc≦1.65;
when the number of steel filaments for the sheath is 7, Ds/Dc≦1.15; and
when the number of steel filaments for the sheath is 8, Ds/Dc≦0.9.
An embodiment of the steel cord according to the invention is shown in FIGS. 1 to 6. FIG. 1 illustrates a steel cord having a two-layer structure of a core 1 comprising two steel filaments having the same diameter and a sheath 2 comprised of six steel filaments having a diameter larger than that in the core. FIG. 2 illustrates a steel cord having a two-layer structure of a core 1 comprising two steel filaments having the same diameter and a sheath 2 comprised of seven steel filaments having the same diameter as in the core. FIG. 3 illustrates a steel cord having a two-layer structure of a core 1 comprising two steel filaments having the same diameter and a sheath 2 comprising eight steel filaments having a diameter smaller than that in the core.
In FIGS. 4 to 6 are shown modification embodiments of FIGS. 1 to 3, in which a spiral filament 3 is wrapped around the steel cord, respectively.
The following examples are given in illustration of the invention and are not intended as limitations thereof.
There were prepared various radial tires 4 for truck and bus having a tire size of 1000R20 as shown in FIG. 7, and the rubber penetrability, fretting depth and BES resistance were evaluated with respect to these tires. In FIG. 7, numeral 5 is a bead portion, numeral 6 a sidewall portion, numeral 7a shoulder portion, numeral 8 a tread portion, numeral 9 bead wire, numeral 10 a carcass ply and numeral 11 a belt portion. In these tires, the end count of cords in the belt portion 11 was set to a strength of 5500 kg per 5 cm required for holding sufficient internal pressure.
The rubber penetrability was evaluated by removing the steel filaments of the sheath from the steel cord taken out from a new tire to leave only the core and measuring the rubber coating ratio at the surface of the core from a microphotograph as A being more than 60%, B being 35-60% and C being less than 35%. The rubber penetrability is required to be not less than the evaluation B in case of general-purpose use condition and not less than the evaluation A in case of severe use condition, while when it is not more than the evaluation C, the separation failure is apt to be caused due to the coming-out of the core and penetration of water from the injured portion.
The resistance to fretting was evaluated as follows. At first, the tire was actually run over a distance of 100,000 km. Then, the cord was taken out from the belt layer of the run tire and the coating rubber was removed off with a solvent and then steel filaments were disengaged one by one. After each steel filament was subjected to a measurement of breaking load, the fracture face of the filament was set in a microscope to obtain a microphotograph and a section paper was placed on the microphotograph so as to depict a circle along a portion causing no fretting, from which a quantity h of fretted portion 13 was measured as a unit of μm with respect to the portion 12 causing no fretting as shown in FIG. 8. Moreover, the fretting quantity was represented by an average value of 10 cords.
The resistance to fretting in Table 1 was indicated by an index that the control tire was 100. The larger the index value, the smaller the fretting quantity.
The BES resistance was evaluated by observing the inside of the tire cut after the running when the connected cracks at the belt end is inacceptable (X).
The measured results are shown in Table 1.
TABLE 1__________________________________________________________________________No. 1 2 3 4 5__________________________________________________________________________Steel cordtwisting structure 3 + 9 + 15 + 1 3 + 6 3 + 6 3 + 9 3 + 9carbon content (%) 0.72 0.72 0.82 0.82 0.82filament diameter (mm) 0.23/0.23/0.23/0.15 0.20/0.38 0.20/0.36 0.36/0.36 0.28/0.28cord diameter (mm) 1.42 1.19 1.15 1.50 1.16twisting pitch (mm) 6/12/18/5 10/18 10/18 9/18 16/16(twisting direction) (z/s) (z/s) (s/z) (s/s)bending rigidity B 96.4 165.8 134.7 257.2 94.1(kg · mm.sup.2)distance between 1.37 0.44 0.53 1.29 0.91cords (mm)breaking load (kg) 306 179 185 306 228end count (cords/5 cm) 18.0 30.7 29.7 18.0 24.1Evaluationof performancesrubber penetrability C C B A Cresistance to fretting 100 70 80 80 220BES resistance X X X ◯ XRemarks conventional conventional conventional comparative comparative example example example example example__________________________________________________________________________No. 6 7 8 9 10 11 12__________________________________________________________________________Steel cordtwisting structure 2 + 6 2 + 6 2 + 7 2 + 7 2 + 7 2 + 8 2 + 8carbon content (%) 0.82 0.82 0.82 0.82 0.82 0.82 0.82filament diameter (mm) 0.30/0.40 0.30/0.35 0.38/0.38 0.34/0.34 0.30/0.30 0.40/0.34 0.34/0.28cord diameter (mm) 1.4 1.30 1.52 1.36 1.20 1.48 1.24twisting pitch (mm) 8/16 8/16 8/16 8/16 8/16 8/16 8/16(twisting direction) (s/s) (s/s) (s/s) (s/s) (s/s) (s/s) (s/s)bending rigidity B 216.7 135.6 239.5 153.5 93.5 201.8 96.9(kg · mm.sup.2)distance between 0.75 0.54 0.93 0.73 0.53 0.96 0.60cords (mm)breaking load (kg) 237 203 269 230 190.5 268 203end count (cords/5 cm) 23.2 27.1 20.4 23.9 28.9 20.5 27.1Evaluationof performancesrubber penetrability A A A A A A Aresistance to fretting 170 170 170 180 190 170 190BES resistance ◯ X ◯ ◯ X ◯ XRemarks acceptable comparative acceptable acceptable comparative acceptable comparative example example example example example example example__________________________________________________________________________
As seen from the test results of Table 1, in the radial tires according to the invention, the rubber penetrability in the steel cord for the belt reinforcement is good and the resistance to fretting is considerably improved and the BES resistance is excellent, so that the excellent effect on the durability and the retreading property is sufficiently developed.
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A pneumatic radial tire for truck and bus comprises a carcass ply containing cords arranged substantially in a radial direction of the tire and a belt superimposed about said carcass ply and comprised of plural belt layers each containing steel cords arranged at a cord angle of 5°-20° with respect to an equator of the tire. In this case, the steel cord for the belt layer has a two-layer structure of a core comprised of two steel filaments and a single sheath comprised of 6-8 steel filaments and satisfies the particularly relationships on filament diameter, twisting pitch, bending rigidity, tensile strength and distance between adjoining cords.
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This application is a Continuation-in-Part of U.S. patent application Ser. No. 08/597,451, filed Feb. 2, 1996 entitled "MECHANICAL SEALS," now abandoned.
TECHNICAL FIELD
This invention relates to improvements in mechanical seals.
BACKGROUND TO THE INVENTION
Double mechanical seals are commonly placed at the interface between a process pump and the rotatable shaft which drives the pump. The double mechanical seal is there to avoid loss of fluid from the pump in the area where the rotatable shaft is inserted into the process pump. The rotatable shaft is usually powered by a motor.
Most double mechanical seals have a cavity defined by the sealing faces, the gland housing and the rotatable shaft through which a barrier fluid is circulated to support the correct running of both sets of faces by cooling the seal. The barrier fluid is stored in a header tank and circulated to the seal by means of inlet and outlet pipes. At present, there are two main systems for circulating the barrier fluid. The first makes use of a thermosyphon and the second a separate circulating pump.
The thermosyphon system allows for heat to be removed from the seal faces by the circulation of water. As the water is heated, it expands and thus becomes less dense than the incoming, cool water. Placing the water outlet from the seal cavity above the inlet ensures that the heated water is ducted out of the seal cavity and escapes back to the header tank. As a result, cool water is drawn in through the water inlet.
It is sometimes preferable to use oil rather than water as the barrier fluid, for example where the product being sealed is incompatible with water. Because oil does not expand sufficiently to thermosyphon when it is heated, it has to be pumped around the system. Barrier fluid also has to be pumped where large amounts of heat have to be removed from the seal, for example where the equipment is being used with explosive chemicals in which the build-up of heat could be extremely hazardous, or where a pressure differential is required to ensure that the barrier fluid is on seal faces and not the product.
In these circumstances, a second motor has been used to drive the barrier fluid pump. However, the use of a second motor can be problematical in areas where there are explosive chemicals, because the propensity of the motors and their electrical connections to cause electrical sparks can be a fire hazard. Furthermore, the use of additional pressurising pumps has historically been extremely expensive, because they are used in hazardous chemical environments and are therefore required to meet stringent safety requirements. The header tank itself, used in the pressurised system, must also be manufactured to ASME VIII standard.
It has been proposed to avoid the necessity of using a second pump and motor by incorporating fins onto that part of the seal which is attached to the rotating shaft or otherwise modifying the shape of the seal cavity to as to allow flow to be induced by the rotation of the shaft. However, it has been found that such designs are rather less effective than might have been hoped and may not perform well enough for critical hazardous chemical systems in that, whilst they create a limited flow, they do not generate enough positive pressure to effect a pressure differential across the seal faces.
SUMMARY OF THE INVENTION
The present invention avoids the need for a second motor in a barrier fluid system which provides pressure, flow and cooling when the rotatable shaft is running, and continued cooling when it is stationery. As a result the life of a double mechanical seal is lengthened by forcing contaminants or vapor from the process end of the mechanical seal, which would otherwise damage it. Heat build up in the seal is avoided thereby maintaining an appropriate running temperature. Temperature control is extremely important in maintaining the long term integrity of any rubber component present in the seal. It is also important in reducing vapor formation at the seal faces which, in the case of toxic or flammable products, can lead to atmospheric contamination or explosion.
A mechanical seal combination in accordance with the present invention comprises:
a double mechanical seal including two seals and a gland housing adapted to receive a rotatable shaft so as to define a cavity for barrier fluid between said two seals, said gland housing and the rotatable shaft;
a header vessel for storing barrier fluid and disposed above the double mechanical seal;
an inlet pipe for directing barrier fluid from the header vessel to the double mechanical seal;
an outlet pipe for recirculating barrier fluid back to the header vessel;
a separate pump for circulating the barrier fluid and located between the header vessel and the inlet;
means for coupling the rotatable shaft to the pump so as to power the pump from the rotatable shaft;
by-pass means operatively connected to the pump so as to be in a first condition, when the pump is running, in which fluid flow is directed through the pump, and in a second condition, when the pump is not running, when fluid flow by-passes the pump,
whereby the combination provides pumped fluid to the cavity when the shaft is rotating and thermosyphon supply to the cavity when the shaft is not rotating.
Preferably the combination of the invention further includes:
fluid flow resisting means, located between the outlet and the header vessel; and
further by-pass means operatively connected to the pump so as to be in a first condition, when the pump is running, in which fluid flow is directed through the fluid flow resisting means, and in a second condition, when the pump is not running, in which fluid flow by-passes the fluid flow resisting means,
whereby the combination provides increased fluid pressure in the cavity when the pump is running.
The by-pass means and the further by-pass means may be two-way valves and the fluid flow resisting means may be a needle valve. The pump is preferably a gear pump. The gear pump may be driven by a continuous flexible drive element, one end of which passes around a driven wheel which provides drive to the gear pump and the other end of which passes round a driving wheel which takes drive from the rotatable shaft. Preferably the driving and driven wheel sizes are chosen to provide at least one of a desired rate of barrier fluid flow and a desired barrier fluid pressure.
Preferably, the pressure of barrier fluid inside the header vessel is lower than that in the inlet pipe.
Preferably the inlet and outlet pipes are finned.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a diagrammatic side view of an arrangement according to the present invention although certain items are omitted for clarity.
FIG. 2 is a diagrammatic front view of the arrangement shown in FIG. 1 with further items omitted for clarity to show the pulley or sprocket and the belt or chain.
FIG. 3 is a diagrammatic front view of another arrangement according to the present invention, again with certain items omitted for clarify.
FIG. 4 is a further front view of the arrangement of FIG. 3 showing the arrangement in the alternative mode of operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the arrangement shown in FIGS. 1 and 2 differs in detail from that shown in FIGS. 3 and 4, the important components are essentially the same and will be given the same reference numbers.
Referring firstly to FIGS. 1 and 2, the arrangement includes a pump 1, bearing house 5 and motor 2 all mounted on a bed plate 12. The bed plate 12 may be metallic, eg steel, or formed from an aggregate such as concrete. Its purpose is to prevent any vibration from one part of the system being propagated to other regions. The process pump 1 is driven by the motor 2 by means of a rotatable shaft 3 connected to the motor 2 by a drive couple/clutch 4. The rotatable shaft passes through the bearing house 5 after which it connects with the pump 1.
A double mechanical seal 6 surrounds the rotatable shaft 3 where it enters the pump 1. The double seal 6 is typical in that it includes inboard and outboard seal faces and a gland housing which, together with the shaft, define an internal cavity through which barrier fluid is allowed to circulate. The barrier fluid is stored in a header vessel or tank 7 and is directed to the double seal 6 by means of a downward inlet pipe 8. The inlet pipe 8 has external copper fins 8a attached to it to increase the rate of heat loss from the barrier fluid. The barrier fluid is recirculated back to the header tank 7 by an outlet pipe 9, provided with fins 9a, which joins the top of the header tank 7. The header tank is mounted on a frame 11 which is rigidly connected to the bed plate 12.
The barrier fluid is circulated by means of a gear pump 10 attached to the inlet pipe 8 below the header vessel 7. The gear pump 10 is driven by a continuous flexible drive element 13, such as a timing belt or chain, one end of which passes around a pulley or sprocket 14 attached to the gear pump 10 and the other end of which passes around a pulley or sprocket 15 attached to the rotatable shaft 3 and positioned directly below the other pulley or sprocket 14. In this way, the rotation of the shaft 3 drives the belt or chain 13 which in turn rotates the pulley 14 thereby driving the gear pump 10.
Appropriate choice of pulley or sprocket sizes can determine the rate of barrier fluid flow and its pressure for the given fixed rotational speed of the shaft 3. The ratio of the rotational speeds of the shaft 3 to the input shaft of pump 10 is determined by the relative sizes of pulleys or sprockets 14 and 15.
Where the process pumping apparatus is installed on sites with potentially explosive chemicals it is vital that barrier fluid should not run low thereby causing the seal 6 to overheat. To guard against this possibility, the header tank 7 includes a probe 16 which controls the process pump motor 2 via an interlock. Should the probe 16 detect that the level of barrier fluid in the header tank 7 is low, the process pump motor 2 is caused to be cut off so as to prevent the seal 6 from running dry.
Referring to FIGS. 3 and 4, similar apparatus is shown to that in FIGS. 1 and 2 but omitting certain items (primarily the process pump, bearing house, gland housing and the connection between the gear pump and the shaft) but certain other items, relating to the hydraulic circuit of the apparatus, are shown in these figures.
In FIGS. 3 and 4, the hydraulic circuit associated with inlet pipe 8 includes two paths which are in parallel. A first path is from the upper part of inlet pipe 8 along conduit 18 through pump 10, along conduit 19 and back to inlet pipe 8. The other path is along inlet pipe 8 through a two-way by-pass valve 20. Pump 10 is provided with two outlets, a first outlet 21 connected to conduit 19 and a second pilot outlet 22 connected to a further conduit 23 which leads to by-pass valve 20. As indicated in the more detailed representation of by-pass 20 shown at 25 lack of oil pressure in conduit 23 is such that by-pass value 20 is in an open condition permitting oil flow through this valve along inlet pipe 8.
Referring to the hydraulic circuit associated with outlet pipe 9, there is again a by-pass valve 26 arranged in parallel with a needle valve 27 so as to provide alternative oil flow paths. By-pass valve 26 is linked to conduit 23 leading to pilot 22 and oil pressure in conduit 23 maintains valve 26 in an open condition allowing oil flow through it. The alternative oil flow route is along conduit 28 taking it through the needle valve 27. The pressure in conduit 28 is monitored by pressure gage 29.
FIG. 3 illustrates the position when the process pump is at rest. In this case the oil flow from header tank 7 is along inlet pipe 8, through open by-pass valve 20 and back to header tank 7 along outlet pipe 9 via by-pass valve 26. When the process pump is running gear pump 10 is caused to run. As a result oil pressure builds up in conduit 23 and causes by-pass valves 20 and 26 to close, preventing flow through them along inlet pipe 8 and outlet pipe 9 respectively. Consequently, oil flow associated with inlet pipe 8 passes entirely through pump 10 and on the outlet side through needle valve 27. The latter is adjusted as necessary to create a pressure in the seal cavity appropriate to the overall process pressure.
It would be appreciated that, with the process pump running, the barrier fluid supply is a pumped supply whereas, when the process pump is at rest the barrier fluid supply is due to the thermosyphon effect. Thermosyphoning allows for continued cooling to take place after the pumped fluid supply ceases.
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A mechanical seal combination includes a double mechanical seal and a barrier fluid pump system. A barrier fluid circulating pump 10 is coupled to rotatable shaft 3 so as to derive its motive power from the rotatable shaft. When the rotatable shaft is not running, a by-pass arrangement causes barrier fluids to flow between the barrier fluid header tank 7 and the seal 3, avoiding pump 10, and allowing a thermosyphon effect to be created.
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This case is a divisional of U.S. patent application Ser. No. 08/518,196, filed Sep. 7, 1995 entitled "WALL PANELS AND JOINT STRUCTURES", now abandoned.
FIELD OF THE INVENTION
This invention relates to wall panels and more particularly to insulated wall panels, apparatus for interconnecting such panels together to form walls, and to apparatus for connecting the panels to associated structures such as floors, roofs and sub-walls.
BACKGROUND OF THE INVENTION
It has long been desirable to provide a single, thermally efficient, inexpensive wall panel structure for use in erecting housing or other structures. While many attempts have been proposed, many such wall panel structures are not sufficiently strong to serve as structural building panels without extraneous support or internal studding and the like. Such studding adds components and costs and frequently presents a thermal "short circuits" or bridge lowering the insulative value or rating of the panel.
Moreover, when individual panels are interconnected or joined, they may "rack", slide or twist with respect to each other resulting in less than desirable structural stability.
In addition, it is highly desirable to provide a thermally insulative weather-resistant wall panel capable of joinder with other such panels to produce a structurally sound and durable wall structure useful in erecting and forming the walls of a house or building. In many areas of the world, in relative low income, high population areas, inexpensive, structurally sound housing is difficult to obtain. The provision of insulated panels suitable for joinder to form structurally sound, thermally efficient, inexpensive enclosures for human habitat is particularly desirable.
While insulated wall panels have been proposed, the joining of the panels together, as well as the mounting of panels to associated other structures, are subjects in need of new ideas and improvements. As noted, prior joint and joinder concepts appear to lack a sufficiently substantive nature, produce a thermal "short circuit" destroying the panel's "R" value, or both. Moreover, it has been found difficult to provide a foam core wall panel of sufficient joinder strength and rigidity to serve as a component of a structural wall of such panels.
Accordingly, it has been one objective of this invention to provide an improved wall panel and apparatus for joining similar panels to form a structural capacity wall.
Another objective of the invention has been to provide an improved apparatus for securing one or more panels to a floor.
Another objective of the invention has been to provide an improved apparatus for securing one or more panels to a roof.
Another objective of the invention has been to provide an improved wall panel and mounting system without thermal transfers through the panel due to wall mounting or panel-joining components, wall studs or the like.
It will be appreciated that in some cultures or environments, there are pre-existing structures or walls, frequently old, which form the boundary of an office or apartment. These are occasionally damp and non-uniform. For example, in certain high-population density areas around the world, large multiple tenant structures have tapered, waving or damp interior structural walls unfit to serve as a basis for a healthy home.
Accordingly, a further objective of the invention is to provide a functional wall which may easily be adapted to and mounted on existing sub-walls despite irregularities of plane, wet or leaking conditions or the like.
SUMMARY OF THE INVENTION
To these ends, a preferred embodiment of the invention includes a composite, foam core panel faced on each side with a reinforced cementitious panel, the foam edges of the composite panel being grooved peripherally inside the cementitious facing panel. Preferably, two parallel grooves are erected in each foam edge. To join composite panels edgewise, at least one flat metal strip is inserted in the groove of one panel edge and the opposed groove of an adjacent panel edge, forming a tongue enveloped by edges of both adjacent panels. Screws or other suitable fasteners are mounted through the cementitious panels, any intervening foam, and into the tongue, which thereby holds the two adjacent panels together. The tongue itself is barbed or has sharply folded edges serving as returns to dig into the foam edges of the grooves to prevent the tongue from moving after it has been inserted, thereby facilitating assembly.
Preferably, a tongue is disposed vertically extending in each adjacent groove of respective abutting panels; thus two tongues are inserted in each abutting panel edge or face.
When installing panels on a floor, a U-shaped channel with upstanding legs is secured to the floor, and the panels are lowered over the channels, the legs of the channel extending upwardly into two parallel grooves in the foam face or edge of the panel.
The top edge of the composite panel may be finished off with a downwardly disposed U-shaped channel over and extending along the top edge of the panel.
In any case, the screws into the panel joining tongue, at its ends, may also extend through the floor mounted channel and any panel cap, respectively, to provide extra rigidity to the panel wall system so created.
Where one panel is placed atop another, horizontal joining tongues disposed in the horizontal adjacent grooves are used to provide a wall of multiple panel height.
The result of such composite structures is quite spectacular; the panels so joined provide a load bearing wall, for example, not subject to "racking", i.e. where each of the panels might be twisted or racked, as a house, for example, made of such panels is blown by the wind.
Moreover, it will be appreciated that there is no through studding in the panel walls or joints between the panels. Thus, the foam constitutes a continuous barrier against the conduct of heat through the panels and is not compromised by any through structure, such as fastener-studding brackets or the like. Accordingly, a 3-inch thick foam panel with cementitious reinforced panel facings provides a wall of insulative value of about R 18, whereas a common 2×4 studded wall with foam or batting may be a maximum rating of R14.
It will be appreciated that the elongated ties, and the clips which are hereinafter described, rely on the strength of the foam within the panels and do not compromise the R value of the panel.
In one alternative form, the tie or tongue members may be provided with bent over flanges at their upper ends and the upper C-shaped channel eliminated. These upper flanges could be screwed into the bottom of a roofing panel or structure to join the vertical wall panels to a roofing structure.
In another embodiment, the invention contemplates securing such panels to an existing wall or sub-wall structure. For example, a composite foam panel may have either both sides of foam faced with a reinforced cementitious panel or only one side faced with such a panel. In any event, a groove is cut into the foam edge around the periphery of the panel, and a Z-shaped clip is placed, for example, with one leg inserted into the groove and the other leg extending rearwardly for interconnection to a wall. That leg is turned flush with the wall and secured thereto, or could be shimmed outwardly from the wall, so as to provide a planar panel wall with the shims accommodating any variation in the existing wall or sub-wall. In addition, the same Z-shaped clip could be utilized at the top edge of the panel for securing the top edge of the panel to a roofing or other support structure.
In an alternative of this embodiment, an L-shaped clip is utilized, with the short leg extending into the groove in the panel and the long leg extending rearwardly. That long leg is connected to a complimentary L-shaped clip secured to an existing wall, back-wall, or other support, for example, with the inter-engagement between the two L-shaped clips being adjustable or decided by the application of a self-threading screw, for example, and with enough play between the longer leg of the panel clip and the shorter or longer leg of the L-shaped clip on the backer wall to provide sufficient adjustment to accommodate any non-planar variations in the existing wall or sub-wall. This wall mounting is thus accomplished without any compromise in the thermal insulative properties of the panel so that there are no thermal shorts in the system.
Accordingly, the inventor provides an insulated, structural panel suitable for use in erecting structurally sound, weather-resistant walls for enclosures such as housing and building. At the same time, the invention provides an insulated panel suitable for attachment to an existing wall or sub-wall despite irregularities, wetness and the like which otherwise may not be suitably faced.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objectives and advantages will become readily apparent from the following written description of a preferred embodiment of the invention, and from the drawings, in which:
FIG. 1 is a cross-sectional plan view of two panels joined by two tongues or ties and screws or fasteners according to the invention;
FIG. 2 is cross-sectional view of one panel showing panel joinder to a floor at a lower end;
FIG. 2A is a cross-sectional view of one panel having a panel cap at an upper end;
FIG. 2B is an isometric illustration showing one alternative tongue and channel connection at a panel bottom;
FIG. 3 is an exploded view of one panel edge and two associated panel tongues;
FIG. 4 is an isometric cut-away view of two panels joined by two tongues;
FIG. 5 is a plan view showing the joinder of two panels at a 90° corner;
FIGS. 6 and 7 are cross-sectional views similar to FIG. 2 but showing the tongues having roof-attaching flanges;
FIG. 8 is a view of a double-faced panel and Z-shaped wall-mount clip with optional shim according to the invention;
FIG. 9 is a view similar to FIG. 8 but showing a single-faced panel and two L-shaped wall mount clips according to an alternative embodiment of the invention; and
FIG. 10 is a view similar to FIG. 3, but showing an alternative roof-mount clip.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in detail, a pair of abutting composite wall panels 10 are shown joined in accordance with one embodiment of the present invention in FIGS. 1 and 4. Each wall panel 10 includes a foam core 12 having reinforced cementitious facing panels 14 adhesively bonded to opposite side faces 16 of the foam core. The foam core 12, preferably 3" thick, includes a top edge 18, a bottom edge 20 and a pair of parallel side edges 22, with each peripheral edge preferably including a pair of elongated and parallel grooves 24 (see FIG. 3) extending into the edges 18, 20 and 22 (and the far edge, not shown) approximately 11/2" as will be described in more detail below. In a preferred embodiment, a pair of elongated tongues or tie members 26 are inserted vertically in opposing side edge grooves 24 of abutting wall panels 10 to join the wall panels in accordance with the present invention as will be disclosed in more detail below.
As shown most clearly in FIG. 3, each wall panel 10 preferably includes the parallel grooves 24 extending into the edges 18, 20 and 22 approximately 1/2" to 1" from the opposite side faces 16 of the foam core 12 adjacent the cementitious facing panels 14. The construction and manufacture of the reinforced cementitious facing panels 14, sold under the trademark "UTIL-A-CRETE", are described in detail in U.S. Pat. Nos. 4,203,788; 4,420,295; RE32,037; RE32,038 and RE31,921, all of which are herewith incorporated herein by reference.
As shown in FIGS. 1 and 4, the pair of tongue members 26 are inserted vertically into opposing side edge grooves 24 of abutting wail panels 10, and the wall panels are further secured by fasteners 28 (see FIG. 1) extending through the cementitious facing panels 14, intervening foam portions 30, and into the tongue members to hold the abutting wall panels together. Each tongue member 26 includes lateral edges 32 defined by sharply folded edges or returns 34 extending inwardly and rearwardly from a front face 36 of the tongue member. It will be appreciated that as the tongue members 26 are inserted into the grooves 24, the returns 34 dig into the foam core 12 adjacent the grooves to prevent the tongue members from moving after they have been inserted between abutting wall panels 10. In this way, the tongue members 26 are enveloped by the side edges 22 of abutting wall panels 10, and the fasteners 28, such as screws or the like, are inserted through the reinforced cementitious facing panels 14 on each side face 16 as described above to join the wall panels in accordance with the invention. It will be appreciated that wall panels 10 could likewise be joined one atop another, with the tongue members 26 inserted horizontally into respective opposing top and bottom edge grooves 24 of abutting wall panels to provide a wall of multiple panel height.
Referring to FIG. 2, a U-shaped footer channel 38 is shown for mounting the wall panels 10 to a floor 40. In one embodiment, each footer channel 38 includes a pair of upstanding legs or flanges 42 joined through a web 44 normal to each of the flanges. A bolt 46 or other suitable fastener is inserted through the web 44 and into the floor 40 to secure the footer channel 38 to the floor. At least one wall panel 10 is lowered onto the footer channel 38, with the upstanding flanges 42 extending into respective parallel grooves 24 formed in the bottom edge 20 of the wall panel. Fasteners 48 are preferably inserted through the cementitious facing panels 1 4, the tongue members 26 (not shown), and into the flanges 42 to secure the wall panel 10 to the footer channel 38. In an alternative embodiment shown in FIG. 2B, each tongue member 26 includes a tab 50 extending along the web 44, with each tab being secured to the web through a bolt (not shown) or other suitable means extending into the floor (not shown) through apertures 51.
Referring to FIG. 2A, a U-shaped cap panel 52 is provided in one embodiment to finish the top edge 18 of the wall panel 10. The cap panel 52 includes a pair of depending legs or flanges 54 joined through a web 56 normal to each of the flanges. The cap panel 52 is inserted on the top edge 18 of the wall panel 10, with the depending flanges 54 extending into respective grooves 24 formed in the top edge. Fasteners 48 are preferably inserted through the cementitious facing panels 14, the tongue members (not shown), and into the flanges 54 to secure the cap panel 52 to the wall panel 10.
Referring to FIG. 5, a pair of abutting wall panels 10 are shown joined at a corner 58. Each wall panel 10 includes an inclined edge 60 abutting the inclined edge of the other wall panel and further includes a pair of parallel grooves 24' extending into each inclined edge. The abutting inclined edges 60 are joined at the corner 58 through a pair of angled tongue members 62 inserted into the respective aligned grooves 24' of the abutting wall panels 10. It will be appreciated that the tongue members 62 include a longitudinal bend or angle at approximately the same angle as the corner 58. As with the tongue members 24 described above, the angled tongue members 62 have lateral edges 64 defined by sharply folded edges or returns 66 extending inwardly and rearwardly from front faces 68 of the angled tongue members. Fasteners (not shown) extend through the cementitious facing panels 14, intervening foam portions 30, and into the angled tongue members 62 to hold the abutting wall panels 10 together at the corner 58.
In a preferred embodiment as shown in FIGS. 6 and 7, each tongue member 26 includes an upper end 70 having a tab 72 bent parallel to the top edge 1 8 and extending outwardly toward the cementitious facing panel 14 for securing the tongue member 26 and associated wall panel 10 to a roof member 74. In one embodiment shown in FIG. 6, each tab 72 of respective tongue members 26 is secured to a lower surface 76 of the roof member 74 through fasteners 78. In another embodiment shown in FIG. 7, tabs 72' extend outwardly away from the wall panel 10 and are secured to an upper surface 80 of the roof member 74 through fasteners 78.
Referring now to FIG. 8, a wall panel 10 is shown being joined to a subwall or back-wall 82 in accordance with one embodiment of the present invention. A "Z-shaped" integral wall mount clip or bracket 84 is provided having a pair of legs 86 and 88 lying in two parallel, spread-apart planes and joined by an integral web 90 normal to each of the legs. The leg 86 is inserted into one of the parallel grooves 24 nearest the subwall 82 and the rearwardly extending leg 88 is joined either directly to the subwall by a fastener 92 or indirectly to the wall through an optional shim 94. It will be appreciated that the shim 94 can be provided to accommodate for non-planar irregularities in the existing subwall 82 but is not required as part of the present invention. It is understood that the leg 86 inserted into the groove 24 could include a sharply folded edge or return (not shown) to dig into the foam core adjacent the groove as described above with reference to the tongue members 26. While not shown, the bracket 84 is secured to the wall panel 10 through a suitable fastener extending through the cementitious facing panel 14, intervening foam portion 30, and into the leg 86 to hold the wall panel to the subwall 82.
In another embodiment shown in FIG. 9, a wall panel 10' is shown secured to a subwall or back-wall 82 through a pair of cooperating "L-shaped" wall mount clips or brackets 96 and 98. In this embodiment, the wall panel 10' includes a cementitious facing panel 14 secured to one of the side faces 16 of the foam core 12, with the other side face of the foam core lying adjacent the subwall 82. Wall mount clip 96 includes a pair of legs 100 and 102 normal to each other. Leg 100 is inserted into one of the parallel grooves 24 adjacent the side face 16 nearest the subwall 82, and the rearwardly extending leg 102 is joined to the complimentary "L-shaped" wall mount clip or bracket 98 secured to the existing subwall or back-wall 82. Alternatively, leg 100 is inserted into the panel groove nearest facing 14 and leg 102 extended to meet bracket 98. The complimentary bracket 98 secured to the wail 82 includes a pair of legs 104 and 106 normal to each other, with the leg 104 being joined to the wall 82 through a fastener 108 or other suitable means. Each leg 102 and 106 includes an elongated aperture 110, and a self-threading screw 112 is inserted through the apertures 110 of the legs to provide adjustable inter-engagement between the leg 102 and 106 of the wall mount clips 96 and 98. In this way, adjustment is provided for securing the wall panel 10' to a subwall 82 having non-planar irregularities. It is understood that the leg 100 inserted into the groove 24 could include a sharply folded edge or return (not shown) to dig into the foam core adjacent the groove as described above with reference to the tongue members 26. While not shown, the bracket 96 is secured to the wall panel 10' through a suitable fastener extending through the foam portion 30 and into the leg 100 to hold the wall panel to the subwall 82.
As shown in FIG. 10, an integral "Z-shaped" roof mount clip or bracket 114 is provided for securing the wall panel 10 to a roof member (not shown). The roof mount clip 114 includes a pair of legs 116 and 118 lying in two parallel, spread-apart planes and joined by an integral web 120 normal to each of the legs. The leg 116 is inserted into one of the parallel grooves 24 with the web 120 extending parallel to the top edge 18 of the wall panel 10. The upwardly extending leg 118 includes an aperture 122 for receiving a fastener (not shown) extending into a roof member secured on the top edge of the wall panel.
While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's invention.
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A wall panel and joint structure for erecting structurally sound, thermally efficient and inexpensive structures for human habitat. Each wall panel includes a foam core faced on each side with reinforced cementitious facing panels, the foam edges of the composite panel being grooved peripherally inside the cementitious facing panels. At least one metal tongue member is inserted in opposing side edge grooves of abutting wall panels, and fasteners are mounted through the cementitious facing panels, any intervening foam, and into the tongue members to hold adjacent wall panels together. U-shaped channels are provided to finish an upper edge of the wall panel and to secure a bottom edge thereof to a floor structure. Wall mount clips are provided to secure the wall panels to existing subwall structures. Flanges are provided at an upper end of the tongue members to secure roofing members to the wall panels.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation-In-Part of application Ser. No. 09/939,834, filed Aug. 28, 2001, which is a Continuation of application Ser. No. 09/938,598, filed Aug. 27, 2001, which is a Continuation of application Ser. No. 09/344,895, filed Jun. 25, 1999, now U.S. Pat. No. 6,284,550, issued Sep. 4, 2001, which is a Divisional of application Ser. No. 08/872,088, filed Jun. 10, 1997, now U.S. Pat. No. 6,040,195, issued Mar. 21, 2000, all of which disclosures are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to analytical test strip devices, and more particularly to an improved diagnostic sanitary test strip device for determining the presence, absence, and/or amount of a predetermined analyte, and having a fluid sample volume control, structure to facilitate proper orientation of the strip in a corresponding meter, and an improved agent treatment solution for facilitating end-point testing.
[0003] 2. Description of the Background Art
[0004] Analytical test strips for testing analytes in heterogeneous fluid samples are well known in the art and comprise various structures and materials. These test strips typically include single or multi-layered fibrous membrane devices which receive a heterogeneous fluid, such as whole blood, and undergo a color change in response to interaction with agents/reactants imbibed into the membrane. Prior to reaching the reactants, the fluid sample is filtered to facilitate accurate testing of the analyte. For instance, a blood sample being treated for glucose levels requires the removal of red blood cells before testing the plasma. Some test strips include additional layers that provide the requisite filtering. Other test strips attempt to filter and test a sample for a suspected analyte in a single membrane. Terminiello et al., U.S. Pat. No. 4,774,192, teaches such a dry chemistry reagent system which comprises a porous anisotropic (asymmetrical) membrane having a porosity gradient from one planar surface to the other for filtering a fluid sample and includes an indicator, flow control agent, and reagent cocktail imbibed therein for initiating the chemical reaction with the fluid sample. Anisotropic membranes, however, provide inadequate filtering and can have a tendency to produce unreliable results.
[0005] Test strip devices operate by allowing the applied heterogeneous sample to migrate to a reaction site in the membrane, where the analyte of interest in the sample reacts with the imbibed agents. The results of the reaction are usually visible through a color change in the membrane. The color change may be viewed with the naked eye and measured by a visual comparison with a color chart or reading it with a reflectance meter.
[0006] Certain problems have been noted in existing analytical test strips. Some of these problems include spillage of the sample over the edges of the strip, excessive absorption, and incomplete filtering, all of which can adversely affect test integrity. Other strips, such as those disclosed in U.S. Pat. No. 3,298,789 issued to Mast and U.S. Pat. No. 3,630,957 issued to Rey et al., require the sample to remain in contact with the reagent pad for specified time and that the blood sample be either washed or wiped off the pad. In addition, conventional strips have been known to be difficult to use in terms of the proper amount of heterogeneous fluid to place on the strip. It is also difficult to properly place and/or orient strips in a corresponding meter.
[0007] U.S. Pat. No. 5,296,192 (the “'192 patent”), issued to the inventors herein, addresses some of these shortcomings noted in the background art. The '192 patent teaches a multi-layered diagnostic test strip for receiving whole blood on which a test for a suspected analyte is performed. The multi-layered test strip device comprises two outside supports, sandwiching therebetween a spreading screen, a separating layer, and a membrane. The top support has a port for receiving the sample. The spreading screen evenly distributes the sample so that it uniformly passes into the separating layer. The separating layer removes a majority of the red blood cells from the blood sample, and the membrane removes the remaining cells. The membrane is also pretreated with reagents and conditioning agents needed for the reaction and insuring a readable, reliable color generation. The '192 patent provides a strip that may be visually read with a color comparator or a reflectance meter. The instant invention provides an improved diagnostic test strip which is built in part on some of the teachings of the '192 patent, and which has additional features for further enhancing the use and reliability of diagnostic testing. These improvements are submitted as solving the above-noted problems.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to an improved, multilayered sanitary test strip for receiving a heterogenous fluid that is tested for a suspected analyte. In the preferred embodiment, the heterogeneous fluid comprises a whole blood which is analyzed to determine the presence of analytes, such as glucose or cholesterol, to determine the presence, absence, and/or level of the analyte in the fluid. Accordingly, discussion herein is tailored to the receipt and testing of glucose analytes in a whole blood sample. As such, the suggested chemical reagents herein are specific to testing glucose in blood. It is important to note, however, that the instant invention may be used to determine the presence, absence, and/or amount of a substance in other heterogeneous fluids by modifying the chemical reagent solutions and/or concentrations employed. The diagnostic sanitary test strip may be used for other enzymes and immunoassays, such as cholesterol (HDL or LDL), ketones, theophylline, osteoporosis, H1AC, fructosamine and others. The present invention confirms the presence, absence, and/or amount of these analytes.
[0009] The multi-layered diagnostic sanitary test strip generally comprises two outside layers, between which are operative layers. Said operative layers comprise, in descending order, an optional spreading layer, a separating layer, a membrane layer. The membrane layer (or reaction membrane, or membrane) may optionally be pretreated with a reagent solution imbibed into the membrane. The multi-layered test strip taught herein improves on the test strip disclosed in U.S. Pat. No. 5,296,192, the disclosure of which is incorporated herein by reference. The instant invention is an improvement in that it provides a chemistry reagent solution and concentration that facilitates end-point testing, volume control dams to prevent spills or overflow and reduce the amount of sample needed to perform a test, and a light absorption medium which visually and functionally prevents the test strip from being tested upside down. The improved, diagnostic test strip also allows for the application of a heterogeneous fluid sample, e.g., blood, to the strip, both inside and outside the meter.
[0010] It is an object of the present invention to provide an improved multi-layered diagnostic sanitary test strip.
[0011] It is another object of the present invention to provide an improved multi-layered diagnostic sanitary test strip that prevents a heterogenous fluid sample from overflowing from the strip.
[0012] It is an additional object of the present invention to provide an improved multi-layered diagnostic sanitary test strip that is easier to use, requires a smaller amount of the heterogenous fluid sample and facilitates application of the sample on the strip when the strip is either outside or inserted in a meter.
[0013] It is a further object of the present invention to provide an improved multi-layered diagnostic sanitary test strip that facilitates proper placement and orientation of the strip in a corresponding meter.
[0014] It is yet another object of the present invention to provide an improved multi-layered diagnostic sanitary test strip that may be used in a meter that performs end-point testing.
[0015] It is yet an additional object of the present invention to provide an improved multi-layered diagnostic sanitary test strip that may be imbibed with a dry chemistry reagent solution that facilitates end-point testing.
[0016] In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of the preferred embodiment of the multi-layered diagnostic sanitary test strip of the instant invention.
[0018] FIG. 2 is a perspective view of the multi-layered diagnostic sanitary test strip prior to ultrasonically sealing the strip.
[0019] FIG. 3 a is an exploded, cross sectional view of the instant invention, taken along lines A-A of FIG. 2 .
[0020] FIG. 3 b is a cross sectional view of the instant invention, taken along lines A-A of FIG. 2 .
[0021] FIG. 4 is a cross sectional elevation view of the layers of the test strip as it appears after construction.
[0022] FIG. 5 is a cross sectional elevation view of another embodiment of the invention as it appears after construction.
[0023] FIGS. 6-10 depict the views of FIGS. 1-5 , respectively, wherein the test strip is manufactured without a spreading layer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] With reference to the drawings, FIGS. 1-10 depict preferred embodiments of the improved, multi-layered diagnostic sanitary test strip 10 of the instant invention. The test strip 10 represents an improvement over prior test strips. It embodies novel features that make the strip more sanitary, spill resistant, easier to use, accommodating of lower sample volumes, and more efficient. In a preferred use, a whole blood sample from a finger stick, or otherwise, is applied to the strip 10 to test for the presence, absence, and/or amount of a suspected analyte, e.g., glucose. It is important to note that whole blood may be tested for other analytes and that other heterogeneous fluid samples may be tested for glucose and other analytes, such as LDH/HDL cholesterol, H1AC, osteoporosis, fructosamine, etc.
[0025] The test strip 10 generally comprises an optional spreading layer (e.g., spreading screen) 20 , a separating layer 30 for filtering, and a preconditioned membrane 40 . The membrane 40 , and optionally also the separating layer 30 , can be pre treated with reagents and/or conditioning solutions, as discussed more fully herein. During use, the reagents and conditioning system filters the sample so that the analytes of interest can be more easily detected and measured without interference. For example, where blood is used, the novel system according to the invention removes red blood cells from the plasma of the sample so that red blood cells do not interfere with optical measurement.
[0026] As shown in FIG. 1 , the test strip 10 generally comprises an upper support layer 12 and a lower support layer 13 and an optional spreading layer (e.g., a spreading screen) 20 , a separating layer 30 , and a semi-porous membrane reagent layer 40 sandwiched between in descending order. FIGS. 6-10 depict the views of FIGS. 1-5 , respectively, of a test strip constructed without a spreading layer. At least one of layers 20 (when present), 30 , and 40 is pretreated with a dry chemistry reagent and conditioning solution. Preferably, the membrane 40 and separating layer 30 are pretreated with the reagent/conditioning solution. The spreading screen 20 , if present, may also pretreated. Each layer 20 , 30 , and 40 is positioned in tight, continuous contact with its adjacent layer as shown in FIGS. 4 and 5 ( FIGS. 9 and 10 in a corresponding test strip constructed without a separating layer). The support layers 12 , 13 , screen 20 , separator 30 , and membrane 40 are aligned as shown in FIGS. 2, 3 a , and 3 b ( FIGS. 7, 8 a , and 8 b without the spreading layer 20 ) and glued and ultrasonically bonded together to provide a sealed composite structure. The support strips 12 , 13 may contain a layer of adhesive on their interior surfaces to physically attach the supporting layers 12 , 13 in a way that tightly compresses the other layers 20 (when present), 30 , and 40 therebetween. The support layers 12 , 13 and operative layers 20 (when present), 30 , and 40 are further secured by ultrasonic welding. Other welding techniques may be employed, such as heat-stamping.
[0027] The support strips 12 , 13 are preferably constructed from mylar. The top and bottom support strips 12 , 13 each define an aperture or opening therethrough. These apertures or openings are oriented in vertical alignment when constructing the strip. The opening in the upper support strip 12 defines a sample receiving port 15 and the opening in the lower support strip 13 defines a reaction viewing port 18 . The spreading screen 20 , when present, abuts the interior glue surface 12 a of the upper support 12 . The separating layer 30 abuts the lower surface of spreading screen 20 and the upper surface of membrane 40 . When the spreading screen 20 is absent, the separating layer 30 abuts the lower surface of the upper support layer 12 and the upper surface of membrane 40 . The upper surface of membrane 40 abuts the lower surface of separating screen 30 and the membrane lower surface abuts the interior glue surface of the lower support strip 13 . The interior layers are oriented in vertical alignment with the sample receiving port 15 and the reaction viewing port 18 . This allows the sample received by the strip 10 to pass directly from the receiving port 15 to the viewing port 18 . This movement, however, is facilitated and assisted by the operative layers 20 (when present), 30 , and 40 of the strip and volume control structure 14 built therein. By the time the sample reaches the viewing port 18 it has undergone a color change indicative of the analyte of interest and is viewable from the viewing port 18 .
[0028] Volume control dam partitions 14 are formed in the upper support strip 12 around the sample receiving port 15 and depend downward into the strip to control the flow of the sample volume therein. The dam partitions 14 help direct the fluid sample downward toward the viewing port 18 . In addition, the dam partitions 14 resist overflow by retaining the sample and guiding the sample to provide a more sanitary diagnostic test strip 12 and decreasing the amount of sample needed to conduct a test. The strip 10 is shown with four dam partitions 14 positioned approximately 90° apart around a substantially circular sample receiving port 15 . This orientation enhances volume flow control. It should be noted, however, that the number and configuration of dam partitions 14 may vary without departing from the scope and spirit of the invention so long as fluid sample is properly retained and vertically directed. The dam partitions 14 are formed by either die-stamping or embossing the upper strip 12 when the strip layers 12 , 13 , 20 , 30 , and 40 (or 12 , 13 , 30 , and 40 ) are bound together through ultrasonic welding or stamping. The volume control dam partitions 14 provide a unique feature of the instant invention which makes the strip easier and more comfortable to use. Moreover, the likelihood of sample overflow or spilling is greatly reduced by the novel structure of the instant invention.
[0029] In reference to FIGS. 1, 4 , and 5 , two Branson detents 16 are provided for strengthening the strip and accommodating Branson securing post which may he found on a corresponding meter. The Branson post and detents 16 are designed to interlock when a strip 10 is inserted into a corresponding meter. The dam partitions 14 also serve to enhance the bond between the support strips 12 , 13 and operative layers 20 , 30 , and 40 . The bonds formed by the dam partitions 14 and Branson detent 16 result from the application of energy, preferably ultrasonic energy, applied to the upper surface of support strip 12 during assembly. The penetration of the dams 14 and detents 16 are shown by perforated lines and generally comprise deep indentations in the assembled strip 10 . The location of the Branson detents 16 correspond to location of the Branson post found in the corresponding meter. The dam partitions 14 are positioned to retain and direct fluid sample in a manner that prevents overflow and facilitates efficient sample flow through the strip 10 . The preferred orientation of the dams 14 are shown in FIG. 1 .
[0030] The above noted operative layers 20 , 30 and 40 are preferably assembled as shown in FIGS. 1 and 4 using accepted techniques in the art and mylar strips 12 , 13 as the support medium for the interior three layers 20 , 30 and 40 . Operative layers 30 and 40 are preferably assembled as shown in FIGS. 6 and 9 when separating layer 20 is omitted. The inside surfaces of the mylar strips have been previously treated with glue to hold the screen and the reaction membrane in place. In some applications it is desirable to select a separating layer 30 which is slightly larger in width than the reaction membrane 40 so that the edges of the separating layer 30 may overlap the reaction membrane 40 and meet the lower mylar strip 13 at the glued surface to aid further in securing the separating layer 30 to the rest of the device. Referring to FIGS. 2-5 , it can be seen that the spreading screen 20 extends beyond the side edges of the separating layer 30 and that the separating layer 30 extends beyond the side edges of the membrane 40 . The spreading layer 20 adheres to the upper support strip 12 and the membrane 40 adheres to the lower support strip 13 . The support strips 12 , 13 are adhered and/or welded together. The spreading screen 20 overextends beyond the separating layer 30 to allow the screen 20 to adhere to the glued surfaces of the support strips 12 , 13 and insures a tight, secure connection between layers 20 , 30 , and 40 . When the spreading screen is omitted, the separating layer 30 may optionally overextend beyond the membrane 40 to allow the separating layer to adhere to the glued surface of support strips 12 , 13 and insure a tight, secure connection between layers 30 and 40 . Once these layers have been assembled, the test strip is inserted into an ultrasonic point welding device and strip welded at the points shown at 14 and 16 in FIG. 1 . This results in the volume control dams 14 and Branson holes 16 . A suitable strip is two (2) inches long by 0.5 inches wide by 0.035 inches thick with a sample receiving port 15 and reaction viewing port 18 of about 0.2 inches in diameter, preferably sized to snugly fit in the shroud of a corresponding commercially available reflective type meter. When the spreading screen is omitted, these dimensions may be reduced to accommodate smaller volumes of analyte. For instance, a suitable reduced analyte volume test strip can be configured to perform an accurate test with about 3 μl, compared to the prevalent 10 μl for optical test strips. When placed in a meter the Branson holes 16 are intended to align and mate with corresponding posts in the meter. The strip may also be read by comparing the color change in the viewing port 18 to a color chart depicting the amount of analyte found, e.g., glucose.
[0031] Proper orientation of the strip 10 in a meter is not always easily ascertainable. To insure that the strip 10 of the instant invention is oriented with the proper surface facing up, the upper surface of the upper support strip 12 includes a light absorption region 19 at one selected end. The light absorption region 19 also serves to indicate the leading end of the strip 10 to be placed in the meter first. Additional indicia in the form of an arrow 21 and blood fluid/fluid drop 23 may also be provided to indicate the direction of insertion and the top surface, respectively. The light absorption region 19 comprises an optically dark, such as black, region adjacent the test area, preferably proximal to the end of the strip. Once inserted, the meter performs a test, such as a light reflection test, to determine whether the strip is properly oriented.
[0032] In addition to the foregoing, the strip 10 of the instant invention is designed to allow a blood/heterogeneous fluid sample to be applied to the strip 10 regardless of whether the strip is inserted in or is outside a meter. This is possible because of the volume control provided by the dam partitions 14 and because of the location of the Branson post 16 as shown in FIG. 1 .
[0033] A spreading screen 20 having a plurality of mesh openings is in contiguous contact with the sample receiving port 15 for receiving and uniformly distributing, or spreading, the heterogeneous fluid over the screen 20 . When blood is being analyzed, the sample is typically applied from a finger stick and comprises approximately 15-50 microliters. However, less sample is now required because of the dam partitions 14 provide volume control to limit overflow and direct sample into the strip. This has the added benefit of improved sanitation. The screen 20 is defined by mesh openings that momentarily hold the sample, via surface tension, as the sample uniformly spreads out over the screen 20 to fill the receiving port. Eventually, the sample passes through the screen mesh 20 to the separating layers 30 to deposit an even distribution of the sample onto the separating layer 30 . A uniform distribution is required to produce uniform color development. This is important because an uneven distribution of the blood, or other heterogeneous fluid, will cause an uneven distribution to the membrane, which will affect the color change therein and produce an unreliable reading. A preferred screen 20 which may be used with the instant invention is a polyester medical screen, designated PeCap/-7-16/8, provided by Tetko, Inc., Elmsford, N.Y., and having a mesh opening of about 16 microns, a thickness of about 75 microns, and an open area of voids of 8% is. The screen is preferably dipped into a 10% solution of sodium chloride and allowed to dry.
[0034] As indicated above, the test strips of the present invention may also be manufactured without a separate spreading screen. The spreading screen 20 may be omitted when, for instance, the separating layer 30 comprises material having sufficient spreading properties. Suitable results have been achieved with separating layers comprising cloth material. Any known or after-discovered material possessing suitable spreading properties with respect to the fluid sample of interest may serve as the separating layer, however. The resulting test strip will thus comprise fewer layers and possess all the advantages inherent therein. Such advantages include, but are not limited to, economies of manufacture and accommodation of smaller analyte sample volumes. The dimensions of the remaining layers and diameters of the sample receiving and viewing ports may also be reduced to accommodate smaller analyte sample volumes, such as 3 μl or less.
[0035] Separating layer 30 comprises a pretreated fabric porous screen material placed in contiguous contact with the lower surface of the spreading screen 20 . For test strips manufactured without a spreading screen 20 , te separating layer 30 may be placed in contiguous contact between the lower surface of the upper support layer 12 and the upper surface of the membrane 40 . The treated separating layer 30 removes approximately 80% of the red blood cells from the blood sample. The remaining blood cells are then removed by the membrane 40 . A preferred separating layer 30 includes a woven fabric of 50% polyester/50% cotton having mesh openings of about 25 microns, open voids area of 16-20%, and a thickness of about 0.010 inches. The separating layer 30 is treated before assembly with one or more agents that bond or adhere to the red blood cells without lysing them so as to avoid releasing red colorization to the reaction membrane. These bonding agents capture the red blood cells and hold them on the separating layer.
[0036] The separating layer 30 should comprise a material that minimizes the absorption of plasma to maximize the plasma which reaches the membrane 40 . This is desirable as it results in requiring less blood from the user. If present, the spreading screen 20 is less dense than the separating layer 30 . Thus, mesh size openings found in the separating layer 30 are smaller than that for the spreading screen 20 , preferably from 20 to 200 microns. The amount of fabric occupied by voids is preferably 15 to 60%. A preferred fabric for the separating layer is polyester, cotton, or a 50/50 polyester-cotton blend.
[0037] The separating layer 30 is preferably pretreated with a blood cell separating agent prior to assembly to enhance filtration. The blood cell separating agents imbibed in the separating layer 30 may be any agent known by a practiced artisan to bind to red blood cells without lysing them. These agents include lectins, antibodies to red blood cells, water soluble salts with potassium citrate, ammonium sulfate, zinc sulfate, and the like Lectins are preferred and include proteins or glycoproteins that recognize specific sequences of polysaccharide residues. The lectin or other binding agent is applied by dipping the separating layer fabric into a solution of the lectin or other agent and allowing the wetted fabric to air dry. The solution can be prepared in concentrations that are easily handled in standard test strip manufacturing equipment. Typically, 2-7% solutions are acceptable. The separating layer 30 is preferably dipped into a 2% solution of a lectin derived from kidney beans and allowed to air dry.
[0038] Numerous other lectins are commercially available. Some commercially available lectins and the specific sugar residues they recognize are Concanavalin A (Alpha-glucose and alpha-D-mannose), soybean lectin (D-galactose and N-acetyl-D-galactosamine), wheat germ lectin (N-acetyl glucosamine), lotus seed lectin (fucose), potato lectin (N-acetyl glucosamine), dilichos biflorus agglutinin (N-acetyl galactose-aminyl), and legume derived lectins such as lentil lectin (Alpha-D-mannose and alpha-D-glucose).
[0039] The membrane 40 is preferably isotropic (symmetrical), that is, uniformly porous. The membrane 40 should be optically white. The membrane 40 provides a medium for holding a reagent and conditioning solution which together produces a color change in the membrane 40 in response to the analyte of interest. In addition, the treated membrane 40 filters the blood sample to remove any remaining red blood cells from the whole blood sample. For other samples, the treated membrane 40 provides necessary filtration as well. A preferred membrane for the detection of glucose analytes comprises a hydrophilic polysulfone membrane having a pore size of 0.2 to 3.0 microns. Such a membrane is manufactured by Gelman Sciences of Ann Arbor, Mich., and has been referred to as Thermopor®. The Supor® 450 membrane is another acceptable membrane which has a pore size of approximately 0.45 microns. Although these membrane are preferred, other isotropic membranes may be used. In fact, membranes produced by other manufacturers may be required for testing analytes other than glucose. Some of these membranes include nylon membranes made by Pall and supported polysulfone membranes made by MSI.
[0040] Prior to assembly of the strip 10 , the membrane 40 is treated with reagents and conditioning agents in a single dip process. Thereafter, the membrane is allowed to dry. It should be noted that the conditioning process may be other than single dip. Preferably, a six-inch wide membrane of Thermopor®, having a pore size between 0.2 and 3.0 microns is dipped into a solution at seven (7) milliliters of solution per linear foot of membrane. A Supor® 450 membrane having a pore size of approximately 0.45 microns may also be used in place of the Thermopor® and dipped in the same solution at the same rate.
[0041] The instant invention comprises a reagent solution that facilitates end-point testing in a corresponding meter. This solution preferably comprises deionized water (700 mL/L), citric acid (tri-sodium salt dihydrate, 52.9 g/L), citric acid (FAM, 4.2 g/L), MAOS (6.6 g/L), 4-Aminoantipyrine (6.1 g/L), 10% Gantrez AN-139 (50 mL/L), polyvinylpyrrolidone and an enzyme solution (100 mL/L). The enzyme solution may include glucose oxidase, peroxidase, 5-dimethoxyaniline, buffers and stabilizers. The prior solution of 4 gms citric acid (free acid monohydrate), 54 g of citric acid (otrisodium salt dihydrate), 60 g polyvinylpyrrolidone, 50 IU/L catalase, 4 g bovin serum albumin (BSA), 0.0055 gm O-Tolidine-Hydrochloride, 0.067 ml. deionized water, 0.0075 gm BSA, 0.0003 gm. glycerol, 11.0 IU peroxidase, 9.5 IV glucose oxidase, 0.002 ml DOSS and 0.003 ml of Gantrez AN-139 may also be used if end-point testing is not conducted.
[0042] Best results are obtained from the reaction membrane when it contains, in addition to the specific reagent solution noted above, certain conditioning agents which improve the performance of the reaction membrane. The conditioning agents are generally incorporated into a blend of the reactants in the solution before the latter are incorporated into the reaction membrane. For example, when preparing a reaction layer for a glucose test strip, a base solution is prepared with citric acid, PVP and BSA. This serves as the base to which the chromogen indicator system and other reactants, e.g. peroxidase and glucose oxidase, are added. It has also been found that the color generation by the reaction is stabilized and its readability enhanced by adding a small amount (0.0005-0.009 ml/L of solution) of DOSS (dioctyl sulfosuccinate sodium) available from Sigma Chemical Company. Gantrez AN 139 (a 2.5 furandione polymer with methoxyethene otherwise known as a methyl vinyl ether copolymer with maleic anhydride) at a level of about 0.0005-0.009 ml/L of solution may also be added to aid in conditioning the membrane.
[0043] In use, one places a drop of blood of about 25 microliters, from a finger stick for example, into the sample receiving port 15 onto the screen surface. The invention can work well with a sample volume from 10 to 50 microliters of sample.
[0044] Prior to the end-point test, a rate test was conducted whereby reflectance was measured by the meter at time equal to forty-five (45) seconds. The rate test; however, does not provide predictable reliability. The end-point test takes reflectance readings at five (5) second increments until successive readings differ by less than five percent (5%). This ensures that the measurement is taken after the reaction has substantially stopped. Since successive measurements are taken until the “end-point” of the reaction, the blood sample may be applied to the strip outside the meter.
[0045] The color obtained at the reaction viewing port 18 of the reaction membrane correlates to the amount of glucose in the original sample. The reading can be done by a visual comparison to a color chart of varied and defined color intensities at various concentrations of glucose. It is preferred that a reflectance meter be used to make a reflectance reading of the reacted color. The meter performs a computer analysis by comparing the reflectance reading to standard reflectances obtained on known concentrations of glucose in reaction with the membrane reactants.
[0046] The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
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An improved multi-layered diagnostic sanitary test strip for receiving a heterogenous fluid, such as whole blood, to test for presence and/or amount of a suspected analyte in the fluid by facilitating a color change in the strip corresponding to the amount of the analyte in the fluid, wherein the test strip includes fluid volume control dams to prevent spillage of the fluid from the strip and a chemical reagent solution that facilitates end-point testing. The improved test strip comprises no more than two operative layers and: (a) a reaction membrane containing a reagent capable of reacting with the analyte of interest to produce a measurable change in said membrane; (b) an upper support layer defining a sample receiving port for receiving the fluid sample thereat; (c) one or more structures for directing the sample containing the analyte of interest through at least a portion of said reaction membrane; and (d) a lower support layer having a reaction viewing port in vertical alignment with said membrane for displaying said measurable change, said lower support being associated with said upper support to secure said reaction membrane in said test strip.
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BACKGROUND OF THE INVENTION
This invention relates to portable apparatus for forming reinforced concrete, hollow core units of a modular building structure, and more particularly to conical spacers used for supporting and spacing supplemental forms in parallel relationship to primary forms of a core unit and for providing locating holes when removed for vertical alignment of the core unit for casting multi-storied structures.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. Nos. 3,993,720 and 4,029,287 disclose apparatus for forming modular building structure with both patents disclosing nonremovable conical spacers adapted to support and space vertical steel plates of supplemental forms in parallel relationship the required distance from the vertical steel plates of the primary form. Since these nonremovable conical spacers can only serve a single given function, a need exists for removable conical spacers that not only can be used again but the hole from which they have been removed can also serve as a means for later form alignment purposes.
SUMMARY OF THE INVENTION
In accordance with the invention claimed, an improved spacer is provided for use in forming hollow core modular building structures of single or multi-story construction.
It is, therefore, one object of this invention to provide an improved conical shaped spacer for use in forming modular building structures.
Another object of this invention is to provide an improved conical spacer for spacing form components and when cast in concrete decks may be removed to provide alignment holes for sequential multi-storied form use.
A further object of this invention is to provide an improved apparatus for forming modular building structures which employs removable conical spacers used for spacing and alignment purposes.
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 a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily described by reference to the accompanying drawing in which:
FIG. 1 is a front end elevational view of an assembled inner form or cell structure showing the side wall, ceiling and corner filler components of the device in fully expanded relationship with removable side panels of a supplemental form shown in combination with the novel conical spacers disclosed and claimed herein;
FIG. 2 is a partial sectional view of a conical tapered hole in a precast deck formed by use of the claimed spacer used as a location means for a plunger of a cell structure for alignment purposes;
FIG. 2A is a sectional view showing how the conical spacer is held in place in the form prior to casting the deck shown in FIGS. 1 and 2;
FIG. 3 is a view similar to FIG. 2 showing the plunger of the form assembly penetrating the hole formed by the spacer previously removed;
FIG. 4 is a view similar to FIG. 3 with the plunger fully in place in the taper hole previously formed by the spacer disclosed herein;
FIG. 5 is a cross sectional view of plunger and one of its guiding frames;
FIG. 6 is a perspective view of a spacer and guide frame supporting a rebar;
FIG. 7 is a view partially in section of a spacer support frame and rebar in cast concrete; and
FIG. 8 is a view showing the spacer being removed from its position shown in FIG. 7 to provide an alignment hole.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings by characters of reference, FIG. 1 discloses an assembled inner form or cell structure 10 for use in precasting hollow core construction comprising right and left side wall assemblies or frames 11 and 12, respectively, and a top or ceiling assembly 13.
It should be noted that the inner form of cell structure 10 is capable of being utilized to produce a plurality of single story interconnected hollow core concrete units in side by side relationship or a plurality of similar units in high rise relationship of two or more storied structures. Therefore, when the cell structure is being set up to produce the first story of a multiple unit structure, the side walls 11 and 12 of the forms are allowed to rest on the level inner top surfaces of the previously prepared concrete footings or on a floor or ground surface as indicated in FIG. 1 of the drawings. When being set up to produce a second and subsequent stories of the structure, the side walls 11 and 12 are supported a slight distance above the level surfaces of the floor/ceiling portion of the finished hollow core unit directly below as described in U.S. Pat. No. 4,029,287 which is incorporated herein by reference.
Each cell structure 10 includes two or more bridge like heavily constructed steel inner frame members 18, the quantity depending on the overall length of the cell structure and each inner frame consists of a horizontal tie beam 19 and a pair of depending side members 20 and 21. The frame member is preferably fabricated of standard I-Beam steel stock which is welded to form a perfectly squared contiguous form which is installed in the interior of cell structure 10 in spaced parallel relationship to the side wall assemblies 11 and 12 and the top or ceiling assembly 13. This frame member is arranged to move or reciprocate vertically with assemblies 11, 12 and 13 to which it is rigidly secured by longitudinally disposed parallel I-beams 22. These I-beams 22 extend between the inner surface of the ceiling assembly over and beyond the horizontal top surfaces of the bridge like inner frame members 18. The depending vertical side members 20 and 21 are movably associated with the side wall assemblies 11 and 12 by pairs of hydraulic cylinders 23, pairs of outwardly extending angle brackets 24 having removable pins, and pairs of pivoting link and bracket assemblies 25.
The side wall assemblies 11 and 12 and the top or ceiling assemblies 13 are preferably fabricated of heavy gauge steel plates that are perfectly flat and smooth on their outer surfaces having welded thereto on their inner surfaces a plurality of equally spaced, parallel vertical or horizontally disposed reinforcing ribs 26. The ceiling plate is just wide enough to extend beyond the ends of the horizontal ribs 27 to provide an equal right angle opening or vacated space 28 which extends the full length of the inner form or cell 10 when the same is in either its fully expanded or contracted position to allow for the manual insertion or removal of the longitudinal segments of suitable split, flexible, corner filler pieces 29 into or out of the right angle openings 28. The filler pieces are provided to square off and close the corner openings in preparation for the forming of a hollow core concrete unit and to allow for removal of the inner form or cell from the formed unit when the concrete is set.
Reference is made to the description in U.S. Pat. No. 4,029,287 for a more detailed description of cell structure 10 and its function.
When the building project calls for the construction of single or multiple width side by side hollow core concrete units of either one or several stories high, the inner form or cell structure 10 is set up or installed so that the opposed smooth outer surfaces of the side plates of the side wall assemblies 11 and 12 are spaced apart the required distance. In order to form the outside vertical side walls of the cell, it is necessary to utilize supplement frame members or forms of any suitable type having smooth surfaced vertically mounted steel plates 30 (indicated in FIG. 11). These plates are temporarily attached to side wall plates 11 and 12 by means of removable bolts or studs which are threaded through the respective vertical plates from both sides thereof into the threaded bores of a plurality of removable conical spacers 31 embodying the invention. These spacers are adapted to support and space the vertical steel plates 30 of the supplemental forms in parallel relationship the required distance from the vertical steel plates 11 and 12.
When the particular hollow core concrete units of the building structure are cured, these forms can quickly be removed from their described attachment to side plates 11 and 12 of the side wall assemblies of the cell structure by simply removing the bolts or studs from the plates and conical spacers 31. Spacer 31 are then removed from the finished concrete walls for reuse.
The inner form or cell structure 10 may be utilized to form the hollow core units of a high rise or several storied building structure and the difficult task of setting up or installing the cell structures on the top surface of the finished floor/ceiling portion 15 of the concrete units in proper aligned and spaced relationship for forming the next story of the building structure has been simplified by the utilization of spacers 31.
The conical spacer 31, as shown in FIGS. 2A and 6, comprises an elongated plastic or metallic conical housing 32 having a smooth outer surface and a threaded aperture 33 extending axially therethrough or at least a part thereof for receiving a threaded bolt 34 at either or both ends thereof.
This spacer is then used, as shown in FIG. 1, for spacing and supporting the vertical steel plates 30 of the supplemental forms to the wall assemblies of the cell structure by bolts 34 extending through apertures in the supplemental form and the steel plates and into the spacers for holding them in a predetermined position between the supplemental form and the cell structure.
To aid in holding rebars in place between the supplemental forms and the steel plates 11 and 12 an apertured circular shaped clamp 35 may be secured to rebars 36 and the conical spacer. As shown in FIGS. 5-7, housing 32 of spacer 31 is longitudinally moved through the aperture in the clamp until a snug fit occurs at a given point along its length, thereby holding the rebar in the center of the gap between the supplemental form and members 11 and 12 during a concrete pouring operation. Depending on the size of the aperture of clamp 35, the rebar may be placed at various places in the poured concrete.
After concrete 37 is poured and set the spacer is removed, as shown in FIG. 8, since it is no longer needed to hold in position the rebar.
If the building structure is to be two or more stories high, spacer 31 is used to provide form alignment holes 38 in the ceiling of the first and/or any story of the multi-story building. To accomplish this function the conical spacers are positioned in a ceiling of the module of the building in the same manner as disclosed above with the spacer tapering downwardly, as shown in FIGS. 2 and 2A.
Then after removal of the spacer by the removal of the spacer bolt 34, the housing is withdrawn upwardly leaving a tapering hole 38 in the ceiling of the building.
In order to receive and position the inner form or cell structure 10 in parallel alignment, above the top floor/ceiling 15 of the finished lower structure, the above described tapered holes 38 are used by parts of the cell form mounted above the ceiling of the lower structure for alignment purposes.
As shown in FIGS. 2-4, an alignment plunger 40 of the form forming a part of cell structure 10 is mounted above holes 38 and is reciprocally moved into holes 38 by its handle 41 for form aligning purposes and is sequentially moved out of these holes later when the concrete of the newly poured upper story has set.
Although but one embodiment of the invention has been shown 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 conical spacer assembly for supporting and spacing one member relative to another member comprising a conical housing having a smooth outer surface and hole extending axially therethrough for receiving at one or both ends thereof a bolt in threaded arrangement therewith. A flat circular shaped clamp having an aperture extending laterally therethrough is provided for receiving through its aperture the housing of the spacer which clamp snugly engages the housing at a point along its length laterally thereof and engages and supports a rebar at one or more point around its periphery.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 09/934,936, filed Aug. 22, 2001 now U.S. Pat. No. 6,833,424, the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a polyurea coating composition that can be applied as a wet finish on any substrate. More particularly, the present invention relates to a two component polyurea coating composition that exhibits a dual cure phenomena.
Two component coating compositions containing a polyisocyanate component in combination with an isocyanate-reactive such as a polyhydroxyl component or a polyamine are known. These coating compositions are suitable for the formation of high quality coatings and can be adjusted to produce coatings which are hard, elastic, abrasion resistant, solvent resistant and weather resistant.
Generally, there are two mechanisms by which the curing of polyurea coating compositions takes place-moisture cure or plural component “fast cure” which involves cross-linking the polyisocyanate component with an amine. Aliphatic coating compositions which rely upon moisture cure demonstrate very slow curing times which can limit their use in some applications. Coating compositions which rely upon plural “fast cure” are susceptible to adhesion problems when the curing proceeds too quickly.
In accordance with the present invention, polyurea coating compositions based on a two component system of a polyisocyanate component and a polyaspartic ester isocyanate-reactive component are produced which demonstrate a dual cure phenomena which results in improved film properties and curing times.
SUMMARY OF THE INVENTION
According to other features, characteristics, embodiments and alternatives of the present invention which will become apparent as the description thereof proceeds below, the present invention provides a polyurea coating composition that exhibits a dual cure phenomena, the polyurea coating composition including:
a polyaspartic ester; and a polyisocyanate, wherein the polyisocyanate is present in an amount that is greater than a normal stoichiometric amount for the polyaspartic ester.
The present invention further provides a method of preparing a polyurea coating composition which involves:
providing a polyaspartic ester; providing a polyisocyanate; and mixing the polyaspartic ester and the polyisocyanate together so that the polyisocyanate is present in an amount that is greater than a normal stoichiometric amount for the polyaspartic ester.
The present invention also provides a surface finish which comprises a cured composition that includes a polyaspartic ester and a polyisocyanate, wherein the polyisocyanate is present in an amount that is greater than a normal stoichiometric amount for the polyaspartic ester prior to curing.
The present invention still further provides a method for a forming a surface finish which involves:
providing a polyaspartic ester; providing a polyisocyanate; mixing the polyaspartic ester and the polyisocyanate together so that the polyisocyanate is present in an amount that is greater than a normal stoichiometric amount for the polyaspartic ester; applying the mixed composition to a surface to form a surface coating; and allowing the applied surface coating to cure.
The present invention further provides a coated object of:
a substrate; and a coating on the substrate of a polyurea coating composition including
a polyaspartic ester, and a polyisocyanate, wherein the polyisocyanate is present in an amount that is greater than a normal stoichiometric amount for the polyaspartic ester, and wherein the coating composition cures dry to handle after air drying at 72° F. and 40% relative humidity in less than 120 minutes.
DETAILED DESCRIPTION OF THE INVENTION
The polyurea coating compositions of the present invention provide a hybrid curing system that combines the “fast cure” of a polyaspartic ester polyurea reaction with the enhanced adhesion and superior film properties of a slower curing moisture cure polyurea. The polyurea coating compositions of the present invention demonstrate enhanced adhesion, rapid cure rates and light stability, and can be used to produce bubble free, low to high film builds wit thicknesses that range from less that 1 mil to greater thank 20 mil.
The coating compositions of the present invention comprise two component polyureas that have exceptional direct-to-substrate adhesion and are based the use of a polyaspartic ester that is over indexed with a polyisocyanate. On component is a polyaspartic ester based component that can be pigmented or clear and incorporated with or without solvents. The other component is a polyisocyanate that can be incorporated with or without solvents.
Suitable polyisocyanates for use in accordance with the present invention include aliphatic polyisocyanates such as hexamethylenediisocyanate (HDI) and lysine diisocyanate; alicyclic polyisocyanates such as dicyclohexylene diisocyanate, isophorone diisocyanate (IPDI), cyclohexane diisocyanate (CHDI); aromatic polyisocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI); and mixtures thereof. Higher functional Biruet polyisocyanates are usually preferred over trimers, dimmers, and hexamethylenediisocyanate (HDI) was found to be particularly useful for purposes of the present invention.
Suitable polyaspartic esters include single polyaspartic esters, or blends, such as those disclosed in U.S. Pat. Nos. 5,126,170; 5,243,012; 5,736,604 and 6,458,293, the disclosures of which are hereby incorporated by reference.
In formulating the coating compositions of the present invention, the polyaspartic ester is over indexed with an aliphatic polyisocyanate. That is, the polyisocyanate was used in an amount that is greater than the stoichiometric amount one would normally calculate for a specific amount of a polyaspartic ester. During the course of the invention, the applicant determined that measurable improvements in the film properties of a coating produced from the polyurea coating compositions of the present invention were obtained at an over indexing of the polyaspartic ester to a polyisocyanate at above about 1.5 NCO to NH. Optimum film properties were obtained without the use of a secondary catalyst at an over indexing of the polyaspartic ester to a polyisocyanate at above about 2.5±0.5 NCO to NH. When over indexing the polyaspartic ester with a polyisocyanate above about 3.0 NCO to NH, without the use of a secondary catalyst, the air dry cure times increase unfavorably.
Although not intending to be bound by an particular theory, and understanding that an applicant need not comprehend the scientific principles on which the practical effectiveness of his invention rests, applicant theorizes that by selectively over indexing the polyaspartic ester to the polyisocyanate, it is possible to reach an optimum balance between moisture curing and “fast curing” which involves cross-linking the polyisocyanate component with an aliphatic amine. When the mechanism of moisture curing predominates, surface adhesion is optimized; however, the curing times are very long and the film is susceptible to the formation of CO 2 bubbles when the applied dried film thickness exceeds 5 mil, or under high humidity conditions. When the cross-linking mechanism associated with fast curing predominates, surface adhesion is reduced in favor of quicker curing times. Applicant has determined that within an over indexing range of from about 1.5 up to about 3.0 of NCO to NH, the polyurea coating compositions of the present invention demonstrate a dual cure property in which the cross-linking mechanism associated with fast curing causes the surface of a coating to dry relatively fast, while the mechanism of moisture curing at the interface between the coating layer and substrate allows the coating composition to cure more slowly and thereby develop good adhesive properties.
The polyurea coating compositions of the present invention can be applied to virtually any surface as a wet coating which can be applied in any conventional manner such as spraying, dipping, brushing, etc. Once applied, if desired, the coatings can be air dried or forced dried according to conventional methods. The coating compositions can be suitably applied over a temperature range of about 40° F. to about 95° F. and relative humidity levels of about 40% to about 95%.
The polyurea coating compositions of the present invention have been found to produce finishes that have strong adhesion properties, high tensile strengths, chemical resistance to solvents and other chemical agents, resistance to ultraviolet light, and excellent color and gloss retention. The finishes are hard as well as impact and chip resistant, and can be recoated as desired. The coatings of the present invention can be applied to substrates such as cement, asphalt, metal, glass, and wood. The coatings may be used as an overcoat, on top of other coatings or treated surfaces such as zinc coated or zincated surfaces.
It is noted that the polyurea coating compositions can include single polyaspartic esters or blends of polyaspartic with or without additional catalytic agents. In addition, the compositions can include other conventional components such as pigments, dyes, fillers, carriers, solvents, surface texturing agents, etc. For convenience of field use, the two components of the compositions can be formulated to be mixed in a 1:1 ratio. Such a mixing ratio eliminates the need for measuring different amounts of the two components. The coating compositions have been determined to be particularly useful as an alternative to conventional coatings that require baking, when the parts or articles to be coated are too large or otherwise unsuitable for baking.
The following non-limiting examples were conducted to evaluate performance characteristics of the polyurea coating compositions of the present invention. The polyurea coating compositions tested in the following examples were non-pigmented clear coats that were applied at a dry film thickness (DFT) of 2 mil. The coating compositions were batch mixed and air spray applied.
Performance characteristics in the examples were evaluated using the following evaluation scale (ranging from 0 to 5):
0=Total Failure 1=Near Total Failure 2=Partial Failure 3=Marginal 4=Acceptable 5=Excellent
EXAMPLE 1
Crosshatch Adhesion
In this Example, non-pigmented coatings were tested according to the procedure set forth in ASTM 1-3359-95, Test Method B. The test results are presented in Table 1 below:
TABLE 1
Bonderite 1000
Stoichiometric
Untreated Cold
Pre-Treated Cold
Grit Blasted
Index
Rolled Steel
Rolled Steel
Steel
1.00
0
4
2
1.25
0
4
2
1.50
1
5
3
1.75
2
5
4
2.00
3
5
4
2.25
4
5
5
2.50
5
5
5
2.75
5
5
5
3.00
5
5
5
EXAMPLE 2
Conical Mandrel
In this Example, non-pigmented coatings were tested according to the procedure set forth in ASTM D 522-93, Test Method A. The test results are presented in Table 2 below.
TABLE 2
Bonderite 1000
Stoichiometric
Untreated Cold
Pre-Treated Cold
Grit Blasted
Index
Rolled Steel
Rolled Steel
Steel
1.00
0
3
N/A
1.25
0
4
N/A
1.50
0
4
N/A
1.75
1
5
N/A
2.00
2
5
N/A
2.25
4
5
N/A
2.50
5
5
N/A
2.75
5
5
N/A
3.00
5
5
N/A
EXAMPLE 3
Recoat, Chemical Resistance and Drying
In this Example, non-pigmented coatings were tested according to the procedures set forth in ASTM D 3359-95, Test Method B (for recoat) and ASTM D 1308-87 (for Chemical resistance using n-methyl N-methylpyrrolidinone (NMP), 37% HCl, 20% HCl, 100% acetic acid and 50% acetic acid). In addition, drying characteristics were tested as indicated. The test results are presented in Table 3 below.
TABLE 3
Recoat After
Chemical
Dry to Handle
48 Hour Cure:
Resistance
Air Dry @ 72° F.
Stoichiometric
Intercoat
After 30
and 40% Relative
Index
Adhesion
Day Cure
Humidity @ 2 mils DFT
1.00
0
2
<30 Minutes
1.25
1
3
<45 Minutes
1.50
2
3
<45 Minutes
1.75
3
3
<45 Minutes
2.00
4
4
<45 Minutes
2.25
5
4
<60 Minutes
2.50
5
5
<60 Minutes
2.75
5
5
<75 Minutes
3.00
5
5
<120 Minutes
EXAMPLE 4
Exposure to UV Light
In this Example, Gloss White coatings were tested according to the procedure set forth in ASTM D 4587-91, Procedure A (8 hour UV/70° C. followed by 4 hour CON/50° C.). The test results are presented in Table 4 below.
TABLE 4
42 Day
42 Day
Stoichiometric Index
QUV-B 60 Gloss
QUV-B Delta E
1.00–89.9 Gloss White
52.1
0.609
2.50–96.2 Gloss White
78.7
0.411
EXAMPLE 5
Black Semi Gloss
In this example Black Semi Gloss coatings were prepared as follows:
TABLE 5
Percent
Suppl
Solvent
%
# Raw Material
EqWt
Solids
lb/gal
lb/gal
H20
1.
ASPARTIC BLACK
313.00
100
9.17
0.00
0
430
2.
WOLLASTOCOAT
0.00
100
24.20
0.00
0
M-400 AS
3.
ACEMAT HK 188
0.00
100
17.50
7.51
0
4.
BYK 307 10% IN
0.00
9
7.61
7.51
0
EA
5.
ACETATE
0.00
0
7.29
7.29
0
6.
DESMODUR N100
382.00
50
8.40
7.53
0
50% CUT
1.
ASPARTIC BLACK
207.92
22.67
207.92
22.67
0
430
2.
WOLLASTOCOAT
158.06
6.53
158.06
6.53
0
M-400 AS
3.
ACEMAT HK 188
29.64
1.69
29.64
1.69
0
4.
BYK 307 10% IN
1.80
0.24
0.16
0.02
0
EA
5.
ACETATE
137.23
18.82
0.00
0.00
0
6.
DESMODUR N100
420.33
50.04
210.17
22.13
0
50% CUT
7.
Total
954.99
100.00
605.95
53.05
Weight Solids, ⅔ =
63.45
Weight/gallon =
9.55
Volume Solids, ⅓ =
53.05
NCO: OH Ratio =
1.66
P/3 Ratio =
0.45
Mix Ratio =
1.00
PVC, % =
15.51
VOC, lbs/gal =
3.49
# Raw Material
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
2. a surface modified wollastonite from NYCO, Calgary, Alberta, Canada
3. a filler/glass flattening agent from Degausa Corp., Düsseldorf, Germany
4. a silicon surface additive from Byk Chemie, Wessel, Germany
5. Acetate
6. An aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, PA.
EXAMPLE 6
High Gloss White
In this example High Gloss White coatings were prepared as follows:
TABLE 6
Percent
Suppl
Solvent
%
# Raw Material
EqWt
Solids
lb/gal
lb/gal
H20
1.
DESMOPHEN 7053
277.00
100
8.83
0.00
0
2.
Ti-Pure R-900
0.00
100
33.30
0.00
0
3.
Aerosil 200
0.00
100
18.40
0.00
0
4.
Aerosil R-972
0.00
100
18.40
0.00
0
5.
Disperbyk-160
0.00
29
7.93
7.27
0
6.
BYK 307 10% IN
0.00
9
7.61
7.51
0
EA
7.
ACETATE
0.00
0
7.29
7.29
0
8.
DESMODUR
272.00
70
8.90
7.51
0
N-100/ea 30%
1.
DESMOPHEN 7053
181.67
20.57
181.67
20.57
0
2.
Ti-Pure R-900
442.67
13.29
442.67
13.29
0
3.
Aerosil 200
1.89
0.10
1.89
0.10
0
4.
Aerosil R-972
2.83
0.15
2.83
0.15
0
5.
Disperbyk-160
4.72
0.59
1.37
0.13
0
6.
BYK 307 10% IN
1.89
0.25
0.17
0.02
0
EA
7.
ACETATE
109.19
14.98
0.00
0.00
0
8.
DESMODUR
445.49
50.05
311.84
32.26
0
N-100/ea 30%
9.
Total
1190.35
100.00
942.44
66.54
Weight Solids, ⅔ =
79.17
Weight/gallon =
11.90
Volume Solids, ⅓ =
66.54
NCO:OH Ratio =
2.50
P/B Ratio =
0.91
Mix Ratio =
1.00
PVC, % =
20.41
VOC, lbs/gal =
2.48
# Raw Material
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
2. titanium dioxide from DuPont de Nemours, Willmington, Delaware.
3. a silicon from Degausa Corp., Düsseldorf, Germany
4. a silicon from Degausa Corp., Düsseldorf, Germany
5. a wetting agent from BYK Chemie, Wessel, Germany
6. a silicon surface additive from BYK Chemie, Wessel, Germany
7. Acetate
8. An aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, PA.
EXAMPLE 7
Blended Aspartic
In this example a blend of polyaspartic esters was used to prepare coating as follows:
TABLE 7
Percent
Suppl
Solvent
%
# Raw Material
EqWt
Solids
lb/gal
lb/gal
H20
1.
DESMOPHEN 7053
277.00
100
8.83
0.00
0
2.
DESMOPHEN 7052
325.00
90
8.66
7.35
0
3.
Ti-Pure R-900
0.00
100
33.30
0.00
4.
BAROTE 1075
0.00
100
33.00
0.00
0
3.
Aerosil 200
0.00
100
18.40
0.00
0
6.
Methyl Ethyl
0.00
9
6.71
6.71
0
Ketone
7.
DESMODUR
224.00
85
9.19
7.51
0
N-100/ea 15%
1.
DESMOPHEN 7053
122.83
13.91
122.83
13.91
0
2.
DESMOPHEN 7052
18.70
2.16
16.83
1.91
0
3.
Ti-Pure R-900
436.44
13.11
436.44
13.11
0
4.
BAROTE 1075
87.29
2.65
87.29
2.65
0
3.
Aerosil 200
4.36
0.24
4.36
0.24
0
6.
Methyl Ethyl
288.07
25.01
0.00
0.00
0
Ketone
7.
DESMODUR
229.84
25.01
195.37
20.42
0
N-100/ea 15%
8.
Total
1187.53
100.00
863.12
52.22
Weight Solids, ⅔ =
72.68
Weight/gallon =
11.88
Volume Solids, ⅓ =
52.22
NCO:OH Ratio =
2.05
P/B Ratio =
1.58
Mix Ratio =
3.00
PVC, % =
30.62
VOC, lbs/gal =
3.24
# Raw Material
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
2. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
3. titanium dioxide from Degausa Corp., Düsseldorf, Germany
4. barium sulfate
5. a silicon from Degausa Corp., Düsseldorf, Germany
6. Methyl Ethyl Ketone
7. an aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, PA.
EXAMPLE 8
Metallic Over Indexed
In this example coatings having a metallic finish were prepared as follows:
TABLE 8
Percent
Suppl
Solvent
%
# Raw Material
EqWt
Solids
lb/gal
lb/gal
H20
1.
DESMOPHEN 7053
277.00
100
8.83
0.00
0
2.
Aerosil 200
0.00
100
18.40
0.00
0
3.
Sparkle Silver
0.00
62
12.08
6.55
0
5251-AR
4.
BYK 307 10% IN
0.00
9
7.61
7.51
0
EA
5.
Acetate
0.00
9
7.53
7.53
0
6.
DESMODUR
318.00
60
8.74
7.51
0
N-100/ea 40%
1.
DESMOPHEN 7053
241.97
27.40
241.97
27.40
0
2.
Aerosil 200
2.83
0.15
2.83
0.15
0
3.
Sparkle Silver
54.67
4.53
33.90
1.35
0
5251-AR
4.
BYK 307 10% IN
1.62
0.21
0.15
0.02
0
EA
5.
Acetate
134.10
17.81
0.00
0.00
0
6.
DESMODUR
436.09
79.90
261.65
25.67
0
N-100/ea 40%
7.
Total
871.28
100.00
540.50
55.60
Weight Solids, ⅔ =
62.04
Weight/gallon =
8.71
Volume Solids, ⅓ =
53.60
NCO:OH Ratio =
1.37
P/B Ratio =
0.07
Mix Ratio =
1.00
PVC, % =
2.71
VOC, lbs/gal =
3.31
# Raw Material
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
2. a silicon from Degausa Corp., Düsseldorf, Germany
3. a metallic silver pigment
4. a silicon surface additive from BYK Chemie, Wessel, Germany
5. Acetate
6. an aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, PA.
EXAMPLE 9
Blend with Aldimine
In this example a blend of polyaspartic esters was used to prepare coatings as follows:
TABLE 9
Percent
Suppl
Solvent
%
# Raw Material
EqWt
Solids
lb/gal
lb/gal
H20
1.
DESMOPHEN 7053
277.00
100
8.83
0.00
0
2.
DESMOPHEN 7052
325.00
90
8.66
7.35
0
3.
Desmophen XP-7076
139.00
100
7.30
0.00
0
4.
BYK 307 10% IN EA
0.00
9
7.61
7.51
0
5.
Byk-321
0.00
52
7.51
7.52
0
6.
Acetate
0.00
0
7.29
7.29
0
7.
Desmodur XP-7100
205.00
100
9.50
0.00
0
1.
DESMOPHEN 7053
214.31
24.27
214.31
24.27
0
2.
DESMOPHEN 7052
71.12
8.21
64.01
7.24
0
3.
Desmophen XP-7076
31.50
4.32
31.50
4.32
0
4.
BYK 307 10% IN EA
0.95
0.13
0.09
0.01
0
5.
Byk-321
0.00
52
7.51
7.52
0
6.
Acetate
94.30
12.94
0.00
0.00
0
7.
Desmodur XP-7100
475.73
50.08
475.73
50.08
0
8.
Total
888.39
100.00
785.88
85.95
Weight Solids, ⅔ =
88.46
Weight/gallon =
8.88
Volume Solids, ⅓ =
85.95
NCO:OH Ratio =
1.90
P/B Ratio =
0.00
Mix Ratio =
1.00
PVC, % =
0.00
VOC, lbs/gal =
3.03
# Raw Material
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
2. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
3. a polyaspartic ester from Bayer Material Science, Pittsburgh, PA.
4. a silicon surface additive from BYK Chemie, Wessel, Germany
5. a silicon surface additive from BYK Chemie, Wessel, Germany
6. Acetate
7. an aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, PA.
EXAMPLE 10
Childlife Green
In this example coatings having a childlike green finish were prepared as follows:
CHILDLIFE GREEN POLYOL
# Raw Material
QUANTITY
UNITS
DESMOPHEN NH1420 (XP-7053) DA-
82.86
Lb
ASPARTIC YELLOW OXIDE SHADE PA
51.79
Lb
GREEN ASPARTIC SHADE PASTE
60.00
Lb
ASPARTIC BLACK SHADE PASTE
30.00
Lb
WOLLASTACOAT M-400 (10012)
273.59
Lb
DESMPHEN 1220
54.45
Lb
BYK 307 10% IN ACETATE
0.77
Lb
T-12 (10% IN PMA)
1.27
Lb
ACETATE 99%
16.04
Lb
1. a polyaspartic ester from Bayer Material Science, Pittsburgh, Pa.
2. color shade
3. color shade
4. color shade
5. color shade
6. a surface modified wollastonite from NYCO, Calgany, Alberta, Canada
7. a polyaspartic ester from Bayer Material Science, Pittsburgh, Pa.
8. a silicone surface additive from Byk Chemie, Wessel, Germany
9. a tin catalyst
10. Acetate
PHYSICAL PROPERTIES
DESCRIPTION
VALUE
TOTAL WEIGHT
880.864
TOTAL VEH WT %
100.000
PIGMENT WT %
0.000
VOLATILE WT %
30.000
ORG. SOLV. WT %
30.000
SOLIDS WT %
70.000
VEH SOLIDS WT %
70.000
DENSITY
8.809
BULKING FACTOR
0.114
P/B RATIO
0.000
CPSFA @ 1 MIL
0.0265
MATERIAL VOC
316.662
TOTAL VOLUME
100.000
TOTAL VEH VOL %
100.000
PIGMENT VOL %
0.000
VOLATILE VOL %
35.094
ORG. SOLV. VOL %
35.094
SOLIDS VOL %
64.906
VEH SOLIDS VOL %
64.906
SPEC. GRAVITY
1.058
P.V.C. %
0.000
SPREAD @ 1 MIL
1041.089
COATING VOC
316.662
CHILDLIFE GREEN ACTIVATOR
# RAW MATERIAL
QUANTITY
UNITS
DESMODUR N-100 (TOLONATE HDB)
616.61
Lb
ACETATE 99%
264.26
Lb
1. an aliphatic polyisocyanate from Bayer Material Science, Pittsburgh, Pa.
2. ethyl acetate
PHYSICAL PROPERTIES
DESCRIPTION
VALUE
TOTAL WEIGHT
629.948
TOTAL VEH WT %
44.389
PIGMENT WT %
55.611
VOLATILE WT %
3.331
ORG. SOLV. WT %
2.728
SOLIDS WT %
96.669
VEH SOLIDS WT %
41.057
DENSITY
13.295
BULKING FACTOR
0.075
P/B RATIO
0.354
CPSFA @ 1 MIL
0.0180
MATERIAL VOC
43.455
TOTAL VOLUME
47.384
TOTAL VEH VOL %
70.363
PIGMENT VOL %
29.637
VOLATILE VOL %
5.988
ORG. SOLV. VOL %
4.793
SOLIDS VOL %
94.012
VEH SOLIDS VOL %
64.375
SPEC. GRAVITY
1.597
P.V.C. %
31.524
SPREAD @ 1 MIL
1507.950
COATING VOC
43.980
EXAMPLE 11
Gloss White Over Zinc Rich Primer
In this example Gloss White coatings of the present invention were topcoated over a zinc rich moisture cure urethane (i.e. zinc rich urethane-ZRU) primer.
ZRU PRIMER
Finish:
Flat
Color:
Gray
Volume Solids:
63% ± 2%
Weight Solids:
87.9% ± 2%
Theoretical VOC:
<340 g/l: 2.8 lbs/gal
Zinc Content in Dry Film:
86% ± 2%
Theoretical Coverage
Wet mils:
3.0 to 8.0
Dry mils:
2.0 to 5.0 above profile
Coverage:
202 to 336 sq ft theoretical
Drying Schedule @ 5.0 mils wft 77° F. 5% RH:
Unaccelerated
Accelerated
To Touch:
20 minutes
5 minutes
To recoat: atomospheric
4–6 hours
5 minutes
To cure: atomospheric
3 days
6–8 hours
Drying time is temperature, humidity and film thickness dependent.
Shelf Life:
6 months unopened
Store indoor at 40° F.–100° F.
GLOSS WHITE TOPCOAT
Finish:
Gloss White
Volume Solids:
53.5%–85.5% ± 2%
Weight Solids:
60%–88% ± 2%
Theoretical VOC:
<384 g/l: 3.2 lbs/gal*
Typical Exampel - can vary based on
customer requirements with higher
solids lower VOC capability.
Mix Ratio:
1:1 to 2:1
Induction Time:
None
Theoretical Coverage:
@ 57% Volume Solids equals 914 sq ft
@1 mil DFT
Shelf Life:
12 months unopened
Store indoor at 40° F.–100° F.
Hardness:
H–2H
Direct Impact:
>320 inch/lbs
Reverse Impact:
>160 inch/lbs
Conical Mandrel:
⅛″ pass
Gravel-O-Meter:
5+
Graffiti and Chemical Resistance:
Good
Salt Spray Direct:
B-1000 @ 2.5 mils DFT
>500 hours
Gloss White @ 2.5 mils DFT
Over 3.5 mils DFT ZRU
>10,000 hours
Drying Schedule @ 2.0 mils WFT
77° F. 50% RH
To Touch:
20 minutes
To Handle:
40 minutes
Drying time is temperature, humidity
and film thickness dependent.
Weathering:
QUV-A
Gloss White
60 Gloss
D E*
Initial
2400 hours
2400 hours
92
88
<2.0
Florida
Gloss White
60 Gloss
D E*
Initial
24 months
24 months
92
87
<2.5
RECOMMENDED USES
On steel, aluminum and galvanized where resistance to rust and corrosion undercutting is required
As a primer for urethane coatings system
Low temperature cure application
As a spot primer on hand and power tool cleaned surfaces
Product Finish
Structural Steel
General Maintenance
Industrial and Transportation
From the above examples, it can be seen that the properties of the polyurea coating compositions of the present invention begin improving as the polyaspartic ester is over indexed with polyisocyanate at above a 1.00 and continues to improve up to a stoichiometric index of about 2.25, after which the properties maintain the level of improvement.
Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications can be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as described above and set forth in the following claims.
|
A two component polyurea coating composition that exhibits a dual cure phenomena. The coating composition comprises a polyaspartic ester that is combined together with a polyisocyanate in such a manner that the polyisocyanate is present is an amount that is greater than a normal stoichiometric amount for the polyaspartic ester. By over indexing the polyaspartic ester with the polyisocyanate advantages of moisture curing and or “fast curing” can be combined together in the final finish.
| 2
|
FIELD OF THE INVENTION
This invention relates to pyrotechnic compositions based upon the reaction between aluminum and calcium sulfate.
BACKGROUND OF THE INVENTION
Aluminum and calcium sulfate incendiaries have been used for specialized purposes for a number of years. However, this mixture has never been used to a great extent for several reasons, each one being sufficient to prevent its general use. They are:
1. To obtain sufficient heat on a unit weight basis the amount of aluminum has to be increased to the point that ignition becomes too difficult.
2. During the curing exotherm some of the aluminum is attacked by the calcium sulfate water mixture used, with the evolution of hydrogen gas.
3. When the cast mixture is heated for an extended period of time at temperatures of 150° F. and higher, gas is evolved which in itself makes the material unsuitable for use in normal magazine conditions. In addition at least part of this gas is water of hydration from CaSo 4 .2H 2 O, the loss of which causes the physical properties of the cast material to deteriorate.
4. The cast material is too light. Therefore its volumetric loading efficiency is not adequate.
BRIEF DESCRIPTION OF THE INVENTION
This invention comtemplates the combination of aluminum, calcium sulfate and magnesium sulfate, together with such an amount of water as results in cured structure which while curing involved minimal exotherm, physical swelling, and gas evolution, in which the heat output and density are significantly increased relative to known aluminum/calcium sulfate compositions, and which are readily ignitable by suitable igniters.
This invention will be fully understood from the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention comprises a cured product produced from a mixture of finely divided aluminum, calcium sulfate, and magnesium sulfate. Water is also a part of the initial mixture. Some of it may come from water of hydration of the sulfates. If an anhydrous salt is used, then make up water may be required.
The optimum cured composition utilizes about equal weights of aluminum and calcium sulfate (calculated as hemihydrate), together with magnesium sulfate (on a molar basis, about one-half the amount of calcium sulfate), together with about 6 moles of water for each mole of magnesium sulfate.
The aluminum may be reduced to a relative scale weight as low as about 15% aluminum to about 85% calcium sulfate, calculated as anhydrous, and the percentages range from about 15%/85% to about 60%/40% is useful.
To this material, the magnesium sulfate is added, preferably as a nearly-saturated solution. The amount of water used depends on whether the salts are anhydrous or hydrated, and on the properties to be attained. Each pour is a one-shot effort, and depending on the proportions and hydration of the salts used, different amounts of water will be used. In fact, excess water will bleed out of the cast material. After curing, water cannot be added to the cast material. Thus, a certain amount of trial and error cannot be avoided.
The optimum mixture to be cast is as follows:
Aluminum metal, fully divided, and calcium sulfate, anhydrous, in equal proportions;
Magnesium sulfate, anhydrous, in one half of the mole ratio of the calcium sulfate;
Water, 6 moles per mole of the magnesium sulfate, plus water needed to allow for proper mechanical mixing.
The materials are mixed together and cast to a desired shape. The water is best supplied as a solvent for the magnesium sulfate. The mixture will then begin to cure. Surprisingly, there will be little or no exotherm. In fact, occasionally the curing reaction may be endothermic. The amount of water best to be used will be selected after a few experiments.
Whatever the selection, it results in minimal gas evolution, and minimal swelling. The heat output of the cured product is remarkably high, as is its density.
The burning rate can be controlled and the physical strength can be increased by addition of glycerin to the mixture. This is best added to the magnesium sulfate solution prior to mixing with the dry ingredients. It has been found that at 4.0% by weight of the cured mixture, glycerin will exude from the cast material during curing. Up to that point, glycerin will decrease the burning rate and increase the physical strength. About 1% is optimum.
There is no loss of weight or of physical properties after the curing, even when the product is stored at 225° F. for extended periods of time.
This product can be initiated by a suitable igniter. Because of its stable properties and of the high temperatures it generates, this pyrotechnic is usable in personnel-occupied working areas. For example, it is excellent for the quick destruction of files or documents.
This invention is not to be limited by the embodiments that are given by way of example, and not of limitation, but only in accordance with the scope of the appended claims.
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A pyrotechnic composition produced by mixing and permitting to cure a mixture of aluminum, calcium sulfate, magnesium sulfate, and water. Increased heat output and density and improved ignitability result, while exotherm during curing can substantially be eliminated.
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[0001] This application claims priority of provisional application 60/743,022 filed on Dec. 9, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of semiconductor fabrication tooling; more specifically, it relates to a method of improving the performance of charged particle beam fabrication tooling and apparatus for improving the performance of charged particle beam fabrication tooling.
BACKGROUND OF THE INVENTION
[0003] Ion implantation tools and other charged particle beam tools, are used extensively in the semiconductor industry. An ongoing problem is the deposition of foreign material on the wafers being processed. Existing methods of mitigating foreign material require extensive manual cleaning of tools after the loss of product to foreign material becomes excessive. Therefore, there is an ongoing need in the industry for a method of mitigating foreign material related product loss on wafers processed in ion implantation tools and other charged particle beam tools.
SUMMARY OF THE INVENTION
[0004] A first aspect of the present invention is a chamber having an interior surface; a pump port for evacuating the chamber; a substrate holder within the chamber; a charged particle beam within the chamber, the charged beam generated by a source and the charged particle beam striking the substrate; and one or more liners in contact with one or more different regions of the interior surface of the chamber, the liners preventing material generated by interaction of the charged beam and the substrate from coating the one or more different regions of the interior surface of the chamber.
[0005] A second aspect of the present invention is the first aspect, wherein each of the one or more liners is removable from the chamber.
[0006] A third aspect of the present invention is the first aspect, further including one or more access ports in the chamber, the one or more access ports having corresponding access port covers and wherein each of the one or more liners is removable through at least one of the one or more access ports.
[0007] A fourth aspect of the present invention is the first aspect, further including one or more access ports in the chamber, the one or more access ports having corresponding access port covers and wherein each of the one or more liners is removeably attached to one of the access port covers.
[0008] A fifth aspect of the present invention is the first aspect, wherein each of the one or more liners has a first surface and a opposite second surface, the first surface in contact with a region of the interior surface of the chamber and the second surface facing the charged particle beam.
[0009] A sixth aspect of the present invention is the fifth aspect, wherein the second surface of at least one of the one or more liners is textured.
[0010] A seventh aspect of the present invention is the first aspect, wherein each of the one or more liners has a surface contour designed to mate with a corresponding contour of a region of the interior surface of the chamber.
[0011] An eighth aspect of the present invention is the first aspect, wherein at least one of the one or more liners is compression fitted to a corresponding region of the interior surface of the chamber.
[0012] A ninth aspect of the present invention is the first aspect, wherein at least one of the one or more liners is removeably fastened to a corresponding region of the interior surface of the chamber.
[0013] A tenth aspect of the present invention is the first aspect, wherein at least one of the liners has a thickness of between about 0.05 inches and about 0.20 inches.
[0014] An eleventh aspect of the present invention is the first aspect, wherein the liners comprise aluminum or graphite.
[0015] A twelfth aspect of the present invention is the first aspect, wherein the liners are essentially free of iron, nickel, chrome, cobalt, molybdenum, beryllium, tungsten, titanium, tantalum, copper, magnesium, tin, indium, antimony, phosphorous, boron and arsenic.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0017] FIG. 1 a schematic top view of an exemplary ion implantation system according to a embodiment of the present invention;
[0018] FIG. 2 is a schematic top view of the analyzer chamber of FIG. 1 with removable liners in place;
[0019] FIG. 3 is a side view through line 2 B- 2 B of FIG. 2 of the analyzer liner assembly of FIG. 1 ;
[0020] FIG. 4 is an isometric view of the inner shield of FIG. 1 and FIG. 5 is an isometric view of the outer shield of FIG. 1 ;
[0021] FIG. 6 is a schematic top view of the pumping chamber of FIG. 1 with removable liners in place;
[0022] FIG. 8A is a side view and FIG. 8B is a front view of the first aperture liner of FIG. 6 ;
[0023] FIG. 9A is a side view and FIG. 9B is a front view of the second aperture liner of FIG. 6 ;
[0024] FIG. 10A is a top view, FIG. 10B is a front view and FIG. 10C is a flat projection view of the access port liner of FIG. 6 ;
[0025] FIG. 11A is a top view, FIG. 11B is a front view and FIG. 11C is a flat projection view of the pump port liner of FIG. 6 ;
[0026] FIG. 12 is a schematic top view of the resolving chamber of FIG. 1 with removable liners in place;
[0027] FIG. 13A is a side view and FIG. 13B is a front view of the third aperture liner of FIG. 12 r of FIG. 12 ;
[0028] FIG. 14A is a top view and FIG. 14B is a edge view of the first resolving chamber liner of FIG. 12 ;
[0029] FIG. 15A is a top view and FIG. 15B is a edge view of the second resolving chamber liner of FIG. 12 ; and
[0030] FIG. 16 is a schematic top view of an exemplary charge particle beam tool according to a embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The term “charged particle beam tool or system” is defined to be any tool that generates a beam of charged atoms or molecules or other particles and is capable of directing that charged species to the surface of or into the body of a wafer or substrate. Examples of charged particle beam systems include but is not limited to ion implantation tools, ion milling tools and electron beam tools and other plasmas tools such as reactive ion etch (RIE) tools. A wafer is one type of semiconductor substrate.
[0032] FIG. 1 a schematic side view of an exemplary ion implantation system according to an embodiment of the present invention. In FIG. 1 , an ion implantation system 100 includes a beam generation chamber 105 , an analyzer chamber 110 , a pumping chamber 115 , a resolving chamber 120 and a wafer chamber 125 connected to resolving chamber 120 by a flexible bellows 130 . The sidewalls of beam generation chamber 105 , analyzer chamber 110 , pumping chamber 115 , resolving chamber 120 and wafer chamber 125 are illustrated in sectional view, all other structures are illustrated in plan view. Beam generation chamber 105 includes an ion/plasma source 135 , an extractor 140 and a beam defining aperture 145 . Analyzer chamber 110 includes pole ends 150 of an electromagnet (not shown), an exit tube 155 an access port 160 and a access port cover 165 . Pumping chamber 115 includes a pumping port 170 , a deflector aperture 175 , an access port 180 and an access port cover 185 . Resolving chamber 120 includes a selectable aperture 190 , a beam sampler 195 , an electromagnetic aperture 200 , an electron shower aperture 205 , an electron shower tube 210 , a first access port 215 , a first access port cover 220 , a second access port 225 , a second access port cover 230 , a third access port 235 and a third access port cover 240 . Wafer chamber 125 includes a slideable and rotatable-stage 245 .
[0033] Beam generation chamber 105 , analyzer chamber 110 , pumping chamber 115 , resolving chamber 120 and a wafer chamber 125 are all connected together by vacuum tight seals and evacuated through pump port 170 . Additional pump ports may be provided, for example in beam generation chamber 105 . Wafer chamber 125 can be tilted relative to resolving chamber 120 . Beam generation chamber 105 , analyzer chamber 110 , pumping chamber 115 , resolving chamber 120 and a wafer chamber 125 are fabricated from solid or hollow cast blocks of aluminum that are bored out. Electromagnetic pole end 150 comprises iron. Electron shower tube 210 comprises graphite and is negatively charged.
[0034] In operation, an ion plasma is generated within ion source 135 and ions extracted from the ion source by extractor 140 to generate an ion beam that is projected along a beam path 250 by the electromagnet. After being passing through defining aperture 145 , the ion beam is passed through analyzer chamber 110 where only ions of a predetermined charge to mass ratio exit through exit aperture 155 . After passing through pumping chamber 135 , selectable aperture 190 , beam sampler 195 , electromagnetic aperture 200 , electron shower aperture 205 , and electron shower tube 210 , the ion beam strikes a substrate on stage 245 .
[0035] The exact locations and thicknesses of unwanted material layer formation is a function of the specific interior geometry and arrangement of components and the fabrication process being run, but in an example of one type of ion implantation tool these location occur in the analyzer, pumping and resolving chambers. These layers are formed by ions striking the walls and depositing there, materials (including photoresists) from the wafers vaporizing or being physically or chemically removed from the wafer as well as reaction of the ion/plasma beam with trace gases in the various chamber. When these layers become thick enough flakes break off and are swept down to the wafer chamber where they land on the wafers being processed. These flakes can have dimensions in the sub-micron regime.
[0036] There are several locations on the interior surfaces of analyzing chamber 110 , pumping chamber 115 and resolving chamber 120 that layers of material my build up on. These regions are discernable by buildup of layers of material after operation of implanter over extended periods of time. In analyzing chamber 110 , the top bottom and sidewalls in a region “A” partially defined by the dashed lines is a region of particularly heavy material deposition. In pumping chamber 115 , virtually all surfaces in a region “B” partially defined by the dashed lines is a region of particularly heavy material deposition. In resolving chamber 120 , lower surfaces in a region “C” partially defined by the dashed lines is a region of particularly heavy material deposition.
[0037] FIG. 2 is a schematic top view of the analyzer chamber 110 of FIG. 1 with removable liners in place. The sidewalls of analyzer chamber 110 are illustrated in sectional view, all other structures are illustrated in plan view. In FIG. 2 , an analyzer inner foreign material shield 260 and an analyzer outer foreign material shield 265 are removeably attached to the respective sidewalls 270 and 275 of analyzer chamber 110 . Removeably attached to access port cover 165 is an analyzer striker plate 280 . Removeably attached to outer foreign material shield 260 and striker plate 280 are an analyzer upper liner 285 A and an identical analyzer lower liner 285 B illustrated by heavy lines for clarity.
[0038] In one example, liners 2885 A and 285 B comprise aluminum. In one example liners 285 A and 285 B are between about 0.05 inches and about 0.20 inches thick. In one example, outer foreign material shield 260 , inner foreign material shield 265 and striker plate 280 are comprised of graphite or aluminum. Outer foreign material shield 260 , inner foreign material shield 265 and striker plate 280 roughened or textured by, for example, by machining, bead blasting, sand blasting, or etching. It is advantageous from a contamination point of view that outer foreign material shield 260 , inner foreign material shield 265 , striker plate 280 and liners 285 A and 285 B not contain significant amounts (are essentially free) of iron, nickel, chrome, cobalt, molybdenum, beryllium, tungsten, titanium, tantalum, copper, magnesium, tin, indium, antimony, phosphorous, boron or arsenic. A feature of shields 185 A and 285 B is that they do not overlap electromagnetic pole end 150 so as not to interfere with the magnetic flux lines of the electromagnet.
[0039] FIG. 3 is a side view through line 2 B- 2 B of FIG. 2 of an 290 analyzer liner assembly of FIG. 1 . Analyzing chamber 110 (see FIG. 2 ) is rectangular in cross-section so analyzer assembly 290 comprising, striker plate 280 and liners 285 A and 285 B just fits in between a top wall 295 A and a bottom wall 295 B of analyzing chamber 110 . Striker plate 280 has a height “H 1 ” Inside surfaces 300 A and 300 B of respective liners 285 A and 285 B are advantageously roughened or textured by, for example, by machining, bead blasting, sand blasting, or etching.
[0040] FIG. 4 is an isometric view of the inner shield of FIG. 1 and FIG. 5 is an isometric view of the outer shield of FIG. 1 . In FIG. 4 , a region 305 of inner shield 260 has a height “H 1 ” and in FIG. 5 , a region 310 of inner shield 260 also has a height “H 1 .”
[0041] Returning to FIG. 2 , it can be seen that inner and outer shields 260 and 265 and striker plate 280 have a first function of collecting ionized species that do not have the required mass/charge ratio and as a consequence get coated with a layer of unwanted material. Thus inner and outer shields 260 and 265 and striker plate 280 serve a second function of preventing portions of the top and bottom walls of analyzer chamber from becoming coated with unwanted material. Liners 285 A and 285 B also become coated with unwanted layers of material. By removing access port cover 160 , liners 285 A and 285 B as well as outer foreign material shield 260 , inner foreign material shield 265 , striker plate 280 may be periodically removed for cleaning, clean and then reinstalled or a previously cleaned replacement set of liners, shields and striker plate installed in the machine while the removed liners and shields are cleaned. In either case tool down time is significantly less than cleaning the chamber surfaces themselves and the cleaning is more thorough.
[0042] FIG. 6 is a schematic top view of pumping chamber 115 of FIG. 1 with removable liners in place. The sidewalls of pumping chamber 115 are illustrated in sectional view, all other structures are illustrated in plan view. In FIG. 6 , a first aperture liner 315 , a second aperture liner 320 , a pump chamber liner 325 , a pump port liner 330 and an access port liner 335 (illustrated by heavy lines for clarity) are removeably positioned in contact with interior surfaces of pumping chamber 115 . L liners 315 , 320 , 325 , 330 and 335 are removed and installed through access port 180 . By removing access port cover 185 , liners 315 , 320 , 325 , 330 and 335 may be periodically removed for cleaning, clean and then reinstalled or a previously cleaned replacement set of liners installed in the machine while the removed liners are cleaned. In either case tool down time is significantly less than cleaning the chamber surfaces themselves and the cleaning is more thorough.
[0043] While gaps are illustrated between liners 315 , 320 , 325 , 330 and 335 , these gaps are advantageously designed to be zero (liners touching) or as close to zero as practical without interfering with easy install and removal of the liners.
[0044] In one example, liners 315 , 320 , 325 , 330 and 335 comprise aluminum. In one example liners 315 , 320 , 325 , 330 and 335 are between about 0.05 inches and about 0.20 inches thick. Liners 315 , 320 , 325 , 330 and 335 are roughened or textured by, for example, by machining, bead blasting, sand blasting, or etching blasting. It is advantageous from a contamination point of view that liners 315 , 320 , 325 , 330 and 335 not contain significant amounts of iron, nickel, chrome, cobalt, molybdenum, beryllium, tungsten, titanium, tantalum, copper, magnesium, tin, indium, antimony, phosphorous, boron or arsenic.
[0045] FIG. 7A is a top view and FIG. 7B is a side view of pumping chamber liner 315 of FIG. 6 . Pumping chamber liner 315 is comprised of two identical liners, a lower liner 315 A and an upper liner 315 B, which are curved along beam path 250 to fit the main bore of pumping chamber 115 (see FIG. 6 ) along the beam path direction. Notches 340 A and 340 B are curved to match the bore of an access port bore and a pump bore respectively.
[0046] FIG. 8A is a side view and FIG. 8B is a front view of first aperture liner 320 of FIG. 6 . First aperture liner 320 is comprised of two identical liners, a lower liner 320 A and an upper liner 320 B with corresponding bores 345 A and 345 B centered along beam path 250 .
[0047] FIG. 9A is a side view and FIG. 9B is a front view of second aperture liner 325 of FIG. 6 . Second aperture liner 325 includes a circular bore 350 centered along beam path 250 .
[0048] FIG. 10A is a top view, FIG. 10B is a front view and FIG. 10C is a flat projection view of pump port liner 330 of FIG. 6 . In FIG. 10C , an outside edge 355 A will face pump port 170 (see FIG. 6 ) and an inside edge 355 B will face the interior of pumping chamber 115 (see FIG. 6 ). In FIG. 10B , the curves of inside edge 355 B are shaped to match intersection of the pump port bore and the main bore of pumping chamber 115 (see FIG. 6 ) when rolled to form a ring having a gap 360 where edges 365 A and 365 B are proximate to each other. Gap 360 allows access port liner to “spring” or compression fit inside pumping chamber 115 (see FIG. 6 ).
[0049] FIG. 11A is a top view, FIG. 11B is a front view and FIG. 11C is a flat projection view of access port liner 335 of FIG. 6 . In FIG. 11C , an outside edge 370 A will face access port 170 (see FIG. 6 ) and an inside edge 370 B will face the interior of pumping chamber 115 (see FIG. 6 ). In FIG. 11B , the curves of inside edge 370 B are shaped to match intersection of the access port bore and the main bore of pumping chamber 115 (see FIG. 6 ) when rolled to form a ring having a gap 375 where edges 380 A and 380 B are proximate to each other. Gap 375 allows pump port liner to “spring” fit inside pumping chamber 115 (see FIG. 6 ).
[0050] Returning to FIG. 6 , liners 320 and 325 are held in place by liner 315 which in turn is held in place by liners 330 and 335 . Thus liners 315 , 320 , 325 , 330 and 335 are can be easily removed for cleaning and clean liners easily installed.
[0051] FIG. 12 is a schematic top view of resolving chamber 120 of FIG. 1 with removable liners in place. The sidewalls of resolving chamber 120 are illustrated in sectional view, all other structures are illustrated in plan view. In FIG. 12 , a third aperture liner 385 , a first lower pump chamber liner 390 , and a second lower pump chamber liner 395 are removeably positioned in contact with interior surfaces of resolving chamber 120 . Liners 385 , 390 and 395 are installed and removed through access port 215 . By removing access port cover 220 , liners 385 , 390 and 395 may be periodically removed for cleaning, clean and then reinstalled or a previously cleaned replacement set of liners installed in the machine while the removed liners are cleaned. In either case tool down time is significantly less than cleaning the chamber surfaces themselves and the cleaning is more thorough.
[0052] While gaps are illustrated between liners 385 , 390 and 395 , these gaps are advantageously designed to be zero (liners just touching) or as close to zero as practical without interfering with easy install and removal of the liners.
[0053] In one example, liners 385 , 390 and 395 comprise aluminum. In one example liners 385 , 390 and 395 are between about 0.05 inches and about 0.20 inches thick. Liners 385 , 390 and 395 are roughened or textured by, for example, by machining, bead blasting, sand blasting, or etching. It is advantageous from a contamination point of view that liners 385 , 390 and 395 5 not contain significant amounts of iron, nickel, chrome, cobalt, molybdenum, beryllium, tungsten, titanium, tantalum, copper, magnesium, tin, indium, antimony, phosphorous, boron or arsenic.
[0054] FIG. 13A is a side view and FIG. 13B is a front view of third aperture liner 385 of FIG. 12 . Third aperture liner 385 includes a circular bore 400 centered along beam path 250 . Also illustrated in FIG. 13A , (in cross-section) is second aperture liner 325 and a portion of resolving chamber 120 . It can be seen that second aperture liner 325 fits into bore 400 to prevent foreign material from being trapped between third aperture liner 385 and walls of resolving chamber 120 .
[0055] FIG. 14A is a top view and FIG. 14B is a edge view of first resolving chamber liner 390 of FIG. 12 . Liner 390 is curved along beam path 250 to fit the main bore of resolving chamber 120 (see FIG. 12 ) along the beam path direction. A key 405 is provided on one side of liner 390 . Liner 390 is positioned on the bottom surfaces of resolving chamber 120 under selectable aperture 190 , and beam sampler 195 (see FIG. 12 ).
[0056] FIG. 15A is a top view and FIG. 15B is a edge view of second resolving chamber liner 395 of FIG. 12 . Liner 395 is curved along beam path 250 to fit the main bore of resolving chamber 120 (see FIG. 12 ) along the beam path direction. A keyhole 410 is provided on one side of liner 395 . Liner 395 is positioned on the bottom surfaces of resolving chamber 120 under selectable aperture 190 , and beam sampler 195 (see FIG. 12 ). Key 405 of liner 390 (see FIG. 14A ) engages keyhole 410 of liner 395 when the liners are in place.
[0057] Returning to FIG. 12 , there is no liner under electromagnetic aperture 200 and electron shower aperture 205 or on the upper surfaces of resolving chamber 120 , because buildup of material in these locations is not significant. There are two options designing liners. The first option is to place liners over as many interior surfaces of the charged particle beam tools as possible without interfering with the operation of the tool. The second option is to place liners over only those interior surfaces of the charged particle beam tools where significant material buildup is expected (for example, cooler surfaces) or has been found to occur.
[0058] FIG. 16 is a schematic top view of an exemplary charged particle beam tool 420 according to a embodiment of the present invention. In FIG. 16 , charged particle beam system 420 comprises a source chamber 425 , a pumping chamber 430 , a beam alignment/defection chamber 435 and a target chamber 440 . The arrangement of chambers can vary from tool to tool and some chambers may be combined into a single chamber. Pumping chamber 430 includes replaceable aperture liners 445 A and 445 B and replaceable pump chamber liners 450 A, 450 B and 450 C which may be installed and removed through an access port 455 . Beam alignment/defection chamber 435 includes replaceable aperture liners 460 A and 460 B and replaceable pump chamber liners 465 A, 465 B, 465 C and 465 D which may be installed and removed through an access ports 470 A and 470 B.
[0059] A charged particle beam 475 is generated in source chamber 420 by a beam source 480 , passes through pump chamber 430 , beam alignment/defection 435 and strikes a target 485 in target chamber 440 . In one example, beam 475 comprises a species selected from the group consisting of phosphorus containing species ions, boron containing species ions, arsenic containing species ions, germanium containing species ions, carbon containing species ions, nitrogen containing species ions, helium ions, electrons, protons, or combinations thereof.
[0060] All liners 445 A, 445 B, 450 A, 450 B. 450 C, 460 A, 460 B, 465 A, 465 B, 465 C and 465 D are formed of material selected to not contain chemical elements detrimental to the operation of or process being performed by tool 420 . Liners 445 A, 445 B, 450 A, 450 B. 450 C, 460 A, 460 B, 465 A, 465 B, 465 C and 465 D may be held in place by compression, fasteners or gravity. There may be more or less liners than the number shown in FIG. 16 . The surfaces of liners 445 A, 445 B, 450 A, 450 B. 450 C, 460 A, 460 B, 465 A, 465 B, 465 C and 465 D away from the inside surfaces of the various chambers may be advantageously roughened or textured by machining, bead blasting, sand blasting, or etching. Liners 445 A, 445 B, 450 A, 450 B. 450 C, 460 A, 460 B, 465 A, 465 B, 465 C and 465 D may be cleanable or disposable.
[0061] Thus, the embodiments of the present invention provide an apparatus and a method of mitigating foreign material related product loss on wafers processed in ion implantation tools and other charged particle beam tools.
[0062] The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention.
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An improved performance charged beam apparatus and method of improving the performance of charged beam apparatus. The apparatus including: a chamber having an interior surface; a pump port for evacuating the chamber; a substrate holder within the chamber; a charged particle beam within the chamber, the charged beam generated by a source and the charged particle beam striking the substrate; and one or more liners in contact with one or more different regions of the interior surface of the chamber, the liners preventing material generated by interaction of the charged beam and the substrate from coating the one or more different regions of the interior surface of the chamber.
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This application claims priority to U.S. Provisional Application No. 60/626,912, filed on Nov. 12, 2004, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to structural supports. In particular, this invention relates to structural supports for, for example, wind turbines, or the like.
2. Description of Related Art
Conventional offshore platforms have deck legs that are vertical or are battered outward as they extend downwards. The conventional arrangement provides structurally efficient support for the deck but the associated dimensions of the platform at the water surface result in increased expense for the platform.
Wind turbines have traditionally been supported on mono-piles when placed offshore. However, recently, efforts have taken place to position wind turbines in deeper water (approximately six to seven or more miles offshore) in part to increase the aesthetics of the view from the shoreline. However, with the movement of wind turbines further offshore, the employment of mono-piles as the base on which wind turbines are placed has become less cost effective.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a wind turbine in combination with a structure support that provides a sturdy and cost effective support even in deep waters. This combination includes a wind turbine comprising a base and a blade mechanism. The structure support further includes at least three elements configured in a substantially teepee shaped configuration, where the at least three elements encompassing a substantially vertical member. A first end of the at least three elements is capable of being affixed to a structure and a second end of the at least three elements adapted to be in contact with a surface. The at least three elements intersect between the first end and the second end. The combination also includes a mounting flange connecting the structure support to the wind turbine.
In accordance with a further embodiment of the present invention the at least three elements intersect above a waterline or at a waterline.
In accordance with another exemplary aspect of the present invention, a method of constructing a wind turbine on a structure support is disclosed. At least three legs are provided in a teepee configuration. A first end of the first three legs are placed on a mounting surface and a deck is affixed to a second end of the at least three legs. A wind turbine mounting flange is affixed to the structure and a base is affixed to the mounting frame and turbine element is affixed to the base. A blade mechanism affixed to the turbine element.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention will be described in detail, with reference to the following figures, wherein:
FIG. 1 is a view in side elevation of an offshore platform according to the present invention;
FIG. 2 is a view in front elevation of the offshore platform according to the present invention;
FIG. 3 is a perspective view of the offshore platform with a wind turbine placed on a deck of the platform according to the present invention;
FIG. 4 is a side perspective view of the offshore platform with a wind turbine placed on the deck of the platform according to the present invention;
FIGS. 5–18 illustrate an exemplary method of assembling the offshore structure and wind turbine according to this invention;
FIGS. 19–21 illustrate another exemplary method of assembling the offshore structure and wind turbine according to this invention;
FIGS. 22 and 23 illustrate another exemplary offshore structure support foundation according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
The exemplary embodiments of this invention will be described in relation to a support structure, such as an oil and gas platform or a platform for the placement of additional structures, supported by three piles and a central vertical member, such as drill pipe. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures and devices that may be shown in block diagram form or otherwise summarized. For the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It should be appreciated that the present invention may be practiced in a variety of ways beyond these specific details. For example, the systems and methods of this invention can be generally expanded and applied to support any type of structure. Furthermore, while exemplary distances and scales are shown in the figures, it is to be appreciated the systems and methods of this invention can be varied to fit any particular implementation.
FIGS. 1 and 2 show an inward battered guide offshore platform indicated generally at 10 in which battered bracing piles 12 a , 12 c and 12 e are arranged so as to minimize platform dimensions at the water surface 14 while maximizing the spacing of the piles as they extend upward from the water surface so that loads from a deck 16 at the top of the piles are transferred directly to the piling. For example, if three or more piles are employed to create the structure, they could be spaced apart 120 degrees. Piles 12 b and 12 d are conductor piles used in oil and gas platforms.
The platform includes a pile guide structure 18 which fits over and is connected to a central vertical member 20 to receive the piles 12 a , 12 c and 12 e at the water surface. The piles extend angularly through guides 22 of the pile guide structure in such a manner that the distance between piles is minimized at the water surface, but the distances between angled piles is maximized both at the ends supporting the deck 16 as well as at the opposed end buried below the mudline 24 . The pile guide connects the piles to act in unison to restrain lateral movement of the entire offshore platform 10 including the central vertical member 20 .
The pile guide 18 also supports appurtenances such as ladders, boat landings, stairs, or the like, so that they can be installed in the field as a unit, thereby, for example, reducing installation expense for the platform. The legs 26 of the deck structure are connected to the tops of the piles. The increased pile spacing at the pile tops provides, for example, more structurally efficient support for the deck, reduced structural vibration periods for the platform and increased resistance to the rotation that results if the deck mass is eccentric to the central vertical member 20 than if the deck is supported by the central member. All field connections can be made above the water surface where structural integrity of the connections can be more easily verified than if the connections were made below the water surface.
Once the piles 12 a , 12 c and 12 e are in place, and the legs 26 and deck 16 are placed on the piles then, as shown in FIGS. 3 and 4 , a wind turbine 100 can be installed. FIGS. 3 and 4 show two different perspective views of the wind turbine 100 when installed on the deck 16 of platform 10 . The wind turbine 100 comprises: a base 125 including a lower section 110 and an upper section 120 ; a turbine element 130 ; and a blade mechanism 150 that comprises a rotor star 152 and individual blades 154 . While the wind turbine described herein comprises a base 125 and three individual blades 154 , other types of wind turbines can also be employed with the structure of FIG. 1 , for example, in the manner described above. For example, a wind turbine with a single base part or having a multitude of parts that make up the base can be employed. Moreover, the wind turbine can also include more or a lesser number of blades as well as different types of blade mechanisms.
FIGS. 5–19 illustrate an exemplary method for assembling a the platform 10 and wind turbine 100 in accordance with an exemplary embodiment of this invention with, for example, a barge boat, around a substantially vertical member 20 such as SSC 50 (Self Sustaining Caisson). In this exemplary embodiment, the SSC 50 has been installed by an oil and gas drilling rig, such as a rig drilling an exploration well. The vertical member 20 (SSC 50 ) can either be installed when the platform is assembled or alternately, the remaining parts of the platform can be assembled around a previously erected vertical member. This enables the platform to be advantageously built on existing already used oil drill caissons or mono-piles to support oil and gas wells.
In FIG. 5 , the position and orientation of the legs are determined and a lift boat 55 anchored and jacked-up relative to the installation point of the SSC 50 . Next, as illustrated in FIG. 6 , the guide structure 18 is unloaded from the barge 60 . Then, as illustrated in FIG. 7 , the piles 12 a , 12 c and 12 e , are unloaded, placed in the guide structure, and in FIG. 8 , installed via the guide structure into, for example, the ocean floor with the aid of a pile driving hammer (e.g., a hydraulic hammer). As can be seen from this illustration, the piles 12 a , 12 c and 12 e intersect at a point just above the water line. This allows, for example, the piles and all associated connections to be made above water. However, one would also understand that the intersection point could also reside at or below the waterline.
In FIG. 9 , the barge 60 is relocated and the deck 16 is unloaded. In FIG. 10 the deck 16 including legs 26 are installed on the piles. In accordance with an exemplary embodiment of the invention, the deck can be modified to employ and support a wind turbine 100 . Specifically to support the turbine a mounted flange can be built on the deck 16 . The flange can be attached to the deck via bolting, grouting or welding. Although as illustrated in FIG. 10 , the mounting flange 200 is shown being attached to the deck prior to placement on the legs 26 , the mounting flange 200 could be installed after the deck has been installed. FIGS. 11 and 12 provide a side view and top view of the deck 16 and mounting flange 200 when installed.
As illustrated in FIG. 13 , once the mounting flange 200 is placed and set onto the deck 16 , the tower lower section 110 is unloaded from the lift boat 55 and installed onto the mounting frame 200 . Next, as illustrated in FIG. 14 , the upper section 120 of the tower is unloaded and installed onto the tower lower section 110 . Once the upper section 120 of the base has been installed, as illustrated in FIGS. 15 and 16 , the turbine 130 is removed from the lift boat and attached to the upper section 120 of the tower.
As the tower lower section 110 , tower upper section 120 and turbine 130 are installed, the blade mechanism 150 is readied for installation. The installation of this part of the wind turbine 100 can be performed in a plurality of different ways, in accordance with the present invention, as discussed below.
In accordance with one exemplary embodiment of the present invention, as illustrated in FIGS. 17 and 18 , the complete, blade mechanism already fully assembled is unloaded from the lift boat 55 and attached to the turbine 130 .
Alternatively, as illustrated in FIGS. 19–21 , the blade mechanism does not need to be fully assembled prior to attachment to the turbine 130 . This is advantageous for several different reasons. The blade mechanism, if fully assembled would require extra stowage area for transport to the assembly area. If, for example, only two of the blades were assembled, then to the rotor star, then the required space needed to transport the blade mechanism is reduced. Furthermore, if the remaining blade is not attached to the rotor star until it is already attached to the turbine, additional monetary savings can be achieved since the crane employed to attach the blade can be smaller. In FIG. 19 , the blade mechanism having the two blades attached to the rotor star is raised (via a crane) and attached to the turbine (as illustrated in FIG. 20 ). Finally, in FIG. 21 , the remaining blade 158 is attached to the rotor star. Again, FIGS. 3 and 4 provide a side views of the assembled wind turbine on the offshore structure support 10 .
In accordance with another exemplary aspect of the present invention, a deck and associated mounting flange 300 is provided to receive a wind turbine, as illustrated in FIGS. 22 and 23 . Specifically, the mounting flange 300 includes a body 310 and an elliptical (or spherical) head 320 extending below deck 16 . The body 310 is circular and includes a deck end 312 and a head end 314 portion. A wind turbine 100 is able to be attached to the foundation body 310 at the deck end 312 of the foundation body, via bolting, for example. The foundation body 310 is also able to receive legs 26 that are connected to the batter bracing piles 12 a , 12 c and 12 e . Note that four piles are illustrated in FIG. 22 .
The elliptical (or spherical) head 320 is attached to the foundation body 310 at its deck leg connection end and enables the turbine foundation 300 a more fatigue resistant connection at the deck leg. For this same reason, as illustrated in FIG. 22 , the ends of the legs 26 also employ a curved surface. By making the intersection between the foundation body 310 and the elliptical (or spherical) head 320 as well as foundation body 310 and the elliptical shape of the legs 26 , a continuously curved intersection is provide and a sharp corner is avoided. As a result, hot spot stresses are reduced on the joints.
Additionally in accordance with the present embodiment discussed with regard to FIGS. 22 and 23 , the deck 16 includes structural support elements extending from the deck end of the turbine foundation to the edge of the deck 16 . While the deck 16 in the embodiment shown in FIG. 23 is illustrated as octagonal, one could understand that the deck could be made to be other shapes also, (e.g., hexagonal, rectangular, circular, or the like).
In accordance with another aspect of the present invention, the natural period of the offshore support structure can be adjusted to avoid the excessive vibration of the wind turbine while operating that would result if the natural period of the support structure was too close to matching the rotational period of the turbine. This tuning of the natural period can be accomplished by changing the size of the components of the support structure, by increasing or decreasing the batter of the piles, adjusting the spacing of the piles and/or by raising or lowering the elevations where the piles are laterally supported. The extent and combination of tuning measures required vary depending on the design and operational characteristics of the wind turbine and the water depth, meteorological and oceanographic conditions and soil characteristics at the location.
For example, a typical three blade wind turbine is controlled by adjusting blade pitch to make one rotation about every 4.5 seconds in most wind conditions. Therefore, for a typical wind turbine one of the three blades would than pass the wind turbine support tower every 1.5 seconds. To avoid the wind turbine rotational periods and limit potential for destructive resonance, frequency forbidden zones are established for the natural frequency of the entire support structure. For a typical wind turbine the forbidden natural frequency zones could be 0.18 Hz to 0.28 Hz and 0.50 Hz to 0.80 Hz. Likewise, the target natural frequency would be 0.30 Hz to 0.33 Hz and higher order natural frequencies should be above 0.80 Hz. If computed eignfrequencies are in a forbidden zone tuning will be necessary. Tuning can then be accomplished in the manner discussed above.
It is, therefore, apparent that there has been provided, in accordance with the present invention, a support and method for assembling a wind turbine for placement on an offshore support structure. While this invention has been described in conjunction with a number of illustrative embodiments, it is evident that many alternatives, modifications, and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, the disclosure is intended to embrace all such alternatives, modifications, equivalents and variations that are within in the spirit and scope of this invention.
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A pile based braced caisson structural support device includes a number of legs in is used to support a wind turbine. The wind turbine includes a base, a turbine generator and a blade mechanism. The legs are configured in a teepee type configuration such that the footprint of the base is larger than the footprint of the opposing end. This structural support can be used as a base for an offshore platform in that the support reduces the lateral forces on the support caused by wave action.
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[0001] This application claims the benefit of Korean Patent Application No. 10-2008-0026348, filed on Mar. 21, 2008, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an air-conditioner and a method for charging a refrigerant of an air-conditioner, and more particularly, to an air-conditioner and a refrigerant charging method of an air-conditioner capable of automatically charging a refrigerant when the amount of refrigerant charged in the air-conditioner is not sufficient.
[0004] 2. Description of the Related Art
[0005] As for a multi-air-conditioner, if a refrigerant flowing in the multi-air-conditioner is more than or less than a fixed quantity, a system performance is degraded, and worse, the multi-air-conditioner may be damaged. In the related art, a manometer (or a pressure gauge) is installed at a particular position of the air-conditioner to determine overs and shorts of the amount of refrigerant based on the pressure of the refrigerant detected by the monometer. However, only an expert or a technician of the air-conditioner is able to determine the overs and shorts of the refrigerant by using such method, so using of the method is inconvenient for general users. In addition, even the technician has no choice but to determine the overs and shorts of the refrigerant indirectly, lowering the reliability of the results of the determination of the overs and shorts of the refrigerant. Thus, in most cases, the refrigerant in the air-conditioner is wholly removed out, and then, the air-conditioner is charged with a new refrigerant. Such unnecessary re-charging of the air-conditioner with the new refrigerant takes much time and incurs much cost. In addition, the operation of the air-conditioner should be stopped for the process of re-charging the refrigerant, which causes user inconvenience.
SUMMARY OF THE INVENTION
[0006] Thus, an object of the present invention is to provide an air-conditioner and a method for charging a refrigerant of the air-conditioner capable of automatically charging a refrigerant if the refrigerant charged in the air-conditioner is insufficient.
[0007] To achieve the above object, there is provided a method for charging a refrigerant of an air-conditioner, including: receiving a request for performing a refrigerant amount determining mode to determine whether or not a refrigerant charged in the air-conditioner is proper; if it is determined that the refrigerant amount determining mode can be started while the air-conditioner is operated in a first operation mode, changing the air-conditioner to a second operation mode; determining whether or not the refrigerant charged in the air-conditioner is proper while the air-conditioner is operated in the second operation mode; and if the refrigerant charged in the air-conditioner is not sufficient, charging a certain amount of refrigerant to the air-conditioner.
[0008] The first operation mode may be a mode for operating the air-conditioner in a blowing mode, and after the air-conditioner is operated in the blowing mode, if an indoor temperature and an outdoor temperature are within a pre-set temperature range, respectively, in a state that pre-set condition is met, it may be determined that the refrigerant amount determining mode can be started. In this case, the pre-set condition may be a condition that an operation time (time period or duration) of the blowing mode is a pre-set time or longer.
[0009] The air-conditioner may be a multi-air-conditioner including a plurality of indoor units, and the second operation mode may be an all-room cooling operation mode in which the plurality of indoor units are operated for cooling.
[0010] The method may further include: determining whether or not the air-conditioner is stable after the air-conditioner is changed to the second operation mode. In determining whether or not the air-conditioner is stable, if a plurality of operation variables of the air-conditioner are within pre-set ranges, it may be determined that the air-conditioner is stable.
[0011] The air-conditioner may include an outdoor heat exchanger and an indoor heat exchanger that heat-exchange a refrigerant; and a liquid pipe (connection pipe) that connects the outdoor heat exchanger and the indoor heat exchanger, and whether or not the refrigerant charged in the air-conditioner is proper may be determined based on the temperature of the liquid pipe. The air-conditioner may further include a liquid pipe temperature sensor installed at the liquid pipe, and if the temperature of the liquid pipe detected by the liquid pipe temperature sensor is higher than a pre-set liquid pipe temperature, it may be determined that the refrigerant charged in the air-conditioner is insufficient.
[0012] The method may further include: if the refrigerant charged in the air-conditioner is proper after the certain amount of refrigerant is charged in the air-conditioner, preventing the refrigerant from being introduced any further.
[0013] The air-conditioner and the refrigerant charging method of the air-conditioner according to the present invention are advantageous in that when the refrigerant amount determining mode is requested to be performed, whether or not the refrigerant amount in the air-conditioner is proper is automatically determined and a shortage amount of refrigerant can be charged. Thus, a user can easily check whether or not the refrigerant charged in the air-conditioner is sufficient or insufficient, and if the refrigerant is not sufficient, the user can automatically charge the refrigerant without having to entirely remove the refrigerant from the air-conditioner, thus increasing the user convenience and reducing time and costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0015] In the drawings:
[0016] FIG. 1 shows a configuration of a multi-air-conditioner applied for a refrigerator charging method of an air-conditioner according to an embodiment of the present invention.
[0017] FIG. 2 illustrates a flow of a refrigerant when the air-conditioner is operated for cooling all the rooms.
[0018] FIG. 3 illustrates a flow of a refrigerant when the air-conditioner is operated for heating all the rooms.
[0019] FIG. 4 is a flow chart illustrating a control flow of the refrigerant charging method of the air-conditioner according to an embodiment of the present invention.
[0020] FIG. 5 shows a configuration of an outdoor unit of the air-conditioner illustrated in FIG. 1 and a refrigerant charging device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Air-conditioners include a general air-conditioner that performs a cooling operation, a heater that performs a heating operation, a general heat pump type air-conditioner that performs both cooling and heating operations, and a multi-air-conditioner that cools/heats a plurality of indoor spaces. Hereinafter, the multi-air-conditioner will now be described in detail as an embodiment of the air-conditioner.
[0022] FIG. 1 shows the configuration of a multi-air-conditioner (referred to as an ‘air-conditioner’, hereinafter) 100 applied for a refrigerator charging method of an air-conditioner according to an embodiment of the present invention. With reference to FIG. 1 , the air-conditioner includes an outdoor unit (OU) and indoor units (IUs). The OU includes a compressor 110 , an outdoor heat exchanger 140 , an outdoor expansion valve 132 , a supercooler 180 , and a controller (not shown). Although the air-conditioner 100 is shown to have a single OU, but the present invention is not limited thereto and the air-conditioner 100 may include a plurality of OUs.
[0023] The IUs include an indoor heat exchanger 120 , an indoor air blower 125 , and an indoor expansion valve 131 , respectively. The indoor heat exchanger 120 acts as an evaporator for a cooling operation and acts as a condenser for a heating operation. The outdoor heat exchanger 140 acts as a condenser for a cooling operation and acts as an evaporator for a heating operation.
[0024] The compressor 110 compresses an introduced low temperature low pressure refrigerant into a high temperature high pressure refrigerant. The compressor 110 may have various structures, and an inverter type compressor may be employed. A flow sensor 191 , a discharge temperature sensor 171 , and a discharge pressure sensor 151 are installed at a discharge pipe 161 of the compressor 110 . A suction temperature sensor 175 and a suction pressure sensor 154 are installed at a suction pipe (or intake pipe) 162 of the compressor, and a frequency sensor 188 is installed to measure the frequency of the compressor 110 . The OU is shown to have one compressor 110 , but without being limited thereto, the present invention may include a plurality of compressors. An accumulator 187 s installed at the suction pipe 162 of the compressor 110 to prevent a liquid refrigerant from being introduced into the compressor 110 .
[0025] A four-way valve 160 , a flow path switching valve for switching the cooling and heating, guides the refrigerant compressed by the compressor 110 to the outdoor heat exchanger 140 for the cooling operation and guides the compressed refrigerant to the indoor heat exchangers 120 for the heating operation.
[0026] The indoor heat exchangers 120 are disposed in the respective indoor spaces. In order to measure the temperature of the indoor spaces, indoor temperature sensors 176 are installed. The indoor expansion valves 131 are units for throttling the introduced refrigerant when the cooling operation is performed. The indoor expansion valves 131 are installed at indoor inlet pipes 163 of the IUs. Various types of indoor expansion vales 131 may be used, and an electronic expansion valve may be used for user convenience. Indoor inlet pipe temperature sensors 173 are installed at the indoor inlet pipes 163 . Specifically, the indoor inlet pipe temperature sensors 173 are installed between the indoor heat exchangers 120 and the indoor expansion valves 131 , respectively. In addition, indoor outlet pipe temperature sensors 172 and indoor pressure sensors 152 are installed at the indoor outlet pipes 164 .
[0027] The outdoor heat exchanger 140 is disposed in an outer space. An outdoor temperature sensor 177 is installed to measure the temperature of an outdoor space. A liquid pipe temperature sensor 174 is installed at a liquid pipe 165 that connects the outdoor expansion valve 132 and the IUs. The outdoor expansion valve 132 , which throttles the refrigerant introduced when the heating operation is performed, is installed at the liquid pipe 165 . A first bypass pipe 167 for allowing the refrigerant to bypass the outdoor expansion valve 132 is installed at an inlet pipe 166 connecting the liquid pipe 165 and the outdoor heat exchanger 140 , and a check valve 133 is installed at the first bypass pipe 167 . The check valve 133 allows the refrigerant to flow from the outdoor heat exchanger to the IUs when the cooling operation is performed, and prevents the refrigerant from flowing when the heating operation is performed. An outdoor pressure sensor 153 is installed at the inlet pipe 166 .
[0028] The supercooler 180 includes a supercooling heat exchanger 184 , a second bypass pipe 181 , a supercooling expansion valve 182 , and a discharge pipe 185 . The supercooling heat exchanger 184 is installed at the inlet pipe 166 . During the cooling operation, the second bypass pipe 181 bypasses the refrigerant discharged from the supercooling heat exchanger 184 to allow the refrigerant to be introduced into the supercooling heat exchanger 184 . The supercooling expansion valve 182 is disposed at the second bypass pipe 181 , throttles the liquid refrigerant introduced into the second bypass pipe 181 to lower the pressure and temperature of the refrigerant, so as for the refrigerant to be introduced into the supercooling heat exchanger 184 . Accordingly, during the cooling operation, the high temperature condensed refrigerant which has passed through the outdoor heat exchanger 140 is supercooled by being heat-exchanged with the low temperature refrigerant which has been introduced through the second bypass pipe 181 , and then flow to the IUs. The bypass refrigerant is heat-exchanged at the supercooling heat exchanger 184 and then introduced into the accumulator 187 through the discharge pipe 185 . A bypass flowmeter 183 is installed at the second bypass pipe 181 to measure the amount of flow bypassed through the second bypass pipe 181 .
[0029] FIG. 2 shows a flow of the refrigerant when the air-conditioner 100 performs an all-room cooling operation. With reference to FIG. 2 , the high temperature high pressure gaseous refrigerant discharged from the compressor 110 is introduced into the outdoor heat exchanger 140 via the four-way valve 160 , and then condensed in the outdoor heat exchanger. The outdoor expansion valve 132 is completely open. The indoor expansion valves 131 of the IUs are open at an opening degree which has been set for refrigerant throttling. Thus, the refrigerant discharged from the outdoor heat exchanger 140 is first introduced into the supercooler 180 through the outdoor expansion valve 132 and the check valve 133 . The discharged refrigerant is supercooled by the supercooler 180 and then introduced into the IUs.
[0030] The refrigerant introduced into the IUs is throttled at the indoor expansion valve 131 and then evaporated at the indoor heat exchanger 120 . The evaporated refrigerant is introduced into the suction pipe 162 of the compressor 110 through the four-way valve 160 and the accumulator 187 . At this time, the indoor air blowers 125 are operated.
[0031] FIG. 3 shows the flow of the refrigerant when the air-conditioner 100 performs all-room heating operation. With reference to FIG. 3 , the high temperature high pressure gaseous refrigerant discharged from the compressor 110 is introduced into the IUs through the four-way valve 160 . The indoor expansion valves 131 of the IUs are completely open. In addition, the supercooling expansion valve 192 is closed. Accordingly, the refrigerant introduced from the IUs is throttled at the outdoor expansion valve 132 and then evaporated from the outdoor heat exchanger 140 . The evaporated refrigerant is introduced into the suction pipe 162 of the compressor 110 through the four-way valve 160 and the accumulator 187 . At this time, the indoor air blowers 125 are operated.
[0032] FIG. 4 is a flow chart illustrating a control flow of the refrigerant charging method of the air-conditioner according to an embodiment of the present invention. With reference to FIG. 4 , first, a required for performing of a refrigerant amount determining mode to determine whether or not the refrigerant charged in the air-conditioner 100 is proper is received from a user (S 100 ). The controller (not shown) is installed in the OU, and the user requests performing of the refrigerant amount determining mode by using an input device (not shown).
[0033] Upon receiving the request for performing the refrigerant amount determining mode, the air-conditioner 100 is operated in a first operation mode (S 200 ). Here, the first operation mode is a mode in which the air-conditioner 100 is operated in a blowing mode. The air-conditioner, specifically, the IUs, is/are operated in the blowing mode to thereby wholly ventilate the indoor and outdoor spaces and accurately obtain indoor and outdoor temperature values in measuring indoor and outdoor temperatures (to be described).
[0034] When the OU and all the IUs are operated in the blowing mode, namely, in the first operation mode (S 200 ), the indoor expansion valves 131 and the outdoor expansion valves 132 are closed, so the refrigerant cannot be introduced into the IUs but the indoor air blowers 125 are operated.
[0035] After the air-conditioner 100 is operated in the blowing mode, it is determined whether or not a pre-set condition is met (S 300 ). Here, the pre-set condition refers to whether or not the operation time of the blowing mode is greater than or equal to a pre-set time. As mentioned above, in order to enhance reliability in wholly ventilating the indoor and outdoor spaces and measuring the indoor and outdoor temperatures, the operation time of the blowing mode is preferably set to be longer than the pre-set time.
[0036] After the air-conditioner 100 is operated in the blowing mode for longer than the pre-set time, indoor and outdoor temperatures are received from the indoor temperature sensors 176 and the outdoor temperature sensors 177 (S 400 ). If the indoor and outdoor temperatures are within pre-set temperature ranges, it is determined that the refrigerant amount determining mode can be started (S 500 ). If the indoor temperature is lower than a temperature at which cooling operation can be performed by using the air-conditioner 100 or if the outdoor temperature is higher than a temperature at which the air-conditioner 100 can be operated, operation itself of the air-conditioner is not possible. Thus, it is required to determine whether or not the air-conditioner 100 can be operated by comparing the indoor and the outdoor temperatures with the pre-set temperature ranges. In this case, it may be determined that the refrigerant amount determining mode can be started only when all the outdoor and indoor temperatures as received satisfy the pre-set temperature ranges. Also, it may be determined that the refrigerant amount determining mode can be started only when a portion (or a number) of outdoor and indoor temperatures, among outdoor and indoor temperatures of the places where the plurality of IUs are installed, satisfies the pre-set temperature range.
[0037] When it is determined that the refrigerant amount determining mode can be started (S 500 ), the operation mode of the air-conditioner 100 is changed to a second operation mode (S 600 ). Here, the second operation mode may refer to an all-room cooling operation mode in which the plurality of IUs are operated for a cooling operation. Alternatively, the IUs may be changed for the all-room heating operation and operated.
[0038] After the air-conditioner 100 is changed to the all-room cooling operation mode, the second operation mode, before determining whether or not the refrigerant charged in the air-conditioner 100 is proper, first operation variables of the air-conditioner 100 are detected and analyzed (S 700 ) to determine whether or not the air-conditioner 100 is in a stable state (S 800 ). In detail, when the all-room cooling operation is performed, the first operation variables are detected (S 700 ) to determine whether or not the air-conditioner 100 is in a stable state (S 800 ). The first operation variables include an all-room cooling operation time, an operation frequency of the compressor 110 , the difference between a target low pressure and a current low pressure, and the difference between a condensation temperature and the liquid pipe temperature. The stable state is determined depending on whether or not the first operation variables satisfy stabilization conditions. Namely, the all-room cooling operation time should be longer than a pre-set time, a variation value of the frequency of the compressor 110 should be smaller than a pre-set value during a pre-set time, the difference between the target low pressure and the current low pressure should be maintained below a pre-set value during a pre-set time, and the difference between the condensation temperature and the liquid pipe temperature should be larger than a pre-set value.
[0039] Here, the operation frequency of the compressor 110 is detected from information received from the frequency sensor 188 . The current low pressure is a current evaporation pressure which is detected from an average pressure detected by the indoor pressure sensors 152 . The condensation temperature is calculated as a saturation temperature corresponding to the pressure detected by the outdoor pressure sensor 153 , and the liquid pipe temperature is detected from information detected by the liquid pipe temperature sensor 174 . If the first operation variables do not satisfy the stabilization conditions during the pre-set time, whether or not the stabilization conditions are met can be detected again by setting and adjusting the number of target overheating degree of indoor units. However, in the present invention, the stabilization determining is not limited to the stabilization conditions with respect to the first operation variables, and whether or not the air-conditioner 100 is stable can be determined in consideration of various other operation variables.
[0040] When the air-conditioner 100 is determined to be stable, whether or not the amount of the refrigerant charged in the air-conditioner 100 is proper (S 900 , S 1000 ). Because the air-conditioner 100 is first stabilized and then whether or not the amount of charged refrigerant is proper is automatically performed, so the amount of the charged refrigerant can be accurately determined.
[0041] In the embodiment of the present invention, whether or not the amount of refrigerant charged in the air-conditioner 100 is determined based on the temperature of the liquid pipe 165 of the air-conditioner. In detail, with reference to FIGS. I to 3 , the liquid pipe temperature sensor 174 is installed at the liquid pipe 165 that connects the outdoor expansion valve 132 and the IUs. After the liquid pipe temperature is detected by the liquid pipe temperature sensor 174 (S 900 ), if the detected liquid pipe temperature is higher than a pre-set liquid pipe temperature, it is determined that the refrigerant charged in the air-conditioner 100 is not sufficient (S 1000 ).
[0042] When the amount of refrigerant is insufficient during the cooling operation, the supercooling degree is reduced due to the shortage of the amount of condensed refrigerant, increasing the opening degree of the supercooling expansion valve 182 . Accordingly, the amount of refrigerant introduced into the IUs is reduced, a discharge temperature of the compressor 110 is increased, and a discharge overheating degree is increased. The temperature of all the pipes between the IUs and the OU goes up due to the increase in the discharge overheating degree, and accordingly, the temperature of the liquid pipe 165 also goes up. Thus, the controller (not shown) compares the liquid pipe temperature detected by the measurement-facilitated liquid pipe temperature sensor 174 installed at the liquid pipe 165 and a pre-set liquid pipe temperature to determine whether or not the charged refrigerant is excessive or insufficient.
[0043] Meanwhile, if the liquid pipe temperature detected by the liquid pipe temperature sensor 174 is lower than or the same as the pre-set liquid pipe temperature, the controller determines that the refrigerant charged in the air-conditioner 100 is proper and terminates the refrigerant amount determining and charging process.
[0044] Here, the shortage amount of refrigerant according to the difference between the detected liquid pipe temperature and the pre-set liquid pipe temperature may be made into a table through experimentation and stored in a database (not shown). The controller (not shown) may calculate the shortage amount of refrigerant according to the difference between the liquid pipe temperature and the pre-set liquid pipe temperature detected from the table, and charge the refrigerant as much as the shortage amount in the air-conditioner 100 .
[0045] Whether or not the charged refrigerant is proper may be visually displayed (S 1100 ). The controller (not shown) may display whether or not the refrigerant has been properly charged by using the table stored in the database. By visually displaying whether or not the charged refrigerant is proper and the shortage amount of refrigerant to the user, the user can visually check the shortage amount of the charged refrigerant and manually charge the refrigerant to the air-conditioner 100 or automatically charge the shortage amount of the refrigerant based on the refrigerant charging method according to the present invention.
[0046] If the refrigerant charged in the air-conditioner 100 is insufficient, a certain amount of refrigerant is charged to the air-conditioner 100 (S 1200 ).
[0047] At this time, the certain amount of refrigerant refers to a pre-set amount of refrigerant, namely, a fixed quantity, and after the fixed quantity of refrigerant is charged, it may be determined whether or not the amount of charged refrigerant is proper. Alternatively, as stated above, the controller (not shown) may calculate the shortage amount of refrigerant according to the difference between the liquid pipe temperature detected from the table and the pre-set liquid pipe temperature and charge the refrigerant as much as the shortage amount to the air-conditioner. Whether or not the amount of charged refrigerant is proper may be determined by comparing the liquid pipe temperature detected by the liquid pipe temperature sensor 174 and the pre-set liquid pipe temperature.
[0048] If the amount of refrigerant charged in the air-conditioner 100 is determined to be proper (S 1300 ), the refrigerant introduced into the air-conditioner 100 is cut off (S 1400 ). The process of cutting off the introduction of the refrigerant will now be described in detail.
[0049] First, the four-way valve 160 is switched to cut off the introduction of the refrigerant and the operation of the compressor 110 is terminated. The four-way valve 160 is a flow path switching valve for switching (changing) cooling and heating operations. By switching the four-way valve 160 and terminating the operation of the compressor 110 , the all-room cooling operations of the IUs can be stopped. In this case, when the four-way valve 160 is switched while the refrigerant is being charged, an equilibrium pressure is temporarily formed between the pipe with the high pressure refrigerant and the pipe with the low pressure refrigerant in the air-conditioner 100 , restraining additional charging of the refrigerant. Thus, further introduction of the refrigerant can be cut off by switching the four-way valve 160 and terminating the operation of the compressor 110 .
[0050] FIG. 5 shows a configuration of the outdoor unit of the air-conditioner 100 illustrated in FIG. 1 and a refrigerant charging device. In order to cut off introduction of the refrigerant, a refrigerant charging device 300 that introduces the refrigerant into the air-conditioner 100 may be used.
[0051] With reference to FIG. 5 , in order to charge the refrigerant to the air-conditioner 100 , the refrigerant storage in a refrigerant storage unit 310 is supplied to the OU of the air-conditioner 100 by using the refrigerant charging device 300 .
[0052] The refrigerant charging device 300 according to an embodiment of the present invention includes a pipe assembly 350 . The pipe assembly 350 includes a first coupling pipe 330 , a second coupling pipe 340 , and a flow controller 351 . Here, the refrigerant charging device 300 is coupled with the air-conditioner 100 . The refrigerant charging device 300 may be fixedly coupled to be integrated with the OU of the air-conditioner 100 or detachably attached.
[0053] With reference to FIG. 1 , the first coupling pipe 330 is coupled with the suction pipe 162 of the compressor 110 among the liquid pipes connected to a refrigerant circuit of the air-conditioner 100 . The first coupling pipe 330 and the suction pipe 162 can be coupled via a first coupling hose 331 that connects one end of the first coupling pipe 330 and that of the suction pipe 162 . Here, the first coupling hose 331 may be omitted, and the suction pipe 162 and the first coupling pipe 330 may be directly coupled.
[0054] The suction pipe 162 is provided at the entrance, namely, at a suction stage, of the compressor 110 . Accordingly, the refrigerant introduced into the OU through the suction pipe 162 is introduced into the suction stage of the compressor 110 , so as to have a high temperature and high pressure. However, the present invention is not limited thereto and the suction pipe 162 may be connected with any portion of the refrigerant circuit where the refrigerant flows within the air-conditioner 100 to supply the refrigerant to the OU.
[0055] A manifold gauge 360 may be installed at the first coupling hose 331 . The manifold gauge 360 may indicate the pressure of the refrigerant, and without being limited thereto, the manifold gauge 360 may also indicate even a pressure-to-temperature of the refrigerant to indicate the temperature of the refrigerant over the pressure of the refrigerant. In charging the refrigerant, the manifold gauge 360 is connected to the air-conditioner 100 through various hoses or the like, and then, the refrigerant is charged until a certain operation pressure is reached.
[0056] In case of charging the shortage amount of refrigerant manually, the pressure is not uniformly maintained when the refrigerant is charged to the air-conditioner and the manifold gauge 360 varies slightly up and down while the air-conditioner 100 is being operated. Because accurate measurement can be performed after the refrigerant is stabilized to a degree (namely, uniform pressure), the pressure of the refrigerant is adjusted to a certain value, and then, after a certain time lapsed, the refrigerant is charged while checking the manifold gauge 360 .
[0057] A connection pipe 311 is connected with the refrigerant storage unit 310 , through which the refrigerant is introduced from the refrigerant storage unit 310 , and the second coupling pipe 340 is connected with the connection pipe 311 . The second coupling pipe 340 and the connection pipe 311 can be couple through a second coupling hose 341 that connects one end of the second coupling pipe 340 and that of the connection pipe 311 .
[0058] With reference to FIG. 5 , the flow controller 351 of the pipe assembly 350 connects the first coupling pipe 330 and the second coupling pipe 340 , and limits the flow of refrigerant introduced into the OU of the air-conditioner 100 . The flow speed of the refrigerant introduced into the air-conditioner 100 may be lowered by the flow controller 351 . As the flow speed of the refrigerant introduced into the air-conditioner 100 is gradually lowered by the flow controller 351 , the introduction of the refrigerant may be eventually cut off.
[0059] Namely, when the refrigerant by the shortage amount is supplied to the OU, the flow controller 351 prevents the refrigerant from being introduced while the shortage amount of the refrigerant is calculated at the initial stage, and if a large amount of flow of the refrigerant is introduced into the OU, there is a high possibility that the refrigerant exceeding the shortage amount is introduced into the OU, so the flow controller 351 limits the flow of the refrigerant such that the refrigerant introduced from the refrigerant storage unit 310 cannot be rapidly introduced into the OU. Thereafter, the flow of refrigerant is gradually reduced, and then, the introduction of the refrigerant is eventually cut off.
[0060] In order to limit the flow of the refrigerant introduced into the OU, the flow controller 351 may be a pipe with an inner diameter smaller than the first and second coupling pipes 330 and 340 , and particularly, it may be a capillary tube. Here, the refrigerant charging device 300 may further include a cutoff valve 370 to cut off the refrigerant introduced into the air-conditioner 100 from the refrigerant storage unit 310 .
[0061] The flow controller 351 may be a control valve for controlling the flow of the refrigerant by adjusting an opening degree. If the opening degree of the control valve is smaller than a certain level, the flow controller 351 may perform the function of a capillary tube as shown in FIG. 5 . In addition, by completely closing or opening the control valve, it can also perform the function of the cutoff valve 370 as shown in FIG. 5 .
[0062] With reference to FIG. 5 , the refrigerant charging device 300 may further include a check valve 345 installed at the first coupling pipe 330 or the second coupling pipe 340 and preventing the refrigerant from flowing back to the refrigerant storage unit 310 from the air-conditioner 100 . Namely, if the pressure of the refrigerant flowing to the OU from the refrigerant storage unit 310 is lowered, the refrigerant flowing in the pipes of the pipe assembly 350 might flow backward. Thus, in order to prevent the refrigerant from flowing backward, the check valve 340 is installed at the first coupling pipe 330 or the second coupling pipe 340 , to thereby stably charge the refrigerant.
[0063] When the shortage amount of refrigerant is charged from the refrigerant storage unit 310 to the refrigerant circuit, the OU of the air-conditioner 100 can close the cutoff valve 370 . The cutoff valve 370 may be provided at any portion of the refrigerant charging device 300 . After the sufficient amount of refrigerant is introduced for charging, the refrigerant flowing in the pipe assembly 350 may be additionally introduced into the refrigerant circuit. Thus, only the required amount of refrigerant can be charged by closing the cutoff valve 370 .
[0064] The preferred embodiments of the present invention have been described with reference to the accompanying drawings, and it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. Thus, it is intended that any future modifications of the embodiments of the present invention will come within the scope of the appended claims and their equivalents.
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A air-conditioner and the refrigerant charging method of the air-conditioner are disclosed. When a refrigerant amount determining mode is requested to be performed, whether or not the refrigerant amount in the air-conditioner is proper is automatically determined and a shortage amount of refrigerant can be charged. Thus, a user can easily check whether or not the refrigerant charged in the air-conditioner is sufficient or insufficient, and if the refrigerant is not sufficient, the user can automatically charge the refrigerant without having to entirely remove the refrigerant from the air-conditioner, thus increasing the user convenience and reducing time and costs.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing a branched aldehyde represented by the following formula (1); ##STR3## wherein Y represents an acyl group of two or more carbon atoms; and X represents an acyloxymethyl group represented by --CH 2 OY' (wherein Y' represents an acyl group of two or more carbon atoms), cyano group or an alkoxycarbonyl group. The branched aldehyde produced by the process of the present invention is useful as an intermediate for phamaceuticals and agricultural chemicals. For example, the branched aldehyde produced by the process of the present invention can be converted into an α, β-unsaturated aldehyde represented by the formula ##STR4## wherein X is the same as defined above, which unsaturated aldehyde is useful as an intermediate for vitamin As see Pure & Appl. Chem., 63, 45(1991); British Patent No. 1168639; Japanese Patent Application Publication No. Sho 60-9493, etc.! and zeatin, a plant hormone see U.S. Pat. No. 4,361,702!.
2. Related Art of the Invention
Processes for producing 1,2-diacetoxy-3-formylbutane, one of the branched aldehyde represented by the above formula (1), have been known, which comprises hydroformylation of 3,4-diacetoxy-1-butene in the presence of rhodium compounds (see U.S. Pat. No. 3,732,287 and German Patent Application Laid-open No. 2039078).
The U.S. Pat. No. 3,732,287 discloses that 1,2-diacetoxy-3-formylbutane can be produced in good yield through hydroformylation at an elevated temperature and an elevated pressure. The patent also discloses that the reaction temperature is preferably 60 to 120° C., more preferably 80 to 105° C. The patent further describes that the reaction pressure is generally 300 to 1200 atm., preferably 500 to 700 atm.
The German Patent Application Laid-open No. 2039078 discloses, in the Example 1, that 3,4-diacetoxy-1-butene was converted, by the hydroformylation at 600 atm. and 100° C. using a rhodium catalyst, to a mixture of 2000 g of 2-methyl-3,4-diacetoxybutanal (identical with 1,2-diacetoxy-3-formylbutane) and 1700 g of 4,5-diacetoxypentanal.
As described in the German Patent Application Laid-open No. 2039078, 3,4-diacetoxy-1-butene is a compound with an olefinic carbon-carbon double bond at a terminal of the molecule, so the hydroformylation of the compound generally gives a mixture of 4,5-diacetoxypentanal, a linear aldehyde, and 1,2-diacetoxy-3-formylbutane, a branched aldehyde.
The U.S. Pat. No. 3,732,287 and the German Patent Application Laid-open No. 2039078 both require to carry out the hydroformylation at least at a pressure as high as 300 atm in order to produce 1,2-diacetory-3-formylbutane in good yield. Therefore, the methods disclosed in these documents require high cost for equipment durable at such high pressure as described above in order to carry out the method in an industrial scale, and consequently, the production cost of 1,2-diacetoxy-3-formylbutane is disadvantageously high.
The present inventors have made attempts to reduce the pressure for the hydroformylation of 1,3-diacetoxy-1-butene for industrial advantages, and found that the selectivity to 1,2-diacetoxy-3-formylbutane was lowered. For example, the ratio of 1,2-diacetoxy-3-formylbutane and 4,5-diacetoxypentanal was 40/60 (former/latter) in the resulting product when the hydroformylation was carried out at 100 atm. and 80° C. using a rhodium carbonyl complex as a catalyst.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for industrially advantageously producing a branched aldehyde represented by the formula (1), including 1,2-diacetoxy-3-formylbutane, which comprises the hydroformylation of an olefinic compound including 3,4-diacetoxy-1-butene, as represented by the formula (2); ##STR5## wherein Y and X are independently the same as described above, using a rhodium compound as the catalyst, in which process the hydroformylation can be carried out at a lower pressure than that of the conventional method, without the reduction of selectivity to the branched aldehyde.
The object of the present invention can be achieved by a process described hereinbelow.
More specifically, the present invention provides a process for producing a branched aldehyde represented by the formula (1); ##STR6## wherein Y represents an acyl group of two or more carbon atoms; and X represents an acyloxymethyl group represented by --CH 2 OY' (where Y' represents an acyl group of two or more carbon atoms), cyano group or an alkoxycarbonyl group!, comprising subjecting an olefinic compound represented by the following formula (2); ##STR7## wherein Y and X are the same as described above, to the reaction with hydrogen and carbon monoxide in the presence of a rhodium compound and a tertiary organic phosphorus compound with an electronic parameter (υ-value) of 2080 to 2090 cm -1 or with a steric parameter (θ-value) of 150 to 180°.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in more detail.
The acyl group of two or more carbon atoms represented by Y and the acyl group of two or more carbon atoms represented by Y' in case that the X is an acyloxy group represented by --CH 2 Y', include, for example, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group and heptanoyl group. Among them, the acyl group of seven or less carbon atoms is preferable. These acyl groups may have a substituent such as fluorine atom, which does not inhibit the hydroformylation of the olefinic compound represented by the formula (2).
The alkoxycarbonyl group represented by X includes, for example, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, t-butoxycarbonyl group, pentoxycarbonyl group, hexyloxycarbonyl group and benzyloxycarbonyl group.
Examples of the olefinic compound represented by the formula (2) include 3,4-diacetoxy-1-butene, 3,4-dipropionyloxy-1-butene, 3,4-divaleroxy-1-butene, 3,4-diisovaleroxy-1-butene, 1-cyano-2-propenyl acetate, 1-cyano-2-propenyl propanoate, 1-cyano-2-propenyl benzoate, 1-methoxycarbonyl-2-propenyl acetate, 1-methoxycarbonyl-2-propenyl propanoate, 1-ethoxycarbonyl-2-propenyl benzoate, 1-t-butoxycarbonyl-2-propenyl acetate and 1-benzyloxycarbonyl-2-propenyl acetate. Among them, acetates such as 3,4-diacetoxy-1-butane, 1-cyano-2-propenyl acetate, 1-methoxycarbonyl-2-propenyl acetate, 1-t-butoxycarbonyl-2-propenyl acetate and 1-benzyloxycarbonyl-2-propenyl acetate are preferable in order to carry out the process of the present invention in an industrial scale.
The olefinic compound represented by the formula (2) can be produced, for example, by the following known processes;
(i) a process in which 1,3-butadrene is oxidized in the presence of a carboxylic acid (see U.S. Pat. No. 3,723,510);
(ii) a process in which acrolein is converted into the corresponding cyanohydrin and the resulting cyanohydrin is esterified with a carboxylic anhydride such as acetic anhydride, propionic anhydride and butanoic anhydride (see German Patent Application Laid-open No. 3634151); and
(iii) a process in which acrolein is converted into the corresponding cyanohydrin, the resulting cyanohydrin is solvolyzedwith analcohol such as methanol, ethanol, propanol, isopropanol and butanol, and the resulting product is esterified with a carboxylic anhydride such as acetic anhydride, propionic anhydride and butanoic anhydride (see German Patent Application Laid-open No. 3634151).
The rhodium compound used in the present invention includes a rhodium compound which has a catalytic activity for hydroformylation or which can be converted to a compound having a catalytic activity for hydroformylation under the reaction conditions. Examples of the rhodium compound include, for example, Rh 4 (CO) 12 , Rh 6 (CO) 16 , Rh(acac) (CO) 2 , rhodium oxide, rhodium chloride, rhodium acetylacetonate and rhodium acetate.
The rhodium compound is used at a concentration, in a reaction solution, of preferably 0.01 to 1 mg atom/liter, more preferably 0.01 to 0.25 mg atom/liter, on a rhodium atom basis from the viewpoint of productivity and production cost.
The tertiary organic phosphorus compound used in the present invention is required to have an electronic parameter (υ-value) of 2080 to 2090 cm -1 or a steric parameter(θ-value) of 150 to 180°.
The above two parameters are those defined according to the teachings of a literature C. A. Tolman, Chem. Rev., 177, 313(1977)!; the electronic parameter is defined as the frequency of the Al infrared absorption spectrum of the CO in an Ni(CO) 3 L (wherein "L" is a ligand containing phosphorous) measured in dichloromethane; and the steric parameter is defined as the apex angle of a cylindrical cone, centered at a position of 2.28 angstroms from the center of the phosphorus atom, which just touches the Van der Waals radii of the atoms most externally present in the groups bonded to the phosphorus atom.
The tertiary organic phosphorus compound used in the present invention can be represented by the following formula;
P(R.sup.1)(R.sup.2)(R)
wherein R 1 , R 2 and R 3 are independently an aryl group, an aryloxy group, an alkyl group, an alkoxy group, a cycloalkyl group or a cycloalkyloxy group, which may have a substituent.
The aryl group represented by R 1 , R 2 and R 3 includes, for example, tolyl group, xylyl group and t-butylphenyl group; and the aryloxy group represented by R 1 , R 2 and R 3 includes, for example, phenoxy group, o-t-butylphenoxy group and o-ethylphenoxy group. The alkyl group represented by R 1 , R 2 and R 3 includes, for example, n-butyl group and n-octyl group, and the alkoxy group represented by R 1 , R 2 and R 3 includes, for example, n-octyloxy group. In addition, the cycloalkyl group represented by R 1 , R 2 and R 3 includes, for example, cyclohexyl group; and the cycloalkyloxy group represented by R 1 , R 2 and R 3 includes, for example, cyclohexyloxy group. R 1 , R 2 and R 3 each may have a substituent which does not inhibit the hydroformylation.
Examples of the tertiary organic phosphorus compound include phosphites such as triphenyl phosphite, tris(2-methylphenyl) phosphite, tris(2-ethylphenyl) phosphite, tris(2-isopropylphenyl) phosphite, tris(2-phenylphenyl) phosphite, tris(2,6-dimethylphenyl) phosphite, tris(2-t-butylphenyl) phosphite, tris(2-t-butyl-5-methylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, di(2-methylphenyl)(2-t-butylphenyl) phosphite and di(2-t-butylphenyl)(2-methylphenyl) phosphite; and phosphines such as tricyclohexylphosphine.
If a tertiary organic phosphorus compound with both the electronic parameter and steric parameter outside the range described above, such as triphenylphosphine (υ: 2068.9 cm -1 , θ: 145°), tri-o-tolylphosphine (υ: 2066.6 cm -1 , θ: 194°) and tri-n-butyl phosphite (υ: 2076 cm -1 , θ: 109°), is used, a linear aldehyde, a by-product, represented by the formula (3); ##STR8## wherein X and Y are the same as described above, is formed in a considerable amount, so that the selectivity to the branched aldehyde represented by the formula (1) is reduced.
In the present invention, the tertiary organic phosphorus compound with an electronic parameter of 2050 to 2090 cm -1 and a steric parameter of 150 to 180°, such as tris(2-phenylphenyl) phosphite (υ: 2085.0 cm -1 , θ: 152°), tris(2-t-butylphenyl) phosphite (υ: 2086.1 cm -1 , θ: 175°), tris(2-t-butyl-5-methylphenyl) phosphite (2085.6 cm -1 , θ: 175°), tris(2,4-di-t-butylphenyl) phosphite (υ: 2085.6 cm -1 , θ: 175°) and tricyclohexylphosphine (υ:2056.4 cm -1 , θ: 170°), is preferable, because a higher reaction rate and selectivity to the branched aldehyde represented by the formula (1) can be attained.
The tertiary organic phosphorus compound is generally used at a concentration of 1 to 20 millimoles/liter in a reaction solution. The tertially organic phosphorous compound is preferably used at a concentration of 2 to 10 millimoles/liter in a reaction solution, because the higher reaction rate and selectivity to the branched aldehyde represented by the formula (1) can be attained.
The tertiary organic phosphorus compound may be used singly or in combination.
In the hydroformylation according to the present invention, tertiary amines such as triethylamine and triethanolamine; and basic substances including carbonates or hydrogencarbonates such as sodium hydrogencarbonate, sodium carbonate and potassium carbonate can be used.
The hydroformylation according to the present invention is carried out generally at a temperature within a range of 20 to 150° C., preferably at a temperature within a range of 40 to 120° C. When the reaction temperature is less than 20° C., the reaction rate is reduced. On the other hand, when the reaction temperature is higher than 150° C., the selectivity to the branched aldehyde represented by the formula (1) tends to be reduced.
The molar ratio of hydrogen and carbon monoxide in a gaseous mixture of hydrogen and carbon monoxide used for the hydroformylation is generally within a range of 1/5 to 5/1 as an inlet gaseous ratio. In addition, a small amount of gases inactive to the hydroformylation, for example, nitrogen and argon, may be present in the reaction atmosphere.
The reaction pressure is generally within a range of 30 to 250 atmospheric pressure. The reaction pressure is preferably within a range of 30 to 200 atmospheric pressure, more preferably within a range of 30 to 150 atmospheric pressure, in order to attain higher reaction rate and selectivity to the branched aldehyde represented by the formula (1) and to carry out the reaction industrially advantageously from the viewpoint of equipment and easy operation.
The hydroformylation according to the present invention can be carried out in a known reaction apparatus such as stirring-type reaction vessel or bubble-column type reaction vessel. The hydroformylation can be carried out in a batch-wise manner or in a continuous manner.
The hydroformylation can be carried out either in the absence of a solvent or in the presence of an appropriate solvent. Such solvent includes, for example, saturated aliphatic hydrocarbons such as hexane, heptane and octane; aromatic hydrocarbons such as benzene, toluene and xylene; ethers such as diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran and dioxane; and halogenated hydrocarbons such as dichloromethane. The solvent may be used singly or in combination. The solvent is preferably used in an amount that does not suppress the volumeric efficiency of the hydroformylation.
According to the hydroformylation of the present invention, the linear aldehyde represented by the formula (3) is produced, other than the objective branched aldehyde represented by the formula (1). The ratio of the two, namely the ratio of the branched aldehyde represented by the formula (1) to the linear aldehyde represented by the formula (3) (abbreviated as "ratio i/n" hereinafter), is generally 1.5 or more under the reaction pressure of 200 atm, which is lower than that of the conventional method. Thus, a product containing a higher content of the branched aldehyde represented by the formula (1) can be obtained. If necessary, the branched aldehyde represented by the formula (1) can be separated from the linear aldehyde represented by the formula (3), by known means such as distillation.
The branched aldehyde represented by the formula (1) wherein X is cyano group or an alkoxycarbonyl group is a novel compound. Examples of such novel compound include 1-cyano-2-formylpropyl acetate, 1-cyano-2-formylpropyl propionate, 1-cyano-2-formylpropyl butyrate, 1-cyano-2-formylpropyl isobutyrate, l-cyano-2-formylpropyl valerate, 1-cyano-2-formylpropyl hexanoate, 1-cyano-2-formylpropyl heptanoate, 1-methoxycarbonyl-2-formylpropyl acetate, 1-methoxycarbonyl-2-formylpropyl propionate, 1-methoxycarbonyl-2-formylpropyl butyrate, 1-methoxycarbonyl-2-formylpropyl isobutyrate, 1-methoxycarbonyl-2-formylpropyl valerate, 1-methoxycarbonyl-2-formylpropyl hexanoate, 1-methoxycarbonyl-2-formylpropyl heptanoate, 1-ethoxycarbonyl-2-formylpropyl acetate, 1-ethoxycarbonyl-2-formylpropyl propionate, 1-propoxycarbonyl-2-formylpropyl acetate, 1-propoxycarbonyl-2-formylpropyl propionate, 1-butoxycarbonyl-2-formylpropyl acetate, 1-butoxycarbonyl-2-formylpropyl propionate, 1-t-butoxycarbonyl-2-formylpropyl acetate, 1-t-butoxycarbonyl-2-formylpropyl propionate, 1-benzyloxycarbonyl-2-formylpropyl acetate and 1-benzyloxycarbonyl-2-formylpropyl propionate.
The reaction solution obtained by the hydroformylation according to the present invention can be used, as it is, for the starting meterials of the next reaction. Or, if desired, a fraction containing the branched aldehyde represented by the formula (1) obtained by vaporization of the reaction solution under reduced pressure, can be used for the next reaction.
The whole or a part of the rhodium compound in the residuals after the vaporization of the reaction solution can be recycled for the hydroformylation.
Furthermore, the branched aldehyde represented by the formula (1) can be isolated from the fraction containing the same through purification by known means such as distillation.
The branched aldehyde represented by the formula (1) can be converted, by the elimination of a carboxylic acid (YOH; wherein Y is the same as defined above), into an α, β-unsaturated aldehyde represented by the formula (4); ##STR9## wherein X is the same as defined above. The elimination of a carboxylic acid from the branched aldehyde represented by the formula (1) is generally carried out by heating the branched aldehyde in the presence or absence of a catalyst. From the viewpoint of reaction rate, the elimination is preferably carried out in the presence of a catalyst. Examples of the catalyst include acidic catalyst such as sulfuric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, alumina, silica alumina, activated clay and ion-exchange resin; and basic catalyst such as sodium hydroxide, potassium hydroxide, triethylamine and triethanolamine. The catalyst is used generally at an amount of 0.01% by weight or more, preferably at an amount of 0.05 to 5% by weight, based on the reaction solution for the elimination.
The elimination of a carboxylic acid from the branched aldehyde represented by the formula (1) is carried out preferably at a temperature of 30° C. or more, more preferably at a temperature within a range of 60 to 120° C.
The elimination is generally carried out at a pressure within a range of 0.001 to 10 atmospheric pressure (absolute pressure). If desired, the elimination is carried out under reduced pressure to remove the formed carboxylic acid from the reaction solution.
The elimination can be carried out either in the absence of a solvent or in the presence of an appropriate solvent. Examples of such solvent include, for example, aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane and heptane; ethers such as diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran and dioxane; and halogenated hydrocarbons such as dichloromethane. These solvents may be used singly or in combination. The solvent is preferably used in an amount that does not suppress the volumeric efficiency of the elimination.
The elimination can be carried out in a stirring-type reaction vessel with the catalyst dissolved or suspended in the reaction solution, or in a fixed-bed type reaction vessel charged with a carried-type catalyst. Also, the elimination can be carried out in a batch-wise manner or in a continuous manner.
After the reaction is completed, the resulting α, β-unsaturated aldehyde represented by the formula (4) can be isolated by a known process, for example, comprising neutralizing the formed carboxylic acid, if necessary, and distilling the reaction mixture.
The thus obtained, β-unsaturated aldehyde represented by the formula (4) can be purified by known method such as distillation under reduced pressure and column chromatography.
Other features of the present invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration of the present invention and are not intended to be limiting thereof.
EXAMPLES
Example 1
An autoclave equipped with a gas inlet, a sampling port and an electromagnetic stirrer and having an internal volume of 300 ml, was charged with 90 ml (194.8 g, 0.55 mol) of 3,4-diacetoxy-1-butene and a solution of 2.58 mg (0.01 mmol) of rhodium dicarbonyl acetylacetonate and 323 mg (0.5 mmol) of tris(2,4-di-t-butylphenyl) phosphite in 10 ml of toluene under nitrogen while avoiding their contact with air. Then the atmosphere inside the autoclave was replaced with a gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. The pressure inside the autoclave was adjusted to 100 atmospheric pressure (gauze pressure) with the same gaseous mixture and the temperature inside the autoclave was raised to 60° C. The hydroformylation was effected for 8 hours at 60° C. while maintaining the pressure inside the autoclave at 100 atmospheric pressure (gauze pressure) with the gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1.
Analysis of the reaction solution with gas chromatography column: G-300, 1.2 mm Φ×20 m, manufactured by Chemicals Inspection and Testing Institute, Japan; column temperature: raised to 200° C. from 70° C. (rate of temperature rise: 10° C./min)! showed that the conversion of the 3,4-diacetoxy-1-butene was 89% and the selectivity the hydroformylated product was 99%. The analysis also showed that the reaction solution contained 72.5 g (0.36 mol) of 1,2-diacetoxy-3-formylbutane and 25.4 g (0.13 mol) of 4,5-diacetoxypentanal at the ratio i/n of 2.8 (=74/26).
Example 2
The general procedures of Example 1 were repeated except that the amount of tris(2,4-di-t-butylphenyl) phosphite, the reaction temperature and the reaction time were changed to 129 mg (0.5 mmol), 80° C. and 2 hours, respectively. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 92%, the selectivity to the hydroformylated product was 99% and the ratio i/n was of 2.0 (=67/33).
Example 3
The general procedures of Example 1 were repeated except that the reaction pressure, the reaction temperature and the reaction time were changed to 90 atmospheric pressure, 80° C. and 2 hours, respectively. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 99%, the selectivity to the hydroformylated product was 98% and the ratio i/n was 2.2 (=69/31).
Example 4
The general procedures of Example 1 were repeated except that 155 mg (0. 5 mmol) of triphenyl phosphite was used instead of 323 mg of tris (2,4-di-t-butylphenyl) phosphite and that the reaction pressure, the reaction temperaure and the reaction time were changed to 90 atmospheric pressure, 80° C. and 4 hours, respectively. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 71%, the selectivity to the hydroformylated product was 98% and the ratio i/n was 2.2 (=69/31).
Comparative Example 1
The general procedures of Example 4 were repeated except that 131 mg (0.5 mmol) of triphenylphosphine was used instead of 155 mg of triphenyl phosphite. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 11%, the selectivity to the hydroformylated product was 98% and the ratio i/n was 1.1 (=53/47).
Comparative Example 2
The general procedures of Example 4 were repeated except that 125 mg (0.5 mmol) of tri-n-butyl phosphite was used instead of 155 mg of triphenyl phosphite. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 19%, the selectivity to the hydroformylated product was 98% and the ratio i/n was 1.2 (=54/46).
Example 5
An autoclave equipped with a gas inlet, a sampling port and an electromagnetic stirrer and having an internal volume of 300 ml, was charged with 50 ml (52.7 g, 0.306 mol) of 3,4-diacetoxy-1-butene and a solution of 2.58 mg of rhodium dicarbonyl acetylacetonate and 140 mg (0.5 mmol) of tricyclohexylphosphine in 50 ml of toluene under nitrogen while avoiding their contact with air. Then, the atmosphere inside the autoclave was replaced with a gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. The pressure inside the autoclave was adjusted to 90 atmospheric pressure (gauze pressure) with the same gaseous mixture and the temperature inside the autoclave was raised to 80° C. The hydroformylation was effected for 2 hours at 80° C. while maintaining the pressure inside the autoclave at 90 atmospheric pressure (gauze pressure) with the gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 44% and the selectivity to the hydroformylated product was 99%. The anaysis also showed that the reaction solution contained 13.55 g (67 mmol) of 1,2-diacetoxy-3-formylbutane and 8.29 g (41 mmol) of 4,5-diacetoxypentanal and 3.55 g (25 mmol) of 3-methyl-4-oxo-2-butenyl acetate which was formed by the elimination of acetic acid from 1,2-diacetoxy-3-formylbutane. The ratio i/n was 2.2 (=69/31), wherein 3-methyl-oxo-2-butenyl acetate was calculated as 1,2-diacetoxy-3-formylbutane.
Comparative Example 3
The general procedures of Example 5 were repeated except that tricyclohexylphosphine was not used. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that the conversion of the 3,4-diacetoxy-1-butene was 41%, the selectivity to the hydroformylated product was 95% and the ratio i/n was 0.67 (=40/60).
Example 6
An autoclave equipped with a gas inlet, a sampling port and an electromagnetic stirrer and having an internal volume of 300 ml, was charged with 30 ml (30.8 g, 0.246 mol) of 1-cyano-2-propenyl acetate and a solution of 3.9 mg (0.015 mmol) of rhodium dicarbonyl acetylacetonate and 485 mg (0.75 mmol) of tris(2,4-di-t-butylphenyl) phosphite in 120 ml of toluene under nitrogen while avoiding their contact with air. Then, the atmosphere inside the autoclave was replaced with a gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. The pressure inside the autoclave was adjusted to 90 atmospheric pressure with the same gaseous mixture and the temperature inside the autoclave was raised to 80° C. The hydroformylation was effected for 2 hours at 80° C. while maintaining the pressure inside the autoclave at 90 atmospheric pressure (gauze pressure) with a gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. Analysis of the reaction solution with gas chromatography column: G-300, 1.2 mmΦ×20 m; column temperature: raised to 200° C. from 100 ° C. (rate of temperature rise: 10° C./min)! showed that the conversion of the 1-cyano-2-propenyl acetate was 99% and the selectivity to the hydroformylated product was 98%. The analysis also showed that the reaction solution contained 31.1 g (201 mmol) of 1-cyano-2-formylpropyl acetate and 5.9 g (38 mmol) of 1-cyano-4-oxobutyl acetate, a linear aldehyde. The ratio i/n was 5.3.
Distillation of the reaction solution under reduced pressure gave 30.7 g of 1-cyano-2-formylpropyl aceate as a fraction with a boiling point of 75° C. to 81° C./1 mmHg (purity: 91%). The obtained 1-cyano-2-formylpropyl acetate was a mixture of two diastereomers (threo isomer and erythro isomer). Properties of the product are shown below.
Diastereomer (1)
1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 1.39(d, 3H, J=6.8 Hz), 2.14(s, 3H), 3.03(dq, 1H, J =6.0 Hz, 6.8 Hz), 5.66(d, 1H, J=6.0 Hz), 9.67(s, 1H)
Diastereomer (2)
1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 1.43(d, 3H, J=6.7 Hz), 2.14(s, 3H), 2.95(dq, 1H, J=3.8 Hz, 6.7 Hz), 5.70(d, 1H, J=3.8 Hz), 9.67(s, 1H)
The ratio of diastereomers, diastereomer (1)/diastereomer (2), was about 50/50, as calculated on the basis of 1 H-NMR spectrum.
In addition, 6.4 g of 1-cyano-4-oxobutyl acetate was obtained as a fraction with a boiling point of 98° C. to 102° C./1 mmHg (purity: 81%) by the above distillation. Propeties of the compound are shown below. 1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 2.15(s, 3H), 2.22-2.30(m, 2H), 2.73-2.78(m, 2H), 5.41(t, 1H, J=5.8 Hz), 9.81(s, 1H)
Example 7
An autoclave equipped with a gas inlet, a sampling port and an electromagnetic stirrer and having an internal volume of 300 ml, was charged with 30 ml (31.8 g, 0.201 mol) of 1-methoxycarbonyl-2-propenyl acetate and a solution of 3.9 mg of rhodium dicarbonylacetylacetonate and 485 mg of tris(2,4-di-t-butylphenyl) phosphite in 120 ml of toluene under nitrogen while avoiding their contact with air. Then, the atmosphere inside the autoclave was replaced with a gaseous mixture of hydrogen and carbon monoxide at a molar ratio of 1/1. The pressure inside the autoclave was adjusted to 90 atmospheric pressure with the same gaseous mixture and the temperature inside the autoclave was raised to 80° C. The hydroformylation was effected for 2 hours at 80° C. while maintaining the pressure inside the autoclave at 90 atmospheric pressure (gauze pressure) with a gaseous mixture of hydrogen and carbon monoxide ata molar ratio of 1/1. Analysis of the reaction solution with gas chromatography under the same conditions of Example 6 showed that the conversion of the 1-methoxycarbonyl-2-propenyl acetate was 99% and the selectivity to the hydroformylated product was 98%. The analysis also showed that the reaction solution contained 28.2 g (150 mmol) of 1-methoxycarbonyl-2-formylpropyl acetate and 8.4 g (44 mmol) of 1-methoxycarbonyl-4-oxobutyl acetate, a linear aldeyde. The ratio i/n was 3.4.
Distillation of the reaction solution under reduced pressure gave 28.5 g of 1-methoxycarbonyl-2-formylpropyl aceate as a fraction with a boiling point of 87° C. to 89° C./1 mmHg (purity: 89%). The obtained 1-methoxycarbonyl-2-formylpropyl acetate was a mixture of two diastereomers (threo isomer and erythro isomer). Properties of the product are shown below.
Diastereomer (1)
1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 1.21(d, 3H, J=6.5 Hz), 2.16(s, 3H), 2.96-2.99(m, 1H), 3.78(s, 3H), 5.38(d, 1H, J=4.2 Hz), 9.69(s, 1H)
Diastereomer (2)
1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 1.22(d, 3H, J=6.5 Hz), 2.13(s, 3H), 2.96-2.99(m, 1H), 3.79(s, 3H), 5.59(d, 1H, J=3.0 Hz), 9.67(s, 1H)
The ratio of diastereomers, diastereomer (1)/diastereomer (2), was about 59/41, as calculated on the basis of 1 H-NMR spectrum.
In addition, 8.4 g of 1-methoxycarbonyl-4-oxobutyl acetate was obtained as a fraction with a boiling point of 107° C. to 108° C./1 mmHg (purity: 90%) by the above distillation. Properties of the compound are shown below.
1 H-NMR(270 MHz, CDCl 3 , TMS) δ(ppm): 2.13(s, 3H), 2.16-2.27(m, 2H), 2.58-2.65(m, 2H), 3.75(s, 3H), 5.04(dd, 1H, J=4.5 Hz, 6.7 Hz), 9.78(s, 1H)
Example 8
The general procedures of Example 7 were repeated except that the amount of rhodium dicarbonyl acetylacetonate and the reaction temperature were changed to 7.8 mg and 60° C., respectively. Analysis of the reaction solution with gas chromatography under the same conditions of Example 6 showed that the conversion of the 1-methoxycarbonyl-2-formylpropyl acetate was 99% and the selectivity to the hydroformylated product was 98%. The analysis also showed that the reaction solution contained 31.1 g (165 mmol) of 1-methoxycarbonyl-2-formylpropyl acetate and 5.5 g (29 mmol) of 1-methoxycarbonyl-4-oxobutyl acetate. The ratio i/n was 5.7.
Reference Example 1
A three-necked flask of an internal volume of 200 ml was charged with 100 g of the reaction solution obtained in the Example 1 containing 62 g (0.31 mol) of 1,2-diacetoxy-3-formylbutane! and 0.5 g of p-toluenesulfonic acid monohydrate under nitrogen. Then the resulting mixture was heated to 80° C. and stirred for 5 hours under atmospheric pressure. The resulting reaction mixture was cooled to room temperature and neutralized with 0.8 g of triethanolamine. Analysis of the reaction solution with gas chromatography under the same conditions of Example 1 showed that 41 g (0.29 mol) of 3-methyl-4-oxo-2-butenyl acetate was formed. Distillation of the reaction solution under reduced pressure gave 35 g of 3-methyl-4-oxo-2-butenyl acetate (boiling point: 121° C./30 Torr).
Reference Example 2
A three-necked flask of an internal volume of 50 ml was charged with 15 g of the reaction solution obtained in the Example 6 containing 13.6 g (87.7 mmol) of 1-cyano-2-formylpropyl acetate! and 0.15 g of p-toluenesulfonic acid monohydrate under nitrogen. Then the-resulting mixture was heated to 100° C. and stirred for 3 hours under atmospheric pressure. The reaction mixture was cooled to room temperature and neutralized with 0.2 g of triethanolamine. Analysis of the resulting reaction mixture with gas chromatography under the same conditions of Example 6 showed that 7.7 g (81 mmol) of 3-methyl-4-oxo-2-butenenitrile was formed. The conversion of the 1-cyano-2-formylpropyl aceate was 100% and the selectivity to the 3-methyl-4-oxo-2-butenenitrile was 92%.
Distillation of the reaction mixture under reduced pressure gave 7.3 g of 3-methyl-4-oxo-2-butenenitrile (boiling point: 75° C. to 81° C./1 mmHg, purity: 95%).
Reference Example 3
A three-necked flask of an internal volume of 50 ml was charged with 20 g of the reaction solution obtained in Example 7 containing 18.0 g (95.7 mmol) of 1-methoxycarbonyl-2-formypropyl acetate! and 0.5 g of triethanolamine under nitrogen. Then the resulting mixture was heated to 100° C. and stirred for 3 hours under atmospheric pressure. The reaction mixture was cooled to room temperature. Analysis of the reaction mixture with gas chromatography under the same conditions of Example 6 showed that 10.9 g (85.2 mmol) of methyl 3-methyl-4-oxo-2-butenoate was formed. The conversion of the 1-methoxycarbonyl-2-formylpropyl aceate was 100% and the selectivity to the methyl 3-methyl-4-oxo-2-butenoate was 90%.
Distillation of the reaction mixture under reduced pressure gave 8.9 g of methyl 3-methyl-4-oxo-2-butenoate (boiling point: 45° C. to 46° C./3 mmHg, purity: 99%)
Reference Example 4
The general procedures of the Reference Example 3 were repeated except that 50 g of the reaction solution obtained in Example 8 containing 11.1 g of 1-methoxycarbonyl-2-formylpropyl acetate! was used instead of 20 g of the reaction solution obtained in Example 7. Analysis of the reaction mixture with gas chromatography under the same conditions of Example 6 showed that 7.0 g of methyl 3-methyl-4-oxo-2-butenoate was formed. The conversion of the 3-methoxycarbonyl-2-formylpropyl acetate was 100% and the selectivity to the methyl 3-methyl-4-oxo-2-butenoate was 93%.
Obviously, numerous modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.
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It is provided a process for industrially advantageously producing a branched aldehyde represented by the formula; ##STR1## wherein Y represents an acyl group of two or more carbon atoms; and X represents an acyloxymethyl group represented by --CH 2 OY' (where Y' represents an acyl group of two or more carbon atoms), cyano group or an alkoxycarbonyl group! which is useful as an intermediate for pharmaceuticals and agricultural chemicals, comprising subjecting an olefinic compound represented by the following formula; ##STR2## (wherein Y and X are the same as defined above), to the reaction with hydrogen and carbon monoxide in the presence of a rhodium compound and a tertiary organic phosphorus compound with an electronic parameter (υ-value) of 2080 to 2090 cm -1 or with a steric parameter (θ-value) of 150 to 180°.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a light, or laser, printer in which a photosensitive or photoconductive media is moved in a first direction relative to a light, or laser, beam which is scanned in a second direction, perpendicular to the first direction, in order to selectively expose, or print, regions of the media. The present invention particularly relates to compensating for variations in the velocity of the first direction movement of the media, which velocity variations cause undesirable variations in the image produced, or printed.
2. Description of the Prior Art
In a light, or laser, printer of either the scanning head or linearly-arrayed Light Emitting Diode (LED) type, an electrically charged, photosensitive (normally a photoconductive) media is moved in front of the light source. The photosensitive media may be, for example, either a photoconductive drum or belt. This photoconductive media is selectively discharged (exposed) in certain areas by the laser beam in order to form an image. In some laser printers the toner is maintained charged at the general electrical potential of the photoconductive media, making that there is initially no attraction nor any pickup of the charged toner by the charged media. Then the photoconductive media is selectively discharged by the laser beam. Toner is thereby attracted and held only to the area of the media that is exposed to the laser beam during an electrostatic printing process, causing the printing of black (or color) in this area.
In other laser printers, the photoconductive meda and the toner are oppositely charged. An area of the media is then selectively discharged (exposed) by the laser beam during the electrostatic printing process, discharging this area to the general electrical potential of the toner. The toner is not attracted to this area of the media, thereby printing black (or color) in all other areas of the media that were not discharged (exposed) by the laser beam. The principles of the present invention are applicable to either type of laser printer. The image that is generated on the photoconductive media is transferred to a final media which may be, for example, either paper or plastic film. Alternatively, the photoconductive media may itself be a final media, such as a specially coated photoconductive paper.
In either the case of directly- or of indirectly-exposed photoconductive media, and for either the case of printing black or printing white from the laser-exposed regions, it is extremely difficult to precisely control the instantaneous velocity of the media, which is slow moving in relation to the high speeds at which it is exposed with a light beam. It is desired that this velocity should be absolutely uniform and invariant in order that the image selectively exposed on the photosensitive and photoconductive media should be correspondingly uniform and invariant. Small instantaneous velocity changes will, however, be irreducibly present in the movement of the media.
These instantaneous variations in the velocity of the moving photosensitive media have many causes. These causes are inherent in the mechanical system causing movement of the media. This mechanical system incorporates bearings, gear teeth, belts and other mechanical elements which may be subject to variation in shape, fit, finish, friction, elasticity, slip, concentricity, alignment, and other factors affecting the precision and uniformity of the mechanical drive. If an electric motor is involved then the poles of such a motor may be non-uniform. There is friction within the mechanical system between the moving and non-moving parts. The media itself may provide an irregular load on the mechanical drive system. The drive system may be subject to slip between its parts, and may be affected by shock or vibration. Finally, the entire mechanical drive system may be subject to effects of wear.
Many of the mechanical causes of slight velocity variations in the movement of the photosensitive, and photoconductive, media may be minimized by the use of precision mechanical components. However, these components (such as anti-backlash gears) significantly raise the cost of the mechanical drive system while not entirely eliminating variations in the velocity of the movement of the media.
The irreducible and inescapable velocity variations occurring in the movement of the photosensitive, and photoconductive, media within a laser printer are adverse to the quality of the printed image. These adverse effects are particularly noticeable when printing very narrow and very closely spaced parallel lines which are perpendicular to the direction in which the media is moving. Lines will appear to vary in thickness and in line-to-line spacing. They will not have the desired appearance of a finely ruled reticular grid. Additionally, the velocity variations will cause visually perceptible imperfections when a laser printer is used to print a grey scale consisting of very small black dots or squares alternating with unprinted dot or square areas. Velocity variations in the movement of the photosensitive media will appear to cause striations, or gradient variations in density, across the workpiece. These striations are formed in the direction perpendicular to the direction of media movement. Both the variations in the printing of the lines and of the grey scale may be quite small. However, the human eye is very sensitive to small changes in this type of pattern.
The visually perceptible changes in the parallel line, or grey scale, patterns primarily arise from three factors. First, there is a change in the absolute height of features being exposed and printed. This change in absolute height of the features is due to the change in velocity of the photosensitive media, and is directly proportional to such change. This change is the most tolerable to the human eye. If it were the only change occurring than both parallel black printed lines and the intervening white, or unprinted, lines would both be equally thicker or thinner with a respective slowing or speeding of the media velocity. Likewise, in a grey scale the typically square areas of black and white would each vary as respective identical black and white rectangles of heights that were either taller or shorter as the media velocity decreased or increased.
If the media velocity were to vary rapidly during the period of scanning just a few lines, or during the scanning of a single line, with the laser beam then these absolute height variations might be visually perceived as imperfections. Similarly, if the variations were to be significantly larger, then they may again be perceived as imperfections. But neither extremely rapid nor extremely large variations are normally the case. Furthermore, the human eye is typically sensitive only to the ratio between white and black areas for uniform fine patterns, and is not offended if horizontal lines, and grey-scale squares, are in some places a little "fatter" and in other places a little "thinner" so long as the ratio of black to white in these areas is constant throughout a large region, and preferably over the entire printed page. This means that a single page having thicker and thinner black horizontal lines will appear visually satisfactory (if the variation in media velocity and resultant feature height is neither too great nor too fast) so long as everywhere where the black lines are thick the intervening white lines are also thick, and everywhere the black lines are thin the white lines are also thin.
When an equal ratio of white to black is preserved everywhere in the image then the image will be perceived to be differentiated, but will also be perceived to be esthetically satisfactory. Unfortunately, the remaining two sources of visually perceptible changes in printed parallel lines, or grey scale, cause localized variations in the black to white ratio, and produce effects in the printed image, that are both readily perceived by the eye and appear as an esthetically undesirable variation in image uniformity.
The second source of visually perceptible change, and most important source of that visually perceptible change that is undesirable, in a printed image due to instantaneous velocity variations in the photoconductive media is resultant from the laser discharge (exposure) of the photoconductive media. The light intensity, and light energy, of the laser beam is essentially in a Gaussian distribution spatially around the spot where the laser light beam is focused. Meanwhile, the charged photoconductive media requires a certain amount of light energy for a certain time in order to discharge any point upon the photoconductive media to the state wherein it will print an opposite color to that which the color that a fully charged photoconductive media will print. In this selective discharge of a photoconductive media by a laser light beam there will be a threshold boundary region (relative to the focus point of the laser beam) that is dependent upon both the duration of exposure and upon the intensity level of the exposing light. This threshold boundary region discriminates between areas wherein the media has received insufficient light energy so as to remain charged, versus those areas wherein the media has received sufficient light energy during exposure to the laser beam so as to become discharged.
If the media slows down then the same amount of laser light will discharge more media area because the beam will dwell longer at each location on the media, and will expose a wider swath. In other words, if the laser beam intensity remains constant, then the effective spot size of the exposed area will increase for a slow media and will decrease for a fast media. This variation in the spot size is in both the horizontal and vertical directions. This causes a corresponding variation in the vertical size of printed features such as small horizontal lines and rectangles, and in the horizontal size of printed feature such as small verticle lines and rectangles. The precise appearance as to whether the features assume a localized appearance which is darker or lighter with diminished or increased media velocity is, of course, a function of whether the laser-exposed regions of the photoconductive media are printing white or black. However, the underlying nature of the change is the same in all instances, uniformly producing an undesirable variation in image uniformity.
A third source of visually perceptible, and undesirable, changes in a printed image due to variations in the instantaneous velocity of the photoconductive media is due to the exposure of images as a combination of scan lines. There is a lack of direct proportionality between the exposed image areas and the velocity of the photoconductive media because the exposed areas of the image are generally built up from a plurality of overlapping scan lines wherein the scanned laser beam was turned on. Since some of the change in velocity of the media results in a change in the percentage amount of overlap between successive scan lines--which overlap is not visible in the final image--then the change in the absolute height of the exposed image areas is not directly proportional to the change in media velocity. When the media is moving underneath the light, or laser, with a relatively faster speed then the exposed areas of the printed image will be of larger absolute heights, but these heights will actually be of a reduced ratio relative to those heights of the unexposed image areas, which heights are also increased. When the media is moving at a relatively slower speed then the exposed areas will be of smaller absolute heights, but these heights will actually be of an increased ratio relative to those heights of the unexposed image areas, which heights are also decreased.
An explanation of this third cause by which variations in the media velocity effect the ratio of the heights of exposed to unexposed image areas, and the equivalent ratio of the relative eights of white and black areas, is as follows. The monochrome image is created by the exposing laser beam. This laser beam so exposing a one color of the image is overlapped in its exposure of a one scan line to its exposure of the next scan line. Just one color, black or white, of the monochrome image is created by the exposing laser beam. Let this color be specified, by example and in way of illustration, to be white.
Normally an image, for example a horizontal white print line alternating with a horizontal black print line, is created by turning on the scanning laser beam for a certain number of scan lines and then, successively, leaving the scanning laser beam turned off for a certain number of scan lines. For equal width print lines, these certain numbers of scan lines upon which the laser beam is turned on and turned off are not identical. This is because there is overlap of one laser scan line to the next in the direction along the scan lines and perpendicular to the media movement. Because of this overlap a last scan line at which a laser is turned on within any white area (the white print line) will cause the white exposure of some of that height which is traced by the next scan line during which the laser is not turned on. Similarly, the last scan line at which the laser remains off at any black area (the black print line) will be partially exposed white by the next successive scan line when the laser beam is turned on.
This is simply an operation, by example, wherein white overwrites black. When successive scans of a scanning laser beam overlap, as is the actual case, then this overwrite operation immediately requires that fewer scan lines should be successively exposed, or written white, than will be next following scan lines left unexposed, or "written" black, in order to obtain equal height white and black print lines.
Moreover, this overwrite and overlap has a pronounced effect when the media varies in velocity. When the media slows then the overlap between scan lines is greater, reducing the height of the white exposed area. Also, and more importantly in visual effect, the white scan lines will overlap to a greater extent adjacent "black" scan lines, much reducing the ratio of black to white (as well as diminishing the absolute height of both features). It is this media-velocity-dependent alteration in the ratio of the heights between exposed white and black image areas which is especially detectable by, and disconcerting to, the human eye.
Drawings figures which aid in the visualization of the fairly complex second and third causes of nonuniformity in the printed image occurring with variations in the velocity of the photoconductive media will be discussed in conjunction with the description of the preferred embodiment of the present invention within this specification. For now, it is sufficient to understand that it is the maintenance of invariance in the ratio of exposed to unexposed, white to black, regions in the presence of media velocity variations that is dealt with by the present invention. If, for example, the ratio is 50%, meaning that half of the area is being printed with lines or grey scale dots or like images, then the present invention will act to preserve this 50% ratio even in the event of velocity variations in the photoconductive media. These velocity variations as would normally lead, by action of the second and third causes, to a nonuniformity in the ratio of the black and white areas within the exposed image.
After the three causes of variation in both the absolute, and the relative, heights of exposed, and printed, features dependent upon velocity of the media come to be understood, it might naturally seem (without much study or thought) that preferred solution in accordance with the present invention that will be taught within this specification is a sole, natural or only solution--especially since it works so well. This is not the case, and the solution in accordance with the present invention is actually quite exceptional in consideration of what the prior art might possibly suggest for the solution or amelioration of the image nonuniformity problem--should this problem even be recognized.
In the first place, it is not directly apparent from the prior art what could be done about this problem. Remember, the printed image nonuniformity problem particularly manifests itself as changes the ratio of dark-to-light areas in a grey scale, and as irregular heights and density of spaced parallel horizontal lines. The photoconductive media which is subject to undesirable exposure variations may be either a photoconductive drum, a photoconductive belt, or the like. These media may transfer the image to a final media such as paper or plastic film, or the final media itself may be photoconductive, such as a specially coated paper. Regardless of the processing transpiring after exposure, variations in the heights of features exposed which variations are due to instantaneous velocity variations in the photoconductive media necessarily result in undesirable, visually perceptible, variations in the printed image. Therefore, although not directly taught in the prior art, it might be reasonably hypothesized that something has got to be done to effect the areas that are exposed.
It might be firstly hypothesized that printed image variations should be attempted to be dealt with by an improved mechanical positional control of the photoconductive medium, possibly by use of an electromechanical feedback control loop. This is not the method adapted by the present invention.
It might be secondly hypothesized that variations in the uniform imaging of a photoconductive media should be dealt with by adjustment in the length of time during which such media is exposed, with a correspondingly correction to the exposed image areas. This very approach, or something similar, may indeed be considered to be that condition that fortuitously exists in non-impact electronic printers based on Light-Emitting Diode (LED) technology. In an LED printer system a linear array of LED's the width of the paper is used to write all the points, or pixels, on a given print line at one time. Instead of being based on a complex system including a single laser, a laser beam modulator, and assorted lenses and mechanical apparatus in order to sweep a laser beam positionally, the LED printer has a so-called "Light Stick" that exposes the photo conductive media surface with a single pass along its length. Each LED either lights or remains dark depending upon the bit mapped information received for that line of the image.
Of particular pertinence to the second hypothesized solution to the present problem, in the prior art LED "Light Stick" printer an encoder attached to the drive mechanism signals to the "Light Stick" print head exactly when to start exposing the media for each line. Since the LED's have a fast response time, approximately 5 micro seconds, this system provides a fairly good control of when to initiate exposure even when the media incurs velocity variations. It is, of course, necessary that the drive mechanism positional encoder should be accurate and timely to detect the precise media position regardless of velocity variations. It is further necessary that the media should not undergo significant velocity variations during movement over the smallest increment of distance, nominally one line, which is detected by the positional encoder. Both these requirements are normally satisfied.
It is not feasible to account for instantaneous variations of the photoconductive media in a laser printer employing a swept beam technology by controlling the onset time, and/or duration, of exposure. Control of the phase and the duration of exposure, which may be readily affected within an LED-array-type non-impact electronic printer, is not feasible in a swept beam laser printer. In a swept beam laser printer the laser beam is in motion under the influence of a mechanical system, and neither the onset time, or phase, of its arrival at any particular point on the image, nor its loiter, or duration, time at such point can be readily adjusted. Consequently, the present invention also rejects the approach that the phase at which exposure commences and/or the duration of such exposure should be adjusted in order to compensate for velocity variations in a photoconductive media being exposed.
Thus it seems that at least two hypotheses, each derived from consideration of the prior art, regarding how the image uniformity problem might be attempted to be solved do not, in actual fact, suggest good solutions. Remarkably, the solution in accordance with the present invention does not deal with either the mechanical movement of the media nor with the electrical phase or duration of the exposing light beam. Since many solutions, especially good ones, seem natural once they are clearly understood, it is interesting to note that the solution in accordance with the present invention is actually quite strange in consideration of anything that could be extrapolated from a direct frontal attack on the problem by a correction of the conditions of its origin, let alone by anything that could reasonably be suggested by an extension of the prior art.
SUMMARY OF THE INVENTION
The present invention is embodied in an apparatus, and method, for compensating for undesirable variations in the image areas exposed in a photosensitive and photoconductive media due to corresponding variations in the velocity of the media when it moves past a marking system, nominally a light or laser beam, which marks the media. More particularly, the present invention is concerned with compensating for undesirable variations in the balance, or ratio, between the sizes of white and the black image areas exposed within a photosensitive media due to variations in the velocity of the media.
In accordance with the present invention, the instantaneous velocity of a photosensitive media, moving within a system for marking such media with light, is sensed. The sensed instantaneous velocity is used to proportionately adjust the light intensity of the marking system, nominally a light or laser beam, which is exposing the photosensitive media. Particularly, the light intensity of a light, or laser, marking system is adjusted to be proportionately brighter, producing a proportionately wider scan line, when it is sensed that the instantaneous velocity of the photosensitive media is proportionately faster than an average velocity of this media. The light intensity is adjusted to be proportionately dimmer, producing a proportionately narrower scan line, when it is sensed that the velocity of the photosensitive media is proportionately slower than its average velocity.
A brighter laser light intensity results in (i) an exposed scan line of increased height (and, of lessor importance, width), (ii) a image print line (area) resultant from the overlapped combination of a succession of such scan lines which is also of increased height (and also width) and, importantly, (iii) a reduction in the height of vertically adjacent image print lines (areas) sufficient to make, in combination, that the height (and area) ratio of white to black lines (areas) remains constant. Equivalently, a dimmer laser light intensity results in (i) a decreased height of an exposed scan line, (ii) a resultantly exposed image print line which is also of decreased height, and (iii) the maintenance of a constant height (and area) ratio between white and black lines (areas).
By this compensation certain undesirable variations in the ratio of white to black image areas within the photosensitive media, which variations are due to variations in its velocity past the marking light or laser beam, will be corrected. Visually detectable imperfections in the exposed images, particularly in spaced parallel horizontal line and grey scale patterns, are substantially eliminated.
In one embodiment of the present invention, the instantaneous velocity of a photosensitive media is sensed by an optical encoder. The optical encoder detects encoding on a circular disk which is affixed to a drive shaft which moves the photosensitive media pass the marking system. The sensed velocity is processed in a Velocity Error Processor, or VEP, in order to produce a signal which controls the intensity of the marking system, nominally a laser. Within this VEP a running average velocity is determined, and the instantaneous sensed velocity is subtracted from this running average velocity in order to obtain the current instantaneous variation from average. The intensity of the marking system, nominally the light intensity of the laser, is modulated proportionately to this current instantaneous variation from average velocity. The VEP may further, optionally, incorporate a fail-safe circuit for suspending the adjusting, and for enabling the continuing operation of the printer, if the sensed velocity is not a validly possible velocity. The VEP may be implemented from analog or digital electrical circuitry.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention will become increasingly clear upon reference to the drawings and accompanying specification wherein:
FIG. 1 is a block diagram showing the preferred embodiment apparatus of the present invention including a velocity sensor and a Velocity Error Processor (VEP).
FIG. 2 is a block diagram showing a first embodiment, analog, implementation of the VEP, part of the apparatus of the present invention.
FIG. 3 is a block diagram showing a second embodiment, digital, implementation of the VEP, part of the apparatus of the present invention.
FIG. 4, consisting of FIG. 4a through FIG. 4c, is a series of graphs showing effective spot size of an exposing laser beam at different velocities of the photoconductive media.
FIG. 5, consisting of FIG. 5a through FIG. 5c, is a highly enlarged view of a portion of successive white and black print lines printed without the compensating method and apparatus in accordance with the present invention for each of the three cases of normal, slow, and fast media velocity.
FIG. 6, consisting of FIG. 6a through FIG. 6c, is a highly enlarged view of a portion of successive white and black print lines printed with the compensating method and apparatus in accordance with the present invention for each of the three cases of normal, slow, and fast media velocity.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to controlling the intensity of a light, or laser, beam within a system, nominally a non-impact printer, for marking a moving photosensitive, and photoconductive, media with the beam. The controlling of intensity is directed to compensating for variations in the image areas exposed within the photosensitive media due to variations in its velocity of movement past the laser beam whereat and whereby it is so exposed. These velocity variations, and attendant variations in the exposed, or printed image will, if not corrected or compensated, produce an image that shows undesirable deviations from uniformity. Particularly, closely-spaced parallel lines which are aligned perpendicular to the direction of media motion and/or grey scale (alternating minute exposed and unexposed areas) images will appear to visually exhibit undesirable striations and other nonuniformities.
The preferred embodiment of an apparatus in accordance with the present invention is particularly configured for use in a non-impact printer having a single laser beam. This laser beam is scanned transversely across a photoconductive media which is moved relative to this transverse scanning beam by a rotating drive shaft. However, the application of the present invention is not so limited. A plurality of laser, or light, beams--up to and including the linear array of a multiplicity of LED's--can be controlled in intensity in accordance with the present invention. Likewise, it is not necessary that the media be driven by (nor that its velocity be encoded from) a rotating drive shaft. The media can, instead, be moved in a linear path such as by being carried upon a belt. It is well known to detect and encode linear velocity, including by linear optical encoders. Accordingly, when the particular preferred operational interface, particular preferred environment of use, and particular preferred embodiments of the present invention are next discussed, the fundamental principles of the present invention--for controlling intensity of a media-exposing light source responsively to velocity variations in the media being exposed--should be continuously considered in order that the scope of the present invention may be fully appreciated.
The block diagram of a preferred embodiment media velocity sensor/laser intensity modulator apparatus in accordance with the present invention is shown in Figure 1. A velocity sensor includes a sensor disk 12 which is attached a drive shaft 14 which moves the photosensitive media (not shown) past a light source (not shown) whereat and by which it is exposed. The drive shaft for the photoconductive media 14 is preferably the final media drive shaft. This drive shaft is physically proximate, and closely linked, to the media and to its instantaneous velocity at the point and time of its exposure. For example, drive shaft 14 would be a shaft of a drum if the photoconductive media is on a drum.
Continuing with the velocity sensor 10 shown in FIG. 1, the sensor disk 12 can either be a clear optical disk exhibiting very fine radial rulings, or a magnetic disk (similar to a floppy disk for a computer) with closely spaced flux reversals written uniformly in around a circumferential track, or equivalent devices. The sensor pick up 16 can be either a light source and an accompanying optical sensor, or a magnetic sensor (similar to a floppy disk head or a tape recorder head), or equivalent sensors as befit the type of sensor disk 12 which is employed. Incremental optical rotary encoders are available from many manufacturers including Hewlett Packard, Dynamics Research Corporation, and the Instrument Division of Dresser Industries. A particularly high performance optical encoder, directed to positional encoding but also usable for the detection of angular velocity, is taught in copending U.S. patent application Ser. No. 07/043,167 for Optical Position Encoder to David J. Shelander and assigned to the same assignee as the present invention.
The signal from the sensor pickup 16 is optionally amplified in sensor amplifier 18 before being processed by the Velocity Error Processor (VEP) 20,21. The sensor amplifier 18 is often packaged integrally with the sensor pickup 16, and is readily realized from a operational amplifier.
The signal developed by the velocity sensor 10 is indicative of the velocity of the media, substantially the instantaneous velocity since the sensor and its electronics respond exceedingly fast to minute changes in the velocity of the media as mechanically transported. This velocity signal 19 is communicated to Velocity Error Processor (VEP) 20,21. The VEP shown in block diagram in FIG. 1 bears the two identification numerals "20,21" because an analog embodiment VEP 20 will be shown in FIG. 2 while a digital embodiment 21 will be shown in FIG. 3, both embodiments having the same block diagram which is shown in FIG. 1.
The VEP 20,21 first determines in valid sensor output detector 30 if the sensor signal 19 is valid. If the sensor signal 19 is not valid, then the output of the VEP is disabled by the output gate 70. This provides a "fail-soft" mode of operation of the VEP 20,21 that allows the laser modulator and printer (not shown) which interface to the VEP 20,21 to operate normally, without any intensity compensation, in case of a failure in the velocity sensor 10. Both the average velocity and instantaneous velocities are respectively determined by the average velocity detector 50 and the instantaneous velocity detector 40. It is not necessary that the average velocity--which is preferably a running average velocity and is more preferably a weighted running average velocity with the historical sensed velocities more heavily weighted in accordance with their proximity to the present time--should be detected or developed. A predetermined constant average velocity will suffice for operation of the VEP 20,21. However, an average velocity detection, or determination, allows that long term variations in the drive velocity of the media may be accommodated, and that the VEP 20,21 will "renormalize" at a new long term average media velocity. This might be useful if, for example, there were two or more different speeds of media transport which were associated with differing media, differing intended average exposures of the same media (contrast or light/dark scale variation), or the like.
Continuing in the block diagram of the VEP 20,21 shown in FIG. 1, the difference between that signal representative of instantaneous velocity which is developed in instantaneous velocity detector 40, and that signal representative of average velocity which is developed in average velocity detector 50, is the instantaneous velocity error signal. This instantaneous velocity error signal is developed in subtracter 60. If, by action of the valid sensor output detector 30, this instantaneous velocity error signal is enabled to pass through output gate 70, then it will be communicated as a input, control, signal to the light, or laser, intensity control circuitry. The effects of any absolute velocity or sensor errors, and the requirements for careful factory and field calibration, are eliminated by the preferred embodiment implementation of the VEP 20,21 wherein the instantaneous velocity error signal is constantly calculated as a deviation from (running) average media velocity, and not merely as a deviation from some predetermined and fixed velocity.
The preferred embodiment VEP 20,21 in accordance with the present invention is capable of being implemented in both analog electronics and digital electronics. An analog embodiment of the VEP 20 is shown in block diagram form in FIG. 2. A one-shot, or monostable, multivibrator 25 produces a fixed width pulse responsively to the sensor signal 19 received from the velocity sensor 10 (shown in FIG. 1). The frequency of the pulses produced by the one-shot 25 varies with the rotational velocity of the media drive shaft and the sensor disk 12 (shown in FIG. 1). Therefore, the average dc value of the output signal of the one-shot 25 is proportional to the rotational velocity of the sensor disk 12.
Two RC filter networks are connected to the one-shot output: one fast filter network 41 with a relatively fast time constant and one slow filter network 51 with a relatively slow time constant. The signal output of the fast filter network 41 represents the instantaneous velocity of the media, and the signal output of the slow filter network 51 represents the average velocity of the media. The difference between these two signals is determined by an analog subtracter 61 which is made from an operational amplifier and several resistors. The output of the analog subtracter 61 is gated by an analog gate 72. The analog gate 72 is controlled by a logic ANDing in AND gate 71 of a timing enable from the laser control circuitry and of a signal output of pulse stretcher (one-shot) 32. The pulse stretcher 32 is driven by a missing pulse detector and pulse width checker 31, both of which use one-shot multivibrators. These one-shots will disable the output gate 72 of the VEP 20 for a fixed period of time if the input pulses developed in one-shot 25 are out of a predetermined specification.
A digital embodiment of a Velocity Error Processor (VEP) 21 in accordance with the present invention is shown in block diagram in FIG. 3. The digital implementation of VEP 21 is more complex than the analog implementation of VEP 20 shown in FIG. 2, but provides significantly more flexibility in both the correction algorithms and in criteria for disabling the output gate of the VEP 21. In the digital embodiment of VEP 21, a microprocessor 80 executes a microcoded program which is stored in program memory, or PROM, 83. The microprocessor 80 is interrupted every time there is an output from the velocity sensor 10 (shown in FIG. 1). At the time of the interrupt, the microprocessor 80 reads the contents of the counter 81, and then clears this counter 81. The counter 81 is continuously and independently increments by the microprocessor oscillator. The value read from the counter 81 by the microprocessor 80 at the time of the interrupt is proportional to the time between interrupts (i.e., the time between pulses from the velocity sensor 10).
The average velocity is calculated by the microprocessor 80 and stored in the RAM 82. From this average velocity data (processed and stored from successive readings of counter 81), and from the current velocity which is determined by the current reading of counter 81, the microprocessor 80 calculates the value of the light, or laser, intensity correction. It should be noted that the value read from counter 81 is inversely proportional to the photoconductive media velocity. The microprocessor 80 transfers the calculated intensity correction value to a digital to analog converter (DAC) 84. The DAC 84 provides an analog output voltage signal which is gated to the laser intensity control by the analog gate 73.
The enable input signal for the analog gate 83 is developed by a logic ANDing within AND gate 74. This ANDing is of the timing enable from the laser control circuitry and an enable from the microprocessor routed via control latch 85. The microprocessor 80 keeps track of the number of valid and invalid inputs (interrupts) from the velocity sensor 10 (shown in FIG. 1) and will disable the analog gate 73 if it cannot provide an accurate intensity correction signal to the light, or laser.
The explanation as to why the apparatus, and method, in accordance with the present invention successfully operates to ensure print image uniformity is the subject of the remainder of this specification. For the purposes of this explanation it will be arbitrarily chosen that the area exposed by the laser beam prints white. This is routinely accomplished in laser printers wherein the laser beam discharges certain regions of a photoconductive media. The toner will adhere to the areas not discharged by the laser. A white image is thereby caused to be printed in areas exposed by the laser beam while a black image is caused to be printed in all other areas. It should be understood that some laser printers function oppositely. In these laser printers the photosensitive media and toner are charged in such a way that the toner will adhere to the areas exposed by the laser beam, thereby printing black in these areas. The apparatus and method of the present invention is equally applicable to both positive and negative imaging, and the following explanation is directed to the one type of laser printer that prints white in the laser-exposed areas only by example, and in simplification of the explanation.
The energy distribution (in a one arbitrary dimension) about the point where the laser is focused is shown in each of FIGS. 4a-4c. The energy distribution is more or less a Gaussian curve such as appears in each Figure. Light intensity in the vertical axis is plotted relative to displacement in any direction in the plane of the photoconductive media from that one point, or center spot, whereat the laser is (momentarily) focused in the plane of the media.
A charged photoconductive media requires an impingement of a certain amount of light for a certain amount of time in order to discharge it to the state where it will print an opposite color (by example, white) to that color (by example, black) that would otherwise be printed by a fully charged media. There is a threshold region, dependent on both the time of exposure and the level of exposure, that separates whether the media will be charged or discharged after exposure.
The striped band 90 shown in FIG. 4a is such a threshold region for a fast-moving media, and the corresponding effective exposed spot size is given by dimension 91. In regions of the Gaussian curve above the band 90 the fast-moving media is fully discharged by the laser beam, and in regions of the Gaussian curve below the band 90 the fast-moving media remains charged. Within the band 90 itself there is uncertainty as to whether or not the media will be sufficiently discharged so as to print white, or will remain charged and print black. (However, despite the uncertainty, one condition of the other will hold sway and grey will not be printed.) Similarly, the striped band 92 shown in FIG. 4a is an alternative threshold region for a slow-moving media, and the corresponding effective exposed spot size is given by dimension 93. In regions of the Gaussian curve above the band 92 the slow-moving media is fully discharged by the laser beam, and in regions of the Gaussian curve below the band 92 the slow-moving media remains charged. Within the band 92 itself there is uncertainty as to whether or not the media will be sufficiently discharged so as to print white, or will remain charged and print black. Obviously the effective exposed spot size is larger for a slow-moving media (dimension 93) than for a fast-moving media (dimension 91).
If the media slows down, then less light will be required to discharge the media because the beam dwells longer at each location on the media. If the laser intensity remains constant, the effective spot size will increase as shown in FIG. 4a for a slow-moving media and will shrink for a fast-moving media. This variation in the laser spot size affects both horizontal and vertical size of printed features. This effect may be corrected by changing the laser intensity as the velocity of the photoconductive media (the drum speed) changes. This is illustrated in FIG. 4b wherein Gaussian curve 94 represents a laser beam of relatively lower intensity or power while Gaussian curve 95 represents the same laser beam at higher intensity, or power. At a same, constant, media velocity the striped band 96, locating the threshold region above which the media will be discharged and below which the media will remain charged, defines an effective exposed spot size of relatively smaller dimension 97 on the relatively lower laser intensity curve 94, and of relatively larger dimension 98 on the relatively higher laser intensity curve 95.
Applying the teaching of FIG. 4b to the practical intensity control necessary to counteract the variation in effective exposure spot size (only, and it should be remembered that other effects are operating) with media velocity changes is shown in FIG. 4c. The threshold region between media discharge and charge retention for a slow-moving media is shown by striped band 101. At this rate of media movement the intensity of the exposing laser beam is controlled to be as represented by Gaussian curve 100, causing that the effective exposed spot size is of dimension 99. The threshold region between media discharge and charge retention for a fast-moving media is shown by striped band 103. It is displaced higher in laser light intensity from band 101 because the media will not spend so long a time under the exposing laser light. At this rate of media movement the intensity of the exposing laser beam is controlled to be as represented by Gaussian curve 102, causing that the effective exposed spot size is again of dimension 99. By this manner of variation in the intensity of the exposing laser light beam the undesirable variations in image uniformity that are due (solely) to variations in effective exposure spot size with media velocity changes are corrected for, and eliminated.
The variations in image uniformity due to exposure spot size are not, however, the sole source of such variations. Variations in print image uniformity also arise because of overlapping between successive scan lines during image generation. A diagrammatic, conceptualized, representation of the results on this problem from operation of the media velocity sensor/laser intensity modulator apparatus in accordance with the present invention is shown in FIGS. 5 and 6, each consisting of parts a through c. The representation within each of FIGS. 5 and 6 is of a greatly magnified small area of alternating white and black print lines. A white print line consists of several, for example three (3), successive partially overlapping scan lines within which the light, or laser, beam is turned on, thereby exposing the photosensitive media. A black print line consists of several, for example 5, successive partially overlapping scan lines within which the light, or laser, beam is not turned on, thereby leaving the photosensitive media unexposed. The appearance of such, printing respectively without and with benefit of the compensation enabled by operation of the apparatus and method of the present invention is conceptually illustrated, with exaggeration for the sake of clarity, in respective FIGS. 5 and 6.
Within both FIG. 5 and FIG. 6 the printing, accomplished by exposure of a photosensitive media, proceeds from top to bottom with a movement of the media being in the opposite direction. If the printing is done by a scanning beam, then the transverse motion of this beam may additionally cause that the printing is also being performed right-to-left, or left-to-right, or bidirectionally. This motion, if any, is of no consequence to the operation of the present invention. In order that the effects of the present invention may be best observed, it is illustrated that the media does not move with a steady velocity. The amount of media movement is indicated by vertically arrayed "tick marks" 100,101,102 (which have no actual real, physical, basis but which are merely indications on a scale) respectively to the left of FIGS. 5a and 6a, 5b and 6b, and 5c and 6c. In each of FIGS. 5a and 6a the media moves at its nominal, average, velocity which corresponds to "tick marks" 100 denoting this movement which are at an arbitrary separation which will be defined as two (arbitrary) units of distance. In each of FIGS. 5b and 6b the media moves with a reduced velocity, indicated by "tick marks" 101 to be one distance unit per (arbitrary) time interval. Finally, in FIG. 5c and 6c the media moves with an increased velocity, illustrated by the separation of "tick marks" 102 to be three distance units per time interval. In actual operation of a printer, such extreme, 50%, velocity variations would not be anticipated. However, FIGS. 5 and 6 are exaggerated in order to more clearly show the operation of the present invention.
Centered about each "tick mark" 100,101,102 in FIGS. 5 and 6 is an indicated vertical height which constitutes one scan line. This height of a scan line is illustrated by a solid vertical line, for example lines 110 shown in FIG. 5, when the laser is turned on, exposing the photosensitive media and writing what is nominally the white image. The scan lines, and scan line heights, are illustrated by dashed vertical lines for all "tick mark" positions wherein the laser is turned off, not exposing the photosensitive media and "writing" a black image. These dashed-line laser-off scan lines, for example scan lines 111 shown in FIG. 5, are of equal vertical extent to the solid-line laser-on scan lines, for example scan lines 110 shown in FIG. 5. The scan lines are not actually horizontally displaced one to the next, it being understood that FIGS. 5 and 6 are diagrammatic only.
There is an overlap between scan lines. In identical FIGS. 5a and 6a this overlap is illustrated to be 50%, or one distance unit, when the media is moving at nominal average velocity, or two distance units between successive tick marks. At this media velocity (two units) and degree of overlap between successive scan lines (50%, or one unit) then three laser-on scan lines 110 followed by five laseroff scan lines 111 will produce that identical height (eight units) between exposed, white, print line 120 and unexposed, black, print line 121 which is illustrated in FIGS. 5a and 6a. Note that the number of scan lines during which the laser is turned on (three) is not equal to the number of scan lines within which the laser is turned off (five) because the media only needs to be exposed but once, meaning that white overwrites black in image formation.
The operation of a laser printer, scanning or not so long as the height of scan-equivalent lines is maintained constant, when the photosensitive media slows by 50%, to one unit per "tick mark" is shown in FIG. 5b. The height of the white print line 122 is diminished to six units, but the height of the black print line 123 is even more severely diminished to two units. The ratio of white to black print line heights has changed from 1:1 to 3:1. It is this change, more than the absolute change in heights, which is acutely discernible by the human eye. The printed area has become much lighter overall.
The equivalent operation of the laser printer operating without benefit of the present invention when the media velocity increases 50% from average, to three units per "tick mark" is shown in FIG. 5c. The height of the printed white line 124 increases 25% to ten units but the height of the black print line 125 increases 50% to twelve units. The ratio of white to black pint line heights changes from 1:1 to 5:6. Although not as severe as the change resultant from a slowing of the print media velocity, this change is still undesirable and potentially shows to the human eye as an overall darkening of the printed area.
The effect of operating a scanning light printer in accordance with the apparatus and method of the present invention is shown in FIGS. 6b and 6c. It is illustrated in FIG. 6b that the media velocity slows 50% to one unit per "tick mark", identically as in FIG. 5. However, by operation of the present invention, the intensity of the laser beam exposing the photosensitive (discharging the photoconductive) media is proportionately reduced by 50%. It is a characteristic of light discharge of a photoconductive media (light exposure of a photosensitive media) that the height of the strip, band, or scan line discharge will be approximately proportional to the intensity of the discharging light beam. Consequently, the laser-on scan lines 112 shown in FIG. 6b are illustrated to be reduce 50% in height, from four units to two units. The laser-off scan lines 113 are illustrated to be correspondingly reduced, but this is only arbitrary for the sake of symmetry of illustration. The laser-off scan lines can be envisioned to remain at four units height, if desired: since white overwrites black it makes no difference. The effect of the intensity compensation in accordance with the present invention may be observed in FIG. 6b to produce a white print line 126 and a black print line 127 of equal height of four units. The ratio of white to black image area has not changed from the original 1:1 and the eye is satisfied. This is true even though both the white and the black lines have become 50% thinner.
Finally, the effect of the intensity compensation in accordance with the present invention upon a 50% slowing of the velocity of the photosensitive media may be observed in FIG. 6c. Therein a laser-on scan line 114 of 50% greater height, or six units, and a laser-off scan line 115 may be observed to produce a white print line 126 and a black print line 127 which are of equal twelve unit height. The ratio of white to black image area has not changed from the original 1:1 and the eye is satisfied. This is true even though both the white and the black lines have now become 50% thicker.
The operation of the present invention is equivalent in the printing of grey scale. An actual laser printer might be capable of printing 1200 dots, or pixels, per inch in the horizontal direction and 2400 in the vertical direction. A very fine grey scale, not resolvable (or barely resolvable) with the naked eye, which is printed with such a printer might consist of alternating squares of 5 dots, or pixels, in the horizontal direction by 10 dots, or pixels, in the vertical direction, or squares of 1/120 inches on a side. Those real and actual, visually perceptible, imperfections which occur in the printing of an actual grey scale due to variations in the velocity, and resultant exposure, of a photosensitive media cannot exactly be extrapolated from the much magnified, and much exaggerated, appearance of FIGS. 5 and 6. However, FIGS. 5b and 5c do hint in their nonuniformity that something might be imperfect in the printing of a grey scale image in a scanning laser printer not incorporating the present invention. This is indeed the case, with the actual, normal scale, gray scale image essentially showing horizontal (row-oriented) black/white intensity variations, or striations. Similar to the compensatory effect illustrated in FIG. 6 for the printing of closely space horizontal lines, the present invention also significantly ameliorates prior problems experienced with the printing of grey scale.
In accordance with the preceding discussion, the present invention will be recognized to have diverse aspects, and embodiments, directed to compensating for media-velocity-variation-induced variations in the image formed on a moving photosensitive media by dynamically adjusting the intensity of the exposing light, or laser, beam. Correspondingly, the present invention should be defined by the scope of the following claims, only, and not solely in consideration of those embodiments within which the invention has been taught.
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A photosensitive, photoconductive media moving in a first direction relative to a laser light beam scanning in a second direction, transverse to the first direction, incurs velocity variations. These velocity variations result in variations in the absolute and relative heights of white and black image features. This printed image nonuniformity is especially visually detectable for closely spaced parallel lines in the second direction, and/or gray scale. An optical velocity sensor senses instantaneous media velocity. An analog or digital velocity error processor maintains a running average velocity and determines, by subtraction, an instantaneous velocity error as the difference between currently sensed and running average velocities. The instantaneous velocity error so determined is used to adjust the intensity of the laser light beam to be proportionally brighter (dimmer), exposing a wider (narrower) scan line, on a faster-moving (slower-moving) media region. By this compensating, the ratio of white and black image features is maintained constant during media velocity variations.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to specific, improved spun-bonded nonwoven fabrics comprised of continuous multi-component longitudinally splittable fibers. The resulting nonwoven fabrics exhibit enhanced flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness in comparison with other nonwovens of the same fiber construction. These improved aesthetic and performance characteristics permit expansion of high-strength nonwoven fabric materials into other markets and industries currently dominated by woven and knit fabrics that exhibit such properties themselves, but at high cost and requiring greater manufacturing complexity. Such enhanced fabrics are subjected to certain air impingement procedures, for instance through directing low-pressure gaseous fluids at high velocity to the surface of the targeted nonwoven fabric. Also encompassed within this invention is the method of treating such a specific nonwoven fabric with this air impingement procedure.
[0002] Nonwoven textile articles have historically possessed many desirable attributes that led to their use for many items of commerce, such as within air filters, furniture linings, and automotive parts, such as vehicle floorcoverings, side panels, and molded trunk linings. Such nonwovens have proven to be lightweight, inexpensive, and uncomplicated to manufacture, among various other advantages.
[0003] Recently, technological advances in the field of nonwovens, such as improved abrasion resistance and wash durability, have expanded the markets for such materials. For example, U.S. Pat. Nos. 5,899,785 and 5,970,583, both assigned to Firma Carl Freudenberg, describe a nonwoven lap of very fine continuous filament and the process for making such nonwoven lap using traditional nonwoven manufacturing techniques. Such references disclose, as important raw materials, spun-bonded composite, or multi-component, fibers that are longitudinally splittable by mechanical or chemical action. Furthermore, patentees indicate the ability to subject a nonwoven lap, or fabric, formed from such materials to high-pressure water jets (i.e., hydroentanglement). This further treatment causes the composite fibers (which are typically microdenier in size) to partially separate along their lengths and become entangled with one another, thereby imparting strength to the final product. As an example, Freudenberg currently commercializes at least one product, Evolon®, made by this process, and it is available in standard or point-bonded variations. (The standard variation has not been subjected to further bonding processes, such as point bonding. Point-bonding is the process of binding thermoplastic fibers into a nonwoven fabric by applying heat and pressure so that a discrete pattern of fiber bonds is formed.) Additionally, U.S. Pat. No. 6,200,669, assigned to Kimberly-Clark Worldwide, Inc., describes yet another process for fabricating spun-bonded nonwoven webs from continuous multi-component fibers that are longitudinally splittable by the process of hydroentanglement.
[0004] These manufacturing techniques permit efficient and inexpensive production of nonwoven fabrics having characteristics and properties, such as, for example, mechanical resistance, equal to those of woven or knitted fabrics. As a result, such nonwovens have penetrated markets, such as apparel, cleaning cloths, and artificial leather, which historically have been dominated by woven and knit products.
[0005] However, with the emergence of nonwovens into these new markets and increased consumer interest in such products, there has been a desire to produce fabrics with additional characteristics similar to those of woven or knitted fabrics. Some of these characteristics include increased flexibility, drape, and softness of the fabric. Historically, these attributes have been obtained subsequent to the fabric's finishing (i.e. after finishing processes which include, for example, dyeing, decorating, texturing, etc.) with some difficulty due to the fragile nature of the fabric and the ease of mark-off of any dyes, pigments, or other decorative accoutrements. Prior methods of fabric conditioning after finishing have included roughening of the finished product with textured rolls or pads, which may actually break a significant number of surface fibers. These methods, as mentioned above, may be destructive to the finished fabric because of such problems as undue weakening of the overall strength of the fabric and mark-off.
[0006] Additionally, other methods for conditioning include the use of chemicals, which can be expensive, detrimental to the environment, and irritating to the skin. Thus, a chemical-free process, which involves no contact with rough surfaces, is preferable in order to reduce or eliminate skin irritation and minimize damage to the surface of the fabric while providing optimal levels of softening and conditioning to the fabric. Commonly assigned U.S. Pat. Nos. 4,837,902, 4,918,785, 5,822,835, and 6,178,607 have identified techniques for conditioning textile webs, or fabrics, to change their aesthetic and performance qualities. Specifically, these patents disclose methods and equipment for projecting low pressure, high velocity streams of gaseous fluid against a fabric web in either the opposite or same direction substantially tangential to the web of fabric, thereby creating saw-tooth waves having small bending radii which travel down the fabric thereby breaking up, or weakening, some fiber-to-fiber bonds in the web so as to increase flexibility, drape, and softness of the fabric. An additional attribute imparted to the fabric treated by these processes of air impingement includes increased cleanliness of the fabric due to the removal of undesired fiber fly and other loose materials entrapped in the pile.
[0007] Thus, while nonwoven manufacturing technology has been identified which has allowed for the introduction of nonwoven textile fabrics into new market areas such as apparel, cleaning cloths, and artificial leather, consumer interest has spurred the need for further advances in the finishing of these fabrics in order to improve the look and feel of the fabric for emergence into additional markets and end-use products for apparel, napery, drapery, upholstery, cleaning cloths, and cleanrooms.
SUMMARY OF THE INVENTION
[0008] In light of the foregoing discussion, it is one object of the current invention to achieve a spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers, which has been mechanically modified to possess increased flexibility and drape.
[0009] A further object of the current invention is to achieve a spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers, which has been mechanically modified to possess increased softness and thickness.
[0010] It is also an object of the current invention is to achieve a spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers, which has been mechanically modified to possess increased moisture absorption capacity and moisture vapor transmission rate.
[0011] Another object of the current invention is to achieve a spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers, which has been mechanically modified to possess increased cleanliness due to the removal of loose materials trapped in the fabric.
[0012] A further object of the current invention is to achieve a spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers, which has been mechanically modified and that maintains its aesthetic appearance due to the finishing process having no physical contact with the surface of the fabric.
[0013] It is also an object of the current invention to achieve a method for mechanically modifying spun-bonded nonwoven fabrics comprised of continuous multi-component splittable fibers to impart increased flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness to the fabric.
[0014] Other objects, advantages, and features of the current invention will occur to those skilled in the art. Thus, while the invention will be described and disclosed in connection with certain preferred embodiments and procedures, such embodiments and procedures are not intended to limit the scope of the current invention. Rather, it is intended that all such alternative embodiments, procedures, and modifications are included within the scope and spirit of the disclosed invention and limited only by the appended claims and their equivalents.
DETAILED DESCRIPTION OF THE INVENTION
[0015] A spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers is provided that has been mechanically modified to achieve useful improvements in certain desired properties. U.S. Pat. Nos. 5,899,785 and 5,970,583, both incorporated herein by reference, describe one non-limiting embodiment of a starting nonwoven material and process for manufacturing the nonwoven lap, or fabric, to be mechanically modified by the previously mentioned air impingement process, thereby providing the inventive nonwoven fabrics. Typically, the nonwoven fabric is comprised of spun-bonded continuous multi-component filament fiber that has been, either partially or wholly, longitudinally split into its individual component fibers by exposure to mechanical or chemical means, such as high-pressure fluid jets. One potentially preferred non-limiting fabric composition generally comprises 65% polyester fiber and 35% nylon 6 or nylon 6,6 fiber, although other fabric compositions with varying percentages of different fiber types are within the scope of this invention. Acceptable fabrics comprise a majority of synthetic fiber, preferable all synthetic fiber, wherein the term “synthetic” is intended to include any type of fiber not available as a naturally base product. Thus, acceptable fibers include polyester, such as, for example, polyethylene terephthalate, polytriphenylene terephthalate, and polybutylene terephthalate; polyamide, such as nylon 6 and nylon 6,6, again, as merely examples; polyolefins, such as polypropylene, polyethylene, and the like; polyaramides, such as Kevlar®, polyurethanes; polylactic acid; and any combinations thereof.
[0016] The general process for manufacturing this nonwoven lap, or fabric, includes the steps of extrusion and spinning; drawing, cooling, and napping; and simultaneously or successively, bonding and consolidation. During the bonding and consolidation step, several actions occur: (i) the composite filaments are at least partially separated into their individual filaments by, for example, hydroentanglement with high-pressure water jets, (ii) the cohesion and mechanical resistance of the nonwoven lap, or fabric, may be increased, for example, by thermobonding the individual filament with the lower melting point by calendering with a smooth or engraved hot roller, and (iii) ultimately, the nonwoven fabric is dried by methods such as the above-mentioned calendering step, or alternatively, merely as an example, by passage through a hot-air tunnel.
[0017] The process for mechanically treating the nonwoven fabric, which is typically comprised of polyester and nylon composite fibers, is described in commonly assigned U.S. Pat. Nos. 4,837,902, 4,918,785, 5,822,835, and 6,178,607, which are incorporated herein by reference. These patents describe fabric conditioning processes that project low pressure, high velocity streams of gaseous fluid against the fabric web in various directions compared to the direction of fabric web flow substantially tangential to the web of the fabric, thereby creating saw-tooth waves having small bending radii which travel down the fabric thereby breaking up, or weakening, some fiber-to-fiber bonds in the web so as to increase flexibility, drape, and softness of the fabric. The streams of gaseous fluid may be directed against the fabric in the same direction as fabric web flow, opposite the direction of fabric web flow, simultaneously in both directions, or successively in both directions of fabric web flow. One opening, or a plurality of openings may deliver the streams of gaseous fluid. Generally, the fabric is exposed to a high velocity vibration technique. In relation to this invention, it has been realized, surprisingly, that such a treatment procedure imparts additional attributes to the target nonwoven fabric including increased fabric thickness, moisture absorption capacity, and moisture vapor transmission rate all for the benefit of allowing the expanding uses of such nonwoven materials.
[0018] It is contemplated that all these attributes generally result from the break-up of some of the fiber-to-fiber bonds in the nonwoven fabric web, as well as from the additional splitting of the composite fibers into their individual components. Such results are not generally available to the same degree with woven and knit fabrics. A further benefit resulting from this air impingement process is the increased cleanliness of the fabric in terms of residual, loose surface fibers retained thereon because the process ultimately loosens and removes fiber fly, lint, and other undesirable materials from the fabric. This feature is important for aesthetic reasons in most fabric applications, but it also has functional use in end-use products for cleanrooms where even the smallest particle of lint from a fabric can cause irreversible damage, for example, to highly delicate silicon wafers.
[0019] In one potentially preferred embodiment of the current invention, the air impingement treatment equipment is installed in-line with the nonwoven manufacturing process such that the nonwoven fabric is exposed to air impingement treatment following the hydroentanglement step of the nonwoven production process while the fabric is still wet. The nonwoven fabric is typically treated by air impingement on one side of the fabric, although it is contemplated to be within the scope of this invention that the fabric may be treated by air impingement on both sides of the fabric. Following treatment with air impingement, the wet fabric is then bonded and dried by processes described above, such as thermobonding the lower melting point filament. The fabric may then be dyed or printed and exposed to further finishing processes according to techniques known to those skilled in the art.
[0020] Another potentially preferred embodiment of the current invention involves exposing the nonwoven fabric to the air impingement process after the bonding and consolidation step of the production process. To this end, the air impingement process may be installed in-line with the nonwoven production process such that the fabric is treated immediately as it exits the production line, or it may be treated separately from the production line. In relation to this invention, it has been realized, unexpectedly, that the dyed fabric tends to exhibit a slightly lighter shade of color than a dyed nonwoven control fabric that is not treated by the air impingement process. Without being bound by theory, this suggests that the air impingement process opens up the dense fiber-to-fiber construction of the fabric and creates available space, which allows dyes to further penetrate to fibers deep within the treated dyed fabric. In contrast, the untreated dyed fabric likely has less available open space and less penetration of dye into the interior of the fabric leaving a higher concentration of dye on the surface of the fabric, thereby creating a fabric that is slightly darker in color.
[0021] A further potentially preferred embodiment of the current invention involves exposing the nonwoven fabric to the air impingement process after the fabric has been dyed, printed, sanforized, or further modified by finishing processes known to those skilled in the art.
[0022] An advantage of producing a nonwoven fabric according to the method described herein includes the consolidation of process steps by incorporating the air impingement process in-line with the nonwoven production process. Typically, manufacturers would likely incur cost savings by such consolidation of process steps, as well as through complexity reduction via simplified production layouts and organizations, as well as through reductions in required time allocation (e.g., by eliminating the need to take the fabric off the original production line, move it, and tie it into a separate line for air impingement treatment). However, it may be necessary, and is contemplated within the scope of the invention described herein, to treat the fabric by air impingement separate from the production line because further advantages may be gained, for example, by manufacturing the nonwoven fabric, treating it chemically to impart certain properties, dyeing the fabric, and then exposing the finished product to desired and unexpectedly beneficial air impingement.
[0023] A further advantage of the current invention is the flexibility of process step sequences and/or arrangements. For example, the fabric may be treated by air impingement: (i) during the nonwoven production process via an in-line arrangement; (ii) after the nonwoven production process either in-line or separate from the production process; (iii) before the fabric has been dyed, printed, or further modified by chemical or mechanical finishing processes; or (iv) after the fabric has been dyed, printed, or further modified by chemical or mechanical finishing processes. This advantageous flexibility permits a manufacturer to choose the process which best optimizes one of the many enhancements imparted to the nonwoven fabric for a particular end use, as well as to possibly determine the best configuration, from an efficiency perspective, for his own manufacturing operations and retain the ability to produce such beneficial inventive nonwoven fabrics.
[0024] Other advantages of producing a nonwoven fabric according to the method described herein include the many enhanced characteristics possessed by the fabric. These characteristics include increased flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness. Consumer interest has accelerated the need for nonwoven fabrics to possess these types of characteristics, which are similar to woven or knitted fabrics, for end uses in apparel, drapery, napery, upholstery, cleaning cloths, and cleanroom markets.
[0025] A further advantage of the nonwoven fabric produced according to the present invention is that is has application for use as an allergy barrier. This fabric is characterized by a highly dense construction due to the microdenier size of the individual fibers that have been split during the production process. The dense nature of this fabric allows it to act as a filter to small allergy causing materials. Other nonwoven fabrics used as allergy barriers are typically comprised of multiple layers of fabric and film laminated together for that purpose (e.g., as taught within U.S. Pat. No. 6,017,601) such that one layer provides a film barrier, while another layer provides textile-like properties. These laminated nonwoven allergy barriers generally exhibit short useful lives because they often delaminate after repeated use or wash cycles. Conversely, the fabric of the current invention may be ideal for use as an allergy barrier without requiring lamination to additional layers of fabric or film, thereby avoiding the aforementioned potentially deleterious delamination problem. For example, a single layer of this fabric may be exposed to the air impingement treatment process described herein to achieve a fabric having improved softness, drape, flexibility, etc. Accordingly, the resulting fabric may be ideal for use as an allergy barrier in bedding applications or any other applications where such allergy barriers are useful.
[0026] Another advantage of the nonwoven fabric produced according to the present invention is that it possess enhanced characteristics such as increased flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness, which are imparted to the fabric without the use of chemicals which may be expensive, irritating to the skin, and detrimental to the environment.
[0027] The following examples illustrate various embodiments of the present invention but are not intended to restrict the scope thereof.
[0028] All examples utilized spun-bonded nonwoven fabric comprised of continuous multi-component splittable fibers which have been exposed to the process of hydroentanglement with high-pressure water to cause the multi-component fibers to split, at least partially, along their length into individual polyester and nylon 6,6 fibers, according to processes described in the two Freudenberg patents earlier incorporated by reference. The fabric, known by its product name as Evolon®, was obtained from Firma Carl Freudenberg of Weinheim, Germany.
[0029] Some of the fabrics described in the examples below were tested using the Kawabata Evaluation System (“Kawabata System”) installed at the Textile Testing Laboratory at Milliken Research Corporation in Spartanburg, S.C. The Kawabata System was developed by Dr. Sueo Kawabata, Professor of Polymer Chemistry at Kyoto University in Japan, as a scientific means to measure, in an objective and reproducible way, the “hand” of textile fabrics. This is achieved by measuring basic mechanical properties that have been correlated with aesthetic properties relating to hand (e.g. smoothness, fullness, stiffness, softness, flexibility, and crispness), using a set of four highly specialized measuring devices that were developed specifically for use with the Kawabata System. These devices are as follows:
[0030] Kawabata Tensile and Shear Tester (KES FB1)
[0031] Kawabata Pure Bending Tester (KES FB2)
[0032] Kawabata Compression Tester (KES FB3)
[0033] Kawabata Surface Tester (KES FB4)
[0034] KES FB1 through 3 are manufactured by the Kato Iron Works Col, Ltd., Div. of Instrumentation, Kyoto, Japan. KES FB4 (Kawabata Surface Tester) is manufactured by the Kato Tekko Co., Ltd., Div. of Instrumentation, Kyoto, Japan. Care was taken to avoid folding, wrinkling, stressing, or otherwise handling the samples in a way that would deform the sample. The fabrics were tested in their as-manufactured form (i.e. they had not undergone subsequent launderings.)
[0035] The Kawabata Pure Bending Tester (KES FB2) was the selected test performed on some of the fabric samples described in the examples below. The testing equipment was set up according to the instructions in the Kawabata Manual. The Kawabata Bending Tester was allowed to warm up for at least 15 minutes before being calibrated. The tester was set up as follows:
[0036] Sensitivity: 2 by 1
[0037] Sample Size: 8 inches by 8 inches
[0038] The bending test measures the resistive force encountered when a piece of fabric that is held or anchored in a line parallel to the warp or filling is bent in an arc. For purposes of this testing, the warp direction was determined to be the machine direction of the fabric (i.e., the direction in which the fabric entered and exited the production equipment as it was manufactured), and the fill direction was estimated to be perpendicular to the warp, or machine, direction of the fabric. The fabric is bent first in the direction of one side and then in the direction of the other side. This action produces a hysteresis curve since the resistive force is measured during bending and unbending in the direction of each side. The width of the fabric in the direction parallel to the bending axis affects the force. The test ultimately measures the bending momentum and bending curvature. The following quantities are directly measured:
[0039] X=curvature K [cm −1]
[0040] Y=bending momentum [gf-cm]
[0041] The final hysteresis at a given K is the average of the corresponding hysteresis values for the forward and backward parts of the graph, i.e., at±K.
[0042] The formulas for calculating the bending quantities are given below:
[0043] L1=width [cm] of fabric in direction parallel to the bending axis the nominal value is 20 cm.
B = a ′ + b ′ 2 × 1 L1 [ gf - cm 2 / cm ]
[0044] where a and b have units of gf-cm/cm −1 and where
a ′ = a 1.5 - 0.5
[0045] is the slope of Upper Forward branch between K=0.5 and K=1.5
b ′ = b 1.5 - 0.5
[0046] is the slope of Lower Backward branch between K=−0.5 and K=−1.5
2 HB05 = e + g 2 × 1 L1 [ gf - cm / cm ]
[0047] where e and g have units of gf-cm
2 HB10 = c + d 2 × 1 L1 [ gf - cm / cm ]
[0048] where c and d have units of gf-cm
2 HB15 = f + h 2 × 1 L1 [ gf - cm / cm ]
[0049] where f and h have units of gf-cm
[0050] Bending Stiffness (B)—Mean bending stiffness per unit width [gf-cm 2 /cm]. Lower value means a more supple hand.
[0051] Bending hysteresis (2HB05)—Mean width of bending hysteresis per unit width at K=0.5 cm −1 [gf-cm/cm]. Lower value means the fabric recovers more completely from bending.
[0052] Bending hysteresis (2HB10)—Mean width of bending hysteresis per unit width at K=1.0 cm −1 [gf-cm/cm]. Lower value means the fabric recovers more completely from bending.
[0053] Bending hysteresis (2HB15)—Mean width of bending hysteresis per unit width at K=1.5 cm −1 [gf-cm/cm]. Lower value means the fabric recovers more completely from bending.
EXAMPLE 1
[0054] The following example shows treatment of the Evolon® fabric with the air impingement process in a laboratory setting.
[0055] Standard (rather than point-bonded) Evolon® fabric at 160 g/m 2 was subjected to a laboratory simulation of the air impingement process as described in the commonly assigned U.S. patents earlier incorporated by reference. Air pressure at 80 psi was delivered by one opening, or slot, to both sides of a piece of fabric, approximately 65 inches by 15 inches, for about 60 seconds. Four 8 inch by 8 inch samples (Samples A-D) were then cut from the treated fabric and tested using the Kawabata Pure Bending Tester. The warp direction was determined to be the machine direction of the fabric when it was manufactured, and the filling direction was estimated to be perpendicular to the warp, or machine direction. A ratio of fabric weight-to-Bending Stiffness (B) was also calculated, i.e. Ratio: Wt/(B). The results are shown in Tables 1A and 1 B below.
TABLE 1A Comparison of Kawabata Pure Bending Tester Results in Warp Direction A B C D Avg STD ERR Untreated Nonwoven Fabric 160 g/m 2 B 2.392 2.704 2.528 2.856 2.620 0.203 +/−0.322 2HB05 0.789 0.718 0.754 0.547 0.702 0.107 +/−0.171 2HB10 1.107 1.160 1.163 1.085 1.129 0.039 +/−0.062 2HB15 1.087 1.169 1.140 1.175 1.143 0.040 +/−0.064 Ratio: 66.9 59.2 63.3 56.0 61.1 Wt/(B) Treated Nonwoven Fabric 160 g/m 2 B 0.636 0.700 0.855 0.631 0.706 0.105 +/−0.166 2HB05 0.324 0.486 0.431 0.415 0.414 0.067 +/−0.107 2HB10 0.411 0.539 0.565 0.483 0.500 0.068 +/−0.108 2HB15 0.441 0.531 0.584 0.474 0.508 0.063 +/−0.100 Ratio: 251.6 228.6 187.1 253.6 226.6 Wt/(B)
[0056] [0056] TABLE 1B Comparison of Kawabata Pure Bending Tester Results in Filling Direction A B C D Avg STD ERR Untreated Nonwoven Fabric 160 g/m 2 B 1.150 1.257 1.557 1.724 1.422 0.265 +/−0.421 2HB05 0.310 0.338 0.433 0.330 0.353 0.055 +/−0.087 2HB10 0.454 0.507 0.633 0.602 0.549 0.083 +/−0.132 2HB15 0.535 0.541 0.649 0.697 0.606 0.080 +/−0.128 Ratio: 139.1 127.3 102.8 92.8 112.5 Wt/(B) Treated Nonwoven Fabric 160 g/m 2 B 0.436 0.323 0.414 0.341 0.379 0.055 +/−0.087 2HB05 0.272 0.209 0.247 0.253 0.245 0.026 +/−0.042 2HB10 0.308 0.250 0.290 0.272 0.280 0.025 +/−0.039 2HB15 0.328 0.245 0.299 0.268 0.285 0.036 +/−0.058 Ratio: 367.0 495.4 386.5 469.2 422.2 Wt/(B)
[0057] Several observations can be made regarding the data in Tables 1A and 1 B. First, the treated samples exhibit lower Bending Stiffness (B) and Bending Hysteresis (2HB05-15) than the untreated, or greige, samples for both the warp and fill estimated directions. This suggests that the treated fabric is, overall, more supple and recovers more quickly from bending than the untreated samples. Additionally, the ratio of fabric weight-to-Bending Stiffness is greater for all of the treated samples when compared to the untreated samples. The ratio for the treated samples is about 187 or greater. These results demonstrate the effectiveness of treating the spun-bonded nonwoven fabric to improve the fabric's flexibility and drape, in comparison to the untreated samples, which are important attributes for end-use products such as apparel, napery, drapery, and upholstery.
EXAMPLE 2
[0058] Example 1 was repeated, and the fabric was tested for thickness. The thickness of the fabric was determined using a Thwing-Albert VIR Electronic Thickness Tester (Model No. 89-II-S) according to ASTM D 1777-96.
[0059] The untreated greige fabric measured 23.63 mils in thickness, while the treated greige fabric measured 28.98 mils in thickness. These results suggest that by treating both sides of the 160 g/m 2 fabric with low-pressure air at high velocity, the thickness of the fabric may be increased by about 20 percent. This increase in fabric thickness is likely due to the loosening of composite fiber bundles in the nonwoven fabric by breaking, or weakening, some of the bonds formed during the bonding and consolidation step of the nonwoven production process. Furthermore, the increase may result, at least partially, from further splitting of the composite fibers into their individual fibers. Both of these actions result in the opening up of the fabric by creating free space between fiber bundles and between individual fibers. This increased thickness of the treated fabric has resulted in a fabric with microfiber-like softness, which is desirable in end-use products such as apparel, napery, drapery, and upholstery. Additionally, it is contemplated that, depending on the initial fabric weight, the increase in fabric thickness may vary slightly. For example, treating both sides of a lightweight fabric (i.e., a fabric having a fabric weight of less than about 160 g/m 2 ) with the air impingement process may result in about a 15 percent thickness increase that is beneficial for imparting improved softness, or hand, to the fabric. Furthermore, treating the same lightweight fabric with the air impingement process on only one side of the fabric may result in about a 10 percent increase in fabric thickness, which still provides beneficial aesthetic and performance characteristics to the fabric.
EXAMPLE 3
[0060] Example 1 was repeated, and the fabric was tested for absorption capacity. The phrase “absorption capacity” is intended to describe the capacity of the fabric to absorb water. The capacity is measured as milliliters of water per gram of fabric. Four 7 inch by 7 inch fabric samples were created whereby two of the samples were untreated (Samples A and B) and two of the samples were treated by air impingement (Samples C and D). The samples were weighed in their dry state and then placed in a beaker of water and permitted to absorb as much water as possible. The samples were then removed from the water and allowed to drip at an angle for 30 seconds. The samples were then re-weighed. The results are shown in Table 2 below.
TABLE 2 Absorption Capacity of Treated and Untreated Nonwoven Fabric Absorption Capacity Sample (ml/g) A - Untreated 3.47 B - Untreated 3.38 Untreated Avg. 3.43 C - Treated 4.47 D - Treated 4.45 Treated Avg. 4.46
[0061] Table 2 shows that treating the nonwoven fabric with the air impingement process results in a 30 percent increase in absorption capacity of the fabric. It is contemplated that an absorption capacity of about 3.75 ml/g or greater (an increase of approximately 10 percent or more) may result in some benefit for enhancing the fabric's absorption properties. This enhancement of the fabric is useful in end-use products such as sports apparel, cleaning cloths, napery, and any other applications where moisture transmission is an important feature.
EXAMPLE 4
[0062] Example 1 was repeated, except that the fabric was jet-dyed after the air impingement treatment. The fabric was dyed using disperse dyes for 30 minutes at 130 degrees C. The jet-dye was cooled to 50 degrees C. and then the fabric was rinsed twice with water. The fabric was hung to dry in an oven for 5 minutes at 350 degrees F. One 8 inch by 8 inch sample of treated and untreated fabric was then tested using the kawabata Pure Bending Tester (indicated as “A”). The fabric was also tested for shade, or color, variation using a Lab Scan XE manufactured by Hunter Labs., such that “L” indicates the whiteness of the fabric, “A” indicates the tan to green color of the fabric, and “B” indicates the yellowness of the fabric. The results are shown in Tables 3A, 3B, and 3C below.
TABLE 3A Comparison of Kawabata Pure Bending Tester Results in Warp Direction A Untreated Nonwoven Fabric 160 g/m 2 B 0.154 2HB05 0.131 2HB10 0.124 2HB15 0.117 Treated Nonwoven Fabric 160 g/m 2 B 0.110 2HB05 0.070 2HB10 0.066 2HB15 0.082
[0063] [0063] TABLE 3B Comparison of Kawabata Pure Bending Tester Results in Filling Direction A Untreated Nonwoven Fabric 160 g/m 2 B 0.173 2HB05 0.088 2HB10 0.102 2HB15 0.094 Treated Nonwoven Fabric 160 g/m 2 B 0.070 2HB05 0.094 2HB10 0.076 2HB15 0.070
[0064] [0064] TABLE 3C Comparison of LAB Readings for Color Variation Sample L* A* B* Untreated 74.70 7.39 33.68 Treated 75.86 8.56 36.21
[0065] Several observations can be made regarding the data in Tables 3A, 3B, and 3C. First, the treated dyed samples exhibit lower Bending Stiffness (B) and Bending Hysteresis (2HB05-15) than the untreated, dyed samples for both the warp and fill estimated directions. This indicates that the treated dyed fabric is, overall, more supple and recovers more quickly from bending than the untreated, dyed samples. These results demonstrate that exposing the fabric to the air impingement process before the fabric is dyed is an effectiveness procedure to improve the fabric's flexibility and drape, such that subsequent dyeing of the fabric did not negate these improvements. Furthermore, the results shown in Table 3C indicate that the treated dyed sample is lighter in color than the untreated dyed sample. This suggests that the air impingement process opens up the dense fiber-to-fiber construction of the fabric and creates available space, which allows the dye to further penetrate to fibers deep within the treated dyed fabric. As a result, it is likely that there is a decrease in the difference of dye concentration on the exterior fibers of the treated fabric and the dye concentration on the interior fibers of the treated fabric. Accordingly, it is likely that the fabric is more uniformly dyed. In contrast, the untreated dyed fabric likely has less available open space and therefore less penetration of dye into the interior of the fabric leaving a higher concentration of dye on the surface of the fabric, thereby creating a fabric that is slightly darker in color as noted by its exterior appearance. These noteworthy features of the treated dyed fabric suggest the usefulness of installing an air impingement finishing process in-line with the spun-bonded nonwoven production process because the benefits of air impingement are not lost after dyeing. Typically, this process arrangement would be both cost and time effective in manufacturing spun-bonded nonwoven fabrics comprised of multi-component splittable fibers with improved flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness.
EXAMPLE 5
[0066] Point-bonded Evolon® at 100 g/m 2 was tested for Bending Stiffness (B) using the Kawabata Pure Bending Tester. Two untreated samples (Sample A and B) and four samples treated with the air impingement process as described in Example 1 (Sample C, D, E, and F) were tested in both the warp and filling direction. Again, the warp direction is determined to be the machine direction, while the filling direction is estimated to be perpendicular to the warp, or machine direction. A ratio of fabric weight-to-Bending Stiffness (B) was also calculated, i.e. Ratio: Wt/(B). The results are shown in Table 4 below.
TABLE 4 Kawabata Bending Stiffness for Treated and Untreated Fabric Bending Stiffness (B) Ratio: Wt / (B) Warp Filling Warp Filling Untreated Sample A 0.490 1.154 204.1 86.7 Sample B 0.707 1.714 141.4 58.3 Average 0.599 1.434 166.9 69.7 Treated Sample C 0.147 0.103 680.3 970.9 Sample D 0.142 0.091 704.2 1098.9 Sample E 0.099 0.082 1010.1 1219.5 Sample F 0.110 0.098 909.1 1020.4 Average 0.125 0.094 800.0 1063.8
[0067] Similar to Tables 1 A and 1 B, the treated samples shown in Table 4 above exhibit lower Bending Stiffness (B) than the untreated samples for both the warp and fill estimated directions which indicates that the treated fabric is, overall, more supple and than the untreated samples. Additionally, the fabric weight-to-Bending Stiffness ratio of all of the treated samples is greater than the ratio for the untreated samples. The data shows that the fabric weight-to-Bending Stiffness ratio for the treated samples is about 187 or greater, as shown in Example 1, but, furthermore, the ratio shown herein for this example is about 680 or greater. These results demonstrate the effectiveness of treating the spun-bonded nonwoven fabric to improve the fabric's flexibility and drape, which are important attributes for end-use products such as apparel, napery, drapery, and upholstery.
EXAMPLE 6
[0068] Point-bonded Evolon® at 100 g/m 2 was tested for Moisture Vapor Transmission Rate according to ASTM E96. Two untreated samples (Sample A and B) and two samples treated with the air impingement process as described in Example 1 (Sample C and D) were placed over a mason jar and secured with the ring portion of the mason jar lid. The mason jar, containing 330 ml of water, was weighed prior to a 24-hour test period and was then re-weighed after the 24-hour test period. The difference in weight of the jar, in combination with the size of fabric that covered the opening of the jar, determined how much water was transmitted through the fabric over the 24-hour test period. The results are shown in Table 5 below.
TABLE 5 Comparison of Moisture Vapor Transmission Rate Moisture Vapor Transmission Rate (g/m 2 ) Untreated Sample A 616.74 Sample B 638.76 Average 627.75 Treated Sample C 726.87 Sample D 770.39 Average 748.63
[0069] Table 5 shows that treating the nonwoven fabric with the air impingement process results in a 19 percent increase in moisture vapor transmission rate of the fabric. It is contemplated that a moisture vapor transmission rate of about 675 g/m 2 or greater (an increase of approximately 8 percent or more) may result in some benefit for enhancing the fabric's moisture transmission properties. This enhancement of the fabric is useful in end-use products such as sports apparel, cleaning cloths, napery, and any other applications where moisture transmission is an important feature.
[0070] The above description and examples show the unexpected and beneficial flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness properties provided by the inventive spun-bonded nonwoven fabrics comprised of continuous multi-component splittable fibers. These benefits are achieved via a chemical-free process that mechanically modifies the surface of the fabric without actually contacting the surface of the fabric, in order to reduce or eliminate skin irritation and minimize damage to the surface of the fabric. Accordingly, this invention provides expanded utility within previously unavailable markets such that the fabric of the invention may be incorporated into articles of apparel, bedding, residential upholstery, commercial upholstery, automotive upholstery, napery, drapery, residential and commercial cleaning cloths, cleanroom items, allergy barriers, and any other article wherein it is desirable to manufacture an end-use product with these heretofore unavailable beneficial aesthetic and performance characteristics.
[0071] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the scope of the invention described in the appended claims.
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This invention relates to specific, improved spun-bonded nonwoven fabrics comprised of continuous multi-component longitudinally splittable fibers. The resulting nonwoven fabrics exhibit enhanced flexibility, drape, softness, thickness, moisture absorption capacity, moisture vapor transmission rate, and cleanliness in comparison with other nonwovens of the same fiber construction. These improved aesthetic and performance characteristics permit expansion of high-strength nonwoven fabric materials into other markets and industries currently dominated by woven and knit fabrics that exhibit such properties themselves, but at high cost and requiring greater manufacturing complexity. Such enhanced fabrics are subjected to certain air impingement procedures, for instance through directing low-pressure gaseous fluids at high velocity to the surface of the targeted nonwoven fabric. Also encompassed within this invention is the method of treating such a specific nonwoven fabric with this air impingement procedure.
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BACKGROUND OF THE INVENTION
The present invention is in the field of photochromic glasses and relates to refractive index-corrected photochromic glasses useful in the manufacture of photochromic ophthalmic lenses.
Photochromic glasses comprising crystallites of a silver halide as the phototropic phase have been described by Armistead and Stookey in U.S. Pat. No. 3,208,860. Eppler and Stookey disclose, in U.S. Pat. No. 3,197,296, a family of refractive-index-corrected silver halide photochromic glasses suitable for use in ophthalmic lenses.
Silver-free photochromic glasses exhibiting phototropic behavior analogous to that of the silver halide photochromic glasses, but comprising copper-cadmium halides in the phototropic phase, are reported by Araujo in U.S. Pat. No. 3,325,299. Additional copper-cadmium halide photochromic glasses are disclosed in U.S. Pat. No. 3,954,485 to Seward and Tick, a patent dealing with the manufacture of silver-free polarizing photochromic glasses.
The above-described silver-free photochromic glasses, hereinafter referred to as copper-cadmium halide photochromic glasses, offer certain economic and functional advantages over silver halide photochromic glasses. Included among these advantages are a smaller batch cost, due to the elimination of silver, a reduced dependence of photochromic properties on glass temperature, and a more desirable relationship between the intensity of the incident light and the photochromic darkening induced thereby in the glass.
Glasses which are to be utilized as ophthalmic lens glasses must be refractive index-corrected, i.e., they must exhibit a refractive index (n D ) in the range of about 1.52-1.54, preferably about 1.523, in order to be compatible with presently-available ophthalmic lens grinding and testing equipment. It is also essential that the glass be of optical quality, i.e., low in haze and free of inclusions and the like.
In the case of photochromic glasses for ophthalmic use, photochromic performance which is at least approximately equivalent to present commercially-available photochromic ophthalmic lenses is also required. Important elements of photochromic performance include rapid photochromic darkening upon exposure to actinic radiation, rapid fading in the absence thereof, and the attainment of an adequate degree of darkening in ophthalmic thicknesses (about 2 mm) when exposed to sunlight.
Refractive index-corrected copper-cadmium halide photochromic glasses of optical quality would find ready application in the manufacture of photochromic ophthalmic lenses, provided that acceptable photochromic properties were exhibited thereby. However, prior art refractive index-corrected base glasses used in the silver halide photochromic system, i.e., the base glasses described in the aforementioned U.S. Pat. No. 3,197,296 to Eppler et al., do not generally provide a good base for copper-cadmium halide photochromic phases. Substitution of copper-cadmium halide for silver halide in these glasses typically results in a product exhibiting relatively poor photochromic performance.
It is a principal object of the present invention to provide refractive index-corrected glass compositions suitable for making copper-cadmium halide photochromic glass lenses of optical quality, and ophthalmic lenses provided therefrom, which exhibit excellent photochromic properties.
It is a further object of provide glass compositions of this type which can be easily melted and formed utilizing existing glass-working techniques, yet which provide ophthalmic products which can be chemically strengthened by known methods and which meet or exceed existing standards for chemical durability and weatherability.
Other objects and advantages of the invention will become apparent from the following description thereof.
SUMMARY OF THE INVENTION
A major obstacle to the development of useful refractive index-corrected copper-cadmium halide photochromic glasses resides in the fact some of the oxides most effective in raising the refractive index of the glass, e.g., PbO and ZnO, are not desirable in the copper-cadmium system, due to an apparent adverse affect on photochromic properties. We have established that other oxides may be used for this purpose, but the increased quantities thereof which are needed to adjust the refractive index of the glass ultimately limit the amount of silica which can be used, adversely affecting the resistance of the glass to weathering and acid attack.
The photochromic performance of a refractive-index-corrected copper-cadmium halide photochromic glass depends also upon the presence of a specified minimum quantity of B 2 O 3 . Yet glasses containing the required amount of this constituent, being limited as to silica content, exhibit a marked phase separation tendency such that a hazy product, rather than a product of optical quality, is produced following heat treatment to develop photochromic properties. This tendency can be mitigated somewhat by the addition of a specified quantity of Al 2 O 3 , but is futher aggravated by the alkali metal oxide constituents which must be used to satisfactorily melt the glass.
Notwithstanding the above difficulties, we have discovered an area of silicate glass composition wherein refractive index-corrected copper-cadmium halide photochromic glasses of optical quality and exhibiting satisfactory photochromic performance may be provided. This composition area includes glass having analyzed compositions consisting essentially, in weight percent, of about 40-60% SiO 2 , 13-26% B 2 O 3 , 6-16% Al 2 O 3 , 3-15% total of alkali metal oxides selected from the group consisting of Li 2 O, Na 2 O and K 2 O, 8-20% total of refractive index-correcting oxides selected from the group consisting of MgO, CaO, BaO, SrO, TiO 2 , ZrO 2 , WO 3 , MoO 3 , Nb 2 O 3 , La 2 O 3 and Ta 2 O 5 , 0.1-0.5% CuO, 0.3-1.5% CdO, 0.3-0.9% Cl, 0-0.6% SnO, and 0-2% F.
Glass compositions within the above-described composition area can be melted and formed to provide glass products of optical quality which exhibit a refractive index in the range of about 1.52-1.54, preferably about 1.523, and which can be heat treated in accordance with conventional procedures to develop good photochromic properties therein without developing excessive haze. These glasses are routinely heat-treatable to provide photochromic properties which include, in 2 mm. thickness, a transmittance not exceeding about 55% in the fully darkened state and a fading rate providing fading of at least about 12 percentage points of transmittance in a five-minute fading interval from the fully darkened state.
Additional properties which are highly desirable in a photochromic glass to be used for ophthalmic lenses are excellent chemical durability and the capability of being chemically strengthened to high strength levels. The abovedescribed glasses are generally ion-exchange strengthenable by contact with molten Na + or K + salts, but good strengthenability by conventional Na + -for-Li + ion exchange processing is of substantial commercial importance. The inclusion of Li 2 O in the glass as an essential constituent permits strengthening by presently used sodium-for-lithium ion-exchange processes; however, such additions must be limited since Li 2 O tends to reduce the chemical durability of the glass.
The melting and forming characteristics of a glass are additional elements affecting its suitability for ophthalmic use. Present commercial melting and forming processes for ophthalmic ware require the use of a glass composition exhibiting a viscosity of at least about 3000 poises at the composition liquidus temperature. Yet some of the oxides otherwise suitable for raising the refractive index of the glass also increase the liquidus temperature thereof, a factor which increases the tendency toward glass devitrification during forming.
Within the above-described composition range for refractive index-corrected copper-cadmium halide photochromic glasses, we have discovered a narrow range of glass composition which provides not only the required refractive index, optical clarity and photochromic response necessary for ophthalmic use, but also good chemical durability, a liquidus-viscosity relationship satisfactory for conventional forming processes, and excellent ion-exchange strengthening characteristics. Compositions exhibiting these combined properties include those consisting essentially, in weight percent by analysis, of about 45-56% SiO 2 , 14.5-21% B 2 O 3 , 9.0-15% Al 2 O 3 , 1.4-2.4% Li 2 O, 2-12% Na 2 O, 0.-6.0% MgO, 0-3.5% BaO, 0.-2.5% TiO 2 , 0-1.4% ZrO 2 , 0-1.5% La 2 O 3 , at least 8% total of MgO+BaO+TiO 2 +ZrO 2 +La 2 O 3 , 0.1-0.5% CuO, 0.3-1.5% CdO, 0.3-0.9% Cl, 0-0.6% SnO and 0-2% F.
Compositions within the above-described range exhibit satisfactory forming behavior, having a viscosity at the liquidus of at least about 3000 poises. They also provide glass products which are low in haze and which exhibit a refractive index (n D ) in the 1.52-1.54 range (e.g., 1.523). These products typically possess excellent chemical durability, characterized by freedom from visible surface attack following a 10-minute exposure to 10% (wt.) HCl at 25° C., and are heat-treatable to provide photochromic properties including, in 2 mm. thickness, a transmittance not exceeding about 55% in the fully darkened state and fading of at least about 12 percentage points of transmittance in a 5-minute fading interval from the fully darkened state.
Finally the products are chemically strengthenable by known sodium-for-lithium ion exchange processes to provide unabraded modulus of rupture strengths of at least about 35,000 psi, with an ion-exchange layer depth of at least about 3 mils as determined by conventional stress layer examination techniques utilizing, for example, a polarizing microscope with a Babinet compensator. These strength and compression layer characteristics, which are readily obtainable by sodium-for-lithium salt bath ion-exchange processes at normal ion-exchange temperatures (300°-450° C.), permit ophthalmic lenses of 2 mm. thickness to routinely pass standard ball drop impact tests.
DETAILED DESCRIPTION
Glasses within the above-described composition ranges may be melted in conventional glass melting units such as pots, tanks, crucibles or the like utilizing ordinary glass batch constituents, including oxides or other compounds which are thermally decomposable to yield a melt of the selected composition at the temperatures customarily employed for melting borosilicate glasses. The melts may be formed into glass articles by drawing, rolling, blowing, pressing or other conventional techniques.
Of course, minor quantities of other conventional glass ingredients may be included in the compositions hereinabove described, provided that the essential properties of the compositions are not unduly affected thereby. For example, common glass colorants such as Cr 2 O 3 and the like may be utilized to modify the color of the glass and/or to generally reduce the optical transmittance thereof, if desired. Similarly, FeO and SnO may be useful in minor quantities as low-temperature reducing agents, and FeO is particularly useful as an additive to modify the infrared absorption characteristics of the glass in the known manner. Fining agents and other low-temperature reducing agents may also be employed to improve the melting, heat treating, and photo-chromic characteristics of the glass.
Particular examples of glass compositions within the scope of the invention are set forth in Table I below. Compositions are reported in parts by weight on the oxide basis, except for the halogens which are reported on an elemental basis in accordance with prior reporting practice.
TABLE I______________________________________1 2 3 4 5 6 7 8______________________________________SiO.sub.2 50.5 51.3 49.3 51.0 49.1 54.9 50.0 55.0Al.sub.2 O.sub.3 10.2 10.2 10.1 10.4 13.3 9.3 10.5 8.5B.sub.2 O.sub.3 19.6 20.6 19.6 20.2 20.3 17.9 20.6 16.5Na.sub.2 O 3.1 3.6 4.1 2.9 3.1 3.1 3.7 3.5Li.sub.2 O 1.8 1.4 1.8 1.9 2.5 1.8 2.6 1.5K.sub.2 O -- -- -- -- 0.5 0.5 -- --MgO 5.1 5.1 6.1 6.4 3.5 4.1 6.1 4.0BaO 2.9 2.9 2.9 2.9 2.2 2.2 2.2 3.5TiO.sub.2 1.4 1.65 1.4 1.3 1.8 2.0 2.1 2.0ZrO.sub.2 0.8 1.1 0.8 0.9 -- 0.8 0.6 1.1La.sub.2 O.sub.3 1.0 1.0 1.0 1.2 0.9 1.0 -- 1.0CuO 0.19 0.25 0.29 0.28 0.35 0.30 0.34 0.30CdO 0.55 1.0 1.0 0.9 1.0 1.1 1.0 1.0Cl 0.6 0.7 0.7 0.7 0.7 0.7 0.55 0.7F 1.06 1.2 1.06 1.0 1.28 1.1 2.0 1.1SnO 0.12 0.10 0.25 0.09 0.07 0.06 0.28 0.10Cr.sub. 2 O.sub.3 -- -- 0.041 -- -- -- -- 0.015______________________________________
To prepare glass articles of the above compositions, glass batches may be compounded utilizing conventional glass batch constituents and the batches then melted in crucibles or optical glass melting units by heating to temperatures of about 1300° C. for a melting interval of about 3 hours. The resulting melts may then be cast into glass patties and placed in an annealer.
As is well known, certain of the photochromic constituents of photochromic glasses, particularly chlorine and cadmium, are subject to loss through volatilization during melting, so that compensation adjustments to batch composition must be made in order to reach a particular target composition. Such losses can range from about 10-70% for CdO and 30-60% for chlorine in the present compositions, depending on the particular melting conditions and type of melting unit employed. The compensating upward adjustments in batch concentration necessary to provide glass patties or other articles containing the levels of retained CdO and Cl shown in the above examples are readily determined for any particular melting procedure by routine experiment.
Conversion of glass patties of the above-described compositions to photochromic glass articles may be accomplished by exposing each patty to a heat treatment at temperatures between the glass strain and softening points. Thereafter, the glass patties are cut, ground, and polished to provide glass samples about 2 mm. in thickness from which the photochromic properties of the glass may readily be determined.
Typical heat treatments and resulting photochromic properties for each of the glasses reported above in Table I are reported below in Table II. Most of the heat treatments reported are two-stage heat treatments, for which two holding temperatures and holding times are reported. All of the photochromic glasses shown in the Table have refractive index values in the range of approximately 1.52-1.54.
The photochromic properties reported in Table II include the undarkened transmittance T o , the darkened transmittance T D20 , and the faded transmittance T F5 for each glass, as determined on samples of 2 mm. thickness. The darkened transmittance measurements are made on glass which has been darkened by a 20-minute exposure to two 15-watt black-light blue fluorescent lamps, this exposure being deemed sufficient to produce essentially complete darkening of the glass. The faded transmittance measurements are made on the same glass after a five-minute fading interval from the fully darkened state. Of course, photochromic properties such as reported in Table II vary depending upon heat treatment, so that different photochromic properties may be obtained by varying the time or temperature shown.
TABLE II__________________________________________________________________________Glass No. 1 2 3 4 5 6 7 8__________________________________________________________________________Heat Treatment 530°-30 530°-30 530°-30 530°-30 620°-30 530°-30 540°-30 620°-20(° C. - min.) 600°-30 620°-30 640°-15 600°-30 620°-30 600°-30T.sub.o 88.9 88.0 77.9 91.6 87.1 88.9 89.7 83.6T.sub.D20 41.4 53.0 24.6 38.0 31.5 52.2 45.4 45.0T.sub.F5 60.9 68.0 36.1 56.1 45.8 68.1 64.5 60.9__________________________________________________________________________
Where excellent chemical durability, good forming characteristics and a high degree of chemical strengthenability are required in a refractive index-corrected composition for ophthalmic use, it is found that the narrow composition limitations hereinabove defined for such glasses should be carefully observed. The chemical durability of the product is adversely affected if more than the specified quantities of B 2 O 3 , MgO, Li 2 O or BaO are used, or if insufficient SiO 2 or Na 2 O are present. The liquidus temperature of the glass is undesirably increased by excess amounts of SiO 2 , MgO or ZrO 2 , whereas chemical strengthenability by conventional Na + -for-Li + processing falls below the required levels if insufficient Li 2 O is present. Excess quantities of Na 2 O or F provide a glass which tends to become hazy during the photochromic development heat treatment, while reductions in B 2 O 3 or the photochromic constituents CuO, CdO and Cl below the required levels provide a glass with poor photochromic properties.
It is found that photochromic performance is improved if the glass is maintained in a slightly reduced state during melting. This is best accomplished through the use of a glass reducing agent such as SnO; however, other glass reducing agents may be substituted for SnO, or increased glass melting temperatures can be employed alone or in combination with selected reducing agents, to achieve equivalent results.
Table III below sets forth some examples of glasses outside the preferred range of compositions above recited, which compositions exhibit low acid durability, marginal ion-exchange strengthenability, low refractive index, or excess haze, attributed in each case to variations in base glass composition outside the specified ranges. Compositions are reported in parts by weight on the oxide basis as calculated from the batch, except for the halogens which are reported on an elemental basis.
TABLE III______________________________________ A B C D______________________________________SiO.sub.2 50.6 50.5 47.1 51.4Al.sub.2 O.sub.3 10.2 10.2 10.3 10.4B.sub.2 O.sub.3 19.2 20.0 19.7 20.6Na.sub.2 O 3.0 3.7 8.0 3.6Li.sub.2 O 2.3 1.36 1.0 1.4MgO 6.3 5.0 4.3 3.0BaO 3.4 2.4 -- 3.0TiO.sub.2 1.8 1.7 2.1 1.8ZrO.sub.2 0.6 1.5 0.9 1.1La.sub.2 O.sub.3 -- 1.0 -- 1.0CuO 0.34 0.3 0.36 0.25CdO 2.0 2.1 2.1 2.0Cl 1.7 1.7 2.6 1.7F 0.9 1.25 1.2 1.2SnO 0.16 0.25 0.3 --PbO -- -- -- 2.0Glass Low acid Low ion- Low ExcessProperties dura- exchange Refrac- Haze bility strength- tive Index enability and Strengthen- ability______________________________________
As previously noted, it may be desirable to include minor amounts of glass colorants in refractive index-corrected photochromic glasses to modify glass color and/or to reduce the undarkened transmittance thereof. One of the most effective additives for this purpose is Cr 2 O 3 , and for applications requiring tinted lenses such as, for example, prescription sunglasses, glass compositions including Cr 2 O 3 in an amount ranging up to about 0.3% by weight are particularly preferred. Similarly, for purpose of providing heat absorbing glasses, compositions containing FeO in an amount ranging up to about 0.20% by weight are employed.
Of course, it is evident from the foregoing description that numerous modifications and variations in the compositions and procedures hereinabove set forth may be carried out within the scope of the invention as defined by the appended claims.
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Alkali boroaluminosilicate glass compositions providing refractive index-corrected copper-cadmium halide photochromic glasses of optical quality, particularly useful for making ophthalmic lenses, are described. Ion-exchange-strengthenable glasses exhibiting good chemical durability and a satisfactory liquidus-viscosity relationship in combination with good photochromic properties and the required refractive index are also provided.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of cognitive functioning and results thereof, particularly problem solving, inventing, innovating and realizing human potential.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to methods and apparatuses for facilitating cognitive functioning and the results of such functioning as evidenced by physical form. Such facilitation includes interpreting, analyzing and applying the insights and discoveries that emerge from the guided exploration and analysis of the physical symbolic forms. These physical forms can be created individually or collaboratively and can also be represented and enhanced by virtual reality or electronically with the aid of computer technology to stimulate the human sensorium. Such physical forms are tangible, visual, symbolic and metaphorical information for problem solving, inventing and other functions requiring creative and critical mental functioning.
[0003] In the mid-1900's in the United States, business, educational and political leaders recognized the need for gathering intellectuals from various fields in order to creatively generate new ideas for rational consensus so as to accelerate and enhance the decision making process. These sometimes well-funded collaborative efforts came to be known by the coined words “think tank” or “task force.” Recognizing that “a picture is worth a thousand words” at times, graphic presentations, slide shows and pictures were often used. These tools accelerated decision making as well as provided motivation and emotional stimulation to discussions. The advertising industry has repeatedly demonstrated that pictures evoke emotional responses. These emotional responses can motivate people to buy products, or adopt a particular opinion. Pictures can immediately provide a context for thoughts and thereby clarify the thoughts being presented.
[0004] The preferred models of the present invention incorporate not only the visual impact of 2-D pictures but are five-dimensional (“5-D”). 5-D models embody commonly accepted 3-dimensional physical space, as well as 4-D perspective. 4-D perspective involves time and motion. The “fifth dimension” relates to all forms of symbolism, or symbolic languages (e.g., words, images, objects, signs, stories, symbols, archetypes, for example). The 5-D models can be kinetic, multi-layered and often highly animated objects.
[0005] The methods and apparatuses of the present invention facilitate business, educational, community and family functions by giving visual, tangible and concrete form to people's creative and critical ideas. The present invention provides tools for visualization to foster the exploration of ideas and the communication of these ideas to others through natural, hands-on methods. The methods of the present invention illuminate thought processes through unique modeling methods.
[0006] The present invention may be used to stimulate creativity, to discover and make inventions, to connect things that seem unrelated, to solve problems and find solutions, to examine and question original ideas, and to enrich the experience of learning and enhance communication.
[0007] Although the inventor is not aware of any other similar inventions, there are other representative patents in the field. For example, U.S. Pat. No. 4,717,343 relates to a method of conditioning a person's unconscious mind to affect a change in the person's behavior by using a program of video pictures to condition the person's thought pattern to alter behavior.
[0008] U.S. Pat. No. 4,734,038 relates to a system and method of psycho-actualized learning comprising (1) selecting a behavior to be modified, (2) defining the steps to be taken to effectuate the modification, (3) assigning a mnemonic for each step and (4) providing a visual image of a role model for behavioral emulation.
[0009] U.S. Pat. No. 5,151,080 relates to a method and apparatus for inducing and establishing a changed state of consciousness by using electro-acoustic means for creating and generating electromagnetic sound signals, producing synthetic human speech signals, superimposing the sound and speech signals to make a superimposed signal, and conveying the signal to the ears.
[0010] U.S. Pat. No. 5,312,114 relates to a method and apparatus for enhancing decision making comprising (1) thinking about a subject until an issue related to the subject comes to mind and making a choice from alternatives of the issue, (2) looking inside the head to ask if you are right, (3) picturing the subject in the head and while daydreaming the picture, listening for thoughts on both sides of the issue and change over time and (4) verbalizing conclusions.
[0011] U.S. Pat. No. 5,387,104 relates to an instructional system for improving communication skills using computer technology to integrate multi-sensory stimuli for synthesis of individualized instruction, evaluation, and prescription for advancing such skills.
[0012] These patents disclose methods and systems which, when used in combination, lead users to improve their visualization skills, creativity, communication and decision making abilities. In contrast, the present invention focuses on using a detailed model, preferably a symbolic 5-D model, to improve functions, including solving problems and conceptualizing ideas in a visual and tangible way. Also, 5-D models make the subconscious mind conscious and comprehensible. Furthermore, they reveal a person's understanding of a subject, viewpoint or field of knowledge. Through use of this model in the instant process, the user can quickly grasp and convey a concept or experience, regardless of how complex the concept is or how personal and subtle the experience.
[0013] The process of the present invention differs from these prior disclosures in that, in addition to providing prepared materials for the user to work with, it carefully instructs the users in creating their own materials and in constructing a symbolic multi-dimensional physical model. Moreover, it guides users in discovering and adapting materials from their immediate environment, demonstrating how to make comparisons between different subjects, including: analogy, figure of speech, metaphor, symbol, story, allegory, pun, story-writing, story-telling, scenario-making, visualizing, hypothesizing, brainstorming, role-playing, and many more. The instant process not only makes metaphors to connect one thing to other things, it also uses all the ways of analyzing, evaluating, modeling, and tangibly realizing the meanings of the connections made.
SUMMARY OF THE INVENTION
[0014] One of the methods of the present invention is called “metaphorming.” As used herein “metaphorming” refers to the act of making connections, discoveries, inventions and applications. It involves combining, integrating, bridging, and relating many different sources of information and material forms. To metaphorm is to connect, shape, and transform some thing in our mind's eyes and hands. The term is derived from the ancient Greek words meta which means “between,” “after,” “beyond,” “transcending,” and phora which means “transference.” Metaphorming is a four step process described in more detail below.
[0015] It is an object of the present invention to provide a method for improving communication. The act of getting people to truly communicate is fundamental to their sense of success, happiness, mental health, and well-being. The experiential nature of the methods and apparatuses of the present invention connects people with themselves and with others in profound way, thus enriching communication.
[0016] It is a further object of the present invention to provide a method for leveraging tacit and explicit knowledge. People know more than they think they know. The methods and apparatuses of the present invention help extract this knowledge in a natural, intuitive, easy and pleasurable way, leaving people the option of working individually or collaboratively to this end.
[0017] It is a further object of the present invention to provide a method for tapping human potential. The methods and apparatuses of the present invention enable people to see the limits or boundaries of their knowledge, and suggest ways of transcending them. This is particularly useful when organizations (such as companies and schools) need to rapidly and thoroughly assess an individual's knowledge, core competencies, skills, and resources.
[0018] It is a still further object of the present invention to provide a method for fostering creativity, breakthroughs and innovations. The methods and apparatuses of the present invention catalyze and initiate connection-making and idea-generation. They produce fresh insights, cultivate discoveries, inventions and innovations with multiple applications.
[0019] The present invention can be applied to a number of functions in the following representative areas and to the overall integration of these areas of peoples' lives:
[0020] In the corporate setting, it can be used, for example, to (1) enrich and accelerate research, development and design processes; (2) create multi-purpose visual knowledge maps; (3) give form to global strategic plans and corporate mission statements; (4) enhance re-engineering processes and effectively implement tactical and practical action plans; (5) improve communication, team building skills, collaborative work, innovation and productivity; (6) make connections between different work processes, ensuring best practices; (7) to conceptualize a problem or scientific paradigm in order to test a hypothesis or challenge an assumption, or examine and rethink the implications of a theory; and (8) for crisis management and conflict resolution. The process of the present invention is effective in enhancing functions in the corporate realm, for example, as an “emergency procedure,” or crisis management, in opening up the imagination of people whose creativity is severely blocked by anxiety, fear, close-mindedness or compartmentalization.
[0021] In the educational setting, it can be used, for example, to (1) make improvements in learning and applying curricular (content) materials; (2) better understand and use curricular materials applied to everyday life; (3) design educational games that enhance the learning process; and (4) facilitate advanced planning and development of scholastic activities.
[0022] The present invention also is useful in the family and home, for example, to (1) foster communication between family members; (2) develop abilities of families to act as lifelong collaborative learners; (3) improve family functionality, cohesion and wellbeing; (4) nurture family values, awareness and interest in learning, and (5) discover points of human commonalities.
[0023] Concretely, the work done through the process of the invention can include areas as disparate as the design of an innovative museum and garden; the re-engineering of aspects of a telephone company's installation and service system; the development of new technology and services for leading Application Service Providers (ASPs) in the Internet industry; the invention and development of an alternative plasma fusion energy system; the enhancement of learning systems for schools; and the improvement of systems and techniques for dealing with children-at-risk and broken families, among other familial and social dysfunctions.
[0024] The process of the present invention also may be used to enhance other functions, including to design games, children's pop-up books, CD-ROM's, Internet electronic games and services, audiocassettes, videotapes and practical workshop exercises in which the process serves as the basis of their operations. A version of the process comprising the 5-D model in a wheel form may be used in educational and corporate settings, for example, to solve a particular problem of a company. The process of the present invention can be adapted to a variety of media, both traditional and electronic.
[0025] The process can be used by an individual or by large groups of many hundreds of people, or more simultaneously. The users can be from all levels of education, social, economic and ethnic backgrounds and ages.
DESCRIPTION OF THE FIGURES
[0026] [0026]FIG. 1 sets forth the four steps of the process of the present invention.
[0027] [0027]FIGS. 2 through 7 show various forms of 5-D models useful in the present invention applications.
[0028] [0028]FIGS. 8 through 13 show the evolution of a 5-D model described in the Example
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The preferred physical, symbolic models (i.e., apparatuses) are five-dimensional (“5-D”). 5-D models embody commonly accepted 3-dimensional physical space, as well as 4-D perspective. 4-D perspective involves time and motion. The “fifth dimension” relates to all forms of symbolism, or symbolic languages (e.g., words, images, objects, signs, symbols, numbers, figures of speech, euphemisms, puns, riddles, stories, visual metaphors, physical analogies, allegories, archetypes, etc.).
[0030] Referring to FIGS. 2 through 6, 1-Dimension refers to all forms and usages of words (Element 1). Dimensions refer to all forms and usages of images and pictures (Element 2). 3-Dimensions refer to objects and structures (Element 3). 4-Dimensions refer to all forms and usages of moving, dynamic parts or structures (Element 4). And, 5-Dimensions refer to the whole spectrum of symbolic creations: from abstract to concrete things; from figurative to literal things; from non-objective, or imaginary, to representational or realistic things (Element 5). In short, 5-D symbolic models can be described as the arts. “The arts embody the languages of our senses of touch, taste, smell, hearing, seeing and knowing. Without these languages we couldn't begin to describe or relate our experiences of life in any meaningful way.” (Voice, March 2001, p. 13; published by the Washington Alliance for Arts Education, Seattle, Wash.)
[0031] When all five dimensions of communication are used to generate, articulate and convey viewpoints, ideas, insights, and inventions or innovations, the sense of understanding increases, as does the meaning and usefulness of the information being communicated. As well, the information is retained longer and applied in more personally meaningful and productive ways. Furthermore, when the methods and apparatuses of the present invention are experienced, connections between different sources and forms of information become apparent. Knowledge and ideas that previously remained separate and unrelated to one another become connected. In effect, the tools of the present invention enable the user to see the deeper connections and relationships between all forms of information. This act of seeing and creation improves human communication, strengthens and inspires collaborative learning, helps people leverage their tacit and explicit knowledge, and accelerates breakthroughs and innovations.
[0032] The 5-D models can be kinetic, multi-layered, highly animated and dynamic objects, which makes them literally and figuratively moving, so to speak, in more ways than one; meaning, their demonstrative and communicative powers can be especially visceral and emotionally moving. This is shown in FIGS. 5 and 6.
[0033] The methods and apparatuses of the present invention facilitate business, educational, and family functions by giving visual, tangible and concrete form to creative and critical thinking and ideas—thus making it easier and more effective to communicate thoughts, feelings, viewpoints, beliefs, realizations, intuitions and ideas.
[0034] The physical symbolic models of the present invention can be created spontaneously and intuitively, or logically and methodically. They can be “unpacked” (analyzed and interpreted) and discussed in an orderly, rational, and systematic way or randomly.
[0035] Furthermore, unlike the conventional use of multi-media, in which words, images, objects, and other forms of language are used to enrich the experience of information or ideas presented, the symbolic nature of these 5-D models allows the users to continually transform the model's content, physical attributes, meanings, implications, associations, usages and purposes.
[0036] The 5-D models and model-building activity deepen people's understanding and knowledge of subject matter, topics, issues, ideas, feelings, viewpoints, beliefs, values, and their implications. Every mark or symbol or movement in these physical models is symbolic and can be understood as representing visible, tangible thoughts and concepts. See FIGS. 2 through 6. Each symbolic element reveals a world of hidden information and sensibilities in the form of Elements 1 through 5, discussed above. This versatile symbolic language can be effectively used to tell stories, relate data, information and knowledge in such a way that it transcends our compartmentalized, disciplines and knowledge. The 5-D symbolic models of the present invention provide innumerable clues for solving problems, reframing and answering questions, or developing an opportunity.
[0037] As users interpret the meaning of the models, a web of connections is created in the human brain that involve visual, auditory, tactile and other sensory modalities which serve to reinforce this content and store it long-term memory. Contemporary brain research on memory and learning suggest that this phenomenon of encoding information and sensory stimuli according to its emotional significance and existing knowledge structures underlies the operations of memory. (Newsweek, Jun. 15, 1998, p. 48-53; “How Memory Works”). This neurophysiological phenomenon is referred to as elaborative encoding. The processes of the present invention can be the biological basis or manifestations of elaborative encoding.
[0038] The 5-D models can be connected with one another through multiple interpretations. When users and others add their impressions, insights grow and mutual understanding increases. This shared understanding is essential for ensuring that individuals are aligned in the implementation and execution of their common goals and specific tasks.
[0039] The present invention provides tools for conceptualization, visualization and expressive manipulation. These tools may be used to foster the generation, exploration, implementation, advertising, marketing, and selling of ideas and knowledge, and the communication of these ideas to others through hands-on, interactive methods that can involve or be augmented by media technology. The methods of the present invention illuminate thought processes and all forms of “physical thinking” through unique modeling methods—thus providing a means of expressing this knowledge in myriad ways. The methods of the present invention draw upon the user's innate ability to build and construct things, without requiring any learned skill or artistic ability to engage this activity.
[0040] Metaphorming taps people's tacit and explicit knowledge, while revealing their many faceted intelligence (visual, spatial, mathematical/logical, musical, kinesthetic, emotional, intrapersonal, and interpersonal)—allowing for a greater freedom of conceptualizing, representing, and expressing ideas, viewpoints, beliefs, vision, values, issues, problems or opportunities The metaphorming methods and apparatuses enable people to apply their innate ability to think differently and innovatively—inspiring a sense of creative freedom, freeing the mind, encouraging openness, and exercising people's curiosity, skepticism and wonderment.
[0041] The present invention has been proven to stimulate creativity, breakthroughs and innovations in corporations, businesses, schools, communities, families and individuals. It has been used to make tangible discoveries and inventions by physically and conceptually connecting various types and forms of information, knowledge, ideas and things in highly original ways.
[0042] The process of the present invention, metaphorming, is set forth below:
[0043] The invention comprises a system comprising an iterative process comprised of four tangible steps (1) connection, (2) discovery, (3) invention, and (4) application.
[0044] Before these steps can take place, however, the user must select a function to be enhanced or propose a focal question to explore a specific subject, topic, issue, problem or opportunity. Once the question or function to be enhanced has been selected, a model is constructed. Users create images and forms or structures from an array of materials and techniques (i.e., marking pens, paints, magazines, photographs, collage elements, drawings, tape, etc.) delivered and used either physically or by electronic means via media technology.
[0045] Allow the model to develop and evolve at the users preferred, natural pace, or set a time limit, and recommend that the 5-D model be constructed within this time frame. Instructor or facilitator can emphasize the importance of modifying and changing the model.
[0046] The models may be in the form of drawings, three dimensional constructions or other forms of expression, including four dimensional animation, which involves time and motion in kinetic models. The depictions may use all systems of comparison and connection-making (including, for example, metaphor, analogy, figure of speech, story, symbol, hypothesis, and pun) in order to make connections between seemingly unrelated things, ideas, events and experiences.
[0047] Simple models created during the process normally take between 30 minutes and 3 hours to complete. More complex models, or models which depict complex connections, may take substantially more time.
[0048] Users of the process of the present invention create visual models by depicting metaphorms (which are a combination of metaphors, analogies, symbols, and stories) and connections between the function they wish to enhance and other things, either natural or human-made.
[0049] Once the model is constructed, the metaphorming process can begin. The steps are as follows:
[0050] 1. Connecting
[0051] Initially, users should address the physical characteristics and qualities of their models before addressing the conceptual elements and intentions. Questions can assist users in this process. The questions help orient and prepare the user's mind for the deeper journey into their creative processes and creations. Such questions may include, but are not limited to, the following: (1) What do you see? (2) What does your model look like? (3) Why did you give it this shape or form? (4) What are other visual elements that made up the model? (5) Are there a lot of colors used in the models, and what do they mean with respect to their forms and shapes? (6) Describe some of the model textures: Are they flat or very dimensional with much texture? (7) Are the shapes, forms and media used in the models similar? (8) Are the icons and symbols used representational, figurative or abstract? The questions to be asked will vary accordingly to meet the necessary requirements of the particular situation.
[0052] After noting the physical characteristics and qualities, users should address the conceptual elements and intentions. They should describe the music or sounds the symbols and icons evoke, asking, for example, these kinds of questions: (1) What does a particular symbol mean? (2) What symbols do you see in real life that represents other things? Are they concrete or abstract? (3) What would these works sound like, if they had a sound (e.g., classical, rock, jazz, rap, new age, and tribal)? (4) How would these works be different if they were the size of a room and participants could walk into or through them? (5) How would these works be different if they were four-dimensional, i.e., had a time element to them, like moving kinetic sculptures? (6) How would your model be different if it were the size of a room or building? (7) How would your experience of the model be different? During the connection step, users should list as many insights as possible.
[0053] 2. Discovering
[0054] Users further explore the connections and insights made in Step One. This discovery or “exploring” step may involve a number of activities including research, remodeling and additional unpacking.
[0055] Users should research elements of the connections and insights made in Step One. This research can involve use of a variety of tools, including, for example, the library, Internet, observations, interviews and direct contact with experts in a particular field, personal knowledge and interests, and other artistic and scientific resources. Users should get to know as much about their previous connections as feasible. Research should be guided towards identifying relationships between forms and processes, and between like and unlike processes, and exploring interconnections between the whole of systems and their parts. Exploration also involves comparing categories of relationships in and among things that seem unconnected or unrelated. For example, with regard to management information systems, users could explore power plants, overnight package companies, or learn more about how trees, nerve cells and other natural systems grow. They also should define the products of their growth. This research would help the users, in turn, to learn more about management information system designs.
[0056] Search for relationships between and within the models. Go beyond the surface of the things you see, hear, taste, smell and touch, to discover and understand the layers of details and levels of information. Relate why you selected the particular images and objects. Listen carefully and take notes on what the participants say. This will help users construct and respond to their next set of questions. Examples of such questions may include: (1) How many of you have had a similar experience to this? (2) How is this image similar to other images within the model? (3) How is one image related to the whole of the model? (4) How is each part embedded, or “nested” in the whole? (5) Does your model have a center? If so, where is it? (6) How would the meaning of the model change if another category is moved to the center? How would this modification change the message?
[0057] After thorough research, the users should amend and modify their previous models based on the findings of their research. Research will often lead to additional insights and possibly “discoveries.” These insights and discoveries should be incorporated into the previously generated models or used as a guideline to amend these models. This may also include constructing models jointly among the users. Another possibility is for users to model particular aspects of the earlier models, using the research to explore areas of interest in detail.
[0058] As used herein, “unpacking,” or analyzing and interpreting, comprises the following: The first stage of unpacking involves stepping back and observing the types of icons and symbols that were employed in the model as well as the similarities between icons. A list of the users' responses is generated. The list acts as a log of responses, so that users can revisit and analyze, for example, a particular statement or figure of speech used to describe a symbol or convey an idea.
[0059] Upon completion, users analyze and interpret the models. This process is referred to as “unpacking.” Unpacking enables the users to become familiar with the full realm of symbols used to create their models. It also helps users understand the symbols in a deeper, more meaningful and productive way. This, in turn, enables users to explore and interpret both their conscious and unconscious thoughts. It creates a window into the mind of the individual engaged in the process. It sheds light on the systems, processes and problems that may have been previously obscured by any number of mental barriers or blocked by the subconscious mind. Insights into the models and functions are formed during this unpacking activity.
[0060] In the second stage of unpacking, users take turns interpreting their model creations for the other users, if present. Users should explain why they selected the symbols, colors, shapes, etc. that they did. They should also note what other creations are similar to their creations and why. Each aspect of the user's model should be explored in as great depth as possible, with all users listening closely to the expressions of language and personal stories used in the descriptions. All users are encouraged to verbally interpret and discuss the models being presented. By doing this, users gain valuable insights concerning their models (and ultimately their thought processes) that otherwise would have remained hidden.
[0061] 3. Inventing
[0062] In this step, users will develop a plan and method for realizing an idea or inventing something that improves the function they wish to enhance. The inventions will be based on their exploration and discovery of the original connections. The inventions will be represented in the form of symbolic models. Again, models provide the method of visualization and conceptualization necessary to explore the inventions in a tangible manner.
[0063] Using the example of management information systems, users may invent a method for improving the system through discoveries made in researching how apple trees are like computer systems, or how apple orchards are similar in process to computer networks. The management information system may be redesigned to function more like an apple tree, or orchard, based on an understanding of the ecology of this natural system and how to sustain and maintain a healthy, ecologically sound system. The users would then express this invention in a model. The model would serve to put into visual form many of the aspects of the invention. The model would be “unpacked,” with further discoveries perhaps being made, and the invention model amended accordingly. This step encompasses recognizing and understanding the process of the symbolic model as an invention or innovation and posing other possibilities based on the connections and discoveries made. Examples of questions to ask may include: (1) What are some ideas that were generated based on previous discussion and discoveries? (2) Where is the invention or innovation in the symbolic model? (3) Describe the steps taken to make the invention, such as, gathering, assembling, modifying and combining materials and information.
[0064] 4. Applying
[0065] In this step, users will develop a plan and method for applying their inventions to improving the function they wish to enhance. They will also create a list of action items necessary for the implementation of their inventions. The tactical plan and list are preferably incorporated directly into the invention model.
[0066] A single invention can stimulate and support successive generations of discoveries and inventions. The improvement to the functions generated in Step Three can also be applied to other areas. For example, inventions that benefit the management information systems function of a company may also be used to improve other areas of the company, including, for example, product design, sales, marketing or product distribution. Models also can be developed that are specific to these areas. The process of the present invention serves to extend ideas, relationships, meanings, implications and information contained in the 5-D symbolic models into real-life areas, situations, circumstances and events.
[0067] The application step also involves a second generation (and subsequent generations) of invention based on the first invention, which is rooted in the initial comparison. The instant process is, therefore, iterative in nature—like the creative process itself Exemplary questions may include: (1) How can the model be applied to understand different things experienced during the course of a day? (2) How can the model be applied to understand things taught in school? (3) How does the geometry of the model reflect the geometry of the environment?
[0068] For example, a company engaged in re-engineering its management information systems (MIS), could try connecting the MIS functions to a number of functions outside this area of specialized information. Although this information may be unlike in form, appearance or representation, it is potentially similar in process, i.e., the way it works. Since a well-functioning management information system will deliver information on demand, users could explore other delivery systems, such as electric power plants and grids (which deliver electricity), overnight package companies (which deliver parcels), or apple trees (which deliver fruit), or brain cells (which deliver neurotransmitters). The visual models would, in this instance, depict the connections between the process of management information systems and the processes of these other systems.
EXAMPLE 1
[0069] Education
[0070] The instant process may be used in every day life to explore a certain concern, issue, problem, obstacle or opportunity. In this example, the process uses as the model, a wheel and spinner concept that is familiar to most people and is used to enhance educational functions. It can also use a variety of other shapes and forms, as seen in FIG. 7.
[0071] Referring to FIG. 7, in this example both the wheel 10 (or other forms 12 , 14 , 16 ) and the selection of its content are created by the participants using their own knowledge base and life experiences. Since the process uses the participants' life experiences, it is particularly meaningful to them and can be used for a variety of purposes. Its uses include connecting diverse sources and forms of information, combining ideas, and relating experiences and other activities. It can be used on a one-time basis to introduce and teach benchmark curricular content or it can be repeatedly used in a classroom environment over the course of a semester or longer. During the life cycle of the process, using the wheel, the participants can continually modify its design and content, making a highly personalized yet universal teaching tool.
[0072] Procedure
[0073] 1. Referring now to FIG. 8, make a large wheel 10 (or functionally similar form), complete with spinner 5 . The wheel should be at least three to four feet in diameter to allow room to add objects, images, and words.
[0074] 2. Referring further to FIG. 8, divide the wheel 10 (or other appropriate shape) into approximately six to twelve segments 20 , 22 , 24 , 26 , 28 , 30 , 32 , 34 , 36 , 38 , 40 . After making the segments, leave the wheel blank, with no words or images on it. Attach the wheel to a wall, or lay it on the floor or table, where everyone can see it.
[0075] 3. Choose a broad subject, for example, education, environment, family, leisure, work, health, or sports. The subject must be of interest, or meaningful and familiar to the participants. For example, corporate life would not be a good subject for third grade children but would be for adults. However, a subject such as leisure activities would likely be interesting to any participant.
[0076] 4. Referring now to FIG. 9, subdivide the subject into “categories” and place them as headings 50 , 52 , 54 , 56 , 58 , 60 on each of the segments of the wheel. For education, the categories may be the different disciplines taught in secondary school, such as art, physics, chemistry, math, history, literature, etc. If the subject is leisure activities, participants could choose categories such as camping, music, sports, travel, etc. Again, make sure that the categories are meaningful to the participants.
[0077] 5. Referring now to FIG. 10, list characteristics 70 , 72 , 80 , 82 of each category. Participants should come up with words, phrases, images and icons that describe that category. For example, in the category of biology, participants could use words and images such as fish, mammals, microscopes and petri dishes. Participants should actually create these through writing, collage, drawing and other forms of symbol making, model building and construction. It is up to the participants to decide how many images, icons and other visual artifacts should be employed and which ones will best represent the categories. When finished, participants should attach their creations to the appropriate category on the wheel. For example, the category of biology would now have on it the symbols of fish, mammals, microscopes and petri dishes selected above. Larger images and three-dimensional forms and symbols may have to be attached outside the wheel with strings linking them to the appropriate category. Alternatively, if the creations are elaborate enough, they could be set around an entire room expanding the scope of the wheel. The wheel can become part of the surrounding environment physically encircling the participants.
[0078] 6. Once the wheel is complete, the symbols, images and text on the wheel should be “unpacked,” or discussed and interpreted, in detail. This step will enable all participants to become familiar with the fill realm of symbols used to create the wheel. It also will help participants understand the symbols in a deeper and more meaningful way.
[0079] The first stage of unpacking involves stepping back and observing the types of icons that were created as well as the similarities between icons. It may be helpful to make a list of all of the participants' responses. The list acts as a “memory log” of responses, so that participants can revisit and analyze a particular statement or figure of speech used to describe a symbol or convey an idea.
[0080] Initially, participants should address the physical characteristics and qualities of the wheel before addressing the conceptual elements and intentions. Are there a lot of colors used in the wheel? Is the wheel flat or very dimensional with much texture? Are the shapes, forms and media similar? Are the icons and symbols used representational, figurative or abstract?
[0081] After noting the physical similarities, participants should address the conceptual elements and intentions. They should describe the music or sounds the symbols and icons evoke. What would these works sound like, if they had a sound (e.g., classical, rock, jazz, rap, new age, tribal)? How would these works be different if they were the size of a room and participants could walk into or through them? How would these works be different if they were four-dimensional; i.e., had a time element to them, like moving kinetic sculptures?
[0082] In the second stage of unpacking, participants should take turns interpreting their creations for the other participants. Participants should explain why they selected the symbols, colors, shapes, etc. that they did. They should also note what other creations are similar to their creations and why. Each aspect of the wheel should be explored in as great depth as possible, with all participants listening closely to the expressions of language and personal stories used in the descriptions.
[0083] 7. Referring now to FIG. 11, to further explore and understand the wheel 10 , spin the spinner 5 twice and note the two categories that the spinner lands on. The participants should then explore the connections between the two categories. It may be helpful to make a list of these connections. For example, if the subject is “leisure time” and the spinner lands on “cooking” and “sports”, the participants should list all the ways in which cooking and sports are similar. Are there ingredients in sports? Is there a chef? Do sports have anything comparable to a cookbook? Are there penalties in cooking? Is a kitchen like a playing field? All of these possibilities should be explored. The more connections, the better; nothing should be seen as too extreme or abstract.
[0084] 8. Referring now to FIG. 12, choose an area of study for enhancement or an object that is of interest to the participants, something from which they wish to extract more meaning. For example, if it's a fifth grade teacher who wishes to enhance the students' knowledge about volcanoes and other eruptive structures in nature, then they should choose that. Once the area of study or object has been chosen, an icon is selected or created which represents it and placed next to the wheel. Here the teacher could place a picture or model of a volcano 90 next to the wheel.
[0085] 9. Begin by spinning the spinner. Whatever category the spinner lands on should be related to the icon representing the area of study or object. In the volcano example, if the subject is “education” and the spinner lands on “social studies, 57 ” relate the volcano to social studies. That is, list all of the ways in which volcanoes are like social events. For example, a particular historical event may be taken, such as the 1991 Los Angeles Riot, or the break-up of the Eastern Bloc nations, and related to the turbulent birth and growth of a volcano.
[0086] Again, participants should begin with the obvious likenesses between these subjects—working from the general information and observation to the specific details. This will produce both general responses such as “war is like an erupting volcano,” to specific ones such as the “the Croats & Serbs are like the lava flow which hasn't yet cooled to form stable land masses (i.e., governments).” This is Step One (connection) of the process.
[0087] The teacher should encourage further discussion by introducing subject matter related to the volcano, such as how a volcano works, how seismic activity can be used to predict a volcanic eruption or how lava changes the landscape around it. All of these can be related back to social upheaval and war. How does the process of war resemble the process of a volcano? How do wars and volcanoes change the landscape around them? What are the conditions in which a volcano—or a war—occur? Can war be predicted or anticipated by studying the technological processes by which volcanic actions are forecasted? What can we learn from one about the other? More importantly, is it possible to stop a volcano and what are the implications of this for stopping war? Through this enhanced discussion, the students will soon be making discoveries concerning the nature of volcanoes, the nature of war and how war and volcanoes are similar in many ways. This is Step Two (discovery) of the process.
[0088] Step Three (invention) of the process involves building upon discoveries and inventing something based on them. For example, the students may discover that the same conditions which prevent a volcano from erupting, may be similar in process to those that prevent a war from occurring (e.g. a certain rock formation which blocks magma flow may resemble a blockade of arms). If the students use the knowledge that they gained to invent a way to cut down on playground fighting, they would be reaching Step Three (invention). If they actually applied this knowledge or used this knowledge to make further inventions, they would be at Step Four (application) of the process.
[0089] 10. Repeat 9. Using the same icon as in number 9, spin the spinner again and relate the new selection to the icon. For example, if the spinner now lands on art, relate art—including, art forms, and techniques of art-making—to volcanoes.
[0090] Note: if the participants ever get stuck on any given connection, spin again. The more they engage in this exercise, the less likely they will be to draw a blank.
[0091] The wheel can be used to move through all levels of the process quickly or slowly. During this process, the wheel enhances and enriches meaning in any subject or area of personal interest. A key to this process is starting with the participant's personal knowledge and life experiences and applying the new area of learning directly back to that base knowledge. The volcano example assumes that the students know something about social studies. If they didn't, the exercise wouldn't be nearly as fruitful.
[0092] Another key involves letting the participants create the wheel themselves, using their base of personal knowledge in the process. Through this method, the participants have ownership of the wheel. This ownership makes it very personal to them and gives them a real stake in shaping the process and product of education. Even the act of deciding what categories to pick-and-choose and what images to place on the wheel teaches invaluable lessons about how to select and make meaning from information. It also shows that information and categorization are not fixed, and that information can be presented and divided in almost infinite ways.
[0093] Another feature of the wheel is that it can be used over time. Participants can continually use it to enhance their knowledge about any subject that they would like to learn about. In the teacher/volcano example, the teacher could reuse the wheel to teach other course content. The wheel should be updated periodically—or completely reformulated—in order to reflect the growth of the participants who created it.
[0094] Referring now to FIG. 13, the steps of the process can be further modified for classroom use by having the participating students physically create their own wheel. One way to do this is to draw an idea web 100 on the blackboard. The students can brainstorm categories 102 , 104 , 106 , 108 , 110 , 112 , 114 , 116 for the given subject and the teacher places these categories of ideas onto the web. The students could then distill the web into the best eight to twelve main categories, which should also be listed on the board.
[0095] Students would then have the opportunity to divide themselves into groups and create images, text and models for a category of their choice. A group of students could also be assigned to building the wheel itself. This latter assignment would involve the students having to design the wheel, select the materials and build it.
[0096] Prior to doing the wheel, the teacher should explain to the students that they will be designing and using their own learning system. The wheel will be used for seeing the relationships between things, connecting things and discovering the meaning of these connections. How they go about creating this learning system is up to them, from how it looks to what is on it.
[0097] It might also be helpful to show pictures of how humans have used wheels throughout history, such as early wheels with carts, Indian prayer wheels and even modern, metaphorical wheels as in the popular television game “The Wheel of Fortune.” Teachers may even create their own wheels and show these to the class. The discussion of all of these wheels will put what the students are doing in perspective while also demonstrating the versatility of wheels.
[0098] Participants may also invent games based on the wheel. This includes the creation of scoring systems and rules of play. Encourage the participants to be as creative as they can with the creation of the wheel. The wheel can take many forms and be simple and complicated in form or playing rules. Experiment with the wheel, noting how each different construction, tells a different story. Another feature of the wheel is that it can be used over a long period. Participants can continually use it to engage and enhance any new information, subject or problem that they would like to. The wheel should be updated periodically—or completely reformulated—in order to reflect the growth of the participants who created it.
[0099] While the exemplary preferred embodiment of the present invention is described herein with particularity, those having ordinary skill in the art will recognize various changes, modifications, additions, and applications other than those specifically described herein, and may adapt the preferred embodiment and methods without departing from the spirit of the invention.
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The present invention provides a method and apparatus for enhancing cognitive functioning and its manifestation into physical form and translation into useful information for improving functioning in human experience, for example, business, academic or personal endeavors.
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PRIORITY CLAIM
This Application claims the benefit of priority from U.S. Provisional Application No. 60/961,936, filed on Jul. 25, 2007, that is incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention provides an automatic via creation tool for use with electronic design automation (“EDA”) systems used in integrated circuit design. Specifically, this invention relates to the automatic creation of via connections between overlapping conducting traces when those conducting traces are part of the same net.
2. Related Art
As the complexity, efficiency and robustness requirements in electrical devices like mobile phones, satellite receivers and wireless local area networks increase, more efficient and accurate circuit design of such devices are needed. To reduce product development schedules and make the design work as efficient as possible, it is important to automate this work, too. This design work is often performed by means of computer and associated software in which case the design is stored into the memory of a computer as a virtual representation.
Circuit design typically involves several steps. Usually the design starts with some schematic representation of the circuit that can then be simulated to observe and manipulate the behavior of the design. When the design on a schematic level is found working, a layout of the circuit is produced. The layout is usually a collection of metallizations, routes or traces of other conducting material interconnecting the various electrical components of the circuit design. These conducting traces are fabricated e.g. over and into a printed circuit board, into an integrated circuit or a ceramic slab or other such technology, possibly in several layers.
In designing modern electronic circuits, there are increasing numbers metallization layers that are used to interconnect the various components of the circuit. In RF and high frequency circuits in particular, the interconnect routing and connecting of these components is performed interactively using graphical layout editors. When connecting between two conducting layers or between a conducting layer and the pin of a device, a via or contact structures must be inserted to make an electrical connection between the two. Finding the locations of these connection areas by visual inspection can be very time consuming and error prone for the circuit designer, especially if the circuit contains many components and connections. Once found, creating the via or contact structures to make a connection is also very tedious and error prone. To a circuit designer, it is advantageous to automate the creation of the via structure procedure as much as possible.
Prior art methods of via connection between conducting traces on different layers of an integrated circuit are available commercially in other electronic design automation software, but their design is very limited. In other popular commercial custom electronic layout editors such as Cadence's VirtuosoXL, vias can be inserted between conducting layers, but require a continuous path description and/or an explicit request in order to insert a via into the design. In automatic place and route software such as Magma and Synopsys P&R products, vias are automatically inserted between layers on a continuous routed path. This invention does not require the user to identify the need for or a requirement that the user request insertion a via connection between conducting paths that happen to overlap during the interactive custom layout process. This invention teaches the automatic creation of the via.
SUMMARY
This invention is directed to a methodology of detecting crossings of conductive traces on different layers of an integrated circuit or a conducting trace over a device contact stored into the memory of a computer, corresponding to the same galvanic potential or same “net” and then automatically placing, correct-by-construction, a via connection between the traces, or the trace and device contact, to short circuit them. The via structure will not be created if it will create a short-circuit to a conducting trace not associated with the net in question. By connecting traces on different layers using automatically created via structures so as not to short circuit other net traces, errors are eliminated and design cycles times are reduced when compared to creating manual via connections.
This invention also teaches the automatic placement of the via structure without the need to specify which metal layout, needs connecting on another metal layer in the integrated circuit design. This invention routes a path according to a net of predefined circuit components. If that route path crosses another path on another layer in the circuit layout that is part of the same net, a via is automatically created based on the via creation rules set by the user. Thus, the system will automatically recognize when two metal layers cross that are part of the same net, vias are created according to the design rules specified by the user.
There are a number of useful features that can be applied to the automatic via structure creation. For example, an interactive mode allowing easily resizing of the via structure by the use of familiar control handles in the graphical user interface display. The invention allows for the creating of certain rules such as preventing automatic via creation when the trace does not come into overlap contact with a pin structure on a layer above or below the trace. Certain user defined rules may allow for the enforcement of vias created according to a minimum size, the size covers the pin-route intersection, or the entire pin area.
Other features include creating via and keeping the structure size inside the size dimensions of the trace including forcing a rectangular via structure to orient in the horizontal or vertical position. Optionally, the user can periodically override selected features of the automatic via creation rules.
Other systems, methods, features, and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
DETAILED DESCRIPTION OF THE DRAWINGS
The components in the figures are not necessarily to scale, emphasis being placed instead upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 is a top view of a simplified layout circuit diagram showing the interrelationship with a circuit schematic diagram with components connected by trace lines and via structures.
FIG. 2 is a top view of a simplified layout circuit diagram showing the resizing of the via structure by expansion handles.
FIG. 3 is a top view of a simplified layout circuit diagram showing different circuit elements of a physical net connected by trace lines and via structures.
FIG. 4 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 5 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 6 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 7 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 8 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 9 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 10 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 11 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 12 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure.
FIG. 13 is a perspective view of a via cap structure.
DETAILED DESCRIPTION
This invention assumes that the system simulator knows each polygon or circuit component in the net without running any other tools such as a layout versus schematic (“LVS”) tool or any explicit definition of where a via needs to be place in the layout as a single path definition by place and route tools. In traditional layout editors, the user has to inquire as to whether or not to insert a via between two different pieces of metals located on different layers of the integrated circuit layout. The layout is usually a collection of layers of metallizations separated by other layers while having routes or traces of conducting material interconnecting the various electrical components of the design. Typically, the creation of vias can be made in integrated circuit designs but it can also be created in the design of printed circuit boards.
The circuit design implicitly contains the knowledge of the nets allocated to the circuit components. The integrated data model understands the connectivity in the model. As soon as the two metal layers overlap, the system creates a via structure according to the user defined rules. This automatic creation of vias eliminates the omission of the via structure by the user, placement in the wrong place within the layout or the creation of an improperly sized via structure violating system requirements. This automatic via creation make the via creation correct by construction connectivity. The system knows that the metal layers overlap from the schematic design. Nets are used to connect components in the schematic design. Thus, when the layout is created the system understands the location of the pins and the required connectivity from the creation of the nets. In this system, it is inherent that such connectivity exists. In prior art systems, it is possible for the connectivity and schematic to be inconsistent. In this system, the connectivity and schematic will always be consistent.
Via inter-connect is prohibited if a via is inserted when a second net interferes with the creation of a via that is large enough to interfere with the second net trace or component. Stray voltage can create a short circuit that is undesirable. An error checking feature may alert the user that a short circuit may exist and guide the user to the location in the layout where the problem exists.
In the physical layout of an integrated circuit, layers of insulators and metals are deposited forming the complex structure of the integrated circuit. This three dimensional layered structure is best represented by a layout diagram where the components are on located on a first level. Metal traces can also be located on the first layer as well as on the third layer. Insulating material is often deposited on the second layer and via structures created connecting the metal traces of the first and third layers so that electrical connectivity exists through the second insulating layer. Integrated circuit design is well known in the art and a plurality of layers may exist forming the overall circuit design.
FIG. 1 is a top view of a simplified layout circuit diagram showing the interrelationship with a circuit schematic diagram with components connected by trace lines and via structures. In the circuit schematic, components have pins 100 , 102 , 104 and 106 and comprise a simplified circuit. Components 100 , 102 , 104 and 106 are interconnected along routes 1 ( 108 ), route 2 ( 110 ), route 3 ( 112 ) and route 4 ( 114 ). A node 116 marks the interconnection of the three routes 108 , 110 and 112 . For route 112 , design rules define the route as a series of parameters 118 regarding the paths of the traces.
In the layout diagram of FIG. 1 corresponding to the schematic diagram, components 100 and 102 are located on the first level of the integrated circuit and components 104 and 106 are located on a second level. The trace lines of route 1 ( 108 ), rout 2 ( 110 ) and route 3 ( 112 ) are located on the same level. Route 4 ( 114 ) is located on an upper level. In a semiconductor, these two paths are located on different layers. Where their traces overlap, an opportunity is established for the creation of a via structure connecting the components 100 , 102 and 104 together assuming they are all on the same net. Once the trace of route 3 ( 112 ) overlaps with pin 104 , a via structure can be automatically created. Once the via is created, the circuit is complete.
FIG. 2 is a top view of a simplified layout circuit diagram showing the resizing of the via structure by expansion handles 200 . Once the via structure is created 202 in the layout design, control handles 200 can allow a user to resize the via structure increasing the size of the via 202 or creating a via cap 204 and forming a plurality of via structures 206 .
FIG. 3 is a top view of a simplified layout circuit diagram showing different circuit elements of a physical net connected by trace lines and via structures. Electronic component 300 comprises pins P1 ( 302 ) and P2 ( 304 ). Electronic component 306 comprises pin P1 ( 308 ). Electronic component 310 comprises pins P1 ( 312 ) and P2 ( 314 ) forming structure 316 , and pin P3 ( 318 ). Connecting P2 ( 304 ), P1 ( 308 ) and structure 316 having pins P1 ( 312 ) and P2 ( 314 ) forms a net 320 . Once the net 320 is created, connecting metal traces between electronic components 300 , 306 and 310 allows the system to automatically permit for the accurate and correct creation of via structures.
FIG. 4 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. The metal trace route 400 is represented in the bottom of the figure. When the metal trace route is drawn in a system such that the trace route 400 overlaps a pin 402 located on another layer of the semiconductor, a via structure 404 is automatically created.
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the size of the via structure is controlled by a user selecting to enforce the minimum size rule 408 . This rule ensures that the size of the via structure is no larger than the minimum required. Should the user not select to enforce minimum size via, the via structure created will fill to the size limits of the other user selected rules. Another rule controlled by the user is whether the via will cover the pin route intersection 410 . This sizing rule is illustrated in the layout located below the menu layout 406 where the via 404 covers the entire area of the metal trace 400 overlap with the pin 402 .
FIG. 5 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. The metal trace route 500 is represented in the bottom of the figure. When the metal trace route is drawn in a system such that the trace route 500 located on a second layer 502 overlaps a pin 504 located on a first layer 506 of the semiconductor, a via structure 508 is automatically created.
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the size of the via structure is controlled by a user selecting to enforce the minimum size rule 408 . This rule ensures that the size of the via structure is no larger than the minimum required. Should the user not select the rule enforce minimum size via, the via structure created will fill to the size limits of the other user selected rules. Another rule controlled by the user is whether the via will cover the entire pin area 510 . This sizing rule is illustrated in the layout located below the menu layout 406 where the via 508 covers the entire area of the pin overlap 512 .
FIG. 6 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. The metal trace route 600 is represented in the bottom of the figure. When the metal trace route is drawn in a system such that the trace route 600 located on a second layer overlaps a pin 602 located on a first layer of the semiconductor, a via structure 604 is automatically created.
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the size of the via structure is controlled by a user selecting to enforce the minimum size rule 408 . This rule ensures that the size of the via structure is no larger than the minimum required. Should the user not select the rule enforce minimum size via, the via structure created will fill to the size limits of the other user selected rules. Another rule controlled by the user is whether the via will cover the minimum via area 606 . This sizing rule is illustrated in the layout located below the menu layout 406 where the via 604 covers the minimum area of the pin overlap 604 .
FIG. 7 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. The metal trace route 700 is represented in the bottom of the figure. When the metal trace route 700 is drawn in a system such that the trace route 700 located on a second layer overlaps a pin 702 located on a first layer of the semiconductor, a via structure 704 is automatically created.
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the size of the via structure is controlled by a user who can select the pin route position such as preference to the creation of the via parallel to the line 706 of the route trace 700 . This rule ensures that the orientation of the via structure is located in the same parallel orientation as the trace route.
FIG. 8 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. The metal trace route 800 is represented in the bottom of the figure. When the metal trace route 800 is drawn in a system such that the trace route 800 located on a second layer overlaps a pin 802 located on a first layer of the semiconductor, a via structure 804 is automatically created.
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the size of the via structure is controlled by a user who can select the pin route position such as preference to the creation of the via perpendicular to the line 804 of the route trace 800 . This rule ensures that the orientation of the via structure is located in the perpendicular orientation as the trace route.
FIG. 9 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. Here, trace route 900 is located on a second layer of an integrated circuit while trace route 902 is located on a first layer. Assuming that the two trace routes are on the same net, when trace route 900 is drawn such that there exists over lap of the area defined by x 904 and y 906 , a via is automatically created. Because of the sizing requirements of the via, the via created may need to be larger than the area of overlap defined by x 904 and y 906 . In the example where route trace 908 overlaps with route trace 910 , the overlap may need to create a via having dimensions that are greater than the area of the overlap. This larger cross sectional area of the via is represented by the area 912 .
Associated with the automatic via creation tool is a menu layout 406 for selecting various rules for forming the automatic via structures. In the menu layout 406 , the orientation and sizing of the via structure is controlled by the user. The user has the option of keeping the via inside the route trace 914 . Also, the user can select a preference rule of orienting the via horizontally inside the route trace 916 . Thus, the via can be automatically be resized to the area defined by z 918 and y 906 .
FIG. 10 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. As an alternative to the menu layout 406 option for orienting the via in the horizontal dimension inside the route trace 1004 , the user can select to orient the via in the vertical direction 1000 . Thus, when the route trace 1002 on the second layer of the integrate circuit overlaps the route trace 1004 located on a first layer, but within the same net, the via may be automatically created 1006 in the vertical direction.
FIG. 11 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. In the layout 406 , the user can select to override for short segments 1100 the option to keep the via inside the route trace 1102 and orient the via in the horizontal 1104 or vertical 1106 dimension. Thus, the where normally when the route trace 1108 located on a second layer of an integrated circuit overlaps the route trace 1110 on the same net, the via would normally be oriented in the vertical position 1112 assuming the user had selected the keep inside route option 1102 and prefer vertical orientation 1106 . If the user selected the override option 1100 , the via would be oriented in the horizontal orientation 1114 .
FIG. 12 is a top view of a trace line and pin structure corresponding to a graphical user interface of a system layout option menu structure. Another option for a user in layout 406 is for a prohibition of the automatic via creation when the route trace is not overlapping a pin 1200 . Normally, when route trace 1202 approaches and then overlaps route trace 1204 , a via is automatically created. However, if the user selects the option prohibiting the automatic via creation unless the route trace overlaps a pin 1200 , then no via is created.
FIG. 13 is a perspective view of a via cap structure. When a route trace 1300 on a first layer 1302 overlaps a pin or a route trace connected to the same net but located on another layer. The via structure may need to be larger in width 1304 than the route trace 1300 . As such, the via may also need to be formed with a plurality of columns 1306 . In some instances depending upon the design rules, the via structure may require alternating layers of columns 1306 and layers 1308 according to the design criteria of the structure.
While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention.
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This invention is directed to a methodology of creating and detecting crossings of conductive traces on different layers of an integrated circuit or a conducting trace over a device contact during a system. Values are stored by the system simulator corresponding to the galvanic potential or same “net,” and then by a set of rule based instructions the vias are automatically displayed, correct-by-construction, and via connections between the traces, or the trace and device contact, to short circuit the paths. The via structure will not be created if it will short-circuit a conducting trace not associated with the net in question. By connecting traces on different layers using automatically created via structures so as not to short circuit other net traces, errors are eliminated and design cycles reduced when compared to a manual design scheme of inserting via connections. There is a number of useful variations that can be applied to the via structure automatically created. There is also an interactive mode which allows the via to be easily resized by the use of familiar control handles.
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RELATED CASES
[0001] I claim priority from my earlier-filed applications U.S. Ser. No. 61/007,117 filed Dec. 11, 2007 and U.S. Ser. No. 60/887,657 filed Feb. 1, 2007, each of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] this invention relates to treating alcohol and/or other substance abuse or dependence, and to compositions used for such treatment.
BACKGROUND
[0003] Substance use disorder (i.e., substance abuse or substance dependence) occurs commonly in patients with schizophrenia and worsens its clinical course. Commonly abused substances include alcohol, cannabis and cocaine, and such abuse occurs at a rate of greater than 3 times the rate seen in the general population. Moreover, tobacco smoking occurs in over 75% of the patients with schizophrenia. The standard or typical antipsychotic medications commonly used to treat schizophrenia do not appear to be helpful in lessening the use of substances in this population. Data from our group and others, however, suggest that the atypical antipsychotic clozapine appears to limit alcohol, cannabis and cocaine abuse in this population, but its toxicity limits widespread use 1 . 1 Green, A. I., et al., Clozapine for comorbid substance use disorder and schizophrenia: do patients with schizophrenia have a reward-deficiency syndrome that can be ameliorated by clozapine? Harv Rev Psychiatry, 1999. 6(6): p. 287-96; Green, A. I., et al., Substance abuse and schizophrenia: Pharmacotherapeutic intervention. J Subst Abuse Treat, 2008. 34(1): p. 61-71; Brunette, M. F., et al., Clozapine use and relapses of substance use disorder among patients with co-occurring schizophrenia and substance use disorders. Schizophr Bull, 2006. 32(4): p. 637-43. Drake, R. E., et al., The effects of clozapine on alcohol and drug use disorders among patients with schizophrenia. Schizophr Bull, 2000. 26(2): p. 441-9; Green, A. I., et al., Alcohol and cannabis use in schizophrenia: effects of clozapine vs. risperidone. Schizophr Res, 2003. 60(1): p. 81-5; Zimmet, S. V., et al., Effects of clozapine on substance use in patients with schizophrenia and schizoaffective disorder: a retrospective survey. J Clin Psychopharmacol, 2000. 20(1): p. 94-8; US 2006-0189599.
SUMMARY
[0004] We have discovered, based on a series of experiments in animals, that medications exhibiting a combination of dopamine D2 receptor blockade (typically a weak blockade) with norepinephrine reuptake inhibition (i.e., inhibition of the norepinephrine transporter) are useful treatments for patients with, or at risk for, alcohol and/or other substance abuse/dependence (including those patients who have both alcohol and/or other substance abuse/dependence with a co-occurring psychiatric disorder such as schizophrenia or bipolar disorder). The presence of a norepinephrine alpha 2 receptor blockade (also a property of clozapine) in such a medication (in combination with the other effects, i.e., dopamine D2 receptor blockade and norepinephrine reuptake inhibition) may also be helpful in limiting alcohol (or other substance) abuse in such individuals. Substances of abuse in this context include not only alcohol but also opioids, including heroin and oxyContin®, cannabis, cocaine, amphetamines, tobacco and others.
[0005] Another aspect of the invention features combinations of medications exhibiting the above-described activities. The combinations include: a) for the dopamine D2 receptor antagonist activity, risperidone, paliperidone, haloperidol, olanzapine, quetiapine, ziprasidone, aripiprazole, fluphenazine or other drugs with D2 receptor blockade (antagonistic) properties; b) for norepinephrine reuptake blockade (inhibition), desipramine or reboxetine, or other drugs with norepinephrine reuptake inhibition properties; c) for alpha 2 antagonist activity, idazoxan and yohimbine, or other drugs with norepinephrine alpha 2 receptor antagonistic effects.
[0006] Compositions having combinations of medications, as well as methods of therapy using combinations of medications, are featured, in which the multiple activities of the medication are provided by more than one specific medicinal compound.
[0007] Accordingly, the invention generally features methods of treating and or preventing substance abuse/dependence, and alcohol abuse/dependence in particular. The medications used in the invention are described above. The patients to be treated according to the invention are those with a history or a risk of alcohol or substance abuse/dependence.
[0008] The compounds to be administered can be formulated into a suitable pharmaceutical preparation by known techniques, for example well known tablet and capsule formulations. Such formulations typically comprise the active agent (or the agent in a salt form) and a pharmaceutically acceptable carrier. As used herein the language “pharmaceutically acceptable carrier” is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the compositions is contemplated. Supplementary active compounds can also be incorporated into the compositions.
[0009] A pharmaceutical composition of the invention is formulated to be compatible with its intended route of administration. Examples of routes of administration include oral, intravenous, intradermal, subcutaneous, transdermal (topical), transmucosal (e.g. intranasal), and rectal.
[0010] By far the most convenient route of administration is oral (ingestion). Oral compositions generally include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.
[0011] In one embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art.
[0012] It is especially advantageous to formulate oral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals.
[0013] The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration.
DESCRIPTION OF DRAWINGS
[0014] FIG. 1 (PRIOR ART) is a graph depicting the results of the experiment reported in Example 1: Clozapine and Halperidol on Alcohol Drinking in Hamsters, taken from Green, A. I., et al., Clozapine reduces alcohol drinking in Syrian golden hamsters. Psychiatry Res, 2004. 128(1): p. 9-20.
[0015] FIG. 2 is a graph depicting the results of the experiment reported in Example 2: Chronic Clozapine on Alcohol Drinking in Hamsters.
[0016] FIG. 3 is a graph depicting the results of the experiment reported in Example 3: Clozapine and Haloperidol on Initiation of Alcohol Drinking in P-rats.
[0017] FIG. 4 is a graph depicting the results of the experiment reported in Example 4: Clozapine and Haloperidol on Initiation of Alcohol Drinking in P-Rats.
[0018] FIG. 5 is a graph depicting the results of the experiment reported in Example 5: Clozapine and Raclopride on Initiation of Alcohol Drinking in Hamsters.
[0019] FIG. 6 is a graph depicting the results of the experiment reported in Example 6: Haloperidol and Desipramine on Alcohol Drinking Hamsters.
[0020] FIG. 7 is a graph depicting the results of the experiment reported in Example 7: Haloperidol, Desipramine and Idazoxan on Initiation of Alcohol Drinking in P-Rats.
[0021] FIG. 8 is a graph depicting the results of the experiment reported in Example 8: Haloperidol, Desipramine and Idazoxan on Initiation of Alcohol Drinking in P rats.
[0022] FIG. 9 is a graph depicting the results of the experiment reported in Example 9: Risperidone and Desipramine on Alcohol Drinking in Hamsters.
[0023] FIG. 10 is a graph depicting the results of the experiment reported in Example 10: Risperidone and Desipramine on Alcohol Drinking in Hamsters.
[0024] FIG. 11 is a graph depicting the results of the experiment reported in Example 11: Risperidone and Desipramine on Initiation of Alcohol Drinking in P-rats.
DETAILED DESCRIPTION
[0025] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
[0026] The following Examples provide a detailed description of the invention.
[0027] General Methods
[0028] The animal models that we have used in our experiments include the Syrian golden hamster (Mesocricetus auratus, Harlan Inc.) and the alcohol preferring P rat (Indiana University). Both animals prefer an alcohol solution over water when given a choice between the two fluids and they consume large quantities of alcohol on a daily basis. However, while the hamster is an out-bred rodent, which has a natural preference for alcohol, the P rat has been bred over multiple generations through the selective mating of rats with high alcohol preference. Both the hamster and the P rat have been used by alcohol researchers to screen medications for treatment of alcoholism. Keung, W. M. and B. L. Vallee, Daidzin and daidzein suppress free-choice ethanol intake by Syrian golden hamsters. Proc Natl Acad Sci U S A, 1993. 90(21): p. 10008-12; McBride, W. J. and T. K. Li, Animal models of alcoholism: neurobiology of high alcohol-drinking behavior in rodents. Crit Rev Neurobiol, 1998. 12(4): p. 339-69.
[0029] Two types of studies were conducted in hamsters and P rats. The first type of study assessed the ability of drugs (or drug combinations) to decrease chronic alcohol drinking in these animals. In these studies, drug treatment began after the animals had been drinking alcohol for several weeks. The second type of study assessed the effects of drugs (or drug combinations) on the ability of the animals to initiate alcohol drinking. The animals in the latter type of study received drug treatment several days prior to and during the initial weeks of exposure to alcohol. All animals were given 24 hours/day access to 10-15% alcohol and water in two separate drinking bottles. Groups of animals (n=6-10/group) received daily injections of the specific drug or drug combination or vehicle for up to 4 weeks.
EXAMPLES 1 (PRIOR ART) AND 2
[0030] In one study, we demonstrated that clozapine (CLOZ), but not the typical antipsychotic drug haloperidol (HAL), dramatically decreased chronic alcohol drinking in the Syrian golden hamster more than vehicle (VEH) ( FIG. 1 ). Green, A. I., et al., Clozapine reduces alcohol drinking in Syrian golden hamsters. Psychiatry Res, 2004. 128(1): p. 9-20. No dose of haloperidol tested had an effect on alcohol drinking in the hamster. Moreover, in another study with unpublished data, as seen in FIG. 2 , we demonstrated that this effect of clozapine is chronic, lasting at least 1 month.
EXAMPLES 3 AND 4
[0031] In another study, we demonstrated that clozapine (CLOZ) also decreases the initiation of alcohol drinking in the alcohol-preferring P rat, as compared to vehicle (VEH) and haloperidol (HAL) ( FIG. 3 ). This can be seen most dramatically by looking at alcohol preference (the % of liquid consumed that comes from the alcohol bottle)— FIG. 4 . Clozapine dramatically decreases alcohol preference during the initiation of alcohol drinking.
EXAMPLE 5
[0032] In Example 5 ( FIG. 5 ), we have demonstrated that clozapine (in this case a low dose) also blunts the initiation of alcohol drinking in the hamster. We have also demonstrated in FIG. 5 that by adding raclopride (RACL, a potent D2/D3 receptor antagonist) to a low dose of clozapine, this effect of clozapine on the initiation of alcohol drinking by the hamster is lost. This finding is consistent with our proposition that clozapine's effect on alcohol drinking is at least partially related to its weak D2 receptor blocking ability.
EXAMPLE 6
[0033] In the hamster, as noted above, haloperidol has very little effect on chronic alcohol drinking. However, if the norepinephrine reuptake inhibitor desipramine (DMI) is added to low dose haloperidol (HAL), it decreases the alcohol drinking more than does desipramine alone ( FIG. 6 ). This supports our proposition that a weak dopamine D2 receptor blocker plus a norephinephrine reuptake inhibitor decreases alcohol drinking.
EXAMPLES 7 AND 8
[0034] Low dose haloperidol has minimal ability to blunt the initiation of alcohol drinking by the P rat. However, adding the alpha 2 receptor blocker idazoxan (IDAZ) to low-dose haloperidol modestly increases the ability of haloperidol to blunt the initiation of alcohol drinking. However, if the norepinephrine reuptake inhibitor desipramine (DMI) is added these two drugs, it dramatically increases the ability of them to decrease alcohol drinking and alcohol preference ( FIGS. 7 and 8 ). This effect is consistent with our proposition that a weak dopamine D2 receptor blocking effect coupled with a potent norepinephrine alpha 2 receptor blocker and a norepinephrine reuptake inhibitor will decrease alcohol drinking.
EXAMPLES 9-11
[0035] Lastly, we have demonstrated that a low dose of risperidone (RISP), a drug with a potent dopamine D2 receptor blocking ability, has only a modest effect on alcohol drinking in both the hamster (on chronic drinking) and the P rat (on the initiation of alcohol drinking). We have further shown that the addition of the norepinephrine reuptake inhibitor desipramine (DMI) to risperidone causes risperidone to limit alcohol drinking. Moreover, this effect, which we have seen in both the hamster and the P rat, is more dramatic than with desipramine alone ( FIGS. 9 , 10 , and 11 ). This effect is consistent with our proposition that a weak D2 receptor blocker (weak because of the low dose of risperidone) coupled with a norepinephrine reuptake inhibitor will decrease alcohol drinking. Moreover, since risperidone is also a blocker of the norepinephrine alpha 2 receptor (as well as the D2 receptor), its blockade of the alpha 2 receptor (in combination with its D2 receptor blockade) may contribute to allowing the norephinephrine reuptake inhibitor desipramine to convert risperidone into a drug that decreases alcohol drinking.
[0036] We conclude that the combination of a weak dopamine dopamine D2 receptor blocker (antagonist) and a potent norepinephrine reuptake inhibitor may produce a drug that shares with clozapine the ability to limit alcohol drinking. We further conclude that addition of a norepinephrine alpha 2 receptor blocker (antagonist) may contribute to the ability of a composition with these characteristics to limit alcohol drinking. Our findings suggest medications containing these properties as a therapeutic agent in patients with schizophrenia and alcohol or substance abuse/dependence. Since the medications that we have tested limit alcohol drinking in animal models of alcoholism, and since, moreover, patients with alcohol use disorder and substance use disorder may share some biologic characteristics (i.e., disordered brain reward circuitry) of patients with schizophrenia, we conclude that a medication with these characteristics should be effective as well in patients with alcohol use disorder and/or substance use disorder who do not have schizophrenia.
[0037] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
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Methods of treating and or preventing substance abuse/dependence, and alcohol abuse/dependence in particular. Combinations of medications are also disclosed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. application Ser. No. 10/049,438, now U.S. Pat. No. 7,208,565, filed on May 30, 2002 which is a U.S. National Phase of PCT/JP2000/05728 filed on Aug. 24, 2000 claiming priority of Japanese Patent Application No. 11-237485 filed on Aug. 24, 1999, the disclosures of which applications are incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a polyester polymerization catalyst, polyester produced by using the same and a process for producing polyester and in particular to an antimony compound-free novel polyester polymerization catalyst, polyester produced by using the same and a process for producing polyester.
2. Prior Art
Polyester, particularly polyethylene terephthalate (abbreviated hereinafter into PET), is superior in mechanical and chemical properties and applied to various uses such as fibers for clothes and industrial materials, various films such as packaging films and magnetic tapes and sheets, and molded articles such as bottles and engineering plastics.
PET is obtained industrially by esterification or transesterification of terephthalic acid or dimethyl terephthalate with ethylene glycol thereof to produce bis(2-hydroxyethyl) terephthalate and subsequent polycondensation thereof with a catalyst at high temperature in vacuo. As the catalyst used in this polycondensation, antimony trioxide is widely used. Antimony trioxide is a catalyst which is inexpensive and superior in the catalytic activity, but since an antimony metal is precipitated during polycondensation, there is the problem of gray discoloration and formation of insoluble particles in PET. Further, a problem with the safety of antimony is recently noted from an environmental viewpoint. Under these circumstances, there is demand for polyester containing no or little antimony.
While using antimony trioxide as the polycondensation catalyst, an attempt at inhibiting occurrence of gray discoloration and formation of insoluble particles in PET has been made. In Japanese Patent No. 2666502, for example, antimony trioxide and bismuth and selenium compounds are used as the polycondensation catalyst, whereby formation of gray insoluble particles in PET is inhibited. Further, Japanese Unexamined Patent Publication No. 291141/1997 describes that when antimony trioxide containing sodium and iron oxides is used as the polycondensation catalyst, precipitation of an antimony metal is inhibited. However, these polycondensation catalysts cannot achieve the object of obtaining polyester containing no or little antimony.
A polycondensation catalyst substituted for antimony trioxide has also been investigated. In particular, a titanium compound represented by tetraalkoxy titanate has already been proposed, but there is the problem that PET produced using this compound is significantly discolored and easily thermally degraded.
As an attempt to overcome such problem when tetraalkoxy titanate is used as the polycondensation catalyst, for example Japanese Unexamined Patent Publication No. 116722/1980 has proposed a method of using tetraalkoxy titanate with a cobalt salt and a calcium salt. Further, Japanese Unexamined Patent Publication No. 73581/1996 has proposed a method of using tetraalkoxy titanate simultaneously with a cobalt compound as the polycondensation catalyst and simultaneously using a optical brightener. By these proposes, the discoloration of PET is reduced when tetraalkoxy titanate is used as the polycondensation catalyst, but effective inhibition of thermal degradation of PET has not been achieved.
As a polycondensation catalyst which is substituted for antimony trioxide and overcomes such problem when tetraalkoxy titanate is used, a germanium compound has been practically used, but this catalyst has the problem that it is very expensive and that the catalyst easily evaporates from the reaction system to the outside so that the concentration of the catalyst in the reaction system is changed thus making control of polymerization difficult.
It is known that aluminum compounds are generally inferior in the catalytic activity. Among the aluminum compounds, aluminum chelate compounds are reported to have a higher catalytic activity as a polycondensation catalyst than other aluminum compounds, but the catalytic activity is not practically sufficient as compared with the antimony compounds and titanium compounds described above.
This invention provides a novel polycondensation catalyst other than antimony compounds, polyester produced by using the same and a process for producing polyester.
SUMMARY OF THE INVENTION
The present inventors made extensive examination for solving the problems described above, and as a result, they surprisingly found that as a polycondensation catalyst, an aluminum compound, though being originally inferior in the catalytic activity, came to have a sufficient activity by allowing a phosphorus compound to be coexistent therewith, thus arriving at this invention. When the polycondensation catalyst of this invention is used, polyester superior in qualities can be obtained without using the antimony compound.
That is, this invention provides a polyester polymerization catalyst, which comprises an aluminum compound and a phosphorus compound, polyester produced by using the same and a process for producing polyester, as a method of solving the problems above.
This invention provides a novel polycondensation catalyst other than antimony compounds, polyester produced by using the same, and a process for producing polyester. The polycondensation catalyst of this invention is a polyester polymerization catalyst, which comprises an aluminum compound and a phosphorus compound, as follows:
{circle around (1)} a polyester polymerization catalyst, which comprises an aluminum compound and a phosphorus compound; {circle around (2)} the polyester polymerization catalyst according to the above-described {circle around (1)}), wherein the phosphorus compound is at least one compound selected from the group consisting of a phosphonic acid based compound, a phosphonic acid based compound, a phosphine oxide based compound, a phosphorous acid based compound, a phosphinous acid based compound, and a phosphine based compound; {circle around (3)} the polyester polymerization catalyst according to the above-described {circle around (1)}, wherein the phosphorus compound is at least one phosphonic acid based compound; {circle around (4)} the polyester polymerization catalyst according to any one of the above-described {circle around (1)} to {circle around (3)}, wherein the phosphorus compound is a compound having an aromatic ring structure; {circle around (5)} the polyester polymerization catalyst according to the above-described {circle around (1)}, wherein the phosphorus compound is at least one compound selected from the group consisting of the compounds represented by the following Formulae (1) to (3):
P(═O)R 1 (OR 2 )(OR 3 ) (Formula 1)
P(═O)R 1 R 4 (OR 2 ) (Formula 2)
P(═O)R 1 R 5 R 6 (Formula 3)
(wherein R 1 , R 4 , R 5 and R 6 independently represent hydrogen, a C 1-50 hydrocarbon group, and a C 1-50 hydrocarbon group containing a hydroxyl group, a halogen group, an alkoxy group or an amino group, and R 2 and R 3 independently represent hydrogen and a C 1-10 hydrocarbon group, provided that the hydrocarbon group may contain an alicyclic structure or an aromatic ring structure.);
{circle around (6)} the polyester polymerization catalyst according to the above-described {circle around (5)}, wherein each of R 1 , R 4 , R 5 and R 6 is a group having an aromatic ring structure; {circle around (7)} the polyester polymerization catalyst according to any one of the above-described {circle around (1)} to {circle around (6)}, characterized in that one or more metals and/or metal compounds selected from the group consisting of alkali metals or compounds thereof and alkaline earth metals or compounds thereof are coexistent therewith; {circle around (8)} polyester produced by using a catalyst described in any one of the above-described {circle around (1)} to {circle around (7)}; and {circle around (9)} a process for producing polyester which comprises using a catalyst described in any one of the above-described {circle around (1)} to {circle around (7)} in producing polyester.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The aluminum compound constituting the polycondensation catalyst of this invention includes, but is not limited to, e.g. carboxylates such as aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate and aluminum salicylate, inorganic acid salts such as aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate and aluminum phosphonate, aluminum alkoxides such as aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum iso-propoxide, aluminum n-butoxide and aluminum t-butoxide, aluminum chelate compounds such as aluminum acetylacetonate, aluminum acetylacetate, aluminum ethyl acetoacetate, and aluminum ethyl acetoacetate di-iso-propoxide, organoaluminum compounds such as trimethyl aluminum and triethyl aluminum and partially hydrolyzates thereof, as well as aluminum oxides, metal aluminum, etc. Among these, the carboxylates, inorganic acid salts and chelate compounds are preferable, among which aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferable.
The amount of the aluminum compound used in the invention is preferably 5×10 −7 to 0.01 mole, more preferably 1×10 −6 to 0.005 mole, relative to the number of moles of all constitutive units of carboxylic acid components such as dicarboxylic acid and polyfunctional carboxylic acid components in the resulting polyester.
The phosphorus compound constituting the polycondensation catalyst of the invention is not particularly limited, but at least one compound selected from the group consisting of a phosphonic acid based compound, a phosphonic acid based compound, a phosphine oxide based compound, a phosphorous acid based compound, a phosphinous acid based compound, and a phosphine based compound is preferably used for a significant effect of improving the catalytic activity. Among these, at least one phosphonic acid based compound is preferably used for a particularly significant effect of improving the catalytic activity.
The phosphonic acid based compound, phosphonic acid based compound, phosphine oxide based compound, phosphorous acid based compound, phosphinous acid based compound and phosphine based compound mentioned in the invention refer respectively to compounds having the structures shown in the following Formulae (4) to (9):
The phosphonic acid based compound in this invention includes e.g. dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate and diethyl benzylphosphonate.
The phosphonic acid based compound in this invention includes e.g. diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate and phenyl phenylphosphinate.
The phosphine oxide based compound in this invention includes e.g. diphenyl phosphine oxide, methyl diphenyl phosphine oxide and triphenyl phosphine oxide.
Among the phosphorus compounds described above, those compounds having an aromatic ring structure are preferably used for a significant effect of improving the catalytic activity.
As the phosphorus compound constituting the polycondensation catalyst of the invention, a compound represented by the following Formulae (1) to (3) is preferably used for a particularly significant effect of improving the catalytic activity.
P(═O)R 1 (OR 2 )(OR 3 ) (Formula 1)
P(═O)R 1 R 4 (OR 2 ) (Formula 2)
P(═O)R 1 R 5 R 6 (Formula 3)
(wherein R 1 , R 4 , R 5 and R 6 independently represent hydrogen, a C 1-50 hydrocarbon group, and a C 1-50 hydrocarbon group containing a hydroxyl group, a halogen group, an alkoxy group or an amino group, and R 2 and R 3 independently represent hydrogen and a C 1-10 hydrocarbon group, provided that the hydrocarbon group may contain an alicyclic structure such as cyclohexyl or an aromatic ring structure such as phenyl and naphthyl.)
The phosphorus compound constituting the polycondensation catalyst of the invention is particularly preferably a compound of Formulae (1) to (3) above wherein each of R 1 , R 4 , R 5 and R 6 is a group having an aromatic ring structure.
The phosphorus compound constituting the polycondensation catalyst of the invention includes e.g. dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenyl phenylphosphinate, diphenyl phosphine oxide, methyl diphenyl phosphine oxide and triphenyl phosphine oxide. Among these, dimethyl phenylphosphinate and diethyl benzylphosphinate are particularly preferable.
The amount of the phosphorus compound used in the invention is preferably 5×10 −7 to 0.01 mole, more preferably 1×10 −6 to 0.005 mole, relative to the number of moles of all constitutive units of carboxylic acid components such as dicarboxylic acid and polyfunctional carboxylic acid components in the resulting polyester.
For a further effect of improving the catalytic activity, it is preferable that one or more metal compounds selected from the group consisting of alkali metals or compounds thereof and alkaline earth metals or compounds thereof are coexistent with the polycondensation catalyst of this invention comprising the aluminum compound and the phosphorus compound.
The alkali metals or compounds thereof or the alkaline earth metal or compounds thereof in this invention are not particularly limited insofar as they are alkali metals or alkaline earth metals or one or more compounds selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba compounds; for example, these metal compounds include saturated aliphatic carboxylates such as formate, acetate, propionate, butyrate and oxalate, unsaturated aliphatic carboxylates such as acrylate and methacrylate, aromatic carboxylates such as benzoate, halogen-containing carboxylates such as trichloroacetate, hydroxycarbonates such as lactate, citrate and salicylate, inorganic acid salts such as carbonate, sulfate, nitrate, phosphate, phosphonate, hydrogen carbonate, hydrogen phosphate, hydrogen sulfate, sulfite, thiosulfate, hydrochloride, hydrobromate, chlorate and bromate, organic sulfonates such as 1-propane sulfonate, 1-pentane sulfonate and naphthalene sulfonate, organic sulfates such as lauryl sulfate, alkoxides such as methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy and t-butoxy, chelate compounds such as acetylacetonate, oxides and hydroxides, among which saturated aliphatic carboxylates are preferable and acetate is most preferable.
The amount of these alkali metal or compounds thereof or alkaline earth metals or compounds thereof used is preferably in the range of 1×10 −6 to 0.1 mole, more preferably in the range of 5×10 −6 to 0.05 mole, relative to the number of moles of all constitutive units of carboxylic acid components such as dicarboxylic acid and poly functional carboxylic acid components in the resulting polyester.
Production of polyester according to this invention can be conducted by a method known in the art. For example, PET can be produced by a method of esterifying terephthalic acid with ethylene glycol and subsequent polycondensation reaction, or a method of transesterification reaction between alkyl terephthalate such as dimethyl terephthalate and ethylene glycol and subsequent polycondensation reaction. Further, the polymerization apparatus may be a batch type or continuous reaction type.
The catalyst of this invention has a catalytic activity not only in polycondensation reaction but also in esterification reaction and transesterification reaction. The transesterification reaction between alkyl dicarboxylate such as dimethyl terephthalate and glycol such as ethylene glycol is conducted usually in the presence of a transesterification catalyst such as zinc, and in place of such catalyst or in coexistence of such catalyst, the catalyst of this invention can also be used. Further, the catalyst of this invention has a catalytic activity not only in melt state polymerization but also in solid state polymerization and solution polymerization.
The polycondensation catalyst of this invention is added desirably before polycondensation reaction, but the catalyst can also be added to the reaction system in an arbitrary stage before or during esterification reaction or transesterification reaction.
The polycondensation catalyst of this invention may be added in any form such as powder, neat, or a slurry or solution in a solvent such as ethylene glycol. Alternatively, a mixture prepared by previously mixing the aluminum compound with the phosphorus compound may be added, or the compounds comprising the catalyst may be separately added. Further, a mixture prepared by previously mixing the two or more compounds with alkali metals or compounds thereof or alkaline earth metals or compounds thereof may be added, or these compounds may be added separately.
For polymerization of polyester by use of the polymerization catalyst of the invention, an antimony compound and a germanium compound may be used in combination with the catalyst. In this case, the antimony compound is preferably added in an amount of 50 ppm or less (in terms of antimony atom) relative to the polyester obtained by polymerization. The antimony compound is added more preferably in an amount of 30 ppm or less. Addition of antimony in an amount of more than 50 ppm is not preferable because an antimony metal is precipitated resulting in the gray discoloration and formation of insoluble particles in the polyester. The germanium compound is added preferably in an amount of 20 ppm or less (in terms of germanium atom) in the polyester obtained by polymerization. The germanium compound is added more preferably in an amount of 10 ppm or less. Addition of germanium in an amount of more than 20 ppm is economically disadvantageous and thus not preferable.
The antimony compound used in this invention includes antimony trioxide, antimony pentaoxide, antimony acetate and antimony glycoxide, among which antimony trioxide is preferable. The germanium compound includes germanium dioxide and germanium tetrachloride, among which germanium dioxide is preferable.
With the polymerization catalyst of this invention, other polymerization catalysts such as titanium compound, tin compound and cobalt compound can be coexistent in such amount as not to deteriorate the thermal stability and color tone of polyester.
The polyester mentioned in the invention refers to polyester comprising at least one component selected from polyfunctional carboxylic acids including dicarboxylic acids and ester-forming derivatives thereof and at least one component selected from polyfunctional alcohols including glycols, to polyester comprising hydroxycarboxylic acids and ester-forming derivatives thereof, or to polyester comprising cyclic esters.
The dicarboxylic acids may include at least one of the following compound ;saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decane dicarboxylic acid, dodecane dicarboxylic acid, tetradecane dicarboxylic acid, hexadecane dicarboxylic acid, 1,3-cyclobutane dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 2,5-norbornane dicarboxylic acid and dimer acids or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid or ester-forming derivatives thereof, aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 5-(alkali metal) sulfoisophthalic acid, diphenic acid, 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4′-biphenyl dicarboxylic acid, 4,4′-biphenyl sulfone dicarboxylc acid, 4,4′-biphenyl ether dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p′-dicarboxylic acid, pamoic acid and anthracene dicarboxylic acid or ester-forming derivatives thereof And among these dicarboxylic acids, terephthalic acid and naphthalene dicarboxylic acid particularly 2,6-naphthalene dicarboxylic acid are preferable.
Polyfunctional carboxylic acids other than these dicarboxylic acids may include ethane tricarboxylic acid, propane tricarboxylic acid, butane tetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid and 3,4,3′,4′-biphenyl tetracarboxylic acid, as well as ester-forming derivatives thereof
The glycols may include at least one of the following compound ;aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5-pentane diol, neopentyl glycol, 1,6-hexane diol, 1,2-cyclohexane diol, 1,3-cyclohexane diol, 1,4-cyclohexane diol, 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexane dimethanol, 1,4-cyclohexane diethanol, 1,10-decamethylene glycol, 1,12-dodecane diol, polyethylene glycol, polytrimethylene, glycol, and polytetramethylene glycol, and aromatic glycols such as hydroquinone, 4,4′-dihydroxy bisphenol, 1,4-bis(β-hydroxyethoxy) benzene, 1,4-bis(β-hydroxyethoxyphenyl) sulfone, bis(p-hydroxyphenyl) ether, bis(p-hydroxyphenyl) sulfone, bis(p-hydroxyphenyl) methane, 1,2-bis(p-hydroxyphenyl) ethane, bisphenol A, bisphenol C, 2,5-naphthalene diol, as well as glycols having ethylene oxide added to the above glycols, and among these glycols, ethylene glycol and 1,4-butylene glycol are preferable.
Polyfunctional alcohols other than these glycols include trimethylol methane, trimethylol ethane, triemethylol propane, pentaerythritol, glycerol, hexane triol etc.
The hydroxycarboxylic acids may include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy) benzoic acid, 4-hydroxycyclohexane carboxylic acid, or ester-forming derivatives thereof The cyclic esters include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glucolide and lactide.
Further, the polyester of this invention can contain a known phosphorus compound as a copolymerizable component. The phosphorus compound is preferably a bifunctional phosphorus compound, and examples thereof include dimethyl phenylphosphonate, diphenyl phenylphosphonate, (2-carboxylethyl) methylphosphinic acid, (2-carboxylethyl) phenylphosphinic acid, methyl (2-methoxycarboxylethyl) phenylphosphinate, methyl (4-methoxycarbonylphenyl) phenylphosphinate, [2-(β-hydroxyethoxycarbonyl)ethyl]methylphosphinic acid ethylene glycol ester, (1,2-dicarboxyethyl) dimethyl phosphine oxide, 9,10-dihydro-10-oxa-(2,3-carboxypropyl)-10-phosphaphenanthrene-10-oxide, etc. By incorporating these phosphorus based compounds as copolymerizable components, the resulting polyester can improve flame retardancy etc.
The ester-forming derivatives of polyfunctional carboxylic acids or hydroxycarboxylic acids include alkyl esters, acid chlorides and acid anhydrides of such acids.
The polyester of this invention is preferably polyester whose main acid component is terephthalic acid or an ester-forming derivative thereof or naphthalene dicarboxylic acid or an ester-forming derivative thereof and whose main glycol component is alkylene glycol. The polyester whose main acid component is terephthalic acid or an ester-forming derivative thereof or naphthalene dicarboxylic acid or an ester-forming derivative thereof is polyester wherein the total of terephthalic acid or an ester-forming derivative thereof or naphthalene dicarboxylic acid or an ester-forming derivative thereof is preferably 70 mole % or more, more preferably 80 mole % or more, and most preferably 90 mole % or more, to the total acid components. The polyester whose main glycol component is alkylene glycol is polyester wherein the total of alkylene glycol is preferably 70 mole % or more, more preferably 80 mole % or more, and most preferably 90 mole % or more, to the total glycol components. As used herein, the alkylene glycol may contain a substituent group or an alicyclic structure in the molecular chain thereof
The naphthalene dicarboxylic acid or ester-forming derivatives thereof used in this invention are preferably 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid or ester-forming derivatives thereof.
The alkylene glycol used in this invention includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5-pentane diol, neopentyl glycol, 1,6-hexane diol, 1,2-cyclohexane diol, 1,3-cyclohexane diol, 1,4-cyclohexane diol, 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexane dimethanol, 1,4-cyclohexane diethanol, 1,10-decamethylene glycol, and 1,12-dodecane diol. These may be used in combination thereof.
The polyester of this invention can, as acid components other than terephthalic acid or an ester-forming derivative thereof and naphthalene dicarboxylic acid or an ester-forming derivative thereof, contain saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decane dicarboxylic acid, dodecane dicarboxylic acid, tetradecane dicarboxylic acid, hexadecane dicarboxylic acid, 1,3-cyclobutane dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 2,5-norbomane dicarboxylic acid and dimer acids or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid or ester-forming derivatives thereof, aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, 5-(alkali metal) sulfoisophthalic acid, diphenic acid, 4,4′-biphenyl dicarboxylic acid, 4,4′-biphenyl sulfone dicarboxylic acid, 4,4′-biphenyl ether dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p′-dicarboxylic acid, pamoic acid and anthracene dicarboxylic acid or ester-forming derivatives thereof, and polyfunctional carboxylic acids such as ethane tricarboxylic acid, propane tricarboxylic acid, butane tetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid and 3,4,3′,4′-biphenyl tetracarboxylic acid or ester-forming derivatives thereof The polyester of this invention can also contain hydroxycarboxylic acids such as lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy) benzoic acid and 4-hydroxycyclohexane carboxylic acid or ester-forming derivatives thereof. Further, the polyester can also contain cyclic esters such as ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide and lactide.
The polyester of the invention can, as glycol components other than alkylene glycol, contain aliphatic glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, polytrimethylene glycol and polytetramethylene glycol, aromatic glycols such as hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy) benzene, 1,4-bis(β-hydroxyethoxyphenyl) sulfone, bis(p-hydroxyphenyl) ether, bis(p-hydroxyphenyl) sulfone, bis(p-hydroxyphenyl) methane, 1,2-bis(p-hydroxyphenyl) ethane, bisphenol A, bisphenol C, 2,5-naphthalene diol and glycols having ethylene oxide added to the above glycols, and polyfunctional alcohols such as trimethylol methane, trimethylol ethane, trimethylol propane, pentaerythritol, glycerol and hexane triol as copolymerizable components.
The polyester of this invention can contain a known phosphorus based compound as a copolymerizable component. The phosphorus based compound is preferably a bifunctional phosphorus based compound, and examples thereof include dimethyl phenylphosphonate, diphenyl phenylphosphonate, (2-carboxylethyl) methylphosphinic acid, (2-carboxylethyl) phenylphosphinic acid, methyl (2-methoxycarboxylethyl) phenylphosphinate, methyl (4-methoxycarbonylphenyl) phenylphosphinate, [2-(β-hydroxyethoxycarbonyl)ethyl]methylphosphinate ethylene glycol, (1,2-dicarboxyethyl) dimethyl phosphine oxide, 9,10-dihydro-10-oxa-(2,3-carboxypropyl)-10-phosphaphenanthrene-10-oxide, etc. By incorporating these phosphorus based compounds as copolymerizable components, the resulting polyester can improve flame retardancy etc.
The polyester of the invention is preferably polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, poly(1,4-cyclohexanedimethyleneterephthalate), polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate and a copolymer thereof, among which polyethylene terephthalate and a copolymer thereof are particularly preferable.
The polyester of this invention can contain antioxidants such as phenolic or aromatic amines, and by containing one or more of these antioxidants, the resultant polyester can improve e.g. thermal stability. The phenolic antioxidants include tetrakis-[methyl-3-(3′,5′-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 4,4′-butylidene bis-(3-methyl-6-tert-butylphenol), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene.
The polyester of this invention may contain other arbitrary polymers, stabilizers, antioxidants, antistatic agents, antifoaming agents, dyeing assistants, dyes, pigments, delusterants, optical brighteners and other additives.
EXAMPLES
Hereinafter, this invention is described in more detail by reference to the Examples, which however are not intended to limit this invention. The intrinsic viscosity (IV) of polyester in each of the Examples and Comparative Examples was measured at a temperature of 30° C. in a 6/4 mixed solvent (ratio by weight) of phenol/1,1,2,2-tetrachloroethane.
Example 1
As the catalyst, 3 g/l aluminum chloride in ethylene glycol was added, in an amount of 0.015 mole % in terms of aluminum relative to the acid component in polyester, to bis(2-hydroxyethyl) terephthalate, and then dimethyl phenylphosphonate was added in an amount of 0.02 mole % relative to the acid component in polyester, and the mixture was stirred at 245° C. for 10 minutes at atmospheric pressure. Then, the mixture was heated over 50 minutes to 275° C., during which the pressure in the reaction system was gradually reduced to 0.1 mmHg, and further polycondensation reaction was conducted for 3 hours at the same temperature and at the same pressure. The intrinsic viscosity of the resulting polymer is shown in Table 1.
Examples 2 to 7 and Comparative Examples 1 to 2
Polyester was polymerized in the same manner as in Example 1 except that the catalyst was changed. The intrinsic viscosity of the resulting polymer is shown in Table 1.
TABLE 1
Catalyst
Amount
IV(dlg −1 )
Example 1
Aluminum chloride
0.015 mol %
0.55
Dimethyl
0.02 mol %
phenylphosphonate
Example 2
Aluminum acetate
0.03 mol %
0.57
Diethyl
0.01 mol %
benzylphosphonate
Example 3
Aluminum hydroxide
0.05 mol %
chloride
Diphenylphosphinic
0.07 mol %
0.62
acid
Example 4
Aluminum
0.01 mol %
0.6
acetylacetonate
Dimethyl
0.01 mol %
phenylphosphonate
Example 5
Aluminum hydroxide
0.065 mol %
0.59
Diphenyl phosphine
0.03 mol %
oxide
Example 6
Aluminum acetate
0.01 mol %
0.6
Diethyl
0.005 mol %
benzylphosphonate
Lithium acetate
0.025 mol %
Example 7
Aluminum chloride
0.005 mol %
0.62
Dimethyl
0.01 mol %
phenylphosphonate
Sodium acetate
0.05 mol %
0.31
Comparative
Aluminum chloride
0.015 mol %
0.27
Example 1
Comparative
Dimethyl
0.02 mol %
Example 2
phenylphosphonate
According to this invention, there is provided a novel polycondensation catalyst other than antimony compounds as well as polyester produced by using the same. The polyester of this invention can be applied to fibers for clothes, fibers for industrial materials, various films, sheets and molded articles such as bottles and engineering plastics, as well as coatings and adhesives.
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The present invention provides processes for producing polyester. In one of the embodiments, the invention provides a process for producing polyester, comprising adding a catalyst in a polycondensation reaction, esterification reaction or transesterification reaction between components comprising at least a polyfunctional alcohol and at least a polyfunctional carboxylic acid or ester-forming derivative of a polyfunctional carboxylic acid to produce the polyester; and obtaining the polyester, wherein the polymerization catalyst comprises an aluminum substance and a phosphorus compound, wherein the aluminum substance is selected from the group consisting of aluminum hydroxide and aluminum alkoxides, and wherein the phosphorus compound has an aromatic ring structure.
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RELATED APPLICATIONS
This is a continuation of co-pending application heretofore filed by the same inventor on Sept. 23, 1970 under Ser. No. 74,688, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates generally to the field of bicycles and more particularly to a bicycle having a pivotably mounted, steerable rear wheel with associated pedal-type propelling mechanism.
2. Description of Prior Art
Various forms of wheeled, cycle type, operator propelled vehicles have heretofore become known, the bicycle undoubtedly being the most common. My invention provides a vehicle of this type wherein a main frame upon which the rider sits pivotably mounts in its rearward part a steerable rear wheel frame carrying the rear wheel and associated pedal-type propelling mechanism.
My device is distinguishable from a one wheeled vehicle or unicycle, aside from the number of wheels, in that the frame upon which the rider sits on the unicycle does not pivot about a vertical axis perpendicular to the axis of rotation of the wheel of the vehicle. It is further readily distinguishable from the three wheeled or tricycle type vehicle, again aside from wheel number, in that it is not propelled by pedal mechanism associated with the front wheel. Both unicycles and tricycles by reason of their peculiar wheel structure require different balance and operating techniques of steerage, propulsion and the like than the two-wheeled bicycle, and are threby readily distinguishable from my invention in both structure and function.
Heretofore two wheeled bicycles with pivotably mounted rear wheels have become known. One form that provided pedal mechanism associated with the front wheel may be distinguishable from the instant invention in that this driving linkage pulls the vehicle rather than pushing it as in my bicycle that is operated by linkage associated with the rear wheel. Another form of such a bicycle provides locomotion by a hand operated leverage system associated with the front wheel to again be distinguishable on the basis of structure.
Other two wheeled bicycles that have provided pivotable mounting of both front and rear wheels, have provided some mechanical linkage between the two wheels to require each to move with its plane of rotation parallel to that of the other. Such vehicles have generally provided some parallelogram type linkage of levers or connecting rods crossed in "X" fashion to link the wheels to require parallel motion for more simple steerage and stability. My invention is distinguishable from these devices in that its front and rear wheels are independently pivotable without mechanical linkage therebetween and with neither wheel moving in any related fashion to the other except as directed by an operator.
My invention is further distinguishable from the prior art in allowing releasable biasing or locking of the pivotable linkage of the rear wheel frame to the principal frame to provide the function of an ordinary bicycle if desired.
SUMMARY OF INVENTION
My invention provides a two wheel, operator propelled vehicle comprising generally a main frame pivotably mounting in its forward portion a steerable front wheel structure and pivotably mounting in its rearward portion a pivotable back wheel structure. The main frame carries an adjustable seat part to support an operator in seated position for pedaling. The forward wheel structure provides handle bars to aid manual steering. The back wheel structure has associated pedal-type propelling mechanism irrotatably carried relative the back wheel structure to allow propulsion and steering. A spring releasably extends between the pivotably back wheel structure and the main frame to bias the back wheel to a straight course and releasable catch means are provided to lock the rear wheel structure's motion relative the main frame. Either front or rear wheel, however, may pivot completely independently of the other and the angular orientation of either relative the frame may be controlled by an operator.
In providing such a mechanism it is:
A principal object of my invention to create a bicycle having a pivotably mounted rear wheel frame that may pivot about a substantially vertical axis perpendicularly to the axis of wheel rotation, independently of the front wheel.
A further object of my invention to provide such a device that has pedal-type propelling mechanism, associated with the rear wheel, that may be manipulated by the operator to direct the angular orientation of the rear wheel.
A further object of my invention to provide such a vehicle with both mechanical biasing and catching means communicating between the rear wheel frame and the principal frame, to stabilize linear motion of the vehicle and allow its operation as a traditional bicycle.
A still further object of my invention to provide such a vehicle that is of new and novel design, of rugged and durable nature, of simple and economic manufacture, and otherwise well adapted to the uses and purposes for which it is intended.
Other and further objects of my invention will appear from the following specification and accompanying drawings which form a part thereof. In carrying out the objects of my invention, however, it is to be understood that its essential features are susceptible of change in design and structural arrangement, with only one preferred and practical embodiment being illustrated in the accompanying drawings as required.
BRIEF DESCRIPTION OF DRAWINGS
In the accompanying drawings which form a part of this specification and wherein like numbers of reference refer to similar parts throughout.
FIG. 1 is an orthographic side view of my bicycle showing its parts, their configuration and relationship.
FIG. 2 is an enlarged, partial, cross sectional view of the rear journal of my invention, taken on the line 2--2 of FIG. 1, looking rearward in the direction indicated by the arrows thereon.
FIG. 3 is a partial, orthographic top view taken on a projection plane such as that illustrated by the trace 3--3 on FIG. 1 in the direction indicated by the arrows thereon, with on positional variation shown in dotted outline.
FIG. 4 is a partially cutaway view of a latching mechanism that may be used with my invention to fixedly position the rear wheel frame.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the drawings in more detail and particularly to that of FIG. 1, it will there be seen that my invention comprises generally a two wheeled vehicle having main frame 10 pivotably mounting front wheel structure 11 in its forwardmost part and back wheel structure 12 with associated propelling-steering mechanism 13 in its rearwardmost part.
Main frame 10 comprises elongate, vertically spaced upper beam 14 and lower beam 15 structurally communicating between forward journal 16 and rearward journal 17, each disposed at diverging angles from a medial vertical line to appropriately position the wheel structure for added stability. Each of the journals 16, 17 is of similar nature; as illustrated in FIG. 2, cylindrical, medial journal body 18 carries upper thrust bearing 19 and lower thrust bearing 20 in its end parts by a press fit or other mechanical attachment. The shaft of the wheel structure then fits within the medial cylindrical area of the journal between the bearings to provide a pivotable mounting. This type of journal is known in the bicycle art.
Seat 21, carried for vertically adjustable positioning in the rearward part of the frame 10, in its forward part pivotably communicates with slideably adjustable frame clamp 22 and in its rearward part by bolt-nut combinations 23 to paired, opposed rear seat supports 24. The rear seat supports are mounted on paired opposed studs 25 threadedly engaged in nuts 26 structurally carried by cylindrical journal body 18 in medial positions on the lateral parts. With this arrangement of parts and an arcuate, upwardly curved upper beam 14, the vertical position of seat 21 may be adjusted by moving forward clamp 22 forwardly or rearwardly along the beam 14. This type of seat again is known in the bicycle arts.
Front wheel structure 11 provides front wheel fork 27 depending forwardly and downwardly to rotatably mount front wheel 28 in its end part on horizontal, releasably positionable axle 29. Forward fender 30 is mounted in fork 27 at appropriate position immediately above the front wheel. The upper portion of fork 27 is configured as a cylinder to pivotably mount within forward journal 16 with upper and lower cones 55 immediately outwardly adjacent the thrust bearings. Handle bars 31 are adjustably mounted in handle bar bracket 32 carried in the upper part of depending handle bar brackets arm 33 pivotably adjustably carried by the upper part of front wheel fork 27 so that the vertical angular relationship of handle bars 31 may be adjusted by bracket 32 and the horizontal angular relationship between the handle bars and front wheel 38 may be adjusted in the communication with front wheel fork, all to provide the traditional, steerable, front wheel structure known in the bicycle art, with handle bars irrotatable relative the front wheel and both rotatable relative principal frame 10.
Back wheel structure 12 provides, "Y" shaped back wheel fork 34, similar in structure to the front wheel fork, having uppermost cylindrical body 35 pivotably mounted within the internal void of rearward journal 17 between upper and lower thrust bearing 19, 20. The uppermost portion of body 35 provides thread 36 to engage upper cone 37 and the portion of body 35 immediately below lower thrust bearing 20 provides lower cone 38 to maintain the structure in the bearing. Lock washer 39 is provided between the upper surface of upper cone 37 and cap nut 63 to aid in maintaining the elements in position.
The lowermost portion of each arm of back wheel fork 34 is provided with opposed cooperating channels 40 to receive threaded bicycle axle 41 rotatably mounting rear wheel 42. Rear fender 43 is mounted between the back wheel fork elements immediately above the rear wheel in appropriate position. With this linkage it is seen that back wheel structure 12 may pivot or rotate relative main frame 10.
Propelling mechanism 13 is carried by the pedal frame formed by principal chord 45 and angle support 44, each structurally communicating in their rearward portions with back wheel fork 34 and in the medial part of the principal chord with each other. The forward portion of principal chord 45 pivotably mounts the axle of ordinary pedal 46. This pedal in its medial axle part irrotatably carries driving cog 47 which communicates by endless roller chain 48 to wheel cog 49 supported upon rear wheel axle 41. An ordinary bicycle coaster brake communicates between wheel cog 49 and rear wheel 42 to provide a power train from the pedal to the rear wheel. Chain guard 50 extends over the upper part of driving cog 47 and chain 48 to protect the operator and his clothing therefrom. This propelling mechanism again is not new per se and in general is known in the bicycle arts, except for its particular mounting. It is to be noted in this regard that the propelling mechanism is supported entirely upon back wheel structure 12 and free of the principal frame to provide a foot operated steering lever for the back wheel structure.
In some instances linear stability of motion, or at least a tendancy toward such stability, may be desired in my vehicle. If so, mechanical biasing 51 may be provided between back wheel structure 12 and main frame 10. The biasing structure illustrated comprises extension spring 52 communicating from hole 53 in lower beam 15 rearwardly and downwardly to fastening bracket 54 structurally carried by the rear wheel fork structure.
Similarly it may be desirable at times to releasably fix the rear wheel structure relative the principal frame to provide an operation of my vehicle of the same nature as that of an ordinary bicycle. If so, this may be accomplished by catching means 56 providing pin latch 57 slideably mounted in bracket 58 and adjustably positionable therein by manual positioning of pin handle 59 within one of the bracket notches 60. The rearward part of pin 57, its rearward position, fits within cooperating holes 61, 62 in bearing body 18 and back wheel fork body 35 respectively to lock the pivotable motion therebetween.
Having thusly described the structure of my invention its operation may be understood.
Firstly a bicycle is constructed according to the foregoing specification. To use it a rider first adjusts the vertical positioning of seat 21 for comfortable accommodation and then seats himself thereupon astraddle main frame 10 with feet upon opposed pedals 46 and hands upon handle bars 31. In this position he then operates the pedals to rotate driving cog 47 and thusly rear wheel 42 to cause motion in the vehicle. The direction of motion may be regulated by changing the angular orientation of either front wheel 28 or rear wheel 42 relative main frame 10 or relative to each other.
The angular positioning of the front wheel structure 11 relative the principal frame is determined by manual manipulation of handle bars 31. The angular position of back wheel structure 12 is regulated by pediatric manipulation of pedal structure 13.
With completely independent angular positioning of both front and rear wheels the motion of the vehicle may be quite erratic to such degree as desired by the operator. If it be desired to limit this motion, especially during learning endeavors with the vehicle, biasing device 51 such as the mechanical spring illustrated may be used. If more erratic activity be desired for novelty type riding or as an amusement, the mechanical biasing may be done away with. If it be desired to use the vehicle as an ordinary bicycle, catching means 56 may be engaged in the rear wheel pivot to fixedly position it. Obviously other types of mechanical biasing and locking might accomplish the same purpose as the specific embodiments illustrated.
It is to be particularly noted that both front and rear wheels may pivot entirely independently of each other and each in fact is rotatable so that either may occupy any rotary position at any time; this mechanical configuration may give rise to any type of motion possible with a two wheeled vehicle having a rigid frame.
It is further to be noted that the angular position of the rear wheel structure relative the main frame may be controlled by pediatric manipulation during the pedaling operation or at other times. Obviously some skill must be attained to accomplish this steerage but with practice it is quite possible.
The foregoing description of my invention is necessarily of a detailed nature so that a specific embodiment of it might be set forth as required but it is to be understood that various modifications of detail, rearrangement and multiplication of parts may be resorted to without departing from its spirit, essence, or scope.
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A two wheeled, rider propelled vehicle having both wheels pivotably mounted upon a medial principal frame. The pivotable rear wheel frame supports pedal mechanism propelling the rear wheel and may be steered by the feet of the user. Mechanical biasing means communicate between the pivotable rear wheel frame and main frame to bias motion and a latching mechanism allows fixed positioning of the two members. A vertically adjustable seat is fixedly carried by the principal frame and the forward portion of the vehicle provides a traditional manually steerable, pivotably mounted front wheel frame.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a new sub-denier spunbonded nonwoven web product produced by a unique spunbond apparatus and its unique operating process for the continuous production of thermoplastic synthetic resin filaments at unusually high filament speeds. More particularly the invention relates to the production of such nonwoven webs by this spunbond apparatus utilizing extremely high fiber speeds, generally of the order of 80 m/sec and more typically exceeding 100 m/sec. resulting in fibers on the order of 1.0 denier and less. In another important aspect, the invention relates to a nonwoven fabric possessing a more uniformly random web structure with sub-denier fibers created by the inventive apparatus and method. This web structure results in a narrower ratio of machine direction to cross direction tensile properties in addition to significantly improved cover and greater opacity.
[0003] 2. Prior Art
[0004] It is well known to produce nonwoven webs from thermoplastic materials by extruding the thermoplastic material through a spinneret and drawing the extruded material into filaments by eduction to form a random web on a collecting surface. U.S. Pat. No. 3,802,817 to Matsuki et al describes a full width eductor device and method which requires high pre—ssures, however it is limited to lower speeds for practical operation. U.S. Pat. No. 4,064,605 to Akiyama et al similarly describes apparatus employing high speed air jet drafting with the same inherent limitations. U.S. Pat. No. 5,292,239 to Zeldin et al discloses a device that significantly reduces turbulence in the fluid flow in order to uniformly and consistently apply the drawing force to the filaments, which results in a uniform and predictable draw of the filaments. This system limits the magnitude of attenuation because of insufficient draw forces due to the extremely shallow jet angle. U.S. Pat. No. 5,814,349 to Geus et al discloses a device which combines quench fluid flow with below the belt suction. However, this arrangement requires a decoupling device in order to prevent skein forming deceleration which negates the original advantages of the U.S. Pat. No. 5,032,329 to Reifenhauser.
[0005] Polypropylene is the only thermoplastic resin that is commonly utilized in conventional air drawn spunbond processes. It is important to note that due to the limitations of existing spunbond spinning systems it is virtually impossible to process resin entities in equipment designed for polypropylene where flow and spinning characteristics deviate significantly from polypropylene.
[0006] As a first step, the resin is melted and extruded through a spinneret to form a vertically oriented cascade of downwardly advancing molten fibers. The filaments are fluid cooled to quench and uniformly cool the filament curtains for optimum drawing and development of the desired high crystallinity which provides the goal of high fiber strength. A fiber drawing system having a fluid draw jet-slot, into which a controlled volume of high velocity fluid is introduced, draws additional fluid into the upper open end of the drawing slot and creates a rapidly moving downstream of fluid within the slot. This fluid stream creates a contiguous drawing force on the filaments, causing them to be attenuated. After the filaments are attenuated they exit the bottom of the slot where they are deposited on a moving conveyor belt to form a continuous web of the filaments. The filaments of the web are then joined to each other through conventional calendering and point bonding techniques.
[0007] Forming filaments in the well known conventional spunbond systems results typically in filaments of 2.5 denier to 12 denier and higher. Using conventional methods, the molten filaments leaving the spinneret typically are immediately cooled at their surfaces to ambient temperature and then subjected to the typical drawing system. This conventional method and apparatus produce adequate non-woven fabrics however their properties, especially tensile strength, high machine direction to cross direction strength ratio, non-chemically enhanced hydrophobicity, drape, softness and opacity are poor.
[0008] When conventional spunbond systems attempt to make sub-denier fiber the resin output per hole drops precipitously reducing spunbond fabric production to less than half of the production when forming spunbond of typical denier range.
[0009] The instant invention through the use of a unique new apparatus and process, provides a greatly improved spunbond fabric consisting of a narrow range of low denier filaments which improves all of the aforementioned properties.
[0010] The low-denier filaments with their smaller diameter produces more surface area and more length per unit weight, reduces light transmission and improves light dispersion (greater opacity) and softness (lower unit fiber deflection forces). Using the instant invention spunbonded fabrics can be made from a wide range of resins, in addition to polypropylene, such as polyethylene, polyester, polyamides, polycarbonate, polyphenylene sulfide, liquid crystal polymers, fluropolymers, polysulfone and their copolymers as well as other extrudable synthetic resins. Providing narrow ranges of filament sizes from 0.1 denier to 1.0 denier with a wide range of polymers is extremely desirable because of their improved performance properties as indicated above. A further process benefit of the instant invention is that resin throughput per hole per minute is not reduced below existing commercial rates.
[0011] Examples of end uses for the instant invention are filtration materials, diaper covers and medical and personal hygiene products requiring liquid and particulate barriers that are breathable and provide good vapor transport with significant air permeability. Because of the low denier the spunbond fabrics produced by the instant invention have physical and performance properties comparable to SMS (Spunbond-Meltblown-Spunbond), SMMS (Spunbond-Meltblown-Meltblown-Spunbond) and SM (Spunbond-Meltblown) fabrics. This is an important result since it suggests that a single die head or beam can produce a material which now requires from two to four die beams.
[0012] Prior conventional spunbond art is almost completely concerned with the use of polypropylene. An important limitation of prior art is the inadequacy of conventional spunbond systems to extrude and highly draw common resins such as polyester, polyethylene or more unusual resins such as polyamides, polycarbonate, polysulfone and polytetrafluoroethylene.
[0013] The instant invention teaches apparatus and processes that are designed with intrinsic accommodations to extrude and draw fibers with an extreme range of extrusion temperatures, wide variations in glass transition temperatures, wide ranges of melt viscosities and other variable resin properties important to filament extrusion, forming, quenching and drawing, thereby widening the application of the spunbond arts.
OBJECTS OF THE INVENTION
[0014] It is the principal object of the present invention to provide an improved system for the production of spunbonded nonwoven webs of thermoplastic synthetic resin filament which allows:
[0015] 1. significant increase in filament velocity and attenuation over a wide range of filament diameters.
[0016] 2. significant decrease in fiber denier or diameter at lower operating costs without sacrificing mass through-put.
[0017] 3. capability of spunbonding a wide variety of resins using one apparatus having a wide degree of adjustment in the extrusion, forming, quenching, drawing and laydown operations.
[0018] 4. stronger fibers through improved crystallization kinetics based on improved attenuation and quench control.
[0019] 5. higher nonwoven fabric opacity and cover.
[0020] 6. increased fiber and nonwoven fabric uniformity (narrower filament diameter range).
[0021] 7. significant increase in collector speeds with resultant higher mass throughput.
[0022] 8. production of webs with filament deniers of less than 1.0.
[0023] 9. production of light weight webs at collector speeds in excess of 600 meters per minute.
[0024] 10. production of nonwoven material at mass rates of greater than 400 to 600 kg/hr/meter of die width.
[0025] 11. Filament spinning speed of greater than or equal to 7000 meters/minute.
[0026] More specifically, it is an object of the invention to improve a spun-bond apparatus so that the throughput of the synthetic resin filament is increased and the production rate enhanced without encountering drawbacks typically found in spunbond apparatus such as excessive energy consumption and poor web uniformity.
[0027] Other important objects of the invention are to provide:
[0028] 1. an improved method of operating a spunbond apparatus to eliminate drawbacks thereof by increasing the degree of attenuation while decreasing the filament denier at relatively low energy cost with a minimum of process complexity.
[0029] 2. an improved method of feeding precise amounts of resin to each orifice in the spinnerets using multiple feeding mechanisms.
[0030] 3. an improved filament extrusion die with the capability of containing a greater number of extrusion orifices per meter of die width and length. an improved apparatus for the purposes described which allows the operating conditions within the apparatus to be varied in a sufficiently wide range of relationships to accommodate a large variety of resin materials and for the production of a wide range of products without the limitations characterizing earlier and present spunbond production systems.
[0031] 4. improved quenching performance and uniformity by precise control of fluid temperature and velocity in a plurality of descending zones of the quench fluid system.
[0032] 5. an improved apparatus including a fluid inlet infuser, a draw jet-slot, a draw jet-nozzle, a venturis, and a outlet fluid diffuser which are independently adjustable to provide optimum process control over a broad range of resins.
[0033] 6. an improved apparatus and process which increases the drag force on fibers by inducing a controlled sinusoidal fiber track which permits the fiber velocity to be increased by increasing the area of fiber exposed to the drafting fluid drag forces thus significantly reducing the filament denier and decreasing energy requirements.
[0034] 7. an improved apparatus and process which provides controls induction of fluid into the draw jet slot extension below the venturi to induce mini-vortices at the walls and provide a turbulent boundary layer.
[0035] 8. improved uniformity of filament laydown by controlled turbulent separation of the fiber cascade at the entrance to the lower adjustable fluid volume control diffuser.
[0036] 9. an improved method of making nonwoven webs of synthetic resin filaments whereby drawbacks of earlier and present conventional spunbond systems, especially limitations on draw force, fiber velocity, fiber formation and web collector speed are eliminated.
[0037] All of the aforementioned process and product improvements are an integral result of the system which is presented below.
SUMMARY OF THE INVENTION
[0038] An apparatus for the production of sub-denier spunbonded nonwoven fabrics has, according to the invention, a resin extrusion device, a unique multi-head metering system for micro-metering resin to micro-distributors in the spinnerets, a spinneret die head with dual front and back perforated spinning sections, separated by a buffer section or quench fluid extraction zone having a lower density of perforations and in some embodiments no perforations, wherein the buffer section allows full and uniform penetration of quench fluid, for extruding a multiplicity of continuous thermoplastic strands that then descend through a two sided, multilevel quench system and thence through a fluid volume control infuser system, which meters quench fluid into or, if required by the process conditions, out of the filament drawing system.
[0039] The quench fluid is supplied from a blower through one or more heat exchangers into a controlled three level manifold which permits flow rate and temperatures to be controlled independently into each segment of the quench cabinet.
[0040] The dual spinning sections with the unique buffer zone or quench fluid extraction zone located between the two outside spinning sections is a very important part of the instant invention because it permits the use of more spinneret orifices per meter of width than can be accomplished in conventional systems. This is accomplished by using a high density of orifices in the two outside spinning sections and a central fluid buffer zone or quench fluid extraction zone located between the two outside spinning sections. Experimentation with the design of the buffer zone indicated that it could also be used for the production of additional filaments without creating a disturbance in the filaments at the point of the two streams' impingement. We further found when the filament density, or orifice density, was about eighty percent or less of the filament density of the dual spinning sections that impingement of the opposing fluid streams in the buffer zone was not an issue. Consequently the central buffer zone may contain a reduced density of perforations, or in some embodiments, a zero density of perforations.
[0041] This overcomes the necessity to significantly reduce resin flow per hole per minute which is the main drawback in producing low or sub-denier fibers at commercially acceptable rates. The end result of the flow reduction is that low denier fiber production is always reduced far below commercial expectations. Furthermore, inadequate control of the quench process results in ineffective drawing with resultant non-uniform and weak fibers.
[0042] The bilateral nature of the split array orifice spinnerets with an independently controlled bilateral quench system also permits the use of two different but compatible resins, one on each side, or a differentially quenched bicomponent filament.
[0043] The filament cascade is automatically guided into the filament drawing system by the fluid volume control infuser system which depends from the lower surface of the quench assembly and is extensibly attached to the draw jet assembly. The purpose of the fluid volume control infuser system is to conserve energy by using a portion of the quench fluid as part of the drawing fluid and simultaneously minimizing turbulence at the entrance to the draw slot thus providing a uniform cascade of filaments to the drawing step. This arrangement provides a self feeding action for the descending cascade of filaments and is extremely important from an operational standpoint.
[0044] The fluid volume control infuser system consists of two perforated plates oppositely situated and variable, as to angle, open area and vertical length, each containing a multiplicity of uniquely shaped and oriented perforations to permit two-way fluid flow. Further, the open area of the multiplicity of fluid holes is controllable as to area by use of a slide gate or similar fluid volume control means. The holes or amount of open area controls the amount and pressure of fluid in the infuser and controls turbulence but allows the fluid to be automatically bled off or entrained.
[0045] When quench fluid, descending from buffer zone, is drawn into the fluid volume control system infuser by its downward velocity and the suction developed at the inlet of the draw jet slot opening by the draw jet flow an over-pressure condition may occur which may cause turbulence at the slot inlet. The combination of the fluid scoop shape and the open area of the infuser plates permits the automatic shedding of excess fluid and the balancing of pressures as the fluid and filament velocities increase into the slot. The variable area permits the specific adjustment for different resin species where the quench fluid may be very high or low in volume and velocity. The major axis length of the perforated holes ranges from 10 millimeters to 100 millimeters. Each row may have different sized holes. The fluid scoop portion of the hole is elevated above the outer surface of the infuser plate.
[0046] The infuser plates have a sliding means in their lower portion which permits the distance between the lower edge of the quench system and the upper surface of the draw jet assembly to be adjusted to required process conditions for different resin species.
[0047] The filament drawing system consists of a draw jet assembly that contains a variable width draw jet-slot and variable width draw jet-nozzle. The assembly consists of a right and a left hand vertical halves. The right and left hand vertical halves are moveable horizontally in relation to each other. The entire draw jet assembly is moveable vertically in order to optimize the distance between the draw jet-slot and the emerging filaments at the spinnerets.
[0048] The space between the left and right vertical halves defines the variable width slot used to vary drawing velocity. The upper surface of both the right and left hand halves of the assembly contains an adjustable nozzle plate that is moveable horizontally in relation to the slot wall and serves to define the variable width draw jet-nozzle outlet passage and thus adjusts the draw jet fluid velocity. The angle formed by the centerline of the primary jet-nozzle and the centerline of the draw jet-slot ranges from 2 degrees to 45 degrees. The slot extends vertically to the draw jet extension and horizontally the width of the spinneret head. The draw jet-nozzles formed by the adjustable nozzle plate and the upper edge of the vertical halves provide motive fluid for the drawing process, extend the full horizontal width of the jet-slot.
[0049] Experimentation showed that when the two horizontally opposed and adjustable draw jet-nozzles are offset vertically by a centerline distance of from 1 millimeter to 50 millimeters the draw force is still very high but, surprisingly, a vertical sinusoidal oscillation is created in the descending cascade of filaments. The filaments produced with this innovation were significantly finer than when the jet-nozzles were directly opposed and not offset. The oscillation produces a higher filament drag coefficient and thus increase the energy transfer coefficient between the filaments and the draw jet fluid stream thereby increasing the fiber attenuation.
[0050] Further experimentation showed that this oscillation could also be produced by several alternative methods. When a second set of adjustable gap jet-nozzles are located in the slot wall on each side of the left and right hand assembly halves and below the primary draw jet-nozzles, and when these secondary jet-nozzles are directly opposed and not offset, and are provided with a system that emits pulses of fluid at a fixed angle across the slot alternately from each side these secondary jet-nozzles also create a small sinusoidal oscillation in the filament cascade which provides a larger drag area for the motive fluid to impact and to accelerate the individual filaments. The angle formed by the center line of the secondary jet-nozzles and the centerline of the draw jet-slot ranges from 2 degrees to 45 degrees. The increased drag coefficient also provides a more efficient transfer of energy to the filaments. The secondary jet-nozzle may also suck fluid out of the draw jet-slot in the same alternating pulsation mode. It was also discovered that off-set pulsating jets also produced the required oscillations.
[0051] Experimentation has also shown that the filaments may also be oscillated by a constant or intermittent flow from only one side. It was eventually discovered that the secondary jet-nozzle system worked best when they were offset and the flow was constant from each side. It was discovered that in the primary jet plus secondary jet configuration the additional fluid flow together with improved drag factor from the oscillation effect added an unexpectedly high velocity increment to the filament curtain which resulted in remarkably low fiber diameters which were in the 0.5 denier to 1.2 denier range depending on the system configuration. Adjustable gap secondary draw jet-nozzles were also evaluated and determined to provide even better control of denier. Both the primary and secondary jets are preceded by a full die width pressure equalization and distribution system.
[0052] Below and attached to the lower half of the draw jet assembly is a supplemental acceleration device or draw jet slot extension, which has a horizontally adjustable slot similar to the draw jet assembly slot but which is also vertically adjustable and contains two in-line or tandem venturis or other fluid acceleration devices to maintain fiber tension and draw force through the lower end of the draw system. Alternative fluid acceleration devices such as a NASA profile convergent-divergent nozzle or other fluid acceleration means can also be used.
[0053] The draw jet extension has an adjustable slot and venturi width to control draw velocity and maintain constant tension on the filament cascade. The draw jet extension's distance above the foraminous collector belt is also adjustable.
[0054] Below each venturi is an additional set of adjustable inlet jets on both sides which may be used to suck in ambient fluid thereby creating a series of micro-vortices in the wall boundary layer. This creates a turbulence at the wall between the first venturi and the second venturi and after the second venturi prior to the exit into the fluid volume control diffuser system.
[0055] The fluid volume control diffuser system consists of two perforated plates oppositely situated and variable, as to angle, open area and vertical length. The major axis length of the perforated holes ranges from 10 millimeters to 100 millimeters. Each row may have holes with different major and minor axis length. The fluid scoop portion of the hole is elevated above the surface of the diffuser plate. The plates depend from the bottom of the draw jet-slot extension assembly and which lower adjustable ends may be abutted to vacuum seal rollers or other sealing means, or open to the atmosphere.
[0056] In the case where the plates are open to the ambient atmosphere the ends of the plates are adjusted to the correct distance above the foraminous belt. The distance of the two plate ends above the foraminous belt may be equal or unequal.
[0057] Generally in the case where the ends of the plates are open to the ambient atmosphere the deposition of fibers is more uniform if the longer plate is on the up stream side in reference to the belt travel direction.
[0058] These plates contain a multiplicity of fluid holes which are controllable as to total area by the use of a slide gate or other means. The holes or amount of open area controls the amount and pressure of fluid in the diffuser and controls turbulence but allows the ambient fluid to be automatically entrained. This has a beneficial effect on the uniformity of filament lay down by controlling the rate of deceleration of the filaments.
[0059] The filaments begin to decelerate upon entry into the fluid control system and begin to describe a downward spiraling motion which assists in developing a uniformly isotropic web deposited on the foraminous conveyor belt used to receive and convey away the web. The fluid volume control system is adjustable as to the diffuser angle and open area.
[0060] When the included angle between the two halves is wide the swirl approaches an elliptical appearance with the longer axis in the machine direction. Narrowing the included angle shifts the elliptical pattern to the cross direction. Proper angle and fluid flow adjustment of the fluid volume control diffuser is based on belt speed and required areal web weight so that the resultant swirl pattern on the moving belt is most nearly circular. A circular pattern provides the most isotropic product physical characteristics wherein the machine to cross direction ratios of physical properties such as tensile strength and elongation approach a ratio of 1:1. This is significantly better than typical spunbond fabrics which generally have ratios in the 2:1 or higher range especially at low areal weights and high belt speeds. The narrower ratio permits lighter weight fabrics to be safely used in applications such as disposable diapers where cross direction tensile strength is an important consideration from both the diaper manufacturing and end use requirements.
[0061] In order to maintain complete and total control of the system fluid and also reduce the load on the under belt suction device it is necessary to prevent the incursion of ambient fluid into the space between the outlet of the diffuser system and the belt as well as between the belt and the plenum.
[0062] This is accomplished by creating a sealing system where the lower end of each fluid volume control diffuser system plate assembly is affixed to a curved surface which is slidingly adjoined to a set of upper vacuum seal rolls. This effectively seals the control system against fluid being sucked in at the lower edges of the volume control system thus minimizing any possible turbulence which might interfere with filament lay down. The curved surface is designed such that surface is continually in sliding contact with the surface of the stationary vacuum seal rolls. regardless of the angle of the diffuser system. The curved surface or shoe is covered with a replaceable low pile fabric to aid in sealing. Alternatively the rolls may be covered with fabric.
[0063] The two above the belt sealing rolls are paired with two below the belt sealing rolls in order to provide an essentially leak proof connection between the diffuser ends and the upper opening to the vacuum plenum. The lower sealing rolls are also slidingly sealed to the plenum. The lower or suction opening of the vacuum plenum is connected to a variable volume suction blower or other variable volume suction pressure device by a duct.
[0064] To decrease the web thickness prior to the deposition of an additional web or the web bonding step it is compacted by a driven web compaction roll set directly after leaving the vacuum area.
[0065] The variable speed foraminous collector screen or belt then delivers the web or multiple webs to a filament bonding station, such as thermal pattern bonding or other means of web bonding or interlocking.
[0066] It is anticipated that this unique spunbond system will be used in combination with a meltblown system and a second unique spunbond system to provide a unique in-situ three web laminate. It is further anticipated that this unique spunbond system will be used in combination with a meltblown system to provide a unique in-situ two web laminate.
[0067] It is further anticipated that using the instant invention, spunbond fabrics with average filament sizes below 0.7 denier will have, opacity, resistance to liquid penetration and other physical and performance properties comparable to SMS webs.
[0068] Glossary of Terms
[0069] In order to better understand the terminology used herein, particularly those terms which may be ambiguous with respect to some prior art or which have been indiscriminately used without explanation in the prior art, the following definitions are submitted.
[0070] Aspirate: to draw by suction
[0071] Aspirative means: a means by which an internal force such as a suction or differential pressure sucks or draws fibers or fluid through a passage or slot
[0072] Buffer zone: see quench fluid extraction zone
[0073] Capillary: refers to the resin extrusion orifice or any other drilled hole or perforation that serves as an orifice
[0074] Crystallinity: the relative fraction of highly ordered molecular structure regions compared to the poorly ordered amorphous regions as determined by X-ray or other appropriate analytical means
[0075] Die head: refers to complete structure containing the spinnerets, resin distributors and other associated filament extrusion equipment and which extends across the full width of the spunbond machine, also referred to as a die beam
[0076] Diffuser: a diverging channel transition system for controlled reduction of the velocity of the fluid and filaments exiting the filament drawing system and entering the filament lay-down system
[0077] Educt: to draw out
[0078] Eductive means: a means by which an external force such as a suction fan creates a differential pressure that draws fibers or fluid out through a passage or slot
[0079] Fluid volume control plate open area: the ratio of the actual area of the holes as precluded by the slide control plate to the total area of the fluid-scoop holes
[0080] Induct: to bring in
[0081] Inductive means: a means by which an external force such as a pressure fan creates a differential pressure that transports or brings fibers or fluid into or through a passage or slot
[0082] Infuser: a converging channel transition system for controlled funneling of fluid and filaments into the filament drawing system
[0083] Jet: a slot, nozzle, perforation or other orifice through which a fluid may be emitted or drawn in and which may have an opening that is round, rectangular, or any other shape without regard to length or diameter
[0084] MD/CD ratio: ratio of a fabrics machine direction to cross direction properties typically used as a measure of isotropic formation
[0085] Quench fluid extraction zone: That portion of the area between the quench cabinets where the bilateral quench fluid streams meet and descend into the fluid volume control infuser
[0086] Resin: refers to any type of material that may be liquefied to form fibers or nonwoven webs including, without limitation, polymers, copolymers, thermoplastic resins, waxes, emulsions and the like
BRIEF DESCRIPTION OF THE DRAWINGS
[0087] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
[0088] [0088]FIG. 1 is a vertical cross section through one embodiment of the apparatus of the invention;
[0089] [0089]FIG. 2 is vertical cross section through a second embodiment of the apparatus of the invention;
[0090] [0090]FIG. 3 a is a plan view of a fluid scoop plate of the volume control system
[0091] [0091]FIG. 3 b is a side sectional view (X-X) of a fluid scoop plate of the volume control system
[0092] [0092]FIG. 4 a is a side view of a fluid scoop plate of the fluid volume control system showing the arrangement of the volume adjustment plate in the fully open position
[0093] [0093]FIG. 4 b is a side view of a fluid scoop plate of the volume control system showing the arrangement of the volume adjustment plate in the fully closed position
[0094] [0094]FIG. 4 c is a side view of a fluid scoop plate of the volume control system showing the arrangement of the volume adjustment plate in the partially open position
[0095] [0095]FIG. 5 is a detailed view of the supplemental draw jet slot extension and fluid acceleration devices
[0096] [0096]FIG. 6 is a detailed view of the supplemental draw jet slot extension, lower volume control plates, and lower volume control plates sealing system.
[0097] [0097]FIG. 7 is a vertical cross section through the draw jet-slot assembly of the apparatus in detailed form;
DETAILED DESCRIPTION
[0098] The invention is described in connection with preferred embodiment, however it should be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the description as well as within the spirit and scope of the invention as defined by the appended claims.
[0099] The apparatus shown in FIG. 1 generates a continuous spun-bond web from aerodynamically stretched filaments of a thermoplastic synthetic resin. Molten thermoplastic resin produced by an extrusion device (not shown) enters the inlets 1 to the pressurized fluid metering system 2 a , 2 c for distribution to the parallel micro-coat hanger distribution systems 3 a & 3 c . The pressurized fluid metering system is unique in that each pressurized fluid metering device has 2 or more individual outlets or in the instant case 6 outlets. Each individual pump outlet feeds an individual micro-coat hanger or three dimensional fluid distributor The micro-coat hanger distribution system systems 3 a & 3 c feeds the spinnerets 4 a , 4 c.
[0100] A unique aspect of the micro-coat hanger melt extrusion distribution system is that each coat hanger is supplied resin from an individual feed supply and feeds only from 50 to 250 millimeters of die length. In the instant embodiment each coat hanger feeds 100 millimeters of die length. This insures precise control of the amount of resin reaching the filament extrusion orifices. Consequently the flow rate at each orifice is very consistent, and along with the other inventions that make up this process and its resulting web product, results in a very narrow range of filament diameters at a given set of conditions with a specific orifice diameter.
[0101] The spinneret head with its dual spinning sections 4 a , 4 c , is separated by a buffer segment and quench fluid extraction zone. 5 . Two cascades of filaments 110 a , 110 c emerge from the discrete spinnerets 6 a, c and are contacted with quench fluid from the quench process fluid manifolds. The number of spinning orifices or capillaries per centimeter of cross directional die width is more than fifty percent greater than conventional spunbond dies. In the spinneret head 4 the space 33 between the two spinneret sections 4 a and 4 c provides a buffer zone 5 to prevent left and right side quench fluids from impinging on each other within the dense filament curtains descending from the two spinneret sections. It was previously discovered impingement of the opposing fluid streams in the buffer zone was not an issue if the filament density in the buffer zone was about eighty percent or less of the filament density in the dual spinning sections. The buffer zone can then, alternatively, be used to provide additional die holes in the spinneret. FIG. 2 shows the apparatus with a lower density spinning segment 4 b . The low density filament curtain 110 b is shown leaving discrete spinneret 6 b . Also shown is the additional pressurized fluid metering system 2 b , for distribution to the parallel micro-coat hanger distribution system 3 b . The capability to use more holes per meter of die width permits even higher overall throughput per meter and further reduces the loss of throughput when producing low and sub-denier fibers. The uniform quenching promotes an extremely narrow and uniform drawn filament diameter range. This is an important factor not present in the prior art. The buffer zone with and without the low density perforations also provides a non-turbulent turning region for the quench streams to combine and be entrained in the downward movement of the filament cascade.
[0102] The quench fluid system which consists of two opposed assemblies of at least three individual manifolds zones 24 a, b & c , 25 a, b & c each of which operates at an individually controllable volume and temperature. The fluid volume and temperatures in each section may be controlled so that any temperature sequence, within the controlled range, may be attained thus, for instance, enabling a delayed quench or a warm annealing step to be followed by a cold quench. This is a necessary step in making high tenacity fibers from materials such as polyester or other materials with distinct glass transition temperatures (T g ). The opposed and separate nature of dual spinnerets and separately controlled bilateral quench also permits the use of two different but compatible resins, one on each side, or a differentially quenched bicomponent filament. The quench fluid is required for the solidification and crystallization process of each filament leaving the spinnerets 6 a , 6 b . In the instant invention each quench stream of the three quench fluid manifolds on each side delivers quench fluid at an individually controlled temperature ranging from 20° F. to 200° F. Each of the three quench fluid zones 24 a, b & c , 25 a, b & c is separately temperature controlled by temperature control means. The quench fluid is delivered to the unit by a pressurized fluid system which may have one or more blowers and one or more heat exchangers, each with its own pressure control allowing precise independent adjustment of the quench velocity within the range of 30 to 1000 meters per minute depending on the specific resin, mass throughput and other process requirements.
[0103] After quenching, the filaments descend through an adjustable fluid volume regulation system or fluid volume control infuser system 17 which depends from the lower inner edges of the quench system to the draw jet-slot inlet 8 of the draw jet assembly 27 . The fluid volume control infuser system consists of two opposed 17 specially perforated fluid regulation plates 19 as shown in FIGS. 3 & 4. The reversed fluid-scoop type perforations 14 permit excess quench fluid to automatically bleed off into the atmosphere based on the fluid pressure difference across the plate assembly. The major axis length of each perforation is from 2 millimeters to 150 millimeters.
[0104] The open area of the adjustable specially perforated fluid regulation plates ranges from 5 percent open to 100 percent open. The preferred range is 20 percent to 80 percent. In the instant example open area was 60 percent. This is based on the total area of all the holes in the plate. Total open hole area can range from 10 percent to 70 percent of the perforated area of the plates. The holes are located in the upper portion of the plates. Up to 90 percent of the vertical height may be perforated. In the instant example the perforated portion was 80 percent.
[0105] Each perforated plate's length is adjustable by a slide means 15 in the vertical direction in order to accommodate the relative changes in the distance between the lower surface of the quench system 16 and the upper surface 71 of the draw jet-slot assembly to which its lower edges are attached 18 . This angle can be between 20 and 120 degrees. The perforated plate 19 assemblies also contain a flat perforated slide valve plate 20 of FIG. 4, the perforations of which normally index with the reversed fluid-scoop type perforations of the fluid regulation panels which gives a full open system. Both lateral ends of the V-shaped channel created by the adjustable fluid regulation system are closed by an adjustable sealing means.
[0106] The filament draw system FIG. 1 consists of a draw jet assembly 27 that contains a variable width draw jet-slot 9 and variable width draw jet-nozzles 29 a, b . FIG. 7 a and 7 b . The assembly consists of a right and a left hand vertical halves 25 a, b which are generally parallel. The right and left hand vertical halves are moveable horizontally in relation to each other by a screw adjuster system. The space between the left and right vertical halves defines the variable width draw jet-slot 9 used to vary drawing velocity. The variable jet-slot gap “S” FIG. 7 a , is adjustable between about 1.0 millimeter and 15 millimeters and is generally constant over the vertical length between the entrance and exit of the draw jet-slot. The draw jet assembly 27 extends vertically downward to the draw jet extension and horizontally the width of the spinneret head. The upper surfaces of both the right and left hand halves of the assembly 25 a, b contain moveable and precisely adjustable nozzle plates 26 a, b that are moveable horizontally in relation to the slot wall and serve to define the variable width draw jet-nozzles 29 a, b . FIG. 7 a shows the angle A formed by the center line of the primary jet-nozzle and the centerline of the draw jet-slot is 15 degrees. The draw jet assembly 27 is also moveable by a hydraulic, or screw jack system in order to adjust the distance between the spinnerets and the draw jet-slot entrance.
[0107] The variable orifice jet-nozzles 29 a, b . formed by the adjustable nozzle plates and the upper edges of the vertical halves 25 a, b provide very high velocity motive fluid for the drawing process extend the full horizontal width of the draw jet-slot, which with the fluid pressure and temperature control of the variable pressure blower and heat exchanger provides precise regulation of the drawing fluid velocity and temperature. The angle A of the draw jet-nozzles, as shown in FIG. 7 a , with respect to the vertical has a broad range from about 5 degrees to about 60 degrees. The preferred range is 20 degrees ±8 degrees. In the instant example the angle is 15 degrees. The gap of the variable orifice jet-nozzles 29 can range from about 0.5 millimeters to about 6 millimeters. The tempered fluid is supplied to the draw jet-nozzle's inlets 7 a , 7 b of FIG. 7 a from the heat exchanger through a pressure equalizing distributor. The combination of precisely controlled quench fluid temperature and velocity permits each resin to be conditioned to the outer filament temperature required to optimize drawing in the slot and venturi sections.
[0108] After drawing fluid velocity is established the two halves 25 a, b of the draw jet assembly 27 are adjusted to give the required jet-slot gap S of FIG. 7 a to optimize the motive fluid velocity in the slot.
[0109] The distance of the surface of the draw jet assembly 27 from the lower surface of the spinnerets is adjustable from between about 400 millimeters and 1200 millimeters in order to maximize draw forces and filament attenuation which affect the reduction of filament denier and the increase in crystallinity.
[0110] The vertical ends of the variable slot 9 are closed at their lateral or cross machine ends by an adjustable sealing means.
[0111] As the filaments accelerate through the slot they pass between one or more opposed and offset secondary draw jet-nozzles 36 a, b of FIG. 7 a . The offset jets create perturbations across the slot 9 which induce a sinusoidal motion of the filaments which expose a greater surface area of the filament to the fluid stream. This creates a higher drag coefficient which transfers a higher amount of energy to the filaments creating a higher filament speed which improves the reduction of filament denier.
[0112] The secondary jet-nozzles, which may also have an adjustable gap, are offset vertically 30 by a centerline distance of from 1 millimeter to 50 millimeters. In the instant example the offset was 20 millimeters. The angle “B” in FIG. 7 a formed by the centerline of the secondary jet-nozzle and the centerline of the draw jet-slot ranges from about 2 degrees to 45 degrees. The preferred angle of impingement ranges from 10 degrees to 20 degrees. In the instant case the angle was 15 degrees. A variable speed blower and heat exchanger supply the high pressure, temperature controlled fluid used to provide the motive force.
[0113] Alternatively, one or more opposed secondary jet-nozzles 36 a , b. can be fed by high pressure fluid from a blower that has been sent to a variable speed rotating splitter (three way) valve (not shown) which alternates pressurized fluid between inlets 35 a, b . This provides alternate pulses between jets 36 a and b which also induces a sinusoidal motion of the filaments with a sharp increase in filament velocity.
[0114] [0114]FIG. 7 a shows the angle B formed by the centerline of the secondary jet and the centerline of the draw jet-slot is 15 degrees in this embodiment. The broad range of the jet angle B formed by the centerline of the secondary jet and the centerline of the draw jet-slot, with respect to the horizontal axis, is from about +80 degrees to about 0 degrees. The secondary jet-nozzle gap 36 a, b range from about 0.5 millimeter to about 6 millimeters.
[0115] An alternative method shown in FIG. 7 b for creating a sinusoidal motion of the filaments within the slot is to offset the variable primary jet-nozzles 29 a, b horizontal centerlines vertically 31 by between about 2.0 millimeters to about 20 millimeters as a broad range with 3.0 millimeters to 10 millimeters as the favored range.
[0116] Filaments then enter the supplemental draw jet slot extension system 51 shown in FIG. 5. The adjustable slot extension depends vertically downward from the lower surface of the draw jet assembly 27 , to which it is slidingly affixed to permit horizontal slot and venturi adjustment. The slot width of the draw extension is adjustable by means of a screw adjustment. The gap is adjustable between about 1.0 millimeter and about 15 millimeters and is generally constant over the vertical slot between the entrance and exit of the draw jet assembly. In the instant example the gap is 4 millimeters. This slot contains a first venturi 11 or other fluid acceleration means to further increase fluid velocity and prevent any loss of filament velocity in the system and maintain constant tension or increasing tension, on the filaments. The half angle of approach 57 to the venturi as shown in FIG. 5, ranges from about 1 degree to about 10 degrees whereas the half angle of recession 58 is from about 1 degree to about 12 degrees. In the preferred embodiment the angles are 3 degrees and 5 degrees respectively.
[0117] The venturi gaps 52 _range from between about 1.0 millimeter and about 10 millimeters. The ratio of the venturi gap to the slot width in the draw jet extension ranges from about 0.95 to about 0.3. In the instant invention the venturi gap is 3 millimeters.
[0118] After leaving the first venturi there is a set of adjustable inlet apertures 53 on both sides of the slot that are used to create a series of micro-vortices in the wall boundary layer. This creates a minor degree of turbulence in the boundary layer prior to the second venturi.
[0119] Subsequent to the first set of adjustable inlet apertures 53 is a second venturi 12 or other fluid acceleration means to prevent any loss of filament velocity in the system thereby continuing to maintain tension on the filaments. The half angle of approach to the second venturi 12 ranges from about 1 degree to 10 degrees whereas the half angle of recession 41 is from 1 degree to 12 degrees in the preferred embodiment the angle are 3 degrees and 5 degrees respectively. This venturi is also variable in width. The second venturi gap 52 ranges from between about 1.0 millimeter and about 10 millimeters. The ratio of the venturi gap to the slot width in the draw jet extension ranges from about 0.3 to about. 0.95.
[0120] Below the exit of the second venturi is an additional set of adjustable inlet apertures 54 on both sides of the slot that are used to create a series of micro-vortices in the wall boundary layer. This creates a minor turbulence in the boundary layer prior to the point at which the draw jet extension slot width increases due to the adjustable length means 56 and near the end of the draw jet extension immediately prior to the exit into the fluid control system.
[0121] The slot extension's length is adjustable in the vertical plane by a sliding means 56 to accommodate the changes in elevation created by optimizing the distance of the draw jet assembly from the spinneret lower surface and optimizing the distance of the lower fluid control diffuser system from the surface of the collector. The width of the slot and venturi in the slot extension is also variable through horizontal adjustment means for further optimization of filament velocity.
[0122] Depending from the lower slot extension is the adjustable fluid regulation system diffuser or volume control diffuser system which consists of an assembly of two opposed specially perforated fluid volume control plates FIG. 6.
[0123] Each perforated plate is adjustable by a slide means 15 in the vertical direction in order to accommodate the relative changes in the distance between the lower surface of the supplemental draw jet slot extension system 108 and the surface of the seal rolls 62 . The included angle of the perforated plates of the diffuser assembly is adjustable, by an adjustment screw from 10 degrees to 120 degrees, measured from the vertical axis, as required to optimize fiber lay down and maximize the formation of isotropic properties within the web. Adjacent and coterminous with the fluid-scoop type perforated plate 19 lies a flat perforated slide valve plate 20 , the perforations of which normally index with the fluid-scoop type perforations of the fluid regulation plates. Taken together they are referred to as the fluid volume control plate assembly. Lateral movement of slide valve plate 20 gradually occludes the air scoop perforations 107 and reduces the fluid flow in or out of the adjustable fluid volume control system diffuser as process operating conditions require.
[0124] The purpose of the lower adjustable fluid volume control system is to permit ambient fluid to automatically bleed into the diffuser depending on the fluid pressure difference across the plate and simultaneously prevent turbulence at the exit of the draw slot while maximizing the randomness of filament distribution on the foraminous web collection system which will permit the formation of near isotropic physical properties within the web. The adjustment features of the diffuser also permit optimization of filament distribution and physical properties regardless of collector speed.
[0125] The adjustable open area of the adjustable specially perforated fluid regulation plate assemblies ranges from 5 percent open to 100 percent open based on the total area of all the holes in the plate assembly. Total open hole area can range from 10 to 60 percent of the perforated area of the plates. The preferred range is 20 percent to 80 percent. In the instant example open area was 60 percent. The major axis length of each perforation is from 2 millimeters to 150 millimeters. The holes are located in the upper portion of the plates. The portion of the plate that is perforated ranges between 20 percent and 90 percent of the vertical height of the plate. In the instant example perforated portion was 80 percent.
[0126] The lower end 61 of each fluid volume control diffuser system plate assembly 59 is affixed to a curved surface 60 which is slidingly adjoined to the upper vacuum seal rolls 62 and effectively seals the control system against fluid being sucked in at the lower edges of the volume control system thus minimizing any possible turbulence which might interfere with filament lay down. The curved surface 60 is designed such that surface is continually in sliding adjoinment contact with the surface of the vacuum seal rolls thus the rolls can remain fixed in horizontal position. The curved surface is covered with a replaceable low pile fabric to aid in sealing.
[0127] A vacuum plenum 80 connected to variable suction pressure means is located beneath the surface of the variable speed foraminous collector screen 83 which runs between the upper 62 and lower 63 vacuum seal rolls. The two upper belt sealing rolls are oppositely and directly paired with two lower belt sealing rolls in order to provide an essentially leak proof connection between the diffuser ends and the vacuum plenum which is attached by duct to a controllable suction blower (not shown).
[0128] The web is compacted by a driven web compaction roll set 84 & 85 after leaving the vacuum area.
[0129] The variable speed foraminous collector screen or belt 83 then delivers the web to a filament bonding station, such as thermal pattern bonding or other means of web bonding or interlocking.
PROCESS EXAMPLES
[0130] The following experiments and the overall resultant data, as shown in Tables 1 through 6 below, demonstrate the intimate interrelationship between the apparatus, the process and the final spunbonded product.
[0131] The compound and synergistic effects of the multiple draw jets, multiple venturis, fluid volume control infuser and diffuser on high speed attenuation and production of a unique spunbond material are shown in Table 1 in accordance with the process of the present invention.
[0132] A one meter wide laboratory system with interchangeable central segments, one non-perforated and one with a 40% perforation density, was used for the following experiments. Using polypropylene with a 35 melt flow index the extrusion system and draw jet system was adjusted or modified to the various process conditions and settings shown in Tables 1, 2, 3, and 4. For those conditions not specifically shown therein the conditions and settings as shown in Table 5 were generally used.
[0133] The process tests shown in Table 1 were run using both alternative die heads. No substantive differences were found between the 40% perforation-density central segment and the non-perforated central segment as far as process and product performance was concerned with the exception of the expected higher total throughput when using the 40% perforation-density central section.
[0134] The first experiment, designed to evaluate component stage efficiency, was conducted by starting out with only the fluid volume control infuser assembly, the draw jet assembly, and the supplemental draw jet extension without venturis. Only the primary draw jet-nozzle or first draw jet-nozzle was used. In each subsequent experiment a different component of the invention was added and tested. Fiber velocities and filament diameters were checked for each experimental run. Each new component that was added was run at the same conditions shown in Table 5. The filament curtain extruding from the spinnerets was captured in the draw jet slot at an initial slot setting of 4 millimeters. This was gradually decreased to 2 millimeters to obtain minimum fiber diameter as determined by measuring fiber diameters using a microscope. Simultaneously with narrowing of the slot the draw jet assembly was elevated from its start-up position of about 1000 millimeters below the bottom of the spinneret to about 500 mm. The point was determined by spinning performance and minimum denier obtainable. These data were used as a baseline for further incremental testing of the remaining components.
[0135] The next step was to turn on the secondary draw jet-nozzles. The secondary jet-nozzles were positioned 20 millimeters below the primary jet and one offset 3 millimeters. Fluid volume was increased until the denier was minimized. This step had the remarkable effect of increasing fiber velocity by 35 percent and reducing average denier by 32 percent.
[0136] At this point a draw jet extension with one venturi was attached to the base of the draw jet assembly. After reaching process equilibrium fiber denier was optimized by making minor adjustments to the fluid flow of the primary and secondary jet-nozzles. The draw jet extension slot gap was set at 3.8 millimeters and the first venturi gap was set at 2 millimeters.
[0137] Next, the single venturi draw jet extension was replaced with a dual in-line venturi draw jet extension. After reaching process equilibrium fiber denier was optimized by making minor adjustments to the fluid flow at the primary and secondary jet-nozzles. The draw jet extension slot gap was set at 3.8 millimeters and the primary and secondary venturi gaps were set at 2 millimeters.
[0138] The data showed that there was a significant fiber velocity increase and corresponding significant filament denier decrease with the addition of each additional component. The total overall improvement compared to the base case fiber velocity was nearly 46 percent. The highest single component stage improvement was a 35 percent improvement between draw jets 1 and 2. This is believed to be primarily due to the greater horizontal cross-section filament surface area exposed to the drawing fluid due to the oscillation of the filament curtain and secondarily to the higher draw fluid velocity due to higher volume. The velocity increase between subsequent sections was smaller but the gross effect was an increase of almost 10 percent which resulted in a 4 percent decrease in denier.
[0139] In further testing the sub-denier fabrics were examined for opacity and hydrophobicity. Both properties were found to be from 20 percent to 70 percent higher than the typical 14 gram per square meter spunbond fabrics because of the instant inventions greater uniformity cover and sub-denier fibers. Disposable diaper fabric was not used as the reference fabric in order to eliminate low hydrophobicity results caused by the addition of surfactants.
[0140] The end product result using all of the draw line components was a very uniform 14 gram per square meter web having an average filament denier of 0.85, excellent fabric tenacity, greatly improved hydrophobicity and excellent opacity. Output of resin was in excess of 0.9 grams per hole per minute at an average denier of 0.85 and in excess of 1.2 grams per hole per minute at an average denier of 0.98.
TABLE 1 Effect Of Drawing Section Apparatus Components On Fiber Velocity And Denier Run # 1 2 3 4 5 Components used Infuser Infuser Infuser Infuser Infuser Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 2 Draw jet 2 Draw jet 2 Draw jet 2 Venturi 1 Venturi 1 Venturi 1 Venturi 2 Venturi 2 Diffuser Fiber velocity @ ext. exit (M/min.) 4900 6600 6800 6950 7150 Fluid to Fiber Velocity Ratio 3.2 2.5 2.4 2.4 2.3 Velocity increase from prior stage % 34.7 3.0 2.2 2.9 Total Fiber Velocity Increase 45.9 (Runs 1 to 5) % Filament Denier Average 1.36 0.90 0.88 0.87 0.85 Fabric Weight (g/M 2 14 14 14 14 14 Fabric Tenacity MD 51 48 49 48 48 Fabric Tenacity CD 45 43 42 41 42 Relative Opacity (% greater than) 24 42 43 44 51 (compared to 2.5 denier 14 gsm commercial SB)
[0141] In a second test series data was gathered on the effect of diffuser open area and diffuser angle settings on the spunbond uniformity as measured by MD/CD strength ratios. Testing was done at three different collector belt speeds.
[0142] The volume control diffuser system plate assembly angles were set between 10 degrees and 40 degrees with a collector belt speeds of 300 meters to 600 meters per minute. Diffuser open area was varied between 30 percent and 70 percent. Diffuser plate assembly vertical length was 500 millimeters. All other process conditions and settings were either maintained or slightly adjusted through the test sequences.
[0143] The resultant data is shown in Tables 2, 3 & 4. The results showed that by changing the diffuser a surprisingly effective control was achieved over the deposition pattern of the filaments exiting the draw jet extension. By changing the angle of the diffuser's fluid volume control plates and their amount of open area the machine direction to cross direction ratio (MD/CD ratio) of fabric tensile strength can be altered to meet whatever ratio is required. In most cases a ratio of about one to one (1:1) is desirable. However in some case where higher cross direction strength is desirable, such as disposable diaper cover sheet, this can also be accomplished.
[0144] A further experiment was done using a commercial polyester having an intrinsic viscosity of 0.64. The results, shown in Table 6, showed that fiber denier was greatly reduced. Fabric uniformity as measured by MD/CD tensile properties showed improvements similar to the polypropylene data.
TABLE 2 Effect of Diffuser Angle Settings On MD/CD Ratio @ 300 M/min. Belt speed Run Number 1 2 3 4 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 300 300 300 300 DOA* MD/CD** MD/CD** MD/CD** MD/CD** 30 0.18 0.44 1.36 2.47 50 0.27 0.70 2.11 3.12 70 0.53 0.95 2.51 3.62
[0145] [0145] TABLE 3 Effect of Diffuser Angle Settings On MD/CD Ratio @ 450 M/min. Belt speed Run Number 5 6 7 8 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 450 450 450 450 DOA* MD/CD** MD/CD** MD/CD** MD/CD** 30 0.23 0.97 1.95 3.08 50 0.52 1.45 2.60 3.44 70 1.03 1.88 3.27 4.23
[0146] [0146] TABLE 4 Effect of Diffuser Angle Settings On MD/CD Ratio @ 600 M/min. Belt speed Run Number 9 10 11 12 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 600 600 600 600 DOA* MD/CD** MD/CD** MD/CD** MD/CD** 30 0.41 1.33 2.37 3.35 50 1.09 2.18 3.14 4.12 70 1.67 2.65 3.76 4.83
[0147] [0147] TABLE 5 General Process Settings Polymer Type PP PET Polymer Viscosity 35 MF 0.64 IV Polymer Melt Temp. ° C. 225 325 Polymer Throughput kg/hr/M 340 to 460 340 to 460 Orifices per meter of width Number 6200 6200 Metering Pump Streams Number 16 16 Quench Fluid Temp. #1 ° C. 7 8 Quench Fluid Temp. #2 ° C. 9 8 Quench Fluid Temp. #3 ° C. 12 8 Quench Fluid Volume #1 M3/min 15 34 Quench Fluid Volume #2 M3/min 7.5 17 Quench Fluid Volume #3 M3/min 7.5 17 Quench Fluid Volume Total M3/min 30 68 Upper Control Plates Angle Degrees 30 42 Control Plates Hole Size mm 30 30 Control Plates % Open % 30 to 70 50 to 90 Primary Draw Fluid Volume M3/min 38 46 Primary Draw Fluid Pressure Bar 1 to 3 1 to 3 Draw Fluid Temp ° C. 15 to 30 15 to 30 Primary Jet-nozzle Gap mm 0.5 to 3 0.5 to 3 Primary Jet-nozzle Angle Degrees 15 15 Secondary Jet-nozzle Gap mm 0.5 to 3 0.5 to 3 Secondary Jet-nozzle Angle Degrees 15 15 Secondary Jet Fluid Volume M3/min 10 10 Draw Jet-slot Gap mm 2 to 8 2 to 8 Extension Slot Gap mm 2 to 8 2 to 8 Extension Venturi #1 Gap mm 1.5 to 4 1.5 to 4 Extension Venturi #2 Gap mm 1.5 to 4 1.5 to 4 Lower Control Plates Angle Degrees 10 to 40 10 to 40 Control Plates Hole Size, diameter mm 30 30 Control Plates % Open % 10 to 80 10 to 80
[0148] [0148] TABLE 6 Effect Of Drawing Section On Polyester Run # 17 Components used Infuser Draw jet 1 Draw jet 2 Venturi 1 Venturi 2 Diffuser Fiber velocity @ ext. exit (M/min.) 7600 Fluid to Fiber Velocity Ratio 2.1 Filament Denier Average 0.85 Fabric Weight (g/mm 14 Fabric Tenacity MD 77 Fabric Tenacity CD 62
[0149] While preferred embodiments of the present invention have been described in the foregoing detailed description the invention is capable of numerous modifications, substitutions and deletions from the embodiments described above without departing from the scope of the following claims.
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A unique isotropic sub-denier spunbond nonwoven product created by an apparatus and method comprising a unique multi-head resin metering system, a spinneret head with spinning sections, separated by a quench fluid extraction zone, a two sided, multilevel quench system, a fluid volume control infuser system which automatically guides the filaments into the filament drawing system while conserving energy by using a portion of the quench fluid as part of the drawing fluid and also minimizing turbulence at the entrance to the draw slot. The filament drawing system comprises a draw jet assembly with adjustable primary and secondary jet-nozzles and a variable width draw jet-slot. The entire draw jet assembly is moveable vertically for filament optimization. The offset, constant flow secondary jet-nozzle system provides an unexpectedly high velocity increment to the filaments by oscillating the filaments and increasing their drag resulting in remarkably low fiber denier on the order of 0.5 to 1.2. The apparatus also embodies a draw jet extension with an adjustable slot and contains two in-line or tandem which are also adjustable and maintain fiber tension and draw force through the lower end of the draw system. Drawn filaments are decelerated in an adjustable fluid volume control diffuser system which controls the amount and pressure of fluid in the diffuser and controls turbulence. The filaments enter into the fluid control system and begin to describe a downward spiraling motion results in remarkably uniform isotropic web where the machine to cross direction ratios of the bonded web physical properties such as tensile strength and elongation approach a ratio of 1:1.
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FIELD OF THE INVENTION
[0001] The present invention relates to packages, and more specifically to a package including a compartment for holding a number of ancillary items therein that are to be utilized with the primary item disposed within the package.
BACKGROUND OF THE INVENTION
[0002] Packages for various items come in numerous shapes and configurations in order to adequately hold the different items therein. These packages most often generally conform to the particular shape of the item held therein in order to minimize the amount of material required to form the package. However, with regard to certain items that can be held in packages of this type, the utilization of these primary items requires additional components or ancillary items to be inserted within or otherwise engaged with the primary items for proper operation of the primary item.
[0003] In these situations, oftentimes a manufacturer of the primary item will develop packaging for the primary item that enables ancillary items required for proper operation of the primary item to be included within the packaging. Most often, the packaging will include one enclosure for the primary item and a separate enclosure for the ancillary items in order to clearly illustrate to a consumer that both the primary item and the ancillary item or items are present within the package.
[0004] Additionally, other packaging designs have been developed for holding both primary items and ancillary items therein that include an entirely separate package to hold the ancillary items therein. The separate ancillary item package is simply placed against or attached to the exterior of the package for the primary item, such as by being adhered to the exterior of the primary item package by an adhesive, or by a shrink wrap disposed about both the primary item package and the ancillary items package, for example.
[0005] However, in constructing packages in this manner, a significant additional amount of packaging material is required to form the additional or separate package within which the ancillary items are to be disposed. Further, if the primary item and the ancillary items are held in separate packages or enclosures within the packaging, when the packaging is initially opened, the compartments or separate packages for the primary and ancillary items can easily become disassociated from one another, resulting in the ancillary items being misplaced and unable for proper use in conjunction with the primary item.
[0006] As a result, it is desirable to develop a packaging for holding a primary item and ancillary items to be utilized with the primary item therein in a manner which does not require significant additional amounts of packaging material. Further, the packaging should be capable of holding and retaining the primary item and the ancillary items reduce the chances that they will become disassociated from one another both prior to and after the initial removal of the items from the packaging.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the present invention, a package is provided for containing a primary item and one or more ancillary items therein in which the package includes an inner container designed to hold both the primary item and the ancillary items therein that is contained within an outer container. The outer container forms an enclosure around the inner container holding the primary item and the ancillary items, and can be secured in a closed position in any suitable manner to prevent access to the inner package and the items. The inner container is removably positioned within the outer container in a manner that allows the inner container, including the primary item and the ancillary items, to be easily withdrawn from the outer container. The inner container further includes a first compartment designed to hold the primary item therein, and a second compartment adapted to receive the ancillary items therein. In this construction for the inner container, when the outer container is opened and the inner container is removed therefrom, both the primary item and the ancillary items are maintained in an associated relationship with one another within the inner container. In addition, the ability to hold both the primary item and the ancillary items within the inner container enable the inner container to be utilized as the primary packaging vehicle during assembly of the items into the overall packaging. This eliminates the need for any supplemental or temporary packaging structure other than the inner container to hold the primary item and ancillary items or package during the assembly of the packaging.
[0008] According to another aspect of the present invention, the ancillary items are positioned within a separate ancillary item container that is received within the second compartment of the inner container. In this construction, the ancillary item container enables one or more ancillary items to be held therein, but also enables the ancillary item container to be engaged in the desired manner within the inner container along with the primary item.
[0009] According to still another aspect of the present invention, one or more of the outer container, inner container, and ancillary item container, or any portion of one or more of these containers, can be formed of a generally transparent material in order to provide a consumer with a relatively unobstructed view of both the primary item and the ancillary items held within the package. The transparency of the containers also enables a consumer to view the primary and ancillary items held within the containers in an upright position, to properly inspect the items through the various containers, such as for damage to the items or to determine the proper orientation for the items.
[0010] Numerous additional aspects, features and advantages of the present invention will be made apparent from the following detailed description taken together with the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawing figures illustrate the best mode currently contemplated of practicing the present invention.
[0012] In the drawings:
[0013] FIG. 1 is an isometric view of a package of the present invention including a primary item therein;
[0014] FIG. 2 is an isometric view of the package of FIG. 1 with the primary item removed;
[0015] FIG. 3 is an exploded, isomeric view of the package and primary item of FIG. 1 ;
[0016] FIG. 4 is an exploded, isometric view of an inner container and ancillary item container of the package of FIG. 1 ;
[0017] FIG. 5 is a cross-sectional view along line 5 - 5 of FIG. 1 ;
[0018] FIG. 6 is a top pan view of a blank used to form the inner container of FIG. 6 ;
[0019] FIG. 7 is an isometric view of the inner container of the package of FIG. 1 ;
[0020] FIG. 8 is a front plan view of the inner container of FIG. 7 ;
[0021] FIG. 9 is a left plan view of the inner container of FIG. 7 ;
[0022] FIG. 10 is a right side plan view of the inner container of FIG. 7 ;
[0023] FIG. 11 is a rear plan view of the inner container of FIG. 7 ;
[0024] FIG. 12 is a top plan view of the inner container of FIG. 7 ; and
[0025] FIG. 13 is a bottom plan view of the inner container of FIG. 7 .
[0026] In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected, attached, or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
[0027] With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a package constructed according to the present invention is indicated generally at 100 in FIG. 1 . The package 100 includes an inner container 102 positioned within an outer container 104 .
[0028] Referring now to FIGS. 1-3 and 5 , the outer container 104 is formed to be generally rectangular in cross-section, including a front wall 106 , a rear wall 108 , a pair of sidewalls 110 and 112 , a bottom wall 114 and a top wall 116 . In a preferred embodiment, each of the respective walls 106 - 116 forming the outer container 104 are integrally formed with one another preferably from a unitary blank of a material suitable for forming an outer enclosed packaging container. In addition, the top and bottom walls 114 and 116 are formed of a number of panels 118 each integrally formed with, and foldable with respect to the front wall 106 , the rear wall 108 or one of the sidewalls 110 and 112 .
[0029] As best shown in FIG. 3 , the bottom wall 114 is most preferably formed by a pair of inter-engaging members 120 and 122 , each integrally formed with and foldable with respect to either the front wall 106 and the rear wall 108 , and to the sidewalls 110 and 112 . The members 120 - 122 can be folded into engagement with one another to form a generally continuous bottom wall 114 for the outer container 104 .
[0030] Opposite the bottom wall 114 , the top wall 116 is formed with a pair of retaining flaps 124 that are integrally formed with and foldable with respect to the opposed sidewalls 110 and 112 , as well as a cover flap 126 integrally formed with and foldable with respect to either the front wall 106 or the rear wall 108 . Opposite to the foldable connection with either the front wall 106 or rear wall 108 , the cover flap 126 includes an engagement tab 128 that extends perpendicularly to the cover flap 126 . The tab 128 can be engaged between the wall of the outer container 104 opposite the cover flap 126 and the retaining flaps 124 to hold the cover flap 126 in a closed position over the interior 130 of the outer container 104 .
[0031] In addition to the above described preferred embodiment, the various walls 106 - 116 , as well as the panels 118 can be initially formed as separate members that are subsequently secured to one another in any suitable manner to form the desired configuration for the outer container 104 . Further, the particular configuration and/or shape of the various walls 106 - 116 and panels 118 can be varied as necessary to be other than rectangular, and the number of sidewalls 110 and 112 and panels 118 can be varied as necessary to form an outer container 104 having the desired shape or cross-section, which can be other than rectangular or square, e.g., polygonal or circular.
[0032] Also, while it is contemplated that any suitable material can be utilized to form the blank from which the outer container 104 is constructed, such as a conventional paperboard or cardboard material, in a particularly preferred embodiment, the material utilized for the outer container 104 is a transparent material, such as a clear acetate. The use of a transparent material to form the outer container 104 enables the consumer to clearly view the primary item or product 500 that is disposed within the inner container 102 held within the outer container 104 . However, it is also contemplated that the material forming the outer container 104 can be formed from a combination of different materials, such as a conventional paperboard material and the transparent material. For example, the outer container 104 can be formed of paperboard that includes openings in its construction over which are applied portions formed of the transparent material in order to form windows through the outer container 104 for viewing of the product located inside the outer container 104 within the inner container 102 . Alternatively, the outer container can include a lower portion formed of one type of material, and an upper portion secured to the lower portion and formed of a different material.
[0033] Looking now at FIGS. 1-4 and 6 - 13 , the inner container 102 is illustrated as including a lower tray member 132 and a supporting structure 134 extending upwardly from a rear portion of the tray member 132 . The tray member 132 is formed with a pair of sidewalls 136 and 138 disposed on opposite sides of a front wall 140 . The sidewalls 136 and 138 are connected opposite the front wall 140 to the supporting structure 134 which forms a rear wall 142 for the tray member 132 . The front wall 140 and rear wall 142 each include a retaining flap 144 foldably connected thereto that are folded inwardly towards one another when the inner container 102 is assembled. The retaining flaps 144 are held in this position by the connection of a pair of interengaging members 146 and 148 foldably connected to the sidewalls 136 and 138 and engaged with one another to form a bottom wall 150 for the tray member 132 . In this configuration, the tray member 132 provides support for the primary item 500 positioned within the interior 152 of the tray member 132 . However, the tray member 132 also defines an open upper end 154 that allows the primary item 500 to be easily inserted into and withdrawn from the tray member 132 and also enables the primary item 500 to be readily viewed when located within the tray member 132 .
[0034] In FIGS. 6-13 , the front wall 140 as an overall height much less than the height of the rear wall 142 to define the open upper end 154 for the tray member 132 , while each of the sidewalls 136 and 138 include upper edges 156 that define a height for a front portion of the sidewalls 136 and 138 is generally similar to the height for the front wall 140 . However, each of the upper edges 156 extends upwardly along each side wall 136 and 138 towards the rear wall 142 , such that the edges 156 define a height for the sidewalls 136 and 138 approximately equal to that of the rear wall 142 at a rear portion of the sidewalls 136 and 138 . The particular shape of the upper edges 156 of each side wall 136 and 138 is selected only to provide the front wall 140 and side walls 136 and 138 with heights appropriate for an individual to adequately view the primary item 500 disposed within the tray member 132 , and can be configured to provide the desired aesthetic appearance. In addition, the shape of each of the edges 156 can be different from one another, if desired. Further, the upper end of the front wall 140 can also have a desired aesthetic design, if desired.
[0035] As best shown in FIG. 6 , in the preferred embodiment for the tray member 132 , the rear wall 142 is integrally and foldably connected to one of the sidewalls 136 or 138 opposite the front wall 140 . A cover flap 158 integrally and foldably connected to the rear wall 142 opposite the retaining flap 144 . The cover flap 158 can be pivoted with regard to the remainder of the rear wall 142 to overlap and engage a pair of securing flaps 160 disposed on each side wall 136 and 138 opposite the interengaging members 146 and 148 . Further, opposite the rear wall 142 , the cover flap 158 includes a number of foldable sections 162 that can be folded independently of one another. These sections 162 are utilized to secure the cover flap 158 to the securing flaps 160 and to the rear wall 142 , in a manner to be described. In addition, the length of the cover flap 158 is preferably slightly longer than the length of each securing flap 160 to provide an engagement point for an individual to grasp the inner container 102 for removal from the outer container 104 .
[0036] Below the cover flap 158 , the rear wall 142 includes a number of support flaps 164 formed within the rear wall 142 around an opening 166 . Each of the support flaps 164 are preferably generally trapezoidal in shape such that, when the flaps 164 are folded in the same direction with regard to the rear wall 142 , the flaps 164 define a generally square aperture 168 within the rear wall 142 , as best shown in FIG. 4 .
[0037] Extending from one side of the rear wall 142 opposite the side wall 136 or 138 to which the rear wall 142 is attached, is a support panel 170 . The panel 170 is spaced from the rear wall 142 by a spacing panel 172 that enables the support panel 170 to be positioned directly behind the support flaps 164 on the rear panel 142 a distance defined by the width of the spacing panel 172 . Opposite the spacing panel 172 , the support panel 170 also includes a securing flap 176 that can be affixed to the side wall 136 or 138 to which the rear wall 142 is attached in order to hold the support panel 170 in the proper position directly behind the support flaps 164 .
[0038] The width of the spacing panel 172 effectively positions the support panel 170 behind the rear panel 142 a distance slightly less than the width of the lowermost support flap 164 . This support flap 164 includes a projection 174 that has a locking tab 177 disposed thereon. When the support panel 170 is properly located behind the rear wall 142 , the pivoting of the lowermost flap 164 including the projection 174 enables the locking tab 177 to be positioned in and engaged with an aperture 178 located in the support panel 170 . The engagement of the tab 177 within the aperture 178 holds the lowermost flap 164 in a generally horizontal position such that the flap 164 can support an item positioned thereon. In addition, because the support panel 170 and spacing panel 172 are spaced on the rear wall 142 above the bottom wall 150 , when the support panel 170 is properly positioned and engaged with the locking tab 177 , a recess 180 is formed within the supporting structure 134 below the support panel 170 . The recess 180 can accommodate additional volume of the primary item 500 that is positioned within the tray member 132 in order to adequately engage and hold the primary item 500 within the tray member 132 . Also, the engagement of the securing flap 176 with the rear wall 142 , such as by an adhesive or other suitable means, provides an attachment point for the foldable sections 162 on the cover flap 158 to secure the cover flap 158 to the rear wall 142 .
[0039] Additionally, when the package 100 is initially being assembled, the inner container 102 can be positioned on a conveyor belt (not shown) to function as the primary assembly structure for the package 100 . In other words, once constructed or erected, the inner container 102 can be placed on the conveyor belt and both the primary item 500 , and the ancillary container 182 with the ancillary items 510 and 520 therein can be inserted into the inner container 102 as it moves along the belt between stations where multiple primary items 500 and ancillary containers 182 are located. Thus, the inner container 102 can additionally function as an intermediate package during assembly of the overall package 100 , eliminating the need for other suitable intermediate packaging or item holding structures. Further, in determining if the various items have been properly positioned within the inner container 102 , a simple vision system (not shown) can be utilized.
[0040] Looking now at FIGS. 3-5 , an ancillary item container 182 is illustrated which is dimensioned to fit within the aperture 168 defined in the rear wall 142 by the support flaps 164 such that the ancillary item container 182 is positioned flush with the exterior surface of the rear wall 142 . The ancillary item container 182 is formed similarly to the outer container 104 including a front wall 184 , a rear wall 186 , a pair of sidewalls 188 and 190 , as well as a bottom wall 192 and a top wall 194 . One or both of the top wall 194 or bottom wall 192 includes a locking tab 196 or other suitable engaging structure to enable the top wall 194 and/or bottom wall 192 to be releasably held in a closed position over the interior 198 of the ancillary item container 182 . The ancillary item container 182 has an interior 198 defined to adequately secure and retain a number of ancillary items 510 and 520 therein that are to be utilized with the primary item 500 held within the tray member 132 . One or more ancillary items 510 and 520 can be held within the ancillary item container 182 . The interior 198 of the ancillary item container 182 optionally includes a separating member 200 that separates the interior 198 of the container 182 into sections 202 and 204 adapted to receive and retain ancillary items 510 and 520 of varying sizes therein. Additionally, the ancillary item container 182 , by virtue of it being disposed in an easily viewable position within the supporting structure 134 of the inner container 104 , is preferably formed at least partially of a transparent material. This allows the ancillary items 510 and 520 held within the container 182 to be easily viewed by a consumer through both of the outer container 104 and the ancillary item container 182 . This enables a consumer to determine if the ancillary items 510 and 520 held within the ancillary container 182 are damaged in any manner, as well as to view the ancillary items 510 and 520 in their proper orientation for use with the primary item 500 .
[0041] Further, because the ancillary item container 182 is held within the inner container 102 along with the primary item 500 , when the package 100 is opened to remove the inner container 102 from the outer container 104 , both the primary item 500 and the ancillary items 510 and 520 are retained on the inner container 102 such that the primary item 500 and ancillary items 510 and 520 do not become displaced from one another.
[0042] In the above description, each part of the inner container 102 , outer container 104 or ancillary container 182 that is described as being integrally and foldably attached to another component can be connected to the other component by a fold line as is known in the art, or by a perforation line, or in any other suitable manner, in order to enable the various components to remain attached to one another, even when folded from a generally flat configuration into the various container constructions 102 , 104 and 182 described above. The various components for the containers 102 , 104 and 182 can also be separately formed from one another and secured to each other in a foldable manner, such as by utilizing an adhesive or other suitable securing means.
[0043] Alternatively to the previously described embodiments for the package 100 , it is also contemplated that the outer container 104 can be formed to enclose only the primary item 500 . In this embodiment, the outer container 104 enclosing the primary item 500 would be inserted and retained within the tray member 132 of the inner container 102 using any suitable means, such as an adhesive or a mechanical fastener, such that the inner container 102 and the exposed portion of the outer container 104 would each form a part of the outer portion of the package 100 .
[0044] Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept.
[0045] Moreover, the individual components need not be formed in the disclosed shapes, or assembled in the disclosed configuration, but could be provided in virtually any shape, and assembled in virtually any configuration. Further, although various parts described herein are physically separate modules, it will be manifest that they may be integrated into the apparatus with which they are associated. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive.
[0046] It is intended that the appended claims cover all such additions, modifications and rearrangements. Expedient embodiments of the present invention are differentiated by the appended claims.
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The present invention is a package for retaining both a primary item and one or more ancillary items to be utilized with the primary item therein. The package includes an inner container disposed within an outer container that has first and second compartments therein within which the primary item and ancillary items can be positioned. Positioning both the primary item and ancillary items in a single inner container within the package maintains the items together while of the package is being opened, to prevent the misplacement of the ancillary items. Additionally, the primary and ancillary items are positioned on the inner container in a manner which allows for easy viewing both each item on the inner container through one or more transparent portions of the outer container, inner container and ancillary item container.
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RELATED APPLICATIONS
[0001] This application claims the filing date of U.S. provisional application Ser. No. 60/980,598 filed Oct. 17, 2007, the disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates generally to apparatus for removing obstructions from a toilet bowl drain pipe and, more particularly, to toilet bowl plungers.
BACKGROUND OF THE INVENTION
[0003] The use of toilet bowl plungers for removing obstructions from toilet bowl drain pipes is well known. A toilet bowl plunger is typically used when the trap becomes obstructed with waste matter, including fecal matter. The obstruction prevents water and other matter from being flushed from the toilet bowl into the sewage system.
[0004] A typical toilet bowl plunger comprises an elongated handle and an inverted cup-shaped plunger portion connected to an end of the handle. The plunger portion is formed of rubber or some equivalent resilient material. When the trap becomes obstructed, the open end of the plunger portion is placed over the opening at the bottom of the bowl and the walls of the plunger portion collapsed in response to a downward push on the handle thereby forcing air under pressure into the trap. The plunger portion is then returned to it's initial shape pulling upwardly on the handle thereby applying suction to the trap. The resulting agitation tends to dislodge and free the obstruction from the trap.
[0005] A drawback to the use of conventional toilet bowl plungers is that during the process of dislodging the obstruction from the toilet trap, the plunger portion of the plunger comes into contact with unsanitary waste material. After flushing the toilet, the plunger portion can be rinsed in the clean water which fills the bowl. However, simply rinsing the plunger portion with water in the toilet bowl, or elsewhere, is not sufficient to disinfect the plunger portion which has been in direct contact with human waste material. Disinfecting the plunger portion by simply applying a disinfectant from a separate bottle onto the surfaces of the plunger portion can be time consuming and messy.
SUMMARY OF THE INVENTION
[0006] Accordingly, one object of the present invention is to provide a new and improved toilet plunger.
[0007] Another object of the present invention is to provide a new and improved toilet plunger having self-contained apparatus for dispensing disinfecting fluid.
[0008] Still another object of the present invention is to provide a new and improved toilet bowl plunger including a self-contained reservoir for containing a disinfectant fluid and a self-contained fluid dispensing mechanism for dispensing disinfectant fluid from the self-contained reservoir.
[0009] Yet another object of the present invention is to provide a new and improved toilet plunger which can be cleaned and disinfected within the confines of the toilet bowl area.
[0010] Briefly, in accordance with the invention, these and other objects are attained by providing a plunger comprising a plunger handle having first and second end regions and an inverted cup-shaped plunger portion connected to the second end region of the plunger handle. A fluid reservoir is associated with the plunger handle for containing a disinfectant fluid or the like. A fluid dispensing mechanism is associated with at least one of said plunger handle and plunger portion for dispensing the disinfectant fluid from the reservoir upon actuation by a user.
[0011] In one embodiment, the fluid reservoir is situated in the plunger handle and the fluid dispensing mechanism includes an activating part associated with the plunger handle and a fluid dispensing part at the second end region of the handle through which disinfectant fluid is dispensed into the open space defined by the inner concave side of the inverted cup-shaped plunger portion upon activation of the activating part.
[0012] In use, after the plunger has been used in a conventional manner to dislodge an obstruction in the trap of a toilet, the toilet is flushed to fill the bowl with clean water. The plunger is then held over the bowl with the plunger portion situated over the water in the bowl whereupon the user activates the activating part to dispense disinfecting fluid into the water of the bowl through the dispensing part. The disinfectant is concentrated so that when it is mixed with the water in the bowl, a disinfecting solution is formulated which is effective to disinfect the surface of the plunger portion. The plunger portion is submerged into the newly formed disinfectant solution in the bowl and agitated thereby causing the disinfectant mixture to flow over all of the surfaces of the plunger portion to effectively disinfect the same.
[0013] The invention thus provides a convenient arrangement by which the plunger portion of a plunger can be disinfected within the confines of the area of the toilet bowls without having to fill a bucket with a disinfecting solution or to obtain a separate container of disinfectant and apply the disinfectant directly to the plunger portion either of which can be time consuming and messy. The toilet bowl itself becomes a tank for containing a disinfectant mixture and is sufficiently deep that the entire plunger portion can be immersed in the disinfecting solution.
[0014] According to another embodiment of the invention, the fluid dispensing part can be designed to dispense disinfectant fluid directly onto the inner surface of the plunger portion upon activation of the activating part. In this embodiment, the user activates the activating device to dispense disinfecting fluid directly onto the inner surface of the plunger portion from which it can be wiped using ordinary paper towels or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A more complete appreciation of the present invention and many of the attendant advantages thereof, will be readily understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0016] FIG. 1 is a perspective view of a toilet bowl plunger in accordance with an embodiment of the present invention;
[0017] FIG. 2 is a front elevation view, in section, of a first end region of a plunger handle and an activating part of a fluid dispensing mechanism of a toilet bowl plunger in accordance with the illustrated embodiment;
[0018] FIG. 3 is an exploded perspective view of the components of the activating part of the fluid dispensing mechanism;
[0019] FIG. 4 is a front elevation view, in section, of a second end region of the plunger handle of the illustrated embodiment of the invention to which a plunger portion is connected, and showing a fluid dispensing part of the fluid dispensing mechanism; and
[0020] FIG. 5 is an exploded perspective view of the components of the fluid dispensing part of the fluid dispensing mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 , an embodiment of a toilet bowl plunger 10 in accordance with the invention includes a plunger handle 12 having first and second end regions 12 a and 12 b and an inverted cup-shaped plunger portion 14 connected to the second end region 12 b of plunger handle 12 . An activating handle 16 is coupled to the first end region 12 a of the plunger handle 12 and comprises a component of the activating part of a fluid dispensing mechanism described below. The plunger portion 14 comprises an inverted cup-shaped member formed of rubber. Other suitable flexible materials may be used. An opening 18 ( FIG. 4 ) is formed through the apex of plunger portion 14 which is surrounded by an internally threaded collar 20 integral with plunger portion 14 , and an externally threaded portion of the second end region 12 b of plunger handle 12 extends through the opening 18 and is threaded within collar 20 and is thereby connected to the plunger portion 14 .
[0022] Turning to FIGS. 2 and 4 , the plunger handle 12 comprises a tubular member formed of aluminum. Other metallic or plastic materials may be used, such as aluminum composites, rubber composites, polyurethane, acrylics and the like, so long as the material is rigid. In the illustrated embodiment the plunger handle 12 should be non-porous since a hollow interior portion of plunger handle 12 functions as a reservoir 22 for disinfectant fluid 24 . For example, the hollow interior of the plunger handle 12 is filled with a suitable disinfectant fluid, such as chlorine bleach (sodium hypochlorite). An activating part 26 ( FIG. 2 ) of a mechanism for dispensing the disinfectant fluid from the reservoir 22 is associated with the plunger handle 12 at its first end region 12 a , while a dispensing part 42 ( FIG. 4 ) of the disinfectant fluid dispensing mechanism is associated with the plunger handle 12 at its second end region 12 b . The activating and dispensing parts 26 , 42 each comprise a one-way valve situated at a respective end of the plunger handle 12 to trap disinfectant fluid in the reservoir 22 . The dispensing part 42 utilizes a spring to control the compressive force acting on a gate to close the gate as described below. Where chlorine bleach is used as the disinfecting fluid, the amount dispensed should be adjusted based on the quantity of water in the bowl such that, preferably, about a 5% solution is achieved.
[0023] Referring to FIGS. 2 and 3 , activating part 26 comprises a valve housing 28 affixed, such as by glue, to the end of the first end region 12 a of plunger handle 12 , a valve gate 30 slidably mounted in a lower chamber of valve housing 28 , a spring 32 mounted in an upper chamber of valve housing 28 , a toggle lock 34 having a keyway shaped opening 35 , a washer 26 and an activating handle 16 . A screw 38 is threaded upwardly through a threaded bore in the gate 30 , and passes through the valve housing 28 , spring 32 , toggle lock 34 and washer 36 and is then threadedly connected to an axially extending internally threaded bushing 40 in activating handle 16 . The activating part 26 functions as an upper seal to prevent the disinfectant fluid from escaping from reservoir 22 . The spring 32 normally urges the activating handle 16 via washer 36 upwardly which urges the screw 38 and gate 30 upwardly to close the valve. The toggle lock is slidable back-and-forth in a lateral direction through slots 39 formed at opposite sides of activating handle 16 . If the toggle lock 34 is in its unlocked position as seen in FIG. 2 moving the activating handle 16 in a downward direction moves the gate 30 downwardly thereby allowing air to enter the top of the reservoir. When in its unlocked position, the enlarged portion of the keyway opening is situated below the washer so as not to present an obstacle to the movement of the activating handle. When in its locked position, the reduced portion of the keyway opening is situated beneath the washer, which is larger than the reduced portion of the keyway opening and prevents downward movement of the activating handle. When the toggle lock 34 is in its unlocked position and the activating handle 16 is moved downwardly, the force of the fluid moving in the downward direction is sufficient to overcome the force of the spring in the lower dispensing part 42 of the fluid dispensing mechanism so that gate 30 moves downwardly opening the valve.
[0024] Referring to FIGS. 4 and 5 , the dispensing part 42 comprises a valve housing 44 affixed, such as by glue, to the end of the second end region 12 b of plunger handle 12 , a valve gate 46 slidably mounted in a lower chamber of valve housing 44 , a spring 48 mounted in an upper chamber of valve housing 44 , and a washer 50 . A screw 52 passes downwardly through openings in the washer 50 , spring 48 and valve housing 44 and is threadedly connected to gate 46 . Spring 48 normally urges the washer 50 upwardly which in turn urges the screw 52 and gate 46 upwardly to close the valve.
[0025] When the activating handle is moved downwardly, the force of the fluid moving in the downward direction overcomes the resistance of spring 48 and allows gate 46 to open to dispense the disinfectant. The force of the downwardly moving fluid overcomes the spring force in the lower fluid dispensing part 42 thereby allowing disinfectant fluid to be dispensed from the second end of the plunger handle 12 into the space defined by the concave inner surface of plunger portion 14 .
[0026] In use, after the toilet bowl plunger 10 has been employed in a conventional manner to dislodge an obstruction in the trap of a toilet, the toilet is flushed to fill the bowl with clean water. While holding the plunger 10 so that the plunger portion is situated over the water in the bowl, the user slides the activating handle downwardly to dispense disinfecting fluid into the water in the bowl. The disinfectant mixes with the water to form a disinfecting solution which is effective to disinfect the surface of the plunger portion. The plunger portion is submerged into the disinfectant solution in the bowl and agitated to cause the disinfectant mixture to flow over the surfaces of the plunger portion to disinfect the same.
[0027] The upper activating part 26 can be adjusted to increase or reduce the amount of disinfecting fluid dispensed with each downward movement of activating handle 16 over the plunger handle 12 . This is accomplished by rotating the activating handle 16 to raise or lower the handle 16 on screw 38 . Rotating the handle 16 to further compress spring 32 reduces the amount of fluid dispensed through the lower dispensing part 42 , and vice versa.
[0028] Other arrangements are possible. For example, the reservoir for disinfecting fluid may take the form of a separate cylinder attached to the exterior of the plunger handle and fluidly coupled to the dispensing part of an external rubber tube. An electric pump can be activated by pushing a button to pump the disinfecting fluid from the reservoir through the dispensing part. Alternatively, only a portion of the plunger handle may be hollow and function as the disinfecting fluid reservoir. Other one-way valve constructions may be utilized for the activating and fluid dispensing parts, such as ball valves.
[0029] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the claims appended hereto, the invention may be practiced otherwise then as specifically disclosed herein.
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A toilet bowl plunger includes a fluid reservoir for containing a disinfectant fluid and a fluid dispensing mechanism for dispensing the disinfectant fluid from the reservoir out from the toilet bowl plunger upon activation by a user.
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TECHNICAL FIELD
The invention relates to a drag head for dredging purposes and to a trailing suction hopper dredger comprising such a head. The invention further relates to methods of dredging.
BACKGROUND
Dredging at sea or in open water may be carried out by dredging vessels, such as a trailing suction hopper dredger (TSHD). The dredging vessels comprise a suction tube one end of which can be lowered to the seabed and used to suck up solids such as sand, sludge or sediment, mixed with water. This lower end of the suction tube can be provided with a suction head. The solid material mixed with water is pumped through the suction tube into a hopper of the dredging vessel.
Once the hopper is full, the pumping may continue causing an overflow. The overflow will mainly be formed by water, as the solids tend to sink to the bottom of the hopper. The pumping may be stopped when it is no longer efficient to continue, as may be the case when the overflow is becoming too dense.
The higher the density of the mixture of solids and water that is pumped through the suction tube, the more efficient the dredging is performed. Dredging with relatively high densities has many advantages. In the first place, dredging can be performed in a more time and cost efficient way. Secondly, more solid material can be pumped into the hopper. Also, overflow losses will be reduced or will even disappear which is advantageous from an energetic point of view. Furthermore, reducing overflow losses will reduce turbidity.
One element of the dredging installation that may limit the maximum density is the trailing suction head provided at the lower end of the suction tube.
DE214643C discloses a suction tube and a trailing suction head. The suction tube has a bend near the trailing suction head such that the suction opening faces the direction of motion. In the suction opening an adjustable sled member is provided to control the dredging depth. Also, an adjustable plate member may be provided in the suction opening to control the amount of water entering the suction opening. A dragging force is applied directly to the suction head by the suction tube.
Other trailing suction heads are known which comprise a body which is arranged to be dragged along the seabed. The body comprises connection means for connecting to a suction tube which may also serve to impart the drag force on the body. A visor having a cutting edge is hingeably connected at a rear side of the body. The angle of orientation and/or the depth of the cutting edge of the visor can be adjusted with respect to the body by means of hydraulic piston/cylinder devices. Jet nozzles are provided in the body to facilitate the dredging process by breaking up the material of the sea bed and fluidizing it for removal via the suction tube. In order to lift the dredged material from the cutting edge towards the inlet to the suction tube, a significant amount of mixing with water is required leading to a reduction in density of the mixture. At present for sand and silt dredging, mixture densities of on average 1350 kg/m 3 are achievable. A drag head of this type is known from EP1653009A1. Similar drag heads are known from EP1108819A1 and AU2005200784A1, the contents of each of which are herein incorporated by reference in their entirety.
It would be desirable to provide an alternative to the above discussed drag heads, in particular one which is capable of sucking up mixtures of water and material with a relatively high density in a relatively efficient way whereby excess water transport is minimised.
SUMMARY
According to the invention, there is provided a drag head for dredging material from a bed of a body of water and transporting the material to a suction tube, the drag head being arranged to be dragged over the bed in a dragging direction by a drag member, wherein the drag head comprises a heel section being connectable to the drag member and having a bed engaging surface arranged to follow the bed and a suction section comprising a suction opening; a suction chamber; and an outlet for connection to the suction tube such that an underpressure can be created in the suction chamber to suck up the material from the bed through the suction opening into the suction chamber, wherein the suction section is adjustably mounted to the heel section such that an orientation of the suction opening can be adjusted relative to the heel section. By providing the suction section separately adjustable from the heel section, the orientation of the suction opening can be set independently of the position of the heel which is being towed along the bottom of the seabed. Such an arrangement is believed to be considerably more versatile in optimizing the direction and/or height of the suction opening. Since the outlet also forms part of the suction section, its orientation may also be adjusted together with the suction opening. In the present context, reference to material is intended to refer to solid or semi solid material including silt, sand, sediment, mud, gravel and fractured rock as may generally be encountered during suction dredging operations. Furthermore, although reference may be made to sea bed, this is equally intended to cover and include beds of rivers, lakes, canals, estuaries and the like.
According to the invention the heel section is arranged to be connected to a drag member. The drag member may be a dragging pole, bar, pipe, cable, chain or the like or the suction tube itself, which is connected with the vessel to drag the drag head over the seabed. In the present context, reference to the fact that the heel section is connected to the drag member is understood to mean direct or indirect connection therewith. The dragging force is subsequently applied to the suction section via the heel section. Preferably, the suction section is not connected to the drag member except via the heel section.
The suction section may be adjustable in various ways using appropriate mechanical means as will be known to the skilled person. According to a preferred embodiment of the invention, the suction section is rotatable with respect to the heel section about an axis of rotation which is in use substantially horizontal and perpendicular to the dragging direction. Most preferably, this axis lies generally behind the heel section and ahead of the suction section with respect to the direction of movement of the drag head. Preferably too, the axis is positioned relatively low with respect to the bed engaging surface in order to maximize the mass of the suction section that acts downwards.
According to a further aspect of the invention, the suction section may comprise a lower edge, e.g. a cutting edge, forming a trailing edge of the suction opening, wherein the lower edge or cutting edge is in use lower than the bed engaging surface of the heel section in order to dig into the material forming the bed. The lower edge or cutting edge is preferably substantially horizontal and substantially perpendicular with respect to the dragging direction and points at least partially in the dragging direction. By providing the lower edge or cutting edge below the bed engaging surface of the heel section, the suction opening will be directed in the dragging direction. By rotating the suction section with respect to the heel section the relative depth of the lower edge or cutting edge with respect to the bed engaging surface of the heel section can be adjusted and thereby the depth of channel dredged by the drag head.
The cutting edge may comprise a row of cutting members, which may be formed as (replaceable) teeth being placed in corresponding teeth holders. In general, the width of the cutting edge transverse to the dragging direction may be any appropriate width according to the operation being performed. Nevertheless, in general, the width of the cutting edge will not be more than the width of the bed engaging surface of the heel section. In a most preferred embodiment, both of these sections may have similar widths. It will also be understood that although in general the heel section will lie ahead of the suction section in the direction of movement, this position is not necessarily essential. The heel section may in certain configurations be located to one or both sides or around the suction section.
According to one embodiment of the invention, the width of the suction section decreases from the suction opening towards the outlet, most preferably in a gradual way. This smooth transition assists the transport of the dredged material towards the outlet and helps avoid significant energy losses. Preferably, the suction chamber may have a tapered or trumpet like shape to provide a smooth transition between the relatively large suction opening and the smaller outlet towards the suction tube. The term width is used here to indicate the dimension substantially perpendicular to the dragging direction and, in use, substantially horizontal. As an additional or alternative measure, the suction section may have a bottom plate which is at least partially inclined in an upward direction from the lower edge or cutting edge towards the outlet. The bottom plate ensures a smooth flow path for the material that is sucked up, thereby reducing the resistance. The bottom plate may be straight or curved.
According to an embodiment the suction section may be connected to the suction tube via a flexible connection. Providing a flexible connection has the advantage that the suction section can be moved with respect to the heel section and the suction tube. The suction tube may be provided on and move with the heel section or may be independent therefrom. The flexible connection may be provided by a flexible reinforced tube or concertina section. Alternatively it may be achieved by telescoping sections of rigid pipe. Preferably, the flexible section is of low-loss design in order to further reduce flow resistance to the dredged mixture, whereby transport of higher mixture densities may be achieved. In a further alternative, the suction tube itself may be flexible.
In one embodiment, the suction opening is at least partially bounded by the heel section. In such a configuration, the suction section and heel section may engage together to form the suction chamber. The engagement between the two sections should be sufficiently tight that suction losses and water inflow from between the two sections may be minimal. In a particularly preferred embodiment, the heel section and the suction section comprise two half shells that engage or telescope together to form the suction chamber. The heel section provides the bed engaging surface while the suction section carries the lower edge or cutting edge and forms the suction outlet.
The drag head may be provided with means to form a desired mixture density of the dredged material, optimized to achieve transport to the surface with minimal liquid content. The skilled person will be aware of various manners in which this may be achieved using swirl vanes, cutting blades and the like. According to a preferred embodiment the drag head may comprise a plurality of conduits having outlet openings or nozzles for delivering water jets into the suction chamber at or near the outlet. These nozzles may preferably be located on the suction section and most preferably around the outlet. Such water jets may be provided to fluidize the material to make transport of the material easier.
According to a further embodiment, the drag head may be provided with means for breaking up or loosening the material of the sea bed at or ahead of the lower edge or cutting edge. In this case too, the choice of measure provided will depend on the particular material being dredged and the skilled person will be aware of the alternatives that may be used. In a preferred embodiment, a plurality of conduits having outlet openings for forming water jets beneath the bed engaging surface of the heel may be provided. Not only do such jets make it easier to remove the material from the bottom but they may also assist in fluidizing it to the desired degree for further transport.
According to an embodiment the outlet from the suction chamber is at least partially directed in a direction opposite to the dragging direction. By orientating the outlet from the suction section in this way, the material is initially sucked in a direction at least partially opposite to the dragging direction. This may assist in providing a natural and undisturbed flow path for the material, allowing for an energy efficient suction operation.
According to a still further aspect of the invention, the drag head may be provided with an actuator arrangement for displacing the suction section with respect to the heel section. This actuator may be a hydraulic, pneumatic or mechanical actuator and can be automatically operated to set a desired orientation or depth of the suction section or the cutting edge.
In an alternative arrangement, the desired orientation may be achieved without actuator by using the natural mass of the suction section. This may be weighted or biased with respect to the heel section to achieve the desired orientation. In one embodiment, the position of the hinge may be adjustable to achieve the desired weighting. In this manner the depth of the lower edge or cutting edge may be adjusted depending e.g. on the dragging speed, seabed consistency and other related factors.
According to a further aspect of the invention, the heel section may be provided with a pump to provide suction to the suction chamber via the suction tube. Preferably the pump is a high performance submerged dredge pump for operating with high mixture densities such as a centrifugal pump. The pump may be carried directly on the heel section and may carry the suction tube. Alternatively, the pump and/or the suction tube may be provided at a remote position or may be mounted to the drag member.
Preferably the pump is located at a suitable distance above the seabed to avoid damage and for most purposes will be located at about half the water depth in order to most efficiently assist in transport of the mixture.
The invention also relates to a vessel, such as a trailing suction hopper dredger, comprising a drag head as generally described above. In its working configuration, the heel section is attached to a drag member trailing from the vessel whereby the drag head may be dragged or towed along the seabed.
The invention further relates to a method of suction dredging a mixture of solids and water from the bed of a body of water using a drag head comprising a heel section and a suction section, the method comprising dragging the heel section across the bed in a first direction, positioning the suction section at a desired depth and angle with respect to the heel section such that the suction section at least partially engages and enters the bed, applying suction to the suction section to cause the bed material to be sucked up in a direction at least partially opposed to the first direction and be mixed with water and transporting the mixture to the surface.
Most preferably, the method is carried out for a mixture comprising sand and water having a density of more than 1650 kg/m 3 . As a result of the desirable drag head configuration, such densities may be efficiently dredged.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:
FIG. 1 schematically shows a side view of a first embodiment of the invention;
FIG. 2 schematically shows a side view of a second embodiment of the invention;
FIG. 3 schematically shows a top view of the embodiment of FIG. 2 ; and
FIG. 4 schematically shows a cross-sectional view taken at line 4 - 4 in FIG. 3 .
The figures are meant for illustrative purposes only, and shall not serve as restriction of the scope or the protection as laid down by the claims.
DETAILED DESCRIPTION
With reference to the figures, embodiments will now be described in more detail. According to FIG. 1 , there is shown a schematic side view of a drag head 1 according to a first embodiment of the invention being used to dredge sand 2 or other similar material from the seabed 3 and transport it to a vessel 4 .
Drag head 1 comprises a heel section 11 in the form of a sled and a suction section 10 having the form of a bucket, articulated together at a generally horizontal hinge 8 . The heel section 11 is attached to a cable 16 via a pair of mounts 18 of which only one is shown. The cable 16 extends to the vessel 4 where it is held fast by a suitable derrick or boom 19 as is conventional in the art.
The heel section 11 has a bed engaging surface 22 on its underside. The bed engaging surface 22 is sufficiently long to ensure that the heel section assumes a substantially stable towing position. On its upper surface, heel section 11 carries a suction pump 50 which has a pump outlet 52 connected to a transport tube 54 leading to the surface and into a hopper 5 onboard the vessel 4 .
The suction section 10 has a suction chamber 12 within its interior with a suction opening 13 at its lower side. A trailing edge or lower edge of the suction opening 13 forms a cutting edge 15 . The cutting edge 15 may be provided with serrations (not shown). From the cutting edge 15 a bottom plate 17 leads up to an outlet 14 provided at an upper, rear side of the suction section 10 . The outlet 14 connects the interior of the suction chamber 12 to a flexible suction tube 20 . The suction tube 20 is connected to a pump inlet 51 on pump 50 .
In use, the drag head 1 is dragged along the seabed 3 by the cable 16 in a direction of motion D. The heel section 11 follows the seabed 3 and the blades 24 on the bed engaging surface 22 cut into the sand 2 and loosen it. The suction section 10 pivots about the hinge 8 due to its mass and causes the cutting edge 15 to dig into the sea bed 3 . The loosened sand 2 is scooped up by the cutting edge and rides up the bottom plate 17 towards the outlet 14 . The pump 50 is operated to generate suction in the suction tube 20 causing water to also be sucked up through the suction opening 113 . As the water and cut sand 2 approach the outlet 14 , the narrowing of the suction chamber 13 causes their velocity to increase whereby the sand 2 becomes entrained with the water. The resulting mixture is pumped via the pump 50 and transport tube 54 to the surface and into the hopper 5 . Due to the advantageous orientation of the suction opening 13 and the upward slope of the bottom plate 17 towards the outlet 14 , the cut sand can be carried away with relatively little entrainment of water and a relatively high density of the mixture.
A second embodiment of a drag head 100 according to the invention is shown in FIG. 2 in which like elements are provided with similar reference numerals preceded by 100 . FIG. 2 shows a heel section 111 and a suction section 110 which are hinged together at a hinge 108 forming a suction chamber 112 therebetween. The suction section 110 is slightly narrower than the heel section 111 , whereby both sections can partially telescope into each other by rotation about the hinge 108 . A lowermost or trailing edge of the suction section 110 is provided with a cutting edge 115 . The heel section 111 has a lowermost bed engaging surface 122 . Between the cutting edge 115 and the rear edge of the bed engaging surface 122 there is formed a suction opening 113 providing access to the suction chamber 112 .
In the embodiment of FIG. 2 , the heel section 111 further comprises a tubular body 140 rigidly attached to a front surface thereof. The tubular body 140 is in turn connected to a drag member 141 which is towed from the vessel 4 as in FIG. 1 . The drag member 141 and the tubular body 140 form a relatively rigid arm extending to the surface (although it will be understood that powered joints may be foreseen) which ensures that the angle of the heel section 111 with respect to the seabed remains substantially constant (for a given depth of water).
On an upper surface of the tubular body 140 there are provided a pair of actuators 130 (of which one is shown in this view) having piston arms 132 attached to an upper portion of the suction section 110 at a mount 134 . By operating the actuators 130 , the suction section 110 can be pivoted with respect to the heel section 111 to cause the cutting edge 115 to dig deeper into the sea bed.
As in the first embodiment, the suction section has a bottom plate 117 which leads upwards to an outlet 114 at an upper rear part of the suction section. Unlike the first embodiment, the outlet 114 is connected to a flexible connection 121 which in turn connects to the suction tube 120 . In this case, the pump 150 is carried by the drag member 141 and has a pump inlet 151 connected to the suction tube 120 and a pump outlet 152 connected to transport tube 154 .
FIG. 3 shows a plan view of the embodiment of FIG. 2 showing heel section 111 and suction section 110 engaging each other with actuators 130 determining the degree of rotation of the sections about hinge 108 . According to FIG. 3 , it can be seen that the heel section 111 and the suction section 110 have a maximum width W 1 at the position of the cutting edge. From this position, the width of the suction section 110 decreases to a width W 2 at the outlet 114 .
FIG. 4 is a sectional view taken on line 4 - 4 in FIG. 3 showing an interior of the suction chamber 112 . In this view, nozzles 160 can be seen located around outlet 114 . The nozzles 160 are connected to a suitable source of pressure (not shown) and are operated to generate pressurized jets of water within the outlet 114 directed towards the flexible connection 121 . Also visible in FIG. 4 are further nozzles 162 provided in the bed engaging surface 122 of the heel section 111 . The further nozzles 162 are in communication with a pressure manifold 164 within the heel section 111 into which pressurized water may be supplied from the source of pressure mentioned above.
In use, the drag head 100 is dragged along by the dredging vessel in the direction D with the heel section 111 engaging the seabed 3 . Pressurised water is provided to the manifold 164 which causes the formation of jets of water from further nozzles 162 beneath the bed engaging surface 122 . The jets of water loosen and partially break up the sand or silt 2 . The loosened sand 2 is cut and lifted by cutting edge 115 and enters suction chamber 112 through suction opening 113 . The reducing width of the suction chamber 112 and the bottom plate 117 funnel the sand 2 upwards towards the outlet 114 . At this stage, the sand contains a quantity of entrained water due to the further nozzles 162 . Nevertheless, the density is too high for it to be easily transported. As the sand and water mixture enters the outlet 114 additional water jets are injected through nozzles 160 . These jets further loosen the sand 2 and fluidise it to a desired final density of around 1650 kg/m 3 for transport via the pump 150 and transport tube 154 to the surface. Due to the increased density, the vessel 4 can be filled without overflow or further discharge back into the water which is highly advantageous for sensitive environments where such discharge during dredging is prohibited.
Thus, the invention has been described by reference to certain embodiments discussed above. It will be recognized that these embodiments are susceptible to various modifications and alternative forms well known to those of skill in the art. In particular, the arrangement of flexible connection of FIG. 2 may be replaced by a telescoping arrangement. Furthermore, the actual design may be distinct from the schematically illustrated designs.
Many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.
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A drag head ( 100 ) for dredging material ( 2 ) from the bed ( 3 ) of a body of water and transporting the material ( 2 ) to a suction tube ( 120 ). The drag head ( 100 ) is arranged to be dragged over the bed ( 3 ) in a dragging direction (D). The drag head ( 100 ) includes a suction section ( 110 ) in which an under pressure can be created to suck up the material ( 2 ) from the bed ( 3 ) through a suction opening ( 113 ) into a suction chamber ( 112 ). A heel section ( 111 ) guides the drag head ( 100 ) along the bed ( 3 ). The suction section ( 110 ) is preferably rotatably connected to the heel section ( 111 ). The suction section ( 110 ) also includes an outlet ( 114 ) for transporting the material ( 2 ) towards the suction tube ( 120 ).
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BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to managing storage resources on a computer network.
2. Description of the Related Art
For managing storage resources on a computer network, conventionally used addresses locating the storage resources on the network and host computers that use the storage resources have a specific format depending on the type of an interface embodying the network for connecting the host computers and the storage resources. For example, if the interface of the computer network is fiber channels, the address of a host computer is identified by a World Wide Name (WWN) that is unique to the port of the host computer. If the interface is a network running Internet Protocol (IP), the address of a host computer is identified by a Media Access Control (MAC) address that is unique to the network card of the host computer. As an example of prior art of managing such resources using the WWN and MAC addressing, operation of setting a host computer having access rights to a logical volume provided by an on-line storage system will be illustrated below. For example, when a resources manager is allocating a logical volume provided by the storage system to a host computer in connection environment using fiber channels, it sets a port of the storage system for the entry of access requests for the logical volume, gets the WWN of the port of the host computer and the WWN of the above port of the storage system, and registers the mapping between the two WWNs on a switch on the computer network, thus completing the above setting.
Japanese Patent Laid-open No. 2001-249769 describes an on-line storage system whose logical volumes can be mapped to the address of a host computer. The technique described in this publication makes it possible to control access rights to the logical volumes as such by using the WWN of a host computer.
In the foregoing previous techniques for on-line resources management, storage systems and host computers are assigned addresses in a specific format depending on the type of a computer network interface connecting the storage systems and host computers. Therefore, it is necessary to use different address schemes for different types of interfaces. As described in the example of setting a host computer having access rights to a logical volume, some previous technique makes the control of the storage resources themselves possible, whereas some previous technique enables only the control of the entry to the storage resources for access thereto, according to the type of storage systems as the storage resources. Consequently, if different types of storage systems as on-line resources exist on a computer network, users need to take notice of different scopes of management for each type of storage systems to manage the resources of the storage systems. This may complicate the management of the resources particularly when many types of storage systems exist on the network. techniques, the challenges to overcome by the present invention are enabling users to manage on-line resources of storage systems on a computer network, independent of the type of the interface embodying the network and the type of the storage systems even when different types of storage systems exist on the network.
SUMMARY OF THE INVENTION
The present invention is a technique for managing storage resources that has overcome the foregoing challenges and problems.
The present invention essentially provides a resources managing program on a computer network having a plurality of storage systems of different types so that the program converts a resources allocation request received across the network into a setup request adapting to the type of the network or the storage systems. Specifically, in one aspect, the invention provides (1) a method for managing resources of storage systems on a network including the step of converting a resources allocation request received across the network into a setup request adapting to the type of the network or the storage systems under the control of a resources managing program, thereby providing compatibility of different modes of addressing the resources according to the type of the network and/or different modes of accessing the resources according to the type of the storage systems. (2) In the foregoing method of (1), if the resources allocation request designates an asset on an Internet Protocol (IP) network, the above step converts it into a setup request including the Media access Control (MAC) address of the asset as an Application Programming Interface (API) parameter; or if the resources allocation request designates an asset on a fiber channel, the above step converts it into a setup request including the World Wide Name (WWN) of the asset as an API parameter. (3) In the foregoing method of (1), the above step includes the step of, under the control of the resources managing program, registering the following entries into a table: for each unit of the resources of the storage systems, its identifier on the networks its address which adapts to the type of the network, and a group identifier which is assigned by grouping the resources into allocation units. The above step further includes the step of allocating resources units making up a group in a lump, according to the group identifier. (4) In the foregoing method of (1), the above step further includes the steps of registering identification and related information for host computers on the network, mapping a host computer or a group of host computers with a group identifier to a resources unit or a group of resources units of the storage systems, and setting the host computer or the group of host computers permitted to access the resources unit or the group of resources units of the storage systems. (5) In the foregoing method of (1), the above step further includes the step of setting information that each host computer has access rights to which resources units of the storage systems on the network equipment or the storage systems. This information is used by the resources managing program as management information. (6) In the foregoing method of (1), the above step further includes the steps of comparing information that each host computer has access rights to which resources units of the storage systems, set on the storage systems or the network equipment, with the management information held by the resources managing program, and changing discrepancy, if exists, to the setting in accordance with the management information held by the resources managing program. (7) In the foregoing method of (1), the above step further includes the steps of, when a program other than the resources managing program changes the setting on the storage systems or the network equipment, receiving notification of setting change from the storage systems or the network equipment, comparing the setting change with the management information held by the resources managing program, and changing discrepancy, if exists, to the setting in accordance with the management information held by the resources managing program. (8) In the foregoing method of (1), the above step further includes the steps of, under the control of the resources managing program, adding network interface type information to the address of each host computer to which the resources of the storage systems are allocable and storing the network interface type information as a part of management object information that the resources managing program holds for management, wherein the above step converts the received resources allocation request into a setup request adapting to the type of the interface. In another aspect, the invention provides (9) a computer program for managing resources of storage systems on a network, the computer program comprising computer readable program code means causing a computer to perform the step of converting a resources allocation request received across the network into a setup request for network equipment that exerts control of the network or the storage systems so that the setup request adapts to the type of the network or the storage systems, thereby providing compatibility of different modes of addressing the resources according to the type of the network and/or different modes of accessing the resources according to the type of the storage systems. (10) In the foregoing computer program of (9), if the resources allocation request designates an asset on an IP network, the above step converts it into a setup request including the MAC address of the asset as an API parameter; or if the resources allocation request designates an asset on a fiber channel, the above step converts it into a setup request including the WWN of the asset as an API parameter. (11) In the foregoing computer program of (9), the above step includes the step of registering the following entries into a table: for each unit of the resources of the storage systems, its identifier on the network, its address which adapts to the type of the network, and a group identifier which is assigned by grouping the resources into allocation units. The above step further includes the step of allocating resources units making up a group in a lump, according to the group identifier. (12) In the foregoing computer program of (9), the above step further includes the steps of registering identification and related information for host computers on the network, mapping a host computer or a group of host computers with a group identifier to a resources unit or a group of resources units of the storage systems, and setting the host computer or the group of host computers permitted to access the resources unit or the group of resources units of the storage systems. (13) In the foregoing computer program of (9), the above step further includes the step of setting information that each host computer has access rights to which resources units of the storage systems on the network equipment or the storage systems. This information is used by the computer program as management information. (14) In the foregoing computer program of (9), the above step further includes the steps of comparing information that each host computer has access rights to which resources units of the storage systems, set on the storage systems or the network equipment, with the management information held by the computer program, and changing discrepancy, if exists, to the setting in accordance with the management information held by the computer program. (15) In the foregoing computer program of (9), the above step further includes the steps of, when another program changes the setting on the storage systems or the network equipment, receiving notification of setting change from the storage systems or the network equipment, comparing the setting change with the management information held by the computer program, and changing discrepancy, if exists, to the setting in accordance with the management information held by the computer program. (16) The foregoing computer program of (9) is stored into a dedicated hardware chip or a nonvolatile memory as firmware included in the storage systems or the network equipment. In a further aspect, the invention provides (17) a computer readable medium having a computer program for managing resources of storage systems on a network stored thereon. The computer program causes a computer to perform the step of converting a resources allocation request received across the network into a setup request for network equipment that exerts control of the network or the storage systems so that the setup request adapts to the type of the network or the storage systems, thereby providing compatibility of different modes of addressing the resources according to the type of the network and/or different modes of accessing the resources according to the type of the storage systems. In a still further aspect, the invention provides (18) an apparatus for managing storage resources on a network, comprising means for receiving a resources allocation request across the network, means for converting the received resources allocation request into a setup request for network equipment that exerts control of the network or the storage entity under the control of a resources managing program so that the setup request adapts to the type of the network or the storage entity of the storage resources, thereby providing compatibility of different modes of addressing the resources according to the type of the network and/or different modes of accessing the resources according to the type of the storage entity, and means for sending the setup request to the network equipment or the storage entity across the network.
According to the foregoing, even if different type of storage systems exist on a computer system, the resources of the storage systems can be allocated and managed by a common host-to-LV mapping scheme.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an example of a computer network system configured for managing logical volumes on on-line storage.
FIG. 2 is a diagram illustrating an example of a computer network configuration in which a plurality of host computers shares storage systems.
FIG. 3 illustrates an example of contents of a host grouping table if the connection interface is fiber channels.
FIG. 4 illustrates another example of contents of the host grouping table if the connection interface is an IP network.
FIG. 5 illustrates a further example of contents of the host grouping table in a form independent of the connection interface.
FIG. 6 illustrates an example of contents of a logical volume (LV) grouping table in a form independent of the connection interface.
FIG. 7 illustrates an example of contents of a host-to-LV mapping table.
FIG. 8 illustrates an example of a window presented by a resources management utility.
FIG. 9 is a flowchart illustrating an example of a procedure executed by a resource manager.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention now is described fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.
FIG. 1 is a diagram illustrating an example of a computer network system configured for managing logical volumes on on-line storage as storage resources.
In FIG. 1 , a block identified by reference number 1 is a resources manager as a resources managing program for managing the resources of on-line storage; a block identified by reference number 6 is an administrative terminal from which directives are sent to the resource manager 1 ; a block identified by reference number 9 is a storage system in which storage resources to be managed exist; a block identified by reference number 12 is a switch; and a line identified by reference number 8 is an interface for physically connecting the above entities. Through the interface, the resources manager 1 manages the storage system 9 and the switch 12 , for example, remotely updating the setup information for the storage system 9 and the switch 12 . The resource manager 1 comprises a setup request handler 2 which executes resources management of the storage system 9 in response to a request from the higher-level device, a host grouping table 3 in which respective information for host computers that use the storage system is stored, a logical volume (LV) grouping table 4 in which respective information for logical volumes (hereinafter referred to as LVs) as the resources provided by the storage system 9 is stored, and a host-to-LV mapping table 5 in which mapping between the host computers and the LVs accessible to the host computers is stored. The administrative terminal 6 presents a Graphical User Interface (GUI) window to the user and is provided with a resources management utility 7 for accepting a setup request and displaying results of the requested setup execution on the GUI window. The storage system 9 is furnished with an LV allocation table 11 that is a list of the LVs provided by it and the access-permitted host computers associated with the LVs and an LV allocation table manager 10 which updates the contents of the LV allocation table in response to a request from the higher-level device. The switch 12 is furnished with a port mapping table 14 which is referenced in determining what host computer and what storage system belong to a virtual computer network when a computer network comprising a plurality host computers and a plurality of storage systems is divided into a plurality of virtually independent computer networks, according to the information on the assignments of the ports to the host computers and the storage systems. In addition, the switch 12 includes a port mapping table manager which updates the contents of the port mapping table 14 in response to a request from the higher-level device.
In the thus configured system, the administrative terminal user performs setup operation via the GUI window provided by the resources management utility 7 . This enables the user to map a host computer to an LV provided by the storage system in a manner that the operation of the LV allocation table manager 10 of the storage 9 and the port mapping table manager of the switch 12 is transparent to the user and easily if there are different types of storage systems.
FIGS. 2 through 7 are provided to explain mapping between host computers and LVs.
FIG. 2 illustrates an example of a computer network configuration in which storage systems are shared by a plurality of host computers.
In FIG. 2 , blocks identified by reference numbers 15 a , 15 b , and 15 c respectively are host computers; blocks identified by reference numbers 9 a and 9 b respectively are storage systems; entities identified by reference numbers 9 a 0 and 9 a 1 respectively are LVs as storage resources provided by the storage system 9 a ; and entities identified by reference numbers 9 b 0 and 9 b 1 respectively are LVs as storage resources provided by the storage system 9 b . The resources manager 1 is the same as shown in FIG. 1 . Using a case where two host computers 15 a and 15 b are set having access rights to three LVs 9 a 0 , 9 a 1 , and 9 b 0 and one host computer 15 c is set having access rights to one LV 9 b 1 as an example, how to set mapping between the host computers and the LVs will be explained hereinafter. In the present configuration, to define mapping between a plurality of the above host computers and a plurality of the LVs, first group the host computers and the LVs.
FIG. 3 illustrates an example of contents of the host grouping table 3 included in FIG. 2 ; that is, the contents are set as the result of grouping the host computers. The host grouping table 3 contains entries that are set under management in the following columns: host identifier (ID) 3 a , address 3 b , and OS 3 c , which are information specific to a host computer, and host group number (host group #) 3 d which is information for grouping the host computers. The host identifier 3 a is a user-defined character string to identify a host computer. The address 3 b is information to identify a host computer on the network and the address identifier to be assigned to the host computer differs, according to the type of the interface connecting the host computers and the storage systems. For example, if the interface is fiber channels, Host Bus Adapter (HBA) ports are physical connections of the host computers to the fiber channels and the WWNs of the ports are assigned for the host address information on the network. The table contents shown in FIG. 3 are illustrative of the settings in the case where the fiber channels are used. For address “WWN.HA0” in the address 3 b column, the “WWN” part indicates the address type WWN and an actual WWN value is assigned to the “HA0” part. The host group number (host group #) 3 d indicates a host group to which a host computer belongs. Host computers having the same host group number are grouped.
FIG. 4 illustrates another example of contents of the host grouping table as the result of grouping the host computers if the host computers and the storage systems are connected by an Internet Protocol (IP) network. Difference from the table contents shown in FIG. 3 is the contents in the address 3 b column. If the connection is made via the IP network, network cards are physical connections of the host computers to the IP network and Media Access Control (MAC) addresses are assigned for host address information on the network. For address “MAC.HA0” in the address 3 b column, the “MAC” part indicates the address type MAC and an actual MAC address value is assigned to the “HA0” part.
FIG. 5 illustrates a further example of contents of the host grouping table in which the addresses in the address 3 b column are described in a form independent of the type of the interface connecting the host computers and the storage systems. In the address 3 b column of the table shown in FIG. 5 , generic address expression “HA” represents the address of a host computer. In actuality, however, a specific address value and address type in combination are stored in the address column fields, according to the type of the connection interface.
FIG. 6 illustrates an example of contents of the LV grouping table 4 included in FIG. 2 ; that is, the contents are set as the result of grouping the LVs. The LV grouping table 4 shown in FIG. 6 contains entries that are set under management in the following columns: LV identifier (ID) 4 a , storage system number 4 b , LV number (LV#) 4 c , address 4 d , and size 4 e , which are information specific to an LV, and LV group number (LV group #) 4 f which is information for grouping the LVs. The LV identifier 4 a is a user-defined character string to identify an LV and associated with a storage system number 4 b that has the LV identified by it and an LV number 4 C to identify the LV within the storage system. The address 4 d is information to uniquely identify the LV on the network. As described for the addresses of the above host computers set in the address 3 b column, address information to be stored in the address column fields differs, according to the type of the interface to which the storage system is connected. If the storage system is connected to fiber channels, the WWN of the storage system's port and higher-level interface identifying information are assigned in combination. For example, if a Small Computer System Interface (SCSI) is used as the higher-level interface, identification information prescribed for the interface, that is, SCSI ID and Logical Unit Number (LUN) are added to the WWN to identify the LV. If the storage system is connected to the IP network, the MAC address of the network card of the storage system and the higher-level interface identifying information such as SCSI are assigned in combination. The LV group number (LV group #) 4 f indicates an LV group to which an LV belongs. LVs having the same LV group number are grouped.
FIG. 7 illustrates an example of contents of the host-to-LV mapping table 5 included in FIG. 2 .
The host-to-LV mapping table 5 shown in FIG. 7 maps a host group number (host group #) 3 d ( 5 a ) from the host grouping table 3 to an LV group number (LV group #) 4 f ( 5 b ) from the LV grouping table 4 . The mapping of a host group to an LV group in the host-to-LV mapping table 5 means that the host computers making up the host group are permitted to access the LVs making up the LV group.
How to operate the resources management utility 7 on the administrative terminal 6 shown in FIG. 1 will be explained below.
FIG. 8 illustrates an example of a window of the resources management utility 7 included in FIG. 1 . The resources management utility 7 provides means for grouping host computers, means for grouping LVs, and means for mapping a host group to an LV group. The window of the resources management utility 7 includes a host list 71 listing the host computers on the network, a “make host group” button 72 for making a new host group, an LV list 73 listing the LVs on the network, a “make LV group” button 74 for making a new LV group, and a “map” button 75 for mapping a host group to an LV group. Assume that the window shown in FIG. 8 have entries as exemplified in the host and LV lists immediately after activating the resources management utility 7 . To group host computers, first select host computers to make up a group from the host list 71 . The selected state of a host computer is clearly distinguished in appearance by difference in the background color between the line of the selected one and other lines or specially provided flags and the like. After selecting the host computers to make up a group, by clicking the “make host group” button 72 , the selected host computers are grouped. To group LVs, select LVs to make up a group from the LV list 73 in the same way as for grouping host computers, and click or press the “make LV group” button 74 , then grouping the LVs is completed. After the completion of grouping the host computers and grouping the LVs, click the map button 75 , then mapping the host group to the LV group is executed. When the map button 75 is clicked, the information for the host computers making up the host group and the information for the LVs making up the LV group are sent to the resources manager.
Using FIG. 1 and FIG. 9 , a procedure will be described below in which the setup request handler 2 of the resource manager 1 shown in FIG. 1 receives the information for the host computers making up a host group and the information for the LVs making up an LV group and completes access rights related settings on the storage system 9 and the switch 12 .
(1) Step 100
To fulfill a user request to map a host group to an LV group, the resources management utility 7 sends the resources manager 1 a setup request to map the host group to the LV group with the information for the host computers making up the host group and the information for the LVs making up the LV group. The setup request handler 2 of the resources manager 1 receives the setup request to map the host group to the LV group.
(2) Step 101
The setup request handler 2 determines whether the information for the host computers making up the host group, included in the received request, is new host group information not registered in the host grouping table 3 .
(3) Step 102
If the information for the host computers making up the host group is new host group information, the setup request handler 2 adds that information to the host grouping table 3 .
(4) Step 103
The setup request handler 2 determines whether the information for the LVs making up the LV group, included in the received request, is new LV group information not registered in the LV grouping table 4 .
(5) Step 104
If the information for the LVs making up the LV group is new LV group information, the setup request handler 2 adds that information to the LV grouping table 4 .
(6) Step 105
The setup request handler 2 adds the host group and the LV group to the host-to-LV mapping table.
(7) Step 106
The setup request handler 2 determines whether one of the storage systems having at least one of the LVs making up the LV group has an LV allocation facility.
(8) Step 107
If one of the above storage systems has the LV allocation facility, that is, the storage system is furnished with the LV allocation table and the LV allocation table manager 10 , the setup request handler 2 sends a request to set the LVs to the LV allocation table manager 10 of the storage system.
(9) Step 108
The setup request handler 2 derives the information to identify the ports of the host computers from the addresses of the host computers making up the host group and the information to identify the ports of the storage systems that provide the LVs from the addresses of the LVs making up the LV group.
The setup request handler 2 sends a request to set the host computer ports and storage system ports to the port mapping table manager of the switch 12 . Then, the port mapping table 14 is updated so that I/O requests sent from the host computers through their ports are permitted to access the LVs through the ports of the storage systems that provide the LVs.
According to the above-described embodiment, on-line storage resources, that is, a plurality of types of storage systems existing on a computer network can be allocated and managed by a common host-to-LV mapping scheme using grouping, which makes the type of the interface embodying the computer network and the type of the storage systems transparent to users that requests host-to-LV mapping.
According to the present invention, even if different type of storage systems exist on a computer system, the resources of the storage systems can be allocated and managed by the common host-to-LV mapping scheme.
While the preferred embodiment of the present invention was described hereinbefore, the invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Therefore, the described embodiment is to be considered in all respects only as illustrated and not restrictive. The scope of the invention is indicated by the appended claims. All modifications and changes which come within the meaning and range of equivalency of the claims are to be embraced within the scope of the invention.
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A resources managing program is provided on a computer network for converting a resources allocation request issued from a user into a setup request adapting to the type of storage systems that are resources on the network. Computer network interface type information is added to the address of each resources unit of the storage systems and stored as a part of management object information that a resources managing program holds for management. The request received is converted into a setup request adapting to the type of the interface.
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a novel apparatus utilizing fiber optics for colorimetric measurement of chemical properties. More particularly, this invention relates to a fiber optic probe which employs a confronting face optical gap measurement configuration while allowing an overall probe diameter sufficiently small to permit the probe to be inserted into living tissue directly or by prior insertion into a 16-gauge or smaller hypodermic needle.
2. Background Art
Colorimetric measurement of chemical properties is well known in the art. One simple example is the use of a phenophthalein solution which turns red in the presence of a base while becoming clear in the presence of an acid. The use of a colorimetric substance in combination with a fiber optics light source and detector has been taught by many references. Light supplied through a transmitting optical fiber is transmitted through a colorimetric substance mixed with a chemical whose properties are to be measured, and received by a receiving optical fiber which transmits that light to a light detector. A change in color of the colorimetric substance thus changes the light transmissivity of the mixture resulting a different amount of light measured by the light detector. The use of light for the measurement of such quantities as blood pH in vivo is superior to electrical measurement because of the resulting reduced irritation and shock hazard to living tissue. The optical fibers provide a means of channeling the light and making a measurement probe of convenient size.
In prior art configurations, a first optical fiber is connected at one end to a light transmitter and has its opposite end prepared by making a cut at 90° to the axis of the fiber to form a face. A second optical fiber is connected to a light detector at one end and has a face prepared on its opposite end in a manner like that of the first optical fiber.
In one common configuration, the faces of the two optical fibers are arranged so as to confront each other, allowing light from the transmitting fiber to be directed through the chemical to be measured and directly into the face of the receiving optical fiber. The two faces are thus parallel and separated from one another by a distance of typically 0.01 in. so as to form an optical gap. In the simplest configuration of this type, the optical fibers may extend away from the optical gap with their respective axes coincident. A small and more manageable configuration is made by bending the optical fibers so that they may be arranged parallel to one another at a distance away from the optical gap. Such a configuration has been taught in U.S. Pat. No. 3,123,066 by Brumley.
Using the configuration as taught by Brumley, an optical probe may be constructed in which the body consists of two parallel optical fibers suitably fastened together to produce a relatively small diameter probe body. There has been thought to exist a fundamental lower limit to probe tip size, since the respective optical fibers must be bent away from the direction of the probe body direction near the tip and then bent back toward each other to permit the respective faces to closely confront each other at the optical gap. The fundamental lower limit in probe tip size results from the fact that there is a lower limit to the bending radius of the optical fiber. The literature of the fiber optics art teaches that an optical fiber exhibits dramatically reduced transmissivity when bent with a bending radius near that of its outer diameter.
A second configuration has been used which allows a smaller probe tip size. An example of this configuration is disclosed by Peterson, et al., in U.S. Pat. No. 4,200,110. The two optical fibers are arranged parallel to each other along the entire probe length. At the tip, the optical fiber faces are arranged so that they are generally parallel but face the same direction rather than confronting one another. In such a configuration, light is transmitted into the chemical to be measured, thence reflected back to be received at the face of the receiving optical fiber. Light reception then depends upon either the light scattering properties of the chemical to be measured, or upon placement of a reflector at the probe tip. While this second configuration does not require the bending of the optical fibers, it does result in a reduced amount of light available at the face of the receiving optical fiber.
Both configurations have a common disadvantage, in that the measurement chamber is located at the tip of the probe. This limits the sharpness of the probe. Also, there is a greater opportunity for tip breakage if the probe is inserted directly into living tissue. In the prior art, one way of protecting the probe tip has been to insert the probe into a hypodermic needle, and then insert the needle into living tissue. Placement of shielding material at the probe tip interferes with the introduction of the chemical to be colorimetrically measured into the measurement chamber.
SUMMARY OF THE INVENTION
The present invention provides a confronting face optical gap measurement configuration without the attendant large probe tip size disadvantage found in the prior art. In the present invention, a first optical fiber, which may be either the transmitting or receiving fiber, is so constructed to have a sharp, 180° bend placed in it near its face so as to form a hook shape. The face end of the optical fiber is brought back parallel to and closely spaced from the portion of the fiber on the other side of the bend. The bend is referred to as sharp in that the bending radius is smaller than the optical fiber art teaches is possible without unduly reducing the light transmissivity of the fiber. More specifically, a sharp bend in an optical fiber is one in which the bending radius is of the same order of magnitude as the diameter of the optical fiber.
A second optical fiber is laid parallel to the first optical fiber so that its face is parallel to and confronting the face of the first optical fiber. A suitably rigid coating material of epoxy resin or the like, is applied to the two optical fibers to hold the fibers in their respective positions and give the probe structural strength. A sample chamber bored into the protective coating exposes the optical gap and holds the colorimetric substance into which the chemical to be measured is introduced. A semipermeable membrane covers the opening of the sample chamber thereby holding in the colorimetric substance while allowing the chemical to be measured to pass into the sample chamber.
It should be noted that the term semipermeable as applied to membranes admits of two meanings in the relevant literature. An older meaning relates to membranes which allow flow of fluid through them in one direction while preventing flow in the opposite direction. A second meaning of semipermeable as applied to membranes, and the meaning used herein, relates to membranes which allow flow through them substantially equally well in both directions of selected fluids while being substantially equally impervious in both directions to other fluids.
The above description recites the use of two optical fibers, one of which has a tight bend placed in it before probe assembly. In practice, a probe of the type disclosed may be constructed by bending a single optical fiber double in a tight bend and then applying the coating material starting at the tip and moving back along the doubled length of the fiber. When the coating material has dried to form a rigid coating, the sample chamber and optical gap are formed by cutting a slit in the probe. The process of cutting the sample chamber into the tip support coating also results in the severing of the single optical fiber so as to produce the above recited structure containing two optical fibers.
The invention incorporates the advantages of the confronting face optical gap of Brumely while achieving the inherently smaller probe tip size of Peterson, et al. The invention has a further advantage over both the Peterson and Brumley configurations in that the measurement chamber is located on the side of the probe rather than on the tip. The tip thus may be made sufficiently strong and small to permit the probe to be inserted directly into living tissue without being first inserted into a hypodermic needle.
The invention has applications outside the biomedical field in such areas as the food industry. For example, the ruggedness and small size of the probe tip allow insertion into fresh fruit or meat to measure chemical properties therein. Only minimal deformation of the fruit or meat will result from the insertion due to the tip's small size.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the invention may be more fully understood from the following description read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a cross-sectional view of the optical probe showing its details of construction and its connection to a light source and detector.
FIG. 2 is an enlarged cross-sectional view of the probe tip showing the details of the sample chamber.
FIG. 3 illustrates the directional properties of the optical fiber as they relate to the determination of the width of the optical gap.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a cross-sectional view of the optical probe may be seen. A probe body 12 is comprised of a first optical fiber 18 and a second optical fiber 16 encapsulated by a protective sheath 14. The protective sheath 14 is preferably a flexible cylindrical tubing approximately 3.5 inches in length made of a material such as teflon. The teflon tubing is thin walled, having an inner diameter of approximately 0.02 inch and a wall thickness of about 0.002 inch. A tip support coating 24 covers the portion of the optical fibers 16 and 18 which protrude about 0.2 inches from one end of the protective sheath 14, and further extends inside the protective sheath 14. A sample chamber 22 opens on the surface of the tip support coating and extends into the interior of the tip support coating 24 for a distance of approximately 0.5 inches.
FIG. 1 shows the optical fibers 16 and 18 spaced apart a distance greater than the diameter of the fibers 16 and 18 primarily to better show the details of construction. Also, considerable space is shown between the inner wall of the protective sheath 14 and the optical fibers 16 and 18, again to better show the construction details. In actual implementation, the protective sheath 14 fits tightly over the optical fibers 16 and 18, so as to force the fibers 16 and 18 to touch each other throughout the interior of the protective sheath 14.
The optical fiber is preferably constructed of polymethyl methacrylate core with an outer covering of transparent polymer of a lower index of refraction than that of the core. A typical outer diameter of the fiber used is about 0.01 inches. Fibers of this type, bundled in groups of up to 64 and covered with a polyethylene resin jacket are sold by Dupont under the registered trademark CROFON. A Dupont 0E0011 optical fiber, not covered by the polyethylene resin jacket, is a suitable fiber for implementation of the present invention.
The tip support coating 24 is preferably an epoxy material which may be applied as a liquid and allowed to dry to a rigid covering. Although FIG. 1 shows the tip support coating 24 to be opaque for clarity, the tip support coating 24 may equally well be transparent or translucent. In addition to providing a rigid protection for the tip 20 and a surrounding medium for the same chamber, the tip support coating helps to anchor the end of the protective sheath 14.
The distal ends of the optical fibers 16 and 18 are optically connected to a light source 10 and a light detector 12 by means of standard and readily available optical couplers, thus permitting the transmission of light through the optical fibers 16 and 18. It should be emphasized that the probe will also function with the light detector 12 connected to the second optical fiber 16 and the light source 10 connected to the first optical fiber 18, allowing the transmission of light in a direction opposite that shown in FIG. 1.
It can be seen that the second optical fiber 16 is arranged parallel and closely spaced from the first optical fiber 18. The first optical fiber 18 extends beyond the proximate end of the second optical fiber 16 and traverses a sharp, 180° bend so that the proximate ends of the optical fibers 16 and 18 confront each other from opposite sides of the sample chamber 22. A tip 20 is formed by the sharp, 180° bend. In practical construction, the optical fibers 16 and 18 would begin as parts of a single optical fiber doubled and drawn through the protective sheath 14, with the tip support coating 24 applied as a liquid. When the tip supporting 24 has hardened, the sample chamber 22 is cut into the hardened tip supporting 24 with the single optical fiber being thus severed to form two separate optical fibers 16 and 18 arranged as shown.
Referring now to FIG. 2, a more detailed view of the optical probe near the tip 20 and sample chamber 22 may be seen. The sharpness of the 180° bend at the tip 20 may be more specifically defined in terms of the bending radius 32 measured from the center of curvature 33 of the bend to the axis 34 of the first optical fiber 18. So as to effect a small tip size, the bending radius is made less than or equal to the diameter of the first optical fiber 18. The fiber optics art teaches that the transmissivity of an optical fiber may drop to 60% or less of its straight line transmissivity when bent with a bending radius this small compared to its diameter. Manufacturers of optical fibers therefore recommend that larger bending radii be used for proper optical fiber operation. The successful operation of the probe while utilizing a bending radius 32 which is less than or equal to the diameter of the first optical fiber 18 is thus a surprising and non-obvious result in view of the prior art teachings.
Proper functioning of the probe with such a small bending radius 32 in contradiction to the accepted understanding in the optical fiber art appears to be based on two factors. First, many applications require optical fiber runs of tens to hundreds of feet in length in which many bends may be required. In such an application, the cumulative reductions in transmissivity caused by long fiber lengths and multiple bends require limitation of losses due to any one bend. The present invention requires a fiber length of the order of 3 feet or less and only one high loss bend. Thus, the high transmissivity loss occasioned by the bend at the tip 20 is not fatal to probe operation.
Secondly, many fiber optics applications involve the transmission of complex waveforms such as that of speech. Small radius bends such as that used in the present invention will cause severe distortion of such complex waveforms. In the present invention, only the amplitude of the light transmitted is measured, so that waveform distortion and resulting unintelligibility of the transmitted light signal is not a factor in probe operation.
Further referring to FIG. 2, details of the sample chamber 22 and the surrounding structure may be seen. The proximate ends of optical fibers 16 and 18 are prepared with faces 28 and 30 respectively. The faces 28 and 30 are flat and are cut so as to be generally perpendicular to the axes of optical fibers 16 and 18 respectively and one thus generally parallel to one another. The faces 28 and 30 are spaced apart to form an optical gap 23. The axis 34, extended beyond face 30 toward face 28, will be seen to be coincident with axis 17.
A maximum width of the optical gap 23 is determined by two factors. First, as the optical gap 23 is increased, less light is received at the receiving face from the transmitting face. Note that in FIG. 2 the face 28 is the transmitting face because the second optical fiber 16 is optically connected to the light source 10. As previously disclosed, the first optical fiber 18 could as well be the fiber optically connected to the light source 10, with the light detector 12 being connected to the second optical fiber 16, thus reversing the transmitting and receiving roles of the faces 28 and 30, respectively.
A second factor affecting the maximum width of the optical gap 23 is the possibility of receiving light at the receiving face 30 from sources other than the transmitting face 28. Referring now to FIG. 3, it can be seen that the faces 28 and 30 are directional in their respective transmitting and receiving functions. Directivity patterns for transmitting and receiving light from the faces of Dupont CROFON optical fibers are shown. Light transmitted from the transmitting face 28 is primarily confined to a transmitting cone of 20° about the axis 17 of the second optical fiber 16. The receiving face 30 takes in light which is primarily confined to a reception cone of 60° about the axis 34 of the first optical fiber 18. If faces 28 and 30 are separated by a distance X greater than d/2 tan 30°=0.868d, where d is the diameter of the optical fibers, light may be received from ambient sources other than the transmitting face 28, thereby influencing the accuracy of the measurement. Experimentation has shown that examples of the invention having an optical gap 23 of width equal to 1.5 times the diameter of the fibers 16 and 18 are workable but inefficient.
Referring again to FIG. 2, it is seen that the sample chamber 22 is filled with a colorimetric substance 25. The colorimetric substance 25 is such that it is permeable to the chemical to be colorimetrically measured. During the measurement process, the chemical to be colorimetrically measured enters the sample chamber 22 through the semipermeable membrane 26 and permeates the colorimetric substance 25. If the desired property is present in the chemical the colorimetric substance will change color and thus its transmissivity to light will be altered. A change in the intensity of light transmitted from the transmitting face 28 through the sample chamber 22 and received at the receiving face 30 will be detected by the light detector 12, thus signaling the presence of the property sought to be detected.
A colorimetric substance 25 is made by introducing a dye into a porous support medium. One practical embodiment of the porous support medium consists of small glass microspheres with a diameter of approximately 10 micrometers mixed with water to form an aqueous slurry. Irregularly shaped particles with maximum dimensions in the range of 1-100 micrometers may be used in place of the microspheres. Polyurethane particles have also been used although better results have been obtained with glass. The dye is bound to the particles or microspheres before the water is introduced. The addition of water to the particles or microspheres helps to hold the particles or microspheres in place when the semipermeable membrane is applied.
A wide variety of dyes is commercially available in a variety of colors. One example of a dye which has been by some researchers used for the colorimetric measurement of oxygen absorption in the blood is perylene dibutyrate, sold as Thermoplast Brilliant Yellow 10G by BASF-Wyandotte Corporation. The binding of the dye to the support medium may be accomplished by washing the glass particles or microspheres with the dye mixed with an organic solvent such as dichloromethane. A more detailed description of dye selection and the preparation of the porous support medium and dye is presented in the paper entitled "Fiber-Optic Probe for In Vivo Measurement of Oxygen Partial Pressure" by Peterson, Fitzgerald and Buckhold in Analytical Chemistry, Vol. 56, No. 1, January, 1984. Harper, in his article entitled "Reusable Glass-Bound pH Indicators" published in Analytical Chemistry, Vol. 47, No. 2, February, 1975, has taught the use of an immobilized subtheilein indicator dye bound to glass fragments for use in pH measurements.
A porous support medium may also be implemented using a solid, porous material such as glass or polyurethane filling the sample chamber. Dye of a suitable type may be imparted into the interstices of the medium and allowed to adhere to the walls thereof. Experimentation has shown the slurry type medium to be somewhat easier to apply to the sample chamber.
The semipermeable membrane 26 is preferably implemented by applying a 2% solution of a cellulose acetate dissolved in a solvent made of 50% acetone and 50% cyclohexanone. The solution is sprayed on as an aerosol after the aqueous slurry is introduced into the sample chamber 22. The aerosol will dry to form a membrane 26 which will serve to hold in the glass particles of the porous support medium while allowing water to flow through the membrane 26.
Increasing the concentration of the cellulose acetate in the solution will result in a smaller pore size in the membrane 26. Extensive literature available on the manufacture of cellulose acetate membranes teaches that concentration of cellulose acetate higher than 2% may be used to produce a membrane permeable to gasses while nonpermeable to water. Such a membrane 26 would be used to hold in the water in the slurry so that a gas to be colorimetrically measured would be dissolved in the water.
The foregoing description of the invention has been directed to a particular preferred embodiment in accordance with the requirements of the patent statute and for purposes of explanation and illustration. It will be apparent, however, to those skilled in this art that many modifications and changes in the embodiments described and illustrated herein may be made without departing from the spirit of the invention.
The following claims are intended to cover such modifications and variations as they fall within the true spirit and scope of the invention.
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A fiber optical probe for colorimetric measurement of chemical properties suitable for the insertion into living tissue. A chemical to be colorimetrically measured is introduced into a sample chamber on the side of the probe near the probe tip. A colorimetric substance contained in the sample chamber changes colors in response to chemical properties of the chemical to be colorimetrically measured, thereby changing the amount of light transmitted through the sample chamber by the optical fibers.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ESD protection device modeling method of modeling the electrical characteristic of an electrostatic discharge (ESD) protection device to simulate a circuit that includes the ESD protection device and an ESD simulation method of simulating the ESD protection device.
[0003] 2. Description of the Related Art
[0004] In recent years, the ESD destruction of a device becomes a serious problem in the large scale integration or miniaturization of semiconductor integrated circuits and the self-aligned silicide (Salicide) process for reducing the resistance between devices, making it necessary to use an ESD protection device. The conventional ESD protection device and ESD protection circuit simulation, however, are very complicated and difficult to set each parameter for modeling the device.
[0005] For example, Japanese Patent Application Kokai No. 2001-339052 discloses a method of simulating a protective circuit against the ESD destruction. That is, to model an ESD protection device, first, a model for the equivalent circuit of an ESD protection device is made, and measurement is taken for the device made by the final process or the physical parameter is extracted from the electrical characteristic obtained by the device simulation to form an equivalent circuit. Then, 100 or more model parameters of the equivalent circuit must be further fitted or adjusted.
[0006] This method is applicable to a relatively large IC by way of the equivalent circuit of the ESD protection device. However, the formation of the equivalent circuit needs the adjustment of many parameters. In addition, if the production process is changed by circuit correction, for example, no simple operation, such as parameter change, can solve the problem. That is, if the production process is changed, the model parameters for the previous modeling are no longer useable, and the model parameters for forming the equivalent circuit must be adjusted again. Moreover, the above method is only a circuit simulation and fails to specify the destruction location by ESD.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the invention to provide an ESD protection device modeling method capable of predicting the characteristic of an ESD protection device with simple steps and, if the production process is changed, predicting the characteristic change of the ESD protection device, the ESD destruction location, and the ESD resistance by using the previous parameters, and an ESD simulation method.
[0008] According to an aspect of the invention there is provided an ESD protection device modeling method of modeling an electrical characteristic of a protection device against electrostatic discharge or ESD protection device for simulating a circuit that include the ESD protection device, comprising the steps of setting a parameter of at least one specific element that affects the electrical characteristic of the ESD protection device; and modeling the electrical characteristic of the ESD protection device with the parameter for the specific element. The simulation including the ESD protection device may be a device simulation that physically simulates the electrical state of the device.
[0009] To model the ESD protection device, at least one specific element is extracted, and the parameter for each specific element is set independently to form the characteristic of the ESD protection device. Especially, where the production process is changed due to a circuit correction, the parameter of only the specific element affected by the process change is changed to predict the characteristic change of the ESD protection circuit without difficulty.
[0010] In addition, prior to the parameter setting step, the step of forming an impurity profile representing a density distribution of an impurity in the ESD protection device obtained by secondary ion mass spectrometry (SIMS) to determine the parameter of the ESD protection device may be included. The parameter of the specific element may be determined according to the impurity profile.
[0011] The impurity profile may be formed by the process simulation for the production process. Also, it is possible to use the inverse modeling technology that uses the measured electrical characteristic of the device to extract the impurity profile by simulation. The parameter of at least one specific element is determined by the thus formed impurity profile. In the parameter setting step, the parameter for a specific element other than the above determined specific element is set.
[0012] The parameter setting step may include the step of comparing a snapback characteristic of a voltage/current characteristic of the ESD protection device measured by transmission line pulse (TLP) measurement for evaluating the electrical characteristic of the ESD protection device and a snapback characteristic corresponding to the specific element to set a parameter of the specific element such that a snapback characteristic of combination of the specific elements is substantially equal to the snapback characteristic by the TLP measurement. The specific element depending snapback characteristic may have been measured for a plurality of parameters for each specific element.
[0013] The TLP measurement is made by applying a current pulse having a predetermined width to the device to provide the voltage/current characteristic, especially for the d-c component, of the device. The snapback characteristic is the drain voltage/drain current characteristic, with the gate and source voltage fixed at 0 V, showing a snapback action. The snapback action is characterized by the avalanche breakdown due to the increased train voltage, the substantially constant holding voltage capable of conducting a predetermined current after the avalanche breakdown, and the thermal runaway (device destruction) where current higher than the above current is conducted. The ESD protection device makes use of such a snapback characteristic to conduct the ESD current through the ESD protection device, thus protecting the other circuit.
[0014] With this structure, it is possible to predict the parameter of each specific element by referring to the snapback characteristic curve of an actual ESD protection device. The snapback characteristic of a specific element varies with the parameter so that the parameter can be determined. By combining with the profile forming step it is possible to limit the parameter to be determined, making possible to set a more accurate parameter. If the production process is changed, by comparing the snapback characteristic before and after the change, it is possible to predict which process affects which specific element.
[0015] The parameter setting step further includes the step of comparing a current transient characteristic measured by conducting current through the ESD protection device and the specific element depending current transient characteristic to set a parameter of the specific element such that a current transient characteristic of combination of the specific elements is substantially equal to the measured current transient characteristic. The specific element depending current transient characteristic may have been measured for a plurality of parameters for each specific element.
[0016] In view of the waveform of current transient characteristic of an actual device, it is possible to predict the parameter of each specific element. The current transient characteristic of each specific element varies with the parameter so that the parameter can be determined from the characteristic of the specific element. By combining with the profile forming step, it is possible to limit the parameter to be determined, making it possible to set a more accurate parameter. If the production process is changed, by comparing the current transient characteristic before and after the change, it is possible to predict which process affects which specific element.
[0017] By comparing the current transient characteristic after the parameter is set by comparison of the snapback characteristics, it is possible to finely adjust the parameter. With this structure, it is possible to form an appropriate transient characteristic including a characteristic for the d-c component of the ESD protection device and to raise the reliability of the parameter for the modeled ESD protection device.
[0018] Where the ESD protection device is made up of a plurality of ESD protection elements, the parameter setting step further may include the step of comparing a total current transient characteristic measured by conducting current through the ESD protection elements a current transient characteristic of each ESD protection element to set a parameter for a current ratio such that the current transient characteristic of combination of the ESD protection elements is substantially equal to the measured total current transient characteristic.
[0019] The parameter for a current ratio includes the wiring resistance connected to respective ESD protection elements, and only the ratio of currents through the ESD protection device can be changed without changing the parameter of the already set specific element. With such a structure, it is possible to provide a more accurate model of the ESD protection device.
[0020] Where the ESD protection device is composed of a plurality of ESD protection elements, the parameter setting step further may include the step of comparing a current branching rate obtained by conducting current through the ESD protection elements to measure the ratio of currents through the respective ESD protection elements and a current branching rate of each ESD protection element in the simulation to set a parameter for a current ratio such that a current branching rate obtained by combination of the ESD protection elements is substantially equal to the measured current branching rate.
[0021] With such a structure as stated above, only the ratio of currents through the ESD protection device can be changed without changing the parameter of the already set specific element, thus providing a more accurate model of the ESD protection device.
[0022] The specific element may be selected from the group consisting of a source-drain diffusion layer density, a pocket implantation, a source-drain diffusion depth, a gate-source-drain overlap length, a saliside block length, an impact ionization coefficient, a source-drain resistance, and a substrate resistance. The source/drain diffusion layer density is the density of the source and drain layers of an MOSFET or ESD protection device. The pocket implantation, also called “halo implantation”, is a high density portion provided on the source and drain side of the gate to control decrease of the threshold voltage by the short channel effect that when the source-substrate channel becomes short, the drain voltage raises the substrate potential, reducing the voltage between the source and the substrate, allowing more current to flow. The source/drain diffusion layer depth is the depth (Xj) of source and drain diffusion layers. The source and drain are made simultaneously by the source drain implantation step so that the diffusion layer depths are equal.
[0023] The gate source drain overlap length is the length of overlap between the gate and source or gate and drain layers. The saliside block length is the length of a region to block the saliside. The saliside block is a region with no saliside to raise the resistance of the drain region (sometime including the source region) or the breakdown resistance of only the ESD protection device with respect to the saliside forming region provided to reduce the drain resistance. The impact ionization coefficient α is the coefficient for the impact ionization rate G corresponding to the number of electrons and holes generated per second per volume. The impact ionization rate G (cm −3 /s) is given by α×(J/q)×exp(E) wherein the J is the current density, E the electric field, q the charge. The source/drain resistance is the resistance of the added source and drain. The substrate resistance is the resistance of a wafer on which the ESD protection device is formed and is equal to the resistance of a substrate that is not included in the analyzing area.
[0024] With such a specific element, it is possible to differentiate the characteristic of the ESD protection device. According to the modeling level, the parameters can be set for all of the specific elements but, in the simple modeling in the initial simulation, an easily derived element may be extracted from the specific element group to set the parameter. The specific element for which the parameter is determined according to the impurity profile may be the source/drain diffusion layer density, the pocket implantation, the source/drain diffusion layer depth, the overlap length, and the saliside block length.
[0025] According to another aspect of the invention there is provided an ESD simulation method of simulating an ESD resistance of an integrated circuit including an ESD protection device, comprising the step of providing a breakdown voltage where an ESD breakdown takes place in an actual device; finding a reference voltage applied to each element when the breakdown voltage is applied artificially to the modeled integrated circuit; comparing the reference voltage and a voltage upon the each element of a newly modeled integrated circuit to estimate a breakdown location and an ESD resistance of the integrated circuit.
[0026] The model made by the ESD protection device modeling method is used appropriately in the simulation. The modeling method is not a mere conversion to the equivalent circuit so that it is possible to simulate the voltage locally generated in each ESD protection element, thereby making it possible to predict the ESD breakdown location or the ESD resistance.
[0027] As has been described above, according to the invention, the characteristic of an ESD protection device is predicted by a simple process without difficulty. Even if the production process is changed, the parameter of only the specific element depending on the process change is changed to predict the characteristic change of the ESD protection device after the process change. The use of measurements of the device after the process change enables to provide a more reliable simulation model. Furthermore, it is possible to predict the ESD destruction location or ESD resistance after the process change.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a flow chart for modeling an ESD protection device;
[0029] FIG. 2 is a graph showing the snapback characteristic of a current/voltage curve;
[0030] FIG. 3 is a diagram showing the impurity profile of an ESD protection device;
[0031] FIG. 4 is a graph showing the impurity density in the direction of a channel depth;
[0032] FIG. 5 is a graph showing the impurity density with respect to the source-drain depth;
[0033] FIG. 6 (A) is a graph showing snapback characteristics for a source-drain diffusion layer density;
[0034] FIG. 6 (B) is a graph showing snapback characteristics for a pocket implantation;
[0035] FIG. 6 (C) is a graph showing snapback characteristics for a source-drain diffusion layer depth;
[0036] FIG. 6 (D) is a graph showing snapback characteristics for a gate/source/drain overlap length;
[0037] FIG. 6 (E) is a graph showing snapback characteristics for a saliside block length;
[0038] FIG. 6 (F) is a graph showing snapback characteristics for an impact ionization coefficient;
[0039] FIG. 6 (G) is a graph showing snapback characteristics for a source-drain resistance;
[0040] FIG. 6 (H) is a graph showing snapback characteristics for a substrate resistance;
[0041] FIGS. 7 (A) and 7 (B) are a graph showing snapback characteristics of an nMOS model and measurements;
[0042] FIGS. 8 (A) and 8 (B) are a graph showing snapback characteristics of a pMOS model and measurements;
[0043] FIG. 9 is a circuit diagram of an ESD protection device including two MOSFETs;
[0044] FIG. 10 is a graph showing a transient voltage input to the ESD protection device;
[0045] FIG. 11 is a graph showing the current transient characteristics of an ESD protection device model and measurements;
[0046] FIG. 12 is a graph showing the current branching rates of an ESD protection device model and measurements; and
[0047] FIG. 13 is a circuit diagram of a circuit including an ESD protection device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0048] In FIG. 1 , an ESD protection device modeling method 110 includes a profile forming step 112 , a parameter setting step 114 , and a modeling step 116 . The modeled ESD protection device is simulated along with other Ics by an ESD simulation method 120 .
[0049] In the profile forming step 112 , an impurity profile is made by the secondary ion mass spectrometry. Such an impurity profile may be made by a process simulation for a production process. Also, an inverse modeling technology may be used to extract an impurity profile by simulation using the measured electrical characteristics of a device. The impurity profile determines the source-drain diffusion layer density, the pocket implantation, the source-drain diffusion layer depth, the overlap length, and the block length of a saliside among the specific elements or factors necessary for modeling an ESD protection device.
[0050] The parameter setting step 114 sets the parameters of a plurality of specified elements. Where the profile forming step 112 is executed, the parameters of a predetermined number of specified elements among the specific elements are determined, and the parameters of the impact ionization coefficient, source-drain resistance, and substrate resistance are set here. In this way, only the parameters for the specified elements are set independently to form the characteristics of the ESD protection device. Especially, where there is a change in the production process due to a circuit correction or the like, the parameter of only the specific element that is affected by the process change is changed in setting to form a new model for the ESD protection device.
[0051] Where the parameter of each specific element is known, the parameter is set, and the parameter difficult to be predicted is set by using the snapback characteristic comparison 130 or the current transition characteristic comparison 132 . Where there are a plurality of ESD protection devices or elements including n-channel and p-channel MOSFETs, the total current transition characteristic comparison 134 or the current branching rate comparison 136 is used to form a comprehensive model for the ESD protection devices. Although there are a plurality of ESD protection devices, the base is modeling each ESD protection device, and the total current transition characteristic comparison 134 and the current branching rate comparison 136 are used to correct the difference between the measurement and the setting.
[0052] The snapback characteristic comparison 130 compares the snapback characteristics of an actual device measured by the TLP method and those of a specific element to set the parameter for the specific element. Specifically, the specific element to be set is selected from a group of specific elements, and the shape of snapback characteristics of the measurement is compared with that of the selected specific element so that it approaches the measured snapback characteristic curve. Finally, the parameters of the set specific elements are summed up to do simulation to check if it is substantially equal to the measured snapback characteristics.
[0053] In FIG. 2 , the snapback characteristic is represented by an operation trace 150 of the drain current I D versus the drain voltage VD with the gate and source voltages fixed at 0 volt. When the drain voltage V D reaches the breakdown voltage V B , a predetermined value of current flows due to the avalanche breakdown, and the drain voltage V D becomes the holding voltage V H . When the current further increases, it reaches the thermal runaway A, which is normally a breakdown point. The breakdown voltage V B Of the ESD protection device is set higher than the operation voltage of an IC to use such a snapback action so that the current of electrostatic discharge flows through the ESD protection device to protect the other circuits.
[0054] The current transition characteristic comparison 132 compares the current transition characteristic measured by conducting current through the ESD protection device and that of the specific element to set a parameter for the specific element. The specific comparison method is the same as the snapback characteristic. The parameter set by the snapback characteristic comparison 130 may be adjusted by the current transition characteristic comparison 132 . The setting may be made in the reverse order, too. In this way, a reliable model is provided.
[0055] The total current transition characteristic comparison 134 compares the total current transition characteristic measured by conducting current through the ESD protection devices and the current transition characteristic resulting from the simulation of each of the ESD protection elements to set a parameter for the current ratio or the resistance of a wire connected to each ESD protection element or device.
[0056] The current branching rate comparison 136 compares the current branching rate obtained by measuring the rate of current through each ESD protection device and the current branching rate of each ESD protection device on the simulation to set the parameter for the current ratio in the same way as in the total current transition characteristic comparison 134 .
[0057] The modeling step 116 models the electrical characteristic of an ESD protection device with the parameter of a specific element. The parameter of the specific element is incorporated directly or indirectly in the device simulation to be used in the simulation of an ESD protection device.
[0058] The ESD simulation method 120 simulates the ESD resistance in a circuit including the modeled ESD protection device in the modeling step 116 . In this ESD simulation method, an actual device is used to cause an ESD to provide the breakdown voltage where the ESD occurred. The breakdown voltage is applied to an IC in the modeled simulation to take a voltage on each device as a reference voltage. Where there is a process change due to a circuit correction or the like, the voltage of each device of a new modeled IC is compared with the reference voltage to estimate the breakdown location and ESD resistance of the IC.
[0059] In the ESD protection device modeling method 110 , it is necessary to measure in advance the snapback characteristic for the parameter of each specific element. Once the snapback characteristic is measured for each specific element, the measurement can be used for a similar simulation, thus facilitating the characteristic assessment. The specific element depends on the production process so that even if the production process is changed, the parameter of only the specific element depending on the process change is changed to predict the characteristic change of the ESD protection device after the change without difficulty.
[0060] This easiness in the characteristic prediction of an ESD protection device becomes clearer by comparison with the conventional characteristic prediction. Heretofore, a model for the equivalent circuit of an ESD protection device is assumed, and the device made by the final process is measured, or the physical parameter is extracted from the electrical characteristic of a device simulation to form an equivalent circuit. It takes a very large amount of time to set all the parameters by adjusting the physical parameters of the device simulation. Then, it is necessary to adjust 100 or more model parameters for the equivalent circuit.
[0061] By contrast, in the above embodiment, only the parameters of specific elements depending on the process change are adjusted or about eight parameters are set to model the ESD protection device, thus providing a characteristic perdition in a short time without difficulty. Where the production process is changed due to a circuit correction or the like, the conventional method cannot use the previous model parameters and requires again adjustment of the model parameters for forming an equivalent circuit. In this embodiment, however, only the parameter depending on the process change is changed to provide without difficulty a prediction of the characteristic change of the ESD protection device after the change.
[0062] In addition, where a more reliable simulation model is formed, measurement is taken of the device after the change of a production process, and the parameter of the specific element is predicted from the result. In this way, the optimal simulation of an ESD protection device is made. Even if the production process is changed, it is easy to predict the characteristic change of an ESD protection device.
Second Embodiment
[0063] In the second embodiment, the profile forming step 112 and the parameter setting step 114 will be described in details. In the parameter setting step 114 , especially, the snapback characteristic comparison 130 will be described.
[0064] In FIG. 3 , the ESD protection device is represented by an MOSFET including a gate 210 , a source 212 , and a drain 214 . The impurity distribution B in the channel direction is shown in FIG. 4 , wherein the impurity density is plotted against the channel depth. The impurity density C in the source-drain direction is shown in FIG. 5 , wherein the impurity density is plotted against the source-drain depth. These densities and the density ratio of each portion have great influence on the electrical characteristic of an ESD protection device.
[0065] The impurity profile enables to determine the parameter for a specific element, such as the source-drain diffusion layer density, the pocket implantation, the source-drain diffusion layer depth, the overlap length, and the block length of a saliside, and, in the parameter setting step 114 , the parameter of only the impact ionization coefficient, the source-drain resistance, and the substrate resistance. The above parameters may be set by prediction from the changed element in the production process but, in this embodiment, the setting of parameter by the snapback characteristic comparison 130 will be described.
[0066] First of all, the snapback characteristic of an ESD protection device is obtained by the TLP measurement of an actual device. Then, it is compared with the snapback characteristic of each specific element that has been prepared in advance to calculate the parameter. This method is based on the estimation of an unknown parameter of a specific element resulting from the assumed result. Consequently, it is necessary to compare the curve of snapback characteristic in the parameter of each specific element with that of the measured snapback characteristic.
[0067] In FIG. 6A , only two source-drain diffusion layer densities 4×10 20/cm3 and 1×10 20/cm3 are given for simplicity purpose, but more parameters may be included. It is apparent from the curves that the gradient angle of avalanche breakdown varies with the parameter.
[0068] In FIG. 6B , two cases where there is a pocket and there is no pocket are shown. It is apparent that the curve of the pocket case slower than that of the none pocket case from the avalanche breakdown to the holding voltage.
[0069] In FIG. 6C , two cases wherein the diffusion layer depth is 0.03 um and 0.06 um are shown. The gradient angle after the avalanche breakdown is not affected by the depth of a diffusion layer but is shifted by the predetermined drain voltage.
[0070] In FIG. 6D , four overlap lengths 0.03 um, 0.00 um, −0.01 um, and −0.03 um are given. The curve after the avalanche breakdown is independent from the overlap length but the breakdown voltage before avalanche breakdown varies therewith.
[0071] In FIG. 6E , two saliside block lengths 1 um and 2 um are given. The gradient angle after the avalanche breakdown varies with the parameter.
[0072] In FIG. 6F , high and low impact ionization coefficients are given. The gradient angle after the avalanche breakdown is independent from the impact ionization coefficient but there is a shift by a predetermined drain voltage.
[0073] In FIG. 6G , two drain resistances 10 and 5 k ohms are given. The gradient angle after the avalanche breakdown with respect to the vertical line for the larger source-drain resistance is larger than that of the smaller source-drain resistance.
[0074] In FIG. 6H , three values of substrate resistance 0, 10 k, and 100 k ohms are given. The hold voltage and the curve after the avalanche breakdown vary with the parameter.
[0075] The change of curve with the parameter in each of the above figures can be compared with that of the measured for an actual device.
[0076] In FIG. 7A , the parameters determined for respective specific elements in an ESD protection device or n-channel MOSEFT are combined to provide a snapback characteristic. The simulation result expressed by solid line substantially matches the measurement curve given by a set of plots. The parameters of respective specific elements are 2 um for the saliside block length, 5 k ohms for the substrate resistance, and 4 k ohm for the source-drain resistance.
[0077] Where the production process is changed, it is easy to predict the characteristic change of the ESD circuit. For example, the saliside block length is changed from 2 um to 0.5 um, the conventional method requires readjustment of the model parameters to form an equivalent circuit but this embodiment requires change of only the parameter for the saliside block length to predict the electrical characteristics.
[0078] FIG. 7B shows consistency between the snapback characteristic formed by changing the parameter for the saliside block length and the snapback characteristic of measurements taken of the actual device after the change of a production process. An accurate model consistent with the actual device is provided by simply changing the parameter of a specific element that affects the electrical characteristic of an ESD protection device.
[0079] Similarly, a comparison is made between the model snapback characteristic and the measured snapback cartelistic for a p-channel MOSFET as an ESD protection device.
[0080] FIG. 8A shows the consistency between the snapback characteristic made by combining the parameters set for respective specific elements and the snapback characteristic made by measuring an actual device.
[0081] FIG. 8B shows the comparison between the simulation and the measurement where the saliside block length is changed from 2 um to 5 um to form an ESD protection device. As shown, an accurate model is provided for the p-channel MOSFET by simply changing the parameters of specific elements that affect the electrical characteristics of the ESD protection device.
Third Embodiment
[0082] In the third embodiment, the parameter setting step 114 for the total current transient characteristic comparison 134 and the current branching rate comparison 136 will be described in details. A plurality of MOSFETs are provided for an ESD protection device. The parameters for each MOSFET have been determined by the snapback characteristic comparison 130 or the current transient characteristic comparison 132 in the parameter setting step 114 . The total current transient characteristic comparison 134 and the current branching rate comparison 136 are used to finely adjust or correct the parameters determined by the snapback characteristic comparison 130 or the current transient characteristic comparison 132 .
[0083] In FIG. 9 , an ESD protection device is composed of a p-channel MOSFET or pMOS 310 and an n-channel MOSFET or nMOS 312 . An ESD surge voltage is applied to the pMOS 310 and nMOS 312 in parallel. The produced current is discharged to a device ground 314 through the pMOS 310 (Ip) and nMOS 312 (In).
[0084] FIG. 10 shows the transient voltage input to the ESD protection device in transient analysis. A voltage as high as 2000 V is applied instantly to check the function of the ESD protection device. In the total current transient characteristic comparison 134 , the total current transient characteristic measured by conducting current through two ESD protection elements and the current transient characteristic resulting from the simulation of each ESD protection element of the ESD protection device are compared. The parameter for the current ratio is set such that the total current transient characteristic is substantially equal to the measured total current transient characteristic. For example, the parameter for the current ratio is the resistance of wiring to the ESD protection elements. The ratio of currents through the ESD protection elements is changed by adjusting the pMOS wiring resistance 320 or nMOS wiring resistance 322 in FIG. 9 or adding a resistor.
[0085] FIG. 11 shows the comparison between the current transient characteristic of the ESD protection device with the parameter set and the measured current transient characteristic of the ESD protection characteristic. Fitting or adjustment is made for three current transient characteristics of currents through the pMOS, nMOS, and two MOSFET. The resultant transient characteristics are satisfactorily close to the measured transient characteristics.
[0086] Similarly to the total current transient characteristic comparison 134 , the current branching rate comparison 136 is used to set the paramour by comparing the current branching rate measured by conducting current through two ESD protection elements and the simulated current branching rate of the respective ESD protection elements. The parameter for the current ratio is set such that the current branching rate for the respective ESD protection elements is substantially equal to the measured current branching rate. For example, the parameter for the current ratio is the resistance of wiring of the respecting ESD protection elements. The ratio of currents flowing through the ESD protection device is changed by adjusting the pMOS wiring resistance 320 and the nMOS wiring resistance 322 or adding a resistor to the ESD protection device.
[0087] FIG. 12 shows the comparison between the current branching rate of the thus set ESD protection device and that of the measured ESD protection device. Fitting or adjustment is made for the current branching rate of the pMOS 310 and the nMOS 312 . The resultant transient characteristic is satisfactorily close to the measured one. In the current branching rate comparison 136 , measurement may be made by changing a direct current for each predetermined current interval.
[0088] In the total current transient characteristic comparison 134 and the current branching rate comparison 136 , it is noted that where the two ESD protection elements are an nMOS and a pMOS, when one of them forms the snapback characteristic, the other has a drain bias of the sign opposite to the snapback characteristic, forming a forward characteristic. In this case, too, the parameter is required to meet both the characteristics.
Fourth Embodiment
[0089] In this embodiment, the ESD simulation method 120 of the ESD protection device modeled by the ESD protection device modeling method 110 will be described. The ESD breakdown location or resistance will be predicted.
[0090] FIG. 13 shows a circuit including an ESD protection device to be simulated. The circuit includes a protection circuit 410 for absorbing an ESD surge voltage and an inner circuit 412 to be protected. The protection circuit 410 includes an nMOS 420 as an ESD protection element and the inner circuit has a plurality of MOSFETs 422 . Any circuit structure may be taken for the protection circuit 410 and the inner circuit 412 .
[0091] Prior to change of the production process, an actual device is used to identify the breakdown location. That is, an ESD breakdown is made in the actual device, when the input pulse voltage is measured as a breakdown voltage. Then, in the simulation including the modeled ESD protection device, the simulation breakdown voltage is applied to detect the voltage applied to each MOSFET 422 of the inner circuit. The voltage upon the electrostatic breakdown portion 430 is set as a reference voltage. For example, where the reference voltage is 5 V when 100 V is applied as the breakdown voltage, the ESD resistance of the electrostatic breakdown portion 430 is 5 V.
[0092] Where the production process is changed, when the ESD protection device is modeled with the information about the above simulation kept, a circuit diagram equivalent to the circuit prior to change of the production process is provided. Then, the circuit is used to perform simulation. Where there is any portion that produces a voltage equivalent to the reference voltage of the electrostatic breakdown portion 430 before change of the production process when a predetermined voltage equivalent to the breakdown voltage to the circuit in the simulation after change of the production process is applied, the portion is identified as a breakdown location. The ESD resistance is estimated by investigating the input voltage to the circuit at a time when the electrostatic breakdown portion 430 reaches the above reference voltage (causing the electrostatic breakdown). That is, the input voltage to the circuit when the voltage upon the electrostatic breakdown portion 430 reaches the above reference voltage or 5 V is found and, if it is above the breakdown voltage before change of the production process or 100 V, for example, the ESD resistance is increased.
[0093] Alternatively, the specific element may be replaced by a specific element that is derived from a different point of view. The combination of the snapback characteristic, the current transient characteristic comparison, the total current transient characteristic comparison, the current branching rate comparison may be changed to perform the parameter setting step.
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An ESD protection device modeling method of modeling an electrical characteristic of an electrostatic discharge (ESD) protection device for simulating a circuit that include the ESD protection device, comprising the steps of ( 114 ) setting a parameter of at least one specific element that affects the electrical characteristic of the ESD protection device; and ( 116 ) modeling the electrical characteristic of the ESD protection device with the parameter of the specific element.
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TECHNICAL FIELD
[0001] The present invention relates to a kind of electric iron for eliminating the wrinkles on clothes and some other materials.
BACKGROUND TECHNOLOGY
[0002] For the ironing seat of the existing electric irons, the heating temperature in the area close to the heater on the ironing surface attached to the soleplate is higher than areas away from the heater, due to the structure of the soleplate and the shape of the heater. As a result, the heating temperature on the whole ironing surface is not even. For the existing steam electric irons, the steam flow is irregular too. Thus, it is hard to achieve excellent ironing effect with the existing electric irons.
SUMMARY OF THE INVENTION
[0003] The purpose of this invention is to resolve the above-mentioned problems and provide a kind of electric iron that is free from the shortcomings of the existing electric irons.
[0004] The following is the technical means of this invention: the electric iron has an ironing seat, which is composed of soleplate, ironing surface on the soleplate, and heater that heats the soleplate; there are dents on the ironing surface of the soleplate where the heater is installed, and the dents are distributed according to the shape of the heater.
[0005] Said dents are radially distributed from the center line of the heater's projection on the ironing surface to one side or both sides of the center line. In response to a direction of the radial distribution, the caliber of the dents changes from big to small, or their depth changes from big to small, or both of them are incorporated.
[0006] The purpose of the said dents is to reduce the contacting area between the ironing surface close to the heater and the clothes or other materials and then reduce the uneven distribution of temperature on the ironing surface, and guide the steam that the steam electric iron sprays thereby resulting to excellent effect of wrinkle elimination. Therefore, each dent may have no less than one pit or groove, or a combination of pit and groove.
[0007] This invention, with the said structure, reduces the contacting area between the ironing surface close to the heater and the clothes or other materials, thus effectively changing the uneven distribution of temperature on the ironing surface. Further, for steam electric iron, the steam sprayed out of the steam outlets in the soleplate spreads to areas away from the heater through the dents, resulting to excellent effect of wrinkle elimination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows the cutaway view of the ironing seat of the electric iron in Embodiment 1 of this invention;
[0009] FIG. 2 shows the planform of the ironing seat of the electric iron in Embodiment 1 of this invention;
[0010] FIG. 3 shows the bottom view of the ironing seat of the electric iron in Embodiment 1 of this invention;
[0011] FIG. 4 shows the A-A cutaway view of FIG. 3 ;
[0012] FIG. 5 shows the bottom view of the ironing seat of the electric iron in Embodiment 2 of this invention;
[0013] FIG. 6 shows B-B cutaway view of FIG. 5 ;
[0014] FIG. 7 shows the bottom view of the ironing seat of the electric iron in Embodiment 3 of this invention;
[0015] FIG. 8 shows the C-C cutaway view of FIG. 7 ;
[0016] FIG. 9 shows the bottom view of the ironing seat of the electric iron in Embodiment 4 of this invention;
[0017] FIG. 10 shows the D-D cutaway view of FIG. 9 ;
[0018] FIG. 11 shows the bottom view of the ironing seat of the electric iron in Embodiment 5 of this invention;
[0019] FIG. 12 shows the E-E cutaway view of FIG. 11 ;
[0020] FIG. 13 shows the bottom view of the ironing seat of the electric iron in Embodiment 6 of this invention;
[0021] FIG. 14 shows the F-F cutaway view of FIG. 13 ;
[0022] FIG. 15 shows the bottom view of the ironing seat of the electric iron in Embodiment 7 of this invention;
[0023] FIG. 16 shows the G-G cutaway view of FIG. 15 ;
[0024] FIG. 17 shows the bottom view of the ironing seat of the electric iron in Embodiment 8 of this invention;
[0025] FIG. 18 shows the H-H cutaway view of FIG. 17 ;
[0026] FIG. 19 shows the bottom view of the ironing seat of the electric iron in Embodiment 9 of this invention;
[0027] FIG. 20 shows the I-I cutaway view of FIG. 19 ;
[0028] FIG. 21 shows the bottom view of the ironing seat of the electric iron in Embodiment 10 of this invention; and
[0029] FIG. 22 shows the J-J cutaway view of FIG. 21 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Below are further explanations of this invention with the attached Drawing and embodiments.
Embodiment 1
[0031] As FIGS. 1-4 show, the Ironing seat 1 of this invention is composed of the Soleplate 3 , which is heated by Heater 2 , and the Cover 4 , which covers the Soleplate 3 . The Heater 2 is embedded in the aluminum Soleplate 3 with outstanding heat conductivity when it is molded. The surface of Soleplate 3 is a curved face, which forms the Ironing Surface 5 after polishing and treatment with fluoresin coating. In the Ironing Surface 5 , there are multiple Steam outlets 6 and multiple dents along the embedded Heater 2 and with the Steam outlets 6 and dents arranged in similar to the shape of the Heater 2 . Each dent is composed of a group of pits, which include three pits 7 . Each group of pits is aligned in line with a Steam outlet 6 , and are radially distributed from the center line of the heater's projection on the ironing surface to the inside of the center line, namely, the central area of the ironing surface. Meanwhile, the caliber and depth of the pits change from big to small (W1>W2>W3). The caliber of the pit on the center of the heater's projection has the biggest caliber and depth. There is no pit in the center and rear end of the ironing surface along the predetermined length in the longitudinal direction of the electric iron. Also, the rear end part has a dent-free area where there is no pit across a full width of the ironing surface.
[0032] In one of the examples, dimensions of the W1, W2 and W3 are 4.5 mm, 3.5 mm and 2.5 mm respectively; each dent is arranged with a pitch of 6 mm; and a distance between the center line of the heater's projection on the ironing surface and the smallest pit is 12 mm.
[0033] The steam chamber 8 on the soleplate evaporates the water from the water tank (not shown in the drawing) above the Ironing seat 1 and produces steam. The Steam chamber 8 is covered with Cover 4 , and the steam that the Steam chamber 8 produces sprays out of the steam outlet. Since the Ironing Surface 5 is a curved face, there is a gap between the Ironing Surface and the cloth. Thus, after spraying out of Steam outlet 6 , the steam can enter the dents easily and will spread to the central area of the ironing surface along the dents (each group of pits). When the steam enters the pits, the Ironing Surface 5 can move smoothly. When the Heater 2 is electrified, it heats and the temperature of the ironing surface rises. The pits reduce the contacting surface between the ironing surface close to the heater and clothes. There is not any pit in the central area and the rear end of the ironing surface, which is away from the heater. As mentioned above, a volume and an inner-surface area of the part near the Heater 2 of the dent in which air and steam having a lower temperature than that of the Ironing Surface 5 can be accumulated are enlarged or a projection area on the Ironing Surface 5 of the part near the Heater 2 of the dent is enlarged. Thus, the temperature on the whole ironing surface is roughly even. By providing the dents, the steam which escapes out of the Ironing Surface 5 immediately if there are no dents on the ironing surface can be held within the dents. Therefore, portions of the cloth corresponding to the dents are fully swelled, and the dents can enhance the effect of wrinkle elimination. Further since the dents do not exist at the central part and the rear end of the ironing surface 5 , the central part and the rear end can press the cloth strongly. Thus, the cloth can fully be dried and finished without wrinkle. At this time, since there are a plurality of rows of the dents and they are formed from big to small as mentioned above, the amount of steam held in the dents can be decreased gradually. Also, since there are no dents at the rear end part, which puts the finishing touches to the cloth in the ironing, of the ironing surface 5 , the rear end part contributes to making the cloth fully dry and finishing the cloth smoothly. As a result, the smoothness of the ironing surface and the effect of wrinkle elimination can be improved.
Embodiment 2
[0034] FIG. 5 and FIG. 6 show the ironing seat of a dry electric iron. Heater 2 is buried in Soleplate 3 , whose surface forms Ironing Surface 5 . There are multiple dents on the Ironing Surface 5 where the heater is embedded, and each dent is composed of a group of pits, which include four pits 7 . Each group of pits is radially distributed from the center line of the heater's projection on the ironing surface to both sides of the center line of the heater's projection. Meanwhile, the caliber and depth of the pits change from big to small (W1>W2>W3). The caliber of the pit in the heater's projection center has the biggest caliber and depth. There is no any pit in the center and rear end of the ironing surface along the predetermined length in the longitudinal direction of the electric iron. Also, the rear end part has a dent-free area where there is no pit across a full width of the ironing surface.
[0035] Other effects of this embodiment are similar to those of Embodiment 1.
Embodiment 3
[0036] As FIG. 7 and FIG. 8 show, Heater 2 is buried in Soleplate 3 , whose surface forms Ironing Surface 5 . Soleplate 3 is covered with Cover 4 . There are multiple Steam outlets 6 and multiple dents on the Ironing Surface 5 where the heater is embedded, and each dent is a Groove 9 . Each Groove 9 is aligned with a Steam outlet 6 , and extends radially from the center line of the heater's projection on the ironing surface to the inside of the heater's projection center line, namely, the central area of the ironing surface. Their caliber and depth change from big to small (W1>W2). Other structures of this embodiment are similar to those of Embodiment 1.
[0037] The Groove 9 reduces the contacting area between the ironing surface and clothes, and spreads steam to the center of the ironing surface. Flow of steam in the groove enables the ironing surface to move smoothly, to achieve the effects of Embodiment 1.
Embodiment 4
[0038] FIG. 9 and FIG. 10 show the ironing seat of a dry electric iron. Different from Embodiment 3, it doesn't have steam chamber cap (cover), steam chamber or steam outlet. On the Ironing Surface 5 on Soleplate 3 where the heater is embedded, there are multiple Grooves 9 . Each Groove 9 extends radially from the center line of the heater's projection on the ironing surface to the inside of the center line of the heater's projection, namely, the central area of the ironing surface. Their caliber and depth change from big to small. There are pits 7 corresponding to each Grooves 9 . Compared with the Grooves 9 in the center of the heater's projection, pits 7 have smaller mouth width and depth. Other structures of this embodiment are similar to those of Embodiment 2.
[0039] The effects of this embodiment are similar to those of Embodiment 2.
Embodiment 5
[0040] FIG. 11 and FIG. 12 show the ironing seat of a dry electric iron. Different from Embodiment 4, there are not any pits outside the center line of the heater's projection on the ironing surface. Other structures are similar to those of Embodiment 4.
[0041] The effects of this embodiment are similar to those of Embodiment 4.
Embodiment 6
[0042] As FIGS. 13 and 14 show, Heater 2 is buried in the central part of Soleplate 3 . There are multiple Steam outlets 6 and multiple dents on the Ironing Surface 5 where the heater is embedded, and each dent is composed of a group of pits, which include three pits 7 . Each group of pits is aligned with a Steam outlet 6 , and extends radially from the center line of the heater's projection on the ironing surface to the outside of the center line, namely, the marginal area of the ironing surface. Their caliber and depth change from big to small (W1>W2>W3). The caliber of the pit in the center of the heater's projection has the biggest caliber and depth. Other structures of this embodiment are similar to those of Embodiment 1.
[0043] The steam outlets and dent pits close to the heater on the ironing surface reduce the contacting area between the high-temperature ironing surface and clothes. Further, the steam spreads outwards from the pits, enabling the ironing surface to move smoothly, thus achieving the same effects with those of Embodiment 1.
Embodiment 7
[0044] FIG. 15 and FIG. 16 show the ironing seat of a dry electric iron. Heater 2 is buried in the central part of Soleplate 3 , whose surface forms Ironing Surface 5 . There are multiple dents on the Ironing Surface 5 where the heater is embedded, and each dent is composed of a group of pits, which include four pits 7 . Each group of pits is radially distributed from the center line of the heater's projection on the ironing surface to both sides of the center line. Meanwhile, the caliber and depth of the pits change from big to small (W1>W2>W3). The caliber of the pit in the center of the heater's projection has the biggest caliber and depth.
[0045] The effects of this embodiment are similar to those of Embodiment 1.
Embodiment 8
[0046] As FIG. 17 and FIG. 18 show, Heater 2 is buried in the central part of Soleplate 3 , whose surface forms Ironing Surface 5 . There are multiple Steam outlets 6 and multiple Grooves 9 on the Ironing Surface 5 where the heater is embedded, and each Groove 9 is aligned with a Steam outlet 6 , and extend radially from the center line of the heater's projection on the ironing surface to the outside of the center line, namely, the marginal area of the ironing surface. Their caliber and depth change from big to small. Other structures of this embodiment are similar to those of Embodiment 6.
[0047] The grooves close to the heater on the ironing surface reduce the contacting area between the high-temperature ironing surface and clothes. Further, the grooves enable steam to spread outwards, making the ironing surface to move smoothly, thus achieving the same effects with those of Embodiment 1.
Embodiment 9
[0048] FIG. 19 and FIG. 20 show the ironing seat of a dry electric iron. Heater 2 is buried in the central part of Soleplate 3 , whose surface forms Ironing Surface 5 . There are multiple Grooves 9 on the Ironing Surface 5 where the heater is embedded, and each Groove 9 extend radially from the center line of the heater's projection on the ironing surface to the outside of the center line, namely, the marginal area of the ironing surface. Their caliber and depth change from big to small. Inside the said center line of the heater's projection, there shall be pit 7 corresponding to Groove 9 . Compared with the Grooves 9 in the central part, pits 7 have smaller mouth width and depth.
[0049] The effects of this embodiment are similar to those of Embodiment 1.
Embodiment 10
[0050] FIG. 21 and FIG. 22 show the ironing seat of a dry electric iron. Different from Embodiment 9, there is not any pit inside the center line of projection of the heater on the ironing surface. Others are the same with those of Embodiment 9.
[0051] It is to be noted that, by properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced.
[0052] Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
[0053] The entire disclosure of Chinese Patent Application No. 200410077466.8 filed on Dec. 20, 2004, including specification, claims, drawings, and summary are incorporated herein by reference in its entirety.
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This invention relates a kind of electric iron for eliminating the wrinkles on clothes and some other materials. The electric iron has an ironing seat, which is composed of soleplate, ironing surface on the soleplate, and heater that heats the soleplate. There are heater-shaped dents on the ironing surface where the heater is installed. This invention, with the said structure, reduces the contacting area between the ironing surface close to the heater and the clothes or other materials, thus effectively changing the uneven distribution of temperature on the ironing surface. Further, for steam electric iron, the steam sprayed out of the steam outlets in the soleplate spreads to areas away from the heater through the dents, resulting to excellent effect of wrinkle elimination.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to the creation of a holographic media display system that combines physical media or digitally stored files with a digital holographic player hardware system. The result is the creation of a compact and portable multimedia holographic viewing experience.
[0003] 2. Background Art
[0004] A hologram is a microscopic pattern of interference fringes, representing an interaction of two beams of coherent light. Therefore, the hologram is a photographic registration of the interference pattern formed by the two beams, with one of the beams consisting of scattered light from a physical object. Once properly illuminated, the hologram may produce a three dimensional image of the physical object. In recent years, a great deal of effort has been put forth towards developing displays using holography techniques.
[0005] FIGS. 1A and 1B depict a side and top view, respectively, of an example of a holographic film printing process. A coherent light source 101 , or laser, provides a pulsed beam 103 . The pulsed beam 103 is then split into two identical beams, an object beam 109 and a reference beam 107 , via a beam splitting cube 105 . The object beam 109 is then deflected, via a mirror 111 , onto a beam expander consisting of a lens 113 and an aperture 11 5 . The resultant diverging beam 117 is then sent through an optical system 119 , which is used to maintain a uniform intensity across the planes of coherent light 121 , at which the object will be placed. In the present example, the object is a frame from a movie film 123 . The film 123 may be held in place by transparent plates 127 and 125 . An anti-reflection exit surface 134 may be used to reduce reflections,
[0006] Once the object beam 121 has passed through the film 123 , a modified object beam 129 will be emitted through the anti-reflection exit surface 134 . The modified object beam 129 carries imagining information of the object. The modified object beam 129 is then directed towards a photosensitive hologram detector strip 141 . The photosensitive hologram detector 141 is placed behind a mask 143 and is enclosed by transparent members 137 and 139 .
[0007] The modified object beam 129 is combined, or interfered, with a diverging reference beam 135 at an aperture 145 of the mask 143 . The diverging reference beam 135 is obtained by directing the reference beam 107 through a lens 131 . The lens 131 brings the beam to a point focus in an aperture 133 resulting in the divergence. The interference of the diverging reference beam 135 and the modified object beam 129 , at a finite angle θ, forms a holographic pattern time the coherent light source 101 is pulsed. Therefore, for every pulse of the laser 101 , a single movie frame may be recorded as a single holographic image.
[0008] An electronic control 147 may be used to advance the movie film 123 with the use of a motor 149 and rollers 153 . The electronic control 147 may also be used to advance the photosensitive hologram detector strip 141 with the use of a motor 151 and rollers 155 . Synchronization of the laser pulsing, the advancement of the movie film 123 , and the photosensitive hologram detector strip 141 may also be achieved via the electronic control 147 .
[0009] FIG. 2 provides an illustrative example of a portion of the photosensitive hologram detector 200 . The detector comprises a strip 241 (or 141 in FIGS. 1A , 1 B) consisting of a number of rows. Each row, for example row 201 , comprises a single hologram representing a movie frame. The hologram comprises luminance information as well as color information used in the image reconstruction process.
[0010] FIG. 3A depicts a hologram display apparatus 300 . A converging coherent beam 301 is passed through an aperture 303 onto the holographic detector strip 341 at a reconstruction angle θ. In holographic reconstructions, the same laser and angle employed for the recording process, is typically used. The illumination of the holographic detector strip 341 results in the reconstruction of two images, a luminance signal image 307 and a color signal image 305 . Two raster scan type image detecting tubes 309 and 311 are positioned to receive the signals 305 and 307 , respectively. The detecting tubes produce time varying electrical signal outputs based on the signals 305 and 307 . Bandpass filters 315 , 319 , and 323 allow for the transmission of blue, red, and green carrier frequency signals, respectively, to pass. The luminance (E y ), blue (E B ), red (E R ), and green (E G ) electrical signal outputs 313 , 317 , 321 , and 325 are then passed on to signal processing devices and eventually sent to a receiver antenna for a two-dimensional display, similar to that of a standard television.
[0011] Other forms of holographic media storage have also been explored, for example, Holographic Versatile Discs (HVD). HVDs are typically used for document storage and allow for the reconstruction of a two-dimensional holographic image. HVD systems are based on an optical disc technology that employs a technique known as collinear holography. In collinear holography two lasers, typically one red and one blue-green, are collimated in a single beam. The blue-green laser reads data encoded as laser interference fringes from a holographic layer near the top of the disc. The red laser has the dual function of being used as a reference beam, as well as to read servo information from a regular CD-style aluminum layer near the bottom. Servo information may be used to monitor the position of the read head over the disc, similar to the head, track, and sector information on a conventional hard disk drive. On a CD or DVD, this servo information is interspersed amongst the data.
[0012] FIG. 3B provides an example of how a HVD holographic media file may be recorded. The top layer of the HVD, or the volumetric recording layer 350 , is the portion of the HVD where the holographic media files 351 are stored. Each media file 351 represents a page of data 352 . As is shown in FIG. 3B , an HVD may store holograms in overlapping patterns, while using the servo information to access a desired page.
[0013] In contrast, a DVD will typically store bits of information side-by-side. An HVD makes use of a thicker recording layer than that of a HVD. The HVD also utilizes almost the entire volume of the disk, instead of just a single thin layer. Therefore, HVD systems may store approximately 200 times the amount of information a DVD is capable of storing.
SUMMARY OF THE INVENTION
[0014] Although many advances have been made in the field of holographic media display systems, currently there are no systems which are capable of continuously displaying three-dimensional images. Current technology does not allow for the display of an entire feature film using three-dimensional imagery.
[0015] Additionally, present holographic display systems do not contemplate a method whereby holographic media can be recorded, easily replicated, and exhibited in a home environment. Currently no system exists that is adaptable to large and small consumer applications. No display systems currently available are capable of using a variety of laser and fixed media sources configured with different laser strengths and lengths. Also, there are no portable systems, or systems capable of larger displays, with size of installation and/or laser strength not being a barrier in the display application.
[0016] Holographic systems may be large in size and spread out over a large broadcasting area, or may be compact enough to fit in spaces smaller than a desk top. In terms of overall size, holographic technology is mainly limited by the size of the individual component parts. The idea of creating a 2-hour feature film, with approximately 432,000 individual frames of film, at a rate of 60 frames per second, in three-dimensional holographic form, has been a daunting task for holographers. Such a feature film would require creating 432,000 holographic plates, representing a respective frame of film, and displaying the plates in order at a rate of 60 plates per second. There are no systems currently available which are capable of withstanding the storage capacity or speed requirements needed to display a three-dimensional feature film.
[0017] Accordingly, a system and method is presented by the present invention wherein tiny holographic plates, each plate comprising data to reconstruct an entire holographic image, are assembled on a single piece of fixed media, or a master holographic media. It should be appreciated that the master holographic media may take any form, for example a disk, square, rectangle, or any other form. The individual holographic plates enable a three-dimensional holographic video experience that can be easily replicated, transportable, and displayed in small or large venues, by holographic players of different sizes and strengths.
[0018] The invention system for storing holographic media may comprise master holographic media, and a plurality of Child Plates arranged on the master holographic media. Each Child Plate may comprise a respective recorded holographic image, the holographic images may be capable of display in a three-dimensional and continuous manner. Generally a “Child Plate” is a segment cut or otherwise annexed from a master or initial hologram photographic plate.
[0019] A Child Plate, of the plurality of Child Plates, may be a portion of a parent holographic plate, wherein the portion may be obtained using a nanotechnology cutting technique. The portion may also be obtained using a punch-out method. Multiple Child Plates copies, comprising a subset of the parent holographic plate data information, may be obtained from the parent holographic plate. Each Child Plate, of the multiple Child Plates, may be removed at an angle of reconstruction and in a similar location on the parent holographic plate. The plurality of Child Plates may also comprise mirrored bottoms.
[0020] The plurality Child Plates may be placed on the master holographic media disk using optical tweezers. The plurality of Child Plates may also be arranged on the master holographic media in a predetermined order. The plurality of Child Plates may be placed on the master holographic media with an adhesive, and/or using a magnetic force. The plurality of Child Plates may also comprise interlocking shapes and may be placed on the master holographic media in a locked arrangement. Each Child Plate, of the plurality of Child Plates, may also be placed in a respective frame, the frame may comprise locator information. Different sections of the plurality of Child Plates may be accessed using a dynamic library link.
[0021] The master holographic media may comprise a Child Plate back-up portion. The master holographic media may also comprise a contact strip, where each Child Plate, of the plurality of Child Plates, may be addressable via the contact strip. The master holographic media may also comprise a storage region for storing non-holographic data, where each Child Plate, of the plurality of Child Plates, may be individually synchronized with the non-holographic data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0023] FIGS. 1A and 1B are side and top views, respectively, of a two dimensional holographic recording process according to the prior art;
[0024] FIG. 2 is a depiction of a holographic film strip according to the prior art;
[0025] FIG. 3A is a schematic of a two-dimensional holographic display system according to the prior art;
[0026] FIG. 3B is an illustrative example of two-dimensional data storage in Holographic Versatile Discs according to the prior art;
[0027] FIG. 4A is a schematic layout of a parent holographic plate according to an embodiment of the present invention;
[0028] FIG. 4B is an illustrative example of Child Plate processing according the present invention;
[0029] FIG. 4C is an illustrative example of Child Plate placement using adhesives according to an embodiment of the invention;
[0030] FIG. 4D is an illustrative example of Child Plate placement using framing technology;
[0031] FIG. 4E is an illustrative example of Child Plate placement using a locking configuration;
[0032] FIG. 5 is an illustrative example of a three-dimensional holographic reading process according to an embodiment of the present invention;
[0033] FIGS. 6A and 6B are schematic illustrations of a holography media player according to an embodiment of the present invention; and
[0034] FIG. 6C is a schematic illustration of the holography media player, of FIGS. 6A and 6B , in a viewing environment according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] A description of example embodiments of the invention follows.
[0036] Once a holographic image has been recorded, illuminating a coherent laser (of the same wavelength and angle of incidence as employed during the recording stage) on any portion of the recorded data will yield a complete three-dimensional reconstruction. Exploiting the fact that the smallest piece of a holographic photo plate will still generate the entire end image hologram, a portable and compact holographic display system may be obtained. The process of generating a moving image at a desired frame rate per second may be achieved by cutting small samples, or Child Plates, from each holographic photo plate, or parent holographic plate, comprising imaging information for the reconstruction of a movie frame. The imaging information may be a subset of the parent holographic plate data information, which may be used for reconstructing the image originally recorded on the parent holographic plate it should be appreciated that “Child Plate” as used herein is a segment cut or otherwise annexed holographic recording from a master hologram photographic plate.
[0037] FIG. 4A shows an example of a parent holographic plate 411 comprising a recorded holographic image. The writing of the parent holographic plate 411 may be achieved real time during the filming of a movie, or may be achieved using a 35 mm film. The writing process may also be achieved via 3 D modeling software. The modeling software may also be used in combination with specific display media. The display media, such as LCD or liquid background, may be used to accentuate the images dimensionality and may also incorporate real time modeling, such as the kind used in stop frame animation.
[0038] A fusion of these techniques can also be used to incorporate different source elements and visual effects common in feature films and television programming. It should be appreciated that any holographic writing method known in the art may be employed in the present invention, for example the methods shown in FIGS. 1A and 1B .
[0039] Once a holographic recording has been obtained, holographic media, or Child Plates 401 , may be culled from the parent holographic plate. The Child Plates 401 may be obtained from the parent holographic plate at very small increments (i.e., in the micron range) using nanolithography cutting tools. The nanolithography cutting tools may be used to slice a tiny sample 401 of the parent holographic plate representing a frame of film, or video. For example, a laser may be employed to cut the Child Plate portions 401 from the parent holographic plate. Utilizing a cutting laser at the same angle as the angle of reconstruction, may improve the accuracy of the image reconstruction. Additionally, removing multiple Child Plates 401 in substantially the same location on the parent holographic plate 411 (i.e., the majority of the Child Plates 413 may be removed from the center of the parent holographic plate 411 ), may also improve image reconstruction accuracy. Preferably each Child Plate 401 is removed substantially from the same location and angle as other Child Plates 401 that will collectively be used to from a master holographic media 400 ( FIG. 4B described below) and in a preferred embodiment is removed from the center of the parent holographic plate 411 so that the laser need only be calibrated to the center of each Child Plate 401 .
[0040] It should be appreciated that any nano-scale technology known in the art may be employed for obtaining the Child Plates from the parent holographic plate 411 . For example, the various Child Plates 401 may be mass manufactured. Employing a “punching” technique, thousands of Child Plates may be obtained simultaneously. Such a technique will allow for easy duplication of the recorded holographic image. Whereas in the prior art holographic media storage (as shown in FIGS. 2 and 3B ), in order to duplicate a recorded holographic image, the entire holographic recording process would have to be repeated (as shown in FIGS. 1A and 1B ).
[0041] FIG. 4B provides an illustrative example of a master holographic media 400 . Once the Child Plate sections 401 have been obtained, they may be placed on the writable area 403 of a master holographic media 400 . The master holographic media 400 may be prepared for recording using any number of methods well known in the art. Typically, a glass surface is treated with gelatin to make it chemically ‘sticky’. The added gelatin layer may then be hardened with chromium or formaldehyde. Once the hardened gelatin film has been established, the film may then have soaked into it a silver salt, and subsequently soaked in potassium or lithium bromide to obtain an ultra-fine grain precipitate of silver bromide. The bromide solution also incorporates a dye to make the plate photo-sensitive in the required wavelength range. A sensitizer may be added to improve the effectiveness of the holographic plate.
[0042] In an example configuration, the master holographic media 400 may comprise a size dimension of 10 cm by 20 cm. This size dimension would be capable of carrying approximately 432,000 individual Child Plates. This example size dimension may be capable of storing an entire feature film, an index, table of contents, as well as a start and navigation system for the stored media elements.
[0043] The different sections of the media may be tied to dynamic link library (DLL) actions in the hardware enabling the viewer to control settings, and the table of content commands from the media directory passed through to the hardware. It should be appreciated that any dimensions may be used in the fabrication of the master holographic media 400 . For example, the dimensions may be increased if it was desired to include more information on the disk.
[0044] A strip 407 on the master holographic media 400 is used as a contact point that allows for a transfer of information when downloaded to a hard drive. Each Child Plate 401 may be accessed via the strip 407 with the use of software coding (e.g., SMPTES). A strip 405 may be used for flash memory storage. The flash memory may be used to store audio files which may be synchronized with the individual Child Plates via software coding (e.g., SMPTE).
[0045] One technique which may be used in Child Plate 401 placement is optical trapping. Optical trapping makes use of optical, or laser, tweezers. Once light interacts with an object and undergoes changes in direction, due to reflection or refraction, a change in the light's momentum will occur. Due to the laws of physics, the object must undergo an equal and opposite momentum change. The object's momentum change results in a radiation force acting on the object. The radiation force comprises a scattering force along the direction of light propagation, and a gradient force due to the light intensity distribution around the object.
[0046] An optical trap may be created when a laser beam is focused to a small spot with a high numeric aperture (NA) microscope objective lens. Since the light intensity at the center is greater than that at the edges, the gradient force drives the object positioned within the laser focal point toward the central point. Meanwhile, scattering force may act to push the particle out of the center, along the direction in which the light is traveling. If the gradient forces caused by refracted light are greater than the scattering forces caused by reflected light, the net effect with be a force which holds the particle in the center of the beam. Thus, a stable optical trap is obtained.
[0047] Holographic optical trapping (HOT) may also be employed as a technique for Child Plate placement. HOT comprises replacing the single focused laser beam with a spatial light modulator. The spatial light modulator may enable the light, from a single laser beam, to be sculpted into as many as 200 independently controllable optical tweezers. The optical tweezers may be positioned and moved in three directions. It should be appreciated that any nano-scale movement technique known in the art may be employed in the placement of Child Plates 401 .
[0048] During the placement process, each Child Plate 401 may be aligned side by side onto the master holographic media 400 writable area 403 , and set into place with the use of an adhesive, as shown in FIG. 4C . Alternatively, each Child Plate 401 may be placed in a thin a tiny brace, or frame 402 , as shown in FIG. 4D . The individual frames 402 may be adhered to each other forming a single frame set 406 . This process creates a frame between each Child Plate 401 . The individual frames 402 may also comprise locator information 404 on the side of the frame. The locator information 404 may be used during the reading process of the Child Plates 401 . The Child Plates 401 may also be bonded by magnetic forces, or adhesives, surfaces along the master holographic media 400 , or between the Child Plates 401 and frames 402 . The frame 402 may be comprised of metal, carbon, glass, polymer, or any other durable material allowing for the master holographic media to easily slide into a holographic player.
[0049] Additionally, the Child Plates 401 may be cut into interlocking shapes and placed in a locked arrangement, as is shown in FIG. 4E . It should be appreciated that any other form of placement or adhesion known in the art may be employed. It should be appreciated that although FIG. 4B only displays three Child Plates 401 , the entire writable area 403 may be used in the placement of the Child Plates 401 . Therefore, any number of Child Plates 401 may be placed in order to reconstruct the feature film.
[0050] The Child Plates 401 may be placed in a sequential order, or the Child Plates 401 may be placed in a predetermined order. Placing the Child Plates 401 in a predetermined order may allow for the use of tag and read systems, automated gates, programmable laser positioning, or any other read access method. The Child Plates 401 may also be placed in a consecutive ordering, wherein the Child Plates are aligned in relation to the sequence in which they are expected to be imaged or illuminated.
[0051] Once the Child Plates 401 have been established, an efficient read access method may be used. A typically feature film requires a reading rate of approximately 60 frames per second, with the average movie or any media/content production consisting of approximately 2 hours worth of data. The total number of Child Plates 401 required for this type of data would be approximately 432,000. The master holographic media 400 is capable of storing an entire feature film, and displaying this film as a true three-dimensional holographic image.
[0052] FIG. 5 depicts an example of a master holographic media reading. A laser 503 may be used to direct a coherent laser beam 504 , similar to the reference beam used during the writing process, onto an individual Child Plate 401 on the master holographic media 400 . The recorded hologram on the Child Plate 401 diffracts the beam according to the specific pattern of light inference stored on the Child Plate. The resulting light recreates the holographic image 505 of the film frame that established the light interference pattern in the first place. A light sensor may be used to detect and amplify the holographic image 505 .
[0053] In operation, a laser may move among the Child Plates 401 on the master holographic media 400 in a programmed consecutive or non-consecutive order illuminating each proscribed Child Plate at a proscribed frame rate. As an example, the master holographic media 400 , which may be the size of a baseball card, may be calibrated to move one frame increment at a rate of 60 Child Plate frames per second. The incrementing of the master holographic media 400 may be performed so that the path of the laser, which may or may not pulse between frames to remove blurring, illuminates the Child Plates 401 without moving the laser. Stabilizing the laser may help reduce reading errors.
[0054] In a stable laser configuration, the individual Child Plates 401 may comprise a see through or mirrored bottom. The laser may be positioned to illuminate the Child Plate 401 with a beam perpendicular to the surface of the plate 401 , with each of the mirrored bottoms being positioned to the reconstruction angle. This configuration may be ideal for reading systems comprising stable, or non-moving, lasers. Thus, the laser system does not need to be recalibrated for each master holographic media 400 , since the required angel for illumination is supplied via the mirrored bottoms of the individual Child Plates 401 . Therefore, the master holographic media 400 may simply move incrementally into place, with the laser 503 illuminating each Child Plate 401 at the necessary speed and at the necessary time.
[0055] Alternatively, the laser 503 may move incrementally into place while the master holographic media 400 remains stationary, or the master holographic media 400 may also move incrementally in place. Multiple lasers may also be employed in the reading of the various Child Plates 401 .
[0056] The master holographic media 400 may also comprise a backup system on the disk in the event that a Child Plate 401 is damaged. A section of the master holographic media 400 may be used to supply duplicate Child Plates 507 in the event a Child Plate 401 is damaged or lost. A scanner may be used to automatically scan the surface of the individual Child Plates 401 . In the event that a defect in one of the Child Plates 401 is detected, the DLL may be programmed to move the laser 503 , or disk 400 , to skip the damaged Child Plate 401 . Instead of imaging the damaged Child Plate, the laser may instead illuminate the backup image of the corresponding duplicate Child Plate 507 .
[0057] Multiple laser reading techniques may be employed on each Child Plate to enable greater coloration, and/or depth and dimensionality of the images. (rated sequential access using programmed position or tag and read systems, for example wi-fi, may be used as Child Plate accessing techniques as well. Specifically, in a configuration where each Child Plate has a laser trained upon it, for example via use of mirrored refraction and reflection of lasers, or with the use of multiple lasers, an automated gate may be employed to allow only the Child Plate in sequence to have a window opened in the gate.
[0058] Labeling techniques may also be employed in a reading scheme, for example with the use of frame locators 404 . The frame system may also be used in the communication with a holographic player CPU and software. For example, if a user wishes to skip to a certain scene, or Child Plate 401 , of the feature film, the frame system may be utilized to navigate the laser read system. Additionally, microwave transmissions or RFID tagging systems may allow the laser to read non-sequentially placed Child Plates in sequential order.
[0059] As mentioned before, the angle the laser illuminates the Child Plates 401 in the prepared master holographic media 400 is preferably the same angle that the Child Plates 401 were taken from the original parent holographic plate 411 in FIG. 4A . This maximizes accurate image reproduction.
[0060] FIGS. 6A and 6B depict a holography disk player 600 used in the reading and displaying of information stored on the master holographic media 400 . The player 600 comprises a slot 607 used in the insertion of the master holographic media 400 . The holographic player 600 may further comprise a microprocessor 609 , or semiconductor chip, employed in the reading and displaying process. For example, microprocessor 609 executes programmed ready sequence, Child Plate 401 failure recovery and the other ready/access features detailed above. Micro-mirror projectors 611 , utilizing digital light processing (DLP) technology, are used to project the three-dimensional holographic image 613 .
[0061] FIG. 6C provides an illustrative example of how the three-dimensional holographic image 613 may be viewed in a home environment. The image of the holographic media projects as a continuous hologram. The hologram may be augmented by overhead, backlighting or side lighting using halogen or other illuminating techniques. White or black backgrounds may also be mounted in the holographic area. The distance of the laser of up to 1.5 meters away from the Child Plates or any closer distance may be achieved to maximize the holographic players' efficiency. Multiple lasers may be used to augment images or image components such as brightening/sharpening colors, reducing fringe, speckle and other forms of laser distortion of the image. The size of the image shall be a correlation between the original holographic plate images, and the size and accuracy of the laser in the holographic player, along with the hologram image quality of the individual Child Plate.
[0062] Confirming with FIG. 6A , holography disk paper 600 is powered through conventional power source 603 or other power sources. A networked computer 605 may provide further program instructions for ready master holographic media 400 as described above.
[0063] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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A master holographic media storing large quantities of holographic media is disclosed. Holographic images may be recorded onto individual Child Plates. A Child Plate may be obtained by culling a portion of a starting or working parent holographic plate with the Child Plate portion comprising all the necessary data required for holographic image reconstruction. A series of plurality of Child Plates are arranged on and compiled to the master holographic media. The resulting information stored on the master holographic media is capable of being displayed as a continuous three-dimensional holographic image.
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ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 U.S.C. Section 202) in which the Contractor has elected not to retain title.
This application is a continuation of U.S. application Ser. No. 07/677,070, filed Mar. 29, 1991, now abandoned.
TECHNICAL FIELD
The subject invention relates generally to film deposition processes and systems and, more particularly, to an improved diamond-like film deposition process and system.
BACKGROUND ART
Amorphous hydrogenated carbon (a-C:H) films have been deposited using a variety of chemical vapor deposition (CVD) techniques wherein a chemical process taking place in the vapor phase of the gas next to the substrate causes the reaction product to be deposited. One prior art technique involves placing a substrate for deposition in a reaction chamber and heating the substrate to a temperature of 800° C. to 1000° C. Hydrogen gas is then fed into the reaction chamber, and microwave power is applied at 1 kilowatt with a frequency of 2.45 GHz. A magnetic field of about 2000 Gauss is simultaneously applied to the reaction chamber for forming an electron cyclotron resonance condition in the reaction chamber so that the plasma electrons will be caused to orbit the magnetic field at a resonant frequency and trap or confine the plasma ions.
A carbon compound gas, that acts as a catalyst, is introduced into the reaction chamber at a relatively high pressure of up to 760 Torr. The catalytic gas, in combination with the magnetic field and microwave power, allows a hard carbon film to be formed on a substrate disposed in the reaction chamber.
A disadvantage of this method is that catalytic gases containing minerals such as nickel, manganese, or germanium must be introduced into the system to be used as a catalyst. Another disadvantage is that heat sensitive substrates, such as plastic, are unable to withstand these high temperatures. The discussed method is disclosed in U.S. Pat. No. 4,871,581, by S. Yamazaki.
A similar prior art method of depositing diamond-like films on a substrate is disclosed in U.S. Pat. No. 4,935,303, by Ikoma et al. In the disclosed method, a first magnetic field of 1300 Gauss is applied to a plasma producing chamber, and a second magnetic field of 875 Gauss is applied near the surface of a substrate. The substrate is maintained at a temperature between 350° C. and 700° C., with 580° C. being preferred. If the substrate is not maintained above 350° C., a diamond-like film may not form on the substrate. If a film is formed, the hydrogen content was excessively high and the film is too low in density, resulting in low chemical and structural stability.
Again, a disadvantage to the above method, is the inability to form diamond-like films on substrates at temperatures less than 350° C. Another disadvantage of the method is its requirement of a substantially strong magnetic field.
Accordingly, a method of depositing films, with such properties as extreme hardness, optical transparency, and chemical inertness, onto substrates that are heat sensitive, would be a solution to these problems.
STATEMENT OF THE INVENTION
It is therefore an object of the present invention to provide a method of depositing diamond-like films onto a substrate;
It is another object of the present invention to provide a method for depositing diamond-like films onto heat-sensitive substrates;
It is another object of the present invention to provide a method for depositing diamond-like films on irregularly-shaped substrates;
It is another object of the present invention to provide a deposition method capable of operating at ambient temperature; and
It is another object of the present invention to provide an improved electron cyclotron resonance deposition system.
These and other objects and advantages of the present invention are achieved by providing an electron cyclotron resonance plasma deposition system having radio frequency (RF) power applied to a sample stage disposed in the deposition chamber. The radio frequency (RF) power applied to the sample stage during the invented method induces a negative self-bias voltage in the sample stage, enabling various diamond-like films to be very easily formed on a substrate mounted on the sample stage. During the deposition process, no external heat is applied to the sample stage, to maintain the sample stage at an ambient temperature of less than 100° C.
In the preferred embodiment, when a low RF power bias is applied to the sample stage, a high negative, self-bias voltage of approximately -100 volts is induced in the sample stage for forming a desired diamond-like film on the substrate. One advantage of this system is that, when the low energy ions of the electron cyclotron resonance (ECR) plasma are impinging onto the substrate, with the high negative self-bias voltage induced in the sample stage, a diamond-like film having a Raman spectrum consisting of broad and overlapping graphitic D (1360 cm -1 ) and graphitic G (1590 cm -1 ) lines may be formed on the substrate.
When a high RF power bias is applied to the sample stage, a low negative self-bias voltage of approximately -3 volts is induced in the sample stage. This results in a diamond-like film having a broad Raman peak centered at approximately 1500 cm -1 being formed on the substrate.
In the invented deposition process of the present invention, the substrate is maintained at ambient temperatures of less than 100° C. during the deposition process. This ambient temperature deposition process enables heat-sensitive substrates, such as plastic, to be coated with diamond-like films. Three-dimensional substrates and other irregular substrates, such as those used in microelectronics and optics, can also be coated with diamond-like films using the invented process and accompanying system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention, both as to its organization and manner of operation, together with further objects and advantages, may be understood by reference to the accompanying drawings.
FIG. 1 is a perspective view, partially shown in phantom, of an electron cyclotron resonance deposition system incorporating the preferred embodiment of the present invention;
FIG. 2 is a cross-sectional plan view of the preferred embodiment;
FIGS. 3A and 3B are graphical representations of Raman spectra obtained from diamond-like films formed on substrates using the preferred method of the present invention;
FIG. 4 is a graphical illustration of Tauc plots for the diamond-like films formed using the preferred method; and
FIG. 5 is a graphical illustration of varying magnetic field profiles used in the preferred method.
DETAILED DESCRIPTION OF THE INVENTION
The following description is provided to enable any person skilled in the plasma deposition art to make and use the invention, and sets forth the best modes contemplating by the inventors for carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in these arts.
With reference to FIGS. 1 and 2, there is shown an electron cyclotron resonance (ECR) deposition system 10 according to the preferred embodiment of the present invention. A cylindrical plasma chamber 12 has a top 14 and a bottom 16. The bottom 16 has an aperture 18 disposed through the bottom's center. A rectangular waveguide 20 is connected between a microwave power source 21 and the plasma chamber 12. The waveguide 20 connects to the plasma chamber's top 14 through a quartz window 24.
Two annular magnetic coaxial coils 26, 28 are disposed around the outer periphery of the plasma chamber 12. In the embodied structure, the magnetic coils 26, 28 are disposed parallel to one another with a distance D 1 between their center regions of approximately 33 cm. A power source 27 supplies power to the magnetic coils 26, 28 for supplying a confining magnetic field to the plasma chamber 12, in a magnetic-mirror configuration.
An electron resonance condition is set up at the upper portion of the plasma chamber 12 by the top magnetic coil 26 generating a magnetic field of approximately 875 Gauss. A divergent magnetic field profile is set up by the bottom magnetic coil 28 generating a smaller, variable magnetic field, to extract electron cyclotron resonance (ECR) plasma, when formed, into a cylindrical deposition chamber 30 connected to the plasma chamber's bottom 16.
The magnetic-mirror configuration may be manipulated to extract specific plasma ion energies during the deposition process. The energy profile of the plasma ions extracted from a confinement region, located between the two magnetic coils 26, 28 in the plasma chamber 12, is dependent on the magnetic field strength and the voltage potential difference between generated plasma and a sample stage 42.
A first tube 32 is used to transfer a plasma generation gas, such as hydrogen (H 2 ), from a storage tank 34 to an annular distribution manifold 36. The annular distribution manifold 36 has a plurality of inlet tubes 38 that extend into the plasma chamber's top 14 for disbursing the plasma generation gas into the plasma chamber 12.
A cylindrical can 46 is mounted in the deposition chamber 30 for positioning a substrate stage 40 in the deposition chamber 30. The substrate stage 40 includes a sample stage 42 which may be stainless steel, and a substrate 44 mounted on the sample stage 42. The substrate 44 should be positioned approximately 15 cm from the aperture 18. The can 46 may be stainless steel and be approximately 15 cm in height and 14 cm in diameter. A plurality of cylindrical electrical isolation posts 48 are used to electrically isolate the substrate stage 40 from the system 10. In the embodied structure, the cylindrical posts 48 may be approximately 1/8-inch in diameter and 3/8-inch in height, and are generally ceramic.
The substrate 44 may be silicon, Dow Corning 7059 optical glass, or quartz, or any other applicable substrate known in the art. The substrate 44 is typically prepared for deposition by known methods in the art, such as first ultrasonically cleaning in an acetone and isopropyl alcohol solution, then rinsing in deionized water. The substrate 44 preparation process may take five minutes.
A second gas transfer tube 50 extends from a gas storage tank 52 into the deposition chamber 30, and finally terminates in a circular gas distribution ring 54. The second tube 50 is used to transfer a reaction gas, such as a suitable hydrocarbon gas, from the storage tank 52 to the circular gas ring 54, for disbursing the reaction gas into the deposition chamber 30. Suitable hydrocarbon gases include methane, acetylene, and propane.
In an alternative embodiment, the reaction gas may be mixed with the plasma generation gas, and the two gases simultaneously disbursed into the plasma chamber 12 through the annular distribution ring 36.
In the preferred embodiment, a radio frequency (RF) generator 56 is connected to the sample stage 42 through an RF matching circuit 70. The RF matching circuit 70 couples to the sample stage 42 through a first vacuum feedthrough 68 disposed in the deposition chamber's wall 72. The sample stage 42 is connected to the vacuum feedthrough 68, using an RF cable 69.
The RF generator 56 provides an RF power bias at approximately 13.56 MHz for inducing a low negative self-bias voltage, of approximately -3 volts in the sample stage 42. For inducing a high negative self-bias voltage of approximately -100 volts in the sample stage 42, an isolating capacitor 58 of about 0.1 μF is connected between the RF matching circuit 70 and feedthrough 68, giving an approximately infinite DC impedance to ground.
The level of induced negative self-bias voltage is measured by a voltmeter 60. The voltmeter 60 is connected to the sample stage 42 through an RF filter 76 and a second vacuum feedthrough 74 disposed in the deposition chamber's wall 72. The sample stage 42 is connected to the second feedthrough 74 using a piece of conductive wire 73.
Different levels of the applied RF power bias accelerates ions of the ECR plasma impinging on the substrate 44. Thus, different diamond-like films are caused to form on the substrate 44 when undergoing deposition processing.
A cooling agent, such as water, is used for cooling the coils 26, 28. The cooling agent is fed from a tank 61, through an input tube 62, after which it passes around the magnetic coils 26, 28 in series, and then exits through tube 66. A cavity 64 is disposed about the outer periphery of the plasma chamber 12. Water in the tank 61 passes through a tube 63 into the cavity 64 and out through an exit tube 65 for cooling the plasma chamber 12.
In operation, the desired substrate 44 is mounted on the sample stage 42. Plasma generation gas is then disbursed into the plasma chamber 12 through the inlet tubes 38. The reaction gas is disposed into the deposition chamber 30 through the gas ring 54. The gases are disbursed into the chambers 12, 30 at a low pressure of 10 -1 to 10 -2 Torr to achieve a high plasma density.
Approximately 360 watts of microwave power is transmitted at approximately 2.45 GHz through the rectangular waveguide 20 and quartz window 24 into the plasma chamber 12. ECR plasma is generated by the microwave power being absorbed by the gases and exciting them, thus fully ionizing the gases. The ion energy of the ECR plasma is approximately 1-5 electron volts. The low ion energy is due to the moderate sheath voltage inherent in a plasma generated by microwave excitation.
The sample stage 42 is biased by applying RF power from the RF generator 56 via the RF matching circuit 70. In the preferred method, the RF generator 56 supplies either 5 watts or 30 watts of RF power to the sample stage 42, depending on whether or not capacitor 58 is present. A large RF power bias may be applied to the sample stage 42 by removing the isolating capacitor 58. This results in an induced DC self-bias voltage of approximately -3 volts in the sample stage 42 during the deposition process. A low RF power bias may be applied to the sample stage 42 by including the capacitor 58. This results in an induced DC self-bias voltage of approximately -100 volts in the sample stage 42 during deposition.
Desired plasma ions are extracted by the magnetic fields, caused by the magnetic coils 26, 28, from the plasma chamber 12 and deposited onto the substrate 44, for forming a desired diamond-like film on the substrate 44. Different diamond-like films may be formed on the substrate 44 in response to RF power bias applied to the sample stage 42, which accelerates the plasma ions impinging on the substrate 44.
With reference to FIGS. 3A, 3B, 4, and 5, a series of tests were conducted to illustrate the advantages of the invented process and system over the prior art. The substrates 44 were positioned approximately 15 cm below the aperture 18. Optical gaps for the formed diamond-like films were obtained from a Tauc relation equation:
(αE).sup.1/2 =B(E-E.sub.g)
where α is an absorption coefficient, E is energy, B is a constant, and E g is the optical gap. The Raman spectra of the diamond-like (a-C:H) films is measured at room temperature with a 514.45 nm line of an argon laser.
Films deposited without an external bias applied to the sample stage 42 show an optical band gap of approximately 2.8 eV and a deposition rate of 2.3 Å/s. These films are mechanically soft and have a broad fluorescence in the spectral range of 450-650 nm. This fluorescence prevented the Raman spectra of these films from being measured.
Substrates 44 deposited with the 13.56 MHz RF external power bias applied to the sample stage 42 in accordance with a preferred method of the invention are shown in FIGS. 3A and 3B. In a first sample, Sample A, substrate 44, was deposited with an applied magnetic field of approximately 875 Gauss and an RF bias of 30 watts applied to the sample stage 42. The 30-watt power bias was applied without the isolating capacitor 58, which resulted in an induced negative DC self-bias voltage of approximately -3 volts to the sample stage 42 during deposition. The ratio of CH 4 to H 2 concentration was 50% at a pressure of 5 mTorr. The deposition rate was approximately 5-6 Å/s. Measurement of the optical gap for the first sample yielded a value of E g =1.4 eV. The Raman spectra of the formed diamond-like film is shown in FIG. 3A.
A second sample substrate 44, Sample B, was deposited with a low RF power bias of 5 watts applied to the sample stage 42, and an applied magnetic field of approximately 875 Gauss. The magnetic field profile 84 for Sample B is shown in FIG. 5. The low RF power bias applied through the isolating capacitor 58 resulted in a large negative DC self-bias voltage of approximately -100 volts in the sample stage 42. The sample film was deposited onto the substrate 44 at a pressure of 17 mTorr and a concentration of 17% CH 4 . This resulted in a deposition rate of 0.5 Å/s.
The lower deposition rate was caused by increased hydrogen ion etching, given the negative bias voltage, and higher hydrogen fraction of the plasma. The optical gap of the second sample was 1.0 eV. The Raman spectra for the second sample is shown in FIG. 3B. The Tauc plots for the deposition process used on Sample A 88 and Sample B 89 substrates 44 are shown in FIG. 4.
A third substrate 44, Sample C, was subjected to a deposition process similar to that of Sample B, except the deposition process was completed with a reduced mirror magnetic field. The mirror magnetic field used during the Sample C deposition process was approximately 500 Gauss. The magnetic field profile 86 for the deposition processes used on Sample C substrate 44 is shown in FIG. 5. The optical gap was found to increase from 1.0 to 1.6 eV.
A fourth substrate 44, Sample D, was deposited with the same parameters as the Sample B deposition process, except at an increased pressure of 55 mTorr. The effect of increasing the deposition pressure was found to decrease the optical gap from 1.6 to 1.2 eV. The Raman spectra of the Samples C and D deposition processes are similar to that of Sample B, as shown in FIG. 3B.
All of the sample deposition processes resulted in amorphous hydrogenated carbon (a-C:H) "diamond-like" films, having a hard diamond-like quality. A comparison of the Raman spectra and optical gaps indicate that more than one hard diamond-like film morphology is present at a given optical gap. Film characteristics were also shown to be dependent on the magnetic field profile used during the deposition process. The results of the sample deposition processes indicate that increasing the energy of the ions incident on the substrate results in an increased optical gap. Use of the RF induced negative self-bias DC voltage of the substrate stage, and manipulation of the magnetic field profile in the ECR microwave plasma system has proven to be an advantageous technique for the deposition of diamond-like films on heat-sensitive substrates.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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Hard amorphous hydrogenated carbon, diamond-like films are deposited using an electron cyclotron resonance microwave plasma with a separate radio frequency power bias applied to a substrate stage. The electron cyclotron resonance microwave plasma yields low deposition pressure and creates ion species otherwise unavailable. A magnetic mirror configuration extracts special ion species from a plasma chamber. Different levels of the radio frequency power bias accelerate the ion species of the ECR plasma impinging on a substrate to form different diamond-like films. During the deposition process, a sample stage is maintained at an ambient temperature of less than 100° C. No external heating is applied to the sample stage. The deposition process enables diamond-like films to be deposited on heat-sensitive substrates.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National stage filing of International Application No. PCT/EP2013/071010, filed 9 Oct. 2013, and claims priority of German application number 10 2012 218 378.7, filed 9 Oct. 2012, the entireties of which applications are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to processes for the production of moldings or sheet materials comprising latent heat accumulators, to the moldings or sheet materials obtainable therefrom, and to use thereof by way of example in the construction industry for the coating of ceilings.
BACKGROUND OF THE INVENTION
Latent heat accumulators are materials which at certain temperatures undergo reversible thermodynamic state changes, for example solid/liquid phase transitions, and extract the associated enthalpy of phase change from the environment and, respectively, release said enthalpy into the environment. Latent heat accumulators can therefore prevent, or at least mitigate, temperature variations in the region of their thermodynamic state change, for example their melting point or freezing point. Examples of commonly used materials that accumulate latent heat are paraffin oils, fatty acids, and fatty waxes. Latent heat accumulators are used in a wide variety of applications: US 2001000517 describes the coating of textiles with materials of this type. U.S. Pat. No. 5,565,132 describes processes in which compositions comprising latent-heat-accumulating material, polymers, and silica particles are processed by way of a melt to give sheets, pellets, or fibers.
However, when latent heat accumulators are present in the liquid phase they are easily released into the environment. A frequent recommendation intended to prevent this is that latent-heat-accumulating material be sheathed with a higher-melting-point material, as described by way of example in US 2011169179A. WO 99/24525 teaches microcapsules in which a capsule wall made of highly crosslinked methacrylic ester polymers surrounds the latent-heat-accumulating material. US 2006272281, U.S. Pat. No. 8,070,876, WO11071402, and US 2011108241A describe the use of microcapsules of that type in construction applications. Another challenge consists in the further processing of these microcapsules to give marketable products, as discussed by way of example in EP1484378. The plastics technology sector makes very wide use of thermoplastic processes. However, a problem arising during the thermoplastic processing of the microcapsules is that a considerable proportion of the microcapsules is easily damaged, with the consequence that when the latent-heat-accumulating material undergoes transition to the liquid phase it can be released from the microcapsules into the environment, with resultant loss of the advantage of the microcapsules. Problems of this type arise by way of example during the thermoplastic processing of compositions which comprise polyurethane casting resins alongside the microcapsules.
SUMMARY OF THE INVENTION
Against this background it was an object to develop novel approaches that permit processing of microcapsules comprising latent heat accumulators to give moldings or sheet materials. A further intention was thus to provide access to moldings or sheet materials which comprise the greatest possible proportion of the microcapsules mentioned. The shape of the moldings or sheet materials, for example layer thicknesses, should be amenable to variation as desired within a wide range.
Surprisingly, when microcapsules comprising latent heat accumulators were processed thermoplastically together with polymers based on ethylenically unsaturated monomers said object was achieved.
The invention provides processes for the production of moldings or sheet materials comprising latent heat accumulators, characterized in that mixtures comprising one or more microcapsules and one or more polymers based on one or more ethylenically unsaturated monomers selected from the group comprising vinyl esters, (meth)acrylic esters, vinylaromatics, olefins, 1,3-dienes, and vinyl halides, where said microcapsules comprise one or more latent heat accumulators, are processed by means of thermoplastic forming techniques.
The invention further provides moldings or sheet materials comprising latent heat accumulators, said moldings or sheet materials being obtainable via thermoplastic forming of mixtures comprising one or more microcapsules, and
one or more polymers based on one or more ethylenically unsaturated monomers selected from the group comprising vinyl esters, (meth)acrylic esters, vinylaromatics, olefins, 1,3-dienes, and vinyl halides, where said microcapsules comprise one or more latent heat accumulators.
DETAILED DESCRIPTION OF THE INVENTION
Examples of suitable vinyl esters are those of carboxylic acids having from 1 to 22 C atoms, in particular from 1 to 12 C atoms. Preference is given to vinyl acetate, vinyl propionate, vinyl butyrate, vinyl-2-ethylhexanoate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl arachinate, 1-methylvinyl acetate, vinyl pivalate, and vinyl esters of α-branched monocarboxylic acids having from 9 to 11 C atoms, for example VeoVa9 R or VeoVa10 R (trademarks from Resolution). Particular preference is given to vinyl acetate.
Examples of suitable acrylic esters or methacrylic esters are esters of unbranched or branched alcohols having from 1 to 22 C atoms, in particular from 1 to 15 C atoms. Preferred methacrylic esters or acrylic esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, lauryl acrylate, myristyl acrylate, stearyl acrylate, palmityl acrylate, lauryl methacrylate, myristyl methacrylate, stearyl methacrylate, and palmityl methacrylate. Particular preference is given to methyl acrylate, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and 2-ethylhexyl acrylate.
Preferred vinyl aromatics are styrene, methylstyrene, and vinyltoluene. Preferred vinyl halide is vinyl chloride. The preferred olefins are ethylene and propylene, and the preferred dienes are 1,3-butadiene and isoprene.
It is also optionally possible to copolymerize from 0.1 to 10% by weight, based on the total weight of the monomer mixture, of ancillary monomers. It is preferable to use from 0.5 to 5% by weight of ancillary monomers. Examples of ancillary monomers are ethylenically unsaturated mono- and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid, and maleic acid; ethylenically unsaturated carboxamides and the corresponding nitriles, preferably acrylamide and acrylonitrile; mono- and diesters of fumaric acid and maleic acid, for example the diethyl and diisopropyl esters, and maleic anhydride, ethylenically unsaturated sulfonic acids and salts thereof, preferably vinylsulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid. Other examples are silicon-functional comonomers, for example acryloxypropyltri(alkoxy)-, and methacryloxypropyltri(alkoxy)silanes, vinyltrialkoxysilanes, and vinylmethyldialkoxysilanes, where alkoxy groups present can by way of example be ethoxy and ethoxy propylene glycol ether moieties. Mention may also be made of monomers having hydroxy or CO groups, for example hydroxyalkyl esters of methacrylic acid and of acrylic acid, examples being hydroxyethyl, hydroxypropyl, and hydroxybutyl acrylate and methacrylate, and compounds such as diacetone-acrylamide and acetylacetoxyethyl acrylate and methacrylate.
It is preferable that the ethylenically unsaturated monomers comprise only one ethylenically unsaturated group.
Preference is given to homo- or copolymers which comprise one or more monomers from the group comprising vinyl acetate, vinyl esters of α-branched monocarboxylic acids having from 9 to 11 C atoms, vinyl chloride, ethylene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, styrene.
More preference is given to copolymers using vinyl acetate and ethylene; using vinyl acetate, ethylene, and a vinyl ester of α-branched monocarboxylic acids having from 9 to 11 C atoms; copolymers using vinyl acetate and one or more (meth)acrylic esters of unbranched or branched alcohols having from 1 to 15 C atoms, in particular methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and optionally ethylene; copolymers using one or more vinyl esters, ethylene, and one or more vinyl halides; copolymers using one or more (meth)acrylic esters of unbranched or branched alcohols having from 1 to 15 C atoms, for example n-butyl acrylate and 2-ethylhexyl acrylate, and/or methyl methacrylate; copolymers using styrene and one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; copolymers using 1,3-butadiene and styrene, and/or methyl methacrylate, and optionally other acrylic esters; these mixtures mentioned can optionally also comprise one or more of the abovementioned ancillary monomers.
Particular preference is given to copolymers of one or more vinyl esters with from 1 to 50% by weight of ethylene; copolymers of vinyl acetate with from 1 to 50% by weight of ethylene and from 1 to 50% by weight of one or more other comonomers from the group of vinyl esters having from 1 to 12 C atoms in the carboxylic acid moiety, for example vinyl propionate, vinyl laurate, vinyl esters of alpha-branched carboxylic acids having from 9 to 13 C atoms, for example VeoVa9, VeoVa10, VeoVa11; copolymers of one or more vinyl esters, from 1 to 50% by weight of ethylene, and preferably from 1 to 60% by weight of (meth)acrylic esters of unbranched or branched alcohols having from 1 to 15 C atoms, in particular n-butyl acrylate or 2-ethylhexyl acrylate; and copolymers using from 30 to 75% by weight of vinyl acetate, from 1 to 30% by weight of vinyl laurate, or vinyl ester of an alpha-branched carboxylic acid having from 9 to 11 C atoms, and from 1 to 30% by weight of (meth)acrylic esters of unbranched or branched alcohols having from 1 to 15 C atoms, in particular n-butyl acrylate or 2-ethylhexyl acrylate, where these also comprise from 1 to 40% by weight of ethylene; copolymers using one or more vinyl esters, from 1 to 50% by weight of ethylene, and from 1 to 60% by weight of vinyl chloride; these polymers can also comprise the quantities mentioned of the ancillary monomers mentioned, and the data in % by weight here always give a total of 100% by weight.
Particular preference is also given to (meth)acrylic ester polymers such as copolymers of n-butyl acrylate or 2-ethylhexyl acrylate, or copolymers of methyl methacrylate using n-butyl acrylate and/or 2-ethylhexyl acrylate; styrene-acrylic ester copolymers using one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; vinyl acetate-acrylic ester copolymers using one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and optionally ethylene; styrene-1,3-butadiene copolymers; these polymers can also comprise the quantities mentioned of ancillary monomers, and the data in % by weight here always give a total of 100% by weight.
Most preference is given to copolymers using vinyl acetate and from 5 to 50% by weight of ethylene; and copolymers using vinyl acetate, from 1 to 50% by weight of ethylene, and from 1 to 50% by weight of a vinyl ester of α-branched monocarboxylic acids having from 9 to 11 C atoms; and copolymers using from 30 to 75% by weight of vinyl acetate, from 1 to 30% by weight of vinyl laurate, or vinyl ester of an alpha-branched carboxylic acid having from 9 to 11 C atoms, and from 1 to 30% by weight of (meth)acrylic esters of unbranched or branched alcohols having from 1 to 15 C atoms, where these also comprise from 1 to 40% by weight of ethylene; and copolymers using vinyl acetate, from 5 to 50% by weight of ethylene, and from 1 to 60% by weight of vinyl chloride.
The method here for the selection of the monomers and, respectively, the selection of the proportions by weight of the comonomers is such that the resultant glass transition temperature Tg is generally ≦120° C., preferably from −50° C. to +60° C., still more preferably from −30° C. to +40° C., and most preferably from −15° C. to +20° C. The glass transition temperature Tg of the polymers can be determined in a known manner by means of differential scanning calorimetry (DSC). Tg can also be approximated by means of the Fox equation. According to Fox T. G., Bull. Am. Physics Soc. 1, 3, page 123 (1956), the relationship is: 1/Tg=x1/Tg1+x2/Tg2+ . . . +xn/Tgn, where xn is the mass fraction (% by weight/100) of the monomer n, and Tgn is the glass transition temperature in Kelvin of the homopolymer of the monomer n. Tg values for homopolymers are listed in Polymer Handbook 2nd edition, J. Wiley & Sons, New York (1975).
The polymers are produced in a known manner by way of example by the emulsion polymerization process or by the suspension polymerization process in the presence of emulsifiers or preferably of protective colloids, preferably by the emulsion polymerization process, where the polymerization temperature is generally from 20° C. to 100° C., preferably from 60° C. to 90° C., and in the case of copolymerization of gaseous comonomers such as ethylene operations can preferably be carried out under pressure, generally at from 5 bar to 100 bar. The polymerization is initiated by the water-soluble or monomer-soluble initiators or redox-initiator combinations commonly used for emulsion polymerization or suspension polymerization. Regulating substances can be used to control molecular weight during the polymerization. Protective colloids can be used for stabilization, optionally in combination with emulsifiers. The polymers preferably take the form of aqueous protective-colloid-stabilized dispersions.
Examples of protective colloids commonly used to stabilize the polymerization mixture are partially hydrolyzed or fully hydrolyzed polyvinyl alcohols; polyvinylpyrrolidones; polyvinylacetals; poly-saccharides in water-soluble form, for example starches (amylose and amylopectin), celluloses and carboxymethyl, methyl, hydroxyethyl, and hydroxypropyl derivatives thereof; proteins such as casein or caseinate, soya protein, gelatins; lignosulfonates; synthetic polymers such as poly(meth)acrylic acid, copolymers of (meth)acrylates having carboxy-functional comonomer units, poly(meth)acrylamide, polyvinyl-sulfonic acids, and water-soluble copolymers thereof; melamine-formaldehydesulfonates, naphthalene-form-aldehydesulfonates, styrene-maleic acid copolymers and vinyl ether-maleic acid copolymers. Preference is given to partially hydrolyzed or fully hydrolyzed polyvinyl alcohols. Particular preference is given to partially hydrolyzed polyvinyl alcohols with a degree of hydrolysis of from 80 to 95 mol % and with a Höppler viscosity of from 1 to 30 mPas in 4% aqueous solution (Höppler method at 20° C., DIN 53015).
Examples of suitable emulsifiers are anionic, cationic, or nonionic emulsifiers, for example anionic surfactants, such as alkyl sulfates having a chain length of from 8 to 18 C atoms, alkyl or alkylaryl ether sulfates having from 8 to 18 C atoms in the hydrophobic moiety and up to 40 ethylene oxide or propylene oxide units, alkyl- or alkylarylsulfonates having from 8 to 18 C atoms, esters and hemiesters of sulfosuccinic acid with monohydric alcohols or alkylphenols, and nonionic surfactants such as alkyl polyglycol ethers or alkylaryl polyglycol ethers having from 8 to 40 ethylene oxide units. The quantity of emulsifiers generally used is from 1 to 5% by weight, based on the total weight of the monomers. It is preferable to carry out polymerization without addition of emulsifiers.
The solids content of the resultant aqueous dispersions is preferably from 30 to 75% by weight, particularly preferably from 50 to 60% by weight.
In order to convert the polymers into water-redispersible polymer powders, the dispersions can, optionally after addition of other protective colloids as drying aid, be dried, for example by means of fluidized-bed drying, freeze drying or spray drying. It is preferable that the dispersions are spray dried. The spray drying here can take place in conventional spray drying systems, where the atomization can be achieved by means of single-, double-, or multiple-fluid nozzles, or by using a rotating disk. The selected discharge temperature is generally in the range from 45° C. to 120° C., preferably from 60° C. to 90° C., depending on system, resin Tg, and desired degree of drying. The viscosity of the feed to the nozzles is adjusted by way of the solids content in such a way so as to give a value <500 mPas (Brookfield viscosity at 20 revolutions and 23° C.), preferably <250 mPas. The solids content of the dispersion to be supplied to the nozzles is >35%, preferably >40%.
The total quantity generally used of the drying aid is from 0.5 to 30% by weight, based on the polymeric constituents of the dispersion. This means that the total quantity of protective colloid before the drying procedure is preferably to be at least from 1 to 30% by weight, based on polymer content; it is particularly preferable to use a total of from 5 to 20% by weight of protective colloid, based on the polymeric constituents of the dispersion. Examples of suitable drying aids are the abovementioned protective colloids.
A content of up to 1.5% by weight of antifoam, based on the main polymer in the material supplied to the nozzles, has often proven to be advantageous. The resultant powder can be modified with an antiblocking agent (anticaking agent) in order to increase capability for storage by improving resistance to blocking, in particular in the case of powders with low glass transition temperature, a preferred quantity being from 1 to 30% by weight, based on the total weight of polymeric constituents. Examples of antiblocking agents are Ca carbonate, Mg carbonate, talc, gypsum, silica, kaolins such as metakaolin, and silicates with particle sizes preferably in the range from 10 nm to 10 μm.
It is preferable to use the polymers in the form of protective-colloid-stabilized aqueous dispersions, or particularly preferably in the form of protective-colloid-stabilized water-redispersible polymer powders.
The latent heat accumulators are present in microcapsules, having been incorporated or included or embedded therein. Microcapsules are generally core-shell structures. The expression core-shell structure is known to the person skilled in the art and denotes structures in which a substance or a composition (core) is encapsulated by another substance or composition (shell). The production of corresponding latent-heat-accumulating microcapsules is known by way of example from WO99/24525.
The core usually comprises the latent-heat-accumulating materials. The core preferably comprises at least 50% by weight, particularly at least 70% by weight, and most preferably at least 80% by weight, of latent-heat-accumulating materials, based on the total weight of the core of a microcapsule. The latent-heat-accumulating materials preferably have a solid/liquid phase transition in the temperature range from −20 to 120° C., particularly from 0 to 60° C., and most preferably from 0 to 30° C.
Examples of latent-heat-accumulating materials are aliphatic hydrocarbon compounds, such as saturated or unsaturated C 10 to C 40 -hydrocarbons, which are branched or preferably linear, for example n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, n-eicosane, n-heneicosane, n-docosane, n-tricosane, n-tetracosane, n-pentacosane, n-hexacosane, n-heptacosane, n-octacosane and cyclic hydrocarbons, for example cyclohexane, cyclooctane, cyclodecane; aromatic hydrocarbon compounds such as benzene, naphthalene, biphenyl, o- and m-terphenyl, C 1 to C 40 -alkyl-substituted aromatic hydrocarbons, such as dodecylbenzene, tetradecylbenzene, hexadecylbenzene, hexylnaphthalene, and decylnaphthalene; saturated or unsaturated C 6 to C 30 -fatty acids, such as lauric, stearic, myristic, palmitic, oleic, or behenic acid; fatty alcohols, such as lauryl, stearyl, oleyl, myristyl, and cetyl alcohol, or coconut fatty alcohol; C 6 to C 30 -fatty amines, such as decylamine, dodecylamine, tetradecylamine, or hexadecylamine; esters such as C 1 to C 10 -alkyl esters of fatty acids, for example propyl palmitate, methyl stearate, and methyl palmitate, and methyl cinnamate; natural and synthetic waxes such as montanic acid waxes, montanic ester waxes, carnauba wax, polyethylene wax, oxidized waxes, polyvinyl ether wax, ethylene-vinyl acetate wax, and hard waxes from Fischer-Tropsch processes; halogenated hydrocarbons, such as chloroparaffin, bromooctadecane, bromopentadecane, bromononadecane, bromoeicosane, and bromodocosane.
The shell of the microcapsules is usually composed of polymers. The shell polymers are generally based on one or more of the abovementioned ethylenically unsaturated monomers, and usually on one or more polyfunctional monomers.
Examples of polyfunctional monomers are esters or ethers of diols or of polyols with acrylic acid or methacrylic acid, and also the diallyl and divinyl ethers of these diols. Preference is given to trimethylolpropane triacrylate and trimethylolpropane trimethacrylate, triallyl ether of pentaerythritol, pentaerythrityl tetraacrylate, ethanediol diacrylate, divinylbenzene, ethylene glycol dimethacrylate, butylene 1,3-glycol dimethacrylate, methallylmethacrylamide, allyl methacrylate, and in particular propanediol diacrylate, butanediol diacrylate, pentanediol diacrylate, and hexanediol diacrylate, and the corresponding methacrylates.
The proportion of the polyfunctional monomers is usually up to 80% by weight, preferably from 5 to 60% by weight, and particularly preferably from 10 to 50% by weight, based on the total weight of the monomers that form the shell of the microcapsules.
The particle sizes of the microcapsules are preferably from 1 to 35 μm, and particularly preferably from 3 to 10 μm (determined by means of statistical light scattering by using TGV-Coulter LS 13320 equipment).
The ratio by weight of the polymers based on one or more ethylenically unsaturated monomers to the microcapsules comprising one or more latent heat accumulators in the mixtures for the thermoplastic forming techniques is preferably from 4:1 to 1:4, particularly preferably from 3:1 to 1:3, still more preferably from 2:1 to 1:2, and most preferably 1:1.
The mixtures for the thermoplastic forming techniques are based on preferably from 10 to 90% by weight, particularly preferably from 30 to 70% by weight, and most preferably from 40 to 60% by weight, of polymers based on one or more ethylenically unsaturated monomers; and/or preferably from 10 to 90% by weight, particularly preferably from 30 to 70% by weight, and most preferably from 40 to 60% by weight, of microcapsules which comprise one or more latent heat accumulators, based in each case on the dry weight of the mixtures.
The quantities of alternative polymers, such as polyurethanes, present in the mixtures are preferably less than 20% by weight, particularly preferably less than 10% by weight, and even more preferably less than 5% by weight, based in each case on the dry weight of the mixtures. It is most preferable that the mixtures comprise no polyurethane.
Other materials that can optionally be used in the production of the moldings or sheet material comprising latent heat accumulators are additional substances such as lubricants, for example calcium stearate or zinc stearate, commonly used flame retardants, plasticizers, antioxidants, UV stabilizers, antistatic agents, adhesion promoters, antiblocking agents, dyes, pigments, fillers, processing aids, and peroxides such as peroxodicarbonate for postcrosslinking. Preference is given here to lubricants and flame retardants. By way of example, from 3 to 10% by weight of flame retardants can be present, based on the dry weight of the mixtures.
The mixtures can moreover comprise one or more fillers, such as organic fillers, based by way of example on wood, leather, cork, or coconut material, or inorganic fillers, such as gypsum, lime, chalk, talc, silicas, kaolins, silicates, or titanium dioxide. It is preferable that the quantities of fillers present in the mixtures for the thermoplastic forming techniques are less than 30% by weight, particularly less than 15% by weight, and more preferably less than 5% by weight, based in each case on the dry weight of the respective mixture. It is most preferable that the mixtures comprise no fillers.
The individual constituents of the mixtures are mixed, and are then processed by means of the conventional thermoplastic forming techniques to give moldings or sheet materials comprising latent heat accumulators. Preference is given to dry mixtures here. However, it is also possible by way of example to use mixtures in aqueous form.
The mixing can by way of example be achieved in a heatable/coolable mixer, or else by way of direct granulation, for example in an extruder, Palltruder, or agglomerator. It is preferable that the mixing is achieved in a multiscrew extruder, planetary-gear extruder, and particularly in a twin-screw extruder, in particular in a contrarotating twin-screw extruder.
Examples of suitable thermoplastic forming techniques are extrusion, injection molding, pressing, granulation, and calendering. Preference is given to extrusion, and in particular to pressing.
It is preferable to begin by using thermoplastic forming techniques to produce granulates, pellets or pulverulent compound materials, which are then further processed by using further thermoplastic forming techniques. The particle sizes of the granulates or pellets are preferably from 2 to 10 mm.
The processing temperature during the mixing process is generally from 0° C. to 120° C., preferably from 20° C. to 100° C., and particularly preferably from 40° C. to 100° C. The processing temperature during the thermoplastic processing is generally from 80° C. to 250° C., preferably from 100° C. to 180° C. The temperature ranges mentioned are particularly advantageous for providing intimate mixing of the polymers, in particular the polymers in the form of water-redispersible polymer powders, and of the other components, and for developing the binder effect of the polymers. Higher temperatures can lead to formation of degraded products.
The procedure of the invention is suitable for the production of a very wide variety of moldings or sheet materials, for example sheets, foils, webs, or any other roll product. The moldings or sheet materials can be processed with other materials to give composite materials, for example via adhesive bonding onto timber boards with woodworking glue. Corresponding products are used by way of example in the construction industry, in particular in the construction of parts of buildings or of constituents of buildings, for example ceilings, walls, or floors. Other application sectors are the shoe industry, apparel industry, sports industry, leisure industry, and in particular the furniture industry.
Surprisingly, the proportions of the microcapsules that are damaged during the procedure of the invention, despite the thermoplastic processing, are preferably less than 3% by weight, particularly preferably less than 2% by weight, and most preferably less than 1% by weight; the meaning of “damaged” here is that the heat-accumulating material can escape from the microcapsules as a consequence of the thermoplastic processing.
In particular the copolymers comprising ethylene units are particularly advantageous for the processability of the mixtures of the invention. The polymer glass transition temperatures Tg of the invention are also useful for the processability of the mixtures. Copolymers comprising units of vinyl acetate and ethylene are particularly advantageous for the further processing of the moldings or sheet materials, for example by means of adhesive bonding, for example with woodworking glue.
The moldings or sheet materials produced in the invention feature high mechanical strength values, even when proportions of microcapsules or other constituents are very high. It is possible to introduce surprisingly large quantities of latent-heat-accumulating microcapsules into the moldings or sheet materials, i.e. to achieve high fill levels. The shape, and in particular the layer thickness, of the products of the invention can also be varied within a relatively wide range. Sheet materials with homogeneous surface are moreover obtainable. It is pleasing to note that no, or very little, foaming occurs during the conduct of the process of the invention, in contrast to the casting-resin process, for example using polyurethane casting resins. The moldings or sheet materials produced are markedly more compact and have fewer air inclusions. It is possible to achieve “continuous” production of sheet materials in different thicknesses. Surfaces produced are smooth and pore-free, and can be passed directly on for further processing.
The examples below serve for further explanation of the invention:
The following materials were used:
Vinnex A, B, and C:
Polyvinyl-alcohol-stabilized copolymers in the form of water-redispersible polymer powders with the following glass transition temperatures Tg:
Vinnex A: Tg 16° C.; Vinnex B: Tg −14° C.; Vinnex C: Tg −7° C.
Micronal DS 5040 X:
Microcapsules which comprise paraffin (phase transition temperature 23° C.) as heat-accumulating material and having a shell composed of a high crosslinked polymethyl methacrylate.
Process: Production of the sheet materials by means of pressing (examples 2 to 4):
The materials mentioned in the table were mixed in the quantitative proportions mentioned in the table for 5 min at 130° C. on a roll mill. The resultant milled sheet was then processed in a static press at a temperature of 150° C. and at a pressure of 5 N/mm 2 with a press time of 5 min to give pressed sheets of thickness 2 mm.
Process: Production of the sheet materials by means of extrusion (example 1):
The materials mentioned in the table were mixed in the quantitative proportions mentioned in the table for 5 min in a cooling mixer. The mixture was then processed in a Weber DS85 twin-screw extruder with EMO sheet die to give sheet materials of thickness 8 mm.
TABLE
Ex. 1
Ex. 2
Ex. 3
Ex. 4
Process
Extrusion
Pressing
Pressing
Pressing
Micronal DS 5040 X
50
50
50
50
[pts. by wt.]
Vinnex A [pts. by wt.]
50
50
Vinnex B [pts. by wt.]
50
Vinnex C [pts. by wt.]
50
Shore A
90.3
65.6
77.4
91.7
Shore D
31.6
10.6
16.4
30.1
Tensile stress [MPa]
4.31
1.74
2.33
5.58
Tensile strain [%]
87.86
331.9
261.6
126.9
Tensile modulus of elasticity
378.02
DSC measurement [Jg{circumflex over ( )}−1]
47.99
44.09
43.46
46.02
Testing:
Shore A hardness, and also Shore D hardness, was determined on the pressed sheets in accordance with DIN 53505.
The mechanical strength of the pressed sheets was determined in the tensile test by determining tensile stress and tensile strain at break, and tensile modulus of elasticity was determined in accordance with DIN EN ISO 527 1-3 and, respectively, DIN 53504.
DSC Measurement:
The heat-accumulation capacity of the sheet materials was determined by using DSC Mettler Toledo DSC1.306 equipment with the following temperature program: the respective sheet material was heated in each case at a rate of 1 K/min from 0.0° C. to 35° C., then cooled to −30° C., and finally again heated to 35° C.
The table lists the test results.
The theoretically achievable result for the heat-accumulation capacity of the sheet materials is 50 J/g. Examples 1 to 4 come very close to that value. From this it is clear that only a very small number of the microcapsules has been damaged during thermoplastic processing.
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The invention provides methods for producing sheetlike structures or shaped articles that comprise latent heat storage media, characterized in that mixtures comprising one or more microcapsules which contain one or more latent heat storage media, and one or more polymers based on one or more ethylenically unsaturated monomers selected from the group consisting of vinyl esters, (meth)acrylic esters, vinylaromatics, olefins, 1,3-dienes and vinyl halides, are processed by means of thermoplastic shaping techniques.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of German patent application 10054697.8 filed Nov. 4, 2000, herein incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to an open-end spinning device and, more particularly, to an opening cylinder for an open-end spinning device wherein a ring of opening teeth is detachably fixed about the body of the opening cylinder.
Such opening cylinders for open-end spinning devices are known in various embodiments and are described, e.g., in German Patent Publication DE 197 12 880 A1.
Moreover, German Patent Publication DE 40 36 017 A1 teaches an opening cylinder whose toothed opening ring is arranged directly on an outwardly disposed rotor of an electric drive. More specifically, the toothed opening ring is fixed on the rotatably mounted outside rotor of an opening-cylinder drive by means of a tension unit.
Such a tension unit has been thoroughly proven in the machine-building industry, and in particular makes possible a reliable fixation of a toothed opening ring on a rotatably mounted structural component that can not be secured against rotation during the mounting of the toothed opening ring, while the tension unit also permits the opening ring to be detached, if necessary. However, such a tension unit is a relatively complicated and expensive construction element.
Moreover, the replacement of a toothed opening ring is relatively difficult and time-consuming when using such a tension unit because the individual tightening screws of the tension unit must first be loosened by an appropriate tool and then subsequently re-tightened after the mounting of a new toothed opening ring.
SUMMARY OF THE INVENTION
In view of the above described state of the art, the present invention seeks to address the problem of providing an opening cylinder for an open-end spinning device in which the toothed opening ring can be readily and smoothly fixed on a freely rotatable structural component of the opening cylinder.
The invention addresses this problem by providing an opening cylinder for an open-end spinning device which basically comprises an opening cylinder drive having a driven structural component supported for free rotation, an opening ring, and a torque-free rapid tension device for detachably securing the opening ring in a readily replaceable manner about the structural component.
The torque-free rapid tension device of the present invention has the particular advantage that it also makes possible a smooth replacement of a toothed opening ring if the structural component receiving the toothed opening ring is mounted in a freely rotatable manner and, particularly, cannot be fixed against rotation. In addition, the torque-free rapid tension device of the invention represents a very economical and reliable fastening means that does not require the use of any tool.
Such a torque-free rapid tension device can be embodied with particular advantage, for example, in an open-end spinning device utilizing a so-called outside rotor as the opening cylinder drive, particularly when the toothed opening ring is to be fixed directly on the outside rotor of the drive whose freely rotatable mounting cannot be fixed against rotation for purposes of the installation of the ring.
In a preferred embodiment, the torque-free rapid tension device comprises two eccentric clamps that load a spring element, preferably a plate spring. The plate spring is supported on a flanged wheel of the opening cylinder and acts to apply an axial force to the flanged wheel. This axial force assures that the toothed opening ring is reliably fixed between the flanged wheel and an annular shoulder on the outside rotor of the opening cylinder drive.
Each of the eccentric clamps preferably comprises a manually operable actuation flap as well as at least one eccentrically mounted clamping body. Eccentric clamps designed in this manner can be operated without the use of a special tool, as already indicated previously, and exert such a sufficient pressure on the plate spring on account of their translation in their work position that the plate spring is deformed.
The eccentric clamps are connected via a pivot shaft to a bolt that, in turn, can be fixed via a catch device, such as a bayonet catch or a slide catch, to the outside rotor of the electric drive. Such a catch device constitutes a fastening means that is simple yet reliable during operation and can be loosened without problems at any time in case of need, especially in embodiments utilizing mating projections and grooves. The actuation flaps arranged on the eccentric clamps are protected in the operating state of the opening cylinder in a central recess of the flanged wheel. Such a design of the eccentric clamps assures not only an optimal protection of operating personnel, especially if the central recess is closed with a cover flap (not shown in the exemplary embodiment described hereinafter), but the actuation flaps of the eccentric clamps can also be accessed without problems when needed. Specifically, in order to disengage and detach the torque-free rapid tension device, the actuation flap merely need be folded upwardly and then the bolt of the torque-free rapid tension device fixed by the catch device is rotated, e.g., by about 45 degrees counterclockwise.
Further details of the invention will be understood from the following description of an exemplary embodiment with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial cross-sectional view of an opening cylinder for an open-end spinning machine wherein the toothed opening ring is arranged on the outside rotor of an electric drive and is fixed by a torque-free rapid tension device in accordance with the present invention.
FIG. 2 is an end elevational view of the flanged wheel of the opening cylinder from the perspective of arrow X in FIG. 1 .
FIG. 3 is a cross-sectional view taken through the torque-free rapid tension device of the present invention along section line III—III in FIG. 2 .
FIG. 4 is a side view of the torque-free rapid tension device of the present invention in a loosened state.
FIG. 5 is a cross-sectional view through the torque-free rapid tension device taken along section line V—V in FIG. 4 illustrating the bayonet catch device thereof.
FIG. 6 is another cross-sectional view of the torque-free rapid tension device of the present invention similar to FIG. 5 but illustrating an alternative embodiment of the bayonet catch device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, an opening cylinder 1 is mounted on an electric drive 4 in the form of a so-called outside rotor drive wherein a stator 9 is fixedly connected via appropriate fastening means, e.g., screw bolts 10 , to an opening cylinder housing 11 and is radially outwardly surrounded by a rotor 3 commonly referred to as an outside rotor.
The winding 12 of the stator 9 of opening cylinder drive 4 is connected via an energy lead 13 to an energy source (not shown). Moreover, a toothed opening ring 2 of opening cylinder 1 is replaceably fixed on the outer circumference 27 of the rotor 3 of electric drive 4 . More specifically, the toothed opening ring 2 is fixed between a flanged wheel 5 and an annular shoulder 6 of the outside rotor 3 and is loaded by flanged wheel 5 in the axial direction. The flanged wheel 5 is connected to outside rotor 3 via a torque-free rapid tension device 7 that acts on a plate spring 8 .
The flanged wheel 5 and opening ring 2 can also be designed as a mounting unit wherein a centering shoulder 28 of flanged wheel 5 and the inside diameter 29 of the toothed opening ring 2 are coordinated with one another to form a snug fit that assures that these components can be assembled and disassembled as a common unit. The fittings ring 2 and the flanged wheel 5 can be preliminarily connected to each other in an earlier work step.
As is apparent in particular from FIGS. 2 to 4 , torque-free rapid tension device 7 is comprised, e.g., of a bolt 14 having radial shoulders 15 for a bayonet catch 16 as well as a pivot shaft 17 . Two actuating flaps 18 are pivotably mounted on bolt 14 .
Actuating flaps 18 are connected to the bolt 14 via eccentrically mounted bores in clamping hubs 19 as well as via the pivot shaft 17 .
The bolt 14 is supported by its cylindrical body 20 in a corresponding bore 21 of a collar-like shoulder 22 of the outside rotor 3 such that the bolt 14 can rotate to a limited degree. More specifically, as is depicted in one embodiment in FIG. 5, axial grooves 23 as well as helical grooves 24 are formed into the collar-like shoulder in which grooves the radial shoulders 15 of bolt 14 are guided, or as alternatively depicted in another embodiment if FIG. 6, the bolt 14 may itself be formed with radial and helical grooves 23 ′ and 24 ′ into which corresponding radial shoulders 15 ′ of collar-like shoulder 22 engage. Thus, grooves 23 , 24 or 23 ′, 24 ′ form, together with radial shoulders 15 or 15 ′, a bayonet catch 16 that is a component of torque-free rapid tension device 7 .
The operation of the present invention may thus be understood. In the operating state of the opening cylinder, as is indicated, e.g., in FIGS. 1, 2 and 3 , actuation flaps 18 are pivoted outwardly and rest within central receiving bore 25 of flanged wheel 5 wherein the flaps are protected. This central receiving bore 25 can be additionally closed by a protective cap (not shown). In this position, the eccentrically supported clamping hubs 19 of eccentric clamps 26 load plate spring 8 , that in turn resultantly acts with a component of axial force on the flanged wheel 5 . Under the action of this axial force component, the toothed opening ring 2 is pressed against the annular shoulder 6 on the outside rotor 3 of the electric drive 4 and is thereby fixed in a non-positive manner.
In order to replace the toothed opening ring 2 , the electric drive 4 is initially stopped by switching the energy source to the stator 12 to deactuate the delivery of operating current to the stator 12 .
As soon as the opening cylinder 1 has thereafter slowed to a standstill, the actuating flaps 18 of the eccentric clamps 26 of the torque-free rapid tension device 7 are pivoted into the position indicated in FIG. 4 in which eccentrically supported clamping hubs 19 of eccentric clamps 26 are out of contact with plate spring 8 . The eccentric clamps 26 are subsequently rotated, e.g., counterclockwise, via actuating flaps 18 until the radial shoulders 15 on the bolt 14 of the torque-free rapid tension device 7 correspond with the axial grooves 23 in the collar-like shoulder 22 of the outside rotor 3 . The torque-free rapid tension device 7 can then be withdrawn from the bore 21 of the collar-like shoulder 22 of the outside rotor 3 and the flanged wheel 5 as well as the toothed opening ring 2 can be demounted. No tools are necessary to carry out the steps described above.
The mounting of a new toothed opening ring 2 takes place in the reverse order of these described steps. That is, after a new opening ring 2 has been placed about the outer circumference 27 of the outside rotor 3 of the electric drive 4 , the flanged wheel 5 is positioned and the plate spring 8 is placed into central recess 25 of the flanged wheel 5 . The torque-free rapid tension device 7 is then mounted. Specifically, the cylindrical body 20 of the bolt 14 is introduced into the bore 21 of the collar-like shoulder 22 of outside rotor 3 with its radial shoulders 15 aligned with the axial grooves 23 to slide axially thereinto. The bolt 14 is then rotated clockwise by the actuating flaps 13 , which fixes the torque-free rapid tension device 7 on the outside rotor 3 of the electric drive 4 . The actuating flaps 18 are then pivoted outwardly about the pivot shaft 17 . The eccentrically supported clamping hubs 19 of the eccentric clamps 26 load the plate spring 8 during this pivoting movement, whereby the spring presses the flanged wheel 5 against the opening ring 2 and secures it in a non-positive manner.
The torque-free rapid tension device 7 as thusly described makes possible not only a smooth and rapid replacement of the opening ring 2 but also represents a very inexpensive and reliable fastening device.
The invention is not intended to be limited to the exemplary embodiment described and illustrated in the drawings. Modifications of individual structural components are clearly possible without departing from the general concept of the invention.
It is possible, for example, that each eccentric clamps 26 does not comprise two clamping hubs 19 , as presented in the exemplary embodiment, but rather that only one clamping hub 19 is provided for each eccentric clamp 26 for loading the plate spring 8 .
Moreover, it is also conceivable, for example, that instead of using plate spring 8 a comparable spring element, e.g., a helical spring or the like is used.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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An opening cylinder ( 1 ) for an open-end spinning device with a detachably fixed opening ring ( 2 ) which can be fixed by a torque-free rapid tension device ( 7 ) in a readily replaceable manner on a rotatably supported structural component of an opening cylinder ( 1 ) driven by an opening cylinder drive ( 4 ).
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention pertains to a braking system for air conveyors. In particular, the present invention provides a braking system along the guide rails of an air conveyor that transports plastic bottles along a pathway between the guide rails. The braking system is selectively actuated to move into the pathway defined by the guide rails decreasing its width and positioning a stop of the braking system in the pathway where it will engage with bottles conveyed along the pathway by the air conveyor slowing and eventually stopping the bottles.
(2) Description of the Related Art
Air conveyors are typically employed in the rapid transport of empty plastic bottles of the type having an annular rim or a neck ring at the base of the bottle neck. A typical air conveyor includes a pair of flanges that are spaced from each other defining an elongated slot between the flanges. The spacing between the flanges is sufficiently large to enable a portion of the bottle just below the neck ring to pass through the spacing with the bottle suspended from the top surfaces of the flanges by the neck ring engaging on the top surfaces. A series of air ducts are positioned along the flanges above and/or below the elongated slot. A plenum of the air conveyor supplies a flow of air to the air ducts. The air ducts are oriented so that air ejected from the ducts will contact the plastic bottles pushing the bottles along the pathway defined by the elongated slot with the neck rings of the bottles sliding along the top surfaces of the spaced flanges.
Preferably, air conveyors transport bottles in closely spaced succession and at a substantial speed. A typical air conveyor is constructed with both straight sections and curved sections in order to transport the succession of bottles from one area to another. Air conveyors often have guide rails positioned below the slot defined by the pair of flanges. Pairs of guide rails positioned on opposite sides of the slot follow the conveyor path defined by the slot. The guide rails are usually spaced further apart from each other than are the flanges to allow the width of a bottle suspended from the flanges to pass easily between the guide rails. The guide rails limit the side-to-side movement of the succession of bottles conveyed by the air conveyor and thereby limit the extent to which the body of the bottle can swing outwardly or transversely from the air conveyor path, for example when the air conveyor rounds a curve, and thereby avoids a bottle neck or neck ring potentially becoming jammed in the air conveyor slot and stopping the succession of conveyed bottles.
With a typical air conveyor being capable of transporting a large succession of plastic bottles at a considerable speed, problems can be encountered when a large succession of bottles are stopped and accumulated at the end of the air conveyor. In prior art air conveyors, the leading bottle in a succession would be stopped at the end of the air conveyor by a selectively operated gate mechanism. This first bottle stopped by the gate mechanism would in turn stop all subsequent bottles that trailed it in the line of succession of bottles conveyed by the air conveyor. Thus, this first stop bottle would have a force exerted on it by each of the trailing bottles conveyed by the conveyor mechanism. With a long line of succession of bottles, the force exerted on the first stopped bottle could be sufficient to damage the bottle. In a like manner, the second 20 bottle in the sequence has a force exerted on it by each of its trailing bottles. This force could also be sufficiently large in a long succession of bottles to cause damage. In this manner, several bottles at the forward end of a long succession of bottles stopped by the conveyor system could be damaged. In addition, when the air conveyor is conveying a large number of bottles in a group and they come to one or more bottles stopped by the gate of the air conveyor, the impact of the large group of conveyed bottles with the stopped bottle or bottles can cause the forward most stop bottle to be forced through the gate.
To overcome this problem, a mechanism is needed that not only engages with the forward most bottle in a succession of bottles to stop the succession of bottles, but engages with and brakes several of the bottles in the succession of bottles. In addition, it is desirable that the mechanism have a simplified construction that would enable it to be retrofit to an existing air conveyor at several spots along the length of the air conveyor to enable stopping groups of bottles conveyed by the air conveyor at controlled points along the air conveyor length to thereby control the number of bottles that would accumulate at any one position along the length of the air conveyor where the succession of conveyed bottles are stopped.
SUMMARY OF THE INVENTION
The conveyor braking system of the invention can be employed with virtually any type of conveyor system that conveys a succession of articles along a flow path, where the succession of articles can be engaged by the braking system from opposite sides of the flow path. In the operative environment of the braking system to be described, the system is employed on an air conveyor that transports plastic bottles. The bottles are of a conventional type with each bottle having a neck at its upper end and an annular shoulder below the neck that defines the upper portion of the body of the bottle. An outwardly projecting annular rim or neck ring is positioned below the neck of the bottle and above the bottle shoulder.
The air conveyor with which the braking system of the invention is described employs a pair of spaced flanges through which the neck and neck ring of the bottle project. The neck ring rests on top surfaces of the spaced flanges suspending the shoulder and body of the bottle below the flanges. The air conveyor includes a series of air ducts that direct a supply of air against the bottle causing the bottle to move along the length of the air conveyor with the neck ring of the bottle sliding along the top surfaces of the flanges. Typical air conveyors of this type are described in the U.S. Patents of Ouellette U.S. Pat. No. 5,437,521, issued Aug. 1, 1995, and U.S. Pat. No. 5,611,647 issued Mar. 18, 1997, both which are assigned the assignee of the present invention and incorporated herein by reference.
Air conveyors typically include a framework that supports the conveyor. They also often include guide rails that are support from the framework or suspended from the air conveyor in positions just below the air conveyor slot. The guide rails are provided in pairs that extend along the length of the conveyor with a spacing between the pair of guide rails that is centered below the spacing between the air conveyor slot. The spacing between the guide rails is usually slightly larger than the body of the bottles to be conveyed by the air conveyor. The guide rails limit the extent to which bottles conveyed by the air conveyor can rock side-to-side or transversely to their direction or path of conveyance.
The braking system of the invention is designed to enable its simple addition to an existing air conveyor system. The braking system is designed to be mounted adjacent the guide rails of the air conveyor. The system includes at least one stop that is mounted adjacent to one of the guide rails of the pair of guide rails of the air conveyor system. The stop includes an actuator that is selectively actuated to move the stop transversely toward and away from the spacing between the air conveyor guide rails. Thus, when the stop is actuated it moves into the pathway defined by the pair of guide rails of the air conveyor, reducing the transverse spacing or width of this pathway. Depending on the extent to which the stop moves into the pathway, the stop can come into engagement with the body of a bottle being conveyed along the pathway gripping the bottle between the stop and the guide rail on the opposite side of the pathway, or the stop can reduce the width of the pathway to the extent where the body of a bottle conveyed through the pathway will contact both the stop and the guide rail on the opposite side of the pathway with the engagement on the opposite sides of the bottle gradually braking the bottle and slowing its speed of conveyance as it passes along the stop.
The stop is constructed of first and second elongated bar sections that are connected end to end by a pivot joint. A first end, or upstream end of the first elongated bar section is mounted adjacent one of the pair of air conveyor guide rails by a pivot pin. The pivot pin extends through an oblong hole in the first end of the first bar section. The oblong hole extends in a direction along a center axis of the first bar section.
The second bar section has a pair of oblong holes therethrough adjacent its opposite ends. However, the oblong holes or slots of the second bar section extend in directions that are oriented at an angle to the center axis of the second bar section. Posts pass through each of the angled oblong slots of the second bar section mounting that section adjacent the one guide rail of the air conveyor and positioned downstream of the conveyor path from the first bar section.
An actuator is mounted between the second bar section of the stop and a stationary support of the air conveyor guide rail. The actuator of the preferred embodiment is a pneumatic actuator that is selectively supplied with pressurized air at its opposite ends to selectively extend and retract the length of the actuator. When the actuator is retracted, reducing its length, it pulls both the first and second bar sections of the stop toward the adjacent guide rail. The first and second bar sections of the stop extend along the length of the adjacent guide rail and do not project into the conveyor path between the pair of guide rails. Actuation of the actuator, causing its length to be extended, moves the second bar section in a translatory movement out into the spacing between the pair of guide rails. This movement of the second bar section also causes the first bar section to move in a pivoting movement about the pivot pin at its upstream end out into the spacing between the pair of guide rails. This movement of the two bar sections reduces the spacing between the opposite guide rail and the two bar sections of the stop, which also reduces the width of the conveyor pathway through which the bodies of the bottles are conveyed by the air conveyor. As bottles are conveyed along the conveyor pathway and begin to pass between the length of the first bar section of the stop and the opposite guide rail, the spacing between the first bar section and the opposite guide rail begins to decrease as the bottles continue in a downstream direction. The decreasing width or spacing between the stop and the opposite guide rail continues until the bottles reach the second bar section where the spacing between the second bar section of the stop and the opposite guide rail is the smallest. As the bottles continue to be conveyed downstream between the second bar section and the opposite guide rail, the engagement of the bodies of the bottles between the second bar section and opposite guide rail gradually slows the speed of conveyance of the bottles and, depending on the spacing between the second bar section and the opposite guide rail and the width of the bodies of the bottles, can gradually be brought to a complete stop by the braking system of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and features of the present invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures, wherein:
FIG. 1 is an end elevation view of a four lane air conveyor system where the braking system of the invention is installed on two of the four lanes;
FIG. 2 is a partial side elevation view of the braking system of the invention installed above a guide rails of an air conveyor, although it could also be mounted below the guide rail;
FIG. 3 is a partial fragmented, side elevation view of the braking system of FIG. 2;
FIG. 4 is a partial, fragmented, plan view of the braking system in its retracted position relative to the guide rails; and
FIG. 5 is a partial, fragmented, plan view of the braking system extended relative to the guide rails.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show a multi-channel air conveyor that serves as the operative environment of the present invention. Although a multi-channel air conveyor is shown, it should be understood that the present invention may be employed with a single channel air conveyor. FIG. 1 shows an end elevation view of the air conveyor 10 . The conveyor includes four conveyor channels 12 , each having a generally inverted U-shaped configuration with a top wall 14 and laterally spaced side walls 16 . Together, the channel top wall 14 and the side walls 16 give each of the channels 12 their generally, inverted Ushaped configuration surrounding an interior volume of each conveyor channel. The side walls 16 of each conveyor channel have lower sections 18 connected to the upper side walls 16 by threaded fasteners 22 . The lower sections 18 of the side walls have pluralities of air duct outlets (not shown) that extend through the conveyor channel side walls 16 and side wall lower sections 18 . The configurations of the air duct outlets direct jets of air ejected from the outlets to strike bottle containers 24 conveyed by the air conveyors in the area of the shoulder of the bottles, thereby forcing the bottles to travel downstream along the length of the air conveyor. In viewing FIG. 2, the downstream direction is from left to right.
Each of the air duct outlets in the side wall lower sections 18 is fed with pressurized air directed through air conduits that pass through the upper side walls 16 of the conveyor channels. These air conduits extend from the top surface of the conveyor channel top walls 14 completely through the side walls 16 to the air ducts of the side wall lower sections 18 . This construction of the air ducts and air conduits is employed in air conveyors of the type disclosed in the U.S. Patent of Ouellette, U.S. Pat. No. 5,628,588, issued May 13, 1997 and incorporated herein by reference.
Referring to FIG. 1, the interior volume of each of the channels 12 is comprised of an upper portion and a lower portion separated by pairs of laterally spaced, longitudinally extending flanges 32 . Opposed pairs of flanges 32 extend from the opposed side walls 16 of each of the channels 12 into the interior volume of the channels and define slots 34 between each pair of flanges. The flanges 32 are held between the upper portions of the channel side walls 16 and the lower sections 18 of the channel side walls. Set screws (not shown) are employed to secure the flanges 32 in their positions on the side walls 16 . By loosening the set screws, opposed pairs of flanges 32 can be adjustably positioned laterally toward or away from each other to adjust the lateral widths of the slots 34 . In a bottle conveyor of the type shown in FIGS. 1 and 2, the lateral widths of the slots 34 is adjusted to be sufficiently large to receive the neck of the bottle container 24 therein with the annular rim or neck ring 36 of the bottle container supported on the top surfaces of the flanges 34 and with the tapered shoulder and body of the bottle suspended below the pair of flanges.
An air plenum 38 extends longitudinally along the top wall 14 of the conveyor channels 12 . The plenum 38 is an elongated hollow box comprised of a pair of side walls 42 and a top wall 44 that surround an interior volume of the plenum. As shown in FIG. 1, the plenum includes a connecting plate 46 that attaches adjacent bottom walls of the plenum. The connecting plate 46 is attached to the top wall 14 of the conveyor channels 12 and to the side walls 42 of the plenum. The connecting plate is employed in connecting together adjacent lengths of the air conveyor end to end. The connecting plate is attached to the conveyor channels top wall 14 by threaded fasteners (not shown) and is also connected to the plenum side walls 42 by threaded fasteners (not shown). When the connecting plate overlays air conduits of the conveyor channels 12 , holes are provided through the plate in order to maintain communication of the pressurized air in the air plenum 38 with the conveyor channel air conduits and air ducts.
Suspended below the air conveyor 10 are a plurality of brackets 52 . As shown in FIG. 1, each bracket 52 has a general U-shaped configuration and its top ends are attached to the undersides of the outer most side wall lower sections 18 of the conveyor channels 12 by threaded fasteners. The brackets 52 are spacially arranged along the length of the air conveyor 10 . As shown in FIG. 1, pairs of supports 54 are attached to the bottom of the brackets 52 . Each pair of supports 54 projects upwardly and is centered below the slots 34 of each of the conveyor channels 12 . The spacing between each pair of supports 54 is sufficiently large to provide ample clearance for a bottle container 24 to pass therethrough as is shown in FIG. 1 .
Guide rails 56 are mounted to the supports 54 . Pairs of guide rails 56 are positioned within the pairs of supports 54 mutually opposing each other. The guide rails 56 extend along the length of the air conveyor 10 and can be provided in sections that are positioned end to end along the length of the air conveyor 10 in the same manner that sections of the air conveyor are positioned end to end. The guide rails 56 limit the extent of side to side movement of bottles 24 conveyed by the air conveyor 10 and prevent bottles from becoming jammed in the air conveyor by excessive side to side movement.
The air conveyor 10 , the series of brackets 52 and the supports 54 and guide rails 56 are all suspended from a framework 58 . The framework 58 extends along and supports the entire length of the air conveyor 10 . Although only a short, straight length of the air conveyor 10 is shown in FIGS. 1 and 2, air conveyors are constructed with substantial lengths that can curve from side to side and incline upwardly and downwardly along their lengths.
The air conveyor described to this point is conventional and many of the component parts of the air conveyor described are found in various different types of air conveyors. It should be understood that the air conveyor described is only one operative environment of the braking system and that the braking system may be employed in different types of air conveyors having constructions that are different from the construction of the air conveyor described herein. The air conveyor 10 is only one operative environment of the braking system and the braking system is not limited to use with air conveyors of the type described.
The braking system of the invention is designed to enable it to be easily retrofit to existing air conveyors by attaching it to the guide rail brackets 52 and supports 54 of an existing air conveyor, or by including brackets and supports with the braking system that enable it to be attached to the side walls 16 of the conveyor channels 12 . Although the braking system will be described as being employed with a multi-channel air conveyor, it is equally well-suited for use with a single channel air conveyor.
The braking system of the present invention is basically comprised of a stop 62 that is supported by three mounts 64 , 66 , 68 adjacent a guide rail of an air conveyor channel, and an actuator 72 that selectively moves the stop 62 a short distance into the spacing between opposed guide rails of the conveyor channel to reduce the spacing of the conveyor pathway between the guide rails and stop bottles conveyed through this portion of the pathway. FIG. 1 shows a downstream mount 68 of the three mounts of the braking system on one of the supports 54 of the conveyor guide rails 56 . FIG. 1 illustrates the ability of mounting the braking system at different elevations adjacent the guide rails 56 in order to best position the braking system for engagement with a generally flat portion of the bottle body to obtain the optimum performance of the braking system. In the preferred embodiment of the invention, it is only necessary to mount the braking system on one side of the pathway defined between the pair of opposed guide rails 56 . When the stop 62 of the braking system is extended outwardly into this pathway by actuation of the actuator 72 , the spacing between the braking system stop and the opposite guide rail is reduced to the extent that a bottle 24 cannot pass through the pathway and is stopped. Pairs of the braking systems to be described could be mounted adjacent the pairs of guide rails 56 that define each pathway of the air conveyor, but only one braking system is needed to operate properly and therefore only one braking system mounted on one side of the pathway defined by the guide rails 56 will be described.
FIG. 2 shows a side view of the braking system of the invention installed along a length of the air conveyor 10 and FIG. 3 shows a fragmented view of the side of the conveyor shown in FIG. 2 and also shows an enlargement of the component parts of the braking system. Again, it is pointed out that the braking system is installed on one side of the pathway defined by opposed guide rails 56 and one guide rail of the pair of opposed guide rails is positioned on the opposite side of the conveyor pathway from the braking system.
The three mounts of the braking system include an upstream mount 64 , an intermediate mount 66 , and a downstream mount 68 . Each of the mounts is secured to one of the air conveyor supports 54 just above the guide rail 56 supported by the support. Each of the mounts could also be mounted below the guide rail if required by the shape of the bottles. The upstream and downstream mounts have basically the same construction and the construction of the intermediate mount is only slightly different from the other two. The upstream mount 64 is mounted to its support 54 in a reversed orientation from the orientations of the intermediate mount 66 and the downstream mount 68 . Because the upstream and downstream mounts have the same basic construction, only the construction of the upstream mount 64 will be described with it being understood the component parts of the downstream mount 68 are the same and are identified by the same reference numbers. The upstream mount 64 has a general C-shape with an upper arm 74 and lower arm 76 that are vertically spaced from each other. The spacing is sufficient to accommodate a portion of the stop 62 therein, as will be described. The opposite end of the mount 64 from its projecting arms 74 , 76 is mounted to the support 54 on the same side of the support as the guide rail 56 . This positions the mount just above the guide rail. As shown in FIGS. 4 and 5, the mount has a transverse width that is substantially equal to that of the guide rail 56 so that it does not project out into the pathway of the conveyed bottles any more than does the guide rail. The mount is preferably attached to the support 54 by threaded fasteners (not shown). At the opposite end of the mount 64 , a pivot pin 78 extends through the distal ends of the arm 74 , 76 across the spacing between the arms.
The intermediate mount 66 is also attached to one of the guide rail supports 54 but in an orientation that is the reverse of that of the upstream mount 64 . Like the upstream mount, the intermediate mount 66 has an upper arm 74 ′ and lower arm 76 ′ separated by a vertical spacing and a pivot pin 78 ′ spanning the spacing at the distal ends of the arms. However, the intermediate mount 66 differs from both the upstream mount 64 and the downstream mount 68 in that it is not formed in a general C-shape. Instead it is formed with the upper and lower arms 74 , 76 being separated from each other by the spacing between the arms. Unlike the upstream mount 64 and downstream mount 68 , the spacing between the arms of the intermediate mount 66 extends along the entire length of the mount 66 . This enables sections of the stop 62 to be described to be positioned between the two arms 74 ′, 76 ′ of the intermediate mount 66 . As an alternative, the arms of the intermediate mount 66 could be formed as one-piece with a slot extending along the entire length of the mount that is dimensioned to receive sections of the stop to be described within the slot and between the two arms. Like the upstream mount 64 , the two separate arms 74 ′, 76 ′ of the intermediate mount 66 are attached to the guide rail support 54 by threaded fasteners (not shown).
The downstream mount 68 is similar to the upstream mount 64 except that its orientation mounted on the guide rail support 54 is reversed from the upstream mount. It also includes a pair of arms 74 , 76 that are separated by a vertical spacing. A pivot pin 78 passes through the arms at their distal ends and spans the spacing between the arms. The mount 68 is secured to the guide rail support 54 by threaded fasteners (not shown).
A reinforcement rod 92 extends across the tops of the three mounts 64 , 66 , 68 and is secured thereto by threaded fasteners (not shown). The reinforcement rod 92 adds rigidity to the braking system.
The stop 62 of the braking system that is selectively extended into and retracted from the pathway defined by the pair of guide rails 56 is constructed of first 94 and second 96 elongated, articulated bar sections that together form a rail similar to the guide rails. The two bar sections 94 , 96 have transverse width and vertical height dimensions substantially the same as those of the guide rails 56 . Referring to FIGS. 3-5, the first bar section 94 has opposite upstream 98 and downstream 102 ends. A hole 104 passes vertically through the first bar section 94 adjacent its upstream end 98 . As seen in FIGS. 4 and 5, the hole 104 has an oblong shape and extends along the end of the first bar section 94 in a direction generally parallel with the length of the first bar section. The opposite downstream end 102 of the first bar section is connected by an articulation joint to the upstream end 106 of the second bar section 96 . The downstream end 102 of the first bar section is formed with a center pivot knuckle and the upstream end 106 of the second bar section is formed with a pair of vertically spaced knuckles that receive the center knuckle of the first bar section therebetween. A pivot pin 108 passes through these three knuckles and provides the pivot connection of the articulation joint between the two bar sections. An oblong slot 112 also passes vertically through the second bar section 96 adjacent its upstream end 106 . A similar oblong slot 114 passes vertically through the second bar section 96 adjacent its downstream end 116 . Both oblong slots 112 , 114 have lengths that extend in a direction oriented at an angle relative to the center axis of the length of the second bar section 96 .
The pivot pin 78 through the upstream mount 64 also passes through the hole 104 at the upstream end 98 of the first bar section 94 . The pivot pin 78 ′ of the intermediate mount 66 passes through the oblong slot 112 at the upstream end 106 of the second bar section 96 . The pivot pin 78 of the downstream mount 68 passes through the oblong slot 114 at the downstream end 116 of the second bar section 96 . In this manner, the two bar sections 94 , 96 of the stop 62 are supported by the three mounts 64 , 66 , 68 above the guide rail 56 of the air conveyor. Again, they could also be mounted below the guide rails.
The actuator 72 in the preferred embodiment of the invention is a linear actuator. In the preferred embodiment, the linear actuator is a double-acting pneumatic piston and cylinder. Other types of linear actuators may be employed as the actuator for the braking system. In addition, it is not necessary that the actuator be a linear actuator as a rotary actuator may also be employed to operate the braking system. The actuator includes a cylinder 122 with a piston (not shown) mounted therein for reciprocating movement. A piston rod 124 extends from the cylinder. A retraction air inlet 126 is provided at one end of the cylinder and an extension air inlet 128 is provided at the opposite end of the cylinder. The right-hand end of the cylinder 122 as viewed in FIGS. 2-5 is mounted by a pivot connection 132 to a brace 134 that in turn is secured to the mount 68 at the downstream end, or right-hand end of the braking system as shown in the drawing figures. The piston rod 124 is connected by a pivot connection 136 to a brace 138 that is secured to the second bar section 96 of the braking system stop. Two separate hoses (not shown) are connected to the retraction air inlet 126 and the extension air inlet 128 of the cylinder 122 and are selectively supplied with air to control the retraction of the piston rod 124 into the cylinder 122 and the extension of the piston rod from the cylinder, respectively.
The operation of the braking system is illustrated in FIGS. 4 and 5. In FIGS. 4 and 5, the guide rail 56 opposite the braking system is represented by a dashed line with the path of conveyance of bottle containers being between the braking systems shown in the drawing figures and the dashed line representation of the guide rail 56 . The direction of conveyance from the upstream end to the downstream end of the path of conveyance is from left to right in the drawing figures.
FIG. 4 shows the braking system in its retracted position relative to the guide rails 56 . From this view, it can be seen that neither the first bar section 94 or the second bar section 96 of the stop extends into the pathway defined between the pair of guide rails 56 . Therefore, the braking system would not interfere with the free conveyance of bottles through the pathway defined by the guide rails.
FIG. 5 shows the positions of the first bar section 94 and the second bar section 96 when air pressure has been supplied to the extension air inlet 128 of the actuator cylinder 122 . This causes the piston rod 124 to be extended from the cylinder 122 . The extension of the piston rod causes the second bar section 96 to move in a translatory movement controlled by the sliding of the intermediate mount pin 78 ′ and downstream mount pin 78 through the oblong slots 112 , 114 at the opposite, ends of the second bar section. The angled orientation of the two oblong slots 112 , 114 at the opposite ends of the second bar section 96 relative to its center axis causes the second bar section 96 to move in a translatory movement in the upstream direction, or to the left as viewed in FIG. 5, while simultaneously moving transversely relative to the flow path of the conveyed bottles between the guide rails 56 , thus reducing the spacing between the opposite guide rail 56 shown as a dashed line in FIG. 5 and the second bar section 96 . The second bar section 96 moves in this translatory manner until the two pins 78 ′, 78 of the intermediate mount 66 and the downstream mount 68 reach the ends of the angled oblong slots 112 , 114 as shown in FIG. 5 .
As the second bar section 96 moves in its translatory movement, it imparts motion to the first bar section 94 due to the articulated joint connection provided by the pivot pin 108 connecting these two sections. The downstream end 102 of the first bar section 94 follows the translatory movement of the upstream end 106 of the second bar section 96 due to the articulating connection provided by the pivot pin 108 . However, the movement of the upstream end 98 of the first bar section 94 is controlled by the pivot pin 78 of the upstream mount 64 passing through the oblong hole 104 and the orientation of the hole along the center axis of the first bar section 94 . As the first bar section 94 is caused to move to the left or in an upstream direction by the movement of the second bar section 96 , the hole 104 slides along the pivot pin 78 of the upstream mount 64 and causes the upstream end 98 of the first bar section to pivot about the pin. This gives the first bar section 94 an angled orientation relative to the guide rail 56 opposite the braking system. In addition, the angled orientation of the first bar section 94 causes the transverse width of the flow path of the conveyed bottles to gradually decrease as that flow path extends downstream from the upstream end 98 of the first bar section to its downstream end 102 .
It can be seen from FIG. 5 that as bottles are conveyed in the downstream direction with the first and second bar sections 94 , 96 of the stop extended, the spacing between the bottle and the opposite guide rail 56 represented by the dashed line in 56 and between the bottle and the first and second bar sections 94 , 96 gradually decreases until the bottle reaches the articulation joint 108 between the first and second bar sections. This gradual decrease in the spacing functions to gradually slow the speed of the bottle being conveyed past the extended braking system until it reaches the second bar section 96 where the friction force between the second bar section and the guide rail represented by the dashed line on opposite sides of the conveyed bottle gradually brings the bottle to a stop. Because subsequently conveyed bottles will be gradually slowed, and stopped in the same manner, the earlier described problems associated with prior art bottle braking gates such as damaging the forward most stopped bottles or forcing these bottles through the braking gates are eliminated.
To again start the stream of conveyed bottles, the air supply to the extension air inlet 128 is removed and air is supplied to the retraction air inlet 126 causing the piston rod 124 to be retracted back into the cylinder 122 . This pulls the first bar section 94 and second bar section 96 to the right, or in the downstream direction, causing them to move to their positions shown in FIG. 4 where they are both positioned outside the spacing between the opposing pairs of guide rails 56 .
Although in the preferred embodiment of the invention the stop is constructed of first and second articulated bar sections 94 , 96 , a variation of the braking system could include a single bar section with its upstream end mounted as the upstream end of the first bar section 94 and the downstream end mounted as the downstream end of the second bar section 96 in the abovedescribed embodiment, thus eliminating the articulation joint between the two sections and the mounting of the second section to the intermediate mount 66 .
While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.
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A braking system is provided along one of a pair of guide rails of an air conveyor that transports plastic bottles along a pathway between the pair of guide rails. The braking system is selectively actuated to move into the pathway defined by the guide rails decreasing its width and positioning a stop of the braking system in the pathway where it will engage with bottles conveyed by the air conveyor slowing and eventually stopping the bottles.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to baseball and softball bats. More particularly, the present invention relates to a multi-component bat and a related assembly process.
[0002] Baseball and softball are very popular sports in the United States, Mexico, Cuba, Japan and elsewhere. Due to the competitive nature of the sports, players are constantly seeking ways of improving their performance. An important aspect of baseball and softball is the ability to effectively hit the ball. Aluminum (metal) bats are allowed in baseball amateur play from Little League to College levels. Metal bats are also typically used in slow and fast pitch softball. Such bats are advantageous over wood bats in that they do not break and splinter like wood bats and thus can be repeatedly used with consequent cost savings. Metal bats also have a larger optimal hitting area or power zone (commonly referred to as the “sweet spot”) than wood bats. Furthermore, the ball comes off a metal bat faster than a wood bat resulting in longer hits.
[0003] However, metal bats have certain disadvantages. Metal bats vibrate upon impact and may send painful vibrations into the hands and arms of the batter if the ball is not hit within the power zone of the bat. Metal bats, particularly aluminum bats, may also dent or otherwise deform due to forceful impacts with the ball. Metal bats also emit an undesirable high-pitched metallic sound, as opposed to the traditional sound heard when a wood bat contacts the ball.
[0004] Various attempts have been made to overcome the problems associated with metal bats. Some attempts have been to coat or wrap the exterior of the metal bat with materials such as carbon reinforcing fibers to enhance batting performance. These externally wrapped bats have been found to be aesthetically unpleasant and lacking in significant improvement. Other attempts have been made to insert internal layers or compartments within the metal bat to improve performance. Bats have been devised that incorporate both metal and composite materials. Such designs include utilizing multiple-layered graphite inserts to provide durability and flexibility to the bat, tubular coiled spring steel inserts to improve the spring-board effect when the ball contacts the bat, and pressurized air chambers within the bat. Bats that incorporate composite materials tend to be much lighter than metal bats. While providing benefits, these designs also have drawbacks. Some designs are very expensive to manufacture and are prone to structural failure. The composite sheaths break down over time, the bats are subject to premature longitudinal cracks in the barrel of the bat and damage is created at an interface of the metal and composite materials due to differences in the impact absorption and resistance characteristics of the materials.
[0005] Accordingly, there is a need for a bat which enhances the performance of the bat and overcomes the disadvantages previously experienced with metal bats. The present invention fulfills these needs and provides other related advantages.
SUMMARY OF THE INVENTION
[0006] The present invention resides in an apparatus and process that provides a multi-component bat. As illustrated herein, a multi-component baseball bat embodying the present invention includes an elongate composite handle having opposite first and second ends. The bat further includes an elongate barrel having opposite first and second ends, the first end of the barrel being disposed within the second end of handle. A mechanism is provided for securing the first end of the barrel within the second end of the handle. The bat also includes a ring disposed near the second end of the barrel, and a rigid sleeve encircling the second end of the handle and extending toward the first end of the handle.
[0007] The sleeve is adhered to an exterior of the handle and barrel. The sleeve comprises, at least in part, an intermediate tapered section between the barrel and handle.
[0008] The securing mechanism includes a section of the handle enveloping an end of the barrel. The securing mechanism also includes an annular recess in the handle for receiving the sleeve therein.
[0009] A portion of the handle is disposed between the sleeve and barrel. The first end of the barrel and the second end of the handle threadedly engage each other. The bat includes a layer of adhesive disposed between the first end of the barrel and the second end of the handle.
[0010] A cap is disposed on the second end of the barrel with the ring coaxially disposed within the cap such that the ring and sleeve contain vibrations within the barrel.
[0011] The process for assembling a multi-component baseball bat includes disposing a rigid sleeve coaxially over a portion of an elongate composite handle, the rigid sleeve encircling a second end of the handle and extending toward a first end of the handle. A ring is positioned near the second end of the bat barrel. As part of the process, a first end of a bat barrel is inserted into the second end of the handle; the first end of the bat barrel being secured within the second end of the handle.
[0012] A section of the barrel is enveloped within the second end of the handle. Disposing the rigid sleeve over the handle includes having formed the rigid sleeve and then molding the handle with the sleeve. The sleeve is received within an annular recess in the handle.
[0013] Securing the barrel and handle together adhering the barrel to the handle. In addition, the barrel can be adhered to the sleeve. Securing the barrel and handle together can also be accomplished by threadedly engaging the first end of the barrel and the second end of the handle to define an intermediate tapered section.
[0014] A continuous tapered exterior surface of the baseball bat is formed by engagement of the barrel, handle and sleeve.
[0015] A grip can be attached to the handle and a cap disposed over an open second end of the bat barrel.
[0016] 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 DRAWINGS
[0017] The accompanying drawings illustrate the invention. In such drawings:
[0018] FIG. 1 is a perspective view of a baseball bat embodying the present invention;
[0019] FIG. 2 is an exploded perspective view of a bat barrel, bat handle, and interconnecting mechanism of the baseball bat of FIG. 1 ;
[0020] FIG. 3 is an enlarged view of area 3 of an embodiment of the bat of FIG. 2 ;
[0021] FIG. 4 is cross-sectional view taken generally along the line 4 - 4 of FIG. 1 ;
[0022] FIG. 5 is an enlarged view of area 5 of another embodiment of the bat of FIG. 2 ;
[0023] FIG. 6 is cross-sectional view taken generally along the line 6 - 6 of FIG. 1 ;
[0024] FIG. 7 is an enlarged view of area 7 of yet another embodiment of the bat of FIG. 2 ;
[0025] FIG. 8 is cross-sectional view taken generally along the line 8 - 8 of FIG. 1 ;
[0026] FIG. 9 is an enlarged view of area 9 of the bat of FIG. 2 illustrating attachment of an end plug to the bat barrel;
[0027] FIG. 10 is an enlarged view of area 10 of the bat of FIG. 1 illustrating the end plug on the bat barrel;
[0028] FIG. 11 is a cross-sectional view taken generally along the line 11 - 11 of FIG. 10 ;
[0029] FIG. 12 is a perspective view of still another baseball bat embodying the present invention;
[0030] FIG. 13 is an exploded perspective view of a bat barrel, bat handle, and interconnecting mechanism of the baseball bat of FIG. 12 ;
[0031] FIG. 14 is an enlarged view of area 14 of the bat of FIG. 13 ;
[0032] FIG. 15 is a top perspective view of a fluted ring used with the bat of FIG. 12 ;
[0033] FIG. 16 is cross-sectional view taken generally along the line 16 - 16 of FIG. 12 ;
[0034] FIG. 17 is an enlarged view of area 17 of the bat of FIG. 13 illustrating attachment of an end plug to the bat barrel;
[0035] FIG. 18 is an enlarged view of area 18 of the bat of FIG. 12 illustrating the end plug on the bat barrel; and
[0036] FIG. 19 is a cross-sectional view taken generally along the line 19 - 19 of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] As shown in FIGS. 1-11 for purposes of illustration, the present invention is concerned with a multi-component bat 20 , 70 , 120 for use in baseball or softball.
[0038] In one embodiment of the present invention, as seen in FIGS. 1-4 , and 9 - 11 , the multi-component bat 20 has an elongate hollow handle shell portion 22 , an elongate hollow barrel shell portion 24 and an intermediate cylindrically tapered section 26 interconnecting the handle portion 22 and the barrel portion 24 . A knob 28 is securely attached to an end of the handle portion 22 by a variety of means including, without limitation, bonding agents, glues, adhesives or the like. The knob 28 may be made of various materials including, without limitation, aluminum, magnesium, polyurethane, polycarbonate, a composite material, Zytel, Delrin, plastic or the like. Also, the handle portion 22 is typically wrapped with a grip 30 comprised of rubber, polyurethane, leather or the like, for comfort. The construction of the intermediate tapered section 26 dampens vibrations created when a ball contacts the bat 20 and provides limited pivotal movement of the barrel portion 24 relative to the handle portion 22 (i.e., a flex measured in microns).
[0039] The handle and barrel portions 22 , 24 may be made of various materials including, without limitation, wood, a lightweight yet durable metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers (e.g., 50/50 glass to carbon, 80/20 glass to carbon for a very flexible bat, 20/80 glass to carbon for a very stiff bat or any other ratio of glass to fiber in order to obtain a desired flex in the bat 20 )) or the like. Each of the portions 22 , 24 may be made of the same material or they may be made of different materials. Preferably, the handle portion 22 is comprised of a composite material and the barrel portion 24 is comprised of a 6000 or 7000 series aluminum alloy in which zinc is the major alloying element coupled with a smaller percentage of magnesium, resulting in a heat-treatable alloy of very high strength. The barrel portion 24 is finished to a mechanical strength of T6/T7 Temper. In the alternative, the handle and barrel portions 22 , 24 may both be made of composite materials (of equal or differing hardness) or metal (of equal of differing hardness). In another alternative, the barrel portion 24 may be made of a composite material, such as those described above, and the handle portion 22 made of a metal, such as those described above.
[0040] The handle and barrel portions 22 , 24 each include a tapered first end 32 , 34 having an aperture 36 , 38 . The intermediate tapered section 26 of the bat 20 is defined, at least in part, when an interior surface of the tapered first end 32 of the handle portion 22 includes an adhesive layer 40 that engages an adhesive layer 42 on an exterior surface of the tapered first end 34 of the barrel portion 24 . A section of the handle portion 22 envelopes the end 34 of the barrel portion 24 with the adhesive layers 40 , 42 disposed between the first end 34 of the barrel portion 24 and the first end 32 of the handle portion 22 . Preferably, the length of the adhesive section takes up approximately 10%-75% of the length of the tapered section 26 . The adhesive engagement of the handle and barrel portions 22 , 24 coaxially interconnects the handle and barrel portions 22 , 24 , in an aligned relation in order to provide impact absorption and reduce stress on an interface section 44 of the handle and barrel portions 22 , 24 which forms a portion of the intermediate tapered section 26 of the bat 20 .
[0041] The stress on the interface section 44 results from repeated impacts of a ball on the bat 20 . The intermediate tapered section 26 deflects vibrations traveling from the barrel portion 24 to the handle portion 22 ; deflecting the energy of the vibrations back into the barrel portion 24 . The deflected energy is transmitted, at least in part, back to the ball.
[0042] The intermediate section 26 includes a rigid cylindrically tapered ring or sleeve 46 attached to the first end 32 of the handle portion 22 . The sleeve 46 comprises, at least in part, the intermediate tapered section 26 between the barrel and handle portions 24 , 22 . The sleeve 46 , in the form of a hollow, exteriorly tapered sleeve, is coaxially disposed around an exterior of the first end 32 of the handle portion 22 . The sleeve 46 is coaxially disposed between the barrel portion 24 and the handle portion 22 for interconnecting the barrel and handle portions 24 , 22 in an aligned relation, to return energy and power to the barrel portion 24 that emanates from the barrel portion 24 due to an impact of a ball (not shown) on the barrel portion 24 .
[0043] The handle portion 22 includes a cylindrical guide 48 in the handle portion 22 for receiving the sleeve 46 thereabout. The guide 48 extends a distance longitudinally from the first end 32 of the handle portion 22 towards a second, opposite end 50 of the handle portion 22 where the knob 28 is located. The aperture 36 of the first end 32 of the handle portion 22 is the entrance to an interior portion 52 of the guide 48 that extends into the handle portion 22 . The sleeve 46 includes a central bore 54 having first and second tapered ends 56 , 58 . The cylindrical interior diameter of the bore 54 of the sleeve 46 closely matches the cylindrical exterior diameter of the tapered guide 48 in order to provide tight engagement of the sleeve 46 and guide 48 . The sleeve 46 is also adhered about the guide 48 by a conventional adhesive, glue or bonding agent 60 . When the handle portion 22 engages the barrel portion 24 , the glue or bonding agent 60 also adheres the sleeve 46 to the exterior of the barrel portion 24 . The guide 48 and the tapered first end 34 of the barrel portion 24 each define, in part, an annular recess 62 of the intermediate section 26 of the bat 20 . The first and second tapered ends 56 , 58 of the sleeve 46 engage tapered ends of the recess 62 such that a continuous exterior surface of the bat 20 is formed. When the handle portion 22 engages the barrel portion 24 , a portion of the end 32 of the handle portion 22 is disposed between the sleeve 46 and the barrel portion 24 .
[0044] The engagement of the barrel portion 24 , the handle portion 22 and the sleeve 46 provides a generally continuous exterior surface of the baseball bat 20 . This is, at least partially, because the angle of the tapered exterior surface of the sleeve 46 matches the angles of the tapered first ends 32 , 34 of the handle and barrel portions 22 , 24 ; the angle of the first tapered ends 32 , 34 being between zero and forty-five degrees.
[0045] The sleeve 46 is comprised of polyurethane, or polycarbonate, a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers), metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), or an elastomeric material (e.g., solid rubber, high performance rubber foam, silicone or similar materials). The sleeve 46 can be made of transparent material (colored or non-colored) or an opaque material (colored or non-colored). The sleeve 46 may be solid or partially hollowed out to decrease its weight.
[0046] The bat 20 may be assembled in a number of ways. In one particular way, the handle portion 22 is mated with the barrel portion 24 by adhering the sleeve 46 about the guide 48 . The first end 34 of the barrel portion 24 is inserted through the aperture 36 of the open first end 32 of the handle portion 22 with the adhesive layers 40 , 42 bonding the barrel portion 24 to the handle portion 22 once the barrel portion 24 engages the sleeve 46 and can travel no further into the interior portion 52 of the handle portion 22 . The securement of the handle and barrel portions 22 , 24 , with the sleeve 46 disposed therebetween in the recess 62 formed thereby, provides a generally continuous exterior surface of the baseball bat 20 when the handle portion 22 engages the barrel portion 24 .
[0047] The components of the intermediate tapered section 26 tightly fit together to isolate vibrations which insulates the handle portion 22 from vibrations generated in the barrel portion 24 when a ball strikes the barrel portion 24 . The length of the intermediate tapered section 26 will be varied based on the size and type of bat (e.g., adult baseball bat, youth baseball bat, softball bat or the like). The high strength bonding agent 60 (e.g. rubberized glue, rubber cement, etc.) may be applied to all joins to secure all the connections. The bonding agent 60 helps to dampen vibrations, fill in gaps and allow additional flexibility. The flexibility of the bonding agent 60 helps to give the bat 20 a whipping effect since the two materials that form, respectively, the handle and barrel portions 22 , 24 flex at different rates (the barrel portion 24 flexing more than the handle portion 22 ) and the bonding agent 60 provides a flexible cushion along the interface of the sleeve 46 , handle portion 22 and barrel portion 24 .
[0048] A second end 64 of the barrel portion 24 is typically open and directed inward for acceptance and retention of a rigid cap or end plug 66 that increases the rigidity of the bat 20 . The end plug 66 is typically comprised of urethane, polyurethane, Zytel or the like. The end plug 66 has a circumferential outer groove 68 which accepts an inwardly directed annular lip 70 of the barrel portion 24 . The end plug 66 is then secured to the end 64 of the barrel portion 24 by inserting a number pairs of keys 72 disposed on opposite sides of the end plug 66 into slots or keyholes 74 disposed on opposite sides of the lip 72 and rotating the end plug 66 therein. Bonding agent 60 may be used to secure the end plug 66 in position. A recess 76 is formed on a top surface of the end plug 66 in order to allow a tool having a complimentary shape to the recess 76 engage the end plug 66 in order to secure the end plug 66 within the barrel 24 . The end plug 66 includes a circumferential inner groove 78 within which a rigid ring 80 is at least partially disposed. The sleeve 46 at the intermediate section 26 blocks vibrations by itself, and in combination with the ring 80 within the end plug 66 , the sleeve 46 and the ring 80 interact to create a larger sweet spot along the length of the barrel 24 . The sleeve 46 and the ring 80 , disposed at opposite ends 34 , 64 of the barrel 24 , cooperate to contain vibrations that occur when a ball hits the bat 20 as well as channel those vibrations in order to increase the volume of a desirable “ping” sound that occurs from the ball hitting the bat 20 . The ring 80 is made of a 65 D polyurethane material that allows a softer durometer material to be used in the end plug 66 .
[0049] In another embodiment of the present invention, as seen in FIGS. 1 , 2 , 5 , 6 , and 9 - 11 , a multi-component bat 120 , similar to the bat 20 described above, has an elongate hollow handle shell portion 122 , an elongate hollow barrel shell portion 124 and an intermediate cylindrically tapered section 126 interconnecting the handle portion 122 and the barrel portion 124 . A knob 128 is securely attached to the end of the handle portion 122 by a variety of means including, but not limited to, bonding agents, glues, adhesives or the like. The knob 128 may be made of various materials including, without limitation, aluminum, magnesium, Zytel, Delrin, plastic, polyurethane, polycarbonate, a composite material or the like. Also, the handle portion 122 is typically wrapped with a grip 130 comprised of rubber, polyurethane, leather or the like, for comfort. The construction of the intermediate tapered section 126 dampens vibrations created when a ball contacts the bat 120 and provides limited pivotal movement of the barrel portion 124 relative to the handle portion 122 (i.e., a flex measured in microns).
[0050] The handle and barrel portions 122 , 124 may be made of various materials including, without limitation, wood, a lightweight yet durable metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers (e.g., 50/50 glass to carbon, 80/20 glass to carbon for a very flexible bat, 20/80 glass to carbon for a very stiff bat or any other ratio of glass to fiber in order to obtain a desired flex in the bat 120 )) or the like. Each of the portions 122 , 124 may be made of the same material or they may be made of different materials. Preferably, the handle portion 122 is comprised of a composite material and the barrel portion 124 is comprised of a 6000 or 7000 series aluminum alloy in which zinc is the major alloying element coupled with a smaller percentage of magnesium, resulting in a heat-treatable alloy of very high strength. The barrel portion 124 is finished to a mechanical strength of T6/T7 Temper. In the alternative, the handle and barrel portions 72 , 74 may both be made of composite materials (of equal or differing hardness) or metal (of equal of differing hardness). In another alternative, the barrel portion 124 may be made of a composite material, such as those described above, and the handle portion 122 made of a metal, such as those described above.
[0051] The handle and barrel portions 122 , 124 each include a tapered first end 132 , 134 having an aperture 136 , 138 . The intermediate tapered section 126 of the bat 120 is defined, at least in part, when the first end 134 of the barrel portion 124 and the first end 132 of the handle portion 122 threadedly engage each other. An interior surface of the tapered first end 132 of the handle portion 122 includes threads 140 that engage threads 142 on an exterior surface of the tapered first end 134 of the barrel portion 124 . A section of the handle portion 122 envelopes the end 134 of the barrel portion 124 with the engaged threads 140 , 142 disposed between the first end 134 of the barrel portion 124 and the first end 132 of the handle portion 122 . Preferably, the length of the threaded section takes up approximately 10%-75% of the length of the tapered section 126 . The threaded engagement of the handle and barrel portions 122 , 124 coaxially interconnects the handle and barrel portions 122 , 124 , in an aligned relation in order to provide impact absorption and reduce stress on an interface section 144 of the handle and barrel portions 122 , 124 which forms a portion of the intermediate tapered section 126 of the bat 120 . The stress on the interface section 144 results from repeated impacts of a ball on the bat 120 . The intermediate tapered section 126 deflects vibrations traveling from the barrel portion 124 to the handle portion 122 ; deflecting the energy of the vibrations back into the barrel portion 124 . The deflected energy is transmitted, at least in part, back to the ball.
[0052] The intermediate section 126 includes a rigid cylindrically tapered ring or sleeve 146 attached to the first end 132 of the handle portion 122 . The sleeve 146 comprises, at least in part, the intermediate tapered section 126 between the barrel and handle portions 124 , 122 . The sleeve 146 , in the form of a hollow, exteriorly tapered sleeve, is coaxially disposed around an exterior of the first end 132 of the handle portion 122 . The sleeve 146 is coaxially disposed between the barrel portion 124 and the handle portion 122 for interconnecting the barrel and handle portions 124 , 122 in an aligned relation, to return energy and power to the barrel portion 124 that emanates from the barrel portion 124 due to an impact of a ball (not shown) on the barrel portion 124 .
[0053] The handle portion 122 includes a cylindrical guide 148 in the handle portion 122 for receiving the sleeve 146 thereabout. The guide 148 extends a distance longitudinally from the first end 132 of the handle portion 122 towards a second, opposite end 150 of the handle portion 122 where the knob 128 is located. The aperture 136 of the first end 132 of the handle portion 122 is the entrance to an interior portion 152 of the guide 148 that extends into the handle portion 122 . The sleeve 146 includes a central bore 154 having first and second tapered ends 156 , 158 . The cylindrical interior diameter of the bore 154 of the sleeve 146 closely matches the cylindrical exterior diameter of the tapered guide 148 in order to provide tight engagement of the sleeve 146 and guide 148 . The sleeve 146 is also adhered about the guide 148 by a conventional adhesive, glue or bonding agent 160 . When the handle portion 122 engages the barrel portion 124 , the glue or bonding agent 160 also adheres the sleeve 146 to the exterior of the barrel portion 124 . The guide 148 and the tapered first end 134 of the barrel portion 124 each define, in part, an annular recess 162 of the intermediate section 126 of the bat 120 . The first and second tapered ends 156 , 158 of the sleeve 146 engage tapered ends of the recess 162 such that a continuous exterior surface of the bat 120 is formed. When the handle portion 122 engages the barrel portion 124 , a portion of the end 132 of the handle portion 122 is disposed between the sleeve 146 and the barrel portion 124 .
[0054] The engagement of the barrel portion 124 , the handle portion 122 and the sleeve 146 provides a generally continuous exterior surface of the baseball bat 120 . This is, at least partially, because the angle of the tapered exterior surface of the sleeve 146 matches the angles of the tapered first ends 132 , 134 of the handle and barrel portions 122 , 124 ; the angle of the first tapered ends 132 , 134 being between zero and forty-five degrees.
[0055] The sleeve 146 is comprised of polyurethane, or polycarbonate, a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers), metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), or an elastomeric material (e.g., solid rubber, high performance rubber foam, silicone or similar materials). The sleeve 146 can be made of transparent material (colored or non-colored) or an opaque material (colored or non-colored). The sleeve 146 may be solid or partially hollowed out to decrease its weight.
[0056] The bat 120 may be assembled in a number of ways. In one particular way, the handle portion 122 is mated with the barrel portion 124 by adhering the sleeve 146 about the guide 148 . The first end 134 of the barrel portion 124 is inserted through the aperture 136 of the open first end 132 of the handle portion 122 with the threads 140 , 142 engaging the barrel portion 124 to the handle portion 122 until the barrel portion 124 can travel no further into the interior portion 152 of the handle portion 122 . The securement of the handle and barrel portions 122 , 124 , with the sleeve 146 disposed therebetween in the recess 162 formed thereby, provides a generally continuous exterior surface of the baseball bat 120 when the handle portion 122 engages the barrel portion 124 .
[0057] The components of the intermediate tapered section 126 tightly fit together to isolate vibrations which insulates the handle portion 122 from vibrations generated in the barrel portion 124 when a ball strikes the barrel portion 124 . The length of the intermediate tapered section 126 will be varied based on the size and type of bat (e.g., adult baseball bat, youth baseball bat, softball bat or the like). The high strength bonding agent 160 (e.g. rubberized glue, rubber cement, etc.) may be applied to all joins to secure all the connections. The bonding agent 160 helps to dampen vibrations, fill in gaps and allow additional flexibility. The flexibility of the bonding agent 160 helps to give the bat 120 a whipping effect since the two materials that form, respectively, the handle and barrel portions 122 , 124 flex at different rates (the barrel portion 124 flexing more than the handle portion 122 ) and the bonding agent 160 provides a flexible cushion along the interface of the sleeve 146 , handle portion 122 and barrel portion 124 .
[0058] A second end 164 of the barrel portion 124 is typically open and directed inward for acceptance and retention of a rigid cap or end plug 166 that increases the rigidity of the bat 120 . The end plug 166 is typically comprised of urethane, polyurethane, Zytel or the like. The end plug 166 has a circumferential outer groove 168 which accepts an inwardly directed annular lip 170 of the barrel portion 124 . The end plug 166 is then secured to the end 164 of the barrel portion 124 by inserting a number pairs of keys 172 disposed on opposite sides of the end plug 166 into slots or keyholes 174 disposed on opposite sides of the lip 172 and rotating the end plug 166 therein. Bonding agent 160 may be used to secure the end plug 166 in position. A recess 176 is formed on a top surface of the end plug 166 in order to allow a tool having a complimentary shape to the recess 176 engage the end plug 166 in order to secure the end plug 166 within the barrel 124 . The end plug 166 includes a circumferential inner groove 178 within which a rigid ring 180 is at least partially disposed. The sleeve 146 at the intermediate section 126 blocks vibrations by itself, and in combination with the ring 180 within the end plug 166 , the sleeve 146 and the ring 180 interact to create a larger sweet spot along the length of the barrel 124 . The sleeve 126 and the ring 180 , disposed at opposite ends 134 , 164 of the barrel 124 , cooperate to contain vibrations that occur when a ball hits the bat 120 as well as channel those vibrations in order to increase the volume of a desirable “ping” sound that occurs from the ball hitting the bat 120 . The ring 180 is made of a 65 D polyurethane material that allows a softer durometer material to be used in the end plug 166 .
[0059] In another embodiment of the present invention, as seen in FIGS. 1 , 2 and 7 - 11 , the multi-component bat 220 , similar to the bat 20 , 120 described above, has an elongate hollow handle shell portion 222 , an elongate hollow barrel shell portion 224 and an intermediate cylindrically tapered section 226 interconnecting the handle portion 222 and the barrel portion 224 . A knob 228 is securely attached to the end of the handle portion 222 by a variety of means including, but not limited to, bonding agents, glues, adhesives or the like. The knob 228 may be made of various materials including, without limitation, aluminum, magnesium, Zytel, Delrin, plastic, polyurethane, polycarbonate, a composite material or the like. Also, the handle portion 222 is typically wrapped with a grip 230 comprised of rubber, polyurethane, leather or the like, for comfort. The construction of the intermediate tapered section 226 dampens vibrations created when a ball contacts the bat 220 and provides limited pivotal movement of the barrel portion 224 relative to the handle portion 222 (i.e., a flex measured in microns).
[0060] The handle and barrel portions 222 , 224 may be made of various materials including, without limitation, wood, a lightweight yet durable metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers (e.g., 50/50 glass to carbon, 80/20 glass to carbon for a very flexible bat, 20/80 glass to carbon for a very stiff bat or any other ratio of glass to fiber in order to obtain a desired flex in the bat 220 )) or the like. Each of the portions 222 , 224 may be made of the same material or they may be made of different materials. Preferably, the handle portion 222 is comprised of a composite material and the barrel portion 224 is comprised of a 6000 or 7000 series aluminum alloy in which zinc is the major alloying element coupled with a smaller percentage of magnesium, resulting in a heat-treatable alloy of very high strength. The barrel portion 224 is finished to a mechanical strength of T6/T7 Temper. In the alternative, the handle and barrel portions 222 , 224 may both be made of composite materials (of equal or differing hardness) or metal (of equal of differing hardness). In another alternative, the barrel portion 224 may be made of a composite material, such as those described above, and the handle portion 222 made of a metal, such as those described above.
[0061] The handle and barrel portions 222 , 224 each include a tapered first end 232 , 234 having an aperture 236 , 238 . The intermediate tapered section 226 of the bat 220 is defined, at least in part, when the first end 234 of the barrel portion 224 and the first end 232 of the handle portion 212 engage each other. An interior surface of the tapered first end 232 of the handle portion 222 includes corrugations 240 that engage corrugations 242 on an exterior surface of the tapered first end 234 of the barrel portion 224 . The corrugations 240 , 242 absorb and block vibrations from traveling from the barrel to the handle. A section of the handle portion 222 envelopes the end 234 of the barrel portion 224 with the engaged corrugations 240 , 242 disposed between the first end 234 of the barrel portion 224 and the first end 232 of the handle portion 222 . Preferably, the length of the threaded section takes up approximately 10%-75% of the length of the tapered section 226 . The engagement of the respective corrugations 140 , 142 of the handle and barrel portions 222 , 224 coaxially interconnects the handle and barrel portions 222 , 224 , in an aligned relation in order to provide impact absorption and reduce stress on an interface section 244 of the handle and barrel portions 222 , 224 which forms a portion of the intermediate tapered section 226 of the bat 220 . The stress on the interface section 244 results from repeated impacts of a ball on the bat 220 . The intermediate tapered section 226 deflects vibrations traveling from the barrel portion 224 to the handle portion 222 ; deflecting the energy of the vibrations back into the barrel portion 224 . The deflected energy is transmitted, at least in part, back to the ball.
[0062] The intermediate section 226 includes a rigid cylindrically tapered ring or sleeve 246 attached to the first end 232 of the handle portion 222 . The sleeve 246 comprises, at least in part, the intermediate tapered section 226 between the barrel and handle portions 224 , 222 . The sleeve 246 , in the form of a hollow, exteriorly tapered sleeve, is coaxially disposed around an exterior of the first end 232 of the handle portion 222 . The sleeve 246 is coaxially disposed between the barrel portion 224 and the handle portion 222 for interconnecting the barrel and handle portions 224 , 222 in an aligned relation, to return energy and power to the barrel portion 224 that emanates from the barrel portion 224 due to an impact of a ball (not shown) on the barrel portion 224 .
[0063] The handle portion 222 includes a cylindrical guide 248 in the handle portion 222 for receiving the sleeve 246 thereabout. The guide 248 extends a distance longitudinally from the first end 232 of the handle portion 222 towards a second, opposite end 250 of the handle portion 222 where the knob 228 is located. The aperture 236 of the first end 232 of the handle portion 222 is the entrance to an interior portion 252 of the guide 238 that extends into the handle portion 222 . The sleeve 246 includes a central bore 254 having first and second tapered ends 256 , 258 . The cylindrical interior diameter of the bore 254 of the sleeve 246 closely matches the cylindrical exterior diameter of the tapered guide 248 in order to provide tight engagement of the sleeve 246 and guide 248 . The sleeve 246 is also adhered about the guide 248 by a conventional adhesive, glue or bonding agent 260 . When the handle portion 222 engages the barrel portion 224 , the glue or bonding agent 260 also adheres the sleeve 246 to the exterior of the barrel portion 224 . The guide 248 and the tapered first end 234 of the barrel portion 224 each define, in part, an annular recess 262 of the intermediate section 226 of the bat 220 . The first and second tapered ends 256 , 258 of the sleeve 246 engage tapered ends of the recess 262 such that a continuous exterior surface of the bat 220 is formed. When the handle portion 222 engages the barrel portion 224 , a portion of the end 232 of the handle portion 222 is disposed between the sleeve 246 and the barrel portion 224 .
[0064] The engagement of the barrel portion 224 , the handle portion 222 and the sleeve 246 provides a generally continuous exterior surface of the baseball bat 220 . This is, at least partially, because the angle of the tapered exterior surface of the sleeve 246 matches the angles of the tapered first ends 232 , 234 of the handle and barrel portions 222 , 224 ; the angle of the first tapered ends 232 , 234 being between zero and forty-five degrees.
[0065] The sleeve 246 is comprised of polyurethane, or polycarbonate, a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers), metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), or an elastomeric material (e.g., solid rubber, high performance rubber foam, silicone or similar materials). The sleeve 246 can be made of transparent material (colored or non-colored) or an opaque material (colored or non-colored). The sleeve 246 may be solid or partially hollowed out to decrease its weight.
[0066] The bat 220 may be assembled in a number of ways. In one particular way, the handle portion 222 is mated with the barrel portion 224 by adhering the sleeve 246 about the guide 248 . The first end 234 of the barrel portion 224 is inserted through the aperture 236 of the open first end 232 of the handle portion 222 with the corrugations 240 , 242 engaging the barrel portion 224 to the handle portion 222 until the barrel portion 224 can travel no further into the interior portion 252 of the handle portion 222 . The securement of the handle and barrel portions 222 , 224 , with the sleeve 246 disposed therebetween in the recess 262 formed thereby, provides a generally continuous exterior surface of the baseball bat 220 when the handle portion 222 engages the barrel portion 224 .
[0067] The components of the intermediate tapered section 226 tightly fit together to isolate vibrations which insulates the handle portion 222 from vibrations generated in the barrel portion 224 when a ball strikes the barrel portion 224 . The length of the intermediate tapered section 226 will be varied based on the size and type of bat (e.g., adult baseball bat, youth baseball bat, softball bat or the like). The high strength bonding agent 260 (e.g. rubberized glue, rubber cement, etc.) may be applied to all joins to secure all the connections. The bonding agent 260 helps to dampen vibrations, fill in gaps and allow additional flexibility. The flexibility of the bonding agent 260 helps to give the bat 220 a whipping effect since the two materials that form, respectively, the handle and barrel portions 222 , 224 flex at different rates (the barrel portion 224 flexing more than the handle portion 222 ) and the bonding agent 260 provides a flexible cushion along the interface of the sleeve 246 , handle portion 222 and barrel portion 224 .
[0068] A second end 264 of the barrel portion 224 is typically open and directed inward for acceptance and retention of a rigid cap or end plug 266 that increases the rigidity of the bat 220 . The end plug 266 is typically comprised of urethane, polyurethane, Zytel or the like. The end plug 266 has a circumferential outer groove 268 which accepts an inwardly directed annular lip 270 of the barrel portion 224 . The end plug 266 is then secured to the end 264 of the barrel portion 224 by inserting a number pairs of keys 272 disposed on opposite sides of the end plug 266 into slots or keyholes 274 disposed on opposite sides of the lip 272 and rotating the end plug 266 therein. Bonding agent 260 may be used to secure the end plug 266 in position. A recess 276 is formed on a top surface of the end plug 266 in order to allow a tool having a complimentary shape to the recess 276 engage the end plug 266 in order to secure the end plug 266 within the barrel 224 . The end plug 266 includes a circumferential inner groove 278 within which a rigid ring 280 is at least partially disposed. The sleeve 246 at the intermediate section 226 blocks vibrations by itself, and in combination with the ring 280 within the end plug 266 , the sleeve 246 and the ring 280 interact to create a larger sweet spot along the length of the barrel 224 . The sleeve 226 and the ring 280 , disposed at opposite ends 234 , 264 of the barrel 224 , cooperate to contain vibrations that occur when a ball hits the bat 220 as well as channel those vibrations in order to increase the volume of a desirable “ping” sound that occurs from the ball hitting the bat 220 . The ring 280 is made of a 65 D polyurethane material that allows a softer durometer material to be used in the end plug 266 .
[0069] In still another embodiment of the present invention, as seen in FIGS. 12-19 , a multi-component bat 320 , similar to the bat 20 , 120 , 220 described above, has an elongate hollow handle shell portion 322 , an elongate hollow barrel shell portion 324 and an intermediate cylindrically tapered section 326 interconnecting the handle portion 322 and the barrel portion 324 . A knob 328 is securely attached to an end of the handle portion 322 by a variety of means including, without limitation, bonding agents, glues, adhesives or the like. The knob 328 may be made of various materials including, without limitation, aluminum, magnesium, polyurethane, polycarbonate, a composite material, Zytel, Delrin, plastic or the like. Also, the handle portion 322 is typically wrapped with a grip 330 comprised of rubber, polyurethane, leather or the like, for comfort. The construction of the intermediate tapered section 326 dampens vibrations created when a ball contacts the bat 320 and provides limited pivotal movement of the barrel portion 324 relative to the handle portion 322 (i.e., a flex measured in microns).
[0070] The handle and barrel portions 322 , 324 may be made of various materials including, without limitation, wood, a lightweight yet durable metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers (e.g., 50/50 glass to carbon, 80/20 glass to carbon for a very flexible bat, 20/80 glass to carbon for a very stiff bat or any other ratio of glass to fiber in order to obtain a desired flex in the bat 320 )) or the like. Each of the portions 322 , 324 may be made of the same material or they may be made of different materials. Preferably, the handle portion 322 is comprised of a composite material and the barrel portion 324 is comprised of a 6000 or 7000 series aluminum alloy in which zinc is the major alloying element coupled with a smaller percentage of magnesium, resulting in a heat-treatable alloy of very high strength. The barrel portion 324 is finished to a mechanical strength of T6/T7 Temper. In the alternative, the handle and barrel portions 322 , 324 may both be made of composite materials (of equal or differing hardness) or metal (of equal of differing hardness). In another alternative, the barrel portion 324 may be made of a composite material, such as those described above, and the handle portion 322 made of a metal, such as those described above.
[0071] The handle and barrel portions 322 , 324 each include a tapered first end 332 , 334 having an aperture 336 , 338 . The intermediate tapered section 326 of the bat 320 is defined, at least in part, when an interior surface of the tapered first end 332 of the handle portion 322 includes an adhesive layer 340 that engages an adhesive layer 342 on an exterior surface of the tapered first end 334 of the barrel portion 324 . A section of the handle portion 322 envelopes the end 334 of the barrel portion 324 with the adhesive layers 340 , 342 disposed between the first end 334 of the barrel portion 324 and the first end 332 of the handle portion 322 . Preferably, the length of the adhesive section takes up approximately 10%-75% of the length of the tapered section 326 . The adhesive engagement of the handle and barrel portions 322 , 324 coaxially interconnects the handle and barrel portions 322 , 324 , in an aligned relation in order to provide impact absorption and reduce stress on an interface section 344 of the handle and barrel portions 322 , 324 which forms a portion of the intermediate tapered section 326 of the bat 320 .
[0072] The stress on the interface section 344 results from repeated impacts of a ball on the bat 320 . The intermediate tapered section 326 deflects vibrations traveling from the barrel portion 324 to the handle portion 322 ; deflecting the energy of the vibrations back into the barrel portion 324 . The deflected energy is transmitted, at least in part, back to the ball.
[0073] The intermediate section 326 includes a rigid cylindrically tapered ring or sleeve 346 attached to the first end 332 of the handle portion 322 . The sleeve 346 comprises, at least in part, the intermediate tapered section 26 between the barrel and handle portions 324 , 322 . The sleeve 346 , in the form of a hollow, exteriorly tapered sleeve having a fluted interior surface, is coaxially disposed around an exterior of the first end 332 of the handle portion 322 . A rubber or silicone ring 348 , disposed partially within the sleeve 346 , includes an exterior fluted surface that engages the interior fluted surface of the sleeve 346 . The sleeve 346 and ring 348 are coaxially disposed between the barrel portion 324 and the handle portion 322 for interconnecting the barrel and handle portions 324 , 322 in an aligned relation, to return energy and power to the barrel portion 324 that emanates from the barrel portion 324 due to an impact of a ball (not shown) on the barrel portion 324 .
[0074] The handle portion 322 includes a cylindrical guide 350 in the handle portion 322 for receiving the sleeve 346 and ring 348 thereabout. The guide 350 extends a distance longitudinally from the first end 332 of the handle portion 322 towards a second, opposite end 352 of the handle portion 322 where the knob 328 is located. The aperture 336 of the first end 332 of the handle portion 322 is the entrance to an interior portion 354 of the guide 350 that extends into the handle portion 322 . The sleeve 346 includes a central bore 356 having first and second tapered ends 358 , 360 . The ring 348 is disposed near the second end 360 . The cylindrical interior diameter of the bore 356 of the sleeve 346 and the interior diameter of the ring 348 closely matches the cylindrical exterior diameter of the tapered guide 350 in order to provide tight engagement of the sleeve 346 , ring 348 and guide 350 . The sleeve 346 and ring 348 are also adhered about the guide 350 by a conventional adhesive, glue or bonding agent 362 . When the handle portion 322 engages the barrel portion 324 , the glue or bonding agent 362 also adheres the sleeve 346 and the ring 348 to the exterior of the barrel portion 324 . The guide 350 and the tapered first end 334 of the barrel portion 324 each define, in part, an annular recess 364 of the intermediate section 326 of the bat 320 . The first and second tapered ends 358 , 360 of the sleeve 346 engage tapered ends of the recess 364 such that a continuous exterior surface of the bat 320 is formed. When the handle portion 322 engages the barrel portion 324 , a portion of the end 332 of the handle portion 322 is disposed between the sleeve 346 , the ring 348 and the barrel portion 324 .
[0075] The engagement of the barrel portion 324 , the handle portion 322 and the sleeve 346 provides a generally continuous exterior surface of the baseball bat 320 . This is, at least partially, because the angle of the tapered exterior surface of the sleeve 346 matches the angles of the tapered first ends 332 , 334 of the handle and barrel portions 322 , 324 ; the angle of the first tapered ends 332 , 334 being between zero and forty-five degrees.
[0076] The sleeve 346 is comprised of polyurethane, or polycarbonate, a composite material (e.g., fiberglass, carbon fibers, or a combination of glass and carbon fibers), metal (e.g., aluminum, titanium, magnesium, or an alloy thereof), or an elastomeric material (e.g., solid rubber, high performance rubber foam, silicone or similar materials). The sleeve 346 can be made of transparent material (colored or non-colored) or an opaque material (colored or non-colored). The sleeve 346 may be solid or partially hollowed out to decrease its weight.
[0077] The bat 320 may be assembled in a number of ways. In one particular way, the handle portion 322 is mated with the barrel portion 324 by adhering the sleeve 346 and the ring 348 about the guide 350 . The ring 348 may also be adhered to the sleeve 346 . The first end 334 of the barrel portion 324 is inserted through the aperture 336 of the open first end 332 of the handle portion 322 with the adhesive layers 340 , 342 bonding the barrel portion 324 to the handle portion 322 once the barrel portion 324 engages the sleeve 346 and ring 350 and can travel no further into the interior portion 354 of the handle portion 322 . The securement of the handle and barrel portions 322 , 324 , with the sleeve 346 and ring 348 disposed therebetween in the recess 364 formed thereby, provides a generally continuous exterior surface of the baseball bat 320 when the handle portion 322 engages the barrel portion 324 .
[0078] The components of the intermediate tapered section 326 tightly fit together to isolate vibrations which insulates the handle portion 322 from vibrations generated in the barrel portion 324 when a ball strikes the barrel portion 324 . The length of the intermediate tapered section 326 will be varied based on the size and type of bat (e.g., adult baseball bat, youth baseball bat, softball bat or the like). The high strength bonding agent 362 (e.g. rubberized glue, rubber cement, etc.) may be applied to all joins to secure all the connections. The bonding agent 362 helps to dampen vibrations, fill in gaps and allow additional flexibility. The flexibility of the bonding agent 362 helps to give the bat 320 a whipping effect since the two materials that form, respectively, the handle and barrel portions 322 , 324 flex at different rates (the barrel portion 324 flexing more than the handle portion 322 ) and the bonding agent 362 provides a flexible cushion along the interface of the sleeve 346 , the ring 348 , the handle portion 322 and the barrel portion 324 .
[0079] A second end 366 of the barrel portion 324 is typically open and directed inward for acceptance and retention of a rigid cap or end plug 368 that increases the rigidity of the bat 320 . The end plug 368 is typically comprised of urethane, polyurethane, Zytel or the like. The end plug 368 has a circumferential outer groove 370 which accepts an inwardly directed annular lip 372 of the barrel portion 324 . The end plug 368 is then secured to the end 366 of the barrel portion 324 by inserting a number pairs of keys 374 disposed on opposite sides of the end plug 368 into slots or keyholes 376 disposed on opposite sides of the lip 372 and rotating the end plug 368 therein. Bonding agent 362 may be used to secure the end plug 368 in position. A recess 378 is formed on a top surface of the end plug 368 in order to allow a tool having a complimentary shape to the recess 378 engage the end plug 368 in order to secure the end plug 368 within the barrel 324 . The end plug 368 includes a circumferential inner groove 380 within which a rigid ring 382 is at least partially disposed. The sleeve 346 at the intermediate section 326 blocks vibrations by itself, and in combination with the ring 382 within the end plug 368 , the sleeve 346 and the ring 382 interact to create a larger sweet spot along the length of the barrel 324 . The sleeve 346 and the ring 382 , disposed at opposite ends 334 , 366 of the barrel 324 , cooperate to contain vibrations that occur when a ball hits the bat 320 as well as channel those vibrations in order to increase the volume of a desirable “ping” sound that occurs from the ball hitting the bat 320 . The ring 382 is made of a 65 D polyurethane material that allows a softer durometer material to be used in the end plug 368 .
[0080] An example of several methods of manufacturing the bat 20 , 120 , 220 , 320 of the present invention will now be described. It is to be understood that the methods used may be altered in some respects while still creating a bat 20 , 120 , 220 , 320 having the desired characteristics. Also, certain dimensions, materials, temperatures, etc. may be altered depending upon the size, weight and intended use of the resulting bat 20 , 120 , 220 , 320 . The connection between the handle 22 , 122 , 222 , 322 and barrel portions 24 , 124 , 224 , 324 allows the balance between the handle 22 , 122 , 222 , 322 and barrel portions 24 , 124 , 224 , 324 to be adjusted so that the majority of the weight of the bat 20 , 120 , 220 , 320 is at the intermediate section 26 , 126 , 226 , 326 . The position of the intermediate section 26 , 126 , 226 , 326 along the length of the bat 20 , 120 , 220 , 320 may be adjusted as well as the length and/or thickness of the intermediate section 26 , 126 , 226 , 326 . In general, the barrel portion 24 , 124 , 224 , 324 has a minimum thickness of 0.070 inches and a maximum thickness of 0.115 inches. The thickness of the connection area of the bat 20 , 120 , 220 , 320 is determined by the weight/size of the bat 20 , 120 , 220 , 320 .
[0081] The composite material handle portions 22 , 122 , 222 , 322 may be manufactured using a variety of techniques. These techniques include, but are not limited to: resin transfer molding (RTM); vacuum resin transfer molding (VRTM); filament winding and wrapping technique. Using RTM, various layers of the composite material are pre-manufactured to from the handle portion 22 , 122 , 222 , 322 . Wrapping technique provides a layer-by-layer formation of the handle portion 22 , 122 , 222 , 322 that allows the manufacturer to control the flexibility of the handle portion 22 , 122 , 222 , 322 . In general, the handle portion 22 , 122 , 222 , 322 is formed by approximately sixteen to twenty layers of composite material, depending on fiber type, fiber thickness (0.001-0.003 inches), fiber area weight (FAW) and flex.
[0082] A metal tube, such as an aluminum alloy tube, is provided at predetermined lengths and weights prior to manufacturing. For purposes of the following example, an aluminum alloy tube is provided for the manufacture of the barrel portion 24 , 124 , 224 , 324 for the bat 20 , 120 , 220 , 320 .
[0083] The metal tube is first thermally treated. This is often referred to in the art as an annealing process. The thermal treatment softens the metal by removing the stress resulting from cold working. This process is to be repeated after a certain amount of cold work has been performed on the metal tubes. Before each cold forming process, the temperature of an anneal oven is set at four hundred ten degrees Centigrade. The aluminum tube is heated in the oven at this temperature for approximately three hours. The oven temperature is then decreased by twenty degrees Centigrade per hour, after the three hour soak time, until the temperature of the tubes has reached twenty degrees Centigrade. The aluminum tube is then heated at a temperature of two hundred thirty degrees Centigrade for two hours, at which point the oven temperature is reset to one hundred forty degrees Centigrade. The tube is removed from the oven when the temperature of the oven has reached one hundred forty degrees Centigrade.
[0084] The tube is then cleaned. During the annealing process, an oxidation scale develops on the surface of the aluminum tube. An acid cleaning process is required to remove the oxidation scale. The tube is soaked in a sulfuric acid solution for approximately thirty minutes to remove the oxidation scale each time the tube is annealed.
[0085] The tube is then formed into the barrel portion 24 , 124 , 224 , 324 of desired thickness, contour and length. This wall forming process is a cold working process. It is performed to obtain a wall of a desired thickness. Several cold forming passes may have to be performed depending upon several factors including metal type and the type of bat 20 , 120 , 220 , 320 desired. In the instant example, the tube forming the aluminum barrel portion 24 , 124 , 224 , 324 is subject to the cold working process on the outside diameter and the wall thickness simultaneously to obtain a wall thickness ranging from the minimum thickness of 0.070 inches to the maximum thickness of 0.115 inches. The barrel portion 24 , 124 , 224 , 324 is then cleaned. A degreasing process is required to remove all lubricants and residue substances out of the aluminum barrel portion 24 , 124 , 224 , 324 . This is performed using an ultrasonic method with a detergent agent before and after the aluminum tube is annealed.
[0086] The barrel portion 24 , 124 , 224 , 324 is then cut, trimmed and swaged to a desired length and contour. A thin end of the aluminum barrel portion 24 , 124 , 224 , 324 is trimmed to a predetermined length. It is important to have the thin ends of the aluminum barrel portions 24 , 124 , 224 , 324 squarely trimmed to avoid folding problems when the tubes are swaged by a rotary taper swager. The aluminum barrel portion 24 , 124 , 224 , 324 is swaged with a rotary swaging machine to obtain the desired contour shape and wall thickness. In the instant example, the required wall thickness after swaging is generally a minimum thickness of 0.070 inches and a maximum thickness of 0.115 inches for the barrel portion 24 , 124 , 224 , 324 .
[0087] The tapered sleeve 46 , 146 , 246 , 346 may be formed using conventional methods which may vary. The tapered sleeve 46 , 146 , 246 , 346 is shaped to obtain a desired contoured shape that will later assist in giving the exterior surface of the bat 20 , 120 , 220 , 320 a generally continuous appearance. After forming the rigid sleeve 46 , 146 , 246 , 346 , the handle portion 22 , 122 , 222 , 322 can be molded with the sleeve 46 , 146 , 246 , 346 .
[0088] If necessary, after shaping, the barrel portion 24 , 124 , 224 , 324 is cut to the desired length.
[0089] The barrel portion 24 , 124 , 224 , 324 is then thermally treated, quenched and aged in order to obtain a T6/T7 Temper. It is commonly known in the art to expose metal or alloys to a heating and cooling treatment to obtain desired conditions, properties and an increase in strength. The barrel portion 24 , 124 , 224 , 324 is heat treated to obtain the highest tensile and yield strengths. The required temperature and time for the solution heat treatment is twenty-seven minutes at a temperature of four hundred eighty degrees Centigrade. After the barrel portion 24 , 124 , 224 , 324 is heat treated, they are quenched immediately with either air or water. Quenching is a controlled rapid cooling of a metal from an elevated temperature by contact with a liquid, gas or solid. Precipitation from solid solution results in a change in properties of the alloy, usually occurring rapidly at elevated temperatures. The barrel portion 24 , 124 , 224 , 324 is aged in an oven for twelve hours at one hundred thirty five degrees Centigrade.
[0090] After aging, the tapered ends 34 , 134 , 234 , 334 of the barrel portion 24 , 124 , 224 , 324 are contoured by machining. The respective threads 142 and corrugations 242 of the barrel portions 124 , 224 are machined to obtain the desired configuration and dimensions to closely receive the respective threads 140 , corrugations 242 and other parts of the handle portions 122 , 222 . The end 34 , 134 , 234 , 324 of the barrel portion 24 , 124 , 224 , 324 is machined to achieve squareness and an angled exterior surface in order to obtain a snug mating with the handle portion 22 , 122 , 222 , 322 .
[0091] The barrel portion 24 , 124 , 224 , 324 is then cleaned again. Due to the treatments, the barrel portions 24 , 124 , 224 , 324 oxidizes. This oxidation is removed by an anodizing process. The barrel portion 24 , 124 , 224 , 324 is anodized for five minutes. To eliminate all possible contaminations, the surface of the barrel portion 24 , 124 , 224 , 324 is then thoroughly cleaned with methyl ethyl ketone.
[0092] At this point, the barrel portion 24 , 124 , 224 , 324 is assembled as outlined above, with respect to FIGS. 1-19 .
[0093] Thereafter, approximately a one half inch portion of the open barreled end 64 , 164 , 264 , 366 is rolled inward at a ninety degree angle to accommodate the end plug 66 , 166 , 266 , 368 . If necessary, the protruded portion of the rolled portion is machined to achieve an opening of one and a quarter inches in diameter for installing the end plug 66 , 166 , 266 , 368 . The keyholes/slots 74 , 174 , 274 , 376 are then machined into the lip 70 , 170 , 270 , 372 and interior of the barrel portion 24 , 124 , 224 , 324 .
[0094] The bat 20 , 120 , 220 , 320 is then polished and decorated. Any appropriate methods of polishing and decoration, as are well known in the art, can be applied. In the preferred embodiment, the outer surfaces of the barrel portion 24 , 124 , 224 , 324 are exposed to sodium hydroxide to strip an anodize coating created during the manufacturing process as well as to prepare the outer surface for anodic coating process. Typically, the concentration of the sodium hydroxide is fifty grams per liter. The outer surface of the barrel portion 24 , 124 , 224 , 324 is mechanically polished to obtain a mirror finish. The external surface of the barrel portion 24 , 124 , 224 , 324 is then anodized. In the alternative, the external surface of the barrel portion 24 , 124 , 224 , 324 may be painted, chromed, powder-coated, or covered by some other method of decorative coating. The outer surface of the barrel portion 24 , 124 , 224 , 324 may be decorated with a graphic by using various methods such as silkscreening, heat transferring, or pad stamping. The handle portion 22 , 122 , 222 , 322 may also be decorated using same/similar techniques.
[0095] The bat 20 , 120 , 220 , 320 is completed by attaching the knob 28 , 128 , 228 , 328 typically by gluing the knob 28 , 128 , 228 , 328 to an open end of the handle portion 22 , 122 , 222 , 322 opposite the tapered end 32 , 132 , 232 , 332 . The grip 30 , 130 , 230 , 330 and the end plug 66 , 166 , 266 , 368 are also installed to finish the bat 20 , 120 , 220 , 320 .
[0096] In the alternative, the above described method of manufacturing the bat 20 , 120 , 220 , 320 may be varied. For example, physical characteristics of the bat 20 , 120 , 220 , 320 such as the length, wall thickness or diameter may be increased or decreased.
[0097] An important feature of the bat 20 , 120 , 220 , 320 is the balance of the bat 20 , 120 , 220 , 320 . The balance of the bat affects a user's control of the bat 20 , 120 , 220 , 320 . The length L, thickness t and position P of the intermediate section 26 , 126 , 226 , 326 of the bat 20 , 120 , 220 , 320 affects the balance of the bat 20 , 120 , 220 , 320 , as seen in FIGS. 4 , 6 , 8 and 16 , respectively.
[0098] Although constructed from affordable medium to high strength, light weight, and commercially available materials, the bat 20 , 120 , 220 , 320 of the present invention offers the performance and advantages of expensive and high strength materials. The bat 20 , 120 , 220 , 320 also dampens the vibrations created when traditional metal bats hit the ball that would otherwise sting the hitter's hand when a bat contacts a ball. Premature longitudinal cracking of the barrel portion 24 , 124 , 224 , 324 caused in traditional bats with thin wall thicknesses and high stress conditions, is avoided in the present invention.
[0099] The above-described embodiments of the present invention are illustrative only and not limiting. It will thus be apparent to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. Therefore, the appended claims encompass all such changes and modifications as falling within the true spirit and scope of this invention.
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Assembling a multi-component baseball bat includes disposing a rigid sleeve coaxially over a portion of an elongate composite handle. The rigid sleeve encircles a second end of the handle and extends toward a first end of the handle. A ring is positioned near a second end of a bat barrel. A first end of the bat barrel is inserted into the second end of the handle; the first end of the bat barrel being secured within the second end of the handle. An illustrative bat includes an elongate composite handle and an elongate barrel, each having opposite first and second ends. The first end of the barrel is disposed within the second end of handle. A mechanism secures the first end of the barrel within the second end of the handle. A rigid sleeve encircles the second end of the handle, extending towards the first end thereof.
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CROSS REFERENCE TO RELATED APPLICATION
Cross-reference is made to the following U.S. patent application Ser. Nos. 12/338,058, entitled “Region-Matching Transducers For Natural Language Processing” and 12/338,029, entitled “Complex Queries For Corpus Indexing And Search” that (a) are concurrently filed herewith, (b) are assigned to the same assignee as the present invention, and (c) are incorporated in this patent application by reference.
BACKGROUND
The following relates generally to methods, apparatus and articles of manufacture therefor, for defining finite-state networks for marking, tagging, characterizing, or indexing input data recognized by the networks as intelligible natural language data. Such marked data may subsequently be further processed using natural language applications, such as categorization, language identification, and search. In one embodiment, the finite-state marking networks are applied to corrupted language data to mark intelligible language data therein. Text-based errors may be introduced in language data, for example, when image-based documents or audio-based files are processed to identify characters or words therein using, for example, OCR (optical character recognition) or voice-to-text applications. Text-based errors may arise from character recognition errors that introduce misspellings that render a word or sentence that it forms part of unintelligible. Such errors hamper subsequent language processing search or analysis of the textual data using natural language processing applications.
Once a corpus is processed using finite-state natural language technology the data may be indexed for the purpose of querying information in the corpus. An index is generally a data structure that may be used to optimize the querying of information, by for example, indexing the location of key terms found in a corpus. Queries may be simple or complex. For example, a simple query may be used to search for the presence of two terms in a corpus, while a complex query used for example in a Database Management System (DBMS) may be defined using a specialized language called a query language. Generally, facilities for creating indices and queries are usually developed separately, and have different properties.
DESCRIPTION OF RELATED ART
Palo Alto Research Center (PARC) has developed and commercialized natural language technology that has been used in various natural language applications, as described in “PARC Natural Language Processing”, Media Backgrounder, March 2007. One such technology enables finite-state machines to form linguistic descriptions that may be used in applications that include spell checking, identifying and classifying named entities, OCR language modeling, and information extraction. Basic language processing, such as tokenization, morphological analysis, disambiguation, named-entity recognition, and shallow parsing, may be performed with such PARC finite-state natural language technology.
Further, such PARC finite-state natural language technology includes authoring and compiler tools for creating finite-state networks, such as automata and transducers, as well as, runtime tools for applying such networks to textual data. Finite-state networks may be compiled from different sources, including word lists and regular expressions, a formal language for representing sets and relations. A relation is a set of ordered string pairs, where a string is a concatenation of zero or more symbols. Further, calculus operations may be performed on networks, including concatenation, union, intersection, and composition operations, and the resulting networks may be determinized, minimized, and optimized.
For example, such PARC finite-state technology may be used to apply finite-state networks to strings. For example, a network that is a lexical transducer for English may be used to analyze inflected and lexical forms of words (e.g., the inflected form “leaves” may produce the lexical forms “leave+Verb+Pres+3sg”, “leave+Noun,+Pl”, and “leaf+Noun+Pl” and the lexical form “leave+Noun+Pl” may produce the inflected form “leaves”).
A. Finite-State Replacement Expressions
Finite-state replacement expressions include, for example, simple replacement operations (e.g., A→B) and marking operations (e.g., UPPER @→PREFIX . . . SUFFIX). Generally, definitions of finite-state replacement expressions and example uses are described in Chapters 2.4.2 and 3.5.5 of the publication by K. Beesley and L. Karttunen, entitled “Finite State Morphology”, CSLI publications, Palo Alto, Calif., 2003, which entire contents, including but not limited to Chapters 2.4.2 and 3.5.5, are incorporated herein by reference.
For example, technology for performing entity recognition is known, such as Inxight SmartDiscovery™ fact extraction software made available by Inxight Software, Inc. (see Inxight SmartDiscovery™ fact extraction Product Datasheet), which recognizes named entity types based on patterns in text. In addition, XLE (Xerox Linguistic Environment) software made available by PARC is adapted to perform shallow markup to identify named entities (see in addition R. Kaplan, and T. King, “Low-level mark-up and large-scale LFG grammar processing”, in Proceedings of the LFG03 Conference, CSLI On-line Publications, 2003).
A.1 Compile-Stage Replacement Methods
U.S. Pat. No. 6,023,760, which is incorporated herein by reference in its entirety, discloses in section D.3 methods for defining matching finite-state transducers for marking instances of a regular language using the simple replace operation (represented by the symbol “→”), which is non-deterministic, or using the directed replacement operations (such as the left-to-right, longest-match replace operator represented by the symbol “@→”), which are deterministic. For example, named entities may be marked in a regular language to appear as XML mark-up (e.g., <company>PARC</company>). Such named-entity XML markup may be introduced into textual content by applying thereto a pattern matching finite-state transducer (FST) that has been compiled into a network from a regular expression.
Additional background concerning the use of the replace operators is disclosed in the following publications: L. Karttunen entitled “The Replace Operator”, in Proceedings of the 33rd Annual Meeting of the Association for Computational Linguistics, ACL-94, Boston, Mass., pp. 16-23, 1995; L. Karttunen entitled “Directed Replacement”, in Proceedings of the 34th Annual Meeting on Association For Computational Linguistics, pp. 108-115, 1996; and L. Karttunen, J. Chanod, G. Grefenstette, and A. Schille, “Regular Expressions for Language Engineering”, Natural Language Engineering Vol. 2, Issue 4, pp. 305-328, 1996.
Directed replacement operations (such as the left-to-right, longest-match directed replacement operator represented by the symbol “@→”) function well in cases where the pattern being matched consists of a small number of elements. For example, patterns representing social security numbers may be represented with a lexicon that identifies eleven characters: three digits, a dash, two digits, a dash, and four digits, and patterns representing dates may be represented with a lexicon that identifies a month component, a day component, and a year component. However, the use of directed replacement operators with a lexicon to represent patterns that identify names, such as example definitions in Table 1, becomes computationally expensive with respect to the compilation time of the network and size of the network as the number of patterns defined by the lexicon increases.
In the example definitions in Table 1, “Name” is defined as consisting of either a first name or a last name preceded by an optional first name, where “space” is an optional whitespace character. The general form of the replacement expression in Table 1 is of the form “UPPER @→PREFIX . . . SUFFIX”, which when compiled produces a transducer that locates instances of UPPER in the input string under the left-to-right, longest-match regimen, but instead of replacing the matched strings, the transducer copies them, inserting the specified prefix and suffix. Accordingly, the “NameParser” transducer in Table 1 maps Lauri (FirstName) Karttunen (LastName) to <Name> Lauri Karttunen </Name>, following the left-to-right, longest-match principles of the directed replacement operator represented by the symbol “@→” and wthe special symbol “ . . . ”, which is used to mark the place around which insertions are to be made.
TABLE 1
define Name FirstName | (FirstName space) LastName;
define NameParser Name @-> “<Name>” ... “</Name>”;
A.2 Apply-Stage Replacement Method
In an alternate method, referred to herein as “the apply-stage replacement method” or “the pmatch method”, is adapted to scale with a large number of names. In the apply-stage replacement method, replacement operations are implemented when a finite-state network is applied to a string (i.e., during the apply stage, e.g., when a network is applied to an inflected form to produce a lexical form). This alternate method is more efficient to perform a longest-match replacement during the apply stage rather than hard-coding such constraints into a transducer for use with replacement operations using directed replacement operators, such as the left-to-right, longest-match replace operator (represented by the symbol “@→”) discussed above. In addition, the apply-stage replacement method marks a pattern only upon reaching the end of a matched pattern, and allows the same string to match more than one pattern. These efficiencies lead to a smaller network size that permits a matching network to scale with a large number of names or entities.
Table 2 set forth an example definition using the apply-stage replacement method. Similar to the example shown in Table 1, the example shown in Table 2 produces a transducer that maps Lauri Karttunen to <Name> Lauri Karttunen </Name>. However, unlike the left-to-right, longest-match principles of the directed replacement operator, the apply-stage replacement method operates according to the following principles: (a) a pattern starts from the beginning of a string or after a non-alphanumeric symbol (i.e., if no match is found after examination of a first symbol of a word, subsequent symbols are written without examination, together with the first symbol, to an output buffer); (b) the longest match is always attempted to be made and no search is ever started in the middle of another search (e.g., the preliminary result “Lauri” is ignored for the longer match “Lauri Karttunen”); and (c) upon reaching the final state, with one or more tag arcs following a match because of an epsilon (i.e., a symbol representing an empty string) on the input side and with the next input symbol satisfying a default ending condition, an initial tag is inserted into the output buffer followed by a copy of the matching string and a closing tag.
TABLE 2
define Name FirstName | (FirstName space) LastName;
define NameParser Name </Name>:0;
Table 3 sets forth an example illustrating additional features of the apply-stage replacement method. In the example in Table 3, the resulting Names network that consists of a linear path for the string “Sara Lee”, leading to the penultimate state with two arcs, one labeled “</Company> and the other “</Person>”, is adapted to recognize all instances of Sara Lee (e.g., whether as a person or a company). Advantageously, the Names network combines several patterns into a single network that may be used to match in parallel.
TABLE 3
define CTag “</Company>”:0;
define PTag “</Person>”:0;
define Persons {Sara Lee};
define Companies {Sara Lee};
define Names Companies CTag | Persons PTag;
More specifically, when the Names network defined in Table 3 is applied to the input string “He works for Sara Lee.”, the apply-stage replacement method starts at the beginning of the input string and at the start state of the Names network by trying to match the first symbol “H” of the input against the arcs of the current pattern state. If it finds a match, it advances to the arc's destination state and to the next symbol in the input string. If it fails to find a match, as the case is here, it writes the “H” into an output buffer and advances to the next symbol, “e”. Before starting the matching process, the left context at its current position is checked. The default requirement is that a pattern should start from the beginning of a string or after a non-alphanumeric symbol. Because the “e” and the following space do not meet the starting condition, they are appended to the output buffer without any attempt to match them. With this input string, the matching attempts fail until the process reaches the letter “S”. From there on, the input matches the path leading to the penultimate state of the Names network. At that point, the end of the input string has been reached but both of the tag arcs yield matches because they have an epsilon on the input side. Having reached a final state over a tag arc with no input left to check, the default ending condition is determined to be satisfied since the next symbol of the input string is a period.
Upon satisfying the default ending condition, the apply-stage replacement method reads off the tag on the output side of the label, creates the corresponding initial XML tag and inserts it into the output buffer. Depending on the order of the tag arcs in the penultimate state, the start tag is either <Company> or <Person>. Assuming <Company> is the start tag, the method continues by inserting the start tag into the output buffer and copies the matching string into the output buffer followed by the closing tag. At this point the output buffer contains the string “He works for <Company>Sara Lee</Company>”. In processing the second tag (i.e., <Person>), the method takes note of the fact that it has already performed one analysis for the string and wraps the second pair of initial and closing tags around the first pair. The final output of the method is “He works for <Person><Company>Sara Lee</Company></Person>.”.
Assuming, by way of a further example of the apply-stage replacement method, “Sara” and “Lee” are added to the “Persons” list in Table 3. Given the same input string as the preceding example, a successful match occurs at the point where the output buffer contains the string “He works for <Person>Sara</Person>”. Even though the method detects that a final state of the Pattern network has an outgoing arc due to a space symbol, the method ignores this preliminary result and attempts to make a longer match because the method always looks for the longest match. At the point when the method comes to the <Company> and <Person> tags, the preliminary output gets overwritten and the final output is similar to the preceding example. Because the method never starts a search in the middle of another search, it will not try to find a match for “Lee” in this case. Consequently, this method passes over strings that are substrings of a successfully matched longer string.
Depending on the desired output format, the apply-stage replacement method operates according to one or more of the output modes set forth in Table 4. The output modes may be controlled, for example, using interface variables, with each variable having a default value.
TABLE 4
Mark-patterns : Wrap XML tags around the strings that match a
pattern, for example, <Actor>Grace Kelly</Actor>.
Locate-patterns : Leave the original text unmodified. Produce an
output file that indicates for each match its beginning byte position in
the file, length of text, text, and XML tag, for example, 78|11|Grace
Kelly|<Actor>.
Extract-patterns : Extract from the file all the strings that match
some pattern. Output them with their tags. For example,
<Actor>Grace Kelly</Actor>. Ignore all the rest.
Redact-patterns: Ignore strings that match some pattern. Output
the rest.
B. Syntactic Analysis
Replacement expressions have been used to perform syntactic analysis. For example, as disclosed in Chapter 3.5.5 of the publication by K. Beesley and L. Karttunen, entitled “Finite State Morphology”, CSLI publications, Palo Alto, Calif., 2003, under the section entitled “Bracketing or Markup Rules”, longest-match operators may be used for bracketing noun phrases in text, after a sentence has already been morphologically analyzed and reduced to part-of-speech tags. One way to characterize English noun phrases is to start with an optional determiner (Det), followed by any number of adjectives Adj*, and end with one or more nouns Noun+, which may be represented using the following regular expression: (Det) Adj*Noun+.
In addition, the publication by A. Shiller, entitled “Multilingual Finite-State Noun Phrase Extraction”, in Proceedings of the ECAI 96 Workshop, 1996, describes using finite-state technology for marking and labeling noun phrases. As set forth in Section 5 of the publication, a noun phrase markup transducer may be applied to tagged text (i.e., after tokenization and part-of-speech disambiguation is performed on the text) to insert brackets around and label the longest matching noun phrase patterns in the text.
C. Beyond Keyword Searching
For certain classes of document collections, keyword searching is not sufficient on its own to provide access to relevant documents in such collections. Keyword searching may not function well, for example, when a document collection: consists of many different genres of documents (e.g., email versus a memo), suffers from different kinds of errors (e.g., poor OCR quality versus poor categorization), and supports different types of users (e.g., an engineering organization versus a marketing organization). Solutions for improved keyword searching include term-based indices and query languages. Term-based indices provide rapid access to document content in a collection. Query languages enable greater search precision beyond keyword searching with operations between keywords (e.g., AND and OR operations) and with operators that act on searches (e.g., NEAR, which enables the notion of proximity or NEXT, which enables the notion of keyword order).
SUMMARY OF BACKGROUND
Accordingly, there continues to be a need for systems and methods for pre-processing text-based document collections that originate from image-based or audio-based data in-advance of further linguistic-based document processing. Further, there continues to be a need for systems and methods for improved pattern matching finite-state technology for use with categorization methods (e.g., topic, language identification, etc.).
In addition, there continues to be a need for systems that improve searching heterogeneous document collections with automated term-based indexing. More specifically, there continues to be a need for improved systems and methods that integrate the development of database indices together with complex query generation to simplify query formation and search.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the disclosure will become apparent from the following description read in conjunction with the accompanying drawings wherein the same reference numerals have been applied to like parts and in which:
FIG. 1 illustrates a general purpose computer for carrying out embodiments;
FIG. 2 illustrates a language processing system that may operate on the general purpose computer shown in FIG. 1 ;
FIGS. 3 and 4 are flow diagrams for developing a region matching transducer for marking identified patterns in language data;
FIG. 5 illustrates an example morphological transducer;
FIG. 6 illustrates an example POS class-matching network;
FIG. 7 illustrates an example APP class-matching network;
FIG. 8 illustrates an example region-matching regular expression;
FIG. 9 illustrates an example region-matching transducer;
FIG. 10 illustrates example language data and example output after applying the “Slogan” region-matching transducer shown in FIG. 8 ;
FIG. 11 illustrates an example regular expression;
FIGS. 12 , 13 , and 14 illustrate example region-matching transducers;
FIGS. 15 and 16 illustrate an example upper-parse table and an example lower-parse table, respectively;
FIG. 17 illustrates an exemplary method for text-characterization;
FIG. 18 illustrates an example region-matching transducer for use with language identification;
FIG. 19 sets forth a method for facilitating the search for content in a document collection by automating indexing of complex query-patterns within a document collection;
FIG. 20 illustrates an example complex query pattern;
FIG. 21 illustrates complex query development;
FIG. 22 illustrates indexing a corpus using a complex query;
FIG. 23 illustrates an example complex query in the form of a regular expression;
FIG. 24 illustrates the regular expression shown in FIG. 23 compiled as a region-matching transducer;
FIG. 25 illustrates example corpus data with positional information added identifying the start of each sentence;
FIG. 26 illustrates example extracted postings;
FIG. 27 illustrates the example postings shown in FIG. 26 after being sorted and consolidated;
FIG. 28 illustrates a query engine for receiving queries with query tags;
FIG. 29 illustrates an example query using an query tag;
FIG. 30 illustrates example search results after performing the search using the query shown in FIG. 29 on the corpus shown in FIG. 25 using the corpus index shown in FIG. 27 .
DETAILED DESCRIPTION
A. Conventions and Definitions
Finite-state automata are considered to be networks, or directed graphs that are represented in the figures using directed graphs that consist of states and labeled arcs. The finite-state networks may contain one or more initial states, also called start states, and one or more final states. In the figures, states are represented as circles and arcs are represented as arrows. Also in the figures, the start states are represented as the leftmost states and final states are marked by a double circle.
Each state in a finite-state network acts as the origin for zero or more arcs leading to some destination state. A sequence of arcs leading from the initial state to a final state is called a “path”. A “subpath” is a sequence of arcs that does not necessarily begin at the initial state or end at a final state. An arc may be labeled either by a single symbol such as “a” or a symbol pair such as “a:b” (i.e., two-sided symbol), where “a” designates the symbol on the upper side of the arc and “b” the symbol on the lower side. If all the arcs are labeled by a single symbol, the network is a single-tape automaton; if at least one label is a symbol pair, the network is a transducer or a two-tape automaton; and more generally, if the arcs are labeled by “n” symbols, the network is an n-tape automaton.
Arcs of finite-state networks may include “Flag Diacritics”, which are special symbols of the form @X.Y.Z@ or @X.Y@ where “X” represents some action that the FST Engine 144 should take when it encounters the symbol when applying a network with a Flag Diacritic to a string, “Y” represents a feature, and “Z” a value. One type of action “X” is the action “insert flags” represented by “I”. For example, applying the Flag Diacritic @I.Det@ in an original network, involves processing the input in the “Det” network and resume the process in the original network once a final state in the Det network has been reached.
A Flag Diacritic can be compiled out of a network by splicing in the network to which the Flag Diacritic refers. For example, an insert flag such as @I.Det@ may be removed from a network by splicing in the Det network for each arc in the network with @I.Det@ label. A network with Flag Diacritics or with its Flag Diacritics compiled out produces equivalent output. However, the relative size of the network with Flag Diacritics will be smaller depending on the number of times a Flag Diacritic repeats and the size of the network that is spliced in for the Flag Diacritic. Additional information concerning Flag diacritics is described in Chapter 7 of the publication by K. Beesley and L. Karttunen, entitled “Finite State Morphology”, CSLI publications, Palo Alto, Calif., 2003.
Further background on finite-state technology is set forth in the following references, which are incorporated herein by reference: Lauri Karttunen, “Finite-State Technology”, Chapter 18, The Oxford Handbook of Computational Linguistics, Edited By Ruslan Mitkov, Oxford University Press, 2003; Kenneth R. Beesley and Lauri Karttunen, “Finite State Morphology”, CSLI Publications, Palo Alto, Calif., 2003; Lauri Karttunen, “The Replace Operator”, Proceedings of the 33rd Annual Meeting of the Association for Computational Linguistics, Boston, Mass., pp. 16-23, 1995; U.S. Pat. No. 6,023,760, entitled “Modifying An Input String Partitioned In Accordance With Directionality And Length Constraints”.
The table that follows sets forth definitions of terminology used throughout the specification, including the claims and the figures. Other terms are explained at their first occurrence.
Term
Definition
String, Language,
A string is concatenation of symbols that may, for example,
and Relation
define a word or a phrase, or a portion thereof. The symbols
may encode, for example, alphanumeric characters (e.g.,
alphabetic letters), music notes, chemical formulations,
biological formulations, and kanji characters (e.g., which
symbols in one embodiment may be encoded using the
Unicode character set). A language refers to a set of strings. A
relation refers to a set of ordered pairs, such as {<a,bb>, <cd,ε>}.
Entity
A collection of alphanumeric symbols that have an understood
or assigned meaning, such as a word or phrase. Examples of
entities include but are not limited to people, companies, and
dates.
Document
A collection of electronic data that may include one or a
combination of text, images, and graphics. Entities may form all
or part of the content of a document using one or more of a
combination of text, images, and graphics. Such document
content may be rendered on hardcopy representations (e.g.,
paper) or softcopy representations (e.g., electronic display) that
may be viewed or touched (e.g., as Braille on a hardcopy
representation). Alternatively, such document content may be
rendered into an audio representation for listening. In addition,
such representations may be electronically recorded (e.g.,
using a recording device such as a camera, a scanner, and
microphone) for further processing and subsequently re-
rendered.
XML
EXtensible Markup Language
<xxx> </xxx>
an XML tag that defines the start and end of an item labeled
“xxx”, respectively
Union
Constructs a regular language that includes all the strings of
Operator “|”
the component languages. For example, “a|b” denotes the
language that contains the strings “a” and “b”, but not “ab”.
“Define”
The variable “v” may be defined as the language of the
Function
possible values. For example, “define color [blue|green|red|
white|yellow]”, defines the language “color” with the possible
values blue, green, red, white, and yellow.
A -> B
Replacement of the language A by the language B. This
denotes a relation that consists of pairs of strings that are
identical except that every instance of A in the upper-side string
corresponds to an instance of B in the lower-side string. For
example, [a -> b] pairs “b” with “b” (no change) and “aba” with
“bbb” (replacing both “a”s by “b”s).
A @-> B
Left-to-right, longest match replacement of the language A by
the language B. Similar to [A -> B] except that the instances of
A in the upper-side string are replaced selectively, starting from
the left, choosing the longest candidate string at each point.
ε (i.e., epsilon)
Denotes the symbol for an empty string.
@I.Y@
Denotes a Flag Diacritic that may appear on an arc of a first
network, where “I” identifies the insert Flag Diacritic and “Y”
refers to a second network without having to repeat it.
B. Operating Environment
FIG. 1 illustrates a general purpose computer 110 for carrying out embodiments. The general purpose computer 110 includes hardware 112 and software 114 . The hardware 112 includes but is not limited to a processor (i.e., CPU) 116 , memory 118 (ROM, RAM, etc.), persistent storage 120 (e.g., CD-ROM, hard drive, floppy drive, tape drive, etc.), user I/O 122 , and network I/O 124 . The user I/O 122 may include a keyboard 126 , a pointing device 128 (e.g., pointing stick, mouse, etc.), a recording device 129 , and an output device (e.g., display, printer, etc.) 130 . The network I/O 124 may for example be coupled to a network 132 such as the Internet.
The software 114 of the general purpose computer 110 includes an operating system 136 , FST network developer 140 , a regular expression compiler 142 , an FST engine 144 , and a query engine 148 . The operating system 136 enables a user of the general purpose computer 110 to compose finite-state networks using the FST network developer 140 and develop queries using query engine 136 , as more fully described below.
C. Pattern Matching Networks Development
FIG. 2 illustrates a language processing system 200 that may operate on the general purpose computer shown in FIG. 1 . The language processing system 200 includes the regular expression compiler 142 for developing region matching transducers 220 from region-matching regular expressions 218 that may subsequently be applied to input data, such as natural language data, using the FST engine 144 to produce tagged and/or indexed input data 224 and to populate data parse tables 226 . In addition, the FST engine 144 may include or be coupled to different language processing applications, such as categorization, language identification, and search, for using the tagged and/or indexed input data 224 and the populated data parse tables 226 , as further described herein.
FIGS. 3 and 4 are flow diagrams for developing a region matching transducer for marking identified patterns in input data, such as language data. At 302 , language data having delimited strings is recorded in a memory (such as memory 118 ). For example, delimited strings forming part of language data 222 (or more generally input data) may include words separated by spaces, as illustrated by the example language data set forth in FIG. 10 .
At 304 , one or more region matching transducers 220 are recorded in a memory, such as the memory 118 , that define one or more patterns of one or more sequences of delimited strings. At least one of the patterns in the region matching transducers 220 defines an arrangement of a plurality of class-matching networks 212 . For example, a plurality of class-matching networks 212 , defining a region matching transducer 220 , may be arranged to match a pattern of words that define a noun phrase produced with the union of two class-matching networks 212 . More generally, a region-matching transducer 220 may be produced using one or a combination of class-matching networks 212 from one or both of POS-class (e.g., noun, verb, adjective, pronoun, etc.) matching networks 214 and AAP (i.e., application-specific or non-linguistic terminology or concepts, e.g., company names, product names, etc.) class-matching networks 216 .
The region-matching transducers 220 recorded in the memory 118 have for each of the one or more patterns defined in the class-matching networks 220 , an arc that leads from a penultimate state with a transition label that identifies the entity class of the pattern, as shown for example in the network in FIG. 6 with the transition label “</NOUN>”. In addition, the region-matching transducer 220 recorded in the memory 119 shares states between patterns leading to a penultimate state when segments of strings making up two or more patterns overlap, as shown for example in the network in FIG. 6 which shares the base word “camel” for the words “camel” and “camels”. One embodiment for producing a region-matching transducer 220 is set forth in the flow diagram shown in FIG. 4 .
At 402 in FIG. 4 , POS (Parts-Of-Speech) class-matching networks 214 , a first type of class-matching network 212 , are produced. The POS class-matching networks (or network) 214 are networks that identify parts-of-speech such as nouns, verbs, adjectives, pronouns, etc. In one embodiment, the POS class-matching networks 214 , may be produced using format converter 211 which includes FST network developer 140 and a morphological transducer 210 . The format converter 211 converts a morphological lexicon, which may be represented as a morphological transducer, into a format expected by the FST engine, which implements the apply-stage replacement method. In one embodiment, the morphological transducer may be converted using command scripts that delete, move, and/or introduce tags as desired. A morphological transducer that implements a language, such as English, may include a plurality of morphological tags, such as, “+Sg” (i.e., singular), “+Pl” (i.e., plural), “+Pres” (i.e., present), “+PastPart” (i.e., past participle), etc. for morphologically analyzing natural language. Morphological analysis is the process which takes the surface form of a word and returns its lemma (i.e., the normalized form of a word that may be found in a dictionary), together with a list of morphological features and parts of speech. A morphological transducer is bi-directional and can be used to generate either surface forms (e.g., cat or cats) from their lexical form (e.g., cats is the plural form of the lemma cat), or a surface form from a lexical description (e.g., the plural form of cat is cats). For example, in the morphological transducer shown in 5 , surface forms appear on the lower side of the arcs and morphological tags together with the canonical form appear on the upper side of the arcs. Following the two different paths one ends up with either the singular (represented by tag +Sg) form (with no s at the end—represented using the epsilon symbol) or the plural (represented by tag +Pl) form of the noun (represented by tag +Noun) camel (with an s at the end).
Given a morphological transducer 210 , such as the morphological transducer shown in FIG. 5 , the FST network developer 140 eliminates all but basic POS (or morphological) tags, as detailed morphological analysis is less important for semantic indexing than parsing. When eliminated POS tags are paired with other than an epsilon (e.g., the plural POS tag being paired with the character “s”), the eliminated POS tag is substituted for an epsilon symbol so that those inflected forms (e.g., “camels”) produce the appropriate lemma (e.g., “camel”). The POS tags that are not eliminated are converted to a closing XML tag format. For example in converting the morphological transducer shown in FIG. 5 to the POS class-matching network 214 shown in FIG. 6 , the FST network developer 140 eliminates the POS tags for singular (i.e., +Sg) and plural (i.e., +Pl) and converts the basic POS tag for noun (i.e., +Noun) into the closing XML tag format (e.g., </NOUN>). In addition, the basic POS tag converted to the closing XML tag format is arranged to appear at the end of the POS class-matching network 214 , as shown in the example network in FIG. 6 .
At 404 in FIG. 4 , APP (APPlication specific) class-matching networks 216 , a second type of class-matching networks 212 , are produced. The APP class-matching networks 216 may be used separately or to augment the POS class-matching networks 214 with application-specific patterns that in different embodiments may be used to identify non-linguistic terminology and non-linguistic concepts, which may in turn be augmented to develop more complex patterns with different levels of granularity that may be required or be optional elements of the patterns. By way of example, the POS class-matching networks 214 shown in FIG. 6 , may be used to identify non-linguistic concepts, such as, companies, products, places, and people as shown by the APP class-matching network 216 in FIG. 7 , which identifies “camel” or “camels” with the label “cigarette”. More generally, the APP class-matching network 216 , such as the network shown in FIG. 7 , may be used to identify a non-linguistic concept such as “brands” (e.g., cigarette brands Camel, Kent, and Marlboro), which may be augmented with additional (optional or required) non-linguistic concepts such as “type” (e.g., cigarette types “light”, “extra-light”, and “low-tar”).
At 406 , a region-matching regular expression 218 is defined using one or more class-matching networks 212 (which were produced at 402 and 404 ), for identifying one or more patterns of delimited strings. An example region-matching regular expression 218 is shown in FIG. 8 that combines four auxiliary lexicons into a single pattern for identifying noun phrases, identified by “Slogan”. The four auxiliary lexicons include lexicons for specifying different determiners (i.e., “Det”), white space (i.e., “WS”), adjectives (i.e., “Adj”), and nouns (i.e., “Noun”). Each auxiliary lexicon lists the different possibilities for each within its class, three of which specify a different part-of-speech class: determiner, adjective, and noun. For the white space auxiliary lexicon, white space may be specified using one or more or a combination of blank spaces and dashes, whereas determiners may be specified using the articles “the” and “a”. Example patterns that satisfy the regular expression “Slogan” defined in FIG. 8 include but are not limited to “the government”, “the federal government”, and “government agencies”, where each auxiliary lexicon is identified in the regular expression Slogan with an Insert Flag Diacritic.
At 408 in FIG. 4 , the region-matching regular expression 218 is compiled into a region-matching transducer 220 using, for example, the regular expression compiler 142 . FIG. 8 illustrates a regular expression “Slogan” that may be compiled into the region-matching transducer shown in FIG. 9 using the regular expression compiler 142 . As shown in FIG. 8 , the region-matching transducer includes an arc that leads from a penultimate state with the transition label “</NP>” that identifies the entity class noun phrase (i.e., NP) and states that are shared between patterns that lead to the penultimate state (e.g., “the fox” and “the brown fox”). Advantageously, the region-matching transducer 220 is determinized and minimized, thereby sharing similar structure. For example, assuming the string “General Mills” is tagged as both a “Person” and a “Company”, the path leading to each tag would be shared up until the closing XML tag (e.g., “</Person>” and “</Company>”).
Referring again to FIG. 3 , the region matching transducer 220 recorded in memory, at 304 , is applied, at 306 , to input data with an apply-stage replacement method. The input data, which may be corrupted, does not require pre-labeling before being applied to the region-matching transducer 220 . The apply-stage replacement method follows a longest match principle for identifying one or more patterns in the region-matching transducer 220 that match one or more sequences of delimited strings in the input data. At least one of the matching sequences of delimited strings satisfies at least one pattern in the region-matching transducer defined by an arrangement of a plurality of class-matching networks.
Advantageously, the region matching transducer 220 may be applied to input data in a single pass while matching one or more patterns to the same input string. In one embodiment, when a string in the input data matches more than one pattern defined in the region matching transducer 220 , then all matches are recorded together (e.g., <Person><Company>General Mills</Company></Person>). Alternatively, only one or a subset of all matching patterns may be recorded.
At 308 , the one or more sequences of delimited strings satisfying at least one pattern in the region-matching transducer defined by an arrangement of a plurality of class-matching networks may be submitted to an application for further linguistic analysis, which includes but is not limited to translation, categorization, language identification, indexing, and intelligible information identification. Alternatively, the one more sequences of delimited strings may be output to an output device such as a memory, a printer, or a display.
FIG. 10 illustrates example input data, as well as resulting output when that input data is applied to the region-matching transducer shown in FIG. 9 . For the output mode shown in the example in FIG. 10 , the noun phrase patterns “The quick brown fox” and “the lazy dogs” that are identified in the example input data are marked in the example output with an initial XML tag with a noun phrase label (i.e., “<NP>”) and an ending XML tag with a noun phrase label (i.e., “</NP>”). In an alternative output mode, each of the identified noun phrase patterns is output to a file that records all matches, which may include in the file for each match (a) a starting (e.g., byte) position, (b) the length of the match, (c) the matching tag (e.g., NP), and (d) the matching pattern. It will be appreciated that variations of these and other output modes, such as those set forth in Table 4 above, may be used to output matching patterns. For example, the output mode may be in a form adapted further processing, including further linguistic analysis (e.g., translation and categorization), or for output, including display and printing.
D Pattern Matching Network Applications
In this section, applications (in addition to the application for recognizing noun phrases shown in FIGS. 8-10 ) for the pattern matching networks developed in the preceding section are discussed.
D.1 Identifying Intelligible Information in Corrupted Input Data
In one application, a region matching transducer 220 is developed for recognizing regions of uncorrupted (i.e., intelligible) language, such as English. FIG. 11 illustrates an example regular expression for developing a region matching transducer for identifying regions of uncorrupted language. In FIG. 11 , four auxiliary lexicons are defined for (a) words that initially start a sentence (i.e., “Initial”), (b) elements that are used to signify a spacing between words such as white space or weak punctuation (i.e., “WS”), (c) words that span between the beginning and the end of a sentence (i.e., “Middle”), and (d) words that end a sentence together with strong or final punctuation (i.e., “Final”). These four auxiliary lexicons combined using the “English” regular expression are compiled into the region-matching transducer 220 illustrated in FIG. 12 , where each auxiliary lexicon is identified in the English regular expression with an Insert Flag Diacritic. The resulting transducer extracts from input data regions of two or more English words that start with a capital letter and end in a sentence-final punctuation. Advantageously, the extracted sections may be submitted to an application which performs deeper analysis (e.g., morphological analysis and part-of-speech disambiguation), thereby avoiding that application from having to spend time processing passages in the input data that would not likely yield results.
By way of example, the region-matching transducer 220 shown in FIG. 12 may be used in applications that require the review of a collection of heterogeneous documents (e.g., emails, publications, letters, etc.), with varying degrees of legibility (e.g., because of poor quality original documents and/or poor OCR accuracy), for relevant information. Advantageously, such a region matching transducer may be used for recognizing and indexing uncorrupted regions with intelligible value (i.e., regions in the heterogeneous documents that are of sufficient quality and substance for further application processing). Subsequently, these indexed regions of intelligible value may serve as the basis for further application processing, such as, classification, translation and indexing.
D.2 Identifying Text-Characterizations In Input Data
In another application, a region matching transducer 220 may be augmented to count identified patterns for performing text-characterization (e.g., categorization or classification) on input data, by for example, topic or language. For such applications, the region matching transducer 220 identifies a set of possible categories or classes for selected input data, such as natural language data, to which the region matching transducer is applied. Similar to pattern matching, text-characterization exploits the construct developed in FIG. 304(I) of a region-matching transducer 220 that specifies for each pattern an arc that leads from a penultimate state with a transition label that identifies the entity class or category of the pattern.
In pattern text-characterization applications, the transition label of the region-matching transducer 220 , which is used to identify the characteristics (e.g., entity class or category) of an entity pattern, may be augmented to output both (i) an XML tag as a mark that indicates recognition of the pattern and (ii) a count indicating how many times the pattern has been matched. The resulting count associated with each XML tag may subsequently be recorded and used in various ways to categorize or classify the content to which the region-matching transducer is applied, for example topic or language.
As illustrated in region-matching transducer shown FIG. 13 , the path of the region-matching transducer 220 that an input string (or language data) has to match leads to a special transition labeled with a pair of symbols: an epsilon on the input (or lower) side and a special label (“</English>”) on the output (or upper) side. In one embodiment of the FST engine 144 , the matching of an input string against the path in the region-matching transducer 220 is indirect. That is, the arcs of the transducer are not actually labeled by strings or characters but by integers.
An example of labeling indirection for the region-matching transducer shown in FIG. 13 is illustrated in FIGS. 14 , 15 , and 16 . FIG. 14 illustrates symbol actual-values of each arc shown in FIG. 13 replaced with integer indirection-values. In one embodiment, the integer indirection-values for ASCII character symbols such as “p” is given by the integer representing the symbol of the corresponding ASCII value of the character, namely 112 . In the case of multi-character labels such as “</English>” or multi-character symbols such as the number “217”, the corresponding integer indirection-value is determined when the label is first encountered, which indirection-value may be represented by some integer n that may vary between instances of the FST engine 144 but are always unique within each instance.
As shown in the exemplary embodiment in FIGS. 14 , 15 , and 16 , the association between integer indirection-values and symbol (or label) actual-values is maintained using hash tables, which allow the FST engine 144 to associate a symbol actual-value, such as “</English>”, with its integer indirection-value, such as integer-value “507”. In one embodiment of the data parse tables 226 shown in FIG. 2 , an UPPER_PARSE_TABLE may be used to map symbol actual-values of the transducer's upper language to integer indirection-values, and a LOWER_PARSE_TABLE may be used to map symbol actual-values of the transducer's lower language to integer indirection-values, examples of which are shown in FIGS. 15 and 16 , respectively. In addition as illustrated in FIG. 15 , each PARSE_TABLE includes a hash table that maps any symbol actual-value to the integer indirection-value that represents it and a LABLE_TABLE that maps any known integer indirection-value to the label actual-value it represents.
For example, the upper-language symbol “</ENGLISH>” is represented by the integer indirection-value “507” as shown in the UPPER_PARSE_TABLE in FIG. 15 . In operation, the UPPER_PARSE_TABLE is used to map the sequence of symbols “</E N G L I S H>” to the integer-value “507”, and the LABEL_TABLE is used to map the integer indirection-value “507” to a structure that has several fields. In one embodiment, the structure of the LABEL_TABLE records any number of fields including the ID field, the NAME field and the DATA field. The ID field records the integer indirection-value representing an arc label such as “507”. The NAME field records the unicode representation of a label actual-value, such as “</ENGLISH>”.
In pattern matching applications with text-characterization, the DATA field of the LABEL_TABLE shown in FIG. 15 records additional information associated with its label (e.g., “507” corresponding to “/ENGLISH”), which for example may include an integer that records the number of occurrences the path associated with the label is traversed (e.g., trigram “pre”) when a region-matching transducer is applied to input data. In one embodiment, the DATA field may be populated with the number of instances a pattern has been matched while performing the one or more of the output modes set forth in Table 4 of the apply-stage replacement method. When pattern counting is turned on and one of the output modes is selected, the closing pattern label, for example </NP>, may be used to keep a running count of how often the pattern is matched in selected language data. In an alternate output mode, only the count associated with each closing pattern is output.
In one application of text-characterization, a region-matching transducer 220 may be used by the FST engine 114 to identify the language (e.g., English, French, Spanish, etc.) of input language data 222 (e.g., a document). It is generally known in the art that a system for language identification does not require that it have knowledge of a language to identify it because the frequency of particular letters and letter combinations in input language data 222 has a particular distinguishable frequency for each language, which frequencies define each language's a characteristic signature.
In another application of text-characterization, a region-matching transducer 220 may be used by the FST engine 114 to classify or categorize input language data 222 by domain or topic area such as sports, technology, and fashion. In this embodiment, different domain or topic areas may be developed by collecting a set of words or expressions that describe each domain or topic area, and then determining n-gram frequency vectors representative of frequency profiles for the set of words or expression that describe each domain or topic area.
Generally, such text-characterization applications involve the computation of the n-gram-frequency for input data, such as a document, having an unknown language or class, for example, by counting the occurrence of n-grams defined in a region matching transducer that match input data to which the transducer is applied. Once computed, the n-gram-frequency for the document is compared with n-gram tables that each records the frequencies of n-grams for each possible language or class. The language or class of the document is identified as the language or class with an n-gram signature that most closely matches the n-gram signature of the document. The counts for n-grams (e.g., related to a language or a class) correspond to the frequency the corresponding n-grams occur in input data, where the n-grams may represent one or more n-gram classes (e.g., unigrams, bigrams, trigrams, etc.). For example, some n-gram language identification systems only rely on trigrams, some tri-grams of which are common in many languages (e.g., the trigram “pre” is one of the three hundred most common trigrams in the English language as well as a dozen other languages, while the trigram “suo” is one of the most frequent trigrams occurring in the Finnish language).
One exemplary method for text-characterization is set forth in FIG. 17 . At 1702 , an n-gram-frequency table is computed for those most common n-grams for each text-characterization of a selected set of text-characterizations (e.g., languages, topics, etc.). In one exemplary embodiment for language identification, n-gram-frequency for the three hundred most frequent trigrams is computed for a selected set of languages.
At 1704 , a finite-state transducer of n-grams (e.g., tri-grams, etc.) is compiled for a plurality of text-characterizations with two additional tags at the end of each n-gram. The two additional tags map a text sequence identifying the n-gram's frequency of occurrence in one of the plurality of text-characterizations. In the example application of language identification, when a network of trigrams in a set of text-characterizations is compiled for language identification, the trigrams for each language are compiled with two extra tags added to the end of each trigram path; the first extra tag identifying the trigram frequency and the second extra tag identifying the transition label that identifies language associated with the trigram. That is, all of the paths in the resulting region-matching transducer compiled at 1704 lead to a label with an epsilon on the input (or lower) side and a domain or language identifier such as “</English>” on the opposite side. For example, the region-matching transducer 220 for the English trigram shown in FIG. 18 has a path that maps the sequence [279 English] to the trigram [p r e], and vice versa, encoding the fact that ‘pre’ is the 279th most frequent trigram (identified by reference number 1802 ) in the English language (identified by reference number 1804 ). When the most common trigrams for all the languages are unioned into a single transducer at 1704 , there are many paths for [p r e] each terminating with a different frequency and language tag.
When input data is received at 1706 , n-gram counts for the plurality of text-characterizations are reset (e.g., set to zero). In the example shown in FIG. 15 for language identification, the DATA field of the terminating XML symbol “</ENGLISH>” is reset.
At 1708 , the n-gram network compiled at 1706 is applied to input data, such as natural language data, received at 1706 . For each n-gram matched in the input data, a frequency counter associated with the text-characterization to which the n-gram corresponds is incremented at 1706 (A). After processing some or all of the input data at 1706 (A), the text-characterization of the data is identified as (i.e., labeled with) the n-gram of the text-characterization in the finite state transducer of n-grams compiled at 1704 with the greatest frequency counter at 1706 (B).
At 1708 (A), when an n-gram is associated with a unique characterization (e.g., applies to only one language or a very small subset of languages) and a match occurs, the counter for the n-gram is boosted by a predetermined amount. For example, when a trigram is matched at 1708 (A) while applying input data to the finite state transducer of n-grams compiled at 1704 , the counts of all the language labels on the opposite side of the final epsilon transitions are incremented. In the example shown in FIG. 15 , when a match occurs with a path in the transducer that terminates with a label that has an epsilon on the input side and an integer representing an XML symbol such as “</ENGLISH>” on the output side, the count in the DATA field of the corresponding label is incremented by one. If the last transition has no sister arcs, the count of the unique language to which it corresponds is boosted by a predefined amount (e.g., ten times the normal weight); otherwise the count is incremented by one. Such boosting of trigram counts may be used to distinguish between languages that are very similar to each other such as the case for Danish and Norwegian.
Once the finite state transducer of n-grams, compiled at 1704 , is applied at 1708 (A) to some or all input data received at 1706 , a text-characterization (or alternatively a subset of text-characterizations) is identified from the plurality of text-characterizations (recorded in n-gram DATA fields of the finite state transducer at 1708 (B)) as the text characterization with the greatest frequency counter (e.g., having the greatest frequency of occurrence in the input data). In the example for language identification, when determining the language for the input data “simple”, all of the following trigrams are identified, starting from the beginning of the input data, where the symbol # represents a blank: [# s i], [s i m], [i m p], [m p l], [p l e], [l e #]. In operation, each trigram that is found in the transducer compiled at 1704 casts a vote (i.e., increment the frequency counter) for the language to which it belongs. A running count of the maximum number of votes is recorded in the frequency counter associated with each trigram. When all of the trigrams have been processed, the language or languages that have received the greatest number of recorded votes is the selected as the language to which the input data belongs. In the case of the input data “simple”, the English language receives the most recorded votes.
At 1710 , the text-characterization or set of text-characterizations identified at 1708 (B) is output, which output may be used, for example, to tag and/or index the input data received at 1706 . For example, natural language input data may be tagged by one or more recognized text-characterizations such as language and topic (e.g., for natural language input data “The president met with his cabinet in Washington today.”, may be tagged using language and topic characterizations as “<ENGLISH><POLITICS> The president met with his cabinet in Washington today</POLITICS></ENGLISH>.”
Advantageously, the method set forth in FIG. 17 performs one or more text-characterizations, such as language identification and topic identification, in a single pass through input data, such as language data, thereby avoiding multiple comparisons with pre-computed language vectors. That is, the n-gram frequency vector of the input data and the n-gram frequency vectors of all the candidate text-characterizations need not be individually computed; instead the method of FIG. 17 simultaneously computes n-gram frequency values in one pass over the input data. A further advantage with the method of FIG. 17 is that a text-characterization may be identified as soon as the input data or some representative portion of it (e.g., the first ten words) has been processed.
E. Corpus Indexing With Complex-Query Patterns
FIG. 19 sets forth a method for facilitating the search for content in a document collection by automating indexing of complex query-patterns within a document collection. A complex query pattern (i.e., that defines “a complex query”), which may be a simple or compound expression, may be used for identifying particular (well defined) patterns of string occurrences within a document using operators that perform set operations (e.g., AND and OR) and operators for constraining a search based on proximity (e.g., NEAR) and word order (e.g., NEXT). Query patterns may be defined using only specified terms. Alternatively, query patterns may be defined using additional (e.g., synonyms) or replacement terms.
Known indexing systems index words and allow the construction of complex queries. With such known indexing systems, the computational time required to process a complex query is generally dependent on its complexity. In some search applications, a complex query may be repeated using different limiting criteria. For example, some search applications (e.g., e-discovery) may query large document collections using a repeating complex query to find a topic of interest that is repeated with other limiting search criteria. For such applications, the method set forth in FIG. 19 advantageously permits complex queries to be performed on a document collection using a simplified operation by transforming such complex queries at run time into an indexing creation operation that may be accessed using a corpus index.
FIG. 20 is an example of a complex query pattern which defines a complex query that may be used to search for synonyms of the string “car” (including the terms car, automobile, vehicle, etc.) next to (or alternately that occurs within a defined number of words or a document structure such a paragraph or sentence) synonyms of “loan” (including the terms loan, financing, mortgage, etc.). The complex query may be labeled with the query tag “@car_loan”. In the method set forth in FIG. 19 , the complex query pattern may be compiled into a finite state transducer for indexing each occurrence of the pattern in a corpus. Every identified string in the corpus satisfying the complex-query pattern is recorded in a corpus index for efficient retrieval of such occurrences in the corpus when referred to in subsequent searches using its query tag.
At 1902 of the method set forth in FIG. 19 , a complex-query pattern is received that is iteratively developed by refining the complex-query pattern until documents and passages in a development corpus are located with a predefined level of recall and precision. In one embodiment, the complex-query pattern that is received at 1902 is developed using the (complex) query engine 148 shown in FIG. 21 . The query engine 148 is used to develop a complex query pattern 2102 directed at finding occurrences of specified terms in a defined arrangement of terms (e.g., having a defined order, structure, or proximity) within a document in development corpus 2110 . The terms used to define the complex query patterns 2102 may be expanded, with additional or replacement terms using thesaurus 2108 , and classified, with classification labels using taxonomy 2106 .
After one or more complex-query patterns 2102 are defined, for example by a user or in an automated or semi-automated manner, the complex-query pattern 2102 is input to the query engine 148 to query a development corpus 2110 , thereby producing query results 2104 . The development corpus 2110 may be a set of documents that exemplify different classes of content, interest and genres that may form part of a larger corpus of documents. Depending on the quality of the query results 2104 , the complex query pattern 2102 used to identify the query results 2104 is refined using the query engine 148 . This process of refining the complex query 2102 may be repeated until query results 2102 are of sufficient quality to produce results with a predefined level of precision and recall. High quality query results may include the query results 2104 identifying documents from the development corpus 2110 that are related to specified content (e.g., documents related to an identified topic) and are adapted to identify documents of different genres (e.g., emails, memos, etc.).
At 1904 in FIG. 19 and as shown in FIG. 22 , the complex query pattern 2102 developed at 1902 is transformed into a region-matching transducer 220 using the regular expression compiler 142 , as shown in FIG. 22 , where the transition label of the arc that leads from the penultimate state of the region-matching transducer identifies the complex-query pattern. For example, a complex query “@car_loan” in the form of the regular expression shown in FIG. 23 may be compiled using regular expression compiler 142 into the region-matching transducer shown in FIG. 24 with the penultimate state transition label: “/car_loan”. The terms of auxiliary lexicons CAR and LOAN identified in the regular expression @car_loan with an Insert Flag Diacritic shown in FIG. 23 , may be expanded in a manual, semi-automated, or automated manner using the complex query engine 148 which accesses the taxonomy 2106 and the thesaurus 2108 .
At 1905 in FIG. 19 and as shown in FIG. 22 , the region matching transducer 220 is used by an index builder forming part of FST engine 144 to develop index 2204 or augmented index 2206 of corpus 2202 . When the index 2204 for the corpus 2202 does not already exist at 1906 , then the region-matching transducer is combined with a corpus-level transducer 2208 (e.g., using regular expression compiler 142 ) to define a combined transducer 2210 for identifying complex query patterns and/or entities from a part-of-speech class or an application-specific terminology class at 1908 . Examples of corpus-level transducers are the class-matching networks which are described when referring to reference numbers 402 and 404 in FIG. 4 .
At 1910 , the combined transducer 2210 is applied to the corpus 2202 to identify strings therein that satisfy patterns defined in the combined transducer 2210 , which produces a posting for each pattern identified in the corpus 2202 . Each posting specifies a pairing identifying the pattern and the location of the string satisfying the pattern in the corpus 2202 , which location may be specified on one or more levels (e.g., at the paragraph, sentence, or word level). At 1912 , the postings produced at 1910 are sorted and consolidated to define the corpus index 2204 that includes tags indexing locations in the corpus satisfying the patterns (e.g., query tags that satisfy complex-query patterns).
For example, FIG. 25 illustrates example corpus data with positional information added identifying the start of each sentence, where the first sentence starts at the 1 st character position and the second sentence starts at the 58 th character position of the corpus data. FIG. 26 illustrates a set of postings (produced at 1910 in FIG. 19 ) identified by the region matching transducer illustrated in FIG. 24 when applied to the example corpus data illustrated in FIG. 25 , where the postings shown in FIG. 26 are at the sentence level (e.g., the identified patterns “John”, “buy”, “automobile”, “dealer”, and “bank loan” all appear in the first sentence). The postings include patterns identified by the corpus level transducer 2208 (e.g., nouns such as “automobile” and “dealer”) as well as the patterns identified by the region-matching transducer 220 (e.g., the complex query pattern identified with the query tag “/car_loan”). FIG. 27 illustrates the set of posting shown in FIG. 26 after having been sorted and consolidated (e.g., the identified patterns “automobile”, “bank loan”, “buy”, “dealer”, and “John” appear together and in alphabetical order).
At 1920 in FIG. 19 and as shown in FIG. 28 , query engine 148 is enabled for receiving a query for searching corpus 2202 using a query tag that may be used to identify in the corpus index 2204 positions in the corpus 2202 satisfying its corresponding complex-query pattern. At 1922 , the query engine is further enabled for applying the query received at 1920 using the corpus index 2204 to identify locations in the corpus 2202 that satisfy the query. Depending on the parameters (e.g., operators) used to define the relationship between one or more query tags (identifying indexed complex-query patterns) and terms of the query received at 1920 , the application of the query at 1922 may include identifying, using the corpus index 2204 , positions where the one or more indexed complex-query patterns and terms appear in the corpus 2202 with some predefined arrangement or order. For example, FIG. 29 illustrates a query using the query tag “@car_loan” (which corresponds to the complex-query pattern defined by the region matching transducer 220 shown in FIG. 24 ), the operator “AND”, and the term “John”. FIG. 30 illustrates example search results after performing the search using the query shown in FIG. 29 on the corpus shown in FIG. 25 using the corpus index shown in FIG. 27 . As shown in FIG. 30 , the search involves intersecting sentence positions where both query terms appear in view of the AND operator, which occurs in the example corpus shown in FIG. 25 in the first sentence. More specifically, the complex-query pattern label “/car_loan” and the term “John” both appear together in the first sentence, where the example corpus has been indexed at the sentence level.
FIG. 20 is an exemplary method for expanding a complex query using synonyms. In this exemplary method, the operator “SYNS” is included in the query language to expand a specified term to include synonyms of that term. For example, a search limited to “car” may retrieve only that exact word and, possibly, the morphological variants of “car” such as “cars”. The expression “SYNS(car)” may retrieve additional terms such as “automobile” and “vehicle” and, possibly, their morphological variants. Operators such as “SYNS” may be used for defining searches that explore more general concepts rather than specific arrangements of entities.
In an alternative method for expanding a complex query, the expansion is made to occur in the corpus index 2204 , rather than expanding original query terms with additional terms. In this alternative method, the corpus index 2204 records which term occurrences are from original words and which are from synonyms. For example, the query expression SYNS(car) in this alternative method would return all occurrences of any synonym for the term using the corpus index 2204 .
Returning again to FIG. 19 , when the index 2204 for the corpus 2202 already exist at 1906 then the region matching transducer is applied to the corpus 2202 to identify strings therein that satisfy the complex-query pattern received at 1902 , where each identified string is recorded as a posting in an augmented index, where the augmented index specifies a query tag indexing locations in the corpus that satisfy the complex-query pattern. At 1916 , the augmented index is consolidated and sorted, and 1918 , the corpus index developed at 1908 , 1910 , and 1912 is merged with the augmented index.
Accordingly, the method shown in FIG. 19 , for facilitating the search for content in a document collection by automating the indexing of complex query-patterns within the document collection, may be used for enabling searches using complex-query patterns with named components (e.g., query tag “@car_loan”). Advantageously, the method translates the complex-query patterns into a region-matching transducer 220 that is used to recognize patterns defined therein that are subsequently encoded into a corpus index. In one embodiment, the method is adapted to track when query patterns are first compiled so that subsequent query patterns that are developed which are similar are not expanded and re-encoded into the corpus index.
F. Miscellaneous
Using the foregoing specification, the invention may be implemented as a machine (or system), process (or method), or article of manufacture by using standard programming and/or engineering techniques to produce programming software, firmware, hardware, or any combination thereof. It will be appreciated by those skilled in the art that the flow diagrams described in the specification are meant to provide an understanding of different possible embodiments of the invention. As such, alternative ordering of the steps, performing one or more steps in parallel, and/or performing additional or fewer steps may be done in alternative embodiments of the invention.
Any resulting program(s), having computer-readable program code, may be embodied within one or more computer-usable media such as memory devices or transmitting devices, thereby making a computer program product or article of manufacture according to the invention. As such, the terms “article of manufacture” and “computer program product” as used herein are intended to encompass a computer program existent (permanently, temporarily, or transitorily) on any computer-usable medium such as on any memory device or in any transmitting device.
A machine embodying the invention may involve one or more processing systems including, but not limited to, CPU, memory/storage devices, communication links, communication/transmitting devices, servers, I/O devices, or any subcomponents or individual parts of one or more processing systems, including software, firmware, hardware, or any combination or subcombination thereof, which embody the invention as set forth in the claims. Those skilled in the art will recognize that memory devices include, but are not limited to, fixed (hard) disk drives, floppy disks (or diskettes), optical disks, magnetic tape, semiconductor memories such as RAM, ROM, Proms, etc. Transmitting devices include, but are not limited to, the Internet, intranets, electronic bulletin board and message/note exchanges, telephone/modem based network communication, hard-wired/cabled communication network, cellular communication, radio wave communication, satellite communication, and other wired or wireless network systems/communication links.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
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Computer methods, apparatus and articles of manufacture therefor, are disclosed for text-characterization using a finite state transducer that along each path accepts on a first side an n-gram of text-characterization (e.g., a language or a topic) and outputs on a second side a sequence of symbols identifying one or more text-characterizations from a set of text-characterizations. The finite state transducer is applied to input data. For each n-gram accepted by the finite state transducer, a frequency counter associated with the n-gram of the one or more text-characterizations in the set of text-characterizations is incremented. The input data is classified as one or more text-characterizations from the set of text-characterizations using the frequency counters associated therewith.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a premixed air-fuel mixture supply device for supplying a premixed air-fuel mixture to a combustor for a gas turbine or an aircraft engine and, more particularly, to a premixed air-fuel mixture supply device for supplying a premixed air-fuel mixture to a combustor to make the combustor combust a premixed air-fuel mixture in a lean-burn mode, reduce NO x and prevent the deterioration of combustion while the combustor is in a low-load operation.
[0003] 2. Description of the Related Art
[0004] A conventional combustor for a gas turbine or an aircraft engine has a combustor casing, and a cylindrical or annular combustor liner disposed in the combustor casing to define a combustion chamber. A fuel nozzle is connected to a head part of the combustor liner. The combustor casing and the combustor liner define an air passage through which air supplied by an air compressor flows into the combustion chamber.
[0005] When fuel is injected in air for diffusive combustion in the combustion chamber of this combustor of a gas turbine or an aircraft engine, high-temperature regions are formed locally in the combustion gas, and the high-temperature regions increases the concentration of NO x in the combustion gas.
[0006] Interest in environmental problems has progressively increased in recent years and restrictions on environmental condition have been intensified. The inlet temperature of recent gas turbines and aircraft engines, namely, the outlet temperature of the combustors of gas turbines and aircraft engines, has been raised to improve the thermal efficiency of the gas turbines and aircraft engines. However, the local high-temperature regions in the combustion gas produced by diffusive combustion increase and the concentration of NO x increases accordingly as the outlet temperature of the combustors of gas turbines and such increases. Therefore, measures for reducing NO x is very important.
[0007] A gas turbine combustor with a lean premixed, prevaporized combustion system (a prevaporized, premixed air-fuel mixture lean-burn type combustor for a gas turbine) is proposed to reduce the concentration of NO x in the combustion gas. In this gas turbine combustor, fuel is supplied at a substantially fixed rate in a pilot combustion region on the upstream side of a combustion chamber to produce high-temperature combustion gas by stable combustion, a lean air-fuel mixture is burned in a main combustion region below the pilot combustion region for lea-burn combustion that scarcely produces NO x . When a liquid fuel is used, the liquid fuel is vaporized beforehand to produce a prevaporized, premixed air-fuel mixture for lean burn.
[0008] Referring to FIG. 3 showing a conventional combustor, compressed air supplied by an air compressor, not shown, flows through a space between a combustor casing 1 and a combustor liner 2 . When the combustor is a forward flow combustor, air flows in the direction of the blank arrow (→), and the right end, namely, the downstream end, of the combustor casing 1 is closed. When the combustor is a backward flow combustor, air flows in the direction of the arrow (←), and the left end, namely, the downstream end, of the combustor casing is closed. Combustion air reached the combustor head flows into a pilot combustion air passage 3 and a main combustion air passage 4 . Although the main combustion air passage 4 shown in FIG. 3 is divided into two air passages 4 a and 4 b , the main combustion air passage 4 does not necessarily need to be divided.
[0009] Referring to FIG. 4 showing a premixing air-fuel mixture supply device, pilot fuel is injected out through fuel injection holes 5 a formed in a pilot fuel injection nozzle 5 and arranged at angular intervals. Swirl devices 6 a and 6 b for swirling combustion air are disposed above the fuel injection holes 5 a . Main fuel is injected out through main fuel injection holes 7 arranged at angular intervals. Swirl devices 8 a and 8 b for swirling combustion air are disposed above the main fuel injection holes 7 . An atomization lip 9 extends downstream from the swirl devices 8 a and 8 b to atomize the main fuel. A prevaporizing, premixing chamber 10 is formed below the atomization lip 9 . A premixed air-fuel mixture produced in the prevaporizing, premixing chamber 10 is supplied into a combustion chamber 15 below the premixedg air-fuel mixture supply device. The premixed air-fuel mixture burns in the combustion chamber 15 .
[0010] Related techniques are disclosed in JP-A 8-42851, JP-A 9-145057 and JP-A 2002-206744.
[0011] The following problems arise when this previously proposed prevaporized, premixed air-fuel mixture lean-burn type combustor uses both the pilot fuel and the premixed air-fuel mixture while the combustor is in a low-load operation. The fuel injected by the premixed air-fuel mixture supply device is unable to vaporize in the prevaporizing, premixing chamber because the temperature of air around the fuel is comparatively low, unvaporized fuel drops mixed in the swirling air are caused to adhere to a wall defining the prevaporizing, premixing chamber by centrifugal force and the fuel cannot be satisfactorily atomized and vaporized. Consequently, the quality of combustion of the premixed air-fuel mixture in the combustion chamber is deteriorated.
[0012] While the prevaporized, premixed air-fuel mixture lean-burn type combustor is in a high-load operation, the quality of combustion in the combustion chamber is not deteriorated because the temperature around the injected fuel is sufficiently high, and fuel droplets are vaporized substantially completely before reaching the wall defining the prevaporizing, premixing chamber.
SUMMARY OF THE INVENTION
[0013] The present invention has been made to solve those problems in the prior art and it is therefore an object of the present invention to provide a premixed air-fuel mixture supply device for a gas turbine or an aircraft engine, capable of improving combustion in the combustor of the gas turbine or the aircraft engine.
[0014] According to the present invention, a premixed air-fuel mixture supply device combined with a combustor liner included in a combustor comprises: a prevaporizing, premixing unit having inner and outer walls defining a prevaporizing, premixing chamber; and a wall surrounding an end part of the outer wall so as to define a secondary combustion air passage together with the end part of the outer wall around the prevaporizing, premixing chamber; wherein a tail part of the outer wall is shaped in an atomization lip.
[0015] The premixed air-fuel mixture supply device according to the present invention further comprises a swirl device disposed in the secondary combustion air passage.
[0016] In the premixed air-fuel mixture supply device according to the present invention, the atomization lip is formed such that a tail part thereof lies at or near the exit of the prevaporizing, premixing chamber.
[0017] In the premixed air-fuel mixture supply device according to the present invention, the extremity of the tail part of the atomization lip is formed in a sharp edge.
[0018] In the premixed air-fuel mixture supply device according to the present invention, the extremity of the tail part of the atomization lip is cut perpendicularly or substantially perpendicularly to the flowing direction of the combustion air.
[0019] In the premixed air-fuel mixture supply device according to the present invention the extremity of the tail part of the atomization lip is cut perpendicularly or substantially perpendicularly to the flowing direction of the combustion air, and the extremity of the tail part of the atomization lip has a thickness between 1 to 3 mm.
[0020] In the premixed air-fuel mixture supply device according to the present invention, the secondary combustion air passage is formed around the prevaporizing, premixing chamber, and the sectional area of the secondary combustion air passage is 5% or below of the total sectional area of the prevaporizing, premixing chamber and the secondary combustion air passage.
[0021] In the premixed air-fuel mixture supply device according to the present invention, the secondary air passage is formed around the prevaporizing, premixing chamber, and the sectional area of the secondary combustion air passage is 5 to 10% of the total sectional area of the prevaporizing, premixing chamber and the secondary combustion air passage.
[0022] In the premixed air-fuel mixture supply device according to the present invention, the secondary air passage is formed around the prevaporizing, premixing chamber, and the thickness of the atomization lip formed in the tail part of the inner wall defining the secondary combustion air passage decreases in the flowing direction of combustion air so that the inside diameter of the atomization lip increases gradually in the flowing direction of combustion air.
[0023] In the premixed air-fuel mixture supply device according to the present invention, the secondary combustion air passage is formed around the prevaporizing, premixing chamber, and the thickness of the atomization lip formed in the tail part of the inner wall defining the secondary combustion air passage decreases in the flowing direction of combustion air so that the outside diameter of the atomization lip decreases gradually in the flowing direction of the combustion air.
[0024] In the premixed air-fuel mixture supply device according to the present invention, the secondary air passage is formed around the prevaporizing, premixing chamber, the swirling device disposed in the secondary combustion air passage swirls combustion air flowing through the secondary combustion air passage in one direction, and swirling devices disposed in an inner passage swirl combustion air flowing through the inner passage in the same direction.
[0025] In the premixed air-fuel mixture supply device according to the present invention, the secondary air passage is formed around the prevaporizing, premixing chamber, the swirling device disposed in the secondary air passage swirls combustion air flowing through the secondary air passage to swirl in one direction, and swirling devices disposed in an inner passage swirl combustion air flowing through the inner passage in a direction opposite the direction in which the swirling device disposed in the secondary combustion air passage swirls combustion air flowing through the secondary air passage.
[0026] In the premixed air-fuel mixture supply device according to the present invention, the prevaporizing, premixing unit injects the fuel in a direction substantially the same as the flowing direction of combustion air.
[0027] In the premixed air-fuel mixture supply device according to the present invention, the secondary combustion air passage is formed around the prevaporizing, premixing chamber, and the velocity of combustion air at the exit of the secondary combustion air passage is equal to or not lower than the velocity of air flowing through the inner passage.
[0028] Generally, main fuel injected while the combustor is in a low-load operation takes longer time for evaporation than that injected while the combustor is in a high-load operation because the temperature of combustion air into which the main fuel is injected is comparatively low while the combustor is in the low-load operation. Consequently, fuel droplets mixed in the swirling combustion air reach the outer wall of the prevaporizing, premixing chamber, adhere to the outer wall in a liquid film, adversely affecting the atomization of the fuel at the exit of the prevaporizing, premixing chamber.
[0029] The premixed air-fuel mixture supply device of the present invention has the secondary air passage formed around the prevaporizing, premixing chamber, and the atomization lip formed in the tail part of the inner wall of the secondary air passage. Therefore, the fuel spread in a liquid film over the outer wall of the prevaporizing, premixing chamber can be atomized at the edge of the atomization lip by air flowing along the outer and the inner surface of the atomization lip, so that the deterioration of combustion in the combustor can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The above and other objects, features and advantages of the present invention will become more apparent from the following description made in connection with the accompanying drawings, in which:
[0031] FIG. 1 is a schematic, longitudinal sectional view of a premixed air-fuel mixture supply device in a first embodiment according to the present invention;
[0032] FIG. 2 is a schematic longitudinal sectional view of a premixed air-fuel mixture supply device in a second embodiment according to the present invention;
[0033] FIG. 3 a schematic longitudinal sectional view of a conventional combustor; and
[0034] FIG. 4 is schematic longitudinal sectional view of a premixed air-fuel mixture supply device included in the combustor shown in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] FIGS. 1 and 2 show premixed air-fuel mixture supply devices in first and second embodiments, respectively. The premixed air-fuel mixture supply devices in the first and the second embodiment are substantially the same in construction.
[0036] Referring to FIG. 1 , the premixed air-fuel mixture supply device in the first embodiment, a pilot fuel injection unit is similar to the conventional fuel injection unit, and a main fuel injection unit is similar to that shown in FIG. 4 . A secondary air passage 11 is formed around a prevaporizing, premixing chamber 10 . A swirling device 12 for producing swirling air currents is disposed in the secondary air passage 11 . The thickness of a tail part of an outer wall defining the prevaporizing, premixing chamber 10 is decreased toward a combustion chamber, not shown, to form a downstream atomization lip 14 having an inside diameter gradually increasing toward the combustion chamber.
[0037] In the premixed air-fuel supply device in the second embodiment shown in FIG. 2 , a tail part of an outer wall defining a prevaporizing, premixing chamber 10 is decreased toward a combustion chamber, not shown, to form a downstream atomization lip 14 having an outside diameter gradually decreasing toward the combustor.
[0038] Description will be made of only the premixed air-fuel mixture supply device in the first embodiment will be described because the premixed air-fuel mixture supply devices in the first and the second embodiment are substantially the same in construction.
[0039] Main fuel is injected through main fuel injecting holes 7 into air currents flowing through an air passage 4 b in directions substantially perpendicular to the flowing direction of the air currents. Such a mode of injecting the main fuel is not restrictive, and the main fuel does not necessarily need to be injected substantially perpendicularly to the flowing direction of the air currents. For example, the main fuel may be injected upstream or may be injected downstream. When main fuel is injected from an intermediate wall between swirling devices 8 a and 8 b shown in FIG. 1 , it is preferable to inject the main fuel in a direction parallel to the surface of an upstream atomization lip 9 . The main fuel injecting holes 7 are arranged at angular intervals.
[0040] Part of the injected main fuel impinges on the inner surface of the upstream atomization lip 9 , flows downstream in a liquid film along the inner surface of the upstream atomization lip 9 . The liquid film of the main fuel is atomized at the edge of the upstream atomization lip 9 by air currents flowing along the outer and the inner surface of the upstream atomization lip 9 , and the atomized main fuel flows into the prevaporizing, premixing chamber 10 .
[0041] If combustor to which the premixed air-fuel mixture supply device supplies the premixed air-fuel mixture is in a high-load operation, the main fuel is injected into high-temperature air currents. Consequently, the main fuel is evaporated and mixed with air currents in the prevaporizing, premixing chamber 10 to produce a lean premixed air-fuel mixture, and the lean premixed air-fuel mixture flows into a combustion chamber 15 for lean burn.
[0042] If the combustor to which the premixed air-fuel mixture supply device supplies the premixed air-fuel mixture is in a low-load operation, the main fuel is injected at a low velocity into low-temperature air currents. Consequently, the quantity of the main fuel that impinges on the upstream atomization lip 9 is small, and some part of the injected main fuel flows downstream without evaporating in the prevaporizing, premixing chamber 10 because the temperature of the air currents is low, for example 200° C. or below. The main fuel not vaporized is carried by the swirling air currents and is caused to adhere to the outer wall of the prevaporizing, premixing chamber 10 by centrifugal force, and flows downstream in a liquid film. The liquid film of the main fuel is atomized at the edge of the downstream atomization lip 14 by air currents flowing along the outer and the inner surface of the downstream atomization lip 14 . The main fuel is thus evaporated, atomized and mixed with air currents in the prevaporizing, premixing chamber 10 to produce a premixed air-fuel mixture, and the premixed air-fuel mixture flows into the combustion chamber 15 . While the combustor is in a low-load operation, the premixed air-fuel mixture burns in a diffusive combustion mode instead of in a lean-burn mode. However, the mode of combustion of the premixed air-fuel mixture produced and supplied by the premixed air-fuel mixture supply device of the present invention is far better than that of combustion of a premixed air-fuel mixture produced and supplied by a premixed air-fuel supply device not provided with any air passage corresponding to the secondary air passage 11 and any member corresponding to the downstream atomization lip 14 . Diffusive combustion during the low-load operation improves flame stability.
[0043] The difference between the premixed air-fuel mixture supply devices in the first and the second embodiment will be comparatively described with reference to FIGS. 1 and 2 . The fuel atomized by the edge of the downstream atomization lip 14 of the first embodiment shown in FIG. 1 tends to diverge more widely than the fuel atomized by the edge of the downstream atomization lip 14 of the second embodiment shown in FIG. 2 . If the swirling direction of swirling air currents produced by the swirling device 8 a and 8 b , and the swirling direction of swirling air currents produced by the swirling device 12 are the same, the dispersion of the fuel injected through the fuel injecting holes 7 is suppressed, the fuel cannot be satisfactorily mixed with air, different parts of the air-fuel mixture have different local fuel concentrations, flame stability is improved particularly in the low-load operation, the swirling force of the air-fuel mixture at the exit of the prevaporizing, premixing chamber 10 is high, and the expansion of a reverse flow region in the combustion chamber 15 further improves flame stability, whereas the NO x reducing performance of the premixed air-fuel mixture supply device deteriorates to some extent. If the swirling direction of swirling air currents produced by the swirling device 8 a and 8 b , and the swirling direction of swirling air currents produced by the swirling device 12 are opposite to each other, the fuel is dispersed satisfactorily, the premixed air-fuel mixture supply device assumes contrastive characteristics; that is, flame stability deteriorates and the NO x decreasing performance of the premixed air-fuel mixture supply device is improved.
[0044] The sectional area of the secondary air passage 11 will be explained. Whereas the effect of air currents on atomizing the fluid at the edge of the downstream atomization lip 14 increases with increase in the sectional area of the secondary air passage 11 , the flow rate of air that flows through the air passages 4 a and 4 b decreases. Such a phenomenon due to increase in the sectional area of the secondary air passage 11 decreases the air-to-fuel ratio of the premixed air-fuel mixture at the exit of the prevaporizing, premixing chamber 10 while the combustor is in a high-load operation, which has a negative effect on the reduction of NO x . Suppose that the air passages 4 a , 4 b and 11 have sectional areas 4 as , 4 bs and 11 s , respectively. then, it is desirable that the ratio: 11 s /( 4 as + 4 bs + 11 s ) is between 5% and 10%. If the reduction of NO x while the combustor is in a high-load operation is important, the ratio: 11 s /( 4 as + 4 bs + 11 s ) is between 2% and 5% to produce a lean premixed air-fuel mixture.
[0045] The atomization effect of the air currents flowing through the secondary air passage 11 is satisfactory when the velocity of the air currents is high. Since the maximum velocity of the air currents is dependent on the pressure difference between the exterior and the interior of the liner, it is desirable that the velocity of the air currents is equal to or not lower than the velocity of air currents injected from the prevaporizing, premixing chamber 10 .
[0046] Although the tail part of the atomization lip is formed in a small thickness and the edge of the tail part is rounded in most cases, it is also effective in satisfactorily atomizing the fuel to sharpen the edge of the tail part, or to cut the edge of the tail part perpendicularly to the outer and the inner surface of the tail part of the atomization lip. When the edge of the tail part is cut perpendicularly to the outer and the inner surface of the tail part, the sectional area of the air passage increases sharply at the edge of the atomization lip. Such a sudden increase in the sectional area of the air passage disturbs the air currents around the edge of the atomization lip or produces small eddies, promoting the atomization of the fuel. In the premixed air-fuel mixture supply devices shown in FIGS. 1 and 2 , the edge of the atomization lip is cut perpendicularly to the outer and the inner surface of the atomization lip. It is undesirable that the thickness t of the edge of the atomization lip is excessively big because the excessively thick edge of the atomization lip reduces the atomizing effect of air currents flowing along the outer surface of the atomization lip. Desirably, the thickness t is between 1 to 3 mm.
[0047] The accompanying drawings are conceptual views of the premixed air-fuel mixture supply devices not concretely showing the construction of the premixed air-fuel mixture supply devices. Although the swirling devices included in the premixed air-fuel mixture supply devices embodying the present invention are supposed to be axial swirling devices, the same may be radial swirling devices. Although the foregoing premixed air-fuel mixture supply devices are supposed to have cylindrical shapes, the same may be formed in annular shapes.
[0048] Although the invention has been described in its preferred embodiments with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.
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A premixed air-fuel mixture supply device combined with a combustor liner included in a combustor comprises a prevaporizing, premixing unit having inner and outer walls defining a prevaporizing, premixing chamber, and a wall surrounding an end part of the outer wall so as to define a secondary combustion air passage together with the end part of the outer wall around the prevaporizing, premixing chamber. A tail part of the outer wall is shaped in an atomization lip. The extremity of the tail part of the atomization lip is formed in a sharp edge or is cut perpendicularly or substantially perpendicularly to the flowing direction of the combustion air.
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